High-efficiency 3D cell spheroid formation via the inertial focusing effect in rotating droplets

The three-dimensional(3D)spheroid culture has been widely used as an important tool in biological research.Although several techniques have been established to prepare cell spheroids,fast and controllable production remains one of the major challenges.In this study,a simple but efficient method utilizing the inertial focusing effect in rotating hanging droplets is demonstrated for the rapid and controllable production of cell spheroids.

A molecular toolkit to boost functional genomic studies in transformation-recalcitrant vegetable legumes

Dear Editor Legumes,the second-largest family of crops,contribute over one-third of human dietary proteins.Soybean(Glycine max L.),common bean(Phaseolus vulgaris L.),pea(Pisum sativum L.),and cowpea(Vigna unguiculata L.)are among the most widely culti-vated crop legumes for grain and vegetable and are essential for food security globally.

Solvent Effects on the UV Absorption Spectrum of Carmofur

In this article, we reported that carmofur could be induced by some solvent to produce conformational alteration. Ultraviolet (UV) spectra were used to study the conformation alteration of carmofur. Upon the addition of acid in the some solvent, UV spectroscopy of carmofur could change gradually. When base was added to this system, UV spectroscopy of carmofur could return to the original state, and the change process was reversible. The variable temperature 1H and 13C-NMR spectrum were used to testify that temperature did not have any effect on the conformation alteration of carmofur in Acetonitrile: Trifluoroacetic-acid (9:1). These two conformers of carmofur were structurally stable in Acetonitrile: Trifluoroacetic-acid (9:1).

Determination of Meclofenoxate Content in Meclofenoxate Hydrochloride for Injection by DSC and 1H-NMR

Two simple and rapid analytical methods (DSC and 1H-NMR), are proposed for determination of meclofenoxate in meclofenoxate hydrochloride for injection. DSC thermogram is recorded without any sample pretreatment. The response linearity is ensured by linear determination factors R2, which is 0.9982. The recoveries of meclofenoxate hydrochloride in sterile powder for injection are from 98.3% to 102.3% (n = 3). The quantitative 1H-NMR is quick and simple to use. The quantitation of meclofenoxate is reproducible and the relative standard deviation is 1.0%. The accuracy of two methods is validated by comparison with the results obtained by HPLC. The results show that the two methods are capable of quantifying the content of meclofenoxate in meclofenoxate hydrochloride for injection.

Identification of two novel mutations in the GALNT3 gene in a Chinese family with hyperphosphatemic familial tumoral calcinosis

Hyperphosphatemic familial tumoral calcinosis(HFTC) is a rare, autosomal recessive genetic disease.This disease is characterized by the progressive calcification of soft tissues leading to symptoms of pressure and hyperphosphatemia but normal concentrations of serum calcium with or without an elevation of1,25-dihydroxyvitamin D3 levels.HFTC is caused by loss-of-function mutations in the GALNT3, FGF23 or KL genes. Here, we identified two novel mutations in the GALNT3 gene in a Chinese family with HFTC.Identification of a novel genotype in HFTC provides clues for understanding the phenotype–genotype relationships in HFTC and may assist not only in the clinical diagnosis of HFTC but also in the interpretation of the genetic information used for prenatal diagnosis and genetic counseling.

QTL mapping of adult plant resistance to stripe rust and leaf rust in a Fuyu 3/Zhengzhou 5389 wheat population

Stripe or yellow rust(YR)and leaf rust(LR)cause large losses in wheat production worldwide.Resistant cultivars curtail the levels of losses.The present study aimed to identify quantitative trait loci(QTL)for YR and LR resistance in 147 F2:6 recombinant inbred lines(RIL)derived from the cross Fuyu 3/Zhengzhou 5389.The RIL population and parents were genotyped with the Wheat55 K single nucleotide polymorphism(SNP)array and simple sequence repeat(SSR)markers.All materials were also phenotyped for YR severity at Mianyang in Sichuan province and Baoding in Hebei province in the 2015/2016,2016/2017,and 2017/2018 cropping seasons,and LR severity at Zhoukou in Henan province and at Baoding in 2017/2018.Eleven QTL for YR resistance and five for LR resistance were detected using inclusive composite interval mapping(Ici Mapping).Four of these QTL on chromosomes 1 BL,2 BS,3 AL,and 5 AL conferred resistance to both YR and LR.The QTL on 1 BL was Lr46/Yr29,and that on 7 BL might be Lr68.The QTL on chromosome 2 BS was detected at a similar position to previously detected loci.QYr.hebau-3 AL/QLr.hebau-3 AL,QYr.hebau-5 AL/QLr.hebau-5 AL,QYr.hebau-7 DL,QYr.hebau-4 BS,QYr.hebau-6 DL,and QYr.hebau-2 AS are likely to be new.An SSR marker for QYr.hebau-7 DL was developed and validated in a diverse wheat panel from China,suggesting effectiveness in different genetic backgrounds.These QTL with closely linked SNP and SSR markers could be useful for marker-assisted selection in wheat breeding programs targeting durable resistance to both diseases.

Fischer–Tropsch synthesis on impregnated cobalt-based catalysts:New insights into the effect of impregnation solutions and pH value

The Co-based catalysts were prepared with different cobalt acetate solutions. Effects of pH value were studied deeply on Fischer–Tropsch synthesis (FTS) through a semi-batch reactor. Among all impregnation solutions (water, butanol, amyl alcohol, acetic acid, nitric acid and ammonium nitrate), the catalyst prepared by NH4NO3solution showed the highest catalytic activity due to its small particle size and high reduction degree. However, the catalyst with the smallest particle size derived from water as impregnation solution exhibited low activity as well as high methane selectivity since it was difficult to be reduced and inactive in FTS. According to FT-IR spectra results, the low intensity of absorbed CO on the catalyst prepared from water solution resulted in low FTS activity. Whereas, the high activity of catalysts prepared from NH4NO3solution could be explained by the high intensity of absorbed CO on the catalysts. The cobalt species on the catalysts prepared under lower pH conditions exhibited smaller particle size distribution as well as lower CO conversion than those prepared at higher pH value. ? 2016 Science Press

An AFLP marker linked to the leaf rust resistanc gene LrBi16 and test of allelism with Lr14a on chromosome arm 7BL

Leaf rust(LR), caused by Puccinia triticina, is one of the most widespread diseases of common wheat(Triticum aestivum L.) worldwide. The LR resistance gene Lr Bi16 has been mapped on chromosome arm 7BL in Chinese wheat cultivar Bimai 16 and was closely linked to SSR loci Xcfa2257 and Xgwm344 with genetic distances of 2.8 c M and 2.9 c M, respectively. In the present study, a total of 304 AFLP primer pairs were used to screen Bimai 16 and Thatcher and resistant and susceptible DNA bulks. The polymorphic AFLP marker P-ATT/M-CGC173 bp was used to genotype F2 and F3populations to identify markers more closely linked to Lr Bi16. Marker P-ATT/M-CGC173 bp was tightly linked to Lr Bi16 with a genetic distance of0.5 c M. As Lr Bi16 was mapped near the Lr14 a locus, 809 F2 plants from the Bimai 16/RL6013(Lr14a) cross were inoculated with the Pt pathotype FHNQ to test the allelism of Lr14 a and Lr Bi16. All of the F2 plants were resistant to FHNQ(IT between; and 2), suggesting that Lr14 a and Lr Bi16 are allelic.

Anthrax lethal toxin and tumor necrosis factor-a synergize on intestinal epithelia to induce mouse death

Bacillus anthracis lethal toxin(LT)is a determinant of lethal anthrax.Its function in myeloid cells is required for bacterial dissemination,and LT itself can directly trigger dysfunction of the cardiovascular system.The interplay between LT and the host responses is important in the pathogenesis,but our knowledge on this interplay remains limited.Tumor necrosis factor-a(TNF-a)is a pleiotropic pro-inflammatory cytokine induced by bacterial infections.Since LT accumulates and cytokines,predominantly TNF,amass during B.anthracis infection,co-treatment of TNF+LT in mice was used to mimic in vivo conditions for LT to function in inflamed hosts.Bone marrow transplantation and genetically engineered mice showed unexpectedly that the death of intestinal epithelial cells(IECs)rather than that of hematopoietic cells led to LT+TNF-induced lethality.Inhibition of p38a mitogen-activated protein kinase(MAPK)signaling by LT in IECs promoted TNF-induced apoptosis and necroptosis of IECs,leading to intestinal damage and mouse death.Consistently,p38a inhibition by LT enhanced TNF-mediated cell death in human colon epithelial HT-29 cells.As intestinal damage is one of the leading causes of lethality in anthrax patients,the IEC damage caused by LT+TNF would most likely be a mechanism underneath this clinical manifestation and could be a target for interventions.

眼基线参数对角膜塑形镜设计及其临床效果的影响

角膜塑形镜作为减缓青少年近视快速增长的重要手段之一,被临床广泛认可。角膜塑形镜的参数设计对近视控制效果影响显著。笔者结合角膜塑形镜验配时所需依据的人眼基线参数,对角膜塑形镜镜片关键参数的选择及其相关临床效果进行述评,以期进一步加强验配者对镜片参数设计的认识和提升角膜塑形镜的近视控制效果,为深入开展青少年近视防控工作提供参考和指导。

3D ball-type self-assemble CeO_(2) nanostructure produced by facile hydrothermal strategy for catalytic wet air oxidation of N,N-dimethylformamide

CeO_(2)plays an important role in heterogeneous catalysis,and its performance is highly dependent on the oxygen vacancies and surface defects,which can be easily tuned by manipulating the particle dimensions and morphology.In this article,we report a facile strategy to synthesize a new type of CeO_(2)with modified surface property which can improve its ability to active oxygen.The obtained ball-type 3D selfassemble CeO_(2)(M-CeO_(2)) is composed of large amounts of small 1D crystals which are stro ngly connected with each other.Detailed characterizations confirm its morphology,particle size and improved reducibility with abundant fraction of Ce^(3+)and more surface active oxygen when compared with CeO_(2)-nanorods and CeO_(2)-nanocubes.In the catalytic wet air oxidation(CWAO)of N,N-dimethylfo rmamide,the total organic carbon(TOC)and total nitrogen(TN)conversion of M-CeO_(2)at 180℃in 3 h are 68%and 46%,respectively,which are higher than that of CeO_(2)-nanorods and CeO_(2)-nanocubes.Besides,M-CeO_(2) presents the lowest activation energy,which is related to its modified surface property.The good stability with consecutive four reactions of M-CeO_(2)in catalytic reactions suggests its potential application in CWAO processes for industrial wastewater treatment.

Influence of surface modification of SrFe12O19 particles with oleic acid on magnetic microsphere preparation

Oleic acid was used as surface modification agent to improve the hydrophobicity of magnetic strontium hexaferrite particles. The structure and properties of treated magnetic particles were characterized by scanning electronic microscopy （SEM）, Fourier transform infrared spectra （FTIR）, powder X-ray diffraction （XRD） and magnetic property measurement system （MPMS）. The results show that oleic acid is chemically enwrapped on the surface of SrFe12O19 particles. Magnetic particles modified by oleic acid are highly dispersible and strongly responsive to magnetism but with slight decrease in saturated magnetization. The affinity between magnetic particles and monomers is improved by surface modification, resulting in increased particle incorporation in magnetic polymeric microspheres. The surface modification mechanism of magnetic particles by oleic acid is addressed in this work.

Influence of channel/back-barrier thickness on the breakdown of AlGaN/GaN MIS-HEMTs

The leakage current and breakdown voltage of AlGaN/GaN/AlGaN high electron mobility transistors on silicon with different GaN channel thicknesses were investigated.The results showed that a thin GaN channel was beneficial for obtaining a high breakdown voltage,based on the leakage current path and the acceptor traps in the AlGaN back-barrier.The breakdown voltage of the device with an 800 nm-thick GaN channel was 926 V@1 m A/mm,and the leakage current increased slowly between 300 and 800 V.Besides,the raising conduction band edge of the GaN channel by the AlGaN back-barrier lead to little degradation for sheet 2-D electron gas density,especially,in the thin GaN channel.The transfer and output characteristics were not obviously deteriorated for the samples with different GaN channel thickness.Through optimizing the GaN channel thickness and designing the Al GaN back-barrier,the lower leakage current and higher breakdown voltage would be possible.

High-temperature wheat leaf rust resistance gene Lr13 exhibits pleiotropic effects on hybrid necrosis

Dear Editor,Wheat is one of the most important staple food crops.Leaf rust caused by Puccinia triticina Eriks.(Pt)is a destructive foliar disease that threatens world wheat production.Complementary wheat genes Necrosis 1(Ne1)and Necrosis 2(Ne2)on chromosome arms 5BL and 2BS,respectively,cause hybrid necrosis(Caldwell and Compton,1943;Chu et al.,2006).Ne2 shows extremely tight genetic linkage with leaf rust resistance gene Lr13(Zhang et al.,2016).We previously identified a temperature-sensitive leaf rust resistance gene LrZH22 in Chinese wheat cultivar Zhoumai 22(ZM,Figure 1A)that was effective against most Chinese Pt pathotypes(Wang et al.,2016)and shared an overlapping genetic interval with Lr13.In a separate study,a recessive early leaf senescence 1(els1)gene(Figure 1B)shared an overlapping interval with LrZH22/Lr13/Ne2(Chu et al.,2006;Wang et al.,2016;Zhang et al.,2016;Li et al.,2018).However,the function and relationship of LrZH22/Lr13/Ne2/els1 remained unknown for decades.Here,we report the map-based cloning of LrZH22 and els1 and characterize their relationship with Lr13 and Ne2 in conjunction with a companion paper(Hewitt et al.t 2021)studying the same gene.

基于线上自主学习和考核的标准切面强化培训在产科超声教学中的应用

目的探讨基于线上自主学习和考核的产科超声教学模式对规范化培训学员识别产科超声标准切面能力的效果。方法2021年3月纳入21名在北京协和医院超声医学科参加住院医师规范化培训的学员,应用调查问卷收集学员对产科超声的教学需求,以胎儿颅脑、胸腹腔和心脏3个部位的标准切面及标志性结构为培训内容录制讲课视频。学员通过线上自主学习形式,完成标准切面强化培训及考核。应用χ^(2)检验对比培训前后学员答题正确率的差异。结果大部分学员(95.2%,20/21)认为产科超声培训非常重要并且非常愿意参加;考核题目包含胎儿颅脑、胸腹腔、心脏3个部位标准切面的标志性结构识别共22题。培训前学员答题总正确率为79.9%(369/462),培训后学员答题总正确率提高为88.7%(410/462),其中,学员对心脏标志性结构识别的正确率提高11.5%(87.7%vs76.2%),培训前后答题正确率比较,差异具有统计学意义(χ^(2)=11.28,P=0.001)。结论基于线上自主学习和考核的标准切面强化培训,提高了规范化培训学员对胎儿颅脑、胸腹腔和心脏系统标准切面中标志性结构的识别能力,可作为产科超声培训的有效手段。

Turnover of dissolved organic carbon fuels nocturnal CO_(2) emissions from a headwater catchment reservoir, Southeastern China: Effects of ecosystem metabolism on source partitioning of CO2 emissions

Dam reservoirs in headwater catchments, as critical zones for their proximity to terrestrial sources, play important roles in dissolved organic carbon(DOC) cycling. However, the effects of ecosystem metabolism(EM) on DOC cycling are not well known. Here, in-situ diurnal and monthly observations were conducted to measure EM(including gross primary production(GPP), ecosystem respiration(ER) and heterotrophic respiration(HR)), DOC turnover and CO_(2)emissions in a headwater catchment reservoir in Southeastern China in 2020. Our study showed the nocturnal CO_(2)emission rate was about twice as high as in daytime, and was strongly driven by EM. The values for DOC turnover velocity ranged from 0.10 to 1.59 m/day,and the average DOC turnover rate was 0.13 day-1, with the average removal efficiency of 12%. The contribution of respired DOC to daily CO_(2)emissions ranged from 17% to 61%. The accumulated efficiencies were estimated to be 13% for the selected 15 reservoirs throughout the Changjiang River network, corresponding to about 0.34 Tg C/year of the respired DOC.The modified CO_(2)flux was 0.75 Tg C/year, and respired DOC accounted for about 45% of total emitted CO_(2)from the 15 larger reservoirs. Our research emphasizes the necessity of incorporating the effects of EM into studies of reservoir DOC removal and COemissions.

Caspase-1 and Gasdermin D Afford the Optimal Targets with Distinct Switching Strategies in NLRP1b Inflammasome-Induced Cell Death

Inflammasomes are essential complexes of innate immune system, which form the first line of host defense against pathogens. Mounting evidence accumulates that inflammasome signaling is highly correlated with coronavirus disease 2019 (COVID-19). However, there remains a significant gap in our understanding of the regulatory mechanism of inflammasome signaling. Combining mathematical modeling with experimental analysis of NLRP1b inflammasome signaling, we found that only the expression levels of caspase-1 and GSDMD have the potential to individually switch cell death modes. Reduction of caspase-1 or GSDMD switches cell death from pyroptosis to apoptosis. Caspase-1 and GSDMD present different thresholds and exert distinct pathway choices in switching death modes. Pyroptosis switches to apoptosis with an extremely low threshold level of caspase-1, but with a high threshold of GSDMD. Caspase-1-impaired cells employ ASC-caspase-8-dependent pathway for apoptosis, while GSDMD-impaired cells primarily utilize caspase-1-dependent pathway. Additionally, caspase-1 and GSDMD can severally ignite the cooccurrence of pyroptosis and apoptosis. Landscape topography unravels that the cooccurrence is dramatically different in caspase-1- and GSDMD-impaired cells. Besides pyroptosis state and apoptosis state, a potential new “coexisting” state in single cells is proposed when GSDMD acts as the driving force of the landscape. The “seesaw model” is therefore proposed, which can well describe the death states that are controlled by caspase-1 or GSDMD in single cells. Our study sheds new light on NLRP1b inflammasome signaling and uncovers the switching mechanisms among various death modes, providing potential clues to guide the development of more rational control strategies for diseases.

Facile synthesis of silicapolymer hybrids via simultaneous RAFT process and hydroxyl-alkoxysilane coupling reaction

This study aimed at the synthesis of silica particles grafted with better-defined homopolymers and block copolymers by tandem approach.Z-functionalized Sbenzyl S’-(3-trimethoxysilyl)propyltrithiocarbonate(BTPT)was used as a couplable RAFT agent to synthesize the target inorganic-organic hybrids.Simultaneous coupling reaction and RAFT process using silica particles and BTPT as raw materials efficiently afforded homopolymers grafted silica,and RAFTsynthesized macro chain transfer agents withω-terminal trimethoxysilane moiety were utilized to mediate graft reaction to prepare silica particles grafted with di-,tri-and tetrablock copolymers comprised of polymer segments such as polystyrene,polyacrylamides and polyacrylates.When the grafted chains had molecular weights ranging between 3920 and 24800 g/mol,the molar grafting ratios,which were dependent on reaction conditions and types and compositions of grafted chains,were estimated to be in the range of 15.2–101μmol/g,and grafted polymers usually had polydispersity indices lower than 1.3,revealing that the grafting process was almost controllable.To the best of our knowledge,this versatile tandem approach is one of the most facile techniques to prepare silica particles grafted with polymeric chains with controlled molecular weight,low polydispersity and precise composition due to its minimal reaction steps,mild conditions,straightforward synthesis and satisfactory controllability.