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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
861

The toxicological evaluation of sewage effluents and pharmaceuticals with the use of zebrafish as a model organism /

Akande, Motunrayo Ganiyat, January 2008 (has links) (PDF)
Thesis (M.Sc.) Uppsala : Sveriges lantbruksuniv.
862

Binding of metals to macromolecular organic acids in natural waters : does organic matter? /

van Schaik, Joris W. J., January 2008 (has links) (PDF)
Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv. / Härtill 4 uppsatser.
863

Studies of polycyclic aromatic hydrocarbons in Dungeness crabs : biomonitoring, physiologically based toxicokinetic model, and human health risk assessment /

Eickhoff, Curtis Van. January 1900 (has links)
Thesis (Ph.D.) - Simon Fraser University, 2004. / Theses (Dept. of Biological Sciences) / Simon Fraser University.
864

Microbial transformation of arsenic and the characterization of Clostridium sp. strain OhILAs

Fisher, Edward. January 2006 (has links)
Thesis (M.S.)--Duquesne University, 2006. / Title from document title page. Abstract included in electronic submission form. Includes bibliographical references (p. v-xi) and index.
865

Εκτίμηση της οικολογικής ποιότητας των απορροών από διαφορετικές μεθόδους επεξεργασίας των ελαιουργικών αποβλήτων

Ρούβαλη, Αγγελική 08 February 2010 (has links)
Η Ελλάδα αποτελεί μία από τις βασικές ελαιοπαραγωγικές χώρες, καλύπτοντας το 17% της παγκόσμιας παραγωγής. Η παραγωγική διαδικασία λαμβάνει χώρα σε ελαιοτριβεία φυγοκεντρικού τύπου τριών φάσεων και δύο φάσεων. Στην πρώτη περίπτωση, παράγονται τρεις εκροές, το ελαιόλαδο, το υγρό απόβλητο και η παχύρευστη ελαιοπυρήνα. Στη δεύτερη περίπτωση, εκτός από το ελαιόλαδο προκύπτει και ένα παχύρευστο παραπροϊόν, η υγρή ελαιοπυρήνα. Τα παραπροϊόντα της ελαιοπαραγωγικής διαδικασίας, λόγω της απευθείας διάθεσης στο έδαφος ή στα ποτάμια ή στη θάλασσα, επιδρούν δυσμενώς και στο περιβάλλον λόγω του υψηλού οργανικού φορτίου και της τοξικής δράσης ορισμένων συστατικών τους. Για το λόγο αυτό υπάρχουν πολυάριθμες βιβλιογραφικές αναφορές σχετικές με μεθόδους επεξεργασίας του αποβλήτου, που αφορούν σε φυσικές, χημικές, βιολογικές μεθόδους, με τις τελευταίες να είναι πιο διαδεδομένες και να θεωρούνται πιο αποτελεσματικές. Η παρούσα μελέτη στοχεύει στην εκτίμηση του κινδύνου του ελαιουργικού αποβλήτου για το υδάτινο οικοσύστημα και της αποτελεσματικότητας τριών βιολογικών μεθόδων επεξεργασίας του, ως προς τη μείωση της τοξικότητας, με σκοπό την ασφαλή διάθεση στο περιβάλλον. Πραγματοποιήθηκαν μετρήσεις των φυσικοχημικών παραμέτρων των απορροών που προέκυψαν από την επεξεργασία του αποβλήτου με τον μύκητα Pleurotus ostreatus, καθώς και από την αναερόβια επεξεργασία σε αντιδραστήρες για παραγωγή υδρογόνου και μεθανίου. Η αποτελεσματικότητα των μεθόδων ελέγχθηκε μέσω της οικοτοξικολογικής προσέγγισης με τη χρήση των μικροβιοτεστ Thamnotoxkit F και Daphtoxkit FTM pulex και του τεστ τοξικότητας με έμβρυα ιχθύος (Danio rerio). Θα πρέπει να επισημανθεί ότι ανάλογη ολοκληρωμένη μελέτη τοξικότητας των αποβλήτων των ελαιουργείων δεν έχει γίνει στη χώρα μας, γεγονός που καθιστά την όλη προσπάθεια ιδιαίτερα ενδιαφέρουσα. Λήφθηκαν 7 δείγματα ανεπεξέργαστου ελαιουργικού αποβλήτου, 16 δείγματα από την επεξεργασία με P. ostreatus, 50 δείγματα από τον αναερόβιο αντιδραστήρα για παραγωγή υδρογόνου και 25 από τον αντιδραστήρα για παραγωγή μεθανίου. Η επίπτωση του ελαιουργικού αποβλήτου στα υδάτινα οικοσυστήματα και συγκεκριμένα σε ποτάμι, πραγματοποιήθηκε με την εφαρμογή της μεθοδολογίας για την εκτίμηση κινδύνου, μέσω του λόγου RQ (Risk Quotient) από όπου προέκυψε ότι ο κίνδυνος είναι ιδιαίτερα υψηλός. Η φυσικοχημική ανάλυση των δειγμάτων έδειξε υψηλές τιμές στις παραμέτρους που αναλύθηκαν, ακόμα και μετά την επεξεργασία, καθώς και μεγάλη διακύμανση αυτών σε δείγματα της ίδιας κατηγορίας. Από τους ελέγχους τοξικότητας που εφαρμόστηκαν, υπολογίσθηκαν οι τιμές τοξικότητας LC50 και εν συνεχεία οι τοξικές μονάδες (ΤU). Μέσω αυτών, το ελαιουργικό απόβλητο κατατάσσεται στην κατηγορία «πολύ τοξικό» (D. pulex) και «εξαιρετικά τοξικό» (Τ. platyurus και D. rerio), με τιμές ΤU να κυμαίνονται από 60,2 – 330,9. Η τοξικότητα συνδέεται άμεσα με τις φαινόλες, τα νιτρώδη, τα αμμωνιακά, τις τανίνες, τα θειικά ιόντα, τα ολικά χλωριόντα και τα ολικά διαλυμένα στερεά. Η απορροή της πρώτης μεθόδου επεξεργασίας (με P. ostreatus), είχε μειωμένες συγκεντρώσεις φαινολικών και τανίνων και υψηλές εκείνες των υπόλοιπων παραμέτρων. Σύμφωνα με τους ελέγχους τοξικότητας με Daphtoxkit pulex και Thamnotoxkit, αυτή συσχετίζεται με τα αμμωνιακά, τις φαινόλες και τα ολικά διαλυμένα στερεά, ενώ στα zebrafish δεν εμφάνισαν συσχέτιση. Η απορροή χαρακτηρίστηκε «πολύ τοξική» (TU = 52,4 – 91,5). Στην αναερόβια επεξεργασία για παραγωγή υδρογόνου χρησιμοποιήθηκαν δύο τύποι αποβλήτου: υγρό απόβλητο από ελαιοτριβείο τριών φάσεων και ελαιοπολτός από ελαιοτριβείο δύο φάσεων. Οι έλεγχοι τοξικότητας με τα καρκινοειδή χαρακτήρισαν και τους δύο τύπους απορροών «πολύ τοξικές» (TU = 26,8 – 68,7) ενώ με το zebrafish το υγρό απόβλητο κρίθηκε «εξαιρετικά τοξικό» (TU = 132,2) και ο ελαιοπολτός «πολύ τοξικός» (TU = 73,5). Η D. pulex επηρεάστηκε από τα ιόντα NO-3, NO-2 , SO-24 , Cl- και το COD του υγρού αποβλήτου, ενώ υπήρξε συσχέτιση με όλους τους παράγοντες του ελαιοπολτού εκτός του COD. Οι τιμές του COD συσχετίστηκαν με τις τιμές τοξικότητας του Thamnotoxkit και στους δύο τύπους απορροών, ενώ το zebrafish εμφάνισε ευαισθησία έναντι των νιτρωδών, νιτρικών, αμμωνιακών και χλωριόντων του υγρού αποβλήτου και μόνο στις συγκεντρώσεις των φαινολικών του ελαιοπολτού. Κατά την αναερόβια επεξεργασία για παραγωγή μεθανίου οι έλεγχοι τοξικότητας κατέταξαν την απορροή στην κατηγορία «πολύ τοξική» (TU = 23,9 – 45,5). Οι τιμές τοξικότητας του Daphtoxkit συσχετίστηκαν με τα νιτρικά, τα αμμωνιακά, το pH και την αγωγιμότητα, ενώ οι τιμές που προέκυψαν από το Thamnotoxkit επηρεάστηκαν από τις φαινόλες, τις τανίνες και τις λιγνίνες. Και σε αυτή την περίπτωση, το zebrafish, δεν φάνηκε να επηρεάζεται από τις παραμέτρους που αναλύθηκαν. Σύμφωνα με τα αποτελέσματα των ελέγχων με zebrafish, που ήταν το πιο ευαίσθητο είδος, η τοξικότητα της απορροής μειώθηκε σε σχέση με το ανεπεξέργαστο απόβλητο κατά 60% στην επεξεργασία με μύκητα, 65% στην αναερόβια χώνευση για παραγωγή υδρογόνου και 86% στην αναερόβια χώνευση για παραγωγή μεθανίου. Ωστόσο η εκροή παραμένει στη «πολύ τοξική» κατηγορία ώστε να μην θεωρείται ασφαλής για διάθεση στο περιβάλλον. Παράλληλα, πραγματοποιήθηκε ανίχνευση μικροβιακών πληθυσμών στο ελαιουργικό απόβλητο και στο αναερόβια επεξεργασμένο για παραγωγή υδρογόνου. Ανιχνεύτηκαν τόσο οργανισμοί που αποδομούν τις φαινολικές ενώσεις (Pseudomonas aeruginosa) όσο και παθογόνοι (Citrobacter, Enterobacter clocae, Aeromonas hydrophila, Pseudomonas sp.), οι οποίοι εμφάνισαν συσχέτιση με τα αποτελέσματα των ελέγχων τοξικότητας με zebrafish, ερμηνεύοντας σε κάποιο βαθμό την ευαισθησία του είδους. Εμφανίστηκαν διαφορές μεταξύ των μικροβιακών πληθυσμών στους δύο τύπους αποβλήτου, με μόνο κοινό είδος το Enterobacter clocae. Τέλος, με τη χρήση της ατομικής απορρόφησης ανιχνεύτηκαν βαρέα μέταλλα, τα οποία θεωρείται ότι προκάλεσαν τις παρατηρηθείσες δυσμορφίες στα έμβρυα του zebrafish μετά από έκθεση 7 ημερών, όπως έλλειψη χρώσης και σκελετικές δυσμορφίες. Οι μέσοι όροι των συγκεντρώσεων των βαρέων μετάλλων στα δείγματα κυμάνθηκαν μεταξύ 3,645 – 6,074 μg Hg/l, 0,488 – 1,017 mg Cu/l, 0,137 – 0,712 mg Mn/l, 0,190 – 3,198 mg Zn/l, 0,205 – 0,505 mg Cr/l, μη ανιχνεύσιμο - 0,106 mg Cd/l και 0,135 – 0,271 mg Pb/l. Συμπεραίνεται ότι η τοξικότητα των απορροών προκαλείται από συνδυασμό παραμέτρων, μεταξύ των οποίων περιλαμβάνονται οι φαινόλες, οι τανίνες, τα αμμωνιακά, τα νιτρικά και τα νιτρώδη. Εκτός αυτών όμως, εκτιμάται ότι συνεισφέρουν στην τοξικότητα και οι μικροβιακοί πληθυσμοί αλλά και τα βαρέα μέταλλα. Οι αναφερθείσες μέθοδοι επεξεργασίας αποδεικνύονται ιδιαίτερα αποτελεσματικές στη μείωση της τοξικότητας του ελαιουργικού αποβλήτου, με τη μέθοδο της αναερόβιας χώνευσης για παραγωγή μεθανίου να αναδεικνύεται η πιο αποτελεσματική. Ωστόσο η μείωση αυτή δεν είναι αρκετή για να καταστήσει την εκροή ασφαλή για απόρριψη σε υδάτινα οικοσυστήματα. Τέλος, η παρούσα μελέτη προσφέρει νέα δεδομένα που μπορούν να χρησιμοποιηθούν από την επιστημονική κοινότητα για την αναζήτηση και ανάπτυξη περιβαλλοντικά φιλικότερων μεθόδων επεξεργασίας των συγκεκριμένων αποβλήτων, αλλά και εργαλεία στους αρμόδιους θεσμικούς φορείς για τη συστηματική παρακολούθηση και τον έλεγχο των επιπτώσεων σύνθετων αποβλήτων στο περιβάλλον. / Greece is one of the major olive oil producing countries, covering 17% of the worldwide production. In the recent years, the productive process takes place in centrifugal type olive oil mills of three phases and two phases. In the first case, three outflows are produced, the olive oil, the liquid wastewaters and oil-stone. In the second case, apart from olive oil, the by-product is a semi-solid waste called olive pulp. The by-products of the olive oil process provoke serious repercussions to the environment from the uncontrolled disposal to the soil and to the rivers or to the sea, because of the high organic load and the especially toxic action of certain components. For this reason many bibliographic reports exist regarding treatment methods of this waste, which include physical, chemical and biological methods, with the last to be considered more effective. The present study aims to the risk assessment of olive oil mill wastewaters (OMW) posed to aquatic ecosystems and to the estimation of the effectiveness of three biological treatment methods regarding the reduction of toxicity, driving to safe environmental disposal. Analyses of the physicochemical characteristics were conducted for the effluents that resulted from the treatment of the waste with the white rot fungus Pleurotus ostreatus, as well as from the anaerobic treatment in reactors for hydrogen and methane production. The effectiveness of the aforementioned methods was validated via the ecotoxicological approach with the use of the two microbiotests Thamnotoxkit F and Daphtoxkit FTM pulex and the embryo toxicity test of the zebrafish Danio rerio. It must be noted that a similar integrated study has not been conducted not only in Greece but worldwide, a fact rendering the whole effort especially interesting. Seven (7) samples of the untreated OMW were collected from a three phase system, 16 samples from the outflow of the treatment with P. ostreatus, 50 samples from the anaerobic reactor for hydrogen production and 25 samples from the methane producing reactor. The repercussion of OMW to the aquatic ecosystems and specifically to a river, was realised with the application of the risk assessment methodology, via the Risk Quotient (RQ). The results indicate that the risk is quite high seasonally. The physicochemical analyses of the samples revealed high values in the parameters that were analyzed, even after the treatments, as well as a high deviation of the values, even in samples of the same category. The toxicity test results were expressed in LC50 values according to the test protocols that were transformed to toxic units (TU), in order to categorize the samples. The untreated samples were classified in the category “very toxic” (against D. pulex) and “extremely toxic” (against T. platyurus and D. rerio), with TU values that oscillated from 60,2 - 330,9. The toxicity appears to be influenced considerably by phenols but also by nitrates, ammonium, tannins, the sulphuric ions, total chlorine and total dissolved solids. The first treatment method (with P. ostreatus), resulted in an effluent with decreased concentrations of phenols and tannins, but the remaining toxic parameters had high values. The results of the toxicity tests with Daphtoxkit pulex and Thamnotoxkit were correlated with ammonium, phenols and total dissolved solids, while zebrafish were not cross-correlated. The outflow was characterized as “very toxic”, while the TU oscilated from 52,4 - 91,5. In the anaerobic treatment for hydrogen production two types of wastes were used: liquid wastewaters and olive pulp from a three phase and two phase olive oil mill respectivelly. Toxicity tests with the crustaceans characterized the two types of outflows as “very toxic” (TU = 26,8 - 68,7) while according to the zebrafish test only the liquid wastewater was assessed as “exceptionally toxic” (TU = 132,2) whereas the olive pulp as “very toxic” (TU = 73,5). D. pulex was influenced by ions such as NO-3, NO-2 , SO-24 , Cl- and COD from the treated OMW, whereas all parameters from the olive pulp revealed good correlation to D. pulex with the exception of COD. The results from the Thamnotoxkit test correlated with COD in both types of effluents, while zebrafish presented a sensitivity against the concentrations of nitrates, nitrites, ammonium and chlorine. In the case of anaerobic treatment for the production of methane the toxicity tests classified the outflow in the category “very toxic” (TU = 23,9 - 45,5). The toxicity values of Daphtoxkit were correlated with nitrites, ammonium, pH and conductivity, while the values that resulted from Thamnotoxkit were influenced by phenols, tannins and lignin. Also in this case, zebrafish, it did not appear to be influenced from the analyzed parameters. According to the results of the zebrafish tests that were the most sensitive, the toxicity of the treated effluents was decreased compared to that of the untreated wastewaters, by 60% in the treatment with the white rot fungi, 65% in the anaerobic reactor for hydrogen production and 86% in the anaerobic reactor for the production of methane. All outflows however remain in the “very toxic” category so they are not considered acceptable for environmental disposal. In addition to the above, microbial populations in the untreated OMW and in the effluent from the anaerobic processe for hydrogen production were detected. Organisms that degrade phenolic compounds were detected (Pseudomonas aeruginosa), as well as others that are considered as pathogens (Citrobacter sp., Enterobacter clocae, Aeromonas hydrophila, Pseudomonas sp.). The later presented cross-correlation with the results of the zebrafish toxicity tests, interpreting in some degree the sensitivity of the species. The microbial flora was differentiated between the untreated and treated effluent presenting only one common species, namely Enterobacter clocae. Finally, heavy metals were detected in all outflows, which are considered to cause malformations that were observed in this study in zebrafish embryos after a 7-day test. These included lack of pigmentation and spinal deformities. The mean values oscillated between 3,645 - 6,074 μg Hg/l, 0,488 - 1,017 mg Cu/l, 0,137 - 0,712 mg Mn/l, 0,190 - 3,198 mg Zn/l, 0,205 - 0,505 mg Cr/l, not detected- 0,106 mg Cd/l and 0,135 - 0,271 mg Pb/l. In conclusion, the toxicity of the analyzed samples was caused by a combination of parameters, which included phenols, tannins, ammonium, nitrites and nitrates. However, besides these, the microbial populations but also the heavy metals that were detected probably contribute to the observed toxicity. The particular treatment methods proved to be especially effective in the reduction of toxicity of olive oil mill wastewaters, but the reduction is not capable to render the outflow as safe for disposal in aquatic ecosystems. Finally, the current study offers data that could be utilized by the relative scientists in order to develop more environmentally friendly methods for the treatment of this specific effluents and additionally provides tools to the government officials for the systematic monitoring and controlling of such complex and hazardous effluents.
866

Απόβλητα ελαιοτριβείου και βιολογικές επιπτώσεις τους σε ιστούς του κοινού μυδιού Mytilus galloprovincialis

Δανελλάκης, Δημήτριος 10 June 2013 (has links)
Στην παρούσα μελέτη διερευνώνται οι πιθανές επιπτώσεις των αποβλήτων που προέρχονται από ελαιοτριβεία τριών φάσεων σε ιστούς του μυδιού Mytilus galloprovincialis. Άτομα που εκτέθηκαν για 5 ημέρες σε διαφορετικές αραιώσεις/συγκεντρώσεις του αποβλήτου παρουσίασαν μεγάλη θνησιμότητα σε αραιώσεις 1/1000 και 1/500, ενώ έκθεση των μυδιών σε μεγαλύτερες αραιώσεις του αποβλήτου (1/1000 και 1/10000), έδειξε μικρότερη θνησιμότητα. Οι υπο-θανατογόνες συγκεντρώσεις του αποβλήτου χρησιμοποιήθηκαν για την εκτίμηση α) της σταθερότητας των λυσοσωμικών μεμβρανών σε αιμοκύτταρα της αιμολέμφου (lysosomal membrane stability/LMS), β) της συχνότητας εμφάνισης μικροπυρήνων (micronuclei frequency/MN) και κυτταρικών ανωμαλιών σε αιμοκύτταρα, γ) της δραστικότητας της ακετυλ-χολινεστεράσης (AChE) στην αιμόλεμφο και τα βράγχια των εκτιθέμενων ατόμων, καθώς και ε) την εκτίμηση των επιπέδων των μεταλλοθειονινών (ΜΤ) στα βράγχια. Σύμφωνα με τα αποτελέσματα, άτομα που εκτέθηκαν σε αραιώσεις 1/1000 και 1/1000 του αποβλήτου, εμφάνισαν σημαντική μείωση του χρόνου αποσταθεροποίησης των λυσοσωμικών μεμβρανών των αιμοκυττάρων τους, με ταυτόχρονη αύξηση της συχνότητας εμφάνισης μικροπυρήνων και κυτταρικών ανωμαλιών. Επιπλέον, σημαντική μείωση της δραστικότητας της AChE παρατηρήθηκε σε όλους τους ιστούς (αιμόλεμφος και βράγχια), σε σχέση με τα αντίστοιχα επίπεδα δραστικότητας που μετρήθηκαν στους ιστούς ατόμων που δεν εκτέθηκαν στο απόβλητο, ενώ σημαντική αύξηση των επιπέδων ΜΤ παρατηρήθηκαν στα βράγχια των εκτιθέμενων ατόμων. Σύμφωνα με τα αποτελέσματα, το υψηλό οργανικό φορτίο, η μεγάλη συγκέντρωση φαινολών, καθώς και η ύπαρξη μεταλλικών στοιχείων μπορεί να ευθύνονται για την πρόκληση των επιβλαβών επιπτώσεων του αποβλήτου σε υδρόβιους οργανισμούς, όπως τα Δίθυρα μαλάκια, προκαλώντας σημαντικές βλάβες τόσο σε κυτταρικό όσο και σε μοριακό επίπεδο. / The present study investigates the biological effects of olive oil mill wastewaters (OMW) on tissues of mussels Mytilus galloprovincialis. Mussels exposed to different quantities of OMW (dilution factors 1/100 and 1/500) for 5 days showed increased levels of mortality, while mussels’ mortality observed after exposure to lower quantities of the OMW (dilution factors 1/1000 and 1/1000) was negligible. According to the latter, prepathological alterations occurred in tissues of mussels exposed to sub-lethal concentrations of OMW were further investigated with the use of stress-indices, such as lysosomal membrane stability (via the neutral red retention time assay/NRRT), acetylcholinesterase (AChE) activity, metallothionein (MT) content and micronuclei frequency (MN). According to the results of the present study, decreased NRR time values and significantly elevated levels of MN and nuclear abnormalities were observed in haemocytes of exposed mussels in each case. Moreover, mussels exposed to either 1/1000 or 1/10000 diluted OMW showed significantly decreased levels of AChE activity in haemolymph and gills, as well as increased MT levels in gills, compared with levels measured in the respective tissues of control mussels. The results of the present study indicates that biological effects of OMW could be due to the high organic loading toxicity of OMW, its high levels of phenolic compounds, as well as the presence of metallic anions, thus giving rise to the hypothesis that short-time exposure of marine organism to OMW could resulted in the induction of severe cytotoxic and genotoxic damage.
867

Avaliação da toxicidade reprodutiva da sinvastatina em Ratos machos adultos

Banzato, Thais Petrochelli [UNESP] 17 May 2013 (has links) (PDF)
Made available in DSpace on 2014-08-13T14:50:38Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-05-17Bitstream added on 2014-08-13T18:01:35Z : No. of bitstreams: 1 000743622.pdf: 1640934 bytes, checksum: 02da6d91d5c5da0392b723a1d2003011 (MD5) / As estatinas são amplamente utilizadas no tratamento da hiperlipidemia e estão entre as drogas com maiores índices de vendas no mundo. Seu efeito se dá através da inibição competitiva da HMGCoA redutase, uma enzima limitante da síntese de colesterol que catalisa a conversão de HMG-CoA em mevalonato, interrompendo a cascata da síntese do colesterol e isoprenóides. Para os ensaios in vitro de reatividade farmacológica, ratos (n = 5) foram eutanaziados e epidídimo, canal deferente, e glândula seminal foram removidos. Após isso, os tecidos foram isolados e montados em câmaras musculares para o registro digital do desenvolvimento da tensão isométrica. Foi construída uma curva concentração- resposta à noradrenalina com a sinvastatina nas concentrações 3, 10, 30 e 100 μM. Não houve alterações na sensibilidade à noradrenalina nos ductos deferente e epididimário entre os grupos. Esses resultados estão relacionados com o não comprometimento da motilidade espermática e tempo de trânsito espermático pelo epidídimo em estudo realizado com animais expostos a 20 e 40 mg/Kg/dia de sinvastatina / Statins are lipid lowering agents extensively used in human clinical medical. They exert their effects through inhibition of HMG-CoA reductase, a crucial enzyme in cholesterol synthesis. Since cholesterol is the precursor of steroid hormones, drugs that decrease cholesterol may damage male reproductive function. Investigate the effects of the exposure to different doses of simvastatin on the reproductive parameters of adult male Wistar rats. Thirty rats were randomly assigned into three groups: simvastatin (20 or 40 mg/kg), control (vehicle - DMSO/oil), and were treated for 30 days orally for evaluation of reproductive parameters after euthanasia. Weight of the reproductive organs; sperm counts, motility and morphology; histopathology; hormonal levels and fertility. The weight of reproductive organs, sperm motility and histopathology analysis were similar among groups. There was a decrease in sperm production and epididymis sperm number, uterus weight with fetuses, implant and live fetuses numbers in simvastatin groups. The animals exposed to simvastatin showed an increase in the pre-implantation loss and sperm with abnormal morphology. The observed effects on reproductive parameters could be associated with toxic effects of simvastatin on spermatogenesis, causing potential damage to male fertility
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Avaliação da recalcitrância e toxicidade de lixiviado bruto e tratado por processos primário e secundário. / Evaluation of recalcitrance and toxicity of raw leachate and treated by primary and secondary processes.

Caroline Mitai Marques Pereira 10 April 2013 (has links)
Financiadora de Estudos e Projetos / Um dos grandes problemas enfrentados no tratamento de lixiviado é a definição de suas características físico-químicas e biológicas. Neste contexto, o objetivo do presente trabalho é avaliar a composição química, a recalcitrância, e a toxicidade do lixiviado bruto e tratado por processos de tratamento (físico-químico e biológico) oriundo do Aterro Metropolitano de Gramacho, localizado no município de Duque de Caxias, no estado do Rio de Janeiro. Os resultados mostraram maior biodegradabilidade aeróbia no efluente físico-químico com percentuais variando de 7% a 35 %. A natureza de tais compostos justifica a natureza refratária do lixiviado e alerta pela toxicidade que podem atribuir tanto aos microrganismos envolvidos no processo quanto a saúde humana quando dispostos incorretamente. Para o lixiviado em estudo, observou-se a diminuição da toxicidade ao passar pelo processo físicoquímico. Dessa maneira, observou-se que é necessário a adoção de sistemas de tratamento que conjuguem processos físico-químicos atuando como pré ou pós-tratamento de processos biológicos. Sendo assim, os resultados obtidos mostram a importância deste tipo de caracterização, como fonte de subsídios para a seleção, projeto e avaliação de sistemas de tratamento. / Leachate from Municipal Solid Waste are characterized by high concentration of refractory organic matter, ammonia and toxic compounds. In this context, the objective of this study is to evaluate the chemical composition, the recalcitrance and toxicity of raw and treated leachate for treatment processes (physical and biological) from the Gramacho Metropolitan Landfill, located in the municipality of Duque de Caxias, in the state of Rio de Janeiro. The results showed higher aerobic biodegradability in the effluent physicochemical with percentages ranging from 7% to 35%. The nature of some compounds justifies the refractory nature of the leachate and alert the toxicity that can assign both the microorganisms involved in the process as human health when disposed improperly. Thus, it was observed that it is necessary to adopt treatment systems that combine physical and chemical processes acting as a propost treatment of biological processes. Thus, the results show the importance of this type of characterization, as a source of information for the selection, design and evaluation of treatment systems.
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Parâmetros toxicológicos em carpas (Cyprinus carpio) expostos a uma formulação comercial de clomazone (gamit®) / Toxicological parameters in carp (Cyprinus carpio) exposed to a commercial formulation of clomazone (gamit®)

Cattaneo, Roberta 07 October 2011 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Commercial formulations of the herbicide clomazone have been widely used in agriculture and fish farming to control weeds. Fish can be affected when the water reaches the drainage waterways, causing an imbalance in the aquatic ecosystem. In order to evaluate a possible contamination, we determined LC50 (96h) using a commercial formulation containing clomazone (Gamit®). We verified the metabolic, enzymatic, and genotoxic parameters as well as the oxidative stress in juvenile carp (Cyprinus carpio). Firstly, in order to determine the LC50 for the acute toxicity test, , the animals were exposed to the concentrations of 10, 20, 30, 40 and 50 mg/L of clomazone for 96 h and the fish behavior was analyzed during this period. After exposure, we verified the activity of the enzyme acetylcholinesterase (AChE) in muscle and brain of the dead fish and the live carp. Secondly, fish were exposed to the herbicide for 7 days, both in field (rice crop) and laboratory conditions. The concentration used in the rice crop and the laboratory was 0.5 mg/L. After the experimental period of 7 days under laboratory conditions and 7, 30, and 90 days under rice crop conditions, brain, liver and muscle of fish were sampled to carry out the toxicological analysis. The parameters studied were enzymatic activity of AChE, catalase (CAT) and glutathione S-tranferase (GST) in different tissues of this species. Some markers of oxidative stress, such as protein carbonylation and thiobarbituric acid reactive substances (TBARS) levels in liver tissue were also analyzed. Some metabolic parameters such as glucose, glycogen, lactate, protein, and ammonia as well as amino acids in liver and muscle of carp were also measured. In plasma, we measured glucose, lactate, and protein. Thirdly, carp were exposed to approximately 15% of the LC50 (5.0 mg/L) for 7 days. We verified the formation of reactive oxygen species (ROS) and micronucleus, and the comet test was performed in order to investigate the presence of DNA damage. In the first study we observed that fish exposed to 20, 30, 40 and 50 mg/L showed behavioral changes and LC50 (96h) was 30.35 mg/L. In addition, it was found that the activity of the enzyme AChE showed no significant changes in the brain of the fish that died at the concentrations tested (30, 40 and 50 mg/L), and the muscle of dead fish had an increase in this enzyme when they were exposed to 50 mg/L of clomazone. The activity decreased significantly in the brain AChE of fish that remained alive after 96 h of exposure to 10, 20 and 30 mg/L, but increased in the muscle of the surviving fish exposed to all concentrations tested. In the second experiment results showed that fish exposed to 7 days had no changes in AChE under field conditions. However, a decrease in the activity of this enzyme in muscle was observed under laboratory conditions. During the same period of exposition, the parameters of oxidative stress conditions changed both under the field and in laboratory conditions. However, metabolic parameters were altered only under field conditions. After 30 and 90 days, AChE activity did not change under field conditions. Disturbances in oxidative stress parameters and metabolism in different tissues were evident in the tissues up to 90 days after treatment. The results showed that the activity of AChE changed only under laboratory conditions, and that oxidative stress associated with metabolic parameters can be good indicators of contamination for clomazone in C. Carpio in rice field conditions. In the third experiment, the results showed an increased formation of ROS and a significant micronucleus (MN) and DNA damage in erythrocytes after exposure to 5.0 mg/L of the herbicide clomazone. Given these results, we can conclude that the herbicide studied can be dangerous to Cyprinus carpio when exposed to it due to increased ROS, which in turn cause oxidative stress evidenced by changes in enzyme markers, metabolic, genotoxic and oxidative stress. However, further studies are needed in order to verify the safety of this herbicide is when associating rice and fish. / As formulações comerciais do herbicida clomazone têm sido amplamente utilizadas na agricultura e na piscicultura para controle de plantas daninhas. Os peixes podem ser afetados quando as águas de drenagem atingem os cursos d água, acarretando um desequilíbrio no ecossistema aquático. Para avaliar uma possível contaminação foi determinada a CL50 (96h) utilizando-se uma formulação comercial contendo clomazone (Gamit®) verficando-se parâmetros metabólicos, enzimáticos, genotóxicos e de estresse oxidativo em juvenis de carpas (Cyprinus carpio). Para o teste de toxicidade aguda, a fim de determinar a CL50, os peixes foram expostos às concentrações 10, 20, 30, 40 e 50 mg/L de clomazone em água durante 96 horas e o comportamento dos peixes foi analisado nesse período. Após a exposição, foi verificada a atividade da enzima acetilcolinesterase (AChE) no cérebro e músculo dos peixes mortos e das carpas que sobreviveram. No segundo experimento, os peixes foram expostos ao herbicida durante sete dias, tanto em condição de campo (lavoura de arroz irrigado) como de laboratório. A concentração utilizada na lavoura de arroz e no laboratório foi de 0,5 mg/L. Decorridos os períodos experimentais de 7 dias em condições de laboratório, e 7, 30 e 90 dias em condições de lavoura de arroz, foram retirados o cérebro, o fígado e o músculo dos peixes para realização das análises toxicológicas. Os parâmetros enzimáticos analisados foram a atividade da AChE, catalase (CAT) e glutationa S-transferase (GST). Também foram analisados alguns marcadores de estresse oxidativo, como a carbonilação de proteínas e níveis das substâncias reativas ao ácido tiobarbitúrico (TBARS) no tecido hepático. Por fim, foram avaliados alguns parâmetros metabólicos como: glicose, glicogênio, lactato, proteína, amônia e os aminoácidos em fígado e em músculo de carpas. No plasma, foram feitas as dosagens de glicose, de lactato e de proteína. Em um terceiro experimento, as carpas foram expostas a aproximadamente 15% do valor obtido para a CL50 (5,0mg/L) por 7 dias. Posteriormente, foi verificada a formação das espécies reativas de oxigênio (EROs) e foram realizados os testes do micronúcleo e cometa (expresso por índice de dano do DNA). No primeiro experimento, foi observado que os peixes expostos a 20, 30, 40 e 50 mg/L, mostraram mudanças comportamentais e a CL50 (96h) foi 30,35 mg/L. Além disso, foi verificado que a atividade da enzima AChE não apresentou alterações significativas no cérebro dos peixes que morreram nas concentrações testadas (30, 40 e 50mg/L), e no músculo dos peixes mortos houve uma elevação na atividade desta enzima, quando eles foram expostos a 50 mg/L de clomazone. Já a atividade AChE diminuiu significativamente no cérebro dos peixes que sobreviveram após 96h de exposição a 10, 20 e 30mg/L, no entanto, aumentou no músculo dos peixes sobreviventes expostos a todas as concentrações testadas. No segundo experimento, os resultados mostraram que os peixes expostos a 7 dias não apresentaram alterações na AChE em condições de campo. No entanto, uma diminuição da atividade desta enzima no músculo foi observada em condições de laboratório. Durante o mesmo período de exposição, os parâmetros de estresse oxidativo mudaram tanto em condições de campo quanto em laboratório. Entretanto, os parâmetros metabólicos foram alterados apenas em condições de campo. Após 30 e 90 dias, a atividade da AChE não se alterou em condições de campo. Distúrbios nos parâmetros de estresse oxidativo e metabolismo foram evidentes nos tecidos até 90 dias após a aplicação. Os resultados mostraram que a atividade da AChE alterou apenas em condições de laboratório, e que marcadores de estresse oxidativo associados aos parâmetros metabólicos podem ser bons indicadores de contaminação para o clomazone em C. carpio em condições de campo. No terceiro experimento, os resultados mostraram um aumento da formação das EROs e significativo aumento dos MN e de danos no DNA dos eritrócitos após a exposição a 5,0 mg/L do herbicida clomazone. De acordo com os resultados obtidos, conclui-se que o herbicida estudado pode ser perigoso para as carpas quando expostas, devido ao aumento das EROs que por sua vez causam estresse oxidativo, evidenciado por alterações em marcadores enzimáticos, metabólicos, genotóxicos e de estresse oxidativo. Contudo, mais estudos serão necessários para verificar a segurança desse herbicida para os cultivos associados utilizando-se arroz e peixes.
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Respostas bioquímicas e fisiológicas de Cucumis sativus e Avena sativa ao estresse causado por alumínio / Biochemical and physiological responses of Cucumis sativus and Avena sativa to excess aluminum stress

Pereira, Luciane Belmonte 21 May 2010 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Aluminum (Al) is the most abundant metal in the Earth's crust, affecting growth and development of plants. The aim of this study was to investigate the effects of Al on seedlings of cucumber (Cucumis sativus L.) and oat (Avena sativa L) through the analysis of biochemical and physiological parameters. Three different genotypes of oat seedlings were studied, namely UFRGS 930598 Al-sensitive, UFRGS 17 Altolerant, and 280 Al-intermediate (resulting from the crossing UFRGS 930598 and UFRGS 17), exposed to 0, 5, 10, 20, and 30 mg/L Al. The biochemical parameters analyzed for cucumber were: the activity of antioxidant enzymes (catalase (CAT), ascorbate peroxidase (APX) and superoxide dismutase (SOD)), the levels of lipid peroxidation, leakage electrolytes, protein oxidation, and chlorophyll content. The increase of electrolyte leakage and the production of hydrogen peroxide observed are related to the decreased efficiency of the antioxidant system at the highest concentrations of Al. The antioxidant system was unable to prevent the toxicity resulting in negative effects such as lipid peroxidation, protein oxidation, and decreased plant growth. Oat seedlings were exposed to Al in different growth media. The first exposure was in the midst of semi-solid growth agar for 5 days, seedlings with five days of development and then to a hydroponic solution for 7 days with 10 days of seedling development. The content of hydrogen peroxide, lipid peroxidation, ascorbic acid and non-protein thiols (NPSH), as well as the activity of the enzymes CAT, APX and SOD, and the content of Al accumulated in the seedlings were evaluated. Enzymes activities of the antioxidant SOD and CAT were increased in UFRGS 17 and UFRGS 280 genotypes. Even when these two genotypes accumulated high concentrations of Al, they did not show high levels of lipid peroxidation and contents of hydrogen peroxide when compared with the 930598 genotype. For this genotype, an activation of the enzyme APX was observed, however, high levels of Al accumulated in the plant caused an increase in the lipid peroxidation and hydrogen peroxide content. The UFRGS 930598 genotype was more sensitive to Al than the UFRGS 17 and UFRGS 280 genotypes, which confirms the previous morphological analysis obtained by FEDERIZZI et al., 2000. Although there was increased activity of APX in this genotype, the antioxidant system was not efficient in the removal of reactive oxygen species (ROS). In order to better understand these results, a growth medium with a hydroponic solution was used in which the mobility of the metal was greater for an exposure period of 7 days with oat seedlings with 10 days of development. Besides the biochemical parameters mentioned above, the analysis of the growth of roots and shoots, fresh and dry matter, chlorophyll content, activity of the enzyme δ -aminolevulinic acid dehydratase (δ -ALA -D), and the monitoring of the pH of the hydroponic solution of each genotype were performed. The pH of the hydroponic solution of salt-tolerant genotype (UFRGS 17) showed a significant increase in pH, while the sensitive (UFRGS 930598) and intermediate (UFRGS 280) genotypes showed no significant changes. The sensitive genotype presented inhibition of root and shoot growth at the highest concentrations of Al while the tolerant and intermediate genotype showed no significant changes. The activity of antioxidant enzymes was increased after 7 days of exposure to Al in the sensitive genotype, whereas in the tolerant genotype there was no increase in this activity. In seedlings of the intermediate genotype there was an increase in the activity of CAT, APX and SOD enzymes only at higher Al concentrations (20 and 30 mg/L). Results showed that the intermediate and tolerant genotypes showed similar effects not only on the activity of enzymes of the antioxidant system, but also on the physiological parameters such as growth of roots and shoots. Even when accumulating high concentrations of Al, the intermediate genotype did not show a decrease in growth, which shows that it has resistance mechanisms related to the internal immobilization of this metal in the vacuoles. The tolerant genotype also introduces mechanisms of resistance to Al, but these mechanisms may be the exclusion of Al by binding this metal to organic acids. In order to investigate if the antioxidant system is activated in different genotypes of oat, seedlings were placed in growth medium with a hydroponic solution and withdrawn from the medium after 12, 24, and 36 h of exposure to 20 mg/L. Tolerant and intermediate genotypes showed an increase of the enzyme activity of the antioxidant system after 12 h of exposure to Al, while the sensitive genotype presented this increase only after 24 or 36 h. This difference in the rate of activation of the antioxidant system may be crucial in maintaining cellular redox homeostasis of this genotype. At this stage of development, the tolerant and the intermediate genotypes showed a stimulation of root growth while the sensitive type showed significant growth retardation. In order to compare plant species, cucumber was placed in hydroponic growth medium with the oat seedlings (sensitive and tolerant genotypes.) When cucumber was placed in hydroponic solution exposed to 20 mg/L Al along with the tolerant (UFRGS 17) and the sensitive (UFRGS 930 598) genotypes, it showed similarities with the sensitive genotype (increased catalase activity after 36 h of exposure to Al). The levels of lipid peroxidation were high after 12, 24, and 36h of exposure to Al and as a consequence there was a reduction in root growth. Considering the evaluation with tolerant (UFRGS 17) and sensitive (UFRGS 930 598) oat genotypes, the cucumber may be considered an Al-sensitive species. / O alumínio (Al) é o metal mais abundante na crosta terrestre, afetando o crescimento e desenvolvimento das plantas. Neste estudo, foram investigados através da análise de parâmetros bioquímicos e fisiológicos, os efeitos do alumínio (Al) em plântulas de pepino (Cucumis sativus L.) e em plântulas de aveia (Avena sativa L). As plântulas de aveia estudadas pertencem a três diferentes genótipos: UFRGS 930598-sensível ao alumínio, UFRGS 17-tolerante ao alumínio e UFRGS 280-intermediário ao alumínio (resultante do cruzamento entre UFRGS 930598 e UFRGS 17), expostos a 0, 5, 10, 20 e 30 mg/L de Al. Os parâmetros bioquímicos analisados para C. sativus foram: a atividade das enzimas antioxidantes (catalse (CAT), ascorbato peroxidase (APX) e superóxido dismutase (SOD)), os níveis de peroxidação lipídica, vazamento de eletrólitos, oxidação de proteínas e conteúdo de clorofila. O aumento na porcentagem de vazamento de eletrólitos e na produção de peróxido de hidrogênio observado está relacionado com a diminuição da eficiência do sistema antioxidante nas concentrações mais altas de alumínio. O sistema antioxidante foi incapaz de impedir a toxicidade, resultando em efeitos negativos, tais como peroxidação lipídica, oxidação de proteínas e diminuição do crescimento das plantas. Plântulas dos três genótipos de aveia foram expostas ao Al em diferentes meios de crescimento. Primeiro a exposição foi em meio de crescimento semi-sólido com agar por 5 dias, com plântulas com 5 dias de desenvolvimento, depois em solução hidropônica por 7 dias com plântulas com 10 dias de desenvolvimento. Foram avaliados o conteúdo de peróxido de hidrogênio, peroxidação de lipídeos, conteúdo de ácido ascórbico e tióis não protéicos (NPSH), a atividade das enzimas CAT, APX e SOD e o conteúdo de Al acumulado nas plântulas. As enzimas do sistema antioxidante SOD e CAT tiveram suas atividades aumentadas nos genótipos UFRGS 17 e UFRGS 280. Mesmo acumulando altas concentrações de alumínio estes dois genótipos não apresentaram altos níveis de peroxidação lipídica e conteúdo de peróxido de hidrogênio quando comparados com o genótipo 930598. Para esse genótipo houve ativação da enzima APX, entretanto os altos níveis de alumínio acumulados na planta causaram um aumento na peroxidação de lipídeos e no conteúdo de peróxido de hidrogênio. O genótipo UFRGS 930598 mostrou ser mais sensível ao alumínio que os genótipos UFRGS 17 e UFRGS 280, o que confirma as análises morfológicas prévias obtidas por FEDERIZZI et al., 2000. Embora tenha ocorrido um aumento da atividade da APX neste genótipo, o sistema antioxidante não foi eficiente na remoção das espécies reativas de oxigênio (EROS). Com a finalidade de melhor entender esses resultados foi utilizado o meio de crescimento com solução hidropônica onde a mobilidade do metal é maior por um período de exposição de 7 dias com plântulas de aveia com 10 dias de desenvolvimento. Neste experimento além dos parâmetros bioquímicos citados acima, foi feita a análise do crescimento da raiz e parte aérea, matéria seca e fresca, conteúdo de clorofila, atividade da enzima δ -aminolevulinato desidratase (δ-ALA-D) e o monitoramento do pH da solução hidropônica de cada genótipo. O pH da solução hidropônica do genótipo tolerante (UFRGS 17) apresentou um aumento significativo nos valores de pH, enquanto os genótipos sensíveis (UFRGS 930598) e intermediário (UFRGS 280) não apresentaram mudanças significativas nos valores de pH. O genótipo sensível teve inibição do crescimento da raiz e parte aérea nas concentrações mais altas de alumínio enquanto que para o genótipo tolerante e intermediário, não houve modificações significativas do crescimento da raiz e parte aérea. A atividade das enzimas antioxidantes foi aumentada após 7 dias de exposição ao alumínio no genótipo sensível, enquanto que no genótipo tolerante não houve aumento na atividade das enzimas antioxidantes. Nas plântulas do genótipo intermediário houve o aumento na atividade das enzimas CAT, APX e SOD apenas nas maiores concentrações de alumínio (20 e 30 mg/L). Os resultados mostram que os genótipos intermediário e tolerante apresentaram semelhanças quanto ao efeito do alumínio na atividade das enzimas do sistema antioxidante e também nos parâmetros fisiológicos como o crescimento das raízes e parte aérea. Mesmo acumulando altas concentrações de alumínio, o genótipo intermediário não apresentou diminuição do crescimento, o que mostra que ele apresenta mecanismos de resistência, relacionado com a imobilização interna deste metal nos vacúolos. O genótipo tolerante também apresenta mecanismos de resistência ao alumínio, porém estes mecanismos podem ser de exclusão do alumínio pela raiz através da ligação deste metal a ácidos orgânicos. Com a finalidade de investigar quando o sistema antioxidante é ativado nos diferentes genótipos de aveia, as plântulas foram colocadas no meio de crescimento com solução hidropônica e retiradas do meio após 12, 24 e 36 horas de exposição a 20 mg/L de Al. Os genótipos tolerante e intermediário apresentaram aumento na atividade das enzimas do sistema antioxidante após 12 h de exposição ao alumínio, enquanto o genótipo sensível somente após 24 ou 36 horas de exposição. Esta diferença na velocidade de ativação do sistema antioxidante pode ser crucial na manutenção da homeostase celular redox deste genótipo. Nessa fase do desenvolvimento, o genótipo tolerante e o intermediário apresentaram um estímulo do crescimento da raiz enquanto o sensível um atraso do crescimento. Com a finalidade de estabelecer comparações entre as espécies vegetais, o pepino (Cucumis sativus) foi colocado em meio de crescimento hidropônico, juntamente com as plântulas de aveia (genótipo sensível e tolerante). O pepino (Cucumis sativus) quando colocado em solução hidropônica exposto a 20 mg/L de alumínio juntamente com o genótipo tolerante (UFRGS 17) e o genótipo sensível (UFRGS 930598), apresentou semelhanças com o genótipo sensível tais como o aumento da atividade da enzima catalase após 36 h de exposição ao alumínio. Os níveis de peroxidação lipídica foram elevados após 12, 24 e 36h de exposição ao alumínio e como conseqüência a raiz teve uma diminuição do crescimento. Através da avaliação conjunta, com os genótipos de aveia tolerante, UFRGS 17, e sensível, UFRGS 930598, o pepino (Cucumis sativus) pode ser considerado uma espécie sensível ao alumínio.

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