Production of carbon soot with a high content of C60 and C70 fullerenes by electric arc

The effect of the parameters of the electric arc (helium pressure, current and voltage, clearance between electrodes) and of the peculiarities of the setup design (arrangement of electrodes, distance between the arc and the cooling surface, temperature of the soot condensation surface) on the yield of fullerenes has been studied. Conditions for producing soot with a C₆₀ and C₇₀ content up to 43% (toluene extract) have been found.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 805–809, May, 1994.The authors are grateful to N. G. Spitsyna and A. V. Dubovitskii for the determination of the content of C₆₀ and C₇₀ fullerenes in the extract.The work was financially supported by the Russian Foundation for Basic Research (Project 93-03-18705).     

槲寄生蛋白注射液细胞毒活性测定的MTT方法探讨

采用MTT比色法对体外培养的肿瘤细胞进行细胞毒作用实验，验证槲寄生蛋白注射液体外抗肿瘤效果．并且鉴定这种检测方法的有效性。实验结果表明槲寄生蛋白注射液有一定的体外抗肿瘤效果；MTT比色法是一种可用的体外细胞毒作用检测法，为新药品的开发提供了实验依据。     

高富勒烯的提取,分离和分析

采用二硫化碳重结晶富勒烯混合物或二硫化碳二次抽提烟灰以提取高富勒烯（ｈｉｇｈｅｒｆｕｌｅｒｅｎｅｓ，Ｃｎ，ｎ＞７０）。产物经高效液相色谱分析，高富勒烯的含量从１％分别提高到４％和６％；经激光飞行时间质谱证明，产物中除含主要成分Ｃ６０和Ｃ７０以外，还含有Ｃ７６、Ｃ７８、Ｃ８２、Ｃ８４以及更高碳原子的富勒烯。     

Adsorption separation of terpene lactones from Ginkgo biloba L. extract using glass fiber membranes modified with octadecyltrichlorosilane

In this study porous glass fiber membranes were modified by reaction with octadecyl-trichlorosilane to form C18 hydrophobic membranes. The contact angle and the CH2 vibration bands at 2855 and 2920 cm(-1) found by FTIR measurements verified the successful immobilization of C18 groups on the glass fiber membranes. The resulting C18 hydrophobic membranes were used to adsorb terpene lactones from crude Ginkgo biloba L. extracts. In batch adsorption processes, the modified C18 membranes exhibited a better adsorption performance than commercial C18 solid phase extraction adsorbents. Different desorption solvents were tested and ethyl acetate was found to preferentially desorb terpene lactones from the modified C18 membranes. In flow adsorption experiments at 1 mL/min, terpene lactone contents higher than 6 wt% (the standardized content) could be achieved in the elution step using ethyl acetate.     

Analysis of nitro-PAHs in diesel exhaust particulate extracts with multicolumn HPLC

Summary A method is described for the determination of nitrated polynuclear aromatic hydrocarbons (nitro-PAHs), in particular 1-nitropyrene, in diesel particulate extracts. The method employs a multidimensional HPLC (column switching) technique with final on-line peak identification by UV-VIS spectral comparison with standards. To achieve exceptional chromatographic selectivity for nitro-PAHs, a new pyrene butyric acid amide phase has been prepared which is capable of forming donor-acceptor complexes with them. With this technique it is possible to confirm the presence of 1-nitropyrene in the range 3–100 ng/mg on filter-collected diesel soot. Its utility was demonstrated with diesel exhaust extracts spiked with varying levels of 1-nitropyrene and proved to be highly selective.Parts of this work have been presented at the 15th International Symposium on Chromatography, Nürnberg, October 1984.Dedicated to Prof. J. F. K. Huber at the occasion of his 60th birthday.     

基于卡口上下文和深度置信网络的车辆轨迹预测模型研究

针对车辆轨迹预测中节点序列的时序特性和实际路网中的空间关联性,该文提出一种基于深度置信网络和SoftMax (DBN-SoftMax)轨迹预测方法.首先,考虑到轨迹在节点集合中的强稀疏性和一般特征学习方法对新特征的泛化能力不足,该文利用深度置信网络(DBN)较强的无监督特征学习能力,达到提取轨迹局部空间特性的目的;然后,针对轨迹的时序特性,该文采用逻辑回归的预测思路,用当前轨迹集在路网特征空间中的线性组合来预测轨迹;最后,结合自然语言处理领域中的词嵌入的思想,基于实际轨迹中节点存在的上下文关系,运用节点的向量集表征了节点间的交通时空关系.实验结果表明该模型不仅能够有效地提取轨迹特征,并且在拓扑结构复杂的路网中也能得到较好的预测结果.     

用超临界气体抽提方法研究抚顺烟煤的组成和结构——Ⅰ.抽出物的分离及GC、GC/MS分析

将抚顺烟煤用甲苯作溶剂,在半连续抽提装置上,于350℃、20MPa条件下,进行超临界气体抽提。抽出物先分离成油、沥青烯及前沥青烯三个族组份,再用离子交换树脂、硅胶柱色谱作进一步分离。GC和GC/MS的分析结果表明,油段分中存在正构烷烃(C_(13)—C_(31))、类异戊二烯化合物及长链烷基苯系列,这些化合物可提供抚顺烟煤的地球化学信息。     

Carob pod: A new substrate for citric acid production by Aspergillus niger

The production of citric acid from carob pod extract byA. niger in surface fermentation was investigated. A maximum citric acid concentration (85.5 g/L), citric acid productivity (4.07 g/L/d), specific citric acid production rate (0.18 g/g/d), and specific sugar uptake rate (0.358 g/g/d) was achieved at an initial sugar concentration of 200 g/L, pH of 6.5, and a temperature of 30°C. Other kinetic parameters, namely, citric acid yield, biomass yield, specific biomass production rate, and fermentation efficiency were maximum at pH 6.5, temperature 30°C, and initial sugar concentration 100 g/L. The external addition of methanol into the carob pod extract at a concentration up to 4% (v/v) improved the production of citric acid.     

Agaricus bisporus Crude Extract: Characterization and Analytical Application

In the present work crude Agaricus bisporus extract (ABE) has been prepared and characterized by its tyrosinase activity, protein composition and substrate specificity. The presence of mushroom tyrosinase (PPO3) in ABE has been confirmed using two-dimensional electrophoresis, followed by MALDI TOF/TOF MS-based analysis. GH27 alpha-glucosidases, GH47 alpha-mannosidases, GH20 hexosaminidases, and alkaline phosphatases have been also detected in ABE. ABE substrate specificity has been studied using 19 phenolic compounds: polyphenols (catechol, gallic, caffeic, chlorogenic, and ferulic acids, quercetin, rutin, dihydroquercetin, l-dihydroxyphenylalanine, resorcinol, propyl gallate) and monophenols (l-tyrosine, phenol, p-nitrophenol, o-nitrophenol, guaiacol, o-cresol, m-cresol, p-cresol). The comparison of ABE substrate specificity and affinity to the corresponding parameters of purified A. bisporus tyrosinase has revealed no major differences. The conditions for spectrophotometric determination have been chosen and the analytical procedures for determination of 1.4 × 10⁻⁴–1.0 × 10⁻³ M l-tyrosine, 3.1 × 10⁻⁶–1.0 × 10⁻⁴ M phenol, 5.4 × 10⁻⁵–1.0 × 10⁻³ M catechol, 8.5 × 10⁻⁵–1.0 × 10⁻³ M caffeic acid, 1.5 × 10⁻⁴–7.5 × 10⁻⁴ M chlorogenic acid, 6.8 × 10⁻⁵–1.0 × 10⁻³ M l-DOPA have been proposed. The procedures have been applied for the determination of l-tyrosine in food supplements, l-DOPA in synthetic serum, and phenol in waste water from the food manufacturing plant. Thus, we have demonstrated the possibility of using ABE as a substitute for tyrosinase in such analytical applications, as food supplements, medical and environmental analysis.     

Hepatoprotective Activity of Nelumbo nucifera Gaertn. Seedpod Extract Attenuated Acetaminophen-Induced Hepatotoxicity

The aim is to investigate the effect of lotus (Nelumbo nucifera Gaertn.) seedpod extract (LSE) on acetaminophen (APAP)-induced hepatotoxicity. LSE is rich in polyphenols and has potent antioxidant capacity. APAP is a commonly used analgesic, while APAP overdose is the main reason for drug toxicity in the liver. Until now, there has been no in vitro test of LSE in drug-induced hepatotoxicity responses. LSEs were used to evaluate the effect on APAP-induced cytotoxicity, ROS level, apoptotic rate, and molecule mechanisms. The co-treatment of APAP and LSEs elevated the survival rate and decreased intracellular ROS levels on HepG2 cells. LSEs treatment could significantly reduce APAP-induced HepG2 apoptosis assessed by DAPI and Annexin V/PI. The further molecule mechanisms indicated that LSEs decreased Fas/FasL binding and reduced Bax and tBid to restore mitochondrial structure and subsequently suppress downstream apoptosis cascade activation. These declines in COX-2, NF-κB, and iNOS levels were observed in co-treatment APAP and LSEs, which indicated that LSEs could ameliorate APAP-induced inflammation. LSE protected APAP-induced apoptosis by preventing extrinsic, intrinsic, and JNK-mediated pathways. In addition, the restoration of mitochondria and inflammatory suppression in LSEs treatments indicated that LSEs could decrease oxidative stress induced by toxic APAP. Therefore, LSE could be a novel therapeutic option for an antidote against overdose of APAP.