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In situ synthesis technology was adopted to fabricate SiC reinforced Ti3SiC2 composite by displacement reaction of Si and TiC powders. The formation of SiC particles as reinforcements with elongated or equiaxed shape distributed in Ti3SiC2 matrix. The average size of SiC equiaxed particles was about 2 μm and that of elongated ones was in the range of 5–8 μm in length and 2 μm in width. TiC with about 1 μm in size was also found in the composite. The particles of SiC or TiC inhibited the grain-boundary migration of Ti3SiC2 resulting in a fine Ti3SiC2 matrix with a grain size of 10 μm. Differential scanning calorimetry showed that Si reacted drastically with TiC at 1340 °C with release of heat. The presence of TiC in the Ti3SiC2/SiC composite should be attributed to decomposition of Ti3SiC2 at 1500 °C rather than the loss of Si during reaction process that resulted in unreacted TiC left. Reaction paths in the present experiment were postulated on the basis of Ti–Si–C system and reaction model of Mo2C–Si to understand the mechanism of the formation of Ti3SiC2 and SiC. [Copyright &y& Elsevier]

Ti3SiC2/SiC composite has been synthesized by in situ displacement reaction of Si and TiC powders. Its relative density is >98%. Its Vickers hardness was measured to be 8.7 GPa. Its flexural strength and the fracture toughness were 505 MPa and 5.3 MPa·m1/2, respectively. Scanning electron micrograph (SEM) and transmission electron micrograph (TEM) were used to observe the microstructure of the composite. Mechanisms for its high flexural strength and fracture toughness were discussed, respectively. The composite shows a better oxidation resistance than monolithic Ti3SiC2 at high temperatures. The oxidation layers were comprised of an outer layer with coarse TiO2 grains and an inner layer with a mixture of fine-grained SiO2 and TiO2. Its weight gain is only about 7.9 mg/cm2 at 1200 °C in air for 21 h. However, that of Ti3SiC2 is 30 mg/cm2. The results suggested that the in situ formation of SiC improved its oxidation resistance. [Copyright &y& Elsevier]

The oxidation behavior of Ti3SiC2 with additive-Al2O3 was studied over the temperature range of 1000–1500 °C in air. Ti3SiC2 based composite has a good oxidation resistance at below 1100 °C. The oxidation kinetics followed a parabolic and a linear law respectively at different oxidation stages. Morphology of oxidation products was observed from the oxidized surface by scanning electron microscope (SEM). Oxides were identified by X-ray diffraction (XRD) and energy-dispersive spectroscopy (EDS). The existence of additive-Al2O3 influenced the morphology of oxides and the oxidation behavior of Ti3SiC2. The formation of pores or cavities at high temperature provided the channels for diffusion of oxygen and accelerated the oxidation behavior of Ti3SiC2 based composite. The effects related to the morphology and microstructure features on the oxidation kinetics are discussed. [Copyright &y& Elsevier]

Aim: To characterize the correlation between severity of hepatopulmonary syndrome (HPS) and degree of hepatic dysfunction, and to explore how intestinal endotoxemia (IETM) affects the development of HPS in cirrhotic rats., Methods: Male Wister rats were fed with a diet containing maize flour, lard, cholesterol, and alcohol and injected subcutaneously with CCl(4) oil solution every two days for 8 wk to induce typical cirrhosis and development of HPS. The animals were also given a nitric oxide (NO) production inhibitor, N(omega)-nitro-L-arginine methyl ester (L-NAME) intraperitoneally, and an iNOS inhibitor, aminoguanidine hydrochloride (AG) via gavage daily from the end of the 4th wk to the end of the 6th or 8th wk, or a HO-1 inhibitor, zinc protoporphyrin (ZnPP) intraperitoneally 12 h prior to killing. Blood, liver and lung tissues were sampled., Results: Histological deterioration of the lung paralleled to that of the liver in the cirrhotic rats. The number of pulmonary capillaries was progressively increased from 6.1 +/- 1.1 (count/filed) at the 4th wk to 14.5 +/- 2.4 (count/filed) at the 8th wk in the cirrhotic rats. Increased pulmonary capillaries were associated with increased blood levels of lipopolysaccharide (LPS) (0.31 +/- 0.08 EU/mL vs control 0.09 +/- 0.03 EU/mL), alanine transferase (ALT, 219.1 +/- 17.4 U/L vs control 5.9 +/- 2.2 U/L) and portal vein pressure. Compared with normal control animals, the number of total cells in bronchoalveolar lavage fluid (BALF) of the cirrhotic rats at the 8th wk was not changed, but the number of macrophages and the ratio of macrophages to total cells were increased by nearly 2-fold, protein expression of inducible nitric oxide synthase (iNOS) and endothelial nitric oxide synthase (eNOS) started to increase significantly at the 4th wk, and reached its peak at the 8th wk in the lung of cirrhotic rats. The increase of iNOS expression appeared to be quicker than that of eNOS. NO(2)(-)/NO(3)(-) was also increased, which was correlated to the increase of iNOS (r = 0.7699, P < 0.0001) and eNOS (r = 0.5829, P < 0.002). mRNA expression of eNOS and iNOS was highly consistent with their protein expression., Conclusion: Progression and severity of HPS as indicated by both increased pulmonary capillaries and histological changes are closely associated with LPS levels and progression of hepatic dysfunction as indicated by increased levels of ALT and portal vein pressure. Intestinal endotoxemia plays a central role in the development of HPS in the cirrhotic rat model by inducing NO and/or CO.

To analyze the prognosis and risk factors of acute nonlymphocytic leukemia (ANLL), 94 patients with acute nonlymphocytic leukemia were enrolled in this study, while survival rate and risk factors of prognosis were analyzed. The results indicated that the complete remission (CR) ratio was 51.1%. Overall survival and event-free survival rates of month 6, 12, 18, 24 were 68.6%, 55.8%, 53.8%, 46.4%, 21.3% and 57.9%, 38.6%, 33.3%, 31.6%, 0% respectively. The factors such as age<40 years, WBC<10.0x10(9)/L before chemotherapy, WBC in the period of bone marrow suppression<1.0x10(9)/L, chemotherapy within 1 month after occurrence of leukemia, blood transfusion before chemotherapy of APL had favourable influence on remission and survival rates of ANLL patients. CR1, the time to get CR, length of CR and relapse significantly correlated with prognosis (p<0.05). It is concluded that the individualized therapy concerning the risk factors should be applied to ANLL patients for improving the remission, survival rate and prognosis.

In order to analyze the prognosis and related factors of acute lymphoblastic leukemia (ALL), 53 newly diagnosed ALL patients were enrolled in this study. The therapeutic efficacy and prognosis of 53 cases of ALL were analyzed, the remission, relapse, overall survival and event-free survival were studied, and relation between different factors and prognosis of ALL were investigated by comparison of cases in same stage. The results showed that the complete remission was achieved in 36 out of 53 patients, the total remission rate was 67.9%, the total relapse rate was 37.7%, the median relapse duration was 6 months after remission. Median overall survival (OS) and median event-free survival (EFS) time were 4 and 1 months after remission respectively, OS and EFS rate of 18 month was 35.1% and 14.2%. The patients with different gender had significantly different EFS. Age was an independent risk factor of CR rate. White blood cell count and hemoglobin level of newly diagnosed patients were significantly correlated with OS and EFS. Absolute neutrophil count (ANC) at the end of the induction chemotherapy was an independent related factor of OS, the higher ANC, the lower risk of death. The patients with or without chemotherapy related infection had different relapse rate. The patients with bleeding after chemotherapy had lower OS when compared with those without bleeding. Serum glucose level was a significant negative prognostic factor. It is concluded that there is higher relapse rate, poor prognosis in adult ALL in comparison with children. In order to decrease the relapse rate and prolong the EFS, individual therapeutical regimens and prophylaxis of complicating diseases should be applied to ALL patients.