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291.
A simple method for analyzing nitrite in urine has been developed to confirm and quantify the amount of nitrite in potentially adulterated urine samples. The method involved separation of nitrite by capillary electrophoresis and direct UV detection at 214 nm. Separation was performed using a bare fused silica capillary and a 25 mM phosphate run buffer at a pH of 7.5. Sample preparation consisted of diluting the urine samples 1:20 with run buffer and internal standard, and centrifuging for 5 min at 2500 rpm. The sample was hydrodynamically injected, then separated using -25 kV with the column maintained at 35 degrees C. The method had upper and lower limits of linearity of 1500 and 80 microg/mL nitrite, respectively, and a limit of detection of 20 microg/mL. The method was evaluated using the National Committee for Clinical Laboratory Standards (NCCLS) protocol (Document EP10-A2), and validated using controls, standards, and authentic urine samples. Ten anions, ClO-, CrO4(-2), NO3-, HCO3-, I-, CH3COO-, F-, SO4-, S2O8(-2), and Cl-, were tested for potential interference with the assay. Interferences with quantitation were noted for only CrO4(-2) and S2O8(-2). High concentrations of Cl- interfered with the chromatography. The method had acceptable accuracy, precision, and specificity. 相似文献
292.
Suppression of environmental science 总被引:1,自引:0,他引:1
Kuehn RR 《American journal of law & medicine》2004,30(2-3):333-369
293.
Sharma AN Nelson LS Hoffman RS 《The American journal of forensic medicine and pathology》2004,25(2):156-158
The neurologic manifestations of thallium poisoning include a severely painful ascending peripheral neuropathy, autonomic dysfunction, cranial nerve abnormalities, and a toxic encephalopathy. Although thallium has a short half-life, these neurologic manifestations commonly progress, even as the blood concentration of thallium decreases. This suggests either that thallium persists in neuronal tissues or that it initiates an injury cascade that takes time to fully manifest. As the latter mechanism is consistent with many toxin exposures, the concept of a central nervous system reservoir for thallium is often discounted. A recent case provided a unique opportunity to evaluate this possibility. A 48-year-old man was acutely and chronically thallium poisoned by his common-law wife. During his initial exposures, only gastrointestinal symptoms manifested. Following an acute ingestion, hospitalization was required. Over 3 days, his symptoms rapidly progressed from a severely painful neuropathy to slurred speech, ptosis, confusion, coma, respiratory insufficiency, and death. Because of considerations of alternative diagnoses, 2 lumbar punctures were performed, one on admission and another on the day of his death. Serum thallium concentrations obtained from stored blood samples were paired with spinal fluid concentrations from the same days. On day 1, serum and spinal fluid concentrations were 8700 mu/L and 1200 mu/L, respectively. On day 3, although the serum concentration had fallen to 7200 mu/L, the spinal fluid concentration had increased to 2100 mu/L. This case provides evidence to support the hypothesis that thallium distributes into the central nervous system more slowly than the blood compartment, and this may in part account for the progression of neurologic findings in the setting of decreasing serum concentrations. 相似文献
294.
The authors present a case of sudden death in a previously healthy 36-year-old male. At autopsy there were bilateral pulmonary thromboemboli and right ventricular dilatation. Histologic findings in the lungs included recanalized, old thrombi and evidence of pulmonary hypertension. Genetic analysis for hereditary risk factors was heterozygous positive for the prothrombin G20210A mutation. Implications of this finding, its history and the diagnostic technique shall be discussed. The authors recommend that all cases of deep venous thromboses and pulmonary thromboemboli lacking known risk factors be evaluated for newly described genetic variations associated with an increased risk for venous thrombosis. 相似文献
295.
Cowell RG 《Forensic science international》2003,134(2-3):196-206
A series of recent papers have shown how to formulate complex problems of forensic DNA identification inference, such as occur in disputed paternity or criminal identification cases, in terms of Probabilistic Expert Systems (PESs). However, at the present time, general purpose PES software is not particularly well suited to the repetitive tasks of: specifying an appropriate set of marker networks for a specific problem; for editing the many local conditional probability tables; and combining evidence from several genetic markers to evaluate likelihoods. Here, I describe a user-friendly prototype software tool called FINEX developed both to automate such tasks and also to evaluate likelihoods of interest. Ease of use is achieved by a graphical specification language that enables a user to quickly specify a range of forensic DNA problems. I describe the algorithms by which FINEX converts the user input in the graphical specification language and data on observed markers to the Bayesian networks used in PES. 相似文献
296.
LaPorte GM Wilson JD Mancke SA Payne JA Ramotowski RS Fortunato SL 《Journal of forensic sciences》2003,48(5):1163-1171
Thermal transfer printing refers to printing processes that utilize heat to produce an image by either physical or chemical means or by a combination of both. As the technology has improved and the supplies have become less expensive, the use of thermal printing in the personal and business markets has increased significantly. Specifically, dye diffusion thermal transfer and thermal mass transfer have become predominant in the production of counterfeit credit cards, drivers' licenses, and other types of documents produced on plastic media. Chemical analysis by means of thin layer chromatography (TLC) has proven to be useful in characterizing various types of inks (e.g., writing and inkjet inks). In this study, the authors examined 81 different samples that included a total of 54 printer samples (43 photographic prints on paper and eleven plastic card samples) and 27 printer ribbons. A new TLC method was developed and tested utilizing a solvent system (80% n-hexane, 3% methyl ethyl ketone, and 17% ethyl acetate) that is capable of producing excellent resolution. 相似文献
297.
Gruszecki AC Kloda S Simmons GT Daly TM Hardy RW Robinson CA 《Journal of forensic sciences》2003,48(2):432-434
A 29-year old female with a history of depression was found dead in a hotel room. The death scene investigation found empty pill bottles and an empty liter bottle of wine. Metaxalone, a centrally acting muscle relaxant, along with citalopram, ethanol, and chlorpheniramine were identified in the postmortem samples and quantitated by gas chromatography-mass spectrometry. The concentration of metaxalone in femoral vein blood was 39 mg/L. The heart blood concentration was 54 mg/L. Femoral vein blood concentrations of citalopram and chlorpheniramine were 0.77 mg/L and 0.04 mg/L, respectively. Ethanol levels were 0.13 g/dL in vitreous and 0.08 g/dL in heart blood. Other tissue samples were also analyzed. The authors consider the metaxalone concentrations toxic and potentially fatal. The citalopram concentrations were lower than those reported in fatal cases for this drug alone. Death was ascribed to polydrug abuse/overdose with metaxalone a major contributor. This represents the first reported case to our knowledge in which a metaxalone overdose significantly contributed to death. 相似文献
298.
Subject Acquisition for Web-Based Surveys 总被引:1,自引:0,他引:1
299.
Disability has high societal and personal costs. Various disparate federal and state programs attempt to address the economic and social needs of people with disabilities. Presumably workplace injuries and accidents are an important source of disability. Yet separate public policies and research literatures have evolved for these two social problems--disability and workplace injuries--despite their relatedness. This article seeks to document the overlap between these two phenomena in estimating the proportion of the disabled population whose disability was caused by workplace injury, accident, or illness using the Health and Retirement Study of 1992. The results point toward the need for initiatives to reduce disability that focus on work-related causes, which are a common pathway to disability, and that may result in substantial savings in federal programs. 相似文献
300.
Though the link between democracy and an appropriately trained citizen is obvious, the theoretical and empirical nature of this association is murky despite mountains of scholarship addressing this topic. Part of this problem is that the term democratic competence has been stretched almost to the point of uselessness. This constant adding of desired traits—many of which are ideologically driven—misdirects effort away from such complex problems as the relationship between individual attributes and collective capacities. Moreover, recent research has often been guilty of using data of uncertain relevance to demonstrate a competence that seems largely an analytical artifact. We conclude by offering an approach that stresses old- fashioned traits such as patriotism that seem necessary to the existing, and quite democratic, status quo. 相似文献