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151.
The mean radiant temperature, Tmrt, which sums up all shortwave and longwave radiation fluxes (both direct and reflected) to which the human body is exposed is one of the key meteorological parameters governing human energy balance and the thermal comfort of man. In this paper, a new radiation model (SOLWEIG 1.0), which simulates spatial variations of 3D radiation fluxes and Tmrt in complex urban settings, is presented. The Tmrt is derived by modelling shortwave and longwave radiation fluxes in six directions (upward, downward and from the four cardinal points) and angular factors. The model requires a limited number of inputs, such as direct, diffuse and global shortwave radiation, air temperature, relative humidity, urban geometry and geographical information (latitude, longitude and elevation). The model was evaluated using 7 days of integral radiation measurements at two sites with different building geometries – a large square and a small courtyard in Göteborg, Sweden (57°N) – across different seasons and in various weather conditions. The evaluation reveals good agreement between modelled and measured values of Tmrt, with an overall good correspondence of R 2?=?0.94, (p?相似文献   
152.
DNA序列高维空间数字编码的运算法则   总被引:1,自引:0,他引:1  
DNA序列的高维空间二进制数字编码,除可以对DNA序列的碱基结构、功能基团、碱基互补、氢键强弱等性质进行编码之外,还可以方便地进行 数学运算和逻辑运算。DNA序列高维空间数字编码的运算法则是:(1)根据DNA序列数码的奇偶性质,可以推导出其与末位碱基的对应关系。当DNA序列S的数值X(S)=4n,4n 1,4n 2,4n 3时,其末位碱基依次为C,T,A,G(n=0,1,2,…)。(2)提出DNA序列高维空间的表观维数Nv,数值维数Nx及差异维数Nd的概念。当Nd=0时,首位碱基为A或G,当Nd=2n或2n 1(n=1,2,…)时,首痊碱基为(C)^n或(C)^nT。(3)推导出DNA序列点突变(单核苷酸多态性SNP)的运算法则。(4)推导出DNA重复序列(Tandem repeat)的运算法则。(5)提出DNA子序列(subsequence)的概念并定义DNA子序列的定值部Xi(digital value)和定位部Qi(location value)及其计算公式。(6)推导出DNA序列的延长运算、删除运算、缺失运算、插入运算、转位运算、换位运算和置换运算等的运算法则。(7)通过按位加运算求得DNA序列的汉明距离dh,碱基距离dh‘,基团距离dh″和共轭距离dG以及这些距离的意义与联系。(8)分析结果表明DNA序列的数字编码比常规的字符编码在数学运算上具有明显的优越性。  相似文献   
153.
将最新的科技成果、方法、手段,迅速、准确而有效地运用于知识和技能的传授是现代高等教育发展的必然趋势。组织学与胚胎学属基础医学形态学范畴,是一门以研究正常人体显微结构与功能关系的学科,也是医学生动手实践最早的学科之一。该学科的传统授课方式理论课为课堂讲授,实验课为实验室显微镜观察切片标本。从2007年开始,我们采用了显微数字化互动教学方式进行组织学与胚胎学实验教学。通过几年的实践探索感受颇深。  相似文献   
154.
目的:探讨超声造影评估原发性肝癌(HCC)数字减影血管造影(DSA)引导下肝动脉化疗栓塞(TACE)治疗疗效的价值。方法:选择2016年10月至2018年10月我院收治的77例HCC患者,均在DSA引导下行TACE治疗,治疗前后采用超声造影评价疗效。结果:77例HCC患者均顺利完成TACE治疗,治疗后始增强度、增强速率降低(P0.05),始增时间、达峰时间、峰值加速时间增加(P0.05)。治疗后完全缓解(CR)+部分缓解(PR)为有效共46例(有效组),稳定(SD)+进展(PD)为无效共31例(无效组),有效组治疗后始增强度、增强速率低于无效组(P0.05),始增时间、达峰时间、峰值加速时间多于无效组(P0.05)。受试者工作特征曲线(ROC)分析结果显示,始增时间、达峰时间、峰值加速时间、始增强度、增强速率预测HCC患者DSA引导下TACE治疗疗效的曲线下面积(AUC)分别为0.658、0.717、0.64、0.668、0.713。结论:超声造影定量参数在HCC患者DSA引导下TACE治疗前后有着较为明显的变化,其超声参数达峰时间、增强速率对DSA引导下TACE治疗疗效的预测效能较好。  相似文献   
155.
The “Ming” lethal egg mutant (l-em) is a vitelline membrane mutant in silkworm, Bombyx mori. The eggs laid by the l-em mutant lose water, ultimately causing death within an hour. Previous studies have shown that the deletion of BmEP80 is responsible for the l-em mutation in silkworm, B. mori. In the current study, digital gene expression (DGE) was performed to investigate the difference of gene expression in ovaries between wild type and l-em mutant on the sixth day of the pupal stage to obtain a global view of gene expression profiles using the ovaries of three l-em mutants and three wild types. The results showed a total of 3,463,495 and 3,607,936 clean tags in the wild type and the l-em mutant libraries, respectively. Compared with those of wild type, 239 differentially expressed genes were detected in the l-em mutant, wherein 181 genes are up-regulated and 58 genes are down-regulated in the mutant strain. The Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis results showed that no pathway was significantly enriched and three pathways are tightly related to protein synthesis among the five leading pathways. Moreover, the expression profiles of eight important differentially expressed genes related to oogenesis changed. These results provide a comprehensive gene expression analysis of oogenesis and vitellogenesis in B. mori which facilitates understanding of both the specific molecular mechanism of the 1-em mutant and Lepidopteran oogenesis in general.  相似文献   
156.

Purpose

Matrix metalloproteinases (MMPs) have been implicated in progression and metastases of different tumors. The balance between the MMPs and their natural inhibitors (tissue inhibitors of matrix metalloproteinases; TIMP) seem to be an important factor related to its role. The purpose of this study was to evaluate polymorphisms in the MMP-3 and TIMP-3 genes for their associations with prostate cancer (PCa) risk in North Indians.

Materials and methods

Genotypes were determined by PCR-RFLP (Polymerase Chain Reaction Restriction Fragment Length Polymorphism) method in 150 PCa patients and 200 age matched controls of similar ethnicity.

Results

We found significant association in the MMP-3(1171)5A/6A and TIMP-3 (1298) C/T polymorphism with PCa risk. Variant genotype (5A/5A) of MMP-3(1171)5A/6A polymorphism had a high PCa risk (p = 0.037, OR = 3.52, 95%CI = 1.08–11.5). Individuals with TIMP-3 (1298) CT genotype as well as T allele showed reduced risk of PCa (p < 0.001; OR = 0.31; 95%CI = 0.18–0.52, and p = 0.001; OR = 0.49; 95%CI = 0.32–0.75). This effect was even more evident in case of T allele carrier (CT + TT) (p < 0.001; OR = 0.36; 95%CI = 0.22–0.59). Overall no significant association was observed statistically in MMP-3 and TIMP-3 with any of the grading stages and smoking habits in PCa. Haplotype analysis of MMP-3 showed that A-5A-A was associated with three folds (OR = 3.06; 95%CI = 1.71–5.47; p < 0.001) increased risk in PCa patients.

Conclusion

This is the first reported association between polymorphisms in the MMP-3 and TIMP-3 gene and PCa risk and supports the hypothesis that the protease/antiprotease balance has an important role. Due to the small sample size further investigations need to be done to prove a statistical significant correlation between the MMP/TIMP expression and clinicopathological parameters.  相似文献   
157.
Failing to open computer files that describe image data is not the most frustrating experience that the user of a computer can suffer, but it is high on list of possible aggravations. To ameliorate this, the structure of uncompressed image data files is described here. The various ways in which information that describes a picture can be recorded are related, and a primary distinction between raster or bitmap based and vector or object based image data files is drawn. Bitmap based image data files are the more useful of the two formats for recording complicated images such as digital light micrographs, whereas object based files are better for recording illustrations and cartoons. Computer software for opening a very large variety of different formats of digital image data is recommended, and if these fail, ways are described for opening bitmap based digital image data files whose format is unknown.  相似文献   
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160.
Digital volume correlation (DVC) provides experimental measurements of displacements and strains throughout the interior of porous materials such as trabecular bone. It can provide full-field continuum- and tissue-level measurements, desirable for validation of finite element models, by comparing image volumes from subsequent µCT scans of a sample in unloaded and loaded states.  相似文献   
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