scholarly journals Examination of rabbit liver by ultrasound

2021 ◽  
Vol 37 ◽  
pp. 00179
Author(s):  
Victor Trotsenko ◽  
Irina Trotsenko ◽  
Olga Bdyukhina ◽  
Zhanbota Esmurzaeva
Keyword(s):  
Mechanical Properties ◽  
Linear Relationship ◽  
Water Content ◽  
Liver Cells ◽  
Cellular Material ◽  
Rabbit Liver ◽  
Sonic Velocity ◽  
Velocity Of Ultrasound

The article provides information on the study of the mechanical properties of isolated rabbit liver cells in terms of density, compressibility and ultra-sonic velocity. It was found that the values of the studied characteristics are mainly determined by the water content in the cells. The density, compressibility, and velocity of ultrasound in the cellular material are interconnected by a linear relationship.

Hydrogels as Antibacterial Biomaterials

2018 ◽  
Vol 24 (8) ◽  
pp. 843-854 ◽  
Author(s):  
Weiguo Xu ◽  
Shujun Dong ◽  
Yuping Han ◽  
Shuqiang Li ◽  
Yang Liu
Keyword(s):  
Mechanical Properties ◽  
Drug Delivery ◽  
Tissue Engineering ◽  
Water Content ◽  
Oxygen Permeability ◽  
Structural Diversity ◽  
High Water ◽  
Clinical Applications ◽  
High Water Content ◽  
Biomedical Field

Hydrogels, as a class of materials for tissue engineering and drug delivery, have high water content and solid-like mechanical properties. Currently, hydrogels with an antibacterial function are a research hotspot in biomedical field. Many advanced antibacterial hydrogels have been developed, each possessing unique qualities, namely high water swellability, high oxygen permeability, improved biocompatibility, ease of loading and releasing drugs and structural diversity. In this article, an overview is provided on the preparation and applications of various antibacterial hydrogels. Furthermore, the prospects in biomedical researches and clinical applications are predicted.

Mechanical Properties with Respect to Water Content of Host–Guest Hydrogels

2021 ◽  
Vol 54 (17) ◽  
pp. 8067-8076 ◽  
Author(s):  
Motofumi Osaki ◽  
Shin Yonei ◽  
Chiharu Ueda ◽  
Ryohei Ikura ◽  
Junsu Park ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Water Content

Study on mechanical properties and damage evolution of carbonaceous shale under triaxial compression with acoustic emission

2021 ◽  
pp. 105678952199119
Author(s):  
Kai Yang ◽  
Qixiang Yan ◽  
Chuan Zhang ◽  
Wang Wu ◽  
Fei Wan
Keyword(s):  
Mechanical Properties ◽  
Acoustic Emission ◽  
Water Content ◽  
Damage Evolution ◽  
Damage Assessment ◽  
Triaxial Compression ◽  
Confining Pressure ◽  
Damage Variable ◽  
Natural State ◽  
Carbonaceous Shale

To explore the mechanical properties and damage evolution characteristics of carbonaceous shale with different confining pressures and water-bearing conditions, triaxial compression tests accompanied by simultaneous acoustic emission (AE) monitoring were conducted on carbonaceous shale rock specimens. The AE characteristics of carbonaceous shale were investigated, a damage assessment method based on Shannon entropy of AE was further proposed. The results suggest that the mechanical properties of carbonaceous shale intensify with increasing confining pressure and degrade with increasing water content. Moisture in rocks does not only weaken the cohesion but also reduce the internal friction angle of carbonaceous shale. It is observed that AE activities mainly occur in the post-peak stage and the strong AE activities of saturated carbonaceous shale specimens appear at a lower normalized stress level than that of natural-state specimens. The maximum AE counts and AE energy increase with water content while decrease with confining pressure. Both confining pressure and water content induce changes in the proportions of AE dominant frequency bands, but the changes caused by confining pressure are more significant than those caused by water content. The results also indicate that AE entropy can serve as an applicable index for rock damage assessment. The damage evolution process of carbonaceous shale can be divided into two main stages, including the stable damage development stage and the damage acceleration stage. The damage variable increases slowly accompanied by a few AE activities at the first stage, which is followed by a rapid growth along with intense acoustic emission activities at the damage acceleration stage. Moreover, there is a sharp rise in the damage evolution curve for the natural-state specimen at the damage acceleration stage, while the damage variable develops slowly for the saturated-state specimen.

scholarly journals Acetyl hexapeptide-3 in a cosmetic formulation acts on skin mechanical properties - clinical study

2015 ◽  
Vol 51 (4) ◽  
pp. 901-909 ◽  
Author(s):  
Kassandra Azevedo Tadini ◽  
Daiane Garcia Mercurio ◽  
Patrícia Maria Berardo Gonçalves Maia Campos
Keyword(s):  
Mechanical Properties ◽  
Stratum Corneum ◽  
Water Content ◽  
Topical Formulations ◽  
Face Area ◽  
Cutaneous Tissue ◽  
The Face ◽  
Skin Conditions ◽  
Basic Studies ◽  
Stratum Corneum Water Content

abstract Acetyl hexapeptide-3 has been used in anti-aging topical formulations aimed at improving skin appearance. However, few basic studies address its effects on epidermis and dermis, when vehiculated in topical formulations. Thus, the objective of this study was to determine the clinical efficacy of acetyl hexapeptide-3 using biophysical techniques. For this purpose, formulations with and without acetyl hexapeptide-3 were applied to the ventral forearm and the face area of forty female volunteers. Skin conditions were evaluated after 2 and 4-week long daily applications, by analyzing the stratum corneum water content and the skin mechanical properties, using three instruments, the Corneometer(r) CM 825, CutometerSEM 575 and ReviscometerRV600. All formulations tested increased the stratum corneum water content in the face region, which remained constant until the end of the study. In contrast, only formulations containing acetyl hexapeptide-3 exhibit a significant effect on mechanical properties, by decreasing the anisotropy of the face skin. No significant effects were observed in viscoelasticity parameters. In conclusion, the effects of acetyl hexapeptide-3 on the anisotropy of face skin characterize the compound as an effective ingredient for improving conditions of the cutaneous tissue, when used in anti-aging cosmetic formulations.

scholarly journals Influence of Water Content on the β-Sheet Formation, Thermal Stability, Water Removal, and Mechanical Properties of Silk Materials

2016 ◽  
Vol 17 (3) ◽  
pp. 1057-1066 ◽  
Author(s):  
Kenjiro Yazawa ◽  
Kana Ishida ◽  
Hiroyasu Masunaga ◽  
Takaaki Hikima ◽  
Keiji Numata
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Water Content ◽  
Water Removal ◽  
Influence Of Water ◽  
Β Sheet

Inferring the effects of surface canopy water on VOD estimation from L-band backscatter 

2021 ◽  
Author(s):  
Saeed Khabbazan ◽  
Paul.C. Vermunt ◽  
Susan.C. Steele Dunne ◽  
Ge Gao ◽  
Mariette Vreugdenhil ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Linear Relationship ◽  
Water Content ◽  
Growing Season ◽  
Empirical Parameter ◽  
Vegetation Water Content ◽  
L Band ◽  
Vegetation Water ◽  
Canopy Water ◽  
Effect Of Surface

<p>Quantification of vegetation parameters such as Vegetation Optical Depth (VOD) and Vegetation Water Content (VWC) can be used for better irrigation management, yield forecasting, and soil moisture estimation. Since VOD is directly related to vegetation water content and canopy structure, it can be used as an indicator for VWC. Over the past few decades, optical and passive microwave satellite data have mostly been used to monitor VWC. However, recent research is using active data to monitor VOD and VWC benefitting from their high spatial and temporal resolution.</p><p>Attenuation of the microwave signal through the vegetation layer is parametrized by the VOD. VOD is assumed to be linearly related to VWC with the proportionality constant being an empirical parameter b. For a given wavelength and polarization, b is assumed static and only parametrized as a function of vegetation type. The hypothesis of this study is that the VOD is not similar for dry and wet vegetation and the static linear relationship between attenuation and vegetation water content is a simplification of reality.</p><p>The aim of this research is to understand the effect of surface canopy water on VOD estimation and the relationship between VOD and vegetation water content during the growing season of a corn canopy. In addition to studying the dependence of VOD on bulk VWC for dry and wet vegetation, the effect of different factors, such as different growth stages and internal vegetation water content is investigated using time series analysis.</p><p>A field experiment was conducted in Florida, USA, for a full growing season of sweet corn. The corn field was scanned every 30 minutes with a truck-mounted, fully polarimetric, L-band radar. Pre-dawn vegetation water content was measured using destructive sampling three times a week for a full growing season. VWC could therefore be analyzed by constituent (leaf, stem, ear) or by height. Meteorological data, surface canopy water (dew or interception), and soil moisture were measured every 15 minutes for the entire growing season.</p><p>The methodology of Vreugdenhil et al.  [1], developed by TU Wien for ASCAT data, was adapted to present a new technique to estimate VOD from single-incidence angle backscatter data in each polarization. The results showed that the effect of surface canopy water on the VOD estimation increased by vegetation biomass accumulation and the effect was higher in the VOD estimated from the co-pol compared with the VOD estimated from the cross-pol. Moreover, the surface canopy water considerably affected the regression coefficient values (b-factor) of the linear relationship between VOD and VWC from dry and wet vegetation. This finding suggests that considering a similar b-factor for the dry and the wet vegetation will introduce errors in soil moisture retrievals. Furthermore, it highlights the importance of considering canopy wetness conditions when using tau-omega.</p><ul><li>[1] Vreugdenhil,W. A. Dorigo,W.Wagner, R. A. De Jeu, S. Hahn, andM. J. VanMarle, “Analyzing the vegetation parameterization in the TU-Wien ASCAT soil moisture retrieval,” IEEE Transactions on Geoscience and Remote Sensing, vol. 54, pp. 3513–3531, 2016</li> </ul>

Nervous Control of the Mechanical Properties of the Abdominal Wall at Feeding in Rhodnius

1966 ◽  
Vol 44 (1) ◽  
pp. 59-68
Author(s):  
S. H. P. MADDRELL
Keyword(s):  
Mechanical Properties ◽  
Water Content ◽  
Abdominal Wall ◽  
Cumulative Effect ◽  
Nervous Control

1. When larvae of Rhodnius feed, the abdominal wall rapidly becomes extensible. This change is brought about peripherally by the abdominal nervous supply; as a consequence, abdominal segments which have been denervated fail to stretch as much at feeding as do neighbouring innervated segments. 2. The stimulus for this change originates in the head. It appears that the sensations accompanying feeding are responsible and that they have a cumulative effect, so that the degree of plasticization of the abdominal wall depends on the length of time during which the insect has been sucking. 3. Neurosecretory axons are the only known efferent supply to the abdominal wall and so it is most probable that they cause the localized plasticization. 4. The evidence suggests that the plasticization of the abdominal cuticle is a result of an increase in its water content. 5. The increase in plasticity of the abdominal wall is temporary, the effect decreasing progressively after feeding.

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