铁死亡的调控机制及其在蒽环类药物心脏毒性中的研究进展

铁死亡是由铁介导的脂质过氧化累积引起的一种新的细胞死亡模式,在心血管疾病中发挥重要作用。蒽环类药物是最常用的化疗药物之一,用于治疗多种癌症。虽然药物有效,但其益处有时会受到急性和/或迟发性心脏毒性副作用(尤其是心力衰竭)的影响。证据表明蒽环类药物心脏毒性与心肌细胞铁死亡密切相关,现就铁死亡在蒽环类药物心脏毒性发生过程中的机制及潜在的治疗靶点进行综述,以期为减弱蒽环类化疗药物所致心肌损伤提供新的治疗靶点与研究方向。

真武汤合血府逐瘀汤加减治疗慢性心力衰竭的Meta分析及试验序贯分析

目的 系统评价真武汤合血府逐瘀汤加减治疗慢性心力衰竭(CHF)的临床疗效。方法 计算机检索从建库至2022年3月1日万方数据库(Wanfang)、维普数据库(VIP)、中国知网(CNKI)、Cochrane Library、Web of Science、PubMed等数据库发表的所有关于真武汤合血府逐瘀汤加减治疗CHF的文献。纳入文献质量参照Cochrane评估标准评价,使用RevMan 5.4及TSA 0.9.5.10 Beta软件分别对数据进行Meta分析和试验序贯分析(TSA)。结果 纳入20项真武汤合血府逐瘀汤加减治疗CHF的随机对照研究,共计1 619例患者。与对照组比较,试验组(真武汤合血府逐瘀汤加减结合西医常规治疗)的临床疗效[RR=1.23,95%CI=(1.18,1.29),P<0.000 01]、左室射血分数[WMD=7.59,95%CI=(5.53,9.64),P<0.000 01]、心脏指数[WMD=0.32,95%CI=(0.25,0.39),P<0.000 01]显著提高,左室舒张末期内径缩小[WMD=-2.30,95%CI=(-2.41,-2.18),P<0.000 01],B型利钠肽[WMD=-25.47,95%CI=(-26.93,-24.02),P<0.000 01]及氨基末端脑钠肽前体[WMD=-281.44,95%CI=(-406.06,-156.83),P<0.000 01]降低,6 min步行距离明显增加[WMD=69.40,95%CI=(59.93,78.86),P<0.000 01],药物不良反应明显减少[RR=0.29,95%CI=(0.15,0.56),P=0.000 2]。试验序贯分析进一步证实了其临床疗效,排除了假阳性。结论 真武汤合血府逐瘀汤结合西医常规治疗CHF的临床疗效优于单纯西医常规治疗,且临床不良反应少。鉴于纳入文献的质量一般,上述结果尚需更多高质量、大样本的临床随机对照试予以证实。

面向业务优先级的宽带卫星ATDM前向链路资源调度算法

研究了宽带卫星通信系统中异步时分复用(ATDM)前向链路资源受限条件下的资源调度问题。以优先传输实时业务、兼顾用户优先级以及系统吞吐量为优化目标,以调制编码模式、复帧数量和优先级等为约束,建立了资源调度目标函数。提出了以初始解集构造、增强全局搜索为核心的改进蚁群优化算法(ACO),求解该资源调度问题,避免了传统的蚁群优化算法存在初始阶段信息素匮乏导致的搜索速度过慢、局部搜索能力较弱以及易陷入局部最优等缺点,提高了算法在实时性、高效性需求较强的卫星调度过程中的应用。仿真实验表明,所提算法可以准确求得最优解,准确率高达99.8%,其收敛速度较传统算法提高了55.6%,与传统算法相比,所提算法已调度业务的目标函数f、综合权重y、系统吞吐量分别提高了8.4%、6.6%、12.1%,在资源调度方面具有良好的准确性、敛散性和优化性能,且与同类型优化算法相比具有更高的调度效率,适用于ATDM卫星通信系统资源调度。

农村电子商务发展优化路径探究

近年来随着互联网的迅速发展,农村电子商务得到了迅速发展。文章分析了农村电子商务发展对中国经济的影响,展示了我国农村电子商务发展的特点,指出了当下农村电子商务发展出现的问题,提出了农村电子商务未来高质量发展路径建议。

Signal structure of the Chinese Area Positioning System

Proper signal structure is very important in the navigation, positioning, and time services of a satellite navigation system. In this paper, the carrier wave characteristics, ranging code functions, BOC modulation, navigation data rate, the error-correcting methods, and signal channel resource allocation are discussed in terms of the technical characteristics of the transforming satellite navigation system and the resources of communication satellites. The results show that dual-frequency of C band in the Chinese Area Positioning System (CAPS), compound ranging code, a combination of the coarse code and precise code, BOC modulation, separate-channel transmission of different users are compatible with the satellite navigation system at present. The experiments show that the current signal structure can meet the demand of CAPS.

Time synchronization and carrier frequency control of CAPS navigation signals generated on the ground

The Chinese Area Positioning System (CAPS) works without atomic clocks on the satellite, and the CAPS navigation signals transmitted on the ground may achieve the same effect as that with high-performance atomic clocks on the satellite. The primary means of achieving that effect is through the time synchronization and carrier frequency control of the CAPS navigation signals generated on the ground. In this paper the synchronization requirements of different time signals are analyzed by the formation of navigation signals, and the theories and methods of the time synchronization of the CAPS navigation signals generated on the ground are also introduced. According to the conditions of the high-precision satellite velocitymeasurement signal source, the carrier frequency and its chains of the navigation signals are constructed. CAPS velocity measurement is realized by the expected deviation of real time control to the carrier frequency, and the precision degree of this method is also analyzed. The experimental results show that the time synchronization precision of CAPS generating signals is about 0.3 ns and the precision of the velocity measurement signal source is about 4 cm/s. This proves that the theories and methods of the generating time synchronization and carrier frequency control are workable.

Satellite virtual atomic clock with pseudorange difference function

Satellite atomic clocks are the basis of GPS for the control of time and frequency of navigation signals. In the Chinese Area Positioning System (CAPS), a satellite navigation system without the satellite atomic clocks onboard is successfully developed. Thus, the method of time synchronization based on satellite atomic clocks in GPS is not suitable. Satellite virtual atomic clocks are used to implement satellite navigation. With the satellite virtual atomic clocks, the time at which the signals are transmitted from the ground can be delayed into the time that the signals are transmitted from the satellites and the pseudorange measuring can be fulfilled as in GPS. Satellite virtual atomic clocks can implement the navigation, make a pseudorange difference, remove the ephemeris error, and improve the accuracy of navigation positioning. They not only provide a navigation system without satellite clocks, but also a navigation system with pseudorange difference.

四氢姜黄素抗焦虑及抗抑郁作用的机制研究

目的研究四氢姜黄素(THC)抗焦虑及抗抑郁的作用机制。方法将小鼠随机分为正常组、模型组及THC低、中、高剂量组(5、10、20 mg·kg^(-1)),每日将小鼠置离心管中4 h,建立慢性束缚应激抑郁模型;灌胃给予THC,正常组和模型组给予等体积的橄榄油;造模21 d后,进行行为学检测;检测后,处死小鼠,取海马体,用于生化和病理检测。结果THC可明显改善小鼠的多项行为学指标;改善抑郁小鼠海马体内脑源性神经营养因子、Toll样受体-4、白细胞介素-1β、肿瘤坏死因子α、一氧化氮合成酶、离子钙结合衔接分子1蛋白的表达。结论THC可缓解小鼠焦虑及抑郁行为,其机制可能与对海马体的抗炎作用有关。