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41.
Dichlorvos vapor was applied weekly from dichlorvos-impregnated resin pellets into 42·5 m3 (1500 ft3) chambers. The chambers contained insect-free flour packaged in cotton sheeting, and in multiwall paper bags stacked at various distances from similar bags of infested flour. The dichlorvos concentration attained in the chambers from the weekly application of vapor was about 3 μg/1. After 5 months of storage, the number of insects found in the flour indicated that the dichlorvos applications retarded the infestation of flour in cotton bags and prevented the infestation of flour in the multiwall paper bags. Chemical analysis showed that dichlorvos residues were less than 0·1 ppm in the flour and, in general, less than 1·1 μg/dm2 (10 μg/ft2) on the packaging materials.  相似文献   
42.
Directed assembly of nano-particles by charged patterns on an insulator surface is a method that has been applied before, but the creation of the charged patterns was a time consuming process in previous work. Here a scanning electron microscope (SEM) is used to speed up the charging process. The main challenges do not lie in focusing the electron beam but in storing the charge in the insulator in a highly localized way. The present paper shows the first promising results of directing nano-particles to predefined charge patterns on insulators, where the charge is created with a finely focused electron beam. The nano-particles (palladium) are created in an Ar atmosphere with a glowing wire generator (GWG). A narrow size interval of charged particles is selected by a mobility analyzer. From gas suspension they are deposited onto the charge patterns.  相似文献   
43.
用于大面积显示的低成本纳米管场发射显示器   总被引:2,自引:0,他引:2  
我们验证了一个显示视频图像的阴极阵列,它基于6in对角线、QVGA分辨率的碳纳米管,采用了简单的低成本器件结构。该纳米管是利用选择性化学汽相沉积法生长在特定位置上的,对净化阴极具有良好的可控性。该器件结构只需要三个低分辩率的掩膜工序,开关电压为50V。此外,我们的器件设计为较长的显示寿命创造了条件。在一个较小的全熔接密封的试验显示器上,我们已经记录了超过3000小时的寿命,而电流仅下降了20%。  相似文献   
44.
The effect of the gonadotropin-releasing hormone (LRH) and thyrotropin-releasing hormone (TRH) on the blood levels of LH, FSH and TSH, and LHbeta- and alpha-subunit have been studied in 4 normal subjects during the first 20 min after administration of these releasing hormones. Increases in serum immunoreactive LH, LHbeta and alpha-subunit were seen in all subjects after LRH (100 mug iv) but in all subjects the rise in LH was preceded by a rise in alpha-subunit. All subjects showed an increase in TSH and 3 of the 4 subjects a rise in alpha-subunit after TRH (200 mug) but the alpha-subunit responses were smaller and less consistent than after LRH. Levels of LHbeta remained unchanged after TRH. The results demonstrate that the immunoreactive alpha-subunit of the pituitary glycoprotein hormones can be released independently of the intact hormones and that release occurs in response to the same releasing hormones, LRH and TRH, that release the intact hormones.  相似文献   
45.
The present study was designed to examine recall and rehearsal in short-term memory among children with insulin-dependent diabetes mellitus (IDDM). Children with onset of IDDM before age 5 years, children with onset after 5 years, and children without IDDM were administered a measure of short-term memory that provides information about rehearsal as well as level of recall. Children with later onset of diabetes and children without IDDM were expected to recall more words and use more effective rehearsal strategies than children with early onset of diabetes. Results indicate that children diagnosed with IDDM early in life used similar rehearsal strategies but recalled fewer words than children with later onset of diabetes and children without IDDM. In addition, results provide evidence that children who are in poor control of their diabetes did not use strategies designed to increase recall as often, or as well as, children in better control of their diabetes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
46.
Monophosphoryl lipid A (MLA), a derivative of the minimal substructure of lipopolysaccharide (lipid A) possesses immunomodulatory activity of the parent lipid A yet enjoys reduced toxicity. It has previously been reported that pretreatment with MLA reduces myocardial infarct size and stunning in dogs following ischemia and reperfusion. The aim of this study was to evaluate the ability of monophosphoryl lipid A (MLA) to preserve global cardiac function and peripheral hemodynamics in a rabbit model of prolonged regional ischemia (90 min), and reperfusion (6 h). An evaluation of potential mechanisms by which MLA may preserve cardiac function was also undertaken. Single dose pretreatment with MLA (35 micrograms/kg i.v.) 24 h prior to ischemia resulted in significant improvement in left ventricular developed pressure, dP/dt, rate-pressure product and mean arterial pressure during reperfusion (P < 0.05 v control). Although in this model of prolonged ischemia MLA pretreatment did not reduce infarct size (54.5 +/- 11.4% in control v 63.3 +/- 8.3% in MLA, P = N.S.), evaluation of myocardial adenylate and adenosine catabolite pools at the end of ischemia indicated a preservation of ATP and ADP and a decreased production of downstream adenosine catabolites including inosine, xanthine and uric acid. Adenosine kinase, but not 5'-nucleotidase (5'-NTase) or adenosine deaminase activity determined following reperfusion was 76% and 60% higher (P < 0.05) in non-risk and post-ischemic myocardium of MLA pretreated rabbits compared with controls. Although there was a trend toward lower tissue myeloperoxidase activity in post-ischemic myocardium from treated rabbits, the results were not significantly different from control animals. These results suggest that a 24-h pretreatment with MLA, without further treatment during ischemia or reperfusion was associated with: (1) preservation of global myocardial function during reperfusion; (2) preservation of myocardial high energy adenylates and reduced formation of adenosine catabolites during ischemia; (3) elevated myocardial adenosine kinase activity. Increased recycling of adenosine to phosphorylated nucleotides may result from MLA's affect on adenosine kinase, which could explain the drugs effect on adenylate and adenosine metabolite pools.  相似文献   
47.
48.
All boiling water reactor (BWR) degraded core experiments performed prior to CORA-33 were conducted under ‘wet’ core degradation conditions, in which water remains within the core and continuous steaming feeds metal-steam oxidation reactions on the in-core metallic surfaces. However, one dominant set of accident scenarios would occur with reduced metal oxidation under ‘dry’ core degradation conditions and, prior to CORA-33, this set had been neglected experimentally. The CORA-33 experiment was designed specifically to address this dominant set of BWR ‘dry’ core severe accident scenarios and to resolve partially phenomenological uncertainties concerning the behavior of relocating metallic melts that drain into the lower regions of a ‘dry’ BWR core (the ex-reactor experiments at Sandia National Laboratories will further address these uncertainties). CORA-33 was conducted on 1 October 1992, in the CORA test facility at Karlsruhe. A review of the CORA-33 data indicates that the objectives were achieved; i.e. core degradation occurred at a core heat-up rate (characterized by the absence of any temperature escalation caused by oxidation) and a test section axial temperature profile (at incipient structural melting) that are prototypic of full-core nuclear power plant simulations under ‘dry’ core conditions. Simulations of the CORA-33 test at Oak Ridge National Laboratory (ORNL) have required the modification of existing control blade-canister materials interaction models to include the eutectic melting of the stainless steel-zircaloy interaction products and the heat of mixing of stainless steel and zircaloy. The timing and location of canister failure and melt intrusion into the fuel assembly appear to be adequately simulated by the ORNL models. This paper will present the results of the post-test analyses carried out at ORNL based on the experimental data and the post-test examination of the test bundle at Karlsruhe. The implications of these results with respect to degraded core modelling and the associated safety issues are also discussed.  相似文献   
49.
Papillary renal carcinomas are a cytogenetically unique subset of renal carcinomas that have been reported to be clinically less aggressive. We have examined 19 papillary tumors for immunohistochemical expression of the epidermal growth factor receptor (EGF-R) and its ligand, transforming growth factor alpha (TGF-alpha). EGF-R and TGF-alpha expression was also studied in 149 nonpapillary tumors and 7 mixed papillary/solid tumors. EGF-R and TGF-alpha expression were compared to histology, stage, metastatic behavior, and survival. Formalin-fixed, paraffin-embedded nephrectomy specimens collected between 1977 and 1986 were stained with antibodies to EGF-R and TGF-alpha. Patients with papillary tumors were found to present with earlier stage disease and had significantly longer survival. Papillary tumors had a significantly lower rate of EGF-R positivity than solid pattern tumors (21% versus 73%, P < 0.001). Intermediate or strong cell membrane immunoreactivity for EGF-R was associated with high tumor grade and poor disease-specific survival. EGF-R positivity in the primary tumor was associated with the presence of metastatic disease and with metastatic spread to lung versus bone. Tumor parenchymal TGF-alpha staining was present in 50% of the cases and was not associated with stage or grade. Unrelated to tumor parenchymal TGF staining, tumor vessels stained for TGF-alpha in 56% of the cases. Vessel TGF-alpha staining was absent in papillary tumors (P < 0.001). The improved clinical behavior of papillary tumors as compared to nonpapillary renal tumors may be related, in part, to their relatively lower levels of EGF-R expression.  相似文献   
50.
The EORTC Core Quality of Life questionnaire (EORTC QLQ-C30) is designed to measure cancer patients' physical, psychological and social functions. The questionnaire is composed of multi-item scales and single items. 247 patients completed the EORTC QLQ-C30 before palliative radiotherapy and 181 after palliative radiotherapy. The questionnaire was well accepted with a high completion rate in the present patient population consisting of advanced cancer patients with short life expectancy. In addition, the questionnaire was found to be useful to detect the effect of palliative radiotherapy over time. The scale reliability was excellent for all scales except the role functioning scale. Excellent criterion validity was found for the emotional functioning scale where it was correlated with GHQ-20. Performance of the questionnaire was improved after the second evaluation as compared with the first. The present study shows that the EORTC QLQ-C30 is found to be practical and valid in measuring quality of life in patients with advanced disease.  相似文献   
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