759 research outputs found

    New Preamble Design for Reduced-Complexity Timing Acquisition in UWB Systems

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    Abstract-Low-complexity rapid timing acquisition is one of the most pivotal challenges in ultra-wideband (UWB) wireless technology whose short duration pulse results in high resolution in time. In this paper, we propose a new preamble which can reduce the performance degradation caused by diminishing the operational complexity of the coarse timing acquisition. In the reduced-complexity acquisition algorithm, the received preamble is shortened by summing its elements group-by-group and correlated with the known PN sequence having reduced length to find the maximum output value of the correlators. This acquisition algorithm introduces performance deterioration since it loses the impulsive autocorrelation property of the PN sequence after summation. Therefore, we judiciously design a new preamble sequence whose slide correlator output function shows a distinct peak at zero delay and the symmetry even after summation. Simulation results demonstrate that the reducedcomplexity acquisition algorithm exploiting the proposed preamble outperforms the algorithm using the PN sequence as the preamble, while the amount of computational reduction remains the same

    Translation and validation of the Korean confusion assessment method for the intensive care unit

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    <p>Abstract</p> <p>Background</p> <p>Delirium is a common problem and associated with poor outcomes in intensive care unit (ICU) patients. Diagnosis of delirium in ICU patients is limited and usually underdiagnosed by physicians. The Confusion Assessment Method for the Intensive Care Unit (CAM-ICU) is one of the most widely used screening methods for detection of ICU delirium. Our goal was to translate and validate the CAM-ICU for use in the Korean ICU setting.</p> <p>Methods</p> <p>Translation of the CAM-ICU was done according to the guidelines suggested by the Translation and Cultural Adaptation Group. For validation and interrater reliability assessment of the Korean CAM-ICU, two nurses independently assessed delirium in ICU patients and the results were compared with the reference evaluation, which was done by a psychiatrist using the Diagnostic and Statistical Manual of Mental Disorders IV (DSM-IV).</p> <p>Results</p> <p>Twenty-two patients were evaluated by two nurses and one psychiatrist expert independently. During the study period, we have continuously educated study nurses. Based on DSM-IV criteria, 16 out of 22 (72.7%) patients developed delirium. The sensitivities of the two nurses' evaluations using the Korean CAM-ICU were 89.80% for nurse 1 and 77.40% for nurse 2. Their specificities were 72.40% and 75.80% and their overall accuracy was 83.33% and 88.37% respectively. The Korean CAM-ICU was done with reasonable interrater reliability between nurse 1 and nurse 2 (κ = 0.81, <it>p </it>< 0.001).</p> <p>Conclusions</p> <p>The Korean CAM-ICU showed good validity and could be incorporated into clinical practice in Korean ICUs.</p> <p>Trial registration</p> <p>ISRCTN: <a href="http://www.controlled-trials.com/ISRCTN50265663">ISRCTN50265663</a></p

    Effects of Korean Red Ginseng (Panax ginseng), urushiol (Rhus vernicifera Stokes), and probiotics (Lactobacillus rhamnosus R0011 and Lactobacillus acidophilus R0052) on the gut–liver axis of alcoholic liver disease

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    AbstractBackgroundRoles of immune reaction and toll-like receptor-4 (TLR-4) have widely been established in the pathogenesis of alcoholic liver disease (ALD).MethodsWe evaluated the biologic efficacy of Korean Red Ginseng (KRG), urushiol, and probiotics (Lactobacillus rhamnosus R0011 and Lactobacillus acidophilus R0052) in mouse models of ALD. Sixty C57BL/6 mice were equally divided into six feeding groups for 10 weeks: normal diet, alcohol, control, alcohol + KRG, alcohol + urushiol, and alcohol + probiotics. Alcohol was administered via a Lieber–DeCarli liquid diet containing 10% alcohol. TLR-4 expression, proinflammatory cytokines, and histology, as well as the results of liver function tests were evaluated and compared.ResultsNo between-group differences were observed with regard to liver function. TLR-4 levels were significantly lower in the KRG, urushiol, and probiotics groups than in the alcohol group (0.37 ± 0.06 ng/mL, 0.39 ± 0.12 ng/mL, and 0.33 ± 0.07 ng/mL, respectively, vs. 0.88 ± 0.31 ng/mL; p < 0.05). Interleukin-1β levels in liver tissues were decreased among the probiotics and KRG groups. The tumor necrosis factor-α level of liver tissue was decreased in the KRG group.ConclusionThe pathological findings showed that alcohol-induced steatosis was significantly reduced by KRG and urushiol. As these agents improve immunologic capacity, they may be considered in potential anti-ALD treatments

    Compensatory proliferation of endogenous chicken primordial germ cells after elimination by busulfan treatment

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    This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.Introduction Primordial germ cells (PGCs) are the major population of cells in the developing bilateral embryonic gonads. Little is known about the cellular responses of PGCs after treatment with toxic chemicals such as busulfan during embryo development. In this study, we investigated the elimination, restorative ability, and cell cycle status of endogenous chicken PGCs after busulfan treatment. Methods Busulfan was emulsified in sesame oil by a dispersion-emulsifying system and injected into the chick blastoderm (embryonic stage X). Subsequently, we conducted flow cytometry analysis to evaluate changes in the PGC population and cell cycle status, and immunohistochemistry to examine the germ cell proliferation. Results Results of flow cytometry and immunohistochemistry analyses after busulfan treatment showed that the proportion of male PGCs at embryonic day 9 and female PGCs at embryonic day 7 were increased by approximately 60% when compared with embryonic day 5.5. This result suggests the existence of a compensatory mechanism in PGCs in response to the cytotoxic effects of busulfan. Results of cell cycling analysis showed that the germ cells in the G0/G1 phase were significantly decreased, while S/G2/M-phase germ cells were significantly increased in the treatment group compared with the untreated control group in both 9-day-old male and female embryos. In addition, in the proliferation analysis with 5-ethynyl-2′-deoxyuridine (EdU) incorporation, we found that the proportion of EdU-positive cells among VASA homolog-positive cells in the 9-day embryonic gonads of the busulfan-treated group was significantly higher than in the control group. Conclusions We conclude that PGCs enter a restoration pathway by promoting their cell cycle after experiencing a cytotoxic effect

    Enhancement of Gastric Ulcer Healing and Angiogenesis by Cochinchina Momordica Seed Extract in Rats

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    Cochinchina momordica seed is the dried ripe seed of Momordica cochinchinensis, a perennial vine. The antiulcer effect of an extract from cochinchina momordica seeds (SK-MS10) was evaluated in a rat model of acetic acid-induced gastric ulcers. Gastric ulcers were produced by subserosal injection of acetic acid. SK-MS10 (200 mg/kg) or vehicle was administered orally once per day for 14 days after the acetic acid injection. The stomach was removed and the ulcer size measured at day 7 and 14 of the treatment. Expression of vascular endothelial growth factor (VEGF) was assessed by real-time RT-PCR and Western blot analysis. In addition, the microvasculature density (MVD) adjacent to the ulcer margin was examined by immunohistochemistry. The treatment with SK-MS10 for 7 and 14 days significantly accelerated ulcer healing and increased the expression of mRNA (at day 7) as well as VEGF protein (at day 14) compared to the vehicle-treated rats. The MVD for factor VIII was also higher in the SK-MS10 treatment group compared to the vehicle-treated rats; however, these differences were not statistically significant. These results suggest that SK-MS10 treatment accelerates the healing of gastric ulcers via upregulation of VEGF and angiogenesis in an acetic acid rat model

    Characteristics of Type 2 Diabetes in Terms of Insulin Resistance in Korea

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    The aim of this study was to assess the implications of insulin resistance on the clinical and biochemical profiles of Korean type 2 diabetic patients. 122 patients with type 2 diabetes underwent a short insulin tolerance test to assess insulin resistance. Subjects were classified in tertiles according to ISI (insulin sensitivity index), and the tertile I (the insulin-resistant group) and tertile III (the insulin-sensitive group) clinical and biochemical parameters were compared. Age, waist circumference (WC), systolic blood pressure (SBP), HbA1c, body fat content, and fasting plasma glucose were significantly higher in tertile I than tertile III (all p < 0.05). The frequency of hypertension and family history of cerebrovascular disease (CVD) were greater in tertile I than III (p < 0.05). To evaluate the factors affecting ISI, multiple regression was performed, and age, WC, SBP, HbA1c, and body fat content were found to be independently related to insulin resistance (p < 0.05). Old age, hypertension, central obesity, and poor glycemic control were identified as clinical parameters of insulin resistance in Korean type 2 diabetic patients

    Highly sensitive near-infrared SERS nanoprobes for in vivo imaging using gold-assembled silica nanoparticles with controllable nanogaps

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    Abstract Background To take advantages, such as multiplex capacity, non-photobleaching property, and high sensitivity, of surface-enhanced Raman scattering (SERS)-based in vivo imaging, development of highly enhanced SERS nanoprobes in near-infrared (NIR) region is needed. A well-controlled morphology and biocompatibility are essential features of NIR SERS nanoprobes. Gold (Au)-assembled nanostructures with controllable nanogaps with highly enhanced SERS signals within multiple hotspots could be a breakthrough. Results Au-assembled silica (SiO2) nanoparticles (NPs) (SiO2@Au@Au NPs) as NIR SERS nanoprobes are synthesized using the seed-mediated growth method. SiO2@Au@Au NPs using six different sizes of Au NPs (SiO2@Au@Au50–SiO2@Au@Au500) were prepared by controlling the concentration of Au precursor in the growth step. The nanogaps between Au NPs on the SiO2 surface could be controlled from 4.16 to 0.98nm by adjusting the concentration of Au precursor (hence increasing Au NP sizes), which resulted in the formation of effective SERS hotspots. SiO2@Au@Au500 NPs with a 0.98-nm gap showed a high SERS enhancement factor of approximately 3.8 × 106 under 785-nm photoexcitation. SiO2@Au@Au500 nanoprobes showed detectable in vivo SERS signals at a concentration of 16μg/mL in animal tissue specimen at a depth of 7mm. SiO2@Au@Au500 NPs with 14 different Raman label compounds exhibited distinct SERS signals upon subcutaneous injection into nude mice. Conclusions SiO2@Au@Au NPs showed high potential for in vivo applications as multiplex nanoprobes with high SERS sensitivity in the NIR region. Graphical Abstrac
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