The Internet of things(IoT)has become a key infrastructure providing up-to-date and fresh information for policy analysis and decision-making of upper-layer applications.However,there are limited sensing and communica...The Internet of things(IoT)has become a key infrastructure providing up-to-date and fresh information for policy analysis and decision-making of upper-layer applications.However,there are limited sensing and communication resources in IoT devices,which significantly affects the timeliness and freshness of the updated status.This work proposes two schemes,namely,the generation rate control and service rate reservation schemes,to improve the overall information freshness of multiple status update streams at the receiver.Specifically,using the recently proposed Age of Information(AoI)as the metric for evaluating information freshness,we characterized the overall information freshness,i.e.,the overall average AoI at the receiver for both schemes,by considering the urgency difference of status update and streams.Both schemes for status updates and streams,respectively,were formulated as two optimization problems.We proved that both problems are convex and the optimal generation and service rates for different streams are found by the standard convex optimization algorithm.Moreover,we proposed both approximate optimal generation and approximate optimal service rate for fast deployment in heavy and light load cases.Numerical results verify the theoretical findings and accuracy of the proposed approximate solutions,guiding the design and deployment of IoT.展开更多
目的探讨、比较全酸蚀粘接剂/自酸蚀粘接剂与乳牙牙本质间粘接强度。方法选取2014年7月~2015年6月我院新鲜拔除的滞留乳磨牙40颗,按照随机数字表法分为SB2组和EO组,各20颗。SB2组采用AdperTM Single Bond 2粘接剂制成粘接试件,EO组采用A...目的探讨、比较全酸蚀粘接剂/自酸蚀粘接剂与乳牙牙本质间粘接强度。方法选取2014年7月~2015年6月我院新鲜拔除的滞留乳磨牙40颗,按照随机数字表法分为SB2组和EO组,各20颗。SB2组采用AdperTM Single Bond 2粘接剂制成粘接试件,EO组采用AdperTM Easy One粘接剂制成粘接试件。比较两组试件的微拉伸强度、断裂模式。结果SB2组微拉伸强度略高于EO组,但差异无计学意义(P>0.05);两组粘接试件均以混合断裂模式为主,差异无统计学意义(P>0.05)。结论全酸蚀粘接剂、自酸蚀粘接剂应用于乳牙牙本质均可达到理想的粘接效果,但自酸蚀粘接剂操作步骤更为简单,在儿童牙体缺损修复中值得推广。展开更多
In the present study, PC12 cells induced by 6-hydroxydopamine as a model of Parkinson's Disease, were used to investigate the protective effects of bone marrow-derived mesenchymal stem cells bone marrow-derived me...In the present study, PC12 cells induced by 6-hydroxydopamine as a model of Parkinson's Disease, were used to investigate the protective effects of bone marrow-derived mesenchymal stem cells bone marrow-derived mesenchymal stem cells against 6-hydroxydopamine-induced neurotoxicity and to verify whether the mechanism of action relates to abnormal α-synuclein accumulation in cells. Results showed that co-culture with bone marrow-derived mesenchymal stem cells enhanced PC12 cell viability and dopamine secretion in a cell dose-dependent manner. MitoLight staining was used to confirm that PC12 cells co-cultured with bone marrow-derived mesenchymal stem cells demonstrate reduced levels of cell apoptosis. Immunocytochemistry and western blot analysis found the quantity of α-synuclein accumulation was significantly reduced in PC12 cell and bone marrow-derived mesenchymal stem cell co-cultures. These results indicate that bone marrow-derived mesenchymal stem cells can attenuate 6-hydroxydopamine-induced cytotoxicity by reducing abnormal α-synuclein accumulation in PC12 cells.展开更多
Eosinophilic granulomatosis with polyangiitis(Eg PA) is a rare systemic small- and medium-sized-vessel vasculitis. The literature contains only a few reports of gastrointestinal perforation with this condition. We rep...Eosinophilic granulomatosis with polyangiitis(Eg PA) is a rare systemic small- and medium-sized-vessel vasculitis. The literature contains only a few reports of gastrointestinal perforation with this condition. We report a patient with EPgA treated with high-dose steroid who underwent emergency surgery for intestinal perforations. We performed a simple repair of the 11 perforations. Intestinal fistulas developed 8 d postoperatively; they healed well after 60 d of continuous washing and negative pressure suction. The clinical data of 14 additional patients with EgP A or Churg-Strauss syndrome complicated with gastrointestinal perforation, which were reported from 1996 to 2014, were also collected and compared. The formation of multiple perforations and fistulas following high dosage steroid administration can have a good outcome with appropriate management. Meticulous attention to abdominal symptoms and appropriate interventions can result in timely management. Corticosteroid administration remains a very important perioperative procedure for EPgA.展开更多
Reconfigurable intelligent surfaces(RISs)have the capability to change the wireless environment smartly Considering the attenuation of subchannels and crowding users involved in the wideband system,we introduce RISs i...Reconfigurable intelligent surfaces(RISs)have the capability to change the wireless environment smartly Considering the attenuation of subchannels and crowding users involved in the wideband system,we introduce RISs into the multi-user multi-input single-output(MU-MISO)system with orthogonal frequency division multiplexing(OFDM)for performance enhancement.Maximizing the minimum rate of dense users in an MU-MISO-OFDM system assisted by RIS with an approximate practical model is formulated as the joint optimization problem involving subcarrier allocation,transmit precoding(TPC)matrices at the base station,and RIS passive beamforming.A coalition-game subcarrier allocation(CSA)algorithm is proposed to solve space–frequency resource allocation on subcarriers,which reforms the interference topology among dense users.Fractional programming and convex optimization method are used to optimize the TPC matrices and the RIS passive beamforming,which improves the spectral efficiency synthetically across all subchannels in the wideband system.Simulation results indicate that the CSA algorithm provides a significant gain for dense users.Besides,the proposed joint optimization method shows the considerable advantage of the RISs in the MU-MISO-OFDM system.展开更多
基金sponsored by the National Natural Science Foundation of China under Grant 61901066,Grant 61971077sponsored by Natural Science Foundation of Chongqing,China under Grant cstc2019jcyjmsxmX0575,Grant cstc2021jcyj-msxmX0458+2 种基金in part by the Entrepreneurship and Innovation Support Plan of Chongqing for Returned Overseas Scholars under Grant cx2021092supported by the open research fund of National Mobile Communications Research Laboratory,Southeast University(No.2021D13,No.2022D06)the Industrial Internet innovation and development project(No.TC200A00M).
文摘The Internet of things(IoT)has become a key infrastructure providing up-to-date and fresh information for policy analysis and decision-making of upper-layer applications.However,there are limited sensing and communication resources in IoT devices,which significantly affects the timeliness and freshness of the updated status.This work proposes two schemes,namely,the generation rate control and service rate reservation schemes,to improve the overall information freshness of multiple status update streams at the receiver.Specifically,using the recently proposed Age of Information(AoI)as the metric for evaluating information freshness,we characterized the overall information freshness,i.e.,the overall average AoI at the receiver for both schemes,by considering the urgency difference of status update and streams.Both schemes for status updates and streams,respectively,were formulated as two optimization problems.We proved that both problems are convex and the optimal generation and service rates for different streams are found by the standard convex optimization algorithm.Moreover,we proposed both approximate optimal generation and approximate optimal service rate for fast deployment in heavy and light load cases.Numerical results verify the theoretical findings and accuracy of the proposed approximate solutions,guiding the design and deployment of IoT.
文摘目的探讨、比较全酸蚀粘接剂/自酸蚀粘接剂与乳牙牙本质间粘接强度。方法选取2014年7月~2015年6月我院新鲜拔除的滞留乳磨牙40颗,按照随机数字表法分为SB2组和EO组,各20颗。SB2组采用AdperTM Single Bond 2粘接剂制成粘接试件,EO组采用AdperTM Easy One粘接剂制成粘接试件。比较两组试件的微拉伸强度、断裂模式。结果SB2组微拉伸强度略高于EO组,但差异无计学意义(P>0.05);两组粘接试件均以混合断裂模式为主,差异无统计学意义(P>0.05)。结论全酸蚀粘接剂、自酸蚀粘接剂应用于乳牙牙本质均可达到理想的粘接效果,但自酸蚀粘接剂操作步骤更为简单,在儿童牙体缺损修复中值得推广。
基金supported by the Science and Technology Development Foundation of Beijing Science and Technology Commission, No. Z101107052210004
文摘In the present study, PC12 cells induced by 6-hydroxydopamine as a model of Parkinson's Disease, were used to investigate the protective effects of bone marrow-derived mesenchymal stem cells bone marrow-derived mesenchymal stem cells against 6-hydroxydopamine-induced neurotoxicity and to verify whether the mechanism of action relates to abnormal α-synuclein accumulation in cells. Results showed that co-culture with bone marrow-derived mesenchymal stem cells enhanced PC12 cell viability and dopamine secretion in a cell dose-dependent manner. MitoLight staining was used to confirm that PC12 cells co-cultured with bone marrow-derived mesenchymal stem cells demonstrate reduced levels of cell apoptosis. Immunocytochemistry and western blot analysis found the quantity of α-synuclein accumulation was significantly reduced in PC12 cell and bone marrow-derived mesenchymal stem cell co-cultures. These results indicate that bone marrow-derived mesenchymal stem cells can attenuate 6-hydroxydopamine-induced cytotoxicity by reducing abnormal α-synuclein accumulation in PC12 cells.
文摘Eosinophilic granulomatosis with polyangiitis(Eg PA) is a rare systemic small- and medium-sized-vessel vasculitis. The literature contains only a few reports of gastrointestinal perforation with this condition. We report a patient with EPgA treated with high-dose steroid who underwent emergency surgery for intestinal perforations. We performed a simple repair of the 11 perforations. Intestinal fistulas developed 8 d postoperatively; they healed well after 60 d of continuous washing and negative pressure suction. The clinical data of 14 additional patients with EgP A or Churg-Strauss syndrome complicated with gastrointestinal perforation, which were reported from 1996 to 2014, were also collected and compared. The formation of multiple perforations and fistulas following high dosage steroid administration can have a good outcome with appropriate management. Meticulous attention to abdominal symptoms and appropriate interventions can result in timely management. Corticosteroid administration remains a very important perioperative procedure for EPgA.
基金Project supported by the Graduate Research and Innovation Foundation of Chongqing,China(No.CYB23050)the National Natural Science Foundation of China(Nos.62271092,62001074)+4 种基金the Fundamental Research Funds for the Central Universities,China(No.2023CDJXY-037)the China Postdoctoral Science Foundation(No.2022M710534)the Natural Science Foundation of Chongqing,China(Nos.CSTB2023NSCQMSX0933,CSTB2022NSCQMSX0327)the Open Fund of the Shaanxi Key Laboratory of Information Communication Network and Security,China(No.ICNS202201)the Opening Project of the Guangxi Wireless Broadband Communication and Signal Processing Key Laboratory,China(No.GXKL06230206)。
文摘Reconfigurable intelligent surfaces(RISs)have the capability to change the wireless environment smartly Considering the attenuation of subchannels and crowding users involved in the wideband system,we introduce RISs into the multi-user multi-input single-output(MU-MISO)system with orthogonal frequency division multiplexing(OFDM)for performance enhancement.Maximizing the minimum rate of dense users in an MU-MISO-OFDM system assisted by RIS with an approximate practical model is formulated as the joint optimization problem involving subcarrier allocation,transmit precoding(TPC)matrices at the base station,and RIS passive beamforming.A coalition-game subcarrier allocation(CSA)algorithm is proposed to solve space–frequency resource allocation on subcarriers,which reforms the interference topology among dense users.Fractional programming and convex optimization method are used to optimize the TPC matrices and the RIS passive beamforming,which improves the spectral efficiency synthetically across all subchannels in the wideband system.Simulation results indicate that the CSA algorithm provides a significant gain for dense users.Besides,the proposed joint optimization method shows the considerable advantage of the RISs in the MU-MISO-OFDM system.
