【摘要】 目的 探讨低场磁共振弥散加权成像（DWI）诊断急性脑梗死的价值。 方法 2007年7月-2009年9月对48例脑梗死患者行常规MRI扫描和DWI，分析不同时期脑梗死的DWI表现。 结果 在发病的超急性期及急性期，DWI病灶显示率均为100.0%，T2WI病灶显示率分别为37.5%、73.7%、100.0%。 结论 低场DWI对急性脑梗死的诊断准确率高，明显优于常规MRI。【Abstract】 Objective To investigate the diagnostic value of diffusion weighted imaging (DWI) in acute cerebral infarction. Methods From July 2007 to September 2009, 48 patients with ischemic stroke underwent conventional MRI and DWI, and the characteristics of DWI were analyzed. Results Abnormal DWI signals were displayed in all patients at hyperacute stage or acute stage, abnormal T2WI signals existed in 37.5%, 73.7%, and 100.0%, respectively. Conclusion DWI in low field MR is highly accurate in diagnosing acute cerebral infarction, which is superior to conventional MRI.
This study aims to overcome the shortcomings such as low efficiency, high cost and difficult to carry out multi-parameter research, which limited the optimization of infusion bag configuration and manufacture technique by experiment method. We put forward a fluid cavity based finite element method, and it could be used to simulate the stress distribution and deformation process of infusion bag under external load. In this paper, numerical models of infusion bag with different sizes was built, and the fluid-solid coupling deformation process was calculated using the fluid cavity method in software ABAQUS subject to the same boundary conditions with the burst test. The peeling strength which was obtained from the peeling adhesion test was used as failure criterion. The calculated resultant force which makes the computed peeling stress reach the peeling strength was compared with experiment data, and the stress distribution was analyzed compared with the rupture process of burst test. The results showed that considering the errors caused by the difference of weak welding and eccentric load, the flow cavity based finite element method can accurately model the stress distribution and deformation process of infusion bag. It could be useful for the optimization of multi chamber infusion bag configuration and manufacture technique, leading to cost reduction and study efficiency improvement.
This study explored the variation of bursting force of multi-chamber infusion bag with different geometry size, providing guidance for its optimal design. Models of single-chamber infusion bag with different size were established. The finite element based on fluid cavity method was adopted to calculate the fluid-solid coupling deformation process of infusion bag to obtain corresponding critical bursting force. As a result, we proposed an empirical formula predicting the critical bursting force of one chamber infusion bag with specified geometry size. Besides, a theoretical analysis, which determines the force condition of three chamber infusion bag when falling from high altitude, was conducted. The proportion of force loaded on different chamber was gained. The results indicated that critical bursting force is positively related to the length and width of the chamber, and negatively related to the height of the chamber. While the infusion bag falling, the impact force loaded on each chamber is proportional to the total liquid within it. To raise the critical bursting force of in fusion bag, a greater length and width corresponding to reduced height are recommended considering the volume of liquid needed to be filled in.
ObjectivesTo investigate the efficacy and safety of Hou Gu Mi Xi (HGMX) in patients with nonorganic gastrointestinal disorders (NOGD) from the aspect of dietary therapy.MethodsA randomized, double-blind, parallel, placebo-controlled trial was performed. Patients with NOGD and spleen qi deficiency (SQD) syndrome were randomly assigned into HGMX or placebo group. Each received 30 g/day HGMX or placebo for one year. The outcomes included SQD scores, body weight, body mass index (BMI), gastrin-17, and adverse events (AEs) between HGMX and placebo groups, or subgroups divided by NOGD type or helicobacter pylori (Hp) infection, at the 0th, 2nd, 4th, 8th, 26th, or 52nd weeks’ follow-up.ResultsThe reduction of SQD scale score was found in the HGMX group compared with the placebo group at 4th week (MD=−9.40, 95%CI −18.53 to −0.27, P=0.044), 8th week (MD=−10.07, 95%CI −19.66 to −0.48, P=0.04), 26th week (MD=−12.45, 95%CI −22.31 to −2.59, P=0.014) and 52th week (MD=−17.25, 95%CI −28.53 to −5.97, P=0.003), respectively. In the subgroup analyses, HGMX showed significant efficacy in Hp-negative patients with the detailed reduction of SQD scale score being (MD=−15.20, 95%CI −28.16 to −2.24, P=0.022), (MD=−17.91, 95%CI −31.22 to −4.59, P=0.009) and (MD=−20.38, 95%CI −35.43 to −5.32, P=0.008) at the 8th, 26th and 52nd week, respectively, and in patients with chronic nonatrophic gastritis with the detailed reduction being (MD=−13.02, 95%CI −24.75 to −1.29, P=0.03), (MD=−12.43, 95%CI −24.36 to −0.5, P=0.041) and (MD=−15.90, 95%CI −30.72 to −1.08, P=0.036) at the 2nd, 26th and 52nd week, respectively, and in patients with functional gastrointestinal disease with the reduction being (MD=−18.22, 95%CI −35.75 to −0.69, P=0.042) at the 52nd week. However, no significant efficacy was found in Hp-positive patient at any time. HGMX was not associated with changes in weight, BMI, or gastrin-17. No AEs were reported in the HGMX group.ConclusionsHGMX improves SQD symptoms in patients with NOGD, especially Hp-negative patients, and has a good safety profile.