91 research outputs found

    Exposures to Air Pollutants during Pregnancy and Preterm Delivery

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    The association between preterm delivery (PTD) and exposure to air pollutants has recently become a major concern. We investigated this relationship in Incheon, Republic of Korea, using spatial and temporal modeling to better infer individual exposures. The birth cohort consisted of 52,113 singleton births in 2001–2002, and data included residential address, gestational age, sex, birth date and order, and parental age and education. We used a geographic information system and kriging methods to construct spatial and temporal exposure models. Associations between exposure and PTD were evaluated using univariate and multivariate log-binomial regressions. Given the gestational age, birth date, and the mother’s residential address, we estimated each mother’s potential exposure to air pollutants during critical periods of the pregnancy. The adjusted risk ratios for PTD in the highest quartiles of the first trimester exposure were 1.26 [95% confidence interval (CI), 1.11–1.44] for carbon monoxide, 1.27 (95% CI, 1.04–1.56) for particulate matter with aerodynamic diameter ≤ 10 μm, 1.24 (95% CI, 1.09–1.41) for nitrogen dioxide, and 1.21 (95% CI, 1.04–1.42) for sulfur dioxide. The relationships between PTD and exposures to CO, NO(2), and SO(2) were dose dependent (p < 0.001, p < 0.02, p < 0.02, respectively). In addition, the results of our study indicated a significant association between air pollution and PTD during the third trimester of pregnancy. In conclusion, our study showed that relatively low concentrations of air pollution under current air quality standards during pregnancy may contribute to an increased risk of PTD. A biologic mechanism through increased prostaglandin levels that are triggered by inflammatory mediators during exposure periods is discussed

    The New Economy and New Business Models

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    This chapter tackles the definition of New Economy, its main elements and its transformation, a theoretical perspective, the economics of digital information; negligible marginal costs, network externalities and barriers and enablers of business model change. Digital Business Models; origins, concept, guidelines to develop a consensus for the business models and Digital Business Models best practices identified are also outlined. The chapter draws to a close with the key information regarding the main characteristics for E-Business Environment: generic e-Business Strategies, new Strategies for E-Organizations and new Digital Business Models for E-Organizations.2019-2

    Community-level characteristics and environmental factors of child respiratory illnesses in Southern Arizona

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    Abstract Background Lower respiratory illnesses (LRIs) and asthma are common diseases in children 0.05). Conclusions Our study revealed complex, multi-factorial associations between predictors and outcomes. Findings indicate that many rural areas with lower SES have distinct factors for childhood respiratory diseases that require further investigation. County-wide differences in maternal characteristics or agricultural land uses (not tested here) may also play a role in Pima County residence protecting against hospitalizations, when compared to Maricopa County. By better understanding this and other relationships, more focused public health interventions at the community level could be developed to reduce and better control these diseases in children <5 years, who are more physiologically vulnerable

    Health survey on workers and residents near the municipal waste and industrial waste incinerators in Korea

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    Hazardous substances, such as polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) also have been detected in Municipal Solid Waste (MSW) and industrial waste incinerators in Korea. In this study, we estimated the exposure status of these hazardous substances and their heath effects in workers and residents near the MSW incinerators and residents near the industrial waste incinerators. We interviewed 13 workers and 16 residents from the area around the two MSW incinerators, and further 10 residents from the area around one industrial waste incinerator, which is suspected to emit higher hazardous substances. During the interview we collected information including sociodemographic information, personal habits, work history, detailed gynecologic and other medical history. Blood samples from 45 subjects were also collected for analysis of PCDDs and PCDFs, which were analyzed by HRGC-HRMS (High Resolution Gas Chromatography - High Resolution Mass Spectrometers). In addition to a questionnaire survey, urinary concentrations of 8-hydroxydeoxyguanosine (8-OH-dG) and malondialdehyde (MDA) were measured as oxidative injury biomarkers. Urinary concentrations of 8-OH-dG were determined by in vitro ELISA (JAICA, Fukuroi, Japan). MDA were determined by HPLC using adduct with TBA (thiobarbituric acid). The PCDD/F concentrations in residents from the area around industrial waste incinerator were higher than those in workers and residents from the area around MSW incinerator. The average toxic equivalency (TEQ) concentrations of PCDD/Fs in residents from the area around industrial waste incinerator were 53.4 pg I-TEQs/g lipid. The average TEQ concentrations of PCDD/Fs in workers and residents near MSW incinerator were 12.2 pg I-TEQs/g lipid. Estimated daily intake (EDI) of each person was calculated, and the EDI of all workers and residents near MSW incinerator were within the tolerable daily intake range. But for only 30% of 10 people near the industrial waste incinerator were the EDI within the tolerable daily intake range (14 pg I-TEQ/kg bw/day) suggested by WHO (1997). The oxidative stress of residents near the industrial waste incinerator was higher than that in workers and residents from the area around MSW incinerator. This oxidative stress may have been caused by hazardous substances, such as PCDD/Fs emitted by incinerators. The residents from the area around industrial waste incinerator were exposed to hazardous substances such as PCDD/Fs. Proper protection strategies against these hazardous chemicals are needed.X1119sciescopu

    Strong instantaneous contribution in femtosecond degenerate four-wave mixing from 350 mu m InP due to virtual excitation

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    We have observed strong four-wave mixing (FWM) signals from the third up to the seventh order for a 350 mu m undoped InP at 10 K with an excitation at far below the band gap. The third order spectrally resolved FWM signal shifts continuously to blue as time delay moves away from positive to negative. The peak intensities of the third and fifth order time-integrated FWM signals decrease rapidly as the detuning increases, as (detuning)(-2) and (detuning)(-6), respectively. The FWM signal at far below the band gap is attributable to the strong instantaneous contribution of the excitation pulse

    Enhancement in the Modeling of Temperature and Strain Rate-Dependent Plastic Hardening Behavior of a Sheet Metal

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    In the present study, viscoplastic hardening behavior of aluminum alloy 3003 sheet was measured and existing hardening models were evaluated in terms of the accuracy for predicting strain rate and temperature-dependent flow behaviors. Moreover, a modified hardening model was proposed to capture the flow stress-strain responses under various strain rates and temperatures with enhanced accuracy. Mechanical responses of the material were measured by using uniaxial tensile test at various temperature (approximate to 25-250 degrees C) and strain rates (approximate to 0.001-0.3 s(-1)), and the split Hopkinson pressure bar (SHPB) test was also conducted to obtain flow behavior at the strain rate over 700 s(-1) at room temperature. Based on these experimental data, two well accepted viscoplastic constitutive models-Johnson-Cook and Khan-Huang-Liang-were evaluated. Finally, the Hollomon/Voce type model was further developed, which resulted in significant improvement in predicting the flow stress curves under wide range of strain rate and temperature.1121sciescopu

    Comorbidities in obstructive lung disease in Korea: data from the fourth and fifth Korean National Health and Nutrition Examination Survey

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    Hee Jin Park, Ah Young Leem, Sang Hoon Lee, Ju Han Song, Moo Suk Park, Young Sam Kim, Se Kyu Kim, Joon Chang, Kyung Soo Chung Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Severance Hospital, Institute of Chest Disease, Yonsei University College of Medicine, Seoul, South Korea Background: Comorbidities can occur frequently in patients with chronic obstructive pulmonary disease (COPD) and can influence mortality and morbidity independently. It is increasingly recognized that many patients with COPD have comorbidities that have a major impact on their quality of life and survival. Therefore, we investigated the prevalence of comorbidities in Korean COPD populations. Methods: We used data obtained in the 6 years of the fourth and fifth Korean National Health and Nutrition Examination Survey (KNHANES) IV and V. Among 50,405 subjects, 16,151 subjects aged &ge;40 years who performed spirometry adequately were included in this study. Airway obstruction was defined as forced expiratory volume in 1 second/forced vital capacity &lt;0.7, and the Global Initiative For Chronic Obstructive Lung Disease stage was used to evaluate the severity of airway obstruction. Statistical analyses were performed using SAS 9.2. Results: Among the 16,151 subjects (43.2% male, 56.8% female; mean age: 57.1 years for men and 57.2 years for women), 13.1% had obstructive lung function; 11.3%, restrictive lung function; and 75.6%, normal lung function. Among individuals with obstructive lung function, 45.3%, 49.4%, and 5.3% had mild, moderate, and severe and very severe airflow limitation. The prevalence of hypertension, diabetes mellitus (DM), underweight, and hypertriglyceridemia was higher in the obstructive lung function group than in the normal lung function group (49.6% vs 35.2%; 16.8% vs 10.5%; 3.3% vs 1.3%; 19.7% vs 17.0%). According to the severity of airway obstruction, hypertension and underweight were more common as severity increased, although the prevalence of DM and hypertriglyceridemia was lower in subjects with severe airway obstruction. The prevalence of hypercholesterolemia, overweight, and osteoarthritis was lower in the obstructive lung function group, especially in the severe airway obstruction groups. Conclusions: Overall, our analysis is similar to research that was conducted earlier. Our study showed that hypertension and underweight are common comorbidities in COPD patients, and are higher as the severity of airflow obstruction increased in both men and women. DM, hypertriglyceridemia, and low high-density lipoprotein cholesterol are more common in subjects with airway obstruction, although their incidence is lower in the severe group. Keywords: chronic obstructive pulmonary disease, comorbidity, hypertension, underweigh
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