Effect of Tinospora cordifolia on the reduction of ultraviolet radiation‐induced cytotoxicity and DNA damage in PC12 cells

The safety of Tinospora cordifolia and its potential to protect against ultraviolet radiation‐induced cytotoxicity and DNA damage in PC12 cells were investigated. To evaluate the safety of T. cordifolia, cell viability and agarose gel electrophoresis were carried out using PC12 cells treated with 0 to 100 μg mL^?1 of methanol extract of T. cordifolia. T. cordifolia extracts did not show cytotoxicity ranging 0 to 100 μg mL^?1. In addition, T. cordifolia extracts significantly increased cell viability at 1 ng, 10 ng and 1 μg mL^?1 concentrations in serum‐deprived medium compared to control. To confirm the protective role against UV‐induced damage, PC12 cells alone or in the presence of 10 ng, 100 ng, or 1 μg mL^?1 of T. cordifolia extract were exposed to 250, 270 and 290 nm of UV radiation, which corresponded to doses of 120, 150 and 300 mJ cm^?2, respectively. Treatment with T. cordifolia extracts significantly increased the cell survival rate irradiated at 290 nm. In addition, T. cordifolia extracts significantly reduced cyclobutane pyrimidine dimer formation induced by UV irradiation at all wavelengths. In conclusion, T. cordifolia is not toxic and safe for cells. Our findings can support its application as phototherapy in the medical sector.     

Spatial variability and possible sources of acetate and formate in the surface snow of East Antarctica

Spatial trends of acetate(Ac~-) and formate(Fo~-) were determined in surface snow samples along a coastal-inland transect(180 km) in the ice cap region at Princess Elizabeth Land and along a coastal transect in the Amery Ice Shelf(130 km),East Antarctica.Variations in both Ac-and Fo-seem to be unrelated to the acidity of snow.Ionic balance determined for the snow samples indicate the availability of HNO3 that could undergo photolysis to produce hydroxyl radical(UOH),one of the major reactants involved in oxidation reactions with organic matter.The strong positive correlations between Ac~- and NO~-_3 in snow from both regions indicate that NO~-_3 mediatedUOH-oxidation of organic compounds in snow could be an important source of Ac-within the snowpack.On the other hand,negative correlation between Fo~- and NO~-_3 might indicate that sources other thanUOH-oxidation of organic matter may be dominant in the case of Fo~-.Higher Ac~- concentrations in the ice cap compared to the ice shelf correspond with long-range transport of biomass burning emissions to the ice cap region.Interaction of Ac~- and Fo~- with alkaline minerals could lead to their stability in the snowpack and minimize their loss from the snow surface.Resident microbial communities could also influence the budget of the carboxylic acids in snow.     

The diversification of the global mining equipment industry – Going new places?

This paper examines the profile of the global mining equipment supply industry, looking at the largest producers and consumers of mining equipment, tracking the changes in global flows of such equipment over the past decade. This paper shows that while the conventional producers of mining equipment (United States, Germany and Japan) have increased exports over the mining boom, the greater gain has been made by countries in the South (particularly China). The destination market for mining equipment has also begun to change, increasingly moving towards new mining sites (in Africa, East Asia and Latin America) and away from the traditional mining countries (Europe and North America). In SSA, China increasingly accounts for a rapidly growing share of mining equipment imports, but this trend is associated with the general increase in imports from China rather than China's resource specific engagement with SSA.     

实施简易工况法排气检测若干问题探讨

国标GB18285-2005和GB3847-2005规定在用机动车的排气检测方法选择与简易工况法标准限值的制定均由地方根据实际情况确定,虽增强了地方排气监管工作灵活性,但困难也增加了.各地在推动实施简易工况法时,检测方法的选择应重点从地方管理、地方经济、技术条件和机动车排气监督管理发展方向进行综合考虑,条件许可的地方选用简易瞬态工况法.简易工况法的初始标准限值可以先选用HJ/T 240-2005和HJ/T241-2005两个行业标准中的最松限值,然后在推进简易工况法的过程中逐步收集检测数据,并重新确定地方的排放限值.     

粘胶纤维生产废水处理的工艺研究

处理粘胶纤维生产废水的工艺，采用分步逐段的技术方法，即酸，碱废水混曝气除硫化物加碱一步沉淀法除锌的处理技术以及用新型氧化混凝剂继续处理废水的有机物ＣＯＤｃｒ，出水ＣＯＤｃｒ为５０ｍｇ／Ｌ左右，ＣＯＤｃｒ平均去除率达８１．３７％，达到国家及地方排放标准。     

Microbial preference for different size classes of organic carbon: a study from Antarctic snow

Significance of carbon cycling in polar ecosystems is well recognized. Yet, bacteria in surface snow have received less attention in terms of their potential in carbon cycling. Here, we present results on carbon utilization by bacterial communities in three surface snow samples from Antarctica collected along a coastal to inland transect. Microcosm studies were conducted over 8 days at 5?±?1°C to study carbon metabolism in different combinations of added low molecular weight (LMW (glucose, <1 kDa)) and high molecular weight (HMW (starch, >1 kDa)) substrates (final 20 ppm). The total organic carbon (TOC) in the snow samples decreased with time at rates ranging from non-detectable to 1.4 ppm day(-1) with rates highest in snow samples from inland region. In addition, carbon utilization studies were also carried out with bacterial isolates LH1, LH2, and LH4 belonging to the genus Cellulosimicrobium, Bacillus, and Ralstonia, respectively, isolated from the snow samples. Studies with strain LH2 in different amendments of glucose and starch showed that TOC decreased with time in all amendments at a rate of 0.9-1.5 ppm day(-1) with highest rates of 1.4-1.5 ppm day(-1) in amendments containing a higher proportion of starch. The bacterial isolates were also studied to determine their ability to utilize other LMW and HMW compounds. They utilized diverse substrates like carbohydrates, amino acids, amines, amides, complex polymers, etc., of molecular mass <100 Da, 100-500 Da, >500 Da-1 kDa, and >1 kDa preferring (up to 31 times) substrates with mass of >1 kDa than <1 kDa. The ability of bacteria in snow to utilize diverse LMW and HMW substrates indicates that they could be important in the uptake of similar compounds in snow and therefore potentially govern snow chemistry.