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991.
提出了一种改进的、可用于计算偏振相关拉曼增益的光纤拉曼放大器的非线性耦合波方程。建立了单模双折射光纤拉曼增益的数学模型,分析了线偏振抽运光以与光纤快轴成45°激励的单模双折射光纤拉曼放大器模型与实际具有随机双折射的光纤拉曼放大器的拉曼增益偏振相关特性的等价性。基于上述模型,提出了一个可定量表征单模光纤偏振模色散统计特性的拉曼增益偏振相关因子,用以替代常规的光纤拉曼放大器非线性耦合波方程中的偏振相关因子。计算结果与已报道文献的实验数据非常吻合。同时对抽运增益在同向和反向抽运方式下截然不同的增益偏振相关特性给出了合理的解释。 相似文献
992.
993.
研究了一种新型偶氮材料sy03在光控取向中的应用。将sy03加入聚酰亚胺SE-3310(Nissan)与N,N-二甲基甲酰胺(DMF)的混合溶液中作为90°扭曲向列相液晶显示(Twisted nematic liquid crystal display,TN-LCD)的光取向材料,测量由它作为取向膜的扭曲向列型盒的电光特性与仅用SE-3310取向的扭曲向列型盒电光特性比较,发现sy03偶氮的加入使得扭曲向列型盒的响应时间短到98 ms、阈值电压也降低到1.7 V左右。而且随曝光时间的增加,响应时间和衬比度都有所提高,电光响应曲线也更为陡峭。加热到150℃后,其电光特性并没有明显变化,证明了它良好的热稳定性。最后通过测量偏振紫外吸收光谱,分析得出液晶分子易取向方向与激发光源偏振方向垂直。 相似文献
994.
分别采用514 nm绿光、488 nm蓝光和390 nm紫外光作为敏化光,633 nm红光作为记录光,详细研究了敏化光波长对氧化(Fe,Ni):LiNbO3晶体全息记录性能的影响.结果表明:随着敏化光波长的逐渐减小,氧化(Fe,Ni):LiNbO3晶体的非挥发全息记录性能逐渐优化,390 nm紫外光是这三种敏化光中最优的敏化光.考虑敏化光的吸收,为了在双中心全息记录中获得最优的性能,应当选择合适波长的敏化光:一方面短波长敏化光能有效地敏化深中心;另一方面短波长敏化光的吸收太强(如对光折变效应无用的基质吸收),不能沿厚度方向有效地敏化晶体,所以实际上需折衷考虑,并从理论上给予了解释. 相似文献
995.
应用带完全匹配层边界条件的全矢量有限元方法,分析了高折射率椭圆芯布拉格光纤的偏振特性,详细讨论了光纤结构参量对模式双折射度以及群速度走离的影响,结果发现:高折射率椭圆芯布拉格光纤的模式双折射度可达10-2量级,比传统保偏光纤至少高出一个量级,并且表现出不同于传统保偏光纤的群速度走离特性;在保持较高双折射度的同时,通过合理的结构设计,可在一定的波长处灵活地获得较大的群速度走离或零走离特性,具有重要的潜在应用价值;最后,简要分析了低折射率区域的折射率变化对偏振特性的影响;研究结果有助于设计高性能的微结构保偏光纤。 相似文献
996.
997.
Kunqian Mu Kaiwen Jiang Yue Wang Zihan Zhao Song Cang Kaishun Bi Qing Li Ran Liu 《Molecules (Basel, Switzerland)》2022,27(3)
β-cyclodextrin has a unique annular hollow ultrastructure that allows encapsulation of various poorly water-soluble drugs in the resulting cavity, thereby increasing drug stability. As a bioactive molecule, the metabolism of β-cyclodextrin is mainly completed by the flora in the colon, which can interact with API. In this study, understanding the in vivo fate of β-cyclodextrin, a LC-MS/MS method was developed to facilitate simultaneous quantitative analysis of pharmaceutical excipient β-cyclodextrin and API dextromethorphan hydrobromide. The established method had been effectively used to study the pharmacokinetics, tissue distribution, excretion, and metabolism of β-cyclodextrin after oral administration in rats. Results showed that β-cyclodextrin was almost wholly removed from rat plasma within 36 h, and high concentrations of β-cyclodextrin distributed hastily to organs with increased blood flow velocities such as the spleen, liver, and kidney after administration. The excretion of intact β-cyclodextrin to urine and feces was lower than the administration dose. It can be speculated that β-cyclodextrin metabolized to maltodextrin, which was further metabolized, absorbed, and eventually discharged in the form of CO2 and H2O. Results proved that β-cyclodextrin, with relative low accumulation in the body, had good safety. The results will assist further study of the design and safety evaluation of adjuvant β-cyclodextrin and promote its clinical development. 相似文献
998.
Shujing Xu Dang Ding Xujie Zhang Lin Sun Dongwei Kang Boshi Huang Xinyong Liu Peng Zhan 《Molecules (Basel, Switzerland)》2022,27(3)
Viral infections pose a persistent threat to human health. The relentless epidemic of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has become a global health problem, with millions of infections and fatalities so far. Traditional approaches such as random screening and optimization of lead compounds by organic synthesis have become extremely resource- and time-consuming. Various modern innovative methods or integrated paradigms are now being applied to drug discovery for significant resistance in order to simplify the drug process. This review provides an overview of newly emerging antiviral strategies, including proteolysis targeting chimera (PROTAC), ribonuclease targeting chimera (RIBOTAC), targeted covalent inhibitors, topology-matching design and antiviral drug delivery system. This article is dedicated to Prof. Dr. Erik De Clercq, an internationally renowned expert in the antiviral drug research field, on the occasion of his 80th anniversary. 相似文献
999.
Birui Shi Yan Zhang Baolin Huang Huiping Lin Qiong Zhou Yujue Wang Zheng Cai Menghua Liu 《Molecules (Basel, Switzerland)》2022,27(3)
With the widespread clinical use of drug combinations, the incidence of drug–drug interactions (DDI) has significantly increased, accompanied by a variety of adverse reactions. Drug transporters play an important role in the development of DDI by affecting the elimination process of drugs in vivo, especially in the pathological state. Tubulointerstitial fibrosis (TIF) is an inevitable pathway in the progression of chronic kidney disease (CKD) to end-stage renal disease. Here, the dynamic expression changes of eleven drug transporters in TIF kidney have been systematically investigated. Among them, the mRNA expressions of Oat1, Oat2, Oct1, Oct2, Oatp4C1 and Mate1 were down-regulated, while Oat3, Mrp2, Mrp4, Mdr1-α, Bcrp were up-regulated. Pearson correlation analysis was used to analyze the correlation between transporters and Creatinine (Cr), OCT2 and MATE1 showed a strong negative correlation with Cr. In contrast, Mdr1-α exhibited a strong positive correlation with Cr. In addition, the pharmacokinetics of cimetidine, ganciclovir, and digoxin, which were the classical substrates for OCT2, MATE1 and P-glycoprotein (P-gp), respectively, have been studied. These results reveal that changes in serum creatinine can indicate changes in drug transporters in the kidney, and thus affect the pharmacokinetics of its substrates, providing useful information for clinical use. 相似文献
1000.
Zhao Wei Xinlei Zhang Huifang Nie Lin Yao Yanqin Liu Zhibing Zheng Qin Ouyang 《Molecules (Basel, Switzerland)》2022,27(3)
A family of novel efficient non-oxime compounds exhibited promising reactivation efficacy for VX and sarin inhibited human acetylcholinesterase was discovered. It was found that aromatic groups coupled to Mannich phenols and the introduction of imidazole to the ortho position of phenols would dramatically enhance reactivation efficiency. Moreover, the in vivo experiment was conducted, and the results demonstrated that Mannich phenol L10R1 (30 mg/kg, ip) could afford 100% 48 h survival for mice of 2*LD50 sarin exposure, which is promising for the development of non-oxime reactivators with central efficiency. 相似文献