bluuebunny/crossref_metadata_2025_split huggingface dataset:
Folding determinants of disulfide bond forming protein B explored by solution nuclear magnetic resonance spectroscopy
Authors: Hwang Soyoun , Hilty Christian 
Published: January 2011

AbstractThe two‐stage model for membrane protein folding postulates that individual helices form first and are subsequently packed against each other. To probe the two‐stage model, the structures of peptides representing individual transmembrane helices of the disulfide bond forming protein B have been studied in trifluoroethanol solution as well as in detergent micelles using nuclear magnetic resonance (NMR) and circular dichroism spectroscopy. In TFE solution, peptides showed well‐defined α‐helical structures. Peptide structures in TFE were compared to the structures of full‐length protein obtained by X‐ray crystallography and NMR. The extent of α‐helical secondary structure coincided well, lending support for the two‐stage model for membrane protein folding. However, the conformation of some amino acid side chains differs between the structures of peptide and full‐length protein. In micellar solution, the peptides also adopted a helical structure, albeit of reduced definition. Using measurements of paramagnetic relaxation enhancement, peptides were confirmed to be embedded in micelles. These observations may indicate that in the native protein, tertiary interactions additionally stabilize the secondary structure of the individual transmembrane helices. Proteins 2011. © 2011 Wiley‐Liss, Inc.
New insights into the GABAA receptor structure and orthosteric ligand binding: Receptor modeling guided by experimental data
Authors: Sander Tommy , Frølund Bente , Bruun Anne Techau , Ivanov Ivaylo , McCammon James Andrew , Balle Thomas 
Published: January 2011

AbstractGABAA receptors (GABAARs) are ligand gated chloride ion channels that mediate overall inhibitory signaling in the CNS. A detailed understanding of their structure is important to gain insights in, e.g., ligand binding and functional properties of this pharmaceutically important target. Homology modeling is a necessary tool in this regard because experimentally determined structures are lacking. Here we present an exhaustive approach for creating a high quality model of the α1β2γ2 subtype of the GABAAR ligand binding domain, and we demonstrate its usefulness in understanding details of orthosteric ligand binding. The model was constructed by using multiple templates and by incorporation of knowledge from biochemical/pharmacological experiments. It was validated on the basis of objective energy functions, its ability to account for available residue specific information, and its stability in molecular dynamics (MD) compared with that of the two homologous crystal structures. We then combined the model with extensive structure‐activity relationships available from two homologous series of orthosteric GABAAR antagonists to create a detailed hypothesis for their binding modes. Excellent agreement with key experimental data was found, including the ability of the model to accommodate and explain a previously developed pharmacophore model. A coupling to agonist binding was thereby established and discussed in relation to activation mechanisms. Our results highlight the importance of critical evaluation and optimization of each step in the homology modeling process. The approach taken here can greatly aid in increasing the understanding of GABAARs and related receptors where structural insight is limited and reliable models are difficult to obtain. Proteins 2011; © 2011 Wiley‐Liss, Inc.
Domain structure of magnetic nanotube with transverse anisotropy
Authors: Usov N. A. , Zhukov A. , González J. 
Published: January 2011

AbstractThe magnetic properties of soft magnetic nanotubes with a transverse anisotropy are investigated by means of numerical simulation. The structure of isolated bamboo domain wall and its evolution under the influence of axial uniform magnetic field, as well as a circular magnetic field of a DC current is investigated. Also the stability of various bamboo domain structures (BDS) in axial and circular magnetic fields is studied. It is found that the magnetic field that saturates a nanotube in axial direction is close to the anisotropy field. On the other hand, the interval of circumferential magnetic fields where a BDS can exist is two orders of magnitudes shorter.
Absorption spectra of azobenzenes simulated with time‐dependent density functional theory
Authors: Jacquemin Denis , Preat Julien , Perpète Eric A. , Vercauteren Daniel P. , André Jean‐Marie , Ciofini Ilaria , Adamo Carlo 
Published: January 2011

AbstractUsing time‐dependent density functional theory and the polarizable continuum model, we have simulated the absorption spectra of an extended series of azobenzene dyes. First, we have determined a theoretical level optimal for this important class of dyes, and it turned out that a C‐PCM‐CAM‐B3LYP/6‐311+G(d,p)//C‐PCM‐B3LYP/6‐311G(d,p) approach represents an effective compromise between chemical accuracy and computational cost. In a second stage, we have compared the theoretical and experimental transition energies for 46 n → π☆ and 141 π → π☆ excitations. For the full set, that spans over a 302–565 nm domain, we obtained a mean absolute deviation of 13 nm (0.10 eV) and a linear correlation coefficient of 0.95, illustrating the accuracy of our approach, though some significant outliers pertained. In a last step, the impact of several modifications, that is, trans/cis isomerization, variation of the acidity of the medium and azo/hydrazo tautomerism have been modeled with two functionals. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2010
Theoretical spectroscopic studies of InI and InI+
Authors: Banerjee Amartya , Das Kalyan Kumar 
Published: January 2011

AbstractRelativistic configuration interaction calculations are carried out to study the electronic structure and spectroscopic properties of InI and InI+. Potential energy curves of the ground and a number of low‐lying states are constructed. Spectroscopic parameters of the bound states of both species are computed and compared with the experimental and other theoretical data. Effects of spin‐orbit coupling on the spectroscopic properties are studied. Because of the presence of the heavy atoms the effect is large. The spin‐orbit splitting of the ground state (X2Π) of InI+ is more than 8350 cm−1. As a result of the strong spin‐orbit interaction between X2Π and A2Σ+ of InI+, the potential energy curve of A2Σ becomes repulsive. Radiative lifetimes for the spin‐forbidden transitions such as A3Π−X1Σ and B3Π1 −X1Σ of InI and spin‐allowed transitions such as B2Σ+−A2Σ+, C2Π−A2Σ+, and B2Σ+−X2Π are calculated. Vertical and adiabatic ionization energies of InI and the electric dipole moments of both the neutral and ionic species are estimated. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2010
Strong anion exchange liquid chromatographic separation of protein amino acids for natural 13C‐abundance determination by isotope ratio mass spectrometry
Authors: Abaye Daniel A. , Morrison Douglas J. , Preston Tom 
Published: January 2011

AbstractAmino acids are the building blocks of proteins and the analysis of their 13C abundances is greatly simplified by the use of liquid chromatography (LC) systems coupled with isotope ratio mass spectrometry (IRMS) compared with gas chromatography (GC)‐based methods. To date, various cation exchange chromatography columns have been employed for amino acid separation. Here, we report strong anion exchange chromatography (SAX) coupled to IRMS with a Liquiface interface for amino acid δ13C determination. Mixtures of underivatised amino acids (0.1–0.5 mM) and hydrolysates of representative proteins (prawns and bovine serum albumin) were resolved by LC/IRMS using a SAX column and inorganic eluents. Background inorganic carbon content was minimised through careful preparation of alkaline reagents and use of a pre‐injector on‐line carbonate removal device. SAX chromatography completely resolved 11 of the 16 expected protein amino acids following acid hydrolysis in underivatised form. Basic and neutral amino acids were resolved with 35 mM NaOH in isocratic mode. Elution of the aromatic and acidic amino acids required a higher hydroxide concentration (180 mM) and a counterion (NO, 5–25 mM). The total run time was 70 min. The average δ13C precision of baseline‐resolved peaks was 0.75‰ (range 0.04 to 1.06‰). SAX is a viable alternative to cation chromatography, especially where analysis of basic amino acids is important. The technology shows promise for 13C amino acid analysis in ecology, archaeology, forensic science, nutrition and protein metabolism. Copyright © 2011 John Wiley & Sons, Ltd.
A novel matrix‐assisted laser desorption/ionisation mass spectrometry imaging based methodology for the identification of sexual assault suspects
Authors: Bradshaw Robert , Wolstenholme Rosalind , Blackledge Robert D. , Clench Malcolm R. , Ferguson Leesa S. , Francese Simona 
Published: January 2011

AbstractAn increase in the use of condoms by sexual offenders has been observed. This is likely to be due both to the risk of sexually transmitted diseases and to prevent the transfer of DNA evidence. In this scenario the detection of condom lubricants at a crime scene could aid in proving corpus delicti. Here we show a novel application of Matrix‐Assisted Laser Desorption/Ionisation Mass Spectrometry Imaging (MALDI MSI) for mapping the fingermark ridge pattern simultaneously to the detection of the condom lubricant within the fingermark itself. Two condom brands have been investigated to prove the concept. Condoms were handled producing lubricant‐contaminated fingermarks. Images of the ridge pattern were obtained simultaneously to the detection of two lubricants, even several weeks after the fingermark deposition. The results therefore show the potential of MALDI MSI to link the suspect (identification through fingermark ridge pattern) to the crime (detection of condom lubricant) in one analysis. This would enable forensic scientists to provide evidence with stronger support in alleged cases of sexual assault. Copyright © 2011 John Wiley & Sons, Ltd.
Liquid chromatography/atmospheric pressure photoionization tandem mass spectrometry for analysis of Dechloranes
Authors: Zhou Simon Ningsun , Reiner Eric J. , Marvin Chris H. , Helm Paul A. , Shen Li , Brindle Ian D. 
Published: January 2011

AbstractLiquid chromatography/atmospheric pressure photoionization tandem mass spectrometry (LC/APPI‐MS/MS) was investigated as an instrumental method for the analysis of the halogenated norbornene flame retardants, Mirex, Dechloranes 602, 603, 604, and Dechlorane Plus (DP). The LC separation was optimized by screening a variety of stationary and mobile phases, resulting in a short LC separation time of 5 min. Different atmospheric pressure ionization approaches were examined including electrospray ionization, atmospheric pressure chemical ionization, and APPI, each with and without post‐column addition. APPI without post‐column addition was chosen for providing the best ionization response. The optimized LC/APPI‐MS/MS approach resulted in instrument detection limits ranging between 25 and 50 pg. Good linearity was also achieved (up to 25.0 ng/µL; R >0.999). The method was applied to extracts of environmental samples including surface water, fish and sediments for screening purposes, and the results agreed well with those obtained by gas chromatography/mass spectrometry. Copyright © 2011 John Wiley & Sons, Ltd.
Metal Forming of Vibration‐Damping Composite Sheets
Authors: Engel Bernd , Buhl Johannes 
Published: January 2011

AbstractComposite materials with vibrations damping qualities can be made of two steel sheets enclosing a viscoelastic plasticcorelayer. These sandwich sheets often need to be formed. Material parameters are determined to describe the forming process. Based on these parameters, pilot studies are carried out in order to develop recommendations for forming this class of material.
Impact of PET‐CT on Primary Staging and Response Control on Multimodal Treatment of Esophageal Cancer
Authors: Thurau Kirsten , Palmes Daniel , Franzius Christiane , Minin Evgeny , Senninger Norbert , Juergens Kai Uwe , Bruewer Matthias 
Published: January 2011

AbstractBackgroundThe predictive value of positron emission tomography‐computed tomography (PET‐CT) in primary staging and response control in patients with esophageal carcinoma (EC) is under discussion. In the present study initial staging and metabolic response of PET‐CT was correlated with tumor regression and survival in patients with multimodal treatment of EC.MethodsThe authors conducted a retrospective analysis on a prospective database for 83 patients with EC (42 squamous cell, 39 adenocarcinoma, 2 anaplastic carcinoma) undergoing PET‐CT for primary staging. Twenty‐four of the patients underwent primary esophagectomy, 9 had palliative treatment, and 50 neoadjuvant radiochemotherapy (cisplatin, 5‐fluorouracil; 50.4 Gy). The PET‐CT study was repeated 6 weeks after induction of chemotherapy and compared with endoscopic ultrasound (EUS). For response control, the metabolic response (tumor standardized uptake value [SUV] reduction) was correlated with histopathologic (ypT0‐4) and histomorphologic response (tumor regression) and survival.ResultsAt primary staging 81 of 83 EC (97.5%) showed an increased SUV uptake correlating with the EUS tumor stage. Suspicious lymph nodes were detected in 51 (61.4%) patients by PET‐CT and 66 (79.5%) were detected by EUS. Fifteen patients had additional findings on PET‐CT examination leading to a change in therapy in 9 patients (10.3%). Of 50 patients receiving a second PET‐CT study, a SUV reduction >50% correlated with major histomorphologic response (tumor regression grade 4, <10% vital tumor cells) and histopathologic response (ypT0 ypN0). Furthermore, these patients showed a significantly increased survival (33.1 ± 3.5 months) compared to non‐responders (21.7 ± 3.3 months; p = 0.02) and patients after primary surgery (29 ± 3.2 months; p = 0.05).ConclusionsThe present study shows that PET‐CT is a valuable tool for primary staging and response control in multimodal treatment of patients with EC.
Physical activity, genes, and lifetime predisposition to chronic disease
Authors: Kujala Urho M. 
Published: January 2011

Abstract
This mini-review summarizes the main associations between physical activity and chronic diseases and discusses the basic concepts related to the role of genetic factors in studies evaluating the effects of physical activity/exercise therapy on chronic disease prevention/treatment during the life course. Many observational cohort studies have shown that high physical activity during young adulthood or middle age is associated with reduced later life morbidity, mobility limitations and mortality. Physical activity or exercise therapy has a positive effect on health via many disease-specific mechanisms. The most consistent finding of the various randomized controlled studies conducted to date is that aerobic/functional capacity and/or muscle strength can be improved by exercise training among patients with different chronic diseases. Genes are known to play a role in chronic disease predisposition and to contribute to physical fitness levels, physical activity participation and ageing. Physical fitness, physical activity and health outcomes may be partly due to underlying genetic factors that have a favourable effect on all these traits (genetic pleiotropy). This means that in observational studies, the relationship between baseline activity and the later occurrence of diseases may not be interpreted entirely as causal. Increased knowledge on the role of nuclear genome, mitochondrial genome, epigenetics, telomeres and regulation of gene expression will increase our understanding of their relationships with physical activity and morbidity.
The modulation of pain by attention and emotion: A dissociation of perceptual and spinal nociceptive processes
Authors: Royl Mathieu , Lebuisl Ariane , Peretzl Isabelle , Rainvillel Pierre 
Published: January 2011

AbstractEmotions and attention have been shown to influence the perception of pain and several psychophysiological studies have suggested an implication of descending modulatory mechanisms to explain these effects. However, the specificity of the neurophysiological mechanisms underlying the emotional and attentional modulation of pain still remains unclear. In order to differentiate the supra‐spinal and spinal mechanisms involved in emotional and attentional modulation of pain, we measured pain perception (self‐ratings) and the RIII reflex in healthy volunteers during the presentation of pleasant, unpleasant and neutral pictures, as well as during a baseline condition with no visual distractor (Experiment 1). In a second experiment, we manipulated the emotional arousal induced by pleasant and unpleasant pictures in order to compare more directly the effects of distraction and arousal. Whereas emotional valence influenced pain and the amplitude of the RIII reflex in the same direction (negative>positive), distraction by neutral pictures reduced pain but increased the RIII reflex relative to baseline. Increased arousal further potentiated the effects of negative valence on both pain and the RIII reflex and the effects of positive emotions on pain, as previously reported. However, arousal did not potentiate the inhibitory effect of positive pictures on the RIII and seems insufficient to account for the effect of distraction on the RIII. Overall, these data provide further evidence that attention and emotion modulate pain through partially dissociable neurophysiological mechanisms.
Help Stop Teenage Pregnancy!
Authors: Joyce Alison , Yates David 
Published: January 2011

Practical relevance Neutering kittens at an early age, typically between 6 and 14 weeks, has received increasing attention and gained prominence in recent years, particularly in the United States and in shelter medicine in the UK. However, in private practice it has yet to be generally endorsed. Global importance Among many of the animal welfare charities, early neutering is seen as a crucial step in conquering and controlling cat overpopulation. Clinical challenges Physiological differences between kittens and adult cats are very important to consider before undertaking elective early neutering. Increased sensitivity to drugs, prolongation of effects and a limited capacity for cardiovascular compensation are the principal anaesthetic concerns in kittens. Evidence base The optimal age for neutering, traditionally deemed to be between 5 and 8 months, is now questioned, as short- and longer-term studies demonstrate no significant behavioural and physical advantages conferred by traditional-age neutering. Furthermore, a number of safe anaesthetic and surgical protocols have been documented that produce lower morbidity and similar mortality rates in early-age neuters compared with traditional-age neuters.
Feline Systemic Hypertension
Authors: Jepson E Rosanne 
Published: January 2011

Practical relevance The increased availability of indirect blood pressure monitoring devices in clinical practice over the past decade has highlighted the significance of systemic hypertension in the feline population. Without routine monitoring and appropriate intervention, cats with undiagnosed systemic hypertension may first be presented with sudden-onset blindness as a consequence of either hyphaema or retinal detachment. Clinical challenges The primary aim in the early diagnosis and treatment of systemic hypertension is prevention of hypertensive target organ damage (with respect to the eye, kidney, cardiovascular and central nervous systems, in particular). A prerequisite is a knowledge of the pathophysiological mechanisms and disease conditions that may contribute to the development of hypertension. This allows the clinician to determine those cases in which blood pressure assessment and longitudinal monitoring is essential and can assist in determining appropriate therapeutic strategies for control of blood pressure. Recent studies have also begun to explore the relationship that systemic hypertension may have with proteinuria and the progression of kidney disease. Patient group The geriatric cat appears most susceptible to the development of systemic hypertension, and monitoring of systolic blood pressure is often advocated as part of a routine health screen in cats over 9–12 years old. Consideration must also be given to cats suspected of having an underlying disease such as chronic kidney disease or hyperthyroidism, or which are receiving therapeutic agents, irrespective of their age. Evidence base Much of our understanding of the pathogenesis of feline hypertension is extrapolated from studies performed in experimental animal models or in human patients, and interspecies differences are often poorly understood.
The Epidemiology of Ankle Sprain during Hiking in Uniformed Groups
Authors: Oscar Lam Wai-Ho , Tun-Hing Lui , Kai-Ming Chan 
Published: January 2011

Purpose To determine the prevalence of ankle sprain during hiking training in uniformed groups and identify the risk factors of ankle sprain and the risk factors associated with residual problems after ankle sprain. Methods A retrospective cross-sectional study involved 590 members of a uniformed group from secondary schools and their leaders by means of a self-administered anonymous questionnaire. Results The prevalence of ankle sprain was 9.15%. Most of them were lateral sprains (70.4%) and occurred in scree ground (51.9%) and downhill slope (50.0%). Subjects who are “older” aged, are overweight, are leaders in uniformed groups, have a past history of ankle sprain or problem, have a long-term lower limb injury, wear inadequate sized or tight shoes, and use hiking poles, have significant risks. The prevalence of having residual problems after ankle sprains was 48.14%, and the most common one was residual ankle pain (25.0%). Conclusion Uniformed group leaders and members should be aware of the risk factors of ankle sprain during hiking training in the countryside. They should also be aware of the importance of proper treatment and rehabilitation to prevent residual ankle problem. Level of Evidence Level II prognostic study.