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1.
The efficacy of an oxidized regenerated cellulose barrier (Interceed) in reducing postoperative adhesion formation and improving reproductive outcome after ovarian surgery was evaluated in a prospective randomized trial. Twenty-nine New Zealand White female rabbits were submitted to a mid-line laparotomy and a standardized surgical incision was made on both ovaries. At random, one ovary was entirely wrapped in a sheet of Interceed, whereas the contralateral ovary was left uncovered. Four weeks following surgery, the rabbits were mated with a male of proven fertility. Two weeks later, a second-look laparotomy was performed by a blinded observer who evaluated the incidence and score of adhesions, the number of corpora lutea in each ovary, the number of embryos in the ipsilateral uterine horn and also calculated the nidation index for each side. Adhesions were observed in 66% of Interceed-covered and in 97% of control ovaries (P < 0.0001). The adhesion score on the Interceed side was significantly lower than on the control side. The nidation index for the Interceed side was significantly higher than for the control side. The authors conclude that, in the rabbit model, Interceed significantly reduces the incidence and score of postoperative ovarian adhesions and significantly improves reproductive outcome.  相似文献   
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A number of HF signal injection techniques have been proposed for the sensorless zero-low-frequency control of induction machines (IMs). This paper reviews these methods and experimentally investigates their performance under true sensorless conditions for a standard cage IM with closed rotor slots. Implementation techniques covering hybrid methods, saliency decoupling, and saliency orientation are discussed. The paper concludes that, while HF techniques can outperform observer-based methods at low frequencies, the robust performance required for industrial application still presents a research challenge.  相似文献   
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Wine tourism is becoming an increasingly important tourism niche with various regions competing for tourism dollars. It is often assumed that differentiation in the sector is region based. This research investigates the positioning narratives from websites of a sample of top wine tour service firms across the US and Australia. Analysis is undertaken using an innovative methodology that combines computer-based lexical analysis followed by hierarchical clustering on principal components. The research seeks to determine the extent to which identified clusters are region based and whether the positioning narratives on websites can provides useful clusters across regions. Results are reported, implications are discussed, limitations are noted and possible areas for further research are indicated.  相似文献   
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Multitask Learning   总被引:10,自引:0,他引:10  
Caruana  Rich 《Machine Learning》1997,28(1):41-75
Multitask Learning is an approach to inductive transfer that improves generalization by using the domain information contained in the training signals of related tasks as an inductive bias. It does this by learning tasks in parallel while using a shared representation; what is learned for each task can help other tasks be learned better. This paper reviews prior work on MTL, presents new evidence that MTL in backprop nets discovers task relatedness without the need of supervisory signals, and presents new results for MTL with k-nearest neighbor and kernel regression. In this paper we demonstrate multitask learning in three domains. We explain how multitask learning works, and show that there are many opportunities for multitask learning in real domains. We present an algorithm and results for multitask learning with case-based methods like k-nearest neighbor and kernel regression, and sketch an algorithm for multitask learning in decision trees. Because multitask learning works, can be applied to many different kinds of domains, and can be used with different learning algorithms, we conjecture there will be many opportunities for its use on real-world problems.  相似文献   
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Small cell neuroendocrine carcinomas (SNECs) of the sinonasal tract are extremely uncommon tumors. We reviewed the clinicopathologic features of six cases of this neoplasm. There was no sex preponderance with three females and three males and a mean age at presentation of 51 years (range, 38 to 68). Two patients had disease limited to the nasal cavity, and in four the tumor involved the nasal cavity and maxillary or ethmoid sinuses. Involvement of the orbit was present in two patients. Surgery was the primary treatment. After a mean follow-up of 37 months, one patient died of local disease and liver metastases, four were alive with recurrent or metastatic disease, and one died of unrelated causes. The tumors were composed of sheets, nests, and trabeculae with extensive areas of necrosis and hemorrhage. The individual cells were small to intermediate in size and had scanty cytoplasm. The nuclei were oval or round and hyperchromatic with absent or inconspicuous nucleoli. Nuclear molding and crush artefact were present in five cases. All tumors had a high mitotic rate with frequent abnormal mitotic figures. All cases stained for Cam 5.2, neuron-specific enolase, and chromogranin. Five cases were positive for AE1:AE3, and four for synaptophysin. No case stained for S-100 protein, or neurofilaments. O-13 stained one case. No case contained EBV-RNA. SNECs of the nasal cavity and paranasal sinuses are aggressive tumors with pathological features similar to those of anaplastic small cell carcinomas of the lung. They exhibit morphological and immunophenotypic features different from olfactory neuroblastoma and should be distinguished from this tumor.  相似文献   
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The suitability of Ni3Al intermetallics as reinforcement for Al-base materials for tribological applications has been investigated. For this purpose, an Al/Ni3Al (5 vol pct) composite was prepared by powder metallurgy and tested in air against steel counterfaces at the load range of 45 to 178 N. For comparison, unreinforced Al specimens were processed and tested under the same conditions. Tribological behavior was evaluated by microstructural examination of wear-affected zones and weightloss measurements of specimens and counterfaces. It was found that a significant amount of Fe-rich oxide particles become incorporated into the Al matrix during wear, forming a cracked tribolayer. The wear behavior of Al/Ni3l composite as a function of the applied load was not accurately reflected by the weight loss of worn specimens. Results highlight the role of Ni3Al particles as loadbearing elements due to their excellent bonding to the Al matrix, their interfaces withstanding the wear stresses even at the highest applied load. Moreover, Ni3Al particles limited the incorporation of wear debris to the Al matrix and reduced wear damage occasioned to the steel counterfaces compared to that of pure aluminum specimens. Formerly with the Physical Metallurgy Department (CENIM-CSIC)  相似文献   
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