Reconfigurable intelligent surface(RIS)is emerged as a promising technique to solve the challenges faced by future wireless communication networks.Although the most commonly used electrically-controlled RISs can achie...Reconfigurable intelligent surface(RIS)is emerged as a promising technique to solve the challenges faced by future wireless communication networks.Although the most commonly used electrically-controlled RISs can achieve millisecond-scale speed of dynamic switch,they have a large number of microwave circuit elements(such as PIN diodes or varactors)which will bring non-negligible insertion loss,and the complicity of the bias network to electrically addressing each element will increase with the expansion of the RIS aperture.Aiming at further reducing the fabrication cost and power consumption,herein an electromechanical RIS used for sub-6G wireless communication is proposed.The electromechanical RIS is designed with a passive metasurface and step-motor driver modules,providing simultaneous high-efficiency reflection(over 80%)and continuous reflection phase coverage of 360.Through electromechanical control,the RIS system can realize different reflective wavefront shaping,and has been employed in the indoor sub-6G wireless environment demonstrating a maximum signal improvement of 8.3 dB.The proposed electromechanical RIS is particularly useful for wireless signal enhancement in static blind area,and has the obvious advantage of not requiring continuous power supply after the RIS being regulated.Therefore,it greatly reduces the overall cost and power consumption which may have potentials in indoor application scenarios for improving wireless communication performance.展开更多
The joint adoption of sub-6GHz and millimeter wave(mmWave)technology can prevent the blind spots of coverage,enabling comprehensive coverage while realizing high-speed communication rate.According to the sensitivity o...The joint adoption of sub-6GHz and millimeter wave(mmWave)technology can prevent the blind spots of coverage,enabling comprehensive coverage while realizing high-speed communication rate.According to the sensitivity of mmWave,base stations should be more densely deployed,which is not well described by existing Poisson hole process(PHP)and the Poisson point process(PPP)models.This paper establishes a sub-6GHz and mmWave hybrid heterogeneous cellular network based on the modified Poisson hole process(MPHP).In our proposed model,the sub-6GHz base stations follow the PPP,and the mmWave base stations(MBSs)follow MPHP distribution.The expressions of the coverage probability are derived by using the interference calculation method of integrating the nearest sector exclusion area.Our theoretical analysis has been verified through simulation results,suggesting that the increase in the cell radius decreases the coverage probability of signal-to-interference-plus-noise ratio(SINR),whereas the increase in the sector parameter has the opposite effect.The variation of sub-6GHz base stations(SBSs)density imposes more significant impact than the MBSs on the SINR coverage probability.In addition,the decrease in MBSs density will reduce the average bandwidth allocated to the user equipment(UE),thus reducing the rate coverage probability.展开更多
Introduction: Rheumatoid arthritis (RA) is a chronic, erosive and deforming inflammatory rheumatic disease. In the era of biotherapies and the arrival of biosimilars in sub-Saharan Africa, the objective of this study ...Introduction: Rheumatoid arthritis (RA) is a chronic, erosive and deforming inflammatory rheumatic disease. In the era of biotherapies and the arrival of biosimilars in sub-Saharan Africa, the objective of this study was to describe plasma IL-6 variations in RA patients at Cité Verte District Hospital (Cameroon). Material and Methods: Descriptive and analytical cross-sectional study from December 1, 2021 to May 31, 2022. We included patients over 18 years old suffering from RA (ACR/EULAR 2010). Patients with an infection were not included. The data collected were age, sex, smoking status, family history, disease duration, disease activity by DAS28, CRP, rheumatoid factor, and plasma level of IL-6. Bone erosion was sought on radiography and ultrasound. Result: We included 31 patients, 25 of whom were women (80.6%). The mean age was 47.27 ± 17.97 years. Disease activity was predominantly moderate (32.3%) and severe (32.3%). Mean IL-6 level was 15.29 ± 2.36 pg/ml (extremes: 11.26 pg/ml and 20.15 pg/ml). IL-6 levels were higher in patients with a history of smoking. Similarly, IL-6 levels were higher in patients with mildly active RA in remission than in moderately and severely active RA. Mean IL-6 levels were significantly higher in patients with erosive RA (16.3 pg/ml VS 14.6 pg/ml). Conclusion: IL-6 levels were significantly elevated in men, weaned smokers and patients with bone erosions.展开更多
Along with the popularity of environmental protection concepts, the environmental treatment of water pollution attracts widespread attention, among which, the research on Bi-based semiconductor photocatalytic degradat...Along with the popularity of environmental protection concepts, the environmental treatment of water pollution attracts widespread attention, among which, the research on Bi-based semiconductor photocatalytic degradation technology has made great progress. However, the development of such bismuth-based composites still remains a challenging task due to difficult recovery and low catalytic efficiency. Herein, a novel CC/BiPO4</sub>/Bi2</sub>WO6</sub> composite was successfully synthesized through two-step hydrothermal method using activated flexible carbon cloth as a substrate. The results of the photocatalytic degradation experiments showed that the obtained CC/BiPO<sub>4</sub>/Bi<sub>2</sub>WO<sub>6</sub> composites can degrade 92.1% RhB in 60 min under UV-visible light irradiation, which was much higher than that of unloaded BiPO4</sub> (24.4%) and BiPO4</sub>/Bi2</sub>WO6</sub> (52.9%), exhibiting a better adsorption-photocatalytic degradation performance than BiPO4</sub> and BiPO4</sub>/Bi2</sub>WO6</sub>. Photoluminescence spectra indicated that the improved photocatalytic activity was due to the more effective inhibition of photogenerated carrier complexation. Furthermore, the radical capture experiments confirmed that h<sup>+</sup>, ·OH and O<sub>2</sub>-</sup> were the main active substances in the photocatalytic degradation process of RhB by the CC/BiPO4</sub>/Bi2</sub>WO6</sub> composites. More importantly, the prepared CC/BiPO4</sub>/Bi2</sub>WO6</sub> composite had a simple separation process and good recycling stability, and its photocatalytic degradation efficiency can still reach 53.3% after six cycles of RhB degradation. .展开更多
针对奇台110 m口径全可动射电望远镜(QiTai radio Telescope,QTT)天线副面调整机构的技术指标,文中提出了一种基于6-UPS并联机器人的副面调整机构。分别利用多刚体动力学分析和控制仿真软件对副面调整机构进行了虚拟样机建模和动力学仿...针对奇台110 m口径全可动射电望远镜(QiTai radio Telescope,QTT)天线副面调整机构的技术指标,文中提出了一种基于6-UPS并联机器人的副面调整机构。分别利用多刚体动力学分析和控制仿真软件对副面调整机构进行了虚拟样机建模和动力学仿真,得出副面调整机构运动关节在天线指天和仰平两种工况下从零位运动至指定位姿所需要的最大驱动力。进一步建立了大射电望远镜副面调整机构的有限元模型,对其零位时的结构进行了模态分析,得到了前6阶固有频率,为工程设计提供了理论参考。展开更多
Objectivs Enzyme/prodrug gene therapy provides a potential strategy for the treatment of glioma.Because of the limitations of using viral vectors for clinical application, we investigated the feasibility of cationicam...Objectivs Enzyme/prodrug gene therapy provides a potential strategy for the treatment of glioma.Because of the limitations of using viral vectors for clinical application, we investigated the feasibility of cationicamphiphile-mediated enzyme/prodrug gene transfer into C6 glioma cells. Methods Rat C6 glioma cells weretransfected with pUT599plasmid encoding the herpes simplex virus thymidine kinase (HSV-tk) gene via DOTAPand tested for chemosensitivity of prodrug ganciclovir (GCV). To demonstrate in vitro bystander effect, HSV-tkpositive cells were co-cultured with HSV-tk negative cells at varying proportions. Results DOTAP mediatedHSV-tk gene transfer into C6 cells showed 30%-40% of transfection efficiency. HSV-tk infected C6 glioma cellswere rendered sensitive to concentrations of GCV that were 3-4 logs lower than uninfected cells, with an IC05 of0.087μmol/L. In terms of the bystander effect, the viability of co-cultured cells decreased with increasingpopulations of HSV-tk positive cells after GCV treatment. Conclusion C6 cells were successfully transfected withthe HSV-tk gene via cationic amphiphile and displayed a strong bystander effect after GCV treatment. Cationicamphiphile - mediated HSV- tk/GCV chemosensitivity System may have promise as an intratumoral treatment forglioma.展开更多
基金supported by National Natural Science Foundation of China(62071215,62271243,91963128)National Key Research and Development Program of China(2017YFA0700201)the Joint Fund of Ministry of Education for Equipment Pre-research(8091B032112),Priority Academic Program Development of Jiangsu Higher Education Institutions,Fundamental Research Funds for the Central Universities and Jiangsu Provincial Key Laboratory of Advanced Manipulating Technique of Electromagnetic Wave.
文摘Reconfigurable intelligent surface(RIS)is emerged as a promising technique to solve the challenges faced by future wireless communication networks.Although the most commonly used electrically-controlled RISs can achieve millisecond-scale speed of dynamic switch,they have a large number of microwave circuit elements(such as PIN diodes or varactors)which will bring non-negligible insertion loss,and the complicity of the bias network to electrically addressing each element will increase with the expansion of the RIS aperture.Aiming at further reducing the fabrication cost and power consumption,herein an electromechanical RIS used for sub-6G wireless communication is proposed.The electromechanical RIS is designed with a passive metasurface and step-motor driver modules,providing simultaneous high-efficiency reflection(over 80%)and continuous reflection phase coverage of 360.Through electromechanical control,the RIS system can realize different reflective wavefront shaping,and has been employed in the indoor sub-6G wireless environment demonstrating a maximum signal improvement of 8.3 dB.The proposed electromechanical RIS is particularly useful for wireless signal enhancement in static blind area,and has the obvious advantage of not requiring continuous power supply after the RIS being regulated.Therefore,it greatly reduces the overall cost and power consumption which may have potentials in indoor application scenarios for improving wireless communication performance.
基金supported in part by the National Key R&D Program of China(2018YFE0100500)by the National Natural Science Foundation of China(61871387,61861041,and 62171354)by the Natural Science Basic Research Program of Shaanxi(2019JM-019).
文摘The joint adoption of sub-6GHz and millimeter wave(mmWave)technology can prevent the blind spots of coverage,enabling comprehensive coverage while realizing high-speed communication rate.According to the sensitivity of mmWave,base stations should be more densely deployed,which is not well described by existing Poisson hole process(PHP)and the Poisson point process(PPP)models.This paper establishes a sub-6GHz and mmWave hybrid heterogeneous cellular network based on the modified Poisson hole process(MPHP).In our proposed model,the sub-6GHz base stations follow the PPP,and the mmWave base stations(MBSs)follow MPHP distribution.The expressions of the coverage probability are derived by using the interference calculation method of integrating the nearest sector exclusion area.Our theoretical analysis has been verified through simulation results,suggesting that the increase in the cell radius decreases the coverage probability of signal-to-interference-plus-noise ratio(SINR),whereas the increase in the sector parameter has the opposite effect.The variation of sub-6GHz base stations(SBSs)density imposes more significant impact than the MBSs on the SINR coverage probability.In addition,the decrease in MBSs density will reduce the average bandwidth allocated to the user equipment(UE),thus reducing the rate coverage probability.
文摘Introduction: Rheumatoid arthritis (RA) is a chronic, erosive and deforming inflammatory rheumatic disease. In the era of biotherapies and the arrival of biosimilars in sub-Saharan Africa, the objective of this study was to describe plasma IL-6 variations in RA patients at Cité Verte District Hospital (Cameroon). Material and Methods: Descriptive and analytical cross-sectional study from December 1, 2021 to May 31, 2022. We included patients over 18 years old suffering from RA (ACR/EULAR 2010). Patients with an infection were not included. The data collected were age, sex, smoking status, family history, disease duration, disease activity by DAS28, CRP, rheumatoid factor, and plasma level of IL-6. Bone erosion was sought on radiography and ultrasound. Result: We included 31 patients, 25 of whom were women (80.6%). The mean age was 47.27 ± 17.97 years. Disease activity was predominantly moderate (32.3%) and severe (32.3%). Mean IL-6 level was 15.29 ± 2.36 pg/ml (extremes: 11.26 pg/ml and 20.15 pg/ml). IL-6 levels were higher in patients with a history of smoking. Similarly, IL-6 levels were higher in patients with mildly active RA in remission than in moderately and severely active RA. Mean IL-6 levels were significantly higher in patients with erosive RA (16.3 pg/ml VS 14.6 pg/ml). Conclusion: IL-6 levels were significantly elevated in men, weaned smokers and patients with bone erosions.
文摘Along with the popularity of environmental protection concepts, the environmental treatment of water pollution attracts widespread attention, among which, the research on Bi-based semiconductor photocatalytic degradation technology has made great progress. However, the development of such bismuth-based composites still remains a challenging task due to difficult recovery and low catalytic efficiency. Herein, a novel CC/BiPO4</sub>/Bi2</sub>WO6</sub> composite was successfully synthesized through two-step hydrothermal method using activated flexible carbon cloth as a substrate. The results of the photocatalytic degradation experiments showed that the obtained CC/BiPO<sub>4</sub>/Bi<sub>2</sub>WO<sub>6</sub> composites can degrade 92.1% RhB in 60 min under UV-visible light irradiation, which was much higher than that of unloaded BiPO4</sub> (24.4%) and BiPO4</sub>/Bi2</sub>WO6</sub> (52.9%), exhibiting a better adsorption-photocatalytic degradation performance than BiPO4</sub> and BiPO4</sub>/Bi2</sub>WO6</sub>. Photoluminescence spectra indicated that the improved photocatalytic activity was due to the more effective inhibition of photogenerated carrier complexation. Furthermore, the radical capture experiments confirmed that h<sup>+</sup>, ·OH and O<sub>2</sub>-</sup> were the main active substances in the photocatalytic degradation process of RhB by the CC/BiPO4</sub>/Bi2</sub>WO6</sub> composites. More importantly, the prepared CC/BiPO4</sub>/Bi2</sub>WO6</sub> composite had a simple separation process and good recycling stability, and its photocatalytic degradation efficiency can still reach 53.3% after six cycles of RhB degradation. .
文摘针对奇台110 m口径全可动射电望远镜(QiTai radio Telescope,QTT)天线副面调整机构的技术指标,文中提出了一种基于6-UPS并联机器人的副面调整机构。分别利用多刚体动力学分析和控制仿真软件对副面调整机构进行了虚拟样机建模和动力学仿真,得出副面调整机构运动关节在天线指天和仰平两种工况下从零位运动至指定位姿所需要的最大驱动力。进一步建立了大射电望远镜副面调整机构的有限元模型,对其零位时的结构进行了模态分析,得到了前6阶固有频率,为工程设计提供了理论参考。
文摘Objectivs Enzyme/prodrug gene therapy provides a potential strategy for the treatment of glioma.Because of the limitations of using viral vectors for clinical application, we investigated the feasibility of cationicamphiphile-mediated enzyme/prodrug gene transfer into C6 glioma cells. Methods Rat C6 glioma cells weretransfected with pUT599plasmid encoding the herpes simplex virus thymidine kinase (HSV-tk) gene via DOTAPand tested for chemosensitivity of prodrug ganciclovir (GCV). To demonstrate in vitro bystander effect, HSV-tkpositive cells were co-cultured with HSV-tk negative cells at varying proportions. Results DOTAP mediatedHSV-tk gene transfer into C6 cells showed 30%-40% of transfection efficiency. HSV-tk infected C6 glioma cellswere rendered sensitive to concentrations of GCV that were 3-4 logs lower than uninfected cells, with an IC05 of0.087μmol/L. In terms of the bystander effect, the viability of co-cultured cells decreased with increasingpopulations of HSV-tk positive cells after GCV treatment. Conclusion C6 cells were successfully transfected withthe HSV-tk gene via cationic amphiphile and displayed a strong bystander effect after GCV treatment. Cationicamphiphile - mediated HSV- tk/GCV chemosensitivity System may have promise as an intratumoral treatment forglioma.
