Amyotrophic lateral sclerosis (ALS) is a rare degenerative condition of the motor neurons. Over 10% of ALS cases are linked to monogenic mutations, with the remainder thought to be due to other risk factors, including environmental factors, genetic polymorphisms, and possibly gene-environmental interactions. We examined the association between ALS and an intermediate CAG repeat expansion in the ATXN2 gene using a meta-analytic approach. Observational studies were searched with relevant disease and gene terms from MEDLINE, EMBASE, and PsycINFO from January 2010 through to January 2014. All identified articles were screened using disease terms, gene terms, population information, and CAG repeat information according to PRISMA guidelines. The final list of 17 articles was further evaluated based on the study location, time period, and authors to exclude multiple usage of the same study populations: 13 relevant articles were retained for this study. The range 30–33 CAG repeats in the ATXN2 gene was most strongly associated with ALS. The meta-analysis revealed that the presence of an intermediate CAG repeat (30-33) in the ATXN2 gene was associated with an increased risk of ALS [odds ratio (OR) = 4.44, 95%CI: 2.91–6.76)] in Caucasian ALS patients. There was no significant difference in the association of this CAG intermediate repeat expansion in the ATXN2 gene between familial ALS cases (OR = 3.59, 1.58–8.17) and sporadic ALS cases (OR = 3.16, 1.88–5.32). These results indicate that the presence of intermediate CAG repeat expansion in the ATXN2 gene is a specific genetic risk factor for ALS, unlike monogenic mutations with an autosomal dominant transmission mode, which cause a more severe phenotype of ALS, with a higher prevalence in familial ALS.
To optimize the design of RC frames with special-shaped columns, some special care should be given to the design of this type of structure. Designers should attach great importance to concept design by considering the structure as a whole to assimilate seismic energy. Ductility has to be guaranteed both for the structure and for the members. In high-rise buildings, frame-shear wall structure is preferred. Safety of L-shaped Corner columns is to be improved or otherwise cantilever beams can be designed to prevent progressive collapse.
With the SMA (Shape Memory Alloy) banner model, the effect of pre-stressing and displacement, stiffness and length to the energy dissipation ratio is studied. The two equations, which are of pre-stressing and displacement to the energy dissipation ratio are proposed. The method are put forward to confirm the stiffness and length of SMA . Based on the above analysis, a new pull-press SMA damper is designed. The simulation analysis on seismic response of five-floor frame with SMA damper shows that the displacement and acceleration of the top floor are reduced by 50﹪at least. It verifies that this kind of SMA damper can availably suppress the seismic response of structure.
To increase the bearing capacity of piles, the protruding technique proves to be both reliable and effective. The spiral protruding pile is a variation of this kind that can be applied to dry soil conditions. A practical formula is proposed for designing spiral protruding multi-disk cast-in-place piles. Also illustrated here is the project in which spiral protruding piles were applied with great success in terms of techniques and costs, while its unique advantages under certain conditions can be viewed. The paper aims to provide solid basis for research, design and further application of this type of pile.
A series of novel sulfonated poly(arylene ether sulfone) (SPAES) copolymers were successfully synthesized from hexafluoro bisphenol A (6F-BPA), 9,9’-bis(4-hydroxyphenyl) fluorene (BHPF), 4,4’-difluorodiphenyl sulfone (DFDPS) and 3,3’-disulfonate-4,4’-difluorodiphenyl sulfone (SDFDPS) via aromatic nucleophilic substitution polymerization, and subsequently used to prepare proton exchange membranes. By adjusting the ratio of 6F-BPA to BHPF, the influence of the rigidity of polymer backbone on the properties of the prepared membranes was investigated in detail. The results indicated that the SPAES membranes had better stability towards water but lowered water uptake and proton conductivity with the increase in the polymer backbone rigidity.
Based on a real project, this paper presents the design of a space steel pipe truss with a triangular cross section upside down, in which it covers the selection of structure type, arrangement of the structure, loads and load combination, structural analysis as well as the detailing of some major joints. Thus it can serve as a reference for the design of similar large-span trusses.
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