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21.
We demonstrate large area two-dimensional arrays of patterned nanoporous gold for use as easy-to-fabricate, cost-effective, and stable surface enhanced Raman scattering (SERS) templates. Using a simple one-step direct imprinting process, subwavelength nanoporous gold (NPG) gratings are defined by densifying appropriate regions of a NPG film. Both the densified NPG and the two-dimensional grating pattern are shown to contribute to the SERS enhancement. The resulting substrates exhibit uniform SERS enhancement factors of at least 10(7) for a monolayer of adsorbed benzenethiol molecules. 相似文献
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23.
LJ Conley TJ Bush SP Buchbinder KA Penley FN Judson SD Holmberg 《Canadian Metallurgical Quarterly》1996,10(10):1121-1126
OBJECTIVE: To clarify the effect of cigarette smoking on the development of conditions associated with HIV infection. DESIGN: Prospective and retrospective cohort study, with interview and examination twice a year since 1988. METHODS: Data on 516 HIV-infected men from cohorts of homosexual and bisexual men in San Francisco, Denver and Chicago, who were repeatedly interviewed and examined between 1988 and 1992, were analysed. After excluding men who did not have well-defined dates of seroconversion and those who were classified as ex- or intermittent smokers, 232 men remained for analysis: 106 were smokers and 126 were non-smokers. Univariate and Kaplan-Meier survival analyses were performed to assess the relationship between cigarette smoking and loss of CD4+ T-lymphocytes, diagnosis of any AIDS-defining illness, and specific diagnosis of Kaposi's sarcoma, Pneumocystis carinii pneumonia (PCP), oral candidiasis, hairy leukoplakia, and community-acquired pneumonia. RESULTS: By univariate analyses, cigarette smoking was not associated with clinical AIDS, loss of CD4+ cells, Kaposi's sarcoma or PCP, but was significantly associated with oral candidiasis [relative risk (RR), 1.32; 95% confidence interval (CI), 1.02-1.70], hairy leukoplakia (RR, 1.51; 95% CI, 1.15-1.99), and community-acquired pneumonia (RR, 2.62; 95% CI, 1.30-5.27). Dose-response effect was also evident for these three conditions (all P < 0.01). Kaplan-Meier survival analysis indicated no association between cigarette smoking and time of progression to clinical AIDS, Kaposi's sarcoma (KS), or PCP (P = 0.62, 0.54 and 0.11, respectively) but showed that cigarette smokers developed oral candidiasis, hairy leukoplakia, and pneumonia more quickly than non-smokers (P = 0.031, 0.006 and 0.009, respectively). CONCLUSIONS: Cigarette smoking was not associated with an increased likelihood or rate of developing KS, PCP or AIDS, but was associated with developing community-acquired pneumonia, oral candidiasis, and hairy leukoplakia in these HIV-infected men. 相似文献
24.
This report describes an unusual nasal foreign body in a 4-year-old boy discovered incidentally in a routine dental radiograph. A small piece of rubber eraser was lodged in the right nasal cavity, causing unilateral nasal obstruction and discharge, sneezing, snoring and breathing difficulty. In this case, discovery of unknown intranasal object was diagnostic for a condition suspected of pathological origin. Dentists may play a significant role in the diagnosis of intranasal foreign objects in children, through careful clinical examination and interpretation of dental radiographs. Early diagnosis is emphasized in order to avoid complications. 相似文献
25.
Recent years have witnessed a renewed interest in plants as pharmaceuticals in the Western world. This interest is channeled into the discovery of new biologically-active molecules by the pharmaceutical industry and into the adoption of crude extracts of plants for self-medication by the general public. In both of these areas some attention is being paid to the investigation and use of ethnopharmacology, the traditional use of plants for medicinal purposes by particular cultural groups. Ethnopharmacologic leads have resulted in the introduction of new single molecule drugs but have a greater role to play if crude extracts are accepted for clinical use in the West. The problems confronting such usage are discussed. Considerable benefits for developing countries are possible when the local medicinal plants are subjected to scientific methods of validation of traditional use and quality control. This approach has met with success in some parts of the world but is not always appreciated by national governments and international agencies. Related areas of concern such as conservation of ecology and culture must be integrated with any such program. Plants used in traditional medicine therefore have an important role to play in the maintenance of health in all parts of the world and in the introduction of new treatments. 相似文献
26.
As the effects on injury scaling of the differences between the 1980 and 1985 revisions of the AIS are unknown in blunt trauma, we compared them in all 1270 critically injured (median ISS, 26) blunt trauma patients (75% male, 74% road crash, overall mortality 17%) admitted to the Department of Critical Care Medicine at Auckland Hospital from 1983 through 1987. In 911 patients (72%) there were no differences between AIS-80 and AIS-85 in any body region or in derived ISS. Changes in AIS grades were most common in the abdomen (205 patients), thorax (100 patients), and head (61 patients) regions. Median ISS overall for the 1270 patients was unchanged at 26. One percent of patients had changes in ISS of 16-24 points. Direct comparison of groups of patients scored with these two revisions of the AIS is inappropriate, particularly in those with abdomen region injury. 相似文献
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28.
SP Greene DM Soucy WC Song AE Barber FN Hagedorn HP Illner GT Shires 《Canadian Metallurgical Quarterly》1998,124(3):568-574
BACKGROUND: Attempts to modify traditional fluid resuscitation have been based on animal models that evaluate several variables including anesthesia. This study presents the effects of early saline resuscitation from severe uncontrolled hemorrhage unanesthetized rats. METHODS: Sixty-three female Sprague-Dawley rats were equally divided into three groups: group A, nonresuscitated; and groups B and C, resuscitated ;with isotonic saline (40 and 80 mL/kg, respectively). Hemodynamics, blood loss, survival time, and mortality were recorded for 360 minutes after the hemorrhage, which was initiated by 75% resection of the tail. RESULTS: In group C, 80 mL/kg of saline significantly lowered mortality (24% vs 76% and 71% for groups A and B, respectively) with concomitant increases in mean survival time (241 +/- 103 min vs 146 +/- 108 and 175 +/- 92 min for groups A and B, respectively). There were no statistically significant differences in blood loss, hematocrit, or hemodynamic parameters among the groups. CONCLUSIONS: Early and adequate isotonic saline resuscitation of unanesthetized rats improved outcome despite continuing hemorrhage. The significantly lower mortality rate and increased survival time were not a result of transiently improved arterial pressure and did not correlate with blood loss. No significant bleeding increases were noted in the resuscitated groups. 相似文献
29.
The antioxidant properties of butein, isolated from Dalbergia odorifera T. Chen, were investigated in this study. Butein inhibited iron-induced lipid peroxidation in rat brain homogenate in a concentration-dependent manner with an IC50, 3.3+/-0.4 microM. It was as potent as alpha-tocopherol in reducing the stable free radical diphenyl-2-picrylhydrazyl (DPPH) with an IC0.200, 9.2+/-1.8 microM. It also inhibited the activity of xanthine oxidase with an IC50, 5.9+/-0.3 microM. Besides, butein scavenged the peroxyl radical derived from 2,2-azobis(2-amidinopropane) dihydrochloride (AAPH) in aqueous phase, but not that from 2,2-azobis(2, 4-dimethylvaleronitrile) (AMVN) in hexane. Furthermore, butein inhibited copper-catalyzed oxidation of human low-density lipoprotein (LDL), as measured by conjugated dienes and thiobarbituric acid-reactive substance (TBARS) formations, and electrophoretic mobility in a concentration-dependent manner. Spectral analysis revealed that butein was a chelator of ferrous and copper ions. It is proposed that butein serves as a powerful antioxidant against lipid and LDL peroxidation by its versatile free radical scavenging actions and metal ion chelation. 相似文献
30.
JR Hibbs JM Douglas FN Judson WL McGill CA Rietmeijer EN Janoff 《Canadian Metallurgical Quarterly》1997,25(2):195-199
The hemagglutinating virus of Japan (HVJ)-liposome method involves the entrapment of DNA and nuclear protein within liposomes and the use of HVJ to enhance liposome fusion with cell membranes. This method has been used successfully for in vivo gene transfer to various types of tissue. In this study, we investigated whether this method transfers genes effectively to normal and malignantly transformed keratinocytes in vivo. We applied HVJ-liposome complex (HLC) containing the beta-galactosidase gene to the tape-stripped skin of hairless rats and detected the enzyme activity in the keratinocytes of the treated skin. Comparison of this method with the naked DNA injection method, which was shown recently to be useful for in vivo gene transfer to keratinocytes, demonstrated that the transfer efficiency of the latter was about 5 times higher than that of the former. We assessed the efficacy of the HVJ-liposome method for gene transfer to transformed keratinocytes by examining the effect of HLC containing the herpes simplex virus thymidine kinase gene on the growth of mouse squamous cell carcinomas. Local injection of HLC into the tumors followed by administration of ganciclovir to mice resulted in tumor growth inhibition. These results indicate that the HVJ-liposome method is suitable for in vivo gene transfer to keratinocytes; also that this method may prove a good tool for basic research into keratinocyte biology and future keratinocyte gene therapy. 相似文献