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Synthesis, absolute configuration, and analysis of malathion, malaoxon, and isomalathion enantiomers
Syntheses of the enantiomers of malathion, malaoxon, and isomalathion are reported herein. Malathion enantiomers were prepared from (R)- or (S)-malic acid in three steps. Enantiomers of malathion were converted to the corresponding enantiomers of malaoxon in 52% yield by oxidation with monoperoxyphthalic acid, magnesium salt. The four isomalathion stereoisomers were prepared via two independent pathways using strychnine to resolve the asymmetric phosphorus moiety. The absolute configurations of the four stereoisomers of isomalathion were determined by X-ray crystallographic analysis of an alkaloid salt precursor. A high-performance liquid chromatography technique was developed to resolve the four stereoisomers of isomalathion, and to determine their stereoisomeric ratios. 相似文献
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ME Jones MR Visser M Klootwijk P Heisig J Verhoef FJ Schmitz 《Canadian Metallurgical Quarterly》1999,43(2):421-423
The activities of eight fluoroquinolones and linezolid, quinupristin-dalfopristin (Synercid), gentamicin, and vancomycin were tested against 96 ciprofloxacin-susceptible and 205 ciprofloxacin-resistant Staphylococcus aureus strains. Overall, clinafloxacin, followed by moxifloxacin and trovafloxacin, was the most active quinolone tested. For all isolates, linezolid and quinupristin-dalfopristin showed activities that were at least comparable to vancomycin, with no cross-resistance to any other test compound. 相似文献
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GB Park PE Erdtmansky RR Brown MP Kullberg J Edelson 《Canadian Metallurgical Quarterly》1980,69(5):603-605
A GLC method, employing a nitrogen-phosphorus-sensitive detector, is described for the analysis of mepivacaine, bupivacaine, etidocaine, lidocaine, and tetracaine in biological fluids. The method is simple, reliable, and sensitive, with a practical limit of sensitivity of approximately 2.5 ng/ml, well below therapeutic plasma levels. Extensive start-up procedures and sample preparation are not required. 相似文献
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Summary A study was made of the conditions of preparation of gadolinium, terbium, dysprosium, erbium, thulium, and lutecium dicarbides by the method of vacuum reduction of oxides of the corresponding metals.It was established that 1800°C is the optimum temperature for the preparation of these dicarbides. It is assumed that the formation of the dicarbides at the same temperature is linked with the similarity of the electronic structures of the rare-earth metals.Translated from Poroshkovaya Metallurgiya, No. 8(56), pp. 34–38, August, 1967. 相似文献
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Langer Lilly M.; Zimmerman Rick S.; Warheit George J.; Duncan Robert C. 《Canadian Metallurgical Quarterly》1993,12(3):227
Examined how adolescents' personal sense of directedness (i.e., peer, parent, or self-directed orientation) affects the decision-making processes of adolescent students regarding AIDS-related knowledge, attitudes, beliefs, behaviors, and skills (KABBS). The sample consisted of 10th-grade students in 8 public high schools (N?=?2,515) in Dade County (greater Miami), Florida. The findings showed that decision-making orientation and directedness was a significant predictor of AIDS-related KABBS of adolescents. Overall, the level of AIDS-related KABBS that were associated with low risk was found significantly more often among self-directed students and least often among peer-directed students. The findings of this study suggest that future preadult health-risk research should incorporate the concept of differences of information processing across adolescents. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
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A. Roine 《Metallurgical and Materials Transactions B》1987,18(1):203-212
The effects of oxygen, nickel, and cobalt on the activity coefficients of As, Sb, Bi, and Pb in copper mattes were measured
at 1200 °C (1473.15 K) using the transportation method. The transportation experiments concerning the effect of oxygen were
carried out as a function of the SO2 content (1 to 100 vol pct) in the carrier gas and using high- and low-grade matte samples, ≈80 and ≈40 wt pct Cu, respectively.
The prevailing sulfur and oxygen partial pressures were evaluated on the basis of matte and carrier gas compositions. The
effect of the SO2 pressure on the activity coefficients was found to be very small compared with the effect of the sulfur pressure, whereas
the effect of the SO2 partial pressure on the vaporization behavior, especially of As, was very significant, due to the additional vaporization
of As as AsO gas molecules, which caused an increase in the As removal rate. At a higher oxygen partial pressure than 10−8.5 atm (3.2·10−4 Pa) a noticeable decrease in the Sb activity coefficients was observed due to the oxidation. This did not, however, decrease
the Sb removal rate, since the relative proportion of the oxide gas molecules in the gas phase increased simultaneously. The
interactions between dissolved Ni or Co and the impurity elements were investigated by doping (1 wt pct) the high grade (Cu
≈75 wt pct) matte samples with Ni or Co. At stoichiometric and sulfur-deficient matte compositions, Ni and especially Co decreased
the activity coefficients of As and Sb, but did not have any effect on the activity coefficients of Bi and Pb, compared with
the corresponding sulfur content in the Ni- and Co-free mattes. For mattes of higher sulfur content Ni and Co did not show
any marked effect on the activity coefficients of As, Sb, Bi, and Pb.
A. ROINE, formerly with Institution of Process Metallurgy, Helsinki University of Technology, SF-02150, ESPOO, Finland 相似文献
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AE Cooper AJ Gray J Collington H Seddon I Beattie CJ Logan 《Canadian Metallurgical Quarterly》1996,24(10):1071-1080
The excretion and metabolism of [3H]tipredane, a novel glucocorticoid, has been studied in mice, rats, marmosets, rhesus and cynomolgus monkeys, and humans. After oral administration, [3H]tipredane was rapidly absorbed, metabolized, and excreted into urine and feces. In mice and male rats, radioactivity was excreted primarily into feces or bile, whereas in female rats, monkeys, and humans, excretion was mainly via the renal route. Some sex differences in the proportions excreted into urine and feces were noted in rodents, with females eliminating relatively more radioactivity in urine. Tipredane was shown to be extensively metabolized, but the routes were highly species-dependent and, in the rat, they were sex-dependent. Unchanged tipredane was not detected in any urine, bile, or blood extracts. Urinary and blood extract profiles indicated that there were between 10 and 30 metabolites in rats and mice, the majority of which constituted < 2% of the dose. In these species, the major pathways involved loss of the thioethyl moiety, S-oxidation of the thiomethyl group, and saturation of the adjacent saturated C16-17 bond. Hydroxylation of the steroid B-ring was seen in the 7 alpha-position in mice and female rats, and in the 6 beta-position in male rats. Metabolism of tipredane in rhesus and cynomolgus monkeys and humans was similar, but less extensive and different to that seen in rodents. The major products, the 6 beta-hydroxylated sulfoxide and sulfone metabolites of tipredane, accounted for 21-36% of the dose in human and monkey urine, and were also major components in blood. In contrast to mice and rats, S-oxidation and an unsaturated C16-17 bond were evident in primates. Metabolism of tipredane was rapid and complex, with significant species differences, although the disposition in rhesus and cynomolgus monkeys seemed to be similar to humans. 相似文献
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Mycobacterium avium is an intracellular pathogen that is associated with disseminated infection in acquired immunodeficiency syndrome (AIDS). Patients with AIDS appear to acquire M. avium mainly through the gastrointestinal tract. Previous studies have shown that healthy mice given M. avium orally develop disseminated infection after 2-4 weeks. The chief site of M. avium invasion of the intestinal mucosa is the terminal ileum. To learn more about the pathophysiology of M. avium infection of the intestinal mucosa, C57BL/6 bg+ bg+ mice were infected orally with M. avium strain 101 and groups of six mice were killed each week for 8 weeks. The terminal ileum was then prepared for histopathological studies and electron microscopy. A delayed inflammatory response was observed and influx of neutrophils in the Peyer's patches was the only abnormality seen at 1 week. A severe inflammatory response was seen from week 2 to week 5 and necrosis of intestinal villi was observed 6 weeks after infection. These results indicate that invasion and infection of the normal intestine by M. avium results in a severe inflammatory response with segmental necrosis of the intestinal mucosa. 相似文献
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The response of a saturated fine sand (Nevada sand No. 120) with relative density Dr ≈ 70% in drained and undrained conventional triaxial compression and extension tests and undrained cyclic shear tests in a hollow cylinder apparatus with rotation of the stress directions was studied. It was observed that the peak mobilized friction angle for this dilatant material was different in undrained and drained tests; the difference is attributed to the fact that the rate of dilation is smaller in an undrained test than it is in a drained test. Consistent with the findings of others, the material is more resistant to undrained cyclic loading for triaxial compression than for triaxial extension. In rotational shear tests in which the second invariant of the deviatoric stress tensor is held constant, the shear stress path (after being normalized by the mean normal effective stress) approached an envelope that is comparable but not identical in shape to a Mohr-Coulomb failure surface. As the stress path approached the envelope, the shear end deviatoric strains continued to increase in an unsymmetrical smooth spiral path. During the rotational shear tests, the direction of the deviatoric strain-rate vector (deviatoric strain increment divided by the magnitude of change in Lode angle) was observed to be about midway between the deviatoric stress increment vector and the normal to a Mohr-Coulomb failure surface in the deviatoric plane. The stress ratio at the transition from contractive to dilative behavior (i.e., “phase transformation”) was also observed to depend on the direction of the stress path; therefore this stress ratio is not a fundamental property. Results from torsional hollow cylinder tests with rotation of stress directions are presented in new graphical formats to help understand and interpret the fundamental soil behavior. 相似文献
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Measures of the amounts of time infants spent asleep, awake-content, feeding, fussing, and crying at 2, 6, 12, and 40 weeks of age were examined using multilevel analysis. This method enables the proportion of the variance in each behavior due to individual differences to be compared to the proportion due to age changes (development) and to day-to-day fluctuations at each age in the same infants. Day-to-day fluctuations were found to account for the largest proportion of the variance in amounts of sleeping, fussing, and crying (between 44% and 53%), testifying to the importance of instability in these behaviors as a characteristic of infancy. Against this background, both development and individual differences explained substantial proportions of the variance, with a somewhat different picture in each area of behavior. Amounts of waking and feeding were mainly accounted for by development, and no evidence of enduring individual differences was found. For sleeping, development and individual difference each contributed approximately a quarter of the variance, and the amounts infants slept remained moderately stable from 6 weeks to 9 months of age. Crying decreased linearly with age, with development accounting for 38% and individual difference 15% of the variance. Fussing proved a more stable characteristic than crying, and "high fussers" at 6 weeks of age were particularly likely to retain this characteristic at 9 months, whereas amount of crying in the first 3 months did not predict 9-month behavior. The study's clinical, conceptual, and methodological implications are discussed. 相似文献
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M Prenna MP Montanari M Mingoia F Biavasco S Ripa PE Varaldo 《Canadian Metallurgical Quarterly》1998,17(11):816-819
BACKGROUND: Use of blood culture studies for early diagnosis of Mycobacterium avium complex (MAC) infection has become important due to the recent development of effective antibiotic therapy for this condition. This study assessed the abdominal computed tomography (CT) findings in patients with AIDS who presented with bacteraemic MAC infection. METHODS: A retrospective analysis of abdominal CT scans was performed in 24 patients who presented with MAC-positive blood culture. CT images were reviewed specifically to evaluate for lymph node enlargement and attenuation, hepatomegaly, splenomegaly, bowel wall abnormality and for any other pathological changes. Comparison was made to prior reports of the CT findings in this disease process. RESULT: Enlarged intra-abdominal mesenteric and/or retroperitoneal lymph nodes were found in 10 patients (42%). These nodes were characterized by homogeneous, soft-tissue attenuation in eight of the 10 patients. Hepatomegaly, splenomegaly and small bowel wall thickening were noted in 12 (50%), 11 (46%) and four (14%) patients, respectively. CT findings were evaluated as normal in six (25%) patients. CONCLUSIONS: Enlarged mesenteric and/or retroperitoneal lymph nodes in AIDS patients with bacteraemic MAC were observed much less frequently on CT than previously reported in AIDS patient populations. Normal abdominal CT findings do not exclude this diagnosis and may reflect a trend towards earlier detection of MAC disease. 相似文献
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M Geyer U Zwiener E Bartel HC Scholle D Goldammer 《Canadian Metallurgical Quarterly》1976,28(6):367-374
A total of ninety women classified into three groups (with cardiovascular, depressive, and other principal symptoms) according to clinical criteria were characterized by clinico-anamnestic, psychological, and psychophysiological data with the goal of arriving at a practically oriented differentiation of neurotic syndromes. The relevant variables were determined by means of a factor analysis. The physiological reaction patterns determined in experiments on psychically strained individuals proved unsuitable for the differentiation of the two syndromes. The problems associated with a symptom-oriented classification are discussed. 相似文献
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Balsam Kimberly F.; Beauchaine Theodore P.; Mickey Ruth M.; Rothblum Esther D. 《Canadian Metallurgical Quarterly》2005,114(3):471
Self-identified lesbian, gay male, and bisexual (LGB) individuals were recruited via convenience sampling, and they in turn recruited their siblings (79% heterosexual, 19% LGB). The resulting sample of 533 heterosexual, 558 lesbian or gay male, and 163 bisexual participants was compared on mental health variables and their use of mental health services. Multilevel modeling analyses revealed that sexual orientation predicted suicidal ideation, suicide attempts, self-injurious behavior, use of psychotherapy, and use of psychiatric medications over and above the effects of family adjustment. Sexual orientation was unrelated to current psychological distress, psychiatric hospitalizations, and self-esteem. This is the 1st study to model family effects on the mental health of LGB participants and their siblings. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
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Stiffness of the vocal fold is a significant factor in determining mucosal wave propagation and in the control of the fundamental frequency of phonation. We measured pliability of the vocal fold mucosa in an in vivo canine model as an index of stiffness while the histological layer-by-layer structure of the vocal fold was not disrupted. The point 1 mm below the free edge showed a maximal pliability that gradually diminished toward the tracheal side and reached a minimum. When the thyroarytenoid (TA) muscle contracted, pliability of the mucosa was significantly increased (P < 0.001). Mucosal pliability of the excised larynx was significantly increased compared with that in vivo (P < 0.001). The point of minimal pliability in the absence of TA muscle contraction did not shift after excision of the larynx, while TA muscle contraction caused a downward shift of the point of minimal pliability. Mucosal pliability can thus be used to quantitatively assess the effects of TA muscle contraction on stiffness of the vocal fold mucosa. 相似文献