94 research outputs found

    On Group Structures of Some Special Elliptic Curves

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    The purpose of this paper is to determine the structures of groups of rational points on elliptic curves of form y2 = x3 − px where p is a Fermat or Mersenne prime. Let E be an elliptic curve y2 = x3 − px where p is a prime and let Γ be the set of rational points in E. Then Γ has an abelian group structure. Mordell-Weil theorem states that Γ is finitely generated. Thus we can set Γ = F ⊕ T where F and T are the free part and the torsion part of Γ, respectively. Let β be a natural group homomorphism from Q × to Q × = Q×/Q×2 and let α be the group homomorphism from Γ to Q × defined by α(P) = 1 for P = Oβ(−p) for P = 0 β(x) for x 6 = 0 where P = (x, y) ∈ Γ, 0 = (0, 0) is the origin and O is the point at infinity. We consider an elliptic curve E ̄ : y2 = x3 + 4px corresponding to E and we similarly define α ̄ from Γ ̄ to Q×, namely, ᾱ(P) = 1 for P = Oβ(p) for P = 0 β(x) for x 6 = 0 where P = (x, y) ∈ Γ̄. The rank r of the free part F of Γ is computed from the formul

    Transamination of L-cysteine sulfinate in the growing rat.

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    The enzyme activities involved in the transamination of L-cysteine sulfinate (L-alanine 3-sulfinic acid), L-aspartate and L-cysteine were examined in fetal, neonatal and maternal rat liver and placenta. In fetal and neonatal rat liver, aminotransferase activity was most active with L-cysteine sulfinate as a substrate and was also active with L-aspartate, while activity with L-cysteine was very low. The activity of transamination of L-cysteine sulfinate in rat liver developed in parallel with that of L-aspartate and L-cysteine. The aminotransferase activity markedly increased after the 19th day of gestation, reaching the same value as adult liver on the 3rd day after birth. The ratios of transamination of L-cysteine sulfinate to that of L-aspartate and to that of L-cysteine were constant during development. These observations suggest that L-cysteine sulfinate, L-aspartate and L-cysteine are transaminated by the same enzyme in the rat liver during development. Since placental aminotransferase activity was extremely low compared with that of the liver, it was suggested that the placenta did not play an important role in the transamination of these amino acids during pregnancy.</p

    Alleviating New User Cold-Start in User-Based Collaborative Filtering via Bipartite Network

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    The recommender system (RS) can help us extract valuable data from a huge amount of raw information. User-based collaborative filtering (UBCF) is widely employed in practical RSs due to its outstanding performance. However, the traditional UBCF is subject to the new user cold-start issue because a new user is often extreme lack of available rating information. In this article, we develop a novel approach that incorporates a bipartite network into UBCF for enhancing the recommendation quality of new users. First, through the statistic and analysis of new users\u27 rating characteristics, we collect niche items and map the corresponding rating matrix to a weighted bipartite network. Furthermore, a new weighted bipartite modularity index merging normalized rating information is present to conduct the community partition that realizes coclustering of users and items. Finally, for each individual clustering that is much smaller than the original rating matrix, a localized low-rank matrix factorization is executed to predict rating scores for unrated items. Items with the highest predicted rating scores are recommended to a new user. Experimental results from two real-world data sets suggest that without requiring additional complex information, the proposed approach is superior in terms of both recommendation accuracy and diversity and can alleviate the new user cold-start issue of UBCF effectively

    Effect of taurine concentration on platelet aggregation in gestosis patients with edema, proteinuria and hypertension.

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    To elucidate the relationship between the high concentration of taurine in platelets and platelet aggregation in patients with EPH gestosis (gestosis with edema, proteinuria and hypertension), platelet aggregation and the platelet release response (release of ATP and beta-thromboglobulin) were studied in the washed platelet suspension (PS) obtained from normal pregnant or non-pregnant women and EPH gestosis patients. Platelet aggregation and platelet release response were significantly lower in EPH gestosis patients than in normal pregnant and non-pregnant women. Platelet aggregation, platelet release response induced by ADP and collagen and the aggregation induced by A23187 were inhibited in taurine-loaded PS from non-pregnant women. These results suggest that the decrease of platelet aggregation in EPH gestosis patients was caused by high concentrations of taurine in platelets, which may inhibit the intracellular Ca2+ movement and platelet release response. Therefore, taurine appears to have a protective effect against the hyper-coagulative state in EPH gestosis.</p

    Platelet taurine concentration and uptake in gestosis patients with edema, proteinuria and hypertension.

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    The taurine concentration and uptake in platelets obtained from normal pregnant women and gestosis patients with edema, proteinuria and hypertension (EPH gestosis) were investigated. The taurine concentration in platelets showed a marked increase in severe EPH gestosis compared with normal pregnancy or mild and moderate EPH gestosis, while the plasma taurine concentration did not change significantly. Taurine uptake in platelets paralleled the severity of EPH gestosis. The Vmax of the uptake in severe EPH gestosis was about 2.4 times higher than that in normal pregnancy or mild and moderate EPH gestosis, but no significant difference was seen in the Km value among these groups.</p

    Fetal and neonatal excretion of free and conjugated ritodrine.

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    The ability of the human fetus and neonate to conjugate and excrete ritodrine, a beta 2-sympathomimetic drug, was investigated. Free and conjugated ritodrine concentrations in the plasma, amniotic fluid and urine were measured in 11 mother-infant pairs, to whom intravenous ritodrine had been administered before elective cesarean section at term. Ritodrine was determined by HPLC with electrochemical detection. At delivery, conjugated ritodrine values were significantly higher than those for the free form in maternal and fetal plasma. There were significant positive correlations between the concentrations in the maternal and umbilical vein plasma for both free and conjugated ritodrine. In the amniotic fluid, the total ritodrine concentrations were much higher than those in the fetal plasma, the conjugated form accounting for 90.2% of the total. Furthermore, the percentages of conjugated ritodrine in the amniotic fluid and neonatal urine were significantly higher than the percentage in the maternal urine on the day of birth. In the neonatal urine, the concentrations of free and conjugated ritodrine decreased rapidly after birth as did those in the maternal urine, on day 3 postpartum being less than 2% of the values on the day of parturition. These results indicate that the fetus at term is capable of forming conjugated metabolites of ritodrine and of excreting free and conjugated ritodrine in its urine.</p

    Mutation Analysis of 2009 Pandemic Influenza A(H1N1) Viruses Collected in Japan during the Peak Phase of the Pandemic

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    BACKGROUND: Pandemic influenza A(H1N1) virus infection quickly circulated worldwide in 2009. In Japan, the first case was reported in May 2009, one month after its outbreak in Mexico. Thereafter, A(H1N1) infection spread widely throughout the country. It is of great importance to profile and understand the situation regarding viral mutations and their circulation in Japan to accumulate a knowledge base and to prepare clinical response platforms before a second pandemic (pdm) wave emerges. METHODOLOGY: A total of 253 swab samples were collected from patients with influenza-like illness in the Osaka, Tokyo, and Chiba areas both in May 2009 and between October 2009 and January 2010. We analyzed partial sequences of the hemagglutinin (HA) and neuraminidase (NA) genes of the 2009 pdm influenza virus in the collected clinical samples. By phylogenetic analysis, we identified major variants of the 2009 pdm influenza virus and critical mutations associated with severe cases, including drug-resistance mutations. RESULTS AND CONCLUSIONS: Our sequence analysis has revealed that both HA-S220T and NA-N248D are major non-synonymous mutations that clearly discriminate the 2009 pdm influenza viruses identified in the very early phase (May 2009) from those found in the peak phase (October 2009 to January 2010) in Japan. By phylogenetic analysis, we found 14 micro-clades within the viruses collected during the peak phase. Among them, 12 were new micro-clades, while two were previously reported. Oseltamivir resistance-related mutations, i.e., NA-H275Y and NA-N295S, were also detected in sporadic cases in Osaka and Tokyo

    Impact of Bevacizumab Being Skipped due to Adverse Events of Special Interest for Bevacizumab in Patients with Unresectable Hepatocellular Carcinoma Treated with Atezolizumab plus Bevacizumab: An Exploratory Analysis of the Phase III IMbrave150 Study

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    Introduction: The phase III IMbrave150 study established atezolizumab + bevacizumab as the global standard of care in patients with unresectable hepatocellular carcinoma (HCC). This exploratory analysis examined the impact of bevacizumab interruption due to bevacizumab adverse events of special interest (AESIs). Methods: Patients in IMbrave150 who were randomized to atezolizumab + bevacizumab and received treatment for ≥6 months (to reduce immortal time bias) were included in group A-1 if bevacizumab had ever been skipped due to bevacizumab AESIs or to group A-2 otherwise. Efficacy analyses included overall survival (OS) and progression-free survival (PFS) by whether bevacizumab was skipped (group A-1 vs. A-2). PFS was evaluated per independent review facility (IRF)-assessed Response Evaluation Criteria in Solid Tumours (RECIST) version 1.1 and HCC-modified RECIST (IRF-HCC mRECIST). Safety was also evaluated. Results: Of the 210 patients who received ≥6 months of atezolizumab + bevacizumab, 69 were assigned to group A-1 and 141 to A-2. At data cutoff (August 20, 2020), hazard ratio (HR) for OS was 1.04 (95% CI: 0.64, 1.69) for group A-1 versus A-2. HR for PFS was 1.07 (95% CI: 0.74, 1.55) per IRF-assessed RECIST 1.1 and 1.10 (95% CI: 0.76, 1.59; 15.5 vs. 9.7 months) per IRF-HCC mRECIST for group A-1 versus A-2. Safety profiles for atezolizumab and bevacizumab were largely similar between groups. More group A-1 patients had grade 3/4 adverse events. A separate analysis investigating the impact of immortal time bias in patients who received ≥3 months of atezolizumab + bevacizumab supported the appropriateness of the ≥6-month landmark analysis. Discussion/Conclusion: Efficacy was similar between patients who skipped bevacizumab due to bevacizumab AESIs and those who did not. Although this comparison was nonrandomized and exploratory, results suggest that skipping bevacizumab due to bevacizumab AESIs did not considerably impact the efficacy and safety of atezolizumab + bevacizumab

    Neuronal diversity of the amygdala and the bed nucleus of the stria terminalis

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    The amygdala complex is a diverse group of more than 13 nuclei, segregated in five major groups: the basolateral (BLA), central (CeA), medial (MeA), cortical (CoA), and basomedial (BMA) amygdala nuclei. These nuclei can be distinguished depending on their cytoarchitectonic properties, connectivity, genetic, and molecular identity, and most importantly, on their functional role in animal behavior. The extended amygdala includes the CeA and the bed nucleus of the stria terminalis (BNST). Both CeA and the BNST share similar cellular organization, including common neuron types, reciprocal connectivity, and many overlapping downstream targets. In this section, we describe the advances of our knowledge on neuronal diversity in the amygdala complex and the BNST, based on recent functional studies, performed at genetic, molecular, physiological, and anatomical levels in rodent models, especially rats and mice. Molecular and connection property can be used separately, or in combinations, to define neuronal populations, leading to a multiplexed neuronal diversity-supporting different functional roles. © 2020 Elsevier B.V
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