bluuebunny/crossref_metadata_2025_split huggingface dataset:
Within‐ and between‐session reproducibility of GABA measurements with MR spectroscopy
Authors: Brix Maiken K. , Ersland Lars , Hugdahl Kenneth , Dwyer Gerard E. , Grüner Renate , Noeske Ralph , Beyer Mona K. , Craven Alexander R. 
Published: February 2017

PurposeThe reproducibility of the MEGA‐PRESS (MEshcher‐GArwood Point RESolved Spectroscopy) MR spectroscopy sequence for the measurement of gamma‐ aminobutyric acid (GABA) is addressed, focusing on optimizing the number of repetitions at two voxel locations in the human brain and associated possibilities in analysis tools.Materials and MethodsTwo 20‐min MEGA‐PRESS acquisitions were run (echo time = 68 ms, repetition time = 1800 ms, repetitions = 328): one from a 21 mL volume in the anterior cingulate cortex (ACC) and one from a 22 mL volume in the left Broca's area in 21 healthy male volunteers (age 32 years ± 6[SD]). Subjects were scanned twice with identical protocols, 1 week apart. Data were acquired on a 3 Tesla GE Discovery 750 scanner using a 32‐channel head coil. Spectroscopy data were partitioned into shorter epochs, numerically equivalent to scans of progressively increasing duration, and compared both within and between sessions. Three different analysis schemes were applied: (1) Vendor prototype preprocessor, with quantification by LCModel. (2) Pure Gannet pipeline. (3) Preprocessing with Gannet, and quantification with LCModel. The coefficient of variation (CV) were calculated as a measure of reproducibility.ResultsIncreasing the number of repetitions showed improvements for within‐ and between‐session reproducibility up to around 218 repetitions. (CV ranging from 4 to 14%). Gannet combined with LCModel approach proved the best method. (CV = 4–5%). Measurements from the ACC area had higher CVs than the Broca area. (CV = 6–14% versus 4–7%).ConclusionMeasurement in the Broca area yields better reproducibility than the ACC. With appropriate acquisition times and preprocessing tools, measurements from the ACC area are also reliable.Level of Evidence: 1Technical Efficacy: Stage 1J. MAGN. RESON. IMAGING 2017;46:421–430
Medial femur T2 Z‐scores predict the probability of knee structural worsening over 4–8 years: Data from the osteoarthritis initiative
Authors: Joseph Gabby B. , McCulloch Charles E. , Nevitt Michael C. , Gersing Alexandra S. , Schwaiger Benedikt J. , Kretzschmar Martin , Heilmeier Ursula , Link Thomas M. 
Published: February 2017

ObjectiveThe purpose of this study was to determine the probability of structural worsening of knee cartilage and whole joint degeneration over 4–8 years based on cartilage T2 Z‐scores at baseline.DesignRight knees with Kellgren‐Lawrence (KL) grades of 0–2 in 587 participants from the Osteoarthritis Initiative were studied. 3T MR images were used to perform baseline cartilage T2 quantification and assess 4‐year changes in cartilage morphology (WORMS scoring) in 5 regions. Changes in joint space narrowing (JSN) and KL were assessed over 8 years. T2 Z‐scores were based on a reference database of knees without morphologic cartilage degeneration at baseline. Odds ratios for, and predicted probabilities of any worsening in WORMS cartilage, JSN and KL grade were obtained from logistic regression models.ResultsA one‐unit increase in the baseline medial femur T2 Z‐score was associated with cartilage worsening in the same region (OR = 1.59; P < 0.0001) and in any region (OR = 1.37; P < 0.0001), and with worsening JSN (OR = 1.82; P < 0.0001) and KL grades (OR = 1.69; P < 0.0001). Predicted probabilities of worsening in knees with a medial femur T2 Z‐score from 2–4 were 38% for medial femur cartilage WORMS, 70% for any cartilage region, 28% for increasing JSN and 31% for increasing KL grade.ConclusionKnees with elevated cartilage T2 (especially in the medial femur and those that are 2 to 4 SDs above the mean reference values) are significantly more likely to have structural worsening over 4 to 8 years. Knowing cartilage T2 Z‐scores may aid in targeting prevention efforts at early stages of osteoarthritis.Level of Evidence: 2Technical Efficacy: Stage 3J. Magn. Reson. Imaging 2017;46:1128–1136.
Variations and changes of annual precipitation in Central Asia over the last century
Authors: Hu Zengyun , Zhou Qiming , Chen Xi , Qian Cheng , Wang Shanshan , Li Jianfeng 
Published: February 2017

ABSTRACTThis study examines the temporal variations and spatial distributions of annual precipitation over Central Asia during the periods of 1901–2013, 1951–2013, and 1979–2013 using the latest version of Global Precipitation Climatology Centre (GPCC) full data reanalysis version 7 (GPCC V7) data set. The linear trend and multiperiods of the precipitation over the entire region and plain and mountainous area separately are analysed by linear least square method and ensemble empirical mode decomposition method. An overall increasing trend [0.66 mm (10 years)−1] is found for the entire region during 1901–2013, which is smaller than that of 1951–2013. The regional annual precipitation exhibits multi‐decadal variations, with a sharp decline during 1901–1944, followed by an increase until 1980s, and a fluctuation thereafter. During 1979–2013, the mountainous area shows a greater increasing trend than the entire region. Furthermore, the regional annual precipitation has exhibited high‐frequency variations with 3‐year and 6‐year quasiperiods and a low‐frequency variation with 28‐year quasiperiods. In terms of the spatial distribution, increasing trend in the annual precipitation is found in Xinjiang and decreasing trends appear over the five countries of Central Asia during 1951–2013. Empirical orthogonal function results show that the mountainous area is the large variability centre of the annual precipitation. The dominant mode of interannual variability in Central Asia annual precipitation is related to El Niño‐Southern Oscillation, which explains about 17% of the interannual variance during 1951–2013. The results of this study describe the long‐term variation in the annual precipitation over Central Asia as well as its relationship with some key climate indices in great detail, which will benefit the understanding and the prediction of the climate variations in this region.
Stent placement prior to initiation of chemotherapy in patients with obstructive, nonoperative left sided tumors is associated with fewer stomas
Authors: Suárez Javier , Marín Gabriel , Vera Ruth , Colibaseanu Dorin , Vila Juan J. , Ciga Miguel A. , Oronoz Begoña 
Published: February 2017

BACKGROUND AND OBJETIVESDue to the potential risks associated with stent placement, European Society Gastrointestinal Endoscopy does not recommend prophylactic insertion of stents in patients without symptoms. The aim was to compare complication rates, need of surgery, colostomy formation, and survival between stent placement prior to start of chemotherapy (SEMS group) and upfront ChT (ChT group) in patients with endoscopically non‐transverable metastatic left‐sided colorectal cancer.METHODSGender, age, CEA, tumor location, sites of metastatic disease, peritoneal involvement, liver involvement, and angiogenesis inhibitors administration, were recorded. Complication rates, need of surgery, stoma creation, and survival were compared between both groups by univariate and multivariate test. Complications of SEMS placement in both groups were compared.RESULTSWe studied 75 men and 40 women, with a mean age of 66.3 years. Overall complication and perforation rates were similar but patients in the ChT group had a significant higher need of surgery and subsequent stoma creation. Perforation after SEMS placement rates were higher in patients receiving ChT than in patients without ChT. Survival was related to peritoneal carcinomatosis and administration of biological agents.CONCLUSIONSSEMS placement prior to ChT administration dismissed the need of subsequent surgery and decreased the rates of permanent stoma formation.
Pulsed metall inert gas (MIG) welding and its effects on the microstructure and element distribution of an aluminum matrix reinforced with SiC composite material
Authors: Uluköy A. 
Published: February 2017

This study aims to demonstrate the effects of pulsed current on the welding pool and fusion zone microstructures of the aluminum 2014 alloy matrix composite material reinforced with 14 and 20 vol% SiC particles. A programmable synergic controlled MIG welding machine with pulsed power supply was used. One hundred Ampere and 120 Ampere pulsed current values were used to determine the effect of heat input on microstructures. A 1 mm diameter SG‐AlSi5 wire was used as filler material. The microstructures were studied using a scanning electron microscope (SEM) with energy dispersive X‐ray (EDX) spectroscopy, and the phase analyses were performed via X‐ray diffraction analyzer (XRD). The study showed that increasing the SiC rate has a greater effect on the formation of Al4C3 phase than increasing the heat input values. Al4C3 formation was not formed as a needle‐like structure.
Wholegrain oat diet changes the expression of genes associated with intestinal bile acid transport
Authors: Andersson Kristina E. , Chawade Aakash , Thuresson Narda , Rascon Ana , Öste Rickard , Sterner Olov , Olsson Olof , Hellstrand Per 
Published: February 2017

ScopeThe molecular mechanisms underlying the cholesterol‐lowering properties of oats are only partly known. To study possible pathways involved, we investigated gene expressions in the liver and small intestine of mice fed oats.Method and resultsCholesterol and bile acids were analyzed in plasma and feces from LDL‐receptor deficient (LDLr−/−) mice fed Western diet with wholegrain oats. A transcriptome analysis of mRNA from liver and jejunum was performed together with quantitative RT‐PCR. Oat‐fed mice had lower levels of plasma lipids and increased levels of bile acids and cholesterol in feces compared with controls. Two hundred thirty nine genes in jejunum and 25 genes in liver were differentially expressed (FDR corrected p < 0.05). The most affected biological process in jejunum was lipid biosynthesis and regulation. The apical sodium‐dependent bile acid transporter (ASBT, Slc10a) and the intracellular bile acid binding protein (Fabp6) were both upregulated, whereas small heterodimer partner‐1 (Shp‐1) and apolipoprotein CII (Apoc2) were downregulated.ConclusionsWhole oats attenuated responses typically induced by high‐fat diet. Increased expression of genes for intestinal bile acid uptake following oat consumption suggests retention in the gut lumen rather than decreased uptake capacity as cause for the increased bile acid excretion and the concomitant reduction of plasma cholesterol.
Spatiotemporal microstructural white matter changes in diffusion tensor imaging after transient focal ischemic stroke in rats
Authors: Jung Won‐Beom , Han Yong Hee , Chung Julius Juhyun , Chae Sun Young , Lee Sung Hoon , Im Geun Ho , Cha JiHoon , Lee Jung Hee 
Published: February 2017

Structural reorganization in white matter (WM) after stroke is a potential contributor to substitute or to newly establish the functional field on the injured brain in nature. Diffusion tensor imaging (DTI) is an imaging modality that can be used to evaluate damage and recovery within the brain. This method of imaging allows for in vivo assessment of the restricted movements of water molecules in WM and provides a detailed look at structural connectivity in the brain. For longitudinal DTI studies after a stroke, the conventional region of interest method and voxel‐based analysis are highly dependent on the user‐hypothesis and parameter settings for implementation. In contrast, tract‐based spatial statistics (TBSS) allows for reliable voxel‐wise analysis via the projection of diffusion‐derived parameters onto an alignment‐invariant WM skeleton. In this study, spatiotemporal WM changes were examined with DTI‐derived parameters (fractional anisotropy, FA; mean diffusivity, MD; axial diffusivity, DA; radial diffusivity, RD) using TBSS 2 h to 6 weeks after experimental focal ischemic stroke in rats (N = 6). FA values remained unchanged 2–4 h after the stroke, followed by a continuous decrease in the ipsilesional hemisphere from 24 h to 2 weeks post‐stroke and gradual recovery from the ipsilesional corpus callosum to the external capsule until 6 weeks post‐stroke. In particular, the fibers in these areas were extended toward the striatum of the ischemic boundary region at 6 weeks on tractography. The alterations of the other parameters in the ipsilesional hemisphere showed patterns of a decrease at the early stage, a subsequent pseudo‐normalization of MD and DA, a rapid reduction of RD, and a progressive increase in MD, DA and RD with a decreased extent in the injured area at later stages. The findings of this study may reflect the ongoing processes on tissue damage and spontaneous recovery after stroke.
Early mixed chimerism‐based preemptive immunotherapy in children undergoing allogeneic hematopoietic stem cell transplantation for acute leukemia
Authors: Horn Biljana , Wahlstrom Justin T. , Melton Alexis , Liou Angela , Ouachee‐Chardin Marie , Sunkersett Gauri , Willert Jennifer , Hwang Jimmy , Expose‐Spencer Jueleah , Cowan Mort C. , Facchino Janelle , Dvorak Christopher C. 
Published: February 2017

AbstractThis retrospective analysis comprises 10‐year experience with early posttransplant mixed chimerism‐based preemptive intervention. Out of 104 patients, 51 received preemptive immunotherapy. Their outcomes were similar to patients achieving full donor chimerism spontaneously. Among patients receiving intervention, 5‐year event‐free survival was identical in patients with and without pretransplant residual disease, respectively (68% [95% confidence interval (CI) 38–98%] vs. 69% [95% CI 54–85%] log–rank = 0.4). In patients who received preemptive immunotherapy, chimerism status and residual disease prior to transplant were no longer predictors of poor outcome; however, 41% of the patients with residual disease prior to transplant relapsed early and did not benefit from this strategy.
The clinical significance of equivocal findings on spinal MRI in children with medulloblastoma
Authors: Bennett Julie , Ashmawy Ramy , Ramaswamy Vijay , Stephens Derek , Bouffet Eric , Laperriere Normand , Taylor Michael , Shroff Manohar , Bartels Ute 
Published: February 2017

AbstractBackgroundMedulloblastoma (MB) is the most common malignant brain tumor of childhood, with cerebrospinal fluid spread the most common site of metastasis. Currently, children diagnosed with MB and evidence of spinal metastasis are treated with an increased dose of craniospinal radiation (CSI). This report reviewed equivocal abnormalities including nerve root clumping, linear vascular enhancement, nerve root enhancement and/or other vague findings on spinal magnetic resonance imaging (MRI) to elucidate their prognostic significance and aid in risk stratification.MethodsThis retrospective cohort study identified children (≥3 years) diagnosed with MB between 1988 and 2012. Children treated with upfront CSI were included, and staging spine MRI must have been done preoperatively or within 72 hr of primary tumor resection. Initial MRI of the spine was assessed by two independent reviewers blinded to outcome to evaluate for equivocal findings. Survival analysis was done to determine impact on prognosis.ResultsOne hundred of 157 patients were eligible for the analysis. Equivocal findings were identified in 48 (48%) patients, with MRI done preoperatively in 45 (94%) patients. Analysis by subgroup identified a higher proportion of equivocal findings in the sonic hedgehog (SHH) subgroup (P = 0.007). Five‐year overall survival (OS) in children with equivocal findings compared to those with normal MRI was not different, 80 vs. 84.8% respectively, while OS in M3 patients was worse at 54.7% (P = 0.02).ConclusionA higher proportion of equivocal findings was identified in the SHH subgroup. This institutional retrospective review demonstrates equivocal findings are common, not associated with decreased OS and should not prompt increased dose of CSI.
Prevention of chemotherapy‐induced vomiting in children receiving multiple‐day cisplatin chemotherapy: A hospital‐based, retrospective cohort study
Authors: Kishimoto Kenji , Kawasaki Keiichiro , Saito Atsuro , Kozaki Aiko , Ishida Toshiaki , Hasegawa Daiichiro , Kosaka Yoshiyuki 
Published: February 2017

AbstractBackgroundOptimal prevention of chemotherapy‐induced vomiting (CIV) has not been established for patients receiving cisplatin in divided doses. The aim of this study was to describe the incidence and risk factors of CIV in children who received multiple‐day cisplatin chemotherapy.ProcedureA total of 24 consecutive pediatric patients (age 0–19 years) who received multiple‐day cisplatin chemotherapy in our hospital were enrolled. Patients with relapsed disease or primary intracranial tumor and those who received concurrent radiation therapy were excluded. The number of chemotherapy cycles reviewed was 107, with a median of five per patient. All patients received granisetron. Dexamethasone and NK‐1 receptor antagonists (NK1RA) were used as additional antiemetics for prophylaxis of CIV.ResultsCIV was observed in 22 of 24 (92%) patients, and 61 of 107 (57%) cycles. Patients who developed CIV had a higher incidence of other chemotherapy‐related adverse events (87 vs. 41%, P < 0.001). The incidence of CIV was lower in patients administered with NK1RA than those without (32 vs. 68%, P < 0.001). Multivariate logistic regression identified age less than or equal to 2 years (odds ratio [OR] = 0.25, 95% confidence interval [CI] = 0.10–0.63) and administration of NK1RA (OR = 0.16, 95% CI = 0.06–0.43) as independent factors for CIV.ConclusionsThese results suggest that NK1RA is crucial to reduce CIV in children who receive multiple‐day cisplatin chemotherapy.
Avoidance of Maternal Cell Contamination and Overgrowth in Isolating Fetal Chorionic Villi Mesenchymal Stem Cells from Human Term Placenta
Authors: Sardesai Varda S. , Shafiee Abbas , Fisk Nicholas M. , Pelekanos Rebecca A. 
Published: February 2017

Abstract
Human placenta is rich in mesenchymal stem/stromal cells (MSC), with their origin widely presumed fetal. Cultured placental MSCs are confounded by a high frequency of maternal cell contamination. Our recent systematic review concluded that only a small minority of placental MSC publications report fetal/maternal origin, and failed to discern a specific methodology for isolation of fetal MSC from term villi. We determined isolation conditions to yield fetal and separately maternal MSC during ex vivo expansion from human term placenta. MSCs were isolated via a range of methods in combination; selection from various chorionic regions, different commercial media, mononuclear cell digest and/or explant culture. Fetal and maternal cell identities were quantitated in gender-discordant pregnancies by XY chromosome fluorescence in situ hybridization. We first demonstrated reproducible maternal cell contamination in MSC cultures from all chorionic anatomical locations tested. Cultures in standard media rapidly became composed entirely of maternal cells despite isolation from fetal villi. To isolate pure fetal cells, we validated a novel isolation procedure comprising focal dissection from the cotyledonary core, collagenase/dispase digestion and explant culture in endothelial growth media that selected, and provided a proliferative environment, for fetal MSC. Comparison of MSC populations within the same placenta confirmed fetal to be smaller, more osteogenic and proliferative than maternal MSC. We conclude that in standard media, fetal chorionic villi-derived MSC (CV-MSC) do not grow readily, whereas maternal MSC proliferate to result in maternal overgrowth during culture. Instead, fetal CV-MSCs require isolation under specific conditions, which has implications for clinical trials using placental MSC.
Differential Peer Effects, Student Achievement, and Student Absenteeism: Evidence From a Large-Scale Randomized Experiment
Authors: Eren Ozkan 
Published: February 2017

AbstractUsing data from a well-executed randomized experiment, I examine the effects of gender composition and peer achievement on high school students’ outcomes in disadvantaged neighborhoods. Results show that having a higher proportion of female peers in the classroom improves girls’ math test scores only in less-advanced courses. For male students, the estimated gender peer effects are positive but less precisely estimated. I also find no effect of average classroom achievement on female math test scores. Males, on the other hand, seem to benefit from a higher-achieving classroom. I propose mechanisms relating to lower gender stereotype influences and gender-specific attitudes toward competition as potential explanations for peer effects findings. Finally, having a higher proportion of female students in the classroom decreases student absenteeism among male students but has no impact on female attendance.
Introducing a novel mesh following technique for approximation-free robotic tool path trajectories
Authors: Mineo Carmelo , Pierce Stephen Gareth , Nicholson Pascual Ian , Cooper Ian 
Published: February 2017

Abstract
Modern tools for designing and manufacturing of large components with complex geometries allow more flexible production with reduced cycle times. This is achieved through a combination of traditional subtractive approaches and new additive manufacturing processes. The problem of generating optimum tool-paths to perform specific actions (e.g. part manufacturing or inspection) on curved surface samples, through numerical control machinery or robotic manipulators, will be increasingly encountered. Part variability often precludes using original design CAD data directly for toolpath generation (especially for composite materials), instead surface mapping software is often used to generate tessellated models. However, such models differ from precise analytical models and are often not suitable to be used in current commercially available path-planning software, since they require formats where the geometrical entities are mathematically represented thus introducing approximation errors which propagate into the generated toolpath. This work adopts a fundamentally different approach to such surface mapping and presents a novel Mesh Following Technique (MFT) for the generation of tool-paths directly from tessellated models. The technique does not introduce any approximation and allows smoother and more accurate surface following tool-paths to be generated. The background mathematics to the new MFT algorithm are introduced and the algorithm is validated by testing through an application example. Comparative metrology experiments were undertaken to assess the tracking performance of the MFT algorithms, compared to tool-paths generated through commercial software. It is shown that the MFT tool-paths produced 40% smaller errors and up to 66% lower dispersion around the mean values.
Highlights This work presents a technique for generation of tool-paths from tessellated models. The technique does not introduce approximations to surface following tool-paths. Comparative metrology experiments were carried out to assess the technique. The technique produces smaller errors and lower dispersion around the mean values. The developed method is aligned with the growing use of surface mapping techniques.