scholarly journals Size distribution and total number concentration of ultrafine and accumulation mode particles and hospital admissions in children and the elderly in Copenhagen, Denmark

2008 ◽  
Vol 65 (7) ◽  
pp. 458-466 ◽  
Author(s):  
Z J Andersen ◽  
P Wahlin ◽  
O Raaschou-Nielsen ◽  
M Ketzel ◽  
T Scheike ◽  
...  
Keyword(s):  
Size Distribution ◽  
Hospital Admissions ◽  
The Elderly ◽  
Number Concentration ◽  
Accumulation Mode

scholarly journals The time evolution of aerosol size distribution over the Mexico City plateau

2009 ◽  
Vol 9 (13) ◽  
pp. 4261-4278 ◽  
Author(s):  
L. I. Kleinman ◽  
S. R. Springston ◽  
J. Wang ◽  
P. H. Daum ◽  
Y.-N. Lee ◽  
...  
Keyword(s):  
Size Distribution ◽  
Mexico City ◽  
Volume Growth ◽  
Fold Increase ◽  
Number Concentration ◽  
Aerosol Size Distribution ◽  
Detailed Model ◽  
Accumulation Mode ◽  
Mode Size ◽  
Aerosol Volume

Abstract. As part of the MILAGRO field campaign, the DOE G-1 aircraft was used to make measurements over and downwind of Mexico City with the objective of determining growth characteristics of aerosols from a megacity urban source. This study focuses on number concentration and size distributions. It is found that a 5-fold increase in aerosol volume is accompanied by about a 5-fold increase in accumulation mode number concentration. There is growth in aerosol volume because there are more accumulation mode particles, not because of an increase in the average size of accumulation particles. Condensation and volume growth laws were examined to see whether either is consistent with observations. Condensation calculations show that the growth of Aitken mode particles into the accumulation mode size range gives the required increase in number concentration. There are minimal changes in the accumulation mode size distribution with age, consistent with observations. Volume-growth in contrast yields a population of large particles, distinctly different from what is observed. Detailed model calculations are required to translate our observations into specific information on the volatility and properties of secondary organic aerosol.

scholarly journals The time evolution of aerosol size distribution over the Mexico City plateau

2009 ◽  
Vol 9 (1) ◽  
pp. 1621-1668
Author(s):  
L. I. Kleinman ◽  
S. R. Springston ◽  
J. Wang ◽  
P. H. Daum ◽  
Y.-N. Lee ◽  
...  
Keyword(s):  
Size Distribution ◽  
Mexico City ◽  
Volume Growth ◽  
Fold Increase ◽  
Number Concentration ◽  
Aerosol Size Distribution ◽  
Detailed Model ◽  
Accumulation Mode ◽  
Mode Size ◽  
Aerosol Volume

Abstract. As part of the MILAGRO field campaign, the DOE G-1 aircraft was used to make measurements over and downwind of Mexico City with the objective of determining growth characteristics of aerosols from a megacity urban source. This study focuses on number concentration and size distributions. It is found that a 5-fold increase in aerosol volume is accompanied by about a 5-fold increase in accumulation mode number concentration. There is growth in aerosol volume because there are more accumulation mode particles, not because particles are larger. Condensation and volume growth laws were examined to see whether either is consistent with observations. Condensation calculations show that the growth of Aitken mode particles into the accumulation mode size range gives the required increase in number concentration. There are minimal changes in the accumulation mode size distribution with age, consistent with observations. Volume-growth in contrast yields a population of large particles, distinctly different from what is observed. Detailed model calculations are required to translate our observations into specific information on the volatility and properties of secondary organic aerosol.

scholarly journals The impact of COVID-19 infection on hip fracture 30-day mortality

Trauma ◽  
2021 ◽  
pp. 146040862094972
Author(s):  
Ahmed Fadulelmola ◽  
Rob Gregory ◽  
Gavin Gordon ◽  
Fiona Smith ◽  
Andrew Jennings
Keyword(s):  
Hip Fracture ◽  
Hip Fractures ◽  
Hospital Admissions ◽  
The Elderly ◽  
Primary Outcome Measure ◽  
Time To Death ◽  
Significant Difference ◽  
The Mean ◽  
The Impact ◽  
Mean Time

Introduction: A novel virus, SARS-CoV-2, has caused a fatal global pandemic which particularly affects the elderly and those with comorbidities. Hip fractures affect elderly populations, necessitate hospital admissions and place this group at particular risk from COVID-19 infection. This study investigates the effect of COVID-19 infection on 30-day hip fracture mortality. Method: Data related to 75 adult hip fractures admitted to two units during March and April 2020 were reviewed. The mean age was 83.5 years (range 65–98 years), and most (53, 70.7%) were women. The primary outcome measure was 30-day mortality associated with COVID-19 infection. Results: The COVID-19 infection rate was 26.7% (20 patients), with a significant difference in the 30-day mortality rate in the COVID-19-positive group (10/20, 50%) compared to the COVID-19-negative group (4/55, 7.3%), with mean time to death of 19.8 days (95% confidence interval: 17.0–22.5). The mean time from admission to surgery was 43.1 h and 38.3 h, in COVID-19-positive and COVID-19-negative groups, respectively. All COVID-19-positive patients had shown symptoms of fever and cough, and all 10 cases who died were hypoxic. Seven (35%) cases had radiological lung findings consistent of viral pneumonitis which resulted in mortality (70% of mortality). 30% ( n = 6) contracted the COVID-19 infection in the community, and 70% ( n = 14) developed symptoms after hospital admission. Conclusion: Hip fractures associated with COVID-19 infection have a high 30-day mortality. COVID-19 testing and chest X-ray for patients presenting with hip fractures help in early planning of high-risk surgeries and allow counselling of the patients and family using realistic prognosis.

Preventable and Non-Preventable Risk Factors for Adverse Drug Events Related to Hospital Admissions in the Elderly

2002 ◽  
Vol 22 (6) ◽  
pp. 385-392 ◽  
Author(s):  
J. Doucet ◽  
A. Jego ◽  
D. Noel ◽  
C.E. Geffroy ◽  
C. Capet ◽  
...  
Keyword(s):  
Risk Factors ◽  
Adverse Drug Events ◽  
Hospital Admissions ◽  
The Elderly

scholarly journals Size-resolved and bulk activation properties of aerosols in the North China Plain

2011 ◽  
Vol 11 (8) ◽  
pp. 3835-3846 ◽  
Author(s):  
Z. Z. Deng ◽  
C. S. Zhao ◽  
N. Ma ◽  
P. F. Liu ◽  
L. Ran ◽  
...  
Keyword(s):  
Size Distribution ◽  
North China Plain ◽  
North China ◽  
Cloud Condensation Nuclei ◽  
Number Concentration ◽  
Anthropogenic Aerosol ◽  
Number Size Distribution ◽  
The North ◽  
The North China Plain ◽  
Activation Ratio

Abstract. Size-resolved and bulk activation properties of aerosols were measured at a regional/suburban site in the North China Plain (NCP), which is occasionally heavily polluted by anthropogenic aerosol particles and gases. A Cloud Condensation Nuclei (CCN) closure study is conducted with bulk CCN number concentration (NCCN) and calculated CCN number concentration based on the aerosol number size distribution and size-resolved activation properties. The observed CCN number concentration (NCCN-obs) are higher than those observed in other locations than China, with average NCCN-obs of roughly 2000, 3000, 6000, 10 000 and 13 000 cm−3 at supersaturations of 0.056, 0.083, 0.17, 0.35 and 0.70%, respectively. An inferred critical dry diameter (Dm) is calculated based on the NCCN-obs and aerosol number size distribution assuming homogeneous chemical composition. The inferred cut-off diameters are in the ranges of 190–280, 160–260, 95–180, 65–120 and 50–100 nm at supersaturations of 0.056, 0.083, 0.17, 0.35 and 0.7%, with their mean values 230.1, 198.4, 128.4, 86.4 and 69.2 nm, respectively. Size-resolved activation measurements show that most of the 300 nm particles are activated at the investigated supersaturations, while almost no particles of 30 nm are activated even at the highest supersaturation of 0.72%. The activation ratio increases with increasing supersaturation and particle size. The slopes of the activation curves for ambient aerosols are not as steep as those observed in calibrations with ammonium sulfate suggesting that the observed aerosols is an external mixture of more hygroscopic and hydrophobic particles. The calculated CCN number concentrations (NCCN-calc) based on the size-resolved activation ratio and aerosol number size distribution correlate well with the NCCN-obs, and show an average overestimation of 19%. Sensitivity studies of the CCN closure show that the NCCN at each supersaturation is well predicted with the campaign average of size-resolved activation curves. These results indicate that the aerosol number size distribution is critical in the prediction of possible CCN. The CCN number concentration can be reliably estimated using time-averaged, size-resolved activation efficiencies without accounting for the temporal variations.

scholarly journals Quantifying the impact of air pollution on the urban population of Brazil

2007 ◽  
Vol 23 (suppl 4) ◽  
pp. S529-S536 ◽  
Author(s):  
Izabel Marcilio ◽  
Nelson Gouveia
Keyword(s):  
Air Pollution ◽  
Urban Population ◽  
Hospital Admissions ◽  
Age Groups ◽  
The Elderly ◽  
Impact Factors ◽  
Pollution Levels ◽  
Time Series Studies ◽  
The Impact ◽  
Respiratory Causes

This study aimed to quantify air pollution impact on morbidity and mortality in the Brazilian urban population using locally generated impact factors. Concentration-response coefficients were used to estimate the number of hospitalizations and deaths attributable to air pollution in seven Brazilian cities. Poisson regression coefficients (beta) were obtained from time-series studies conducted in Brazil. The study included individuals 65 years old and over and children under five. More than 600 deaths a year from respiratory causes in the elderly and 47 in children were attributable to mean air pollution levels, corresponding to 4.9% and 5.5% of all deaths from respiratory causes in these age groups. More than 4,000 hospital admissions for respiratory conditions were also attributable to air pollution. These results quantitatively demonstrate the currently observed contribution of air pollution to mortality and hospitalizations in Brazilian cities. Such assessment is thought to help support the planning of surveillance and control activities for air pollution in these and similar areas.

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