• 제목/요약/키워드: B13

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IDT형의 전극 형태가 SFIT형 필터의 특성에 미치는 영향 (The effects of the shape of IDT electrode pair on the characteristics of SFIT filter)

  • 유일현
    • 한국정보통신학회논문지
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    • 제13권12호
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    • pp.2662-2670
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    • 2009
  • 반사기 형태에 따른 경사진 빗살무늬 변환기 SAW 필터 특성을 비교하기 위해 모의실험을 통해 Langasite 기판위에 전극을 형성시켰으며, 전극재료로는 Al-Cu를 사용하였다. 모의실험을 바탕으로 입력단에는 IDT를 직렬형태로 연결시킨 block 형태로 하중을 가하는 전극 방법을 쓰고 출력단은 withdrawal 형태로 하중을 가하는 방법을 써서 제작하였다. 이를 바탕으로 광대역의 SAW 필터 전극 설계 방식에 대한 적절한 위상조건도 얻고자 시도하였다. Langasite 기판위에 형성시킨 입 출력빗살무늬 변환기 전극수는 50쌍, 두께는$5000{\AA}$으로 하였으며, 반사기 폭과 간격은 각각 $3.6{\mu}m$$2.0{\mu}m$으로 하였다. 제작한필터의 주파수 특성은 중심주파수가 대략 190MHz정도, 대역폭은 8.0MHz 정도로 측정되었으며, matching 후 return-loss는 -16dB 이하이고, 리플 특성은 4dB 정도이며, 반사에 의한 잔향은 -20dB 이하로 측정되었다.

Prevalence and Cytotoxic Effects of Some Colibactin and cnf Genes among Escherichia coli Isolated from Urinary Tract Infections

  • Alhadidi, Hiba A.S.;Al-Qaysi, Safaa A. S.;Al-Halbosiy, Mohammad M. F.
    • 한국미생물·생명공학회지
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    • 제50권2호
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    • pp.283-292
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    • 2022
  • Colibactins (clb) and Cytotoxic Necrotizing Factors (cnf) are virulence factors that impact cell cycle through cellular differentiation, proliferation, and apoptosis. Urinary tract infections (UTIs) are the most common among type of infection among outpatients, with a lifetime incidence of about 60-65% in adult females. Here, we sought to isolate uropathogenic Escherichia coli (UPCE) from urine specimens and investigates the prevalence of clb A, B and cnf 1, 2 genes among these isolates. A total of 110 E. coli isolates were collected from patients with UTIs. All the isolates were examined for their hemolytic activity and only 46 isolates showed a halo zone of hemolysis on blood agar. The collected UPEC isolates were screened for the existence of clb A, B and cnf genes. The results revealed that out of 110 isolates, 28 harbored the clbA gene, 40 harbored clb B, and 24 isolates harboured cnf1. 13 isolates harbored clbA, clbB, and cnf1 genes, while no cnf2 gene was detected among isolates. The molecular detection revealed that 8 out of 28 hemolytic isolates carrying the clbA, 11 out of 40 were carrying clbB, 1 out of 24 were carrying cnf 1, and 5 out of 9 carrying clbA+clbB. Furthermore, 7 out of 13 isolates were hemolytic and carrying clbA, clbB, and cnf1 genes. Finally, we investigated the cytotoxicity of E. coli harboring clb and cnf genes, eukaryotic REF cells were exposed to E. coli producing colibactin, which induces DNA damage and leads to cell cycle arrest, senescence and death.

낙동강하구 새섬매자기(Bolboschoenus planiculmis) 복원 모니터링: 식물체(shoot) 식재를 이용한 습지복원 (Monitoring on Bolboschoenus planiculmis Restoration in Nakdong River Estuary: Implications for Wetland Restoration Using Shoot Transplantation)

  • 김구연;박희순;김화영;이지영
    • 생태와환경
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    • 제55권4호
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    • pp.406-414
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    • 2022
  • Bolboschoenus planiculmis has been acknowledged as a key species in whooper swans (Cygnus cygnus) habitat by providing food for this migratory waterfowl. B. planiculmis wetlands are being degraded by water shortages and salinization caused by anthropogenic activities and climate changes. In 2004, the distribution of B. planiculmis in the tidal flats of the Nakdong Estuary was 2,475,568 m2, and in 2021, the distribution area was 798,731 m2, which decreased by 32.3%. In order to restore the degraded B. planiculmis wetlands, shoot transplantation and seed sowing were tentatively used in three places with different salinity and water levels. The average density per unit area in September at the optimal growth period after planting were A (fresh water level 50 cm) 58±15.65 m-2, B (brackish water level 0~5 cm) 188±63.83 m-2, C (brackish water level 0 cm or less) 188±45.13 m-2. The tubers were observed as A 0 g dw m-2, B 25.32±2.94 g dw m-2, and C 13.39±0.91 g dw m-2. Tubers were distributed in the soil, with only 3.0% at the 10~20 cm depth but 97.0% at the 0~10 cm depth. In contrast, the germination rate of B. planiculmis seeds was observed to be 0%. Results of this study provide technical support for the restoration of B. planiculmis wetland and the improvement in the quality of whooper swans habitat.

Identification of Hepatitis B (HBV) and C (HCV) Virus Infection among Doctors and Nurses in Tertiary Hospitals in Mongolia

  • Batbold, D.;Baigalmaa, Dovdon;Ganbaatar, B.;Chimedsuren, O.
    • Perspectives in Nursing Science
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    • 제7권1호
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    • pp.50-54
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    • 2010
  • The studies of M. Colombo (1989) and W. Lange (1992) showed that 30~40% of people became chronic after suffering from hepatitis B virus (HBV) and C virus (HCV) infection, and about 50% of the chronic cases transformed into primary liver cancer. There have been few studies done in Mongolia on hepatitis infection among health professionals, particularly in nurses. In a study done by Chimedsuren (8), the study showed that 19.4% of people with identified surface hepatitis B antigen (HBsAg) and antibodies to hepatitis C virus and 8% of people with the identified nucleotide of RNA for the hepatitis C virus (polymerase chain reaction) had an acute form of hepatitis C. Studies on the hepatitis virus genome damaging effect on liver cells showed that genotype 8 (A, B, C, D, E, F, G, TTV) had the most damaging effect on liver cells (Hahn and Faeka, 2007). Several studies have shown a relationship between hepatitis B virus infection and a lack of compliance regarding safety regulations and rules by medical personnel. Results of a study from the Maternal and Child Health Research Center showed that tests done to detect hepatitis B virus antigen and antibodies to C virus did not reveal anything. Both antigen and antibodies in 69% cases did not show, and separately, B virus and antibodies to hepatitis C virus were identified in 13% and 9%, respectively. Results of the tests taken from health personnel in Shastin Central Hospital showed that in 76% of the cases, the B virus antigen with C virus antibodies was not identified. In 8% of the cases, the B virus antigen was present on its own. The combination of B the virus antigen and C virus antibodies were present in 8% of nurses and doctors, respectively. 82% of the cases had negative results for the detection of a combination of B virus antigen and C virus antibodies taken from health personnel from the State Central Clinical Hospital whereas the B virus antigen and C virus antibodies by themselves were present in 7% and 14% of the cases, respectively. Combined cases of the B virus antigen and C virus antibodies were identified in 4% of the personnel. Results of the tests taken from the health personnel in the Hospital of the Ministry of Justice and Internal Affairs showed that in 79% of the cases, the B virus antigen with C virus antibodies were not identified. Separately, the B virus and antibodies to hepatitis C virus were identified in 8% and 13% of the cases, respectively.

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Variab1e stars in the intermediate-age open cluster NGC 2301

  • Kim, S.L;Park, B.G.;Lee, S.H.;Sung, H.;Chun, M.Y.;Ann, H.B.;Lee, M.G.;Jeon, Y.B.;Yuk, I.S.
    • 한국우주과학회:학술대회논문집(한국우주과학회보)
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    • 한국우주과학회 1999년도 한국우주과학회보 제8권2호
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    • pp.13-14
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    • 1999
  • No Abstract, See Full Text

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DNA-DNA hybridization에 의한 Bacillus coagulans의 분류학적 연구

  • 정지관
    • 한국미생물생명공학회:학술대회논문집
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    • 한국미생물생명공학회 1976년도 제8회 학술발표회
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    • pp.187.4-188
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    • 1976
  • 서로 다른 11주의 Bacillus coagulans와 13종의 Bacillus 속 14주를 deoxyribonucleic acid (DNA) -DNA hybridization method에 의해서 분류학적인 연구를 하였다. 사용한 B. coagulans 11주종 6주는 흙에서(일본 오사까교회) 분리했고 나머지 5주는 ATCC, IFO에서 authentic strains을 얻어서 사용했다. 사용된 B. coagulans는 Bergey's Manual(8 thed)에 의거 Grodon씨들의 방법으로 동정한 결과 B. coagulans로서 확인되었다.(중략)

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SLIN FOR WEIGHTED SUMS OF STOCHASTICALLY DOMINATED PAIRWISE INDEPENDENT RANDOM VARIABLES

  • Sung, Soo-Hak
    • 대한수학회논문집
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    • 제13권2호
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    • pp.377-384
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    • 1998
  • Let ${X_n,n \geq 1}$ be a sequence of stochatically dominated pairwise independent random variables. Let ${a_n, n \geq 1}$ and ${b_n, n \geq 1}$ be seqence of constants such that $a_n \neq 0$ and $0 < b_n \uparrow \infty$. A strong law large numbers of the form $\sum^{n}_{j=1}{a_j X_i//b_n \to 0$ almost surely is obtained.

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공존하는 미국산 Bathynellidae과의 두 신종 (Two new sympatric species of the family Bathynellidae from North America (Crustacea, Syncarida, Bathynellacea))

  • 조주래;김주필
    • Animal Systematics, Evolution and Diversity
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    • 제13권1호
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    • pp.61-72
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    • 1997
  • 한 서식지에 공존하는 Bathynellidae과의 두 신종을 기록하였다. Bathynella germanitas n. sp.는 Uropod의 Endopod에 실린더 모양의 돌기를 갖고 있는 것이 특징이며 B.fraterna n. sp.는 흉각지들의 Exopod에 존재하는 강모에 의해 특징이 지워진다.

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