BACKGROUND:Polycaprolactone as a polymer material has poor biocompatibility, and needs to be combined with other natural biological materials to increase biocompatibility, thereby promoting tissue regeneration.OBJECTIVE:To develop a novel honeycomb-like polycaprolactone-calcium silicate crystal compound scaffold, and observe its osteogenic effects in Sprague-Dawley rats with skull defects.METHODS: Eighteen Sprague-Dawley rats were used to make skull defect models and randomized into three groups: blank control group with no implantation, control group with implantation of normal polycaprolactone-calcium silicate crystal compound scaffold, and experimental group with implantation of the novel honeycomb-like polycaprolactone- calcium silicate crystal compound scaffold. Six weeks after implantation, bone regeneration effect in the defect region measuredvia X-ray scanning, Micro-CT three-dimensional reconstruction, and histological analysis.RESULTS AND CONCLUSION: (1) X-ray scan: in all the rats, the size of bone defect was reduced, the fracture line became vague, and the marginal bone density was increased. The percentage of new bone area was highest in the experimental group, successively followed by the control group and blank control group. (2) Micro-CT three-dimensional reconstruction: new bones in the blank control group were mainly distributed on the both sides of the defect, but those in the control and experimental groups distributed in the defect region. The bone regeneration capacity was ranked as follows: experimental group > control group > blank control group (P < 0.05). (3) Histological analysis: new bone ingrowth was visible in all the three groups to different extents. Compared with the other two groups, new bone formation and microvessel density were significantly higher in the experimental group (P < 0.05). To conclude, this novel honeycomb-like polycaprolactone-calcium silicate crystal compound scaffold can obviously promote bone formation in the skull defect region.

Objective: This study aims to investigate the positive practice environments evaluation of doctors in public hospital and provide suggestions for Chinese health care reform from the perspective of health service providers.Methods: Using self-designed questionnaire, a national cross-sectional survey was performed in 77 public hospitals across seven provinces/ metropolis, involving a total of 3564 doctors.Positive practice environment includes organizational management and doctor-patient two-dimension relationships.Results: The doctor''s mean score of positive practice environment evaluation was 18.02±4.86 (out of 40).Doctors had a higher evaluation (score) of organizational management than doctor-patient relationship.In the organizational management dimension, the personal advice got the lowest scores(2.24±1.04);and in doctor-patient relations, evasion of medical risk got the lowest scores(1.59±0.81).There was a difference in the positive practice scores of physicians in different regions, and the scores of doctors from the western China were the lowest (P<0.001.Doctors from western medicine hospitals had lower evaluation of positive practice environments than ones from Chinese Traditional Medicine hospitals(P=0.002.Conclusion: As per the analysis conducted in this investigation, the current medical practice environment of doctors in China is not a promising one.Doctor-patient relationship is worse than organizational management.Hospitals should adopt a participatory decision-making model in management and establish a broadband performance based compensation to motivate junior doctors.Besides, government should establish reasonable compensation incentive mechanism, with the aim of promoting doctor-patient trust.

Objective:To explore the effect of post-pyloric feeding by spiral nasoenteric tubes on the prognosis of critically ill patients with acute gastrointestinal injury (AGI) grade Ⅱ.Methods:A retrospective study was performed to analyze the clinical data of critically ill adult patients with AGI grade Ⅱ, who were enrolled in three randomized controlled trials conducted by Guangdong Provincial People's Hospital for post-pyloric tube placement between April 2012 and May 2019. Data including demographic characteristics, serological indicators of nutrition, the tube tip position confirmed by abdominal X-ray 24 h after tube insertion, and intensive care unit (ICU), 28-day and hospital mortality were collected. Patients were divided into the post-pyloric feeding group and gastric feeding group according to the tube tip position. Propensity score matching method was used to perform 1:1 matching, and the differences of each index between the two groups were compared after matching. Then the influencing factors of P<0.1 were included in multivariate logistic regression analysis to investigate the potential ICU mortality risk factors of critically ill patients with AGI gradeⅡ. Factors with 0.1 level of significance from the univariate analysis were considered in the multivariate analysis. Results:There were 90 patients in post-pyloric feeding group and 90 patients in the gastric feeding group. Demographics and clinical characteristics of study population were well balanced between the two groups after matching. ICU, 28-day and hospital mortality in the post-pyloric feeding group were significantly lower than those in the gastric feeding group (4.4% vs 15.6%, 14.4% vs 27.8%, 6.7% vs 17.8%, all P < 0.05). Multivariate logistic regression analysis indicated that post-pyloric feeding was an independent protective factor [odds ratio ( OR)=0.295, 95% confidence internal (95% CI): 0.091-0.959, P=0.042] and APACHEⅡ score was an independent risk factor ( OR=1.111, 95% CI: 1.025-1.203, P=0.010) for ICU mortality of critically ill patients with AGI gradeⅡ. Conclusions:Post-pyloric feeding for critically ill patients with AGI grade Ⅱ could decrease ICU mortality and is an independent protective factor against mortality.

Objective To investigate the positive practice environments ( PPE ) of nurses and influencing factors at public hospitals , for reference of building a better PPE .Methods A national cross-sectional survey was performed at 77 public hospitals across seven provinces/metropolises, involving 5374 nurses.PPE included organizational management (internal) and nurses-patient relationship (external). Results The scoring of positive practice environment was 18.51 ±4.69 (total score of 40).The scoring of organizational management and nurses-patient relationship was 9.87 ±3.11 and 8.64 ±2.51 respectively. The scoring of PPE of nurses of general hospital ( GH) was higher than that of traditional Chinese medicine hospital(TCMH) (18.68 ±4.68 versus 18.08 ±4.67, P<0.01).Multivariable analysis showed that , compared with nurses who had not very much pressure about performance assessment , the scores of those who had were declined (βGH =-1.15, 95％CI: -1.55 to -0.76;βTCMH =-1.29, 95％CI: -1.92 to-0.66 ) );compared with nurses who paid less efforts in communicating with their patients , the scoring of those with greater efforts was higher (βGH =2.43, 95％CI:2.00 to 2.86;βTCMH =2.84, 95％CI:2.19 to 3.49).Conclusions PPE of nurses is poor in general in China , and the externally stressful nurse-patient relationship deserves greater attention and efforts than inefficient organization management internally .To improve PPE of nurses , hospitals need to moderate nurses′performance assessment and the nurses need to pay more attention to patient communication .

Objective To explore the application value of iASSIST portable navigation in total knee arthroplasty.Methods Seventy-four patients with knee osteoarthritis from April 2016 to April 2017 were retrospectively recruited.Thirty-seven patients (37 knees) underwent TKA with iASSIST navigation,while 37 patients (37 knees) underwent conventional TKA.Five parameters were measured on the weight-bearing radiographs at six months after TKA,including mechanical axis (MA),mechanical lateral distal femoral angle (mLDFA),mechanical medial proximal tibial angle (mMPTA),sagittal femoral component angle (sFCA) and sagittal tibial component angle (sTCA).Duration of operation,blood loss volume,postoperative hospital day,Western Ontario and McMaster Universities (WOMAC) osteoarthritis index,Knee Society Score (KSS) clinical score and functional score at 6 weeks,12 weeks and 24 weeks after surgery were also recorded.Results The accuracy of MA (180.85°±0.88° versus 182.23°±1.09° in the conventional group,P＜0.05),mLDFA (90.52° ±0.78° versus 91.09° ±0.96° in the conventional group,P＜0.05),and mMPTA (90.34°± 1.25° versus 91.13°± 1.46° in the conventional group,P＜0.05) was improved significantly in navigation group.The WOMAC osteoarthritis index at 6 weeks postoperatively in the navigation group and in the conventional group were 58.54±1.45 and 56.54± 1.77 respectively.The KSS clinical score in the navigation group and in the conventional group were 53.14± 1.13 and 49.35± 1.11 respectively.The KSS functional score in two groups were 61.24± 1.30 and 59.81 ± 1.29 respectively (P＜0.05).The WOMAC osteoarthritis index at 12 weeks postoperatively in the navigation group and in the conventional group were 43.54± 1.19 and 41.92± 1.42 respectively.At 12 weeks,the KSS clinical score in two groups were 67.11 ± 1.51 and 62.08± 1.46 respectively.The KSS functional score in two groups were 68.14±1.11 and 66.38±1.26 respectively (P＜0.05).The blood loss volume in the navigation group and in the conventional group were 113.11±57.29 ml and 147.57±68.77 ml respectively (P＜0.05).There were no significant difference in the duration of operation,postoperative hospital day,WOMAC osteoarthritis index,knee clinical score and functional score at 24 weeks postoperatively between two groups (P＞0.05).Conclusion More accurate restoration in mechanical axis and optimal implantation can be achieved with the help of iASSIST navigation.This navigation system can also achieve better knee function in the early stage after TKA.

Objective:To establish an animal model of trans-sutural distraction osteogenesis in SD rats.Methods:A self-designed V-shaped distraction device(distractor)was fabricated with the traction force(N)of 0,1.3,2.2,3.0,4.3 and 5.0 corresponding to the distraction length(mm)of 5,4,3,2,1 and 0 respectively,meeting the trans-sutural distraction osteogenesis requirements in skull of 5-week-old SD rats.The distractor was plased into the sagittal suture of 12 SD rats.Continuous sampling was conducted 1,3,5 and 7 days respectively(n=3)after operation.The tissue changes in the trans-sutural distraction area were observed by HE and Masson's trichrome staining.Inflammation levels were determined using Arg-1 immunofluorescence staining.The early angiogenesis was clarified through co-staining with CD31 and EMCN.Results:A stable trans-sutural distraction osteogenesis model was estab-lished,5 mm distraction osteogenesis width was observed completely within 7 days of distraction.Significant new bone formation was observed at 7 days after operation.Arg-1 expression increased and was concentrated at the bone margins,overlapping with the areas of new bone formation.EMCN expression gradually decreased,and by day 7 CD31 was predominant,indicating the basic maturation of blood vessels.Conclusion:This study successfully constructed a stable and effective trans-sutural distraction osteogenesis animal model,and provides an experimental basis for the investigation of its early continuous histological changes.

OBJECTIVE: To optimize the method for embedding multiple undecalcified mouse tibias in plastic blocks, improve the efficiency and stability of plastic embedding and reduce the detachment rate of plastic slides. METHODS: Thirty undecalcified tibias from 15 B6 mice were used for plastic embedding after calcein labeling, fixation, dehydration and infiltration. The tibias were embedded in cylindrical plastic blocks with a diameter of 4 mm. For each bone, the 1/4 proximal tibia was cut off, and the remaining 3/4 was used for re-embedding. Five bones were embedded in a single block with each bone standing closely on the surface of a flat plate. The samples were randomized into control and experimental groups in all the processes of embedding, sectioning and staining. In the 3 groups with modified embedment, flowing CO was added into the embedding solution, embedding solution was applied to the section surface, and the slides were heated at 95 ℃ for 15 min. The polymerization time, slide detachment rate, bone formation and osteoblast parameters were analyzed. RESULTS: We prepared 6 plastic blocks, each containing 5 tibias, whose cross sections were on the same plane. The blocks were completely polymerized and suitable for sectioning. Flowing CO into the embedding solution reduced the polymerization time and increased the rate of complete polymerization. Application of the embedding solution on the section surface significantly reduced the detachment rate of the sections ( < 0.05) without affecting bone formation analysis ( > 0.05). Heating the slides significantly lowered the detachment rate of the sections ( < 0.05) without affecting osteoblast analysis ( > 0.05). CONCLUSIONS The optimized method allows effective embedding of multiple undecalcified mice tibias in the same block and can be an ideal method for histological analysis of undecalcified bones.
Animals ; Mice ; Plastics ; Staining and Labeling ; Tibia ; Tissue Embedding ; methods

Cardiomyopathy, Dilated/metabolism* ; Humans ; Microfilament Proteins/metabolism* ; Models, Cardiovascular ; Mutation ; Myocytes, Cardiac ; Pluripotent Stem Cells/metabolism* ; Transcription Factors/metabolism* ; Troponin T/metabolism*