scholarly journals Experimental studies of optoacoustic effect on the model of erythrocytes in the presence of carbon nanoparticles

2019 ◽  
Vol 8 (3) ◽  
pp. 11-18
Author(s):  
D. A. Kravchuk ◽  
D. V. Orda-Zhigulina
Keyword(s):  
Blood Cells ◽  
Carbon Nanoparticles ◽  
Coefficient Of Thermal Expansion ◽  
Experimental Studies ◽  
Polystyrene Microspheres ◽  
Optoacoustic Effect ◽  
Thermophysical Parameters ◽  
Absorption Of Light ◽  
Isobaric Specific Heat ◽  
Intracellular Volume

Experimental model has been developed to study optoacoustic signal from model blood cells presented by polystyrene microspheres with nanoparticles. It was found out that nanoparticles due to their strong absorption of light significantly affect the coefficient of cellular optical absorption, while the thermophysical parameters, namely the coefficient of thermal expansion, compressibility and isobaric specific heat of cells remain unchanged, since nanoparticles occupy a small intracellular volume compared to the cell volume. Optoacoustic signals were obtained using model solutions at various concentrations of cells and nanoparticles using 1064 nm laser. The results of experimental measurements using LIMO 100–532/1064-U system based on Nd:YAG showed that the amplitude of the optoacoustic signal increased without increasing the temperature in the laser area.

scholarly journals Emerging cellular and molecular mechanisms underlying anticancer indications of chrysin

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Marjan Talebi ◽  
Mohsen Talebi ◽  
Tahereh Farkhondeh ◽  
Jesus Simal-Gandara ◽  
Dalia M. Kopustinskiene ◽  
...  
Keyword(s):  
Blood Cells ◽  
Molecular Mechanisms ◽  
Web Of Science ◽  
Experimental Studies ◽  
Protective Effects ◽  
Pharmacological Activities ◽  
Current Review ◽  
Mesh Terms ◽  
Online Databases ◽  
Anti Cancer

AbstractChrysin has been shown to exert several beneficial pharmacological activities. Chrysin has anti-cancer, anti-viral, anti-diabetic, neuroprotective, cardioprotective, hepatoprotective, and renoprotective as well as gastrointestinal, respiratory, reproductive, ocular, and skin protective effects through modulating signaling pathway involved in apoptosis, oxidative stress, and inflammation. In the current review, we discussed the emerging cellular and molecular mechanisms underlying therapeutic indications of chrysin in various cancers. Online databases comprising Scopus, PubMed, Embase, ProQuest, Science Direct, Web of Science, and the search engine Google Scholar were searched for available and eligible research articles. The search was conducted by using MeSH terms and keywords in title, abstract, and keywords. In conclusion, experimental studies indicated that chrysin could ameliorate cancers of the breast, gastrointestinal tract, liver and hepatocytes, bladder, male and female reproductive systems, choroid, respiratory tract, thyroid, skin, eye, brain, blood cells, leukemia, osteoblast, and lymph. However, more studies are needed to enhance the bioavailability of chrysin and evaluate this agent in clinical trial studies. Graphic abstract

Experimental studies in insect parasitism XIV. The haemocytic reaction of a caterpillar to larvae of its habitual parasite

1966 ◽  
Vol 165 (999) ◽  
pp. 155-178 ◽  
Keyword(s):  
Foreign Body ◽  
Embryonic Development ◽  
Chemical Treatment ◽  
Blood Cells ◽  
Protective Property ◽  
Foreign Bodies ◽  
Experimental Studies ◽  
Ephestia Kuehniella ◽  
Main Theme ◽  
Ionic Exchange

Although caterpillars of Ephestia kuehniella promptly encapsulate alien parasites and other foreign bodies in their haemocoele, they do not normally encapsulate larvae of their habitual parasite Nemeritis canescens , which develop unhindered and eventually destroy their host. The larva of Nemeritis does not achieve this immunity by repelling the blood cells, or by physically dislodging them. It is immune because it is able to live in the haemocoele of Ephestia without evoking a haemocytic reaction; presumably, that is, because it is not recognized as a foreign body. That ability is due to a property of its surface. So long as its surface remains unaltered, the larva, alive or dead, evokes no haemocytic reaction. When its surface is altered whether by perforation, abrasion, or chemical treatment, the living larva evokes a haemocytic reaction in Ephestia and becomes encapsulated. The protective property of its surface is acquired by the larva very late in its embryonic development, between 62 and 66 hours of age at 25 °C. This is about the same time as, or a little later than, the cuticle of the embryonic larva becomes impermeable to water. Four fat solvents were found to deprive the living larva of its immunity, but they may have affected the protective surface by disrupting the underlying wax layer of the epicuticle. Treatments and substances that did not affect the protective surface give some crude indications of its properties, but its ultimate characterization must be in terms of insect immunology. Observations incidental to the main theme of the paper show that the cuticle of the larva is impermeable to water; that ionic exchange takes place through the anus and wall of the rectum, where some food substances may also be absorbed from the blood of the host; and that the order of formation of the cuticulin and wax layers of the embryonic larva is the same as that in ecdysis from instar to instar in other insects. They also provide information on the longevity of bitten supernumerary larvae.

Decrease in platelet count as an independent risk factor for symptomatic vasospasm following aneurysmal subarachnoid hemorrhage

2005 ◽  
Vol 102 (5) ◽  
pp. 882-887 ◽  
Author(s):  
Yutaka Hirashima ◽  
Hideo Hamada ◽  
Masanori Kurimoto ◽  
Hideki Origasa ◽  
Shunro Endo
Keyword(s):  
Platelet Count ◽  
Subarachnoid Hemorrhage ◽  
Blood Cells ◽  
White Blood Cells ◽  
Experimental Studies ◽  
Content Type ◽  
Symptomatic Vasospasm ◽  
Cell Counts ◽  
Fisher Grade ◽  
Fine Print

Object. Increased platelet consumption is expected in patients with cerebral vasospasm, according to data from clinical and experimental studies. The authors investigated sequential changes in platelet counts in patients with subarachnoid hemorrhage (SAH) and the difference in platelet consumption between patients with and those without symptomatic vasospasm (SV). Variables related to platelet count as well as other clinical and radiological variables were analyzed as independent predictors of SV. Methods. One hundred consecutive patients who had undergone surgery within 48 hours after SAH onset were entered in the study. Clinical and radiological variables and blood cell counts, including red blood cells, white blood cells, and platelets, after SAH were retrospectively examined. Twenty of these variables were entered into univariate and multivariate analyses to determine predictors for SV. After SAH, the platelet count decreased to a minimum and then increased rapidly to levels greater than those recorded on admission. This change was specific to SAH, and platelet consumption was more severe in patients with SV than in those without. There were three independent predictors of SV: a ratio of the lowest platelet count and the admission count greater than 0.7 (odds ratio [OR] 0.322, 95% confidence interval [CI] 0.124–0.834, p = 0.0196) and a history of hypertension (OR 0.338, 95% CI 0.126–0.906, p = 0.0311) were negatively significant (that is, decreases the occurrence of SV), and a Fisher Grade 3 (OR 4.42, 95% CI 1.48–13.2, p = 0.0077) was positively significant (that is, increases the occurrence of SV). Conclusions. The association between a decrease in platelet count and the occurrence of SV indicates the important role of platelets in the pathophysiology of vasospasm following SAH.

scholarly journals Carbon Nanoparticles. Production, properties, perspectives of use

2020 ◽  
Vol 21 (1) ◽  
pp. 13-18
Author(s):  
P. P. Maksimyak ◽  
C. Yu. Zenkova ◽  
V. M. Tkachuk
Keyword(s):  
Optical Properties ◽  
Carbon Nanoparticles ◽  
Carbon Nanostructures ◽  
Experimental Studies ◽  
Optimal Conditions ◽  
Blue Region ◽  
The Creation

The paper is devoted to the study of the optical properties of carbon nanoparticles synthesized by the method developed during our experimental studies. The optimal conditions for the creation of carbon nanostructures with predetermined properties are defined. Nanoparticles of the size of about 100 nm were obtained, the maximum of absorption of which is localized at wavelengths in the violet-blue region of the spectrum, while the maximum of luminescence – in the green region of the spectrum. The assumption is made about the possibility of using the obtained particles for correlation diagnostics of optical speckle fields.

scholarly journals Dynamics of a large population of red blood cells under shear flow

2019 ◽  
Vol 864 ◽  
pp. 408-448 ◽  
Author(s):  
C. Minetti ◽  
V. Audemar ◽  
T. Podgorski ◽  
G. Coupier
Keyword(s):  
Flow Stress ◽  
Shear Flow ◽  
Red Blood Cells ◽  
Blood Cells ◽  
Rate Increase ◽  
Large Population ◽  
Experimental Studies ◽  
Hysteresis Loops ◽  
Fluid Viscosity ◽  
Characteristic Parameters

An exhaustive description of the dynamics under shear flow of a large number of red blood cells in a dilute regime is proposed, which highlights and takes into account the dispersion in cell properties within a given blood sample. Physiological suspending fluid viscosity is considered, a configuration surprisingly seldom considered in experimental studies, as well as a more viscous fluid that is a reference in the literature. Stable and unstable flipping motions well described by Jeffery orbits or modified Jeffery orbits are identified, as well as transitions to and from tank-treading motion in the more viscous suspending fluid case. Hysteresis loops upon shear rate increase or decrease are highlighted for the transitions between unstable and stable orbits as well as for the transition between flipping and tank-treading. We identify which of the characteristic parameters of motion and of the transition thresholds depend on flow stress only or also on suspending fluid viscosity.

Numerical Analysis of Crack Propagation in Silicon Nitride

2011 ◽  
Vol 490 ◽  
pp. 216-225 ◽  
Author(s):  
Waldemar Karaszewski
Keyword(s):  
Numerical Analysis ◽  
Crack Propagation ◽  
Coefficient Of Thermal Expansion ◽  
Experimental Studies ◽  
Three Dimensional ◽  
Contact Fatigue ◽  
High Hardness ◽  
Rolling Contact ◽  
Three Dimensional Model ◽  
Ring Crack

The properties of ceramics, specifically low density, high hardness, high temperature capability and low coefficient of thermal expansion are of most interest to rolling element manufacturers. The influence of ring crack size on rolling contact fatigue failure has been studied using numerical fracture analysis. Such cracks are very often found on ceramic bearing balls and decrease fatigue life rapidly. The numerical calculation are based on a three dimensional model for the ring crack propagation. The stress intensity factors along crack front are analyzed using a three-dimensional boundary element model. The numerical analysis is verified by experimental studies.

Experimental studies in insect parasitism XIII. The haemocytic reaction of a caterpillar to eggs of its habitual parasite

1965 ◽  
Vol 162 (988) ◽  
pp. 303-318 ◽  
Keyword(s):  
Outer Surface ◽  
Blood Cells ◽  
Genital Tract ◽  
Distal Part ◽  
Experimental Studies ◽  
Ephestia Kuehniella ◽  
Adult Parasite ◽  
Living Tissues ◽  
By Products

Caterpillars of Ephestia kuehniella promptly encapsulate alien parasites, living tissues from other species of insects, and filaments of such inert substances as Polythene and Polyfluorocarbon implanted in their haemocoele. They do not encapsulate eggs of their habitual parasite Nemeritis canescens , and the paper records an investigation of that failure. Eggs of Nemeritis do not repel the haemocytes or prevent them from forming capsule tissue; they escape encapsulation because they do not stimulate the blood cells to react. The property that enables them to avoid evoking a reaction is located on their surface: dead eggs that retained an unaltered surface were not encapsulated, living or dead eggs of which the surface was experimentally altered were encapsulated. Since eggs of Nemeritis possess this protective surface immediately after oviposition, its origin was sought in the adult parasite . The surface of eggs removed from the distal part of the ovarioles is formed by the chorion; eggs removed from the genital tract below the calyx were found to have a visible layer outside the chorion. When eggs bearing this visible layer were removed from several parts of the genital tract and injected into caterpillars of Ephestia , they were not encapsulated. When eggs not bearing the visible layer outside the chorion were removed from ovarioles, and were injected into caterpillars, they always evoked a haemocytic reaction and were usually completely encapsulated. The property of its surface that enables the egg of Nemeritis to avoid evoking a haemocytic reaction in Ephestia is therefore acquired in the region of the calyx, where also the visible layer appears on the outer surface of the chorion. A few by-products of the investigation are mentioned in the discussion.

Experimental studies on coagulation-fibrinolytic activity of white blood cells influenced by endotoxin

1976 ◽  
Vol 8 (6) ◽  
pp. 887-891
Author(s):  
Nobuo Sakuragawa ◽  
Kaoru Takahashi ◽  
Mari Yoshiyama ◽  
Chozo Jimbo ◽  
Kenji Niiya ◽  
...  
Keyword(s):  
Blood Cells ◽  
Fibrinolytic Activity ◽  
White Blood Cells ◽  
Experimental Studies

Analysis of Ceramic Elements with Ring-Crack Defects in Lubricated Rolling Contact

2016 ◽  
Vol 250 ◽  
pp. 43-49 ◽  
Author(s):  
Waldemar Karaszewski
Keyword(s):  
Coefficient Of Thermal Expansion ◽  
Rolling Contact Fatigue ◽  
Experimental Studies ◽  
Three Dimensional ◽  
Contact Fatigue ◽  
High Hardness ◽  
Rolling Contact ◽  
Three Dimensional Model ◽  
Element Analysis ◽  
Ring Crack

The properties of ceramics, specifically low density, high hardness, high temperature capability and low coefficient of thermal expansion are of most interest to rolling element manufacturers. Surface ring cracks on lubricating rolling contact fatigue failure has been studied using numerical fracture analysis. Such cracks are very often found on ceramic bearing balls and decrease fatigue life rapidly. The numerical calculations are based on a three-dimensional model of the ring crack. The stress intensity factors along crack front are analyzed using a finite element analysis. The numerical analysis is verified by experimental studies.

Simulation of Red Blood Cell Mechanical Behavior in Optical Tweezers Experiment Based on a Particle Method

2010 ◽  
Author(s):  
M. T. Ahmadian ◽  
K. Firoozbakhsh ◽  
M. Hasanian
Keyword(s):  
Mechanical Behavior ◽  
Red Blood Cells ◽  
Optical Tweezers ◽  
Blood Cells ◽  
Experimental Studies ◽  
Particle Method ◽  
Living Cells ◽  
Discrete Models ◽  
Particle Methods ◽  
External Forces

Optical tweezers provide an accurate measurement technique for evaluating mechanical properties of the living cells and many experimental studies have been done to understand the behavior of cells due to external forces. Numerical studies such as finite element methods have been used in order to simulate mechanical behavior of the Red Blood Cells (RBCs). Recent studies have shown that the particle methods are useful tools to simulate the mechanical behavior of living cells. Since in microscopic scales, using discrete models are preferred than continuum methods, a particle-based method is used to simulate the deformation of RBC which is stretched by optical tweezers. The cytoplasm of RBC is modeled as a fluid and cell membrane is replaced by a set of discrete particles connected by springs. The results are comparable with previous observations of RBC optical tweezers experiments. It was observed that RBC viscoelastic characteristics are mainly associated with the cytoplasm fluidic properties. In order to understand the behavior and function of living red blood cells, this significant developed model could be implemented to RBC interaction within micocapillaries and constricted zones in blood flow.

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