601 research outputs found

    Production properties of deuterons, helions and tritons via an analytical nucleon coalescence method in Pb-Pb collisions at sNN=2.76\sqrt{s_{NN}}=2.76 TeV

    Full text link
    We improve a nucleon coalescence model to include the coordinate-momentum correlation in nucleon joint distributions, and apply it to Pb-Pb collisions at sNN=2.76\sqrt{s_{NN}}=2.76 TeV to study production properties of deuterons (dd), helions (3^3He) and tritons (tt). We give formulas of the coalescence factors B2B_2 and B3B_3, and naturally explain their behaviors as functions of the collision centrality and the transverse momentum per nucleon pT/Ap_T/A. We reproduce the transverse momentum spectra, averaged transverse momenta and yield rapidity densities of dd, 3^3He and tt, and find the system effective radius obtained in the coalescence production of light nuclei behaves similarly to Hanbury Brown-Twiss interferometry radius. We particularly give expressions of yield ratios d/pd/p, 3^3He/d/d, t/pt/p, 3^3He/p/p, d/p2d/p^{2}, 3^3He/p3/p^3, t/3t/^3He and argue their nontrivial behaviors can be used to distinguish production mechanisms of light nuclei.Comment: 12 pages, 8 figures, 1 tabl

    Optimizing Vehicle Scheduling Based on Variable Timetable by Benders-and-Price Approach

    Get PDF
    In practice, vehicle scheduling is planned on a variable timetable so that the departure times of trips can be shifted in tolerable ranges, rather than on a fixed timetable, to decrease the required fleet size. This paper investigates the vehicle scheduling problem on a variable timetable with the constraint that each vehicle can perform limited trips. Since the connection-based model is difficult to solve by optimization software for a medium-scale or large-scale instance, a designed path-based model is developed. A Benders-and-Price algorithm by combining the Benders decomposition and column generation is proposed to solve the LP-relaxation of the path-based model, and a bespoke Branch-and-Price is used to obtain the integer solution. Numerical experiments indicate that a variable timetable approach can reduce the required fleet size with a tolerable timetable deviation in comparison with a fixed timetable approach. Moreover, the proposed algorithm is greatly superior to GUROBI in terms of computational efficiency and guarantees the quality of the solution. Document type: Articl

    Primary localized histoplasmosis with lesions restricted to the mouth in a Chinese HIV-negative patient

    Get PDF
    SummaryHistoplasmosis is a deep mycosis caused by Histoplasma capsulatum, which is endemic in many areas of the world but is relatively rare in China. Although the majority of cases present as a mild to moderate flu-like disease requiring only supportive therapy, approximately 1% of patients experience more serious pulmonary and extrapulmonary disease, which can be life-threatening if diagnosis is delayed or the treatment is not initiated rapidly. Definitive diagnosis is usually made by a combination of culture, detection of the organism in tissues, measurement of antibodies, and detection of antigen. We present the case of a 51-year-old patient who presented with histoplasmosis only, with several ulcerated lesions in the oral cavity and without HIV infection, who did not show any detectable signs and symptoms of systemic disease or extra-oral manifestations. Histopathological analysis indicated a chronic inflammatory process with granulomas with yeast-like organisms. Isolation of H. capsulatum and molecular identification provided the definitive diagnosis. Treatment with oral itraconazole led to remission of the oral lesions. This is the first Chinese case report of localized histoplasmosis with lesions restricted to the mouth in an HIV-negative patient

    Different Coalescence Sources of Light Nuclei Production in Au-Au Collisions at sNN=3\sqrt{s_{NN}}=3 GeV

    Full text link
    We study the production of light nuclei in the coalescence mechanism in Au-Au collisions at midrapidity at sNN=3\sqrt{s_{NN}}=3 GeV. We derive analytic formulas of momentum distributions of two bodies, three bodies and four nucleons coalescing into light nuclei, respectively. We naturally explain the transverse momentum spectra of the deuteron (dd), triton (tt), helium-3 (3^3He) and helium-4 (4^4He). We reproduce the data of yield rapidity densities and averaged transverse momenta of dd, tt, 3^3He and 4^4He. We give proportions of contributions from different coalescence sources for tt, 3^3He and 4^4He in their productions. We find that besides nucleon coalescence, nucleon++nucleus coalescence and nucleus++nucleus coalescence may play requisite roles in light nuclei production in Au-Au collisions at sNN=3\sqrt{s_{NN}}=3 GeV.Comment: 5 figures, 6 table

    Changes of plasma fibroblast growth factor-21 (FGF-21) in oral glucose tolerance test and effects of metformin on FGF-21 levels in type 2 diabetes mellitus

    Get PDF
    Wstęp: Badanie przeprowadzono w celu ustalenia, czy czynnik wzrostu fibroblastów-21 (FGF-21) uczestniczy w regulacji stężenia glukozy i czy zastosowanie metforminy u chorych na cukrzycę wpływa na stężenie FGF-21. Materiał i metody: Do badania włączono 43 osoby, w tym 27 chorych z nowo rozpoznaną cukrzycą typu 2 (nT2DM). U wszystkich przeprowadzono test doustnego obciążenia 75 g glukozy (OGTT). Próbki krwi pobrano w 0., 60.,120. i 180. minucie testu. Osobom z nT2DM zaproponowano udział w dalszych badaniach; zastosowano u nich metforminę w dawce 1,0 g/dobę przez tydzień. Wyniki: Zmiany stężenia FGF-21 w osoczu podczas OGTT zaobserwowano tylko w grupie chorych na nT2DM; w grupie kontrolnej stężenie FGF-21 pozostało niezmienione. Nie stwierdzono, by stężenia FGF-21 w poszczególnych punktach czasowych różniły się w zależności od płci badanych (p < 0,05). Zastosowanie metforminy u osób z nT2DM spowodowało istotne zmniejszenie stężeń glukozy i FGF-21 we wszystkich punktach czasowych OGTT oraz zmniejszenie stężenia insuliny w 60. i 180. minucie, co wskazuje na obniżenie wskaźnika HOMA-IR. Wnioski: FGF-21 nie uczestniczy w krótkoterminowej regulacji glikemii u ludzi, a zmiany jego stężenia podczas OGTT są opóźnione w T2DM. Być może FGF-21 bierze udział w metabolizowaniu metforminy, zwiększając wrażliwość na glukozę i insulinę. (Endokrynol Pol 2013; 64 (3): 220&#8211;224)Introduction: The objectives of our study were to investigate whether fibroblast growth factor-21 (FGF-21) is involved in short-term regulation of glucose and the change of FGF-21 after metformin use in diabetic subjects. Material and methods: 43 subjects were recruited in the study, including 27 new-onset type 2 diabetes patients (nT2DM). A 75 g oral glucose tolerance test (OGTT) was administered to them. Blood samples were taken at 0, 60 ,120 and 180 minute of OGTT. nT2DM subjects were invited for further investigation, metformin was administered in a dose of 1.0 g every day for 1 week. Results: Plasma FGF-21 changed significantly in the nT2DM group during the OGTT administration but not in the control group. No gender differences were observed at different time points in FGF-21 levels (p < 0.05). Administration of metformin for nT2DM resulted in a significant decrease in both glucose and FGF-21 at all OGTT times and in insulin at 60 min and 180 min, indicative of a decrease in HOMA-IR. Conclusion: FGF-21 does not seem to be involved in short-term regulation of glycaemia in human subjects, and the change in OGTT delayed in T2DM. FGF-21 may participate in the processing of metformin, improving glucose and insulin sensitivity. (Pol J Endocrinol 2013; 64 (3): 220&#8211;224

    Equivariant Flow Matching with Hybrid Probability Transport

    Full text link
    The generation of 3D molecules requires simultaneously deciding the categorical features~(atom types) and continuous features~(atom coordinates). Deep generative models, especially Diffusion Models (DMs), have demonstrated effectiveness in generating feature-rich geometries. However, existing DMs typically suffer from unstable probability dynamics with inefficient sampling speed. In this paper, we introduce geometric flow matching, which enjoys the advantages of both equivariant modeling and stabilized probability dynamics. More specifically, we propose a hybrid probability path where the coordinates probability path is regularized by an equivariant optimal transport, and the information between different modalities is aligned. Experimentally, the proposed method could consistently achieve better performance on multiple molecule generation benchmarks with 4.75×\times speed up of sampling on average.Comment: NeurIPS 202

    The Genetic Associations and Epistatic Effects of the CCR5 Promoter and CCR2-V64I Polymorphisms on Susceptibility to HIV-1 Infection in a Northern Han Chinese Population

    Get PDF
    The outcome of human immunodeficiency virus (HIV)-1 infection and course to AIDS are variable among individuals. Both chemokine receptor 5 (CCR5) and CCR2 gene polymorphisms play essential roles in the susceptibility of HIV-1 infection. To investigate the main and epistatic effects of the CCR5 promoter and CCR2-V64I polymorphisms on HIV-1 infection in the Northern Han Chinese, subjects of 91 HIV-1-infected patients and 91 health controls were recruited. Single-nucleotide polymorphisms (SNPs) in the CCR5 promoter region and CCR2-V64I variants were genotyped. In the single-locus analysis, CCR5 58755-G and CCR5 59653-T alleles were significantly associated with HIV-1 infection (odds ratio [OR]=0.529, 95% confidence interval [CI]: 0.295-0.948; OR=1.710, 95% CI: 1.039-2.814). After adjustment with age and gender, subjects with the CCR5 59653-CT genotype showed the increased risk of HIV-1 infection compared with those with the wild-type CC genotype (adjusted OR=2.502; 95% CI: 1.332-4.698). No positive association was observed in other SNPs. Haplotype-based association analysis revealed that the haplotype TATGC was associated with the susceptibility to HIV-1 infection (p=0.003). Besides, we found the significant epistatic effects between the CCR5 58755-A/G and CCR5 59029-A/G polymorphisms associated with the lower risk of HIV-1 infection. In addition, we also identified the best three-factor interaction model, including the CCR5 58755-A/G, 59029-A/G, and CCR2-V64I polymorphisms, indicating that there were also strong gene-gene interactions between the CCR5 promoter and CCR2 polymorphisms on the susceptibility of HIV-1 infection. These findings contribute to understanding the genetic mechanism for the susceptibility of HIV-1 infection in Northern Han Chinese
    corecore