1,5-二芳基-3-氯甲基硫代-1H-1,2,4-三唑的合成及其结构表征

1-芳酰基-3-苯氨基硫脲与二氯甲烷在无溶剂条件下反应合成了4种1,5-二芳基-3-氯甲基硫代-1H-1,2,4-三唑类化合物,产率为64%-74%.产物的结构通过红外光谱、核磁共振光谱和高分辨质谱进行了表征.     

NNAL模拟模板分子印迹聚合物的合成与固相萃取性能

以三种4-甲基亚硝胺-1-(3-吡啶基)-1-丁醇(NNAL)的结构类似物即4-(N-甲基-N-乙酰基)-1-(3-吡啶基)-1-丁醇、4-(N-甲基)-1-(3-吡啶基)-1-丁醇、1-(3-吡啶基)-1,4-丁二醇为模拟模板分子,甲基丙烯酸(MAA)为功能单体,通过自组装技术制备了对NNAL具有良好识别能力的印迹聚合物．通过X射线光电子能谱和红外光谱研究了NNAL和MAA之间的相互作用,结果表明NNAL和MAA可以通过氢键协同作用形成1:2型配合物．吡啶上的N和亚硝基中的O是形成氢键作用的两个选择性识别位点．XPS和IR进一步揭示出由4-(N-甲基-N-乙酰基)-1-(3-吡啶基)-1-丁醇制备得到的印迹聚合物对NNAL有最佳的识别性能．此外,实验研究了该聚合物作为固相萃取填料分离、净化NNAL的最佳条件．当采用水溶液上样,分别以0.5 mL水、1 mL甲苯、1 mL甲苯/二氯甲烷(9:1)、1 mL甲苯/二氯甲烷(4:1)淋洗,3￡1 mL甲醇洗脱时,NNAL在分子印迹固相萃取柱上的回收率达到93%．以尼古丁为竞争分子的选择性实验进一步证明该材料有很好的特异性识别能力．同时在不同加标水平尿液(500 pg/mL,1000 pg/mL,2000 pg/mL)的回收实验中,NNAL的回收率范围为87.2%～101.2%,精密度值均低于7.1%．     

恒能量同步荧光法快速同时测定蒽和9, 10-二甲基蒽

建立了蒽和9,10-二甲基蒽的同时恒能量同步荧光分析法。它们的恒能量同步荧光光谱和常规荧光光谱相比,分辨力明显提高。蒽和9,10-二甲基蒽的线性范围分别为0～2 μg·mL-1和0～5 μg·mL-1,检出下限分别为2.2 ng·mL-1和1.7 ng·mL-1, 相对标准偏差不大于2%。水样中蒽和9,10-二甲基蒽的回收率为85%～103％。该方法简便快速,无需预分离。     

分光光度法测定灌肠类肉制品中亚硝酸盐含量

研究了亚硝酸盐与N-1-奈乙二胺盐酸盐溶液的显色反应条件,在pH为2的弱酸条件下,亚硝酸盐与4-氨基苯磺酸重氮化后,再与N-1-奈乙二胺盐酸盐偶合形成紫红色偶氮染料,最大吸收波长位于545nm处,表观摩尔吸光系数ε为5.02×104L·mol-1·cm-1,所研究方法的亚硝酸盐含量在0-1.0μg/mL范围内服从比耳定律.该方法用于肉制品中亚硝酸盐含量的测定,加标回收率在91%-108%之间,相对标准偏差小于1.0%.该方法灵敏度高,操作简便快速,应用于北京某肉类加工厂生产的灌肠类肉制品中亚硝酸盐的残留量的测定,结果令人满意.     

紫外薄层色谱法分离C15H18N4SO2和C13H19N3SO4

采用紫外薄层色谱法在硅胶GF254板上分离N-{2-[(2,2-二氰基-乙烯基)-甲基-氨基]-丙基}-4-甲基-苯磺酰胺(C_(15)H_(18)N_4SO_2)和4-甲基-N-{2-[甲基-(2-硝基-乙烯基)-氨基]-丙基}-苯磺酰胺(C_(13)H_(19)N_3SO_4)二种有机物的方法。硅胶GF254板由0.27mol/L,pH=7的EDTA溶液修饰,避免了这两种样品与板上少量无机金属离子发生络合作用;展开剂为乙酸乙酯-石油醚-乙醇-37.5%氨水(体积比为10∶10∶1∶1)。C_(15)H_(18)N_4SO_2和C_(13)H_(19)N_3SO_4的Rf值分别为0.64和0.48。用紫外薄层色谱法分离C_(15)H_(18)N_4SO_2和C_(13)H_(19)N_3SO_4具有操作简单,灵敏,准确的特点。     

2-羟基-N-甲基乙酰苯胺的合成和表征

以N-甲基苯胺、氯乙酰氯、无水醋酸钠、甲醇等为原料,经乙酰化,酯化及酯交换反应合成了2-羟基-N-甲基乙酰苯胺,三步总收率为88.0%.N-甲基苯胺、氯乙酰氯在三乙胺的催化下,按n(C6H5NHCH3):n[ClCH2C(O)Cl]:n[N(C2H5)3]=1:1.05:1,经乙酰化反应得到2-氯代-N-甲基乙酰苯胺(I),收率为93.8%;(I)与无水醋酸钠在相转移催化剂四丁基溴化铵的存在下,按n(I):n(NaOAc)=1:1.2,经酯化反应合成了2-乙酰氧基-N-甲基乙酰苯胺(Ⅱ),收率为97.3%;(Ⅱ)与甲醇按n(Ⅱ):n(CH3OH)=1:10,在氢氧化钾的催化下,进行了酯交换反应得到2-羟基-N-甲基乙酰苯胺(Ⅲ),收率为96.4%.并利用红外、质谱和元素分析,对各产物进行了表征,确认了分子结构.     

2-三氟甲基吡啶的合成与光谱表征

以2-氯基吡啶为原料,合成2-溴吡啶(收率68%)和2-碘吡啶(收率56%);2-溴吡啶和2-碘吡啶与三氟乙酸钾反应,得2-三氟甲基吡啶(收率56%-72%).通过NMR和元素分析对产物的结构进行了表征.该合成路线的优点是原料易得,反应条件温和,收率较高,总收率为38%-42%.     

季铵盐型魔芋葡甘聚糖衍生物的合成、表征及生物学活性

以魔芋葡甘聚糖为载体,以硝酸铈铵作引发剂,用甲基丙烯酰氧乙基-十四烷基-二甲基溴化铵为活性单体进行接枝共聚反应制备季铵盐型魔芋葡甘聚糖衍生物。用核磁共振,红外光谱,DSC和激光粒度Zeta电位仪对接枝产物进行了表征和测定,用悬菌定量实验研究了其抗菌性能。结果表明：(1)甲基丙烯酰氧乙基-十四烷基-二甲基溴化铵通过其双键接枝到魔芋葡甘聚糖表面,接枝率随着季铵盐单体的用量增加而提高;(2)魔芋葡甘聚糖的零电位在pH 4.5,魔芋葡甘聚糖季铵盐衍生物的零电位在pH 9.9,季铵基的引入使其零电位发生了较大的位移;(3)所制备的魔芋葡甘聚糖季铵盐衍生物对大肠杆菌、金黄色葡萄球菌以及白色念珠菌在振荡作用15 min后,平均杀菌率分别为99.99％,99.99％和98.13％。     

甲硫氨酸与2,3-二氯-5,6-二氰-1,4-苯醌的荷移反应

用分光光度法研究了甲硫氨酸与2,3-二氯-5,6-二氰-1.4-苯醌(DDBQ)的荷移反应.实验表明,在pH=9.0三酸缓冲溶液中,在50℃水浴中加热30min,两者可形成稳定的1:1型的荷移络合物.此络合物的λmax343nm,表观摩尔吸光系数ε=1.4×104L·mol-1·cm-1,在0.4-15.0μg/mL范围内符合比耳定律,回收率在98.24%-101.1%,相对标准偏差为0.89%-0.95%.     

吖啶酯标记的化学发光免疫分析优化参数评价

以睾酮-3-羧甲氧基肟-牛血清白蛋白为免疫原,免疫家兔产生抗血清,10-甲基吖啶-9-羧酸[4-(N-睾酮-3-羧甲氧基肟)-氨乙基]苯酯为示踪化合物,采用平衡法建立睾酮化学发光免疫分析,数据用四参数Logistic函数处理。方法学考核标准曲线稳定,R为0.9967;ED50为82.15ng/L;批内和批间CV分别为5.78%和3.3%;平均回收率为107.28%;可测范围为19.3～264.6ng/L,与雌酮、雌二醇、雌三醇和孕酮的交叉反应率均小于1.35%;非特异结合率为9.64%.“桥效应”分析表明同位点、“桥”结构相同亲和力最大.     

High frequency shear ultrasonic properties of water/sorbitol solutions

Dynamic viscoelastic properties (G′ and G′′), ultrasonic shear velocity and attenuation were measured for aqueous solutions of sorbitol at 5 MHz. For pure sorbitol, the shear ultrasonic velocity reached 1470 m s⁻¹ with a density of 1500 kg m⁻³, consequently leading to a high acoustical impedance compared with “classical” polymers (polystyrene, nylon, polyethylene, Teflon, etc.). We demonstrate that this surprisingly high shear ultrasonic velocity for a viscoelastic material was due to the fact that the glass transition begins at a concentration above 85% of sorbitol in water. Hence, pure sorbitol is an ideal coupling material for high frequency shear experiments.     

Cryopreservation of the australian species Macropidia fuliginosa (Haemodoraceae) by vitrification

Somatic embryos were used to develop a cryopreservation protocol for Macropidia fuliginosa, a commercially-important species endemic to the south-west of Western Australia. Somatic embryos were allowed to develop from embryogenic callus for three weeks on an kinetin medium prior to processing. These were transferred and cultured on a agar solidified basal medium supplemented with 0 to 0.6 M sorbitol for 2 d prior to incubation in Plant Vitrification Solution Two (PVS2). Following this, embryos were then washed in 1 M sucrose solution (treated controls) or cooled in liquid nitrogen (LN). Cooled embryos were then warmed and washed in sucrose solution. Highest survival for cooled treatments (67.3%) was achieved by preculture with 0.4 M sorbitol, then incubation in PVS2. Further experimentation varying pre-culture duration (2 or 3 d) and incubation on either glycerol (0.8 M) or sorbitol (0.4 M) indicated that very high survival (90.6%) of embryos was achievable by adopting a 2 d preculture period on 0.8 M glycerol. The phenotype and growth rates of plants obtained using this protocol were similar to those of parent plants. This optimised procedure was then applied to tissue culture-derived shoot apices of the same clone also resulting in a high survival rate (84.4%).     

Study of adsorption of bovine serum albumin to Langmuir-Blodgett film coated surfaces using work of adhesion as a tool

This work reports on the use of rate of change of work of adhesion (ΔW) as a tool to study adsorption of bovine serum albumin (BSA) to glass and Langmuir-Blodgett film of dihexadecyl phosphate (DHP) and dioctadecyl dimethyl ammonium bromide (DOMA) coated surfaces. Pure BSA and BSA with additives - sorbitol and urea - have been adsorbed to bare glass surfaces and DHP and DOMA coated surfaces. The results suggest that an increase in ΔW with time indicates promotion of adsorption while a decrease indicates hindered adsorption. Further adsorption of BSA was most effective on DHP coated surface compared with bare glass and DOMA coated glass. In case of mixtures of BSA with urea and sorbitol, BSA + urea showed hindered adsorption while adsorption of BSA + sorbitol was efficient for all substrates.     

Cryopreservation of carrot (Daucus carota l.) cell suspensions and protoplasts by vitrification

Carrot cell suspensions and protoplasts were successfully cryopreserved by vitrification. Cells were precultured in liquid Murashige and Skoog medium containing 0.175 M sucrose for 3 d and then in liquid MS medium containing 0.4 M sorbitol for 1 d. After loading of the precultured carrot cells in 25 % PVS2 at room temperature for 5 min and treatment with 100 % PVS2 at 0 degrees C for 7.5 min, they were quenched in liquid nitrogen. Optimal survival was 83.3 % (based on the triphenyl tetrazolium chloride reduction assay) following warming and unloading. Recovered cells retained the ability to regenerate plantlets in vitro. In the case of vitrification of protoplasts isolated from carrot cell suspensions, the optimal loading and dehydration durations were 5 min in 25% PVS2 and 3 min 100 % PVS2 respectively. Survival of 47 % of the untreated control (based on the FDA-PI (fluorescein diacetate-propidium iodide) staining) was achieved after cryopreservation.     

Oxygen self-diffusion in single-crystal MgO: secondary-ion mass spectrometric analysis with comparison of results from gas–solid and solid–solid exchange

Self-diffusion coefficients for ¹⁸O in single-crystal MgO have been determined from a novel specimen comprising an epitaxial layer of high-purity Mg¹⁸O upon a single crystal substrate of normal MgO. Heating the specimen in air produced a gas–solid exchange gradient at the sample surface as ¹⁸O in the epitaxial layer exchanged with ¹⁶O in air. A solid–solid interdiffusion gradient was produced between the substrate crystal and the ¹⁸O-enriched epitaxial layer. SIMS analysis of gas–solid exchange gradients prepared in the temperature range 1000–1650 °C provided diffusion coefficients that could be described as

Full-size image

. Interdiffusion gradients produced by annealing at 1100 and 1200 °C yielded the self-diffusion coefficients that were comparable to those obtained from gas–solid exchange, indicating that the surface exchange reaction is fast enough. The results are interpreted in terms of a defect model in which oxygen diffusion occurs by an interstitial type of defect as a result of suppression of anion vacancy concentration by large concentrations of extrinsic cation vacancies.     

The influence of temperature (20-1000 °C) on binary mixtures of solid solutions of CH3COOLi·2H2O-MgHPO4·3H2O

Thermally induced phase transitions (20-1000 °C) in the substrates and binary mixtures of CH₃COOLi·2H₂O(1)-MgHPO₄·3H₂O(11) have been analysed. Changes taking place on dehydration and thermal dissociation of binary mixtures prepared with percent molar ratios of 90-10% were studied by differential thermal analysis (TG, DTG, DTA), IR-spectroscopy and WAXS.The above-mentioned substrates changed their structure when heated for 1 h at 500 or 1000 °C. CH₃COOLi·2H₂O(1) (ID: 23-1171) changed the structure at 500 °C to that of Li₂CO₃ (ID: 22-1141), while at 1000 °C the structure was impossible to analyse as the compound reacted both with porcelain and with platinum (crucible materials). MgHPO₄·3H₂O(11) (Newberyite, ID: 35-780, 19-762) changed its structure at 500 °C to amorphous phase and at 1000 °C to Mg₂P₂O₇ (ID: 32-626).The following compounds were assayed in the respective binary mixtures heated at 500 °C for 1 h: 70% (1)-30%(11): LiMgPO₄ (ID: 18-735), MgO (ID: 4-829); 50%(1)-50%(11): LiMgPO₄ (ID: 18-735), Li₃PO₄ (ID: 25-1030); 30%(1)-70%(11): LiMgPO₄ (ID: 32-574); binary mixtures heated at 1000 °C contained the following compounds: 70%(1)-30%(11): LiMgPO₄ (ID: 32-574,18-735), Li₃PO₄ (ID: 15-760,25-1030), MgO (ID: 4-829); 50%(1)-50%(11): LiMgPO₄ (ID: 32-574, 18-735), MgO (ID: 4-829); 30%(1)-70%(11): LiMgPO₄ (ID: 18-735, 32-574), Mg₂P₂O₇ (ID: 22-1152, 8-38), Li₄SiO₄ (37-1472).     

碱助剂促进Ni基催化剂氢解山梨醇制备二元醇

采用逐步湿浸渍的方法制备了一系列含有不同载体和碱促进剂的Ni基催化剂用于生物质基平台化合物山梨醇的氢解反应. 通过反应对载体和碱促进剂进行了筛选和组分含量的优化,碱性促进剂的引入不仅增强了催化剂的碱性,而且通过Ni²⁺和碱促进剂的强相互作用提高了Ni在催化剂上的分散性;10%Ni/10%La₂O₃/ZrO₂表现出了非常高的氢解活性和较好的二元醇(乙二醇和1,2丙二醇)选择性,金属Ni和碱促进剂La₂O₃之间的协同作用机理对于山梨醇选择性氢解制备二元醇影响显著. 在优化的反应条件下,山梨醇达到100%的转化并且有超过48%的二元醇产率. 研究中对催化剂进行了XRD、BET、H₂-TPR和CO₂-TPD表征,用于分析催化剂结构性能. 通过对山梨醇氢解以及中间产物动力学曲线的研究,得出多元醇氢解活性与所含羟基数正相关,产物的最终分布是氢解动力学平衡的最终结果.     

PEDOT:PSS薄膜的山梨醇掺杂对光电池性能的影响

采用共混-旋涂技术在ITO导电玻璃上制备出经山梨醇掺杂的PEDOT:PSS导电膜,将所制得的薄膜作为空穴传输层用于有机太阳能电池研究.通过对比分析掺杂前后光电池暗电流曲线与光电流曲线的变化,考察了山梨醇掺杂对器件光伏性能的影响,并就其中的影响机理进行了讨论分析.结果表明,山梨醇的加入,可以明显提高光电池的短路电流,填充因子以及能量转换效率.较未掺杂器件,8wt %山梨醇掺杂条件下,器件短路电流由8.82 mA/cm²增加至11.27 mA/cm²,FF由0.43 关键词： PEDOT:PSS薄膜 山梨醇 有机太阳能电池 性能     

Imaging of (13)C-labeled glucose and sorbitol in bovine lens by (1)H-detected (13)C nuclear magnetic resonance spectroscopy

Bovine lenses were incubated in a solution containing [1-(13)C]glucose (50 mM) for 1, 2 and 4 days. Spectroscopic images of [1-(13)C]glucose and [1-(13)C]sorbitol were constructed using (1)H-detected gradient-enhanced heteronuclear multiple-quantum coherence (GE-HMQC) in a 2.0-tesla magnetic field. Accumulations of [1-(13)C]glucose and [1-(13)C]sorbitol were mainly observed at the periphery of the lens. Their distributions corresponded to the cortex. (1)H-detected (13)C nuclear magnetic resonance (NMR) spectroscopic imaging by GE-HMQC successfully demonstrated the distribution of [1-(13)C]glucose and [1-(13)C]sorbitol at the periphery of bovine lenses.     

Comparison of three techniques for cryopreservation and reestablishment of long-term Gentiana tibetica suspension culture

Cryogenic storage of cell suspensions allows long-term maintenance of cultures. The main purpose of the study was to develop a successful cryogenic protocol for 10-year-old embryogenic cell suspensions of G. tibetica. We examined three techniques of freezing: (I) controlled-rate cooling with various cryoprotectants (0.1-0.5 M DMSO, 0.5-1.0 M sucrose, 0.5-1.0 M glycerol, 0.25-1.0 M proline) or preculture with 0.4 M sorbitol and cryoprotectants (0.065-0.1 M DMSO, 0.2-0.8 M proline), (II) vitrification (PVS2) and (III) encapsulation. Cell viability was assessed by the TTC test and biomass increase. After controlled-rate cooling the majority of cells were lethally damaged, with only 3% viability observed. Vitrification and encapsulation approaches were more effective, assuring high levels of post-thaw viability ca. 85% and 7%, respectively. The encapsulation procedure gave faster recovery of the culture suspension than did vitrification, and ensured culture homogeneity and embryogenic competence.