Wyniki wyszukiwania - Biblioteka Nauki

1

Crystallization and melting behavior of poly(L-lactic acid) modified with salicyloyl hydrazide derivative

100%

Cai Y.-H. , Tian L. , Tang Y.

Polimery

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2017

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tom T. 62, nr 10

734--742

EN

This work evaluated the influence of a novel organic nucleating agent, salicyloyl hydrazide derivative (BS), on the crystallization and melting behavior of poly(L-lactic acid) (PLLA). Differential scanning calorimetry revealed that the incorporation of BS (0.2 to 3 wt %) significantly promoted the crystallization of PLLA on cooling at 1 °C/min. At BS content of 1.5 wt % in PLLA matrix, the highest effectiveness of crystallization process was observed, this result was further demonstrated by X-ray diffraction analysis of non-isothermal crystallization behavior at different cooling rate and measurements after isothermal crystallization. X-ray diffraction studies showed also that the addition of BS did not change the crystalline structure of PLLA. Based on the effect of the predetermined melting temperature on the crystallization behavior of PLLA/BS, the optimum process temperature of 190 °C was found. The comparative study on the melting behavior of PLLA/BS composite under different conditions (cooling rate, melting temperature) also confirmed the ability of BS to promote the nucleation of PLLA crystallization. The crystallization of PLLA/BS composite depends on the concentration of BS additive, crystallization temperature and time as well as heating rate.

PL

Badano wpływ nowego organicznego czynnika nukleującego, salicyloilowej pochodnej hydrazydu (BS), na krystalizację i topnienie poli(kwasu L-mlekowego) (PLLA). Na podstawie badań metodą różnicowej kalorymetrii skaningowej stwierdzono, że wprowadzenie dodatku BS (0,2–3,0 % mas.) wyraźnie promuje krystalizację PLLA w warunkach chłodzenia z szybkością 1 °C/min. Zawartość 1,5 % mas. BS w osnowie PLLA przyczyniała się do zwiększenia efektywności procesu krystalizacji, co potwierdziły wyniki badań metodą dyfrakcji rentgenowskiej krystalizacji nieizotermicznej w warunkach zmiennej szybkości chłodzenia oraz krystalizacji izotermicznej. Ponadto badania te wykazały, że dodatek BS do PLLA nie zmienia struktury krystalicznej poli(kwasu L-mlekowego). Na podstawie wpływu ustalonych warunków topnienia na przebieg krystalizacji PLLA/BS stwierdzono też, że optymalna temperatura tego procesu wynosi 190 °C. Badania porównawcze topnienia kompozytu PLLA/BS w różnych warunkach (szybkości chłodzenia, temperatury topnienia) również wskazują na zdolność BS do zarodkowania krystalizacji PLLA. Stwierdzono, że krystalizacja kompozytu PLLA/BS zależy od stężenia dodatku BS, temperatury krystalizacji, czasu krystalizacji i szybkości ogrzewania próbki.

2

Extreme points and support points of a class of analytic functions with missing coefficients

100%

Xiong L. , Tian L. , Luo S. , Liu X.

Demonstratio Mathematica

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2013

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tom Vol. 46, nr 3

525--532

EN

Let Mn(a, b, c) denote a class of functions of the form (...) which are analytic in open unit disk (...) and satisfy the condition (...). In this paper, we obtain the extreme points and support points of the class Mn(a, b, c) of functions.

3

Assessing synergistic ultrafiltration membrane fouling by TiO2 nanoparticles and humic acid using interaction energy analysis

88%

Tian L. , Sun C. , Sun F. , Zong R. , Liang S.

Polish Journal of Environmental Studies

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2017

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tom 26

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nr 5

EN

This research attempts to elucidate the effect of humic acid (HA) on TiO₂ nanoparticle ultrafiltration (UF) membrane fouling, and quantitatively analyze the synergistic membrane fouling mechanisms using interaction energies. The extended Derjaguin-Landau-Verwey-Overbeek (xDLVO) theory was employed to analyze the interaction energies and predict UF membrane fouling. Membrane fouling effects were studied during the dead-end filtration of individual TiO₂ and HA-TiO₂ mixtures using two kinds of polymeric UF membranes. It was found that HA-TiO₂ mixtures lead to greater flux declines than individual TiO₂ . For specific foulant, the hydrophobic PVDF membrane showed relative severe membrane fouling than hydrophilic PES membrane. As for the HA-TiO₂ mixture, much higher irreversible fouling was observed compared with that of individual TiO₂ . Moreover, this study highlights the importance of HA concentration in synergistic fouling effects of the HA-TiO₂ mixture. The increase of HA concentration caused an increase of contact angle and lower interaction energy, thus aggravating membrane fouling. Results illustrated that synergistic membrane fouling by TiO₂ and HA could be successfully explained using the xDLVO analysis. The extent of membrane fouling turned out to be dominated by Lewis acid-base interaction.

4

Analysis of alkaloids in pharmaceutical preparations containing Kushen by capillary electrophoresis with application of experimental design and a quantitative structure-property relationship approach

88%

Wen Y. , Liu H. , Tian L. , Han P. , Luan F.

Acta Chromatographica

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2010

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tom Vol. 22, no. 3

445--457

EN

A simple and rapid capillary electrophoretic procedure for analysis of matrine and oxymatrine in Kushen medicinal preparations has been developed and optimized. Orthogonal design was used to optimize the separation and detection conditions for the two active components. Phosphate concentration, applied potential, organic modifier content, and buffer pH were selected as variable conditions. The optimized background electrolyte contained 70 mM sodium dihydrogen phosphate and 30% acetonitrile at pH 5.5; the separation potential was 20 kV. Each analysis was complete within 5 min. Regression equations revealed linear relationships ( r > 0.999) between peak area and amount for each component. The detection limits were 1.29 μg mL -1 for matrine and 1.48 μg mL -1 for oxymatrine. The levels of the two active compounds in two kinds of traditional Chinese medicinal preparation were easily determined with recoveries of 96.57–106.26%. In addition, multiple linear regression and a non-linear model using a radial basis function neural network approach were constructed for prediction of the migration time of oxymatrine. The predicted results were in good agreement with the experimental values, indicating that a radial basis function neural network is a potential means of prediction of separation time in capillary electrophoresis.

5

Effects of waterlogging stress on the physiological response and grain-filling characteristics of spring maize (Zea mays L.) under field conditions

88%

Tian L. , Bi W. , Liu X. , Sun L. , Li J.

Acta Physiologiae Plantarum

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2019

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tom 41

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nr 05

EN

A field experiment was implemented to discuss the effects of waterlogging and subsurface waterlogging stress on the grain yield, grain-filling characteristics, superoxide anion (O⋅−₂) content, hydrogen peroxide (H₂O₂) content, malondialdehyde (MDA) content, antioxidant enzyme activity, proline, soluble protein content and SPAD value of the spring maize (Zea mays L.) hybrids “Demeiya1” (DMY1) and “Keyu16” (KY16). The waterlogging and subsurface waterlogging treatments were conducted for different durations (3, 6, and 9 days and 5, 10, and 15 days, respectively) at the seedling (V3), jointing (V6), and tasseling (VT) stages. The results showed that the most significant effects of waterlogging and subsurface waterlogging stress occurred at the V3 stage, followed by the V6 stage and then VT stage. Waterlogging and subsurface waterlogging caused a decline in grain filling, which resulted in a decline in grain weight and ultimately caused an obvious decrease in yield. The content of O⋅−₂ and H₂O₂ as well as MDA increased with the prolongation of the duration of waterlogging and subsurface waterlogging, which caused an up-regulation of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) activities, as well as increased proline and soluble protein contents and decreased SPAD value. In addition, we also demonstrated that KY16 is more sensitive than DMY1 to waterlogging and subsurface waterlogging.

6

Discoloration of Cotton/Kapok Indigo Denim Fabric by Using a Carbon Dioxide Laser

75%

Du W. , Gosh R. C. , Zuo D.-Y. , Zou H.-T. , Tian L. , Yi C.-H.

Fibres & Textiles in Eastern Europe

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2016

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tom Vol. 24, no. 4 (118)

63--67

EN

In this work, a carbon dioxide laser was used for the color-fading treatment of cotton/kapok denim fabrics. The results were analyzed thoroughly and compared with those of cotton denim fabric and PET denim fabric. Results showed that with laser treatment, the fabrics were colour-faded, and the K/S value of cotton/kapok fabric was reduced, while there was little change in the thickness and permeability. Because the internal air of the kapok fiber was squeezed out, the tensile strength of the fabric was decreased. The influence of laser power and speed on the kapok denim was also investigated. With an increase in the laser power and decrease in the speed, both the K/S values and strength decreased significantly. However, the changes were negligible for the thickness and permeability of the cotton/kapok denim fabric. It is therefore concluded that kapok is a good denim fabric material for the laser process.

PL

Wyniki analizowano i porównywano z wynikami uzyskiwanymi z tkanin denim z bawełny i PET. Wyniki wykazały, że przy zastosowaniu lasera zredukowano intensywność koloru, a wartość K/S została zredukowana przy małych zmianach grubości i przepuszczalności powietrza. Ponieważ wewnętrzne powietrze zawarte we włóknach kapoku było wyciskane na zewnątrz, wytrzymałość tkanin została zmniejszona. Badano również wpływ mocy lasera oraz szybkości przesuwania tkaniny denim na wartość KS i wytrzymałość. Stwierdzono, że wraz ze wzrostem mocy lasera i zmniejszeniem szybkości przesuwu tkaniny zarówno wartość KS jak i wytrzymałość zostały znacznie zmniejszone. Jednakże, zmiany grubości i przepuszczalności powietrza były minimalne. Stwierdzono, że włókna kapok są dobrym materiałem do tkanin typu denim.

7

Sirolimus in transplantation

75%

Stepkowski S. M. , Tian L. , Wang M. E. , Qu X. , Napoli K. , Kahan B. D.

Archivum Immunologiae et Therapiae Experimentalis

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1997

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tom 45

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nr 5-6

8

Serological and molecular evidence of Coxiella burnetii in samples from humans and animals in China

63%

El-Mahallawy H. S. , Kelly P. , Zhang J. , Yang Y. , Wei L. , Tian L. , Fan W. , Zhang Z. , Wang C.

Annals of Agricultural and Environmental Medicine

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2016

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tom 23

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nr 1

9

Sp100 interacts with phage ΦC31 integrase to inhibit its recombination activity

63%

Lin Y. , Li Z. , Wang J. , Xu G. , Shen Q. , Tian L. , Xue J. , Chen J.

Acta Biochimica Polonica

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2011

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tom 58

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nr 1

EN

Phage ΦC31 integrase is a potential vector for the insertion of therapeutic genes into specific sites in the human genome. To understand the mechanism involved in ΦC31 integrase-mediated recombination, it is important to understand the interaction between the integrase and cellular proteins. Using a yeast two-hybrid system with pLexA-ΦC31 integrase as bait, we screened a pB42AD human fetal brain cDNA library for potential interacting cellular proteins. From the 106 independent clones that were screened, 11 potential interacting clones were isolated, of which one encoded C-terminal fragment of Sp100. The interaction between Sp100 and ΦC31 integrase was further confirmed by yeast mating and co-immunoprecipitation assays. The hybridization between a ΦC31 integrase peptide array and an HEK293 cell extract revealed that residues 81RILN84 in the N-terminus of ΦC31 integrase are responsible for the interaction with Sp100. Knocking down endogenous Sp100 with Sp100-specific siRNA increased ΦC31 integrase-mediated recombination but did not impact reporter gene expression. Therefore, endogenous Sp100 may interact with ΦC31 integrase and inhibit the efficiency of ΦC31 integrase-mediated recombination.

10

Epac1 is involved in cell cycle progression in lung cancer through PKC and Cx43 regulation

51%

Sun Q. , Wang D. , Ai G. , Tian L. , Zhao L. , Chen R. , Wang K. , Guo D. , Yao Y. , Liu W. , Kong X. , Chen X. , Zhang Y.

Folia Histochemica et Cytobiologica

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2018

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tom 56

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nr 1