bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fully automated segmentation of the left atrium, pulmonary veins, and left atrial appendage from magnetic resonance angiography by joint‐atlas‐optimization
Authors: Qiao Menyun , Wang Yuanyuan , Berendsen Floris F. , van der Geest Rob J. , Tao Qian 
Published: March 2019

PurposeAtrial fibrillation (AF) originating from the left atrium (LA) and pulmonary veins (PVs) is the most prevalent cardiac electrophysiological disorder. Accurate segmentation and quantification of the LA chamber, PVs, and left atrial appendage (LAA) provides clinically important references for treatment of AF patients. The purpose of this work is to realize objective segmentation of the LA chamber, PVs, and LAA in an accurate and fully automated manner.MethodsIn this work, we proposed a new approach, named joint‐atlas‐optimization, to segment the LA chamber, PVs, and LAA from magnetic resonance angiography (MRA) images. We formulated the segmentation as a single registration problem between the given image and all N atlas images, instead of N separate registration between the given image and an individual atlas image. Level sets was applied to refine the atlas‐based segmentation. Using the publically available LA benchmark database, we compared the proposed joint‐atlas‐optimization approach to the conventional pairwise atlas approach and evaluated the segmentation performance in terms of Dice index and surface‐to‐surface (S2S) distance to the manual ground truth.ResultsThe proposed joint‐atlas‐optimization method showed systemically improved accuracy and robustness over the pairwise atlas approach. The Dice of LA segmentation using joint‐atlas‐optimization was 0.93 ± 0.04, compared to 0.91 ± 0.04 by the pairwise approach (P < 0.05). The mean S2S distance was 1.52 ± 0.58 mm, compared to 1.83 ± 0.75 mm (P < 0.05). In particular, it produced significantly improved segmentation accuracy of the LAA and PVs, the small distant part in LA geometry that is intrinsically difficult to segment using the conventional pairwise approach. The Dice of PVs segmentation was 0.69 ± 0.16, compared to 0.49 ± 0.15 (P < 0.001). The Dice of LAA segmentation was 0.91 ± 0.03, compared to 0.88 ± 0.05 (P < 0.01).ConclusionThe proposed joint‐atlas optimization method can segment the complex LA geometry in a fully automated manner. Compared to the conventional atlas approach in a pairwise manner, our method improves the performance on small distal parts of LA, for example, PVs and LAA, the geometrical and quantitative assessment of which is clinically interesting.
T2 measurement and quantification of cerebral white and gray matter aspartate concentrations in vivo at 3T: a MEGA‐PRESS study
Authors: Menshchikov Petr , Manzhurtsev Andrei , Ublinskiy Maxim , Akhadov Tolib , Semenova Natalia 
Published: March 2019

PurposeTo measure the transverse relaxation rate (T2) of aspartate (Asp) from Asp‐edited MEGA‐PRESS spectra and use the measured T2 values to estimate the Asp concentrations in gray matter (GM)‐ and white matter (WM)‐dominant brain regions.MethodsSince Asp‐edited MEGA‐PRESS spectra contain non‐overlapped Asp signals, TE‐dependence arising from J‐evolution can be considered using phantom MEGA‐PRESS spectra acquired with the same parameters as in vivo spectra. Four TE values (90, 115, 140, and 150 ms) were selected from numeric analyses for effective detection of the edited Asp multiplet at ~2.71 ppm. The T2 relaxation time was measured in the anterior cingulate cortex (ACC) of 16 healthy volunteers. Absolute cerebral Asp concentrations were measured with Asp‐edited MEGA‐PRESS in the ACC and left centrum semiovale (CS) of 44 healthy volunteers at TEs of 90, 115, 140, and 150 ms.ResultsThe in vivo and phantom T2 values of the edited Asp signals were 165 ± 37 ms and 313 ± 27 ms, respectively. The cortical GM concentration quantified was significantly greater than the WM concentration (2.80 ± 0.31 mM vs. 1.01 ± 0.18 mM).ConclusionMEGA‐PRESS is the most common editing method used for low‐concentration metabolites detection. Estimation of the absolute Asp concentrations has potential in many research applications, such as studying the processes underlying the reduction of N‐acetyl aspartate as well as studying mitochondrial diseases etc. The T2 measurement method described has been successfully applied for edited Asp signals. This method can also be used for other strongly J‐coupled signals.
MANTIS: Model‐Augmented Neural neTwork with Incoherent k‐space Sampling for efficient MR parameter mapping
Authors: Liu Fang , Feng Li , Kijowski Richard 
Published: March 2019

PurposeTo develop and evaluate a novel deep learning‐based image reconstruction approach called MANTIS (Model‐Augmented Neural neTwork with Incoherent k‐space Sampling) for efficient MR parameter mapping.MethodsMANTIS combines end‐to‐end convolutional neural network (CNN) mapping, incoherent k‐space undersampling, and a physical model as a synergistic framework. The CNN mapping directly converts a series of undersampled images straight into MR parameter maps using supervised training. Signal model fidelity is enforced by adding a pathway between the undersampled k‐space and estimated parameter maps to ensure that the parameter maps produced synthesized k‐space consistent with the acquired undersampling measurements. The MANTIS framework was evaluated on the T2 mapping of the knee at different acceleration rates and was compared with 2 other CNN mapping methods and conventional sparsity‐based iterative reconstruction approaches. Global quantitative assessment and regional T2 analysis for the cartilage and meniscus were performed to demonstrate the reconstruction performance of MANTIS.ResultsMANTIS achieved high‐quality T2 mapping at both moderate (R = 5) and high (R = 8) acceleration rates. Compared to conventional reconstruction approaches that exploited image sparsity, MANTIS yielded lower errors (normalized root mean square error of 6.1% for R = 5 and 7.1% for R = 8) and higher similarity (structural similarity index of 86.2% at R = 5 and 82.1% at R = 8) to the reference in the T2 estimation. MANTIS also achieved superior performance compared to direct CNN mapping and a 2‐step CNN method.ConclusionThe MANTIS framework, with a combination of end‐to‐end CNN mapping, signal model‐augmented data consistency, and incoherent k‐space sampling, is a promising approach for efficient and robust estimation of quantitative MR parameters.
Spectral condition‐number estimation of large sparse matrices
Authors: Avron Haim , Druinsky Alex , Toledo Sivan 
Published: March 2019

SummaryWe describe a randomized Krylov‐subspace method for estimating the spectral condition number of a real matrix A or indicating that it is numerically rank deficient. The main difficulty in estimating the condition number is the estimation of the smallest singular value
of A. Our method estimates this value by solving a consistent linear least squares problem with a known solution using a specific Krylov‐subspace method called LSQR. In this method, the forward error tends to concentrate in the direction of a right singular vector corresponding to
. Extensive experiments show that the method is able to estimate well the condition number of a wide array of matrices. It can sometimes estimate the condition number when running dense singular value decomposition would be impractical due to the computational cost or the memory requirements. The method uses very little memory (it inherits this property from LSQR), and it works equally well on square and rectangular matrices.
Leisure‐Time Sedentary Behavior and Obesity Among 116,762 Adolescents Aged 12‐15 Years from 41 Low‐ and Middle‐Income Countries
Authors: Ashdown‐Franks Garcia , Vancampfort Davy , Firth Joseph , Veronese Nicola , Jackson Sarah E. , Smith Lee , Stubbs Brendon , Koyanagi Ai 
Published: March 2019

ObjectiveRates of adolescent obesity are increasing worldwide, with steeper increases being observed in low‐ and middle‐income countries (LMICs). Sedentary behavior (SB) has been associated with various physical and mental health conditions. Little is known about the association between SB and obesity among adolescents in LMICs. This cross‐sectional study explored the associations between SB and obesity in adolescents from 41 LMICs.MethodsObesity was measured using BMI; SB was assessed through self‐report and was considered for all times except when subjects were at school or doing homework.ResultsData from the Global School‐based Student Health Survey were analyzed in 116,762 adolescents (mean [SD] age 13.8 [1.0] years; 48.6% female). The overall prevalence of obesity was 4%, and the prevalence of ≥ 3 h/d of SB was 26%. The prevalence of obesity and SB were lowest in low‐income countries and highest in upper‐middle‐income countries. SB for ≥ 3 h/d was associated with higher odds of obesity in 32 countries. This relationship was strongest among low‐income countries.ConclusionsBeing sedentary for ≥ 3 h/d is associated with increased odds of obesity in adolescence. Future longitudinal data are required to confirm these findings and to inform interventions targeting SB among adolescents in LMICs, thereby reducing the prevalence of obesity.
Searching for calcium antagonists for hypertension disease therapy from Moutan Cortex, using bioactivity integrated UHPLC‐QTOF‐MS
Authors: Lu Yujie , Deng Yanfang , Liu Wenjuan , Jiang Min , Bai Gang 
Published: March 2019

AbstractIntroductionCalcium channel blockers (CCBs) are currently the most commonly used drugs for the treatment of hypertension. Moutan Cortex (MC), a traditional Chinese herb, has been found to have an anti‐hypertensive effect. However, its potential mechanisms in the regulation of intracellular calcium concentration ([Ca2+]i) remain poorly understood.ObjectiveThe main objective of this work was to identify the potential calcium antagonists from MC and study their molecular mechanisms.MethodsUltra‐high performance liquid chromatography‐quadrupole‐time‐of‐fight‐mass spectrometry (UHPLC‐QTOF‐MS) analysis combined with a dual‐luciferase reporter assay was utilised to systematically screen the calcium antagonistic active ingredients in the methanol extract of MC. Additionally, the molecular mechanism of these compounds was further studied using live‐cell imaging analysis with the calcium ion (Ca2+) probe dye fluo‐4/AM to monitor changes in [Ca2+]i.ResultsThree monoterpenoids (paeoniflorin, benzoylpaeoniflorin and mudanpioside C), one phenolic acid (paeonol) and one gallotannin (1,2,3,4,6‐O‐pentagalloylglucose) were screened out as potential calcium antagonists in MC. Among them, the calcium antagonistic activity of benzoylpaeoniflorin, mudanpioside C and 1,2,3,4,6‐O‐pentagalloylglucose is first reported. Additionally, paeoniflorin, benzoylpaeoniflorin, mudanpioside C and paeonol can effectively block voltage‐operated Ca2+ channels (VOCCs) to exert calcium antagonism, while 1,2,3,4,6‐O‐pentagalloylglucose plays a role in blocking inositol 1,4,5‐trisphosphate receptors (IP3Rs).ConclusionThis work indicated that the anti‐hypertensive efficacy of MC acted through multiple components selectively antagonising multiple cell signalling pathways to regulate [Ca2+]i. Furthermore, they could be considered as a reference standard for controlling the quality of Chinese medicinal materials.
Industrial Blue Diode Laser Breaks 1 kW Barrier
Authors: Britten Simon , Krause Volker 
Published: March 2019

AbstractUp to now, infrared lasers have been largely established for the welding of copper, due to the unavailability of alternative continuous‐wave laser sources with a lower wavelength. Despite the low absorption of the wavelength 1 μm on copper, conventional melting by evaporation is possible when using high laser intensities. But especially with thin components, this approach reaches its limits, and only deep penetration welding can be achieved. Laserline's 450 nm diode laser closes this gap and enables process‐reliable heat conduction welding with 1 kW of laser power. The new laser system scores with an unprecedented process stability and new application possibilities.
A mass participatory experiment provides a rich temporal profile of temperature response in spring onions
Authors: Brestovitsky Anna , Ezer Daphne 
Published: March 2019

AbstractPlants modulate their growth rates based on the environmental signals; however, it is difficult to experimentally test how natural temperature and light fluctuations affect growth, since realistic outdoor environments are difficult to replicate in controlled laboratory conditions, and it is expensive to conduct experiments in many environmentally diverse regions. In partnership with BBC Terrific Scientific, over 50 primary schools from around the UK grew spring onions outside of hydroponic growth chambers that they constructed. Over 2 weeks, students measured the height of the spring onions daily, while the hourly temperature and visibility data were determined for each school based on the UK Meteorological Office data. This rich time series data allowed us to model how plants integrate temperature and light signals to determine how much to grow, using techniques from functional data analysis. We determined that under nutrient‐poor hydroponic conditions, growth of spring onion is sensitive to even a few degrees change in temperature, and is most correlated with warm nighttime temperatures, high temperatures at the start of the experiment, and light exposure near the end of the experiment. We show that scientists can leverage schools to conduct experiments that leverage natural environmental variability to develop complex models of plant‐environment interactions.
Preclinical Signs of a Temporomandibular Disorder in Female Patients With Episodic Cervicogenic Headache Versus Asymptomatic Controls: A Cross‐Sectional Study
Authors: Mingels Sarah , Dankaerts Wim , Granitzer Marita 
Published: March 2019

BackgroundThe International Classification of Headache Disorders, 3rd Edition, accepted “headache attributed to temporomandibular disorders” as a valid headache. The neurophysiologic interplay between cervical structures and the temporomandibular joint, however, might also suggest that a temporomandibular disorder could develop in patients with cervicogenic headache.ObjectiveTo compare the presence of preclinical temporomandibular signs between female patients with episodic cervicogenic headache and a control group.DesignCase‐controlled cross‐sectional design.SettingInstitutional setting: Hasselt University.ParticipantsTwenty‐two women (mean age ± SD: 20.7 ± 2.5 years) with episodic cervicogenic headache, without temporomandibular signs and 22 matched (gender, age, level of education, occupation) asymptomatic controls (21 ± 2.3 years).Methods(Un)assisted temporomandibular range of motion, pressure pain thresholds, painful palpations were examined and the level of perceived stress was measured.Main Outcome MeasurementsTemporomandibular range of motion (mm), pressure pain thresholds (kPa/cm²), painful palpations (yes/no), and level of perceived stress (Perceived Stress Scale).ResultsMaximal mouth‐opening was significantly smaller in the headache group (P <.05; effect size [ES] −0.45). Palpation of the masseter resulted in significantly more positive pain responses in the headache group at the left (P = .009; ES ∞) and right (P = .002;ES 17.5) origin, left (P = .004; ES 14.54) and right (P = .03; ES 5.71) body and left (P < .001; ES 12) insertion. Significantly lower pressure pain thresholds on the left and right anterior (P = .03; ES −0.33 resp. P = .02; ES −0.35), central (P = .003; ES 1.02 resp. P = .02; ES 0.79) and right posterior (P = .03; ES 0.62) temporalis and right tibialis anterior (P = .03; ES −0.33) were measured in the headache group. The level of perceived stress was significantly higher (P = .02) in the headache group.ConclusionsPatients with episodic cervicogenic headache present with signs of a preclinical temporomandibular disorder and sensitization. The smaller range of motion, lower pressure pain thresholds, and higher levels of stress accentuate the multidimensionality of the problem.Level of EvidenceIV
Profiles and characteristics of bronchial responsiveness in general 7‐year‐old children
Authors: Park Ji Soo , Choi Yun Jung , Suh Dong In , Jung Sungsu , Kim Young‐Ho , Lee So‐Yeon , Yang Song‐I , Kwon Ji‐Won , Jang Gwang Cheon , Sun Yong Han , Woo Sung‐Il , Youn You‐Sook , Park Kang Seo , Cho Hwa Jin , Kook Myung‐Hee , Yi Hye Ryoung , Chung Hai Lee , Kim Ja Hyung , Kim Hyung Young , Jung Jin A , Woo Hyang‐Ok , Hong Soo‐Jong 
Published: March 2019

AbstractBackgroundAlthough bronchial responsiveness (BR) is usually categorized as normal or hyperresponsive to aid the diagnosis of asthma, it exists on a continuous spectrum, not in a dichotomous manner. We aimed to evaluate the distribution profile of BR in a general population of 7‐year‐olds.MethodsIn 2015, 7‐year‐old Korean children from a nationwide birth cohort study visited regional study hospitals for skin prick test, standard spirometry, and bronchial provocation to establish reference values for the general population. Their BR degrees were categorized into five ordered groups: hyperresponsive BRs were classified into group 1 (provocative concentration (PC) of methacholine causing a 20% fall in forced expiratory volume in 1 second [FEV1], PC20 of <4 mg/mL) and group 2 (PC20 of ≥4 mg/mL and <16 mg/mL), and nonresponsive BRs were categorized into group 3 (final FEV1 percentage fall after inhaling 16 mg/mL of methacholine [FEV1%fall] of >15% and ≤20%), group 4 (FEV1%fall of >10% and ≤15%), and group 5 (FEV1%fall of ≤10%).ResultsIn total, 559 subjects finished all tests reliably. Groups 1 and 2 comprised 10.0% and 15.7% of the total population, respectively. Groups 3, 4, and 5 comprised 14.7%, 18.4%, and 41.1%, respectively. As the group number increased, the proportion of those with recent wheezing and those with indoor allergen sensitization decreased (P for trend = 0.001 and P for trend < 0.001, respectively), and the baseline FEV1/FVC increased (P for trend < 0.001)ConclusionBR of the 7‐year‐olds in the general population, while showing a wide distribution across phenotypes, is associated with allergic symptoms, negatively correlated with baseline lung function and positively correlated with indoor allergen sensitization.
Nicotine oxidation by genetic variants of CYP2B6 and in human brain microsomes
Authors: Bloom Adam Joseph , Wang Pan‐Fen , Kharasch Evan D. 
Published: March 2019

AbstractCommon variation in the CYP2B6 gene, encoding the cytochrome P450 2B6 enzyme, is associated with substrate‐specific altered clearance of multiple drugs. CYP2B6 is a minor contributor to hepatic nicotine metabolism, but the enzyme has been proposed as relevant to nicotine‐related behaviors because of reported CYP2B6 mRNA expression in human brain tissue. Therefore, we hypothesized that CYP2B6 variants would be associated with altered nicotine oxidation, and that nicotine metabolism by CYP2B6 would be detected in human brain microsomes. We generated recombinant enzymes in insect cells corresponding to nine common CYP2B6 haplotypes and demonstrate genetically determined differences in nicotine oxidation to nicotine iminium ion and nornicotine for both (S) and (R)‐nicotine. Notably, the CYP2B6.6 and CYP2B6.9 variants demonstrated lower intrinsic clearance relative to the reference enzyme, CYP2B6.1. In the presence of human brain microsomes, along with nicotine‐N‐oxidation, we also detect nicotine oxidation to nicotine iminium ion. However, unlike N‐oxidation, this activity is NADPH independent, does not follow Michaelis‐Menten kinetics, and is not inhibited by NADP or carbon monoxide. Furthermore, metabolism of common CYP2B6 probe substrates, methadone and ketamine, is not detected in the presence of brain microsomes. We conclude that CYP2B6 metabolizes nicotine stereoselectively and common CYP2B6 variants differ in nicotine metabolism activity, but did not find evidence of CYP2B6 activity in human brain.
Effect of turmeric on glycemic status, lipid profile, hs‐CRP, and total antioxidant capacity in hyperlipidemic type 2 diabetes mellitus patients
Authors: Adab Zohreh , Eghtesadi Shahryar , Vafa Mohammad‐Reza , Heydari Iraj , Shojaii Asieh , Haqqani Hamid , Arablou Tahereh , Eghtesadi Maryam 
Published: March 2019

Diabetes mellitus is the most common metabolic disorder worldwide. This study examined the effect of turmeric supplementation on glycemic status, lipid profile, hs‐CRP and total antioxidant capacity in hyperlipidemic type 2 diabetic patients. In this double‐blind, randomized clinical trial, 80 hyperlipidemic type 2 diabetic patients were divided into turmeric (2,100 mg powdered rhizome of turmeric daily) and placebo groups for 8 weeks. Body weight, fasting plasma glucose, hemoglobin A1c (HbA1c), serum insulin, triglyceride (TG), total cholesterol, low density lypoprotein cholesterol (LDL‐c), high density lypoprotein cholesterol, apolipoprotein A1, apolipoprotein B, high sensitivity C‐reactive protein (hs‐CRP), and total antioxidant capacity were measured before and after intervention. Statistical analysis was carried out using paired and independent t and chi‐square tests. Seventy five patients completed the study. The turmeric group showed significant decreases in body weight, TG, and LDL‐c compared with baseline (p value < 0.05). Body mass index, TG, and total cholesterol decreased significantly in the turmeric group compared with the placebo group (p value < 0.05). No significant changes were observed in other parameters between the two groups after intervention (p value < 0.05). Turmeric improved some fractions of lipid profile and decreased body weight in hyperlipidemic patients with type 2 diabetes. It had no significant effect on glycemic status, hs‐CRP, and total antioxidant capacity in these patients.
First‐principles study of vibrational properties of TiSiO4 clusters
Authors: Majid Abdul , Batool Amber , Khan Salah Ud‐Din , Haider Sajjad 
Published: March 2019

AbstractFirst‐principles calculations were performed to investigate the vibrational properties of monomers and dimers of titania, silica, and titania‐silica hybrid clusters. Density functional theory‐based formulism was employed to optimize the geometry at the B3LYP level and calculate the infrared and Raman spectra of the clusters by using the GGA‐PBE exchange‐correlation functional. It was found that the vibrational spectra of Ti2O4, Si2O4, and TiSiO4 hybrid clusters provide fingerprint information about structures and structural transitions during the formation of cluster structures. In the case of Si2O4 the mode at 410 cm−1 exhibited the largest vibration of Si atoms, whereas in the case of Ti2O4 the mode at 442 cm−1 exhibited the largest vibration of Ti atoms. The hybrid cluster TiSiO4 was structured using two different methods to explore the effects of starting geometry on the structures and vibrational modes of the clusters. The structural properties of the clusters remained unchanged but vibrational modes were found to be different. It is found that Si shows notable vibrations, but the metal atom Ti merely shows any vibration in the case of TiSiO4 hybrid clusters. The low and intermediate frequency modes were stiffened, whereas the three highest frequency modes were softened when the starting geometry of the hybrid clusters was changed from Si2O4 to Ti2O4.