Rheological properties of blood after whole body gamma-irradiation

The study of rheological properties of blood has special interest; since it is a circulating fluid exposed to shear rates during its life time. This work aims to investigate the influence of whole body gamma irradiation on the rheological properties of rat's blood. The applied shear rate was from 12 to 375 s[-1]. Low shear viscosity [up to 100 s[-1]] depends mainly on the erythrocytes aggregation while the high shear viscosity depends on the erythrocytes deformability. Adult male rats were exposed to 1, 2.5, 3.5, 5, 7 and 9 Gy single doses. The consistency index, apparent viscosity, yield stress and aggregation index were increased after exposure to gamma radiation. The dielectric properties of the erythrocytes, in the low frequency range [60 Hz to 40 kHz], were measured in order to investigate the changes in the membrane surface charge. The results obtained indicate that the viscosity, consistency index and yield stress increased after the exposure to the lowest dose taken; 1 Gy, and continued to increase as the exposure dose increased up to dose 7 Gy and then decrease after exposure to 9 Gy. The relative permittivity and relaxation time showed significant decrease after exposure to the lowest dose and continue to decrease as the dose increased. The obtained results can be attributed to the decrease of membrane surface charge after exposure to gamma radiation. The decrease in the membrane surface charge is known to decrease the repulsion between the cells and increase blood viscosity

quality assurance procedure to monitor mechanical stability on-Linear accelerator-based on stereotactic radiosurgery/sterotatic radio therapy

Stereotactic irradiation, either in the form of stereotactic radiosurgery [SRS] or stereotactic radiotherapy [SRT], of brain lesions requires high precision accuracy in the isocenter, the main determinants were gantry and couch rotations. It is thus necessary to evaluate the isocenter variation due to gantry and couch rotations in the particular setup for SRS/SRT. This paper describes the accuracy of Patients' immobilization and the variation in the isocenter of a Siemens PRIMUS M6/6ST linear accelerator-modified for adapting a couch-mounted radiosurgery system. The accuracy of Patients immobilization was excellent in over twenty patients with 95 setups and 2375 scalp measurements. Ninety two percent of measurements had no displacements from the baseline readings, 7% had 1 mm and one percent had 2 mm displacements. The variations in isocenter position with the table and the gantry rotation were found to be < 0.4 mm with a compounded accuracy of

effect of ultrasound exposure on erythrocytes sedimentation rate

In the present work, the effect of continuous wave [CW] ultrasound with different frequencies and different intensities on erythrocytes sedimentation rate [ESR] have been studied in vitro. Ultrasound exposure to erythrocytes suspended in saline leads to a change in the sedimentation rate of the cells relative to control. It was found that the change in ESR is a function of ultrasonic intensity and frequency as well as the sonification time. This behavior may be attributed to some changes in the cells due to the nonthermal [mechanical] mechanisms of interaction between ultrasonic waves and the suspended cells

role of ultrasound exposure in erythrocytes defense against hemolysis

In the present work, the effect of continuous wave ultrasound with different frequencies and different intensities on erythrocytes defense against hemolysis has been studied. Ultrasound exposure to erythrocytes suspended in saline during hemolysis caused with low different concentrations of HC1, resulted in deceleration of hemolysis relative to control value of HC1. The calculated hemolysis parameter: relative hemolysis rate [H.R][R], showed a critical concentration of KCl below which the hemolysis is decelerated, which means that the ultrasound plays a role in protecting erythrocytes from hemolysis. Also, ultrasound caused some mechanical changes in erythrocytes, and these changes were frequency and intensity dependant

Dielectric properties of red blood cells pretreated by different types of vitamins

The effect of different vitamins [niacin [B5], pyridoxine [B6], thiamin [B1] and ascorbic acid [c]] on human red blood cells [RBC] in vitro has been studied. The dielectric parameters, electric conductivity, the relaxation frequency and dipole moment were measured over a frequency range from 50 Hz to 100 kHz .These parameters were used to follow up the variations occur in the red blood cells after one hour from incubation with such vitamins. The variations in all parameters are compared with the control specimen [without adding vitamins]. The dielectric parameters [epsilon, epsilon], conductivity [sigma] and dipole moment [D] were found to be decreased in comparison with the control one, while the relaxation frequency increases. The obtained results showed that the used vitamins may cause variations in structure and function of red blood cells, and consequently the risks of using large amounts of these vitamins for long time

Structure changes in chicken retina caused by argon laser irradiation

Infrared spectroscopic study has been performed on chicken retina before and after argon laser irradiation. The infrared [IR] spectra obtained from intact retina are in agreement with the polarized [IR] studies on rhodopsin, which indicate that it has an alpha - helical structure with fixed orientation with the membrane normal. Retinae exposed to argon laser light of constant intensity [1mW/cm] and different durations [0.12 and 0.25 sec] at constant temperatures [10, 20 and 30 degree] show no detectable spectral changes, indicating that there is no change in the main helical structure of protein. However, distinct changes occur in the orientation angle of rhodopsin. It was found that the sensitivity of chicken retina for the recovery of the rhodopsin reorientation is more pronounced after laser irradiation of duration 0.12 sec. than that of 0.25 sec. Also the decrease in the chicken temperature by 10 degree could compensate the heating effect due to the increase in laser duration

Electrostatic potentials generated on the head by wearing different types of fabric

The electrostatic potentials [EP] generated on the surface of the head of the human body by different types of fabrics are studied. Hundred healthy volunteers were divided into five equal groups: four test and one control group. Each of the four groups wore caps of different fabrics: 100 percent polyester, 100 percent cotton, 50/50 percent polyester/ cotton and 100 percent wool. The control group was left capless. EP were measured one hour after dressing the cap. EP could not be detected from cotton or wool caps or from controls. In contrast, polyester and polyester/cotton mix caps generated EP. The EP induced during daytime were higher than at night due probably to the higher temperatures prevailing during the day. Friction between polyester-containing caps and the human scalp generates electric charges and the scalp becomes positively charged. A series of induced EP is generated in the intracranial structures. Opposite sign charges on the opposing surfaces of the subarachnoid space, the four cerebral ventricles and cerebral hemispheres create an [electrostatic field] across each of them. The latter may have an injurious effect on the nerve cells of the cerebral hemispheres and on the constituents and circulation of the cerebrospinal fluid and blood in the skull. These disorders may eventually affect the brain centers and result in clinicopathologic manifestations

Electrostatic potentials generated on the chest by wearing different types of fabrics

The electrostatic potentials [EP] generated on the surface of the upper part of the human body by different types of fabrics are studied. 40 healthy volunteers were divided into 5 equal groups. In the control group, the upper half of the body was bare during the test periods. Each of the other 4 groups dressed shirts of different fabrics: 100 percent polyester, 100 percent cotton, 50/50 percent polyester/cotton and 100 percent wool. EP were measured one hour after dressing the shirt. EP could not be detected from cotton or wool shirts, or from controls. Polyethylene shirts recorded the highest EP followed by the polyester/cotton mix. The EP generated during the day were higher than at night probably due to the higher temperature prevailing during the day. The polyester-containing shirts may have injurious effect on the chest. Friction between polyester shirt and the skin generates electric charges, and the skin is positively charged. A series of induced EP is generated in the intrathoracic organs. Opposite sign charges on the opposing surfaces of lung and heart create an "electrostatic field" across them, which may cause respiratory and cardiac derangement

Synthesis of some new-isoxazolines, isoxazoles and-cyclohexen-ones derived from naphthalene of anticipated pesticidal activity

Naphthalenes are known for their widespread biological activity. Also, the pesticidal and antiviral properties have been reported for some cyclohexenone, isoxazoline and isoxazole derivatives. Such a broad spectrum of biological activities prompted us to synthesise some new isoxazolines, isoxazoles and cyclohexenones bearing the naphthalene moiety for biological evaluation. Thus, it is found in the present investigation that when hydroxyl-amine hydrochloride is allowed to react with 3-aryl-l-[2'-naphthyl]-2-propen-1-ones la-d in boiling pyridine; the oximes 2a-d are obtained, respectively, in good yield

Nitrogenous heterocyclic compounds: some new naphthyl-pyrazolines and their dehydrogenation with tetrachloro-obenzoquinone to the corresponding pyrazoles

Compounds: Some New Naphthyl-Pyrazolines and their Dehydrogenation with Tetrachloro-o-benzoquinone to the Corresponding Pyrazoles SEVERAL pyrazoline and pyrazole derivatives are well known for their bactericidal and fungicidal activities. Also, different pyrazoles are now being used as systematic insecticides as well as insecticide stabilizers. Such a broad spectrum biological activities encouraged us to synthesise newer pyrazolines and -pyrazoles derived from naphthalene for biological evaluation. Thus, in the present investigation, it is found that when 3-aryl-l-[2'-naphthyl]-2-propen-l-ones la-d are allowed to react with hydrazine