悬索桥上、下对合型索夹结构分析研究

为研究悬索桥上、下对合型索夹结构的受力特性,以柳州双拥大桥为背景,推导了理想排列的主缆在宏观受力意义下的横向弹性模量的上限值,并结合经验公式确定主缆横向弹性模量的取值范围。建立该桥主缆和索夹有限元模型,分析主缆横向弹性模量在一定范围内变化时的螺杆附加力系数、索夹内压系数和脱空角。结果表明,吊索力是造成上、下索夹内压应力分布明显不均匀的直接原因,增大螺杆夹紧力能增大索夹内压应力;吊索产生的螺杆附加力对主缆横向弹性模量变化不敏感;索夹内压系数在吊索力和主缆力作用下会相应变小;螺杆附加力应该考虑螺栓和被连接件的相对刚度影响;跨中索夹应从控制脱空角入手适时调整螺杆夹紧力。

基于改进密封性能的悬索桥索夹分析与优化设计

为改进悬索桥主缆索夹密封性能,以江苏省龙潭长江公路大桥为背景进行研究。采用ANSYS软件建立考虑主缆非线性横截面力学特性的索夹与主缆紧固作用分析有限元模型,研究索夹螺杆偏心距、索夹横截面尺寸对索夹体应力和主缆压缩变形的影响规律;并对索夹螺杆偏心距、嵌合构造及端口密封进行优化设计。结果表明:索夹体以承受面内弯拉应力为主,最大应力在圆弧段与连接耳过渡的变截面处,螺杆偏心距增加会导致索夹变截面处应力增大,增大索夹变截面处倒圆角半径使该处截面增厚,会降低索夹应力;索夹螺杆偏心距和截面尺寸对主缆横截面压缩变形影响很小。根据研究成果,将索夹螺杆孔壁到内壁间厚度由2.5 mm调整到10 mm,避免了内壁开槽孔对索夹密封性的不利影响;采用双层嵌合构造及端口搭接式环缝密闭措施,均有助于提高索夹对主缆的密封效果,有利于主缆防腐。

空心管件折弯加工时的质量问题及解决措施

主要介绍了空心管件在折弯加工中容易出现的质量问题，如：产品表面的划伤、夹伤、印痕等。并对问题的产生原因进行了深入的分析，并提出了具体的改进措施。通过批量生产验证，有效地解决了上述加工中出现的质量问题，提高了产品的良品率，降低生产成本，具有较高的实用推广价值。

An extensive DeBakey type IIIb aortic dissection with massive right pleural effusion presenting as abdominal pain and acute anemia： particular case report

We describe the case of a 79-year-old male presented with sudden onset of abdominal pain and mild breathlessness, and complicated acute progressive anemia with haemoglobin which declined from 120 g/L to 70 g/L within five days. An urgent computed tomography an- giography showed acute thoracic aortic dissection, DeBakey type IIIb, a dissecting aneurysm in the proximal descending thoracic aorta start- ing immediately after the origin of the left subclavian artery and extending distally below the renal arteries with evidence of rupture into the right pleural cavity for massive pleural effusion. Plasma D-dimer, brain natriuretic peptide and C reactive protein level were elevated. Our case showed that D-dimer can be used as a ＇rule-out＇ test in patients with suspected aortic dissection. A raised BNP may exert a protective role through anti-inflammatory endothelial actions in the systemic circulation.

Incidence and in-hospital mortality of acute aortic dissection in China： analysis of China Health Insurance Research （CHIRA） Data 2011

Objective Acute aortic dissection （AAD） is a catastrophic event with high early mortality rate, but to date, no data on the incidence of AAD in China's Mainland is available. This study aimed to estimate the incidence of AAD in China and characterize the clinical profile, management and in-hospital outcomes of this vascular event. Methods We used the China Health Insurance Research Data （the CHIRA Data） 2011 which comprises all inpatient hospital records （300,886） during the period of Jan. 1st 2011 to Dec. 31 2011 of 3,335,000 randomly sampled beneficiaries （1,718,500 men and 1,616,500 women） from 25 cities and counties in different economic-geographic regions of China's Mainland. Patients with acute aortic dissection were identified according to International Classification of Disease 10m Revision （ICD-10） of I71.0, The estimated incidence of AAD was calculated using the equation： estimated incidence = 2.0 × （40% × hospital admission rate） ＋ 60% × hospital admission rate. Results The hospital admission rate was 2.0/100,000 （65/3,325,000, 95% CI： 1.2-2.8）. The estimated annual incidence of AAD was 2.8/100,000 （95% CI： 1.9-3.6） and was higher in male than in female （3.7 vs. 1.5, P 〈 0.001）. The mean age was 58.9 ± 13.4 years. During the mean hospital stay of 23 ±6 days, the overall in-hospital mortality was 13.9% （9/65）. Conclusions Our study showed relatively lower but not negligible incidence and in-hospital mortality of AAD in the mainland of China. The mean age of patients with AAD in Chinese was younger than that reported by researches from west countries, while the male to female incidence ratio is similar to those reported by other studies.

《送李愿归盘谷序》的“两宾夹一主”

韩愈在《送李愿归盘谷序》一文中把闲居人放在得意人与奔走伺候人两类人之间,正是表明他的独具匠心:对'大丈夫'和'奔走形势之途之人'的态度是嘲讽,对李愿有友人的赞赏,同时也委婉道出自己对隐士生活的向往,暗含自己不得志之意。

Endovascular stent-graft for type B aortic dissection in elderly patients

Objective To report the clinical outcome and complications ofendovascular stent-graft treatment for type B aortic dissection in elderly patients, as compared with younger patients in a single medical center. Methods From May 2002 to July 2008, endovascular stent-graft implantation was performed in 124 patients with type B aortic dissection at the Department of Cardiology, Shenyang Northern Hospital. Among them, 39 patients were 60 yrs or older （ranging ~om 68 to 81 years） while 85 patients were younger than 60 years old （ranging from 31 to 58 years）. Patients were followed up for a mean period of 26 months （ranging from 1 to 78 months）. Clinical data were analyzed between the two groups. Results Comparing with the younger group, the elderly group had higher prevalence of coronary artery disease （59.0% vs 24.7%, P=0.001）. There was no significant difference of complication rates between the 2 groups （38.5% vs 31.8%, P=0.54）. Kaplan-Meier analysis showed a similar 5-year survival rate（80.2% vs 89.6%; Log Rank, P=0.31） between the 2 groups. Conclusions Endovascular stent-graft implantation is safe and effective in the treatment of type B aortic dissection for both elderly and younger patients. The procedure-related complication rate seems independent of age .

Clinical features of aortic dissection associated with Takayasu＇s arteritis

Takayasu＇s arteritis （TA） is a chronic and nonspecific in- flammatory vessel disease that involves the aorta and its major branches. TA results in stenosis, occlusion or aneu- rysmal degeneration of large arteries pathologically. Al- though TA is an unusual disease, it is more commonly ob- served to occur in Asian females compared to the general population worldwide. Aortic dissection is a very rare com- plication of TA, and only a limited number of TA cases presenting with aortic dissection have been published so far.

Synthesis of Atrazine-HPCD Inclusion and Its Bioactivity

The inclusion of atrazine with 2-hydroxypropyl-β-cyclodextrin(HPCD) was synthesized by ultrasonic method, and it was characterized by UV, XRD and 1H NMR. The solubility in water and the bioactivity of the inclusion were also studied here. The results indicated that the UV maximum absorption wavelength of the inclusion remained at 223 nm, while its intensity decreased. The XRD peaks of atrazine disappeared, weakened and shifted in the inclusion, and the chemical shift of H-3 and H-5 of cyclodextrin inner cavity led to the upfield. The characterization data showed that the atrazine-HPCD inclusion had already formed. At the same time, the solubility of the atrazineHPCD inclusion in water became 20.08 times as that of atrazine. Moreover, the atrazine-HPCD inclusion had better herbicidal activity. When the concentration of the inclusion was 6.5 mg/mL, the inhibition ratios of the inclusion to taproot length, taproot fresh weight, sprout length and sprout fresh weight of barnyard grass were 66.96%, 57.22%, 70% and 57.53%, respectively, which were all higher than those of atrazine.

Induction of thoracic aortic dissection: a mini-review of β-aminopropionitrile-related mouse models

Thoracic aortic dissection(TAD)is one of the most lethal aortic diseases due to its acute onset,rapid progress,and high rate of aortic rupture.The pathogenesis of TAD is not completely understood.In this mini-review,we introduce three emerging experimental mouse TAD models usingβ-aminopropionitrile(BAPN)alone,BAPN for a prolonged duration(four weeks)and then with added infusion of angiotensinⅡ(AngⅡ),or co-administration of BAPN and AngⅡchronically.We aim to provide insights into appropriate application of these three mouse models,thereby enhancing the understanding of the molecular mechanisms of TAD.

Variants of genes encoding collagens and matrix metalloproteinase system increased the risk of aortic dissection

Aortic dissection （AD） is a devastating, heterogeneous condition of aorta. The homeostasis between collagens and matrix metalloproteases （MMPs）/tissue inhibitors of MMPs （TIMPs） system in the extracellular matrix plays an important role for structure and functions of aorta. However, our knowledge on association between variants of genes in this system and pathogenesis of AD is very limited. We analyzed all yet known coding human genes of collagens （45 genes）, MMPs/TIMPs （27 genes） in 702 sporadic AD patients and in 163 matched healthy controls, by using massively targeted next-generation and Sanger sequencing. To define the pathogenesis of potential disease-causing candidate genes, we performed transcriptome sequencing and pedigree co-segregation analysis in some genes and generated Col5a2 knockout rats. We identified 257 pathogenic or likely pathogenic variants which involved 88.89% （64/72） genes in collagens-MMPs/TIMPs system and accounted for 31.05% （218/702） sporadic AD patients. In them, 84.86% patients （185/218） carried one variant, 12.84% two variants and 2.30% more than two variants. Importantly, we identified 52 novel probablY pathogenic loss-of-function （LOF） variants （20 nonsense, 16 frameshift, 14 splice sites, one stop-loss, one initiation codon） in 11.06% （50/452） AD patients, which were absent in 163 controls （P=2.5-10-5）. Transcriptome sequencing revealed that identified variants induced dyshomeostasis in expression of collagens-TIMPs/MMPs systems. The Col5a2-/- rats manifested growth retardation and aortic dysplasia. Our study provides a first comprehensive map of genetic alterations in collagens-MMPs/TIMPs system in sporadic AD patients and suggests that variants of these genes contribute largely to AD pathogenesis.

A disintegrin and metalloproteinase with thrombospondin motif 1(ADAMTS1) expression increases in acute aortic dissection

Acute aortic dissection(AAD) is a life-threatening cardiovascular disease caused by progressive medial degeneration of the aortic wall. A disintegrin and metalloproteinase with thrombospondin motifs 1(ADAMTS1) is a recently identified extracellular metalloproteinase participating in the development of vascular disease, such as atherosclerosis. In the present study, we found that ADAMTS1 was significantly elevated in blood samples from AAD patients compared with patients with acute myocardial infarction and healthy volunteers. Based on these findings, we established an AAD model by infusing angiotensin II in older mice. AAD was successfully developed in aorta tissues, with an incidence of 42% after 14 days in the angiotensin II group. Macrophage and neutrophil infiltration was observed in the media of the aorta, and ADAMTS1 overexpression was found in the aorta by Western blot and immunohistochemistry. Double immunofluorescence staining showed the expression of ADAMTS1 in macrophages and neutrophils. Consistent with the upregulation of ADAMTS1 in aortic dissection tissues, versican(a proteoglycan substrate of ADAMTS1) was degraded significantly more in these tissues than in control aortic tissues. These data suggest that the increased expression of ADAMTS1 protein in macrophages and neutrophils that infiltrated aortic tissues may promote the progression of AAD by degrading versican.

Dynamic modeling and H_∞ independent modal space vibration control of laminate plates

In this paper, combining the transfer matrix method and the finite element method, the modified finite element transfer matrix method is presented for high efficient dynamic modeling of laminated plates. Then, by constructing the modal filter and the disturbance force observer, and using the feedback and feedforward approaches, the H ∞ independent modal space control strategy is designed for active vibration control of laminate plates subjected to arbitrary, immeasurable disturbance forces. Compared with ordinary dynamic modeling and control methods of laminated plate structures, the proposed method has the low memory requirement, high computational efficiency and robust control performance. Formulations as well as some numerical examples are given to validate the method and the control performance.