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131.
Absorbable stapling devices have been described by several groups for the creation of continent urinary diversions. Experience with these devices in the creation of the LeBag ileocecal orthotopic pouch is described. Use of the staplers simplifies pouch construction and yields functional results similar to hand-sewn reservoirs. 相似文献
132.
WJ Cho EK Kim MJ Park SU Choi CO Lee SH Cheon BG Choi BH Chung 《Canadian Metallurgical Quarterly》1998,6(12):2449-2458
In this study a series of 3-arylisoquinoline derivatives were synthesized and cytotoxicity against human melanoma tumor cell evaluated, and a three dimensional quantitative structure-activity relationship was investigated using the comparative molecular field analysis (CoMFA). The results suggested that the electrostatic, steric and hydrophobic factors of 3-arylisoquinolines were strongly correlated with the antitumor activity. Considerable predictive ability (cross-validated r2 as high as 0.721) was obtained through CoMFA. 相似文献
133.
134.
M Wolfgang P Lauer HS Park L Brossay J Hébert M Koomey 《Canadian Metallurgical Quarterly》1998,29(1):321-330
Neisseria gonorrhoeae, the Gram-negative aetiological agent of gonorrhoeae, is one of many mucosal pathogens of man that expresses competence for natural transformation. Expression of this phenotype by gonococci appears to rely on the expression of type IV pili (Tfp), but the mechanistic basis for this relationship remains unknown. During studies of gonococcal pilus biogenesis, a homologue of the PilT family of proteins, required for Tfp-dependent twitching motility in Pseudomonas aeruginosa and social gliding motility in Myxococcus xanthus, was discovered. Like the findings in these other species, we show here that gonococcal PilT mutants constructed in vitro no longer display twitching motility. In addition, we demonstrate that they have concurrently lost the ability to undergo natural transformation, despite the expression of structurally and morphologically normal Tpf. These results were confirmed by the findings that two classes of spontaneous mutants that failed to express twitching motility and transformability carried mutations in PilT. Piliated PilT mutants and a panel of pilus assembly mutants were found to be deficient in sequence-specific DNA uptake into the cell, the earliest demonstrable step in neisserial competence. The PilT-deficient strains represent the first genetically defined mutants that are defective in DNA uptake but retain Tfp expression. 相似文献
135.
A database of 209 chemicals tested for induction of forward mutations at the heterozygous thymidine kinase (TK +/-) locus in L5178Y mouse lymphoma cells was analyzed for structure-activity relationships using the MultiCASE expert system. Consistent with evidence of several contributing biological mechanisms, these studies suggest that such mutations may occur by more than one mechanism. As might be expected, there was evidence for a component involving direct electrophilic attack on the cellular DNA, in a manner previously established as causative in the induction of mutations in Salmonella. In addition, however, there was also strong evidence for another mechanism or mechanisms involving chromosome missegregation, cellular toxicity or an alternate site of action, such as the microtubules. 相似文献
136.
137.
138.
VJ Paul Y Seo KW Cho JR Rho J Shin PR Bergquist 《Canadian Metallurgical Quarterly》1997,60(11):1115-1120
Ten sesquiterpenoids, including seven new ones, have been isolated from an undescribed sponge of the genus Dysidea. Compounds 1-8 are sesquiterpenoids of the drimane class, while 9 and 10 are 12-norsesquiterpenoids of the same structural class. The structures of novel compounds have been determined by combined spectroscopic methods. These compounds exhibited moderate antimicrobial and enzyme inhibitory (Na+/K(+)-ATPase and PLA2) activities. 相似文献
139.
This paper presents a 2D to 3D conversion scheme to generate a 3D human model using a single depth image with several color
images. In building a complete 3D model, no prior knowledge such as a pre-computed scene structure and photometric and geometric
calibrations is required since the depth camera can directly acquire the calibrated geometric and color information in real
time. The proposed method deals with a self-occlusion problem which often occurs in images captured by a monocular camera.
When an image is obtained from a fixed view, it may not have data for a certain part of an object due to occlusion. The proposed
method consists of following steps to resolve this problem. First, the noise in a depth image is reduced by using a series
of image processing techniques. Second, a 3D mesh surface is constructed using the proposed depth image-based modeling method.
Third, the occlusion problem is resolved by removing the unwanted triangles in the occlusion region and filling the corresponding
hole. Finally, textures are extracted and mapped to the 3D surface of the model to provide photo-realistic appearance. Comparison
results with the related work demonstrate the efficiency of our method in terms of visual quality and computation time. It
can be utilized in creating 3D human models in many 3D applications. 相似文献
140.