Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 7 de 7
Filtrar
Más filtros












Base de datos
Intervalo de año de publicación
1.
J Funct Biomater ; 14(7)2023 Jul 14.
Artículo en Inglés | MEDLINE | ID: mdl-37504866

RESUMEN

Recently, tissue engineering, including 3D bioprinting of the pancreas, has acquired clinical significance and has become an outstanding potential method of customized treatment for type 1 diabetes mellitus. The study aimed to evaluate the function of 3D-bioprinted pancreatic petals with pancreatic islets in the murine model. A total of 60 NOD-SCID (Nonobese diabetic/severe combined immunodeficiency) mice were used in the study and divided into three groups: control group; IsletTx (porcine islets transplanted under the renal capsule); and 3D bioprint (3D-bioprinted pancreatic petals with islets transplanted under the skin, on dorsal muscles). Glucose, C-peptide concentrations, and histological analyses were performed. In the obtained results, significantly lower mean fasting glucose levels (mg/dL) were observed both in a 3D-bioprint group and in a group with islets transplanted under the renal capsule when compared with untreated animals. Differences were observed in all control points: 7th, 14th, and 28th days post-transplantation (129, 119, 118 vs. 140, 139, 140; p < 0.001). Glucose levels were lower on the 14th and 28th days in a group with bioprinted petals compared to the group with islets transplanted under the renal capsule. Immunohistochemical staining indicated the presence of secreted insulin-living pancreatic islets and neovascularization within 3D-bioprinted pancreatic petals after transplantation. In conclusion, bioprinted bionic petals significantly lowered plasma glucose concentration in studied model species.

2.
Z Relig Ges Polit ; 6(1): 27-41, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-34938948

RESUMEN

The aims of this paper are to investigate 1) how the Seventh-Day Adventist Church in Poland has reacted to the COVID-19 pandemic restrictions and lockdowns imposed nationwide, 2) how the pandemic context has influenced the Church's digital media productions, and 3) how the Church has adapted to some of the trends and consequences of deep mediatization (Hepp et al. 2017, 2018). Based in the constructivist concept of deep mediatization (Hepp et al. 2017, 2018), the paper analyzes interviews with Seventh-Day Adventist media professionals from Poland within the framework of the Sociology of Knowledge Approach to Discourse. Additionally, selected official YouTube channels of local congregations in Poland are analyzed quantitatively to identify the changes in the number of uploads and views. The analyses show that as a result of the COVID-19 lockdowns and restrictions, media production and use increased substantially in some digital media formats produced by the Seventh-Day Adventist Church, which was on the one hand a response to the pandemic context as such, and on the other hand, a reaction to the discriminatory laws which drastically limited the Church's activities offline. The pandemic has opened up new possibilities of participation, but also increased the chances of digital divides and exclusions. The study concludes that to mitigate the risks related to digital divides during the pandemic, some Polish pastors took on the roles of media experts and educators, incorporating technical skills in their authority status. This suggests that transformations of religious authority may be another consequence of deep mediatization processes.

3.
Nanomaterials (Basel) ; 11(11)2021 Nov 10.
Artículo en Inglés | MEDLINE | ID: mdl-34835782

RESUMEN

Chitosan is one of the most well-known and characterized materials applied in tissue engineering. Due to its unique chemical, biological and physical properties chitosan is frequently used as the main component in a variety of biomaterials such as membranes, scaffolds, drug carriers, hydrogels and, lastly, as a component of bio-ink dedicated to medical applications. Chitosan's chemical structure and presence of active chemical groups allow for modification for tailoring material to meet specific requirements according to intended use such as adequate endurance, mechanical properties or biodegradability time. Chitosan can be blended with natural (gelatin, hyaluronic acid, collagen, silk, alginate, agarose, starch, cellulose, carbon nanotubes, natural rubber latex, κ-carrageenan) and synthetic (PVA, PEO, PVP, PNIPPAm PCL, PLA, PLLA, PAA) polymers as well as with other promising materials such as aloe vera, silica, MMt and many more. Chitosan has several derivates: carboxymethylated, acylated, quaternary ammonium, thiolated, and grafted chitosan. Its versatility and comprehensiveness are confirming by further chitosan utilization as a leading constituent of innovative bio-inks applied for tissue engineering. This review examines all the aspects described above, as well as is focusing on a novel application of chitosan and its modifications, including the 3D bioprinting technique which shows great potential among other techniques applied to biomaterials fabrication.

4.
J Hazard Mater ; 260: 468-74, 2013 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-23811368

RESUMEN

Sulfonamides (SAs) and their metabolites present severe hazards to human health and the environment, mainly because of antibiotic resistance. Knowledge of their bioavailability, including their sorption to soils and their impact on the soil-groundwater pathway, is crucial to their risk assessment. Laboratory batch and column leaching tests are important tools for determining the release potential of contaminants from soil or waste materials. Batch and column tests were carried out with soils differing in particle size distribution, organic matter content and pH, each spiked with sulfonamides (sulfadimethoxine (SDM), sulfaguanidine (SGD), sulfisoxazole (SX)). In order to test the applicability of leaching tests to polar contaminants batch and column tests were also compared. In the column tests, release was found to depend on the properties of both soil and sulfonamides. The fastest release was observed for coarse-grained soil with the smallest organic matter content (MS soil; 100% decrease in concentration until liquid-to-solid ratio (L/S) of 0.9 L kg(-1) for all SAs). The slowest release was established for sulfadimethoxine (24.5% decrease in concentration until L/S 1.22 L kg(-1)). The results of the batch and column tests were comparable to a large extent, with slightly higher concentrations being obtained in the column test experiments of fine-grained soils with a high organic matter content.


Asunto(s)
Contaminantes del Suelo/análisis , Sulfonamidas/química , Carbono/química , Monitoreo del Ambiente , Concentración de Iones de Hidrógeno , Reproducibilidad de los Resultados , Medición de Riesgo , Suelo , Contaminantes del Suelo/química , Sulfadimetoxina/análisis , Sulfaguanidina/análisis , Sulfisoxazol/análisis , Residuos/análisis , Contaminantes del Agua , Contaminantes Químicos del Agua/análisis
5.
Chemosphere ; 92(9): 1253-9, 2013 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-23689096

RESUMEN

Doramectin (DOR), metronidazole (MET), florfenicol (FLO), and oxytetracycline (OXT) are among the most widely used veterinary drugs in animal husbandry or in aquaculture. Contamination of the environment by these pharmaceuticals has given cause for concern in recent years. Even though their toxicity has been thoroughly analyzed, knowledge of their ecotoxicity is still limited. We investigated their aquatic toxicity using tests with marine bacteria (Vibrio fischeri), green algae (Scenedesmus vacuolatus), duckweed (Lemna minor) and crustaceans (Daphnia magna). All the ecotoxicological tests were supported by chemical analyses to confirm the exposure concentrations of the pharmaceuticals used in the toxicity experiments, since deviations from the nominal concentration can result in underestimation of biological effects. It was found that OXT and FLO have a stronger adverse effect on duckweed (EC50=3.26 and 2.96mgL(-1) respectively) and green algae (EC50=40.4 and 18.0mgL(-1)) than on bacteria (EC50=108 and 29.4mgL(-1)) and crustaceans (EC50=114 and 337mgL(-1)), whereas MET did not exhibit any adverse effect in the tested concentration range. For DOR a very low EC50 of 6.37×10(-5)mgL(-1) towards D. magna was determined, which is five orders of magnitude lower than values known for the toxic reference compound K2Cr2O7. Our data show the strong influence of certain veterinary drugs on aquatic organisms and contribute to a sound assessment of the environmental hazards posed by commonly used pharmaceuticals.


Asunto(s)
Aliivibrio fischeri/efectos de los fármacos , Araceae/efectos de los fármacos , Chlorophyta/efectos de los fármacos , Daphnia/efectos de los fármacos , Contaminantes Ambientales/toxicidad , Drogas Veterinarias/toxicidad , Crianza de Animales Domésticos , Animales , Araceae/crecimiento & desarrollo , Chlorophyta/fisiología , Daphnia/fisiología , Contaminantes Ambientales/química , Ivermectina/análogos & derivados , Ivermectina/química , Ivermectina/toxicidad , Metronidazol/química , Metronidazol/toxicidad , Oxitetraciclina/química , Oxitetraciclina/toxicidad , Reproducción/efectos de los fármacos , Tianfenicol/análogos & derivados , Tianfenicol/química , Tianfenicol/toxicidad , Drogas Veterinarias/química
6.
J Hazard Mater ; 221-222: 264-74, 2012 Jun 30.
Artículo en Inglés | MEDLINE | ID: mdl-22579461

RESUMEN

Hydrolysis is one of the most common reactions controlling abiotic degradation and is one of the main paths by which substances are degraded in the environment. Nevertheless, the available information on this process for many compounds, including sulphonamides (a group of antibiotic drugs widely used in veterinary medicine), is very limited. This is the first study investigating the hydrolytic stabilities of 12 sulphonamides, which were determined according to OECD guideline 111 (1st category reliability data on the basis of regulatory demands on data quality for the environmental risk assessment of pharmaceuticals). Hydrolysis behaviour was examined at pH values normally found in the environment. This was prefaced by a discussion of the acid-base properties of sulphonamides. All the sulphonamides tested were hydrolytically stable at pH 9.0, nine (apart from sulphadiazine, sulphachloropyridazine and sulphamethoxypyridazine) were stable in this respect at pH 7.0 and two (sulphadiazine and sulphaguanidine) at pH 4.0 (hydrolysis rate≤10%; t(0.5 (25°C))>1 year). The degradation products were identified, indicating two independent mechanisms of this process. Our results show that under typical environmental conditions (pH and temperature) sulphonamides are hydrolytically stable with a long half-life; they thus contribute to the on-going assessment of their environmental fate.


Asunto(s)
Sulfonamidas/química , Agua/química , Cromatografía Líquida de Alta Presión , Concentración de Iones de Hidrógeno , Hidrólisis , Soluciones
7.
Chemosphere ; 86(10): 1059-65, 2012 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-22197018

RESUMEN

Sulfonamides (SAs) are one of the oldest groups of veterinary chemotherapeutic agents. As these compounds are not completely metabolized in animals, a high proportion of the native form is excreted in feces and urine. They are therefore released either directly to the environment in aquacultures and by grazing animals, or indirectly during the application of manure or slurry. Once released into the environment, SAs become distributed among various environmental compartments and may be transported to surface or ground waters. The physicochemical properties of SAs, dosage and nature of the matrix are the factors mainly responsible for their distribution in the natural environment. Although these rather polar compounds have been in use for over half a century, knowledge of their fate and behavior in soil ecosystems is still limited. Therefore, in this work we have determined the sorption potential of sulfadimethoxine and sulfaguanidine on various natural soils. The influence on sorption of external factors, such as ionic strength and pH, were also determined. The sorption coefficients (K(d)) obtained for the sulfonamides investigated were quite low (from 0.20 to 381.17 mL g(-1) for sulfadimethoxine and from 0.39 to 35.09 mL g(-1) for sulfaguanidine), which indicated that these substances are highly mobile and have the potential to run off into surface waters and/or infiltrate ground water. Moreover, the sorption of these pharmaceuticals was found to be influenced by OC, soil solution pH and ionic strength, with higher K(d) values for soils of higher OC and lower K(d) values with increasing pH and ionic strength.


Asunto(s)
Antiinfecciosos/química , Contaminantes del Suelo/química , Suelo/química , Sulfadimetoxina/química , Sulfaguanidina/química , Adsorción , Antiinfecciosos/análisis , Modelos Químicos , Contaminantes del Suelo/análisis , Sulfadimetoxina/análisis , Sulfaguanidina/análisis
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...