检索结果-南通市图书馆

Synthesis, crystal structure, magnetic properties and second harmonic generation of a new noncentrosymmetric coordination compound：Triaqua(4-amino-6-methoxypyrimidine) cuprate(Ⅱ)sulfate

引用

Chinese Chemical Letters 2016年第6期27卷 896-900页

作者： Mahjouba Ben Nasr Kamel Kaabi matthias zeller Wataru Fujita Pedro Sidónio Pereira da Silva Cherif Ben Nasr Laboratoire de Chimie des Materiaux Universite de Carthage Facultedes Sciences de Bizerte 7021 Zarzouna Tunisia Department of Chemistry Youngstown State University One University Plaza Youngstown OH 44555-3663 USA Graduate School of Natural Science Nagoya City University Yamanohata Mizuho-cho Mizuho-ku Nagoya 467-8501 Japan CFisUC Department of Physics University of Coimbra 3004-516 Coimbra Portugal

The chemical preparation, crystal structure and infrared spectroscopic characterization of the triaqua（4-amino-6-methoxypyrimidine） cuprate（II） sulfate, [Cu（C5H7N3）（H2O）3]SO4, is reported. The compound crystallizes in the noncentrosymmetric orthorhombic space group P212121 with lattice parameters a = 7.9025（3）, b = 11.1189（4）, c = 12.9720（4） , V = 1139.81（7） ~3 and Z = 4. The Cu（II） cation is fivecoordinated, in an early half-way between square pyramidal and trigonal bipyramidal fashion, by two nitrogen atoms of the 4-amino-6-methoxypyrimidine ligand and three water oxygen atoms. In the atomic arrangement, the organic ligands and the 5-connected Cu centers are linked with each other to give a 1-D corrugated hybrid chain running along the b-axis direction. The chains are interconnected by the SO4^（2-） anions via O–H...O, O–H...S, C–H...O and N–H...O hydrogen bonds to form layers spreading parallel to the（011） plane. The vibrational absorption bands were identified by infrared spectroscopy. Quantitative measurements of the second harmonic generation（SHG） of a powdered sample at 1064 nm were performed and a relative efficiency of 5.2 times the KDP standard was observed. Magnetic properties were also defined to characterize the complex. Magnetic measurements revealed that this material had a onedimensional antiferromagnetic character. The magnetic parameters were g = 2.11 and 2J/k B = -36 K.

关键词： Square pyramid Cu(II) complex X-ray diffraction Magnetic properties Second harmonic generation

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

双核钌-DMBA双芳香炔化合物的合成和电化学性质（英文）

引用

无机化学学报 2017年第11期33卷 2103-2109页

作者： Susannah D.Banziger Eileen C.Judkins matthias zeller 任彤 Department of Chemistry Purdue University

在弱碱性条件下,双核钌(Ⅲ)配合物Ru2(DMBA)4(NO3)2(DMBA=tetrakis-N,N′-dimethylbenzamidinate)与不同芳香炔反应(其中芳香基团包括:NAPme,N-甲基-1,8-萘二甲酰亚胺;NAPiso,N-异丙基-1,8-萘二甲酰亚胺;Naphth,萘;Ant,蒽),制备了相应的端基炔取代配合物trans-Ru2(DMBA)4(C2Ar)2(Ar=NAPme,1;NAPiso,2;Naphth,3;Ant,4)。利用X射线晶体衍射测定了它们的结构。所有化合物的Ru-Ru键长处于单键范围(0.245 0~0.249 1 nm),它们均是抗磁性物质。进一步通过1H NMR和UV-Vis-NIR光谱进行了表征。电化学研究表明,所有化合物显示出与芳香基团有关的2个可逆的单电子氧化还原过程(包括一个氧化过程和一个还原过程)。

关键词：双核钌炔基 1 8-萘二甲酰亚胺萘基蒽基

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Sulfur in the Pore:Tailoring Coordination Networks for Metal Uptake,Luminescent Sensing and Other Good Stuff

Sulfur in the Pore:Tailoring Coordination Networks for Metal...

引用

中国化学会第六届全国结构化学学术会议

作者： Ka-Kit Yee matthias zeller Allen D.Hunter Department of Biology and Chemistry City University of Hong KongTat Chee AvenueKowloonHong Kong S.A.R.P.R.China Department of Chemistry Youngstown State UniversityYoungstownOH 44555-3663USA

We utilize thioether and thiol groups for functionalizing metal-organic frameworks to facilitate the uptake and inclusion of metal *** example is TMBD,a terephthalic acid analog with four MeS-substituents. In one case,TMBD and Pb ions form a robust channel structure equipped with free-standing thioether groups to provide for a pioneering MOF system capable of reversible metal uptake(e.g.,HgCl).

关键词：

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Molecular and electronic structure of several 2,3-dithienylquinoxalines and their 2:1 complexes with silver(I) nitrate

引用

Open Journal of Inorganic Chemistry 2014年第1期4卷 10-17页

作者： Guy Crundwell Stefanie Cantalupo Paul D. C. Foss Brian McBurney Kristen Kopp Barry L. Westcott James Updegraff III matthias zeller Allen D. Hunter Department of Chemistry & Biochemistry Central Connecticut State University New Britain USA YSU Structure Center Department of Chemistry Youngstown State University Youngstown USA

We have synthesized three bis (thienyl) quinoxalinesilver(I) complexes;however, unlike analogous silver(I) complexes of pyridylquinoxaline that utilize (N, N) bidentate behavior from the quinoxaline and pyridyl ring nitrogens, the bis(thienyl) quinoxaline ligands did not utilize the bonding potential of the thienyl rings to give (N, S) bonding modes. PES spectra modeling of these ligands indicates that the preferential metal bonding via only the quinoxaline nitrogen atoms is due to the N-rich, but S-poor, characters of the frontier orbitals.

关键词： X-Ray Diffraction Silver(I) Complexes Thiophene Quinoxalines Photoelectron Spectroscopy

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Comparison of Cox Model Methods in A Low-dimensional Setting with Few Events

引用

Genomics, Proteomics & Bioinformatics 2016年第4期14卷 235-243页

作者： Francisco M. Ojeda Christian Miiller Daniela Bornigen David-Alexandre Tregouet Arne Schillert matthias Heinig Tanja zeller Renate B. Schnabel Department of General and Interventional Cardiology University Heart Center Hamburg-Eppendorf 20246 Hamburg Germany German Center for Cardiovascular Research (DZHK) Hamburg |Kiel| Luebeck Germany Sorbonne Universites University Pierre et Marie Curie Paris 06 Institut National pour la Sante et la Recherche Medicale (INSERM) Unite Mixte de Recherche en Sante (UMR_S) 1166 F-75013 Paris France Institute for Cardiometaholism and Nutrition (ICAN) F-75013 Paris France Institut fur Medizinische Biometrie und Statistik Universitat zu Lubeck Universitatsklinikum Schleswig-Holstein Campus Lubeck 23562 Lubeck Germany Institute of Computational Biology German Research Center for Environmental Health Helmholtz Zentrum Munchen 85764 Neuherberg Germany

Prognostic models based on survival data frequently make use of the Cox proportional hazards model. Developing reliable Cox models with few events relative to the number of predictors can be challenging, even in low-dimensional datasets, with a much larger number of observations than variables. In such a setting we examined the performance of methods used to estimate a Cox model, including （i） full model using all available predictors and estimated by standard techniques, （ii） backward elimination （BE）, （iii） ridge regression, （iv） least absolute shrinkage and selection operator （lasso）, and （v） elastic net. Based on a prospective cohort of patients with manifest coronary artery disease （CAD）, we performed a simulation study to compare the predictive accuracy, calibration, and discrimination of these approaches, Candidate predictors for incident cardiovascular events we used included clinical variables, biomarkers, and a selection of genetic variants associated with CAD. The penalized methods, i.e., ridge, lasso, and elastic net, showed a comparable performance, in terms of predictive accuracy, calibration, and discrimination, and outperformed BE and the full model. Excessive shrinkage was observed in some cases for the penalized methods, mostly on the simulation scenarios having the lowest ratio of a number of events to the number of variables. We conclude that in similar settings, these three penalized methods can be used interchangeably. The full model and backward elimination are not recommended in rare event scenarios.

关键词： Proportional hazards regression Penalized regression Events per variable Coronary artery disease

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Tree species richness enhances stand productivity while stand structure can have opposite effects, based on forest inventory data from Germany and the United States of America

引用

Forest Ecosystems 2018年第1期5卷 36-52页

作者： Laura zeller Jingjing Liang Hans Pretzsch Center of Life and Food Sciences Weihenstephan Technical University of MunichHans-Carl-von-Carlowitz-Platz 285354 FreisingGermany Division of Forestry and Natural Resources Davis College of AgricultureNatural Resources&DesignWest Virginia University340 Percival HallMorgantownWV 26506-6108USA

Background： in recent studies, mixed forests were found to be more productive than monocultures with everything else remaining the same. Methods： To find out if this productivity is caused by tree species richness, by a more heterogeneous stand structure or both, we analyzed the effects of forest structure and tree species richness on stand productivity, based on inventory data of temperate forests in the United States of America and Germany. Results： Having accounted for effects such as tree size and stand density, we found that：（I） tree species richness increased stand productivity in both countries while the effect of tree size heterogeneity on productivity was negative in Germany but positive in the USA; （11） productivity was highest at sites with an intermediate amount of precipitation; and （111） growth limitations due water scarcity or low temperature may enhance structural heterogeneity. Conclusions： In the context of forest ecosystem goods and services, as well as future sustainable forest resource management, the associated implications would be：

关键词： Big data Overyielding Tree size heterogeneity Tree species mixing Climate Biodiversity-productivityrelationship

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

In silico studies of magnesium-based implants: A review of the current stage and challenges

引用

Journal of Magnesium and Alloys 2022年第11期10卷 2968-2996页

作者： Tamadur Albaraghtheh Regine Willumeit-Römer Berit zeller-Plumhoff Helmholtz-Zentrum hereon GmbH Institute of Metallic BiomaterialsMax-Planck-Str.1Geesthacht 21502Germany

In silico methods to study biodegradable implants have recently received increasing attention due to their potential in reducing experimental time and cost. An important application case for in silico methods are magnesium(Mg)-based biodegradable implants, as they represent a powerful alternative to traditional materials used for temporary orthopaedic applications. Controlling Mg alloy degradation is critical to designing an implant that supports the bone healing process. To simulate different aspects of this biodegradation process, several mathematical models have been proposed with the ultimate aim of replacing laboratory experiments with computational modeling. In this review, we provide a comprehensive and critical discussion of the published models and their performance with respect to capturing the complexity of the biodegradation process. This complexity is presented initially. Additionally, the present review discusses the different approaches of optimizing and quantifying the different sources of errors and uncertainties within the proposed models.

关键词： Biodegradable implants Degradation In silico Phenomenological approach Physical approach Validation Verification Uncertainty quantification Mg

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Perianal fistulodesis–A pilot study of a novel minimally invasive surgical and medical approach for closure of perianal fistulae

引用

World Journal of Gastrointestinal Surgery 2021年第2期13卷 187-197页

作者： Roxanne Villiger Daniela Cabalzar-Wondberg Daniela zeller Pascal Frei Luc Biedermann Christian Schneider Michael Scharl Gerhard Rogler matthias Turina Andreas Rickenbacher Benjamin Misselwitz Department of Gastroenterology and Hepatology University Hospital of ZurichZurich 8091Switzerland Visceral-and Transplant Surgery University Hospital of ZurichZurich 8091Switzerland Department of Surgery Zeller SurgeryZurich 8008Switzerland Department of Gastroenterology University Hospital of ZurichZurich 8091Switzerland Visceral Surgery and Medicine University Hospital of BernBern 3010Switzerland

BACKGROUND Perianal fistulae strongly impact on quality of life of affected *** To challenge and novel minimally invasive treatment options are *** Patients with Crohn’s disease(CD)in remission and patients without inflammatory bowel disease(non-IBD patients)were treated with fistulodesis,a method including curettage of fistula tract,flushing with acetylcysteine and doxycycline,Z-suture of the inner fistula opening,fibrin glue instillation,and Zsuture of the outer fistula opening followed by post-operative antibiotic prophylaxis with ciprofloxacin and metronidazole for two *** with a maximum of 2 fistula openings and no clinical or endosonographic signs of a complicated fistula were *** primary end point was fistula healing,defined as macroscopic and clinical fistula closure and lack of patient reported fistula symptoms at 24 *** Fistulodesis was performed in 17 non-IBD and 3 CD patients,with a total of 22 *** 24 wk,all fistulae were healed in 4 non-IBD and 2 CD patients(overall 30%)and fistula remained closed until the end of follow-up at 10-25 *** a secondary per-fistula analysis,7 out of 22 fistulae(32%)were *** disease activity index(PDAI)improved in patients with fistula *** PDAI was associated with favorable outcome(P=0.0013).No serious adverse events were *** Fistulodesis is feasible and safe for perianal fistula *** success rates is at 30%comparable to other similar techniques.A trend for better outcomes in patients with low PDAI needs to be confirmed.

关键词： Fistula Fibrin glue Crohn's disease Perianal disease activity index Inflammatory bowel disease Fistula closure

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Costs of resistance to fungal pathogens in genetically modified wheat

引用

Journal of Plant Ecology 2013年第1期6卷 101-112页

作者： Simon L.zeller Olena Kalinina Bernhard Schmid Institute of Evolutionary Ecology and Environmental Studies University of ZurichWinterthurerstrasse 1908057 ZurichSwitzerland

Aims Many resistance genes against fungal pathogens show costs of *** modified(GM)plants that differ in only one or a few resistance genes from control plants present ideal systems for measuring these costs in the absence of *** To assess the ecological relevance of costs of pathogen resistance,we grew individual plants of four transgenic spring wheat lines in a field trial with three pathogen levels and varied the genetic diversity of the *** Findings We found that two lines with a Pm3b transgene were more resistant to powdery mildew than their sister lines of the variety Bobwhite,whereas lines with chitinase(A9)or chitinase and glucanase(A13)transgenes were not more resistant than their mother variety ***,in the absence of the pathogen,both the GM lines of Bobwhite as well as those of Frisal performed significantly worse than their controls,***3b#1 and Pm3b#2 had 39%or 53%and A9 and A13 had 14%or 23%lower *** the presence of the pathogen,all GM lines except Pm3b#2 could increase their yields and other fitness-related traits,reaching the performance levels of the control *** Pm3b#2 seemed to have lost its phenotypic plasticity and had low performance in all *** may have been caused by very high transgene *** synergistic effects of mixing different GM lines with each other were *** might have been due to high transgene expression or the similarity between the lines regarding their resistance *** conclude that costs of resistance can be high for transgenic plants with constitutive transgene expression and that this can occur even in cases where the non-transgenic control lines are already relatively resistant,such as in our variety *** plants could only compete with conventional varieties in environments with high pathogen ***,the large variability among the GM lines,which may be due to unpredictable transgene expression,su

关键词： powdery mildew resistance genes transgene expression transgene stacking yield

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Computational modelling of magnesium degradation in simulated body fluid under physiological conditions

引用

Journal of Magnesium and Alloys 2022年第4期10卷 965-978页

作者： Berit zeller-Plumhoff Tamadur AlBaraghtheh Daniel Höche Regine Willumeit-Römer Helmholtz-Zentrum hereon GmbH Institute of Metallic BiomaterialsMax-Planck-Straße 1Geesthacht21502Germany Helmholtz-Zentrum hereon GmbH Institute of Surface ScienceMax-Planck-Straße 1Geesthacht21502Germany

Magnesium alloys are highly attractive for the use as temporary implant materials, due to their high biocompatibility and ***, the prediction of the degradation rate of the implants is difficult, therefore, a large number of experiments are required. Computational modelling can aid in enabling the predictability, if sufficiently accurate models can be established. This work presents a generalized model of the degradation of pure magnesium in simulated body fluid over the course of 28 days considering uncertainty aspects. The model includes the computation of the metallic material thinning and is calibrated using the mean degradation depth of several experimental datasets simultaneously. Additionally, the formation and precipitation of relevant degradation products on the sample surface is modelled, based on the ionic composition of simulated body fluid. The computed mean degradation depth is in good agreement with the experimental data(NRMSE=0.07). However, the quality of the depth profile curves of the determined elemental weight percentage of the degradation products differs between elements(such as NRMSE=0.40 for phosphorus vs. NRMSE=1.03 for magnesium). This indicates that the implementation of precipitate formation may need further developments. The sensitivity analysis showed that the model parameters are correlated and which is related to the complexity and the high computational costs of the model. Overall, the model provides a correlating fit to the experimental data of pure Mg samples of different geometries degrading in simulated body fluid with reliable error estimation.

关键词： Biodegradation Magnesium Computational modelling Corrosion Uncertainty quantification Kriging

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：