http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Karla F. García-Verdugo,Andya J. Ramírez-Irigoyen,Mónica Castillo-Ortega,Dora E. Rodríguez-Félix,Jesús M. Quiroz-Castillo,Judith Tánori-Córdova,Francisco Rodríguez-Félix,Antonio Ledezma-Pérez,Teresa d 한국고분자학회 2022 Macromolecular Research Vol.30 No.6
A novel semi-interpenetrating polymer network (s-IPN) based on the entrapment of a thermosensitive polymer, the poly(vinyl methyl ether) (PVME), within a crosslinked 3D structure of poly(vinyl alcohol) (PVA) and poly(vinyl methyl etheralt- maleic acid) (COP) was synthesized by an autoclaving process. The preparation method avoids the use of toxic crosslinkers and allows the simultaneous sterilization of material. The PVA/COP/PVME hydrogel were characterized by Fourier transform infrared spectroscopy, thermal techniques, swelling kinetic measurements, scanning electron microscopy, and rheological analysis. The entrapment of PVME within the hydrated polymer framework significantly modified its transition temperature at pH 7.4 and pH 3 conditions. The swelling kinetics of the s-IPN were dependent on pH (7.4, 3 and 1), and temperature (25 and 37℃). The interpenetrated polymer chains reduced the internal pore sizes of crosslinked network without altering its elastic, solid-like behavior. The loading and in vitro release of 5-fluorouracil, a chemotherapeutic agent, from hydrogel systems were studied at different temperature and pH values. The hydrogels showed a sustained drug release up to 5 h at 37℃, in different pH media. The s-IPN exhibited a promising performance for a range of biomedical applications, in particular, for the controlled drug delivery in response to the pH and temperature conditions.
Itzel Margarita Córdova-Alcántara,Diana Laura Venegas-Cortés,María Ángeles Martínez-Rivera,Néstor Octavio Pérez,Aida Verónica Rodriguez-Tovar 한국미생물학회 2019 The journal of microbiology Vol.57 No.6
Fusarium solani has drawn phytopathogenic, biotechnological, and medical interest. In humans, it is associated with localized infections, such as onychomycosis and keratomycosis, as well as invasive infections in immunocompromised patients. One pathogenicity factor of filamentous fungi is biofilm formation. There is still only scarce information about the in vitro mechanism of the formation and composition of F. solani biofilm. In this work, we describe the biofilm formed by a clinical keratomycosis isolate in terms of its development, composition and susceptibility to different antifungals and ultraviolet light (UV) at different biofilm formation stages. We found five biofilm formation stages using scanning electron microscopy: adherence, germination, hyphal development, maturation, and cell detachment. Using epifluorescence microscopy with specific fluorochromes, it was elucidated that the extracellular matrix consists of carbohydrates, proteins, and extracellular DNA. Specific inhibitors for these molecules showed significant biofilm reductions. The antifungal susceptibility against natamycin, voriconazole, caspofungin, and amphotericin B was evaluated by metabolic activity and crystal violet assay, with the F. solani biofilm preformation to 24 h increased in resistance to natamycin, voriconazole, and caspofungin, while the biofilm preformation to 48 h increased in resistance to amphotericin B. The preformed biofilm at 24 h protected and reduced UV light mortality. F. solani isolate could produce a highly structured extra biofilm; its cellular matrix consists of carbohydrate polymers, proteins, and eDNA. Biofilm confers antifungal resistance and decreases its susceptibility to UV light. The fungal biofilm functions as a survival strategy against antifungals and environmental factors.
Cíntia De Lorenzo,Caroline P. de Andrade,Verônica S. L. Machado,Matheus V. Bianchi,Veronica M. Rolim,Raquel A. S. Cruz,David Driemeier 대한수의학회 2018 Journal of Veterinary Science Vol.19 No.1
Enterotoxigenic Escherichia coli (ETEC) causes diarrhea in pigs, referred to as colibacillosis. The aim of this study was to optimize multiplex polymerase chain reaction (PCR) and immunohistochemistry (IHC) analyses of paraffin-embedded material to detect pathogenic E. coli strains causing colibacillosis in pigs. Multiplex PCR was optimized for fimbriae (F18, F4, F6, F5, and F41) and toxins (types A and B heat-stable toxins [STaP and STb], heat-labile toxin [LT], and type 2 Shiga toxin [STx2e]), and IHC was optimized for an anti-E. coli polyclonal antibody. Samples (132) from pigs received between 2006 and 2014 with clinical and histopathological diagnoses of colibacillosis were analyzed. E. coli was detected by IHC in 78.7%, and at least one virulence factor gene was detected in 71.2%. Pathogenic strains of ETEC with at least one fimbria and one toxin were detected in 40% of the samples in multiplex PCR. The most frequent virulence types were F18-STaP (7.5%), F18-STaP-STb (5.7%), and F4-STaP (3.8%). A statistically significant association was noted between virulence factors F4, F18, STaP, and STb and positive immunostaining results. Colibacillosis diagnosis through multiplex PCR and IHC of paraffin-embedded tissues is a practical approach, as samples can be fixed and stored for long periods before analysis.