bluuebunny/crossref_metadata_2025_split huggingface dataset:
Performance evaluation of the mindray anti‐HCV assay for the detection of hepatitis C virus infection
Authors: Yue Zhi‐hong , Xia Chang‐sheng , Wang Hui 
Published: July 2018

BackgroundAnti‐hepatitis C virus (anti‐HCV) antibody assays are recommended for HCV infection screening. The Mindray anti‐HCV assay, based on a third‐generation immunoassay, was recently launched in China. We aimed to evaluate its diagnostic performance compared with that of two other widely used assays.MethodsSix HCV infection seroconversion panels were used to evaluate the sensitivity of the assay for early detection. A total of 1952 clinical samples were tested by the Mindray anti‐HCV, Elecsys anti‐HCV II, and Architect anti‐HCV assays. Samples with reactive results using at least one anti‐HCV assay were further tested with the recombinant immunoblot assay (RIBA). Inconsistent results were investigated by the HCV RNA assay and HCV core antigen assay. HCV infection diagnosis was made according to the results of laboratory tests and medical records.ResultsThe Mindray anti‐HCV assay and Elecsys anti‐HCV II assay detected seroconversion in an average of 12.5 days and 10.5 days, respectively, and this difference was not significant (P = .818). Of the 1952 cases, 90 were categorized as “HCV infection” and 1862 were categorized as “no HCV infection.” The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), positive likelihood ratio (LR+), and negative likelihood ratio (LR‐) of each assay were as follows: the Mindray anti‐HCV assay, 95.6%, 99.2%, 85.1%, 99.8%, 118.6 and 0.045, respectively; the Architect anti‐HCV assay, 98.9%, 95.2%, 50.0%, 99.9%, 20.69 and 0.012, respectively; and the Elecsys anti‐HCV II assay, 96.7%, 99.9%, 98.9%, 99.8%, 1799.9 and 0.033, respectively. There were significant differences in the specificity, PPV and LR+ among the three assays (P < .001). There were no significant differences in the sensitivity, NPV or LR‐ among the three assays (P > .05).ConclusionsThe Mindray anti‐HCV assay displays a similar sensitivity to the Elecsys anti‐HCV II assay with respect to the early detection of HCV infection. The Mindray anti‐HCV assay shows excellent diagnostic performance and is suitable for the screening of HCV infection.
Quantification of human C1 esterase inhibitor protein using an automated turbidimetric immunoassay
Authors: Tange Clare E. , Kaur Amrit , Verma Nisha , Hickey Alaco , Grigoriadou Sofia , Scott Chris , Kiani Sorena , Steven Rachael , Ponsford Mark , El‐Shanawany Tariq , Jolles Stephen , Harding Stephen , Parker Antony R. 
Published: July 2018

AbstractBackgroundImpaired levels or function of C1 inhibitor (C1‐INH) results in angioedema due to increased bradykinin. It is important to distinguish between angioedema related to C1‐INH deficiency and that caused by other mechanisms, as treatment options are different. In hereditary (HAE) and acquired (AAE) angioedema, C1‐INH concentration is measured to aid patient diagnosis. Here, we describe an automated turbidimetric assay to measure C1‐INH concentration on the Optilite® analyzer.MethodsLinearity, precision, and interference were established over a range of C1‐INH concentrations. The 95th percentile reference interval was generated from 120 healthy adult donors. To compare the Optilite C1‐INH assay with a predicate assay used in a clinical laboratory, samples sent for C1‐INH investigation were used. The predicate results were provided to allow comparison.ResultsThe Optilite C1‐INH assay was linear across the measuring range at the standard sample dilution. Intra and interassay variability was <6%. The 95th percentile adult reference interval for the assay was 0.21‐0.38 g/L. There was a strong correlation between the Optilite concentrations and those generated with the predicate assay (R2 = 0.94, P < 0.0001, slope y = 0.83x). All patients with Type I HAE (n = 24) and AAE (n = 3) tested had concentrations below the measuring range in both assays, while all patients with unspecified angioedema (UAE), not diagnosed with HAE or AAE had values within the reference range.ConclusionThe Optilite assay allows the automated and precise quantification of C1‐INH concentrations in patient samples. It could therefore be used as a tool to aid the investigation of patients with angioedema.
The influence of sense of community on the relationship between community participation and mental health for individuals with serious mental illnesses
Authors: Terry Rachel , Townley Greg , Brusilovskiy Eugene , Salzer Mark S. 
Published: July 2018

AbstractThe goal of the current study is to better understand the association between community participation and mental health by investigating sense of community as a potential mediating factor between community participation, psychological distress, and mental health functioning. A survey was administered to 300 adults with serious mental illnesses using community mental health services in the United States in a cross‐sectional design. Hayes PROCESS macro (model 4, version 2.16; Hayes, 2013) was employed to test all of the hypotheses. Results indicate that sense of community partially mediated the association between community participation and psychological distress, as well as mental health functioning. Implications include contributing to the current knowledge base about the influence of community factors on mental health and informing future interventions aimed at promoting community participation of adults with serious mental illnesses.
Analytical modeling of channel potential and threshold voltage of triple material gate AlGaN/GaN HEMT including trapped and polarization‐induced charges
Authors: Kashem Md Tashfiq Bin , Subrina Samia 
Published: July 2018

AbstractWe have developed an analytical model of channel potential and threshold voltage of a gate‐engineered heterostructure transistor, triple material gate aluminum gallium nitride (AlGaN)/gallium nitride (GaN) high electron mobility transistor (HEMT). Two steps in channel potential profile lead to suppression of short channel effects. For accurate modeling of the device, spontaneous and piezoelectric polarization‐induced charges at the AlGaN/GaN interface and temperature and mole fraction dependence of device parameters are considered. The impact of trapped charges formed because of process defects during device growth is also analyzed. The device performance is studied with the variation in device parameters, and superior performance of triple material gate HEMT over other HEMT structures is observed in terms of reduced short channel effects and enhanced carrier velocity. Results from the proposed analytical model are validated against the data obtained from a commercially available numerical device simulator.
Selenium positively affects the proteome of 3 × Tg‐AD mice cortex by altering the expression of various key proteins: unveiling the mechanistic role of selenium in AD prevention
Authors: Iqbal Javed , Zhang Kaoyuan , Jin Na , Zhao Yuxi , Liu Qiong , Ni Jiazuan , Shen Liming 
Published: July 2018

AbstractSelenium (Se) deficiency is believed to be involved in pathogenesis of Alzheimer's disease (AD) due to failure of antioxidant system. Its supplementation may restore the antioxidant system and compensate the impairments caused by AD. Present study reveals the effect of Se on the proteomic changes in cortex within triple transgenic male AD mice (3 × Tg‐AD) after 4 months sodium selenate supplementation. Using iTRAQ comparative proteomics approach, 142 proteins found significant alterations with 96 down‐regulated and 46 up‐regulated proteins in the cortices of AD mice in comparison with the wild non‐transgenic type mice. On treatment with sodium selenate, 41 proteins showed reverse expression, that is, thirty three proteins were down‐regulated in AD mice but up‐regulated in selenate treated AD mice while eight up‐regulated proteins in AD mice showed lower expression in selenate treated mice. OmicsBean bioinformatics analysis revealed that Se positively affected the proteins vital in biological process, structural cores, and molecular functions, which include metabolic proteins, structural proteins, signaling molecules, oxidative stress balancers, and proteosomal degradation proteins. Results of mass spectrometry (MS) were further confirmed by Western blot analysis of five important proteins, prompting the authenticity of the MS results. This paper fills the protein‐based molecular gap between AD and Se‐treatment, and it provides a full view of Se in reversing the change of cortical protein levels during AD formation.
Feasibility and effects of a self‐assembling peptide as a scaffold in bone healing: An in vivo study in rabbit lumbar posterolateral fusion and tibial intramedullary models
Authors: Ando Kei , Imagama Shiro , Kobayashi Kazuyoshi , Ito Kenyu , Tsushima Mikito , Morozumi Masayoshi , Tanaka Satoshi , Machino Masaaki , Ota Kyotaro , Nishida Koji , Nishida Yoshihiro , Ishiguro Naoki 
Published: July 2018

ABSTRACTSpinal fusion and bone defects after injuries, removal of bone tumors, and infections require repair by implantation. In this study, we show self‐assembling peptide (SPG‐178) hydrogel‐induced bone healing in vivo. Posterolateral lumbar fusion and tibial intramedullary models of rabbits were prepared. In the tibia model, micro‐CT analysis revealed a significantly higher degree of newly formed bone matrix in the SPG‐178 group compared to the other groups. SEM/3D micrographs showed that the cavity filled with SPG‐178 had collagen fibers attached to host bone. After 28 days, samples from the SPG‐178 group showed significant repair of the defect. In the posterolateral lumbar fusion models, micro‐CT showed a tendency for a higher degree of newly formed bone matrix in the SPG‐178 group compared to the β‐TCP and bone chips only groups. Von Kossa staining showed marked new bone formation attached to the lamina that was most prominent at the implanted SPG‐178 composite margin. SPG‐178 is a material that is likely to be used in clinical applications because it has several benefits. These include its favorable bone conduction properties, its ability to act as a support for various cells and growth factors, its lack of infection risk compared with materials of animal origin such as ECM, and the ease with which it can be used to fill defects with complex shapes and be combined with a wide range of other materials. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:3285–3293, 2018.
Variability of Tempranillo grape composition in the Rioja DOCa (Spain) related to soil and climatic characteristics
Authors: Ramos María Concepción , Martínez de Toda Fernando 
Published: July 2018

AbstractBACKGROUNDSoil and climate are terroir elements that condition vine response. This research was intended to evaluate the variability of grape composition of the Vitis vinifera L. cv. Tempranillo in the Qualified Designation of Origin Rioja (DOCa) (Spain) in La Rioja (Spain), and its relationships with soil and climate characteristics.RESULTSThe relationships between grape composition (sugar content, acidity, phenolic compounds, and berry weight) and climate characteristics were analyzed for the period 2008–2017 in 20 plots scattered throughout Rioja Alta and Rioja Baja, using multiple‐regression analysis. The spatial variability of grape composition and the effect of soil properties were evaluated using cluster analysis. Despite the high variability in climate characteristics from year to year, it was possible to define the soil and plot characteristics that affect grape composition at ripening.CONCLUSIONAcidity and anthocyanin concentrations were affected by temperature and by precipitation recorded in different time periods throughout the growing cycle. The increase in temperature in earlier stages reduced the total acidity and increased the total polyphenols, while an increase in temperature during the ripening period produced a decrease in total acidity, malic acid, and anthocyanin concentration, and a lower ratio between anthocyanins and sugars. The plots located in soils with higher soil water availability presented higher acidity and lower anthocyanin concentrations. © 2018 Society of Chemical Industry
Accelerated and high‐resolution cardiac T2 mapping through peripheral k‐space sharing
Authors: Darçot Emeline , Yerly Jérôme , Colotti Roberto , Masci Pier Giorgio , Chaptinel Jerome , Feliciano Helene , Bianchi Veronica , van Heeswijk Ruud B. 
Published: July 2018

PurposeTo develop high‐spatial‐resolution cardiac T2 mapping that allows for a reduced acquisition time while maintaining its precision. We implemented and optimized a new golden‐angle radial T2 mapping technique named SKRATCH (Shared k‐space Radial T2 Characterization of the Heart) that shares k‐space peripheries of T2‐weighted images while preserving their contrasts.MethodsSix SKRATCH variants (gradient‐recalled echo and balanced SSFP, free‐breathing and breath‐held, with and without a saturation preparation) were implemented, and their precision was compared with a navigator‐gated reference technique in phantoms and 22 healthy volunteers at 3 T. The optimal breath‐held SKRATCH technique was applied in a small cohort of patients with subacute myocardial infarction.ResultsThe faster free‐breathing SKRATCH technique reduced the acquisition time by 52.4%, while maintaining the precision and spatial resolution of the reference technique. Similarly, the most precise and robust breath‐held SKRATCH technique demonstrated homogenous T2 values that did not significantly differ from the navigator‐gated reference (T2 = 39.9 ± 3.4 ms versus 39.5 ± 3.4 ms, P > .20, respectively). All infarct patients demonstrated a large T2 elevation in the ischemic regions of the myocardium.ConclusionThe optimized SKRATCH technique enabled the accelerated acquisition of high‐spatial‐resolution T2 maps, was validated in healthy adult volunteers, and was successfully applied to a small initial group of patients.
Optimizing maternal fat suppression with constrained image‐based shimming in fetal MR
Authors: Gaspar Andreia S. , Nunes Rita G. , Ferrazzi Giulio , Hughes Emer J. , Hutter Jana , Malik Shaihan J. , McCabe Laura , Baruteau Kelly P. , Rutherford Mary A. , Hajnal Joseph V. , Price Anthony N. 
Published: July 2018

PurposeEcho planar imaging (EPI) is the primary sequence for functional and diffusion MRI. In fetal applications, the large field of view needed to encode the maternal abdomen leads to prolonged EPI readouts, which may be further extended due to safety considerations that limit gradient performance. The resulting images become very sensitive to water‐fat shift and susceptibility artefacts. The purpose of this study was to reduce artefacts and increase stability of EPI in fetal brain imaging, balancing local field homogeneity across the fetal brain with longer range variations to ensure compatibility with fat suppression of the maternal abdomen.MethodsSpectral Pre‐saturation with Inversion‐Recovery (SPIR) fat suppression was optimized by investigating SPIR pulse frequency offsets. Subsequently, fetal brain EPI data were acquired using image‐based (IB) shimming on 6 pregnant women by (1) minimizing B0 field variations within the fetal brain (localized IB shimming) and (2) with added constraint to limit B0 variation in maternal fat (fat constrained IB shimming).ResultsThe optimal offset for the SPIR pulse at 3 Tesla was 550 Hz. Both shimming approaches had similar performances in terms of B0 homogeneity within the brain, but constrained IB shimming enabled higher fat suppression efficiency.ConclusionOptimized SPIR in combination with constrained IB shimming can improve maternal fat suppression while minimizing EPI distortions in the fetal brain.
Adaptive SAR mass‐averaging framework to improve predictions of local RF heating near a hip implant for parallel transmit at 7 T
Authors: Destruel Aurelien , O'Brien Kieran , Jin Jin , Liu Feng , Barth Markus , Crozier Stuart 
Published: July 2018

PurposeMagnetic resonance imaging is used increasingly to scan patients with hip prostheses. We evaluated the reliability of 10 g–averaged specific absorption rate (SAR10g) to predict radiofrequency (RF) heating in tissues surrounding a hip implant at 7 T in an 8‐channel pTx hip coil. A new adaptive SAR mass‐averaging method is proposed to improve the correlation between the distribution of mass‐averaged SAR and that of tissue temperature.MethodsCurrently, RF safety standards for implants are based on temperature instead of SAR, as SAR has not been introduced with regard to exposure scenarios with implants. In this manuscript, however, adaptive SAR is proposed for fast and reliable exposure evaluation with implants, after its correlation with tissue temperature is verified. A framework to calculate adaptive SAR mass‐averaging was introduced, which uses a different averaging mass in tissues surrounding the implants and was designed to prevent the temperature from exceeding 39ºC. Predictions from SAR10g and adaptive SAR were compared with thermal simulations.ResultsThe SAR10g method failed to predict both the location and amplitude of heating in tissue near the metal implants. In some cases, the temperature far exceeded 39ºC even when SAR10g was only 70% of the maximum allowed 10 W/kg. The distributions of adaptive SAR and temperature matched in most of the configurations, and the temperature remained below 39ºC when adaptive SAR was constrained.ConclusionAdaptive SAR can accurately monitor RF heating and could be used for parallel transmit at 7 T to supplement current standards.
Head motion measurement and correction usingFIDnavigators
Authors: Wallace Tess E. , Afacan Onur , Waszak Maryna , Kober Tobias , Warfield Simon K. 
Published: July 2018

PurposeTo develop a novel framework for rapid, intrinsic head motion measurement in MRI using FID navigators (FIDnavs) from a multichannel head coil array.MethodsFIDnavs encode substantial rigid‐body motion information; however, current implementations require patient‐specific training with external tracking data to extract quantitative positional changes. In this work, a forward model of FIDnav signals was calibrated using simulated movement of a reference image within a model of the spatial coil sensitivities. A FIDnav module was inserted into a nonselective 3D FLASH sequence, and rigid‐body motion parameters were retrospectively estimated every readout time using nonlinear optimization to solve the inverse problem posed by the measured FIDnavs. This approach was tested in simulated data and in 7 volunteers, scanned at 3T with a 32‐channel head coil array, performing a series of directed motion paradigms.ResultsFIDnav motion estimates achieved mean absolute errors of 0.34 ± 0.49 mm and 0.52 ± 0.61° across all subjects and scans, relative to ground‐truth motion measurements provided by an electromagnetic tracking system. Retrospective correction with FIDnav motion estimates resulted in substantial improvements in quantitative image quality metrics across all scans with intentional head motion.ConclusionsQuantitative rigid‐body motion information can be effectively estimated using the proposed FIDnav‐based approach, which represents a practical method for retrospective motion compensation in less cooperative patient populations.
Effect of k‐space‐weighted image contrast and ultrasound focus size on the accuracy of proton resonance frequency thermometry
Authors: Svedin Bryant T. , Dillon Christopher R. , Parker Dennis L. 
Published: July 2018

PurposeTo construct a predictive model that describes how the duration and symmetry of a k‐space‐weighted image contrast (KWIC) window affects the temporal resolution of differently sized ultrasound foci when using a pseudo‐golden angle stack‐of‐stars acquisition.MethodsWe performed a modulation analysis of proton resonance frequency temperature measurements to create the temporal modulation transfer function for KWIC windows of different symmetry and temporal duration. We reconstructed simulated ultrasound heating trajectories and stack‐of‐stars k‐space data as well as experimental phantom data using the same trajectories. Images were reconstructed using symmetric and asymmetric KWIC windows of 3 different temporal durations. Simulated results were compared against temporal modulation transfer function predictions, experimental results, and the original simulated temperatures.ResultsThe temporal modulation transfer function shows that temporal resolution with KWIC reconstructions depend on the object size. The KWIC window duration affected SNR and severity of undersampling artifacts. Accuracy and response delay improved as the KWIC window duration decreased or the size of the heated region within the KWIC plane increased. Precision worsened as the window duration decreased. Using a symmetric window eliminated the response delay to heated region size but introduced a large reconstruction delay.ConclusionThe accuracy and precision of proton resonance frequency temperature measurements from a stack‐of‐stars acquisition using a sliding KWIC window reconstruction are dependent on the size of the KWIC window and the size and shape of the heated region. The temporal modulation transfer function of KWIC reconstructions for any object size can predict the temporal response to changes in signal being acquired, such as temperature and contrast enhancement.
Imaging sequence for joint myocardial T1 mapping and fat/water separation
Authors: Nezafat Maryam , Nakamori Shiro , Basha Tamer A. , Fahmy Ahmed S. , Hauser Thomas , Botnar René M. 
Published: July 2018

PurposeTo develop and evaluate an imaging sequence to simultaneously quantify the epicardial fat volume and myocardial T1 relaxation time.MethodsWe introduced a novel simultaneous myocardial T1 mapping and fat/water separation sequence (joint T1‐fat/water separation). Dixon reconstruction is performed on a dual‐echo data set to generate water/fat images. T1 maps are computed using the water images, whereas the epicardial fat volume is calculated from the fat images. A phantom experiment using vials with different T1/T2 values and a bottle of oil was performed. Additional phantom experiment using vials of mixed fat/water was performed to show the potential of this sequence to mitigate the effect of intravoxel fat on estimated T1 maps. In vivo evaluation was performed in 17 subjects. Epicardial fat volume, native myocardial T1 measurements and precision were compared among slice‐interleaved T1 mapping, Dixon, and the proposed sequence.ResultsIn the first phantom, the proposed sequence separated oil from water vials and there were no differences in T1 of the fat‐free vials (P = .1). In the second phantom, the T1 error decreased from 22%, 36%, 57%, and 73% to 8%, 9%, 16%, and 26%, respectively. In vivo there was no difference between myocardial T1 values (1067 ± 17 ms versus 1077 ± 24 ms, P = .6). The epicardial fat volume was similar for both sequences (54.3 ± 33 cm3 versus 52.4 ± 32 cm3, P = .8).ConclusionThe proposed sequence provides simultaneous quantification of native myocardial T1 and epicardial fat volume. This will eliminate the need for an additional sequence in the cardiac imaging protocol if both measurements are clinically indicated.