Structural Decomposition Analysis of Raw Material Consumption

The aim of this article is to quantify the drivers for the changes in raw material consumption (domestic material consumption expressed in the form of all materials extracted and used in the production phase) in terms of technology, which refers to the concept of sustainable production; the product structure of final demand, which refers to the concept of sustainable consumption; and the volume of final demand, which is related to economic growth. We also aim to determine to what extent the technological development and a shift in product structure of the final demand compensate for the growth in final consumption volume. Therefore, we apply structural decomposition analysis (SDA) to the change in raw material consumption (RMC) of the Czech Republic between 2000 and 2007. To present the study in a broader context, we also show other material flow indicators for the Czech Republic for 2000 and 2007. Our findings of SDA show that final demand structure has a very limited effect on the change in material flows. The rapid change in final demand volume was not compensated for crude oil, metal ores, construction materials, food crops, and timber. For the material category of non‐iron metal ores, even the change in technology contributes to an increase in material flows. The largest relative increases are reported for non‐iron metal ores (38%) and construction materials (30%). The main changes in material flows related to the Czech Republic are driven by exports and enabled by imports, the main source of these increased material flows. This emphasizes the increasing role of international trade.     

Synthesis of alkali metal hexahydroaluminate complexes using dimethyl ether as a reaction medium

A novel method of preparation of hexahydroaluminate complexes M₃AlH₆ (M = Li, Na or K) from the corresponding alkali metal hydride and tetrahydroaluminate has been explored, using dimethyl ether (Me₂O) as a solvent at near-ambient temperatures. The results are compared with those obtained using a recently established mechanochemical approach. Characterization of the products by powder X-ray diffraction revealed M₃AlH₆ to be formed in high yield for M = Li and Na, but not for M = K. The attempted preparation of Li₂NaAlH₆ and Li₂KAlH₆ was unsuccessful.     

A comparison of ferric-chelate reductase and chlorophyll and growth ratios as indices of selection of quince,pear and olive genotypes under iron deficiency stress

Quince (Cydonia oblonga Mill.), pear (Pyrus communis L.) and olive (Olea europaea L.) genotypes were evaluated for their tolerance to iron deficiency stress by growing young plants in three types of aerated nutrient solutions: (1) with iron, (2) without iron or (3) low in iron and with 10 mM bicarbonate. Plants were obtained either from rooted softwood cuttings or from germination of seeds. The degree of tolerance was evaluated with several indices: (1) the chlorophyll content, (2) the root Fe³⁺ reducing capacity and (3) the whole plant relative growth. Fifteen hours before Fe³⁺ reducing capacity determination, iron was applied to the roots of plants with iron-stress, since this method resulted in increasing the reductase activity. All quince and pear genotypes increased the root Fe³⁺ reducing capacity when grown in the treatments for iron-stress, in relation to control plants of the same genotypes. In olive cultivars, the Fe³⁺ reducing capacity was lower in the iron-stress treatments than in the control one. Studying the relationship between relative growth and chlorophyll content for each genotype under iron-stress, in relation to both indices in control plants, a classification of species and genotypes was established. According to that, most olive cultivars and some pear rootstocks and cultivars appear more iron-efficient than quince rootstocks. Our study shows that in some woody species, determining root Fe³⁺ reducing capacity is not the best method to establish tolerance to iron deficiency stress.     

肝素钠的生产及其存在的问题及解决的方法（Ⅱ）

本文就粗品肝素钠生产的原料控制硬件设施管理和环保等方面进行了论述，介绍了一些改进的方法和措施，并就该方面的的一些问题进行了探讨，提出了解决的方法。     

Tungsten-based material as promising new lead-free gamma radiation shielding material in nuclear medicine

PurposeThe main objective of this study was to evaluate the efficacy of tungsten carbide as new lead-free radiation shielding material in nuclear medicine by evaluating the attenuation properties.Materials and methodsThe elemental composition of tungsten carbide was analysed using Field-Emission Scanning Electron Microscopy (FESEM) with energy dispersive X-ray (EDX). The purity of tungsten carbide was 99.9%, APS: 40–50 µm. Three discs of tungsten carbide was fabricated with thickness of 0.1 cm, 0.5 cm and 1.0 cm. Three lead discs with similar thickness were used to compare the attenuation properties with tungsten carbide discs. Energy calibration of gamma spectroscopy was performed by using ¹²³I, ¹³³Ba, ¹⁵²Eu, and ¹³⁷Cs. Gamma radiation from these sources were irradiated on both materials at energies ranging from 0.160 MeV to 0.779 MeV. The experimental attenuation coefficients of lead and tungsten carbide were compared with theoretical attenuation coefficients of both materials from NIST database. The half value layer and mean free path of both materials were also evaluated in this study.ResultsThis study found that the peaks obtained from gamma spectroscopy have linear relationship with all energies used in this study. The relative differences between the measured and theoretical mass attenuation coefficients are within 0.19–5.11% for both materials. Tungsten carbide has low half value layer and mean free path compared to lead for all thickness at different energies.ConclusionThis study shows that tungsten carbide has high potential to replace lead as new lead-free radiation shielding material in nuclear medicine.     

Dietary factors affecting the urinary mutagenicity assay system. I. Detection of mutagenic activity in human urine following a fried beef meal

Studies have been conducted to determine whether the mutagens in fried beef ingested by human subjects are excreted in the urine. Urine samples were collected from individuals on liquid or regular diets before and after a fried beef meal. The mutagenic activity of the samples was tested in the Ames Salmonella/microsome assay system. The results showed that in individuals on liquid diets, most of the urinary mutagenic activity is recovered within 2-6 h after consuming a fried beef meal. In one individual tested, mutagenic activity was found in urine samples obtained 6-15 h after the fried beef meal. No mutagenic activity was detected in any of the urine samples obtained 15-24 h following the meal. In individuals on a regular diet, however, mutagenic activity was frequently observed in urine samples obtained 16-24 h following the fried beef meal, although the mutagenic activity was not as great as that in the preceding 16 h. It appears that the mutagenic agents generated by the frying of beef are ingested, absorbed, and excreted by the human body in biologically detectable quantities. These results suggest that subjects should abstain from fried beef at least one day prior to and during urine mutagenicity screening.     

水蒸汽蒸馏巴柑檬叶和果皮精油化学成分的研究

巴柑檬是我们第一次从国外引种成功的一种名贵香料植物。用色谱-质谱-计算机联用技术、毛细管气相色谱保留指数法和标准品叠加法分析了水蒸汽蒸馏巴柑檬叶和果皮精油的化学成分。从叶和果皮精油分离出来的220个和200个成分中,分别鉴定出48个和57个成分。鉴定组分的含量分别占叶和果皮精油的99.80％和98.54％。叶精油与果皮精油在化学成分方面的主要区别是叶油中萜烃化合物含量较低,而萜醇类化合物含量较高。     

Development and specificity of inhibitory terminal arborizations in the central nervous system

This study examined the morphological development of single inhibitory arborizations in the gerbil central auditory brain stem. Using a brain slice preparation, neurons of the medial nucleus of the trapezoid body (MNTB) were filled with horseradish peroxidase (HRP), and their complete arborizations were analyzed along the tonotopic axis of the lateral superior olive (LSO). The projections in neonatal animals displayed well-defined arbors that were ordered appropriately within the LSO. It was evident from the axonal pathways that the MNTB afferents could correct for projection errors after reaching the postsynaptic population. As development progressed, a number of arbors established diffuse or inappropriate projections within the LSO. These immature arborizations were no longer apparent by 18–25 days postnatal. The anatomical specificity of arbors at 12–13 and 18–25 days was quantified by measuring the distance that terminal boutons spread across the frequency axis. There was a significant reduction of this distance in older animals. In addition, there was a significant reduction in the mean number of boutons per arbor between 12–13 days and 18–25 days. The maximum nucleus cross-sectional area continued to increase through 15–16 days, indicating that the refined arbors occupied an even smaller fraction of the postsynaptic structure. Taken together, these observations suggest that central inhibitory arbors form exuberant contacts that must be eliminated during development.     

3-Hydroxypropyl amide formation from 1-aminocyclopropane-1-carboxylic acid by a cell-free ethylene-forming system from olive leaves

The low ethylene yield in a cell-free ethylene-forming system from olive tree leaves ( Olea europaea L. cv. Picual) was investigated. During the incubation, 1-aminocyclopropane-1-carboxylic acid (ACC) was extensively transformed into 3-hydroxypropyl amide (HPA). Enzyme extract, Mn²⁺ and oxygen are responsible for this reaction. Horseradish peroxidase (EC 1.11.1.7) can substitute for the enzyme extract in this reaction. HPA formation could be one reason for the poor in vitro conversion efficiency of ACC to ethylene.