Dynamics and genetic regulation of macronutrient concentrations during grain development in maize

Nitrogen(N), phosphorus(P), and potassium(K) are essential macronutrients that are crucial not only for maize growth and development, but also for crop yield and quality. The genetic basis of macronutrient dynamics and accumulation during grain filling in maize remains largely unknown. In this study, we evaluated grain N, P, and K concentrations in 206 recombinant inbred lines generated from a cross of DH1M and T877 at six time points after pollination. We then calculated conditional phenotypic values at different time intervals to explore the dynamic characteristics of the N, P, and K concentrations. Abundant phenotypic variations were observed in the concentrations and net changes of these nutrients. Unconditional quantitative trait locus(QTL) mapping revealed 41 non-redundant QTLs, including 17, 16, and 14 for the N, P, and K concentrations, respectively. Conditional QTL mapping uncovered 39 non-redundant QTLs related to net changes in the N, P, and K concentrations. By combining QTL, gene expression, co-expression analysis, and comparative genomic data, we identified 44, 36, and 44 candidate genes for the N, P, and K concentrations, respectively, including GRMZM2G371058 encoding a Doftype zinc finger DNA-binding family protein, which was associated with the N concentration, and GRMZM2G113967encoding a CBL-interacting protein kinase, which was related to the K concentration. The results deepen our understanding of the genetic factors controlling N, P, and K accumulation during maize grain development and provide valuable genes for the genetic improvement of nutrient concentrations in maize.

27-Hydroxycholesterol/liver X receptor/apolipoprotein E mediates zearalenone-induced intestinal immunosuppression:A key target potentially linking zearalenone and cancer

Zearalenone(ZEN)is a mycotoxin that extensively contaminates food and feed,posing a significant threat to public health.However,the mechanisms behind ZEN-induced intestinal immunotoxicity remain unclear.In this study,Sprague-Dawley(SD)rats were exposed to ZEN at a dosage of 5 mg/kg/day b.w.for a duration of 14 days.The results demonstrated that ZEN exposure led to notable pathological alterations and immunosuppression within the intestine.Furthermore,ZEN exposure caused a significant reduction in the levels of apolipoprotein E(ApoE)and liver X receptor(LXR)(P<0.05).Conversely,it upregulated the levels of myeloid-derived suppressor cells(MDSCs)markers(P<0.05)and decreased the presence of 27-hydroxycholesterol(27-HC)in the intestine(P<0.05).It was observed that ApoE or LXR agonists were able to mitigate the immunosuppressive effects induced by ZEN.Additionally,a bioinformatics analysis highlighted that the downregulation of ApoE might elevate the susceptibility to colorectal,breast,and lung cancers.These findings underscore the crucial role of the 27-HC/LXR/ApoE axis disruption in ZEN-induced MDSCs proliferation and subsequent inhibition of T lymphocyte activation within the rat intestine.Notably,ApoE may emerge as a pivotal target linking ZEN exposure to cancer development.

Combining QTL Mapping and Multi-Omics Identify Candidate Genes for Nutritional Quality Traits during Grain Filling Stage in Maize

The nutritional composition and overall quality of maize kernels are largely determined by the key chemical com-ponents:protein,oil,and starch.Nevertheless,the genetic basis underlying these nutritional quality traits during grainfilling remains poorly understood.In this study,the concentrations of protein,oil,and starch were studied in 204 recombinant inbred lines resulting from a cross between DH1M and T877 at four different stages post-pollination.All the traits exhibited considerable phenotypic variation.During the grain-filling stage,the levels of protein and starch content generally increased,whereas oil content decreased,with significant changes observed between 30 and 40 days after pollination.Quantitative trait locus(QTL)mapping was conducted and a total of 32 QTLs,comprising 14,12,and 6 QTLs for grain protein,oil,and starch content were detected,respectively.Few QTLs were consistently detectable across different time points.By integrating QTL analysis,glo-bal gene expression profiling,and comparative genomics,we identified 157,86,and 54 differentially expressed genes harboring nonsynonymous substitutions between the parental lines for grain protein,oil,and starch con-tent,respectively.Subsequent gene function annotation prioritized 15 candidate genes potentially involved in reg-ulating grain quality traits,including those encoding transcription factors(NAC,MADS-box,bZIP,and MYB),cell wall invertase,cellulose-synthase-like protein,cell division cycle protein,trehalase,auxin-responsive factor,and phloem protein 2-A13.Our study offers significant insights into the genetic architecture of maize kernel nutritional quality and identifies promising QTLs and candidate genes,which are crucial for the genetic enhance-ment of these traits in maize breeding programs.

Similarity between seed rain and neighbouring mature tree communities in an old-growth temperate forest

Seed distribution and deposition patterns around parent trees are strongly aff ected by functional traits and therefore infl uence the development of plant communities.To assess the limitations of seed dispersal and the extent to which diaspore and neighbouring parental traits explain seed rain,we used a 9-year seed data set based on 150 seed traps in a 25-ha area of a temperate forest in the Changbai Mountain.Among 480,598 seeds belonging to 12 families,17 genera,and 26 species were identifi ed,only 54%of the species with mature trees in the community were represented in seeds collected over the 9 years,indicating a limitation in seed dispersal.Understory species were most limited;overstory species were least limited.Species with wind-dispersed seed had the least limitation,while the lowest similarity in species richness was for animal-dispersed species followed by gravity-dispersed species;fl eshy-fruited species had stronger dispersal limitations than dry-fruited species.Generalized linear mixed models showed that relative basal area had a signifi cant positive eff ect on seed abundance in traps,while the contribution of diaspore traits was low for nearly all groups.These results suggest that tree traits had the strongest contribution to seed dispersal and deposition for all functional groups examined here.These fi ndings strengthen the knowledge that tree traits are key in explaining seed deposition patterns,at least at the primary dispersal stage.This improved knowledge of sources of seeds that are dispersed could facilitate greater understanding of seedling and community dynamics in temperate forests.

Stay in touch with the endoplasmic reticulum

The endoplasmic reticulum(ER),which is composed of a continuous network of tubules and sheets,forms the most widely distributed membrane system in eukaryotic cells.As a result,it engages a variety of organelles by establishing membrane contact sites(MCSs).These contacts regulate organelle positioning and remodeling,including fusion and fission,facilitate precise lipid exchange,and couple vital signaling events.Here,we systematically review recent advances and converging themes on ER-involved organellar contact.The molecular basis,cellular influence,and potential physiological functions for ER/nuclear envelope contacts with mitochondria,Golgi,endosomes,lysosomes,lipid droplets,autophagosomes,and plasma membrane are summarized.

Safety and efficiency of stem cell therapy for COVID-19:a systematic review and meta-analysis

Background:With the COVID-19 pandemic continuing,various treatments have become widely practiced.Stem cells have a wide range of applications in the treatment of lung diseases and have therefore been experimentally used to treat patients with COVID-19,but whether the expanded use of stem cells is safe and reliable still lacks enough evidence.To address this issue,we systematically reviewed the safety and efficiency of stem cell therapy in COVID-19 cases.Methods:We searched PubMed,Embase,Web of Science,The Cochrane Library,CNKI,WanFang,VIP and SinoMed up to January 18,2022.The included studies were assessed using the Risk-of-bias tool 1.0 and MINORS instrument.The adverse events,mortality,length of hospital day and laboratory parameters were analyzed by meta-analysis.We adhered to PRISMA reporting guideline.Results:We have included 17 studies meeting the inclusion data.There were no significant differences in AEs(OR=0·39,95%CI=0·12 to 1·33,P=0·13,I^(2)=58%)and SAEs(OR=0·21,95%CI=0·04 to 1·03,P=0·05,I^(2)=0%)between stem cell therapy group and control group.The analysis showed that stem cell treatment could significantly reduce the mortality rate(OR=0·24,95%CI=0·13 to 0·45,P<0·01,I^(2)=0%),but was not able to cause changes in length of hospital stay or most laboratory parameters.Conclusions:The present study shows that stem cell therapy for COVID-19 has a remarkable effect on efficiency without increasing risks of adverse events and length of hospital stay.It is potentially necessary to establish the criteria for COVID-19 for stem cell therapy.

新型樟脑磺胺基肟醚衍生物的合成及抗肿瘤活性研究

利用药物设计中的活性拼接原理,以(+)-10-樟脑磺酸为原料,经酰氯化、酰胺化和缩合反应,设计合成了一系列樟脑磺胺基肟醚类衍生物,通过1HNMR、13CNMR和HRMS对其结构进行了表征.采用噻唑蓝(MTT)法对目标化合物对人肺腺癌细胞(A549)、人宫颈癌细胞(Hela)、人乳腺癌细胞(MCF-7)和人正常胚胎肝细胞(LO2)进行抗肿瘤活性评价。结果表明,大部分化合物显示出良好的抗肿瘤活性。其中,(+)-1-(7,7-二甲基-2-(苄氧基亚氨基)双环[2.2.1]庚烷-1-基)-N-(3-(三氟甲基)苯基)甲磺酰胺(4r)对三种细胞表现出最好的抗增值效果,IC50值分别为6.75、7.93和4.51μmol·L^(-1).采用流式细胞术检测细胞周期和凋亡,Hoechst染色观察细胞形态变化.荧光探针DCFH-DA和JC-1分别用于检测细胞内活性氧水平和线粒体膜电位.初步机理研究表明,化合物4r可将MCF-7细胞阻滞在G0/G1期,可诱导活性氧产生和线粒体膜电位崩溃进而诱导细胞呈剂量依赖式凋亡.

Pathological and molecular examinations of postmortem testis biopsies reveal SARS-CoV-2 infection in the testis and spermatogenesis damage in COVID-19 patients

In late December 2019,the novel severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),which causes coronavirus disease 2019(COVID-19),was identified in Wuhan,China,and the ensuing pandemic has led to more than 50 million infected individuals and more than one million deaths by November 10,2020(https://covid19.who.int/).Pathologic investigations of autopsy tissue have focused primarily on the lung,heart,and kidney,whereas morphologic data on testis injury and the effects of SARS-CoV-2 infection on spermatogenesis are limited.Although two groups did not detect SARS-CoV-2 in the semen or testes of recovered COVID-19 patients,1,2 another group confirmed SARS-CoV-2 in the semen of patients.3 Therefore,it is currently unknown whether SARS-CoV-2 infection impacts spermatogenesis and male fertility.In the present study,we evaluated the effects of SARS-CoV-2 infection on spermatogenesis by examining the pathophysiology and molecular features of testes obtained from five male COVID-19 patients at autopsy.

被子植物性系统的多样性、生态功能及分布规律

性系统是被子植物繁育系统的核心,决定着植物种群的遗传特征、进化方向与速度,在种群动态、群落结构及生态系统的构建与维持中具有重要意义。本文回顾了被子植物性系统的发展历程及研究方向,总结了近30年基于性系统研究的前沿科学问题,包括性系统的多样性和进化、与其他功能性状的生态关联、沿环境梯度的分布格局及变化规律、与群落物种共存机制和群落动态的关系及其对干扰的响应。尽管有关植物性系统的研究已经延伸到生态学领域的诸多方面,有力地推动了各方面的发展,但仍有很多值得关注和需要着重研究的方向和问题。本文对未来基于植物性系统的研究方向等提出了展望,并指出,在当前全球气候变化背景下,性系统可作为重要的功能性状应用于指导生物多样性保护和生态系统管理政策的制定。

Co-delivery of luteolin and TGF-β1 plasmids with ROS-responsive virus-inspired nanoparticles for microenvironment regulation and chemo-gene therapy of intervertebral disc degeneration

Intervertebral disc degeneration(IDD)is closely related to inflammation and imbalance of synthesis/catabolism of extracellular matrix(ECM)in intervertebral disc(IVD).Considering this,luteolin(LUT),a kind of natural flavonoid with good anti-inflammatory effect and TGF-β1(a gene that promotes the regeneration of ECM)plasmid was co-loaded and co-delivered to nucleus pulposus cells(NPCs).Reactive oxygen species(ROS)responsive cationic copolymer,poly(β-amino ester)-poly(ε-caprolactone)(PBC),with high plasmid DNA(pDNA)compression affinity was synthesized.It can self-assemble into nano-sized polyplexes(pDNA@PBC)with virus-inspired structure and function through which it can transfect pDNA into NPCs with very high efficiency and negligible cytotoxicity.LUT was encapsulated in the hydrophobic core of pDNA@PBC.The co-delivery system,LUT-pTGFβ1@PBC,could enhance the cellular uptake of NPCs and manifest excellent sustained drug release in IVD.Real time quantitative polymerase chain reaction(RT-qPCR)and Western blot experiments reveal that the co-delivery system could inhibit inflammation in NPCs and restore the balance of anabolism and catabolism in vitro by activating TGF/SMAD3 and inhibiting NFkB/p65.Moreover,LUT-pTGF-β1@PBC retards IDD in vivo as detected by radiological and histological methods with good biosafety in rats.LUT-pTGF-β1@PBC may be a promising option for the treatment of IDD.

Self-corrected unsupervised domain adaptation

Unsupervised domain adaptation(UDA),which aims to use knowledge from a label-rich source domain to help learn unlabeled target domain,has recently attracted much attention.UDA methods mainly concentrate on source classification and distribution alignment between domains to expect the correct target prediction.While in this paper,we attempt to learn the target prediction end to end directly,and develop a Self-corrected unsupervised domain adaptation(SCUDA)method with probabilistic label correction.SCUDA adopts a probabilistic label corrector to learn and correct the target labels directly.Specifically,besides model parameters,those target pseudo-labels are also updated in learning and corrected by the anchor-variable,which preserves the class candidates for samples.Experiments on real datasets show the competitiveness of SCUDA.

Pointwise manifold regularization for semi-supervised learning

Manifold regularization(MR)provides a powerful framework for semi-supervised classification using both the labeled and unlabeled data.It constrains that similar instances over the manifold graph should share similar classification out-puts according to the manifold assumption.It is easily noted that MR is built on the pairwise smoothness over the manifold graph,i.e.,the smoothness constraint is implemented over all instance pairs and actually considers each instance pair as a single operand.However,the smoothness can be pointwise in nature,that is,the smoothness shall inherently occur“everywhere"to relate the behavior of each point or instance to that of its close neighbors.Thus in this paper,we attempt to de-velop a pointwise MR(PW_MR for short)for semi-supervised learning through constraining on individual local instances.In this way,the pointwise nature of smoothness is preserved,and moreover,by considering individual instances rather than instance pairs,the importance or contribution of individual instances can be introduced.Such importance can be described by the confidence for correct prediction,or the local density,for example.PW.MR provides a different way for implementing manifold smoothness Finally,empirical results show the competitiveness of PW_MR compared to pairwise MR.

A maximum margin clustering algorithm based on indefinite kernels

Indefinite kernels have attracted more and more attentions in machine learning due to its wider application scope than usual positive definite kernels. However, the research about indefinite kernel clustering is relatively scarce. Furthermore, existing clustering methods are mainly designed based on positive definite kernels which are incapable in indefinite kernel scenarios. In this paper, we propose a novel indefinite kernel clustering algorithm termed as indefinite kernel maximum margin clustering (IKMMC) based on the state-of-the-art maximum margin clustering (MMC) model. IKMMC tries to find a proxy positive definite kernel to approximate the original indefinite one and thus embeds a new F-norm regularizer in the objective function to measure the diversity of the two kernels, which can be further optimized by an iterative approach. Concretely, at each iteration, given a set of initial class labels, IKMMC firstly transforms the clustering problem into a classification one solved by indefinite kernel support vector machine (IKSVM) with an extra class balance constraint and then the obtained prediction labels will be used as the new input class labels at next iteration until the error rate of prediction is smaller than a prespecified tolerance. Finally, IKMMC utilizes the prediction labels at the last iteration as the expected indices of clusters.Moreover, we further extend IKMMC from binary clustering problems to more complex multi-class scenarios. Experimental results have shown the superiority of our algorithms.

A primal perspective for indefinite kernel SVM problem

Indefinite kernel support vector machine(IKSVM)has recently attracted increasing attentions in machine learning.Since IKSVM essentially is a non-convex problem,existing algorithms either change the spectrum of indefinite kernel directly but risking losing some valuable information or solve the dual form of IKSVM whereas suffering from a dual gap problem.In this paper,we propose a primal perspective for solving the problem.That is,we directly focus on the primal form of IKSVM and present a novel algorithm termed as IKSVM-DC for binary and multi-class classification.Concretely,according to the characteristics of the spectrum for the indefinite kernel matrix,IKSVM-DC decomposes the primal function into the subtraction of two convex functions as a difference of convex functions(DC)programming.To accelerate convergence rate,IKSVM-DC combines the classical DC algorithm with a line search step along the descent direction at each iteration.Furthermore,we construct a multi-class IKSVM model which can classify multiple classes in a unified form.A theoretical analysis is then presented to validate that IKSVM-DC can converge to a local minimum.Finally,we conduct experiments on both binary and multi-class datasets and the experimental results show that IKSVM-DC is superior to other state-of-the-art IKSVM algorithms.

SARS-CoV-2 infection induces testicular injury in Rhesus macaque

Dear Editor,COVID-19 is caused by the severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),which is the seventh coronavirus known to infect humans.The COVID-19 pandemic has spread to more than 200countries,with more than 600 million confirmed cases and over 6.5million deaths as of September 2022,posing a huge challenge to global public health.

Recent advances in the study of sepsis-induced depression

Progress in medicine such as the use of anti-infective drugs and development of the advanced life support equipment has greatly improved the survival rate of patients with sepsis.However,the incidence of sepsis-relateddiseases is increasing.These include severe neurologic and psychologic disorders,cognitive decline,anxiety,depression,and post-traumatic stress disorder.Cerebral dysfunction occurs via multiple interacting mechanisms,with different causative pathogens having distinct effects.Because sepsis-related diseases place a substantial burden on patients and their families,it is important to elucidate the underlying pathophysiologic mechanisms todevelop effective treatments.

Advances in the knowledge on the role of apoptosis repressor with caspase recruitment domain in hemorrhagic stroke

The apoptosis repressor with caspase recruitment domain(ARC)plays a critical role in extrinsic apoptosis initiation via death receptor ligands,physiological stress,infection response in a tissue-dependent manner,endoplasmic reticulum(ER)stress,genotoxic drugs,ionizing radiation,oxidative stress,and hypoxia.Recent studies have suggested that regulating apoptosis-related pathways can improve outcomes for patients with neurological diseases,such as hemorrhagic stroke.ARC expression is significantly correlated with acute cerebral hemorrhage.However,the mechanism by which it mediates the anti-apoptosis pathway remains poorly known.Here,we discuss the function of ARC in hemorrhagic stroke and argue that it could serve as an effective target for the treatment of hemorrhagic stroke.

0.05%阿托品联合角膜塑形镜在进展性近视中对离焦环的调控增效作用

目的:研究0.05%阿托品在配戴角膜塑形镜的进展性近视中对离焦环调控的增效作用。方法:前瞻性随机对照研究。随机选取2021年6月至2023年1月在重庆渥迪眼科配戴角膜塑形镜后监测1年眼轴仍增加0.34 mm的进行性近视患者90例(90眼),按照自愿原则随机分为2组。对照组45眼,采用角膜塑形镜联合0.01%阿托品眼液治疗;联合组45眼,采用角膜塑形镜联合0.05%阿托品眼液治疗。治疗前和治疗1年后测定患者的眼轴、亮瞳直径、暗瞳直径、亮瞳下离焦环与瞳孔的相对位置关系(分为离焦环大于瞳孔、离焦环等于瞳孔、离焦环小于瞳孔)以及不良反应发生情况。采用t检验和卡方检验进行2组间的分析。结果:与治疗前相比,对照组和联合组在1年的治疗后眼轴均显著增加(P<0.001),且联合组眼轴增加明显低于对照组(P<0.001)。治疗后联合组和对照组亮瞳和暗瞳直径与治疗前相比均显著增加(P<0.001)。治疗后,联合组和对照组亮瞳下离焦环与瞳孔的相对位置关系与治疗前比较均有改变,联合组差异有统计学意义(P=0.001),对照组差异无统计学意义(P>0.05)。治疗期间,联合组和对照组不良反应发生情况比较差异无统计学意义(P>0.05)。结论:角膜塑形镜联合0.01%、0.05%阿托品可协同增强青少年的近视控制效果,并具有良好的安全性。0.05%阿托品联合角膜塑形镜对进展性近视的控制效果更佳。

A case of ischemic-hypoxic encephalopathy due to oral succinylcholine ingestion

Dear Editor,Cases of succinylcholine poisoning are rarely seen in clinic,and severe brain damage due to ingestion of succinylcholine is even rarer.Here,we report on a patient who poisoned herself via oral ingestion of succinylcholine,discuss the clinical characteristics,pathogenesis,and treatment of the succinylcholine-related ischemic-hypoxic encephalopathy that this patient suffered,and review the relevant literature.This study aimed to improve clinicians'understanding of ischemic-hypoxic encephalopathy due to succinylcholine chloride toxicity.