[Objective]Ulnar fractures fixed by interlocking intramedullary nails or dynamic compression plates were tested to compare their biomechanical function,in order to provide the theoretical basis for clinical practice.[Method]In the experiment,12 pieces of fresh ulnars were used to produce middle-part transverse fracture models;which were fixed by interlocking intramedullary nails or six-hole 3.5 mm dynamic compression plates seperately.The diameter of intramedullary nail was 4mm,and the length was 200-230mm.The specimen was set on the MTS test machine.The rigidity and strength of ulnar fractures fixed by interlocking intramedullary nails were compared with those of ulnar fractures fixed by six-hole 3.5 mm dynamic compression plates in the anti-axial test,anti-bending test,anti-torsional test.[Result]In the anti-axial test,anti-bending test and anti-torsional test,the rigidity of ulnar fractures fixed by interlocking intramedullary nails was 450.00?38.42 N/mm,45.64?5.24 N?cm/Deg,11.42?1.21N?cm/Deg in sequence;while the rigidity fixed by dynamic compression plates was 405.40?29.26 N/mm,41.00?4.78 N.cm/Deg,10.05?1.32 N?cm/Deg accordingly.Burdened 1000N axial pressure,the displacement of interlocking intramedullay nail fixing specimen was 2.20?0.11 mm,and the compression plate fixing specimen was 2.48?0.15 mm.Given a 5 N?M bending burden,the maximum radial bending degree of interlocking intramedullay nailfixing specimen was 3.25?0.15 mm,which was 3.60?0.21 mm of compression plate fixing specimen.In the anti-torsional test,the interlocking intramedullay nail and compression plate fixing specimen could burden 2.40?0.13 N?M and 1.90?0.10 N?M respectively.The experimental data were analyzed by software SPSS.10,which came to a distinguished difference by t-test(P

Objective To describe the design and application of a new fork interlocking in-tramedullary nail(FLN).Methods The anti-compression,anti-bendin g,anti-torsion and rigidity of the FLN were compared with those of recta ngle nail(RN),plum blossom nail(PBN),Ender nail(EN),GK nail(GK)and 8-hole plate biomechanically an d 169case of tibial fractures treate d with the FLN from September1998to May 2001were reviewed.Results The anti-compression,anti-bendin g,anti-torsion and rigidity of the FLN were similar to those of GK and significantly stronger than those o f RN,PBN,EN and 8-hole plate.Of 169cases,147were followed up for more than 3months.Among them,97nails have been removed.The average healing period was 19.6week s(11-31weeks)and the complications include 5exte rnal rotation deformities(from 10?to 15?),4valgus deformities,2varus deform ities,6shortening-displacements,16pain at the nail-entry points,1common peroneal nerve injury(healed 3months later)and 3delayed postoperative infection(1case one month later,2cases five mo nths later).The infection rate was 1.6%.Based o n Johner and Wruhs standard,the excellent ra te was 96.5%,fair 1.3%and failure 2.2%respectively.Conclusion1)FLN is an effective and convenient im plant to treat tibial fracture.2)In severely comminuted fractures an d distal shaft fractures,the distal h ole could be inserted with two transv erse screws similar to GK,which can widen its indication.[

BACKGROUND: Absorbable materials for internal fixation have some advantages such as simple surgery, rapid recovery and no need to second surgery, and have been accepted in the circle of orthopaedics, and had been applied in the clinic. However, the system experiment evidences are not reliable.OBJECTIVE: To investigate whether the absorbable material (the absorbable tension band, absorbable stick or screw) is an acceptable alternative to stainless steel wire with Kirschner wire by comparing their biomechanical properties in the fixation of patella transverse fractures.DESIGN, TIME AND SETTING: The randomized controlled study of biomechanical analysis was performed at the Laboratory of Institute of Biomechanics, Shanghai University from March 2007 to January 2008.MATERIALS: Eight fresh patellae specimens were collected, with the complete patella, articular capsule and patellar ligament (3.0-4.0 cm) and quadriceps femoris (4.0-5.0 cm), and then divided into two groups at random, AO steel wire group (n = 2) and absorbable tension band group (n = 6).METHODS: Eight fresh patellae specimens were divided into two groups at random, AO steel wire group (n = 2) and absorbable tension band group (n = 6) to create models of transverse fractures, which were separately fixed by absorbable tension band,steel wire tension band + Kirschner wire to measure their biomechanics function. If fracture gap reached 1.0 mm, the fixation failed.MAIN OUTCOME MEASURES: The changes in patellar ligament tensile force, quadriceps femoris tensile force, patellar displacement, quadriceps femoris displacement, patellar ligament displacement and patella tensile strain were measured under external load.RESULTS: Under external load, no significant difference was determined in total displacement between the absorbable tension band group and AO steel wire group (9%-10% difference). No significant difference was detected in patellar strain between absorbable tension band group and AO steel wire group (9%-10% difference). The patellofemoral joint force was similar between the absorbable tension band group and AO steel wire group. When internal fixation displaced 1 mm, the load was 587 N in the absorbable tension band group, and 650 N in the AO steel wire group (P > 0.05).CONCLUSION: The absorbable material is an acceptable alternative to stainless steel wire with Kirschner wire in the fixation of patella transverse fractures, with the advantages of good biological function and good stability at the broken ends of fractured bone.

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 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 explore the value of diffusion tensor imaging (DTI) in evaluating the effects of hyperbaric oxygen therapy (HOT) in treating spinal cord injury.Methods:The modified Allen′s method was used to induce a traumatic spinal cord injury in 30 rats who were then divided randomly into an injured group and a treatment group, each of 15. The treatment group was given HOT twice a day for 3 days, then once a day for a total of 4 weeks. The injured group did not receive HOT. DTI was performed (along with Basso-Beattie-Bresnahan (BBB) evaluation) at 0h, 6h, 24h, as well as 3, 7, 14, 21 and 28 days after the operation. Two-factor repeated measures ANOVA was conducted to analyze any differences in the DTI results: the fractional anisotropy, mean apparent diffusivity, radial diffusivity and axial diffusivity, as well as the BBB scores. LSD t-tests were performed to analyze the significance of the differences at different time points.Results:At each time point after 24h the average FA value of the treatment group was significantly higher than the injured group′s average, while its average MD and RD values were significantly lower. Beyond 14 days the average AD value of the treatment group was significantly higher than that of the injured group. The treatment group′s average BBB score was also significantly higher at all the time points beyond 3 days.Conclusions:DTI results can evaluate spinal cord function and provide valuable information for the dynamic assessment of hyperbaric oxygen therapy after a traumatic spinal cord injury, and the therapy promotes the recovery of motor function, at least in rats.

Objective:To analyze the current status of body composition and development patterns of children and adolescents aged 6-17 years in Guangzhou.Methods:This was a cross-sectional study involving 8 169 school students from 3 elementary schools and 3 middle schools in Guangzhou from March to December 2019.The fat-free mass (FFM) and fat mass (FM) were measured by the bioelectrical impedance analysis.The fat-free mass index (FFMI) and fat mass index (FMI) were calculated via the height standardization. T test was used to compare quantitative variables between groups.The growth pattern of body composition was described using the Hattori chart. Results:A total of 4 431 boys (54.24%) and 3 738 girls (45.76%) were involved in this study.FFM and FM both increased with age between boys and girls.Except for boys aged 11 years, FFM in boys were significantly higher than that in girls with the same age (all P<0.05). In the age of 7-10 years, FM in boys were significantly higher than that in girls with the same age, while it was significantly higher in girls aged 12 years and older than that of boys at the same age (all P<0.05). The Hattori chart showed that the difference in body composition between genders occurred after 11 years old.In contrast to girls, increases in the weight and body mass index (BMI) in boys were mainly attributed to the FFM development. Conclusions:The development of FFM and FM in children and adolescents varies with age, accompanied with the gender-specific features.FFM in boys is higher than that of girls at the same age.The weight gain in boys is mainly attributed to the development of fat-free tissues, and thus the utility of BMI may lead to the overestimation of obesity.

Objective: To compare bioelectrical impedance analysis (BIA) and dual energy X ray absorptiometry (DXA) for measuring body mineral content (BMC) of children and adolescents, and to provide a basis for BIA to accurately measure BMC in children and adolescents. Methods: By using the convenience sampling method, among 1 469 children and adolescents aged 7-17 were recruited in Guangzhou from April to May 2019, the BMC was measured by DXA and BIA. The intraclass correlation coefficient ( ICC ) and Bland Altman analysis were used to evaluate the agreement between BIA and DXA. Bland Altman analysis was performed on log transformed data. The BMC was categorized into age and specific tertiles, and the agreement between methods was evaluated based on the kappa coefficients. Treating the BMC with DXA as the dependent variable, a prediction model was constructed for correcting the BIA measure. Results: The ICC s were 0.93 and 0.94 for boys and girls, respectively. In Bland Altman analysis, the limits of agreements for the BIA to DXA ratio were wide in boys and girls, ranging from 0.27-0.76 and 0.17-0.72, respectively. The kappa coefficients for categorized BMC levels were 0.57 and 0.45 for boys and girls, respectively, showing a fair to good degree of agreement. When sub grouped by BMI, the kappa coefficients for all BMI groups of boys and overweight girls were all >0.75 , with an excellent agreement. The prediction models for boys and girls were as follows: BMC DXA =-0.51+0.44× BMC BIA + 0.06× Age +0.02× BMI ; and BMC DXA =-0.55+0.43× BMC BIA +0.06× Age +0.02× BMI , respectively. The R 2 for models of boys and girls were 0.87 and 0.87, respectively. Conclusion The agreement between BIA and DXA was poor for measuring BMC, but acceptable when evaluating the categorized BMC levels, suggesting the BIA may be applied in assessment of the BMC levels when compared to the age and gender specific population. Additionally, the prediction model for correcting BMC by BIA fis well to the measurement by DXA.

Epidemiologic, clinical and imaging data were collected from 14 children with confirmed coronavirus disease 2019 (COVID-19) admitted in Beijing Ditan Hospital from January 27, 2020 to February 12, 2020. There were 6 boys and 8 girls with a median age of 3.5 years (6 months-9.4 years). Four patients had a history of travel to Wuhan City or Hubei Province and 2 patients had contacted with people from Wuhan; 13 patients were familial cluster of infection. The incubation period was 4 to 16 days. The clinical manifestations were fever in 8 cases, cough in 5 cases, diarrhea in 1 case; and 2 cases were asymptomatic. Four patients had abnormal peripheral blood routine, including 1 had lymphocytosis, 3 had lymphocytopenia; 3 patients had a slightly elevated CRP, and 3 patients had hepatic dysfunction. Thirteen patients underwent chest CT; and 1 case showed bilateral lung glass exudation, 1 case showed multiple patchy high density shadows of bilateral lung. One patient underwent chest X-ray examination, which was showed no abnormal findings. The pediatric patients with COVID-19 in this series generally have a traceable epidemiological history. The clinical manifestations are fever, cough and diarrhea. Peripheral white blood cell counts were most normal. Chest CT reveals less severe changes than those in adults, most child patients show no manifestation of pneumonia.