BACKGROUND:As tissue engineering brings new hope to the worldwide problem of articular cartilage repair,the construction of light-curing 3D printed hydrogel scaffolds with biomimetic composition is of great significance for cartilage tissue engineering. OBJECTIVE:To construct a biomimetic methacryloylated hyaluronic acid/acellular Wharton's jelly composite hydrogel scaffold by digital light processing 3D printing technology,and to evaluate its biocompatibility. METHODS:Wharton's jelly was isolated and extracted from human umbilical cord,then decellulated,freeze-dried,ground into powder,and dissolved in PBS to prepare 50 g/L acellular Wharton's jelly solution.Methylallylated hyaluronic acid was prepared,lyophilized and dissolved in PBS to prepare 50 g/L methylallylated hyaluronic acid solution.Acellular Wharton's jelly solution was mixed with methacrylyacylated hyaluronic acid solution at a volume ratio of 1:1,and was used as bio-ink after adding photoinitiator.Methylacrylylated hyaluronic acid hydrogel scaffolds(labeled as HAMA hydrogel scaffolds)and methylacrylylated hyaluronic acid/acellular Wharton's jelly gel scaffolds(labeled as HAMA/WJ hydrogel scaffolds)were prepared by digital light processing 3D printing technology,and the microstructure,swelling performance,biocompatibility,and cartilage differentiation performance of the scaffolds were characterized. RESULTS AND CONCLUSION:(1)Under scanning electron microscope,the two groups of scaffolds showed a three-dimensional network structure,and the fiber connection of HAMA/WJ hydrogel scaffold was more uniform.Both groups achieved swelling equilibrium within 10 hours,and the equilibrium swelling ratio of HAMA/WJ hydrogel scaffold was lower than that of HAMA hydrogel scaffold(P＜0.05).(2)CCK-8 assay showed that HAMA/WJ hydrogel scaffold could promote the proliferation of bone marrow mesenchymal stem cells compared with HAMA hydrogel scaffold.Dead/live staining showed that bone marrow mesenchymal stem cells grew well on the two groups of scaffolds,and the cells on the HAMA/WJ hydrogel scaffolds were evenly distributed and more cells were found.Phalloidine staining showed better adhesion and spread of bone marrow mesenchymal stem cells in HAMA/WJ hydrogel scaffold than in HAMA.(3)Bone marrow mesenchymal stem cells were inoculated into the two groups for chondrogenic induction culture.The results of qRT-PCR showed that the mRNA expressions of agglutinoglycan,SOX9 and type Ⅱ collagen in the HAMA/WJ hydrogel scaffold group were higher than those in the HAMA hydrogel scaffold group(P＜0.05,P＜0.01).(4)These findings indicate that the digital light processing 3D bioprinting HAMA/WJ hydrogel scaffold can promote the proliferation,adhesion,and chondrogenic differentiation of bone marrow mesenchymal stem cells.

Objective:To study the factors influencing the happiness of dementia patients and their caregivers,provide guidance for improving their well-being.Methods:A total of 94 pairs of patients and their caregivers who were admitted to the neurology department of Peking Union Medical College Hospital from April 2015 to April 2016 were selected, the demographics of each patient and their caregivers were recorded. The Mini-Mental State Examination(MMSE) of patients with dementia, Role of Overload Scale(ROS) of caregivers, Dyadic Relationship Strain(DRS), Quality of Life for Dementia(QOL-D), Self-Evaluation Scale-Depression(CES-D) were recorded. Layered linear model was used to make regression analysis between the influencing factors and the scores of QOL-D and CES-D.Results:The results of the multi-layer linear model of uncontrolled variables in the fixed effect model: the results of QOL-D suggested that the score of patients with dementia was β 1j= 31.01±0.77, and the score of caregivers was β 2j= 35.15±0.88; the results of CES-D suggested that the scores of dementia patients and caregivers were β 1j = 14.55 ± 1.03 and β 2j = 13.11 ± 1.44, respectively. The random effects model suggested that there were statistical differences in the heterogeneity of the QOL-D score and the CES-D score variance component for dementia patients and caregivers (χ 2 values were 98.94-168.06, P<0.01). It indicated that the data was heterogeneous, adjusting the level 2 model, and the final results in the adjusted regression analysis suggested: caregiver relationship pressure (DRS), dementia patient self-awareness assessment (MMSE), caregiver care-related stress (ROS), dementia patient relationship stress (DRS) significantly affected the quality of life score (QOL-D) in both well-being ( β values were -3.22-0.43, P<0.05). Dementia patient relationship stress (DRS), caregiver-related stress (ROS), and caregiver relationship stress (DRS) significantly affected depressive symptoms in both well-being ( β values were 5.34, 3.26, 1.62, P<0.05). Conclusions:A comprehensive assessment of dementia patients and caregivers is needed. The combined family relationship is tense and the pressure associated with caregivers needs to be psychologically counseled.

Objective To investigate the effects and mechanisms of carbon monoxide-releasing molecule-2 (CORM-2) on LPS induced barrier injure of Caco-2 cells.Methods The model of Caco-2 monolayer cells damage induced by LPS was established by using 50 μg/ml LPS for 24 hours.After preconditioning with different concentrations (10 μmol/L,50 μmol/L,and 100 μ mol/L) of CORM-2 for 1 hour,the cultured well-grown Caco-2 monolayer cells were stimulated with 50 μ g/ml lipopolysaccharides (LPS) for 24 hour.The 100 μmol/L CORM-2 was put into 37℃ and 5％ CO2 incubator for 18 hours until the CO has been fully released,and it became an inactive CORM-2(iCORM-2).The cultured Caco-2 monolayer cells were divided into six groups:the control group,the LPS group,the LC1(10 μmol /L CORM-2 preconditioning) group,the LC2(50 μmol/L CORM-2 preconditioning) group,the LC3(100 μmol/L CORM-2 preconditioning) group,and the LC4 (iCORM-2 preconditioning) group.The apoptosis rates of different groups of Caco-2 monolayer cells were detected using flow cytometry.Cytokines (TNF-α,IL-1β and HMGB-1) levels of different groups were detected using ELISA kits.The levels of tight junction proteins (occludin ZO-1,claudin-1 and claudin-4) of every group were detected using Western blotting with specific antibodies.The structural changes of tight junction proteins were visualized by immunofluorescence technique.Results Compared with control group,cell apoptosis rate and release of inflammatory cytokines such as TNF-α,IL-1β and HMGB-1 in LPS group were significantly higher,and the levels of tight junction proteins were apparently decreased (P＜0.05) in LPS group.Compared with LPS group,cell apoptosis rate and release of inflammatory cytokines such as TNF-α,IL-1β and HMGB-1 decreased,and the levels of tight junction proteins were attenuated obviously,P＜0.05,in CORM-2 preconditioning groups.And the higher the concentration of CORM-2,the more obvious the protective effects.Conclusions This study demonstrates that CORM-2,as one of exogenous CO-releasing molecules,has the capacity to protect the barrier damage of LPS-stimulated Caco-2 monolayer cells in a concentration dependent manner.The higher the concentration of CORM-2 was,the stronger the protective effects were.The protective effects of CORM-2 include reducing Caco-2 monolayer cells apoptosis rate,inhibiting inflammatory cytokines production and release,and restoring distribution and levels of tight junction proteins.

Objective How to make good use of the construction opportunity of the medical association to integrate resources,build scientific research platform and establish practical operation mechanism,to improve the technology innovation ability of district county-level hospitals.Methods Through literature analysis and empirical study,this paper discusses the feasibility and operation mechanism of the construction of research platform in district county-level hospitals.Results The research platform can be built with the help of medical association construction.The operation mechanism can effectively improve the research level of district county-level hospitals,by taking the chance of discipline construction,implementing the institutional mechanism for rewards and punishment.Conclusions With the help of superior medical experts,two-way referral,academic lectures and other activities,advanced scientific culture idea was spread;The training of scientific research personnel,resource integration,and project cooperation increased opportunities.All of this to set up a new platform for district county-level hospitals to promote their scientific and technological innovation abilities.By taking the chance of discipline construction,clarified target responsibility,to carry out the rewards and punishment system and the implementation of the scientific and technological innovation incentive mechanism,can force them to actively promote the ability of scientific and technological innovation,actively carry out scientific research and improve the level of business.

Objective To observe the changes of telomere length and MMPs level in human fibroblasts induced by UVB, and to explore their roles on skin photoaging .Methods Human skin fibroblasts were extracted and cul-tured.The 5th fibroblasts were irradiated by UVB .The morphology of fibroblasts were microscoped , and the length of telomere and the mRNA expression of COL1a1 and hTERT were detected by RT-qPCR.The expression of MMP-3 and MMP-1 were detected by Western blot .Results The fibroblasts gradually became round , wrinkled and disorderly arranged after 30 mJ/cm2 UVB irradiation for 24 h.The mRNA level of COL1a1 and hTERT and the expression of MMP-3 and MMP-1 were significantly increased after UVB irradiation compared with control , and the length of telomere was shortened .Conclusions UVB may frigger the early process of photoaging by the morphologi-cal changes of human skin fibroblasts and increasing the expression of MMP-3 and MMP-1 .

Objective To investigate the effects of post-operative analgesia with oxycodone or morphine for patients undergoing colon cancer radical surgery on platelet activation and cellular immunity.Methods Forty colon cancer patients scheduled for radical surgery, 23 males and 17 females, ASA physical status Ⅰ or Ⅱ, were randomly divided into 2 groups (n=20 each): oxycodone group (group O) and morphine group (group M).Patient-controlled intravenous analgesia (PCIA) was used for post-operative analgesia.PCIA solution contained oxycodone 1 mg/kg and tropisetron 6 mg in 100 ml normal saline in group O or morphine 1 mg/kg and tropisetron 6 mg in 100 ml normal saline in group M.Blood samples were obtained from the patients at 5 min before anesthesia induction (T0), 4 h after surgery (T1), 24 h after surgery (T2) and 48 h after surgery (T3).The levels of glycoprotein (GP)Ⅱb/Ⅲa, P-selection (CD62P), natural killer (NK) cells, NKT cells, and natural Treg (nTreg) cells were detected.The platelet aggregation rate (PAR) was determined.Results Compared with T0, the levers of GPⅡb/Ⅲa, CD62P, PAR and nTreg cells were significantly higher at T1 in group O and at T1, T2 in group M (P<0.05).Compared with T0, the levels of NK and NKT cells were decreased significantly at T1 in group O and at T1-T3 in group M (P<0.05).The levels of GPⅡb/Ⅲa, CD62P, PAR and nTreg cells at T2 and T3 in group O were decreased significantly as compared with group M (P<0.05).The levels of NK cells, NKT cells at T2 and T3 in group O were significantly higher than those in group M.Conclusion Post-operative analgesia with oxycodone for patients undergoing colon cancer radical surgery exhibits a more significant effect of decreasing platelets activity and presents a less disturbance on cellular immunity as compared with morphine.

Objective To establish a mouse model of biliogenic severe acute pancreatitis (SAP) by using a self-made device for retrograde injection of sodium taurocholate into common bile duct,and to investigate the improvement of the device on retrograde injection of sodium taurocholate into common bile duct and its safety.Methods Thirty-six adult male ICR mice were randomly divided into biliogenic SAP model group and sham group,with 18 mice in each group.A 40 U disposable insulin syringe,a 200 μL tips and a 25 μL micro-syringer were used as basic materials for making the mouse common bile duct injection device [National Utility Model Patent (ZL 2014 2 0694365.4)].In model group,3.5％ sodium taurocholate (1 mL/kg) was injected retrogradely into the common bile duct of mice,whilst in sham group,the mice underwent the injection of equal amount of normal saline instead.Six mice in each group were sacrificed at 6,24 and 48 hours after operation,and the abdominal aortic blood was collected.Serum amylase (AMY),alanine aminotransferase (ALT),creatine kinase-MB (CK-MB),serum creatinine (SCr),oxygenation index (PaO2/FiO2) as well as serum Ca2+ were.determined.Pathological change in pancreas was observed under conventional light microscopy after hematoxylin and eosiu (HE) staining,and the impairment was evaluated by a widely used score system.Results The injection device was easily placed into mouse common bile duct under macroscopic observation.Six hours after operation,the levels of serum AMY,ALT and SCr in model group were significantly higher than those in sham group,and peaked at 24 hours,and they slightly decreased at 48 hours,which were still significantly higher than those of the sham group [24-hour AMY (U/L):7 325 ± 1 154 vs.1 737 ± 197,24-hour ALT (U/L):176.0±5.0 vs.38.3 ± 2.0,24-hour SCr (tmol/L):46.3 ± 1.5 vs.17.8 ±0.6,all P ＜ 0.01].The level of CK-MB at 6 hours in the model group was significantly higher than that of the sham group,and peaked at 48 hours (U/L:749.8±42.2 vs.383.3±35.5 at 6 hours,3 340.1 ± 203.6 vs.704.6 ± 63.5 at 48 hours,both P ＜ 0.01).PaO2/FiO2 at 6 hours after the operation in model group was significantly lower than that of sham group,then it began to rise at the similar level in sham group at 48 hours [mmHg (1 mmHg =0.133 kPa):327.5±33.8 vs.424.8±31.0 at 6 hours,P ＜ 0.01;429.8 ±41.8 vs.464.7±43.3 at 48 hours,P ＞ 0.05].Ca2+ level in model group was continuously decreased after operation,and it was significantly lower than that of sham group at 48 hours (mmol/L:1.58 ± 0.14 vs.2.45 ± 0.21,P ＜ 0.01).The pancreatic edema was obvious after operation in sham group,with the observation time prolongation,the changes were gradually improved;pancreatic focal necrosis was found at 6 hours after operation in model group,and it was secondary aggravated,and pancreatic lobule structure disappearance and inflammatory cells extensive infiltration was found at 48 hours.Pathological score of the model group was significantly higher than that of sham group at each time point,and peaked at 48 hours (13.3 ±0.3 vs.3.0±0.1,P ＜ 0.01).Conclusion It is a highly efficient and low-cost way to induce biliogenic SAP in mice by retrograde injection of 3.5％ sodium deoxycholate into common bile duct via the self-made injection device,and the model conformed to the clinical characteristics of biliogenic SAP.

Objective To investigate the effect of extracellular histones (EH) on intestinal mucosal barrier function in mice and the correlation of EH with the pathogenesis of sepsis.Methods Twenty male C57BL/6 mice were assigned into experiment group (n =10) and control group (n =10) according to the random number table.Same dose (50 mg/kg) of EH and saline were administered through the caudal vein of mice in experiment and control groups respectively.Blood and intestinal samples in each group were collected 3 h after the administration.Morphology of intestinal mucosal tissue was detected by light scope and transmission electron microscope.Expressions of tight junction related proteins (ZO-1,Occludin and Claudin-1) were detected by western blot.Plasma levels of diamine oxidase (DAO) and intestinal fatty acid binding protein (I-FABP) were determined by ELISA method.Plasma level of endotoxin (ET) was determined by limulus test.Results Under transmission electron microscope,experiment group showed disorganized microvilli of intestinal epithelial cells with partially twisted,broken and lost,unclear tight junctions,and widened cellular space.Under light scope,experiment group showed substantial inflammatory cell infiltration in the intestinal wall,disorganized intestinal villi,edema and hemorrhage of mucosa and submucosa,and edematous goblet cells.Experimental versus control group showed significant reduction in levels of Claudin-1 (0.587 7 ±0.060 6 vs.0.677 2 ±0.038 3),Occludin (0.1277±0.0857vs.0.4306±0.0869) and ZO-1 (0.393 3±0.080 8 vs.0.812 8± 0.096 3) (P ＜ 0.05).Experimental versus control group showed significantly up-regulated plasma levels of DAO [(1.61 ±0.20) U/ml vs.(0.69 ± 0.15) U/ml],I-FABP [(548.5 ± 36.8) EU/ml vs.(178.8±26.9) EU/ml] andET [(0.182±0.076) EU/mlvs.(0.091 ±0.029) EU/ml](P＜0.05).Conclusion EH can obviously impair the integrity of intestinal mucosal barrier in mice and hence induce endotoxin translocation.

Objective To survey the status of the clinical competence and meta-cognitive ability of college nursing students, to explore the correlation between the two factors, and analyze the influencing factors of baccalaureate nursing students′ clinical skills, then explore the approach of improving the clinical competence of nursing students. Methods Totally 184 nursing students from Taishan Medical University were investigated by General Information Questionnaire, Clinical Competence Test Scale, University Students Meta Cognitive Ability Scale. Results Nursing students′ average score of meta cognition was 80.48 ± 11.97, the average score of clinical competence was 121.22 ± 22.74. The meta cognitive ability and clinical competence of nursing undergraduate students both maintained at the middle level. Meta cognitive ability was positively correlated with clinical competence. To some extent, enhancing the meta cognitive ability could help students improve the clinical competence. Conclusions To understand the status and correlation between meta cognitive ability and clinical competence can guide students to learn effectively, can help teachers play a good role in teaching effectively.

Objective To explore the effects of rapid response first-aid case on bedside emergency gastroscopy hemostatic treatment. Methods A total of 52 patients with esophageal-fundal varices in liver cirrhosis from January 2014 to June 2015 were divided into control group (n=25) and experimental group (n=27). The patients of control group received the routine nursing; then we summarized the experience and mistakes of operation cooperation, optimized process;next we designed rapid response first-aid case and used in the experimental group. The blood transfusion time, goods preparation time, blood loss, blood transfusion volume were compared in two groups. Results The data of the experimental group in average bleeding to transfusion time (90. 22 ± 36. 47)min, materials preparation time (14. 66 ± 3. 48) min, the average amount of bleeding (369. 62 ± 158. 90) ml, average blood transfusion amount (322. 40 ± 117. 82) ml were lower than those of the control group [ average bleeding to blood transfusion time ( 123. 60 ± 51. 87 ) min, materials preparation time ( 22. 44 ± 2. 59 ) min, average bleeding volume ( 660. 20 ± 181. 82 ) ml, average blood transfusionamount(458.00±140.63)ml](P<0.05).Conclusions Theimplementationofrapidresponse first-aid case can effectively shorten the rescue time, reduce bleeding and blood transfusion time, the blood loss, the wastage of human resources and medical resources, improve the efficiency of nursing work in the department and the success rate of rescue.