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Valentine, B. D., H. Osterndorf, F. M. Welter, D. Appich, J. A. Wierbowski, and D. T. Simpson. "IBM zBX hardware management and operational controls." IBM Journal of Research and Development 56, no. 1.2 (January 2012): 17:1–17:10. http://dx.doi.org/10.1147/jrd.2011.2179229.
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Huang, Zhipeng, Jinyan Wang, Yaling Zhang, Yongxiang Yao, Lifei Huang, Xueyan Yang, Ling Wang, and Qinghua Pan. "Dynamics of Race Structures of Pyricularia oryzae Populations Across 18 Seasons in Guangdong Province, China." Plant Disease 105, no. 1 (January 2021): 144–48. http://dx.doi.org/10.1094/pdis-07-20-1438-re.
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Rice blast, caused by Pyricularia oryzae, is one of the most damaging fungal diseases affecting rice. Understanding how the pathogen’s race structure varies over time supports the efforts of rice breeders to develop improved cultivars. Here, the race structure of P. oryzae in Guangdong province, China, where rice is cropped twice per year, was assessed over 18 seasons from 1999 through 2008. The analysis was based on the reactions of a panel of seven differential Chinese cultivars to inoculation with a set of 1,248 isolates of P. oryzae in the province. The “total race frequency” parameter ranged from 14.7 to 39.7%, and the “race diversity index” ranged from 0.63 to 0.93. Twelve (ZA63, ZA31, ZA29, ZA21, ZA13, ZA9, ZB30, ZB17, ZB8, ZB2, ZC14, and ZC8) and two (ZD8 and ZD3) races were recognized as specific to indica and japonica rice types, respectively. Of the 59 distinct races identified, only two indica type races (ZC13 and ZC15) were identified as population-common, and nine indica type races (ZB1, ZB5, ZB6, ZB7, ZB13, ZB15, ZC5, ZC13, and ZC15) and one japonica type race (ZG1) were deemed to be population-dominant; the “total top two race isolate frequency” parameter ranged from 29.8 to 74.5%. On the host side, dynamics of resistance structures of the differential set were divided into three patterns: Both Tetep and Kanto 51 expressed the highest and most stable resistance, both Sifeng 43 and Lijiangxintuanheigu conveyed much lower and unstable resistance, and Zhenlong 13, Dongnong 363, and Heijiang 18 performed intermediate and seasonally dynamic resistance. Three interesting points distinguishing race structures of P. oryzae populations in southern and northeastern China were also discussed. [Formula: see text] Copyright © 2021 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .
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Oliveira, Matheus Menezes, and Joyce Correna Carlo. "Avaliação do conforto térmico e renovação de ar em ambientes com chaminés solares." Ambiente Construído 21, no. 1 (January 2021): 293–314. http://dx.doi.org/10.1590/s1678-86212021000100506.
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Resumo O uso de estratégias relacionadas à ventilação natural para garantir conforto térmico e renovação de ar é necessário em grande parte do território brasileiro. Nesse contexto, as chaminés solares promovem benefícios como o aumento das trocas de ar e do conforto dos usuários. Este artigo tem como objetivo investigar a capacidade de um modelo de chaminé solar proporcionar conforto e renovação de ar em salas de aula e escritórios. Foram realizadas duas etapas de simulações termoenergéticas no EnergyPlus: a primeira avaliou parâmetros como altura, número de dispositivos instalados por ambiente e orientação solar para proporcionar mais horas em conforto e renovação de ar para quatro cidades brasileiras; a segunda ampliou o escopo dos dispositivos/ambientes simulados para oito cidades brasileiras, com uso dos melhores parâmetros identificados. A variação dos climas na segunda avaliação apresentou um impacto de até 80% nas horas em conforto. A influência do dispositivo proporcionou um aumento médio de 28% no conforto nas salas de aula e 21% nos escritórios. Foram observadas taxas de renovação de ar média entre 2,4 e 13,5 trocas/hora. Os melhores resultados foram observados nas cidades da ZB1, ZB2, ZB3, ZB4 e ZB5, o que torna essas zonas bioclimáticas potencialmente favoráveis para a utilização dessa chaminé solar.
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Caldas, Lucas Rosse, Loyde Vieira de Abreu-Harbich, and Karla Emmanuela Ribeiro Hora. "Avaliação ambiental de alternativas construtivas de um edifício contêiner." PARC Pesquisa em Arquitetura e Construção 11 (June 29, 2020): e020008. http://dx.doi.org/10.20396/parc.v11i0.8654887.
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Contêineres vêm sendo utilizados como edifícios nos últimos anos. Para isto, devem atender requisitos de desempenho térmico obtidos, a depender do clima, com o uso de materiais isolantes e fechamentos adicionais. Assim, o objetivo desse estudo é comparar o desempenho ambiental de um edifício contêiner de uso comercial com diferentes estratégias construtivas da envoltória. A metodologia baseou-se em: (a) definição de alternativas construtivas da envoltória do edifício contêiner; (b) simulações termoenergéticas com auxílio do software DesignBuilder para quatro cidades de diferentes zonas bioclimáticas (ZB) brasileiras: São Paulo (ZB3), Brasília (ZB4), Teresina (ZB7) e Rio de Janeiro (ZB8); (c) Avaliação do Ciclo de Vida (ACV), com escopo do berço ao túmulo, considerando as seguintes categorias de dano: (1) Mudanças Climáticas, (2) Saúde Humana, (3) Qualidade do Ecossistema e (4) Depleção de Recursos. A alternativa construtiva da envoltória composta por drywall e isolante térmico foi a mais vantajosa dentre as avaliadas. A absortância solar das fachadas influenciou significativamente nos resultados, principalmente para as ZB7 e ZB8. A cidade de Teresina foi a que apresentou maior consumo de energia operacional e, consequentemente, maiores impactos ambientais. Ao final, apresentam-se algumas diretrizes ambientais para esta tipologia de projeto.
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Hasan, Said, Rugaya H. Serosero, and Salim Abubakar. "Distribusi Vertikal dan Keanekaragaman Jenis Moluska pada Ekosistem Hutan Mangrove di Gugusan Pulau-Pulau Sidangoli Dehe Kabupaten Halmahera Barat Provinsi Maluku Utara." Agrikan: Jurnal Agribisnis Perikanan 13, no. 1 (May 11, 2020): 29. http://dx.doi.org/10.29239/j.agrikan.13.1.29-37.
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Pola sebaran spesies-spesies moluska di hutan mangrove menunjukkan adanya suatu zonasi. Moluska mangrove dapat dibagi ke dalam tiga kelompok, yaitu: moluska pengunjung, fakultatif dan asli. Tujuan penelitian ini adalah mengkaji distribusi vertikal moluska dan keanekaragaman jenis, dominansi jenis, kemerataan jenis dan kesaman komunitas moluska hutan mangrove di Gugusan Pulau Sidangoli Kabupaten Halmahera Barat. Pengambilan moluska menggunakan metode transek kuadrat. Transek ditarik secara horizontal sejajar garis pantai berdasarkan zonasi hutan mangrove yaitu zona bagian depan (ZBD), zona bagian tengah (ZBT) dan zona bagian belakang (ZBB). Hasil penelitian diperoleh distribusi vertikal moluska pada Zonasi Bagian Depan (ZBD) memiliki keanekaragaman jenis moluska lebih tinggi dan terendah di Zona Bagian Belakang (ZBB). Struktur komunitas moluska untuk semua stasiun penelitian memiliki keanekaragaman jenis tergolong sedang, tidak ada jenis yang dominasi dan penyebaran jenis moluska sangat merata.
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Łopiński, Jakub, Beata Schmidt, Yongping Bai, and Krzysztof Kowalczyk. "Effect of the B:Zn:H2O Molar Ratio on the Properties of Poly(Vinyl Acetate) and Zinc Borate-Based Intumescent Coating Materials Exposed to a Quasi-Real Cellulosic Fire." Polymers 12, no. 11 (October 30, 2020): 2542. http://dx.doi.org/10.3390/polym12112542.
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In order to investigate an influence of the B:Zn:H2O molar ratio on the fire protection efficiency of poly(vinyl acetate)-based thermoplastic intumescent coating materials (ICs), systems containing ammonium polyphosphate, melamine, pentaerythritol and different types of zinc borates (ZBs) were tested in a vertical position in quasi-real fire conditions. 3ZnO·2B2O3·6H2O (ZB6), 2ZnO·3B2O3·3.5H2O (ZB3.5) or 3ZnO·2B2O3 (ZB0) were added in amounts of 1–10 wt. parts/100 wt. parts of the other coating components mixture. Char formation processes and thermal insulation features were investigated using an open-flame furnace heated according to the cellulosic fire curve. Thermogravimetric features (DTG), chemical structures (FTIR) and mechanical strength of the ICs and the chars were analyzed as well. It was revealed that the type and dose of the ZBs significantly affect thermal insulation time (TIT) (up to 450 °C of a steel substrate) and sagging (SI) of the fire-heated coatings as well as the compressive strength of the created chars. The highest TIT value (+89%) was noted for the sample with 2.5 wt. parts of ZB3.5 while the lowest SI (−65%) was observed for the coatings containing 10 wt. parts of the hydrated borates (i.e., ZB3.5 or ZB6). The best mechanical strength was registered for the sample filled with the anhydrous modifier (3 wt. parts of ZB0). The presented results show that the ICs with the proper ZBs can be used for effective fire protection of vertically positioned steel elements.
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Imer, M. R., M. González, N. Veiga, C. Kremer, L. Suescun, and L. Arizaga. "Synthesis, structural characterization and scalable preparation of new amino-zinc borates." Dalton Transactions 46, no. 45 (2017): 15736–45. http://dx.doi.org/10.1039/c7dt03186f.
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Zinc borates are important materials. We report the preparation of three novel ones: [Zn(NH3)3B4O5(OH)4]·H2O (ZB1), Zn3(H2B3O7)2·2NH3·4H2O (ZB2), and [Zn(NH3)4][B4O5(OH)4]·4H2O (ZB3).
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Sousa, Luana Resende de, Henor Artur de Souza, and Adriano Pinto Gomes. "Influência de paredes verdes no desempenho térmico de habitações sociais." PARC Pesquisa em Arquitetura e Construção 11 (December 21, 2020): e020029. http://dx.doi.org/10.20396/parc.v11i0.8658167.
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A utilização da vegetação como elemento de fachada ainda compreende uma prática bastante incipiente, mas tem se popularizado devido à promessa de melhoria no desempenho térmico das edificações, além de representar uma alternativa de ampliação da biodiversidade no ambiente urbano. Neste trabalho investiga-se a influência das paredes verdes, no contexto climático brasileiro, sobre o desempenho térmico de edifícios habitacionais de interesse social. Como metodologia, utiliza-se a simulação do comportamento termoenergético de um edifício habitacional multifamiliar, por meio do programa EnergyPlus, incluindo-se o modelo HAMT que leva em conta o processo de transferência de umidade através da envoltória, para três zonas bioclimáticas previstas na norma NBR 15.220-2005, clima extremo para inverno (ZB1), clima extremo de verão (ZB8) e para um clima considerado como intermediário (ZB3). Os resultados obtidos demonstram uma diferença na temperatura interna dos ambientes, decorrente dos dois arranjos de fachada analisados: com e sem vegetação. O uso da parede verde proporcionou uma redução na temperatura interna de até 2,8 °C no verão e um aumento de até 1,4 °C no inverno. Observa-se que a vegetação na fachada ajudou a manter a temperatura interna mais baixa durante o dia e amena durante a noite. Logo, as paredes verdes podem representar uma solução sustentável e de baixo custo a ser implantada às edificações, visando melhorar seu desempenho térmico.
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Poloumienko, Arkadi. "Cloning and comparative analysis of the bovine, porcine, and equine sex chromosome genes ZFX and ZFY." Genome 47, no. 1 (January 1, 2004): 74–83. http://dx.doi.org/10.1139/g03-099.
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A growing body of evidence suggests the involvement of sex chromosome genes in mammalian development. We report the cloning and characterization of the complete coding regions of the bovine Y chromosome ZFY and X chromosome ZFX genes, and partial coding regions of porcine and equine ZFX and ZFY genes. Bovine ZFY and ZFX are highly similar to each other and to ZFX and ZFY from other species. While bovine and human ZFY proteins are both 801 amino acids long, bovine ZFX is 5 amino acids shorter than human ZFX. Like in humans, both bovine ZFY and ZFX contain 13 zinc finger motifs and belong to the Krueppel family of C2H2-type zinc finger proteins. The internal exon–intron organization of the bovine, porcine and equine ZFX and ZFY genes has been determined and compared. Within this region, the exon lengths and the positions of the splice sites are conserved, further suggesting a high evolutionary conservation of the ZFX and ZFY genes. Additionally, new alternatively spliced forms of human ZFX have been identified.Key words: sex chromosome genes, zinc finger proteins, ZFX, ZFY, alternative splicing.
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Song, Xiaoling, Minghui Zhu, Fahong Zhang, Fei Zhang, Yijian Zhang, Yunping Hu, Lin Jiang, et al. "ZFX Promotes Proliferation and Metastasis of Pancreatic Cancer Cells via the MAPK Pathway." Cellular Physiology and Biochemistry 48, no. 1 (2018): 274–84. http://dx.doi.org/10.1159/000491727.
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Background/Aims: The role of ZFX in tumourigenesis is unclear. We aimed to study ZFX expression, regulation, and function and the clinical implications of this protein in human pancreatic cancer (PCa). Methods: One hundred and twenty patients with histologically confirmed PCa who underwent surgery were recruited for this study. Tumour samples and PCa cell lines were used to examine ZFX. Various cell functions related to tumourigenesis were assessed. In vivo mouse tumour xenografts were used to confirm the in vitro results. Results: Patients with ZFX-positive tumours had worse overall survival than patients with ZFX-negative tumours. The depletion of ZFX using lentiviral shRNAs significantly inhibited cell proliferation by inducing cell cycle arrest in G0/G1 phase and resulted in increased cell apoptosis and invasive repression. In vivo studies confirmed that ZFX promoted tumour growth. Mechanistically, MAPK pathway activation was involved in the oncogenic functions of ZFX. Conclusions: ZFX acts as a putative oncogene in PCa and could be a novel therapeutic target for this disease.
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Nail, Alexandra N., Jeramiah J. Smith, Martha L. Peterson, and Brett T. Spear. "Evolutionary Analysis of the Zinc Finger and Homeoboxes Family of Proteins Identifies Multiple Conserved Domains and a Common Early Chordate Ancestor." Genome Biology and Evolution 12, no. 3 (March 1, 2020): 174–84. http://dx.doi.org/10.1093/gbe/evaa039.
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Abstract The Zinc Fingers and Homeoboxes (Zhx) proteins, Zhx1, Zhx2, and Zhx3, comprise a small family of proteins containing two amino-terminal C2–H2 zinc fingers and four or five carboxy-terminal homeodomains. These multiple homeodomains make Zhx proteins unusual because the majority of homeodomain-containing proteins contain a single homeodomain. Studies in cultured cells and mice suggest that Zhx proteins can function as positive or negative transcriptional regulators. Zhx2 regulates numerous hepatic genes, and all three Zhx proteins have been implicated in different cancers. Because Zhx proteins contain multiple predicted homeodomains, are associated with interesting physiological traits, and seem to be only present in the vertebrate lineage, we investigated the evolutionary history of this small family by comparing Zhx homologs from a wide range of chordates. This analysis indicates that the zinc finger motifs and homeodomains are highly similar among all Zhx proteins and also identifies additional Zhx-specific conserved regions, including a 13 amino acid amino-terminal motif that is nearly identical among all gnathostome Zhx proteins. We found single Zhx proteins in the sea lamprey (Petromyzon marinus) and in the nonvertebrate chordates sea squirt (Ciona intestinalis) and lancelet (Branchiostoma floridae); these Zhx proteins are most similar to gnathostome Zhx3. Based on our analyses, we propose that a duplication of the primordial Zhx gene gave rise to Zhx3 and the precursor to Zhx1 and Zhx2. A subsequent tandem duplication of this precursor generated Zhx1 and Zhx2 found in gnathostomes.
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Zhang, Xiuyan, Yu Wang, Lun Xiao, Haixia Zhou, Li Zhu, and Yun Zhao. "Zinc Finger Protein X-Linked Exhibits Pro-Leukemia Activity Via WNT3 in Chronic Myeloid Leukemia Stem/Progenitor Cells." Blood 132, Supplement 1 (November 29, 2018): 4247. http://dx.doi.org/10.1182/blood-2018-99-114663.
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Abstract Zinc Finger protein, X-linked (ZFX) is a transcriptional regulator, which controls the self-renewal of both embryonic and hematopoietic stem cells and participates in pathogenesis of various cancers. Zfx deficiency impairs Notch intracellular domain (NotchIC) induced acute T-cell leukemia (T-ALL) or MLL-AF9 induced acute myeloid leukemia (AML) in mice models. However, the function of ZFX in chronic myeloid leukemia (CML) stem/progenitor cells has not been elucidated yet. In the present study, qRT-PCR analysis showed that ZFX expression was significantly higher in CD34+ cells from CML patients in chronic phase (CP) (n=8, 3.1-fold, P=0.0052) and patients in blast crisis (BC) (n=8, 18.6-fold, P=0.0050) compared with that in healthy donors (n=4). Two independent shRNA sequences against ZFX were delivered in CD34+ cells with lentiviral vector. The silence of ZFX had a stronger inhibitory effect on colony-forming cell (CFC) ability of CML CD34+ cells (75±5%) than that of healthy donor CD34+ cells (44±5%). Furthermore, ZFX silencing augmented Imatinib Mesylate (IM) sensitivity of CML CD34+ cells, especially in IM-resistant samples; due to the fact that ZFX silencing increased apoptosis induced by IM. To obtain the molecular insights of how ZFX acts, we generated transcriptome data comparing ZFX silenced CML CD34+ cells with control cells. qRT-PCR data validated that ZFX silencing caused a significantly declined expression of WNT3 in K562, MEG-01 and CML CD34+ cells (n=5). In addition, ZFX silencing decreased WNT3 protein expression as well. Interestingly, WNT3 had significantly higher expression in CD34+ cells from patients in CP (n=10, 5-fold, P=0.0006) compared with that in healthy donors (n=8). Silence of WNT3 inhibited the growth of K562 cells and enhanced IM sensitivity of these cells as well. Overexpression of WNT3 restored the growth inhibition and IM hypersensitivity upon ZFX silencing. Chromatin immunoprecipitation (ChIP) analysis revealed that ZFX was able to bind with WNT3 promoter, and luciferase assay showed that ZFX silencing significantly decreased the activity of WNT3 promoter. Finally, we also found that the expressions of c-Myc and cyclin D1 were reduced by ZFX silencing or WNT3 silencing, suggesting decreased WNT/Catenin signaling. Taken together, we have demonstrated that ZFX is aberrantly expressed in CML stem/progenitor cells, and it modulates the growth and IM response of CML stem/progenitor cells via wnt/Catenin pathway indicating ZFX is a new regulator of CML stem/progenitor cells, which deepens the understanding of CML pathology and potentially provides clues for novel therapies against this disease. Disclosures No relevant conflicts of interest to declare.
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Woo, Andrew J., Hui Huang, Taylor Piers, and Alan B. Cantor. "Essential Role of the Transcription Factor ZBP-89 in Lymphopoiesis." Blood 120, no. 21 (November 16, 2012): 277. http://dx.doi.org/10.1182/blood.v120.21.277.277.
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Abstract Abstract 277 We previously identified the Krüppel-type zinc finger transcription factor ZBP-89 (also called zfp148) as a novel GATA1 associated protein in erythroid and megakaryocytic cells. ZBP-89 also associates with other GATA family members such as GATA2 and GATA3, Friend of GATA (FOG) cofactors, and RUNX1. It is ubiquitously expressed, but has high-level expression in a subset of tissues including thymus, spleen, bone marrow, lung and brain. Our prior studies using morpholino knockdown in zebrafish, in vitro differentiation and chimeric mouse analysis of ZBP-89 genetrap embryonic stem cells, and lentiviral shRNA knock down in primary human CD34+ cells demonstrated a functional role for ZBP-89 in erythroid and megakaryocyte maturation. In this study, we generated conditional knock out mice to further examine the requirements for ZBP-89 in vivo. On a mixed strain background, full ZBP-89 knock out mice were born at close to Mendelian ratios. However, the ZBP-89−/− mice were severely runted and had increased mortality over the first 30 days of life. Surviving pups had significant growth failure, but eventually matched their wild type and heterozygous littermates by about 6 weeks of age. Analysis of erythroid maturation in bone marrow and spleen using flow cytometry for CD71 and Ter119 demonstrated impaired erythroid maturation in a ZBP-89 allele-dose dependent manner. On a pure C57BL/6 genetic background, nearly 100% of the ZBP-89−/− mice died within the first 10 days of life from unclear causes. ZBP-89fl/fl, Mx1-Cre mice developed lymphopenia and platelet abnormalities following activation of Cre by polyI-polyC injection. The lymphopenia was due to reduction in both B and T cells. Further delineation of the T-cell defect using ZBP-89fl/fl, Lck-Cre mice demonstrated impaired maturation of double negative (CD4−CD8−) T cells at the DN3 (CD25+ CD44−) to DN4 (CD25−CD44−) stages in thymi from 5–6 week old mice. These findings indicate that ZBP-89 plays functional roles in multiple hematopoietic lineages. Moreover, they identify ZBP-89 as a novel transcriptional regulator of lymphocyte development. We speculate that this latter role involves its known interactions with GATA3, FOG-1, and/or RUNX1, which are all similarly involved in lymphopoiesis. We also show that the ZBP-89 family member ZBP-99 is highly expressed in thymus and other hematopoietic tissues, and may therefore play partially overlapping roles with ZBP-89. Disclosures: No relevant conflicts of interest to declare.
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Mardon, G., S. W. Luoh, E. M. Simpson, G. Gill, L. G. Brown, and D. C. Page. "Mouse Zfx protein is similar to Zfy-2: each contains an acidic activating domain and 13 zinc fingers." Molecular and Cellular Biology 10, no. 2 (February 1990): 681–88. http://dx.doi.org/10.1128/mcb.10.2.681.
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The Zfy gene is located on the Y chromosome of placental mammals and encodes a zinc finger protein which may serve as the primary sex-determining signal. A related gene, Zfx, is similarly conserved on the X chromosome. Unlike that in most mammals, the mouse genome contains four homologous zinc finger loci: Zfy-1, Zfy-2, Zfx, and Zfa (on an autosome). We report that, in contrast to the mouse Zfy genes, Zfx is widely transcribed in embryos, newborns, and adults, both male and female. Moreover, Zfx transcripts contain long 3' untranslated sequences which are phylogenetically conserved. Zfa is a processed gene derived from Zfx. An analysis of cDNA clones demonstrated that Zfx encodes a 799-amino-acid protein that is 70% identical to the mouse Zfy-1 and Zfy-2 proteins. Zfx, Zfy-1, and Zfy-2 contain highly acidic amino-terminal domains and carboxy-terminal regions containing 13 zinc fingers. When fused to the DNA-binding domain of GAL4, the acidic domains of Zfx and Zfy-2 activated transcription in yeast cells.
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Mardon, G., S. W. Luoh, E. M. Simpson, G. Gill, L. G. Brown, and D. C. Page. "Mouse Zfx protein is similar to Zfy-2: each contains an acidic activating domain and 13 zinc fingers." Molecular and Cellular Biology 10, no. 2 (February 1990): 681–88. http://dx.doi.org/10.1128/mcb.10.2.681-688.1990.
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The Zfy gene is located on the Y chromosome of placental mammals and encodes a zinc finger protein which may serve as the primary sex-determining signal. A related gene, Zfx, is similarly conserved on the X chromosome. Unlike that in most mammals, the mouse genome contains four homologous zinc finger loci: Zfy-1, Zfy-2, Zfx, and Zfa (on an autosome). We report that, in contrast to the mouse Zfy genes, Zfx is widely transcribed in embryos, newborns, and adults, both male and female. Moreover, Zfx transcripts contain long 3' untranslated sequences which are phylogenetically conserved. Zfa is a processed gene derived from Zfx. An analysis of cDNA clones demonstrated that Zfx encodes a 799-amino-acid protein that is 70% identical to the mouse Zfy-1 and Zfy-2 proteins. Zfx, Zfy-1, and Zfy-2 contain highly acidic amino-terminal domains and carboxy-terminal regions containing 13 zinc fingers. When fused to the DNA-binding domain of GAL4, the acidic domains of Zfx and Zfy-2 activated transcription in yeast cells.
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Reizis, Boris, Sivan Harel, Jose M. Galan, and Teresita L. Arenzana. "Zfx Is an Essential and Specific Regulator of Hematopoietic Stem Cell Self-Renewal." Blood 108, no. 11 (November 16, 2006): 863. http://dx.doi.org/10.1182/blood.v108.11.863.863.
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Abstract Mammalian hematopoiesis is based on the activity of multipotent hematopoietic stem cells (HSC) that undergo continuous self-renewal throughout the adult life. The self-renewal represents a unique property of adult HSC, and appears distinct from the proliferation of hematopoietic progenitors or from the initial specification and expansion of embryonic HSC. Despite recent progress, little is known about the molecular mechanisms governing HSC self-renewal. Zfx is a broadly expressed zinc finger-containing transcriptional activator that is highly conserved in vertebrates. Using conditional gene targeting in mice, we demonstrate that Zfx is an essential and specific regulator of HSC self-renewal. The expression of Zfx was elevated in HSC compared to progenitors and differentiated cells. An inducible deletion of Zfx from the adult bone marrow (BM) resulted in the specific loss of the HSC population. The short-term proliferation and lodging of Zfx-deficient HSC in the BM were normal, suggesting a specific defect of long-term self-renewal. The deletion of Zfx in pre-established BM chimeras completely abrogated HSC maintenance as reflected by the rapid loss of HSC contribution to hematopoiesis. Furthermore, a constitutive pan-hematopoietic deletion of Zfx spared embryonic HSC in the fetal liver, yet resulted in the loss of adult BM HSC. In contrast, adult erythromyeloid progenitors or differentiated cells were not affected by the absence of Zfx. Genome-wide expression analysis identified candidate target genes of Zfx, some of which were controlled by Zfx in HSC but not in their differentiated progeny. Finally, several immediate-early and/or stress-inducible genes were upregulated specifically in Zfx-deficient HSC, suggesting that the latter undergo increased stress-related signaling. Thus, functional and gene expression analysis establishes Zfx as a novel specific regulator of adult HSC self-renewal. Further studies of the target genes and pathways controlled by Zfx should provide novel insights into the molecular basis of HSC function.
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Bai, Longchuan, and Juanita L. Merchant. "ZBP-89 Promotes Growth Arrest through Stabilization of p53." Molecular and Cellular Biology 21, no. 14 (July 15, 2001): 4670–83. http://dx.doi.org/10.1128/mcb.21.14.4670-4683.2001.
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ABSTRACT Transcription factor p53 can induce growth arrest and/or apoptosis in cells through activation or repression of downstream target genes. Recently, we reported that ZBP-89 cooperates with histone acetyltransferase coactivator p300 in the regulation of p21waf1, a cyclin-dependent kinase inhibitor whose associated gene is a target gene of p53. Therefore, we examined whether ZBP-89 might also inhibit cell growth by activating p53. In the present study, we demonstrate that elevated levels of ZBP-89 induce growth arrest and apoptosis in human gastrointestinal cell lines. The ZBP-89 protein accumulated within 4 h, and the p53 protein accumulated within 16 h, of serum starvation without changes in p14ARF levels, demonstrating a physiological increase in the cellular levels of these two proteins. Overexpression of ZBP-89 stabilized the p53 protein and enhanced its transcriptional activity through direct protein-protein interactions. The DNA binding and C-terminal domains of p53 and the zinc finger domain of ZBP-89 mediated the interaction. A point mutation in the p53 DNA binding domain, R273H, greatly reduced ZBP-89-mediated stabilization but not their physical interaction. Furthermore, ZBP-89 formed a complex with p53 and MDM2 and therefore did not prevent the MDM2-p53 interaction. However, heterokaryon assays demonstrated that ZBP-89 retained p53 in the nucleus. Collectively, these data indicate that ZBP-89 regulates cell proliferation in part through its ability to directly bind the p53 protein and retard its nuclear export. Our findings further our understanding of how ZBP-89 modulates cell proliferation and reveals a novel mechanism by which the p53 protein is stabilized.
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Malo, Madhu S., Moushumi Mozumder, Xiao Bo Zhang, Shaluk Biswas, Alexander Chen, Long-Chuan Bai, Juanita L. Merchant, and Richard A. Hodin. "Intestinal alkaline phosphatase gene expression is activated by ZBP-89." American Journal of Physiology-Gastrointestinal and Liver Physiology 290, no. 4 (April 2006): G737—G746. http://dx.doi.org/10.1152/ajpgi.00394.2005.
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Intestinal alkaline phosphatase (IAP) is an enterocyte differentiation marker that functions to limit fat absorption. Zinc finger binding protein-89 (ZBP-89) is a Kruppel-type transcription factor that appears to promote a differentiated phenotype in the intestinal epithelium. The purpose of this study was to investigate the regulation of IAP gene expression by ZBP-89. RT-PCR, quantitative real-time RT-PCR, Western blot analyses, and reporter assays were used to determine the regulation of IAP by ZBP-89 in HT-29 and Caco-2 colon cancer cells. ZBP-89 knockdown was achieved by specific short interfering (si)RNA. EMSA and chromatin immunoprecipitation (ChIP) were performed to examine the binding of ZBP-89 to the IAP promoter. The results of RT-PCR, quantitative real-time PCR, and Western blot analyses showed that ZBP-89 was expressed at low levels in Caco-2 and HT-29 cells, whereas IAP was minimally expressed and absent in these cells, respectively. Transfection with ZBP-89 expression plamid increased IAP mRNA and protein levels in both cell lines, whereas knockdown of endogenous ZBP-89 by siRNA reduced basal levels of IAP gene expression in Caco-2 cells. IAP-luciferase reporter assays, EMSA, and ChIP established that ZBP-89 activated the IAP gene through a response element (ZBP-89 response element: 5′-CCTCCTCCC-3′) located between −1018 and −1010 bp upstream of the AUG start codon. We conclude that ZBP-89 is a direct transcriptional activator of the enterocyte differentiation marker IAP. These findings are consistent with the role that this transcription factor is thought to play as a tumor suppressor and suggests its possible function in the physiology of fat absorption.
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Attar, R. M., and M. Z. Gilman. "Expression cloning of a novel zinc finger protein that binds to the c-fos serum response element." Molecular and Cellular Biology 12, no. 5 (May 1992): 2432–43. http://dx.doi.org/10.1128/mcb.12.5.2432.
Full textAbstract:
Induction of c-fos transcription by serum growth factors requires the serum response element (SRE). The SRE is a multifunctional element which responds to several positively and negatively acting signals. To identify cellular proteins that might mediate functions of the SRE, we screened a human cDNA expression library with an SRE probe. We report the isolation and characterization of SRE-ZBP, a previously unidentified SRE-binding protein. SRE-ZBP is a member of the C2H2 zinc finger family of proteins exemplified by TFIIIA and the Drosophila Krüppel protein. The seven tandemly repeated zinc finger motifs in SRE-ZBP are sufficient for high-affinity binding to the SRE. We show that SRE-ZBP is a nuclear protein and identify a candidate cellular protein encoded by the SRE-ZBP gene. Because we cannot detect any DNA-binding activity attributable to the endogenous protein, we propose that SRE-ZBP activity may be subject to posttranslational regulation. Like c-fos mRNA, SRE-ZBP mRNA is serum inducible in HeLa cells, but with slower kinetics. The role of SRE-ZBP in the regulation of c-fos transcription remains unestablished, but this protein binds to a region of the SRE where mutations lead to derepression.
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Attar, R. M., and M. Z. Gilman. "Expression cloning of a novel zinc finger protein that binds to the c-fos serum response element." Molecular and Cellular Biology 12, no. 5 (May 1992): 2432–43. http://dx.doi.org/10.1128/mcb.12.5.2432-2443.1992.
Full textAbstract:
Induction of c-fos transcription by serum growth factors requires the serum response element (SRE). The SRE is a multifunctional element which responds to several positively and negatively acting signals. To identify cellular proteins that might mediate functions of the SRE, we screened a human cDNA expression library with an SRE probe. We report the isolation and characterization of SRE-ZBP, a previously unidentified SRE-binding protein. SRE-ZBP is a member of the C2H2 zinc finger family of proteins exemplified by TFIIIA and the Drosophila Krüppel protein. The seven tandemly repeated zinc finger motifs in SRE-ZBP are sufficient for high-affinity binding to the SRE. We show that SRE-ZBP is a nuclear protein and identify a candidate cellular protein encoded by the SRE-ZBP gene. Because we cannot detect any DNA-binding activity attributable to the endogenous protein, we propose that SRE-ZBP activity may be subject to posttranslational regulation. Like c-fos mRNA, SRE-ZBP mRNA is serum inducible in HeLa cells, but with slower kinetics. The role of SRE-ZBP in the regulation of c-fos transcription remains unestablished, but this protein binds to a region of the SRE where mutations lead to derepression.
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Wang, Xiong, Li Ma, Meng-ling Huang, Yong-gang Chen, and Jin-hu Wu. "Effect of Zaoxiu ointment on wound-healing in experimental second degree burns rats." Tropical Journal of Pharmaceutical Research 18, no. 9 (June 29, 2021): 1913–17. http://dx.doi.org/10.4314/tjpr.v18i9.19.
Full textAbstract:
Purpose: To evaluate the healing efficacy of a Traditional Chinese Medicine (TCM) preparation Zaoxiu Burn Ointment (ZBO) on experimental burns in rats.
Methods: The rats were randomly divided into four groups of eight rats each: control group, silver sulfadiazine (SSD)-treated group, moist exposed burn ointment (MEBO)-treated group and ZBO-treated group. ZBO, SSD and MEBO were applied topically twice daily for 7 days. SSD and MEBO were used as reference control. The observation of wound area contraction and histological analysis of wound tissues were performed. The effect of ZBO on MMPs, VEGF and Type-III collagen proteins of wound tissue in rats were determined by Western blot.
Results: After 10 days of topical treatment with ZBO, ZBO-treated group showed faster reduction in wound area in comparison with control groups (p < 0.01). MMP-2, MMP-9, VEGF and type-III collagen expression of the wound tissue increased significantly (p < 0.05) in comparison with the control burn wounds in rats. The ZBO had no cytotoxic effect on BHK-21 cell line. Histological results showed an overall early recovery and regeneration in ZBO-treated group when compared with control group.
Conclusion: ZBO possesses significant wound-healing activity in full-thickness burn wounds in rats, and can potentially be developed for the treatment of burns patient in future.
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Li, Xiangen, Carl Simon Shelley, and M. Amin Arnaout. "Differential Role of the Transcription Factor ZBP-89 in Hemangioblast Fate Determination: ZBP-89 Is a Direct Regulator of SCL." Blood 110, no. 11 (November 16, 2007): 1253. http://dx.doi.org/10.1182/blood.v110.11.1253.1253.
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Abstract Several molecular pathways have been identified that regulate distinct stages in the developmental progression from mesoderm to the formation of the hematopoietic and vascular lineages. Our previous work indicated that ectopic expression of the zinc finger transcription factor ZBP-89 promotes hematopoietic lineage development and represses endothelial cell lineage differentiation from hemangioblasts in murine embryonic stem cells. Here we evaluated the functional consequences of stable knockdown of ZBP-89 in embryonic stem cells (ESC) on hematopoietic and vascular development. Stable knock down of ZBP-89 in ESC significantly decreased the number of Blast Colony Forming Cells (BL-CFC) hemangioblasts, as well as primitive and definitive hematopoietic progenitor colonies BFU-E, GM-CFU, G-CFU, M-CFU and GEMM-CFU in vitro. In contrast, sprouting angiogenesis was markedly increased in EB cultures. Flow cytometric analysis of the lineages derived from ZBP-89 deficient EB cultures showed that the early (C-kit+Sca-1+) and definitive (CD45+) hematopoietic stem cells populations were reduced, but the endothelial cell population (CD31+ VE-Cadherin+) was increased. RT-PCR analysis of EB cultures revealed a direct correlation between the expression levels of ZBP-89 and hematopoietic markers (including SCL and Runx1) but an inverse correlation with the vascular marker CD31, with no change in Oct4 expression level. To investigate the mechanism underlying the role of ZBP-89 in hematopoiesis, the effect of ZBP-89 on expression of SCL, a master regulator of hematopoiesis, was examined. The murine SCL promoter transduced into the ZBP-89-expressing MEL cell line drove luciferase gene expression. ZBP-89 knockdown in MEL cells markedly reduced SCL expression. ChIP analysis showed that endogenous ZBP-89 protein bound directly to the murine SCL promoter in MEL cells. Thus ZBP-89 plays a central role in fate determination of hemangioblasts; its induction suppresses angiogenesis but enhances differentiation of hemangioblasts along the hematopoietic pathway, an effect mediated through the regulated expression of SCL.
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Woo, Andrew J., Jonghwan Kim, Jian Xu, Hui Huang, and Alan B. Cantor. "Role of ZBP-89 in human globin gene regulation and erythroid differentiation." Blood 118, no. 13 (September 29, 2011): 3684–93. http://dx.doi.org/10.1182/blood-2011-03-341446.
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Abstract The molecular mechanisms underlying erythroid-specific gene regulation remain incompletely understood. Closely spaced binding sites for GATA, NF-E2/maf, and CACCC interacting transcription factors play functionally important roles in globin and other erythroid-specific gene expression. We and others recently identified the CACCC-binding transcription factor ZBP-89 as a novel GATA-1 and NF-E2/mafK interacting partner. Here, we examined the role of ZBP-89 in human globin gene regulation and erythroid maturation using a primary CD34+ cell ex vivo differentiation system. We show that ZBP-89 protein levels rise dramatically during human erythroid differentiation and that ZBP-89 occupies key cis-regulatory elements within the globin and other erythroid gene loci. ZBP-89 binding correlates strongly with RNA Pol II occupancy, active histone marks, and high-level gene expression. ZBP-89 physically associates with the histone acetyltransferases p300 and Gcn5/Trrap, and occupies common sites with Gcn5 within the human globin loci. Lentiviral short hairpin RNAs knockdown of ZBP-89 results in reduced Gcn5 occupancy, decreased acetylated histone 3 levels, lower globin and erythroid-specific gene expression, and impaired erythroid maturation. Addition of the histone deacetylase inhibitor valproic acid partially reverses the reduced globin gene expression. These findings reveal an activating role for ZBP-89 in human globin gene regulation and erythroid differentiation.
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Wei, Limin, Jifeng Xi, Yongsheng Zhang, Bo Zeng, Feng Li, Kaisheng Wang, Siyuan Zhang, et al. "The Use of RNAi Technology to Interfere with Zfx Gene Increases the Male Rates of Red Deer (Cervus elaphus) Offspring." BioMed Research International 2020 (May 19, 2020): 1–7. http://dx.doi.org/10.1155/2020/9549765.
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Zinc finger protein X-linked (Zfx) was regarded to be a sex determination factor and plays a critical role in spermatogenesis. RNAi is an effective method of silencing Zfx mRNA expression. However, there has been little research on the use of RNAi technology to control the sex of the offspring of red deer (Cervus elaphus). The objective of this study was first to explore an efficient method to alter the red deer offspring sex-ratio by silencing the gene Zfx during spermatogenesis. Three recombinant expression vectors pLL3.7/A, pLL3.7/B, and pLL3.7/C were constructed to interrupt the Zfx gene. The results showed that the expression of Zfx mRNA was significantly silenced by pLL3.7/A (P<0.01), compared with the control group. The group injected with pLL3.7/A produced 94 red deer, including 68 males and 26 females. The male rates (72.34%) were significantly higher than the control groups (P<0.01). Our result suggests that Zfx siRNA is a useful approach to control offspring sex in red deer. This study further confirms that the Zfx gene plays a significant role in the process of X spermatogenesis.
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Leupold, Jörg Hendrik, Irfan Ahmed Asangani, Giridhar Mudduluru, and Heike Allgayer. "Promoter cloning and characterization of the human programmed cell death protein 4 (pdcd4) gene: evidence for ZBP-89 and Sp-binding motifs as essential Pdcd4 regulators." Bioscience Reports 32, no. 3 (January 30, 2012): 281–97. http://dx.doi.org/10.1042/bsr20110045.
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Pdcd4 (programmed cell death protein 4) is an important novel tumour suppressor inhibiting transformation, translation, invasion and intravasation, and its expression is down-regulated in several cancers. However, little is known about the transcriptional regulation and the promoter of this important tumour suppressor. So far the following is the first comprehensive study to describe the regulation of Pdcd4 transcription by ZBP-89 (zinc-finger-binding protein 89), besides characterizing the gene promoter. We identified the transcriptional start sites of the human pdcd4 promoter, a functional CCAAT-box, and the basal promoter region. Within this basal region, computer-based analysis revealed several potential binding sites for ZBPs, especially for Sp (specificity protein) family members and ZBP-89. We identified four Sp1/Sp3/Sp4-binding elements to be indispensable for basal promoter activity. However, overexpression of Sp1 and Sp3 was not sufficient to enhance Pdcd4 protein expression. Analysis in different solid cancer cell lines showed a significant correlation between pdcd4 and zbp-89 mRNA amounts. In contrast with Sp transcription factors, overexpression of ZBP-89 led to an enhanced expression of Pdcd4 mRNA and protein. Additionally, specific knockdown of ZBP-89 resulted in a decreased pdcd4 gene expression. Reporter gene analysis showed a significant up-regulation of basal promoter activity by co-transfection with ZBP-89, which could be abolished by mithramycin treatment. Predicted binding of ZBP-89 to the basal promoter was confirmed by EMSA (electrophoretic mobility-shift assay) data and supershift analysis for ZBP-89. Taken together, data for the first time implicate ZBP-89 as a regulator of Pdcd4 by binding to the basal promoter either alone or by interacting with Sp family members.
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Wang, Yang, Zhi Hong Qian, Lin Han Feng, and Yu Qi Guo. "ZigBee Hybrid Routing Optimization Algorithm Based on Energy Balance." Advanced Materials Research 765-767 (September 2013): 1667–70. http://dx.doi.org/10.4028/www.scientific.net/amr.765-767.1667.
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Aiming at energy consumption problem in the ZBR hybrid routing algorithm, an improved algorithm (W-ZBR) based on ZBR routing protocol is proposed to reduce the network energy consumption. The algorithm was improved mainly from the following parts: Cluster-tree routing algorithm and AODVjr routing algorithm. In Cluster-tree routing algorithm the redundant packet of RREQ is limited to reduce energy consumption by setting the parent node id. In AODVjr routing algorithm the network energy consumption is balanced by monitoring the remaining energy of nodes. The simulation result indicated that W-ZBR performs better than ZBR in remaining energy ratio, routing overhead ratio, available node ratio and packet delivery ratio. The algorithm can also prolong the life span of network.
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Xiong, Hui, Gang Xiong, and Cui Hua She. "Effect of Glass Additions on Ca[(Li1/3Nb2/3)0.92Zr0.08]O3−δ Microwave Ceramics." Advanced Materials Research 535-537 (June 2012): 805–8. http://dx.doi.org/10.4028/www.scientific.net/amr.535-537.805.
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The effects of ZnO-B2O3-Na2O(ZBN) glass on the sinterability and microwave dielectric properties of Ca[(Li1/3Nb2/3)0.92Zr0.08]O3−δ ceramics were investigated . ZBN glass doping can effectively reduce sintering temperatue by 100~150°C. The temperature coefficient of resonator frequency τf increased with an increase of ZBN glass content and sintering temperatue. When ZBN glass of 1.8wt% were added, the optimum microwave dielectric properties: εr =22.1,Qf =18360GHz and τf = − 9.8×10−6/°C were obtained at the sintering temperature of 1000°C.
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Xiong, Gang. "Microwave Dielectric Properties of Ca[(Li1/3Nb2/3)0.92Zr0.08]O3−δ Ceramics with Glass Addition." Applied Mechanics and Materials 556-562 (May 2014): 318–21. http://dx.doi.org/10.4028/www.scientific.net/amm.556-562.318.
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The effects of ZnO-B2O3-Na2O(ZBN) glass on the sinterability and microwave dielectric properties of Ca [(Li1/3Nb2/3)0.92Zr0.08]O3−δ −0.05TiO2 ceramics were investigated . ZBN glass doping can effectively reduce sintering temperatue by 100~150oC. The temperature coefficient of resonator frequency τf increased with an increase of ZBN glass content and sintering temperatue. When ZBN glass of 1.8wt% were added, the optimum microwave dielectric properties: εr=32.8, Qf =13420GHz and τf= − 4.3×10−6/oC were obtained at the sintering temperature of 1000oC.
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Usman, Muhammad Ibrahim, Madu Adamu Gadaka, and Abubakar Bilyamini Maazu. "Evaluation of Some Toxic Heavy Metals in Rice and Beans Samples Cultivated in Yobe State, Nigeria." East African Journal of Health and Science 3, no. 1 (August 28, 2021): 145–51. http://dx.doi.org/10.37284/eajhs.3.1.396.
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Grains have become an integral part of the human diet due to their nutritional values, thus any form of contamination especially by heavy metals is of great concern. This research evaluated the level of Cadmium, Chromium, Lead and Mercury in the commonly consumed foods (Rice and Beans) across Yobe State, North-eastern Nigeria. A composite sample from each of the three Senatorial Zones was collected from farm harvests and designed as ZAR, ZAB, ZBR, ZBB, ZCR and ZCB for Zone A Rice, Zone A Beans, Zone B Rice, Zone B Beans, Zone C Rice and Zone C Beans respectively. The metal Concentration was determined using atomic absorption spectroscopy (AAS). Results in mg/Kg across the local governments indicates respective ranges for Hg, Pb, Cd, and Cr of 0.30 - 4.04, 0.16 - 0.92, 0.03 - 0.05 and 0.02- 0.52 in Rice, 0.14-3.73, 0.05-0.33, 0.05-0.07 and 0.00-0.14 in beans. Comparison of the results showed that with the exception of mercury, all metals are within the tolerable ranges set by International Standard Tolerable Limits and European Regulatory Standard. Potential hazards may be speculated because the detected levels are on the higher side of the tolerable ranges. A higher level of mercury in samples collected from Zone C might be associated with the reported cases of chronic kidney diseases from those areas.
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Xiong, Gang. "Influence of ZnO-B2O3-Na2O Glass on Microwave Dielectric Properties of Ca[(Li1/3Nb2/3)0.8Sn0.2]O3−δ−0.1TiO2 Ceramics." Materials Science Forum 663-665 (November 2010): 629–32. http://dx.doi.org/10.4028/www.scientific.net/msf.663-665.629.
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The effects of ZnO-B2O3-Na2O(ZBN) glass on the sinterability and microwave dielectric properties of Ca[(Li1/3Nb2/3)0.8Sn0.2]O3−δ−0.1TiO2 (CLNS−0.1TiO2) ceramics were investigated . ZBN glass doping can effectively reduce sintering temperatue by 100~150°C. The temperature coefficient of resonator frequency τf increased with an increase of ZBN glass content and sintering temperatue. When ZBN glass of 3wt% were added, the optimum microwave dielectric properties: εr =28.8,Qf =10960GHz and τf = − 7.5×10−6/°C were obtained at the sintering temperature of 1050°C.
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Tripoli, Paolo. "Tropical Chow Hypersurfaces." International Mathematics Research Notices 2019, no. 14 (October 30, 2017): 4302–24. http://dx.doi.org/10.1093/imrn/rnx260.
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Abstract Given a projective variety $X\subset\mathbb{P}^n$ of codimension $k+1$, the Chow hypersurface $Z_X$ is the hypersurface of the Grassmannian $\operatorname{Gr}(k, n)$ parametrizing projective linear spaces that intersect $X$. We introduce the tropical Chow hypersurface $\operatorname{Trop}(Z_X)$. This object only depends on the tropical variety $\operatorname{Trop}(X)$ and we provide an explicit way to obtain $\operatorname{Trop}(Z_X)$ from $\operatorname{Trop}(X)$. We also give a geometric description of $\operatorname{Trop}(Z_X)$. We conjecture that, as in the classical case, $\operatorname{Trop}(X)$ can be reconstructed from $\operatorname{Trop}(Z_X)$ and prove it for the case when $X$ is a curve in $\mathbb{P}^3$. This suggests that tropical Chow hypersurfaces could be the key to construct a tropical Chow variety.
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Queluz, Francine Náthalie Ferraresi Rodrigues, Camila Rafael Ferreira Campos, Ligia De Santis, Letícia Isaac, and Elizabeth Joan Barham. "Zarit Caregiver Burden Interview: Evidências de Validade para a População Brasileira de Cuidadores de Idosos." Revista Colombiana de Psicología 28, no. 1 (January 1, 2019): 99–114. http://dx.doi.org/10.15446/rcp.v28n1.69422.
Full textAbstract:
A Zarit Caregiver Burden Interview (ZBI) avalia a sobrecarga de cuidadores de idosos. Porém, ainda carece de evidências de validade para o contexto brasileiro, com cuidadores de idades variadas. Neste estudo, foram verificadas evidências de validade do ZBI –interna e baseadas nas relações com qualidade de vida e depressão–. No Estudo 1, participaram 285 cuidadores de idosos com idades entre 18 e 87 anos, que responderam à ZBI. No Estudo 2, 205 dos cuidadores do Estudo 1 também responderam ao Inventário de Depressão de Beck e à Escala de Qualidade de Vida. No Estudo 1, foram testados três modelos por meio de uma análise fatorial confirmatória e o alfa de Cronbach. No Estudo 2, foram medidascorrelações de escores na ZBI com escores de depressão e qualidade de vida. O modelo de três fatores se mostrou o maisadequado, apresentando bons índices de consistência interna. Foram observadas correlações negativas entre a ZBI e qualidade de vida e positivas com depressão. Portanto, este estudo contribuiu para o processo de validação da ZBI no Brasil, com cuidadores de faixa etária ampla.
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Li, Xiangen, Jing-wei Xiong, Carl Simon Shelley, HeiYoung Park, and M. Amin Arnaout. "The Transcription Factor ZBP-89 Controls Generation of the Hematopoietic Lineage in Zebrafish and Mouse Embryonic Stem Cells." Blood 108, no. 11 (November 16, 2006): 441. http://dx.doi.org/10.1182/blood.v108.11.441.441.
Full textAbstract:
Abstract Hematopoietic development is closely linked to that of blood vessels and the two processes are regulated in large part by transcription factors that control cell fate decisions and cellular differentiation. Both blood and blood vessels derive from a common progenitor, termed the hemangioblast, but the factors specifying development and differentiation of this stem cell population into the hematopoietic and vascular lineages remain ill defined. Here we report that knockdown of the Krüppel-like zinc finger ZBP-89 (ZNF148) in zebrafish embryos results in a bloodless phenotype, caused by disruption of both primitive and definitive hematopoiesis, leaving primary blood vessel formation intact. Expression of the primitive (Scl, Lmo2, Gata2, Gata1) and definitive (Runx1, c-Myb) hematopoietic stem cell lineage markers in ZBP-89 morphants were significantly decreased while expression of the lymphopoiesis lineage markers Ikaros and Gata3 was unaffected. These developmental HSC defects are rescued by injection of human ZBP-89 RNA, SCL RNA or ZBP-89 cDNA under control of the zebrafish Flk1 promoter. Injection of ZBP-89 RNA into cloche zebrafish embryos, which lack the hematopoietic and endothelial lineages, rescued hematopoiesis but not vasculogenesis. Overexpression of ZBP-89 in wild type zebrafish expanded hematopoietic progenitors (Scl+, Lmo2+, Gata1+) but reduced the endothelial cell markers FLK1 and TIE1. Forced expression of ZBP-89 in mouse embryonic stem cell cultures also induced the expansion of hematopoietic progenitors (c-KIT+, SCA1+) and definitive hematopoietic cell population (CD45+), but inhibited sprouting angiogenesis and the CD31+, VE-Cadherin+ endothelial cell population. These findings establish a unique regulatory role for ZBP-89, positioned at the interface between early blood and blood vessel development.
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Chattat, Rabih, Valeria Cortesi, Fabio Izzicupo, Maria Letizia Del Re, Cinzia Sgarbi, Andrea Fabbo, and Elisa Bergonzini. "The Italian version of the Zarit Burden Interview: a validation study." International Psychogeriatrics 23, no. 5 (December 16, 2010): 797–805. http://dx.doi.org/10.1017/s1041610210002218.
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ABSTRACTBackground: Caregiving experiences in dementia may have adverse effects on the caregiver's own physical and mental health. The Zarit Burden Interview (ZBI) is the most widely used instrument for assessing family carer burden and the purpose of the present study was to evaluate the psychometric properties of the Italian version of the ZBI (I-ZBI).Methods: I-ZBI was administered to a non-randomized sample of 273 caregivers related to consecutively attending outpatients with a previously established primary diagnosis of dementia, according to DSM-IV criteria. Measurements used for the construct validity of the instrument were the General Health Questionnaire (GHQ-12), Hospital Anxiety and Depression Scale (HADS) and the Symptom Checklist-90-Revised (SCL-90-R). Validity and reliability were evaluated, as well as the factor structure of the instrument.Results: Most caregivers were children (65%), female (72%) and living with the patient (53%), with quite a high level of burden. The I-ZBI demonstrates good reliability with high internal consistency (α = 0.90) and split-half correlation of 0.78, and good concurrent validity with other assessment tools. A five-factor solution was obtained for the I-ZBI and the original bi-factorial structure of the ZBI was not confirmed.Conclusions: The Italian version of the Zarit Burden Interview is valid, reliable and useful for use in clinical contexts and in future studies that could lead to a better understanding of carer burden in dementia. Clarifying the factorial structure of the ZBI would help to further the understanding of the large body of research using it and would also help to advance the understanding of subjective burden.
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Kühnel, Martina B., Christina Ramsenthaler, Claudia Bausewein, Martin Fegg, and Farina Hodiamont. "Validation of two short versions of the Zarit Burden Interview in the palliative care setting: a questionnaire to assess the burden of informal caregivers." Supportive Care in Cancer 28, no. 11 (February 15, 2020): 5185–93. http://dx.doi.org/10.1007/s00520-019-05288-w.
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Abstract Purpose Several validated outcome measures, among them the Zarit Burden Interview (ZBI), are valid for measuring caregiver burden in advanced cancer and dementia. However, they have not been validated for a wider palliative care (PC) setting with non-cancer disease. The purpose was to validate ZBI-1 (ultra-short version and proxy rating) and ZBI-7 short versions for PC. Methods In a prospective, cross-sectional study with informal caregivers of patients in inpatient (PC unit, hospital palliative support team) and outpatient (home care team) PC settings of a large university hospital, content validity and acceptability of the ZBI and its structural validity (via confirmatory factor analysis (CFA) and Rasch analysis) were tested. Reliability assessment used internal consistency and inter-rater reliability and construct validity used known-group comparisons and a priori hypotheses on correlations with Brief Symptom Inventory, Short Form-12, and Distress Thermometer. Results Eighty-four participants (63.1% women; mean age 59.8, SD 14.4) were included. Structural validity assessment confirmed the unidimensional structure of ZBI-7 both in CFA and Rasch analysis. The item on overall burden was the best item for the ultra-short version ZBI-1. Higher burden was recorded for women and those with poorer physical health. Internal consistency was good (Cronbach’s α = 0.83). Inter-rater reliability was moderate as proxy ratings estimated caregivers’ burden higher than self-ratings (average measures ICC = 0.51; CI = 0.23–.69; p = 0.001). Conclusion The ZBI-7 is a valid instrument for measuring caregiver burden in PC. The ultra-short ZBI-1 can be used as a quick and proxy assessment, with the caveat of overestimating burden.
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Yang, Liu-Pan, Song-Bo Lu, Arto Valkonen, Fangfang Pan, Kari Rissanen, and Wei Jiang. "A conformationally adaptive macrocycle: conformational complexity and host–guest chemistry of zorb[4]arene." Beilstein Journal of Organic Chemistry 14 (June 27, 2018): 1570–77. http://dx.doi.org/10.3762/bjoc.14.134.
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Large amplitude conformational change is one of the features of biomolecular recognition and is also the basis for allosteric effects and signal transduction in functional biological systems. However, synthetic receptors with controllable conformational changes are rare. In this article, we present a thorough study on the host–guest chemistry of a conformationally adaptive macrocycle, namely per-O-ethoxyzorb[4]arene (ZB4). Similar to per-O-ethoxyoxatub[4]arene, ZB4 is capable of accommodating a wide range of organic cations. However, ZB4 does not show large amplitude conformational responses to the electronic substituents on the guests. Instead of a linear free-energy relationship, ZB4 follows a parabolic free-energy relationship. This is explained by invoking the influence of secondary C–H···O hydrogen bonds on the primary cation···π interactions based on the information obtained from four representative crystal structures. In addition, heat capacity changes (ΔC p) and enthalpy–entropy compensation phenomena both indicate that solvent reorganization is also involved during the binding. This research further deepens our understanding on the binding behavior of ZB4 and lays the basis for the construction of stimuli-responsive materials with ZB4 as a major component.
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Misture, S. T., L. R. Chatfield, and R. L. Snyder. "Accurate fully automated powder diffraction data using zero-background sample holders." Powder Diffraction 9, no. 3 (September 1994): 172–79. http://dx.doi.org/10.1017/s0885715600019175.
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An increasingly frequent used sample holder, the zero-background holder (ZBH), is evaluated for use in external standard calibration of powder patterns. The effectiveness of the ZBH calibration method is determined by comparison to the conventional internal- and external-standard calibration techniques. The three calibration methods are compared using the results of lattice parameter refinements of test powders, using Si as the standard. Several test materials were used in the evaluation which cover a wide range of absorption coefficients so sample transparency effects can be distinguished from sample displacement effects. Results of the calibrations clearly indicate that the ZBH method gives precision and accuracy comparable to the internal-standard method, and significantly better than the external-standard technique. In addition, the ZBH method yields substantially better results than the internal-standard method for materials with low absorption coefficients. Low-angle calibrations are also made on a ZBH using a proposed standard, silver behenate, which has peaks from 1.5° to 20° 2θ. These calibrations have shown that if care is not taken to establish a monolayer of powder on the ZBH crystal, significant errors in refined lattice parameters will result.
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Ni, Weiya, Andrew A. Perez, Shannon Schreiner, Charles M. Nicolet, and Peggy J. Farnham. "Characterization of the ZFX family of transcription factors that bind downstream of the start site of CpG island promoters." Nucleic Acids Research 48, no. 11 (May 14, 2020): 5986–6000. http://dx.doi.org/10.1093/nar/gkaa384.
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Abstract Our study focuses on a family of ubiquitously expressed human C2H2 zinc finger proteins comprised of ZFX, ZFY and ZNF711. Although their protein structure suggests that ZFX, ZFY and ZNF711 are transcriptional regulators, the mechanisms by which they influence transcription have not yet been elucidated. We used CRISPR-mediated deletion to create bi-allelic knockouts of ZFX and/or ZNF711 in female HEK293T cells (which naturally lack ZFY). We found that loss of either ZFX or ZNF711 reduced cell growth and that the double knockout cells have major defects in proliferation. RNA-seq analysis revealed that thousands of genes showed altered expression in the double knockout clones, suggesting that these TFs are critical regulators of the transcriptome. To gain insight into how these TFs regulate transcription, we created mutant ZFX proteins and analyzed them for DNA binding and transactivation capability. We found that zinc fingers 11–13 are necessary and sufficient for DNA binding and, in combination with the N terminal region, constitute a functional transactivator. Our functional analyses of the ZFX family provides important new insights into transcriptional regulation in human cells by members of the large, but under-studied family of C2H2 zinc finger proteins.
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Kayadjanian, Nathalie, Caroline Vrana-Diaz, Jessica Bohonowych, Theresa V. Strong, Josée Morin, Diane Potvin, and Lauren Schwartz. "Characteristics and relationship between hyperphagia, anxiety, behavioral challenges and caregiver burden in Prader-Willi syndrome." PLOS ONE 16, no. 3 (March 25, 2021): e0248739. http://dx.doi.org/10.1371/journal.pone.0248739.
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Objectives Prader-Willi syndrome (PWS) is a rare genetic disorder characterized by maladaptive behaviors, amongst which hyperphagia is a life-long concern for individuals with PWS and their caregivers. The current study examined the contribution of hyperphagia and other factors to caregiver burden across lifespan, in 204 caregivers of individuals with PWS living in the US, using the Zarit Burden Interview (ZBI) and the hyperphagia questionnaire (HQ-CT). Results We found a strong relationship between ZBI and HQ-CT especially in individuals with PWS older than 4 y and showed that HQ-CT scores of individuals with PWS is positively correlated with ZBI scores of their caregivers. The weight status of individuals with PWS was not associated with HQ-CT and ZBI scores, except for obese individuals who had significantly higher HQ-CT scores when compared to normal weight PWS individuals. We looked at PWS symptoms and care-related issues that impacted individuals and caregivers the most. We found that care-related tasks had the biggest negative impact on caregivers of children aged 0–4 y, whereas anxiety, temper tantrums, and oppositional behaviors of older individuals with PWS had the biggest impact on their caregivers concomitant with their high caregiver burden. Finally, we assessed the variability of HQ-CT and ZBI over 6 months in a subgroup of 83 participants. Overall, neither measure differed between 6 months and baseline. Most individual’s absolute HQ-CT score changes were between 0–2 units, whereas absolute ZBI score changes were between 0–6 points. Changes in the caregiver’s or individual’s life had little or no effect on HQ-CT and ZBI scores. Conclusions This study demonstrates a relationship between hyperphagia and caregiver burden and sheds light on predominant symptoms in children and adolescents that likely underly PWS caregiver burden. The stability and relationship between HQ-CT and ZBI support ZBI as an additional outcome measure in PWS clinical trials.
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Taylor, Kathryn C., and Danielle R. Elli. "Isolation and Characterization of the Vascular-specific 22-kDa Zn-binding Protein." HortScience 32, no. 3 (June 1997): 475D—475. http://dx.doi.org/10.21273/hortsci.32.3.475d.
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A 22-kDa Zn-binding protein (ZBP) was isolated from the phloem tissue and evacuated xylem sap of `Valencia' sweet orange [Citrus sinensis (L.) Osbeck] on rough lemon [C. jambhiri (L.)], as well as Valencia on Rangpur lime [Citrus limonia Osbeck]. Phloem and xylem Zn was associated with the 22 kDa ZBP. The Mr value of this ZBP was estimated to be 19,500 by size exclusion chromatography and 22,800 by SDS-PAGE. This protein was isolated with an isoelectric point of 7.5. Ion exchange chromatography demonstrated that 22-kDa ZBP was highly anionic, requiring 0.43 M NaCl for elution from QAE Sepharose. The 22-kDa ZBP appears unique to citrus, having no cross reaction with protein from several tissues from a range of plant species. Accumulation decreased under Zn-deficient conditions, was enhanced by osmotic stress, and the protein completely disappeared with wounding. Amino acid composition demonstrated that the protein was rich in aspartate, and glutamate; and contained 6 cysteine, and 4 histidine residues. These amino acids may be involved in metal binding. N-terminal amino acid sequencing demonstrated that the 22-kDa ZBP had identity with sporamin A&B precursors, Kunitz-type trypsin inhibitors, and miraculin. It is suggested that the genes that encode these proteins are derived from a common ancestral gene.
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Köndgen, Johannes. "ZBB-Symposium." Zeitschrift für Bankrecht und Bankwirtschaft 20, no. 1 (January 1, 2008): 1. http://dx.doi.org/10.15375/zbb-2008-0101.
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Shi, Haifeng, Jiaxin Yang, Zhimin Yu, Yu Song, Edwin Yue Bun Pun, Xin Zhao, and Hai Lin. "Wide visible-range fluorescence of Eu3+ located in the macroscopic bi-layer ceramic/glass composite." RSC Advances 10, no. 33 (2020): 19474–81. http://dx.doi.org/10.1039/d0ra01236j.
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Holley-Guthrie, Elizabeth A., William T. Seaman, Prasanna Bhende, Juanita L. Merchant, and Shannon C. Kenney. "The Epstein-Barr Virus Protein BMRF1 Activates Gastrin Transcription." Journal of Virology 79, no. 2 (January 15, 2005): 745–55. http://dx.doi.org/10.1128/jvi.79.2.745-755.2005.
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ABSTRACT The Epstein-Barr virus (EBV) BMRF1 gene encodes an early lytic protein that functions not only as the viral DNA polymerase processivity factor but also as a transcriptional activator. BMRF1 has been previously shown to activate transcription of an EBV early promoter, BHLF1, though a GC-rich motif which binds to SP1 and ZBP-89, although the exact mechanism for this effect is not known (D. J. Law, S. A. Tarle, and J. L. Merchant, Mamm. Genome 9:165-167, 1998). Here we demonstrate that BMRF1 activates transcription of the cellular gastrin gene in telomerase-immortalized keratinocytes. Furthermore, BMRF1 activated a reporter gene construct driven by the gastrin promoter in a variety of cell types, and this effect was mediated by two SP1/ZBP-89 binding sites in the gastrin promoter. ZBP-89 has been previously shown to negatively regulate the gastrin promoter. However, ZBP-89 can function as either a negative or positive regulator of transcription, depending upon the promoter and perhaps other, as-yet-unidentified factors. BMRF1 increased the binding of ZBP-89 to the gastrin promoter, and a ZBP-89-GAL4 fusion protein was converted into a positive transcriptional regulator by cotransfection with BMRF1. BMRF1 also enhanced the transcriptional activity of an SP1-GAL4 fusion protein. These results suggest that BMRF1 activates target promoters through its effect on both the SP1 and ZBP-89 transcription factors. Furthermore, as the EBV genome is present in up to 10% of gastric cancers, and the different forms of gastrin are growth factors for gastrointestinal epithelium, our results suggest a mechanism by which lytic EBV infection could promote the growth of gastric cells.
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Woo, Andrew J., Jonghwan Kim, Jian Xu, Hui Huang, and Alan Cantor. "Role of the Krüppel-Type Zinc Finger Transcription Factor ZBP-89 In Human Globin Gene Regulation and Erythroid Development." Blood 116, no. 21 (November 19, 2010): 2067. http://dx.doi.org/10.1182/blood.v116.21.2067.2067.
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Abstract Abstract 2067 The molecular mechanisms underlying developmental globin gene regulation remain incompletely understood. Prior studies have identified key cis-regulatory elements within the beta globin locus that contain core regions of closely spaced functional binding sites for GATA, NF-E2p45/maf and GT/GC box binding transcription factors. We recently identified the GT/GC-box binding transcription factor ZBP-89 as a novel GATA-1 interacting partner, and showed that it is involved in erythroid development in mice (Woo et al. 2008. Mol. Cell Bio. 28:2675-2689). Brand et al. independently isolated ZBP-89 in NF-E2p45/mafk complexes from induced mouse erythroid leukemia (MEL) cells (Brand et al. 2004. Nat. Struct. Mol Biol. 11:73-80). In the current study, we show that ZBP-89 protein levels increase during in vitro erythroid differentiation of human bone marrow derived CD34+ cells. This correlates with the onset of alpha and beta globin gene transcription. ChIP-chip studies using ENCODE v2.0 arrays demonstrate that ZBP-89 occupies key cis-regulatory elements within both the beta globin (locus control regions HS3, HS2; delta and beta proximal promoters; and an intergenic region between gamma1 and delta globin) and alpha globin (HS-48, HS-40, HS-10 and alpha globin proximal promoters) loci in primary human erythroid precursors. Comparative analysis across the entire ENCODE array reveals a strong positive correlation between ZBP-89 occupancy, RNA polymerase II occupancy, and the activating histone marks acetylated histone 3 (AcH3) and trimethylated histone 3 lysine 4 (H3K4me3); and a negative correlation with the repressive mark trimethylated histone 3 lysine 27 (H3K27me3). Motif analysis under the ZBP-89 occupancy peaks indicates a preference for GGGG(G/A)NGGGG in vivo binding sites. Lentiviral shRNA mediated knock down of ZBP-89 in the in vitro differentiated CD34+ cells results in 30–50% reduction of alpha-, gamma-, and beta-globin gene expression, as well as modestly decreased expression of a number of additional erythroid-specific genes. Co-immunoprecipitation experiments demonstrate physical association between ZBP-89 and the GCN5/Trapp histone acetyltransferase complex. Based on these findings, we propose that ZBP-89 participates with GATA-1 and NF-E2 in the final epigenetic changes required for high-level expression of globin and other erythroid genes in terminally differentiating human erythroid cells. Disclosures: No relevant conflicts of interest to declare.
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Gonçalves-Pereira, Manuel, Isabel Carmo, Joaquim Alves da Silva, Ana L. Papoila, Raimundo Mateos, and Steven H. Zarit. "Caregiving experiences and knowledge about dementia in Portuguese clinical outpatient settings." International Psychogeriatrics 22, no. 2 (November 6, 2009): 270–80. http://dx.doi.org/10.1017/s1041610209991050.
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ABSTRACTBackground: Important public health and clinical issues remain unanswered concerning disease-related knowledge and caregiving experiences in dementia. The aim of this study is to describe these dimensions in Portuguese clinical settings and analyze the link between knowledge and burden, and also between knowledge and positive caregiving experiences.Methods: We studied a non-randomized sample of 116 caregivers of outpatients with ICD10-DCR diagnosis of dementia. Comprehensive assessments included Dementia Knowledge Questionnaire (DKQ), Zarit Burden Interview (ZBI), Caregiving Activity Survey (CAS), Positive Aspects of Caregiving (PAC) and General Health Questionnaire-12 (GHQ). Portuguese translations for DKQ, ZBI and PAC scales had been developed; validity aspects were documented, as well as test-retest reliability coefficients for ZBI (ICC = 0.93) and PAC (ICC = 0.85).Results: Most caregivers were close relatives, female and living with the patient. Although positive aspects of care were reported, burden and distress levels were moderate to high. Knowledge needs were not striking. Distress was moderately correlated to burden, but no associations were found between caregivers' knowledge and ZBI, PAC or GHQ. DKQ scores did not predict PAC nor ZBI scores. A relationship was found between ZBI, as dependent variable, and PAC, GHQ and CAS.Conclusions: A large proportion of caregivers in this sample, albeit informed about dementia, were at risk of high burden and distress. Knowledge about dementia may not be protective of burden per se, nor did it influence positive aspects of caregiving.
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Lin, Chung-Ying, Li-Jung Elizabeth Ku, and Amir H. Pakpour. "Measurement invariance across educational levels and gender in 12-item Zarit Burden Interview (ZBI) on caregivers of people with dementia." International Psychogeriatrics 29, no. 11 (August 1, 2017): 1841–48. http://dx.doi.org/10.1017/s1041610217001417.
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ABSTRACTBackground:The Zarit Burden Interview (ZBI) is a commonly used self-report to assess caregiver burden. A 12-item short form of the ZBI has been developed; however, its measurement invariance has not been examined across some different demographics. It is unclear whether different genders and educational levels of a population interpret the ZBI items similarly. Therefore, this study aimed to examine the measurement invariance of the 12-item ZBI across gender and educational levels in a Taiwanese sample.Methods:Caregivers who had a family member with dementia (n= 270) completed the ZBI through telephone interviews. Three confirmatory factor analysis (CFA) models were conducted: Model 1 was the configural model, Model 2 constrained all factor loadings, Model 3 constrained all factor loadings and item intercepts. Multiple group CFAs and the differential item functioning (DIF) contrast under Rasch analyses were used to detect measurement invariance across males (n= 100) and females (n= 170) and across educational levels of junior high schools and below (n= 86) and senior high schools and above (n= 183).Results:The fit index differences between models supported the measurement invariance across gender and across educational levels (∆ comparative fit index (CFI) = −0.010 and 0.003; ∆ root mean square error of approximation (RMSEA) = −0.006 to 0.004). No substantial DIF contrast was found across gender and educational levels (value = −0.36 to 0.29).Conclusions:The ZBI is appropriate for combined use and for comparisons in caregivers across gender and different educational levels in Taiwan.
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Baaloudj, Oussama, Achraf Amir Assadi, Mohamed Azizi, Hamza Kenfoud, Mohamed Trari, Abdeltif Amrane, Aymen Amine Assadi, and Noureddine Nasrallah. "Synthesis and Characterization of ZnBi2O4 Nanoparticles: Photocatalytic Performance for Antibiotic Removal under Different Light Sources." Applied Sciences 11, no. 9 (April 27, 2021): 3975. http://dx.doi.org/10.3390/app11093975.
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This work aims to synthesize a photocatalyst with high photocatalytic performances and explore the possibility of using it for antibiotic removal from wastewater. For that, the spinel ZnBi2O4 (ZBO) was produced with the co-precipitation method and its optical, dielectric, and electrochemical characteristics were studied. The phase has been determined and characterized by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR). For the ZBO morphology, a Scanning Electron Microscopy (SEM) has been used. Then, the optical and dielectric properties of ZBO have been evaluated by calculating refractive index n (λ), extinction coefficient (k), dissipation factor (tan δ), relaxation time (τ), and optical conductivity (σopt) using the spectral distribution of T(λ) and R(λ). An optical gap band of 2.8 eV was determined and confirmed. The electrochemical performance of ZBO was investigated and an n-type semiconductor with a flat band potential of 0.54 V_SCE was found. The photocatalytic efficiency of ZBO was investigated in order to degrade the antibiotic Cefixime (CFX) under different light source irradiations to exploit the optical properties. A high CFX degradation of approximately 89% was obtained under solar light (98 mW cm−2) only after 30 min, while 88% of CFX degradation efficiency has been reached after 2 h under UV irradiation (20 mW cm−2); this is in line with the finding of the optical characterizations. According to the obtained data, solar light assisted nanoparticle ZBO can be used successfully in wastewater to remove pharmaceutical products.
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Flores, Efracio Mamani, Rogério Almeida Gouvea, Maurício Jeomar Piotrowski, and Mário Lucio Moreira. "Band alignment and charge transfer predictions of ZnO/ZnX (X = S, Se or Te) interfaces applied to solar cells: a PBE+U theoretical study." Physical Chemistry Chemical Physics 20, no. 7 (2018): 4953–61. http://dx.doi.org/10.1039/c7cp08177d.
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We performed first-principles calculations within PBE and PBE+U approximations to study ZnO and ZnX bulk systems and ZnO/ZnX interfaces (X = S, Se or Te), to the better comprehension of charge transference through the interface.
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Arenzana, Teresita L., Matthew R. Smith-Raska, and Boris Reizis. "Transcription factor Zfx controls BCR-induced proliferation and survival of B lymphocytes." Blood 113, no. 23 (June 4, 2009): 5857–67. http://dx.doi.org/10.1182/blood-2008-11-188888.
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Abstract The development, homeostasis, and function of B lymphocytes involve multiple rounds of B-cell receptor (BCR)–controlled proliferation and prolonged maintenance. We analyzed the role of transcription factor Zfx, a recently identified regulator of hematopoietic stem cell maintenance, in B-cell development and homeostasis. Panhematopoietic or B cell–specific deletion of Zfx in the bone marrow blocked B-cell development at the pre-BCR selection checkpoint. Zfx deficiency in peripheral B cells caused accelerated B-cell turnover, depletion of mature recirculating B cells, and delayed T-dependent antibody responses. In addition, the numbers and function of B-1 cell lineage were reduced. Zfx-deficient B cells showed normal proximal BCR signaling, but impaired BCR-induced proliferation and survival in vitro. This was accompanied by aberrantly enhanced and prolonged integrated stress response and by delayed induction of cyclin D2 and Bcl-xL proteins. Thus, Zfx restrains the stress response and couples antigen receptor signaling to cell expansion and maintenance during B-cell development and peripheral homeostasis. These results identify a novel transcriptional regulator of the B-cell lineage and highlight the common genetic control of stem cell maintenance and lymphocyte homeostasis.
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Adachi, Kanna, Hayate Ishizuka, Minami Odagi, and Kazuo Nagasawa. "Synthetic Approaches to Zetekitoxin AB, a Potent Voltage-Gated Sodium Channel Inhibitor." Marine Drugs 18, no. 1 (December 26, 2019): 24. http://dx.doi.org/10.3390/md18010024.
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Voltage-gated sodium channels (NaVs) are membrane proteins that are involved in the generation and propagation of action potentials in neurons. Recently, the structure of a complex made of a tetrodotoxin-sensitive (TTX-s) NaV subtype with saxitoxin (STX), a shellfish toxin, was determined. STX potently inhibits TTX-s NaV, and is used as a biological tool to investigate the function of NaVs. More than 50 analogs of STX have been isolated from nature. Among them, zetekitoxin AB (ZTX) has a distinctive chemical structure, and is the most potent inhibitor of NaVs, including tetrodotoxin-resistant (TTX-r) NaV. Despite intensive synthetic studies, total synthesis of ZTX has not yet been achieved. Here, we review recent efforts directed toward the total synthesis of ZTX, including syntheses of 11-saxitoxinethanoic acid (SEA), which is considered a useful synthetic model for ZTX, since it contains a key carbon–carbon bond at the C11 position.