Photodegradation of new amino acid derivatives suitable for chelating agents in pulp bleaching applications

The purpose of this study was to evaluate photodegradabilities of the following new low-nitrogen chelating agents: N-bis[(carboxymethoxy)ethyl]glycine (compound 1), N-bis[(1,2-dicarboxyethoxy)ethyl]glycine (compound 2) and N-bis[(1,2-dicarboxyethoxy)ethyl]aspartic acid (compound 3). At first photodegradation of these chelating agents as uncomplexed Na-compound 1–3 and Cu(II) complexes were tested, both in lake and distilled water, by exposing them to near-UV region radiation at the range of 315–400 nm. Uncomplexed Na-compounds 2 and 3 were selected to sunlight exposure experiments carried out in lake and distilled water. Compound 3 was also tested in sunlight as Cu and Ca complexes in both solutions. Photodegradation of Na₆-compound 3 in distilled water was studied by exposing it to radiation at the wavelength of 253.7 nm. Photodegradation products were analysed by means of GC-MS (gas chromatography with mass selective detector).

The results demonstrated that compound 1 was quite photostable even as Cu complex while compounds 2 and 3 were found to be photodegradable. Over 90% reduction of compound 3 was achieved during one week and 80% reduction of compound 2 in two weeks' time when they were added as Na salt to lake water and exposed to sunlight. Compound 3 as Cu complex degraded totally in the sunlight in less than one week. In the case of compound 3, the degradation rate decreased depending on the counter cation in the order Cu > Na  Ca. The study demonstrated that photodegradation of Na₆-compound 3 does not result in total mineralization of the compound. A photodegradation pathway for Na₆-compound 3 is proposed.     

Synthesis of some novel (2-oxo-3-(arylimino) indolin-1-yl)-N-aryl acetamides and evaluation as antimicrobial agents

A series of sixteen 2-oxo-3-(arylimino) indolin-1-yl)-N-aryl acetamide derivatives were synthesized, characterized by physical and spectral data (IR, ¹H nuclear magnetic resonance (NMR), and mass spectrometry), and evaluated for their antibacterial and antifungal activities against various pathogenic microorganisms. Some of the synthesized compounds showed promising antibacterial and antifungal activities, the best being 2-(3-(4-chlorophenylimino)-2-oxoindolin-1-yl)-N-(3-methoxyphenyl) acetamide.     

Cellular damages in the Allium cepa test system, caused by BTEX mixture prior and after biodegradation process

Petroleum and derivatives have been considered one of the main environmental contaminants. Among petroleum derivatives, the volatile organic compounds benzene, toluene, ethylbenzene and xylene (BTEX) represent a major concern due to their toxicity and easy accumulation in groundwater. Biodegradation methods seem to be suitable tools for the clean-up of BTEX contaminants from groundwater. Genotoxic and mutagenic potential of BTEX prior and after biodegradation process was evaluated through analyses of chromosomal aberrations and MN test in meristematic and F₁ root cells using the Allium cepa test system. Seeds of A. cepa were germinated into five concentrations of BTEX, non-biodegraded and biodegraded, in ultra-pure water (negative control), in MMS 4 × 10⁻⁴ M (positive control) and in culture medium used in the biodegradation (blank biodegradation control). Results showed a significant frequency of both chromosomal and nuclear aberrations. The micronucleus (MN) frequency in meristematic cells was significant for most of tested samples. However, MN was not present in significant levels in the F₁ cells, suggesting that there was no permanent damage for the meristematic cell. The BTEX effects were significantly reduced in the biodegraded samples when compared to the respective non-biodegraded concentrations. Therefore, in this study, the biodegradation process showed to be a reliable and effective alternative to treat BTEX-contaminated waters. Based on our results and available data, the BTEX toxicity could also be related to a synergistic effect of its compounds.     

七种萘有机化合物对活性污泥的抑制作用

本文依据呼吸法测定的微生物耗氧速率,研究了七种萘有机化合物对活性污泥的抑制作用,建立了微生物相对呼吸速率与抑制物浓度之间的定量方程,据此方程计算了七种化合物在废水生物处理系统中的建议最高可容许浓度以及对微生物呼吸的半抑制浓度EC_（50）,并得到了EC_（50）与正辛醇-水分配系数lgK_（ow）之间的线性回归方程。     

The solar transformity of petroleum fuels

Petroleum fuels are the primary energy basis for transportation and industry. They are almost always an important input to the economic and social activities of humanity. Emergy analyses require accurate estimates with specified uncertainty for the transformities of major energy and material inputs to economic and environmental systems. In this study, the oil refining processes in Italy and the United States were examined to estimate the transformity and specific emergy of petroleum derivatives. Based on our assumptions that petroleum derivatives are splits of a complex hydrocarbon mixture and that the emergy is split based on the fraction of energy in a product, we estimated that the transformity of petroleum derivatives is 65,826 sej/J ± 1.4% relative to the 9.26E+24 sej/year planetary baseline. Estimates of the specific emergies of the various liquid fuels from Italian and U.S. refineries are within 2% of one another and the relationship of particular values varies with the refinery design. Our average transformity is only 1.7% larger than the current estimate for petroleum fuels determined by back calculation, confirming the accuracy of this transformity in existing emergy analyses. The model uncertainty between using energy or mass to determine how emergy is split was less that 2% in the estimate of both the transformity and specific emergy of liquid fuels, but larger for solid and gaseous products. This study is a contribution to strengthen the emergy methodology, providing data that can be useful in the analysis of many human activities.     

我国桐油发展战略与对策

桐油是我国的特产资源,其价值之高,用途之广,早已引起许多国家的重视;其化学结构之特殊,化学性质之活泼,引起许多化学工作者的兴趣,而致力于桐油化学科学的研究。我国种植油桐历史修久,远在公元前六世纪有文记载。新中国成立后,党 和政府非常重视,周总理曾亲自主持全国油桐工作会议,油桐得到了空前发展。     

反应条件对苛求芽孢杆菌胞内尿酸酶与嘌呤衍生物作用的影响

用底物尿酸的紫外吸收变化跟踪反应,用单或双底物米氏方程和初速度估算苛求芽孢杆菌胞内尿酸酶最大反应速度,按Arrenius经验公式得到该尿酸酶在pH 9.2和pH 7.4的活化能,但这些活化不能解释其在两个pH下的催化活性差异.该酶同常见嘌呤衍生物氧嗪酸、黄嘌呤和尿酸有亲和力,但对尿酸亲和力最低,且亲和力与嘌呤衍生物解离成阴离子的能力相关.在生理条件下,该酶对尿酸的亲和力相对于最适条件有显著下降.据此推测,优化静电相互作用选择性增强该酶对尿酸的亲和力是提高其成药性的可能措施之一.     

壳聚糖及其衍生物在环境污染治理中的应用

综述了壳聚糖及其衍生物在环境污染治理方面的应用进展。分别介绍了壳聚糖及其衍生物在水处理、土壤修复、大气污染防治和其他环境治理领域中对环境污染物的去除效果。对壳聚糖及其衍生物在环境治理领域的发展前景和未来的研究方向进行了展望。     

Emissions of parent, nitrated, and oxygenated polycyclic aromatic hydrocarbons from indoor corn straw burning in normal and controlled combustion conditions

Emission factors （EFs） of parent polycyclic aromatic hydrocarbons （pPAHs）, nitrated PAHs （nPAHs）, and oxygenated PAHs （oPAHs） were measured for indoor corn straw burned in a brick cooking stove under different burning conditions. The EFs of total 28 pPAHs, 6 nPAHs and 4 oPAHs were （7.9 ±3.4）, （6.5 ±1.6）×10^-3, and （6.1 ±1.4）×10^-1mg/kg, respectively. Fuel charge size had insignificant influence on the pollutant emissions. Measured EFs increased significantly in a fast burning due to the oxygen deficient atmosphere formed in the stove chamber. In both restricted and enhanced air supply conditions, the EFs of pPAHs, nPAHs and oPAHs were significantly higher than those measured in normal burning conditions. Though EFs varied among different burning conditions, the composition profiles and calculated isomer ratios were similar, without significant differences. The results from the stepwise regression model showed that fuel burning rate, air supply amount, and modified combustion efficiency were the three most significant influencing factors, explaining 72%-85% of the total variations.     

二氧化硫诱导蚕豆气孔保卫细胞死亡效应研究

采用蚕豆叶面气孔保卫细胞,研究SO2衍生物(Na2SO3与NaHSO3混合液,3:1,mmol·L-1)对细胞的致死效应.结果表明,在浓度1～4mmol·L-1内,SO2衍生物暴露3h可使表皮保卫细胞活性降低,部分细胞死亡,并致胞内活性氧和Ca2+水平升高;随着处理浓度的提高细胞死亡率增高.一定浓度的抗坏血酸(AsA)或过氧化氢酶(CAT)与SO2衍生物共同作用时,胞内活性氧水平降低,细胞死亡率下降.Ca2+螯合剂乙二醇双四乙酸(EGTA)或Ca2+通道抑制剂LaCl3与SO2衍生物共同作用时,胞内钙水平与细胞死亡率降低.LaCl3能降低H2O2诱导的细胞死亡率.研究结果表明,SO2致蚕豆保卫细胞死亡与胞内活性氧水平增高有关,活性氧能激活质膜Ca2+通道,使胞外Ca2+内流,造成胞内Ca2+浓度升高,介导细胞死亡;胁迫组气孔保卫细胞活性降低或死亡,将导致气孔运动失调.