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331.
The structural (FTIR,XRD, and XPS) and biological studies of thermosensitive chitosan chloride gels with β‐glycerophosphate disodium 下载免费PDF全文
Agata Skwarczynska Marta Kaminska Piotr Owczarz Nina Bartoszek Bogdan Walkowiak Zofia Modrzejewska 《应用聚合物科学杂志》2018,135(27)
In this article, the properties of thermosensitive chitosan hydrogels (structural and biological) prepared using chitosan chloride and β‐glycerophosphate are presented. The porous structure of the gels was observed with a scanning electron microscopy (SEM). Rheological and other structural and morphological investigations were carried out by infrared spectroscopy and X‐ray photoelectron spectroscopy. Crystallinity of the gel was determined by X‐ray diffraction analysis. Biocompatibility of the chitosan gels was investigated by contact with bone cells (line Saos‐2) for 7 and 21 days. The cells were encapsulated and seeded onto the gel. A live/dead test showed no cytotoxic reaction. The structure of the gels, before and after the cell culture, was tested using SEM (including ESEM), to select the most suitable method of preparation and reliable visualization of the gel with cells. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46459. 相似文献
332.
Battilani P Pietri VA Giorni P Formenti S Bertuzzi T Toscani T Virgili R Kozakiewicz Z 《Journal of food protection》2007,70(4):975-980
Seven ham manufacturing plants were sampled for 1 year to assess the mycoflora present in the air and on hams, with special attention given to potential mycotoxin producers. Temperature and relative humidity were recorded in the ripening rooms. Maturing rooms held hams from 2 to 3 through 6 to 7 ripening months, and aging rooms held hams for the following 6 to 7 months, until the 14-month ripening point, when they were ready for the market. Mean temperatures and relative humidities registered during the study were 14.9 degrees C and 62.4%, respectively, in maturing rooms and 16.3 degrees C and 57.6% in aging rooms. Aspergilli and penicillia, potential mycotoxin producers, were isolated in all the plants from the air and the ham. Aspergilli represented 5% of the isolates, while penicillia were largely dominant, with Penicillium nalgiovense being the most represented species (around 60% of the penicillia), followed by Penicillium nordicum, with 10 and 26% of the penicillia isolated, respectively, from the air or the ham. Ochratoxin A production ability, checked in vitro at 250C, was observed in 50% of the P. nordicum isolates obtained both from the air and the ham. Air and ham surface contamination by penicillia was greater in the ripening rooms, where higher temperatures were registered. A certain correlation was also observed between air and ham surface contamination. On the basis of this study, P. nordicum, the ochratoxin A producer that is notable on proteinaceous substrates, is normally present in ham manufacturing plants in Italy, even though not a dominant species. Further studies are necessary to clarify and ensure if dry-curing conditions minimize the potential risk of ochratoxin A formation in the product. 相似文献
333.
Ferreira R Oliveira JF Fernandes R Moraes JF Gonçalves PB 《Reproduction (Cambridge, England)》2007,134(5):713-719
There is evidence that the renin-angiotensin system plays an important role in ovulation in cattle. Using an in vivo model, we investigated the role of angiotensin (Ang) II in bovine ovulation by injecting Ang II receptor antagonists into ovulatory follicles. Animals (n = 102) were pre-synchronized and, when the follicles reached 12 mm, they were given the respective treatment and the cows received GnRH agonist (i.m.) to induce ovulation. The ovulation rate was significantly lower when 100 mu M saralasin (Ang II receptor antagonist) was intrafollicularly injected (14.3%) in comparison with saline solution (83.3%). Based on these results, a second experiment was carried out to determine the timing of Ang II's critical role in ovulation. Saralasin inhibited ovulation only when applied at 0 and 6 h (16.7 and 42.9% ovulation rate in the 0- and 6-h groups respectively), but not at 12 h (100%) following GnRH agonist treatment. To investigate the subtypes of Ang II receptors implicated in the LH-induced ovulation, losartan (LO; AT(1)-Ang II receptor antagonist), PD123 319 (AT(2)-Ang II receptor antagonist), LO+PD123 319, or saline were intrafollicularly injected when the cows were challenged with GnRH agonist. Ovulation was inhibited by PD123 319 and LO+PD123 319 (50.0 and 33.3% on ovulation rate respectively), but not by LO or saline solution (100% ovulation in both groups). From these results, we suggest that Ang II plays a pivotal role in the early mechanism of bovine ovulation via the AT(2) receptor subtype. 相似文献
334.
Reduction of acidity and removal of metal ions from coal mining effluents using chitosan microspheres 总被引:5,自引:1,他引:4
Laus R Geremias R Vasconcelos HL Laranjeira MC Fávere VT 《Journal of hazardous materials》2007,149(2):471-474
Effluents from coal mining operations are not only highly acid but also depict elevated concentrations of metals which may contaminate the environment. Due to the polybasic characteristic of chitosan, this biopolymer is capable of both neutralizing and removing iron, aluminum and copper ions from such effluents. The present study aimed at evaluating the use of chitosan microspheres for their importance in continuous systems. The microspheres were prepared by the phase inversion method. Their average diameter and morphology were determined. Water samples from decantation pool (DP) and acidic mine drainage (AMD) effluents were treated using different amounts of microspheres. The pH and concentration of Fe, Al and Cu ions were evaluated both before and after treatment of effluent samples. The results revealed that the microspheres were capable of increasing the pH of DP and AMD samples from 2.34 and 2.58, respectively, to 6.20, i.e., close to neutrality. The treatment also resulted in full removal of the metals investigated. 相似文献
335.
Shela Gorinstein Ratiporn Haruenkit Yong‐Seo Park Soon‐Teck Jung Zofia Zachwieja Zenon Jastrzebski Elena Katrich Simon Trakhtenberg Olga Martin Belloso 《Journal of the science of food and agriculture》2004,84(12):1459-1463
Bioactive compounds in the edible parts of fresh and dried Jaffa® sweeties, a new kind of citrus fruit, were analysed and their antioxidant capacities were assessed. Antioxidant‐rich fractions were extracted from fresh and dried sweeties with 1.2 M HCl in methanol/water (1:1 v/v), and the antioxidant activities of these extracts were evaluated. Using the β‐carotene/linoleate model system, the extracts from equivalent quantities of fresh and dried sweeties showed 89 and 87% antioxidant activity respectively. Similarly, using the DPPH radical‐scavenging method, the extracts showed 87 and 85% antioxidant activity respectively. The best correlations were between caffeic acid content and β‐carotene and DPPH antioxidant activity values (r = 0.9849 and 0.9798 respectively, p = 0.005). Both fresh and dried sweeties are bioactive natural products; when fresh fruits are not available, properly dried sweeties could be used as a substitute. Copyright © 2004 Society of Chemical Industry 相似文献
336.
Raquel Szygalski Biasi Renata Ernlund Freitas de Macedo Minéia Alessandra Scaranello Malaquias Paulo Rogério Franchin 《Food Control》2011,22(5):702-707
The aim of this study was to investigate the rate of contamination, species identification and antimicrobial resistance of thermophilic Campylobacter spp. in pig carcasses during the slaughter process in a slaughterhouse in Brazil. Two hundred and fifty-nine samples were collected at 7 different stages of the slaughter process for Campylobacter determination by both qualitative and quantitative methods. Typical colonies were subjected to API Campy, real-time polymerase chain reaction (PCR) and antimicrobial resistance testing. Campylobacter was found in 18.9% of the carcasses and 3.5% of the samples. Dehairing was the slaughter stage with the highest Campylobacter contamination (55.6%). All Campylobacter strains were confirmed by real-time PCR and showed multi-drug resistance to cephalothin, nalidixic acid, norfloxacin, tetracycline and trimethoprim. None of the strains were resistant to amoxicillin/clavulanic acid, ampicillin and chloramphenicol. Despite the low occurrence of Campylobacter spp. in pig samples, the antimicrobial resistance of Campylobacter strains represents a considerable risk for the consumption of pork meat and confirms the need for continuous monitoring of Campylobacter in the pig production chain. 相似文献
337.
338.
Gabriel Bonetto Bampi Geciane Toniazzo Backes Rogério Luis Cansian Fernando Eustáquio de MatosJr. Isabella Maria Araldi Ansolin Bianca Carla Poleto Larissa Rossett Corezzolla Carmem Sílvia Favaro-Trindade 《Food and Bioprocess Technology》2016,9(8):1422-1428
The use of probiotic microorganisms has been limited by the difficulty of maintaining their viability during processing and throughout the product’s shelf life. This study evaluated the viability of microencapsulating Lactobacillus acidophilus (LA) and Bifidobacterium animalis subsp. lactis (BL) using the spray chilling technique to add them to savory cereal bars. The results showed that spray chilling generated a powder that was composed of smooth and continuous spheres with low moisture content and low water activity. The microencapsulated microorganisms exhibited a storage viability at least of 90 days as microparticles and in savory cereal bars, and their counts were superior to those resulting from other methods of adding activated and lyophilized probiotics to savory cereal bars. Thus, microparticles prepared by spray chilling are good vehicles for incorporating probiotics into cereal bars and have the potential to release the probiotics in the consumers’ intestines by means of fat digestion. Savory cereal bars that did and did not contain probiotics exhibited no differences in sensorial acceptance or commercial potential. 相似文献
339.
340.
Magdalena Wjciak Martyna Zagrska-Dziok Zofia Nizio-ukaszewska Aleksandra Ziemlewska Dominika Furman-Toczek Dariusz Szczepanek Ireneusz Sowa 《International journal of molecular sciences》2022,23(22)
Cornus mas L. is a rich source of valuable compounds with pro-health properties and, therefore, may be attractive for the pharmaceutical and cosmetic industry. This paper attempts to assess the antioxidant, anti-inflammatory, and protective effect of an extract from C. mas fruit on skin cells in vitro. The phytochemical analysis of the extract was carried out using UPLC-MS and the content of the main components was determined. The biological activity of the extract was assessed by in vitro analysis using two human cell lines: keratinocytes (HaCaT) and fibroblasts (BJ). Additionally, the ability of this extract to regulate gene expression (SOD-1, Nox-4) in skin cells was evaluated. Moreover, the impact of the extract and its main components, including loganic acid and cornuside, on the level of inflammatory cytokines in H2O2-treated cells was assessed. The tests showed that the extract has strong antioxidant properties and stimulates the proliferation of both types of cells. The results evidence that the Cornus mas L. fruit extract significantly reduces the level of reactive oxygen species in the cells tested and can modulate the expression of genes closely related to oxidative stress. Moreover, it suppresses the production of IL-6, IL-8, and TNF-α, and the effect was related to loganic acid and cornuside. The present research indicates that the analyzed dogwood extract can be an effective means of prevention of cell damage caused by free radicals and have a positive effect on the condition of skin cells. 相似文献