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排序方式: 共有230条查询结果,搜索用时 0 毫秒
21.
Anni Coden Guergana Savova Igor Sominsky Michael Tanenblatt James Masanz Karin Schuler James Cooper Wei Guan Piet C. de Groen 《Journal of biomedical informatics》2009,42(5):937-949
We introduce an extensible and modifiable knowledge representation model to represent cancer disease characteristics in a comparable and consistent fashion. We describe a system, MedTAS/P which automatically instantiates the knowledge representation model from free-text pathology reports. MedTAS/P is based on an open-source framework and its components use natural language processing principles, machine learning and rules to discover and populate elements of the model. To validate the model and measure the accuracy of MedTAS/P, we developed a gold-standard corpus of manually annotated colon cancer pathology reports. MedTAS/P achieves F1-scores of 0.97–1.0 for instantiating classes in the knowledge representation model such as histologies or anatomical sites, and F1-scores of 0.82–0.93 for primary tumors or lymph nodes, which require the extractions of relations. An F1-score of 0.65 is reported for metastatic tumors, a lower score predominantly due to a very small number of instances in the training and test sets. 相似文献
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BACKGROUND: Brainstem gliomas are highly heterogeneous tumors both in their clinical manifestation and in their pathology. Despite significant advances in the surgery for brainstem gliomas many aspects of this pathology are still unelear. OBJECTIVE: To evaluate the clinical, radiological and surgical outcome of 40 focal "intrinsic" brainstem gliomas and propose a surgical strategyoriented classification. MATERIALS AND METHODS: A total of 40 focal ‘intrinsie’ ("expanding variety") tumors have been operated over a period of 8.5-years (January 1998-June 2007). Our criteria included patients with (1) well-defined gadolinium enhancing tumor, (2) relatively long duration of symptoms (〉 six months) and (3) good neurological functional status and independent for all activities of davy living. The cutoff size of 2 cm was not rigidly adhered to. RESULTS: The "intrinsic" brainstem tumors were classified into three types: Expanding, diffuse infiltrative and pure ventral varieties. 相似文献
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Krutchen AE; Bjarnason H; Stackhouse DJ; Nazarian GK; Magney JE; Hunter DW 《Radiology》1996,200(1):159
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Alkaline phosphatase (AP) activities of sera from guinea fowl infected with osteopetrosis virus strain PTS-56 were investigated. Enzyme activities in birds of infected and control groups varied. AP activities in control guinea fowls, 10 to 15 weeks of age, were twice as high as those of 1-year-old birds whose growth was completed. A positive correlation was found between the intensity of virus-induced excessive bone growth and serum AP activity, which was 628 +/- 68.9 microM by the 17th week and reached 1283 + 76.8 microM by the 30th week post-infection (p.i.). Later AP activity decreased, but even at 52 weeks p.i. it was higher than that of untreated guinea fowl. The presumed high proportion of AP of bone origin of the total serum enzyme activities was supported by the low values of residual AP activity after heat inactivation at 58 degrees C (14.7 +/-3.7%) and after precipitation with wheat germ lectin (13 +/-1.2%) during the period of active bone tumour formation. 相似文献
27.
Cyclic neutropenia (CN): a clue to the control of granulopoiesis 总被引:2,自引:0,他引:2
A simple quantitative feedback model of granulopoiesis is presented and discussed within the framework of existing data on granulopoiesis in both normals and patients with cyclic neutropenia (CN). The model assumes that the controlled compartment is the bone marrow pool of mature neutrophils (PMNs), which sends a negative feedback signal to the mitotic pool of early granulocyte precursors (i.e., CFU-C, myeloblasts, etc.) thus controlling the granulocyte production rate. Three parameters are found to play important roles in determining the response of the system to perturbations. These are: TM, the granulocyte maturation time; a, a parameter reflecting the strength of the negative feedback exerted by mature PMNs on the granulocyte production rate; and b, a parameter describing the leakiness of the bone marrow for PMN egress. It is shown that depending on the relative magnitudes of a and b, the system will either respond to perturbations with a damped oscillation (a less than b: the normal state) or with a sustained oscillation (a greater than b: the CN state). In both cases, the oscillation period is found to approximately equal 2TM. Deductions of the values of a, b, and TM from experimental data are consistent with the predictions of the model and show an increased value of a in CN relative to the normal state. This suggests an overly active feedback mechanism as the pathophysiologic basis of CN. In addition, the model can explain how various therapeutic agent correct CN and also provides insight into why other hematologic cell lines and CSA oscillate in CN. 相似文献
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Weinberg JB; Misukonis MA; Shami PJ; Mason SN; Sauls DL; Dittman WA; Wood ER; Smith GK; McDonald B; Bachus KE 《Blood》1995,86(3):1184-1195
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