115 research outputs found
Structural and optical properties of ZnO nanorods by electrochemical growth using multi-walled carbon nanotube-composed seed layers
We reported the enhancement of the structural and optical properties of electrochemically synthesized zinc oxide [ZnO] nanorod arrays [NRAs] using the multi-walled carbon nanotube [MWCNT]-composed seed layers, which were formed by spin-coating the aqueous seed solution containing MWCNTs on the indium tin oxide-coated glass substrate. The MWCNT-composed seed layer served as the efficient nucleation surface as well as the film with better electrical conductivity, thus leading to a more uniform high-density ZnO NRAs with an improved crystal quality during the electrochemical deposition process. For ZnO NRAs grown on the seed layer containing MWCNTs (2 wt.%), the photoluminescence peak intensity of the near-band-edge emission at a wavelength of approximately 375 nm was enhanced by 2.8 times compared with that of the ZnO nanorods grown without the seed layer due to the high crystallinity of ZnO NRAs and the surface plasmon-meditated emission enhancement by MWCNTs. The effect of the MWCNT-composed seed layer on the surface wettability was also investigated
A Rare Case of Recurrent Myoid Hamartoma Mimicking Malignancy: Imaging Appearances
Myoid hamartoma is an uncommon type of breast hamartoma and its recurrence is very rare. We report the imaging appearance of an unusual case of recurrent myoid hamartoma of the breast mimicking malignancy in a 43-year-old woman. Although the mammographic and ultrasonographic findings have long been described in the literature, MR finding with a dynamic study has not, to the best of our knowledge, been reported previously
Elderly women who received Helicobacter pylori-eradicating therapy have reduced risk of low skeletal muscle mass
First Report for the Seasonal and Annual Prevalence of Flea-Borne Bartonella from Rodents and Soricomorphs in the Republic of Korea
Rodents and soricomorphs are animal hosts of fleas and associated zoonotic microbial pathogens. A total of 4,889 small mammals were collected from Gyeonggi and Gangwon Provinces, Republic of Korea, from 2008 through 2010, including: Apodemus agrarius (4,122, 84.3%), followed by Crocidura lasiura (282, 5.8%), Microtus fortis (257, 5.3%), Myodes regulus (77, 1.6%), Micromys minutus (71, 1.5%), Mus musculus (63, 1.3%), and 4 other species (17, 0.3%). A total of 1,099 fleas belonging to 10 species and 7 genera were collected. Ctenophthalmus congeneroides (724, 65.9%) was the most commonly collected flea, followed by Stenoponia sidimi (301, 27.4%), Neopsylla bidentatiformis (29, 2.6%), and Rhadinopsylla insolita (25, 2.3%). The remaining species accounted for only 1.8% (20, range 1-6) of all fleas collected. The 2 dominant flea species, C. congeneroides and S. sidimi, showed an inverse seasonal pattern, with higher populations of C. congeneroides from January-September, whereas S. sidimi was more frequently collected during October-December. The overall flea infestation rates (FIR) and flea indices (FI) were 14.1% and 0.22, respectively, and were highest during April-June (19.7% and 0.30, respectively). A total of 735 of the 1,099 fleas were assayed for the detection of Bartonella spp. by PCR using Bartonella-specific primers, of which 515 were positive for Bartonella, with an overall maximum likelihood estimate (MLE) of 700.7/1,000. The highest MLE values were observed during April-June (899.2) and July-September (936.2) trapping periods and, although lower, were similar for January-March (566.7) and October-December (574.1). C. congeneroides demonstrated high MLEs for all seasons (range 752.5-934.8), while S. sidimi was positive for Bartonella only during January-March (MLE = 342.1) and October-December (MLE = 497.2) collection periods. Continued long-term surveillance of small mammals and associated ectoparasites is needed to improve our understanding of the prevalence of Bartonella spp. in fleas and the role of fleas in the zoonotic maintenance and transmission of Bartonella to humans.OAIID:oai:osos.snu.ac.kr:snu2013-01/102/0000051105/5SEQ:5PERF_CD:SNU2013-01EVAL_ITEM_CD:102USER_ID:0000051105ADJUST_YN:YEMP_ID:A077262DEPT_CD:551CITE_RATE:2.277FILENAME:2013 vbz 13(7)457-467 flea-borne bartonella.pdfDEPT_NM:수의학과SCOPUS_YN:YCONFIRM:
Autophagy deficiency leads to protection from obesity and insulin resistance by inducing Fgf21 as a mitokine
Despite growing interest and a recent surge in papers, the role of autophagy in glucose and lipid metabolism is unclear. We produced mice with skeletal muscle–specific deletion of Atg7 (encoding autophagy-related 7). Unexpectedly, these mice showed decreased fat mass and were protected from diet-induced obesity and insulin resistance; this phenotype was accompanied by increased fatty acid oxidation and browning of white adipose tissue (WAT) owing to induction of fibroblast growth factor 21 (Fgf21). Mitochondrial dysfunction induced by autophagy deficiency increased Fgf21 expression through induction of Atf4, a master regulator of the integrated stress response. Mitochondrial respiratory chain inhibitors also induced Fgf21 in an Atf4-dependent manner. We also observed induction of Fgf21, resistance to diet-induced obesity and amelioration of insulin resistance in mice with autophagy deficiency in the liver, another insulin target tissue. These findings suggest that autophagy deficiency and subsequent mitochondrial dysfunction promote Fgf21 expression, a hormone we consequently term a 'mitokine', and together these processes promote protection from diet-induced obesity and insulin resistance
Clinical Characteristics and Etiology of Travelers' Diarrhea among Korean Travelers Visiting South-East Asia
The morbidity of travelers' diarrhea (TD) is still high. This study examined the incidence of common pathogens and characteristics of TD among Korean travelers who visited South-East Asian countries. We performed a prospective study involving 479 Korean travelers with diarrheal disease from February 2009 to April 2009 and stool samples were examined and questionnaire surveys were done after arrival. Enterotoxigenic Escherichia coli (ETEC) was found in 36.0% of TD cases, as were the following: Enteroaggregative Escherichia coli (EAEC) in 27.0%, Vibrio parahaemolyticus in 13.1%, and Norovirus in 11.5%. The detected rate of classic TD was higher in men (P = 0.007), in patients who had a shorter duration trip (P = 0.023) and in patients who drank more than 1 liter of water per day (P = 0.037). Positive stool culture rates were higher in men (P = 0.005), in hospitalized patients (P = 0.013). and in those who consumed impure water or raw foods (P = 0.033). A higher severity of disease corresponded to a significantly higher culture positivity rate (P = 0.029). We should consider the possibility of other pathogens in addition to ETEC in patients with TD who visit South-East Asia. Travelers need to educate about risk factors associated with TD
Is Myocardial Infarction in Patients without Significant Stenosis on a Coronary Angiogram as Benign as Believed?
The present study aimed to investigate the clinical characteristics and 1-year outcomes of acute myocardial infarction (AMI) patients without significant stenosis on a coronary angiogram comparison with the clinical characteristics and outcomes of patients with significant coronary artery stenosis. A total of 1,220 patients with AMI were retrospectively classified into Group I (≥50% diameter stenosis, n=1,120) and Group II (<50%, n=100). Group II was further divided into two subgroups according to the underlying etiology: cryptogenic (Group II-a, n=54) and those with possible causative factors (Group II-b, n=46). Patients in Group II were younger, were more likely to be women, and were less likely to smoke and to have diabetes mellitus than were patients in Group I. The levels of cardiac enzymes, LDL-cholesterol levels, and the apo-B/A1 ratio were lower in Group II. However, 1-month and 12-month rates of major adverse cardiac events (MACE) were not significantly different between the two groups. The Group II-b subgroup comprised 29 patients with vasospasm, 11 with myocardial bridge, and 6 with spontaneous thrombolysis. Left ventricular ejection fraction and creatinine clearance were lower and levels of N-terminal pro-brain natriuretic peptide (NT-proBNP) and high-sensitivity C-reactive protein (hs-CRP) were higher in Group II-a than in Group II-b. However, outcomes including MACE and mortality at 12 months were not significantly different between the two subgroups. The 1-year outcomes of patients in Group II were similar to those of patients in Group I. The clinical outcomes in Group II-a were also similar to those of Group II-b, although the former group showed higher levels of NT-proBNP and hs-CRP
Graphene-Based Nanocomposites for Energy Storage
Since the first report of using micromechanical cleavage method to produce graphene sheets in 2004, graphene/graphene-based nanocomposites have attracted wide attention both for fundamental aspects as well as applications in advanced energy storage and conversion systems. In comparison to other materials, graphene-based nanostructured materials have unique 2D structure, high electronic mobility, exceptional electronic and thermal conductivities, excellent optical transmittance, good mechanical strength, and ultrahigh surface area. Therefore, they are considered as attractive materials for hydrogen (H2) storage and high-performance electrochemical energy storage devices, such as supercapacitors, rechargeable lithium (Li)-ion batteries, Li–sulfur batteries, Li–air batteries, sodium (Na)-ion batteries, Na–air batteries, zinc (Zn)–air batteries, and vanadium redox flow batteries (VRFB), etc., as they can improve the efficiency, capacity, gravimetric energy/power densities, and cycle life of these energy storage devices. In this article, recent progress reported on the synthesis and fabrication of graphene nanocomposite materials for applications in these aforementioned various energy storage systems is reviewed. Importantly, the prospects and future challenges in both scalable manufacturing and more energy storage-related applications are discussed
Well-integrated ZnO nanorod arrays on conductive textiles by electrochemical synthesis and their physical properties
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