286 research outputs found

    Beyond slurry-cast supercapacitor electrodes: PAN/MWNT heteromat-mediated ultrahigh capacitance electrode sheets

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    Supercapacitors (SCs) have garnered considerable attention as an appealing power source for forthcoming smart energy era. An ultimate challenge facing the SCs is the acquisition of higher energy density without impairing their other electrochemical properties. Herein, we demonstrate a new class of polyacrylonitrile (PAN)/multi-walled carbon tube (MWNT) heteromat-mediated ultrahigh capacitance electrode sheets as an unusual electrode architecture strategy to address the aforementioned issue. Vanadium pentoxide (V2O5) is chosen as a model electrode material to explore the feasibility of the suggested concept. The heteromat V2O5 electrode sheets are produced through one-pot fabrication based on concurrent electrospraying (for V2O5 precursor/MWNT) and electrospinning (for PAN nanofiber) followed by calcination, leading to compact packing of V2O5 materials in intimate contact with MWNTs and PAN nanofibers. As a consequence, the heteromat V2O5 electrode sheets offer three-dimensionally bicontinuous electron (arising from MWNT networks)/ion (from spatially reticulated interstitial voids to be filled with liquid electrolytes) conduction pathways, thereby facilitating redox reaction kinetics of V2O5 materials. In addition, elimination of heavy metallic foil current collectors, in combination with the dense packing of V2O5 materials, significantly increases (electrode sheet-based) specific capacitances far beyond those accessible with conventional slurry-cast electrodes.ope

    5′-Triphosphate-RNA-independent activation of RIG-I via RNA aptamer with enhanced antiviral activity

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    RIG-I is a cytosolic receptor for non-self RNA that mediates immune responses against viral infections through IFNα/β production. In an attempt to identify novel tools that modulate IFNα/β production, we used SELEX technology to screen RNA aptamers that specifically target RIG-I protein. Most of the selected RIG-I aptamers contained polyU motifs in the second half regions that played critical roles in the activation of RIG-I-mediated IFNβ production. Unlike other known ligands, RIG-I aptamer bound and activated RIG-I in a 5′-triphosphate-independent manner. The helicase and RD domain of RIG-I were used for aptamer binding, but intact RIG-I protein was required to exert aptamer-mediated signaling activation. Furthermore, replication of NDV, VSV and influenza virus in infected host cells was efficiently blocked by pre- or post-treatment with RIG-I aptamer. Based on these data, we propose that RIG-I aptamer has strong potential to be an antiviral agent that specifically boosts the RIG-I-dependent signaling cascade

    Structure and Electrochemical Performance of Carbide-Derived Carbon Nanopowders

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    Microporous carbon materials are widely used in gas storage, sorbents, supercapacitor electrodes, water desalination, and catalyst supports. While these microporous carbons usually have a particle size in the 1–100 μm range, here the synthesis of porous carbide‐derived carbon (CDC) with particle diameters around 30 nm by extraction of titanium from nanometer‐sized titanium carbide (TiC) powder at temperatures of 200 °C and above is reported. Nanometer‐sized CDCs prepared at 200–400 °C show a disordered structure and the presence of CN sp1 bonds. Above 400 °C, the CN bond disappears with the structure transition to disordered carbon similar to that observed after synthesis from carbide micropowders. Compared to CDCs produced from micrometer‐sized TiC, nano‐CDC has a broader pore size distribution due to interparticle porosity and a large contribution from the surface layers. The material shows excellent electrochemical performance due to its easily accessible pores and a large specific surface area

    A Toxicological Study of HangAmDan-B in Mice

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    AbstractThe aim of the study was to define the toxicity of HangAmDan-B (HAD-B) in mice over the short and long term. HAD-B was studied in 1-week single and 5-week repeated oral dose toxicity tests on male Imprinting Control Region mice. Doses used in 1 week single oral dose toxicity tests were 0, 0.2, 1, 5, and 25 g/kg/day and those of repeated toxicity test were 0, 0.04, 0.2, 1, and 2 g/kg/day. Blood and urine samples were assayed and their morphology observed. Numerical data were compared using Mann-Whitney U test and analysis of variance. Significantly decreased red blood cell levels in mice from S2-HAD-B, S3-HAD-B, S4-HAD-B, and S5-HAD-B groups were observed in single oral dose toxicity tests. Hemoglobin, hematocrit, and mean cell hemoglobin values in mice from the S4-HAD-B and S5-HAD-B groups were also significantly decreased. No mortalities or significant differences in all factors were observed during the dosing period of the repeated dose toxicity test. Administering 2 g/kg/day of HAD-B in mice over a 5-week period showed no significant hematological changes. However, risk of anemia with more than 5 g/kg/ day administration of HAD-B was found. In general, HAD-B appears to be safe and nontoxic, and a no observed adverse effect level in mice was established at 2 g/kg/ day. This data serves as satisfactory preclinical evidence for the safety of HAD-B should a future clinical trial for HAD-B be launched. Further studies are required to confirm these safety results and to carry out a safety trial in humans

    Validation and Reliability of a Smartphone Application for the International Prostate Symptom Score Questionnaire: A Randomized Repeated Measures Crossover Study

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    Background: Smartphone-based assessment may be a useful diagnostic and monitoring tool for patients. There have been many attempts to create a smartphone diagnostic tool for clinical use in various medical fields but few have demonstrated scientific validity. Objective: The purpose of this study was to develop a smartphone application of the International Prostate Symptom Score (IPSS) and to demonstrate its validity and reliability. Methods: From June 2012 to May 2013, a total of 1581 male participants (>= 40 years old), with or without lower urinary tract symptoms (LUTS), visited our urology clinic via the health improvement center at Soonchunhyang University Hospital (Republic of Korea) and were enrolled in this study. A randomized repeated measures crossover design was employed using a smartphone application of the IPSS and the conventional paper form of the IPSS. Paired t test under a hypothesis of non-inferior trial was conducted. For the reliability test, the intraclass correlation coefficient (ICC) was measured. Results: The total score of the IPSS (P=.289) and each item of the IPSS (P=.157-1.000) showed no differences between the paper version and the smartphone version of the IPSS. The mild, moderate, and severe LUTS groups showed no differences between the two versions of the IPSS. A significant correlation was noted in the total group (ICC=.935, P<.001). The mild, moderate, and severe LUTS groups also showed significant correlations (ICC=.616,.549, and .548 respectively, all P<.001). There was selection bias in this study, as only participants who had smartphones could participate. Conclusions: The validity and reliability of the smartphone application version were comparable to the conventional paper version of the IPSS. The smartphone application of the IPSS could be an effective method for measuring lower urinary tract symptoms.X1144Ysciescopu

    First Successful Application of Preimplantation Genetic Diagnosis for Lethal Neonatal Rigidity and Multifocal Seizure Syndrome in Korea: A Case Report

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    Lethal neonatal rigidity and multifocal seizure syndrome (RMFSL) is a severe autosomal recessive epileptic encephalopathy characterized by rigidity, intractable multifocal seizures, microcephaly, apnea, and bradycardia immediately after birth. RMFSL is related to a mutation in breast cancer 1-associated ataxia telangiectasia mutated activation-1 protein (BRAT1). We report a case of a female infant born to non-consanguineous Korean parents who developed hypertonia, dysmorphic features, progressive encephalopathy with refractory seizures at birth, and worsening intermittent apnea, leading to intubation and death at 137 days of age. The initial repeated electroencephalographic findings were normal; however, a pattern of focal seizures emerged at 35 days of life. Rapid trio whole-exome sequencing revealed heterozygous mutations c.1313_1314delAG p.(Gln438Argfs*51) and c.1276C>T p. (Gln426*) in BRAT1. After genetic counseling for pregnancy planning, a preimplantation genetic diagnosis for targeted BRAT1 mutations was successfully performed, and a healthy baby was born. To our knowledge, this is the first reported case of a Korean patient with compound heterozygous mutations in BRAT1. An early and accurate genetic diagnosis can help provide timely treatment to patients and indicate the need for reproductive counseling for parents for family planning

    A Case of Colovesical Fistula Induced by Sigmoid Diverticulitis

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    Colonic diverticulosis has continuously increased, noticeably left-sided diseases, in Korea. A colovesical fistula is an uncommon complication of diverticulitis, and its most common cause is diverticular disease. Confirmation of its presence generally depends on clinical findings, such as pneumaturia and fecaluria. The primary aim of a diagnostic workup is not to observe the fistular tract itself but to find the etiology of the disease so that an appropriate therapy can be initiated. We present here the case of a 79-year-old man complaining of pneumaturia and fecaluria. On abdomen and pelvis CT, the patient was diagnosed as having a colovesical fistula due to sigmoid diverticulitis. After division of the adhesion between the sigmoid colon and the bladder, the defect of the bladder wall was repaired by simple closure. The colonic defect was treated with a segmental resection, including the rectosigmoid junction. The patient is doing well at 6 months after the operation and shows no evidence of recurrence of the fistula

    A Case of Cushing's Syndrome Presenting as Endometrial Hyperplasia

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    We describe here the case of a 39-year-old woman with a cortisol-producing adrenal adenoma and she presented with endometrial hyperplasia and hypertension without the specific characteristics of Cushing's syndrome. The patient had consulted a gynecologist for menometrorrhagia 2 years prior to her referral and she was diagnosed with endometrial hyperplasia and hypertension. Her blood pressure and the endometrial lesion were refractory despite taking multiple antihypertensives and repetitive dilation and curettage and progestin treatment. On admission, the clinical examination revealed mild central obesity (a body mass index of 22.9 kg/m2, a waist circumference of 85 cm and a hip circumference of 94cm), but there was no hirsutism and myopathy. She showed impaired glucose tolerance on an oral glucose tolerance test. The biochemical hypercortisolemia together with the prolactin and androgen levels were evaluated to explore the cause of her anovulation. Adrenal Cushing's syndrome was confirmed on the basis of the elevated urinary free cortisol (454 µg/24h, normal range: 20-70) with a suppressed ACTH level (2.0 pg/mL, normal range: 6.0-76.0) and the loss of circadian cortisol secretion. A CT scan revealed a 3.1 cm, hyperechoic, well-marginated mass in the left adrenal gland. Ten months post-adrenalectomy, the patient had unintentionally lost 9 kg of body weight, had regained a regular menstrual cycle and had normal thickness of her endometrium
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