97 research outputs found

    Enhancing 2D Growth of Organic Semiconductor Thin Films with Macroporous Structures via a Small-Molecule Heterointerface

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    The physical structure of an organic solid is strongly affected by the surface of the underlying substrate. Controlling this interface is an important issue to improve device performance in the organic electronics community. Here we report an approach that utilizes an organic heterointerface to improve the crystallinity and control the morphology of an organic thin film. Pentacene is used as an active layer above, and m-bis(triphenylsilyl) benzene is used as the bottom layer. Sequential evaporations of these materials result in extraordinary morphology with far fewer grain boundaries and myriad nanometre-sized pores. These peculiar structures are formed by difference in molecular interactions between the organic layers and the substrate surface. The pentacene film exhibits high mobility up to 6.3 cm(2)V(-1)s(-1), and the pore-rich structure improves the sensitivity of organic-transistor-based chemical sensors. Our approach opens a new way for the fabrication of nanostructured semiconducting layers towards high-performance organic electronics.X116049Nsciescopu

    Coprinus comatus Cap Inhibits Adipocyte Differentiation via Regulation of PPARĪ³ and Akt Signaling Pathway

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    This study assessed the effects of Coprinus comatus cap (CCC) on adipogenesis in 3T3-L1 adipocytes and the effects of CCC on the development of diet-induced obesity in rats. Here, we showed that the CCC has an inhibitory effect on the adipocyte differentiation of 3T3-L1 cells, resulting in a significant decrease in lipid accumulation through the downregulation of several adipocyte specific-transcription factors, including CCAAT/enhancer binding protein Ī², C/EBPĪ“, and peroxisome proliferator-activated receptor gamma (PPARĪ³). Moreover, treatment with CCC during adipocyte differentiation induced a significant down-regulation of PPARĪ³ and adipogenic target genes, including adipocyte protein 2, lipoprotein lipase, and adiponectin. Interestingly, the CCC treatment of the 3T3-L1 adipocytes suppressed the insulin-stimulated Akt and GSK3Ī² phosphorylation, and these effects were stronger in the presence of an inhibitor of Akt phosphorylation, LY294002, suggesting that CCC inhibited adipocyte differentiation through the down-regulation of Akt signaling. In the animal study, CCC administration significantly reduced the body weight and adipose tissue weight of rats fed a high fat diet (HFD) and attenuated lipid accumulation in the adipose tissues of the HFD-induced obese rats. The size of the adipocyte in the epididymal fat of the CCC fed rats was significantly smaller than in the HFD rats. CCC treatment significantly reduced the total cholesterol and triglyceride levels in the serum of HFD rats. These results strongly indicated that the CCC-mediated decrease in body weight was due to a reduction in adipose tissue mass. The expression level of PPARĪ³ and phospho-Akt was significantly lower in the CCC-treated HFD rats than that in the HFD obesity rats. These results suggested that CCC inhibited adipocyte differentiation by the down-regulation of major transcription factor involved in the adipogenesis pathway including PPARĪ³ through the regulation of the Akt pathway in 3T3-L1 cells and HFD adipose tissue

    An Ultrathin Conformable Vibration-Responsive Electronic Skin for Quantitative Vocal Recognition

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    Flexible and skin-attachable vibration sensors have been studied for use as wearable voice-recognition electronics. However, the development of vibration sensors to recognize the human voice accurately with a flat frequency response, a high sensitivity, and a flexible/conformable form factor has proved a major challenge. Here, we present an ultrathin, conformable, and vibration-responsive electronic skin that detects skin acceleration, which is highly and linearly correlated with voice pressure. This device consists of a crosslinked ultrathin polymer film and a hole-patterned diaphragm structure, and senses voices quantitatively with an outstanding sensitivity of 5.5 V Pa-1 over the voice frequency range. Moreover, this ultrathin device (<5 mu m) exhibits superior skin conformity, which enables exact voice recognition because it eliminates vibrational distortion on rough and curved skin surfaces. Our device is suitable for several promising voice-recognition applications, such as security authentication, remote control systems and vocal healthcare.11Ysciescopu

    Maysin and Its Flavonoid Derivative from Centipedegrass Attenuates Amyloid Plaques by Inducting Humoral Immune Response with Th2 Skewed Cytokine Response in the Tg (APPswe, PS1dE9) Alzheimer\u27s Mouse Model

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    Alzheimer\u27s disease (AD) is a slow, progressive neurodegenerative disease and the most common type of dementia in the elderly. The etiology of AD and its underlying mechanism are still not clear. In a previous study, we found that an ethyl acetate extract of Centipedegrass (CG) (i.e., EA-CG) contained 4 types of Maysin derivatives, including Luteolin, Isoorientin, Rhamnosylisoorientin, and Derhamnosylmaysin, and showed protective effects against Amyloid beta (AĪ²) by inhibiting oligomeric AĪ² in cellular and in vitro models. Here, we examined the preventative effects of EA-CG treatment on the AĪ² burden in the Tg (Mo/Hu APPswe PS1dE9) AD mouse model. We have investigated the EA-CG efficacy as novel anti-AD likely preventing amyloid plaques using immunofluorescence staining to visually analyze AĪ²40/42 and fibril formation with Thioflavin-S or 6E10 which are the profile of immunoreactivity against epitope AĪ²1-16 or neuritic plaque, the quantitation of humoral immune response against AĪ², and the inflammatory cytokine responses (Th1 and Th2) using ELISA and QRT-PCR. To minimize the toxicity of the extracted CG, we addressed the liver toxicity in response to the CG extract treatment in Tg mice using relevant markers, such as aspartate aminotransferase (AST)/ alanine aminotransferase (ALT) measurements in serum. The EA-CG extract significantly reduced the AĪ² burden, the concentration of soluble AĪ²40/42 protein, and fibril formation in the hippocampus and cortex of the Tg mice treated with EA-CG (50 mg/kg BW/day) for 6 months compared with the Tg mice treated with a normal diet. Additionally, the profile of anti-inflammatory cytokines revealed that the levels of Th2 (interleukin-4 (IL-4) and interleukin-10 (IL-10)) cytokines are more significantly increased than Th1 (interferon-Ī³ (IFN-Ī³), interleukin-2(IL-2)) in the sera. These results suggest that the EA-CG fraction induces IL-4/IL-10-dependent anti-inflammatory cytokines (Th2) rather than pro-inflammatory cytokines (Th1), which are driven by IL-2/IFN-Ī³. With regard to the immune response, EA-CG induced an immunoglobulin IgG and IgM response against the EA-CG treatment in the Tg mice. Furthermore, EA-CG significantly ameliorated the level of soluble AĪ²42 and AĪ²40. Similarly, we observed that the fibril formation was also decreased by EA-CG treatment in the hippocampus and cortex after quantitative analysis with Thioflavin-S staining in the Tg brain tissues. Taken together, our findings suggested that Maysin and its derivative flavonoid compounds in the EA-CG fraction might be beneficial therapeutic treatments or alternative preventative measures to adjuvant for boosting humoral and cellular include immune response and anti-inflammation which may lead to amyloid plaque accumulation in Alzheimer\u27s patients\u27 brains

    Anticancer Effect of Nemopilema nomurai

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    Various kinds of animal venoms and their components have been widely studied for potential therapeutic applications. This study evaluated whether Nemopilema nomurai jellyfish venom (NnV) has anticancer activity. NnV strongly induced cytotoxicity of HepG2 cells through apoptotic cell death, as demonstrated by alterations of chromatic morphology, activation of procaspase-3, and an increase in the Bax/Bcl-2 ratio. Furthermore, NnV inhibited the phosphorylation of PI3K, PDK1, Akt, mTOR, p70S6K, and 4EBP1, whereas it enhanced the expression of p-PTEN. Interestingly, NnV also inactivated the negative feedback loops associated with Akt activation, as demonstrated by downregulation of Akt at Ser473 and mTOR at Ser2481. The anticancer effect of NnV was significant in a HepG2 xenograft mouse model, with no obvious toxicity. HepG2 cell death by NnV was inhibited by tetracycline, metalloprotease inhibitor, suggesting that metalloprotease component in NnV is closely related to the anticancer effects. This study demonstrates, for the first time, that NnV exerts highly selective cytotoxicity in HepG2 cells via dual inhibition of the Akt and mTOR signaling pathways, but not in normal cells

    Citrus aurantium flavonoids inhibit adipogenesis through the Akt signaling pathway in 3T3-L1 cells

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    <p>Abstract</p> <p>Background</p> <p>Obesity is a health hazard that is associated with a number of diseases and metabolic abnormalities, such as type-2 diabetes, hypertension, dyslipidemia, and coronary heart disease. In the current study, we investigated the effects of <it>Citrus aurantium </it>flavonoids (CAF) on the inhibition of adipogenesis and adipocyte differentiation in 3T3-L1 cells.</p> <p>Methods</p> <p>During adipocyte differentiation, 3T3-L1 cells were treated with 0, 10, and 50 Ī¼g/ml CAF, and then the mRNA and protein expression of adipogenesis-related genes was assayed. We examined the effect of CAF on level of phosphorylated Akt in 3T3-L1 cells treated with CAF at various concentrations during adipocyte differentiation.</p> <p>Results</p> <p>The insulin-induced expression of C/EBPĪ² and PPARĪ³ mRNA and protein were significantly down-regulated in a dose-dependent manner following CAF treatment. CAF also dramatically decreased the expression of C/EBPĪ±, which is essential for the acquisition of insulin sensitivity by adipocytes. Moreover, the expression of the aP2 and FAS genes, which are involved in lipid metabolism, decreased dramatically upon treatment with CAF. Interestingly, CAF diminished the insulin-stimulated serine phosphorylation of Akt (Ser473) and GSK3Ī² (Ser9), which may reduce glucose uptake in response to insulin and lipid accumulation. Furthermore, CAF not only inhibited triglyceride accumulation during adipogenesis but also contributed to the lipolysis of adipocytes.</p> <p>Conclusions</p> <p>In the present study, we demonstrate that CAF suppressed adipogenesis in 3T3-L1 adipocytes. Our results indicated that CAF down-regulates the expression of C/EBPĪ² and subsequently inhibits the activation of PPARĪ³ and C/EBPĪ±. The anti-adipogenic activity of CAF was mediated by the inhibition of Akt activation and GSK3Ī² phosphorylation, which induced the down-regulation of lipid accumulation and lipid metabolizing genes, ultimately inhibiting adipocyte differentiation.</p

    Rubus Crataegifolius Bunge Regulates Adipogenesis Through Akt and Inhibits High-Fat Diet-Induced Obesity in Rats

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    BACKGROUND: Obesity is one of the greatest public health problems and major risk factors for serious metabolic diseases and significantly increases the risk of premature death. The aim of this study was to determine the inhibitory effects of Rubus crataegifolius Bunge (RCB) on adipocyte differentiation in 3 T3-L1 cells and its anti-obesity properties in high fat diet (HFD)-induced obese rats. METHODS: 3 T3-L1 adipocytes and HFD-induced obese rats were treated with RCB, and its effect on gene expression was analyzed using RT-PCR and Western blotting experiments. RESULTS: RCB treatment significantly inhibited adipocyte differentiation by suppressing the expression of C/EBPĪ², C/EBPĪ±, and PPARĪ³ in the 3 T3-L1 adipocytes. Subsequently, the expression of the PPARĪ³ target genes aP2 and fatty acid synthase (FAS) decreased following RCB treatment during adipocyte differentiation. In uncovering the specific mechanism that mediates the effects of RCB, we demonstrated that the insulin-stimulated phosphorylation of Akt strongly decreased and that its downstream substrate phospho-GSK3Ī² was downregulated following RCB treatment in the 3 T3-L1 adipocytes. Moreover, LY294002, an inhibitor of Akt phosphorylation, exerted stronger inhibitory effects on RCB-mediated suppression of adipocyte differentiation, leading to the inhibition of adipocyte differentiation through the downregulation of Akt signaling. An HFD-induced obesity rat model was used to determine the inhibitory effects of RCB on obesity. Body weight gain and fat accumulation in adipose tissue were significantly reduced by the supplementation of RCB. Moreover, RCB treatment caused a significant decrease in adipocyte size, associated with a decrease in epididymal fat weight. The serum total cholesterol (TC) and triglyceride (TG) levels decreased in response to RCB treatment, whereas HDL cholesterol (HDL-C) increased, indicating that RCB attenuated lipid accumulation in adipose tissue in HFD-induced obese rats. CONCLUSION: Our results demonstrate an inhibitory effect of RCB on adipogenesis through the reduction of the adipogenic factors PPARĪ³, C/EBPĪ±, and phospho-Akt. RCB had a potent anti-obesity effect, reducing body weight gain in HFD-induced obese rats

    Helicobacter pylori infection combined with DENA revealed altered expression of p53 and 14-3-3 isoforms in Guloāˆ’/āˆ’ mice

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    AbstractUnlike most other mammals, human bodies do not have the ability to synthesize vitamin C inside of their own bodies. Therefore, humans must obtain vitamin C through daily diet. Guloāˆ’/āˆ’ mice strain is known with deficiency, in which vitamin C intake can be controlled by diet like human, and would be valuable for investigating the molecular mechanism of various diseases. In the present study, we established Guloāˆ’/āˆ’ mice model and investigated the differentially expressed proteins in stomach tissue of Guloāˆ’/āˆ’ mice after Helicobacter pylori-infected, and followed by DENA, using immunohistochemistry and proteomic approach. The results of immunohistochemistry analysis of stomach tissue showed that the tumor suppressor, p53 protein, expression was significantly decreased (p<0.05) but not messenger RNA (mRNA) transcriptional level, and 14-3-3Īµ, 14-3-3Ī“, Ki-67 and cleaved caspase 3 expressions were significantly increased (p<0.05) by H. Pylori infection, and followed by DENA treatment in Guloāˆ’/āˆ’ mice. Moreover, knockdown of 14-3-3 isoforms (14-3-3Īµ, 14-3-3Ļƒ, 14-3-3Ī¶ and 14-3-3Ī·) were significantly increased sub-G1 phase (characteristics of apoptosis) in AGS cells and, phenotypic changes like cell shrinkage, density and cleaved nuclei were also observed. Proteome analyses showed that 14-3-3Ļƒ, 14-3-3Ī·, and tropomyosin alpha-1 chain were down-regulated, and Hspd1 protein and HSC70 were up-regulated after H. Pylori-infection, and followed by DENA. The combined results of immunohistochemistry and proteomic analysis suggest that H. pylori altered the p53 and 14-3-3 isoforms expression and DENA further enhanced the H. pylori effect, which might be involved in carcinogenesis and metastasis of gastric cancer on Guloāˆ’/āˆ’ mice

    Parathyroidectomy versus cinacalcet in the treatment of tertiary hyperparathyroidism after kidney transplantation: a retrospective study

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    Background Hyperparathyroidism is common in patients with chronic kidney disease with reduced renal function and has been observed after kidney transplantation. The optimal treatment for cases in which hyperparathyroidism persists after kidney transplantation has not been determined. Methods This retrospective study included 83 patients with tertiary hyperparathyroidism who underwent kidney transplantation between 2000 and 2018 at a single tertiary center in Korea. Sixty-four patients underwent parathyroidectomy and 19 patients were treated with cinacalcet following renal transplantation. Biochemical parameters and clinical outcomes were compared between the two groups. Results Serum calcium and parathyroid hormone (PTH) levels improved in both the parathyroidectomy and cinacalcet groups. One year after treatment, parathyroidectomy resulted in a lower mean serum calcium level than cinacalcet (9.7 Ā± 0.7 mg/dL vs. 10.5 Ā± 0.7 mg/dL, p = 0.001). Regarding serum PTH, the parathyroidectomy group showed a significantly lower PTH level than the cinacalcet group at 6 months (129.1 Ā± 80.3 pg/mL vs. 219.2 Ā± 92.5 pg/mL, p = 0.002) and 1 year (118.8 Ā± 75.5 pg/mL vs. 250.6 Ā± 94.5 pg/mL, p < 0.001). There was no statistically significant difference in the incidence of kidney transplant rejection, graft failure, cardiovascular events, fracture risk, or bone mineral density changes between the two groups. Conclusion Parathyroidectomy appears to reduce PTH and calcium levels effectively in tertiary hyperparathyroidism. However, creatinine level and allograft rejection should be monitored closely

    Drug Resistance Rates of Mycobacterium tuberculosis at a Private Referral Center in Korea

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    The goals of this study were to identify first-line drug resistance in new and previously treated tuberculosis (TB) cases and to determine risk factors for multidrug-resistant TB (MDR-TB) at a private referral center in Korea. All patients with culture-confirmed pulmonary TB over a 2-yr period between July 2002 and June 2004 were prospectively included in this study. In total, 637 patients were included; 512 (80.4%) were new cases, and 125 (19.6%) were previously treated cases. Resistance to at least one first-line drug was identified in 11.7% of new cases and 41.6% of previously treated cases. MDR-TB was detected in 3.9% of new cases and 27.2% of previously treated cases. The proportion of extensively drug-resistant TB among MDR-TB patients was 16.7% (9/54). Factors associated with MDR-TB included age under 45 yr, previous TB treatment, and the presence of cavitation on chest radiography. Rates of first-line drug resistance are high, particularly in previously treated patients, in the private sector in Korea. This underscores the need for an improved control program, coupled with early diagnosis of MDR-TB, to reduce the spread and development of resistance
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