959 research outputs found
Cell membrane permeability and antioxidant activities in the rootstocks of Miscanthus x giganteus as an effect of cold and frost treatment
The aim of the study was to estimate the ability of Miscanthus x giganteus to acquire frost tolerance. Field grown rootstocks were transferred into pots and cultivated in a glasshouse at 20°C. After 5 weeks plants were pre-hardened at 12°C for a further 2 weeks and then hardened at 5°C for another 3 weeks. After this time, plants were frozen at -8°C or -15°C for 1, 3 or 5 days, after which their regrowth at 20°C was investigated. The membrane permeability (electrolyte leakage), activity of the catalase (CAT), non-specific peroxidase (PX), and protein content in stolons were measured, before and after pre-hardening, as well as after hardening and freezing. Both pre-hardening and hardening decreased membrane permeability of the rootstock cells, and this effect was observed further, after 5-week of regrowth at 20°C. Freezing at both temperatures increased ion leakage gradually over the period of treatment. On the basis of total ion content, damage to the cell membranes of frozen stolons after recovery was state. Prehardening increased CAT activity, while hardening did not alter it. However, after 5-week de-hardening, CAT activity decreased significantly. Freezing at -8°C for 5 days increased significantly the activity of this enzyme. At -15°C CAT activity was lower than in the control after only one day of freezing. PX activity decreased both in the rootstocks of cold (12°C and 5°C) and frost treated plants. Protein content increased significantly in the stolons of both pre-hardened and hardened plants, although not immediately after cold treatment, but only after a 5-week re-growth period in a glasshouse at 20°C. This phenomenon was observed also in the stolons of plants frozen at -15°C for 5 days. From frozen rootstocks no new stems in regrowth conditions were obtained. The results obtained indicated, that although frozen stolons cannot produce new shoots, they do demonstrate some metabolic vitality. So, it could be supposed that the frost susceptibility of studied plants resulted from the strong sensitivity of shoot apical meristems to the cold. Further studies will analyse the survival of Miscanthus in milder frost temperatures
Automatic method for detection of characteristic areas in thermal face images
The use of thermal images of a selected area of the head in screening systems,
which perform fast and accurate analysis of the temperature distribution of individual areas,
requires the use of profiled image analysis methods. There exist methods for automated face
analysis which are used at airports or train stations and are designed to detect people with
fever. However, they do not enable automatic separation of specific areas of the face. This
paper presents an algorithm for image analysis which enables localization of characteristic
areas of the face in thermograms. The algorithm is resistant to subjects’ variability and also to
changes in the position and orientation of the head. In addition, an attempt was made to
eliminate the impact of background and interference caused by hair and hairline. The algorithm
automatically adjusts its operation parameters to suit the prevailing room conditions.
Compared to previous studies (Marzec et al., J Med Inform Tech 16:151–159, 2010), the set
of thermal images was expanded by 34 images. As a result, the research material was a total of
125 patients’ thermograms performed in the Department of Pediatrics and Child and
Adolescent Neurology in Katowice, Poland. The images were taken interchangeably with
several thermal cameras: AGEMA 590 PAL (sensitivity of 0.1 °C), ThermaCam S65
(sensitivity of 0.08 °C), A310 (sensitivity of 0.05 °C), T335 (sensitivity of 0.05 °C) with a
320×240 pixel optical resolution of detectors, maintaining the principles related to taking
thermal images for medical thermography. In comparison to (Marzec et al., J Med Inform Tech
16:151–159, 2010), the approach presented there has been extended and modified. Based on
the comparison with other methods presented in the literature, it was demonstrated that this
method is more complex as it enables to determine the approximate areas of selected parts of the face including anthropometry. As a result of this comparison, better results were obtained
in terms of localization accuracy of the center of the eye sockets and nostrils, giving an
accuracy of 87 % for the eyes and 93 % for the nostrils
Influence of iron aggregation on the catalytic performance of desilicated MFI in the DeNO(x) process
[EN] In the present study, an influence of the iron aggregation in conventional and micro-mesoporous MFI on their catalytic activity in the NO reduction with ammonia (DeNO(x) process) was studied. Modification of MFI zeolite properties was done by the desilication in the presence of NaOH and TPAOH (tertapropylammonium hydroxide). In the next step, the samples were modified with iron by ion-exchange with the use of a conventional solution of Fe cations (FeSO4) and a solution of iron triple-metallic aggregates (oligocations) ([Fe-3(OAc)(6)O(H2O)(3)](+)). Both of the applied modification techniques (desilication and modification with Fe-3 oligocations) increased the catalytic activity of the MFI zeolite in the DeNO(x) process. This increased catalytic activity was connected with changes in sample porosity, Si/Al ratio, topology, as well as aggregation and dispersion of iron species on the catalyst surface, which was investigated by N-2-sorption, XRD, ICP, NMR, HRTEM and UV-vis-DRS techniques.This work was carried out in the frame of project No. 0670/IP3/2016/74 from the Polish Ministry of Science and Higher Education in the years 2016-2019 and in the frame of project No. 2012/05/B/ST5/00269 from the National Science Centre (Poland). U. D. acknowledges to the Spanish Government by the funding (MAT2017-82288-C2-1-P).Rutkowska, M.; Borcuch, A.; Marzec, A.; Kowalczyk, A.; Samojeden, B.; Moreno, J.; Díaz Morales, UM.... (2020). Influence of iron aggregation on the catalytic performance of desilicated MFI in the DeNO(x) process. Microporous and Mesoporous Materials. 304:1-8. https://doi.org/10.1016/j.micromeso.2018.09.015S1830
Selective ammonia oxidation over ZSM-5 zeolite: Impact of catalyst's support porosity and type of deposited iron species
[EN] In the presented studies an influence of different parameters, such as zeolite sample porosity, form of used iron source ([Fe-3(OAc)(6)O(H2O)(3)](+)oligocations or FeSO4 solutions) and method of iron species deposition (ion-exchange, impregnation), on the catalytic activity in the process of the selective catalytic oxidation of ammonia (NH3-SCO) was studied. Conventional and mesoporous ZSM-5 zeolites, obtained by desilication and modified with iron species, were analysed with respect to their textural, surface and crystalline properties (N-2-sorption, HRTEM, SEM, XRD) as well as the form of introduced Fe species (UV-vis-DRS). Ion-exchange with [Fe-3(OAc)(6)O (H2O)(3)](+) oligocations and impregnation with these oligocations and FeSO4 solutions were found as the most effective methods of the zeolite samples activation for NH3-SCO.This work was carried out in the frame of project No. 0670/IP3/2016/74 from the Polish Ministry of Science and Higher Education in the years 2016-2019. Part of the work was performed in the frame of project No. 2012/05/B/ST5/00269from the National Science Centre (Poland).
U. D. acknowledges to the Spanish Government by the funding (MAT2017-82288-C2-1-P). The authors would like to acknowledge to Clariant Company for the providing of the HMFI zeolite material for the presented research.Borcuch, A.; Rutkowska, M.; Marzec, A.; Kowalczyk, A.; Michalik, M.; Moreno, J.; Díaz Morales, UM.... (2020). Selective ammonia oxidation over ZSM-5 zeolite: Impact of catalyst's support porosity and type of deposited iron species. Catalysis Today. 348:223-229. https://doi.org/10.1016/j.cattod.2019.08.054S223229348Weckhuysen, B. M., & Yu, J. (2015). Recent advances in zeolite chemistry and catalysis. Chemical Society Reviews, 44(20), 7022-7024. doi:10.1039/c5cs90100fVerboekend, D., & Pérez-Ramírez, J. (2011). Design of hierarchical zeolite catalysts by desilication. Catalysis Science & Technology, 1(6), 879. doi:10.1039/c1cy00150gRutkowska, M., Pacia, I., Basąg, S., Kowalczyk, A., Piwowarska, Z., Duda, M., … Chmielarz, L. (2017). Catalytic performance of commercial Cu-ZSM-5 zeolite modified by desilication in NH 3 -SCR and NH 3 -SCO processes. Microporous and Mesoporous Materials, 246, 193-206. doi:10.1016/j.micromeso.2017.03.017Góra-Marek, K., Brylewska, K., Tarach, K. A., Rutkowska, M., Jabłońska, M., Choi, M., & Chmielarz, L. (2015). IR studies of Fe modified ZSM-5 zeolites of diverse mesopore topologies in the terms of their catalytic performance in NH3-SCR and NH3-SCO processes. Applied Catalysis B: Environmental, 179, 589-598. doi:10.1016/j.apcatb.2015.05.053Macina, D., Piwowarska, Z., Góra-Marek, K., Tarach, K., Rutkowska, M., Girman, V., … Chmielarz, L. (2016). SBA-15 loaded with iron by various methods as catalyst for DeNOx process. Materials Research Bulletin, 78, 72-82. doi:10.1016/j.materresbull.2016.02.026Rutkowska, M., Duda, M., Macina, D., Górecka, S., Dębek, R., Moreno, J. M., … Chmielarz, L. (2019). Mesoporous Beta zeolite functionalisation with FexCry oligocations; catalytic activity in the NH3SCO process. Microporous and Mesoporous Materials, 278, 1-13. doi:10.1016/j.micromeso.2018.11.003Miller, J. T., Glusker, E., Peddi, R., Zheng, T., & Regalbuto, J. R. (1998). Catalysis Letters, 51(1/2), 15-22. doi:10.1023/a:1019072631175Kowalczyk, A., Borcuch, A., Michalik, M., Rutkowska, M., Gil, B., Sojka, Z., … Chmielarz, L. (2017). MCM-41 modified with transition metals by template ion-exchange method as catalysts for selective catalytic oxidation of ammonia to dinitrogen. Microporous and Mesoporous Materials, 240, 9-21. doi:10.1016/j.micromeso.2016.11.002Chmielarz, L., & Jabłońska, M. (2015). Advances in selective catalytic oxidation of ammonia to dinitrogen: a review. RSC Advances, 5(54), 43408-43431. doi:10.1039/c5ra03218kThommes, M., Kaneko, K., Neimark, A. V., Olivier, J. P., Rodriguez-Reinoso, F., Rouquerol, J., & Sing, K. S. W. (2015). Physisorption of gases, with special reference to the evaluation of surface area and pore size distribution (IUPAC Technical Report). Pure and Applied Chemistry, 87(9-10), 1051-1069. doi:10.1515/pac-2014-1117Qi, G., & Yang, R. T. (2005). Selective catalytic oxidation (SCO) of ammonia to nitrogen over Fe/ZSM-5 catalysts. Applied Catalysis A: General, 287(1), 25-33. doi:10.1016/j.apcata.2005.03.00
Dysregulation of autophagy in human follicular lymphoma is independent of overexpression of BCL-2
Mild hydration of didecyldimethylammonium chloride modified DNA by 1H-nuclear magnetic resonance and by sorption isotherm
The gaseous phase hydration of deoxyribonucleic acid and didecyldimethylammonium chloride (C19H42ClN) complexes (DNA-DDCA) was observed using hydration kinetics, sorption isotherm, and high power nuclear magnetic resonance. Three bound water fractions were distinguished: (i) a very tightly bound water not removed by incubation over silica gel, (ii) a tightly bound water saturating with the hydration time t(1)(h) (0.596 +/- 0.04) h, and a loosely bound water fraction, (iii) with the hydration time t(2)(h) (20.9 +/- 1.3) h. Proton free induction decay was decomposed into the signal associated with the solid matrix of DNA-DDCA complex (T-2S approximate to 30 mu s) and two liquid signal components coming from tightly bound (T-2L1 approximate to 100 mu s) and from loosely bound water fraction (T-2L2 approximate to 1000 mu s)
Rehydration of CTMA modified DNA powders observed by NMR
The rehydration of salmon sperm deoxyribonucleic acid (DNA) and cetyltrimethylammonium chloride complexes was observed using hydration kinetics, sorption isotherm, and high power proton relaxometry (at 30 MHz). The hydration kinetics shows (i) a very tightly bound water not removed by incubation over silica gel ( = 0.061 ± 0.004), (ii) a tightly bound water saturating at = 0.039 ± 0.011, with the hydration time = (1.04 ± 0.21) h, a loosely bound water fraction (iii) with the hydration time = (19.1 ± 3.2) h and the contribution progressively increasing with the air humidity. For the hydration at = 100%, after = (152.6 ± 2.5) h of incubation the swelling process begins. The swelling time was = (12.5 ± 5.4) h, and the swelling amplitude = 0.140 ± 0.016. The sorption isotherm is sigmoidal in form and is fitted by the Dent model with the mass of water saturating primary binding sites Δ M/ = 0.102 ± 0.021. Proton free induction decay is a superposition of the immobilized proton signal (Gaussian, with * ≈ 30 μs) and two liquid signal components coming from tightly bound (* ≈ 100 μs) and loosely bound water fraction with the amplitude proportional to the mass of water added (* ≈ 1000 μs)
Disordered Filaments Mediate the Fibrillogenesis of Type I Collagen in Solution
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