RESUMO
Soil fertility is vital for the growth of tea plants. The physicochemical properties of soil play a key role in the evaluation of soil fertility. Thus, realizing the rapid and accurate detection of soil physicochemical properties is of great significance for promoting the development of precision agriculture in tea plantations. In recent years, spectral data have become an important tool for the non-destructive testing of soil physicochemical properties. In this study, a support vector regression (SVR) model was constructed to model the hydrolyzed nitrogen, available potassium, and effective phosphorus in tea plantation soils of different grain sizes. Then, the successful projections algorithm (SPA) and least-angle regression (LAR) and bootstrapping soft shrinkage (BOSS) variable importance screening methods were used to optimize the variables in the soil physicochemical properties. The findings demonstrated that soil particle sizes of 0.25-0.5 mm produced the best predictions for all three physicochemical properties. After further using the dimensionality reduction approach, the LAR algorithm (R2C = 0.979, R2P = 0.976, RPD = 6.613) performed optimally in the prediction model for hydrolytic nitrogen at a soil particle size of 0.25~0.5. The models using data dimensionality reduction and those that used the BOSS method to estimate available potassium (R2C = 0.977, R2P = 0.981, RPD = 7.222) and effective phosphorus (R2C = 0.969, R2P = 0.964, RPD = 5.163) had the best accuracy. In order to offer a reference for the accurate detection of soil physicochemical properties in tea plantations, this study investigated the modeling effect of each physicochemical property under various soil particle sizes and integrated the regression model with various downscaling strategies.
Assuntos
Nitrogênio , Solo , Solo/química , Tamanho da Partícula , Nitrogênio/análise , Fósforo/análise , Potássio/análise , CháRESUMO
The purpose of this study is to develop a new polysaccharide-based hydrogel. The Box-Behnken design was used to optimize the optimal synthesis conditions of the hydrogel, with the swelling parameters as indicators. The findings of rheologic tests confirm that free radical polymerization and the introduction of linear polymers improved the mechanical strength of the hydrogel. Combined with the characterization results, the gel mechanism of BSP-g-PAA/PVA DN hydrogel was proposed. The intermolecular association and entanglement increase, which effectively dissipates energy, thereby enhancing the mechanical properties of the hydrogel. In vitro blood compatibility experiments show that DN hydrogel has a low hemolysis rate and a good coagulation effect. The material is non-cytotoxic to L929 cells. The hepatic haemorrhage and mouse-tail amputation models of rats and mice were used to further evaluate the in vivo wound sealing and hemostatic properties of the hydrogel. The blood loss and hemostatic time were significantly lower than those of the control group, indicating that the hydrogel has excellent hemostatic effects. Therefore, the obtained BSP-g-PAA/PVA DN network hydrogel has good comprehensive properties and is expected to be used as a hemostatic material or a precursor of a drug carrier and a tissue engineering scaffold.
Assuntos
Coagulação Sanguínea/efeitos dos fármacos , Hemostáticos/química , Hemostáticos/farmacologia , Hidrogéis/química , Hidrogéis/farmacologia , Orchidaceae/química , Polissacarídeos/química , Animais , Fenômenos Químicos , Técnicas de Química Sintética , Hemostáticos/síntese química , Hidrogéis/síntese química , Concentração de Íons de Hidrogênio , Masculino , Camundongos , Extratos Vegetais/química , Ratos , Reologia , Espectroscopia de Infravermelho com Transformada de Fourier , TermogravimetriaRESUMO
OBJECTIVE: To investigate the effects of Huangqi injection on the infection factors in children with acute lymphoblastic leukemia (ALL) during remission induction chemotherapy. METHODS: Ninety-one children with ALL were divided into treatment (n=47) and control groups (n=44) by a randomized double-blind method. During remission induction chemotherapy, the treatment group was given Huangqi injection (0.5 mL/kg·d) for 35 days, while an equal volume of normal saline was used instead in the control group; the other supportive care was the same for the two groups. After remission induction chemotherapy, the incidence of infection, duration of infection, white blood cell and neutrophil counts, site of infection, and positive rate of pathogenic bacteria in secretion were compared between the two groups. RESULTS: Four cases in the treatment group dropped out of the study due to allergic reaction. After remission induction chemotherapy, compared with the control group, the treatment group had a significantly lower incidence of infection (P<0.05), a shorter duration of infection at any site (P<0.05), a higher neutrophil count after chemotherapy (P<0.05), and lower incidence rates of respiratory tract infection, urinary tract infection, blood infection, and skin and soft tissue infections (P<0.05). Gram-negative bacteria were the main pathogens. Among the infected children, the positive rate of pathogenic bacteria in secretion was significantly lower in the treatment group than in the control group (P<0.05). CONCLUSIONS: Huangqi injection may reduce bone marrow suppression caused by chemotherapy drugs and increase neutrophil count during remission induction chemotherapy to reduce the incidence and duration of infection in children with ALL.