bluuebunny/crossref_metadata_2025_split huggingface dataset:
Der Beitrag der Grünen Gentechnik
Authors: Sonnewald Uwe 
Published: April 2012

AbstractEin globaler Klimawandel, abnehmende Reserven an fossilen Rohstoffen, eine wachsende Weltbevölkerung sowie eine älter werdende Gesellschaft sind Herausforderungen, denen sich eine moderne Pflanzenzüchtung stellen muss. Zuchtziele werden deshalb zunehmend auch Fragen zur Produktion nachwachsender Rohstoffe und zur Sicherung ausreichender und qualitativ hochwertiger Lebens‐ und Futtermmittel sein. Insbesondere birgt ein weltweit steigender Energiebedarf die Gefahr, dass immer mehr landwirtschaftliche Nutzflächen für industrielle Anwendungen und nicht für die Lebensmittelproduktion verwendet werden. Deshalb ist die Züchtung von Hochleistungspflanzen zur Stoffproduktion von großer Bedeutung. Zur Optimierung der Produktion bestimmter Inhaltstoffe sind ein fundiertes molekulares und biochemisches Wissen der zugrunde liegenden Stoffwechselwege und die Verfügbarkeit von Technologien zur Übertragung dieser Erkenntnisse auf Nutzpflanzen erforderlich. Die Pflanzenbiotechnologie kann hierbei eine wesentliche Technologie darstellen, die sowohl bei der Entschlüsselung molekularer Zusammenhänge als auch bei der züchterischen Umsetzung von Bedeutung ist.
Zur Visualisierung von Evo‐Devo vor 100 Jahren
Authors: Markert Michael , Hoßfeld Uwe , Levit Georg S. , Olsson Lennart 
Published: April 2012

AbstractAnlässlich einer noch bis 10. Juni 2012 stattfindenden Ausstellung “Tierische Bilder. Wandtafeln und Modelle mit Geschichte. Zeitgenössische Aquarelle” in der Galerie Stadtspeicher in Jena wird auch das “Modell eines menschlichen Embryos am Ende der 4. Woche (Embryo His Br3, nat. Größe 9,6 mm)” in restauriertem Zustand und der ursprünglichen Farbgebung gezeigt. Es gilt als eine der ersten didaktischen Visualisierungen der Entwicklungsbiologie (heute Evo‐Devo) in der deutschen Hochschullandschaft.
Drying Kinetics of Silica Gel: Statistical Discrimination Using Nonlinearity Measures
Authors: Souza G. F. M. V. , Miranda R. F. , Arruda E. B. , Mendoza O. S. H. , Barrozo M. A. S. 
Published: April 2012

AbstractThe objective of the present work was to analyze the drying kinetics of silica gel based on an experimental study performed in a thin‐layer dryer and a statistical discrimination of the main drying kinetic equations. Most semi‐empirical drying kinetics equations presented in the literature are nonlinear; thus, care should be taken when estimating parameters, since in some situations the estimators may not be appropriate. There are procedures available to validate the statistical properties of the least squares estimators of nonlinear models. In this study, five semi‐empirical drying kinetics equations were discriminated using measures of curvature and bias. The results showed that the Overhults equation is the best one to describe the drying kinetics of silica gel.
Halogenated Benzene Cation Radicals
Authors: Molski Matthias J. , Mollenhauer Doreen , Gohr Sebastian , Paulus Beate , Khanfar Monther A. , Shorafa Hashem , Strauss Steven H. , Seppelt Konrad 
Published: April 2012

AbstractThe halogenated benzenes C6HF5, 2,4,6‐C6H3F3, 2,3,5,6‐C6H2F4, C6F6, C6Cl6, C6Br6, and C6I6 were converted into their corresponding cation radicals by using various strong oxidants. The cation‐radical salts were isolated and characterized by electron paramagnetic resonance (EPR) spectroscopy and by single‐crystal X‐ray diffraction. The thermal stability of the cation radicals increased with decreasing hydrogen content. As expected, the cation radicals [C6HF5]+ and 2,3,5,6‐[C6H2F4]+ had structures with the same geometry as C6HF5 and 2,3,5,6‐[C6H2F4]. In contrast, the cation radicals [C6F6]+, [C6Cl6]+, and possibly also [C6Br6]+ exhibited Jahn–Teller‐distorted geometries in the crystalline state. In the case of C6F6+Sb2F11−, two low‐symmetry geometries were observed in the same crystal. Interestingly, the structures of the cation radicals 2,4,6‐[C6H3F3]+ and C6I6+ did not exhibit Jahn–Teller distortions. DFT calculations showed that the explanation for the lack of distortion of these cations from the D3h or D6h symmetry of the neutral benzene precursor was different for 2,4,6‐[C6H3F3]+ than for [C6I6]+.
How Is Methane Formed and Oxidized Reversibly When Catalyzed by Ni‐Containing Methyl‐Coenzyme M Reductase?
Authors: Chen Shi‐Lu , Blomberg Margareta R. A. , Siegbahn Per E. M. 
Published: April 2012

AbstractNi‐containing methyl‐coenzyme M reductase (MCR) is capable of catalyzing methane formation and has recently been observed to also be able to catalyze the reverse reaction, the anaerobic oxidation of methane. The forward reaction has been extensively studied theoretically before and was found to consist of two steps. The first step is rate‐limiting and the second step was therefore treated at a lower level. For an accurate treatment of the reverse reaction, both steps have to be studied at the same level. In the present paper, the mechanisms for the reversible formation and oxidation of methane catalyzed by MCR have been investigated using hybrid density functional theory with recent developments, in particular including dispersion effects. An active‐site model was constructed based on the X‐ray crystal structure. The calculations indicate that the MCR reaction is indeed reversible and proceeds via a methyl radical and a Ni‐S(CoM) intermediate with reasonable reaction barriers in both directions. In a competing mechanism, the formation of the crucial Ni‐methyl intermediate, was found to be strongly endergonic by over 20 kcal mol−1 (including a barrier) with dispersion and entropy effects considered, and thus would not be reachable in a reasonable time under natural conditions.
More Efficiency in Plant Engineering with Digital Engineering
Authors: Schenk Michael 
Published: April 2012

AbstractNeue Strategien und Konzepte sind gefragt, um die Effizienz von Anlagen über den gesamten Lebenszyklus zu steigern. Der Ansatz des Fraunhofer IFF zielt dabei auf die durchgängige Nutzung digitaler Methoden und Werkzeuge über den gesamten Produktentstehungs‐ und Produktionsprozess ab. Mit dem Lösungsansatz des Digital Engineerings kann die Vision der Virtuellen Anlage Wirklichkeit werden. Die Virtuelle Anlage integriert die Funktionen der innovativen Werkzeuge und Techniken einer Anlage mit dem Ziel, benötigte Informationen über den gesamten Anlagenlebenszyklus für alle am Produkt‐ und Produktionsprozess Beteiligten verfügbar zu machen.
Positronen‐Emissions‐Tomographie
Authors: Bauser Marcus , Lehmann Lutz 
Published: April 2012

AbstractDie Positronen‐Emissions‐Tomographie (PET) hat nach mehr als 50 Jahren seit ihrer ersten Anwendung ihren festen Platz in der medizinischen Diagnostik gefunden. Möglich geworden ist dies durch die PET‐Tracer, die immer zahlreicher und ausgefeilter erforscht und entwickelt werden und durch die Beiträge der modernen medizinischen Chemie in enger Zusammenarbeit mit Radiochemikern. Es ist mit diesen Tracern möglich, Erkrankungen wie Alzheimer deutlich vor deren Ausbruch zu diagnostizieren, bei Krebs optimale Diagnosen und Therapien zu wählen und im Falle von Herz‐Kreislauf‐Erkrankungen eine effektive Herzinfarktnachsorge zu betreiben. Die neuen dynamischen Entwicklungen bei PET‐Tracern geht einher mit einer wachsenden Zahl von PET‐Scannern in den Radiologieabteilungen der Krankenhäuser. Jedoch wird diese Technologie noch nicht als Standarddiagnostik eingesetzt, weil die PET/CT‐Geräte noch sehr teuer und daher nicht flächendeckend in den radiologischen Abteilungen der Krankenhäuser verfügbar sind. Des Weiteren wird durch die komplexe Zubereitung des PET‐Tracers ein PET/CT‐Scan immer deutlich teurer sein als ein CT‐ oder MR‐Scan. Wir glauben jedoch, dass die Vorteile einer solchen Diagnostik den höheren Preis werden kompensieren können, denn diese faszinierende Technologie basierend auf Physik, Messtechnik und ausgefeilter Radiochemie liefert uns den Einstieg in eine genauere Diagnostik und damit eine bessere und “persönlichere” Therapie.
Brustimplantate
Authors: Sokolova Viktoriya , Epple Matthias 
Published: April 2012

AbstractBrustimplantate werden in großer Zahl implantiert. Die verwendeten Materialien sind dabei bioinert, d.h. sie gehen mit dem Körper fast keine Wechselwirkungen ein. Als Material für Hülle und Füllung spielen Silikone eine wesentliche Rolle, wobei auch physiologische Kochsalzlösung als Füllung eingesetzt wird. Sofern Biomaterialien mit hoher Reinheit verwendet werden, ist der Einsatz von Brustimplantaten als medizinisch sicher anzusehen.
Rapid‐onset hypogonadism secondary to crizotinib use in men with metastatic nonsmall cell lung cancer
Authors: Weickhardt Andrew J. , Rothman Micol S. , Salian‐Mehta Smita , Kiseljak‐Vassiliades Katja , Oton Ana B. , Doebele Robert C. , Wierman Margaret E. , Camidge D. Ross 
Published: April 2012

AbstractBACKGROUND:The objective of this study was to document the differences in testosterone (T) levels between crizotinib‐treated and noncrizotinib‐treated patients with metastatic nonsmall cell lung cancer (NSCLC).METHODS:Testosterone levels were measured in 19 men with metastatic NSCLC who received crizotinib and in 19 men with metastatic NSCLC who did not receive crizotinib. Clinical characteristics of the patients were compared, and additional hormone assays were performed as appropriate. Two patients who began crizotinib and 4 patients who had dose interruptions or who stopped crizotinib therapy had serial hormone measurements, permitting the documentation of dynamic hormone changes on and off crizotinib treatment.RESULTS:Total T levels were low (<241 ng/dL) in 19 of 19 (100%) crizotinib‐treated men and in 6 of 19 men (32%) with metastatic NSCLC who did not receive crizotinib (mean T levels, 131 ng/dL and 311 ng/dL, respectively; P = .0002). Only 1 in 5 patients who had anaplastic lymphoma kinase (ALK) gene rearrangements and had not yet received crizotinib had low T. The initiation of crizotinib in 2 patients who had previously normal T levels was associated with a rapid decreases in T and in luteinizing hormone and follicle stimulating hormone levels within 14 to 21 days. Discontinuation of crizotinib led to increases back to normal T levels.CONCLUSIONS:Crizotinib therapy caused rapid suppression of T levels in men. The current results indicated that the site of action must include a central (hypothalamic or pituitary) effect, but additional direct testicular effects could not be excluded. Further work is required to assess the correlation between low T levels and crizotinib side effects as well as the exact molecular mechanism and site of drug toxicity. Cancer 2012. © 2012 American Cancer Society.
Sensory feedback alters spontaneous limb movements in newborn rats: Effects of unilateral forelimb weighting
Authors: Brumley Michele R. , Robinson Scott R. 
Published: April 2012

AbstractPerinatal mammals show spontaneous movements that often appear random and uncoordinated. Here, we examined if spontaneous limb movements are responsive to a proprioceptive manipulation by applying a weight unilaterally to a forelimb of postnatal day 0 (P0; day of birth) and P1 rats. Weights were calibrated to approximate 0%, 25%, 50%, or 100% of the average mass of a forelimb, and were attached at the wrist. P0 and P1 pups showed different levels of activity during the period of limb weighting, in response to weight removal, and during the period after weighting. Pups exposed to 50% and 100% weights showed proportionately more activity in the nonweighted forelimb during the period of weighting, suggesting a threshold for evoking proprioceptive changes. Findings suggest that newborn rats use movement‐related feedback to modulate spontaneous motor activity, and corroborate studies of human infants that have suggested a role for proprioception during early motor development. © 2012 Wiley Periodicals, Inc. Dev Psychobiol 55: 323–333, 2013
Interactive effects of past and present environments on overwintering success—a reciprocal transplant experiment
Authors: Oksanen Tuula A. , Koivula Minna , Koskela Esa , Mappes Tapio , Soulsbury Carl D. 
Published: April 2012

AbstractLife‐history traits are influenced by environmental factors throughout the lifespan of an individual. The relative importance of past versus present environment on individual fitness, therefore, is a relevant question in populations that face the challenge of temporally varying environment. We studied the interacting effects of past and present density on body mass, condition, and survival in enclosure populations of the bank vole (Myodes glareolus) using a reciprocal transplant design. In connection with the cyclic dynamics of natural vole populations, our hypothesis was that individuals born in low‐density enclosures would do better overwintering in low‐density enclosures than in high‐density enclosures and vice versa. Our results show that the effect of summer (past) density was strong especially on survival and body mass. The response of body mass to summer density was negative in both winter (present) density groups, whereas the response of survival probability was nonlinear and differed between the winter density groups. In particular, our data show a trend for higher overwintering success of individuals originating from the lowest summer densities in low winter density and vice versa. We therefore conclude that the capacity of individuals to respond to a change in density was constrained by the delayed density‐dependent effects of environment experienced in the past. These effects have the potential to contribute to vole population dynamics. Possible mechanisms mediating the effects of past environment into present performance include both intrinsic and environmental factors.
Synthesis and Solid‐State Investigations of Oligo‐Phenylene–Ethynylene Structures with Halide End‐Groups
Authors: Jenny Nicolas M. , Wang Hong , Neuburger Markus , Fuchs Harald , Chi Lifeng , Mayor Marcel 
Published: April 2012

AbstractIn the field of material science functionalization of substrate surfaces (e.g. metal, graphite) with organic molecules is of increasing interest. Desirable targets are molecules with functional groups providing for two‐dimensional assembly and three‐dimensional crystal growth. We have synthesized a series of halogen‐end‐capped oligo‐phenylene‐ethynylenes (OPEs) to study the interactions at the solid/liquid interface and in crystal structures. Organohalides can be involved in a wide variety of intermolecular interactions such as C–X···H, C–X···X–C and C–X···π‐orbitals. The range of halogen‐based interactions and the diversity of intermolecular forces along different crystal axes makes the investigation of such structures particular interesting and challenging. Here we probe the interplay of halide end‐groups and the backbone of an OPE to investigate the intermolecular interactions in both solution depositions (2D) and X‐ray crystal structures (3D). The STM images and the crystal structures of each OPE reveal striking packing similarities. For each molecule, a plane in the crystal structure with an arrangement of molecules resembling its two‐dimensional packing on a flat surface was found. These results support the hypothesis of sheet‐by‐sheet crystal growth and suggest that flat surfaces would be ideal interfaces to promote crystal growth for halide‐end‐capped OPEs.
A Nitro Sugar‐Mediated Stereocontrolled Synthesis of β2‐Amino Acids: Synthesis of a Polyhydroxylated trans‐2‐Amino­cyclohexanecarboxylic Acid
Authors: Otero José M. , Fernández Fernando , Estévez Juan C. , Nash Robert , Estévez Ramón J. 
Published: April 2012

AbstractThe first stereocontrolled nitro sugar‐mediated synthesis of polyhydroxylated β‐amino acids and their incorporation into peptides is described. The key steps of this approach are a Michael addition of the lithium salt of tris(phenylthio)methane (a carboxyl synthetic equivalent) to sugar nitro olefins, and the reduction of the nitro group to an amino group. Specifically, two glyceraldehyde‐based β‐amino acids and a polyhydroxylated cyclohexyl β‐amino acid were prepared. The latter, which could act as a water‐soluble mimic of the proline‐glycine δ‐turn, was easily transformed into the corresponding 5‐amino‐6‐(hydroxymethyl)cyclohexane‐1,2,3,4‐tetraol, a novel amino‐carbasugar. However, this did not show significant glycosidase inhibiting properties.
Electrochemical Behavior and Amperometric Detection of 4‐Chlorophenol on Nano‐Au Thin Films Modified Glassy Carbon Electrode
Authors: Qiu Cuicui , Dong Xiaoqiang , Ma Houyi , Hou Shifeng , Yang Jie 
Published: April 2012

AbstractAn amperometric sensor based on nano‐Au thin films was fabricated, by means of which a fast response to 4‐chlorophenol (4‐CP) can be achieved in the range of mM concentrations. The nanostructured Au thin film was prepared on glassy carbon electrodes by a template‐free, double‐potential step electrodeposition technique. Its structural feature can be controlled well by adjusting the deposition time. The amperometric detection of 4‐CP was performed at +0.85 V with a linear detection range from 0.2 to 4.8 mM and a detection limit of 0.11 mM (S/N=3). Besides, the effect of concentrations on the electrochemical behavior of 4‐CP on the Au thin film was investigated by linear sweep voltammetry, differential pulse voltammetry and electrochemical impedance spectroscopy.
Fabrication of Acid Violet 34/Nickel Hydroxide Ultrathin Film and Its Electrocatalytic Performance for Glucose
Authors: Chen Li , Kong Xianggui , Yan Dongpeng , Wei Min , Duan Xue 
Published: April 2012

AbstractThis article reports the fabrication of Acid Violet 34 (AV34)/nickel hydroxide nanosheets ultrathin film on the glassy carbon electrode (GCE) via the electrostatic layer‐by‐layer (LBL) technique, and its electrocatalytic oxidation for glucose was demonstrated. UV‐vis absorption and electrochemical impedance spectra indicate the uniform deposition of the LBL film, with a continuous and smooth film surface observed by SEM and AFM. The electrochemical performance of the ultrathin film was studied by cyclic voltammetry and chronoamperometry. The (AV34/Ni(OH)2)5 ultrathin film modified electrode displays a fast direct electron transfer attributed to the Ni2+/Ni3+ redox couple as well as remarkable electrocatalytic activity towards the oxidation of glucose. The linear response was obtained in the range 0.5–13.5 mM (R=0.9994) with a low detection limit (14 µM), high sensitivity (25.9 µA mM−1 cm−2), rapid response (less than 1 s) and excellent anti‐interference properties to the species including ascorbic acid (AA), uric acid (UA), acetamidophenol (AP) and structurally related sugars. Therefore, the AV34/Ni(OH)2 ultrathin film can be potentially used as a feasible electrochemical sensor for the determination of glucose.
P‐selectin genotype is associated with the development of cancer cachexia
Authors: Tan Benjamin H. L. , Fladvad Torill , Braun Theodore P. , Vigano Antonio , Strasser Florian , Deans D. A. Christopher , Skipworth Richard J. E. , Solheim Tora S. , Damaraju Sambasivarao , Ross James A. , Kaasa Stein , Marks Daniel L. , Baracos Vickie E. , Skorpen Frank , Fearon Kenneth C. H. ,   European Palliative Care Research Collaborative
Published: April 2012

AbstractThe variable predisposition to cachexia may, in part, be due to the interaction of host genotype. We analyzed 129 single nucleotide polymorphisms (SNPs) in 80 genes for association with cachexia based on degree of weight loss (>5, >10, >15%) as well as weight loss in the presence of systemic inflammation (C‐reactive protein, >10 mg/l). 775 cancer patients were studied with a validation association study performed on an independently recruited cohort (n = 101) of cancer patients. The C allele (minor allele frequency 10.7%) of the rs6136 (SELP) SNP was found to be associated with weight loss >10% both in the discovery study (odds ratio (OR) 0.52; 95% confidence intervals (CI), 0.29–0.93; p = 0.026) and the validation study (OR 0.09, 95% CI 0.01–0.98, p = 0.035). In separate studies, induction of muscle atrophy gene expression was investigated using qPCR following either tumour‐induced cachexia in rats or intra‐peritoneal injection of lipopolysaccharide in mice. P‐selectin was found to be significantly upregulated in muscle in both models. Identification of P‐selectin as relevant in both animal models and in cachectic cancer patients supports this as a risk factor/potential mediator in cachexia.See accompanying article http://dx.doi.org/10.1002/emmm.201200232
Microstructure of Gas Diffusion Layers for PEM Fuel Cells
Authors: Parikh N. , Allen J. S. , Yassar R. S. 
Published: April 2012

AbstractThe gas diffusion layer (GDL) is a critical component of a proton exchange membrane fuel cell, and can play a key role in fuel cell performance. In order to design reliable and durable fuel cells, knowledge of the GDL microstructure is necessary. Currently, characterization of GDLs is generally based on porosity measurements to obtain a pore size distribution. However, the pore size distribution in GDLs may not be the only factor that affects the fuel cell performance. Additional microstructural characterization of GDLs manufactured by three different vendors (Toray, SGL, and Freudenberg) has been investigated. In addition to the pore size distribution, other statistical information of GDL microstructure including size, shape, orientation, and distribution of pores have been characterized and compared. Among these GDLs, the Freudenberg sample was found to have the smallest pore size and orientation analysis indicated that the pores were randomly distributed. Pore roundness was the lowest and pore clustering was highest in Toray sample. The effect of threshold setting on pore size data was also studied and found to have negligible influence on the calculated distributions. The microstructures of the GDLs were reconstructed in three‐dimension using computer simulations and good agreement with the two‐dimensional image analysis data was observed. The present work opens new opportunities for experimentalists and modelers in the area of fuel cell research to take into account the statistical characteristics of GDL microstructure.
Glial glutamate transport modulates dendritic spine head protrusions in the hippocampus
Authors: Verbich David , Prenosil George A. , Chang Philip K.‐Y. , Murai Keith K. , McKinney R. Anne 
Published: April 2012

AbstractAccumulating evidence supports the idea that synapses are tripartite, whereby perisynaptic astrocytes modulate both pre‐ and postsynaptic function. Although some of these features have been uncovered by using electrophysiological methods, less is known about the structural interplay between synapses and glial processes. Here, we investigated how astrocytes govern the plasticity of individual hippocampal dendritic spines. Recently, we uncovered that a subgroup of innervated dendritic spines is able to undergo remodeling by extending spine head protrusions (SHPs) toward neighboring functional presynaptic boutons, resulting in new synapses. Although glutamate serves as a trigger, how this behavior is regulated is unknown. As astrocytes control extracellular glutamate levels through their high‐affinity uptake transporters, together with their privileged access to synapses, we investigated a role for astrocytes in SHP formation. Using time‐lapse confocal microscopy, we found that the volume overlap between spines and astrocytic processes decreased during the formation of SHPs. Focal application of glutamate also reduced spine‐astrocyte overlap and induced SHPs. Importantly, SHP formation was prevented by blocking glial glutamate transporters, suggesting that glial control of extracellular glutamate is important for SHP‐mediated plasticity of spines. Hence, the dynamic changes of both spines and astrocytes can rapidly modify synaptic connectivity. © 2012 Wiley Periodicals, Inc.