bluuebunny/crossref_metadata_2025 huggingface dataset:
Executive Summary: Clinical Practice Guideline for the Use of Antimicrobial Agents in Neutropenic Patients with Cancer: 2010 Update by the Infectious Diseases Society of America
Authors: Freifeld Alison G. , Bow Eric J. , Sepkowitz Kent A. , Boeckh Michael J. , Ito James I. , Mullen Craig A. , Raad Issam I. , Rolston Kenneth V. , Young Jo-Anne H. , Wingard John R.
Published: January 2011

This document updates and expands the initial Infectious Diseases Society of America (IDSA) Fever and Neutropenia Guideline that was published in 1997 and first updated in 2002. It is intended as a guide for the use of antimicrobial agents in managing patients with cancer who experience chemotherapy-induced fever and neutropenia.

Recent advances in antimicrobial drug development and technology, clinical trial results, and extensive clinical experience have informed the approaches and recommendations herein. Because the previous iteration of this guideline in 2002, we have a developed a clearer definition of which populations of patients with cancer may benefit most from antibiotic, antifungal, and antiviral prophylaxis. Furthermore, categorizing neutropenic patients as being at high risk or low risk for infection according to presenting signs and symptoms, underlying cancer, type of therapy, and medical comorbidities has become essential to the treatment algorithm. Risk stratification is a recommended starting point for managing patients with fever and neutropenia. In addition, earlier detection of invasive fungal infections has led to debate regarding optimal use of empirical or preemptive antifungal therapy, although algorithms are still evolving.

What has not changed is the indication for immediate empirical antibiotic therapy. It remains true that all patients who present with fever and neutropenia should be treated swiftly and broadly with antibiotics to treat both gram-positive and gram-negative pathogens.

Finally, we note that all Panel members are from institutions in the United States or Canada; thus, these guidelines were developed in the context of North American practices. Some recommendations may not be as applicable outside of North America, in areas where differences in available antibiotics, in the predominant pathogens, and/or in health care–associated economic conditions exist. Regardless of venue, clinical vigilance and immediate treatment are the universal keys to managing neutropenic patients with fever and/or infection.
Review article: the functional abdominal pain syndrome
Authors: Sperber A. D. , Drossman D. A.
Published: January 2011

Aliment Pharmacol Ther 2011; 33: 514–524

Background  Functional abdominal pain syndrome (FAPS) is a debilitating disorder with constant or nearly constant abdominal pain, present for at least 6 months and loss of daily functioning.

Aim  To review the epidemiology, pathophysiology and treatment of FAPS.

Methods  A literature review using the keywords: functional abdominal pain, chronic abdominal pain, irritable bowel syndrome and functional gastrointestinal disorders.

Results  No epidemiological studies have focused specifically on FAPS. Estimates of prevalence range from 0.5% to 1.7% and tend to show a female predominance. FAPS pathophysiology appears unique in that the pain is caused primarily by amplified central perception of normal visceral input, rather than by enhanced peripheral stimulation from abdominal viscera. The diagnosis of FAPS is symptom‐based in accordance with the Rome III diagnostic criteria. These criteria are geared to identify patients with severe symptoms as they require constant or nearly constant abdominal pain with loss of daily function and are differentiated from IBS based on their non‐association with changes in bowel habit, eating or other gut‐related events. As cure is not feasible, the aims of treatment are reduced suffering and improved quality of life. Treatment is based on a biopsychosocial approach with a therapeutic patient–physician partnership at its base. Therapeutic options include central nonpharmacological and pharmacological modalities and peripheral modalities. These can be combined to produce an augmentation effect.

Conclusion  Although few studies have assessed functional abdominal pain syndrome or its treatment specifically, the treatment strategies outlined in this paper appear to be effective.
Research on person‐centred clinical care
Authors: Finset Arnstein
Published: January 2011

Rationale, aims and objectives  To give a selective review of empirical studies on person‐centred clinical care, in particular concerning communication patterns between patients and providers.

Methods  Descriptive and selective review of relevant literature.

Results  Person‐centred clinical care may have positive effects on patient satisfaction, patient adherence, health care utilization, malpractice litigation and health outcome. Person‐centred communication skills may be promoted by way of communication skills training.

Conclusion  The concept of person‐centred care is rare in the empirical literature. Future research should operationalize the concept and design studies of the impact of patient‐centred clinical care.
A bacterial dynamin‐like protein mediating nucleotide‐independent membrane fusion
Authors: Bürmann Frank , Ebert Nina , van Baarle Suey , Bramkamp Marc
Published: January 2011

Dynamins are a family of large GTPases that are involved in key cellular processes, where they mediate events of membrane fission and fusion. The dynamin superfamily is not restricted to eukaryotes but might have a bacterial origin, with many species containing an operon of two genes related to mitofusins. However, it is not clear whether bacterial dynamins promote membrane fission or fusion. The dynamin‐like protein DynA of Bacillus subtilis is remarkable in that it arose from a gene fusion of two dynamins and contains two separate dynamin‐like subunits and GTPase domains. We found that DynA exhibits strictly auto‐regulated GTP hydrolysis, and that progress through the GTPase cycle is concerted within DynA oligomers. Furthermore, we show that DynA can tether membranes and mediates nucleotide‐independent membrane fusion in vitro. This process merely requires magnesium as a cofactor. Our results provide a set of minimal requirements for membrane fusion by dynamin‐like proteins and have mechanistic implications in particular for the fusion of mitochondria.
Negotiating Difference through Everyday Encounters: The Case of Sexual Orientation and Religion and Belief
Authors: Valentine Gill , Waite Louise
Published: January 2011

Abstract:  This paper argues for geographers to be more attentive to the potentially competing values, interests, and rights of the equality strands (race, gender, disability, religion and belief, sexual orientation, age). We focus on two that are most commonly assumed to experience tensions: religion/belief and sexual orientation. Drawing on focus groups with heterosexual Christians, Jews, Muslims, and Hindus and lesbian and gay people of faith we explore the attitudes of heterosexual people of faith towards homosexuality. These findings suggest that tensions should be emerging between these groups in public space. However, we then demonstrate that these anticipated conflicts are not emerging because of the strategies people employ for separating their beliefs from their everyday conduct. In such ways, our findings demonstrate how the “what is” (ie personal experience) for both heterosexual and lesbian and gay people of faith is prioritised over theological or institutional perspectives of “what ought to be”.
Limited Utility of Exercise‐Stress Testing to Prevent T‐Wave Oversensing in Pediatric Internal Cardioverter Defibrillator Recipients
Authors: COHEN MITCHELL I. , SHAFFER JENNIFER , PEDERSEN SCOTT , SIMS J. JASON , PAPEZ ANDREW
Published: January 2011

Background: Inappropriate internal cardioverter defibrillator (ICD) therapies may result from T‐wave oversensing (TWOS) during exertion in children. The aim of this study was to evaluate the utility of an exercise treadmill test to predict inappropriate ICD therapies secondary to TWOS.

Methods: Eligible pediatric ICD recipients underwent exercise‐stress testing with concomitant evaluation of all intracardiac electrograms. Double counting at a programmed sensitivity of 0.3 mV was considered indicative of TWOS. Patients were prospectively followed for 2 years and censored at either the development of an inappropriate ICD therapy secondary to TWOS or at the time of ICD revision.

Results: Nineteen patients (age: 13.8 ± 3.2 years) underwent exercise testing (median time from ICD implant: 1.5 years, range 2–4.3 years). Two patients were identified with TWOS during the stress test and had a clinically inappropriate ICD discharge within 2 weeks despite a sensitivity adjustment to 0.6 mV. One individual had an inappropriate ICD discharge from TWOS 11 months following an initial uneventful exercise‐stress test.

Conclusions: Inappropriate ICD therapies from TWOS relate to a reduction in the intrinsic R wave or augmentation of the T wave during exertion. While intracardiac electrogram assessment during stress testing may aid in the early recognition of TWOS, it did not absolutely translate to a reduction in the incidence of inappropriate ICD shocks. (PACE 2011; 34:436–442)
Different Image Integration Modalities to Guide AF Ablation: Impact on Procedural and Fluoroscopy Times
Authors: PRATOLA CLAUDIO , BALDO ELISA , ARTALE PAOLO , MARCANTONI LINA , TOSELLI TIZIANO , PERCOCO GIANFRANCO , SASSONE BIAGIO , FERRARI ROBERTO
Published: January 2011

Background: Different image integration modalities are available for atrial fibrillation (AF) ablation, but their impact on procedural and fluoroscopy times has not been evaluated yet.

Methods: Sixty patients (mean age 52.2 ± 12.0 years, 48.3% men, 75% paroxysmal AF) undergoing pulmonary vein (PV) encircling with PV disconnection for symptomatic drug‐refractory AF were randomized to ablation with CARTO electroanatomical mapping (Biosense Webster, Diamond Bar, CA, USA) integrated with: (1) preprocedural magnetic resonance imaging (MRI; Group 1); (2) intracardiac echocardiography (ICE; Group 2); (3) preprocedural MRI and ICE (Group 3).

Results: PV disconnection was achieved in all patients. Total procedural time (Group 1: 124.7 ± 47.0; Group 2: 112.5 ± 30.4; Group 3: 108.6 ± 34.7 minutes) and total ablation time were similar between groups (P = ns). MRI integration alone required a higher fluoroscopy time (23.8 ± 6.9 in Group 1 vs 11.0 ± 2.3 and 13.9 ± 4.2 minutes in Groups 2 and 3, respectively; P < 0.005) and a longer time spent in the left atrium (109.0 ± 43.5 in Group 1 vs 78.2 ± 29.7 and 74.8 ± 34.3 minutes in Groups 2 and 3, respectively; P = 0.03) in comparison to ICE integration. Addition of MRI to ICE integration showed a tendency for a higher fluoroscopy time in comparison to ICE integration alone (P = 0.06). At a mean follow‐up of 9.1 ± 2.2 months, there were no significant differences in AF recurrences among the groups (P = ns).

Conclusion: ICE image integration significantly reduces the fluoroscopy time and the time spent in the left atrium in comparison to MRI integration alone. Addition of MRI to ICE integration does not reduce total procedural time and seems to lead to higher fluoroscopy time in comparison to ICE integration alone. (PACE 2011; 34:422–430)
Delayed ICD Lead Cardiac Perforation: Comparison of Small versus Standard‐Diameter Leads Implanted in a Single Center
Authors: RORDORF ROBERTO , CANEVESE FABIO , VICENTINI ALESSANDRO , PETRACCI BARBARA , SAVASTANO SIMONE , SANZO ANTONIO , GANDOLFI EDOARDO , DORE ROBERTO , LANDOLINA MAURIZIO
Published: January 2011

Background: An increased risk of delayed cardiac perforation (DCP) with active‐fixation small‐diameter ICD leads has recently been reported, especially with regard to the St. Jude Riata lead (St. Jude Medical, Sylmar, CA, USA). Few data on the risk of DCP in small versus standard‐diameter leads implanted in a single high‐volume center are available. Moreover, no data on the performances of St. Jude's new small‐diameter Durata lead are as yet available.

The aim of this study was to assess the incidence of DCP in small versus standard‐diameter leads implanted in our center.

Methods: Between January 2003 and October 2009, 437 small‐diameter leads (190 Medtronic Sprint Fidelis [Medtronic Inc., Minneapolis, MN, USA], 196 Riata, 51 Durata) and 421 standard‐diameter (>8 Fr) leads were implanted.

Results: After a median follow‐up of 421 days seven of 858 (0.8%) patients experienced DCP. The incidence of DCP was higher in patients with small‐diameter leads than in those with standard‐diameter leads (1.6% vs 0%, P = 0.01). No cases of DCP occurred among 371 passive‐fixation leads versus 1.4% of events among active‐fixation leads (P = 0.02). The incidence of DCP was 2.5% in Riata, 1% in Sprint Fidelis, 0% in Durata, and 0% in standard‐diameter leads (P < 0.01 for Riata vs standard‐diameter leads).

Conclusions: Small‐diameter active‐fixation ICD leads are at increased risk of DCP, a finding mostly due to the higher incidence of events in the Riata family. By contrast, passive‐fixation small‐diameter leads and standard‐diameter leads appear to be safe enough regarding the risk of DCP. Our preliminary data suggest that the new Durata lead is not associated with an increased risk of DCP. (PACE 2011; 34:475–483)
Long‐term Outcome Following Ablation of Atrial Flutter Occurring Late after Atrial Septal Defect Repair
Authors: TEH ANDREW W. , MEDI CAROLINE , LEE GEOFFREY , ROSSO RAPHAEL , SPARKS PAUL B. , MORTON JOSEPH B. , KISTLER PETER M. , HALLORAN KAREN , VOHRA JITENDRA K. , KALMAN JONATHAN M.
Published: January 2011

Aims: In patients with surgical atrial septal defect (ASD) repair, late atrial flutters (AFLs), including cavotricuspid isthmus (CTI)‐dependent and non‐CTI‐dependent scar‐related flutter (AFL), are common. Radiofrequency ablation (RFA) of these arrhythmias has a high acute success rate. We aimed to characterize the long‐term freedom from atrial arrhythmias in this population.

Methods: Twenty consecutive patients undergoing RFA for AFL late after ASD repair were included. Electrophysiological assessment included multipolar activation, entrainment, and electroanatomic mapping. Clinical, electrocardiograph, and Holter monitoring follow‐up was conducted every 6 months.

Results: Mean age was 53 ± 13 years. Time from surgical repair to RFA was 29 ± 15 years. All patients had CTI‐dependent AFL (20/20). There were 1.6 ± 0.7 arrhythmias per patient; other arrhythmias included non‐CTI‐dependent AFL (14), focal atrial tachycardia (two), and atrioventricular nodal reentry tachycardia (two)
. Acute success was obtained in 100%. Five patients with recurrent AFL (three CTI dependent, two non‐CTI dependent) at 13 ± 8 months had successful repeat RFA. At 3.2 ± 1.6 years follow‐up since the last procedure, 90% of patients with successful RFA for AFL remained free of their clinical arrhythmia. However, 30% of the original 20 patients had documented atrial fibrillation (AF) 2.1 ± 1.6 years after the last procedure; five (25%) required AF intervention. One stroke (5%) occurred in the context of late AF.

Conclusion: RFA of AFL occurring late after surgical ASD repair has a low long‐term risk of recurrence, although 25% of patients required two procedures. However, there is a high late incidence of AF (30%), with an additional 25% of patients requiring intervention for AF. (PACE 2011; 34:431–435)
‘Better Wear Out Sheets than Shoes’: A Survey of 202 Stroke Professionals' Early Mobilisation Practices and Concerns
Authors: Skarin Monica , Bernhardt Julie , Sjöholm Anna , Nilsson Michael , Linden Thomas
Published: January 2011

Background

Stroke unit care improves the outcome for patients. One component responsible for this may be that patients are mobilised earlier and more intensively. An ongoing randomised controlled trial is investigating the potential benefits of early mobilisation, but currently there is limited evidence for the practice. Therefore, current practices may be driven by historical precedent and/or clinical opinion, and varying approaches to mobilisation are likely. This study aims to examine different health professionals' concerns regarding early mobilisation in acute stroke. In this study, early mobilisation was defined as frequent out of bed activities within the first 24 h after stroke onset.

Methods

A nine-item anonymous questionnaire exploring benefits and harms with early mobilisation after stroke was used during interviews of stroke care professionals attending the annual Australasian stroke conference in 2008.

Results

The survey was completed by 202 professionals, representing 38% of all conference attendees. Sixty-five per cent were females, 50% under 40-years old, 46% worked in acute stroke and 31% in rehabilitation. Thirty-five per cent were nurses, 26% medical doctors, 19% physiotherapists and 12% occupational therapists. Two-thirds had <10-years experience with stroke. Sixty per cent of the surveyed professionals had concerns about early mobilisation and there were significantly more professionals concerned about early mobilisation for haemorrhagic (59%) than ischaemic (23%) stroke patients.

Conclusion

Our study shows that most clinicians had concerns in relation to early mobilisation of stroke patients and more clinicians had concerns for haemorrhagic than for ischaemic stroke. The evidence underlying these concerns is shallow.
Effect of Clopidogrel plus ASA vs. ASA Early after TIA and Ischaemic Stroke: A Substudy of the CHARISMA Trial
Authors: Hankey Graeme J. , Johnston S. Claiborne , Easton J. Donald , Hacke Werner , Mas Jean-Louis , Brennan Danielle , Mak Koon Hou , Bhatt Deepak L. , Fox Keith A. A. , Topol Eric J. ,   on behalf of the CHARISMA trial investigators
Published: January 2011

Background

The Clopidogrel for High Atherothrombotic Risk and Ischaemic Stabilisation, Management and Avoidance (CHARISMA) trial reported no statistically significant benefit of adding clopidogrel to acetylsalicylic acid in the long-term management of a broad population of patients with stable vascular disease. However, a subanalysis raised the hypothesis that dual antiplatelet therapy with clopidogrel plus acetylsalicylic acid may be more effective than aspirin in patients with prior ischaemic stroke, myocardial infarction of symptomatic peripheral arterial disease. We aimed to determine whether the possible benefits of clopidogrel plus acetylsalicylic acid in patients with transient ischaemic attack and ischaemic stroke may be ‘front-loaded’, and maximal within the first 30-days of randomisation, without being unduly hazardous.

Methods

This was a subanalysis of a randomised, double-blind, placebo-controlled trial of clopidogrel vs. placebo, in addition to background therapy with low-dose acetylsalicylic acid (CHARISMA trial), restricted to all patients with transient ischaemic attack or ischaemic stroke. The primary efficacy outcome was stroke, and safety outcome severe bleeding, during the follow-up period.

Results

Among all transient ischaemic attack and ischaemic stroke patients randomised to placebo ( n=2163), 131 (6·1%) experienced a stroke during follow-up compared with 105 (4·9%) of 2157 patients assigned clopidogrel (hazard ratio: 0·80, 95% confidence intervals: 0·62–1·03). There was no significant difference in severe bleeding (1·7% placebo vs. 1·9% clopidogrel, hazard ratio: 1·11, 95% confidence intervals: 0·71–1·73). Among all patients randomised within 30-days of their qualifying transient ischaemic attack or ischaemic stroke to placebo ( n=667), 46 (6·9%) experienced a stroke compared with 34 (5·1%) of 664 patients assigned clopidogrel (hazard ratio: 0·74, 0·46–1·16). There was no significant difference in severe bleeding (1·6% placebo vs. 1·4% clopidogrel, hazard ratio: 0·83, 95% confidence intervals: 0·34–2·01).

Conclusion

The data are consistent with, but do not prove the hypothesis that early addition of clopidogrel to acetylsalicylic acid in patients with transient ischaemic attack and ischaemic stroke of arterial origin may be more effective and acceptably safe compared with acetylsalicylic acid alone. Adequately powered clinical trials that are dedicated to exploring this hypothesis are needed.
Intravenous Recombinant Tissue Plasminogen Activator Administered after 3 H following Onset of Ischaemic Stroke: A Metaanalysis
Authors: Maiser Samuel J. , Georgiadis Alexandros L. , Suri M. Fareed K. , Vazquez Gabriela , Lakshminarayan Kamakshi , Qureshi Adnan I.
Published: January 2011

Objective

To assess the efficacy of intravenous recombinant tissue plasminogen activator administered after 3 h following onset of ischaemic stroke.

Background

Some recent data indicate that treatment with intravenous recombinant tissue plasminogen activator may be beneficial even when administered to ischaemic stroke patients beyond 3 h from symptom onset.

Methods

We searched the medical literature using the MEDLINE, BIOSIS, and Cochrane databases for pertinent publications from 1966 to 2008 using the keywords ‘alteplase’, ‘tissue plasminogen activator’, and ‘stroke’. Among the retrieved publications, we selected randomised controlled trials that administered recombinant tissue plasminogen activator during 3–6 h after symptom onset in patients with acute ischaemic stroke. We evaluated the effect of intravenous recombinant tissue plasminogen activator (compared with placebo) on the rate of good functional outcome (determined by modified Rankin Scale of 0–1) and mortality at three-months. A subset analysis was performed according to time of administration of intravenous recombinant tissue plasminogen activator (3–4·5 and 4·5–6 h). Odds ratios of individual trials were pooled using a random effects model.

Results

We analysed four randomised trials totaling 2104 patients (1053 control and 1051 recombinant tissue plasminogen activator-treated patients). Patients that received intravenous recombinant tissue plasminogen activator at 3–6 h following onset of symptoms had a significantly higher rate of favourable neurological outcome over the patients that received placebo (odds ratio 1·24, 95% confidence intervals 1·04–1·47, P=0·02). Treatment within the 3–4·5 time window was significantly associated with higher rate of favourable neurological outcome (OR 1·27, 95% confidence interval 1·01–1·60), but not for the 4·5–6 time window (OR 1·10, 95% confidence interval 0·75–1·51). There was no difference in mortality between patients that received intravenous recombinant tissue plasminogen activator than the patients that received pharmacologic placebo (OR 1·14, 95% confidence interval 0·76–1·70).

Conclusions

Treatment with intravenous recombinant tissue plasminogen activator from 3–4·5 h following symptom onset is associated with an increased rate of favourable outcome at 90-days in this analysis. Treatment with intravenous recombinant tissue plasminogen activator beyond 4·5 h did not show a benefit; however, improved patient selection is needed for future studies.
The psychometric properties of the Tinnitus Handicap Questionnaire in a Dutch‐speaking population
Authors: Vanneste S. , To W. T. , De Ridder D.
Published: January 2011

Clin. Otolaryngol. 2011, 36, 9–16

Objective:  The aim of the study is to translate and validate the tinnitus handicap questionnaire (THQ) for a Dutch‐speaking population. The factor structure of the questionnaire, the reliability and the validity is determined. Furthermore, a statistical comparison with the original English version of the tinnitus handicap questionnaire is performed.

Methodology:  We assessed 101 patients at the Tinnitus Research Initiative clinic of Antwerp University Hospital. Twenty‐seven Dutch items from the tinnitus handicap questionnaire by Kuk et al. [(1990), Ear Hear11:434‐45.] were obtained by the process of translation and back translation. The factor structure, internal consistency, was evaluated using Cronbach’s alpha coefficient and item correlations were used to confirm reliability. The construct validity was confirmed with a visual analogue scale for loudness and distress, awareness, annoyance, the Tinnitus Questionnaire (TQ), the mini‐Tinnitus Questionnaire, the Hospital Anxiety and Depression Scale (HADS), the Beck Depression Inventory (BDI) and the Profile of Mood State (POMS), ensuring that this new instrument measures the tinnitus handicap.

Results:  This study demonstrates that the Dutch version of the tinnitus handicap questionnaire is a reliable (Cronbach’s alpha coefficient α = 0.93) and valid measure of self‐perceived tinnitus‐related distress [with visual analogue scale for loudness (r = 0.39) and distress (r = 0.45), awareness (r = 0.39), annoyance (r = 0.57), the Tinnitus Questionnaire (r = 0.82), the mini‐Tinnitus Questionnaire (r = 0.79), the Hospital Anxiety and Depression Scale (r = 0.62) and the Beck Depression Inventory (r = 0.32)]. The psychometric properties are in line with previous findings on the English version with regard to reliability and validity. However, the items in the subscales differ from the English version. While the English version has three subscales, our version has only two subscales. Yet, the English version reports that for the three factors, there is a low internal consistency and low correlation among the different items. For the Dutch‐speaking version, both factors show a very high reliability and validity.

Conclusions:  The tinnitus handicap questionnaire is suitable for assessing the handicapping effects of tinnitus among a Dutch‐speaking population in both clinical and research settings.
Fracture Clavicle with Acromioclavicular Dislocation: A Complex Injury
Authors: Kakwani Rajeshkumar G. , Tourret Lisa J.
Published: January 2011

Isolated injuries of the acromioclavicular joint and clavicle shaft fracture are very common. However, the combination injury of mid-clavicular fracture with acromioclavicular dislocation is very rare. We present a case of fracture of midshaft clavicle with acromioclavicular dislocation treated with contoured clavicular locking plate and Tightrope (Arthrex Inc., Naples, FL, USA) stabilization of the acromioclavicular dislocation.
Components of neuronal chloride transport in rat and human neocortex
Authors: Deisz Rudolf A. , Lehmann Thomas‐N. , Horn Peter , Dehnicke Christoph , Nitsch Robert
Published: January 2011

Non‐technical summary The inhibitory neurotransmitter GABA activates two distinct receptors of which the GABAAreceptor is mainly a Cl−conducting ion channel. The proper functioning of inhibition at the GABAAreceptor depends on the ionic gradient prevailing during receptor activation, and in epilepsy there is an aberrant Cl−gradient. Using rat and human cortical neurones and pharmacological inhibitors, we calculated the contributions of neuronal Cl−extrusion by the Na+–K+–2Cl−transporter NKCC1, the K+‐coupled Cl−transporter KCC2 and the voltage‐gated Cl−channel ClC2. We found that KCC2 is the major route of Cl−extrusion and that reduced KCC2 Cl−extrusion is likely to be the initial step of disturbed Cl−regulation. The results contribute to our understanding of epilepsy.
Cyclophilin‐D is dispensable for atrophy and mitochondrial apoptotic signalling in denervated muscle
Authors: Daussin Frederic N. , Godin Richard , Ascah Alexis , Deschênes Sonia , Burelle Yan
Published: January 2011

Non‐technical summary Activation of apoptotic cell death signalling by mitochondria is involved in mediating skeletal muscle atrophy following denervation. However, the underlying molecular mechanisms remain unclear, in particular the role of the permeability transition pore (PTP), a high conductance non specific channel of the mitochondrial inner membrane involved in cell death. Using Ppif−/− mice, which are devoid of the PTP sensitizing protein cyclophilin‐D and thus more resistant to pore opening, we directly tested the hypothesis that this pore is involved in atrophy and activation of apoptotic proteolytic signalling following denervation. Our results demonstrate that cyclophilin‐D, and by extension opening of the PTP, is dispensable for atrophy and activation of apoptotic proteolytic signalling induced by denervation.
Functional sympatholysis is impaired in hypertensive humans
Authors: Vongpatanasin Wanpen , Wang Zhongyun , Arbique Debbie , Arbique Gary , Adams‐Huet Beverley , Mitchell Jere H. , Victor Ronald G. , Thomas Gail D.
Published: January 2011

Non‐technical summary  In healthy individuals, blunting of the vasoconstriction caused by activation of the sympathetic nervous system is thought to be an important mechanism that optimizes blood flow to the working muscles. We show for the first time that this protective mechanism, called functional sympatholysis, is impaired in middle‐aged patients with high blood pressure. We also show that this impairment can be reversed by treatment with an angiotensin receptor blocker, but not with a thiazide‐type diuretic. These findings indicate that angiotensin II may augment sympathetic vasoconstriction in the active muscles of hypertensive humans, which may explain the exaggerated rise in blood pressure and blunted decline in systemic vascular resistance during exercise in this population.
Regional genomic regulation of cardiac sodium–calcium exchanger by oestrogen
Authors: Chen Guojun , Yang Xiaoyan , Alber Sean , Shusterman Vladimir , Salama Guy
Published: January 2011

Non‐technical summary Women of child bearing age are known to have longer QT intervals on their electrocardiogram recordings due to sex‐differences in the heart that are mediated by the sex hormone oestrogen. This results in a higher risk of lethal arrhythmias in women when their QT interval is prolonged further through drugs or inherited congenital diseases (i.e. long QT syndrome). Using rabbit hearts, which exhibit the same sex‐differences as in humans, it is here shown for the first time that oestrogen up‐regulates the sodium–calcium exchanger (NCX), a critical protein that regulates calcium ions in the heart and thereby alters the force of contraction, but only at the base of the ventricles (where the heart has its widest cross section). This effect accounts for the greater risk of long QT‐related arrhythmias in women.
Flexural Vibration Band Gap in a Periodic Fluid-Conveying Pipe System Based on the Timoshenko Beam Theory
Authors: Yu Dianlong , Wen Jihong , Zhao Honggang , Liu Yaozong , Wen Xisen
Published: January 2011

The flexural vibration band gap in a periodic fluid-conveying pipe system is studied based on the Timoshenko beam theory. The band structure of the flexural wave is calculated with a transfer matrix method to investigate the gap frequency range. The effects of the rotary inertia and shear deformation on the gap frequency range are considered. The frequency response of finite periodic pipe is calculated with a finite element method to validate the gap frequency ranges.
Modeling and Testing of a Novel Aeroelastic Flutter Energy Harvester
Authors: Bryant Matthew , Garcia Ephrahim
Published: January 2011

This paper proposes a novel piezoelectric energy harvesting device driven by aeroelastic flutter vibrations of a simple pin connected flap and beam. The system is subject to a modal convergence flutter response above a critical wind speed and then oscillates in a limit cycle at higher wind speeds. A linearized analytical model of the device is derived to include the effects of the three-way coupling between the structural, unsteady aerodynamic, and electrical aspects of the system. A stability analysis of this model is presented to determine the frequency and wind speed at the onset of the flutter instability, which dictates the cut-in conditions for energy harvesting. In order to estimate the electrical output of the energy harvester, the amplitude and frequency of the flutter limit cycle are also investigated. The limit cycle behavior is simulated in the time domain with a semi-empirical nonlinear model that accounts for the effects of the dynamic stall over the flap at large deflections. Wind tunnel test results are presented to determine the empirical aerodynamic model coefficients and to characterize the power output and flutter frequency of the energy harvester as functions of incident wind speed.
Reactive ion etching of tellurite and chalcogenide waveguides using hydrogen, methane, and argon
Authors: Vu K. T. , Madden S. J.
Published: January 2011

The authors report in detail on the reactive plasma etching properties of tellurium and demonstrate a high quality etching process using hydrogen, methane, and argon. Very low loss planar ridge waveguides are demonstrated. Optical losses in tellurium dioxide waveguides below 0.1 dB/cm in most of the near infrared region of the electromagnetic spectrum and at 1550 nm have been achieved—the lowest ever reported by more than an order of magnitude and clearly suitable for planar integrated devices. The etch process is also shown to be suitable for chalcogenide glasses which may be of importance in applications such as phase change memory devices and nonlinear integrated optics.
Plasma thinned nanopost arrays for DNA electrophoresis
Authors: Ou Jia , Joswiak Mark N. , Carpenter Samuel J. , Dorfman Kevin D.
Published: January 2011

Separating long DNA in a microfabricated post array requires (tens of) thousands of posts in the separation channel. Moving from microposts to nanoposts is thus a fabrication challenge owing to the large area that needs to be nanopatterned. The authors implemented an oxygen plasma etching method in conjunction with conventional optical photolithography and deep trench etching that led to centimeter-long microchannels containing either 360 or 460 nm diameter posts in a hexagonal array with a 3 μm spacing. Separations of the XhoI λ-DNA digest in the device indicate that these sparse nanopost arrays are an improvement over the equivalent micropost array with only a marginal increase in fabrication cost. The fabrication method described here is broadly applicable to biological microfluidic and nanofluidic platforms that require nanoscale features with micrometer-scale spacing.
The p53 Pathway as a Target in Cancer Therapeutics: Obstacles and Promise
Authors: Mandinova Anna , Lee Sam W.
Published: January 2011

The complex role of the tumor suppressor p53 in normal and malignant cells complicates efforts to target it for cancer therapy.
Voltammetric detection of nitroaromatic compounds using carbon-nanomaterials-based electrodes
Authors: Zhang Hong-Xia , Zhang Jun-Hong
Published: January 2011

The morphology of glassy carbon surfaces was investigated by the atomic force microscope (AFM) method. Multi-wall carbon nanotubes (MWCNTs) were purified and investigated with a scanning electron microscope (SEM) and a transmission electron microscope (TEM). An electrochemical technique based on the glassy carbon electrode (GCE) or MWCNT-modified GCEs was used for the detection of nitroaromatic compounds (NACs), namely 2,4,6-trinitrotoluene (TNT), 1,3,5-trinitrobenzene (TNB), 2,4-dinitrotoluene (2,4-DNT), and 1,3-dinitrobenzene (1,3-DNB). MWCNT-modified GCEs were more sensitive than GCEs to TNB, 2,4-DNT, and 1,3-DNB, with the detection limit down to ppb level, whereas the modified GCEs showed lower sensitivity to TNT. In varying degrees, the accumulation of nitro compounds can be promoted by MWCNT-modified GCEs in the detection process, a property which can be attributed to the large surface area and graphene-sheet structure of MWCNTs.
Gas-phase reaction chemistry of 1,1-dimethyl-1-silacyclobutane as a precursor gas in the hot-wire chemical vapor deposition process — Formation of tetramethylsilane and trimethylsilane
Authors: Tong L. , Shi Y. J.
Published: January 2011

The secondary gas-phase reaction products of 1,1-dimethyl-1-silacyclobutane (DMSCB) and its isotopomer, 1,1-di(perdeuteratedmethyl)-1-silacyclobutane (DMSCB-d6), in a hot-wire chemical vapour deposition reactor were investigated using vacuum UV laser single photon ionization with time-of-flight mass spectrometry. Dimethylsilylene, one of the primary decomposition products, undergoes π-type addition across the double and triple C–C bond and an insertion reaction into the Si–H bond. A short-chain reaction mechanism, initiated by methyl radicals produced in the primary decomposition, is found to exist for both the source DMSCB molecule and its stable secondary products. The formation of tetramethylsilane and trimethylsilane via the reaction of 1,1-dimethylsilene with a methyl radical and an H2 molecule, respectively, has been demonstrated. These are two new reaction channels involving 1,1-dimethylsilene in secondary gas-phase reactions.
Poly(para-phenylene ethynylene)s functionalized with Gd(III) chelates as potential MRI contrast agents
Authors: Atkins Katelyn M. , Martínez Francisco M. , Nazemi Ali , Scholl Timothy J. , Gillies Elizabeth R.
Published: January 2011

A poly(para-phenylene ethynylene) with water-solubilizing groups and Gd(III) chelates conjugated to the polymer backbone was designed and synthesized. Pre- and post-polymerization functionalization approaches were explored and the pre-polymerization approach for the introduction of the Gd(III) chelate was found to be more successful. The UV–vis absorption and fluorescence emission properties of the protected polymers were characterized and were found to be consistent with the results expected for this class of polymers. Removal of the protecting groups followed by chelation of Gd(III) led to a water-dispersible polymer. Relaxivity measurements were performed on this polymer with the aim of evaluating its potential as a new MRI contrast agent, and an r1 of 1.37 L mmol–1 s–1 at 310 K and 20 MHz was determined. These results, along with dynamic light scattering analyses, suggested that the polymers formed micrometre-sized assemblies in aqueous solution. Although the relaxivity was relatively modest, these results provide important insights into the assembly properties of this new class of polymers and into the design criteria for future agents.
(–)-6α-Hydroxy polyanthellin A — A novel antifouling diterpenoid from the Indian soft coral Cladiella krempfi (Hickson)
Authors: Mol V. P. Limna , Raveendran T. V. , Parameswaran P. S. , Kunnath R. J. , Rajamohanan P. R.
Published: January 2011

Bioassay-guided purification of methanol extract of the soft coral Cladiella krempfi (Octocorallia: Alcynocea) yielded a novel eunicellin-type diterpenoid, (–)-6α-hydroxy polyanthellin A (1), active against the cyprids of the fouling barnacle, Balanus amphitrite (EC50 9.02 µg/mL; LC50 36 µg/mL; and therapeutic ratio = 4). The structure of compound 1 was determined from its spectral data, including IR, NMR (1D and 2D NMR), and mass spectra.
Metabolomic Study of a Rat Fever Model Induced with 2,4-Dinitrophenol and the Therapeutic Effects of a Crude Drug Derived from Coptis chinensis
Authors: Liu Shumin , Lu Fang , Wang Xijun , Sun Wenjun , Chen Pingping , Dong Wanru
Published: January 2011

This study describes the metabonomics of fevers in animal models and the therapeutic effects of Rhizoma coptidis extract (RCE) on them. The rat urinary samples were analyzed by UPLC/ ESI–Q-TOF/MS, combined with principal component analysis (PCA). Nine ions were chosen to characterize the similarities and differences in the responses to fever. The ion at m/z 206.0278 was unambiguously identified to be xanthurenic acid. This study demonstrated that the metabonomic approach can readily distinguish between febrile and healthy individuals. This data support the contention that the metabonomic approach represents a promising new technology for the development of rapid-throughput in vivo fever screening. Furthermore, this approach can detect the interfering effects of RCE. This investigation has led the authors to believe that metabonomics is a valid approach for explaining the therapeutic effects of traditional Chinese medicine on fevers.
Clarification of the Phenotypic Characteristics and Anti-Tumor Activity of Hedyotis diffusa
Authors: Lee Hong-Zin , Bau Da-Tian , Kuo Chao-Lin , Tsai Ru-Yin , Chen Yu-Chang , Chang Yu-Hao
Published: January 2011

Hedyotis diffusa Willd. (Rubiaceae) is an important folk herb used to prevent and cure hepatitis and liver cancer in Taiwan. For differentiation of H. diffusa from counterfeits, macroscopic and microscopic characters of H. diffusa, H. corymbosa and H. tenelliflora were examined in this study. According to Trypan blue exclusion assay and Western blot analysis, H. diffusa had a significant inhibition of cell growth and induction of cell apoptosis in COLO 205 (colon cancer), Hep 3B (hepatocellular carcinoma) and H460 (lung cancer) cell lines. This study also used high-performance liquid chromatography (HPLC) to determine the quality control of H. diffusa. The HPLC data showed that ursolic and oleanolic acid are the components of the H. diffusa, consisting of approximately 4.66–4.80% and 1.86–1.96%, respectively. Our study also demonstrated that ursolic acid has significant anti-tumor activity in COLO 205, Hep 3B and H460 cancer cells.
A DYNAMIC LOAD BALANCING MODEL FOR CONCURRENTLY CONNECTED USERS IN U-HEALTHCARE MONITORING SYSTEMS
Authors: LEE MALREY , LEE KEUN-KWANG
Published: January 2011

U-healthcare systems are based on a ubiquitous and wireless computing and communication environment. They are comprised of the U-healthcare management center, electronic medical records (EMR) system, and the associated services for users and patients. The U-healthcare management center performs continuous monitoring and provides support services in multiple areas, requiring careful allocation of the limited service resources to provide customized healthcare services for users of the mobile distributed system. When the number of locally connected users increases rapidly, a mobile allocation and distribution server can be imbalanced by the load on service resources, resulting in delayed services. This study proposes a dynamic load balancing model for reducing the load of users on service resources and supporting efficient response services in a mobile distributed system. The proposed dynamic load balancing model clusters the system resources of servers dynamically, according to each users' movement and time. The dynamic clustering of system resources uses wFCM (weighted Fuzzy C-Means), which changes the cluster center by transforming existing FCM (Fuzzy C-Means) from a fixed weight to a dynamic one. Using wFCM, the load balance can be maintained, based on the usage rate of service resources, such as CPU, memory, and network. In addition, the balance between QoS (Quality of Service) requests and network response times can be maintained by adding an abstraction layer between application services and network infrastructure. Therefore, when the proposed model is applied to a U-healthcare monitoring system, the system can perform near real-time monitoring of service users in the mobile distributed environment, and effectively address emergent situations. This study evaluates the response time of the implemented model in relation to the number of concurrently connected users, and confirms that the proposed model is faster in response and service processing than existing WLC (Weighted Least-Connection Scheduling) and FCM (Fuzzy C-Means).
PHONON DRAG, CARRIER DIFFUSIVE THERMOELECTRIC POWER AND SEMICONDUCTING RESISTIVITY BEHAVIOR OF Zn NANOWIRES
Authors: CHOUDHARY K. K. , PRASAD D. , JAYAKUMAR K. , VARSHNEY DINESH
Published: January 2011

In this paper, we undertake a quantitative analysis of observed temperature-dependent thermoelectric power (S) of 4 nm Zn /Vycor composite nanowires by developing a model Hamiltonian that incorporates scattering of acoustic phonons with impurities, grain boundaries, charge carriers and phonons. Mott expression is used to determine the carrier diffusive thermoelectric power [Formula: see text]. The [Formula: see text] shows linear temperature dependence and the computed [Formula: see text] when subtracted from the experimental data is interpreted as phonon drag thermoelectric power [Formula: see text]. The model Hamiltonian within the relaxation time approximation sets the limitations of the scattering of acoustic phonons with impurities, grain boundaries, charge carriers and phonons for thermoelectric power in the nanowires. It is shown that for acoustic phonons the scattering and transport cross sections are proportional to fourth power of the phonon in the Rayleigh regime. The resultant thermoelectric powers is an artefact of various operating scattering mechanisms and are computed for the first time to our knowledge for Zn nanowires consistent with the experimentally reported behavior. The semiconducting nature of resistivity is discussed with small polaron conduction (SPC) model which consistently retraces the temperature-dependent resistivity behavior of Zn /Vycor composite.
ATOMISTIC MODELING OF THE FORMATION AND STABILITY OFNiANDVNANOWIRES ON A STEPPEDRh(553)SUBSTRATE
Authors: KARA D. C. , DREXEL M. S. , BOZZOLO G. , MOSCA H. O.
Published: January 2011

The formation and stability of Ni and V nanowires on a stepped Rh(553) substrate is investigated using the BFS method for alloys via an atom-by-atom description of the formation process. In agreement with experiment, Ni is found to form one-dimensional wires attached to the surface steps, while V does not. However, a detailed analysis of the energetics reveals that there the apparent differences leave room for the possibility of alloying in the case of Ni and the formation of structures along the step in the case of V .
INVESTIGATION OF MICROWAVE ABSORPTION PROPERTY IN CARBON NANOFIBER FILM SYNTHESIZED FROM LINUM USITATISSIMUM OIL
Authors: KSHIRSAGAR DATTATRAYA E. , PURI VIJAYA , ZACHARIAH MANESH , SHARON MADHURI , ZITTI E. DI. , SHARON MAHESHWAR
Published: January 2011

Carbon nanofiber (CNF) films synthesized from linum usitatissimum seed oil at 850°C have been studied as a microwave absorber. Scanning electron microscopy, transmission electron microscopy, micro-Raman spectroscopy, and Fourier transform infrared spectroscopy reveal the graphitic nature of fibers, having uniform diameter ~ 600 nm. Results of microwave absorption study explore high absorption efficiency of CNF film, contributed by low reflection of about -20 to -29 dB. Shielding effectiveness for the film observed between -31 and -60 dB in 8–12 GHz range.
SNAKE-SHAPED GOLD NANOSTRUCTURES FROM HYDROXYETHYL CELLULOSE MEDIATED SYNTHESIS
Authors: SHAHITHA FATHIMA , HUSSAIN JAHIR , VALIYAVEETTIL SURESH
Published: January 2011

Gold nanomaterials are becoming increasingly important in a variety of applications. The size and shape control in the chemical synthesis of nanostructures is particularly important due to their potential in sensing or imaging applications. Snake-shaped gold nanostructures have been synthesized using environmentally benign conditions. Hydroxyethyl cellulose (HEC) was used as a reducing and stabilizing agent for the synthesis of gold nanostructures from hydrogen tetrachloroaurate(III) trihydrate (HAuCl4) in water. The gold nanostructures showed snake-shaped particles with a head size from 30 to 50 nm and a tail length of 100 nm to 600 nm. The size of the nanostructure can be easily tailored by varying the concentrations of HAuCl4 and HEC. The UV–Vis spectroscopy studies showed that the gold nanostructures have a strong visible absorption in the range of 525–535 nm. The particles were purple in color and stable for several months in solution without aggregation.
HETEROSTRUCTURED HYBRID COLLOIDAL SEMICONDUCTOR NANOCRYSTALS
Authors: CHAN YIN THAI
Published: December 2010

Significant efforts in the field of colloidal semiconductor particles have been dedicated to the fabrication and study of hybrid metal–semiconductor nanoheterostructures, where the incorporation of the metal moiety may potentially enhance and/or expand existing applications of semiconductor nanoparticles. Many of these metal–semiconductor nanostructured constructs exhibit physical properties not found in either of their metal or semiconductor components, providing many opportunities for further investigation into interface and coupling effects between the two materials. We review some of the key research endeavors in this area, focusing mainly on the synthesis of the materials and the characterization of the various metal–semiconductor constructs, and highlighting some of the unique applications that have emerged from these efforts.