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891.
892.
可调谐二极管激光吸收光谱法测量气体温度 总被引:3,自引:1,他引:2
研究了一种新型的非接触式测温技术——可调谐二极管激光吸收光谱(TDLAS)测温技术。介绍了温度测量及调制吸收光谱技术原理,分析了调制幅度对气体温度测量的影响。优选了氧气吸收谱线对13163.78 cm-1和13164.18 cm-1,在搭建的高温实验系统上,实现了气体温度和浓度的同时测量。通过分析实测波形获得了谱线13164.18 cm-1在823~1323 K温度范围内的碰撞展宽系数和温度指数。实验结果表明,在823~1323 K温度范围内,系统温度测量的线性误差为0.65%,最大波动为±15 K。 相似文献
893.
Cancer is one of the most difficult diseases in human society. Therefore, it is urgent for us to understand its pathogenesis and improve the cure rate. Exosomes are nanoscale membrane vesicles formed by a variety of cells through endocytosis. As a new means of intercellular information exchange, exosomes have attracted much attention. Noncoding RNAs exist in various cell compartments and participate in a variety of cellular reactions; in particular, they can be detected in exosomes bound to lipoproteins and free circulating molecules. Increasing evidence has suggested the potential roles of exosomal noncoding RNAs in the progression of tumors. Herein, we present a comprehensive update on the biological functions of exosomal noncoding RNAs in the development of cancer. Specifically, we mainly focus on the effects of exosomal noncoding RNAs, including microRNAs, circular RNAs, long noncoding RNAs, small nuclear RNAs, and small nucleolar RNAs, on tumor growth, metastasis, angiogenesis, and chemoresistance. Moreover, we outline the current clinical implications concerning exosomal noncoding RNAs in cancer treatment.Subject terms: Cancer, Non-coding RNAs 相似文献
894.
Xinhua Li Dongpeng Ma Zhaoming Lu Yiping Liu Zhenyu Jiang Liqun Tang Zejia Liu Licheng Zhou 《Acta Mechanica Solida Sinica》2021,34(4):539-549
This paper studies the effects of hygrothermal environment at different tempera-tures and ultraviolet(UV)radiation on the bending properties of epoxy polymer mo... 相似文献
895.
On a lattice with 2+1-flavor dynamical domain-wall fermions at the physical pion mass,we calculate the decay constants of D_s* , D* ,and φ .The lattice size is 48^3×96 ,which corresponds to a spatial extension of -5.5 fm,with a lattice spacing of a\approx a≈0.114 fm.For the valence light,strange,and charm quarks,we use overlap fermions at several mass points close to their physical values.Our results at the physical point are fD=213(5) MeV, fDs=249(7) MeV, fD*=234(6) MeV, fDs*=274(7) MeV,and fDs=241(9) MeV.The couplings of D* and D_s* to the tensor current( fVT )can be derived from ratios fD*^T/fD*=0.91(4) and fDs*^T/fDs*=0.92(4) ,respectively,which are the first lattice quantum chromodynamics(QCD)results.We also obtain ratios fD*/fD=1.10(3) and fDs*/fDs=1.10(4) ,which reflect the size of heavy quark symmetry breaking in charmed mesons.Ratios fDs/fD=1.16(3) and fDs*/fD*=1.17(3) can be taken as a measure of SU(3)flavor symmetry breaking. 相似文献
896.
897.
Han Luo Wei Qin Hong Zhang Fu-Cai Ren Wen-Tao Fang Qing-Hua Kong Liu Yang Jian-Mei Zhang Cheng-Wu Fang Jiang-Miao Hu Shou-Jin Liu 《Molecules (Basel, Switzerland)》2022,27(5)
The present study aimed to identify the composition of the aerial parts of Rubia cordifolia L. A chemical investigation on the EtOAc extracts from the aerial parts of Rubia cordifolia resulted in the isolation of four new anthraquinones, namely Cordifoquinone A–D (1–4), along with 16 known anthraquinones. Their structures were elucidated on the basis of NMR and HR-ESIMS data. All isolates were assessed for their inhibitory effects on NO production in LPS-stimulated RAW 264.7 macrophage cells. Compounds 1, 3 and 10 exhibited significant inhibitory activities with IC50 values of 14.05, 23.48 and 29.23 μmol·L−1, respectively. Their antibacterial activities of four bacteria, Escherichia coli (ATCC 25922), Staphylococcus aureus subsp. aureus (ATCC 29213), Salmonella enterica subsp. enterica (ATCC 14028) and Pseudomonas aeruginosa (ATCC 27853), were also evaluated. Our results indicated that the antibacterial activity of these compounds is inactive. 相似文献
898.
Energetic molecular crystals are widely applied for military and civilian purposes, and molecular forcefields (FF) are indispensable for treating the microscopic issues therein. This article reviews the three types of molecular FFs that are applied widely for describing energetic crystals—classic FFs, consistent FFs, and reactive FFs (ReaxFF). The basic principle of each type of FF is briefed and compared, with the application introduced, predicting polymorph, morphology, thermodynamics, vibration spectra, thermal property, mechanics, and reactivity. Finally, the advantages and disadvantages of these FFs are summarized, and some directions of future development are suggested. 相似文献
899.
基于Hill动力学与Michaelis-Menten方程,建立理论模型研究发状分裂相关增强子1(hairy and enhancer of split 1,Hes1)调控蛋白激酶B (Protein Kinase B,AKT)-鼠双微体2 (Murine Double Minute2,MDM2)-抗癌基因p53(p53)-第10号染色体缺失的磷酸酶及张力蛋白同源的基因(Phosphatase and tensin homolog deleted on chromosome ten,PTEN)通路的一种物理机制.研究发现,Hes1通过与PTEN结合抑制PTEN表达,并调控AKT信号.表明了Hes1蛋白的合成,以及Hes1与PTEN相互作用调控AKTMDM2-p53-PTEN通路信号,将会有效地控制细胞结果 . Hes1作为AKT-MDM2-p53-PTEN信号通路中上游调节的重要因素,还可以在一定程度上通过影响p53蛋白功能,改变p53对肿瘤的抑制性.理论结果可用于预测Notch通路信号异常诱导的致癌性,并进一步揭示了Notch信号通路影响细胞AKT-MDM2-p53-PTEN通路的激活... 相似文献
900.
本文基于Flory-Huggins理论,建立理论模型研究水合作用与pH调控两性离子聚合物(ZP)刷的相变行为.理论模型考虑ZP的水合作用,以及ZP刷体系中的静电作用.研究发现,在不同pH条件下,ZP刷的体积分数随着水合作的减弱而的增加.随着pH的变化,ZP刷构象随着水合性转变行为明显改变,这是由于pH调控ZP链单体带有过多的净电荷(正电荷或负电荷),致使ZP链内出现静电排斥导致ZP刷溶胀.另外,当ZP链单体呈现过多的净电荷,会在很大程度上决定ZP刷体系静电势,影响ZP刷的相变行为.通过考察体系自由能,我们还发现,ZP刷体系自由能呈现了极大值,随着pH值的变化,自由能呈现的极大值随之改变,由此表明了体系的不稳定性,进而导致ZP刷体系发生相变. 相似文献