Numerical investigation of the effect of air layer on drag reduction in channel flow over a superhydrophobic surface.

This study investigates the effects of an air layer on drag reduction and turbulence dynamics in channel flow over a superhydrophobic surface (SHS). Employing the OpenFOAM platform, direct numerical simulation was conducted to investigate turbulent channel flow with an air layer over an SHS. The simulations, which take into account the interaction between water and air, analyze various parameters such as velocity distribution, drag reduction (DR), Reynolds stress, turbulent kinetic energy (TKE), and coherent structures near the water-air interface. The presence of an air layer significantly alters the velocity distribution, leading to higher velocities at the interface compared to simulations without the air layer. Notably, the thickness of the air layer emerges as an important factor, with larger thicknesses resulting in increased velocities and drag reduction. This study underscores the substantial impact of the air layer on TKE near the superhydrophobic surface, emphasizing its role in understanding and optimizing drag reduction. Furthermore, the nonlinear relationship between slip velocity, Q contours, and coherent structures near the SHS are investigated.

Electrophysiological function in eyes with reticular pseudodrusen according to fundus distribution.

Reticular pseudodrusen (RPD) could be present not only in the posterior pole but extramacular area also as a confluent morphological pattern. Thus RPD can be classified by the fundus distribution for the assessment of visual prognosis. The electrophysiological function in eyes with reticular pseudodrusen (RPD), showing various fundus distribution were evaluated using full-field electroretinogram (ERG). Retinal distribution of RPD was divided into three types (localized, intermediate, and diffuse) according to the extent of involvement of retinal areas by fundus photograph montages. RPD were present with the diffuse type in 21 eyes (25.6%), with the intermediate type in 30 eyes (36.6%), and with the localized type in 31 eyes (37.8%). The average age was 74.76 ± 4.52 (range, 65-81) years in the diffuse type, 72.47 ± 9.13 (range, 55-91) years in the intermediate type, and 70.26 ± 7.77 (range, 61-89) years in the localized type. The mean amplitudes of the scotopic rod response, scotopic maximal combined response, oscillatory potentials (OP), photopic cone response, and 30Hz cone flicker response were more decreased in the diffuse, intermediate, and localized types in order, except for the photopic cone a-wave response. The diffuse type showed reduced amplitudes of ERG responses than the normal control group under all testing conditions except for the photopic a-wave response, and differences were statistically significant with the age restriction and adjustment methods (Bonferroni-corrected P < 0.05). The mean implicit times of ERG responses were significantly delayed in the diffuse type in the photopic b-wave. (Bonferroni-corrected P < 0.05). Extensive retinal involvement of RPD correlates with severely reduced electrophysiological retinal function. This acquired form of decreased electrophysiological function should be regarded as different from those of hereditary retinal degeneration.

Association Between Change in Serum Aminotransferase and Mortality: A Nationwide Cohort Study in Korea.

There is little information on how the change in serum aminotransferase affects mortality. We investigated the association between changes in serum aminotransferase levels and mortality from all causes, cardiovascular disease (CVD), and liver disease.Three percent of men from the Korean National Health Insurance database were sampled randomly at the end of 2002. After excluding patients with cancer, CVD, CVD risk factors, or liver disease, those who participated in 2 consecutive rounds of the national health screening examination were included (n = 68,431). The primary outcome was CVD mortality. Secondary outcomes were liver disease mortality and all-cause mortality. Change in metabolic profiles was analyzed based on changes in liver enzyme levels. Elevated levels of serum aminotransferase were associated with CVD, liver disease, and all-cause mortality. Men who had sustained elevation of serum aminotransferase during 2 subsequent liver enzyme tests showed a significantly higher risk of CVD mortality (adjusted hazard ratio [aHR] 1.95; 95% confidence interval [CI] 1.07-3.56, 2.29; 1.27-4.12) than the sustained normal group. In contrast, the normalization group (aHR 1.52, 95% CI 0.82-2.81 for aspartate aminotransferase [AST]; aHR 1.35, 95% CI 0.70-2.61 for alanine aminotransferase [ALT]) and the new elevation group (aHR 1.27, 0.66-2.44 for AST; aHR 0.99, 95% CI 0.49-2.20 for ALT) were not different from the sustained normal group in CVD mortality.Individuals with serum aminotransferase elevation, particularly when sustained, are at higher risk of mortality, and should receive appropriate medical attention.

Diabetes mellitus as an independent risk factor for lung cancer: a meta-analysis of observational studies.

BACKGROUND: Epidemiologic studies have demonstrated inconsistent associations between diabetes mellitus and the risk of lung cancer. To determine whether diabetes mellitus is associated with an increased risk of lung cancer, we performed a meta-analysis of observational studies. METHODS: PubMed, EMBASE and the Cochrane Library were searched for observational studies conducted prior to September 2012. We included prospective cohort studies that reported relative risks and case-control studies that showed odds ratios in the analysis. The pooled relative risk (RR) with 95% confidence intervals (CIs) was calculated with a random effects model. Sensitivity analysis was performed with studies which controlled for smoking status. Associations were assessed in several subgroups representing different participant and study characteristics. RESULTS: A total of 34 studies from 24 manuscripts (10 case-control studies and 24 cohort studies) were included in the analyses. Diabetes was significantly associated with the increased risk of lung cancer compared with non-diabetic controls when limiting the analysis to studies adjusting for smoking status (RR, 1.11; 95% CI, 1.02-1.20; I(2)=46.1%). By contrast, this association disappeared when the analysis was restricted to studies not adjusting for smoking status (RR, 0.99; 95% CI, 0.88-1.11; I(2)=96.7%). When stratifying by sex, an increased risk of lung cancer was prominent in diabetic women (RR, 1.14; 95% CI, 1.09-1.20; I(2)=0%), while there was no association in diabetic men (RR, 1.07; 95% CI, 0.89-1.28; I(2)=96.6%). Among diabetic women, significantly increased risks of lung cancer were found in the following subgroups: cohort studies (RR, 1.14; 95% CI, 1.08-1.20; I(2)=0%), studies controlling for major confounding variables such as age, smoking and alcohol (RR, 1.19; 95% CI, 1.00-1.43; I(2)=23.1%), studies with long-term follow-up (RR, 1.14; 95% CI, 1.08-1.20; I(2)=0%), and high-quality studies assessed by the Newcastle-Ottawa Scale (RR, 1.14; 95% CI, 1.08-1.20; I(2)=0%). INTERPRETATION: Preexisting diabetes mellitus may increase the risk of lung cancer, especially among female diabetic patients. Further large-scale prospective studies are needed to test specifically the effect of diabetes mellitus on lung cancer risk.

Educational Disparities in Distribution of Cardiovascular Risk Factors and Quality of Care in Korean Adults: Korean National Health and Nutrition Survey IV.

BACKGROUND: The purpose of this study was to investigate how educational status influences cardiovascular risk factors and care of diabetes mellitus and hypertension. METHODS: From Korean National Health and Nutrition Survey IV, we obtained survey results of 6,835 men and 9,067 women more than 30 years old. We performed multivariate logistic regression to compare cardiovascular risk factors and care of hypertension and diabetes respective to educational status. RESULTS: There were disparities in cardiovascular risk factors by educational status. In men, impaired fasting glucose, high triglyceride, and smoking were less frequently found in the highest educated group than in the middle educated group. In women, the prevalence of abdominal obesity, impaired fasting glucose, high blood pressure, high triglyceride, and metabolic syndrome among the highest educated group were significantly lower. The proportion of those with proper physical activity in the highest educated group was found to be less than that of the middle educated group, regardless of gender. For care of diabetes mellitus and hypertension, disease recognition and treatment were lower among the lowest educated group in men, while these disparities were not shown in women. Instead, the lowest educated group in diabetic women received screening exams for eye and kidney complications less than the middle education group. In both genders, the high education group had a higher chance of receiving education about diabetes mellitus. CONCLUSION: There were educational disparities in cardiovascular risk factors and care of hypertension and diabetes mellitus. The disparities were found to be different by gender.

Diabetes mellitus and ovarian cancer risk: a systematic review and meta-analysis of observational studies.

OBJECTIVE: The objective of this study was to evaluate the epidemiologic association between diabetes and risk of ovarian cancer. METHODS: We searched PubMed, EMBASE, and The Cochrane Library for observational studies on the association between diabetes and ovarian cancer. Cohort studies that reported relative risks (RRs) and case-control studies that showed odds ratios were included in the analysis. Summary RRs with 95% confidence intervals (CIs) were calculated with a random-effects model. RESULTS: A total of 19 studies from 18 articles (7 case-control studies and 11 cohort studies) met the inclusion criteria. Combining data from all studies, diabetes was associated with an increased risk of ovarian cancer, compared with no diabetes (summary RR of ovarian cancer incidence, 1.17; 95% CI, 1.02-1.33). In cohort and nested case-control studies, patients with diabetes had statistically significant increased risk of ovarian cancer (RR, 1.16; 95% CI, 1.01-1.33), without significant heterogeneity (I = 27; P = 0.172). Among studies that control for age, body mass index, smoking, and alcohol, a prominent association between diabetes and ovarian cancer was found (RR, 1.55; 95% CI, 1.11-2.19). CONCLUSIONS: This study suggests that women with diabetes have a moderately increased risk of ovarian cancer.

Dynamic contrast-enhanced MRI for assessing therapeutic response of choroidal neovascularization in a rat model.

PURPOSE: We evaluated the potential of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) as a noninvasive biomarker of choroidal neovascularization (CNV) and its utility as a tool for monitoring therapeutic response in laser-induced rat CNV models. METHODS: CNV was induced in the right eyes of 14 rats using a laser. Rats (n = 7) were treated daily for 14 days with a candidate drug (KR-31831, 50 mg/kg of body weight) having antiangiogenic effects, whereas control rats (n = 7) were treated with the vehicle alone (10% cremophor, 10% absolute ethyl alcohol, and 80% saline). DCE-MRI examinations were performed on the day before surgery (D - 1), and 3, 7, and 14 days after surgery (D + 3, D + 7, and D + 14), from which pharmacokinetic parameters (K(trans), v(e), v(p)) were calculated. Angiography was performed to visualize CNV using FITC-labeled high molecular weight dextran after MRI on D + 14. The paired Wilcoxon test and Mann-Whitney U test were performed for statistical analysis. RESULTS: The K(trans) and v(e) values of the CNV-induced right eyes were significantly higher than those of the intact eyes in control rats at D + 14 (P < 0.05). In the CNV-induced eyes, the relative K(trans) and v(e) values of the KR-31831-treated group were significantly lower than those of the nontreated group at D + 14 (P < 0.05). The angiography showed that decreased CNV was observed in rats treated with KR-31831. CONCLUSIONS: Quantitative DCE-MRI produces noninvasive biomarker of CNV, thus allowing monitoring of therapeutic response of antiangiogenic drugs in neovascular age-related macular degeneration (AMD).

Clinical features of reticular pseudodrusen according to the fundus distribution.

BACKGROUND: To evaluate the morphological features and prevalence of accompanying late age-related macular degeneration (AMD) according to the fundus distribution of reticular pseudodrusen (RPD). METHODS: According to the involved area in the fundus, the distribution of RPD was classified as localised, intermediate, or diffuse type. Morphology of RPD was classified as discrete, branching, or confluent pattern. The presence of late AMD was evaluated. RESULTS: 233 eyes of 121 patients with RPD were included. The distribution of RPD was localised, intermediate and diffuse type in 30.9%, 40.3% and 28.8% of eyes, respectively. The discrete, branching and confluent morphological patterns were found in 45.8%, 44.8% and 9.7% of the localised type, and in 0%, 13.8% and 86.2% of the intermediate type, respectively. In contrast, the diffuse type showed only the confluent morphological pattern. The prevalence of accompanying late AMD was 13.9%, 13.8% and 56.7% in the localised, intermediate and diffuse type, respectively, and it was significantly higher in the diffuse type (p<0.05). CONCLUSION: RPD with diffuse distribution showed a confluent morphological pattern and a high prevalence of late AMD. RPD can be classified by the fundus distribution for the assessment of visual prognosis.

Clinical characteristics of reticular pseudodrusen in Korean patients.

PURPOSE: To clarify the clinical characteristics of reticular pseudodrusen in Korean patients. DESIGN: Retrospective, observational, consecutive case series. METHODS: A total of 255 eyes of 130 patients diagnosed with reticular pseudodrusen were evaluated. Reticular pseudodrusen were diagnosed by characteristic fundus findings using ophthalmoscopy, color fundus photography with blue-channel examination, near-infrared photography, red-free photography, autofluorescence imaging, fluorescein angiography, indocyanine green angiography, and spectral-domain optical coherence tomography. Age-related macular degeneration (AMD) was determined by the International Classification and Grading System. RESULTS: The mean age was 72.6 ± 9.0 years (range, 43 to 92 years). Most reticular pseudodrusen patients had bilateral disease (97.7%), with a female preponderance (86.2%). All 3 patients who showed unilateral reticular pseudodrusen had neovascular AMD in the eye with no reticular pseudodrusen. AMD was found in 183 eyes (71.8 %), among which early AMD was found in 115 eyes (45.1%), geographic atrophy was found in 41 eyes (16.1%), and neovascular AMD was found in 27 eyes (10.6%). The mean age of patients with AMD and with no AMD was 73.7 ± 9.2 years (range, 58 to 92 years) and 69.9 ± 11.7 years (range, 43 to 90 years), respectively, and there was a statistical difference between these 2 groups (P < .05). Classic choroidal neovascularization was found in 13 eyes (48.1%), and occult choroidal neovascularization was found in 14 eyes (51.9%) in the neovascular AMD group. CONCLUSIONS: Reticular pseudodrusen occurs in Koreans, and clinical manifestations of reticular pseudodrusen in Koreans did not differ significantly from those described in white persons. However, our study demonstrated a higher rate of bilaterality compared with those previously reported, and geographic atrophy was found to be associated more commonly with reticular pseudodrusen than with neovascular AMD. Ethnical differences may be associated with these findings, and further studies are required.