Experimental Studies on Progressive Collapse Behavior of RC Frame Structures: Advances and Future Needs

Wei?Jian Yi,Fan Yi,Yun Zhou 한국콘크리트학회 2021 International Journal of Concrete Structures and M Vol.15 No.4

In the recent two decades, the progressive collapse of reinforced concrete (RC) frame structures attracted unprecedented research interests in the structural engineering community. Experiments are regarded as an essential method in this field since actual cases can barely provide sufficient and effective data to support rigorous research. In this paper, prevailing experimental assumptions and configurations among over 100 series of experiments are quantitatively revealed by a bibliometric collection based on systematic search in an academic database. Since numerous experiments have been reported on the progressive collapse of RC frame structures, this paper subsequently presents a state-of-the-art review summarizing both experimental consensuses and controversies constituted by three main aspects: (a) static mechanisms, (b) dynamic behavior, and (c) threat-dependent research. The significance of secondary mechanisms, existing problems of dynamic effects, and potential flaws of the threat-independent assumption are discussed in detail with experimental findings. Future needs are emphasized on research targets, correlations between experiments and design, dynamic effects, threat-dependent issues, and retrofitting. These recommendations might help researchers or designers realize a more reliable and realistic progressive collapse design of RC frame structures in the future.

DNA methylation and mRNA expression of COL6A3 in antler mesenchyme of female and male reindeer

Jian‑Cheng Zhai,Ruo‑Bing Han,Sheng‑Nan Wang,Qiang‑Hui Wang,Yan‑Ling Xia,Wei‑Shi Liu,Ya‑Jie Yin,He‑Ping Li 한국유전학회 2019 Genes & Genomics Vol.41 No.9

Backgroud Reindeer is the only deer species that both male and female produce antlers, which provides a particularly interesting case in studying the differences between antlers of the two sexes. Alpha 3(VI) Collagen Gene (COL6A3), forms a microfibrillar network associated with the structural integrity and biomechanical properties, has been found to be one of the differentially expressed genes in antler mesenchyme of female and male reindeer. Objective and Methods The promoter sequence of reindeer COL6A3 gene was obtained using the cloning technology and analyzed by the bioinformatics methods. Bisulfite sequencing PCR (BSP) was used to detect the methylation status of the COL6A3 promoter in reindeer antler mesenchyme. Real-time quantitative PCR was used to detect COL6A3 expression in the antler mesenchyme of female and male reindeer. Results Sequence analysis revealed that the reindeer COL6A3 partial promoter sequence was 983 bp including the possible promoter region at + 105 bp to + 155 bp. Homology and phylogenetic analysis indicated that the COL6A3 promoter of reindeer had the closest genetic distance with Bos taurus, Capra hircus and Ovis aries. BSP results indicated that the methylation level of COL6A3 promoter in the female reindeer antler mesenchyme was significantly higher than in the male. Correlating with increased methylation status, we also found that COL6A3 mRNA expression in female reindeer antler mesenchyme was significantly lower than in the male. Conclusion The higher methylation level of the COL6A3 gene in female reindeer antler mesenchyme coincides with decreased COL6A3 mRNA expression, thereby affecting the transposon silencing mechanism and possibly contributing to apparent differences of antlers in female and male reindeer.

Gene microarray analysis revealed a potential crucial gene RACK1 in oral squamous cell carcinoma (OSCC)

Jian-Wei Zheng,Yinshen Yang,Shujuan Yang,Wei Zhou,Hongtian Qiu,Xiaoping Li,Qiuyun Cai,Ting Li,Gang Luo 한국통합생물학회 2018 Animal cells and systems Vol.22 No.2

Oral squamous cell carcinoma (OSCC) is the sixth most common cancer worldwide, which appears as a consequence of multiple molecular genetic events in various chromosomes and genes. In order to unveil the possible mechanisms underlying OSCC tumorigenesis, the OSCC-related gene expression variance and the gene interaction network should be further investigated. Herein, we conducted the NimbleGen Human Gene Expression Microarray to analyze expression heterogeneity between OSCC primary tumor tissue and its adjacent normal tissue from two patients. A total number of 7872 out of 32,448 detected genes are differentially expressed in OSCC. Gene ontology (GO) analysis demonstrated that these differentially expressed transcripts were critical in a series of metabolic processes, cancer-related signal pathways, and biological regulations. KEGG signaling pathway enrichment suggested a number of pathways (metabolic process and immune response) which are frequently enrolled during cancer progression. 15 most differential regulated genes between OSCC tumor and non-tumor were confirmed by quantitative reverse transcription polymerase chain reaction (qRT-PCR). Furthermore, the interaction network analysis of these confirmed genes by STRING database showed the two subunits of RACK1 had direct interaction with 14 differential proteins. This bioinformatics research lends support about the critical role of RACK1 which functions as a key node protein driving OSCC development.

A New Ambiguity Elimination Method for BSS Block Signals in Time Domain

Wei Zhao,Fengshan Wang,Yuehong Shen,Yuanyuan Wu,Zhigang Yuan,Pengcheng Xu,Pengcheng Xu,Yimin Wei,Wei Jian 보안공학연구지원센터 2015 International Journal of Signal Processing, Image Vol.8 No.11

This paper deals with the ambiguity problem of blind source separation (BSS) in the case where continuously received mixture signals are split in time and processed block by block. Due to the inherent permutation and scaling ambiguities of BSS, tying the separated components at each adjacent time blocks doesn’t recover the original source signals correctly in general. Inspired by the Permutation Method of reconstructing source signal blocks in time domain, a new ambiguity elimination approach is proposed in this paper. This method aims to concatenate the separated components in adjacent blocks by artificially setting contrast blocks for each adjacent time blocks. The core idea of this method is to utilize the associativity between components recovered from contrast blocks and corresponding adjacent blocks. Compared with Permutation Method, the main advantage of this new method consists in the fact that it is much more efficient in terms of separation quality and computational speed. Besides, a tradeoff can be adjusted between separation quality and computational speed by choosing different length of contrast blocks. Real-life experiments are performed to validate the performance of this method on the wireless communication system with two transmitting and receiving antennas.

Synthesis of Novel D-Glucose-derived Benzyl and Alkyl 1,2,3-Triazoles as Potential Antifungal and Antibacterial Agents

Wei, Jin-Jian,Jin, Lei,Wan, Kun,Zhou, Cheng-He Korean Chemical Society 2011 Bulletin of the Korean Chemical Society Vol.32 No.1

A series of novel glucose derived benzyl and alkyl 1,2,3-triazoles and their hydrochlorides have been synthesized via Cu(I)-catalyzed 1,3-dipolar cycloaddition. All the new compounds were characterized by MS, IR and NMR spectra. The DEPT, APT, $^1H$-$^1H$ and $^1H-^{13}C$ 2D NMR spectra for some compounds were also recorded. These compounds were evaluated for their in vitro antibacterial activities against Staphylococcus aureus ATCC 29213, Bacillus subtilis, Bacillus proteus, Pseudomonas aeruginosa, Escherichia coli ATCC 25922, and antifungal activities against Candida albicans and Aspergillus fumigatus. The bioactive data revealed that (3R,4S,5S,6S)-2-(hydroxymethyl)-6-methoxy-4,5-bis((1-octyl-1H-1,2,3-triazol-4-yl)methoxy)-tetrahydro-2H-pyran-3-ol 8a exhibited excellent antifungal activity against A. fumigatus with an MIC value of 0.055 mM compared to Fluconazole. It also showed broad inhibitory efficacy against tested bacterial strains with MIC values ranging from 0.049 mM to 0.39 mM.

Anti-HIV-1 Activity of Lignans from the Fruits of Schisandra rubriflora

Wei-Lie Xiao,Rui-Rui Wang,Wei Zhao,Ren-Rong Tian,Shan-Zhai Shang,Liu-Meng Yang,Jian-Hong Yang,Jian-Xin Pu,Yong-Tang Zheng,Han-Dong Sun 대한약학회 2010 Archives of Pharmacal Research Vol.33 No.5

This study investigated the 70% aqueous acetone extract of the fruits of Schisandra rubriflora which led to the isolation of eight lignans, including a new isolate, rubrisandrin C (1), and seven known lignans (2-8) . The structure of 1 was established by extensive 1D and 2D NMR spectroscopy and its absolute stereochemistry was determined by CD spectrum. Compounds 1-5 and 7-8 were evaluated for their anti-HIV-1 activity that showed inhibitory activity on HIV-1IIIB induced syncytium formation with EC50 values in the range of 2.26~20.4 μg/mL. Compounds 1 and 7 exerted their obvious protection of HIV-1IIIB inducted MT-4 host cells lytic effects with a selectivity index of 15.4 and 24.6, respectively.

NUMERICAL STUDY ABOUT AIRCRAFT-SKIN INFRARED CHARACTERISTICS AND ITS SUPPRESSION EFFECTIVENESS

Jian-Wei Lu,Qiang Wang,Oh Joon Kwon 한국전산유체공학회 2010 한국전산유체공학회 학술대회논문집 Vol.2010 No.11

In supersonic cruise the temperature of aircraft skin arises higher than 300K due to aerodynamic heating. Then aircraft-skin infrared suppression of minimizing the radiation contrast of the aircraft skin from its background becomes a crucial survival technology. In the present study, a technique for the effectiveness evaluation of infrared suppression of aircraft skin is proposed. For this purpose, a synthetic model to simulate the overall numerical procedure has been developed. The thermal status on the aircraft skin was obtained by a computational fluid dynamics(CFD) method. Then, an infrared (IR) signature model for complex aircraft geometries was proposed with the reverse Monte Carlo(RMC) technique. The infrared contrast was adopted as the performance indicators for the evaluation of aircraft infrared suppression. The influence of aircraft skin radiation related factors, such as the aircraft-skin emissivity and the aircraft-skin temperature distribution, on the infrared contrast was also studied theoretically. The method has been applied to clarify the contribution of each aircraft components to the IR suppression of the overall infrared radiation. The results show that aircraft-skin temperature control and emissivity control are an effective approach to reduce the infranred radiation and to achieve lower detection. The results can be used as a practical guide line for designing future stealth aircrafts.

원상도(元上都)의 조사와 건축유적의 고고학 연구

Wei Jian 국립문화재연구원 2012 헤리티지:역사와 과학 Vol.45 No.3

The Shàngdu site in the Yuan Dynasty of China, a capital city located in the northern steppe area characterised by the nomadic life, has received great attentions from a number of travellers, historians and archaeologists. Several famous European travellers described vividly the city structure and civil life of Shàngdu from the Yuan Dynasty onwards. Since the begging of the modern era, a number of foreign expeditionists and historians explored Shàngdu and published research reports. From the 20th century, mainly Chinese and Japanese historians and archaeologists carried out the relatively detailed historical researches and archaeological surveys to the Shàngdu site; and published books, articles and excavation reports. More detailed and scientific archaeological investigations, mappings and excavations have been conducted since 1990s. This paper aims to progress basic discussion to the city structures of the Shàngdu site based on the previously conducted researches by expeditionists, geographers and archaeologists and the full scale investigations, which have been carried out since the late 20th century. 원(元) 상도(上都) 유적은 유목생활의 특색을 지닌 초원의 도성(都城)으로 역대로 많은 여행가와 역사학자, 고고학자들의 주 목을 받아왔다. 원조(元朝)부터 몇몇 유럽의 저명한 여행가들은 원 상도를 생동감 있게 묘사하였고, 근대에는 수많은 외국 여행 가와 역사학자들이 원 상도를 현지답사하고 여행기와 연구보고서를 발표하였다. 20세기에 들어와서는 주로 중국, 일본의 역사 학자와 고고학자들이 원 상도에 대해 비교적 전면적인 역사 고증과 고고학 조사를 진행하였고 아울러 논저와 고고학 조사보고 서를 발표하였다. 1990년대에 들어와서 보다 더 전면적이고 과학적인 고고학 조사와 실측 및 발굴 작업이 진행되었다. 본문은 상술한 여행가, 지리학자, 고고학자들의 원상도에 대한 조사와 기록을 회고하면서 20세기 말에 이루어진 원상도의 조사와 발 굴 자료를 통해 원상도의 건축유적에 대한 기초적인 토론을 진행하고자 한다.

Chemical Constituents from the Aerial Parts of Isodon coetsa and their Cytotoxicity

Wei Zhao,Jian Xin Pu,Xue Du,Yong Zhao,Fei He,Hai Bo Zhang,Yong Bo Xue,Wei Lie Xiao,Han Dong Sun,Ying Li Wu,Guo Qiang Chen 대한약학회 2011 Archives of Pharmacal Research Vol.34 No.12

Three new compounds (1-3), including a neolignan, a triterpenoid, and a diterpenoid, together with twenty known compounds (4-23), were isolated from the aerial parts of Isodon coetsa. Their structures and relative configurations were elucidated on the basis of spectroscopic data. Compounds 1, 3, 5-9, 11-13, 16-17, and 19-23 were evaluated for their cytotoxicity against HT-29, BEL-7402, and SK-OV-3 human tumor cell lines. Compound 7 showed significant inhibitory effects on all three types of cells, with IC50 values of 2.52, 3.06, 2.14 μM, respectively.

집파리유충 hemolymph 중신형의 anti-fungal peptides의 분리정제

Jian-Wei Wu,Li-juan Gu,Xiao-Qing Su,성창근 한국생명과학회 2006 생명과학회지 Vol.16 No.3

To isolate and purify anti-fungal active substances from immunized housefly (Musca domestica), low dose of Candida albicans was injected into the larvae of the housefly to induce the appearance of potent anti-fungal active substances in the hemolymph. This purification work was performed by the routine isolation and purification processes of protein, namely, solid phase extraction (SPE), SDS-PAGE electrophoresis, HPLC purification. Three 4~16 kDa peptides which exhibited antifungal activity against Candida albican and other fungi were isolated from induced hemolymph. Consequently, further anti-fungal activity study showed that these three peptides were different either in molecular weight or in anti-fungal activity. All isolated substances were proved to be active and resistant to high-temperature. It was deduced that these peptides isolated from induced housefly were novel members of the insect defensin family and they were inducible. 유도된 집파리유통 hemolymph중에서 Candida albicans의 3가지 anti-fungal peptides를 분리하였다. 3개 anti-fungal peptides는 분자량이 4-16 kDa 사이의 분명한 구별이 있을 뿐만 아니라, 각 peptide는 anti-fungal peptides 작용이 있었다. 이들 peptide의 공통 특징은 모두 열을 받은 뒤 활성이 변하지 않는 비교적 강한 내열성을 보여주었다.