BACKGROUND:Soft tissue engineering mainly includes seed cells,scaffolds,cytokines and bioreactors,among which,the scaffolds are the key link in the construction of tissue-engineered cartilage.OBJECTIVE:To prepare an articular cartilage extracellular matrix/human umbilical cord Wharton gel porous scaffold,and to evaluate its physicochemical properties and biocompatibility.METHODS:The articular cartilage extracellular matrix/human umbilical cord Wharton gel porous scaffold was prepared by freeze thawing drying method using porcine articular cartilage extracellular matrix and human umbilical cord Wharton glue as raw materials.The porosity,water absorption,tissue composition and longitudinal compressive elastic modulus of the scaffold were measured and histologically stained.Rabbit chondrocytes were co-cultured with the articular cartilage extracellular matrix/human umbilical cord Wharton gel porous scaffold for 7 days.Then,scanning electron microscopy,live-dead cell staining and hematoxylin-eosin staining were performed.In addition,rabbit chondrocytes were cultured in the extract of the articular cartilage extracellular matrix/human umbilical cord Wharton gel porous scaffold and cell culture medium for 6 days,respectively;and MTT assay was used to detect cell proliferation.RESULTS AND CONCLUSION:The articular cartilage extracellular matrix/human umbilical cord Wharton gel porous scaffolds had a cross-section of uniform porous network structure and a vertical cross-section of the vertical tubular structure,and the pore wall was densely covered with cartilage fibers.The composite porous scaffold was positive for hematoxylin-eosin staining,safranin O staining and toluidine blue staining,and contained collagen and glycosaminoglycan ingredients.The water absorption,porosity and longitudinal compressive elastic modulus of the scaffolds were (17.418 8±0.909 0)％,(81.495 1±6.621 0)％ and (2.833 3±0.456 4) kPa,respectively.After 7 days of co-culture,rabbit chondrocytes adhered to the scaffold and proliferated,and further grew into the pores of the scaffold.Moreover,the scaffold was non-toxic to the rabbit chondrocytes.To conclude,the physiochemical properties and biochemical components of articular cartilage extracellular matrix/human umbilical cord Wharton gel porous scaffolds are similar to those of natural cartilage,and the scaffold has good biocompatibility.

Central South University began to implement the eight-year medical education in 2004, and has accumulated rich experience in the pre-medical education through continuous reform and improvement. Since 2012, Central South University has made a series of reformation, which is more conducive to the all-round development of medical students , on the pre-medical education . Through adding freshman courses, humanities courses, bilingual teaching courses, and applying aca-demic adviser institution, early scientific research training and open courses during the pre-medical education, Central South University has exercised and strengthened students' scientific research ability, the humanistic quality, English level, and made the pre-medical comprehensive examination for the shunt selection of students. Thus Central South University has improved the eight-year medical students' comprehensive quality, and provided an example of the reformation for medical education.

OBJECTIVE:To screen the method for extracting total flavonoids in persimmon leaves and optimize extraction tech-nology. METHODS:Using extract quality and flavonoids content as indexes,the effects of extracting total flavonoids in persim-mon leaves by ethanol refluxing method,enzyme method(cellulase,β-glucanase and complex enzyme mixed by equal amounts of both),semi-bionic method and semi-bionic-enzyme method (the same enzymes) were compared. Using flavonoids content as in-dex,solid-liquid radio,reflux temperature,reflux time as factors,orthogonal test was designed to optimize the extraction technolo-gy conditions of flavonoids in persimmon leaves by semi-bionic-enzyme method,and the verification test was conducted. RE-SULTS:The extract quantity and flavonoids content by semi-bionic-enzyme method was the highest among the 4 extraction meth-ods,and the complex enzyme was the most suitable;the optimized extracting condition of semi-bionic-enzyme method were as fol-lows as solid-liquid radio of 1:14,reflux temperature of 50 ℃,reflux time of 2.0 h;extraction rates of flavonoids in 3 verification tests were 5.9%,5.8%,5.9%(RSD=0.98%,n=3). CONCLUSIONS:The optimized semi-bionic-enzyme method is efficient and stable in extracting flavonoids in persimmon leaves.

Objective To study the influence of swimming training for different periods on rat liver function, and to evaluate the quality of exercise-induced fatigue rat model established by swimming training for different periods. Methods Forty SD rats were randomly divided into 5 groups, namely blank group, and 7-, 14-, 21-and 28-day exercise groups, 8 rats in each group. Rats in the blank group were fed with normal diet, but were not given exercise training. The other groups were given exercise training for 7, 14, 21 and 28 days respectively, two times a day, 15 minutes every time and with 10-minute resting interval between the two times. At the last day of the experiment, all rats were executed by neck dislocation for the sampling of blood and liver tissues, and then the serum contents of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were determined. And the contents of total anti-oxidization capacity (T-AOC), malondialdehyde (MDA), lactic acid (LA), lactate dehydrogenase (LDH) and glucose (Glu) in liver tissues were also examined. Results Compared with the blank group, the contents of ALT and AST were increased in 7-, 14-, 21-, and 28-day exercise groups, especially in 21-and 28-day exercise groups (P<0.01) . The contents of T-AOC and MDA were increased in 7-, 14-, 21-, and 28-day exercise groups (P<0.01), the effects on T-AOC in the 21-and 28-day exercise groups and on MDA in the 28-day exercise group being more obvious (P<0.05 or P<0.01) . The LA content and LDH activity were increased and the glycogen was decreased in the liver tissues of 7-, 14-, 21-, and 28-day exercise groups, and the increase of LA content in 21- and 28-day exercise groups and that of LDH activity in 28-day exercise groups were more significant ( P<0.05 or P<0.01). The hepatic glycogen content in 14-, 21-, and 28-day exercise groups were lower than that in the other groups (P<0.01). Conclusion With hepatic function injury in exercise-induced fatigue as the criteria, the exercise-induced fatigue rat model has been successfully established in this study, and the model established by swimming training for 21 and 28 days is more steady.

Recently,as the exposure of the incident of‘octuplet’in Guangdong province,China's underground surrogate market has once again surfaced and led to a wide range of discussion.In this paper,the connotation and characteristics of surrogacy were analyzed and related laws and regulations of surrogacy in foreign countries were discussed.The main types of surrogacy-related legislation and regulations abroad are autonomy of private law,governmental regulation and complete prohibition.This paper carried out thorough legal analysis on whether to prohibit strictly or establish an authoritative legal system in view of the existing and ineffectively prohibited underground surrogate market in our country.

Chitosan-carboxymethyl-chitosan complex film was prepared by freeze drying. Some tests in vivo and in animal were employed, in order to evaluate it on biology. All results indicated that the film has not only good surface compatibility but also good structural compatibility. It can be more suitable for GTR technology.
Animals ; Biocompatible Materials ; chemical synthesis ; pharmacology ; Chitin ; analogs & derivatives ; Chitosan ; Materials Testing ; Membranes, Artificial ; Rabbits ; Rats ; Skin Irritancy Tests

Objective To analyze the imaging features of Menkes disease in children, and in order to identify the diagnostic value and improve the knowledge of it. Methods The imaging findings of 9 Menkes disease patients confirmed by the clinical and laboratory examinations were retrospectively analyzed. All the patients were male aged from 2.0 to 7.0 months with a median age of 3.0 months. The clinical manifestations including seizures, psychomotor retardation, dystonia accompanied with light complexion and curly hair. The laboratory examinations showed low serum copper and ceruloplasmin levels. All the patients were performed with plain MR scan and MR angiography, 7 cases were performed with chest X?ray examinations and 4 cases were performed with bone X?ray examinations and 1 were performed with hand X?ray examinations. Results The plain MR scan showed white matter lesions in 8 cases, abnormality signal intensity of basal ganglia in 4 cases, subdural effusion in 2 cases. 8 cases had cerebral and cerebellar atrophy at different degrees. The MR angiography showed abnormal tortuosity of the main intracranial arteries. The chest X?ray of 5 in 7 cases showed that the front end of bilateral ribs were spherical and enlarged. 4 cases were performed with bone X?ray presenting, 3 out of 4 cases showed the widened metaphysis of tibia, fibula, femoral, humerus ulna and radius with the shape like cup?mouth and the formation of bony spur locally. The X ray examination of 1 case with connecting palm showed symphysodactylia. Conclusion Brain MR, X?ray of chest and bone showed imaging features of Menkes disease. MR angiography finding was the most distinctive feature, which has important value in the diagnosis of Menkes disease.

Objective:To investigate the expression of cytokine cyclin 6 (CDC6) in pancreatic ductal adenocarcinoma, and its correlation with prognosis.Methods:The expression levels of CDC6 mRNA in pancreatic cancer tissues and normal tissues adjacent to the cancer were analyzed using the gene expression interaction analysis (GEPIA) database, and the correlation between CDC6 and the clinical prognosis of pancreatic cancer was analyzed using Kaplan-Meier. The clinicopathological characteristics of 80 patients with pancreatic ductal adenocarcinoma were retrospectively analyzed. The expression of CDC6 in pancreatic cancer tissues and normal tissues adjacent to the cancer was detected by immunohistochemical staining, and the data were analyzed by Graphpad 8.0 software to explore the clinical significance of high CDC6 protein expression.Results:Immunohistochemical staining results showed that the expression of CDC6 in pancreatic cancer tissues was much higher than that in normal tissues ( P<0.05), and the correlation between CDC6 and age, gender, and tumor grade of pancreatic cancer patients was not statistically significant (all P>0.05), but closely correlated with the size of the tumor ( P<0.05). Conclusions:CDC6 is closely related to the clinical prognosis of pancreatic cancer and is highly expressed in the developmental evolution of pancreatic cancer. Therefore, CDC6 is expected to be a target and potential biomarker for pancreatic cancer therapy.

With the construction and development of head and neck tumor, diagnosis and treatment technology and survival rate of patients have been improved in different degrees. Nurses play an important role as managers and practitioners in the treatment and rehabilitation of patients with head and neck tumors, and it is very important to evaluate and manage the treatment and prognosis of head and neck tumor patients scientifically. In this context, the American Cancer Society launched the Head and Neck Cancer Survivorship Care Guideline in 2017 and was endorsed by the American Society for Clinical Oncology. This paper mainly discusses the forming process of the guidelines, the main points of the consensus of experts, the guiding role of the guidelines in clinical work and the obstacles and limitations of the guidelines.

Pulmonary infection is a common and frequent disease in children, which is caused by viruses, atypical pathogens, and mostly bacteria, seriously threatening children′s health.Bacteria are divided into Gram-positive bacteria and Gram-negative bacteria.The former mainly includes Streptococcus pneumoniae, Staphylococcus aureus, Streptococcus pyogenes, etc.In this article, pediatric chest imaging techniques and 4 typical imaging features of Gram-positive cocci pneumonia in children were summarized aiming providing imaging information for clinical diagnosis, assessment of efficacy and prognosis of Gram-positive cocci pneumonia.