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Impact of redox-stratification on the diversity and distribution of bacterial communities in sandy reef sediments in a microcosm

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Chinese Journal of Oceanology and Limnology 2011年第6期29卷 1209-1223页

作者：高峥王鑫 Angelos k.HANNIDES Francis J.SANSONE 汪光义 State key Laboratory of Crop Biology College of Life Sciences Shandong Agricultural University Department of Oceanography University of Hawaii Shenzhen Engineering Laboratory for Algal Biofuel Technology Development and Application School of Environment and Energy Peking University Shenzhen Graduate School

Relationships between microbial communities and geochemical environments are important in marine microbial ecology and biogeochemistry. Although biogeochemical redox stratification has been well documented in marine sediments, its impact on microbial communities remains largely unknown. In this study, we applied denaturing gradient gel electrophoresis （DGGE） and clone library construction to investigate the diversity and stratification of bacterial communities in redox-stratified sandy reef sediments in a microcosm. A total of 88 Operational Taxonomic Units （OTU） were identified from 16S rRNA clone libraries constructed from sandy reef sediments in a laboratory microcosm. They were members of nine phyla and three candidate divisions, including Proteobacteria （Alphas, Beta-, Gamma-, Delta-, and Epsilonproteobacteria）, Aetinobacteria, Acidobacteria, Bacteroidetes, Chloroflexi, Cyanobacteria, Firmicutes, Verrucomicrobia, Spirochaetes, and the candidate divisions WS3, SO31 and AO19. The vast majority of these phylotypes are related to clone sequences from other marine sediments, but OTUs of Epsilonproteobacteria and WS3 are reported for the first time from permeable marine sediments. Several other OTUs are potential new bacterial phylotypes because of their low similarity with reference sequences. Results from the 16S rRNA, gene clone sequence analyses suggested that bacterial communities exhibit clear stratification across large redox gradients in these sediments, with the highest diversity found in the anoxic layer （15-25 mm） and the least diversity in the suboxic layer （3-5 mm）. Analysis of the nosZ, and amoA gene libraries also indicated the stratification of denitrifiers and nitrifiers, with their highest diversity being in the anoxic and oxic sediment layers, respectively. These results indicated that redox-stratification can affect the distribution of bacterial communities in sandy reef sediments.

关键词： bacterial diversity bacterial stratification biogeochemical gradients sandy reef sediments

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Species Diversity and Population Status of Threatened Plants in Different Landscape Elements of the Rohtang Pass,Western Himalaya

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Journal of Mountain Science 2008年第1期5卷 73-83页

作者： k.N.Singh Gopichand Amit kumar Brij Lal N.P.Todaria Biodiversity Division Institute of Himalayan Bioresource Technology (CSIR)PalampurHimachal Pradesh176 061India Forestry department HNB Garhwal UniversitySrinagarUttarakhandIndia

This paper highlights the quantitative estimates of plant species diversity and ecosystems of the Rohtang Pass,which is one of the most preferred visiting spots by tourists in Himachal Pradesh (H.P.),India. In spite of high pressure of anthropogenic activities,the Rohtang Pass still harbours a variety of flowering plants with economic value,including various medicinal herbs. In order to observe species diversity in different landscape elements (LSEs),ground surveys were conducted in nine unique LSEs within the elevation range between 3624 m and 4332 m. Plant community structure in each LSE was studied using stratified random sampling where a total 56 quadrats of 1 m2 in size for herbs and 7 quadrats of 25 m2 for shrubs were made. Of the total 50 plant species belonging to 15 families recorded in different random quadrats,24 species were found of medicinal value. Maximum species richness (18) and value of Shannon diversity (H'=2.2648) were observed on northeast-facing slope in Picrorhiza kurrooa dominated LSE in moist area,followed by Rheum emodi LSE (species richness = 17 and H' = 2.4141) distributed on south-facing slope. Maximum values of species richness and Shannon diversity in Rheum emodi LSE were observed between 8 ～ 12 and 1.4797 ～ 2.1911,respectively. Rhododendron anthopogon dominated LSE on northwest-facing slope was found least diverse in terms of species richness where the Simpson index of dominance (D) was 0.4205. The species were equal in abundance in P. kurrooa LSE on east-facing slope and Pleurospermum candollii LSE on north-facing slope,showing the maximum similarity in terms of species distribution between the two LSEs. Low turnover of species across common LSEs gives an idea regarding their limited distribution. Five species of threatened category according to the IUCN criteria were observed in seven LSEs. The largest population of threatened medicinal plants was recorded on northeast and northwest-facing slopes where population density of Bergenia

关键词： Species diversity threatened plant landscape Rohtang Pass western Himalaya

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Effect　of　Ballistic-Type　Hot　Atom　Adsorption　Mechanism　on　the　Phase　Diagram　of　Monomer　Dimer　CO-O2　Surface　Catalytic　Reaction：　A　Monte　Carlo　Simulation

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Chinese Physics Letters 2004年第6期21卷 1171-1174页

作者： M.khalid k.M.khan A.U.Qaisrani Q.N.Malik DepartmentofPhysics GomalUniversityDeraIsmailKhanPakistan NuclearPhysicsDivision PakistanInstituteofNuclearScienceandTechnology(PINSTECH)P.O.NiloreIslamabadPakistan

We investigate the effect of the ballistic mechanism on the phase diagram using a square surface. While using this mechanism whenever an O2 molecule hits a randomly vacant selected site, the molecule breaks up into atomic form and then executes a ballistic flight. The paths of the two oxygen atoms are taken exactly to be opposite to each other, ***-parallel, and the ranges of the atoms are taken to be equal, *** may fly up to 1 or 1.414 or 2 of the atomic spacing from the site of impact. Four cases have been studied on the basis of the range of hot atoms. The range of the hot oxygen atoms executing a ballistic flight might be up to the first nearest neighbourhood (1 atomic spacing from the site of impact), the second nearest neighbourhood (1.414 atomic spacing from the site of impact), the third nearest neighbourhood (2 atomic spacing from the site of impact), known as cases a, b, and c, respectively, while for case d the range of the oxygen atoms executing the ballistic flight might be up to 1 atomic spacing or 1.414 atomic spacing or 2 atomic spacing from the site of impact. The steady reactive window is observed and the continuous transition disappears. As soon as the CO partial pressure departs from zero, the production of CO2 is observed, which clearly verifies the experimental observation.

关键词： Oxygen

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A facile access for the synthesis of some C-2 substituted imidazopyrazines by utilizing the palladium catalyzed Suzuki cross-coupling reaction under microwave irradiation

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Chinese Chemical Letters 2016年第1期27卷 31-36页

作者： M.Nibin Joy Bhaskaran Savitha Ayyiliyath M.Sajith Yadav D.Bodke Talavara Venkatesh k.k.Abdul khader M.Syed Ali Padusha A.Muralidharan Department of P.G studies and Research in Industrial Chemistry Kuvempu University Post Graduate and Research Department of Chemistry Jamal Mohamed College Bharathidasan University Organic Chemistry Division School of Chemical Sciences Kasaragod Govt.College Kannur University

A rapid, efficient, and facile synthesis of an assortment of C-2 substituted imidazopyrazines has been achieved by utilizing the palladium catalyzed Suzuki cross-coupling of 2-bromo-1H-imidazo[4,5-b]pyrazine with various boronic acids under microwave irradiation. The utilization of（A-^（ta）phos）_2PdCl_2 as a catalyst in combination with Cs F as base and DME-H_2O（4：1） as the solvent system at 100℃ procured the diaryls in acceptable to excellent yields. Prominent features of this developed methodology include short reaction times, fewer side products, and exceptional tolerance to a wide variety of functional groups.

关键词： Imidazopyrazine Boronic acid Suzuki coupling Microwave

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等离子体浸没离子注入绝缘材料的研究

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核技术 2006年第5期29卷 335-338页

作者：田修波杨士勤 Ricky k Y Fu Paul k Chu 哈尔滨工业大学材料科学与工程学院哈尔滨150001 香港城市大学物理及材料科学系

等离子体浸没离子注入是一种新形式的离子注入技术,是利用负偏压工件周围形成的等离子体鞘层进行离子加速、进而获得离子注入。等离子体注入的前提条件是工件导电,因此对于绝缘材料的等离子体注入可能存在问题。本文从理论和实际处理的... 详细信息

等离子体浸没离子注入是一种新形式的离子注入技术,是利用负偏压工件周围形成的等离子体鞘层进行离子加速、进而获得离子注入。等离子体注入的前提条件是工件导电,因此对于绝缘材料的等离子体注入可能存在问题。本文从理论和实际处理的角度论证了绝缘材料等离子体注入的可能性、可操作性,并给出了一些实际例证。

关键词：等离子体离子注入绝缘材料鞘层表面充电

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kinetics of Al Evaporation from Liquid U-Al Alloys in Vacuum Induction Melting

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Journal of Materials Science & Technology 2015年第4期31卷 423-426页

作者： Y.J.Duan B.Chen Y.C.Ma k.Liu Materials for Special Environment Division Institute of Metal ResearchChinese Academy of Sciences

A research on kinetics of Al evaporation from liquid U—Al alloys was made in a vacuum induction melting（VIM） furnace at 1673—1843 *** evaporation rate of Al was found to be first order with respect to Al content in the *** overall mass transfer coefficient of Al was determined and it was found that the evaporation rate of Al increased with increasing *** apparent activation energy of Al evaporation at 1673-1843 k was 171.5 kJ *** value of mass transfer coefficient of Al in the liquid phase was estimated to be 3.77 × 10-6,7.41×10-6,and 9.40 × 10-6m s-1at 1673,1753,and 1843 k,***,rate determining steps were discussed and it was concluded that the evaporation rate of Al is mainly controlled by liquid phase mass transfer.

关键词： Al evaporation kinetics Liquid U-Al alloys Mass tr

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Characteristics of Ions Emitted from Laser-Induced Silver Plasma

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Plasma Science and Technology 2008年第4期10卷 450-454页

作者： M.S.RAFIQUE M.kHALEEQ-UR-RAHMAN Shakoor MUNAZZA k.A.BHATTI Department of Physics University of Engineering and TechnologyLahore-54890Pakistan

In this work, study of laser-induced ions is presented. The plasma was produced by focusing a Nd：YAG laser, with a wavelength of 1064 nm, a pulsed width of 9-14 ns, a power of 1.1 MW and energy of 10 mJ, on silver target in vacuum （10-3 Torr= 1.3332 Pa）. The characteristics of ion streams were investigated by CR-39 detectors located at angles of 0°, 30°, 60° and 90° with respect to normal of the target. The distance between the silver target and each detector was 11 cm. The energy of silver ions was found ranging from 1.5 eV to 1.06E4 eV. There was a high concentration of ions with low energy as compared to those with high energy, showing the energy distribution amongst the ions. The flux of ions was maximum in the axial direction which was decreasing with the angle increase with respect to normal of the target, and finally became minimum in the radial direction. Hence the silver ions have shown anisotropic behaviour.

关键词： Nd: YAG laser flux of ions anisotropic solid state nuclear track detector (SSNTD)

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Macrophage polarization in response to wear particles in vitro

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Cellular & Molecular Immunology 2013年第6期10卷 471-482页

作者： Joseph k Antonios Zhenyu Yao Chenguang Li Allison J Rao Stuart B Goodman Orthopaedic Research Laboratories Department of Orthopaedic Surgery Stanford University School of Medicine Stanford CA USA

Total joint replacement is a highly successful surgical procedure for treatment of patients with disabling arthritis and joint dysfunction. However, over time, with high levels of activity and usage of the joint, implant wear particles are generated from the articulating surfaces. These wear particles can lead to activation of an inflammatory reaction, and subsequent bone resorption around the implant （periprosthetic osteolysis）. Cells of the monocyte/macrophage lineage orchestrate this chronic inflammatory response, which is dominated by a pro-inflammatory （M 1） macrophage phenotype rather than an anti-inflammatory pro-tissue healing （M2） macrophage phenotype. While it has been shown that interleukin-4 （IL-4） selectively polarizes macrophages towards an M2 anti-inflammatory phenotype which promotes bone healing, rather than inflammation, little is known about the time course in which this occurs or conditions in which repolarization through I L-4 is most effective. The goal of this work was to study the time course of murine macrophage polarization and cytokine release in response to challenge with combinations of polymethyl methacrylate （PMMA） particles, lipopolysaccharide （LPS） and IL-4 in vitro. Treatment of particle-challenged monocyte/macrophages with IL-4 led to an initial suppression of pro-inflammatory cytokines and inducible nitric oxide synthase （iNOS） production and subsequent polarization into an M2 anti-inflammatory phenotype. This result was optimized when IL-4 was delivered before PMMA particle challenge, to an M 1 phenotype rather than to uncommitted （MO） macrophages. The effects of this polarization were sustained over a 5-day time course. Polarization of M1 macrophages into an M2 phenotype may be a strategy to mitigate wear particle associated periprosthetic osteolysis.

关键词： IL-4 macrophage polarization osteolysis PMMA particles total joint replacement

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Angular Differential Cross-Section for Ionization of Helium in C^6＋ Ion Collision

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Chinese Physics Letters 2004年第7期21卷 1258-1261页

作者： A.C.Gagyi-Palffy I.F.Barna L.Gulyas k.Tokesi DepartmentofTheoreticalPhysics UniversityofBucharestRomania Max-Planck-InstituteforPhysicsofComplexSystems NothnitzerStr.38O1187DresdenGermany InstituteofNuclearResearch HungarianAcademyofScience(ATOMKI)1-1-4001DebrecenPOBox51Hungary

With the help of the density operator, the angular differential cross-section for ionization of helium is calculated within the framework of the one-centre atomic-orbital close-coupling method. We consider a naked C6+ ion as projectile with an energy of 2.5MeV/a.u. Our result agrees well with the experimental data and the other theoretical calculations such as the first Born approximation, various Distorted Wave models and the classical trajectory Monte Carlo simulation.

关键词： Monte Carlo methods

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Cooling age of Dabie orogen, China, determined by ^(40)Ar-^(39)Ar and fission track techniques

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Science China Chemistry 1995年第6期38卷 749-757页

作者：陈江峰谢智刘顺生李学明 k.A.Foland Department of Earth and Space Sciences University of Science and Technology of China Hefei 230026 China Changsha Tectonic Institute Chnese Academy of Sciences Changsha 410013 Department of Geological Sciences Ohio State University Columbus OH 43210.USA

Based on 40Ar-39Ar results of hornblendes and biotites and fission track dating results of apatites separated from the same rock samples, cooling history of rocks from Dabie orogen is discussed. Rocks from both Southern Dabie Terrain (SDT) and Northern Dabie Terrain (NDT) have an early fast cooling followed by a more recent slow cooling. Rocks from SDT cooled to about 540℃ at about 190 Ma B.C., while rocks from NDT cooled to about 540℃ at 125 Ma B C. Until about 110-120 Ma B.C., rocks from both SDT and NDT cooled to about 100℃. This suggests that a relative movement among rocks from SDT, NDT and ul-Ira-high pressure metamorphic rocks exis-ts before 110-120 Ma B.C.

关键词： Dabie orogen cooling history 40Ar-39Ar dating fission track dating blocking temperature.

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