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441.
Coffin-Lowry syndrome is a rare X-linked, semi-dominant mental retardation syndrome resulting from mutations of the ribosomal S6 kinase 2 (RSK2) gene. In the present report, a male patient affected with Coffin-Lowry syndrome is shown to have a nonsense mutation of the RSK2 gene. His unaffected mother does not have this mutation in her lymphocytes. In her third pregnancy prenatal diagnosis by mutation analysis has detected gonadal mosaicism. As this is the second report of germinal mosaicism in Coffin-Lowry syndrome, the finding has important implication for genetic counselling. Copyright © 2001 John Wiley & Sons, Ltd.  相似文献   
442.
Water quality levels and loads of nutrients transported by the Agüera stream (northern Spain) were studied for a year to assess the self-purification capacity of this system. The main villages produce an increase of nutrient concentrations and a degradation of water quality. Nevertheless, the high retention capacity, especially for phosphate, allows the stream to recover its previous levels of quality after a short reach. The retention of nutrients depends on a complex combination of the flow level, hydrologic stability and the development of periphytic communities.  相似文献   
443.
Distribution of Cu,Zn,Pb,Cr,Ni,Mn concentrations and the activity of polonium-210 in the surrounding area of a phosphate fertilizer industry located on the eastern coast of the Mediterranean Sea has been determined.Nineteen sampling sites were distributed around the industrial zone on a surface area of about 100,000 m2.Atomic absorption spectroscopy and Alpha spectroscopy were used to quantify the heavy elements and polonium-210,respectively.Investigation on a particle scale was conducted by TEM and SEM coupled to EDX and X-ray cartography to determine the nature of heavy elements carders and their distribution.Heavy elements were mainly concentrated inside the particle size fraction < 50μm.Their levels decreased with distance increasing from the industry.According to the reference soil,enrichment factors were about 10,15,32 and 100 times for Zn,Pb,Cu,and Cr,respectively inside the particle size fraction < 50 μm on the closest sites to the industry.The main contaminant sources were transport and storage of row materials and the free release of phosphogypsum waste.Heavy elements were entrapped inside agglomerates of sulfates,phosphates and iron oxihydroxides in a diffused shape.Polonium-210 with an enrichment factor of about 56,showed the same behavior of the spatial distribution of the trace elements.  相似文献   
444.
The main objective of this study was to statistically evaluate the significance of seasonal groundwater quality change and to provide an assessment on the spatial distribution of specific groundwater quality parameters. The studied area was the Mount Nif karstic aquifer system located in the southeast of the city of Izmir. Groundwater samples were collected at 57 sampling points in the rainy winter and dry summer seasons. Groundwater quality indicators of interest were electrical conductivity (EC), nitrate, chloride, sulfate, sodium, some heavy metals, and arsenic. Maps showing the spatial distributions and temporal changes of these parameters were created to further interpret spatial patterns and seasonal changes in groundwater quality. Furthermore, statistical tests were conducted to confirm whether the seasonal changes for each quality parameter were statistically significant. It was evident from the statistical tests that the seasonal changes in most groundwater quality parameters were statistically not significant. However, the increase in EC values and aluminum concentrations from winter to summer was found to be significant. Furthermore, a negative correlation between sampling elevation and groundwater quality was found. It was shown that with simple statistical testing, important conclusions can be drawn from limited monitoring data. It was concluded that less groundwater recharge in the dry period of the year does not always imply higher concentrations for all groundwater quality parameters because water circulation times, lithology, quality and extent of recharge, and land use patterns also play an important role on the alteration of groundwater quality.  相似文献   
445.
Environmental Science and Pollution Research - This study is focused on the analysis of regional variation of the chemical compositions of three Clinopodium menthifolium subsp. ascendens (Jord.)...  相似文献   
446.
Abstract

This paper presents the results and conclusions from experimental investigations concerning filtration properties of nonwovens. The needled nonwovens were made from polyester fibres (PTE) with average fibre diameter 12 µm and polypropylene fibres (PP) with average fibre diameter 32 μm. Nonwovens were produced out of each of those fibres or out of a mixture of polyester and polypropylene fibres. This paper also presents investigations of nonwoven fabric made of polypropylene fibres (PP) with average fibre diameter 2.6 μm, which was formed according to melt-blown technology. Oil mist, as challenge aerosol, was used to evaluate the performance of filter media at various aerosol velocities. The average oil mist test aerosol particle diameter was 0.3 μm. Filter penetration was measured at oil mist concentration 0.24 g/m3.  相似文献   
447.
To determine the effect of occupational stress on low-back pain (LBP), a cross-sectional study has been carried out, by interviews, on workers exposed to 3 stresses: manual handling (MH, 82 women and 264 men), whole body vibrations (WBV, 274 men), and static postures (278 women). Anthropometric data, occupational stress, LBP severity and frequency, and a psychological evaluation of these groups were compared to those of a control population of 208 workers (104 men and 104 women).

The results show that 30% of the population had never suffered from LBP. Age and the body mass index of the workers were the parameters most closely associated with LBP. Women involved in MH had higher frequency and severity of LBP than their reference population. Men involved in MH or exposed to WBV had higher frequency of painful episodes than their reference population. Workers exposed to one of the stresses were on sick leave for LBP more often, and for longer periods, than workers in the reference group. The results show that individual factors are often decisive in the onset of LBP. Nevertheless, in the more serious LBP cases, occupational stress is an aggravating factor for LBP and its consequences.  相似文献   
448.
The present study examines the natural radioactivity in some sedimentary rocks and their associated environmental impacts at Wadi Naseib area. Exposure rate (ER), dose rate (DR), radium equivalent activity (Ra(eq)), external hazard index (H(ex)), internal hazard index (H(in)) and radioactivity level index (I(gamma)) were calculated. Wadi Naseib area is covered with sedimentary rocks of early to late Paleozoic age. These rocks are classified into two types: mineralized and non-mineralized sediments. The radiometric investigations revealed that uranium and thorium contents reached up to 710 and 520 ppm, respectively, in the mineralized rocks. This was attributed to the presence of some secondary uranium minerals. All sediments had low values of eTh and K content. The exposure and dose rates exceeded public permissible values in the mineralized sediments. Exposure and dose rates were within the safety range for workers and the public in the non-mineralized sediments. The expected environmental impacts may be low due to the limited occurrence of U-mineralization and corresponding areas for radiation exposure. Some precautions and recommendations were suggested to avoid any possible environmental impacts from areas and/or raw materials of high intensity of natural radiation sources.  相似文献   
449.
Quantitative information on the adsorption/desorption of radionuclides by suspended loads is important in the study of their environmental behavior. In this paper, controlled laboratory experiments were directed at studying the kinetic transfer and final distribution of radiostrontium in aqueous suspensions using 85Sr as tracer. The results showed that the uptake of 85Sr in seawater can be properly described by one reversible-reaction model. However, in the absence of competitive cations, it has been shown that two reactions of different characteristic times are unambiguously involved in the kinetic evolution of adsorption. Thus, a modeling approach consisting of three-box model has been applied. The model predicts in a satisfactory way the time evolution of activities in the dissolved phase and two sites in the particles. Experimental evidence showed, through comparison among kinetic and distribution coefficients corresponding to different conditions, that Ca2+ affects strongly the rate and extent of Sr uptake by suspended particles. On the other hand, distribution coefficients were found to be sensitive to changes in suspended particulate matter (SPM) concentration, exhibiting a reverse effect with this parameter on the adsorption. In addition, desorption from particles is important showing that Sr can be easily released due to cation-exchange processes.  相似文献   
450.
Environmental Chemistry Letters - The outbreak of the human coronavirus disease 2019 (COVID-19) has induced an unprecedented increase in the use of several old and repurposed therapeutic...  相似文献   
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