BACKGROUND: Nowadays, biological tissue engineering is a growing field of research. Biocompatibility is a key indicator for measuring tissue engineering biomaterials, which is of great significance for the replacement and repair of damaged tissues. METHODS: In this study, using gelatin, carboxymethyl chitosan, and sodium alginate, a tissue engineering material scaffold that can carry cells was successfully prepared. The material was characterized by Fourier transforms infrared spectroscopy. In addition, the prepared scaffolds have physicochemical properties, such as swelling ratio, biodegradability.we observed the biocompatibility of the hydrogel to different adult stem cells (BMSCs and ADSCs) in vivo and in vitro. Adult stem cells were planted on gelatin-carboxymethyl chitosan-sodium alginate (Gel/SA/CMCS) hydrogels for 7 days in vitro, and the survival of stem cells in vitro was observed by live/died staining. Gel/SA/CMCS hydrogels loaded with stem cells were subcutaneously transplanted into nude mice for 14 days of in vivo culture observation. The survival of adult stem cells was observed by staining for stem cell surface markers (CD29, CD90) and Ki67. RESULTS: The scaffolds had a microporous structure with an appropriate pore size (about 80 lm). Live/died staining showed that adult stem cells could stably survive in Gel/SA/CMCS hydrogels for at least 7 days. After 14 days of culture in nude mice, Ki67 staining showed that the stem cells supported by Gel/SA/CMCS hydrogel still had high proliferation activity. CONCLUSION Gel/SA/CMCSs hydrogel has a stable interpenetrating porous structure, suitable swelling performance and degradation rate, can promote and support the survival of adult stem cells in vivo and in vitro, and has good biocompatibility. Therefore, Gel/SA/CMCS hydrogel is a strong candidate for biological tissue engineering materials.

Teaching clinics represent a unique form of outpatient training of resident physicians and serve as a crucial instrument and core component of standardized training of general practice residents. This article reviews the common model and innovations of teaching clinics of general practice in China, and analyzes their reported effectiveness in enhancing the capabilities of consultation of resident physicians, the teaching capabilities of general practice trainers, as well as satisfaction levels of involved participants. It outlines the challenges encountered in implementing teaching clinics, including inadequate teaching facilities and equipment, incomplete incentive system for teaching, difficulties in patient recruitment, and weaknesses in the teaching capabilities of trainers. To address these challenges, this article proposes corresponding strategies based on realistic needs, including the improvement of facilities and equipment in teaching clinics, the establishment of incentive systems for teaching clinics, the expansion of patient recruitment channels for teaching clinics, and the enhancement of training for trainers' teaching capabilities. This is envisaged to provide both theoretical bases and practical guidance for the effective execution and standardized development of teaching clinics in general practice residency training bases.

Neurofibromatosis type 1(NF-1) with gastrointestinal stromal tumor (GIST) is a rare case in clinical practice. But it is even rarer that the GIST tumor in this case is so large that it cause small intestinal obstruction. Here we report such a male case of NF-1,with positive family history of NF-1 and nodules all over the patient's skin and abdominal cavity. The patient came to hospital with a sudden upper abdominal pain and nausea and vomiting over 5 d. Abdominal computerized tomography (CT) showed that there were numerous nodules of different size in his abdominal cavity. And the largest one is about 10 cm in diameter,which oppressed the small bowel and caused the small bowel mesenteric volvulus and obstruction of the bowel. Finally,the tumor was pathologically proved to be a GIST tumor but not NF nodule. The patient stays healthy until now after operation.