Time filter

Source Type

Qiao X.-Y.,Zhejiang University | Dai L.-K.,Zhejiang University | Wu J.-J.,Zhejiang Entry Exit Inspection and Quarantine Bureau
Guang Pu Xue Yu Guang Pu Fen Xi/Spectroscopy and Spectral Analysis | Year: 2010

According to the characteristics of the textile fibers Raman spectra, a qualitative identification method based on Raman feature extraction is proposed. This fast method consists of spectrum measurement and spectral data processing algorithm, including spectrum preprocessing, feature extraction and matching recognition. It can be used to identify the components of fibers or fabrics, especially chemical fibers, which is an inspective difficulty in daily analytic work for its remarkable Raman feature. The authors performed an experiment to analyze 4 typical and widely used kinds of fibers as algorithm verification. They are terylene fiber, acrylic fiber, nylon fiber and rayon fiber. To identify the components of one test sample, first the authors set up feature tables of these 4 standard samples, which describe the features of their preprocessed spectra containing both position information and intensity information, then extract features of the test sample. The authors match these features with the tables and calculate the matching confidence coefficients of the results, which can be used to filter the unexpected matching results caused by accident and attain the final qualitative identification result. The experimental results confirm that this method is effective, efficient and expansible, which means it can be used to identify more actual fiber types by adding more standard spectra to the feature table database. In addition, it is a pure optical method, which needs only a small quantity of sample without any pretreatment. The whole identification process is damage-free, pollution-free and suitable for various kinds of fabrics. Compared to all existing methods, this Raman spectrum identification method can solve the limitation of efficiency, pollution, universality, and fill a gap in fabric inspection field.

Zhu B.,Zhejiang University | Xu F.,Zhejiang University | Li J.,Southwest University | Shuai J.,Zhejiang Entry Exit Inspection and Quarantine Bureau | And 2 more authors.
Virus Research | Year: 2012

Porcine circovirus type 2 (PCV2), an important pathogen of pigs, causes lymphoid depletion in infected tissues most probably by inducing apoptosis although the precise pathogenesis of PCV2-associated diseases remains unknown. We speculate whether autophagy, another cellular response to stress or infections by bacterial or viral pathogens, is involved in PCV2 infection. Here, we provide the first evidence that PCV2 could trigger autophagosome formation and enhance autophagic flux in PK-15 cells, most likely by its capsid protein. Using activators or inhibitors including siRNA targeting atg5, autophagy was found to enhance viral replication and capsid protein expression. These results suggest that PCV2 might employ the autophagy machinery to enhance its replication in host cells, thus raising the possibility of targeting autophagic pathway as a potential antiviral strategy against PCV2 infection. © 2011 Elsevier B.V.

Lv C.,Zhejiang Entry Exit Inspection and Quarantine Bureau | Sun J.,Hangzhou Normal University | Cheng H.,Hangzhou Normal University
Analytical Methods | Year: 2015

In this work, we report a rapid analytical method for the determination of trace formaldehyde in cosmetics on a 12.5 mm C18 guard column. The shortest time (0.5 min) was obtained for one separation with 1.5 mL min-1 of methanol-water 50:50 (v/v) as the mobile phase at a column temperature of 30 °C. A linear response between peak area and the concentration of formaldehyde was obtained over the range 0.1 to 20 mg L-1 with a relative standard deviation of 1.4% (n = 10) at the concentration of 1.0 mg L-1 and a detection limit of 5.1 μg L-1. The confirmation assay by liquid chromatography tandem mass spectrometry indicated that there was no interfering effect from other carbonyl compounds. The proposed method was applied for the determination of formaldehyde residue in cosmetics at the mg L-1 level. Free formaldehyde up to 27 mg kg-1 was found in cosmetics and the spike recovery at the spiked levels of 1.0 and 10.0 mg L-1 varying from 92% to 105% was also obtained. The difference between the values determined by the proposed method and the standard spectrophotometric method was below 3.7%. The results proved the accuracy and precision of the method, showing potential for the routine analysis of formaldehyde residue. © 2015 The Royal Society of Chemistry.

Li S.,Zhejiang University | Yang W.,Zhejiang University | Yang T.,Zhejiang University | Chen Y.,Zhejiang Entry Exit Inspection and Quarantine Bureau | Ni W.,Zhejiang University
International Journal of Phytoremediation | Year: 2015

A hydroponic experiment was conducted to investigate the effects of cadmium (Cd) on chlorophyll fluorescence and photosynthetic parameters on a Cd accumulating plant of Elsholtzia argyi. Four weeks-seedlings of E. argyi were treated with 0 (CK) 5, 10, 15, 20, 25, 30, 40, 50 and 100 μmol L-1 Cd for 21days. Fv/Fo, Fv/Fm, qP, ΦPSP, ETR and Fv′/Fm′ were significantly increased under low Cd (5-15 μmol L-1 for Fv/Fo, Fv/Fm and qP, 5-10 μmol L-1 for ΦPSP, ETR and Fv′/Fm′) stress, and these parameters were similar to control under Cd ≤ 50μmol L-1. All above parameters were significantly decreased at 100 μmol L-1 Cd. Compared with control, Pn was significantly (P < 0.05) increased under 5-30 μmol L-1 Cd. However, 50 and 100 μmol L-1 Cd significantly (P < 0.05) reduced it. Gs and Tr were substantially decreased at 50-100 and 40-100 μmol L-1 Cd, respectively. Ci was significantly increased at 50 and 100 μmol L-1 Cd. High Cd-induced decrease of Pn is not only connected to stomatal limitation but also to the inhibition of Fv/Fo, Fv/Fm, ΦPSP, qP, ETR and increase of NPQ. Maintain chlorophyll fluorescence and photosynthesis parameters under its Cd tolerance threshold were one of tolerance mechanisms in E. argyi. © 2015 Copyright Taylor & Francis Group, LLC.

Huang X.,Chinese Institute of Urban Environment | Liu C.,Chinese Institute of Urban Environment | Li K.,Zhejiang Entry Exit Inspection and Quarantine Bureau | Liu F.,Chinese Institute of Urban Environment | And 4 more authors.
Environmental Science and Pollution Research | Year: 2013

Six antibiotics, tetracyclines (TCs), and quinolones (QNs) in farmland soils from four coastal cities in Fujian Province of China were investigated. Oxytetracycline was most frequently detected, followed by enrofloxacin, ciprofloxacin, chlorotetracycline, ofloxacin, and tetracycline, with maximum concentrations of 613.2, 637.3, 237.3, 2668.9, 205.7, and 189.8 μg kg-1, respectively. Samples from Putian City contained the highest maximum concentration of ∑TCs (3,064.2 μg kg-1), whereas those from Fuzhou City contained the highest maximum concentration of ∑QNs (897.8 μg kg-1). It is noteworthy that the ∑TCs and ∑QNs in 46.4 and 28.6 % of samples exceeded the ecotoxic effect trigger value (100 μg kg-1), respectively. The concentrations of these antibiotics and five tetracycline resistance genes in four soil plots at depth profiles were quantified thereafter. In most cases, both antibiotics and resistance genes decreased with the increase of depth. Some antibiotics can be detected at a depth of 60-80 cm where the abundance of tetO, tetM, and tetX reached up to 107 copies g-1. Additionally, the sum of all tet genes (normalized to 16S rRNA genes) correlated with ∑TCs significantly (r = 0.676). Our results suggest that resistance determinants can migrate to deeper soil layers and would probably contaminate groundwater by vertical transport. © 2013 Springer-Verlag Berlin Heidelberg.

Discover hidden collaborations