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Objective To determine the risk factors of postoperative nosocomial infections (NI) in patients of orthopedics department of a PLA hospital, in order to provide the theory basis for prevention and control of postoperative nosocomial infections in patients of orthopedics department. Methods Using the real-time nosocomial infection surveillance system, we selected and retrospectively reviewed the patients after orthopedics operation and the patients with postoperative NI from Jan. 2013 to Dec. 2015. A 1:1 matched case-control study was carried out. Controls were patients with the same period of hospitalization, the same department, the same sex and age difference of 5 years old, the same main diagnosis without NI. The data were analyzed using conditional logistic regression. Results In the survey of 13134 patients after orthopedics operation, there were 91 patients with postoperative NI and the infection rate was 0.69％. Multiple logistic regression analysis showed that who had admitted to the ICU (OR=103.128, 95％ CI: 1.470-7237.388) , with a high level of incision contamination (OR=24.097, 95％ CI: 1.428-406.725) , perioperative use of antimicrobial for prophylactic utilization (OR=12.534, 95％ CI:3.460-45.407) and using hormones before nosocomial infection (OR=6.872, 95％CI: 1.374-34.384) was a risk factor for postoperative NI. Conclusion The postoperative NI in patients of orthopedics department was at a low level, and patients who had admitted to the ICU, with a high level of incision contamination, irrational perioperative use of antimicrobial agents, using hormones before nosocomial infection will increase the incidence of postoperative NI.
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This experiment was aimed to discuss the protective effect and mechanism of total lignans from Tibetan medicinal Herpetospermum seeds on carbon tetrachloride (CCl4)-induced liver fibrosis in rats. Forty-eight male Sprague-Dawley rats were randomly divided into the blank control group (G1), model group (G2), total lignans high, middle and low dose groups (400,200, and 100 mg•kg⁻¹•d⁻¹)(G3/4/5) and the glycyrrhizin positive control group (25 mg•kg⁻¹•d⁻¹)(G6), n=8 in each group. The rats in blank group received normal feeding; the rats in model group, total lignans low, middle and high dose groups and glycyrrhizic group were subcutaneously in jected with 3 mL•kg⁻¹ olive oilsolution containing 40%CCl4 every two or three days for Eight weeks. During the course, the rats inblank group and model group were orally administered with 2 mL normal saline, and the rats in total lignans groups and the glycyrrhizin positive control group received corresponding doses of drugs by intragastric administration. Eight weeks later, after the the last time modeling, the rats were sacrificed. Then the biochemical analysis was used to determine alanine aminotransferase(ALT), aspartate aminotransferase(AST), and alkaline phosphatase (ALP) levels in serum while enzyme-linked immuno sorbent assay(ELISA) was applied for detecting transforming growth factor β1(TGF-β1), hyaluronic acid(HA), hydroxy-proline(HYP) and superoxide dismutase(SOD) levels in serum. HE and Masson's trichrome stainings were conducted in liver tissues to observe the pathological variations and grades of hepatic fibrosis. The results showed that as compared with the model group, the levels of ALT, AST, ALP, TGF-β1, HA, HYP and SOD in serum of total lignans groups were significantly decreased (P<0.05, P<0.01); levels of SOD in the liver tissue homogenate were increased(P<0.05, P<0.01); the pathological damage of the liver tissues were relieved (P<0.05, P<0.01), and liver fibrosis scores were decreased(P<0.05, P<0.01). The above experimentsindicated that total lignans from Tibetan medicinal Herpetospermum seeds can effectively reduce carbon tetrachloride-induced hepatic injury of rat liver fibrosis, reduce the degree of liver fibrosis, and its mechanism maybe associated with down-regulating TGF-β1 expression.
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Objective Objective To analyze the torque performance of lingual brackets with slots in different directions and the influence pattern of arch wires with different sizes and materials on torque of these lingual brackets.Methods The finite element models of the anterior maxilla lingual brackets with vertical and horizontal slot were constructed,using 3 kinds of materials (stainless steel,beta-titanium,nickel-titanium) and two sizes of arch wires (0.43 mm x 0.56 mm,0.41 mm x 0.56 mm),so as to compare and analyze their mechanical properties after the application of torque load on the left upper central incisors with a rotation angle of ±20°.Results With the increase in elastic modulus of the arch wire,torque moments of lingual brackets with horizontal and vertical slot both increased gradually.Torque performance of lingual brackets was affected more by the sizes and materials of arch wires than the directions of slots.The lingual bracket with vertical slot produced 1-2 times of torque force than that with horizontal slot under the same degree of torque angle.The effect of arch wire sizes was smaller than that of arch wire materials,while the synergistic change in sizes and materials of arch wires had the largest influence on torque performance of lingual brackets.Conclusions The torque performance of lingual bracket will be influenced with its different slot directions,the sizes and materials of arch wires.In clinical application,slot directions of lingual brackets as well as sizes and materials of arch wires should be adjusted properly according to the required torque force.
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Objective Objective To analyze the torque performance of lingual brackets with slots in different directions and the influence pattern of arch wires with different sizes and materials on torque of these lingual brackets.Methods The finite element models of the anterior maxilla lingual brackets with vertical and horizontal slot were constructed,using 3 kinds of materials (stainless steel,beta-titanium,nickel-titanium) and two sizes of arch wires (0.43 mm x 0.56 mm,0.41 mm x 0.56 mm),so as to compare and analyze their mechanical properties after the application of torque load on the left upper central incisors with a rotation angle of ±20°.Results With the increase in elastic modulus of the arch wire,torque moments of lingual brackets with horizontal and vertical slot both increased gradually.Torque performance of lingual brackets was affected more by the sizes and materials of arch wires than the directions of slots.The lingual bracket with vertical slot produced 1-2 times of torque force than that with horizontal slot under the same degree of torque angle.The effect of arch wire sizes was smaller than that of arch wire materials,while the synergistic change in sizes and materials of arch wires had the largest influence on torque performance of lingual brackets.Conclusions The torque performance of lingual bracket will be influenced with its different slot directions,the sizes and materials of arch wires.In clinical application,slot directions of lingual brackets as well as sizes and materials of arch wires should be adjusted properly according to the required torque force.
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Objective To analyze the torque performance of lingual brackets with slots in different directions and the influence pattern of arch wires with different sizes and materials on torque of these lingual brackets. Methods The finite element models of the anterior maxilla lingual brackets with vertical and horizontal slot were constructed, including three kinds of materials (stainless steel, beta-titanium, nickel-titanium) and two sizes of arch wires (0.43 mm×0.56 mm, 0.41 mm×0.56 mm), so as to compare and analyze their mechanical properties after the application of torque load on the left upper central incisors with a rotation angle of ±20°. Results With the increase in elastic modulus of the arch wire, torque moments of lingual brackets with horizontal and vertical slot both increased gradually. Torque performance of lingual brackets was affected more by the sizes and materials of arch wires than the directions of slots. The lingual bracket with vertical slot produced 1-2 times of torque force than that with horizontal slot under the same degree of torque angle. The effect of arch wire sizes was smaller than that of arch wire materials, while the synergistic change in sizes and materials of arch wires had the largest influence on torque performance of lingual brackets. Conclusion The lingual brackets with different slot directions, sizes and materials of arch wires will influence the torque performance of lingual brackets. In clinical application, slot directions of lingual brackets as well as sizes and materials of arch wires should be adjusted properly according to the required torque force.
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Objective To analyze the mechanical properties of V-bends with different materials, sizes of arch wires, angles, shapes, inter-bracket distances by using finite element method, so as to provide references for clinical practice of V-bends. Methods The finite element models of V-bends were established, including two kinds of materials (stainless steel, titanium-molybdenum alloy), two sizes（0.43 mm×0.64 mm, 0.48 mm×0.64 mm）, two V-bend positions, two angles(150°, 165°),and two inter-bracket distances（7,10 mm）, so as to compare and analyze their mechanical properties after simulative loading. Results The maximum force values produced by V-bends with stainless steel arch wire were greater than that of V-bends with β titanium steel arch wire. The force produced by V-bends with 0.43 mm×0.64 mm arch wire was smaller than that produced by V-bends with 0.48 mm×0.64 mm arch wire. The size of arch wire had a more obvious impact on V-bends with symmetrical arch wire. The force of V-bends with asymmetric arch wire was more evidently influenced by the change of inter-bracket distance. For V-bends with the same shape, the smaller the V-shaped angle, the greater the force on the bracket would be. Conclusions The V-bends with different materials, different sizes of arch wires, different shapes and inter-bracket distances will have different mechanical behaviors. In clinical application, the materials, sizes of arch wires, shapes and angles of V-bends should be adjusted properly according to the inter-bracket distances.