高透明度和高强度的纳米粘合水凝胶贴片用于组织粘附

本研究旨在设计和制备一种具有优异机械性能和生物相容性的双层结构壳聚糖水凝胶粘合贴片,并借助纳米粘合策略评估其组织粘附性能。以物理交联构建坚韧的壳聚糖水凝胶作为背膜,随后通过原位光交联制备粘合剂水凝胶层,形成一体化的壳聚糖水凝胶粘合贴片。利用纳米胶水促进贴片与基底之间的纳米粘合。表面活化的二氧化硅纳米颗粒作为类似于纳米胶的界面连接器,促进水凝胶与基底的结合,以建立水凝胶贴片与生物组织之间的粘附关系。分析结果显示,水凝胶贴片在体外对生物组织的粘合能量为282 J/m^(2),爆破压力为450 mmHg(1 mmHg=0.133 kPa)。该贴片具有4.3 MPa的拉伸强度、65%的断裂伸长率和3.82 kJ/m^(2)的断裂韧性,具有出色的机械性能。此外,这种基于纳米粘合剂的壳聚糖水凝胶粘合贴片具有高透明度和优异的生物相容性,有望在组织修复和药物输送等多个生物医学领域得到应用,为临床外科手术的发展提供坚实的材料基础。

基于网络药理学探讨人参皂苷Rg1对神经母细胞瘤作用机制

目的:从网络药理学角度探讨人参皂苷Rg1与神经母细胞瘤(NB)的核心靶点及其分子作用机制。方法:利用PharmMapper等数据库筛选Rg1治疗NB的作用靶点并进行GO/KEGG富集分析、核心靶点筛选、Hub基因预后模型以及分子对接模型,分析Hub基因在神经母细胞瘤作用机制。结果:初步筛选出Rg1-NB交集靶点129个,GO、KEGG分析结果发现Rg1可能通过PI3K/Akt、MAPK、JAK/STAT信号通路影响神经母细胞瘤增殖、迁移、凋亡等生物过程;PPI互作聚类分析结果表明,Rg1可能通过调控细胞凋亡、生物节律、酪氨酸蛋白激酶等发挥治疗作用;通过对Rg1治疗NB作用靶点进行Hub基因筛选以及基因、表型分析,发现Rg1治疗Hub基因为AKT1、MTOR、STAT3,进一步预后模型分析发现STA3高表达组的NB患者的生存率显著高于低表达,说明STAT3为预后保护因素,且Rg1与STAT3有9个结合位点,结合自由能为-6.57 kcal/mol,结合效果较好。结论:通过数据库筛选出3个人参皂苷Rg1治疗神经母细胞瘤核心靶点依次为AKT1、MTOR、STAT3,进一步通过建立核心基因预后模型、分子对接实验及GO、KEGG分析表明,人参皂苷Rg1可能通过JAK/STAT信号通路发挥功能,影响神经母瘤细胞的发展,为Rg1治疗神经母细胞瘤分子机制、药物靶点的选择及新型治疗技术的开发提供一定的参考和理论依据。

基于六水铝酸三钙的双电层调控从铝酸钠溶液中短流程脱除有机物

从铝酸钠溶液中经济地脱除有机物是长期以来的研究重点。基于叶滤环节将六水铝酸三钙(TCA)作为助滤剂的工艺,提出一种短流程同时滤除杂质颗粒和吸附脱除有机物的新方法。在浓缩铝酸钠溶液中制备结晶度低、TCA含量高、表面能高、晶格畸变大的超细TCA样品。同时,TCA样品在碱性溶液中的Zeta电位线性依赖于TCA含量,揭示二元混合物Zeta电位的可加性。描述在碱性溶液中TCA二元混合物双电层的演化规律。此外,超细TCA样品对长烷基链及高相对分子质量有机物具有较高的吸附容量,对腐殖酸钠的吸附容量可达69.69mg/g(以有机碳计),而高温溶出过程会显著降低TCA的吸附容量。

Genetic analysis and candidate gene identification of salt tolerancerelated traits in maize

Soil salinization poses a threat to maize production worldwide,but the genetic mechanism of salt tolerance in maize is not well understood.Therefore,identifying the genetic components underlying salt tolerance in maize is of great importance.In the current study,a teosinte-maize BC2F7 population was used to investigate the genetic basis of 21 salt tolerance-related traits.In total,125 QTLs were detected using a high-density genetic bin map,with one to five QTLs explaining 6.05–32.02%of the phenotypic variation for each trait.The total phenotypic variation explained(PVE)by all detected QTLs ranged from 6.84 to 63.88%for each trait.Of all 125 QTLs,only three were major QTLs distributed in two genomic regions on chromosome 6,which were involved in three salt tolerance-related traits.In addition,10 pairs of epistatic QTLs with additive effects were detected for eight traits,explaining 0.9 to 4.44%of the phenotypic variation.Furthermore,18 QTL hotspots affecting 3–7 traits were identified.In one hotspot(L5),a gene cluster consisting of four genes(ZmNSA1,SAG6,ZmCLCg,and ZmHKT1;2)was found,suggesting the involvement of multiple pleiotropic genes.Finally,two important candidate genes,Zm00001d002090 and Zm00001d002391,were found to be associated with salt tolerance-related traits by a combination of linkage and marker-trait association analyses.Zm00001d002090 encodes a calcium-dependent lipid-binding(CaLB domain)family protein,which may function as a Ca^(2+)sensor for transmitting the salt stress signal downstream,while Zm00001d002391 encodes a ubiquitin-specific protease belonging to the C19-related subfamily.Our findings provide valuable insights into the genetic basis of salt tolerance-related traits in maize and a theoretical foundation for breeders to develop enhanced salt-tolerant maize varieties.

An Introduction to the Dissemination of Chinese Culture in English Teaching in Colleges and Universities

Language and culture are closely related,and understanding the cultural knowledge embedded in the process of language learning is an important goal of English teaching in colleges and universities.At present,the dissemination of Chinese culture in English teaching in colleges and universities is lacking,which affects the improvement of students’intercultural communication skills.In order to effectively solve such problems,we need to take effective measures to disseminate Chinese culture by combining teaching content and students’characteristics.This paper summarizes the problems of Chinese culture dissemination in English teaching in colleges and universities,and explores effective countermeasures and teaching considerations,hoping to provide teachers with valuable guidelines.

非小细胞肺癌中RASSF6与MST1的表达及病理意义

目的检测RAS相关结构域家族成员6基因(RASSF6)及MST1在非小细胞肺癌(NSCLC)中的表达情况,并探讨二者对NSCLC患者的病理意义。方法利用GEPIA2数据库测定肺腺癌(LUAD)和肺鳞癌(LUSC)中RASSF6和MST1基因表达水平;通过qRT-PCR实验测定NSCLC新鲜组织中RASSF6、MST1 mRNA表达水平;免疫组化法检测石蜡标本中RASSF6、MST1蛋白表达。Spearman探讨二者的相互关系。结果与癌旁正常肺组织比较,NSCLC的RASSF6 mRNA和蛋白表达水平均明显增加(P<0.05),但MST1 mRNA和蛋白表达水平均明显降低(P<0.05)。RASSF6及MST1蛋白表达均与临床分期、淋巴结转移相关(P<0.05),而与NSCLC患者的年龄、性别、组织分型及分化程度无关(P>0.05);且RASSF6与MST1呈负相关(r_(s)=-0.227,P<0.05)。结论RASSF6和MST1可能与NSCLC的进展有关,有望成为NSCLC患者新的潜在治疗靶点。

可穿戴脑电图设备关键技术及其应用综述

可穿戴脑电图(EEG)设备是一种用于日常实时监测的无线EGG系统,因其便携性、实时性、无创性及低成本等优势迅速发展并得到广泛应用。该系统主要由信号采集模块、信号处理模块、微控制模块、通信模块及电源模块等硬件部分以及移动终端模块和云存储模块等软件部分组成。就可穿戴EEG设备关键技术进行论述。首先,阐述了对EGG信号采集模块的改进,另外对可穿戴EEG设备信号预处理模块、信号的降噪、伪影处理及特征提取技术进行比较;然后,对机器学习、深度学习分类算法的优缺点进行分析,并对穿戴式EEG设备的应用领域进行总结;最后,提出可穿戴EEG设备的关键技术未来的发展趋势。

基于稀土元素和稳定同位素指纹的枸杞道地性表征

目的探讨稀土元素结合C、N稳定同位素在枸杞原产地判别中的可行性,为枸杞地理标志产品保护提供技术支撑。方法采集宁夏、甘肃、青海和新疆4个产区共232份枸杞样本,采用电感耦合等离子体质谱法(inductively coupled plasma mass spectrometry,ICP-MS)及元素分析-稳定同位素比值质谱法(elementary analysis-isotope ratio mass spectrometers,EA-IRMS)测定枸杞中14种稀土元素及C、N稳定同位素比值,结合化学计量学方法分析了监测指标在枸杞发育过程中的变化规律,构建了枸杞产地判别模型。结果随着枸杞发育,稀土元素及C、N稳定同位素具有明显的变化规律:La呈先降低再升高再降低的趋势,Sc呈先升高后降低的趋势,Ce、Nd、Y、Pr、Yb、Dy、Gd、Sm、Eu、Tb、Ho、Tm 12种稀土元素及δ^(15)N呈先降低后升高的趋势;除Eu、Yb和Tm元素外,其他稀土元素在4个枸杞产区或部分产区间存在显著差异,δ^(13)C、δ^(15)N在部分产区间存在显著差异;主成分分析可提取出5个主成分,前2个主成分可有效区分新疆、青海的枸杞样品,宁夏和甘肃的样品不能有效区分;采用Fisher线性判别分析方法构建了基于La、Nd、Sc、Y、Pr、Eu、Yb、Dy、Gd、Tb、Ho、Tm、δ^(13)C、δ^(15)N 14个指标的枸杞产地判别模型,判别模型正确判别率在90.0%以上。结论基于稀土元素和C、N稳定同位素指纹的差异可以有效鉴别不同产地的枸杞。

基于转录组测序筛选鹿茸胸腺素促成骨细胞增殖基因

目的对Tβ4蛋白处理组和空白组进行转录组测序,筛选Tβ4蛋白处理后促成骨细胞相关的候选基因和通路。方法通过Fmoc固相合成法体外合成梅花鹿Tβ4蛋白,并处理MC3T3细胞,CCK8法检测细胞活性。将细胞分为空白组和Tβ4处理组,利用Illumina平台进行高通量测序。对差异表达基因进行GO功能富集分类和KEGG通路分析,构建差异基因的蛋白互作网络并筛选Hub基因,通过在线软件对Hub基因进行富集分析。结果Tβ4蛋白处理成骨细胞显著促进了细胞的增殖活性。获得差异基因6106个,其中上调基因1979个,下调基因4127个。根据PPI网络中的节点连通度,得到10个Hub基因,其中,筛选到7个与成骨细胞增殖相关的候选基因,分别为CDC20、PLK1、CDK1、BUB1B、BUB1、MAD2L1、RRM2,这些基因富集到了细胞周期信号通路和p53信号通路。结论梅花鹿Tβ4蛋白处理后可以提高细胞的增殖活性和存活率。梅花鹿胸腺素Tβ4可能是通过调控细胞周期信号通路和p53信号通路中的关键基因达到促进成骨细胞增殖的功能。

Emergency internal iliac artery temporary occlusion after massive hemorrhage during surgery of cesarean scar pregnancy:A case report

BACKGROUND Cesarean scar pregnancy(CSP)is rare but may result in uterine rupture during pregnancy or massive hemorrhage during abortion procedures.Awareness of this condition is increasing,and most patients with CSP are now diagnosed early and can be managed safely.However,some atypical patients are misdiagnosed,and their surgical risks are underestimated,increasing the risk of fatal hemorrhage.CASE SUMMARY A 27-year-old Asian woman visited our institution because of abnormal pregnancy,and she was diagnosed with a hydatidiform mole through transvaginal ultrasound(TVS).Under hysteroscopy,a large amount of placental tissue was found in the scar of the lower uterine segment,and a sudden massive hemorrhage occurred during the removal process.The bilateral internal iliac arteries were temporarily blocked under laparoscopy,and scar resection and repair were rapidly performed.She was discharged in good condition 5 d after the operation.CONCLUSION Although TVS is widely used in the diagnosis of CSP,delays in the diagnosis of atypical CSP remain.Surgical treatment following internal iliac artery temporary occlusion may be an appropriate management method for unanticipated massive hemorrhage during CSP surgery.

A multifunctional osteogenic system of ultrasonically spray deposited bone-active coatings on plasma-activated magnesium

Biomimetic bone-active coatings composed of inorganic nano-hydroxyapatite(i.e.,nHA)and organic silk fibroin(i.e.,SF)are layer-by-layer deposited on Mg-Zn-Ca alloy by a controllable ultrasonic spray method.Meanwhile,plasma activation is developed as a promising strategy to pretreat magnesium surfaces,which facilitates the direct adhesion of coatings with enhanced bonding interfaces.In this work,we engineer the nHA/SF composite coatings with excellent mechanical properties and adhesion force.The optimized parameters of ultrasonic spray bring significant influence on the surface morphologies of coatings.Assisted by hybrid plasma of oxygen and nitrogen(i.e.,O_(2)/N_(2) plasma),the activated Mg-Zn-Ca surfaces are uniformly covered by a robust and compact nHA/SF composite coating,establishing a multifunctional system with superior corrosion resistance and biological performance.Interestingly,secondary oxygen plasma treatment of nHA/SF coatings(A-nHA/SF)promotes the hydrophilicity,leading to a rapid self-repair effect from surface damage.The improvement of anti-corrosion and self-repair provides a dependable platform for better cell adhesion,proliferation,spreading and differentiation.These favorable factors contribute to the preferable in vivo biocompatibility and the promotion of newly formed bones for the A-nHA/SF-coated Mg implants.This study lays important foundations for coating strategy on biomedical magnesium alloy as multifunctional osteogenic system in bioactive implantable applications.

Single-cell transcriptome atlas reveals spatiotemporal developmental trajectories in the basal roots of moso bamboo (Phyllostachys edulis)

Roots are essential for plant growth and development.Bamboo is a large Poaceae perennial with 1642 species worldwide.However,little is known about the transcriptional atlas that underpins root cell-type differentiation.Here,we set up a modified protocol for protoplast preparation and report single-cell transcriptomes of 14279 filtered single cells derived from the basal root tips of moso bamboo.We identified four cell types and defined new cell-type-specific marker genes for the basal root.We reconstructed the developmental trajectories of the root cap,epidermis,and ground tissues and elucidated critical factors regulating cell fate determination.According to in situ hybridization and pseudotime trajectory analysis,the root cap and epidermis originated from a common initial cell lineage,revealing the particularity of bamboo basal root development.We further identified key regulatory factors for the differentiation of these cells and indicated divergent root developmental pathways between moso bamboo and rice.Additionally,PheWOX13a and PheWOX13b ectopically expressed in Arabidopsis inhibited primary root and lateral root growth and regulated the growth and development of the root cap,which was different from WOX13 orthologs in Arabidopsis.Taken together,our results offer an important resource for investigating the mechanism of root cell differentiation and root system architecture in perennial woody species of Bambusoideae.

Core fucosylation and its roles in gastrointestinal glycoimmunology

Glycosylation is a common post-translational modification in eukaryotic cells.It is involved in the production of many biologically active glycoproteins and the regulation of protein structure and function.Core fucosylation plays a vital role in the immune response.Most immune system molecules are core fucosylated glycoproteins such as complements,cluster differentiation antigens,immunoglobulins,cytokines,major histocompatibility complex molecules,adhesion molecules,and immune molecule synthesis-related transcription factors.These core fucosylated glycoproteins play important roles in antigen recognition and clearance,cell adhesion,lymphocyte activation,apoptosis,signal transduction,and endocytosis.Core fucosylation is dominated by fucosyltransferase 8(Fut8),which catalyzes the addition ofα-1,6-fucose to the innermost GlcNAc residue of N-glycans.Fut8 is involved in humoral,cellular,and mucosal immunity.Tumor immunology is associated with aberrant core fucosylation.Here,we summarize the roles and potential modulatory mechanisms of Fut8 in various immune processes of the gastrointestinal system.

Harmonic State-Space Based AC-Side Impedance Model of MMC and High Frequency Oscillation Characteristics Analysis

Recently,high-frequency oscillation of themodularmultilevel converter(MMC)based high-voltage direct current(HVDC)projects has attracted great attentions.In order to analyze the small-signal stability,this paper uses the harmonic state-space(HSS)method to establish a detailed frequency domain impedance model of the AC-side of the HVDC transmission system,which considers the internal dynamic characteristics.In addition,the suggested model is also used to assess the system’s high-frequency oscillationmechanism,and the effects of the MMC current inner loop control,feedforward voltage links,and control delay on the high-frequency impedance characteristics and the effect of higher harmonic components.Finally,three oscillation suppression schemes are analyzed for the oscillation problems occurring in actual engineering,and a simplified impedance model considering only the highfrequency impedance characteristics is established to compare the suppression effect with the detailed impedance model to prove its reliability.

Analysis of Additional Damping Control Strategy and Parameter Optimization for Improving Small Signal Stability of VSC-HVDC System

The voltage source converter based high voltage direct current(VSC-HVDC)system is based on voltage source converter,and its control system is more complex.Also affected by the fast control of power electronics,oscillation phenomenon in wide frequency domain may occur.To address the problem of small signal stability of the VSCHVDC system,a converter control strategy is designed to improve its small signal stability,and the risk of system oscillation is reduced by attaching a damping controller and optimizing the control parameters.Based on the modeling of the VSC-HVDC system,the general architecture of the inner and outer loop control of the VSCHVDC converter is established;and the damping controllers for DC control and AC control are designed in the phase-locked loop and the inner and outer loop control parts respectively;the state-space statemodel of the control system is established to analyze its performance.And the electromagnetic transient simulation model is built on the PSCAD/EMTDC simulation platform to verify the accuracy of the small signal model.The influence of the parameters of each control part on the stability of the system is summarized.The main control parts affecting stability are optimized for the phenomenon of oscillation due to changes in operation mode occurring on the AC side due to faults and other reasons,which effectively eliminates system oscillation and improves system small signal stability,providing a certain reference for engineering design.

致密砂岩储层清洁压裂液返排液驱油实验研究及应用

清洁压裂液广泛应用于致密砂岩储层水力压裂施工中,而压裂施工后产生的大量清洁压裂液返排液具有处理难度大、回收利用率低以及环保压力大等问题,为实现清洁压裂液返排液的合理重复利用,以现场清洁压裂液返排液作为驱油剂,室内评价了其界面性能、润湿性能、乳化性能以及降压增注性能,并开展了驱油实验研究。结果表明:当清洁压裂液返排液质量分数为0.10%~0.15%时,可以使油水界面张力值降低至10-3 mN/m数量级,具有良好的界面活性;能使储层天然岩心表面的润湿性转变为亲水性,具有良好的润湿反转性能;可以使油水乳状液的析水率控制在30%以下,具有良好的乳化性能;能使天然岩心注入压力降低率达到50%以上,具有良好的降压增注效果。岩心模拟驱油实验结果表明,注入0.5 PV质量分数为0.10%~0.15%的清洁压裂液返排液后,能使天然岩心水驱后的采收率提高12%以上,具有良好的驱油效果。矿场试验结果表明,实施现场清洁压裂液返排液驱油措施后,目标区块生产井的产油量明显提升,含水率下降,取得了显著的增油效果。

饲粮中性洗涤纤维/非纤维性碳水化合物对泌乳驴产乳性能和营养物质表观消化率的影响

本试验旨在研究饲粮中性洗涤纤维/非纤维性碳水化合物(NFC/NDF)对泌乳驴产乳性能、泌乳期失重和营养物质表观消化率的影响,为泌乳期母驴饲粮的合理配制和驴乳成分的优化提供理论依据。采用单因素完全随机试验设计,将16头年龄为(6.73±1.16)岁、体重为(250.84±27.21)kg、胎次为(3.25±1.12)胎和泌乳天数为(40±4)d的德州驴分为对照组(CON组)和试验组(TRM组),每组8头,其中CON组饲喂精粗比30∶70(NDF/NFC为1.65)的饲粮,TRM组饲喂精粗比为40∶60(NDF/NFC为1.48)的饲粮,试验期8周。结果表明:整个试验期内,CON组挤奶量、估计产奶量、产乳效率、乳蛋白合成效率、乳蛋白产量、非脂固形物产量以及总固形物产量显著高于TRM组(P<0.05);CON组在试验全期干物质(DM)和总能(GE)表观消化率、第4周酸性洗涤纤维(ADF)表观消化率以及第8周NDF和钙(Ca)表观消化率显著高于TRM组(P<0.05);干物质采食量(DMI)、泌乳驴失重比例、常规乳成分含量在2组间差异均不显著(P>0.05)。由此可见,在等能等蛋白质饲粮条件下,饲粮精粗比由30∶70增加到40∶60,NDF/NFC由1.65降至1.48,不利于泌乳驴产乳性能的发挥和营养物质的消化,适当增加饲粮粗料比可以提高泌乳母驴的营养物质消化和产乳性能,改善乳品质。

泌乳驴产后不同时间的血清和乳中矿物元素含量变化规律的研究

试验旨在研究泌乳驴产后不同时间的血清和乳中常量元素(钙、磷、钾、镁)与微量元素(镉、钴、铬、钼、铅、铜、锰、硒、铁、锌)含量的变化规律。试验选取24头年龄、体重和预产期相近的德州三粉驴,分别于产后1、3、5、7、14、21、28和42 d采集乳样和血样。结果显示:产后不同时间对乳中常量元素与微量元素含量有显著影响(P<0.05),初乳中钙、钾、磷、镁、铁、铜、锰、锌、钴、硒、钼、铬含量高于常乳,尤其是产后1 d的初乳更高,之后逐渐降低;随泌乳天数增加,血清中钙、磷、镁、硒、钴和镉含量呈下降的趋势,多数以产后48 h内较高,镁含量在产后24 h降低明显;但血清中钾、铁、铜、锰、锌、铬含量无显著变化(P>0.05)。

梅花鹿茸不同生长时期转录组及蛋白组联合分析

目的了解鹿茸再生及快速生长过程中基因和蛋白的动态变化,阐明鹿茸生长发育机制。方法以梅花鹿(Cervus nippon Temminck)的鹿茸[初生期(PS)、快速生长期(RG)、骨化期(OS)鹿茸组织]作为实验材料,基于Illumina Hiseq和iTRAQ技术在转录和蛋白水平进行分析,根据差异基因和差异蛋白结果筛选与鹿茸再生和快速生长有关的基因和蛋白。结果2组分别得到11294(PSvsRG)和4924(PSvsOS)个显著差异基因(DEGs),2组的蛋白组数据显示,分别得到236、211个差异蛋白(DAPs),相关性分析显示转录组和蛋白组数据相关性分析呈弱相关。在2组中分别有54、51个DEGs编码了其相应的DAPs,其中,在2组中分别得到35和20个在转录组和蛋白组中调节方向相同的DEGs和相应的DAPs。对候选基因/蛋白进行KEGG富集分析,分别富集到10和12个信号通路。其中,2组共同富集到的通路包括:血管平滑肌收缩、p53信号通路、黏着斑、蛋白质消化吸收、TGF-β信号通路、ECM-受体相互作用信号通路。只富集到快速生长期的信号通路包括:戊糖磷酸途径、糖酵解/糖异生、果糖和甘露糖代谢及代谢途径。只富集到骨化期的信号通路包括:破骨细胞分化、肌动蛋白细胞骨架的调节、紧密连接、RNA转运、mRNA监测途径信号通路。共有10个候选基因/蛋白(CALD1、THBS2S、COL9A、ALDO、COL1A、HSPG2、SIRPA、CSRP、MYH9、H1-5)注释到上述信号通路。结论在鹿茸生长发育期间许多基因和蛋白质在鹿茸快速生长期和骨化期表现出不同的丰度。转录组和蛋白组数据相关性较差。筛选出与鹿茸生长发育相关的蛋白为:CALD1、THBS2S、COL9A、ALDO、COL1A、HSPG2、SIRPA、CSRP、MYH9、H1-5以上结果为阐明鹿茸再生的分子机制提供了重要的理论依据。

Distance protection of EHV long transmission lines considering compensation degree of shunt reactor

This study investigated the feasibility of distance protection in extra-high voltage(EHV) networks. In long-distance transmission lines, the distributed parameter characteristic of the EHV network is obvious. When a fault occurs far away from the measurement site, the measured impedance might not be directly proportional to the fault distance, and the protection domain of distance protection will be decreased. The detailed theory inferred and proven in this paper reveals that this phenomenon is widespread in EHV transmission lines. The results indicate that the protection domain error is greatly reduced by the application of the shunt reactor. Overall, simulation results show that the proposed method is effective for impedance relay, considering different characteristics, different lengths of lines, and compensation degrees.