986 resultados para 136-843B


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为探讨HLA DQB1等位基因与胃腺癌临床特征及其幽门螺杆菌 (Hp)感染的关联性 ,运用序列特异性引物聚合酶链反应技术 ,检测无亲缘关系湖北汉族健康人 136例、胃癌组 6 3例患者的HLA DQB1基因。内镜活检、Giemsa染色和 (或 )外周血ELISA检查胃粘膜Hp感染情况。SAS软件统计处理。结果表明HLA DQB1 0 30 1与湖北汉族人胃腺癌呈正关联。携带与非携带该等位基因患者 ,其临床特征包括患者平均患病年龄、性别比、肿瘤原发部位、肿瘤TNM分期、肿瘤细胞分化程度 ,以及Hp感染率等情

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目的 探讨人类白细胞抗原 (HLA) DRB1等位基因与胃腺癌及其临床特征和幽门螺杆菌(Hp)感染的关联性。方法 运用序列特异性引物聚合酶链反应和等位基因序列分析技术 ,检测无亲缘关系湖北省汉族健康人 136例、胃癌组 6 3例的HLA DRB1基因。内镜活检、Giemsa染色和 (或 )外周血ELISA检查胃黏膜Hp感染情况。SAS软件数据处理。 结果 HLA DRB10 90 1、12等位基因均与湖北省汉族人胃腺癌呈正相关 ;HLA DRB115等位基因则呈负相关。携带及非携带上述各等位基因患者 ,分

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目的 探讨人类白细胞抗原HLA DRB1, DQB1等位基因与大肠癌遗传关联性。方法 运用序列特异性引物聚合酶链反应 ,结合等位基因序列分析 ,检测无亲缘关系的湖北籍汉族健康人136名、大肠癌组 5 4例患者的HLA DRB1、 DQB1基因。结果 大肠癌患者与正常人比较 ,HLA DRB1 0 90 1等位基因分布频率明显增高 (0 2 315、0 1397,P =0 0 33) ;而 DRB1 0 80X等位基因频率明显降低 (0 0 0 93、0 0 80 9,P =0 0 0 71)。两组间HLA

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目的从基因水平探讨湖北地区汉族人食管癌 HEN-DQB1等位基因的遗传易感性.方法运用序列特异性引物聚合酶链反应技术,检测无亲缘关系湖北汉族健康人136例、食管癌组42例患者的 HLA-DQB1等位基因.SAS system 统计软件数据处理.结果湖北汉族人食管癌患者与正常人比较,HEN-DQB1*0301基因频率显著增高(0.2976 vs 0.1875),P=0.046,OR=1.835,病因分数=0.1354);两组间 HLA-DQB1其余各等位基因分布频率的比较,HLA-DQB1*0201(0.0

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Film bulk acoustic resonators (FBARs) and solidly mounted resonators (SMRs) have the potential to significantly improve upon the sensitivity and minimum detection limit of traditional gravimetric sensors based on quartz crystal microbalances (QCMs) and surface acoustic wave resonators (SAWs). To date, neither FBAR nor SMR devices have been demonstrated to be superior to the other; hence the choice between them depends primarily on the users' ability to design/fabricate membranes and/or Bragg reflectors. In this work, it is shown that identically designed FBAR and SMR devices resonating at the same frequency exhibit different responsivities to mass loadings, Rm, and that the SMRs are less responsive than the FBARs. For the specific device design and resonant frequency (~2 GHz) of the resonators presented here, the FBARs' mass responsivity is ~20% greater than that of the SMRs', and although this value is not universal for all possible device designs, it clearly shows that FBAR devices should be favoured over SMRs in gravimetric sensing applications where the FBARs' fragility is not an issue. Numerical calculations based on Mason's model offer an insight into the physical mechanisms behind the greater FBARs responsivity, and it was shown that the Bragg reflector has an effect on the acoustic load at one of the facets of the piezoelectric films which is in turn responsible for the SMRs' lower responsivity to mass loadings. © 2013 Elsevier B.V.

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High conversion LWRs concepts typically rely on a heterogeneous core configuration, where fissile zones are interspersed with fertile blanket zones in order to achieve a high conversion ratio. Modeling such a heterogeneous structure of these cores represents a significant challenge to the conventional reactor analysis methods. It was recently suggested to overcome such difficulties, in particular, for the case of axially heterogeneous reduced moderation BWRs, by introducing an additional set of discontinuity factors in axial direction at the interfaces between fissile and fertile fuel assembly zones. However, none of the existing nodal diffusion core simulators have the capability of accounting for discontinuity of homogeneous nodal fluxes in axial direction since the fuel composition of conventional LWRs is much more axially uniform. In this work, we modified the nodal diffusion code DYN3D by introducing such a capability. The new version of the code was tested on a series of reduced moderation BWR cases with Th-U233 and U-Pu-MA fuel. The library of few-group homogenized cross sections and the data required for the calculation of discontinuity factors were generated using the Monte Carlo transport code Serpent. The results obtained with the modified version of DYN3D were compared with the reference Monte Carlo solutions and were found to be in good agreement. The current analysis demonstrates that high conversion LWRs can in principle be modeled using existing nodal diffusion core simulators. © 2013 Elsevier Ltd. All rights reserved.

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Touchscreen devices are often limited by the complexity of their user interface design. In the past, iterative design processes using representative user groups to test prototypes were the standard method for increasing the inclusivity of a given design, but cognitive modeling has potential to be an alternative to rigorous user testing. However, these modeling approaches currently have many limitations, some of which are based on the assumptions made in translating a User Interface (UI) into a definition file that cognitive modeling frameworks can process. This paper discusses these issues and postulates potential approaches to improvements to the translation procedure. © 2013 Springer-Verlag Berlin Heidelberg.

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根据野外调查与室内养殖的结果,稀有鮈鲫的繁殖季节为3—11月,在人工控制条件下可周年繁殖。在适宜的水温和充足的饵料条件下孵出后4个月左右即可达性成熟并产卵。对7对鱼共136批次产卵进行了观察统计,平均每尾雌鱼5.4d产卵一次,平均每次产卵300.3粒。根据卵母细胞发育进程、卵径分布、产卵频次以及年产卵量大于怀卵量、含卵量等特征,建议将稀有鮈鲫的特殊产卵类型命名为连续产卵类型,并与生态学上常用的“多次产卵”、“分批产卵”加以区别。最后就稀有鲍鲫作为一种新的实验鱼等应用前景作了展望。

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A design methodology is presented for turbines in an annulus with high end wall angles. Such stages occur where large radial offsets between the stage inlet and stage outlet are required, for example in the first stage of modern low pressure turbines, and are becoming more prevalent as bypass ratios increase. The turbine vanes operate within s-shaped ducts which result in meridional curvature being of a similar magnitude to the bladeto-blade curvature. Through a systematic series of idealized computational cases, the importance of two aspects of vane design are shown. First, the region of peak end wall meridional curvature is best located within the vane row. Second, the vane should be leant so as to minimize spanwise variations in surface pressure-this condition is termed "ideal lean." This design philosophy is applied to the first stage of a low pressure turbine with high end wall angles. © 2014 by ASME.

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Intermediate pressure (IP) turbines in high bypass ratio civil aeroengines are characterized by a significant increase in radius and a low aspect ratio stator. Conventional aerodynamic designs for the IP turbine stator have had leading and trailing edges orthogonal to the hub and casing end walls. The IP turbine rotor, however, is stacked radially due to stress limits. These choices inevitably lead to a substantial gap between the IP stator and rotor at the outer diameter in a duct that is generally diffusing the flow due to the increasing radius. In this low Mach number study, the IP stator is redesigned, incorporating compound sweep so that the leading and trailing edges are no longer orthogonal to the end walls. Computational investigations showed that the nonorthogonal stator reduces the flow diffusion between the stator and rotor, which yields two benefits: The stator trailing edge velocity was reduced, as was the boundary layer growth on the casing end wall within the gap. Experimental measurements confirm that the turbine with the nonorthogonal stator has an increased efficiency by 0.49%, while also increasing the work output by 4.6%, at the design point. © 2014 by ASME.

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An experimental investigation of a turbine stage featuring very high end wall angles is presented. The initial turbine design did not achieve a satisfactory performance and the difference between the design predictions and the test results was traced to a large separated region on the rear suction-surface. To improve the agreement between computational fluid dynamics (CFD) and experiment, it was found necessary to modify the turbulence modeling employed. The modified CFD code was then used to redesign the vane, and the changes made are described. When tested, the performance of the redesigned vane was found to have much closer agreement with the predictions than the initial vane. Finally, the flowfield and performance of the redesigned stage are compared to a similar turbine, designed to perform the same duty, which lies in an annulus of moderate end wall angles. A reduction in stage efficiency of at least 2.4% was estimated for the very high end wall angle design. © 2014 by ASME.

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A small strain two-dimensional discrete dislocation plasticity framework coupled to vacancy diffusion is developed wherein the motion of edge dislocations is by a combination of glide and climb. The dislocations are modelled as line defects in a linear elastic medium and the mechanical boundary value problem is solved by the superposition of the infinite medium elastic fields of the dislocations and a complimentary non-singular solution that enforces the boundary conditions. Similarly, the climbing dislocations are modelled as line sources/sinks of vacancies and the vacancy diffusion boundary value problem is also solved by a superposition of the fields of the line sources/sinks in an infinite medium and a complementary non-singular solution that enforces the boundary conditions. The vacancy concentration field along with the stress field provides the climb rate of the dislocations. Other short-range interactions of the dislocations are incorporated via a set of constitutive rules. We first employ this formulation to investigate the climb of a single edge dislocation in an infinite medium and illustrate the existence of diffusion-limited and sink-limited climb regimes. Next, results are presented for the pure bending and uniaxial tension of single crystals oriented for single slip. These calculations show that plasticity size effects are reduced when dislocation climb is permitted. Finally, we contrast predictions of this coupled framework with an ad hoc model in which dislocation climb is modelled by a drag-type relation based on a quasi steady-state solution. © 2013 Elsevier Ltd. All rights reserved.