[Effects of Farming Practices on Soil Nitrogen and Phosphorus Concentrations and Its Loss in the Drawdown Area of the Tributary Embayment of the Three Gorges Reservoir].

As the Three Gorges Reservoir (TGR) periodically operates at low water levels, its drawdown area has been utilized for cultivation by local farmers due to the overlap of the non-inundated period and the crop-growth period. However, traditional agricultural planting may affect the aquatic environment of the TGR area. To explain the effects of agricultural farming and abandoned farming on the water environment, a study was conducted in the drawdown area in an embayment of the Pengxi River (a tributary of the TGR). Corn, potato, and peanut fields were investigated for nitrogen and phosphorus content in surface soil, during the farming period (March to September 2018) and the conversion period (March to September 2019). Nitrogen and phosphorus balance models were constructed for farmland and abandoned farmland, to compare and analyze the budgets and loss risk of nitrogen and phosphorus from soil in the drawdown area. The results showed that the ammonia nitrogen (NH4+-N), total phosphorus (TP), and inorganic phosphorus (IP) content of soil in the corn field varied significantly across different planting periods. The concentrations of ammonium nitrogen and nitrate nitrogen (NO3--N) were significantly higher in farmland soil than in abandoned farmland soil, and the concentrations of total phosphorus (TP), inorganic phosphorus (IP), and calcium-bound phosphorus (Ca-P) were significantly lower in farmland soil than in abandoned farmland soil. The different soils were ranked according to the intensity of nitrogen and phosphorus surplus as follows:corn field>potato field>peanut field. The apparent surplus values in the different farmland soils were 76.89 kg ·hm-2(corn field), 51.92 kg ·hm-2(potato field), and 43.74 kg ·hm-2(peanut field) for nitrogen, and 79.69 kg ·hm-2(corn field), 75.76 kg ·hm-2(potato field), and 17.78 kg ·hm-2(peanut field) for phosphorous. Overall, the surplus intensities of nitrogen and phosphorus in all three croplands were higher than the respective risk thresholds, indicating potential nitrogen and phosphorus pollution in the three farmland types. Agricultural farming in the drawdown area may therefore increase the risk of nitrogen and phosphorus loss and is not conducive to the protection of the aquatic environment.

Cystic duct cancer: Should it be deemed as a type of gallbladder cancer?

BACKGROUND: According to the latest American Joint Committee on Cancer and Union for International Cancer Control manuals, cystic duct cancer (CC) is categorized as a type of gallbladder cancer (GC), which has the worst prognosis among all types of biliary cancers. We hypothesized that this categorization could be verified by using taxonomic methods. AIM: To investigate the categorization of CC based on population-level data. METHODS: Cases of biliary cancers were identified from the Surveillance, Epidemiology, and End Results 18 registries database. Together with routinely used statistical methods, three taxonomic methods, including Fisher's discriminant, binary logistics and artificial neuron network (ANN) models, were used to clarify the categorizing problem of CC. RESULTS: The T staging system of perihilar cholangiocarcinoma [a type of extrahepatic cholangiocarcinoma (EC)] better discriminated CC prognosis than that of GC. After adjusting other covariates, the hazard ratio of CC tended to be closer to that of EC, although not reaching statistical significance. To differentiate EC from GC, three taxonomic models were built and all showed good accuracies. The ANN model had an area under the receiver operating characteristic curve of 0.902. Using the three models, the majority (75.0%-77.8%) of CC cases were categorized as EC. CONCLUSION: Our study suggested that CC should be categorized as a type of EC, not GC. Aggressive surgical attitude might be considered in CC cases, to see whether long-term prognosis could be immensely improved like the situation in EC.

Can retrohepatic tunnel be quickly and easily established for laparoscopic liver hanging maneuver by Goldfinger dissector in laparoscopic right hepatectomy?

OBJECTIVE: The liver hanging maneuver (LHM) is rarely applied in laparoscopic right hepatectomy (LRH) because of the difficulty encountered in retrohepatic tunnel (RT) dissection and tape positioning. Thus far no report has detailed how to quickly and easily establish RT for laparoscopic LHM in LRH, nor has employment of the Goldfinger dissector to create a total RT been reported. This study's aim was to evaluate the safety and feasibility of establishing RT for laparoscopic LHM using the Goldfinger dissector in LRH. METHODS: Between March 2015 and July 2015, five consecutive patients underwent LRH via the caudal approach with laparoscopic LHM. A five-step strategy using the Goldfinger dissector to establish RT for laparoscopic LHM was adopted. Perioperative data were analyzed. RESULTS: The median age of patients was 58 (range, 51-65) years. Surgery was performed for one intrahepatic lithiasis and four hepatocellular carcinomas with a median size of 90 (40-150) mm. The median operative time was 320 (282-358) min with a median blood loss of 200 (200-600) ml. Laparoscopic LHM was achieved in a median of 31 (21-62) min, and the median postoperative hospital stay was 14 (9-16) d. No transfusion or conversion was required, and no severe liver-related morbidity or death was observed. CONCLUSIONS: The Goldfinger dissector is a useful instrument for the establishment of RT. A five-step strategy using the Goldfinger dissector can quickly and easily facilitate an RT for a laparoscopic LHM in LRH.