Platelet Water Content is Decreased by Gel-Filtration

One approach to platelet sizing is to measure the intracellular water space of platelets with 3H-H2O since the % water content of platelets remains constant in states with different platelet sizes. Fresh citrated blood was centrifuged for 10 min at 150 'g' to obtain PRP. Aliquots of PRP were briefly incubated with either 3H-H2O or 14C-sucrose then layered over 0.3 ml dibutylphthalate and spun 4 min at 8000 'g'. The cell pellet was solubilized and counted to enable spaces to be calculated. The extracellular (sucrose) space was subtracted from the total water space of the pellet to give a mean intracellular water space of 0.56 ± 0.12 μ1/108 platelets (n =19). Assuming a water content of 7 5% and a density of 1.04, the mean platelet volume for normal subjects is 7.2 fl. Gel-filtration of platelets (GFP) on Sepharose-2B reduced their mean water space by 0.12 μl/108 platelets. However the amount of shrinkage on gel-filtration depended on the initial water space of the platelets in PRP and there was a linear relation between these two variables (r = 0.82). Shrinkage was 40% for an initial platelet water space of 0.70 μl/108 platelets but there was almost no shrinkage below a water space of 0.40 μl/108 platelets. Recovery of platelets from each column averaged 8 0% and showed no relation to the reduction in the mean cell water space. The lower water space of GFP may indicate a reduction in mean cell volume due to gel-filtration.

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Study on the Mechanical Criterion of Ice Lens Formation Based on Pore Size Distribution

Applied Sciences ◽

10.3390/app10248981 ◽

2020 ◽

Vol 10 (24) ◽

pp. 8981

Author(s):

Yuhang Liu ◽

Dongqing Li ◽

Lei Chen ◽

Feng Ming

Keyword(s):

Pore Size Distribution ◽

Pore Size ◽

Water Content ◽

Size Distribution ◽

Initial Water Content ◽

Mean Stress ◽

Initial Water ◽

Unfrozen Water Content ◽

The Mean ◽

Lens Formation

Ice lens is the key factor which determines the frost heave in engineering construction in cold regions. At present, several theories have been proposed to describe the formation of ice lens. However, most of these theories analyzed the ice lens formation from a macroscopic view and ignored the influence of microscopic pore sizes and structures. Meanwhile, these theories lacked the support of measured data. To solve this problem, the microscopic crystallization stress was converted into the macro mean stress through the principle of statistics with the consideration of pore size distribution. The mean stress was treated as the driving force of the formation of ice lens and induced into the criterion of ice lens formation. The influence of pore structure and unfrozen water content on the mean stress was analyzed. The results indicate that the microcosmic crystallization pressure can be converted into the macro mean stress through the principle of statistics. Larger mean stress means the ice lens will be formed easier in the soil. The mean stress is positively correlated with initial water content. At the same temperature, an increase to both the initial water content and the number of pores can result in a larger mean stress. Under the same initial water content, mean stress increases with decreasing temperature. The result provides a theoretical basis for studying ice lens formation from the crystallization theory.

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Interaction of soil water and groundwater during the freezing–thawing cycle: field observations and numerical modeling

Hydrology and Earth System Sciences ◽

10.5194/hess-25-4243-2021 ◽

2021 ◽

Vol 25 (8) ◽

pp. 4243-4257

Author(s):

Hong-Yu Xie ◽

Xiao-Wei Jiang ◽

Shu-Cong Tan ◽

Li Wan ◽

Xu-Sheng Wang ◽

...

Keyword(s):

Numerical Modeling ◽

Water Content ◽

Soil Water ◽

Water Table ◽

Groundwater Level ◽

Water Table Depth ◽

Field Observations ◽

Initial Water ◽

Groundwater Inflow ◽

The Mean

Abstract. Freezing-induced groundwater-level decline is widely observed in regions with a shallow water table, but many existing studies on freezing-induced groundwater migration do not account for freezing-induced water-level fluctuations. Here, by combining detailed field observations of liquid soil water content and groundwater-level fluctuations at a site in the Ordos Plateau, China, and numerical modeling, we showed that the interaction of soil water and groundwater dynamics was controlled by wintertime atmospheric conditions and topographically driven lateral groundwater inflow. With an initial water table depth of 120 cm and a lateral groundwater inflow rate of 1.03 mm d−1, the observed freezing and thawing-induced fluctuations of soil water content and groundwater level are well reproduced. By calculating the budget of groundwater, the mean upward flux of freezing-induced groundwater loss is 1.46 mm d−1 for 93 d, while the mean flux of thawing-induced groundwater recharge is as high as 3.94 mm d−1 for 32 d. These results could be useful for local water resources management when encountering seasonally frozen soils and for future studies on two- or three-dimensional transient groundwater flow in semi-arid and seasonally frozen regions. By comparing models under a series of conditions, we found the magnitude of freezing-induced groundwater loss decreases with initial water table depth and increases with the rate of groundwater inflow. We also found a fixed-head lower boundary condition would overestimate freezing-induced groundwater migration when the water table depth is shallow. Therefore, an accurate characterization of freezing-induced water table decline is critical to quantifying the contribution of groundwater to hydrological and ecological processes in cold regions.

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Humidification of Respired Gas by Nasal Mucosa

Annals of Otology Rhinology & Laryngology ◽

10.1177/000348947308200310 ◽

1973 ◽

Vol 82 (3) ◽

pp. 330-332 ◽

Cited By ~ 4

Author(s):

W. Liese ◽

R. Joshi ◽

G. Cumming

Keyword(s):

Nasal Mucosa ◽

Normal Subjects ◽

Total Water ◽

Tidal Water ◽

Complete Saturation ◽

Expired Gas ◽

The Mean ◽

The Difference ◽

End Tidal ◽

Average Contribution

End tidal water vapor tension of the expirate after nasal and then after oral inspiration was measured at the lips of seven normal subjects using a mass spectrometer. At a mean inspired air temperature of 23°C and Ph.o of 14.7 mmHg, the mean end tidal Ph.o was was 40.57 mmHg after nasal and 37.15 mmHg after oral inspiration. The difference was statistically significant. The evidence for complete saturation of expired gas is discussed. Assuming a 100% saturation of expired gas the average contribution of the nasal mucosa to the water content of the respired air in this experiment was 3 gm/m3 or approximately 10% of the total water contributed by the respiraory tract.

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Estimation of specific hepatic arterial water space

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.1998.275.2.g228 ◽

1998 ◽

Vol 275 (2) ◽

pp. G228-G236

Author(s):

Selma Sahin ◽

Malcolm Rowland

Keyword(s):

Mean Transit Time ◽

Total Water ◽

Flow Conditions ◽

Bicarbonate Buffer ◽

Flow Rates ◽

Common Space ◽

The Common ◽

The Mean ◽

Water Space

The aim of this study was to estimate the specific arterial water space and associated blood flow using statistical moments of the frequency versus time outflow profile, with a model with specific spaces for hepatic arterial (HA) and portal venous (PV) flows in parallel with a common space. Studies were performed in the in situ dual-perfused rat liver ( n = 6–10), using Krebs-bicarbonate buffer with constant PV flow (12 ml/min) and various HA flow rates (3–6 ml/min). An impulse input-output technique was employed, varying the route of input, using [14C]urea as the reference indicator. Regardless of flow conditions, the frequency outflow profile after HA input was flatter and broader and the mean transit time longer than after PV input. Excellent recovery of marker was obtained in all cases. Applying the above model, the specific arterial space was estimated to be 9.7 ± 2.3 of total water space and receives ∼17% of the HA flow, with the remainder mixing with portal blood in the common space. The estimated total water content of liver (0.67–0.72 ml/g liver) agrees well with that determined by desiccation (0.72 ± 0.01 ml/g liver).

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A new sample collection method for the assessment of the percentage of water absorbed in frozen and quick-frozen poultry cuts (chicken breasts with skin)

Analytical Methods ◽

10.1039/c6ay00890a ◽

2016 ◽

Vol 8 (39) ◽

pp. 7080-7086

Author(s):

Leonardo Rodrigo Fonseca Tigre Maia ◽

Sergio Borges Mano ◽

Eliane Teixeira Mársico ◽

Carlos Adam Conte Júnior ◽

Carlos Frederico Marques Guimarães ◽

...

Keyword(s):

Water Content ◽

Total Water Content ◽

Total Water ◽

Sample Collection ◽

Protein Ratio ◽

Collection Method ◽

The Mean

The determination of the mean physiological water/protein ratio of samples obtained from homogenized poultry cuts using a powerful mincer is an efficient way of determining their total water content.

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Instant 99mTc-Labelled Glucoheptonate Kit for Kidney Imaging

Nuklearmedizin ◽

10.1055/s-0038-1624139 ◽

1983 ◽

Vol 22 (05) ◽

pp. 246-250 ◽

Cited By ~ 2

Author(s):

M. Al-Hilli ◽

H. M. A. Karim ◽

M. H. S. Al-Hissoni ◽

M. N. Jassim ◽

N. H. Agha

Keyword(s):

Sodium Hydroxide Solution ◽

Normal Subjects ◽

Organ Distribution ◽

Stable Complex ◽

Scintillation Camera ◽

Ph Adjustment ◽

The Mean ◽

The Stability ◽

Kidney Imaging ◽

Mean Concentration

Gelchromatography column scanning has been used to study the fractions of reduced hydrolyzed 99mTc, 99mTc-pertechnetate and 99mTc-chelate in a 99mTc-glucoheptonate (GH) preparation. A stable high labelling yield of 99mTc-GH complex in the radiopharmaceutical has been obtained with a concentration of 40-50 mg of glucoheptonic acid-calcium salt and not less than 0.45 mg of SnCl2 2 H2O at an optimal pH between 6.5 and 7.0. The stability of the complex has been found significantly affected when sodium hydroxide solution was used for the pH adjustment. However, an alternative procedure for final pH adjustment of the preparation has been investigated providing a stable complex for the usual period of time prior to the injection. The organ distribution and the blood clearance data of 99mTc-GH in rabbits were relatively similar to those reported earlier. The mean concentration of the radiopharmaceutical in both kidneys has been studied in normal subjects for one hour with a scintillation camera and the results were satisfactory.

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A COMPARISON OF TWO METHODS FOR MEASUREMENT OF ALDOSTERONE SECRETION RATE IN MAN

Acta Endocrinologica ◽

10.1530/acta.0.0530177 ◽

1966 ◽

Vol 53 (2) ◽

pp. 177-188 ◽

Cited By ~ 4

Author(s):

P. Lund-Johansen ◽

T. Thorsen ◽

K. F. Støa

Keyword(s):

Urinary Excretion ◽

Normal Subjects ◽

Secretion Rate ◽

Aldosterone Secretion ◽

Simple Method ◽

Mean Values ◽

Pathological Conditions ◽

Significant Difference ◽

Derivative Method ◽

The Mean

ABSTRACT A comparison has been made between (A), a relatively simple method for the measurement of aldosterone secretion rate, based on paper chromatography and direct densitometry of the aldosterone spot and (B) a more elaborate isotope derivative method. The mean secretion rate in 9 normal subjects was 112 ± 26 μg per 24 hours (method A) and 135 ± 35 μg per 24 hours (method B). The »secretion rate« in one adrenalectomized subject after the intravenous injection of 250 μg of aldosterone was 230 μg per 24 hours (method A) and 294 μg per 24 hours (method B). There was no significant difference in the mean values, and correlation between the two methods was good (r = 0.80). It is concluded that the densitometric method is suitable for clinical purposes as well as research, being more rapid and less expensive than the isotope derivative method. Method A also measures the urinary excretion of the aldosterone 3-oxo-conjugate, which is of interest in many pathological conditions. The densitometric method is obviously the less sensitive and a prerequisite for its use is an aldosterone secretion of 20—30 μg per 24 hours. Lower values are, however, rare in adults.

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EARLY VARIATIONS OF PLASMA CORTISOL AFTER PULSE INTRAVENOUS INJECTION OF DIBUTYRYL CYCLIC ADENOSINE 3′,5′-MONOPHOSPHATE IN NORMAL SUBJECTS

Acta Endocrinologica ◽

10.1530/acta.0.0720753 ◽

1973 ◽

Vol 72 (4) ◽

pp. 753-761 ◽

Cited By ~ 3

Author(s):

Alberto Angeli ◽

Giuseppe Boccuzzi ◽

Roberto Frajria ◽

Daniela Bisbocci ◽

Franco Ceresa

Keyword(s):

Intravenous Injection ◽

Plasma Cortisol ◽

Time Course ◽

Healthy Adult ◽

Normal Subjects ◽

Adult Women ◽

Healthy Women ◽

Adrenal Steroidogenesis ◽

The Mean ◽

Zero Time

ABSTRACT 10 mg/kg of dibutyryl cyclic adenosine 3′,5′-monophosphate (Db-cAMP) was iv pulse injected into twelve healthy adult women. The plasma cortisol levels were determined as 11-OHCS at zero time and then at 2.5, 5, 7.5, 10, 15, 30, 60 and 180 min after the injection. The data were compared with those obtained at the corresponding times in two groups of eleven and seventeen healthy women after the injection of 250 ng and 250 μg of synthetic β-1-24 corticotrophin performed in the same manner as the injection of the nucleotide. The mean increments in plasma cortisol were significantly lower after Db-cAMP than after ACTH. Differences were noted by analyzing the time course of the responses. In the case of stimulation with Db-cAMP the 11-OHCS levels rose progressively to a maximum at 15–30 min. By contrast, a peak of plasma cortisol was evident in most cases within a few min after the injection of ACTH; after a fall, a later rise was then observed starting from 15 min. The differences in the plasma 11-OHCS responses after the two stimuli may also be of interest clinically for the investigation of some aspects of adrenal steroidogenesis.

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