芥兰营养生理的研究：Ⅱ.氮钾营养对芥兰生长和菜苔产量与品质的...

试验设N_1,K_1,N_1K_1,N_2K_1,N_1K_2和N_2K_2六个处理。结果表明,K_1处理菜薹的可溶性糖、还原糖和抗坏血酸的含量最高,而蛋白质含量最低,其植株生长不良,菜薹重最小。N_1处理菜薹的可深糖含量比N_1K_1,N_2K_1和N_2K_2较高,而比N_1K_2低,其蛋白质含量比NK配合各处理低,但抗坏血酸含量比N_1K_1和N_2K_2两处理较高,而与N_1K_2和N_2K_1两处理差异不大。N_1处理植株生长和菜薹重比K_1处理较好,而比NK配合各处理差。NK配合各处理中,以N_1K_2处理的植株生长和菜薹产量最好,菜薹的营养品质较佳。     

Heterodetic bicyclic decapeptide cyclo (Glu1 -Leu2 -Pro3-Gly4-Ser5-Ile6-Pro7-Ala8) cyclo-(1γ-5β) Phe9-Gly10

Bycyclic peptides are useful model molecules that can mimic the constrained local folding of a great number of natural peptides and proteins, such as ionophoric peptides, enzyme active site, and ligand-receptor active site. The synthesis of the bicyclic title compound with the liquid phase method is described with experimental details. Of particular interest is the heterodetic closure of the second ring. The peptide showed a complexing activity with metal cations like Ba²⁺, Ca²⁺, and Mg²⁺ . The free bicyclic peptide conformation in solution has been studied by means of NMR spectroscopy and a plausible structure model worked out with model building on NMR constraints is proposed.     

Protective effects and mechanism of tetramethylpyrazine against lens opacification induced by sodium selenite in rats

Tetramethylpyrazine (TMP), extracted from the Chinese herbal medicine Ligusticum wallichii franchat (chuan xiong in Chinese), is a potent anti-free radical and calcium antagonist. Correspondingly, two important hypotheses in the causation of cataracts are free radical toxicity and calcium ion overload. In this study we investigated the effect of TMP on lens opacification induced by sodium selenite in rats, addressing the potential of TMP eye drops to prevent and treat cataracts. Results showed that the extent of lens opacification in the untreated Normal Control group (NC group) was significantly less than that of selenite-injected untreated rats (MC group) on days 3, 5, 7 and 10 (p < 0.001), while TMP treated selenite-injected rats (TMP group) had less lens opacification than the MC group on days 3, 5, 7 and 10 (p < 0.05). Compared with the NC group, the MC group had significantly decreased activity of super-oxide dismutase (SOD), glutathione peroxidase (GSH-PX) and catalase (CAT) and significantly elevated malondialdehyde (MDA) and calcium ion content (p < 0.001). Compared with the MC group, the activity of (SOD), (GSH-PX) and (CAT) were significantly higher while (MDA) and calcium ion levels were significantly lower in the TMP group at all time points (p < 0.01). The findings demonstrate that the selenite-induced cataract rat models were successfully built and the TMP eye drops can delay lens opacification induced by sodium selenite in rats. The mechanism by which TMP preserves lens transparency from selenite treated animals is associated with the lenses’ ability to maintain normal levels of activity of SOD, GSH-PX and CAT and normal concentrations of MDA and calcium ion.     

Effects of propranolol pretreatment on cerebral blood flow, oxygen uptake and catecholamines during metabolic acidosis following E. coli endotoxin in dogs

After an intravenous injection of E. coli endotoxin in dogs a decrease in cerebral blood flow (CBF) and an increase in cerebral metabolic rate of oxygen (CMRo₂) have been shown to occur. In metabolic acidosis following endotoxin CMRo₂ increased with decreasing pH. A possible explanation for the increased CMRo₂ after endotoxin and metabolic acidosis seems to be a damage of the blood-brain barrier (BBB) by endotoxin. This gives possibilities for a leakage of hydrogen ions and circulating monoamines from the blood to the brain, thus affecting the cerebral blood flow and metabolism.
The effects of an E. coli endotoxin injection on CBF and CMRo₂ during metabolic acidosis and P-adrenoceptor blockade were studied in eight anaesthetized dogs. All the dogs were pretreated with propranolol (PPL), per os 12.5 mg . kg^-1 twice a day for one week. Metabolic acidosis (pH 7.01–7.30) was achieved by an intravenous infusion of hydrochloric acid. Endotoxin E. coli lipopolysaccharide O 111:B 4 was given as an intravenous injection of 1 mg . kg^-1 bodyweight over a 5 min period. Another five animals, published earlier, with the same experimental protocol but without PPL, constituted a control group.
After endotoxin no increase in CMRo₂ or CBF was observed with increasing acidosis in the PPL-group. In the control group, after endotoxin, both CBF and CMR02 increased with decreasing pH. This resulted in a significant difference in both CBF and CMRo₂ between the groups in the pH range 7.01—7.15.
The present results indicate that the increase in CMRo₂ and CBF with metabolic acidodis in endotoxinaemia is mediated via P-adrenoceptors.     

活性碳纤维对NO2气体动态吸附研究

为探讨粘胶基活性碳纤维（ＡＣＦ）对ＮＯ２气体的动态吸附，考察了ＮＯ２浓度、流速、湿度、温度及ＡＣＦ再生次数对吸附效率的影响。结果表明：ＮＯ２在低浓度下，ＡＣＦ能长时间高效工作；流速增加，穿透时间缩短，但穿透吸附量变化不明显；湿度增加，穿透时间缩短，穿透吸附量降低；温度升高、ＡＣＦ再生次数增加，穿透时间缩短，穿透吸附量及饱和吸附量均降低。证明ＡＣＦ对ＮＯ２的吸附以物理吸附为主，但存在一定程度的化学吸     

GC-MS法测定冰硼含片中冰片的含量

目的:建立以气相色谱-质谱联用技术测定冰硼含片中冰片含量的方法。方法:色谱柱为DB-5型石英毛细管(30m×0.32mm×0.25μm),样品用乙醚超声提取,采用选择离子监测(SIM)法定量。结果:冰片检测浓度在10.0~500.0μg.mL-1范围内与峰面积积分值呈良好的线性关系(r=0.999 9);平均加样回收率为98.55%,RSD=1.13%(n=6);最低检测限为10pg。结论:本方法简便、快速,结果准确,可用于冰硼含片的质量控制。     

Data mining of NCI's anticancer screening database reveals mitochondrial complex I inhibitors cytotoxic to leukemia cell lines

Mitochondria are principal mediators of apoptosis and thus can be considered molecular targets for new chemotherapeutic agents in the treatment of cancer. Inhibitors of mitochondrial complex I of the electron transport chain have been shown to induce apoptosis and exhibit antitumor activity. In an effort to find novel complex I inhibitors which exhibited anticancer activity in the NCI's tumor cell line screen, we examined organized tumor cytotoxicity screening data available as SOM (self-organized maps) (http://www.spheroid.ncifcrf.gov) at the developmental therapeutics program (DTP) of the National Cancer Institute (NCI). Our analysis focused on an SOM cluster comprised of compounds which included a number of known mitochondrial complex I (NADH:CoQ oxidoreductase) inhibitors. From these clusters 10 compounds whose mechanism of action was unknown were tested for inhibition of complex I activity in bovine heart sub-mitochondrial particles (SMP) resulting in the discovery that 5 of the 10 compounds demonstrated significant inhibition with IC50's in the nM range for three of the five. Examination of screening profiles of the five inhibitors toward the NCI's tumor cell lines revealed that they were cytotoxic to the leukemia subpanel (particularly K562 cells). Oxygen consumption experiments with permeabilized K562 cells revealed that the five most active compounds inhibited complex I activity in these cells in the same rank order and similar potency as determined with bovine heart SMP. Our findings thus fortify the appeal of mitochondrial complex I as a possible anticancer molecular target and provide a data mining strategy for selecting candidate inhibitors for further testing.     

脂肪族聚酯与高氯酸锂络合物的结构与导电性

本文通过酯交换反应合成了一系列脂肪族聚丁二酸酯,对他们的结构和性能作了表征。发现聚酯存在多晶现象,其熔点有奇偶性变化规律。探索了由此系列聚酯与高氯酸锂形成的固体电解质的结构和离子导电性。无机盐的加入提高了电解质的玻璃化温度但降低了聚酯的熔点及结晶度。聚酯电解质的晶体类似于聚酯,其无机盐主要溶解于聚酯的无定形区域。聚酯系列电解质的导电率也有偶奇效应,与熔点变化相反;熔点高的电解质导电率低,熔点低的电解质导电率高。电解质的导电率随温度改变而变化,在室温下电解质的导电率可达10~(-6)s/cm。高分子链上侧基的引入将大大降低电解质的导电性。     

兔眼植入氟—肝素表面修饰人工晶状体表面细胞计算机图像分析

目的：探讨作者研制的氟-肝素表面修饰人工晶状体（F-HSM IOL）的生物相容性。方法：F-HSM IOL及PMMA人工晶状体（PMMA IOL）各32枚植入兔眼。利用计算机图像分析仪对人工晶状体表面细胞构成、各种细胞平均面积、细胞总面积覆盖率和细胞密度进行分析。结果：F-HSM IOL及PMMA IOL表面细胞增以巨噬细胞为主。F-HSM IOL组各种细胞平均面积小于PMMA IOL组,细胞总面积覆盖率和细胞密度均低于PMMA IOL,两组有显著差别,P＜0.05。结论：氟-肝素表面修饰人工晶状体有较好的生物相容性。