bluuebunny/crossref_metadata_2025_split huggingface dataset:
MRI proton density fat fraction is robust across the biologically plausible range of triglyceride spectra in adults with nonalcoholic steatohepatitis
Authors: Hong Cheng William , Mamidipalli Adrija , Hooker Jonathan C. , Hamilton Gavin , Wolfson Tanya , Chen Dennis H. , Fazeli Dehkordy Soudabeh , Middleton Michael S. , Reeder Scott B. , Loomba Rohit , Sirlin Claude B. 
Published: August 2017

BackgroundProton density fat fraction (PDFF) estimation requires spectral modeling of the hepatic triglyceride (TG) signal. Deviations in the TG spectrum may occur, leading to bias in PDFF quantification.PurposeTo investigate the effects of varying six‐peak TG spectral models on PDFF estimation bias.Study TypeRetrospective secondary analysis of prospectively acquired clinical research data.PopulationForty‐four adults with biopsy‐confirmed nonalcoholic steatohepatitis.Field Strength/SequenceConfounder‐corrected chemical‐shift‐encoded 3T MRI (using a 2D multiecho gradient‐recalled echo technique with magnitude reconstruction) and MR spectroscopy.AssessmentIn each patient, 61 pairs of colocalized MRI‐PDFF and MRS‐PDFF values were estimated: one pair used the standard six‐peak spectral model, the other 60 were six‐peak variants calculated by adjusting spectral model parameters over their biologically plausible ranges. MRI‐PDFF values calculated using each variant model and the standard model were compared, and the agreement between MRI‐PDFF and MRS‐PDFF was assessed.Statistical TestsMRS‐PDFF and MRI‐PDFF were summarized descriptively. Bland–Altman (BA) analyses were performed between PDFF values calculated using each variant model and the standard model. Linear regressions were performed between BA biases and mean PDFF values for each variant model, and between MRI‐PDFF and MRS‐PDFF.ResultsUsing the standard model, mean MRS‐PDFF of the study population was 17.9 ± 8.0% (range: 4.1–34.3%). The difference between the highest and lowest mean variant MRI‐PDFF values was 1.5%. Relative to the standard model, the model with the greatest absolute BA bias overestimated PDFF by 1.2%. Bias increased with increasing PDFF (P < 0.0001 for 59 of the 60 variant models). MRI‐PDFF and MRS‐PDFF agreed closely for all variant models (R2 = 0.980, P < 0.0001).Data ConclusionOver a wide range of hepatic fat content, PDFF estimation is robust across the biologically plausible range of TG spectra. Although absolute estimation bias increased with higher PDFF, its magnitude was small and unlikely to be clinically meaningful.Level of Evidence: 3Technical Efficacy: Stage 2J. Magn. Reson. Imaging 2018;47:995–1002.
Investigation into diversity order at micro and/or macro level in gamma shadowed Nakagami‐m fading channels
Authors: Sekulović Nikola , Panajotović Aleksandra , Drača Dragan , Stefanović Mihajlo , Bandjur Miloš 
Published: August 2017

AbstractRadio wave propagation through wireless channels is characterized by 4 main physical phenomena: reflection, diffraction, scattering, and absorption. Considerable efforts have been devoted to develop precise mathematical description of signal fluctuations which is very helpful in designing and evaluating the performance of wireless communication systems. A space diversity reception technique presents effective method for increasing channel capacity and upgrading transmission reliability at relatively low cost. In this paper, wireless communication system with maximal‐ratio combining (MRC) microdiversity and selection combining (SC) macrodiversity reception operating over correlated gamma shadowed Nakagami‐m fading channels is studied. Average bit error probability (ABEP), outage probability and average channel capacity, being significant and generally adopted performance measures, are employed to investigate how system performance is affected by the number of base stations and the number of antennas per base station.
Representation of mid‐latitude North American coastal storm activity by six global reanalyses
Authors: Pingree‐Shippee Katherine A. , Zwiers Francis W. , Atkinson David E. 
Published: August 2017

ABSTRACTExtratropical cyclones often produce extreme and hazardous weather conditions, such as high winds, heavy precipitation, blizzard conditions, and flooding, all of which have detrimental environmental/physical and socio‐economic impacts. Furthermore, storm interaction with the ocean produces additional hazards, with major local impacts, including inundation and coastal erosion. The North American west coast is influenced by the North Pacific storm track and by ‘atmospheric river’ events while the east coast is particularly influenced by winter storms that track along two favoured routes: the St. Lawrence Valley and the Eastern Seaboard. Reanalysis provides an invaluable tool for studying the characteristics of storm events that are identified as causing the most severe impacts. However, reanalysis products differ substantially in spatial resolution, model physics, assimilation approach, and the data that are assimilated. This study evaluates the representation of storm activity along the mid‐latitude North American coastlines by six global reanalyses: NCEP‐1, NCEP‐2, ERA‐Interim, Modern‐Era Retrospective analysis for Research and Applications (MERRA), Climate Forecast System Reanalysis (CFSR), and Twentieth Century Reanalysis Version 2 (20CR). Storm activity representation is evaluated at annual and seasonal timescales (JFM, AMJ, JAS, OND, and ‘extended winter’ ONDFM) during the 1979–2010 time period through comparison with selected meteorological stations using single‐point surface pressure‐based proxies of extratropical storm activity. Stations are selected on the basis of record length, reporting frequency, coastal proximity, and relatively uniform spatial distribution. Comparisons are made using data extracted from the reanalysis grid box centre that is closest to each selected station. All reanalyses are found to successfully represent most aspects of mid‐latitude North American coastal strong storm activity, annually and seasonally, along both coasts. Nevertheless, ERA‐Interim, MERRA, and CFSR provide the better representations of mid‐latitude North American coastal strong storm activity, with ERA‐Interim performing best overall.
Impact of the boreal summer quasi‐biweekly oscillation on Eastern North Pacific tropical cyclone activity
Authors: Zhao Haikun , Raga Graciela B. , Klotzbach Philip J. 
Published: August 2017

ABSTRACTSeveral studies have focused on the impact of the Madden–Julian Oscillation (MJO, with a period between 30 and 60 days) on boreal summer tropical cyclone (TC) activity over the Eastern North Pacific (ENP) basin. The quasi‐biweekly oscillation (QBWO), with a period of about 20 days, is another dominant mode of intra‐seasonal variability during the boreal summer over the ENP basin. There have been fewer studies focused on the influence of the QBWO on tropical cyclogenesis over the ENP basin. The exploratory analyses performed in this study suggest that the QBWO has a strong impact on boreal summer ENP TC activity, with enhanced TC activity during the convectively active phase.The significant increase (decrease) of tropical cyclogenesis events during the convectively active (inactive) QBWO phase is found to be closely associated with the strengthening (weakening) of the low‐level cyclonic circulation and increasing (decreasing) mid‐level relative humidity (vertical wind shear) over the ENP. Mid‐level relative humidity and low‐level vorticity are found to be the two most important players in modulating TC genesis location and frequency, based upon the analyses of the anomalous genesis potential index pattern and its magnitude associated with the QBWO. Associated with changes in TC location and large‐scale steering flows, distinct difference in TC tracks during different QBWO phases can be readily found and thus cause substantial differences in basin‐wide TC intensity. This study enhances our understanding of the modulation of intra‐seasonal oscillations on boreal summer ENP TC activity and has the potential to aid in the sub‐seasonal prediction of ENP TC activity.
Relationship of cytokine levels and clinical effect on platelet‐rich plasma‐treated lateral epicondylitis
Authors: Lim Wonbong , Park Sang H. , Kim Bora , Kang Sin W. , Lee Jung W. , Moon Young L. 
Published: August 2017

ABSTRACTLateral epicondylitis (LE) is difficult to manage and can result in significant patient morbidity. Currently, the clinical use of platelet‐rich plasma (PRP) for painful tendons has received attention, but its efficacy remains controversial. This study aimed to investigate the clinical effects of PRP and its biological components. A total of 156 patients with LE were randomly divided into group 1, treated with a single injection of 2‐ml autologous PRP, and group 2, treated with a control received only physical therapy without injection. Both groups used a tennis elbow strap and performed stretching and strengthening exercises during 24 weeks’ follow‐up. Pain and functional improvements were assessed using the visual analog scale (VAS), Modified Mayo Clinic Performance Index for the elbow, and magnetic resonance imaging (MRI). White blood cell count, platelet count, and levels of platelet‐derived growth factor‐AB (PDGF‐AB), PDGF‐BB, transforming growth factor‐β (TGF‐β), vascular endothelial growth factor, epithelial growth factor, and interleukin‐1 β in PRP were measured and investigated for statistical correlation with the clinical score. At 24 weeks, all pain and functional variables, including VAS score, Mayo Clinic performance scores, and MRI grade, improved significantly in group 1 (p < 0.05). PDGF‐AB, PDGF‐BB, and TGF‐β levels were more significantly increased in PRP than in whole blood. TGF‐β level significantly correlated with Mayo Clinic performance score and MRI grade improvement. Thus, TGF‐β level in PRP is considered to play a pivotal role in tendon healing. These results may contribute to identifying the best protocol for PRP application in tendinopathies. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:913–920, 2018.
SERSanalysis of selectively captured exosomes using an integrin‐specific peptide ligand
Authors: Lee Changwon , Carney Randy , Lam Kit , Chan James W. 
Published: August 2017

AbstractWe demonstrate selective capturing of exosomes for surface‐enhanced Raman spectroscopy (SERS) analysis using a thiolated peptide ligand that is bound to the surface of silver nanoparticles via thiol‐metallic bond formation. The ligand preferentially binds to α3ß1 integrin over‐expressed in exosomes secreted from SKOV‐3 cancer cells. Several Raman peaks at 894 cm−1, 1,080 cm−1, 1,252 cm−1, 1,340 cm−1, and 1,380 cm−1specific to SKOV‐3 exosomes are detected above the background signals generated from the nanoparticle and the ligand. In comparison, α3ß1 integrin negative exosomes secreted from Jurkat cells showed no detectable exosome specific SERS signal, confirming the high specificity of this ligand‐based SERS detection approach. This study shows the potential of developing a target‐specific SERS detection approach for characterizing exosomes from a heterogeneous mixture in body fluid for early‐stage disease diagnostics.
Determination of betaine, l‐carnitine, and choline in human urine using a self‐packed column and column‐switching ion chromatography with nonsuppressed conductivity detection
Authors: Wei Dan , Liu Junwei , Guo Ming , Zhu Yan 
Published: August 2017

AbstractA simple method for the determination of betaine, l‐carnitine, and choline in human urine was developed based on column‐switching ion chromatography coupled with nonsuppressed conductivity detection by using a self‐packed column. A pretreatment column (50 mm × 4.6 mm, id) packed with poly(glycidyl methacrylate‐divinylbenzene) microspheres was used for the extraction and cleanup of analytes. Chromatographic separation was achieved within 10 min on a cationic exchange column (150 mm × 4.6 mm, id) using maleic anhydride modified poly(glycidyl methacrylate‐divinylbenzene) as the particles for packing. The detection was performed by ion chromatography with nonsuppressed conductivity detection. Parameters including column‐switching time, eluent type, flow rates of eluent, and interfering effects were optimized. Linearity (r2 ≥ 0.99) was obtained for the concentration range of 0.50–100, 0.75–100, and 0.25–100 μg/mL for betaine, l‐carnitine, and choline, respectively. Detection limits were 0.12, 0.20, and 0.05 μg/mL for betaine, l‐carnitine, and choline, respectively. The intra‐ and interday accuracy and precision for all quality controls were within ±10.11%. Satisfactory recovery was observed between 92.5 and 105.0%. The validated method was successfully applied for the determination of betaine, l‐carnitine, and choline in urine samples from healthy people.
Polypyrrole‐magnetite dispersive micro‐solid‐phase extraction combined with ultraviolet‐visible spectrophotometry for the determination of rhodamine 6G and crystal violet in textile wastewater
Authors: Kamaruddin Amirah Farhan , Sanagi Mohd Marsin , Wan Ibrahim Wan Aini , Md. Shukri Dyia S. , Abdul Keyon Aemi S. 
Published: August 2017

AbstractPolypyrrole‐magnetite dispersive micro‐solid‐phase extraction method combined with ultraviolet‐visible spectrophotometry was developed for the determination of selected cationic dyes in textile wastewater. Polypyrrole‐magnetite was used as adsorbent due to its thermal stability, magnetic properties, and ability to adsorb Rhodamine 6G and crystal violet. Dispersive micro‐solid‐phase extraction parameters were optimized, including sample pH, adsorbent amount, extraction time, and desorption solvent. The optimum polypyrrole‐magnetite dispersive micro‐solid phase‐extraction conditions were sample pH 8, 60 mg polypyrrole‐magnetite adsorbent, 5 min of extraction time, and acetonitrile as the desorption solvent. Under the optimized conditions, the polypyrrole‐magnetite dispersive micro‐solid‐phase extraction with ultraviolet‐visible method showed good linearity in the range of 0.05–7 mg/L (R2 > 0.9980). The method also showed a good limit of detection for the dyes (0.05 mg/L) and good analyte recoveries (97.4–111.3%) with relative standard deviations < 10%. The method was successfully applied to the analysis of dyes in textile wastewater samples where the concentration found was 1.03 mg (RSD ±7.9%) and 1.13 mg/L (RSD ± 4.6%) for Rhodamine 6G and crystal violet, respectively. It can be concluded that this method can be adopted for the rapid extraction and determination of dyes at trace concentration levels.
Isolated Single Umbilical Artery and Fetal Echocardiography: A 25‐Year Experience at a Tertiary Care City Hospital
Authors: Gurram Padmalatha , Figueroa Reinaldo , Sipusic Elizabeth , Kuhnly Nicole , Clark Shealagh , Janicki Mary Beth 
Published: August 2017

ObjectivesTo review our 25‐year experience with a single umbilical artery and fetal echocardiography to estimate the need for this test in cases of an isolated single umbilical artery.MethodsWe conducted a retrospective review of 436 patients with a diagnosis of a single umbilical artery at our institution between 1990 and 2015. Two hundred eighty‐eight women had both an anatomic survey and a fetal echocardiogram. Pregnancies with concurrent extracardiac anomalies or aneuploidy were excluded. The study population was divided into 3 groups based on cardiac views on the anatomic survey: normal, incomplete, and suspicious. Echocardiographic results were compared among the 3 groups. The primary outcome measure was the incidence of cardiac anomalies in the normal group at fetal echocardiography. The data were analyzed by the χ2 test or Fisher exact test.ResultsThe mean maternal age ± SD of the group was 29.2 ± 6.2 years; 44.1% were primiparas. The mean gestational age at diagnosis was 22.6 ± 5.2 weeks, and the mean gestational age at fetal echocardiography was 25.1 ± 3.6 weeks. In the normal group, 99.1% (230 of 232) of women had a normal fetal echocardiogram; the 2 abnormal cases were ventricular septal defects. Normal echocardiograms were obtained in 81.8% (36 of 44) and 25.0% (3 of 12) of the “incomplete” and “suspicious” groups, respectively.ConclusionsFetuses with a single umbilical artery, in the absence of structural abnormalities, and with normal cardiac views at the time of the anatomic survey do not warrant an echocardiogram.
Perinatal Outcomes Associated With Isolated Velamentous Cord Insertion in Singleton and Twin Pregnancies
Authors: Sinkin Joshua A. , Craig Wendy Y. , Jones Michael , Pinette Michael G. , Wax Joseph R. 
Published: August 2017

ObjectivesTo evaluate perinatal outcomes in singleton and twin pregnancies with pathologically confirmed velamentous cord insertion without vasa previa.MethodsThis retrospective case‐control study included all nonanomalous singleton and twin pregnancies with pathologically confirmed velamentous cord insertion delivered in a single institution between January 1, 2005, and July 1, 2015, and having an ultrasound examination by maternal‐fetal medicine. For each case, the next 2 consecutive deliveries matched for gestational age at delivery ± 1 week and, in twins, amnionicity and chorionicity served as controls. Primary outcomes included surgical delivery for a nonreassuring intrapartum fetal heart rate tracing, umbilical arterial cord pH of less than 7.2, 5‐minute Apgar score of less than 7, birth weight below the 10th percentile, neonatal intensive care unit admission, fetal or neonatal death, and cord avulsion necessitating manual placental extraction.ResultsOutcomes were available for 53 singletons with 103 matched controls and 33 twin pregnancies with 65 matched controls. In singletons, velamentous cord insertion was associated with cord pH of less than 7.2 (odds ratio [OR] 3.5; 95% confidence interval [CI], 1.1–11.2; P = .039), 5‐minute Apgar score of less than 7 (OR, 5.3; 95% CI, 0.99–28.1; P = .045), and cord avulsion requiring manual placental extraction (7.5% versus 0%; P = .012). Associations were suggested with increased surgical delivery for a nonreassuring intrapartum fetal heart rate tracing (OR, 2.4; 95% CI, 0.9–6.9; P = .14), birth weight below the 10th percentile (OR, 2.1; 95% CI, 0.8–5.9; P = .21), and fetal or neonatal death (3.8% versus 0%; P = .11). Velamentous cord insertions were also associated with placental abruption in singletons (7.5% versus 0%; P = .013). Among twins, velamentous cord insertion was associated with fetal or neonatal death (9.1% versus 0%; P = .036).ConclusionsIsolated confirmed velamentous cord insertion is associated with adverse perinatal outcomes in singleton and twin gestations.
Utility and Safety of Repeated Ultrasound‐Guided Core Needle Biopsy of Focal Liver Masses
Authors: Kim Jin Sil , Won Hyung Jin , Lee So Jung , Kim So Yeon , Shin Yong Moon , Kim Pyo Nyun 
Published: August 2017

ObjectivesTo evaluate the accuracy and safety of repeated ultrasound‐guided core needle biopsy (CNB) for hepatic focal lesions and to assess the predictive factors for success of repeated CNB.MethodsFor 5 years, 3085 CNBs were performed for focal hepatic lesions using an automated biopsy gun with an 18‐gauge needle. Seventy‐eight patients underwent repeated CNB because of pathologically inconclusive or unexpected results. Twelve patients were excluded because of unavailable additional tissue or follow‐up imaging by radiofrequency ablation (n = 5), repeated CNB greater than than 3 months after the first CNB (n = 5), and insufficient follow‐up time (n = 2). Sixty‐six patients were finally enrolled after the exclusion criteria were applied. We retrospectively evaluated tumor necrosis, tumor size, number of passes, lesion site, depth, tumor conspicuity, and complications. Continuous data and the total scores of the grading system were analyzed by the Student t test, and categorical data and each category were analyzed by the Fisher exact test.ResultsThe repeated CNB rate was 2.5% (78 of 3085). The diagnostic accuracy of the repeated biopsies was 83.3% (55 of 66). Comparing the diagnostic group with the nondiagnostic group, no variable (ie, size, depth, necrosis, lesion site [segment], and number of passes) had a statistically significant difference. Tumor conspicuity was a significant factor for predicting successful repeated biopsy (P < .001). The cumulative complication rate was 10.6% (7 of 66), with only minor complications.ConclusionsRepeated CNB is an accurate and safe procedure for obtaining a histologic diagnosis of hepatic focal lesions if the initial biopsy fails. High tumor conspicuity showed a significant correlation with successful repeated CNB.
Evaluation of Neonatal Brain Parenchyma Using 2‐Dimensional Shear Wave Elastography
Authors: Albayrak Eda , Kasap Tuba 
Published: August 2017

ObjectivesThe aim of this study was to evaluate the stiffness of the neonatal brain using 2‐dimensional shear wave elastography in term and preterm neonates and to investigate possible stiffness differences between groups.MethodsA total of 83 neonates, including 44 term and 39 preterm, were included in the study. Shear wave elastographic measurements of the thalamus and occipital periventricular white matter were conducted via the anterior fontanel. The Pearson correlation coefficient was used to determine the association between the birth week and stiffness values of the thalamus and periventricular white matter. A receiver operating characteristic analysis was applied to determine the power of the stiffness of the thalamus and periventricular white matter in predicting a significant preterm classification. P < .05 was considered significant.ResultsThe brain parenchymal stiffness values measured from both the thalamus and periventricular white matter were found to be significantly lower in the preterm group compared with the term group. The periventricular white matter stiffness values were found to be lower than thalamus stiffness values in both groups. According to the receiver operating characteristic curve, the optimal cutoff values for determining prematurity were defined to be less than 8.28 kPa for the mean thalamus stiffness and less than 6.59 kPa for the periventricular white matter.ConclusionsThis study shows that differences between brain stiffness values in preterm and term neonates can be shown by using 2‐dimensional shear wave elastography, and the results may be reference points for evaluating neonatal brain stiffness in research on patients with various illnesses.