Generative Design and Integrated 3D Printing Manufacture of Cross Joints

The integrated process of design and fabrication is invariably of particular interest and important to improve the quality and reduce the production cycle for structural joints, which are key components for connecting members and transferring loads in structural systems. In this work, using the generative design method, a pioneering idea was successfully realized to attain a reasonable configuration of the cross joints, which was then consecutively manufactured using 3D printing technology. Firstly, the initial model and generation conditions of a cross joint were constructed by the machine learning-based generative design algorithm, and hundreds of models were automatically generated. Then, based on the design objective and cost index of the cross joint, three representative joints were selected for further numerical analysis to verify the advantages of generative design. Finally, 3D printing was utilized to produce generative joints; the influences of printing parameters on the quality of 3D printing are further discussed in this paper. The results show that the cross joints from the generative design method have varied and innovative configurations and the best static behaviors. 3D printing technology can enhance the accuracy of cross joint fabrication. It is viable to utilize the integrated process of generative design and 3D printing to design and manufacture cross joints.     

Changes of TGF-β2, MMP-2, and TIMP-2 levels in the vitreous of patients with high myopia

Purpose

To investigate the concentrations of transforming growth factor (TGF)-β2, matrix metalloproteinase (MMP)-2, and tissue inhibitor of metalloproteinase (TIMP)-2 in the vitreous of patients with high myopia.

Methods

Twenty-six patients with high myopia (HM) who received vitrectomy for macular retinoschisis or macular hole were enrolled in this prospective study. Twenty-six patients with idiopathic macular hole or macular epiretinal membrane were chosen as a control group. Vitreous samples were obtained during the vitrectomy surgery. The levels of TGF-β2、MMP-2、TIMP-2 in the vitreous samples were measured by enzyme-linked immunosorbent assay. The MMP activity was determined by a fluorometric assay.

Results

There was no significant difference in the vitreous level of TGF-β2 between HM (1.64?±?0.38 ng/ml) and the control group (1.56?±?0.32 ng/ml, p?=?0.56). The vitreous levels of MMP-2 in HM (32.40?±?14.90 ng/ml) were significantly higher than in the control group (21.42?±?6.74 ng/ml, p?MMP-2/TIMP-2 was significantly elevated in the vitreous samples from HM (0.61?±?0.19), compared to the control group (0.48?±?0.11, p?p?Conclusions The elevated MMP/TIMP ratio and MMP activity may play a role in the pathogenesis of human high myopia. Large prospective studies are needed to further investigate the effect of MMPs in the pathogenesis of human high myopia.     

注射用奥沙利铂对比奥沙利铂脂质体Beagle犬的解剖病理学评价

目的:比较注射用奥沙利铂和奥沙利铂脂质体对Beagle犬毒性作用的解剖病理学改变,为抗癌药物脂质体制剂的临床前安全性评价提供重要的形态学参考数据。方法:Beagle犬分为阴性对照组、空载体脂质体组、注射用奥沙利铂组、奥沙利铂脂质体低、高剂量组。静脉滴注每2周给药1次,共4次,恢复期1个月。解剖动物进行组织病理学检查。结果:与脂质体、注射用奥沙利铂和奥沙利铂脂质体相关的组织病理学变化分别为多组织器官的泡沫细胞聚集;睾丸生精细胞数量减少,附睾精子减少症和胸腺、脾脏萎缩;肝脏小肉芽肿,胸腺、脾脏萎缩。结论:通过以上同一抗癌药物不同剂型对Beagle犬的解剖病理学评价比较,为抗癌药物脂质体剂型临床前安全性评价提供了重要的形态学参考数据。     

计算机辅助鼻额区域影像解剖学研究

OBJECTIVE: To evaluate the value of Advantage Windows 3.1 (AW 3.1) software for anatomical study of nasofrontal region, and to study the CT characteristics of nasofrontal region which related to the frontal sinus surgery. METHODS: Eighty patients underwent axial consecutive computed tomography scans and these data were studied with AW 3.1 software which provided reconstructional imaging of continuous coronal, sagittal, axial sections. Some related structures of nasofrontal region were studied and measured. RESULTS: AW 3.1 software could identify and measure the following structures accurately: The diameter of frontal sinus was (22.5 +/- 8.6) mm in height, (16.3 +/- 6.8) mm in depth, (23.8 +/- 9.8) mm in breadth. The diameter of frontal sinus ostium: the anterior-posterior diameter was (7.3 +/- 1.7) mm, the transverse diameter was (8.5 +/- 1.9) mm. The width of nasal beak of frontal bone(5.9 +/- 1.4 ) mm. The distance of frontal sinus ostium to the floor of columella nasi and the corresponding angle to the nasal floor were (60.8 +/- 4.2) mm and (70.1 +/- 4.7) degrees. The superior attachment sites of the uncinate process were as follows: lamina papyracea 41%, posteromedial wall of agger nasi cell 11%, middle turbinate 19%, anterior skull base 16%, superior bifurcation 13%. The cells could impinge on the frontal recess to cause obstruction (terminal recess 38.8%, anterior ethmoid cell 27.6%, agger nasi cells 24.5%). The accessory cells could impinge on the frontal sinus (perifrontal cells 32.7%, superaorbital cells 38.8%, intersinus septal cells 32.0%). There was significant difference between two groups of characteristics of nasofrontal region. CONCLUSIONS: AW 3.1 software is a helpful and powerful new tool for anatomical study of nasofrontal region and for preoperative evaluation. The structures of nasofrontal region are complex and various, frontal sinusitis almost always results from the obstruction of frontal sinus outflow tract. These results of anatomical study of nasofrontal region are helpful in directing the functional endoscopic surgery in frontal sinus.     

Treatment of 40 cases of infantile convulsion by Tuina

Infantile convulsion is a common disease in infants and babies and often caused by scare and improper nursing. Its main clinical manifestations are fright,crying and waking up with a start, etc. Since 1998, we have treated 40 cases by Tuina. It is summarized as follows.     

DCC基因转染对卵巢癌细胞HO-8910生长及化疗药物敏感性的影响

结直肠癌缺失(deleted in colorectal carcinoma, DCC)基因是于1990年确定并命名的重要的肿瘤抑癌基因,定位于人染色体18q21.3.DCC蛋白具有跨膜分子特征,其胞外部分氨基酸排序与神经细胞黏附分子相似.细胞黏附分子介导细胞间、细胞与基质间的相互作用,促进细胞与细胞间的黏附,是维持细胞生长的重要条件之一.有研究表明,良性卵巢肿瘤组织中DCC基因的表达缺失率为20%,恶性卵巢肿瘤组织中DCC基因的表达缺失率为56%,两者比较差异有显著意义.在临床分期晚、组织分化差、盆腹腔有转移的卵巢恶性肿瘤中DCC基因表达缺失率更高.     

人类体外受精与胚胎移植

收治不孕妇女34例,42个治疗周期,采用固定的Fertilin/Pergonal/Profasi超排方案,B超监测卵泡发育并指导经阴道取卵。每周期有6.97±4.1个卵泡发育。获得卵子4.7±4.6个,受精率为71％,卵裂率64％,移植率87.8％。每周期移植的胚胎总分与移植后妊娠率有显著相关性(r=0.8823,P=0.0086),移植胚胎评分高,数量多,妊娠率越高。本组5例妊娠中有3例移植6个胚胎以上。在未建立胚胎冻存技术之前,4个以上的胚胎移植是处理过剩胚胎的权衡方法。本组大部分病人在门诊接受治疗,减轻精神与经济负担。     

高同型半胱氨酸血症与2型糖尿病关系的研究进展

2型糖尿病及其并发症对人类健康的威胁已受到人们的广泛重视。近年来的研究发现,很多2型糖尿病患者合并高同型半胱氨酸(homocysteine,Hcy)血症的发生,且高Hcy血症与2型糖尿病并发症的发生、发展关系密切。本文对高Hcy血症的发生与2型糖尿病及其并发症的相互作用关系的研究进展进行综述。     

Measuring complexity using FuzzyEn, ApEn, and SampEn

This paper compares three related measures of complexity, ApEn, SampEn, and FuzzyEn. Since vectors' similarity is defined on the basis of the hard and sensitive boundary of Heaviside function in ApEn and SampEn, the two families of statistics show high sensitivity to the parameter selection and may be invalid in case of small parameter. Importing the concept of fuzzy sets, we developed a new measure FuzzyEn, where vectors' similarity is defined by fuzzy similarity degree based on fuzzy membership functions and vectors' shapes. The soft and continuous boundaries of fuzzy functions ensure the continuity as well as the validity of FuzzyEn at small parameters. The more details obtained by fuzzy functions also make FuzzyEn a more accurate entropy definition than ApEn and SampEn. In addition, similarity definition based on vectors' shapes, together with the exclusion of self-matches, earns FuzzyEn stronger relative consistency and less dependence on data length. Both theoretical analysis and experimental results show that FuzzyEn provides an improved evaluation of signal complexity and can be more conveniently and powerfully applied to short time series contaminated by noise.     

乙型肝炎病毒基因亚型研究进展

近年来,各国学者对乙型肝炎病毒（HBV）基因型及其亚型的研究十分关注。HBV基因型不仅能反映核酸变异程度和病毒种系发生关系,而且与感染者的临床表现、预后及疗效有关。目前,根据HBV全基因组序列差异≥8％,或S基因序列≥4％,将HBV分为A、B、C、D、E、F、G、H等8个基因型,但基因型H是否是独立于F的一个新基因型,还有待进一步证实。各基因型之间还存在混合感染,如B与C、C与D混合感染等∞。有人认为,混合感染可能与重叠感染或基因型之间的同源重组或部分转换有关。值得注意的是：近年来,除研究HBV基因型外,对HBV基因亚型也进行了深入研究,发现A基因型可进一步分为Aa和Ae亚型0;B型可分为B1（Bi）、B2（Ba）、B3和B4亚型N;C型可分为c1、c2、c3和c4亚型;D型可分为D1、D2、D3和D4亚型,F型可分为F1和F2亚型等（见表1）。