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1
Thongzai, Hataikan, Narumol Matan, Palanivel Ganesan, and Tanong Aewsiri. "Interfacial Properties and Antioxidant Activity of Whey Protein-Phenolic Complexes: Effect of Phenolic Type and Concentration." Applied Sciences 12, no. 6 (March 12, 2022): 2916. http://dx.doi.org/10.3390/app12062916.
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Whey protein is a common food additive for enhancing product stability and texture, while phenolics are considered food antioxidants. As a consequence, combining whey protein with phenolics is an effective way to improve protein functionality while also maintaining polyphenol bioactivity. Herein, the functional properties and antioxidant activity of whey protein modified with various types and concentrations of oxidized phenolic compounds, including gallic acid (OGA), ferulic acid (OFA), and tannic acid (OTA), were studied. In general, the modified whey protein had a decrease in free amino content, but an increase in total phenolic content. Whey protein modified with 5% OTA showed the highest total phenolic content and the lowest free amino content. Modification of whey protein with OTA and OGA resulted in a loss of surface hydrophobicity in contrast to whey protein modified with OFA. However, no significant difference in surface activity including foam and emulsion properties in the whey protein with/without modification was observed. The modified whey protein had an increase in antioxidant activity when compared with that of the control.
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Lee, Hyun Jung, Shufang Li, Kejia Gu, and Dojin Ryu. "Reduction of Ochratoxin A during the Preparation of Porridge with Sodium Bicarbonate and Fructose." Toxins 13, no. 3 (March 19, 2021): 224. http://dx.doi.org/10.3390/toxins13030224.
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Ochratoxin A (OTA) is a potential human carcinogen that poses a significant concern in food safety and public health. OTA has been found in a wide variety of agricultural commodities, including cereal grains. This study investigated the reduction of OTA during the preparation of rice- and oat-based porridge by a simulated indirect steam process. The effects of sodium bicarbonate (NaHCO3) and fructose on the reduction of OTA were also investigated. During the processing, OTA in rice- and oat-porridge was decreased by 59% and 14%, respectively, from initial OTA artificially added at 20 μg/kg (dry weight basis). When 0.5% and 1% of sodium bicarbonate were added to rice porridge, increased reduction of OTA was observed as 78% and 68%, respectively. The same amounts of added sodium bicarbonate also further reduced OTA in oat porridge to 58% and 72%, respectively. In addition, increased reduction of OTA in the presence of fructose was observed. A combination of the two, i.e., 0.5% sodium bicarbonate and 0.5% fructose, resulted in a 79% and 67% reduction in rice porridge and oat porridge, respectively. These results indicate that indirect steaming may effectively reduce OTA in preparation of porridge-type products, particularly when sodium bicarbonate and/or fructose are added.
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Wang, Yaosong, and Youling L. Xiong. "Physicochemical and Microstructural Characterization of Whey Protein Films Formed with Oxidized Ferulic/Tannic Acids." Foods 10, no. 7 (July 9, 2021): 1599. http://dx.doi.org/10.3390/foods10071599.
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Protein-based biodegradable packaging films are of environmental significance. The effect of oxidized ferulic acid (OFA)/tannic acid (OTA) on the crosslinking and film-forming properties of whey protein isolate (WPI) was investigated. Both of the oxidized acids induced protein oxidation and promoted WPI crosslinking through the actions of quinone carbonyl and protein sulfhydryl, and amino groups. OTA enhanced the tensile strength (from 4.5 MPa to max 6.7 MPa) and stiffness (from 215 MPa to max 376 MPa) of the WPI film, whereas OFA significantly increased the elongation at break. The water absorption capability and heat resistance of the films were greatly improved by the addition of OTA. Due to the original color of OTA, the incorporation of OTA significantly reduced light transmittance of the WPI film (λ 200–600 nm) as well as the transparency, whereas no significant changes were induced by the OFA treatment. Higher concentrations of OTA reduced the in vitro digestibility of the WPI film, while the addition of OFA had no significant effect. Overall, these two oxidized polyphenols promoted the crosslinking of WPI and modified the film properties, with OTA showing an overall stronger efficacy than OFA due to more functional groups available.
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DHUNGANA, BANDANA, SHAUKAT ALI, EMMANUEL BYAMUKAMA, PADMANABAN KRISHNAN, and MELANIE CAFFE-TREML. "Incidence of Penicillium verrucosum in Grain Samples from Oat Varieties Commonly Grown in South Dakota." Journal of Food Protection 81, no. 6 (May 3, 2018): 898–902. http://dx.doi.org/10.4315/0362-028x.jfp-17-386.
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ABSTRACT Ochratoxin A (OTA) can cause toxicogenic effects in humans and animals when contaminated food products are consumed. Oat (Avena sativa), like any other cereal grain, can be contaminated with OTA when storage conditions are favorable for fungal growth and toxin production. South Dakota is among the leading oat-producing states in the United States. It is therefore important to determine the frequency of occurrence of the primary OTA-producing fungal species on oat grains produced in the state. In this study, we evaluated oat grain samples from South Dakota for the incidence of Penicillium verrucosum, the major ochratoxigenic fungus in temperate regions. Kernels from 12 oat cultivars grown at multiple locations in South Dakota from 2014 to 2016 (15 location-year combinations) were plated on dichloran yeast extract sucrose glycerol agar medium. P. verrucosum was detected on 0.30, 0.19, and 0.05% of the kernels tested in 2014, 2015, and 2016, respectively. Overall, 22 of the 360 evaluated samples had kernels contaminated with P. verrucosum. The fungal incidence of the contaminated samples ranged from 1 to 16%, and the majority of those samples originated from one location. All samples from 2014 and 2015 (n = 240), except two, had no detectable levels of OTA. The concentration of OTA was well under the maximum limit recommended by the European Union for the two samples with detectable levels of OTA.
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Cappozzo, Jack, Lauren Jackson, Hyun Jung Lee, Wei Zhou, Fadwa Al-Taher, Jerry Zweigenbaum, and Dojin Ryu. "Occurrence of Ochratoxin A in Infant Foods in the United States." Journal of Food Protection 80, no. 2 (January 23, 2017): 251–56. http://dx.doi.org/10.4315/0362-028x.jfp-16-339.
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ABSTRACTOchratoxin A (OTA) is a possible human carcinogen and occurs frequently in cereal grain, soy, and other agricultural commodities. Infants and young children may be more susceptible to contaminants than adults because of their lower body weight, higher metabolic rate, reduced ability to detoxify food toxicants, and more restricted diet. The purpose of this study was to investigate the occurrence and levels of OTA in infant formula and infant cereal products available in the U.S. market. In the present study, 98 powdered infant formula (milk- and soy-based) samples and 155 infant cereal (barley-, rice-, oat-, wheat-, and mixed grain–based) products were collected from different retail locations in the United States over a 2-year period. OTA levels were determined by liquid chromatography–tandem mass spectrometry. Although OTA was not detected in any of the infant formula samples, 47 (30%) of 155 infant cereals were contaminated with OTA in the range of 0.6 to 22.1 ng/g. At present, there is no regulatory limit for OTA in the United States. However, all of the positive samples were above the maximum level set by the European Commission (0.5 ng/g) for OTA in baby foods. OTA was detected in all types of infant cereals, but the highest incidence and concentrations were found in oat-based infant cereals (59%), followed by mixed grain cereals (34%). Increased surveillance and monitoring of OTA levels in grains used in infant foods may be needed to reduce exposure of infants and young children to OTA from cereal products.
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Nguyen, Kieu Thi Ngoc, and Dojin Ryu. "Ultrasonic Extraction with Ultra-Performance Liquid Chromatography/Tandem Mass Spectrometry for the Determination of Ochratoxin A in Processed Cereal Products." Journal of AOAC INTERNATIONAL 97, no. 5 (September 1, 2014): 1384–86. http://dx.doi.org/10.5740/jaoacint.13-425.
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Abstract A rapid, simple, and reliable method using ultra-performance LC/MS/MS (UPLC/MS/MS) was developed for determination of ochratoxin A (OTA) in processed cereal products. OTA was ultrasonically extracted from the sample with acetonitrile–water (80 + 20, v/v), and the extract was then injected into the UPLC/MS/MS system after filtration. The calibration curves had good linearity with coefficients of determination greater than 0.999. Recoveries of OTA were in the range of 90–104%. LOD and LOQ of OTA in samples were 0.6 and 2.0 ng/g, respectively, and no significant matrix effect was found. This method was applied to determine OTA in 25 oat-based cereal samples. OTA was detected in five samples (20%) in the range of 2.4 to 7.3 ng/g.
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Lee, Hyun Jung, Samjhana Dahal, Enrique Garcia Perez, Ryan Joseph Kowalski, Girish M. Ganjyal, and Dojin Ryu. "Reduction of Ochratoxin A in Oat Flakes by Twin-Screw Extrusion Processing." Journal of Food Protection 80, no. 10 (August 30, 2017): 1628–34. http://dx.doi.org/10.4315/0362-028x.jfp-16-559.
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ABSTRACT Ochratoxin A (OTA) is one of the most important mycotoxins owing to its widespread occurrence and toxicity, including nephrotoxicity and potential carcinogenicity to humans. OTA has been detected in a wide range of agricultural commodities, including cereal grains and their processed products. In particular, oat-based products show a higher incidence and level of contamination. Extrusion cooking is widely used in the manufacturing of breakfast cereals and snacks and may reduce mycotoxins to varying degrees. Hence, the effects of extrusion cooking on the stability of OTA in spiked (100 μg/kg) oat flake was investigated by using a laboratory-scale twin-screw extruder with a central composite design. Factors examined were moisture content (20, 25, and 30% dry weight basis), temperature (140, 160, and 180°C), screw speed (150, 200, and 250 rpm), and die size (1.5, 2, and 3 mm). Both nonextruded and extruded samples were analyzed for reductions of OTA by high-performance liquid chromatography, coupled with fluorescence detection. The percentage of reductions in OTA in the contaminated oat flakes upon extrusion processing were in the range of 0 to 28%. OTA was partially stable during extrusion, with only screw speed and die size having significant effect on reduction (P < 0.005). The highest reduction of 28% was achieved at 180°C, 20% moisture, 250 rpm screw speed, and a 3-mm die with 193 kJ/kg specific mechanical energy. According to the central composite design analyses, up to 28% of OTA can be reduced by a combination of 162°C, 30% moisture, and 221 rpm, with a 3-mm die.
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Boltaeva, Mokhichekhra, and Olimjon Ortikov. "Sharq mutafakkirlarining ota – onalarning bolaga munosabatiga oid ilmiy merosining o‘ziga hos jihatlari." Общество и инновации 2, no. 2/S (March 27, 2021): 470–74. http://dx.doi.org/10.47689/2181-1415-vol2-iss2/s-pp481-486.
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Mazkur maqolada oilada ota-ona va bolaning o‘zaro munosabatlari xaqida ko‘rib chiqilgan. Maqolada bola tarbiyasida Sharq mutafakkirlarning o‘z asarlaridagi qimmatbaho fikrlari va ularning xozirgi kundagi ota-onalarning farzand tarbiyasida aynan qaysi jihatlarga e’tibor qaratish kerakligi kabi masalalar tavsiflanadi.
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Komilova, Aziza. "Роль родителей в подготовке молодежи к семейной жизни." Общество и инновации 2, no. 10/S (December 9, 2021): 437–41. http://dx.doi.org/10.47689/2181-1415-vol2-iss10/s-pp437-441.
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Ushbu maqolada oilaviy hayotga kattalarni va yoshlarni o‘rgatish, ularda sog‘lom munosabatlar psixologiyasini shakllantirish, ota-onadagi madaniyat, ma’naviyat, iste’dod, mas’uliyatning o‘g‘il-qizlarda namoyon bo‘lishi, bolalardagi o‘zgarish, intilish, qiziqish ota-ona tomonidan nazorat qilinishi, oilada bola shaxsini shakllantirish, ularni oilaviy hayotga tayyorlash bo‘yicha ma’lumotlar berilgan.
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Ferrara, Massimo, Giancarlo Perrone, Lucia Gambacorta, Filomena Epifani, Michele Solfrizzo, and Antonia Gallo. "Identification of a Halogenase Involved in the Biosynthesis of Ochratoxin A in Aspergillus carbonarius." Applied and Environmental Microbiology 82, no. 18 (July 15, 2016): 5631–41. http://dx.doi.org/10.1128/aem.01209-16.
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ABSTRACTAspergillus carbonariusis the main responsible fungus of ochratoxin A (OTA) contamination of grapes and derived products. To date, the biosynthetic mechanism of this mycotoxin has been partially elucidated. Availability of genome sequence ofA. carbonariushas allowed the identification of a putative gene cluster involved in OTA biosynthesis. This region hosts the previously characterizedAcOTAnrpsandAcOTApksgenes encoding two key enzymes of the biosynthetic pathway. At about 4,400 nucleotides downstream of these loci, a gene encoding a putative flavin dependent-halogenase came out from the annotation data. Its proximity to OTA biosynthetic genes and its sequence analysis have suggested a role in the biosynthesis of OTA, directed to the introduction of the chlorine atom in the C-5 position of the final molecular structure of this mycotoxin. The deduced protein sequence of the halogenase gene, we designatedAcOTAhal, shows a high similarity to a halogenase that is located in the OTA cluster ofA. niger. The deletion of the halogenase gene completely eliminated the production of ochratoxin A inA. carbonariusand determined a significant increase of ochratoxin B, as confirmed by mass spectrometry analysis. Moreover, its expression profile was similar to the two biosynthetic genes previously identified,AcOTApksandAcOTAnrps, indicating a strong correlation of theAcOTAhalgene with the kinetics of OTA accumulation inA. carbonarius.Therefore, experimental evidence confirmed that the chlorination step which converts OTB in OTA represents the final stage of the biosynthetic pathway, supporting our earlier hypothesis on the order of enzymatic steps of OTA biosynthesis inA. carbonarius.IMPORTANCEOchratoxin A is a potent mycotoxin classified as a possible carcinogen for humans, andAspergillus carbonariusis the main agent responsible for OTA accumulation in grapes. We demonstrate here that a flavin-halogenase is implicated in the biosynthesis of OTA inA. carbonarius. The encoding gene,AcOTAhal, is contiguous to biosynthetic genes that we have already described (nrpsandpks), resulting as part of the biosynthetic cluster. The encoded protein is responsible of the introduction of chlorine atom in the final molecular structure and acts at the last step in the pathway. This study can be considered a continuation of an earlier study wherein we started to clarify the molecular basis of OTA biosynthesis inA. carbonarius, which has not been completely elucidated until now. This research represents an important step forward to a better understanding of the production mechanism, which will contribute to the development of improved control strategies to reduce the risk of OTA contamination in food products.
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Li, Jiang, Lu Gao, Zhirong Wang, Peiwen Huang, Tianzhu Guan, and Xiangfeng Zheng. "Mechanistic insight into ochratoxin A adsorption onto the cell wall of Lacticaseibacillus rhamnosus Bm01 and its impact on grape juice quality." Quality Assurance and Safety of Crops & Foods 16, no. 2 (July 4, 2024): 52–64. http://dx.doi.org/10.15586/qas.v16i2.1486.
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The contamination of food products with ochratoxin A (OTA) is a significant and pervasive food safety concern. In this regard, the novel use of lactic acid bacteria (LAB) to eliminate OTA from food has shown strong potential. The adsorption of OTA to the Lacticaseibacillus rhamnosus Bm01 (Bm01) cell walls has been demonstrated to eliminate OTA from grape juice effectively. The present study investigated the specific components of the Bm01 cell wall on OTA adsorption and evaluated the effect of Bm01 on grape juice quality using high-performance liquid chromatography. The results showed that the treatment of methanol and formaldehyde caused cell membrane perforation and enhanced OTA adsorption of Bm01, which reduced 98.35% and 95.13% of OAT, respectively. The involvement of cell wall proteins in the adsorption of OTA was demonstrated because only 5.23% of OTA was removed by Bm01 without cell wall proteins. Lactic (from 0 to 1.69 mg/mL) and acetic acid levels (from 0.14 to 1.45 mg/mL) were increased, malic acid (from1.24 to 0.81 mg/mL), glucose (from 8.8 to 6.91 mg/mL), and fructose (from 12.73 to 7.47 mg/mL) levels were reduced after treatment with Bm01. The addition of Bm01 shows little negative impact on color and light transmission. Overall, the effect of the addition of Bm01 on the quality of grape juice was found to be minimal. These results indicate that Bm01 has the potential to be a viable biological solution for mitigating OTA contamination in beverages, thereby offering a practical and effective method for food safety.
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Wu, F., T. Bui-Klimke, and K. Naumoff Shields. "Potential economic and health impacts of ochratoxin A regulatory standards." World Mycotoxin Journal 7, no. 3 (January 1, 2014): 387–98. http://dx.doi.org/10.3920/wmj2013.1686.
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Ochratoxin A (OTA) is a mycotoxin found in multiple agricultural commodities worldwide. OTA causes renal toxicity in certain animal species, but there is little documented evidence of adverse health effects in humans. Until recently, few nations have established regulations on maximum levels for OTA in commodities. The application of regulations may cause economic loss to food producers, which should be considered alongside potential health benefits from enacting such regulations. We evaluate the potential economic impacts of the recently proposed OTA maximum limits (MLs) for foodstuffs by Health Canada. Potential costs to Canadian food producers and nations exporting to Canada are estimated using data on reported proportion of foodstuffs exceeding OTA ML levels, and market data from the Canadian Importer's Database and the United States Department of Agriculture Global Agricultural Trade System. If the proposed OTA MLs are enforced, estimated annual losses to Canadian food producers could exceed 260 million Canadian dollars (CD), based on proportion of products expected to have OTA levels exceeding the MLs. Wheat and oat producers would experience the greatest proportion of economic loss. The United States is the largest exporter to Canada of foods that would be subject to the proposed MLs, and would experience an estimated annual loss of over 17 million CD; primarily in the infant food, breakfast cereal and raisin industries. The countervailing health benefits of such OTA standards are unclear. These potential health and economic implications should be considered by policymakers when setting regulatory standards on food safety.
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Whitaker, T. B., A. B. Slate, T. W. Nowicki, and F. G. Giesbrecht. "Variability and distribution among sample test results when sampling unprocessed oat lots for ochratoxin A." World Mycotoxin Journal 8, no. 4 (August 17, 2015): 511–24. http://dx.doi.org/10.3920/wmj2014.1858.
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In 2008, Health Canada announced it was considering the establishment of maximum levels for ochratoxin A (OTA) in a number of foods, including unprocessed wheat and oats and their products. The Canada Grains Council and Canadian National Millers Association initiated a study to measure the variability and distribution among sample test results so that scientifically based sampling plans could be designed to meet regulatory and industry requirements. Twenty lots of oats naturally contaminated with OTA were identified and sampled according to a nested experimental protocol where 16-two kg laboratory samples were taken from each lot, two 100 g test portions were taken from each comminuted laboratory sample, and two aliquots of the extract from each test portion were analysed for OTA by LC. The variance associated with each step of the OTA test procedure were found to be a function of OTA concentration and regression equations were developed to predict the functional relationship. When using the above OTA test procedure on an oat lot at 5 μg/kg, the sampling, sample preparation, analytical, and total variances were 11.26, 0.10, 0.13 and 11.49, respectively. The 2 kg sampling step accounted for 98.0% (11.26/11.49) of the total variability. The observed OTA distribution among the 16 OTA sample results was found to be positively skewed and the negative binomial distribution was selected to model the OTA distribution among sample test results. The sampling statistics were incorporated into the FAO Mycotoxin Sampling Tool where operating characteristic curves were calculated to predict the chances of rejecting good lots (seller’s risk) and accepting bad lots (buyer’s risk) for various sampling plan designs.
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Hu, Yang, Hanyin Xie, Jiaying Hu, and Danting Yang. "Disposable Electrochemical Aptasensor Based on Graphene Oxide-DNA Complex as Signal Amplifier towards Ultrasensitive Detection of Ochratoxin A." Micromachines 13, no. 6 (May 26, 2022): 834. http://dx.doi.org/10.3390/mi13060834.
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Signal amplification is crucial in developing a reliable disposable screen-printed carbon electrodes (SPCEs)-based biosensor for analyte detection with a narrow detection window. This work demonstrated a novel label-free electrochemical aptasensor based on SPCEs for the ultrasensitive detection of ochratoxin A (OTA). The graphene oxide-DNA (GO-DNA) complex as a signal amplifier with easy preparation was investigated for the first time. The proposed aptasensor based on the SPCEs/GO/cDNA-aptamer/3D-rGO-AuNPs structure was formed through the hybridization of aptamer-linked 3D-rGO/AuNPs and its complementary DNA-linked GO (GO-cDNA). The presence of OTA was discerned by its specific aptamer forming a curled OTA-aptamer complex and releasing the GO-cDNA from the surface of SPCEs. The resulting OTA-aptamer complex hindered interfacial electron transfer on the sensing surface, leading to the decreased peak current. The GO-cDNA further amplified the peak current change. This electrochemical aptasensor showed a low limit of detection of 5 fg/mL as well as good reproducibility with the relative standard deviation (RSD) of 4.38%. Moreover, the detection result of OTA in the rice and oat samples was comparable with that of the enzyme-linked immunosorbent assay (ELISA) kit. In general, the OTA aptasensor used in this work with convenient preparation, low-cost, good selectivity, high sensitivity and acceptable reproducibility can be proposed as a reliable point-of-care (POC) technique for OTA determination.
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NAWA, Kotaro. "The OTA Legacy." Journal of Information Processing and Management 55, no. 4 (2012): 285–87. http://dx.doi.org/10.1241/johokanri.55.285.
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Faisal, Zelma, Diána Derdák, Beáta Lemli, Sándor Kunsági-Máté, Mónika Bálint, Csaba Hetényi, Rita Csepregi, et al. "Interaction of 2′R-ochratoxin A with Serum Albumins: Binding Site, Effects of Site Markers, Thermodynamics, Species Differences of Albumin-binding, and Influence of Albumin on Its Toxicity in MDCK Cells." Toxins 10, no. 9 (September 1, 2018): 353. http://dx.doi.org/10.3390/toxins10090353.
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Ochratoxin A (OTA) is a nephrotoxic mycotoxin. Roasting of OTA-contaminated coffee results in the formation of 2′R-ochratoxin A (2′R-OTA), which appears in the blood of coffee drinkers. Human serum albumin (HSA) binds 2′R-OTA (and OTA) with high affinity; therefore, albumin may influence the tissue uptake and elimination of ochratoxins. We aimed to investigate the binding site of 2′R-OTA (verses OTA) in HSA and the displacing effects of site markers to explore which molecules can interfere with its albumin-binding. Affinity of 2′R-OTA toward albumins from various species (human, bovine, porcine and rat) was tested to evaluate the interspecies differences regarding 2′R-OTA-albumin interaction. Thermodynamic studies were performed to give a deeper insight into the molecular background of the complex formation. Besides fluorescence spectroscopic and modeling studies, effects of HSA, and fetal bovine serum on the cytotoxicity of 2′R-OTA and OTA were tested in MDCK kidney cell line in order to demonstrate the influence of albumin-binding on the cellular uptake of ochratoxins. Site markers displaced more effectively 2′R-OTA than OTA from HSA. Fluorescence and binding constants of 2′R-OTA-albumin and OTA-albumin complexes showed different tendencies. Albumin significantly decreased the cytotoxicity of ochratoxins. 2′R-OTA, even at sub-toxic concentrations, increased the toxic action of OTA.
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K Sulaymanova, D. "BOLАLАRNI MUQOBIL PАRVАRISH QILISH MUАSSАSАLАRI TАRBIYALАNUVCHILАRINING IJTIMOIY АDАPTАTSIYA JАRАYONIDАGI MUАMMOLАR VA ULARNING YECHIMLARI." 2022-yil, 3-son (133/1) ANIQ FANLAR SERIYASI 2, no. 132/2 (March 2, 2022): 1–8. http://dx.doi.org/10.59251/2181-1296.v2.1322.53.
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Maqolada yetim va ota-ona qaramogʼidan mahrum boʼlgan bolalarning ijtimoiy adaptatsiya jarayonida yuzaga keladigan hamda kelishi mumkin boʼlgan muammolar hamda ularni bartaraf etish choralari yoritilgan.
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Sueck, Franziska, Vanessa Hemp, Jonas Specht, Olga Torres, Benedikt Cramer, and Hans-Ulrich Humpf. "Occurrence of the Ochratoxin A Degradation Product 2′R-Ochratoxin A in Coffee and Other Food: An Update." Toxins 11, no. 6 (June 8, 2019): 329. http://dx.doi.org/10.3390/toxins11060329.
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Food raw materials can contain the mycotoxin ochratoxin A (OTA). Thermal processing of these materials may result in decreased OTA levels but also in the formation of the thermal isomerization product 2′R-ochratoxin A (2′R-OTA). So far, only 2′R-OTA levels reported from 15 coffee samples in 2008 are known, which is little when compared to the importance of coffee as a food and trading good. Herein, we present results from a set of model experiments studying the effect of temperatures between 120 °C and 270 °C on the isomerization of OTA to 2′R-OTA. It is shown that isomerization of OTA starts at temperatures as low as 120 °C. At 210 °C and above, the formation of 25% 2′R-OTA is observed in less than one minute. Furthermore, 51 coffee samples from France, Germany, and Guatemala were analyzed by HPLC-MS/MS for the presence of OTA and 2′R-OTA. OTA was quantified in 96% of the samples, while 2′R-OTA was quantifiable in 35% of the samples. The highest OTA and 2′R-OTA levels of 28.4 µg/kg and 3.9 µg/kg, respectively, were detected in coffee from Guatemala. The OTA:2′R-OTA ratio in the samples ranged between 2.5:1 and 10:1 and was on average 5.5:1. Besides coffee, 2′R-OTA was also for the first time detected in a bread sample and malt coffee powder.
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Guo, Wei, Haoyu Yang, Yunzhe Zhang, Hao Wu, Xin Lu, Jianxin Tan, and Wei Zhang. "A Novel Fluorescent Aptasensor Based on Real-Time Fluorescence and Strand Displacement Amplification for the Detection of Ochratoxin A." Foods 11, no. 16 (August 13, 2022): 2443. http://dx.doi.org/10.3390/foods11162443.
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It is urgently necessary to develop convenient, reliable, ultrasensitive and specific methods of ochratoxin A determination in food safety owing to its high toxicity. In the present study, an ultrasensitive and labeled-free fluorescent aptamer sensor combining real-time fluorescence with strand displacement amplification (SDA) was fabricated for the determination of OTA. In the presence of OTA, the OTA–aptamer combines with OTA, thus opening hairpins. Then, SDA primers specifically bind to the hairpin stem, which is used for subsequent amplification as a template. SDA amplification is initiated under the action of Bst DNA polymerase and nicking endonuclease. The amplified products (ssDNA) are dyed with SYBR Green II and detected with real-time fluorescence. The method has good linearity in the range of 0.01–50 ng mL−1, with the lowest limit of detection of 0.01 ng mL−1. Additionally, the fluorescent aptamer sensor shows outstanding specificity and reproducibility. Furthermore, the sensor shows excellent analytical performance in the artificial labeled detection of wheat and oat samples, with a recovery rate of 96.1~100%. The results suggest that the developed sensor has a promising potential application for the ultrasensitive detection of contaminants in food.
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Toni, Andressa. "‘Ota bruxa?’." Cadernos de Estudos Linguísticos 64 (September 30, 2022): e022025. http://dx.doi.org/10.20396/cel.v64i00.8668890.
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Esta pesquisa revisita a aquisição das sílabas de ataque ramificado CCV (Consoante1+Consoante2+Vogal) em Português Brasileiro, investigando como o molde silábico é categorizado ao longo do desenvolvimento fonológico infantil e por que este desenvolvimento ocorre da forma que ocorre. Para caracterizar o alvo sendo adquirido, um estudo de corpus descreve a variação CCV→CV presente na fala de adultos paulistanos (como em ‘outro’→[ʹo.tʊ]) utilizando dados do Projeto SP2010 (MENDES, 2013). Já para caracterizar o desenvolvimento infantil, conduzimos um experimento de produção e compreensão de fala (mispronunciation detection task). Como arcabouço teórico, o Princípio da Tolerância (YANG, 2016) modela a construção do contraste entre as estruturas CCV-CV, estabelecido com base no adensamento fonológico do Léxico (JUSCZYK, LUCE & LUCE, 1994). O estudo constata que, ao adquirir CCV, a criança adquire uma sílaba fonologicamente pouco densa, foneticamente variável e suscetível a processos de neutralização do contraste CCV-CV. Defendemos que tais características do input levam a uma incorreta generalização de CCV como opcional, tomando CV como uma forma alternante – tanto em contextos átonos (o que é encontrado na fala adulta) como em contextos tônicos (que não ocorre na fala adulta paulistana). A produtividade desta hipergeneralização é capturada pelo Princípio da Tolerância e decorre da alta concentração de CCVs reduzíveis no vocabulário inicial da criança, sendo superada com o crescimento lexical. A hipergeneralização da variação CCV~CV reflete-se no teste de detecção de erros apontando reconhecimento de CV→CCV (‘dente’→‘d[ɾ]ente’), mas não de CCV→CV (‘prato’→’pato’, ‘preto’→’peto’) por crianças que simplificam CCV em sua fala. A maior taxa de detecção de vizinhos CCV-CV no teste (‘prato’→‘pato’ é mais detectado que ‘preto’→‘peto’) aponta a construção do contraste como um ponto-chave no desenvolvimento fonológico. Com isso, argumentamos que a aquisição CCV passa por um momento de incorreta neutralização do contraste estrutural da sílaba.
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SHIRAISHI, Yoichi. "OTA Report." IEICE ESS FUNDAMENTALS REVIEW 5, no. 2 (2011): 185–86. http://dx.doi.org/10.1587/essfr.5.185.
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Schemitsch, Emil H. "OTA International." OTA International 1, no. 1 (May 2018): e000. http://dx.doi.org/10.1097/oi9.0000000000000000.
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PARK, JE WON, SOO-HYUN CHUNG, CHAN LEE, and YOUNG-BAE KIM. "Fate of Ochratoxin A during Cooking of Naturally Contaminated Polished Rice." Journal of Food Protection 68, no. 10 (October 1, 2005): 2107–11. http://dx.doi.org/10.4315/0362-028x-68.10.2107.
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Ochratoxin A (OTA), a mycotoxin widespread in cereals, occurs in polished rice that is consumed as cooked rice after washing and steaming. Cooking decreases OTA levels in food to varying extents, but little is known about how cooking changes the biological activity of this mycotoxin. We therefore evaluated the fate of OTA during rice cooking to determine the OTA residues and cytotoxic potential in vitro. Water-washed rice, ordinary cooked rice, and pressure-cooked rice were prepared from three polished rice lots naturally contaminated with OTA. Residual OTA in each sample was analyzed by high-performance liquid chromatography (HPLC), whereas in vitro cytotoxicity of OTA to C6 glioma cells, susceptible to low levels (nanograms per milliliter) of OTA, was used to confirm the chemical analysis. OTA concentration, as determined by HPLC analysis, in the cooked rice by both types of cookers was significantly lower than (59 to 75%) in the raw polished rice and water-washed rice. The cytotoxicity of the OTA that remained in the pressure-cooked rice from three lots was markedly decreased (approximately 20%, P < 0.05) when compared with other samples in respective lots. This confirms that cooking lowers OTA residues. Although washing polished rice with water had little effect on OTA levels, pressure steaming appeared to be the critical cooking step not only to reduce OTA residues in polished rice before reaching the consumer as the dietary staple of cooked rice, but also to diminish cytotoxicity of OTA.
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Delibas, Namik, Irfan Altuntas, Zafer Yonden, and Nurten Ozcelik. "Ochratoxin a reduces NMDA receptor subunits 2A and 2B concentrations in rat hippocampus: partial protective effect of melatonin." Human & Experimental Toxicology 22, no. 6 (June 2003): 335–39. http://dx.doi.org/10.1191/0960327103ht357oa.
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Ochratoxin A (OTA) is a mycotoxin produced by several fungi. Many foods can be contaminated by OTA, which is consequently found in the blood of humans and animals. It is known that OTA accumulates in the brain. The aim of this study was to investigate the effects of OTA on the brain. For this purpose, the effect of OTA on N-methyl-Daspartate (NMDA) receptor subunits 2A (NR2A) and 2B (NR2B) in the hippocampus and the protective effect of melatonin were investigated. Three groups of eight rats were used: controls, OTA-treated rats (OTA dose 289 mg/ kg per day) and OTA-melatonin-treated rats (melatonin dose 10 mg/kg per day). After four weeks of treatment, electrophoretic examinations were performed using SDSpolyacrylamide gel electrophoresis and Western blotting of hippocampal homogenates of the different groups. The concentrations of NR2A and NR2B in the OTA group were significantly lower than in the control group. The concentration of NR2B was significantly increased when melatonin was co-administered with OTA compared with OTA only. There was also a significant increase in NR2A levels when melatonin was co-administered with OTA. As a result, subchronic administration of OTA reduced hippocampal NMDA receptor subunits 2A and 2B concentrations in rats. It was thought that this alteration might affect cognitive functions because hippocampal NMDA receptors are involved in the memory and learning processes. Melatonin exhibited a partially protective effect on NR2A and NR2B against OTA.
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Sutken, Emine, Erinc Aral, Filiz Ozdemir, Sema Uslu, Ozkan Alatas, and Omer Colak. "Protective Role of Melatonin and Coenzyme Q10 in Ochratoxin A Toxicity in Rat Liver and Kidney." International Journal of Toxicology 26, no. 1 (January 2007): 81–87. http://dx.doi.org/10.1080/10915810601122893.
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Melatonin (MEL) and coenzyme Q10 (CoQ10) both display antioxidant and free radical scavenger properties. In the present study, the effect of MEL and CoQ10 on the oxidative stress and fibrosis induced by ochratoxin A (OTA) administration in rats was investigated. Rats were divided into five equal groups, each consisting of seven rats: (1) controls; (2) OTA-treated rats (289 μg/kg/day); (3) OTA+MEL–treated rats (289 μg/kg/day OTA + 10 mg/kg/day MEL); and (4) OTA+CoQ10–treated rats (289 μg/kg/day OTA +1 mg/100 g/day body weight (bw) CoQ10). After 4 weeks of treatment, the level of malondialdehyde (MDA), glutathione peroxidase (GPx), and hydroxyproline (Hyp) were measured in the homogenates of liver and kidney. In the OTA-treated group, the levels of MDA and Hyp in both liver and kidney were significantly increased when compared with the levels of control, whereas GPx activities decreased. In OTA+MEL–treated rats, the levels of MDA and Hyp in both liver and kidney were significantly decreased when compared with the levels of OTA-treated rats; however; GPX activities increased. In the OTA+CoQ10–treated group, the levels of MDA and Hyp were decreased when compared with the levels of OTA-treated rats, whereas GPx activities increased. In the OTA+CoQ 10–treated group, the levels of MDA, Hyp, and GPx were not significantly changed in kidney when compared with OTA-treated group. MEL has a protective effect against OTA toxicity through an inhibition of the oxidative damage and fibrosis both liver and kidney. Although CoQ10 has protective effect against OTA toxicity in liver tissue, it has no effect in kidney tissue.
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Vartiainen, Suvi, Alexandros Yiannikouris, Juha Apajalahti, and Colm A. Moran. "Comprehensive Evaluation of the Efficiency of Yeast Cell Wall Extract to Adsorb Ochratoxin A and Mitigate Accumulation of the Toxin in Broiler Chickens." Toxins 12, no. 1 (January 7, 2020): 37. http://dx.doi.org/10.3390/toxins12010037.
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Ochratoxin A (OTA) is a common mycotoxin contaminant in animal feed. When absorbed from the gastrointestinal tract, OTA has a propensity for pathological effects on animal health and deposition in animal tissues. In this study, the potential of yeast cell wall extracts (YCWE) to adsorb OTA was evaluated using an in vitro method in which consecutive animal digestion events were simulated. Low pH markedly increased OTA binding to YCWE, which was reversed with a pH increased to 6.5. Overall, in vitro analysis revealed that 30% of OTA was adsorbed to YCWE. Additional computational molecular modelling revealed that change in pH alters the OTA charge and modulates the interaction with the YCWE β-d-glucans. The effectiveness of YCWE was tested in a 14-day broiler chicken trial. Birds were subjected to five dietary treatments; with and without OTA, and OTA combined with YCWE at three dosages. At the end of the trial, liver OTA deposition was evaluated. Data showed a decrease of up to 30% in OTA deposits in the liver of broilers fed both OTA and YCWE. In the case of OTA, a tight correlation between the mitigation efficacy of YCWE between in vitro and in vivo model could be observed.
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HWANG, CHENG-AN, and FRANCES A. DRAUGHON. "Degradation of Ochratoxin A by Acinetobacter calcoaceticus." Journal of Food Protection 57, no. 5 (May 1, 1994): 410–14. http://dx.doi.org/10.4315/0362-028x-57.5.410.
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Microorganisms were screened for their ability to degrade ochratoxin A (OTA). Among test microorganisms, Acinetobacter calcoaceticus was found to degrade OTA. The degradation of OTA by A. calcoaceticus was studied in an ethanol-minimal salts medium with an initial OTA concentration of 10 (μg/ml at 25 and 30°C. Under these conditions, A. calcoaceticus was able to degrade OTA with an initial concentration of OTA of 10 (μg/ml. The average amounts of OTA removed by A. calcoaceticus in medium with an initial OTA concentration of 10 (μg/ml were 0.1005 and 0.0636 (μg/ml/h at 25 and 30°C, respectively. Ochratoxin A was degraded significantly by A. calcoaceticus during and after the log phase of cell growth at both incubation temperatures. It is postulated that degradation of OTA by A. calcoaceticus yielded a less toxic ochratoxin α.
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Zheng, Rui, Hanrui Qing, Qiugang Ma, Xueting Huo, Shimeng Huang, Lihong Zhao, Jianyun Zhang, and Cheng Ji. "A Newly Isolated Alcaligenes faecalis ANSA176 with the Capability of Alleviating Immune Injury and Inflammation through Efficiently Degrading Ochratoxin A." Toxins 14, no. 8 (August 20, 2022): 569. http://dx.doi.org/10.3390/toxins14080569.
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Ochratoxin A (OTA) is one of the most prevalent mycotoxins that threatens food and feed safety. Biodegradation of OTA has gained much attention. In this study, an Alcaligenes faecalis strain named ANSA176, with a strong OTA-detoxifying ability, was isolated from donkey intestinal chyme and characterized. The strain ANSA176 could degrade 97.43% of 1 mg/mL OTA into OTα within 12 h, at 37 °C. The optimal levels for bacterial growth were 22–37 °C and pH 6.0–9.0. The effects of ANSA176 on laying hens with an OTA-contaminated diet were further investigated. A total of 36 laying hens were assigned to three dietary treatments: control group, OTA (250 µg/kg) group, and OTA + ANSA176 (6.2 × 108 CFU/kg diet) group. The results showed that OTA decreased the average daily feed intake (ADFI) and egg weight (EW); meanwhile, it increased serum alanine aminopeptidase (AAP), leucine aminopeptidase (LAP), β2-microglobulin (β2-MG), immunoglobulin G (IgG), tumor necrosis factor-α (TNF-α), and glutathione reductase (GR). However, the ANSA176 supplementation inhibited or attenuated the OTA-induced damages. Taken together, OTA-degrading strain A. faecalis ANSA176 was able to alleviate the immune injury and inflammation induced by OTA.
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Vlachou, Mikela, Andreana Pexara, Nikolaos Solomakos, and Alexander Govaris. "Ochratoxin A in Slaughtered Pigs and Pork Products." Toxins 14, no. 2 (January 19, 2022): 67. http://dx.doi.org/10.3390/toxins14020067.
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Ochratoxin A (OTA) is a mycotoxin that is produced after the growth of several Aspergillus and Penicillium spp. in feeds or foods. OTA has been proved to possess nephrotoxic, hepatotoxic, teratogenic, neurotoxic, genotoxic, carcinogenic and immunotoxic effects in animals and humans. OTA has been classified as possibly carcinogenic to humans (Group 2B) by the IARC in 2016. OTA can be mainly found in animals as a result of indirect transmission from naturally contaminated feed. OTA found in feed can also contaminate pigs and produced pork products. Additionally, the presence of OTA in pork meat products could be derived from the direct growth of OTA-producing fungi or the addition of contaminated materials such as contaminated spices. Studies accomplished in various countries have revealed that pork meat and pork meat products are important sources of chronic dietary exposure to OTA in humans. Various levels of OTA have been found in pork meat from slaughtered pigs in many countries, while OTA levels were particularly high in the blood serum and kidneys of pigs. Pork products made from pig blood or organs such as the kidney or liver have been often found to becontaminated with OTA. The European Union (EU) has established maximum levels (ML) for OTA in a variety of foods since 2006, but not for meat or pork products. However, the establishement of an ML for OTA in pork meat and meat by-products is necessary to protect human health.
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Ye, Hua, Mengyuan Wang, Xi Yu, Pengfei Ma, Ping Zhu, Jianjun Zhong, Kuo He, and Yuanxin Guo. "Molecular Docking Insight into the Label-Free Fluorescence Aptasensor for Ochratoxin A Detection." Molecules 28, no. 12 (June 18, 2023): 4841. http://dx.doi.org/10.3390/molecules28124841.
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Ochratoxin A (OTA) is the most common mycotoxin and can be found in wheat, corn and other grain products. As OTA pollution in these grain products is gaining prominence as a global issue, the demand to develop OTA detection technology has attracted increasing attention. Recently, a variety of label-free fluorescence biosensors based on aptamer have been established. However, the binding mechanisms of some aptasensors are still unclear. Herein, a label-free fluorescent aptasensor employing Thioflavin T (ThT) as donor for OTA detection was constructed based on the G-quadruplex aptamer of the OTA aptamer itself. The key binding region of aptamer was revealed by using molecular docking technology. In the absence of the OTA target, ThT fluorescent dye binds with the OTA aptamer to form an aptamer/ThT complex, and results in the fluorescence intensity being obviously enhanced. In the presence of OTA, the OTA aptamer binds to OTA because of its high affinity and specificity to form an aptamer/OTA complex, and the ThT fluorescent dye is released from the OTA aptamer into the solution. Therefore, the fluorescence intensity is significantly decreased. Molecular docking results revealed that OTA is binding to the pocket-like structure and surrounded by the A29-T3 base pair and C4, T30, G6 and G7 of the aptamer. Meanwhile, this aptasensor shows good selectivity, sensitivity and an excellent recovery rate of the wheat flour spiked experiment.
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Khoi, Chong-Sun, Yu-Wen Lin, Jia-Huang Chen, Biing-Hui Liu, Tzu-Yu Lin, Kuan-Yu Hung, and Chih-Kang Chiang. "Selective Activation of Endoplasmic Reticulum Stress by Reactive-Oxygen-Species-Mediated Ochratoxin A-Induced Apoptosis in Tubular Epithelial Cells." International Journal of Molecular Sciences 22, no. 20 (October 11, 2021): 10951. http://dx.doi.org/10.3390/ijms222010951.
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Ochratoxin A (OTA), one of the major food-borne mycotoxins, impacts the health of humans and livestock by contaminating food and feed. However, the underlying mechanism of OTA nephrotoxicity remains unknown. This study demonstrated that OTA induced apoptosis through selective endoplasmic reticulum (ER) stress activation in human renal proximal tubular cells (HK-2). OTA increased ER-stress-related JNK and precursor caspase-4 cleavage apoptotic pathways. Further study revealed that OTA increased reactive oxygen species (ROS) levels, and N-acetyl cysteine (NAC) could reduce OTA-induced JNK-related apoptosis and ROS levels in HK-2 cells. Our results demonstrate that OTA induced ER stress-related apoptosis through an ROS-mediated pathway. This study provides new evidence to clarify the mechanism of OTA-induced nephrotoxicity.
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Zheng, Qian-Wen, Xu-Fen Ding, Hui-Jun Cao, Qian-Zhi Ni, Bing Zhu, Ning Ma, Feng-Kun Zhang, et al. "Ochratoxin A Induces Steatosis via PPARγ-CD36 Axis." Toxins 13, no. 11 (November 13, 2021): 802. http://dx.doi.org/10.3390/toxins13110802.
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Ochratoxin A(OTA) is considered to be one of the most important contaminants of food and feed worldwide. The liver is one of key target organs for OTA to exert its toxic effects. Due to current lifestyle and diet, nonalcoholic fatty liver disease (NAFLD) has been the most common liver disease. To examine the potential effect of OTA on hepatic lipid metabolism and NAFLD, C57BL/6 male mice received 1 mg/kg OTA by gavage daily. Compared with controls, OTA increased lipid deposition and TG accumulation in mouse livers. In vitro OTA treatment also promoted lipid droplets accumulation in primary hepatocytes and HepG2 cells. Mechanistically, OTA prevented PPARγ degradation by reducing the interaction between PPARγ and its E3 ligase SIAH2, which led to activation of PPARγ signaling pathway. Furthermore, downregulation or inhibition of CD36, a known of PPARγ, alleviated OTA-induced lipid droplets deposition and TG accumulation. Therefore, OTA induces hepatic steatosis via PPARγ-CD36 axis, suggesting that OTA has an impact on liver lipid metabolism and may contribute to the development of metabolic diseases.
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Yu, Hao, and Qiang Zhao. "Aptamer Molecular Beacon Sensor for Rapid and Sensitive Detection of Ochratoxin A." Molecules 27, no. 23 (November 26, 2022): 8267. http://dx.doi.org/10.3390/molecules27238267.
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Ochratoxin A (OTA) is a carcinogenic fungal secondary metabolite which causes wide contamination in a variety of food stuffs and environments and has a high risk to human health. Developing a rapid and sensitive method for OTA detection is highly demanded in food safety, environment monitoring, and quality control. Here, we report a simple molecular aptamer beacon (MAB) sensor for rapid OTA detection. The anti-OTA aptamer has a fluorescein (FAM) labeled at the 5′ end and a black hole quencher (BHQ1) labeled at the 3′ end. The specific binding of OTA induced a conformational transition of the aptamer from a random coil to a duplex–quadruplex structure, which brought FAM and BHQ1 into spatial proximity causing fluorescence quenching. Under the optimized conditions, this aptamer sensor enabled OTA detection in a wide dynamic concentration range from 3.9 nM to 500 nM, and the detection limit was about 3.9 nM OTA. This method was selective for OTA detection and allowed to detect OTA spiked in diluted liquor and corn flour extraction samples, showing the capability for OTA analysis in practical applications.
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KURUC, JULIE, JUSTIN HEGSTAD, HYUN JUNG LEE, KRISTIN SIMONS, DOJIN RYU, and CHARLENE WOLF-HALL. "Infestation and Quantification of Ochratoxigenic Fungi in Barley and Wheat Naturally Contaminated with Ochratoxin A." Journal of Food Protection 78, no. 7 (July 1, 2015): 1350–56. http://dx.doi.org/10.4315/0362-028x.jfp-14-578.
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Cereal grains are a significant source of ochratoxin A (OTA) in the human diet. Multiple ochratoxigenic Aspergillus and Penicillium spp. have been reported as contaminants on various cereal grains around the world, although relatively few species dominate in any given location. Efforts to mitigate the risk of fungal contamination and OTA accumulation can be made pre- and postharvest. Still, a rapid and reliable screening method is sought that can be used to predict the OTA level of a sample and to inform risk assessments prior to processing. In this study, we assessed the efficacy of two OTA-related indices for OTA level prediction. Infestation rates were determined by direct plating for freshly harvested and stored barley, durum, and hard red spring wheat samples (n = 139) with known OTA levels. Presumptive ochratoxigenic isolates were tested for their ability to produce OTA. The nonribosomal peptide synthase (otanpsPN) involved in OTA biosynthesis was used to quantify ochratoxigenic fungi in barley and wheat. Viable Penicillium verrucosum was present in 45% of the samples. In total, 62.7% (n = 110) of the P. verrucosum isolates tested produced OTA on dichloran yeast extract sucrose 18% glycerol agar. Both OTA level and infestation rate (r = 0.30), as well as OTA level and otanpsPN concentration (r = 0.56), were weakly correlated. Neither infestation rate nor otanpsPN concentration is a reliable predictor of OTA level in a sample.
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Ahmad, F., H. Khan, K. Khan, FA Khan, N. Ahmad, M. Saeed, and T. Ayasan. "Effects of ochratoxin on the performance, haematobiochemical profile, macroscopic and histopathological lesions in quails (Coturnix coturnix Japonica)." Journal of the Hellenic Veterinary Medical Society 74, no. 3 (October 16, 2023): 5953–60. http://dx.doi.org/10.12681/jhvms.30561.
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Mycotoxins are ubiquitous in the environment and occur naturally in human food and animal feed. Therefore, in this study the performance, haematobiochemical profiles, macroscopic and histopathological lesions in quails caused by ochratoxin (OTA) were examined. The OTA was obtained by culturing the spore of Aspergillus ochraceus. Sixty healthy male quails were selected and distributed into 12 replicates (5 quails per replicate) in a completely randomized block arrangement. Each experimental diet was assigned to 4 replicate groups. Quails in first group were fed on standard basal diet (CP 27%) without the addition of OTA (OTA-0; negative control), while in other groups OTA was incorporated in basal diet at 1 mg/kg (OTA-1) and 2 mg/kg (OTA-2) of basal diet, respectively. The feeding trial continued for 21 days experimental period. Clinical signs observed in OTA-fed birds were diarrhea, broken feathers, increased water intake, and depression. In addition, lower (p < 0.05) feed intake was reported in OTA-fed quails. Likewise, weight gain was reduced (p < 0.05) in OTA-fed groups. Gross lesions of hypertrophy, hemorrhages, paleness and friability were detected in the liver and kidney of OTA-treated birds. Microscopic examination of kidney and liver showed degeneration and sloughing of tubular epithelium in the kidney, narrowing of the lumen of kidney tubules, and hepatic fatty infiltration and necrosis of liver parenchyma. The serum Alanine transaminase, Aspartate transaminase, urea, and creatinine levels of OTA-fed birds were higher (p < 0.05) than OTA-0. However, serum total protein and albumin were lower (p < 0.05) in OTA-treated groups in a dose- dependent manner. Likely, red blood cell count, packed cell volume, and hemoglobin concentration were lower (p < 0.05) in OTA-treated groups. The results of this study indicate that OTA at ≥ 1 mg/kg feed is nephrotoxic and hepatotoxic, and cause hematobiochemical disorder in quails, which adversely affect their growth performance and may eventually lead to economic losses.
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GHORI, A., and P. GHOSH. "ANALYSIS OF OPERATIONAL TRANSCONDUCTANCE AMPLIFIER FOR APPLICATION IN GHz FREQUENCY RANGE." International Journal of High Speed Electronics and Systems 14, no. 03 (September 2004): 690–95. http://dx.doi.org/10.1142/s0129156404002685.
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Operational Transconductance Amplifier (OTA) is an excellent current mode device suited very well for VLSI implementation. In this contribution we report realization of OTA using Silicon-On-Insulator (SOI) structure based MOSFETs and compared them to OTA designed with bulk MOSFET. SOI based OTA outperformed bulk MOSFET OTA giving close to 10 GHz improvement in high frequency f T . A band-pass filter was implemented with SOI based OTA with a center frequency of 7 GHz and a bandwidth of 480 kHz.
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Khoi, Chong-Sun, Jia-Huang Chen, Tzu-Yu Lin, Chih-Kang Chiang, and Kuan-Yu Hung. "Ochratoxin A-Induced Nephrotoxicity: Up-to-Date Evidence." International Journal of Molecular Sciences 22, no. 20 (October 18, 2021): 11237. http://dx.doi.org/10.3390/ijms222011237.
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Ochratoxin A (OTA) is a mycotoxin widely found in various foods and feeds that have a deleterious effect on humans and animals. It has been shown that OTA causes multiorgan toxicity, and the kidney is the main target of OTA among them. This present article aims to review recent and latest intracellular molecular interactions and signaling pathways of OTA-induced nephrotoxicity. Pyroptosis, lipotoxicity, organic anionic membrane transporter, autophagy, the ubiquitin-proteasome system, and histone acetyltransferase have been involved in the renal toxicity caused by OTA. Meanwhile, the literature reviewed the alternative or method against OTA toxicity by reducing ROS production, oxidative stress, activating the Nrf2 pathway, through using nanoparticles, a natural flavonoid, and metal supplement. The present review discloses the molecular mechanism of OTA-induced nephrotoxicity, providing opinions and strategies against OTA toxicity.
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Jayachandran, Remya, Dhanaraj Jagalchandran, and Perinkolam Chidambaram Subramaniam. "Planar CMOS and multigate transistors based wide-band OTA buffer amplifiers for heavy resistance load." Facta universitatis - series: Electronics and Energetics 35, no. 1 (2022): 13–28. http://dx.doi.org/10.2298/fuee2201013j.
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Analog buffer amplifier configurations capable of driving heavy resistive load using different operational transconductance amplifier (OTA) are presented in this paper. The OTA CMOS buffer configurations are designed using 0.18 ?m SCL technology library in Cadence Virtuoso tool and multigate transistor OTA buffer in TCAD Sentaurus tool. CMOS OTA buffer configuration using simple OTA outperform the OTA buffer circuits using other OTAs in terms of power dissipation and stability. Measured results show that the OTA buffer circuit works well for resistive load below 100 ?. The gain tuning of up to 5 V/V is achieved with RL equal to 50 ?, output swing of 1 V. OTA buffer configuration implemented using multigate transistor with resistive load below 1 k? exhibits a bandwidth around 5 GHz and tunable gain up to 5 V/V.
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DEL PRETE, VINCENZO, HECTOR RODRIGUEZ, ALFONSO V. CARRASCOSA, BLANCA de las RIVAS, EMILIA GARCIA-MORUNO, and ROSARIO MUÑOZ. "In Vitro Removal of Ochratoxin A by Wine Lactic Acid Bacteria." Journal of Food Protection 70, no. 9 (September 1, 2007): 2155–60. http://dx.doi.org/10.4315/0362-028x-70.9.2155.
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A study was carried out to determine the in vitro interaction between ochratoxin A (OTA) and wine lactic acid bacteria (LAB). Fifteen strains belonging to five relevant oenological LAB species were grown in liquid synthetic culture medium containing OTA. The portion of OTA removed during the bacterial growth was 8 to 28%. The OTA removed from the supernatants was partially recovered (31 to 57%) from the bacterial pellet. Cell-free extracts of three representative strains were produced by disrupting cells in a French pressure cell. The ability of crude cell-free extracts to degrade OTA was studied. OTA was not degraded by cell-free extracts of wine LAB strains, and no degradation products of OTA were detected in the high-performance liquid chromatograms of the methanol extract of the bacterial pellet. On the basis of these results, we conclude that OTA removal by wine LAB is a cell-binding phenomenon. The chemistry and the molecular basis of OTA binding to wine LAB remains unknown.
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Zhao, Han, Xinying Xiang, Mingjian Chen, and Changbei Ma. "Aptamer-Based Fluorometric Ochratoxin A Assay Based on Photoinduced Electron Transfer." Toxins 11, no. 2 (January 24, 2019): 65. http://dx.doi.org/10.3390/toxins11020065.
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This study describes a novel quencher-free fluorescent method for ochratoxin A (OTA) detection based on the photoinduced electron transfer (PIET) between guanine and fluorophore. In the absence of OTA, carboxyfluorescein (FAM)-labeled aptamer can partly hybridize with the complementary strand of OTA aptamer (OTA-cAPT), which contains four guanines at its 3′-end. As a result, the fluorescence of FAM is quenched due to PIET and stacked guanines. In the presence of OTA, FAM-labeled OTA aptamer can bind specifically to OTA, and thereby the high fluorescence intensity of the dye can be maintained. Under the optimal conditions, the method had a detection limit of 1.3 nM. In addition, the method we proposed is highly sensitive and specific for OTA. Furthermore, the method was proven to be reliable based on its successful application in the detection of OTA in red wine samples. Therefore, this promising, facile, and quencher-free method may be applied to detect other toxins by using other appropriate aptamers.
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Dubey, Tanmay, Vijaya Bhadauria, and Rishikesh Pandey. "Linearity Enhancement Techniques for Operational Transconductance Amplifier: A Survey." Recent Advances in Electrical & Electronic Engineering (Formerly Recent Patents on Electrical & Electronic Engineering) 13, no. 5 (September 22, 2020): 650–68. http://dx.doi.org/10.2174/2352096512666191019130214.
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Background: Operational Transconductance Amplifier (OTA) plays an essential role in many analog and mixed-signal applications that encourages the researchers to contribute their work to design suitable structures of OTA for their applications with acceptable performance parameters. Methods: The linearity of an OTA is one of its key performance parameters, which affects the performance of the overall system whereas the transconductance value of OTA (Gm) contributes to decide its application area. Low transconductance OTA finds its application in biomedical and neural networks while OTA with higher transconductance is suitable for wireless communication. In any system, it is desirable to obtain a linear voltage-to-current conversion, i.e., OTA, hence various linearization techniques have been reported to linearize the OTA. Results: In the last two decades, various OTA structures have been reported with linear voltage-tocurrent conversion. Some researchers used attenuation by means of different circuit approaches to linearize the OTA or some used cancellation of nonlinearity terms by using different circuit implementation techniques. Researchers used some other methods also to linearize the OTA viz source degeneration, square root technique and mobility compensation. Conclusion: The purpose of this paper is to provide a brief survey of various popular linearization techniques reported in the past.
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Ferrara, Massimo, Antonia Gallo, Carla Cervini, Lucia Gambacorta, Michele Solfrizzo, Scott E. Baker, and Giancarlo Perrone. "Evidence of the Involvement of a Cyclase Gene in the Biosynthesis of Ochratoxin A in Aspergillus carbonarius." Toxins 13, no. 12 (December 13, 2021): 892. http://dx.doi.org/10.3390/toxins13120892.
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Ochratoxin A (OTA) is a well-known mycotoxin with wide distribution in food and feed. Fungal genome sequencing has great utility for identifying secondary metabolites gene clusters for known and novel compounds. A comparative analysis of the OTA-biosynthetic cluster in A. steynii, A. westerdijkiae, A. niger, A. carbonarius, and P. nordicum has revealed a high synteny in OTA cluster organization in five structural genes (otaA, otaB, ota, otaR1, and otaD). Moreover, a recent detailed comparative genome analysis of Aspergilli OTA producers led to the identification of a cyclase gene, otaY, located in the OTA cluster between the otaA and otaB genes, encoding for a predicted protein with high similarity to SnoaLs domain. These proteins have been shown to catalyze ring closure steps in the biosynthesis of polyketide antibiotics produced in Streptomyces. In the present study, we demonstrated an upregulation of the cyclase gene in A. carbonarius under OTA permissive conditions, consistent with the expression trends of the other OTA cluster genes and their role in OTA biosynthesis by complete gene deletion. Our results pointed out the involvement of a cyclase gene in OTA biosynthetic pathway for the first time. They represent a step forward in the understanding of the molecular basis of OTA biosynthesis in A. carbonarius.
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Kotha, Sreeteja Reddy, Karuppanan P, Abhay Kumar Gautam, and Manmath Suryavanshi. "A 0.25-V Three-stage State Feedback Bulk-driven OTA for Wide Range Load Applications." Journal of Integrated Circuits and Systems 16, no. 3 (December 31, 2021): 1–9. http://dx.doi.org/10.29292/jics.v16i3.498.
Full textAbstract:
This article employs a nested state feedback compensation technique to a three-stage bulk-driven operational transconductance amplifier (OTA). The projected OTA circuit consists of a bulk-driven PMOS amplifier, gate-driven NMOS amplifier, and common source (CS) amplifier. The entire transistors in the amplifier core are configuredwith self-cascode transistor topology to increase its output impedance. All transistors are designed to operate in a weak inversion in order to dissipate less power. Cross-coupled transistor pair topology in the bulk-driven stage allows to improve the effective transconductance of OTA. The CS amplifier can drive a large load capacitor. The polarities and transconductance gains of feedback blocks are controlled appropriately to obtain the desired DC gain and bandwidth. The capacitor-less compensation strategy allows the fabrication of the OTA using the minimum area. Conventional bulk-driven miler OTA, Bulk-driven stage improved indirect-feedback OTA (BSIF OTA), Gate-driven stage added bulk-driven OTA (GSIF OTA), and proposed bulk-driven OTA topologies are designed and simulated using cadence spectre tool at 25 mV supply voltage in the 65nm CMOS process. These OTA circuits are analyzed and compared in terms of parameters like DC gain, unity-gain frequency, phase margin, CMRR, power dissipated, slew rate, and input referred noise.
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Zhang, Ziqiang, Jingyi Xu, Xin Zhang, Jiajia Wang, Hui Xie, Yingying Sun, Qianwen Zhang, Zhaoyang Chang, and Yumei Liu. "Protective Effect of SeMet on Liver Injury Induced by Ochratoxin A in Rabbits." Toxins 14, no. 9 (September 8, 2022): 628. http://dx.doi.org/10.3390/toxins14090628.
Full textAbstract:
Ochratoxin A (OTA) is second only to aflatoxin in toxicity among mycotoxins. Recent studies have shown that selenomethionine (SeMet) has a protective effect on mycotoxin-induced toxicity. The purpose of this study was to investigate the protective effect and mechanism of SeMet on OTA-induced liver injury in rabbits. Sixty 35-day-old rabbits with similar body weight were randomly divided into five groups: control group, OTA group (0.2 mg/kg OTA), OTA + 0.2 mg/kg SeMet group, OTA + 0.4 mg/kg SeMet group and OTA + 0.6 mg/kg SeMet group. Rabbits were fed different doses of the SeMet diet for 21 d, and OTA was administered for one week from day 15 (the control group was provided the same dose of NaHCO3 solution). The results showed that 0.4 mg/kg SeMet could significantly improve the liver injury induced by OTA poisoning. SeMet supplementation can improve the changes in physiological blood indexes caused by OTA poisoning in rabbits and alleviate pathological damage to the rabbit liver. SeMet also increased the activities of SOD, GSH-Px and T-AOC and significantly decreased the contents of ROS, MDA, IL-1β, IL-6 and TNF-α, effectively alleviating the oxidative stress and inflammatory response caused by OTA poisoning. In addition, OTA poisoning inhibits Nrf2 and HO-1 levels, ultimately leading to peroxide reaction, while SeMet activates the Nrf2 signaling pathway and enhances the expression of the HO-1 downstream Nrf2 gene. These results suggest that Se protects the liver from OTA-induced hepatotoxicity by regulating Nrf2/HO-1 expression.
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Al-Eisa, Rasha A., Mahmoud Helal, Amani H. Aljahani, Rokayya Sami, Hamsa Jameel Banjer, Naseh A. Algehainy, Mohammad Y. Alshahrani, Amal Adnan Ashour, and Ali A. Alqarni. "Ochratoxin A oral mycotoxin and honey dietary intake effects on TNF-α immunology response, lactic acid bacteria microbial louds, β-glucuronidase enzyme activity, some hematological and biochemical parameters on mice." Materials Express 13, no. 7 (July 1, 2023): 1203–11. http://dx.doi.org/10.1166/mex.2023.2462.
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The current study aimed to evaluate ochratoxin A oral mycotoxin and the dietary intake effects of four honey varieties (Nigella sativa, moringa, sidr, and pumpkin–coded as NS, MO, SI, and PU respectively), on the TNF-α immunology response, lactic acid bacteria microbial louds (Lactobacilli and Bifidobacteria), β-glucuronidase enzyme activity, some hematological and biochemical parameters of mice. MO Honey Group + OTA Infection had the highest value of TNF-α immunology response at 445.17 pg/mL. It was followed by PU Honey Group + OTA Infection at 360.88 pg/mL, while NS Honey Group + OTA Infection reported the lowest at 210.03 pg/mL. Honey dietary intake efficiently increased the colonic probiotic bacteria counts Lactobacilli and Bifidobacteria, in the animal’s cecum from 0.93 in SI Honey Group + OTA Infection to 2.59 in MO Honey Group + OTA Infection and from 1.78 in PU Honey Group + OTA Infection to 3.22 in NS Honey Group + OTA Infection Log 10 CFU/g, respectively. The β-glucuronidases enzyme activity in the caecum contents of mice groups ranged from 0.31 μmol/g in PU Honey Group + OTA Infection to 0.36 μmol/g in SI Honey Group + OTA Infection. Positive and negative control mice groups reported 7.22 and 6.98 × 109 L−1; 8.09 and 8.44 × 1012 L−1 for white blood cell and red blood cell counts, respectively. The mean glutathione concentrations were from 3.17 ng/g in MO Honey Group + OTA Infection, to 4.32 ng/g in SI Honey Group + OTA Infection. Catalase activities ranged from 0.99 u/gin MO Honey Group + OTA Infection to 1.08 u/g in the PU Honey Group + OTA Infection. Honey dietary intake decreased malondialdehyde concentrations in infected mice groups and ranged from 3.84 nmol/g in NS Honey Group + OTA Infection to 5.47 nmol/g in MO Honey Group + OTA Infection. NS Honey Group + OTA Infection reported the lowest values for alkaline phosphatase as 70.15 U L−1, glucose as 6.12 mmol L−1, and urea as 4.89 mmol L−1. SI Honey Group + OTA Infection reported the highest values for AP as 75.52 U L−1 and urea as 5.78 mmol L−1. PU Honey Group + OTA Infection reported the lowest value for ALT as 55.47 U L−1 and the highest value for glucose as 7.88 mmol L−1.
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Manderville, R., and A. Pfohl-Leszkowicz. "Bioactivation and DNA adduction as a rationale for ochratoxin A carcinogenesis." World Mycotoxin Journal 1, no. 3 (August 1, 2008): 357–67. http://dx.doi.org/10.3920/wmj2008.x039.
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Ochratoxin A (OTA) is a para-chlorophenolic mycotoxin produced by strains of Aspergillus and Penicillium that is widely found as a contaminant of improperly stored food products. The toxin is a potent renal carcinogen in rats, especially male, and has an implicated role in the etiology of Balkan endemic nephropathy and its associated urinary tract tumours. Although the mechanism of OTA-mediated tumour formation is not fully understood, and represents a hotly debated topic, bioactivation and subsequent DNA adduction through covalent attachment of electrophilic OTA species remains a viable mechanism for OTA-mediated carcinogenesis. In this paper we outline the established chemistry for the bioactivation of chlorophenol carcinogens and demonstrate how this chemistry relates to the bioactivation of OTA. From this basis it is predicted that OTA will form a benzoquinone electrophile following activation by cytochrome P450 enzymes and radical species following activation by enzymes with peroxidase activities. These electrophiles react preferentially with deoxyguanosine (dG) to form benzetheno adducts and C8- dG adducts, respectively. Analysis of OTA-mediated DNA adduction using the 32P-postlabelling method correlates with OTA chemistry and adduct spots derived from the quinone electrophile are generated following activation by cytochrome P450, while a C8-OTA adduct is formed following activation of OTA by peroxidase enzymes. These same adduct spots are also produced in animal (rat and pig) and human tumoral kidney tissue. This model for OTAmediated carcinogenesis is consistent with established structure-activity relationships for covalent attachment of OTA analogues and OTA toxicity. The model also provides a rationale for the synergistic effect observed for OTA in the presence of the mycotoxin citrinin and for the sexual differences observed in rat carcinogenesis where the male is particularly susceptible to OTA-mediated tumour formation.
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Whitaker, T. B., A. B. Slate, T. W. Nowicki, and F. G. Giesbrecht. "Variability and distribution among sample test results when sampling unprocessed wheat lots for ochratoxin A." World Mycotoxin Journal 9, no. 2 (March 11, 2016): 163–78. http://dx.doi.org/10.3920/wmj2015.1970.
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In 2008, Health Canada announced it was considering the establishment of maximum levels for ochratoxin A (OTA) in unprocessed wheat, oats, and their products. The Canada Grains Council and Canadian National Millers Association initiated two studies to measure the variability and distribution among sample test results for unprocessed wheat and oats so that scientifically based OTA sampling plans could be designed to meet regulatory and industry requirements. Sampling statistics related to detecting OTA in oats has been published. 54 OTA contaminated wheat lots representing three wheat classes were identified for the sampling study. Each lot was sampled according to a nested experimental protocol where sixteen 2-kg laboratory samples were taken from each lot, multiple 5-g test portions were taken from each comminuted 2-kg laboratory sample, and multiple OTA measurements were made on each test portion using liquid chromatography. The sampling, sample preparation, and analytical variances associated with each step of the OTA test procedure were found to be a function of OTA concentration and regression equations were developed to predict the functional relationships between variance and OTA concentration. When sampling a wheat lot containing 5 µg/kg OTA with an OTA test procedure consisting of a sampling step employing a single 2-kg laboratory sample, sample preparation step employing a single 100-g test portion, and an analytical step that used liquid chromatography to quantify OTA, the sampling step accounted for 95.3% of the total variability. The observed OTA distribution among the 16 OTA sample results was found to be positively skewed and the negative binomial distribution was selected to model the OTA distribution among sample test results. The sampling statistics were incorporated into the FAO Mycotoxin Sampling Tool and the chances of rejecting good lots and accepting bad lots were calculated for various sampling plan designs.
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Rašić, D., D. Želježić, N. Kopjar, D. Kifer, M. Šegvić Klarić, and M. Peraica. "DNA damage in rat kidneys and liver upon subchronic exposure to single and combined ochratoxin A and citrinin." World Mycotoxin Journal 12, no. 2 (April 3, 2019): 163–72. http://dx.doi.org/10.3920/wmj2018.2399.
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The study aimed to check whether ochratoxin A (OTA) and citrinin (CIT) increase DNA damage in the kidney and liver of male Wistar rats (alkaline comet assay), clarify the oxidative nature of DNA damage (hOGG1-modified comet assay), and verify whether resveratrol (RSV) could ameliorate OTA+CIT-induced genotoxicity. Rats were treated orally with OTA (0.125 and 0.250 mg/kg bodyweight (bw)) and CIT (2 mg/kg bw), OTA+CIT combinations and OTA+CIT+RSV (0.250+2+20 mg/kg bw) for 21 days. Both alkaline and hOGG1-modified comet assay showed that DNA damage was more severe in rat kidneys than in liver following mycotoxin treatment. Alkaline comet assay revealed a higher intensity of DNA damage, particularly as measured by tail intensity in the kidneys. Both tail length and tail intensity were OTA dose-dependent, but in combined OTA+CIT treatment these values were similar to CIT alone and lower than in animals treated with single OTA, possibly due to induction of apoptosis. hOGG1-modified comet showed that OTA+CIT evoked greater oxidative DNA damage than single mycotoxins. RSV did not reduce DNA damage measured by alkaline comet assay, but hOGG1-modified comet showed that RSV ameliorated OTA+CIT genotoxicity in the kidneys. Apart from oxidative stress, other mechanisms of DNA damage are involved in OTA and CIT genotoxicity. In rat kidneys RSV can reduce but not overcome oxidative DNA damage induced by combined OTA and CIT.
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Zapaśnik, Agnieszka, Marcin Bryła, Agnieszka Waśkiewicz, Edyta Ksieniewicz-Woźniak, and Grażyna Podolska. "Ochratoxin A and 2′R-Ochratoxin A in Selected Foodstuffs and Dietary Risk Assessment." Molecules 27, no. 1 (December 29, 2021): 188. http://dx.doi.org/10.3390/molecules27010188.
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The aim of this study was to estimate the contamination of grain coffee, roasted coffee, instant coffee, and cocoa purchased in local markets with ochratoxin A (OTA) and its isomerization product 2′R-ochratoxin A (2′R-OTA), and to assess risk of dietary exposure to the mycotoxins. OTA and 2′R-OTA content was determined using the HPLC chromatography with immunoaffinity columns dedicated to OTA. OTA levels found in all the tested samples were below the maximum limits specified in the European Commission Regulation EC 1881/2006. Average OTA concentrations calculated for positive samples of grain coffee/roasted coffee/instant coffee/cocoa were 0.94/0.79/3.00/0.95 µg/kg, with the concentration ranges: 0.57–1.97/0.44–2.29/0.40–5.15/0.48–1.97 µg/kg, respectively. Average 2′R-OTA concentrations calculated for positive samples of roasted coffee/instant coffee were 0.90/1.48 µg/kg, with concentration ranges: 0.40–1.26/1.00–2.12 µg/kg, respectively. In turn, diastereomer was not found in any of the tested cocoa samples. Daily intake of both mycotoxins with coffee/cocoa would be below the TDI value even if the consumed coffee/cocoa were contaminated with OTA/2′R-OTA at the highest levels found in this study. Up to now only a few papers on both OTA and 2′R-OTA in roasted food products are available in the literature, and this is the first study in Poland.
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SU, HSIAO WEI, and YICHUANG SUN. "HIGH-FREQUENCY LINEAR MULTIPLE-OUTPUT CMOS TRANSCONDUCTANCE AMPLIFIER FOR CURRENT-MODE FILTERS." Journal of Circuits, Systems and Computers 15, no. 05 (October 2006): 701–17. http://dx.doi.org/10.1142/s0218126606003325.
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A high-frequency highly linear tunable CMOS multiple-output operational transconductance amplifier (MO-OTA) for fully balanced current-mode OTA and capacitor (OTA-C) filters is presented. The MO-OTA is based on the cross-coupled pairs at the input and provides two pairs of differential outputs. A simple common-mode feedback (CMFB) circuit to stabilize the DC output levels of the MO-OTA is also proposed and two such CMFB circuits are used by the MO-OTA. The proposed MO-OTA is suitable for relatively low voltage (2.5 V) applications as its circuit has only two MOS transistors between the supply and ground rails. Simulated in a TSMC 0.25 μm CMOS process using PSpice, the MO-OTA has at least ± 0.3 V linear differential input signal swing with a single 2.5 V power supply and operates up to 1 GHz frequency. The MO-OTA has a THD less than -46 dB for a differential input voltage of 0.9 Vp-p at 10 MHz, dynamic range (DR) at THD = -46 dB is over 50 dB, and power consumption (with the common-mode feedback circuit) is below 8 mW for the whole tuning range. A fully balanced multiple loop feedback current-mode OTA-C filter example using the proposed MO-OTA is presented. This example also shows that the current-mode follow-the-leader-feedback (FLF) structure can achieve good performances for OTA-C filter design.