Search

Effects of trace TiB2 on solidification microstructure of Ti-6Al-4V alloy were investigated. The result shows that the microstructure of the ingot was refined by the added TiB2. The grain size and α lath size were reduced gradually with the increase in TiB2. The grain size is reduced by about an order of magnitude with an addition of 0·96 wt-%TiB2, and the dendrite appears in the ingot. Such a tendency is similar to the change of the microstructure with boron addition. Ti-6Al-4V-B phase diagram and growth restriction factor Q are applied to analyse the influence mechanism of trace TiB2 on the microstructure. [ABSTRACT FROM AUTHOR]

For the first stage, a metastable β titanium alloy, Ti-3.5Al-5Mo-4V-2Cr-2Sn-2Zr-1Fe reinforced with trace amounts of TiB whiskers and TiC particles was fabricated by vacuum arc melting process and hot forging followed by heat treatment at 780 °C/740 °C, then by aging at 500 °C, 550 °C, 570 °C and 600 °C. For the second stage, the unreinforced titanium alloy was also fabricated by the same process. The microstructural characteristics were investigated by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Traces of TiB whiskers and TiC particles (2.2 vol.%) with a volume ratio of 2:3 synthesized in situ exerted a hybrid reinforcing effect on the β titanium alloy. The reinforcements were uniformly distributed in the matrix and the elastic modulus was improved about 25 GPa. Ultimate tensile strength and yield strength achieves about 1625 MPa and 1500MPa respectively, with ductility at 7% when the aging temperature is 500 °C. The ductility of (TiB + TiC)/(Ti-3.5Al-5Mo-4 V-2Cr-2Sn-2Zr-1Fe) matrix composite could be enhanced by increasing the aging temperatures. After 780 °C followed by aging at 570 °C, excellent strength and plasticity properties were obtained (ultimate tensile strength of matrix alloy is 1350 MPa with elongation of 18% and ultimate tensile strength of composite is 1500 MPa with elongation of 13%). [ABSTRACT FROM AUTHOR]

Hot deformation behavior of high Nb containing TiAl based alloy with a nominal composition of Ti-44Al-8Nb-0.2W-0.2B-0.1Y at 1225 °C and 1275 °C is investigated. The deformation mechanism of α phase is dynamic recovery at 1275 °C, whereas γ phase is mainly dynamic recrystallized. It is revealed that α phase is softer and easier to be deformed when the alloy is deformed at 1275 °C. The reasons of the different deformation behavior between 1225 °C and 1275 °C, as well as the different deformation behavior between α phase and γ phase are analyzed. A multistep deformation process at gradually lowered temperature is proposed to eliminate the adverse influence of remnant lamellar structure on mechanical properties. [ABSTRACT FROM AUTHOR]

Objective: To explore the method of noninvasive hemodynamic monitoring system (NICaS) in monitoring the hemodynamics of patients with acute pesticide poisoning, and to analyze the clinical guiding value of NICaS in hemodynamics of patients with severe pesticide poisoning. Methods: In August 2019, 200 patients with severe acute organophosphorus pesticide poisoning (AOPP) or moderate severe acute paraquat pesticide poisoning (APP) admitted to Harrison international peace hospital from January 2017 to August 2019 were randomly divided into NICaS group ( n =68) , transpulmonary thermodilution method ( n =67) and empirical treatment group ( n =65) . The relationship between acute physiology and chronic health score (APACHE Ⅱ) , heart rate, hemodynamic indexes, survival rate and complications were analyzed. Results: There were no significant differences in age, sex ratio, body mass index, heart rate, systolic blood pressure, no treatment period and admission APACHE II score between NICaS group, Picco group and experience group ( P >0.05) ; Compared with the experience group, the mortality of AOPP and app in NICaS group and Picco group were lower, and the differences were statistically significant ( P <0.05) .The cardiac output (CO) had a significant correlation in the interval of 2.8-6.7 L·min(-1) ( r =0.738, r (2)=0.545, P <0.01) , and peripheral vascular resistance index (SVRI) had a significant correlation in the interval of 410-1 950 d·s·cm(-5)·m(2) ( r =0.792, r (2)=0.627, P <0.01) . Bland Altman analysis showed that CO and SVRI measured by Picco and NICaS had 97.01% and 95.52% consistency, respectively. Compared with the experience group, the average daily infusion volume and daily colloid infusion volume of NICaS group and Picco group were lower, the differences were statistically significant ( P <0.05) . Conclusion: NICaS can effectively monitor the hemodynamic indexes of patients with acute pesticide poisoning.

Objective: To assess the efficacy and safety of different opportunity of Saccharomyces boulardii (S. Boulardii ) Sachets combined with bismuth quadruple therapy for Helicobacter pylori( H. pylori )eradication. Methods: This experiment was a prospective study. A total of 300 H. pylori -infected patients were enrolled and randomized assigned into three groups. Quadruple therapy group received pantoprazole 40 mg+bismuth potassium citrate capsule 220 mg+amoxicillin 1 000 mg+furazolidone 100 mg, bid, oral for 14 days. The simultaneous probiotic group received pantoprazole 40 mg+bismuth potassium citrate capsule 220 mg+amoxicillin 1 000 mg+furazolidone 100 mg+ S. Boulardii Sachets 500 mg,bid,oral for 14 days.There after probiotic group: S.Boulardii Sachets was added on the first day after the end of 14 days in the quadruple group, for 500 mg, bid 14 days. The eradication rates and adverse reactions of the three groups were compared. Results: The eradication rates of H.pylori were 89.0%,90.4% and 91.3% in the quadruple therapy group, the simultaneous probiotic group and the there after probiotic group according to Per-protocol(PP) analysis,respectively,with no statistical difference ( P= 0.870). According to intention-to-treat(ITT)analysis, 81.0%, 85.0% and 84.0%, respectively, the difference was not statistically significant ( P= 0.732).The overall incidence of adverse reactions and the incidence of diarrhea and nausea in the simultaneous probiotic group, and the there after probiotic group were lower than those in the quadruple group( P< 0.05),and the difference was statistically significant.The overall incidence of adverse reactions and diarrhea in the simultaneous probiotic were lower than those in the there after probiotic group ( P= 0.021, P= 0.007), and the difference was statistically significant. Conclusions: S. Boulardii Sachets combined with quadruple therapy at the same time or after eradication treatment can not improve the H.pylori eradication rate,but can reduce the overall incidence of adverse reactions and the incidence of diarrhea and nausea. It is safer to add S. Boulardii Sachets at the same time than after eradication therapy.