Peroxisome proliferator-activated receptors （PPAR） belong to the nuclear hormone receptor superfamily of ligand-dependent transcription factors. Recent results have shown that agonists of PPARy, such as troglitazone...Peroxisome proliferator-activated receptors （PPAR） belong to the nuclear hormone receptor superfamily of ligand-dependent transcription factors. Recent results have shown that agonists of PPARy, such as troglitazone （TGZ）, can inhibit cell proliferation and promote cell differentiation independent of PPARy. In the present study, we provide evidence that TGZ may bind directly to EGFR and trigger its signaling and internalization independent of PPARγ. Detailed studies revealed that prolonged incubation with TGZ effectively attenuated EGFR signaling by targeting the receptor to the endo-lysosomal degradation machinery. Although the extracellular signal-regulated kinasesignaling pathway was transiently activated by TGZ in EGFR overexpressing cancer cells, inhibition of EGF-induced Akt phosphorylation most likely accounted for the growth arrest of tumor cells caused by TGZ at pharmacologically achievable concentrations. Therefore, we have provided a new line of evidence indicating that TGZ inhibits cell pro- liferation by promoting EGFR degradation and attenuating Akt phosphorylation.展开更多
The stability and ductility of four buckling-restrained braces (BRBs) with brace joints were studied. The load-carrying element of BRB was fabricated with steel (Chinese Q235), and a layer of colloidal silica sheet (0...The stability and ductility of four buckling-restrained braces (BRBs) with brace joints were studied. The load-carrying element of BRB was fabricated with steel (Chinese Q235), and a layer of colloidal silica sheet (0.5 mm in thickness) or four layers of plastic film (0.2 mm in thickness) were used as unbonding materials to provide space to prevent the buckling of inner core in higher modes and facilitate its lateral expansion in case of compression. Based on the equation of BRBs with brace joints of different restrained stiffnesses, the buckling load is calculated considering the initial geometric imperfections and residual stress, and the theoretical values agree well with the experiment results. It is concluded that the buckling load and ductility of BRBs are influenced greatly by the restrained stiffness of brace joints. If the restrained stiffness is deficient, the unstrained segment of BRBs with less stiffness will buckle firstly. As a result, the ultimate load of BRBs decreases, and the maximum compression load is reduced to about 65% of the maximum tension load; the stiffness also degenerates, and there is a long decreasing stage on the back-bone curve in compression phase; the ductility decreases, i.e., the ultimate tension ductility and ultimate compression ductility are approximately 15 and 1.3 respectively, and the cumulative plastic ductility is only approximately 200. If the restrained stiffness of joint is large enough, the stability will be improved as follows: the yielding strength and ultimate strength of BRBs are nearly the same, and there is an obvious strain intensification in both tension and compression phases; the ductility of brace also increases obviously, i.e., the ultimate tension ductility and ultimate compression ductility are both approximately 14, and the cumulative plastic ductility reaches 782.展开更多
AIM： To investigate preoperative factors associated with poor shore-term outcome after resection for multi- nodular hepatocellular carcinoma （HCC） and to assess the contraindication of patients for surgery, METHODS...AIM： To investigate preoperative factors associated with poor shore-term outcome after resection for multi- nodular hepatocellular carcinoma （HCC） and to assess the contraindication of patients for surgery, METHODS： We retrospectively analyzed 162 multi- nodular HCC patients with Child-Pugh A liver function who underwent surgical resection. The prognostic significance of preoperative factors was investigated by univariate analysis using the log-rank test and by multivariate analysis using the Cox proportional hazards model. Each independent risk factor was then assigned points to construct a scoring model to evaluate the in- dication for surgical intervention. A receiver operating characteristics （ROC） curve was constructed to assess the predictive ability of this system.RESULTS： The median overall survival was 38.3 mo （range： 3-80 too）, while the median disease-free sur- vival was 18.6 mo （range： 1-79 too）. The 1-year mor- tality was 14%. Independent prognostic risk factors of 1-year death included prealburnin 〈 170 rng/L [hazard ratio （HR）： 5.531, P 〈 0.001], alkaline phosphatase 〉 129 U/L （HR： 3.252, P = 0.005）, α fetoprotein 〉 20 μg/L （HR： 7.477, P = 0.011）, total tumor size 〉 8 cm （HR： 10.543; P 〈 0.001）, platelet count 〈 100×109/L （HR： 9.937, P 〈 0.001）, and y-glutamyl transpeptidase 〉 64 U/L （HR： 3.791, P 〈 0.001）. The scoring model had a strong ability to predict 1-year survival （area under ROC： 0.925, P 〈 0.001）. Patients with a score ≥5 had significantly poorer short-term outcome than those with a score 〈 5 （1-year mortality： 62% vs 5%, P 〈 0.001; 1-year recurrence rate： 86% vs 33%, P 〈 0.001）. Patients with score ≥5 had greater possibility of microvascular invasion （P 〈 0.001）, poor tumor dif- ferentiation （P = 0.003）, liver cirrhosis with small nod- ules （P 〈 0.001）, and intraoperative blood transfusion （P = 0.010）. CONCLUSION： A composite preoperative scoring model can be used as an indication of prognosis of HCC patients after surgical resection. Resection should be considered with caution in patients with a score ≥5, which indicates a contraindication for surgery.展开更多
Network losses allocation is one of the major problems in the market environment. The quadric function of the injected nodal power is used in this paper as a representation for network losses, which are allocated fair...Network losses allocation is one of the major problems in the market environment. The quadric function of the injected nodal power is used in this paper as a representation for network losses, which are allocated fairly using the called market equilibrium principle while the bidding curves are corrected. The power market equilibrium is simulated as three different models that can be solved simply by the optimal power flow algorithm combining the generation scheduling problem with network losses allocation. The case study is made at an IEEE-30 nodes system and a perfect result is proved in this paper.展开更多
Wireless Sensor Networks (WSNs) are being deployed for a wide variety of applications and the security problems of them have received considerable attention. Considering the limitations of power, computation capabilit...Wireless Sensor Networks (WSNs) are being deployed for a wide variety of applications and the security problems of them have received considerable attention. Considering the limitations of power, computation capability and storage resources, this paper proposed an efficient defense against collusion scheme based on elliptic curve cryptography for wireless sensor networks in order to solve the problems that sensor node-key leaking and adversaries make compromised nodes as their collusions to launch new attack. In the proposed scheme, the group-key distribution strategy is employed to compute the private key of each sensor node, and the encryption and decryption algorithms are constructed based on Elliptic Curve Cryptography (ECC). The command center (node) only needs to broadcast a controlling header with three group elements, and the authorized sensor node can correctly recover the session key and use it to decrypt the broadcasting message. Analysis and proof of the proposed scheme's efficiency and security show that the proposed scheme can resist the k-collusion attack efficiently.展开更多
文摘Peroxisome proliferator-activated receptors （PPAR） belong to the nuclear hormone receptor superfamily of ligand-dependent transcription factors. Recent results have shown that agonists of PPARy, such as troglitazone （TGZ）, can inhibit cell proliferation and promote cell differentiation independent of PPARy. In the present study, we provide evidence that TGZ may bind directly to EGFR and trigger its signaling and internalization independent of PPARγ. Detailed studies revealed that prolonged incubation with TGZ effectively attenuated EGFR signaling by targeting the receptor to the endo-lysosomal degradation machinery. Although the extracellular signal-regulated kinasesignaling pathway was transiently activated by TGZ in EGFR overexpressing cancer cells, inhibition of EGF-induced Akt phosphorylation most likely accounted for the growth arrest of tumor cells caused by TGZ at pharmacologically achievable concentrations. Therefore, we have provided a new line of evidence indicating that TGZ inhibits cell pro- liferation by promoting EGFR degradation and attenuating Akt phosphorylation.
基金Supported by the "Eleventh Five-Year Plan" for Science and Technology Research of China (No. 2006BAJ01B02-02-03)Natural Science Foundation of Heilongjiang Province (No. ZJG0701)+1 种基金National Natural Science Foundation of China (No. 90715021, No. 50678057, No. 50978080)Natural Scientific Research Innovation Foundation of Harbin Institute of Technology (No. HIT. NSRIF. 2009)
文摘The stability and ductility of four buckling-restrained braces (BRBs) with brace joints were studied. The load-carrying element of BRB was fabricated with steel (Chinese Q235), and a layer of colloidal silica sheet (0.5 mm in thickness) or four layers of plastic film (0.2 mm in thickness) were used as unbonding materials to provide space to prevent the buckling of inner core in higher modes and facilitate its lateral expansion in case of compression. Based on the equation of BRBs with brace joints of different restrained stiffnesses, the buckling load is calculated considering the initial geometric imperfections and residual stress, and the theoretical values agree well with the experiment results. It is concluded that the buckling load and ductility of BRBs are influenced greatly by the restrained stiffness of brace joints. If the restrained stiffness is deficient, the unstrained segment of BRBs with less stiffness will buckle firstly. As a result, the ultimate load of BRBs decreases, and the maximum compression load is reduced to about 65% of the maximum tension load; the stiffness also degenerates, and there is a long decreasing stage on the back-bone curve in compression phase; the ductility decreases, i.e., the ultimate tension ductility and ultimate compression ductility are approximately 15 and 1.3 respectively, and the cumulative plastic ductility is only approximately 200. If the restrained stiffness of joint is large enough, the stability will be improved as follows: the yielding strength and ultimate strength of BRBs are nearly the same, and there is an obvious strain intensification in both tension and compression phases; the ductility of brace also increases obviously, i.e., the ultimate tension ductility and ultimate compression ductility are both approximately 14, and the cumulative plastic ductility reaches 782.
文摘AIM： To investigate preoperative factors associated with poor shore-term outcome after resection for multi- nodular hepatocellular carcinoma （HCC） and to assess the contraindication of patients for surgery, METHODS： We retrospectively analyzed 162 multi- nodular HCC patients with Child-Pugh A liver function who underwent surgical resection. The prognostic significance of preoperative factors was investigated by univariate analysis using the log-rank test and by multivariate analysis using the Cox proportional hazards model. Each independent risk factor was then assigned points to construct a scoring model to evaluate the in- dication for surgical intervention. A receiver operating characteristics （ROC） curve was constructed to assess the predictive ability of this system.RESULTS： The median overall survival was 38.3 mo （range： 3-80 too）, while the median disease-free sur- vival was 18.6 mo （range： 1-79 too）. The 1-year mor- tality was 14%. Independent prognostic risk factors of 1-year death included prealburnin 〈 170 rng/L [hazard ratio （HR）： 5.531, P 〈 0.001], alkaline phosphatase 〉 129 U/L （HR： 3.252, P = 0.005）, α fetoprotein 〉 20 μg/L （HR： 7.477, P = 0.011）, total tumor size 〉 8 cm （HR： 10.543; P 〈 0.001）, platelet count 〈 100×109/L （HR： 9.937, P 〈 0.001）, and y-glutamyl transpeptidase 〉 64 U/L （HR： 3.791, P 〈 0.001）. The scoring model had a strong ability to predict 1-year survival （area under ROC： 0.925, P 〈 0.001）. Patients with a score ≥5 had significantly poorer short-term outcome than those with a score 〈 5 （1-year mortality： 62% vs 5%, P 〈 0.001; 1-year recurrence rate： 86% vs 33%, P 〈 0.001）. Patients with score ≥5 had greater possibility of microvascular invasion （P 〈 0.001）, poor tumor dif- ferentiation （P = 0.003）, liver cirrhosis with small nod- ules （P 〈 0.001）, and intraoperative blood transfusion （P = 0.010）. CONCLUSION： A composite preoperative scoring model can be used as an indication of prognosis of HCC patients after surgical resection. Resection should be considered with caution in patients with a score ≥5, which indicates a contraindication for surgery.
文摘Network losses allocation is one of the major problems in the market environment. The quadric function of the injected nodal power is used in this paper as a representation for network losses, which are allocated fairly using the called market equilibrium principle while the bidding curves are corrected. The power market equilibrium is simulated as three different models that can be solved simply by the optimal power flow algorithm combining the generation scheduling problem with network losses allocation. The case study is made at an IEEE-30 nodes system and a perfect result is proved in this paper.
基金Supported by the Six Great Talent Peak Plan of Jiangsu Province (No.06-E-044)the "Qinlan Project" Plan of Jiangsu Province 2006
文摘Wireless Sensor Networks (WSNs) are being deployed for a wide variety of applications and the security problems of them have received considerable attention. Considering the limitations of power, computation capability and storage resources, this paper proposed an efficient defense against collusion scheme based on elliptic curve cryptography for wireless sensor networks in order to solve the problems that sensor node-key leaking and adversaries make compromised nodes as their collusions to launch new attack. In the proposed scheme, the group-key distribution strategy is employed to compute the private key of each sensor node, and the encryption and decryption algorithms are constructed based on Elliptic Curve Cryptography (ECC). The command center (node) only needs to broadcast a controlling header with three group elements, and the authorized sensor node can correctly recover the session key and use it to decrypt the broadcasting message. Analysis and proof of the proposed scheme's efficiency and security show that the proposed scheme can resist the k-collusion attack efficiently.
