Development and preliminary verification of a 1D–3D coupled flow and heat transfer model of OTSG

Introduction: A simulation model was developed by coupling a one-dimensional (1D) system code and 3D CFD software, to analyze the three-dimensional (3D) flow and heat transfer characteristics of the once-through steam generator (OTSG).Methods: The shell side of the OTSG was simulated by FLUENT, and the tube side was simulated by the system code LOCUST. Through spatial mapping, the 1D and 3D simulations were coupled along the outer wall of the OTSG's helically coiled tubes.Results and Discussion: This coupling method enabled the acquisition of high-resolution flow and heat transfer characteristics of the OTSG, and the error of heat flux calculation result by the coupled model is within 15%. Through coupling simulation analysis of the prototype OTSG, it was found that the inlet and outlet temperature difference reached as high as 150°C. The unevenness of the radial temperature distribution increased along the flow direction, and the wake swing effect caused by the sweeping flow of the tube bundle at the exit position was evident. The results of this study provide reference and a coupled simulation method for the engineering design and thermal-hydraulic characteristics analysis of OTSG

Identification of pathogenic mutations for a Wolfram syndrome pedigree by whole exome sequencing and analysis of its clinical characteristics

Objective·To identify the causative gene and mutations and describe the clinical traits in a Chinese diabetes pedigree suspected of Wolfram syndrome.Methods·A total of 12 subjects from one family were included. The proband was admitted to the Department of Endocrinology, The First Affiliated Hospital of Xinxiang Medical University, for the first time in May 2013. Then he visited the hospital for follow-up in July 2022 and in April 2023, respectively. The other members of this family included the proband′s sister, father, mother, paternal grandfather, paternal grandmother, uncle, aunt, as well as maternal grandfather, maternal grandmother, and two brothers of the proband′s mother. Clinical data of all subjects were collected. The whole exome sequencing was used to screen the pathogenic genes and mutation sites of six members of the family, and Sanger sequencing was used to verify the above results. Effects of the mutation of the pathogenic gene WFS1 in Wolfram syndrome on the function of the wolframin protein were evaluated by bioinformatics softwares, including CADD, DANN, MetaSVM, Polyphen-2, SIFT and M-CAP. The three-dimensional structures of wild-type and mutant wolframin proteins were constructed with Swiss-Model software, and visualized with PyMOL software. Cluster Omega software was used for evaluating species conservation of WFS1 gene mutation sites. JNetPRED software was used for online prediction of wolframin protein secondary structure.Results·The proband and his sister both carried R558H and S411Cfs*131 mutations, two compound heterozygous mutations of the Wolfram syndrome pathogenic gene WFS1. The proband′s father and parental grandfather both carried the R558H mutation, while the proband′s mother and maternal grandfather both carried the S411Cfs*131 mutation. The R558H mutation was a rare missense mutation, and the S411Cfs*131 mutation was a novel frameshift mutation. Bioinformatics analysis softwares predicted that the R558H mutation located in the α-helical structure of the wolframin protein. This mutation was a damage mutation and the amino acid sequence of the mutation region was highly conservative among 12 species with varying degrees of evolution, including humans.Conclusion·Two causative mutations of WFS1 gene are identified in a Chinese diabetes pedigree by whole exome sequencing. The study supplements the existing genotype and phenotype profiles of Wolfram syndrome, which can realize early diagnosis of diabetes pedigrees and help in performing timely follow-up of patients, so as to achieve early intervention and treatment of this disease

Forty years of reform and opening up:China’s progress toward a sustainable path

After 40 years of reform and “opening up,” China has made remarkable economic progress. Such economic prosperity, however, has been coupled with environmental degradation. We analyze diverse long-term data to determine whether China is experiencing a decoupling of economic growth and environmental impacts, and where China stands with respect to the Sustainable Development Goals (SDGs) in terms of reducing regional division, urban-rural gap, social inequality, and land-based impacts on oceans. The results highlight that China’s desire to achieve “ecological civilization” has resulted in a decoupling trend for major pollutants since 2015, while strong coupling remains with CO2 emissions. Progress has been made in health care provision, poverty reduction, and gender equity in education, while income disparity continues between regions and with rural-urban populations. There is a considerable way to go toward achieving delivery of the SDGs; however, China’s progress toward economic prosperity and concomitant sustainability provides important insights for other countries

Single-cell-resolution transcriptome map revealed novel genes involved in testicular germ cell progression and somatic cells specification in Chinese tongue sole with sex reversal

19 pages, 7 figures, supporting information https://doi.org/10.1007/s11427-021-2236-4.-- Data availability: The data reported in this study are available in the CNGB Nucleotide Sequence Archive (CNSA: https://db.cngb.org/cnsa; accession number CNP0002135).Female-to-male sex reversals (pseudomales) are common in lower vertebrates and have been found in natural populations, which is a concern under rapid changes in environmental conditions. Pseudomales can exhibit altered spermatogenesis. However, the regulatory mechanisms underlying pseudomale spermatogenesis remain unclear. Here, we characterized spermatogenesis in Chinese tongue sole (Cynoglossus semilaevis), a species with genetic and environmental sex determination, based on a high-resolution single-cell RNA-seq atlas of cells derived from the testes of genotypic males and pseudomales. We identified five germ cell types and six somatic cell types and obtained a single-cell atlas of dynamic changes in gene expression during spermatogenesis in Chinese tongue sole, including alterations in pseudomales. We detected decreased levels of Ca2+ signaling pathway-related genes in spermatogonia, insufficient meiotic initiation in spermatocytes, and a malfunction of somatic niche cells in pseudomales. However, a cluster of CaSR genes and MAPK signaling factors were upregulated in undifferentiated spermatogonia of pseudomales. Additionally, we revealed that Z chromosome-specific genes, such as piwil2, dhx37, and ehmt1, were important for spermatogenesis. These results improve our understanding of reproduction after female-to-male sex-reversal and provide new insights into the adaptability of reproductive strategies in lower vertebratesThis work was supported by the National Key R&D Program of China (2018YFD0900301), the National Nature Science Foundation of China (31722058, 31802275, 31472269), the AoShan Talents Cultivation Program Supported by Qingdao National Laboratory for Marine Science and Technology (2017ASTCP-ES06), the Taishan Scholar Project Fund of Shandong of China to C.S., the National Ten-Thousands Talents Special Support Program to C.S., the Central Public-interest Scientific Institution Basal Research Fund, CAFS (2020TD19) and the China Agriculture Research System (CARS-47-G03)With the institutional support of the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S)Peer reviewe

Upper ocean biogeochemistry of the oligotrophic North Pacific Subtropical Gyre : from nutrient sources to carbon export

Subtropical gyres cover 26–29% of the world’s surface ocean and are conventionally regarded as ocean deserts due to their permanent stratification, depleted surface nutrients, and low biological productivity. Despite tremendous advances over the past three decades, particularly through the Hawaii Ocean Time-series and the Bermuda Atlantic Time-series Study, which have revolutionized our understanding of the biogeochemistry in oligotrophic marine ecosystems, the gyres remain understudied. We review current understanding of upper ocean biogeochemistry in the North Pacific Subtropical Gyre, considering other subtropical gyres for comparison. We focus our synthesis on spatial variability, which shows larger than expected dynamic ranges of properties such as nutrient concentrations, rates of N2 fixation, and biological production. This review provides new insights into how nutrient sources drive community structure and export in upper subtropical gyres. We examine the euphotic zone in subtropical gyres as a two-layered vertically structured system: a nutrient-depleted layer above the top of the nutricline in the well-lit upper ocean and a nutrient-replete layer below in the dimly lit waters. These layers vary in nutrient supply and stoichiometries and physical forcing, promoting differences in community structure and food webs, with direct impacts on the magnitude and composition of export production. We evaluate long-term variations in key biogeochemical parameters in both of these euphotic zone layers. Finally, we identify major knowledge gaps and research challenges in these vast and unique systems that offer opportunities for future studies

Real-time Monitoring for the Next Core-Collapse Supernova in JUNO

Core-collapse supernova (CCSN) is one of the most energetic astrophysical events in the Universe. The early and prompt detection of neutrinos before (pre-SN) and during the SN burst is a unique opportunity to realize the multi-messenger observation of the CCSN events. In this work, we describe the monitoring concept and present the sensitivity of the system to the pre-SN and SN neutrinos at the Jiangmen Underground Neutrino Observatory (JUNO), which is a 20 kton liquid scintillator detector under construction in South China. The real-time monitoring system is designed with both the prompt monitors on the electronic board and online monitors at the data acquisition stage, in order to ensure both the alert speed and alert coverage of progenitor stars. By assuming a false alert rate of 1 per year, this monitoring system can be sensitive to the pre-SN neutrinos up to the distance of about 1.6 (0.9) kpc and SN neutrinos up to about 370 (360) kpc for a progenitor mass of 30$M_{\odot}$ for the case of normal (inverted) mass ordering. The pointing ability of the CCSN is evaluated by using the accumulated event anisotropy of the inverse beta decay interactions from pre-SN or SN neutrinos, which, along with the early alert, can play important roles for the followup multi-messenger observations of the next Galactic or nearby extragalactic CCSN.Comment: 24 pages, 9 figure

Potential of Core-Collapse Supernova Neutrino Detection at JUNO

JUNO is an underground neutrino observatory under construction in Jiangmen, China. It uses 20kton liquid scintillator as target, which enables it to detect supernova burst neutrinos of a large statistics for the next galactic core-collapse supernova (CCSN) and also pre-supernova neutrinos from the nearby CCSN progenitors. All flavors of supernova burst neutrinos can be detected by JUNO via several interaction channels, including inverse beta decay, elastic scattering on electron and proton, interactions on C12 nuclei, etc. This retains the possibility for JUNO to reconstruct the energy spectra of supernova burst neutrinos of all flavors. The real time monitoring systems based on FPGA and DAQ are under development in JUNO, which allow prompt alert and trigger-less data acquisition of CCSN events. The alert performances of both monitoring systems have been thoroughly studied using simulations. Moreover, once a CCSN is tagged, the system can give fast characterizations, such as directionality and light curve

Detection of the Diffuse Supernova Neutrino Background with JUNO

As an underground multi-purpose neutrino detector with 20 kton liquid scintillator, Jiangmen Underground Neutrino Observatory (JUNO) is competitive with and complementary to the water-Cherenkov detectors on the search for the diffuse supernova neutrino background (DSNB). Typical supernova models predict 2-4 events per year within the optimal observation window in the JUNO detector. The dominant background is from the neutral-current (NC) interaction of atmospheric neutrinos with 12C nuclei, which surpasses the DSNB by more than one order of magnitude. We evaluated the systematic uncertainty of NC background from the spread of a variety of data-driven models and further developed a method to determine NC background within 15\% with {\it{in}} {\it{situ}} measurements after ten years of running. Besides, the NC-like backgrounds can be effectively suppressed by the intrinsic pulse-shape discrimination (PSD) capabilities of liquid scintillators. In this talk, I will present in detail the improvements on NC background uncertainty evaluation, PSD discriminator development, and finally, the potential of DSNB sensitivity in JUNO