scholarly journals Emission from Human Skin in the Sub THz Frequency Band

2021 ◽  
Author(s):  
Noa Betzalel ◽  
Paul Ben Ishai ◽  
Alexander Puzenko ◽  
Yuri Feldman
Keyword(s):  
Human Skin ◽  
Human Subjects ◽  
Complex Structure ◽  
Skin Surface ◽  
Blackbody Radiation ◽  
The Body ◽  
Electromagnetic Simulation ◽  
Sweat Duct ◽  
Frequency Range ◽  
Body Core

Abstract Recently published Radiometric measurements of human subjects in the frequency range 480-700 GHz, demonstrate the emission of blackbody radiation from the body core, rather than the skin surface. We present a detailed electromagnetic simulation of the dermis and epidermis, taking into account the presence of the sweat duct. This complex structure can be considered as an electromagnetic bio-metamaterial, whereby the layered structure, along with the topology of the sweat duct, reveals a complex interference pattern in the skin. The model is capable of accurately representing the skin greyness factor as a function of frequency and this is confirmed by radiometry of living human skin.

Selective regulation of brain and body temperatures in the squirrel monkey

1983 ◽  
Vol 245 (2) ◽  
pp. R293-R297 ◽  
Author(s):  
C. A. Fuller ◽  
M. A. Baker
Keyword(s):  
Squirrel Monkey ◽  
Brain Temperature ◽  
Human Subjects ◽  
Venous Blood ◽  
The Body ◽  
Body Core Temperature ◽  
Saimiri Sciureus ◽  
Brain Cooling ◽  
The Face ◽  
Body Core

Many panting mammals can cool the brain below body core temperature during heat stress. Studies on human subjects suggest that primates may also be able selectively to regulate brain temperature. We examined this possibility by measuring hypothalamic (Thy) and colonic (Tco) temperatures of unanesthetized squirrel monkeys (Saimiri sciureus) in two different experiments. First, Thy and Tco were examined at four different ambient temperatures (Ta) between 20 and 36 degrees C. Over this range of Ta, Thy was regulated within a narrower range than Tco. In the cold Ta, Tco was lower than Thy; whereas in warm Ta, Tco was higher than Thy. Second, monkeys maintained at 35 degrees C Ta were acutely exposed to cool air blown on the face or abdomen. Air directed at the face cooled Thy more and faster than Tco, whereas air directed at the abdomen cooled Tco and Thy at the same rate. The second experiment was repeated in anesthetized animals with a thermocouple in the right atrium, and the results showed that this brain cooling was not produced by cooling of blood in the body core. These data demonstrate that the squirrel monkey is capable of selectively regulating Thy. Further the results suggest that venous blood returning from the face may be involved in selective brain cooling in warm environments.

scholarly journals Population level rhythms in human skin: implications for circadian medicine

2018 ◽  
Author(s):  
Gang Wu ◽  
Marc D. Ruben ◽  
Robert E. Schmidt ◽  
Lauren J. Francey ◽  
David F. Smith ◽  
...  
Keyword(s):  
Human Skin ◽  
Clock Genes ◽  
Human Subjects ◽  
Population Level ◽  
The Body ◽  
Single Sample ◽  
Circadian Phase ◽  
Important Barrier ◽  
Population Scale

AbstractSkin is the largest organ in the body and serves important barrier, regulatory, and sensory functions. Like other tissues, skin is subject to temporal fluctuations in physiological responses under both homeostatic and stressed states. To gain insight into these fluctuations, we investigated the role of the circadian clock in the transcriptional regulation of epidermis using a hybrid experimental design, where a limited set of human subjects (n=20) were sampled throughout the 24 h cycle and a larger population (n=219) were sampled once. By looking at pairwise correlations of core clock genes in 298 skin samples, we found a robust circadian oscillator in skin at the population level. Encouraged by this, we used CYCLOPS to reconstruct the temporal order of all samples and identified hundreds of rhythmically-expressed genes at the population level in human skin. We compared these results with published time-series skin data from mouse and show strong concordance in circadian phase across species for both transcripts and pathways. Further, like blood, skin is readily accessible and a potential source of biomarkers. Using ZeitZeiger, we identified a biomarker set for human skin that is capable of reporting circadian phase to within 3 h from a single sample. In summary, we show rhythms in human skin that persist at the population scale and a path to develop robust single-sample circadian biomarkers.One Sentence SummaryHuman epidermis shows strong circadian rhythms at the population scale and provides a better source for developing robust, single-sample circadian phase biomarkers than human blood.

Thermal Imaging in Evaluation of the Physical Fitness Level

2017 ◽  
pp. 141-164 ◽  
Author(s):  
Teresa Kasprzyk ◽  
Agata Stanek ◽  
Karolina Sieroń-Stołtny ◽  
Armand Cholewka
Keyword(s):  
Thermal Imaging ◽  
Skin Surface ◽  
The Body ◽  
Body Core Temperature ◽  
Skin Surface Temperature ◽  
Fitness Level ◽  
Surface Temperature Distribution ◽  
Body Core ◽  
Cycle Training ◽  
Basic Level

The thermoregulation mechanisms during the physical effort can be easily study by using the thermovision. The thermoregulation mechanisms in human body keep the body core temperature on basic level 37 ± 2oC. However, the question is if there are any differences in skin surface temperature distribution between trainee sportsmen and amateur. Is there any possibility to show the sportsman level of practise using the thermal imaging? Would it be possible to evaluate the efficiency of athlete or evaluate the level of sports possibilities in average amateur who just wants to start cycle training. To find how the thermoregulation mechanisms work the different measurements were done i.e. during the cyclist endurance test for group of male cyclist (intermediate level of cycling skill) and during the Aerobic Circuit Training (ACT) for trainee and amateur group of women.

Thermal Imaging in Evaluation of the Physical Fitness Level

2021 ◽  
pp. 772-794
Author(s):  
Teresa Kasprzyk ◽  
Agata Stanek ◽  
Karolina Sieroń-Stołtny ◽  
Armand Cholewka
Keyword(s):  
Thermal Imaging ◽  
Skin Surface ◽  
The Body ◽  
Body Core Temperature ◽  
Skin Surface Temperature ◽  
Fitness Level ◽  
Surface Temperature Distribution ◽  
Body Core ◽  
Cycle Training ◽  
Basic Level

The thermoregulation mechanisms during the physical effort can be easily study by using the thermovision. The thermoregulation mechanisms in human body keep the body core temperature on basic level 37 ± 2 oC. However, the question is if there are any differences in skin surface temperature distribution between trainee sportsmen and amateur. Is there any possibility to show the sportsman level of practise using the thermal imaging? Would it be possible to evaluate the efficiency of athlete or evaluate the level of sports possibilities in average amateur who just wants to start cycle training. To find how the thermoregulation mechanisms work the different measurements were done i.e. during the cyclist endurance test for group of male cyclist (intermediate level of cycling skill) and during the Aerobic Circuit Training (ACT) for trainee and amateur group of women.

Comparison of the thermoregulatory response of buffaloes and tropical cattle, using fluctuations in rectal temperature, skin temperature and haematocrit as an index

2004 ◽  
Vol 142 (3) ◽  
pp. 351-355 ◽  
Author(s):  
A. KOGA ◽  
M. SUGIYAMA ◽  
A. N. DEL BARRIO ◽  
R. M. LAPITAN ◽  
B. R. ARENDA ◽  
...  
Keyword(s):  
Blood Flow ◽  
Ambient Temperature ◽  
Skin Temperature ◽  
Correlation Coefficient ◽  
Rectal Temperature ◽  
Comparative Studies ◽  
Skin Surface ◽  
The Body ◽  
Thermoregulatory Response ◽  
Body Core

In previous comparative studies of buffaloes and temperate cattle, a greater increase in rectal temperature (RT) and skin temperature (ST), and a greater decrease in haematocrit (Ht) have been observed in buffaloes than in temperate cattle with an increase in ambient temperature (AT). Our series of previous experiments suggested that great changes in RT, ST and Ht are induced in buffaloes by a marked increase in blood flow from the body core to the surface, which accelerates dissipation of heat from the skin surface. On the basis of these suggestions, the present study was undertaken to compare fluctuations in RT, ST and Ht between buffaloes and tropical cattle. Fluctuations in the aforementioned parameters, particularly RT and Ht, were greater in buffaloes than in cattle. Moreover, the correlation for RT or Ht v. AT was significant for buffaloes (r=0·33 and −0·37, respectively) but not for cattle. The correlation coefficient for ST v. AT was significant in both species, but was greater in buffaloes (r=0·63) than in cattle (r=0·56). These results demonstrate that with changes in ambient temperature, RT, ST and Ht fluctuate much more in buffaloes than in tropical cattle, as found previously for temperate cattle. Therefore, the distinctive thermoregulatory responses of buffalo are confirmed as being specific to this species.

A Graphical Approach for Human Skin Moisture Evaluation by Electrical Impedance Spectroscopy

2013 ◽  
Vol 336-338 ◽  
pp. 319-326 ◽  
Author(s):  
Yu Xing He ◽  
Yong Gui Dong
Keyword(s):  
Impedance Spectroscopy ◽  
Stratum Corneum ◽  
Human Skin ◽  
Electrical Impedance ◽  
Skin Surface ◽  
Electrical Impedance Spectroscopy ◽  
Frequency Range ◽  
Arc Model ◽  
Quantitative Calculation ◽  
Skin Moisture

A pair of concentrically placed gold electrodes is utilized in contact with human skin surface for moisture evaluation. The electrical impedance spectroscopy is measured within a frequency range of 100Hz to 5MHz. It is showed that, in case of relatively dried stratum corneum, reproducibility of measured impedances will decrease significantly in lower frequency range. The integrality of impedance frequency locus is correspondingly dependent on skin moist state. On the other hand, in case of relatively wetted stratum corneum, an integral locus can be obtained and Cole-Cole arc model can be applied for quantitative calculation. The integrality of the locus is introduced as a supplemental parameter. Experimental results with moistened filter paper as well as human skin indicate that, the skin moisture can be better represented both graphically and quantitatively.

Research Recommendations for Applying Vitamin A-Labelled Isotope Dilution Techniques to Improve Human Vitamin A Nutrition

2014 ◽  
Vol 84 (Supplement 1) ◽  
pp. 52-59 ◽  
Author(s):  
Sherry A. Tanumihardjo ◽  
Anura V. Kurpad ◽  
Janet R. Hunt
Keyword(s):  
Public Health ◽  
Vitamin A ◽  
Vitamin A Deficiency ◽  
Human Subjects ◽  
The Body ◽  
Pool Size ◽  
Serum Retinol ◽  
Vitamin A Status ◽  
Status Assessment ◽  
Total Body

The current use of serum retinol concentrations as a measurement of subclinical vitamin A deficiency is unsatisfactory for many reasons. The best technique available for vitamin A status assessment in humans is the measurement of total body pool size. Pool size is measured by the administration of retinol labelled with stable isotopes of carbon or hydrogen that are safe for human subjects, with subsequent measurement of the dilution of the labelled retinol within the body pool. However, the isotope techniques are time-consuming, technically challenging, and relatively expensive. There is also a need to assess different types of tracers and doses, and to establish clear guidelines for the use and interpretation of this method in different populations. Field-friendly improvements are desirable to encourage the application of this technique in developing countries where the need is greatest for monitoring the risk of vitamin A deficiency, the effectiveness of public health interventions, and the potential of hypervitaminosis due to combined supplement and fortification programs. These techniques should be applied to validate other less technical methods of assessing vitamin A deficiency. Another area of public health relevance for this technique is to understand the bioconversion of β-carotene to vitamin A, and its relation to existing vitamin A status, for future dietary diversification programs.

Enzymatic Determination of Hydroxysteroids in Human Skin Surface Lipids1

1963 ◽  
Vol 41 (5) ◽  
pp. 265-268 ◽  
Author(s):  
Thomas J Cook ◽  
Allan L Lorincz ◽  
Alan R Spector
Keyword(s):  
Human Skin ◽  
Skin Surface ◽  
Enzymatic Determination

Locomotory Diseases Influence on Body Equilibrium and Balance

2014 ◽  
Vol 555 ◽  
pp. 652-658 ◽  
Author(s):  
Barbu Cristian Braun ◽  
Ileana Constanta Rosca
Keyword(s):  
Body Mass ◽  
Human Subjects ◽  
Force Plate ◽  
The Body ◽  
The Other ◽  
New Method ◽  
First Person ◽  
Mass Center ◽  
Stability Problems ◽  
Research Stage

The paper describes a new method of body equilibrium evaluation applied for different human subjects, the principal aim being to demonstrate to what extent any locomotory diseases could influence the body stability and equilibrium. The research refers to identify some persons with different locomotory diseases and to find both the influence on equilibrium and stability and if possible to improve them. Our research stage, synthesized in this paper, explains the body equilibrium evaluation in orthostatic posture done for different subjects, aged between 20 and 40 years. A number of 10 relevant persons were considered to be evaluated, 2 of them having some locomotory diseases. The first person presents any neuro-motor stability problems in case of long standing case. The other person has both Achilles tendons torn and operated. All subjects were tested in orthostatic posture, in 3 distinct positions, using a Kistler force plate. The experiments referred to the body mass center (COM) displacement in sagittal and lateral planes, representing an interesting characteristic for its equilibrium. It was shown that the person with diseases affecting stability presented a loss of equilibrium when standing for 10-20 seconds, i.e. higher COM displacements in both planes reported to the other tested subjects.

Respiratory measurements of cardiac output: from elegant idea to useful test

2004 ◽  
Vol 96 (2) ◽  
pp. 428-437 ◽  
Author(s):  
Gabriel Laszlo
Keyword(s):  
Cardiac Output ◽  
Human Subjects ◽  
Venous Blood ◽  
The Body ◽  
Mixed Venous Blood ◽  
Indirect Determination ◽  
Arterial Blood ◽  
Pulmonary Capillary ◽  
Pulmonary Arterial ◽  
Mixed Venous

The measurement of cardiac output was first proposed by Fick, who published his equation in 1870. Fick's calculation called for the measurement of the contents of oxygen or CO2 in pulmonary arterial and systemic arterial blood. These values could not be determined directly in human subjects until the acceptance of cardiac catheterization as a clinical procedure in 1940. In the meanwhile, several attempts were made to perfect respiratory methods for the indirect determination of blood-gas contents by respiratory techniques that yielded estimates of the mixed venous and pulmonary capillary gas pressures. The immediate uptake of nonresident gases can be used in a similar way to calculate cardiac output, with the added advantage that they are absent from the mixed venous blood. The fact that these procedures are safe and relatively nonintrusive makes them attractive to physiologists, pharmacologists, and sports scientists as well as to clinicians concerned with the physiopathology of the heart and lung. This paper outlines the development of these techniques, with a discussion of some of the ways in which they stimulated research into the transport of gases in the body through the alveolar membrane.

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