Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 14

Liczba wyników na stronie
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych:  X-ray
help Sortuj według:

help Ogranicz wyniki do:
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
Background. Within the medical facilities provided by state healthcare services, a universally applied technique for patient diagnosis and treatment relies on ionising radiation; for example in radiotherapy and X-ray (ie. examination). Human exposure to such radiation is not however entirely free of associated health risks. Objectives. To determine and estimate the numbers and types of X-ray based medical procedures that are performed in general and dental radiography, mammography and computer tomography on patients from the Mazovian province in Poland, which included children, women and men subjects. Material and Methods. The numbers of patient subjects undergoing X-rays was estimated by surveying the patient intake in X-ray testing rooms within the healthcare facilities of the Mazovian province. Questionnaires were either dispatched by mail to such healthcare centres or were completed by the X-ray operating staff during the testing of quality control. Results so obtained from the latter, were compared to entries from the X-ray rooms’ register Results. During 2009, the number of X-rays performed were 7612046 equivalent to 1460 examinations per 1000 inhabitants. The majority were done on women ie. 3847961 (50.55%), followed by 3193781 (41.96%) on men and 570 304 (7.49%) for children. Conclusions. Results indicated that the predominating medical procedure used of this type, was for making general diagnoses; especially through using chest radiography. Others included, in descending order; dental X-ray (mainly intra-oral examination), computer tomography (mainly CT head examinations) and mammography procedures. It was also found that the annual numbers of having X-rays has increased compared to previous years.
This study investigated the changes in the supramolecular structure of pine wood cellulose in situ treated by various of doses gamma radiation (from 20 kGy to 9000 kGy). From the dose of 120 kGy the degree of crystallinity (xc) of wood cellulose slightly decreased, while at the dose of 500-4500 kGy dropped rapidly. At 9000 kGy occures a total degradation of cellulose, both crystalline and amorphous. Along with the increase in the gamma radiation of wood, both the crystallinity degree and the average size of the crystallites of cellulose decrease. The curve of changes in the crystallinity degree was similar to that of the changes in the average size of the crystallites of cellulose.
A new crystal form of papain from the latex of Carica papaya, complexed with an inhibitor (Z-Arg-Leu-Val-Gly-CHN2) was obtained by the vapor-diffusion method using a methanol/ethanol mixture as a precipitant. The slat-like crys­tals are monoclinic, space group P2 1, with unit cell parameters a = 42.6 A, b = 49.8 A, c = 50.5 A, β= 111.9°, and contain one molecule in the asymmetric unit. The crystals are stable in the X-ray beam and diffract beyond 1.8 A. A molecular model has been placed in the unit cell by molecular replacement.
The biologically active conformation of thymopoietin, based on X-ray data reported for discontinuous thymopoietin-like motif of G-actin, is proposed. The conformation is compared with that resulting from the prediction made by the method of Chou & Fasman (Annu. Rev. Biochem. 47, 251-276, 1978) and Rost & Sander (Methods Enzymol. 266, 525-539, 1996).
The effects on human erythrocytes of water-derived radicals generated by X-rays were studied under anaerobic conditions and in the presence of oxygen. Erythrocyte damage was estimated on the basis of the reduced GSH and MetHb content in the erythrocytes, the -SH group content in the membrane proteins and the amount of K+ released from the erythrocytes. The results obtained show that the level of reduced GSH was the most sensitive indicator of erythrocyte damage by X-rays followed by the efflux of K+. The processes of GSH oxidation took place most rapidly under air. At a dose of 100 Gy, the level of GSH fell to about 50%, whereas under argon and N2O to about 75% and 65%, respectively. A slight increase in the efflux of K+ was observed in preparations irradiated under air. However, when erythrocytes were irradiated under argon and N2O, the loss of K+ occurred at a dose 8-times higher. Changes in the remaining parameters occurred at considerably higher doses. On the basis of the results obtained one can say that oxygen is a factor increasing the toxicity of OH radicals towards erythrocytes; however, e-aq present in the system can cause a decrease in damage to certain cellular components.
10
Content available remote

History of Polish gastrointestinal radiology

58%
As early as several days after the publication of the information concerning Roentgen's discovery the first radiological examinations were performed in Poland. The new method was immediately introduced into medical practice, including gastroenterology. In that pioneer period the most important works were those by Walery Jaworski who was the first man in the world to perform an X-ray of gall stones as well as the stomach with the use of a contrast medium. In its more-than-a-hundred-year history Polish gastrointestinal radiology has attempted not only to catch up with the world science, but it also has made a considerable contribution to its development.
We examined the response to hydrogen peroxide of two L5178Y (LY) sublines which are inversely cross-sensitive to hydrogen peroxide and X-rays: LY-R cells are radioresistant and hydrogen peroxide-sensitive, whereas LY-S cells are radiosensitive and hydrogen peroxide-resistant. Higher initial DNA breaks and higher iron content (potentially active in the Fenton reaction) were found in the hydrogen peroxide sensitive LY-R cells than in the hydrogen peroxide resistant LY-S cells, whereas the antioxidant defence of LY-R cells was weaker. In particular, catalase activity is twofold higher in LY-S than in LY-R cells. The content of monobromobimane-reactive thiols is 54% higher in LY-S than in LY-R cells. In contrast, the activity of glutathione peroxidase (GPx) is about two times higher in LY-R than in LY-S cells; however, upon induction with selenium the activity increases 15.6-fold in LY-R cells and 50.3-fold in LY-S cells. Altogether, the sensitivity difference is related to the iron content, the amount of the initial DNA damage, as well as to the efficiency of the antioxidant defence system. Differential nuclear translocation of p65-NF-kappaB in LY sublines is due to the more efficient antioxidant defence in LY-S than in LY-R cells.
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.