Pentafluorobenzaldehyde and its utilizing in organic synthesis

Over the past 50 years, pentafluorobenzaldehyde has received much attention due to its unique chemical and physical properties as well as its real or potential applications in chemistry of porphyrines, additives, drug delivery and in analytical chemistry. Pentafluorobenzaldehyde is multifunctional aromatic compound containing five atoms of fluorine and one aldehydic function. That is why it can provide nucleophilic substitutions of all or some atoms of fluorine, nucleophilic additions of aldehydic function, “haloform reaction” and some cyclization reactions. This year, it is being the 50th year, since the first synthesis of this compound was published.     

GC-MS技术在舰船复合板毒性评价中的应用

海军舰船舱室多为密闭环境,其舱室狭小,设备庞杂,人员密集。舱室内部的防护装饰多系非金属材料,随着现代各种复合、聚合材料的迅速发展和广泛使用,周围环境特别是密闭舱室空气污染的问题也更为突出。本文根据有关军用标准和规程[1],应用GC-MS技术对2种舰船复合板常温释放物和高     

Synthesis and properties of new functionalized guanidinium based ionic liquids as non-toxic versatile organic materials

Functionalized guanidinium ionic liquids as a new class of versatile organic materials have been developed. Guanidinium salts containing olefinic functionalities have been prepared and completely characterized. In order to illustrate the versatility of olefinic units, they were brominated and some bromine-containing ionic liquids have been obtained. Relevant physico-chemical properties of the new synthesized salts were evaluated including their melting points, glass transition temperatures, miscibilities, densities, surface tensions and contact angles with glass and Teflon surfaces. Additionally toxicity studies were performed using the human colon carcinoma CaCo-2 cell line. Several new functionalized guanidinium based ILs showed high densities, low contact angles with Teflon, low surface tensions as well as a non-toxic behaviour.     

Anti-ulcer activity of Smithia conferta in various animal

Smithia conferta Sm. (Leguminasae), is a commonly used plant in Indian traditional medicine. In the current study anti-ulcer activity of its petroleum ether, alcohol and aqueous extracts of leaves were investigated using different animal models. All extracts were also subjected to phytochemical analysis and their toxic potential. Petroleum ether extract was found to contain steroids; alcohol extract revealed the presence of isoflavonoids, alkaloids and carbohydrates; while aqueous extract was found to contain amino acids, carbohydrates and flavonoids. S. conferta aqueous and alcoholic extracts were found to be non-toxic up to 5000 mg/kg dose level while petroleum ether extract was safe only up to a dose of 2000 mg/kg after single dose administration of the extracts.During confirmation of the claimed anti-ulcer activity, treatment with aqueous and alcoholic extracts showed significant reduction in ulcer index, free acidity as well as total acidity in pylorus ligated rats. However, petroleum ether extract showed relatively less profound reduction in all these indices. The anti-ulcer activity observed in aqueous extract treatment group was nearly equivalent to the standard group.     

Ionic liquids with herbicidal anions

Ionic liquids with herbicidal anions (named herbicidal ionic liquids—HILs) were synthesized and characterized. The combination of two active chemicals as the [cation][anion] form in a single moiety reduced the number of additional chemicals required per application. HILs ([cation][MCPA]) exhibited higher biological activity than currently used salts of MCPA, and involved pesticides of a multidirectional activity ([plant growth regulator][MCPA]). Acute toxicity of HILs could be controlled by appropriate selection of cation type. These salts had chemical and thermal stability, and showed substantially lower water solubility than starting herbicides, thus reducing soil and groundwater mobility.     

典型蓝藻多肽的浓度水平、毒性及光化学行为的研究进展

由于人为活动和气候变化,蓝藻水华污染已成为全球性环境问题。水华发生时藻类产生的毒性代谢物蓝藻多肽大量释放至水中,对生态系统和人类健康造成风险。本文系统梳理了包含微囊藻毒素在内的6种典型蓝藻多肽的浓度水平和毒性,并探讨了蓝藻多肽的光化学行为。结果显示,蓝藻多肽的浓度水平一般处于μg/L范围,其主要毒性位点为肝、肾和神经系统,致毒浓度LC₅₀在μmol/L范围。蓝藻多肽以间接光解为主,半衰期长短与蓝藻多肽本身的结构和所含的氨基酸基团种类以及环境水体pH大小等有关。本研究为解析蓝藻多肽的环境影响和环境归宿提供参考。     

Ecotoxicity of, and remediation with, engineered inorganic nanoparticles in the environment

This article presents recent developments on the use of inorganic nanoparticles (NPs) for environmental remediation in polluted soil, water and gas. The number of publications on these topics has grown exponentially in recent years, especially those focused on wastewater treatment. Among these topics, removal of metals has become the most popular, although some works relate to the use of nanomaterials for the elimination of nutrients (e.g., nitrogen and some persistent organic pollutants). However, this growth has not been accompanied by knowledge about the behavior of NPs once used and released into the environment. In this article, we also comment upon the current situation with respect to NP toxicology (nanotoxicology). A remarkable number of different toxicology tests has been applied to NPs, often making it very difficult to interpret or to generalize the results. We analyze in detail the bioluminescence, Daphnia magna and other tests, and give some preliminary results obtained in our work.     

Characterisation of soot particulates from fire retarded and nanocomposite materials, and their toxicological impact

Polyamide 6 (PA 6) and polypropylene (PP) containing fire retardants, nanofillers or a combination of both additives have been investigated using the steady state tube furnace (ISO TS 19700). The samples were tested under three different fire conditions, to determine the effect of additives on the soot production or toxic product yields. The particle size distribution of the soot was investigated with a cascade impactor, and the separated soot fractions examined by SEM. The predicted deposition based on aerodynamic size of particulates in the human respiratory tract shows clear differences between the pure polymer and its additive counterparts. In all ventilation conditions the virgin polymer produces the least amount of soot, both the additives used (fire retardant and nanoclay) increase the amount of soot, mainly within 0.5-1.0 μm range, for each fire condition. A large contribution to the total soot mass originated particles smaller than 0.5 μm.     

On the maximum total sample size of a group sequential test about bivariate binomial proportions

For testing “univariate” binomial proportions, it has been proven that, under mild conditions, there exist group sequential designs which satisfy the pre-specified Type I error and power of the single-stage design while the sample size is bounded above by that of the single-stage design (Kepner and Chang, 2003). In this article, we extend this result and prove the existence of such group sequential designs for various decision rules in the space of bivariate binomial variables. We also demonstrate how to obtain the actual group sequential designs for detecting changes in bivariate binomial variables.     

Synthesis, characterization and preliminary toxicity assays of NIR-active Au-silicate nanoparticles through a sol-gel processing

Monodisperse Au-silicate nanoparticles (10.7±1.6 nm in diameter) were prepared by reduction of aqueous solution containing 2 mM HAuCl₄ with sodium citrate (1 wt.%) in a hydrosol, in which small clusters of silicate formed by hydrolysis and polymerization of 3-aminopropyltrimethoxysilane (APTMS). APTMS covalently linked to reduced gold particles through its -NH₂ end-group. UV-vis spectra of the obtained Au-silicate nanoparticles showed a peak at ∼690 nm due to the interface effects between the Au and the silicate matrix. The Au-silicate nanoparticles exhibited near-IR (NIR) sensitivity. Cytotoxicity and limited hemocompatibility in vitro for the prepared Au-silicate nanoparticles were also investigated. It was shown that at lower concentration (<1 μg/ml), the Au-silicate nanoparticles were biocompatible without causing any cytotoxicity and hemolysis.