• 제목/요약/키워드: meta-synthesis

검색결과 112건 처리시간 0.028초

N-치환-5-chloro-1,3-dimethylpyrazole-4-carboxamide의 합성과 살균력 (Synthesis and antifungal activity of N-substituted-5-chloro-1,3-dimethylpyra-zole-4-carboxamide)

  • 김용환;전원배;박창규
    • Applied Biological Chemistry
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    • 제35권2호
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    • pp.87-91
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    • 1992
  • 생리활성을 갖는 신규물질탐색의 일환으로 26종의 N-치환-5-chloro-1,3-dimethylpyra-zole-4-carboxamide 화합물을 합성하고, 이들 구조를 $^1H-NMR$로 확인하였다. 이들 유도체들을 Rhizoctonia solani, Botrytis cinerea, Pyricularia oryzae 및 Colletotricum gleosporiodes에 대한 in vitro에서의 균사생육억제효과를 검정한 결과 electron releasing group으로 meta 치환된 aniline의 carboxamide가 R. solani에 대해 12.5 ppm 수준에서 70% 이상의 살균효과를 보여주었다.

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Evaluation of the MTHFR C677T Polymorphism as a Risk Factor for Colorectal Cancer in Asian Populations

  • Rai, Vandana
    • Asian Pacific Journal of Cancer Prevention
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    • 제16권18호
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    • pp.8093-8100
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    • 2016
  • Background: Genetic and environmental factors play important roles in pathogenesis of digestive tract cancers like those in the esophagus, stomach and colorectum. Folate deficiency and methylenetetrahydrofolate reductase (MTHFR) as an important enzyme of folate and methionine metabolism are considered crucial for DNA synthesis and methylation. MTHFR variants may cause genomic hypomethylation, which may lead to the development of cancer, and MTHFR gene polymorphisms (especially C677T and A1298C) are known to influence predispositions for cancer development. Several case control association studies of MTHFR C677T polymorphisms and colorectal cancer (CRC) have been reported in different populations with contrasting results, possibly reflecting inadequate statistical power. Aim: The present meta-analysis was conducted to investigate the association between the C677T polymorphism and the risk of colorectal cancer. Materials and Methods: A literature search of the PubMed, Google Scholar, Springer link and Elsevier databases was carried out for potential relevant articles. Pooled odds ratio (OR) with corresponding 95 % confidence interval (95 % CI) was calculated to assess the association of MTHFR C677T with the susceptibility to CRC. Cochran's Q statistic and the inconsistency index (I2) were used to check study heterogeneity. Egger's test and funnel plots were applied to assess publication bias. All statistical analyses were conducted by with MetaAnalyst and MIX version 1.7. Results: Thirty four case-control studies involving a total of 9,143 cases and 11,357 controls were retrieved according to the inclusion criteria. Overall, no significant association was found between the MTHFR C677T polymorphism and colorectal cancer in Asian populations (for T vs. C: OR=1.03; 95% CI= 0.92-1.5; p= 0.64; for TT vs CC: OR=0.88; 95%CI= 0.74-1.04; p= 0.04; for CT vs. CC: OR = 1.02; 95%CI= 0.93-1.12; p=0.59; for TT+ CT vs. CC: OR=1.07; 95%CI= 0.94-1.22; p=0.87). Conclusions: Evidence from the current meta-analysis indicated that the C677T polymorphism is not associated with CRC risk in Asian populations. Further investigations are needed to offer better insight into any role of this polymorphism in colorectal carcinogenesis.

귀비탕과 그 변방의 만성피로증후군 증상완화에 대한 효용성: 체계적인 문헌고찰 (Is Gwibitang and its modification beneficial for alleviating symptoms in chronic fatigue syndrome: A systematic review and meta-analysis)

  • 남동현
    • 대한한의학방제학회지
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    • 제28권2호
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    • pp.199-209
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    • 2020
  • Objectives : The purpose of this systematic review is to confirm whether Gwibitang is beneficial in chronic fatigue syndrome (CFS). Methods : Clinical trials were searched from databases including Pubmed, Embase, Central Cochrane, CNKI, Wanfang, CQVIP, CiNii, OASIS, Koreamed, and NDSL. The eligible study design was limited into randomized controlled trial, quasi-randomized controlled trial and controlled clinical trial. The outcomes included general effectiveness as nominal scale, and fatigue severity, insomnia severity and quality of life as interval or ratio scale. The meta-analysis and assessment of risk of bias was performed based on the data extracted from the selected trials. Results : The results of eight randomized controlled trials (n=596) were included in the meta-analysis. The results of the synthesis showed Gwibitang is beneficial substantially for relieving and managing the general symptoms, and its heterogeneity was not in important level (RR 0.26 [95% CI 0.17, 0.39], Z=6.47, P<0.00001, I2=0%). Gwibitang was beneficial for alleviating fatigue (SMD -0.78 [95% CI -1.27, -0.30], Z=3.17, P=0.002), but its certainty was low. In case of insomnia, too few trials had been found and their risk of bias was substantial, so no conclusions had been brought to. Conclusions : We found an evidence that Gwibitang could be beneficial for managing and alleviating main symptoms in CFS patients.

Demographic, Lifestyle, and Physical Health Predictors of Sickness Absenteeism in Nursing: A Meta-Analysis

  • Gohar, Basem;Lariviere, Michel;Lightfoot, Nancy;Lariviere, Celine;Wenghofer, Elizabeth;Nowrouzi-kia, Behdin
    • Safety and Health at Work
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    • 제12권4호
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    • pp.536-543
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    • 2021
  • Background: Sickness absenteeism is an area of concern in nursing and is more concerning given the recent impacts of the COVID-19 pandemic on healthcare. This study is one of two meta-analyses that examined sickness absenteeism in nursing. In this study, we examined demographic, lifestyle, and physical health predictors. Methods: We reviewed five databases (CINAHL, ProQuest Allied, ProQuest database theses, PsycINFO, and PubMed) for our search. We registered the systematic review (CRD de-identified) and followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. Additionally, we used the Population/Intervention/Comparison/Outcome Tool to improve our searches. Results: Following quality testing, 17 articles were used for quantitative synthesis. Female employees were at higher risks of sickness absenteeism than their male counterparts (OR = 1.73; 95% CI: 1.33-2.25). Nursing staff who rated their health as poor had a greater likelihood of experiencing sickness absence (OR = 1.38; 95% CI: 1.19-1.60). Also, previous sick leave predicted future leaves (OR = 3.35; 95% CI: 1.37-8.19). Moreover, experiencing musculoskeletal pain (OR = 2.41 95% CI: 1.77-3.27) increased the likelihood of sickness absence with greater odds when it is a back pain (OR = 3.05; 95% CI: 1.66-5.62). Increased age, physical activity, and sleep were not associated with sick leave. Conclusion: Several variables were statistically associated with the occurrence of sickness absenteeism. One primary concern is the limited research in this area despite alarming rates of sick leave in healthcare. More research is required to identify predictors of sickness absence, and thereby, implement preventative measures.

Periodontal parameters in orthodontically tractioned teeth: A systematic review and meta-analysis

  • de Mattos, Paola Marques;Goncalves, Flavio Magno;Basso, Isabela Bittencourt;Ferraz, Aline Xavier;Zeigelboim, Bianca Simone;Stechman-Neto, Jose;Santos, Rosane Sampaio;de Araujo, Cristiano Miranda;Guariza-Filho, Odilon
    • 대한치과교정학회지
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    • 제52권6호
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    • pp.420-431
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    • 2022
  • Objective: This systematic review aimed to evaluate periodontal parameters in orthodontically tractioned teeth compared with the respective non-tractioned contralateral teeth. Methods: Search strategies were developed for six electronic databases and gray literature. Random-effects meta-analyses were performed for the outcomes of interest. Furthermore, the certainty of the evidence was assessed using the GRADE (Grading of Recommendations Assessment, Development, and Evaluation) tool. Results: Overall, 2,082 articles were identified, of which 24 were selected for the qualitative synthesis. A significant difference was observed between the impacted and contralateral teeth (mean difference [MD] = 0.25; 95% confidence interval [CI] = 0.10-0.40; I2 = 0%) when the gingival index was evaluated. Additionally, impacted teeth showed a greater probing depth, with a significant mean difference between the groups (MD = 0.14; 95% CI = 0.07-0.20; I2 = 6%). Most studies had a low risk of bias; however, the certainty of the evidence was very low owing to the design of existing studies. Conclusions: The evidence in the literature indicated that tractioned teeth might show worsening of periodontal parameters related to the gingival index and probing depth; however, the evidence remains uncertain about this outcome. Furthermore, probing depth should be considered regarding its clinical significance because of the small effect size observed.

데이터통합과 메타분석을 위한 그래프 통계량 추출과 검증 (Statistical Data Extraction and Validation from Graph for Data Integration and Meta-analysis)

  • 심성률;임요환;홍명희;송규선;한현욱
    • 한국빅데이터학회지
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    • 제6권2호
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    • pp.61-70
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    • 2021
  • 본 연구의 목적은 개별연구들이 정확한 통계량을 제시하지 않고 그래프로만 나타내었을 경우 그래프로부터 통계량을 추출해내는 구체적인 방법을 기술한 것으로서 데이터통합과 정량적합성을 위한 메타분석을 가능하게 한다. 특히 메타분석(meta-analysis)은 체계적·객관적으로 대상문헌을 선택한 후 개별 연구들의 결과를 계량화하여 이를 통합된 효과크기(effect size)로 제시함으로써 근거중심의학(evidence based medicine)를 위한 올바른 의사결정을 할 수 있게 하는 중요한 분석도구이다. 데이터통합과 메타분석을 위해서 그래프로부터 정확한 통계수치를 추출하는 전산도구인 Adobe Acrobat Reader 와 Python기반의 JupyterLab 소프트웨어의 소개와 적용에 대한 주요사항을 알아보았다. 사용된 예제자료는 선행연구를 통해서 통계결과가 검증되어졌고 ClinicalTrials.gov에서 원자료 확보가 가능한 것을 사용하였다. 원자료와 각 전산도구들의 측정값을 각각 메타분석한 결과 통계적으로 유의한 차이는 없었다. 또한 연구자들간의 측정 신뢰도를 확인하였으며 높은 일치도를 나타내었다. 만약 그래프로부터 통게수치를 추출해야만 할 경우 연구의 완결성 유지를 위해서 전통적 사용 방법들보다는 전산 도구를 이용한 측정이 권고된다.

Chemical synthesis of processable conducting polyaniline derivative with free amine functional groups

  • Kar, Pradip
    • Advances in materials Research
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    • 제3권2호
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    • pp.117-128
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    • 2014
  • Processable conducting polyaniline derivative with free amine functional groups was successfully synthesized from the monomer o-phenylenediamine in aqueous hydrochloric acid medium using ammonium persulfate as an oxidative initiator. The synthesized poly(o-phenylenediamine) (PoPD) in critical condition was found to be completely soluble in common organic solvents like dimethyl sulfoxide, N,N-dimethyl formamide etc. From the intrinsic viscosity measurement, the optimum condition for the polymerization was established. The polymer was characterized by ultraviolet visible spectroscopy, Fourier transform infrared spectroscopy, proton magnetic resonance spectroscopy ($^1HNMR$) and thermogravimetric (TGA) analyses. The weight average molecular weights of the synthesized polymers were determined by the dynamic light scattering (DLS) method. From the spectroscopic analysis the structure was found to resemble that of polyaniline derivative with free amine functional groups attached to ortho/meta position in the phenyl ring. However, very little ladder unit was also present with in the polymer chain. The moderate thermal stability of the synthesized polymer could be found from the TGA analysis. The average DC conductivity of $2.8{\times}10^{-4}S/cm$ was observed for the synthesized polymer pellet after doping with hydrochloric acid.

열화학기상증착법을 이용한 GaN nanowire 합성 (Synthesis of GaN nanowires using thermal chemical vapor deposition)

  • 류승철;이태재;이철진
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2001년도 하계학술대회 논문집
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    • pp.931-934
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    • 2001
  • GaN nanowires has much interest as one-dimensional materials for blue light LED. GaN-based materials have been the subject of intensive research for blue light emission and high temperature/high power electronic devices. In this letter, the synthesis of GaN nanowires by the reaction of mixture of GaN nanowires by the reaction of mixture of Ga meta and GaN powder with NH$_3$ using thermal chemical vapor deposition is reported. X-ray diffraction, energy dispersive x-ray spectrometer, scanning electron microscopy, and transmission electron microscopy indicate that those GaN nanowires with hexagonal wurtzite structure were about 60nm in diameter and up to several hundreds of micrometers in length.

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p-TSA를 이용한 퀴놀론 유도체의 비대칭 이합체 합성 (Synthesis of Asymmetric Dimer of Quinolone Derivatives Using p-TSA)

  • 박명숙
    • 약학회지
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    • 제48권3호
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    • pp.202-206
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    • 2004
  • New asymmetric dimers, N,N'-dialkyl-4'-hydroxy-4-oxo-2,2',3,3'-tetrahydro-2,2'-diphenyl-4,4'-quinolones 3a-f were synthesized through the dehydration and dea1coholation of N-alkylanilines and ethyl benzoylacetate. Dimers 3a-f were identified by NMR, IR and GC-MS. A series of dimer 3a-f has been synthesized using acid-catalyzed one-pot reaction that involved the condensation, cyc1ization and dimerization. Similarly, the 6,6'-methoxy (or 7,7'-methoxy) substituted dimers were prepared from N-alkyl-meta-(or para)-anisidines. Formation of dimers was undertaken with p-toluenesulfonic acid (p-TSA) at 90∼11$0^{\circ}C$ in toluene for 2∼6 hours over the Dean-Stark apparatus.

마갈드레이트의 합성조건과 그 현탁액의 유동학적 특성 (Synthesis Conditions of Magaldrate and Rheological Characteristics of its Aqueous Suspensions)

  • 신화우;최광식
    • 약학회지
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    • 제40권1호
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    • pp.25-35
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    • 1996
  • Magaldrate. an antiacid was synthesized by reacting magnesium oxide, aluminum sulfate, and dried aluminum hydroxide gel. The optimum synthesis conditions based on the yield of t he product were established by applying Box-Wilson experimental design. It was found that the optimum synthesis conditions of Magaldrate were as follows: Reaction temperature; 61~$85{\circ}C$, concentration of two reactants. Mgo and $Al(OH)_3$: 16~19.8%, molar concentration ratio of two reactants, [MgO]/[$Al(OH)_3$]; 4.2~5.0, temperature of washing water; 36~$41^{\circ}C$ and drying temperature of the product: 76~$80^{\circ}C$. Magaldrate was synthesized under the optimum synthesis conditions and identified by analyzing the chemical composition, and by differential scanning calorimetry and X-ray diffraction method. The Magaldrate sample synthesis under these conditions was used to prepare 15.6% Magaldrate original suspension which was utilized to make 13% Magaldrate suspension dispered in various concentrations of eight types of suspending agents. The acid-neutralizing capacity of 13% Magaldrate suspension dispersed in 0.25% suspending agents was examined by Rosset-Rice method. The maximum pH was reached within 1 minute in all suspension tested, and duration maintained between pH 3~5 was decreased in the order of Na alginate Na silicate(meta) Veegum HV pectin agar>Na>CMC>xanthan gum>bentonite. It was found that the hysteresis loop area was increased with temperature in the case of Riopan Plus and the addition of agar, whereas the area was decreased with temperature in the case of the addition of Na alginate and xanthan gum. 13% Magaldrate suspension tends to sediment by the addition of bentonite.

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