84 research outputs found
3D Printed TCP-Based Scaffold Incorporating VEGF-Loaded PLGA Microspheres for Craniofacial Tissue Engineering
Objective Vascularization is a critical process during bone regeneration/repair and the lack of tissue vascularization is recognized as a major challenge in applying bone tissue engineeringmethods for cranial and maxillofacial surgeries. The aim of our study is to fabricate a vascular endothelial growth factor (VEGF)-loaded gelatin/alginate/β-TCP composite scaffold by 3D printing method using a computer-assisted design (CAD) model. Methods The paste, composed of (VEGF-loaded PLGA)-containing gelatin/alginate/β-TCP in water, was loaded into standard Nordson cartridges and promptly employed for printing the scaffolds. Rheological characterization of various gelatin/alginate/β-TCP formulations led to an optimized paste as a printable bioink at room temperature. Results The in vitro release kinetics of the loaded VEGF revealed that the designed scaffolds fulfill the bioavailability of VEGF required for vascularization in the early stages of tissue regeneration. The results were confirmed by two times increment of proliferation of human umbilical vein endothelial cells (HUVECs) seeded on the scaffolds after 10 days. The compressive modulus of the scaffolds, 98 ± 11 MPa, was found to be in the range of cancellous bone suggesting their potential application for craniofacial tissue engineering. Osteoblast culture on the scaffolds showed that the construct supports cell viability, adhesion and proliferation. It was found that the ALP activity increased over 50% using VEGF-loaded scaffolds after 2 weeks of culture. Significance The 3D printed gelatin/alginate/β-TCP scaffold with slow releasing of VEGF can be considered as a potential candidate for regeneration of craniofacial defects
Investigation of primary microcephaly in Bushehr province of Iran: novel STIL and ASPM mutations
Genetics of intellectual disability in consanguineous families
Autosomal recessive (AR) gene defects are the leading genetic cause of intellectual disability (ID) in countries with frequent parental consanguinity, which account for about 1/7th of the world population. Yet, compared to autosomal dominant de novo mutations, which are the predominant cause of ID in Western countries, the identification of AR-ID genes has lagged behind. Here, we report on whole exome and whole genome sequencing in 404 consanguineous predominantly Iranian families with two or more affected offspring. In 219 of these, we found likely causative variants, involving 77 known and 77 novel AR-ID (candidate) genes, 21 X-linked genes, as well as 9 genes previously implicated in diseases other than ID. This study, the largest of its kind published to date, illustrates that high-throughput DNA sequencing in consanguineous families is a superior strategy for elucidating the thousands of hitherto unknown gene defects underlying AR-ID, and it sheds light on their prevalence
Source Evaluation and Trace Metal Contamination in Benthic Sediments from Equatorial Ecosystems Using Multivariate Statistical Techniques
race metals (Cd, Cr, Cu, Ni and Pb) concentrations in benthic sediments were analyzed through multi-step fractionation scheme to assess the levels and sources of contamination in estuarine, riverine and freshwater ecosystems in Niger Delta (Nigeria). The degree of contamination was assessed using the individual contamination factors (ICF) and global contamination factor (GCF). Multivariate statistical approaches including principal component analysis (PCA), cluster analysis and correlation test were employed to evaluate the interrelationships and associated sources of contamination. The spatial distribution of metal concentrations followed the pattern Pb>Cu>Cr>Cd>Ni. Ecological risk index by ICF showed significant potential mobility and bioavailability for Cu, Cu and Ni. The ICF contamination trend in the benthic sediments at all studied sites was Cu>Cr>Ni>Cd>Pb. The principal component and agglomerative clustering analyses indicate that trace metals contamination in the ecosystems was influenced by multiple pollution sources
Contamination assessment of arsenic and heavy metals in a typical abandoned estuary wetland—a case study of the Yellow River Delta Natural Reserve
The frequency of ovarian masses and lesions in different age categories in Khorram Abad (1381-1391)
Introduction: Ovarian cancer is the second most common cancer of the reproductive organs and the most common cause of death from malignancy of reproductive organs. Ovarian tumors are very different in terms of histology. The studies showed a large variation in prevalence and types of ovarian tumors at different ages. This study was performed with the aim to evaluate the frequency of the ovarian lesions at different age categories. Methods: this descriptive study was performed on 350 ovarian pathology samples of women referred to Pathology Center of Khorram Abad Shohadaye Ashayer during 2002-2012. Data related to physical examination and demographic data and chief complain of patients obtained from archival records and if necessary contact with them. The vague pathology specimens and insufficient records were excluded. Data was analyzed by SPSS statistical software (version 16). P< 0.05 was considered significant. Results: 83.4 of masses were related to reproductive ages that 91.4 of them were benign and the malignant tumors were predominantly observed in pre and post menopausal ages. Many masses were discovered and removed during other abdominal surgeries such as appendectomy that mostly were in reproductive ages andmost of them were benign. Conclusions: despite functional cysts are more common in reproductive ages, the highest prevalence of ovarian malignant lesions are seen in pre and post menopausal ages that Cerocyst adenocarsinoma is the most common. According to the increased prevalence of ovarian malignancies in these age categories, follow up of the masses in these age groups is very important. Therefore, it is recommended that this subject be given more importance in the annual examinations. © 2015-Journal Management System
Constitutive relationships for normal-and high-strength concrete at elevated temperatures
In this study, constitutive relationships are developed/or normal-strength concrete (NSC) and high-strength concrete (HSC) subjected to fire to provide efficient modeling and specify the fire-performance criteria for concrete structures exposed to fire. They are developed for unconfined NSC and HSC specimens that include compressive and tensile strengths, compressive elastic modulus, and compressive and tensile stress-strain relationships at elevated temperatures. The proposed relationships at elevated temperatures are compared with the experimental results and previous existing relationships revealing several advantages and disadvantages of present stress-strain relationships. These results are used to establish more accurate and general compressive and tensile stress-strain relationships. Further experimental results for tension and the other main parameters at elevated temperatures are needed to establish well-founded models and improve the proposed constitutive relationships, which are general and rational and fit well with the experimental results. Copyright © 2011, American Concrete Intitute. All rights reserved
High-temperature mechanical properties of concrete
Structural fire safety capacity of concrete is very complicated because concrete materials have considerable variations. In this paper, constitutive models and relationships for concrete subjected to fire are developed, which are intended to provide efficient modeling and to specific fire-performance criteria of the behavior of concrete structures exposed to fire. They are developed for unconfined concrete specimens that include residual compressive and tensile strengths, compressive elastic modulus, compressive and tensile stress-strain relationships at elevated temperatures. In this paper, the proposed relationships at elevated temperatures are compared with experimental result tests and pervious existing models. It affords to find several advantages and drawbacks of present stress-strain relationships and using these results to establish more accurate and general compressive and tensile stress-strain relationships. Additional experimental test results are needed in tension and the other main parameters at elevated temperatures to establish well-founded models and to improve the proposed relationships. The developed models and relationships are general, rational, and have good agreement with experimental data
The pathologic assessment of breast masses, before and after Menopause
Introduction: Menopause is a permanent and important event in women life that the time of its creation is influenced by several factors. In this period due to hormonal changes, women are prone to cardiovascular problems, breast mass and cancer and endometrial cancer. This study was performed to evaluate the pre-and post-menopausal pathologies samples of breast. Methods: In this study, 310 pathological samples of breast were studied in pathology center of Shohada hospital in Khorramabad, Iran during 2002 to 2012. The study samples were patients who had underwent mass and tumor biopsy, radical mastectomy and removal of lymph nodes, total and partial mastectomy and their pathologic data had been recorded. Physical examination, patient demographic data and their chief complain were extracted. Data were analyzed by SPSS software (version 16) and Chi-square test. P value less than 0.05 was considered significant. Results: The most common pathological findings in women older than 40 years were respectively fibro adenoma (28.7) and ductal carcinoma (27.3). Fibro adenoma (39.2) was the most common finding in premenopausal stage and ductal carcinoma (34.4) in postmenopausal stage. Conclusion: The most common type of masses in premenopausal period are benign and in postmenopausal are malignant. The regular periodic examination and mammographic follow up are recommended during menopausal age
FABRICATION AND CHARACTERIZATION OF ELECTROSPUN PLLA/COLLAGEN NANOFIBROUS SCAFFOLD COATED WITH CHITOSAN TO SUSTAIN RELEASE OF ALOE VERA GEL FOR SKIN TISSUE ENGINEERING
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