多用户正交多级差分混沌键控通信系统

针对传统差分混沌键控(differential chaos shift keying, DCSK)采用多电平方式传输多进制信息导致误比特率(bit error rate, BER)高的缺点,提出一种多用户正交多级DCSK(multi-user orthogonal multi-level DCSK, MOM-DCSK)通信系统。该系统将传输的多进制信息映射为不同的传输系数,多个传输系数分别乘以对应的Walsh码后调制在信息承载信号上,并且通过不同的延时传输多用户信息。在加性高斯白噪声(additive white Gaussian noise, AWGN)信道和多径Rayleigh衰落信道中推导了系统的理论BER公式并进行了仿真分析。结果显示，该系统在传输多进制信息时拥有较好的误码性能,并且在多用户传输领域中有较好的实际应用价值。     

飞秒光纤光源的波分解复用 复用实验

为研究飞秒光源作为链路初始光源的可行性，使用阵列波导光栅（AWG）对265 fs光纤光源进行波分解复用 复用实验。实验光源波长为1 52765～1 56505 nm，通道数为48，通道间隔为080 nm。研究发现:在分波实验中，飞秒光纤光源经过AWG后，扫描谱线3 dB带宽为064 nm ，相邻通道串扰为2726 dB，比连续光源增大502 dB；在合波实验中，观察到AWG多端口端对宽带光源的波长选择作用，验证了AWG的色散特性，发现多光束的输出谱线总体轮廓未出现太大变形；在波分解复用 复用实验中，谱线最大损耗为251 dB，输出谱线轮廓和初始光谱基本一致，信号在传输过程中未出现明显失真，证明飞秒光源作为链路初始光源的可行性。     

左Clifford双半环的性质与结构

定义了双半环的分配格和带双半环。利用这两个定义以及左Clifford半群的性质,给出了左双环和左Clifford双半环的定义,并得到了双半环是左双环的充分必要条件和双半环是左Clifford双半环的充分必要条件。     

PI-强LU富足半群

通过对C-L^U-富足半群的刻画,给出了PI-强L^U富足半群的结构定理。     

Blockage of the NLRP3 inflammasome by MCC950 improves anti-tumor immune responses in head and neck squamous cell carcinoma

The NLRP3 inflammasome is a critical innate immune pathway responsible for producing active interleukin (IL)-1β, which is associated with tumor development and immunity. However, the mechanisms regulating the inflammatory microenvironment, tumorigenesis and tumor immunity are unclear. Herein, we show that the NLRP3 inflammasome was over-expressed in human HNSCC tissues and that the IL-1β concentration was increased in the peripheral blood of HNSCC patients. Additionally, elevated NLRP3 inflammasome levels were detected in tumor tissues of Tgfbr1/Pten 2cKO HNSCC mice, and elevated IL-1β levels were detected in the peripheral blood serum, spleen, draining lymph nodes and tumor tissues. Blocking NLRP3 inflammasome activation using MCC950 remarkably reduced IL-1β production in an HNSCC mouse model and reduced the numbers of myeloid-derived suppressor cells (MDSCs), regulatory T cells (Tregs) and tumor-associated macrophages (TAMs). Moreover, inhibiting NLRP3 inflammasome activation increased the numbers of CD4⁺ and CD8⁺ T cells in HNSCC mice. Notably, the numbers of exhausted PD-1⁺ and Tim3⁺ T cells were significantly reduced. A human HNSCC tissue microarray showed that NLRP3 inflammasome expression was correlated with the expression of CD8 and CD4, the Treg marker Foxp3, the MDSC markers CD11b and CD33, and the TAM markers CD68 and CD163, PD-1 and Tim3. Overall, our results demonstrate that the NLRP3 inflammasome/IL-1β pathway promotes tumorigenesis in HNSCC and inactivation of this pathway delays tumor growth, accompanied by decreased immunosuppressive cell accumulation and an increased number of effector T cells. Thus, inhibition of the tumor microenvironment through the NLRP3 inflammasome/IL-1β pathway may provide a novel approach for HNSCC therapy.     

Microsatellite instability in gastric cancer: molecular bases,clinical perspectives,and new treatment approaches

Gastric cancer is one of the most aggressive malignancies, with limited treatment options in both locally advanced and metastatic setting, resulting in poor prognosis. Based on genomic characterization, stomach tumour has recently been described as a heterogeneous disease composed by different subtypes, each of them with peculiar molecular aspects and specific clinical behaviour. With an incidence of 22% among all western gastric tumour cases, stomach cancer with microsatellite instability was identified as one of these subgroups. Retrospective studies and limited prospective trials reported differences between gastric cancers with microsatellite stability and those with instability, mainly concerning clinical and pathological features, but also in regard to immunological microenvironment, correlation with prognostic value, and responses to treatment. In particular, gastric cancer with microsatellite instability constitutes a small but relevant subgroup associated with older age, female sex, distal stomach location, and lower number of lymph-node metastases. Emerging data attribute to microsatellite instability status a favourable prognostic meaning, whereas the poor outcomes reported after perioperative chemotherapy administration suggest a detrimental role of cytotoxic drugs in this gastric cancer subgroup. The strong immunogenicity and the widespread expression of immune-checkpoint ligands make microsatellite instability subtype more vulnerable to immunotherapeutic approach, e.g., with anti-PD-L1 and anti-CTLA4 antibodies. Since gastric cancer with microsatellite instability shows specific features and clinical behaviour not overlapping with microsatellite stable disease, microsatellite instability test might be suitable for inclusion in a diagnostic setting for all tumour stages to guarantee the most targeted and effective treatment to every patient.     

General mechanisms of drought response and their application in drought resistance improvement in plants

Plants often encounter unfavorable environmental conditions because of their sessile lifestyle. These adverse factors greatly affect the geographic distribution of plants, as well as their growth and productivity. Drought stress is one of the premier limitations to global agricultural production due to the complexity of the water-limiting environment and changing climate. Plants have evolved a series of mechanisms at the morphological, physiological, biochemical, cellular, and molecular levels to overcome water deficit or drought stress conditions. The drought resistance of plants can be divided into four basic types-drought avoidance, drought tolerance, drought escape, and drought recovery. Various drought-related traits, including root traits, leaf traits, osmotic adjustment capabilities, water potential, ABA content, and stability of the cell membrane, have been used as indicators to evaluate the drought resistance of plants. In the last decade, scientists have investigated the genetic and molecular mechanisms of drought resistance to enhance the drought resistance of various crops, and significant progress has been made with regard to drought avoidance and drought tolerance. With increasing knowledge to comprehensively decipher the complicated mechanisms of drought resistance in model plants, it still remains an enormous challenge to develop water-saving and drought-resistant crops to cope with the water shortage and increasing demand for food production in the future.     

基于盒维数的锚杆工作荷载无损检测研究

为研究锚杆工作荷载,应用了分形理论中的盒维数方法。根据一维杆波动理论,在锚杆外露端头安装一个自激式加速度传感器,利用锚杆无损检测加载试验台分级加载、检测标定测得锚杆-围岩相互作用体系在激发荷载作用下的速度响应,计算其加速度响应曲线的盒维数,拟合得出荷载-盒维数曲线,直观地判断锚杆工作荷载和锚固质量。