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Developmental Neurotoxicity in Mice Neonatally Co-exposed to Environmental Agents : PCB, PBDE, Methyl Mercury and Ionized Radiation - Interactions and EffectsFischer, Celia January 2008 (has links)
This thesis investigates the neurotoxic effects in mice neonatally co-exposed to different toxic environmental agents during a defined critical period of the brains's rapid growth and development. Environmental toxic agents are incorporated in our environment. The agents investigated in this thesis are ortho-substituted polychlorinated biphenyls (PCBs 52, and 153), co-planar PCB (PCB 126), polybrominated diphenyl ether (PBDE 99), methyl mercury (MeHg), and γ-radiation. Several epidemiological studies show that human exposure to environmental agents during early development can affect childhood cognitive development. The brain growth spurt (BGS) is defined by rapid growth and development of the immature brain. For rodents (rats and mice) the BGS is postnatal spanning the first 3-4 weeks after birth. For humans this period begins during the third trimester of pregnancy and continues throughout the first two years of life. Several studies have shown that the BGS period of the brain's development renders the brain vunerable and susceptible to insults caused by environmental agents. The combinations of environmental agents used in this thesis were: PCB 52 + PBDE 99, PCB 153 + MeHg, PCB 126 + MeHg, PBDE 99 + MeHg, and γ-radiation + MeHg. The studies presented in this thesis show that co-exposure to low doses of environmental agents lead to interaction effects. These effects of interaction include defective spontaneous behavior, diminished habituation capabilities and hyperactive condition, decreased learning and memory abilities, and reduction in the nicotinic cholinergic receptor densities. Traditionally environmental agents are evaluated one at a time to investigate their effects of toxicity. This thesis indicates that the effects of interaction caused by co-exposure were often seen at doses where exposure to the individual environmental agent alone did not cause any effect. The observed effect of co-exposure were often as pronounced as a dose up to ten times the individual environmental agent alone.
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Medikų,dirbančių su onkologiniais ligoniais, darbo sąlygų ir nusiskundimų sveikata sasajos / The relationship between health complaints and working conditions of doctors working with oncological patientsBrazienė, Jolanta 16 June 2008 (has links)
Darbo tikslas: Įvertinti medikų nusiskundimų savo sveikata sąsajas su darbo sąlygomis.
Darbo uždaviniai:
1. Ištirti medikų savo sveikatos vertinimą.
2. Įvertinti darbuotojų nuomonę apie darbo aplinkos rizikos veiksnius KMUK filialo Onkologijos ligoninėje.
3. Ištirti darbo sąlygų sąsajas su medikų nusiskundimais savo sveikatos būkle.
4. Pateikti rekomendacijas medikų sveikatos saugai KMUK filialo Onkologijos ligoninėje.
Tyrimo metodika. Buvo atliktas vienmomentis paplitimo tyrimas. Anoniminės anketinės apklausos pagalba 2008m. vasario mėn. buvo apklausti KMUK filialo Onkologijos ligoninės medicinos darbuotojai. Buvo išdalinta 350 anoniminių anketų, atsako dažnis 71.4 proc. (n=250). Duomenys buvo apdorojami ir analizuojami naudojant statistinių duomenų analizės paketą SPSS for Windows 13.0.
Rezultatai. Apklausta 227 moterys (90,8 proc.) ir 23 vyrai (9,2 proc.). Amžiaus vidurkis metais 42,8 ± 0,2: moterų - 42,6 ± 0,2, vyrų 44,1 ± 0,6. Dažniausiai ligoninės dirbantieji savo sveikatą vertino gerai (47,6 proc.) ir patenkinamai (42,8 proc.). Su stresinėmis situacijomis darbe susiduria 146 (18,0 proc.) darbuotojai. Daugiausia apklaustųjų 156 (19,2 proc.) nurodė, kad darbo aplinka užteršta cheminėmis medžiagomis. Daugiausiai jonizuojančios spinduliuotės poveikyje dirbo slaugytojos padėjėjos (26,7 proc.) (p=0,044). Su dezinfekcinėmis medžiagomis daugiausiai susiduria slaugytojos - 117, slaugytojos padėjėjos - 72, gydytojai – 22 ( proc.) ir 6 (proc.) laborantai. Kuo ilgiau darbuotojai... [toliau žr. visą tekstą] / Aim of the study: to evaluate the relationships between health complaints and work conditions among medical staff.
Goals of the study:
1. to analyse subjective health assessment of medical staff;
2. to estimate personnel opinion work-related risk factors at Oncology Hospital;
3. to establish relationships between work conditions and health complaints among medical staff;
4. to set recommendations for health safety of medical staff at Oncology Hospital.
Material and methods. The study design was cross-sectional prevalence study. Anonymous questionnaires were set for medical staff at Oncology Hospital (division of Kaunas University Hospital) in February 2008. Altogether 350 questionnaires were distributed, response rate 71.4% (n=250). Statistical data analysis was performed using statistical package „SPSS for Windows 13.0“.
Results. Among responders there were 227 women (90.8%) and 23 men (9.2%). The average age was 42.8±0.2 (42.6±0.2 for women and 44.1±0.6 for men). Majority of medical workers evaluated own health as good (47.6%) or satisfactory (42.8%). Work under stress was actual for 146 of responders (18.0%). Pollution with chemical substances in working environment was prevalent in 156 cases (19.2%). Ionized radiation mostly affected assistant nurses (26.7%; p=0.044). Disinfection substances mostly affected nurses (n=117), nurse assistants (n=72), physicians (n=22), and laboratory workers (n=6). Workers affiliated with this workplace longer also relate more health changes... [to full text]
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Μελέτη και πειραματικές μετρήσεις μοντέλων ηλεκτρομαγνητικής διάδοσης σε συστήματα ασύρματης επικοινωνίαςΜανιάτη, Ιωάννα 20 September 2010 (has links)
Η ερευνητική εργασία που ακολουθεί, έχει σαν στόχο, σε πρώτο επίπεδο, να μελετήσει τα διάφορα μοντέλα ηλεκτρομαγνητικής διάδοσης και σε δεύτερο πλάνο, να δωθεί μία εικόνα σχετικά με τις επιπτώσεις της μη ιονίζουσας ακτινοβολίας, που εκπέμπεται από κεραίες και ασύρματα δίκτυα, στον άνθρωπο και στον περιβάλλοντα χώρο.
Στα πρώτα κεφάλαια γίνεται μία θεωρητική αναφορά στις βασικές έννοιες της ηλεκτρομαγνητικής ακτινοβολίας και στους μηχανισμούς διάδοσης της, αλλά και στις επιπτώσεις της ακτινοβολίας αυτής στον άνθρωπο. Ακολουθεί, εκτενής παρουσίαση των πιο σημαντικών θεωρητικών μοντέλων διάδοσης ραδιοσήματος εξωτερικών και εσωτερικών χώρων αντίστοιχα.
Στη συνέχεια, δίνεται λεπτομερής περιγραφή των πεδιομέτρων που χρησιμοποιήθηκαν για την καταγραφή των μετρήσεων σε διάφορες περιοχές ενδιαφέροντος.
Στο τελευταίο κεφάλαιο, γίνεται παρουσίαση των μετρήσεων με συγκριτικά διαγράμματα καθώς και αναφορά για το κατά πόσο οι μετρήσεις βρίσκονται εντός των ορίων ασφαλείας που τίθενται από διεθνείς οργανισμούς. / In the present work, were studied the models of the radio signal distribution at open and close area and the consequences of the non-ionized radiation, which emits from a wide variety of wirelesses systems, on human body.
Initially, the basic significances of the electromagnetic radiation, the Maxwell’s equations and the mechanics of RF distribution, were shortly presented. Further emphasis at the models of the radio signal distribution, at open and close area, was given. The consequences of the electromagnetic radiation concerning basic factors of thermal and no-thermal effect were presented. An additional report of the RF safety limits, according to various international organizations, was given.
For the experimental process, we used the Narda Broadband Field meter, which recorded all the frequencies of the electromagnetic spectrum and a laptop with a suitable software (NETSTUMBLER 0.40), which allows the operator of the laptop to know the exact received power coming from the specific router of the WLAN, excluding all other signals even if they belong to the same frequency of 2.4 GHz.
The comparison of the experimental measurements with the theoretical, reveals the potential of each theoretical model. Furthermore, we came to the conclusion that the experiments are in the limits of RF safety.
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