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Háttér és célkitűzések

A halogató viselkedés kutatásában egyre hangsúlyosabb szerepet kap a maladaptív passzív halogatás és a hatékony stratégiaként alkalmazható aktív halogatás elkülönítése. Tanulmányunk célja a Choi és Moran (2009) által kidolgozott Aktív-Passzív Halogatás Kérdőív magyar változatának (Szabó, 2012) pszichometriai tesztelése volt. Módszer: Magyar egyetemi hallgatókból álló mintán (N = 843) ellenőriztük a kérdőív struktúráját, reliabilitását és kapcsolatát más pszichológiai tényezőkkel.

Eredmények

A feltáró és megerősítő faktorelemzések alapján egy passzív és egy aktív halogatás alskála jelenik meg a korábbiakban használt ötfaktoros struktúrával szemben. Az alskálák belső megbízhatósága jónak tekinthető. Az aktív halogatás pozitív, míg a passzív halogatás negatív kapcsolatban áll az önértékeléssel és a tanulási énhatékonysággal. Az időperspektívát tekintve a passzív halogatás a múlt-negatív orientációval pozitív, míg a jövőorientációval negatív együtt járást mutat. A halogatásfaktorokon alapuló klaszterelemzés szerint kialakított csoportok között különbség van a tanulási eredmény tekintetében. A legeredményesebbek a nem halogatók csoportjába tartozók, őket követik az aktív és a passzív halogatók.

Következtetések

Az eredmények alapján kapott nyolcitemes kérdőív alkalmas a klasszikus passzív halogatás, illetve az időnyomás-preferencia kapcsán kialakuló aktív halogatás elkülönítésére. Azonban az eredeti modellben használt további aktívhalogatás-típusok feltárására más eszközök kidolgozása szükséges.

Open access

This study was conducted to assess the effects of 2,4-epibrassionolide (EBR) on mold decay caused by Rhizopus stolonifer and its capability to activate biochemical defense reactions in postharvest peaches. The treatment of EBR at 5 μM possessed the optimum effectiveness on inhibiting the Rhizopus rot in peach fruit among all treatments. The EBR treatment significantly up-regulated the expression levels of a set of defense-related enzymes and PR genes that included PpCHI, PpGns1, PpPAL, PpNPR1, PpPR1 and PpPR4 as well as led to an enhancement for biosynthesis of phenolics and lignins in peaches during the incubation at 20 °C. Interestingly, the EBR-treated peaches exhibited more striking expressions of PR genes and accumulation of antifungal compounds upon inoculation with the pathogen, indicating a priming defense could be activated by EBR. On the other hand, 5 μM EBR exhibited direct toxicity on fungal proliferation of R. stolonifer in vitro. Thus, we concluded that 5 μM EBR inhibited the Rhizopus rot in peach fruit probably by a direct inhibitory effect on pathogen growth and an indirect induction of a priming resistance. These findings provided a potential alternative for control of fungal infection in peaches during the postharvest storage.

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Absztrakt:

A hallásjavító implantátumok térnyerésével szinte bármely súlyosságú halláscsökkenés hatékonyan rehabilitálható. Magyarországon először a Pécsi Tudományegyetem Klinikai Központjának Fül-Orr-Gégészeti és Fej-Nyaksebészeti Klinikáján került sor Codacs™ (Cochlear’s direct acoustic cochlear stimulator; Cochlear, Sydney, Ausztrália) implantációjára. Ez az implantátum egy, a középfülbe helyezhető elektromechanikus elven működő hallásjavító eszköz, melyet súlyos fokú, siketséggel határos, kevert típusú, kétoldali halláscsökkenés esetén ajánlhatunk fel betegeinknek. Esetünkben kétoldali előrehaladott otosclerosisban szenvedő, 67 éves férfi betegünk részesült Codacs™-implantációban, mellyel páciensünk posztoperatív hallásküszöbe és beszédértése nagymértékben javult. Orv Hetil. 2020; 161(24): 1015–1019.

Open access

Microalgae are promising alternatives to sequestration of carbon and reduction of environmental problems, e.g. the greenhouse effect and industrial water pollution. Depending on the growth conditions, microalgae can differ in their metabolism products, leading them to grow at different rates. Intracellular reactions and nutritional requirements from cell metabolism, as well as biomass composition, may vary in function of the temperature. In this study, the biotechnological potential of three microalgae strains from the species was evaluated in terms of growth, biomass composition, fatty acid profile, and chlorophyll and carotenoids contents. Each of the three species demonstrated different potential depending on their metabolisms: Scenedesmus spinosus presented fastest growth and had the highest protein content (52.99%), Pseudokirchneriella subcapitata presented the highest content of lipid extracted (26.51%), and Scenedesmus acuminatus showed increased production of chlorophyll (5.25 mg l–1) and carotenoid (1.02 mg l–1) pigments.

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Consumer concern over artificial food additives has stimulated production of pigments from natural sources. The aim of this study was to examine the effects of process variables on the content of colour compounds (betaxanthin and betacyanin) in beetroot peel juice extracted by conventional method. In this research, the extraction processes were carried out according to the central composite design with different process variables. Quantitative measurements of the basic colour compounds in beetroot extract were performed using spectrophotometer. From our experiment, it was found that the most adequate extraction conditions, which gave the highest yield of colour compounds (952.5 mg l–1 of betaxanthin and 1361 mg l–1 of betacyanin), were extraction time 1 h, operating temperature 20 ºC, and solvent ratio 0.8 w/v. Being a conventional heating method, it is a simple and cost efficient process with relatively high yield.

Open access

Abstract

Sodium polystyrene sulfonate (SPS) powder is in use for over 50 years for the treatment of hyperkalemia. SPS powder is official in United States Pharmacopoeia, British Pharmacopoeia and European Pharmacopoeia. However, till date, no study has been published on the assessment of organic impurities for this drug. The organic impurities in bulk drug and finished product are associated with their safety, efficacy and stability. A simple, rapid, specific, precise and an accurate HPLC method has been developed for the estimation of toxic organic impurities like styrene, naphthalene, divinyl benzene (DVB) and ethylvinyl benzene (EVB) from SPS bulk drug and finished product. The developed method was validated for specificity, accuracy, precision, linearity, limit of detection (LOD), limit of quantitation (LOQ), solution stability, ruggedness and robustness. The influence of acid, alkali, oxidative stress, photolytic stress, thermal stress and humidity stress conditions on SPS bulk powder and finished product has been studied and reported. The proposed method can be successfully employed for the impurity testing of commercial batches of the bulk drug and finished products of both sodium salt and calcium salt of polystyrene sulfonate.

Open access

Tomatoes (Solanum lycopersicon L.) are one of the most important and most widely consumed vegetables in the world. The fruit contains considerable amount of different phytonutrients such as carotenoids, tocopherols, and vitamin C. In the present work, effects of some abiotic factors on the concentration of phytonutrients were investigated in tomato cultivated in two different types of soil. It was found that the type of soil had slight effect on the most important vital nutrients, while the ecological factors, particularly precipitation and average temperature 3 weeks before harvest, were of significant influence on such nutrients. It was found that low temperature and high precipitation before harvest caused the levels of carotenoids, tocopherol, and vitamin C to significantly increase by 65%, 46%, and 28%, respectively.

Open access

Barberry is a native Iranian plant including species Berberis integerrima and B. vulgaris. Barberry fruit is used for preparing sauces, jellies, carbonated drinks, candies, food colour powders, jams, marmalades, chocolates, juices, and nectars. They are used as a natural food colorant rich in anthocyanins instead of harmful artificial ones. They contain polyphenols and antioxidants that reduce damage from free radicals and prevent chronic diseases and cancers. Barberry fruit extracts were encapsulated in maltodextrin by spray drying and Liposome Entrapment. The sizes of spray dried particles were reported 1–20 μm by SEM. Dimensions of empty and extract loaded liposomes (B. vulgaris and B. integerrima) were 18–28, 37–51, and 51–77 nm, respectively, by FE-SEM. The moist diameter of liposomes measured by dynamic light scattering (DLS) method at day 0 and after 6 months at –18 °C were as follows; empty liposomes: 163.9±2.23 and 378.90±4.98, liposomes loaded with extracts: 135.2±2.04 and 160.90±2.19 (B. vulgaris) and 113.4±1.83 and 144.20±2.01 nm (B. integerrima). Evaluation of thermal-oxidative decomposition from Differential scanning calorimetry (DSC) results at 0–45–90 days showed that the antioxidant activity and the onset temperature of the encapsulated extract was higher than the control. The extracts encapsulated in liposomes, especially B. integerrima extract, had better antioxidant properties.

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There is a great demand for developing efficient anthocyanins extraction related to each plant material. Conventional methods have been replaced by novel techniques, but they might remain attractive when combined with the latter. Anthocyanins extraction from fresh and dried red cabbage was investigated by maceration, ultrasonication, and with enzymes. Pre-treatments through drying determined an improved extraction with respect to fresh samples, freeze-drying emerging as the best method. Combined enzyme-assisted extraction with maceration resulted in higher yield by conducting several extractions (1078.8±12.5 mg/100 g DW). The kinetic studies revealed good stability of anthocyanins at 50 °C, while constant degradation at 80 °C. The rate constant k at 80 °C and pH 3.5 was 1.7 10–3 min–1 and the half-life time t 1/2 was 6.7 h. Thermal analysis evidenced heat-induced changes in particular for extracts undergoing pre-heating. These results are valuable for optimal processing conditions of anthocyanins-containing products.

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Xylanase plays an important role in the food, feed, and pulp/paper industry. Filamentous fungi have been considered as useful producers of this enzyme from an industrial point of view, due to the fact that they excrete xylanases into the medium. In this study, four fungal species belonging to different genera, i.e. Aspergillus, Cochliobolus, Pyrenophora, and Penicillium were isolated from different sources and compared for their ability to produce xylanase in submerged culture. The fungal species showed enzyme activity as determined by dinitrosalicylic acid (DNS) method. It was found that the two saprophytic Aspergillus strains, i.e A. terreus (Fss 129) and A. niger (SS7) had the highest xylanase activity of 474 and 294 U ml–1 at pH 7 and 8, respectively, in the presence of corn cob hulls after 120 h of incubation. The production of xylanase seemed to be strongly influenced by the interactive effect of initial pH on the fungi. Interestingly, xylanase was better produced by the saprophytic fungi of Aspergillus and Penicillium than by the plant pathogenic ones of Cochliobolus and Pyrenophora. This work provides additional information to support future research on fungi with different lifestyles for food industrial production of xylanase.

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