Comparison of four different orthokeratology lenses in controlling myopia progression

PurposeTo compare axial length (AL) elongation in myopic children with four Orthokeratology (OrthoK) lenses and spectacles.MethodsThe medical records of 266 patients (532 eyes) who were fitted with OrthoK lenses or spectacles (control group) were reviewed. Data collection included baseline age, gender, baseline objective sphere and cylinder, baseline flat and steep corneal meridian power, corneal asphericity coefficient (Q value), AL at baseline and after 1-year, and 2-years of OrthoK or spectacle wear analyzed using analysis of repeated measures data ANOVA. Stepwise linear regressions between the changes in AL after 2 years relative to baseline parameters were calculated for the OrthoK and control groups separately.ResultsThe baseline subject parameters for each of the four OrthoK lenses were not statistically different. Statistically significant differences between time points were found between 12- and 24- months (all P < 0.05). AL growth was slower in all OrthoK groups than in the control group (all P < 0.05). AL grew 0.081±0.034 mm per year slightly less than average with Essence compared to the Mouldway OrthoK group (P = 0.019). The coefficient of regression weakly expressed between the increases in AL over 2-years study period and baseline spherical equivalent refraction was 0.065 in Essence, 0.079 in Euclid and 0.087 in Mouldway. The coefficient of regression was also weakly between age and the increases AL over 2-years study period and baseline age in all groups.ConclusionDifferent OrthoK lenses differ minimally in slowing axial elongation effectively in myopic children during 2-years lens wear.     

丹東區域連續供熱分析

通過連續供熱與間歇供熱的分析比較,指出了間歇供熱的弊端,提倡連續供熱的采暖運行方式,希望通過解決一系列問題,實現連續供熱。     

我国合同法定解除权适用研究

无论是国外立法或是国内立法都明确限定,适用合同法定解除权不是绝对自由的,只有在一方当事人违约达到根本违约的程度时,另一方才有权适用合同法定解除权．合同法定解除权之正确、合理适用,关键在于准确把握根本违约的程度．在我国,如何认定根本违约,应严格以我国合同法中各种具体违约形态下根本违约的程度作为判定标准．     

基于突变级数法的地铁车站基坑施工风险研究

地铁车站基坑条件复杂,影响基坑施工因素多,导致地铁车站基坑施工中面临众多风险,针对地铁车站施工的风险问题,通过对地铁车站基坑施工风险分析,建立了地铁车站基坑工程施工风险评价指标体系(6个一级指标、17个二级指标)。然后将突变级数法应用到地铁车站基坑施工风险分析中,相对于其他风险评价方法,突变级数法不需要计算权重,且是基于状态变量的动态评价方法,弥补了静态评价方法的不足,减少了主观性。并以天津凌宾路地铁车站为例,分析了基坑事故原因相互作用对事故的影响,对车站基坑施工风险概率进行了计算,同时对结果进行了分析处理,采取了相应的防范措施,在基坑施工风险预防中得到了很好的应用。     

Activation of VCAM-1 and Its Associated Molecule CD44 Leads to Increased Malignant Potential of Breast Cancer Cells

VCAM-1 (CD106), a transmembrane glycoprotein, was first reported to play an important role in leukocyte adhesion, leukocyte transendothelial migration and cell activation by binding to integrin VLA-1 (α4β1). In the present study, we observed that VCAM-1 expression can be induced in many breast cancer epithelial cells by cytokine stimulation in vitro and its up-regulation directly correlated with advanced clinical breast cancer stage. We found that VCAM-1 over-expression in the NMuMG breast epithelial cells controls the epithelial and mesenchymal transition (EMT) program to increase cell motility rates and promote chemoresistance to doxorubicin and cisplatin in vitro. Conversely, in the established MDAMB231 metastatic breast cancer cell line, we confirmed that knockdown of endogenous VCAM-1 expression reduced cell proliferation and inhibited TGFβ1 or IL-6 mediated cell migration, and increased chemosensitivity. Furthermore, we demonstrated that knockdown of endogenous VCAM-1 expression in MDAMB231 cells reduced tumor formation in a SCID xenograft mouse model. Signaling studies showed that VCAM-1 physically associates with CD44 and enhances CD44 and ABCG2 expression. Our findings uncover the possible mechanism of VCAM-1 activation facilitating breast cancer progression, and suggest that targeting VCAM-1 is an attractive strategy for therapeutic intervention.     

堰塞坝稳定性快速评估模型--以小岗剑(上)堰塞坝为例

为了对堰塞坝的稳定性快速作出定量评价,通过分析历史案例并进行相关性分析,选取堰塞坝坝长、坝宽、坝高、回水长度、库容量作为堰塞坝稳定性评价因素,并进行主成分分析。将单一变量按照主成分大小及权重进行组合,得到坝高因子,高宽比,水流冲击系数,湖面形状系数,坝体形状系数五个复合因素,在此基础上提出一种定量分析堰塞坝稳定性的快速评估模型,同时引入稳定性系数来反映堰塞坝的稳定程度,进行等级划分,并对汶川大地震中形成的小岗剑(上)堰塞坝应用模型进行评估。结果表明所提出的模型判定准确率达89.9%,可以为堰塞坝应急处理提供参考。小岗剑(上)堰塞坝判定为不稳定,需及时采取泄流措施避免灾害损失。     

长江三峡工程实施计划与工程建设的最新进展

三峡工程是治理开发长江的关键工程，其效益主要表现在防洪、发电和航运等方面，该工程建成后，可得到巨大而持久的社会经济效益，其宏观效益将辐射到全中国。三峡工程宏伟而浩大，在80000m3／s流量和60m水深的长江上修建拦河大坝，无论从整体工程到每个单项工程都达到或超越当今世界最高等级。三峡工程总工期为17年，1997年大江截流，2003年第一批机组发电，2009年全部竣工。目前各项工程正按预定计划实施，施工进展顺利。     

浅谈合同违约中的效率违约

从经济学的效率观念出发,介绍了效率违约理论的内容,在分析效率违约理论成立条件的基础上,研究了效率违约制度的可行性,为更好的规制和发展效率违约提供了参考。     

"Interdomain transfer between isomorphic topics in algebra and physics": Correction to Bassok and Holyoak (1989).

Reports an error in "Interdomain transfer between isomorphic topics in algebra and physics" by Miriam Bassok and Keith J. Holyoak (Journal of Experimental Psychology: Learning, Memory, and Cognition, 1989[Jan], Vol 15[1], 153-166). On page 157, parts of two sentences in the Results and Discussion section were omitted. The corrected sentences are provided in the erratum. (The following abstract of the original article appeared in record 1989-17879-001.) Three experiments examined transfer between 2 isomorphic subdomains of algebra and physics. The two areas were arithmetic-progression problems in algebra and constant-acceleration problems in physics. High school and college students who had learned one of these subtopics were presented with word problems that used either content from the domain they had originally studied or content based on the unfamiliar but analogous domain. Ss who had learned arithmetic progressions were very likely to spontaneously recognize that physics problems involving velocity and distance can be addressed using the same equations. Analysis of problem-solving protocols revealed that the recognition was immediate and that the solutions were a straightforward application of the algebraic method. Such recognition occurred even when the algebraic procedures were taught using example word problems all of which were drawn from a single content area (e.g., "money" problems). In contrast, Ss who had learned the physics topic almost never exhibited any detectable transfer to the isomorphic algebra problems. The results were interpreted in terms of content-free vs content-specific applicability conditions for mathematical procedures. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

高应力下接触面抗剪特性影响因素分析

通过在DRS 1型微机高压直残剪试验系统上所进行的建筑砂、标准砂、粉土和粘土与砼、金属光滑、金属粗糙界面的正交直接剪切试验研究表明 :高应力作用下土体与刚度较大的界面的剪切应力 剪切位移曲线呈现出应变硬化的特征 ,与低应力作用下土与不同结构剪切特性存在明显的区别 .根据试验数据的方差分析和直观分析结果 :对于残余强度 ,法向应力的大小是第一影响因素 ,其次是土体的性质 ,第三是界面的基底性质 ,剪切速率的影响最小 ;对于剪切应力 -剪切位移曲线起始切线斜率 ,法向应力的大小、土体的性质是主要影响因素 ,第三是界面的基底性质 ,剪切速率的影响最小 .总的来看 ,影响高应力下接触面抗剪特性的主要影响因素是法向应力的大小 ,土体的性质是其次 ,剪切速率和基底性质的影响可以不予考虑 .