Objective To determine the detergent-enzymatic cycles and evaluate the biomechanical characteristics as well as extracellular matrix integrity of the decellularized tracheal scaffold in rabbit.Methods Forty tracheal segments were harvested from New Zealand white rabbits.Thirty-five of tracheas were subjected to a detergent-enzymatic method of decellularization for 1/3/5/6/7/8/9 cycles,respectively,and other five were stored in phosphate-buffered saline at 4℃ as a control.Comparative examinations were performed by the macroscopic view,histological view(hematoxylin and eosin stain,Movat Pentachrome stain,4-6-diamidino-2-phenylindole),scanning electron microscope (SEM) and biomechanical properties between decellularized groups and control group.Results After 7 detergent-enzymatic cycles,almost complete decellularized tracheae,retaining the hierarchical and mechanical properties of the native tissues,could be obtained.Histological and molecular biology analysis demonstrated that all cellular components and nuclear material were removed.SEM analysis revealed that the decellularized matrices retained the hierarchical structures of native trachea,and biomechanical tests showed that decellularization approach did not led to any influence on tracheal morphological and mechanical properties.Immunofluorescence analysis show a significant reduction of nuclear material in decellularized tracheas (P ＜ 0.05).Conclusion In conclusion,this work suggests that 7 cycles of the modified DEM generates a bioengineered rabbit tracheal matrix that is structurally and mechanically similar to native trachea which could be a better selection for tracheal reconstruction with tissue engineering method.

BACKGROUND:Some studies have demonstrated that red blood celllysate added into the bone marrow can increase the efficiency of isolating and purifying mesenchymal stem cells, in order to obtain high-purity and high-quantity bone marrow mesenchymal stem cells.
OBJECTIVE:To isolate and culture bone marrow mesenchymal stem cells of rabbit with red blood celllysis in vitro for exploring proliferation characteristics and performing the biological identification of cells.
METHODS:Bone marrow suspension was col ected by puncturing the tibia with medul o-puncture needle. Red blood celllysis was added to the bone marrow suspension, and bone marrow mesenchymal stem cells were isolated and cultured. Numbers of primary cells were recorded at 4, 7, 10, and 13 days later And Growth curves of the cells at passages 2-5 were drawn for comparison of proliferative characteristics. Inverted phase contrast microscope was used to observe the morphological changes of cells. CD34, CD44 antigens of bone marrow mesenchymal stem cells were identified by flow cytometry and immunity fluorescence.
RESULTS AND CONCLUSION:The adherent bone marrow mesenchymal stem cells mainly showed s spindle shape, with homogeneous nuclei, prominent nucleoli, and rich cytoplasm, which were positive for CD44 antigen and negative for CD34 antigen. The primary cells exhibited an“S”shape. Passage 4 cells had a better proliferative ability, rapider growth and more counting of cells as compared with other generations. These findings indicate that red blood celllysis method is a feasible ways of culturing bone marrow mesenchymal stem cells 0 in vitro, and passage 4 cells have the strongest proliferation capacity.

BACKGROUND: Thoracolumbar fracture is most common seen in spinal fractures. The paraspinal muscle is subjected to extensive detachment and traction in traditional posterior approach, so the muscular ischemia and denervation lead to muscle atrophy further inducing intractable low back pain. Thereafter, minimally invasive spinal surgery becomes more and more popular.OBJECTIVE: To investigate the clinical efficacy of pedicle screw fixation through Wiltse approach combined with injectable calcium sulfate bone cement for single-level thoracolumbar fracture.METHODS: Clinical data of 52 patients with single-level thoracolumbar fracture without nerve injury were analyzed retrospectively, and were then assigned to observation (n=28) and control groups (n=24) according to the treatment method. The patients in the observation group were treated with pedicle screw fixation through Wiltse approach plus implanted with injectable calcium sulfate bone cement, and those in the control group were subjected to pedicle screw fixation through posterior approach plus implanted with injectable calcium sulfate bone cement. The operation time, blood loss and hospitalization time were compared between two groups. The low back pain was observed at baseline, 1 week and 3 months postoperatively, and the percentage of anterior vertebral height revealed on X-ray was observed at baseline, before ambulation, and during last follow-up. Moreover, the complications, loosening and rupture of the screws were recorded.RESULTS AND CONCLUSION: (1) All patients were followed up, and the follow-up time was 16-24 months. (2) The operation time, blood loss and hospitalization time in the observation group were significantly less than those in the control group (P < 0.05). (3) The postoperative visual analogue scale scores in the two groups were significantly lower than those before surgery, and the scores showed significant differences between two groups (P < 0.05). (4) The percentage of anterior vertebral height before ambulation and during last follow-up in the two groups was significantly improved, and the percentage showed significant difference between two groups at each time point (P < 0.05). (5) These findings suggest that based on strict indications, the pedicle screw fixation through Wiltse approach combined with injectable calcium sulfate bone cement is safe for single-level thoracolumbar fracture, which restores the anterior vertebral height rapidly, alleviates pain and exhibits satisfactory long-term efficacy. Furthermore, it holds shorter operation time and less blood loss than the traditional approach.

BACKGROUND:Percutaneous pedicle screw fixation has been applied in the treatment of thoracolumbar fracture,and has achieved satisfactory clinical efficacy.Injectable calcium sulfate holds good biocompatibility,degradability and fast curing.OBJECTIVE:To explore the clinical efficacy of percutaneous pedicle screw fixation combined with calcium sulfate cement for single-level thoracolumbar fracture.METHODS:Clinical data of 40 patients with single-level thoracolumbar fracture without nerve injury were analyzed retrospectively.All fractured vertebrae were compressed more than 30％ and at least one pedicle was complete.All patients were treated with percutaneous pedicle screw fixation combined with calcium sulfate cement.The Visual Analog Scale and Oswestry Disability Index scores were recorded at baseline,3 months postoperatively and last follow-up;the height of the fractured vertebra body and sagittal Cobb angle were measured on X-ray;the patient's satisfaction and healing rate were recorded.RESULTS AND CONCLUSION:(1) The Oswestry Disability Index at 3 months postoperatively and last follow-up was 16.3％ and 4.4％,respectively.Compared with baseline,the Cobb angle and Visual Analog Scale scores were significantly reduced,and height of the fractured vertebra body was significantly increased after surgery (P ＜ 0.01).(3) The healing rate at last follow-up was 95％,nonunion was not found,and the patients' satisfaction reached 95％.(4) The loss of vertebral height and Cobb angle was found at last follow-up compared with 3 months postoperatively,but had no significant difference (P ＞ 0.05).(5) These results indicate that percutaneous pedicle screw fixation combined with calcium sulfate cement is safe and reliable for single-level thoraclumbar fracture,which not only restores the vertebral height and relieves pain,but also has satisfactory long-term curative efficacy and high healing rate.

Currently,carbon nanoparticle technology is a rapidly developing and emerging technology that has a significant impact in the field of cancer treatment,especially in non-small cell lung cancer.The lymphatic tendency of nano-carbon is used to improve the detection rate of positive lymph nodes,avoiding the leakage of lymph nodes and the crushing and breaking of the lymph nodes to prevent the metastasis of tumorsin non-small cell lung cancer surgery.In addition,carbon nanoparticle has underwent tremendous changes on drug chemical treatment.Its good biocompatibility provides the possibility of serving as a drug carrier,and maintains in vivo drugs at a constant concentration to avoid affecting therapeutic efficacy owning to the half-life of the drug.At the same time,its biological toxicity is lower compared to the traditional drug carrier.This paper focuses on these characteristics of carbon nanoparticle which is applied to the lymphatic target tracking,drug control and release,and elaborates its clinical application prospect in the field of non-small cell lung cancer.

Objective: This study aimed to evaluate the validity and predictive value of different methods for myopia screening, and to provide the most effective method of myopia screening. Methods: A total of 7 441 students of grade 1-12 selected from 36 primary and middle schools in 12 counties in Jiangsu Province were enrolled in this study for ophthalmological examination, and uncorrected visual acuity (UCVA, Plan A), noncycloplegic autorefraction (NCAR, Plan B) and combination of UCVA and NCAR (Plan C) were included in the examination. Receiver operating characteristics (ROC) curve was performed to determine the cut-off values (The gold standard is cycloplegic refraction: SE≤0.5 D), and positive predictive value, sensitivities, specificities and other indicators of three screening tests were compared and calculated. Results: The AUC of the combination test for uncorrected visual acuity(UCVA) and noncycloplegic autorefraction (NCAR) was nearly 1(0.91, 95%CI=0.90-0.92), and the sensitivity, specificity, Yoden index, diagnostic coincidence rate, positive predictive value and negative predictive value were 92.4%，89.5%，0.82，91.1%，91.3%，90.8%, respectively, but the index of the younger pupils in primary schools was relatively low. The result of screening plan A for students of middle and high school students was the closest to that of myopia diagnosis. Conclusion Combination test, which was recommended by China National Health Commission, can be a practical solution for school students for myopic screening. Under the condition of no mydriatic refraction, Plan A could be considered for myopia screening especially for middle and high school students. For the younger pupils, it is suggested to use the internationally recommended myopia screening strategy, that is, SE ≤ 0.50D after mydriasis.

Abstract China has one of the world’s highest prevalence of myopia in children and adolescents, and children are developing myopia earlier. Myopia has become a important issues affecting children and adolescents health, as well as a significant public health concern. There has been continuing debate over the role of nature and nurture in the aetiology of myopia, growing evidence showed that environmental factors has a determine effect on myopia.The randomized controlled trials has assured the relationship between time outdoors and myopia. Based on reviewed published articles, survey and intervention studies and school health practices, according to the principle of school organization, student participation and family cooperation, the authors proposed outdoors activities as initiative for myopia prevention and control in children and adolescents. The detail recommendation contents, levels were list out.

Objective: The purpose of the current study was to determinate the prevalence of dating violence perpetration and victimization and to examine its relationship with childhood abuse among medical college students. Methods: Cluster sampling survey was carried out among 3 727 freshmen and sophomores in two medical colleges from Anhui Province. Information with general demographic variables, childhood abuse and dating violence was obtained. Logistic regression was used to identify the relationship of different types of childhood abuse and dating violence after controlled for confounding factors. Results: The rate of dating violence perpetration and victimization was 37.8% and 27.8%, respectively. Female students had higher childhood emotional abuse experience (61.9%) than male students (51.6%), while male students had higher childhood physical and sexual abuse (28.2% and 19.4%) than females (24.3% and 10.5%) (χ2=33.84，6.33，52.97，P<0.01). Results showed that increased dating violence perpetration [OR(95%CI)=1.71(1.48-1.98),1.55(1.33-1.82),1.75(1.43-2.15)]and victimization [OR(95%CI)=1.84(1.43-2.16),1.59(1.34-1.87),1.62(1.32-2.00)](P<0.01) among individuals with physical, emotional and sexual abuse after controlling for confounding variables. No gender difference was found within other groups in the relationship between childhood abuse and dating violence(P>0.05). Conclusion Childhood abuse experiences are associated with higher risk of dating violence perpetration and victimization among college students. Reducing childhood abuse is beneficial to the prevention and control of dating violence among medical college students.

Tissue-engineering airway reconstruction is a tracheal replacement therapy,which uses different materials,such as primary,allogeneic or synthetic,combined with seed cells and growth factors to repair the defect airway and restore its physiological function.The choice of stent graft is the key to the success or failure of airway reconstruction.By improving the performance of graft scaffolds,it has similar mechanical properties and biocompatibility with natural gas tubes,promoting vascularization and reepithelization,reducing immunogenicity and completing airway reconstruction.This article aims to review advances in the study of graft scaffolds for airway remodeling.

Objective: To explore the consumption of sugar sweetened beverages (SSBs) and its association with behavioral problems in Chinese preschool children, and to provide a scientific basis for the prevention of behavioral problems of children. Methods: A total of 7 634 children aged 3-6 years were chosen from kindergartens in 3 cities (Yangzhou, Xuzhou, Zhenjiang) in the lower reaches of Yangtze River using method of cluster sampling during October to November in 2017. Parental or guardian questionnaires were used to obtain information regarding child consumption of SSBs. The Strengths and Difficulties Questionnaire (SDQ) was used to assess children s emotional and behavioral problems. Multivariate Logistic regression model was used to explore the association between different SSBs intake frequency and children s behavioral problems. Results: A total of 5 509(72.2%) consumed SSBs less than once a day, 830(10.9%) reported SSBs consumption once a day, and 1 295(16.9%) had 2 times or more intake of sugar sweetened beverages per day. After adjusting for confounding factors including age, sex, BMI, family financial status, parental education, screen time, sleep duration, and physical activities duration, multiple Logistic regression model revealed that intake of SSBs once a day was associated with an increased risk of hyperactivity disorder ( OR =1.26, 95% CI =1.01-1.57) and SDQ total difficulties ( OR =1.44, 95% CI =1.14-1.82) in boys and with an increased risk of emotional symptoms ( OR=1.34, 95%CI =1.02-1.76), conduct problems ( OR=1.53, 95%CI =1.18-2.00), hyperactivity disorder ( OR=1.79, 95%CI =1.42-2.27) and prosocial behavior ( OR=1.48, 95%CI =1.14-1.91) in girls. Intake of SSBs≥2 times per day was associated with an increased risk of emotional symptoms ( OR=1.28, 95%CI =1.02-1.59) and SDQ difficulties ( OR=1.30, 95%CI =1.07-1.58) in boys and not with behavioral problems in girls. Conclusion Sex differences are observed with respect to the association between SSBs intake and behavioral problems in preschoolers, but no significant dose response relationship was observed. More longitudinal studies are needed to further explore the association between SSBs intake and behavioral problems in preschool children as well as the underlying physiological mechanisms in future.