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121.
I. Mukhopadhyay R. M. Lees W. Lewis-Bevan J. W. C. Johns F. Strumia G. Moruzzi 《Journal of Infrared, Millimeter and Terahertz Waves》1987,8(11):1483-1502
High-resolution infrared (IR) and far infrared (FIR) Fourier transform absorption spectra have been employed to investigate assignments of FIR laser lines reported from optically-pumped13CH3OH. The spectroscopic measurements are used in conjunction with the reported IR pump and FIR laser frequencies to form closed combination loops for several systems, serving to confirm the assignments and in some cases to improve the accuracy of the FIR laser frequencies. Frequency predictions from combination differences are also presented for a number of potential new FIR laser lines. 相似文献
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PURPOSE: To examine relationships between tobacco use and use of other substances among U.S. high school students, by gender and racial/ethnic subgroups. METHODS: Data about tobacco and other substance use were analyzed from the 1995 national Youth Risk Behavior Survey implemented by the Centers for Disease Control and Prevention. RESULTS: Compared to nonsmokers, current smokers were significantly more likely to report use of all other substances we examined, including lifetime use of cocaine, inhalants, other illegal substances, and multiple substances and current alcohol use, episodic heavy drinking, marijuana use, and cocaine use. A strong dose-dependent relationship between current cigarette smoking and other substance use was identified. Among smokeless tobacco users, a strong dose-dependent relationship was found for all examined substances with the exception of lifetime and current cocaine use. Finally, a pattern of risk emerged suggesting that the likelihood of other substance use increases as students move from no tobacco use to smokeless tobacco use only, to cigarette smoking only, and to use of both smokeless tobacco and cigarettes. CONCLUSIONS: Programs designed to prevent tobacco or other substance use should consider that such use often occurs concomitantly. 相似文献
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OBJECTIVE: To determine whether clinical parameters could be used to differentiate clinical mastitis (CM) caused by gram-positive bacteria from CM caused by gram-negative bacteria in dairy cows vaccinated against lipopolysaccharide core antigens. DESIGN: Case series. ANIMALS: 143 episodes of CM in 86 dairy cows in a single herd. PROCEDURE: Cows were examined at onset of CM, and 24 clinical parameters including rectal temperature, heart rate, rumen contraction rate, degree of dehydration, various udder and milk characteristics, lactation number, stage of lactation, and season of year were recorded. Milk production and milk constituent concentrations before onset of CM were obtained from Dairy Herd Improvement Association records. Values for cows with gram-negative CM were compared with values for cows with gram-positive CM. Logistic regression was used to identify important predictors of gram-negative CM. RESULTS: 64 (45%) CM episodes were caused by gram-negative bacteria and 79 (55%) were caused by gram-positive bacteria. Rumen contraction rate was significantly lower and milk protein percentage before onset of CM was significantly higher in cows with gram-negative, rather than gram-positive, CM. Logistic regression indicated that CM was more likely to have been caused by gram-negative bacteria if it developed during the summer, milk was watery, or rumen contraction rate was low. Sensitivity and specificity of the final regression model were 0.58 and 0.80, respectively. Predictive value of a positive result was 0.74 when proportion of CM episodes caused by gram-negative bacteria was assumed to be 50%. CLINICAL IMPLICATIONS: Results suggest that clinical observations do not allow accurate prediction of CM pathogens and should not be the sole criteria for deciding whether cows with CM are treated with antibiotics. 相似文献
127.
Histatin 1 is a histidine-rich phosphoprotein present in human parotid saliva that possesses candidacidal activity and functions in mineralization by adsorbing to hydroxyapatite. The objective of the present study was to develop a system for recombinant production of histatin 1 and to examine the role of phosphorylation in the functional activities of this molecule. Native histatin 1 (containing a phosphoserine at residue 2) was purified from parotid saliva, whereas a bacterial expression system was used to produce a recombinant form of histatin 1 (re-Hst1) that lacked phosphorylated serine. Histatin 1 cDNA was inserted into the vector pGEX-3X, which expresses foreign genes as soluble fusion proteins attached to the carboxyl-terminus of glutathione S-transferase (GST). The GST/re-Hst1 fusion protein was isolated from cell lysates by affinity chromatography on glutathione (GSH)-Sepharose and digested with cyanogen bromide to separate re-Hst1 from the GST fusion partner. The digest was subjected to reversed-phase high-performance liquid chromatography on a C18 column, and re-Hst1 was eluted as a well-defined peak. The yield of re-Hst1 was 4 mg/L of bacterial culture. Amino-terminal sequencing and amino acid analysis confirmed the final product as re-Hst1. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) showed that native histatin 1 and re-Hst1 had the same apparent molecular weights, while cationic PAGE showed that re-Hst1 was more basic. Phosphate analysis indicated 1 mol phosphate/mol of native histatin 1, while re-Hst1 lacked any detectable phosphate. Re-Hst1 demonstrated candidacidal activity comparable to that of native histatin 1, but displayed substantially lower binding to hydroxyapatite. These results show that phosphorylation of histatin 1 at residue 2 contributes significantly to its ability to bind to hydroxyapatite. 相似文献
128.
Amyloidosis is characterized by deposition of protein fibrils in various tissues. The wide variety of sequences of both amyloidogenic and non-amyloidogenic immunoglobulin light chains makes them a unique tool for addressing the importance of primary structure in the formation of insoluble fibrils. In this study, we have determined the primary structure of the kappa I immunoglobulin light chain from both the urinary Bence Jones protein and the deposited amyloid fibrils of a patient (MH) with primary amyloidosis. The sequence identity of urinary-excreted and tissue-deposited light chains excluded biclonality and somatic mutations and confirmed that the light chain existed in both a soluble and an insoluble form. Several residues have been previously reported to be significantly associated with amyloidogenic kappa chains. Many of these were found in the MH sequence, including Asp31, Asn45, Phe49, Gln55, His70, Asn/Gly93 and ProN/Val96, thereby supporting their potential role in fibrillogenesis. In addition, Asn20 and Pro60 of protein MH replaced the normally conserved Thr20 and Ser60. Asn20 was glycosylated in both the Bence Jones and the amyloid fibril protein MH. Cumulative effects of amyloid-associated residues and glycosylation might have rendered the immunoglobulin light chain MH prone to fibril formation. 相似文献
129.
''Oncocheck'': an international external quality assessment scheme for immunoassays of tumor markers
R Cohen GC Zucchelli M Fraysse A Pilo MY Rigault S Grillet CA Bizollon 《Canadian Metallurgical Quarterly》1994,21(3):483-493
Coccidia were isolated from 122 Belgian broiler farms without clinical coccidiosis. Shuttle programs including robenidin or nicarbazine in the starter (7-14 days) followed by an ionophore or diclazuril in the grower ration were most commonly used. Out of 215 coccidiosis-positive groups, 146 Eimeria acervulina, 65 E. maxima, and 88 E. tenella isolates were tested without further laboratory propagation in 17 sensitivity profiles. For each profile, oocytes were pooled from 9 +/- 4 farms (mean +/- SD) that used the same anticoccidial program and that belonged to the same integrated broiler operation. Each suspension contained an equal number of isolates and oocyst numbers from each farm tested. Each profile included an unmedicated uninfected group, an unmedicated infected group, and 11 medicated infected groups, consisting each of three replicates of three Ross chicks. Medication started at 8 days of age, and each inoculated bird received 50,000 sporulated oocysts at 10 days. Results were related to the anticoccidial program that had been in use. Chemical drugs showed the highest activity against Eimeria, whereas ionophores were less efficacious. Of the latter, monensin (110 ppm) was least active; narasin (70 ppm), salinomycin (60 ppm), and maduramicin (5 ppm) took an intermediate position, and lasalocid (90 ppm) was most active. A 50% improvement in weight gain was obtained in 7 to 10 out of 17 profiles with 100 + 8.35 ppm clopidol/methylbenzoquate (10), 125 ppm nicarbazin (9), 3 ppm halofuginone (8), and 1 ppm diclazuril (7). A 50% improvement in feed conversion was obtained in 7 to 11 profiles with nicarbazin (11), halofuginone (10), diclazuril (9), 33 ppm robenidine (9), clopidol/methylbenzoquate (7), and lasalocid (7). Based on relative oocyst output, the highest activity against E. acervulina was obtained with clopidol/methylbenzoquate (8/16); the highest activity against E. maxima was obtained with lasalocid (6/6), diclazuril (5/6), and halofuginone (5/6); and the highest activity against E. tenella was obtained with diclazuril (8/8), amprolium/ethopabate (5/8), halofuginone (4/8), maduramicin (4/8), and nicarbazin (4/8). 相似文献
130.