基于拉曼技术的单细胞生长检测方法

目的 单细胞生长检测可以更加科学地揭示微生物代谢变化的规律,为后期微生物工程应用提供指导。针对微生物生长应用于食品安全期和最佳食用期的精准检测问题,本文提出一种基于拉曼技术的单细胞生长检测方法。方法 首先,通过同步培养实验采集了枯草芽孢杆菌两个批次共900个单细胞拉曼光谱（SCRS）数据,其中600个用于训练和测试,另一批次300个用于模型验证。其次,基于主成分分析的特征关系矩阵,提出CP-SP特征评估方法以筛选SCRS特征用于模型检测。再基于XGBoost构建检测模型,并应用网格搜索和交叉验证对检测模型进行调优。最后,应用混淆矩阵、ROC曲线评估模型对细胞滞后期、对数期和稳定期的检测准确率、敏感性和特异性。结果 选用CP-SP筛选的第一、第二和第四主成分较特征贡献率前3个主成分的分类性能提高了3.1%,调优后的细胞生长检测模型测试准确率为96.0%,验证准确率为92.3%。结论 基于拉曼技术的单细胞生长检测方法能准确识别单细胞生长状态且具有较高的泛化能力,可为食品安全和保鲜制定精准调控机制提供科学指导。     

安徽省清凉峰自然保护区植物区系的研究

清凉峰自然保护区有维管束植物181科,601属,1228种,是安徽植物资源集中地之一。区系成分起源古老,孑遗种多,保存着丰富的珍稀、濒危植物。种子植物区系地理成分复杂,各类热带成分、温带成分、中国特有成分分别占本区种子植物属总数的33.6%、62.96%、3.44%,显示了本区植物区系的亚热带特性。本区植物区系97.6%的成分与华东植物区系共有,且含华东特有种111种,具有典型华东植物区系特征。本区植物区系与西天目山、黄山植物区系关系最密切,其次为大别山和庐山,再次为神农架。     

天然产物抗氧化构效关系及作用机理的研究概况

本文简介了近十年来天然抗氧化剂的研究概况,讨论了天然产物抗争氧化活性的构效关系及作用机理。     

计算机虚拟筛选技术在害虫行为调节剂研究中的应用

害虫行为调节剂是一种以嗅觉系统为靶标的绿色农药,在害虫的田间管理中发挥着重要的作用。然而,其先导化合物的发现通常依赖一系列生物测定的方法,不仅费时费力,且发现效率低。近年来,随着昆虫嗅觉功能数据的积累和结构生物学的飞速发展,以机器学习技术和分子对接为代表的2种基于计算机的药物虚拟筛选方法在害虫行为调节剂的先导化合物研究中发挥着重要的作用,极大地促进了先导化合物的发现效率,减少了筛选的盲目性。本文系统综述了2种虚拟筛选方法及其在害虫行为调节剂先导化合物研究中的应用,并对2种筛选策略在实际应用中存在的问题及应用前景进行了讨论。     

Design,Synthesis, and Cytotoxic Activities of Indole and Indazole-Based Stilbenes

To develop new highly effective anticancer agents derived from naturally occurring stilbene scaffold, in total of 24 indole and indazole-based stilbenes including 17 new compounds were designed according to molecular hybridization strategy and synthesized via Witting reaction. The cytotoxic screening results against human tumor cell lines (K562 cells and MDA-MB-231 cells) showed that indole and indazole-based stilbenes are of great interest for developing anticancer agents as eight derivatives possessed strong antiproliferative activities with IC₅₀ values less than 10 μM, and those synthetic derivatives displayed more higher cytotoxicities against K562 cells than MDA-MB-231 cells. In particular, indole-based stilbene bearing piperidine exhibited the most potent cytotoxicities against both K562 and MDA-MB-231 cells with IC₅₀ values 2.4 μM and 2.18 μM, respectively, along with a remarkable selectivity towards human normal L-02 cells. Together, the results suggested that indole and indazole-based stilbenes are promising anticancer scaffolds worthy of further investigation.     

TAI系列Ⅱ天兰冰草染色体上的酯酶同工酶基因定位

本文分析了小冰麦异附加系列Ⅱ,八倍体小冰麦,普通小麦和天兰冰草的叶片酯酶（ESTL）,胚乳酯酶（ESTE）,根酯酶（ESTR）和胚芽鞘酯酶（ESTG）的酶谱表型。把冰草同工酶基因Estl-Ag1,Este-Agi1,Estr-Agij,Estc-Agi1,Estl-Agi2和Este-Agi2定位到异附加系TAI－23,把基因Estr-Agi4和Estc-Agi4定位到TAI－24中的冰草染色体上,根据这些基因定位,结合某些植株形态学特征,推测TAI－23和TAI－24中的冰草染色体分别与小麦第3和6同祖群有一定的部分同源关系。     

Structural Optimization,Fungicidal Activities Evaluation,DFT Study and Structure-Activity Relationship of Dopamine Derivatives with Benzothiazole Fragment from Polyrhachis dives

In our previous work, two dopamine derivatives with benzothiazole fragment were isolated and identified from Polyrhachis dives (P. dives). Based on their characteristic structure, we used them as lead compound to carry out structural optimization and subsequent fungicidal evaluation. Here 20 dopamine derivatives with benzothiazole fragment were designed and synthesized by a facile method, and their structures were characterized by ¹H-NMR, ¹³CNMR and HMRS. In bioassays, most of the title compounds possess potential fungicidal activities against Altenaia alternala (A. alternala) and Botrytis cinerea (B. cinerea). Especially, (E)-N-(2-(benzo[d]thiazol-6-yl)ethyl)-3-(p-tolyl)acrylamide and (E)-N-(2-(benzo[d]thiazol-6-yl)ethyl)-3-(4-(trifluoromethyl)phenyl)acrylamide displayed 29.3 mg/L and 10.7 mg/L EC₅₀ value against A. alternala, respectively, which possessed equivalent fungicidal activities level to hymexazol.     

Two-phase species–time relationships in North American land birds

The species–time relationship (STR) is a macroecological pattern describing the increase in the observed species richness with the length of time censused. Understanding STRs is important for understanding the ecological processes underlying temporal turnover and species richness. However, accurate characterization of the STR has been hampered by the influence of sampling. I analysed STRs for 521 breeding bird survey communities. I used a model of sampling effects to demonstrate that the increase in richness was not due exclusively to sampling. I estimated the time scale at which ecological processes became dominant over sampling effects using a two‐phase model combining a sampling phase and either a power function or logarithmic ecological phase. These two‐phase models performed significantly better than sampling alone and better than simple power and logarithmic functions. Most community dynamics were dominated by ecological processes over scales <5 years. This technique provides an example of a rigorous, quantitative approach to separating sampling from ecological processes.     

Local-regional relationships and the geographical distribution of species

Aim Local‐regional (LR) species diversity plots were conceived to assess the contribution of regional and local processes in shaping the patterns of biological diversity, but have been used also to explore the scaling of diversity in terms of its alpha, beta, and gamma components. Here we explore the idea that patterns in the geographical ranges of species over a continent can determine the shape of small region to large region (SRLR) plots, which are equivalent to LR plots when comparing the diversity of sites at two regional scales. Location To test that idea, we analysed the diversity patterns at two regional scales for the mammals of North America, defined as the mainland from Alaska and Canada to Panama. Method We developed a theoretical model relating average range size of species over a large‐scale region with its average regional point species diversity (RPD). Then, we generated a null model of expected SRLR plots based on theoretical predictions. Species diversities at two scales were modelled using linear and saturation functions for Type I and Type II SRLR relationships, respectively. We applied the models to the case of North American mammals by examining the regional diversity and the RPD for 21 large‐scale quadrats (with area equal to 160,000 km²), arranged along a latitudinal gradient. Results Our model showed that continental and large‐scale regional patterns of distribution of species can generate both types of SRLR relationship, and that these patterns can be reflected in LR plots without invoking any kind of local processes. We found that North American nonvolant mammals follow a Type I SRLR relationship, whereas bats follow a Type II pattern. This difference was linked to patterns in which species of the two mammalian groups distribute in geographical space. Conclusion Traditional LR plots and the new SRLR plots are useful tools in exploring the scaling of species diversity and in showing the relationship between distribution and diversity. Their usefulness in comparing the relative role of local and regional processes is, however, very limited.