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1.
随着人们对影音设备视觉效果和互联网应用的不断提高,3D电视和智能电视得到了很快的发展,2010年中国平板电视市场被3D电视和智能电视所占据.  相似文献   

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Phospholipase D     
The performance of the Pathogen Modelling Program, the Food MicroModel, the Murphy-model and the Ross-model for growth of L. monocytogenes was evaluated by comparison with data from 100 seafood challenge tests and data from 13 storage trials with naturally contaminated sliced vacuum-packed cold-smoked salmon. Challenge tests with both cured and noncured products were studied, and graphs as well as the bias- and the accuracy factors were used for comparison of the observed and predicted growth. The Pathogen Modelling Program could not be successfully validated in seafood challenge tests. Growth rates were markedly overestimated and the mu(max)-bias factor was as high as 3.9 in challenge tests with cured products. On the basis of the effect of temperature, NaCl/a(w) and pH, the mu(max)-bias factor of the other three models studied, varied between 1.0 and 2.3 in the challenge tests with cured and noncured seafoods. None of the models accurately predicted the growth in both cured and noncured seafoods. However, the results indicated that a new expanded model, including the additional effect of lactate and phenol, may provide accurate predictions of the growth of L. monocytogenes in challenge tests with various types of seafoods. Storage trials clearly showed the growth of L. monocytogenes in naturally contaminated cold-smoked salmon to be markedly slower than growth in inoculated challenge tests. Consequently, all four models substantially overestimated growth in the naturally contaminated products. Temperature, pH, NaCl/a(w) and lactate were measured in the storage trials and on the basis of these parameters, the Food MicroModel mu(max)-bias factor was 5.2. Clearly, the model could not be successfully validated with naturally contaminated cold-smoked salmon. To improve the applicability of predictive models to fish products, it is suggested to include studies with naturally contaminated products in the development and validation of models with seafood pathogens.  相似文献   

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Disturbances in dopaminergic systems have been implicated in the etiology of mood disorders. Although genetic factors also play an important role, no major gene has been identified. We conducted an association study using the dopamine D2, D3 and D4 receptor, and transporter gene polymorphisms, comparing 101 mood-disorder patients (52 bipolar and 49 unipolar) and 100 controls. Our results suggest that there is a significant association between the dopamine D4 receptor gene and mood disorders, especially major depression, but no association between the other polymorphisms and mood disorders. Further investigations are needed to clarify the clinical significance of this association in the pathophysiology of mood disorders.  相似文献   

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李阳  穆志纯 《工程科学学报》2013,35(11):1527-1532
针对人耳识别中存在姿态、光照变化等问题,提出信息融合的方法,将二维人耳和三维人耳的信息进行融合,以克服姿态、光照对人耳识别的影响.对于二维人耳,由于姿态等的变化会导致人耳图像数据在高维空间中呈现出非线性流形结构,采用等距映射这种流形学习算法进行特征提取,对三维深度人耳则采用3D局部二值模式进行特征提取,然后分别进行二维和三维人耳识别,最后在决策层进行融合识别.在79人的人耳数据库上进行了实验,每人8幅带姿态的二维人耳图像和6幅带光照的三维人耳深度图像.实验结果表明,与单独的二维人耳和三维人耳识别相比,融合之后的识别效果和认证效果均有很大的改善.   相似文献   

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In human object recognition, converging evidence has shown that subjects' performance depends on their familiarity with an object's appearance. The extent of such dependence is a function of the inter-object similarity. The more similar the objects are, the stronger this dependence will be and the more dominant the two-dimensional (2D) image-based information will be. However, the degree to which three-dimensional (3D) model-based information is used remains an area of strong debate. Previously the authors showed that all models with independent 2D templates that allowed 2D rotations in the image plane cannot account for human performance in discriminating novel object views. Here the authors derive an analytic formulation of a Bayesian model that gives rise to the best possible performance under 2D affine transformations and demonstrate that this model cannot account for human performance in 3D object discrimination. Relative to this model, human statistical efficiency is higher for novel views than for learned views, suggesting that human observers have used some 3D structural information.  相似文献   

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Although human D1 and D5 dopamine receptors are encoded by distinct genes and share only 50% sequence homology at the amino acid level, their pharmacological properties are identical. Using a selective D1 receptor photoaffinity radioligand, (+/-)-7-[125I]iodo-8-hydroxy-3-methyl-1-(4-azidophenyl)-2,3,4,5-tetrahyd ro-1H-3-benzazepine ([125I]MAB), we have further probed the molecular properties of these receptors in transfected GH4C1 rat pituitary cells. Under reversible, non-covalent binding conditions, [125I]MAB bound to both the D1 and the D5 receptors with identical affinities, dopaminergic selectivity and stereospecificity. Upon photoactivation of the bound [125I]MAB, the label was incorporated into a approximately 64,000 mol. wt protein corresponding to the D1 dopamine receptor. However, there was no specific photoincorporation of the ligand observed in D5 receptors. The lack of [125I]MAB photolabeling of D5 receptors was independent of the cell line chosen, since similar results were obtained using other transfected cells. The data suggest that although both D1 and D5 receptors share structurally similar binding sites, the protein domains around the sites are different. Thus, although there are currently no specific compounds which bind preferentially to D1 or D5 receptors, these receptors can be distinguished from one another by the inability of [125I]MAB to photolabel D5, but not D1, receptors. Such selective targeting of a specific receptor may be useful in understanding the functional importance and/or interaction between closely related members of the same receptor family when co-expressed in the same cell.  相似文献   

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A range of studies have shown that three-dimensional (3D)/four-dimensional (4D) computer-aided design (CAD) has positively impacted the productivity and safety of construction processes. However, its potential impact on the entire life cycle of construction projects has not yet been fully investigated. The opinions of construction professionals have generally been reported on the basis of one-time interviews during several case studies. No statistical approach has yet been adopted to examine the whole spectrum of views about 3D/4D CAD use in construction projects. This study presents a comprehensive statistical analysis about how construction engineers perceive the effectiveness of 3D/4D CAD during various tasks of the construction project life cycle. A focus group interview and a review of the literature produced a total of 35?application areas in which 3D/4D CAD can possibly improve existing construction processes. We identified the areas in which 3D/4D CAD has a high potential to significantly enhance project results by using an importance-performance analysis (IPA) and a questionnaire-based survey involving 165?respondents. These study results are expected to provide new business strategies for 3D/4D CAD by broadening its traditional application realm.  相似文献   

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The dopamine D3 receptor is expressed primarily in regions of the brain that are thought to influence motivation and motor functions. To specify in vivo D3 receptor function, we generated mutant mice lacking this receptor. Our analysis indicates that in a novel environment, D3 mutant mice are transiently more active than wild-type mice, an effect not associated with anxiety state. Moreover, D3 mutant mice exhibit enhanced behavioral sensitivity to combined injections of D1 and D2 class receptor agonists, cocaine and amphetamine. However, the combined electrophysiological effects of the same D1 and D2 agonists on single neurons within the nucleus accumbens were not altered by the D3 receptor mutation. We conclude that one function of the D3 receptor is to modulate behaviors by inhibiting the cooperative effects of postsynaptic D1 and other D2 class receptors at systems level.  相似文献   

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A prospective study was performed in 24 women with breast masses on mammography going on to surgical biopsy. 2D and 3D power mode and frequency shift color flow Doppler scanning and display were compared. Vessels were displayed as rotatable color volumes in 3D, superimposed on gray-scale slices. The latter were stepped sequentially through the imaged volume. Radiologists rated the masses in each display (3D, 2D and videotapes) on a scale of 1 to 5 (5 = most suspicious) for each of six conventional gray-scale and six new vascular criteria. Thirteen masses proved to be benign and 11 were malignant. 3D provided a stronger subjective appreciation of vascular morphology and allowed somewhat better ultrasound discrimination of malignant masses than did the 2D images or videotapes (specificities of 85%, 79% and 71%, respectively, at a sensitivity of 90%). Only in 3D did the vascularity measures display a trend towards significance in this small study.  相似文献   

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Chimeric D1/D2 receptors were constructed to identify structural determinants of drug affinity and efficacy. We previously reported that chimeras that had D1 receptor transmembrane domain VII together with amino-terminal sequence from the D2 receptor were nonfunctional. D2/D1 chimeras were constructed that contained D2 receptor sequence at the amino- and carboxyl-terminal ends and D1 receptor sequence in the intervening region. Chimeric receptors with D2 sequence from transmembrane domain 7 to the carboxyl terminus together with D2 receptor sequence from the amino terminus through transmembrane helix 4 (D2[1-4,7]) and 5 (D2[1-5,7]) bound [3H]spiperone with high affinity, consistent with the hypothesis that D2 receptor transmembrane domain I or II is incompatible with D1 receptor transmembrane domain VII. D2[1-4,7] and D2[1-5,7] had affinities similar to D1 and D2 receptors for most nonselective dopamine antagonists and had affinities for most of the selective antagonists that were intermediate between those of the parent receptors. D2[1-4,7] and D2[1-5,7] mediated dopamine receptor agonist-induced stimulation and inhibition, respectively, of cAMP accumulation. The more efficient coupling of D2[1-5,7] to inhibition of cAMP accumulation, compared with the coupling of D2[5-7] and D2[3-7], supports the view that multiple D2 receptor cytoplasmic domains acting in concert are necessary for receptor activation of Gi. In contrast, D2[1-4,7], which contains only one cytoplasmic loop (the third) from the D1 receptor, is capable of activating Gs. D2[1-4,7] exhibited several characteristics of a constitutively active receptor, including enhanced basal (unliganded) stimulation of cAMP accumulation, high affinity for agonists even in the presence of GTP, and blunted agonist-stimulated cAMP accumulation. A number of dopamine receptor antagonists were inverse agonists at D2[1-4,7], inhibiting basal cAMP accumulation. Some of these drugs were also inverse agonists at the D1 receptor. Interestingly, several antagonists also potentiated forskolin-stimulated cAMP accumulation via D2[1-5,7] and via the D2 receptor, which could reflect inverse agonist inhibition of native constitutive activity of this receptor.  相似文献   

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3D Print Show     
《Metal Powder Report》2014,69(1):33-35
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STUDY DESIGN: This study involved weekly radiographic examination of pinealectomized rats, hamsters, and chickens to observe the development of scoliosis. OBJECTIVES: To determine whether pinealectomy produces scoliosis in animals more closely related phylogenetically to humans than to chickens, namely rats and hamsters, which are representative of mammals. SUMMARY OF BACKGROUND DATA: Pinealectomy in 3-day-old chickens has consistently resulted in the development of scoliosis with many characteristics similar to those seen in patients with adolescent idiopathic scoliosis. It has not been determined whether this phenomenon is restricted solely to chickens or is applicable to other animals, especially those more closely related to humans. METHODS: The pineal gland was removed from young rats, hamsters, and chickens. All animals underwent radiography weekly to detect the development of any scoliosis. Weight and length measurements were also taken weekly, and serum melatonin levels were determined at the time the animals were killed. RESULTS: Scoliosis was not observed in either the rats or the hamsters. In contrast, scoliosis developed in 10 of 21 chickens. Serum melatonin levels in all pinealectomized animals were zero. CONCLUSIONS: In contrast to the chickens, pinealectomy does not seem to cause scoliosis in either young rats or hamsters. The reasons for this discrepancy may include differences in the physiology and spinal morphology of the rat and hamster in comparison with the chicken. In the pinealectomized chickens, the results also suggest that future scoliosis development might be indicated by a significant increase in size when they are compared with pinealectomized chickens that do not develop scoliosis. Such differences in growth rates also distinguish patients with adolescent idiopathic scoliosis.  相似文献   

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