Background and Objective: Laser is a source of electromagnetic radiation. Laser therapy has a kind of natural and biological effect on tissue which acts via energy and light power. Today’s the use of infrared and red RAYS from low-power lasers have been established as a routine way for the treatment of diseases. Considering the important role of laser in biological sciences this study was done to compare the effect of red and infrared spectrum low level of laser RAYS on Rat Seminiferous tubules.Materials and Methods: This experimental study was done on 40 male Rat which divided in four groups including one control and three experimental. In the first experimental group, the right testis of the rats was exposed to a mixture of 300 Hz infra-red ray for 7 minutes and 300 Hz red spectrum for 1 minute daily. In the second experimental group, the right testes were exposed to the 300 Hz infra-red ray for 8 minutes for 40 seconds daily. In the third experimental group, the right testes were exposed to 80 Hz infra-red for 5 minutes and 80 Hz red ray for one minute daily. The controls did not receive any RAYS. After 15 days, testes were dissected, fixed and stained for histological processing. Thickness of seminiferous tubules and lumen as well as the thickness and area of seminiferous epithelium were measured. The concentration of testosterone was determined with radioimmunoassay. Data was analyzed with SPSS-13 software and ANOVA test.Results: There was a significant difference in the thickness of seminiferous tubules, thickness of lumen space and thickness of epithelium between first (i.e., the mixture of 300 Hz red and infra-red lasers), second (300 Hz infra-red laser) and the third experimental groups (80 Hz red and infra-red lasers) (P<0.05). But no difference was found between the first group and control. The serum testosterone concentration did not show any differences between experimental and control.Conclusion: This study showed that morphologic and morphometric alterations have direct relation with laser energy density.

Nowadays ionizing beams such as gamma RAYS are used to remove organic and inorganic contaminants from wastewater and sewage sludge. The objective of this study was to investigate the effects of gamma RAYS and titanium dioxide nanoparticles on the concentration of lead and zinc in aqueous solution at different pH. For this purpose, the effect of gamma RAYS at 4 levels (0, 4, 8 and 16 kGy) and chemical modifier of titanium dioxide at three levels (0, 2 and 4 g. l-1 ) with 0 and 10% methanol in water solutions with different pH (2, 4 and 6) on the removal of Pb and Cu were investigated. The experiment was performed as a factorial in a completely randomized design. The results showed that the lead and copper concentrations decreased with increasing pH. The concentrations of copper at pH level of six, 16 kGy of gamma radiation and the level of 4 g. l-1 of titanium dioxide (without methanol) decreased more. The concentration of lead at the level of pH six and 16 kGy of gamma radiation and levels of 2 and 4 g. l-1 of titanium dioxide (without methanol and with methanol) had a further decrease. Titanium dioxide showed the highest effect and gamma ray had the lowest effect on the removal of copper and lead from aqueous solution.

IntroductionChest radiography is one of the most usual diagnostic tools for respiratory distress. The aim of this study was to assess the specificity, sensitivity and clinical value of chest radiography of neonates with respiratory distress.Methods and MaterialsA descriptive- analytical study was conducted on 102 neonates that were in neonatal intensive care unit of Imam Reza and 22 Bahman Hospitals because of respiratory distress. After confirming the neonate’s respiratory distress and taking chest radiography, the radiography was described by a radiologist and final diagnosis was confirmed.ResultsMost of the neonates (64.7%) were born with caesarian section and were premature (78.4%). Respiratory distress syndrome (RDS) was the most common reason for respiratory distress (38.2%). Chest radiography had the most sensitivity and specificity in pneumothorax and hernia (100%). For pneumosepsis, radiography had 73% sensitivity and 87% specificity, for RDS the sensitivity and specificity were 35% and 82% respectively, for congenital heart disease sensitivity of zero and specificity of 98% and for Transient tachypnea of neonates (TTN) sensitivity of zero and specificity of 100%. The conformity of clinical and radiography was also calculated as 79.4% in respiratory distress.ConclusionAlthough chest radiography is used as one of the most usual and accessible diagnostic tools in respiratory distress syndrome, but inaccurate specificity and sensitivity in some disease must be considered, especially in neonates.

Background and purpose: Apoptosis or programmed cell death is a process of cell suicide. Ionizing radiation is one of the stimuli for apoptosis, acting through DNA damage. In the present study, effects of X-RAYS induced apoptosis in HL60 cells, as well as the protective effects of Stem Cell Factor (SCF) in inhibiting X-ray induced apoptosis have been evaluated.Materials and methods: HL60 cells were exposed to 5 Gy of x-ray and the effect of time on the percentage of apoptotic cells was studied. One group of cells was incubated in medium containing SCF at 37°C for 1 h before X-ray exposure. Other groups of cells were incubated in media containing SCF, MAPK, PI3K and PKC inhibitors as the cellular pathway proteins, and the X-ray induced apoptosis was studied.Results: The X-ray induced apoptosis show a graduall increase from 12h to 60h after X-ray. The SCF attenuated the percentage of apoptotic cells when cells were treated with SCF 1 h before X-ray. X-RAYS induced apoptosis partially attenuated by a combination treatment of SCF and PKC and PI3K inhibitors, but it was not inhibited by the SCF and ERK inhibitors.Conclusion: SCF protected cells against X-RAYS through activation of MAPK pathway.

Natural radionuclides in soil constitute a significant component of the background exposure sources of the population. A meaningful contribution to the total dose from natural sources comes from terrestrial radionuclides such as 238U, 232Th and 40K. Materials and Methods: The concentrations of natural radionuclides of 238U, 232Th and 40K in surface soil (5 cm depth) of Tehran have been measured by gamma spectrometry. The samples were dried and homogenized and measured for 60k seconds after radionuclides secular equilibrium, using a high purity germanium (HPGe) gamma-ray spectrometer. The high energy resolution of this type of detector is particularly useful for activity measurements of uranium and thorium chain members due to their complex spectras. The absorbed dose rates in air were also measured by using ionization-chamber at the point where soil samples were collected which includes terrestrial and COSMIC RAYS. Results: The natural gamma emitting terrestrial radionuclides in soils are directly relevant to outdoor exposure. The average activity concentrations of 238U, 232Th and 40K in different districts of Tehran were found to be 24, 28 and 635 Bq kg-1, respectively. The average outdoor gamma absorbed dose rate in air at 1 meter above ground was calculated as 102 nGy h-1. By using the data obtained in this study the average annual effective dose equivalent for a person living in Tehran was found to be about 125 Sv. Conclusion: According to data of 66 soil samples measurement covering 22 districts in Tehran, the average outdoor gamma dose rate in air due to terrestrial and COSMIC radiation was found to be about 102 nGy h-1 and the average annual effective dose equivalent for a person living in Tehran is about 125 Sv.

Introduction: More than 99% of electrical energy in diagnostic X-Ray tubes converts to heat. This process causes limitation in medical applicability especially in higher intensity for diagnostic and treatment purposes.Objective: To decrease the applicability limitation in x-ray generation via higher cooling rateMaterials and Methods: In this study, a novel anode was proposed with special geometric design and use of new materials in order to obtain higher cooling rate. In doing so, a conventional anode with 9 Cm diameter and 127 Cm2 area, was compared with the proposed anode made of an alloy of chromium, copper and silver with 27 Cm diameter and 1145 Cm2 equipped with a tungsten ring in the same condition. Both anodes were placed inside a container without air flow and heated up to 1200oC using a plasma flame. Then, the anode temperatures were measured and recorded during cooling using a contact thermometer for three times and finally means and standard deviation and also the respective cooling rates were calculated.Results: In both anodes, the cooling modes were exponential but the cooling rates were respectively different, (approximately 180oC/min for the proposed anode) and (approximately 76oC/min for the conventional one) at 1200oC.Conclusions: In comparison with the conventional anode, the proposed anode has higher strength and higher cooling rate. Therefore, it can lead to lower limitation in selecting exposure factors such as mAs and kVp in medical practices.

During deep space missions, astronauts are exposed to highly ionizing radiation, incl. neutrons, protons and heavy ions from galactic COSMIC RAYS (GCR), solar wind (SW) and solar energetic particles (SEP). This increase the risks for cancerogenisis, damages in central nervous system (CNS), cardiovascular diseases, etc. Large SEP events can even cause acute radiation syndrome (ARS). Long term manned deep space missions will therefor require unique radiation protection strategies. Since it has been shown that physical shielding alone is not sufficient, this paper propose pre-flight screening of the aspirants for evaluation of their level of adaptive responses. Methods for boosting their immune system, should also be further investigated, and the possibility of using radiation effect modulators are discussed. In this paper, especially, the use of vitamin C as a promising non-toxic, cost-effective, easily available radiation mitigator (which can be used hours after irradiation), is described. Although it has previously been shown that vitamin C can decrease radiation-induced chromosomal damage in rodents, it must be further investigated before any conclusions about its radiation mitigating properties in humans can be concluded.

Geomagnetic storms disrupt space navigation systems such as satellite with rapid and large changes in particle flux. To study the effects of COSMIC RAYS and calculate the rate of faults and errors and provide a suitable shield against them, we need to know the energetic particles flux. In the present work, we have obtained protons flux and energy range by simulating in different solar cycles and in 4 major solar flare events. In the first step of the proton flux simulation, we have used OMEREH. software; We have then compared the obtained data from the simulation with the experimental data from AMS collaboration and they were in a good agreement with each other. In the next step, first we have determined satellite’ s coordinates and properties using OMEREH; then we have calculated the flux of energetic protons that collide to a typical satellite in Leo orbit at the time of flares occurrence. The number of solar events increases in solar maximum. Therefore, these analyses should be done carefully and the design should be more significant in long-term space missions.

Nowadays, the multiple drug resistance and resistance to different antimicrobial are observed in a wide variety of bacteria. One of these agents is U.V. ray that sometimes used to sterilize the operation room space and utensils and gamma ray to sterilize some medical Instruments such as disposal syringes & cottons and etc. If resistance emerges against the above mentioned factor, fighting microbs by these factors will encounter more problems.Therefore; In this research the multiple resistance of pathogenic strains of S. aureus isolated from different infections were studied. The M.I.C and M.B.C to penicillins were determined, using dilution tube method and plate cultured respectively. The influence of U.V rayon the growth of bacteria under hood of laminator flow was measured by photon-meter, during different times (0, 30, 60, 120, 240 Sec) at intensity of radiation 0.25 J/m2.S-1. The study of gammd rayon the growth of these bacteria was done by Iridium 192 source projector sentinel 660 as a gamma ray generator. Gamma irradiation was used at the intensity of 20 Gy/min and with dose of 500, 750 and 1000 Gray. The statistical study of the results obtained in different experiments was processed using S.A.S software. The standard strains were used as control and comparison. In these results, the strains of S. aureus showed maximum and minimum of MIC = 0.125%-65mg/ml and MBC=1-128 mg/ml, respectively. For the study of bacterial level of resistance to U.V. ray, The most important resistance strains to antibiotics have been selected. The mean number of the colonies grown in the culture medium area after 120 and 240 seconds of U.V. radiation were Log N/No=21.8, 6.9 respectively in the strain of Staphylococcus. Resistance of isolated strains of S. aureus in this research was higher than those of standard strains.