We measured the radiocarbon (14C) content of organic carbon (OC) samples from two locations in the Netherlands, the urban location of Amsterdam and the coastal location of Petten. PM10 samples were ...collected in Amsterdam and total suspended particles were collected in Petten using high volume samplers. The 14C/12C fraction in the samples is reported as fraction modern (F14C). It can be used to roughly estimate the contribution of fossil sources to OC, since F14C of fossil fuels is 0, whereas biogenic and wood burning sources are characterized by F14C values close to 1. At the coastal location organic carbon has higher F14C values (0.83 ± 0.04 standard uncertainty) than at the urban location (0.68 ± 0.05). A fraction modern of 0.68 is in the range of F14C values published for OC of other European urban areas (0.68–0.81). The coastal F14C of 0.83 agrees well with measurements at the coastal location of Mace Head, even though in Mace Head measurements were made on particles smaller than 1.5 μm (PM1.5). A F14C of 0.83 is on the lower end of F14C(OC) values estimated for continental background sites in Europe. Fossil sources might be contributing slightly more to organic carbon in the Netherlands than in other European regions. However, a bigger data set is needed to substantiate this finding. On average, fossil fuel combustion is responsible for approximately 40% of the organic carbon in Amsterdam and approximately 20% at the coastal location. At the coastal location, F14C was clearly lower than average when polluted air masses reached the measurement site, whereas in the urban area, air mass history did not have a strong influence on F14C.
•First measurements of 14C in organic carbon (OC) in the Netherlands.•Modern sources dominate OC both at the urban and coastal site.•Significantly higher F14C(OC) at the coastal site than at the urban site.•Clear signature of pollution long-range transport in F14C(OC) at the coastal site.
OBJECTIVE To evaluate the effect of prolonged partial liquid ventilation with perflubron (partial liquid ventilation), using conventional and high-frequency ventilatory techniques, on gas exchange, ...hemodynamics, and lung pathology in an animal model of lung injury.
DESIGN Prospective, randomized, controlled study.
SETTING Animal laboratory of the Infant Pulmonary Research Center, Children's Health Care-St. Paul.
SUBJECTS Thirty-six newborn piglets.
INTERVENTIONS We studied newborn piglets with lung injury induced by saline lavage. Animals were randomized into one of five treatment groupsa) conventional gas ventilation (n = 8); b) partial liquid ventilation with conventional ventilation (n = 7); c) partial liquid ventilation with high-frequency jet ventilation (n = 7); d) partial liquid ventilation with high-frequency oscillation (n = 7); and e) partial liquid ventilation with high-frequency flow interruption (n = 7). After induction of lung injury, all partial liquid ventilation animals received intratracheal perflubron to approximate functional residual capacity. After 30 mins of stabilization, animals randomized to high-frequency ventilation were changed to their respective high-frequency modes. Hemodynamics and blood gases were measured before and after lung injury, after perflubron administration, and then every 4 hrs for 20 hrs. Histopathologic evaluation was carried out using semiquantitative scoring and computer-assisted morphometric analysis on pulmonary tissue from animals surviving at least 16 hrs.
MEASUREMENTS AND MAIN RESULTS All animals developed acidosis and hypoxemia after lung injury. Oxygenation significantly (p < .001) improved after perflubron administration in all partial liquid ventilation groups. After 4 hrs, oxygenation was similar in all ventilator groups. The partial liquid ventilation-jet ventilation group had the highest pH; intergroup differences were seen at 16 and 20 hrs (p < .05). The partial liquid ventilation-oscillation group required higher mean airway pressure; intergroup differences were significant at 4 and 8 hrs (p < .05). Aortic pressures, central venous pressures, and heart rates were not different at any time point. Survival rate was significantly lower in the partial liquid ventilation-flow interruption group (p < .05). All partial liquid ventilation-treated animals had less lung injury compared with gas-ventilated animals by both histologic and morphometric analysis (p < .05). The lower lobes of all partial liquid ventilation-treated animals demonstrated less damage than the upper lobes, although scores reached significance (p < .05) only in the partial liquid ventilation-conventional ventilation animals.
CONCLUSIONS In this animal model, partial liquid ventilation using conventional or high-frequency ventilation provided rapid and sustained improvements in oxygenation without adverse hemodynamic consequences. Animals treated with partial liquid ventilation-flow interruption had a significantly decreased survival rate vs. animals treated with the other studied techniques. Histopathologic and morphometric analysis showed significantly less injury in the lower lobes of lungs from animals treated with partial liquid ventilation. High-frequency ventilation techniques did not further improve pathologic outcome. (Crit Care Med 1997; 25:1888-1897)
This paper presents an analytical system for analysis of all single substituted isotopologues (12C16O17O, 12C16O18O, 13C16O16O) in nanomolar quantities of CO2 extracted from stratospheric air ...samples. CO2 is separated from bulk air by gas chromatography and CO2 isotope ratio measurements (ion masses 45 / 44 and 46 / 44) are performed using isotope ratio mass spectrometry (IRMS). The 17O excess (Δ17O) is derived from isotope measurements on two different CO2 aliquots: unmodified CO2 and CO2 after complete oxygen isotope exchange with cerium oxide (CeO2) at 700 °C. Thus, a single measurement of Δ17O requires two injections of 1 mL of air with a CO2 mole fraction of 390 μmol mol−1 at 293 K and 1 bar pressure (corresponding to 16 nmol CO2 each). The required sample size (including flushing) is 2.7 mL of air. A single analysis (one pair of injections) takes 15 minutes. The analytical system is fully automated for unattended measurements over several days. The standard deviation of the 17O excess analysis is 1.7‰. Multiple measurements on an air sample reduce the measurement uncertainty, as expected for the statistical standard error. Thus, the uncertainty for a group of 10 measurements is 0.58‰ for Δ 17O in 2.5 h of analysis. 100 repeat analyses of one air sample decrease the standard error to 0.20‰. The instrument performance was demonstrated by measuring CO2 on stratospheric air samples obtained during the EU project RECONCILE with the high-altitude aircraft Geophysica. The precision for RECONCILE data is 0.03‰ (1σ) for δ13C, 0.07‰ (1σ) for δ18O and 0.55‰ (1σ) for δ17O for a sample of 10 measurements. This is sufficient to examine stratospheric enrichments, which at altitude 33 km go up to 12‰ for δ17O and up to 8‰ for δ18O with respect to tropospheric CO2 : δ17O ~ 21‰ Vienna Standard Mean Ocean Water (VSMOW), δ18O ~ 41‰ VSMOW (Lämmerzahl et al., 2002). The samples measured with our analytical technique agree with available data for stratospheric CO2.
Gestational weight gain (GWG) is important for health policy as it may be associated with overweight epidemics in childhood and adolescence. The purpose of the study was to perform the risk ...assessment of joint effects of the excessive GWG and the pregravid maternal BMI on overweight in infancy and childhood. The observations were collected in the ongoing prospective birth cohort study of 482 non-smoking mothers and their newborns in Cracow inner city area. At 5 years of age the subsample of 312 infants were reexamined in order to assess their nutritional status. Body fatness was assessed by means of the weight/length ratio (WLR) in neonates and weight/height ratio (WHR) in 5-year-olds since they showed the strongest correlation with subcutaneous fat mass of young children. In the statistical analysis the binary regression models were applied to identify predictors of overweight. The excessive GWG (>18 kg) increased more than twofold the adjusted relative risk (RR) of neonatal fatness (R=2.7; 95% CI 2.0-3.7) and was also a significant independent risk factor for postnatal body fatness at 5 years of age (RR=2.0; 95% CI: 1.3-3.3). The results confirmed earlier findings that pregravid overweight increased not only the relative risk of neonatal fatness (RR=2.9; 95% CI: 2.2-3.9) but also overweight in early childhood (RR=2.7; 95% CI: 1.7-4.4). The conclusion is that excessive GWG may be a risk factor for overweight in early childhood and should be a focus of public health policy.
We compared the effects of surfactant and partial liquid ventilation (PLV), and the impact of administration order, on oxygenation, respiratory system compliance (Crs), hemodynamics, and lung ...pathology in an animal lung injury model. We studied four groups: surfactant alone (S; n = 8); partial liquid ventilation alone (PLV-only; n = 8); surfactant followed by partial liquid ventilation (S-PLV; n = 8); and partial liquid ventilation-followed by surfactant (PLV-S; n = 8). Following treatments, all animals had improved oxygenation index (OI) and Crs. Animals in PLV groups showed continued improvement over 2 h (% change OI: PLV-S -83% versus S -47%, p < 0.05; % change Crs: S-PLV 73% versus S 13%, p < 0.05). We also saw administration-order effects: surfactant before PLV improved Crs (0.92 ml/cm H2O after surfactant versus 1.13 ml/cm H2O after PLV, p < 0.02) without changing OI, whereas surfactant after PLV did not change Crs and OI increased (5.01 after PLV versus 8.92 after surfactant, p < 0.03). Hemodynamics were not different between groups. Pathologic analysis demonstrated decreased lung injury in dependent lobes of all PLV-treated animals, and in all lobes of S-PLV animals, when compared with the lobes of the S animals (p < 0.05). We conclude that surfactant therapy in combination with PLV improved oxygenation, respiratory system mechanics, and lung pathology to a greater degree than surfactant therapy alone. Administration order affected initial physiologic response and ultimate pathology: surfactant given before PLV produced the greatest improvements in pathologic outcomes.
This paper presents an analytical system for analysis of all single substituted isotopologues (12C16O17O, 12C16O18O, 13C16O16O) in nanomolar quantities of CO2 extracted from stratospheric air ...samples. CO2 is separated from bulk air by gas chromatography and CO2 isotope ratio measurements (ion masses 45 / 44 and 46 / 44) are performed using isotope ratio mass spectrometry (IRMS). The 17O excess (Δ17O) is derived from isotope measurements on two different CO2 aliquots: unmodified CO2 and CO2 after complete oxygen isotope exchange with cerium oxide (CeO2) at 700 °C. Thus, a single measurement of Δ17O requires two injections of 1 mL of air with a CO2 mole fraction of 390 μmol mol−1 at 293 K and 1 bar pressure (corresponding to 16 nmol CO2 each). The required sample size (including flushing) is 2.7 mL of air. A single analysis (one pair of injections) takes 15 minutes. The analytical system is fully automated for unattended measurements over several days. The standard deviation of the 17O excess analysis is 1.7‰. Multiple measurements on an air sample reduce the measurement uncertainty, as expected for the statistical standard error. Thus, the uncertainty for a group of 10 measurements is 0.58‰ for Δ 17O in 2.5 h of analysis. 100 repeat analyses of one air sample decrease the standard error to 0.20‰. The instrument performance was demonstrated by measuring CO2 on stratospheric air samples obtained during the EU project RECONCILE with the high-altitude aircraft Geophysica. The precision for RECONCILE data is 0.03‰ (1σ) for δ13C, 0.07‰ (1σ) for δ18O and 0.55‰ (1σ) for δ17O for a sample of 10 measurements. This is sufficient to examine stratospheric enrichments, which at altitude 33 km go up to 12‰ for δ17O and up to 8‰ for δ18O with respect to tropospheric CO2 : δ17O ~ 21‰ Vienna Standard Mean Ocean Water (VSMOW), δ18O ~ 41‰ VSMOW (Lämmerzahl et al., 2002). The samples measured with our analytical technique agree with available data for stratospheric CO2.
OBJECTIVE:To test the hypothesis that perfluorocarbon (PFC) priming before surfactant administration improves gas exchange and lung compliance, and also decreases lung injury, more than surfactant ...alone.
DESIGN:Prospective, randomized animal study.
SETTING:Animal research laboratory of Children's Hospital of St. Paul.
SUBJECTS:Thirty-two newborn piglets, weighing 1.55 ± 0.18 kg.
INTERVENTIONS:We studied four groups of eight animals randomized after anesthesia, paralysis, tracheostomy, and establishment of lung injury using saline washout to receive one of the following treatmentsa) surfactant alone (n = 8); b) priming with the PFC perflubron alone (n = 8); c) priming with perflubron followed by surfactant (n = 8); and d) no treatment (control; n = 8). Perflubron priming was achieved by instilling perflubron via the endotracheal tube in an amount estimated to represent the functional residual capacity, ventilating the animal for 30 mins, and then removing perflubron by suctioning. After all treatments were given, animals were mechanically ventilated for 4 hrs.
MEASUREMENTS AND MAIN RESULTS:We evaluated oxygenation, airway pressures, respiratory system compliance, and hemodynamics at baseline, after induction of lung injury, and at 30-min intervals for 4 hrs. Histopathologic evaluation was carried out using a semiquantitative scoring system and by computer-assisted morphometric analysis. After all treatments, animals had decreased oxygenation indices (p < .001) and increased respiratory system compliance (p < .05). Animals in PFC groups had similar physiologic responses to treatments as animals treated with surfactant only; both the PFC-treated groups and the surfactant-treated animals required lower mean airway pressures throughout the experiment (p < .001) and had higher pH levels at 90 and 120 mins (p < .05) compared with the control group. Pathologic analysis demonstrated decreased lung injury in surfactant-treated animals compared with animals treated with PFC or the controls (p < .02).
CONCLUSIONS:Priming the lung with PFC neither improved the physiologic effects of exogenous surfactant nor improved lung pathology in this animal model.
This paper presents an analytical system for analysis of all single substituted isotopologues (.sup.12 C.sup.16 O.sup.17 O, .sup.12 C.sup.16 O.sup.18 O, .sup.13 C.sup.16 O.sup.16 O) in nanomolar ...quantities of CO.sub.2 extracted from stratospheric air samples. CO.sub.2 is separated from bulk air by gas chromatography and CO.sub.2 isotope ratio measurements (ion masses 45 / 44 and 46 / 44) are performed using isotope ratio mass spectrometry (IRMS). The .sup.17 O excess (Î.sup.17 O) is derived from isotope measurements on two different CO.sub.2 aliquots: unmodified CO.sub.2 and CO.sub.2 after complete oxygen isotope exchange with cerium oxide (CeO.sub.2) at 700 °C. Thus, a single measurement of Î.sup.17 O requires two injections of 1 mL of air with a CO.sub.2 mole fraction of 390 μmol mol.sup.-1 at 293 K and 1 bar pressure (corresponding to 16 nmol CO.sub.2 each). The required sample size (including flushing) is 2.7 mL of air. A single analysis (one pair of injections) takes 15 minutes. The analytical system is fully automated for unattended measurements over several days. The standard deviation of the .sup.17 O excess analysis is 1.7‰. Multiple measurements on an air sample reduce the measurement uncertainty, as expected for the statistical standard error. Thus, the uncertainty for a group of 10 measurements is 0.58‰ for Δ .sup.17 O in 2.5 h of analysis. 100 repeat analyses of one air sample decrease the standard error to 0.20‰. The instrument performance was demonstrated by measuring CO.sub.2 on stratospheric air samples obtained during the EU project RECONCILE with the high-altitude aircraft Geophysica. The precision for RECONCILE data is 0.03‰ (1σ) for delta.sup.13 C, 0.07‰ (1σ) for delta.sup.18 O and 0.55‰ (1σ) for δ.sup.17 O for a sample of 10 measurements. This is sufficient to examine stratospheric enrichments, which at altitude 33 km go up to 12‰ for δ.sup.17 O and up to 8‰ for delta.sup.18 O with respect to tropospheric CO.sub.2 : δ.sup.17 O ~ 21‰ Vienna Standard Mean Ocean Water (VSMOW), delta.sup.18 O ~ 41‰ VSMOW (Lämmerzahl et al., 2002). The samples measured with our analytical technique agree with available data for stratospheric CO.sub.2.
PDF
