34 research outputs found

    Assessment of value of protraction angle and functional disorders of motion segments of cervical spine in bus drivers

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    Introduction: Cervical segment is a part of the spine which is the most exposed to stress and dysfunction. Aim: The aim of the study is to analyze the body posture of bus drivers and, especially, functional assessment of cervical spine mobility segments. Material and methods: The study included a group of 40 people, consisting of professionally active drivers working in public transport, 20 of whom were the men under 40, and the remaining 20 were the men over 40. The study used the original study card. Results: There was dependence between the subjects' length of service and the appearance of hand numbness. There was dependence between protraction angle and length of service. Most of the study subjects (67.5%) report the presence of back pain syndromes. Among the study subjects, 45.0% declare that they do sports / physical activity improving their condition. In the case of rectus abdominis muscle strength, the majority of the surveyed (60.0%) cannot sit unassisted. Conclusions: The bus driver is exposed to a lot of stress every day, resulting, i.a. from the responsibility he bears for passengers in the vehicle, as well as from heavy traffic, which leads to changes in myofascial tensioning, resulting in the incidence of pain.

    Noninvasive evaluation of renal tissue oxygenation with blood oxygen level-dependent magnetic resonance imaging early after transplantation has a limited predictive value for the delayed graft function

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    Purpose: The aim of this study was to evaluate the feasibility of renal oxygenation assessment using blood oxygen level-dependent (BOLD) magnetic resonance imaging (MRI) in the early period after kidney transplantation and to estimate its prognostic value for delayed graft function. Material and methods: Examinations were performed in 50 subjects: 40 patients within a week after the kidney transplantation and 10 healthy controls, using T2*-weighted sequence. Measurements in transplant patients were correlated to basic laboratory parameters in the early period after transplantation and at follow-up. Results: Examinations of seven patients (18%) were rejected due to their poor technical quality. Mean R2* values in transplant recipients were lower than in controls (11.6 vs. 15.9 Hz; p = 0.0001). An R2* value of 0.28 Hz was calculated as the minimal detectable change. There was no relation between R2* values and laboratory parameters. However, patients eGFR Ôëą 40 ml/min/1.73 m2 presented higher R2* values than recipients eGFR 0.7). Conclusions: Evaluation of renal graft oxygenation using BOLD MRI is technically challenging in the early period after transplantation. An R2* value of 0.28 Hz may in practice be considered as the minimal detectable change. The delayed graft function seems not to be dependent on early oxygenation values. Further, large-scale studies are necessary to confirm the latter observation

    Synteza i modyfikacja nanocz─ůstek TiO2

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    Warunki atmosferyczne a nagłe schorzenia układu sercowo-naczyniowego

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    Choroby uk┼éadu sercowo-naczyniowego s─ů wci─ů┼╝ pierwsz─ů przyczyn─ů zgon├│w w Polsce. Zapadalno┼Ť─ç na nag┼ée schorzenia sercowo-naczyniowe nie jest jednakowa we wszystkich porach roku, co mo┼╝e przemawia─ç za tym, i┼╝ okre┼Ťlone warunki atmosferyczne sprzyjaj─ů wyst─Öpowaniu ostrych zespo┼é├│w wie┼äcowych, udar├│w m├│zgu czy migotania przedsionk├│w. Mechanizm tego zwi─ůzku nie jest do ko┼äca wyja┼Ťniony. Wydaje si─Ö, ┼╝e istotne znaczenie w kszta┼étowaniu tej relacji mo┼╝e mie─ç pobudzenie uk┼éadu wsp├│┼éczulnego w okresie zimowym przez nisk─ů temperatur─Ö, co prowadzi do obkurczenia ┼éo┼╝yska naczyniowego, wzrostu ci┼Ťnienia t─Ötniczego i zwi─ůzanej z tym destabilizacji blaszek mia┼╝d┼╝ycowych. Nie bez znaczenia zim─ů s─ů r├│wnie┼╝ kr├│tszy czas nas┼éonecznienia w ci─ůgu dnia, niskie ci┼Ťnienie atmosferyczne oraz wi─Öksza pr─Ödko┼Ť─ç wiatru. Z kolei w okresie letnim czynnikiem zwi─ůzanym z niekorzystnym rokowaniem jest bardzo wysoka temperatura. Dotychczasowe wyniki bada┼ä wskazuj─ů, ┼╝e na zdrowie cz┼éowieka wp┼éywaj─ů nie tylko warunki pogodowe panuj─ůce w danym dniu, ale tak┼╝e zmiany pogody w okresie kilku, kilkunastu dni wcze┼Ťniej. Elementami zwi─Ökszaj─ůcymi podatno┼Ť─çna niesprzyjaj─ůce warunki pogodowe s─ů jednak: starszy wiek, p┼ée─ç m─Öska, brak aklimatyzacji i obci─ů┼╝enie innymi schorzeniami. By─ç mo┼╝e zdefiniowanie niesprzyjaj─ůcego profilu atmosferycznego dla okre┼Ťlonej strefy klimatycznej oka┼╝e si─Ö pomocne w zapobieganiu nag┼éym incydentom sercowo-naczyniowym i jednocze┼Ťnie mo┼╝e pozwoli─ç zredukowa─ç ich cz─Östo┼Ť─ç i konsekwencje. S┼éowa kluczowe: warunki atmosferyczne, ostry zesp├│┼é wie┼äcowy, udar m├│zgu, migotanie przedsionk├│

    Synthesis and Characterization of Low Loss Dielectric Ceramics Prepared from Composite of Titanate Nanosheets with Barium Ions

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    We report a strategy for preparing barium titanate precursor, being the composite of titanate nanosheets (TN) with barium ions (Ba-TN), which subjected to step sintering allows obtaining TiO2 rich barium titanate ceramics of stoichiometry BaTi4O9 or Ba2Ti9O20. These compounds are important in modern electronics due to their required dielectric properties and grainsÔÇÖ size that can be preserved in nanometric range. The morphology studies, structural characterization, and dielectric investigations were performed simultaneously in each step of Ba-TN calcinations in order to properly characterize type of obtained ceramic, its grainsÔÇÖ morphology, and dielectric properties. The Ba-TN precursor can be sintered at given temperatures, so that its dielectric permittivity can be tuned between 25 and 42 with controlled temperature coefficients that change from negative 32ÔÇëppm/┬░C for Ba-TN sintered at 900┬░C up to positive 37ÔÇëppm/┬░C after calcination at 1300┬░C. XRD analysis and Raman investigations performed for the Ba-TN in the temperature range of 900├Ě1250┬░C showed that below 1100┬░C we obtained as a main phase BaTi4O9, whereas the higher calcinations temperature transformed Ba-TN into Ba2Ti9O20. Taking into account trend of device miniaturization and nanoscopic size requirements, temperatures of 900┬░C and 1100┬░C seem to be an optimal condition for Ba-TN precursor calcinations that guarantee the satisfactory value of dielectric permittivity (╬Á=26 and 32) and ceramic grains with a mean size of ~180ÔÇënm and ~550ÔÇënm, respectively

    Dielectric Properties and Characterisation of Titanium Dioxide Obtained by Different Chemistry Methods

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    We made comparison of titanium dioxide powders obtained from three syntheses including sol-gel and precipitation methods as well as using layered (tetramethyl)ammonium titanate as a source of TiO2. The obtained precursors were subjected to step annealing at elevated temperatures to transform into rutile form. The transformation was determined by Raman measurements in each case. The resulting products were characterised using Raman spectroscopy and dynamic light scattering. The main goal of the studies performed was to compare the temperature of the transformation in three titania precursors obtained by different methods of soft chemistry routes and to evaluate dielectric properties of rutile products by means of broadband dielectric spectroscopy. Different factors affecting the electrical properties of calcinated products were discussed. It was found that sol-gel synthesis provided rutile form after annealing at 850┬░C with the smallest particles size about 20ÔÇënm, the highest value of dielectric permittivity equal to 63.7, and loss tangent equal to 0.051 at MHz frequencies. The other powders transformed to rutile at higher temperature, that is, 900┬░C, exhibit lower value of dielectric permittivity and had a higher value of particles size. The correlation between the anatase-rutile transformation temperature and the size of annealed particles was proposed.This work was financially supported by the National Science Center (Poland) grant awarded by Decision no. DEC-2011/03/D/ST5/06074. The authors are grateful to Professor Adam Tracz from the Polish Academy of Science in Lodz for his help in performing SEM investigations

    Wp┼éyw zmian strukturalnych na dynamik─Ö relaksacyjn─ů i nisko-cz─Östoliwo┼Ťciow─ů dynamik─Ö wibracyjn─ů szkie┼é polimerowych

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    Les ├ętudes r├ęalis├ęes ont ├ęt├ę consacr├ęes ├á la d├ętermination de l'influence du vieillissement physique sur la nanostructure et les relaxations mol├ęculaires de homopolym├Ęres et copolym├Ęres amorphes. Les techniques utilis├ęes ├ętaient les difussions Raman et de RX, les spectrospcopies di├ęlectrique et m├ęcanique, ainsi que la calorim├ętrie. On a constat├ę que la structure des homopolym├Ęres amorphes devient plus homog├Ęne par lissage du constraste de constante ├ęlastique ├á l'├ęchelle nanom├ętrique. Au contraire, la structure ├á l'├ęchelle nanom├ętrique des copolym├Ęres ├ętudi├ęs tend ├á ├¬tre plus h├ęt├ęrog├Ęne par vieillissement. Cela est du ├á l'agr├ęgation d'unit├ęs chimiques semblables ├á l'├ęchelle de quelques nanaom├Ętres. Les techniques utilis├ęes pour la d├ętection de la mobilit├ę mol├ęculaire ont permis d'observer une diminution du recouvrement des relaxations a et b pendant le vieillissementLYON1-BU.Sciences (692662101) / SudocSudocFranceF
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