bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ab Initio Simulation of Complex Dielectric Function for Dense Aluminum Plasma
Authors: Povarnitsyn M. E. , Knyazev D. V. , Levashov P. R. 
Published: February 2012

AbstractWe present calculations of frequency‐dependent complex dielectric function of dense aluminum plasma by quantum molecular dynamics method for temperatures up to 20 kK. Analysis shows that the dependencies for real and imaginary parts can be interpolated by the Drude formula with two effective parameters: the mean charge of ions and the effective frequency of collisions. The rise of these parameters with temperature deviates from simple theoretical predictions (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
NiO Thin Films Synthesized by Atomic Layer Deposition using Ni(dmamb)2 and Ozone as Precursors
Authors: Antony Premkumar Peter , Toeller Michael , Adelmann Christoph , Meersschaut Johan , Franquet Alexis , Richard Olivier , Tielens Hilde , Brijs Bert , Moussa Alain , Conard Thierry , Bender Hugo , Schaekers Marc , Kittl Jorge A. , Jurczak Malgorzata , Van Elshocht Sven 
Published: March 2012

AbstractNiO thin films are deposited by atomic layer deposition (ALD) from the Ni(dmamb)2 (dmamb = 1‐dimethylamino‐2‐methyl‐2‐butanolate) precursor using O3 as the oxidizer. The films are analyzed for wafer uniformity, structure, composition, morphology, microstructure, and homogeneity. The Ni(dmamb)2 half‐cycle shows an initial rapid partial saturation followed by slower further adsorption. By contrast, the O3 half‐cycle shows good saturation behavior. In the studied deposition temperature range for ALD, the films are polycrystalline with negligible amounts of carbon in the films. Furthermore, the films are homogeneous in thickness and composition, demonstrating that high‐quality NiO films can be deposited by ALD from Ni(dmamb)2.
Groundwater‐dependent distribution of vegetation in Hailiutu River catchment, a semi‐arid region in China
Authors: Lv Jingjing , Wang Xu‐Sheng , Zhou Yangxiao , Qian Kaizhu , Wan Li , Eamus Derek , Tao Zhengping 
Published: February 2012

ABSTRACTIn arid and semi‐arid regions, groundwater availability is one of the controls on vegetation distribution. This groundwater‐dependent distribution of vegetation has been particularly observed in the Hailiutu River catchment, a semi‐arid region in North China. We used remote sensing images of vegetation index (normalized difference vegetation index, NDVI) and field data of depth to water table (DWT) to assess the response of vegetation distribution on increase of DWT at the regional scale. The frequency distribution curves of NDVI with respect to different DWT were obtained. The statistical distributions of NDVI values at different DWT intervals indicate that higher vegetation coverage and more plant diversity exist at places of shallow groundwater. Both the mean and the standard deviation of NDVI values decrease with the increase of groundwater depth when DWT is less than 10 m. Beyond that depth, a low level of vegetation coverage and diversity is maintained. Comparisons of different sub‐areas within the region with different dominant species showed that the NDVI of shrubs is sensitive to DWT. In contrast, NDVI of herbs is not significantly influenced by DWT. The relationship between NDVI and groundwater depth in farmlands could not be reliably determined because of disturbance by human activities. We conclude that application of this methodology may significantly improve our ability on sustainable management of land and groundwater resources. Copyright © 2012 John Wiley & Sons, Ltd.
Astrocyte calcium signaling and epilepsy
Authors: Carmignoto Giorgio , Haydon Philip G. 
Published: March 2012

AbstractStudies performed over the last decade, in both animal models and human epilepsy, support the view that a defective K+ buffering due to an altered expression of K+ and aquaporin channels in astrocytes represents a possible causative factor of the pathological neuronal hyperexcitability in the epileptic brain. More recent studies, however, reappraised the role of neurons in epileptogenesis and suggested that Ca2+‐dependent gliotransmission directly contributes to the excessive neuronal synchronization that predisposes the brain network to seizures. Significant support for this view comes from the finding that astrocytes from hyperexcitable networks respond to neuronal signals with massive Ca2+ elevations and generate a recurrent excitatory loop with neurons that has the potential to promote a focal seizure. The specific aim of this review is on the one hand, to provide an overview of the experimental findings that hinted at a direct role of Ca2+‐dependent gliotransmission in the generation of seizure‐like discharges in models of focal epilepsy; and on the other hand, to emphasize the importance of developing new experimental tools that could help us to understand the amazing complexity of neuron‐astrocyte partnership in brain disorders. © 2012 Wiley Periodicals, Inc.
Who worries most? Worry prevalence and patterns across the lifespan
Authors: Gonçalves Daniela C. , Byrne Gerard J. 
Published: February 2012

ObjectiveTo examine the age‐related worry patterns in a population‐based sample of self‐reported worriers.MethodsThe National Survey of Mental Health and Well‐Being is a multistage stratified epidemiologic survey of mental health conducted in Australia in 2007. Participants were surveyed using the Composite International Diagnostic Interview. All participants who reported a period of pervasive worry were included in this study (N = 3735, 16–85 years of age, 61% female).ResultsCompared with younger adults (16–29 years of age; N = 860), older adults (65–85 years of age; N = 639) reported fewer worries [odds ratio (OR) = 0.36, p < 0.01] and a lower likelihood of worrying about interpersonal relations (OR = 0.66, p < 0.01), health (OR = 0.65, p < 0.05), work (OR = 0.39, p < 0.01), and miscellaneous topics (OR = 0.57, p < 0.01), but a higher likelihood of worrying about the health and welfare of loved ones (OR = 2.46, p < 0.01) after adjusting for socio‐demographic and clinical factors. Similar patterns were seen in older persons with and without a lifetime history of generalized anxiety disorder as diagnosed by the Diagnostic and Statistical Manual of Mental Disorders.ConclusionsThe findings indicated an overall decrease in worry count with advancing age, as well as a developmental distribution of worry content, and a quantitative but not qualitative distinction between normal and pathological worriers. Overall, these findings might contribute to the understanding of worry processes and the phenomenology of generalized anxiety disorder in older cohorts. Copyright © 2012 John Wiley & Sons, Ltd.
The effect of d‐methamphetamine on simulated driving performance
Authors: Silber Beata Y. , Croft Rodney J. , Downey Luke A. , Papafotiou Katherine , Camfield David A. , Stough Con 
Published: March 2012

ObjectivesMethamphetamine is considered to be one of the most popularly abused drugs by drivers; however, its exact effect on driving and driving behaviour has yet to be thoroughly investigated. This being despite methamphetamine's increased prevalence in injured and deceased drivers.MethodsTwenty healthy recreational illicit stimulant users (10 male and 10 female), aged between 21 and 32 years (mean = 25.4 years, SD = 3.3 years) attended two testing sessions involving oral consumption of 0.42 mg/kg d‐methamphetamine or a matching placebo. The drug administration was counter‐balanced, double‐blind, and medically supervised. At each session driving, performance was assessed 2.5 h post drug administration.Resultsd‐methamphetamine (0.42 mg/kg) did not significantly impair overall simulated driving performance 2.5 h post drug administration. At the individual driving variable level, participants in the d‐methamphetamine condition were observed to be driving slower when an emergency situation occurred (T = 44, p < 0.05), but interestingly, participants in both conditions recorded average speeds in excess of the speed limit (100 km/h) when the emergency situations occurred. The d‐methamphetamine condition did also produce four times more infringements where participants did not stop at red traffic light in comparison to the placebo, but this effect was only evident at a trend level (T = 7, p = 0.11).ConclusionsThe findings presented herein suggest that d‐methamphetamine administered at the levels supplied did not impair driving performance in a manner consistent with epidemiological evidence. Further research is certainly required to elucidate the effects of various doses of methamphetamine, alone and in combination with other legal and illicit substances. Copyright © 2012 John Wiley & Sons, Ltd.
Immune system inflammation in cocaine dependent individuals: implications for medications development
Authors: Fox Helen C. , D'Sa Carrol , Kimmerling Anne , Siedlarz Kristen M. , Tuit Keri L. , Stowe Raymond , Sinha Rajita 
Published: March 2012

ObjectivesCocaine dependence is a chronic stress state. Furthermore, both stress and substance abuse have robust and reciprocal effects on immune system cytokines, which are known to be powerful modulators of mood. We therefore examine basal and provoked changes in peripheral cytokines in cocaine dependent individuals to better understand their role in the negative reinforcing effects of cocaine.MethodsTwenty‐eight (16 F/12 M) treatment‐seeking cocaine dependent individuals and 27 (14 F/13 M) social drinkers were exposed to three 5‐min guided imagery conditions (stress, drug cue, relaxing) presented randomly across consecutive days. Measures of salivary cortisol, tumor necrosis factor alpha (TNFα), interleukin‐10 (IL‐10), and interleukin‐1 receptor antagonist (IL‐1ra) were collected at baseline and various post‐imagery time‐points.ResultsCocaine abusers demonstrated decreased basal IL‐10 compared with social drinkers. They also showed significant elevations in pro‐inflammatory TNFα when exposed to stress compared with when they were exposed to relaxing imagery. This was not observed in the social drinkers. Conversely, social drinkers demonstrated increases in the anti‐inflammatory markers, IL‐10 and IL‐1ra, following exposure to cue, which were not seen in the dependent individuals.ConclusionsCocaine dependent individuals demonstrate an elevated inflammatory state both at baseline and following exposure to the stress imagery condition. Cytokines may reflect potentially novel biomarkers in addicted populations for treatment development. Copyright © 2012 John Wiley & Sons, Ltd.
Controlled drug delivery through a novel PEG hydrogel encapsulated silica aerogel system
Authors: Giray Seda , Bal Tuğba , Kartal Ayse M. , Kızılel Seda , Erkey* Can 
Published: February 2012

AbstractA novel composite material consisting of a silica aerogel core coated by a poly(ethylene) glycol (PEG) hydrogel was developed. The potential of this novel composite as a drug delivery system was tested with ketoprofen as a model drug due to its solubility in supercritical carbon dioxide. The results indicated that both drug loading capacity and drug release profiles could be tuned by changing hydrophobicity of aerogels, and that drug loading capacity increased with decreased hydrophobicity, while slower release rates were achieved with increased hydrophobicity. Furthermore, higher concentration of PEG diacrylate in the prepolymer solution of the hydrogel coating delayed the release of the drug which can be attributed to the lower permeability at higher PEG diacrylate concentrations. The novel composite developed in this study can be easily implemented to achieve the controlled delivery of various drugs and/or proteins for specific applications. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A:, 2012.
Preparation of a biomimetic nanocomposite scaffold for bone tissue engineering via mineralization of gelatin hydrogel and study of mineral transformation in simulated body fluid
Authors: Azami Mahmoud , Moosavifar Mir Javad , Baheiraei Nafiseh , Moztarzadeh Fathollah , Ai Jafar 
Published: February 2012

AbstractIn this study, double diffusion method in a physiologically relevant environment was used to prepare a biomimetic gelatin‐amorphous calcium phosphate nanocomposite scaffold. The precipitated calcium phosphate within gelatin as well as produced nanocomposite scaffolds were characterized by the commonly used bulk techniques. The results showed that nanocomposite scaffolds were porous with three‐dimensionally interconnected microstructure, pore size ranging from 150 to 350 μm. Porosity was about 82% and nanocrystalline precipitated minerals were dispersed evenly among gelatin fibers. A mineral containing amorphous calcium phosphate and brushite precipitate was formed within the gelatin matrix at 4°C. After incubation in SBF solution at 37°C for 5 days, the mineral phase was transformed to nanocrystalline hydroxyapatite. It should be noted that precursor phases inside a scaffold implanted into the body can result in biomimetic conversion of precursors to hydroxyapatite that is very similar to the bone mineral and has a profound level of biocompatibility. Thus, our results highlight the potential use of engineered biomimetic bone tissue scaffolds in the bone tissue repair process. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 2012.
Ultrasensitive detection of cellular protein interactions using bioluminescence resonance energy transfer quantum dot‐based nanoprobes
Authors: Quiñones Gabriel A. , Miller Steven C. , Bhattacharyya Sukanta , Sobek Daniel , Stephan Jean‐Philippe 
Published: March 2012

AbstractSensitive detection of protein interactions is a critical step toward understanding complex cellular processes. As an alternative to fluorescence‐based detection, Renilla reniformis luciferase conjugated to quantum dots results in self‐illuminating bioluminescence resonance energy transfer quantum dot (BRET‐Qdot) nanoprobes that emit red to near‐infrared bioluminescence light. Here, we report the development of an ultrasensitive technology based on BRET‐Qdot conjugates modified with streptavidin ([BRET‐Qdot]‐SA) to detect cell‐surface protein interactions. Transfected COS7 cells expressing human cell‐surface proteins were interrogated with a human Fc tagged protein of interest. Specific protein interactions were detected using a biotinylated anti‐human Fc region specific antibody followed by incubation with [BRET‐Qdot]‐SA. The luciferase substrate coelenterazine activated bioluminescence light emission was detected with an ultra‐fast and ‐sensitive imager. Protein interactions barely detectable by the fluorescence‐based approach were readily quantified using this technology. The results demonstrate the successful application and the flexibility of the BRET‐Qdot‐based imaging technology to the ultrasensitive investigation of cell‐surface proteins and protein–protein interactions. J. Cell. Biochem. 113: 2397–2405, 2012. © 2012 Wiley Periodicals, Inc.
The ubiquitin–proteasome pathway regulates claudin 5 degradation
Authors: Mandel Ilana , Paperna Tamar , Volkowich Anat , Merhav Maayan , Glass‐Marmor Lea , Miller Ariel 
Published: March 2012

AbstractThe tight junctions (TJs) form continuous intracellular contacts, which help create selective barriers in epithelial and endothelial cell layers. The structures created by the TJs are very dynamic and can be rapidly remodeled in response to physiological and pathological signals. Claudin 5 is a membranal TJ protein which plays a critical role in determining the permeability of endothelial barriers. We describe the regulation of claudin 5 degradation by the ubiquitin–proteasome system (UPS). Our results indicate that claudin 5 has a relatively short half‐life and can be polyubiquitinated on lysine 199. This ubiquitination appears to trigger the proteasome‐dependent degradation of claudin 5. Other mechanisms also seem to be involved in the post‐translational regulation of claudin 5, including a ubiquitin‐independent and probably indirect lysosomal‐dependent pathway. These findings provide evidence for the involvement of the UPS in the regulation of claudin 5 levels, and set the stage for further research to determine the involvement of this pathway in the modulation of the properties of TJs and cell‐layer barriers. J. Cell. Biochem. 113: 2415–2423, 2012. © 2012 Wiley Periodicals, Inc.
Elevation of cartilage AGEs does not accelerate initiation of canine experimental osteoarthritis upon mild surgical damage
Authors: Vos Petra A.J.M. , DeGroot Jeroen , Barten‐van Rijbroek Angelique D. , Zuurmond Anne‐Marie , Bijlsma Johannes W.J. , Mastbergen Simon C. , Lafeber Floris P.J.G. 
Published: March 2012

AbstractOsteoarthritis is a highly prevalent disease, age being the main risk factor. The age‐related accumulation of advanced‐glycation‐endproducts (AGEs) adversely affects the mechanical and biochemical properties of cartilage. The hypothesis that accumulation of cartilage AGEs in combination with surgically induced damage predisposes to the development of osteoarthritis was tested in vivo in a canine model. To artificially increase cartilage AGEs, right knee joints of eight dogs were repeatedly injected with ribose/threose (AGEd‐joints). Left joints with vehicle alone served as control. Subsequently, minimal surgically applied cartilage damage was induced and loading restrained as much as possible. Thirty weeks after surgery, joint tissues of all dogs were analyzed for biochemical and histological features of OA. Cartilage pentosidine levels were ∼5‐fold enhanced (p = 0.001 vs. control‐joints). On average, no statistically significant differences in joint degeneration were found between AGEd and control‐joints. Enhanced cartilage pentosidine levels did correlate with less cartilage proteoglycan release (R = −0.762 and R = −0.810 for total and newly‐formed proteoglycans, respectively; p = 0.028 and 0.015 for both). The current data support the diminished cartilage turnover, but only a tendency towards enhanced cartilage damage in AGEd articular cartilage was observed. As such, elevated AGEs do not unambiguously accelerate the development of early canine OA upon minimal surgical damage. © 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 30:1398–1404, 2012
Expression of neural and neurotrophic markers in nucleus pulposus cells isolated from degenerated intervertebral disc
Authors: Navone Stefania E. , Marfia Giovanni , Canzi Laura , Ciusani Emilio , Canazza Alessandra , Visintini Sergio , Campanella Rolando , Parati Eugenio A. 
Published: February 2012

AbstractIntervertebral disc (IVD) degeneration is a common disorder of the lower spine. Since it is caused by loss of cellularity, there is interest in the comprehension of the cellular phenotypes. This study aimed to verify if stem cells isolated from nucleus pulposus of intervertebral discs (NPs‐IVD), which may express neurogenic properties, may be implicated in IVD disease. NPs‐IVD isolated from 14 human pathological discs were cultured under mesenchymal and neural differentiation. An induction of the neural markers GFAP, NF, MAP2, O4, and a decrement of the expression of the immature neural markers β‐tubulin III, Nestin, NG2, occurred within the neural differentiation. The expression of TrkA and p75NGFR, the receptors of NGF, was not correlated with neural induction; in contrast, TrkB, the BDNF receptor, increased and was co‐expressed with acid sensing ion channel 3 (ASIC3). In the same condition, neuroinflammatory markers were over‐expressed. We confirm our hypothesis that stem cells within IVD degeneration acquire neurogenic phenotype, causing the induction of markers related to inflammatory condition. These cells could promote the enrolment of neurotrophines in adaptation to the acidic microenvironment in degenerative conditions. These data could improve our knowledge about IVD cellularity and eventually lead to the development of pharmacological therapies. © 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 30:1470–1477, 2012
Reversible and irreversible denaturation processes in globular proteins: from collective to molecular spectroscopic analysis
Authors: Sassi Paola , Perticaroli Stefania , Comez Lucia , Lupi Laura , Paolantoni Marco , Fioretto Daniele , Morresi Assunta 
Published: February 2012

AbstractDifferent spectroscopic techniques were applied for studying the structural properties of lysozyme in salt‐free aqueous solutions. The results of vibrational and Brillouin scattering measurements were compared to obtain both single‐molecule and collective properties of the solutions. The characterization of the protein system, from the conformation of the polypeptide chain to the exposure of side chains to the solvent and the arrangement of the solution network, was then achieved in the range 25–85 °C. Through the analysis of the indole breathing mode, a different environment for the six tryptophan residues of an unfolded lysozyme could be evidenced. Short and long exposures to high temperatures were used to modulate the competition between the thermally induced reversible and irreversible denaturation processes. These different thermal treatments were applied to distinguish between the effects of global unfolding of the single molecule from those of self‐aggregation and gel formation. It has been observed that clusterization occurs at melting temperatures with slow kinetics; also, aggregates evolve from the completely unfolded state of the protein and lead to a sensitive increase in viscosity. This effect probably hinders any further conformational rearrangement of the molecules in the aggregate; thus as a consequence, the disordered structure of clusters does not change to give the β‐sheet organization, characteristic of filaments or fibrils. Copyright © 2011 John Wiley & Sons, Ltd.
A sampling design and model for estimating abundance of Nile crocodiles while accounting for heterogeneity of detectability of multiple observers
Authors: Shirley Matthew H. , Dorazio Robert M. , Abassery Ekramy , Elhady Amr Abd , Mekki Mohammed Saad , Asran Hosni Helmy 
Published: February 2012

AbstractAs part of the development of a management program for Nile crocodiles in Lake Nasser, Egypt, we used a dependent double‐observer sampling protocol with multiple observers to compute estimates of population size. To analyze the data, we developed a hierarchical model that allowed us to assess variation in detection probabilities among observers and survey dates, as well as account for variation in crocodile abundance among sites and habitats. We conducted surveys from July 2008–June 2009 in 15 areas of Lake Nasser that were representative of 3 main habitat categories. During these surveys, we sampled 1,086 km of lake shore wherein we detected 386 crocodiles. Analysis of the data revealed significant variability in both inter‐ and intra‐observer detection probabilities. Our raw encounter rate was 0.355 crocodiles/km. When we accounted for observer effects and habitat, we estimated a surface population abundance of 2,581 (2,239–2,987, 95% credible intervals) crocodiles in Lake Nasser. Our results underscore the importance of well‐trained, experienced monitoring personnel in order to decrease heterogeneity in intra‐observer detection probability and to better detect changes in the population based on survey indices. This study will assist the Egyptian government establish a monitoring program as an integral part of future crocodile harvest activities in Lake Nasser. © 2012 The Wildlife Society.