Transport of fluid and solutes in the body II. Model validation and implications

1999 ◽  
Vol 277 (3) ◽  
pp. H1228-H1240 ◽  
Author(s):  
C. C. Gyenge ◽  
B. D. Bowen ◽  
R. K. Reed ◽  
J. L. Bert
Keyword(s):  
Experimental Data ◽  
Companion Paper ◽  
Ringer Solution ◽  
The Body ◽  
Whole Body ◽  
Ion Distribution ◽  
Yield Information ◽  
Capillary Membrane ◽  
System Variables ◽  
Saline Solutions

A mathematical model of short-term whole body fluid, protein, and ion distribution and transport developed earlier [see companion paper: C. C. Gyenge, B. D. Bowen, R. K. Reed, and J. L. Bert. Am. J. Physiol. 277 ( Heart Circ. Physiol. 46): H1215–H1227, 1999] is validated using experimental data available in the literature. The model was tested against data measured for the following three types of experimental infusions: 1) hyperosmolar saline solutions with an osmolarity in the range of 2,000–2,400 mosmol/l, 2) saline solutions with an osmolarity of ∼270 mosmol/l and composition comparable with Ringer solution, and 3) an isosmotic NaCl solution with an osmolarity of ∼300 mosmol/l. Good agreement between the model predictions and the experimental data was obtained with respect to the trends and magnitudes of fluid shifts between the intra- and extracellular compartments, extracellular ion and protein contents, and hematocrit values. The model is also able to yield information about inaccessible or difficult-to-measure system variables such as intracellular ion contents, cellular volumes, and fluid fluxes across the vascular capillary membrane, data that can be used to help interpret the behavior of the system.

Transport of fluid and solutes in the body I. Formulation of a mathematical model

1999 ◽  
Vol 277 (3) ◽  
pp. H1215-H1227 ◽  
Author(s):  
C. C. Gyenge ◽  
B. D. Bowen ◽  
R. K. Reed ◽  
J. L. Bert
Keyword(s):  
Protein Transport ◽  
Companion Paper ◽  
The Body ◽  
Whole Body ◽  
Ionic Exchange ◽  
Transport Parameters ◽  
Ion Distribution ◽  
Capillary Membrane ◽  
Fluid Compartments ◽  
Cellular Compartments

A compartmental model of short-term whole body fluid, protein, and ion distribution and transport is formulated. The model comprises four compartments: a vascular and an interstitial compartment, each with an embedded cellular compartment. The present paper discusses the assumptions on which the model is based and describes the equations that make up the model. Fluid and protein transport parameters from a previously validated model as well as ionic exchange parameters from the literature or from statistical estimation [see companion paper: C. C. Gyenge, B. D. Bowen, R. K. Reed, and J. L. Bert. Am. J. Physiol. 277 ( Heart Circ. Physiol. 46): H1228–H1240, 1999] are used in formulating the model. The dynamic model has the ability to simulate 1) transport across the capillary membrane of fluid, proteins, and small ions and their distribution between the vascular and interstitial compartments; 2) the changes in extracellular osmolarity; 3) the distribution and transport of water and ions associated with each of the cellular compartments; 4) the cellular transmembrane potential; and 5) the changes of volume in the four fluid compartments. The validation and testing of the proposed model against available experimental data are presented in the companion paper.

scholarly journals Whole-animal connectome and cell-type complement of the three-segmented Platynereis dumerilii larva

2020 ◽  
Author(s):  
Csaba Verasztó ◽  
Sanja Jasek ◽  
Martin Gühmann ◽  
Réza Shahidi ◽  
Nobuo Ueda ◽  
...  
Keyword(s):  
Network Architecture ◽  
Level Structure ◽  
Neuronal Cell ◽  
Cell Types ◽  
Companion Paper ◽  
The Body ◽  
Whole Body ◽  
Pigment Cells ◽  
Cell Type ◽  
Platynereis Dumerilii

AbstractNervous systems coordinate effectors across the body during movements. We know little about the cellular-level structure of synaptic circuits for such body-wide control. Here we describe the whole-body synaptic connectome and cell-type complement of a three-segmented larva of the marine annelid Platynereis dumerilii. We reconstructed and annotated over 1,500 neurons and 6,500 non-neuronal cells in a whole-body serial electron microscopy dataset. The differentiated cells fall into 180 neuronal and 90 non-neuronal cell types. We analyse the modular network architecture of the entire nervous system and describe polysynaptic pathways from 428 sensory neurons to four effector systems – ciliated cells, glands, pigment cells and muscles. The complete somatic musculature and its innervation will be described in a companion paper. We also investigated intersegmental differences in cell-type complement, descending and ascending pathways, and mechanosensory and peptidergic circuits. Our work provides the basis for understanding whole-body coordination in annelids.

A New Transient Bio-Heat Model of the Human Body

2005 ◽  
Author(s):  
M. Salloum ◽  
N. Ghaddar ◽  
K. Ghali
Keyword(s):  
Experimental Data ◽  
Current Model ◽  
The Body ◽  
Arterial System ◽  
System Model ◽  
Human Model ◽  
Whole Body ◽  
Physiological Data ◽  
Ambient Conditions ◽  
The Core

A new mathematical multi-segmented model based on an improved Stolwijk model is developed for predicting nude human thermal and regulatory responses within body segments and the environment. The passive model segments the body into the 15 cylindrical parts. Each body part is divided into four nodes of core, skin, artery blood, and vein blood. The body nodes interact with each other through convection, perfusion and conduction. In any body element, the blood exiting the arteries and flowing into the capillaries is divided into blood flowing in the core (exchanges heat by perfusion in the core) and blood flowing into the skin layer (exchanges heat by perfusion in the skin). The model calculates the blood circulation flow rates based on exact physiological data of Avolio [1], real dimensions, and anatomic positions of the arteries in the body. The circulatory system model takes into consideration the pulsatile blood flow in the macro arteries with its effect on the convective heat transport. The inclusion of calculated blood perfusion in both the tissue and the skin, based on the arterial system model and the heart rate is unique for the current model. The bio-heat human model is capable of predicting accurately nude human transient physiological responses such as the body’s skin, tympanic, and core temperatures, sweat rates, and the dry and latent heat losses from each body segment. The nude body model predictions are compared with published theoretical and experimental data at a variety of ambient conditions and activity. The current model agrees well with experimental data during transient hot exposures. The nude human model has an accuracy of less than 8% for the whole-body heat gains or losses and ±0.48°C for skin temperature values.

Validation of a Full Porcine Finite Element Model for Blast Induced TBI Using a Coupled Eulerian-Lagrangian Approach

2017 ◽  
Author(s):  
X. Gary Tan ◽  
Robert N. Saunders ◽  
Amit Bagchi
Keyword(s):  
Experimental Data ◽  
Shock Wave ◽  
Finite Element ◽  
Computational Models ◽  
Soft Tissues ◽  
Large Strain ◽  
Viscoelastic Model ◽  
The Body ◽  
Whole Body ◽  
Fe Model

Current understanding of blast induced traumatic brain injury (TBI) mechanisms is incomplete and limits the development of protective and therapeutic measures. Animal testing has been used as a surrogate for human testing. The correlation of animals to human responses is not well understood with a limited set of experimental data, because of ethical concerns and cost of live animal tests. The validated computational animal models can be used to supplement and improve the granularity of available data at a significantly reduced cost. A whole-body porcine high-fidelity computational model was developed based on the image data. The hyper-viscoelastic model was used for soft tissues to capture the rate dependence and large strain nonlinearity of the material. The shock wave interaction with a porcine subject in a shock tube was simulated using computational fluid dynamics (CFD) models, via a combination of 1-D, 2-D and 3-D numerical techniques. The shock wave loads were applied to the exterior of the porcine finite element (FE) model to simulate the pressure wave transmission through the body and capture its biomechanical response. The CFD and FE problems are solved using the explicit Eulerian and Lagrangian solvers, respectively, in the DoD Open Source code CoBi. The computational models were validated by comparing the simulation results with experimental data at specific instrumented locations. The predicted brain tissue stress-strain fields were used to determine the areas susceptible to blast induced TBI by using published mechanical injury thresholds. The validated porcine model can be used to better understand TBI and how injury in animals corresponds to injury in humans. The coupled Eurlerian and Lagrangian approaches developed in this paper can be extended to other simulations to improve the solution accuracy.

A Simple and Inexpensive Clinical Whole Body Counter

1976 ◽  
Vol 15 (05) ◽  
pp. 248-253
Author(s):  
A. K. Basu ◽  
S. K. Guha ◽  
B. N. Tandon ◽  
M. M. Gupta ◽  
M. ML. Rehani
Keyword(s):  
The Body ◽  
Whole Body ◽  
Vitro Assay ◽  
Body Counter ◽  
Optimum Parameters ◽  
Whole Body Counter ◽  
Single Detector ◽  
Background Index ◽  
Iodide Crystal

SummaryThe conventional radioisotope scanner has been used as a whole body counter. The background index of the system is 10.9 counts per minute per ml of sodium iodide crystal. The sensitivity and derived sensitivity parameters have been evaluated and found to be suitable for clinical studies. The optimum parameters for a single detector at two positions above the lying subject have been obtained. It has been found that for the case of 131I measurement it is possible to assay a source located at any point in the body with coefficient of variation less than 5%. To add to the versatility, a fixed geometry for in-vitro counting of large samples has been obtained. The retention values obtained by the whole body counter have been found to correlate with those obtained by in-vitro assay of urine and stool after intravenous administration of 51Cr-albumin.

Visualization of Invasion into the Body and Internal Diffusion of Nanoparticles

2008 ◽  
Vol 396-398 ◽  
pp. 569-572
Author(s):  
Fumio Watari ◽  
Shigeaki Abe ◽  
I.D. Rosca ◽  
Atsuro Yokoyama ◽  
Motohiro Uo ◽  
...  
Keyword(s):  
Biomedical Applications ◽  
Fluorescent Microscopy ◽  
The Body ◽  
Internal Diffusion ◽  
Whole Body ◽  
X Ray ◽  
Body Level ◽  
Organ Level ◽  
Level 2 ◽  
Internal Body

Nanoparticles may invade directly into the internal body through the respiratory or digestive system and diffuse inside body. The behavior of nanoparticles in the internal body is also essential to comprehend for the realization of DDS. Thus it is necessary to reveal the internal dynamics for the proper treatments and biomedical applications of nanoparticles. In the present study the plural methods with different principles such as X-ray scanning analytical microscope (XSAM), MRI and Fluorescent microscopy were applied to enable the observation of the internal diffusion of micro/nanoparticles in the (1) whole body level, (2) inner organ level and (3) tissue and intracellular level. Chemical analysis was also done by ICP-AES for organs and compared with the results of XSAM mapping.

scholarly journals Making the choice between bioelectrical impedance measures for body hydration status assessment

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Dmitry M. Davydov ◽  
Andrey Boev ◽  
Stas Gorbunov
Keyword(s):  
Body Schema ◽  
Bioelectrical Impedance ◽  
Information Criterion ◽  
The Body ◽  
Whole Body ◽  
Hydration Status ◽  
Status Assessment ◽  
Best Fitting ◽  
Body Compartments ◽  
Fitting In

AbstractSituational or persistent body fluid deficit (i.e., de- or hypo-hydration) is considered a significant health risk factor. Bioimpedance analysis (BIA) has been suggested as an alternative to less reliable subjective and biochemical indicators of hydration status. The present study aimed to compare various BIA models in the prediction of direct measures of body compartments associated with hydration/osmolality. Fish (n = 20) was selected as a biological model for physicochemically measuring proximate body compartments associated with hydration such as water, dissolved proteins, and non-osseous minerals as the references or criterion points. Whole-body and segmental/local impedance measures were used to investigate a pool of BIA models, which were compared by Akaike Information Criterion in their ability to accurately predict the body components. Statistical models showed that ‘volumetric-based’ BIA measures obtained in parallel, such as distance2/Rp, could be the best approach in predicting percent of body moisture, proteins, and minerals in the whole-body schema. However, serially-obtained BIA measures, such as the ratio of the reactance to resistance and the resistance adjusted for distance between electrodes, were the best fitting in predicting the compartments in the segmental schema. Validity of these results should be confirmed on humans before implementation in practice.

scholarly journals Integumentary Colour Allocation in the Stork Family (Ciconiidae) Reveals Short-Range Visual Cues for Species Recognition

Birds ◽  
2021 ◽  
Vol 2 (1) ◽  
pp. 138-146
Author(s):  
Eduardo J. Rodríguez-Rodríguez ◽  
Juan J. Negro
Keyword(s):  
Short Range ◽  
Visual Cues ◽  
Species Recognition ◽  
The Body ◽  
Whole Body ◽  
Divergent Evolution ◽  
Black And White ◽  
Extant Species ◽  
Chromatic Spectrum ◽  
Mixed Species Flocks

The family Ciconiidae comprises 19 extant species which are highly social when nesting and foraging. All species share similar morphotypes, with long necks, a bill, and legs, and are mostly coloured in the achromatic spectrum (white, black, black, and white, or shades of grey). Storks may have, however, brightly coloured integumentary areas in, for instance, the bill, legs, or the eyes. These chromatic patches are small in surface compared with the whole body. We have analyzed the conservatism degree of colouration in 10 body areas along an all-species stork phylogeny derived from BirdTRee using Geiger models. We obtained low conservatism in frontal areas (head and neck), contrasting with a high conservatism in the rest of the body. The frontal areas tend to concentrate the chromatic spectrum whereas the rear areas, much larger in surface, are basically achromatic. These results lead us to suggest that the divergent evolution of the colouration of frontal areas is related to species recognition through visual cue assessment in the short-range, when storks form mixed-species flocks in foraging or resting areas.

scholarly journals Comparison of superficial wound documentation using 2D forensic photography, 3D photogrammetry, Botscan© and VR with real-life examination

2021 ◽  
Vol 17 (3) ◽  
pp. 422-430
Author(s):  
Federico Massini ◽  
Lars Ebert ◽  
Garyfalia Ampanozi ◽  
Sabine Franckenberg ◽  
Lena Benz ◽  
...  
Keyword(s):  
Gold Standard ◽  
3D Visualization ◽  
Real Life ◽  
The Body ◽  
Whole Body ◽  
Forest Plot ◽  
Technical Documentation ◽  
Forensic Photography ◽  
Head Mounted Display ◽  
Significant Difference

AbstractEvidence acquisition, interpretation and preservation are essential parts of forensic case work that make a standardized documentation process fundamental. The most commonly used method for the documentation and interpretation of superficial wounds is a combination of two modalities: two-dimensional (2D) photography for evidence preservation and real-life examination for wound analysis. As technologies continue to develop, 2D photography is being enhanced with three-dimensional (3D) documentation technology. In our study, we compared the real-life examination of superficial wounds using four different technical documentation and visualization methods.To test the different methods, a mannequin was equipped with several injury stickers, and then the different methods were applied. A total of 42 artificial injury stickers were documented in regard to orientation, form, color, size, wound borders, wound corners and suspected mechanism of injury for the injury mechanism. As the gold standard, superficial wounds were visually examined by two board-certified forensic pathologists directly on the mannequin. These results were compared to an examination using standard 2D forensic photography; 2D photography using the multicamera system Botscan©, which included predefined viewing positions all around the body; and 3D photogrammetric reconstruction based on images visualized both on screen and in a virtual reality (VR) using a head-mounted display (HMD).The results of the gold standard examination showed that the two forensic pathologists had an inter-reader agreement ranging from 69% for the orientation and 11% for the size of the wounds. A substantial portion of the direct visual documentation showed only a partial overlap, especially for the items of size and color, thereby prohibiting the statistical comparison of these two items. A forest plot analysis of the remaining six items showed no significant difference between the methods. We found that among the forensic pathologists, there was high variability regarding the vocabulary used for the description of wound morphology, which complicated the exact comparison of the two documentations of the same wound.There were no significant differences for any of the four methods compared to the gold standard, thereby challenging the role of real-life examination and 2D photography as the most reliable documentation approaches. Further studies with real injuries are necessary to support our evaluation that technical examination methods involving multicamera systems and 3D visualization for whole-body examination might be a valid alternative in future forensic documentation.

scholarly journals Correlation of age, sex and season with the state of human decomposition as quantified by postmortem computed tomography

2021 ◽  
Author(s):  
Dominic L. C. Guebelin ◽  
Akos Dobay ◽  
Lars Ebert ◽  
Eva Betschart ◽  
Michael J. Thali ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Demographic Data ◽  
Sociodemographic Factors ◽  
The State ◽  
The Body ◽  
Seasonal Effects ◽  
Whole Body ◽  
Postmortem Computed Tomography ◽  
Whole Body Computed Tomography ◽  
Urban Study

AbstractDead bodies exhibit a variable range of changes with advancing decomposition. To quantify intracorporeal gas, the radiological alteration index (RAI) has been implemented in the assessment of postmortem whole-body computed tomography. We used this RAI as a proxy for the state of decomposition. This study aimed to (I) investigate the correlation between the state of decomposition and the season in which the body was discovered; and (II) evaluate the correlations between sociodemographic factors (age, sex) and the state of decomposition, by using the RAI as a proxy for the extent of decomposition. In a retrospective study, we analyzed demographic data from all autopsy reports from the Institute of Forensic Medicine of Zurich between January 2017 to July 2019 and evaluated the radiological alteration index from postmortem whole-body computed tomography for each case. The bodies of older males showed the highest RAI. Seasonal effects had no significant influence on the RAI in our urban study population with bodies mostly being discovered indoors. Autopsy reports contain valuable data that allow interpretation for reasons beyond forensic purposes, such as sociopolitical observations.

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