Journal articles: 'R3A2'

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Salim, Ramadan, Akshay Gundla, B. Shane Underwood, and Kamil E. Kaloush. "Effect of MSCR Percent Recovery on Performance of Polymer Modified Asphalt Mixtures." Transportation Research Record: Journal of the Transportation Research Board 2673, no. 5 (April 8, 2019): 308–19. http://dx.doi.org/10.1177/0361198119841283.

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The AASHTO M332 specification includes a relationship between the non-recoverable creep compliance at 3.2 kPa ( Jnr3.2) and the percent of elastic recovery ( R3.2) from the multiple stress creep and recovery (MSCR) test. Justification for the exact position of this curve based on binder performance is largely undocumented in the technical literature as is the singular effect of higher or lower R3.2 values on mixture performance. In this study, nine binders were tested to evaluate the effect of R3.2 on the performance of asphalt mixtures. Binders with similar Jnr3.2 and varying MSCR R3.2 were divided into four groups based on their Jnr3.2 value. Comparisons were made based on results obtained from the dynamic modulus test, Hamburg wheel tracking test, and axial fatigue test. Based on these tests, it was shown that R3.2 had a strong relationship to the dynamic modulus of asphalt mixtures especially at intermediate and high temperatures. Binders with lower R3.2 had a higher dynamic modulus but showed no correlation to phase angle. Both modulus and phase angle of the mixture correlated to the binder shear modulus and phase angle. Binders with high R3.2 had a greater fatigue resistance and the effect is quite noticeable. However, R3.2 was shown to have little to no effect on the rutting resistance of the asphalt mixtures for the temperatures tested in this study. Finally, an alternative Jnr3.2 versus R3.2 relationship based on the results of this study is also presented.

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Cánovas-Márquez, José Tomás, Sebastian Falk, Francisco E. Nicolás, Subramanian Padmanabhan, Rubén Zapata-Pérez, Álvaro Sánchez-Ferrer, Eusebio Navarro, and Victoriano Garre. "A ribonuclease III involved in virulence of Mucorales fungi has evolved to cut exclusively single-stranded RNA." Nucleic Acids Research 49, no. 9 (April 20, 2021): 5294–307. http://dx.doi.org/10.1093/nar/gkab238.

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Abstract Members of the ribonuclease III (RNase III) family regulate gene expression by processing double-stranded RNA (dsRNA). This family includes eukaryotic Dicer and Drosha enzymes that generate small dsRNAs in the RNA interference (RNAi) pathway. The fungus Mucor lusitanicus, which causes the deadly infection mucormycosis, has a complex RNAi system encompassing a non-canonical RNAi pathway (NCRIP) that regulates virulence by degrading specific mRNAs. In this pathway, Dicer function is replaced by R3B2, an atypical class I RNase III, and small single-stranded RNAs (ssRNAs) are produced instead of small dsRNA as Dicer-dependent RNAi pathways. Here, we show that R3B2 forms a homodimer that binds to ssRNA and dsRNA molecules, but exclusively cuts ssRNA, in contrast to all known RNase III. The dsRNA cleavage inability stems from its unusual RNase III domain (RIIID) because its replacement by a canonical RIIID allows dsRNA processing. A crystal structure of R3B2 RIIID resembles canonical RIIIDs, despite the low sequence conservation. However, the groove that accommodates dsRNA in canonical RNases III is narrower in the R3B2 homodimer, suggesting that this feature could be responsible for the cleavage specificity for ssRNA. Conservation of this activity in R3B2 proteins from other mucormycosis-causing Mucorales fungi indicates an early evolutionary acquisition.

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Ding, De Feng, Shi Jie Liu, Chao Yu Zheng, Wen Sheng Yu, and Wu Chen. "Performance Comparison among Heat Pump Water Heaters Working with R32, R134a and the Mixture of R32/R134a." Advanced Materials Research 512-515 (May 2012): 1295–98. http://dx.doi.org/10.4028/www.scientific.net/amr.512-515.1295.

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A general air-source heat pump water heater originally designed to work with R134a was reconstructed as experimental rig for performance studies on systems using different refrigerants including R32, R134a and the mixture of R32/R134a which mass ratio is 1:5. Experimental results showed that the power consumption of the heat pump water heater charged individually with R32 would greatly exceed the system’s original pre-set maximum input power. When the leaving water temperature was increased from 18°C to 58°C, the average discharge temperature of the heat pump charged with R32/R134a mixture was 13.6% higher than that with R134a. The average power consumption of the heat pump with R134a was 253.5W less than that with R32/R134a mixture. However, the average COP (Coefficient of Performance) obtained by that with R32/R134a mixture was 0.83 higher than that with R134a.

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Doiphode, Pushpak, Vignesh Lakshmanan, and Indraneel Samanta. "Experimental and Numerical Study of Cooling Performance of Air Conditioner Using R32/CO2 Refrigerant Mixture." International Journal of Air-Conditioning and Refrigeration 27, no. 02 (June 2019): 1950019. http://dx.doi.org/10.1142/s2010132519500196.

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Conventional refrigerants such as chlorofluorocarbons and hydrochlorofluorocarbons have high values of global warming potential (GWP) and ozone depletion (ODP). HVAC&R engineers and designers are exploring alternate refrigerants having low ODP and GWP. At present, R32 refrigerant is being considered as an alternative to the conventional refrigerants in domestic air conditioners by many manufacturers and countries. This study analyzes the steady-state cooling performance of a split air conditioner using R32(CH2F2) and R32/CO2 (Carbon Dioxide) mixture having lower GWP. The performance of the air conditioner with R32 and four different compositions of R32/CO2 mixture is studied experimentally and numerically. A comparative analysis of performance characteristics such as cooling capacity, total energy consumption, energy efficiency, operating pressures and temperatures is presented in this study.

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Duran, Robert. "New shuttle vectors forRhodococcus sp. R312 (formerlyBrevibacterium sp. R312), a nitrile hydratase producing strain." Journal of Basic Microbiology 38, no. 2 (May 1998): 101–6. http://dx.doi.org/10.1002/(sici)1521-4028(199805)38:2<101::aid-jobm101>3.0.co;2-p.

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Segretin, María Eugenia, Marina Pais, Marina Franceschetti, Angela Chaparro-Garcia, Jorunn I. B. Bos, Mark J. Banfield, and Sophien Kamoun. "Single Amino Acid Mutations in the Potato Immune Receptor R3a Expand Response to Phytophthora Effectors." Molecular Plant-Microbe Interactions® 27, no. 7 (July 2014): 624–37. http://dx.doi.org/10.1094/mpmi-02-14-0040-r.

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Both plants and animals rely on nucleotide-binding domain and leucine-rich repeat-containing (NB-LRR or NLR) proteins to respond to invading pathogens and activate immune responses. How plant NB-LRR proteins respond to pathogens is poorly understood. We undertook a gain-of-function random mutagenesis screen of the potato NB-LRR immune receptor R3a to study how this protein responds to the effector protein AVR3a from the oomycete pathogen Phytophthora infestans. R3a response can be extended to the stealthy AVR3aEM isoform of the effector while retaining recognition of AVR3aKI. Each one of eight single amino acid mutations is sufficient to expand the R3a response to AVR3aEM and other AVR3a variants. These mutations occur across the R3a protein, from the N terminus to different regions of the LRR domain. Further characterization of these R3a mutants revealed that at least one of them was sensitized, exhibiting a stronger response than the wild-type R3a protein to AVR3aKI. Remarkably, the N336Y mutation, near the R3a nucleotide-binding pocket, conferred response to the effector protein PcAVR3a4 from the vegetable pathogen P. capsici. This work contributes to understanding how NB-LRR receptor specificity can be modulated. Together with knowledge of pathogen effector diversity, this strategy can be exploited to develop synthetic immune receptors.

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Zoteyeva, Nadezhda, Ilze Skrabule, Ieva Mežaka, Daiga Vilcāne, Guna Usele, and Nils Rostoks. "The impact of R1and R3a genes on tuber resistance to late blight of the potato breeding clones." Proceedings of the Latvian Academy of Sciences. Section B. Natural, Exact, and Applied Sciences. 70, no. 2 (April 1, 2016): 58–63. http://dx.doi.org/10.1515/prolas-2016-0010.

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Abstract Potato breeding clones were evaluated for resistance to late blight (agent Phytophthora infestans) using tuber inoculation tests and for presence of the resistance alleles of R1 and R3a genes in polymerase chain reaction tests. Among clones tested those expressing high, moderate and low resistance were identified. The data were analysed for the impact of R1 and R3a genes on tuber resistance to late blight in tested plant material. In previous evaluations performed on smaller amount of clones the tuber resistance levels significantly depended on presence/absence of the resistance allele of R3a gene and did not depend on presence of R1 gene allele. In the current study the statistical analyses did not prove the significant difference in resistance levels depending on presence of the resistance alleles, neither of R1 gene, nor of R3a gene. Tuber resistant clones bearing R3a gene resistance alleles still noticeably prevailed over the clones bearing the alleles of R1 gene as well as over the clones bearing the no resistance alleles of both genes. In several cases the resistance of clones with detected resistance allele of R1 gene was higher compared to those derived from the same crosses and showing amplification of the allele of R3a gene or those with no resistance alleles. Clones accumulating the resistance alleles of both (R1 and R3a) genes expressed high tuber resistance accompanied by necrotic reaction.

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Reszka-Blanco, Natalia J., Vijay Sivaraman, Liguo Zhang, and Lishan Su. "HIV-1 Env and Nef Cooperatively Contribute to Plasmacytoid Dendritic Cell Activation via CD4-Dependent Mechanisms." Journal of Virology 89, no. 15 (May 13, 2015): 7604–11. http://dx.doi.org/10.1128/jvi.00695-15.

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ABSTRACTPlasmacytoid dendritic cells (pDCs) are the major source of type I IFN (IFN-I) in response to human immunodeficiency virus type 1 (HIV-1) infection. pDCs are rapidly activated during HIV-1 infection and are implicated in reducing the early viral load, as well as contributing to HIV-1-induced pathogenesis. However, most cell-free HIV-1 isolates are inefficient in activating human pDCs, and the mechanisms of HIV-1 recognition by pDCs and pDC activation are not clearly defined. In this study, we report that two genetically similar HIV-1 variants (R3A and R3B) isolated from a rapid progressor differentially activated pDCs to produce alpha interferon (IFN-α). The highly pathogenic R3A efficiently activated pDCs to induce robust IFN-α production, while the less pathogenic R3B did not. The viral determinant for efficient pDC activation was mapped to the V1V2 region of R3A Env, which also correlated with enhanced CD4 binding activity. Furthermore, we showed that the Nef protein was also required for the activation of pDCs by R3A. Analysis of a panel of R3A Nef functional mutants demonstrated that Nef domains involved in CD4 downregulation were necessary for R3A to activate pDCs. Our data indicate that R3A-induced pDC activation depends on (i) the high affinity of R3A Env for binding the CD4 receptor and (ii) Nef activity, which is involved in CD4 downregulation. Our findings provide new insights into the mechanism by which HIV-1 induces IFN-α in pDCs, which contributes to pathogenesis.IMPORTANCEPlasmacytoid dendritic cells (pDCs) are the major type I interferon (IFN-I)-producing cells, and IFN-I actually contributes to pathogenesis during chronic viral infections. How HIV-1 activates pDCs and the roles of pDCs/IFN-I in HIV-1 pathogenesis remain unclear. We report here that the highly pathogenic HIV R3A efficiently activated pDCs to induce IFN-α production, while most HIV-1 isolates are inefficient in activating pDCs. We have discovered that R3A-induced pDC activation depends on (i) the high affinity of R3A Env for binding the CD4 receptor and (ii) Nef activity, which is involved in CD4 downregulation. Our findings thus provide new insights into the mechanism by which HIV-1 induces IFN-α in pDCs and contributes to HIV-1 pathogenesis. These novel findings will be of great interest to those working on the roles of IFN and pDCs in HIV-1 pathogenesis in general and on the interaction of HIV-1 with pDCs in particular.

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Elinder, Fredrik, Roope Männikkö, and H. Peter Larsson. "S4 Charges Move Close to Residues in the Pore Domain during Activation in a K Channel." Journal of General Physiology 118, no. 1 (July 1, 2001): 1–10. http://dx.doi.org/10.1085/jgp.118.1.1-a.

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Voltage-gated ion channels respond to changes in the transmembrane voltage by opening or closing their ion conducting pore. The positively charged fourth transmembrane segment (S4) has been identified as the main voltage sensor, but the mechanisms of coupling between the voltage sensor and the gates are still unknown. Obtaining information about the location and the exact motion of S4 is an important step toward an understanding of these coupling mechanisms. In previous studies we have shown that the extracellular end of S4 is located close to segment 5 (S5). The purpose of the present study is to estimate the location of S4 charges in both resting and activated states. We measured the modification rates by differently charged methanethiosulfonate regents of two residues in the extracellular end of S5 in the Shaker K channel (418C and 419C). When S4 moves to its activated state, the modification rate by the negatively charged sodium (2-sulfonatoethyl) methanethiosulfonate (MTSES−) increases significantly more than the modification rate by the positively charged [2-(trimethylammonium)ethyl] methanethiosulfonate, bromide (MTSET+). This indicates that the positive S4 charges are moving close to 418C and 419C in S5 during activation. Neutralization of the most external charge of S4 (R362), shows that R362 in its activated state electrostatically affects the environment at 418C by 19 mV. In contrast, R362 in its resting state has no effect on 418C. This suggests that, during activation of the channel, R362 moves from a position far away (>20 Å) to a position close (8 Å) to 418C. Despite its close approach to E418, a residue shown to be important in slow inactivation, R362 has no effect on slow inactivation or the recovery from slow inactivation. This refutes previous models for slow inactivation with an electrostatic S4-to-gate coupling. Instead, we propose a model with an allosteric mechanism for the S4-to-gate coupling.

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Lambrechts, Christel, and Pierre Galzy. "Esterase Activities ofBrevihacteriumsp. R312 andBrevihacterium linens62." Bioscience, Biotechnology, and Biochemistry 59, no. 8 (January 1995): 1464–71. http://dx.doi.org/10.1271/bbb.59.1464.

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Cui, Junwei, Shengshan Bi, Xianyang Meng, and Jiangtao Wu. "Surface Tension and Liquid Viscosity of R32+R1234yf and R32+R1234ze." Journal of Chemical & Engineering Data 61, no. 2 (January 12, 2016): 950–57. http://dx.doi.org/10.1021/acs.jced.5b00798.

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Tian, Jiameng, Bin Chen, Zhifu Zhou, and Dong Li. "Theoretical Study on Cryogen Spray Cooling in Laser Treatment of Ota’s Nevus: Comparison and Optimization of R134a, R404A and R32." Energies 13, no. 21 (October 28, 2020): 5647. http://dx.doi.org/10.3390/en13215647.

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Cryogen spray cooling (CSC) could be applied clinically for the laser therapy of Ota’s nevus, a dermal hyperplastic pigmented disease with a morbidity rate of 0.1–0.6% in the Asian population. An accurate, efficient, complete simulation system that considers the entire spray cooling process, including cryogen flow in the tube nozzle, spray dynamics and internal phase change heat transfer (cold injury) in skin tissue, was established to determine suitable cryogen and cooling parameters. The optimum spray distances for R134a, R404A and R32 were determined to be 66.0, 43.1 and 22.5 mm, respectively. The corresponding maximum surface heat fluxes were 363.5, 459.9, and 603.6 kW∙m−2, respectively. The maximum surface heat flux of R32 with small spray distance was 1.66 times as large as that of R134a, indicating the potentially good cooling performance and precise targeted cooling of R32 during the laser therapy of Ota’s nevus. The cooling durations that caused cold injury of skin tissue were 2.3, 1.4, and 1.1 s for R134a, R404A, and R32, respectively. The interval between CSC and laser irradiation was optimized to 90–162 ms for R134a, R404A and R32, in consideration of the cooling effect, depth, uniformity, and risk of cold injury.

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Augot, D., M. Abrous, D. Rondelaud, G. Dreyfuss, and J. Cabaret. "Fasciola hepatica: an unusual development of redial generations in an isolate of Lymnaea truncatula." Journal of Helminthology 73, no. 1 (January 1999): 27–30. http://dx.doi.org/10.1017/s0022149x99000037.

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Single-miracidium infections of Lymnaea truncatula by Fasciola hepatica were experimentally carried out to identify the redial generations of this trematode when the larval development was unusual (when the first-appearing mother redia, or R1a redia, died after its exit from the sporocyst). Four parameters were measured in the body and pharyngeal region at weekly intervals. At day 49 post-exposure at 20°C, the body of the second mother rediae (R1b) was significantly longer than that of the subsequent generations, R2a and R2b/R3a (a mean of 3.0 mm instead of 1.0 and 0.9 mm, respectively). The body was significantly wider in the R1b and R2a groups than in the R2b/R3a rediae. The pharyngeal lumen was significantly wider in the R1b group than in the R2a and R2b/R3a rediae (a mean of 48.6 μm instead of 10.8 and 3.3 μm at day 49). The thickness of the pharyngeal wall did not differ in the R1b and R2b/R3a groups, but was significantly lower in the R2a group (19.5 μm instead of 23.0–23.6 at day 49). There was better development of R1b and R2b/R3a rediae in the snails when the R1a redia died, compared with normal larval development (with a living R1a redia).

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Stegou-Sagia, A. "On blends R32/R134a and R32/R125: thermodynamic and heat transfer aspects." Fuel and Energy Abstracts 43, no. 4 (July 2002): 285. http://dx.doi.org/10.1016/s0140-6701(02)86483-9.

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Stegou-Sagia, A. "On blends R32/R134a and R32/R125: Thermodynamic and heat transfer aspects." International Journal of Energy Research 25, no. 9 (2001): 793–802. http://dx.doi.org/10.1002/er.722.

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Norman, David J., Qi Huang, Jeanne M. F. Yuen, Arianna Mangravita-Novo, and Drew Byrne. "Susceptibility of Geranium Cultivars to Ralstonia solanacearum." HortScience 44, no. 5 (August 2009): 1504–8. http://dx.doi.org/10.21273/hortsci.44.5.1504.

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Sixty-one cultivars of geraniums, including zonal, regal, ivy, and scented, were tested for susceptibility to three strains of Ralstonia solanacearum: a race 1, biovar 1 (R1B1) strain P597 isolated from tomato in Florida, a R1B1 strain P673 obtained from pothos originated from Costa Rica, and a race 3, biovar 2 (R3B2) strain UW551 isolated from geranium imported from Kenya. These three strains represent populations of R. solanacearum found in the United States or imported with infected plant propagative material. A genomic comparison of the geranium cultivars was also done using amplified fragment length polymorphisms. Both R1B1 strains were more virulent than the R3B2 strain, producing wilt symptoms on most cultivars of zonal, regal, and ivy types. Variation in susceptibility of geranium cultivars to the two R1B1 strains was observed. The R3B2 strain UW551 had a much more restricted host range and was not able to infect most regal geranium cultivars when applied as a soil drench. Many of the scented cultivars were found to be resistant to all three strains of R. solanacearum when tested using the drench inoculation method. However, most scented cultivars were found to be susceptible when plants were wound-inoculated. The greatest variation in type of resistance was observed between the scented geranium cultivars and specific strains of R. solanacearum.

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Bigey, F., B. Grossiord, C. K. N. Chan Kwo Chion, A. Arnaud, and P. Galzy. "Brevibacterium linens pBL33 and Rhodococcus rhodochrous pRC1 cryptic plasmids replicate in Rhodococcus sp. R312 (formerly Brevibacterium sp. R312)." Gene 154, no. 1 (February 1995): 77–79. http://dx.doi.org/10.1016/0378-1119(94)00886-w.

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Tsvetkov, O. B., Yu A. Laptev, S. V. Rykov, N. A. Galakhova, and N. G. Ismagilov. "On the thermal conductivity of R32 in critical region." Journal International Academy of Refrigeration 15, no. 4 (2016): 80–84. http://dx.doi.org/10.21047/1606-4313-2016-15-4-80-84.

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Cha, Sang Won, Ho Saeng Lee, Deok Soo Moon, and Hyeon Ju Kim. "Basic performance analysis of ocean thermal energy conversion using the refrigerant mixture R32/R152a." Journal of the Korean Society of Marine Engineering 38, no. 4 (May 31, 2014): 502–7. http://dx.doi.org/10.5916/jkosme.2014.38.4.502.

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Augot, D., D. Rondelaud, G. Dreyfuss, J. Cabaret, C. Bayssade-Dufour, and J. L. Albaret. "Characterization of Fasciola hepatica redial generations by morphometry and chaetotaxy under experimental conditions." Journal of Helminthology 72, no. 3 (September 1998): 193–98. http://dx.doi.org/10.1017/s0022149x00016436.

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AbstractMorphometric and chaetotactic studies were carried out on the body and cephalic regions of the rediae of Fasciola hepatica (Trematoda: Fasciolidae) in order to precisely identify the different redial generations of this trematode in Lymnaea truncatula under experimental infection. At day 49 post-exposure at 20°C, the length of the redia was significantly higher in the first group of the first generation (R1a) compared with successive generations, R1b, R2a and R2b/R3a. The width of the body was similar in the R1a, R1b, and R2a rediae, but was significantly lower in the R2b/R3a groups. The intrapharyngeal cavity of R1a rediae was significantly wider compared with the R1b, R2a, and R2b/R3a groups, whereas the pharyngeal wall was significantly thicker in the R2b/R3a rediae compared with the R1b and R2a groups. Four other measurements, namely the maximum length and width of the pharynx, diameter of the mouth, and width of intestine, also showed significant variations in relation to pharyngeal morphology and age of infection. Discriminant analysis based on these measurements demonstrated that 98% of the rediae were readily categorized into the four groups identified. The number of perioral sensillae ranged from 126 to 160 but a significant difference was only noted between the mean values of the first generation and those of the group R2b/R3a. From these parameters, the maximum width of the pharyngeal lumen was found to be the best characteristic in the identification of the redial generations.

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Sivaraman, Vijay, Liguo Zhang, Eric G. Meissner, Jerry L. Jeffrey, and Lishan Su. "The Heptad Repeat 2 Domain Is a Major Determinant for Enhanced Human Immunodeficiency Virus Type 1 (HIV-1) Fusion and Pathogenicity of a Highly Pathogenic HIV-1 Env." Journal of Virology 83, no. 22 (September 2, 2009): 11715–25. http://dx.doi.org/10.1128/jvi.00649-09.

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ABSTRACT Human immunodeficiency virus type 1 (HIV-1)-mediated depletion of CD4+ lymphocytes in an infected individual is the hallmark of progression to AIDS. However, the mechanism for this depletion remains unclear. To identify mechanisms of HIV-1-mediated CD4 T-cell death, two similar viral isolates obtained from a rapid progressor patient with significantly different pathogenic phenotypes were studied. One isolate (R3A) demonstrates enhanced pathogenesis in both in vivo models and relevant ex vivo lymphoid organ model systems compared to another isolate, R3B. The pathogenic determinants were previously mapped to the V5-gp41 envelope region, correlating functionally with enhanced fusion activity and elevated CXCR4 binding affinity. To further elucidate specific differences between R3A and R3B within the V5-gp41 domains that enhance CD4 depletion, R3A-R3B chimeras to study the V5-gp41 region were developed. Our data demonstrate that six residues in the ectodomain of R3A provide the major determinant for both enhanced Env-cell fusion and pathogenicity. Furthermore, three amino acid differences in the heptad repeat 2 (HR-2) domain of R3A determined its fusion activity and significantly elevated its pathogenic activity. The chimeric viruses with enhanced fusion activity, but not elevated CXCR4 affinity, correlated with high pathogenicity in the thymus organ. We conclude that the functional domain of a highly pathogenic HIV-1 Env is determined by mutations in the HR-2 region that contribute to enhanced fusion and CD4 T-cell depletion.

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Mezentseva, N. N., and I. V. Mezentsev. "Investigation of Heat Pump Efficiency on Zeotropic Refrigerants R32/R134a and R32/R152a." Journal of Engineering Thermophysics 27, no. 4 (October 2018): 554–59. http://dx.doi.org/10.1134/s1810232818040185.

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Di Nicola, Giovanni, Giuliano Giuliani, Fabio Polonara, and Roman Stryjek. "Solid–liquid equilibria for the CO2+N2O, CO2+R32, and N2O+R32 systems." Fluid Phase Equilibria 256, no. 1-2 (August 2007): 86–92. http://dx.doi.org/10.1016/j.fluid.2006.11.015.

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Li, Guangcun, Sanwen Huang, Xiao Guo, Ying Li, Yu Yang, Zhen Guo, Hanhui Kuang, et al. "Cloning and Characterization of R3b; Members of the R3 Superfamily of Late Blight Resistance Genes Show Sequence and Functional Divergence." Molecular Plant-Microbe Interactions® 24, no. 10 (October 2011): 1132–42. http://dx.doi.org/10.1094/mpmi-11-10-0276.

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Massive resistance (R) gene stacking is considered to be one of the most promising approaches to provide durable resistance to potato late blight for both conventional and genetically modified breeding strategies. The R3 complex locus on chromosome XI in potato is an example of natural R gene stacking, because it contains two closely linked R genes (R3a and R3b) with distinct resistance specificities to Phytophthora infestans. Here, we report about the positional cloning of R3b. Both transient and stable transformations of susceptible tobacco and potato plants showed that R3b conferred full resistance to incompatible P. infestans isolates. R3b encodes a coiled-coil nucleotide-binding site leucine-rich repeat protein and exhibits 82% nucleotide identity with R3a located in the same R3 cluster. The R3b gene specifically recognizes Avr3b, a newly identified avirulence factor from P. infestans. R3b does not recognize Avr3a, the corresponding avirulence gene for R3a, showing that, despite their high sequence similarity, R3b and R3a have clearly distinct recognition specificities. In addition to the Rpi-mcd1/Rpi-blb3 locus on chromosome IV, the R3 locus on chromosome XI is the second example of an R-gene cluster with multiple genes recognizing different races of P. infestans.

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Schellhorn, Martin. "Einfache Lösungen für normgerechtes Risikomanagement." HLH 71, no. 02 (2020): 50–53. http://dx.doi.org/10.37544/1436-5103-2020-02-50.

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Die Kälte- und Klimabranche befindet sich im Umbruch. Entscheider und Investoren müssen sich Gedanken um das Phase-Down-Szenario machen und sich auf den Einsatz neuer Kältemittel einstellen. Das Kältemittel R32 bietet im Hinblick auf die Reduzierung der Kältemittelmengen und die Diskussion über neue Kältemittel eine sichere und praktikable Lösung. Der Fachbeitrag klärt über die wichtigsten Aspekte der normenkonformen Installation von Klimaanlagen und Kaltwassersätzen mit dem Kältemittel R32 auf.

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Bos, Jorunn I. B., Angela Chaparro-Garcia, Lina M. Quesada-Ocampo, Brian B. McSpadden Gardener, and Sophien Kamoun. "Distinct Amino Acids of the Phytophthora infestans Effector AVR3a Condition Activation of R3a Hypersensitivity and Suppression of Cell Death." Molecular Plant-Microbe Interactions® 22, no. 3 (March 2009): 269–81. http://dx.doi.org/10.1094/mpmi-22-3-0269.

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The AVR3a protein of Phytophthora infestans is a polymorphic member of the RXLR class of cytoplasmic effectors with dual functions. AVR3aKI but not AVR3aEM activates innate immunity triggered by the potato resistance protein R3a and is a strong suppressor of the cell-death response induced by INF1 elicitin, a secreted P. infestans protein that has features of pathogen-associated molecular patterns. To gain insights into the molecular basis of AVR3a activities, we performed structure-function analyses of both AVR3a forms. We utilized saturated high-throughput mutant screens to identify amino acids important for R3a activation. Of 6,500 AVR3aEM clones tested, we identified 136 AVR3aEM mutant clones that gained the ability to induce R3a hypersensitivity. Fifteen amino-acid sites were affected in this set of mutant clones. Most of these mutants did not suppress cell death at a level similar to that of AVR3aKI. A similar loss-of-function screen of 4,500 AVR3aKI clones identified only 13 mutants with altered activity. These results point to models in which AVR3a functions by interacting with one or more host proteins and are not consistent with the recognition of AVR3a through an enzymatic activity. The identification of mutants that gain R3a activation but not cell-death suppression activity suggests that distinct amino acids condition the two AVR3a effector activities.

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Moeini, Vahid, and Mahin Farzad. "Calculation of Thermal Pressure Coefficient of R11, R13, R14, R22, R23, R32, R41, and R113 Refrigerants by pVT Data." Advances in Physical Chemistry 2013 (May 28, 2013): 1–8. http://dx.doi.org/10.1155/2013/327419.

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For thermodynamic performance to be optimized particular attention must be paid to the fluid’s thermal pressure coefficients and thermodynamic properties. A new analytical expression based on the statistical mechanics is derived for R11, R13, R14, R22, R23, R32, R41, and R113 refrigerants, using the intermolecular forces theory. In this paper, temperature dependency of the parameters of R11, R13, R14, R22, R23, R32, R41, and R113 refrigerants to calculate thermal pressure coefficients in the form of first order has been developed to second and third orders and their temperature derivatives of new parameters are used to calculate thermal pressure coefficients. These problems have led us to try to establish a function for the accurate calculation of the thermal pressure coefficients of R11, R13, R14, R22, R23, R32, R41, and R113 refrigerants based on statistical-mechanics theory for different refrigerants.

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Yang, Xiaohui, Xiao Guo, Guangxia Chen, Daofeng Dong, Fang Liu, Yuanjun Yang, Yu Yang, and Guangcun Li. "Comparison of defense responses of transgenic potato lines expressing three different Rpi genes to specific Phytophthora infestans races based on transcriptome profiling." PeerJ 8 (May 5, 2020): e9096. http://dx.doi.org/10.7717/peerj.9096.

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Potato late blight, one of the most devastating diseases in potato, is caused by the oomycete Phytophthora infestans. Over 20 resistance genes have been cloned including R1, R3a, and R3b. The distinctions between defense response mechanisms mediated by different resistance genes are still unclear. Here we performed transcriptome profiling in three transgenic lines, R1, R3a, and R3b, and wild-type Desiree under inoculation with two P. infestans isolates, 89148 (race 0) and CN152 (super race), using RNA-seq. Compared with wild type, specific differentially expressed genes (DEGs) were identified in the three transgenic lines. The highest number of DEGs occurred in transgenic R3b, with 779 DEGs in response to isolate 89148 and 864 DEGs in response to infection by CN152, followed by transgenic R1 lines with 408 DEGs for isolate 89148 and 267 DEGs for CN152. Based on gene ontology, the most common GO terms (15 for 89148 and 20 for CN152) were enriched in transgenic R3a and R3b lines. This indicates that the defense pathways mediated by R3a and R3b are more similar than those mediated by R1. Further separate GO analysis of up- or down-regulated DEGs showed that the down-regulated DEGs mainly functioned in mediating the resistance of potato to P. infestans 89148 by response to stress biological process and to CN152 by oxidation reduction biological process. KEGG pathways of DNA replication, plant-pathogen interaction and pentose and glucuronate interconversions are unique for transgenic R1, R3a, and R3b lines in incompatible interactions. Quantitative real-time PCR experimental validation confirmed the induced expression of DEGs in the late blight resistance signaling pathway. Our results will lay a solid foundation for further understanding the mechanisms of plant-pathogen interactions, and provide a theoretical reference for durable resistance in potato.

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Duran, R., C. K. N. Chan Kwo Chion, A. Arnaud, and P. Galzy. "Isolation of promoter sequences from Brevibacterium sp. R312." Zentralblatt für Mikrobiologie 147, no. 8 (November 1992): 499–502. http://dx.doi.org/10.1016/s0232-4393(11)80378-1.

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30

Nagasawa, Toru, Koichiro Ryuno, and Hideaki Yamada. "Nitrile hydratase of Brevibacterium R312 — purification and characterization —." Biochemical and Biophysical Research Communications 139, no. 3 (September 1986): 1305–12. http://dx.doi.org/10.1016/s0006-291x(86)80320-5.

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31

Guéneron, J. P., I. Nègre, N. Gombault, and K. Samii. "R362 Retentissement des accidents d'anesthesie sur les anesthesistes." Annales Françaises d'Anesthésie et de Réanimation 17, no. 8 (January 1998): 992. http://dx.doi.org/10.1016/s0750-7658(98)80479-6.

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Lambrechts, Christel, J. Escudero, and P. Galzy. "Purification and properties of three esterases fromBrevibacteriumsp. R312." Journal of Applied Bacteriology 78, no. 2 (February 1995): 180–88. http://dx.doi.org/10.1111/j.1365-2672.1995.tb02840.x.

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33

Ramazanov, I. R., A. V. Yaroslavova, U. M. Dzhemilev, and O. M. Nefedov. "Cyclopropanation of alkynols with the CH2I2-R3Al system." Russian Chemical Bulletin 60, no. 2 (February 2011): 313–18. http://dx.doi.org/10.1007/s11172-011-0051-9.

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Xue, Dongqi, Han Liu, Dong Wang, Yanna Gao, and Zhiqi Jia. "Comparative transcriptome analysis of R3a and Avr3a-mediated defense responses in transgenic tomato." PeerJ 9 (August 9, 2021): e11965. http://dx.doi.org/10.7717/peerj.11965.

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Late blight caused by Phytophthora infestans is one of the most devastating diseases in potatoes and tomatoes. At present, several late blight resistance genes have been mapped and cloned. To better understand the transcriptome changes during the incompatible interaction process between R3a and Avr3a, in this study, after spraying DEX, the leaves of MM-R3a-Avr3a and MM-Avr3a transgenic plants at different time points were used for comparative transcriptome analysis. A total of 7,324 repeated DEGs were detected in MM-R3a-Avr3a plants at 2-h and 6-h, and 729 genes were differentially expressed at 6-h compared with 2-h. Only 1,319 repeated DEGs were found in MM-Avr3a at 2-h and 6-h, of which 330 genes have the same expression pattern. Based on GO, KEGG and WCGNA analysis of DEGs, the phenylpropanoid biosynthesis, plant-pathogen interaction, and plant hormone signal transduction pathways were significantly up-regulated. Parts of the down-regulated DEGs were enriched in carbon metabolism and the photosynthesis process. Among these DEGs, most of the transcription factors, such as WRKY, MYB, and NAC, related to disease resistance or endogenous hormones SA and ET pathways, as well as PR, CML, SGT1 gene were also significantly induced. Our results provide transcriptome-wide insights into R3a and Avr3a-mediated incompatibility interaction.

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Kiselev, S. B., and M. L. Huber. "Thermodynamic properties of R32 + R134a and R125 + R32 mixtures in and beyond the critical region." International Journal of Refrigeration 21, no. 1 (January 1998): 64–76. http://dx.doi.org/10.1016/s0140-7007(97)00069-8.

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Meissner, Eric G., Liguo Zhang, S. Jiang, and Lishan Su. "Fusion-Induced Apoptosis Contributes to Thymocyte Depletion by a Pathogenic Human Immunodeficiency Virus Type 1 Envelope in the Human Thymus." Journal of Virology 80, no. 22 (November 1, 2006): 11019–30. http://dx.doi.org/10.1128/jvi.01382-06.

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ABSTRACT The mechanisms of CD4+ T-cell depletion during human immunodeficiency virus type 1 (HIV-1) infection remain incompletely characterized. Of particular importance is how CD4+ T cells are depleted within the lymphoid organs, including the lymph nodes and thymus. Herein we characterize the pathogenic mechanisms of an envelope from a rapid progressor (R3A Env) in the NL4-3 backbone (NL4-R3A) which is able to efficiently replicate and deplete CD4+ thymocytes in the human fetal-thymus organ culture (HF-TOC). We demonstrate that uninterrupted replication is required for continual thymocyte depletion. During depletion, NL4-R3A induces an increase in thymocytes which uptake 7AAD, a marker of cell death, and which express active caspase-3, a marker of apoptosis. While 7AAD uptake is observed predominantly in uninfected thymocytes (p24−), active caspase-3 is expressed in both infected (p24+) and uninfected thymocytes (p24−). When added to HF-TOC with ongoing infection, the protease inhibitor saquinavir efficiently suppresses NL4-R3A replication. In contrast, the fusion inhibitors T20 and C34 allow for sustained HIV-1 production. Interestingly, T20 and C34 effectively prevent thymocyte depletion in spite of this sustained replication. Apoptosis of both p24− and p24+ thymocytes appears to be envelope fusion dependent, as T20, but not saquinavir, is capable of reducing thymocyte apoptosis. Together, our data support a model whereby pathogenic envelope-dependent fusion contributes to thymocyte depletion in HIV-1-infected thymus, correlated with induction of apoptosis in both p24+ and p24− thymocytes.

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Park, Yun Ki, and Man Yeoung Ha. "An Experimental Study on the Performance Improvement of an R32 Inverter Heat Pump System." Korean Journal of Air-Conditioning and Refrigeration Engineering 26, no. 11 (November 10, 2014): 547–52. http://dx.doi.org/10.6110/kjacr.2014.26.11.547.

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38

Gabriel, Dean W., Caitilyn Allen, Mark Schell, Timothy P. Denny, Jean T. Greenberg, Yong Ping Duan, Zomary Flores-Cruz, et al. "Identification of Open Reading Frames Unique to a Select Agent: Ralstonia solanacearum Race 3 Biovar 2." Molecular Plant-Microbe Interactions® 19, no. 1 (January 2006): 69–79. http://dx.doi.org/10.1094/mpmi-19-0069.

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An 8× draft genome was obtained and annotated for Ralstonia solanacearum race 3 biovar 2 (R3B2) strain UW551, a United States Department of Agriculture Select Agent isolated from geranium. The draft UW551 genome consisted of 80,169 reads resulting in 582 contigs containing 5,925,491 base pairs, with an average 64.5% GC content. Annotation revealed a predicted 4,454 protein coding open reading frames (ORFs), 43 tRNAs, and 5 rRNAs; 2,793 (or 62%) of the ORFs had a functional assignment. The UW551 genome was compared with the published genome of R. solanacearum race 1 biovar 3 tropical tomato strain GMI1000. The two phylogenetically distinct strains were at least 71% syntenic in gene organization. Most genes encoding known pathogenicity determinants, including predicted type III secreted effectors, appeared to be common to both strains. A total of 402 unique UW551 ORFs were identified, none of which had a best hit or >45% amino acid sequence identity with any R. solanacearum predicted protein; 16 had strong (E < 10-13) best hits to ORFs found in other bacterial plant pathogens. Many of the 402 unique genes were clustered, including 5 found in the hrp region and 38 contiguous, potential prophage genes. Conservation of some UW551 unique genes among R3B2 strains was examined by polymerase chain reaction among a group of 58 strains from different races and biovars, resulting in the identification of genes that may be potentially useful for diagnostic detection and identification of R3B2 strains. One 22-kb region that appears to be present in GMI1000 as a result of horizontal gene transfer is absent from UW551 and encodes enzymes that likely are essential for utilization of the three sugar alcohols that distinguish biovars 3 and 4 from biovars 1 and 2.

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39

Morales, Patricia, Line Garneau, Hélène Klein, Marie-France Lavoie, Lucie Parent, and Rémy Sauvé. "Contribution of the KCa3.1 channel–calmodulin interactions to the regulation of the KCa3.1 gating process." Journal of General Physiology 142, no. 1 (June 24, 2013): 37–60. http://dx.doi.org/10.1085/jgp.201210933.

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The Ca2+-activated potassium channel of intermediate conductance, KCa3.1, is now emerging as a therapeutic target for a large variety of health disorders. The Ca2+ sensitivity of KCa3.1 is conferred by the Ca2+-binding protein calmodulin (CaM), with the CaM C-lobe constitutively bound to an intracellular domain of the channel C terminus. It was proposed on the basis of the crystal structure obtained for the C-terminal region of the rat KCa2.2 channel (rSK2) with CaM that the binding of Ca2+ to the CaM N-lobe results in CaM interlocking the C-terminal regions of two adjacent KCa3.1 subunits, leading to the formation of a dimeric structure. A study was thus undertaken to identify residues of the CaM N-lobe–KCa3.1 complex that either contribute to the channel activation process or control the channel open probability at saturating Ca2+ (Pomax). A structural homology model of the KCa3.1–CaM complex was first generated using as template the crystal structure of the C-terminal region of the rat KCa2.2 channel with CaM. This model was confirmed by cross-bridging residues R362 of KCa3.1 and K75 of CaM. Patch-clamp experiments were next performed, demonstrating that the solvation energy of the residue at position 367 in KCa3.1 is a key determinant to the channel Pomax and deactivation time toff. Mutations of residues M368 and Q364 predicted to form anchoring points for CaM binding to KCa3.1 had little impact on either toff or Pomax. Finally, our results show that channel activation depends on electrostatic interactions involving the charged residues R362 and E363, added to a nonpolar energy contribution coming from M368. We conclude that electrostatic interactions involving residues R362 and E363 and hydrophobic effects at M368 play a prominent role in KCa3.1 activation, whereas hydrophobic interactions at S367 are determinant to the stability of the CaM–KCa3.1 complex throughout gating.

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40

Болдырев, К. Н., Н. Н. Кузьмин, and Е. А. Добрецова. "Структурные особенности твердых растворов Nd-=SUB=-x-=/SUB=-Gd-=SUB=-1-x-=/SUB=-Cr-=SUB=-3-=/SUB=-(BO-=SUB=-3-=/SUB=-)-=SUB=-4-=/SUB=-." Оптика и спектроскопия 129, no. 1 (2021): 41. http://dx.doi.org/10.21883/os.2021.01.50437.248-20.

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Optical studies of NdxGd1-xCr3(BO3)4 0.01≤x≤1 crystals have been carried out. A significant concentration effect of the Nd3+ ion on the crystal structure of these solid solutions was identified. It was found from the absorption spectra of neodymium ions in the 4I9/2→11F3/2 transition region that at a concentration x>0.6 two nonequivalent Nd3+ centers appear, which is explained by the formation of two polytype modifications with space groups R32 and C2/c. At a concentration x<0.6, only one modification with the space group R32 is observed.

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41

Técoult, E., and P. Feiss. "R372 Evaluation des connaissances des medecins generalistes en anesthesiereanimation." Annales Françaises d'Anesthésie et de Réanimation 17, no. 8 (January 1998): 997. http://dx.doi.org/10.1016/s0750-7658(98)80489-9.

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42

Hyakutake, Y. "Toward the Determination of R3F2 Terms in M-Theory." Progress of Theoretical Physics 118, no. 1 (July 1, 2007): 109–19. http://dx.doi.org/10.1143/ptp.118.109.

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43

Stevens, Julie M., Maya Belghazi, Maryse Jaouen, Didier Bonnet, Jean-Marie Schmitter, Daniel Mansuy, Marie-Agn�s Sari, and Isabelle Artaud. "Post-translational modification ofRhodococcus R312 andComamonas NI1 nitrile hydratases." Journal of Mass Spectrometry 38, no. 9 (2003): 955–61. http://dx.doi.org/10.1002/jms.509.

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44

Nhut, Le Minh, and Tran Quang Danh. "An experimental investigation on the coefficient of performance of the small hot water heat pump using refrigeration R410A and R32." Science & Technology Development Journal - Engineering and Technology 3, no. 2 (September 6, 2020): First. http://dx.doi.org/10.32508/stdjet.v3i2.676.

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Hot water is an important factor in domestic life and industrial development. Today, the heat pump is used to produce hot water more and more popular because it has many advantages of saving energy compared to the method of producing hot water by the hot water electric heater. The main aim of this study is to evaluate of the coefficient of performance (COP) of the small hot water heat pump using refrigeration R410A and R32. The capacity of both hot water heat pump is similar, one using new refrigerant R32 and other using refrigerant R410A. These heat pumps were designed and installed at the Ho Chi Minh City University of Technology and Education to evaluate the COP for the purpose of application the new refrigerant R32 for hot water heat pump. The compressor capacity is 1 Hp, the volume of hot water storage tank is of 100 liters and is insulated with thickness of 30 mm to reduce the heat loss to invironment, the required hot water temperature at the outlet of condenser is 50 oC, and the amount of required hot water is 75 liters per batch and is controlled by float valve. The experimental results indicate that the COP of the heat pump using the new refrigerant R32 is higher than heat pump using refrigerant R410A from 9% to 15% when the experimental conditions such as ambient temperature, initial water flow rate through the condenser and the required temperature of hot water were the same. In addition, the effect of the ambient temperature, initial water temperature and water flow rate were also evaluated.

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45

Zhang, Cheng, Kangjie Deng, Dewen Yuan, Wenxing Liu, and Xiao Yan. "Nanofilm boiling and evaporation of working fluids R32/R1234ze(E) on metal walls: Insights from molecular dynamics simulations." International Journal of Modern Physics B 35, no. 13 (May 20, 2021): 2150165. http://dx.doi.org/10.1142/s0217979221501654.

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Understanding energy transfer between working fluid and vapor is a critical issue in absorption refrigeration and thermophysics for the aim of intensifying heat conversion. However, it is difficult to achieve by experimental measurements due to the difficulty in catching the detailed and accurate modeling information, e.g., specific working fluid, and its underlying molecular mechanism. In order to study the evaporation and boiling behavior of refrigerant mixture from the microscopic point of view, the nanofilm consisting of different working fluids, with the evaporation model of R32/R1234ze (E) on metal wall, was established by utilizing molecular dynamics (MD) method. The effect of different mole ratios, i.e., pure R32, 3:1, 1:1, 1:3, pure R1234ze (E), on the evaporation and boiling behavior of mixtures was analyzed. The results show that the probability of explosive boiling decreases with the decrease of R32 molecular mole ratios. Thus, in turn, the performance of refrigerant mixture is observed to be better than that of pure refrigerant. Insights from this simulation research could provide an effective reference for the MD interactions and have potential benefit in developing efficient and sustainable processes for industries to minimize the chemical usage and environmental damage.

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46

Ardita, I. Nengah, I. Gusti Agung Bagus Wirajati, I. Dewa Made Susila, and Sudirman Sudirman. "Performance analysis of retrofit R410a refrigerant with R32 refrigerant on a split air conditioner." Journal of Applied Mechanical Engineering and Green Technology 2, no. 1 (March 31, 2021): 1–4. http://dx.doi.org/10.31940/jametech.v2i1.2459.

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Split air conditioning (AC) is the most widely used in the community for both commercial and domestic utilities. At the present refrigerant which used in Split AC is mostly common group of HFCs, such as R410a. R410a is a zeotropic refrigerant and if there is a leak in the system, it cannot be added this refrigerant. This will increase the cost of maintenance. The aims of this research is to investigate the retrofit of R410a with R32 on the Split AC system. The R32 is chosen because it has higher latent evaporation heat at the same temperature and has less effect on global warming. The refrigeration effect, the power consumption and the system performance are the main three quantities that want to be examined in this research which are observed before and after retrofit. Experimental investigation conducted during this research, including design and manufacture of experimental equipment, calibration and tools installment, collecting the experimental data and analysis by quantitative description method before and after retrofit. The results informed that cooling effect increased during the research, but the COP system has a slight decrease about 4%. R32 refrigerant is quite feasible as a retrofit refrigerant to R410a refrigerant.

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47

Winder, W. W., M. L. Terry, and V. M. Mitchell. "Role of plasma epinephrine in fasted exercising rats." American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 248, no. 3 (March 1, 1985): R302—R307. http://dx.doi.org/10.1152/ajpregu.1985.248.3.r302.

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We have investigated the physiological role of the marked increase in plasma epinephrine that occurs in fasted exercising rats. Fasted adrenodemedullated (ADM) rats show a marked reduction in endurance run times compared with sham-operated (SO) controls. After running for 30 min at 21 m/min up a 10% grade, ADM rats' blood glucose was 2.9 +/- 0.1 mM vs. 4.3 +/- 0.2 mM in SO rats. At the same time, blood lactate was 3.0 +/- 0.2 mM in SO rats compared with 1.0 +/- 0.1 mM in ADM rats. Glycogenolysis was impaired in ADM rats in the fast-twitch white region of the quadriceps, lateral gastrocnemius, and soleus muscles but not in the fast-twitch red region of the quadriceps muscle. Hepatic adenosine 3',-5'-cyclic monophosphate was increased to the same extent in ADM and SO rats during exercise. Infusion of epinephrine into ADM rats during exercise corrected the hypoglycemia, restored lactate to normal, and stimulated glycogenolysis in soleus, white quadriceps, and lateral gastrocnemius muscles. Epinephrine-dependent glycogenolysis in contracting type I and noncontracting type II muscle fibers apparently provides essential quantities of lactate for hepatic gluconeogenesis in fasted exercising rats.

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48

Zolman, J. C. "Dynamic model of gonadotropin-releasing hormone receptor function." American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 248, no. 3 (March 1, 1985): R312—R319. http://dx.doi.org/10.1152/ajpregu.1985.248.3.r312.

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Functioning gonadotropin-releasing hormone (GnRH) receptor is visualized as an aggregate of identical subunits (not all always functional) with the aggregate usually transformed into at least four successive structurally distinct receptor assemblies. Receptor protein, hormone molecule(s), and carrier(s) are main components of each functional subunit. During the normal lifespan of the functional subunit, each carrier is responsible for delivery of a unit amount of product, per unit time, to the cell surface (ratio between functional carrier and bound hormone, 1:1). Association of hormone with the receptor protein is essential, not only for the initial formation of the functional subunits but also for subsequent conformational changes that are in turn essential for formation of the aggregate only, or later (in the presence of sufficiently high GnRH concentrations) for a successive formation of a family of receptor assemblies (occurring one at a time). The successive assemblies differ from the aggregate by being more stable and from one another by increasing GnRH binding affinity and apparent capacity. They resist stimulation during protracted decay (desensitization).

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49

Lutz, P. L., R. Edwards, and P. M. McMahon. "gamma-Aminobutyric acid concentrations are maintained in anoxic turtle brain." American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 249, no. 3 (September 1, 1985): R372—R374. http://dx.doi.org/10.1152/ajpregu.1985.249.3.r372.

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Changes in gamma-aminobutyric acid (GABA) concentrations in the turtle (Pseudemys scripta elegans) brain were studied in situ during prolonged anoxia. With the onset of anoxia, the well-documented rapid increases in GABA found in mammalian brains were not observed in the turtle brain. Although not statistically significant, mean GABA concentrations in the turtle brain were reduced from anesthetized control values during the first 30 min of anoxia. During this initial period brain glutamate content declined. Even after 2 h of nitrogen respiration, GABA in the turtle brain still did not rise above control levels. By the 4th h of anoxia, however, GABA had increased to 147% of control values.

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50

van Waeg, G., T. Groth, F. Niklasson, and C. H. de Verdier. "Allopurinol kinetics in humans as a means to assess liver function: comparison of different models." American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 253, no. 2 (August 1, 1987): R352—R360. http://dx.doi.org/10.1152/ajpregu.1987.253.2.r352.

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To describe the mechanisms involved in allopurinol kinetics after intravenous injection in humans, a number of alternative computer-based biodynamic models were designed. Distribution processes were described with two-compartment as well as with three-compartment kinetics for both allopurinol and its metabolite oxipurinol. These two major physiological alternatives were combined with biochemical models assuming either competitive or tight-binding-complex inhibition kinetics. The four resulting basic models were evaluated (and successively improved) using sets of plasma allopurinol and oxipurinol concentration curves, measured after intravenous injection in healthy subjects and in patients with different degrees of liver function. A three-compartment model with tight-binding-complex inhibition was selected and used to analyze the 35 loading tests performed. One of the parameters estimated in this way, the fractional rate constant for transport of allopurinol from the central compartment to the metabolically active (liver) compartment (kA31), turned out to be a powerful discriminative parameter between a group of healthy subjects, a group of patients with slightly to moderately reduced overall liver function, and a group with severely reduced overall liver function [kA31(min-1) = 0.136 +/- 0.042 (mean +/- SD, n = 13), 0.072 +/- 0.024 (n = 13), and 0.025 +/- 0.015 (n = 8), respectively].

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Journal articles on the topic 'R3A2'

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