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271.
We established in culture two colony clones of rMTC 44-2 cells, rMTC 44-2B and 44-2C which secrete substantially greater quantities of neurotensin (NT) than the parent cell line. We describe here the effects of the synthetic glucocorticoid, dexamethasone, on NT and cAMP release. Medium and intracellular levels of NT and cAMP were measured by specific RIAs. Long-term release experiments were performed in Dulbecco's Modified Eagle's Medium supplemented with 15% horse serum (DMEM). Short-term release experiments were performed in Krebs-Ringer-bicarbonate-glucose buffer (KRBG) supplemented with 1.0 mm Ca2+. Dexamethasone stimulated NT release and increased intracellular NT levels. The ED50 values for stimulation of NT release following 24 or 48 h incubation of cells in DMEM with dexamethasone were 5 X 10(-9) and 7 X 10(-9) M, respectively. Dexamethasone markedly enhanced intracellular levels of NT in rMTC 44-2 cells while it decreased cell growth. Cells pretreated with dexamethasone for 48 h released greater amounts of NT in response to Ca2+ (1.0 mM) with or without K+ (50 mM) or NE (10(-6) M) following a 10 min incubation with these substances in KRBG. This experimental paradigm was also used to measure the efflux of cAMP following a brief (10 min) exposure of cells to NE. We conclude that the rMTC 44-2B and 44-2C cells are useful tools for studying the effects of dexamethasone on the regulation of cell growth, as well as the secretion of NT and cAMP.  相似文献   
272.
The network intrusion detection techniques are important to prevent our systems and networks from malicious behaviors. However, traditional network intrusion prevention such as firewalls, user authentication and data encryption have failed to completely protect networks and systems from the increasing and sophisticated attacks and malwares. In this paper, we propose a new hybrid intrusion detection system by using intelligent dynamic swarm based rough set (IDS-RS) for feature selection and simplified swarm optimization for intrusion data classification. IDS-RS is proposed to select the most relevant features that can represent the pattern of the network traffic. In order to improve the performance of SSO classifier, a new weighted local search (WLS) strategy incorporated in SSO is proposed. The purpose of this new local search strategy is to discover the better solution from the neighborhood of the current solution produced by SSO. The performance of the proposed hybrid system on KDDCup 99 dataset has been evaluated by comparing it with the standard particle swarm optimization (PSO) and two other most popular benchmark classifiers. The testing results showed that the proposed hybrid system can achieve higher classification accuracy than others with 93.3% and it can be one of the competitive classifier for the intrusion detection system.  相似文献   
273.

Image inpainting is a common technique for repairing image regions that are scratched or damaged. This process involves reconstructing damaged parts and filling-in regions in which data/colour information is missing. There are many potential applications for image inpainting, such as repairing old images, repairing scratched images, removing unwanted objects, and filling-in missing areas. This paper develops an exemplar-based algorithm, one of the most important and popular image inpainting techniques, to fill-in missing regions caused by removing unwanted objects, image compression, scratches, or image transformation via the Internet. The proposed algorithm includes two phases of searching to select the best-matching information. In the first phase, the searching mechanism uses the entire image to find and select the most similar patches using the Euclidean distance. The second phase measures the distance between the location of the selected patches and the location of the patch to be filled. The performance of the proposed approach is evaluated through comprehensive experiments on several well-known images used in this area of research. The experimental results demonstrate the superior performance of the proposed approach over some state-of-the-art approaches in terms of quality in terms of both objective (using the peak signal-to-noise ratio (PSNR) as well as the structural similarity index method (SSIM)) and subjective (i.e., visual) measures.

  相似文献   
274.
The various leukemias in Hokkaido for the past 20 years are analysed in its change of the mortality rate, the type of leukemia, and the clinical picture. The observation years are divided into 4 periods: I (1951-1957), II (1958-1962), III (1963-1967), IV (1968-1972). 1. The adjusted mortality rate of leukemia shows a rising tendency through these periods: I (1.7), II (3.0), III (3.5), IV (3.6). 2. The adjusted age-specific mortality rate of leukemia in period II, III, and IV, show a remarkable increase in all age brackets compared with period I, especially in older age brackets. The rate of the "60-69 years old" bracket gradually rises as I (3.1), II (4.8), III (5.9), IV (7.2). The rate of the "over 70 years old" bracket is I (1.3), II (1.8), III (5.0), IV (9.3). It is characteristic that these brackets has the highest mortality rate in period IV. 3. Some comparisons between period I and IV are described as follows: (1). Monocytic leukemia had decreased from 10.6% (I) to 1.4% (IV) and chronic myelogenous leukemia has slightly increased in period IV. (2). In acute type, the cases of aleukemic leukemia tends to increase in period IV and its initial symptoms changes into mild gradually. (3). In chronic type in period IV, splenomagaly is common in the initial symptom and while blood cell counts in these cases are above 10 x 10(4)/cmm.  相似文献   
275.
276.
INTRODUCTION: New possibilities for transcatheter treatment of the cardiovascular system are guaranteed with the improvement of materials and the availability of new devices. Nevertheless, a rationalization of the potential activity in this sector seems to be necessary, and it could arise through the presence of Catheterization Laboratories "open" to diagnostic procedures and therapy that are not confined to the coronary system. This clinical study reports the experiences and results of our work in this field. MATERIALS AND METHODS: During the period from May 1995 to May 1997, our laboratory performed 205 diagnostic procedures that did not involve the coronary system. Based on this diagnostic work, there emerged 91 cases with an indication for transcatheter intervention, which was subsequently performed at our laboratory. There were 68 peripheral angioplasty procedures on the iliofemoral axis, 2 angioplasties of the subclavian artery, 8 of the renal artery, 2 procedures involving the treatment of A-V fistulas, one case of femoral pseudoaneurysm treatment and 10 cases of transcutaneous pericardiotomy performed with a balloon catheter. All the procedures were performed by our laboratory staff using materials that are normally at our disposal. RESULTS: Successful results were obtained in 65 out of the 68 peripheral angioplasty procedures and in all of the 8 renal and 2 subclavian angioplasties. The positioning of the endoprosthesis for the closure of the A/V fistula was effective in one of the two cases. The transcatheter treatment of the femoral pseudoaneurysm was successful. In all cases where a pericardiotomy was performed with a balloon catheter, there was no reoccurrence of cardiac tamponade during the follow-up period. No complications were noted as a result of any of the procedures. CONCLUSIONS: Our experience documents how it is possible to increase the diagnostic and therapeutic options in a Catheterization Laboratory. However, willingness on the part of the staff to update their skills continually and collaborate with other specialists is necessary in order to maintain optimal operative standards.  相似文献   
277.
A new-technology cigarette has been developed. While the new cigarette burns some tobacco, it does not use tobacco as the fuel to sustain combustion and provide heat to the cigarette. Rather, the new cigarette primarily heats tobacco thereby reducing products of smoke formation mechanisms such as tobacco combustion, tobacco pyrolysis and pyrosynthesis. The mainstream smoke composition from a cigarette based on the new design (TOB-HT) has been characterized in comparative chemical testing with two reference cigarettes using the FTC puffing regimen. Thermal properties, UV absorption characteristics, elemental composition and materials balance studies all suggest a simplified smoke aerosol. Twenty-five smoke constituents ("target compounds") identified by the scientific community as compounds that may contribute to the diseases statistically associated with smoking have also been measured. Mainstream smoke concentrations of most target compounds are significantly lower with the TOB-HT cigarette when compared with reference cigarettes in the ultra-light "tar" and light "tar" categories. Taken together, chemical analysis results suggest simplified TOB-HT smoke chemistry with marked reductions in specific chemicals reported to be biologically active.  相似文献   
278.
The present investigation was carried out for the analysis of hydrocarbon compounds of Tunisian Meski olives. The hydrocarbon fraction of the oils was found to contain twelve n‐alkanes (C22–C36) and squalene. Results from the quantitative characterisation of the oils revealed that squalene was the most abundant hydrocarbon compound, at all development stages of Meski olive, accounting for more 92% of total hydrocarbons. Pentacosane (C25), heptacosane (C27) and tricosane (C23) represented the major compounds of n‐alkanes. The highest accumulation of n‐alkanes and squalene was observed at early stages of olive development [before 21st week after the flowering date (WAFD)]. The greatest decrease of these components occurred between 21st and 26th WAFD of the olives. At complete maturity of the fruit, the level of squalene and total n‐alkanes was 126.52 and 9.13 mg per 100 g oil, respectively. Hence, the content of n‐alkanes and squalene was remarkably influenced by the ripeness process of olive.  相似文献   
279.
BACKGROUND: Many experts have suggested that blunt splenic trauma in patients older than 55 years should not be managed by observation because of supposed increased fragility of the spleen and decreased physiologic reserve in elderly patients. We sought to determine the outcome of nonoperative management of blunt splenic trauma in patients older than 55 years. METHODS: For the years 1994 through 1996, data for patients with splenic injury older than 55 years from seven trauma centers in a single state were reviewed. RESULTS: Blunt splenic trauma occurred in 41 patients older than 55 years. Eight patients were excluded from further analysis because of death from massive associated injuries within 24 hours of admission. The remaining 33 patients (mean age, 72+/-10 years) were divided into two groups: immediate exploration (10 patients) and observation (23 patients). Observation of blunt splenic injury failed in 4 of 23 patients (17%). No patient deaths were related to the method of management of the splenic injury. CONCLUSIONS: Observation of the elderly patient with blunt splenic trauma has an acceptable failure rate of 17%.  相似文献   
280.
This paper reviews the theory and evaluation of ultraprecision-machined surfaces. Carbide and single crystalline diamond tools were used to machine brittle, ductile and metal matrix composites in macro and micro scales. Data for ductile mode micromachining of brittle materials (silicon, Al2O3, SiC) and ductile materials (Cu-Be, Cu-Zn, Al-Si) were presented and compared. Models for surface finish were presented and evaluated with experimental data. The surface finish and surface integrity were characterized with scanning electron microscopy, scanning probe microscopy, and profilometry techniques. The models agreed with experimental data for ductile materials machined with a diamond tool in macro scale, but deviated from the data at micro scale because of the effect of the material microstructure. The drawbacks of the models were highlighted, i.e., they should include the crystalline orientation of the material and the effect of microstructure on surface finish.  相似文献   
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