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21.
Trace element and Sigma DDT concentrations in horticultural soils from the Tasman, Waikato and Auckland regions of New Zealand 总被引:1,自引:0,他引:1
Gaw SK Wilkins AL Kim ND Palmer GT Robinson P 《The Science of the total environment》2006,355(1-3):31-47
The long-term routine use of agrichemicals can result in elevated levels of trace elements and persistent organic pollutants in soils. Trace element concentrations and SigmaDDT levels were measured in soil (0-7.5 cm) samples collected from horticultural and grazing properties in 3 regions of New Zealand (Auckland, Tasman and Waikato). Elevated levels of arsenic (<2 to 58 mg kg(-1)), cadmium (<0.1 to 1.5 mg kg(-1)), copper (5 to 523 mg kg(-1)), lead (5 to 243 mg kg(-1)) and SigmaDDT (<0.03 to 34.5 mg kg(-1)) were detected in soils from all 3 regions. With the exception of cadmium and zinc, significantly higher levels of contaminants were generally detected in horticultural soils than in grazing soils. Our results have implications for the on-going use of agrichemicals as concentrations of cadmium, copper, tin and zinc in some samples exceeded ecotoxicity based soil criteria. The p,p'-DDE:DDT ratios indicate that the degradation of DDT in NZ horticultural soils may be inhibited by the co-contamination with trace elements. 相似文献
22.
Industry case studies in the use of immersive virtual assembly 总被引:1,自引:0,他引:1
Sankar Jayaram Uma Jayaram Young Jun Kim Charles DeChenne Kevin W. Lyons Craig Palmer Tatsuki Mitsui 《Virtual Reality》2007,11(4):217-228
In this paper, we report on two engineering case studies that have been conducted as part of a Virtual Assembly Technology
Consortium. The objectives of the case studies were to determine if immersive virtual assembly capabilities allow industry
assembly situations to be modelled and studied realistically, and to demonstrate the downstream value of the virtual assembly
capabilities in areas such as ergonomics, assembly installation, process planning, installation, and serviceability. What
is of special significance is that instead of modelling simplified problems or perceived representative situations, the case
studies were constructed from actual assembly floor projects and situations encountered at industry member sites and with
considerable participation from industry engineers and manufacturing shop floor personnel. Based on the success of the case
studies, the consortium members inferred that virtual assembly methods are poised to move out of the realm of special projects
and test scenarios to deployment in the actual design and manufacturing cycle. However, in order to be truly accepted in industry,
there are still issues to be addressed in terms of ease of use, portability of the applications, and preparation of the models
for the evaluations. Thus, the case studies added a new dimension to the exploration and understanding of how this new technology
could be of practical value in industry. 相似文献
23.
We have measured the concentration and isotopic composition of lead in blood over a 15-month period for a subject who undertook recreational shooting in outdoor and indoor firing ranges on an irregular basis. We have also measured the isotopic composition in cast lead, Cu-jacketed and Teflon-coated bullets, propellant and primer from which he assembled the cartridges. Blood lead concentration increased from 3.2 to 6.7 microg/dl with use of dominantly cast lead bullets in the outdoor range. In two intervals when no firing was undertaken for 3-4 months, the blood lead concentrations either decreased towards a baseline value in the case where only Cu-jacketed bullets were fired or remained elevated when dominantly cast lead bullets were fired. The propellants contained <2 ppm Pb and contribute negligibly to blood lead. The isotopic composition of the primer used for all bullets was consistent with a source from the US. The bullets were of different materials and made in Australia and the US, with lead from sources of different geological age and hence different isotopic signatures. Variations in blood lead concentration and isotopic composition appear most strongly influenced by the bullets. Although more expensive, the use of Cu-jacketed bullets, non-lead primers and well-ventilated indoor firing ranges would lessen the health impacts of recreational shooting. 相似文献
24.
Palmer RE Sloan PA Xirouchaki C 《Philosophical transactions. Series A, Mathematical, physical, and engineering sciences》2004,362(1819):1195-1205
The deposition onto surfaces of clusters of atoms, prepared and size-selected in the gas phase, is, like atomic or molecular manipulation with the scanning tunnelling microscope, an appealing (but parallel) route to the creation of nanoscale surface features. Both of these seemingly orthogonal approaches allow, in principle, a selected number of atoms to be organized, and both are strongly affected by the lateral thermal diffusion of the constituent atoms, molecules or clusters over the surface. In this sense, the room-temperature (as opposed to cryogenic-temperature) regime can be regarded as a hostile environment for organizing atoms. In this paper we review recent achievements in size-selected cluster deposition and molecular manipulation at room temperature and thus address the fundamental question: with what precision can we organize atoms at room temperature? 相似文献
25.
Palmer PJ 《Journal of hazardous materials》2004,115(1-3):181-192
Process hazard analysis (PHA) is widely used across a spectrum of industries and facilities, but there are few metrics for the evaluation and assessment of PHAs. Most existing protocols address PHA solely in terms of regulatory compliance, but do not address the completeness or depth of the assessment, as most PHAs have been performed on a "performance basis" under the relevant regulations. It is possible to objectively assess PHAs, in order to determine adequacy of completion and degree of review, using both audit protocol and scoring approaches. Audit protocol approaches offer simplicity and ease of use, and when combined with specific scoring for adequacy allow for informed decisions about remedial action with respect to the PHA. 相似文献
26.
NS Shachter T Ebara R Ramakrishnan G Steiner JL Breslow HN Ginsberg JD Smith 《Canadian Metallurgical Quarterly》1996,98(3):846-855
We have generated transgenic mice over-expressing human apolipoprotein CI (apo CI) using the native gene joined to the downstream 154-bp liver-specific enhancer that we defined for apo E. Human apo CI (HuCI)-transgenic mice showed elevation of plasma triglycerides (mg/dl) compared to controls in both the fasted (211 +/- 81 vs 123 +/- 52, P = 0.0001) and fed (265 +/- 105 vs 146 +/- 68, P < 0.0001) states. Unlike the human apo CII (HuCII)- and apo CIII (HuCIII)-transgenic mouse models of hypertriglyceridemia, plasma cholesterol was disproportionately elevated (95 +/- 23 vs 73 +/- 23, P = 0.002, fasted and 90 +/- 24 vs 61 +/- 14, P < 0.0001, fed). Lipoprotein fractionation showed increased VLDL and IDL + LDL with an increased cholesterol/triglyceride ratio (0.114 vs 0.065, P = 0.02, in VLDL). The VLDL apo E/apo B ratio was decreased 3.4-fold (P = 0.05) and apo CII and apo CIII decreased in proportion to apo E. Triglyceride and apo B production rates were normal, but clearance rates of VLDL triglycerides and postlipolysis lipoprotein "remnants" were significantly slowed. Plasma apo B was significantly elevated. Unlike HuCII- and HuCIII-transgenic mice, VLDL from HuCI transgenic mice bound heparin-Sepharose, a model for cell-surface glycosaminoglycans, normally. In summary, apo CI overexpression is associated with decreased particulate uptake of apo B-containing lipoproteins, leading to increased levels of several potentially atherogenic species, including cholesterol-enriched VLDL, IDL, and LDL. 相似文献
27.
JL Lerat A Mandrino JL Besse B Moyen E Brunet-Guedj 《Canadian Metallurgical Quarterly》1997,83(7):591-601
PURPOSE OF THE STUDY: The purpose of this study was to compare the functional results obtained when an external extra-articular plasty was added to an anterior cruciate ligament (ACL) reconstruction using an autologous bone tendon-bone patellar tendon graft. MATERIAL AND METHODS: The authors analyzed two consecutive series of 60 and 50 patients operated by the same surgeon for a chronic rupture of the anterior cruciate ligament, one by reconstruction of the cruciate ligament with a free graft of the patellar tendon supplemented by an external extra-articular plasty made with a quadriceps tendon graft and the second with an isolated free patellar tendon graft. Anterior laxity was measured before and after surgery, by dynamic X-rays and by the Medmetric KT-1000 arthrometer. Functional results were evaluated four years after operation, with the French A.R.P.E.GE score based on sport activity level and intensity. RESULTS: Anterior laxity was not different before operation in both groups and there was no difference between males and females. Medmetric KT-1000 arthrometer showed the same negative differential laxity immediately after surgery in both groups and the same evolution during the first 4 years, without any significant difference on laxity on the middle aspect of the knee. Radiological results were different. After a 4 years follow-up, anterior laxity did not show significant difference on the medial compartment of the knee (5.3 +/- 2.3 mm and 5.5 +/- 1.7 mm), but there was a significant minor laxity in the lateral compartment for the lateral extra-articular plasty group (11.0 +/- 2.3 mm against 14.8 +/- 3.8 mm)(p = 0.002). Functional results and sport activity were similar in both groups. Examination showed 4 positive pivot shift tests (2 "sliding" and 2 positive) in the group with extra-articular plasty, even though 8 positive pivot shift tests in the isolated ACL group (5 "sliding" and 3 positive) were found. DISCUSSION: This study, as well as five others studies found in literature, was not randomized. In all these series, the surgical techniques, the rehabilitation programs and the functional score evaluation were too different to allow any pertinent comparison. Extra-articular plasty helps to control the laxity of the lateral compartment of the knee which is incompletely controlled by ACL reconstruction, particularly in chronic cases. This is proved by radiological measurements and pivot shift tests. Jensen in 1983, about 205 patients with a 4 year follow-up and Noyes, which used an allograft patellar tendon, found an advantage to do extra-articular plasty. But Strum (in 1989), as O'Brien (in 1991) and Roth (in 1987), did not found any advantage with extra-articular plasty. CONCLUSION: It is therefore obvious, after a four-year follow-up, that extra-articular supplementation presents an advantage for reconstruction of the ACL. by a free graft of the patellar tendon in chronic cases. Further randomized study will confirm that isolated ACL reconstruction is possible in some well defined categories of anterior laxity. 相似文献
28.
HG Garrison GL Foltin LR Becker JL Chew M Johnson GM Madsen DR Miller BH Ozmar 《Canadian Metallurgical Quarterly》1997,1(3):156-162
Recent studies have shown a high frequency of genetic hemochromatosis in the Caucasian population. In addition, the well known organ involvement of genetic hemochromatosis was evident; more than 50% of patients develop a typical arthropathy which may result in severe physical disability. Among approximately 5000 patients referred to the rheumatology outpatient clinics of Bad Nauheim and Frankfurt with different rheumatologic diagnoses, 11 patients with typical signs of hemochromatotic arthropathy were identified. In none of those cases had the diagnosis "genetic hemochromatosis" been previously established. These patients had been treated for rheumatoid arthritis and other rheumatologic disorders over several years. All showed severe organ dysfunction due to iron overload, resulting in a reduced life expectancy. This investigation shows that knowledge of the typical signs of hemochromatotic arthropathy could lead to an earlier diagnosis of genetic hemochromatosis which is necessary to prevent the complications of iron overload in those patients. 相似文献
29.
BACKGROUND: Inhaled nitric oxide (NO) has been shown to selectively lower pulmonary vascular resistance and is applied in patients with pulmonary hypertension (PHT). However, application and monitoring is complex and not always successful ("non-responders"). We evaluated the effect of aerolized prostacyclin (aePGI2) as a therapeutic alternate to NO. PATIENTS AND METHODS: aePGI2 and NO were applied to patients with different causes of pulmonary hypertension (Group 1a: preoperative patients with intracardiac shunting defects and Eisenmenger's disease, n = 30; Group 1b: patients with primary or postoperative PHT, n = 13; Group 2: PHT immediately following surgery for congenital heart disease, n = 6). RESULTS: Pulmonary vascular resistance could be lowered significantly (Group 1a: from 91% of systemic vascular resistance to 58% with NO and 53% with aePGI2; Group 1b: from 20.2 Wood Units*m2 to 13.4 and 11.3; Group 2: from 24.9 Wood Units*m2 to 9.5 and 10.5); cardiac index increased (Group 1b: from 2.96 to 3.55 and 3.96 l/min*m2, Group 2: from 1.57 to 1.89 and 2.00 l/min*m2). CONCLUSIONS: The short-term application of aePGI2 shows a selective pulmonary vasodilation similar to NO. Given adequate monitoring, aePGI2 appears to be useful for the acute treatment of PHT. 相似文献
30.
Single cysteine substitutions were introduced into three positions of otherwise cysteineless HtrI, a phototaxis transducer found in Halobacterium salinarum that transmits signals from the photoreceptor sensory rhodopsin I (SRI) to a cytoplasmic pathway controlling the cell's motility. Oxidative cross-linking of the monocysteine HtrI mutants in membrane suspensions resulted in dimer forms evident in SDS-polyacrylamide gels. The rate of cross-linking of I64C on the cytoplasmic side of HtrI was accelerated by SRI binding in the dark and further increased by SRI photoactivation. Several residue replacements of His-166 in SRI accelerated the cross-linking rate of I64C in the dark and His-166 mutants that exhibit "inverted signaling" (mediating repellent instead of the normally attractant response to orange light) inverted the light effect on the cross-linking rate of I64C. Secondary structure prediction of HtrI indicates a coiled coil structure in the cytoplasmic region following TM2, a dimerization domain found in a diverse group of proteins. We conclude that 1) HtrI exists as a dimer both in the absence of SRI and in the SRI-HtrI complex, 2) binding of SRI in the dark increases reactivity of the two cysteines at position 64 in the dimer by increasing their proximity or mobility, 3) light activation of wild-type SRI further increases their reactivity, 4) His-166 replacements in the SRI receptor have conformational effects on the structure of HtrI at position 64, and 5) inverted signaling by His-166 mutants likely results from an inverted conformational change at this region induced by SRI photoactivation. 相似文献