• Title/Summary/Keyword: case control studies

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Planning Guidance for Snow Control Material Storage Facilities Based on Case Studies (사례조사를 통한 제설전진기지 시설기준에 관한 연구)

  • Kim, Geun-Young;Kim, Hee-Jea;Park, U-Yeol
    • Journal of the Korea Institute of Building Construction
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    • v.16 no.4
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    • pp.381-388
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    • 2016
  • The snow control storage facilities have the physical requirements that are an anti-icing and deicing operations. They are efficiently and quickly performed, and composed of a vehicle depot for the snow removal equipment and truck, anti-icing and deicing chemical storages, and the control utilities. This study is to investigate the planning guidance of foreign countries, and the actual conditions of the snow control chemical storage facilities for expressway, the national highway and the local road, and is to suggest the planning guidelines. As some of the authorities have no fixed structures for the snow control storage, this study analyze the 5 cases constructed lately. From the result of the case studies, the operations performed in the snow control storage facilities and drawback of the facilities are analyzed with respect to layout, size, plan, and structure, and the improvement planning guidance is also suggested.

Wound Healing Activity of the Chloroform Extract of Plumbago rosea Linn. and Plumbagin

  • Saraswathy, A.;Chandran, R.V. Pradeep;Manohar, B. Murali;Vairamuthu, S.
    • Natural Product Sciences
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    • v.12 no.1
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    • pp.50-54
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    • 2006
  • The wound healing activity of plumbagin and the chloroform extract of Plumbago rosea Linn. (Yoot), incorporated into ointments with yellow soft paraffin, have been investigated on rats. Wound healing activity was studied using excision and incision wound models in rats following topical application. Both plumbagin and the Plumbago rosea root extract produced a significant response in both of the wound models studied. The wound contracted in 14 days in the case of plumbagin (0.1%) and 16 days in case of Plumbago rosea root extract (0.5%), as against in 22 days in the case of control animals. The results were also comparable to those of a standard drug, framycetin sulphate cream (1% w/w) in terms of wound contracting ability, wound closure time, tensile strength of wound and regeneration of tissues at the wound site. Histological studies revealed evidences for the healing process by formation of fibrovascular tissue, epithelization and increased collagenization when compared to control.

A Study on the Impact Analysis of Security Flaws between Security Controls: An Empirical Analysis of K-ISMS using Case-Control Study

  • Kim, Hwankuk;Lee, Kyungho;Lim, Jongin
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.11 no.9
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    • pp.4588-4608
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    • 2017
  • The measurement of information security levels is a very important but difficult task. So far, various measurement methods have studied the development of new indices. Note, however, that researches have focused on the problem of attaining a certain level but largely neglecting research focused on the issue of how different types of possible flaws in security controls affect each other and which flaws are more critical because of these effects. Furthermore, applying the same weight across the board to these flaws has made it difficult to identify the relative importance. In this paper, the interrelationships among security flaws that occurred in the security controls of K-ISMS were analyzed, and the relative impact of each security control was measured. Additionally, a case-control study was applied using empirical data to eliminate subjective bias as a shortcoming of expert surveys and comparative studies. The security controls were divided into 2 groups depending on whether or not a security flaw occurs. The experimental results show the impact relationship and the severity among security flaws. We expect these results to be applied as good reference indices when making decisions on the removal of security flaws in an enterprise.

A Case-Control Study on the Relationship between Obesity and Female Colorectal Cancer (여성 대장암 발생과 비만의 관련성에 관한 환자-대조군 연구)

  • Shin, Ae-Sun;Yoon, Ha-Chung;Yoo, Keun-Young
    • Journal of Preventive Medicine and Public Health
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    • v.35 no.2
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    • pp.147-152
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    • 2002
  • Objectives : A hospital-based case-control study was conducted to evaluate the role of obesity in the development of colorectal cancer. Methods : Three hundred and twenty four histologically confirmed female colorectal cancer cases and 26,998 non-cancer controls were selected from patients invited to the Aichi Cancer Center, Nagoya, Japan between 1989 and 1995. Information concerning demographic factors, medical history, family medical history, reproductive factors and dietary factors were obtained from self-administered questionnaires and medical records. The effects of weight and body mass index to colorectal cancer were examined using multiple logistic regression to control for other risk factors. Results : There was no significant association between female colorectal cancer and obesity. Heavier weight adjusted for height or body mass index did not increase the risk of colorectal cancer. Conclusions : These results suggest that there is no association between colorectal cancer risk and obesity in women.

Vibration isolation with smart fluid dampers: a benchmarking study

  • Batterbee, D.C.;Sims, N.D.
    • Smart Structures and Systems
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    • v.1 no.3
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    • pp.235-256
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    • 2005
  • The non-linear behaviour of electrorheological (ER) and magnetorheological (MR) dampers makes it difficult to design effective control strategies, and as a consequence a wide range of control systems have been proposed in the literature. These previous studies have not always compared the performance to equivalent passive systems, alternative control designs, or idealised active systems. As a result it is often impossible to compare the performance of different smart damper control strategies. This article provides some insight into the relative performance of two MR damper control strategies: on/off control and feedback linearisation. The performance of both strategies is benchmarked against ideal passive, semi-active and fully active damping. The study relies upon a previously developed model of an MR damper, which in this work is validated experimentally under closed-loop conditions with a broadband mechanical excitation. Two vibration isolation case studies are investigated: a single-degree-of-freedom mass-isolator, and a two-degree-of-freedom system that represents a vehicle suspension system. In both cases, a variety of broadband mechanical excitations are used and the results analysed in the frequency domain. It is shown that although on/off control is more straightforward to implement, its performance is worse than the feedback linearisation strategy, and can be extremely sensitive to the excitation conditions.

Meta-analysis of Association Studies of CYP1A1 Genetic Polymorphisms with Digestive Tract Cancers Susceptibility in Chinese

  • Liu, Chang;Jiang, Zheng;Deng, Qian-xi;Zhao, Ya-nan
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.11
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    • pp.4689-4695
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    • 2014
  • Background: A great number of studies have shown that cytochrome P450 1A1 (CYP1A1) genetic polymorphisms, CYP1A1 Msp I and CYP1A1 Ile/Val, might be risk factors for digestive tract cancers, including esophageal cancer (EC), gastric cancer (GC), hepatic carcinoma (HC), as well as colorectal cancer (CC), but the results are controversial. In this study, a meta-analysis of this literature aimed to clarify associations of CYP1A1 genetic polymorphisms with digestive tract cancers susceptibility in Chinese populations. Materials and Methods: Eligible case-control studies published until December 2013 were retrieved by systematic literature searches from PubMed, Embase, CBM, CNKI and other Chinese databases by two investigators independently. The associated literature was acquired through deliberate search and selection based on established inclusion criteria. Fixed-effects or random-effects models were used to estimate odds ratios (ORs and 95%CIs). The meta-analysis was conducted using Review Manager 5.2 and Stata 12.0 softwares with stability evaluated by both stratified and sensitivity analyses. Moreover, sensitivity analysis and publication bias diagnostics confirmed the reliability and stability. Results: Eighteen case-control studies with 1,747 cases and 2,923 controls were selected for CYP1A1 MspI polymorphisms, and twenty case-control studies with 3, 790 cases and 4, 907 controls for the CYP1A1 Ile/Val polymorphisms. Correlation associations between CYP1A1 Ile/Val polymorphisms and digestive tract cancers susceptibility were observed in four genetic models in the meta-analysis (GG vs AA:OR= 2.03, 95%CI =1.52- 2.72; AG vs AA: OR=1.26, 95%CI =1.07-1.48; [GG+AG vs AA] :OR =1.42, 95%CI=1.20-1.68, [GG vs AA+AG]:OR=1.80, 95%CI =1.40-2.31). There was no association between CYP1A1 Msp I polymorphisms and digestive tract cancers risk. Subgroup analysis for tumor type showed a significant association of CYP1A1 Ile/Val genetic polymorphisms with EC in China. However, available data collected by the study failed to reveal remarkable associations of GC or HC with CYP1A1 Ile/Val genetic polymorphisms and EC, GC or CC with CYP1A1 MspI genetic polymorphisms. Conclusions: Our results indicated that CYP1A1 Ile/Val genetic polymorphisms, but not CYP1A1 Msp I polymorphisms, are associated with an increased digestive tract cancers risk in Chinese populations. Additional well-designed studies, with larger sample size, focusing on different ethnicities and cancer types are now warranted to validate this finding.

Association between the HSPA1B ±1267A/G Polymorphism and Cancer Risk: a Meta-analysis of 14 Case-Control Studies

  • Kuang, Dan;Chen, Wei;Song, Yue-Zhang;Yu, Yan-Yan;Zhang, Dong-Ying;Wu, Lang;Tang, Jie
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.16
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    • pp.6855-6861
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    • 2014
  • Background: Previous epidemiological studies have suggested a potential role of the $HSPA1B{\pm}1267A/G$ polymorphism in risk of developing cancer. However, the results were inconsistent. Therefore, we performed this meta-analysis to summarize the possible association with cancer risk. Materials and Methods: We retrieved relevant articles from PubMed, EMBASE, ISI Web of Science, Chinese Biomedical Literature and Chinese National Knowledge Infrastructure. Studies were selected using specific criteria. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to assess those associations. All analyses were performed using STATA software. Results: Fourteen case-control studies, including 1, 834 cancer cases and 2, 028 controls were included in this meta-analysis. Overall, the results indicated that the G allele of HSPA1B gene ${\pm}1267A/G$ was significantly associated with an increased cancer risk in all genetic models (G vs A: OR=1.51, 95%CI 1.17-1.95, p=0.001; GG vs AA: OR=2.93, 95%CI 1.50-5.74, p=0.002; AG vs AA: OR=1.48, 95%CI 1.10-1.98, p=0.009; GG/AG vs AA: OR=1.69, 95%CI 1.22-2.33, p=0.001; GG vs AG/AA: OR=2.31, 95%CI 1.24-4.32, p=0.009). In the subgroup analysis stratified by ethnicity, a significant association was identified in Caucasians (G vs A: OR=1.35, 95%CI 1.08-1.69, p=0.008; GG/AG vs AA: OR=1.36, 95%CI 1.09-1.70, p=0.007), but not in Asians. In the stratified analysis by cancer types, individuals with the G allele showed an increased risk of hepatocellular carcinoma compared with carriers of the A allele (OR=2.40, 95%CI 1.47-3.91, p<0.001). Inversely, individuals with the GG genotype showed a decreased risk of gastric cancer compared with carriers of the AG/GG genotypes (GG vs AG/AA: OR=0.39, 95%CI 0.20-0.70, p=0.007). Conclusions: This meta-analysis suggests associations between the HSPA1B ${\pm}1267A/G$ polymorphism and risk of cancer. However, this association might be Caucasian-specific and the G allele of this polymorphism probably increases risk of hepatocellular carcinoma while decreasing risk of gastric cancer. Further well-designed studies based on larger sample sizes are needed to validate these findings.

Analysis of Safety Assessment Methodology for Railway Signaling Systems

  • Hwang, Jong-Gyu;Jo, Hyun-Jeong;Yoon, Yong-Ki
    • International Journal of Safety
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    • v.6 no.2
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    • pp.38-42
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    • 2007
  • As railway signaling system is computerized, the significance on safety demonstration and assessment has been increased. Therefore, railway signaling system should reflect the needs for safety assessment technique. Various studies on safety assessment technique for railway signaling have been made in Europe and standardization of the requirements for safety acceptance has been initiated by IEC. In order to develop and establish the safety assessment techniques for railway signaling in Korea, we try to review safety assessment activities for signaling system via reviewing relevant case studies and consulting with experts. And also we propose the safety assessment activity/methodology for Korean railway signaling system.

A Review of Recent Clinical Studies of Transcutaneous Electrical Nerve Stimulation (TENS) on Xerostomia - PubMed and Domestic Studies (구강건조증에 대한 경피적전기신경자극(Transcutaneous electrical nerve stimulation)의 최근 임상연구 동향 고찰 - Pubmed와 국내 논문을 중심으로)

  • Lee, Eunkyung;Jun, Hyejin;Kim, Minjeong;Park, Jae-Woo;Ko, Seok-Jae
    • The Journal of Internal Korean Medicine
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    • v.43 no.3
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    • pp.375-386
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    • 2022
  • Objectives: The purpose of this study was to summarize current clinical study trends and results regarding transcutaneous electrical nerve stimulation (TENS) treatment for xerostomia. Methods: Studies published from 2017 to 2022 were searched on domestic databases and PubMed. The included studies were analyzed according to the year, language, study design, diagnosis xerostomia method, and TENS treatment method. Results: Nine studies were included. There were three randomized controlled trials (RCTs), three case series, one case report, one case-control study, and one cross-sectional study. Conventional TENS was used in seven studies, and acupuncture-like TENS (ALTENS) was used in one study. The most common TENS attachment site was externally on the skin overlying the parotid gland region, and the setting of TENS was 50 Hz-250 μs the most. In all nine studies, TENS was effective for xerostomia as assessed by salivary flow rate or quality of life questionnaire. Additionally, no persistent adverse events were reported after TENS treatment. Conclusions: TENS treatment for xerostomia can be considered effective and safe, so it can be used in clinical practice.

A Review of Recent Clinical Studies of Acupuncture Treatment for Hiccups - PubMed and Domestic Studies (딸꾹질에 대한 침 치료의 최근 임상 연구 동향 고찰 - Pubmed와 국내 논문을 중심으로 -)

  • Kim, Minjeong;Park, Chaehyun;Jun, Hyejin;Park, Jae-Woo;Ko, Seok-Jae
    • The Journal of Internal Korean Medicine
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    • v.43 no.4
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    • pp.567-581
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    • 2022
  • Objectives: The purpose of this study was to summarize current clinical study trends and results regarding acupuncture treatments for hiccups. Methods: Studies published from 2012 to 2022 were searched on PubMed and domestic databases (OASIS, scienceON, RISS, KISS, KCI) using the keywords "hiccup*", "singultus", "singultation", "hiccupping", "intractable hiccup*", "acupuncture", "auricular acupuncture", "scalp acupuncture", "acupuncture point", "acupoint", "needle", "dry needle", "딸꾹질", and "침." The studies were analyzed according to the year, language, study design, characteristics of patients, and acupuncture intervention. Results: In total, 12 studies were selected: 8 case series, 2 case-control studies, and 2 case reports. Manual acupuncture was administered with more than 15 minutes of retention time, most frequently using ST36 and CV12. The acupuncture treatment was effective for hiccup symptoms in all studies, as assessed by clinical symptoms, such as duration time, number of episodes, and recurrence. Conclusions: Acupuncture treatment can be an effective and safe method for treating hiccups and can be used in clinical practice.