RAPD Markers Associated with Salt Tolerance in Soybean Genotypes Under Salt Stress

In order to investigate the influence of genetic background on salt tolerance in soybean (Glycine max), ten soybean genotypes (Pusa-20, Pusa-40, Pusa-37, Pusa-16, Pusa-24, Pusa-22, BRAGG, PK-416, PK-1042, and DS-9712) released in India, were selected and grown hydroponically. The 10-day-old seedlings were subjected to 0, 25, 50, 75, 100, 125, and 150 mM NaCl for 15 days. Plant growth, leaf osmotic adjustment, and random amplified polymorphic DNA (RAPD) analysis were studied. In comparison to control plants, the plant growth in all genotypes was decreased by salt stress, respectively. Salt stress decreased leaf osmotic potential in all genotypes; however, the maximum reduction was observed in genotype Pusa-24 followed by PK-416 and Pusa-20, while minimum reduction was shown by genotype Pusa-37, followed by BRAGG and PK-1042. Pusa-16, Pusa-22, Pusa-40, and DS-9712 were able to tolerate NaCl treatment up to the level of 75 Mm. The difference in osmotic adjustment between all the genotypes was correlated with the concentrations of ion examined such as Na⁺ and the leaf proline concentration. These results suggest that the genotypic variation for salt tolerance can be partially accounted by plant physiological measures. Twenty RAPD primers revealed high polymorphism and genetic variation among ten soybean genotypes studied. The closer varieties in the cluster behaved similarly in their response to salinity tolerance. Intra-clustering within the two clusters precisely grouped the ten genotypes in sub-cluster as expected from their physiological findings. Our study shows that RAPD technique is a sensitive, precise, and efficient tool for genomic analysis in soybean genotypes.     

食盐与高血压发病

限盐被许多国家推荐作为一项降压措施,但盐与血压之间存在复杂的相关关系。从原发性高血压的危险因素、食盐与血压的关系,以及盐-血压关系分布模式3个方面综述了食盐在高血压发病中的地位。     

甲基锍盐的合成

在四氟硼酸银存在下，分别以硫醚、硫醇、硫酚或过硫醚为原料与碘甲烷反应制备了相应的甲基锍盐。用１ＨＮＭＲ和１３ＣＮＭＲ表征产物的结构并提出了反应的机理。     

食盐与心血管结局

介绍了食盐与心血管结局关系的最新研究结果,食盐摄入量与心血管结局之间呈J形关系;低盐和高盐都增加心血管危险;不支持普遍减盐推荐。     

SERS in Salt Wells

We report herein a simple, inexpensive fabrication methodology of salt microwells, and define the utility of the latter as nanoparticle containers for highly sensitive surface‐enhanced Raman scattering (SERS) studies. AFM characterization of Ag and Au loaded salt microwells reveal the ability to contain favorable nanostructures such as nanoparticle dimers, which can significantly enhance the Raman intensity of molecules. By performing diffraction‐limited confocal Raman microscopy on salt microwells, we show high sensitivity and fidelity in the detection of dyes, peptides, and proteins, as a proof of our concept. The SERS limit of detection (accumulation time of 1 s) for rhodamine B and TAT contained in salt mircowells is 10 pM and 1 nM , respectively. The Raman characterization measurements of salt microwells with three different laser lines (532 nm, 632.81 nm, 785 nm) reveal low background intensity and high signal‐to‐noise ratio upon nanoparticle loading, which makes them suitable for enhanced Raman detection. SERS mapping of these sub‐femtoliter containers show spatial confinement of the relevant analyte to a few microns, which make them potential candidates for microscale bioreactors.     

熔盐电化学创新研究——武汉大学电化学研究中心熔盐电化学研究工作简介

简要介绍近3年武汉大学电化学研究中心在熔盐电化学方面的若干研究进展:1)熔盐电解固态化合物制备单质硅及其合金以及无机功能材料;2)适于高温熔盐的全密封长寿命Ag/AgCl参比电极和可负载微量粉末的金属腔(坑)工作电极新技术;3)“三相界线电化学”新概念以及描述三相界线在薄层固态化合物电解还原过程中扩展变化的薄层模型.     

Salt doping in electronprobe microanalysis

A new method of electronprobe microanalysis (EPMA) is suggested. It is based on creating ionic conductivity in frozen water solutions and in polymer films by doping them with a salt. This procedure is effective to prevent surface charging and allows imaging of nonconducting samples by scanning electron microscopy (SEM) as well as X-ray microanalysis. Specifically, this procedure makes it possible to perform EPMA of samples with xerogel matrices, which were used for molecular laser microprobe mass spectrometry analysis, and consequently to provide complex microprobe examination of samples. Received: 24 January 1996 / Revised: 4 July 1996 / Accepted: 16 July 1996     

季铵盐、季膦盐类高分子抗菌剂的研究进展

综述了季铵盐、季膦盐类高分子抗菌剂的研究进展,包括该类抗菌剂的合成、性能及抗菌机理。现有的研究结果表明,含有多种杀菌基团高分子抗菌剂的抗菌作用可能与杀菌基团的种类、杀菌基团的固载量、载体与杀菌基的结合位置、杀菌基团的分布、载体的表面亲水性能、聚合物的交联度、链结构等有关。若能在分子结构中同时有序引入季铵盐或季膦盐、海因类杀菌基团,有可能存在杀菌基团的协同效应,并且可能形成一个新的高分子抗菌材料的研究分支。     

Salt effect on polymer solutions

The salt effect was investigated by measurements of viscosity, cloud point, and solubility of aqueous solutions of poly(vinyl alcohol—acetate) copolymers, as these copolymers in water are sensitive in various ways to addition of various electrolytes. The major role in the salt effect is played by the anions, and water-structure breaking anions produce salting-in of the copolymers. Tetraalkylammonium halides (bromides and iodides) cause salting-in of the copolymers more effectively with increase of size of the hydrophobic cations. The Setschenow equation does not hold for the polymers except for very dilute polymer concentration. In salts of monoalkyl-substituted anions (R? COONa and R? SO₄Na) and cations (R? NH₃Cl and Br), so long as the alkyl chain is short, the salt effect is also dominated by the anions. With increase of the alkyl chain length, sodium salts of the monoalkyl-substituted anions exert a stronger salting-in effect upon the polymers than chlorides of similar long-chain cations. The significance of the counteranions is suggested for the interaction of nonionic polymers and the long-chain cations. The action of the salts on the copolymers is discussed in terms of medium effects (change of the water structure) and of the binding effect of the single ions to the polymers.     

一个课外化学探究实验的设计——食用加碘盐的简易识别方法

设计了一种能够在家庭条件下实现的检查食盐是否含碘的简易识别方法——KI-淀粉试纸法。食盐中的碘以碘酸钾形式存在, 利用碘酸根的氧化性及碘离子的还原性, 2者在酸性条件下生成碘单质, 遇淀粉变蓝来鉴定。此KI-淀粉试纸法也可以帮助消费者在家庭条件下对食盐中是否含碘进行检验, 为市民吃上合格的加碘食盐提供了一种简易识别方法。     

盐桥的作用是什么

本文从盐桥对液体接界电势的影响、盐桥降低接界电势的原因及选用盐桥的方法几方面对盐桥的作用给予了探讨与介绍。     

Imidazolium Salt Ion Pairs in Solution

The formation, stabilisation and reactivity of contact ion pairs of non‐protic imidazolium ionic liquids (ILs) in solution are conceptualized in light of selected experimental evidence as well theoretical calculations reported mainly in the last ten years. Electric conductivity, NMR, ESI‐MS and IR data as well as theoretical calculations support not only the formation of contact ion pairs in solution, but also the presence of larger ionic and neutral aggregates even when dissolved in solvents with relatively high dielectric constants, such as acetonitrile and DMSO. The presence of larger imidazolium supramolecular aggregates is favoured at higher salt concentrations in solvents of low dielectric constant for ILs that contain shorter N‐alkyl side chains associated with anions of low coordination ability. The stability and reactivity of neutral contact species are also dependent on the nature of the anion, imidazolium substituents, and are more abundant in ILs containing strong coordinating anions, in particular those that can form charge transfer complexes with the imidazolium cation. Finally, some ILs display reactivities as contact ion pairs rather than solvent‐separated ions.     

Salt softening of polyelectrolyte multilayer microcapsules

By using a combination of atomic force and confocal microscopy, we explore the effect of 1:1 electrolyte (NaCl) on the stiffness of polyelectrolyte microcapsules. We study the "hollow" and "filled" (with polystyrene sulfonate) capsules. In both cases the shells are composed of layers of alternating polystyrene sulfonate (PSS) and polyallylamine hydrochloride (PAH). The stiffness of both "hollow" and "filled" capsules was found to be largest in water. It decreases with salt concentration up to approximately 3 mol/L and gets quasi-constant in more concentrated solutions. The "filled" capsules are always stiffer than "hollow." The observed softening correlates with the salt-induced changes in morphology of the multilayer shells detected with the scanning electron microscopy. It is likely that at concentrations below approximately 3 mol/L the multilayer shell is in a "tethered" state, so that the increase in salt concentration leads to a decrease in number of ionic cross-links and, as a result, in the stiffness. In contrast, above the critical concentration of approximately 3 mol/L multilayer shells might be in a new, "melted," state. Here the multilayer structure is still retained, but sufficient amount of ionic cross-links is broken, so that further increase in salt concentration does not change the capsule mechanics. These ideas are consistent with a moderate swelling of multilayers at concentrations below approximately 3 mol/L and significant decrease in their thickness in more concentrated solutions measured with surface plasmon spectroscopy.     

Salt effects on the Baylis-Hillman reaction

The Baylis-Hillman reaction is shown to accelerate in salt solutions of water and the ‘water-like’ structured solvents, like formamide and N-methylformamide in the presence of DABCO. Ethylene glycol, another structured solvent and its salt solutions fail to make any impact on the reaction rates. The salts that are conventionally defined as salting-out or -in do not behave in a similar fashion, when employed in the Baylis-Hillman reactions. The results are supported by solubility measurements. It seems that the cation, anion, nature of solvent and of reactants together ascertain whether a salt will enhance or retard the Baylis-Hillman reaction.     

Spectroscopic Characterization of Carbazole-TCAQ Charge-Transfer Salt

Spectroscopic characterizations of carbazole-TCAQ salt were investigated by means of UV-visible and fluorescence spectra. The results show that carbazole and TCAQ can form a kind of charge-transfer salt whose characteristic adsorption is π→π^* of 248 nm when the mixture of the two compounds is irradiated by UV-light, and the charge-transfer salt becomes more stable with the increase of irradiation time.     

Salt softening of polyelectrolyte multilayer capsules

The changes in the morphology and the mechanical properties of hollow polyelectrolyte multilayer capsules made from poly(styrenesulfonate)/poly(allylamine hydrochloride) in response to added salt were investigated. We found that capsules shrink in response to salt exposure. The effect depends strongly on the nature of the salt added and follows trends of the Hoffmeister series, with weakly hydrated cations inducing the strongest shrinking. For NaCl, we have investigated additional effects on capsule mechanical properties that are occurring above a 3 M salt concentration and we found that the morphological changes are accompanied by a pronounced softening of the capsule wall material, which we can quantify by analyzing the force response of capsules in the prebuckling regime. This shows that salts can act as plasticizers in the multilayers and induce annealing effects.     

依托度酸哌嗪盐的制备及其性能表征

制备了依托度酸和哌嗪的有机盐,并得到了其晶体结构。 结构解析结果表明,依托度酸羧基上的氢转移到哌嗪的氮原子上,N—H••••O氢键是维持结构稳定的主要分子间相互作用。 与原药相比,新合成的盐的本征溶出速率和平衡溶解度分别提高了2.1倍和4.8倍。 此外,新合成的盐具有良好的水合稳定性,在25 ℃,相对湿度95%的条件下暴露28 d未发生相变。作为依托度酸的第一个有机盐,该盐是依托度酸有前景的固体存在形式。