RESUMEN
A two-year (2009-2011) field experiment was conducted to study the effects of different tillage modes, straw-returning, and their interactions on the soil total organic carbon (TOC) and labile organic carbon (LOC) components (easily oxidizable organic carbon (EOC), water-soluble organic carbon (WSOC), and microbial biomass carbon (MBC)) at the soil depths of 0-7, 7-14, and 14-21 cm in a farmland with rice-wheat double cropping. In all treatments of straw-returning, the TOC and LOC contents in each soil layer were significantly higher than those without straw-returning. Under plowing tillage, the MBC content in 0-7 cm soil layer was significantly higher than that under rotary tillage, but the EOC content was in adverse. Rotary tillage made the TOC content in 7 - 14 cm soil layer being significantly higher, as compared with plowing tillage. The TOC, WSOC, and MBC contents in 14-21 cm soil layer under plowing tillage were significantly higher than those under rotary tillage. Plowing tillage combined with rice and wheat straws-returning made the soil TOC content being higher than the other treatments.
Asunto(s)
Agricultura/métodos , Carbono/química , Oryza/crecimiento & desarrollo , Tallos de la Planta/química , Suelo/química , Triticum/crecimiento & desarrollo , Carbono/análisis , China , Ecosistema , Compuestos Orgánicos/análisis , Oryza/química , Eliminación de Residuos/métodosRESUMEN
Based on the organic carbon data of 222 topsoil samples taken from 38 paddy field experiment sites in South China, calculations were made on the relative annual change of topsoil organic carbon content (RAC) and carbon sequestration duration in the paddy fields in South China under five fertilization modes (inorganic nitrogen fertilization, N; inorganic nitrogen and phosphorus fertilization, NP; inorganic nitrogen, phosphorus, and potassium fertilization, NPK; organic fertilization, O; and inorganic plus organic fertilization, OF). The RAC under the fertilizations was 0-0.4 g x kg(-1) x a(-1), with an increment of 0.20 and 0.26 g x kg(-1) x a(-1) in double and triple cropping systems, respectively. The RAC was higher in treatments O and OF than in treatments N, NP, and NPK, being the highest (0.32 g x kg(-1) x a(-1)) in treatment OF. The topsoil organic carbon accumulation rate decreased with increasing time, and the carbon sequestration duration in treatments N, NP, NPK, O, and OF was about 22, 28, 38, 57, and 54 years, respectively. Inorganic plus organic fertilization was the most effective practice for soil carbon sequestration in the paddy fields in South China.
Asunto(s)
Secuestro de Carbono , Carbono/análisis , Fertilizantes , Oryza/crecimiento & desarrollo , Suelo/análisis , China , Compuestos Inorgánicos/metabolismo , Nitrógeno/metabolismo , Compuestos Orgánicos/análisis , Compuestos Orgánicos/metabolismo , Factores de TiempoRESUMEN
Based on the 'three critical points' theory of eco-fitness, and by using dynamic weighting and fitting methods, an assessment system for the eco-fitness of county-level agricultural leading industry structure was constructed, and, taking Zhangqiu of Shandong Province, East China as a case, the eco-fitness of county-level agricultural leading industry structure was assessed and predicted. Due to the limited agro-ecological resources, the comprehensive eco-fitness index of four kinds of agricultural leading industry in Zhangqiu presented an upward trend from 2005 to 2010, but a downward trend from 2011 to 2015. The eco-fitness indices of oil crops and fruits would be negative in 2015. The applied research in Zhangqiu confirmed the validity of the assessment system constructed for the eco-fitness of county-level agriculture leading industry structure and the rationality of the prediction model.
Asunto(s)
Agricultura , Conservación de los Recursos Naturales , Ecosistema , China , Ecología , Modelos TeóricosRESUMEN
The present study aimed to explore whether the stretch of ischemic myocardium could modulate the electrophysiological characteristics via mechanoelectric feedback (MEF), as well as the effect of phalloidin on the electrophysiological changes. Thirty-two Wistar rats were randomly divided into 4 groups: control group (n=9), phalloidin group (n=7), myocardial infarction (MI) group (n=9), MI + phalloidin group (n=7). The acute myocardial infarction (AMI) was conducted by ligation of the left anterior descending (LAD) coronary artery for 30 min in isolated rat heart. The volume alternation of a water-filled latex balloon in the left ventricle produced the stretch of myocardium. After perfused on Langendorff, the isolated hearts were stretched for 5 s by an inflation of 0.1, 0.2 and 0.3 mL separately and the effect of stretch was observed for 30 s, including the left ventricular systolic pressure (LVSP), left ventricular end-diastolic pressure (LVEDP), ±dp/dt(max), monophasic action potential duration at 90% repolarization (MAPD90), and occurrence of premature ventricular beats (PVB) and ventricular tachycardia (VT). The stretch caused an increase of MAPD(90) in both control and MI rats (P<0.05, P<0.01). Moreover, MAPD(90) in MI group increased more significantly than that in the control group at the same degree of stretch (P<0.05, P<0.01). Phalloidin (1 µmol/L) had no effect on MAPD(90) in basal state. After stretch, MAPD(90) in phalloidin group slightly increased but was not significantly different from that in the control group. However, phalloidin reduced MAPD(90) in infarcted myocardium, especially when ΔV=0.3 mL (P<0.05). The incidence rates of PVB and VT in MI group were higher than that in the control group (both P<0.01). And there was no significant difference in the incidence rates of PVB and VT between phalloidin group and control group. Phalloidin inhibited the occurrence of PVB and VT in infarcted hearts (both P<0.01). LVSP and +dp/dt(max) in MI group obviously decreased (P<0.01 vs control). With application of phalloidin, LVSP slightly, but not significantly increased in infarcted hearts, while -dp/dt(max) significantly increased (P<0.05). It is suggested that MI facilitates the generation and maintenance of malignant arrhythmias, while phalloidin obviously inhibits the occurrence of arrhythmias.
Asunto(s)
Potenciales de Acción , Corazón/fisiopatología , Infarto del Miocardio/fisiopatología , Faloidina/farmacología , Animales , Arritmias Cardíacas/prevención & control , Vasos Coronarios , Corazón/efectos de los fármacos , Ventrículos Cardíacos , Ratas , Ratas WistarRESUMEN
OBJECTIVE: To study the therapeutic effect of traditional Chinese herbal medicinal preparation Tangshenqing (TSQ) combined with alprostadil in the treatment of early- and intermediate-stage diabetic nephropathy (DN). METHODS: One hundred and twenty DN patients were randomized into 3 groups for different treatment protocols. The patients in the control group were given the basic treatment (low-protein diabetic diet and rigorous control of blood glucose, blood pressure, and blood fatty acid), and those in treatment group A received TSQ (containing Astragalus membranaceus, Panax notoginseng, Epimedium brevicornum, etc) in addition to the basic treatment, and those in treatment group B were treated with alprostadil injections (for 14 consecutive days) in addition to the treatment given in group A. Therapeutic effect evaluation was carried out after a 30-day treatment in all the patients. RESULTS: The overall efficaey rate of the treatment was 78.37% in the control group, 88.57% in the treatment group A, and 94.44% in treatment group B, suggesting better therapeutic effect in the latter two groups than in the control group (P<0.05). Patients in all the 3 groups exhibited symptomatic improvement of various degrees, but the treatment group B had the best results. After the treatments, the patients' blood glucose and fatty acids were lowered, without obvious difference between the 3 groups. Compared with the control group, the patients in the two treatment groups showed significant reduction in fibrinogen, 24-h urine microprotein and urine protein after the treatment (P<0.01 or 0.05). CONCLUSION: Combined use of traditional Chinese herbal medicine TSQ and alprostadil injections produces definite therapeutic effect on early- to intermediate-stage DN.
Asunto(s)
Nefropatías Diabéticas/terapia , Medicina Integrativa/métodos , Medicina Tradicional China/métodos , Anciano , Albuminuria/metabolismo , Glucemia/metabolismo , Nefropatías Diabéticas/tratamiento farmacológico , Nefropatías Diabéticas/metabolismo , Nefropatías Diabéticas/fisiopatología , Femenino , Fibrinógeno/metabolismo , Humanos , Riñón/efectos de los fármacos , Riñón/fisiopatología , Masculino , Persona de Mediana Edad , Factores de Tiempo , Resultado del TratamientoRESUMEN
AIMS: To explore whether the stretch of ischaemic myocardium could modulate the electrophysiological characteristics, especially repolarization via mechanoelectric feedback (MEF), as well as the effect of streptomycin (SM) on these changes. Methods Thirty-six wistar rats were randomly divided into four groups: control group (n = 9), SM group (n = 9), myocardial infarction (MI) group (n = 9), and MI + SM group (n = 9). After perfused on Langendorff, the isolated hearts were stretched for 5s by a ballon inflation of 0.2mL. After being stretched, the effect of the stretch was observed for 30s, including the 20, 20-70, 70, and 90% monophasic action potential duration (MAPD), i.e. MAPD(20), MAPD(20-70), MAPD(70), and MAPD(90), respectively, premature ventricular beats (PVB), and ventricular tachycardia (VT). Results The stretch caused a decrease in MAPD(20-70) (both P <0.01) and an increase in MAPD(90) (both P <0.01) in both control and MI groups. Moreover, the MAPD(90) in the MI group had increased more significantly than that in the control group (P <0.05). A concentration of 200 micromol/L of SM had no influence on both MAPD(20-70) and MAPD(90) of basic state (P > 0.05, except MAPD(20-70) between the control and SM groups, P < 0.01), whereas it had reduced the length of MAPD(90) (P < 0.05) and inhibited the decrease in MAPD(20-70) induced by the inflation. There was a decrease in the tendency of MAPD(70) after the stretch (P = NS) and SM had reversed the tendency, whereas MAPD(20) had no obvious changes after inflation. The incidence rate of PVB and VT in the MI group was higher than that in the control group after inflation (P < 0.01). The 200 micromol/L SM reduced the incidence rate of PVB, and obviously inhibited the occurrence of VT (P < 0.01). CONCLUSIONS: Stretch could alter the electrophysiological activities of myocardium via MEF, which could enhance in acute myocardial infarction and facilitate the generation and maintenance of malignant arrhythmias. SM could significantly inhibit the occurrence of arrhythmias, which may correlate with the effect on blocking stretch-activated ion channels.
Asunto(s)
Potenciales de Acción/efectos de los fármacos , Sistema de Conducción Cardíaco/efectos de los fármacos , Corazón/fisiopatología , Mecanotransducción Celular/efectos de los fármacos , Contracción Miocárdica/efectos de los fármacos , Infarto del Miocardio/fisiopatología , Estreptomicina/administración & dosificación , Animales , Relación Dosis-Respuesta a Droga , Corazón/efectos de los fármacos , Estimulación Física/métodos , Ratas , Ratas WistarRESUMEN
OBJECTIVE: To study the effect of integrative Chinese and Western medicine (ICWM) on improvement of the islet beta cell function in treating patients with latent autoimmune diabetes mellitus in adults (LADA). METHODS: Eighty-four patients of LADA were randomly divided into 3 groups (20 in A, 33 in B and 31 in C), they were treated respectively with sulfonylurea, insulin and combination of insulin and Chinese medicine. The changes before and after treatment in blood glucose, glycohemoglobin and islet beta cell function were observed. RESULTS: After treatment, the damaged islet beta cell function in Group A was not improved, the secrete peak value of C-peptide was still low and delayed in Group A, but in Group B and C, it shifted earlier, suggesting that a certain degree of improvement and recovery of islet beta cell function. The improving effect in Group C was better. CONCLUSION: Chinese herbal medicine had effect in lowering blood glucose and improving islet beta cell function in patients with diabetes mellitus, and showed a synergistic and enhancing action when combined use with insulin. Early treatment of insulin or combination of insulin and Chinese medicine should be applied to patients with LADA.