83 research outputs found

    Phase-locked loop, delay-locked loop, and linear decorrelating detector for asynchronous multirate DS-CDMA system

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    The performance of phase synchronization and code tracking of a digital phase-locked loop (PLL) and delay-locked loop (DLL), respectively, is investigated in wideband asynchronous multirate DS-CDMA system. Dynamic Partial Correlation (DPC) method is proposed to evaluate the autocorrelation and its power spectrum density (PSD) of the cross-correlated terms in the presence of multirate multiple access interference (MMAI) under additive white gaussian noise (AWGN) and fading channel environments. The steady-state probability density function (PDF) and variance of the phase estimator error and code tracking jitter is evaluated by solving the first-order Fokker-Planck equation. Among many linear multiuser detectors which decouple the multiple access interference from each of the interfering users, one-shot window linear decorrelating detector (LDD) based on a one bit period to reduce the complexity of the LDD has attracted wide attention as an implementation scheme. Therefore, we propose Hybrid Selection Diversity/ Maximal Ratio Combining (Hybrid SD/MRC) one-shot window linear decorrelating detector (LDD) for asynchronous DS-CDMA systems. The selection diversity scheme at the input of the Hybrid SD/MRC LDD is based on choosing the branch with the maximum signal-to-noise ratio (SNR) of all filter outputs. The MR Combining scheme at the output of the Hybrid SD/MRC LDD adopts to maximize the output SNR and thus compensates for the enhanced output noise. The Hybrid SD/MRC one-shot LDD with PLL is introduced to track its phase error and to improve the demodulation performance. The probability density functions of the maximum SNR of the SD combiner, the near-far resistance (NFR) of one-shot LDD by Gaussian approximation, and the maximum SNR of the MR combiner for Hybrid SD/MRC LDD are evaluated, and the bit error probability is obtained from these pdfs. The performance of Hybrid SD/MRC one-shot LDD is assessed in a Rayleigh fading channel

    Insulin and glucagon secretions, and morphological change of pancreatic islets in OLETF rats, a model of type 2 diabetes mellitus.

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    This study was performed to observe the changes of glucose-related hormones and the morphological change including ultrastructure of the pancreatic islets in the male Otsuka Long-Evans Tokushima Fatty rat. Area under the curve (AUC) of glucose at the 30th (709 plus minus 73 mg.h/dL) and at the 40th week (746 plus minus 87 mg.h/ dL) of age were significantly higher than that at the 10th week (360 plus minus 25 mg.h/ dL). AUC of insulin of the 10th week was 2.4 plus minus 0.9 ng.h/mL, increased gradually to 10.8 plus minus 8.3 ng.h/mL at the 30th week, and decreased to 1.8 plus minus 1.2 ng.h/mL at the 40th week. The size of islet was increased at 20th week of age and the distribution of peripheral alpha cells and central beta cells at the 10th and 20th weeks was changed to a mixed pattern at the 40th week. On electron microscopic examination, beta cells at the 20th week showed many immature secretory granules, increased mitochondria, and hypertrophied Golgi complex and endoplasmic reticulum. At the 40th week, beta cell contained scanty intracellular organelles and secretory granules and apoptosis of acinar cell was observed. In conclusion, as diabetes progressed, increased secretion of insulin was accompanied by increases in size of islets and number of beta-cells in male OLETF rats showing obese type 2 diabetes. However, these compensatory changes could not overcome the requirement of insulin according to the continuous hyperglycemia after development of diabetes

    The Protective Effect of Apamin on LPS/Fat-Induced Atherosclerotic Mice

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    Apamin, a peptide component of bee venom (BV), has anti-inflammatory properties. However, the molecular mechanisms by which apamin prevents atherosclerosis are not fully understood. We examined the effect of apamin on atherosclerotic mice. Atherosclerotic mice received intraperitoneal (ip) injections of lipopolysaccharide (LPS, 2 mg/kg) to induce atherosclerotic change and were fed an atherogenic diet for 12 weeks. Apamin (0.05 mg/kg) was administered by ip injection. LPS-induced THP-1-derived macrophage inflammation treated with apamin reduced expression of tumor necrosis factor (TNF)-α, vascular cell adhesion molecule (VCAM)-1, and intracellular cell adhesion molecule (ICAM)-1, as well as the nuclear factor kappa B (NF-κB) signaling pathway. Apamin decreased the formation of atherosclerotic lesions as assessed by hematoxylin and elastic staining. Treatment with apamin reduced lipids, Ca2+ levels, and TNF-α in the serum from atherosclerotic mice. Further, apamin significantly attenuated expression of VCAM-1, ICAM-1, TGF-β1, and fibronectin in the descending aorta from atherosclerotic mice. These results indicate that apamin plays an important role in monocyte/macrophage inflammatory processing and may be of potential value for preventing atherosclerosis

    Adrenoleukodystrophy 1례

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    We describe a 9-year-old boy who showed typical neurologic manifestations i.e., progressive behavioral changes, intellectual impairment, visual disturbances and hearing loss, cerebellar and pyramidal signs with characteristic neuroimaging features, which led us to make a clinical deagnosis of ALD. It was confirmed later by demonstration of increased VLCFA levels in RBC membrane using HPLC. He has no family history of neurologic or endocrine disorder. Prophylactic antiepileptic medicaion could not prevent the development of seizure disorder

    Predictive value of progression-related gene classifier in primary non-muscle invasive bladder cancer

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    <p>Abstract</p> <p>Background</p> <p>While several molecular markers of bladder cancer prognosis have been identified, the limited value of current prognostic markers has created the need for new molecular indicators of bladder cancer outcomes. The aim of this study was to identify genetic signatures associated with disease prognosis in bladder cancer.</p> <p>Results</p> <p>We used 272 primary bladder cancer specimens for microarray analysis and real-time reverse transcriptase polymerase chain reaction (RT-PCR) analysis. Microarray gene expression analysis of randomly selected 165 primary bladder cancer specimens as an original cohort was carried out. Risk scores were applied to stratify prognosis-related gene classifiers. Prognosis-related gene classifiers were individually analyzed with tumor invasiveness (non-muscle invasive bladder cancer [NMIBC] and muscle invasive bladder cancer [MIBC]) and prognosis. We validated selected gene classifiers using RT-PCR in the original (165) and independent (107) cohorts. Ninety-seven genes related to disease progression among NMIBC patients were identified by microarray data analysis. Eight genes, a progression-related gene classifier in NMIBC, were selected for RT-PCR. The progression-related gene classifier in patients with NMIBC was closely correlated with progression in both original and independent cohorts. Furthermore, no patient with NMIBC in the good-prognosis signature group experienced cancer progression.</p> <p>Conclusions</p> <p>We identified progression-related gene classifier that has strong predictive value for determining disease outcome in NMIBC. This gene classifier could assist in selecting NMIBC patients who might benefit from more aggressive therapeutic intervention or surveillance.</p

    A Case of Intestinal Behcet's Disease Similar to Crohn's Colitis

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    Behcet's disease is a multi-systemic vasculitis and characterized by systemic organ involvement. Although the gastrointestinal and systemic features of Behcet's disease and inflammatory bowel disease overlap to a considerable extent, they are generally viewed as two distinct diseases. A 39-yr-old female was diagnosed as having Behcet's disease. She was admitted to our hospital because of oral and genital ulcer, lower abdominal pain, and frequent diarrhea. Colonosopy showed diffuse involvement of multiple longitudinal ulcers with inflammatory pseudopolyps with a cobblestone appearance and ano-rectal fistula was suspected. These findings are extremely rare in Behcet's disease. However, there were no granulomas, the hallmark of Crohn's colitis. Microscopically, perivasculitis and multiple lymph follicles compatible with Behcet's disease were seen. Although being rarely encountered, multiple longitudinal ulcers, cobblestone appearance, and ano-rectal fistula can develop in Behcet's disease, as in Crohn's colitis. Therefore, Behcet's disease and Crohn's disease may be closely related and part of a spectrum of disease

    Rapidly Progressive Cardiac Manifestation of Behçet's Disease Involving Conduction System and Aortic Valve

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    Cardiac conduction system impairment is a rare clinical manifestation of Behçet's disease. We report a patient who showed 1st degree atrioventricular block at first presentation, and showed aggravated finding of 3rd degree atrioventricular block on five months later. His cardiac manifestation finally developed to acute severe aortic regurgitation on six months later from his first cardiac manifestation. We observed this rapid progression during 6 months and successfully improved symptom and disease severity of the patient with treatment targeting Behçet's disease

    Chronic gastrointestinal symptoms and quality of life in the Korean population

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    AIM: To evaluate the prevalence of chronic gastrointestinal symptoms and their impact on health-related quality of life (HRQOL) in the Korean population
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