BackgroundA multicentre study was conducted to investigate the impact of sarcopenia as an independent predictor of oncological outcome after radical cystectomy for bladder cancer.MethodsIn total, 500 patients with available digital computed tomography scans of the abdomen obtained within 90 days before surgery were identified. The lumbar skeletal muscle index was measured using pre‐operative computed tomography. Cancer‐specific survival (CSS) and overall survival (OS) were estimated using Kaplan–Meier curves. Predictors of CSS and OS were analysed by univariable and multivariable Cox regression models.ResultsBased on skeletal muscle index, 189 patients (37.8%) were classified as sarcopenic. Patients with sarcopenia were older compared with their counterparts (P = 0.002), but both groups were comparable regarding to gender, comorbidity, tumor, node, metastasis (TNM) stage, and type of urinary diversion (all P > 0.05). In total, 234 (46.8%) patients died, and of these, 145 (29.0%) died because of urothelial carcinoma of the bladder. Sarcopenic patients had significantly worse 5 year OS (38.3% vs. 50.5%; P = 0.002) and 5 year CSS (49.5% vs. 62.3%; P = 0.016) rates compared with patients without sarcopenia. Moreover, sarcopenia was associated independently with both increased all‐cause mortality (hazard ratio, 1.43; 95% confidence interval 1.09–1.87; P = 0.01) and increased cancer‐specific mortality (hazard ratio, 1.42; 95% confidence interval, 1.00–2.02; P = 0.048). Our results are limited by the lack of prospective frailty assessment.ConclusionsSarcopenia has been shown to be an independent predictor for OS and CSS in a large multicentre study with patients undergoing radical cystectomy for bladder cancer.

A novel green lubricating oil additive (carbon quantum dot (CQD) particle-doped nickel (Ni-CQD)) was synthesized from citric acid and nickel acetate. The effects of CQD and Ni-CQD nanoparticles on the tribological behaviors of polyethylene glycol (PEG200) were investigated under different loads and reciprocation speeds. The results indicate that CQD and Ni-CQD particles can both enhance the lubrication properties of PEG200. However, the Ni-CQD nanoparticles enhanced the lubrication properties more than the plain CQD particles did. The average friction coefficient and wear rate of PEG200 containing 2 wt% Ni-CQDs were reduced by 35.5% and 36.4%, respectively, compared to PEG200 containing pure CQDs under a load of 8 N and reciprocation speed of 25 mm/s over 60 min. The friction and wear mechanisms are attributed to the fact that friction induces the Ni-CQDs to participate in the formation of a tribofilm, resulting in a low friction coefficient and wear rate.

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