亚硝酸盐对鱼类生长的影响

亚硝酸盐是铵氧化成硝酸盐过程的一个中间产物,水体中亚硝酸盐的存在将会对淡水鱼类的生长产生严重的威胁。本文对水体中亚硝酸盐的来源、吸收机制、生理影响、毒性及解毒机制等方面进行了阐述,以便人们对亚硝酸盐对鱼类生长的影响有一个深刻的了解。

水体中亚硝酸盐的来源与去除

亚硝酸盐是自然界中氮循环的一个中间产物,广泛存在于水体中,其生物毒性越来越受到人们的关注。本文阐述了水体中亚硝酸盐的来源、影响因素以及去除技术,并指出了解决水体中亚硝酸盐的现实意义。

A Precise Sensor for SF_6 Based on Piezoelectric Ultrasound

Based on piezoelectric ultrasound technology,the paper theoretically analyses the determination of gas concentration and presents a norm-contrast method,which is realized by high-speed chip CPLD (Complex programmable logic device),to determine the concentration of SF_6 accurately with air as background.It is proved that this sensor can determine the concentration of SF_6 with the precision of 50μg/g.The sensor is in the process of producing.

A double sideband combined tracking method for Galileo E5 AltBOC signals

The Galileo navigation satellite system(Galileo)E5 Alternative Binary Offset Carrier(AltBOC)signal brings various challenges due to its complex modulation,wide bandwidth,and multi-peaked auto-correlation function.While wideband tracking needs to solve the ambiguity problem and design dedicated baseband channels,the single-sideband cannot have the outstanding performance of the AltBOC signal.We propose a new tracking method called“Double Sideband Combined Tracking”(DSCT),which can fully exploit the AltBOC signal’s code tracking accuracy without ambiguity and ensure compatibility with Binary Phase Shift Keying(BPSK)processing channels,easily implemented in hardware.The DSCT employs one phase locked loop and one delay locked loop to track the carrier and code,respectively.The double-sideband correlation results used by the two loops are recovered by coherently combining the singlesideband correlation results of the two BPSK channels.Meanwhile,the combined model,the loop discriminator,and the ambiguity detection of the DSCT are discussed.Furthermore,the code tracking error caused by thermal noise is modeled and analyzed.The test results based on real Galileo E5 signals show that the DSCT exhibits better or comparable code tracking accuracy to the AltBOC wideband tracking method.When the loop falsely locks onto a sidepeak,the DSCT can quickly detect and re-lock on the main peak.

Optimal Gestational Weight Gain for Women with Gestational Diabetes Mellitus—China,2011–2021

Summary What is already known about this topic?Joint effects of gestational weight gain(GWG)and hyperglycemia on adverse pregnancy outcomes suggest that lower optimal GWG is optimal for women with gestational diabetes mellitus(GDM).However,there is still a lack of guidelines.What is added by this report?Optimal weekly GWG range after diagnosis of GDM for underweight,normal-weight,overweight,and obese women was 0.37–0.56 kg/week,0.26–0.48 kg/week,0.19–0.32 kg/week,and 0.12–0.23 kg/week,respectively.What are the implications for public health practice?The findings may be used to inform prenatal counseling regarding optimal gestational weight gain for women with gestational diabetes mellitus,and suggest the need for weight gain management.

Weekly Weight Gain in Women with Gestational Diabetes Mellitus and Neonatal Birth Weight - China, 2011–2021

What is already known about this topic?Elevated gestational weight gain(GWG)during pregnancy among women diagnosed with gestational diabetes mellitus(GDM)is correlated with an increased instance of large for gestational age(LGA)and macrosomia.However,it remains uncertain whether managing weekly GWG following a GDM diagnosis positively impacts fetal birth weight.What is added by this report?Our study found that GWG following GDM diagnosis correlates positively with the risk of LGA and macrosomia among all body mass index(BMI)subgroups,especially for overweight and obese women.What are the implications for public health practice?The results of this research highlight the importance of enforcing a more stringent regulation on GWG on a weekly basis for overweight and obese women diagnosed with GDM,particularly when considering neonatal growth.

Coupled single-cell and bulk RNA-seq analysis reveals the engulfment role of endothelial cells in atherosclerosis

The clearance of apoptotic cell debris,containing professional phagocytosis and non-professional phagocytosis,is essential for maintaining the homeostasis of healthy tissues.Here,we discovered that endothelial cells could engulf apoptotic cell debris in atherosclerotic plaque.Single-cell RNA sequencing(RNA-seq)has revealed a unique endothelial cell subpopulation in atherosclerosis,which was strongly associated with vascular injury-related pathways.Moreover,integrated analysis of three vascular injury-related RNA-seq datasets showed that the expression of scavenger receptor class B type 1(SR-B1)was up-regulated and specifically enriched in the phagocytosis pathway under vascular injury circumstances.Single-cell RNA-seq and bulk RNA-seq indicate that SR-B1 was highly expressed in a unique endothelial cell subpopulation of mouse aorta and strongly associated with the reorganization of cellular adherent junctions and cytoskeleton which were necessary for phagocytosis.Furthermore,SR-B1 was strongly required for endothelial cells to engulf apoptotic cell debris in atherosclerotic plaque of both mouse and human aorta.Overall,this study demonstrated that apoptotic cell debris could be engulfed by endothelial cells through SR-B1 and associated with the reorganization of cellular adherent junctions and cytoskeleton.

The oral microbiome of pregnant women facilitates gestational diabetes discrimination

The oral microbiota plays an important role in the development of various diseases,whereas its association with gestational diabetes mellitus (GDM) remains largely unclear.The aim of this study is to identify biomarkers from the oral microbiota of GDM patients by analyzing the microbiome of the saliva and dental plaque samples of 111 pregnant women.We find that the microbiota of both types of oral samples in GDM patients exhibits differences and significantly varies from that of patients with periodontitis or dental caries.Using bacterial biomarkers from the oral microbiota,GDM classification models based on support vector machine and random forest algorithms are constructed.The area under curve (AUC) value of the classification model constructed by combination of Lautropia and Neisseria in dental plaque and Streptococcus in saliva reaches 0.83,and the value achieves a maximum value of 0.89 by adding clinical features.These findings suggest that certain bacteria in either saliva or dental plaque can effectively distinguish women with GDM from healthy pregnant women,which provides evidence of oral microbiome as an informative source for developing noninvasive biomarkers of GDM.

具有可控释放能力和可抑制生物膜形成的聚多巴胺/银杂化涂层的钠钙玻璃球

过滤介质作为过滤装置中的关键材料可改变流经其中的水的质量.正确选择过滤介质对于过滤装置的过滤性能至关重要.再生玻璃作为介质过滤装置中硅砂的替代品,具有比硅砂廉价、环境友好、可再生等优点,并且可以根据特定的设计要求将其粉碎成不同的尺寸.然而,水中存在大量的诸如细菌和藻类的微生物,故再生的可循环玻璃介质的过滤效率受到在其表面富集的生物膜的极大限制.本研究中,我们通过在钠钙玻璃球(GS)表面上进行氢氟酸(HF)蚀刻和原位结晶制备了用聚多巴胺(PDA)和银(Ag)纳米颗粒改性的氢氟酸蚀刻玻璃球(PDA-Ag-HF/GSs).银晶体的原位生长、HF蚀刻和PDA涂层的改性赋予了PDA-Ag-HF/GS良好的亲水性.银涂层的改性还使得PDA-Ag-HF/GS具有出色的抗菌性能和较小的球藻附着力,且通过释放Ag离子可抑制微生物的生长.PDA涂层上的邻苯二酚官能团可通过螯合作用调节Ag离子的释放.良好的抗菌性能、抗藻类附着力和Ag离子的受控释放表明,PDA-AgHF/GS涂层可有效抑制材料表面生物膜的形成,为抗生物膜的形成提供了新的策略.

trans-2-Enoyl-CoA Reductase Tecr-Driven Lipid Metabolism in Endothelial Cells Protects against Transcytosis to Maintain Blood-Brain Barrier Homeostasis

The transport and metabolism of lipids in cerebrovascular endothelial cells(ECs)have been hypothesized to regulate blood-brain barrier(BBB)maturation and homeostasis.Long-chain polyunsaturated fatty acids(LCPUFAs)as the important lipids components of cell membranes are essential for the development and function of BBB,but the direct links of lipid metabolism and ECs barrier function remain to be established.Here,we comprehensively characterize the transcriptomic phenotype of developmental cerebrovascular ECs in single-cell resolution and firstly find that trans-2-enoyl-CoA reductase(Tecr),a verylong-chain fatty acid synthesis,is highly expressed during barriergenesis and decreased after BBB maturation.EC-specific knockout of Tecr compromises angiogenesis due to delayed vascular sprouting.Importantly,EC-specific deletion of Tecr loss restrictive quality of vascular permeability from neonatal stages to adulthood,with high levels of transcytosis,but maintains the vascular tight junctions.Moreover,lipidomic analysis shows that the expression of Tecr in ECs is associated with the containing of omega-3 fatty acids,which directly suppresses caveolae vesicles formation.These results reveal a protective role for Tecr in BBB integrity and suggest that Tecr as a novel therapeutic target in the central nervous system(CNS)diseases associated with BBB dysfunction.

2013~2017年中国空气质量改善与早产疾病负担改变

Preterm birth(PTB)is a leading cause of perinatal mortality and morbidity worldwide[1].Since maternal and fetal health protection has been included in the United Nations Sustainable Development Goals,identification of modifiable risk factors for PTB is particularly crucial.The Global Burden of Disease(GBD)Study 2019 recognized fine particulate matter(PM2.5)pollution as a risk factor for decreased gestational age and low birth weight.