检索结果-南通市图书馆

Eco-evolutionary evidence for the global diversity pattern of Cycas(Cycadaceae)

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Plant Biology 2024年第6期66卷 1170-1191页

作者： Jian Liu Anders JLindstrom Yiqing Gong shanshan dong Yusheng(Chris)Liu Shouzhou Zhang Xun Gong CAS Key Laboratory for Plant Diversity and Biogeography of East Asia Kunming Institute of BotanyChinese Academy of SciencesKunming 650201China Department of Economic Plants and Biotechnology Yunnan Key Laboratory for Wild Plant ResourcesKunming Institute of BotanyChinese Academy of SciencesKunming 650201China University of Chinese Academy of Sciences Beijing 100049China Global Biodiversity Conservancy 144/124 Moo3Soi Bua ThongBangsalaeSattahipChonburi 20250Thailand Key Laboratory of Southern Subtropical Plant Diversity Fairy Lake Botanical GardenShenzhen&Chinese Academy of SciencesShenzhen 518004China Department of Earth and Environmental Sciences Indiana University-IndianapolisIndianapolisIN 46202USA

The evolution of the latitudinal diversity gradient(LDG),characterized by a peak in diversity toward the tropics,has captured significant attention in evolutionary biology and ecology.However,the inverse LDG(i-LDG)mechanism,wherein species richness increases toward the poles,remains inadequately explored.Cycads are among one of the oldest lineages of extant seed plants and have undergone extensive diversification in the tropics.Intriguingly,the extant cycad abundance exhibits an i-LDG pattern,and the underlying causes for this phenomenon remain largely elusive.Here,using 1,843 nuclear genes from a nearly complete sampling,we conducted comprehensive phylogenomic analyses to establish a robust species-level phylogeny for Cycas,the largest genus within cycads.We then reconstructed the spatial-temporal dynamics and integrated global environmental data to evaluate the roles of species ages,diversification rates,contemporary environment,and conservatism to ancestral niches in shaping the i-LDG pattern.We found Cycas experienced decreased diversification rates,coupled with the cooling temperature since its origin in the Eocene from continental Asia.Different regions have distinctively contributed to the formation of i-LDG for Cycas,with the northern hemisphere acting as evolutionary museums and the southern hemisphere serving as cradles.Moreover,water-related climate variables,specifically precipitation seasonality and potential evapotranspiration,were identified as paramount factors constraining Cycas species richness in the rainforest biome near the equator.Notably,the adherence to ancestral monsoonal climates emerges as a critical factor in sustaining the diversity pattern.This study underscores the imperative of integrating both evolutionary and ecological approaches to comprehensively unravel the mechanisms underpinning global biodiversity patterns.

关键词： cycads latitudinal diversity gradient niche conservatism spatiotemporal diversification species richness

Experimental models for cancer brain metastasis

在线全文

学校读者我要写书评

暂无评论

Cancer Pathogenesis and Therapy 2024年第1期2卷 15-23页

作者： Zihao Liu shanshan dong Mengjie Liu Yuqiang Liu Zhiming Ye Jianhao Zeng Maojin Yao Guangzhou Institute of Respiratory Disease The First Affiliated Hospital of Guangzhou Medical UniversityChina State Key Laboratory of Respiratory DiseaseGuangzhouGuangdong 510182China Department of Medical Genetics and Cell Biology GMU-GIBH Joint School of Life SciencesGuangzhou Medical UniversityGuangzhouGuangdong 511436China Department of Microbiology Immunologyand Cancer BiologyUniversity of Virginia Health SystemCharlottesvilleVA 22908USA

Brain metastases are a leading cause of cancer-related mortality.However,progress in their treatment has been limited over the past decade,due to an incomplete understanding of the underlying biological mechanisms.Employing accurate in vitro and in vivo models to recapitulate the complexities of brain metastasis offers the most promising approach to unravel the intricate cellular and physiological processes involved.Here,we present a comprehensive review of the currently accessible models for studying brain metastasis.We introduce a diverse array of in vitro and in vivo models,including cultured cells using the Transwell system,organoids,microfluidic models,syngeneic models,xenograft models,and genetically engineered models.We have also provided a concise summary of the merits and limitations inherent to each model while identifying the optimal contexts for their effective utilization.This review serves as a comprehensive resource,aiding researchers in making well-informed decisions regarding model selection that align with specific research questions.

关键词： Brain metastases Blood-brain barrier Animal model In vitro model

New wheel-shaped Ln_(6) clusters for conversion of CO_(2) and magnetic properties

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

稀土学报:英文版 2023年第10期41卷 1574-1582,I0004页

作者： Wenmin Wang Na Qiao Xiaoyan Xin Chen Yang Ying Chen shanshan dong Chenxi Zhang College of Chemistry and Materials Taiyuan Normal UniversityJinzhong030619China College of Chemical Engineering and Materials Science Tianjin University of Science and TechnologyTianjin300457China

A series of novel hexanuclear lanthanide dusters,namely,[Ln_(6)(HL)_(6)(NO_(3))_(6)]·3CH_(3)CN(Ln=Gd(1),Tb(2),Dy(3)and Er(4))was assembled using a multidentate ligand H3L(trolamine).The clusters 1-4 show a wheel-shaped Ln_(6)topology with the approximate diameter and thickness of 1.5 and 0.7 nm,respectively.All of them show high thermal stability.In the aspect of the catalytic capacities for the cycloaddition reactions of CO_(2)and epoxide,the reaction conditions,the substrate scope,and possible catalytic mechanism were investigated.The highest yield for clusters 1-4 is up to 99%at 333 K for 12 h.In particular,cluster 1 can be reused at least three times with no obvious loss of catalytic performance and keep the integrity of the crystal structure.Magnetic investigations reveal that cluster 1 exhibits a relatively large magnetocaloric effect with-ΔS_(m)=41.43 J/(kg·K)(T=3.0 K,7.0 T);while cluster 3 displays slow magnetic relaxation behavior under zero dc field with U_(eff)=0.51 K andτ_(0)=2.54×10^(-5)s.

关键词： Wheel-shaped Ln_(6)clusters Conversion of CO_(2) Magnetocaloric effect Single-molecular magnet behavior Rare earths

羟基磷灰石复合腐植酸及其对Mn(Ⅱ)的去除

在线全文

学校读者我要写书评

暂无评论

无机盐工业 2024年第5期56卷 70-77页

作者：裴晓港张鹏董珊珊葛姗姗赵月龙太原理工大学环境科学与工程学院山西太原030000 山西师范大学现代文理学院转设筹备处山西临汾041075

以硝酸钙和磷酸氢铵为原料,采用化学沉淀法成功合成羟基磷灰石(HAP),并将其与腐植酸(HA)复合,制备出复合吸附剂HAP-HA。通过傅里叶变换红外光谱(FT-IR)、比表面积及孔径分析、差热-热重分析(TGDSC)及扫描电镜(SEM)等方法对样品进行表征... 详细信息

以硝酸钙和磷酸氢铵为原料,采用化学沉淀法成功合成羟基磷灰石(HAP),并将其与腐植酸(HA)复合,制备出复合吸附剂HAP-HA。通过傅里叶变换红外光谱(FT-IR)、比表面积及孔径分析、差热-热重分析(TGDSC)及扫描电镜(SEM)等方法对样品进行表征。结果表明:腐植酸成功负载到羟基磷灰石上;HAP-HA孔径主要分布在3~5 nm,比表面积较大,且具有较好的稳定性;HAP-HA表面粗糙不平、孔隙较多,这增大了比表面积,为重金属离子提供了大量的活性位点。以Mn(Ⅱ)为目标污染物,将Mn(Ⅱ)的去除率作为指标,通过吸附实验考察吸附剂HAP-HA对污染物的吸附性能。结果表明:在常温、pH为8.0、投加量为0.15 g、吸附时间为150 min的条件下,吸附剂HAP-HA对Mn(Ⅱ)的去除率最高,可稳定达到99.0%以上;该吸附过程符合Freundlich等温吸附模型。同时,对吸附后的吸附剂进行脱附及再生吸附实验,以NaOH溶液作为洗脱剂可取得较好的脱附效果,脱附效率可达78.1%,再生循环吸附6次后HAP-HA仍具有良好的吸附性能。

关键词：羟基磷灰石腐植酸吸附剂金属Mn(Ⅱ)

维普期刊数据库博看期刊

Metagenome analysis reveals potential microbial functions in topsoil of wheat-maize rotation system with five-year application of fertilizers

在线全文

学校读者我要写书评

暂无评论

International Journal of Agricultural and Biological Engineering 2019年第6期12卷 177-184页

作者： Yujun Shen Lixin Zhao Haibo Meng Hongsheng Cheng Jingtao Ding Jiarui Wang shanshan dong Xi Zhang Liqiu Song Shengwei Zheng Institute of Energy and Environmental Protection Chinese Academy of Agricultural EngineeringBeijing 100125China Key Laboratory of Technologies and Models for Cyclic Utilization from Agricultural Resources Ministry of AgricultureBeijing 100125China Key Laboratory of Energy Resource Utilization from Agriculture Residue Ministry of AgricultureBeijing 100125China

Fertilization mode affects soil quality and ecological health.The effects of four fertilization regimens on lignocellulose content,readily degradable carbohydrate decomposition,and potential microbial functions in the topsoil of a wheat-maize rotation system between 2012 and 2017 were investigated.The fertilization regimens of control(control NFNB),high chemical fertilizer(HCF),high biochar plus low chemical fertilizer(HBLCF),and biochar-based fertilizer(BBF)were compared on soil fundamental properties,microbial structure,and potential function in soil carbohydrate degradation based on metagenome analysis.The diversity of carbohydrate-active enzyme genes in the topsoil microbial consortia in the four trials was primarily distributed within the ten ecologically most dominant phyla.Application of BBF was associated with the lowest decline in total nitrogen and P2O5(2012-2017:6.5%and 28.1%,respectively)and the most effective carbohydrate decomposition(2015-2017:67.0%for cellulose and 59.9%for readily degradable carbohydrate).Carbohydrate transport and metabolism accounted for 6.0%of reads assigned functional classification under the BBF regimen.These findings reveal the ecologically functional diversity of topsoil microorganisms and suggest BBF application as a promising strategy for sustainable agriculture and beneficial to soil health.

关键词： biochar-based fertilizer carbohydrate decomposition genetic function microbial community topsoil

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

大电流密度下高性能析氢电催化剂研究进展

低碳化学与化工 2024年第5期49卷 96-104页

作者：张奇郑东前刘馨璐杨勇梁欣董珊珊中国石化销售股份有限公司应用技术研究院天津300384

H_(2)作为一种清洁能源,被认为是缓解能源危机和减少环境污染最有前景的替代能源之一。利用可再生能源电解水制氢是生产绿氢的重要方法,但是工业电解水制氢大多存在运行电流密度低、能耗高等难题。提高电流密度是提高产氢速率最直接的方... 详细信息

H_(2)作为一种清洁能源,被认为是缓解能源危机和减少环境污染最有前景的替代能源之一。利用可再生能源电解水制氢是生产绿氢的重要方法,但是工业电解水制氢大多存在运行电流密度低、能耗高等难题。提高电流密度是提高产氢速率最直接的方式,但是在未对电催化剂进行优化的情况下,提高电流密度会造成电耗的增加,因此亟需开发出在大电流密度下低过电位的高性能析氢反应(以下简称“HER”)电催化剂。首先介绍了在酸性和碱性介质中的HER反应机理:Volmer-Heyrovsky和Volmer-Tafel,提出了在大电流密度下高性能HER电催化剂需满足的要求;然后从单原子催化剂、合金催化剂和异质结构催化剂等角度出发,阐述了近年来国内外贵金属、非贵金属HER电催化剂的研究进展;最后对HER电催化剂未来发展所面临的挑战和机遇进行了分析。

关键词：电催化剂析氢反应大电流密度

Heavy metals and community structure of microorganism changes during livestock manure composting with inoculation of effective microorganisms

在线全文

学校读者我要写书评

暂无评论

International Journal of Agricultural and Biological Engineering 2020年第6期13卷 125-132页

作者： Haibin Zhou Yujun Shen Ran Li Haibo Meng Xi Zhang Jian Wang Hongsheng Cheng shanshan dong Liqiu Song Jingtao Ding Qiongyi Cheng Academy of Agricultural Planning&Engineering Ministry of Agriculture and Rural Affairs of the People's Republic of ChinaBeijing 100125China Key Laboratory of Technologies and Models for Cyclic Utilization from Agricultural Resources Ministry of Agriculture and Rural Affairs of the People's Republic of ChinaBeijing 100125China

Effective microorganisms(EM)is usually used in composting to improve the composting process.However,the effect of EM on heavy metals evolution was still unclear.This study was performed to illustrate the microbial community changes that occur during composting with the addition of EM and to determine the evolution of heavy metal speciation during this process.The requirement of harmlessness for pig manure was met after the addition of EM at a dosage of 0.5%,with a germination index of 96.42%.The bacterial and fungal diversity were both found to decrease during the composting process.Additionally,the bioavailability of Cu and Pb decreased significantly during composting.Significant correlations were observed between the microbial composition and the percentage of different heavy metals fractions;however,the mechanism responsible for this correlation requires further investigation.This study has the potential to contribute to control of heavy metal contamination during the process of recycling pig manure through the controlled addition of EM.

关键词： effective microorganisms heavy metal microbial communities pig manure composting

Investigation and analysis of the linkage mechanism and whole process cost of livestock manure organic fertilizer

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Agricultural and Biological Engineering 2020年第2期13卷 223-227页

作者： shanshan dong Bin Sui Yujun Shen Haibo Meng Lixin Zhao Jingtao Ding Haibin Zhou Xi Zhang Hongsheng Cheng Jian Wang Ran Li Liqiu Song Pengxiang Xu Ji Li Institute of Energy and Environmental Protection Academy of Agricultural Planning and EngineeringMinistry of Agriculture and Rural AffairsBeijing 100125China Key Laboratory of Technologies and Models for Cyclic Utilization from Agricultural Resources Ministry of Agriculture and Rural AffairsBeijing 100125China Key Laboratory of Energy Resource Utilization from Agriculture Waste Ministry of Agriculture and Rural AffairsBeijing 100125China College of Resources and Environmental Sciences China Agricultural UniversityBeijing 100193China

In recent years,the utilization of manure resources for livestock and poultry farming has attracted a widespread attention,and manure resources utilization models suitable for different regional characteristics have formed gradually.Among them,the production of organic fertilizer from animal manure is a vital utilization method.However,there are still some problems such as high production costs,difficult sales,and the unwillingness of farmers to use organic fertilizers which have affected the breeding cycle and the sustainability of manure treatment in livestock and poultry breeding.This article selected 371 organic fertilizer plants,related farms and farmers in China,focusing on the main links of the entire process of livestock manure-organic fertilizer-farm application,and studied the mode of animal manure collection by organic fertilizer plants.The costs of organic fertilizer production and farmland application were discussed.Moreover,suggestions were made for the promotion and implementation of large-scale organic fertilizers to make good utilization of manure resources in livestock and poultry farming.

关键词： livestock manure organic fertilizer compost production cost application cost

柠檬汁还原法制备AgNPs用于果蔬农药残留的SERS快速检测

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

智慧农业（中英文） 2024年第1期6卷 101-110页

作者：董闪闪张凤秋夏琦李佳林刘超柳少伟陈翔宇王儒敬黄青郑州大学物理学院、中原之光实验室河南郑州450001 中科合肥智慧农业协同创新研究院农业传感器与智能感知安徽省技术创新中心安徽合肥231131 中国科学院合肥物质科学研究院智能机械研究所安徽省智慧农业工程实验室安徽合肥230031 安徽农业大学材料与化学学院安徽合肥230036 安徽大学物质科学与信息技术研究院安徽合肥230601

[目的/意义]为满足目前市场上对农产品农药残留的快速灵敏检测需求,报道一种基于柠檬汁还原制备银纳米粒子(AgNPs)的方法。[方法]首先将新鲜柠檬汁经滤纸过滤,稀释成2%的柠檬汁水溶液,再配制一定浓度的AgNO3溶液、50 mM的NaOH溶液,放置... 详细信息

[目的/意义]为满足目前市场上对农产品农药残留的快速灵敏检测需求,报道一种基于柠檬汁还原制备银纳米粒子(AgNPs)的方法。[方法]首先将新鲜柠檬汁经滤纸过滤,稀释成2%的柠檬汁水溶液,再配制一定浓度的AgNO3溶液、50 mM的NaOH溶液,放置室温保存。然后在室温下,将10 mL的ddH2O、2mL的NaOH、2mL的2%柠檬汁和5 mL的AgNO3溶液混合,待溶液颜色变为澄清的黄色时,溶液离心即可获得AgNPs。[结果和讨论]该方法制备的AgNPs,其颗粒形貌大小基本均一,约为20 nm,具有很好的表面增强拉曼散射(Surface Enhancement of Raman Scattering,SERS)增强效应,即良好的SERS信号稳定性,较强的SERS增强性能。该胶体中AgNPs分散较均匀,并且具有较长时间储存的稳定性,因此可用于微量农残检测。柠檬汁中主要还原成分抗坏血酸、葡萄糖和果糖,其含量分别为395.76μg/mL、5.95 mg/mL和5.90 mg/mL。将柠檬汁还原法制备的AgNPs用于果蔬表面农残检测,对于百草枯、多菌灵的检出限分别最低至3.90 ng/kg及0.22μg/kg。[结论]这项工作为果蔬农残快检提供了一种绿色、便捷的SERS材料制备方法,为实现农产品农药残留的快速、灵敏检测提供一种新的途径。

关键词：表面增强拉曼散射/光谱(SERS) 银纳米粒子(AgNPs) 农药残留果蔬光谱检测