RESUMEN
Methyl acetate (MA) has a wide range of applications as an important industrial chemical. Traditional MOR zeolite for carbonylation of DME to MA accumulated carbon easily because of a 12-membered ring (12 MR) channel. In this work, we innovatively developed the method of recrystallization ferrierite (FER) zeolite using special chelating ligand sodium oleate which can affect ions other than alkali metals. The characterization results of N2 adsorption, transmission electron microscopy (TEM), and Fourier transform infrared spectroscopy (FT-IR) show that hydrothermal recrystallization of ferrierite using sodium oleate resulted in a higher Si/Al ratio, a bigger specific surface area and a larger number of Brønsted acid sites in the eight MR channels, which was more efficient in the reaction of carbonylation of dimethyl ether than ordinary alkali treatment.
Asunto(s)
Éteres Metílicos , Zeolitas , Zeolitas/química , Espectroscopía Infrarroja por Transformada de FourierRESUMEN
OBJECTIVE: To investigate postoperatively repairing methods and their clinical effects of the olders over 80 years old with head and facial skin malignancies. METHOD: Eighteen cases of skin cancers in the head and face, whose malignancies were resected with Mohs microscopic surgery, according to the local or systemic condition of patients after surgery we choose different repairing methods: free skin flap grafting in 2 cases, local skin flap transferring 12 cases; including rotation skin flap grafting 6 cases, sliding flap 4 cases, nasolabial flap 2 cases; transposition flap 4 cases. RESULT: Operations of the 18 cases went well without special complications. All of the flaps were alive with partial flap necrosis in 1 case, which was cured 1 month later by dressing changes. During the follow-up period ranged from 6 months to 2 years,no tumor recurred,the functional recovery and appearance were satisfactory. CONCLUSION: Choosing operating methods in head and facial skin malignancies should consider patients' age, disease state and general condition. Reparing methods of Head and facial skin malignancies in the advanced ages should be selected according to their specific circumstances, especially the simple, convenient and rapid with less trauma way.
Asunto(s)
Procedimientos de Cirugía Plástica , Neoplasias Cutáneas/cirugía , Trasplante de Piel , Cara/patología , Colgajos Tisulares Libres , Cabeza/patología , Humanos , Recurrencia Local de Neoplasia , Periodo Posoperatorio , Piel/patologíaRESUMEN
Well-defined ceria nanocubes covered by oleic acid with exposed {100} facets have been synthesized and exhibited exclusive selectivity for the oxidation of toluene to benzaldehydes in liquid phase by O(2).
RESUMEN
High quality noncrystalline NiPB nanotubes were synthesized and exhibited high efficiency for the catalytic hydrogenation of p-chloronitrobenzene due to the characteristic confinement effect of the nanotubes.
Asunto(s)
Nanopartículas del Metal/química , Nanotubos/química , Níquel/química , Nitrobencenos/química , Catálisis , Hidrogenación , Nanopartículas del Metal/ultraestructura , Nanotubos/ultraestructuraRESUMEN
BACKGROUND: In Inner Mongolia, China, more than 300,000 people are chronically exposed to arsenic via their drinking water. We have previously reported that the prevalence of arsenical dermatosis was as high as 40% in the Hetao Plain area. However, the association between exposure to arsenic in drinking water and adverse health effects has not been fully examined. The purpose of this study was to examine the association between exposure to arsenic and prevalence of subjective symptoms. METHODS: A cross-sectional study was carried out in 431 residents of an arsenic-affected village and 189 residents of an arsenic-free village in 1996. Health-related interviews and physical examinations were conducted. The odds ratio for each subjective symptom was estimated, comparing residents of arsenic-free and affected villages. RESULTS: An arsenic level of 50+ microg/L was found in 90.6% of wells in the arsenic-affected village. Adjusted odds ratios of subjective symptoms, including coughs (odds ratio [OR] = 12.8, 95% confidence interval [CI]: 6.4-25.6), stomachaches (OR = 5.8, 95% CI: 3.6-9.4), palpitations (OR = 3.6, 95% CI: 1.5-8.2), urination problems (OR = 14.7, 95% CI: 3.3-65.5) and spontaneous abortions (OR = 2.7, 95% CI: 0.8-8.4), were markedly higher amongst residents of the arsenic-affected village, including those without arsenic dermatosis. CONCLUSIONS: The present study shows a high prevalence of subjective symptoms amongst residents of an arsenic-affected village. Symptoms occurred in people with and without arsenic dermatosis. Our findings suggest that symptoms other than dermatosis should be considered when a clinical diagnosis of arsenic toxicosis is made.