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1.
In this study aimed to evaluate the pollution extent of metals and nonmetals inside and outside the ferrosilicon production factory in Edfu, Aswan, Egypt, raw materials (quartz, cokes, iron oxides), ferrosilicon alloy, silica fume, dust and suspended dust (at different sites) samples were collected from the factory, and fallen dust samples were collected from outside the factory, horizontally (at different sites and different distance and directions) and vertically (at different floors in the selected buildings). Gravimetric methods, X-ray fluorescence (XRF), flame photometer, wide range carbon determinator and atomic absorption spectroscopy tools were used for elements determination. The results indicating that the fallen dust and its element contents on southern factory walls being higher than those on eastern factory walls may be due to the nature of the dusts and effects of wind force and wind direction. Fallen dust levels in different regions outside the factory were found to be affected by the distance, direction and floors. The nature of dust samples was affected by gravity and the suspended dust in different factory units depended on the work capacity and method of handling materials by personnel in different production units. Silica fume was a complicated problem, had dangerous effect against the workers' health, and was characterized by high concentrations of SiO2(90.6%～93.6%) and heavy metals (Mn, 420.6×10-6～520.3×10-6; Fe, 2354×10-6～2685×10-6; Co, 80.7×10-6～101.6×10 6 and Ni,5.3× 10-6～6.05× 10-6). The TSP (Total Suspended Particulate) levels in all factory units were higher than the recommended air quality value (70 μg/m3) under Egyptian law. The effect of ferrosilicon factory fallen dust on the surrounding regions decreased with increasing distance between the factory and these regions. The suspended dust samples in the factory units and their components greatly exceeded national and international standards, so health and environmental criteria must be enforced on these units.  相似文献   

2.
INTRODUCTION Nitrogen oxide (NOx) is one of the main air pol- lutants found in the flue gases from chemical and power plants belching acid rain and photochemical smog. Over 90 percent of all man-made nitrogen ox- ides that enter our atmosphere are produced by the combustion of various fuels. Compared with the ad- vanced stage of SO2 gas removal technologies devel- opment, the removal of NOx gases is still in the initial stages of development as roughly 90 to 95 percent of NOx emitted i…  相似文献   

3.
1　Introduction　Ahugeamountofliteratureexistsonthestudyofi dentifyingtracemetalionsbymeansofspectropho tometry[1 3] ,fluorimetry[4 6 ] aswellas polarogra phy[7 9] ,whichhaveactiononlocatingtheendpointoftheindicatingreaction .Howeverbothspectropho tometryandfluorimetryareeasytobeinterferedbycolororprecipitation ,whilepolarographyhasanissueofmercurypollution .Thecatalyzingkineticanalysishasthecharacteristicsofhighsensitivityandspeedi ness.Oscillographicpotentiometryisasimpleintu itionisticanal…  相似文献   

4.
1, 10-Phenanthroline (phen) was tested as a complexing agent for on-line preconcentration of iron on RP-C18 material in a microcolumn with flow injection coupled with flame atomic absorption spectrometer (FI-FAAS). The on-line formed Fe(II)-phen complexes were adsorbed on the C18 sorbent material. Various parameters affecting the on-line Fe(II)-phen complex formation and its subsequent adsorption in the microcolumn as well as its elution into the nebulizer of AAS were optimized. A 2.5×10−3 mol/L phen in 2% through the microcolumn for 30 s. The adsorbed Fe(II)-phen complexes in the microcolumn were eluted with ethanol in 10 s into the nebulizer of AAS. Ascorbic acid (5×10−4 mol/L) was added to the sample solution for the reduction of Fe(III) to Fe(II). A good precision (RSD=1.1%,n=10), high enrichment factor (19) and sample throughput (90 h−1) with detection limit (3σ) of 3 μg/L were obtained. The method was applied on standard reference materials (i. e. mussel and tomato leaves,) for iron determination and yielded results agreeing well with certified values. Project supported by the Zhejiang Provincial Natural Science Foundation of China and Zhejiang Environmental Protection Foundation From Pakistan Institute of Nuclear Science & Technology, Islamabad, Pakistan and now ZJ University, Ph. D. student.  相似文献   

5.
INTRODUCTION Over the recent decades extensive research on atmospheric particles in urban environments was carried out. Most of the following papers refer to their authors’ contribution to air pollution and the effects on human health (Dzubay and Mamane, 1989; van Borm et al., 1989; 1990; Rojas et al., 1990; Paoletti et al., 1991; 1999; Al-Rajhi et al., 1996; McMurry et al., 1996; Querol et al., 1996; BéruBé et al., 1997; Esteve et al., 1997; Harrison et al., 1997; Zou and Hooper…  相似文献   

6.
INTRODUCTION With the development of modern electronics,there is a growing trend of designing a low-voltagehigh precision current reference in many mixed-signaland analog circuits such as data converters (Mehr andSinger, 2000; Oh et al., 2004), oscillators and PLLs(Razavi, 2001; Banba and Shiga, 1999). Low-costreasons need the reference to be realized in simplestandard CMOS logic process technology, withoutresorting to the use of BiCMOS process and specialdevices such as floating-g…  相似文献   

7.
Osteochondral allografting has been proved to be a useful method to treat diseased or damaged areas of joint surfaces. Operational long-term stocks of grafts which supply a buffer between procurement and utilization would contribute to the commercialization or industrialization of this technology. Vitrification has been thought to be a promising method for successful preservation of articular cartilage (AC), but high concentration cryoprotectants (CPAs) are used which may cause high cellular toxicity. An effective way to reduce CPA toxicity is to increase CPA concentration gradually while the temperature is lowered. Understanding the mechanism of CPA permeation at subzero temperatures is important for designing the cryopreservation protocol. In this research, the permeation of dimethyl sulfoxide (Me2SO) in ovine AC at subzero temperatures was studied experimentally. Pretreated AC discs were exposed in Me2SO solutions for different time (0, 5, 15, 30, 50, 80, and 120 min) at three temperature levels (−10, −20, and −30 °C). The Me2SO concentration within the tissue was determined by ultraviolet (UV) spectrophotometry. The diffusion coefficients were estimated to be 0.85×10−6, 0.48×10−6, and 0.27×10−6 cm2/s at −10, −20, and −30 °C, respectively, and the corresponding activation energy was 29.23 kJ/mol. Numerical simulation was performed to compare two Me2SO addition protocols, and the results demonstrated that the total loading duration could be effectively reduced with the knowledge of permeation kinetics.  相似文献   

8.
INTRODUCTION Chlorinated hydrocarbons, a class of widely used dry-cleaning liquids, industrial organic solvents, and degreasers, increasingly find their way into drinking water sources, thus posing a very serious health and environmental problem (Love and Eliers, 1982). These organic solvents are known for their stability in the environment and cancer-causing po- tency and cannot be effectively and economically eliminated by current conventional treatment tech- nologies. One of the few av…  相似文献   

9.
Objective: To observe the effect of Yangxueqingnao particles on rat vascular smooth muscle cell (VSMC) proliferation induced by lysophosphatidic acid (LPA). Methods: The amount of3H-TdR (3H-thymidine) admixed in cultured rat VSMC was measured and mitogen-activated protein kinase (MAPK) activity and lipid peroxidation end product malondialdehyde (MDA) content of the VSMC were assayed. Results: 1×10−9, 1×10−8, 1×10−7 mol/L LPA in a concentration dependent manner, induced the amount of3H-TdR admixed, MAP kinase activity, and MDA content of the cultured rat VSMC to increase. However, 5%, 10%, and 15% Yangxueqingnao serum preincubation resulted in a decrease of 23.0%, 42.0%, and 52.0% (P<0.01) respectively in the amount of3H-TdR admixed, a decline in VSMC MAP kinase activity of 13.9% (P<0.05), 29.6% (P<0.01), and 48.9% (P<0.01) respectively, and also, a decrease in MDA content of VSMC of 19.4%, 24.7%, and 43.2% (P<0.01) respectively, in the 1×10−7 mol/L LPA-treated VSMC. Conclusions: LPA activates the proliferation and lipid peroxidation of VSMC in a concentration dependent manner. The LPA-induced VSMC proliferation is related to the activity of MAP kinases, enzymes involved in an intracellular signalling pathway. The results of the present study showed that Yangxueqingnao particles can effectively inhibit LPA-induced VSMC proliferation, MAP kinase activation, and reduce lipid peroxidative lesion. Project (No. 491010-W50339) supported by Chinese Traditional Medicine Administration Bureau of Zhejiang Province, China  相似文献   

10.
Bread wheat varieties as influenced by different nitrogen levels   总被引：4，自引：2，他引：2  
INTRODUCTION Dera Ismail Khan lies in Pakistan’s arid zone (71.07° longitude, 31.57° latitude and 500 m above sea level). This zone is in the extreme south of (NWFP) Pakistan at the bank of the River Indus. Dera Ismail Khan is bounded by Sulaiman Range to the West, the Indus River on the East, Marwat and Bhit- tani Ranges on the North and Vehowa Nala (Punjab) on the South. Besides certain local variability the area is comprised of four basic divisions viz mountains, a series …  相似文献   

11.
INTRODUCTION On-road vehicles are responsible for a signifi-cant and rapidly increasing portion of the air pollution in the urban areas of China due to rapid growth of motor vehicle population. The State Environmental Protection Administration (SEPA) of China has identified motor vehicles emissions as the major source of urban air pollution in China (SEPA, 2004). As of 2004, on-road vehicles were estimated to con-tribute over 50% of the nitrogen oxides (NOx) to large city’s emissi…  相似文献   

12.
1　Ｉｎｔｒｏｄｕｃｔｉｏｎ　Ｔｈｅｆｕｎｄａｍｅｎｔａｌｐｈｙｓｉｃａｌｍｅｔａｌｌｕｒｇｙｏｆｔｈｅｒｍｏｍｅｃｈａｎｉｃａｌｐｒｏｃｅｓｓｉｎｇ(ＴＭＰ)ｈａｓｂｅｃｏｍｅｍｕｃｈｂｅｔｔｅｒｕｎｄｅｒｓｔｏｏｄｏｖｅｒｔｈｅｌａｓｔｔｗｏｄｅｃａｄｅｓ[1～8].ＩｔｉｓｗｅｌｌｃｏｍｍｏｎｌｙｒｅｃｏｇｎｉｚｅｄｔｈａｔｔｈｅｍｉｎｕｔｅａｄｄｉｔｉｏｎｏｆｓｔｒｏｎｇｃａｒｂｏｎｉｔｒｉｄｅｏｒｎｉｔｒｉｄｅｆｏｒｍｉｎｇｅｌｅｍｅｎｔｓｓｕｃｈａｓＮｂ,ＴｉａｎｄＶｔａｋｅｓｖｅｒｙｉｍｐ…  相似文献   

13.
This study presents a rapid, specific and sensitive liquid chromatography/tandem mass spectrometry (LC-MS/MS) assay for determination of risperidone (RIS) in human serum using paroxetine as an internal standard (IS). An Alltima-C 18separation. The analysis was performed by selected reaction monitoring (SRM) method, and the peak area of the m/z 411.3→ 191.1 transition for RIS was measured versus that of the m/z 330.1→192.1 transition for IS to generate the standard curves. The assay linearity of RIS was confirmed over the range 0.25～50.00 ng/ml and the limit of quantitation was 0.05 ng/ml. The linear range corresponds well with the serum concentrations of the analytes obtained in clinical pharmacokinetic studies. Intraday and interday relative standard deviations were 1.85%～9.09% and 1.56%～4.38%, respectively. The recovery of RIS from serum was in the range of 70.20%～84.50%. The method was successfully applied to investigate the bioequivalence between two kinds of tablets (test versus reference products) in 18 healthy male Chinese volunteers. The result suggests that two formulations are bioequivalent.  相似文献   

14.
We report an important observation that the surface conductivity of antibody layer immobilized on polylysine-coated glass substrate decreases upon the formation of complex with their specific antigens. This change in conductivity has been observed for both monoclonal and polyclonal antibodies. The conductance of monoclonal mouse IgG immobilized on polylysine-coated glass substrate changed from 1.02×10−8 Ω−1 to 1.41×10−11 Ω−1 at 10 V when complex is formed due to the specific biomolecular interactions with rabbit anti-mouse IgG F(ab′)2. Similar behavior was observed when the same set up was tested in two clinical assays: (1) anti-Leishmania antigen polyclonal antibodies taken from Kala Azar positive patient serum interacting with Leishmania promastigote antigen, and (2) anti-p21 polyclonal antibodies interacting with p21 antigen. The proposed concept can represent a new immunodiagnostic technique and may have wide ranging applications in biosensors and nanobiotechnology too.  相似文献   

15.
Field experiments were conducted at Cereal Crops Research Institute, Pirsabak, Nowshera, Pakistan, during winter 2003~2004 and 2004~2005 to evaluate the effect of nitrogen and sulfur levels and methods of nitrogen application on canola (Brassica napus L. cv. Bulbul-98) under rainfed conditions. Four levels of S (0, 10, 20, and 30 kg/ha) and three levels of N (40, 60, and 80 kg/ha) and a control treatment with both nutrients at zero level were included in the experiments. Sulfur levels were applied at sowing while N levels were applied by three methods (100% soil application, 90% soil 10% foliar application, and 80% soil 20% foliar application). The experiments were laid out in randomized complete block (RCB) design having four replications. Oil content increased significantly up to 20 kg S/ha but further increase in S level did not enhance oil content. Glucosinolate content increased from 13.6 to 24.6 μmol/g as S rate was increased from 0 to 30 kg/ha. Protein content increased from 22.4% to 23.2% as S rate was increased from 0 to 20 kg/ha. Oil content responded negatively to the increasing N levels. The highest N level resulted in the highest values for protein (23.5%) and glucosinolate (19.9 μmol/g) contents. Methods of N application had no significant impact on any parameters under study.  相似文献   

16.
Well-cubic perovskite lanthanum aluminate (LaAlO3) film on (110) silicon substrate was fabricated by sol-gel method with corresponding inorganic salts. Lanthanum acetate and aluminum acetate glacial acetic acid solutions were prepared via ligand exchange starting from lanthanum nitrate hexahydrate and aluminum nitrate hexahydrate after being refluxed. (CH3CO)2O removed nitrates and the crystallized H2O completely, acetylacetone (AcAc) was partially bidentated with metallic ion of the metallic acetates and formed La(OAc)3−x (AcAc) x which were hydrolyzed into La(AcAc)3−x(OH) x by adding 10 ml 0.4% methyl cellulose (MCL) solution. The La(AcAc)3−x (OH) x , polymerizing and combining with MCL, formed the LaAlO3 sol precursor with heteropolymeric structure and formed film easily. The epitaxial LaAlO3 film on Si(110) substrate was crystallized after being annealed in thermal annealing furnace for 650–750 °C/30 min. The morphologies and microstructures were characterized. The refractive index of the LAO film was 1.942 to 2.007; the dielectric constant and the dissipation factors were estimated to be 23–26 and 2.1×10−4−2.4×10−4 respectively. Project (No. 2002CB613305) supported by the National Basic Research Program (973) of China  相似文献   

17.
INTRODUCTION Motor vehicles continue to be the dominant source of air pollution, despite tremendous advances in engine technology and pollution control. Vehicles are significant sources of CO, HC, and PM and comprise one of the most important sources of NOx, which along with HC, are the essential precursors of ground-level ozone. In view of emissions harm to human health, major efforts to control them have been made, both through improved emission control technologies and through gasol…  相似文献   

18.
Development and evaluation of immunoassay for zeranol in bovine urine   总被引：1，自引：0，他引：1  
A high affinity polyclonal antibody-based enzyme linked immunosorbent assay （ELISA） was developed for the quantification of zeranol in bovine urine. On the basis of urine matrix studies, the optimized dilution factors producing insignificant matrix interference were selected as 1：5 in pretreatment. In the improved ELISA, the linear response range was between 0.02 and 1 μg/ml, and the detection limit was 0.02 μg/ml for the assay. The overall recoveries and the coefficients of variation （CVs） were in the range of 82%-127% and 3.5%-8.8%, respectively. Thirty-six bovine urine samples spiked with zeranol （ranging from 0.2 to 10 μg/ml） were detected by the ELISA and liquid chromatography （LC） method, and good correlations were obtained between the two methods （R^2=0.9643）. We conclude that this improved ELISA is suitable tool for a mass zeranol screening and can be an altemative for the conventional LC method for zeranol in bovine urine.  相似文献   

19.
Objective  This study is to determine the effect of the natural product parthenolide, a sesquiterpene lactone isolated from extracts of the herb Tanacetum parthenium, on the proliferation of vascular smooth muscle cells (VSMCs). Methods  Rat aortic VSMCs were isolated and cultured in vitro, and treated with different concentrations of parthenolide (10, 20 and 30 μmol/L). [3H]thymidine incorporation was used as an index of cell proliferation. Cell cycle progression and distribution were determined by flow cytometric analysis. Furthermore, the expression of several regulatory proteins relevant to VSMC proliferation including IκBα, cyclooxygenase-2 (Cox-2), p21, and p27 was examined to investigate the potential molecular mechanism. Results  Treatment with parthenolide significantly decreased the [3H]thymidine incorporation into DNA by 30%∼56% relative to control values in a dose-dependent manner (P<0.05). Addition of parthenolide also increased cell population at G0/G1 phase by 19.2%∼65.7% (P<0.05) and decreased cell population at S phase by 50.7%∼84.8% (P<0.05), which is consistent with its stimulatory effects on p21 and p27. In addition, parthenolide also increased IκBα expression and reduced Cox-2 expression in a time-dependent manner. Conclusion  Our results show that parthenolide significantly inhibits the VSMC proliferation by inducing G0/G1 cell cycle arrest. IκBα and Cox-2 are likely involved in such inhibitory effect of parthenolide on VSMC proliferation. These findings warrant further investigation on potential therapeutic implications of parthenolide on VSMC proliferation in vivo. Project (No. 491020-W50315) supported by the Foundation of the Health Bureau of Zhejiang, China  相似文献   

20.
In order to comply with the requirements for a drug listed in China, the study was developed to compare the pharmacokinetics and relative bioavailability of two different enteric formulations of omeprazole (OPZ) in healthy Chinese subjects. A total of 32 volunteers participated in the study. Plasma concentrations were analyzed by nonstereospecific liquid chromatography/tandem mass spectrometric (LC-MS/MS) method. After administration of a single 40-mg dose of the two OPZ formulations, the comparative bioavailability was assessed by calculating individual AUC0−t (the area under the concentration-time curve from time zero to the last measurable concentration), AUC0−∞ (the area under the concentration-time curve extrapolated to infinity), C max (the maximum observed concentration), and T peak (the time to C max) values of OPZ, 5-hydroxyomeprazole (OH-OPZ), and omeprazole sulfone (OPZ-SFN), respectively. The 90% confidence intervals (CIs) of AUC0−t , AUC0−∞, and C max were 85.4%–99.0%/88.8%–98.6%/87.6%–99.4%, 85.5%–99.2%/89.0%–98.6%/88.5%–101.3%, and 72.3%–87.6%/79.6%–91.1%/88.4%–99.1% for OPZ/OH-OPZ/OPZ-SFN, respectively, and T peak values did not differ significantly. In this study, the test formulation of OPZ in fasting healthy Chinese male volunteers met the Chinese bioequivalance standard to the reference formulation based on AUC, C max, and T peak.  相似文献   

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