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241.
PURPOSE: Our goal was to characterize the radiologic features of liver metastases from colon cancer with intrahepatic bile duct (IHBD) dilatation. METHOD: Radiologic findings of liver metastases from colon cancer with IHBD dilatation of four patients were compared with pathologic findings. RESULTS: The cause of bile duct dilatation in all cases was due to papillary tumor growth in the bile duct. In two patients, intra-bile duct tumor growth (IBDTG) was observed on imaging. In the other two patients, IBDTG was not observed, but a nontapered abrupt obstruction of a dilated bile duct was seen, corresponding to the microscopically proven papillary tumor growth in the ductal lumen. In three patients who underwent an extensive hepatic resection, there has been no recurrence. In one patient who had a nonanatomic limited resection, a recurrence was seen 1 year after surgery. CONCLUSION: When liver tumor with IBDTG is suspected on imaging, liver metastases should be considered in the differential diagnosis besides hepatocellular carcinoma or cholangiocellular carcinoma. Careful preoperative assessment for IBDTG by imaging is essential to determine the extent of surgical resection.  相似文献   
242.
In relational databases, a query can be formulated in terms of a relational algebra expression using projection, selection, restriction, cross product and union. In this paper, we consider a problem, called the membership problem, of determining whether a given dependency d is valid in a given relational expression E over a given database scheme R that is, whether every instance of the view scheme defined by E satisfies d (assuming that the underlying constraints in R are always satisfied).Consider the case where each relation scheme in R is associated with functional dependencies (FDs) as constraints, and d is an FD. Then the complement of the membership problem is NP-complete. However, if E contains no union, then the membership problem can be solved in polynomial time. Furthermore, if E contains neither a union nor a projection, then we can construct in polynomial time a cover for valid FDs in E, that is, a set of FDs which implies every valid FD in E.Consider the case where each relation scheme in R is associated with multivalued dependencies (MVDs) as well as FDs, and d is an FD or an MVD. Even if E consists of selections and cross products only, the membership problem is NP-hard. However, if E contains no union, and each relation scheme name in R occurs in E at most once, then the membership problem can be solved in polynomial time. As a corollary of this result, it can be determined in polynomial time whether a given FD or MVD is valid in R1???Rs, where R1,…,Rs are relation schemes with FDs and MVDs, and Ri?Rj is the natural join of Ri and Rj.  相似文献   
243.
The free volume fraction (vf) defined by Simha and Boyer was measured for metaphosphate and mixed metaphosphate glasses (MO · P2O5; M=Ca, Sr, Ba, Mg, Zn). The glasses were classified into groups (1) in which M =Ca, Sr, Ba (Vf≠0.1) and (2) in which M =Mg, Zn (vf∼ 0.l). The Vf values of mixed glasses containing cations from both groups varied. Thus, these glasses are not in an iso-free-volume state at the glass transition temperature.  相似文献   
244.
A method which monitors the changes in electrical resistance in CFGFRP (carbon-fiber–glass-fiber-reinforced plastics) composites was found to be a promising technique for foreseeing fractures and preventing fatal ones. CFGFRP composites containing two types of carbon fibers along with 31.6 vol% glass fibers were used. U-shaped copper electrodes were attached to both ends of the CFGFRP composites, using a conductive adhesive agent, and electrical resistance was measured via a two-thermal dc method. A strain gauge was attached onto a specimen to measure strain. On loading, the changes in electrical resistance increased linearly with increasing strain, and the value reached 38% for the CFGFRP composites containing 0.36 vol% PAN-based high-strength carbon fibers. A tremendous change in electrical resistance was seen for the CFGFRP composites containing 0.38 vol% pitch-based high-property carbon fibers, and the composites could maintain their shape owing to a hybrid effect after the carbon fibers fractured. The change in electrical resistance can be controlled through suitable selection of the type of carbon fibers according to their values of ultimate elongation. Permanent, residual electrical resistance was found to remain, and the changes in resistance were dependent on the maximum previous strain.  相似文献   
245.
246.
The nucleation and growth of hydroxyapatite (HAp) crystals from solutions with and without Langmuir monolayers of stearic acid (SA) were investigated. The monolayers apparently enhanced the nucleation of HAp. Monolithic, filmlike polycrystalline HAp with preferred orientation of (00l) planes parallel to the monolayer interface was precipitated, while colloidal and powdery precipitation in the bulk solution was predominant in the absence of the monolayer. Geometrical similarity was found between the hexagonal packing conformation of the SA headgroups in the monolayers and the alignment of calcium ions in the (001) plane of HAp. It was suggested that HAp crystals nucleated and grew epitaxially on the monolayer interface.  相似文献   
247.
Recently, we found N1,N8-diacetylspermidine (Ac2Spd) and N1,N12-diacetylspermine (Ac2Spm) in human urine, and noted that their amount increased significantly in patients with urogenital malignancies. Previous findings that simultaneous reference to these diacetylpolyamines is useful in distinguishing cancer patients from healthy persons were confirmed by more recent analytical data on urine samples from several cancer patients. Further examination revealed that urinary Ac2Spm and Ac2Spd tended to decrease when cancer patients were treated and entered partial remission. In cases where the Ac2Spm and Ac2Spd levels were normal or near-normal after treatments, the prognosis of the patients was generally good. In contrast, when their level remained far above the normal limits after apparently effective treatment, the prognosis of the patients was poor. When a patient is in remission for more than 3 years, urinary levels of both Ac2Spm and Ac2Spd are stabilized and stay below the normal limits, with rare exceptions. The recurrence of a cancer as well as the complication of a second one during the period of follow-up examination was accompanied by elevation of urinary diacetylpolyamines. These observations indicate that urinary Ac2Spm and Ac2Spd are useful as prognostic indicators after treatment and during follow-up examination of cancer patients.  相似文献   
248.
The cerebral thrombus or blood clot might cause cerebral stroke and even decease if the clot could not be dissolved within several hours after it was formed. This paper presents the fundamental study on design of a micro stirrer for high effective dissolution. Based on the experimental results, the micro stirrer was analyzed by FEM with the fluid-structure interaction (FSI) analysis. The stirring effect was evaluated by the movement of the stirrer and the flow around the stirrer, and the performance index associated with the dissolution performance was presented. Using the performance index, several types of stirrers were evaluated. The obtained results demonstrated that the dissolution performance of the stirrer was influenced by the shape and the volume of the PZT actuator.  相似文献   
249.
The viscosity of some borosilicate glasses increases with heat-treatment time for phase separation. The viscosity increase in the initial stage of phase separation is attributed to the composition change of the separated phases. The origin of the viscosity increase in the later stage of phase separation is the subject of controversy. Namely, the viscosity increase has been attributed to two different mechanisms: (1) environmental relaxation and (2) the increase of silica content in the high-viscosity silica-rich continuous phase. Analyses are presented to show that the latter model is consistent with the experimental data.  相似文献   
250.
During a ten-year period, seven patients with traumatic rupture of the thoracic aorta were operated upon. Four patients of them were operated within one week. Chest X-rays and chest computed tomography could not always reveal the exact diagnosis of aortic rupture. Intravenous digital subtraction angiography was useful to confirm the diagnosis. The repair of the rupture was accomplished with the adjunct of left heart bypass using Bio-pump, which was useful to reduce the bloodloss with a limited systemic heparinization. Another three patients were diagnosed to have chronic post-traumatic aneurysm of the thoracic aorta and underwent aortic replacement with prosthetic graft. One of seven patients died at seventh postoperative day because of cerebral contusion, the associated lesion of an automobile accident. It is stated that the aortic rupture is immediately fatal in approximately 80% of individuals, and most of remaining 20% die within 2 weeks unless the lesion is repaired. Therefore immediate operative intervention is recommended when the aortic rupture is strongly suspected. Chronic post-traumatic aneurysms should be resected because it has become apparent that the majority of patients with this lesion will develop complication, such as sudden rupture.  相似文献   
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