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Reproductive Biology of the Male Sheath-Tailed Bat,Taphozous longimanus(Emballonuridae) From India

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Biomedical and Environmental Sciences 1997年第1期10卷 14-26页

作者： UDAI PRATAP SINGH (centre of advanced study in Zoology, Banaras Hindu University, Varanasi, India) centre of advanced study in Zoology Banaras Hindu University Varanasi India.

The seasonal chronological events of the repreductive cycle in the male sheath-tailed bat T. longimanus and changes in structure and function of accessory sex organs were studied at Varanasi (latitude: 25° N, 83°E). The first peak of spermatogenesis was ob served in September with the appearance of spermatozoa. The spermatogenic arrest in win ter dormancy (December) was followed by a second peak of spermatogenesis in January.This perbo coincides with ovulation in females. The third peak of spermatogenesis started after regression in late April, and completely regressed tubules were found after May. The cycle of accessory sex gland complex generally paralleled the testicular cycle, reaching maxi mum hypertrophy from September to January and again in late April. Thereafter, the ac cesory sex glands involuated. Spermatozoa were present in the cauda epididymidis through out the year. The reproductive cycle in family Emballonuridae varies with changes in lati tude, and this was so even in members of the same species. The presence of spermatozoa in the cauda epididymidis throughout the year is an interesting feature in the reproductive cy cle. Temperature and photoperiod do not play a regulatory role in reproduction in T.longimanus

关键词： Reproductive Biology of the Male Sheath-Tailed Bat,Taphozous longimanus From India Emballonuridae

Metal Induced Inhibition of Photosynthesis,Photosynthetic Electron Transport Chain and ATP Content of Anabaena doliolum and Chlorella vulgaris:Interaction with Exogenous ATP

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Biomedical and Environmental Sciences 1992年第3期5卷 241-250页

作者： NIRUPA MAMALLICK L.C.RAI Laboratory of Algal Biology Centre of Advanced Study in Botany Banaras Hindu UniversityLaboratory of Algal Biology Centre of Advanced Study in Botany Banaras Hindu University Varanasi 221005 IndiaVaranasi 221005 India

This study demonstrates a concentration dependent inhibition of carbon fixation, O2 evolution, photosynthetic electron transport chain and ATP content of A. doliolum and C. vulgaris by Cu, Ni and Fe. Although the mode of inhibition of photosynthetic electron transport chain of both the algae was similar, PS II depicted greater sensitivity to the test metals used. The toxicity in both organisms was Cu > Ni > Fe. A. doliolum was, however, more sensitive to Cu and Ni, and C. vulgaris to Fe. Toxicity was generally dependent on metal uptake, which in turn was dependent on their concentrations in the external medium. A partial restoration of nutrient uptake, carbon fixation, and enzyme activities following supplementation of exogenous ATP suggests that ATP regulates toxicity through chelation.

关键词： Metal Induced Inhibition of Photosynthesis,Photosynthetic Electron Transport Chain and ATP Content of Anabaena doliolum and Chlorella vulgaris ATP

Impact of Spectral Quality on Toxicity of Iron in Anabaena Doliolum and Chlorella Vulgaris.

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Biomedical and Environmental Sciences 1992年第1期5卷 65-75页

作者： NIRUPAMA MALLICK L. C. RAI Laboratory of Algal Biology Centre of Advanced Study in Botany. Banaras Hindu UniversityLaboratory of Algal Biology Centre of Advanced Study in Botany. Banaras Hindu University Varanasi-221005 IndiaVaranasi-221005 India

Evidence is presented on the effects of low and high concentrations of iron on growth, nutrient uptake (NH4+and NO3-), photosynthesis (CO2-fixation and O2-evolution) and nitrate reductase (NR) activity of A. doliolum and C. vulgaris under monochromatic irradiation. Control cultures (not treated with FeCl3) showed maximum growth under fluorescent followed by red, yellow, blue and green lights (fluorescent > yellow > red > blue > green). The inhibition was of synergistic type under yellow and red lights at all the iron concentrations tested. However, under blue and green lights the interaction was less than additive type. All the processes studied responded in a similar manner to a particular color of light. Under fluorescent light at low Fe concentrations, stimulation of NR, 14CO2-fixation and O2-evolution was noticed in both the test organisms. However, even the lowest concentration of iron tested was inhibitory to these processes under yellow and red lights. Under blue light at 20 μg-ml-1 Fe, NR activity was inhibited by 98%. This study clearly demonstrates that metal toxicity to phytoplankton will be greatly affected by spectral quality, hence it will have great significance in limnological research.

关键词： Chlorella Anabaena photosynthesis yellow vulgaris lights uptake photosynthetic reductase irradiation

Quasi-in-situ Observation and SKPFM Studies on Phosphate Protective Film and Surface Micro-Galvanic Corrosion in Biological Mg-3Zn-xNd Alloys

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Acta Metallurgica Sinica(English Letters) 2024年第4期37卷 648-664页

作者： Zhaochen Yu Kaixuan Feng Shuyun Deng Yang Chen Hong Yan Honggun Song Chao Luo Zhi Hu School of advanced Manufacturing Nanchang UniversityNanchang330031China Institute for advanced study Nanchang UniversityNanchang330031China

The phosphate protective film and micro-galvanic corrosion of biological Mg-3Zn-xNd (x = 0, 0.6, 1.2) alloys were investigated by scanning and transmission electron microscopy, quasi-in-situ observation, scanning Kelvin probe force microscopy (SKPFM) and electrochemical tests. The results revealed the Mg-Zn-Nd phases formed in Mg-3Zn alloy contained with Nd. Adding Nd resulted in a significant decline in the cracks of the phosphate protective film and micro-galvanic corrosion of alloys, which were recorded by quasi-in-situ observation. In addition, the Volta potential difference of Mg-Zn-Nd/α-Mg (~ 188 mV) was lower than MgZn/α-Mg (~ 419 mV) and Zn-rich/α-Mg (~ 260 mV), and the corrosion rates of alloys markedly decreased after the addition of 0.6 wt% Nd. The improvement in corrosion resistance of Nd-containing alloys was mainly attributed to the following: (i) the addition of Nd reduced the Volta potential difference (second phases/α-Mg);(ii) the phosphate protective film containing Nd_(2)O_(3) deposited on the surface of the alloys, effectively preventing the penetration of harmful anions.

关键词： Magnesium alloys Quasi-in-situ observation Phosphate protective film Scanning Kelvin probe force microscopy(SKPFM) Micro-galvanic corrosion

Histopathological Changes in the Epidermis of the Air Breathing Catfish Heteropneustes fossilis Exposed to Sublethal Concentration of Mercuric Chloride

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Biomedical and Environmental Sciences 1993年第4期6卷 405-412页

作者： M.T.RAJAN T.K.BANERJEE Histochemistry Histochemistry and Histopathology Laboratory Centre of Advanced Study in Zoology Banaras Hindu UniversityVaranasi 221 005Indiaand Histopathology Laboratory Centre of Advanced Study in Zoology Banaras Hindu UniversityVaranasi 221 005India

Histopathological alterations induced by the sublethal concentration of (0.03 ppm) mercuric chloride solution on the epidermis of the fresh-water catfish Heteropneuates fossilis have been studied. It induces slow but significant histopathological changes in the various cellular components of the epidermis. It induces vacuolization, necrosis and pycnosis of the nuclei of the epithelial cells which subsequently shed. Loosening of epithelial cells of the outermost and middle layers following degeneration of the intercellular material and widened intercellular spaces is another important alteration. Prolonged mercury treatment also causes a gradual decrease in staining intensity for sulphated glycosaminoglycans in the outer border of the most superficial layer epithelial cells. The glandular elements (club cells and mucocytes) also get affected, showing cyclic degeneration followed by regeneration.

关键词： Histopathological Changes in the Epidermis of the Air Breathing Catfish Heteropneustes fossilis Exposed to Sublethal Concentration of Mercuric Chloride

In-situ AFM and quasi-in-situ studies for localized corrosion in Mg-9Al-1Fe-(Gd) alloys under 3.5 wt.% NaCl environment

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Journal of Magnesium and Alloys 2024年第3期12卷 1170-1185页

作者： Junping Shen Tao Lai Zheng Yin Yang Chen Kun Wang Hong Yan Honggun Song Ruiliang Liu Chao Luo Zhi Hu School of advanced Manufacturing Nanchang UniversityNanchang 330031China Institute for advanced study Nanchang UniversityNanchang 330031China Singapore centre for Environmental Life Sciences Engineering Nanyang Technological University60 Nanyang Drive 637751Singapore

Revealing the localized corrosion process of Mg alloy is considered as one of the most significant ways for improving its corrosion resistance.The reliable monitor should be high distinguishability and real-time in liquid environment.Herein,Mg-9Al-1Fe and Mg-9Al-1Fe-1Gd alloys were designed to highlight the impact of intermetallic on the corrosion behaviour.In-situ AFM with a special electrolyte circulation system and quasi-in-situ SEM observation were used to monitor the corrosion process of the designed alloys.SEM-EDS and TEM-SAED were applied to identify the intermetallic in the designed alloys,and their volta potentials were measured by SKPFM.According to the real-time and real-space in-situ AFM monitor,the corrosion process consisted of dissolution of anodicα-Mg phase,accumulation of corrosion products around cathodic phase and shedding of some fine cathodic phase.Then,the localized corrosion process of Mg alloy was revealed combined with the results of the monitor of corrosion process and Volta potential difference.

关键词： Magnesium Localized corrosion In-situ AFM SKPFM Corrosion behaviour.

Heavy Metal Toxicity in a N_2-Fixing Cyanobacterium, Anabaena doliolum: Regulation of Toxicity by Certain Environmental Factors

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Biomedical and Environmental Sciences 1990年第2期3卷 240-249页

作者： S.K.DUBEY L.C.RAI Laboratory of Algal Biology Centre of Advanced Study in BotanyBanaras Hindu University Varanasi-221005 India

The toxic effects of chromium and tin salts on growth, ^(14)C uptake, heterocyst differentiation, and nitrate reductase. nitrogenase, and glutamine synthetase activities of Anabaena doliolum and their regulation by pH. salinity, extracellular metabolites (spent), and organic acids have been studied. The toxicity of the test metals was lowered at alkaline pH and increased at acidic pH. NaCl at 20 mM was found to decrease metal toxicity. Extracellular metabolites (spent) in a 1:1 ratio(v/v) with fresh culture medium and organic acids were found to reduce metal toxicity. Among the various organic acids studied, humic acid was the most effective in regulating metal toxicity, apparently due to its multiple binding sites for metal cations. This study demonstrated that environmental factors.such as pH, salinity, extracellular metabolites, and organic acids, can mediate the toxicity of heavy metals to A. doliolum in a laboratory microcosm, (C)1990 Academic Press. Inc.

关键词： Anabaena doliolum

Protective Effects of Certain Natural and Synthetic Complexans on the Toxicity of Chromium and Tin to a N_2-Fixing Cyanobacterium, Anabaena doliolum

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Biomedical and Environmental Sciences 1989年第3期2卷 271-281页

作者： LC.RAI S.K.DUBEY Laboratory of Algal Biology Centre of Advanced Study in Botany Banaras Hindu University Varanasi-221005. India

The effects of chromium and tin on survival, growth, carbon fixation, nitrate reduction, ammonia assimilation, and nitrogenase activity of a N_2-fixing cyanobacterium, Anabaena doliolum, and their amelioration by synthetic and natural complexans, viz., EDTA, nitrilotriacetic acid (NTA), pyridine dicarboxylic acid (PDA), and citrate, have been studied. Chromium proved to be much more toxic than tin, as it inhibited growth yield (49%), carbon fixation (53%), and nitrate reductase (79%), glutamine synthetase (30%), and nitrogenase activities (77%) at its sublethal concentration, whereas tin induced less inhibition of growth yield (42%), carbon fixation (50%). and nitrate reductase (66%), glutamine synthetase (32.4%), and nitrogenase activities (70%). Despite its inhibitory effects at 10μml^(-1), EDTA supplementation in metal-spiked medium counteracted the toxicity of chromium and tin more significantly than NTA, PDA, and citrate. When supplemented with LD_(50) of Cr, EDTA protected growth, carbon fixation, NR, GS. and Noase, respectively, by 32.6, 50.0, 33.3. 17.7. and 65.4%. However, EDTA-induced restoration of the above parameters at a sublethal concentration of tin was only 30.2, 50.0,28.1, 27.7, and 61.5%, respectively. Although NTA and citrate at 10/μgml^(-1) each were stimulatory to various processes of test cyanobacterium, they were comparatively less effective than EDTA in the amelioration of metal toxicity. On the basis of these observations, a generalized hierarchical sequence of protective efficiency of synthetic and natural cornplexing ligands may be given as EDTA > NTA > citrate > PDA. It seems plausible that the toxicity of various heavy metals may be regulated by a large array of organic complexing agents of the aquatic environment because they possess various metal binding sites. (c) 1989 Academic Press,lnc.

关键词： NTA Anabaena doliolum Protective Effects of Certain Natural and Synthetic Complexans on the Toxicity of Chromium and Tin to a N2-Fixing Cyanobacterium PDA EDTA 络合试剂 Cr

Modulating the alloying mode in the doping-induced synthesis of Au-Pd nanowires

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Nano Research 2024年第4期17卷 3334-3343页

作者： Hui Jin Xiaoliang Wei Lecheng Zhao Jialong Yu Qiao Pan Shumin Li Qian Wang Zhaotong Yuan Dan Yang Donghui Zhao Hongyu Chen Yawen Wang Institute of advanced Synthesis School of Chemistry and Molecular EngineeringJiangsu National Synergistic Innovation Center for Advanced MaterialsNanjing Tech UniversityNanjing 211816China School of Science Westlake UniversityHangzhou 310064China Institute of Natural Sciences Westlake Institute for Advanced StudyHangzhou 310064China

Heterogeneous doping is one effective strategy for synthesizing metal alloy nanowires.Herein,the heterogeneous doping processes of Pd on the ultrathin Au nanowires were systematically modulated and investigated.Au-Pd alloy nanowires with various morphologies and lattice structures can be obtained by adjusting the morphology of the precursor Au nanowires and the kinetics of the heterogeneous doping processes.The effects of the rate of Pd reduction and the concentration of the ligand oleylamine(OAm)on the Pd deposition and alloying mode were articulated.Generally,as the Pd deposition rate decreases,the Pd deposition and alloying mode switches from the island-forming Stransky–Krastanov(SK)mode to the epitaxial Frank-van der Merwe(FM)mode,and eventually to an unconventional twisting alloying mode,where the interdiffusion of Pd and Au causes drastic rearrangement of the lattice structure and formation of helical structures.The kinetics-related variation of alloying mode could also be observed in the Au-Ag nanowires,demonstrating a general design principle for the synthesis of alloy nanostructures.In addition,the electrocatalytic performance of various Au-Pd nanowires was evaluated,and the alloy nanowire formed via the SK mode was found to be an excellent electrocatalyst for oxygen reduction and ethanol oxidation.

关键词： gold nanowires Au-Pd alloy oleylamine post-synthetic modification