Development and validation of a risk prediction model for repeated indwelling urinary catheterization in patients with cervical cancer after surgery

Objective:To study the factors influencing secondary indwelling catheterisation after cervical cancer surgery and to develop a predictive risk model.Methods:A total of 260 patients in a tertiary hospital in Chongqing were selected from January 2020 to December 2021 via convenience sampling.Relevant information of patients was recorded,including age;body mass index;history of hypertension and diabetes,bladder dysfunction,postoperative urinary retention,and postoperative urinary tract infection;Histology;staging;surgical approach;Operation time;Time of first remove of catheter;indwelling catheter days;Hospitalization days.Least absolute shrinkage and selection operator was used to reduce dimensionality and select patient characteristics,and multivariate analysis was performed based on the selected variables.Based on the outcome of analysis,a line chart model was developed for predicting the risk of secondary catheterization in patients with indwelling catheterization after radical cervical cancer surgery.The coefficient of conformity index(C-index)and calibration curves were used to evaluate the accuracy and fit.The model was internally validated via bootstrapping(1000 random samples),and the clinical utility of the model was assessed via decision curve analysis(DCA).Results:Four characteristic variables were selected,including preoperative bladder function,postoperative urinary tract infection,surgical approach,and Time of first remove of catheter.They are independent risk factors affecting urinary tract.The risk prediction model exhibited good discrimination performance with a C-index of 0.722(95%CI,0.661-0.783)and was well calibrated.The C-index was 0.708 in internal validation analysis.DCA showed that the risk model was clinically useful for predicting secondary catheterization,and clinical benefits were observed at the decision threshold of≥11%.Conclusion:A novel model was developed to predict the risk of secondary catheterization.The model was based on preoperative bladder dysfunction,postoperative urinary tract infection,surgical approach,and number of days since the removal of the primary catheter.

ZnFe_(2)O_(4)/BiVO_(4)Z-scheme heterojunction for efficient visible-light photocatalytic degradation of ciprofloxacin

A novel Z-scheme ZnFe_(2)O_(4)/BiVO_(4)heterojunction photocatalyst was successfully synthesized using a convenient solvothermal method and applied in the visible light photocatalytic degradation of ciprofloxacin,which is a typical antibiotic contaminant in wastewater.The heterostructure of as-synthesized catalysts was confirmed using X-ray diffraction,scanning electron microscopy,transmission electron microscopy and X-ray photoelectron spectroscopy characterizations.Compared with the singlephase counterparts,ZnFe_(2)O_(4)/BiVO_(4)demonstrated considerably enhanced photogenerated charge separation efficiencies because of the Z-scheme transfer mechanism of electrons between the composite photocatalysts.Consequently,the 30%ZnFe_(2)O_(4)/BiVO_(4)catalyst afforded a degradation rate of up to 97%of 20 mg/L ciprofloxacin under 30 min of visible light irradiation with a total organic carbon removal rate of 50%,which is an excellent activity compared with ever reported BiVO_(4)-based catalysts.In addition,the liquid chromatography-mass spectrometry and quantitative structure-activity relationships model analyses demonstrated that the toxicity of the intermediates was lower than that of the parent ciprofloxacin.Moreover,the as-synthesized ZnFe_(2)O_(4)/BiVO_(4)heterojunctions were quite stable and could be reused at least four times.This study thus provides a promising Z-scheme heterojunction photocatalyst for the efficient removal and detoxication of antibiotic pollutants from wastewater.

Thermoresponsive block copolymer supported Pt nanocatalysts for base-free aerobic oxidation of 5-hydroxymethyl-2-furfural

A base-free catalytic system for the aerobic oxidation of 5-hydroxymethyl-2-furfural was exploited by using Pt nanoparticles immobilized onto a thermoresponsive poly(acrylamide-co-acrylonitrile)-b-poly(N-vinylimidazole)block copolymer,with an upper critical solution temperature of about 45°C.The Pt nanocatalysts were well-dispersed and highly active for the base-free oxidation of 5-hydroxymethyl-2-furfural by molecular oxygen in water,affording high yields of 2,5-furandicarboxylic acid(up to>99.9%).The imidazole groups in the block copolymer were conducive to the improvement of catalytic performance.Moreover,the catalysts could be easily separated and recovered based on their thermosensitivity by cooling the reaction system below the upper critical solution temperature.Good stability and reusability were observed over these copolymer-immobilized catalysts with no obvious decrease in catalytic activity in the five consecutive cycles.

Superior performance in visible-light-driven hydrogen evolution reaction of three-dimensionally ordered macroporous SrTiO_(3) decorated with Zn_(x)Cd_(1−x)S

It is of broad interest to develop emerging photocatalysts with excellent light-harvesting capacity and high charge carrier separation efficiency for visible light photocatalytic hydrogen evolution reaction.However,achieving satisfying hydrogen evolution efficiency under noble metal-free conditions remains challenging.In this study,we demonstrate the fabrication of three-dimensionally ordered macroporous SrTiO_(3)decorated with Zn_(x)Cd_(1−x)S nanoparticles for hydrogen production under visible light irradiation(λ>420 nm).Synergetic enhancement of photocatalytic activity is achieved by the slow photon effect and improved separation efficiency of photogenerated charge carriers.The obtained composites could afford very high hydrogen production efficiencies up to 19.67 mmol·g^(−1)·h^(−1),with an apparent quantum efficiency of 35.9%at 420 nm,which is 4.2 and 23.9 times higher than those of pure Zn_(0.5)Cd_(0.5)S(4.67 mmol·g^(−1)·h^(−1))and CdS(0.82 mmol·g^(−1)·h^(−1)),respectively.In particular,under Pt-free conditions,an attractive hydrogen production rate(3.23 mmol·g^(−1)·h^(−1))was achieved,providing a low-cost and high-efficiency strategy to produce hydrogen from water splitting.Moreover,the composites showed excellent stability,and no obvious loss in activity was observed after five cycling tests.