Objective To evaluate the security and biocompatibility of a new kind of absorbable high-strength PDLLA-CPP composite, which is used for internal fracture fixation. Methods According to the national standard of the procedure of appraise in food security and toxicology, micronucleus test of bone marrow cell, spermatic aberration test, chromosomal aberration test, and teratogenic test were measured with IP maximal tolerance dose of maceration extract from PDLLA-CPP composites. Meanwhile, chondrocyte culture with PDLLA-CPP composite was used to evaluate the effect of PDLLA-CPP composite on cartilage cell proliferation. Results Micronucleus test of bone marrow cell, spermatic aberration test, chromosomal aberration test, and teratogenic test were not affected by IP maximal tolerance dose of PDLLA-CPP maceration extract. PDLLA-CPP composite also had no cytotoxicity on cartilage cell proliferation. Conclusion PDLLA-CPP is a new and safe medical material with good biocompatibility and absorbability.

BACKGROUND: Uncontrolled-rate freezing in -80 ℃ refrigerator is convenient, while controlled-rate freezing in -196 ℃ liquid nitrogen is reliable and long-term, the combination of the two can simplify the process and has been successfully used in clinics. OBJECTIVE: To explore the influences of different cryoprotectants by ladder-style freezing from -80 ℃ low temperature refrigerator to liquid nitrogen on the cryopreservation of hemopoietic stem cells. METHODS: The experiments were divided into four groups: 10% dimethyl sulfoxide (DMSO) group, 5% DMSO combined with 3% hydroxyethyl starch group, 5% DMSO combined with 0.25 mol/L trehalose group, 5% DMSO combined with 3% hydroxyethyl starch and 0.25 mol/L trehalose group. Peripheral hemopoietic stem cells were cryopreserved by ladder-style freezing from -80 ℃ low temperature refrigerator to liquid nitrogen. The ultrastructural changes were examined by transmission electron microscopy, the expressions of Annexin-V, PI and Caspase-3 were detected by flow cytometry. RESULTS AND CONCLUSION: There was no significant difference in survival rate, apoptotic rate and necrotic rates of the cryopreserved cells in the four groups (P > 0.05). The ultrastructural changes had no significant difference under the transmission electron microscopy. The viability was more than 90% in frozen-thawed mononuclear cell colonies, and the apoptosis was roughly 50% in the frozen-thawed CD45+ cell population, which contained many mature cells. Of hemopoietic stem cells, early stage cells have greater resistance to damage of cryopreservation than late stage cells. It is concluded that the addition of hydroxyethyl starch or trehalose into DMSO exhibits no synergistic protective effect on the cryopreservation of hemopoietic stem cells.

Objective To describe the general condition of workplace violence against emergency department nurses in five hospitals of Guangzhou;to investigate the status of the post-traumatic stress disorder in the emergency department nurses after suffering from workplace violence;to analyze the relative factors of post-traumatic stress disorder.Methods 143 emergency department nurses from 5 hospitals in Guangzhou were investigated by general information questionnaire,workplace violence questionnaire,PCLC and SSRS.The investigation data were analyzed.Results 86.7％ of emergency department nurses suffered from workplace violence during the past 1 year;the most popular style was non-physical violence.The emergency department nurses suffered from negative emotional experience,such as grievance,chagrin,low work passion,not focused spirit.The scores of PCL-C of emergency department nurses who had suffered from workplace violence were obviously higher than those who hadn't.21.8％ of the emergency department nurses who suffered from workplace violence in the past one year had certain degree of the signs of PTSD,12.1％ had obvious signs of PTSD.The influencing factors of PTSD:degree of hurt,objective support and availability of social support.Conclusions The situation of workplace violence which the emergency department nurses were faced with was more and more grave.The emergency department nurses who had suffered from workplace violence were in different degree of PTSD.The more social supports the nurses get,the better mental health status they will possess.

How to give full play to the advantages of rehabilitation institutions, and to improve service quality and administration efficiency are some of the complex issues faced by the high-level administrators of rehabilitation institutions. This paper studied a total of 67 institutions to investigate the operation and management model of rehabilitation institutions in China, as well as their advantages and disadvantages.

The establishment of an efficient performance management system is crucial for a rehabilitation institution. This article discussed the concept of performance, performance management and ways to establish an efficient performance management system.

Objective:To analyze the risk factors for lymph node metastasis in breast cancer patients with axillary lymph node metastasis after neoadjuvant chemotherapy.Methods:The data of 94 female patients with invasive breast cancer in Dongguan People′s Hospital of Guangdong Province from January 2017 to December 2019 were retrospectively analyzed.All patients planned to receive 4-8 cycles of neoadjuvant chemotherapy.After chemotherapy, modified radical mastectomy was performed.Estrogen receptor(ER), progesterone receptor(PR) and human epidermal growth factor receptor 2(HER-2) appeared for the first time in Chinese and English abstracts and texts positive patients received endocrine or targeted therapy.The rest patients received 2-4 cycles of adjuvant chemotherapy or radiotherapy according to the situation.Lymph node metastasis after neoadjuvant chemotherapy was analyzed.The relationship between lymph node metastasis after neoadjuvant chemotherapy and clinicopathological features was analyzed.Risk factors for lymph node metastasis after neoadjuvant chemotherapy were analyzed by Logistic regression.Results:After neoadjuvant chemotherapy, the positive rate of axillary lymph node was 74.47%(70/94). The number of positive axillary lymph nodes, ER status, HER-2 status and cell proliferation-associated human nuclear antigen(Ki67), the completion of chemotherapy cycle, the pathological remission of axillary lymph nodes after chemotherapy and the T stage of tumor after neoadjuvant chemotherapy were associated with lymph node metastasis in patients with positive axillary lymph nodes after neoadjuvant chemotherapy(χ 2=30.053, 10.233, 6.303, 7.666, 18.162, 10.148, 12.418; all P<0.05). More than 3 positive axillary lymph nodes( OR=2.788, 95% CI 1.253-5.318), ER positive( OR=3.298, 95% CI 1.744-7.837), Ki67 positive( OR=2.469, 95% CI 1.184-4.301)and pathological pPR( OR=4.197, 95% CI 2.168-13.788) were independent risk factors for lymph node metastasis after neoadjuvant chemotherapy(all P<0.05). Conclusion:Axillary lymph node-positive breast cancer patients have a high positive rate of axillary lymph nodes after neoadjuvant chemotherapy.More than 3 positive axillary lymph nodes before operation, ER positive, Ki67 positive, and axillary lymph node pPR after neoadjuvant chemotherapy are independent risk factors for lymph node metastasis after neoadjuvant chemotherapy.

Objective:To evaluate the therapeutic effect of glycyrrhetinic acid on cough variant asthma (CVA) mice based on molecular docking technique; To explore the possibility of its treatment for cough variant asthma.Methods:The software of Autodock Vina was used for molecular docking. The mice were divided into control group, model group, prednisone acetate group, glycyrrhetinic acid high-, medium-, and low-dosage groups according to the random number table method, with 8 mice in each group. Except for the blank control group, all other groups were induced by egg protein to establish cough variant asthma models. Glycyrrhetinic acid high-, medium-, and low-dosage groups were orally administered glycyrrhetinic acid suspension at 20, 10, and 5 mg/kg, while the prednisone acetate group was orally administered prednisone acetate at 5 mg/kg. The blank control group and model group were orally administered equal volumes of physiological saline, once per day for 14 consecutive days. The animal asthma behavior was observed after drug administration. The secretion of bronchial mucus in lung tissue were observed by AB-PAS staining and the index of spleen were recorded. The protein expressions of Gata3, IL-4 and IL-13 in the spleen tissue were determined by Western blot.Results:Molecular docking results showed that glycyrrhetinic acid had good binding ability to Th2-related factors Gata3, IL-4 and IL-13. Results of animal experiment showed that compared with the model group, the mucus secretion decreased in glycyrrhetinic acid groups, the index of the spleen of mice obviously decreased, protein expression levels of IL-4 and IL-13 in the spleen tissue of mice in glycyrrhetinic acid high-, medium-, and low-dosage groups decreased ( P<0.05), and Gata3 in glycyrrhetinic acid medium- and low-dosage groups decreased ( P<0.05). Conclusion:Glycyrrhetinic acid can correct the shift of Th2 in the immune system of cough variant asthma mice and has a certain therapeutic effect.

Objective:To explore the balance performance of young adults under the interference of different cognitive tasks,and the moderating effect of long-term physical exercise. Method:The static and dynamic balance of healthy young people with physical exercise habit and without physical exercise habit were tested under the interference of different cognitive tasks.One-way repeated mea-sures ANOVA was performed with the group variable(Group)as the between-subjects factor and the results of multiple balance tests(Task)as the within-subjects variable. Result:Long term physical exercise had a positive moderating effect on the static balance during calculation,singing,and writing interference,the static mediolateral symmetrical balance during writing interference,the static anteroposterior symmetrical balance during singing interference,and the dynamic balance during comput-ing interference(P＜0.05).The dual-task cost of young people was significantly reduced when they are dis-turbed by the corresponding cognitive tasks(P＜0.05).However,it had a negative regulatory effect on the stat-ic mediolateral balance of calculation interference,the static anteroposterior balance of reading interference,and the dynamic mediolateral balance of calculation and singing interference(P＜0.05). Conclusion:Long term physical exercise has a significant moderating effect on young people's dynamic and static balance performance when different cognitive tasks are disturbed.