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91.
From 1970 to 1992 a total of 63 patients underwent operation for ampullary tumor: 40 pancreatoduodenectomies (PDs), 3 total PDs, 8 ampullectomies, and 12 bypass or exploratory laparotomies. The resectability rate was 68%. There were 9 benign tumors, 1 anaplastic tumor, and 53 adenocarcinomas. According to Martin's classification, there were 7 stage I, 11 stage II, 14 stage III, and 21 stage IV tumors. All patients with stage I, II, and III tumors underwent resection. Patients with stage IV tumors had either resection (n = 11) or bypass (n = 10). The mean duration of hospital stay was 20.6 days. Operative mortality was 12.7% for the whole series and 7.5% after PD (2.5% for the last 10 years). Overall survival was 40% at 5 years (85% for stage I, 65% for stage II, 44% for stage III, and 8% for stage IV). Survival was better for stages I, II, and III after PD than after ampullectomy. For stage IV patients survival was 70% after PD versus 20% after bypass at 1 year and 25% versus 0% after 2 years. In our opinion, PD should be proposed even for benign lesions because two of our patients had to undergo repeat operation (PD) 4 and 22 years later, respectively, for stage IV disease. PD is our choice for all tumors of the ampulla. 相似文献
92.
E. K. Ylh?inen M. R. Nunes A. J. Silvestre O. C. Monteiro 《Journal of Materials Science》2012,47(10):4305-4312
This article reports on a new and swift hydrothermal chemical route to prepare titanate nanostructures (TNS) avoiding the
use of crystalline TiO2 as starting material. The synthesis approach uses a commercial solution of TiCl3 as titanium source to prepare an amorphous precursor, circumventing the use of hazardous chemical compounds. The influence
of the reaction temperature and dwell autoclave time on the structure and morphology of the synthesised materials was studied.
Homogeneous titanate nanotubes with a high length/diameter aspect ratio were synthesised at 160 °C and 24 h. A band gap of
3.06 ± 0.03 eV was determined for the TNS samples prepared in these experimental conditions. This value is red shifted by
0.14 eV compared to the band gap value usually reported for the TiO2
anatase. Moreover, such samples show better adsorption capacity and photocatalytic performance on the dye rhodamine 6G (R6G) photodegradation
process than TiO2 nanoparticles. A 98% reduction of the R6G concentration was achieved after 45 min of irradiation of a 10 ppm dye aqueous
solution and 1 g L−1 of TNS catalyst. 相似文献
93.
H凹陷三叠系小泉沟群地震相分析 总被引:1,自引:0,他引:1
在中国西部许多陆相盆地中,发育了多种各样的砂岩储集体,这些砂体在不同的沉积环境、不同的相带中有规律地分布着。文中对西部某盆地H凹陷三叠系小泉沟群地震相和沉积相进行了较详细的研究;分析了该组的岩性特征、地震相特征和剖面沉积相特征,指出了各种沉积相中的主要砂体类型及有利的含油气相带。 相似文献
94.
JK Han HJ Jang BI Choi SH Kim TK Kim HJ Won YI Kim SY Cho 《Canadian Metallurgical Quarterly》1999,34(2):99-108
RATIONALE AND OBJECTIVES: The authors sought to correlate the radiologic findings of hepatobiliary fascioliasis with pathologic features. METHODS: Serial ultrasound, computed tomography (CT), and magnetic resonance findings in seven rabbits with experimentally induced fascioliasis were obtained every other week. Direct cholangiogram was also obtained after the rabbits were killed. Radiology-pathology correlation was done in specimens. RESULTS: In the parenchymal phase (an acute phase of parenchymal invasion of a larva), CT showed subcapsular clustered areas of low attenuation. Magnetic resonance appearance was similar in shape but better than CT in characterizing the hemorrhagic nature of the lesion. Ultrasound findings were nonspecific in this phase. In the ductal phase (a stationary phase after residing in the bile duct), CT showed dilatation of central ducts with symmetric periportal hypoattenuation (periportal tracking). Magnetic resonance could not depict mild ductal dilatation. Ultrasound was most valuable in demonstrating the moving worm within the dilated duct. Pathologically, the hepatic parenchymal lesions consisted of a cluster of eosinophilic granulomas with hemorrhagic change (migratory tract of the flukes). Ductal changes were observed predominantly in the central bile ducts. Periportal lymphangiectasia was also noted. CONCLUSIONS: Computed tomography or magnetic resonance can demonstrate the characteristic evolutionary pattern of fascioliasis that reflects the unique life cycle of Fasciola hepatica. The role of ultrasound, although limited in the parenchymal phase, was most useful in the ductal phase in that it demonstrated the moving worms themselves. 相似文献
95.
SH Wong Y Xu T Zhang G Griffiths SL Lowe VN Subramaniam KT Seow W Hong 《Canadian Metallurgical Quarterly》1999,10(1):119-134
Syntaxin 1, synaptobrevins or vesicle-associated membrane proteins, and the synaptosome-associated protein of 25 kDa (SNAP-25) are key molecules involved in the docking and fusion of synaptic vesicles with the presynaptic membrane. We report here the molecular, cell biological, and biochemical characterization of a 32-kDa protein homologous to both SNAP-25 (20% amino acid sequence identity) and the recently identified SNAP-23 (19% amino acid sequence identity). Northern blot analysis shows that the mRNA for this protein is widely expressed. Polyclonal antibodies against this protein detect a 32-kDa protein present in both cytosol and membrane fractions. The membrane-bound form of this protein is revealed to be primarily localized to the Golgi apparatus by indirect immunofluorescence microscopy, a finding that is further established by electron microscopy immunogold labeling showing that this protein is present in tubular-vesicular structures of the Golgi apparatus. Biochemical characterizations establish that this protein behaves like a SNAP receptor and is thus named Golgi SNARE of 32 kDa (GS32). GS32 in the Golgi extract is preferentially retained by the immobilized GST-syntaxin 6 fusion protein. The coimmunoprecipitation of syntaxin 6 but not syntaxin 5 or GS28 from the Golgi extract by antibodies against GS32 further sustains the preferential interaction of GS32 with Golgi syntaxin 6. 相似文献
96.
97.
A general regeneration, identification, and optimization (RO) protocol for Biacore systems was developed. The RO protocol uses six multi-ingredient stock solutions that represent the six most common chemical properties employed as regeneration agents. The regeneration effect of different regeneration cocktails of these six stock solutions were tested iteratively until a satisfactory result was obtained. The RO protocol was designed with an ease-of-use and multivariate approach. The RO protocol was tested on 13 different antibody-antigen systems. For 10 of these, only the first screening session was tested. For 9 of the 13 systems, the RO-protocol screening session identified cocktails that removed more than 90% of the bound analyte in a 30 s pulse. For 5 systems, the RO protocol identified cocktails that regenerated the surface completely and that were more gentle than previously used regeneration conditions. Furthermore, the regeneration optimization results can be interpreted as a characterization of the interacting molecules. The relevance of testing cocktails was justified by the fact that at least one cocktail was significantly better than all diluted stock solutions for all tested model systems. By using the multivariate approach, the risk of missing relevant combinations of stock solutions was minimized. This resulted in an unexpected discovery of excellent properties of EDTA as an additive in regeneration cocktails containing chaotropic agents and ions in high concentration. 相似文献
98.
99.
100.
This study investigated changes in the marginal adaptation and surface morphology of Ketac-Silver and Chelon-Silver glass-current cements over time. Dispersalloy amalgam was used as a control. Contralateral pairs of carious primary molars were restored with the test materials and amalgam. Clinical evaluations were scheduled at 12, 18, and 24 months after placement. Gold-plated replicas of the restorations were observed with scanning electron microscopy. Fractures and cracks in the surface of the Dispersalloy and Chelon-Silver increased the surface roughness; however, the damage was superficial and self-limiting in the Dispersalloy restorations, while in Chelon-Silver the fractures caused the material to break down in layers. A substantial quantity of pores, usually smaller than 50 microns in diameter, were observed throughout the surface of the Chelon-Silver restorations. The pores in the surface of Ketac-Silver were fewer and smaller. The incidence of cavomarginal breakdown increased with time. Chelon-Silver restorations had a higher rate of cavomarginal breakdown than did Ketac-Silver and Dispersalloy restorations up to 18 months. However, there was no statistically significant difference in the marginal adaptation of the three groups at 24 months. 相似文献