Objective: To explore the applicability of semi-quantitative risk assessment methods in wood furniture manufacturing companies. Methods: Two medium-sized wooden furniture manufactures were randomly selected as research objects, namely A company and B company. Used the Semi-Quantitative risk assessment method (the ratio method, the index method and the comprehensive method) in the "Guidelines for occupational health risk assessment of chemicals in the workplace" (GBZ/T 298-2017) to conduct occupational hygiene survey, occupational hazard factor testing and occupational health risk assessments for two wood furniture manufacturers from January to October 2018, and compared and analyzed the applicability of these three semi-quantitative risk assessment methods in wooden furniture manufacturing enterprises. Results: The occupational health status of A enterprises was worse than that of B enterprises, and the occupational health risk level was higher than that of B enterprises, and the risk level of A enterprise is 3~4, and the risk level of B enterprise is 2~3. The occupational health risk level obtained by the index method was consistent with the comprehensive method, while the risk level of some occupational disease hazards used the ratio method was inconsistent with the results of the index method and the comprehensive method. Compared with the index method and the comprehensive method, when E/OEL<0.5 or E/OEL≥2, there might be a certain fluctuation in the occupational health risk level obtained by the ratio method. Conclusion The semi-quantitative risk assessment is more objective, comprehensive and flexible in the application of occupational health risk assessment, and can assess the occupational health risk level of chemical poisons in wood furniture manufacturing enterprises.

Objective To study the effect of diffusion-weighted magnetic resonance imaging (DW-MRI) in the differential diagnosis of hydronephrosis and pyonephrosis.Methods From March 2015 to October 2017,50 patients with renal stone and highly suspected infectious hydronephrosis underwent renal DW-MRI,and clinical materials were collected and analyzed retrospectively.Seventeen male and 33 female patients were enrolled with a mean age of (49.40 ±-10.51) years.The median maximum diameter of renal stone was 30.30 (17.38,56.01) mm and hydronephrosis was 46.39 (34.33,56.55) mm.No pyonephrosis was diagnosed by preoperative ultrasound or CT,while 29 cases of hydronephrosis and 21 cases of pyonephrosis were reported by preoperative DW-MRI.Final diagnoses of hydronephrosis and pyonephrosis were made according to whether the pelvic urine drainage was purulent or not during the surgery.DW-MRI reports and characteristics of DW images were analyzed retrospectively.Apparent diffusion coefficient (ADC) was calculated and ADC map constructed,which was compared between the two groups.Receiver operating characteristic curve (ROC) was drawn to analyze the area under curve (AUC) and the optimal cutoff of ADC value,with sensitivity and specificity.Results Thirty-three patients of hydronephrosis and 17 pyonephrosis were confirmed intraoperatively.The overall accuracy of diagnosis using DW-MRI was 84.00％ (42/50),with sensitivity of 88.24％ (15/17) and specificity of 81.82％ (27/33).Among 30 patients who underwent CT scan in our hospital,mean CT value of 18 hydronephrosis was (7.03 ± 3.26)HU and that of 12 pyonephrosis was (8.67 ± 3.52) HU,with no statistical significance (P ＞ 0.05).On DW image,when b ≥ 500 s/mm2,hydronephrosis signal intensity was lowered apparently,whereas pyonephrosis signal intensity was intensified.On ADC map,hydronephrosis appeared as hyperintensity,whereas pyonephrosis appeared as hypointensity.The mean ADC value of pyonephrosis group was lower than hydronephrosis group [(1.53 ±0.58) × 10-3 mm2/s vs.(2.86 ±0.56) × 10-3 mm2/s,p ＜0.01].ROC analysis revealed that AUC =0.92 (95％ CI 0.80-0.98),and the cut-off value of ADC for pyonephrosis diagnosis was 1.39 × 10-3 mm2/s,of which the sensitivity and specificity was 94.12％ and 84.85％ respectively.Conclusions Signal of pyonephrosis was enhanced on DW image,while decreased on ADC image.The ADC value of pyonephrosis was much lower than that of hydronephrosis,with which the differential diagnosis between pyonephrosis and hydronephrosis could be made efficiently.

BACKGROUND:In literatures, the recombinant human bone morphogenetic protein-2 (rhBMP-2) loaded microcapsules can be fabricated by double emulsion solvent evaporation method with different organic solvents, such as methylene chloride, ethyl acetate or their mixture. But so far it is not determined yet which one is better. OBJECTIVE: To optimize the preparation method of microcapsules encapsulating rhBMP-2 and to compare the effects of different organic solvents on the microcapsules. METHODS:Polylactic acid-polyethylene glycol-polylactic acid copolymer as microcapsules was used to prepare rhBMP-2 loaded microcapsules with double emulsion solvent evaporation method. Four kinds of organic solvents, methylene chloride (group A), mixture of methylene chloride and ethyl acetate (group B), ethyl acetate (group C) and acetyl acetone (group D) were chosen as oil phases to compare their effects on microcapsule's morphology, diameter, and encapsulation efficiency. Passage 3 bone marrow mesenchymal stem cels from rats were co-cultured with prepared microcapsules for 14 days, and then alkaline phosphatase activity was detected. RESULTS AND CONCLUSION:Compared with the other organic solvents, dichloromethane could cause microcapsules with the smaler and more uniform shape (4-10 microns) and the highest encapsulation efficiency; the microcapsules prepared by mixture of methylene chloride and ethyl acetate had relatively wide size distribution and moderate encapsulation efficiency; the microcapsules prepared by acetylacetone were difficult to form and keep the bioactivity of rhBMP-2. After cultured with rat bone marrow mesenchymal stem cels for 14 days, the alkaline phosphatase activity in groups A, B and C was significantly higher than that in group D and there was no significant difference between group A and group B; the alkaline phosphatase activity in groups A and B was significantly higher than that in group C (P< 0.05). The results show the rhBMP-2-loaded microcapsules prepared by methylene chloride as organic solvent have good shape, high encapsulation efficiency, and good biological activity.

OBJECTIVETo analyze the risk factors of nonspecific low back pain in community populations.

METHODSTwo community populations were investigated using questionnaires in this case-control study. The questionnaire was designed to collect data including age, gender, body weight, marriage, education, income, occupation, labor intensity, smoking, alcohol drinking and social mental status. The subjects with low back pain constituted the case group and those without low back pain served as the control group, and the data was analyzed by a Logistic regression model.

RESULTSA total of 1747 community residents participated in this survey, among whom 398 subjects had low back pain and 1126 subjects without low back pain were selected as the control group. Of all the latent risk factors of low back pain in Logistic regression model, gender was the most relevant factor (OR=3.5522) followed by education (OR=1.958), labor intensity (OR=1.956), marital status (OR=1.612), vibration source exposure (OR=1.491), BMI (OR=1.127) and age (OR=1.060).

CONCLUSIONGender, education, labor intensity, marriage, vibration source exposure and BMI are risk factors of nonspecific low back pain in community populations, and exercises and mental status can be protective factors against low back pain.

Case-Control Studies ; Humans ; Logistic Models ; Low Back Pain ; epidemiology ; Risk Factors ; Surveys and Questionnaires

Objective To analyze the risk factors of nonspecific low back pain in community populations. Methods Two community populations were investigated using questionnaires in this case-control study. The questionnaire was designed to collect data including age, gender, body weight, marriage, education, income, occupation, labor intensity, smoking, alcohol drinking and social mental status. The subjects with low back pain constituted the case group and those without low back pain served as the control group, and the data was analyzed by a Logistic regression model. Results A total of 1747 community residents participated in this survey, among whom 398 subjects had low back pain and 1126 subjects without low back pain were selected as the control group. Of all the latent risk factors of low back pain in Logistic regression model, gender was the most relevant factor (OR=3.5522) followed by education (OR=1.958), labor intensity (OR=1.956), marital status (OR=1.612), vibration source exposure (OR=1.491), BMI (OR=1.127) and age (OR=1.060). Conclusion Gender, education, labor intensity, marriage, vibration source exposure and BMI are risk factors of nonspecific low back pain in community populations, and exercises and mental status can be protective factors against low back pain.

Objective To analyze the risk factors of nonspecific low back pain in community populations. Methods Two community populations were investigated using questionnaires in this case-control study. The questionnaire was designed to collect data including age, gender, body weight, marriage, education, income, occupation, labor intensity, smoking, alcohol drinking and social mental status. The subjects with low back pain constituted the case group and those without low back pain served as the control group, and the data was analyzed by a Logistic regression model. Results A total of 1747 community residents participated in this survey, among whom 398 subjects had low back pain and 1126 subjects without low back pain were selected as the control group. Of all the latent risk factors of low back pain in Logistic regression model, gender was the most relevant factor (OR=3.5522) followed by education (OR=1.958), labor intensity (OR=1.956), marital status (OR=1.612), vibration source exposure (OR=1.491), BMI (OR=1.127) and age (OR=1.060). Conclusion Gender, education, labor intensity, marriage, vibration source exposure and BMI are risk factors of nonspecific low back pain in community populations, and exercises and mental status can be protective factors against low back pain.

OBJECTIVETo summarize the techniques and evaluate the therapeutic effect of posterior fixation and fusion in the treatment of Os odontoideum complicated by atlantoaxial dislocation.

METHODSFrom March, 2007 to October, 2010, 10 patients with Os odontoideum (including 6 male and 4 female patients aged from 20 to 65 years, mean 39.8 years) were treated in our hospital. Before and after the operation, the patients underwent X ray, CT and MRI examinations to measure and evaluate the degree of dislocation and neural compression. After preoperative traction for 1-2 weeks, all the 10 patients showed deductible atlantoaxial dislocation. Through a posterior approach, Atlantoaxial pedicle screws fixation were performed in 9 cases, and C2/3 pedicle-Occiput screw fixation was performed in 1 case. All the patients wore cervical collars as external support for 3 months after the operation.

RESULTSThe mean operative time was 3 h in these patients with a mean intraoperative blood loss of 420 ml. The symptoms were relieved after the surgery in all the patients, who showed no neck pain or neurological defects. The patients were followed up for 6 to 52 months (mean 22 months), and bony fusion was observed in all the 10 cases within 6 to 8 months without such complications as internal fixation failure or redislocation of the atlas.

CONCLUSIONPatients with Os odontoideum complicated by atlantoaxial dislocation should undergo surgical stabilization to avoid severe neurological injury. Pedicle screw instrument in the atlas allows restoration of the spinal stability, short-segment fusion, and maximal preservation of the mobility of the neck.

Adult ; Aged ; Atlanto-Axial Joint ; injuries ; Bone Transplantation ; Female ; Fracture Fixation, Internal ; methods ; Humans ; Joint Dislocations ; complications ; surgery ; Joint Loose Bodies ; complications ; surgery ; Male ; Middle Aged ; Odontoid Process ; pathology ; Spinal Fusion ; methods ; Treatment Outcome ; Young Adult

Objective To study the effects of rehabilitation training combined with the transplantation of bone marrow mesenchymal stem cells-derived neural stem cells (BMSC-D-NSCs) on the expression of Nogo-A and NgR protein in rats after spinal cord injury (SCI).Methods The spinal cords of eighty Sprague-Dawley rats were injured using a modified Allen′s impactor (H = 25 mm) at T10. The injured rats were randomly divided into a combination therapy group which was given rehabilitation training and cell transplants, a cell graft group, a rehabilitation training group and a control group. At the 7th day post SCI, BMSC-D-NSCs were transplanted into the injured spinal cords of the rats in the combination therapy and cell graft groups. Hindlimb movement was assessed using the BassoBeattie-Bresnahan (BBB) scale every week, and protein was extracted from the injured spinal cord tissue for Nogo-A and NgR determination by Western blotting at the 1st, 3rd and 7th day after cell transplantation.Results The average BBB score of the rats in the combination therapy group was significantly higher than that of the other groups from 2 weeks post transplantation. The scores in the rehabilitation training group were significantly higher than in the control group from the 5th week post transplantation. Western blotting showed high expression of Nogo-A and NgR protein 24 h post surgery, but these declined with time. For Nogo-A there was a significant difference among the groups at all three time points. In the combination therapy group the expression declined to a minimum by the 7th day. For NgR protein there was no significant difference between the 1st and 3rd day in any group.Conclusions Rehabilitation training combined with BMSC-D-NSC transplantation can have a synergistic effect on functional recovery from SCI. It can down regulate the expression of Nogo-A and NgR protein.

The degradable performance and bio-mineralization function of PLA-PEG-PLA/PLA tissue engineering scaffolds in vitro and in vivo were systematically studied. The X-ray diffraction and Fourier transform infrared spectra showed that there was the deposition of bone-like carbonate hydroxyapatite on the surface of scaffolds. We found that the weight of scaffolds did not always decrease with the prolongation of time in vitro. At the same time, we found that after the PLA-PEG-PLA/PLA tissue engineering scaffolds were embedded in skulls of rhesus monkeys, the new bone area reached 75% at the 12th week. Histological observation showed that the new bones were rebuilt and knitted bones were formed at the 12th week. These findings meant that the PLA-PEG-PLA/PLA tissue engineering scaffolds were potential in clinical use.
Animals ; Biocompatible Materials ; chemistry ; Bone Regeneration ; Bone Substitutes ; chemistry ; Implants, Experimental ; Macaca mulatta ; Polyethylene Glycols ; chemistry ; Polymers ; chemistry ; Skull ; drug effects ; physiology ; Tissue Engineering ; methods ; Tissue Scaffolds ; chemistry

BACKGROUND: Thoracolumbar burst fracture Dennis type B does not have significant damage in the intervertebral discs of the inferior vertebral body. To reduce fusion segment and remain normal intercalated disc, single discectomy (damaged vertebral body and supervisor vertebral body) is proposed, but because of the damage to the vertebral body, implanted screw is easy to loose following excising partial vertebral body, even cannot be fixed. However, it is still unknown whether implanted screw in the inferior vertebral body of the damaged vertebral body was stabilized using two segment discectomy with fixation.OBJECTIVE: To analyze the feasibility of single segmental spinal interbody fusion with bisegment fixation for thoracolumbar burst fracture type B.DESIGN, TIME AND SETTING: The randomized controlled in vitro study was conducted at the Laboratory of Biomechanics, Southern Medical University from June 2007 to June 2008.MATERIALS: A total of 20 fresh freezing 7-9 months pig samples (T_(13)?L_3 segment) were used, comprising 10 integral samples and 10 L_1 type B thoracolumbar burst fracture samples prepared by pre-injury and weight dropping technique.METHODS: Pig fresh thoracolumbar specimens from T_(13)?L_3 were collected to create models of type B thoracolumbar burst fracture. There were 4 groups in this study. Ten of them were selected as intact group (n=10) (fresh pig T_(13)?L_3 segment). T_1 vertebral endplate pre-injury and weight dropping technique and incremental trauma approach were used. Denis' type B burst fracture was produced, and ten of them were selected as unstable group (n=10). Firstly, unstable group was decompressed by discectomy and semivertebraectomy in upper half of the vertebral body, single level was fused with iliac and U-FRONT anterior thoracolumbar system were placed between T_(14) and L_2, as single discectomy with fixation group (n=10). Then lower disc of injury vertebra discectomy and vertebraectomy, fused with iliac U-FRONT anterior thoracolumbar system were placed between T_(14) and L_2, as two segment discectomy with fixation group (n=10). The bone graft was longer 1 mm than the bone graft region.MAIN OUTCOME MEASURES: The flexion, extension, right/left lateral bending, and right/left axial rotation range of motion (ROM) of T_(14)?L_2 were measured in each group on the spinal three-motional test machine at 10 N穖.RESULTS: The flexion, extension, right/left lateral bending, and right/left axial rotation were not stable in the unstable group.ROM was significantly increased in the unstable group compared with the intact group (P< 0.01). The primary stability was significantly elevated in the single discectomy with fixation and two segment discectomy with fixation groups. The flexion, extension, right/left lateral bending, and right/left axial rotation ROM were significantly reduced in the single discectomy with fixation and two segment discectomy with fixation groups compared with the unstable group (P < 0.05). The flexion, extension, right/left lateral bending ROM was significantly decreased in the two groups compared with the intact group, but axial rotation ROM was significantly increased (P< 0.05). Axial rotation ROM was smaller in the single discectomy with fixation group compared with the two segment discectomy with fixation group (P < 0.05).CONCLUSION: Single segmental spinal interbody fusion with bisegment fixation for thoracolumbar burst fracture type B had a good immediate stability in flexion, extension, lateral bending motion. Compared with traditional partial corpectomy L_1 between the caudal and cranial endplate of the adjacent vertebrae with bisegmental fixation, it had a better immediate stability in axial rotation.