Wyniki wyszukiwania - Biblioteka Nauki

1

Application of dispersive liquid—liquid microextraction for the analysis of organophosphorus pesticides in Hawthorn (Crataegus pinnatifida var. major) juice samples

100%

Ren Q. , Xia T.

Acta Chromatographica

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2016

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tom Vol. 28, no. 3

403--414

EN

Dispersive liquid–liquid microextraction (DLLME) coupled with gas chromatography equipped with flame photometric detection (GC—FPD) is introduced to extract and determine the fifteen organophosphorus pesticides (OPPs) in hawthorn (Crataegus pinnatifida var. major) juice samples. Some parameters affecting the DLLME efficiency, such as the type and volume of extraction and dispersive solvents, extraction time, and salt concentration, were studied and optimized. The optimized extraction and dispersive solvents are trichloroethane and acetonitrile, respectively. Good linearity was ranged from 0.5 to 100 ng mL−1 with correlation coefficients from 0.9991 to 0.9999. The limits of quantification (LOQs) varied from 0.15 to 0.3 ng mL−1, and the limits of detections (LODs) ranged from 0.05 to 0.1 ng mL−1. The relative standard deviations (RSDs) varied from 1.0% to 2.8% (n = 6) with the relative recoveries in the range of 85.6–119.1%. The method was successfully applied in the determination of OPPs in ten commercial hawthorn juice samples. The chlorpyrifos was detected in one sample.

2

Influence of fitting and differentiation algorithms on the determination of kinetic parameters for atom formation in GFAAS

100%

Yan-Zhong L. , Xia T.

Chemia Analityczna

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2000

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tom Vol. 45, No. 1

83-96

EN

Different approaches for data treatment, the orthogonal polynomial regression and cubic spline function used in the calculation of kinetic parameters in GFAAS, were compared. The determination of activation energy and release order was based on the method pro-posed in our laboratory. The experimental data for thallium, obtained from probe atom-ization were utilized in the comparison. The results show that the use of polynomial regressions tends to yield larger values of kinetic order and activation energy as com-pared to that of cubic spline function, and the kinetic orders determined are less tempera-ture dependent, while the values of the order in the latter case decrease with the increase of temperature. The orders and activation energies for thallium obtained in this experi-ment are 0.33 + 0.02 and 83 š 2 kJ mol-1, 0.38 š 0.07 and 88 + 5 kJ mol'-1 and 0.17 + 0.04 and 68 š 4 kJ moP1 for 6th-order polynomial, 9th-order polynomial and cubic spline function, respectively.

PL

Porównano dwie metody w analizie danych GFAAS. Pierwsza metoda wykorzystuje wielomiany ortogonalne, a druga złożone wielomiany trzeciego stopnia. Do porównania wzięto dane uzyskane dla atomizacji talu. Otrzymane wyniki wskazują, że pierwsza metoda prowadzi do wyższych wartości energii aktywacji i rzędu reakcji oraz do-datkowo rząd reakcji tak wyznaczony jest mniej zależny od temperatury w porównaniu do drugiej reakcji. Uzyskano następujące rzędy reakcji: 0.33 š0.02 i 83 š 2 kJ mol-1; 0.38 š 0.07 i 88 š 5 kJ mol-1; 0.17 š 0.04 i 68 š 4 kJ mol-1 odpowiednio dla wielomianu 6-stopnia, 9-stopnia i złożonej funkcji 3-stopnia.

3

Antileukemic activity of the chemical constituents from Scutellaria barbata D. Don

70%

Ren Q. , Xia T. , Quan X. G. , Ding L. , Wang H. Y.

Acta Chromatographica

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2017

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tom Vol. 29, no. 3

399--413

EN

Scutellaria barbata D. Don has been used as a traditional Chinese medicine for antitumor and anti-inflammatory. However, there were just a few investigations about S. barbata D. Don according to bioactivity-directed isolation and online identification for the chemical constituents. In this work, eight compounds were isolated from S. barbata D. Don. The three flavonoids indicated the cytotoxic activity against human leukemic Reh cell lines. In addition, the constituents of S. barbata D. Don were further characterized and identified by ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOF-MS). The UHPLC- Q-TOF-MS method was in negative ion mode. HPLC separation was performed on a Tosoh TSK gel ODS-100V (4.6 × 150 mm, 3.0 μm) column by gradient elution using water containing 0.3% formic acid and acetonitrile as mobile phase at a flow rate of 0.8 mL min−1. A total of 18 compounds, including 4 phenolic acids and 14 flavonoids were tentatively characterized and identified by means of the retention time, accurate mass, and characteristic fragment ions.

4

Molecular characterization, expression profiles, and association analysis with hematologic parameters of the porcine HPSE and HPSE2 genes

51%

Tao C. , Wang W. , Zhou P. , Xia T. , Zhou X. , Zeng C. , Zhang Q. , Liu B.

Journal of Applied Genetics

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2013

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tom 54

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nr 1

EN

Heparan sulfate (HS), which consists of repeating disaccharide units, plays an essential role in inflammation and viral infections. Heparanase (encoded by the HPSE gene) can cleave the HS chains of heparan sulfate proteoglycans (HSPGs), which are known to be important participants in immune responses. HPSE2 (heparanase 2) is a homologous gene of HPSE. To investigate the functions of HS, which is the primary receptor of the porcine reproductive and respiratory syndrome virus (PRRSV), the two genes involved in the metabolic process of HS were studied. Here, we present a study of tissue expression profiles, polymorphisms of the HPSE and HPSE2 genes, and the changes of their mRNA levels in porcine alveolar macrophages (PAMs) induced by PRRSV. Both genes are preferentially expressed in porcine immune or immune-related organs under normal conditions, e.g., in the lung, spleen, and lymph node. Moreover, a synonymous mutation c.750A>G located in exon5 of the HPSE gene was detected, and was significantly associated with the white blood cell (WBC) count, red blood cell (RBC) count, hemoglobin (HGB), and hematocrit (HCT) in the peripheral blood (p<0.05). A single nucleotide polymorphism (SNP) c.2073A>G was found in the HPSE2 gene and association analysis showed that it was significantly associated with the WBC content in the blood (p<0.05). Upon stimulation in healthy piglets with PRRSV, the HPSE mRNA was obviously up-regulated, while the HPSE2 mRNA did not induce a prominent change in PAMs.

5

High-throughput sequencing analysis of endophytic bacteria diversity in fruits of white and red pitayas from three different origins

41%

Ren Z. , Tang S. , Jiang Y. , Jiang M. , Zheng S. , Liu W. , Yang Z. , Sang S. , Chen Z. , Xia T. , Yin M.

Polish Journal of Microbiology

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2018

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tom 67

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nr 1

EN

Pitaya contains various types of polyphenols, flavonoid and vitamins which are beneficial for health and it is among the most important commercial tropical fruits worldwide. Endophytic bacteria might be beneficial for plant growth and yield. However, bacterial diversity in pitaya is poorly characterized. In this study, fruits of white and red pitayas from three different origins (Thailand, Vietnam and China) were chosen for endophytic bacteria diversity investigation by using Illumina HiSeq second-generation high-throughput sequencing technology. Large number of endophytic bacteria were detected and 22 phyla, 56 classes, 81 orders, 122 families and 159 genera were identified. Endophytic bacteria diversity was uneven among pitaya fruits from different origins and bacteria structure was different between white pitaya group and red pitaya group. Phylum Bacteroidetes, classes Bacteroidia and Coriobacteriia, orders Bacteroidales and Coriobacteriales, families Prevotellaceae, Bacteroidaceae, Ruminococcaceae, Paraprevotellaceae, Rikenellaceae, Alcaligenaceae and Coriobacteriaceae, genera Prevotella, Bacteroides, Roseburia, Faecalibacterium and Sutterella were statistically significant different species (P < 0.05) between white and red pitayas. These findings might be useful for growth improvement, fruit preservation and processing of different pitaya species from different origins.