2,039 research outputs found
Tradeoff Analysis of Delay-Power-CSIT Quality of Dynamic BackPressure Algorithm for Energy Efficient OFDM Systems
In this paper, we analyze the fundamental power-delay tradeoff in
point-to-point OFDM systems under imperfect channel state information quality
and non-ideal circuit power. We consider the dynamic back- pressure (DBP)
algorithm, where the transmitter determines the rate and power control actions
based on the instantaneous channel state information (CSIT) and the queue state
information (QSI). We exploit a general fluid queue dynamics using a continuous
time dynamic equation. Using the sample-path approach and renewal theory, we
decompose the average delay in terms of multiple unfinished works along a
sample path, and derive an upper bound on the average delay under the DBP power
control, which is asymptotically accurate at small delay regime. We show that
despite imperfect CSIT quality and non-ideal circuit power, the average power
(P) of the DBP policy scales with delay (D) as P = O(Dexp(1/D)) at small delay
regime. While the impacts of CSIT quality and circuit power appears as the
coefficients of the scaling law, they may be significant in some operating
regimes.Comment: 30 page
Synthesis and Characterization of Drug-Loaded Poly( ε
We produced drug-loaded poly(ε-caprolactone) (PCL)/silica hybrid nanofibrous scaffolds with various silica sol contents (0 vol%, 10 vol%, 15 vol%, and 20 vol%) using electrospinning and examined their physicochemical properties, mechanical properties, drug release behavior, and in vitro biocompatibility to evaluate their potential application for guided bone regeneration (GBR). The loading efficiency of tetracycline hydrochloride (TCH) drug was remarkably enhanced by hybridizing the PCL solution with the silica sol. All produced hybrid scaffolds had a highly nanofibrous structure, in which the silica phase was homogeneously hybridized with the PCL polymer, while preserving their intrinsic characteristics. This led to considerable increases in hydrophilicity and mechanical properties (e.g., ultimate tensile strength and elastic modulus). In addition, the release rate and cumulative maximum amounts of the TCH from the hybrid scaffolds significantly increased with increasing the silica content, while all produced hybrid nanofibrous scaffolds showed good biocompatibility assessed by in vitro cell tests
Large-Scale Plasma Polymer Coating on Heat Exchanger Fins for Improving the Wettability
This research presents the results of the recently developed large-scale hydrophilic polymer coating by plasma polymerization, optimum plasma zone (OPZ) process. The excellent hydrophilicity of heat exchanger fin surface could give good effects to efficient drainage of condensate water as well as heat transfer performance. The hydrophilicity of layer treated by large-scale OPZ system is excellent irrespective of line speed from 0.6 m/min to 2.4 m/min. The good lateral uniformity of the hydrophilicity could be acquired in large scale OPZ treatment. The application of OPZ technique to the heat exchanger could enhance the efficiency of heat transfer, resulting from decrease of pressure drop. Due to long-term durability of hydrophilicity, the heat transfer performance improved by OPZ process cannot be deteriorated with operation cycle
Permanent Hydrophilic Surface Formation by Ion Assisted Reaction
Since totally wettable hydrophilic polymer surfaces from hydrophobic polymers (PMMA, PTFE, PET and PC) have been demonstrated for the first time at Materials Research Society meeting, 1995 Fall meeting, Boston, the application of ion assisted reaction (IAR), in which energetic ions (0.5~1.5 keV) are irradiated on materials with blowing reactive gases near the irradiating surfaces, has been extended to various polymer, ceramic and metal for creating permanent hydrophilic surfaces. The surface energy was measured by Youngs equation and the highest energy, Es, of 60~70 mN/m, which is similar to surface energy of water (Es of H2O : 72 mN/m) is obtained by controlling ion dose, energy, and amount of blown gas. The higher surface energy of materials possesses the more wettable surface, and relation between wettability and adhesion has been discussed. The remarkable result is the strong adhesion of inert nonattachable material such as Pt on the modified surface. The improvements of adhesions, wettability and surface energy are mainly due to polar force and hydrophilic functional groups such as C=O, (C=O)-O, C-O, etc. on the modified surface without surface damage by surface analyses. Advantages of the method are (1) high reproducibility, (2) simplicity, (3) changing ability of wettability degree, and (4) easy connection to conventional semiconductor process line. Improvements of efficiencies by changing heat transfer coefficients have been presented for the compact heat exchanger system
Development of a novel fermented pumpkin-based beverage inoculated with water kefir grains: a response surface methodology approach
Pumpkin (Cucurbita pepo) is well known for its
health and nutritional benefits and is recommended for
daily consumption. This is the first report on optimization
and development of fermented pumpkin-based water kefir
beverage. Optimum pumpkin puree and brown sugar concentrations
were found at 22.28 and 9.07% w/v, respectively,
were made into a pumpkin-based beverage and
fermented with water kefir grains for 24 h at 32 �C. The
optimized fermented pumpkin-based water kefir beverage
was found to be non-alcoholic, achieved good overall
acceptability and high Lactobacillus, acetic acid bacteria
and yeast cell viability of approximately 1012, 109
and
109 CFU mL-1, respectively. Overall, the optimized product
attained superb technological characteristics and has
the potential for industrial exploitation as a refreshing
water kefir drink
C1-Ten is a PTPase of nephrin, regulating podocyte hypertrophy through mTORC1 activation
Hypertrophy is a prominent feature of damaged podocytes in diabetic kidney disease (DKD). mTORC1 hyperactivation leads to podocyte hypertrophy, but the detailed mechanism of how mTORC1 activation occurs under pathological conditions is not completely known. Moreover, reduced nephrin tyrosine phosphorylation has been observed in podocytes under pathological conditions, but the molecular mechanism linking nephrin phosphorylation and pathology is unclear so far. In this study, we observed a significant increase in C1-Ten level in diabetic kidney and in high glucose-induced damaged podocytes. C1-Ten acts as a protein tyrosine phosphatase (PTPase) at the nephrin-PI3K binding site and renders PI3K for IRS-1, thereby activating mTORC1. Furthermore, C1-Ten causes podocyte hypertrophy and proteinuria by increasing mTORC1 activity in vitro and in vivo. These findings demonstrate the relationship between nephrin dephosphorylation and the mTORC1 pathway, mediated by C1-Ten PTPase activity. We suggest that C1-Ten contributes to the pathogenesis of DKD by inducing podocyte hypertrophy under high glucose conditions.111Ysciescopu
Colorectal cancer screening: Barriers to the faecal occult blood test (FOBT) and colonoscopy in Singapore
Introduction: This study aims to identify the barriers to adopting faecal occult blood test (FOBT) and colonoscopy as colorectal cancer (CRC) screening methods among the eligible target population of Singapore. Materials and methods: This study was previously part of a randomised controlled trial reported elsewhere. Data was collected from Singapore residents aged 50 and above, via a household sample survey. The study recruited subjects who were aware of CRC screening methods, and interviewed them about the barriers to screening that they faced. Collected results on barriers to each screening method were analysed separately. Results: Out of the 343 subjects, 85 (24.8%) recruited knew about FOBT and/or colonoscopy. Most of the respondents (48.9%) cited not having symptoms as the reason for not using the FOBT. This is followed by inconvenience (31.1%), not having any family history of colon cancer (28.9%), lack of time (28.9%) and lack of reminders/recommendation (28.9%). Of the respondents who indicated not choosing colonoscopy as a screening method, more than one-half (54.8%) identified not having any symptoms as the main barrier for them, followed by not having any family history (38.7%) and having a healthy/low-risk lifestyle (29.0%). There was no difference between the reported barriers to each of the screening methods and the respondents\u27 dwelling types. Conclusions: Lack of knowledge, particularly the misconceptions of not having symptoms and being healthy, were identified as the main barriers to FOBT and colonoscopy as screening methods. Interventions to increase the uptake of CRC screening in this population should be tailored to address this misconception
Safety Evaluation of Yukmijihwang-tang: Assessment of Acute and Subchronic Toxicity in Rats
Yukmijihwang-tang (YMJ; Liu wei di huang tang (China), Rokumigan (Japan)) has been used in the treatment of diseases including renal disorder, cognitive vitality, and diabetes mellitus. However, there is very little information regarding the toxicity of YMJ to give an assurance of safety for clinical treatment. To provide safety information for YMJ, we evaluated its acute and sub-chronic toxicity in rats. The single-dose toxicity of YMJ was examined using Sprague-Dawley rats. Rats were treated with YMJ extract orally at 0, 500, 1000, or 2000 mg/kg body weight. After a single administration, clinical signs were observed every day for two weeks, and body weights were measured five times, including an initial measurement on day 1 (the day of administration). In the sub-chronic oral toxicity study, YMJ was administered to rats at 0, 500, 1000, or 2000 mg/kg/day for 13 weeks. Mortalities, clinical signs, body weight changes, food and water consumption, ophthalmologic findings, urinalysis, hematological and biochemical parameters, gross findings, organ weights, and histological examination were monitored during the study period. We found no mortality and no abnormalities in clinical signs, body weights, and necropsy findings for any of the animals in the acute and sub-chronic studies following oral administration in the rat at up to 2000 mg/kg/day YMJ. YMJ may not have any single-dose toxicity; the LD50 of YMJ was over 2000 mg/kg, and it is safe for rats. The no-observed-adverse-effect-level (NOAEL) was considered to be 2000 mg/kg/day
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