Use of glycerol,waste glycerol from biodiesel production and other protic solvents in bioactive α,β-unsaturated ketones synthesis

Glycerol is the main co-product from biodiesel production and has been recognized as a sustainable solvent. Herein, we used glycerol and waste glycerol in synthesis of two bioactive α,β-unsaturated ketones (E,E)-1,5-diphenylpenta-2,4-dien-1-one (1) and (E,E)-2,6-dibenzylidenecyclohexanone (2), using aldol mono- and di-condensation reactions, respectively. Crude yield values were calculated from product mass after precipitation and drying. Purity was measured by High Performance Liquid Chromatography with Photodiode Array (HPLC-PAD) using analytical curves and reference compounds. Glycerol and waste glycerol were able to furnish 1 and 2 in higher crude yields and HPLC-PAD purities values than other protic solvents (ethanol, methanol, PEG-400 and water). In order to investigate reasons of glycerol efficiency when compared to water efficiency, we performed computational calculations using Density Functional Theory (DFT). Theoretical predictions confirmed the E1cB mechanism, as well as favourable energy barrier using glycerol in comparison to water, corroborating their sustainable properties. In addition, waste glycerol from corn and sunflower oil transesterifications were used in the synthesis of 1 and 2 for four recycles, displaying good crude yields and HPLC-purities.     

Abstracts

Dental enamel is the most mineralized tissue of vertebrate organisms. Enamel biosynthesis is initiated by the secretion, processing, and self-assembly of a complex mixture of proteins. The formation of an ordered enamel organic extracellular matrix (ECM) seems be a crucial step for the proper formation of mineral phase. Polarizing microscopy demonstrates that the ordered supramolecular structure of the secretory-stage enamel organic ECM is strongly birefringent. In the present work we analyzed the birefringence of secretory-stage enamel organic ECM in amelogenin (Amelx)- and enamelysin (Mmp20)-deficient mice. Female Amelx^+/? animals showed significant reduction in optical retardation values when compared with the Amelx^+/+ subgroup (p = 0.0029). The secretory-stage enamel organic ECM of the Amelx^?/? subgroup did not exhibit birefringence. The secretory-stage enamel organic ECM of Mmp20^?/? mice showed a significant decrease in optical retardation as compared with Mmp20^+/+ and Mmp20^+/? mice (p = 0.0000). Mmp20^+/? and Mmp20^+/+ mice exhibited similar birefringence (p = 1.0000). The results presented here support growing evidence for the idea that the birefringence of secretory-stage enamel organic ECM is influenced by the ordered supramolecular organization of its components.     

职业性有机溶剂中毒15例临床表现和影像学特征分析

目的 探讨职业性有机溶剂中毒的临床表现、神经影像学特征、治疗及预后。方法 回顾性分析15例职业性有机溶剂中毒患者的临床资料。结果 15例患者均急性或亚急性起病,有明确的有机溶剂职业接触史,主要临床表现包括头晕(73.3%)、认知功能下降(60%)、锥体束损害(53.3%)、颅内高压综合征(46.7%)、意识障碍(33.3%); 其中14例患者头颅磁共振成像(Magnetic resonance imaging,MRI)显示为弥漫性脑组织肿胀,以双侧大脑半球白质为主,呈“火焰状”,10例累及双侧基底节(苍白球),8例累及双侧小脑齿状核,呈“肾形”改变,5例累及双侧丘脑; 所有患者使用脱水剂、糖皮质激素及高压氧等综合治疗后,其中12例患者好转出院,无或仅遗留轻微后遗症,3例患者无明显改善,预后差。结论 职业性有机溶剂中毒以头晕、认知功能下降、锥体束损害、颅内高压综合征及意识障碍等中毒性脑病表现为主,典型头颅MRI为双侧大脑半球白质、苍白球及小脑齿状核对称性病变,结合患者职业接触史需考虑本病; 早期、长程、足量给予脱水剂、糖皮质激素及高压氧等综合治疗,大多数患者预后良好。     

不同直径半夏药材的质量差异比较研究

目的:考察不同直径半夏药材的质量差异,为其资源的合理利用提供参考。方法:以来自国内四大药材市场、2家公司的65批商品半夏为样品,采用游标卡尺测定其直径后,用分药筛将其筛分为不同直径范围(0.5 cm≤d≤0.8 cm、0.8 cm0.05)。73批半夏对口药材的直径主要分布在0.6~1.8 cm之间,平均重量占比为95.54%。若以2015年版《中国药典》(一部)规定的直径标准(1~1.5 cm),73批半夏对口药材中仅8批符合要求,合格率为10.96%;若适当扩大直径范围为0.7~1.5 cm,有54批符合要求,合格率为73.97%;当直径范围扩大为0.7~1.6 cm时,有68批符合要求,合格率达93.15%。结论:不同直径的半夏药材之间质量无明显差异。结合各产地半夏的直径分布情况,可将相关标准中规定的直径大小由"1~1.5 cm"扩大为"0.7~1.6 cm",避免资源浪费。     

Nutrient recovery from pigeon dropping by using exotic earthworm Eisenia fetida

Pigeon dropping is a kind of organic waste which can be transformed easily into organic manure by vermicomposting with exotic earthworm Eisenia fetida. In the present study, a pigeon excreta was collected from roof tops. The pigeon excreta was mixed with cattle dung with the ratios as 10%, 20%, 30%, 40% and 50% respectively, in plastic containers; meanwhile, those proposal were name as C₁₀, C₂₀, C₃₀, C₄₀ and C₅₀ respectively. Feed mixtures were allowed to decompose (pre-vermicomposting without earthworm) for 20–25 days. After decomposition, 20 hatchlings of E. fetida were put in each concentration after weighing. Cattle dung (without pigeon excreta) was kept as the control. The physico-chemical analysis of initial feed mixture and final product after vermicomposting was also done to measure the changes in the feed mixtures from the initial to the final states. There were increases in the content of N (52.35%), P (115.79%), K (39.97%) and EC (56.16%) but decrease in those of OC (-15.49%), OM (-15.49%), pH (-7.92%) and Ca (-39.62%) from the initial to the final product. The highest population size of earthworms and minimum mortality rate was observed in C₃₀ feed mixture. Thus, the present study indicated that cattle dung mixed with 30% (w/w) pigeon excreta waste may be a good choice for vermicomposting.     

Two-stage vertical flow multi-soil-layering (MSL) technology for efficient removal of coliforms and human pathogens from domestic wastewater in rural areas under arid climate

This paper investigates the removal efficiency of organic matter, nitrogen, phosphorus, coliforms and pathogens from rural domestic wastewater in a two-stage vertical flow multi-soil-layering (MSL) system. The effects of wastewater quality, season and arid climate conditions on pollutants removal efficiency by the system were examined for one year. The experimental setup included two similar MSL systems composed of two layers: soil-mixture-layers (SML) and gravel permeable layers (PL) that are arranged in a brick like pattern. The applied hydraulic loading rate was 1000 L m^?2 day^?1. Results showed that most of the physicochemical contaminants elimination occurred while the wastewater percolated through the first MSL stage. The second stage demonstrated an improvement in the reduction of all pollutants, especially fecal bacteria indicators and pathogens. The mean overall removal rates performed by the two-stage MSL system were 97% for TSS, 96% for BOD₅, 91% for COD, 96% for TN and 95% for TP. For bacterial indicators, the combination of two-stage MSL system achieved high log removals between 2.21 and 3.15 log units. Contaminants reduction processes in MSL technology are more dependent on internal than external environmental factors. The effectiveness of the two-stage MSL system to treat domestic wastewater was strongly influenced by wastewater quality. Significant relationships between influent contaminants level and their removal efficiency were found. The efficiency of MSL technology to reduce contaminants is not sensitive to season and air temperature fluctuations. This is due to the capacity of MSL system materials to withstand the air temperature variation, which highlights one of the advantages of MSL’s technology. Wastewater quality is the most important factor affecting the removal of contaminants in the MSL, which could be a critical parameter to considered when designing MSL system. Two-stage MSL system achieved a high treated wastewater quality amenable for treated wastewater reuse in agriculture recommended by Moroccan code of practice. Therefore, the combination of two-stage vertical flow MSL system could be considered an efficient and promising domestic wastewater treatment solution in arid countries to promote environmental protection and wastewater reuse.     

Toxicological and ecotoxicological properties of gas-to-liquid (GTL) products. 2. Ecotoxicology

Gas-to-liquid (GTL) products are synthetic hydrocarbons produced from natural gas using a catalytic process known as the Fischer–Tropsch process. This process yields a synthetic crude oil that consists of saturated hydrocarbons which can subsequently be refined to a range of products analogous to those obtained from petroleum refining. However, in contrast to their petroleum-derived analogs, GTL products are essentially free of unsaturated or aromatic compounds and do not contain any sulfur-, oxygen-, or nitrogen-containing compounds. Under new chemical substance notification requirements, an extensive testing program covering the entire portfolio of GTL products has been undertaken to assess their hazardous properties to human health and environment. The results of these studies have been summarized in a two-part review. Part 1 provides an overview of the mammalian toxicity hazardous properties of the various GTL products. This second part of the review focuses on the aquatic, sediment, terrestrial, and avian toxicity studies which assess the ecotoxicological hazard profile of the GTL products. Many challenges were encountered during these tests relating to dosing, analysis and interpretation of results. These are discussed with the intent to share experiences to help inform and shape future regulatory mandates for testing of poorly soluble complex substances. As was the case with the mammalian toxicology review, there were a few cases where adverse effects were found, but overall the GTL products were found to exert minimal adverse ecotoxicological effects and these were less severe than effects observed with their conventional, petroleum-derived analogs.