To see the other types of publications on this topic, follow the link: TOC complex.
Journal articles on the topic 'TOC complex'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 journal articles for your research on the topic 'TOC complex.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.
1
Ramundo, Silvia, Yukari Asakura, Patrice A. Salomé, Daniela Strenkert, Morgane Boone, Luke C. M. Mackinder, Kazuaki Takafuji, et al. "Coexpressed subunits of dual genetic origin define a conserved supercomplex mediating essential protein import into chloroplasts." Proceedings of the National Academy of Sciences 117, no. 51 (December 3, 2020): 32739–49. http://dx.doi.org/10.1073/pnas.2014294117.
Full textAbstract:
In photosynthetic eukaryotes, thousands of proteins are translated in the cytosol and imported into the chloroplast through the concerted action of two translocons—termed TOC and TIC—located in the outer and inner membranes of the chloroplast envelope, respectively. The degree to which the molecular composition of the TOC and TIC complexes is conserved over phylogenetic distances has remained controversial. Here, we combine transcriptomic, biochemical, and genetic tools in the green alga Chlamydomonas (Chlamydomonas reinhardtii) to demonstrate that, despite a lack of evident sequence conservation for some of its components, the algal TIC complex mirrors the molecular composition of a TIC complex fromArabidopsis thaliana.The Chlamydomonas TIC complex contains three nuclear-encoded subunits, Tic20, Tic56, and Tic100, and one chloroplast-encoded subunit, Tic214, and interacts with the TOC complex, as well as with several uncharacterized proteins to form a stable supercomplex (TIC-TOC), indicating that protein import across both envelope membranes is mechanistically coupled. Expression of the nuclear and chloroplast genes encoding both known and uncharacterized TIC-TOC components is highly coordinated, suggesting that a mechanism for regulating its biogenesis across compartmental boundaries must exist. Conditional repression of Tic214, the only chloroplast-encoded subunit in the TIC-TOC complex, impairs the import of chloroplast proteins with essential roles in chloroplast ribosome biogenesis and protein folding and induces a pleiotropic stress response, including several proteins involved in the chloroplast unfolded protein response. These findings underscore the functional importance of the TIC-TOC supercomplex in maintaining chloroplast proteostasis.
2
Sohrt, Karen, and Jürgen Soll. "Toc64, a New Component of the Protein Translocon of Chloroplasts." Journal of Cell Biology 148, no. 6 (March 20, 2000): 1213–22. http://dx.doi.org/10.1083/jcb.148.6.1213.
Full textAbstract:
A subunit of the preprotein translocon of the outer envelope of chloroplasts (Toc complex) of 64 kD is described, Toc64. Toc64 copurifies on sucrose density gradients with the isolated Toc complex. Furthermore, it can be cross-linked in intact chloroplasts to a high molecular weight complex containing both Toc and Tic subunits and a precursor protein. The 0 Å cross-linker CuCl2 yields the reversible formation of disulfide bridge(s) between Toc64 and the established Toc complex subunits in purified outer envelope membranes. Toc64 contains three tetratricopeptide repeat motifs that are exposed at the chloroplast cytosol interface. We propose that Toc64 functions early in preprotein translocation, maybe as a docking protein for cytosolic cofactors of the protein import into chloroplasts.
3
Chang, Wai-Ling, Jürgen Soll, and Bettina Bölter. "The gateway to chloroplast: re-defining the function of chloroplast receptor proteins." Biological Chemistry 393, no. 11 (November 1, 2012): 1263–77. http://dx.doi.org/10.1515/hsz-2012-0235.
Full textAbstract:
Abstract Chloroplast biogenesis often requires a tight orchestration between gene expression (both plastidial and nuclear) and translocation of ∼3000 nuclear-encoded proteins into the organelle. Protein translocation is achieved via two multimeric import machineries at the outer (TOC) and inner (TIC) envelope of chloroplast, respectively. Three components constitute the core element of the TOC complex: a β-barrel protein translocation channel Toc75 and two receptor constituents, Toc159 and Toc34. A diverse set of distinct TOC complexes have recently been characterized and these diversified TOC complexes have evolved to coordinate the translocation of differentially expressed proteins. This review aims to describe the recent discoveries relating to the typical characteristics of these distinct TOC complexes, particularly the receptor constituents, which are the main contributors for TOC complex diversification.
4
Kikuchi, Shingo, Jocelyn Bédard, Minako Hirano, Yoshino Hirabayashi, Maya Oishi, Midori Imai, Mai Takase, Toru Ide, and Masato Nakai. "Uncovering the Protein Translocon at the Chloroplast Inner Envelope Membrane." Science 339, no. 6119 (January 31, 2013): 571–74. http://dx.doi.org/10.1126/science.1229262.
Full textAbstract:
Chloroplasts require protein translocons at the outer and inner envelope membranes, termed TOC and TIC, respectively, to import thousands of cytoplasmically synthesized preproteins. However, the molecular identity of the TIC translocon remains controversial. Tic20 forms a 1-megadalton complex at the inner membrane and directly interacts with translocating preproteins. We purified the 1-megadalton complex from Arabidopsis, comprising Tic20 and three other essential components, one of which is encoded by the enigmatic open reading frame ycf1 in the chloroplast genome. All four components, together with well-known TOC components, were found stoichiometrically associated with different translocating preproteins. When reconstituted into planar lipid bilayers, the purified complex formed a preprotein-sensitive channel. Thus, this complex constitutes a general TIC translocon.
5
Becker, Thomas, Marko Jelic, Aleksandar Vojta, Alfons Radunz, Jürgen Soll, and Enrico Schleiff. "Preprotein recognition by the Toc complex." EMBO Journal 23, no. 3 (February 5, 2004): 520–30. http://dx.doi.org/10.1038/sj.emboj.7600089.
Full text
6
Hiltbrunner, A., J. Bauer, M. Alvarez-Huerta, and F. Kessler. "Protein translocon at the Arabidopsis outer chloroplast membrane." Biochemistry and Cell Biology 79, no. 5 (October 1, 2001): 629–35. http://dx.doi.org/10.1139/o01-145.
Full textAbstract:
Chloroplasts are organelles essential for the photoautotrophic growth of plants. Their biogenesis from undifferentiated proplastids is triggered by light and requires the import of hundreds of different precursor proteins from the cytoplasm. Cleavable N-terminal transit sequences target the precursors to the chloroplast where translocon complexes at the outer (Toc complex) and inner (Tic complex) envelope membranes enable their import. In pea, the Toc complex is trimeric consisting of two surface-exposed GTP-binding proteins (Toc159 and Toc34) involved in precursor recognition and Toc75 forming an aequeous protein-conducting channel. Completion of the Arabidopsis genome has revealed an unexpected complexity of predicted components of the Toc complex in this plant model organism: four genes encode homologs of Toc159, two encode homologs of Toc34, but only one encodes a likely functional homolog of Toc75. The availability of the genomic sequence data and powerful molecular genetic techniques in Arabidopsis set the stage to unravel the mechanisms of chloroplast protein import in unprecedented depth.Key words: Arabidopsis, genetics, chloroplast, protein import.
7
Ogawa, Shigesaburo, Mai Shinkawa, Ryuji Hirase, Taro Tsubomura, Katsuya Iuchi, and Setsuko Hara. "Development of Water-Insoluble Vehicle Comprising Natural Cyclodextrin—Vitamin E Complex." Antioxidants 10, no. 3 (March 20, 2021): 490. http://dx.doi.org/10.3390/antiox10030490.
Full textAbstract:
Development of a novel antioxidant-delivery vehicle exerting biosafety has been attracting a great deal of interest. In this study, a vehicle comprising a natural composite consisting of vitamin E (α-tocopherol; Toc) and cyclodextrin (CD) additives was developed, directed toward aqua-related biological applications. Not only β-CD, but also γ-CD, tended to form a water-insoluble aggregate with Toc in aqueous media. The aggregated vehicle, in particular the γ-CD-added system, showed a remarkable sustained effect because of slow dynamics. Furthermore, a prominent cytoprotective effect by the γ-CD–Toc vehicle under the oxidative stress condition was confirmed. Thus, the novel vitamin E vehicle motif using γ-CD as a stabilizer was proposed, widening the usability of Toc for biological applications.
8
Srinivasan, Karthik, Runrun Wu, Adrian Gonzalez, and Nicholas Noinaj. "Towards the architecture of the TOC protein complex." Acta Crystallographica Section A Foundations and Advances 75, a1 (July 20, 2019): a349. http://dx.doi.org/10.1107/s0108767319096600.
Full text
9
Andrès, Charles, Birgit Agne, and Felix Kessler. "The TOC complex: Preprotein gateway to the chloroplast." Biochimica et Biophysica Acta (BBA) - Molecular Cell Research 1803, no. 6 (June 2010): 715–23. http://dx.doi.org/10.1016/j.bbamcr.2010.03.004.
Full text
10
Jouhet, Juliette, and John C. Gray. "Is chloroplast import of photosynthesis proteins facilitated by an actin-TOC-TIC-VIPP1 complex?" Plant Signaling & Behavior 4, no. 10 (October 2009): 986–88. http://dx.doi.org/10.4161/psb.4.10.9665.
Full text
11
Karakas, Zeynep, Yasin Yilmaz, Dolay Damla Celik, Agageldi Annayev, Selcan Demirel, and Serap Erdem Kuruca. "Total Oxidant and Antioxidant Capacity in Patients with Transfusion Dependent and Nondependent Beta Thalassemia." Blood 126, no. 23 (December 3, 2015): 4573. http://dx.doi.org/10.1182/blood.v126.23.4573.4573.
Full textAbstract:
Abstract Background: The patients with β-thalassemia are usually under oxidative stress due to iron overload as a result of ineffective erythropoiesis and repeated transfusions. The endogen (uric acid, indirect bilirubin) and exogenous (ascorbic acid and vitamin E) antioxidants protect the cells from oxidative damage. The evaluation of antioxidant defense system can be easily done by measuring serum total antioxidant capacity. The aim of this study is to investigate the total oxidant (TOC) and antioxidant capacity (TAC) of patients with transfusion dependent (TDT) and nondependent (NTDT) β -thalassemia. Methods: Fifty eight patients (age range 3-59; median age 24 years) with β-thalassemia (16 nontransfusion dependent, 42 transfusion dependent) who were followed-up by Istanbul Medical Faculty Thalassemia Center were enrolled in this study. The sex and age matched 25 healthy subjects were used as control group. The total oxidant and antioxidant capacity were measured by Rel Assay Diagnostics, Total Oxidant Status (TOS) kit and Total Antioxidant Status (TAS) kit. The statistics of results were done by SPSS version 21. Results: 58 patients were included consisting of β thalassemia intermedia (n=16) and β thalassemia major (n=42). The total oxidant capacity was found higher in patients than control group without significant differences. Beside this, the antioxidant capacity of patients was significantly increased (2.75 mmol/l vs 1.94 mmol/l; p=0.001). Within patients group, there was no significant differences in terms of TAC while the TOC level was high in NTDT (2.99 mmol/l vs 1.88 mmol/l; p=0.08). There was no significant relationship between TOC and sex, age (<18 vs >18 years), ferritin and splenectomy status, as the same for TAC. Conclusions: The oxidative damage in patients with β-thalassemia can trigger the morbidity. The measurement of TOC and TAC status stands a useful, rapid, and simple method to evaluate the complex oxidative mechanism of disease. There are still controversial results about antioxidant status in thalassemia patients. The irregular consume of supportive treatment such as zinc, vitamin C, vitamin E and herbal medicine may affect the TOC and TAC status. The results of this study can guide us to use the antioxidants to decrease the oxidative stress. Figure 1. Figure 1. Disclosures No relevant conflicts of interest to declare.
12
Hiltbrunner, Andreas, Jörg Bauer, Pierre-Alexandre Vidi, Sibylle Infanger, Petra Weibel, Morten Hohwy, and Felix Kessler. "Targeting of an abundant cytosolic form of the protein import receptor at Toc159 to the outer chloroplast membrane." Journal of Cell Biology 154, no. 2 (July 23, 2001): 309–16. http://dx.doi.org/10.1083/jcb.200104022.
Full textAbstract:
Chloroplast biogenesis requires the large-scale import of cytosolically synthesized precursor proteins. A trimeric translocon (Toc complex) containing two homologous GTP-binding proteins (atToc33 and atToc159) and a channel protein (atToc75) facilitates protein translocation across the outer envelope membrane. The mechanisms governing function and assembly of the Toc complex are not yet understood. This study demonstrates that atToc159 and its pea orthologue exist in an abundant, previously unrecognized soluble form, and partition between cytosol-containing soluble fractions and the chloroplast outer membrane. We show that soluble atToc159 binds directly to the cytosolic domain of atToc33 in a homotypic interaction, contributing to the integration of atToc159 into the chloroplast outer membrane. The data suggest that the function of the Toc complex involves switching of atToc159 between a soluble and an integral membrane form.
13
Smith, Matthew D. "Protein import into chloroplasts: an ever-evolving storyThis review is one of a selection of papers published in the Special Issue on Plant Cell Biology." Canadian Journal of Botany 84, no. 4 (April 2006): 531–42. http://dx.doi.org/10.1139/b06-050.
Full textAbstract:
Chloroplasts are but one type of a diverse group of essential organelles that distinguish plant cells and house many critical biochemical pathways, including photosynthesis. The biogenesis of plastids is essential to plant growth and development and relies on the targeting and import of thousands of nuclear-encoded proteins from the cytoplasm. The import of the vast majority of these proteins is dependent on translocons located in the outer and inner envelope membranes of the chloroplast, termed the Toc and Tic complexes, respectively. The core components of the Toc and Tic complexes have been identified within the last 12 years; however, the precise functions of many components are still being elucidated, and new components are still being identified. In Arabidopsis thaliana (and other species), many of the components are encoded by more than one gene, and it appears that the isoforms differentially associate with structurally distinct import complexes. Furthermore, it appears that these complexes represent functionally distinct targeting pathways, and the regulation of import by these separate pathways may play a role in the differentiation and specific functions of distinct plastid types during plant growth and development. This review summarizes these recent discoveries and emphasizes the mechanisms of differential Toc complex assembly and substrate recognition.
14
Stanga, John P., Kanokporn Boonsirichai, John C. Sedbrook, Marisa S. Otegui, and Patrick H. Masson. "A Role for the TOC Complex in Arabidopsis Root Gravitropism." Plant Physiology 149, no. 4 (February 11, 2009): 1896–905. http://dx.doi.org/10.1104/pp.109.135301.
Full text
15
Yu, Z. T., X. J. Wang, E. L. Zhang, C. Y. Zhao, and X. Q. Liu. "Spatial distribution and sources of organic carbon in the surface sediment of Bosten Lake, China." Biogeosciences 12, no. 22 (November 19, 2015): 6605–15. http://dx.doi.org/10.5194/bg-12-6605-2015.
Full textAbstract:
Abstract. Lake sediment is an important carbon reservoir. However, little is known on the dynamics and sources of sediment organic carbon in Bosten Lake. We collected 13 surface (0–2 cm) sediment samples in Bosten Lake and analyzed total organic carbon (TOC), total nitrogen (TN), stable carbon isotopic composition in TOC (δ13Corg), and grain size. We found a large spatial variability in TOC content (1.8–4.4 %) and δ 13Corg value (−26.77 to −23.98 ‰). Using a three-end-member mixing model with measured TOC : TN ratio and δ13Corg, we estimated that 54–90 % of TOC was from autochthonous sources. Higher TOC content (> 3.7 %) was found in the east and central-north sections and near the mouth of the Kaidu River, which was attributable to allochthonous, autochthonous plus allochthonous, and autochthonous sources, respectively. The lowest TOC content was found in the mid-west section, which might be a result of high kinetic energy levels. Our study indicated that the spatial distribution of sediment TOC in the Bosten Lake was influenced by multiple and complex processes.
16
Yu, Z. T., X. J. Wang, E. L. Zhang, C. Y. Zhao, and H. Y. Lan. "Spatial distribution and sources of organic carbon in the surface sediment of the Bosten Lake, China." Biogeosciences Discussions 12, no. 16 (August 25, 2015): 13793–817. http://dx.doi.org/10.5194/bgd-12-13793-2015.
Full textAbstract:
Abstract. Lake sediment is an important carbon reservoir. However, little is known on the dynamics and sources of sediment organic carbon in the Bosten Lake. We collected 13 surface (0–2 cm) sediment samples in the Bosten Lake and analyzed total organic carbon (TOC), total nitrogen (TN), stable carbon isotopic composition in TOC (δ13Corg) and grain size. We found a large spatial variability in TOC content (1.8–4.4 %) and δ13Corg value (−26.77 to −23.98 ‰). Using a three end member mixing model with measured TOC : TN ratio and δ13Corg, we estimated that 54–90 % of TOC was from autochthonous sources. Higher TOC content (> 3.7 %) was found in the east and central-north sections and near the mouth of the Kaidu River, which was attributable to allochthonous, autochthonous plus allochthonous, and autochthonous sources, respectively. The lowest TOC content was found in the mid-west section, which might be a result of high kinetic energy levels. Our study indicated that the spatial distribution of sediment TOC in the Bosten Lake was influenced by multiple and complex processes.
17
Smith, Matthew D., Andreas Hiltbrunner, Felix Kessler, and Danny J. Schnell. "The targeting of the atToc159 preprotein receptor to the chloroplast outer membrane is mediated by its GTPase domain and is regulated by GTP." Journal of Cell Biology 159, no. 5 (December 9, 2002): 833–43. http://dx.doi.org/10.1083/jcb.200208017.
Full textAbstract:
The multimeric translocon at the outer envelope membrane of chloroplasts (Toc) initiates the recognition and import of nuclear-encoded preproteins into chloroplasts. Two Toc GTPases, Toc159 and Toc33/34, mediate preprotein recognition and regulate preprotein translocation. Although these two proteins account for the requirement of GTP hydrolysis for import, the functional significance of GTP binding and hydrolysis by either GTPase has not been defined. A recent study indicates that Toc159 is equally distributed between a soluble cytoplasmic form and a membrane-inserted form, raising the possibility that it might cycle between the cytoplasm and chloroplast as a soluble preprotein receptor. In the present study, we examined the mechanism of targeting and insertion of the Arabidopsis thaliana orthologue of Toc159, atToc159, to chloroplasts. Targeting of atToc159 to the outer envelope membrane is strictly dependent only on guanine nucleotides. Although GTP is not required for initial binding, the productive insertion and assembly of atToc159 into the Toc complex requires its intrinsic GTPase activity. Targeting is mediated by direct binding between the GTPase domain of atToc159 and the homologous GTPase domain of atToc33, the Arabidopsis Toc33/34 orthologue. Our findings demonstrate a role for the coordinate action of the Toc GTPases in assembly of the functional Toc complex at the chloroplast outer envelope membrane.
18
Maini, Rishma, Sandra Mounier-Jack, and Josephine Borghi. "How to and how not to develop a theory of change to evaluate a complex intervention: reflections on an experience in the Democratic Republic of Congo." BMJ Global Health 3, no. 1 (January 2018): e000617. http://dx.doi.org/10.1136/bmjgh-2017-000617.
Full textAbstract:
Theories of change (ToCs) describe how interventions can bring about long-term outcomes through a logical sequence of intermediate outcomes and have been used to design and measure the impact of public health programmes in several countries. In recognition of their capacity to provide a framework for monitoring and evaluation, they are being increasingly employed in the development sector. The construction of a ToC typically occurs through a consultative process, requiring stakeholders to reflect on how their programmes can bring about change. ToCs help make explicit any underlying assumptions, acknowledge the role of context and provide evidence to justify the chain of causal pathways. However, while much literature exists on how to develop a ToC with respect to interventions in theory, there is comparatively little reflection on applying it in practice to complex interventions in the health sector. This paper describes the initial process of developing a ToC to inform the design of an evaluation of a complex intervention aiming to improve government payments to health workers in the Democratic Republic of Congo. Lessons learnt include: the need for the ToC to understand how the intervention produces effects on the wider system and having broad stakeholder engagement at the outset to maximise chances of the intervention’s success and ensure ownership. Power relationships between stakeholders may also affect the ToC discourse but can be minimised by having an independent facilitator. We hope these insights are of use to other global public health practitioners using this approach to evaluate complex interventions.
19
Li, Cheng-Peng, Ya-Ping Li, Qing-Qing Huo, Wei Xiao, Chang-Qun Duan, Yong-Xia Wang, and Xiao-Long Cui. "Comparison of Prokaryotic Communities Associated with Different TOC Concentrations in Dianchi Lake." Water 12, no. 9 (September 13, 2020): 2557. http://dx.doi.org/10.3390/w12092557.
Full textAbstract:
The effect of total organic carbon (TOC) on the prokaryotic community structure in situ has been rarely known. This study aimed to determine the effect of TOC level on the composition and networks of archaeal and bacterial communities in the sediments of Dianchi Lake, one of the most eutrophic lakes in China. Microbial assemblages showed significantly associations with TOC. Moreover, relatively high and low TOC formed taxonomic differences in prokaryotic assemblages. According to the results, the most abundant bacteria across all samples were identified as members of the phyla Proteobacteria, Nitrospirae, Chloroflexi, Firmicutes and Ignavibacteriae. The dominant groups of archaea consisted of Euryarchaeota, Woesearchaeota DHVEG-6, Bathyarchaeota and WSA2. Lastly, the meta-analysis results highlighted that the low TOC (LT) prokaryotic community structure is larger and more complex compared to moderate TOC (MT). On the whole, the prokaryotic community structure is obviously distinct among groups with different TOC levels, and LT communities may interact with each other strongly in the Dianchi Lake sediment. This study can provide more insights into prokaryotic assemblages in eutrophic lake sediment and provide suggestions for the restoration and maintenance of sediment ecosystems.
20
Agne, Birgit, and Felix Kessler. "Protein transport in organelles: The Toc complex way of preprotein import." FEBS Journal 276, no. 5 (January 31, 2009): 1156–65. http://dx.doi.org/10.1111/j.1742-4658.2009.06873.x.
Full text
21
Gagat, Przemysław, and Paweł Mackiewicz. "Protein translocons in photosynthetic organelles of Paulinella chromatophora." Acta Societatis Botanicorum Poloniae 83, no. 4 (2014): 399–407. http://dx.doi.org/10.5586/asbp.2014.053.
Full textAbstract:
The rhizarian amoeba <em>Paulinella chromatophora</em> harbors two photosynthetic cyanobacterial endosymbionts (chromatophores), acquired independently of primary plastids of glaucophytes, red algae and green plants. These endosymbionts have lost many essential genes, and transferred substantial number of genes to the host nuclear genome via endosymbiotic gene transfer (EGT), including those involved in photosynthesis. This indicates that, similar to primary plastids, <em>Paulinella</em> endosymbionts must have evolved a transport system to import their EGT-derived proteins. This system involves vesicular trafficking to the outer chromatophore membrane and presumably a simplified Tic-like complex at the inner chromatophore membrane. Since both sequenced <em>Paulinella</em> strains have been shown to undergo differential plastid gene losses, they do not have to possess the same set of Toc and Tic homologs. We searched the genome of <em>Paulinella</em> FK01 strain for potential Toc and Tic homologs, and compared the results with the data obtained for <em>Paulinella</em> CCAC 0185 strain, and 72 cyanobacteria, eight Archaeplastida as well as some other bacteria. Our studies revealed that chromatophore genomes from both <em>Paulinella</em> strains encode the same set of translocons that could potentially create a simplified but fully-functional Tic-like complex at the inner chromatophore membranes. The common maintenance of the same set of translocon proteins in two <em>Paulinella</em> strains suggests a similar import mechanism and/or supports the proposed model of protein import. Moreover, we have discovered a new putative Tic component, Tic62, a redox sensor protein not identified in previous comparative studies of <em>Paulinella</em> translocons.
22
Schwenkert, Serena, Sophie Dittmer, and Jürgen Soll. "Structural components involved in plastid protein import." Essays in Biochemistry 62, no. 1 (February 27, 2018): 65–75. http://dx.doi.org/10.1042/ebc20170093.
Full textAbstract:
Import of preproteins into chloroplasts is an essential process, requiring two major multisubunit protein complexes that are embedded in the outer and inner chloroplast envelope membrane. Both the translocon of the outer chloroplast membrane (Toc), as well as the translocon of the inner chloroplast membrane (Tic) have been studied intensively with respect to their individual subunit compositions, functions and regulations. Recent advances in crystallography have increased our understanding of the operation of these proteins in terms of their interactions and regulation by conformational switching. Several subdomains of components of the Toc translocon have been studied at the structural level, among them the polypeptide transport-associated (POTRA) domain of the channel protein Toc75 and the GTPase domain of Toc34. In this review, we summarize and discuss the insight that has been gained from these structural analyses. In addition, we present the crystal structure of the Toc64 tetratrico-peptide repeat (TPR) domain in complex with the C-terminal domains of the heat-shock proteins (Hsp) Hsp90 and Hsp70.
23
Tan, Shung K., Anand Sanmugam, Mahmoud Danaee, Tindivanam M. Ramanujam, Mohan A. Nallusamy, Zakaria Zahari, and Thambidorai R. Rao. "Transition of Care in Paediatric Surgery: Current practices and perspectives of paediatric surgeons in Malaysia." Sultan Qaboos University Medical Journal [SQUMJ] 19, no. 4 (December 22, 2019): 352. http://dx.doi.org/10.18295/squmj.2019.19.04.011.
Full textAbstract:
Objectives: Transition of care (TOC) from paediatric to adult care is still at an early stage in Malaysia. This study aimed to explore current practices and perspectives regarding TOC among paediatric surgeons in Malaysia. Methods: This study was carried out between June and December 2017. All 48 paediatric surgeons currently working in Malaysia were invited to participate in a questionnaire-based survey to assess demographic characteristics and practices and perspectives regarding TOC. Results: A total of 38 paediatric surgeons participated in the survey (response rate: 79.2%). Overall, 97.4% did not have an organised TOC model in their institution, with most (65.8%) caring for paediatric patients with complex surgical conditions until adulthood. Although the majority (86.8%) felt that care should be transitioned to adult surgeons with appropriate credentials, most surgeons (84.2%) nevertheless preferred to be involved in the management of adolescent patients after transition. However, there was no consensus regarding the most suitable age to begin the transition. Years of experience as a paediatric surgeon and place of practice did not affect overall TOC practice scores (P >0.050 each). The presence of adult comorbidities was considered the most common reason to initiate TOC (81.6%), while the lack of TOC guidelines was perceived to be the greatest barrier (84.2%). Conclusion: This study provides a better understanding of TOC from the point of view of paediatric surgeons in Malaysia. However, further studies involving other stakeholders (i.e. patients and adult surgeons) are needed to help formulate a suitable and successful TOC model in this setting.Keywords: Transition to Adult Care; Pediatrics; Adolescents; Surgery; Attitudes; Professional Practice; Malaysia.
24
Tilman, Bodo. "Chloroplast signal length requirement reflects the outer membrane and TOC complex dimension." Periodicum Biologorum 117, no. 3 (November 2015): 337–46. http://dx.doi.org/10.18054/pb.2015.117.3.1002.
Full text
25
Wen, Zhang, Zhang Ya-Ming, Chen Jinbo, and Leng Kaijun. "Research on a scheduling mechanism in a complex system based on TOC." Chaos, Solitons & Fractals 89 (August 2016): 335–47. http://dx.doi.org/10.1016/j.chaos.2015.12.017.
Full text
26
Li, Bing, Yongchun Dong, Zhizhong Ding, Yiming Xu, and Chi Zou. "Renovation and Reuse of Reactive Dyeing Effluent by a Novel Heterogeneous Fenton System Based on Metal Modified PTFE Fibrous Catalyst/H2O2." International Journal of Photoenergy 2013 (2013): 1–10. http://dx.doi.org/10.1155/2013/169493.
Full textAbstract:
Cu-Fe bimetallic grafted polytetrafluoroethylene (PTFE) fiber complexes were prepared and optimized as the novel heterogeneous Fenton catalysts for the degradation of reactive dyes under UV irradiation. Cotton fabrics were dyed with three reactive dyes, namely, Reactive Red 195, Reactive Yellow 145, and Reactive Blue 222, in tap fresh water using exhaustion process. The spent dyeing effluents were then collected and degraded with the optimized Cu-Fe bimetallic grafted PTFE fiber complex/H2O2system. The treated dyeing effluents were characterized and reused for the dyeing of cotton fabrics through the same process. The effect of reuse process number on quality of the dyed cotton fabrics was examined. The results indicated that the Cu-Fe bimetallic modified PTFE fiber complex with a Cu/Fe molar ratio of 2.87 was found to be the most effective fibrous catalyst, which enhanced complete decolorization of the treated dyeing effluents with H2O2in 4 h. However, the TOC removal for the treated dyeing effluents was below 80%. The dyeing quality was not affected for three successive cycles. The increase in residual TOC value influences fourth dyeing cycle. Further TOC reduction of the treated effluents is needed for its repeated reuse in more than three dyeing cycles.
27
HALEVI, GIDEON. "PRODUCTION MANAGEMENT — SIMPLE OR COMPLEX." International Journal of Innovation and Technology Management 01, no. 04 (December 2004): 359–71. http://dx.doi.org/10.1142/s0219877004000313.
Full textAbstract:
Theoretical production planning and scheduling is actually very simple task: The plant gets orders which defines the product, the quantity and delivery dates. The resources of the plants are known, the product bill of material is known and the task of production scheduling is to make sure that the orders will be ready on time, that's all. It seems strange that in order to meet this simple task, over 100 complex production planning methods were proposed. Some of the outstanding ones are: PICS; MRP; ERP; GT; TOC; FMS; IMS; CIM; CE; JIT; Kanaban; TQM; Agent…, AGILE etc. Yet the search for "THE" method is carried on. In this paper an attempt to analyze why production planning is regarded as a complex task, and why the search for "THE" production planning method is still an open topic for researchers. Furthermore, to demonstrate how introduction of flexibility will restore the simplicity of production planning.
28
Kruk, J., K. Burda, A. Radunz, K. Strzałka, and G. H. Schmid. "Antagonistic Effects of α-Tocopherol and α-Tocoquinone in the Regulation of Cyclic Electron Transport around Photosystem II." Zeitschrift für Naturforschung C 52, no. 11-12 (December 1, 1997): 766–74. http://dx.doi.org/10.1515/znc-1997-11-1208.
Full textAbstract:
Abstract α-Tocoquinone (α-TQ ) and α-tocopherol (α-TOC) which cannot substitute for plastoquinone-9 (PQ-A) as an electron acceptor from photosystem II (PS II), influence the oxygen evolution activity of thylakoid membranes under continuous illumination. In the presence of the herbicide DCMU and the protonophore FCCP which stimulate cyclic electron transport around PS II, α-TQ decreased oxygen evolution whereas α-TOC enhanced it. The effects are attributed to a stimulation or an inhibition of cyclic electron transport around PS II by α-TQ and α-TOC, respectively. Results of flash light experiments on PS II preparations show that both α-TQ and α-TOC increased the d-parameter which describes the transition probability from the S3- to the S0-state of the oxygen-evolving complex, although to a smaller extent when PQ-A is added alone to the preparations. The initial S-state distribution in darkadapted samples was changed only upon PQ-A addition and influenced neither by α-TQ nor by α-TO C supplementation. These effects indicate different kinds of interaction of PQ-A, α-TQ and α-TOC with the PS II components. α-TQ increased and α-TOC decreased the “total miss” parameter both in the presence or absence of PQ-A. A possible site of interaction of α-TQ and α-TO C with the cyclic electron transport around PS II is suggested.
29
Dichter, Martin, Jonas Hylla, Almuth Berg, Daniela Eggers, Ralph Möhler, Gabriele Meyer, Sascha Köpke, and Margareta Halek. "How to Achieve the Desired Outcomes of a Complex Intervention in Nursing Homes: A Theory of Change." Innovation in Aging 4, Supplement_1 (December 1, 2020): 383. http://dx.doi.org/10.1093/geroni/igaa057.1234.
Full textAbstract:
Abstract Background Recent systematic reviews suggest the effectiveness of complex psychosocial interventions to reduce sleep disturbances in people with dementia (PwD) living in nursing homes. However, it is unclear how and under which circumstances these interventions work and which components and processes are crucial determinants for effectiveness. Objectives To develop a Theory of Change (ToC) that describes a causal chain for the reduction of sleep disturbances. Design and Methods The ToC approach is a participatory method in intervention development to generate knowledge about how, why, and under which circumstances interventions are effective. We conducted two expert workshops, a subsequent expert survey (n=12), a systematic literature review, and expert interviews (day and night nurses). Results Necessary preconditions for the reduction of sleep disturbances were identified on staff, management and cultural levels of nursing homes. Intermediate goals like “individual knowledge on PwD is available”, “a specific institutional concept to promote sleep is implemented”, “person-centred care is implemented” and “sleep preferences of PwD are fulfilled” were defined. The intermediate goals, interventions, promoting and inhibiting factors as well as rationales were sorted into a causal chain. All intermediate goals were rated as relevant or highly relevant based on the expert survey. Conclusions The ToC model displays how a complex psychosocial intervention is likely to be effective in reducing sleep disturbances and meeting sleep preferences of PwD in nursing homes. The model is the basis for the development and evaluation of a planned complex psychosocial intervention to prevent and reduce sleep disturbances in PwD.
30
Ahmed, Selim. "Integrating DMAIC approach of Lean Six Sigma and theory of constraints toward quality improvement in healthcare." Reviews on Environmental Health 34, no. 4 (December 18, 2019): 427–34. http://dx.doi.org/10.1515/reveh-2019-0003.
Full textAbstract:
Abstract Healthcare is a unique service industry and it deals with complex tasks. To overcome complex tasks, healthcare organizations need to implement DMAIC (Define, Measure, Analyze, Improve, Control) approach of Lean Six Sigma (LSS) to improve quality performance. Application of DMAIC in a healthcare organization provides guidelines on how to handle a quality service system toward patient satisfaction. This approach also helps healthcare service providers to reduce waste, variation and work imbalance in the service processes. This chapter discusses five phases of DMAIC approach and its integration with the theory of constraints (TOC) for continuous improvements in healthcare performance. The integration of TOC and DMAIC approach would enhance healthcare performance by reducing medical costs, medical errors, administration errors and defects. Moreover, this integration can improve performance in healthcare service processes where it is not possible to reduce bottlenecks.
31
Gupta, Nabanita, Supratik Sarkar, and Kurt J. Marfurt. "Seismic attribute driven integrated characterization of the Woodford Shale in west-central Oklahoma." Interpretation 1, no. 2 (November 1, 2013): SB85—SB96. http://dx.doi.org/10.1190/int-2013-0033.1.
Full textAbstract:
The organic-rich, silty Woodford Shale in west-central Oklahoma is a prolific resource play producing gas and liquid hydrocarbons. We calibrated seismic attributes and prestack inversion using well logs and core information within a seismic geomorphologic framework to define the overall basin architecture, major stratigraphic changes, and related variations in lithologies. Core measurements of elastic moduli and total organic content (TOC) indicated that the Woodford Shale can be broken into three elastic petrotypes important to well completion and hydrocarbon enrichment. Upscaling these measurements facilitates regional mapping of petrotypes from prestack seismic inversion of surface data. Seismic attributes highlight rugged topography of the basin floor of the Paleo Woodford Sea, which controls the lateral and vertical distribution of different lithofacies containing variable quantity of TOC as well as quartz, which controls brittleness. Depressions on the basin floor contain TOC-lean cherty lithofacies alternating with TOC-rich lithofacies, resulting in brittle-ductile rock couplets. In contrast, basin floor highs are characterized by overall TOC-rich ductile lithofacies. Seismic attributes illuminate complex post-Woodford tectonic deformation. The Woodford Shale is known to be naturally fractured on outcrop. Image log analysis in other shale plays showed a good correlation between such tectonic features and natural fractures. These features need to be correlated with well trajectories and production data to determine which hypothesized “fracture sets,” if any, improve well performance.
32
Hanley, Terry, Aaron Sefi, Janet Grauberg, Julie Prescott, and Andre Etchebarne. "A Theory of Change for Web-Based Therapy and Support Services for Children and Young People: Collaborative Qualitative Exploration." JMIR Pediatrics and Parenting 4, no. 1 (March 22, 2021): e23193. http://dx.doi.org/10.2196/23193.
Full textAbstract:
Background Web-based counseling and support has become increasingly commonplace for children and young people (CYP). Currently, there is limited research that focuses on the mechanisms of change within complex telepsychology platforms, a factor that makes designing and implementing outcome measures challenging. Objective This project aims to articulate a theory of change (ToC) for Kooth, a web-based therapy and support platform for CYP. Methods A collaborative qualitative research design involving professional staff, academic partners, and young people was used to develop the ToC. The following three major reflective phases were engaged: a scoping workshop involving professional staff and academic partners, a series of explorative projects were completed to inform the development of the ToC, and the draft ToC was reviewed for coherence by key stakeholders (young people, online professionals, and service managers). Results A collaboratively developed ToC was presented. This was divided into the conditions that lead to individuals wanting to access web-based therapy and support (eg, individuals wanting support there and then or quickly), the mode of service delivery (eg, skilled and experienced professionals able to build empathetic relationships with CYP), and the observed and reported changes that occur as a consequence of using the service (eg, individuals being better able to manage current and future situations). Conclusions Developing the ToC helps to shed light on how web-based therapy and support services aid the mental health and well-being of CYP. Furthermore, it helps to understand the development of positive virtual ecosystems and can be used to devise evaluative tools for CYP telepsychology providers.
33
Pringle, M. J., D. E. Allen, T. G. Orton, T. F. A. Bishop, D. W. Butler, B. K. Henry, and R. C. Dalal. "Effects of land-use change and management on soil carbon and nitrogen in the Brigalow Belt, Australia: II. Statistical models to unravel the climate-soil-management interaction." Rangeland Journal 38, no. 5 (2016): 453. http://dx.doi.org/10.1071/rj16010.
Full textAbstract:
The impact of grazing on soil carbon (C) and nitrogen (N) cycles is complex, and across a large area it can be difficult to uncover the magnitude of the effects. Here, we have linked two common approaches to statistical modelling – regression trees and linear mixed models – in a novel way to explore various aspects of soil C and N dynamics for a large, semiarid bioregion where land use is dominated by grazing. The resulting models, which we term RT-LMM, have the pleasing visual appeal of regression trees, and they account for spatial autocorrelation as per a linear mixed model. Our RT-LMM were developed from explanatory variables that related information on climate, soil and past land management. Response variables of interest were: stocks of soil total organic carbon (TOC), soil total nitrogen (TN), and particulate organic C (POC); the ratio of TOC stock to TN stock; and the relative abundance of stable isotopes δ13C and δ15N in the soil. Each variable was sampled at the depth interval 0–0.3 m. The interactions of land use with, in particular, air temperature and soil phosphorus were strong, but three principal management-related effects emerged: (i) the use of fire to clear native vegetation reduced stocks of TOC and TN, and the TOC : TN ratio, by 25%, 19% and 9%, respectively, suggesting that TOC is more sensitive to fire than TN; (ii) conversion of native vegetation to pasture enriched soil with δ13C by 1.7 ‰; subsequent regrowth of the native vegetation among the pasture restored δ13C to its original level but there was no corresponding change in TOC stock; and, (iii) the time elapsed since clearing reduced POC stocks and the TOC : TN ratio.
34
Stahl, Connor, Ewan Crosbie, Paola Angela Bañaga, Grace Betito, Rachel A. Braun, Zenn Marie Cainglet, Maria Obiminda Cambaliza, et al. "Total organic carbon and the contribution from speciated organics in cloud water: airborne data analysis from the CAMP<sup>2</sup>Ex field campaign." Atmospheric Chemistry and Physics 21, no. 18 (September 23, 2021): 14109–29. http://dx.doi.org/10.5194/acp-21-14109-2021.
Full textAbstract:
Abstract. This work focuses on total organic carbon (TOC) and contributing species in cloud water over Southeast Asia using a rare airborne dataset collected during NASA's Cloud, Aerosol and Monsoon Processes Philippines Experiment (CAMP2Ex), in which a wide variety of maritime clouds were studied, including cumulus congestus, altocumulus, altostratus, and cumulus. Knowledge of TOC masses and their contributing species is needed for improved modeling of cloud processing of organics and to understand how aerosols and gases impact and are impacted by clouds. This work relies on 159 samples collected with an axial cyclone cloud-water collector at altitudes of 0.2–6.8 km that had sufficient volume for both TOC and speciated organic composition analysis. Species included monocarboxylic acids (glycolate, acetate, formate, and pyruvate), dicarboxylic acids (glutarate, adipate, succinate, maleate, and oxalate), methanesulfonic acid (MSA), and dimethylamine (DMA). TOC values range between 0.018 and 13.66 ppm C with a mean of 0.902 ppm C. The highest TOC values are observed below 2 km with a general reduction aloft. An exception is samples impacted by biomass burning for which TOC remains enhanced at altitudes as high as 6.5 km (7.048 ppm C). Estimated total organic matter derived from TOC contributes a mean of 30.7 % to total measured mass (inorganics + organics). Speciated organics contribute (on a carbon mass basis) an average of 30.0 % to TOC in the study region and account for an average of 10.3 % to total measured mass. The order of the average contribution of species to TOC, in decreasing contribution of carbon mass, is as follows (±1 standard deviation): acetate (14.7 ± 20.5 %), formate (5.4 ± 9.3 %), oxalate (2.8 ± 4.3 %), DMA (1.7 ± 6.3 %), succinate (1.6 ± 2.4 %), pyruvate (1.3 ± 4.5 %), glycolate (1.3 ± 3.7 %), adipate (1.0 ± 3.6 %), MSA (0.1 ± 0.1 %), glutarate (0.1 ± 0.2 %), and maleate (< 0.1 ± 0.1 %). Approximately 70 % of TOC remains unaccounted for, highlighting the complex nature of organics in the study region; in samples collected in biomass burning plumes, up to 95.6 % of TOC mass is unaccounted for based on the species detected. Consistent with other regions, monocarboxylic acids dominate the speciated organic mass (∼ 75 %) and are about 4 times more abundant than dicarboxylic acids. Samples are categorized into four cases based on back-trajectory history, revealing source-independent similarity between the bulk contributions of monocarboxylic and dicarboxylic acids to TOC (16.03 %–23.66 % and 3.70 %–8.75 %, respectively). Furthermore, acetate, formate, succinate, glutarate, pyruvate, oxalate, and MSA are especially enhanced during biomass burning periods, which is attributed to peat emissions transported from Sumatra and Borneo. Lastly, dust (Ca2+) and sea salt (Na+/Cl-) tracers exhibit strong correlations with speciated organics, supporting how coarse aerosol surfaces interact with these water-soluble organics.
35
Yang, Xin, Honglin Song, Goska Leslie, Christoph Engel, Eric Hahnen, Bernd Auber, Judit Horváth, et al. "Ovarian and Breast Cancer Risks Associated With Pathogenic Variants in RAD51C and RAD51D." JNCI: Journal of the National Cancer Institute 112, no. 12 (February 28, 2020): 1242–50. http://dx.doi.org/10.1093/jnci/djaa030.
Full textAbstract:
Abstract Background The purpose of this study was to estimate precise age-specific tubo-ovarian carcinoma (TOC) and breast cancer (BC) risks for carriers of pathogenic variants in RAD51C and RAD51D. Methods We analyzed data from 6178 families, 125 with pathogenic variants in RAD51C, and 6690 families, 60 with pathogenic variants in RAD51D. TOC and BC relative and cumulative risks were estimated using complex segregation analysis to model the cancer inheritance patterns in families while adjusting for the mode of ascertainment of each family. All statistical tests were two-sided. Results Pathogenic variants in both RAD51C and RAD51D were associated with TOC (RAD51C: relative risk [RR] = 7.55, 95% confidence interval [CI] = 5.60 to 10.19; P = 5 × 10-40; RAD51D: RR = 7.60, 95% CI = 5.61 to 10.30; P = 5 × 10-39) and BC (RAD51C: RR = 1.99, 95% CI = 1.39 to 2.85; P = 1.55 × 10-4; RAD51D: RR = 1.83, 95% CI = 1.24 to 2.72; P = .002). For both RAD51C and RAD51D, there was a suggestion that the TOC relative risks increased with age until around age 60 years and decreased thereafter. The estimated cumulative risks of developing TOC to age 80 years were 11% (95% CI = 6% to 21%) for RAD51C and 13% (95% CI = 7% to 23%) for RAD51D pathogenic variant carriers. The estimated cumulative risks of developing BC to 80 years were 21% (95% CI = 15% to 29%) for RAD51C and 20% (95% CI = 14% to 28%) for RAD51D pathogenic variant carriers. Both TOC and BC risks for RAD51C and RAD51D pathogenic variant carriers varied by cancer family history and could be as high as 32–36% for TOC, for carriers with two first-degree relatives diagnosed with TOC, or 44–46% for BC, for carriers with two first-degree relatives diagnosed with BC. Conclusions These estimates will facilitate the genetic counseling of RAD51C and RAD51D pathogenic variant carriers and justify the incorporation of RAD51C and RAD51D into cancer risk prediction models.
36
Arensman, Bodille, Cornelie van Waegeningh, and Margit van Wessel. "Twinning “Practices of Change” With “Theory of Change”." American Journal of Evaluation 39, no. 2 (September 1, 2017): 221–36. http://dx.doi.org/10.1177/1098214017727364.
Full textAbstract:
Theory of change (ToC) is currently the approach for the evaluation and planning of international development programs. This approach is considered especially suitable for complex interventions. We question this assumption and argue that ToC’s focus on cause–effect logic and intended outcomes does not do justice to the recursive nature of complex interventions such as advocacy. Supported by our work as evaluators, and specifically our case study of an advocacy program on child rights, we illustrate how advocacy evolves through recursive interactions, with outcomes that are emergent rather than predictable. We propose putting “practices of change” at the center by emphasizing human interactions, using the analytical lenses of strategies as practice and recursiveness. This provides room for emergent outcomes and implies a different use of ToC. In this article, we make a clear distinction between theoretical reality models and the real world of practices.
37
Huang, He, Yuan Gao, Chao Ma, Matthew M. Jones, Christian Zeeden, Daniel E. Ibarra, Huaichun Wu, and Chengshan Wang. "Organic carbon burial is paced by a ~173-ka obliquity cycle in the middle to high latitudes." Science Advances 7, no. 28 (July 2021): eabf9489. http://dx.doi.org/10.1126/sciadv.abf9489.
Full textAbstract:
Earth’s climate system is complex and inherently nonlinear, which can induce some extraneous cycles in paleoclimatic proxies at orbital time scales. The paleoenvironmental consequences of these extraneous cycles are debated owing to their complex origin. Here, we compile high-resolution datasets of total organic carbon (TOC) and stable carbon isotope (δ13Corg) datasets to investigate organic carbon burial processes in middle to high latitudes. Our results document a robust cyclicity of ~173 thousand years (ka) in both TOC and δ13Corg. The ~173-ka obliquity–related forcing signal was amplified by internal climate feedbacks of the carbon cycle under different geographic and climate conditions, which control a series of sensitive climatic processes. In addition, our new and compiled records from multiple proxies confirm the presence of the obliquity amplitude modulation (AM) cycle during the Mesozoic and Cenozoic and indicate the usefulness of the ~173-ka cycle as geochronometer and for paleoclimatic interpretation.
38
Matsui, S., Y. Okawa, and R. Ota. "Experience of 16 Years' Operation and Maintenance of the Fukashiba Industrial Wastewater Treatment Plant of the Kashima Petrochemical Complex – II. Biodegradability of 37 Organic Substances and 28 Process Wastewaters." Water Science and Technology 20, no. 10 (October 1, 1988): 201–10. http://dx.doi.org/10.2166/wst.1988.0138.
Full textAbstract:
Twenty-eight process wastewaters and thirty-seven organic substances identified in the wastewater of the Kashima petrochemical complex were subjected to biodegradability tests. The tests consisted of the activated sludge degradability method and a supplementary test using the respiration meter method. Both tests utilized the activated sludge of the Fukashiba industrial wastewater treatment plant, which was acclimatized to the wastewater and organic substances. The 28 process wastewaters were classified into biodegradable, less biodegradable, and non-biodegradable according to the percentage TOC removal and the BOD5/TOC ratio of the wastewater. The 37 organic substances were also classified into biodegradable, less biodegradable and non-biodegradable according to TOC and CODMn removal. In general, chlorinated compounds, nitro-aromatics and polymerized compounds were difficult to biodegrade. From the biodegradability tests of the factory wastewaters, it was found that the refractory CODMn loads of these factories contributed to the load remaining in the effluent of the wastewater treatment plant. Various improvements were made to reduce the discharge of refractory substances from the factories.
39
Selmer, Daniela, Reingard Senekowitsch-Schmidtke, W. Schneider, and E. F. Elstner. "Binding and Uptake of 125Iodine-Labelled, Oxidized Low Density Lipoprotein by Macrophages: Comparism of the Effects of a-Tocopherol, Probucol, Pyridoxal-5'-phosphate and Magnesium-pyridoxal-5'-phosphate-glutamate." Zeitschrift für Naturforschung C 52, no. 1-2 (February 1, 1997): 97–104. http://dx.doi.org/10.1515/znc-1997-1-217.
Full textAbstract:
Abstract Specific and unspecific binding and uptake (internalization) by macrophages of 125iodine -labelled, copper-oxidized human low density lipoprotein is differently influenced by the anti oxidants α-tocopherol (α-Toc), probucol (Prob), pyridoxal-5'-phosphate (PP) and the magnesium-pyridoxal-5'-phosphate glutamate complex (MPPG). Binding as well as internalization, mediated by the so-called "scavenger receptor" is lower in the presence of MPPG whereas both specific binding and internalization are enhanced. The comparison of the effects in vitro allows a rating of the potentially anti-atherogenic and thus protective effects of the tested substances as follows: MPPG > PP > α-Toc > Prob.
40
Bogacki, Jan, Piotr Marcinowski, and Balkess El-Khozondar. "Treatment of Landfill Leachates with Combined Acidification/Coagulation and The Fe0/H2O2 Process." Water 11, no. 2 (January 23, 2019): 194. http://dx.doi.org/10.3390/w11020194.
Full textAbstract:
One of the major environmental concerns associated with waste disposal is the large amount of generated landfill leachates (LL), which are considered a type of wastewater with a complex composition. There is an urgent need to find an effective LL treatment method. LL were subjected to pretreatment followed by the Fe0/H2O2 process. Pretreatment efficiency was coagulation at pH 6.0 >> coagulation at pH 9.0 > acidification at pH 3.0. Coagulation at pH 6.0 in an optimal Fe3+ dose of 1000 mg/L decreased total organic carbon (TOC) from the initial concentration of 1061 mg/L to 491 mg/L while acidification to pH 3.0 decreased TOC to 824 mg/L. After acidification, the Fe0/H2O2 process with 8000/9200 mg/L Fe0/H2O2 reagent doses decreased TOC to 499 mg/L after a processing time of 60 min. Performance of the Fe0/H2O2 process after coagulation at pH 6.0 for optimal Fe0/H2O2 8000/5540 mg/L reagent doses decreased TOC to 268 mg/L (75% TOC removal). Treatment of landfill leachates with combined process coagulation and Fe0/H2O2 also increased their susceptibility to biodegradation, expressed as the biochemical oxygen demand/chemical oxygen demand (BOD5/COD) ratio from 0.13 to 0.43, allowing LL to be considered as susceptible to biodegradation. Fe0/H2O2 process kinetics was described. A statistical analysis confirmed the obtained results. The proposed method can be successfully applied for LL treatment.
41
Yu, Kun, Yiwen Ju, Yanhui Yang, Peng Qiao, Wuyang Li, Liting Ju, Hongjian Zhu, Cheng Huang, and Hongye Feng. "Effect of Composition on the Micropore Structure of Non-Marine Coal-Bearing Shale: A Case Study of Permian Strata in the Qinshui Basin, China." Journal of Nanoscience and Nanotechnology 21, no. 1 (January 1, 2021): 741–49. http://dx.doi.org/10.1166/jnn.2021.18563.
Full textAbstract:
The nanopore network in organic-rich shale plays a key role in shale gas storage and migration, and micropores are an important structural unit in connecting the migration channel. In this study, we selected six non-marine coal-bearing shales from the Qinshui Basin to investigate the effect of composition on micropore structure using X-ray diffraction, total organic carbon (TOC), vitrinite reflectance, and CO2 adsorption methods. The results indicate that non-marine shale with higher TOC content possesses more micropores, leading to a more complex pore structure and improving the heterogeneity of shale reservoirs. With the increase in TOC content, the micropore surface area and micropore volume clearly increases, which greatly improves the gas storage space in shale reservoirs. The thermal evolution of organic matter promotes the development of micropores to a certain extent in non-marine shale. Clay minerals possess a rough surface and develop more micropores, and their influence on the micropore structure of non-marine shale is relatively strong, while terrestrial quartz exhibits significant micropore development. The obviously positive correlations between micropore volume and kaolinite, chlorite contents in the non-marine shale suggest that kaolinite and chlorite make a certain contribution to micropore volume. The characteristics of micropore structures in coal mainly depend on lithotypes, TOC content, and ash content, while clay content, quartz content, and TOC content are the key factors controlling the formation of micropores in non-marine shale.
42
Asada, Yuka, Kelsey Gilmet, Christina Welter, Gina Massuda-Barnett, Devangna A. Kapadia, and Michael Fagen. "Applying Theory of Change to a Structural Change Initiative: Evaluation of Model Communities in a Diverse County." Health Education & Behavior 46, no. 3 (December 28, 2018): 377–87. http://dx.doi.org/10.1177/1090198118818233.
Full textAbstract:
Structural change approaches, also called policy, systems, and environmental change approaches, have been increasingly promoted and adopted by public ealth agencies in the past decade. These interventions require attention to multilevel, complex and contextual influences on individual and community health outcomes, requiring a sound theoretical framework that links the many processes and outcomes over time. The Model Communities program of Cook County, Illinois Communities Putting Prevention to Work program employed a theory of change (ToC) framework to inform the evaluations’ design and execution. The main objective of this study was to apply findings from the longitudinal multiple case study evaluation to develop an adapted ToC. We conducted 97 key informant interviews across three waves, with a focus on Model Communities program participants’, Communities Putting Prevention to Work staff, and technical assistance providers’ experiences over time. Four analysts organized and coded the data using qualitative software; exploratory functions and data matrices were employed throughout three waves of analysis. Adaptations to the ToC included the addition of a construct, “change readiness,” as well as refinements to constructs: organizational capacity (human capital, technical assistance, informal and formal leadership), local partnerships, and the importance of sustainability. The findings offer a data-informed theoretical framework that may be considered for use in evaluations of structural change interventions in complex and diverse counties.
43
Bacelar-Silva, Gustavo M., James F. Cox, Humberto R. Baptista, and Pedro Pereira Rodrigues. "Identifying and Addressing the Underlying Core Problems in Healthcare Environments: An Illustration Using an Emergency Department Game." International Journal of Environmental Research and Public Health 18, no. 19 (September 25, 2021): 10083. http://dx.doi.org/10.3390/ijerph181910083.
Full textAbstract:
The emergency department (ED) crowding is a critical healthcare issue worldwide that leads to long waits and poorer healthcare outcomes. Goldratt’s theory of constraints (TOC) has been used effectively to improve such problematic environments for more than three decades. While most TOC solutions are simple, with many viewing them as purely common sense, they represent paradigm shifts in how to manage complex, uncertain, and silo environments. Goldratt used a simple dice game with a straight flow (I-shape) to illustrate the impact of dependent resources and statistical fluctuations in managing resources. Additionally, games help to overcome resistance to change and gain ownership by having participants develop their solutions. This new cooperative game illustrates an ED environment where patients may follow different care pathways according to their clinical needs, timeliness of care is measured in minutes, the demand is highly uncertain, and treatment must frequently start almost immediately. A Monte Carlo simulation validated the TOC solution to this ED game, achieving results similar to the real TOC’s implementations. Moreover, this article provides a thorough process to Socratically introduce TOC to healthcare professionals and others to recognize that the EDs’ (like other healthcare systems’) core problem is the traditional approach to managing them.
44
Medel, Alejandro, Erika Bustos, Karen Esquivel, Luis A. Godínez, and Yunny Meas. "Electrochemical Incineration of Phenolic Compounds from the Hydrocarbon Industry Using Boron-Doped Diamond Electrodes." International Journal of Photoenergy 2012 (2012): 1–6. http://dx.doi.org/10.1155/2012/681875.
Full textAbstract:
Electrochemical incineration using boron-doped diamond electrodes was applied to samples obtained from a refinery and compared to the photo-electro-Fenton process in order to selectively eliminate the phenol and phenolic compounds from a complex matrix. Due to the complex chemical composition of the sample, a pretreatment to the sample in order to isolate the phenolic compounds was applied. The effects of the pretreatment and of pH on the degradation of the phenolic compounds were evaluated. The results indicate that the use of a boron-doped diamond electrode in an electrochemical incineration process mineralizes 99.5% of the phenolic sample content. Working in acidic medium (pH = 1), and applying 2 A at 298 K under constant stirring for 2 hours, also results in the incineration of the reaction intermediates reflected by 97% removal of TOC. In contrast, the photo-electro-Fenton process results in 99.9% oxidation of phenolic compounds with only a 25.69% removal of TOC.
45
Xie, Weidong, Meng Wang, and Hongyue Duan. "Adsorption Characteristics and Controlling Factors of CH4 on Coal-Measure Shale, Hedong Coalfield." Minerals 11, no. 1 (January 11, 2021): 63. http://dx.doi.org/10.3390/min11010063.
Full textAbstract:
Adsorbed gas is one of the crucial occurrences in shale gas reservoirs; thus, it is of great significance to ascertain the adsorption capacity of shale and the adsorption characteristics of CH4. In this investigation, the Taiyuan–Shanxi Formations’ coal-measure shale gas reservoir of the Carboniferous–Permian era in the Hedong Coalfield was treated as the research target. Our results exhibit that the shale samples were characterized by a high total organic carbon (TOC) and over to high-over maturity, with an average TOC of 2.45% and average Ro of 2.59%. The mineral composition was dominated by clay (62% on average) and quartz (22.45% on average), and clay was mainly composed of kaolinite and illite. The Langmuir model showed a perfect fitting degree to the experimental data: VL was in the range of 0.01 cm3/g to 0.77 cm3/g and PL was in the range of 0.23–8.58 MPa. In addition, the fitting degree depicted a linear negative correlation versus TOC, while mineral composition did not exhibit a significant effect on the fitting degree, which was caused by the complex pore structure of organic matter, and the applicability of the monolayer adsorption theory was lower than that of CH4 adsorption on the mineral’s pore surface. An apparent linear positive correlation of VL versus the TOC value was recorded; furthermore, the normalized VL increased with the growth of the total content of clay mineral (TCCM), decreased with the growth of the total content of brittle mineral (TCBM), while there was no obvious correlation of normalized VL versus kaolinite, illite and quartz content. The huge amount of micropores and complex internal structure led to organic matter possessing a strong adsorption capacity for CH4, and clay minerals also promoted adsorption due to the development of interlayer pores and intergranular pores.
46
Xie, Weidong, Meng Wang, and Hongyue Duan. "Adsorption Characteristics and Controlling Factors of CH4 on Coal-Measure Shale, Hedong Coalfield." Minerals 11, no. 1 (January 11, 2021): 63. http://dx.doi.org/10.3390/min11010063.
Full textAbstract:
Adsorbed gas is one of the crucial occurrences in shale gas reservoirs; thus, it is of great significance to ascertain the adsorption capacity of shale and the adsorption characteristics of CH4. In this investigation, the Taiyuan–Shanxi Formations’ coal-measure shale gas reservoir of the Carboniferous–Permian era in the Hedong Coalfield was treated as the research target. Our results exhibit that the shale samples were characterized by a high total organic carbon (TOC) and over to high-over maturity, with an average TOC of 2.45% and average Ro of 2.59%. The mineral composition was dominated by clay (62% on average) and quartz (22.45% on average), and clay was mainly composed of kaolinite and illite. The Langmuir model showed a perfect fitting degree to the experimental data: VL was in the range of 0.01 cm3/g to 0.77 cm3/g and PL was in the range of 0.23–8.58 MPa. In addition, the fitting degree depicted a linear negative correlation versus TOC, while mineral composition did not exhibit a significant effect on the fitting degree, which was caused by the complex pore structure of organic matter, and the applicability of the monolayer adsorption theory was lower than that of CH4 adsorption on the mineral’s pore surface. An apparent linear positive correlation of VL versus the TOC value was recorded; furthermore, the normalized VL increased with the growth of the total content of clay mineral (TCCM), decreased with the growth of the total content of brittle mineral (TCBM), while there was no obvious correlation of normalized VL versus kaolinite, illite and quartz content. The huge amount of micropores and complex internal structure led to organic matter possessing a strong adsorption capacity for CH4, and clay minerals also promoted adsorption due to the development of interlayer pores and intergranular pores.
47
Hirakawa, Yoshihisa, Fabien Burki, and Patrick J. Keeling. "Genome-Based Reconstruction of the Protein Import Machinery in the Secondary Plastid of a Chlorarachniophyte Alga." Eukaryotic Cell 11, no. 3 (January 20, 2012): 324–33. http://dx.doi.org/10.1128/ec.05264-11.
Full textAbstract:
ABSTRACT Most plastid proteins are encoded by their nuclear genomes and need to be targeted across multiple envelope membranes. In vascular plants, the translocons at the outer and inner envelope membranes of chloroplasts (TOC and TIC, respectively) facilitate transport across the two plastid membranes. In contrast, several algal groups harbor more complex plastids, the so-called secondary plastids, which are surrounded by three or four membranes, but the plastid protein import machinery (in particular, how proteins cross the membrane corresponding to the secondary endosymbiont plasma membrane) remains unexplored in many of these algae. To reconstruct the putative protein import machinery of a secondary plastid, we used the chlorarachniophyte alga Bigelowiella natans , whose plastid is bounded by four membranes and still possesses a relict nucleus of a green algal endosymbiont (the nucleomorph) in the intermembrane space. We identified nine homologs of plant-like TOC/TIC components in the recently sequenced B. natans nuclear genome, adding to the two that remain in the nucleomorph genome ( B. natans TOC75 [BnTOC75] and BnTIC20). All of these proteins were predicted to be localized to the plastid and might function in the inner two membranes. We also show that the homologs of a protein, Der1, that is known to mediate transport across the second membrane in the several lineages with secondary plastids of red algal origin is not associated with plastid protein targeting in B. natans . How plastid proteins cross this membrane remains a mystery, but it is clear that the protein transport machinery of chlorarachniophyte plastids differs from that of red algal secondary plastids.
48
Ahmadian, Mohammad, Sohyla Reshadat, Nader Yousefi, Seyed Hamed Mirhossieni, Mohammad Reza Zare, Seyed Ramin Ghasemi, Nader Rajabi Gilan, Razieh Khamutian, and Ali Fatehizadeh. "Municipal Leachate Treatment by Fenton Process: Effect of Some Variable and Kinetics." Journal of Environmental and Public Health 2013 (2013): 1–6. http://dx.doi.org/10.1155/2013/169682.
Full textAbstract:
Due to complex composition of leachate, the comprehensive leachate treatment methods have been not demonstrated. Moreover, the improper management of leachate can lead to many environmental problems. The aim of this study was application of Fenton process for decreasing the major pollutants of landfill leachate on Kermanshah city. The leachate was collected from Kermanshah landfill site and treated by Fenton process. The effect of various parameters including solution pH, Fe2+and H2O2dosage, Fe2+/H2O2molar ratio, and reaction time was investigated. The result showed that with increasing Fe2+and H2O2dosage, Fe2+/H2O2molar ratio, and reaction time, the COD, TOC, TSS, and color removal increased. The maximum COD, TOC, TSS, and color removal were obtained at low pH (pH: 3). The kinetic data were analyzed in term of zero-order, first-order, and second-order expressions. First-order kinetic model described the removal of COD, TOC, TSS, and color from leachate better than two other kinetic models. In spite of extremely difficulty of leachate treatment, the previous results seem rather encouraging on the application of Fenton’s oxidation.
49
Lin, Yi, and Mehrab Mehrvar. "Photocatalytic Treatment of An Actual Confectionery Wastewater Using Ag/TiO2/Fe2O3: Optimization of Photocatalytic Reactions Using Surface Response Methodology." Catalysts 8, no. 10 (September 21, 2018): 409. http://dx.doi.org/10.3390/catal8100409.
Full textAbstract:
Titanium dioxide (TiO2) photocatalysis is one of the most commonly studied advanced oxidation processes (AOPs) for the mineralization of deleterious and recalcitrant compounds present in wastewater as it is stable, inexpensive, and effective. Out of all, doping with metal and non-metals, and the heterojunction with another semiconductor were proven to be efficient methods in enhancing the degradation of organic pollutants under ultraviolet (UV) and visible light. However, complex degradation processes in the treatment of an actual wastewater are difficult to model and optimize. In the present study, the application of a modified photocatalyst, Ag/TiO2/Fe2O3, for the degradation of an actual confectionery wastewater was investigated. Factorial studies and statistical design of experiments using the Box-Behnken method along with response surface methodology (RSM) were employed to identify the individual and cross-factor effects of independent parameters, including light wavelength (nm), photocatalyst concentration (g/L), initial pH, and initial total organic carbon (TOC) concentration (g/L). The maximum TOC removal at optimum conditions of light wavelength (254 nm), pH (4.68), photocatalyst dosage (480 mg/L), and initial TOC concentration (11,126.5 mg/L) was determined through the numerical optimization method (9.78%) and validated with experimental data (9.42%). Finally, the first-order rate constant with respect to TOC was found to be 0.0005 min−1 with a residual value of 0.998.
50
O’Melia, C. R., W. C. Becker, and K. K. Au. "Removal of Humic Substances by Coagulation." Water Science and Technology 40, no. 9 (November 1, 1999): 47–54. http://dx.doi.org/10.2166/wst.1999.0440.
Full textAbstract:
Measurements and modeling of the adsorption of natural organic matter (NOM) on oxide surfaces are presented and compared. Agreement is good and supports the view that the adsorption of NOM on oxides depends significantly on complex formation reactions between specific sites on oxide surfaces and functional groups on the NOM. Coagulant requirements can and often are set by the total organic carbon (TOC) concentration in a water source. Frequently there is a stoichiometric relationship between the required coagulant dosage and the TOC of the water to be treated. Other important factors include pH and the concentration of divalent cations. Ozone may benefit or retard coagulation, depending on coagulant type and the water quality characteristic that is dominant in setting the optimum coagulant dose.