Functional characterization of sensory neuron membrane protein 1a involved in sex pheromone detection of Apolygus lucorum(Hemiptera:Miridae)

The mirid bug Apolygus lucorum(Hemiptera:Miridae)is a polyphagous pest that affects a wide range of host plants.Its control remains challenging mainly due to its rapid reproduction,necessitating an understanding of sex pheromone communication.The recognition of sex pheromones is vital for courtship and mating behaviors,and is mediated by various chemosensory-associated proteins.Among these,sensory neuron membrane protein(SNMP),a CD36-related protein,is suggested to play crucial roles in detecting sex pheromones.In this study,we employed transcriptomic and genomic data from A.lucorum and phylogenetic approaches,and identified four putative SNMP genes(AlucSNMP1a,AlucSNMP1b,AlucSNMP2a,and AlucSNMP2b)with full open reading frames.Expression analysis revealed the ubiquitous presence of AlucSNMP transcripts in multiple tissues,with only AlucSNMP1a exhibiting male-biased expression in the antennae,suggesting its potential role in male chemosensation.Functional analysis using the Xenopus oocyte expression system,coupled with two-electrode voltage clamp recording,demonstrated that the co-expression of AlucSNMP1a with specific pheromone receptors(PRs)and the Odorant receptor co-receptor(Orco)significantly enhanced electrophysiological responses to sex pheromones compared to the co-expression of PRs and Orco alone.Moreover,the results indicated that the presence of AlucSNMP1a not only affected the responsiveness to sex pheromones but also influenced the kinetics(activation and inactivation)of the induced signals.In contrast,the co-expression of AlucSNMP1b with AlucPR/Orco complexes had no impact on the inward currents induced by two pheromone compounds.An examination of the selective pressures on SNMP1 genes across 20 species indicated strong purifying selection,implying potential functional conservation in various insects.These findings highlight the crucial role of AlucSNMP1a in the response to sex pheromones.

Establishment of a system for screening and identification of novel bactericide targets in the plant pathogenic bacterium Xanthomonas oryzae pv. oryzae using Tn-seq and SPR

Xanthomonas spp. cause severe bacterial diseases. However, effective strategies for prevention and management of these diseases are scarce. Thus, it is necessary to improve the efficiency of control of diseases caused by Xanthomonas. In this study, Xanthomonas oryzae pv. oryzae(Xoo), which causes rice bacterial leaf blight, has been studied as a representative. A transposon insertion library of Xoo, comprising approximately 200,000 individual insertion mutants, was generated. Transposon sequencing data indicated that the mariner C9 transposase mapped at 35.7–36.4% of all potential insertion sites, revealing 491 essential genes required for the growth of Xoo in rich media. The results show that, compared to the functions of essential genes of other bacteria, the functions of some essential genes of Xoo are unknown, 25 genes might be dangerous for the Xanthomonas group, and 3 are specific to Xanthomonas. High-priority candidates for developing broad-spectrum, Xanthomonas-specific, and environment-friendly bactericides were identified in this study. In addition, this study revealed the possible targets of dioctyldiethylenetriamine using surface plasmon resonance(SPR) in combination with high performance liquid chromatography–mass spectrometry(HPLC–MS). The study also provided references for the research of some certain bactericides with unknown anti-bacterial mode of action. In conclusion, this study urged a better understanding of Xanthomonas,provided meaningful data for the management of bacterial leaf blight, and disclosed selected targets of a novel bactericide.

Boosting the cycling stability of all-solid-state lithium metal batteries through MOF-based polymeric protective layers

Solid-state electrolytes(SSEs)play a pivotal role in advancing next-generation lithium metal battery technology.However,they commonly encounter substantial interfacial resistance and poor stability when interfacing with lithium metal,hindering practical applications.Herein,we introduce a flexible metal-organic framework(MOF:NUS-6)-incorporated polymeric layer,denoted as NP,designed to protect the sodium superionic conductor(NASICON)-type Li_(1.3)Al_(0.3)Ti_(1.7)(PO_(4))_(3)(LATP)electrolyte from Li metal anodes.The NP matrix establishes a soft interface with the LATP surface,effectively reducing voids and gaps that may arise between the LATP electrolyte and Li metal.Moreover,the MOF component in NP enhances ionic conductivity,offers abundant Li^(+)transport sites,and provides hierarchical ion channels,ensuring a homogeneous Li^(+)flow and thus effectively inhibiting Li dendrite formation.Utilizing NP,we fabricate Li symmetrical cells cycled for over 1600 h at 0.2 mA cm^(-2)and all-solid-state LiINP-LATPI LiFePO_(4)batteries,achieving a remarkable 99.3%capacity retention after 200 cycles at 0.2 C.This work outlines a general strategy for designing long-lasting and stable solid-state Li metal batteries.

Impact of Co^(2+)substitution on structure and magnetic properties of M-type strontium ferrite with different Fe/Sr ratios

Ion substitution has significantly improved the performance of ferrite magnets,and cobalt remains a key area of research.Studies on the mechanism of Co^(2+)in strontium ferrite,especially SrFe_(2n-x)Co_(x)O_(19-d)(n=6.1-5.4;x=0.05-0.20)synthesized using the ceramic method,showed that Co^(2+)preferentially enters the lattice as the Fe/Sr ratio decreases.This results in a decrease in the lattice constants a and c due to oxygen vacancies and iron ion deficiency.The impact of Co substitution on morphology is minor compared to the effect of the Fe/Sr ratio.As the Fe/Sr ratio decreases and the Co content increases,the saturation magnetization decreases.The magnetic anisotropy field exhibits a nonlinear change,generally increasing with higher Fe/Sr ratios and Co content.These changes in the performance of permanent magnets are attributed to the absence of Fe^(3+)ions at the 12k+2a and 2b sites and the substitution of Co^(2+)at the 2b site.This suggests that by adjusting the Fe/Sr ratio and appropriate Co substitution,the magnetic anisotropy field of M-type strontium ferrite can be effectively optimized.

Analysis of Intraspecies Diversity of Rice Reveals Variation Patterns of Oryza sativa Basic Leucine Zippers

The basic leucine zipper(bZIP)is an important class of transcription factors in plants,playing a critical role in plant growth and development and responses to biotic and abiotic stress.Due to gene presence/absence variations,it is limited to identify bZIP genes based on the reference genome.Therefore,we performed the bZIP gene family analysis in the rice pan-genome.By employing a rice pan-genome,ninety-four OsbZIPs(72 core genes and 22 variable genes)were identified and divided into 11 groups in a phylogenetic tree.Based upon Ka/Ks values in 33 accessions,OsbZIPs were subjected to different selection pressures during domestication.The analysis of the effects of structural variations(SVs)on gene expression,gene structure,and conserved domains showed that SVs could significantly alter the expression levels of certain OsbZIPs,leading to gene truncation and the emergence of numerous atypical genes.Thirty-four differentially expressed OsbZIPs were identified by analyzing RNA-seq data of the Xanthomonas oryzae pv.oryzae(Xoo)infection susceptible(IR24)and resistant(IRBB67)lines under high temperature,and by counting the number of differentially expressed OsbZIPs in different subgroups.These Osb-ZIPs were found to respond to Xoo infection at an early stage and may not be involved in the mechanism of Xa4 and Xa7 resistance to Xoo.The multiple variation patterns of OsbZIP genes provide new insights into the OsbZIP genes in rice.These results provide new resources and offer new directions for functional studies of OsbZIPs.

An Analysis of Supply Chain Environment in Great Wall Motor Based on Life-Cycle Assessment

Great Wall Motor(GWM),a leading automotive manufacturer,places a strong emphasis on environmental sustainability and social responsibility.The company focuses on comprehensively evaluating and enhancing its supply chain to align with these objectives.This evaluation spans the entire product life cycle,encompassing design,manufacturing,packaging,distribution,usage,and recycling and disposal processes.Key areas of focus include optimizing raw material selection,improving product recyclability,reducing energy consumption and waste emissions,and minimizing carbon emissions during transportation.Through these endeavors,GWM not only enhances its environmental performance by reducing carbon emissions and resource consumption but also bolsters its brand image and competitiveness in the market.GWM’s dedication to environmental innovation and technological leadership serves as a driving force behind sustainable development and social responsibility within the industry.

Single-cell analyses reveal cannabidiol rewires tumor microenvironment via inhibiting alternative activation of macrophage and synergizes with anti-PD-1 in colon cancer

Colorectal tumors often create an immunosuppressive microenvironment that prevents them from responding to immunotherapy.Cannabidiol(CBD)is a non-psychoactive natural active ingredient from the cannabis plant that has various pharmacological effects,including neuroprotective,antiemetic,anti-inflammatory,and antineoplastic activities.This study aimed to elucidate the specific anticancer mechanism of CBD by single-cell RNA sequencing(scRNA-seq)and single-cell ATAC sequencing(scATAC-seq)technologies.Here,we report that CBD inhibits colorectal cancer progression by modulating the suppressive tumor microenvironment(TME).Our single-cell transcriptome and ATAC sequencing results showed that CBD suppressed M2-like macrophages and promoted M1-like macrophages in tumors both in strength and quantity.Furthermore,CBD significantly enhanced the interaction between M1-like macrophages and tumor cells and restored the intrinsic anti-tumor properties of macrophages,thereby preventing tumor progression.Mechanistically,CBD altered the metabolic pattern of macrophages and related anti-tumor signaling pathways.We found that CBD inhibited the alternative activation of macrophages and shifted the metabolic process from oxidative phosphorylation and fatty acid oxidation to glycolysis by inhibiting the phosphatidylinositol 3-kinase-protein kinase B signaling pathway and related downstream target genes.Furthermore,CBD-mediated macrophage plasticity enhanced the response to anti-programmed cell death protein-1(PD-1)immunotherapy in xenografted mice.Taken together,we provide new insights into the anti-tumor effects of CBD.

铋基材料光催化还原水中六价铬的研究进展

光催化还原是处理水溶液体系中六价铬(Cr(VI))的一种新方法.层状铋(Bi)基材料具有增强的光捕获能力和可调的带隙能量,被认为是一种光催化还原去除Cr(VI)的有效材料.本文从修饰策略(如异质结、缺陷工程和掺杂)和工艺变量(如溶液p H和添加剂的类型/数量)等方面,对用于光催化还原处理Cr(VI)的铋基材料的改进机制进行深入总结.此外,采用工业上用作关键指标的优值系数(FoM),对各种铋基材料的性能进行评估.结果发现,平均粒径为5-10 nm,具有shuriken形状的BiVO_(4)具有最高的FoM值(3.45×10^(-5) molg^(-1)Wh^(-1)),且其光催化还原性能最好.同时,与其他非铋基催化剂相比,BiVO_(4)的光催化还原Cr(VI)性能也具有很好的优势.但是,目前铋基催化剂成本较高,且光催化还原过程能耗较大,距离大规模实际应用还有一定的距离.未来,为实现铋基催化剂光催化还原处理含Cr(VI)废水的大规模应用,应大幅度降低催化剂的生产成本,并提高催化剂光子吸收效率从而进一步提高能源利用率.

Electrochemical synthesis of FeN_(x) doped carbon quantum dots for sensitive detection of Cu^(2+) ion

A novel strategy was developed to fabricate FeNx-doped carbon quantum dots(Fe-N-CQDs)to detect Cu^(2+) ions selectively as a fluorescence probe.The Fe-N-CQDs were synthesized by an efficient electrolysis of a carbon cloth electrode,which was coated with monoatomic ironanchored nitrogen-doped carbon(Fe-N-C).The obtained Fe-N-CQDs emitted blue fluorescence and possessed a quantum yield(QY)of 7.5%.An extremely wide linear relationship between the Cu^(2+) concentration and the fluorescence intensity was obtained in the range from 100 nmol L^(-1) to 1000 nmol L^(-1)(R^(2)=0.997),and the detection limit was calculated as 59 nmol L^(-1).Moreover,the Fe-N-CQDs demonstrated wide range pH compatibility between 2 and 13 due to the coordination between pyridine nitrogen and Fe^(3+),which dramatically reduced the affection of the protonation and deprotonation process between H^(+) and Fe-N-CQDs.It is notable that the Fe-N-CQDs exhibited a rapid response in Cu^(2+) detection,where stable quenching can be completed in 7 s.The mechanism of excellent selective detection of Cu^(2+) was revealed by energy level simulation that the LUMO level of Fe-N-CQDs(-4.37 eV)was close to the redox potential of Cu^(2+),thus facilitating the electron transport from Fe-N-CQDs to Cu^(2+).

Optically pumped wavelength-tunable lasing from a GaN beam cavity with an integrated Joule heater pivoted on Si

Dynamically tunable laser sources are highly promising for realizing visionary concepts of integrated photonic circuits and other applications. In this paper, a Ga N-based laser with an integrated PN junction heater on Si is fabricated.The photoluminescence properties of the Ga N beam cavity are controlled by temperature, and the Joule heater provides electrically driven regulation of temperature. These two features of the cavity make it possible to realize convenient tuning of the lasing properties. The multi-functional Ga N beam cavity achieves optically pumped lasing with a single mode near 362.4 nm with a high Q-factor of 1394. The temperature of this device increases by 0–5℃ under the Joule heating effect. Then, electrical control of the lasing mode is demonstrated. The lasing resonant peak shows a continuous redshift of about 0.5 nm and the device also exhibits dynamic switching of its lasing mode. The lasing modulation can be ascribed to temperature-induced reduction of the bandgap. Our work may be of benefit for external optical modulation in future chip-based optoelectronic devices.

Canonical transient receptor potential channel 1 aggravates myocardial ischemia-and-reperfusion injury by upregulating reactive oxygen species

The canonical transient receptor potential channel(TRPC)proteins form Ca^(2+)-permeable cation channels that are involved in various heart diseases.However,the roles of specific TRPC proteins in myocardial ischemia/reperfusion(I/R)injury remain poorly understood.We observed that TRPC1 and TRPC6 were highly expressed in the area at risk(AAR)in a coronary artery ligation induced I/R model.Trpc1/mice exhibited improved cardiac function,lower serum Troponin T and serum creatine kinase level,smaller infarct volume,less fibrotic scars,and fewer apoptotic cells after myocardial-I/R than wild-type or Trpc6/mice.Cardiomyocyte-specific knockdown of Trpc1 using adeno-associated virus 9 mitigated myocardial I/R injury.Furthermore,Trpc1 deficiency protected adult mouse ventricular myocytes(AMVMs)and HL-1 cells from death during hypoxia/reoxygenation(H/R)injury.RNA-sequencing-based transcriptome analysis revealed differential expression of genes related to reactive oxygen species(ROS)generation in Trpc1/cardiomyocytes.Among these genes,oxoglutarate dehydrogenase-like(Ogdhl)was markedly downregulated.Moreover,Trpc1 deficiency impaired the calcineurin(CaN)/nuclear factorkappa B(NF-kB)signaling pathway in AMVMs.Suppression of this pathway inhibited Ogdhl upregulation and ROS generation in HL-1 cells under H/R conditions.Chromatin immunoprecipitation assays confirmed NF-kB binding to the Ogdhl promoter.The cardioprotective effect of Trpc1 deficiency was canceled out by overexpression of NF-kB and Ogdhl in cardiomyocytes.In conclusion,our findings reveal that TRPC1 is upregulated in the AAR following myocardial I/R,leading to increased Ca^(2+) influx into associated cardiomyocytes.Subsequently,this upregulates Ogdhl expression through the CaN/NF-kB signaling pathway,ultimately exacerbating ROS production and aggravating myocardial I/R injury.

Tanshinone IIA protects intestinal epithelial cells from ferroptosis through the upregulation of GPX4 and SLC7A11

Background:Inflammatory bowel disease(IBD)is a chronic inflammatory disease of the gastrointestinal tract.The destruction of the intestinal epithelial barrier is one of the major pathological processes in IBD pathology.Growing evidence indicated that epithelial cell ferroptosis is linked to IBD and is considered a target process.Methods:RAS-selective lethal 3(RSL3)was used to induce ferroptosis in intestinal epithelial cell line No.6(IEC-6)cells,and cell ferroptosis and the effects of tanshinone IIA(Tan IIA)were determined by cell counting kit-8(CCK-8),reactive oxygen species(ROS)staining,Giemsa staining and transmission electron microscope(TEM).The cell viability of natural product library compounds was determined by CCK-8.The expression of ferroptosis-related genes were detected by real-time quantitative polymerase chain reaction(RT-qPCR)and western blot.Results:Treatment of IEC-6 cells results in the accumulation of ROS and typical morphological characteristics of ferroptosis.RSL3 treatment caused rapid cellular cytotoxicity which could be reversed by ferrostatin-1(Fer-1)in IEC-6 cells.Natural product library screening revealed that Tan IIA is a potent inhibitor of IEC-6 cell ferroptosis.Tan IIA could significantly protect the RSL3-induced ferroptosis of IEC-6 cells.Furthermore,the ferroptosis suppressors,glutathione peroxidase 4(GPX4),solute carrier family 7 member 11(SLC7A11),and miR-17-92 were found to be early response genes in RSL3-treated cells.Treatment of IEC-6 cells with Tan IIA resulted in upregulation of GPX4,SLC7A11,and miR-17-92.Conclusion:Our study demonstrated that Tan IIA protects IEC-6 cells from ferroptosis through the upregulation of GPX4,SLC7A11,and miR-17-92.The findings might provide a theoretical grounding for the future application of Tan IIA to treat or prevent IBD.

The extracellular secretion of miR-1825 wrapped by exosomes increases CLEC5A expression:A potential oncogenic mechanism in ovarian cancer

Background:Ovarian cancer(OC)is a leading cause of gynecological cancer-linked deaths worldwide.Exosomal miR-1825 and its target gene C-type lectin domain family 5 member A(CLEC5A)are associated with tumorigenesis in cancers that was further probed.Methods:Exosomal miR-1825 expression in exosomes and its impact on overall survival(OS)prediction were determined using Gene Expression Omnibus(GEO)and The Cancer Genome Atlas(TCGA)data.Target genes of miR-1825 were searched in five prediction databases and prognostically significant differentially expressed genes were identified.Gene Ontology(GO)and Kyoto Encyclopedia of Genes and Genomes(KEGG)enrichment analyses were carried out.The ability of CLEC5A to predict OS was evaluated using univariate and multivariate Cox regression analyses and Kaplan-Meier curves.The CLEC5A expression pattern in OC was validated using immunohistochemistry.The CIBERSORT algorithm was used to compare the immune cell landscape,and the results were validated in a GEO cohort.Finally,the predicted half maximal inhibitory concentration(IC50)values for five commonly used chemotherapy agents were also compared.Results:MiR-1825 level was higher in exosomes derived from OC cells and served as a tumor suppressor.The CLEC5A gene was found to be a target of miR-1825,the upregulation of which was correlated with a poor prognosis.M2 macrophage infiltration was significantly enhanced in the CLEC5A high expression group,while T follicular helper cell infiltration was reduced in it.While the predicted IC50 for cisplatin and doxorubicin was higher in the CLEC5A high expression group,that of docetaxel,gemcitabine,and paclitaxel was lower.Conclusion:MiR-1825,a promising OC biomarker,may promote OC progression by increasing CLEC5A expression via exosome-mediated efflux from tumor cells.

The antioxidant trolox inhibits aging and enhances prostaglandin E-2 secretion in mesenchymal stem cells

Mesenchymal stem cells(MSCs)have been widely used in regenerative medicine and clinical therapy due to their capabilities of proliferation,differentiation,and immune regulation.However,during in vitro expansion,MSCs are prone to aging,which largely limits their application.Prostaglandin E-2(PGE-2)is a key effector secreted by MSCs to exert immunomodulatory effects.By screening the compound library for PGE-2 secretion,the antioxidant trolox was verified as a stimulator of MSCs to secrete PGE-2.The effect of antioxidant trolox on biological characteristics of MSCS,including aging,proliferation,and gene expression,was examined.The results demonstrated that trolox can resist aging,promote proliferation,and enhance PGE-2 secretion of MSCs without affecting their surface marker expression.Furthermore,trolox treatment up-regulates miR-17-92 clusters in MSCs and may contribute to its anti-aging effects.Thus,trolox addition might be beneficial for MSCs expansion and their application.

Traffic Sign Recognition Based on CNN and Twin Support Vector Machine Hybrid Model

With the progress of deep learning research, convolutional neural networks have become the most important method in feature extraction. How to effectively classify and recognize the extracted features will directly affect the performance of the entire network. Traditional processing methods include classification models such as fully connected network models and support vector machines. In order to solve the problem that the traditional convolutional neural network is prone to over-fitting for the classification of small samples, a CNN-TWSVM hybrid model was proposed by fusing the twin support vector machine (TWSVM) with higher computational efficiency as the CNN classifier, and it was applied to the traffic sign recognition task. In order to improve the generalization ability of the model, the wavelet kernel function is introduced to deal with the nonlinear classification task. The method uses the network initialized from the ImageNet dataset to fine-tune the specific domain and intercept the inner layer of the network to extract the high abstract features of the traffic sign image. Finally, the TWSVM based on wavelet kernel function is used to identify the traffic signs, so as to effectively solve the over-fitting problem of traffic signs classification. On GTSRB and BELGIUMTS datasets, the validity and generalization ability of the improved model is verified by comparing with different kernel functions and different SVM classifiers.

Experimental study of Quercetin self-nanoemulsifying drug delivery system in inhibiting SMMC-7721 cells

Objective： To study the mechanism of inhibition of SMMC-7721 liver cancer cells by quercetin self-nanoemulsifying drug delivery system （Q-SNEDDS） in vitro. Methods： The inhibitory effect of Q-SNEDDS on hepatoma cells was detected by MTT assay. The effect of Q-SNEDDS on apoptosis of hepatoma cells was detected by flow cytometry. The changes of Q-SNEDDS after hepatoma cells were observed by fluorescence microscopy. The effect of Q-SNEDDS on the expression of signal tra_nsduction and activator of transcription 3 （STAT3） and a_nti-apoptotic factor （survivin） protein in hepatoma cells was examined by Immunohistochemistry. Results： Q-SNEDDS significantly inhibited the proliferation of hepatoma cells in a concentration-dependent manner. After 24 h of Q-SNEDDS treatment, the total apoptosis rate was 25.8%; STAT3 and survivin protein expression was down-regulated in the Q-SNEDDS group. Conclusion： Q-SNEDDS may play a role in inducing apoptosis by inhibiting the expression of STAT3 and survivin proteins.

骨纤维结构不良恶变的病例对照研究

目的:分析骨纤维结构不良(fibrous dysplasia,FD)恶变的生物学行为,探讨恶变诊断的危险因素。方法:回顾性分析北京积水潭医院2006年3月至2017年3月收拾的FD 394例,病理学证实恶变7例为研究组。根据恶变病例的年龄、部位等流行病学资料,按照1:2配对分析同期FD 14例为对照组。对比临床特点、疼痛VAS评分、病灶大小、影像学特征、血液生化指标、随访肿瘤学结果及功能评分进行统计学分析。结果:FD恶变7例,其中男性3例,女性4例。平均随访时间为175(3～396)个月,恶变后平均随访时间为26(3～51)个月。平均和中位年龄分别为45.6岁和47(24～60)岁,其中股骨6例,胫骨1例。2例为单发病灶,5例为全身多发纤维结构不良,2例为初次手术,5例为复发后确诊,恶变距初次手术间隔平均时间为207(37～377)个月。研究组的疼痛(visual analogue scale/score,VAS)评分较对照组显著增高(Z=-3.317,P=0.001),且研究组术后VAS较术前明显改善(Z=-2.384,P=0.017)。研究组较对照组术前碱性磷酸酶(alkline phosphatase,AKP)对比明显增高(Z=-2.314,P=0.021),术前乳酸脱氢酶(lac-tate dehydrogenase,LDH)(Z=-1.269,P=0.205)两组比较均无显著性差异。研究组术后AKP较术前明显下降(Z=-2.366,P=0.018),术后LDH较术前下降(Z=-2.028,P=0.043)。CT扫描发现研究组增强后CT值明显高于对照组增强后CT值(Z=-3.659,P<0.001)。单因素分析表明术前VAS评分、AKP值、皮质破坏、软组织包块和CT增强值5项因素在判断FD恶变具有临床意义。恶变病理分别为骨肉瘤4例,低级别梭形细胞肉瘤2例,未分化多形性肉瘤1例,3例患者接受辅助化疗,2例出现肺转移,1例死亡。术后功能MSTS评分,对照组平均95.0%±3.9%,功能优于研究组86.0%±10.9%(F=5.689,P=0.029)。结论:FD恶变罕见,术前VAS评分、AKP值、皮质破坏、是否存在软组织包块以及CT增强值有助于临床判断是否恶变;广泛外科边界切除为主要治疗方法。

高效液相色谱法检测发酵液中四氢嘧啶及羟基四氢嘧啶

为实现发酵液样品中四氢嘧啶和羟基四氢嘧啶的分离检测,使用高效液相色谱(HPLC)技术建立一种测定中度嗜盐菌发酵液中四氢嘧啶及羟基四氢嘧啶含量的方法。使用乙醇抽提法提取样品,采用Vertex^(TM) NH_(2)(4.6×250 mm,5μm)液相色谱柱对中度嗜盐菌发酵液中四氢嘧啶及四氢嘧啶进行了分析,选用紫外(UV)检测器,对比不同检测条件。通过色谱条件优化,选定了70%乙腈作为流动相,柱温30℃,检测波长210 nm,流速0.8 mL/min。发酵液样品中四氢嘧啶和羟基四氢嘧啶在各自范围内线性关系良好,两种样品的平均回收率在99.2%~102%,精密度偏差在1%~2%范围内,检出限为1.5μg/mL,定量限为5μg/mL,分离度为1.70。该方法检测范围大,具有较好的重复性、分离度及稳定性,适用于发酵液中四氢嘧啶及羟基四氢嘧啶的分离检测。

基于UG的混凝土运输车搅拌叶片参数化设计

为提高混凝土运输车的出料性能和搅拌性能,结合搅拌叶片的对数螺旋线参数方程,对Unigraphics NX软件中的UG-OPEN-GRIP模块进行二次开发编程得到搅拌叶片对数螺旋曲线参数化设计。在对螺旋曲线进行光顺性检查后,建立各截面的辅助面并生成叶片曲面。利用尺寸驱动技术,可以方便地对叶片截形进行再修改。

CTRP9对心血管保护作用的研究进展

补体1q肿瘤坏死因子相关蛋白(CTRP)9是CTRP蛋白家族重要成员,与脂联素高度同源,结构相似。近几年发现CTRP9在动脉粥样硬化、缺血性心脏病(IHD)等心血管疾病中作用广泛。除了经典的调节糖脂代谢、调节内皮功能外,最近的研究显示外源性补充CTRP9能够对缺血心肌发挥保护作用,而且CTRP9在心脏局部特异性高表达,可能是一种重要的心脏因子,参与调节心肌局部微环境,发挥心肌保护作用,本文将就CTRP9在心血管保护方面的研究进展进行综述。