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991.
This work reports the results obtained with the application of High Order Boltzmann Machines without hidden units to construct classifiers for some problems that represent different learning paradigms. The Boltzmann Machine weight updating algorithm remains the same even when some of the units can take values in a discrete set or in a continuous interval. The absence of hidden units and the restriction to classification problems allows for the estimation of the connection statistics, without the computational cost involved in the application of simulated annealing. In this setting, the learning process can be sped up several orders of magnitude with no appreciable loss of quality of the results obtained.  相似文献   
992.
INTRODUCTION: In a retrospective study a treatment concept for Perthes' disease dependent on the containment was applied. PATIENTS/METHODS: 49 hips of 41 children (9 female, 32 male) were treated between 01. 01. 1990 and 31. 12. 1995. In our concept of treatment a varus femoral osteotomy was performed in 28 cases with not contained hips or less than 4/5 coverage of the femoral head (X-ray/MRI). The other 21 well contained hips with 4/5 coverage or more were treated conservatively with physiotherapy and in case of joint effusion and pain additionally with the use of crutches (partial weight bearing) and anti-inflammatory medication. The average age in the non-operative group at the time of first investigation was 4 years and 9 months (3 y./1 m. to 7 y./1 m.) and 6 years and 3 months (4 y/2 m. to 10 y/0 m.) at our last examination (mean follow up 17.7 months, range of 6 to 72 months). At the time of indication for a varus femoral osteotomy the patients had an average age 6 years and 1 month (3 y./6 m. to 10 y./2 m.), the mean age at the last postoperative examination was 7 years and 11 months (4 y./8 m. to 12 y./5 m.) with an average follow up of 21.5 months (6 to 77 months). RESULTS: For the conservatively treated children we achieved good results (still well contained hips with 4/5 coverage, no decrease of function, no increase of pain) in 85.7% (18 of 21 cases). In 85.7% (24 of 28 cases) we found good results (well contained hips, increase of coverage, no decrease of function, no increase of pain) in the operation group. CONCLUSIONS: The presented concept of therapy in Perthes' disease was practicable for all patients and included the possibility of decision for operative or non-operative treatment. In both groups we achieved good results in 85.7% of the cases.  相似文献   
993.
994.
BACKGROUND: The transmission of hepatitis A virus (HAV) has been associated with the use of a number of solvent/detergent-treated factor VIII concentrates and possibly a factor IX concentrate. These reports have emphasized the necessity of using virus-inactivation methods for plasma products that are capable of inactivating nonenveloped viruses such as HAV. STUDY DESIGN AND METHODS: A simple, highly accurate titration procedure for HAV, which allows extensive kinetic investigations of virus-inactivation procedures, has been developed. This system has now been used to evaluate the efficacy of vapor heating in inactivating HAV after the addition of the virus to a range of human plasma products. RESULTS: It was demonstrated that HAV was significantly more thermostable than other picornaviruses, which reinforced the fact that such viruses cannot be used as model viruses for HAV-inactivation studies. A one-step vapor-heating procedure was demonstrated to inactivate between 5.9 and > 6.3 log10 of HAV in different products. A two-step vapor-heating procedure had the capacity to inactivate between > 8.7 and > 10.4 log10 of HAV. Both procedures were more effective in inactivating HAV than was the pasteurization procedure used for virus inactivation in human albumin solutions. CONCLUSION: These data demonstrate the efficacy of vapor heating in inactivating high-titer HAV after the spiking of plasma products with virus. This study confirms and explains the results of controlled clinical trials and long-term clinical usage with respect to the lack of HAV transmission by such vapor-heated products.  相似文献   
995.
BACKGROUND: Locally advanced thyroid cancer invading the tracheal cartilage represents a difficult treatment dilemma during thyroidectomy. METHODS: A retrospective chart review was performed to determine the results of laryngotracheal resection or tracheal cartilage shave with adjuvant radiotherapy in patients with locally advanced thyroid cancer invading the upper airway. RESULTS: Of 597 patients undergoing thyroidectomy for thyroid cancer, 40 were found to have laryngotracheal invasion. Thirty-five patients with superficial invasion underwent cartilage shave procedures with adjuvant radiotherapy; five with full-thickness invasion underwent radical resection, including tracheal sleeve resection (n = 3) or total laryngectomy (n = 2). Histologic subtypes included papillary (n = 32), follicular (n = 2), Hurthle cell (n = 1), medullary (n = 3), and anaplastic (n = 2). Of the cartilage shave group, 25 are currently alive with no evidence of disease at a mean follow-up of 81 months (range 1-290). Six developed isolated local/regional recurrence and were managed with total laryngectomy (n = 1), tracheal resection (n = 1), cervical lymphadenectomy (n = 1), or repeat radiotherapy (n = 3). All six patients remain free of disease at a mean follow-up of 5 years. Of those who underwent initial laryngotracheal resection, four remain free of disease at a mean follow-up of 5 years. The rates of 10-year disease-free survival and overall survival for all patients were 47.9% (95% confidence interval [CI] 24.8, 71.0) and 83.9% (95% CI 70.3, 97.5), respectively. CONCLUSIONS: These data suggest that adequate management of thyroid cancer with laryngotracheal invasion can be achieved with a more conservative surgical approach and adjuvant radiotherapy, reserving more radical resections for extensive primary lesions or locally recurrent disease.  相似文献   
996.
A CMOS log-polar image sensor has been designed and fabricated. As a result, a systematic approach has been proposed to design space-variant sensors and layouts. The pixels in this sensor are distributed in a polar fashion; the image plane consists of concentric rings containing the elementary sensing cells. Such a structure, where polygons use any space orientation, does not match very well with current design tools and CMOS fabrication processes. An approach to design nonorthogonal repetitive structures using standard fabrication processes and computer-aided design (CAD) tools is presented. The result of this work is an image sensor, with log-polar structure, suitable for image processing since the log-polar mapping has interesting mathematical and image data reduction properties  相似文献   
997.
Uterine angiomyolipomas are rare lesions composed of mature adipose tissue, smooth muscle, fibrous connective tissue, and blood vessels in varying proportions. We reported the first case of angiomyolipoma associated with a normal pregnancy. Initially, the tumor developed intramurally and could have been confused with a partial molar gestation. After delivery, tumor development was extensive and subserosal, making differential diagnosis from a sarcoma difficult. The question of histological diagnosis, as well as that of immunocytochemical analysis which seems to be helpful in such cases, is discussed here.  相似文献   
998.
It has recently been reported that there exists a new 'RING-finger' protein family among the zinc-finger (Zf) proteins. Previously, we had isolated the mouse Mel-18 cDNA (mMel-18) encoding the nuclear RING-finger protein that exhibits an ability to bind to a nonspecific DNA column. Here, we have isolated and characterized the human Mel-18 cDNA (hMel-18) using the mMel-18 cDNA as a probe. The deduced hMel-18 protein contains 344 amino acids (38 kDa) with a RING-finger motif, a helix-loop-helix (HLH)-like structure and a Pro/Ser-rich region. The hMel-18 gene is conserved among vertebrates. Its mRNA is highly expressed in placenta, lung and kidney, but the level is low in liver, pancreas and skeletal muscle. Using in situ hybridization, we mapped hMel-18 to band q22 of chromosome 12. It is possible that the Mel-18/bmi-1 gene family represents a mammalian homologue of the Drosophila polycomb gene group.  相似文献   
999.
An important aspect of blood-material interactions is the activation, adhesion, and subsequent aggregation of blood platelets on the artificial surface, all of which are directly affected by local fluid dynamics. The objective of this work was to directly correlate changing local fluid dynamic conditions produced by various vessel geometries, including stenosis, aneurysm, and separate contraction and expansion geometries, with quantitative in vitro measurements of regional platelet deposition. We directly measured platelet deposition as a function of axial position along four Lexan flow chambers with axisymmetric models of these geometries using 111In-labeled platelets. Platelet deposition was maximum in observed areas of flow recirculation and reattachment and minimum in locations of high shear and separation. For the stenosis geometry, two distinct regions of increased platelet deposition were apparent, one proximal to and one distal to the stenosis throat. An approximately linear increase in platelet densities was produced in the aneurysm region, increasing in the direction of flow. Through a comparison of platelet deposition with local fluid streamline orientation, we have shown that platelet deposition is increased in certain areas due to the enhanced convective transport of platelets and blood cells to the vessel wall along locally curved streamlines with velocity components perpendicular to the vessel wall.  相似文献   
1000.
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