The use of nitrification inhibitors has been suggested as a strategy to decrease cadmium(Cd)accumulation in crops.However,the most efficient nitrification inhibitor for mitigating crop Cd accumulation remains to be elucidated,and whether and how changes in soil microbial structure are involved in this process also remains unclear.To address these questions,this study applied three commercial nitrification inhibitors,namely,dicyandiamide(DCD),3,4-dimethylpyrazole phosphate(DMPP),and nitrapyrin(NP),to pakchoi.The results showed that both DCD and DMPP(but not NP)could efficiently decrease Cd concentrations in pakchoi in urea-and ammonium-fertilized soils.In addition,among the three tested nitrification inhibitors,DMPP was the most efficient in decreasing the Cd concentration in pakchoi.The nitrification inhibitors decreased pakchoi Cd concentrations by suppressing acidification-induced Cd availability and reshaping the soil microbial structure;the most effective nitrification inhibitor was DMPP.Ammonia oxidation generates the most protons during nitrification and is inhibited by nitrification inhibitors.Changes in environmental factors and predatory bacterial abundance caused by the nitrification inhibitors changed the soil microbial structure and increased the potential participants in plant Cd accumulation.In summary,our study identified DMPP as the most efficient nitrification inhibitor for mitigating crop Cd contamination and observed that the soil microbial structural changes caused by the nitrification inhibitors contributed to decreasing Cd concentration in pakchoi.

OBJECTIVETo analyze the correlation between mitral regurgitation grading and left ventricular ejection fraction in elderly patients (>60 years of age) in a 2-year follow-up.

METHODSA total of 455 patients with the diagnosis of at least mild mitral regurgitation by echocardiography were divided into ischemic mitral regurgitation (IMR) group and non-ischemic regurgitation (NIMR) group. The patients were followed up with echocardiography every 6 months and the data were analyzed at the end of 24 months.

RESULTSMitral regurgitation grade was inversely correlated with left ventricular ejection fraction (LVEF). Patients with moderate and severe IMR had a lower LVEF than those with NIMR (P<0.05). After adjustment for age, sex, body mass index, high blood pressure, diabetes, atrial fibrillation and cardiomyopathy, the mean LVEF at 2 years was lowered by 2.7% (1.4%-4.1%), 2.7% (1.3%-4.0%), and 5.2% (3.5%-6.9%) in mild, moderate and severe IMR patients, respectively (P<0.04), and by 3.2% (1.6%-4.8%), and 3.0% (1.4%-4.5%), and 1.7%(-0.5%-3.9%) in mild, moderate and severe NIMR patients (P=0.30).

CONCLUSIONThe mean LVEF in IMR patients is significantly lowered compared to that in NIMR patients. The grade of mitral regurgitation is inversely correlated with the regurgitation area in IMR patients. Stratified management might help improve LVEF in severe IMR patients.

Aged ; Aged, 80 and over ; Female ; Follow-Up Studies ; Humans ; Male ; Mitral Valve Insufficiency ; Stroke Volume ; Ventricular Dysfunction, Left ; physiopathology

Objective :To evaluate therapeutic effect of allisartan isoproxil tablet on carotid atherosclerosis (CAS) le‐sion in patients with mild to moderate essential hypertension (EH).Methods :A total of 120 patients with mild to moderate EH complicated CAS treated in our hospital were enrolled .They were randomly divided into valsartan group (n＝60 ,received valsartan 80mg／d) and allisartan isoproxil group (n＝60 ,received allisartan isoproxil tablet 240mg／d) ,both groups received measure by carotid vascular ultrasound before treatment ,24 weeks and 48 weeks af‐ter treatment and its result were compared between two groups .Results :Compared with before treatment ,there were significant reductions in IMT ,size ,thickness and number of carotid atherosclerotic plaques on 24 weeks and 48 weeks after treatment in two groups ,and above indexes of 48 weeks were significantly lower than those of 24 weeks , P＜0.05 or ＜0.01. The decreased value of IMT in allisartan isoproxil group was significantly higher than that of valsartan group ,and there were no significant difference between two groups in time point of size ,thickness and number of carotid atherosclerotic plaques , P＞0.05 all.Conclusion :Therapeutic effect of two drugs on size ,thick‐ness and number of carotid atherosclerotic plaques are similar ;but therapeutic effect of allisartan isoproxil tablet on IMT is significantly better than that of valsartan .