无人机三维路径规划是一个比较复杂的全局优化问题,其目标是在考虑威胁和约束的条件下,获得最优或接近最优的飞行路径。针对鲸鱼算法在进行无人机三维航迹规划时,存在容易陷入局部最优、收敛速度较慢、收敛精度不够高等问题,提出了一种...无人机三维路径规划是一个比较复杂的全局优化问题,其目标是在考虑威胁和约束的条件下,获得最优或接近最优的飞行路径。针对鲸鱼算法在进行无人机三维航迹规划时,存在容易陷入局部最优、收敛速度较慢、收敛精度不够高等问题,提出了一种基于莱维飞行(Lévy flight)的鲸鱼优化算法(Levy Flight Based on Whale Optimization Algorithm, LWOA),用于解决无人机三维路径规划问题。该算法在迭代过程中加入了Levy飞行对最优解进行随机扰动;引入了信息交流机制,通过当前全局最优解和个体记忆最优解以及邻域最优解来更新个体的位置,能够更好地权衡局部收敛和全局开发。仿真结果表明,所提路径规划算法可以有效避开威胁区,收敛速度更快,收敛精度更高,且更不易陷入局部最优解。当迭代次数为300次、种群个数为50时,LWOA算法求得的成本函数值是PSO算法的91.1%,是GWO算法的92.1%,是WOA算法的95.9%,航迹代价更小。展开更多
Permafrost,being an important component of the cryosphere,is sensitive to climate change.Therefore,it is necessary to investigate the change of temperature within permafrost.In this study,we proposed a Fourier series ...Permafrost,being an important component of the cryosphere,is sensitive to climate change.Therefore,it is necessary to investigate the change of temperature within permafrost.In this study,we proposed a Fourier series model derived from the conduction equation to simulate permafrost thermal behavior over a year.The boundary condition was represented by the Fourier series and the geothermal gradient.The initial condition was represented as a linear function relative to the geothermal gradient.A comparative study of the different models(sinusoidal model,Fourier series model,and the proposed model)was conducted.Data collected from the northern Da Xing’anling Mountains,Northeast China,were applied for parameterization and validation for these models.These models were compared with daily mean ground temperature from the shallow permafrost layer and annual mean ground temperature from the bottom permafrost layer,respectively.Model performance was assessed using three coefficients of accuracy,i.e.,the mean bias error,the root mean square error,and the coefficient of determination.The comparison results showed that the proposed model was accurate enough to simulate temperature variation in both the shallow and bottom permafrost layer as compared with the other two Fourier series models(sinusoidal model and Fourier model).The proposed model expanded on a previous Fourier series model for which the initial and bottom boundary conditions were restricted to being constant.展开更多
Objective: To observe the effects of Guizhi Fuling Capsule(GZFLC) on myeloma cells and explore the mechanisms. Methods: MM1S and RPMI 8226 cells were co-cultured with different concentrations of serum and the cell exp...Objective: To observe the effects of Guizhi Fuling Capsule(GZFLC) on myeloma cells and explore the mechanisms. Methods: MM1S and RPMI 8226 cells were co-cultured with different concentrations of serum and the cell experiments were divided into negative(10%, 20% and 40%) groups, GZFLC(10%, 20%, and 40%)groups and a control group. Cell counting kit-8(CCK-8) assays and flow cytometry were used to detect the viability and apoptosis levels of myeloma cells. The effects on mitochondria were examined by reactive oxygen specie(ROS) and tetrechloro-tetraethylbenzimidazol carbocyanine iodide(JC-1) assays. Western blot was used to detect the expression of B cell lymphoma-2(Bcl-2), Bcl-2-associated X(Bax), cleaved caspase-3,-9, cytochrome C(Cytc)and apoptotic protease-activating factor 1(Apaf-1). RPMI 8226 cells(2×107) were subcutaneously inoculated into 48 nude mice to study the in vivo antitumor effects of GZFLC. The mice were randomly divided into four groups using a completely randomized design, the high-, medium-, or low-dose GZFLC(840, 420, or 210 mg/kg per day,respectively) or an equal volume of distilled water, administered daily for 15 days. The tumor volume changes in and survival times of the mice in the GZFLC-administered groups and a control group were observed. Cytc and Apaf-1 expression levels were detected by immunohistochemistry. Results: GZFLC drug serum decreased the viability and increased the apoptosis of myeloam cells(P<0.05). In addition, this drug increased the ROS levels and decreased the mitochondrial membrane potential(P<0.01). Western blot showed that the Bcl-2/Bax ratios were decreased in the GZFLC drug serum-treated groups, whereas the expression levels of cleaved caspase-3,-9,Cytc and Apaf-1 were increased(all P<0.01). Over time, the myeloma tumor volumes of the mice in the GZFLCadministered groups decreased, and survival time of the mice in the GZFLC-administered groups were longer than that of the mice in the control group. Immunohistochemical analysis of tumor tissues from the mice in the GZFLCadministered groups revealed that the Cytc and Apaf-1 expression levels were increased(P<0.05). Conclusion:GZFLC promoted apoptosis of myeloma cells through the mitochondrial apoptosis pathway and significantly reduced the tumor volumes in mice with myeloma, which prolonged the survival times of the mice.展开更多
文摘双硫仑作为一种治疗慢性酒精中毒的药物在临床中广泛使用。近年来,研究者提出了双硫仑治疗癌症的具体机制,如抑制乙醛脱氢酶(acetaldehyde dehydrogenase,ALDH)的活性、提高细胞内活性氧(reactive oxygen species,ROS)的浓度、抑制核因子kappa-B(nuclear factor kappa-B,NF-κB)的活性,促进与核蛋白定位蛋白4(nuclear protein localization protein 4,NPL4)的结合、抑制FROUNT蛋白等,并在多种癌症模型中证明了双硫仑的抗癌活性。抗肾小球基底膜型肾小球肾炎是急进性肾小球肾炎中的一种类型,该病一旦被确诊,就需要第一时间给予治疗,尽量帮助患者缓解症状、改善预后。研究表明,双硫仑可通过抑制C-C趋化因子受体2型/C-C趋化因子受体5型(C-C chemokine receptor type 2/C-C chemokine receptor type 5,CCR-2/CCR-5)和FROUNT蛋白之间的相互作用来抑制巨噬细胞的迁移、聚集、活化来缓解抗肾小球基底膜型肾小球肾炎,这表明双硫仑对该类患者具有潜在的治疗价值。本文简要回顾了双硫仑最新研究中阐明的相关作用分子机制,展望了未来双硫仑作为新的药物治疗抗肾小球基底膜型肾小球肾炎的前景。
文摘无人机三维路径规划是一个比较复杂的全局优化问题,其目标是在考虑威胁和约束的条件下,获得最优或接近最优的飞行路径。针对鲸鱼算法在进行无人机三维航迹规划时,存在容易陷入局部最优、收敛速度较慢、收敛精度不够高等问题,提出了一种基于莱维飞行(Lévy flight)的鲸鱼优化算法(Levy Flight Based on Whale Optimization Algorithm, LWOA),用于解决无人机三维路径规划问题。该算法在迭代过程中加入了Levy飞行对最优解进行随机扰动;引入了信息交流机制,通过当前全局最优解和个体记忆最优解以及邻域最优解来更新个体的位置,能够更好地权衡局部收敛和全局开发。仿真结果表明,所提路径规划算法可以有效避开威胁区,收敛速度更快,收敛精度更高,且更不易陷入局部最优解。当迭代次数为300次、种群个数为50时,LWOA算法求得的成本函数值是PSO算法的91.1%,是GWO算法的92.1%,是WOA算法的95.9%,航迹代价更小。
基金founded by the Key Joint Program of National Natural Science Foundation of China(NSFC)and Heilongjiang Province for Regional Development(No.U20A2082)National Natural Science Foundation of China(No.41971151)Natural Science Foundation of Heilongjiang Province(No.TD2019D002)。
文摘Permafrost,being an important component of the cryosphere,is sensitive to climate change.Therefore,it is necessary to investigate the change of temperature within permafrost.In this study,we proposed a Fourier series model derived from the conduction equation to simulate permafrost thermal behavior over a year.The boundary condition was represented by the Fourier series and the geothermal gradient.The initial condition was represented as a linear function relative to the geothermal gradient.A comparative study of the different models(sinusoidal model,Fourier series model,and the proposed model)was conducted.Data collected from the northern Da Xing’anling Mountains,Northeast China,were applied for parameterization and validation for these models.These models were compared with daily mean ground temperature from the shallow permafrost layer and annual mean ground temperature from the bottom permafrost layer,respectively.Model performance was assessed using three coefficients of accuracy,i.e.,the mean bias error,the root mean square error,and the coefficient of determination.The comparison results showed that the proposed model was accurate enough to simulate temperature variation in both the shallow and bottom permafrost layer as compared with the other two Fourier series models(sinusoidal model and Fourier model).The proposed model expanded on a previous Fourier series model for which the initial and bottom boundary conditions were restricted to being constant.
基金Supported by the National Natural Science Foundation of China(No.82074348)the Taishan Scholar Project(No.tsqn201812145)+1 种基金the Key Technology Research and Development Program of Shandong(No.2019GSF108162)the Natural Science Foundation of Shandong Province(No.ZR2020MH388)。
文摘Objective: To observe the effects of Guizhi Fuling Capsule(GZFLC) on myeloma cells and explore the mechanisms. Methods: MM1S and RPMI 8226 cells were co-cultured with different concentrations of serum and the cell experiments were divided into negative(10%, 20% and 40%) groups, GZFLC(10%, 20%, and 40%)groups and a control group. Cell counting kit-8(CCK-8) assays and flow cytometry were used to detect the viability and apoptosis levels of myeloma cells. The effects on mitochondria were examined by reactive oxygen specie(ROS) and tetrechloro-tetraethylbenzimidazol carbocyanine iodide(JC-1) assays. Western blot was used to detect the expression of B cell lymphoma-2(Bcl-2), Bcl-2-associated X(Bax), cleaved caspase-3,-9, cytochrome C(Cytc)and apoptotic protease-activating factor 1(Apaf-1). RPMI 8226 cells(2×107) were subcutaneously inoculated into 48 nude mice to study the in vivo antitumor effects of GZFLC. The mice were randomly divided into four groups using a completely randomized design, the high-, medium-, or low-dose GZFLC(840, 420, or 210 mg/kg per day,respectively) or an equal volume of distilled water, administered daily for 15 days. The tumor volume changes in and survival times of the mice in the GZFLC-administered groups and a control group were observed. Cytc and Apaf-1 expression levels were detected by immunohistochemistry. Results: GZFLC drug serum decreased the viability and increased the apoptosis of myeloam cells(P<0.05). In addition, this drug increased the ROS levels and decreased the mitochondrial membrane potential(P<0.01). Western blot showed that the Bcl-2/Bax ratios were decreased in the GZFLC drug serum-treated groups, whereas the expression levels of cleaved caspase-3,-9,Cytc and Apaf-1 were increased(all P<0.01). Over time, the myeloma tumor volumes of the mice in the GZFLCadministered groups decreased, and survival time of the mice in the GZFLC-administered groups were longer than that of the mice in the control group. Immunohistochemical analysis of tumor tissues from the mice in the GZFLCadministered groups revealed that the Cytc and Apaf-1 expression levels were increased(P<0.05). Conclusion:GZFLC promoted apoptosis of myeloma cells through the mitochondrial apoptosis pathway and significantly reduced the tumor volumes in mice with myeloma, which prolonged the survival times of the mice.
