核桃叶腐解液对小麦幼苗生理指标的影响

为揭示核桃叶腐解液对小麦的化感效应,选用4个小麦品种（系）的种子为受体,研究了不同浓度核桃叶腐解液对小麦种子萌发率、幼苗淀粉酶活力、脯氨酸含量、α‐NA含量和MDA含量的影响。结果表明：核桃叶腐解液可显著降低4个小麦品种（系）种子的萌发率、淀粉酶活性和a‐NA含量,显著提高Pro含量和MDA含量,且这些变化均具有明显的浓度依赖性。结果还表明4个小麦品种（系）对核桃叶腐解液表现出不同程度的耐受性。     

不同腐解方式下棉秆腐解液对棉花枯、黄萎病菌的化感效应

采用自然腐解与接种微生物人工腐解两种方式分别处理棉秆,研究了两种腐解物水浸提液对棉花枯、黄萎病菌的化感效应。结果显示,两种腐解液对枯、黄萎病菌的菌丝生长及孢子萌发均具有较强的抑制作用,抑制强度整体上随着腐解液浓度的升高而增大。棉秆自然腐解液对枯、黄萎病菌菌丝生长的最大抑制率分别为58.17%、48.16%,对孢子萌发的最大抑制率分别为23.29%、16.22%,对枯、黄萎病菌毒力的有效中浓度（EC50）分别为33.20、45.20g·L-1;人工腐解液对枯、黄萎病菌菌丝生长的最高抑制率分别为71.63%、79.04%,对孢子萌发的最高抑制率分别为35.45%、42.74%,EC50分别为24.18、20.75g·L-1。表明棉秆腐解后具有作为植物源抑菌剂的开发潜力,并且采用人工方式腐解棉秆能有效提高腐解液对棉花枯、黄萎病菌的抑制强度。     

漂浮育苗方式下烟草根茬腐解液对幼苗生长的化感效应

[目的]揭示烟草连作障碍的作用机制,为消除农业生产上烟草的连作障碍提供理论依据。[方法]以漂浮育苗的方式,研究了不同浓度烟草根茬腐解液对幼苗生长的影响。[结果]当烟草根茬腐解液浓度为0.1 g/ml时,能促进幼苗的生长,能显著提高烟株的干物质重量,增强硝酸还原酶活性和根系活力。随着腐解液浓度的提高,促进作用逐渐转为抑制作用。当烟草根茬腐解液浓度达0.2 g/ml时,烟株硝酸还原酶活性明显下降,过氧化物酶活性和丙二醛含量显著上升。当烟草根茬腐解液浓度达0.3 g/ml以上时,烟株硝酸还原酶活性最低,过氧化物酶活性和丙二醛含量达最大。[结论]烟草根茬腐解液对烟苗的生长产生了不同程度的化感效应,随腐解液浓度的提高表现出明显的＂低促高抑＂的现象。     

复方党参口服液对小鼠免疫功能的影响

为探讨复方党参口服液对小鼠免疫功能的影响,将40只健康昆明系小鼠随机分成对照组、低剂量组、中剂量组和高剂量组,每组10只,分别灌服生理盐水,口服液浓度为0.5,1.0,1.5 g/ml,各0.1 ml/只.d。试验10 d后,测定小鼠脾脏系数、胸腺系数和体增重(试验第11 d时与0 d时小鼠体重的差值),并进行脾脏的组织形态学观察;测定各组小鼠腹腔巨噬细胞的吞噬功能以及红细胞免疫功能。结果表明,复方党参口服液可显著增加小鼠脾脏系数,升高小鼠腹腔巨噬细胞吞噬百分率和吞噬指数。初步证明复方党参口服液对正常小鼠的免疫功能有较强的促进和调节作用。     

Evaluation of Aqueous Biphasic Electrophoresis System Based on Halide-Free Ionic Liquids for Direct Recovery of Keratinase

Aqueous biphasic electrophoresis system (ABES) incorporates electric fields into the biphasic system to separate the target biomolecules from crude feedstock. Ionic liquid (IL) is regarded as an excellent candidate as the phase-forming components for ABES because of the great electrical conductivity, which can promote the electromigration of biomolecules in ABES, and thereby enhances the separation efficiency of the target biomolecules from crude feedstock. The application of electric fields to the conventional biphasic system expedites the phase settling time of the biphasic system, which eases the subsequent scaling-up steps and reduces the overall processing time of the recovery process. Alkyl sulphate-based IL is a green and economical halide-free surfactant when compared to the other halide-containing IL. The feasibility of halide-free IL-based ABES to recover Kytococcus sedentarius TWHK01 keratinase was studied. Optimum partition coefficient (K_e = 7.53 ± 0.35) and yield (Y_T = 80.36% ± 0.71) were recorded with IL-ABES comprised of 15.0% (w/w) [EMIM][ESO₄], 20.0% (w/w) sodium carbonate and 15% (w/w) crude feedstock. Selectivity (S) of 5.75 ± 0.27 was obtained with the IL-ABES operated at operation time of 5 min with 10 V voltage supplied. Halide-free IL is proven to be a potential phase-forming component of IL-ABES for large-scale recovery of keratinase.     

土壤性质对1-丁基-3-甲基咪唑类离子液体吸附/脱附行为的影响

研究了2种咪唑类离子液体(ILs)——氯化1-丁基-3-甲基咪唑([Bmim][Cl])和1-丁基-3-甲基咪唑双三氟甲磺酰亚胺盐([Bmim][(CF_3SO_2)_2])在16种土壤上的吸附/脱附规律,探讨了土壤理化性质对于吸附/脱附行为的影响。研究发现,[Bmim][Cl]和[Bmim][(CF_3SO_2)_2N]的土壤吸附系数与土壤阳离子交换量(CEC)呈正相关性,相关系数(R~2)分别为0.842 9和0.835 3(P0.05),表明土壤主要通过静电作用来吸附ILs,而与土壤总有机碳含量(TOC%)的R~2值仅分别为0.003 5和0.073 0(P0.01),说明ILs与土壤有机质的疏水结合作用为相对次要。ILs阴离子基团对吸附行为有一定的影响,但并不明显。ILs吸附/脱附的迟滞系数(HI)均小于1,可能与(ILs)在土壤粘土/有机质上的不可逆结合有关。其中,CEC和[Bmim][Cl]和[Bmim][(CF_3SO_2)_2]的HI之间存在较大的相关性(R~2分别为0.772 9,0.781 5,P0.01),说明CEC对迟滞行为有着不可忽视的影响。     

Alternative and Efficient Extraction Methods for Marine-Derived Compounds

Marine ecosystems cover more than 70% of the globe’s surface. These habitats are occupied by a great diversity of marine organisms that produce highly structural diverse metabolites as a defense mechanism. In the last decades, these metabolites have been extracted and isolated in order to test them in different bioassays and assess their potential to fight human diseases. Since traditional extraction techniques are both solvent- and time-consuming, this review emphasizes alternative extraction techniques, such as supercritical fluid extraction, pressurized solvent extraction, microwave-assisted extraction, ultrasound-assisted extraction, pulsed electric field-assisted extraction, enzyme-assisted extraction, and extraction with switchable solvents and ionic liquids, applied in the search for marine compounds. Only studies published in the 21st century are considered.     

Predicting mobility of alkylimidazolium ionic liquids in soils

Background, aim, and scope  Ionic liquids (ILs) are a new class of alternative solvents that make ideal non-volatile media for a variety of industrial processes such as organic synthesis and biocatalysis, as alternative electrolytes, as phases and phase modifications in separation techniques, and as alternative lubricants. Once the large-scale implementation of ILs begins, the industrial application will follow. In view of their great stability, they could slip through classical treatment systems to become persistent components of the environment, where the long-term consequences of their presence are still unknown. Sorption on soils has a critical effect on the transport, reactivity, and bioavailability of organic compounds in the environment. So far, the IL sorption mechanism was investigated solely on the basis of batch experiments, which precluded any assessment of the dynamics of the process. An understanding of the mobility of ILs in soil columns is crucial for an accurate prediction of their fate in the soil. The aim of this study therefore was to investigate in detail the mobility of selected imidazolium ILs on three soil types. Moreover, it was decided to study these processes in soils from the coastal region (Gdańsk, Poland), which usually constitute a very important geochemical compartment, participating in the transport of contaminants on their way to the sea. Materials and methods  The mobility of alkylimidazolium ILs was investigated in columns containing soils from the coastal area. In addition, the sorption processes in all the soil systems studied were described isothermally and the equilibrium sorption coefficient was evaluated. The sorption capacities were determined according to OECD guidelines. Sorption dynamics was studied with use of polypropylene columns (diameter—10 mm, height—100 mm) packed with 10 g of soil. The ionic liquid solution was then injected into the soil column and left for 24 h to equilibrate. After this, a solution of 0.01 mM CaCl₂ was pumped through the column at a rate of 0.3 ml min^–1. Effluents were collected from the bottom of the column and analyzed by HPLC. Results  Sorption was strongest on the Miocene silt and the alluvial agricultural soil and weakest on the podsolic soil and Warthanian glacial till. The K _d value of long-chain ILs was far higher than that of the short-chain ones. Among the substances tested, hydroxylated ILs were usually more weakly sorbed. Desorption of ILs is inversely correlated with sorption intensity. The experimental results of the column tests correlate well with those from batch experiments. In the cases of weakly binding soils, ILs were detected almost immediately in the eluent. The elution profiles of long-chain ILs indicate that these compounds are very strongly sorbed onto most soils, although certain amounts were transported through the soil. ILs exhibit a certain mobility in soils: in particular, salts with short and/or hydroxylated side chains are extremely mobile. Discussion  The results indicate a stronger binding of ILs in the first sorption layer; once the first layer is saturated, there are no more active sites on the soil surface (no free charged groups); hence, there are no more strong electrostatic binding sites, and dispersive interaction becomes the dominant interaction potential. The influence of the structure of the ILs, especially the side-chain length was also confirmed: The K _d value of long-chain ILs was far higher than that of the short-chain ones. The long alkyl side chain facilitates dispersive interactions with soil organic matter and intermolecular binding, and the build-up of a second layer becomes possible. Among the substances tested, hydroxylated ILs were usually more weakly sorbed. The hydroxyl group in the side chain can alter the polarity of the compound so strongly that interaction with organic matter hardly occurs; these salts then remain in the aqueous phase. The experimental results from the column tests correlate well with those from batch tests. In the weakly binding soils (with low organic matter), the only binding to the soil surface must be via electrostatic interactions, although intermolecular van der Waals (ionic liquid–ionic liquid) interactions could also be taking place. The elution profile maxima for organic rich soils are far smaller than for the other soils. In the former, hydrogen bonding, dispersive and π…π interactions play a more important part than electrostatic interactions. The rapidly “disappearing” maxima of the elution peaks may indicate that, after elution of ILs from the second layer, it is difficult to extract further sorbed ILs. In the first layer, the ILs are bound by much stronger electrostatic interactions. To break these bonds, a greater energy is required than that sufficient to extract ILs from double sorption layers. Results indicate, moreover, that hydrophobic ILs will be sorbed in the first few centimeters of the soil; migration into the soil will therefore be almost negligible. Conclusions  Sorption of ILs was the strongest in soils with the highest cation exchange capacities and a high organic content. ILs were also more strongly bound to the first sorption layer. The sorption coefficients of long-chain ILs were far higher than those of short-chain ones; usually, hydroxylated derivatives were the least strongly sorbed. Results of soil column experiments to investigate the mobility of ILs in soils correlated well with those from batch tests, and the elution profiles were also well correlated with organic matter content. The observed rapidly disappearing elution peak maxima probably indicate that, after elution of the ILs from the second layer, it is difficult to extract further sorbed compounds. Recommendations and perspectives  Obtained results gave an interesting insight into mobility of ionic liquids in soil columns. However, several questions are now opened. It is therefore necessary to undertake further studies focused on total cycle of ionic liquids in the soil environment. This should include their evapotrasporation (lysimeter test), bioaccumulation by plants as well as degradation and transformation processes (chemical, biological, and physical) typically occurring in soils. Moreover, a further risk assessment of ILs is desirable since this study has indicated that these compounds, especially those with low lipophilicities, are generally mobile in the soil matrix. It is already known that short-chain ILs are characterized by low toxicities; should they enter the environment, they will probably migrate within the soil and pose a risk of contamination of surface and ground waters. This topic is relevant to the audience. Environmental threat of short-chain ionic liquids is currently unknown. From the predictive point of view, judging on known low acute toxic effects or high polarities of these compounds seems to be not enough to confirm their “environmental friendliness”. If we are to fully understand the potential environmental effects, one should also have an insight into long-term biological consequences of these ionic liquids, including chronic toxicity tests, bioaccumulation, and biotransformation rates as well as stability against natural elimination mechanisms.     

施肥种类对青海草地早熟禾草地土壤呼吸的影响

为了解草地生态系统对全球碳素变化的贡献,通过便携CO₂/H₂O红外气体分析仪EGM-4研究腐熟羊粪、磷酸二铵和生羊粪处理下青海草地早熟禾（Po apratensis‘Qinghai’）草地的土壤呼吸速率,并测定草地土壤温度、含水量和有机质含量。结果表明：肥料种类对土壤呼吸的影响差异显著。与各处理对照呼吸速率相比（1.27,0.99和0.42g CO₂·m^-2·h^-1）,适量腐熟羊粪表现为促进土壤呼吸（1.72,1.53和0.69g CO₂·m^-2·h^-1）,而化肥在盛花期时抑制土壤呼吸（0.99g CO₂·m^-2·h^-1）,成熟期时对土壤呼吸无影响（1.16g CO₂·m^-2·h^-1）,枯黄期则促进土壤呼吸（0.72g CO₂·m^-2·h^-1）。土壤呼吸与土壤温度、有机质含量呈指数正相关,与0~10cm土壤含水量呈线性关系。腐熟羊粪处理提高了Q₁₀,而磷酸二铵和生羊粪对Q₁₀无影响;磷酸二铵和腐熟羊粪处理的土壤呼吸与土壤含水量相关系数比生羊粪的高。有机肥降低了土壤呼吸与土壤有机质的相关系数,而磷酸二铵对其无影响。腐熟羊粪可以提高土壤对土温的敏感性而降低土壤呼吸对土壤有机质含量的敏感性。     

Larvicidal and residual activity of imidazolium salts against Aedes aegypti (Diptera: Culicidae)

BACKGROUND

Aedes aegypti is an important mosquito species that can transmit several arboviruses such as dengue fever, yellow fever, chikungunya and zika. Because these mosquitoes are becoming resistant to most chemical insecticides used around the world, studies with new larvicides should be prioritized. Based on the known biological profile of imidazolium salts (IS), the objective of this study was to evaluate the potential of six IS as larvicides against Ae. aegypti, as tested against Ae. aegypti larvae. Larval mortality was measured after 24 and 48 h, and residual larvicidal activity was also evaluated.

RESULTS

Promising results were obtained with aqueous solutions of two IS: 1‐n‐octadecyl‐3‐methylimidazolium chloride ( C ₁₈ MImCl ) and 1‐n‐hexadecyl‐3‐methylimidazolium methanesulfonate ( C ₁₆ MImMeS ), showing up to 90% larval mortality after 48 h exposure. C ₁₈ MImCl was more effective than C ₁₆ mIMeS , causing mortality until day 15 after exposure. An application of C ₁₈ MImCl left to dry under ambient conditions for at least 2 months and then dissolved in water showed a more pronounced residual effect (36 days with 95% mortality and 80% mortality up to 78 days).

CONCLUSION

This is the first study to show the potential of IS in the control of Ae. aegypti. Further studies are needed to understand the mode of action of these compounds in the biological development of this mosquito species. © 2017 Society of Chemical Industry