• 제목/요약/키워드: R-404A

검색결과 180건 처리시간 0.024초

The Effectiveness of Community-based Social Distancing for Mitigating the Spread of the COVID-19 Pandemic in Turkey

  • Durmus, Hasan;Gokler, Mehmet Enes;Metintas, Selma
    • Journal of Preventive Medicine and Public Health
    • /
    • 제53권6호
    • /
    • pp.397-404
    • /
    • 2020
  • Objectives: The objective of this study was to demonstrate the effects of community-based social distancing interventions after the first coronavirus disease 2019 (COVID-19) case in Turkey on the course of the pandemic and to determine the number of prevented cases. Methods: In this ecological study, the interventions implemented in response to the first COVID-19 cases in Turkey were evaluated and the effect of the interventions was demonstrated by calculating the effective reproduction number (Rt) of severe acute respiratory syndrome coro navirus 2 (SARS-CoV-2) when people complied with community-based social distancing rules. Results: Google mobility scores decreased by an average of 36.33±22.41 points (range, 2.60 to 84.80) and a median of 43.80 points (interquartile range [IQR], 24.90 to 50.25). The interventions caused the calculated Rt to decrease to 1.88 (95% confidence interval, 1.87 to 1.89). The median growth rate was 19.90% (IQR, 10.90 to 53.90). A positive correlation was found between Google mobility data and Rt (r=0.783; p<0.001). The expected number of cases if the growth rate had not changed was predicted according to Google mobility categories, and it was estimated to be 1 381 922 in total. Thus, community-based interventions were estimated to have prevented 1 299 593 people from being infected. Conclusions: Community-based social distancing interventions significantly decreased the Rt of COVID-19 by reducing human mobility, and thereby prevented many people from becoming infected. Another important result of this study is that it shows health policymakers that data on human mobility in the community obtained via mobile phones can be a guide for measures to be taken.

Role of Alkaline Serine Protease, Asp, in Vibrio alginolyticus Virulence and Regulation of Its Expression by LuxO-LuxR Regulatory System

  • Rui, Haopeng;Liu, Qin;Wang, Qiyao;Ma, Yue;Liu, Huan;Shi, Cunbin;Zhang, Yuanxing
    • Journal of Microbiology and Biotechnology
    • /
    • 제19권5호
    • /
    • pp.431-438
    • /
    • 2009
  • The alkaline serine protease asp, which was shown to be a virulence factor of Vibrio alginolyticus as a purified protein, was cloned from V. alginolyticus EPGS, a strain recently isolated from moribund Epinephelus coioides in an outbreak of vibriosis in a mariculture farm of Shenzhen. The asp null mutant was constructed by homologous recombination with suicide plasmid pNQ705-1. Compared with the wild-type strain, the asp null mutant exhibited a significant decrease of total extracellular protease activity, and caused a IS-fold decrease in virulence of V. alginolyticus. In our previous study, the luxO and $luxR_{val}$ genes from V. alginolyticus MVP01 were cloned and identified, and the luxO-$luxR_{val}$ regulatory couple was shown to regulate various genes expression, suggesting that it played a central role in the quorum sensing system of V. alginolyticus. In this study, the regulation of the asp gene was analyzed by using RT-PCR and quantitative real-time PCR methods; we proved that its transcription was greatly induced at the late stage of growth and was regulated by a luxO-$luxR_{val}$ regulatory system.

납작관의 종횡비가 R-410A 증발열전달 및 압력손실에 미치는 영향 (Effect of Aspect Ratio of Flat Tube on R410A Evaporation Heat Transfer and Pressure Drop)

  • 김내현;이을종;변호원
    • 대한기계학회논문집B
    • /
    • 제37권4호
    • /
    • pp.395-404
    • /
    • 2013
  • 본 연구에서는 내경 5.0mm 원관을 납작하게 한 납작관에 대하여 R-410A를 사용하여 증발열전달 실험을 수행하였다. 실험은 포화온도를 $15^{\circ}C$로 고정한 상태에서 열유속을 $5{\sim}15kW/m^2$, 질량유속을 $200{\sim}400kg/m^2s$로 변화시키며 수행되었다. 실험결과 납작관의 종횡비가 증가할수록 열전달계수와 압력손실 모두 증가하였는데 특히 종횡비 4 인 경우 증가폭이 현저하였다. 납작관의 실험결과를 기존 상관식들과 비교한 결과 열전달계수는 Shah 상관식, 마찰계수는 Jung and Radermacher 상관식이 적절히 예측하였다.

Imidazoline계 양이온 계면활성제 분석 (Analysis of Imidazoline Type Cationic Surfactants)

  • 박홍순;최규열;이재덕;김여경;안호정
    • 공업화학
    • /
    • 제9권3호
    • /
    • pp.404-406
    • /
    • 1998
  • 가스 크로마토그래피(GC)와 가스 크로마토그래피(HPLC)를 이용하여 imidazoline계 양이온 계면활성제 분석을 수행하였다. 염기 가수분해와 산 가수분해 후 GC로 imidazoline ring의 original fatty acid의 alkyl chain 분포를 조사하였다. 역상 C18 분리관을 사용하고 0.1M $NaClO_4$가 함유된 methanol과 acetonitrile의 50:50(v/v)액을 용리액으로 할 때 imidazoline의 homologous한 total alkyl chain 분포가 HPLC에서 훌륭하게 분리되었으며, GC 결과와 좋은 일치를 보여주었다. 본 연구의 분석법으로, imidazoline계 양이온 계면활성제의 소수성 alkyl chain 분석 및 평균 분자량 결정이 가능하였으며, 전처리 필요없이 HPLC법을 이용한 imidazoline 의 검출한계는 10ng이었다.

  • PDF

목포 주변 해역 갯벌 조간대에 서식하는 종밋

  • 임현식;박경양
    • 한국패류학회지
    • /
    • 제14권2호
    • /
    • pp.121-130
    • /
    • 1998
  • Studies on the distribution and growth of the mud mussel, Musculista senhousia, were carried out in the mud-tidal flat near Mokpo from August 1996 to July 1997. The patch distribution of the mussel was observed in the middle part of the tidalflat during the study period. Annual mean density was 8,215${\pm}$1,394 ind./m2 and annual mean biomass was 1,966.43${\pm}$668.49 g TWwt/m2 in total wet weight, 760.04${\pm}$279.13 gMWwt/m2 in meat wet weight, 209.93 ${\pm}$ 49.41 gMDwt/m2 in meat dry weight, and 109.66${\pm}$58.78 gAFDW/m2 in ash-free dry weight. The monthly mean size of shell length varied from 11.00 mm to 16.97 mm. Relationship between shell length (SL) and shell height (SH) showed a positively significant regression (SH=0.482SL+0.791, R2=0.940, P<0.001). Regressions of total wet weight (TWwt) (TWwt=7.601${\times}$10-5SL3.052, R2=0.905, P<0.001), and meat wet weight (MWwt) (MWwt=1.127${\times}$10-5${\times}$SL3.404, R2=0.784, P<0.001) on shell length were positively allometric, with highly significant correlation coefficient. The relationships between SL and meat dry weight (MDwt), and AFDW were MDwt=9.813${\times}$10-6${\times}$SL2.928 (R2=0.421), and AFDW=1.015${\times}$10-5${\times}$SL2.922(R2=0.810), respectively. The condition factor of the mussel has been increased from March and formed a peak in July and August. It was sharply dropped in September. These results suggest that the gonadal development of the species commenced to be occurred in spring and that main spawning occurred between August and September.

  • PDF

디지털 오디오 주관적 음향레벨 계측기 구현을 위한 ITU-R BS. 1387-1의 알고리즘 특성 분석 (Performance analysis of subjective Loudness meter with ITU-R BS. 1387-1 algorithm for digital audio)

  • 뉴엔 보 바오 느안;박성균;노승환;한찬규
    • 전기전자학회논문지
    • /
    • 제16권4호
    • /
    • pp.395-404
    • /
    • 2012
  • 본 논문에서는 객관적 오디오 품질 분석에 대한 권고안인 ITU-R BS.1387-1의 귀의 모델을 토대로 라우드니스를 객관적으로 측정할 수 있는 알고리즘을 구현하며, 그 성능을 23개의 순음과 9개의 샘플 디지털 사운드에 적용하여 평가하였다. 순음의 경우 ISO226:2003에서 제공하는 실험 데이터와 비교한 결과 5%이하의 오차를 보이며, 디지털 사운드 실험 결과도 Moore 모델의 측정결과와 비교할 때 4.7%이하의 편차와 0.96이상의 코릴레이션을 나타내어 좋은 성능을 보였다. 한편 구현 알고리즘에 적용한 청각필터 수에 따른 성능 변화를 분석하기 위해 21개의 별도의 샘플 디지털 사운드에 적용하였다. 그 결과를 분석하여 보면, 37개의 청각필터를 갖는 구현 알고리즘에 바이어스 보상값을 적용함으로써 109개 필터를 사용하는 경우에 대해 2%미만의 오차를 갖는 양호한 성능을 갖도록 할 수 있었다.

계통분류학적 연구를 위한 우포늪에서 분리된 박테리아 Spirosoma rigui KCTC 12531T의 완전한 게놈 서열 (Complete genome sequence of Spirosoma rigui KCTC 12531T, a bacterium isolated from fresh water from the Woopo wetland for taxonomic study)

  • 김동욱;김주영;김수정;김민지;이주연;김명겸
    • 미생물학회지
    • /
    • 제53권3호
    • /
    • pp.227-229
    • /
    • 2017
  • 이 연구에서는 우포늪의 깨끗한 물에서 분리된 Spirosoma rigui KCTC $12531^T$의 완전한 게놈 서열을 분석하였다. 이 게놈은 G + C 함량이 54.4%인 5,828,404 bp으로 구성되어 있고 4,774개의 유전자와 4,647개의 단백질 코딩 유전자, 9개의 rRNA 유전자 그리고 43개의 tRNA 유전자 및 73개의 위유전자(pseudogene)를 포함하고 있다.

SPATE에 의한 등방성체의 응력확대계수 측정 (Measurement of Stress Intensity Factor of Isotropic Material Using SPATE)

  • 황재석;서재국;이효재;남정환;;최영철
    • 대한기계학회논문집A
    • /
    • 제21권3호
    • /
    • pp.393-404
    • /
    • 1997
  • SPATE(Stress Pattern Analysis by Thermal Emission) can be effectively used to analyze the stress distributions of isotropic structure under the repeated load by non-contact. In this research, the measuring method and the measuring concept of stress intensity factor of isotropic material by SPATE are suggested. The validity of the method and the concept was certified through SPATE experiment.

Mechanosensitive β-catenin signaling regulates lymphatic vascular development

  • Cha, Boksik;Srinivasan, R. Sathish
    • BMB Reports
    • /
    • 제49권8호
    • /
    • pp.403-404
    • /
    • 2016
  • The Wnt/β-catenin signaling is an evolutionarily conserved pathway that plays a pivotal role in embryonic development and adult homeostasis. However, we have limited information about the involvement of Wnt/β-catenin signaling in the lymphatic vascular system that regulates fluid homeostasis by absorbing interstitial fluid and returning it to blood circulation. In this recent publication we report that canonical Wnt/β-catenin signaling is highly active and critical for the formation of lymphovenus valves (LVVs) and lymphatic valves (LVs). β-catenin directly associates with the regulatory elements of the lymphedema-associated transcription factor, FOXC2 and activates its expression in an oscillatory shear stress (OSS)-dependent manner. The phenotype of β-catenin null embryos was rescued by FOXC2 overexpression. These results suggest that Wnt/β-catenin signaling is a mechanotransducer that links fluid force with lymphatic vascular development.

충남대 여대생의 철분 섭취량과 영양 상태에 대한 연구 (A Survey on Iron Intake and Nutritional Status of Female College Students of Chungnam National University)

  • 남혜선
    • Journal of Nutrition and Health
    • /
    • 제25권5호
    • /
    • pp.404-412
    • /
    • 1992
  • Iron intake and nutritional status of 99 female college students of Chungnam Natiional Unive-rsity were estimateed with dietary survey and measurement of hematological indices including the level of serum ferritin Food intake was measured using the weighing method and iron availability per meal was calculated according to Monsen and Hallberg. The average daily intakes of protein vitamin C. total iron and also total available amount of iron were higher than the Korean R.D.A. The blood indices for iron status however showed that iron status of the subjects was inade-quate. Furthermore the serum ferritin levels indicated marginal iron storage in 75% of the subjects.

  • PDF