水稻秸秆快速腐解工艺研究

为提高水稻秸秆的腐解速率,将秸秆粉碎后采用氨碱剂与复合菌剂结合进行处理。通过考查氨碱剂、复合菌剂的用量对秸秆颜色、渗出液pH值、疏松程度等的影响,得出秸秆快速腐解工艺条件为:m(秸秆)∶m(氧化钙)∶m(尿素)=200∶9∶4,氨碱处理4天,m(侧孢芽孢杆菌)∶m(地衣芽孢杆菌)∶m(枯草芽孢杆菌)∶m(发酵菌)=5∶4∶4∶10,m(秸秆):m(复合菌剂)>125∶1,复合菌剂处理12天。考查了秸秆不同腐解阶段的化学结构与微观结构,结果表明:腐解后秸秆中的碳水化合物发生分解,结构变得疏松多孔,而且随着秸秆腐解,碳水化合物、酰胺类化合物和糖类逐渐减少,羧基增多。

Yield and Nicotine Content of Flue-Cured Tobacco as Affected by Soil Nitrogen Mineralization

Nitrogen(N)supply is the most important factor affecting yield and quality of flue-cured tobacco(FCT).A field experiment and an in situ incubation method were used to study the effects of soil N mineralization in the later stages of growth on yield and nicotine content of FCT in Fenggang and Jinsha,Guizhou Province.The yield and market value of FCT at Fenggang were much lower than those at Jinsha.However,the nicotine content of middle and upper leaves was much higher at Fenggang than at Jinsha when the same rate of fertilizer N was applied,which might be due to a higher N supply capacity at the Fenggang site.At later stages of growth(7-16 weeks after transplanting),the soil net N mineralization at Fenggang(56 kg N ha^(-1))was almost double that at Jinsha(30 kg N ha^(-1)).While soil NH_4-N and NO_3-N were almost exhausted by the plants or leached 5 weeks after transplanting,the N taken up at the later growth stages at Fenggang were mainly derived from soil N mineralization,which contributed to a high nicotine content in the upper leaves.The order of soil N contribution to N buildup in different leaves was:upper leaves>middle leaves>lower leaves.Thus,soil N mineralization at late growth stages was an important factor affecting N accumulation and therefore the nicotine content in the upper leaves.

ANTI-HYPOXIA AND ANTI-OXIDATION EFFECTS OF AMINOPHYLLINE ON HUMAN WITH ACUTE HIGH-ALTITUDE EXPOSURE

Objective To investigate the anti-hypoxia and anti-oxidation effects of aminophylline on human with acute high- altitude exposure. Mothoda Totally 100 young male army members newly recruited from Sichuan province （400 meters above sea level） were enrolled. They were randomly divided into two groups： 50 in aminophylline group （A group） and 50 in control group （ C group）. A group and C group orally took aminophylline and placebo respectively for 10 days, 7 days before entering Lhasa （3 658 meters above sea level） by air and 3 days after it. Several parameters were measured at three time points： before drug taken, 7 days after drug taken, and 3 days after ascending high altitude. These parameters included serum levels of nitric oxide （NO）, superoxide dismutase （SOD）, catalase （CAT）, hydrogen dioxide （H2O2）, lactic acid （LA）, as well as arterial oxygen saturation （SO2）, arterial oxygen partial pressure （PaO2）, and arterial carbon dioxide partial pressure （PaCO2）. Statistical analysis was conducted to compare the difference between two groups with Stata 7.0 software system. Results There were no statistical differences between groups in hypoxia and oxidation indicators before and after drug taken in plain area. Three days after ascending high altitude, the serum levels of SOD, CAT, H202, LA, PaCO2 increased in both groups, yet to a much larger degree in C group than A group （P 〈0. 01 ） ; and NO, SO2 , PaO2 decreased more markedly in C group （ P 〈 0. 05 for NO, P 〈 0. 0001 for SO2 and PaO2 ）. Conclusion Aminophylline has significant anti-hypoxia and anti-oxidation effects at high altitude.

Simultaneous Synthesis of Dimethyl Carbonate and Poly（ethylene terephthalate） Using Alkali Metals as Catalysts

Dimethyl carbonate （DMC） and poly（ethylene terephthalate） was simultaneously synthesized by the transesterification of ethylene carbonate （EC） with dimethyl terephthalate （DMT） in this paper. This reaction is an excellent green chemical process without poisonous substance. Various alkali metals were used as the catalysts. The results showed alkali metals had catalytic activity in a certain extent. The effect of reaction condition was also studied. When the reaction was carded out under the following conditions： the reaction temperature 250℃, molar ratio of EC to DMT 3 ： 1, reaction time 3h, and catalyst amount 0.004 （molar ratio to DMT）, the yield of DMC was 68.9%.

Effects of Matrine on Aconitine-Induced Electrophysiological Changes in Rat Ventricular Myocytes

Aim To explore the reason that the antiarrhythmic effect of the extract oftraditional Chinese medicinal herb, matrine, is weaker than quinidine and verapamil by comparison ofthe effect and efficacy of matrine on various kinds of transmembrane ionic currents with those ofquinidine and verapamil; and to demonstrate the best targets for antiarrhythmic drugs. MethodsWhole-cell patch-clamp techniques were used to record the action potential and ionic currents insingle cells of rat ventricular myocytes. Aconitine was used to induce the changes of ioniccurrents, then study the effects of matrine and quinidine, verapamil on aconitine-induced unbalancedchannel currents and action potential. Results Aconitine 1 μmol·L^(-1) induced significantchanges in transmembrane currents and action potential in single cells of rat ventricular myocytes.APD was significantly prolonged by aconitine. Simultaneously, aconitine increased sodium, L-typecalcium and inward rectifier potassium currents. Matrine 100 μmol· L^(-1) reversed theaconitine-induced changes of sodium current (I_(Na)) from (-70.2+- 10.5) pA/pF to ( - 39.6+-4.0)pA/pF(n = 5, P < 0.05 vs aconitine); L-type calcium current (I_(Ca-L)) from (20.4+- 3.8) pA/pF to (- 12.9+- 2.9) pA/pF ( n = 6, P < 0.01); the inward rectifier potassium current (I_(k1) ) from (-32.2+- 1.08) pA/pF to ( -24.0+-3.4) pA/pF (n = 6, P < 0.01), and action potential duration. Thereversal effects of quinidine and verapamil on aconitine-induced changes of APD and ionic currentswere more marked than matrine. Conclusion Aco-nitine significantly disturbs the normal equilibriumof ion channels in ventricular myocytes. It induces changes of I_(Na), I_(Ca-L), I_(K1) andprolongation of action potential duration. Matrine at concentration 50 or 100 μmol·L^(-1)statistically significantly suppresses aconitine-induced changes of APD and ionic currents. Thepotency and efficacy of inhibitory effect of matrine are markedly weaker than those of commonly usedverapamil and quinidine.

Titratable Acidity and Alkalinity of Red Soil Surfaces

The surfaces of red soils have an apparent amphotenc character, carrying titratable acidity and titratable alkalinity simultaneously. The titratable acidity arises from deprotonation of hydroxyl groups of hydrous oxide-type surfaces and dissociation of weak-acid functional groups of soil organic matter, while the titratable alkalinity is derived from release of hydroxyl groups of hydrous oxide-type surfaces. The titratable acidity and titratable alkalinity mainly depended on the composition and content of iron and aluminum oxides in the soils. The results showed that the titratable acidity and titratable alkalinity were in significantly positive correlation not only with the content of amorphous aluminum oxide(Alo) and iron oxide(Feo) extracted with acid ammonium oxalate solution, free iron ox-ide(Fed) extracted with sodium dithionite-citrate-bicarbonate (DCB) and clays, but also with the zero point of charge (ZPC) of the samples. Organic matter made an important contribution to the titratable acidity. The titratable alkalinity was closely correlated with the amount of fluoride ions adsorbed. The titratable acidity and titratable alkalinity of red soils were influenced by parent materials, being in the order of red soil derived from basalt > that from tuff > that from granite. The titratable acidity and titratable alkalinity were closely related with origination of the variable charges of red soils, and to a certain extent were responsible for variable negative and positive charges of the soils.

Organocatalytic asymmetric allylic alkylation of sulfonylimidates with Morita-Baylis-Hillman carbonates

The asymmetric allylic alkylation reaction of sulfonylimidates with various Morita-Baylis-Hillman (MBH) carbonates was accomplished by the catalysis of commercially available cinchona alkaloids catalyst (DHQD)2AQN.The corresponding allylic alkylation products were obtained in good yields with high stereoselectivities (up to 99% ee,89:11 dr).

Combined Use of Alkaline Slag and Rapeseed Cake to Ameliorate Soil Acidity in an Acid Tea Garden Soil

Rapeseed cake （RC）, the residue of rapeseed oil extraction, is effective for improving tea （Camellia sinensis） quality, especially taste and aroma, but it has limited ability to ameliorate strongly acidic soil. In order to improve the liming potential of RC, alkaline slag （AS）, the by-product of recovery of sodium carbonate, was incorporated. Combined effects of different levels of RC and AS on ameliorating acidic soil from a tea garden were investigated. Laboratory incubations showed that combined use of AS and RC was an effective method to reduce soil exchangeable acidity and A1 saturation and increase base saturation, but not necessarily for soil pH adjustment. The release of alkalinity from the combined amendments and the mineralization of organic nitrogen increased soil pH initially, but then soil pH decreased due to nitrifications. Various degrees of nitrification were correlated with the interaction of different Ca levels, pH and N contents. When RC was applied at low levels, high Ca levels from AS repressed soil nitrification, resulting in smaller pH fluctuations. In contrast, high AS stimulated soil nitrification, when RC was applied at high levels, and resulted in a large pH decrease. Based on the optimum pH for tea production and quality, high ratios of AS to RC were indicated for soil acidity amelioration, and 8.0 g kg-1 and less than 2.5 g kg-1 were indicated for AS and RC, respectively. Further, field studies are needed to investigate the variables of combined amendments.

Antiviral activities against influenza virus(FM1) of bioactive fractions and representative compounds extracted from Banlangen(Radix Isatidis)

OBJECTIVE: To study the antiviral activities of clemastanin B(CB), epigoitrin, phenylpropanoids portion(PEP) and the mixture of phenylpropanoids, alkaloids and organic acid fractions(PEP+ALK+OA)from Banlangen(Radix Isatidis).METHODS: The experiment consisted of four parts:therapeutic action, prophylaxsis action, inhibition of virus attachment, and direct virucidal action. Cytopathic effect(CPE) and 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium(MTT) were used to assess antiviral activity.RESULTS: CB, epigoitrin, PEP and PEP + ALK + OA fractions from Banlangen(Radix Isatidis) extract significantly increased the viability of MDCK cells pre-infected with the virus compared with the virus control group in all the dilutions(P < 0.01). Pretreated with either pure compounds or chemical frac-tions of Banlangen(Radix Isatidis) extract in all the dilutions significantly improved the viability of MDCK cells(P < 0.01). The inhibition of virus absorption to the host cells by CB, epigoitrin and PEP was in a dose dependent manner.CONCLUSION: CB, epigoitrin, PEP and PEP+ALK+OA exert their anti-influenza activity by inhibiting the virus multiplication, prophylaxsis and blocking the virus attachment. The primary mode of action of PEP and PEP + ALK + OA is the inhibition of virus replication. The inhibitory effects on virus attachment and multiplication are the main modes for epigoitrin.

Muscarinic acetylcholine receptor modulators derived from natural toxins and diverse interaction modes

Muscarinic acetylcholine receptors （mAChRs） play crucial roles in various physiological functions and pathophysiological processes. Acetylcholine （ACh）, as a classical ligand and one of the pivotal neurotransmitters, serves as a prototype for the elucidation of molecular interaction and the development of mimicked and antagonized agents. With the advances in medicinal chemistry and structural biology, more and more mAChRs modulators derived from natural toxins have been identified. Based on the chemical structures and the receptor-ligand interaction modes, these mAChRs modulators can be divided into orthosteric modulators, allosteric modulators and other modulators. Moreover, allosteric modulators can be further divided into three groups： alcuronium-like modulators, staurosporine-like modulators, and phlegrnarine-like modulators. In this review, we focus on various mAChRs modulators derived from natural toxins on the basis of the receptor-ligand interaction modes. The under- standing of the affinity, the intrinsic efficacy, and the selectivity of mAChRs modulators may lead to the discovery of new drug leads for the treatment of diseases related to mAChRs.