Inverse Analysis of Impact Test Data: Experimental Study on Polymeric Materials Displaying Brittle Behaviour

This paper deals with the influence of the testing equipment on impact load measurements. A previously developed method of analysis and processing of the experimental data based on a refined analogical model of the impact event and inverse problem techniques is used. This method makes it possible to obtain the mechanical response of the material, notwithstanding the disturbance of the dynamic effects associated to the test. Results from tests carried out both on falling weight and swing pendulum instrumented testing machines are compared. It is shown that this method can give an accurate estimation of the actual bending force in impact testing independent of the testing equipment.     

新型多苯并咪唑环芳识别氨基酸甲酯的分子动力学和密度泛函研究

采用Gaussian 03在B3LYP/6-31G(d)水平上分别优化新型多苯并咪唑环芳(MBICP)受体和氨基酸甲酯(AAME)配体,再用基于模拟退火的分子动力学方法 CDOCKER将配体与受体对接,对每一个复合物获得了一组最低能量的初始构象。最后用Turbomole在BLYP/def-TZVP水平对初始构象进一步优化,并对收敛后的复合物最低能量构象作NBO分析。以密度泛函理论计算获得的相互作用能作为核心参数,采用组合策略建立了表达MBICP-AAME复合物结合常数的定量关系模型,计算了该类复合物的结合常数。对MBICP受体和AAME配体间的作用模式以及影响MBICP受体识别AAME配体的主要因素,作了深入讨论。     

Dietetic study of pregnant women of Santa Maria Cauqué, Guatemala. I. Variability of protein indicators and analysis by the time of meals

The distribution of the protein energy ratio indicators (Pe%), amino acid score and protein value (NDpCal%) in the three daily meals (breakfast, lunch and dinner) of the diet of pregnant women from Santa María Cauqué, Guatemala, was studied. The results were compared with those obtained for the total daily food intake. The differences observed were not significant, confirming the validity of the determination of amino acid score, Pe% and NDpCal% in the foods consumed during the whole day in this type of populations. It also reflects the nutritional benefit of the food pattern, since protein utilization would not be decreased by a different distribution of protein quality and concentration throughout the three daily meals. The variability among individuals of Pe% intake, amino acid score and NDpCal% gave the following values: 16.0, 9.3 and 15.6, respectively. It is noteworthy to add that the variability of Pe% observed is similar to that reported for populations of developed countries.     

Elastic behaviour of polyvinyl chloride melts

A study has been made of the elastic behaviour of Polyvinylchloride commercial samples at high shear stresses, under similar conditions to those used in the processing industry, by means of an extrusion capillary rheometer.The influence in the die swell of variables as molecular weight, temperature and shear rate has been studied. Results are in agreement with general literature data.Smooth extrudates are obtained only in the zone of intermediate shear rates. In this zone it is observed that the die swell increases with shear rate.     

Forecasting with unequally spaced data by a functional principal component approach

The Principal Component Regression model of multiple responses is extended to forccast a continuous-time stochastic process. Orthogonal projection on a subspace of trigonometric functions is applied in order to estimate the principal components using discrete-time observations from a sample of regular curves. The forecasts provided by this approach are compared with classical principal component regression on simulated data.     

Near-Complete Remission of Glioblastoma in a Patient Treated with an Allogenic Dendritic Cell-Based Vaccine: The Role of Tumor-Specific CD4+T-Cell Cytokine Secretion Pattern in Predicting Response and Recurrence

Immunotherapy has brought hope to the fight against glioblastoma, but its efficacy remains unclear. We present the case of CST, a 25-year-old female patient with a large right-hemisphere glioblastoma treated with a dendritic–tumor cell fusion vaccine. CST showed a near-complete tumor response, with a marked improvement in her functional status and simultaneous increases in tumor-specific CD8+ and CD4+ T cells. Two months before recurrence, the frequency of tumor-specific T cells decreased, while that of IL-17 and CD4+ T cells increased. CST passed away 15 months after enrollment. In this illustrative case, the tumor-specific CD4+ T-cell numbers and phenotype behaved as treatment efficacy biomarkers, highlighting the key role of the latter in glioblastoma immunotherapy.     

Exposure of Mice to Thirdhand Smoke Modulates In Vitro and In Vivo Platelet Responses

Smoking is a risk factor for a variety of deleterious conditions, such as cancer, respiratory disease and cardiovascular disease. Thrombosis is an important and common aspect of several cardiovascular disease states, whose risk is known to be increased by both first- and secondhand smoke. More recently, the residual cigarette smoke that persists after someone has smoked (referred to as thirdhand smoke or THS) has been gaining more attention, since it has been shown that it also negatively affects health. Indeed, we have previously shown that 6-month exposure to THS increases the risk of thrombogenesis. However, neither the time-dependence of THS-induced thrombus formation, nor its sex dependence have been investigated. Thus, in the present study, we investigated these issues in the context of a shorter exposure to THS, specifically 3 months, in male and female mice. We show that the platelets from 3-month THS-exposed mice exhibited enhanced activation by agonists. Moreover, we also show that mice of both sexes exposed to THS have decreased tail bleeding as well as decreased thrombus occlusion time. In terms of the role of sex, intersex disparities in thrombus development and hemostasis as well as in platelet aggregation were, interestingly, observed. Together, our findings show that exposing mice to THS for 3 months is sufficient to predispose them to thrombosis; which seems to be driven, at least in part, by an increased activity in platelets, and that it does not manifest equally in both sexes.     

Improvement of Glycaemia and Endothelial Function by a New Low-Dose Curcuminoid in an Animal Model of Type 2 Diabetes

Curcumin has been suggested as a promising treatment for metabolic diseases, but the high doses required limit its therapeutic use. In this study, a new curcuminoid is synthesised to increase curcumin anti-inflammatory and antioxidant potential and to achieve hypoglycaemic and protective vascular effects in type 2 diabetic rats in a lower dose. In vitro, the anti-inflammatory effect was determined through the Griess reaction, and the antioxidant activity through ABTS and TBARS assays. In vivo, Goto-Kakizaki rats were treated for 2 weeks with the equimolar dose of curcumin (40 mg/kg/day) or curcuminoid (52.4 mg/kg/day). Fasting glycaemia, insulin tolerance, plasma insulin, insulin signalling, serum FFA, endothelial function and several markers of oxidative stress were evaluated. Both compounds presented a significant anti-inflammatory effect. Moreover, the curcuminoid had a marked hypoglycaemic effect, accompanied by higher GLUT4 levels in adipose tissue. Both compounds increased NO-dependent vasorelaxation, but only the curcuminoid exacerbated the response to ascorbic acid, consistent with a higher decrease in vascular oxidative and nitrosative stress. SOD1 and GLO1 levels were increased in EAT and heart, respectively. Altogether, these data suggest that the curcuminoid developed here has more pronounced effects than curcumin in low doses, improving the oxidative stress, endothelial function and glycaemic profile in type 2 diabetes.     

Structural Abnormalities of the Optic Nerve and Retina in Huntington’s Disease Pre-Clinical and Clinical Settings

Huntington’s disease (HD) is a fatal neurodegenerative disorder caused by a polyglutamine expansion in the huntingtin protein. HD-related pathological remodelling has been reported in HD mouse models and HD carriers. In this study, we studied structural abnormalities in the optic nerve by employing Spectral Domain Optical Coherence Tomography (SD-OCT) in pre-symptomatic HD carriers of Caucasian origin. Transmission Electron Microscopy (TEM) was used to investigate ultrastructural changes in the optic nerve of the well-established R6/2 mouse model at the symptomatic stage of the disease. We found that pre-symptomatic HD carriers displayed a significant reduction in the retinal nerve fibre layer (RNFL) thickness, including specific quadrants: superior, inferior and temporal, but not nasal. There were no other significant irregularities in the GCC layer, at the macula level and in the optic disc morphology. The ultrastructural analysis of the optic nerve in R6/2 mice revealed a significant thinning of the myelin sheaths, with a lamellar separation of the myelin, and a presence of myelonoid bodies. We also found a significant reduction in the thickness of myelin sheaths in peripheral nerves within the choroids area. Those ultrastructural abnormalities were also observed in HD photoreceptor cells that contained severely damaged membrane disks, with evident vacuolisation and swelling. Moreover, the outer segment of retinal layers showed a progressive disintegration. Our study explored structural changes of the optic nerve in pre- and clinical settings and opens new avenues for the potential development of biomarkers that would be of great interest in HD gene therapies.