RESUMEN
To explore the effects of different concentrations of zinc ï¼Znï¼ on the growth and root architecture classification of maize seedlings under cadmium ï¼Cdï¼ stressï¼ a hydroponic experiment was conducted to study the effects of different concentrations of Zn ï¼0ï¼ 10ï¼ 25ï¼ 50ï¼ 100ï¼ 200ï¼ and 400 µmol·L-1ï¼ on the growthï¼ root architecture and classification characteristicsï¼ Cd contentï¼ root Cd uptake capacityï¼ and photosynthetic system of maize seedlings under Cd stress ï¼50 µmol·L-1ï¼ by using Zhengdan 958 as the experimental material. Principal component analysis and the membership function method were used for comprehensive evaluation. The results showed that the 50 µmol·L-1 Cd stress had a significant toxic effect on maize seedlingsï¼ which significantly reduced chlorophyll content and photosynthetic parameters. The main root lengthï¼ plant heightï¼ biomassï¼ root forksï¼ and root tipsï¼ including the root length and root surface area of the grade â -â ¢ diameter range and the root volume of the grade â -â ¡ diameter rangeï¼ decreased significantlyï¼ which hindered the normal growth and development of maize seedlings. Compared with that under no Zn applicationï¼ 100 µmol·L-1 and 200 µmol·L-1 Zn application reduced the uptake of Cd by maize seedlingsï¼ significantly reduced the Cd content in shoots and roots and the Cd uptake efficiency. The toxic effect on maize seedlings was alleviatedï¼ and the fresh weightï¼ dry weightï¼ tolerance indexï¼ and root forks of shoots and roots were significantly increased. The photosynthesis of maize seedlings was significantly enhancedï¼ and the photosynthetic rate and the total chlorophyll content was significantly increased. The RLï¼ SAï¼ and RV in the â -â ¡ diameter range reached the maximum at 100 µmol·L-1 Znï¼ and the RLï¼ SAï¼ and RV in the â ¢ diameter range reached the maximum at 200 µmol·L-1 Znï¼ which were significantly higher than those without Zn treatment. The comprehensive evaluation of the growth tolerance of maize seedlings showed that 100 µmol·L-1 and 200 µmol·L-1 Zn had better effects on alleviating Cd toxicity. Comprehensive analysis showed that the application of appropriate concentration of Zn could reduce the Cd content in maize seedlingsï¼ the Cd uptake capacityï¼ and Cd uptake efficiency of rootsï¼ increase the biomass accumulation of maize seedlingsï¼ reduce the effect of Cd toxicity on root architectureï¼ reduce the effect on the light and systemï¼ and improve the tolerance of maize seedlings to Cd.
Asunto(s)
Plantones , Contaminantes del Suelo , Zinc , Cadmio , Zea mays , Raíces de Plantas , ClorofilaRESUMEN
A study was carried out to retrieve optical thickness and cloud top height of cirrus clouds from the Atmospheric Infrared Sounder (AIRS) high spectral resolution data in 1070~1135 cm-1 IR band using a Combined Atmospheric Radiative Transfer model (CART) by brightness temperature difference between model simulation and AIRS observation. The research is based on AIRS LIB high spectral infrared observation data combined with Moderate Resolution Imaging Spectroradiometer (MODIS) cloud product data. Brightness temperature spectra based, on the retrieved cirrus optical thickness and cloud top height were simulated and compared with brightness temperature spectra of AIRS observation in the 650~1150 cm-1 band. The cirrus optical thickness and cloud top height retrieved were compared with brightness temperature of AIRS for channel 760 (900.56 cm-1, 11. 1 µm) and cirrus reflectance of MODIS cloud product. And cloud top height retrieved was compared with cloud top height from MODIS. Results show that the brightness temperature spectra simulated were basically consistent with AIRS observation under the condition of retrieval in the 650~1150 cm-1 band. It means that CART can be used to simulate AIRS brightness temperature spectra. The retrieved cirrus parameters are consistent with brightness temperature of AIRS for channel 11. 1 µm with low brightness temperature corresponding to large cirrus optical thickness and high cloud top height. And the retrieved cirrus parameters are consistent with cirrus reflectance of MODIS cloud product with high cirrus reflectance corresponding to large cirrus optical thickness and high cloud top height. Correlation coefficient of brightness temperature between retrieved cloud top height and MODIS cloud top height was relatively high. They are mostly located in the range of 8. 5~11.5 km, and their probability distribution trend is approximately identical. CART model is feasible to retrieve cirrus properties, and the retrieval is reliable.
RESUMEN
OBJECTIVE: To study the nosocomial fungal infections in the patient with severe hepatitis and analyze of risk factor. METHODS: All 115 severe hepatitis with fungal infections inpatients was studied prospectively. RESULTS: We identified 115 cases with fungal infections, the mean age of patients was 37.2+/-21.5 years, male: 49 cases, female 66 cases. Infection of abdominal cavity accounted for 40.9%, infectious rate in respiratory tract and digestive tract were 26.9%, 21.8%, respectively. Candida albicans accounted for 67.6%. Use of broad-spectrum antibiotic and corticosteroids, neutropenia, severity of liver disease, improper medical manipulations as significant risk factors for fungal infection. Death rate of study group and control group was 59.1%, 34.8%, respectively (x2=36.0). In multivariate analysis, neutropenia, disseminated infection and severity of liver diseases were independent prognostic factors. CONCLUSION: Identification of risk factors and predictors of a poor outcome in patients with severe hepatitis with fungal infections, it suggested that implications in prophylaxis of fungal infection, early diagnosis and appropriate therapy would be important for these patients.