Regional differences in pleural lymphatic albumin concentration in sheep

1987 ◽  
Vol 252 (1) ◽  
pp. H64-H70 ◽  
Author(s):  
K. H. Albertine ◽  
E. L. Schultz ◽  
J. P. Wiener-Kronish ◽  
N. C. Staub
Keyword(s):  
Hydrostatic Pressure ◽  
Regional Differences ◽  
Left Lung ◽  
Vertical Gradient ◽  
Dark Field ◽  
Vertical Position ◽  
Albumin Concentration ◽  
The Difference ◽  
Field Reflectance ◽  
Vertical Height

We used quantitative reflectance autoradiography to compare the concentration of albumin in visceral pleural lymphatics at the cranial and caudal ends of the sheep's lung in the vertical (60 degrees head-up) and horizontal (supine) positions. Twelve to fourteen hours after injecting 125I-albumin intravenously we placed four anesthetized sheep in the vertical position to establish a microvascular hydrostatic pressure gradient along the vertical height of the lung. We placed two anesthetized sheep in the horizontal position. Four hours later, we fixed the left lung and removed visceral pleural tissue blocks from the cranial and caudal ends, separated by a 15-cm distance, along the costovertebral margin. We measured the silver grain density in the pleural lymphatic autoradiograms by dark-field reflectance microspectrophotometry. In the vertical position, the lymph albumin concentration at the cranial end (top) of the lung averaged 2.5 +/- 0.4 g/dl compared with the caudal end (bottom), which averaged 1.8 +/- 0.3 g/dl. The difference (42% greater at the top than the bottom) is significant (P less than 0.05). The computed gradient in perimicrovascular interstitial albumin osmotic pressure was 0.26 +/- 0.13 cmH2O/cm lung height. There were no differences between the cranial and caudal lymphatic groups in the two horizontal sheep. We conclude that in the sheep lung there is a gradient in perimicrovascular albumin concentration due to the vertical gradient in microvascular hydrostatic pressure.

Elevation gradient of intrathoracic pressure

1961 ◽  
Vol 16 (3) ◽  
pp. 465-468 ◽  
Author(s):  
John J. Krueger ◽  
Thomas Bain ◽  
John L. Patterson
Keyword(s):  
Pressure Gradient ◽  
Lung Tissue ◽  
Regional Differences ◽  
Work Of Breathing ◽  
Elevation Gradient ◽  
Intrathoracic Pressure ◽  
Vertical Gradient ◽  
Vertical Position ◽  
Horizontal Position ◽  
The Mean

Intrathoracic (intrapleural) pressure was measured in 15 anesthetized mongrel dogs held in the vertical position. A small balloon attached to a polyethylene catheter was inserted, without admission of air, into the chest through the 3rd intercostal space, or above the first rib, and passed down to the costophrenic sulcus. Along the lateral, anterolateral, and posterolateral aspects of the lung surface a vertical gradient of pressure was found, amounting to an increase of +0.21 cm H2O/cm descent, which was absent when the animal was in the horizontal position. This pressure gradient agrees closely with the gradient predicted on the basis of the mean density of lung tissue at end expiration in these animals. Among the implications of these findings is the possible existence of regional differences in the elastic work of breathing, based on differences in vertical distance between parts of the lung. Submitted on May 2, 1960

Removal of inelastically scattered electrons substantially increases phase contrast on frozen-hydrated molecules

1987 ◽  
Vol 45 ◽  
pp. 652-653
Author(s):  
John P. Langmore ◽  
Brian D. Athey
Keyword(s):  
Electron Diffraction ◽  
Phase Contrast ◽  
Low Dose ◽  
Dark Field ◽  
Biological Structure ◽  
Bright Field ◽  
Low Contrast ◽  
Negative Stain ◽  
The Difference ◽  
Better Than

Although electron diffraction indicates better than 0.3nm preservation of biological structure in vitreous ice, the imaging of molecules in ice is limited by low contrast. Thus, low-dose images of frozen-hydrated molecules have significantly more noise than images of air-dried or negatively-stained molecules. We have addressed the question of the origins of this loss of contrast. One unavoidable effect is the reduction in scattering contrast between a molecule and the background. In effect, the difference in scattering power between a molecule and its background is 2-5 times less in a layer of ice than in vacuum or negative stain. A second, previously unrecognized, effect is the large, incoherent background of inelastic scattering from the ice. This background reduces both scattering and phase contrast by an additional factor of about 3, as shown in this paper. We have used energy filtration on the Zeiss EM902 in order to eliminate this second effect, and also increase scattering contrast in bright-field and dark-field.

scholarly journals Regional differences in mortality rates during the COVID-19 epidemic in Italy

2020 ◽  
pp. 1-22
Author(s):  
Danila Azzolina ◽  
Giulia Lorenzoni ◽  
Luciano Silvestri ◽  
Ilaria Prosepe ◽  
Paola Berchialla ◽  
...  
Keyword(s):  
Regional Differences ◽  
Southern Italy ◽  
Meta Analysis ◽  
Analysis Data ◽  
Mortality Rates ◽  
Northern Italy ◽  
Admission Rates ◽  
Considerable Impact ◽  
The Difference ◽  
Disease Diffusion

Abstract Objective The COVID-19 outbreak started in Italy on February 20th, 2020, and has resulted in many deaths and intensive care unit (ICU) admissions. This study aimed to illustrate the epidemic COVID-19 growth pattern in Italy by considering the regional differences in disease diffusion during the first three months of the epidemic. Study design and methods Official COVID-19 data were obtained from the Italian Civil Protection Department of the Council of Ministers Presidency. The mortality and ICU admission rates per 100 000 inhabitants were calculated at the regional level and summarized via a Bayesian multilevel meta-analysis. Data were retrieved until April 21st, 2020. Results The highest cumulative mortality rates per 100 000 inhabitants were observed in northern Italy, particularly in Lombardia (85.3, 95% credibility intervals [CI] 75.7–94.7). The difference in the mortality rates between northern and southern Italy increased over time, reaching a difference of 67.72 (95% CI = 66–67) cases on April 2nd. Conclusions Northern Italy showed higher and increasing mortality rates during the first three months of the epidemic. The uncontrolled virus circulation preceding the infection spreading in southern Italy had a considerable impact on system burnout. This experience demonstrates that preparedness against the pandemic is of crucial importance to contain its disruptive effects.

scholarly journals Research on the Spatial Distribution Difference of Compulsory Education between China and Australia

2020 ◽  
Vol 15 (04) ◽  
pp. 129
Author(s):  
Saidong Lv ◽  
Yujun Pan
Keyword(s):  
Spatial Distribution ◽  
Regional Differences ◽  
Analytical Approach ◽  
Compulsory Education ◽  
Regional Data ◽  
Inductive Approach ◽  
Similarities And Differences ◽  
The Difference ◽  
Regional Imbalance ◽  
Analyze Data

This study collected regional data from 31 provinces in China and 8 states and territories in Australia in 2016. The study used the descriptive and analytical approach to analyze the results. Also, it used the inductive approach, the descriptive statics analysis and the SPSS to analyze data. it found that the distribution of compulsory education bears both similarities and differences in the two countries. In terms of similarities,there are certain regional differences in the teachers’ faculty of compulsory education in the two countries, and an unbalanced distribution of teachers has emerged. The difference is that although China's compulsory education has rqpidly, the teachers and funds of compulsory education lag far behind Australia, and the Regional imbalance is more serious in China than that in Australia.In other words, if there is a rapidly increasing population somewhere, and the nuers of teachers aren’t keeping up with this in China.

Mechanism of Stress-Enhanced Solid-Phase Epitaxy

1991 ◽  
Vol 237 ◽  
Author(s):  
T. K. Chaki
Keyword(s):  
Hydrostatic Pressure ◽  
Point Defects ◽  
Solid Phase ◽  
Amorphous Solid ◽  
Amorphous Layer ◽  
Crystalline Phases ◽  
Self Diffusion ◽  
Bending Stresses ◽  
Enhanced Mobility ◽  
The Difference

ABSTRACTEnhancement of solid-phase epitaxial growth (SPEG) due to hydrostatic pressures and bending stresses is explained by stress-enhanced mobility of point defects in the amorphous solid. The crystallization is by the adjustment of atomic positions in the vicinity of the crystallization/amorphous (c-a) interface due to self-diffusion in the amorphous phase, assisted by a free energy decrease equal to the difference in free energies between the amorphous and crystalline phases. Due to a mismatch in the bulk moduli between the amorphous and crystalline phases, the application of a hydrostatic pressure can develop tensile stresses in the amorphous layer near the c-a interface. Non-hydrostatic stresses in the amorphous layer enhance the mobility of point defects in the amorphous layer and, therefore, an enhancement of the SPEG rate. In the cases of both hydrostatic pressure and bending, the enhancement occurs in the tensile side, indicating that vacancy-like mechanism is predominant in SPEG.

Simulation of the vertical gradient of transpulmonary pressure by stable foams

1986 ◽  
Vol 61 (3) ◽  
pp. 1221-1225
Author(s):  
D. O. Warner ◽  
K. Rehder ◽  
R. E. Hyatt
Keyword(s):  
Hydrostatic Pressure ◽  
Elastic Properties ◽  
Transpulmonary Pressure ◽  
Vertical Gradient ◽  
Pressure Gradients ◽  
Histological Changes ◽  
Stable Foam ◽  
Dynamic Conditions ◽  
Regional Lung ◽  
Over Time

We describe a simulation of the vertical gradient of transpulmonary pressure (VGTP) using a stable foam, which is suitable for use in studies of the effect of the VGTP on excised lungs. We generated foams that produced linear hydrostatic pressure gradients (HPGs) from 0.18 to 0.44 cmH2O/cm depth, which were stable over time and were reproducible. The HPG was similar under static and dynamic conditions. The foam did not affect lung elastic properties or cause histological changes. We conclude that these stable foams provide a practical, inexpensive simulation of the VGTP and should be useful in studying the effects of the VGTP on regional lung behavior.

Effect of body position on regional diaphragm function in dogs

1990 ◽  
Vol 69 (6) ◽  
pp. 2296-2302 ◽  
Author(s):  
J. Sprung ◽  
C. Deschamps ◽  
S. S. Margulies ◽  
R. D. Hubmayr ◽  
J. R. Rodarte
Keyword(s):  
Prone Position ◽  
Regional Differences ◽  
Body Position ◽  
Vertical Gradient ◽  
Transdiaphragmatic Pressure ◽  
Lung Capacity ◽  
Volume Relationship ◽  
Residual Capacity ◽  
Fractional Shortening

The in situ lengths of muscle bundles of the crural and three regions of the costal diaphragm between origin and insertion were determined with a video roentgenographic technique in dogs. At total lung capacity (TLC) in both the prone and supine positions, the length of the diaphragm is not significantly different from the unstressed excised length, suggesting that the diaphragm is not under tension at TLC and that there is a hydrostatic gradient of pleural pressure on the diaphragmatic surface. Except for the ventral region of the costal diaphragm, which does not change length at lung volumes greater than 70% TLC, all other regions are stretched during passive deflations from TLC. Therefore below TLC the diaphragm is under passive tension and supports a transdiaphragmatic pressure (Pdi). The length of the diaphragm relative to its unstressed length is not uniform at functional residual capacity (FRC) and does not follow a strict vertical gradient that reverses when the animal is changed from the supine to the prone position. By inference, the length of muscle bundles is determined by factors other than the vertical gradient of Pdi. During mechanical ventilation, regional shortening is identical to the passive deflation length-volume relationship near FRC. Prone and supine FRC is the same, but the diaphragm is slightly shorter in the prone position. In both positions, during spontaneous ventilation there are no consistent differences in regional fractional shortening, despite regional differences in initial length relative to unstressed length.

Screening for microalbuminuria in patients with diabetes mellitus: frozen storage of urine samples decreases their albumin content.

1989 ◽  
Vol 35 (2) ◽  
pp. 308-310 ◽  
Author(s):  
L D Elving ◽  
J A Bakkeren ◽  
M J Jansen ◽  
C M de Kat Angelino ◽  
E de Nobel ◽  
...  
Keyword(s):  
Frozen Storage ◽  
Urine Samples ◽  
Diabetic Patients ◽  
Albumin Concentration ◽  
Low Concentrations ◽  
Albumin Content ◽  
Patients With Diabetes ◽  
The Difference ◽  
Urinary Albumin Concentration

Abstract The influence of storage on urinary albumin concentration was prospectively studied with use of overnight urine specimens (Albustix negative) from 73 diabetic patients. From each urine sample four aliquots were taken. One was stored at 4 degrees C and assayed within two weeks, the other three were stored at -20 degrees C and assayed within two weeks and after two and six months. Albumin concentration was measured with laser immunonephelometry. The detection limit, 1 mg/L, suffices for the screening of diabetic patients for microalbuminuria. After storage for two and six months at -20 degrees C, significantly lower albumin concentrations were found. The difference was mainly caused by lower concentrations found in urine samples in which a precipitate had formed, which was the case in 22 and 25 samples, respectively. Thus, freezing of urine samples for determination of low concentrations of albumin may yield falsely low results. Urine samples are best stored at 4 degrees C and assayed within two weeks.

Regional lung water and hematocrit determined by positron emission tomography

1985 ◽  
Vol 59 (3) ◽  
pp. 860-868 ◽  
Author(s):  
D. P. Schuster ◽  
M. A. Mintun ◽  
M. A. Green ◽  
M. M. Ter-Pogossian
Keyword(s):  
Positron Emission Tomography ◽  
Regional Distribution ◽  
Vertical Gradient ◽  
Emission Tomography ◽  
Lung Water ◽  
Average Value ◽  
Positron Emission ◽  
Significant Difference ◽  
Regional Basis ◽  
The Difference

We have measured with positron emission tomography (PET) the regional distribution of extravascular lung water (EVLW) and hematocrit (HctL) in normal supine dogs. H2(15)O and C15O were used as total lung water (TLW) and intravascular water (IVW) compartment labels, respectively. An additional plasma volume label (68Ga-transferrin) was used to determine regional HctL. EVLW was calculated as the difference between TLW and IVW. In 13 dogs, EVLW was relatively constant along a gravity-dependent vertical gradient, although values in the most anterior regions were statistically less (P less than 0.05) than those in more posterior ones. The average value for EVLW (13 dogs) was 14.4 +/- 2.5 ml H2O/100 ml lung. When EVLW was compared with IVW on a regional basis, the EVLW/IVW ratio decreased significantly in a gravity-dependent direction from 1.95 +/- 0.28 to 0.88 +/- 0.18. In 7 dogs, no significant difference between HctL and systemic hematocrit (average ratio 1.01 +/- 0.08) was found nor was any significant variation of HctL within the lung detected. Thus, in contrast to gravimetric techniques, a hematocrit correction does not appear to be necessary when regional EVLW is studied by PET.

Research on Regional Differences and Convergence of Energy Efficiency in China

2011 ◽  
Vol 347-353 ◽  
pp. 3952-3955 ◽  
Author(s):  
Jian Sheng Zhang
Keyword(s):  
Energy Efficiency ◽  
Convergence Analysis ◽  
Regional Differences ◽  
Western Region ◽  
Input Output ◽  
The West ◽  
Regional Energy ◽  
The Difference ◽  
Convergence Trend ◽  
Output Indicators

Basing on the input-output indicators, this paper analysed the regional energy efficiency of China by DEA model. The results showed: the energy efficiency in each region of China continues to be improved, but the rising speed was slow; the difference of energy efficiency in each region was great, specifically speaking, the east was the best and the middle was better and the west was the worst; from the convergence analysis on energy efficiency, it indicated that there was a convergence trend on energy efficiency in each region of China, and the eastern and middle regions were convergence, but it was divergent in the western region.

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