吸油纤维电纺过程影响因素的研究进展

近年来,石油漏油事故和大量工业及生活污水的排放,导致油类污染持续加剧,对生态环境造成了严重危害,研究和制备高效吸油材料,去除水中油类污染物,减少对环境的危害,已成为当务之急。文中综述了高吸油树脂的吸油机理,比较了天然与合成吸油材料,重点探讨了电纺纤维的多孔、中空及串珠结构对吸油效果的影响,并对影响纤维结构的因素进行了论述,最后展望了电纺吸油纤维的发展方向。

废旧聚氨酯泡沫醇解产物作为再生剂实现废橡胶的力化学再生

近年来,废聚氨酯和废橡胶产量呈上升趋势,其资源化循环利用成为研究热点。文中使用丙二醇作为醇解剂在不同温度下分解聚氨酯泡沫,并利用聚氨酯醇解产物作为再生剂实现了废橡胶的力化学再生。醇解产物下层液(PAPL)含有较多的胺类基团,可与橡胶再生过程中产生的自由基结合,提高橡胶的脱硫程度,从而提高再生胶(RRs)的力学性能。与只填加活化剂的RRs相比,在原有活化剂填加份数的基础上,加入PAPL可缩短RRs的最佳硫化时间,提高交联密度。使用180℃制备的聚氨酯醇解产物下层液,RRs硫化橡胶的综合性能最好,拉伸强度达到15.6MPa,断裂伸长率达到325.5%。该方法实现了废聚氨酯和废橡胶的双重高价值回收,应用前景广阔。

The gut-liver axis mechanism of increased susceptibility to non-alcoholic fatty disease in female offspring rats with prenatal caffeine exposure

Caffeine intake during pregnancy is common,while its effect on gut microbiota composition of offspring and the relationship with susceptibility to adult diseases remains unclear.This study aimed to confirm the effects of prenatal caffeine exposure(PCE)on the gut microbiota composition and its metabolites in female offspring rats,and to further elucidate its underlying mechanism and intervention targets in adult non-alcoholic fatty disease(NAFLD).The results showed that the gut microbiota of PCE female offspring at multiple time points from infancy to adolescence were significantly changed with depletion of butyric acid-producing bacteria,leading to a decrease in butyric acid in adulthood.It was also found that PCE female offspring rats were sensitive to NAFLD induced by a postnatal high-fat diet(HFD),which is mainly related to the enhancement of hepatic triglyceride synthesis function.Through mechanism exploration,we found that HFD further reduced the fecal and serum butyric acid levels in the PCE female offspring,which was significantly negatively correlated with hepatic SREBP-1c/FASN mRNA expression and triglyceride level.In vivo and in vitro experiments confirmed that sodium butyrate(NaB)supplementation could reduce hepatic lipid accumulation through MCT1/GPR109A-AMPK,thereby effectively decreasing the susceptibility to NAFLD in the PCE female offspring rats.

Insights into sensitizing and eliciting capacity of gastric and gastrointestinal digestion products of shrimp(Penaeus vannamei)proteins in BALB/c mice

Shrimp(Penaeus vannamei)proteins have been shown an allergenic potential;however,little information is available on the sensitizing and eliciting capacity of shrimp protein digestion products.In this study,a BALB/c mice model was used to explore the allergenicity of shrimp protein sample(SPS)and their gastric and gastrointestinal digestion products(GDS/GIDS).As compared with the SPS groups,the GDS/GIDS groups caused lower specific immunoglobulins(Ig E/Ig G1)levels(P<0.05),but higher than the control groups,indicating that the digestion products sensitized the mice.Meanwhile,spleen index,mouse mast cell protease-1(m MCP-1)concentration and proportion of degranulated mast cells were significantly reduced in the GDS/GIDS groups(P<0.05);simultaneously,allergic symptoms,vascular permeability and histopathological changes of tissues were alleviated.Nevertheless,the allergenicity of digestion products cannot be eliminated and still cause systemic allergic reactions in mice.The study showed that the digestion products of shrimp still had high sensitizing and eliciting capacity.

菌中之冠——银耳

银耳原产中国,可药食两用,历来深受人们喜爱,素有菌中之冠的美誉。论文以拟人化手法通过一场“黄白”银耳的庭审官司,悬念丛生地展开故事情节,形象生动地科普了银耳的外观、生活环境、栽培技术、功能应用以及与香灰菌的“伴生”关系等内容,并及时制止了一起“假燕窝”事件、当庭教育了造假者,以维护银耳世界的公平和良性竞争环境。旨在传播科学知识,弘扬科学精神,培养学生的职业道德观和社会责任感。

Ginsenoside Rc:A potential intervention agent for metabolic syndrome

Ginsenoside Rc,a dammarane-type tetracyclic triterpenoid saponin primarily derived from Panax ginseng,has garnered significant attention due to its diverse pharmacological properties.This review outlined the sources,putative biosynthetic pathways,extraction,and quantification techniques,as well as the pharmacokinetic properties of ginsenoside Rc.Furthermore,this study explored the pharmacological effects of ginsenoside Rc against metabolic syndrome(MetS)across various phenotypes including obesity,diabetes,atherosclerosis,non-alcoholic fatty liver disease,and osteoarthritis.It also highlighted the impact of ginsenoside Rc on multiple associated signaling molecules.In conclusion,the anti-MetS effect of ginsenoside Rc is characterized by its influence on multiple organs,multiple targets,and multiple ways.Although clinical investigations regarding the effects of ginsenoside Rc on MetS are limited,its proven safety and tolerability suggest its potential as an effective treatment option.

医学图像运动伪影校正的实验课程设计

医学图像处理是生物医学工程本科专业的一门重要课程,它主要利用数学、计算机科学和信息学等工具对医学成像设备产生的医学图像进行处理和加工,已成为医学研究、临床疾病诊断中一个不可或缺的工具和技术手段。但是在实际教学中,如何有效设计医学图像处理实验课程,培养学生发现问题和解决问题的能力,使学生将理论知识应用到临床实践当中面临巨大的挑战。图像退化与复原是医学图像处理中的重要内容,本实验课程围绕医学图像退化及复原中的运动伪影校正这一关键问题,以临床磁共振成像图像为数据来源,进行系统实验课程设计,通过该实验课程的学习,学生不但理解了图像退化及复原原理,掌握医学图像信息处理技能,还提高了设计实验、分析问题解决问题的能力,真正做到理论与临床实践相结合。

Ionic liquids for high performance lithium metal batteries

The pursuit of high energy density has promoted the development of high-performance lithium metal batteries.However,it faces a serious security problem.Ionic liquids have attracted great attention due to their high ionic conductivity,non-flammability,and the properties of promoting the formation of stable SEI films.Deeply understanding the problems existing in lithium metal batteries and the role of ionic liquids in them is of great significance for improving the performance of lithium metal batteries.This article reviews the effects of the molecular structure of ionic liquids on ionic conductivity,Li^(+)ion transference number,electrochemical stability window,and lithium metal anode/electrolyte interface,as well as the application of ionic liquids in Li-high voltage cathode batteries,Li-O_(2) batteries and Li-S batteries.The molecular design,composition and polymerization will be the main strategies for the future development of ionic liquid-based electrolytes for high performance lithium metal battery.

Organic anion transporters also mediate the drug–drug interaction between imipenem and cilastatin

This study aimed to clarify that organic anion transporters(OATs)mediate the drug–drug interaction(DDI)between imipenem and cilastatin.After co-administration with imipenem,the plasma concentrations and the plasma concentration-time curve(AUC)of cilastatin were significantly increased,while renal clearance and cumulative urinary excretion of cilastatin were decreased.At the same time,imipenem significantly inhibited the uptake of cilastatin in rat kidney slices and in human OAT1(hOAT1)-HEK293 and human OAT3(hOAT3)-HEK293 cells.Probenecid,p-aminohippurate,and benzylpenicillin inhibited the uptake of imipenem and cilastatin in rat kidney slices and in hOAT1-and hOAT3-HEK 293 cells,respectively.The uptakes of imipenem and cilastatin in hOAT1-and hOAT3-HEK 293 cells were significantly higher than that in mock-HEK-293 cells.Moreover,the K m values of cilastatin were increased in the presence of imipenem with unchanged V max,indicating that imipenem inhibited the uptake of cilastatin in a competitive manner.When imipenem and cilastatin were co-administered,the level of imipenem was higher compared with imipenem alone both in vivo and in vitro.But,cilastatin significantly inhibited the uptake of imipenem when dehydropeptidase-1(DPEP1)was silenced by RNAi technology in hOAT1-and hOAT3-HEK 293 cells.In conclusion,imipenem and cilastatin are the substrates of OAT1 and OAT3.OAT1 and OAT3 mediate the DDI between imipenem and cilastatin.Meanwhile,cilastatin also reduces the hydrolysis of imipenem by inhibiting the uptake of imipenem mediated by OAT1 and OAT3 in the kidney as a complement.

Operational procedures of auricular point sticking technology

As an external treatment technique of traditional Chinese medicine(TCM),auricular point sticking,which is rooted in holographic biology theory and TCM viscera and meridian theory,is a safe and effective treatment method.This article introduces the technology overview and development process.The auricular point sticking technique for constipation is taken as an example to specify the basic requirements,assessment,operational points,acupoint selection and matters needing attention during the implementation of the auricular acupressure technique,providing a reference for the operating procedures of this technique in the clinical treatment of other diseases such as insomnia,diarrhea,colds,hypertension,headache,and dysmenorrhea.

石墨烯结构的二维光子晶体禁带特性研究

本文设计了圆形、六边形两种散射元并引用二维石墨烯的蜂窝状结构,基于对光子晶体禁带的研究,利用平面波展开法,对这二种散射元构建的蜂窝状光子晶体的禁带特性进行模拟计算。分别得到了在TE和TM两种电磁场模式下光子晶体的禁带宽度,对相对禁带宽度关于散射元结构参数变化的关系做了分析,依据相对禁带宽度的大小,得到了相对禁带最大的模型。

Piperacillin enhances the inhibitory effect of tazobactam on β-lactamase through inhibition of organic anion transporter 1/3 in rats

To assess the mechanism of the pharmacokinetic interaction between piperacillin and tazobactam,renal excretion and pharmacokinetic studies of piperacillin/tazobactam were investigated in normal and bacteremia rats.A bacteremia model was established to investigate the pharmacokinetic properties of piperacillin and tazobactam under different conditions.Renal slices were taken to examine the uptake of piperacillin and tazobactam.Pharmacokinetic studies ofβ-lactamase in rats were performed to study the contribution of rOat1/3 to the inhibition of tazobactam onβ-lactamase.The AUC(from 2.93±0.58 to 6.52±1.44 mg·min/ml)and the plasma clearance(CL P)(from 2.41±1.20 to 0.961±0.212 ml/min/kg)of tazobactam were both altered after the intravenous coadministration of piperacillin and tazobactam in the bacteremia rats.The renal clearance(CL R)of tazobactam decreased from 1.30±0.50 to 0.361±0.043 ml/min/kg.In summary,there was a beneficial interaction between piperacillin and tazobactam mediated by rOat1 and rOat3.Piperacillin enhances the inhibitory effect of tazobactam onβ-lactamase through the inhibition of rOat1 and rOat3 in rats.The contribution rate of rOat1/3 for the synergistic effect was 20%when the two drugs were coadministered.

The transporters of intestinal tract and techniques applied to evaluate interactions between drugs and transporters

Most drug products on the global pharmaceutical market are administered orally.The absorption of oral drug in the intestine is an important factor to determine the drug bioavailability.There are many intestinal transporters expressed on the small intestine and the transporters can be classified into two major families,SLC family and ABC family.They mediate drug absorption,distribution,excretion and drugedrug interaction.Understanding the transport mechanism can improve the effectivity and safety of drug and guide clinical rational use of drugs.The roles of drug transporters can be assessed in vitro and in vivo,using techniques spanning from cellular expression systems to gene knockout animals.The purposes of this article were to introduce the main transporters in the intestinal tract,to explain the transport mechanism and to compare the limitations and applications of techniques used to evaluate interactions of drugs and transporters.

Device design based on the covalent homocouplingof porphine molecules

Porphine has a great potential application in molecular electronic devices.In this work,based on the density functional theory(DFT)and combining with nonequilibrium Green's function(NEGF),we study the transport properties of the molecular devices constructed by the covalent homocoupling of porphine molecules conjunction with zigzag graphene nanoribbons electrodes.We find that different couple phases bring remarkable differences in the transport properties.Different coupling phases have different application prospects.We analyze and discuss the differences in transport properties through the molecular energy spectrum,electrostatic difference potential,local density of states(LDOS),and transmission pathway.The results are of great significance for the design of porphine molecular devices in the future.

Potassium transporter OsHAK9 regulates seed germination under salt stress by preventing gibberellin degradation through mediating OsGA2ox7 in rice

Soil salinity has a major impact on rice seed germination,severely limiting rice production.Herein,a rice germination defective mutant under salt stress(gdss)was identified by using chemical mutagenesis.The GDSS gene was detected via MutMap and shown to encode potassium transporter OsHAK9.Phenotypic analysis of complementation and mutant lines demonstrated that OsHAK9 was an essential regulator responsible for seed germination under salt stress.OsHAK9 is highly expressed in germinating seed embryos.Ion contents and non-invasive micro-test technology results showed that OsHAK9 restricted K^(+)efflux in salt-exposed germinating seeds for the balance of K^(+)/Na^(+).Disruption of OsHAK9 significantly reduced gibberellin 4(GA4)levels,and the germination defective phenotype of oshak9a was partly rescued by exogenous GA_(3)treatment under salt stress.RNA sequencing(RNA-seq)and real-time quantitative polymerase chain reaction analysis demonstrated that the disruption of OsHAK9 improved the GA-deactivated gene OsGA2ox7 expression in germinating seeds under salt stress,and the expression of OsGA2ox7 was significantly inhibited by salt stress.Null mutants of OsGA2ox7 created using clustered,regularly interspaced,short palindromic repeat(CRISPR)/CRISPR-associated nuclease 9 approach displayed a dramatically increased seed germination ability under salt stress.Overall,our results highlight that OsHAK9 regulates seed germination performance under salt stress involving preventing GA degradation by mediating OsGA2ox7,which provides a novel clue about the relationship between GA and OsHAKs in rice.

Hexamerin and allergen are required for female reproduction in the American cockroach,Periplaneta americana

Reproduction is of great importance for the continuation of the species.In insects,the fat body is the major tissue for nutrient storage and involved in vitellogenesis,which is essential for female reproduction.Here,2 proteins,hexamerin and allergen,were separated from the fat bodies of adult female American cockroaches(Periplaneta americana)and identified as storage proteins,encoding for 733 amino acids with molecular weight of 87.88 kDa and 686 amino acids with molecular weight of 82.18 kDa,respectively.The encoding genes of these 2 storage proteins are mainly expressed in the fat body.RNA interference-mediated knockdown of Hexamerin and Allergen in the early stage of the first reproductive cycle in females suppressed vitellogenesis and ovarian maturation,indicating that these storage proteins are involved in controlling reproduction.Importantly,the expression of Hexamerin and Allergen was repressed by knockdown of the juvenile hormone(JH)receptor gene Met and the primary response gene Kr-h1,and was induced by methoprene,a JH analog,in both in vivo and in vitro experiments.Altogether,we have determined that hexamerin and allergen are identified as storage proteins and play an important role in promoting female reproduction in the American cockroach.The expression of their encoding genes is induced by JH signaling.Our data reveal a novel mechanism by which hexamerin and allergen are necessary for JH-stimulated female reproduction.

NIR-II Organic Photothermal Cocrystals with Strong Charge Transfer Interaction for Flexible Wearable Heaters

The organic cocrystal strategy has provided a convenient and efficient platform for preparing organic photothermal materials.However,the rapidly directional preparation of cocrystals with desirable photothermal properties remains challenging due to a lack of suitable design ideas.Here,two new photothermal cocrystals,MTC and MFC,based on acceptor molecules(TCNQ and F4TCNQ)with different electron-withdrawing capacities were quickly prepared by the coprecipitation method,aiming to explore the effect of charge transfer(CT)interaction on photothermal properties.Compared with MTC,the stronger intermolecular CT interaction in MFC facilitates extending the absorption range(from the NIR-I to the NIR-II region)and enhancing the non-radiative transition process.Under the 808 nm laser irradiation,the photothermal conversion efficiency(PCE)of MFC is 54.6%,whereas MTC displays a mere 36.8%.The MFC cocrystal was further combined with a flexible polymer substrate(HPDMS)to prepare a flexible wearable heater(HPDMS@MFC),which exhibits excellent NIR-II photothermal performance.This work points out a research direction for the rapid assembly of efficient photothermal cocrystals and additionally provides an extensive application prospect for organic photothermal cocrystals in the field of wearable devices.

Blockchain based federated learning for intrusion detection for Internet of Things

In Internet of Things(loT),data sharing among different devices can improve manufacture efficiency and reduce workload,and yet make the network systems be more vulnerable to various intrusion attacks.There has been realistic demand to develop an efficient intrusion detection algorithm for connected devices.Most of existing intrusion detection methods are trained in a centralized manner and are incapable to identify new unlabeled attack types.In this paper,a distributed federated intrusion detection method is proposed,utilizing the information contained in the labeled data as the prior knowledge to discover new unlabeled attack types.Besides,the blockchain technique is introduced in the federated learning process for the consensus of the entire framework.Experimental results are provided to show that our approach can identify the malicious entities,while outperforming the existing methods in discovering new intrusion attack types.

Optimizing depth of field in 3D light-field display by analyzing and controlling light-beam divergence angle

A concept of divergence angle of light beams(DALB)is proposed to analyze the depth of field(DOF)of a 3D light-field display system.The mathematical model between DOF and DALB is established,and the conclusion that DOF and DALB are inversely proportional is drawn.To reduce DALB and generate clear depth perception,a triple composite aspheric lens structure with a viewing angle of 100°is designed and experimentally demonstrated.The DALB-constrained 3D light-field display system significantly improves the clarity of 3D images and also performs well in imaging at a 3D scene with a DOF over 30 cm.

北京大学重离子物理研究所40年发展历程

北京大学重离子物理研究所是在北京大学原技术物理系的基础上发展起来的.北京大学技术物理系成立于1955年(初期称物理研究室),是我国第一个核科学研究和人才培养基地,几十年来为国家培养了5000多名核科学技术人才.20世纪80年代初,针对当时核科学与技术的发展形势,北京大学酝酿成立重离子物理研究所.