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Marine macro-algae attenuates nephrotoxicity and hepatotoxicity induced by cisplatin and acetaminophen in rats Full text
2019
Sohail, Nida | Hira, Khan | Tariq, Amna | Sultana, Viqar | Ehteshamul-Haque, Syed
Cisplatin is considered one of the best anticancer medications often used for the treatment of various cancers even with its adverse effects. Acetaminophen (paracetamol) is a widely used analgesic-antipyretic drug that causes hepatotoxicity at higher than the effective doses. The present study assesses the nephroprotective and hepatoprotective effects of two seaweeds against cisplatin and acetaminophen toxicity in rats. Damage to the liver and kidney was induced by administering a single intraperitoneal dose of acetaminophen (600 mg/kg) or cisplatin (7 mg/kg) to groups of rats. The damage to the liver and kidney was assessed by the elevated liver (ALT, AST, ALP, LDH, electrolytes) and kidney (urea, creatinine) biomarkers. The ethanol extract of brown seaweed reversed the elevated levels of kidney and liver biomarkers along with triglycerides, cholesterol, and glucose. Among the two seaweeds, Sargassum ilicifolium showed better nephroprotective and hepatoprotective effects than the standard drug N-Acetyl-cysteine, Halymenia porphyroides showed only limited protection. Findings of this study provide evidence of nephroprotective and hepatoprotective effects of S. ilicifolium. Seaweed could be a beneficial dietary supplement to attenuate nephrotoxicity and hepatotoxicity.
Show more [+] Less [-]China’s cement demand and CO2 emissions toward 2030: from the perspective of socioeconomic, technology and population Full text
2019
Wei, Junxiao | Cen, Kuang | Geng, Yuanbo
China is the largest cement producer and carbon dioxide (CO₂) emitter in the world. The country has attracted too much attention in calculating and comparing its CO₂ emissions. However, as the second largest CO₂ emitter after the fire power industry, China’s long-term cement demand and cement-related CO₂ emission projections were not fully studied. The Chinese government, however, committed that by 2020 and 2030, China’s per capita GDP of CO₂ emissions would be lower than that in 2005 by 40–45% and 60–65%, respectively. In this paper, China’s cement demand in 2030 was projected based on the population size, urbanization rate, fixed assets investment, and per capita GDP. Furthermore, decoupling study in China’s cement industry was also involved based on the GDP and CO₂ emissions during 2001–2015. We also used the diffusion rate of 12 types of CO₂ reduction measures and two changed scenarios of clinker-to-cement ratio, to project the cement CO₂ emission factors toward 2030 after determining the accounting scope. Meanwhile, the CO₂ emissions of China’s cement industry through 2030 were projected naturally. The results showed that China’s cement output in 2030 will be approximately 2000, 1650, and 937 Mt. based on the fixed assets investment, urbanization rate, and per capita GDP respectively. The projected two scenarios cement CO₂ emission factors were resp. 407.83 and 390.02 kg CO₂/t of cement which were 42.6 and 45.1% lower than that in 2005. The cement CO₂ emissions were projected to be in the range of 366 to 818 Mt. in 2030. Additionally, China’s total cement output value has been decoupling from cement CO₂ emissions from 2012, which is mainly attributed to eliminating backward capacity, reducing excess capacity or the declining cement output. And decoupling economic from China’s cement CO₂ emissions may change to be strong or weak decoupling in the near future. As cement production is one of the factors effecting cement CO₂ emissions, the most important measure for controlling cement CO₂ emissions is a reasonable capacity utilization rate. It is therefore important to control the growth of cement CO₂ emissions by regulating the capacity utilization rate within a reasonable range. Eliminating backward capacity, removing excess capacity, controlling new capacity, staggered production, and the “going global” of cement equipment can have great impacts in controlling the total amount of cement output and CO₂ emissions.
Show more [+] Less [-]Year-round film mulching system with monitored fertilization management improve grain yield and water and nitrogen use efficiencies of winter wheat in the dryland of the Loess Plateau, China Full text
2019
Li, Tingliang | Xie, Yinghe | Gao, Zhiqiang | Hong, Jianping | Li, Li | Meng, Huisheng | Ma, Hongmei | Jia, Junxiang
Year-round film mulching in winter wheat field facilitates rainwater storage in summer fallow period and reduces water evaporation in growing reason, and then increases water use efficiency in the dryland of the Loess Plateau, China. Optimized fertilization further promotes fertilizer utilization efficiencies. In this study, plastic film mulching was extended from plant growth season to summer fallow, and fertilizers were applied by monitoring soil nutrient availability. Field trials were conducted in the dryland of the Loess Plateau over 4 years by using four types of cultivation to investigate the effects of year-round plastic film mulching with monitored fertilization on utilization efficiencies of rainwater and nitrogen (N), and winter wheat yield. The four types of cultivation were farmer practice (FP), ridge-furrow with plastic film mulching system plus conventional fertilization(RPCF), ridge-furrow with plastic film mulching system plus monitored fertilization (RPFM), and flat soil surface with plastic film mulching system plus monitored fertilization (FPFM). Our results indicate that the average yield of winter wheat in RPFM and FPFM treatments was 4491 kg ha⁻¹. Compared with FP treatment, the combined effects of monitored fertilization and film mulching(RPFM and FPFM treatments) could increase grain yield in the range of 24.7 to 42.1%. The film mulching extended to the fallow season increased the water storage in 2 m depth of soil profile, and the amount of soil water storage in the summer fallow period increased by 27 to 30% in FPFM treatment than FP treatment. After 4-year consecutive planting of wheat, the accumulation of nitrate-N in 2 m soil reached 277 kg·ha⁻¹ in the FP treatment, which is 87.7% higher than of the level at the beginning of the experiment. Seventy-five percent of nitrate-N was distributed in the soil layer of 0–120 cm. In addition, the residual nitrate-N showed downward leaching with rainfall during the experiment. The RPFM and FPFM treatments reduced the apparent loss and residual levels of soil N, whereas increased its apparent mineralization compared with FP treatment. The FPFM treatment exhibited a greater utilization of residual nitrate-N from previous years and showed a higher amount of the mineralized N from soil organic matter, therefore leading to a relatively high apparent utilization rate of N (56.7%). Considering both grain yield production and utilization efficiencies of water and N, FPFM with year-round mulching was the most effective cultivation measure for winter wheat in the Loess Plateau.
Show more [+] Less [-]Spatial variation of heavy metals and uptake potential by Typha domingensis in a tropical reservoir in the midlands region, Zimbabwe Full text
2019
Dube, Trevor | Mhangwa, Grace | Makaka, Caston | Parirenyatwa, Bridget | Muteveri, Tinashe
Pollution of aquatic ecosystems with heavy metals is now of global concern due to their dangers to human health and persistence in the environment. An investigation on the spatial distribution of heavy metals in water and sediments and the bioaccumulation potential of heavy metals by plant parts (i.e. roots, stems and leaves) of aquatic macrophyte Typha domingensis (Pers.) Steud in a tropical reservoir was carried out. The results showed no difference in spatial distribution of heavy metals (Fe, Cu, Cd, Cr, Pb, Zn, Mn) in water and sediments from the riverine to the dam wall. The concentration of heavy metals Fe, Cu, Cr and Zn in T. domingensis was of the order root > stem > leaves, but for Pb, Cd and Mn, it followed the order root > leaf > stem. The metal transfer between roots and shoots of T. domingensis followed the order Zn > Pb > Fe > Cu > Cd > Cr. The bio-concentration factor (BCF) was low (BCF < 1) for all the selected metals while the transfer factor (TF) varied among metals suggesting that T. domingensis is not an accumulator of the studied metals. The high concentration of heavy metals found in the water (0.7–16.14 mg L⁻¹) and sediments (43.6–569.18 mg kg⁻¹) present a potential risk to both ecological health and human health for the population living in the area. The results of metal concentration in water and sediments from this study are important as a baseline for future monitoring studies. Further studies on bioavailability of metals to other macrophytes and aquatic organisms are recommended.
Show more [+] Less [-]River health assessment of the Yellow River source region, Qinghai-Tibetan Plateau, China, based on tolerance values of macroinvertebrates Full text
2019
Liu, Wei | Xu, Mengzhen | Zhao, Na | Zhou, Xiongdong | Pan, Baozhu | Tian, Shimin | Lei, Fakai
For decades, the river health of the Yellow River source region (YRSR) on the Qinghai-Tibetan Plateau has been a focal issue owing to its unique geographic location and ecological functions. This study investigated the ecological status of the headwater streams, the main stem, and the tributaries of the Yellow River in the YRSR using the tolerance values of macroinvertebrates and those related to biotic indices. The macroinvertebrate assemblages of the headwater streams were characterized by lower biodiversity than the tributaries downstream, based on comparisons of taxonomical composition, functional feeding group composition, and the pollution-tolerant capacity of taxa. The headwater streams had a lower ratio (16%) of pollution-sensitive macroinvertebrate taxa than that of the tributaries downstream (30%). The biotic indices (family- and genus-level biotic indices) indicated that the ecological health of the headwater streams was comparably poorer than that of the downstream tributaries. The combined effect of vulnerable natural conditions and increasing human disturbance is likely the main cause of eco-environmental degradation in the Yellow River headwater streams.
Show more [+] Less [-]Effect of a humic acid colloid on the sorption behaviour of Sr onto soil in a candidate high-level radioactive waste geological disposal site Full text
2019
Zuo, Rui | Chen, Minhua | Lin, Yuanhui | Yang, Jie | Jin, Shuhe | Yue, Weifeng | Wang, Jinsheng | Teng, Yanguo
We explored the effect of the presence or absence of humic acid (HA) on the sorption behaviour of Sr onto soil. We examined three different experimental cases for Sr sorption: (1) sorption in the presence of only colloidal HA, (2) sorption in the presence of only soil and (3) sorption in the presence of both colloidal HA and soil (HS). A batch technique was used to study the influencing factors, including the amount of colloidal HA, solid content, pH, initial concentration of Sr and contact time. The experiments showed that the influencing factors significantly affected the sorption process. For example, in the case of soil and HS, the sorption percentage increased rapidly with increasing solid content at m/V < 20 g/L, changing from 8.35% and 37.54% to 49.09% and 77.03%, respectively. Moreover, scanning electron microscopy and Fourier transform infrared spectroscopy were used to characterize samples. The kinetics and isotherms of Sr were best described by the pseudo-second-order and Langmuir models, which indicated that the process was controlled by chemisorption and uniform monolayer sorption with constant energy on the outer surface. These findings provide valuable information for predicting strontium migration in radioactive waste disposal sites.
Show more [+] Less [-]Ozonation catalyzed by iron- and/or manganese-supported granular activated carbons for the treatment of phenol Full text
2019
Xiong, Wei | Chen, Nan | Feng, Chuanping | Liu, Yang | Ma, Ningping | Deng, Jian | Xing, Linlin | Gao, Yu
Iron- and/or manganese-supported catalysts on granular activated carbons (Fe and/or Mn/GACs) were prepared, and their catalytic activities were evaluated by using them to treat phenol and secondary petrochemical effluent via ozonation. The presence of Fe and/or Mn/GACs significantly improved the degradation and degree of phenol mineralization. Changes in dissolved ozone concentrations and the effects of carbonate and tert-butyl alcohol (TBA) indicated that the prepared catalyst enhanced the decomposition of ozone into hydroxyl radicals (·OH), which was determined to be a key factor in catalyzing the ozonation of phenol. Typical intermediate products were identified by GC-MS and HPLC analysis, and a possible degradation pathway of phenol via catalytic ozonation was proposed. The results of XPS, CV, and other experimental data indicated that introducing Fe and/or Mn increased the rate of ozone decomposition into ·OH, and also enhanced the interfacial electron transfer by Fe²⁺-Fe³⁺ and Mn²⁺-Mn³⁺-Mn⁴⁺ redox cycles, resulting in higher catalytic activity. However, the Fe-Mn/GAC surface was shown to undergo galvanic corrosion between Fe₃O₄ and MnO₂, decreasing the catalytic activity. In addition, catalytic ozonation was used to treat secondary petrochemical effluent. The results demonstrated that the Mn/GAC/O₃ system significantly improved the quality of phenol-containing wastewater in terms of its COD, TOC, NH₄⁺-N, water color, and ecotoxicity. This study gives a better understanding of the phenol treatment by catalytic ozonation using Fe and/or Mn/GAC.
Show more [+] Less [-]Immobilization of hexavalent chromium in cement mortar: leaching properties and microstructures Full text
2019
Bakhshi, Nematollah | Sarrafi, Amir | Ramezanianpour, Ali Akbar
Stabilization and solidification (s/s) of heavy metals by cementitious materials are one of the effective methods in hazardous waste management. In cement alkaline environment, Cr(VI) compounds appear in the form of chromate anion (CrO₄⁻²), which is highly soluble; it makes the implication of the s/s method challenging. Therefore, it is important to study the amount of chromium leaching from cementitious materials. The effects of Cr(VI) concentration and water-to-cement (w/c) ratio on the level of leaching of chromium from cement mortar (CM) were investigated in this study. Results indicated w/c not significantly affect the leaching of chromium in the age of 28-day but in the 90-day-old samples indicated a reduction in leaching of chromium from mortar with increasing w/c. Results from toxicity characteristic leaching procedure (TCLP) tests indicated that the efficiency of Cr(VI) stabilization was reduced with greater chromium content but was enhanced with increased w/c. In detail, results showed that only about 0.21% and 0.26% cement weight in TCLP and tank test of Cr(VI) was stabilized in CM, respectively. The results of X-ray diffraction (XRD) and scanning electron microscope (SEM/EDS) tests indicated that increasing the Cr(VI) content leads to changes in the formation of the cement main phases and microstructure of CM.
Show more [+] Less [-]Enhanced effects of ash and slag on SO3 formation in the post-flame region Full text
2019
Xiao, Haiping | Cheng, Qiyong | Li, Jian | Ge, Jinlin
The effects of slag, fly ash (formed in boiler above 1500 °C), and experimental ash (formed in muffle furnace at 815 °C) on the formation of sulfur trioxide (SO₃) were studied in a fixed bed rector. The results showed that the slag had the best catalytic effect on SO₃ formation, the effect of fly ash was second, and the effect of experimental ash was the worst. The reason may be that the forms of iron in different samples were different. Iron in the experimental ash all existed in the form of Fe₂O₃. Iron in the fly ash mainly existed in the form of composite iron oxides, such as Fe₀.₃Mg₀.₇SiO₃, Ca₃Fe₂(SiO₄)₃, and MgFe₂O₄. Iron in the slag also mainly existed in the form of composite iron oxides, such as CaFe₂O₄, MgFe₂O₄, and CaMgO₀.₈₈Fe₀.₁₂SiO₄. The different forms of iron had different effects on SO₃ formation. Composite iron oxides could produce more oxygen vacancies owing to lattice defects. This likely promoted the migration and regeneration of lattice oxygen and thus better promoted the formation of SO₃ than Fe₂O₃. Moreover, MgFe₂O₄ and Ca₃Fe₂(SiO₄)₃ could better promote SO₃ formation than CaMgO₀.₈₈Fe₀.₁₂SiO₄ and Fe₀.₃Mg₀.₇SiO₃. In addition, increasing the SO₂ concentration and O₂ concentration increased the SO₃ concentration but increasing the SO₂ concentration decreased the SO₃ formation ratio.
Show more [+] Less [-]Relationship between cadmium content in semen and male infertility: a meta-analysis Full text
2019
Zhang, Yiming | Li, Shiping | Li, Shu
Meta-analysis with high-quality studies can provide superior evidence. In this paper, we use meta-analysis to analyze the relationship between cadmium (Cd) content in semen and male infertility, and then objectively evaluate the effect of Cd on sperm quality. The objectives of this study were to update our understanding of infertility and to provide evidence to treat and prevent the infertility. We searched potentially relevant studies that were published from establishing database data to April 2018. Articles came from the databases of CNKI, Wanfang, VIP, PubMed, CMCI, and EMBASE. A total of 11 articles were included. We gathered the mean and variance of the infertility group and the control group to compare the Cd content in two groups. In total, the 11 studies include 1707 subjects, 1093 of which were in the infertility group and 614 of which were in the control group. We can get some information from this meta-analysis: SMD = 0.50 (95% Cl 0.39–0.61), Z = 8.92, P < 0.05; the funnel plot of the meta-analysis shows incomplete symmetry, which may have the publication bias. Therefore, the high content of Cd in semen is a causative factor of infertility. The Cd content in semen can be used as an indicator of sperm quality.
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