Association between periodontitis and hemorrhagic stroke among Koreans: A case-control study

Background: Several studies suggested that periodontitis is a risk factor for stroke, but the relationship between periodontitis and hemorrhagic stroke has not been widely reported. This study aims to evaluate the association between periodontitis and hemorrhagic stroke and to identify the risk group for this association. Methods: We recruited 165 patients who were diagnosed via computed tomography brain imaging as having had a hemorrhagic stroke and 214 non-stroke control subjects for a case-control study. All participants underwent a clinical periodontal examination using clinical attachment level (CAL) as amarker. Information about sociodemographic factors, behavioral factors, systemic health, and a familial history of systemic health was gathered through an interview using structured questionnaires. The association between periodontitis and hemorrhagic stroke was evaluated using multivariate logistic regression analyses with adjustment for age, gender, income, education, hypertension, diabetes, body mass index, cardiac disease, familial hypertension history, familial diabetes history, familial cardiac disease history, smoking, and alcohol consumption. Subgroup analyses were also performed to investigate potential risk groups. Results: After controlling for potential confounders, periodontitis (CAL ≥6 mm) was found to be significantly associated with hemorrhagic stroke (odds ratio: 2.5; 95% confidence interval: 1.1 to 5.6), but this association did not exhibit a dose-dependent response for periodontitis (percentile of sites of periodontal pockets with CAL ≥5 mm among total probed pockets). The association between periodontitis (CAL ≥6 mm) and hemorrhagic stroke was significant for males, patients who had a lower income than control subjects, obese patients, and patients without diabetes. Conclusions: Periodontitis may be an independent risk factor for hemorrhagic stroke. Risk groups include males, patients without diabetes, and obese subjects

Why Are Outcomes Different for Registry Patients Enrolled Prospectively and Retrospectively? Insights from the Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF).

Background: Retrospective and prospective observational studies are designed to reflect real-world evidence on clinical practice, but can yield conflicting results. The GARFIELD-AF Registry includes both methods of enrolment and allows analysis of differences in patient characteristics and outcomes that may result. Methods and Results: Patients with atrial fibrillation (AF) and ≥1 risk factor for stroke at diagnosis of AF were recruited either retrospectively (n = 5069) or prospectively (n = 5501) from 19 countries and then followed prospectively. The retrospectively enrolled cohort comprised patients with established AF (for a least 6, and up to 24 months before enrolment), who were identified retrospectively (and baseline and partial follow-up data were collected from the emedical records) and then followed prospectively between 0-18 months (such that the total time of follow-up was 24 months; data collection Dec-2009 and Oct-2010). In the prospectively enrolled cohort, patients with newly diagnosed AF (≤6 weeks after diagnosis) were recruited between Mar-2010 and Oct-2011 and were followed for 24 months after enrolment. Differences between the cohorts were observed in clinical characteristics, including type of AF, stroke prevention strategies, and event rates. More patients in the retrospectively identified cohort received vitamin K antagonists (62.1% vs. 53.2%) and fewer received non-vitamin K oral anticoagulants (1.8% vs . 4.2%). All-cause mortality rates per 100 person-years during the prospective follow-up (starting the first study visit up to 1 year) were significantly lower in the retrospective than prospectively identified cohort (3.04 [95% CI 2.51 to 3.67] vs . 4.05 [95% CI 3.53 to 4.63]; p = 0.016). Conclusions: Interpretations of data from registries that aim to evaluate the characteristics and outcomes of patients with AF must take account of differences in registry design and the impact of recall bias and survivorship bias that is incurred with retrospective enrolment. Clinical Trial Registration: - URL: http://www.clinicaltrials.gov . Unique identifier for GARFIELD-AF (NCT01090362)

Risk profiles and one-year outcomes of patients with newly diagnosed atrial fibrillation in India: Insights from the GARFIELD-AF Registry.

BACKGROUND: The Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF) is an ongoing prospective noninterventional registry, which is providing important information on the baseline characteristics, treatment patterns, and 1-year outcomes in patients with newly diagnosed non-valvular atrial fibrillation (NVAF). This report describes data from Indian patients recruited in this registry. METHODS AND RESULTS: A total of 52,014 patients with newly diagnosed AF were enrolled globally; of these, 1388 patients were recruited from 26 sites within India (2012-2016). In India, the mean age was 65.8 years at diagnosis of NVAF. Hypertension was the most prevalent risk factor for AF, present in 68.5% of patients from India and in 76.3% of patients globally (P < 0.001). Diabetes and coronary artery disease (CAD) were prevalent in 36.2% and 28.1% of patients as compared with global prevalence of 22.2% and 21.6%, respectively (P < 0.001 for both). Antiplatelet therapy was the most common antithrombotic treatment in India. With increasing stroke risk, however, patients were more likely to receive oral anticoagulant therapy [mainly vitamin K antagonist (VKA)], but average international normalized ratio (INR) was lower among Indian patients [median INR value 1.6 (interquartile range {IQR}: 1.3-2.3) versus 2.3 (IQR 1.8-2.8) (P < 0.001)]. Compared with other countries, patients from India had markedly higher rates of all-cause mortality [7.68 per 100 person-years (95% confidence interval 6.32-9.35) vs 4.34 (4.16-4.53), P < 0.0001], while rates of stroke/systemic embolism and major bleeding were lower after 1 year of follow-up. CONCLUSION: Compared to previously published registries from India, the GARFIELD-AF registry describes clinical profiles and outcomes in Indian patients with AF of a different etiology. The registry data show that compared to the rest of the world, Indian AF patients are younger in age and have more diabetes and CAD. Patients with a higher stroke risk are more likely to receive anticoagulation therapy with VKA but are underdosed compared with the global average in the GARFIELD-AF. CLINICAL TRIAL REGISTRATION-URL: http://www.clinicaltrials.gov. Unique identifier: NCT01090362

Air Pollution as a Risk Indicator for Periodontitis

Background: Air pollutants can influence local and systemic inflammation, oxidative stress and microbiome composition. Therefore, air pollution may potentially represent an unexplored modifiable risk indicator for periodontitis. The aim of the current cross-sectional study was to investigate the epidemiological association between outdoor air pollution and periodontitis in a representative sample of the South Korean population. Methods: A total of 42,020 individuals, which were representative of 35.2 million South Koreans, were examined. The mean annual levels of particulate matter of 10 μm (PM10), ozone, sulfur dioxide (SO2), nitrogen dioxide (NO2) and humidity, were studied. Periodontitis was defined according to the Community Periodontal Index (CPI ≥ 3). Simple and multiple regression analyses using four different models were applied. Results: Every 5-μg/m3 increase in PM10 (OR = 1.17; 95% confidence interval—CI: 1.11–1.24) and of 0.005 ppm in ozone levels (OR = 1.4; 95% CI: 1.00–1.30) were positively associated with periodontitis prevalence. Conversely, every 5% increase in humidity (OR = 0.94; 95% CI: 0.90–0.99) and 0.003 ppm increase in NO2 levels (OR = 0.93; 95% CI: 0.89–0.96) were inversely associated with periodontitis occurrence. Conclusions: In this nationally representative population several air pollutants were found to be associated with periodontitis occurrence. Hence, the present results suggest that air pollution may be a new modifiable risk indicator for periodontitis

Fault Location Method Using Phasor Measurement Units and Short Circuit Analysis for Power Distribution Networks

This paper proposes a fault location method for power distribution networks using phasor measurement units (PMU) and short circuit analysis. In order to improve the problems of the existing studies, we focused on several approaches as follows. First, in order to minimize the number of PMU installations, a fault location estimation of lateral feeders through short circuit analysis was presented. Second, unbalanced faults and impacts of photovoltaic (PV) were considered. The proposed method consists of two stages. In Stage 1, the fault location was estimated for the main feeder using PMU installed at the start and end points of the main feeder. Symmetrical components of voltage and current variation were calculated by considering the impact of PVs interconnected to the lateral feeders. If the result of Stage 1 indicated a connection section of lateral feeder on the main feeder, Stage 2 would be performed. In Stage 2, the fault location was estimated for the lateral feeder by comparing the results of the short circuit analysis and measurements of PMUs. The short circuit analysis was based on an unbalanced power flow that considered dynamic characteristics of the PV inverter. The proposed method was verified through various fault situations in a test system. For the applicability of the proposed algorithm to the actual system, a noise test was also performed

Searching for an ideal cervical cancer screening model to reduce false-negative errors in a country with high prevalence of cervical cancer

The purpose of this study was to develop an ideal cervical cancer screening model to reduce false-negative errors in Korea where there is a high prevalence of cervical cancer. We conducted a cross-sectional study including 33,531 women who underwent routine cervical cancer screening in Korea. Colposcopic examinations were performed after abnormal results on their screening tests. Diagnostic capacities including sensitivity, specificity, and false-negative rate of each screening scenario were analysed at the CIN1 or worse (CIN1+) threshold with colposcopic biopsy results considered the gold standard. A total of 4117 women had valid results for Papanicolaou (Pap) cytology, human papilloma virus (HPV) tests, cervicography, and colposcopically directed biopsy were included in this study. The disease prevalence of CIN1+ was 38.1%. Pap-alone resulted in the highest false-negative rate of 46.9%, followed by HPV-alone at 25.1%, cervicography-alone at 18.7%, Pap/HPV-combined at 15.0%, Pap/cervicography-combined at 6.9% and Pap/HPV/cervicography-combined at 2.9% in a sample of 1570 women with CIN1+ lesions. Therefore, cervicography demonstrated excellent performance for the detection of CIN or cervical cancer and markedly reduced false-negative errors when used in combination with Pap cytology and HPV tests.IMPACT STATEMENT What is already known on this subject? False-negative rate of Pap smears is as high as approximately 40–50%. Limitations of the Papanicolaou (Pap) test have led to the development of new screening programmes for cervical cancer, such as combination screenings with human papillomavirus (HPV) tests or cervicography. What do the results of this study add? Pap-alone resulted in the highest false-negative rate of 46.9%, followed by HPV-alone at 25.1%, cervicography-alone at 18.7%, Pap/HPV-combined at 15.0%, Pap/cervicography-combined at 6.9% and Pap/HPV/cervicography-combined at 2.9% in a sample of 1570 women with CIN1+ lesions. What are the implications of these findings for clinical practice and/or further research? Cervicography demonstrated excellent performance for the detection of CIN or cervical cancer and markedly reduced false negative errors when used in combination with Pap cytology and HPV tests

Improvement in Energy Conversion Efficiency by Modification of Photon Distribution within the Photoanode of Dye-Sensitized Solar Cells

The dye-sensitized solar cell (DSSC) is a potential alternative to the widely used Si-based solar cell, with several advantages including higher energy conversion efficiency under weak and indirect illumination conditions, and the possibility of practical application in urban life due to their exterior characteristics. However, despite these advantages, the energy conversion efficiency of DSSCs has remained low at ∼10%. To improve the efficiency of DSSCs, research has been done on modifying the materials used in DSSC component parts, such as the photoanode, electrolyte, and counter electrode. Another approach is to modify the photoanode to increase the diffusion coefficient, reduce the recombination rate, and enhance the light behavior. One of the most popular methods for improving the efficiency of DSSCs is by trapping and dispersing the incident light using a scattering layer. Use of a scattering layer has shown various and interesting results, depending on the application, but it is currently used only in a simple form and there has been no deep research on the further potential of the scattering layer. In this study, the scattering center was introduced to maximize the effect of scattering. Light distribution near the scattering center, within or on the photoanode, was investigated using finite differential time domain (FDTD) numerical methods. Based on the FDTD analysis, an optimized, dome-shaped three-dimensional modified structure of a transparent photoanode with minimized scattering centers was introduced and indicated the possibility of modifying the photon distribution in the photoanode to enhance the performance of DSSCs. In addition to using the scattering center, we have introduced the structure of the dome-shaped three-dimensional structure to utilize the light distribution within the photoanode. This novel three-dimensional transparent photoanode and scattering center design increased the energy conversion efficiency of DSSCs from 6.3 to 7.2%. These results provide a foundation for investigating the role of the scattering center via further in-depth research. This new three-dimensional photoanode design provides a means to overcome the previous limitations on DSSC performance