Time filter

Source Type

Xie W.,Zhejiang Entry Exit Inspection and Quarantine Bureau | Han C.,Wenzhou Entry Exit Inspection and Quarantine Bureau | Hou J.,Zhejiang Entry Exit Inspection and Quarantine Bureau | Wang F.,Zhejiang Entry Exit Inspection and Quarantine Bureau | And 2 more authors.
Journal of Separation Science | Year: 2012

An LC-MS/MS method developed for simultaneous analysis of 54 veterinary drug residues of six families in pork meat samples, including sulfanilamide, nitroimidazoles, quinolones, macrolide antibiotics, lincosamides, and praziquantel. The pork meat sample was prepared by extraction with ACN, and clean-up on a C18 SPE cartridge. The sample was separated on a C 8 column and eluted with ACN, methanol, and formic acid. The MS/MS detector is operated in the multiple reaction monitoring mode, acquiring two specific precursor-product ion transitions per target compound. The method showed excellent linearity (R2 ≥ 0.99) and high precision (relative SD, RSD ≤ 19.8%) for all compounds. The method quantification limits of 54 veterinary drug residues were in the range of 0.3-3.0 μg/kg. Recoveries for most analytes based on matrix-matched calibration in matrices were 20.9-121.0%. This method has been successfully applied for analysis of more than 100 pork meat samples from the local market; five of the 54 drugs were detected. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Wu S.,CAS Shanghai Institutes for Biological Sciences | Zhang X.,Zhejiang Entry Exit Inspection and Quarantine Bureau | Chen X.,Zhejiang Entry Exit Inspection and Quarantine Bureau | Cao P.,CAS Shanghai Institutes for Biological Sciences | And 2 more authors.
Developmental and Comparative Immunology | Year: 2010

The Toll family of transmembrane proteins mediates signaling during the innate immune response in most animals. Toll9 is widespread in insects and has a unique signature, QHR, in its Toll/interleukin-1 receptor (TIR) domain. The introns in the TIR region are highly conserved among insects, suggesting the antiquity of Toll9 genes. Toll9 of Bombyx mori (BmToll9) was analysed by quantitative real-time RT-PCR. BmToll9 is constitutively expressed in egg, larval and adult stages prior to microbial challenge. BmToll9 is strongly expressed in the different parts of the gut, but weakly expressed in haemocytes, trachea, fat body, malpighian tubule and epidermis, and scarcely expressed in the silk glands. The injection of sterilized 0.85% NaCl solution inhibited BmToll9 expression in most tissues especially during the early responses. Staphylococcus aureus had no or limited effect on the expression of BmToll9 in the silkworm gut and fat body. But in epidermis, trachea, malpighian tubules and haemocytes, the expression of BmToll9 was significantly increased after S. aureus challenge. Infection of Escherichia coli significantly increased the BmToll9 expression in different parts of the gut as well as in epidermis, malpighian tubule and haemocytes. At 48 h after feeding of the fungus, Beauveria bassiana, BmToll9 expression was significantly increased. Tissues responses to the injected and ingested bacteria showed that BmToll9 is probably involved in the local gut immune response in the silkworm. © 2009 Elsevier Ltd.

Wu S.,Zhejiang Entry Exit Inspection and Quarantine Bureau | Wu S.,CAS Shanghai Institutes for Biological Sciences | Zhang X.,Zhejiang Entry Exit Inspection and Quarantine Bureau | He Y.,Zhejiang Entry Exit Inspection and Quarantine Bureau | And 3 more authors.
Developmental and Comparative Immunology | Year: 2010

Although Bombyx mori systematic immunity is extensively studied, little is known about the silkworm's intestine-specific responses to bacterial infection. Antimicrobial peptides (AMPs) gene expression analysis of B. mori intestinal tissue to oral infection with the Gram-positive (Staphylococcus aureus) and -negative (Escherichia coli) bacteria revealed that there is specificity in the interaction between host immune responses and parasite types. Neither Att1 nor Leb could be stimulated by S. aureus and E. coli. However, CecA1, Glo1, Glo2, Glo3, Glo4 and Lys, could only be trigged by S. aureus. On the contrary, E. coli stimulation caused the decrease in the expression of CecA1, Glo3 and Glo4 in some time points. Interestingly, there is regional specificity in the silkworm local gut immunity. During the immune response, the increase in Def, Hem and LLP3 was only detected in the foregut and midgut. For CecB1, CecD, LLP2 and Mor, after orally administered with E. coli, the up-regulation was only limited in the midgut and hindgut. CecE was the only AMP that positively responses to the both bacteria in all the testing situations. With development, the expression levels of the AMPs were also changed dramatically. That is, at spinning and prepupa stages, a large increase in the expression of CecA1, CecB1, CecD, CecE, Glo1, Glo2, Glo3, Glo4, Leb, Def, Hem, Mor and Lys was detected in the gut. Unexpectedly, in addition to the IMD pathway genes, the Toll and JAK/STAT pathway genes in the silkworm gut can also be activated by microbial oral infection. But in the developmental course, corresponding to the increase in expression of AMPs at spinning and prepupa stages, only the Toll pathway genes in the gut exhibit the similar increasing trend. Our results imply that the immune responses in the silkworm gut are synergistically regulated by the Toll, JAK/STAT and IMD pathways. However, as the time for approaching pupation, the Toll pathway may play a role in the AMPs expression. © 2010 Elsevier Ltd.

Xie W.,Zhejiang Entry Exit Inspection and Quarantine Bureau | Han C.,Wenzhou Entry Exit Inspection and Quarantine Bureau | Qian Y.,Zhejiang Lead Product Technic Co | Ding H.,Zhejiang Entry Exit Inspection and Quarantine Bureau | And 2 more authors.
Journal of Chromatography A | Year: 2011

This work reports a new sensitive multi-residue liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for detection, confirmation and quantification of six neonicotinoid pesticides (dinotefuran, thiamethoxam, clothiandin, imidacloprid, acetamiprid and thiacloprid) in agricultural samples (chestnut, shallot, ginger and tea). Activated carbon and HLB solid-phase extraction cartridges were used for cleaning up the extracts. Analysis is performed by LC-MS/MS operated in the multiple reaction monitoring (MRM) mode, acquiring two specific precursor-product ion transitions per target compound. Quantification was carried by the internal standard method with D4-labeled imidacloprid. The method showed excellent linearity (R2≥0.9991) and precision (relative standard deviation, RSD≤8.6%) for all compounds. Limits of quantification (LOQs) were 0.01mgkg-1 for chestnut, shallot, ginger sample and 0.02mgkg-1 for tea sample. The average recoveries, measured at three concentrations levels (0.01mgkg-1, 0.02mgkg-1 and 0.1mgkg-1 for chestnut, shallot, ginger sample, 0.02mgkg-1, 0.04mgkg-1 and 0.2mgkg-1 for tea sample), were in the range 82.1-108.5%. The method was satisfactorily validated for the analysis of 150 agricultural samples (chestnut, shallot, ginger and tea). Imidacloprid and acetamiprid were detected at concentration levels ranging from 0.05 to 3.6mgkg-1. © 2011 Elsevier B.V.

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.

Fu Y.,Shanxi University | An N.,Shanxi University | Li K.,Zhejiang Entry Exit Inspection and Quarantine Bureau | Zheng Y.,Shanxi University | Liang A.,Shanxi University
Journal of Neuro-Oncology | Year: 2012

Development of glioma-specific nanoparticles has been an area of intense research over the past several years. Iron oxide, multifunctional superparamagnetic, and NaYF4:Yb,rare-earth upconversion nanoparticles, conjugated with chlorotoxin (CTX, a key toxin in scorpion venom which has been shown to bind specifically to glioma cell surface as a specific chloride channel and matrix metalloproteinase-2 blocker), exhibit high affinity for glioma and direct tumor visualization. We review the latest improvements of CTX-modified nanoparticle platforms which might enable development of more effective therapeutic agents in clinical treatment of glioma. © Springer Science+Business Media, LLC. 2012.

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.

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.

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.

Loading Zhejiang Entry Exit Inspection and Quarantine Bureau collaborators
Loading Zhejiang Entry Exit Inspection and Quarantine Bureau collaborators