• Archives of Pharmacal Research
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• 제27권2호
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• pp.206-216
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• 2004

The functional role of protein carboxylmethylation (PCM) has not yet been clearly elucidated in the tissue level. The biochemical feature of PCM in porcine spleen was therefore studied by investigating the methyl accepting capacity (MAC) of natural endogenous substrate proteins for protein carboxyl O-methyltransferase (PCMT) in various conditions. Strong acidic and alkaline-conditioned (at pH 11.0) analyses of the MAC indicated that approximately 65％ of total protein methylation seemed to be mediated by spleen PCMT. The hydrolytic kinetics of the PCM products, such as carboxylmethylesters (CMEs), under mild alkaline conditions revealed that there may be three different kinds of CMEs [displaying half-times (T$_{1}$2/) of 1.1 min (82.7％ of total CMEs), 13.9 min (4.6％), and 478.0 min (12.7％)], assuming that the majority of CME is base-labile and may be catalyzed by class I PCMT. In agreement with these results, several natural endogenous substrate proteins (14, 31 and 86 kDa) were identified strikingly by acidic-conditioned electrophoresis, and their MAC was lost upon alkaline conditions. On the other hand, other proteins (23 and 62 kDa) weakly appeared under alkaline conditions, indicating that PCM mediated by class II or III PCMT may be a minor reaction. The MAC of an isolated endogenous substrate protein (23-kDa) was also detected upon acidic-conditioned electrophoresis. Therefore, our date suggest that most spleen PCM may be catalyzed by class I PCMT, which participates in repairing aged proteins.

• 대한전자공학회논문지TC
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• 제37권1호
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• pp.32-43
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• 2000

본 논문에서는 패킹 방식 CDMA 망에서 기존에 제시되었던 음성과 데이터 통합 서비스를 위한 매체 접근 제어(Medium Access Control: MAC) 프로토콜들이 갖는 문제점들을 고찰하고 이를 극복할 수 있는 새로운 접근 방법을 제시하였다. 본 논문에서는 동기식 다중코드 CDMA 시스템에서 중앙의 기지국이 모든 단말의 트래픽 상태를 우선권(priority)에 의해 파악하고 이에 따라 패킷 단위로 채널을 할당함으로써 음성과 데이터 서비스를 효율적으로 통합할 수 있는 Prioritized Packet Reservation CDMA ($P^2R$-CDMA) 프로토콜을 제안하고, 모의 실험을 통해 음성과 데이터 트래픽이 요구하는 서비스 품질을 보장하면서 다중화 이득을 극대화함으로써 전송 허가 확률의 제어를 기반으로 하는 기존의 방식보다 시스템 용량을 향상시킬 수 있음을 확인하였다.

• Nuclear Engineering and Technology
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• 제54권3호
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• pp.1049-1061
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• 2022

Neutron and gamma-ray shielding properties of Inconel 718 reinforced B₄C (0-25 wt%) were investigated using PSD software. Mean free path (MFP), linear and mass attenuation coefficients (LAC,MAC), tenth-value and half-value layers (TVL,HVL), effective atomic number (Z_eff), exposure buildup factors (EBF), and fast neutron removal cross-sections (FNRC) values were calculated for 0.015-15 MeV. It was found that MAC and LAC increased with the decrease in the content of B₄C compound by weight in Inconel 718. The EBFs were computed using G-P fitting method for 0.015-15 MeV up to the penetration depth of 40 mfp. HVL, TVL, and FNRC values were found to range between 0.018 cm and 3.6 cm, between 2.46 cm and 12.087 cm, and between 0.159 cm^-1 and 0.194 cm^-1, respectively. While Inconel 718 provides the maximum photon shielding property since it offered the highest values of MAC and Z_eff and the lowest value of HVL, Inconel 718 with B₄C(25 wt%) was observed to provide the best shielding material for neutron since it offered the highest FNRC value. The study is original in terms of several aspects; moreover, the results of the study may be used in nuclear technology, as well as other technologies including nano and space technologies.

• Journal of Nutrition and Health
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• 제36권4호
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• pp.397-404
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• 2003

The present study was designed to compare the nutritional status of hemodialysis (HD) and continuous ambulatory peritoneal dialysis (CAPD) patients. Subjects were 58 HD patients (male/female = 29/29) and 33 CAPD patients (male/female = 23/10) undergoing dialysis treatment in Artificial Kidney Unit of Chonbuk National University Hospital. For nutritional assessment, %IBW (ideal body weight), %TSF (tricep skin fold), %MAC (mid arm circumference), %MAMC (mid arm muscle circumference), serum albumin, serum transferrin, TLC (total lymphocyte count), SGA (subjective global assessment) and estimated energy and protein intakes by 1-month food frequency method were used. Between HD and CAPD group, mean age (50 $\pm$ 12 vs. 52 $\pm$ 12 yr), dialysis durations (37 $\pm$ 36 vs. 30 $\pm$ 26 mon), dietary energy intakes (28.3 $\pm$ 9.0 vs. 28.8 $\pm$ 8.6 kcal/kg/day), dietary protein intakes (1.1 $\pm$ 0.4 vs. 1.2 $\pm$ 0.3 g/kg/day) and incidence of co-morbid conditions (69.0% vs. 69.7%) were not significantly different. Data by using SGA showed a higher incidence of malnutrition in CAPD patients (45.6%) than in HD patients (36.2%). %IBW (p < 0.001), %TSF (p < 0.001) and %MAC (p < 0.001) were higher in CAPD patients than were in HD patients. But serum albumin (p < 0.001) and transferrin (p < 0.001) were significantly lower in CAPD patients than were in HD patients. A higher incidence of malnutrition was shown in CAPD Patients than in HD Patients due to different dialysis type. A significant finding was that CAPD showed protein deficient malnutrition and HD did calorie deficient malnutrition. It suggests that an adequate dietary intake considering dialysis type prevents a prevalence of malnutrition.

• 대한간호학회지
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• 제38권2호
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• pp.270-277
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• 2008

Purpose: This study was done to identify predictors of the fighting spirit or helplessness/hopelessness in the patients' mental adjustment to cancer. Cancer patients' characteristics like performance status, metastasis and duration of diagnosis with demographic factors, spiritual support and social support were used as predictors of a fighting spirit or helplessness/hopelessness. Methods: A total of 124 ambulatory cancer patients completed the Mental Adjustment to Cancer (MAC) scale and responded in a structured instrument about their characteristics, spiritual and social support. Results: The results of multiple regression analysis revealed that confidence in the supporter ($R^2=.114$, p=.000), duration of cancer diagnosis ($R^2=.041$, p=.000) and faith ($R^2=.030$, p=.000) were predictive of a fighting spirit ($R^2=.185$, p=.000); whereas, education ($R^2= .074$, p=.001), performance status ($R^2=.055$, p=.000), satisfaction with social support ($R^2=.046$, p=.000), and metastasis ($R^2=.037$, p=.000) were predictive of helplessness/hopelessness ($R^2=.202$, p=.000). Conclusion: Social support, spiritual support and disease related factors like metastasis, performance status, and duration of cancer diagnosis need to be considered in a psychosocial nursing intervention for a fighting spirit or helplessness/hopelessness.

• 한국통신학회논문지
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• 제34권5B호
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• pp.463-468
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• 2009

차량 간 통신에서는 무선 랜을 기반으로 한 연구가 활발히 진행되고 있으며, IEEE 802.11p WAVE(Wireless Access in the Vehicular Environment)에서도 802.11a를 기반으로 한 방식을 채택하고 있다. 하지만 무선 랜 방식은 하나의 채널을 경쟁 모드로 사용하기 때문에 빠른 접속을 요구하는 차량 환경에서 경쟁을 회피하기 위해 CSMA/CA(Carrier Sense multiple Access/Collision Avoidance) 알고리즘을 사용하는 것은 찾은 충돌로 인한 통신 지연을 유발 할 수 있다. 본 논문에서는 차량 간 통신에서 이러한 문제점을 해결하고 신뢰성 있는 데이터 전송을 지원하기 위하여 차량 환경에 적합한 클러스터링 기반의 멀티채널 매체접속제어 프로토콜을 설계하고 설계된 프로토콜을 바탕으로 차량 간 통신에 적합한 채널 조건을 확인하였다 클러스터 헤드를 통해 각 채널을 관리하고 채널을 할당함으로써 기존 경쟁 기반의 싱글 채널을 사용함에 따라 생기는 패킷 충돌 및 통신 지연을 60%이상 줄이는 것을 시뮬레이션을 통해 확인 하였다.

• 대한전자공학회논문지TC
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• 제37권2호
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• pp.7-16
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• 2000

본 논문에서는 p-persistent CSMA 방식의 IEEE 802.11 MAC 계층 프로토콜을 모델링 하였다. 그리고 renewal 이론을 적용하여 수학적으로 분석한 Basic CSMA/CA 프로토콜, CTS/RTS 프로토콜 그리고 은닉 노드를 고려한 Basic CSMA/CA 등의 성능분석모델을 제안하였다. 제안한 분석 모델을 이용하여 throughput을 구한 결과, active 노드 수가 적거나 패킷의 길이가 짧을 때는 Basic CSMA/CA 프로토콜 방식이, active 노드 수가 많거나 패킷의 길이가 길 때는 CTS/RTS 프로토콜 방식이 우수하였다. 또한 active 노드 수가 적은 경우가 많은 경우 보다 은닉 노드의 영향을 적게 받았다.

• 한국임상약학회지
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• 제22권2호
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• pp.123-130
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• 2012

거대세포바이러스(Cytomegalovirus; CMV) 감염은 동종조혈모세포이식 환자의 주요 사망원인 중 하나이다. 용량감소전처치(Reduced-intensity conditioning; RIC)를 이용한 조혈모세포이식은 골수억제전처치(Myeloablative conditioning; MAC)에 비해 골수억제 및 면역억제가 적으므로 CMV 감염 발생율을 감소시킬 것이라 예상되었으나 예방적 면역억제요법, T세포 제거 약제의 사용 등으로 서로 상이한 결과가 보고되고 있다. 2007년 1월부터 2009년 12월까지 총 141명의 환자(MAC 113명, RIC 28명)가 동종조혈모세포이식을 받았으며, CMV 감염은 MAC 62.8%, RIC 57.1% (p = 0.310), CMV 질환은 각각 12.4%, 14.3% (p = 0.785)에서 발생하였다. CMV 감염/질환 발생빈도와 CMV 항원 혈증검사 지속기간, 초기/최고치, 생존율은 두 군간 유의한 차이가 없었다. CMV 감염 위험인자에 대한 다변량분석 결과, 환자가 고령일수록(HR 1.024, 95% CI 1.002-1.045; p = 0.031) 또는 grade 2 이상의 급성 이식편대숙주병이 발생한 경우에(HR 1.849, 95% CI 1.031-3.315; p=0.039) CMV 감염 발생 위험율이 유의하게 높았다. 결론적으로, 전처치요법 강도에 따른 CMV 감염의 발생빈도와 발현양상의 차이는 없었으나, 고령이거나 grade 2 이상의 급성 이식편대숙주병이 발생한 환자의 경우 CMV 감염 발생과 유의한 연관성을 보였다. 이상과 같은 결과에 비춰 봐서 CMV 질환이 대부분 이식 100일 이후에 발생한 점을 고려할 때, 이식 후 CMV 감염 발생 시 ganciclovir 선제요법과 함께 이들 환자들에게 지속적인 모니터링을 실시하는 것이 필요할 것으로 사료된다.

• 한국동물생명공학회지
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• 제36권2호
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• pp.91-98
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• 2021

The objective of this study was to establish a selection process for high quality sperm in bovine semen using sperm separation by magnetic activation (MACS). For this, semen from 21 Nellore bulls was collected using an artificial vagina. To guarantee the presence of pathologies in the ejaculate, animals previously declassified in four consecutive spermiogram were used. Semen was analyzed in five statuses: (1) fresh semen (fresh); (2) density gradient centrifugation (DGC), percoll column; (3) non-apoptotic fraction after separation by MACS (MAC); (4) apoptotic fraction from the separation (MACPOOR); and (5) MAC followed by DGC (MACDGC). Using a computerized analysis system (CASA), motility was measured. The sperm morphology was evaluated by phase contrast, and the supravital test was completed with eosin/nigrosin staining. For DGC, 20 × 10⁶ cells were used in a gradient of 90% and 45% percoll. MACS used 10 × 10⁶ cells with 20 μL of nanoparticles attached to annexin V, and filtered through the MiniMACS magnetic separation column. Membrane integrity was assessed with SYBR-14/IP and mitochondrial potential with JC-1 by flow cytometry. Processing sperm by MACDGC, was more effective in obtaining samples with high quality sperm, verified by the total of abnormalities in the samples: 35.04 ± 2.29%, 21.50 ± 1.47%, 17.30 ± 1.10%, 30.68 ± 1.94% and 10.50 ± 1.46%, respectively for fresh, DGC, MAC, MACPOOR, and MACDGC. The subpopulation of non-apoptotic sperm had a high number of live cells (82.65%), membrane integrity (56.60%) and mitochondrial potential (83.98%) (p < 0.05). These findings suggest that this nanotechnological method, that uses nanoparticles, is efficient in the production of high-quality semen samples for assisted reproduction procedures in cattle.

• 한국통신학회논문지
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• 제29권2A호
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• pp.187-194
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• 2004

본 논문에서는 우선 순위 기반의 예약 코드 다중 접속 (P-RCMA) 프로토콜을 제안한다. P-PCMA는 기존의 RCMA 프로토콜의 음성 트래픽 성능을 개선한다. P-RCMA는 두 개의 전력 수준을 유지하고 패킷 전송을 위해 공유된 코드를 경쟁하는 시점에 트래픽의 전송 특성을 고려한다. P-RCMA는 기지국 수신 단에서 전력 세기에 따른 캡쳐 효과를 이용하여 데이터 패킷보다는 음성 예약 패킷에 우선순위를 부여한다. 성능 분석은 EPA(equilibrium point analysis) 방법과 시뮬레이션을 이용하고 성능 척도로 음성 패킷 손실 확률 (voice packet dropping probability) 과 평균 데이터 패킷 전송 지연 (average data packet transmission delay)을 사용한다.