scholarly journals Tactile sensing biohybrid soft E-skin based on bioimpedance using aloe vera pulp tissues

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mostafa A. Mousa ◽  
MennaAllah Soliman ◽  
Mahmood A. Saleh ◽  
Ahmed G. Radwan
Keyword(s):  
Human Skin ◽  
Aloe Vera ◽  
Skin Surface ◽  
Biological Tissues ◽  
Tactile Sensing ◽  
Soft Robots ◽  
Sensing System ◽  
Human Sensing ◽  
Morphological Computation ◽  
The Brain

AbstractSoft and flexible E-skin advances are a subset of soft robotics field where the soft morphology of human skin is mimicked. The number of prototypes that conformed the use of biological tissues within the structure of soft robots—to develop “Biohybrid Soft Robots”—has increased in the last decade. However, no research was conducted to realize Biohybrid E-skin. In this paper, a novel biohybrid E-skin that provides tactile sensing is developed. The biohybrid E-skin highly mimics the human skin softness and morphology and can sense forces as low as 0.01 newton . The tactile sensing feature is augmented through the use of Aloe Vera pulp, embedded in underlying channel, where the change in its bioimpedance is related to the amount of force exerted on the E-skin surface. The biohybrid E-skin employs high biomimicry as the sensorial output is an oscillating signal similar to signals sent from the human sensing neurons to the brain. After investigating different channel geometries, types of filling tissues, and usage of two silicone materials, their frequency-force behaviour is modelled mathematically. Finally, a functional multichannel prototype “ImpEdded Skin” is developed. This prototype could efficiently detect the position of a tactile touch. This work employs the development of discrete sensing system that exhibits morphological computation that consequently enhances performance.

A Portable Human Skin Tester Based on Resistance and Capacitance Measurement

2014 ◽  
Vol 1035 ◽  
pp. 401-407
Author(s):  
Bin Yang ◽  
Yong Gui Dong
Keyword(s):  
Human Skin ◽  
Skin Surface ◽  
Capacitance Measurement ◽  
Sensing Element ◽  
Sensing System ◽  
Interdigital Electrodes ◽  
In Series ◽  
Dependent Property ◽  
Good Repeatability ◽  
Measured Response

A portable tester for accessing the electrical properties of human skin surface is reported. A pair of interdigital electrodes (IDE) that contact directly with the human skin, is used as the sensing element. The impedance of the sensing system is modeled as a resistance and a capacitance in series. A square wave signal is applied so that impedance of the IDE is measured in a charging/discharging way. The response voltages of the IDE at two excitation frequencies, 10 kHz and 600 Hz, are measured successively during one measurement cycle. Since the equivalent capacitance of skin performs different frequency-dependent property other than the resistance, their values can be resolved from the measured response voltages. A microprocessor-based system is implemented as a prototype battery-powered portable unit for household measurements. Good repeatability and satisfied accuracy have been obtained by experimental results.

scholarly journals Optical properties of the human skin / Optičke osobine ljudske kože

2010 ◽  
Vol 2 (4) ◽  
pp. 131-136 ◽  
Author(s):  
Zorica Gajinov ◽  
Milan Matić ◽  
Sonja Prćić ◽  
Verica Đuran
Keyword(s):  
Human Skin ◽  
Rayleigh Scattering ◽  
Brain Cortex ◽  
Volume Fraction ◽  
Skin Surface ◽  
Mie Scattering ◽  
Subsurface Scattering ◽  
Incident Wavelength ◽  
Scattering Light ◽  
The Brain

Abstract Visual perception of human skin is determined by the light that reflects off the skin surface to retina and interpretation of these information by visual centers in the brain cortex. Skin has a partly translucent and turbid structure and visual perceptions depend on interactions between the light and structures of the skin surface and below it, through absorption, reflection and scattering. Light absorption by the skin depends on the composition, absorption spectra and amount (volume fraction) of chromophores. Subsurface scattering occurs within the skin layers: Rayleigh scattering (subcellular structures sized up to 1/10 of incident wavelength) and Mie scattering (collagen, melanosomes). Due to fluctuations of the refractive index within tissue components and intense scattering, the spatial distribution of light within the skin is diffuse. Skin images are created by the light that reflects off the skin after being color-modified by absorption and being scattered on the skin surface and internal skin structures.

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

Simultaneous Determination of Imatinib and N-Desmethyl Imatinib in Rat Plasma and Tissues Using LC-MS/MS

2019 ◽  
Vol 15 (2) ◽  
pp. 121-129
Author(s):  
Zhi Rao ◽  
Bo-xia Li ◽  
Yong-Wen Jin ◽  
Wen-Kou ◽  
Yan-rong Ma ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Oral Administration ◽  
Parent Drug ◽  
Gradient Elution ◽  
Biological Tissues ◽  
Rat Plasma ◽  
Running Water ◽  
Liver And Kidney ◽  
The Brain

Background: Imatinib (IM) is a chemotherapy medication metabolized by CYP3A4 to Ndesmethyl imatinib (NDI), which shows similar pharmacologic activity to the parent drug. Although methods for determination of IM and/or NDI have been developed extensively, only few observations have been addressed to simultaneously determine IM and NDI in biological tissues such as liver, kidney, heart, brain and bone marrow. Methods: A validated LC-MS/MS method was developed for the quantitative determination of imatinib (IM) and N-desmethyl imatinib (NDI) from rat plasma, bone marrow, brain, heart, liver and kidney. The plasma samples were prepared by protein precipitation, and then the separation of the analytes was achieved using an Agilent Zorbax Eclipse Plus C18 column (4.6 × 100 mm, 3.5 µm) with gradient elution running water (A) and methanol (B). Mass spectrometric detection was achieved by a triplequadrupole mass spectrometer equipped with an electrospray source interface in positive ionization mode. Results: This method was used to investigate the pharmacokinetics and the tissue distributions in rats following oral administration of 25 mg/kg of IM. The pharmacokinetic profiles suggested that IM and NDI are disappeared faster in rats than human, and the tissue distribution results showed that IM and NDI had good tissue penetration and distribution, except for the brain. This is the first report about the large penetrations of IM and NDI in rat bone marrow. Conclusion: The method demonstrated good sensitivity, accuracy, precision and recovery in assays of IM and NDI in rats. The described assay was successfully applied for the evaluation of pharmacokinetics and distribution in the brain, heart, liver, kidney and bone marrow of IM and NDI after a single oral administration of IM to rats.

scholarly journals Effect of an extract of Aloe vera on the biodistribution of sodium pertechnetate (Na99mTcO4) in rats

2009 ◽  
Vol 24 (5) ◽  
pp. 383-386 ◽  
Author(s):  
Cecília Maria de Carvalho Xavier Holanda ◽  
Monique Batista da Costa ◽  
Natália Chilinque Zambão da Silva ◽  
Maurício Ferreira da Silva Júnior ◽  
Vanessa Santos de Arruda Barbosa ◽  
...  
Keyword(s):  
Aqueous Extract ◽  
Aloe Vera ◽  
Treated Group ◽  
Control Group ◽  
Blood Levels ◽  
Control Groups ◽  
High Increase ◽  
Tropical Plant ◽  
And Control ◽  
The Brain

PURPOSE: Aloe vera is a tropical plant popularly known in Brazil as babosa. We have investigated the effect of aqueous extract of Aloe vera on the biodistribution of Na99mTcO4 and laboratorial parameters in Wistar rats. METHODS: Twelve animals were divided into treated and control groups. In the treated group, Aloe vera was given by gavage (5mg/mL/day) during 10 days. The control group received sorbitol by the same way and period. One hour after the last dose, we injected 0.1mL of Na99mTcO4 by orbital plexus. After 60 min, all the animals were killed. Samples were harvested from the brain, liver, heart, muscle, pancreas, stomach, femur, kidneys, blood, testis and thyroid and the percentage of radioactivity (%ATI/g) was determined. Biochemical dosages were performed. RESULTS: There was a significant increase of %ATI/g in blood, femur, kidneys, liver, stomach, testis and thyroid and also in blood levels of AST and ALT. A significant decrease in levels of glucose, cholesterol, triglycerides, creatinine and urea occurred. The statistical analyses were performed by Mann-Whitney test and T-Student test (p<0.05). CONCLUSION: The aqueous extract of Aloe vera facilitated the uptake of Na99mTcO4 in organs of rats and it was responsible to a high increase of levels of AST and ALT.

scholarly journals Host/Malassezia Interaction: A Quantitative, Non-Invasive Method Profiling Oxylipin Production Associates Human Skin Eicosanoids with Malassezia

Metabolites ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 700
Author(s):  
Yohannes Abere Ambaw ◽  
Martin P. Pagac ◽  
Antony S. Irudayaswamy ◽  
Manfred Raida ◽  
Anne K. Bendt ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Immune System ◽  
Polyunsaturated Fatty Acids ◽  
Human Skin ◽  
Skin Surface ◽  
Lipid Mediators ◽  
Dependent Manner ◽  
Human Immune System ◽  
Plant Host

Malassezia are common components of human skin, and as the dominant human skin eukaryotic microbe, they take part in complex microbe–host interactions. Other phylogenetically related fungi (including within Ustilagomycotina) communicate with their plant host through bioactive oxygenated polyunsaturated fatty acids, generally known as oxylipins, by regulating the plant immune system to increase their virulence. Oxylipins are similar in structure and function to human eicosanoids, which modulate the human immune system. This study reports the development of a highly sensitive mass-spectrometry-based method to capture and quantify bioactive oxygenated polyunsaturated fatty acids from the human skin surface and in vitro Malassezia cultures. It confirms that Malassezia are capable of synthesizing eicosanoid-like lipid mediators in vitro in a species dependent manner, many of which are found on human skin. This method enables sensitive identification and quantification of bioactive lipid mediators from human skin that may be derived from metabolic pathways shared between skin and its microbial residents. This enables better cross-disciplinary and detailed studies to dissect the interaction between Malassezia and human skin, and to identify potential intervention points to promote or abrogate inflammation and to improve human skin health.

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