bluuebunny/crossref_metadata_2025_split huggingface dataset:
[18F]T807, a novel tau positron emission tomography imaging agent for Alzheimer's disease
Authors: Xia Chun‐Fang , Arteaga Janna , Chen Gang , Gangadharmath Umesh , Gomez Luis F. , Kasi Dhanalakshmi , Lam Chung , Liang Qianwa , Liu Changhui , Mocharla Vani P. , Mu Fanrong , Sinha Anjana , Su Helen , Szardenings A. Katrin , Walsh Joseph C. , Wang Eric , Yu Chul , Zhang Wei , Zhao Tieming , Kolb Hartmuth C. 
Published: February 2013

AbstractObjectiveWe wished to develop a highly selective positron emission tomography (PET) imaging agent targeting PHF‐tau in human Alzheimer's disease (AD) brains.MethodsTo screen potential tau binders, human AD brain sections were used as a source of native paired helical filament (PHF)‐tau and Aβ rather than synthetic tau aggregates or Aβ fibrils generated in vitro to measure the affinity and selectivity of [18F]T807 to tau and Aβ. Brain uptake and biodistribution of [18F]T807 in mice were also tested.ResultsIn vitro autoradiography results show that [18F]T807 exhibits strong binding to PHF‐tau‐positive human brain sections. A dissociation constant (Kd) of [18F]T807 (14.6 nM) was measured using brain sections from the frontal lobe of AD patients. A comparison of autoradiography and double immunohistochemical staining of PHF‐tau and Aβ on adjacent sections demonstrated that [18F]T807 binding colocalized with immunoreactive PHF‐tau pathology, but did not highlight Aβ plaques. In vivo studies in mice demonstrated that [18F]T807 was able to cross the blood–brain barrier and washed out quickly.Conclusions[18F]T807 demonstrates high affinity and selectivity to PHF‐tau as well as favorable in vivo properties, making this a promising candidate as an imaging agent for AD.
Positron sound waves and nonlinear Landau damping of intense transverse EM waves in an isotropic EPI plasma
Authors: TSINTSADZE N. L. , CHAUDHARY R. , RASHEED A. 
Published: February 2013

AbstractRelativistically hot electron–positron–ion (EPI) plasmas in the presence of relativistic intense electromagnetic (EM) radiation that are not in thermal equilibrium are studied by following a modified plasma particle distribution function. By means of a kinetic description, soliton solution is obtained for a small amplitude EM wave, whereas for large amplitude EM waves a cusp soliton solution is obtained. A general expression of positron density oscillations is obtained for long wavelength in comparison with the Debye length of electrons, and is discussed for special cases. Dispersion relations for a new type of longitudinal waves with slow damping is formulated as a consequence of resonant wave–particle interaction, and the necessary conditions for the existence of positron sound waves are obtained. Furthermore, for ultrarelativistic electrons and non-relativistic positrons, quasi positron sound waves dispersion relation in the intermediate wave range is obtained. It is shown that the modulation of amplitude of relativistic EM waves leads to instability for the rare plasma. Finally, we have obtained the relativistic kinetic nonlinear Schrödinger equation (KNLS) with local and non-local nonlinearities. The KNLS equation depicts nonlinear Landau damping rates for intense EM waves, and these damping rates are also examined.
The Busemann–Petty problem in the complex hyperbolic space
Authors: DANN SUSANNA 
Published: February 2013

AbstractThe Busemann–Petty problem asks whether origin-symmetric convex bodies in ℝn with smaller central hyperplane sections necessarily have smaller volume. The answer is affirmative if n ≤ 4 and negative if n ≥ 5. We study this problem in the complex hyperbolic n-space ℍnℂ and prove that the answer is affirmative for n ≤ 2 and negative for n ≥ 3.
Integrally closed rings in birational extensions of two-dimensional regular local rings
Authors: OLBERDING BRUCE , TARTARONE FRANCESCA 
Published: February 2013

AbstractLet D be an integrally closed local Noetherian domain of Krull dimension 2, and let f be a nonzero element of D such that fD has prime radical. We consider when an integrally closed ring H between D and Df is determined locally by finitely many valuation overrings of D. We show such a local determination is equivalent to a statement about the exceptional prime divisors of normalized blow-ups of D and, when D is analytically normal, this property holds for D if and only if it holds for the completion of D. This latter fact, along with MacLane's notion of key polynomials, allows us to prove that in some central cases where D is a regular local ring and f is a regular parameter of D, then H is determined locally by a single valuation. As a consequence, we show that if H is also the integral closure of a finitely generated D-algebra, then the exceptional prime ideals of the extension H/D are comaximal. Geometrically, this translates into a statement about intersections of irreducible components in the closed fiber of the normalization of a proper birational morphism.
Foetal aortic valvuloplasty: experience of five cases
Authors: Marantz Pablo , Aiello Horacio , Grinenco Sofía , Izbizky Gustavo , Peña Gabriela , Trentacoste Luis , Granja Miguel , Otaño Lucas 
Published: February 2013

AbstractObjectivesFoetal aortic valvuloplasty has been proposed as a strategy to improve left heart growth and function in foetuses with severe aortic stenosis at risk of progression to hypoplastic left heart syndrome. We report our experience with this intervention.Methods and resultsBetween 2005 and 2010, five foetuses with aortic stenosis and at risk of progression to hypoplastic left heart syndrome underwent ultrasound-guided percutaneous foetal aortic valvuloplasty. There were no associated maternal complications or foetal demise. In one case, the pregnancy was terminated a couple of weeks after the intervention, one foetus evolved to hypoplastic left heart syndrome, and three did not.ConclusionsFoetal aortic valvuloplasty seems to be a safe and feasible procedure. It has been reported that it has the potential to prevent progression to hypoplastic left heart syndrome in selected foetuses with severe aortic stenosis. Further investigation regarding physiological and clinical aspects of this disease both prenatally and postnatally will probably allow to improve therapeutic strategies and clinical outcome.
Heart rate variability in β-thalassaemia major with or without cardiac siderosis
Authors: Alp A. , Ozdogan O. , Guloglu C.C. , Turker M. , Atabay B. 
Published: February 2013

AbstractObjectivesIron cardiomyopathy remains the major cause of death in β-thalassaemia major. Excessive iron loading could lead to cardiac dysfunction and arrhythmias. Reduced heart rate variability is associated with a higher risk of arrhythmia and sudden death after myocardial infarction and heart failure. Previous data have reported on reduced heart rate variability in patients with marked cardiac iron accumulation. In this study, we compared heart rate variability among β-thalassaemia major (TM) patients with or without cardiac siderosis.MethodsOut of 70 β-thalassaemia major patients with preserved ejection fractions, 38 patients with cardiac T2* magnetic resonance imaging assessment were included in our study. Time domain heart rate variability parameters were analysed from 24-hour recorded electrocardiograms and were compared with the control group.ResultsThe mean T2* magnetic resonance imaging value was 22.9 ± 13.3 (4.7–47.5). In 21 patients with β-thalassaemia major, the T2* magnetic resonance imaging values were greater than 20 ms and these patients were considered to be in the early stage of the disease. When we compare these patients with control subjects, the standard deviation of all NN intervals was still significantly lower (133.0 ± 32.2 versus 162.8 ± 32.9, p = 0.001) in β-thalassaemia major patients despite normal T2* magnetic resonance imaging values. On the contrary, the standard deviation of all NN intervals was not correlated with haemoglobin levels in these patients (p > 0.05).ConclusionsHeart rate variability parameters were reduced even in β-thalassaemia major patients without evident cardiac siderosis, as specified by magnetic resonance imaging data. The results of this study show that reduction of heart rate variability may start before cardiac iron loading is demonstrated by T2* magnetic resonance imaging in β-thalassaemia major.
Distress Tolerance and Perceived Barriers to Smoking Cessation
Authors: Kraemer Kristen M. , McLeish Alison C. , Jeffries Emily R. , Avallone Kimberly M. , Luberto Christina M. 
Published: February 2013

Background The present study examined the role of emotional distress tolerance (DT) in predicting barriers to smoking cessation and number of quit attempts. Methods The sample consisted of regular daily smokers ( N = 126; 37 females; M age = 36.51, SD = 13.05) who completed self-report measures on affect and smoking. Results After controlling for daily smoking rate and anxiety sensitivity, emotional DT significantly predicted internal barriers to cessation (6.9% unique variance) but not external or addiction-related barriers to cessation. Inconsistent with prediction, emotional DT did not significantly predict number of quit attempts. Conclusions These results suggest that individuals who are low in emotional DT believe that quitting smoking will be difficult because it takes away an important affect regulation strategy, and there may be utility in targeting emotional DT in smoking cessation interventions.
A Descriptive Study of Adverse Events from Clenbuterol Misuse and Abuse for Weight Loss and Bodybuilding
Authors: Spiller Henry A. , James Kyla J. , Scholzen Steven , Borys Douglas J. 
Published: February 2013

Background Clenbuterol is a β2-agonist approved in the United States for veterinary use in nonfood animals. Clenbuterol use is emerging among bodybuilders and fitness enthusiasts attracted to the hypertrophic and lipolytic effects. Cases This was a retrospective chart review of clenbuterol exposures reported to 2 poison control centers. Misuse of clenbuterol for weight loss and bodybuilding was reported in 11 of 13 clenbuterol users. Reported clinical effects included tachycardia, widened pulse pressure, tachypnea, hypokalemia, hyperglycemia, ST changes on electrocardiogram (ECG), elevated troponin, elevated creatine phosphokinase (CPK), palpitations, chest pain, and tremor. Measured serum clenbuterol concentration was 2983 pg/mL post 4.5 mg ingestion. Coingestants included T3 and anabolic steroids. Treatments included activated charcoal, benzodiazepines, β-blockers, potassium replacement, and intravenous (IV) fluid. Conclusions There is an increasing use of the Internet for illicit drug use for bodybuilding and weight loss purposes. These patients may not present as the stereotype of illicit drug abusers, but as healthy athletic low-risk patients. Clinical effects persisted greater than 24 hours with evidence of myocardial injury in 2 patients. Clenbuterol is increasingly being abused within the bodybuilding subculture. These cases illustrate the hidden dangers of clenbuterol abuse among bodybuilders and fitness enthusiasts.
High Serum Retinol and Lung Function in Young Patients With Cystic Fibrosis
Authors: Rivas‐Crespo M. Francisco , Jiménez David González , Acuña Quirós Maria D. , Aguirre Amaia Sojo , González Soledad Heredia , Díaz Martín Juan J. , Garagorri Otero Jesús M. , Almarza Aurora Lázaro , Bousoño‐García Carlos 
Published: February 2013

ABSTRACTObjective:The aim of the present study was to explore the relation between lung function and serum retinol (SR) in cystic fibrosis (CF) patients.Methods:This was a cross‐sectional study conducted in a group of 98 young patients with CF (6.8–22.3 years), after the exclusion of those with pulmonary exacerbation, vitamin A deficiency, or other risks, from an initial group of 124 cases.Results:Data of forced expiratory volume in 1 second (FEV1) were widely scattered (87.7% ± 16.9%). These were similar in the 78 pancreatic insufficient and 11 pancreatic sufficient patients. SR (56.6 ± 18.4 μg/dL) was >2.5th percentile of healthy people in the whole group, although 31 patients were situated above the 97.5th percentile (higher value: 110 μg/dL). The FEV1 was noticeably higher in these than in those within the normal range (93.6 ± 14.0 vs 85.0 ± 17.6 μg/dL; P < 0.05). The z score of SR correlated positively with FEV1 (r = 0.364; P = 0.000), after adjusting data for sex, age, body mass index, and pancreatic function. The odds ratio for a FEV1 >80% is 3.78 in patients with SR above the 97.5th percentile, versus only 0.26 in those within the normal range. There were no cases with retinol toxicity.Conclusions:FEV1 of young patients with CF correlates positively with SR, regardless of age, pancreatic function, or nutritional condition. Those with a moderately high retinol (up to 110 μg/dL) maintain the best respiratory function (FEV1 ≥80% in >90% of them) without any signs of toxicity.
Oral Health Status and Salivary Properties in Relation to Gluten‐free Diet in Children With Celiac Disease
Authors: Shteyer Eyal , Berson Tamar , Lachmanovitz Odelia , Hidas Ariela , Wilschanski Michael , Menachem Moti , Shachar Edna , Shapira Joseph , Steinberg Doron , Moskovitz Moti 
Published: February 2013

ABSTRACTBackground:Patients with celiac disease (CD) have a wide variety of symptoms, from being asymptomatic to having chronic diarrhea, abdominal pain, and extraintestinal symptoms. In the oral cavity, enamel defects and recurrent aphthous stomatitis are the most common symptoms. The aim of the study was to assess oral health, bacterial colonization and salivary buffering capacity of patients with CD at diagnosis were compared with patients with CD receiving a gluten‐free diet (GFD) and healthy children.Methods:Three groups were prospectively investigated: newly diagnosed CD, CD treated with GFD, and a control group. All of the children were examined by pediatric dentists, and saliva samples were collected for bacterial and pH analysis.Results:Ninety children were enrolled in the study, 30 in each group. A higher prevalence of enamel hypoplasia (66%) was found in children with CD. Plaque index was significantly lower in the celiac‐treated group, which correlated with oral health behavior: teeth brushing and frequency of eating between meals. Children receiving GFD brushed their teeth and used fluoride significantly more often than other children in the study. No difference between groups was found in snack consumption, mutans streptococci and lactobacilli counts in saliva, as well as pH and buffer capacity.Conclusions:A lower degree of plaque was found in children with CD receiving GFD. This finding could not be explained by salivary properties or bacteria, but rather by better oral hygiene. The results should raise the awareness of pediatric gastroenterologists toward oral health–related issues in children with CD.
Diagnostic Utility of Modified Gliadin Peptide Antibody Assays in New Zealand Children
Authors: Hope Benjamin C. , Ameratunga Rohan , Austin Paul M. , Evans Helen M. , MacFarlane Jeannette , Mouat Stephen , Chin Simon E. 
Published: February 2013

ABSTRACTObjective:The aim of the present study was to evaluate a panel of different antibody assays, including second‐generation antigliadin kits, in a local paediatric population thought to be at risk for coeliac disease (CD).Methods:Seventy‐nine children, who tested positive for immunoglobulin A (IgA) antibodies to tissue transglutaminase (TG), underwent duodenal biopsy. At endoscopy, serum was collected from all of the patients, and 9 different coeliac antibody assays were performed, both as isolated assays and in combination. These included immunoglobulin A (IgA) anti‐tissue transglutaminase (TGA), and IgA plus IgG anti‐deamidated gliadin peptide (DGPAG). A diagnosis of CD was made if the biopsies showed Marsh grade 3 lesions.Results:Twenty‐four of 79 children had CD confirmed histologically. Only 39 of 79 were positive for Inova TGA, and 35 of 79 were positive for Inova DGPAG. Twenty‐four of 39 who were TGA positive and 24 of 35 who were DGPAG positive had confirmed CD on biopsy. There was good correlation between TGA and DGPAG‐positive predictive values. None of the modified gliadin tests produced false‐negative results, and neither did the TGA.Conclusions:The Inova DGPAG and TGA assays have similar use in predicting CD in a selected paediatric population; however, in children who are positive for TGA when screened for CD, more than half have negative TGA serology when repeat testing is done at the time of biopsy. Those with persistent TGA positivity have only a 61.5% probability of having histologic CD, compared with 68.6% of those children positive for DGPAG.
Health Priorities in Adolescents With Inflammatory Bowel Disease
Authors: Cervesi Chiara , Battistutta Sara , Martelossi Stefano , Ronfani Luca , Ventura Alessandro 
Published: February 2013

ABSTRACTObjectives:Adolescence is a tough age for patients with inflammatory bowel disease (IBD) because they transition from child to adult medicine. Although a better understanding of the experience of illness and therefore a better response to the patient's needs have often been stressed, no studies have yet investigated the paediatricians' insight into their IBD adolescent patients.Methods:A group of adolescents (ages 12–19) diagnosed as having IBD was administered a questionnaire listing 22 items of concern. They were asked to rank each item on a 5‐point scale according to the degree of effect on the quality of their everyday life. The same questionnaire was administered to a group of paediatricians experienced in treating IBD and to a group of paediatric residents. Paediatricians and residents were asked to estimate how much each item would affect the quality of an average patient's life, according to the same scale. The questionnaire was also used in a face‐to‐face approach, asking a paediatrician to apply the estimation to an individual patient, instead of an average imaginary one.Results:Fifteen paediatric gastroenterologists, 11 paediatric residents, and 28 patients (female:male = 16:12; median age 16.3 years) took part in the study. The majority of patients experienced Crohn disease (17 vs 11 with ulcerative colitis). We found only 6 items overlapping when comparing the top 10 items ranked by patients and paediatricians. The patients' number 1 concern occupies the ninth position in the paediatricians' list. The number 1 item for paediatricians is not even mentioned in the patients' top 10 list. Overall, both paediatricians' and residents' rankings were significantly higher than those given by patients.Conclusions:We found a significant misalignment in the estimation of health concerns between IBD adolescent patients and their paediatricians. A better insight into IBD patients' worries and concerns is crucial for the improvement of the patient's quality of life and disease outcome.
Profiling Provider Outcome Quality for Pay‐for‐Performance in the Presence of Missing Data: A Simulation Approach
Authors: Ryan Andrew M. , Bao Yuhua 
Published: February 2013

ObjectiveProvider profiling of outcome performance has become increasingly common in pay‐for‐performance programs. For chronic conditions, a substantial proportion of patients eligible for outcome measures may be lost to follow‐up, potentially compromising outcome profiling. In the context of primary care depression treatment, we assess the implications of missing data for the accuracy of alternative approaches to provider outcome profiling.DataWe used data from the Improving Mood‐Promoting Access to Collaborative Treatment trial and the Depression Improvement across Minnesota, Offering a New Direction initiative to generate parameters for a Monte Carlo simulation experiment.Study DesignThe patient outcome of interest is the rate of remission of depressive symptoms at 6 months among a panel of patients with major depression at baseline. We considered two alternative approaches to profiling this outcome: (1) a relative, or tournament style threshold, set at the 80th percentile of remission rate among all providers, and (2) an absolute threshold, evaluating whether providers exceed a specified remission rate (30 percent). We performed a Monte Carlo simulation experiment to evaluate the total error rate (proportion of providers who were incorrectly classified) under each profiling approach. The total error rate was partitioned into error from random sampling variability and error resulting from missing data. We then evaluated the accuracy of alternative profiling approaches under different assumptions about the relationship between missing data and depression remission.Principal FindingsOver a range of scenarios, relative profiling approaches had total error rates that were approximately 20 percent lower than absolute profiling approaches, and error due to missing data was approximately 50 percent lower for relative profiling. Most of the profiling error in the simulations was a result of random sampling variability, not missing data: between 11 and 21 percent of total error was attributable to missing data for relative profiling, while between 16 and 33 percent of total error was attributable to missing data for absolute profiling. Finally, compared with relative profiling, absolute profiling was much more sensitive to missing data that was correlated with the remission outcome.ConclusionsRelative profiling approaches for pay‐for‐performance were more accurate and more robust to missing data than absolute profiling approaches.
Stock weighting and nontrading bias in estimated portfolio returns
Authors: Gray Philip 
Published: February 2013

AbstractLiu and Strong (2008) note that researchers often employ a simple (but incorrect) averaging approach that induces significant error into estimated buy‐and‐hold portfolio returns. This study explores the additional challenges that arise when stocks are subject to nontrading. We develop a decomposition of the total bias in estimated return into the components attributable to the stock weighting approach and the treatment of nontrading. While the latter is shown to be negligible, the former can approach 150 basis points per month. Our empirical analysis of Australian equities shows that the simple averaging approach tends to overstate the size and book‐to‐market effects, and understate the momentum effect.
Induced abortion and breast cancer among parous women: a Danish cohort study
Authors: Braüner Christina Marie , Overvad Kim , Tjønneland Anne , Attermann Jørn 
Published: February 2013

AbstractObjectiveWe investigated whether induced abortion is associated with breast cancer when lifestyle confounders, including smoking and alcohol consumption, are adjusted for. Design. Prospective cohort study.SettingDanish women from the Diet, Cancer and Health study.PopulationA total of 25 576 women.MethodsWe obtained exposure data from baseline questionnaires filled in by the women between 1993 and 1997. Information on breast cancer and emigration was retrieved from Danish national registries. The study power was approximately 85% when applying a minimum detection hazard ratio of 1.2.Main outcome measuresLong‐term effects of induced abortion on the risk of breast cancer among women above 50 years of age.ResultsDuring a follow up of approximately 12 years, 1215 women were diagnosed with breast cancer. When comparing parous women who had an abortion with parous women who never had an abortion, there was no association between breast cancer risk and induced abortion (ever vs. never), with a hazard ratio 0.95 (95% confidence interval 0.83–1.09), regardless of whether the abortion occurred before the first birth (hazard ratio 0.86; 95% confidence interval 0.65–1.14), or after the first birth (hazard ratio 0.97; 95% confidence interval 0.84–1.13).ConclusionsOur study did not show evidence of an association between induced abortion and breast cancer risk.