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111.
Due to their complex microstructures, the research on the static and dynamic behaviors of triangular honeycomb sandwich panels (triangular HSPs) is limited. In this study, the effective plate properties of triangular HSP was obtained by the homogenizing of the unit cell, and then the input to a VAM-based two-dimensional equivalent plate model (2D-EPM) to perform static and dynamic analyses. The accuracy of the proposed model for predicting the equivalent stiffness of the triangular HSP was verified by three-point bending experiments of 3D-printed specimens. Then, the static displacement, global buckling, and free vibrations predicted by 2D-EPM were verified with the results from three-dimensional finite element model simulations under various boundary conditions. The influences of structural parameters (including angle, core wall thickness, and cell side length of the unit cell) on the static and dynamic characteristics of triangular HSPs were also investigated, which can provide a useful tool for the modeling and evaluation of triangular HSPs under different conditions.  相似文献   
112.
The spike protein (S) plays a crucial role in porcine epidemic diarrhea virus (PEDV) infection and induces neutralizing antibodies. Mutations of the S protein are supposed to provide the main antigenic shift leading to the antigenic escape of PEDVs. It is therefore a significant question how much accumulation of antigenic shift could lead to the antigenic escape of the variant PEDV. To provide an answer in the study, B cell epitopes (BCEs) on the S protein of the PEDV vaccine strain CV777 (SCV777) and variant strain SD2014 (SSD2014) were mapped using biosynthetic peptides and rabbit anti-PEDV S serum. Seventy-nine and 68 linear BCEs were identified from SCV777 and SSD2014, respectively. While 66.2% of the BCEs of SSD2014 could be recognized by anti-SCV777 serum and 67.1% of SCV777 BCEs could be recognized by anti-SSD2014 serum, more than 40% of the BCEs identified using anti-SCV777 serum on SCV777 could not be recognized by anti-SSD2014 serum and vice versa. The completely shared BCEs took low percentages of 29.4% and 25.3% for SSD2014 and SCV777, respectively. These results indicate a low conservation of antigenicity of the S protein compared to a relatively high amino acid sequence similarity of 92.2% between the two strains. The study provided a BCE shift reference of PEDV antigenic escape and surveillance control.  相似文献   
113.
为探索类胰岛素生长因子Ⅰ(IGFⅠ)基因转染许旺细胞的可能性,采用体外培养许旺细胞(SCs),构建IGFⅠ逆转录病毒载体,利用基因转染技术将IGFⅠ基因转入SCs,核酸分子杂交及细胞免疫组化检测SCs 表达IGFⅠm RNA及其蛋白水平,辅以正常SCs作对照。结果:pLXSNIGFⅠ转染的SCs在体外相同培养条件下较正常SCs 表达IGFⅠm RNA 及其蛋白水平能力分别增强48 和32 倍,均有显著意义。研究表明,利用基因转染技术可将外源性IGFⅠ基因转入SCs,提高SCs中的IGFⅠ的含量和活性  相似文献   
114.
目的:为人颅底的生长发育研究提供正常的颅底结构测量数据和参照标准;初步分析颅底生长发育趋势和特点。方法:对人不同生长发育阶段颅底标本诸结构进行观察和测量,并对其进行相互比较和纵向分析。结果:颅底在不同发育阶段各有其趋势和特点,蝶枕角随着年龄的增长逐渐变小,但性别之间无差异,颅前窝诸结构变化幅度最大,颅中窝的变化相对最小,11项测量指标在不同生长发育阶段的变化各异。结论:观察测量数据可为人颅底生长发育进一步研究提供依据,蝶枕角、耳眼(FH)平面可作为颅底生长发育的观察测量指标和参照平面。  相似文献   
115.
Gross chromatin imbalance and high DNA content are distinct features of various types of cancer cells. However, severe inflammation can also produce similar symptoms in cells. In this study, normal, inflammatory, and carcinoma hepatic cells were stained with 4’,6-diamidino-2-phenylindole (DAPI) and investigated by hyperspectral microscopy. DAPI is a DNA-sensitive fluorochrome. Therefore, the differences in the cellular DNA of the samples can be revealed by the corresponding fluorescence. Our experimental results demonstrate that although chromosomal disorder and high DNA content both occur in severely inflammatory and carcinoma hepatic cells, there is still a slight difference in their DNA, making their fluorescent intensity and even their spectral shapes distinguishable. Based on these spectral features, we developed a method for the precise identification of normal, inflammatory, and carcinoma hepatic cells in the field of view. The identification accuracy for these three types of cells was 99.8%. We believe that examination that combines DAPI staining with hyperspectral microscopy is a potential method for the identification and investigation of various types of cancer tissues.  相似文献   
116.
目的 观察模拟失重对人下肢脂肪体积的影响,验证磁共振水脂分离成像技术在测量人下肢脂肪容积中的可行性.方法 14名男性健康志愿者,-6°头低位卧床30 d,使用磁共振水脂分离成像(Dixon)技术采集卧床前后的下肢横断面解剖图像,测量卧床前后下肢脂肪体积.结果 与卧床前相比,卧床后所有志愿者下肢总脂肪体积及大腿段脂肪体积显著增加(P<0.001);小腿段脂肪体积呈增加趋势,但无统计学差异(P>0.05).结论 使用MRI水脂分离成像可以清晰地显示卧床前后下肢脂肪体积的变化;-6°头低位卧床30 d后下肢脂肪体积明显增加.  相似文献   
117.
小儿乙状结肠冗长症21例诊治分析   总被引:4,自引:1,他引:3  
目的总结小儿乙状结肠冗长症的临床特点、诊断及治疗方法。方法回顾性分析我院近7年来收治的21例乙状结肠冗长症患儿的病例资料,并结合文献讨论临床表现及诊疗方法。结果21例均获痊愈,经3个月~6年随访,患儿排便功能恢复,发育状况良好。结论小儿乙状结肠冗长症以慢性便秘和间歇性腹痛为主要症状;诊断主要根据钡剂灌肠检查,部分病例应与先天性巨结肠、特发性巨结肠鉴别;治疗方法首选非手术疗法,无效时行手术治疗。  相似文献   
118.
Objective: Recent studies have shown that the local expression of soluble interleukin (IL) -1 receptor type Ⅱ (slL-1 R Ⅱ ) in endometrial tissue of women with endometriosis is decreased, and the depression of IL-1 R Ⅱ was more significant in infertile women than that in fertile women with endometriosis. In this research, we investigated the remedial effect of slL-1-R Ⅱ administration on endometriosis in the nude mouse model. Methods: Nineteen nude model mice with endometriosis were randomly divided into three groups: group A was treated by intraperitoneal administration with only slL-1 R Ⅱ for two weeks, group B was similarly treated with only IL- 1, and group C (control) was administered saline. After 2 weeks, the size of the ectopic endometrial lesions was calculated, and the expression of vascular endothelial growth factor (VEGF) and B-cell lymphoma leukemia-2 (Bcl- 2) were detected by immunohistochemistry. The IL-8 and VEGF levels in the peritoneal fluid (PF) and serum were also measured by enzyme-linked immunosorbent assay (ELISA). Results: The mean size of ectopic endometrial lesion did not differ between the three groups (P 〉 0.05). Compared with the control, the expression of VEGF and Bcl-2 was significantly lower in group A, and higher in group B. In the three groups, the levels of IL-8 in the PF and serum were highest in group A, and lowest in group B. Conclusion: slL-1 R Ⅱ may suppresse hyperplasia of ectopic endometriosis, perhaps by reducing the expression of certain cytokines, such as VEGF, IL-8, and Bcl-2, which could provide a new clinical strategy for the treatment of endometriosis.  相似文献   
119.
踝关节骨折治疗体会   总被引:1,自引:0,他引:1  
目的:通过分析骨折受伤机制,探讨骨折治疗方法。方法:采取保守、手术及中药辨证施治。结果:平均随访时间8个月,优良率达95%。结论:明确受伤机制,准确的诊断分型及辨证施治可以取得良好的疗效。  相似文献   
120.
INTRODUCTION Siglec-15 is a member of the sialic acid-binding immunoglobulintype lectin (Siglecs) family, a group of cell-surface receptors that potentially reg...  相似文献   
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