Plasmonic color filters fabricated via oxide-based nanotransfer printing.

Plasmonic filters have recently become a topic of significant interest because they are suitable for a wide range of applications. However, effective fabrication of plasmonic filters remains a challenge. In this paper, we demonstrate a simple method for fabricating plasmonic color filters based on nanotransfer printing (nTP) , using SiO2 as a hard mask for Al etching. nTP was performed on a 100 nm Al layer deposited on a glass wafer substrate with a 10 nm Al layer and a 20 nm SiO2 layer with a nanohole pattern. The 10 nm Al layer and 20 nm SiO2 layers were previously transferred from a polymer stamp prepared to create patterns of subwavelength-sized holes. The plasmonic filters were ultimately fabricated using the SiO2 layer as a hard mask to selectively etch the Al layer. The optical properties of the fabricated plasmonic filters were evaluated using experimental and simulation tools. In addition, we analyzed the results of nTP on the Al and SiO2 films by varying the temperature, pressure, and SiO2-film thickness. We believe that this technique is a promising method for fabricating nanostructures and for widening the scope of practical application of plasmonics because of its high efficiency and cost-effectiveness.

Lack of superoxide dismutase in a rad51 mutant exacerbates genomic instability and oxidative stress-mediated cytotoxicity in Saccharomyces cerevisiae.

A genetic analysis of synthetic lethal interactions in yeast revealed that the mutation of SOD1, encoding an antioxidant enzyme that scavenges superoxide anion radical, impaired the growth of a set of mutants defective in homologous recombination (HR) pathway. Hence, SOD1 inhibition has been proposed as a promising approach for the selective killing of HR-deficient cancer cells. However, we show that the deletion of RAD51 and SOD1 is not synthetic lethal but displays considerably slow growth and synergistic sensitivity to both reactive oxygen species (ROS)- and DNA double-strand break (DSB)-generating drugs in the budding yeast Saccharomyces cerevisiae. The function of Sod1 in regard to Rad51 is dependent on Ccs1, a copper chaperone for Sod1. Sod1 deficiency aggravates genomic instability in conjunction with the absence of Rad51 by inducing DSBs and an elevated mutation frequency. Inversely, lack of Rad51 causes a Sod1 deficiency-derived increase of intracellular ROS levels. Taken together, our results indicate that there is a significant and specific crosstalk between two major cellular damage response pathways, ROS signaling and DSB repair, for cell survival.

Covalent bonding-assisted nanotransfer lithography for the fabrication of plasmonic nano-optical elements.

Many high-resolution patterning techniques have been developed to realize nano- and microscale applications of electric devices, sensors, and transistors. However, conventional patterning methods based on photo or e-beam lithography are not employed to fabricate optical elements of high aspect ratio and a sub-100 nm scale due to the limit of resolution, high costs and low throughput. In this study, covalent bonding-assisted nanotransfer lithography (CBNL) was proposed to fabricate various structures of high resolution and high aspect ratio at low cost by a robust and fast chemical reaction. The proposed process is based on the formation of covalent bonds between silicon of adhesive layers on a substrate and oxygen of the deposited material on the polymer stamp. The covalent bond is strong enough to detach multiple layers from the stamp for a large area without defects. The obtained nanostructures can be used for direct application or as a hard mask for etching. Two nano-optical applications were demonstrated in this study, i.e., a meta-surface and a wire-grid polarizer. A perfect absorption meta-surface was generated by transferring subwavelength hole arrays onto a substrate without any post-processing procedures. In addition, a wire-grid polarizer with high aspect ratio (1 : 3) and 50 nm line width was prepared by the nano-transfer of materials, which were used as a hard mask for etching. Therefore, CBNL provides a means of achieving large-area nano-optical elements with a simple roll-to-plate process at low cost.

Yap1 and Skn7 genetically interact with Rad51 in response to oxidative stress and DNA double-strand break in Saccharomyces cerevisiae.

Reactive oxygen species (ROS)-mediated DNA adducts as well as DNA strand breaks are highly mutagenic leading to genomic instability and tumorigenesis. DNA damage repair pathways and oxidative stress response signaling have been proposed to be highly associated, but the underlying interaction remains unknown. In this study, we employed mutant strains lacking Rad51, the homolog of E. coli RecA recombinase, and Yap1 or Skn7, two major transcription factors responsive to ROS, to examine genetic interactions between double-strand break (DSB) repair proteins and cellular redox regulators in budding yeast Saccharomyces cerevisiae. Abnormal expression of YAP1 or SKN7 aggravated the mutation rate of rad51 mutants and their sensitivity to DSB- or ROS-generating reagents. Rad51 deficiency exacerbated genome instability in the presence of increased levels of ROS, and the accumulation of DSB lesions resulted in elevated intracellular ROS levels. Our findings suggest that evident crosstalk between DSB repair pathways and ROS signaling proteins contributes to cell survival and maintenance of genome integrity in response to genotoxic stress.

Prevalence of and factors associated with osteoporosis among Korean cancer survivors: a cross-sectional analysis of the Fourth and Fifth Korea National Health and Nutrition Examination Surveys.

BACKGROUND: Identifying and managing osteoporosis among cancer survivors is an important issue, yet little is known about the bone health of cancer survivors in Korea. This study was designed to measure the prevalence of osteoporosis and to assess related factors among Korean cancer survivors. MATERIALS AND METHODS: This study was designed as a cross-sectional analysis. Data were obtained from dual energy X-ray absorptiometry measurement of the lumbar vertebrae and femoral neck, and from standardized questionnaires among 556 cancer survivors and 17,623 non-cancer controls who participated in the Fourth and Fifth Korea National Health and Nutrition Examination Surveys (2008-2011). We calculated adjusted proportions of osteoporosis in non-cancer controls vs. cancer survivors, and we performed multivariate logistic regression analysis. RESULTS: The prevalence of osteoporosis among cancer survivors was significant higher than that of the non-cancer controls after adjusting for related factors. Furthermore, osteoporosis among cancer survivors was higher in elderly subjects (60-69 years : adjusted odds ratio (aOR) 3.04, 95% CI : 1.16-8.00, ≥70 years : aOR 6.60, 95% CI 2.20-19.79), in female cancer survivors (aOR: 7.03, 95% CI: 1.88-26.28), and in a group with lower monthly income (aOR: 3.38, 95% CI: 1.31-8.71). In male cancer survivors, underweight and lower calcium intake were risk factors. CONCLUSIONS: These data suggest that the osteoporosis among cancer survivors varies according to non-oncologic and oncologic factors. Effective screening should be applied, and a sufficient and comprehensive management should be matched to individual cancer survivors early after cancer treatment.

Alleviation of heat strain by cooling different body areas during red pepper harvest work at WBGT 33 degrees C.

The purpose of the present study was to examine the effects of different types of personal cooling equipments (PCE) on the alleviation of heat strain during red pepper harvest simulated in a climatic chamber. The experiment consisted of eight conditions: 1) Control, 2) Neck cooling scarf A with a cooling area of 68 cm2, 3) Neck cooling scarf B (cooling area 154 cm2), 4) Brimmed hat with a frozen gel pack, 5) Cooling vest (cooling area 606 cm2), 6) Hat+Neck Scarf B, 7) Hat+Vest, and 8) Hat+Neck Scarf B+Vest. Twelve subjects worked a red pepper harvest simulated in a climatic chamber of WBGT 33 degrees C. The result showed that rectal temperature (T(re)) was effectively maintained under 38 degrees C by wearing PCE. Mean skin temperature (T(sk)) and heart rate (HR) became more stable through wearing PCE. When wearing the 'Hat+Scarf B+Vest', particularly, T(sk) and HR quickly decreased to the comfort level during the mid-rest stage. We confirmed that the vest with a cooling area of only 3.3% body surface area (BSA) was effective in alleviating heat strain in a simulated harvest work. Furthermore, the heat strain of farm workers can be considerably eliminated by the combination of the cooling vest, a scarf, and a brimmed hat, with the total cooling area of 4.2% BSA.

Does wearing thermal underwear in mild cold affect skin temperatures and perceived thermal sensation in the hands and feet of the elderly?

The present study was to investigate whether increasing thermal insulation affects thermal sensation in the hands and feet; and whether aging is an influential factor in the relationship between thermal responses and subjective thermal perceptions. Six young males (YM), 5 young females (YF), 6 elderly males (OM), and 6 elderly females (OF) volunteered as subjects. Subjects conducted two trials at a constant air temperature of 19 degrees C: One condition included thermal underwear (19CUW) while the other did not (19C). The results showed that (1) rectal temperature (T(re)) did not show any significant differences between conditions with and without thermal underwear. The T(re) of the OF was greater than that of the YF (p<0.05) for the 19C condition, while the young and elderly male groups showed similar values. (2) The hand and foot skin temperatures (T(hand), T(foot)) were greater in the OF than in the YF group for the 19C condition (p<0.001). (3) For overall thermal sensation, the OF group was less sensitive to differences between the 19CUW and 19C condition, when compared with the old male and young groups. (4) For thermal sensation in the hands and feet, the elderly groups were less sensitive than the YF. In particular, all elderly females felt the hands were thermally neutral, even in the 19C condition. (5) Hand thermal sensation for the OF group appeared to be irrelevant to T(hand). (6) Thermal preference of the elderly groups did not change significantly after adding thermal underwear compared to the young group. In conclusion, wearing thermal underwear in mild cold did not affect local skin temperatures and thermal sensation in the hands and feet for the elderly male and female groups. Adding thermal underwear in mild cold affected the hand skin temperature and thermal sensation of the young female group. In particular, elderly females had specific features concerning local skin temperatures and thermal sensations distinguished from elderly males and young groups.