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151.
Hossein Reza Darabi Kioumars Aghapoor Abbas Darestani Farahani Farshid Mohsenzadeh 《Environmental Chemistry Letters》2012,10(4):369-375
This investigation discloses a greener reaction to prepare pyrrole derivatives. Metal-free catalysts are greener alternatives to existing metal catalysts in synthetic organic chemistry. Indeed, transition metals are often costly and toxic. They may be found as traces in health reaction products such as pharmaceuticals. Alternatively small organic molecules termed “organocatalysts” allow the synthesis of valuable products without traces of toxic metals. Here, we show for the first time the use of vitamin B1 as new organocatalyst for the Paal–Knorr pyrrole synthesis under ambient conditions. Reaction conditions were optimized for the reaction of hexane-2,5-dione with 4-methoxyaniline. Ethanol was the most effective solvent. The conversion was quantitative using vitamin B1, by comparison with a low yield of 30?% without catalysis. The best conditions were performed in ethanol with 5?mol % of vitamin B1 during 1?h. This reaction was tested using various aromatic amines. To conclude the use of vitamin B1 for the Paal–Knorr pyrrole, cyclocondensation has mild reaction conditions, is simple to perform, and gives moderate to excellent yields. It is therefore a promising reaction for the preparation of various pyrrole derivatives. 相似文献
152.
Wenjing Lu Yawar Abbas Muhammad Farooq Mustafa Chao Pan Hongtao Wang 《Frontiers of Environmental Science & Engineering》2019,13(2):30
153.
Abbas Rezaee Hossinali Rangkooy Ali Khavanin Ahmad Jonidi Jafari 《Environmental Chemistry Letters》2014,12(2):353-357
Air pollution is a major issue leading to many serious illnesses. Exposure to formaldehyde may occur by breathing contaminated indoor air, tobacco smoke, or ambient urban air. Exposure to formaldehyde has been associated with lung and nasopharyngeal cancer. Therefore, there is a need for methods to degrade formaldehyde. Here, we studied the photocatalytic decomposition of gaseous formaldehyde over nanosized ZnO particles on bone char. The conditions were UV/bone char, UV/ZnO nanoparticles, and UV/ZnO-bone char in continuous flow mode. We investigated the effects of humidity, initial formaldehyde concentration, and residence time on decomposition of formaldehyde. Agglomeration of ZnO particles in the bone char pores was characterized by Brunauer, Emmett, and Teller surface area, and scanning electron micrograph. Results show that maximum decomposition efficiency of formaldehyde was 73 %. The optimal relative humidity was by 35 %. Findings also indicated that immobilization of ZnO nanoparticles on bone char has a synergetic action on photocatalytic degradation. This is explained by the strong adsorption of formaldehyde molecules on bone char, resulting in higher diffusion to the catalytic ZnO and thus a higher rate of photocatalysis. 相似文献
154.
Samira Valiyari Rana Jahanban-Esfahlan Fateme Zare Shahneh Saeid Yaripour Abbas Delazar 《毒物与环境化学》2013,95(7):1208-1220
Breast cancer is the most common cancer in women. Therefore, there is an urgent need to identify and develop therapeutic strategies against this deadly disease. This study is the first to investigate the cytotoxic and apoptotic effects of Scrophularia oxysepala in MCF-7 human breast cancer cells. Dichloromethane, methanol and n-hexane extracts of Scrophularia oxysepala were examined. The 3-(4,5-dimethylethiazol-2-yl)-2,5-diphenyltetrazolium (MTT) reduction and trypan-blue exclusion assays were performed in MCF-7 cells as well as control cell line MCF10A to analyze the cytotoxic activity of the plant. Furthermore, the apoptosis-inducing action of extracts of the plant was evaluated using cell death detection ELISA, the terminal deoxynucleotide transferase dUTP nick end labeling (TUNEL) assay, Western blotting and real-time polymerase chain reaction (PCR). The results showed that dichloromethane and methanol extracts significantly inhibited cell growth and viability without inducing damage to MCF10A cells. Cell death detection ELISA, morphological changes of cells in TUNEL assay, Western blot detection of poly (ADP-ribose) polymerase (PARP) cleavage and increase in the mRNA expression levels of p-53, caspase-3 and c-myc showed that the induction of apoptosis was the main mechanism of cell death. Our results strongly suggest that this plant may contain potential bioactive compound(s) for the treatment of breast cancer. 相似文献
155.
156.
Lianfeng Du Jiaojiao Zhao Farhat Abbas Wenke Liu 《Environmental Chemistry Letters》2013,11(4):385-390
This report shows a higher soil quality under medicinal plants versus food-crop plants. Long-term continuous cultivation of food crops induces changes of soil properties that can lead to fertility loss and, in turn, decline of food productivity. Effect of cropping on soil changes has been studied mainly for food crops and vegetables worldwide, whereas soil changes in herbal fields are scarcely known. Therefore, we compared here soil nutrients and soil chemical properties of herbal fields, cultivated with Chinese medicinal plants, and food-crop fields. Fields are located at the famous traditional planting base of Chinese medicinal plants in Anguo, China. The results showed that in herbal fields, soil nitrate, available P, soil organic matter (SOM), and electrical conductivity decreased with soil depth, whereas soil pH and soil water content increased with depth. In herbal fields, soil nitrate, available P contents, and soil electrical conductivity were higher than those of food-crop fields at various soil layers. SOM and soil water content were similar in herbal and food-crop fields. Soil pH of herbal fields at 0–20 cm was lower than those of food-crop fields. Findings show overall that soil nutrient accumulation and changes under medicinal plants are higher than food-crop fields. 相似文献
157.
Azhar Abbas T.S. Amjath-Babu Harald Kächele Muhammad Usman Klaus Müller 《国际发展与全球生态学杂志》2016,23(1):98-111
South Asia faces increasing flooding risks due to climatic and socio-economic changes. Various measures have been adopted by the governments of the countries in this region. However, these measures are not adequate to protect the vulnerable communities from ever-increasing flood losses. This study assesses the policy and planning processes and flood-related scientific research in India, Pakistan and Bangladesh. Based on a systematic review, a comparison of the existing flood management systems of the three countries is undertaken, and a framework for sustainable flood management in the region is suggested. Insights from the literature show that Bangladesh has been able to develop an effective governance structure to address flood hazards, while Pakistan’s approach to flood management planning is found to be largely inadequate. This inadequacy is mainly attributed to missing links in policy formulation and planning processes, along with a lack of institutional coordination. The results of the literature analysis reveal poor support from scientific research focusing on flooding issues in the case of Pakistan, while Bangladesh and India seem to have benefited from research support in formulating their flood management strategies. Based on these findings, an alternative framework is suggested, emphasizing the need to enhance institutional linkages, community participation and evidence-based research. 相似文献
158.
Hossain Mohammad Belal Runu Umme Hani Sarker Md. Milon Hossain Md. Kamal Parvin Afroza 《Environmental geochemistry and health》2021,43(10):4235-4249
Environmental Geochemistry and Health - Vertical heavy metal profiling reflects the history of the deposition of metals and helps to understand the characteristics of accumulation in various layers... 相似文献
159.
Frontline healthcare workers (HCWs) looking after COVID-19 patients are at high risk of developing mental health problems. Both preventive and interventional initiatives are essential, therefore, to maintain and improve the mental health of HCWs and ultimately to enhance the quality of care that they provide. This qualitative content analysis study, conducted in Iran between September 2020 and February 2021, involved the gathering of data on the issue through face-to-face interviews with 22 HCWs working directly with COVID-19 patients. Data analysis led to the generation of 163 codes, 45 categories (16 risk factors and 29 consequences), and 9 themes. Overall, the results suggest that caring for a patient with COVID-19 is associated with positive and negative psychological impacts. Measures such as increasing sensitivity to crisis situations, self-adjustment skills training, and identifying signs of job burnout owing to moral conflicts can reduce or eliminate the risk of negative psychological consequences among HCWs. 相似文献
160.
Khani Masoud Mousavi Seyyed Ebrahim Pahlavanzadeh Hassan Ale Ebrahim Habib Mozaffari Abbas 《Environmental science and pollution research international》2019,26(10):9686-9696
Environmental Science and Pollution Research - In the present study, a detailed investigation was carried out on MoO3 alumina-supported catalysts behavior in selective catalytic reduction of SO2 to... 相似文献