检索结果-南通市图书馆

Does intra-ruminal nitrogen recycling waste valuable resources? A review of major players and their manipulation

在线全文

学校读者我要写书评

暂无评论

Journal of Animal Science and Biotechnology 2018年第3期9卷 497-517页

作者： Thomas Hartinger Nina Gresner karl-Heinz Südekum Institute of Animal Science University of Bonn

Nitrogenous emissions from ruminant livestock production are of increasing public concern and, together with methane, contribute to environmental pollution. The main cause of nitrogen-(N)-containing emissions is the inadequate provision of N to ruminants, leading to an excess of ammonia in the rumen, which is subsequently excreted. Depending on the size and molecular structure, various bacterial, protozoal and fungal species are involved in the ruminal breakdown of nitrogenous compounds(NC). Decelerating ruminal NC degradation by controlling the abundance and activity of proteolytic and deaminating microorganisms, but without reducing cellulolytic processes, is a promising strategy to decrease N emissions along with increasing N utilization by ruminants. Different dietary options, including among others the treatment of feedstuffs with heat or the application of diverse feed additives, as well as vaccination against rumen microorganisms or their enzymes have been evaluated. Thereby, reduced productions of microbial metabolites, e.g. ammonia, and increased microbial N flows give evidence for an improved N retention. However, linkage between these findings and alterations in the rumen microbiota composition, particularly NC-degrading microbes, remains sparse and contradictory findings confound the exact evaluation of these manipulating strategies, thus emphasizing the need for comprehensive research. The demand for increased sustainability in ruminant livestock production requests to apply attention to microbial N utilization efficiency and this will require a better understanding of underlying metabolic processes as well as composition and interactions of ruminal NC-degrading microorganisms.

关键词： Ammonia Bacteria Deamination Hyper-ammonia producing Nitrogen efficiency Protein Proteolysis Protozoa Ruminant

Embryology of Iris sanguinea Donn ex Horn. and its systematic relationship

在线全文

学校读者我要写书评

暂无评论

Journal of Forestry Research 2019年第6期30卷 2007-2020页

作者： Lijuan Fan karl H.Hasenstein Ling Wang College of Landscape Architecture Northeast Forestry UniversityHarbin 150040People’s Republic of China Department of Biology University of Louisiana at LafayetteLafayetteLA 70504USA

Iris sangumea Dorm ex Horn. is a perennial cold-tolerant herbs of the Iris genus of Iridaceae, which has a well-formed, bright color and adaptability. Through understanding the fl ower bud differentiation, Sporogenesis, gametogenesis, fertilization and embryogenesis of I. sangumea, we developed fl owering regulation and control breeding. I. sangumea fl ower bud differentiation was observed in April for 21 days; in this stage, the early differentiation process was slow, temperature was more than 5 °C, if the temperature is shorter than this, most fl ower bud will have no differentiation, and turn to vegetative growth; later differentiation is faster and required temperature is from 5 to 8 °C and gradually rose to 10-12 °C. The temperature in April plays the defi nitely role in the number of bud differentiation. Three stamina contain tetrasporangiate anthers and a glandular tapetum. The anther wall is composed of four cell layers inclduding the epidermis, the endothecium, one middle layer and the secretory tapetum. The type of anther wall development the dicotyledonous type. After pollen maturation, the anther wall forms a double-layer containing only epidermis and endothecium. Simultaneous cytokinesis is of the continuous type during meiosis of microspore mother cell results in a zygomorphous or tetragonal tetrad. Mature pollen grains are two-celled. I. sangumea ’s stylar canal is hollow, open type style, and the gynoecium has three carpels. The ovaries have axial placentas. The ovule is anatropous, bitegmic and crassinucellate. The primary sporogenous cell differentiates directly as the megaspore. The megaspore tetrads are linear, T-shaped or juxtaposed. Generally, the fi rst of the tetrad megaspores at the chalaza becomes functional while the other three degenerate. A mature embryo sac with seven cells and eight nuclei embryo sac is of the polygonum type. For dichogamy, the male gametophyte matures about 2 days earlier than the female gametophyte. The pollen tube e

关键词： Iris sanguinea Donn ex Horn Flower bud diff erentiation Embryology

PHOTOVISCOELASTICITY—AN EXPERIMENTAL METHOD IN VISCOELASTIC STRESS ANALYSIS

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 1987年第11期8卷 1019-1026页

作者： karl-Hans Laermann Bergische Universitat-Gesamthochschule Wuppertal West Germany

In this paper,the photoviscoelasticity method of viscoelastic stress analysis has beendiscussed in *** is shown that,in order to avoid the effects of shrinkage andaging in thetest specimens,it is suggested that the specimens should be tempered for three days at atemperature of 60℃ before starting the experiments,and the temperature filteringarrangement is recommended in the experimental setups to keep the temperature *** the axi-symmetrical time-dependent stress state,the determination of theprinciple axes of the refraction tensor experimentally remains an unsufficiently *** avoid dynamic effect in the step wise loading,the time of measurement in everystep should be limited in about one secend.

关键词： AN EXPERIMENTAL METHOD IN VISCOELASTIC STRESS ANALYSIS PHOTOVISCOELASTICITY

Plasma polymerized acetylene deposition using a return corona enhanced plasma reactor

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Plasma Science and Technology 2017年第8期19卷 90-96页

作者： Rokibul ISLAM Shuzheng XIE karl R ENGLUND Patrick D PEDROW School of Electrical Engineering and Computer Science Washington State University Composite Materials and Engineering Center Washington State University

A corona based weakly ionized plasma source was developed to deposit plasma polymerized acetylene coating at atmospheric pressure. The plasma source included a distinctive point-topoint geometry consisting of an array of high voltage needles and an array of protrusions placed over a grounded screen. The geometry facilitated various corona discharge modes that included return corona to contribute plasma polymerized acetylene deposition downstream from the corona section. Scanning probe techniques were used to investigate deposition on both the leading surface and the trailing surface of substrates. Deposition was initiated as distinct nodules that merged to form a thin plasma polymerized coating.

关键词： acetylene corona return nodules downstream initiated weakly nucleation resistive sized

China, the G20 and the International Investment Regime

在线全文

学校读者我要写书评

暂无评论

China & World Economy 2016年第4期24卷 73-92页

作者： karl P Sauvant Resident Senior Fellow Columbia Center on Sustainable Investment a joint center of Columbia Law School and the Earth Institute Columbia University USA

China has become a major home country for outward foreign direct investment （OFDI） flows. As a result, the country is increasingly concerned with protecting its OFDI and facilitating the operations of its firms investing abroad and creating a strong universal international investment law and policy regime. This article briefly reviews the emergence of China as an outward investor. It continues with an analysis of some policy issues related to the rise of FDIfrom emerging markets. A brief discussion of issues central to the future of the international investment law and policy regime follows, before focusing on several outcomes that could be pursued under China＇s G20 leadership： non- binding shared principles that could outline the architecture of a universal framework on international investment; an international support program for sustainable investment facilitation; and the creation of an additional intergovernmental platform that would allow for a continued systematic intergovernmental process to discuss the range of issues related to the governance of international investment, preferably paralleled by an informal, inclusive and result-oriented consensus-building process that takes place outside intergovernmental settings.

关键词： China foreign direct investment G20 international investment regime multinational enterprises

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Catalyzing n-doping

The Innovation 2022年第2期3卷 5-6页

作者： Guohua Xie karl Leo Sauvage Center for Molecular Sciences Hubei Key Lab on Organic and Polymeric Optoelectronic MaterialsDepartment of ChemistryWuhan UniversityWuhan 430072China Dresden Integrated Center for Applied Physics and Photonic Materials(IAPP)and Institute for Applied Physics Technische Universitat Dresden01187 DresdenGermany

Electrical doping,i.e.,inducing p-or n-type conductivity by adding a dopant,is of fundamental importance for device physics of semiconductors and is used in about every commercially produced *** organic semiconductors,the conductivity is intrinsically low(typically 10^(-4)-10^(-8) S/cm)due to the mostly amorphous nature,the weak coupling between molecules,and the low number of free charge carriers in the presence of large energy gaps.

关键词： dopant doping conductivity

Calcar-guided short-stem total hip arthroplasty: Will it be the future standard? Review and perspectives

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Orthopedics 2021年第8期12卷 534-547页

作者： karl Philipp Kutzner Department of Orthopaedic Surgery St Josefs Hospital WiesbadenGermanyWiesbaden 65189Germany Department of Hip Surgery Gelenkzentrum Rhein-MainWiesbaden 65183Germany Center of Orthopedics and Traumatology Johannes Gutenberg-University of MainzMainz 55131Germany

Short stems in total hip arthroplasty(THA)are becoming increasingly *** Germany,already 10.4%of all primary THAs are performed using a cementless short *** concept of modern,calcar-guided,short stems aims for an individualized reconstruction of the hip anatomy by following the calcar of the femoral neck,a bone-and soft-tissue-sparing implantation technique,and physiological *** stem design uses either metaphyseal fixation alone or additional diaphyseal anchoring,depending on the stem alignment and *** individualized anchorage types increase the potential indications for the safe use of a short *** design features may account for potential advantages of current short stem implants compared with earlier shortstem designs,particularly in cases of reduced bone quality or osteonecrosis of the femoral head and femoral neck *** implantation technique,however,requires distinct knowledge regarding the characteristics of varus and valgus positioning,with the potential for clinical consequences.A learning curve for surgeons new to this technique must be taken into *** contact with the distal lateral cortex appears to be crucial to provide sufficient primary stability,and the use of intraoperative imaging to identify“undersizing”is highly *** results of several national registries indicate that calcarguided short stems are among the most successful implants in terms of mid-term ***,long-term data remain *** review introduces the characteristics of calcar-guided short-stem THA and summarizes the current evidence.

关键词： Total hip arthroplasty Short stem Calcar-guided Classification Indications Anchorage Optimys

基于不同养分策略的亚热带常绿与落叶树种的共存机制

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

植物生态学报(英文版) 2023年第4期16卷 25-35页

作者： Xiaoping Chen Xingui Le karl JNiklas Dandan Hu Quanlin Zhong Dongliang Cheng College of Tourism and Resources Environment Zaozhuang UniversityZaozhuang 277160China Institute of Geography School of Geographical SciencesFujian Normal UniversityFuzhou 350007China Key Laboratory of Humid Subtropical Eco-geographical Process(Ministry of Education) College of Geographical SciencesFujian Normal UniversityFuzhou 350007China Fujian Provincial Key Laboratory of Plant Ecophysiology College of Geographical SciencesFujian Normal UniversityFuzhou 350007China Yangjifeng National Nature Reserve Administration YingtanChina Plant Biology Section School of Integrative Plant ScienceCornell UniversityIthaca 14850NYUSA

常绿和落叶树种共存于中国东南部的亚热带森林中。为探究常绿和落叶树种应对亚热带磷限制所采用的碳获取策略,我们选取阳际峰常绿阔叶林中75种共存的木本植物,包括44种常绿树种和31种落叶树种,测定了其叶片的光合和呼吸速率,以及与碳(C... 详细信息

常绿和落叶树种共存于中国东南部的亚热带森林中。为探究常绿和落叶树种应对亚热带磷限制所采用的碳获取策略,我们选取阳际峰常绿阔叶林中75种共存的木本植物,包括44种常绿树种和31种落叶树种,测定了其叶片的光合和呼吸速率,以及与碳(C)、氮(N)和磷(P)利用效率和再吸收效率的相关性状。落叶树种的光合氮利用效率(PNUE)、单位氮和磷的呼吸速率(R_(d,N)和R_(d,P))均显著高于常绿树种,但光合磷利用效率(PPUE)在二者之间无显著差异。对于任意给定的叶片P,常绿树种的碳利用效率(CUE)高于落叶树种。此外,落叶和常绿植物的氮再吸收效率(NRE)、磷再吸收效率(PRE)和N:P均无显著差异。这些结果表明,常绿树种维持高CUE使其在P限制的亚热带森林中成为优势树种。这些结果对其他生物群落中落叶和常绿物种的养分策略比较具有重要意义,也为未来的气候变化下的亚热带森林的群落动态建模提供了新见解。

关键词：光合养分利用效率碳利用效率氮吸收效率磷吸收效率物种共存

Multimodal 4-arylchromene derivatives with microtubule-destabilizing,anti-angiogenic,and MYB-inhibitory activities

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Cancer Drug Resistance 2023年第1期6卷 59-77页

作者： Leonhard H.F.Kohler Sebastian Reich Maria Yusenko karl-Heinz Klempnauer Gerrit Begemann Rainer Schobert Bernhard Biersack Organic Chemistry Laboratory University of BayreuthBayreuth 95440Germany Institute for Biochemistry Westfalische-Wilhelms-UniversitatMunster 48149Germany Developmental Biology University of BayreuthBayreuth 95440Germany

Aim:Efficient and readily available anticancer drugs are sought as treatment *** this reason,chromene derivatives were prepared using the one-pot reaction and tested for their anticancer and anti-angiogenic ***:2-Amino-3-cyano-4-(aryl)-7-methoxy-4H-chromene compounds(2A-R)were repurposed or newly synthesized via a three-component reaction of 3-methoxyphenol,various aryl aldehydes,and *** performed assays to study the inhibition of tumor cell growth[3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromid(MTT)assay],effects on microtubules(immunofluorescence),cell cycle(flow-activated cell sorting analysis),angiogenesis(zebrafish model),and MYB activity(luciferase reporter assay).Fluorescence microscopy was applied for localization studies via copper-catalyzed azide-alkyne click reaction of an alkyne-tagged drug ***:Compounds 2A-C and 2F exhibited robust antiproliferative activities against several human cancer cell lines(50%inhibitory concentrations in the low nanomolar range)and showed potent MYB *** alkyne derivative 3 was localized in the cytoplasm after only 10 min of *** microtubule disruption and G2/M cell-cycle arrest were observed,where compound 2F stood out as a promising microtubule-disrupting *** study of anti-angiogenic properties showed that 2A was the only candidate with a high potential to inhibit blood vessel formation in ***:The close interplay of various mechanisms,including cell-cycle arrest,MYB inhibition,and anti-angiogenic activity,led to identifying promising multimodal anticancer drug candidates.

关键词： Chromene pyran anticancer drugs microtubule angiogenesis MYB inhibition