bluuebunny/crossref_metadata_2025 huggingface dataset:
Novel Benzimidazole Analogs as Inhibitors of EGFR Tyrosine Kinase
Authors: Yadav Soni , Sinha Deepa , Singh Sanjay K. , Singh Vinay K.
Published: May 2012

A series of new benzimidazole congeners were synthesized, and their structures were elucidated on the basis of elemental analyses and spectral studies (1H NMR, FT‐IR and EI‐MS). Preliminary pharmacokinetic studies showed a promising outlook for further in vivo evaluation. The newly synthesized compounds were tested in vitro on human breast carcinoma cell line (MCF‐7) in which EGFR is highly expressed. Most of the tested compounds exhibited antitumor activity with IC50 values in the micro to nano molar range.
Cyclooxygenase‐2 inhibition and thromboxane A2 receptor antagonism attenuate hypoxic pulmonary vasoconstriction in a porcine model
Authors: Kylhammar D. , Rådegran G.
Published: May 2012

Aim

Hypoxic pulmonary vasoconstriction (HPV) causes pulmonary hypertension that may lead to right heart failure. We hypothesized that the COX‐2 inhibitor nimesulide and the thromboxane A2 receptor antagonist daltroban would attenuate HPV.

Methods

Haemodynamic measurements and blood sampling were performed in 18 anaesthetized, mechanically ventilated pigs, with mean ± SEM weights of 31.3 ± 0.6 kg, in normoxia (FiO2~0.21) and hypoxia (FiO2~0.10), before and 5, 15 and 45 min after initiation of right atrial infusion of nimesulide (n = 6) or daltroban (n = 6), respectively, and in six control pigs.

Results

Compared with normoxia, hypoxia (n = 18) increased mean pulmonary artery pressure by 15.8 ± 0.8 mmHg (P < 0.001), pulmonary vascular resistance (PVR) by 2.7 ± 0.3 WU (P < 0.05) and mean right atrial pressure by 2.3 ± 0.3 mmHg (P < 0.001). In the control pigs, mean pulmonary artery pressure, PVR and mean right atrial pressure remained stable (P = ns) throughout 45 min hypoxia, compared with hypoxia baseline. Nimesulide decreased mean pulmonary artery pressure by 3.7 ± 1.3 mmHg after 45 min (P < 0.013), as well as PVR by 0.8 ± 0.2 WU (P < 0.05), levelling off after 15 min. Daltroban transiently increased (P < 0.001) mean pulmonary artery pressure and mean right atrial pressure by 7.2 ± 1.2 and 2.7 ± 0.4 mmHg, respectively, but they returned to hypoxia baseline (P = ns) within 5 min. Daltroban then decreased mean pulmonary artery pressure to after 45 min be 4.2 ± 1.6 mmHg lower (P < 0.005) than at hypoxia baseline.

Conclusion

COX‐2 inhibition and thromboxane A2 receptor antagonism attenuate HPV by decreasing mean pulmonary artery pressure by approximately 10–11%, as measured 45 min after initiation of nimesulide or daltroban infusion respectively.
Non‐alcoholic fatty liver disease
Authors: TUYAMA Ana C. , CHANG Charissa Y.
Published: May 2012

Non‐alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in the Western world. It is closely associated with metabolic syndrome. The alarming epidemics of diabetes and obesity have fueled an increasing prevalence of NAFLD, particularly among these high‐risk groups. Histologically, NAFLD encompasses a disease spectrum ranging from simple steatosis to non‐alcoholic steatohepatitis (NASH), which is characterized by hepatocyte injury, inflammation, and variable degrees of fibrosis on liver biopsy. Non‐alcoholic steatohepatitis can progress to cirrhosis in a fraction of patients. There is currently little understanding of risk factors for disease progression and the disease pathogenesis has not been fully defined. Liver biopsy remains the gold standard for diagnosis. Weight loss, dietary modification, and the treatment of underlying metabolic syndrome remain the mainstays of therapy once the diagnosis is established. There are no well‐established pharmacological agents for treatment of NASH, although this is a subject of ongoing research.
Assessing the recommendations for the use of diagnostic imaging in clinical practice guidelines
Authors: Reed Martin H.
Published: May 2012

Accuracy is the primary evidence assessed when diagnostic imaging is evaluated in clinical practice guidelines. However, recommendations to not use diagnostic imaging are usually based not on its accuracy but on its lack of utility, that is its low Level 4 efficacy. If there is good clinical evidence that diagnostic imaging will not be useful in a clinical situation, the recommendation not to use it should be strong even if the evidence for its accuracy is of poor quality.
Attenuation of oxidant damage in the postconditioned heart involves non‐enzymatic response and partial catalytic protection
Authors: Arreguín Francisco , García Noemi , Hernández‐Reséndiz Sauri , Buelna‐Chontal Mabel , Correa Francisco , Olín‐Sandoval Viridiana , Medina‐Campos Omar Noel , Pedraza‐Chaverrí José , Zazueta Cecilia
Published: May 2012

Oxidant stress, among other effectors, is implicated in the sequel of myocardial reperfusion injury. It is generally accepted that maintaining the balance between oxidant and antioxidant signalling within the cell provides protection against reperfusion damage. The cardioprotective strategy of postconditioning (PC) reduces reperfusion injury through complex mechanisms; however, the contribution of the antioxidant system has not been fully investigated. In this study, isolated rat hearts were subjected to PC after 30 min global ischaemia, and then to 5 min (IR5) or 60 min of reperfusion (IR60). Postconditioning significantly increased the left ventricular developed pressure and the double product (heart rate × left ventricular developed pressure) for both early (PC5) and prolonged reperfusion (PC60, PC before 60 min of reperfusion). Necrotic tissue diminished to 10.8% in PC60 hearts, compared with 49% of infarct size measured in IR60 hearts (P < 0.05 versus IR60). Also, protein carbonylation and malondialdehyde levels decreased and were correlated with a significant augmentation in CuZn superoxide dismutase activity (P < 0.05, PC60 versus IR60) and increased glutathione redox state (GSH:GSSG ratio; P < 0.05, PC60 versus IR60). Diethylthiocarbamate, a non‐selective superoxide dismutase inhibitor, significantly diminished the protection afforded by PC when administered throughout the protocol. However, administration of this inhibitor only during reperfusion had no effect on PC‐induced cardioprotection. These results indicate that non‐enzymatic antioxidants account for the protective effect of PC, modifying the oxidant stress caused by ischaemic reperfusion in rats. The contribution of CuZn superoxide dismutase activity in the observed cardioprotective effect is less clear, and could be relevant if acting in concert with other PC‐activated mechanisms.
Sound propagation in saturated gas-vapor-droplet suspensions with droplet evaporation and nonlinear relaxation
Authors: Kandula Max
Published: May 2012

The Sound attenuation and dispersion in saturated gas-vapor-droplet mixture in the presence of evaporation has been investigated theoretically. The theory is based on an extension of the work of Davidson [J. Atmos. Sci. 32(11), 2201–2205 (1975)] to accommodate the effects of nonlinear particle relaxation processes of mass, momentum and energy transfer on sound attenuation and dispersion. The results indicate the existence of a spectral broadening effect in the attenuation coefficient (scaled with respect to the peak value) with a decrease in droplet mass concentration. It is further shown that for large values of the droplet concentration the scaled attenuation coefficient is characterized by a universal spectrum independent of droplet mass concentration.
Vowel enhancement effects in cochlear-implant users
Authors: Wang Ningyuan , Kreft Heather , Oxenham Andrew J.
Published: May 2012

Auditory enhancement of certain frequencies can occur through prior stimulation of surrounding frequency regions. The underlying neural mechanisms are unknown, but may involve stimulus-driven changes in cochlear gain via the medial olivocochlear complex (MOC) efferents. Cochlear implants (CIs) bypass the cochlea and stimulate the auditory nerve directly. If the MOC plays a critical role in enhancement then CI users should not exhibit this effect. Results using vowel stimuli, with and without preceding sounds designed to enhance formants, provided evidence of auditory enhancement in both normal-hearing listeners and CI users, suggesting that vowel enhancement is not mediated solely by cochlear effects.
Influence of a Mannan Binding Family 32 Carbohydrate Binding Module on the Activity of the Appended Mannanase
Authors: Mizutani Kimiya , Fernandes Vânia O. , Karita Shuichi , Luís Ana S. , Sakka Makiko , Kimura Tetsuya , Jackson Adam , Zhang Xiaoyang , Fontes Carlos M. G. A. , Gilbert Harry J. , Sakka Kazuo
Published: May 2012

In general, cellulases and hemicellulases are modular enzymes in which the catalytic domain is appended to one or more noncatalytic carbohydrate binding modules (CBMs). CBMs, by concentrating the parental enzyme at their target polysaccharide, increase the capacity of the catalytic module to bind the substrate, leading to a potentiation in catalysis.
Clostridium thermocellum
hypothetical protein Cthe_0821, defined here as
C. thermocellum
Man5A, is a modular protein comprising an N-terminal signal peptide, a family 5 glycoside hydrolase (GH5) catalytic module, a family 32 CBM (CBM32), and a C-terminal type I dockerin module. Recent proteomic studies revealed that Cthe_0821 is one of the major cellulosomal enzymes when
C. thermocellum
is cultured on cellulose. Here we show that the GH5 catalytic module of Cthe_0821 displays endomannanase activity.
C. thermocellum
Man5A hydrolyzes soluble konjac glucomannan, soluble carob galactomannan, and insoluble ivory nut mannan but does not attack the highly galactosylated mannan from guar gum, suggesting that the enzyme prefers unsubstituted β-1,4-mannoside linkages. The CBM32 of
C. thermocellum
Man5A displays a preference for the nonreducing ends of mannooligosaccharides, although the protein module exhibits measurable affinity for the termini of β-1,4-linked glucooligosaccharides such as cellobiose. CBM32 potentiates the activity of
C. thermocellum
Man5A against insoluble mannans but has no significant effect on the capacity of the enzyme to hydrolyze soluble galactomannans and glucomannans. The product profile of
C. thermocellum
Man5A is affected by the presence of CBM32.
Plasma Membrane Localization Is Required for RasA-Mediated Polarized Morphogenesis and Virulence of Aspergillus fumigatus
Authors: Fortwendel Jarrod R. , Juvvadi Praveen R. , Rogg Luise E. , Asfaw Yohannes G. , Burns Kimberlie A. , Randell Scott H. , Steinbach William J.
Published: May 2012

Ras is a highly conserved GTPase protein that is essential for proper polarized morphogenesis of filamentous fungi. Localization of Ras proteins to the plasma membrane and endomembranes through posttranslational addition of farnesyl and palmitoyl residues is an important mechanism through which cells provide specificity to Ras signal output. Although theAspergillus fumigatusRasA protein is known to be a major regulator of growth and development, the membrane distribution of RasA during polarized morphogenesis and the role of properly localized Ras signaling in virulence of a pathogenic mold remain unknown. Here we demonstrate thatAspergillus fumigatusRasA localizes primarily to the plasma membrane of actively growing hyphae. We show that treatment with the palmitoylation inhibitor 2-bromopalmitate disrupts normal RasA plasma membrane association and decreases hyphal growth. Targeted mutations of the highly conserved RasA palmitoylation motif also mislocalized RasA from the plasma membrane and led to severe hyphal abnormalities, cell wall structural changes, and reduced virulence in murine invasive aspergillosis. Finally, we provide evidence that proper RasA localization is independent of the Ras palmitoyltransferase homolog, encoded byerfB, but requires the palmitoyltransferase complex subunit, encoded byerfD. Our results demonstrate that plasma membrane-associated RasA is critical for polarized morphogenesis, cell wall stability, and virulence inA. fumigatus.
Evaluating workforce developments to support children of mentally ill parents: implementing new interventions in the adult mental healthcare in Northern Norway
Authors: Reedtz Charlotte , Lauritzen Camilla , van Doesum Karin T M
Published: May 2012

Background

According to new Norwegian laws, mental healthcare for adults are obligated to assess all patients who are parents and to act on their children's needs. This article describes the study protocol of implementing the interventions Family Assessment and Child Talks for children of patients in the adult psychiatry of the University Hospital of Northern Norway. The project is designed to evaluate the process of changes in clinical practice due to the implementation of two interventions. The interventions to be implemented are a standardisedFamily Assessment Formand the intervention calledChild Talks. The family assessment form is an intervention to identify children of mentally ill parents and their needs. The interventionChild Talksis a health-promoting and preventive intervention where the mental health workers talk with the family about the situation of the children and their needs.

Methods/design

There are two groups of participants in this study: (1) mental health workers in the clinic (N=220) and (2) patients who are parents (N=200) receiving treatment in the clinic. (1) In the evaluation of clinical practice, the authors use a pre-test, post-test and 1-year follow-up design. At pre-test, the authors evaluate status quo among mental health workers in the clinic regarding knowledge, attitudes, collaborative routines and clinical practice related to families with parental mental illness. After the pre-test is finished, the project move on to implement the interventionsFamily Assessment FormandChild Talksin the clinic. At post-test and 1-year follow-up, the authors evaluate the impact of implementing theFamily Assessment Formin terms of how many children were identified and offered Child Talks in the clinic or referred to other services for additional support. (2) In the evaluation of parents/patients experience with the interventions, the authors use a pre-test post-test design. To identify children of mentally ill patients, the authors collect data on demographical variables for the patient and the child at pre-measures, as well as data on parental competence (PSOC) and parental concerns (PEDS) about their children. At post-measures, the authors evaluate the impact of the intervention in terms of user satisfaction, as well as changes between pre- and post-measures on parental competence (PSOC) and parental concerns (PEDS) about their children.

Discussion

The implication of implementing new interventions to safeguard children of mentally ill patients and the limitation of not measuring child development directly are discussed.
Templates for reporting pre-hospital major incident medical management: systematic literature review
Authors: Fattah Sabina , Rehn Marius , Reierth Eirik , Wisborg Torben
Published: May 2012

Introduction

In 2010, a total of 385 natural disasters killed more than 297 000 people worldwide and affected over 217 million others. More standardised reporting of major incident management have been advocated in the previous years. Prevention, mitigation, preparedness and major incident response may be improved through collection and analysis of high-quality standardised data on medical management of major incidents. Standardised data may elevate the level of scientific evidence within disaster medicine research.

Methods and analysis

A systematic literature review will be conducted to identify templates for reporting pre-hospital major incident medical management. The first set of entry terms aims to describe major incidents published during the last 20 years. The second set aims to focus the number of search results from the first set to those publications that describe templates based on data collections from these major incidents. Predefined free search phases will be combined with the first two sets.

Ethics and dissemination

The results will be submitted for publication in an open access, peer-reviewed scientific journal. The PRISMA checklist will be applied. No ethics approval is considered indicated, as this is a literature review only.

Registration details

This review is registered in PROSPERO (registration number: CRD42012002051).
Loss of SIRT1 histone deacetylase expression associates with tumour progression in colorectal adenocarcinoma
Authors: Jang Si-Hyong , Min Kyeung-Whan , Paik Seung Sam , Jang Ki-Seok
Published: May 2012

Background

The class III histone deacetylase SIRT1 is a nicotinamide adenine dinucleotide (NAD+)-dependent deacetylase, and has been reported to serve diverse roles in various biological processes, such as caloric restriction, apoptosis, neuronal protection, cell growth, differentiation and tumourigenesis. With respect to tumourigenesis, there have been conflicting data supporting whether SIRT1 act as a tumour promoter or as a tumour suppressor.

Methods

SIRT1 protein expression, determined by immunohistochemistry, was investigated in human normal colonic mucosa, adenoma, adenocarcinoma and metastatic tissue samples.

Results

All normal colonic mucosa showed SIRT1 expression with no exception, and 42 (80.8%) of 52 adenomatous polyps were positive for SIRT1. However, only 208 (41.9%) of 497 colorectal adenocarcinomas were positive. Moreover, 45 (35.7%) of 126 metastatic tissues were positive. Collectively, the SIRT1 expression was gradually decreased during carcinogenesis and tumour progression. The associations between SIRT1 expression and clinicopathological parameters revealed that loss of SIRT1 expression was associated with proximal tumour location, mucinous histology and defective mismatch repair protein expression. This suggests that loss of SIRT1 expression is associated with the microsatellite instability phenotype of colorectal adenocarcinoma. In survival analyses, the loss of SIRT1 expression was significantly associated with overall survival (p=0.027, log-rank test) in univariable analysis, but multivariable analysis failed to achieve significance.

Conclusions

SIRT1 expression was gradually decreased during the normal–adenoma–adenocarcinoma–metastasis sequence, suggesting a possible role of SIRT1 in tumour suppression in the colorectum, and a probable link to the microsatellite instability pathway.
Evaluation of a modification of the McKinnon technique to correct urine pooling in mares
Authors: Prado T. M. , Schumacher J. , Kelly G. M. , Henry R. W.
Published: May 2012

The urethral fold of 30 mares was split transversely into dorsal and ventral shelves, and the ventral shelf was used to help create a urethral extension. The dorsal shelf was stretched caudally and sutured to the roof of the extension so that it covered at least the cranial half of the extension. For 20 mares, a relaxing, vaginal incision was created cranial to the external urethral orifice to enable the dorsal shelf to be retracted further caudally. Ten of the 30 mares (33.3 per cent) developed a defect, but none developed a defect in that portion covered by the dorsal shelf of the urethral fold. Two of the 30 mares (6.7 per cent) developed a defect so small that the defect could be detected only by inserting a dye, under pressure, into the tunnel. The total number of mares that developed only a grossly visible and palpable defect was eight of 30 (26.6 per cent). Four of the 10 mares that did not receive the relief incision and six of 20 mares that did receive the relief incision developed a defect in the extension. Modifying the McKinnon technique by transversely splitting the urethral fold and retracting the dorsal half helps prevent a defect from forming in the cranial portion of the extension. The dorsal shelf can be retracted further caudally by creating a relief incision on the floor of the vagina.
Transmission of MRSA CC398 strains between pig farms related by trade of animals
Authors: Espinosa‐Gongora C. , Broens E. M. , Moodley A. , Nielsen J. P. , Guardabassi L.
Published: May 2012

Meticillin‐resistant Staphylococcus aureus (MRSA) clonal complex (CC) 398 is a genetic lineage associated with livestock, especially pigs. The authors investigated the role of pig trade in the transmission of MRSA CC398 between farms using pulsed‐field gel electrophoresis (PFGE), a highly discriminatory method for strain typing. PFGE analysis of 58 MRSA isolates from a retrospective study in the Netherlands and a prospective study in Denmark provided molecular evidence that the strains present in five of the eight recipient farms were indistinguishable from those occurring in the corresponding supplying farm. The molecular typing data confirm the findings of a previous risk‐analysis study indicating that trading of colonised pigs is a vehicle for transmission of MRSA CC398.
Can increases in capillarization explain the early adaptations in metabolic regulation in human muscle to short-term training?
Authors: Green Howard J. , Burnett Margaret , Kollias Helen , Ouyang Jing , Smith Ian , Tupling Susan
Published: May 2012

To investigate the hypothesis that increases in fibre capillary density would precede increases in oxidative potential following training onset, tissue was extracted from the vastus lateralis prior to (0 days) and following 3 and 6 consecutive days of submaximal cycle exercise (2 h·day–1). Participants were untrained males (age = 21.4 ± 0.58 years; peak oxygen consumption = 46.2 ± 1.6 mL·kg–1·min–1; mean ± standard error (SE)). Tissue was assessed for succinic dehydrogenase activity (SDH) by microphotometry and indices of capillarization based on histochemically assessed area and capillary counts (CC) in specific fibre types. Three days of training (n = 13) resulted in a generalized decrease (p < 0.05) in fibre area (–14.2% ± 3.0%; mean ± SE) and increase (p < 0.05) in CC/Area (20.4% ± 2.7%) and no change in either CC or SDH activity. Following 6 days of treatment (n = 6), increases (p < 0.05) in CC (18.2% ± 4.2%), CC/Area (28.9% ± 3.2%), and SDH activity (22.9% ± 6.0%) occurred that was not specific to major fibre type. No changes in either fibre area or fibre-type distribution were observed with additional training. We conclude that increases in angiogenic-based capillary density and oxidative potential occur coincidentally following training onset, while increases in capillary density, mediated by reductions in fibre area, represent an initial isolated response, the significance of which may be linked to the metabolic alterations that also result.
Classical electrical and hydraulic Windkessel models validate physiological calculations of Windkessel (reservoir) pressure
Authors: Sridharan Sarup S. , Burrowes Lindsay M. , Bouwmeester J. Christopher , Wang Jiun-Jr , Shrive Nigel G. , Tyberg John V.
Published: May 2012

Our “reservoir–wave approach” to arterial hemodynamics holds that measured arterial pressure should be considered to be the sum of a volume-related pressure (i.e., reservoir pressure, Preservoir) and a wave-related pressure (Pexcess). Because some have questioned whether Preservoir (and, by extension, Pexcess) is a real component of measured physiological pressure, it was important to demonstrate that Preservoir is implicit in Westerhof’s classical electrical and hydraulic models of the 3-element Windkessel. To test the validity of our Preservoir determinations, we studied a freeware simulation of the electrical model and a benchtop recreation of the hydraulic model, respectively, measuring the voltage and the pressure distal to the proximal resistance. These measurements were then compared with Preservoir, as calculated from physiological data. Thus, the first objective of this study was to demonstrate that respective voltage and pressure changes could be measured that were similar to calculated physiological values of Preservoir. The second objective was to confirm previous predictions with respect to the specific effects of systematically altering proximal resistance, distal resistance, and capacitance. The results of this study validate Preservoir and, thus, the reservoir–wave approach.
Andrographolide exerted its antimicrobial effects by upregulation of human β-defensin-2 induced through p38 MAPK and NF-κB pathway in human lung epithelial cells
Authors: Shao Zhen-Jun , Zheng Xiao-Wei , Feng Ting , Huang Juan , Chen Jian , Wu Yi-Ying , Zhou Li-Ming , Tu Wen-Wei , Li Hong
Published: May 2012

Andrographis paniculata (Burm. f) Nees is a traditional herbal medicine for the treatment of infection and inflammation in China. Andrographolide (andro) is one of the major components. Human β-defensin-2 (hBD-2) is an inducible antimicrobial peptide that plays an important role in innate immunity. The present study aimed to investigate the effect of andro on upregulation of hBD-2 and the key signaling pathways involved in andro-induced hBD-2 expression. Real-time reverse transcription – PCR and Western blot assays showed that andro (1.0–10 µmol/L) can upregulate the expression of hBD-2 in a dose-dependent manner. Further studies suggested that hBD-2 mRNA and protein expression in responsive to andro were attenuated by pretreatment with SB203580 (an inhibitor of p38 mitogen-activated protein kinase (p38 MAPK)), MG-132 (an inhibitor of nuclear factor κB (NF-κB)), and an NF-κB activator inhibitor, but not by an inhibitor of ERK (PD98059) or by an inhibitor of JNK(SP600125). Moreover, we found that a second p38 MAPK inhibitor (SB202190) significantly blocked andro-mediated hBD-2 induction in SPC-A-1 lung epithelial cells. Finally, the p-c-Jun transcription factor activity assay also showed that AP-1 activity was induced by andro compared with the untreated group. We conclude that andro may exert its antimicrobial effects by upregulating the expression of hBD-2 through the p38 MAPK and NF-κB pathway.
Resveratrol protects H9c2 embryonic rat heart derived cells from oxidative stress by inducing autophagy: role of p38 mitogen-activated protein kinase
Authors: Lv Xiao Cui , Zhou Hai Yan
Published: May 2012

Recently, many studies have attempted to illustrate the mechanism of autophagy in protection against oxidative stress to the heart induced by H2O2. However, whether resveratrol-induced autophagy involves the p38 mitogen-activated protein kinase (MAPK) pathway is still unknown. This study aimed to investigate whether treating H9c2 cells with resveratrol increases autophagy and attenuates the cell death and apoptosis induced by oxidative stress via the p38 MAPK pathway. Resveratrol with or without SB202190, an inhibitor of the p38 MAPK pathway, was added 30 min before H2O2. After H2O2 treatment, the cells were incubated under 5% CO2 at 37 °C for 24 h to assess cell survival and death or incubated for 20 min for Western blot and transmission electron microscopy. Flow cytometry was used to detect apoptosis after 6 h of H2O2 treatment. Resveratrol at 20 µmol/L protected H9c2 cells treated with 100 µmol/L H2O2 from oxidative damage. It increased cell survival and markedly decrease lactate dehydrogenase release. In addition, resveratrol increased autophagy and decreased H2O2-induced apoptosis. Furthermore, the protective effects of resveratrol were inhibited by 10 µmol/L SB202190. Thus, resveratrol protected H2O2-treated H9c2 cells by upregulating autophagy via the p38 MAPK pathway.
MASS OF HIGHLY MAGNETIZED WHITE DWARFS EXCEEDING THE CHANDRASEKHAR LIMIT: AN ANALYTICAL VIEW
Authors: KUNDU ARITRA , MUKHOPADHYAY BANIBRATA
Published: May 2012

In recent years a number of white dwarfs have been observed with very high surface magnetic fields. We can expect that the magnetic field in the core of these stars would be much higher (~1014 G ). In this paper, we analytically study the effect of high magnetic field on relativistic cold electron, and hence its effect on the stability and the mass–radius relation of a magnetic white dwarf. In strong magnetic fields, the equation of state of the Fermi gas is modified and Landau quantization comes into play. For relatively very high magnetic fields (with respect to the average energy density of matter) the number of Landau levels is restricted to one or two. We analyze the equation of states for magnetized electron degenerate gas analytically and attempt to understand the conditions in which transitions from the zeroth Landau level to first Landau level occurs. We also find the effect of the strong magnetic field on the star collapsing to a white dwarf, and the mass–radius relation of the resulting star. We obtain an interesting theoretical result that it is possible to have white dwarfs with mass more than the mass set by Chandrasekhar limit.
A SYSTEM TO REASON ABOUT UNCERTAIN AND DYNAMIC ENVIRONMENTS
Authors: LU ZHIRUI , AUGUSTO JUAN , LIU JUN , WANG HUI , AZTIRIA ASIER
Published: May 2012

Decision-making on uncertain and dynamic domains is still a challenging research area. This paper explores a solution to handle such complex decision making based on a combined logic system. We provide an explanation of our reasoning system focused on the algorithms and their implementations. The reasoning system is based on a multi-valued temporal propositional logic which we use as the foundation for the implementation of simulation/prediction and query answering tools. This system is available for users to represent knowledge and to refine these systems to debug them and to try different problem solving strategies. We provide examples to illustrate how the system can be used including a problem based on a real smart environment.
EFFICIENT MINING OF CLOSED TREE PATTERNS FROM LARGE TREE DATABASES WITH SUBTREE CONSTRAINT
Authors: NGUYEN VIET ANH , DOI KOICHIRO , YAMAMOTO AKIHIRO
Published: May 2012

Mining frequent tree patterns from tree databases has practical importance in domains like Web mining, Bioinformatics, and so on. Although there have been algorithms on efficient tree mining, these algorithms are often lack of the interpretability in that they often produce a huge number of patterns, most of which are meaningless to users. This paper aims at both demands, one with respect to computational cost, which is efficient generation of tree patterns, and another one with respect to the interpretability. This task requires an efficient method to incorporate the users' needs into mining process.

We propose a new top-down method for mining unordered closed tree patterns from a database of trees such that every mined pattern must contain a common piece of information in the form of a tree specified by the user. This type of mining is called mining with subtree constraint which would be useful, for example, inWeb mining and Bioinformatics, where users want to extract common patterns around some given information from original data. The proposed algorithm is tested and compared with a state-of-the-art tree mining algorithm on real and artificial datasets with very good results.
THE INTERFACE BETWEEN THE NORMAL STATE AND THE FULLY SUPERCONDUCTING STATE IN THE PRESENCE OF AN ELECTRIC CURRENT
Authors: ALMOG Y.
Published: May 2012

We consider the time-dependent Ginzburg–Landau equations, in the presence of electric current and the absence of magnetic field. We first study one-dimensional equilibrium solutions on a semi-infinite domain, describing a layer of transition from the normal state at one edge to the fully superconducting state at infinity. We find that the normal conductivity has a significant effect on the maximal current that can pass through such a transition layer. The global stability of the purely superconducting state in a finite domain is also considered, assuming zero potential drop between the conducting surfaces.
THE NICHOLS ALGEBRA OF SCREENINGS
Authors: SEMIKHATOV A. M. , TIPUNIN I. YU.
Published: May 2012

Two related constructions are associated with screening operators in models of two-dimensional conformal field theory. One is a local system constructed in terms of the braided vector space X spanned by the screening species in a given CFT model and the space of vertex operators Y and the other is the Nichols algebra 𝔅(X) and the category of its Yetter–Drinfeld modules, which we propose as an algebraic counterpart, in a "braided" version of the Kazhdan–Lusztig duality, of the representation category of vertex-operator algebras realized in logarithmic CFT models.
ON d-DIGIT PALINDROMES IN DIFFERENT BASES: THE NUMBER OF BASES IS UNBOUNDED
Authors: BAŠIĆ BOJAN
Published: May 2012

The following problem was posed in [E. H. Goins, Palindromes in different bases: A conjecture of J. Ernest Wilkins, Integers 9 (2009) 725–734]: "What is the largest list of bases b for which an integer N ≥ 10 is a d-digit palindrome base b for every base in the list?" We show that it is possible to construct such a list as large as we please. Furthermore, we show that it is possible to construct such arbitrarily large list for any given d.
A NOTE ON CONTROL THEOREMS FOR QUATERNIONIC HIDA FAMILIES OF MODULAR FORMS
Authors: LONGO MATTEO , VIGNI STEFANO
Published: May 2012

We extend a result of Greenberg and Stevens on the interpolation of modular symbols in Hida families to the context of non-split rational quaternion algebras. Both the definite case and the indefinite case are considered.
ON THE DISTRIBUTION OF CYCLIC NUMBER FIELDS OF PRIME DEGREE
Authors: LEE SEOK HYEONG , OH GYUJIN
Published: May 2012

Let NCp(X) denote the number of Cp Galois extensions of ℚ with absolute discriminant ≤ X. A well-known theorem of Wright [Density of discriminants of abelian extensions, Proc. London Math. Soc. 58 (1989) 17–50] implies that when p is prime, we have [Formula: see text] for some positive real c(p). In this paper, we improve this result by reducing the secondary error term to [Formula: see text]. Moreover, under Generalized Riemann Hypothesis, we obtain the following stronger result [Formula: see text] Here Rp(x) ∈ ℝ[x] is a polynomial of degree ⌊p(p-2)/3⌋-1. This confirms a speculation of Cohen, Diaz y Diaz and Olivier [Counting discriminants of number fields, J. Théor. Nombres Bordeaux 18 (2006) 573–593] in the case of C3 extensions.
LOCAL HEIGHTS ON ELLIPTIC CURVES AND INTERSECTION MULTIPLICITIES
Authors: BUSCH VINCENZ , MÜLLER JAN STEFFEN
Published: May 2012

In this short note we prove a formula for local heights on elliptic curves over number fields in terms of intersection theory on a regular model over the ring of integers.
SPACES OF MODULAR FORMS AND ALGEBRAIC GEOMETRIC CODES
Authors: MAHARAJ HIREN
Published: May 2012

For ℓ = 2, 3, 5, we show that spaces of modular forms M2k(Γ0(ℓn)) are closely related to a class of one-point codes from the reduction of the modular tower {X0(ℓn)}n≥2 (mod p) for primes p > ℓ. Code construction from the space of cusp form is also considered.
ON PRIME FACTORS OF ODD PERFECT NUMBERS
Authors: ACQUAAH PETER , KONYAGIN SERGEI
Published: May 2012

We prove that a prime factor q of an odd perfect number x satisfies the inequality q < (3x)1/3.
Mass Transport Processes in the Electro-Oxidation of Organic Compounds for Wastewater Treatment
Authors: Ni Qing , Kirk Donald W. , Thorpe Steven J.
Published: May 2012

The mass transport of species, including diffusion, convection and migration, involved in the electro-oxidation of oxalic acid was investigated. A rotating-disk electrode technique was used as a tool to investigate the influence of convection. The effect of pH and potential on the degradation rate of oxalic acid was also investigated by measuring oxalic acid oxidation over the pH range 0 to 7 and potential 1.6 to 2.4 vs. Ag/AgCl. The results showed that higher degradation rates were achieved by increasing the convection, using higher pH and E. The results also showed that the local pH at the electrode surface had a significant impact on electrolysis in a neutral non-buffered solution.
Gold Extraction from an Oxide Ore in Iodine-Iodide Solutions
Authors: Baghalha Morteza
Published: May 2012

Two types of gold ores were subjected to iodide/iodine leaching at room temperature. The effects of three factors, including ore type (a carbonaceous and an oxide gold ores), iodide/iodine concentration, and the presence of oxygen in solution on gold leaching performance were investigated. The carbonaceous ore showed only 20% gold extraction into the solution; since gold-iodide complexes would readily adsorb on organic matter. In contrast, gold extraction from the oxide ore in a solution containing 20 g/L iodide and 4 g/L iodine reached 77% in 6 h and 89% in 24 h. With iodate as the oxidant, no gold could be leached in 48 hours. When the iodate was partially converted to iodine by adding HCl to the solution, gold leaching was then started. Iodine reactions with the sulfide and ferrous minerals of the oxide ore slowly consumed iodine within 48 hours.
Effects of Anode and Cathode Areas on Organic Compounds Removal and Power Generation in Membraneless Microbial Fuel Cell (MFC)
Authors: Santoro Carlo , Cristiani Pierangela , Agrios Alexander G. , Li Baikun
Published: May 2012

This study focused on the effects of anode and cathode area on power generation and wastewater treatment in membraneless air-cathode single chamber microbial fuel cells (SCMFCs). The results showed that the power generation of the SCMFCs did not vary with anode area, while the power generation slightly increased with cathode area. Specifically, the power generation increased 10-16% (from 230-236 μW to 265-276 μW) when the cathode area increased from 1.25 to 10 cm2. The COD degradation efficiency increased slightly (10-15%) with anode area, and substantially (more than 50%) with cathode area. The increase in cathode area led to a higher power generation and higher wastewater treatment efficiency in MFCs.
Fabrication Process for Electromagnetic Actuators Compatible with Polymer Based Microfluidic Devices
Authors: Rahbar Mona , Seyfollahi Sam , Khosla Ajit , Gray Bonnie L. , Shannon Lesley
Published: May 2012

We demonstrate a new hybrid-soft-lithography micromolding process that results in a mechanically-compliant, magnetically actuated membrane. The new microactuator consists of a thin undoped polydimethylsiloxane (PDMS) membrane with a central magnet feature, which is also micromolded using soft lithography. The central magnet is composed of a magnetic nanocomposite polymer (M-NCP) material, which is achieved by uniformly dispersing rare earth magnetic powder (MQP-12-5) in the PDMS polymer matrix. The hybrid fabrication technique is capable of realizing a highly flexible membrane with the ability of providing bidirectional deflection without sacrificing the transparency of the device, which may be required for many biomedical applications. Furthermore, we show that the hybrid process also yields improved deflection of the membrane using lower magnetic fields than an opaque membrane fabricated entirely in nanocomposite polymer. These lower fields are more suitable to on-chip production of microactuators excited via electronic signals in microcoils.
Micromachined Nickel Floating Element Shear Stress Sensor Array
Authors: Zhao Zhengxin , Gallman Judith , White Robert
Published: May 2012

This paper describes the design, fabrication, characterization and packaging of a 256 element MEMS floating element shear stress sensor array-on-a-chip. This device is targeted at measuring time resolved fine spatial scale shear stress beneath the turbulent boundary layer (TBL) for aerospace applications. The differential measurement shows a sensitivity of 0.08 mV/Pa at 0.27 mV/ . The linear ranges are observed up to 3.6 Pa and 6 Pa respectively for 3μm and 10 μm-thick structure.
Oxygen Detection Using Different Types of Membranes Deposited on Needle Based Platforms
Authors: Anastasova Salzitsa , Spehar-Délèze Anna-Maria , Vadgama Pankaj
Published: May 2012

The aim of this work was to develop needle based sensors for oxygen sensing using different types of membranes. For oxygen sensors it is important to achieve fast response time, good linearity, low biofouling and high sensitivity. The effect of different types of polymeric barrier membranes and their various combinations were assessed and compared. An optimized system was thereby selected: sensors covered with polyurethane membrane doped with surfactant showed good stability with a linear working range up to 750 mmHg pO2.
Effects of SAW Propagation with Electrochemical Deposition of Ge Film on LiNbO3 Substrate
Authors: Kaneshiro Chinami , Gushiken Rimiko
Published: May 2012

We present the results of a basic study on surface acoustic wave (SAW) propagation characteristics with electrochemical deposition of Ge thin films for functional devices. We investigated forming Ge film on the SAW propagation path by using electrochemical deposition as a new process approach. Energy-dispersive X-ray spectroscopy (EDX) analysis of deposited particles indicated that the electrochemical deposition of Ge was successfully achieved by applying pulse-potential to the working electrode. The experimental results of the fabricated device show that the SAW propagation characteristics of LiNbO3 with Ge has a frequency shift toward a higher range due to the change in the mass-loading of SAW propagation after Ge deposition. These experimental results indicate the potential use for functional devices.
Effect of Temperature and Impurities on the AISI 316L/Microplasma Arc Welded AISI 316L Galvanic Pair in H3PO4 under Flowing Conditions
Authors: Sánchez-Tovar Rita , Montañés Maria Teresa , García-Antón José , Guenbour Abdellah
Published: May 2012

This work studies the influence of temperature (25, 40 and 60 °C) on the corrosion behavior of base and welded AISI 316L stainless steels in phosphoric acid polluted by sulfuric acid and chloride ions under hydrodynamic conditions (Reynolds number = 1456). Galvanic corrosion is studied by means of the mixed potential theory. The effects of impurities on corrosion and galvanic corrosion rates are considered. Results show that, in polluted acid, the heat treatment due to the welding technique affects on the AISI 316L stainless steel increasing the corrosion current densities. On the other hand, temperature and impurities increase corrosion and galvanic corrosion rates. The galvanic effect of the base/welded pair in polluted phosphoric acid was neither significant nor severe.
In Situ Study of Corrosion Evolution of Alloy 926 (UNS N08926) in its Unsensitized and Sensitized State in LiBr Solutions Using Confocal Laser Scanning Microscopy
Authors: Leiva-García Rafael , Muñoz-Portero M. José , García-Antón José
Published: May 2012

The aim of this work is to study the corrosion evolution of a unsensitised and sensitised stainless steel in a 992 g/l LiBr solution. The tested material has been a highly alloyed austenitic stainless steel (UNS N08926) in its as-received state and heated at 825 ºC for 1 hour in an inert atmosphere. Tests have been carried out in an electrochemical minicell that can be put in the stage of a confocal microscope. Differences in the evolution of morphology attack have been observed between the unsensitised and sensitised samples. The used technique has demonstrated to be very useful to check differences in the evolution of corrosion processes.
Investigation of Electroreduction Kinetics of the Hexaamminecobalt(III) Cations on the Electrochemically Polished Bi Planes by the Electrochemical Impedance Spectroscopy Method
Authors: Härk Eneli , Lust Enn
Published: May 2012

Electrochemical impedance spectroscopy has been used for investigation of electroreduction kinetics of hexaamminecobalt(III) cations on the electrochemically polished Bi planes. The total charge transfer resistance obtained depends noticeably on the electrode potential and [Co(NH3)6]3+ concentration. Systematic analysis of results show that the equivalent circuit taking into account the adsorption of one reacting or intermediate particle is the more probable and simplest physical model of the complicated [Co(NH3)6]3+ electroreduction reaction under discussion. The charge transfer resistance, adsorption capacitance and adsorption resistance values depend on the electrode potential as well as on the reactant concentration. In the base electrolyte solution with addition of [Co(NH3)6]3+ the adsorption and charge transfer resistance value was maximal and the adsorption capacitance value was minimal in the region of zero charge potential for Bi single crystal (111) and (011-) planes.
Phase Behavior and Solvation of Lithium Triflate in Ethylene Carbonate
Authors: Foley Matthew P. , Seo Daniel M. , Worosz Christopher J. , Boyle Paul D. , Henderson Wesley A. , De Long H. C. , Trulove P. C.
Published: May 2012

Presented here are data describing the phase behavior and solvation of lithium trifluoromethanesulfonate (LiTf) in ethylene carbonate (EC). Data obtained from differential scanning calorimetry (DSC), Raman spectroscopy, and X-ray diffraction analyses of sample mixtures are correlated to enhance understanding of solvent-salt associations. Thermal analysis by DSC is converted into a binary phase diagram describing the behavior of the solvent-salt interactions. Raman spectroscopy is applied to probe the liquid electrolyte and discover solvent-salt associations in solution. X-ray crystallography reveals that EC-LiTf form a 1:1 aggregated solvate. Raman spectroscopic analysis of mixtures reveals the presence of two aggregated solvates and one contact ion pair.
Single-Frequency LCR Databridge Impedance Measurements as Surrogate Measures for the Integrity of Human Skin
Authors: White Erick A. , Orazem Mark E. , Bunge Annette L.
Published: May 2012

While LCR databridge instruments are used to probe the integrity of skin, there is confusion in this literature about what these instruments report in series (SER) or parallel (PAR) modes at user-specified measurement frequencies, typically 100 or 1,000 Hz. Here, the theoretical meanings of resistance and capacitance measurements in PAR and SER mode are presented. A large body of data from human cadaver skin are used to show that LCR databridge resistance measured at 100 Hz in PAR mode and capacitance measured at 100 Hz in SER mode are most sensitive to skin resistivity, which is the electrical measurement most closely related to skin integrity. The single-frequency databridge resistance values are shown to correlate to skin permeability measurements using tritiated water.
NiMH Supercapacitor Design, Modeling and HEV Applications
Authors: Song Li J. , Chen Feng , Mehrotra Vikas
Published: May 2012

NiMH batteries are being used in hybrid electrical vehicles (HEVs) with demonstrated safety, reliability and cost-effectiveness. Nevertheless, the lack of specific power of the battery restricts its wide adoption. In this study, a NiMH battery based supercapacitor (Ni-Cap) is designed specifically to be charged and discharged at very high rates up to 20C, delivering high specific power (3000W/kg) and energy (38.5Wh/kg). Various tests show that the Ni-cap holds energy well, has a long cycle time, a wide operating window and is tolerant to abusive conditions. The Ni-cap is suitable for HEV or micro-hybrid (stop and start system) energy storage applications.
Preparation of High Surface Area Nano-Structured Graphene Composites
Authors: Wang Mei-xian , Liu Qi , Sun Hong-fang , Stach Eric A. , Xie Jian
Published: May 2012

The single-layer graphene usually aggregates and form irreversible multilayer graphene sheets due to the Van Der Waals interaction between the neighboring sheets, and the agglomeration leads to a substantial loss of effective surface area for graphene in the solid state. This affects the graphene's applications where high surface area is the prerequisite. Therefore, the creation of intrinsically ultrahigh surface area graphene in the solid state is paramount significance. In this work, the functionalized hydrophilic carbons were used as the spacer for the preparation of the graphene composites, and the surface area can reach as high as 1256 m2/g with 1 % content of functionalized carbon blacks. A specific capacitance of as high as 324.6 F/g at a current density of 0.3 A/g was achieved over the graphene composites.