bluuebunny/crossref_metadata_2025_split huggingface dataset:
Critique and Improvement of a One-Dimensional Semianalytical Model of a Direct Methanol Fuel Cell
Authors: Kuo C. C. , Lear W. E. , Fletcher J. H. , Crisalle O. D. 
Published: August 2012

Abstract
A constructive critique and a suite of proposed improvements for a recent one-dimensional semianalytical model of a direct methanol fuel cell are presented for the purpose of improving the predictive ability of the modeling approach. The model produces a polarization curve for a fuel cell system comprised of a single membrane-electrode assembly, based on a semianalytical one-dimensional solution of the steady-state methanol concentration profile across relevant layers of the membrane electrode assembly. The first improvement proposed is a more precise numerical solution method for an implicit equation that describes the overall current density, leading to better convergence properties. A second improvement is a new technique for identifying the maximum achievable current density, an important piece of information necessary to avoid divergence of the implicit-equation solver. Third, a modeling improvement is introduced through the adoption of a linear ion-conductivity model that enhances the ability to better match experimental polarization-curve data at high current densities. Fourth, a systematic method is advanced for extracting anodic and cathodic transfer-coefficient parameters from experimental data via a least-squares regression procedure, eliminating a potentially significant parameter estimation error. Finally, this study determines that the methanol concentration boundary condition imposed on the membrane side of the membrane-cathode interface plays a critical role in the model’s ability to predict the limiting current density. Furthermore, the study argues for the need to carry out additional experimental work to identify more meaningful boundary concentration values realized by the cell.
Investigation of four‐dimensional (4D) Monte Carlo dose calculation in real‐time tumor tracking stereotatic body radiotherapy for lung cancers
Authors: Chan Mark K. H. , Kwong Dora L. W. , Ng Sherry C. Y. , Tam Eric K. W. , Tong Anthony S. M. 
Published: August 2012

Purpose:To investigate the dosimetric variations and radiobiological impacts as a consequence of delivering treatment plans of 3D nature in 4D manner based on the 4D Monte Carlo treatment planning framework implemented on Cyberknife.Methods:Dose distributions were optimized on reference 3D images at end of exhale phase of a 4DCT dataset for 25 lung cancer patients treated with 60 Gy/3Fx or 48 Gy/4Fx. Deformable image registrations between individual 3DCT images to the reference 3DCT image in the 4DCT study were performed to interpolate doses calculated on multiple anatomical geometries back on to the reference geometry to compose a 4D dose distribution that included the tracking beam motion and organ deformation. The 3D and 4D dose distributions that were initially calculated with the equivalent path‐length (EPL) algorithm (3DEPL dose and 4DEPL dose) were recalculated with the Monte Carlo algorithm (3DMC dose and 4DMC dose). Dosimetric variations of V60Gy/48Gy and D99 of GTV, mean doses to the lung and the heart and maximum dose (D1) of the spinal cord as a consequence of tracking beam motion in deforming anatomy, dose calculation algorithm, and both were quantified by the relative change from 4DMC to 3DMC doses, from 4DMC to 4DEPL doses, and from 4DMC to 3DEPL doses, respectively.Results:Comparing 4DMC to 3DEPL plans, V60Gy / 48Gy and D99 of GTV decreased considerably by 13 ± 22% (mean ± 1SD) and 9.2 ± 5.5 Gy but changes of normal tissue doses were not more than 0.5 Gy on average. The generalized equivalent uniform dose (gEUD) and tumor control probability (TCP) were reduced by 14.3 ± 8.8 Gy and 7.5 ± 5.2%, and normal tissue complication probability (NTCP) for myelopathy and pericarditis were close to zero and NTCP for radiation pneumonitis was reduced by 2.5% ± 4.1%. Comparing 4DMC to 4DEPL plans found decreased V60Gy/48Gy and D99 by 12.3% ± 21.6% and 7.3 ± 5.3 Gy, the normal tissues doses by 0.5 Gy on average, gEUD and TCP by 13.0 ± 8.6 Gy and 7.1% ± 5.1%. Comparing 4DMC to 3DMC doses, V60Gy/48Gy and D99 of GTV was reduced by 5.2% ± 8.8% and 2.6 ± 3.3 Gy, and normal tissues hardly changed from 4DMC to 3DMC doses. The corresponding decreases of gEUD and TCP were 2.8 ± 4.0 Gy and 1.6 ± 2.4%.Conclusions:The large discrepancy between original 3DEPL plan and benchmarking 4DMC plan is predominately due to dose calculation algorithms as the tracking beam motion and organ deformation hardly influenced doses of normal tissues and moderately decreased V60Gy/48Gy and D99 of GTV. It is worth to make a thoughtful weight of the benefits of full 4DMC dose calculation and consider 3DMC dose calculation as a compromise of 4DMC dose calculation considering the multifold computation time.
Equity of access to specialist chronic fatigue syndrome (CFS/ME) services in England (2008–2010): a national survey and cross-sectional study
Authors: Collin Simon M , Sterne Jonathan A C , Hollingworth William , May Margaret T , Crawley Esther 
Published: August 2012

ObjectivesProvision of National Health Service (NHS) specialist chronic fatigue syndrome or myalgic encephalomyelitis (CFS/ME) services in England has been deemed patchy and inconsistent. Our objective was to explore variation in the provision of NHS specialist CFS/ME services and to investigate whether access is related to measures of deprivation and inequality.DesignSurvey of all CFS/ME clinical teams in England, plus cross-sectional data from a subset of teams.SettingSecondary care.Outcome measuresWe used clinic activity data from CFS/ME clinical teams in England to describe provision of specialist CFS/ME services (referral, assessment and diagnosis rates per 1000 adults per year) during 2008–2011 according to Primary Care Trust (PCT) population estimates, and to investigate whether use of services was related to PCT-level measures of deprivation and inequality. We used postcode data from seven services to investigate variation in provision by deprivation.ResultsClinic activity data were obtained from 93.9% (46/49) of clinical teams in England which between them received referrals from 84.9% (129/152) of PCTs. 12 PCTs, covering a population of 2.08 million adults, provided no specialist CFS/ME service. There was a six-fold variation in referral and assessment rates between services which could not be explained by PCT-level measures of deprivation and inequality. The median assessment rate in 2010 was 0.25 (IQR 0.17, 0.35) per 1000 adults per year. 91.9% (IQR 76.5%, 100.0%) of adults assessed were diagnosed with CFS/ME. Postcode data from seven clinical teams showed that assessment rates were equal across deprivation quartiles for four teams but were 40–50% lower in the most deprived compared with the most affluent areas for three teams.ConclusionsTwo million adults in England do not have access to a specialist CFS/ME service. In some areas which do have a specialist service, access is inequitable. This inequity may worsen with the impending fragmentation of NHS commissioning across England.
Dabigatran versus rivaroxaban for the prevention of stroke and systemic embolism in atrial fibrillation in Canada
Authors: Sharma Michael , Bradley-Kennedy Carole , Clemens Andreas , Monz Brigitta U. , Peng Siyang , Roskell Neil , Sorensen Sonja V. , Kansal Anuraag R. 
Published: August 2012

SummaryCanadian patients with atrial fibrillation (AF) in whom anticoagulation is appropriate have two new choices for anticoagulation for prevention of stroke and systemic embolism – dabigatran etexilate (dabigatran) and rivaroxaban. Based on the RE-LY and ROCKET AF trial results, we investigated the cost-effectiveness of dabigatran (twice daily dosing of 150 mg or 110 mg based on patient age) versus rivaroxaban from a Canadian payer perspective. A formal indirect treatment comparison (ITC) of dabigatran versus rivaroxaban was performed, using dabigatran clinical event rates from RE-LY for the safety-on-treatment population, adjusted to the ROCKET AF population. A previously described Markov model was modified to simulate anticoagulation treatment using ITC results as inputs. Model outputs included total costs, event rates, and quality-adjusted life-years (QALYs). The ITC found when compared to rivaroxaban, dabigatran had a lower risk of intracranial haemorrhage (ICH) (relative risk [RR] = 0.38; 95% confidence interval [CI] 0.21 –0.67) and stroke (RR = 0.62; 95%CI 0.45–0.87). Over a lifetime horizon, the model found dabigatran-treated patients experienced fewer ICHs (0.33 dabigatran vs. 0.71 rivaroxaban) and ischaemic strokes (3.40 vs. 3.96) per 100 patient-years, and accrued more QALYs (6.17 vs. 6.01). Dabigatran-treated patients had lower acute care and long-term follow-up costs per patient ($52,314 vs. $53,638) which more than offset differences in drug costs ($7,299 vs. $6,128). In probabilistic analysis, dabigatran had high probability of being the most cost-effective therapy at common thresholds of willingness-to-pay (93% at a $20,000/QALY threshold). This study found dabigatran is economically dominant versus rivaroxaban for prevention of stroke and systemic embolism among Canadian AF patients.
Endogenous Renovascular Hypertension Combined With Low Shear Stress Induces Plaque Rupture in Apolipoprotein E–Deficient Mice
Authors: Jin Shu-xuan , Shen Ling-hong , Nie Peng , Yuan Wei , Hu Liu-hua , Li Dan-dan , Chen Xue-jin , Zhang Xiao-kun , He Ben 
Published: August 2012

Objective—
The development of a murine model of spontaneous atherosclerotic plaque rupture with luminal thrombus.

Methods and Results—
Combined partial ligation of the left renal artery and left common carotid artery in 8-week-old apolipoprotein E–deficient mice induced endogenous renovascular hypertension and local low oscillatory shear stress in the left common carotid artery. After 8 weeks, a fresh left common carotid artery lumen thrombus associated with severe plaque burden was found in 50% (10/20) of the mice. Histological analyses indicated that all left common carotid artery lesions had vulnerable features, and 50% (5/10) of the mice showed plaque rupture with a lumen thrombus. Multiple layers with layering discontinuity and intraplaque hemorrhages were found in 80% (8/10) of the mice. Further experiments showed that both increased blood pressure, and angiotensin-II contributed to plaque progression and vulnerability. Decreased intimal collagen associated with increased collagenase activity and matrix metalloproteinase expression also resulted in plaque disruption.

Conclusion—
We demonstrate a murine model of spontaneous plaque rupture with a high incidence of luminal thrombus. The model not only nicely recapitulates the pathophysiological processes of human plaque rupture but it is also simple, fast, and highly efficient to generate.
Monocyte Chemoattractant Protein-1/CCR2 Axis Promotes Vein Graft Neointimal Hyperplasia Through Its Signaling in Graft-Extrinsic Cell Populations
Authors: Fu Chunhua , Yu Peng , Tao Ming , Gupta Tushar , Moldawer Lyle L. , Berceli Scott A. , Jiang Zhihua 
Published: August 2012

Objective—
To evaluate direct versus indirect monocyte chemoattractant protein (MCP)-1/CCR2 signaling and to identify the cellular producers and effectors for MCP-1 during neointimal hyperplasia (NIH) development in vein grafts.

Methods and Results—
Genomic analysis revealed an overrepresentation of 13 inflammatory pathways in wild-type vein grafts compared with CCR2 knockout vein grafts. Further investigation with various vein graft–host combinations of MCP-1- and CCR2-deficient mice was used to modify the genotype of cells both inside (graft-intrinsic group) and outside (graft-extrinsic group) the vein wall. CCR2 deficiency inhibited NIH only when present in cells extrinsic to the graft wall, and MCP-1 deficiency required its effectiveness in cells both intrinsic and extrinsic to the graft wall to suppress NIH. Deletion of either MCP-1 or CCR2 was equally effective in inhibiting NIH. CCR2 deficiency in the predominant neointimal cell population had no impact on NIH. Direct MCP-1 stimulation of primary neointimal smooth muscle cells had minimal influence on cell proliferation and matrix turnover, confirming an indirect mechanism of action.

Conclusion—
MCP-1/CCR2 axis accelerates NIH via its signaling in graft-extrinsic cells, particularly circulating inflam-matory cells, with cells both intrinsic and extrinsic to the graft wall being critical MCP-1 producers. These findings underscore the importance of systemic treatment for anti–MCP-1/CCR2 therapies.
Ventilatory Power
Authors: Forman Daniel E. , Guazzi Marco , Myers Jonathan , Chase Paul , Bensimhon Daniel , Cahalin Lawrence P. , Peberdy Mary Ann , Ashley Euan , West Erin , Daniels Karla M. , Arena Ross 
Published: August 2012

Background—

Minute ventilation/CO
2
production (VE/V
co
2
) slope is an index determined by cardiopulmonary exercise testing, which incorporates pertinent cardiac, pulmonary, and skeletal muscle physiology into a substantive composite assessment. The VE/V
co
2
slope has many applications, including utility as a well-validated prognostic gauge for patients with heart failure (HF). In this study, we combine VE/V
co
2
slope with systolic blood pressure, creating a novel index that we labeled ventilatory power. Ventilatory power links the combined physiology inherent in the VE/V
co
2
slope to peripheral pressure, adding an additional dimension pertinent to HF assessment. Whereas the related concept of circulatory power links peak oxygen consumption with peak systolic blood pressure as a prognostic index, we hypothesized that ventilatory power would provide greater prognostic discrimination than VE/Vco2 slope, peak oxygen consumption, and circulatory power for patients with systolic HF.

Methods and Results—

Patients with systolic HF (left ventricular ejection fraction ≤35%) underwent symptom-limited cardiopulmonary exercise testing as part of routine management and were followed for up to 4 years for major cardiac events (mortality, left ventricular assist device implantation, and heart transplantation). Eight hundred seventy-five patients with HF (left ventricular ejection fraction, 26±9%; mean age, 55±14) were studied. Cardiopulmonary exercise testing indices peak oxygen consumption, VE/V
co
2
slope, circulatory power, and ventilatory power were all predictive of cardiac events (
P
<0.001). Multivariate analysis demonstrated that ventilatory power was the strongest indicator of prognosis.

Conclusions—
Although circulatory power and traditional cardiopulmonary exercise testing parameters can be used to predict prognosis among patients with HF, ventilatory power provides relatively greater prognostic discrimination and may constitute a relatively more useful composite tool.
Parental Electrocardiographic Screening Identifies a High Degree of Inheritance for Congenital and Childhood Nonimmune Isolated Atrioventricular Block
Authors: Baruteau Alban-Elouen , Behaghel Albin , Fouchard Swanny , Mabo Philippe , Schott Jean-Jacques , Dina Christian , Chatel Stéphanie , Villain Elisabeth , Thambo Jean-Benoit , Marçon François , Gournay Véronique , Rouault Francis , Chantepie Alain , Guillaumont Sophie , Godart François , Martins Raphaël P. , Delasalle Béatrice , Bonnet Caroline , Fraisse Alain , Schleich Jean-Marc , Lusson Jean-René , Dulac Yves , Daubert Jean-Claude , Le Marec Hervé , Probst Vincent 
Published: August 2012

Background—
The origin of congenital or childhood nonimmune isolated atrioventricular (AV) block remains unknown. We hypothesized that this conduction abnormality in the young may be a heritable disease.

Methods and Results—

A multicenter retrospective study (13 French referral centers, from 1980–2009) included 141 children with AV block diagnosed in utero, at birth, or before 15 years of age without structural heart abnormalities and without maternal antibodies. Parents and matched control subjects were investigated for family history and for ECG screening. In parents, a family history of sudden death or progressive cardiac conduction defect was found in 1.4% and 11.1%, respectively. Screening ECGs from 130 parents (mean age 42.0±6.8 years, 57 couples) were compared with those of 130 matched healthy control subjects. All parents were asymptomatic and in sinus rhythm, except for 1 with undetected complete AV block. Conduction abnormalities were more frequent in parents than in control subjects, found in 50.8% versus 4.6%, respectively (
P
<0.001). A long PR interval was found in 18.5% of the parents but never in control subjects (
P
<0.0001). Complete or incomplete right bundle-branch block was observed in 39.2% of the parents and 1.5% of the control subjects (
P
<0.0001). Complete or incomplete left bundle-branch block was found in 15.4% of the parents and 3.1% of the control subjects (
P
<0.0006). Estimated heritability for isolated conduction disturbances was 91% (95% confidence interval, 80%–100%).
SCN5A
mutation screening identified 2 mutations in 2 patients among 97 children.

Conclusions—
ECG screening in parents of children affected by idiopathic AV block revealed a high prevalence of conduction abnormalities. These results support the hypothesis of an inheritable trait in congenital and childhood nonimmune isolated AV block.
Poor Long-Term Blood Pressure Control After Intracerebral Hemorrhage
Authors: Zahuranec Darin B. , Wing Jeffrey J. , Edwards Dorothy F. , Menon Ravi S. , Fernandez Stephen J. , Burgess Richard E. , Sobotka Ian A. , German Laura , Trouth Anna J. , Shara Nawar M. , Gibbons M. Chris , Boden-Albala Bernadette , Kidwell Chelsea S. 
Published: August 2012

Background and Purpose—
Hypertension is the most important risk factor associated with intracerebral hemorrhage. We explored racial differences in blood pressure (BP) control after intracerebral hemorrhage and assessed predictors of BP control at presentation, 30 days, and 1 year in a prospective cohort study.

Methods—
Subjects with spontaneous intracerebral hemorrhage were identified from the DiffErenCes in the Imaging of Primary Hemorrhage based on Ethnicity or Race (DECIPHER) Project. BP was compared by race at each time point. Multivariable linear regression was used to determine predictors of presenting mean arterial pressure, and longitudinal linear regression was used to assess predictors of mean arterial pressure at follow-up.

Results—

A total of 162 patients were included (mean age, 59 years; 53% male; 77% black). Mean arterial pressure at presentation was 9.6 mm Hg higher in blacks than whites despite adjustment for confounders (
P
=0.065). Fewer than 20% of patients had normal BP (<120/80 mm Hg) at 30 days or 1 year. Although there was no difference at 30 days (
P
=0.331), blacks were more likely than whites to have Stage I/II hypertension at 1 year (
P
=0.036). Factors associated with lower mean arterial pressure at follow-up in multivariable analysis were being married at baseline (
P
=0.032) and living in a facility (versus personal residence) at the time of BP measurement (
P
=0.023).

Conclusions—
Long-term BP control is inadequate in patients after intracerebral hemorrhage, particularly in blacks. Further studies are needed to understand the role of social support and barriers to control to identify optimal approaches to improve BP in this high-risk population.
Evaluation of the Sensitivity of the Weather Research and Forecasting Model to Parameterization Schemes for Regional Climates of Europe over the Period 1990–95
Authors: Mooney P. A. , Mulligan F. J. , Fealy R. 
Published: August 2012

Abstract
The Weather Research and Forecasting model (WRF) is used to downscale interim ECMWF Re-Analysis (ERA-Interim) data for the climate over Europe for the period 1990–95 with grid spacing of 0.44° for 12 combinations of physical parameterizations. Two longwave radiation schemes, two land surface models (LSMs), two microphysics schemes, and two planetary boundary layer (PBL) schemes have been investigated while the remaining physics schemes were unchanged. WRF simulations are compared with Ensemble-Based Predictions of Climate Changes and their Impacts (ENSEMBLES) observations gridded dataset (E-OBS) for surface air temperatures (T2), precipitation, and mean sea level pressure (MSLP) in eight subregions within the model domain to assess the performance of the different parameterizations on widely varying regional climates. This work shows that T2 is modeled well by WRF with high correlation coefficients (0.8 &lt; R &lt; 0.95) and biases less than 4°C. T2 shows greatest sensitivity to land surface models, some sensitivity to longwave radiation schemes, and less sensitivity to microphysics and PBL schemes. Precipitation is not well modeled by WRF with low correlation coefficients (0.1 &lt; R &lt; 0.3) and high root-mean-square differences (RMSDs; 8–9 mm day−1). Precipitation shows sensitivity to LSMs in summer. No significant bias has been observed in the MSLP modeled by WRF. Correlation coefficients are typically in the range 0.7 &lt; R &lt; 0.8 while RMSDs are in the range 6–10 hPa. MSLP output is sensitive to longwave radiation scheme in summer but is relatively insensitive to either microphysics or the choice of LSM. The optimum combination of parameterizations for all three state variables examined is strongly dependent on subregion and demonstrates the need to carefully select parameterization combinations when attempting to use WRF as a regional climate model.
Impacts of the Bermuda High on Regional Climate and Ozone over the United States
Authors: Zhu Jinhong , Liang Xin-Zhong 
Published: August 2012

Abstract
Observations reveal that, in summer, westward extension of the Bermuda high enhances the Great Plains low-level jet (LLJ) that transports more moisture northward, causing precipitation increases in the Midwest and decreases in the Gulf States. Meanwhile, more warm air advection from the Gulf of Mexico to the southern Great Plains and stronger clear-sky radiative heating under high pressures over the Southeast result in warmer surface temperatures across the Gulf states. The enhanced LLJ transport of cleaner marine air from the Gulf reduces surface ozone across the southern Great Plains–Midwest. In contrast, larger transport of more polluted air from the Midwest to New England and more frequent air stagnation under high pressures in the Southeast increase ozone over most of the eastern coastal states. This Bermuda high–induced ozone change reversal between the southern Great Plains–Midwest and eastern coastal states, with a magnitude of 6 and 13.5 ppb, respectively, in summer-mean maximum daily 8-h average, exhibits strong decadal variations that should be considered in the U.S. air quality dynamic management.
The observed Bermuda high signatures over the Gulf states can be well captured by regional climate and air quality models. Notable model deficiencies exist over the northern Great Plains–Midwest that are more remote to the Bermuda high and LLJ control. The regional models largely reduce these deficiencies from general circulation models (GCMs). Only 7 out of 51 GCMs can represent all key regional signatures of the Bermuda high, while none can simulate its strong association with planetary sea surface temperature anomalies. The result indicates a great challenge for GCMs to predict Bermuda high variability and change.