scholarly journals GC×GC measurements of C<sub>7</sub>-C<sub>11</sub> aromatic and n-alkane hydrocarbons on Crete, in air from Eastern Europe during the MINOS campaign

2003 ◽  
Vol 3 (5) ◽  
pp. 1461-1475 ◽  
Author(s):  
X. Xu ◽  
C. Williams ◽  
H. Plass-Dülmer ◽  
H. Berresheim ◽  
G. Salisbury ◽  
...  
Keyword(s):  
Rate Constants ◽  
Field Measurements ◽  
Early Morning ◽  
Reaction Model ◽  
Sequential Reaction ◽  
Related Data ◽  
Mixing Ratios ◽  
Ground Station ◽  
The Mean ◽  
The Relationship

Abstract. During the Mediterranean Intensive Oxidant Study (MINOS) campaign in August 2001 gas-phase organic compounds were measured using comprehensive two-dimensional gas chromatography (GCxGC) at the Finokalia ground station, Crete. In this paper, C7-C11 aromatic and n-alkane measurements are presented and interpreted. The mean mixing ratios of the hydrocarbons varied from 1±1 pptv (i-propylbenzene) to 43±36 pptv (toluene). The observed mixing ratios showed strong day-to-day variations and generally higher levels during the first half of the campaign. Mean diel profiles showed maxima at local midnight and late morning, and minima in the early morning and evening. Results from analysis using a simplified box model suggest that both the chemical sink (i.e. reaction with OH) and the variability of source strengths were the causes of the observed variations in hydrocarbon mixing ratios. The logarithms of hydrocarbon concentrations were negatively correlated with the OH concentrations integral over a day prior to the hydrocarbon measurements. Slopes of the regression lines derived from these correlations for different compounds are compared with literature rate constants for their reactions with OH. The slopes for most compounds agree reasonably well with the literature rate constants. A sequential reaction model has been applied to the interpretation of the relationship between ethylbenzene and two of its potential products, i.e. acetophenone and benzeneacetaldehyde. The model can explain the good correlation observed between [acetophenone]/[ethylbenzene] and [benzeneacetaldehyde]/[ethylbenzene]. The model results and field measurements suggest that the reactivity of benzeneacetaldehyde may lie between those of acetophenone and ethylbenzene and that the ratio between yields of acetophenone and benzeneacetaldehyde may be up to 28:1. Photochemical ages of trace gases sampled at Finokalia during the campaign are estimated using the sequential reaction model and related data. They lie in the range of about 0.5-2.5 days.

scholarly journals GC×&GC measurements of C<sub>7</sub>–C<sub>11</sub> aromatic and n-alkane hydrocarbons on Crete, in air from Eastern Europe during the MINOS campaign

2003 ◽  
Vol 3 (2) ◽  
pp. 1477-1513 ◽  
Author(s):  
X. Xu ◽  
J. Williams ◽  
C. Plass-Dülmer ◽  
H. Berresheim ◽  
G. Salisbury ◽  
...  
Keyword(s):  
Rate Constants ◽  
Field Measurements ◽  
Early Morning ◽  
Reaction Model ◽  
Sequential Reaction ◽  
Related Data ◽  
Mixing Ratios ◽  
Ground Station ◽  
The Mean ◽  
The Relationship

Abstract. During the Mediterranean Intensive Oxidant Study (MINOS) campaign in August 2001 gas-phase organic compounds were measured using comprehensive two-dimensional gas chromatography (GC×GC) at the Finokalia ground station, Crete. In this paper, C7–C11 aromatic and n-alkane measurements are presented and interpreted. The mean mixing ratios of the hydrocarbons varied from 1+/−1 pptv (i-propylbenzene) to 43+/−36 pptv (toluene). The observed mixing ratios showed strong day-to-day variations and generally higher levels during the first half of the campaign. Mean diel profiles showed maxima at local midnight and late morning, and minima in the early morning and evening. Results from analysis using a simplified box model suggest that both the chemical sink (i.e. reaction with OH) and the variability of source strengths were the causes of the observed variations in hydrocarbon mixing ratios. The logarithms of hydrocarbon concentrations were negatively correlated with the OH concentrations integral over a day prior to the hydrocarbon measurements. Slopes of the regression lines derived from these correlations for different compounds are compared with literature rate constants for their reactions with OH. The slopes for most compounds agree reasonably well with the literature rate constants. A sequential reaction model has been applied to the interpretation of the relationship between ethylbenzene and two of its potential products, i.e. acetophenone and benzeneacetaldehyde. The model can explain the good correlation observed between [acetophenone]/[ethylbenzene] and [benzeneacetaldehyde]/[ethylbenzene]. The model results and field measurements suggest that the reactivity of benzeneacetaldehyde may lie between those of acetophenone and ethylbenzene and that the ratio between yields of acetophenone and benzeneacetaldehyde may be up to 28:1. Photochemical ages of trace gases sampled at Finokalia during the campaign are estimated using the sequential reaction model and related data. They lie in the range of about 0.5–2.5 days.

Adrenal function of extremely premature infants in the first 5 days after birth

2019 ◽  
Vol 32 (4) ◽  
pp. 363-367 ◽  
Author(s):  
Sze M. Ng ◽  
Akinsola Ogundiya ◽  
Mohammed Didi ◽  
Mark A. Turner
Keyword(s):  
Regression Analysis ◽  
Multiple Regression Analysis ◽  
Multiple Regression ◽  
Premature Infants ◽  
Plasma Cortisol ◽  
Early Morning ◽  
Adrenal Function ◽  
Plasma Acth ◽  
The Mean ◽  
The Relationship

Abstract Background There is limited data on adrenal function in the early days after birth in extremely premature infants. The relationship between plasma adrenocorticotrophic (ACTH) and cortisol hormone is central to the integrity of the hypothalamic-pituitary-adrenal (HPA) axis yet there are no studies examining this relationship in prematurity. Methods The aim of this study was to examine the relationship between early morning plasma cortisol and ACTH concentrations during the first 5 days after birth in infants born at less than 28 weeks’ gestation and to identify any independent factors that determine plasma cortisol levels in these infants during extreme prematurity. We prospectively studied early morning plasma ACTH and cortisol concentrations in infants born below 28 weeks’ gestation during the first 5 days of birth. Plasma cortisol was measured without extraction, using DPC Immulite® 2000 using a solid phase 2 site chemiluminescent immunometric assay. ACTH was measured using a radioimmunoassay. Spearman’s correlation was used to examine the relationship between cortisol and ACTH. Multiple regression analysis was used to examine the relationship between plasma cortisol and clinical risk index for babies (CRIB) score, antenatal dexamethasone, mode of delivery and gestation. Results There were 95 infants (53 males) of mean gestation 25.3 ± 1.3 standard deviation (SD) (range 23–27 + 6) weeks. The mean birth weight was 809 ± 17.0 g. The mean plasma cortisol was 400.5 ± 42.6 nmol/L and the mean plasma ACTH was 4.5 ± 0.9 pmol/L. Early morning plasma cortisol correlated significantly with gestation (R = 0.4, p = 0.005). Early morning plasma ACTH did not correlate with early morning plasma cortisol (R = −0.12, p = 0.7). Multiple regression analysis showed that gestation was the only independent determinant of early morning plasma cortisol concentration (beta coefficient = −0.4, p = 0.04). Conclusions The relationship between early morning plasma ACTH and plasma cortisol is either not established or is impaired in infants of less than 28 weeks’ gestation in the first 5 days after birth. The plasma cortisol level is mainly determined by gestation and is not directly related to illness severity, antenatal steroids or plasma ACTH in these infants in the first 5 days after birth.

Multi-Center Calibration of the Second Reference Material for Thromboplastin, Rabbit, Plain, Coded CRM 149R

1991 ◽  
Vol 65 (03) ◽  
pp. 263-267 ◽  
Author(s):  
A M H P van den Besselaar ◽  
R M Bertina
Keyword(s):  
Reference Material ◽  
Standard Error ◽  
Standard Errors ◽  
Sensitivity Index ◽  
Long Term Stability ◽  
Significant Bias ◽  
The Mean ◽  
The Relationship ◽  
International Sensitivity Index

SummaryIn a collaborative trial of eleven laboratories which was performed mainly within the framework of the European Community Bureau of Reference (BCR), a second reference material for thromboplastin, rabbit, plain, was calibrated against its predecessor RBT/79. This second reference material (coded CRM 149R) has a mean International Sensitivity Index (ISI) of 1.343 with a standard error of the mean of 0.035. The standard error of the ISI was determined by combination of the standard errors of the ISI of RBT/79 and the slope of the calibration line in this trial.The BCR reference material for thromboplastin, human, plain (coded BCT/099) was also included in this trial for assessment of the long-term stability of the relationship with RBT/79. The results indicated that this relationship has not changed over a period of 8 years. The interlaboratory variation of the slope of the relationship between CRM 149R and RBT/79 was significantly lower than the variation of the slope of the relationship between BCT/099 and RBT/79. In addition to the manual technique, a semi-automatic coagulometer according to Schnitger & Gross was used to determine prothrombin times with CRM 149R. The mean ISI of CRM 149R was not affected by replacement of the manual technique by this particular coagulometer.Two lyophilized plasmas were included in this trial. The mean slope of relationship between RBT/79 and CRM 149R based on the two lyophilized plasmas was the same as the corresponding slope based on fresh plasmas. Tlowever, the mean slope of relationship between RBT/79 and BCT/099 based on the two lyophilized plasmas was 4.9% higher than the mean slope based on fresh plasmas. Thus, the use of these lyophilized plasmas induced a small but significant bias in the slope of relationship between these thromboplastins of different species.

Evaluation of the Efficacy of ST2 and NT-proBNP in the Diagnosis and Prediction of Short- Term Prognosis in Heart Failure with Reduced Ejection Fraction

2017 ◽  
Vol 9 (04) ◽  
Author(s):  
Shivananda B Nayak ◽  
Dharindra Sawh ◽  
Brandon Scott ◽  
Vestra Sears ◽  
Kareshma Seebalack ◽  
...  
Keyword(s):  
Heart Failure ◽  
Ejection Fraction ◽  
Cardiac Biomarkers ◽  
Double Blind Study ◽  
Short Term ◽  
Double Blind ◽  
Reduced Ejection Fraction ◽  
The Mean ◽  
Design And Methods ◽  
The Relationship

Purpose: i) To determine the relationship between the cardiac biomarkers ST2 and NT-proBNP with ejection fraction (EF) in heart failure (HF) patients. ii) Assess whether a superiority existed between the aforementioned cardiac markers in diagnosing the HF with reduced EF. iii) Determine the efficacy of both biomarkers in predicting a 30-day cardiovascular event and rehospitalization in patients with HF with reduced EF iv) To assess the influence of age, gender, BMI, anaemia and renal failure on the ST2 and NT-proBNP levels. Design and Methods: A prospective double-blind study was conducted to obtain data from a sample of 64 cardiology patients. A blood sample was collected to test for ST2 and NT-proBNP. An echocardiogram (to obtain EF value), electrocardiogram and questionnaire were also obtained. Results: Of the 64 patients enrolled, 59.4% of the population had an EF less than 40%. At the end of the 30- day period, 7 patients were warded, 37 were not warded, one died and 17 were non respondent. Both biomarkers were efficacious at diagnosing HF with a reduced EF. However, neither of them were efficacious in predicting 30-day rehospitalization. The mean NT-proBNP values being: not rehospitalized (2114.7486) and 30 day rehospitalization (1008.42860) and the mean ST2 values being: not rehospitalized (336.1975), and 30-day rehospitalization. (281.9657). Conclusion: Neither ST2 or NT-proBNP was efficacious in predicting the short- term prognosis in HF with reduced EF. Both however were successful at confirming the diagnosis of HF in HF patients with reduced EF.

scholarly journals Intraspecific Latitudinal Variation in Nest Orientation Among Ground-Nesting Passerines: A Study Using Published Data

The Condor ◽  
2007 ◽  
Vol 109 (2) ◽  
pp. 441-446 ◽  
Author(s):  
Niall H.K. Burton
Keyword(s):  
Early Morning ◽  
Published Data ◽  
Nest Entrance ◽  
Clear Trend ◽  
European Species ◽  
Statistical Comparison ◽  
Species Comparisons ◽  
Nest Microclimate ◽  
The Relationship ◽  
Ground Nesting

Abstract The relationship between nest entrance orientation and latitude among ground-nesting passerines was reviewed using published information. Data were collated for seven North American and European species. Pooling within-species comparisons, there was a clear trend from a preference for north-facing nests at lower latitudes to eastward- or southward-facing nests farther north. Orientations differed significantly in eight of 12 cases for which statistical comparison was possible, means differing in the expected direction in six of these cases. These results highlight how the influence of solar radiation on nest microclimate typically delineates preferred nest orientation in these species, i.e., at lower latitudes, the need for shade results in a preference for northward orientations; at mid latitudes, eastward orientations predominate, reflecting a probable balance between the benefits of warmth in the early morning and shade in the afternoon; while at high latitudes, nests may be oriented southward to gain warmth throughout the day.

scholarly journals Influence of chronotype on daily mood fluctuations: pilot study in patients with depression

BJPsych Open ◽  
2020 ◽  
Vol 6 (2) ◽  
Author(s):  
Konstantin F. Brückmann ◽  
Jürgen Hennig ◽  
Matthias J. Müller ◽  
Stanislava Fockenberg ◽  
Anne-Marthe Schmidt ◽  
...  
Keyword(s):  
Clinical Trials ◽  
Pilot Study ◽  
Negative Affect ◽  
Clinical Setting ◽  
Early Morning ◽  
Healthy Controls ◽  
Patient Subgroup ◽  
Depression Risk ◽  
Gender And Age ◽  
The Relationship

Summary Depression risk is associated with a late chronotype pattern often described as an ‘evening chronotype’. Fluctuations in mood over consecutive days have not yet been measured according to chronotype in in-patients with depression. A total of 30 in-patients with depression and 32 healthy controls matched for gender and age completed a chronotype questionnaire and twice-daily ratings on mood for 10 consecutive days (registered in the German Clinical Trials Register: DRKS00010215). The in-patients had Saturdays and Sundays as hospital-leave days. The relationship between chronotype and daily mood was mediated by the weekday–weekend schedule with higher levels of negative affect in the evening-chronotype patient subgroup at weekends. Results are discussed with respect to a probably advantageous standardised clinical setting with early morning routines, especially for patients with evening chronotypes.

Thermoregulatory responses to cold water at different times of day

1999 ◽  
Vol 87 (1) ◽  
pp. 243-246 ◽  
Author(s):  
John W. Castellani ◽  
Andrew J. Young ◽  
James E. Kain ◽  
Michael N. Sawka
Keyword(s):  
Cold Water ◽  
Water Immersion ◽  
Early Morning ◽  
Cold Water Immersion ◽  
Time Of Day ◽  
Mean Skin Temperature ◽  
Mean Body Temperature ◽  
Metabolic Heat ◽  
Body Temperature Change ◽  
The Mean

This study examined how time of day affects thermoregulation during cold-water immersion (CWI). It was hypothesized that the shivering and vasoconstrictor responses to CWI would differ at 0700 vs. 1500 because of lower initial core temperatures (Tcore) at 0700. Nine men were immersed (20°C, 2 h) at 0700 and 1500 on 2 days. No differences ( P > 0.05) between times were observed for metabolic heat production (M˙, 150 W ⋅ m−2), heat flow (250 W ⋅ m−2), mean skin temperature (T sk, 21°C), and the mean body temperature-change in M˙(ΔM˙) relationship. Rectal temperature (Tre) was higher ( P < 0.05) before (Δ = 0.4°C) and throughout CWI during 1500. The change in Tre was greater ( P < 0.05) at 1500 (−1.4°C) vs. 0700 (−1.2°C), likely because of the higher Tre-T skgradient (0.3°C) at 1500. These data indicate that shivering and vasoconstriction are not affected by time of day. These observations raise the possibility that CWI may increase the risk of hypothermia in the early morning because of a lower initial Tcore.

scholarly journals Correlation between fundus autofluorescence and visual function in patients with cone-rod dystrophy

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Satoru Kanda ◽  
Takumi Hara ◽  
Ryosuke Fujino ◽  
Keiko Azuma ◽  
Hirotsugu Soga ◽  
...  
Keyword(s):  
Visual Field ◽  
Significant Relationship ◽  
Fundus Autofluorescence ◽  
Univariate Analysis ◽  
Retrospective Chart Review ◽  
Mean Deviation ◽  
Wide Field ◽  
The Mean ◽  
The Relationship ◽  
Field Imaging

AbstractThis study aimed to investigate the relationship between autofluorescence (AF) signal measured with ultra-wide field imaging and visual functions in patients with cone-rod dystrophy (CORD). A retrospective chart review was performed for CORD patients. We performed the visual field test and fundus autofluorescence (FAF) measurement and visualized retinal structures with optical coherence tomography (OCT) on the same day. Using binarised FAF images, we identified a low FAF area ratio (LFAR: low FAF/30°). Relationships between age and logMAR visual acuity (VA), central retinal thickness (CRT), central choroidal thickness (CCT), mean deviation (MD) value, and LFAR were investigated. Thirty-seven eyes of 21 CORD patients (8 men and 13 women) were enrolled. The mean patient age was 49.8 years. LogMAR VA and MD were 0.52 ± 0.47 and − 17.91 ± 10.59 dB, respectively. There was a significant relationship between logMAR VA and MD (p = 0.001). LogMAR VA significantly correlated with CRT (p = 0.006) but not with other parameters. Conversely, univariate analysis suggested a significant relationship between MD and LFAR (p = 0.001). In the multivariate analysis, LFAR was significantly associated with MD (p = 0.002). In conclusion, it is useful to measure the low FAF area in patients with CORD. The AF measurement reflects the visual field deterioration but not VA in CORD.

Heart Rate and Neurological Outcomes in Patients Undergoing Targeted Temperature Management

2020 ◽  
pp. 088506662098250
Author(s):  
Chad M. Conner ◽  
William H. Perucki ◽  
Andre Gabriel ◽  
David M. O’Sullivan ◽  
Antonio B. Fernandez
Keyword(s):  
Heart Rate ◽  
Positive Association ◽  
Targeted Temperature Management ◽  
Temperature Management ◽  
Neurological Outcomes ◽  
Neurologic Outcomes ◽  
Resuscitation Guidelines ◽  
The Mean ◽  
The Impact ◽  
The Relationship

Introduction: There is a paucity of data evaluating the impact of heart rate (HR) during Targeted Temperature Management (TTM) and neurologic outcomes. Current resuscitation guidelines do not specify a HR goal during TTM. We sought to determine the relationship between HR and neurologic outcomes in a single-center registry dataset. Methods: We retrospectively studied 432 consecutive patients who completed TTM (33°C) after cardiac arrest from 2008 to 2017. We evaluated the relationship between neurologic outcomes and HR during TTM. Pittsburgh Cerebral Performance Categories (CPC) at discharge were used to determine neurological recovery. Statistical analysis included chi square, Student’s t-test and Mann-Whitney U. A logistic regression model was created to evaluate the strength of contribution of selected variables on the outcome of interest. Results: Approximately 94,000 HR data points from 432 patients were retrospectively analyzed; the mean HR was 82.17 bpm over the duration of TTM. Favorable neurological outcomes were seen in 160 (37%) patients. The mean HR in the patients with a favorable outcome was lower than the mean HR of those with an unfavorable outcome (79.98 bpm vs 85.67 bpm p < 0.001). Patients with an average HR of 60-91 bpm were 2.4 times more likely to have a favorable neurological outcome compared to than HR’s < 60 or > 91 (odds ratio [OR] = 2.36, 95% confidence interval [CI] 1.61-3.46, p < 0.001). Specifically, mean HR’s in the 73-82 bpm range had the greatest rate of favorable outcomes (OR 3.56, 95% CI 1.95-6.50), p < 0.001. Administration of epinephrine, a history of diabetes mellitus and hypertension all were associated with worse neurological outcomes independent of HR. Conclusion: During TTM, mean HRs between 60-91 showed a positive association with favorable outcomes. It is unclear whether a specific HR should be targeted during TTM or if heart rates between 60-91 bpm might be a sign of less neurological damage.

scholarly journals Relationship between 24-h venous blood glucose variation and mortality among patients with acute respiratory failure

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Xiaoling Zhang ◽  
Jingjing Zhang ◽  
Jiamei Li ◽  
Ya Gao ◽  
Ruohan Li ◽  
...  
Keyword(s):  
Blood Glucose ◽  
Respiratory Failure ◽  
Hospital Mortality ◽  
Acute Respiratory Failure ◽  
Venous Blood ◽  
Sensitivity Analyses ◽  
Icu Mortality ◽  
Logistic Regression Models ◽  
The Mean ◽  
The Relationship

AbstractEvidence indicates that glucose variation (GV) plays an important role in mortality of critically ill patients. We aimed to investigate the relationship between the coefficient of variation of 24-h venous blood glucose (24-hVBGCV) and mortality among patients with acute respiratory failure. The records of 1625 patients in the Multiparameter Intelligent Monitoring in Intensive Care II (MIMIC II) database were extracted. The 24-hVBGCV was calculated as the ratio of the standard deviation (SD) to the mean venous blood glucose level, expressed as a percentage. The outcomes included ICU mortality and in-hospital mortality. Participants were divided into three subgroups based on tertiles of 24-hVBGCV. Multivariable logistic regression models were used to evaluate the relationship between 24-hVBGCV and mortality. Sensitivity analyses were also performed in groups of patients with and without diabetes mellitus. Taking the lowest tertile as a reference, after adjustment for all the covariates, the highest tertile was significantly associated with ICU mortality [odds ratio (OR), 1.353; 95% confidence interval (CI), 1.018–1.797] and in-hospital mortality (OR, 1.319; 95% CI, 1.003–1.735), especially in the population without diabetes. The 24-hVBGCV may be associated with ICU and in-hospital mortality in patients with acute respiratory failure in the ICU, especially in those without diabetes.

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