Wyniki wyszukiwania - Biblioteka Nauki

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Optimization and evaluation of alkali-pretreated Paeonia ostii seed coats as adsorbent for the removal of MB from aqueous solution

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Liu Q. , Li T. , Zhang S. , Qu L. , Ren B.

Polish Journal of Chemical Technology

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2018

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tom Vol. 20, nr 3

29--36

EN

A novel efficient adsorbent, alkali-pretreated Paeonia ostii seed coats (AP-PSC), was investigated for the removal of methylene blue (MB) dye from solution. Orthogonal array design was applied to optimize the process parameters viz. alkali concentration, liquid-solid ratio (LSR) and pretreatment time. The results revealed that the optimal pretreatment conditions were at 0.8% (w/w) NaOH with LSR of 0.35 L g–1 treating for 50 min. Equilibrium and kinetic studies indicated that Langmuir isotherm and Pseudo-second-order models described the experimental data well. The maximum adsorption capability was of 368.2 mg g–1 for MB at 25°C. Thermodynamic parameters suggested that the AP-PSC adsorption process was physical, endothermic and spontaneous. Furthermore, the adsorption process was influenced by several interactive mechanisms, including ion-exchange, as well as Van der Waals forces and hydrogen bonds that occur concomitantly. It was concluded that AP-PSC may be potential as an efficient adsorbent to remove MB from solution.

2

Preparation and Properties of Natural Cellulose Fibres from

86%

Qu L. , Tian M. , Guo X. , Pan N. , Zhang X. , Zhu S.

Fibres & Textiles in Eastern Europe

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2014

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tom Vol. 22, no. 4 (106)

24--28

EN

Natural cellulose fibres from Broussonetia papyrifera (L.) Vent. (BP) bast were systematically investigated in this paper. To begin with, BP fibres were successively extracted from BP bast by four different degumming methods, among which the microwave-assisted method exhibited high efficiency. It was found that non-cellulose substances were sufficiently removed or reduced after the degumming process, but the cellulose I structure had not changed from bast to fibres based on the XRD and FTIR results. Meanwhile the BP fibres exhibited high crystallinity (75 ~ 77%), high breaking strength (2.19 ~ 2.39 cN/dtex) and a remarkable moisture region (6.3 ~ 8.7%), but low breaking elongation (1.0 ~ 2.1%). All those results indicated that the BP fibres had properties resembling those of traditional natural cellulose fibres (e.g. cotton and flax); therefore they could be viewed as a promising alternative source for natural cellulose bundle fibres.

PL

Artykuł poświecono systematycznym badaniom naturalnych włókien celulozowych z Broussonetia Papyrifera (BP). Włókna ekstrahowano z włókien łykowych BP poprzez 4 rożne metody odpreparowania pomiędzy z których metoda za pomocą zastosowania ultradźwięków pozwoliła na uzyskanie wysokiej wydajności. Stwierdzono, że nie celulozowe substancje były dostatecznie usunięte lub zredukowane po procesie odpreparowania. Dzięki badaniom XRD i FITR można było wykazać, że struktura celulozy (I) nie zmieniła się pomiędzy włóknami łykowymi i otrzymanymi z nich wyrobami. dalsze badania wykazały źe włókna BP maja wysoką krystaliczność (75 - 77%), wysoką wytrzymałość(2.19 - 2.39 cN/dtex) i znaczną pochłanialność wilgoci (6.3 - 8.7%) natomiast małe wydłużenie przy zerwaniu (1.0 - 2.1%). Wszystkie te wyniki wskazują,że włókna BP posiadają właściwości przypominające właściwości tradycyjnych, naturalnych włókien celulozowych (np. bawełny i lnu). Dlatego też badane włok-na można uważać jako alternatywne źródło naturalnych włókien celulozowych.

3

Heat shock protein 27 plays a protective role in thoracic aortic dissection by promoting cell proliferation and inhibiting apoptosis

86%

Zou S. , Liao M. , Yang J. , Huang T. , Green M. , Wu J. , Qu L.

Cellular and Molecular Biology Letters

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2017

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tom 22

4

Downregulation of the lycopene ε-cyclase gene confers tolerance to salt and drought stress in Nicotiana tabacum

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Shi J. , Liu P. , Xia Y. , Wei P. , Li W. , Zhang W. , Chen X. , Cao P. , Xu Y. , Jin L. , Li F. , Luo Z. , Wei C. , Zhang J. , Xie X. , Qu L. , Yang J. , Lin F. , Wang R.

Acta Physiologiae Plantarum

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2015

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tom 37

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nr 10

EN

Lycopene ε-cyclase (ε-LCY) functions at a branch point of the carotenoid biosynthesis pathway and modulates the ratio of lutein to the β-carotenoids. RNA interference (RNAi) and overexpression (OE) of Ntε-LCY were used to evaluate the physiological roles of ε-LCY in Nicotiana tobacum. In leaves, strong accumulation of β branch carotenoids and high expression of carotenoid biosynthesis genes resulted from suppression of Ntε-LCY expression. RNAi plants showed enhanced salt and drought tolerance, while overexpression of the Ntε-LCY gene weakened tolerance to salt and drought stress, as compared to control. Further analysis revealed that RNAi plants exhibited less water loss and had lower reactive oxygen species levels than did WT plants after both the salt and drought treatments. Further, higher levels of ABA accumulated in the RNAi lines than in the WT lines under stress conditions. These results suggest that reduced Ntε-LCY expression can improve drought and salinity tolerance in Nicotiana tabacum by enhancing their ROS scavenging ability.