50 research outputs found

    Učinci gama-zračenja na folikule jajnika

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    In order to observe the morphological and endocrinological changes of the rat and mouse ovarian follicles by gamma-radiation, rats were whole-body irradiated with doses of 3.2 Gy and 8.0 Gy and mice with 2.9 Gy and 7.2 Gy. Sections of ovaria were examined by light microscopy. Concentrations of progesterone, testosterone, and estradiol in ovarian homogenate were determined by radioimmunoassay techniques. Gamma-radiation resulted in the increased percentage of atretic follicles in the groups killed on day 0, day 4, and day 8 after irradiation. The decrease in granulosa cell viability was found in animals killed on day 4 after irradiation. The finding of the high ratio of testosterone to estradiol compared to that of progesterone to testosterone suggests that aromatase activity — steroid biosynthesis from testosterone to estradiol — in granulosa cell could be affected by gamma-radiation.U radu su procjenjivane strukture i endokrinološke promjene u folikulima jajnika štakorica i mišica izazvane gama-zračenjem. Štakorice su bile izložene zračenju od 3,2 Gy ili 8,0 Gy, a mišice od 2,9 Gy ili 7,2 Gy. Životinje su usmrćene dana 0, dana 4, odnosno dana 8 nakon ozračenja. Rezovi debljine 7 µm pripremljeni su za mikroskopiranje. Koncentracije progesterona, testosterona i estradiola u homogenatu jajnika određene su specifičnim radioimunoesejem. Gama-zračenje uzrokovalo je povećanje broja atretičnih folikula u obje skupine životinja usmrćenih 4 odnosno 8 dana nakon ozračivanja. Gama-zračenje također je smanjilo životni vijek granuloza stanica u skupinama usmrćenim 4. dan nakon ozračivanja. Utvrđeno povećanje omjera testosterona prema estradiolu u usporedbi s omjerom progesterona prema testosteronu upućuje na to da gama-zračenje utječe na aktivnost aromataze u steroidnoj biosintezi testosterona u estradiol u granuloza stanicama

    Acute Diffuse Phlegmonous Esophagogastritis: A Case Report

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    Acute phlegmonous infection of the gastrointestinal tract is characterized by purulent inflammation of the submucosa and muscular layer with sparing of the mucosa. The authors report a rare case of acute diffuse phlegmonous esophagogastritis, which was well diagnosed based on the typical chest computed tomographic (CT) findings and was successfully treated. A 48-yr-old man presented with left chest pain and dyspnea for three days. Chest radiograph on admission showed mediastinal widening and bilateral pleural effusion. The patient became febrile and the amount of left pleural effusion is increased on follow-up chest radiograph. Left closed thoracostomy was performed with pus drainage. A CT diagnosis of acute phlegmonous esophagogastritis was suggested and a surgery was decided due to worsening of clinical condition of the patient and radiologic findings. Esophageal myotomies were performed and the submucosal layer was filled with thick, cheesy materials. The patient was successfully discharged with no postoperative complication

    Estimation of Electromagnetic Field Penetration into Concrete Buildings Using a Theoretical Approach Considering External Environmental Factors

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    In this paper, we propose a theoretical approach to estimate the power level of electromagnetic waves radiated into a structure by a specific external source. The target structure is a multistory building on a university campus that is used primarily for academic purposes and is much larger than the target wavelength. To verify the accuracy and efficiency of the proposed theoretical approach, measurements were carried out and a commercially available simulation tool, Wireless Insite, was adopted. We then analyzed the influence of an area of vegetation as an external environmental factor that could affect the radiated electromagnetic waves because of its location in front of the target structure. For this, a precise simulation environment was designed to derive the quantitative values of the electromagnetic attenuation caused by the external environmental factor. Furthermore, those values were applied to the theoretical approach. The results of the theoretical approach accounting for the external environmental factor were similar to those of the actual measured results. The results were also similar to those of the simulation tool, Wireless Insite, but the theoretical approach provided more efficient analysis results in terms of time consumption and computer resources

    Diet and Airway Obstruction: A Cross Sectional Study from the Second Korean National Health and Nutrition Examination Survey

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    Background/Aims: Several dietary factors, such as antioxidant vitamins, have potential roles in the development of obstructive lung diseases. However, the results of studies on the relationships between dietary factors and obstructive lung diseases are inconsistent. The aim of this study was to determine which nutrients are related to airway obstruction (AO) in the Korean population.&Methods: We used data obtained as part of the Korean National Health and Nutrition Examination Survey (NHANES II) in 2001. Analysis was restricted to 1,005 adults who were 18 years of age and older, who had two or more acceptable spirometry curves, and who had participated in the nutrition examination survey. AO was defined as the ratio of forced expiratory volume in one second (FEV1) to forced vital capacity (FVC) of less than 0.7.&Results: Of the 1,005 study subjects, 78 (7.8%) had AO. Statistically significant factors associated with AO were 55 years of age or older (p = 0.032), central obesity (p = 0.047), hypertension (p < 0.001), smoking of 20 pack-years or more (p < 0.001), low income (p < 0.001), and low dietary protein intake expressed as a ratio of protein to recommended dietary allowance for Koreans (p = 0.037). Multiple logistic regression analyses revealed four factors that were independently associated with AO: smoking of 20 pack-years or more (odds ratio [OR], 5.801; p < 0.001), hypertension (OR, 3.905; p < 0.001), low protein intake (OR, 0.992; p = 0.004), and low income (OR, 1.962; p = 0.018).&Conclusions: In the Korean NHANES, smoking, hypertension, and low income were related to AO. Among dietary factors, only low protein intake was associated with AO

    Impact of Absorbers on the Shielding Effectiveness of Metallic Rooms with Apertures

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    An electromagnetic field penetrating through an aperture or slot of a metallic enclosure generates many standing-waves due to the resonance inside the metallic enclosure, which results in reduced shielding performance. This paper examines the effect of absorbent material (absorber) to improve shielding effectiveness (SE) of large metallic rooms with apertures or slots. First, a theoretical formulation to extract the Q-factor of an absorber with any shape is proposed. Using this, the contribution of the absorber to the SE improvement of a shielded room with different sized circular apertures was investigated. Second, the resonant mode density inside the shielded room was classified into non-resonant, under-moded, and over-moded states with an increase in frequency, and the effect of the absorber in each frequency range was examined. The analysis was conducted through numerical simulation using a commercial full-wave simulator and experimental measurement using a fabricated actual shielded room and commercial absorbers. The accuracy of the analysis results was verified through the comparison of simulated and measured results. The analysis results ensured that the absorber was not effective in improving the SE in the non-resonant state of the metallic room. It was also confirmed that the absorber was effective in improving the SE in the over-moded state of the metallic room where a severe standing-wave occurs. In addition, the SE improvement level differed depending on the location of the absorber in the room
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