Imminent abortion needs more serious attention since it remains a big problem in Indonesia considering its epidemiology, morbidity, mortality,?and prognosis. In fact, some cases can still be prevented.?The objective o...Imminent abortion needs more serious attention since it remains a big problem in Indonesia considering its epidemiology, morbidity, mortality,?and prognosis. In fact, some cases can still be prevented.?The objective of this study was to determine pathogenesis, diagnosis,?and prognosis of imminent abortion through the role of antioxidant vitamin C in the interaction of superoxide dismutase (SOD), interferon-γ?(IFN-γ), interleukin-4 (IL-4), vascular cells adhesion molecule-1?(VCAM-1), and decidual spiral artery resistance index (DSA RI).?This study took 10 months from March to December 2007 at Obstetrics and Gynecology Department of Medical Faculty of?Padjadjaran?University/Hasan Sadikin Hospital, Bandung. Sixty pregnant women who met the inclusion and exclusion criteria were divided into two groups with the random clinical trial method, double-blind with?repeated measurements.?Data were analyzed statistically using t test, Mann-Whitney, Rank?Spearman, Wilcoxon, t paired, and diagnostic test.?The results of this study showed that the incidence of abortion in vitamin C group was 9 cases (30%) and placebo group was 13 cases (43.3%). There was a significant difference in SOD, IFN-γ, IL-4 and VCAM-1 level between groups of women with and without abortion (p < 0.001).?There was a significant difference of SOD level between women with abortion 655.8 (163.6) U/gHb and placebo group 824.5 (106.7) U/gHb after vitamin C administration (p = 0.008). The cutoff point of SOD?was?￡992 U/gHbwhich?showed quite high sensitivity, specificity, accuracy,?and significant difference (p < 0.001). The cutoff point abortion of DSA resistance index was ≥0.55 with 45% accuracy (p = 0.002). The highest change of IL-4 level was 60.7% in vitamin C group and VCAM-1 was?-2.2% (p < 0.05) after?vitamin C administration. There was a negative correlation in SOD changes toward IL-4 changes after vitamin C administration (r =?-0.523) (p = 0.003), a positive correlation between SOD changes and IL-4 changes (0.597) (p < 0.001), a negative correlation between SOD changes and VCAM-1 changes (r =?-0.737) (p < 0.001) and a negative correlation between SOD changes and DSA RI changes (r =?-0.208) (p = 0.022). There were significant changes in the increment of IL-4 and SOD level (p < 0.001) and a decline in IFN-γ, VCAM-1 and DSA RI (p < 0.001) before and after vitamin C administration. In conclusion, there?was a correlation between the?increase of SOD level with?the?decrease of INF-γ?level and?the?increase of IL-4 level in imminent abortion after vitamin C administration. There?was a correlation between?the?increase of SOD level with?the?decrease of DSA RI and?the?decrease of VCAM-1 level in imminent abortion after vitamin C administration. In abortion, there?was?a?decrease of SOD and IL-4 level,?as well as an?increase of IFN-γ, VCAM-1, and DSA RI level.展开更多
A terrestrial relay-aided reconfigurable intelligent surface(RIS)system with decode,re-encode and forward(DRF)relaying scheme is presented where the RIS effectively contributes to both sourceto-destination and relay-t...A terrestrial relay-aided reconfigurable intelligent surface(RIS)system with decode,re-encode and forward(DRF)relaying scheme is presented where the RIS effectively contributes to both sourceto-destination and relay-to-destination signaling.While in the conventional decode and forward(DF)relaying scheme,the source signal is merely duplicated in the relay and the time intervals are equally allocated to the source and relay nodes,this paper considers DRF relaying scheme where versatile time-sharing is adopted for the source and relay nodes which can be optimized based on the relative coordinates of the involved nodes.Two protocols namely unidirectional connection(UC)and bidirectional connection(BC)are proposed based on the source awareness from the relay’s successful reception.The outage probability(OP)performance for both protocols and both DF and DRF relaying schemes is analyzed and tight approximations are obtained.The numerical results show the out-performance of the DRF over the DF relaying scheme in the both UC and BC protocols.Equipped with the obtained system OP,the system throughput is defined and the optimum system throughput is obtained by optimizing the system rate and the timesharing between the source and the relay.Analytical results are corroborated in the numerical examples.展开更多
Vehicular communication systems rely on secure vehicle-to-vehicle(V2V)communications for safety-critical information exchange.However,the presence of eavesdropping vehicles poses a significant challenge.This paper inv...Vehicular communication systems rely on secure vehicle-to-vehicle(V2V)communications for safety-critical information exchange.However,the presence of eavesdropping vehicles poses a significant challenge.This paper investigates the security of V2V communications in reconfigurable intelligent surface(RIS)-assisted vehicular communication systems with spectrum sharing.It proposes a three-stage alternating optimization(TSAO)algorithm to address the complex problem of multiple eavesdropped V2V links that reuse the spectrum already occupied by vehicle-toinfrastructure(V2I)links.To solve the mixed-integer and non-convex optimization problem due to coupled variables and complex constraints,the algorithm decomposes the original problem into three easily solvable sub-problems:RIS reflection coefficient optimization,vehicle transmission power optimization,and spectrum sharing optimization.First,the RIS reflection coefficients are optimized by using the penalty convex-concave procedure(CCP)method.Second,the optimal power points are determined in the power optimization sub-problem.Finally,the spectrum sharing optimization sub-problem is constructed as a weighted bipartite graph matching problem and solved by using the optimal matching algorithm.The TSAO algorithm not only maximizes the sum V2V secrecy rate but also ensures the quality-of-service(QoS)requirements of the V2I links.Simulation results validate the superiority of the proposed algorithm and highlight the improvement in the sum V2V secrecy rate achieved by utilizing RIS technology in vehicular communication systems with spectrum sharing.展开更多
The year 2024 marks the tenth anniversary of General Secretary Xi Jinping’s proposal for a new energy security strategy and the start of the second decade of the Belt and Road Initiative.During this year,the internat...The year 2024 marks the tenth anniversary of General Secretary Xi Jinping’s proposal for a new energy security strategy and the start of the second decade of the Belt and Road Initiative.During this year,the international situation grew increasingly complex,with intensifying rivalries among major powers and sporadic occurrences of geopolitical conflicts and localized disturbances.CNPC’s international operations focus on maintaining stability while making progress,successfully overcoming various intertwined risks and achieving new milestones in international business development.For six consecutive years,the overseas equity production has maintained an equivalent of 100 million tons.International trade has achieved stable progress,and engineering services have made new breakthroughs in market expansion,contributing new momentum to CNPC’s establishment as a world-class enterprise.展开更多
文摘Imminent abortion needs more serious attention since it remains a big problem in Indonesia considering its epidemiology, morbidity, mortality,?and prognosis. In fact, some cases can still be prevented.?The objective of this study was to determine pathogenesis, diagnosis,?and prognosis of imminent abortion through the role of antioxidant vitamin C in the interaction of superoxide dismutase (SOD), interferon-γ?(IFN-γ), interleukin-4 (IL-4), vascular cells adhesion molecule-1?(VCAM-1), and decidual spiral artery resistance index (DSA RI).?This study took 10 months from March to December 2007 at Obstetrics and Gynecology Department of Medical Faculty of?Padjadjaran?University/Hasan Sadikin Hospital, Bandung. Sixty pregnant women who met the inclusion and exclusion criteria were divided into two groups with the random clinical trial method, double-blind with?repeated measurements.?Data were analyzed statistically using t test, Mann-Whitney, Rank?Spearman, Wilcoxon, t paired, and diagnostic test.?The results of this study showed that the incidence of abortion in vitamin C group was 9 cases (30%) and placebo group was 13 cases (43.3%). There was a significant difference in SOD, IFN-γ, IL-4 and VCAM-1 level between groups of women with and without abortion (p < 0.001).?There was a significant difference of SOD level between women with abortion 655.8 (163.6) U/gHb and placebo group 824.5 (106.7) U/gHb after vitamin C administration (p = 0.008). The cutoff point of SOD?was?￡992 U/gHbwhich?showed quite high sensitivity, specificity, accuracy,?and significant difference (p < 0.001). The cutoff point abortion of DSA resistance index was ≥0.55 with 45% accuracy (p = 0.002). The highest change of IL-4 level was 60.7% in vitamin C group and VCAM-1 was?-2.2% (p < 0.05) after?vitamin C administration. There was a negative correlation in SOD changes toward IL-4 changes after vitamin C administration (r =?-0.523) (p = 0.003), a positive correlation between SOD changes and IL-4 changes (0.597) (p < 0.001), a negative correlation between SOD changes and VCAM-1 changes (r =?-0.737) (p < 0.001) and a negative correlation between SOD changes and DSA RI changes (r =?-0.208) (p = 0.022). There were significant changes in the increment of IL-4 and SOD level (p < 0.001) and a decline in IFN-γ, VCAM-1 and DSA RI (p < 0.001) before and after vitamin C administration. In conclusion, there?was a correlation between the?increase of SOD level with?the?decrease of INF-γ?level and?the?increase of IL-4 level in imminent abortion after vitamin C administration. There?was a correlation between?the?increase of SOD level with?the?decrease of DSA RI and?the?decrease of VCAM-1 level in imminent abortion after vitamin C administration. In abortion, there?was?a?decrease of SOD and IL-4 level,?as well as an?increase of IFN-γ, VCAM-1, and DSA RI level.
文摘A terrestrial relay-aided reconfigurable intelligent surface(RIS)system with decode,re-encode and forward(DRF)relaying scheme is presented where the RIS effectively contributes to both sourceto-destination and relay-to-destination signaling.While in the conventional decode and forward(DF)relaying scheme,the source signal is merely duplicated in the relay and the time intervals are equally allocated to the source and relay nodes,this paper considers DRF relaying scheme where versatile time-sharing is adopted for the source and relay nodes which can be optimized based on the relative coordinates of the involved nodes.Two protocols namely unidirectional connection(UC)and bidirectional connection(BC)are proposed based on the source awareness from the relay’s successful reception.The outage probability(OP)performance for both protocols and both DF and DRF relaying schemes is analyzed and tight approximations are obtained.The numerical results show the out-performance of the DRF over the DF relaying scheme in the both UC and BC protocols.Equipped with the obtained system OP,the system throughput is defined and the optimum system throughput is obtained by optimizing the system rate and the timesharing between the source and the relay.Analytical results are corroborated in the numerical examples.
基金National Natural Science Foundation of China(Nos.61772130,71171045 and 61901104)Innovation Program of Shanghai Municipal Education Commission,China(No.14YZ130)。
文摘Vehicular communication systems rely on secure vehicle-to-vehicle(V2V)communications for safety-critical information exchange.However,the presence of eavesdropping vehicles poses a significant challenge.This paper investigates the security of V2V communications in reconfigurable intelligent surface(RIS)-assisted vehicular communication systems with spectrum sharing.It proposes a three-stage alternating optimization(TSAO)algorithm to address the complex problem of multiple eavesdropped V2V links that reuse the spectrum already occupied by vehicle-toinfrastructure(V2I)links.To solve the mixed-integer and non-convex optimization problem due to coupled variables and complex constraints,the algorithm decomposes the original problem into three easily solvable sub-problems:RIS reflection coefficient optimization,vehicle transmission power optimization,and spectrum sharing optimization.First,the RIS reflection coefficients are optimized by using the penalty convex-concave procedure(CCP)method.Second,the optimal power points are determined in the power optimization sub-problem.Finally,the spectrum sharing optimization sub-problem is constructed as a weighted bipartite graph matching problem and solved by using the optimal matching algorithm.The TSAO algorithm not only maximizes the sum V2V secrecy rate but also ensures the quality-of-service(QoS)requirements of the V2I links.Simulation results validate the superiority of the proposed algorithm and highlight the improvement in the sum V2V secrecy rate achieved by utilizing RIS technology in vehicular communication systems with spectrum sharing.
文摘The year 2024 marks the tenth anniversary of General Secretary Xi Jinping’s proposal for a new energy security strategy and the start of the second decade of the Belt and Road Initiative.During this year,the international situation grew increasingly complex,with intensifying rivalries among major powers and sporadic occurrences of geopolitical conflicts and localized disturbances.CNPC’s international operations focus on maintaining stability while making progress,successfully overcoming various intertwined risks and achieving new milestones in international business development.For six consecutive years,the overseas equity production has maintained an equivalent of 100 million tons.International trade has achieved stable progress,and engineering services have made new breakthroughs in market expansion,contributing new momentum to CNPC’s establishment as a world-class enterprise.
