The risk factors of environmental contamination by SARS-CoV-2 are largely unknown. We analyzed 1,320 environmental samples obtained from COVID-19 patients over 1 year. The risk factors for contamination of COVID-19 patients’ surrounding environment were higher viral load in the respiratory tract and shorter duration from symptom onset to sample collection.

Given the dynamic characteristic of an individual’s drinking behaviours, comprehensive consideration of alcohol consumption variation using repeated measures may improve insight into the nature of its association with blood pressure (BP) change. We examined the association between longitudinal alcohol consumption (trajectory and quantity) and changes in BP and pulse pressure (PP) among Korean aged ≥ 40 years living in rural areas. Totally, 1682 hypertension-free participants who completed all three health examinations (median, 5·3 years) were included. All three visits were used to determine the cumulative trajectory of and quantity of alcohol consumption and the latest two visits and the last visit were used for the recent trajectory and the most recent quantity of alcohol consumption, respectively. Changes in BP and PP from the baseline to the third visit were used as outcome. In men, ≥30 ml/d cumulative average alcohol consumption was associated with the greatest increase in systolic BP (SBP) in both baseline outcome-unadjusted (2·9 mmHg, P = 0·032) and -adjusted models (3·6 mmHg, P = 0·001), and the given association for the most recent alcohol consumption was observed in the baseline outcome-adjusted model (3·9 mmHg, P = 0·003). For PP, similar associations were observed only in the baseline outcome-adjusted model. No meaningful associations in diastolic BP in men and any BP or PP in women existed. The quantity of alcohol consumption rather than the trajectory may be significantly related to raised SBP, and a possible short-term influence of the most recent alcohol consumption may exist when baseline SBP is adjusted in men.

We have developed new flexible dye-sensitized solar cells (DSSCs) comprising organic dye (JH-1), cobalt redox electrolyte and hierarchically structured TiO2 (HS-TiO2) photoelectrode prepared using an electrostatic spray method. The performance of JH-1 sensitized flexible DSSC with a cobalt redox electrolyte was compared with those of N719-based DSSC and DSSC with I-/ I3- redox electrolyte. As a result, JH-1 sensitized flexible DSSC with [Co(Ⅲ/Ⅱ)(bpy-pz)3](PF6)3/2 redox system exhibited a high photocurrent density of 9.17 mA cm-2, an open circuit voltage of 0.953 V, a fill factor of 0.70, and a power conversion efficiency of 6.12% under 1 sun illumination (100 mW cm-2). The incident photon-to-current conversion efficiency was measured to explain the photocurrent generation difference by different dyes and electrolytes. The electron recombination lifetime of cells was measured by intensity-modulated photovoltage spectroscopy. Mass transport in DSSCs employing cobalt redox electrolytes was also investigated by the photocurrent transient measurements and electrochemical impedance spectroscopy (EIS) analysis.

It has not been well established whether dietary folate intake reduces the risk of diabetes development. We aimed to clarify the prospective association between dietary folate intake and type 2 diabetes (T2D) risk among 7333 Korean adults aged 40 years or older who were included in the Multi-Rural Communities Cohort. Dietary folate intake was estimated from all 106 food items listed on a FFQ, not including folate intake from supplements. Two different measurements of dietary folate intake were used: the baseline consumption and the average consumption from baseline until just before the end of follow-up. The association between folate intake and T2D risk was determined through a modified Poisson regression model with a robust error estimator controlling for potential confounders. For 29 745 person years, 319 cases of diabetes were ascertained. In multivariable analyses, dietary folate intake was inversely associated with risk of T2D for women, not for men. For women, the incidence rate ratio of diabetes in the third tertile compared with the first tertile was 0·57 (95 % CI 0·38–0·87, Pfor trend=0·0085) in the baseline consumption model and 0·64 (95 % CI 0·43–0·95, Pfor trend=0·0244) in the average consumption model. These inverse associations was found in both normal fasting blood glucose group and impaired fasting glucose group among women. Among non-users of multinutrients and vitamin supplements, the significant inverse association remained. Thus, higher dietary intake of folate is prospectively associated with lower risk of diabetes for women.

To trace the surficial responses of lowlands to past climate change, we investigated δ13C in total organic carbon (TOC), C/N ratios, magnetic susceptibility (MS), and silicon (Si) intensity (directly proportional to concentration) in wetland sediments collected from the Gimpo area of central Korea, covering 6600–4600 cal yr BP. Two organic layers with high TOC%, negatively depleted δ13CTOC values (− 27 to − 29‰), low MS values, and low Si intensities were found at 6200–5900 and 5200–4800 cal yr BP, respectively. These middle Holocene wet periods corresponded to relatively intensified summer monsoon and solar activity periods. The intervening dry period (5900–5200 cal yr BP) with high MS, high Si, and low TOC% corresponded to an intensified dust-activity interval and stronger winter monsoon. This multi-centennial climatic fluctuation of wet periods (6200–5900 cal yr BP and 5200–4800 cal yr BP) and an intervening dry period (5900–5200 cal yr BP) in central Korea was more synchronous with climate change in the arid inner part of China than with that in South China, suggesting possible strong high-latitude-driven climatic influences (e.g., North Atlantic cooling events) during the middle Holocene.

Diet may play an important role in breast cancer recurrence or survival, and therefore assessment of long-term diet among breast cancer survivors is important in breast cancer survivorship research. Given that the diet of breast cancer survivors may differ from that of the general population, the use of a FFQ specific to this group may be needed. The objective of this study was to develop a FFQ for breast cancer survivors, the most commonly used tool to measure long-term dietary patterns in nutritional epidemiological studies. We collected information on the foods and amounts of foods consumed using 3-d dietary records from a total of 192 women who had been diagnosed with stage I–III breast cancers and had undergone breast cancer surgery at least 6 months before the baseline study. A total of 1254 foods and dishes consumed were re-grouped by the similarity of the main ingredients and/or serving units, and several dishes commonly consumed among the Korean population were added. After we performed contribution analyses and variability analyses to detect between-person variation for selected nutrients, we listed a total of 123 foods and dishes for the FFQ specific to breast cancer survivors. Our breast cancer survivor-specific FFQ can be used to estimate long-term dietary intake and to examine its association with breast cancer prognosis in epidemiological studies of breast cancer in Korea.

Multivariate analytical methods, which have been used effectively in work on scleractinian corals, were applied to tabulate corals. The study involved discrimination and characterization of closely related species of Catenipora from the Selkirk Member, Red River Formation, in Manitoba. Ten morphological characters measured in transverse sections of 37 coralla were tested to perform cluster analyses. Results of correlation analysis and principal component analysis indicated that five of the characters would be suitable: tabularium area, corallite length, corallite width, tabularium length, and tabularium width.

A cluster analysis was performed on the raw data matrix coordinated with 37 coralla by the five selected morphological characters. The characters were standardized to mean 0 and variance 1, and squared Euclidean distances among the coralla were calculated. The unweighted pair-group method using arithmetic average was also employed for clustering the coralla. Four morphospecies were consequently extracted from the dendrogram, which was based on the variation of the five morphological characters, and were confirmed by two types of discriminant analysis. Morphospecies A, B, and D have distinctive ranges in variation of all characters except corallite length. Morphospecies C appears to be an intermediate form, in which the ranges of variation of all five morphological characters partially overlap with those of morphospecies A and/or B.

Another cluster analysis, including eight type specimens of Ordovician species previously reported from Manitoba, was performed on the data matrix coordinated with 45 coralla by the five morphological characters. Based on this analysis and morphological comparisons, morphospecies A–C are identified as C. rubra Sinclair and Bolton in Sinclair, 1955, C. foerstei Nelson, 1963, and C. robusta (Wilson, 1926) of Nelson, 1963 (=C. cf. robusta herein), respectively. Morphospecies D is equated with both C. agglomeratiformis (Whitfield, 1900) of Nelson, 1963 and C. aequabilis (Teichert, 1937) of Nelson, 1963 (=C. cf. agglomeratiformis herein). The result of cluster analysis based on the five selected morphological characters demonstrates efficiency in distinguishing closely related species of Catenipora from southern Manitoba. The same procedure should also be applicable to other cateniform corals.

Multivariate morphometric analysis was applied for differentiation of closely related species and evaluation of intra- and interspecific variation in Manipora from the Selkirk Member, Red River Formation, in southern Manitoba. Seven morphological characters were quantified in transverse thin sections of 46 coralla and statistically tested for selecting effective characters in discriminating species. Cluster analysis was performed on a raw data matrix coordinated with 46 coralla by three selected characters. Two major clusters on the resulting dendrogram were regarded as morphospecies, following comparative examination of the coralla using serial sections. Cluster analyses were also conducted on principal component score matrices obtained from the raw data set coordinated with 46 coralla by all seven characters, and from an experimental data set including the 46 coralla plus two replicates of each and six of the characters. the results agree closely with the first cluster analysis, but discrimination of morphospecies was slightly degraded. the validity of two morphospecies recognized in the first cluster analysis was verified by discriminant analyses, descriptive statistics, and bivariate plots. the results show that tabularium area is the most meaningful character for distinguishing these morphospecies; ranges of variations of the other six characters overlap between morphospecies.

Another cluster analysis like the first was performed, but with the addition of 11 type specimens and reference coralla of Manipora species from the Upper Ordovician of southern and northern Manitoba and Texas. Based on this analysis, together with comparative examination of thin sections, the two morphospecies are identified as valid species: M. amicarum Sinclair, 1955 and M. manitoba (Sokolov, 1955). Manipora magna Flower, 1961 is considered to be a synonym of M. amicarum, while M. trapezoidalis Flower, 1961 and M. garsonensis Caramanica, 1992 are considered to be synonyms of M. manitoba, and the hypotypes of M. amicarum of Nelson (1963) are assigned to M. manitoba.

The uppermost Lower Silurian and Upper Silurian Gascons and West Point Formations of the southern Gaspé Peninsula were deposited under a broad range of environmental conditions from deep offshore-shelf to reef facies. Halysitid and auloporid tabulate corals occur in a number of facies and show a high degree of endemism.

Two species of Halysitidae and three species of Auloporida are found in these formations. Both halysitids have been previously described from this region. The auloporids include the new species Syringopora minuta and another species that may represent the first known Silurian occurrence of the fletcheriellid genus Pseudofletcheria. A neotype for the halysitid Cystihalysites amplitubulatus (Lambe) is proposed.

A CoCrFeNiMn high-entropy alloy (HEA), in the form of a face-centered cubic (fcc) solid solution, was processed by high-pressure torsion (HPT) to produce a nanocrystalline (nc) HEA. Significant grain refinement was achieved from the very early stage of HPT through 1/4 turn and an nc structure with an average grain size of ∼40 nm was successfully attained after 2 turns. The feasibility of significant microstructural changes was attributed to the occurrence of accelerated atomic diffusivity under the torsional stress during HPT. Nanoindentation experiments showed that the hardness increased significantly in the nc HEA during HPT processing and this was associated with additional grain refinement. The estimated values of the strain-rate sensitivity were maintained reasonably constant from the as-cast condition to the nc alloy after HPT through 2 turns, thereby demonstrating a preservation of plasticity in the HEA. In addition, a calculation of the activation volume suggested that the grain boundaries play an important role in the plastic deformation of the nc HEA where the flow mechanism is consistent with other nc metals. Transmission electron microscopy showed that, unlike conventional fcc nc metals, the nc HEA exhibits excellent microstructural stability under severe stress conditions.