Nanostructured materials with designable microstructure and controllable physical and chemical properties are highly desired for practical applications in nanotechnology. In this article, it is reported that nanoporous copper with a tunable nanopore size can be fabricated by controlling the dealloying process. The influence of acid concentration and etching potential on the formation of nanoprosity is systematically investigated. With optimal etching conditions, the nanopore sizes can be tailored from ∼15 to ∼120 nm by controlling the dealloying time. It is found that the tunable nanoporosity leads to significant improvements in surface‐enhanced Raman scattering (SERS) of nanoporous copper and peak values of SERS enhancements for both rhodamine 6G and crystal violet 10B molecules are observed at a pore size of ∼30–50 nm. This study underscores the effect of complex three‐dimensional nanostructures on physical and chemical properties and is helpful in developing inexpensive SERS substrates for sensitive instrumentations in molecular diagnostics.

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This study aimed to investigate the association between the prevalence of peptic ulcer disease (PUD) and mental health problems, such as severe stress, depressive mood, and suicidal ideation.The population-based cross-sectional study was comprised of 14,266 subjects participating in the fourth annual Korea National Health and Nutrition Examination survey from 2007 to 2009. The participants were divided into 2 groups according to the self-reported questionnaires: the PUD group and the non-PUD group. The association between PUD and mental health problems, such as severe stress, depressed mood, suicidal ideation, and psychological counseling history, were evaluated by using multivariate analysis and logistic regression.Among the 14,266 participants over 19-years old, 813 participants (5.6%) had PUD. Compared to the non-PUD group (n = 13,453), the PUD group had a significantly higher percentage of males, current smokers, and heavy drinkers, lower education status, lower income, and greater presence of diabetes mellitus, hypertension, metabolic syndrome and mental health problems, including severe stress, depressed mood, suicidal ideation, and psychological counseling history. After adjustment for lifestyle and medical and environmental factors, mental health problems were found to be associated with a significantly higher risk for PUD.Psychological problems, such as severe stress, depressed mood, suicidal ideation, and psychological counseling, were associated with PUD prevalence.