79 research outputs found

    Explaining the DAMPE data with scalar dark matter and gauged U(1)Le−LμU(1)_{L_e-L_\mu} interaction

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    Inspired by the peak structure observed by recent DAMPE experiment in e+e−e^+e^- cosmic-ray spectrum, we consider a scalar dark matter (DM) model with gauged U(1)Le−LμU(1)_{L_e-L_\mu} symmetry, which is the most economical anomaly-free theory to potentially explain the peak by DM annihilation in nearby subhalo. We utilize the process χχ→Z′Z′→llˉl′lˉ′\chi \chi \to Z^\prime Z^\prime \to l \bar{l} l^\prime \bar{l}^\prime, where χ\chi, Z′Z^\prime, l(′)l^{(\prime)} denote the scalar DM, the new gauge boson and l(′)=e,μl^{(\prime)} =e, \mu, respectively, to generate the e+e−e^+e^- spectrum. By fitting the predicted spectrum to the experimental data, we obtain the favored DM mass range mχ≃3060−100+80 GeVm_\chi \simeq 3060^{+80}_{-100} \, {\rm GeV} and Δm≡mχ−mZ′≲14 GeV\Delta m \equiv m_\chi - m_{Z^\prime} \lesssim 14 \, {\rm GeV} at 68%68\% Confidence Level (C.L.). Furthermore, we determine the parameter space of the model which can explain the peak and meanwhile satisfy the constraints from DM relic abundance, DM direct detection and the collider bounds. We conclude that the model we consider can account for the peak, although there exists a tension with the constraints from the LEP-II bound on mZ′m_{Z^\prime} arising from the cross section measurement of e+e−→Z′∗→e+e−e^+e^- \to Z^{\prime\ast} \to e^+ e^-.Comment: 15 pages, 4 figure

    In-situ Thermophysical Measurement of Flowing Molten Chloride Salt Using Modulated Photothermal Radiometry

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    Molten salts are a leading candidate for high-temperature heat transfer fluids (HTFs) for thermal energy storage and conversion systems in concentrated solar power (CSP) and nuclear energy power plants. The ability to probe molten salt thermal transport properties in both stationary and flowing status is important for the evaluation of their heat transfer performance under realistic operational conditions, including the temperature range and potential degradation due to corrosion and contamination. However, accurate thermal transport properties are usually challenging to obtain even for stagnant molten salts due to different sources of errors from convection, radiation, and corrosion, let alone flowing ones. To the best of authors' knowledge, there is no available in-situ technique for measuring flowing molten salt thermal conductivity. Here, we report the first in-situ flowing molten salt thermal conductivity measurement using modulated photothermal radiometry (MPR). We could successfully perform the first in-situ thermal conductivity measurement of flowing molten NaCl−KCl−MgCl2NaCl-KCl-MgCl_2 in the typical operating temperature (520 and 580 oC^oC) with flow velocities ranging from around 0.3 to 1.0 mms−1s^-1. The relative change of the molten salt thermal conductivity was measured. Gnielinski's correlation was also used to estimate the heat transfer coefficient h of the flowing NaCl−KCl−MgCl2NaCl-KCl-MgCl_2 in the given experimental condition. The work showed the potential of the MPR technique serving as an in-situ diagnostics tool to evaluate the heat transfer performance of flowing molten salts and other high-temperature HTFs

    N-Acetylation phenotype and genotype and risk of bladder cancer in benzidine-exposed workers

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    Several studies in subjects occupationally exposed to arylamine carcinogens have shown increased risks for bladder cancer associated with the slow acetylator phenotype. To follow up these reports, a case-control study of N-acetylation and bladder cancer risk was carried out among subjects occupationally exposed to benzidine, in benzidine dye production and use facilities in China. Thirty-eight bladder cancer cases and 43 controls from these factories were included for study of acetylation phenotype, by dapsone administration, and for polymorphisms in the NAT2 gene, by a polymerase chain reaction (PCR)-based test. In contrast to previous studies, no increase in bladder cancer risk was found for the slow N-acetylation phenotype (OR= 0.3; 95% CI = 0.1-1.3) or for slow N-acetylation-associated double mutations in NAT2 (OR = 0.5; 95% CI = 0.1-1.8). Examination of specific mutations and adjustment for age, weight, city and tobacco use did not alter the results. When examined by level of benzidine exposure in the cases, the bladder cancer risks associated with low (OR = 0.3, 95% CI = 0.0-2.2), medium (OR = 0.7, 95% CI = 0.1-4.5) and high (OR = 0.6, 95% CI = 0.1-3.5) exposure showed no interaction between genotype and benzidine exposure, within the range of exposures experienced by subjects in this study. This study, which is the first to incorporate phenotypic and genotypic analyses, provides evidence that the NAT2-related slow N-acetylation polymorphism is not associated with an increased risk of bladder cancer in workers exposed to benzidine, and may have a protective effec

    Increased co-expression of TIM-3 with TIGIT or 2B4 on CD8+ T cells is associated with poor prognosis in locally advanced nasopharyngeal carcinoma

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    The use of immune checkpoint inhibitors in malignant tumors improves patient outcomes. Because single-agent immune checkpoint blockade has a low objective response rate, it is meaningful to explore combined blockade of immune checkpoint receptors. We aimed to investigate the co-expression of TIM-3 with TIGIT or 2B4 on peripheral blood CD8+ T cells from patients with locally advanced nasopharyngeal carcinoma. The correlation between co-expression level and clinical characteristics and prognosis was studied to provide a basis for immunotherapy for nasopharyngeal carcinoma. Flow cytometry was used to detect TIM-3/TIGIT and TIM-3/2B4 co-expression on CD8+ T cells. The differences in co-expression between patients and healthy controls were analyzed. The correlation between co-expression of TIM-3/TIGIT or TIM-3/2B4 and the patient clinical characteristics and prognosis was examined. Also, the correlation between the TIM-3/TIGIT or 2B4 co-expression and other common inhibitory receptors was analyzed. We further validated our results using mRNA data from the Gene Expression Omnibus (GEO) database. TIM-3/TIGIT and TIM-3/2B4 co-expression was upregulated on peripheral blood CD8+ T cells from patients with nasopharyngeal carcinoma. They were both correlated with poor prognosis. There was a correlation between TIM-3/TIGIT co-expression and patient age and pathological stage, whereas TIM-3/2B4 co-expression correlated with age and sex. CD8+ T cells with elevated mRNA levels of TIM3/TIGIT and TIM3/2B4 also showed increased expression of multiple inhibitory receptors, indicating T cell exhaustion in locally advanced nasopharyngeal carcinoma. TIM-3/TIGIT or TIM-3/2B4 can be used as potential targets for combination immunotherapy in locally advanced nasopharyngeal carcinoma

    A comprehensive insight into the effects of acidification on varied-sized pores in different rank coals

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    Elucidating the evolution law of coal pore structure under acidification is crucial for guiding the practical application of acidizing technology and improving the production of coalbed methane. To comprehensively investigate the influence of acidification on varied-sized pores in different rank coals, in this study, fat coal, meagre coal and anthracite coal were collected and acidified with a mixed solution composed of hydrochloric acid (9 wt%) and hydrofluoric acid (3 wt%). An approach integrating low-pressure CO2 adsorption (LPGA-CO2), low-temperature N2 adsorption (LTGA-N2) and Mercury intrusion porosimetry (MIP) was adopted to fully characterize the varied-sized pore structure before and after acidification to eliminate the limitations of single method. The results demonstrated that acid treatment improved the pore opening degree and connectivity in coal, but had essentially no effect on the pore shape. After acidification, all the coal samples showed significant increases in the porosity and total pore volume, which was mainly contributed by the numerous newly formed large mesopores and macropores, especially the macropores (with an average contribution rate of 74.59%). Taken as a whole, acid treatment had the largest impact on macropores, followed by mesopores, and the smallest impact on micropores. In addition, the variation trend of total specific surface area (SSA) under acidification was primarily determined by micropores. For the three different rank coals selected in this study, the total SSA of fat coal (PM) was more easily affected by acidification and had the largest percentage increase after acid treatment, followed by anthracite coal (YM), while that of meagre coal (LA) decreased slightly. This difference was driven primarily by the different variation trend of micropore SSA in different rank coals. After acidification, the SSA of ultra-micropores and super-micropores all increased in fat coal (PM) and anthracite coal (YM), whereas for meagre coal (LA), although ultra-micropores SSA increased, super-micropores SSA decreased, which ultimately led to the slight decrease of its micropore SSA. Moreover, the total pore volume increment of coal was closely related to the macropore volume increment under acidification, but not significantly related to the coal maturity,which might indicate that, compared with coal rank, the mineral content in coal might be a more important consideration when measuring the applicability of acidification technology

    The association between gene polymorphisms in voltage-gated potassium channels Kv2.1 and Kv4.2 and susceptibility to autism spectrum disorder

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    BackgroundAutism spectrum disorder (ASD) is a heritable form of neurodevelopmental disorder that arises through synaptic dysfunction. Given the involvement of voltage-gated potassium (Kv) channels in the regulation of synaptic plasticity, we aimed to explore the relationship between the genetic variants in the KCNB1 and KCND2 genes (encoding Kv2.1 and Kv4.2, respectively) and the risk of developing ASD.MethodsA total of 243 patients with ASD and 243 healthy controls were included in the present study. Sixty single nucleotide polymorphisms (SNPs) (35 in KCNB1 and 25 in KCND2) were genotyped using the Sequenom Mass Array.ResultsThere were no significant differences in the distribution of allele frequencies and genotype frequencies in KCNB1 between cases and controls. However, the differences were significant in the allelic distribution of KCND2 rs1990429 (pBonferroni < 0.005) and rs7793864 (pBonferroni < 0.005) between the two groups. KCND2 rs7800545 (pFDR = 0.045) in the dominant model and rs1990429 (pFDR < 0.001) and rs7793864 (pFDR < 0.001) in the over-dominant model were associated with ASD risk. The G/A genotype of rs1990429 in the over-dominant model and the G/A–G/G genotype of rs7800545 in the dominant model were correlated with lower severity in the Autism Diagnostic Interview-Revised (ADI–R) restricted repetitive behavior (RRB) domain.ConclusionOur results provide evidence that KCND2 gene polymorphism is strongly associated with ASD susceptibility and the severity of RRB

    Patterns of attentional bias in antenatal depression: an eye-tracking study

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    IntroductionOne of the most common mental disorders in the perinatal period is depression, which is associated with impaired emotional functioning due to alterations in different cognitive aspects including thought and facial emotion recognition. These functional impairment may affect emerging maternal sensitivity and have lasting consequences for the dyadic relationship. The current study aimed to investigate the impact of depressive symptoms on the attention bias of infant stimuli during pregnancy.MethodsEighty-six pregnant women completed the Edinburgh Postnatal Depression Scale and an eye-tracking task comprising infant-related emotion images. All participants showed biased attention to infant-related images.ResultsFirst, compared to healthy pregnant women, pregnant women with depression symptoms initially directed their attention to infant-related stimuli more quickly (F (1, 84) = 6.175, p = 0.015, η2 = 0.068). Second, the two groups of pregnant women paid attention to the positive infant stimuli faster than the neutral infant stimuli, and the first fixation latency bias score was significantly smaller than that of the infant-related negative stimulus (p = 0.007). Third, compared with the neutral stimulus, the non-depression group showed a longer first gaze duration to the negative stimulus of infants (p = 0.019), while the depressive symptoms group did not show this difference.ConclusionWe speculate that structural and functional changes in affective motivation and cognitive-attention brain areas may induce these attentional bias patterns. These results provide suggestions for the implementation of clinical intervention programs to correct the attention bias of antenatal depressed women

    Single cell atlas for 11 non-model mammals, reptiles and birds.

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    The availability of viral entry factors is a prerequisite for the cross-species transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Large-scale single-cell screening of animal cells could reveal the expression patterns of viral entry genes in different hosts. However, such exploration for SARS-CoV-2 remains limited. Here, we perform single-nucleus RNA sequencing for 11 non-model species, including pets (cat, dog, hamster, and lizard), livestock (goat and rabbit), poultry (duck and pigeon), and wildlife (pangolin, tiger, and deer), and investigated the co-expression of ACE2 and TMPRSS2. Furthermore, cross-species analysis of the lung cell atlas of the studied mammals, reptiles, and birds reveals core developmental programs, critical connectomes, and conserved regulatory circuits among these evolutionarily distant species. Overall, our work provides a compendium of gene expression profiles for non-model animals, which could be employed to identify potential SARS-CoV-2 target cells and putative zoonotic reservoirs
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