• Title/Summary/Keyword: Controlled models

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Obesity and Risk of Bladder Cancer: A Meta-analysis of Cohort Studies

  • Qin, Qi;Xu, Xin;Wang, Xiao;Zheng, Xiang-Yi
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.5
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    • pp.3117-3121
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    • 2013
  • Objective: Previous epidemiologic studies demonstrated that obesity might associated with the risk of bladder cancer. However, many of the actual association findings remained conflicting. To better clarify and provide a comprehensive summary of the correlation between obesity and bladder cancer risk, we conducted a meta-analysis to summarize results of studies on the issue. Stratified analyses were also performed on potential variables and characteristics. Methods: Studies were identified by searching in PubMed and Wanfang databases, covering all the papers published from their inception to March 10, 2013. Summary relative risks (SRRs) with their corresponding 95% confidence intervals (CIs) were calculated by either random-effect or fixed-effect models. Results: A total of 11 cohort studies were included in our meta-analysis, which showed that obesity was associated with an increased risk for bladder cancer in all subjects (RR=1.10, 95% CI=1.06-1.16; p=0.215 for heterogeneity; $I^2$=24.0%). Among the 9 studies that controlled for cigarette smoking, the pooled RR was 1.09 (95% CI 1.01-1.17; p=0.131 for heterogeneity; $I^2$=35.9%). No significant publication bias was detected (p = 0.244 for Egger's regression asymmetry test). Conclusions: Our results support the conclusion that obesity is associated with the increased risk of bladder cancer. Further research is needed to generate a better understanding of the correlation and to provide more convincing evidence for clinical intervention in the prevention of bladder cancer.

Characteristics Analysis of Class E Frequency Multiplier using FET Switch Model (FET 스위치 모델을 이용한 E급 주파수 체배기 특성 해석)

  • Joo, Jae-Hyun;Koo, Kyung-Heon
    • Journal of Advanced Navigation Technology
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    • v.15 no.4
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    • pp.596-601
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    • 2011
  • This paper has presented research results for the switching mode class E frequency multiplier that has simple circuit structure and high efficiency. Frequency multiplication is coming from the nonlinearity of the active component, and this paper models the FET active component as a simple switch and some parasitics to analyze the characteristics. The matching component parameters for the class E frequency doubler have been derived with modeling the FET as a input controlled switch and some parasitics. A circuit simulator, ADS, is used to simulate the output voltage and current waveform and efficiency with the variation of the parasitic values. With 2.9GHz input and 2V bias, the drain efficiency has been decreased from 98% to 28% with changing the parasitic capacitance from 0pF to 1pF at 5.8GHz output, which shows that the parasitic capacitance CP has the most significant effect on the efficiency among the parasitics of FET.

Short-term protein intake increases fractional synthesis rate of muscle protein in the elderly: meta-analysis

  • Gweon, Hyun-Soo;Sung, Hee-Ja;Lee, Dae-Hee
    • Nutrition Research and Practice
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    • v.4 no.5
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    • pp.375-382
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    • 2010
  • The precise effects of protein intake on fractional synthesis rate (FSR) of muscle protein are still under debate. The sample size of these studies was small and the conclusions in young and elderly subjects were inconsistent. To assess the effect of dietary protein intake on the FSR level, we conducted a meta-analysis of controlled protein intake trials. Random-effects models were used to calculate the weighted mean differences (WMDs). Ten studies were included and effects of short-term protein intake were evaluated. In an overall pooled estimate, protein intake significantly increased the FSR (20 trials, 368 participants; WMD: 0.025%/h; 95%CI: 0.019-0.031; P < 0.0001). Meta-regression analysis suggested that the protein dose was positively related to the effect size (regression coefficient = 0.108%/h; 95%CI: 0.035, 0.182; P = 0.009). A subgroup analysis indicated that protein intake significantly increased FSR when the protein dose was ${\leq}$ 0.80 g/kg BW (16 trials, 308 participants; WMD: 0.027%/h; 95%CI: 0.019-0.031; P < 0.0001), but did not affect FSR when the protein dose was > 0.80 g/kg BW (4 trials, 60 participants; WMD: 0.016%/h; 95%CI: 0.004-0.029; P = 0.98). In conclusion, this study is the first integrated results showing that a short-term protein intake is effective at improving the FSR of muscle protein in the healthy elderly as well as young subjects. This beneficial effect seems to be dose-dependent when the dose levels of protein range from 0.08 to 0.80 g/kg BW.

Mandibular changes during initial alignment with SmartClip self-ligating and conventional brackets: A single-center prospective randomized controlled clinical trial

  • Celikoglu, Mevlut;Bayram, Mehmet;Nur, Metin;Kilkis, Dogan
    • The korean journal of orthodontics
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    • v.45 no.2
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    • pp.89-94
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    • 2015
  • Objective: To test the null hypothesis that SmartClip self-ligating brackets are more effective than conventional brackets for initial mandibular alignment and identify influential factors. Methods: Fifty patients were randomly allocated to two equal treatment groups by using an online randomization program: self-ligating group (SmartClip brackets) and conventional group (Gemini brackets). The archwire sequence was standardized. Changes in anterior irregularity index, intercanine width, and intermolar width were assessed on plaster models at 8th and 16th weeks. Changes in incisor position and inclination were assessed on lateral cephalometric radiographs at 16 weeks. Intragroup and intergroup comparisons were performed with paired t-test and Student's t-test, respectively. Multiple linear regression was performed to identify variables affecting improvement in anterior ambiguity. Results: Data of 46 patients were analyzed; those missing an appointment (n = 2) or showing bracket breakage (n = 2) were excluded. Incisor inclination (p < 0.05), intercanine width (p < 0.05), and intermolar width (p > 0.05) increased at 8 and 16 weeks in both the groups; no significant intergroup differences were noted (p > 0.05). Initial anterior irregularity index and intercanine width change were significantly associated with improvement in anterior irregularity (p < 0.001). Conclusions: The null hypothesis was rejected. Bracket type has little effect on improvement in anterior ambiguity during initial mandibular alignment.

Development of Integrated System for Virtual Design and Performance Testing of Automobile Seat (자동차 시트 가상설계와 성능평가를 위한 통합시스템 개발)

  • Im, O-Gang;Yu, Wan-Seok;Jeong, Yung-Ho;Kim, Gwang-Seok;Lee, Jin-Sik;No, Hyo-Cheol
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.24 no.7 s.178
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    • pp.1779-1786
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    • 2000
  • Most of traditional design processes of mechanical parts are regarded as sequential and discrete, since different kinds of softwas should be introduced. In this paper, we develop an integrated fram ework for virtual design and performance testing of an automobile seat. The system is composed of four modules, i.e. CAD, static analysis, dynamic analysis, and draft drawing module. In the CAD module, PRO/ENGINEER 3D seat model is created using parameters to be modified with the result of static and dynamic analysis. In the static analysis, headrest tere used in each design stage make it difficult to feedback their results to upstream process. These discrete processes may result in time loss and cost rise. In recent years, life cycle of product is reduced. To have competence with others, new concept design processt is simulated using ANSYS. In the dynamic analysis module, FMVSS201 test is simulated using DADS. Overall data flow is controlled by Motif. The advantage of the system is that even a novice can perform and review the whole design process, without a good hand at professional design/analysis S/W in each stage. The system also provides a virtual design space, where engineers in different development stage can access common data of design models. The concept could be applied to other fields and it could reduce time and money required in design process.

Crystallization Mechanism of Lithium Dislicate Glass with Various Particle Sizes (Lithium disilicate 유리의 입자크기에 따른 결정화 기구)

  • Choi, Hyun Woo;Yoon, Hae Won;Yang, Yong Suk;Yoon, Su Jong
    • Korean Journal of Materials Research
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    • v.26 no.1
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    • pp.54-60
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    • 2016
  • We have investigated the crystallization mechanism of the lithium disilicate ($Li_2O-2SiO_2$, LSO) glass particles with different sizes by isothermal and non-isothermal processes. The LSO glass was fabricated by rapid quenching of melt. X-ray diffraction and differential scanning calorimetry measurements were performed. Different crystallization models of Johnson-Mehl-Avrami, modified Ozawa and Arrhenius were adopted to analyze the thermal measurements. The activation energy E and the Avrami exponent n, which describe a crystallization mechanism, were obtained for three different glass particle sizes. Values of E and n for the glass particle with size under $45{\mu}m$, $75{\sim}106{\mu}m$, and $125{\sim}150{\mu}m$, were 2.28 eV, 2.21 eV, 2.19 eV, and ~1.5 for the isothermal process, respectively. Those values for the non-isothermal process were 2.4 eV, 2.3 eV, 2.2 eV, and ~1.3, for the isothermal process, respectively. The obtained values of the crystallization parameters indicate that the crystallization occurs through the decreasing nucleation rate with a diffusion controlled growth, irrespective to the particle sizes. It is also concluded that the smaller glass particles require the higher heat absorption to be crystallized.

Effect of cold stress on infanticide by female Swiss albino mice Mus musculus: a pilot study

  • Zafar, Tabassum;Naik, Ab Qayoom;Shrivastava, Vinoy K.
    • Journal of Animal Science and Technology
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    • v.60 no.4
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    • pp.7.1-7.5
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    • 2018
  • Background: Mice are widely accepted research models of great clinical significance. Maintenance of laboratory mice breed is an essential aspect for performing research activities in various fields of science. Infanticide is one of the prominent causes of litter loss during maintenance of laboratory mice stock. The present study is an effort to monitor the effect of change in ambient temperature of female mice below the normal range on cannibalism and infanticide during early postparturition phase. Adult female Swiss albino mice have been divided into two groups of control and treatment. On the day of litter group one was maintained under controlled temperature conditions (minimum $20^{\circ}C$ to maximum $23^{\circ}C$) throughout, while female mice belong to group two have been exposed to variation of room temperature (maximum $15^{\circ}C$ to minimum $10^{\circ}C$ for two nights and one day) until 36 h postparturition. Results: The effects of temperature changes were observed on the infanticide behaviour of dams along with the survival of pups in early postparturition phase till 36 h after delivery. The significant statistical difference (P < 0.05) was reported in infanticide behaviour of dams when control and treatment group was compared. It is observed that decrement in surrounding temperature promotes decrement in the ambient body temperature of dams during early postparturition. It is proposed that alteration of hypothalamic homeostasis due to temperature change induces cannibalism and infanticide behaviour. Lack of thermoregulation during early postparturition creates the sense of insecurity, in-satiety, anxiety and stress. Conclusions: Authors strongly recommend the maintenance of body and surrounding temperature to prevent infanticidal behaviour and cannibalism within Swiss albino mice population. Further investigations are advisable to authenticate the active behavioural and biochemical pathway behind the phenomena.

The Effect of Vocational Training on Employment Outcome in Korea's Training Credit Program (내일배움카드제 훈련이 취업성과에 미치는 영향)

  • Kim, Yong-seong
    • Journal of Labour Economics
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    • v.43 no.1
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    • pp.1-34
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    • 2020
  • As the economic environment rapidly changes, the ability to flexibly adapt has become a vital skill which is primarily attained through education and training. Subsequently, it is essential that the effects of vocational eduction and training are closely examined to see if they are fulfilling their goals; specifically, whether they bolster the chances of gaining employment. To that end, the endogenous aspects of training variables must be controlled. This study critically assesses the approaches of current literature in regards to tackling the endogeneity issue, and investigates the effects of vocational training through various econometric models. The results failed to reveal any positive effects of Korea's vocational training on employment. However, the negative effects were also not large enough to be significant. Additionally, the marginal effects were weaker for women and older age groups-which show a disparity between men and women-than for men and younger age groups, respectively. A more comprehensive and in-depth analysis will be needed of these results using recent data and detailed information about the training process.

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Measurement of Gravity Center for Rotor Blades by Compensation of Machining Error in Jig (지그의 가공오차 보정에 의한 블레이드 무게 중심 측정)

  • Kong, Jae-Hyun;Kim, Ki-Sung;Ye, Sang-Don;Chun, See-Young;Hur, Kwan-Do
    • Journal of the Korean Society for Precision Engineering
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    • v.27 no.12
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    • pp.41-47
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    • 2010
  • There are many unbalanced models such as helicopter's rotor blades, small-sized precision motor in industrial applications. In the real products, their gravity center usually does not accord with the desired gravity center. If the deviation is large between them, it can be a major cause of vibration and noise as the part of model rotate. Therefore the gravity center in the rotational parts should be controlled properly because of static and dynamic balancing of the parts. In the research, the rotor blade of unmanned helicopter has been selected to obtain the high quality of balancing. In order to achieve the purpose, measuring system has been developed. In the system applied principle is three point weighting method, which is one of the Multiple-point Weighting Method. It has circle fitting for compensation of machining error, after measuring the values. From this study, the results showed that the proposed measurement procedure gives reliable and precise gravity center.

Synergic Effect of Trimebutine Combined with Mosapride on Gastrointestinal Dysfunction and Visceral Pain Induced in Stress Models

  • Park, Young-Joon;Park, Yong-Sul;Chung, Zoo-Chul;Nam, Yun-Sung;Chung, Yoon-Hee;Cho, Kwan-Hyung;Choi, Sung-Up;Sohn, Uy-Dong;Park, Eon-Sub;Je, Hyun-Dong;Lee, Choong-Ho;Lee, Moo-Yeol;Jeong, Ji-Hoon
    • Biomolecules & Therapeutics
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    • v.19 no.1
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    • pp.84-89
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    • 2011
  • The present study was undertaken to determine whether combined treatment with prokinetic trimebutine and mosapride has a synergic effect on gastrointestinal motility and visceral pain associated with gastrointestinal dysfunction. To develop effective gastroprokinetic agents with greater potencies than trimebutine or mosapride for the treatment of gastrointestinal tract disease, a mixture of trimebutine and mosapride was designed and prepared. In the present study, treatment with trimebutine alone showed a dose-dependent effect on propelling movements of normal small and large intestine in mice, whereas mosapride effected only small intestine motility. Co-administration of trimebutine with mosapride, a well-established prokinetic drug, produced a synergistic influence on normal small intestine motility, but demonstrated an unclear effect on large intestine motility, with a slight tendency to reduce the propelling time. In a stress model, the small and large intestine motilities were significantly decreased. The reduction of intestine motility was restored to a normal level and the restoring effect was more pronounced in the combined treatment with trimebutine plus mosapride than treatment with trimebutine or mosapride alone. Furthermore, treatment with trimebutine plus mosapride significantly decreased acute visceral pain which was not controlled by trimebutine or mosapride alone. These data suggest that combination therapy with trimebutine plus mosapride has a synergic effect on small and large intestine motility and visceral pain control in gastrointestinal disorders.