Serum human epididymis protein 4 levels in the prediction of the recurrence of atrial fibrillation after catheter ablation.

The aim of this study is to assess serum human epididymis protein 4 (HE-4) levels as a biomarker for predicting the recurrence of atrial fibrillation (AF) after catheter ablation. This was a prospective observational study that enrolled one hundred eighty-four consecutive nonvalvular AF patients (65 persistent, 119 paroxysmal) who were eligible for their first ablation. Multiple Cox proportional hazards models and Kaplan-Meier curve analyses were used to test the association between serum HE-4 levels and AF recurrence after catheter ablation. During the 12-month follow-up, we observed that 47 patients (25.5%) experienced AF recurrence. Patients were divided into tertiles of HE-4 level (T1: < 50 pmol/L; T2: ≥ 50 pmol/L). The AF recurrence rate of higher serum HE-4 level patients was significantly increased (34.6% vs 13.8%, P < 0.001). Generalized additive models were used to visually assess functional relationships between the serum HE-4 levels and the risk of AF recurrence. When stratified with serum levels as the cut-off value, Kaplan-Meier analysis showed that patients with serum HE-4 levels (> 50 pmol/L) had a significantly increased risk of AF recurrence. In addition, multivariate Cox proportional hazard modelling revealed that HE-4 (≥ 50 pmol/L) (HR 2.65; 95% CI 1.34, 5.27, P = 0.005) was independent predictors of AF recurrence. Serum HE-4 levels in patients with AF are associated with postoperative recurrence of AF, and high HE-4 levels are an independent predictor of AF recurrence after ablation.

[Breviscapine protects bilateral testes of prepubertal rats after testicular torsion/detorsion].

Objective: To investigate the long-term protective effect of breviscapine on the bilateral testes of prepubertal rats after testicular torsion / detorsion. Methods: Thirty-two four-week-old healthy male SD rats were equally randomized into groups A(sham operation),B(normal saline),C(single-dose breviscapine, injected intraperitoneally at 2 mg per kg of the body weight at 30 min before testicular detorsion), and D( continuous-dosing breviscapine, injected intraperitoneally at 2 mg per kg of the body weight at 30 min before testicular detorsion qd for 7 days after surgery). At 6 weeks after establishment of the model of left testicular torsion /detorsion, the rats were sacrificed and the bilateral testes and epididymides harvested for detection of the total antioxidant capacity( TAOC),superoxide dismutase( SOD) level, nitric oxide synthase( NOS) activity, and malondialdehyde( MDA) content in the testis tissue, determination of sperm concentration, viability and motility, and observation of the pathological changes of the testis tissue. Results: Compared with group B, both groups C and D showed obvious increases in the levels of SOD,T-AOC and NOS and the concentration, survival rate and motility of sperm, but a remarkable decrease in the MDA content, with statistically significant differences(P < 0. 05) except in T-AOC, sperm concentration and motility in the contralateral testis of group C and in NOS activity in the bilateral testes of group D. In comparison with the ipsilateral testis of group C,group D exhibited markedly elevated levels of SOD,T-AOC and NOS, increased sperm concentration, viability and motility, and reduced content of MDA in the bilateral testes, with statistically significant differences( P < 0. 05) except in NOS activity in the contralateral testis. Bilateral seminiferous tubule degeneration and interstitial edema were observed in group B, more severe in the injured than in the contralateral testis. Obvious improvement was seen in the post-torsion / detorsion histological changes of the bilateral testis tissue in groups C and D. Conclusion: Breviscapine can obviously protect the bilateral testes of prepubertal rats after testicular torsion / detorsion by removal of oxygen free radicals and reduction of lipid peroxidation injury, and continuous dosing is even more effective than single-dose medication.

[Diffusive Fluxes and Controls of N2O from Coastal Rivers in Tianjin City].

Rivers are an important emission source of greenhouse gases. To explore the spatial characteristics and influencing factors of N2O emission from the coastal rivers in Tianjin City, six rivers into the Bohai Sea from different land-use types were selected, and the N2O concentrations, saturation, and diffusive fluxes were measured using the headspace-gas chromatography method. The N2O concentration was in supersaturation, and the rivers were the source of atmospheric N2O. The average concentration, saturation, and diffusive fluxes of N2O were (23.85±15.20) nmol·L-1, (309.71±197.38)%, and (27.04±16.46) µmol·(m2·d)-1, with the ranges of 12.70-115.69 nmol·L-1, 164%-1502%, and 9.17-244.79 µmol·(m2·d)-1, respectively. The N2O concentrations and diffusive fluxes of the rivers presented great spatial heterogeneity, with the sewage river (Huangdipai River)>urban river (Haihe River main stream, Jiyun River)>suburban river (Duliujian River, Yongding Xinhe River)>agricultural river (Chaobai Xinhe River). The N2O concentration and diffusion fluxes were significantly correlated with salinity, nutrients, and carbon sources. NO3--N and TP contributed greatly to the diffusive flux differences. N2O production and emission greatly related to the nitrogen cycle process in the Tianjin River, and different forms of nitrogen variously contributed to N2O diffusive fluxes. The salinity gradient had the opposite effect on the N2O emission in urban rivers and drainage rivers. The N2O diffusive fluxes of the sewage river in Tianjin were significantly higher than that of other river types. In the future, due to the development of urbanization and the expansion of urban land, more management measures should focus on the hotspots such as the downstream of wastewater treatment plants of sewage rivers, the estuaries of urban rivers, and the residential gathering areas of suburban rivers to reduce N2O emission.

Ammonia-oxidation as an engine to generate nitrous oxide in an intensively managed calcareous fluvo-aquic soil.

We combine field observations, microcosm, stoichiometry, and molecular and stable isotope techniques to quantify N2O generation processes in an intensively managed low carbon calcareous fluvo-aquic soil. All the evidence points to ammonia oxidation and linked nitrifier denitrification (ND) being the major processes generating N2O. When NH4(+)-based fertilizers are applied the soil will produce high N2O peaks which are inhibited almost completely by adding nitrification inhibitors. During ammonia oxidation with high NH4(+) concentrations (>80 mg N kg(-1)) the soil matrix will actively consume oxygen and accumulate high concentrations of NO2(-), leading to suboxic conditions inducing ND. Calculated N2O isotopomer data show that nitrification and ND accounted for 35-53% and 44-58% of total N2O emissions, respectively. We propose that slowing down nitrification and avoiding high ammonium concentrations in the soil matrix are important measures to reduce N2O emissions per unit of NH4(+)-based N input from this type of intensively managed soil globally.

Greenhouse gas emissions from a wheat-maize double cropping system with different nitrogen fertilization regimes.

Here, we report on a two-years field experiment aimed at the quantification of the emissions of nitrous oxide (N2O) and methane (CH4) from the dominant wheat-maize double cropping system in North China Plain. The experiment had 6 different fertilization strategies, including a control treatment, recommended fertilization, with and without straw and manure applications, and nitrification inhibitor and slow release urea. Application of N fertilizer slightly decreased CH4 uptake by soil. Direct N2O emissions derived from recommended urea application was 0.39% of the annual urea-N input. Both straw and manure had relatively low N2O emissions factors. Slow release urea had a relatively high emission factor. Addition of nitrification inhibitor reduced N2O emission by 55%. We conclude that use of nitrification inhibitors is a promising strategy for N2O mitigation for the intensive wheat-maize double cropping systems.