Menstrual and Reproductive Factors for Gastric Cancer in Postmenopausal Women: The 2007-2020 Korea National Health and Nutrition Examination Survey.

Globally, the incidence of gastric cancer is lower in women than in men. It is thought that menstrual and reproductive factors may be related to their lower incidence of gastric cancer. This cross-sectional study examined menstrual, reproductive, and other factors in 20,784 postmenopausal women from the 2007-2020 Korea National Health and Nutrition Examination Survey (KNHANES).

Adaptive R&D contract for urgently needed drugs: Lessons from COVID-19 vaccine development.

This paper analyzes an incentive contract for new vaccine research and development (R&D) under pandemic situations such as COVID-19, considering the R&D contract's adaptability to the pandemic. We study how the public sector (government) designs the adaptive R&D contract and offers it to pharmaceutical enterprises. An agency-theoretic model is employed to explore the contract whose terms are an upfront grant as a fixed fee and a sales tax credit as an incentive tool, examining how the values of related parameters affect contract term determinations.

Reduced port laparoscopic surgery for colon cancer is safe and feasible in terms of short-term outcomes: comparative study with conventional multiport laparoscopic surgery.

Purpose: Laparoscopic surgery was previously accepted as an alternative surgical option in treatment for colorectal cancer. Nowadays, single-port laparoscopic surgery (SPLS) is introduced as a method to maximize advantages of minimally invasive surgery. However, SPLS has several limitations compared to conventional multiport laparoscopic surgery (CMLS).

Influence of charge densities of randomly sulfonated polystyrene surfaces on cell attachment and proliferation.

Attachment and proliferation of NIH-3T3 fibroblast cells on random polymer surfaces, polystyrene sulfonated acid (PSSAx) with five different degrees of sulfonation (x = 0%, 5%, 10%, 15% and 33%) and on a tissue culture polystyrene (TCPS) surface were studied. The surface properties, wettability and roughness were measured by water-contact angle and atomic force microscopy measurement. The wettability and surface roughness increased with increasing the content of sulfonic acid groups on the surfaces.

Small-angle X-ray scattering study on poly(ethyl acrylate-co-itaconate) ionomers neutralized with various cations.

The morphology of poly(ethyl acrylate-co-itaconate) ionomers neutralized partly and fully with Na(I), Li(I) and Zn(II) was studied using a small-angle X-ray scattering (SAXS) technique. It was found that the SAXS peak position for the ionomers shifted to lower angle with increasing degree of neutralization for the ionomers containing 5.8 mol% of ionic repeat units.

Surface modification for polystyrene colloidal particles with controlled charge densities.

A significant amount of polystyrene sulfonated acid (PSSA) and poly(styrene-ran-acrylic acid) (PSAA) random copolymer can be adsorbed by dispersion of PS particles via a swelling-quenching process. A THF-water mixed solvent was used in the swelling process and a large amount of pure water was used, to give a low concentration of THF% in quenching process. Our results showed that functional PSSA groups were randomly and tightly adsorbed to the PS particles.