162 research outputs found

    Fabrication of Highly Aligned Poly(Vinyl Alcohol) Nanofibers and its Yarn by Electrospinning

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    In the conventional electrospinning method, fibers are randomly deposited and form nonwoven structures; however, highly aligned micro- or nanofiber and its yarn may only be applicable for the fields, including composites, clothing, textiles, and microelectronics. The elementary principle to obtain uniaxially arranged nanofiber array is to regulate the electric field distribution by using assistant electrode or modified collecting device. The potential applications of conventional electrospun poly(vinyl alcohol) (PVA) fiber in the preparation of ultrafine separation filters, biodegradable mats, etc., have been described by many researchers. Highly aligned PVA nanofibers were prepared using a modified electrospinning process at the optimum conditions, and a twister added modified electrospinning apparatus was used to prepare twisted nanofiber yarn. The diameter and arrangement of the electrospun PVA nanofibers were characterized using FE-SEM. To study the effect of applied voltage and rotational velocity on the alignment rate of the nanofibers, different voltages and rotational velocity were applied during modified electrospinning, keeping other parameters unchanged. To measure the melting temperature and crystallinity of aligned nanofibers, differential scanning calorimetry and X-ray diffraction measurement were performed, respectively. The fabricated highly aligned nanofiber and its yarn might have a practical use of devices for microelectronics

    Novel Natural Polymer/Medicinal Plant Extract Electrospun Nanofiber for Cosmeceutical Application

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    Zein produced from maize is a hydrophobic protein, which holds great potential for a number of industrial applications, for example, food packaging, pharmaceutical, cosmetic, and biomedical industry. Sorghum, known as important cereal crop worldwide, is a good source of various phytochemicals such as tannins, phenolic acids, anthocyanins, phytosterols, and policosanols, and these phytochemicals have great impact on human health. Poria cocos, a well‐known traditional East‐Asian medicinal plant, is found around the roots of pine trees in Korea and China. As a rapid and efficient process, electrospinning has drawn huge interest among scientists to produce nanostructured polymer materials with excellent properties. In this work, we studied the influence of co‐solvent ratio and concentration of zein/medicinal plant extract on the morphologies of nanostructured zein/medicinal plant extract nanomaterials prepared by electrospinning technique from ethanol/water solution. The zein/medicinal extract nanofibers were characterized by field‐emission scanning electron microscopy, transmission electron microscopy, thermogravimetric analysis, and differential scanning calorimetric technique. And we were to incorporate medicinal plant resources into the electro‐spun zein nanofibers by electrospinning technique to investigate the effect of medicinal extract on the morphologies, antibacterial, antioxidant, and other properties. Zein/medicinal plant extract might have a practical use as a new preservative for cosmeceutical applications

    Biochemical Markers as Predictors of In-Hospital Mortality in Patients with Severe Trauma: A Retrospective Cohort Study

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    Background Initial evaluation of injury severity in trauma patients is an important and challenging task. We aimed to assess whether easily measurable biochemical parameters (hemoglobin, pH, and prothrombin time/international normalized ratio [PT/INR]) can predict in-hospital mortality in patients with severe trauma. Methods This retrospective study involved review of the medical records of 315 patients with severe trauma and an injury severity score >15 who were managed at Gyeongsang National University Hospital between January 2005 and December 2015. We extracted the following data: in-hospital mortality, injury severity score, and initial hemoglobin level, pH, and PT/INR. The predictive values of these variables were compared using receiver operation characteristic curves. Results Of the 315 patients, 72 (22.9%) died. The in-hospital mortality rates of patients with hemoglobin levels <8.4 g/dl and ≥8.4 g/dl were 49.8% and 9.9%, respectively (P < 0.001). At a cutoff hemoglobin level of 8.4 g/dl, the sensitivity and specificity values for mortality were 81.9% and 86.4%, respectively. At a pH cutoff of 7.25, the sensitivity and specificity values for mortality were 66.7% and 77.8%, respectively; 66.7% of patients with a pH <7.25 died versus 22.2% with a pH ≥7.25 (P < 0.001). The in-hospital mortality rates for patients with PT/INR values ≥1.4 and <1.4 were 37.5% and 16%, respectively (P < 0.001; sensitivity, 37.5%; specificity, 84%). Conclusions Using the suggested cutoff values, hemoglobin level, pH, and PT/INR can simply and easily be used to predict in-hospital mortality in patients with severe trauma

    Engineering new bone tissue in vitro on highly porous poly(Α-hydroxyl acids)/hydroxyapatite composite scaffolds

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    Engineering new bone tissue with cells and a synthetic extracellular matrix (scaffolding) represents a new approach for the regeneration of mineralized tissues compared with the transplantation of bone (autografts or allografts). In the present work, highly porous poly( L -lactic acid) (PLLA) and PLLA/hydroxyapatite (HAP) composite scaffolds were prepared with a thermally induced phase separation technique. The scaffolds were seeded with osteoblastic cells and cultured in vitro . In the pure PLLA scaffolds, the osteoblasts attached primarily on the outer surface of the polymer. In contrast, the osteoblasts penetrated deep into the PLLA/HAP scaffolds and were uniformly distributed. The osteoblast survival percentage in the PLLA/HAP scaffolds was superior to that in the PLLA scaffolds. The osteoblasts proliferated in both types of the scaffolds, but the cell number was always higher in the PLLA/HAP composite scaffolds during 6 weeks of in vitro cultivation. Bone-specific markers (mRNAs encoding bone sialoprotein and osteocalcin) were expressed more abundantly in the PLLA/HAP composite scaffolds than in the PLLA scaffolds. The new tissue increased continuously in the PLLA/HAP composite scaffolds, whereas new tissue formed only near the surface of pure PLLA scaffolds. These results demonstrate that HAP imparts osteoconductivity and the highly porous PLLA/HAP composite scaffolds are superior to pure PLLA scaffolds for bone tissue engineering. © 2000 John Wiley & Sons, Inc. J Biomed Mater Res 54: 284–293, 2001Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/34419/1/16_ftp.pd

    Cu2Se-based thermoelectric cellular architectures for efficient and durable power generation

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    Thermoelectric power generation offers a promising way to recover waste heat. The geometrical design of thermoelectric legs in modules is important to ensure sustainable power generation but cannot be easily achieved by traditional fabrication processes. Herein, we propose the design of cellular thermoelectric architectures for efficient and durable power generation, realized by the extrusion-based 3D printing process of Cu2Se thermoelectric materials. We design the optimum aspect ratio of a cuboid thermoelectric leg to maximize the power output and extend this design to the mechanically stiff cellular architectures of hollow hexagonal column- and honeycomb-based thermoelectric legs. Moreover, we develop organic binder-free Cu2Se-based 3D-printing inks with desirable viscoelasticity, tailored with an additive of inorganic Se-8(2-) polyanion, fabricating the designed topologies. The computational simulation and experimental measurement demonstrate the superior power output and mechanical stiffness of the proposed cellular thermoelectric architectures to other designs, unveiling the importance of topological designs of thermoelectric legs toward higher power and longer durability

    Prediction of cognitive impairment via deep learning trained with multi-center neuropsychological test data

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    Background Neuropsychological tests (NPTs) are important tools for informing diagnoses of cognitive impairment (CI). However, interpreting NPTs requires specialists and is thus time-consuming. To streamline the application of NPTs in clinical settings, we developed and evaluated the accuracy of a machine learning algorithm using multi-center NPT data. Methods Multi-center data were obtained from 14,926 formal neuropsychological assessments (Seoul Neuropsychological Screening Battery), which were classified into normal cognition (NC), mild cognitive impairment (MCI) and Alzheimers disease dementia (ADD). We trained a machine learning model with artificial neural network algorithm using TensorFlow (https://www.tensorflow.org) to distinguish cognitive state with the 46-variable data and measured prediction accuracies from 10 randomly selected datasets. The features of the NPT were listed in order of their contribution to the outcome using Recursive Feature Elimination. Results The ten times mean accuracies of identifying CI (MCI and ADD) achieved by 96.66 ± 0.52% of the balanced dataset and 97.23 ± 0.32% of the clinic-based dataset, and the accuracies for predicting cognitive states (NC, MCI or ADD) were 95.49 ± 0.53 and 96.34 ± 1.03%. The sensitivity to the detection CI and MCI in the balanced dataset were 96.0 and 96.0%, and the specificity were 96.8 and 97.4%, respectively. The time orientation and 3-word recall score of MMSE were highly ranked features in predicting CI and cognitive state. The twelve features reduced from 46 variable of NPTs with age and education had contributed to more than 90% accuracy in predicting cognitive impairment. Conclusions The machine learning algorithm for NPTs has suggested potential use as a reference in differentiating cognitive impairment in the clinical setting.The publication costs, design of the study, data management and writing the manuscript for this article were supported by the Ministry of Education of the Republic of Korea and the National Research Foundation of Korea (NRF-2017S1A6A3A01078538), Korea Ministry of Health & Welfare, and from the Original Technology Research Program for Brain Science through the National Research Foundation of Korea funded by the Korean Government (MSIP; No. 2014M3C7A1064752)

    Clinical Benefit of Low Molecular Weight Heparin for ST-segment Elevation Myocardial Infarction Patients Undergoing Primary Percutaneous Coronary Intervention with Glycoprotein IIb/IIIa Inhibitor

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    The efficacy of low molecular weight heparin (LMWH) with low dose unfractionated heparin (UFH) during percutaneous coronary intervention (PCI) with or without glycoprotein (Gp) IIb/IIIa inhibitor compared to UFH with or without Gp IIb/IIIa inhibitor has not been elucidated. Between October 2005 and July 2007, 2,535 patients with ST elevation acute myocardial infarction (STEMI) undergoing PCI in the Korean Acute Myocardial Infarction Registry (KAMIR) were assigned to either of two groups: a group with Gp IIb/IIIa inhibitor (n=476) or a group without Gp IIb/IIIa inhibitor (n=2,059). These groups were further subdivided according to the use of LMWH with low dose UFH (n=219) or UFH alone (n=257). The primary end points were cardiac death or myocardial infarction during the 30 days after the registration. The primary end point occurred in 4.1% (9/219) of patients managed with LMWH during PCI and Gp IIb/IIIa inhibitor and 10.8% (28/257) of patients managed with UFH and Gp IIb/IIIa inhibitor (odds ratio [OR], 0.290; 95% confidence interval [CI], 0.132-0.634; P=0.006). Thrombolysis In Myocardial Infarction (TIMI) with major bleeding was observed in LMHW and UFH with Gp IIb/IIIa inhibitor (1/219 [0.5%] vs 1/257 [0.4%], P=1.00). For patients with STEMI managed with a primary PCI and Gp IIb/IIIa inhibitor, LMWH is more beneficial than UFH

    Network Clustering Revealed the Systemic Alterations of Mitochondrial Protein Expression

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    The mitochondrial protein repertoire varies depending on the cellular state. Protein component modifications caused by mitochondrial DNA (mtDNA) depletion are related to a wide range of human diseases; however, little is known about how nuclear-encoded mitochondrial proteins (mt proteome) changes under such dysfunctional states. In this study, we investigated the systemic alterations of mtDNA-depleted (ρ0) mitochondria by using network analysis of gene expression data. By modularizing the quantified proteomics data into protein functional networks, systemic properties of mitochondrial dysfunction were analyzed. We discovered that up-regulated and down-regulated proteins were organized into two predominant subnetworks that exhibited distinct biological processes. The down-regulated network modules are involved in typical mitochondrial functions, while up-regulated proteins are responsible for mtDNA repair and regulation of mt protein expression and transport. Furthermore, comparisons of proteome and transcriptome data revealed that ρ0 cells attempted to compensate for mtDNA depletion by modulating the coordinated expression/transport of mt proteins. Our results demonstrate that mt protein composition changed to remodel the functional organization of mitochondrial protein networks in response to dysfunctional cellular states. Human mt protein functional networks provide a framework for understanding how cells respond to mitochondrial dysfunctions

    Efficacy and safety of entecavir plus carnitine complex (GODEX®) compared to entecavir monotherapy in patient with ALT elevated chronic hepatitis B: randomized, multicenter open-label trials. The GOAL study

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    Background/AimsCarnitine and vitamin complex (Godex®) is widely used in patients with chronic liver disease who show elevated liver enzyme in South Korea. The purpose of this study is to identify the efficacy and safety of carnitine from entecavir combination therapy in Alanine aminotransferase (ALT) elevated Chronic Hepatitis B (CHB) patients.Methods130 treatment-naïve patients with CHB were enrolled from 13 sites. The patients were randomly selected to the entecavir and the complex of entecavir and carnitine. The primary endpoint of the study is ALT normalization level after 12 months.ResultsAmong the 130 patients, 119 patients completed the study treatment. The ALT normalization at 3 months was 58.9% for the monotherapy and 95.2% for the combination therapy (P<0.0001). ALT normalization rate at 12 months was 85.7% for the monotherapy and 100% for the combination group (P=0.0019). The rate of less than HBV DNA 300 copies/mL at 12 months was not statistically significant (P=0.5318) 75.9% for the monotherapy, 70.7% for the combination and it was. Quantification of HBsAg level was not different from the monotherapy to combination at 12 months. Changes of ELISPOT value to evaluate the INF-γ secretion by HBsAg showed the increasing trend of combination therapy compare to mono-treatment.ConclusionsALT normalization rate was higher in carnitine complex combination group than entecavir group in CHB. Combination group was faster than entecavir mono-treatment group on ALT normalization rate. HBV DNA normalization rate and the serum HBV-DNA level were not changed by carnitine complex treatment
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