广东鉴江水系底栖硅藻多样性与时空分布特征

为了解广东省鉴江水系底栖硅藻多样性和时空分布特征,对全流域进行了底栖硅藻采样调查。结果表明,从19个采样点4次采样中共检出底栖硅藻10科52属242种,其中舟形藻属(Navicula)、菱形藻属(Nitzschia)和异极藻属(Gomphonema)是优势类群,出现频次和相对丰度较高。硅藻多样性指数(丰富度、真香农多样性指数和真辛普森多样性指数)随河流等级呈现一定的空间分布特征,但它们季节变化不明显。底栖硅藻群落相异性在上游和下游河段较高,从一级到三级河流递减,四级河流又增加。底栖硅藻群落结构空间变化明显,季节变化显著。群落丰富度的稀疏曲线表明,热带河流底栖硅藻群落以400个体计数,不能完整反映底栖硅藻多样性。这些为鉴江水系河流健康监测和水生态保护奠定了基础。     

云南高原湖泊沿岸带底栖藻类群落的分布

对云南6个高原湖泊沿岸带底栖藻类的群落结构、现存量等进行了调查,研究期间发现底栖藻类群落主要由绿藻门的刚毛藻(Cladophora spp.)和硅藻门的一些附植种类组成,除硅藻群落在泸沽湖占优势外,其它湖泊中绿藻群落的相对比率高于硅藻.底栖藻类现存量(chl a)以星云湖最高(24 μg·cm-2);底栖硅藻密度以泸沽湖的鸟岛最高,为9.3×106 cells·cm-2.分析不同湖泊底栖硅藻的群落结构发现:底栖硅藻Epithemia sorex和Cocconeis klamathensis分别是泸沽湖和抚仙湖的绝对优势种,Amphora pediculus是阳宗海和滇池金宝的绝对优势种,洱海、星云湖和滇池又一村的优势种类较多,其中相对丰富度较高的主要是一些附植性种类.结果表明沿岸带的光照、营养水平和基质类型可能是影响底栖藻类群落分布的主要环境因子.     

雅砻江（锦屏段）及其主要支流底栖藻类群落与环境因子的关系

分别于2004年5月和11月对雅砻江(锦屏段)及其主要支流22个采样点的底栖藻类进行研究.共采获底栖藻类150种,分属3门(硅藻、绿藻和蓝藻),37属.其中硅藻门占绝对优势(96.5%),线性曲壳藻(Achnanthes linearis)和Achnanthes deflexa为绝对优势种,其相对丰富度分别为35.3%和11.0%.细端菱形藻(Nitzschia dissipata)和小型异极藻(Gomphonema parvulum)是雅砻江(锦屏段)干流的优势种,而线性曲壳藻、扁圆卵形藻(Cocconeis placentula)和Achnanthes deflexa是其他支流的优势种.基于底栖藻类的物种组成和相对丰度,对两次的采样点进行去势对应分析(DCA),结果发现:两次采样雅砻江(锦屏段)干流样点与其他支流样点在DCA第一轴上得到了很好的分化,表明研究区域底栖藻类群落存在明显的空间差异,这主要是由干流的特殊生境所致.典范对应分析(CCA)结果显示不同季节影响底栖藻类群落结构的环境因子有所差异.总磷(TP)是5月份影响底栖藻类空间分布的最主要因素;11月份影响底栖藻类空间分布的最主要环境因子为氨氮(NH4-N)和海拔(Elevation).     

广西北海西村港互花米草对红树林湿地大型底栖动物群落的影响

为了解互花米草(Spartina alterniflora)入侵红树林的生态影响, 作者对位于北海市西村港的红树林湿地以及周边互花米草盐沼的大型底栖动物群落多样性和群落结构进行了研究。2012年10月至2013年9月连续4次取样, 按照取样时间研究大型底栖动物的种类、物种组成、生物量和生物多样性等群落特征的差异, 探讨互花米草入侵红树林湿地对大型底栖动物的影响。本研究共采集底栖动物16种, 隶属于5门7纲15科, 其中互花米草群落10种, 红树林湿地12种。研究发现互花米草入侵后中国绿螂(Glauconome chinensis)个体数量剧增, 导致不同采样时间互花米草盐沼的大型底栖动物生物量均显著高于红树林湿地; 除个别月份外, 红树林湿地大型底栖动物的Margalef丰富度指数、Shannon-Wiener多样性指数、Simpson多样性指数和Pielou均匀度指数均显著高于互花米草群落。基于生境-采样时间的双因素方差分析结果表明, Shannon-Wiener多样性指数和Simpson指数在两种生境间差异显著; 两种生境的Margalef丰富度和Pielou均匀度指数在不同采样时间差异显著; 大型底栖动物生物量和物种数量在两种生境间和不同采样时间差异均显著。基于多元回归分析的研究结果表明, 互花米草密度是影响大型底栖动物生物量的关键因子, 而互花米草株高可以解释物种个体数量、Shannon-Wiener多样性指数和Simpson指数在两种生境的变化。对不同采样时间大型底栖动物群落结构的非度量多维度(non-metric multidimensional scaling, NMDS)分析结果表明, 红树林与互花米草群落的大型底栖动物群落相似性很低。总而言之, 在西村港地区, 互花米草入侵虽然增加了大型底栖动物的生物量, 但由于优势物种的凸显, 显著降低了大型底栖动物群落的多样性, 且种类组成与群落结构与红树林群落相比已有差异。由此可见, 互花米草入侵红树林对当地的大型底栖动物群落多样性造成影响。     

典型红树林生态系统藻类多样性及其在生态过程中的作用

藻类是红树林生态系统重要的生物类群, 根据生态习性可分为浮游植物、底栖微藻和大型藻类三个生态类群, 它们在红树林生态系统生物多样性、初级生产、元素循环等方面起着重要作用。但在红树林生态系统中, 关注重点多集中在红树植物和动物, 对其中的藻类重视不够, 且多数研究集中在近20年以及亚洲的红树林区。事实上, 红树林生态系统藻类非常丰富, 其多样性研究有助于深入揭示红树林生态系统的结构与功能。本文介绍了红树林生态系统藻类的组成类群及其重要性, 重点对红树林区浮游植物、底栖硅藻和大型海藻的种类组成、地理分布及其与初级生产力、水质污染、元素循环、碳库形成等生态过程中的作用的研究动态和进展等进行了总结。根据已有研究, 红树林区浮游植物和底栖硅藻的种类数一般为几十到上百种, 其中硅藻在种类和数量上都占绝对优势, 它们是重要的初级生产者、饵料生物和水质污染指示生物; 红树林区底栖大型藻类主要由红藻、绿藻、褐藻、蓝藻组成, 绿藻的种类较多, 红藻在数量上占优势; 藻类是红树林湿地碳库的重要贡献者, 在红树林湿地生态系统碳汇和碳循环中起重要作用。红树林生态系统是个高度动态和异质的系统, 今后应加强红树林藻类多样性的长周期、大尺度变化及不同生境藻类的综合研究, 关注大陆径流和潮汐对藻类多样性和蓝碳的影响, 借助沉积物藻类记录, 探明红树林区藻类的长周期变化, 反演气候变化和人类活动对红树林生态系统的影响过程和机制。     

东湖沿岸带底栖藻类群落的时空变化

武汉东湖是一个浅水富营养湖泊,其沿岸带底栖藻类群落的季节分布特征明显,夏季的优势种群是一些体积很小的硅藻类曲壳藻(Achnanthes spp.),其他大部分季节是绿藻门的团集刚毛藻(Cladophora glomerata)和硅藻门的变异直链藻(Melosira varians)。不同样点间的底栖藻类现存量差异不显著,但优势种类不同,以团集刚毛藻为优势的绿藻在处于中富营养区域的磨山样点比例最高,以变异直链藻为优势种的硅藻在严重富营养化的水果湖样点中比例最高。底栖藻类月平均现存量(以叶绿素a计)的时间变化格局为夏季最低(41.5μg/cm2),逐渐增加到秋、冬季节的最高峰值(55.3μg/cm2)。造成东湖夏季底栖藻类现存量低的原因是雨季水体环境的不稳定性和水位升高造成的低光照。不同样点间的chlb、chlc及chlb/a、chlc/a值具有显著差异,分析这种差异显示:在东湖的富营养化条件下,过渡的富营养化能增加底栖藻类群落中硅藻的比例,却降低了绿藻的比例;不同环境条件下的底栖藻类群落结构具有特异性,分析底栖藻类群落结构可以用来评价水环境健康状况。东湖底栖藻类现存量的季节变化规律与浮游藻类不同,它和水温成显著的负相关,但温度和浮游藻类并不是影响东湖沿岸带底栖藻类生物量变化的直接因子。团集刚毛藻等底栖丝状藻类给各种底栖动物提供了食物和栖息环境,在东湖生态系统中具有重要的作用和功能。     

广东省增江菱形藻属群落分布的时空特征

底栖硅藻是河流生态监测常用的生物监测指标, 为了解底栖硅藻中的菱形藻属(Nitzschia)分布格局及其对环境的指示作用, 于2010 年5 月、9 月和2011 年1 月对广东省增江的21 个采样点进行底栖硅藻采样调查和监测, 分析了底栖硅藻中菱形藻属的分布特征及群落结构与环境因子的关系。三次采样中共检出菱形藻属26 种, 其多样性(丰富度和真辛普森多样性指数)随河流等级呈先升高后下降的空间分布特征。3 种优势种(克劳斯菱形藻、谷皮菱形藻和亚针尖菱形藻)相对丰度的时空分布存在差异: 如克劳斯菱形藻的相对丰度在下游较高, 而亚针尖菱形藻在中游较高; 2011 年1 月采样中的谷皮菱形藻相对丰度明显低于2010 年5 月和9 月。逐步回归表明, 环境因子对菱形藻属相对丰度变化的解释率较高, 三个次采样季节的解释率(Adjusted R2)在60%左右。2010 年9 月和2011 年1 月两次采样的冗余分析中, 环境因子均能显著解释菱形藻属群落的变异, 解释量分别为43.7%和37.9%。多元方差分析表明, 菱形藻属群落结构空间变化明显, 季节变化显著。     

南麂列岛砂质潮间带底栖硅藻多样性与群落结构的时空变化

为了解南麂列岛国家级海洋自然保护区砂质潮间带底栖硅藻多样性与群落结构的现状及近20多年来的变化,于2013年11月至2014年8月,对南麂列岛火焜岙砂质潮间带的底栖硅藻进行了4个季节的采样和研究,并与1981–1993年有关的历史资料进行了比较分析。本研究共鉴定底栖硅藻49属120种,海岸曲解藻(Fallacia litoricola)、史氏双壁藻(Diploneis smithii)、稀疏双壁藻(D.parca)等17种为目前的优势种。Shannon多样性指数在2.388–3.445之间,以春季最高,秋季最低;在空间分布上依次为:中潮区低潮区高潮区。相似性分析(analysis of similarities,ANOSIM)表明底栖硅藻群落在不同潮区间差异显著,而季节差异不显著。BIOENV分析显示盐度与底栖硅藻群落结构的相关性最高。本研究结果表明,南麂列岛砂质潮间带的底栖硅藻群落结构近几十年来已发生了明显变化。与1981–1993年南麂列岛的3次调查数据相比,目级阶元减少了2个,科级阶元增加了7个,而属级和种级阶元较过去的29属55种有了显著增加,这可能是分类研究强度增加所致。但分类学多样性降低,平均分类差异指数Δ+由过去的79.79降至71.41;且过去记录的大个体固着类群被现今的小个体固着类群和间隙运动类群(epipelon)所取代,这可能是火焜岙过去人类活动频繁、有机质过量排放的长期效应所致。     

增江底栖硅藻种类多样性及分布特征

2010年1月和5月对东江水系重要支流增江进行底栖硅藻的采样调查,分析了增江流域底栖硅藻的多样性和时空分布特征,并探讨了硅藻优势种与环境因子的关系.结果表明,两次采样共检出底栖硅藻42属178种(包括亚种和变种),与1月份相比,由于5月份降雨量较大,硅藻的数量有所下降,种类组成也有所改变.在两次采样中,藻类分布从下游到...     

互花米草入侵对红树林底栖甲壳动物和鱼类功能群及生态位的影响

为了解互花米草入侵对红树林湿地生态系统底栖甲壳动物和鱼类的影响,本研究利用地笼方式于2020年8月、2021年1月和4月对福建漳江口2个原生红树林样地(白骨壤和秋茄)、2个互花米草入侵样地以及1个光滩样地的底栖甲壳动物和鱼类进行采样调查。采用相对重要性指数、Shannon多样性指数、Pielou均匀度指数和Margalef丰富度指数分析底栖甲壳动物和鱼类的优势种及物种多样性,统计其功能群,并计算其生态位宽度和生态位重叠指数。结果表明: 3个季节共采集到底栖甲壳动物和鱼类种类37种,隶属于2门2纲8目17科,其中大多数为暖水性和广盐性物种,且以肉食性和杂食性功能群为主。双因素方差分析和非度量多维尺度分析结果表明,相比光滩,互花米草入侵后,底栖甲壳动物和鱼类的群落多样性指数变化不显著,但功能群发生了显著变化,浮游生物食性功能群以及肉食性和植食性功能群物种均有一定程度的增加。相比红树林样地,互花米草样地内底栖甲壳动物和鱼类物种丰富度更高。优势物种的时空生态位宽度变化范围在0～1.4186,其中棱鮻最高(1.4186),其次是中华乌塘鳢(1.0168)、刀额新对虾(0.9469)、脊尾白虾(0.8922)。     

Crystal structure, detonation performance, and thermal stability of a new polynitro cage compound: 2, 4, 6, 8, 10, 12, 13, 14, 15-nonanitro-2, 4, 6, 8, 10, 12, 13, 14, 15-nonaazaheptacyclo [5.5.1.13, 11. 15, 9] pentadecane

A new polynitro cage compound 2, 4, 6, 8, 10, 12, 13, 14, 15-nonanitro-2, 4, 6, 8, 10, 12, 13, 14, 15-nonaazaheptcyclo [5.5.1.1(3,11).1(5,9)] pentadecane (NNNAHP) was designed in the present work. Its molecular structure was optimized at the B3LYP/6-31 G(d,p) level of density functional theory (DFT) and crystal structure was predicted using the Compass and Dreiding force fields and refined by DFT GGA-RPBE method. The obtained crystal structure of NNNAHP belongs to the P-1 space group and the lattice parameters are a = 9.99 ?, b = 10.78 ?, c = 9.99 ?, α = 90.01°, β = 120.01°, γ = 90.00°, and Z = 2, respectively. Based on the optimized crystal structure, the band gap, density of state, thermodynamic properties, infrared spectrum, strain energy, detonation characteristics, and thermal stability were predicted. Calculation results show that NNNAHP has detonation properties close to those of CL-20 and is a high energy density compound with moderate stability.     

Distribution of N,P, K,Ca, Mg,S, Zn,Fe, Mn and Cu in groundnut

Summary Concentration of N, P, K, Ca, Mg and S in summer groundnut crop was higher than in kharif while Zn, Fe, Mn and Cu contents were higher in summer crop. Kernel's N, P and Zn; Leaflet's Ca and Mn; Stem's K and Fe; Root's S and Cu and Petiole's Mg contents were highest. Shell's N, P, K, Mg, S, Zn and Cu; Kernel's Ca, Fe and Mn contents were the least. N, P, K, S, Zn and Cu concentrations decreased linearly as the crop grew. Ca, Mg, Fe and Mn concentrations did not display any distinct pattern. Ca concentration was positively correlated with pod yield in both the seasons.     

Relations of the Al,B, Ba,Br, Ca,Cl, Cu,Fe, K,Li, Mg,Mn, Na,P, S,Si, Sr,and Zn mass fractions to morphometric parameters in pediatric and nonhyperplastic young adult prostate glands

The variation with age of the 18 trace element mass fractions and some histological characteristics of intact prostate glands of 50 subjects aged 0–30 years was investigated by instrumental neutron activation analysis, inductively coupled plasma atomic emission spectrometry, and a quantitative morphometric analysis. Mean values ± standard error of the mean (M ± SΕΜ) for the mass fractions (in milligrams per kilogram wet tissue) of these trace elements in pre-puberty were: Al 28.5 ± 9.0, B 0.40 ± 0.11, Ba 1.48 ± 0.44, Br 10.5 ± 1.5, Ca 241 ± 30, Cl 3,203 ± 278, Cu 3.51 ± 0.89, Fe 33.7 ± 4.1, K 2,364 ± 145, Li 0.020 ± 0.004, Mg 153 ± 23, Mn 0.46 ± 0.06, Na 2,286 ± 130, P 1,391 ± 100, S 1,698 ± 132, Si 62 ± 11, Sr 0.38 ± 0.08, and Zn 27.6 ± 2.3. During puberty and postpuberty, when there is a significant increase in circulating androgens, the mean values were: Al 7.2 ± 1.4, B 0.21 ± 0.05, Ba 0.25 ± 0.06, Br 5.8 ± 1.0, Ca 433 ± 81, Cl 2,314 ± 201, Cu 1.77 ± 0.13, Fe 20.9 ± 1.6, K 2,585 ± 118, Li 0.0088 ± 0.0014, Mg 232 ± 27, Mn 0.34 ± 0.04, Na 1,875 ± 107, P 1,403 ± 98, S 1,673 ± 73, Si 22.2 ± 3.1, Sr 0.22 ± 0.03, and Zn 93.3 ± 8.9. Mean values (M ± SΕΜ) of percent volumes (%) of the stroma, epithelium and lumen in the prostate before puberty were 73.4 ± 2.6, 20.4 ± 1.7, and 4.45 ± 0.94, respectively, versus 46.5 ± 2.5, 38.5 ± 1.9, and 14.9 ± 1.2 during puberty and postpuberty. This work’s results confirm that the Zn mass fraction in prostate tissue is an androgen-dependent parameter. For the first time it has been demonstrated that the glandular lumen is a main pool of Ca, Mg, and Zn accumulation and that the stroma is a main pool of Al, B, Ba, Br, Cl, Cu, Fe, Mn, Na, and Si accumulation in the normal human prostate, for the age range 0–30 years. It was concluded that the Ca, Mg, and Zn binds tightly within the prostatic fluid, because the volume of glandular lumen reflects the volume of prostatic fluid.     

Simultaneous measurement of the trace elements Al, As, B, Be, Cd, Co, Cu, Fe, Li, Mn, Mo, Ni, Rb, Se, Sr, and Zn in human serum and their reference ranges by ICP-MS

The goal of this article was to establish reference ranges of the concentration of trace elements in human serum and to compare these results with those reported by other authors. We describe the sample preparation and measurement conditions that allow the rapid, precise, and accurate determination of Al, As, B, Be, Cd, Co, Cu, Fe, Li, Mn, Mo, Ni, Rb, Se, Sr, and Zn in human serum samples (n=110) by inductively coupled plasma-mass spectrometry (ICP-MS). Accuracy and precision were determined by analyzing three reconstituted reference serum samples by comparison with other methods and by the standard addition procedure. The advantages of the ICP-MS method include short time of analysis of the elements mentioned, low detection limit, high precision, and high accuracy. Disadventages include a high risk of contamination due to the presence of some of the elements of interest in the environment, the relatively delicate sample handling, and the high cost of the equipment.     

Reference values for the concentrations of As,Cd, Co,Cr, Cu,Fe, I,Hg, Mn,Mo, Ni,Pb, Se,and Zn in selected human tissues and body fluids

This report attempts to formulate reference ranges of elemental concentrations for 15 trace elements in selected human tissues and body fluids. A set of samples consisting of whole blood, blood serum, urine, milk, liver, and hair were chosen and considered for 15 elements of biological significance: As, Cd, Co, Cr, Cu, F, Fe, I, Hg, Mn, Mo, Ni, Pb, Se, and Zn. The results represent wholly or partially data received from 40 countries of the global regions of Africa, Asia, Europe, North, South, and Central America, Australia, and New Zealand. This survey, even if qualitative, has been useful in demonstrating certain trends of trace-element scenarios around the world. It is of course recognized that both diet and environment exert a strong influence on the distribution pattern of several elements, such as As, Cd, Mn, Pb, Se, and Zn. A limited comparison of the available information on soil status of different countries reflected some interesting associations for elements, such as Mn and Zn. Importantly, this study revealed that only a few countries were in a position to identify a reasonable amount of data on samples requested for this project. Regretably, for a number of countries, any dependable data for even such essential elements as Cu, Fe, and Zn were not available. In view of the nutritional importance of many elements, the time is ripe for concerted efforts by intergovernmental agencies to initiate investigations or commission task forces/projects to generate reliable reference data for selected global regions, which sadly lack data of any kind at present.     

The Effect of Age and Gender on Al, B, Ba, Ca, Cu, Fe, K, Li, Mg, Mn, Na, P, S, Sr, V, and Zn Contents in Rib Bone of Healthy Humans

The effect of age and gender on major, minor, and trace element contents in the intact rib bone of 80 relatively healthy 15–55-year-old women and men was investigated. Contents or upper limit of contents of 16 chemical elements in the rib bone were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES). Mean values (M?±?SΕΜ) for the mass fraction of Ba, Ca, Cu, Fe, K, Li, Mg, Na, P, S, Sr, and Zn (milligram per kilogram of dry bone) were as follows: 2.54?±?0.16, 171,400?±?4,050, 1.35?±?0.22, 140?±?11, 1,874?±?71, 0.049?±?0.011, 2,139?±?38, 5,378?±?88, 75,140?±?1,660, 1,881?±?51, 291?±?20, and 92.8?±?1.5, respectively. The upper limits of contents of Al, B, Mn, and V were <7.20, <0.65, <0.36, and <0.03, respectively. Statistically significant tendency for the Ca, Mg, and P content to decrease with age was found in the human rib bone, regardless of gender. The mass fraction of Fe in the male rib bone increases with age. It was shown that higher Ca, Mg, Na, P, and Sr mass fractions as well as lower Fe content were typical of female ribs as compared to those in male ribs.     

Potential Compounds for Oral Cancer Treatment: Resveratrol,Nimbolide, Lovastatin,Bortezomib, Vorinostat,Berberine, Pterostilbene,Deguelin, Andrographolide,and Colchicine

Oral cancer is one of the main causes of cancer-related deaths in South-Asian countries. There are very limited treatment options available for oral cancer. Research endeavors focused on discovery and development of novel therapies for oral cancer, is necessary to control the ever rising oral cancer related mortalities. We mined the large pool of compounds from the publicly available compound databases, to identify potential therapeutic compounds for oral cancer. Over 84 million compounds were screened for the possible anti-cancer activity by custom build SVM classifier. The molecular targets of the predicted anti-cancer compounds were mined from reliable sources like experimental bioassays studies associated with the compound, and from protein-compound interaction databases. Therapeutic compounds from DrugBank, and a list of natural anti-cancer compounds derived from literature mining of published studies, were used for building partial least squares regression model. The regression model thus built, was used for the estimation of oral cancer specific weights based on the molecular targets. These weights were used to compute scores for screening the predicted anti-cancer compounds for their potential to treat oral cancer. The list of potential compounds was annotated with corresponding physicochemical properties, cancer specific bioactivity evidences, and literature evidences. In all, 288 compounds with the potential to treat oral cancer were identified in the current study. The majority of the compounds in this list are natural products, which are well-tolerated and have minimal side-effects compared to the synthetic counterparts. Some of the potential therapeutic compounds identified in the current study are resveratrol, nimbolide, lovastatin, bortezomib, vorinostat, berberine, pterostilbene, deguelin, andrographolide, and colchicine.