bluuebunny/crossref_metadata_2025 huggingface dataset:
Update of uremic toxin research by mass spectrometry
Authors: Niwa Toshimitsu
Published: February 2011

Mass spectrometry (MS) has been successfully applied for the identification and quantification of uremic toxins and uremia‐associated modified proteins. This review focuses on the recent progress in the MS analysis of uremic toxins. Uremic toxins include low‐molecular weight solutes, protein‐bound low‐molecular weight solutes, and middle molecules (peptides and proteins). Based on MS analysis of these uremic toxins, the pathogenesis of the uremic symptoms will be elucidated to prevent and manage the symptoms. Notably, protein‐bound uremic toxins such as indoxyl sulfate, p‐cresyl sulfate, and 3‐carboxy‐4‐methyl‐5‐propyl‐2‐furanpropionic acid have emerged as important targets of therapeutic removal. Hemodialysis even with a high‐flux membrane cannot efficiently remove the protein‐bound uremic toxins because of their high albumin‐binding property. The accumulation of these protein‐bound uremic toxins in the blood of dialysis patients might play an important role in the development of uremic complications such as cardiovascular disease. Indoxyl sulfate is the most promising protein‐bound uremic toxin as a biomarker of progress in chronic kidney disease. Novel dialysis techniques or membranes should be developed to efficiently remove these protein‐bound uremic toxins for the prevention and management of uremic complications. © 2011 Wiley Periodicals, Inc., Mass Spec Rev 30:510–521, 2011
Prognostic indicators from electrodiagnostic studies for ulnar neuropathy at the elbow
Authors: Friedrich Jason M. , Robinson Lawrence R.
Published: February 2011

Introduction: We examined the prognostic value of electrodiagnostic (EDX) studies for ulnar neuropathy at the elbow (UNE). Methods: In this retrospective study, EDX results were compared with subjective recovery (resolution of symptoms) and surgery in patients diagnosed with UNE. Results: Of the 193 patients, 59 with “definite” UNE were included in the analysis. The combination of conduction block across the elbow to the first dorsal interosseous (FDI) and normal distal compound muscle action potential (CMAP) amplitude from the abductor digiti minimi (ADM) was strongly associated with recovery: 86% of these subjects achieved full subjective recovery compared to only 7% without conduction block and with an abnormal CMAP. There were no EDX predictors of surgery. Conclusion: EDX results contain useful prognostic information in UNE. Muscle Nerve, 2011
Exclusion of WWP1 mutations in a cohort of dystroglycanopathy patients
Authors: Godfrey Caroline , Clement Emma , Abbs Stephen , Muntoni Francesco
Published: February 2011

Introduction:

Aberrant glycosylation of α‐dystroglycan is associated with a subset of clinically heterogeneous muscular dystrophies collectively referred to as the dystroglycanopathies. These autosomal‐recessive disorders span a wide spectrum of clinical severity ranging from Walker–Warburg syndrome, with severe brain and eye abnormalities, to mild adult‐onset limb‐girdle muscular dystrophy. To date, seven causative genes have been identified in the dystroglycanopathies, yet studies have suggested that a significant proportion of patients harbor mutations in novel genes.

Methods:

A homozygous missense alteration in the gene encoding ubiquitin ligase WW domain–containing protein 1 (WWP1), has recently been identified in the dystroglycanopathy chicken. We therefore investigated whether mutations in the human ortholog were present in a cohort of 33 dystroglycanopathy patients.

Results:

No clear pathogenic mutations were identified.

Conclusion:

The present findings indicate that WWP1 is not a common cause of human dystroglycanopathy. Muscle Nerve 44: 388–392, 2011
Axon cytoskeleton ultrastructure in chronic inflammatory demyelinating polyneuropathy
Authors: Fressinaud Catherine , Dubas Frédéric
Published: February 2011

Introduction: To detail the extent and pattern of axon cytoskeleton alterations in chronic inflammatory demyelinating polyneuropathy (CIDP).Methods: Nerve biopsies from 7 cases of CIDP, including 4 cases with severe fiber loss, were compared with 5 controls by morphometric transmission electron microscopy (TEM).Results: Despite demyelination of single fibers, myelin ultrastructure was otherwise normal. Contrary to immunolabeling, TEM revealed a decrease in neurofilament (NF) density in every case, although there were pronounced variations among fibers even in the same sample. The NF decrease reached the same extent in large‐ and small‐diameter fibers. It was observed in normally myelinated fibers, suggesting they were demyelinated at a distance from the section. Minimal inter‐NF distance increased roughly inversely to NF density. Microtubules increased in 3 cases previously characterized by increased growth‐associated protein (GAP‐43) immunolabeling.Conclusion:These data demonstrate the severity and constancy of axonal lesions, and especially of NF, in residual fibers in our cases of CIDP. Muscle Nerve 44: 332–339, 2011
Number of motor units in human abductor hallucis
Authors: Johns Richard K. , Fuglevand Andrew J.
Published: February 2011

Motor unit number was estimated for the human abductor hallucis (AH) muscle in 11 subjects by counting the number of increments in surface electromyographic responses to progressive increases in current–pulse amplitude applied to the muscle–nerve. The average motor unit count for AH (43) was substantially smaller than that estimated for other human muscles. Consequently, motor unit activity should be readily recordable up to high forces in AH, making it well suited for studies of recruitment and rate coding. Muscle Nerve, 2011
Multi‐constraint security policies for delegated firewall administration
Authors: Kropiwiec Cássio Ditzel , Jamhour Edgard , Penna Manoel Camillo , Pujolle Guy
Published: February 2011

This work presents a new approach to policy representation of network security. It introduces a high‐level language, where the security policies can be expressed by three policy models: mandatory, discretionary and security property. The proposed framework is capable of handling all three dimensions, being capable of generating the permissions from an abstract representation that is independent of how they are enforced, without violating the requirements of high‐level security. Each dimension can be defined by people with different roles; for example, rules of the mandatory model and of the security property model could be attributed to the personnel of risk management, while rules of the discretionary model can be delegated among the network administrators in various departments of the organization. This work also presents a mechanism to represent the features implemented by different firewall models and a mechanism for translating the abstract representation in the scripts to configure the firewalls. A formal specification of the policy model validates the refinement algorithm and a study of scalability is presented to demonstrate how the algorithm behaves in large networks. Copyright © 2011 John Wiley & Sons, Ltd.
An efficient block preconditioner for Jacobian‐free global–local multiscale methods
Authors: Rahul  , De Suvranu
Published: February 2011

In this paper, we develop a block preconditioner for Jacobian‐free global–local multiscale methods, in which the explicit computation of the Jacobian may be circumvented at the macroscale by using a Newton–Krylov process. Effective preconditioning is necessary for the Krylov subspace iterations (e.g. GMRES) to enhance computational efficiency. This is, however, challenging since no explicit information regarding the Jacobian matrix is available. The block preconditioning technique developed in this paper circumvents this problem by effectively deflating the spectrum of the Jacobian matrix at the current Newton step using information about only the Krylov subspaces corresponding to the Jacobian matrices in the previous Newton steps and their representations on those subspaces. This approach is optimal and results in exponential convergence of the GMRES iterations within each Newton step, thus minimizing expensive microscale computations without requiring explicit Jacobian formation in any step. In terms of both computational cost and storage requirements, the action of a single block of the preconditioner per GMRES step scales linearly as the number of degrees of freedom of the macroscale problem as well as the dimension of the invariant subspace of the preconditioned Jacobian matrix. Copyright © 2011 John Wiley & Sons, Ltd.
Maximizing opto‐mechanical interaction using topology optimization
Authors: Gersborg A. R. , Sigmund O.
Published: February 2011

This paper studies topology optimization of a coupled opto‐mechanical problem with the goal of finding the material layout which maximizes the optical modulation, i.e. the difference between the optical response for the mechanically deformed and undeformed configuration. The optimization is performed on a periodic cell and the periodic modeling of the optical and mechanical fields have been carried out using transverse electric Bloch waves and homogenization theory in a plane stress setting, respectively. Two coupling effects are included being the photoelastic effect and the geometric effect caused by the mechanical deformation.

For the studied objective and material choice it is concluded that the photoelastic effect and the geometric effect counteract each other, which yields designs which are fundamentally different if the optimization takes only one effect into account. When both effects are active a compromise is found; however, a strong regularization is needed in order to achieve reasonable 0–1 designs with a clear physical interpretation. Copyright © 2011 John Wiley & Sons, Ltd.
FBXW7 mutations typically found in human cancers are distinct from null alleles and disrupt lung development
Authors: Davis Hayley , Lewis Annabelle , Spencer‐Dene Bradley , Tateossian Hilda , Stamp Gordon , Behrens Axel , Tomlinson Ian
Published: February 2011

FBXW7 is the substrate recognition component of a SCF‐type E3 ubiquitin ligase. It has multiple targets such as Notch1, c‐Jun, and cyclin E that function in critical developmental and signalling pathways. Mutations in FBXW7 are often found in many types of cancer. In most cases, these mutations do not inactivate the protein, but are mono‐allelic missense changes at specific arginine resides involved in substrate binding. We have hypothesized that FBXW7 mutations are selected in cancers for reasons other than haploinsufficiency or full loss‐of‐function. Given that the existing mutant Fbxw7 mice carry null alleles, we created a mouse model carrying one of the commonly occurring point mutations (Fbxw7$^{R482{\rm{Q}}}$) in the WD40 substrate recognition domain of Fbxw7. Mice heterozygous for this mutation apparently developed normally in utero, died perinatally due to a defect in lung development, and in some cases showed cleft palate and eyelid fusion defects. By comparison, Fbxw7+/− mice were viable and developed normally. Fbxw7−/− animals died of vascular abnormalities at E10.5. We screened known FBXW7 targets for changes in the lungs of the Fbxw7R482Q/+ mice and found Tgif1 and Klf5 to be up‐regulated. Fbxw7$^{R482{\rm{Q}}}$ alleles are not functionally equivalent to heterozygous or homozygous null alleles, and we propose that they are selected in tumourigenesis because they cause a selective or partial loss of FBXW7 function. Copyright © 2011 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Differential proteomics analysis of amniotic fluid in pregnancies of increased nuchal translucency with normal karyotype
Authors: Cheng Po‐Jen , Wang Tzu‐Hao , Huang Shang‐Yu , Kao Chuan‐Chi , Lu Jen‐Hao , Hsiao Ching‐Hwa , Steven Shaw S. W.
Published: February 2011

Objectives

To investigate the functional roles of differentially expressed proteins in amniotic fluid supernatant (AFS) from normal karyotype pregnancies with increased nuchal translucency (NT).

Methods

AFS from fetuses with increased NT (>3.4 mm, N = 14) and control (<0.7 mm, N = 14) were analyzed by two‐dimensional electrophoresis and in‐gel digestion to identify the difference of expressed proteins between both groups. Targeted proteins were confirmed by western blot and ELISA. The roles of biological networks in pathophysiology of NT were determined using MetaCore mapping.

Results

Levels of apolipoprotein‐A1 (Entrez Gene ID 335), alpha‐1 antitrypsin (SERPINA1, ID 5265) and prolactin (ID 5617) were significantly decreased in AFS of fetuses with increased NT compared with those in controls. According to Gene Ontology terms, biological processes of functional networks were mainly involved in steroid metabolism. On the basis of the database of MetaCore, these proteins are considered as the potential biomarkers of cardiovascular disorders. The prediction of tissue distribution from this network in fetal organs such as liver, skin, and kidney supported that these three proteins may play different roles between two groups.

Conclusion

The combination of using quantitative proteomics and functional network analysis could integrally analyze the pathophysiology of fetuses with increased NT. Copyright © 2011 John Wiley & Sons, Ltd.
Thermomechanical and surface properties of novel poly(ether urethane)/polyhedral oligomeric silsesquioxane nanohybrid elastomers
Authors: Tan Juanjuan , Jia Zhiyuan , Sheng Dekun , Wen Xin , Yang Yuming
Published: February 2011

A series of linear polyurethane (PU) elastomers containing various amounts (ca. 2–10 wt%) of a diol‐functionalized polyhedral oligomeric silsesquioxane (diolPOSS) were synthesized from organic solvent dispersions. Fourier transform infrared spectroscopy was used to characterize the chemical structure of the diolPOSS‐reinforced PU. Transmission electron microscopy (TEM) indicated that the diolPOSS aggregation was formed in the polymer matrix at the scale of 20–50 nm. The introduction of diolPOSS into such system led to high glass transition temperature, enhanced storage modulus, and improved stability compared with the pristine PU according to the differential scanning calorimetry, dynamic mechanical analysis, and thermal gravimetric analysis, respectively. Moreover, contact angle measurements indicated a significant enhancement in surface hydrophobicity as well as a reduction in surface free energy after introducing diolPOSS into the synthesized PU. The improvement of surface properties could be ascribed to the enrichment of the diolPOSS moiety on the surface of the hybrids. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers
Effect of the addition of silane coupling agents on the properties of wollastonite‐reinforced poly(ether ether ketone) composites
Authors: Ma Gang , Yue Xigui , Zhang Shuling , Rong Changru , Wang Lifeng , Wang Guibin , Wang Hongliang
Published: February 2011

The wollastonite was grafted with different silane coupling agents, which could improve interface adhesion. Wollastonite and modified wollastonite‐reinforced poly(ether ether ketone) (PEEK) composites were prepared by melt blending. The mechanical properties, rheology behavior, and thermal properties of the composites were investigated. The modified wollastonite‐reinforced PEEK composites exhibited better mechanical properties than the unmodified wollastonite‐reinforced PEEK composites based on good interfacial adhesion. The composites had lower activation volume and complex shear viscosity. Furthermore, the modified wollastonite‐reinforced PEEK composites had higher crystallization peak temperature (Tc) and crystalline fraction (χc) compared with the unmodified wollastonite‐reinforced PEEK composites. This study shows that the traditional silane coupling agents could effectively improve the performance of PEEK composites. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers
Poly(ethylene terephthalate)/carbon nanotube composites prepared with chemically treated carbon nanotubes
Authors: Yesil Sertan , Bayram Goknur
Published: February 2011

Surfaces of multiwalled carbon nanotubes (CNT) were functionalized by treatment with strong acid mixture (purification) followed by modification with sodium dodecyl sulfate, poly(ethylene glycol) (PEG), and diglycidyl ether of Bisphenol A (DGEBA). Poly(ethylene terephthalate) (PET)‐based conductive polymer composites were prepared by using these CNT by means of melt mixing with a twin screw extruder. Amount of carboxylic acid groups on the CNT surface increased after acid treatment but decreased with surface modification due to the consumption of these groups during the chemical reactions between the surface modifiers and CNT surface. Fourier transformed infrared spectroscopy (FTIR) and nuclear magnetic resonance analyses of the composites revealed the increase in the interactions between PET and CNT surface after treatment with PEG and DGEBA. Mechanical strength of the composites prepared with modified CNT were higher than that of the untreated CNT‐filled composite owing to the enhanced interactions between PET and CNT. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers
The mobile phone as a tool in improving cancer care in Nigeria
Authors: Odigie V. I. , Yusufu L. M. D. , Dawotola D. A. , Ejagwulu F. , Abur P. , Mai A. , Ukwenya Y. , Garba E. S. , Rotibi B. B. , Odigie E. C.
Published: February 2011

Objective: The use of mobile phone as a tool for improving cancer care in a low resource setting.

Methods: A total of 1176 oncology patients participated in the study. Majority had breast cancer. 58.4% of the patients had no formal education; 10.7 and 9.5% of patients had college or graduate education respectively. Two out of every three patients lived greater than 200 km from hospital or clinic. One half of patients rented a phone to call.

Results: At 24 months, 97.6% (1132 patients) had sustained their follow‐up appointments as against 19.2% (42 patients) who did not receive the phone intervention. 72.8% (14 102 calls) were to discuss illness/treatment. 14% of the calls were rated as emergency by the oncologist. 86.2% of patients found the use of mobile phone convenient/excellent/cheap. 97.6% found the use of the phone worthwhile and preferred the phone to traveling long distance to hospital/clinic. Also the patients felt that they had not been forgotten by their doctors and were been taken care of outside the hospital/clinic.

Conclusions: Low resource countries faced with the burden of cancer care, poor patient follow‐up and poor psychosocial support can cash in on this to overcome the persistent problem of poor communication in their healthcare delivery. The potential is enormous to enhance the use of mobile phones in novel ways: developing helpline numbers that can be called for cancer information from prevention to treatment to palliative care. The ability to reach out by mobile phone to a reliable source for medical information about cancer is something that the international community, having experience with helplines, should undertake with colleagues in Africa, who are experimenting with the mobile phone potential. Copyright © 2011 John Wiley & Sons, Ltd.
Value of gas exchange recording at home in children receiving non‐invasive ventilation
Authors: Felemban Osama , Leroux Karl , Aubertin Guillaume , Miandy Fabrice , Damagnez Frédéric , Amorim Bruno , Ramirez Adriana , Fauroux Brigitte
Published: February 2011

Non‐invasive positive pressure ventilation (NPPV) is preferentially performed at home. The objectives of the study were to evaluate the feasibility of an overnight gas exchange recording at home and to compare recordings performed in the hospital and at home.

Twenty‐nine pairs of overnight gas exchange recordings during NPPV were performed at home and in the hospital in 11 children with neuromuscular disease and 13 children with other disorders treated with long‐term NPPV.

No technical problem occurred during the recordings performed at home and one pulse oximetry (SpO2) recording failed in the hospital. For the two groups, SpO2 and transcutaneous carbon dioxide (PtcCO2) values did not differ significantly between the hospital and the home. However, correlations between SpO2 and PtcCO2 values obtained in the hospital and at home were better for mean values than for minimal and maximal values, and in patients with other disorders as compared to patients with neuromuscular disease.

Overnight gas exchange recordings with NPPV by a combined PtcCO2/SpO2 monitor are feasible at home and show results comparable to hospital recordings. Home PtcCO2/SpO2 recordings may be integrated in the care of children treated with domiciliary NPPV and are associated with less disruption of family life and decreased health care costs. Pediatr. Pulmonol. 2011; 46:802–808. © 2011 Wiley‐Liss, Inc.
Mass spectrometry‐based proteomics of endoscopically collected pancreatic fluid in chronic pancreatitis research
Authors: Paulo Joao A. , Lee Linda S. , Wu Bechien , Banks Peter A. , Steen Hanno , Conwell Darwin L.
Published: February 2011

MS‐based investigation of pancreatic fluid enables the high‐throughput identification of proteins present in the pancreatic secretome. Pancreatic fluid is a complex admixture of digestive, inflammatory, and other proteins secreted by the pancreas into the duodenum, and thus is amenable to MS‐based proteomic analysis. Recent advances in endoscopic techniques, in particular the endoscopic pancreatic function test (ePFT), have improved the collection methodology of pancreatic fluid for proteomic analysis. Here, we provide an overview of MS‐based proteomic techniques as applied to the study of pancreatic fluid. We address sample collection, protein extraction, MS sample preparation and analysis, and bioinformatic approaches, and summarize current MS‐based investigations of pancreatic fluid. We then examine the limitations and the future potential of such technologies in the investigation of pancreatic disease. We conclude that pancreatic fluid represents a rich reservoir of potential biomarkers and that the study of the molecular mechanisms of chronic pancreatitis may benefit substantially from MS‐based proteomics.
Altered myofilament stoichiometry in response to heart failure in a cardioprotective α‐myosin heavy chain transgenic rabbit model
Authors: Stanley Brian A. , Graham David R. , James Jeanne , Mitsak Megan , Tarwater Patrick M. , Robbins Jeff , Van Eyk Jennifer E.
Published: February 2011

Purpose: Decreases in α myosin heavy chain (α‐MHC) is a common feature of human heart failure (HF), whereas α‐MHC overexpression in transgenic (TG) rabbits is cardioprotective against tachycardia‐induced cardiomyopathy (TIC). Hypothesizing that MHC isoform content alterations would impact sarcomere and mitochondrial energetics protein complement, we investigated the impact of α‐MHC overexpression on global cardiac protein expression.

Experimental design: Protein expression was assessed by two‐dimensional gel electrophoresis and MS on the extracts from TG and nontransgenic (NTG) rabbits under TIC or sham‐operated conditions.

Results: We observed significant changes in the levels of actin, myosin light chain 2, and desmin between the left ventricular (LV) tissue of TG and NTG animals. The proteome was broadly impacted, with significant changes in mitochondrial energetics and chaperone protein families. No changes were observed in total cellular MHC or in myofibril‐associated MHC. In myofibrils isolated from TGsham animals, only actin levels were altered in TGsham compared with NTGsham animals, suggesting careful myofibril assembly regulation.

Conclusions and clinical Relevance: These data suggest that myofibril protein composition may protect against TIC, emphasizing protein interconnectivity and demonstrating the need for broad‐based proteomic studies in understanding targeted genetic manipulations. This study identifies the targets for future development of cardioprotective agents and elucidates tachycardia‐induced heart failure pathways.
Binding of small molecules to cavity forming mutants of a de novo designed protein
Authors: Das Aditi , Wei Yinan , Pelczer Istvan , Hecht Michael H.
Published: February 2011

A central goal of protein design is to devise novel proteins for applications in biotechnology and medicine. Many applications, including those focused on sensing and catalysis will require proteins that recognize and bind to small molecules. Here, we show that stably folded α‐helical proteins isolated from a binary patterned library of designed sequences can be mutated to produce binding sites capable of binding a range of small aromatic compounds. Specifically, we mutated two phenylalanine side chains to alanine in the known structure of de novo protein S‐824 to create buried cavities in the core of this four‐helix bundle. The parental protein and the Phe→Ala variants were exposed to mixtures of compounds, and selective binding was assessed by saturation transfer difference NMR. The affinities of benzene and a number of its derivatives were determined by pulse field gradient spin echo NMR, and several of the compounds were shown to bind the mutated protein with micromolar dissociation constants. These studies suggest that stably folded de novo proteins from binary patterned libraries are well‐suited as scaffolds for the design of binding sites.
Conformational dynamics of recoverin's Ca2+‐myristoyl switch probed by 15N NMR relaxation dispersion and chemical shift analysis
Authors: Xu Xianzhong , Ishima Rieko , Ames James B.
Published: February 2011

Recoverin, a member of the neuronal calcium sensor (NCS) branch of the calmodulin superfamily, serves as a calcium sensor in retinal rod cells. Ca2+‐induced conformational changes in recoverin promote extrusion of its covalently attached myristate, known as the Ca2+‐myristoyl switch. Here, we present nuclear magnetic resonance (NMR) relaxation dispersion and chemical shift analysis on 15N‐labeled recoverin to probe main chain conformational dynamics. 15N NMR relaxation data suggest that Ca2+‐free recoverin undergoes millisecond conformational dynamics at particular amide sites throughout the protein. The addition of trace Ca2+ levels (0.05 equivalents) increases the number of residues that show detectable relaxation dispersion. The Ca2+‐dependent chemical shifts and relaxation dispersion suggest that recoverin has an intermediate conformational state (I) between the sequestered apo state (T) and Ca2+ saturated extruded state (R): T ↔ I ↔ R. The first step is a fast conformational equilibrium ([T]/[I] < 100) on the millisecond time scale (τexδω < 1). The final step (I ↔ R) is much slower (τexδω > 1). The main chain structure of I is similar in part to the structure of half‐saturated E85Q recoverin with a sequestered myristoyl group. We propose that millisecond dynamics during T ↔ I may transiently increase the exposure of Ca2+‐binding sites to initiate Ca2+ binding that drives extrusion of the myristoyl group during I ↔ R. Proteins 2011; © 2011 Wiley‐Liss, Inc.
Innate factors causing differences in gene flow frequency from transgenic rice to different weedy rice biotypes
Authors: Zuo Jiao , Zhang Lianju , Song Xiaoling , Dai Weimin , Qiang Sheng
Published: February 2011

BACKGROUND: The compatibility and outcrossing rates between transgenic rice and weedy rice biotypes have been studied in some previous cases. However, few studies have addressed the reasons for these differences. The present study compared the compatibility and outcrossing rates between transgenic rice and selected weedy rice biotypes using manual and natural crossing experiments to elucidate the key innate factors causing the different outcrossing rates.

RESULTS: Hybrid seed sets from manual crossing between transgenic rice and weedy rice varied from 31.8 to 82.7%, which correlated directly with genetic compatibility. Moreover, the significant differences in the quantity of germinated donor pollens and pollen tubes entering the weedy rice ovule directly contributed to the different seed sets. The natural outcrossing rates varied from 0 to 6.66‰. The duration of flowering overlap was the key factor influencing natural outcrossing. Plant and panicle height also affected outcrossing success.

CONCLUSION: From this study, it is concluded that the likelihood of gene flow between transgenic rice and weedy rice biotypes is primarily determined by floral synchronisation and secondarily influenced by genetic compatibility and some morphological characteristics. Copyright © 2011 Society of Chemical Industry
Nanocoax solar cells based on aligned multiwalled carbon nanotube arrays
Authors: Paudel T. , Rybczynski J. , Gao Y. T. , Lan Y. C. , Peng Y. , Kempa K. , Naughton M. J. , Ren Z. F.
Published: February 2011

We fabricated and studied solar cells based on a distributed nanocoax architecture by depositing amorphous silicon as photovoltaic medium on arrays of aligned multiwalled carbon nanotubes. These inexpensive cells demonstrate an initial efficiency of 6.1% that can be further enhanced by increasing the nanocoax density per unit area and improving the amorphous silicon quality.
Numerical investigation of the coupling between microdisk modes and quantum dots
Authors: Declair S. , Meier T. , Förstner J.
Published: February 2011

We numerically investigate the coupling between circular resonators and study strong light‐matter coupling of single as well as multiple circular resonators to quantum‐mechanical resonators in two dimensional model simulations. For all cases, the computed resonances of the coupled system as function of the detuning show anti‐crossings.

The obtained mode splittings of coupled optical resonators are strongly depending on distance and cluster in almost degenerate eigenstates for large distances, as is known from coupled resonator optical waveguides. Vacuum Rabi splitting is observed for a quantum dot strongly coupled to eigenmodes of single perfectly cylindrical resonators. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Microcavity mode structure investigations with high spatial resolution
Authors: Ahrens Thomas , Burau Gerolf K.G. , Stolz Heinrich , Reitzenstein Stephan , Forchel Alfred
Published: February 2011

Micropillar cavities of different diameters have been excited optically. The photoluminescence spectra of the top face emission have been measured while studying their intensity profile with high spatial resolution through the use of microscope objectives within the cryostat.

The “donut”‐shape of the cavity mode with the second highest intensity is shown for the 2.3 µm pillar. A transfer matrix method has been applied to estimate the spatial and spectral profile of the individual cavity modes for comparison with the experimental results. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Cross sectional evaluation of boron doping and defect distribution in homoepitaxial diamond layers
Authors: Araújo Daniel , Paz Alegre M. A. , García Antonio J. , Pilar Villar M. , Bustarret Etienne , Achatz Philipp , Volpe Pierre N. , Omnès Franck
Published: February 2011

In some diamond‐based semiconducting devices, large variations of doping level are required over short distances. Tools to determine doping level and defects distribution should therefore be developed. The present contribution shows the capabilities of electron microscopy in this field. Focused ion beam (FIB‐dual beam) cross section preparations allowed evaluating doping level in highly boron doped sample with doping transition down to some nm by diffraction contrast mode of transmission electron microscopy (CTEM) and by high angle annular dark field mode of scanning transmission electron microscopy (HAADF‐STEM). The sensibility of the latter is around 1019cm‐3 and, thus, cathodoluminescence (CL) is required for lower doping levels. Cross sectional analysis on FIB prepared lamella allowed to separate the epilayer behaviour from that of the substrate. Mid‐gap centers involving boron, hydrogen and, for some peaks, also nitrogen are revealed. sp2 bonds are also present in the grown epilayer. These transitions make difficult the observation of excitonic recombinations in the cross section configuration. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Efficient methods for detection of SiC and Si3N4 precipitates and filaments in multi‐crystalline silicon wafers and solar cells
Authors: Bakowskie R. , Petter K. , Eiternick S. , Lausch D. , Müller G.
Published: February 2011

Two easy and efficient methods are demonstrated to detect SiC and Si3N4 filaments and precipitates in multi‐crystalline silicon (mc‐Si) wafers and solar cells by Optical Light (OLM) Microscopy and Scanning Electron Microscopy (SEM). In the case of OLM the image is created in the dark field mode which clearly visualizes the grain boundaries decorated by filaments in acidic etched silicon solar cells. In the case of SEM the image is created by a combination of Secondary Electrons (SE) imaging and Back Scattered Electrons (BSE) imaging. By using this method a clear discrimination of precipitates with different chemical compositions is possible. Note that both methods make it possible to investigate and analyze relatively large sample areas in a comparatively short period of time. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Si+ ion implantation in silica and ion beam mixing in SiO2/Si interfaces
Authors: Fitting Hans‐Joachim , Zatsepin Dmitry A. , Fitting Kourkoutis Lena , Schmidt Bernd
Published: February 2011

Scanning transmission electron microscopy (STEM) in combination with electron energy loss spectroscopy (EELS), energy filtered transmission electron microscopy (EFTEM), soft X‐ray emission spectroscopy (SXES), and cathodoluminescence (CL) have been used to investigate Si nanocluster formation in amorphous silicon dioxide layers implanted with Si+ ions. As samples we have used amorphous, thermally grown SiO2 layers, 20 and 500 nm thick on Si substrate. The layers are doped by Si+ ions with energies of 12 and 150 keV and doses of 1016 and 5×1016 ions/cm2 leading to atomic dopant fractions of about 7 and 4 at% at mean depths of 20 and 200 nm, respectively. After high fluence Si+ ion implantation into and around the interface of the thin 20 nm a ‐SiO2 layer on c‐Si the formation of an ion‐beam mixed buffer layer SiOx in this region was detected by means of SXES and compared with a TRIDYN computer simulation. This buffer layer is extended over about 20 nm and consists mainly of an understoichiometric SiOx matrix with 2 > x > 0 and gradually decreasing of x into the Si substrate. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Intensity‐dependent ultrafast dynamics of injection currents in unbiased GaAs quantum wells
Authors: Pochwała Michał , Duc Huynh Thanh , Förstner Jens , Meier Torsten
Published: February 2011

The intensity dependence of optically‐induced injection currents in unbiased GaAs semiconductor quantum wells grown in [110] direction is investigated theoretically for a number of well widths. Our microscopic analysis is based on a 14 × 14 band k · p method in combination with the multisubband semiconductor Bloch equations. An oscillatory dependence of the injection current transients as function of intensity and time is predicted and explained. It is demonstrated that optical excitations involving different subbands and Rabi flopping are responsible for this complex dynamics. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Inhibition of Secretion, Production and Gene Expression of Mucin from Cultured Airway Epithelial Cells by Prunetin
Authors: Lee Hyun Jae , Lee Su Yel , Lee Mi Nam , Kim Jang‐Hyun , Chang Gyu Tae , Seok Jeong Ho , Lee Choong Jae
Published: February 2011

This study investigated whether prunetin significantly affects the secretion, production and gene expression of mucin from cultured airway epithelial cells. Confluent primary rat tracheal surface epithelial (RTSE) cells were pretreated with adenosine triphosphate (ATP) for 5 min and then chased for 30 min in the presence of prunetin to assess the effect on mucin secretion using enzyme‐linked immunosorbent assay (ELISA). At the same time, confluent NCI‐H292 cells were pretreated with prunetin for 30 min and then stimulated with epidermal growth factor (EGF) or phorbol 12‐myristate 13‐acetate (PMA) for 24 h, respectively. The MUC5AC mucin gene expression and mucin protein production were measured by reverse transcription‐polymerase chain reaction (RT‐PCR) and ELISA. The results were as follows: (1) prunetin significantly suppressed ATP‐induced mucin secretion from cultured RTSE cells; (2) prunetin inhibited the production of MUC5AC mucin protein induced by EGF or PMA from NCI‐H292 cells; (3) prunetin also inhibited the expression of MUC5AC mucin gene induced by EGF or PMA from NCI‐H292 cells. This result suggests that prunetin can regulate the secretion, production and gene expression of mucin, by directly acting on airway epithelial cells. Copyright © 2011 John Wiley & Sons, Ltd.
Wound‐healing Properties of the Oils of Vitis vinifera and Vaccinium macrocarpon
Authors: Shivananda Nayak B. , Dan Ramdath D. , Marshall Julien R. , Isitor Godwin , Xue Sophia , Shi John
Published: February 2011

Vitis vinifera (grape) and Vaccinium macrocarpon (cranberry) are well known medicinal plants; most of the pharmacologically active phytochemicals have been isolated from the skin, fruit juice, fermented extract and alcohol fractions of the plants above. Here, the pharmacological properties of the phytochemical constituents present in oils of cranberry and grape were investigated. The oil of grape and cranberry has been evaluated for their wound healing activity by using an excision wound model in rats. The animals were divided into four groups of six each (n = 6). The experimental group 1 and 2 animals were treated topically with the grape and cranberry oil (100 mg/kg body weight), respectively. The controls were treated with petroleum jelly. The standard group of animals were treated with mupirocin ointment (100 mg/kg body weight). The healing was assessed by the rate of wound contraction and hydroxyproline content. On day 13, animals treated with cranberry oil exhibited a (88.1%) reduction in the wound area compared with grape‐oil treated (84.6%), controls (74.1%) and standard group animals (78.4%) (p < 0.001). The hydroxyproline content of the granulation tissue was significantly higher in the animals treated with cranberry and the grape‐oil (p < 0.000). Comparative investigation of the curative properties of the oils of V. vinifera and V. macrocarpon revealed a significant result which suggests their wound‐healing potential. Copyright © 2011 John Wiley & Sons, Ltd.
Infusions and Decoctions of Mixed Herbs used in Folk Medicine: Synergism in Antioxidant Potential
Authors: Guimarães Rafaela , Barros Lillian , Carvalho Ana Maria , Ferreira Isabel C. F. R.
Published: February 2011

Infusions (herbal teas) and decoctions are used frequently to administer oral doses of herbs. Although some herbs are used as single ingredients, they are often prepared as mixtures, as reported by numerous ethnobotanical surveys. The present work was carried out to identify the different types of interaction (synergistic, additive and antagonistic effects) which may be found in the antioxidant activity of preparations from mixtures of the popular herbs Aloysia citrodora (lemon verbena), Foeniculum vulgare (fennel) and Mentha spicata (spearmint). Herbs were prepared using traditional methods, and the effects after different periods of storage, up to 120 days, were also evaluated. Antioxidant activity was evaluated using DPPH radical scavenging activity, reducing power and inhibition of lipid peroxidation by the β‐carotene – linoleate system and the TBARS assay. Known antioxidant compounds such as total phenolics, flavonoids, ascorbic acid and reducing sugars were also determined. Spearmint was found to be present in the herb mixtures with the greatest antioxidant activity and these also had the highest flavonoid content. The most potent antioxidant activity was found in combinations of different herbs, suggesting synergistic effects. Copyright © 2011 John Wiley & Sons, Ltd.
Angelica acutiloba Root Attenuates Insulin Resistance Induced by High‐Fructose Diet in Rats
Authors: Liu I‐Min , Tzeng Thing‐Fong , Liou Shorong‐Shii , Chang Chia Ju
Published: February 2011

Angelica acutiloba root (Japanese Dong Quai), used for treatment of gynecological disorders, is currently cultivated in Taiwan. The present study evaluated the preventative effect of Angelica acutiloba root (Japanese Dong Quai) on the induction of insulin resistance. Insulin resistance was induced in rats by feeding a high fructose diet for 6 weeks. Thereafter, the rats were maintained on the same diet and treated with oral A. acutiloba root extract or pioglitazone once daily for 8 weeks. At the end of treatment, the degree of basal insulin resistance was measured by homeostasis model assessment (HOMA‐IR). Insulin sensitivity was calculated using the composite whole body insulin sensitivity index (ISIcomp). Protein expression was evaluated by immunoblotting. A. acutiloba (300 mg/kg/day) displayed similar characteristics to pioglitazone (20 mg/kg/day) in reducing HOMA‐IR and elevating ISIcomp. Elevated glycosylated hemoglobin levels and hyperinsulinemia were ameliorated by A. acutiloba treatment without hepatotoxic or nephrotoxic effects. A. acutiloba treatment improved dyslipidemia, induced lipoprotein lipase activity and enhanced hepatic glycogen accumulation. Further, A. acutiloba treatment enhanced the action of insulin on muscle glucose transporter subtype 4 translocation and attenuated hepatic phosphoenolpyruvate carboxykinase expression. The findings suggest that A. acutiloba may be an effective ethnomedicine for improving insulin sensitivity. Copyright © 2011 John Wiley & Sons, Ltd.
Cardamonin Stimulates Glucose Uptake through Translocation of Glucose Transporter‐4 in L6 Myotubes
Authors: Yamamoto Norio , Kawabata Kyuichi , Sawada Keisuke , Ueda Manabu , Fukuda Itsuko , Kawasaki Kengo , Murakami Akira , Ashida Hitoshi
Published: February 2011

Glucose transporter‐4 (GLUT4) is a transmembrane protein that plays a major role in insulin‐mediated glucose transport in muscle and adipocytes. For glucose transport to occur, the GLUT4 protein needs to be translocated from the intracellular pool to the plasma membrane, and certain compounds may enhance this process. The present study investigated the promotion of glucose uptake in differentiated L6 myotubes by cardamonin, isolated from Alpinia katsumadai. Cardamonin increased translocation of GLUT4 to the plasma membrane in L6 cells, but did not activate protein kinase C ζ/λ, Akt, or AMP‐activated protein‐kinase, all of which are known to regulate GLUT4 translocation. The glucose‐uptake‐promoting activity of cardamonin was not lowered by treatment with a phosphatidylinositol 3′‐kinase inhibitor. These results suggest that cardamonin is a promising active compound for maintaining glucose homeostasis, and that it acts via an unknown mechanism that does not involve activation of the downstream insulin signal and AMP‐activated protein kinase. Copyright © 2011 John Wiley & Sons, Ltd.
The H‐Bond activation mechanism and enantioselectivity in stepwise conjugate amine addition promoted by hydroxyl‐thiourea catalyst
Authors: Lu Nan , Chen Dezhan , Mi Shizhen , Zhang Guiqiu , Zhang Honghong
Published: February 2011

The H‐bond activation mechanism and enantioselectivity of hydroxyl‐thiourea catalyst in conjugate amine addition of O‐benzyl hydroxylamine to pyrazole crotonate is investigated using density functional theory (DFT) calculations. Two competing activation models are explored in detail. CN bond formation is stepwise in both of the two models. The enantioselective (S)‐channel is more favorable than (R)‐channel via the calculated barriers. The enantioselectivity originated from si face preferable than re face can be attributed to the H‐bonded network provided by thiourea and hydroxyl groups in rate‐determining step. The enantiomeric excess (ee) values predicted through ONIOM calculations are in line with the experiment. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2011
Static and dynamic dipole polarizabilities and electron density at origin: Ground and excited states of hydrogen atom confined in multiwalled fullerenes
Authors: Motapon O. , Ndengue S. A. , Sen K. D.
Published: February 2011

We report accurate computations of static and dynamic dipole polarizabilities for the ground and excited states of hydrogen atom confined at the center of either a single and/or multiwalled fullerene cage, using the Galerkin variational method developed on a B‐spline basis set. The results obtained in the cage‐free case are in good agreement with other numerical techniques such as the mapped Fourier grid method. It is shown that the addition of new walls does not modify the polarizability of the ground state, but changes significantly those of the excited states. A condition on the ratio of the scaled second derivative of density to the scaled density evaluated at the nuclear position is tested in case of the cage confined atoms for the first time, and the significance of such numerical results are discussed. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2011
The role of hydrogen bonds in protein–ligand interactions. DFT calculations in 1,3‐dihydrobenzimidazole‐2 thione derivatives with glycinamide as model HIV RT inhibitors
Authors: Kretschmer Robert , Kinzel Daniel , González Leticia
Published: February 2011

The structures, redshifts, binding energies, Bader analysis, and shared‐electron numbers (SENs) of 1,3‐dihydrobenzimidazole‐2‐thione (DBS) derivatives hydrogen bonded to glycinamide were calculated by the means of DFT methods. The DBS–glycinamide complex serves as a model for human immunodeficiency virus reverse transcriptase inhibitors of theN‐dimethylallyl‐6‐methyl‐4,5,6,7‐tetrahydroimidazo‐[4,5,1‐jk][1,4]‐benzodiazepin‐2(1H)‐thione family. A correlation between experimental Gibbs free energies, associated biological activities and the energy of the hydrogen bond obtained with the SEN method showed a linear relationship for different substitution patterns. Our results suggest that efficient inhibitors are those substituted in the 8‐position with electron‐withdrawing small substituents. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem 112:1786–1795, 2012
Quantum chemical modeling of 1,1‐proton transfer reaction catalyzed by a cofactor‐independent α‐methylacyl‐CoA racemase
Authors: Li Xue , Zheng Qing‐Chuan , Zhang Hong‐Xing
Published: February 2011

α‐Methylacyl‐CoA racemases (AMACR) are essential enzymes for branched‐chain lipids and drugs metabolism. AMACR catalyzes the chiral inversion of (2R) and (2S)‐methylacyl‐CoA esters in both directions. In this study, we investigated the catalytic mechanism of Mycobacterium tuberculosis (MCR) α‐methylacyl‐CoA racemase by using the density functional theory with the hybrid functional B3LYP. Our calculations elucidate and support the mechanism proposed by Prasenjit Bhaumik. His126 and Asp156 serve as the acid/base‐pair residues in the 1,1‐proton transfer catalytic reaction. From the optimized structures, it can be seen that an enolate intermediate is formed and the possibility of forming a ketene or a carbanion intermediate is excluded. By comparing the energy barriers, we could consider that the deprotonation step is the rate‐determined step in the invert direction from (S)‐ to (R)‐enantiomer. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2012