335 research outputs found

    Fermentation characteristics of Korean pear (Pyrus pyrifolia Nakai) puree by the Leuconostoc mesenteroides 51-3 strain isolated from Kimchi

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    A lactic acid bacterial strain showing fast growth and high acid production when cultured in Korean pear puree was isolated from Kimchi. This strain was analyzed by using the API 50 CHL kit and 16S rRNA sequencing and was thus identified as Leuconostoc mesenteroides 51-3. Korean pear puree was fermented with the L. mesenteroides 51-3 strain at 30Ā°C for 12 h. The changes in pH, titratable acidity and viable cell count during fermentation were investigated. The pH and titratable acidity of the pear puree were 4.06 and 0.66%, respectively, after 12 h of fermentation. The viable cell count of L. mesenteroides 51-3 rapidly increased to 3.7 Ɨ 109 CFU/g after 12 h of cultivation. The content of lactic acid and acetic acid was determined to be 0.138 and 0.162%, respectively, after 12 h of fermentation. When the fermented pear puree was stored at 4Ā°C, the pH, titratable acidity and viable cell count remained fairly constant for 14 days.Keywords: Fermentation, Korean pear puree, Leuconostoc mesenteroides.African Journal of Biotechnology Vol. 9(35), pp. 5735-5738, 30 August, 201

    An autoregulatory loop controlling orphan nuclear receptor DAX-1 gene expression by orphan nuclear receptor ERRĪ³

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    The estrogen receptor-related receptor gamma (ERRĪ³/ERR3/NR3B3) is a member of the nuclear receptor superfamily that activates transcription in the absence of ligand. However, the detailed mechanism of gene regulation by ERRĪ³ is not fully understood. In this study we have found that the orphan nuclear receptor ERRĪ³ activates the DAX-1 promoter, which, in turn, represses transactivation by ERRĪ³. Serial deletions of mouse DAX-1 (mDAX-1) gene promoter have revealed that the region responding to ERRĪ³ is located between āˆ’129 and āˆ’121 bp and āˆ’334 and āˆ’326 bp. Gel shift assays and chromatin immunoprecipitation (ChIP) assays demonstrated that ERRĪ³ binds directly to the mDAX-1 promoter. Site-directed mutagenesis results demonstrated that ERRE1 (āˆ’129 to āˆ’121 bp) is more important than ERRE2 (āˆ’334 to āˆ’326 bp) which is not conserved in the human DAX-1 promoter. In addition, adenovirus-mediated overexpression of ERRĪ³ induced DAX-1 gene expression in MCF-7 breast cancer cells that co-expressed ERRĪ³ and DAX-1. Moreover, yeast two-hybrid and glutathione S-transferase (GST)-pull down assays demonstrated that DAX-1 physically interacted with ERRĪ³ and inhibited ERRĪ³ transactivation, and that this interaction was dependent on the AF-2 domain of ERRĪ³. In addition, in vitro competition assays showed that DAX-1 inhibited PGC-1Ī± mediated ERRĪ³ transactivation, via competition between these two factors for the AF-2 binding domain. We thus propose a novel autoregulatory loop that controls DAX-1 gene expression by ERRĪ³

    Cystamine induces AIF-mediated apoptosis through glutathione depletion

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    AbstractCystamine and its reduced form cysteamine showed protective effects in various models of neurodegenerative disease, including Huntington's disease and Parkinson's disease. Other lines of evidence demonstrated the cytotoxic effect of cysteamine on duodenal mucosa leading to ulcer development. However, the mechanism for cystamine cytotoxicity remains poorly understood. Here, we report a new pathway in which cystamine induces apoptosis by targeting apoptosis-inducing factor (AIF). By screening of various cell lines, we observed that cystamine and cysteamine induce cell death in a cell type-specific manner. Comparison between cystamine-sensitive and cystamine-resistant cell lines revealed that cystamine cytotoxicity is not associated with unfolded protein response, reactive oxygen species generation and transglutaminase or caspase activity; rather, it is associated with the ability of cystamine to trigger AIF nuclear translocation. In cystamine-sensitive cells, cystamine suppresses the levels of intracellular glutathione by inhibiting Ī³-glutamylcysteine synthetase expression that triggers AIF translocation. Conversely, glutathione supplementation completely prevents cystamine-induced AIF translocation and apoptosis. In rats, cysteamine administration induces glutathione depletion and AIF translocation leading to apoptosis of duodenal epithelium. These results indicate that AIF translocation through glutathione depletion is the molecular mechanism of cystamine toxicity, and provide important implications for cystamine in the neurodegenerative disease therapeutics as well as in the regulation of AIF-mediated cell death

    Helicobacter pylori Infection is Associated with Elevated Low Density Lipoprotein Cholesterol Levels in Elderly Koreans

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    This study was conducted to investigate the association between Helicobacter pylori (H. pylori) infection and the lipid profile among elderly Koreans. A total of 462 subjects (mean age 66.2 Ā± 7.6 yr, 84% males) who underwent health check-up were investigated. Each subject underwent gastroduodenoscopy with gastric mucosal biopsy, and H. pylori infection was determined by histopathological examination using the updated Sydney System score. The presence of H. pylori infection was significantly associated with the elevated serum levels of total cholesterol and low density lipoprotein (LDL) cholesterol (P < 0.05 for each) in univariate analysis. H. pylori infection was not associated with triglyceride and high density lipoprotein (HDL) cholesterol levels (P > 0.05 for each). After controlling confounders, multiple logistic regression analysis showed that the odds ratio of H. pylori infection for high LDL cholesterol level (> 140 mg/dL) was 3.113 (95% confidence interval, 1.364-7.018; P = 0.007). There were no significant associations between the presence of H. pylori infection and elevated total cholesterol levels (> 200 mg/dL) in this model (P = 0.586). The results of this study demonstrate that H. pylori infection is associated with the elevated serum LDL cholesterol levels in elderly Koreans, supporting the hypothesis that H. pylori plays a role in promoting atherosclerosis by modifying lipid metabolism

    Effects of HA and NA glycosylation pattern changes on the transmission of avian influenza A(H7N9) virus in guinea pigs

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    AbstractAvian influenza H7N9 virus has posed a concern of potential human-to-human transmission by resulting in seasonal virus-like human infection cases. To address the issue of sustained human infection with the H7N9 virus, here we investigated the effects of hemagglutinin (HA) and neuraminidase (NA) N-linked glycosylation (NLG) patterns on influenza virus transmission in a guinea pig model. Based on the NLG signatures identified in the HA and NA genetic sequences of H7N9 viruses, we generated NLG mutant viruses using either HA or NA gene of a H7N9 virus, A/Anhui/01/2013, by reverse genetics on the 2009 pandemic H1N1 virus backbone. For the H7 HA NLG mutant viruses, NLG pattern changes appeared to reduce viral transmissibility in guinea pigs. Intriguingly, however, the NLG changes in the N9 NA protein, such as a removal from residue 42 or 66 or an addition at residue 266, increased transmissibility of the mutant viruses by more than 33%, 50%, and 16%, respectively, compared with a parental N9 virus. Given the effects of HA-NA NLG changes with regard to viral transmission, we then generated the HA-NA NLG mutant viruses harboring the H7 HA of double NLG addition and the N9 NA of various NLG patterns. As seen in the HA NLG mutants above, the double NLG-added H7 HA decreased viral transmissibility. However, when the NA NLG changes occurred by a removal of residue 66 and an addition at 266 were additionally accompanied, the HA-NA NLG mutant virus recovered the transmissibility of its parental virus. These demonstrate the effects of specific HA-NA NLG changes on the H7N9 virus transmission by highlighting the importance of a HA-NA functional balance

    Enhanced heat transfer is dependent on thickness of graphene films: the heat dissipation during boiling

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    Boiling heat transfer (BHT) is a particularly efficient heat transport method because of the latent heat associated with the process. However, the efficiency of BHT decreases significantly with increasing wall temperature when the critical heat flux (CHF) is reached. Graphene has received much recent research attention for applications in thermal engineering due to its large thermal conductivity. In this study, graphene films of various thicknesses were deposited on a heated surface, and enhancements of BHT and CHF were investigated via pool-boiling experiments. In contrast to the well-known surface effects, including improved wettability and liquid spreading due to micron-and nanometer-scale structures, nanometer-scale folded edges of graphene films provided a clue of BHT improvement and only the thermal conductivity of the graphene layer could explain the dependence of the CHF on the thickness. The large thermal conductivity of the graphene films inhibited the formation of hot spots, thereby increasing the CHF. Finally, the provided empirical model could be suitable for prediction of CHF.open111522Nsciescopu

    Sol-gel Processed Yttrium-doped SnO2 Thin Film Transistors

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    Y-doped SnO2 thin film transistors were successfully fabricated by means of sol-gel process. The effect of Y concentration on the structural, chemical, and electrical properties of sol-gel-processed SnO2 films was investigated via GIXRD, SPM, and XPS; the corresponding electrical transport properties of the film were also evaluated. The dopant, Y, can successfully control the free carrier concentration by suppressing the formation of oxygen vacancy inside SnO2 semiconductors due to its lower electronegativity and SEP. With an increase of Ywt%, it was observed that the crystallinity and oxygen vacancy concentration decreased, and the operation mode of SnO2 thin film transistor changed from accumulation (normally on) to enhancement mode (normally off) with a positive Vth shift. Ā© 2020 by the authors. Licensee MDPI, Basel, Switzerland.1

    Elective Laparoscopic Repair after Colonoscopic Decompression for Incarcerated Morgagni Hernia

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    Plain radiographs of an 88-year-old woman who had experienced vomiting and abdominal distention for 3 days revealed a severely obstructed ileus, and abdominopelvic computed tomography revealed an incarcerated Morgagni hernia. The endoscope was passed through the constrictions from the diaphragmatic indentations and a thin catheter was placed for decompression. The obstructive ileus regressed markedly after the procedure; the patient underwent elective laparoscopic repair of the hernia 1 week later. This is believed to be the first case of endoscopic preoperative decompression for an incarcerated Morgagni hernia
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