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The Science of the Total Environment May 2023Dust particles originating from arid desert regions can be transported over long distances, presenting severe risks to climate, environment, social economics, and human...
Dust particles originating from arid desert regions can be transported over long distances, presenting severe risks to climate, environment, social economics, and human health at the source and downwind regions. However, there has been a dearth of continuous diurnal observations of vertically resolved mass concentration and optical properties of dust aerosols, which hinders our understanding of aerosol mixing, stratification, aerosol-cloud interactions, and their impacts on the environment. To fill the gap of the insufficient observations, to the best of our knowledge, this work presents the first high-spectral-resolution lidar (HSRL) observation providing days of continuous profiles of the mass concentration, along with particle linear depolarization ratio (PLDR), backscattering coefficient, extinction coefficient and lidar ratio (LR), simultaneously. We present the results of two strong dust events observed by HSRL over Beijing in 2021. The maximum particle mass concentrations reached (1.52 ± 3.5) x10 μg/m and (19.48 ± 0.36) x10 μg/m for the two dust events, respectively. The retrieved particle mass concentrations and aerosol optical depth (AOD) agree well with the observation from the surface PM concentrations and sun photometer with correlation coefficients of 0.90 and 0.95, respectively. The intensive properties of PLDR and LR of the dust aerosols are 0.31 ± 0.02 and 39 ± 7 sr at 532 nm, respectively, which are generally close to those obtained from observations in the downwind areas. Moreover, inspired by the observations from HSRL, a universal analytical relationship is discovered to evaluate the proportion of dust aerosol backscattering, extinction, AOD, and mass concentration using PLDR. The universal analytical relationship reveals that PLDR can directly quantify dust aerosol contribution, which is expected to further expand the application of polarization technology in dust detection. These valuable observations and findings further our understanding of the contribution of dust aerosol to the environment and help supplement dust aerosol databases.
PubMed: 36758704
DOI: 10.1016/j.scitotenv.2023.162091 -
Anaesthesia and Intensive Care May 2015We assessed agreement in haemoglobin measurement between Masimo pulse co-oximeters (Rad-7™ and Pronto-7™) and HemoCue® photometers (201+ or B-Hemoglobin) with... (Meta-Analysis)
Meta-Analysis Review
Systematic review and meta-analysis of method comparison studies of Masimo pulse co-oximeters (Radical-7™ or Pronto-7™) and HemoCue® absorption spectrometers (B-Hemoglobin or 201+) with laboratory haemoglobin estimation.
We assessed agreement in haemoglobin measurement between Masimo pulse co-oximeters (Rad-7™ and Pronto-7™) and HemoCue® photometers (201+ or B-Hemoglobin) with laboratory-based determination and identified 39 relevant studies (2915 patients in Masimo group and 3084 patients in HemoCue group). In the Masimo group, the overall mean difference was -0.03 g/dl (95% prediction interval -0.30 to 0.23) and 95% limits of agreement -3.0 to 2.9 g/dl compared to 0.08 g/dl (95% prediction interval -0.04 to 0.20) and 95% limits of agreement -1.3 to 1.4 g/dl in the HemoCue group. Only B-Hemoglobin exhibited bias (0.53, 95% prediction interval 0.27 to 0.78). The overall standard deviation of difference was larger (1.42 g/dl versus 0.64 g/dl) for Masimo pulse co-oximeters compared to HemoCue photometers. Masimo devices and HemoCue 201+ both provide an unbiased, pooled estimate of laboratory haemoglobin. However, Masimo devices have lower precision and wider 95% limits of agreement than HemoCue devices. Clinicians should carefully consider these limits of agreement before basing transfusion or other clinical decisions on these point-of-care measurements alone.
Topics: Hemoglobinometry; Hemoglobins; Humans; Oximetry; Point-of-Care Systems; Spectrum Analysis
PubMed: 25943608
DOI: 10.1177/0310057X1504300310 -
Toxicon : Official Journal of the... Mar 2017Scorpion envenomation causes an autonomic storm resulting in changes in the vasoactive mediators' levels which lead to myocardial damage, cardiovascular disturbances,...
Scorpion envenomation causes an autonomic storm resulting in changes in the vasoactive mediators' levels which lead to myocardial damage, cardiovascular disturbances, peripheral circulatory failure, pulmonary edema, multi-system-organ-failure and death. The study aimed to determine the circulating levels of adrenaline, noradrenaline, angiotensin converting enzyme (ACE), Angiotensin II (Ang II), kallikrein enzyme, nitric oxide (NO), aldosterone, and electrolytes Na, K and Ca in scorpion envenomed children and to evaluate the potential relation between these vasoactive mediators, the severity of scorpion envenoming and the clinical outcome of envenomed children. Forty envenomed children (22 mild and 18 severe cases) along with 10 healthy control children were enrolled in the study. The circulating levels of adrenaline, noradrenaline, Ang II, ACE, kallikrein enzyme, and NO were determined by ELISA, and spectrophotometric assays on admission and 24 h later. On admission, serum aldosterone, and electrolytes; Na, K and Ca were determined by RIA, Flame photometer and Flame atomic absorption respectively. All envenomed children showed significant surge of adrenaline, noradrenaline, ACE, Ang II, aldosterone, NO and Na, that concomitantly faced by significant reduction in kallikrein, K and Ca on admission. Twenty four hours later, all envenomed children continued to show significant elevation of ACE, Ang II and NO. The severely envenomed children showed considerable reduction in circulating levels of adrenaline, noradrenaline, ACE and Ang II, while dramatic increase in kallikrein activity was reported in comparison to mildly envenomed children after 24 h of medical care. Also, NO exhibited considerable accumulation in non survivors, on admission, that was persistent for the subsequent 24 h and was accompanied by high kallikrein, low catecholamines and Ang II levels compared to survivors. Finally, the hypertensive cases showed substantial higher levels of catecholamine, ACE and Ang II, 24 h after admission. These findings indicated that, disturbances of the studied vasoactive mediators were common in scorpion envenomed children and may account for several inflammatory manifestations and clinical outcome. ACE inhibitors could be considered as possible therapeutic agent in victims with prominent increase in ACE and Ang II while kallikrein inhibitor and antioxidants may be effective in the treatment of late hypotensive ones.
Topics: Adolescent; Aldosterone; Angiotensin II; Animals; Child; Child, Preschool; Egypt; Electrolytes; Epinephrine; Female; Humans; Infant; Kallikreins; Male; Nitric Oxide; Peptidyl-Dipeptidase A; Scorpion Stings; Scorpion Venoms; Scorpions
PubMed: 28088475
DOI: 10.1016/j.toxicon.2017.01.006 -
Journal of Occupational and... Apr 2018This experimental study aimed to evaluate airborne particulates and volatile organic compounds (VOCs) from surgical smoke when a local exhaust ventilation (LEV) system...
This experimental study aimed to evaluate airborne particulates and volatile organic compounds (VOCs) from surgical smoke when a local exhaust ventilation (LEV) system is in place. Surgical smoke was generated from human tissue in an unoccupied operating room using an electrocautery surgical device for 15 min with 3 different test settings: (1) without LEV control; (2) control with a wall irrigation suction unit with an in-line ultra-low penetration air filter; and (3) control with a smoke evacuation system. Flow rate of LEVs was approximately 35 L/min and suction was maintained within 5 cm of electrocautery interaction site. A total of 6 experiments were conducted. Particle number and mass concentrations were measured using direct reading instruments including a condensation particle counter (CPC), a light-scattering laser photometer (DustTrak DRX), a scanning mobility particle sizer (SMPS), an aerodynamic particle sizer (APS), and a viable particle counter. Selected VOCs were collected using evacuated canisters using grab, personal and area sampling techniques. The largest average particle and VOCs concentrations were found in the absence of LEV control followed by LEV controls. Average ratios of LEV controls to without LEV control ranged 0.24-0.33 (CPC), 0.28-0.39 (SMPS), 0.14-0.31 (DustTrak DRX), and 0.26-0.55 (APS). Ethanol and isopropyl alcohol were dominant in the canister samples. Acetaldehyde, acetone, acetonitrile, benzene, hexane, styrene, and toluene were detected but at lower concentrations (<500 μg/m) and concentrations of the VOCs were much less than the National Institute for Occupational Safety and Health recommended exposure limit values. Utilization of the LEVs for surgical smoke control can significantly reduce but not completely eliminate airborne particles and VOCs.
Topics: Air Pollutants, Occupational; Electrocoagulation; Humans; Occupational Exposure; Particulate Matter; Smoke; Ventilation; Volatile Organic Compounds
PubMed: 29283318
DOI: 10.1080/15459624.2017.1422082 -
Indian Journal of Community Medicine :... 2018High sodium intake is a major public health concern. Sodium consumption pattern of West Indian population has never been reported before.
BACKGROUND
High sodium intake is a major public health concern. Sodium consumption pattern of West Indian population has never been reported before.
OBJECTIVES
The cross-sectional study assessed sodium intake pattern by considering all possible dietary sources and spot urine sodium estimation among sedentary healthy adults of productive age group (35-55 years).
MATERIALS AND METHODS
Twenty-four-h dietary recall (3 alternative days in a week), food frequency assessment, weighing of table, and cooking salt ( = 218) were performed. Spot urine samples were collected for subset ( = 33) to quantify sodium excretion. Flame photometer "CL 361" was used for food sodium quantification.
RESULTS
Men had higher sodium intake than women (3.9 ± 0.4 vs. 3.8 ± 0.4 g/day). Significantly higher sodium intake among men was from processed ready to eat foods (0.8 ± 0.3 vs. 0.6 ± 0.1, < 0.05) and among women was from cooking and table salt (2.6 ± 0.3 vs. 2.8 ± 0.3, < 0.001). Lowest quartile (<25 percentile) intake of oral sodium consumption (2.4 ± 0.5 g/day) was higher than WHO safe recommendation level of <2 g/day. Late afternoon spot urine sodium content was used to predict 24-h sodium excretion (6.1 ± 0.5 g/day), in turn population level sodium intake estimation. Analyzed sodium content of most frequently consumed all ready to eat foods was found to be higher than the reported values.
CONCLUSION
There is a strong need of evidence-based guidelines and policy formulation for national salt reduction program in India.
PubMed: 29899602
DOI: 10.4103/ijcm.IJCM_116_17 -
Clinical Ophthalmology (Auckland, N.Z.) 2016To evaluate short-term repeatability, intereye correlation, and effect of ocular dominance on macular pigment optical density (MPOD) measurements obtained using the...
PURPOSE
To evaluate short-term repeatability, intereye correlation, and effect of ocular dominance on macular pigment optical density (MPOD) measurements obtained using the QuantifEye Heterochromatic Flicker Photometer.
PATIENTS AND METHODS
A total of 72 study participants were enrolled in this prospective, cross-sectional study. Participants underwent a comprehensive ocular evaluation, including visual acuity, evaluation of ocular dominance, slit lamp examination, intraocular pressure measurement, and optic nerve head and macula analysis using optical coherence tomography and fundus photography. All study participants after initial training underwent MPOD measurement twice in both eyes in a randomized sequence. The repeatability was tested using Altman and Bland plots for first measurements with the second measurements for right eye and left eye and additionally by grouping eyes as a function of ocular dominance. The Pearson correlation coefficient was performed to assess the intereye correlation of MPOD values.
RESULTS
The mean age of study participants was 35.5 years (range 22-68 years). The mean MPOD measurements for OD (right eye) and OS (left eye) were 0.47 and 0.48, respectively, which followed a normal distribution (Shapiro-Wilk test, P=0.6 and 0.2). The 95% limits of agreement of Altman and Bland plots for the first and second measurements were -0.12 to +0.11 and -0.13 to +0.12 for OD and OS, respectively. The correlation coefficient of mean MPOD measurements of OD and OS was r statistic =0.94 (Pearson correlation coefficient P<0.0001; r (2) 0.89). The 95% limits of agreement of Altman and Bland plots when evaluated by laterality of eye or by ocular dominance were narrow, with limits of agreement ranging from -0.13 to +0.12.
CONCLUSION
The MPOD measurements obtained using the QuantifEye show good short-term repeatability. There is excellent intereye correlation, indicating that the MPOD values of one eye data can predict the fellow eye value with 89% accuracy. The ocular dominance had no bearing on the outcome of this psychophysical test in ocular healthy eyes.
PubMed: 27621586
DOI: 10.2147/OPTH.S111708 -
Environmental Science and Pollution... Jul 2017The detailed analysis of columnar optical and microphysical properties of aerosols obtained from the AErosol RObotic NETwork (AERONET) Cimel sun photometer operated at...
Characteristics of columnar aerosol optical and microphysical properties retrieved from the sun photometer and its impact on radiative forcing over Skukuza (South Africa) during 1999-2010.
The detailed analysis of columnar optical and microphysical properties of aerosols obtained from the AErosol RObotic NETwork (AERONET) Cimel sun photometer operated at Skukuza (24.98° S, 31.60° E, 150 m above sea level), South Africa was carried out using the level 2.0 direct sun and inversion products measured during 1999-2010. The observed aerosol optical depth (AOD) was generally low over the region, with high values noted in late winter (August) and mid-spring (September and October) seasons. The major aerosol types found during the study period were made of 3.74, 69.63, 9.34, 8.83, and 8.41% for polluted dust (PD), polluted continental (PC), non-absorbing (NA), slightly absorbing (SA), and moderately absorbing (MA) aerosols, respectively. Much attention was given to the aerosol fine- and coarse-modes deduced from the particle volume concentration, effective radius, and fine-mode volume fraction. The aerosol volume size distribution pattern was found to be bimodal with the fine-mode showing predominance relative to coarse-mode during the winter and spring seasons, owing to the onset of the biomass burning season. The mean values of total, fine-, and coarse-mode volume particle concentrations were 0.07 ± 0.04, 0.03 ± 0.03, and 0.04 ± 0.02 μm μm, respectively, whereas the mean respective effective radii observed at Skukuza for the abovementioned modes were 0.35 ± 0.17, 0.14 ± 0.02, and 2.08 ± 0.02 μm. The averaged shortwave direct aerosol radiative forcing (ARF) observed within the atmosphere was found to be positive (absorption or heating effect), whereas the negative forcing in the surface and TOA depicted significant cooling effect due to more scattering type particles.
Topics: Aerosols; Atmosphere; Dust; Environmental Monitoring; Photometry; Seasons; South Africa
PubMed: 28537035
DOI: 10.1007/s11356-017-9211-2 -
Environmental Science & Technology Feb 2016Approximately 150 billion cubic meters (BCM) of natural gas is flared and vented in the world annually, emitting greenhouse gases and other pollutants with no energy...
Approximately 150 billion cubic meters (BCM) of natural gas is flared and vented in the world annually, emitting greenhouse gases and other pollutants with no energy benefit. About 7 BCM per year is flared in the United States, and half is from North Dakota alone. There are few emission measurements from associated gas flares and limited black carbon (BC) emission factors have been previously reported from the field. Emission plumes from 26 individual flares in the Bakken formation in North Dakota were sampled. Methane, carbon dioxide, and BC were measured simultaneously, allowing the calculation of BC mass emission factors using the carbon balance method. Particle optical absorption was measured using a three-wavelength particle soot absorption photometer (PSAP) and BC particle number and mass concentrations were measured with a single particle soot photometer. The BC emission factors varied over 2 orders of magnitude, with an average and uncertainty range of 0.14 ± 0.12 g/kg hydrocarbons in associated gas and a median of 0.07 g/kg which represents a lower bound on these measurements. An estimation of the BC emission factor derived from PSAP absorption provides an upper bound at 3.1 g/kg. These results are lower than previous estimations and laboratory measurements. The BC mass absorption cross section was 16 ± 12 m(2)/g BC at 530 nm. The average absorption Ångström exponent was 1.2 ± 0.8, suggesting that most of the light absorbing aerosol measured was black carbon and the contribution of light absorbing organic carbon was small.
Topics: Aerosols; Air Pollutants; Carbon; Carbon Dioxide; Gases; Methane; Natural Gas; North Dakota; Oil and Gas Industry; Soot
PubMed: 26764563
DOI: 10.1021/acs.est.5b04712 -
Optics Express Jul 2018The General V(λ) Mismatch Index, f1 , was defined for a general description of the photometric performance of photometers. This index is widely-used in photometry, and...
The General V(λ) Mismatch Index, f1 , was defined for a general description of the photometric performance of photometers. This index is widely-used in photometry, and it is very relevant for selecting photometers for low-uncertainty photometric measurements. It quantifies the spectral mismatch between the relative spectral responsivity of a photometer and the luminous efficiency function for photopic vision, V(λ). The linear correlation between the real general photometric measurement error and f1 of 77 photometers was studied for four sets of light sources: R, G and B LEDs (narrowband spectral power distributions, SPDs), blackbodies at different colour temperatures (broadband SPDs), phosphor-based LEDs at different correlated color temperatures (SPDs with narrow- and broad-band features), and a mixture of blackbodies and phosphor-based LED sources. This article shows that it can be defined an alternative index which is notably better correlated with the real general photometric measurement error of the photometers under light sources with broadband features in their SPDs, adequate for general lighting. This index is based on filtering the high spectral frequencies variations between the relative spectral responsivity of the photometer and V(λ). The use of this new index for the assessment of the general photometric performance of photometers would improve the selection of high quality photometers and, consequently, would contribute to the general improvement of photometric measurements.
PubMed: 30114039
DOI: 10.1364/OE.26.018633 -
The Science of the Total Environment Jun 2022The research on the mechanism of combined air pollution in the Yangtze-Huaihe region, which is characterized by unique meteorological and geographical conditions and...
The research on the mechanism of combined air pollution in the Yangtze-Huaihe region, which is characterized by unique meteorological and geographical conditions and pollution emission characteristics, is still insufficient. We performed an experiment on key pollutants and an ozone formation study in Hefei, which is a pivotal city in the Yangtze-Huaihe region, from September 1 to 20, 2020. The aerosols retrieved via two-dimensional Multi-axis Differential Optical Absorption Spectroscopy (2D-MAX-DOAS) with a Boltzmann-shaped a priori profile had the best agreement with the results of Light Detection and Ranging (LIDAR) and sun-photometer measurements among the three typical a priori profiles (Gaussian, Boltzmann, and exponential shapes). The correlation coefficients of the near-surface gas concentrations retrieved using both 2D-MAX-DOAS and in situ measurements were 0.86 (NO) and 0.61 (HCHO). The high NO and HCHO concentrations were observed at azimuths of 180° and 315° at heights of 0.8-1.5 km, and they may have been emitted by aircrafts. Importantly, the ratio of HCHO to NO during a typical pollution episode revealed that the factors controlling the O formation changed with altitude: VOCs (surface) to NOx (0.4 km) to transition (1.0 km) to VOCs (1.6 km). Moreover, the effect of VOCs on the O generation was stronger than that of NOx, especially in the downtown area of Hefei. When the ratio of HCHO to NO was 3.55-7.46, the ozone concentration in Hefei could be controlled well, especially at the optimal value of 5.50.
Topics: Air Pollutants; China; Environmental Monitoring; Nitrogen Dioxide; Ozone
PubMed: 35090930
DOI: 10.1016/j.scitotenv.2022.153425