有机化学实验教学与安全教育融合实践——以三苯甲醇合成实验为例

有机化学实验流程繁琐,使用的仪器设备与试剂种类多。传统的实验室安全教育在实验危险源辨识方面有所欠缺。以三苯甲醇合成实验为例,我们把实验操作分解成多个步骤,引导学生辨识每一步操作涉及的危险源,与学生分享相关的典型案例,并借由事故危害强化学生对实验安全的重视。通过不同实验项目中反复实操危险源辨识,学生熟练掌握了化学合成实验通用危险源的安全操作,并能在新实验中主动分析危险源,做好个人防护,严格执行安全操作规程。

Core clock component MtLUX controls shoot architecture through repression of MtTB1/MtTCP1A in Medicago truncatula

Plants are capable of regulating their shoot architecture in response to diverse internal and external environments.The circadian clock is an adaptive mechanism that integrates information from internal and ambient conditions to help plants cope with recurring environmental fluctuations.Despite the current understanding of plant circadian clock and genetic framework underlying plant shoot architecture,the intricate connection between these two adaptive mechanisms remains largely unclear.In this study,we elucidated how the core clock gene LUX ARRHYTHMO(LUX)regulates shoot architecture in the model legume plant Medicago truncatula.We show that mtlux mutant displays increased main stem height,reduced lateral shoot length,and decreased the number of lateral branches and biomass yield.Gene expression analysis revealed that Mt LUX regulated shoot architecture by repressing the expression of strigolactone receptor MtD14 and MtTB1/MtTCP1A,a TCP gene that functions centrally in modulating shoot architecture.In vivo and in vitro experiments showed that Mt LUX directly binds to a cis-element in the promoter of MtTB1/MtTCP1A,suggesting that Mt LUX regulates branching by rhythmically suppressing MtTB1/MtTCP1A.This work demonstrates the regulatory effect of the circadian clock on shoot architecture,offering a new understanding underlying the genetic basis towards the flexibility of plant shoot architecture.

Probiotics supplementation for management of type Ⅱ diabetes risk factors in adults with polycystic ovarian syndrome: a meta-analysis of randomized clinical trial

This meta-analysis of randomized controlled trials aimed to evaluate the effects of probiotic supplementation on glucose homeostasis in patients with polycystic ovary syndrome(PCOS).The meta-analysis was performed in accordance with the Cochrane Handbook guidelines and relevant the preferred reporting items for systematic reviews and meta-analyses(PRISMA)statement criteria.Of 825 identified reports,11 randomized clinical trials were included in the meta-analysis.An analysis of pooled extracted data revealed that supplementation with probiotics significantly decreased fasting blood glucose(FBG,n=7;standardized mean difference(SMD)=−0.40;95%confidence interval(CI):−2.02,−0.02;P=0.04)and insulin levels(n=6;SMD=−0.57;95%CI:−0.89,−0.25;P=0.0004)and the homeostatic model assessment of insulin resistance(n=7;SMD=−0.64;95%CI:−0.96,−0.31;P=0.0001)while increasing the quantitative insulin sensitivity check index(QUICKI,n=5;SMD=0.58;95%CI:0.08,1.09;P=0.02)in patients with PCOS.The FBG-reducing effect decreased as the baseline body mass index(BMI)and mean age of the participants increased.Indeed,a greater number of bacterial species and a higher bacterial dose were shown to reduce QUICKI effectively.The systematic review indicated that probiotic supplementation may help to control glucose homeostasis in adults with polycystic ovarian syndrome.

基于氢键诱导理论的有机化学探索实验:(+/-)-2-亚甲基香茅醛的合成与快速鉴定

本实验用吡咯烷和4-二甲基氨基苯甲酸作为有机小分子催化剂,催化天然香料(+/-)-香茅醛与甲醛的Aldol缩合反应并脱水合成(+/-)-2-亚甲基香茅醛。基于小分子催化的氢键诱导效应,我们选用二氯甲烷、四氢呋喃、无水乙醇三种溶剂进行平行反应,用薄层色谱法监控平行反应的转化速度,筛选相对最佳反应溶剂。同时,我们用共振离域理论解释原料和产物在核磁共振化学位移、薄层色谱比移值、液相色谱保留时间的差异。本实验弥补了有机化学实验在反应条件优化方面的空白。

应用Suzuki偶联反应学习Hammett方程的实验教学设计

介绍了一个有机化学综合创新实验——应用Suzuki偶联反应来学习Hammett方程的实验教学方案。通过探究不同取代基底物对Suzuki偶联反应速率的影响,进一步得出Hammett方程的关系曲线图,结果表明苯硼酸上的吸电子取代基使反应速率减慢,而给电子取代基会加快反应速率,探索了Suzuki偶联反应中转金属化过程对偶联反应的影响。在进行文献调研、实验设计、实验操作、结果分析和报告撰写的过程中,学生既能学习Suzuki偶联反应的基本原理,更重要的是理解Hammett方程的意义,激发学生对有机化学的科研兴趣,提升学生综合素质。

三全育人背景下的多维度大学化学实验课程思政建设

针对大学化学实验课程的特点,从课程教学目标设计、实验教学活动设计和课程教学成果评价三个方面,探索教学过程中专业知识与思政元素的结合点。分别从培养学生的爱国情怀、科学素养、创新意识、职业素养、社会责任感、辩证思维和绿色发展理念等多个维度介绍在大学化学实验教学过程中实施思政教育的具体措施。利用好课堂教学的主渠道,将知识探究、能力建设和价值塑造三者融为一体,推进全员全程全方位育人的重要实践,培养学生成为德智体美劳全面发展的新时代社会主义建设者和接班人。

基于Landsat-8 OLI影像的黔西北高原地表水体提取方法研究

快速准确的地表水体信息获取,对于研究区域水体时空变化具有重要意义。以黔西北高原区域为研究区,利用Landsat-8 OLI影像为数据源,基于单波段阈值法、多波段谱间关系法、NDWI等分类方法,对研究区水体信息进行提取。结果表明:(1)多指数与谱间关系法相结合的决策树方法提取效果最佳,Kappa系数到达0.860。(2)单波段阈值法、NDVI和NDWI的误分和漏分情况比较严重;多指数与谱间关系法相结合的决策树分类方法水体信息提取效果最佳。(3)从总体精度上看,多波段谱间关系法和多指数与谱间关系法相结合的决策树效果最好。

mTORC1 induces plasma membrane depolarization and promotes preosteoblast senescence by regulating the sodium channel Scn1a

Senescence impairs preosteoblast expansion and differentiation into functional osteoblasts,blunts their responses to bone formation-stimulating factors and stimulates their secretion of osteoclast-activating factors.Due to these adverse effects,preosteoblast senescence is a crucial target for the treatment of age-related bone loss;however,the underlying mechanism remains unclear.We found that mTORC1 accelerated preosteoblast senescence in vitro and in a mouse model.Mechanistically,mTORC1 induced a change in the membrane potential from polarization to depolarization,thus promoting cell senescence by increasing Ca^(2+)influx and activating downstream NFAT/ATF3/p53 signaling.We further identified the sodium channel Scn1a as a mediator of membrane depolarization in senescent preosteoblasts.Scn1a expression was found to be positively regulated by mTORC1 upstream of C/EBPα,whereas its permeability to Na^(+)was found to be gated by protein kinase A(PKA)-induced phosphorylation.Prosenescent stresses increased the permeability of Scn1a to Na^(+)by suppressing PKA activity and induced depolarization in preosteoblasts.Together,our findings identify a novel pathway involving mTORC1,Scn1a expression and gating,plasma membrane depolarization,increased Ca^(2+)influx and NFAT/ATF3/p53 signaling in the regulation of preosteoblast senescence.Pharmaceutical studies of the related pathways and agents might lead to novel potential treatments for agerelated bone loss.

CHK21100delC, I157T, IVS2 +IG >A, BRCA1 and BRCA2 Mutation Analysis in JF305: A Pancreatic Cancer Cell Line

JF305 is a highly prolific pancreatic cancer cell line that originated from a Chinese patient. The cell line bears a functional HR double strand DNA repair mechanism but very responsive to PARP treatment a phenomenon clearly suggesting presence of an anomaly in the mechanism. Brca1, Brca2 and CHK2 proteins are very important constituents of the HR mechanism whose respective gene coding mutations are strongly associated with several cancers and are widely exploited in anticancer chemotherapy. In this current study, the BRCA1, BRCA2 gene mutation status in JF305 was determined together with the presence of 3 widely reported cancer linked CHK2 founder mutations (1100delC, I157T, IVS2 +IG > A). CHK21100delC genotype was determined using allele specific PCR, while the PCR-RFLP assay was used for I157T, IVS2 +IG > A analysis. PCR and direct sequencing were used for assessing the BRCA1 and BRCA2 gene. Results revealed that JF305 is CHK21100delC heterozygous mutant, CHK2I157T and CHK2IVS2 +IG > A wild type. Furthermore, it was observed that JF305 lacked BRCA1 and BRCA2 gene mutations. The mutation status identification of CHK2 and BRCA1/2 in JF305 provides a major milestone towards elucidating the properties of the cell line which subsequently promises to be an excellent model for evaluating the role of parp inhibitors in pancreatic cancer chemotherapy most especially in the respective cancer cell lines without BRCA1 and BRCA2 gene mutations.

Gemcitabine and Doxorubicin Combination Enhance the Cytotoxic Effect to Pancreatic Cancer Cells BxPC3 and PANC1 through UMP/CMP Kinase 1

Background: Gemcitabine is a deoxycytidine analog, which is used as first-line agent for pancreatic cancer therapy, and its efficacy relied on its intracellular conversion to active triphosphate form. However, administration with gemcitabine still has limited effect on the overall survival of patients with pancreatic cancer. Objective: We aimed to study the combination effect of gemcitabine and doxorubicin to pancreatic cancer cells BxPC3 and PANC1, and unveil the mechanism. Methods: The study was performed in pancreatic cancer cells PANC1 and BxPC3, the contribution of UMP/CMP kinase 1 (CMPK1) to gemcitabine in PANC1 and BxPC3 cells was measured by transfection of CMPK1 plasmid or CMPK1 siRNA treatment to adjust the expression of CMPK1 in the cells;then analyzed the cell vitality and migration after treated with 1% IC50 of doxorubicin and gemcitabine or only with gemcitabine;the activity of CMPK1 and the effect of doxorubicin to the reaction was measured by HPLC assay in vitro;at last, docking analysis by computer was used to calculate the possible interaction sites of CMPK1 to DOX. Results: The sensitivity of PANC1 and BxPC3 cells to gemcitabine was improved when increasing the expression of CMPK1, and decreased when knockout CMPK1 by CMPK1 siRNA in BxPC3 cells;when combined with doxorubicin, the sensitivity of PANC1 and BxPC3 cells to gemcitabine also increased, and the cells migration reduced;we further found out that by adding 10 μM doxorubicin, the catalyzing activity of CMPK1 elevated about 2 times in vitro;the docking result showed that the association of CMPK1 to DOX was mainly by hydrogen bond and ionic interaction. Conclusion: CMPK1 can catalyze gemcitabine to its active form within the cells so that the sensitivity of the cells to gemcitabine elevated, and doxorubicin may enhance the cytotoxic effect to pancreatic cancer by up-regulate the activity of CMPK1, the combination of these deoxycytidine analogs with DOX might exert better efficacy.

石漠化治理中农草林草空间优化配置技术研究

在石漠化治理过程中,需要合理优化配置农草林草空间来全面提升石漠化治理效果。介绍了农草林草空间配置的概念,分析了农草林草空间在石漠化治理过程中的优化配置方案,阐述其优化配置模式并提出具体的优化配置关键技术,希望能够为石漠化综合治理项目提供一些参考和借鉴。

Nearly lattice-defect-free MOF membranes

Membrane technology has widely accepted as the most energy efficient technology for the separation of ions or molecules. As the core of the membrane technology, the chemical and structure nature of membrane materials determines the application and energy-efficiency of the technology. An advanced membrane that has a remarkable ability to selectively differentiate ions and molecules can significantly enhance the separation technology and revolutionize industrial separation processes.

Characteristics of gas geochemistry in Yangbajing geothermal field, Tibet

CO 2 is a main component of gases in the Yangbajing geothermal field, usually higher than 85 in volume; others are N 2, H 2S, H 2, CH 4, etc. Helium R/R a ratios, ranging from 0.14 to 0.46, indicate a crustal component to be dominant in the gases. δ 13C-CO 2 values and δ 34S-H 2S values are in the range -7.72‰--11.33‰ and 0.2‰-8.3‰, respectively. The gases are inferred to mostly derive from the partial melting of the Nyainqentanglha core complex. The gases of shallow and deep reservoirs are distinctive in chemical compositions and δ 34S-H 2S values, which shows their different flowing paths and physical-chemical processes. Sulphur does not approach isotopic equilibrium between H 2S and SO 2- 4 species in both reservoirs. Significance of steam chemical monitoring is also discussed.

Rice domestication-associated transcription factor PROSTRATE GROWTH 1 controls plant and panicle architecture by regulating the expression of LAZY 1 and OsGIGANTEA,respectively

Plant architecture and panicle architecture are two critical agronomic traits that greatly affect the yield of rice(Oryza sativa).PROSTRATE GROWTH 1(PROG1)encodes a key C2H2-type zinc-finger transcription factor and has pleiotropic effects on the regulation of both plant and panicle architecture,thereby influencing the grain yield.However,the molecular mechanisms through which PROG1 controls plant and panicle architecture remain unclear.In this study,we showed that PROG1 directly binds the LAZY 1(LA1)promoter and acts as a repressor to inhibit LA1 expression.Conversely,LA1 acts as a repressor of PROG1 by directly binding to the PROG1 promoter.These two genes play antagonistic roles in shaping plant architecture by regulating both tiller angle and tiller number.Interestingly,our data showed that PROG1 controls panicle architecture through direct binding to the intragenic regulatory regions of OsGIGANTEA(OsGI)and subsequent activation of its expression.Collectively,we have identified two crucial targets of PROG1,LA1 and OsGI,shedding light on the molecular mechanisms underlying plant and panicle architecture control by PROG1.Our study provides valuable insights into the regulation of key domestication-related traits in rice and identifies potential targets for future high-yield rice breeding.

用于精准蛋白降解和癌症治疗的刺激响应型PROTAC进展

刺激响应型蛋白质降解靶向嵌合体(PROTAC)前药可在特定刺激条件下激活PROTAC分子,实现特定区域和细胞的靶蛋白降解,从而克服不可控蛋白降解导致的毒副作用,是改善PROTAC疗效和成药性的有效策略.本文系统总结了目前用于特异性降解病灶组织目标蛋白从而精准治疗肿瘤的各种刺激响应型PROTAC前药策略.首先,本文介绍了PROTAC的发展历程和作用原理,以及目前进入临床试验阶段的PROTAC分子;然后,介绍了细胞内原位生成PROTAC的前药策略,以及各种刺激手段激活的PROTAC前药,包括外源性的光、X-射线以及内源性的肿瘤微环境的乏氧、活性氧和酶等;接着,概括了配体修饰型的主动靶向PROTAC前药,包括抗体、叶酸、适配体等修饰策略.本文重点强调了基于纳米递药系统的PROTAC前药策略,其可实现特异性肿瘤组织药物递送和精准蛋白降解.最后,本文对PROTAC的未来发展进行了探讨和展望.

Machine learning-based spectral and spatial analysis of hyper-and multi-spectral leaf images for Dutch elm disease detection and resistance screening

Diseases caused by invasive pathogens are an increasing threat to forest health,and early and accurate disease detection is essential for timely and precision forest management.The recent technological advancements in spectral imaging and artificial intelligence have opened up new possibilities for plant disease detection in both crops and trees.In this study,Dutch elm disease(DED;caused by Ophiostoma novo-ulmi,)and American elm(Ulmus americana)was used as example pathosystem to evaluate the accuracy of two in-house developed high-precision portable hyper-and multi-spectral leaf imagers combined with machine learning as new tools for forest disease detection.Hyper-and multi-spectral images were collected from leaves of American elm geno-types with varied disease susceptibilities after mock-inoculation and inoculation with O.novo-ulmi under green-house conditions.Both traditional machine learning and state-of-art deep learning models were built upon derived spectra and directly upon spectral image cubes.Deep learning models that incorporate both spectral and spatial features of high-resolution spectral leaf images have better performance than traditional machine learning models built upon spectral features alone in detecting DED.Edges and symptomatic spots on the leaves were highlighted in the deep learning model as important spatial features to distinguish leaves from inoculated and mock-inoculated trees.In addition,spectral and spatial feature patterns identified in the machine learning-based models were found relative to the DED susceptibility of elm genotypes.Though further studies are needed to assess applications in other pathosystems,hyper-and multi-spectral leaf imagers combined with machine learning show potential as new tools for disease phenotyping in trees.

Concise Cascade Methods for Transgenic Rice Seed Discrimination using Spectral Phenotyping

Currently,the presence of genetically modified(GM)organisms in agro-food markets is strictly regulated by enacted legislation worldwide.It is essential to ensure the traceability of these transgenic products for food safety,consumer choice,environmental monitoring,market integrity,and scientific research.However,detecting the existence of GM organisms involves a combination of complex,time-consuming,and labor-intensive techniques requiring high-level professional skills.In this paper,a concise and rapid pipeline method to identify transgenic rice seeds was proposed on the basis of spectral imaging technologies and the deep learning approach.The composition of metabolome across 3 rice seed lines containing the cry1Ab/cry1Ac gene was compared and studied,substantiating the intrinsic variability induced by these GM traits.Results showed that near-infrared and terahertz spectra from different genotypes could reveal the regularity of GM metabolic variation.The established cascade deep learning model divided GM discrimination into 2 phases including variety classification and GM status identification.It could be found that terahertz absorption spectra contained more valuable features and achieved the highest accuracy of 97.04%for variety classification and 99.71%for GM status identification.Moreover,a modified guided backpropagation algorithm was proposed to select the task-specific characteristic wavelengths for further reducing the redundancy of the original spectra.The experimental validation of the cascade discriminant method in conjunction with spectroscopy confirmed its viability,simplicity,and effectiveness as a valuable tool for the detection of GM rice seeds.This approach also demonstrated its great potential in distilling crucial features for expedited transgenic risk assessment.

Microbial Fertilizer: A Sustainable Strategy for Medicinal Plants Production

Medicinal plants have aroused considerable interest as an alternative to chemical drugs due to the beneficial effects of their active secondary metabolites.However,the extensive use of chemical fertilizers and pesticides in pursuit of yield has caused serious pollution to the environment,which is not conducive to sustainable devel-opment in thefield of medicinal plants.Microbial fertilizers are a type of“green fertilizer”containing specific microorganisms that can improve the soil microbial structure,enhance plant resistance to biological and abiotic stresses,and increase the yield of medicinal plants.The root exudates of medicinal plants attract different micro-organisms to the rhizosphere,which then migrate further to the plant tissues.These microbes can increase the levels of soil nutrients,and improve the physical and chemical properties of soil through nitrogenfixation,and phosphorus and potassium solubilization.In addition,soil microbes can promote the synthesis of hormones that increase plant growth and the accumulation of active compounds,eventually improving the quality of med-icinal plants.In 2022,the total value of the global microbial fertilizer market was$4.6 billion and is estimated to reach$10.36 billion by 2030.In this review,we have summarized the types of microbial fertilizers,the coloniza-tion and migration of microorganisms to plant tissues,and the beneficial effects of microbial fertilizers.In addi-tion,the prospects of developing microbial fertilizers and their application for medicinal plants have also been discussed.It aims to provide a reference for the rational application of microbial fertilizers in thefield of med-icinal plants and the green and sustainable development of medicinal plant resources.

Chronic effects of different fertilization regimes on nirS-type denitrifier communities across the black soil region of Northeast China

Denitrification is one of the major processes causing nitrogen loss from arable soils.This study aimed to investigate the responses of nir S-type denitrifier communities to different chronic fertilization regimes across the black soil region of Northeast China.Soil samples were collected from sites located in the north(NB),middle(MB),and south(SB)of the black soil region of Northeast China,each with four chronic fertilization regimes:no fertilizer(No F),chemical fertilizer(CF),manure(M),and chemical fertilizer plus manure(CFM).Methods of quantitative polymerase chain reaction(q PCR)and Illumina Mi Seq sequencing were applied to assess the abundance and composition of denitrifier communities by targeting the nir S gene.The results showed that the M and CFM regimes significantly increased the abundances of nir S-type denitrifiers compared with No F at the three locations.The majority of nir S sequences were grouped as unclassified denitrifiers,and the different fertilizers induced little variation in the relative abundance of known nir S-type denitrifier taxa.Over 90%of the sequences were shared among the four fertilization regimes at each location,but none of the abundant operational taxonomic units(OTUs)were shared among the three locations.Principal coordinate analysis(PCo A)revealed that the communities of nir S-type denitrifier were separated into three groups that corresponded with their locations.Although similar fertilization regimes did not induce consistent changes in the nir S-type denitrifier communities,soil p H and NO-3-N content simultaneously and significantly influenced the structure of nir S-type denitrifier communities at the three locations.Our results highlight that geographical separation rather than chronic fertilization was the dominant factor determining the nir S-type denitrifier community structures,and similar chronic fertilization regimes did not induce consistent shifts of nir S-type denitrifier communities in the black soils.