In the present study, predominant lactic acid bacteria (LAB) were isolated from oat sourdough. Then, the isolates were screened based on their in vitro antifungal activity. Subsequently, biotechnological capabilities of the selected LAB were evaluated in wheat bread supplemented with controlled fermented oat containing the isolate. Pediococcus pentosaceus was molecular identified as predominant antifungal isolate. Based on our results, fermented oat not only significantly (p < .05) reduced the mold expansion on the produced breads, but also improved the quality attributes of the product. Crumb porosity and antioxidant capacity of the supplemented bread revealed the positive effects of the isolate on textural and functional characteristics of the enriched bread. Wheat bread supplemented with controlled fermented oat had also the highest 2,2‐diphenyl‐1‐picrylhydrazyl radical scavenging activity compared to the other samples. Accordingly, the potential applications of P. pentosaceus isolate as profunctional starter culture in processing of mixed wheat‐oat sourdough bread were verified. 相似文献
Magnetic nanoparticles, Fe3O4, have been prepared and functionalized by (N-(3-(triethoxysilyl)propyl)isonicotinamide) and characterized by infrared spectroscopy, thermal analysis (TGA/DTA), X-ray
powder diffraction, scanning electron microscopy, elemental analysis and BET surface area measurement. The functionalized
Fe3O4 nanoparticles were used as a support to anchor metalloporphyrin. Application of immobilized metalloporphyrin as a heterogeneous
catalyst in the oxidation of cyclohexene was explored. Effect of various parameters such as solvent and temperature on immobilization
process and also various parameters (solvent, time, oxidant and axial group effect) on oxidation of cyclohexene has been investigated.
The result showed that the immobilized metalloporphyrin on functionalized magnetic nanoparticles is an efficient and reusable
catalyst for oxidation of cyclohexene. 相似文献
A novel modular experimental apparatus was designed and developed to measure and visualize fretting wear and friction for Hertzian circular and elliptical contacts and flat on flat contacts. The experimental apparatus utilizes a magnetostrictive actuator to reciprocate a flat, ball, or cylinder between two fixed specimens. Two stationary flat or cylindrical specimens mounted on a rotary table clamp the reciprocating specimen from the top and bottom to generate the fretting contact. The two stationary test specimens installed on the rotary table perpendicular to the moving specimen form a crossed cylinder geometry which creates a well-defined circular contact. An elliptical contact with different aspect ratios can be obtained by varying the angle between the fixed and the moving specimens. Dead weights placed on top of the upper stationary specimen provide the normal load. A force sensor located in line between the actuator output shaft and the specimen is used to measure friction. The test rig's modular design allows it to be configured for Hertzian circular (ball-on-flat, crossed cylinder), elliptical (crossed cylinder), and conformal (flat-on-flat) contacts. In the ball on flat configuration a steel flat or sapphire window is used in contact with the reciprocating ball. When the sapphire window is used a microscope and high speed camera is employed for in situ visualization and recording of the contact. 相似文献
Converging advances in the development of nanoparticle-based imaging probes and improved understanding of the molecular biology of brain tumors offer the potential to provide physicians with new tools for the diagnosis and treatment of these deadly diseases. However, the effectiveness of promising nanoparticle technologies is currently limited by insufficient accumulation of these contrast agents within tumors. Here a biocompatible nanoprobe composed of a poly(ethylene glycol) (PEG) coated iron oxide nanoparticle that is capable of specifically targeting glioma tumors via the surface-bound targeting peptide, chlorotoxin (CTX), is presented. The preferential accumulation of the nanoprobe within gliomas and subsequent magnetic resonance imaging (MRI) contrast enhancement are demonstrated in vitro in 9L cells and in vivo in tumors of a xenograft mouse model. TEM imaging reveals that the nanoprobes are internalized into the cytoplasm of 9L cells and histological analysis of selected tissues indicates that there are no acute toxic effects of these nanoprobes. High targeting specificity and benign biological response establish this nanoprobe as a potential platform to aid in the diagnosis and treatment of gliomas and other tumors of neuroectodermal origin. 相似文献
New functional proteomics methods are required for targeting and identification of subsets of a proteome in an activity-based fashion. Glycosidases play critical roles in biology, yet a robust method for functional analysis of their activities and identities in biological proteomes is still lacking. An aryl 2-deoxy-2-fluoro xylobioside inactivator was conjugated through cleavable and noncleavable linker arms to a biotin tag, thereby yielding two new active-site-directed reagents for activity-based profiling of retaining beta-glycanases in complex proteomes. Crucially, these tagged reagents possess high specificity for their target enzymes with kinetic parameters similar to those of the untagged reagent. Western blotting showed that these reagents bind and covalently label active retaining beta-glycanases both in pure enzyme samples and in the secreted proteome of the soil bacterium Cellulomonas fimi. Such reagents therefore show great promise for future activity-based targeting of glycanases. 相似文献
Triple-negative breast cancer is the most common and most deadly cancer among women. Radiation is a mainstay of treatment, administered after surgery, and used in the hope that any remaining cancer cells will be destroyed. While the cancer cell response is normally the focus of radiation therapy, little is known about the tumor microenvironment response after irradiation. It is widely reported that increased collagen expression and deposition are associated with cancer progression and poor prognosis in breast cancer patients. Aside from the classical fibrotic response, ratios of collagen isoforms have not been studied in a radiated tumor microenvironment. Here, we created one healthy co-culture of stromal fibroblasts and adipose-derived stem cells, and one triple-negative breast cancer co-culture, made of stromal fibroblasts, adipose derived stem cells, and triple-negative breast cancer cells. After irradiation, growth and decellularization of co-cultures, we reseeded the breast cancer cells for 24 h and analyzed the samples using mass spectrometry. Proteomic analysis revealed that collagen VI, a highly oncogenic collagen isoform linked to breast cancer, was decreased in the irradiated cancer co-culture. This indicates that the anti-cancer impact of radiation may be not only cell ablative, but also influential in creating a less oncogenic microenvironment. 相似文献
Silicon nitride (Si3N4) coating was deposited on AISI D2 tool steel through employing duplex surface treatments—pack siliconizing followed by plasma nitriding. Pack cementation was performed at 650 °C, 800 °C, and 950 °C for 2 and 3 hours by using various mixtures to realize the silicon coating. X-ray diffraction analyses and scanning electron microscopy observations were employed for demonstrating the optimal process conditions leading to high coating adhesion, uniform thickness, and composition. The optimized conditions belonging to siliconizing were employed to produce samples to be further processed via plasma nitriding. This treatment was performed with a gas mixture of 75 pct H2-25 pct N2, at the temperature of 550 °C for 7 hours. The results showed that different nitride phases such as Si3N4-β, Si3N4-γ, Fe4N, and Fe3N can be recognized as coatings reinforcements. It was demonstrated that the described composite coating procedure allowed to obtain a remarkable increase in hardness (80 pct higher with respect to the substrate) and wear resistance (30 pct decrease of weight loss) of the tool steel.
The present study reports the preparation, characterization, and investigation of properties of DNR/f-Al2O3 nanocomposites through an in situ emulsion polymerization technique. The method consists of the dispersion of pretreated nano-alumina (f-Al2O3 NPs) onto deproteinized natural rubber (DNR) latex, followed by the polymerization reaction with the K2S2O8/K2S2O5 redox initiation system, after deproteinization of natural rubber using urea in the presence of a surfactant. To improve the compatibility and reactivity of the nanofillers with DNR latex, the nano-alumina surface was treated with 3-methacryloxypropyltrimethoxysilane (MPS) to produce f-Al2O3 NPs. The thermo-gravimetric analysis (TGA) and Fourier transform infrared (FTIR) spectroscopy approved that the MPS was bound onto the surface of Al2O3 NP. The resulting nanocomposites were characterized using standard techniques for physical properties and structural morphology, including X-ray diffraction (XRD) analysis, FTIR spectroscopy, scanning electron microscopy (SEM), and TGA. The SEM images showed a homogeneous distribution of f-Al2O3 NPs throughout DNR matrix. Due to such monodisperse particles, the DNR/f-Al2O3 nanocomposite films revealed significant enhancement in thermal stability with increasing nano-alumina loading as compared with the neat DNR. 相似文献