Does project-based learning enhance Iranian EFL learners’ vocabulary recall and retention?

Vocabulary knowledge is an integral part of second/foreign language learning. Thus, using teaching methods that can help learners retain and expand their vocabulary knowledge is necessary to facilitate the language learning process. The current research investigated the effectiveness of an interactive classroom method, known as Project-Based Learning (PBL), in helping Iranian EFL learners not just learn but retain new vocabulary knowledge. To this end, an experimental approach using two groups of participants (i.e. experimental and control) was employed. The experimental group was taught using the PBL method while the control group was taught using the conventional method. The findings of the study indicated that learners who were taught using the PBL approach (i.e. the experimental group) had a significant improvement in their vocabulary recall and retention rate. Besides, they even showed better retention of new vocabulary with higher level of difficulty. This supports previous findings on the effectiveness of PBL as a vocabulary teaching method in the EFL context which could contribute to the betterment of the existing teaching methods

An Investigation on the Regenerative Effects of Intra Articular Injection of Co-Cultured Adipose Derived Stem Cells with Chondron for Treatment of Induced Osteoarthritis

Purpose: Adipose tissue derived stem cells (ASCs) and chondrocytes are best cells for articular cartilage regeneration. Chondrocyte with peri-cellular matrix (PCM) is called chondron provides ideal microenviroment than chondrocytes. We aimed to evaluate the regenerative effects of intra-articular injection of ASCs co-cultures with chondron in induced osteoarthritis (OA). Methods: ASC, from the peri-renal fat of male rat and chondron from primary newborn rat hyaline cartilage were isolated. ASCs were cultured for at least three passages in vitro. Six weeks after OA induction, rats were randomly distributed in five groups of control, osteoarthritic, ASC, chondron and co-cultured. ASCs (107), chondrons (107) and combination of chondrons and ASCs (107) were injected into intra-articular space of the rat knee. The effect of treatments was evaluated by macroscopic and microscopic examinations. The expression levels of collagen type ΙΙ was studied by immunohistochemistry. Results: Macroscopic appearance of the co-cultured group, showed much enhanced articular cartilage regeneration compared to ASC and chondron groups. H&E showed evidence of repair site of articular surface without erosion and fibrillation versus OA group which showed thin layer of hyaline cartilage over tidemark and spontaneous fibrocartilage formation. Metachromatic regions stained with toluidine blue were larger in treatment groups versus OA group. Strong intensity of type ΙΙ collagen staining was observed in co-culture group compared to other groups. Conclusion: Co-culture of chondrons and ASCs increased articular hyaline cartilage formation and provides a useful tool to improve limitations of each of applied cells in this model

Does project-based learning enhance Iranian EFL learners’ vocabulary recall and retention?

Vocabulary knowledge is an integral part of second/foreign language learning. Thus, using teaching methods that can help learners retain and expand their vocabulary knowledge is necessary to facilitate the language learning process. The current research investigated the effectiveness of an interactive classroom method, known as Project-Based Learning (PBL), in helping Iranian EFL learners not just learn but retain new vocabulary knowledge. To this end, an experimental approach using two groups of participants (i.e. experimental and control) was employed. The experimental group was taught using the PBL method while the control group was taught using the conventional method. The findings of the study indicated that learners who were taught using the PBL approach (i.e. the experimental group) had a significant improvement in their vocabulary recall and retention rate. Besides, they even showed better retention of new vocabulary with higher level of difficulty. This supports previous findings on the effectiveness of PBL as a vocabulary teaching method in the EFL context which could contribute to the betterment of the existing teaching methods

The effect of pulp and seed extract of Citrullus Colocynthis, as an antidaibetic medicinal herb, on hepatocytes glycogen stores in diabetic rabbits

Background : Medicinal herbs such as Citrullus Colocynthis (C.C) have been used traditionally in the treatment of diabetes mellitus. However therapeutic applications and adverse effects of C.C and its natural variants are not determined well. The current work investigates the effects of pulp and seed extract of C.C on hepatocyte′s glycogen stores. Materials and Methods : Thirty six male rabbits were divided into six groups (control and diabetic) randomly. Alloxan was used in order to induce diabetes mellitus in animals. Among 5 diabetic groups, one remained as control and the rest received 100 and 200 mg/kg/day of either pulp or seed extract. One month later, animals were sacrificed and their liver specimen fixed in 10% Formalin was stained with periodic acid schiff (PAS) for light microscopic scanning. Results : PAS staining of hepatocytes revealed large amounts of glycogen stores in diabetic animals treated with pulp and seed extracts of C.C, contrary with non-treated diabetic rabbits. Sites of glycogen deposition were also different in animals treated with seed extract (P < 0.0001). No hepatic congestion was seen in treated animals. Dose escalation has no effect on the obtained results. Conclusions : The anti-diabetic effects of C.C can be explained by its effects on accumulation of glycogen stores in hepatocytes. The importance of varied sites of glycogen deposition by the application of C.C needs to be determined

Advantages of Sheep Infrapatellar Fat Pad Adipose Tissue Derived Stem Cells in Tissue Engineering

Purpose: The goal of this study has been to evaluate adipose tissue derived stem cells (ADSCs) from infrapatellar fat pad and characterize their cell surface markers using anti-human antibodies, as adipose tissue derived stem cells (ADSCs) have great potential for cellular therapies to restore injured tissues. Methods: Adipose tissue was obtained from infrapatellar fat pad of sheep. Surface markers evaluated by flow cytometry. In order to evaluate cell adhesion, the Polycaprolactone (PCL) was sterilized under Ultraviolet (UV) light and about 1×105 cells were seeded on PCL. Then, ASCs- PCL construct were evaluated by Scanning Electron Microscopy (Mira3 Te Scan, Czech Republic). Results: We showed that adipose tissue derived stem cells (ADSCs) maintain their fibroblastic-like morphology during different subcultures and cell adhesion. They were positive for CD44 and CD90 markers and negative for CD31 and Cd45 markers by human antibodies. Conclusion: Our results suggest that ASCs surface markers can be characterized by anti-human antibodies in sheep. As stem cells, they can be used in tissue engineering

Study of chondrogenic potential of stem cells in co-culture with chondrons

Objective(s): Three-dimensional biomimetic scaffolds have widespread applications in biomedical tissue engineering due to similarity of their nanofibrous architecture to native extracellular matrix. Co-culture system has stimulatory effect on chondrogenesis of adult mesenchymal stem cells. This work presents a co-culture strategy using human articular chondrons and adipose-derived stem cells (ASCs) from infrapatellar fat pad (IPFP) for cartilage tissue production. Materials and Methods: Isolated stem cells were characterized by flowcytometry. Electrospun and polycaprolactone (PCL) scaffolds (900 nm fiber diameter) was obtained from Bon Yakhteh (Tehran- Iran) and human infrapatellar fat pad-derived stem cells (IPFP-ASCs) were seeded on them. IPFP- ASCs on scaffolds were co-cultured with articular chondrons using transwell. After 21 day, chondrogenic differentiation of stem cell was evaluated by determining the genes expression of collagen2, aggrecan and Indian hedgehog using real- time RT-PCR. Results: Genes expression of collagen2, aggrecan by IPFP-ASCs did not alter significantly in comparison with control group. Howevers, expression of Indian hedgehog decreased significantly compared to control group (P˂ 0.05). Conclusion: These findings indicate that chondrons obtained from osteoarthritic articular cartilage did not stimulate chondrogenic differentiation of IPFP-ASCs in co-culture

Optimizing a novel method for low intensity ultrasound in chondrogenesis induction

Background: Hyaline cartilage tissue of joints is susceptible to injuries due to avascularity. Mesenchymal stem cells (MSCs) are used for cartilage tissue engineering. Among MSCs, adipose stem cells (ASCs) are attractive because of accessibility, their large number, and rapid growth. Common in vitro protocols successfully induce chondrogenic differentiation by expression of multiple cartilage-specific molecules. However, transforming growth factor β (TGFβ) promotes chondrogenesis to terminal stages. Despite much attention being given to the influences of biochemical factors on chondrogenesis of MSCs, few studies have examined the chondrogenic effect of mechanical factors such as ultrasound as a feasible tool. Materials and Methods: In this study, we focused on inducing chondrogenesis in the early stages of differentiation by using low-intensity ultrasound (LIUS). Four groups of ASC pellets (control, ultrasound, TGFβ, and ultrasound/TGF) were cultured under chondrogenic (10 ng/ml of TGFβ3) and ultrasound conditions (200 mW/cm 2 , 10 min/day). After 2 weeks, differentiation was evaluated by histology, quantitative gene expression analysis, and immunohistochemistry. Results: Our data demonstrated that ultrasound differentiated pellets showed increased expression of early chondrogenesis marker, Col2A, than those in TGFβ groups (P < 0.001), and Col2B and Col10 expression were more prominent in TGFβ groups. Immunostaining of sections showed Col2 fibrils around lacuna in LIUS and TGFβ treated groups. Conclusion: Using LIUS resulted in early chondrogenesis in comparison with terminally differentiated chondrocytes by TGFβ. Therefore, LIUS might provide an applicable, safe, efficient, and cheap tool for chondrogenic differentiation of ASCs in cartilage tissue engineering