This study concerns security issues of the emerging Wireless Body Sensor Network (WBSN) formed by biomedical sensors worn on or implanted in the human body for mobile healthcare appli-cations. A novel authenticated sy...This study concerns security issues of the emerging Wireless Body Sensor Network (WBSN) formed by biomedical sensors worn on or implanted in the human body for mobile healthcare appli-cations. A novel authenticated symmetric-key establishment scheme is proposed for WBSN,which fully exploits the physiological features obtained by network entities via the body channel available in WBSN but not other wireless networks. The self-defined Intrinsic Shared Secret (ISS) is used to replace the pre-deployment of secrets among network entities,which thus eliminates centralized services or au-thorities essential in existing protocols,and resolves the key transport problem in the pure symmet-ric-key cryptosystem for WBSN as well. The security properties of the proposed scheme are demon-strated in terms of its attack complexity and the types of attacks it can resist. Besides,the scheme can be implemented under a light-weight way in WBSN systems. Due to the importance of the ISS concept,the analysis on using false acceptance/false rejection method to evaluate the performance of ISS for its usage in the scheme is also demonstrated.展开更多
Time efficiency of key establishment and update is one of the major problems contributory key managements strive to address.To achieve better time efficiency in key establishment,we propose a Location-based Huffman(L-...Time efficiency of key establishment and update is one of the major problems contributory key managements strive to address.To achieve better time efficiency in key establishment,we propose a Location-based Huffman(L-Huffman) scheme.First,users are separated into several small groups to minimize communication cost when they are distributed over large networks.Second,both user's computation difference and message transmission delay are taken into consideration when Huffman coding is employed to forming the optimal key tree.Third,the combined weights in Huffman tree are located in a higher place of the key tree to reduce the variance of the average key generation time and minimize the longest key generation time.Simulations demonstrate that L-Huffman has much better performance in wide area networks and is a little better in local area network than Huffman scheme.展开更多
AIM:To characterize a culture model of rat CCA cells,which were derived from a transplantable TTA-induced CCA and designated as Chang Gung CCA(CGCCA).METHODS:The CGCCA cells were cultured at in vitro passage 12 times ...AIM:To characterize a culture model of rat CCA cells,which were derived from a transplantable TTA-induced CCA and designated as Chang Gung CCA(CGCCA).METHODS:The CGCCA cells were cultured at in vitro passage 12 times on a culture dish in DMEM medium.To measure the doubling time,103 cells were plated in a 96-well plate containing the growth medium.The cells were harvested 4 to 10 d after seeding,and astandard MTT assay was used to measure the growth.The phenotype of CACCA cell and xenograft was determined by immunohistochemical study.We also determine the chromosomal alterations of CGCCA,G-banding and spectral karyotyping studies were performed.The CGCCA cell line was transplanted into the nude mice for examining its tumorigenicity.2-Deoxy-2-(18F)fluoro-Dglucose(FDG) autoradiography was also performed to evaluate the FDG uptake of the tumor xenograft.RESULTS:The doubling time for the CGCCA cell line was 32 h.After transplantation into nude mice,FDG autoradiography showed that the tumors formed at the cell transplantation site had a latency period of 4-6 wk with high FDG uptake excluding necrosis tissue.Moreover,immunohistochemical staining revealed prominent cytoplasmic expression of c-erb-B2,CK19,c-Met,COX-Ⅱ,EGFR,MUC4,and a negative expression of K-ras.All data confirmed the phenotypic features of the CGCCA cell line coincide with the xenograft mice tumors,indicating cells containing the tumorigenicity of CCA originated from CCA.In addition,karyotypic banding analysis showed that the diploid(2n) cell status combines with ring and giant rod marker chromosomes in these clones;either both types simultaneously appeared or only one type of marker chromosome in a pair appeared in a cell.The major materials contained in the marker chromosome were primarily identified from chromosome 4.CONCLUSION:The current CGCCA cell line may be used as a non-K-ras effect CCA model and to obtain information and reveal novel pathways for CCA.Further applications regarding tumor markers or therapeutic targeting of CCA should be addressed accordingly.展开更多
Orderly execution of two critical events during the cell cycle––DNA replication and chromosome segregation––ensures the stable transmission of genetic materials. The cohesin complex physically connects sister chro...Orderly execution of two critical events during the cell cycle––DNA replication and chromosome segregation––ensures the stable transmission of genetic materials. The cohesin complex physically connects sister chromatids during DNA replication in a process termed sister chromatid cohesion. Timely establishment and dissolution of sister chromatid cohesion is a prerequisite for accurate chromosome segregation, and is tight regulated by the cell cycle machinery and cohesin-associated proteins. In this review, we discuss recent progress in the molecular understanding of sister chromatid cohesion during the mitotic cell cycle.展开更多
基金the High Technology Research and Development Program of Jiangsu Province (No.BG2005001)Hong Kong Innovation and Technology Fund (No.ITS/99/02).
文摘This study concerns security issues of the emerging Wireless Body Sensor Network (WBSN) formed by biomedical sensors worn on or implanted in the human body for mobile healthcare appli-cations. A novel authenticated symmetric-key establishment scheme is proposed for WBSN,which fully exploits the physiological features obtained by network entities via the body channel available in WBSN but not other wireless networks. The self-defined Intrinsic Shared Secret (ISS) is used to replace the pre-deployment of secrets among network entities,which thus eliminates centralized services or au-thorities essential in existing protocols,and resolves the key transport problem in the pure symmet-ric-key cryptosystem for WBSN as well. The security properties of the proposed scheme are demon-strated in terms of its attack complexity and the types of attacks it can resist. Besides,the scheme can be implemented under a light-weight way in WBSN systems. Due to the importance of the ISS concept,the analysis on using false acceptance/false rejection method to evaluate the performance of ISS for its usage in the scheme is also demonstrated.
基金Supported by National Basic Research and Development Program of China (2007CB307102)
文摘Time efficiency of key establishment and update is one of the major problems contributory key managements strive to address.To achieve better time efficiency in key establishment,we propose a Location-based Huffman(L-Huffman) scheme.First,users are separated into several small groups to minimize communication cost when they are distributed over large networks.Second,both user's computation difference and message transmission delay are taken into consideration when Huffman coding is employed to forming the optimal key tree.Third,the combined weights in Huffman tree are located in a higher place of the key tree to reduce the variance of the average key generation time and minimize the longest key generation time.Simulations demonstrate that L-Huffman has much better performance in wide area networks and is a little better in local area network than Huffman scheme.
文摘AIM:To characterize a culture model of rat CCA cells,which were derived from a transplantable TTA-induced CCA and designated as Chang Gung CCA(CGCCA).METHODS:The CGCCA cells were cultured at in vitro passage 12 times on a culture dish in DMEM medium.To measure the doubling time,103 cells were plated in a 96-well plate containing the growth medium.The cells were harvested 4 to 10 d after seeding,and astandard MTT assay was used to measure the growth.The phenotype of CACCA cell and xenograft was determined by immunohistochemical study.We also determine the chromosomal alterations of CGCCA,G-banding and spectral karyotyping studies were performed.The CGCCA cell line was transplanted into the nude mice for examining its tumorigenicity.2-Deoxy-2-(18F)fluoro-Dglucose(FDG) autoradiography was also performed to evaluate the FDG uptake of the tumor xenograft.RESULTS:The doubling time for the CGCCA cell line was 32 h.After transplantation into nude mice,FDG autoradiography showed that the tumors formed at the cell transplantation site had a latency period of 4-6 wk with high FDG uptake excluding necrosis tissue.Moreover,immunohistochemical staining revealed prominent cytoplasmic expression of c-erb-B2,CK19,c-Met,COX-Ⅱ,EGFR,MUC4,and a negative expression of K-ras.All data confirmed the phenotypic features of the CGCCA cell line coincide with the xenograft mice tumors,indicating cells containing the tumorigenicity of CCA originated from CCA.In addition,karyotypic banding analysis showed that the diploid(2n) cell status combines with ring and giant rod marker chromosomes in these clones;either both types simultaneously appeared or only one type of marker chromosome in a pair appeared in a cell.The major materials contained in the marker chromosome were primarily identified from chromosome 4.CONCLUSION:The current CGCCA cell line may be used as a non-K-ras effect CCA model and to obtain information and reveal novel pathways for CCA.Further applications regarding tumor markers or therapeutic targeting of CCA should be addressed accordingly.
基金supported by the Welch Foundation(I-1441 to H.Y.)the Clayton Foundation,and Cancer Prevention and Research Institute of Texas(RP110465-P3 and RP120717-P2 to H.Y.)
文摘Orderly execution of two critical events during the cell cycle––DNA replication and chromosome segregation––ensures the stable transmission of genetic materials. The cohesin complex physically connects sister chromatids during DNA replication in a process termed sister chromatid cohesion. Timely establishment and dissolution of sister chromatid cohesion is a prerequisite for accurate chromosome segregation, and is tight regulated by the cell cycle machinery and cohesin-associated proteins. In this review, we discuss recent progress in the molecular understanding of sister chromatid cohesion during the mitotic cell cycle.
