bluuebunny/crossref_metadata_2025 huggingface dataset:
An analytical model for soil-atmosphere feedback
Authors: Schaefli B. , van der Ent R. J. , Woods R. , Savenije H. H. G.
Published: September 2011

Abstract. Soil-atmosphere feedback is a key for understanding the hydrological cycle and the direction of potential system changes. This paper presents an analytical framework to study the interplay between soil and atmospheric moisture, using as input only the boundary conditions at the upstream end of an atmospheric moisture stream line. The underlying Eulerian-Langrangean approach assumes advective moisture transport with average wind speed along the stream line and vertical moisture exchange with the soil compartment of uniform vertical properties. Precipitation, evaporation from interception and runoff are assumed to depend through simple functional relationships on the soil moisture or the atmospheric moisture. Evaporation from soil moisture (including transpiration) depends on both state variables, which introduces a nonlinear relationship between the two compartments. This nonlinear relationship can explain some apparently paradoxical phenomena such as a local decrease of precipitation accompanied by a runoff increase. The solutions of the resulting water balance equations correspond to two different moisture regimes along a stream line, either monotonically increasing or decreasing when traveling inland, depending on boundary conditions and parameters. The paper discusses how different model parameters (e.g. time scales of precipitation, evaporation or runoff) influence these regimes and how they can create regime switches. Such an analysis has potential to anticipate the range of possible land use and climate changes or to interpret the results of complex land-atmosphere interaction models. Based on derived analytical expressions for the Horton index, the Budyko curve and a precipitation recycling ratio, the analytical framework opens new perspectives for the classification of hydrological systems.
A chaotically driven model climate: extreme events and snapshot attractors
Authors: Bódai T. , Károlyi Gy. , Tél T.
Published: September 2011

Abstract. In a low-order chaotic global atmospheric circulation model the effects of deterministic chaotic driving are investigated. As a result of driving, peak-over-threshold type extreme events, e.g. cyclonic activity in the model, become more extreme, with increased frequency of recurrence. When the characteristic time of the driving is comparable to that of the undriven system, a resonance effect with amplified variance shows up. For very fast driving we find a reduced enhancement of variance, which is also the case with white noise driving. Snapshot attractors and their natural measures are determined as a function of time, and a resonance effects is also identified. The extreme value statistics of group maxima is found to follow a Weibull distribution.
Empirical Look at the Factors Affecting Perception of Business Ethics in Turkey
Authors: Akman Vedat
Published: September 2011

This study aims to explore the influence of gender, age, education, profession and sector choices towards factors affecting business ethics in Turkey. Self-administered questionnaire with scale of 1-5 was used to measure attitudes towards business ethics (1= "strongly agree" to 5="strongly disagree") with reasonable good score on Cronbach's realibility test. With Cronbach alpha of .692 and KMO (Kaiser-Meyer-Olkin Meaure of Sampling Adequecy) .746 (which sould be greater than .5 for a satisfactor analysis) we proceeded to our analysis successfully.  Choice job, sector, age and gender were significant determinants to factors affecting perception of business ethics but education level was not a significant determinant.
A Simulation Set-up to Observe the Effects of the Emotional Factor on Capital Markets
Authors: Ozturkkal Belma
Published: September 2011

The study surveyed 74 student subjects from a major public university in the southern United States in a capital market experiment. This study investigates the link between profitability and the individual emotions present at the time of the experiment among managers and investors. This study is motivated by the shareholder and manager mechanism simulating a real market environment, where the individual self-reported emotions on a survey are analyzed by a least square regression analysis from the perspective of investors and managers.
Relation of dry eye to disease activity in juvenile rheumatoid arthritis
Authors: El-Shazly Amany Abdel-Fattah , Mohamed Ahmed Abdullah
Published: September 2011

Purpose

To study the frequency and severity of dry eye in patients with juvenile rheumatoid arthritis (JRA) and its relation to disease activity.

Patients and Methods

Evaluation for dry eye was done in 40 patients with juvenile rheumatoid arthritis referred for ocular assessment in the Ophthalmology Clinics, Faculty of Medicine, Ain Shams University. They were 28 girls and 12 boys with age range of 7–12 years. Medical history, clinical examination, and full ophthalmologic evaluation were performed for each patient. The dry eye tests included tear film break-up time, Schirmer-1 test, and corneal fluorescein staining. Dry eye severity grading was used. Twenty healthy, age- and sex-matched children were assessed for dry eye as a control group.

Results

Thirty patients (75%) showed findings consistent with the diagnosis of dry eye. Twenty patients (50%) showed first-degree dryness, 8 (20%) showed second-degree, and 2 (5%) showed third-degree. The score of dry eye severity was significantly lower in remission compared to disease activity. Multiregression analysis showed the only factor affecting dry eye parameters was the duration of illness.

Conclusions

Dry eye is a common incident in children with JRA and should be screened for in all patients with this disease. Severity of eye dryness is highly correlated with the disease activity.
Prevalence and risk factors for diabetic retinopathy: an Iranian eye study
Authors: Heydari Behrouz , Yaghoubi Gholamhossein , Yaghoubi Mohammad Ali , Miri Mohammad Reza
Published: September 2011

Purpose

The aim of this study was to determine the prevalence of diabetic retinopathy among diabetic patients in Iran and its association with some predisposing factors.

Methods

All diabetic patients who attended the diabetes clinic underwent ocular examination, including slit-lamp biomicroscopy. The blood pressure and blood biochemical parameters were then measured.

Results

The prevalence of diabetic retinopathy among 1022 diabetic participants was 23.6% (241 cases). This study showed that there is a statistically significant relation between diabetic retinopathy and mean blood pressure, fasting blood sugar, blood urea nitrogen, and level of HbA1c. There was no difference in lipid profile between patients with and without retinopathy. The duration of diabetes was a predicting factor for retinopathy as well as presence of renal and cardiovascular diseases and fasting glucose >126 as independent variables.

Conclusions

The duration of diabetes was the most important risk factor for progression of retinopathy.
Prognostic Significance of GRP78 Expression Patterns in Breast Cancer Patients Receiving Adjuvant Chemotherapy
Authors: Baptista Mauricio Z. , Sarian Luis Otavio , Vassallo José , Pinto Glauce A. , Soares Fernando A. , de Souza Gustavo Antonio
Published: September 2011

This study examined the associations between GRP78 expression and breast cancer recurrence and survival in patients treated with anthracyclines in the adjuvant setting. GRP78 expression was assessed in 106 stage II/III breast cancer patients. Tissue microarray was used to perform immunohistochemistry and to determine the GRP78 expression in endoplasmic reticulum and cell membrane of breast tumors. Four distinct scenarios (low and high thresholds) were developed. For high thresholds, 16% and 40% of our cases were GRP78-positive for endoplasmic reticulum and cell membrane, respectively. For low thresholds, 74% and 87% of our cases were GRP78-positive for endoplasmic reticulum and cell membrane, respectively. In the endoplasmic reticulum high-threshold scenario, GRP78 positive was found to be significantly frequent in T3 tumors (p=0.02), and inversely related to ERBB2 overexpression (p=0.03). There was a lower proportion of GRP78-positive cases among women between 50 and 65 years of age (p=0.02). In the endoplasmic reticulum low-threshold scenario, the proportion of GRP78-positive cases was significantly higher in women younger than 50 years and in those who were premenopausal (p=0.04). No statistically significant difference was found in survival probabilities among the scenarios examined. In our cohort, GRP78 overexpression was not a predictor of overall or disease-free survival of patients receiving anthracycline-based adjuvant chemotherapy.
A Status Update of Modified Oligonucleotides for Chemotherapeutics Applications
Authors: Sanghvi Yogesh S.
Published: September 2011

This unit presents an update of recent developments and clinical progress in chemically modified oliogonucleotides useful for therapeutic applications. During the last decade, the number of therapeutic oligonucleotides in clinical trials has nearly tripled. This is primarily due to advances in the synthesis protocols, better understanding of the biology, improved delivery, and better formulation technologies. Currently, over 100 clinical trials with oligonucleotide‐based drugs are ongoing in the United States for potential treatment of a variety of life‐threatening diseases. Among various oligonucleotides, antisense technology has been at the forefront, with one product on the market. Antisense technologies represent about half of the active clinical trials. Similarly, siRNA, aptamers, spiegelmers microRNA, shRNA, IMO, and CpG have been other active classes of oligonucleotides that are also undergoing clinical trials. This review attempts to summarize the current status of synthesis, chemical modifications, purification, and analysis in light of the rapid progress with multitude of oligonucleotides pursued as therapeutic modality. Curr. Protoc. Nucleic Acid Chem. 46:4.1.1‐4.1.22. © 2011 by John Wiley & Sons, Inc.
Preparation of Photoresponsive DNA Tethering Ortho‐Methylated Azobenzene as a Supra‐Photoswitch
Authors: Asanuma Hiroyuki , Nishioka Hidenori , Ishikawa Teruchika , Liang Xingguo
Published: September 2011

This unit describes synthetic procedures of photoresponsive DNA via a phosphoramidite monomer composed of D‐threoninol as a scaffold and 4‐carboxy‐2′,6′‐dimethylazobenzene or 4‐carboxy‐2′‐methylazobenzene that works as a photoswitch more efficiently than previous nonmodified azobenzene (4‐phenylazobenzoic acid). With these newly modified‐azobenzenes, photoregulatory efficiency of DNA hybridization can be greatly improved. Furthermore, thermal stability of cis‐azobenzene of 4‐carboxy‐2′,6′‐dimethylazobenzene remarkably increases compared with the previous non‐modified azobenzene. Curr. Protoc. Nucleic Acid Chem. 46:4.45.1‐4.45.18. © 2011 by John Wiley & Sons, Inc.
Use of Chromophoric Ligands to Visually Screen Co‐Crystals of Putative Protein‐Nucleic Acid Complexes
Authors: Jiang Xiaohua , Egli Martin
Published: September 2011

Distinguishing between crystals of protein‐nucleic acid complexes and those containing protein alone is a common problem in structural studies of protein‐nucleic acid interactions. Currently, there are several methods available for detecting nucleic acid in crystals, including gel electrophoresis, SYBR Gold fluorescence dye staining, and methyl violet staining. However, they require either that the crystals be sacrificed or access to a fluorescence microscope. In this protocol, we describe an approach that allows direct visualization of either the presence or absence of oligonucleotides in crystals grown from solutions containing both protein and nucleic acid—labeling with the Cy5 dye. In addition to offering the advantage of being able to distinguish between crystals of complex and protein alone with the naked eye or a light microscope, crystals of covalently Cy5‐labeled DNA can be directly used for X‐ray diffraction data collection. Curr. Protoc. Nucleic Acid Chem. 46:7.15.1‐7.15.8. © 2011 by John Wiley & Sons, Inc.
Gene Identification in Prokaryotic Genomes, Phages, Metagenomes, and EST Sequences with GeneMarkS Suite
Authors: Borodovsky Mark , Lomsadze Alex
Published: September 2011

This unit describes how to use several gene‐finding programs from the GeneMark line developed for finding protein‐coding ORFs in genomic DNA of prokaryotic species, in genomic DNA of eukaryotic species with intronless genes, in genomes of viruses and phages, and in prokaryotic metagenomic sequences, as well as in EST sequences with spliced‐out introns. These bioinformatics tools were demonstrated to have state‐of‐the‐art accuracy and have been frequently used for gene annotation in novel nucleotide sequences. An additional advantage of these sequence‐analysis tools is that the problem of algorithm parameterization is solved automatically, with parameters estimated by iterative self‐training (unsupervised training). Curr. Protoc. Bioinform. 35:4.5.1‐4.5.17. © 2011 by John Wiley & Sons, Inc.
Eukaryotic Gene Prediction Using GeneMark.hmm‐E and GeneMark‐ES
Authors: Borodovsky Mark , Lomsadze Alex
Published: September 2011

This unit describes how to use the gene‐finding programs GeneMark.hmm‐E and GeneMark‐ES for finding protein‐coding genes in the genomic DNA of eukaryotic organisms. These bioinformatics tools have been demonstrated to have state‐of‐the‐art accuracy for many fungal, plant, and animal genomes, and have frequently been used for gene annotation in novel genomic sequences. An additional advantage of GeneMark‐ES is that the problem of algorithm parameterization is solved automatically, with parameters estimated by iterative self‐training (unsupervised training). Curr. Protoc. Bioinform. 35:4.6.1‐4.6.10. © 2011 by John Wiley & Sons, Inc.
Towards Engineering Nanoporous Platinum Thin Films for Highly Efficient Catalytic Applications
Authors: Jung Hyun Young , Kim Do Hyung , Chun Hyun Kyung , Kim Sang Hoon , Lim Chae Sun , Byun Ji Young , Jung Yung Joon
Published: September 2011

Porous metals attract significant interest for use in diverse electrochemical catalytic applications. However the fabrication of scalable and controlled porous metal structures on the nanoscale, particularly with highly catalytic pure Pt, still remains a significant challenge. We demonstrate highly engineered nanoporous Pt thin films by the dealloying of a Pt‐Si binary alloy system with a predetermined alloy composition. Controlled pore dimensions and nanostructures are obtained by tailoring the Pt‐Si alloy composition followed by selective Si etching. As a result, isotropic open nanopores are formed in continuous Pt ligaments and the porosity becomes larger on increasing the Si/Pt atomic ratio, which leads to the formation of a higher surface area and active catalytic sites. The formed nanoporous Pt film shows a 32‐times‐higher catalytic activity than Pt/C catalysts, with a high current density and low charge‐transfer resistance during methanol electro‐oxidation. The results reported here open up possibilities to develop high‐performance and reliable catalytic electrodes in energy and environmental applications.
Komplexe von N‐heterocyclischen Carbenen mit Boranen: Synthese und Reaktionen
Authors: Curran Dennis P. , Solovyev Andrey , Makhlouf Brahmi Malika , Fensterbank Louis , Malacria Max , Lacôte Emmanuel
Published: September 2011

Borane sind weit verbreitete Lewis‐Säuren, und N‐heterocyclische Carbene (NHCs) sind beliebte Lewis‐Basen. Dennoch war bis in die jüngste Zeit erstaunlich wenig über Komplexe dieser beiden Verbindungsklassen miteinander bekannt. NHC‐Borane sind leicht herzustellen, und teilweise sind sie so stabil, dass sie weniger als Komplex, sondern vielmehr als eigenständige organische Verbindung betrachtet werden können. Sie verhalten sich nicht wie klassische Borane, und sie können ein breites Spektrum an funktionellen Gruppen enthalten. Als vielseitige Reaktionspartner, Reagentien und Katalysatoren verfügen NHC‐Borane über ein immenses Potenzial für die organische Synthese und die Polymerchemie. Viele Reaktionen von NHC‐Boranen laufen über neue reaktive Intermediate wie Boreniumkationen, Borylradikale und sogar Borylanionen ab. Hier geben wir eine umfassende Übersicht über die Synthese, Charakterisierung und Reaktionen von NHC‐Boranen.
Selective hydrosilylation of ketones catalyzed by in situ‐generated iron NHC complexes
Authors: Buitrago Elina , Zani Lorenzo , Adolfsson Hans
Published: September 2011

Aryl alkyl‐, heteroaryl alkyl‐ and dialkyl ketones were readily reduced to their corresponding secondary alcohols in high yields, using the commercially available and inexpensive polymeric silane polymethylhydrosiloxane (PMHS), as reducing agent. The reaction is catalyzed by an in situ‐generated iron complex, conveniently generated from iron(II) acetate and the commercially available N‐heterocyclic carbene (NHC) precursor IPr·HCl. Copyright © 2011 John Wiley & Sons, Ltd.
From poly(dialkylstannane)s to poly(diarylstannane)s: comparison of synthesis methods and resulting polymers
Authors: Lechner Marie‐Luise , Trummer Markus , Bräunlich Irene , Smith Paul , Caseri Walter , Uhlig Frank
Published: September 2011

The efficiency and applicability of three different methods to synthesize polystannanes with different side chains are described. By means of dehydrogenative coupling utilizing the transition metal catalyst RhCl(PPh3)3 (Wilkinson's catalyst), n‐Bu2SnH2 reached the highest molar masses. Dehydrogenetive coupling in the presence of tetramethylethylenediamine could be best employed for (4‐n‐BuPh)2SnH2. Wurtz coupling using sodium in liquid ammonia was best suited for Ph2SnCl2. Next to the above‐mentioned educts, n‐Bu(Ph)SnX2 (X = H or Cl (as appropriate for the particular route) was used for polymerization resulting in one of so far rare example of asymmetric polystannanes with high molecular masses. Copyright © 2011 John Wiley & Sons, Ltd.
Polymer‐supported macrocyclic Schiff base palladium complex as an efficient catalyst for the Heck reaction
Authors: He Ying , Cai Chun
Published: September 2011

A polymer‐supported macrocyclic Schiff base palladium complex has been synthesized. In the Heck reaction of aryl iodides and bromides with ethyl acrylate or styrene, the complex has been proved to give the corresponding products in good to excellent yields. The reaction proceeded smoothly in the presence of 0.5 mol% of catalyst in DMF within 1–4 h. Recycling studies have shown that the catalyst can be readily recovered and reused for four cycles with only a slightly decrease in its activity. Copyright © 2011 John Wiley & Sons, Ltd.
Catalytic activity of cycloaurated complexes in the addition of 2‐methylfuran to methyl vinyl ketone
Authors: Kilpin Kelly J. , Jarman Bevan P. , Henderson William , Nicholson Brian K.
Published: September 2011

Cycloaurated gold(III) complexes derived from cycloaurated iminophosphorane, triphenylphosphine sulfide or selenide, or pyridylsulfonamide ligands have been assessed for their catalytic activity in the addition of 2‐methylfuran to methyl vinyl ketone. Addition of AgBF4 was generally needed for high activity, although those with coordinated atoms of high trans influence showed some activity in the absence of added Ag+. Copyright © 2011 John Wiley & Sons, Ltd.
Self‐complementary multiple hydrogen bonding interactions increase the glass transition temperatures to supramolecular poly(methyl methacrylate) copolymers
Authors: Kuo Shiao‐Wei , Tsai Hsin‐Tung
Published: September 2011

We have prepared a series of poly(methyl methacrylate) (PMMA)‐based copolymers through free radical copolymerization of methyl methacrylate in the presence of 2‐ureido‐4[1H]‐pyrimidinone methyl methacrylate (UPyMA). The glass transition temperature was increased with the increase of UPyMA contents in PMMA copolymers due to strong self‐complementary multiple hydrogen bonding interactions of UPy moiety. The Fourier transform infrared and solid‐state NMR spectroscopic analyses provided positive evidence for the presence of multiple hydrogen bonds interaction of UPy moiety. Furthermore, the proton spin‐lattice relaxation time in the rotating frame [T1ρ(H)] for the PMMA copolymers had a single value that was less than pure PMMA, indicating the smaller domain sizes in PMMA copolymers. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Use of a Plackett–Burman statistical design to determine the effect of selected amino acids on monoclonal antibody production in CHO cells
Authors: González‐Leal I. J. , Carrillo‐Cocom L. M. , Ramírez‐Medrano A. , López‐Pacheco F. , Bulnes‐Abundis D. , Webb‐Vargas Y. , Alvarez M. M.
Published: September 2011

Culture media design is central to the optimization of monoclonal antibody (mAb) production. Although general strategies do not currently exist for optimization of culture media, the combined use of statistical design and analysis of experiments and strategies based on simple material balances can facilitate culture media design. In this study, we evaluate the effect of selected amino acids on the growth rate and monoclonal antibody production of a Chinese hamster ovary DG‐44 (CHO‐DG44) cell line. These amino acids were selected based on their relative mass fraction in the specific mAb produced in this study, their consumption rate during bioreactor experiments, and also through a literature review. A Plackett–Burman statistical design was conducted to minimize the number of experiments needed to obtain statistically relevant information. The effect of this set of amino acids was evaluated during exponential cell culture (considering viable cell concentration and the specific growth rate as main output variables) and during the high cell‐density stage (considering mAb final concentration and specific productivity as relevant output variables). For this particular cell line, leucine (Leu) and arginine (Arg) had the highest negative and positive effects on cell viability, respectively; Leu and threonine (Thr) had the highest negative effect on growth rate, and valine (Val) and Arg demonstrated the highest positive impact on mAb final concentration. Results suggest the pertinence of a two‐stage strategy for amino acid supplementation, with a mixture optimized for cell growth and a different amino acid mixture for mAb production at high density. © 2011 American Institute of Chemical Engineers Biotechnol. Prog., 2011
Finite element implementation for computer‐aided education of structural mechanics: Mohr's circle and its practical use
Authors: Lee Jae Young , Ryu Hee Ryong , Park Young Taek
Published: September 2011

This article introduces a computer program for computer‐aided education about Mohr's circle and its practical use. The instructional tool has been implemented as part of a finite element analysis program, VisualFEA. The proposed approach to teaching and learning Mohr's circle is distinguished from previous work by its association with practical analysis models. The Mohr's circle is displayed and operated on the basis of stress data obtained from finite element analysis whereas arbitrarily assumed numerical values are used in other programs. The analysis can be extended to elasto‐plastic models with various yield criteria. Thus, the program can be regarded not only as an instructional module for studying Mohr's circle itself, but also as a training tool for exercising its practical application. This article describes the characteristics of the program's educational features and suggests important points for teaching and learning Mohr's circle and related subjects using VisualFEA. © 2011 Wiley Periodicals, Inc. Comput Appl Eng Educ 22:494–508, 2014; View this article online at wileyonlinelibrary.com/journal/cae; DOI 10.1002/cae.10.1002/cae.20575
Perchloropyracylene and its Fusion with C60 by Chlorine‐Assisted Radio‐Frequency Furnace Synthesis
Authors: Mueller Andreas , Ziegler Karolin , Amsharov Konstantin Yu. , Jansen Martin
Published: September 2011

Elusive perchloropyracylene has been obtained during conventional fullerene synthesis in a chlorine‐containing atmosphere by using the radio‐frequency furnace technique. In contrast to its hydrocarbon analogue, the title compound was found to be unexpectedly stable. Although the high stability of perchloropyracylene impedes its direct addition to C60 fullerene, the corresponding adduct was found in the synthesis products extracted from the raw soot. Both new species were separated and unambiguously characterized by single‐crystal X‐ray analysis. According to experimental observations and quantum chemical calculations, the addition of perchloropyracylene to the C60 fullerene can only be realized by involving highly reactive species such as C14 clusters displaying the pyracylene connectivity. Such a viable mechanism includes capturing of free or partially chlorinated C14 clusters with pyracylene‐type connectivity by the fullerene molecule and subsequent stabilization through chlorine addition. The data obtained provide experimental evidence for the presence of pyracylene‐like C14 clusters in the gas phase, which have evolved during the graphite vaporization process. According to the pentagon road mechanism, such clusters are regarded as crucial intermediates in fullerene formation.
Exercises in Pyrrolidine Chemistry: Gram Scale Synthesis of a Pro–Pro Dipeptide Mimetic with a Polyproline Type II Helix Conformation
Authors: Reuter Cédric , Huy Peter , Neudörfl Jörg‐Martin , Kühne Ronald , Schmalz Hans‐Günther
Published: September 2011

A practical and scalable synthesis of a Fmoc‐protected tricyclic dipeptide mimetic (6), that is, a 1,4‐diaza‐tricyclo‐[8.3.03, 7]‐tridec‐8‐ene derivative resembling a rigidified di‐L‐proline in a polyproline type II (PPII) helix conformation, was developed. The strategy is based on a Ru‐catalyzed ring‐closing metathesis of a dipeptide (4) prepared by PyBOP coupling of cis‐5‐vinylproline tert‐butylester (2) and trans‐N‐Boc‐3‐vinylproline (rac‐3) followed by chromatographic diastereomer separation. Building block 2 was prepared from L‐proline in six steps via electrochemical C5‐methoxylation, cyanation and conversion of the nitrile into a vinyl substituent. Building block rac‐3 was prepared in five steps exploiting a Cu‐catalyzed 1,4‐addition of vinyl‐MgBr to a 2,3‐dehydroproline derivative in the key step. In the course of the investigation subtle dependencies of protecting groups on the reactivity of the 2,3‐ and 2,5‐disubstituted pyrrolidine derivatives were observed. The configuration and conformational preference of several intermediates were determined by X‐ray crystallography. The developed synthesis allows the preparation of substantial amounts of 6, which will be used in the search for new small molecules for the modulation of protein–protein interactions involving prolin‐rich motifs (PRDs).
trans‐[Pt(BCat′)Me(PCy3)2]: An Experimental Case Study of Reductive Elimination Processes in Pt–Boryls through Associative Mechanisms
Authors: Braunschweig Holger , Bertermann Rüdiger , Brenner Peter , Burzler Michael , Dewhurst Rian D. , Radacki Krzysztof , Seeler Fabian
Published: September 2011

A stable trans‐(alkyl)(boryl) platinum complex trans‐[Pt(BCat′)Me(PCy3)2] (Cat′=Cat‐4‐tBu; Cy=cyclohexyl=C6H11) was synthesised by salt metathesis reaction of trans‐[Pt(BCat′)Br(PCy3)2] with LiMe and was fully characterised. Investigation of the reactivity of the title compound showed complete reductive elimination of Cat′BMe at 80 °C within four weeks. This process may be accelerated by the addition of a variety of alkynes, thereby leading to the formation of the corresponding η2‐alkyne platinum complexes, of which [Pt(η2‐MeCCMe)(PCy3)2] was characterised by X‐ray crystallography. Conversion of the trans‐configured title compound to a cis derivative remained unsuccessful due to an instantaneous reductive elimination process during the reaction with chelating phosphines. Treatment of trans‐[Pt(BCat′)Me(PCy3)2] with Cat2B2 led to the formation of CatBMe and Cat′BMe. In the course of further investigations into this reaction, indications for two indistinguishable reaction mechanisms were found: 1) associative formation of a six‐coordinate platinum centre prior to reductive elimination and 2) σ‐bond metathesis of BB and CPt bonds. Mechanism 1 provides a straightforward explanation for the formation of both methylboranes. Scrambling of diboranes(4) Cat2B2 and Cat′2B2 in the presence of [Pt(PCy3)2], fully reductive elimination of CatBMe or Cat′BMe from trans‐[Pt(BCat′)Me(PCy3)2] in the presence of sub‐stoichiometric amounts of Cat2B2, and evidence for the reversibility of the oxidative addition of Cat2B2 to [Pt(PCy3)2] all support mechanism 2, which consists of sequential equilibria reactions. Furthermore, the solid‐state molecular structure of cis‐[Pt(BCat)2(PCy3)2] and cis‐[Pt(BCat′)2(PCy3)2] were investigated. The remarkably short BB separations in both bis(boryl) complexes suggest that the two boryl ligands in each case are more loosely bound to the PtII centre than in related bis(boryl) species.
Operation reduced low‐density parity‐check decoding algorithms for low power communication systems
Authors: Lin Chia‐Yu , Chou Shu‐Cheng , Ku Mong‐Kai
Published: September 2011

Decoding operation reduction algorithms on min‐sum layered low‐density parity‐check (LDPC) decoders are proposed in this paper. Our algorithm freezes selected operations in high reliable nodes to reduce power while preserving error correcting performance. Both memory accesses and active node switching activities can be reduced. A novel node refresh mechanism reactivates frozen nodes to minimize coding gain degradation. We propose three decoding operation reduction algorithm variations to trade‐off complexity and operation reduction for LDPC decoders with different degrees of parallelism and memory requirement. Simulation results show that the number of LDPC decoding operations is reduced across all SNR ranges. The decoding convergence speed is not affected. Hardware architecture and FPGA implementation for IEEE 802.16e LDPC codes are presented. Copyright © 2011 John Wiley & Sons, Ltd.
Abdichtungen in und unter Mauerwerk
Authors: Oswald Rainer
Published: September 2011

Abdichtungen in und unter Mauerwerk – darunter sind Querschnittsabdichtungen bei tragenden und nichttragenden Wänden und Fußpunktabdichtungen in Verblendschalen zu verstehen – machen in Leistungsverzeichnissen und Abrechnungen nur kleine Positionen aus. Geben solche Abdichtungen zu Mangelstreitigkeiten Anlass oder sind sie gar fehlerhaft ausgeführt und die Ursache von Schäden, so können sich diese “kleinen Positionen“ zu sehr großen Schadensposten auswachsen: Der Aufwand zur Korrektur oder zum Austausch von Abdichtungen in und unter Mauerwerk ist nämlich hoch.

Der vorliegende Beitrag soll auf die wesentlichen Streitpunkte klärend eingehen.
Volkswirtschaftliche Bewertung der EnEV
Authors: Böhmer Michael , Thamling Nils
Published: September 2011

Mit dem Energiekonzept aus dem Jahr 2010 hat die Bundesregierung das Ziel formuliert, die energiebedingten Treibhausgasemissionen in Deutschland bis zum Jahr 2050 um 80 % gegenüber dem Jahr 1990 zu reduzieren. Auf den Gebäudebereich entfallen heute rund 40 % des deutschen Endenergieverbrauchs und etwa ein Drittel der CO2‐Emissionen. Auf die Bereitstellung von Raumwärme und Warmwasser in Wohngebäuden entfallen rund 25 % des deutschen Endenergieverbrauchs. Der Gebäudebestand soll bis zum Jahr 2050 nahezu klimaneutral sein. Dies bedeutet eine Reduktion des Primärenergieverbrauchs bis 2050 um 80 % gegenüber 1990 und eine Verdopplung der Sanierungsrate von aktuell etwa einem Prozent auf künftig zwei Prozent (BMU, BMWi 2010).

Aus dem Energiekonzept geht weiterhin hervor, dass erhebliche Anstrengungen notwendig sein werden, um diese Ziele zu erreichen, und dass die bestehenden Instrumente hierfür nicht ausreichen werden. Die Bundesregierung plant daher umfangreiche Maßnahmen und Instrumente für den Gebäudebestand und arbeitet aktuell an deren Ausgestaltung.

Wie diese Instrumente im Detail auch aussehen mögen – für private Wohnungseigentümer und für die Wohnungswirtschaft ergeben sich große Herausforderungen aus den Zielsetzungen des Energiekonzepts. Dazu sind einige grundlegende Fragen zu den ökonomischen Auswirkungen von Energieeffizienzanforderungen im Gebäudebereich einerseits und den volkswirtschaftlichen Chancen, die mit der Verfolgung dieser Ziele verbunden sind, zu klären. Im Einzelnen befasst sich dieser Beitrag mit den folgenden Fragestellungen:

– Welche einzelwirtschaftlichen Effekte hatte die Verschärfung der EnEV 2007 auf das Niveau der EnEV 2009 sowie eine mögliche Fortschreibung bei Neubauten?

– Welche volkswirtschaftlichen Effekte ergeben sich im Falle einer Steigerung der Bautätigkeit auf das im Energiekonzept angestrebte Niveau?

– Welche klimapolitischen Effekte sind damit verbunden?
MicroCT for molecular imaging: Quantitative visualization of complete three‐dimensional distributions of gene products in embryonic limbs
Authors: Metscher Brian D. , Müller Gerd B.
Published: September 2011

We present a broadly applicable procedure for whole‐mount imaging of antibody probes in embryonic tissues at microscopic resolutions based on combining a metal‐based immunodetection scheme with x‐ray microtomography (microCT). The method is generally accessible, relying on standard enzyme‐conjugated secondary antibodies and other readily available reagents, and is demonstrated here with microCT visualizations of acetylated α‐tubulin in the chick nervous system and of type II collagen in developing limbs. The tomographic images offer complete three‐dimensional representations of molecular patterns obtained with immunostaining methods at the level of organ development, with added possibilities to quantify both spatial distributions and varying densities of gene products in situ. This imaging modality bridges a crucial gap in three‐dimensional molecular imaging by combining the histological resolutions of confocal microscopy with a greater specimen size range than optical projection tomography, and thus enables a powerful new approach to long‐standing issues of skeletogenic pattern formation in vertebrate limbs. Developmental Dynamics 240:2301–2308, 2011. © 2011 Wiley‐Liss, Inc.
Respiratory functions in adolescents hospitalized for anorexia nervosa: A prospective study
Authors: Kerem Nogah C. , Averin Elvira , Riskin Arieh , Tov Nave , Srugo Isaac , Kugelman Amir
Published: September 2011

Objective:

To examine the effects of malnourishment on the respiratory system of adolescents with anorexia nervosa (AN) hospitalized for medical stabilization.

Method:

Prospective study. Study group: hospitalized adolescents with recent onset (<1 year) AN. Control group: adolescents hospitalized for other diagnoses. Excluded: participants with lung disease.

Results:

Patients' characteristics (mean ± SD) for the AN (n = 16) and the control group (n = 13) on admission were: age: 15.0 ± 1.7 vs. 15.2 ± 1.4 years, p = 0.7; body mass index (BMI): 15.5 ± 2.3 vs. 19.8 ± 2.9 kg/m2, p < 0.001; venous pH 7.34 ± 0.02 vs. 7.38 ± 0.03, p < 0.001; PCO2 53.3 ± 4.1 vs. 42.5 ± 3.1 mm Hg, p < 0.001; and HCO3 28.7 ± 2.0 vs. 25.3 ± 2.4 meq/L, p < 0.001, respectively. Therewere no significant differences in nocturnal respiratory rates, pulse‐oximetry oxygen saturations, or end‐tidal CO2. Pulmonary function tests (PFTs) in adolescents with AN revealed no obstructive, restrictive, or significant pulmonary vascular disease except for lower peak expiratory flow rates (PEFRs). During hospitalization (12.3 ± 3.8 days), their weight, BMI, mean nocturnal heart rate, and respiratory rate increased significantly, while their venous PCO2 and HCO3 decreased significantly without significant changes in PFTs.

Discussion:

Adolescents with recent onset AN, admitted for medical stabilization, demonstrate hypercapnia despite normal PFTs, except for decreased PEFRs. These could result from decreased respiratory muscle strength and/or abnormal control of breathing. © 2011 by Wiley Periodicals, Inc. (Int J Eat Disord 2012)
Short‐Range Spin Order and Frustrated Magnetism in Mn2InSbO6 and Mn2ScSbO6
Authors: Ivanov Sergey , Nordblad Per , Mathieu Roland , Tellgren Roland , Politova Ekaterina , André Gilles
Published: September 2011

The complex metal oxides Mn2ASbO6 (A = In, Sc) with a corundum‐related structure A3BO6 were prepared as polycrystalline powders by a solid‐state reaction route. Their crystal structure and magnetic properties were investigated by using a combination of X‐ray and neutron powder diffraction, electron microscopy, calorimetric, and magnetic measurements. At room temperature, these compounds adopt a trigonal structure, space group R$\bar {3}$, with a = 8.9313(1) Å, c = 10.7071(2) Å (for In) and a = 8.8836(1) Å, c = 10.6168(2) Å (for Sc), which persists down to 1.6 K. The Mn and A cations were found to be randomly distributed over the A sites. The overall behavior of the magnetization of Mn2InSbO6 and that of Mn2ScSbO6 are quite similar. In spite of the relatively large amount of Mn ions on the A site, only short‐range magnetism is observed. Neutron diffraction patterns of Mn2InSbO6 showed no evidence of a long‐range magnetic ordering at 1.6 K, instead only a weak diffuse magnetic peak was observed at low temperatures. The factors governing the observed structural and magnetic properties of Mn2ASbO6 are discussed and compared with those of other Mn‐containing complex metal oxides with a corundum‐related structure. The influence of the A cation sublattice on the magnetic properties is also considered.
Anchoring of Ru–Pt and Ru–Au Clusters onto a Phosphane‐Functionalized Carbon Support
Authors: Willocq Christopher , Vidick Deborah , Tinant Bernard , Delcorte Arnaud , Bertrand Patrick , Devillers Michel , Hermans Sophie
Published: September 2011

Two mixed‐metal clusters, [Ru5PtC(CO)14(COD)] (1) and [Ru6Au2C(CO)16(PPh3)2] (2), were anchored onto a prefunctionalized active carbon support (C) with chelating phosphane groups on its surface. These clusters were also deposited onto the unmodified support (CSX+) for comparison. The incorporation of 1 and 2 on both supports was studied by a combination of SIMS and XPS. When the clusters were anchored onto the functionalized carbon support, SIMS spectra displayed characteristic patterns that were different from those obtained in the case of their deposition on the unmodified support. In the latter case, spectra corresponded to the results obtained with pure unsupported clusters. XPS analyses of the supported species seemed to indicate that the stoichiometry of the clusters was retained after anchoring and that their dispersion was better on C than on CSX+. This indicates that the phosphanes act as anchors for noble metal compounds through a ligand exchange mechanism. The supported samples were then thermally activated and characterized by SIMS, XPS, TEM/EDXS and XRD. Analyses by SIMS showed that the cluster ligand shell was removed during thermal treatment. XPS measurements indicated that the composition of the supported particles corresponded to that of the starting clusters and that the dispersion remained higher in the case of C. Well‐dispersed bimetallic‐supported nanoparticles (1–2 nm) were obtained when cluster 1 was used as the precursor, whereas anchoring of cluster 2 resulted in its fragmentation leading to supported nanoparticles of variable stoichiometries. Reactions with soluble model molecules were carried out to prove the chemical bonding of 1. Crystallization of the new cluster [Ru5PtC(CO)14{(PPh2CH2)2NC3H7}] confirmed the chemical bonding of cluster 1 onto the C support through a ligand exchange mechanism involving COD.
One‐Pot Synthesis of Core‐Shell Silver‐Gold Nanoparticle Solutions and Their Interaction with Methylene Blue Dye
Authors: Uppal Madeeha A. , Ewing Michael B. , Parkin Ivan P.
Published: September 2011

A one‐pot modified Turkevich synthesis was used to synthesise a range of colloids from pure Ag, through Ag/Au core‐shell mixtures to pure Au by the thermal co‐addition of trisodium citrate to auric acid and silver nitrate mixtures. The colloids were analysed by means of XRD and wide‐beam energy dispersive X‐ray (EDX) analysis. The UV/Vis spectroscopy showed a non‐linear variation in the surface plasmon resonance band with the Au/Ag ratio, consistent with core‐shell formation. High resolution transmission electron microscopy (HRTEM) imaging, in conjunction with thin‐beam EDX line analysis, confirmed the presence of predominantly Ag cores and Au exteriors in the Au/Ag mixture. The argon ion sputtering with X‐ray photoelectron spectroscopy (XPS) measurements of the particles also indicated a Ag‐Au core‐shell formation. Ag0, Au0 and significant levels of AuI states were observed, which correlate with a Ag‐Au core‐shell model where the gold shell becomes partially oxidised at the surface. The subsequent titration of the colloids with methylene blue (MB) dye showed strong positive increases in the extinction coefficient at the absorption maximum. At the optimum levels of dye addition, a linear relationship was found between the average nanoparticle size and the number of dye solvation shells. The pure Au and Ag colloids showed the greatest propensity for an increase in the extinction coefficient of MB due to an enhanced transfer of the surface plasmons to the localised dye molecules and demonstrated the potential for increased functionality as light‐activated agents in the lethal photosensitisation of bacteria.
Coordination and Catalytic Activity of Ruthenium Complexes Containing Tridentate P,N,O Ligands
Authors: Lee Chun‐Chin , Chu Wan‐Yi , Liu Yi‐Hong , Peng Shie‐Ming , Liu Shiuh‐Tzung
Published: September 2011

The coordination chemistry of RuII ions with [2‐(diphenylphosphanyl)‐N‐(o‐hydroxybenzylidene)]aniline (PNO‐H) and the methylated analogue PNO‐Me have been studied. Thus, [(PNO)RuCl(dmso)2] (1), [(PNO)2Ru] (2), [(PNO)RuCl(PPh3)] (3) and [(PNO)RuCl(CO)2] (4) were synthesized by reactions of various RuII precursors with PNO‐H. Treatment of PNO‐Me with [RuCl2(dmso)4] resulted in in the formation of [P,N‐(PNO‐Me)Ru(dmso)2Cl2] (5). However, complexation of PNO‐Me with [RuCl2(CO)3(THF)] (THF = tetrahydrofuran) provided a mixture of [P,N‐(PNO‐Me)Ru(CO)2Cl2] (6) and 4 because O‐demethylation took place during the reaction. All of the RuII complexes have been characterized by elemental analysis and spectroscopic techniques, as well as X‐ray crystal structural analysis for 2, 4 and 6. The ruthenium complexes investigated in this work, except 2, are good precatalysts for the reductive amination of amine with alcohols, and 4 appears to be the best. Moreover, 4 can catalyze the direct amination of nitrobenzene with benzyl alcohol to the corresponding secondary amine.
Beneficial compaction of spinal cord lesion by migrating astrocytes through glycogen synthase kinase‐3 inhibition
Authors: Renault‐Mihara Francois , Katoh Hiroyuki , Ikegami Takeshi , Iwanami Akio , Mukaino Masahiko , Yasuda Akimasa , Nori Satoshi , Mabuchi Yo , Tada Hirobumi , Shibata Shinsuke , Saito Ken , Matsushita Masayuki , Kaibuchi Kozo , Okada Seiji , Toyama Yoshiaki , Nakamura Masaya , Okano Hideyuki
Published: September 2011

The migratory response of astrocytes is essential for restricting inflammation and preserving tissue function after spinal cord injury (SCI), but the mechanisms involved are poorly understood. Here, we observed stimulation of in vitro astrocyte migration by the new potent glycogen synthase kinase‐3 (GSK‐3) inhibitor Ro3303544 and investigated the effect of Ro3303544 administration for 5 days following SCI in mice. This treatment resulted in accelerated migration of reactive astrocytes to sequester inflammatory cells that spared myelinated fibres and significantly promoted functional recovery. Moreover, the decreased extent of chondroitin sulphate proteoglycans and collagen IV demonstrated that scarring was reduced in Ro3303544‐treated mice. A variety of in vitro and in vivo experiments further suggested that GSK‐3 inhibition stimulated astrocyte migration by decreasing adhesive activity via reduced surface expression of β1‐integrin. Our results reveal a novel benefit of GSK‐3 inhibition for SCI and suggest that the stimulation of astrocyte migration is a feasible therapeutic strategy for traumatic injury in the central nervous system.
Local variations of solifluction activity and environment in the Abisko Mountains, Northern Sweden
Authors: Ridefelt Hanna , Boelhouwers Jan , Etzelmüller Bernd
Published: September 2011

Seven sites within the mountain region of Abisko, northern Sweden, were selected for measurement of solifluction movement rates and correlation with the local environmental factors. Grids with sizes from 20 m × 30 m to 50 m × 100 m included both solifluction landforms and adjacent ground. Positions of movement markers and the terrain were recorded and the grid areas were digitally reconstructed. This allowed topography, vegetation and soil texture (fraction of fine material) surfaces to be interpolated and used together with data on soil moisture in statistical analyses. Significant correlations differ from site to site indicating that environmental factors have varying importance and inter‐relations depending on the local setting. Geomorphic work was also assessed within the grids. The results indicate measurable geomorphic work where no landforms are present. These areas may make larger contributions to sediment displacement than where solifluction landforms exist. Solifluction is an important denudational agent in the region and has its greatest impact on landscape development in the western part of the region. Copyright © 2011 John Wiley & Sons, Ltd.
Dynamic motility of microglia: Purinergic modulation of microglial movement in the normal and pathological brain
Authors: Ohsawa Keiko , Kohsaka Shinichi
Published: September 2011

Microglia have highly branched and motile cell processes and constantly screen the brain parenchyma under physiological conditions. In response to pathological stimuli, microglia exhibit morphological changes and migrate toward the lesioned site, where they play important roles in inflammatory reactions and neuronal damage. Within minutes of brain damage, microglial processes rapidly extend toward the injured site. The chemoattractive response is triggered by ATP released at the site of injury and the consequent activation of the purinergic receptor P2Y12R on microglia. In addition to the purinergic signals, various neuronal signaling molecules actively and negatively control microglial motility, which is important for regulating the functional activation of microglia in response to pathology. In this review, we focus on the dynamic motion of microglia and describe several key molecules regulating microglial motility in normal and pathological brain tissues. © 2011 Wiley‐Liss, Inc.