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Robert Wallerstein Sonya Misra R. Bryce Dugar Monika Alem Ronit Mazzoni Matthew J. Garabedian 《黑龙江环境通报》2015,35(9):841-847
Genetic counseling for prenatal diagnosis of autosomal trisomy is complex because of the uncertainty of outcome, which is important for management decisions. Compilation of cases of prenatally diagnosed autosomal trisomies in amniocytes has been done previously in an attempt to elucidate the clinical phenotype of these pregnancies. It has been greater than a decade since these studies were completed. To update this work, we reviewed cases reported in the literature since that time. These cases are correlated with the prior reports to increase knowledge about outcomes and to hopefully improve the data available for genetic counseling. The risk of abnormal outcome can be summarized as: very high risk (>60%) for 47,+2/46; 47,+9/46; 47,+16/46; 47,+20/46; and 47,+22/46; high risk (40–59%) for 47,+5/46; 47,+14/46; and 47,+15/46; moderately high risk (20–39%) for 47,+7/46 47,+12/46; and 47,+17/46; moderate risk (up to 19%) for 47,+6/46 and 47,+8/46, and none were low risk. 47,+6/46 was originally indeterminate, 47,+7/46 was originally moderate risk, 47,+9/46 was originally high risk, and 47,+17/46 was originally low risk. © 2015 John Wiley & Sons, Ltd. 相似文献
13.
Ashok K. Alva 《Environmental management》1992,16(6):769-776
Extremely sandy soils and poorly distributed high annual rainfall in the state of Florida contribute to significant leaching
losses of nutrients from routine fertilization practices. A leaching column experiment was conducted to evaluate the leaching
losses of nutrients when using currently available N, P, K blend fertilizers for young citrus tree fertilization. Fertilizer
blends included NH4NO3, Ca(NO3)2, IBDU, IBDU plus Escote, Nutralene, Osmocote, and Meister. Following leaching of 1000 ml of water through soil columns, which
simulates leaching conditions with 26 cm of rainfall, the amount of NO3 and NH4 recovered in the leachate from soil columns amended with an NH4NO3 blend accounted for 37% and 88% of the respective nutrients contained in the quantity of blend per column. The corresponding
values for soil columns amended with a Ca(NO3)2 blend were 48% and 100%. Leraching losses of both NO3 (<3%) and NH4 (<4%) were drastically decreased when using controlled-release fertilizers. The recoveries of P and K in 1000 ml of leachate
were 1.3% and 8%, respectively, of the nutrients added as Osmocote, which contained coated P and K sources. In the case of
the rest of fertilizer blends, the recoveries of P and K in 1000 ml of leachate were as high as 52%–100% and 28%–100%, respectively.
Therefore, controlled-release technology offers an important capability for minimizing leaching losses of nutrients. 相似文献
14.
Geeta?Mehta Amar?K.?Mohanty Kelby?Thayer Manjusri?Misra Lawrence?T.?DrzalEmail author 《Journal of Polymers and the Environment》2005,13(2):169-175
Biocomposites were made by a novel high volume processing technique named biocomposite sheet molding compound panel (BCSMCP) manufacturing process. This process design was inspired by the commercial glass fiber–polyester resin composite fabrication method called sheet molding compounding (SMC). This process yields continuous production of biocomposites on a large scale, and thus can be easily adopted in industries. A unique fiber dispersion method, which enabled uniform distribution of natural fibers, was used in this process. Consistency of the process was tested by evaluating the repeatability of the resultant materials mechanical properties. The low cost biocomposites produced as a result of the processing will be used for various panel applications such as housing and transportation. The molded samples were tested for various mechanical and thermal properties, in accordance with ASTM procedures. The biocomposites were made with various natural fibers including, big blue stem grass, jute, and industrial hemp. By combining different natural fibers in varying mass fractions, hybrid biocomposites were made using this process. Grass fiber reinforced polyester biocomposites processed by the SMC line showed very promising results. 相似文献
15.
Sustainable Cellular Biocomposites from Natural Fibers and Unsaturated Polyester Resin for Housing Panel Applications 总被引:1,自引:0,他引:1
Rigoberto?Burgue?oEmail author Mario?J.?Quagliata Geeta?Misra?Mehta Amar?K.?Mohanty Manjusri?Misra Lawrence?T.?Drzal 《Journal of Polymers and the Environment》2005,13(2):139-149
Increased environmental awareness and interest in long-term sustainability of material resources has motivated considerable advancements in composite materials made from natural fibers and resins, or biocomposites. In spite of these developments the lower stiffness and strength of biocomposites has limited their applications to non-load-bearing components. This paper presents an overview of a study aimed at showing that the shortcomings of biocomposites can be overcome through hybrid material designs and efficient structural configurations to make them suitable for load bearing structural components. Hybrid blends of natural and synthetic fibers can significantly improve the characteristics of biocomposites with minimal cost and environmental impact, and hierarchical cellular designs can maximize material efficiency in structural components. Periodic and hierarchical cellular plate designs made from natural fibers and unsaturated polyester resin were evaluated experimentally and analytically. Stiffness, strength, and dimensional stability of all-biocomposite and hybrid natural–synthetic material systems were evaluated through material tests while structural performance of cellular plate designs was assessed through flexural tests on laboratory-scale samples. The experimental results were correlated with analytical models for short-fiber composites and cellular structures. The results showed that biocomposites have adequate short-term performance and that they can efficiently compete with housing panels made from conventional structural materials. 相似文献
16.
17.
Ashok Khosla 《生态毒理学报》2003,25(2):15-18
法人社会责任概念的发展,已经超出了简单的慈善事业和遵从法律的范畴,而包括了对优秀法人公民的经商和行为举止更广泛的伦理解释 .这种演变的下一个阶段,可能要由扩大市场盈利商业活动来推动,这一点过去被大大忽视了 .只要提供的商品和服务能够满足贫苦人群的基本需求--同时也提高了当地经济的购买力--就可以既获得利润,又尽到了社会责任 . 相似文献
18.
Misra C Geller MD Shah P Sioutas C Solomon PA 《Journal of the Air & Waste Management Association (1995)》2001,51(9):1309-1317
In this paper, we describe the development and laboratory and field evaluation of a continuous coarse (2.5-10 microm) particle mass (PM) monitor that can provide reliable measurements of the coarse mass (CM) concentrations in time intervals as short as 5-10 min. The operating principle of the monitor is based on enriching CM concentrations by a factor of approximately 25 by means of a 2.5-microm cut point round nozzle virtual impactor while maintaining fine mass (FM)--that is, the mass of PM2.5 at ambient concentrations. The aerosol mixture is subsequently drawn through a standard tapered element oscillating microbalance (TEOM), the response of which is dominated by the contributions of the CM, due to concentration enrichment. Findings from the field study ascertain that a TEOM coupled with a PM10 inlet followed by a 2.5-microm cut point round nozzle virtual impactor can be used successfully for continuous CM concentration measurements. The average concentration-enriched CM concentrations measured by the TEOM were 26-27 times higher than those measured by the time-integrated PM10 samplers [the micro-orifice uniform deposit impactor (MOUDI) and the Partisol] and were highly correlated. CM concentrations measured by the concentration-enriched TEOM were independent of the ambient FM-to-CM concentration ratio, due to the decrease in ambient coarse particle mass median diameter with an increasing FM-to-CM concentration ratio. Finally, our results illustrate one of the main problems associated with the use of real impactors to sample particles at relative humidity (RH) values less than 40%. While PM10 concentrations obtained by means of the MOUDI and Partisol were in excellent agreement, CM concentrations measured by the MOUDI were low by 20%, and FM concentrations were high by a factor of 5, together suggesting particle bounce at low RH. 相似文献
19.
L T Chang H H Suh J M Wolfson K Misra G A Allen P J Catalano P Koutrakis 《Journal of the Air & Waste Management Association (1995)》2001,51(10):1414-1422
While researchers have linked acute (less than 12-hr) ambient O3, PM2.5, and CO concentrations to a variety of adverse health effects, few studies have characterized short-term exposures to these air pollutants, in part due to the lack of sensitive, accurate, and precise sampling technologies. In this paper, we present results from the laboratory and field evaluation of several new (or modified) samplers used in the "roll-around" system (RAS), which was developed to measure 1-hr O3, PM2.5, and CO exposures simultaneously. All the field evaluation data were collected during two sampling seasons: the summer of 1998 and the winter of 1999. To measure 1-hr O3 exposures, a new active O3 sampler was developed that uses two nitrite-coated filters to measure O3 concentrations. Laboratory chamber tests found that the active O3 sampler performed extremely well, with a collection efficiency of 0.96 that did not vary with temperature or relative humidity (RH). In field collocation comparisons with a reference UV photometric monitor, the active O3 sampler had an effective collection efficiency ranging between 0.92 and 0.96 and a precision for 1-hr measurements ranging between 4 and 6 parts per billion (ppb). The limits of detection (LOD) of this method were 9 ppb-hr for the chamber tests and approximtely 16 ppb-hr for the field comparison tests. PM2.5 and CO concentrations were measured using modified continuous monitors--the DustTrak and the Langan, respectively. A size-selective inlet and a Nafion dryer were placed upstream of the DustTrak inlet to remove particles with aerodynamic diameters greater than 2.5 microm and to dry particles prior to the measurements, respectively. During the field validation tests, the DustTrak consistently reported higher PM2.5 concentrations than those obtained by the collocated 12-hr PM2.5 PEM samples, by approximately a factor of 2. After the DustTrak response was corrected (correction factor of 2.07 in the summer and 2.02 in the winter), measurements obtained using these methods agreed well with R2 values of 0.87 in the summer and 0.81 in the winter. The results showed that the DustTrak can be used along with integrated measurements to measure the temporal and spatial variation in PM2.5 exposures. Finally, during the field validation tests, CO concentrations measured using the Langan were strongly correlated with those obtained using the reference method when the CO levels were above the LOD of the instrument [approximately 1 part per million (ppm)]. 相似文献
20.
The fluorescence spectroscopic behavior of bromadiolone (anticoagulant rodenticide), a substituted 4-hydroxycoumarin derivative, was investigated in water and in organized media like micelles and cyclodextrins. A detailed study on various photophysical parameters like fluorescence intensity (IF), quantum yield (), lifetime (τ) and steady state fluorescence anisotropy (r) of bromadiolone in aqueous and in organized media was carried out. Bromadiolone in aqueous solution was observed to be in an aggregated state, thereby showing weak emission due to self-quenching. Marked enhancement of fluorescence intensity was observed in organized media like micelles and β-cyclodextrin. A preliminary investigation has been done to find out whether this enhancement of fluorescence can be used to develop a sensitive analytical method for determination of bromadialone in aqueous media. A linear relationship between the fluorescence intensity and concentration of bromadiolone was observed in the range of 0.15–7.9 μg ml−1 in cetyltrimethylammonium bromide (CTAB) and 0.5–26.4 μg ml−1 in β-cyclodextrin medium. The lower detection limit was found to be 37 ng ml−1 in presence of CTAB and 23 ng ml−1 in β-cyclodextrin. Comparison with 4-hydroxycoumarin, an unsubstituted analogue, was made. 相似文献