bluuebunny/crossref_metadata_2025 huggingface dataset:
Liver fibrosis imaging: A clinical review of ultrasound and magnetic resonance elastography
Authors: Zhang Yingzhen N. , Fowler Kathryn J. , Ozturk Arinc , Potu Chetan K. , Louie Ashley L. , Montes Vivian , Henderson Walter C. , Wang Kang , Andre Michael P. , Samir Anthony E. , Sirlin Claude B.
Published: March 2019

Liver fibrosis is a histological hallmark of most chronic liver diseases, which can progress to cirrhosis and liver failure, and predisposes to hepatocellular carcinoma. Accurate diagnosis of liver fibrosis is necessary for prognosis, risk stratification, and treatment decision‐making. Liver biopsy, the reference standard for assessing liver fibrosis, is invasive, costly, and impractical for surveillance and treatment response monitoring. Elastography offers a noninvasive, objective, and quantitative alternative to liver biopsy. This article discusses the need for noninvasive assessment of liver fibrosis and reviews the comparative advantages and limitations of ultrasound and magnetic resonance elastography techniques with respect to their basic concepts, acquisition, processing, and diagnostic performance. Variations in clinical contexts of use and common pitfalls associated with each technique are considered. In addition, current challenges and future directions to improve the diagnostic accuracy and clinical utility of elastography techniques are discussed.

Level of Evidence: 5

Technical Efficacy Stage: 2 J. Magn. Reson. Imaging 2020;51:25–42.
The impact of the presence of left atrial low voltage areas on outcomes from pulmonary vein isolation
Authors: Ahmed‐Jushuf Fiyyaz , Murgatroyd Francis , Dhillon Para , Scott Paul A.
Published: March 2019

Background

AF ablation (AFA) with pulmonary vein isolation (PVI) is highly successful for paroxysmal atrial fibrillation (PAF). However, success rates for persistent AF (PsAF) are significantly lower. In this study we evaluate the impact of left atrial (LA) low voltage areas (LVA) on response to AFA.

Methods

Consecutive patients undergoing first‐time radiofrequency AFA were included (n = 160, 53% PAF). PVI was performed followed by LA voltage mapping during sinus rhythm. Patients were categorized as having LVA based on the presence of LVA (0.2‐0.5 mV) in the LA assessed visually by the operator intra‐procedurally. Further adjunctive LA ablation was performed at the operators’ discretion. The end‐point was recurrence of any sustained atrial arrhythmia (atrial fibrillation/tachycardia/flutter) during 12 months follow‐up.

Results

All patients had PVI and 23 (14%) had adjunctive LA ablation. LVA were found in 49 (31%) patients and were an independent predictor of arrhythmia recurrence. Patients with LVA compared to those without had significantly lower 12‐month arrhythmia‐free survival in both PAF (38% vs 76%; P = 0.002) and PsAF (27% vs 61%; P = 0.015). PsAF patients without LVA (93% had PVI alone) had similar arrhythmia‐free survival to patients with PAF (61% vs 67%, respectively; P = 0.42). Recurrence in patients with LVA compared to those without was more likely to be an organized atrial arrhythmia rather than AF (16/30 recurrences vs 2/26, P < 0.001).

Conclusions

The presence of LVA predicts AFA success as well as the type of arrhythmia recurrence. The absence of LVA identifies PsAF patients that respond well to a PVI‐based ablation strategy.
Evaluation of spatio‐temporal rainfall variability and performance of a stochastic rainfall model in Bangladesh
Authors: Chowdhury AFM Kamal , Kar Kanak Kanti , Shahid Shamsuddin , Chowdhury Rezaul , Rashid Md. Mamunur
Published: March 2019

Rainfall in Bangladesh exhibits persistent wet and dry anomalies associated with occurrence of floods and droughts. Assessing inter‐annual variability of rainfall is vital to account these hydrological extremes in the design and operations of water systems. However, the inter‐annual variability obtained from short record rainfall data might be misleading as it does not contain whole climate variability which signifies the utmost importance of stochastic rainfall models. Since the inter‐annual variability and stochastic models have not been explored adequately for rainfall in Bangladesh, this study evaluated (a) the spatio‐temporal variability of rainfall focusing on inter‐annual variability, and (b) applicability of a stochastic daily rainfall model, referred as the Decadal and Hierarchical Markov Chain (DHMC) model. Daily rainfall data of 1973–2012 for 18 stations across Bangladesh were used to investigate the probability distributions and autocorrelations of rainfall, and the model performances. Results show a higher magnitude of inter‐annual variabilities of rainfall depth (standard deviation 80–250 mm) and wet spells (standard deviation 4–6 days) in wetter months (June to September) across rainfall stations in the east region of the country. In contrast, higher rates of inter‐annual variabilities (i.e., coefficients of variations) were observed in drier months across the west region. Spatially, the dry spells were observed consistent across the country. Monthly rainfall showed decreasing trend over the region from west to the middle part of the country, whereas monthly number of wet days showed increasing trend over the eastern part. The DHMC was found to preserve the observed variabilities of rainfall at daily to multiyear resolutions at all stations, except a tendency to underestimate the autocorrelation of monthly rainfall depth. Despite this limitation, DHMC can be considered as a suitable stochastic rainfall simulator for a tropical monsoon climate like Bangladesh.
Non‐uniform strain distribution in anterolateral capsule of knee: Implications for surgical repair
Authors: Guenther Daniel , Sexton Stephanie L. , Bell Kevin M. , Irarrázaval Sebastián , Fu Freddie H. , Musahl Volker , Debski Richard E.
Published: March 2019

The existence of a ligamentous structure within the anterolateral capsule, which can be injured in combination with the anterior cruciate ligament, has been debated. Therefore, the purpose of this study was to determine the magnitude and direction of the strain in the anterolateral capsule in response to external loads applied to the knee. The anterolateral capsule was hypothesized to not function like a traditional ligament. A 6‐degree‐of‐freedom robotic testing system was used to apply ten external loads to human cadaveric knees (n = 7) in the intact and anterior cruciate ligament (ACL) deficient states. The position of strain markers was recorded on the midsubstance of the anterolateral capsule during the resulting joint kinematics to determine the magnitude and direction of the maximum principal strain. The peak maximum principal strain ranged from 22% to 52% depending on the loading condition. When histograms of strain magnitude values were analyzed to determine strain uniformity, the mean kurtosis was 1.296 ± 0.955, lower than a typical ligament, and the mean variance was 0.015 ± 0.008, higher than a typical ligament. The mean angles of the strain direction vectors compared to the proposed ligament ranged between 38° and 130° (p < 0.05). The magnitude of the maximum principal strain in the anterolateral capsule is much larger than a typical ligament and does not demonstrate a uniform strain distribution. The direction of strain is also not aligned with the proposed ligament. Clinical Significance: Reconstruction methods using tendons will not produce normal joint function due to replacement of a multi‐axial structure with a uni‐axial structure. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res
Temporal changes in synovial fluid composition and elastoviscous lubrication in the equine carpal fracture model
Authors: Feeney Elizabeth , Peal Bridgette T. , Inglis Jacqueline E. , Su Jin , Nixon Alan J. , Bonassar Lawrence J. , Reesink Heidi L.
Published: March 2019

The objective of this study was to examine temporal variations in synovial fluid composition and lubrication following articular fracture. Post‐traumatic osteoarthritis (PTOA) was induced by creating an osteochondral fracture in the middle carpal joint of four horses while the contralateral limb served as a sham‐operated control. Horses were exercised on a high‐speed treadmill, and synovial fluid was collected pre‐operatively and at serial timepoints until 75 days post‐operatively. Lubricin and hyaluronic acid (HA) concentrations were measured using sandwich ELISAs, and the molecular weight distribution of HA was analyzed via gel electrophoresis. Synovial fluid viscosity and cartilage friction coefficients across all modes of lubrication were measured on days 0, 19, 33, and 61 using a commercial rheometer and a custom tribometer, respectively. HA concentrations were significantly decreased post‐operatively, and high molecular weight HA (>6.1MDa) did not recover to pre‐operative values by the study termination at day 75. Lubricin concentrations increased after surgery to a greater extent in the OA as compared to sham‐operated limbs. Viscosity was significantly reduced after surgery. While boundary and elastoviscous mode friction coefficients did not vary, the transition number, representing the shift between these modes, was lower. Although more pronounced in the OA limbs, similar derangements in HA, HA molecular weight distribution, viscosity, and transition number were observed in the sham‐operated limbs, which may be explained by synovial fluid washout during arthroscopy. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res
Sensory profile and quality of chemically leavened gluten‐free sorghum bread containing different starches and hydrocolloids
Authors: Ari Akin Pervin , Miller Rebecca , Jaffe Taylor , Koppel Kadri , Ehmke Laura
Published: March 2019

BACKGROUND

Starches and hydrocolloids are commonly used in gluten‐free sorghum bread formulations to mimic wheat gluten functionality. The effect of different starches and hydrocolloids on the sensory profile and quality of gluten‐free sorghum bread is unknown. In this research, a lexicon for chemically leavened gluten‐free sorghum bread was developed and used to evaluate the sensory profile of sorghum bread made with potato starch plus xanthan gum, rice starch plus xanthan gum and tapioca starch plus hydroxypropyl methyl cellulose (HPMC).

RESULTS

A lexicon containing 28 attributes and references for appearance, aroma, flavor and texture/mouthfeel was developed by a panel highly trained in descriptive sensory analysis. The results obtained using sensory analysis and objective testing techniques showed that chemically leavened gluten‐free sorghum bread containing rice starch plus xanthan gum or tapioca starch plus HPMC had a significantly better appearance while bread containing potato starch plus xanthan gum or rice starch plus xanthan gum had a significantly better texture/mouthfeel.

CONCLUSION

The combination of rice starch and xanthan gum resulted in chemically leavened gluten‐free sorghum bread with better crumb appearance and texture/mouthfeel properties than bread made with potato starch plus xanthan gum or tapioca starch plus HPMC. Xanthan gum significantly increased the dietary fiber content of chemically leavened gluten‐free sorghum bread. © 2019 Society of Chemical Industry
Inhibitory effects of scoparone from chestnut inner shell on platelet‐derived growth factor‐BB‐induced vascular smooth muscle cell migration and vascular neointima hyperplasia
Authors: Jung Seung Hyo , Lee Gyoung Beom , Ryu Yunkyoung , Cui Long , Lee Hwan Myung , Kim Junghwan , Kim Bokyung , Won Kyung Jong
Published: March 2019

BACKGROUND

Compounds of the inner shell of chestnut (Castanea crenata) have diverse biological activities, including anti‐cancer and anti‐oxidant activities. Here we explored the effects of an extract of chestnut inner shells and of its bioactive component scoparone on vascular smooth muscle cell migration and vessel damage.

RESULTS

The ethanol extract of chestnut inner shells, containing 11 major compounds, inhibited platelet‐derived growth factor (PDGF)‐BB‐induced migration of rat aortic smooth muscle cells (RASMCs). Among these compounds, scoparone (6,7‐dimethoxycoumarin) suppressed RASMC migration and wound healing in response to PDGF‐BB but did not affect RASMC proliferation. In RASMCs, scoparone inhibited the PDGF‐BB‐induced rat aortic sprout outgrowth and attenuated the PDGF‐BB‐mediated increase in phosphorylation of mitogen‐activated protein kinases (MAPKs), p38 MAPK and extracellular signal‐regulated kinase 1/2. The in vivo administration of scoparone resulted in the attenuation of neointima formation in balloon‐injured carotid arteries of rats.

CONCLUSION

These findings demonstrate that scoparone, found in chestnut inner shells, may inhibit cell migration through suppression of the phosphorylation of MAPKs in PDGF‐BB‐treated RASMCs, probably contributing to the reduction of neointimal hyperplasia induced after vascular injury. Therefore, scoparone and chestnut inner shell may be a potential agent or functional food, respectively, for the prevention of vascular disorders such as vascular restenosis or atherosclerosis. © 2019 Society of Chemical Industry
Variation of drought resistance of rice genotypes released in different years in China
Authors: Wang Baoxiang , Xu Bo , Liu Yan , Chen Xubing , Liu Jiawei , Zhi Wenfang , Xing Yungao , Yang Bo , Li Jian , Chi Ming , Liu Jinbo , Chen Tingmu , Xu Dayong , Zhu Guanglong
Published: March 2019

BACKGROUND

Drought is the most serious limiting factor of rice production worldwide and is becoming more intensive with climate change in recent years. Screening and breeding drought‐tolerant rice genotypes are essential to maintain yield gain and ensure food security under adverse environments. However, thus far, little attention has been given to the temporal changes of drought resistance concomitant with the year of release in rice genetic breeding.

RESULTS

Sixteen rice genotypes bred or widely cultivated from 1934 to 2007 were grown in paddy fields (control) and upland fields (drought stress) to explore the variation of drought resistance in rice genotypes with the year of release. Grain yield and daily grain yield significantly increased with the year of release. The genetic improvements in the grain yield partially resulted from the significant increase in panicle, spikelets per panicle and filling percentage. In addition, various growth‐related characteristics like biomass, harvest index, relative growth rate, grain density and growth duration increased with an increase of genetic refinement of the genotypes through the years, and they contributed to improvement of final rice yields. However, grain yield, yield components and these growth‐related traits sharply declined under drought stress. Furthermore, the drought resistance coefficients of KYield, KDaily grain yield, KPanicle number, KSpikelets per panicle, KBiomass, KPlant height, KRelative growth rate and KFilling percentage were prominently improved by genetic breeding.

CONCLUSIONS

Drought resistance of rice genotypes has been significantly enhanced by genetic processes during the last 73 years in China, but they are still sensitive to drought conditions. Currently, there is still room for further improvement in drought resistance which is an important target in future breeding programs. © 2019 Society of Chemical Industry
Long‐term evaluation of satisfaction and side effects after modified uvulopalatopharyngoplasty
Authors: Friberg Danielle , Sundman Joar , Browaldh Nanna
Published: March 2019

Objectives/Hypothesis

We have previously shown that modified uvulopalatopharyngoplasty (UPPP) is effective to treat obstructive sleep apnea (OSA) and that the effect is stable after 24 months. This continuous report includes questionnaires and phone interviews.

Study Design

Prospective intervention study.

Methods

Sixty‐five patients with apnea‐hypopnea index (AHI) score ≥ 15, body mass index <36 kg/m2, and Epworth Sleepiness Scale (ESS) score ≥ 8 underwent modified UPPP after failing nonsurgical treatment. The results from a patient questionnaire at 6 and 24 months after surgery were correlated with age, body mass index, and ESS and AHI scores. Patients reporting side effects and/or regretting the surgery after 24 months were selected for phone interviews 9 years after surgery.

Results

The response rate was 80% and 74% at the 6‐ and 24‐month follow‐ups, respectively. Of those who responded to the questionnaire, 96% and 83% were satisfied after 6 and 24 months, respectively; 98% and 92% recommended the surgery. Side effects (globus, mucus, and voice and swallowing disorders) occurred in 38% and 31%, respectively. Dissatisfaction correlated significantly with high postoperative AHI and ESS scores, but not with occurrence of side effects. Younger subjects had a higher rate of recommendation and lower rate of side effects than did older subjects. Phone interviews after 9 years were responded to by 14 of 16 selected patients, and the responders reported minor or no side effects.

Conclusions

The vast majority of the OSA patients were satisfied 24 months after surgery, even though a third of them were experiencing side effects. Younger patients had fewer side effects than did older patients. Patients with better OSA outcomes were also more satisfied. After 9 years the side effects were no longer problematic.

Level of Evidence

2b Laryngoscope, 130:263–268, 2020
Factors associated with opioid use after endoscopic sinus surgery
Authors: Raikundalia Milap D. , Cheng Tracy Z. , Truong Tracy , Kuchibhatla Maragatha , Ryu Jiyoung , Abi Hachem Ralph , Jang David W.
Published: March 2019

Objectives/Hypothesis

Responsible prescribing of postoperative pain medications is necessary in combatting the current opioid epidemic in the United States. The goal of this study was to determine which clinical factors affect opioid usage following functional endoscopic sinus surgery (FESS).

Study Design

Retrospective medical records study.

Methods

This is a single‐institution retrospective study of subjects undergoing FESS by the senior author between September 2016 and December 2017. Opioid usage was assessed for each patient at the first postoperative visit. Univariate and multivariable analyses were performed to investigate factors associated with pain medication usage. Patients using opioids prior to surgery were excluded.

Results

A total of 136 patients were stratified into three groups based on number of opioid tablets taken during the first week after surgery: 31 patients (23%) took no opioids, 61 patients (45%) took one to five tablets, and 44 patients (32%) took more than five tablets. Gender, extent of surgery, revision surgery, polyp status, and cystic fibrosis did not significantly vary between the three groups. Multinomial logistic regression analysis with backward stepwise variable selection method revealed that those who had septoplasty (odds ratio [OR]: 4.84, 95% confidence interval [CI]: 1.68‐13.98; P < .01) or were of younger age (OR 0.96, 95% CI: 0.93‐0.99; P = .01) had significantly higher odds of taking >5 tablets.

Conclusions

The majority of patients undergoing FESS did not take more than 5 opioid tablets after surgery. Concurrent septoplasty and younger age were associated with increased opioid usage. Knowledge of such factors can help surgeons to assess opioid prescribing patterns and to counsel their patients on postoperative pain.

Laryngoscope, 129:1751–1755, 2019
Value of lingual lymph node metastasis in patients with squamous cell carcinoma of the tongue
Authors: Fang Qigen , Li Peng , Qi Jinxing , Luo Ruihua , Chen Defeng , Zhang Xu
Published: March 2019

Objectives

To investigate the role of lingual lymph node (LLN) metastasis on locoregional control (LRC) in patients with locally advanced tongue squamous cell carcinoma (SCC).

Methods

A total of 231 patients were prospectively enrolled. Analyses focused on the association between the LLN metastasis and clinical pathologic variables as well as the significance of LLN metastasis in predicting prognosis.

Results

LLNs were noted in 58 patients, 33 of whom were positive for LLN metastasis. LLN metastasis was significantly related to adverse pathologic characteristics. In patients with LLN metastasis, the 5‐year LRC rate was 45%. In patients without LLN metastasis, the 5‐year LRC rate was 65% and the difference was significant (P = 0.013). Further, Cox model analysis confirmed the independence of LLN metastasis from prognosis prediction.

Conclusion

LLN metastasis in locally advanced tongue SCC is relatively uncommon; however, LLNs should be routinely dissected because they could significantly decrease locoregional control.

Level of Evidence

2b. Laryngoscope, 129:2527–2530, 2019
Living Donor Liver Transplantation for Acute Liver Failure: Donor Safety and Recipient Outcome
Authors: Pamecha Viniyendra , Vagadiya Ankur , Sinha Piyush Kumar , Sandhyav Rommel , Parthasarathy Kumaraswamy , Sasturkar Shridhar , Mohapatra Nihar , Choudhury Ashok , Maiwal Rakhi , Khanna Rajeev , Alam Seema , Pandey Chandra Kant , Sarin Shiv Kumar
Published: March 2019

In countries where deceased organ donation is sparse, emergency living donor liver transplantation (LDLT) is the only lifesaving option in select patients with acute liver failure (ALF). The aim of the current study is living liver donor safety and recipient outcomes following LDLT for ALF. A total of 410 patients underwent LDLT between March 2011 and February 2018, out of which 61 (14.9%) were for ALF. All satisfied the King’s College criteria (KCC). Median admission to transplant time was 48 hours (range, 24‐80.5 hours), and median living donor evaluation time was 18 hours (14‐20 hours). Median Model for End‐Stage Liver Disease score was 37 (32‐40) with more than two‐thirds having grade 3 or 4 encephalopathy and 70% being on mechanical ventilation. The most common etiology was viral (37%). Median jaundice‐to‐encephalopathy time was 15 (9‐29) days. Preoperative culture was positive in 47.5%. There was no difference in the complication rate among emergency and elective living liver donors (13.1% versus 21.2%; P = 0.19). There was no donor mortality. For patients who met the KCC but did not undergo LT, survival was 22.8% (29/127). The 5‐year post‐LT actuarial survival was 65.57% with a median follow‐up of 35 months. On multivariate analysis, postoperative worsening of cerebral edema (CE; hazard ratio [HR], 2.53; 95% confidence interval [CI], 1.01‐6.31), systemic inflammatory response syndrome (SIRS; HR, 16.7; 95% CI, 2.05‐136.7), preoperative culture positivity (HR, 6.54; 95% CI, 2.24‐19.07), and a longer anhepatic phase duration (HR, 1.01; 95% CI, 1.00‐1.02) predicted poor outcomes. In conclusion, emergency LDLT is lifesaving in selected patients with ALF. Outcomes of emergency living liver donation were comparable to that of elective donors. Postoperative worsening of CE, preoperative SIRS, and sepsis predicted outcome after LDLT for ALF.
Surface Microstructure Regulation of Porous Polymer Microspheres by Volume Contraction of Phase Separation Process in Traditional Suspension Polymerization System
Authors: Wang Jiqi , Yang Zuoting , Xu Jia , Ahmad Mudasir , Zhang Hepeng , Zhang Aibo , Zhang Qiuyu , Kou Xiaokang , Zhang Baoliang
Published: March 2019

In the present work, the suspension polymerization method is used for the preparation of porous polymer microspheres with different surface morphology, and the preparation mechanism is systematically expounded. The morphology results show that the smooth, convex, and wrinkled microspheres could be controlled by adjusting the ratio of monomer to porogens. The micelles forming the framework support the “Eggshell,” and its size and shape directly affect the morphology of “Eggshell.” The addition of monomers (GMA), whose polymer has low glass transition temperature (Tg), is important for the formation of wrinkled morphology. The amount of toluene and polydimethylsiloxane also affects the surface morphology of microspheres. In addition, the effect of polydimethylsiloxane is also more significant. The preparation process of the wrinkled P(GMA‐St‐EGDA) microspheres with abundant epoxy groups can be amplified. The morphology of the material prepared in the 100 L reactor is well maintained, and the yield in the size range of 80–160 µm is more than 80%. The surface wrinkled porous polymer microspheres have potential applications in the fields of enzyme carrier, separation and purification, and light scattering.
Traveling waves in a diffusive epidemic model with criss‐cross mechanism
Authors: Xu Zhiting , Guo Tingguang
Published: March 2019

In this paper, we propose a reaction‐diffusion system to describe the spread of infectious diseases within two population groups by self and criss‐cross infection mechanism. Firstly, based on the eigenvalues, we give two methods for the calculation of the critical wave speed c∗. Secondly, by constructing a pair of upper‐lower solutions and using the Schauder fixed‐point theorem, we prove that the system admits positive traveling wave solutions, which connect the initial disease‐free equilibrium
at t = −∞, but the traveling waves need not connect the final disease‐free equilibrium
at t = +∞. Hence, we study the asymptotic behaviors of the traveling wave solutions to show that the traveling wave solutions converge to
at t = +∞. Finally, by the two‐sided Laplace transform, we establish the nonexistence of traveling waves for the model. The approach in this paper provides an effective method to deal with the existence of traveling wave solutions for the nonmonotone reaction‐diffusion systems consisting of four equations.
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

Purpose

Atrial 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.

Methods

In 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.

Results

The 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).

Conclusion

The 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

Purpose

To 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.

Methods

Since 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.

Results

The 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).

Conclusion

MEGA‐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

Purpose

To 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.

Methods

MANTIS 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.

Results

MANTIS 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.

Conclusion

The 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

We 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.
Your institution can't afford to ignore the needs of adult learners
Authors: Sutton Halley
Published: March 2019

ATLANTA — With more than a quarter of current American undergraduates classified as adult students (27 percent of undergraduates are 25 years old or older), it is more important than ever to consider how the needs of adult learners are — and aren't — being met by our current higher education landscape. That was the message from a session on the urgency of the adult learner at the annual conference for the Association of American Colleges and Universities.
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

Objective

Rates 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.

Methods

Obesity 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.

Results

Data 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.

Conclusions

Being 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

Introduction

Calcium 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.

Objective

The main objective of this work was to identify the potential calcium antagonists from MC and study their molecular mechanisms.

Methods

Ultra‐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.

Results

Three 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).

Conclusion

This 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.
Tailor‐made controlled rheology polypropylenes from metallocene and Ziegler–Natta resins
Authors: Nie Shouliang , Tzoganakis Costas
Published: March 2019

Production of controlled rheology polypropylenes (CRPPs) is practiced industrially by modifying existing commodity Ziegler–Natta resins through peroxide‐induced β‐scission reactions, resulting in materials with controlled rheological properties and accompanying narrower molecular weight distributions (MWDs). In this work, this methodology was studied using both metallocene‐based polypropylenes (mPPs) and Ziegler–Natta‐based polypropylenes (ZN‐PPs). Numerical simulations based on a previously proposed kinetic model indicated that the nature of the starting resin has a significant effect on the control of MWD polydispersity index (PDI) and weight‐average molecular weight () of the resulting CRPP. Based on these observations, experiments were carried out to demonstrate the feasibility of producing CRPP with targeted molecular and rheological characteristics. Commercial mPP and ZN‐PP resins were selected to produce CRPP with similar or melt flow rates (MFRs) but varying PDIs. The rheological properties and MWDs of these materials were evaluated through oscillatory shear and gel permeation chromatography (GPC) measurements and their extrusion behavior was briefly studied and assessed with respect to these properties. POLYM. ENG. SCI., 59:1114–1121 2019. © 2019 Society of Plastics Engineers
Industrial Blue Diode Laser Breaks 1 kW Barrier
Authors: Britten Simon , Krause Volker
Published: March 2019

Up 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.
Snapshot Multispectral Imaging
Authors: Pust Oliver , Hubold Martin
Published: March 2019

A multispectral imaging concept based on a multi‐aperture system approach using a customized microlens array combined with a slanted continuously variable bandpass filter and a silicon‐based image sensor helps to overcome the restrictions of scanning techniques or wafer‐level coated detectors.
A mass participatory experiment provides a rich temporal profile of temperature response in spring onions
Authors: Brestovitsky Anna , Ezer Daphne
Published: March 2019

Plants 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

Background

The 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.

Objective

To compare the presence of preclinical temporomandibular signs between female patients with episodic cervicogenic headache and a control group.

Design

Case‐controlled cross‐sectional design.

Setting

Institutional setting: Hasselt University.

Participants

Twenty‐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 Measurements

Temporomandibular range of motion (mm), pressure pain thresholds (kPa/cm²), painful palpations (yes/no), and level of perceived stress (Perceived Stress Scale).

Results

Maximal 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.

Conclusions

Patients 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 Evidence

IV
Internet Architecture and Human Rights: Beyond the Human Rights Gap
Authors: Zalnieriute Monika , Milan Stefania
Published: March 2019

Internet architecture and infrastructure are generally not at the top of the concerns of end users, and the overlying logical arrangements of root services, domain names, and protocols remain largely invisible to its users. Recent developments, however—including massive user data leakages, hacks targeting social networking service providers, and behavioral micro‐targeting—have turned a spotlight on Internet governance defined broadly, and its relationship with civil liberties and human rights. The articles in this special issue examine the policymaking role of influential private intermediaries and private actors such as ICANN in enacting global governance via Internet architecture, exploring the implications of such a mode of governance for human rights. They consider: to what extent are human rights standards mediated and set via technical infrastructure, such as the DNS and platform policies, rather than by governmental structures? What are the implications of governance via Internet architecture for individual human rights? And what frameworks—be they legal, technological or policy‐related—are needed to address the contemporary privatization of human rights online, in order to ensure the effective protection of human rights in the digital age?
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

Background

Although 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.

Methods

In 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%).

Results

In 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)

Conclusion

BR 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.