Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 7 de 7
Filter
Add more filters










Publication year range
1.
Water Res ; 219: 118506, 2022 Jul 01.
Article in English | MEDLINE | ID: mdl-35576760

ABSTRACT

The international campaign to ban bisphenol A (BPA) has resulted in increasing application of BPA substitutes. However, investigations have mainly been confined to the removal of single contaminant from the water, resulting in an inefficient burden. Furthermore, systematic study and synthetical discussion of bisphenol analogues (BPs) kinetics and transformation pathways were largely underemphasized. Chemical oxidation of BPA and four typical alternatives (i.e., bisphenol AF, bisphenol E, bisphenol F and bisphenol S) in a UV-activated persulfate system was examined in this study. The effects of persulfate (PS) dosage, pH and water matrix constituents (i.e., bicarbonate, chloride and natural organic matter) were comprehensively examined using a combination of laboratory experiments and mathematical modeling. According to our findings, the removal characteristics of different BPs employing SO4•--induced removal technology, including degradation mechanisms and influencing trends by water matrix, revealed similarly. The second order-rate constants of SO4•- reacting with BPs served as the main variables mediating the variation in degradation kinetics. Frontier molecular orbital theory and density functional theory suggested BPs molecules possessed the same susceptible positions to free radicals. In the UV-activated PS process, transformation pathways included hydroxylation, electron-transfer, substitution, and rearrangement triggered by ortho-cleavage, with certain intermediates exhibiting higher toxicity than the parent chemicals. The findings of this study provided valuable information to estimate potential environmental risks of using BPA alternatives.


Subject(s)
Water Pollutants, Chemical , Benzhydryl Compounds/chemistry , Kinetics , Phenols , Sulfates , Water , Water Pollutants, Chemical/chemistry
2.
Water Air Soil Pollut ; 229(5): 154, 2018.
Article in English | MEDLINE | ID: mdl-29755149

ABSTRACT

In this paper, coke wastewater that had passed through biological and integrated membrane processes (filtration on sand bed-reverse osmosis) was chosen to assess the phytotoxicity of selected industrial wastewater with regard to the test plant-Vicia faba. An innovative research technique in vitro test was conducted in a large scale phytothrone chamber on two matrices: cotton and Murashige and Skoog Basal Medium (MSBM). The toxicity of wastewater was evaluated for samples: (1) treated in the treatment plant by biological processes, (2) filtrated through a sand bed and filtrated (3) reverse osmosis (RO) membrane. The results showed that there is a noticeable correlation between increasing concentrations of wastewater and seed germination of the test plant. Although the wastewater collected from the coke plant was treated biologically, it showed very high levels of germination inhibition (90-98% for cotton matrix and 92-100% for MSBM matrix) and strong toxic effects. The wastewater collected from the coke plant showed a significantly greater phytotoxic effect compared with those obtained from the effluent treated on a sand bed and in RO. However, wastewater, even after treatment on a sand bed (reduction of COD-39%, TN-46%, TOC-42%, TC-47%, SS-50%, 16PAHs-53%), was still toxic and germination inhibition was in the range of 24-48% for the cotton matrix and 14-54% for the MSBM matrix. The toxicity of wastewater treated in the membrane process was the lowest (reduction of COD-85%, TN-95%, TOC-85%, TC-86%, SS-98%, 16PAHs-67%). The germination inhibition was in the range of 4-10% for the cotton matrix and 2-12% for the MSBM matrix. These samples are classified as non-toxic or slightly toxic to the model plant. The present study highlights the necessity of monitoring not only the basic physical and chemical indicators (including the level of toxic substances as PAHs), but also their effect on the test organisms in wastewater samples.

3.
Ecotoxicol Environ Saf ; 134P1: 43-52, 2016 Dec.
Article in English | MEDLINE | ID: mdl-27584823

ABSTRACT

Elevated concentrations of heavy metals and antibiotics often coexist in agricultural soils due to land application of large amounts of animal manure. The experiment was conducted to investigate the single and joint effects of different concentrations of sulfadiazine (SDZ) (10mgkg-1 and 100mgkg-1) and copper (Cu) (20mgkg-1 and 200mgkg-1) on soil microbial activity, i.e. fluorescein diacetate (FDA) hydrolysis, dehydrogenase (DHA) and basal respiration (BR), microbial biomass and community structure estimated using phospholipid fatty acids (PLFA), and community level physiological profiles (CLPP) using MicroResp™. High concentration of SDZ or Cu significantly reduced microbial activity during the whole incubation period, while the inhibiting effect of low concentration of SDZ or Cu was only visible within 14 days of incubation. The total PLFA concentration was reduced by SDZ and/or Cu, which resulted from reduced bacterial and actinomycetic biomass. The addition of SDZ and/or Cu decreased the bacteria:fungi ratio, whereas only the addition of high Cu concentration significantly decreased Gram+:Gram- ratio. The addition of Cu obviously inhibited the dissipation of SDZ, which could affect the combined effects of both on microbial activity, biomass and community structure. Principal component analysis of the CLPP and PLFA data clearly revealed the notable effects of SDZ and/or Cu on soil microbial community structure.

4.
Aquat Toxicol ; 163: 102-8, 2015 Jun.
Article in English | MEDLINE | ID: mdl-25885475

ABSTRACT

Didimosphenia geminata ("didymo"), has become a powerful and devastating river plague in Chile. A system was developed in D. geminata channels with the purpose evaluating the effects of water polluted with didymo on the activation of Atlantic salmon (Salmo salar) spermatozoa. Results indicate that semen, when activated with uncontaminated river water had an average time of 60±21s. When using Powermilt, (a commercial activator), times of 240±21s are achieved, while rivers contaminated with D. geminata achieve a motility time of 30±12s. Interestingly enough, the kinetic parameters of VSL, VCL and VAP showed no significant changes under all of the conditions. Furthermore, the presence of D. geminata reduces activation time of the samples as the cells age, indicating increased effects in spermatozoa that are conserved for more than 5 days. D. geminata has antioxidant content, represented by polyphenols; 200ppm of polyphenol were obtained in this study per 10g of microalgae. Spermatozoa exposed to these extracts showed a reduction in mobility time in a dose dependent manner, showing an IC50 of 15ppm. The results suggest an effect on spermatozoa activation, possibly due to the release of polyphenols present in contaminated rivers, facilitating the alteration of sperm motility times, without affecting the viability or kinetics of the cells. These findings have important implications for current policy regarding the control of the algae. Current control measures focus on the number of visible species, and not on the compounds that they release, which this study shows, also have a problematic effect on salmon production.


Subject(s)
Diatoms/metabolism , Fresh Water/chemistry , Salmo salar/physiology , Spermatozoa/physiology , Animals , Antioxidants/metabolism , Antioxidants/pharmacology , Diatoms/chemistry , Male , Microscopy, Confocal , Polyphenols/metabolism , Polyphenols/pharmacology , Rivers/chemistry , Sperm Motility/drug effects , Sperm Motility/physiology , Spermatozoa/drug effects
5.
Arq. bras. oftalmol ; 70(4): 657-666, jul.-ago. 2007. ilus, graf, tab
Article in Portuguese | LILACS | ID: lil-461956

ABSTRACT

OBJETIVO: Avaliar o epitélio ciliar interno (ECI) do corpo ciliar após aplicação de mitomicina C (MMC) sob retalho escleral, em animais tratados com dois tipos de inibidores da produção do humor aquoso. MÉTODOS: Foram estudados ambos os olhos de 16 coelhos divididos em 4 grupos experimentais. Foi realizado retalho escleral em todos os olhos dos animais, mas apenas os olhos direitos (OD) receberam MMC. No grupo 1 (G1) não houve tratamento prévio. Nos grupos G2 e G4 foi administrada acetazolamida e nos grupos G3 e G4 maleato de timolol. O ECI foi examinado à microscopia eletrônica de transmissão (MET). Os olhos esquerdos formaram os grupos controle. RESULTADOS: Em todos os grupos exceto no G1 OE, foram observadas: retração das células e/ou alargamento entre invaginações, mitocôndrias com rarefação, vesículas claras e corpos densos. A membrana limitante interna estava espessada, descontínua ou descolada em todos grupos exceto G1 OE e G2 OE. Foi observada liberação de material citoplasmático apenas nos grupos tratados com inibidores da produção de humor aquoso. CONCLUSÕES: 1- MMC, acetazolamida e maleato de timolol causaram alterações morfológicas no epitélio ciliar mesmo usados isoladamente. 2- A associação MMC e acetazolamida causou mais alterações do que a acetazolamida isoladamente, mas não mais do que a MMC isoladamente. 3- Nas demais associações as alterações foram semelhantes.


PURPOSE: To evaluate the effects of mitomycin C (MMC) on the internal ciliary epithelium (ICE) of the ciliary body of animals treated with two differents aqueous humor supressants. METHODS: The eyes of sixteen Norfolk albino rabbits divided into four experimental groups were studied. The right eyes (RE) of the four groups received 0.1 ml of MMC (0.5 mg/ml) under the scleral flap. The left eyes (LE) was the control group. Group 1 (G1) did not have any other treatment. To Group 2 (G2) and Group 4 (G4) acetazolamide was administered. To Group (G3) and Group 4 (G4) timolol maleate was administered. ICE was examined by transmission electron microscopy (TEM). RESULTS: The following aspects were observed in all groups, except in G1 LE: cell shrinkage and/or enlargement of intercellular spaces, rarefied mitochondria, clear vesicular structures and electron-dense bodies. The internal limitant membrane showed to be thickened, discontinued and separeted in all groups, except in G1 LE and G2 LE. Discharge of cytoplasmatic material was observed only in the groups treated with aqueous humor supressants. CONCLUSIONS: 1) MMC, acetazolamide and timolol maleate caused morphological alterations in the ciliary epithelium even when used alone. 2) The combination of MMC and acetazolamide caused more alterations than did isolated acetazolamide, but not more than MMC alone. 3) For the other combinations the alterations were similar.


Subject(s)
Animals , Rabbits , Antibiotics, Antineoplastic/toxicity , Aqueous Humor/drug effects , Ciliary Body , Mitomycin/toxicity , Sclera/surgery , Acetazolamide/adverse effects , Acetazolamide/therapeutic use , Adrenergic beta-Antagonists/adverse effects , Adrenergic beta-Antagonists/therapeutic use , Carbonic Anhydrase Inhibitors/adverse effects , Carbonic Anhydrase Inhibitors/therapeutic use , Ciliary Body/drug effects , Ciliary Body/ultrastructure , Epithelium/drug effects , Epithelium/ultrastructure , Microscopy, Electron , Models, Animal , Mitomycin/administration & dosage , Random Allocation , Surgical Flaps , Timolol/adverse effects , Timolol/therapeutic use
6.
China Pharmacy ; (12)2007.
Article in Chinese | WPRIM (Western Pacific) | ID: wpr-534365

ABSTRACT

OBJECTVE:To study antibacterial and anti-inflammatory effect of Maqin zhike syrup. METHODS:In vitro antibacterial test, mice ear swelling test and mice abdominal capillary permeability test were adopted to observe the antibacterial and anti-inflammatory effect of Maqin zhike syrup. RESULTS:Maqin zhike syrup could inhibit gram-negative and gram-positive bacteria, mice ear swelling, and reduce abdominal capillary permeability. It also enhanced humoral and cellular immunity. CONCLUSION:Maqin zhike syrup has the effect on bacterials, inflammatory and immunity with high safety.

7.
Gac. méd. Méx ; 141(1): 13-21, ene.-feb. 2005. ilus, tab
Article in Spanish | LILACS | ID: lil-632105

ABSTRACT

La caracterización de las actividades tóxicas de los venenos de serpientes es necesaria para el cabal entendimiento de los procesos fisiopatológicos que se producen ante su mordedura, como también para evaluar la potencia neutralizante de los antivenenos utilizados para tratar estos envenenamientos. A causa de los pocos datos disponibles sobre la toxicidad del veneno de serpientes con importancia sanitaria en México, estudiamos las actividades tóxicas de los venenos de Bothrops asper, Athropoides nummifer, Agkistrodon billineatus> Crotalus durissus durissus, Crotalus basiliscus, Crotalus scutulatus, Crotalus atrox y Micrurus nigrocinctus. A los venenos se les realizaron los siguientes estudios: SDS-PAUE, determinación de la potencia letal, y de las actividades hemorrágica, necrotizante, coagulante en plasma y fibrinógeno, fosfolipásica y fibrinogenolítica. Se estudió además la capacidad neutralizante de un antiveneno de uso corriente para la terapéutica de las mordeduras de serpientes venenosas en México, sobre varias de estas actividades. Los venenos de vipéridos mostraron actividades hemorrágicas, necrotizante, coagulante sobre plasma, protrombínica, fibrinogenolítica y fosfolipásica importantes. Los venenos de mayor potencia letal fueron los de Micrurus nigrocinctus y Crotalus scutulatus, sin embargo el veneno que presentó en general potencias tóxicas mayores fue el de Bothrops asper. Las diferentes potencias tóxicas halladas se encontraron dentro de los márgenes descritos para especies de vipéridos y elápidos de Sudamérica. La actividad sobre el plasma y el fibrinógeno fue muy diferente en los diferentes venenos viperinos, sin embargo todos mostraron ser capaces de afectar componentes del sistema de la coagulación. El antiveneno probado no sólo neutralizó la letalidad del veneno sino también sus actividades tóxicas.


The characterization of the toxic activities of snake venoms is necessary to understand the physiopathology of the envenomation and to test the potency of the antivenoms used to treat this pathology. Because of the lack of data on the toxic activities of venoms from Mexican snakes of medical importance, we studied the venoms from Bothrops asper, Athropoides nummifer, Agkistrodon billineatus, Crotalus durissus durissus, Crotalus basiliscus, Crotalus scutulatus, Crotalus atrox and Micrurus nigrocinctus. The studies performed were : SDS-PAOE, determination of lethal potency, hemorrhagic, necrotizing, coagulation on plasma and fibrinogen, phospholipasic and fibrinogenolytic activities. In addition we studied the neutralizing capacity of the toxic activities of an antivenom currently used for the treatment of snakebites in Mexico. The venom from viperids showed important hemorrhagic, necrotizing, coagulative on plasma, prothrombinic, fibrinogenolytic and phospholipase activities. The venoms with the highest lethal potency were those of Micrurus nigrocinctus and Crotalus scutulatus; however, the viperine venom that globally displayed the most potent toxic activities was from Bothrops asper. All the venoms showed toxic activities of similar range to those described for other American venomous snakes. The activity on plasma or fibrinogen varied widely among the different venoms but all displayed capacity to act on the coagulation system. The antivenom tested not only neutralized the lethalityB. asper venom but also its other toxic activities.


Subject(s)
Animals , Mice , Snake Venoms/toxicity , Mexico
SELECTION OF CITATIONS
SEARCH DETAIL
...