Search

The 1‐year mortality and health consequences of COVID‐19 in cancer patients are relatively underexplored. In this multicenter cohort study, 166 COVID‐19 patients with cancer were compared with 498 non‐cancer COVID‐19 patients and 498 non‐COVID cancer patients. The 1‐year all‐cause mortality and hospital mortality rates in Cancer COVID‐19 Cohort (30% and 20%) were significantly higher than those in COVID‐19 Cohort (9% and 8%, both P

Background The study aim was to investigate one-year all-cause mortality and health consequences of cancer COVID-19 patients in China, stratified by primary tumor subtype. Methods In this multicenter cohort study, 166 cancer COVID-19 patients were studied along with 498 gender- and age-matched non-cancer COVID-19 patients in four hospitals in Wuhan, China, admitted 2020/01/01-2020/03/18, as well as with 498 parallel gender-, age-, and cancer subtype- matched non-COVID cancer patients hospitalized between 2019/01/01-2020/03/17. All patients were followed-up with a telephone survey to assess health consequences. Cox proportional hazards regression were used for risk analysis. Results In the three cohorts of median age of 65 ± 1 year and 49% male, the one-year all-cause mortality and hospital mortality rates of Cancer COVID-19 Cohort, 30% and 20% respectively, were significantly higher than COVID-19 Cohort (9% and 8%), and Cancer Cohort (16% and 2%). The 12-month all-cause post-discharge mortality rate of Cancer COVID-19 Cohort (11%) was higher than COVID-19 Cohort (0.4%), but similar to Cancer Cohort (15%). The high 1-year all-cause mortality was among hematologic malignancies (65%) and then nasopharyngeal, brain and skin tumors (45%), digestive system (43%), and lung (32%). the rate was low among genitourinary (14%), female genital (13%), breast (11%), and thyroid (0). As for patients having at least one symptom at the 1-year follow-up, Cancer COVID-19 Cohort (23%, 26/114) is similar to COVID-19 Cohort (30%, 130/432). Discussion Cancer COVID-19 patients showed a high rate of hospitalization mortality, but not after discharged, signifying the strong acute adverse effect of COVID-19 on cancer patients while little was in long-term effect. Risk stratification showed that hematologic malignancies, nasopharyngeal, brain, digestive system and lung tumors were high risk, while genitourinary, female genital, breast and thyroid were low risk which was similar to non-cancer COVID-19. Conclusions COVID-19 had little effect of 1-year mortality and sequelae for cancer survivors discharged from SARS-CoV-2 virus infection. Different tumor subtypes had different effect of COVID-19. COVID-19 patients with thyroid, breast, female genital, genitourinary tumor had low risk mortality which was similar to non-cancer patients.

C/C–SiC ceramic is a promising braking material in high-speed trains. The research on wet braking is necessary for its application. In this paper, braking tests of C/C–SiC disc mated with powder metallic (P/M) pads were conducted under dry, wet and recovery braking conditions at initial braking speed (IBS) of 14, 22, 33, 44, 55 m/s. Coefficient of friction (COF) and surface morphologies under different conditions were discussed: The instantaneous COF under wet condition was lower but the instantaneous COF curves became smoother than those under dry condition. The difference between two conditions went smaller as IBS increased. Under recovery condition, it cost 33 stops at 14 m/s to recover to 93.1% of the origin COF. Meanwhile, 8 stops were needed at 55 m/s, and the recovery rate was 98.9%. When the IBS increased, the number of the stop needed was fewer and the recovery rate was higher. The surface morphologies further showed the braking under wet condition resulted in a smoother surface with less ploughing grooves and the disappearance of the friction film. Under the recovery condition, the surface became rough again with grooves and the friction film formed again. The results indicate that the wear debris were washed away by the sprayed water and the formation of friction film was inhibited. In addition, water film subsequently lubricated the friction surface, which reduced COF at low IBS. As IBS increased, high temperature accelerated the dewatering and evaporation of water and thus lead to the decrement of the COF difference between wet and dry friction which, in turn accelerated the recovery process.

Ethnopharmacological relevance Anoectochilus roxburghii (A. roxburghii) is a popular folk medicine in many Asian countries, which has been used traditionally for treatment of some diseases such as diabetes, tumors, hyperlipemia, and hepatitis. The ethanol extract from A. roxburghii was recently shown to exert better ability to scavenge free radicals in vitro and possess antioxidant on natural aging mice in vivo. Aim of the study This study is to characterize the chemical composition, and investigate the protective effect of the A. roxburghii flavonoids extract (ARF) against hydrogen peroxide (H2O2)-induced oxidative stress in LO2 cells in vitro and D-galactose (D-gal)-induced aging mice model in vivo, and explore the underlying mechanisms. Materials and methods The chemical components of the flavonoids extract fro m A. roxburghii were detected by ultraperformance lipid chromatography coupled with quadrupole-time-of-flight mass spectrometry (UPLC-QTOF-MS/MS). H2O2 was used to establish an oxidative stress model in LO2 cells. Cytotoxic and protective effects of ARF on the LO2 cells were determined using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method. Moreover, the levels of superoxide dismutase (SOD), glutathione peroxidase (GSH-PX), and malondialdehyde (MDA) in cell supernatants were measured by commercial reagent kits. Kun-Ming mice were induced to aging with D-gal (400 mg/kg, BW) by subcutaneous injection for 58 days. From the 28th day to the 58th day of D-gal treatment, ARF (122.5, 245 and 490 mg/kg, BW) and vitamin E (100 mg/kg, BW) were orally administrated to aging mice once a day for consecutive 30 days. After 25 days of the treatment with ARF, learning and memory were assessed using Morris Water Maze (MWM). At the end of the test period, the animals were euthanized by cervical dislocation, and the levels of SOD, GSH-PX, and MDA in serum, liver homogenates and brain homogenates were measured. The levels of monoamine oxidase (MAO) and acetylcholinesterase (AchE) were determined in brain homogenates. Skin and liver histopathological morphology were observed by H&E staining. Furthermore, antioxidant-related gene expression levels in the liver were carried out by quantitative real-time polymerase chain reaction (qRT-PCR). Results Nine flavonoids were identified in the extracts of A. roxburghii. In vitro assay, a high concentration of ARF (>612.5 μg/ml) reduced the survival rate and had toxic effects on LO2 cells. In addition, ARF (245 μg/ml, 490 μg/ml) and Vitamin C (200 μg/ml) markedly inhibited generations of MDA and increased activities of SOD, GSH-PX in H2O2-induced LO2 cells supernatants. In vivo assay, ARF (122.5 mg/kg, 245 mg/kg and 490 mg/kg) and Vitamin E (100 mg/kg) not only ameliorated learning and memory ability but also improved skin and liver pathological alterations. Strikingly, ARF significantly decreased MDA and MAO levels, markedly enhanced antioxidant enzyme (SOD and GSH-PX) activities. Further, compared to the D-gal group, ARF could obviously up-regulate glutathione peroxidase-1 (GPx-1) and glutathione peroxidase-4 (GPx-4) mRNA levels. Conclusions These findings suggested that ARF protects LO2 cells against H2O2-induced oxidative stress and exerts the potent anti-aging effects in D-gal aging mice model, which may be related to the inhibition of oxidative stress. Flavonoid compounds may contribute to the anti-oxidative capability and modulating aging.

The improvement of braking systems for the high-speed train is driven by the demand for high & stable coefficient of friction (COF) as well as low wear at high speed. Given to the fading COF and severe wear of powder metallurgy (P/M) pad mated steel disk serving high-speed train in present, C/C–SiC ceramic materials are regarded as a strong candidate for braking disk due to the excellent strength, fracture toughness coupled with relatively low density. The fundamental understanding of the braking behavior at different braking speeds should be clarified for optimal application. In this work, P/M pads and C/C–SiC ceramic disk were prepared, braking tests with the initial braking speeds (IBS) of 15, 22, 30, 37, 46, 55, 59, 64, 69 m/s were conducted, and the surface development, friction & wear behavior were analysed. The COF vs. IBS curve shows a three-stage changing based on the turning points due to the contact patches continuously forming, growing and degrading: it went down and reached a low point with a value of 0.443 at 37 m/s, then increased gradually and reached the maximum 0.486 at 55 m/s, then little fell to 0.460 at 69 m/s. In the great scope of braking speeds, P/M pads mated C/C–SiC ceramic disk showed both high mean friction coefficient of 0.469 and high stability coefficient of 0.908, which are higher than the corresponding values of same P/M pads mated with typical steel disk (0.381 for COF and 0.895 for stability coefficient). Furthermore, at the highest speed tested, the wear rate of the pad mated with the ceramic disk is 0.147 cm3/MJ, far lower than that with steel mate: 0.338 cm3/MJ, showing desired properties for the high-speed train, owing to slight adhesion between ceramic disk and metal matrix of the pad.