[Impacts of Nitrogen Application on Ammonia Volatilization During Maize Season in Northern China].

Ammonia volatilization is one of the major paths of nitrogen (N) loss and may exert a substantial impact on air quality. This study aims to explore the effects of nitrogen (N) fertilizer types, fertilization rate, and application timing and gas collection method on NH3 volatilization during the maize season in Northern China. This study collected the publications on the NH3 volatilization from maize farming which were conducted in Northern China from 1980 to 2018, and undertook a systematic analysis. The study found that with the increase of N rate, the total and net NH3 volatilization at the basal and topdressing fertilization stages increased at exponential and power function, respectively. When the ratio of basal/topdressing N rate was 1/1, the total and net NH3 volatilization during the topdressing stage (58.4% of the whole season emission) was significantly higher than that in the basal fertilization stage (41.6%) (P<0.05). The priming effect first showed a negative effect and then gradually turned into a positive effect with the increase of N rate. Due to the positive priming effect, the net NH3 volatilization, without considering the priming effect, was overestimated under the conventional N application (>297 kg·hm-2). There is a significant difference between the NH3 volatilization measured by the venting method and the sponge absorption method, and the data from the venting method are more stable (P<0.01). Compared with conventional urea, slow-release urea may reduce NH3 volatilization by 20% to 50%. Control fertilizer N rate at the topdressing stage is more efficient in reducing the NH3 volatilization from maize production in Northern China, and the venting method is more suitable for the quantification of NH3 volatilization than the sponge absorption method under a high rate of fertilizer N.

Factors distinguishing invasive from pre-invasive adenocarcinoma presenting as pure ground glass pulmonary nodules.

BACKGROUND: To investigate predictors of pathological invasiveness and prognosis of lung adenocarcinoma in patients with pure ground-glass nodules (pGGNs). METHODS: Clinical and computed tomography (CT) features of invasive adenocarcinomas (IACs) and pre-IACs were retrospectively compared in 641 consecutive patients with pGGNs and confirmed lung adenocarcinomas who had undergone postoperative CT follow-up. Potential predictors of prognosis were investigated in these patients. RESULTS: Of 659 pGGNs in 641 patients, 258 (39.1%) were adenocarcinomas in situ, 265 (40.2%) were minimally invasive adenocarcinomas, and 136 (20.6%) were IACs. Respective optimal cutoffs for age, serum carcinoembryonic antigen concentration, maximal diameter, mean diameter, and CT density for distinguishing pre-IACs from IACs were 53 years, 2.19 ng/mL, 10.78 mm, 10.09 mm, and - 582.28 Hounsfield units (HU). Univariable analysis indicated that sex, age, maximal diameter, mean diameter, CT density, and spiculation were significant predictors of lung IAC. In multivariable analysis age, maximal diameter, and CT density were significant predictors of lung IAC. During a median follow-up of 41 months no pGGN IACs recurred. CONCLUSIONS: pGGNs may be lung IACs, especially in patients aged > 55 years with lesions that are > 1 cm in diameter and exhibit CT density > - 600 HU. pGGN IACs of < 3 cm in diameter have good post-resection prognoses.

Pancreaticoduodenectomy for duodenal papilla carcinoma: A single-centre 9-year retrospective study of 112 patients with long-term follow-up.

AIM: To retrospectively evaluate the factors that influence long-term outcomes of duodenal papilla carcinoma (DPC) after standard pancreaticoduodenectomy (SPD). METHODS: This is a single-centre, retrospective study including 112 DPC patients who had a SPD between 2006 and 2015. Associations between serum levels of CA19-9 and CEA and various clinical characteristics of 112 patients with DPC were evaluated by the χ2 test and Fisher's exact test. The patients were followed-up every 3 mo in the first two years and at least every 6 mo afterwards, with a median follow-up of 60 mo (ranging from 4 mo to 168 mo). Survival analysis was conducted using the Kaplan-Meier survival and Cox proportional hazards model analysis. The difference in survival curves was evaluated with a log-rank test. RESULTS: In 112 patients undergoing SPD, serum levels of CA19-9 was associated with serum levels of CEA and drainage mode (the P values were 0.000 and 0.033, respectively); While serum levels of CEA was associated with serum levels of CA19-9 and differentiation of the tumour (the P values were 0.000 and 0.033, respectively). The serum levels of CA19-9 and CEA were closely correlated (χ² = 13.277, r = 0.344, P = 0.000). The overall 5-year survival was 50.00% for 112 patients undergoing SPD. The Kaplan-Meier survival analysis showed that increased serum levels of CA19-9, CEA, and total bilirubin were correlated with a poor prognosis, as well as a senior grade of infiltration depth, lymph node metastases, and TNM stage(the P values were 0.033, 0.018, 0.015, 0.000, 0.000 and 0.000, respectively). Only the senior grade of infiltration depth and TNM stage retained their significance when adjustments were made for other known prognostic factors in Cox multivariate analysis (RR = 2.211, P = 0.022 and RR = 2.109, P = 0.047). CONCLUSION: For patients with DPC, the serum levels of CA19-9 and CEA were closely correlated, and play an important role in poor survival. Increased serum levels of total bilirubin and lymph node metastases were also correlated with a poor prognosis. The senior grade of infiltration depth and TNM stage can serve as independent prognosis indexes in the evaluation of patients with DPC after SPD.