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Background and Objective: Research have been focused on the applying the chemical inducer for trans-differentiation the adult BMSCs into neural cell. So that, at the first should investigate the toxcity effect of the chemical inducer on the induced cells. Plasticity and easy accessibility of bone marrow mesenchymal stem cells is a unique charactristic for treatment of neural disorderies. This study was desgined to determine the inductive effect of Deprenyl and Dimethyl sulfoxide on proliferation and survival of the mesenchymal stem cells. Materials and Methods: In this experimental study, BMSCs isolated from the adult rat bone marrow and cultured in αMEM containing 10% FBS. Cell identity for surface antigens was performed in third passage by immunocytochemistry and multipotancy capacity of BMSCs was done by BMSC differentiation into adipocytes and osteocytes. The cells were exposed to chemical agents (a: the αMEM medium supplemented with 2% DMSO, b: the αMEM medium supplemented with 10-8M Deprenyl) for 24 houres and then transferred to αMEM containing 10% FBS cell survival and proliferation was evaluated after the 24, 48, 72 and 96 houres by MTT [3-(4-5-Dimethylthiazolyl-2-y1)-2,5-diphenyltetrazolium bromid] test. Data were analyzed using SPSS-16, One-Way ANOVA and Tukey tests. Results: In addition to expression the surface antigens and adipogenic and osteogenic differentiation by BMSCs, MTT test results showed that proliferation and survival of induced-deprenyl and DMSO cells within 48, 72 and 96 hours after the induction was increased significantly than negative control group. Conclusion: Deprenyl increases survival and cell proliferation compared to Dimethyl Sulfoxide. It can be used as cell inducer.

Background: Spinal anesthesia can be associated with hemodynamic changes and some other complications. The aim of this study was to evaluate the effect of adding fentanyl to lidocaine on the spinal anesthesia time and its complications for cesarean section.Methods: Sixty pregnant women with gestational age of 37- 42 weeks and ASA physical status I and II undergoing elective cesarean section under spinal anesthesia were enrolled in a randomized double blinded clinical trial. They were randomly allocated to receive spinal anesthesia with lidocaine-normal saline (LS: 75 mg lidocaine 5% with 0.3 ml normal saline) lidocaine-fentanyl (LF) group (75 mg lidocaine 5% with 50 μg fentanyl). The duration of initiation of sensory block to achieve T4 level, time to return of sensory level to T12, time to first analgesic request, ephedrine requirement, nausea and vomiting during and after the surgery, pruritus, respirator depression, headache and apgar score of the new born at 1st and 5th minutes were assessed. Results: There was no significant difference between time to achieve T4 level, ephedrine dose, post operative nausea and vomiting (PONV), pruritus and headache in study groups. Time to return of sensory level to T12 was significantly longer in LF group (152.6±14.7 vs. 66.2±11.2 min, P=0.0009). Time to first analgesic request was also longer in LF group (164.2±20.8 vs. 68.1±11.3 min, P=0.0009). The incidence of nausea and vomiting during surgery was significantly more in LF group (20% vs. 0%, P=0.023). No case of respiratory depression was observed in groups. The 1st and 5th minute's apgar score were comparable between groups and were between 7 and 10.Conclusions: Addition of fentanyl to intrathecal lidocaine in patients undergoing elective cesarean section results in increasing of the block duration and time to first analgesic request without significant maternal or neonatal side-effects, without effect on 1st and 5th minutes apgar score with increasing the incidence of during surgery nausea and vomiting.

Cortical lesions can cause major sensory and motor impairments, representing a significant challenge in neuroscience and clinical medicine. Limbal mesenchymal stem cells (LMSCs), renowned for their remarkable ability to proliferate and distinct characteristics within the corneal epithelium, offer a promising opportunity for regenerative treatments. This study aimed to assess whether the transplantation of LMSCs could improve tactile ability in rats with lesions of the barrel cortex.

The selection of a crashworthy core for sandwich composite construction has been aimed pursued in various applications. In this article, the response of sandwich beams consisting of elastomeric foam core and laminated fibre-reinforced skins with various layup sequences hereafter referred to as (EFCS) beams is investigated experimentally and numerically. This sandwich configuration provides several advantages for structural applications since the conventionally used rigid foam cores have relatively low crushing strength. The incorporation of the elastomeric foam has been found to enhance the post-failure stability and residual strength/crashworthiness of sandwich composite beams due to the pacifying influence of the core on the failure mechanism, which was further examined by numerical simulations. Both the hyperelasticity of the foam core and the progressive damage of the composite skins were accounted for in the numerical simulation. The efficiency of EFCS beams was established by comparing their performance to their laminated composite counterparts. The results evidence the promising performance of EFCS beams, especially in the context of their residual strength, which could be as high as 70% of their ultimate strength, as well as their enhancing energy absorption capacity. Furthermore, the performances of EFCS beams with angle-ply laminated skins were also examined numerically. The results reflect more advantage of using laminated skins with some specific fibre orientations. [ABSTRACT FROM AUTHOR]

Analytical and experimental investigation into dynamic properties of glued-laminated (glulam) beams reinforced with various lay ups of e-glass reinforced epoxy polymer (GRP) composites are discussed. Three unreinforced glulam (control) beams and 11 glulam beams reinforced with GRP on their bottom surface were clamped in a cantilever condition and tested using an instrumental hammer. The natural frequencies of all beams determined by the impact dynamic (hammer) method using power spectral density (PSD) were used to estimate damping ratio of all the beams through both time domain and frequency domain methods. In the time domain analysis, the method of logarithmic decrement analysis (LDA) and the Hilbert transform analysis (HTA) were considered; in the frequency domain analysis, both moving block analysis (MBA) and half-power bandwidth (HPB) were applied to the data and a new approach HPB method with a polynomial correction function was numerically established. A comparison between the results obtained from all the methods of analysis and a new approach shows that this method may improve the accuracy of the HPB method in evaluation of vibration damping properties of glulam reinforced composite beams because glulam beams have high level damping ratios and that this method should be modified especially when used with materials having high level damping ratios. Key words: damping, half-power bandwidth (HPB) method, glulam beams, reinforcement, e-glass reinforced epoxy polymer (GRP) composites. L'examen analytique et experimental des proprietes dynamiques des poutres lamellees-collees renforcees de diverses couches de composes polymeres epoxy renforces de verre E (PRV) est aborde. Trois poutres lamellees-collees non renforcees (reference) et onze poutres lamellees-collees renforcees de PRV sur leur face inferieure ont ete serrees en position de porte-a-faux puis mises a l'epreuve en utilisant un marteau instrumente. Les frequences naturelles de toutes les poutres, determinees par la methode d'impact dynamique (marteau) utilisant la densite spectrale de puissance, ont ete utilisees pour estimer le rapport d'amortissement de toutes les poutres par les methodes du domaine temps et des frequences. Dans l'analyse du domaine temps, la methode d'analyse par decrement logarithmique (<< LDA >>) et l'analyse de la transformee de Hilbert (<< HTA >>) ont ete utilisees. Dans l'analyse du domaine des frequences, l'analyse par blocs mobiles (<< MBA >>) et la largeur a demi-puissance (<< HPB >>) ont ete appliquees aux donnees et une nouvelle approche de la methode << HPB >> avec une fonction de correction polynomiale a ete determinee numeriquement. Une comparaison entre les resultats obtenus de toutes les methodes d'analyse et la nouvelle methode montre que cette nouvelle approche peut ameliorer la precision de la methode << HPB >> dans l'evaluation des proprietes d'amortissement des vibrations des poutres lamellees-collees composites renforcees puisque les poutres lamellees-collees presentent un haut rapport d'amortissement et que cette approche devrait etre modifiee, particulierement lorsqu'elle est utilisee avec des materiaux d'amortissement de haut niveau. Mots-cles: amortissement, largeur a demi-puissance methode (<< HPB >>), poutres lamellees-collees, renforcement, poutres lamellees-collees renforcees (PRV). [Traduit par la Redaction], 1. Introduction Glued-laminated (glulam) wood can be fabricated in many shapes and sizes for use in various structural applications such as bridge girders, beams and arches in large building and [...]

A systematic experimental investigation was conducted to evaluate the damping ratios of uureinforced glulam beams, and glulam beams reinforced with E-glass reinforced epoxy polymer (GRP) plates. The methods considered were the logarithmic decrement, the Hilbert transform, the moving block, and the half band power (HBP) methods. A modification to the HPB method is proposed to improve the method's accuracy when considering materials with relatively high damping ratios. The influence of the lay up sequence, thickness, and through-the-depth location of the GRP plate on damping of the composite beams is also investigated. The results obtained from our experimental and numerical investigations show that the proposed modification to the HPB method could effectively improve the accuracy of the method when considering the vibration damping of composite materials possessing relatively high level of damping. DO/: 10. 1061/(ASCE)0733-9445(2005) 131:7(1044) CE Database subject headings: Damping: Glue laminated materials: Vibration: Beams.

Uncontrolled vibration in mechanical systems (e.g. aircraft, trains, and automobiles) may result in undesirable noise and eventually, cause mechanical failure. In this context, the main objective of the present research is to explore parameters that govern and affect the frequency response of three-dimensional fiber metal laminates. Three-dimensional fiber metal laminates are a class of novel lightweight hybrid material systems with great potential for use in aforementioned applications. Therefore, the vibration characteristics of the two most commonly used configurations of three-dimensional fiber metal laminates are experimentally investigated by nontraditional and conventional approaches. Material damping is also improved by the inclusion of two different types of nanocarbon particles within the core and/or interfaces of the hybrid system. The results are presented and compared. The inclusion of nanocarbon particle improved the fundamental frequency of the system slightly; however, material damping was enhanced significantly when only 1 wt% nanocarbon particle was used in the interfacial sections of the system. [ABSTRACT FROM AUTHOR]