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OBJECTIVE: To analyze the active surveillance results of occupational pneumoconiosis(hereinafter referred to as “pneumoconiosis”) in Beijing in 2019. METHODS: A total of 2 634 dust exposed workers were recruited as the active surveillance subjects by judgment sampling method. The abnormalities and influencing factors of High kV or digital photography of posterior-anterior chest radiography(hereinafter referred to as “chest radiography”) and lung function were analyzed. RESULTS: The detection rate of abnormal chest radiograph and pulmonary dysfunction were 14.0%(368/2 634) and 6.6%(175/2 634), respectively. The multivariate logistic regression analysis showed that the risk of abnormal chest radiograph in dust-exposed workers increased with age(P<0.01). Mining and construction workers had higher risk of abnormal chest radiograph than manufacturers(all P<0.05). The risk of abnormal chest radiograph of dusk-exposed workers in state-owned and foreign enterprises was higher than that of workers in private enterprises(P<0.05). The risk of pulmonary dysfunction was increased with age and length of dust exposure(all P<0.05). Workers exposed to silica dust and aluminum dust had higher risks than those exposed to welding dust(all P<0.01). The risk of pulmonary dysfunction of workers in small and micro enterprises was higher than that of workers in large enterprises(all P<0.01). Mining workers had higher risks of pulmonary dysfunction than manufacturing workers(P<0.05). CONCLUSION: Age, length of dust exposure, dust type, industry type, enterprise scale and economic type were the influencing factors of lung injury of dust exposed workers. Therefore, the supervision of key population and industries should be strengthened to reduce the occurrence of pneumoconiosis.
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The advantages and disadvantages of different treatment methods of traditional tibial fracture were summarized. The research progress on the treatment of tibial fracture with internal fixation plates as external fixators was introduced from two aspects of biomechanics and clinical application. It was proved that internal fixation plates as external fixators could reduce the structural stability, but this technique was still controversial to meet the mechanical requirements of fracture healing on biomechanics.Internal fixation plates as external fixators,it had the advantages of minimal invasion,high healing rate, less complications and favorable activities. It's pointed out clinical trials on its feasibility and availability as well as simulating body mechanics environment should be carried out to provide basis for relevant biomechanics researches.
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Objective To design a new type of external fixator for bone fracture and verify its rationality and feasibility. Methods The frame and screw of stainless steel achieved fracture fixation in vitro with a threaded locking structure.At the same time the increasing thickness of body frame, the inclined nail holes and the raised bottoms were designed to greatly enhance the strength and overall stability of body frame.FEM (finite element method),measuring the relative displacement and stress distribution after axial load,was used to verify the rationality of the design.An animal experiment with sheep was used to verify the feasibility of fracture treatment. Results Simulated result of FEM indicated that the biggest relative displacement between the separated bones was 0.04 mm,which was much less than the minimum value 1 mm required for fracture healing.The maximum stresses applied on the frame of the fixator,fixator screw,and bone were 35,26,and 6 MPa, respectively, which was much less than the allowable stress. In the animal experiment, fracture site was fixed firmly after operation and was well cured 3 months later.Conclusion The design of this new device is feasible and it can be used as a new method of fracture treatment.
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Objective To perform modification study of cyanoacrylate (CA) medical adhesive and to select the optimal mo-difying material and the best ratio.Methods Carboxylic multi-walled carbon nanotubes (MWCNTs-COOH), multi-walled carbon nanotubes (MWCNTs), hydrophobic nano-silica, nitrile rubber, epoxy resin and polymethyl methacrylate (PMMA) were used to modify 5% triclosan/cyanoacrylate antimicrobial adhesive respectively. The bond strength, toughness and viscosity of the modified adhesive were examined in different concentrations.Results 0.064% MWCNTs-COOH, 6% nano-silica, 4% nitrile rubber and 6.4% epoxy resin all had good effects in strength modification. The bond strength were (14.71±1.48)MPa, (14.03±1.92)MPa, (14.6±1.78)MPa and (14.05±1.46)MPa respectively. 8% nano-silica had the lowest Tg of (1.1±0.24)℃ and the strongest viscosity of (15 536.68±28.4)cP. When the nano-silica concentration was 8%, the compound was very viscous and sticky. When the antimicrobial adhesive modified with 6% nano-silica, the bond strength was (14.03±1.92)MPa, the Tg was (3.6±0.68)℃, and the viscosity was (5 278.87±31.68)cP.Conclusion 6% nano-silica is the best modifying material, and has the optimal effect of modification.
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<p><b>BACKGROUND</b>Currently, adhesive technique is popular in vascular repair but not widely used for defective vessels. This study aimed to determine the feasibility and effectiveness of repairing defective vessels with 2-octyl-cyanoacrylate and a homemade prosthetic component.</p><p><b>METHODS</b>Homemade prosthetic component consisting of expanded polytetrofluoroethylene (ePTFE), terylene film, and homemade soluble hollow stent mixed with adhesive can replace autologous graft and suture in repairing defective vessels, can fix vessels better using the stent without occlusive bleeding. Forty male mongrel dogs were used, 20 for biomechanical tests and 20 for animal experiments. In the biomechanical test, dogs were randomly divided into two groups (n = 10 each), one group repaired on the two sides of the carotid arteries with 2-octyl-cyanoacrylate and homemade component and another group repaired with suture and ePTFE. Of the 40 specimens, 10 were used for adhesive and 10 for suture specimens for tension strength test, whereas the remaining specimens were used for bursting pressure test. In animal experiments, dogs were also divided into adhesive and suture groups (n = 10), only of the left carotid artery. Recording the operational time, bleeding or not. Vessels were tested using color Doppler ultrasound, the inner diameter was measured, and the degree of stenosis at 8 weeks was evaluated digital subtraction angiography (DSA) were also performed. Specimens were then analyzed histologically.</p><p><b>RESULTS</b>In the adhesive and suture groups, the specimens could afford atension strength of (23.80 ± 1.51) N versus (24.60 ± 1.08) N (P > 0.05), the bursting pressure was (52.03 ± 2.43) kPa versus (50.04 ± 3.51) kPa (P > 0.05), and the mean time of anastomosis was (15.20 ± 0.55) minutes versus (25.97 ± 0.58) minutes (P < 0.05). One dog in the adhesive group was bleeding from the suture. One dog from each group presented with thrombosis at 1 week. After measuring using ultrasound, the stenosis degree of all dogs were no more than 30% except the two thromboses. DSA and histological observation showed no obvious difference between the two groups.</p><p><b>CONCLUSION</b>Defective vascular anastomosis with 2-octyl-cyanoacrylate and our homemade prosthetic component is feasible, effective, timesaving, and easy to master.</p>
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Animals , Dogs , Male , Anastomosis, Surgical , Methods , Carotid Arteries , General Surgery , Cyanoacrylates , Therapeutic Uses , Plastic Surgery Procedures , Methods , Vascular Surgical Procedures , MethodsABSTRACT
<p><b>BACKGROUND</b>Self and mutual-aiding occlusive dressing is a novel method to treat with the wounds in special circumstances. This study aims to prepare a new antimicrobial adhesive for the dressing and evaluate the application effects of the adhesive.</p><p><b>METHODS</b>The main component of the new antimicrobial adhesive was 5% triclosan / cyanoacrylate (CA) antimicrobial adhesive. The adhesive was modified with carboxylic multi-walled carbon nanotubes (MWCNTs-COOH), multi-walled carbon nanotubes (MWCNTs), hydrophobic nano-silica, nitrile rubber, epoxy resin and polymethyl methacrylate (PMMA) respectively. The bond strength, toughness and viscosity of the modified adhesive in different concentrations were examined to select the optimal modifying material and the best ratio to prepare the new antimicrobial adhesive according to the results. After that, the antimicrobial property of the new antimicrobial adhesive was tested by filter paper method. At last, we disposed the injury models in rats using the new antimicrobial adhesive to examine the application effects.</p><p><b>RESULTS</b>In individual tests, the bond strength modification performance of 0.064% MWCNTS-COOH is the best, the bond strength is (14.71 ± 1.48) Mpa. 8% nano-silica shows the best toughness modification performance, the Tg is (1.10 ± 0.24)°C. The viscosity modification performance of 8% nano-silica is the best, the viscosity is (15 536.68 ± 28.4) cP. However, consolidating three test results, 6% nano-silica/antimicrobial adhesive has the balanced bond strength, toughness and viscosity. Its bond strength is (14.03±1.92) Mpa, the Tg is (3.60 ± 0.68)°C, and the viscosity is (5 278.87 ± 31.68) cP. The inhibition zone diameter of 6% nano-silica/antimicrobial adhesive and antimicrobial adhesive group in Day 5 is (28.61 ± 0.91) mm versus (28.24 ± 2.69) mm (P > 0.05). In animal studies, both in blood routine test and pathological section, 6% nano-silica/antimicrobial adhesive group shows lower white blood cells count than gauze bandage group (P < 0.05).</p><p><b>CONCLUSIONS</b>6% nano-silica has the optimal effect of bond strength modification, toughness modification and viscosity modification, and the antimicrobial adhesive modified with it has a good antimicrobial property (resistant staphylococcus aureus).</p>
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Animals , Male , Rats , Anti-Bacterial Agents , Chemistry , Therapeutic Uses , Cyanoacrylates , Chemistry , Therapeutic Uses , Nanostructures , Chemistry , Therapeutic Uses , Occlusive Dressings , Rats, Sprague-Dawley , Triclosan , Chemistry , Therapeutic UsesABSTRACT
<p><b>OBJECTIVES</b>To investigate the prevalence of hepatitis B virus (HBV) genotypes and the association with hepatocellular carcinoma (HCC) or basal core promoter (BCP) mutation in Qidong, China.</p><p><b>METHODS</b>The whole genome of HBV or X gene sequences were obtained from serum samples of HBV infected patients by using PCR and direct sequencing methods. Phylogenetic tree was constructed to determine the genotypes or subgenotypes of HBV.</p><p><b>RESULTS</b>According to the phylogenetic tree constructed from full-length sequence of HBV, genotype C2 was predominant in Qidong area. It was prevalent in 44 out of the 48 cases (91.7%), whereas genotype B2 only existed in 4 cases (8.3%). No other genotypes or recombinant types were found in Qidong patients. The result of genotyping based on X gene sequence confirmed the above observation. In a total of 182 samples, 169 (92.9%) showed genotype C2 and 10 (5.5%) showed genotype B2. There were 3 (1.6%) patients showed a coinfection with C2 and B2. The infection rate of genotype C in Qidong was significantly higher than that in neighboring city Shanghai (chi(2) = 12.252, P less than 0.01). There was no significant difference of genotype distribution between HCC and chronic hepatitis groups (P is more than 0.05). The frequency of T1762/A1764 double mutation in genotype C2 (70.3%) was significantly higher than that in genotype B2 (30.8%, P less than 0.05). The other two types of point mutation which also occurred in BCP, i.e. T1766 and A1768, were only seen in genotype C2.</p><p><b>CONCLUSION</b>(1) Genotype C2 is the predominant genotype in Qidong, China. (2) There is no association between genotype C and HCC in Qidong. (3) Genotype C has a higher prevalence of BCP mutation than genotype B.</p>
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Adolescent , Adult , Aged , Child , Child, Preschool , Female , Humans , Male , Middle Aged , Young Adult , Carcinoma, Hepatocellular , Epidemiology , Virology , China , Epidemiology , DNA, Viral , Genetics , Genotype , Hepatitis B virus , Genetics , Hepatitis B, Chronic , Virology , Liver Neoplasms , Epidemiology , Virology , Mutation , Prevalence , Viral Core Proteins , GeneticsABSTRACT
<p><b>OBJECTIVE</b>A new kind of external fixator for orthopaedics is designed in order to overcome the shortcomings of high weight, hard to operate and high degree of hurt for the conventional external fixator.</p><p><b>METHODS</b>The quick casting method is used to realize fast shaping, and FEM (Finite Element Method) is used to verify the practicability of the design.</p><p><b>RESULTS</b>In order to verify the correctness of the design, FEM is used to simulate it. It is concluded from the simulated result that the biggest relative displacement between the borders of the separated bones is just 0.37 mm, which is much less than the requested value 1 mm. This fits the request to cure the patients whose bones are broken and shows the correctness of the design. Finally, ten sheep are used as specimen to verify the feasibility of the design. It is concluded from the X ray sketches of 2 weeks, 4 weeks and 8 weeks that there is no relative displacement happened between the border of the broken bone and the bone is well cured.</p><p><b>CONCLUSIONS</b>This kind of device is feasible to cure the broken bones and the design scheme can be used as the final treatment means.</p>
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Animals , Equipment Design , External Fixators , Fracture Fixation , SheepABSTRACT
This paper introduces the development on the research of measuring theory for orthopaedic biomechanics in detail. Then, the measuring method and corresponding measuring device are also mentioned. Advantages, disadvantages and development for the device are also introduced. Finally, the research prospect for it is introduced.
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Biomechanical Phenomena , Bone and Bones , Physiology , Physics , MethodsABSTRACT
Objective This paper is to study a new sutureless vascular bonding method. Methods New-Zealand rabbits were randomly assigned to one experimental group and one control group. 10 end-to-end bonding on rabbit femoral arteries (1.2mm vessel) were performed using the experimental technique with histoacryl glue (OB) and a central channel soluble stent. In the control group, 10 rabbit femoral arteries (1.2mm vessel) were anastomosed with the standard suture method. The patency rates and anastomotic time were recorded. The late anastomoses were evaluated with arteriograph and stoma tissue pathological section. Results The anastomosis mean time of the experimental group is 7.91 minutes and the one of the control group is 12.90 minutes. The immediate patency rates of two groups are both 100% and the late patency rates are 80% and 90% respectively. There are no haemorrhage when the clamp released and no distortion and stricture caused by sutures. Conclusion The sutureless vascular bonding method has no needs for suture needle and line, and thus the possible injuries during suture are reduced. The stent makes the vessel free from stoma stricture and binder invasion. The stoma leakage is also avoided through the adhensive. The enhanced suture speed results from the short clotting time and the hollow structure of the stent. With all the above-mentioned excellences, the method proves simple and efficient.
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In this paper, the solution modes of two stents with different structures are compared, and then one involved is elected as the optimum stent for anastomosis. Made of PEG20 000, two stents are solid and hollow respectively. The result proves that the hollow one, with the advantages of nonblocking bloodstream, undeflected and rapid solution, low requirement for raw materials, is fitter for anastomosis than the solid one.
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A stent for bloodvessel anastomosis, with a slippery, soft out layer and a rapidly soluble inner layer, is developed in this paper. The out layer is made up of the gelatin with a high purity and a low molecular weight, and the inner one of polyglycol with a molecular weight of 20000. The structure changes of the stent surface are studied with anastomosis environment simulated. The result proves that the stent can be applied to bloodvessel anastomosis