Cholinergic and anticholinesterase activities of total protein extract of Morinda morindoïdes on isolated rabbit duodenum

Traditional herbal medicines such as Morinda morindoïdes are used for treatment of intestinal disorders including constipation in Ivory Coast. The aim of present study was to investigate the effect of total protein of Morinda morindoïdes extract (PT-Mm) on rabbit duodenum contractility and the involved possible mechanism(s). PT-Mm was extracted according to the saturation method of Dawson with ammonium sulfate. The cholinergic effect of the extract was determined by the in vitro organ bath method. The acetylcholinesterase (AChE) extracted from rabbit duodenum and it activity was determined by Ellman’s assay using acetylthiocholine (ASCh) as substrate. PT-Mm concentrations (40, 80, 120 and 200 μg/mL) showed dose-dependent effect a both tonicity and amplitude of the duodenum spontaneous contractions. The effective concentration which induces 50% effect of PT-Mm (EC50) was obtained with 68.57 ± 0.89 μg/mL. The antagonist tests carried out showed a considerable reduction (90%) in the amplitudes of duodenal contractions in the presence of atropine, but with nifedipine, the contractions were completely inhibited. PT-Mm also exerted non-competitive inhibition on AChE (Vmax = 5687 mM/min and KM = 578 μM). These results suggest that PT-Mm could stimulate duodenum smooth muscle contraction because it contains anti-AChE and cholinomimetic substances which, through muscarinic receptors, increase Ca2+ mobilization from extracellular. Therefore, PT-Mm could be used as a laxative, due to its stimulating effects on duodenal contractility.Keywords: Morinda morindoides, acetylcholinesterase, duodenum, contractio

Material and structural behaviour of PMMA from low temperatures to over the glass transition: Quasi-static and dynamic loading

This work aims at characterizing the mechanical behaviour of polymethyl-methacrylate (PMMA) under high velocity impact conditions over a wide range of testing temperatures. To this end, the mechanical response at uniaxial compression is studied for both quasi-static and dynamic conditions covering testing temperatures below, at and above glass transition. A pseudo-brittle to ductile transition in the failure of PMMA is observed at a threshold that depends on testing temperature and strain rate. This analysis allows for the interpretation of the perforation impact tests and to explain the principal deformation and failure mechanisms. To complete the study, the Richeton model to predict yielding is revisited. Finally, we provide a new constitutive model for finite deformations to further identify the deformation mechanisms governing the mechanical behaviour of PMMA and the influence of temperature and strain rate on them.D. Garcia-Gonzalez acknowledges support from the Talent Attraction grant (CM 2018 - 2018-T2/IND-9992) from the Comunidad de Madrid

Sociedade civil e ação política na Costa do Marfim

With the return to the multi-party system, the civil society in the Ivory Coast has presented itself as more vigorous and active than in previous decades. Far from controversies regarding the definition of a civil society, its ‘neutrality’ assures good governance. This article examines the relations between civil society and political action in the Ivory Coast, and shows that this civil society is a space for political socialization, for the selection of political personnel and for the mobilization of public opinion. From this ascertainment, there comes the hypothesis of the interpenetration of ‘civil society’ and ‘political society’.Com o retorno ao multipartidarismo, a sociedade civil marfinense tem se mostrado mais vigorosa e mais ativa do que nas décadas anteriores. Distante das polêmicas sobre a definição da sociedade civil, sua “neutralidade” assegura uma boa governabilidade. Este artigo examina as relações existentes entre sociedade civil e ação política na Costa do Marfim e mostra que esta sociedade civil é um espaço de socialização política, de seleção de pessoal político e de mobilização da opinião pública. Desta constatação, surge a hipótese da interpenetração da “sociedade civil” com a “sociedade política”

Microstructure Evolution in AM Produced Superalloy Thin Struts at Low Plastic Strain

This paper discusses the microstructures and textures that develop in thin struts fabricated in Inconel 718 using laser melting powder bed fusion. Thin struts 1 mm wide were fabricated in the vertical (ZX) and horizontal build (XY) orientations with respect to the build plate. Three distinct regions of well-defined grain structures with centerline symmetry from the outer border to the center of the inner volume were present, which was attributed to the laser scan strategy, consisting of a fill hatch, inner and outer border scan on each 30 m layer. Using ex situ micro-tensile testing and enhanced Back-Scattered Electrons (BSE) and Electron Back Scattered Diffraction (EBSD), the microstructure evolution to a plastic strain near 1%, in both the ZX and XY build direction was studied in the initial undeformed and final deformed states. For the ZX build direction, grain rotation as well as grain boundary migration was observed and was more significant than in the samples fabricated in XY. This paper discusses the evolution of the microstructure offering valuable insights into the relationship between microstructure and mechanical properties in complex AM produced microstructures

Microstructure Effects on the Machinability of AM-Produced Superalloys

This paper discusses the microstructure effects on the machinability of Inconel 718 by conducting machining tests on an additively manufactured (AM) workpiece with a strongly textured grain structure and a wrought workpiece incorporating a finer and more equiaxed grain structure. The AM workpiece was produced as a thin tube using Laser Melting Powder Bed Fusion and optimal processing conditions for this alloy. A lathe was used to conduct instrumented orthogonal machining tests on the two workpiece materials under dry cut and coolant conditions using a semisynthetic emulsion coolant. The process parameters studied were feed from 0.05 to 0.15 mm/rev and cutting speed from 60 to 120 m/min with a cut time of 2 sec duration for each process condition. Measures for each process condition included cutting forces in the feed and main cut direction, and images of chip forms were obtained. The grain structures of the workpiece materials were characterized using Electron Back Scattered Diffraction (EBSD). New findings suggest that grain structures can significantly affect the machinability of the superalloy at a higher feed for all cutting speeds studied, and insights into the cause are discussed. Other important findings comment on the effectiveness of the coolant as a lubricant for reducing friction in machining

Surface performances of Ti-6Al-4V substrates coated PVD multilayered films in biological environments

Multilayered and nanostructured coatings of Ti based alloys (oxides and nitrides) are elaborated and tested for increasing protective properties such as corrosion and wear resistances. A pin-on-disc tribometer was used to evaluate the wear resistance in Hank's solution against bovine bone. Corrosion behavior in Hank's solution was determined by potentiodynamic and electrochemical impedance spectroscopy techniques. Besides, the specimen surfaces were characterized by Atomic Force Microscopy (AFM), Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS) microanalyses. The results showed that optimal tribological properties were obtained in the case of coatings having TiN as top layer. The main wear mechanism was abrasive third body wear. In vitro corrosion tests at 37 °C showed that the better corrosion resistance was obtained when TiN was the top layer. However all of them exhibited good tribological properties, good corrosion resistance and then may be promising options for biomedical applications

Integrating Technical Standards into ET Curricula to Meet ABET Standards and Industry Needs

With technical standards affecting nearly every aspect of our daily lives, from computers to the components and materials used in car engines, it is critical that undergraduate students are educated on the importance of standards and provided with opportunities to locate and apply relevant technical standards to real world situations. In addition, with ABET accreditation requiring students to have a “basic understanding and familiarity with,” and experience “using” codes and standards, faculty need to consider how such material can be naturally integrated into the curriculum. At Purdue University, education about codes and standards has been integrated into the mechanical engineering technology (MET) curriculum for decades with significant success. This paper discusses how standards are incorporated into mechanical design and quality control courses, as well as strategies for integrating standards into more courses in an MET curriculum. In addition, a discussion of standards resources that are freely available is included. Finally, a call to action for industry is presented, explaining the need and potential areas where industry can increase involvement in teaching students about technical standards

Prevalence and onset of comorbidities in the CDKL5 disorder differ from Rett syndrome

Background: Initially described as an early onset seizure variant of Rett syndrome, the CDKL5 disorder is now considered as an independent entity. However, little is currently known about the full spectrum of comorbidities that affect these patients and available literature is limited to small case series. This study aimed to use a large international sample to examine the prevalence in this disorder of comorbidities of epilepsy, gastrointestinal problems including feeding difficulties, sleep and respiratory problems and scoliosis and their relationships with age and genotype. Prevalence and onset were also compared with those occurring in Rett syndrome. Methods: Data for the CDKL5 disorder and Rett syndrome were sourced from the International CDKL5 Disorder Database (ICDD), InterRett and the Australian Rett syndrome Database (ARSD). Logistic regression (multivariate and univariate) was used to analyse the relationships between age group, mutation type and the prevalence of various comorbidities. Binary longitudinal data from the ARSD and the equivalent cross-sectional data from ICDD were examined using generalized linear models with generalized estimating equations. The Kaplan-Meier method was used to estimate the failure function for the two disorders and the log-rank test was used to compare the two functions. Results: The likelihood of experiencing epilepsy, GI problems, respiratory problems, and scoliosis in the CDKL5 disorder increased with age and males were more vulnerable to respiratory and sleep problems than females. We did not identify any statistically significant relationships between mutation group and prevalence of comorbidities. Epilepsy, GI problems and sleep abnormalities were more common in the CDKL5 disorder than in Rett syndrome whilst scoliosis and respiratory problems were less prevalent. Conclusion: This study captured a much clearer picture of the CDKL5 disorder than previously possible using the largest sample available to date. There were differences in the presentation of clinical features occurring in the CDKL5 disorder and in Rett syndrome, reinforcing the concept that CDKL5 is an independent disorder with its own distinctive characteristics