检索结果-南通市图书馆

Different patterns of molecular,carbon and hydrogen isotope compositions of n-alkanes between heterotrophic plant and its hosts

在线全文

学校读者我要写书评

暂无评论

Frontiers of Earth Science 2020年第4期14卷 783-788页

作者： Xin Yang xianyu huang State Key Laboratory of Biogeology and Environmental Geology China University of GeosciencesWuhan430078China Hubei Key Laboratory of Critical Zone Evolution School of Geography and Information EngineeringChina University of GeosciencesWuhan430078China

This study investigates the molecular,carbon,and hydrogen isotope compositions of n-alkanes in eight pairs of a holoparasitic plant(Cuscuta chinensis)and its *** is unexpected that *** has a higher concentration of n-alkanes than its hosts in seven of the eight pairs,and it is preferentially dominated by n-C_(29) alkane(representing>75%of the total n-alkanes).In addition,theδ^(13)C values of C_(29) alkane in *** are less negative(avg.1.8‰)than those in the hosts,while theδ^(2)H values of C_(29) alkane are more negative in ***(the difference averages 48‰).We propose that the ^(2)H-depletion of n-alkanes in the stem parasite *** may result from the utilization of stem water with less influence from evapotranspiration or the use of newly synthesized carbohydrates which is ^(2)H-depleted relative to stored *** results highlight the importance of plant nutrient status on the molecular and isotopic compositions of leaf waxes,which shed light on the(paleo)ecological potential of leaf waxδ^(2)H values.

关键词： heterotrophic plant Cuscuta n-alkane carbon isotope hydrogen isotope

神农架大九湖泥炭孔隙水中微生物的碳代谢特征

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

地球科学 2024年第9期49卷 3241-3251页

作者：田文王红梅向兴王锐诚黄咸雨安徽科技学院资源与环境学院安徽滁州233100 中国地质大学流域关键带演化湖北省重点实验室湖北武汉430078 中国地质大学生物地质与环境地质国家重点实验室湖北武汉430078 上饶师范学院生命科学学院江西上饶334001

为研究水位波动下泥炭地微生物碳代谢特征,利用Biolog-Eco微平板技术对神农架大九湖不同水位下泥炭孔隙水中微生物的碳代谢图谱进行测定.结果表明,不同水位下微生物的碳代谢活性和多样性差异显著,均表现为中水位>低水位>高水位.酯类(丙... 详细信息

为研究水位波动下泥炭地微生物碳代谢特征,利用Biolog-Eco微平板技术对神农架大九湖不同水位下泥炭孔隙水中微生物的碳代谢图谱进行测定.结果表明,不同水位下微生物的碳代谢活性和多样性差异显著,均表现为中水位>低水位>高水位.酯类(丙酮酸甲酯、吐温40、吐温80、D-半乳糖酸γ内酯),氨基酸(L-精氨酸、L-天冬酰胺酸、L-苯基丙氨酸、L-丝氨酸和甘氨酰-L-谷氨酸),胺类(苯乙基胺、腐胺和N-乙酰基-D-葡萄胺)是引起微生物碳代谢差异的主要贡献者.冗余度分析显示,电导率(F=3.2,P=0.018)和氧化还原电位(F=2.6,P=0.044)显著影响微生物的碳代谢,其变化与水位波动密切相关.水位波动通过改变泥炭孔隙水中微生物的碳代谢功能进而影响泥炭地碳循环.

关键词：泥炭地孔隙水水位 Biolog⁃Eco微平板碳代谢碳循环环境微生物学.

在线全文

学校读者我要写书评

暂无评论

东北长白山泥炭地硅藻-水位埋深转换函数

地理科学 2024年第8期44卷 1459-1469页

作者：徐双余卜兆君黄咸雨彭佳李俊璐陈旭中国地质大学(武汉)地理与信息工程学院区域生态过程与环境演变湖北省重点实验室东北师范大学地理科学学院/长白山地理过程与生态安全教育部重点实验室

本研究基于2016、2019和2021年夏季在东北长白山地区7处泥炭地采集的160个表层样品和环境因子数据，结合表层样品硅藻分析，构建了硅藻属种与环境因子数据库，该数据库包括64个硅藻属种和11个环境变量。优势硅藻属种组合沿水位埋深梯度(... 详细信息

本研究基于2016、2019和2021年夏季在东北长白山地区7处泥炭地采集的160个表层样品和环境因子数据，结合表层样品硅藻分析，构建了硅藻属种与环境因子数据库，该数据库包括64个硅藻属种和11个环境变量。优势硅藻属种组合沿水位埋深梯度(0～66 cm)呈现明显分异，偏典范对应分析结果表明，水位埋深单独解释了硅藻组合数据总方差的8.4%，远大于其他环境因子的单独解释份额。基于此，选取加权平均模型和最大似然估计模型构建硅藻-水位转换函数。不同模型分析结果显示，典型回归耐受值降权加权平均模型构建的硅藻-水位转换函数表现最佳，剔除残差大于20%水位梯度(13.2 cm)的样品后进行留一法交叉检验，该模型的推导值与实测值相关系数最大和推导误差最小。本文构建的硅藻-水位转换函数为定量反演长白山地区泥炭地过去水位变化提供了新的有效方法。

关键词：硅藻指标典范对应分析加权平均模型水位埋深定量重建

SIRT6在肝纤维化形成进程中的作用及其机制

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

中国病理生理杂志 2024年第9期40卷 1652-1659页

作者：林夏萍黄仙玉孙健李映莹徐云燕黄波杨媛吴芹遵义医科大学基础药理教育部重点实验室暨特色民族药教育部国际合作联合实验室贵州遵义563006 遵义医科大学附属医院消化内科贵州遵义563003

目的:探讨沉默信息调节因子6(silent information regulator 6,SIRT6)对四氯化碳(carbon tetrachloride,CCl_(4))诱导的小鼠肝纤维化作用和机制,以及肝星状细胞在SIRT6沉默后其下游通路的表达变化。方法:将30只雄性C57BL/6J小鼠随机分... 详细信息

目的:探讨沉默信息调节因子6(silent information regulator 6,SIRT6)对四氯化碳(carbon tetrachloride,CCl_(4))诱导的小鼠肝纤维化作用和机制,以及肝星状细胞在SIRT6沉默后其下游通路的表达变化。方法:将30只雄性C57BL/6J小鼠随机分为正常对照组(n=6)和模型组(造模2、4、8、12周,n=24),采用腹腔注射CCl_(4)制备肝纤维化小鼠模型,每周2次,持续12周。检测各组小鼠血清丙氨酸氨基转移酶(alanine aminotransferase,ALT)、天门冬氨酸氨基转移酶(aspartate aminotransferase,AST)含量评估肝损伤;HE、Masson染色观察小鼠肝脏病理学改变;免疫组织化学染色检测小鼠肝脏α-平滑肌肌动蛋白(α-smooth muscle actin,α-SMA)的表达;Western blot检测肝脏α-SMA、SIRT6、第9位赖氨酸乙酰化的组蛋白H3(acetyl histone H3 at Lys9,H3K9ac)、第56位赖氨酸乙酰化的组蛋白H3(acetyl histone H3 at Lys56,H3K56ac)、白细胞介素1β(interleukin-1β,IL-1β)和IL-18蛋白的表达。将大鼠肝星状细胞(hepatic stellate cells-T6,HSC-T6)进行SIRT6基因沉默,分为NC siRNA组和SIRT6 siRNA组。Western blot检测SIRT6、H3K9ac和H3K56ac蛋白的表达。结果:与正常对照组比较,模型组小鼠血清中ALT和AST含量均显著升高(P<0.05);HE染色和Masson结果显示,模型组肝脏病理变化逐渐加重,胶原纤维沉积逐渐增多;免疫组织化学染色与Western blot均显示,在8和12周模型组中肝脏α-SMA表达显著增加(P<0.05);Western blot检测结果显示,CCl_(4)造模后各组小鼠肝脏中SIRT6蛋白表达均低于正常对照组(P<0.05),并随肝纤维化的加重逐渐降低;同时模型组小鼠肝脏H3K9ac、H3K56ac、IL-1β和IL-18表达水平在8、12周时明显升高(P<0.05);SIRT6沉默后,与NC siRNA组比较,SIRT6 siRNA组中的H3K9ac和H3K56ac显著增加(P<0.05)。结论:SIRT6缺乏通过H3K9ac和H3K56ac的异常增多使得IL-1β和IL-18的表达升高,加剧炎症反应而促进肝纤维化进程,提示SIRT6的表达异常参与了肝纤维化进程的发展。

关键词：肝纤维化四氯化碳肝星状细胞沉默信息调节因子6 炎症因子

Long chain n-alkanes and their carbon isotopes in lichen species from western Hubei Province： implication for geological records

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

Frontiers of Earth Science 2012年第1期6卷 95-100页

作者： xianyu huang Jiantao XUE Shouyu GUO State Key Laboratory of Geological Processes and Mineral Resources China University of GeosciencesWuhan 430074China Key Laboratory of Systematic Mycology and Lichenology Institute of MicrobiologyChinese Academy of SciencesBeijing 100101China

Five coticolous lichen samples were collected from western Hubei Province of China to analyze the long chain n-alkanes and their carbon isotope compositions. The n-alkanes range in carbon number from C17 to C33 with strong odd-over-even predominance between C21 and C33. Lichens are dominated by n-C29 in the samples of Dajiuhu, Shennongjia Mountain, but by both n-C23 and n- C29 at Qizimei Mountain. This difference may result from the different environmental conditions in these two sites. The δ13C values of long chain n-alkanes in lichen samples show the signature of C3 plants. Based on compound- specific carbon isotopic values and previous results, we state that alkane homologs 〉 C23 mainly originate from the symbiotic fungi, while symbiotic algae only contribute trace amount of long chain alkanes. Of great interesting is the occurrence of long chain 3-methylalkanes in the Qizimei samples. These anteiso compounds range from C24 to C32, displaying obvious even-over-odd predomi- nance. This study reveals that the association of long chain 3-methylalkanes with n-C23 alkane might be used as proxies to reconstruct the paleoecological implications of lichens in Earth history.

关键词： lichen alkarle 3-methylalkanes n-C23 alkane,compound specific carbon isotope

Phytolith records of the climate change since the past 15000 years in the middle reach of the Yangtze River in China

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Earth Science 2012年第1期6卷 10-17页

作者： Yansheng GU Hanlin WANG xianyu huang Hongxia PENG Junhua huang State Key Laboratory of Geobiology and Environmental Geology(BGEG) China University of GeosciencesWuhan 430074China Hubei Key Laboratory of Wetland Evolution&Eco-Restoration(WEER) China University of GeosciencesWuhan 430074China State Key Laboratory of Geological Processes and Mineral Resources China University of GeosciencesWuhan 430074China

Based on 14C dating and core sediments survey, phytolith records are employed to reconstruct paleovegetation and paleoclimate in the Jianghan Plain in the middle reach of the Yangtze River. Phytoliths identified are assigned into 21 well-described morphotypes and divided into four groups （Poaceae, fern, coniferous and broad-leaved）. The phytolith assemblages together with warmth index （Iw） are divided into 18 ecological zones, which reflect a complete vegetation history related to climate change in the middle reach of the Yangtze River during the past 15000 years. On the basis of the correlation ofphytolith records with the paleoclimatic indicators from stalagmite, peatland, North Atlantic deep-sea sediments, Loess Plateau of Central China, and Arabic Sea sediments, eight climatic phases are identified included Last Glacial Maximum （LGM）（20- 14.8 cal kaBP）, Last Deglaciation （LDG）（14.8-11.9 cal kaBP）, low-temperature phase in the Early Holocene （11.9-8 cal kaBP）, Holocene Opti- mum （8-4.9cal kaBP）, Holocene Katathermal （4.9- 1.1 cal kaBP）, Medieval Warmth Period （MWP）（1.1- 0.7 cal kaBP）, Little Ice Age （LIA）（0.7-0.15 cal kaBP）, and Modem Warming （0.15 cal kaBP-present）. Climatic events such as Bolling-Allerod warm intervals, Older Dryas, Inter-Allerod Cold Period, and Younger Dryas, and eight Holocene Bond events （B1-8） have been identified since the LDG. Our results demonstrate that the evolution of the climate in the research area has a strong link with the Indian Summer Monsoon （SW Monsoon）, Asian Summer Monsoon （SE Monsoon）, and Holocene events in North Atlantic simultaneously, which might indicate that solar variability affects the Earth surface climate system at the centennial and millennial scales.

关键词： core sediments middle reach of the YangtzeRiver 15000 years phytolith assemblages paleovegetation,paleoclimate

Optimization of acid digestion conditions on the extraction of fatty acids from stalagmites

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Earth Science 2012年第1期6卷 109-114页

作者： Canfa WANG Hongbin ZHANG xianyu huang Junhua huang Shucheng XIE State Key Laboratory of Biogeology and Environmental Geology China University of GeosciencesWuhan 430074China State Key Laboratory of Geological Processes and Mineral Resources China University of GeosciencesWuhan 430074China

Lipids in stalagmites have been shown the potential for the paleoclimate reconstruction. However, the low lipid content leads to the difficulty in gaining high resolution lipid record in stalagmites because large mass of samples are required. Previous studies have validated that the acid digestion can improve the yield of lipids, especially fatty acids （FAs） and 3-hydroxy fatty acids （3- OH-FAs）. In order to obtain more content of FAs and 3- OH-FAs with limited stalagmite sample weight, we investigate here how the acid digestion conditions （HC1 concentration, heating temperature and time duration） could affect the yields of FAs and 3-OH-FAs. Under different concentration of HC1, from 2.0 to 6.0 mol/L, the FAs keep the same step in content variation with 3-OH- FAs, and the highest yields of both two appeared under the 3 mol/L HCl. The content of 3-OH-FAs increases posi- tively with the heating temperature from 80℃ to 150℃, while FAs showed the highest content at 130℃. Both of FAs and 3-OH-FAs firstly increased to a high content and then decreased as the heating time duration varies from 1.0 to 4.0 h, with the highest yields of both two being at 3.0 h. Consequently, we suggest the optimized acid digestion condition is under 3 mol/L HC1, heating at 130℃ for 3 h and 5 g of each stalagmite sample are sufficient for the lipid analysis.

关键词： stalagmite lipids acid digestion optimization

Habitat Influence on the Molecular, Carbon and Hydrogen Isotope Compositions of Leaf Wax n-Alkanes in a Subalpine Basin, Central China

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Earth Science 2020年第4期31卷 845-852页

作者： Chaoyang Yan Yiming Zhang Yanzhen Zhang Zhiqi Zhang xianyu huang State Key Laboratory of Biogeology and Environmental Geology China University of GeosciencesWuhan 430078China Hubei Key Laboratory of Critical Zone Evolution School of Geography and Information EngineeringChina University of GeosciencesWuhan 430078China

Epidermal leaf waxes of terrestrial higher plants have been widely utilized for the reconstructions of paleoenvironment and paleoclimate in peat deposits. In this study, specimens of four plant species growing in both peatland and non-peatland habitats were retrieved to compare their molecular, carbon(δ13 C) and hydrogen(δ2 H) isotopic compositions of leaf wax n-alkanes from a closed subalpine basin in Central China. Three of the four species show quite higher total concentrations of n-alkanes in the relatively dry non-peatland setting than in the peatland. In addition, the δ2 H values of long-chain n-alkanes are generally less depleted in the peatland and are comparable among different plant species, which is interpreted as the influence of inundation condition and the possible limited supply of photosynthetic products. This study reveals different patterns of plant wax molecular and isotopic compositions between peatland and the surrounding non-peatland conditions, and confirms the paleoenvironmental potential of leaf wax ratios on the peat sequences.

关键词： habitat n-alkane compound specific carbon isotope compound specific hydrogen isotope peat deposit

Microbial roles equivalent to geological agents of high temperature and pressure in deep Earth

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2016年第11期59卷 2098-2104页

作者： XIE ShuCheng LIU Deng QIU Xuan huang xianyu Thomas J.ALGEO State Key Laboratory of Biogeology and Environmental Geology China University of Geosciences Laboratory of Critical Zone Evolution School of Earth Sciences China University of Geosciences State Key Laboratory of Geological Processes and Mineral Resources China University of Geosciences Department of Geology University of Cincinnati

Microbes not only show sensitive responses to environmental changes but also play important roles in geochemical and geophysical systems. It is well known that microbes have caused major changes in surface environments and biogeochemical cycles through Earth history. Microbial processes can also induce the synthesis of certain minerals under Earth-surface conditions that previously were believed to form only under high temperatures and pressures in the deep Earth. For example, microbes can promote the conversion of smectite to illite, synthesis of authigenic plagioclase, precipitation of dolomite, and biotransformation of geolipids. These effects of microbes are due to their large surface/volume ratios, enzyme production, and abundant functional groups. Microbial catalyzation of chemical reactions proceeds through reaction-specific enzymes, a decrease in Gibbs' s free energy, and/or break through the dynamics reaction thresholds via their metabolisms and physiology. Microbes can lower the surface free energy of mineral nuclei via biophysical adsorption due to their large surface/volume ratios and abundant functional groups. The mineral precipitation and transformation processes induced by microbes are functionally equivalent to geological processes operating at high temperatures and pressures in the deep Earth, suggesting that microbial processes can serve as analogs to deep abiotic processes that are difficult to observe.

关键词： Geobiology Microbial functional groups Illitization Plagioclase Dolomite Geolipids