Domain-specific patterns of physical activity and risk of breast cancer sub-types in the MCC-Spain study.

PURPOSE: Literature on the separate effects of physical activities (PA) on risk of breast cancer (BC) sub-types is heterogeneous. We investigated domain-specific associations between PA and BC risk by menopausal status and molecular subtype. METHODS: 1389 histologically confirmed invasive BC cases and 1712 controls from the MCC-Spain study were included (age: 20-85 years). Questionnaire information on PA at work, at home, and during leisure time, including recreational PA and sedentary time, and data on reproductive history, anthropometry, family history of BC, diet, and lifestyles were obtained through face-to-face interviews. Information on the expression of oestrogen (ER), progesterone (PR), and HER2 receptors was available for > 95% of the cases. Mixed-effects multivariable logistic regression models were used to estimate odds ratios (OR) of BC sub-types. RESULTS: Occupational PA (OPA) intensity was associated with higher BC risk. Associations were stronger for pre-menopausal (ORactive/very active vs. sedentary job 1.89; 95% confidence interval (CI) 1.22, 2.91) and ER+/PR+, HER2- tumours (OR 1.80; 95% CI 1.28, 2.53). Sedentary time was associated with higher risk of post-menopausal BC (OR6-9 vs. <3 h/day 1.69; 95% CI 1.22, 2.32). Moderate-to-high-intensity household (HPA) and recreational PA (RPA) were inversely associated with BC occurrence in pre- and post-menopausal women, with estimated 14-33% lower risks (P for trend < 0.001) above 1000 MET·min/week. CONCLUSIONS: Higher levels of HPA and RPA were associated with lower risk of BC, with heterogeneity by molecular type, whereas sitting time was a consistent independent risk factor of BC risk. The positive association found for OPA with ER+/PR+ BC deserves further investigation.

Blends of nitrophenylmaleimide isomers with carboxymethylcellulose for the preparation of supramolecular polymers.

Novel water-compatible supramolecular polymers (WCSP) based on the non-covalent interaction between carboxymethylcellulose (CMC) and o, m, and p-nitrophenylmaleimide isomers are proposed. The non-covalent supramolecular polymer was obtained from high viscosity CMC with a degree of substitution 1.03 with o, m, and p-nitrophenylmaleimide molecules that were synthesized from maleic anhydride and its corresponding nitroaniline. Subsequently, blends were made at different nitrophenylmaleimide concentrations, stirring rate, and temperatures, with 1.5% CMC, to select the best conditions for each case and to evaluate the rheological properties. The selected blends were used to form films and analyze spectroscopic, physicochemical, and biological properties. Then, the interaction between a CMC monomer and each isomer of nitrophenylmaleimide was investigated using quantum chemistry computational calculations with the B3LYP/6-311 + G (d,p) method, providing a detailed explanation of their intermolecular interactions. The supramolecular polymers obtained exhibit an increase in viscosity of blends between 20% and 30% compared to CMC, a shift in the wavenumber of the OH infrared band by approximately 66 cm-1, and the first decomposition peak at the glass transition temperature occurring between 70 and 110 °C. These changes in properties are attributed to the formation of hydrogen bonds between the species. However, the degree of substitution and the viscosity of the CMC affects the physical, chemical, and biological properties of the polymer obtained. The supramolecular polymers are biodegradable regardless of the type of blends made and are easily obtainable. Notably, the CMC with m-nitrophenylmaleimide yields the polymer with the best properties.