Objective To provide the scientific guidance for the prevention of lead poisoning in the children ,the lead concentra‐tions in the blood of children in Xiamen are investigated .Methods 11 271 cases of outpatients with the age of 0 -10 years old in maternity and child care hospital were surveyed randomly .The lead concentrations in the blood of these children were determined by graphite furnace atomic absorption spectrometer .Results From 2010 to 2013 ,the whole blood lead levels of 11 271 children was detected .The mean blood lead levels was 51 .0 μg/L .The boy lead poisoning rate was higher than girls in different age groups ,the difference was statistically significant (P<0 .05) .Both the above indices increased gradually with the increase of age in the range of 1-6 years old ,and the mean blood lead levels reached its peak in preschool age ,the mean blood lead did not increased in school‐age children ,and the lead poisoning rate showed the downward trend .Conclusion The lead poisoning rate of children in Xiamen is close to the average level of other cities ,however ,the blood lead level tends to increase with the increase of age .The effect of lead pollu‐tion on physical health of children shall be paid more attention to nowadays .

BACKGROUND: The biomechanical studies about calcium sulfate cement vertebroplasty are only limited to the single fracture vertebra, not performed in spinal compression fracture unit with posterior transpedicular screw fixation. Furthermore, performing experimental study in the whole function spine unit (FSU) conforms to actual clinical situation. OBJECTIVE: To assess the biomechanical properties of calcium sulfate vertebroplasty combined with posterior transpedicular screw fixation in treatment of thoracolumbar compression fractures. DESIGN, TIME AND SETTING: A controlled experiment was performed at the Biomechanical Laboratory of Shanghai University in March 2009. MATERIALS: Fifteen fresh thoracolumbar spines were harvested from male calves and made into T_(11)-L_1 FSU, then divided into 3 groups randomly: normal control group, posterior transpedicular screw fixation group and transpedicular screw fixation plus vertebroplasty group. METHODS: T_(12) flexion-compression fracture models were made in all specimens of posterior transpedicular screw fixation group and transpedicular screw fixation plus vertebroplasty group, undergoing reduction and posterior transpedicular screw fixation, and calcium sulfate vertebroplasty combined with posterior transpedicular screw fixation respectively. MAIN OUTCOME MEASURES: All specimens were placed on the WE-10A universal testing machine for mechanical test. Load-straining, load-displacing, rigidity, strength and torsion of the FSU were performed in axial compression, flexion, extension and lateral bending states. The experimental outcomes were collected and compared by statistic analysis. RESULTS: The load-strain and loed-displacement showed a linear relationship. Straining values in vertebral body and intervertebral disc of calcium sulfate vertebroplasty plus posterior transpedicular screw fixation group were 14% and 12% less than that of posterior transpedicular screw fixation group, 21% and 13% less than that of normal control group. The thoracolumbar displacement in calcium sulfate vertebroplasty Plus posterior transpedicular screw fixation group decreased 25% and 37% as compared with other 2 groups respectively. Compared with normal control and posterior transpedicular screw fixation group, the thoracolumbar stiffness in calcium sulfate vertebroplasty plus posterior transpedicular screw fixation group increased 53% and 44% respectively. The strength in vertebral body and intervertebral disc of calcium sulfate vertebroplasty plus posterior transpedicular screw fixation group were 14% and 24% higher than that of posterior transpedicular screw fixation group, 13% and 20% higher than that of normal control group. The maximal twisting strength of FSU in calcium sulfate vertebroplasty plus posterior transpedicular screw fixation group were 18% and 30% higher than that of other 2 groups, the twisting stiffness were 30% and 40% higher than that of other 2 groups. The data above were significant differences statistically (P < 0.05). CONCLUSION: Posterior transpedicular screw fixation combined with calcium sulfate vertebroplasty show superior biomechanical properties for treatment of thoracolumbar compression fractures, which exhibits not only strong strength and stiffness, but also stable FSU, thus could decrease the stress loading of the internal fixation, the incidences of screw breakage and avoid the altitude loss of vertebral body.

BACKGROUND:Searching for a porous three-dimensional (3D) scaffold holding good porosity, mechanical property and biocompatibility has become a hot spot, in which, 3D printing technology also plays apart. OBJECTIVE:To prepare silk fibroin/col agen scaffolds using 3D printing technology and detect its performance. METHODS:Silk fibroin/col agen scaffolds were constructed using 3D printing technology, and the silk fibroin/col agen mass ratio was 4:2 (group A) and 4:4 (group B), respectively. The porosity, water absorption expansion rate, mechanical properties and pore size of the composite scaffolds were detected. The passage 3 rat bone marrow mesenchymal stem cel s were seeded onto the two scaffolds. The cel proliferation was detected using MTT assay at 13 days of culture, and the cel morphology was observed by hematoxylin-eosin staining and scanning electron microscope at 14 days of culture. RESULTS AND CONCLUSION:The porosity, pore size, and water absorption expansion rate of group A were significantly larger than those of group B (P<0.05), while the elasticity modulus showed no significant difference between groups. Bone marrow mesenchymal stem cel s on the two scaffolds increased gradual y with time, especial y in the group A (P<0.05). Abundant cel s distributed evenly in the group A, while few cel s distributed unevenly in the group B. These results suggest that the 3D printed scaffolds composed by silk fibroin/col agen mass ratio of 4:2 holds good physicochemical performance and cytocompatibility.

BACKGROUND: Femoral head necrosis can be induced in adult rabbits when a large dose of steroid has been used for a long time. However, the pathogenesis of steroid-induced femoral head necrosis needs further study.OBJECTIVE: To probe into the mechanism of the disease by light microscope and transmission microscope from morphological perspective based on the model of femoral head necrosis in rabbits.DESIGN: A randomized controlled observation.SETTING: Laboratory of Morphology; Teaching and Research Division of Pathology; Laboratory of Surgery, Weifang Medical College.MATERIALS: The experiment was carried out at the Experimental Center of Morphology, Weifang Medical College, between March 2002 and March 2003. Totally 40 adult New Zealand white rabbits were randomly divided into control group (n=10), dexamethasone group (n=10) and horse serum group (n=20).METHODS: Control group was given intravenous injection of normal saline of 10 mL/(kg·d) for 7 consecutive days. Dexamethasone group was given intramuscular injection of dexamethasone of 10 mL/(kg ·d)for 7consecutive days. Horse serum group was given intravenous administration of horse serum of 10 mL/kg; 3 weeks later the same volume of horse serum was injected once again, followed intramuscular injection of dexamethasone of 10 mL/(kg·d)for 7 consecutive days. Inferior sections of cartilage of the femoral head necrosis in the experimental animals were obtained 5 and 10weeks later, and then histological and ultrastructural changes were observed under the light microscope and transmission microscope.MAIN OUTCOME MEASURES: ① Histo-morphological observation of the animals in each group. ② Ultrastructural changes.RESULTS: All the experimental animals survived and entered the result analysis. ① Histo-morphological observation: The cells of inferior sections of cartilage of the femoral head necrosis of the experimental animals in control group were arranged regularly and had a small volume of elliptical bone cells. The cell body was located at bone lacuna, blood vessel arranged well in the medullary cavity of bone. Lesion haracteristics of femoral head in dexamethasone group and horse serum group were similar:Hematopoietic adipose in the medullary cavity of bone was significantly decreased while fat adipose obviously increased; bone trabecula of metaphysis and the inferior sections of cartilage of femoral head were found with ered, and so was the bone nucleus. The number of lacuna of bone was increased. ② Ultrastructural changes: Normal bone cells in control group were elliptical, located at bone lacuna. Nucleus was at one end of the cell with complete karyotheca and many mitochondria in the cytoplasm. In dexamethasone group and horse serum group there were lipid droplets in the osteocytes, narrowed blood capillary in the medullary cavity of bone and injured vascular endothelial cells.CONCLUSION: Corticotropin can induce necrosis of femoral head; the hormone causes accumulated fat adipose in the medullary cavity of bone.The increased internal pressure in the medullary cavity leads to ischemia of femoral head, thus inducing the necrosis of osteocytes.

Objective To explore the curative effect and adverse reactions through Cynergy dual wavelength laser to cure skin vascular pathological changes in children.Methods Cynergy dual wavelength (595 nm and 1064 nm) laser were used to treat the skin vascular pathological changes in children (650 cases) including strawberry-shaped hemangioma (398 cases) and port wine stain (252 cases).Anergy density was 5-15 J/cm2 and 30-80 J/cm2.The curative effect and adverse reaction and also the relationship between the port wine stain curative effect and the age of patient,location,and colour of skin lesions were analyzed.Results In total 650 cases after 3-7 times treatments under suitable pulse width and energy density,the curative effect for strawberry-shaped hemangioma was 92.2 ％,that for pink type port wine stain was 77.9 ％,that for purple type port wine stain was 38.9 ％,and that for thickening type port wine stain was 14.3 ％ ; the overall adverse reaction rate was 2.3 ％.After test with x2 analysis,the curative effect of port wine stain also varied depending on the age of patient,location,and colour of skin lesions.The younger the age of patient and shallower of colour of skin lesions,and the better the curative effect.The curative effect for location around the eyes was better than frontal face and limbs.Conclusions Application of Cynergy dual wavelength laser in treatment of the skin vascular pathological changes in children has notable curative effect and low adverse reaction.It is a new curative technology and also safe and reliable.It is worthy of popularization and application.

ObjectiveTo observe the effects of different angles between tibial tunnel and tibial platform on “killer turn” in posterior cruciate ligament (PCL) reconstruction,and primarily discuss a safe and reasonable tunnel technology. Methods Eighteen fresh tendon grafts were used to reconstruct the PCL on the tibial side of fresh cadavers.The tibial tunnels of all specimens were built via anteromedial approach.Based on the different angles between tibial tunnel and tibial platform,all specimens were divided into Group A (30°),Group B (40°) and Group C (50°),with six specimens in each group.Area of tibial tunnel exit,pressure of tibia tunnel exit and circulation characteristics of tendons under the cyclic load before and after biomechanical test were recorded.ResultsThe area of tibial tunnel exit had statistical difference among three groups after the test ( F =8.80,P ＜ 0.05 ).The pressure of tibial tunnel exit had statistical difference among three groups (F =3.91,P ＜ 0.05 ).The cyclic frequency and fatigue strength of the transplanted tendons had statistical difference among three groups under the same cyclic load ( 256 N ) and same frequency ( 126 Hz ) ( F =4.25,P ＜ 0.05 ).Conclusions The angle between tibial tunnel and tibial platform has negative correlation with the area and pressure of tibial tunnel exit,and has positive correlation with the cyclic frequency and fatigue strength of the transplanted tendons under cyclic load.The ideal anatomy position of the tibial tunnel is the anteromedial tunnel with the angle of 40° between the tibial tunnel and the tibial platform.

Objective To quantify the expressions of tumor necrosis factor-α (TNF-α),caspase-8 and caspase-3 in lichen planus (LP) lesions,and to investigate their significance.Methods Skin samples were collected from the lesions of 20 patients with LP and normal skin of 20 healthy human controls.Immunohistochemistry was used to determine the expressions of TNF-αt,caspase-8 and caspase-3,and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end-labeling (TUNEL) technique to evaluate the apoptosis in keratinocytes,in these samples.Results The expression levels (expressed in integrated optical density,IOD)of TNF-α,caspase-8 and caspase-3 were (12.58 ± 2.33) × 103,(11.69 ± 3.52) × 103 and (11.45 ± 2.82) × 103 respectively in LP lesions,significantly higher than those in the normal skin ((5.12 ± 1.78) × 103,(3.87 ± 3.36)× 103,(4.76 ± 1.93) × 103,t =11.38,7.19,8.76,respectively,all P ＜ 0.01).Elevated apoptosis index was noted in keratinocytes from LP lesions compared with those from normal skin (71.35 ± 7.93 vs.33.62 ± 8.75,t =14.29,P ＜ 0.01).In LP lesions,the expressions of both TNF-α and caspase-8 were positively correlated with the apoptosis index of keratinocytes (r =0.72,0.75,respectively,both P ＜ 0.01) and the expression of caspase-3 (r =0.68,0.73,respectively,both P ＜ 0.01).Conclusion The up-regulated expressions of TNF-α,caspase-8 and caspase-3 may participate in the apoptosis in keratinocytes in LP.

Objective:To investigate the effect of Budesonide (BUD) on pulmonary vascular development and the expression of vascular endothelial growth factor (VEGF) and nucleotide binding oligomerization domain-like receptor protein 3 (NLRP3) in newborn rats with bronchopulmonary dysplasia (BPD) caused by intrauterine infection.Methods:The 15-day-pregnant SD rats were divided into control group and infection group [intraperitoneal injection of 0.35 mg/(kg·d) lipopolysaccharide], and the newborn rats born by the above groups were divided into 3 groups: BUD group (0.5 mg of BUD suspension), normal control group (NC group, equal amount of 9 g/L saline), BPD group (equal amount of 9 g/L saline), with 40 rats in each group, all of them were inhaled twice a day for 14 days.Ten newborn rats were selected at birth, on the 3 rd, 7 th and 14 th day after administration.Pulmonary histopathological changes and radial alveolar counts (RAC) were observed after HE staining, and the thickness of alveolar respiratory membrane was measured; the platelet-endothelial cell adhesion molecule (PECAM-1/CD 31) in lung tissue was detected by immunohistochemistry, and the density of pulmonary microvessels was calculated; the expressions of VEGF, NLRP3 and Caspase-1 were detected by Western blot; and the levels of serum interleukin( IL)-1β and IL-18 were measured by enzyme-linked immunosorbent assay. Results:With the increase of day-old, the lung tissue of newborn rats in NC group was gradually developed and matured, the structure of alveoli was clear, the size was uniform, the count was significantly increased, and no obvious pathological changes were observed.In BPD group, the lung tissue structure was disordered, the alveoli were different in size and few in count, and inflammatory cells were exuded from the alveoli or the alveoli space.Compared with BPD group, the pathological changes of lung tissue in BUD group were significantly reduced.On the 3 rd, 7 th and 14 th day after administration, compared with NC group, the RAC, average integral optical density of CD 31 positive cells, density of pulmonary microvessel and level of VEGF protein in lung tissue of BPD group and BUD group were lower, and the differences were statistically significant (all P<0.05); while the thickness of respiratory membrane, level of NLRP3, Caspase-1 proteins in lung tissue and serum levels of IL-1β, IL-18 were significantly higher, and the differences were statistically significant(all P<0.05). Compared with BPD group, the RAC, average integral optical density of CD 31 positive cells, density of pulmonary microvessel and level of VEGF protein in lung tissue of BPD group and BUD group were significantly higher, and the differences were statistically significant (all P<0.05); while the thickness of respiratory membrane, level of NLRP3, Caspase-1 proteins in lung tissue and serum levels of IL-1β, IL-18 were significantly lower, and the differences were statistically significant (all P<0.05). Conclusions:The occurrence and development of pathological changes of BPD newborn rats caused by intrauterine infection can affect the development of pulmonary vessels through the inflammatory response of lung tissue.BUD can alleviate pathological changes in lung tissues of BPD newborn rats by reducing inflammatory reaction and up-regulating VEGF expression, promoting pulmonary vascular remodeling, and increasing pulmonary microvascular density.

Objective To compare the effect of nursing students acting as social volunteers to participate in gerontological nursing practice teaching with traditional practice teaching mode, and promote the reform of teaching mode in nursing practice. Methods Students of two classes from department of nursing, medical college of Wuhan University of Science and Technology were selected as research objects. In class one nursing students acted as social volunteers to participate in gerontological nursing practice teaching (the experimental group), In class two nursing students took practice in geriatric wards according to traditional practice mode(the control group). The practice effect was compared between two groups. Results The average final grade of the experimental group was 86.50, and 78.51 in the control group. Ridit analysis revealed that, setting class one as the experimental group, R=0.796 8,95% confidence interval was 0.715 1-0.878 4, in the control group, R =0.500 0. The investigation showed that the experimental group and the control group were different in moral elevation aspect, teaching level, capability improving aspect and employment promotion aspect, the difference was significant (P<0.01). Conclusions The mode of nursing students acting as social volunteers to participate in gerontological nursing practice teaching has advantage over traditional practice teaching, and it can gain satisfying teaching effect.

Objective To investigate a diabetic retinopathy ( DR ) detection algorithm based on transfer learning in small sample dataset. Methods Total of 4465 fundus color photographs taken by Gaoyao People ' s Hospital was used as the full dataset. The model training strategies using fixed pre-trained parameters and fine-tuning pre-trained parameters were used as the transfer learning group to compare with the non-transfer learning strategy that randomly initializes parameters. These three training strategies were applied to the training of three deep learning networks:ResNet50,Inception V3 and NASNet. In addition,a small dataset randomly extracted from the full dataset was used to study the impact of the reduction of training data on different strategies. The accuracy and training time of the diagnostic model were used to analyze the performance of different training strategies. Results The best results in different network architectures were chosen. The accuracy of the model obtained by fine-tuning pre-training parameters strategy was 90. 9％,which was higher than the strategy of fixed pre-training parameters (88. 1％) and the strategy of randomly initializing parameters ( 88. 4％) . The training time for fixed pre-training parameters was 10 minutes,less than the strategy of fine-tuning pre-training parameters ( 16 hours ) and the strategy of randomly initializing parameters (24 hours). After the training data was reduced,the accuracy of the model obtained by the strategy of randomly initializing parameters decreased by 8. 6％ on average,while the accuracy of the transfer learning group decreased by 2. 5％ on average. Conclusions The proposed automated and novel DR detection algorithm based on fine-tune and NASNet structure maintains high accuracy in small sample dataset,is found to be robust,and effective for the preliminary diagnosis of DR.