LitSearch-NOx (2024)

Project ID

4767

Category

NAAQS

Added on

April 12, 2023, 4:32 a.m.

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Journal Article

Abstract  OBJECTIVE: This study aimed to demonstrate whether pretreatment with nitric oxide (NO) loaded into echogenic immunoliposomes (ELIP) plus ultrasound, applied before injection of molecularly targeted ELIP can promote penetration of the targeted contrast agent and improve visualization of atheroma components.

METHODS: ELIP were prepared using the pressurization-freeze method. Atherosclerosis was induced in Yucatan miniswine by balloon denudation and a hyperlipidemic diet. The animals were randomized to receive anti-intercellular adhesion molecule-1 (ICAM-1) ELIP or immunoglobulin (IgG)-ELIP, and were subdivided to receive pretreatment with standard ELIP plus ultrasound, NO-loaded ELIP, or NO-loaded ELIP plus ultrasound. Intravascular ultrasound (IVUS) data were collected before and after treatment.

RESULTS: Pretreatment with standard ELIP plus ultrasound or NO-loaded ELIP without ultrasound resulted in 9.2 ± 0.7% and 9.2 ± 0.8% increase in mean gray scale values, respectively, compared to baseline (p < 0.001 vs. control). Pretreatment with NO-loaded ELIP plus ultrasound activation resulted in a further increase in highlighting with a change in mean gray scale value to 14.7 ± 1.0% compared to baseline (p < 0.001 vs. control). These differences were best appreciated when acoustic backscatter data values (RF signal) were used [22.7 ± 2.0% and 22.4 ± 2.2% increase in RF signals for pretreatment with standard ELIP plus ultrasound and NO-loaded ELIP without ultrasound respectively (p < 0.001 vs. control), and 40.0 ± 2.9% increase in RF signal for pretreatment with NO-loaded ELIP plus ultrasound (p < 0.001 vs. control)].

CONCLUSION: NO-loaded ELIP plus ultrasound activation can facilitate anti-ICAM-1 conjugated ELIP delivery to inflammatory components in the arterial wall. This NO pretreatment strategy has potential to improve targeted molecular imaging of atheroma for eventual true tailored and personalized management of cardiovascular diseases.

Journal Article

Abstract  Carbon nanomaterials, including fullerenes, exhibit not only unique structure and electronic properties but also a significant potential to serve as radical scavengers and/or anti-oxidants. Their conjugation with anticancer drugs such as doxorubicin (DOX) may help to balance severe negative side effects of these cytostatics and also improve the delivery of the drug taking advantage of the enhanced cellular uptake, selectivity to cancer cells, and pH regulated release. In this study, the fullerene (C60) surface was oxidized by concentrated nitric acid, which enabled simple DOX-fullerene conjugation based on π-π stacking and hydrophilic interactions with carboxylic groups. The strength of this noncovalent binding is pH dependent. At a low pH, the amino group of DOX is protonated, however at a higher pH, the amino group is deprotonated, resulting in stronger hydrophobic interactions with the fullerene walls. CE and HPLC were employed for characterization of resulting complexes. The cell toxicity of the conjugates was evaluated using Staphylococcus aureus and finally they were administered into the chicken embryo to assess the applicability for in vivo imaging.

Journal Article

Abstract  BACKGROUND: Short message service (SMS) has been suggested as an effective method to improve adherence to medical therapy in some chronic diseases. However, data on the effects of SMS interventions to allergic rhinitis (AR) treatment is limited at present. We aimed to assess whether a daily SMS reminder could improve AR patients' adherence to medication and treatment outcomes.

METHODS: Fifty outpatients with AR were randomized to either receive (SMS group) or not (control group) a daily SMS reminder on their cell phone to take intranasal corticosteroid treatment for 30 days. The primary study outcomes were self-reported adherence to medication, clinic attendance rate, and severity of AR symptoms using a visual analogue scale (VAS). Secondary outcomes were changes in nasal patency (minimum cross-sectional area, nasal cavity volume, and nasal airway resistance) and exhaled nasal nitric oxide levels.

RESULTS: Self-reported adherence to medication in the SMS group (15/25, 60%), was significantly higher than in the control group (7/25, 28%, p = 0.02). Similarly, the clinic attendance rate in the SMS group (72%) was significantly higher than in the control group (40%, p = 0.02). Although the VAS score improved significantly from baseline in both study groups, the improvement in the SMS group was significantly greater than in the control group (4.38 ± 4.38 vs. 8.74 ± 6.54, p = 0.031). No significant differences were observed between the two groups for the secondary outcomes.

CONCLUSIONS: A daily SMS reminder may be an effective intervention to improve adherence to medication and treatment outcomes in AR patients.

Journal Article

Abstract  BACKGROUND: Elevated levels of particulate matter PM2.5 and rhinovirus infection have been known to exacerbate asthma. However, the combined effect of rhinovirus infection and high PM2.5 has not been investigated.

PURPOSE: To investigate the effect of PM2.5 and concomitant rhinovirus infection on airway function in asthma in an area with high PM2.5 concentration.

METHODS: Asthmatics and their matched controls were monitored for lung function, exhaled nitric oxide (eNO) and respiratory symptoms on days with varying levels of PM2.5. As the study was a repeated measure design, repeated clinical findings, and laboratory data were used in the mixed model analysis.

RESULTS: Wheezing and dyspnea in asthmatics were worsened with increasing ambient PM2.5. Increasing PM2.5 decreased FEV1% predicted (-0.51, -0.79 to -0.23) and FEF25-75% predicted (-0.66, -1.07 to -0.24) in subjects with asthma (all P < .01). Rhino viral infection reduced FEF25-75% predicted in subjects with asthma (-11.7, -20 to -2.9). The reductions in FEV25-75 and FEV1 per 10 μg/m(3) increase in ambient PM2.5 were 6% and 5% respectively. A significant interaction was observed between presence of rhinovirus infection and elevated PM2.5 in asthmatics causing a 4-fold decrease in FEF25-75 (P = .01) and a 2-fold decrease in FEV1% predicted values (P = .01) compared with asthmatics with no rhino viral infection.

CONCLUSIONS: Increasing ambient PM2.5 and low temperature independently worsened airway function in asthma. The interaction between rhinovirus and PM2.5 significantly impairs airway function in asthma. A larger sample size study is suggested to investigate these observations.

Journal Article

Abstract  Au@Cu2O core-shell nanoparticles (NPs) were synthesized by a solution method at room temperature and applied for gas sensor applications. Transmission electron microscopy (TEM) images showed the formation of Au@Cu2O core-shell NPs, where 12-15 nm Au NPs were covered with 60-30 nm Cu2O shell layers. The surface plasmon resonance (SPR) peak of Au NPs was red-shifted (520-598 nm) after Cu2O shell formation. The response of Au@Cu2O core-shell NPs was higher than that of bare Cu2O NPs to CO at different temperatures and concentrations. Similarly, the response of Au@Cu2O core-shell NPs was higher than that of bare Cu2O NPs for NO2 gas at low temperature. The improved performance of Au@Cu2O core-shell NPs was attributed to the pronounced electronic sensitization, high thermal stability and low screening effect of Au NPs.

Journal Article

Abstract  Solution behavior of lomefloxacin (lmx) complexes with copper(II) in the presence and absence of 1,10-phenanthroline (phen) was studied in aqueous solution, by potentiometry. The results obtained showed that under physiological conditions (micromolar concentration range and pH7.4) only copper(II):lmx:phen ternary complexes are stable. Hence, a novel copper(II) ternary complex of lomefloxacin with the nitrogen donor heterocyclic ligand phen was synthesized and characterized by means of UV-visible and IR spectroscopy, elemental analysis and X-ray crystallography. In the synthesized complex (1), [Cu(lmx)(phen)(NO3)]·5H2O, lmx acts as a bidentate ligand coordinating the metal cation, in its anionic form, through the carbonyl and carboxyl oxygens and phen coordinates through two N-atoms forming the equatorial plane of a distorted square-pyramidal geometry. The fifth ligand of the penta-coordinated Cu(II) center is occupied axially by an oxygen atom from the nitrate ion. Minimum inhibitory concentration (MIC) determinations of the complex and comparison with free lomefloxacin in various E. coli strains indicated that the Cu-complex is an antimicrobial which is as efficient as the free antibiotic but strongly suggest that the cell intake route of both species is different. Moreover, spectrophotometric stability studies suggest that the solution of the complex synthesized is considerably more photostable than the free fluoroquinolone supporting, therefore, the complex's suitability as a candidate for further biological testing in fluoroquinolone-resistant microorganisms with possible reduced side-effects.

Journal Article

Abstract  The printed circuit board (PCB) is an important part of electrical and electronic equipment, and its disposal and the recovery of useful materials from waste PCBs (WPCBs) are key issues for waste electrical and electronic equipment. Waste PCB compositions and their pyrolysis characteristics were analyzed in this study. In addition, the volatile organic compound (VOC) exhaust was controlled by an iron-impregnated alumina oxide catalyst. Results indicated that carbon and oxygen were the dominant components (hundreds mg/g) of the raw materials, and other elements such as nitrogen, bromine, and copper were several decades mg/g. Exhaust constituents of CO, H2, CH4, CO2, and NOx, were 60-115, 0.4-4.0, 1.1-10, 30-95, and 0-0.7mg/g, corresponding to temperatures ranging from 200 to 500°C. When the pyrolysis temperature was lower than 300°C, aromatics and paraffins were the major species, contributing 90% of ozone precursor VOCs, and an increase in the pyrolysis temperature corresponded to a decrease in the fraction of aromatic emission factors. Methanol, ethylacetate, acetone, dichloromethane, tetrachloromethane and acrylonitrile were the main species of oxygenated and chlorinated VOCs. The emission factors of some brominated compounds, i.e., bromoform, bromophenol, and dibromophenol, were higher at temperatures over 400°C. When VOC exhaust was flowed through the bed of Fe-impregnated Al2O3, the emission of ozone precursor VOCs could be reduced by 70-80%.

Journal Article

Abstract  The cloud point extraction (CPE) of uranyl ions by different kinds of extractants in Triton X-114 (TX-114) micellar solution was investigated upon the addition of ionic liquids (ILs) with various anions, i.e., bromide (Br(-)), tetrafluoroborate (BF4(-)), hexafluorophosphate (PF6(-)) and bis[(trifluoromethyl)sulfonyl]imide (NTf2(-)). A significant increase of the extraction efficiency was found on the addition of NTf2(-) based ILs when using neutral extractant tri-octylphosphine oxide (TOPO), and the extraction efficiency kept high at both nearly neutral and high acidity. However, the CPE with acidic extractants, e.g., bis(2-ethylhexyl) phosphoric acid (HDEHP) and 8-hydroxyquinoline (8-HQ) which are only effective at nearly neutral condition, was not improved by ILs. The results of zeta potential and (19)F NMR measurements indicated that the anion NTf2(-) penetrated into the TX-114 micelles and was enriched in the surfactant-rich phase during the CPE process. Meanwhile, NTf2(-) may act as a counterion in the CPE of UO2(2+) by TOPO. Furthermore, the addition of IL increased the separation factor of UO2(2+) and La(3+), which implied that in the micelle TOPO, NTf2(-) and NO3(-) established a soft template for UO2(2+). Therefore, the combination of CPE and IL provided a supramolecular recognition to concentrate UO2(2+) efficiently and selectively.

Journal Article

Abstract  OBJECTIVES: Otitis media is one of the most common diseases in pediatric populations. Recent research on its pathogenesis has focused on air pollution. Chronic exposure to particulate air pollution is associated with the impairment of middle ear function. However, the mechanisms and the underlying inhibitory pathways, especially in the human middle ear, remain unknown. Caffeic acid phenethyl ester (CAPE) is a biologically active ingredient of propolis, a product of honeybee hives, which has anti-oxidative and anti-inflammatory activities. The aim of this study was to evaluate the inhibitory effect of CAPE on diesel exhaust particle (DEP)-induced inflammation of human middle ear epithelial cells and to determine the underlying pathway of the action of CAPE.

METHODS: The inflammatory damage caused by DEPs and the anti-inflammatory effects of CAPE were determined by measuring the levels of tumor necrosis factor alpha and nicotinamide adenine dinucleotide phosphate oxidase (NOX) 4 with real-time reverse transcription polymerase chain reaction and Western blot analysis. The oxidative stress induced by DEPs and the anti-oxidative effects of CAPE were directly evaluated by measuring reactive oxygen species production by use of flow cytometric analysis of 2',7'-dichlorofluorescein diacetate. The effects of CAPE were compared with those of N-acetyl-L-cysteine, which has anti-oxidative and anti-inflammatory effects.

RESULTS: Use of CAPE significantly inhibited DEP-induced up-regulation of tumor necrosis factor alpha and NOX4 expression in a dose- and time-dependent manner. The accumulation of reactive oxygen species induced by DEPs was decreased by pretreatment with CAPE. The anti-inflammatory and anti-oxidative effects of CAPE were similar to those of N-acetyl-L-cysteine.

CONCLUSIONS: The inflammation induced by DEP is reduced by CAPE via the inhibition of NOX4 expression. These findings suggest that CAPE might be used as a therapeutic agent against DEP-induced inflammation of human middle ear epithelial cells.

Journal Article

Abstract  The Geospatial Determinants of Health Outcomes Consortium (GeoDHOC) study investigated ambient air quality across the international border between Detroit, Michigan, USA and Windsor, Ontario, Canada and its association with acute asthma events in 5- to 89-year-old residents of these cities. NO2, SO2, and volatile organic compounds (VOCs) were measured at 100 sites, and particulate matter (PM) and polycyclic aromatic hydrocarbons (PAHs) at 50 sites during two 2-week sampling periods in 2008 and 2009. Acute asthma event rates across neighborhoods in each city were calculated using emergency room visits and hospitalizations and standardized to the overall age and gender distribution of the population in the two cities combined. Results demonstrate that intra-urban air quality variations are related to adverse respiratory events in both cities. Annual 2008 asthma rates exhibited statistically significant positive correlations with total VOCs and total benzene, toluene, ethylbenzene and xylene (BTEX) at 5-digit zip code scale spatial resolution in Detroit. In Windsor, NO2, VOCs, and PM10 concentrations correlated positively with 2008 asthma rates at a similar 3-digit postal forward sortation area scale. The study is limited by its coarse temporal resolution (comparing relatively short term air quality measurements to annual asthma health data) and interpretation of findings is complicated by contrasts in population demographics and health-care delivery systems in Detroit and Windsor.Journal of Exposure Science and Environmental Epidemiology advance online publication, 13 November 2013; doi:10.1038/jes.2013.78.

Journal Article

Abstract  ABSTRACT While evidence suggests associations between maternal exposure to air pollution and adverse birth outcomes, pregnant women's exposure to household air pollution in developing countries is understudied. Personal exposures of pregnant women (n = 100) in Trujillo, Peru to air pollutants and their indoor concentrations were measured. The effects of stove-use related characteristics and ambient air pollution on exposure were determined using mixed-effects models. Significant differences in 48-hr kitchen concentrations of particulate matter (PM2.5), carbon monoxide (CO), and nitrogen dioxide (NO2) concentrations were observed across fuel-types (p < 0.05). Geometric mean PM2.5 concentrations were 112 μg/m (3) (CLs: 52, 242 μg/m(3)) and 42 μg/m(3) (21, 82 μg/m(3)) in homes were wood and gas were used respectively. PM2.5 exposure was at levels which recent exposure-response analyses suggest may not result in substantial reduction in health risks even in homes where cleaner burning gas stoves were used.

Journal Article

Abstract  Abstract Context: Tuberculosis (TB) is a chronic infectious disease with increasing incidence of drug resistance. Oral treatment for TB and multidrug resistance (MDR)-TB can have serious side effects. The causative agent of TB, Mycobacterium tuberculosis, resides in alveolar macrophages (AM). Pulmonary administration of anti-TB drugs can help in delivery of high concentration to AM. The ability of AM to phagocytose can also be utilized to generate mycobactericidal nitric oxide (NO) to improve efficacy of anti-TB drugs. Objective: To compare the uptake of rifampicin (RIF) by AM post oral and pulmonary administration of RIF microparticles (RM) and to compare hepatotoxicity and phagocytosis activity. Materials and Methods: RM were produced by spray drying process. RM were administered to rats through oral as well as intratracheal route. The uptake of RIF by AM and liver was measured. NO was measured in bronchoalveolar lavage (BAL) fluid. SGOT and SGPT levels were measured in serum. Results: Significantly higher (p < 0.05) concentration of RIF was found in AM post intratracheal administration. NO production was also significantly higher but less than toxic level. SGOT and SGPT levels as well as uptake of RIF by liver were indicative of no hepatotoxicity post intratracheal administration. Discussion: Phagocytosis of RM post intratracheal administration leads to significantly higher drug level in AM as well as production of significantly higher levels of NO. Conclusion: The administration of RM as dry powder inhalation (DPI) formulation may reduce treatment time of TB and chances of drug resistance TB.

Journal Article

Abstract  OBJECTIVES: Mustard is highly toxic to the lung. Its toxic effects are associated with inflammatory cell accumulation and increased pro-inflammatory cytokines as well as reactive oxygen and nitrogen species. In this study, we aimed to investigate the efficiency of melatonin (MEL) and S-methylisothiourea (SMT) on mechlorethamine (MEC) induced lung toxicity.

METHODS: Thirty-six male rats were randomly divided into four groups: control, MEC, MEC+MEL, and MEC+SMT. Control group was given saline only via transdermal route. Other groups were exposured to a single dose of MEC (3.5 mg/kg) via transdermal route. MEL (100 mg/kg) was administered intraperitoneally 30 min after the application of MEC, and after the same dose of MEL was given every 12 h for a total of six doses. SMT (50 mg/kg) was also given intraperitoneally 30 min after the application of MEC.

RESULTS: MEC injection resulted in alveolar epithelial injury, hemorrhage, inflammation, edema and interalveolar septal thickening in the lung tissues. The tissue TNF-α, IL-1β, and nitrate/nitrite (NOx) levels were found significantly different for all groups (p<0.001). TNF-α and IL-1β levels increased significantly with MEC exposure, and MEL and SMT ameliorated these increases in lung tissues. MEC also elevated NOx levels in lung tissue. Melatonin showed meaningful protection against lung injury. But protection of SMT was weaker.

CONCLUSION: Inflammation plays an important role in the MEC induced lung toxicity as well as oxidative and nitrosative stress. Melatonin has also anti-inflammatory properties similar to SMT, as well as anti-oxidant properties. But melatonin treatment was found more efficient than SMT treatment.

Journal Article

Abstract  AIM: To evaluate the pepsin and oxidative stress markers in exhaled breath condensate (EBC) in patients with gastroesophageal reflux disease (GERD).

PATIENTS AND METHOD: Patients with a presumptive diagnosis of GERD with recurrent respiratory and gastrointestinal problems aged between 2 and 14 years were included in the study. All patients underwent pH monitoring. Patients with a reflux index (RI) ≥4 were assessed as the reflux group, and those with an RO <4 were assessed as the non-reflux group. Pepsin levels and oxidative stress markers [NO metabolites (NOX) and total sulphydrile (TSH) levels] were measured in the EBC.

RESULTS: There were 24 patients in the reflux group [RI 17.6 (6.6-46.4)] [median, interquartile range] and 23 in the non-reflux group [RI 0.8 (0.5-1.9) (p<0.001). Pepsin levels in the EBC were below the level of detection. The median levels of NOx in the EBC of children with reflux [13.7 μmol/L (7.3-24.5)] were lower in than non-reflux group [21.0 μmol/L (14.0-25.2)] (p=0.034). There was a negative correlation between reflux index and NOX levels in EBC (rs: -0.331, p=0.023). In contrast, there was no difference in TSH levels between the reflux and non-reflux groups [37.4 μmol/L (30.2-44.6) vs 40.1 μmol/L (37.4-44.9), respectively, (p>0.05)].

CONCLUSION: Decreased levels of NOX in patients with GER disease suggest increased oxidative stress in airways of these patients.

Journal Article

Abstract  This work proposes a novel method for the determination of trace concentrations of Cu, Mn and Ni in biodiesel samples by electrothermal atomic absorption spectrometry. In order to overcome problems related to the organic matrix in the direct introduction of the samples, a new extraction approach was investigated. The method was based on the extraction induced by emulsion breaking, in which metals were transferred from the biodiesel to an acid aqueous phase after formation and breaking of a water-in-oil emulsion prepared by mixing the biodiesel sample with an aqueous solution containing surfactant and nitric acid. Several parameters that could influence the performance of the system were evaluated. Quantitative extractions of the analytes were obtained when the extraction was performed using an emulsifier solution containing 2.1 mol L(-1) of HNO3 and 7% m/v of Triton X-100. The extraction time had remarkable influence on the efficiency of the process, being necessary an agitation time of 60 min to achieve maximum extraction. The limits of quantification were below 1 µg L(-1) for the three analytes under study. The accuracy of the method was tested by application of a recovery test (recovery percentages between 89% and 109% were observed) and by comparison with a well-established method, taken as reference.

Journal Article

Abstract  The intrinsic electrocatalytic properties of functionalized graphene sheets (FGSs) in nitric oxide (NO) sensing are determined by cyclic voltammetry with FGS monolayer electrodes. The degrees of reduction and defectiveness of the FGSs are varied by employing different heat treatments during their fabrication. FGSs with intermediate degrees of reduction and high Raman ID to IG peak ratios exhibit an NO oxidation peak potential of 794 mV (vs 1 M Ag/AgCl), closely matching values obtained with a platinized Pt control (791 mV) as well as recent results from the literature on porous or biofunctionalized electrodes. We show that the peak potential obtained with FGS electrodes can be further reduced to 764 mV by incorporation of electrode porosity using a drop-casting approach, indicating a stronger apparent electrocatalytic effect on porous FGS electrodes as compared to platinized Pt. Taking into consideration effects of electrode morphology, we thereby demonstrate that FGSs are intrinsically as catalytic toward NO oxidation as platinum. The lowered peak potential of porous FGS electrodes is accompanied by a significant increase in peak current, which we attribute either to pore depletion effects or an amplification effect due to subsequent electrooxidation reactions. Our results suggest that the development of sensor electrodes with higher sensitivity and lower detection limits should be feasible with FGSs.

Journal Article

Abstract  Five metal complexes of 2-methylisothiazol-3(2H)-one (MIO), [Co(III)(NH3)5(MIO)](3+), [Ru(II)(NH3)5(MIO)](2+), [Ru(III)(NH3)5(MIO)](3+), [Pt(II)Cl3(MIO)](-), and trans-[U(VI)O2(NO3)2(MIO)2], were synthesized, and their structures were determined by single-crystal X-ray crystallography. MIO is an ambidentate ligand and coordinates to metal centers through its oxygen atom in the cobalt(III), ruthenium(III), and uranium(VI) complexes and through its sulfur atom in the ruthenium(II) and platinum(III) complexes. This result suggests that MIO shows preferential behavior on its donating atoms. We also studied the electron-donor abilities of the oxygen and sulfur atoms of MIO. Various physical measurements on the conjugate acid of MIO and the MIO complexes allowed us to determine an acid dissociation constant (pKa) and donor number (DN) for the oxygen atom of MIO and Lever's electrochemical parameter (EL) and a relative covalency parameter (kL) for the sulfur atom.

Journal Article

Abstract  In recent decades, ambient air pollution has been an important public health issue in Beijing, but little is known about air pollution and health effects after the 2008 Beijing Olympics. We conduct a time-series analysis to evaluate associations between daily mortality (nonaccidental, cardiovascular and respiratory mortality) and the major air pollutants (carbon monoxide, nitrogen dioxide and particulate matter less than 10 µm in aerodynamic diameter) in Beijing during the two years (2009,2010) after the 2008 Beijing Olympics. We used generalized additive model to analyze relationship between daily mortality and air pollution. In single air pollutant model with two-day moving average concentrations of the air pollutants, increase in their interquartile range (IQR) associated with percent increase in nonaccidental mortality, 2.55 percent [95% confidence interval (CI): 1.99, 3.11] for CO, 2.54 percent (95% CI: 2.00, 3.08) for NO2 and 1.80 percent (95% CI: 1.21, 2.40) for PM10, respectively; increases in the IQR of air pollutant concentrations associated with percent increase in cardiovascular mortality, 2.88 percent (95% CI: 2.10,3.65) for CO, 2.63 percent (95% CI: 1.87, 3.39) for NO2 and 1.72 percent (95% CI: 0.88, 2.55) for PM10, respectively; and increase in IQR of air pollutant concentrations associated with respiratory mortality, 2.39 percent (95% CI: 0.68, 4.09) for CO, 1.79 percent (95% CI: 0.11, 3.47) for NO2 and 2.07 percent (95% CI: 0.21, 3.92) for PM10, respectively. We used the principal component analysis to avoid collinearity of varied air pollutants. In addition, the association stratified by sex and age was also examined. Ambient air pollution remained a significant contributor to nonaccidental and cardiopulmonary mortalities in Beijing during 2009,2010.

Journal Article

Abstract  There are well-established approaches for osteogenic differentiation of embryonic stem cells (ESCs), but few show direct comparison with primary osteoblasts or demonstrate differences in response to external factors. Here, we show comparative analysis of in vitro osteogenic differentiation of mouse ESC (osteo-mESC) and mouse primary osteoblasts. Both cell types formed mineralized bone nodules and produced osteogenic extracellular matrix, based on immunostaining for osteopontin and osteocalcin. However, there were marked differences in the morphology of osteo-mESCs and levels of mRNA expression for osteogenic genes. In response to the addition of proinflammatory cytokines interleukin-1β, tumor necrosis factor-α, and interferon-γ to the culture medium, primary osteoblasts showed increased production of nitric oxide (NO) and prostaglandin E2 (PGE2) at early time points and decreases in cell viability. In contrast, osteo-mESCs maintained viability and did not produce NO and PGE2 until day 21. The formation of bone nodules by primary osteoblasts was reduced markedly after cytokine stimulation but was unaffected in osteo-mESCs. Cell sorting of osteo-mESCs by cadherin-11 (cad-11) showed clear osteogenesis of cad-11(+) cells compared to unsorted osteo-mESCs and cad-11(-) cells. Moreover, the cad-11(+) cells showed a significant response to cytokines, similar to primary osteoblasts. Overall, these results show that while osteo-mESC cultures, without specific cell sorting, show characteristics of osteoblasts, there are also marked differences, notably in their responses to cytokine stimuli. These findings are relevant to understanding the differentiation of stem cells and especially developing in vitro models of disease, testing new drugs, and developing cell therapies.

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Journal Article

Abstract  This paper reviews existing vehicle environmental rating methodologies worldwide and focuses on how these methodologies deal with alternative vehicle technologies (plug-in vehicles, hybrid vehicles, and fuel cell vehicles) and emissions of greenhouse gases (CO2, N2O, and CH4) and pollutants (NOx, VOC, CO, SOx, PM10 and PM25) derived from embodied materials life cycle. United States, Mexico, Europe and Australia have public access data and websites with top 10 rankings. The ways the scores are calculated for each vehicle have differences in what regards the considered boundaries for the emissions analysis. In Europe, there is still not a unique rating methodology or ranking system, e.g., Belgium, Germany and United Kingdom have their specific scoring schemes. Multilinear regression models were developed as an attempt to estimate the vehicle embodied emissions as a function of vehicle lifecycle mileage, electricity mix, vehicle mass, battery mass and fuel cell power to cope with different production regions and different alternative vehicle technologies. The regression models were validated against Volkswagen life cycle assessments (LCAs), and compared against American Council for an Energy Efficient Economy (ACEEE) - Green Book linear functions for material assessment and UK 12 material dataset for materials assessment. The developed models proved to be useful in applications related to rating methodologies using life-cycle concepts, with good reliability for comparisons considering the complexity of processes involved in vehicle materials life-cycle assessment. (C) 2014 Elsevier Ltd. All rights reserved.

Journal Article

Abstract  Several papers reported associations between airborne fine particulate matter (PM2.5) and birth weight, though findings are inconsistent across studies. Conflicting results might be due to (1) different PM2.5 chemical structure across locations, and (2) various exposure assignment methods across studies even among the studies that use ambient monitors to assess exposure. We investigated associations between birth weight and PM2.5 chemical constituents, considering issues arising from choice of buffer size (i.e. distance between residence and pollution monitor). We estimated the association between each pollutant and term birth weight applying buffers of 5 to 30 km in Connecticut (2000-2006), in the New England region of the USA. We also investigated the implication of the choice of buffer size in relation to population characteristics, such as socioeconomic status. Results indicate that some PM2.5 chemical constituents, such as nitrate, are associated with lower birth weight and appear more harmful than other constituents. However, associations vary with buffer size and the implications of different buffer sizes may differ by pollutant. A homogeneous pollutant level within a certain distance is a common assumption in many environmental epidemiology studies, but the validity of this assumption may vary by pollutant. Furthermore, we found that areas close to monitors reflect more minority and lower socio-economic populations, which implies that different exposure approaches may result in different types of study populations. Our findings demonstrate that choosing an exposure method involves key tradeoffs of the impacts of exposure misclassification, sample size, and population characteristics.

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Journal Article

Abstract  An improved quantitative method was used for measuring benzene, toluene, ethyl benzene, m/p-xylene and o-xylene (BTEX)] by preconcentration on active charcoal followed by gas chromatography-mass spectrometry (GC/MS) analysis. The selected ion monitoring (SIM) mode was used for the quantitative GC/MS analysis. The internal standard used was stable isotopically labeled benzene. The compounds of interest were eluted in 7.5 min. The method is simple, rapid and shows good validation parameters (linearity, precision and accuracy) for the studied compounds. The method was tested for the investigation of the indoor emissions from different materials and furniture. The results showed that attention should be paid to the new furniture and to the inflating indoor of the new vacuum packed mattresses.

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Abstract  Nanocrystalline and nanostructured TiO2-Cr2O3 thin films and powders were prepared by a facile and straightforward aqueous particulate sol-gel route at low temperature of 400A degrees C. The prepared sols showed a narrow particle size distribution with hydrodynamic diameter in the range of 17.7 nm to 19.0 nm. Moreover, the sols were stable over 4 months, with constant zeta potential measured during this period. The effect of the Cr:Ti molar ratio on the crystallization behavior of the products was studied. X-ray diffraction (XRD) analysis revealed that the powders crystallized at low temperature of 400A degrees C, containing anatase-TiO2, rutile-TiO2, and Cr2O3 phases, depending on the annealing temperature and Cr:Ti molar ratio. Furthermore, it was found that Cr2O3 retarded the anatase to rutile transformation up to 800A degrees C. The activation energy of crystallite growth was calculated to be in the range of 1.3 kJ/mol to 2.9 kJ/mol. Transmission electron microscopy (TEM) imaging showed that one of the smallest crystallite sizes was obtained for TiO2-Cr2O3 binary mixed oxide, being 5 nm at 500A degrees C. Field-emission scanning electron microscopy (FESEM) analysis revealed that the deposited thin films had nanostructured morphology with average grain size in the range of 20 nm to 40 nm at 500A degrees C. Thin films produced under optimized conditions showed excellent microstructural properties for gas sensing applications. They exhibited a remarkable response towards low concentrations of NO2 gas at low operating temperature of 200A degrees C, resulting in increased thermal stability of sensing films as well as a decrease in their power consumption. Furthermore, calibration curves revealed that TiO2-Cr2O3 sensors followed the power law (where S is the sensor response, the coefficients A and B are constants, and [gas] is the gas concentration) for two types of gas, exhibiting excellent capability for detection of low gas concentrations.

DOI
Journal Article

Abstract  Concentrations of fine carbonaceous aerosols (PM(2.5)), including elemental carbon (EC), organic carbon (OC), and water-soluble organic carbon (WSOC) were measured from filters collected every 6th day for one year at three urban/industrial sites in the Midwestern United States: Cincinnati, Cleveland, and Mingo Junction, Ohio. The water-soluble fraction of fine particulate OC varied considerably from site to site and monthly averages were between 3985% at Cincinnati, 35-68% at Cleveland, and 32-65% at Mingo Junction. Average monthly concentrations of WSOC were compared with measurements of organic source tracers, including levoglucosan, to better understand the spatial and temporal distribution and sources of WSOC. Two methods of predicting the non-biomass burning portion of WSOC (WSOC(NB)) were compared including estimation of secondary organic carbon (SOC) by the EC-tracer Method and comparison of the unapportioned OC from a chemical mass balance (CMB) source apportionment analysis. Poor correlations between SOC estimated by the EC-tracer method and WSOC(NB) suggested that the use of the EC-tracer method to estimate SOC may be significantly flawed with respect to low time-resolved measurements, such as one-in-six day measurements. Good correlations between CMB unapportioned OC and WSOC(NB) at all three sites (R(2) = 0.68 to 0.91) suggested that direct measurements of levoglucosan and WSOC could provide a reasonable estimate of secondary organic carbon concentrations in some locations. However, application of this method to daily measurements made in Detroit, MI during July of 2007 and January/February of 2008 demonstrated that, on some individual days near large point sources, non-biomass burning sources of WSOC were important contributors to WSOC concentrations.

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