Histamine H4 Receptor Agonism Induces Antitumor Effects in Human T-Cell Lymphoma

The discovery of the human histamine H4 receptor (H4R) has contributed to our understanding of the role of histamine in numerous physiological and pathological conditions, including tumor development and progression. The lymph nodes of patients with malignant lymphomas have shown to contain high levels of histamine, however, less is known regarding the expression and function of the H4R in T-cell lymphoma (TCL). In this work we demonstrate the expression of H4R isoforms (mRNA and protein) in three human aggressive TCL (OCI-Ly12, Karpas 299, and HuT78). Histamine and specific H4R agonists (VUF8430 and JNJ28610244) significantly reduced cell viability in a dose-dependent manner (p < 0.05). The combined treatment with the H4R antagonist (JNJ7777120, 10 µM) reversed the effects of the H4R ligands. Importantly, we screened a drug repurposing library of 433 FDA-approved compounds (1 μM) in combination with histamine (10 μM) in Hut78 cells. Histamine produced a favorable antitumor effect with 18 of these compounds, including the histone deacetylase inhibitor panobinostat. Apoptosis, proliferation, and oxidative stress studies confirmed the antitumoral effects of the combination. We conclude that the H4R is expressed in TCL, and it is involved in histamine-mediated responses.     

Myo-Inositol Limits Kainic Acid-Induced Epileptogenesis in Rats

Epilepsy is a severe neurological disease characterized by spontaneous recurrent seizures (SRS). A complex pathophysiological process referred to as epileptogenesis transforms a normal brain into an epileptic one. Prevention of epileptogenesis is a subject of intensive research. Currently, there are no clinically approved drugs that can act as preventive medication. Our previous studies have revealed highly promising antiepileptogenic properties of a compound–myo-inositol (MI) and the present research broadens previous results and demonstrates the long-term disease-modifying effect of this drug, as well as the amelioration of cognitive comorbidities. For the first time, we show that long-term treatment with MI: (i) decreases the frequency and duration of electrographic SRS in the hippocampus; (ii) has an ameliorating effect on spatial learning and memory deficit associated with epileptogenesis, and (iii) attenuates cell loss in the hippocampus. MI treatment also alters the expression of the glial fibrillary acidic protein, LRRC8A subunit of volume-regulated anion channels, and protein tyrosine phosphatase receptor type R, all expected to counteract the epileptogenesis. All these effects are still present even 4 weeks after MI treatment ceased. This suggests that MI may exert multiple actions on various epileptogenesis-associated changes in the brain and, therefore, could be considered as a candidate target for prevention of epileptogenesis.     

Enantioselective esterification of (R,S)-2-(4-methylphenyl) propionic acid via Novozym 435: Optimization and application

This paper reports on the resolution of(R,S)-2-(4-methylphenyl) propionic acid(MPPA) enantiomers by enzymatic esterification in organic solvent. Novozym 435(CALB) has the best catalytic performance compared with other lipases. Of the alcohols screened, n-hexanol is the best acyl acceptor and gives the highest enzyme activity and enantioselectivity in n-hexane. Response surface methodology(RSM) was used to evaluate the influence of the factors, such as temperature, enzyme amount, substrate concentration and reaction time on the substrate conversion(c) and enantiomeric excess(ee). The correlation coefficient R~2 for enantiomeric excess and the conversion are 0.9827 and 0.9910, respectively, indicating that can accurately predict the experimental results. By simulation and optimization, the optimal conditions were obtained, involving 600 mmol·L~(-1) MPPA concentration(0.60 mmol), 850 mmol·L~(-1) hexanol concentration(0.85 mmol), 58 mg enzyme amount, 75 ℃ temperature and 4.5 h reaction time, respectively. Under the optimized conditions, the experimental values of conversion and enantiomeric excess were 89.34% and 97.84%, respectively, which are in good agreement with the model predictions.     

Highly efficient synthesis of(R)-1,3-butanediol via anti-Prelog reduction of 4-hydroxy-2-butanone with absolute stereoselectivity by a newly isolated Pichia kudriavzevii

(R)-1,3-butanediol is an important pharmaceutical intermediate, and the synthesis of(R)-1,3-butanediol using green biological methods has recently been of interest for industrial application. Here, a novel strain QC-1 that efficiently transforms 4-hydroxy-2-butanone to(R)-1,3-butanediol was isolated from soil samples. Based on morphological, physiological, and biochemical tests and 5.8 S-internal transcribed spacer sequencing, the strain was identified as Pichia kudriavzevii QC-1. The reaction conditions were optimized to 35 ℃, pH 8.0, rotation speed 200 rpm, and 6:5 mass ratio of glucose to 4-hydroxy-2-butanone. Evaluation of the effects of 4-hydroxy-2-butanone concentrations on yield and cell survival rate showed that 85.60 g·L~(-1) product accumulated, with an enantiomeric excess of more than 99%, when 30 g·L~(-1)4-hydroxy-2-butanone was added at 0, 10, and 30 h in a 3-L bioreactor. Thus, strain QC-1 showed excellent catalytic activity and stereoselectivity for the synthesis of(R)-1,3-butanediol from 4-hydroxy-2-butanone.     

高频直缝焊管用EMA-H电磁超声波探伤仪的研制

介绍了传统的压电超声波探伤存在的问题以及EMA-H电磁超声波探伤仪的工作原理、特点、工艺设备构成及工艺流程等。实际应用表明,采用EMA-H电磁超声波探伤仪对高频直缝焊管进行探伤,可靠性高,而且能对钢管焊缝、管体作全面的探伤检测。     

Delayed fluorescence spectroscopy and mechanism of the 730 nm component of chloroplast

Charge recombination in reaction center (RC) of photosystem II(PS II) is regarded as the location of 685 nm delayed fluorescence (DF). The mechanism of 730 nm component appearing in the DF spectrum for chloroplast was studied by various spectral analysis methods. Experimental results of the DF spectrum at different chloroplast concentration show that the intensity of peaks at 685nm and 730 nm ascends with the chloroplast concentration increasing when the concentration is relatively low. When the concentration increases to the level of 7.8μg/ml, a maximum intensity of the peak at 685 nm appears but the intensity of 730 nm peak still increases. The peak at 730 nm finally reaches a maximum intensity at the chloroplast concentration of 31.2 μg/ml while the intensity of the 685 nm peak has apparently fallen down. The results of absorption spectrum show that the ratios of A685 to A730 keep almost constant with the increasing of chloroplast concentration. Furthermore, the excitation spectrum for 730 nm fluorescence shows that the 685nm light has high excitation efficiency. These results indicate that the 730 nm component of DF spectrum is the fluorescence of chlorophyll in PS I RC excited by 685 nm DF. Meanwhile, this can be further verified by the invariability of DF spectrum at different delay time (1 second∼9 seconds). This research is supported by the National Natural Science Foundation of China (60378043), and supported by the Opening Foundation of the Key Laboratory of Opto-Electronic Technology and Intelligent Control (Lanzhou Jiaotong University), Ministry of Education (K04108)     

热负荷对R141b热力学排气系统自增压特性及排气损失的影响

为了研究低温推进剂在轨贮存技术所涉及的基本科学问题,在以R141b为气液相变储存介质的室温温区热力学排气系统（TVS）模拟装置上,进行了“漏热”功率分别为120、160和200 W的储箱压力控制实验研究。获得了TVS作用下的储箱增压特性,3种热负荷下自增压速率分别为6.43、12.92和18.05 kPa·h^-1。将采用TVS方法与定期直接放空法控制储箱压力产生的工质损失进行了对比,以其中热负荷120 W工况为例,采用TVS方法可减少工质损失79.3%。若是处于气液不分离的在轨微重力环境中,以直接放空时气体中夹带40%液体计,采用TVS方法可减少工质损失84.7%,验证了TVS方法在控制储箱压力方面的优越性。     

R23/R134a一级分凝和二级分凝自复叠喷射制冷循环性能理论分析

基于非共沸混合工质自复叠原理应用于喷射制冷循环的研究,对一级分凝和二级分凝自复叠喷射循环进行了理论分析,研究了使用R134a/R23非共沸混合工质时制冷剂的配比、冷凝温度和蒸发温度对两种循环性能的影响,结果表明：随着低沸点组分R23质量分数由0.10增至0.20,一级分凝循环喷射器压比在3.4附近变化,而二级分凝循环喷射器压比在1.8附近变化,两种循环COP均增大;随着冷凝温度由18℃升至23℃,一级分凝循环喷射器压比由3.242增至3.792,而二级分凝循环喷射器压比由1.860升至1.867,两种循环COP均降低;随着蒸发温度由-10℃降至-15℃,一级分凝循环喷射器压比由3.454降至2.832,而二级分凝循环喷射器压比由1.870降至1.840,两种循环COP均升高,并且在相同工况下,二级分凝循环COP远高于一级分凝循环;二级分凝循环在喷射器压比为1.8时,可获得-15℃温区的制冷温度。     

数码涡旋压缩机在多联空调系统中的应用

通过比较变频压缩机和数码涡旋压缩机的工作原理、性能及运行特点,数码涡旋压缩在多联空调系统中明显占有优势。采用新型环保制冷剂R410A在数码涡旋系统中运行,能效比高、更节能,是未来多联空调系统的发展方向。