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A single-laboratory validation study of a method for screening and identification of phosphodiesterase type 5 (PDE5) inhibitors in dietary ingredients and supplements is described. PDE5 inhibitors were extracted from the samples using a 50:50 (v/v) mixture of acetonitrile and water and centrifuged. Supernatant was diluted, filtered, and analyzed by LC–high-resolution MS. Data were collected in MS acquisition mode that combined full-scan MS experiment with all-ion fragmentation and data-dependent MS/MS product from the ion scan experiment. This approach enabled collection of MS and tandem MS (MS/MS) data for both targeted and nontargeted PDE5 inhibitors in a single chromatographic run. Software-facilitated identification of targeted analytes was performed based on the retention time, accurate mass, and isotopic pattern of pseudomolecular ions, and accurate masses of fragment ions using an in-house compound database. Detection and identification of other PDE5 inhibitors and novel analogs were performed by retrospective evaluation of MS and MS/MS experimental data. The method validation results obtained for evaluated matrixes fulfilled the probability of identification requirements and probability of detection requirements (for the pooled data) set at 90% (95% confidence interval) in the respective AOAC Standard Method Performance Requirements for identification and screening methods for PDE5 inhibitors. Limited data demonstrating the quantification capability of the method were also generated. Mean recovery and repeatability obtained for the evaluated PDE5 inhibitors were in the range 69–90% and 0.4–1.8%, respectively.

In this study, sponsored by PepsiCo Inc., a method was validated for measurement of 11 pesticide residues in soft drinks and sports drinks. The pesticide residues determined in this validation were alachlor, atrazine, butachlor, isoproturon, malaoxon, monocrotophos, paraoxon-methyl, phorate, phorate sulfone, phorate sulfoxide, and 2,4-dichlorophenoxyacetic acid (2,4-D) when spiked at 0.100 g/L (1.00 g/L for phorate). Samples were filtered (if particulate matter was present), degassed (if carbonated), and analyzed using liquid chromatography with tandem mass spectrometry. Quantitation was performed with matrix-matched external standard calibration solutions. The standard curve range for this assay was 0.0750 to 10.0 g/L. The calibration curves for all agricultural residues had coefficient of determination (r2) values greater than or equal to 0.9900 with the exception of 2 values that were 0.9285 and 0.8514. Fortification spikes at 0.100 g/L (1.00 g/L for phorate) over the course of 2 days (n = 8 each day) for 3 matrixes (7UP, Gatorade, and Diet Pepsi) yielded average percent recoveries (and percent relative standard deviations) as follows (n = 48): 94.4 (15.2) for alachlor, 98.2 (13.5) for atrazine, 83.1 (41.6) for butachlor, 89.6 (24.5) for isoproturon, 87.9 (24.4) for malaoxon, 96.1 (9.26) for monocrotophos, 101 (25.7) for paraoxon-methyl, 86.6 (20.4) for phorate, 101 (16.5) for phorate sulfone, 93.6 (25.5) for phorate sulfoxide, and 98.2 (6.02) for 2,4-D.

In conjunction with an AOAC Task Group on dietary supplements, a liquid chromatography/tandem mass spectrometry (LC–MS/MS) method was validated for measurement of 6 major alkaloids in raw ephedra sinica herb, ephedra extracts, ephedra tablets, complex dietary supplements containing ephedra, and a high-protein drink mix containing ephedra. The amount of ephedrine-type alkaloids present was determined by LC with mass selective detection. Six replicates of each matrix were analyzed on 3 separate occasions. The presence of 6 ephedrine-type alkaloids was detected at a level >0.5 μg/g based on a 0.5 g sample. The standard curve range for this assay is from 0.02 to 1.0 μg/mL. Appropriate dilutions covered a wide range of specific alkaloid concentrations. The calibration curves for all 6 analytes had correlation coefficients >0.995.

By forcing the CVD-W reactor in extreme starvation conditions it is possible to obtain low (tensile or compressive) stress tungsten film even at wafer temperatures as low as 400 o C. By combining different steps it is possible to come to a deposition process which can be used for all (interconnect, contact fill, and via fill) application needs in ULSI metallization systems. Using a sample population in which the stress varies more than one order of magnitude, the origin of the stress in the tungsten film is studied further using a substrate bending method for macrostress determination and x-ray techniques for microstress determination and grain size. Microstress in the grains can be higher than the corresponding macrostress of the film

Moderate alcohol consumption is associated with a decreased risk of coronary artery disease. The mechanism of the putative protective effect of alcohol intake, however, remains elusive. Recent studies suggest that a ratio of apolipoprotein A-I/apolipoprotein B and Lp(a) are better indicators of the risk of atherosclerosis than total cholesterol and high density lipoprotein cholesterol. To assess the effect of alcohol on these analytes, we determined the concentration of Lp(a), apolipoprotein A-I, apolipoprotein B, total cholesterol, and high-density lipoprotein cholesterol, and calculated low-density lipoprotein cholesterol in serum of 12 patients meeting DSM-III-R criteria for alcohol dependence at the time of admission for treatment of alcohol withdrawal (before). The analyses were repeated after 4 weeks of supervised abstinence on a locked research unit (after). With abstinence, there was a significant increase in the concentration of Lp(a), the atherogenic index and the ratio of low-density to high-density lipoprotein cholesterol but a significant decrease in total cholesterol, high-density lipoprotein cholesterol, apolipoprotein A-I, and the apolipoprotein A-I/B ratio. Apolipoprotein B and low-density lipoprotein cholesterol showed no significant changes before and after alcohol abstinence. Thus, decreased Lp(a) and increased high-density lipoprotein cholesterol and apolipoprotein A-I may be factors mediating the putative protective effect of alcohol in coronary artery disease.

Three hundred and eight subjects were screened over the phone for admission to an inpatient alcohol treatment research unit. Using a structured interview, the prospective patients were asked questions regarding demographics, drinking history, previous treatments, physical health, family history, and a detailed history of past and present substance use. Drug use was studied as regular use versus no use or brief experimental use of five drug categories: cannabinoids, stimulants, sedatives, opiates, and hallucinogens. Fifty-one percent of the men and 48% of the women reported regular use of one or more of the drugs in addition to alcohol. For women, the amount of alcohol intake was positively correlated with use of stimulants (r = .32, p = .001), cannabinoids (r = .24, p = .019), sedatives (r = .30, p = .003), and hallucinogens (r = .30, p = .003). For men, correlations between the amount of alcohol intake and drug use were weaker but significant for stimulants (r = .21, p = .002), opiates (r = .15, p = .028), and hallucinogens (r = .15, p = .029). Women with alcoholic mothers displayed higher alcohol intake than women with nonalcoholic mothers (p = .02) and also showed more frequent use of most drugs. Although men with alcoholic fathers also showed greater alcohol intake compared to men with nonalcoholic fathers, the two groups did not differ in drug use. Younger subjects of both sexes were more likely to use cannabinoids, stimulants, opiates, and hallucinogens. Alcohol and sedative use was relatively constant across all age groups.

The growth, structure, and thermal stability of ultra-thin metal films (Rh on Ag(100); Au on Pd(110) and Pt on Pd(110)) is investigated using surface sensitive techniques. The three systems studied present a variety of differing characteristics which can contribute to the growth mode, two-dimensional structure, and thermal stability of the films. The main factors contributing to the differing properties of the three systems presented here are: (1) the different substrate morphologies; (2) the differences in surface free energies between the overlayer and the substrate; (3) the degree of lattice mismatch for a particular system; and (4) the extent of miscibility of the two metals. 200 refs., 38 figs.

SummaryThe limited evidence in this paper supports the claim that hemorrhagic shock profoundly alters the morphology of the motor end plates and finally produces loss of structural innervation of many muscle fibers in a single voluntary muscle. This histologic change is highly irregular in the different muscles of the rat, therefore large numbers of specimens from different muscles were teased. Gold staining masses of axonic materials drain out into and between the muscle fibers coincident in time with the loss of motor innervation due to the increased permeability of the end plates. The epilemmal axons, exhausted of their substances, are in many places likewise denuded of their hypolemmal end plates. There is therefore a real anatomic breakdown of many motor end plates and histologic alteration of certain skeletal muscles in hemorrhagic shock.