复方二精灵抗老年性痴呆的药理实验研究

目的 :研究复方二精灵 (2JL)对谷氨酸 (Glu)及过氧化氧 (H2 O2 )引起的离体培养神经细胞损伤的保护作用和整体抗痴呆作用。方法 :运用体外原代胚胎大鼠皮层神经细胞培养技术建立皮层神经细胞损伤的模型 ,观察服用了 2JL的兔血清对神经细胞的生长发育、细胞组织形态学变化以及其他有关生化指标的影响 ;对急性不完全性缺血缺氧大鼠脑组织乳酸 (LA)含量、脑组织形态学的影响 ;对三氯化铝所致拟痴呆小鼠的学习记忆能力、脑组织超微结构的影响等。结果 :服药血清 2JL可拮抗Glu介导的神经兴奋性毒作用和对H2 O2 引起的离体培养神经细胞损伤有不同程度的保护作用 ,见神经细胞存活率明显提高 ,LDH漏出减少、细胞膜LPO含量降低、GSH PX活性升高 ;2JL能明显降低缺血缺氧大鼠脑组织LA含量 ,明显提高拟痴呆小鼠的脑重系数、学习记忆能力 ;改善脑组织超微结构的变化 ,使神经元变性及细胞肿胀情况减轻 ,管周间隙减小。结论 :结果提示 ,2JL具有明显的保护脑细胞而发挥抗老年痴呆作用。

野油菜黄单胞菌中烯脂酰ACP还原酶的功能鉴定

烯脂酰ACP还原酶是细菌脂肪酸合成的关键酶之一.本研究通过生物信息学分析发现,野油菜黄单胞菌Xanthomonas campestris(Xcc)8004基因组中XC_0119(Xccfab V)注释为反-2-烯脂酰Co A还原酶基因.但其编码产物与铜绿假单胞菌的烯脂酰ACP还原酶Fab V具有较高的同源性,并含有相同的催化活性中心Tyr-(Xaa)8-Lys序列.用携带Xccfab V的质粒载体互补大肠杆菌fab I温度敏感突变株JP1111,转化子能在42℃生长,表明Xccfab V能遗传互补大肠杆菌fab I突变.体外重建脂肪酸合成反应表明,Xcc Fab V能催化不同链长的烯脂酰ACP还原为脂酰ACP,且催化活性不受三氯森抑制.遗传学研究表明,Xccfab V是必需基因,不能获得Xccfab V基因敲除突变株.将携带大肠杆菌fab I的外源质粒导入野生菌后,可敲除染色体上的fab V基因,获得的替换突变株生长特性和脂肪酸组成未发生显著变化,但替换突变株对三氯森敏感.上述结果证实,野油菜黄单胞菌fab V是必需基因,编码烯脂酰ACP还原酶,参与脂肪酸从头合成反应,且Fab V是Xcc对三氯森耐受的根本原因.

Feasibility of Using Trichloroacetic Acid Soluble Siliconas a Diagnostic Index of Silicon Deficiency in Rice

Pot experiments and field trials were conducted to investigate the changes in trichloroacetic acid (TCA) soluble silicon (Si) in the leaves of rice (Oryza sativa L.) and to examine the feasibility of using TCA-soluble Si content as an index for diagnosing Si deficiency. The TCA-soluble Si content was significantly higher in the leaves of both Si-treated and -untreated rice at the elongation stage compared with that at tillering stage. It was also higher in the Si-treated plants than in the controls throughout the whole growth period.However, whether dressed at elongation or booting stage, silicon fertilizer resulted in a significant increase in TCA-soluble Si one week to ten days after application. The same was true for the total Si accumulation in the plants. A close positive correlation was found between TCA-soluble Si and total it in plants grown on pot soils (r=0.669, P<0.01, n=26). The results obtained in the field trials revealed that the available Si extracted by sodium acetate (pH 4.0) could not predict the response of rice to added Si in the calcareous soils satisfactorily. No significant correlation was found between soil available Si content and rice yield, but TCA-soluble Si in the leaf blades of rice was significantly correlated both with rice yield (r=0.57, P<0.01,n=30) and with total plant Si (r=0.89, P<0.01, n=30). It is recommended that, with 95 per cent confidence,the critical value of TCA-soluble Si in the leaves of rice should be 52-57 mg Si kg-1, above which no positive response of rice to added Si would be expected.

Pharmacokinetics of C-1027 in mice as determined by TCA-RA method

AIM: To validate a radioactivity assay, the TCA-RA method, for the measurement of C-1027 in serum and to evaluate its application in determination of pharmacokinetics of C-1027 in mice. METHODS: 125I-C-1027 was prepared by the lodogen method and separated by HPLC. The radioactivity assay was established and used to determine 125I-C-1027 in mice at doses of 10, 50 and 100 μg/kg after precipitation with 20% trichloroacetic acid (TCA-RA method). Several pharmacokinetic parameters were determined after intravenous injection of 125I-C-1027 to mice. RESULTS: After intravenous injection of 125I-C-1027 to mice, at doses of 10, 50 and 100μg/kg; the apparent distribution volumes (Vd) were 0.26, 0.31 and 0.33 L/kg; the biological half-lives (T1/2) were 3.10, 3.40 and 3.90 h; the areas under curve (AUC) were 18.41, 103.69 and 202.74 ng/h/mL; the elimination rate constants (A) were 1.04, 1.26 and 0.58/h; and the total body clearance (Cl) were 0.54, 0.48 and 0.49 L/kg/h, respectively. CONCLUSION: TCA-RA is a sensitive, reliable and suitable method for the determination of 125I-C-1027 in mouse serum.

Effect of Ferric Chloride on the Properties of Biological Sludge in Co-precipitation Phosphorus Removal Process

This paper studied the effect of ferric chloride on waste sludge digestion,dewatering and sedimentation under the optimized doses in co-precipitation phosphorus removal process.The experimental results showed that the concentration of mixed liquid suspended solid(MLSS) was 2436 mg.L-1 and 2385 mg.L-1 in co-precipitation phosphorus removal process(CPR) and biological phosphorous removal process(BPR),respectively.The sludge reduction ratio for each process was 22.6% and 24.6% in aerobic digestion,and 27.6% and 29.9% in anaerobic digestion,respectively.Due to the addition of chemical to the end of aeration tank,the sludge content of CPR was slightly higher than that of BPR,but the sludge reduction rate for both processes had no distinct difference.The sludge volume index(SVI) and sludge specific resistance of BPR were 126 ml.g-1 and 11.7×1012 m.kg-1,respectively,while those of CPR were only 98 ml.g-1 and 7.1×1012 m.kg-1,indicating that CPR chemical could improve sludge settling and dewatering.

Isobaric vapor-liquid equilibrium for methyldichlorosilane-methyltrichlorosilane-dimethyldichlorosilane system

The elucidation of vapor-liquid equilibrium (VLE) of the halogenated silane was necessary for the production of silicon derivatives, especially for methylvinyldichlorosilane, due to the lack of the relevant reports. Isobaric VLE for the system methyldichlorosilane-dimethyldichlorosilane-benzene and isobaric VLE of the three binary systems were measured with a new pump-ebulliometer at the pressure of 101.325 kPa. These binary compositions of the equilibrium vapor were calculated according to the Q function of molar excess Gibbs energy by the indirect method and the resulted VLE data agreed well with the thermo-dynamic consistency. Moreover, the experimental data were correlated with the Wilson, NRTL, Margules and van Laar equations by means of the least-squares fit, the acquired optimal interaction parameters were fitted to experimental vapor-liquid equilibrium data for binary systems. The binary parameters of Wilson equation were also used to calculate the bubble point temperature and the vapor phase composition for the ternary mixtures without any additional adjustment. The predicted vapor-liquid equilibrium for the ternary system was in a good agreement with the experimental results. The VLE of binary and multilateral systems provided essential theory for the production of the halogenated silane.

Modification of methyl oleate for silicon-based biological lubricating base oil

A new kind of silicon-based biological lubricating base oil with good viscosity-temperature behavior,viscosity index,thermostability,oxidation stability and wear resistance performance was synthesized as a derivative of methyl oleate.Trimethylsilylation reaction was introduced to further improve methyl oleate oxidation stability and lubricity after epoxidation and open-ring reactions.The order of effectiveness of acid binding agent was N,N-diisopropylethylamine(DIEA) > pyridine > diethylamine > triethylamine,and the effects of various parameters on the trimethylsilylation reaction as well as on the silicon-oxygen bond stability and reaction yield were studied.A maximum yield of 34.54%was achieved at hydroxyl/trimethyl chlorosilane/DIEA molar ratio of1:1.25:1,reaction temperature 40℃,reaction time 1.5 h.

INHERITANCE OF RESISTANCE TO CYHALOTHRIN IN THE HOUSEFLY(DIPTERA:MUSCIDAE)

The genetic inheritance of resistance to cyhalothrin in housefly, Musca domestica (L) was investigated. Reciprocal crosses between susceptible (S) and resistant (R) strains were used to determine the characteristics of resistance. Analysis of probit line from the F 1 generation and F 2 generation obtained by inbreeding the F 1 hybrids indicated that cyhalothrin resistance was controlled by more than one factors and degree of resistance dominance to cyhalothrin was -0.10, indicating cyhalothrin resistance is conferred by incompletely recessive gene(s). The realized heritability of resistance to cyhalothrin cyhalothrin calculated from data collected routinely from laboratory selection was 0 12.

Using a Two-Liquid-Phase System to Investigate the Biodegradation of Trichlorobenzenes

Due to easy volatilization of volatile organic compounds from water,it is difficult to monitor their aerobic biodegradation in the traditional single water system.Whether a two-liquid-phase system(TLPS) could overcome this obstacle and enhance the degradation of volatile contaminants? In this study,a TLPS composed of silicone oil and water was employed to investigate the biodegradation of volatile compounds,trichlorobenzenes(TCBs),by the adapted microorganisms in an activated soil.The degradation and volatilization of TCBs in TLPS and in a single water system were compared.The results showed that due to volatilization losses of TCBs,the mass balance of TCBs in a single water system was very low.In contrast,using TLPS could effectively inhibit the volatilization losses of TCBs and achieved a very good mass balance during the biodegradation process.Meanwhile,the TLPS could increase microbial activity and microbial growth during the degradation process.With TLPS,the TCB degradation was in descending order of 1,2,4-TCB> 1,2,3-TCB>> 1,3,5-TCB,which was related to the exposed concentration of the contaminants in soil.This study showed that TLPS could be employed as an effective tool to evaluate the biodegradation of volatile hydrophobic organic compounds,which could not be achieved with the traditional single water system.

Effects of P3HT concentration on the performance of organic field effect transistors

Top-contact organic field effect transistors(OFETs) based on poly(3-hexylthiophene)(P3HT) with different concentrations in chloroform(CHCl3) are fabricated.The output characteristics indicate that the P3HT concentration has significant influence on the OFET devices.The performance of the devices firstly is enhanced with increasing the P3HT concentration,and then decreases.The optimized devices with the P3HT concentration of 2 mg/mL show the best performance.The fieldeffect mobility is up to 1.4×10-2 cm2/Vs,the threshold voltage(Vt) is as low as-20 V,and the current on/off ratio(Ion/off) is close to the order of 104.The results suggest that the P3HT aggregation patterns induced by different concentrations can improve the performance of the OFETs.

A quantitative test for heat-induced cell necrosis in vascular cambium and secondary phloem of Eucalyptus obliqua stems

Aims Exposure of Eucalyptus tree stems to the radiant heat of forest fires can kill cambial cells and their embedded regenerative meristems,thus preventing epicormic resprouting and recovery of the tree.Currently,there is no tissue-level method to quantify the viability of cambial cells in Eucalyptus following heat exposure.The first aim of this study was to adapt and validate the tetrazolium reduction method of testing for cell viability in Eucalyptus.The second aim was to apply the method to establish a threshold level of cambium cell viability in Eucalyptus obliqua to enable the identification of a critical temperature.Methods The study used the tetrazolium reduction method to quantitatively determine phloem-cambium cell viability in Eucalyptus.Circular sections of bark with underlying phloem and cambium were cut from mature E.obliqua and samples ranging in mass from 1 to 30 mg were exposed for 1 min to temperature treatments ranging from 20 to 85℃and kept for 20-22 h at room temperature in 0.8%2,3,5-triphenyl tetrazolium chloride(TTC)to test for cell viability.The 1,3,5-triphenyl tetrazolium formazan(TPF)formed was cold extracted with ethanol and quantified as absorbance at 485 nm.Important Findings The TTC reduction method reliably quantified a decline in cell viability with rising temperature in tissue sections that included vascular cambium,and identified 60℃as the critical temperature for cambium-phloem cells of Eucalyptus species.Cell viability,calculated as[TPF Treatment℃]/[TPF 20℃],decli ned by 90%between 20 and 85℃.The cell viability results con firmed that significant tissue necrosis occurred in Eucalyptus at temperatures between 50 and 70℃,after 1 min of in vitro tissue heating.The decline in cell viability with increasing temperature shown by the TTC method was consistent with an independently derived count of live cells following temperature treatment and neutral red staining.

Experimental study on the characteristics of ventilated cavitation around an underwater navigating body influenced by turbulent drag-reducing additives

In this study, a new control strategy for turbulent drag reduction involving ventilated cavitation is proposed. The configurational and hydrodynamic characteristics of ventilated cavities influenced by turbulent drag-reducing additives were experimentally studied in water tunnel. The test model was fixed in the water tunnel by a strut in the aft-part. Aqueous solutions of CTAC/Na Sal(cetyltrimethyl ammonium chloride/sodium salicylate) with weight concentrations of 100, 200, 400 and 600 ppm(part per million), respectively, were injected into the ventilated air cavity from the edge of the cavitator with accurate control by an injection pump. The cavity configurations were recorded by a high-speed CCD camera. The hydrodynamic characteristics of the test model were measured by a six-component balance. Experimental results show that, within the presently tested cases, the lengths of cavity influenced by drag-reducing solution are smaller than normal condition(ventilated cavity) in water, but the asymmetry of the cavity is improved. The drag resisted by the test model is reduced dramatically(the maximum drag reduction can reach to 80%) and the re-entrant jet is more complex after the CTAC solution is injected into the cavity. Turbulent drag-reducing additives have the potential in enhancement of supercavitating asymmetry and further drag reduction.