bluuebunny/crossref_metadata_2025_split huggingface dataset:
Board examination stress effect on diastolic function
Authors: Geraiely Babak , Tavoosi Anahita , Sattarzadeh Roya , Hassanbeigi Hamidreza , Larry Mehrdad 
Published: November 2018

AbstractBackgroundTo this date, effects of mental stress on cardiac function have not been clearly investigated. Although hemodynamic and neuroendocrine adverse effects of daily mental stress on cardiovascular morbidity and mortality have been reported, its direct impact on diastolic function of the heart has not been previously studied. In this study, we aimed to assess the role of Board Exam anxiety on right and left ventricular diastolic function in medical residents.MethodsForty medical residents prior to participation in the medical board exam were enrolled in our study. Right prior to as well as 2 month after the exam, all residents underwent trans‐thoracic Doppler echocardiography. Right ventricular systolic and diastolic functions and echocardiography indices were measured. Levels of anxiety were measured using Beck Anxiety Inventory Questionnaire before and after the exam. Pre exam and post exam results of study population as well as low and high anxiety groups were evaluated.ResultsEarly to late mitral inflow velocity (E/A ratio) in LV inflow increased after board exam (P‐value <.001). E/A ratio in RV inflow increased after board exam (P‐value: .002). Early mitral inflow to its annular velocity (E/E’ ratio) in septal wall decreased after board exam (P‐value<.001). The change in E/E′ RV free wall did not reach statistical significance (P = .57). Mitral annuls velocities measured by TDI in septal and lateral wall and also tricuspid annulus velocity increased after board exam (P‐value<.05). The comparison of these changes between the high‐stress and low‐stress groups of residents revealed significant differences. Comparison of changes of E/A ratio in the mitral and tricuspid inflow as well as the E/E’ in the septum and free wall of the right ventricle before and after the Board Exam between high‐stress and low‐stress groups was not statistically significant, although there was a trend of more changes in high‐ stress group residents.ConclusionThis is the first report of comprehensive sequential assessment of left and right ventricular diastolic functions during and after a real subacute stress occasion. The finding of a decreased E/A and E′ in response to mental stress suggests that repetitive mental stress may induce diastolic dysfunction which is a mechanism of diastolic heart failure in individuals at risk.
Predicting agronomical and ecological effects of shifting from sheep to cattle grazing in highly dynamic Mediterranean dry grasslands
Authors: Faria Nuno 
Published: November 2018

AbstractIn the recent decades, cattle numbers strongly increased whereas sheep numbers decreased in south Portugal. This paper aims to predict the potential agronomical and ecological effects of these trends and clarify about the versatility of cattle and sheep systems in adapting to climate changes in the Mediterranean basin. We monitored livestock management in the dry grasslands of Évora (2012 to 2016) and investigated for the effect of livestock type (TLivest) on (a) sward's characteristics, (b) vegetation taxonomic diversity, and (c) in conforming vegetation communities and promoting species of agronomical interests (SAIs). Generalized linear mixed models were used to link management descriptors and vegetation parameters with TLivest. Redundancy analysis was used to analyse the changes due to TLivest on floristic composition and SAIs. Sheep fields presented (a) higher number of days under grazing and lower instantaneous stocking rates than cattle or mixed fields and (b) lower vegetation height in April in wet years and higher green vegetation cover in May; α‐ and γ‐diversity were poorly related with TLivest, but β‐diversity was lower under mixed grazing than under sheep or cattle grazing. The highest richness of legume species was found in permanent grasslands grazed by sheep. Redundancy analysis provided a good discrimination of TLivest but a poor segregation of vegetation communities. As a conclusion, sheep grazing can be seen as a more powerful tool to increase sward heterogeneity, and thus, a loss of grassland heterogeneity can be expected under cattle grazing. The lower versatility of cattle systems suggests narrower opportunities in adapting to climate change.
Life span pigmentation changes of the substantia nigra detected by neuromelanin‐sensitive MRI
Authors: Xing Yue , Sapuan Abdul , Dineen Rob A. , Auer Dorothee P. 
Published: November 2018

AbstractBackground: Neuromelanin is a pigment with strong iron‐chelating properties preferentially found in dopaminergic neurons of the substantia nigra pars compacta (SNpc). Parkinson's disease is characterized by pronounced, MRI‐detectable neuromelanin loss, but the neuroprotective or neurotoxic role of neuromelanin remains debated. Histological studies have demonstrated neuromelanin increases with age, but this has not been confirmed in vivo, and there is uncertainty whether neuromelanin declines, stabilizes, or increases from middle age.Methods: This study aimed to establish physiological changes of pigmentation of the SNpc using a pooled data set of neuromelanin‐sensitive 3T MRI from 134 healthy individuals aged 5‐83 years. Neuromelanin‐related brightness (regional contrast to ratio) and calibrated hyperintense volumes were analyzed using linear and nonlinear regression models to characterize age effects. Laterality, sex, and subregional effects were also assessed.Results: For brightness, age effects were best described as a quadratic trajectory explaining 81.5% of the observed variance in the SNpc showing a strong increase from childhood to adolescence, with plateauing in middle age and a decline in older age. Similar but less pronounced effects were seen in hyperintense volumes. We also show an anterior‐posterior gradient in SNpc contrast, larger normalized neuromelanin‐rich volume in women > 47 years old, but no laterality effect.Conclusions: Using optimized neuromelanin MRI in a life span sample, we demonstrate a strong age effect with inverted U‐shaped SNpc pigmentation‐related contrast from childhood to old age. This age trajectory of physiological SNpc pigmentation needs to be taken into account for diagnostic applications of depigmentation. The study also paves the way for systematic investigations of the mechanisms of neuromelanin in healthy and pathological brain development and aging. © 2018 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society.
Radiobiological issues in prospective carbon ion therapy trials
Authors: Fossati Piero , Matsufuji Naruhiro , Kamada Tadashi , Karger Christian P. 
Published: November 2018

Carbon ion radiotherapy (CIRT) is developing toward a versatile tool in radiotherapy; however, the increased relative biological effectiveness (RBE) of carbon ions in tumors and normal tissues with respect to photon irradiation has to be considered by mathematical models in treatment planning. As a consequence, dose prescription and definition of dose constraints are performed in terms of RBE weighted rather than absorbed dose. The RBE is a complex quantity, which depends on physical variables, such as dose and beam quality as well as on normal tissue‐ or tumor‐specific factors. At present, three RBE models are employed in CIRT: (a) the mixed‐beam model, (b) the Microdosimetric Kinetic Model (MKM), and (c) the local effect model. While the LEM is used in Europe, the other two models are employed in Japan, and unfortunately, the concepts of how the nominal RBE‐weighted dose is determined and prescribed differ significantly between the European and Japanese centers complicating the comparison, transfer, and reproduction of clinical results. This has severe impact on the way treatments should be prescribed, recorded, and reported. This contribution reviews the concept of the clinical application of the different RBE models and the ongoing clinical CIRT trials in Japan and Europe. Limitations of the RBE models and the resulting radiobiological issues in clinical CIRT trials are discussed in the context of current clinical evidence and future challenges.
A spectral method for solving heat and moisture transfer through consolidated porous media
Authors: Gasparin Suelen , Dutykh Denys , Mendes Nathan 
Published: November 2018

SummaryThis work presents an efficient numerical method based on spectral expansions for simulation of heat and moisture diffusive transfers through multilayered porous materials. Traditionally, by using the finite‐difference approach, the problem is discretized in time and space domains (method of lines) to obtain a large system of coupled ordinary differential equations (ODEs), which is computationally expensive. To avoid such a cost, this paper proposes a reduced‐order method that is faster and accurate, using a much smaller system of ODEs. To demonstrate the benefits of this approach, three case studies are presented. The first one considers nonlinear heat and moisture transfer through one material layer. The second case, ie, highly nonlinear, imposes a high moisture content gradient, simulating a rain‐like condition, over a two‐layered domain, whereas the last one compares the numerical prediction against experimental data for validation purposes. Results show how the nonlinearities and the interface between materials are easily and naturally treated with the spectral reduced‐order method. Concerning the reliability part, predictions show a good agreement with experimental results, which confirm robustness, calculation efficiency, and high accuracy of the proposed approach for predicting the coupled heat and moisture transfer through porous materials.
Effectiveness of a Total Meal Replacement Program (OPTIFAST Program) on Weight Loss: Results from the OPTIWIN Study
Authors: Ard Jamy D. , Lewis Kristina H. , Rothberg Amy , Auriemma Anthony , Coburn Sally L. , Cohen Sarah S. , Loper Judy , Matarese Laura , Pories Walter J. , Periman Seletha 
Published: November 2018

ObjectiveThe aim of this study was to test the effectiveness of the OPTIFAST program (OP), a total meal replacement dietary intervention, compared with a food‐based (FB) dietary plan for weight loss.MethodsParticipants with BMI 30 to 55 kg/m2, age 18 to 70 years old, were randomized to OP or FB dietary and lifestyle interventions for 26 weeks, followed by a weight‐maintenance phase. Outcomes were percent change in body weight (%WL) from baseline to weeks 26 and 52, associated changes in body composition (using dual energy x‐ray absorptiometry), and adverse events. Primary analysis used repeated‐measures multivariable linear mixed models to compare outcomes between groups in a modified intention‐to‐treat fashion (mITT).ResultsA total of 273 participants (83% of randomized; 135 OP, 138 FB) made up the mITT population. Mean age was 47.1 ± 11.2 years; 82% were female and 71% non‐Hispanic white. Baseline BMI was 38.8 ± 5.9 kg/m2. At 26 weeks, OP %WL was 12.4% ± 0.6% versus 6.0% ± 0.6% in FB (P < 0.001). At 52 weeks, OP %WL was 10.5% ± 0.6% versus 5.5% ± 0.6% in FB (P < 0.001). Fat mass loss was greater for OP; lean mass loss was proportional to total weight loss. There was no difference in serious adverse event rates between groups.ConclusionsCompared with an FB approach, OP was more effective with greater sustained weight loss.
Intensive Behavioral Therapy for Obesity Combined with Liraglutide 3.0 mg: A Randomized Controlled Trial
Authors: Wadden Thomas A. , Walsh Olivia A. , Berkowitz Robert I. , Chao Ariana M. , Alamuddin Naji , Gruber Kathryn , Leonard Sharon , Mugler Kimberly , Bakizada Zayna , Tronieri Jena Shaw 
Published: November 2018

ObjectiveThe Centers for Medicare and Medicaid Services (CMS) covers intensive behavioral therapy (IBT) for obesity. The efficacy, however, of the specific approach has never been evaluated in a randomized trial, as described here. The 1‐year trial also assessed whether the addition to IBT of liraglutide 3.0 mg would significantly increase weight loss and whether the provision of meal replacements would add further benefit.MethodsA total of 150 adults with obesity were randomly assigned to: IBT (IBT‐alone), providing 21 counseling visits; IBT combined with liraglutide (IBT‐liraglutide); or IBT‐liraglutide combined for 12 weeks with a 1,000‐ to 1,200‐kcal/d meal‐replacement diet (Multicomponent). All participants received weekly IBT visits in month 1, every‐other‐week visits in months 2 to 6, and monthly sessions thereafter.ResultsNinety‐one percent of participants completed 1 year, at which time mean (± SEM) losses for IBT‐alone, IBT‐liraglutide, and Muticomponent participants were 6.1 ± 1.3%, 11.5 ± 1.3%, and 11.8 ± 1.3% of baseline weight, respectively. Fully 44.0%, 70.0%, and 74.0% of these participants lost ≥ 5% of weight, respectively. The liraglutide‐treated groups were superior to IBT‐alone on both outcomes. Weight loss in all three groups was associated with clinically meaningful improvements in cardiometabolic risk factors.ConclusionsThe findings demonstrate the efficacy of IBT for obesity and the potential benefit of adding pharmacotherapy to this approach.
Overall and cause‐specific mortality in the Sentinel system: A power analysis
Authors: Swain Richard S. , Taylor Lockwood G. , Woodworth Tiffany S. , Fuller Candace C. , Petrone Andrew B. , Menzin Talia J. , Haug Nicole R. , Toh Sengwee , Mosholder Andrew D. 
Published: November 2018

AbstractPurposeMortality data within the Sentinel Death Tables remain generally uncharacterized. Assessment of mortality data within Sentinel will help inform its utility for medical product safety studies.MethodsTo determine if Sentinel contains sufficient all‐cause and cause‐specific mortality events to power postmarketing safety studies.We calculated crude rates of all‐cause mortality and suicide and proportional mortality from suicide from 2004 to 2012 in seven Sentinel data partners. Results were stratified by data partner, sex, age group, and calendar year and compared with national estimates from Centers for Disease Control and Prevention Wide‐ranging ONline Data for Epidemiologic Research. We performed sample size estimations for all‐cause mortality and 10 leading causes of death.ResultsWe observed 479 694 deaths, including 5811 suicides, during 68 million person‐years of follow‐up. Pooled mean death and suicide rates in the data partners were 710 and 8.6 per 100 000 person‐years, respectively (vs 810 and 11.8 nationally). The mean proportional mortality from suicide among the data partners was 1.2%, compared with 1.5% nationally. National trends of decreasing overall mortality and increasing proportional mortality for suicide were reflected within Sentinel. We estimated that detecting hazard ratios of 1.25 and 3 would require 16 442 and 460 exposed patients, respectively, for overall mortality, and 1.3 million and 37 411, respectively, for suicide.ConclusionsThis was the first study to investigate mortality data in the Sentinel death tables. We found that all‐cause mortality appeared well powered for use as a safety outcome and cause‐specific mortality outcomes may be adequately powered in certain circumstances. Further investigation into the quality of the Sentinel death data is needed.
Effect of puerarin on melanogenesis in human melanocytes and vitiligo mouse models and the underlying mechanism
Authors: Ding Xiaoxia , Mei Enci , Hu Murong , Zhou Chaofeng , Li Xiaobin , Cai Lei , Li Zhiming 
Published: November 2018

Puerarin is the major bioactive ingredient derived from the root of thePueraria lobata(Willd.), and its antioxidative stress effects have been demonstrated in several previous studies. Moreover, Puerarin can upregulate melanin synthesis and microphthalmia‐associated transcription factor (MITF) transcription by increasing cAMP level of intracellular cyclic adenosine monophosphate. Vitiligo is an acquired cutaneous disorder of pigmentation, and the pathogenesis has remained elusive. Current treatment modalities are directed towards achieving repigmentation. In this study, we found that after treating with puerarin at various concentrations of 40 μmol/L, the melanin content of human melanocytes increased significantly and the apparent level of protein and the RNA levels of MITF, tyrosinase (TYR), and tyrosinase‐related protein 1 (TRP‐1) were also increased. Further, puerarin was shown to inhibit phosphorylation and activation of extracellular signal‐regulated kinase 1 and 2 (ERK1/2) without significantly affecting p38 and c‐Jun N‐terminal kinase phosphorylation. These results demonstrated that puerarin stimulated melanogenesis in human melanocytes via inhibition of ERK1/2 signaling pathways, which leads to upregulation of MITF and TYR as well as TRP‐1 subsequently. Additionally, mice vitiligo models with puerarin treatment showed lighter pathological changes. Therefore, we suggested that puerarin might be a potential medicine for vitiligo.
The effects of solution additives and gas‐phase modifiers on the molecular environment and conformational space of common heme proteins
Authors: Butcher David , Miksovska Jaroslava , Ridgeway Mark E. , Park Melvin A. , Fernandez‐Lima Francisco 
Published: November 2018

RationaleThe molecular environment is known to impact the secondary and tertiary structures of biomolecules both in solution and in the gas phase, shifting the equilibrium between different conformational and oligomerization states. However, there is a lack of studies monitoring the impacts of solution additives and gas‐phase modifiers on biomolecules characterized using ion mobility techniques.MethodsThe effect of solution additives and gas‐phase modifiers on the molecular environment of two common heme proteins, bovine cytochrome c and equine myoglobin, is investigated as a function of the time after desolvation (e.g., 100–500 ms) using nanoelectrospray ionization coupled to trapped ion mobility spectrometry with detection by time‐of‐flight mass spectrometry. Organic compounds used as additives/modifiers (methanol, acetonitrile, acetone) were either added to the aqueous protein solution before ionization or added to the ion mobility bath gas by nebulization.ResultsChanges in the mobility profiles are observed depending on the starting solution composition (i.e., in aqueous solution at neutral pH or in the presence of organic content: methanol, acetone, or acetonitrile) and the protein. In the presence of gas‐phase modifiers (i.e., N2doped with methanol, acetone, or acetonitrile), a shift in the mobility profiles driven by the gas‐modifier mass and size and changes in the relative abundances and number of IMS bands are observed.ConclusionsWe attribute the observed changes in the mobility profiles in the presence of gas‐phase modifiers to a clustering/declustering mechanism by which organic molecules adsorb to the protein ion surface and lower energetic barriers for interconversion between conformational states, thus redefining the free energy landscape and equilibria between conformers. These structural biology experiments open new avenues for manipulation and interrogation of biomolecules in the gas phase with the potential to emulate a large suite of solution conditions, ultimately including conditions that more accurately reflect a variety of intracellular environments.
Effects of soil‐bound water exchange on the recovery of spike water by cryogenic water extraction
Authors: Thielemann Lukas , Gerjets Rowena , Dyckmans Jens 
Published: November 2018

RationaleThe effects that alter the isotopic composition of water added to soil samples that have been oven‐dried previously are not fully understood.MethodsOven‐dried clay‐rich soil was repeatedly rewetted with two waters of strongly differing isotopic composition. This approach allowed the determination of the amount and the isotopic composition of soil‐bound water that exchanges with spike water after rewetting.ResultsAfter oven drying, 1.8% and 1.4% water (gravimetric content) exchanged with the added spike water, for δ2H and δ18O values, respectively. The isotopic composition of this soil residual water was depleted by 89.7 mUr and 5.42 mUr relative to the water extracted from field‐fresh soil for H and O, respectively. The cryogenic extraction method was more efficient than oven drying in terms of water removal from soil.ConclusionsOur results show that the isotopic difference between extractable (mobile) water and non‐extractable (soil‐bound) water explains the isotopic effects observed in spike water experiments. This difference, however, can also lead to a considerable isotopic offset between extractable and total soil water.
Surface modification and characterization of carbon black through oxidation
Authors: Liu Chia Y. , Cheng Wen T. 
Published: November 2018

This study focuses on modifying the surface of carbon black (CB) with hydrogen peroxide to raise light absorbance of dispersed CB in water without capping agent. Four kinds of commercial CB, trademarked as M900, M1000, M1100, and Mogul L, respectively, were used as study materials. The ultrasonic bath was utilized to disperse the treated CB in de‐ionic (DI) water in the absence of capping agent. The surface properties of treated CB were characterized by thermal gravimetric analysis, X‐ray photoelectron spectroscope, and Fourier transform infrared spectroscopy, as well as the light absorbance, stability, and morphology of treated CB particles dispersed in DI water were analyzed by ultraviolet‐visible light absorption spectroscopy, dynamic light scattering, and transmission electron microscopy. As shown in the results, in particular, it was found that the oxygen on the surface of CB could be increased by the treatment of peroxide hydrogen, resulting in stable dispersion without capping agent to sharply increase light absorption value of Mogul L CB in DI water from 38 to 545 g−1 dm2.
Facile One‐Step Synthesis of Polyoxazoline‐Coated Iron Oxide Nanoparticles
Authors: Venturini Pierre , Fleutot Solenne , Cleymand Franck , Hauet Thomas , Dupin Jean‐Charles , Ghanbaja Jaafar , Martinez Hervé , Robin Jean‐Jacques , Lapinte Vincent 
Published: November 2018

AbstractHereby, a facile one step synthesis of polyoxazoline coated Superparamagnetic Iron Oxide Nanoparticles is reported. The functionalization efficiency is demonstrated using several complementary techniques including direct High Resolution‐Transmission Electron Microscopy observations of the polyoxazoline layer. The hybrid nanoparticles have a spinel Fd‐3 m structure, a mean particle size of around 12 nm and a high saturation magnetization of 72 emu/g.
Pyrenylthioureayl Alanine as a Switch‐On Fluorescent Sensor for Hg(II) Ions
Authors: Bag Subhendu Sekhar , De Suranjan 
Published: November 2018

AbstractFluorescence sensing of heavy metal ion such as mercury is highly important because of its adverse effects on biological systems and on environment. Toward this end, we report herein a new and novel pyrenylthioureayl alanine amino acid (1,PyTUAla) as an efficient switch‐on fluorescent sensor for sensing of Hg2+ion in semi‐aqueous solvent system (7:3 H2O:ACN). The probe also shows binding interaction with Cu2+ion with an enhancement of emission. In both the cases 1:2 metal‐ligand binding stoichiometry is evident from Job's plot analyses. The detection limit is found to be 93 nM with a very high association (1010 M−1) constant for Hg2+ion. The UV‐visible absorption, IR‐spectroscopic study, NMR titration, and a theoretical calculation supported the probe's binding to Hg2+ion through the coordination with two sulphur atoms of two iminothioureayl moieties of two pyrenylthioureayl alanines.