Three-dimensional bio-printing and bone tissue engineering: technical innovations and potential applications in maxillofacial reconstructive surgery

Background Bone grafting has been considered the gold standard for hard tissue reconstructive surgery and is widely used for large mandibular defect reconstruction. However, the midface encompasses delicate structures that are surrounded by a complex bone architecture, which makes bone grafting using traditional methods very challenging. Three-dimensional (3D) bioprinting is a developing technology that is derived from the evolution of additive manufacturing. It enables precise development of a scaffold from different available biomaterials that mimic the shape, size, and dimension of a defect without relying only on the surgeon’s skills and capabilities, and subsequently, may enhance surgical outcomes and, in turn, patient satisfaction and quality of life. Review This review summarizes different biomaterial classes that can be used in 3D bioprinters as bioinks to fabricate bone scaffolds, including polymers, bioceramics, and composites. It also describes the advantages and limitations of the three currently used 3D bioprinting technologies: inkjet bioprinting, micro-extrusion, and laser-assisted bioprinting. Conclusions Although 3D bioprinting technology is still in its infancy and requires further development and optimization both in biomaterials and techniques, it offers great promise and potential for facial reconstruction with improved outcome

Multiscale multifactorial approaches for engineering tendon substitutes

The physiology of tendons and the continuous strains experienced daily make tendons very prone to injury. Excessive and prolonged loading forces and aging also contribute to the onset and progression of tendon injuries, and conventional treatments have limited efficacy in restoring tendon biomechanics. Tissue engineering and regenerative medicine (TERM) approaches hold the promise to provide therapeutic solutions for injured or damaged tendons despite the challenging cues of tendon niche and the lack of tendon-specific factors to guide cellular responses and tackle regeneration. The roots of engineering tendon substitutes lay in multifactorial approaches from adequate stem cells sources and environmental stimuli to the construction of multiscale 3D scaffolding systems. To achieve such advanced tendon substitutes, incremental strategies have been pursued to more closely recreate the native tendon requirements providing structural as well as physical and chemical cues combined with biochemical and mechanical stimuli to instruct cell behavior in 3D architectures, pursuing mechanically competent constructs with adequate maturation before implantation.Authors acknowledge the project “Accelerating tissue engineering and personalized medicine discoveries by the integration of key enabling nanotechnologies, marinederived biomaterials and stem cells,” supported by Norte Portugal Regional Operational Programme (NORTE 2020), under the Portugal 2020 Partnership Agreement, through the European Regional Development Fund (ERDF). Authors acknowledge the H2020 Achilles Twinning Project No. 810850, and also the European Research Council CoG MagTendon No. 772817, and the FCT Project MagTT PTDC/CTM-CTM/ 29930/2017 (POCI-01-0145-FEDER-29930

Evaluation of clinical education in pediatric wards of hospitals affiliated to shahid beheshti university of medical sciences according to the ministry of health standards in 2015

Background and Aim: Clinical education is one of the most important parts of education in medicine and its aim is to providing the expert and efficient workforce to meet the needs of societies. The aim of current study was to evaluate clinical education in pediatrics wards of hospitals affiliated to the Shahid Beheshti University of Medical Sciences according to the Ministry of Health standards in 2015. Methods: The current survey is a cross-sectional study which was conducted during 2015. Faculty members, assistants and interns were selected from each pediatrics wards of Imam Hossein, Shohada Tajrish, Loqman and Mofid hospitals as the study population. The assessment tool is a self-made questionnaire. Data were analyzed with SPSS-16. Results: In the present study, 95 people from the Loqman (n=16), Imam Hossein (n=12), Shohada (n=15) and Mofid (n=52) Hospitals were participated. Among the participated people, 27 (28.4 ) were interns, 50 were (52.6 ) assistants and 18 (18.9 ) were professors. The findings of this study showed that none of the standards of clinical training did not apply according to the Ministry of Health standards from the perspective of faculty members, residents and interns. In all cases, faculty members in comparison to residents and interns, reported a higher rating to outpatient clinics, teaching round, grand round, morning reports, journal reports, and center of clinical skills, respectively. In all the hospitals, the center of clinical skills and journal clubs received the lowest scores. Conclusion: It can be concluded from the results of this study that from the perspective of residents, faculty members and interns none of the clinical training standards defined by the Ministry of Health, were fully respected. This is while morning reports were favorable and acceptable. However, some standards such as those related to clinical skill centers and journal clubs are facing weaknesses and as regards to their importance, considerations are required for their promotion and improvement

Commonality-Driven Unit Test Generation

Various search-based test generation techniques have been proposed to automate the generation of unit tests fulfilling different criteria (e.g., line coverage, branch coverage, mutation score, etc.). Despite several advances made over the years, search-based unit test generation still suffers from a lack of guidance due to the limited amount of information available in the source code that, for instance, hampers the generation of complex objects. Previous studies introduced many strategies to address this issue, e.g., dynamic symbolic execution or seeding, but do not take the internal execution of the methods into account. In this paper, we introduce a novel secondary objective called commonality score, measuring how close the execution path of a test case is from reproducing a common or uncommon execution pattern observed during the operation of the software. To assess the commonality score, we implemented it in EvoSuite and evaluated its application on 150 classes from JabRef, an open-source software for managing bibliography references. Our results are mixed. Our approach leads to test cases that indeed follow common or uncommon execution patterns. However, if the commonality score can have a positive impact on the structural coverage and mutation score of the generated test suites, it can also be detrimental in some cases.Software Engineerin