Microwave absorption properties of magnetite multi-granule nanocluster-multiwall carbon nanotube composites

An, Boo Hyun,Park, Bum Chul,Kanagaraj, Amarsingh Bhabu,Chaturvedi, Prerna,Yassi, Hamad Al,Park, Jung-Rae,Kim, Young Keun,Ryu, Jong Eun,Sanduleanu, Mihai,Choi, Daniel Sunghoi World Scientific Publishing Company 2019 Functional Materials Letters Vol.12 No.2

<P>Fe<SUB>3</SUB>O<SUB>4</SUB> multi-granule nanocluster-multiwall carbon nanotube composites for microwave absorbing applications are fabricated by the surface-engineered tape-casting method. The multi-granule nanoclusters are synthesized by a modified polyol hydrothermal method and characterized by transmission electron microscopy, X-ray diffraction and vibrating sample magnetometer. The complex permittivity and permeability of the composites with different granule size of nanoclusters are characterized in X-band range with the reflection method. The absorption peak of the composites are shifted from 11.1<TEX>$ \,$</TEX>GHz to 11.51<TEX>$ \,$</TEX>GHz as granule size increased from 18<TEX>$ \,$</TEX>nm to 35<TEX>$ \,$</TEX>nm.</P>

Effect of Carbon Addition on the Microstructural Evolution and Mechanical Properties in Hypo-Eutectic Fe-Zr(-Nb) Alloys

Kim, Tae Eung,Park, Jin Man,Sohn, Sung Woo,Kim, Do Hyang,Kim, Won Tae,Stoica, Mihai,Kü,hn, Uta,Eckert, Jü,rgen The Japan Institute of Metals 2010 MATERIALS TRANSACTIONS Vol.51 No.4

<P>The effect of carbon addition on the microstructure and mechanical properties of Fe-Zr and Fe-Zr-Nb ultrafine eutectic-dendrite composites has been investigated. Addition of carbon leads to the formation of iron solid solution strengthened by carbon interstitials and carbide particles encapsulated by α-Fe dendrites preferentially nucleated on the carbides. Consequently, the ultrafine eutectic Fe-5Zr-5Nb-0.3C (mass%) alloy exhibits high compressive strength (∼1.2 GPa) and large plastic strain (∼24%). The present study suggests another effective way to enhance the mechanical properties of Fe-based nano-eutectic alloys.</P>

전이함수모형을 이용한 약품비 지출의 예측

박미혜,임민성,성병찬,Park, MiHai,Lim, Minseong,Seong, Byeongchan 한국통계학회 2018 응용통계연구 Vol.31 No.2

본 논문에서는 약품비 지출에 대한 예측을 수행하기 위하여 시계열 모형을 도입한다. 2012년 약가 일괄인하를 반영하기 위하여 구간별 모형을 토대로, 자기회귀오차모형과 전이함수모형을 고려하였다. 자기회귀오차모형에서는 예측의 편리성을 위하여 결정적 추세만을 고려하였으며, 전이함수모형에서는 주요한 외생변수와의 교차상관성을 이용하여 약품비 지출의 인과 메커니즘을 설명하였다. 각 모형에서 약가 일괄인하 이후 수준 변화가 유의하게 나타났으며, 전이함수모형에서는 의약품 사용자 수 및 노인환자 비중 시계열 변수가 유의하게 나타났다. 자기회귀오차모형은 약가 일괄인하로 의한 약품비 수준이동에 좌우되어 비교적 낮은 예측값이 도출되었으며, 전이함수모형은 약품비 지출에 영향을 미치는 외부 설명변수의 증가 추세가 적절히 반영되어 더 높은 예측값을 보였다. 설명변수를 포함하지 않을 경우, 약품비 수준이동만을 고려한 ARIMA 모형은 약품비 지출 추세를 가장 높이 예측하였다. This study considers time series models to forecast drug expenditures in national health insurance. We adopt autoregressive error model (ARE) and transfer function model (TFM) with segmented level and trends (before and after 2012) in order to reflect drug price reduction in 2012. The ARE has only a segmented deterministic term to increase the forecasting performance, while the TFM explains a causality mechanism of drug expenditure with closely related exogenous variables. The mechanism is developed by cross-correlations of drug expenditures and exogenous variables. In both models, the level change appears significant and the number of drug users and ratio of elderly patients variables are significant in the TFM. The ARE tends to produce relatively low forecasts that have been influenced by a drug price reduction; however, the TFM does relatively high forecasts that have appropriately reflected the effects of exogenous variables. The ARIMA model without the exogenous variables produce the highest forecasts.

Comparative Effects of Bivalent, Quadrivalent, and Nonavalent Human Papillomavirus Vaccines in The Prevention of Genotype-Specific Infection: A Systematic Review and Network Meta-Analysis

Kim Jimin,Choe Young June,Park Jungeun,Cho Jahyun,Cheong Chelim,Oh Jin-Kyoung,Park Mihai,Shim Eunha,Yu Su-Yeon 대한감염학회 2024 Infection and Chemotherapy Vol.56 No.1

Background Human papillomavirus (HPV) infection is a major global disease burden and the main cause of cervical cancer. Certain HPV genotypes, with are the most common etiologic pathogens and cause a significant disease burden, are being targeted for vaccine development. However, few studies have focused on the comparative effectiveness of the bivalent HPV (2v-HPV), quadrivalent HPV (4v-HPV), and nonavalent HPV (9v-HPV) vaccines against HPV strain-specific infection. This study investigated the comparative effects of these vaccines against genotype-specific infection. Materials and Methods We conducted a pairwise and network meta-analysis of published randomized clinical trials of HPV vaccines according to sex and HPV infection status for nine HPV genotypes (HPV 6/11/16/18/31/33/45/52/58). Results Overall, 10 randomized controlled trials (12 articles) were included in this study. In the network meta-analysis, no statistically significant differences were observed in the prevention of carcinogenic HPV strains (16/18/31/33/45/52/58) between the 2v-HPV and 4v-HPV vaccines in female HPV infection–naïve populations. However, the 9v-HPV vaccine showed a significantly superior effect compared with 2v-HPV and 4v-HPV vaccines in preventing HPV 31/33/45/52/58 infections. Although 2v-HPV and 4v-HPV vaccines provided some cross-protection against HPV 31/33/45/52/58 infections, the effect was significant only on HPV 31 infection. For HPV 16 and 18, neither statistically significant nor small differences were found in the prevention of HPV infection among the 2v-HPV, 4v-HPV, and 9v-HPV vaccines. Conclusion Our study complements previous understanding of how the effect of HPV vaccines differs according to the HPV genotype. This is important because HPV genotype prevalence varies among countries. We advocate for continued efforts in vaccinating against HPV, while public health agencies should consider the difference in the vaccine effect and HPV genotype prevalence when implementing HPV vaccination in public vaccination programs. Background Human papillomavirus (HPV) infection is a major global disease burden and the main cause of cervical cancer. Certain HPV genotypes, with are the most common etiologic pathogens and cause a significant disease burden, are being targeted for vaccine development. However, few studies have focused on the comparative effectiveness of the bivalent HPV (2v-HPV), quadrivalent HPV (4v-HPV), and nonavalent HPV (9v-HPV) vaccines against HPV strain-specific infection. This study investigated the comparative effects of these vaccines against genotype-specific infection. Materials and Methods We conducted a pairwise and network meta-analysis of published randomized clinical trials of HPV vaccines according to sex and HPV infection status for nine HPV genotypes (HPV 6/11/16/18/31/33/45/52/58). Results Overall, 10 randomized controlled trials (12 articles) were included in this study. In the network meta-analysis, no statistically significant differences were observed in the prevention of carcinogenic HPV strains (16/18/31/33/45/52/58) between the 2v-HPV and 4v-HPV vaccines in female HPV infection–naïve populations. However, the 9v-HPV vaccine showed a significantly superior effect compared with 2v-HPV and 4v-HPV vaccines in preventing HPV 31/33/45/52/58 infections. Although 2v-HPV and 4v-HPV vaccines provided some cross-protection against HPV 31/33/45/52/58 infections, the effect was significant only on HPV 31 infection. For HPV 16 and 18, neither statistically significant nor small differences were found in the prevention of HPV infection among the 2v-HPV, 4v-HPV, and 9v-HPV vaccines. Conclusion Our study complements previous understanding of how the effect of HPV vaccines differs according to the HPV genotype. This is important because HPV genotype prevalence varies among countries. We advocate for continued efforts in vaccinating against HPV, while public health agencies should consider the difference in the vaccine effect and HPV genotype prevalence when implementing HPV vaccination in public vaccination programs.

SARS-CoV-2 Omicron Mutation Is Faster than the Chase: Multiple Mutations on Spike/ACE2 Interaction Residues

Kim Sinae,Nguyen Tam T.,Taitt Afeisha S.,전현정,Park Ho-Young,Kim Sung-Han,Kim Yong-Gil,Song Eun Young,Lee Youngmin,Yum Hokee,Shin Kyeong-Cheol,Choi Yang Kyu,송창선,Yeom Su Cheong,Kim Byoungguk,Netea Mihai 대한면역학회 2021 Immune Network Vol.21 No.6

Recently, a new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (B.1.1.529) Omicron variant originated from South Africa in the middle of November 2021. SARS-CoV-2 is also called coronavirus disease 2019 (COVID-19) since SARS-CoV-2 is the causative agent of COVID-19. Several studies already suggested that the SARS-CoV-2 Omicron variant would be the fastest transmissible variant compared to the previous 10 SARS-CoV-2 variants of concern, interest, and alert. Few clinical studies reported the high transmissibility of the Omicron variant but there is insufficient time to perform actual experiments to prove it, since the spread is so fast. We analyzed the SARS-CoV-2 Omicron variant, which revealed a very high rate of mutation at amino acid residues that interact with angiostatin-converting enzyme 2. The mutation rate of COVID-19 is faster than what we prepared vaccine program, antibody therapy, lockdown, and quarantine against COVID-19 so far. Thus, it is necessary to find better strategies to overcome the current crisis of COVID-19 pandemic.