3D-printed nanohydroxyapatite/methylacrylylated silk fibroin scaffold for repairing rat skull defects.

The repair of bone defects remains a major challenge in the clinic, and treatment requires bone grafts or bone replacement materials. Existing biomaterials have many limitations and cannot meet the various needs of clinical applications. To treat bone defects, we constructed a nanohydroxyapatite (nHA)/methylacrylylated silk fibroin (MASF) composite biological scaffold using photocurable 3D printing technology. In this study, scanning electron microscopy (SEM) was used to detect the changes in the morphological structure of the composite scaffold with different contents of nanohydroxyapatite, and FTIR was used to detect the functional groups and chemical bonds in the composite scaffold to determine the specific components of the scaffold. In in vitro experiments, bone marrow mesenchymal stem cells from SD rats were cocultured with scaffolds soaking solution, and the cytotoxicity, cell proliferation, Western blot analysis, Quantitative real-time PCR analysis, bone alkaline phosphatase activity and alizarin red staining of scaffolds were detected to determine the biocompatibility of scaffolds and the effect of promoting proliferation and osteogenesis of bone marrow mesenchymal stem cells in vitro. In the in vivo experiment, the skull defect was constructed by adult SD rats, and the scaffold was implanted into the skull defect site. After 4 weeks and 8 weeks of culture, the specific osteogenic effect of the scaffold in the skull defect site was detected by animal micro-CT, hematoxylin and eosin (HE) staining and Masson's staining. Through the analysis of the morphological structure of the scaffold, we found that the frame supported good retention of the lamellar structure of silk fibroin, when mixed with nHA, the surface of the stent was rougher, the cell contact area increased, and cell adhesion and lamellar microstructure for cell migration and proliferation of the microenvironment provided a better space. FTIR results showed that the scaffold completely retained the ß -folded structure of silk fibroin, and the scaffold composite was present without obvious impurities. The staining results of live/dead cells showed that the constructed scaffolds had no significant cytotoxicity, and thw CCK-8 assay also showed that the constructed scaffolds had good biocompatibility. The results of osteogenic induction showed that the scaffold had good osteogenic induction ability. Moreover, the results also showed that the scaffold with a MASF: nHA ratio of 1: 0.5 (SFH) showed better osteogenic ability. The micro-CT and bone histometric results were consistent with the in vitro results after stent implantation, and there was more bone formation at the bone defect site in the SFH group.This research used photocurable 3D printing technology to successfully build an osteogenesis bracket. The results show that the constructed nHA/MASF biological composite material, has good biocompatibility and good osteogenesis function. At the same time, in the microenvironment, the material can also promote bone defect repair and can potentially be used as a bone defect filling material for bone regeneration applications.

The application of flipped classroom combined with team-based learning in the orthopedic clinical teaching.

BACKGROUND: Medical education has evolved rapidly, with the development of flipped classrooms and team-based learning based on lecture-based learning, but the novel model of combining flipped classrooms with team-based learning has been poorly investigated in orthopedic education. METHODS: A femoral neck fracture teaching mode was chosen to 109 clinical internship students to explore the effectiveness of flipped classroom combined with team-based learning in internship education. They were enrolled and randomly divided into either the flipped classroom combined with team-based learning group (FTG, n = 55) or the traditional lecture-based classroom group (n = 54). All students completed the learning according to the course flow and took before-class and after-class tests. The questionnaires were used to compare students perceptions and satisfaction with the different teaching methods and were utilized to assess the strengths and weaknesses of the 2 groups. RESULTS: The post-class test scores of both groups significantly improved compared to pre-class test scores. Regarding the post-class test scores, FTG's was significantly higher than the traditional lecture-based classroom group's, mainly in clinical areas such as imaging analysis, fracture classification, treatment options, and management of postoperative complications, but there was no significant difference in the mastery of basic theoretical knowledge. The students were more satisfied with the FTG and believed that it improved their various competencies, but with significantly more time spent. CONCLUSION: FTG is generally recognized as a promising option for training clinical interns and is worth spreading as it has outstanding merits in developing students clinical competence.

A comparison of different surgical approaches to hemiarthroplasty for the femoral neck fractures: A meta-analysis.

There are three traditional surgical approaches to hemiarthroplasty (HA) for femoral neck fractures, respectively, the anterior approach (AA), the lateral approach (LA) and the posterior approach (PA). However, the optimum approach is still controversial, the purpose of this meta-analysis is to identify the merits and demerits of all three approaches. All clinical published studies in PubMed, Web of Science, Embase, and the Cochrane Library from January 2000 to April 2022 were searched which compared different surgical approaches and covered surgery-related outcomes and frequent complications. Five randomized controlled trials and 26 cohort studies for a total of 31 clinical trials were included in the meta-analysis. The dislocation of PA was significantly higher than LA (OR: 3.00 95% CI: 2.25-4.01 I 2 = 27% P < 0.00001) and AA (OR: 6.61 95% CI: 2.28-19.13 I 2 = 0% P = 0.0005); PA was substantially more than LA in terms of risk of postoperative reoperation (P < 0.05); meanwhile, AA has markedly shorter hospital length of stays than LA. The remaining items showed no significant differences in the results.The results of this meta-analysis demonstrated that the risk of PA dislocation and reoperation is higher with hemiarthroplasty, and AA has markedly shorter hospital length of stays than LA.

Regulation of Intracellular Structural Tension by Talin in the Axon Growth and Regeneration.

Intracellular tension is the most important characteristic of neuron polarization as well as the growth and regeneration of axons, which can be generated by motor proteins and conducted along the cytoskeleton. To better understand this process, we created Förster resonance energy transfer (FRET)-based tension probes that can be incorporated into microfilaments to provide a real-time measurement of forces in neuron cytoskeletons. We found that our probe could be used to assess the structural tension of neuron polarity. Nerve growth factor (NGF) upregulated structural forces, whereas the glial-scar inhibitors chondroitin sulfate proteoglycan (CSPG) and aggrecan weakened such forces. Notably, the tension across axons was distributed uniformly and remarkably stronger than that in the cell body in NGF-stimulated neurons. The mechanosensors talin/vinculin could antagonize the effect of glial-scar inhibitors via structural forces. However, E-cadherin was closely associated with glial-scar inhibitor-induced downregulation of structural forces. Talin/vinculin was involved in the negative regulation of E-cadherin transcription through the nuclear factor-kappa B pathway. Collectively, this study clarified the mechanism underlying intracellular tension in the growth and regeneration of axons which, conversely, can be regulated by talin and E-cadherin.

Application of risk management in skin care of hospitalized neurosurgery patients / 中国实用护理杂志

Objective To investigate the application value of risk management in skin care of hospitalized neurosurgery patients. Methods 179 cases of hospitalized neurosurgical patients from January to December 2011 were chosen as research object.All the patients were divided into the observation group (91 cases,the risk management care group)and the control group (88 cases,the routine care group).The two groups accepted different nursing measures.The skin damage caused by medical factors,family factors and environmental factors for the two groups were taken for statistics and comparison. Results The patients with skin damage due to medical factors,family factors and environmental factors in the observation group were significantly lower than the control group,there was significant difference. Conclusions The application of risk management methods in skin nursing of hospitalized neurosurgery patients has good effect.It can reduce the rate of skin damage of patients significantly and is recommended widely used in hospitalized neurosurgery patients.

Exploration and development of summer research practice on the quality training of seven-year-program medical students / 中华医学教育探索杂志

By participating in the research practice of basic medicine,the innovative consciousness,the scientific thinking and researching ability of seven-year program medical students can be improved. Meanwhile,the generalization of Open Experimental Teaching and further development of self-design experiment also improve the innovation and research ability of medical students,which can serve as a new approach to the quality education of higher medical talents.

Reform and development on cytobiology experiment teaching for seven-year-program medical students / 中华医学教育探索杂志

Seven-year-program medical education is an important model to train high-level medical person.Through the change of the teaching concept in medicine cytobiology experiment,re-form of the teaching content,and the use of a variety of effective teaching methods,students’com-prehensive quality,innovative thinking and practical ability is improved,which can meet the needs of modern medical education.