Experimental and theoretical investigations on a CVD grown thin film of polymeric carbon nitride and its structure

A polymeric carbon nitride thin film has been grown using chemical vapor deposition. The characterization of the material shows that it has the same molecular composition as a formerly synthesized graphitic carbon nitride powder but both substances differ widely in their structural organization. In particular, our analyses reveal a paradoxical character in which the thin film sample exhibits simultaneously a high degree of organization in the stacking of the polymer sheets with strong inter-layer interactions, as expected from the growth technique, and a complete lack of crystallinity. A comprehensive theoretical study based on massive semi-empirical quantum chemistry computations has permitted to explain the properties of the material and to elucidate fundamental issues regarding the structural conformation of graphitic carbon nitride

Photocatalytic activity of a new composite material of Fe (III) oxide nanoparticles wrapped by a matrix of polymeric carbon nitride and amorphous carbon

Polymeric carbon nitride was synthesized from urea and doped with Cu and Fe to act as co-catalysts. The material doped with Fe was a new composite material composed of Fe(III) oxides (acting as a co-catalyst) wrapped by the polymer layers and amorphous carbon. Furthermore, the copper doped material was described in a previous report. The photocatalytic degradation of the azo dye direct blue 1 (DB) was studied using as photocatalysts: pure carbon nitride (CN), carbon nitride doped with Cu (CN-Cu) and carbon nitride doped with Fe (CN-Fe). The catalysts were characterized by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), by X-ray photoelectron spectroscopy (XPS) and Brunauer–Emmett–Teller method (BET), etc. The adsorption phenomenon was studied using the Langmuir and Freundlich models. For the kinetic study, a solution of 500 mg L-1 of DB1 was treated with each catalyst, visible light and H2O2. The dye concentration was measured by spectrophotometry at the wavelength of 565 nm, and the removal of the total organic content (TOC) was quantified. BET analysis yielded surface areas of 60.029, 20.116 and 70.662 m2g-1 for CN, CN-Cu and CN-Fe, respectively. The kinetics of degradation were pseudo-first order, whose constants were 0.093, 0.039 and 0.110 min-1 for CN, CN-Cu and CN-Fe, respectively. The total organic carbon (TOC) removal reached the highest value of 14.46% with CN-Fe

Predictors for anastomotic leak, postoperative complications, and mortality after right colectomy for cancer: Results from an international snapshot audit

Background: A right hemicolectomy is among the most commonly performed operations for colon cancer, but modern high-quality, multination data addressing the morbidity and mortality rates are lacking. Objective: This study reports the morbidity and mortality rates for right-sided colon cancer and identifies predictors for unfavorable short-term outcome after right hemicolectomy. Design: This was a snapshot observational prospective study. Setting: The study was conducted as a multicenter international study. Patients: The 2015 European Society of Coloproctology snapshot study was a prospective multicenter international series that included all patients undergoing elective or emergency right hemicolectomy or ileocecal resection over a 2-month period in early 2015. This is a subanalysis of the colon cancer cohort of patients. Main Outcome Measures: Predictors for anastomotic leak and 30-day postoperative morbidity and mortality were assessed using multivariable mixed-effect logistic regression models after variables selection with the Lasso method. Results: Of the 2515 included patients, an anastomosis was performed in 97.2% (n = 2444), handsewn in 38.5% (n = 940) and stapled in 61.5% (n = 1504) cases. The overall anastomotic leak rate was 7.4% (180/2444), 30-day morbidity was 38.0% (n = 956), and mortality was 2.6% (n = 66). Patients with anastomotic leak had a significantly increased mortality rate (10.6% vs 1.6% no-leak patients; p 65 0.001). At multivariable analysis the following variables were associated with anastomotic leak: longer duration of surgery (OR = 1.007 per min; p = 0.0037), open approach (OR = 1.9; p = 0.0037), and stapled anastomosis (OR = 1.5; p = 0.041). Limitations: This is an observational study, and therefore selection bias could be present. For this reason, a multivariable logistic regression model was performed, trying to correct possible confounding factors. Conclusions: Anastomotic leak after oncologic right hemicolectomy is a frequent complication, and it is associated with increased mortality. The key contributing surgical factors for anastomotic leak were anastomotic technique, surgical approach, and duration of surgery