天然紫杉烷类化合物的核磁共振氢谱特征

在系统分析天然紫杉烷类化合物核磁共振氢谱的基础上，对具有不同骨架类型的天然紫杉烷类二萜化合物的核磁共振氢谱的特征进行了总结, 提供了部分不同类型的紫杉烷类化合物的核磁共振氢谱图. 这些¹H NMR特征对于紫杉烷类化合物的结构确定非常有益.     

Dynamic synovial fibroblasts are modulated by NBCn1 as a potential target in rheumatoid arthritis

Rheumatoid arthritis (RA) is an autoimmune disease characterized by aggressive fibroblast-like synoviocytes (FLSs) and pannus formation. Various therapeutic strategies have been developed against inflammatory cytokines in RA in recent decades. Based on the migratory features of FLSs, we examined whether modulation of the migratory module attenuates RA severity. In this study, inflamed synovial fluid-stimulated FLSs exhibited enhanced migration and migratory apparatus expression, and sodium bicarbonate cotransporter n1 (NBCn1) was identified in primary cultured RA-FLSs for the first time. The NBC inhibitor S0859 attenuated the migration of FLSs induced with synovial fluid from patients with RA or with TNF-α stimulation. Inhibition of NBCs with S0859 in a collagen-induced arthritis (CIA) mouse model reduced joint swelling and destruction without blood, hepatic, or renal toxicity. Primary FLSs isolated from the CIA-induced mouse model also showed reduced migration in the presence of S0859. Our results suggest that inflammatory mediators in synovial fluid, including TNF-α, recruit NBCn1 to the plasma membrane of FLSs to provide dynamic properties and that modulation of NBCn1 could be developed into a therapeutic strategy for RA.Subject terms: Chemotaxis, Bone, Ion channel signalling, Rheumatoid arthritis, Drug development     

Thermodynamic equilibrium between locally excited and charge-transfer states through thermally activated charge transfer in 1-(pyren-2′-yl)-o-carborane

Reversible conversion between excited-states plays an important role in many photophysical phenomena. Using 1-(pyren-2′-yl)-o-carborane as a model, we studied the photoinduced reversible charge-transfer (CT) process and the thermodynamic equilibrium between the locally-excited (LE) state and CT state, by combining steady state, time-resolved, and temperature-dependent fluorescence spectroscopy, fs- and ns-transient absorption, and DFT and LR-TDDFT calculations. Our results show that the energy gaps and energy barriers between the LE, CT, and a non-emissive ‘mixed’ state of 1-(pyren-2′-yl)-o-carborane are very small, and all three excited states are accessible at room temperature. The internal-conversion and reverse internal-conversion between LE and CT states are significantly faster than the radiative decay, and the two states have the same lifetimes and are in thermodynamic equilibrium.

Reversible conversion between excited-states is key to many photophysical phenomena. We studied the equilibrium between LE and CT states by time-resolved and temperature-dependent fluorescence, fs- and ns-transient absorption, and LR-TDDFT calculations.     

Rapid Detection of Five Estrogens Added Illegally to Dietary Supplements by Combining TLC with Raman Imaging Microscope

Estrogens added illegally to dietary supplements are hazardous to human health. Traditional detection and analysis methods have many limitations, and we have developed an assay that combines thin-layer chromatography with Raman imaging microscopy (TLC-RIM). The five estrogens (estrone, estradiol, estriol, ethinyl estradiol, and diethylstilbestrol) were initially separated by TLC, then detected by area scanning Raman imaging with a 532 nm laser under a microscope. Raman spectra were obtained for each estrogen, which were used for detecting estrogen illegally added to botanical dietary supplements. The LOD of each estrogen was 0.4, 1.0, 0.8, 0.2, and 0.2 mg/mL, respectively. The matrix in the real sample did not interfere with the detection of estrogens. The method was fast, sensitive, stable, specific, and reliable.     

The Potential Antidepressant Action of Duloxetine Co-Administered with the TAAR1 Receptor Agonist SEP-363856 in Mice

Here, we explored the possible interaction between duloxetine and SEP-363856 (SEP-856) in depression-related reactions. The results showed that oral administration of duloxetine showed powerful antidepressant-like effects in both the forced swimming test (FST) and the suspension tail test (TST). SEP-856 orally administered alone also exerted an antidepressant-like effect in FST and TST, especially at doses of 0.3, 1, and 10 mg/kg. In addition, duloxetine (15 mg/kg) and SEP-856 (15 mg/kg) both showed antidepressant-like effects in the sucrose preference test (SPT). Most importantly, in the above experiments, compared with duloxetine alone, the simultaneous use of duloxetine and SEP-856 caused a more significant antidepressant-like effect. It is worth noting that doses of drug combination in FST and TST did not change the motor activities of mice in the open-field test (OFT). Thus, duloxetine and SEP-856 seem to play a synergistic role in regulating depression-related behaviors and might be beneficial for refractory depression.     

A Simple Hydrothermal Method for the Growth of ZnO Crystals

ZnO microstructures have been grown from zinc chloride (ZnCl₂) and ammonia solution at 100 °C for 1 – 24 hours. X‐ray diffraction, scanning electron microscope and field‐emission scanning microscope were utilized to investigate the structural properties and morphology of the ZnO crystals. Structural investigations show that phase‐pure hexagonal structure ZnO has been successfully synthesized, and the hexagonal structure ZnO can be achieved in solutions with an appropriate range of concentrations. Under our experimental conditions, several different morphologies of ZnO structures were obtained, including flower‐like and bar flower‐like. The relationship between the morphology and experimental conditions are discussed.     

实现冷原子或冷分子囚禁的双层光阱列阵

提出了一种新颖的实现冷原子或冷分子囚禁的双层光阱方案,它由二元π相位板列阵和会聚透镜列阵所组成,用平面光波通过此光学系统时将在透镜焦平面两侧形成双层光阱.介绍了产生双层光阱的基本原理,分析了光阱光强分布、强度梯度等与光学系统参数间的关系,研究了双层光阱囚禁原子(或分子)的光学偶极势和自发散射速率(包括瑞利散射和拉曼散射)等.该方案不仅可用于多样品原子(或分子)的光学囚禁及全光型玻色一爱因斯坦凝聚(BEC),而且可用于制备新颖的双层2D光学晶格.     

一种蓝色聚合物激光材料

聚合物作为一种有机发光材料,由于在平板显示和光电子器件中的良好应用前景而受到广泛研究［１～２］．近年来,一个重要进展是在聚合物中观测到了受激发射（简称Ｐｏｌｙ－ｍｅｒ激光）现象［３～６］．Ｐｏｌｙｍｅｒ激光最早是在溶液中实现的［３～４］．作为一种新型...     

代际流动性的地区差异及影响因素—来自中国的微观证据

代际流动性是测度社会不平等的重要指标,区域发展不平衡则是中国的客观现实。运用人口普查数据和中国城市年鉴,可发现中国现阶段代际流动性的三个特征：（1）全国层面的代际收入弹性为0.673。（2）代际流动性呈现出显著的地区及城市差异,沿海、北方的代际流动性明显高于内陆及南方。代际收入弹性最低的省会城市是天津（0.107）,最高的是江西南昌（0.686）;地级市分别是山东莱芜（0.124）和云南丽江（0.76）。（3）具有以下特征的地区具有更高的代际流动性：沿海及经济发达地区,高校更多、中小学教育投入更多的地区,非少数民族聚集地,革命老区。从微观机理上分析代际流动性的地区差异,可以为中国区域平衡发展政策提供理论依据。     

Optical pattern simulations for closed cylinders of liquid crystals

Abstract

Optical patterns for the polarizing microscope textures of closed cylinders of liquid crystals (CCLCs) are studied by the Jones vector formulation. The simulated director configuration diagram of a CCLC with normal orientation at the walls contains four kinds of stable director configurations. The resulting texture under some approximations depends only on phase shifts. The patterns are characterized by dark brushes that coincide with the directions of the crossed polarizers. Additionally, there are concentric circle fringes. For the ring defect structure, the centre region of the cylinder exhibits a black extinction. However, this is not distinguishable as between the hyperbolic and radial structures for both the point and the ring defect patterns. Comparing the observed patterns with the simulated ones, we find that the dark cross brushes and the centre black extinction of simulated patterns are similar to those that are observed. However, the concentric circle fringes of the observed pattern are not in accordance with the simulated pattern.