Chonbuk National University

About: Chonbuk National University is a education organization based out in Jeonju, South Korea. It is known for research contribution in the topics: Apoptosis & Nanofiber. The organization has 14820 authors who have published 28884 publications receiving 554131 citations.

Electronic structures of GaN edge dislocations

Abstract: We investigate atomic and electronic structures of the threading edge dislocations of GaN using self-consistent-charge density-functional tight-binding approaches. Full-core, open-core, Ga-vacancy, and N-vacancy edge dislocations are fully relaxed in our total-energy scheme. The Ga-vacancy dislocation is the most stable in a wide range of Ga chemical potentials, whereas full-core and open-core dislocations are more stable than others in the Ga-rich region. Partial dehybridization takes place during the lattice relaxation near the dislocation in all cases. The dangling bonds at Ga atoms mostly contribute to the deep-gap states, whereas those at N atoms contribute to the valence-band tails. All the edge dislocations can act as deep trap centers, except the Ga-vacancy dislocation, which may act as an origin of yellow luminescence.

Revision and update on clinical practice guideline for liver cirrhosis

Abstract: Liver cirrhosis (LC) is a disease with a high rate of prevalence and one of the most common causes of mortality in the Republic of Korea (hereafter "Korea"). In Korea, the main etiologies of LC have been found to be chronic hepatitis B (CHB), alcohol, and chronic hepatitis C (CHC). In patients with complications such as ascites, variceal bleeding, and encephalopathy, the 5-year survival rates were 32%, 21%, and 40%, respectively, reflecting the poor prognosis of patients with LC. Consequently, a clinical practice guideline appropriate for the medical milieu of Korea is important for both patients and clinicians. In 2005, the Korean Association for the Study of the Liver established a guideline for the treatment of LC that is now widely used. However, it is currently necessary to revise and update the clinical practice guideline based on new evidence over the past 6 years regarding the diagnosis, treatment, and prevention of LC. Therefore, the Korean Association for the Study of the Liver undertook a revision and update of the clinical practice guideline co-organized by the Liver Cirrhosis Clinical Research Center. This guideline was based on an interdisciplinary (hepatology, radiology, pathology, and preventive medicine) approach. A panel of experts selected by the Korean Association for the Study of the Liver and Liver Cirrhosis Clinical Research Center met several times to discuss and write this guideline during 2005-2011. This guideline was written in light of published studies retrieved from MEDLINE, EMBASE, and Cochrane Library. The panel aimed to address 5 subjects: diagnosis of LC, anti-fibrotic therapy for LC, variceal bleeding, ascites, and hepatic encephalopathy. The evidence and recommendations made in this guideline have been graded according to the GRADE (Grading of Recommendations Assessment Development and Evaluation) system. The strength of evidence has been classified into 3 levels: A (high-quality evidence), B (moderate-quality evidence), and C (low-quality evidence). The strength of recommendation has been classified into 2 categories: strong and weak (Table 1). Where there was no clear evidence, the recommendations were based on the consensus expert opinion(s) in literature and that of the writing committee. Table 1 Grading evidence and recommendations 1. Diagnosis of LC LC is a pathologically defined disease, and is clinically classified as compensated and decompensated LC. Decompensated LC includes cases with ascites, variceal bleeding, hepatic encephalopathy, or jaundice. Image studies for diagnosing LC are CT, abdominal ultrasound, and MRI. Typical findings of these images are nodular liver surface, splenomegaly, and the presence of intra-abdominal collateral vessels, which mean increasing portal venous pressure. Although there are not established criteria for the diagnosis of compensated LC, imaging studies may be helpful for the diagnosis of LC b y integrating laboratory findings such as albumin, bilirubin, or prothrombin time and platelet values. 1-1. Diagnostic approach-patient history, physical examination, and laboratory tests When dealing with patients with LC, evaluation of the cause, severity, and stage is the first step. In patients with chronic liver disease, history taking (drug use, blood transfusion, or alcohol use), physical examination (jaundice, ascites, spider angioma, hepatomegaly, or splenomegaly), and symptom such as fatigue from hepatitis should be assessed. In patients with LC, a whole blood test including platelet count, liver function test (albumin, aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, and gamma glutamyl transpeptidase), prothrombin time, abdominal ultrasound, abdominal CT, and endoscopy should be carried out to confirm the presence or absence of cirrhosis. In addition, laboratory tests for hepatitis B or C virus infection are needed for the evaluation of its cause. Generally, the Child-Pugh score is used to assess the severity of LC. In clinical practice for the diagnosis of LC, findings of portal hypertension such as ascites, hepatic encephalopathy, or varices, imaging findings, and laboratory findings are common diagnostic tools. Recently, it was found that nodularity of the liver surface, a platelet count of less than 100,000/mm3, albumin less than 3.5 g/dL, and an international normalized ratio of 1.3 or more are related to the presence of LC. Presence of one condition of these findings showed a specificity of 90.42% and a sensitivity of 61.11%.1

Biosynthesis and characterization of silver nanoparticles using panchakavya, an Indian traditional farming formulating agent.

Abstract: Synthesis of silver nanoparticles (AgNPs) with biological properties is of vast significance in the development of scientifically valuable products. In the present study, we describe simple, unprecedented, nontoxic, eco-friendly, green synthesis of AgNPs using an Indian traditional farming formulating agent, panchakavya. Silver nitrate (1 mM) solution was mixed with panchakavya filtrate for the synthesis of AgNPs. The nanometallic dispersion was characterized by surface plasmon absorbance measuring 430 nm. Transmission electron microscopy showed the morphology and size of the AgNPs. Scanning electron microscopy-energy-dispersive spectroscopy and X-ray diffraction analysis confirmed the presence of AgNPs. Fourier transform infrared spectroscopy analysis revealed that proteins in the panchakavya were involved in the reduction and capping of AgNPs. In addition, we studied the antibacterial activity of synthesized AgNPs. The synthesized AgNPs (1-4 mM) extensively reduced the growth rate of antibiotic resistant bacteria such as Aeromonas sp., Acinetobacter sp., and Citrobacter sp., according to the increasing concentration of AgNPs.