烟草糖苷水解酶GH3基因家族鉴定与表达分析

糖苷水解酶GH3基因家族在植物的糖代谢和生长发育中起着重要作用,而烟草GH3基因家族目前尚未见相关鉴定和分析研究报道。本研究采用生物信息学方法在烟草基因组中鉴定GH3家族基因,并对其在不同组织中及逆境条件下的表达模式进行了分析。结果表明,在普通烟草K326的基因组中共鉴定出35个GH3基因,其中23个被定位在14条染色体上,存在6对共线性基因;GH3家族蛋白均为热稳定性蛋白,其基因上游启动子区均包含多个激素和胁迫响应元件。转录组数据表明,GH3家族基因大多数在烟苗茎尖高表达,少部分在根和茎中高表达,表达量受光照时间影响;烟苗受到干旱胁迫后GH3家族成员都有不同程度的响应。挑选4个NtGH3基因进行qRT-PCR分析,结果表明,NtGH3-5、NtGH3-19、NtGH3-22、NtGH3-26可能参与响应低温以及ABA处理。这可为深入了解烟草GH3基因家族及其功能提供依据。

New Interpretation of Neonatal Outcomes by Phenotypically Classified Preterm Syndrome:A Retrospective Cohort Study

Objective:The global aim to lower preterm birth rates has been hampered by the insufficient and incomplete understanding of its etiology,classification,and diagnosis.This study was designed to evaluate the association of phenotypically classified preterm syndromes with neonatal outcomes;to what extent would these outcomes be modified after the obstetric interventions,including use of glucocorticoid,magnesium sulfate,and progesterone.Methods:This was a retrospective cohort study conducted at Tongji Hospital(composed of Main Branch,Optical Valley Branch and Sino-French New City Branch)in Wuhan.A total of 900 pregnant women and 1064 neonates were retrospectively enrolled.The outcomes were the distribution of different phenotypes among parturition signs and pathway to delivery,the association of phenotypically classified clusters with short-term unfavorable neonatal outcomes,and to what extent these outcomes could be modified by obstetric interventions.Results:Eight clusters were identified using two-step cluster analysis,including premature rupture of fetal membranes(PPROM)phenotype,abnormal amniotic fluid(AF)phenotype,placenta previa phenotype,mixed condition phenotype,fetal distress phenotype,preeclampsia-eclampsia&hemolysis,elevated liver enzymes,and low platelets syndrome(PE-E&HELLP)phenotype,multiple fetus phenotype,and no main condition phenotype.Except for no main condition phenotype,the other phenotypes were associated with one or more complications,which conforms to the clinical practice.Compared with no main condition phenotype,some phenotypes were significantly associated with short-term adverse neonatal outcomes.Abnormal AF phenotype,mixed condition phenotype,PE-E&HELLP phenotype,and multiple fetus phenotype were risk factors for neonatal small-for gestation age(SGA);placenta previa phenotype was not associated with adverse outcomes except low APGAR score being 0-7 at one min;mixed condition phenotype was associated with low APGAR scores,SGA,mechanical ventilation,and gradeⅢ-Ⅳintraventricular hemorrhage(IVH);fetal distress phenotype was frequently associated with neonatal SGA and mechanical ventilation;PE-E&HELLP phenotype was correlated with low APGAR score being 0-7 at one min,SGA and neonatal intensive care unit(NICU)admission;multiple fetus phenotype was not a risk factor for the outcomes included except for SGA.Not all neonates benefited from obstetric interventions included in this study.Conclusion:Our research disclosed the independent risk of different preterm phenotypes for adverse pregnancy outcomes.This study is devoted to putting forward the paradigm of classifying preterm birth phenotypically,with the ultimate purpose of defining preterm phenotypes based on multi-center studies and diving into the underlying mechanisms.

A Participant-assigned Interventional Research of Precesarean Internal Iliac Artery Balloon Catheterization for Managing Intraoperative Hemorrhage of Placenta Previa and Placenta Accreta Spectrum Disorders After Cesarean Section

Placenta accreta spectrum disorder (PASD) and placenta previa (PP) are two of the mosthideous obstetric complications which are usually associated with a history of cesarean section(CS). Moreover, women with PASD, PP and/or a cesarean scarred uterus are more likely to haveadverse pregnancy outcomes, including blood transfusion, hysterectomy, pelvic organs damage,postpartum hemorhage, disseminated intravascular coagulation, multi-organ dysfunction syndromeand even maternal or fetal death. This study aimed to investigate the efficacy of precesareaninternal iliac artery balloon catheterization (BC) for managing severe hemorhage caused by PASDand PP with a history of CS. This participant-assigned interventional study was conducted inTongji Hospital. We recruited 128 women with suspected PASD, PP and a history of CS. Womenin the BC group accepted precesarean BC of bilateral internal iliac arteries before the scheduledcesarean delivery. Women in the control group underwent a conventional cesarean delivery.Intraoperative hemorrhage, transfusion volume, radiation dose, exposure time, complicationsand neonatal outcomes were discussed. There were significant differences in calculated bloodloss (CBL) between BC group and control group (1015.0±144.9 vs. 1467.0±171.0 mL, P=0.04).Precesarean BC could reduce intraoperative red blood cell (RBC) transfusion as compared withcontrol group (799.5±136.1 vs. 1286.0±161.6 mL, P=0.02) and lessen the rate of using bloodproducts (57.1% vs. 76.4%, P=0.02). The incidence of hysterectomy was also lower in BC groupthan in control group. Postpartum outcomes showed no significant differences between the twogroups, except that postoperation hospitalization was longer in BC group than in control group(6.7±0.4 vs. 5.8±0.2 days, P=0.03). Precesarean BC of internal iliac artery is an effective methodfor managing severe hemorrhage caused by PASD and PP with a cesarean scarred uterus, as it couldreduce intraoperative blood loss, lessen intraoperative RBC transfusions and potentially decreasehysterectomies.

外场强化电解水析氢

电解水析氢过程中的能量消耗及析氢效率有很多影响因素,其中,电荷转移电阻和催化剂表面气泡覆盖率是最为重要的两个因素。研究发现,在电解水析氢过程中利用外场进行强化,可以有效减小电荷转移电阻和催化剂表面气泡覆盖率,如温度场能为反应过程中电荷的转移注入能量,从而降低电荷转移电阻,降低过电位;而电场能直接调整催化剂电子结构或诱导电解液离子重新分布,从而促进界面电荷转移;光场则可以诱导水分子极化,增大剩余电场,同时拉伸水分子中氢键,有利于水分解产生氢气和氧气。因此,在电解池中引入温度场、磁场、超声场、电场、超重力场和光场等外场也是降低能耗、提高析氢效率的有效策略。近年来,关于外场强化电解水的研究工作虽有报道,但研究偏少且未见系统性的归纳总结。本文即综述了近年来在电解水析氢过程中利用外场强化的研究进展。介绍各种外场强化电解水析氢的基本原理,同时通过实验案例分析各外场手段的效果,并总结外场强化电解水析氢面临的挑战及发展方向。

Crack Types, Mechanisms, and Suppression Methods during High-energy Beam Additive Manufacturing of Nickel-based Superalloys: A Review

Nickel-based superalloys have been widely used in aerospace fields,especially for engine hot-end parts,because of their excellent high-temperature resistance.However,they are difficult to machine and process because of their special properties.High-energy beam additive manufacturing(HEB-AM)of nickel-based superalloys has shown great application potential in aerospace and other fields.However,HEB-AM of nickel-based superalloys faces serious cracking problems because of the unique characteristics of superalloys,and this has become the most significant bottleneck restricting their application.In this review,the current research status related to the types,formation mechanisms,and suppression methods of cracks in nickel-based superalloys produced by HEB-AM is described.The initiation and propagation mechanisms of cracks and their multiple influencing factors are also analyzed and discussed.Then,several possible research directions to solve the cracking problems in nickel-based superalloys produced by HEB-AM are outlined.This review provides an in-depth and comprehensive understanding of the cracking problem in AM nickel-based superalloys.It also provides valuable references for AM crack-free nickel-based superalloy components.

Li-rich layered oxides:Structure,capacity and voltage fading mechanisms and solving strategies

Lithium rich layered oxides(LLOs)are attractive cathode materials for Li-ion batteries owing to their high capacity(>250 mA h g^(-1))and suitable voltage(∼3.6 V).However,they suffer from serious voltage and capacity fading,which is focused in this review.First,an overview of crystal structure,band structure and electrochemical performances of LLOs is provided.After that,current understanding on oxygen loss,capacity fading and voltage fading is summarized.Finally,five strategies to mitigate capacity and voltage fading are reviewed.It is believed that these understandings can help solve the fading problems of LLOs.

Polymorphism analysis of Glutathione S-transferase A1 in patients with hematological diseases and its effect on GST enzyme activity

Glutathione S-transferases(GSTs)are important drug-metabolizing enzymes that catalyze the binding of glutathione(GSH)to electrophilic substances.GST has genetic polymorphism,and the enzyme activity of GST affects the metabolism of certain drugs in vivo.In the present day,we investigated the GST enzyme activity and GSTA1 gene polymorphism in 170 patients with hematological diseases and explored their relationship.The GSTA1 gene polymorphism of the patient was analyzed by PCR-restriction fragment length polymorphism(PCR-RFLP)technique,and the base sequences of the four mutation sites(-631,-567,-69,and-52)in the promoter region were determined by DNA-Sequencer.The patient’s GST enzyme activity was calculated by measuring the rate at which it catalyzed the reaction between 1-chloro-2,4-dinitrobenzene(CDNB)and GSH.The average GST enzyme activities of males and females were 5.20±0.13 and 5.17±0.12 nmol/min/mL,respectively,and the difference was not significant(P=0.91).The frequencies of genotypes GSTA1*A*A(wild genotype),GSTA1*A*B(heterozygous genotype),and GSTA1*B*B(homozygous mutant genotype)were 75.3%,22.9%,and 1.8%,respectively.Alleles GSTA1*A and*B were distributed at 86.8%and 13.2%,respectively.The genotype frequency distribution between males and females was no significant difference by Pearson’s chi-square test(P=0.743).The average GST activity of the heterozygous mutant genotype(4.83±0.76 nmol/min/mL)was lower than the wild genotype(5.34±1.26 nmol/min/mL,P=0.018),and higher than that of the homozygous mutant genotype(3.32±0.07 nmol/min/mL,P=0.022).These findings might help us improve the individualized treatment of patients with hematological diseases in the future and promote the development of precision medicine for blood diseases.