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| Articles
by
Lijuan Zhang |
Total Records (
3 ) for
Lijuan Zhang |
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Zhenhua Gong
,
Lijuan Zhang
,
Ping Lu
,
Yonghao Hu
,
Liping Wang
and
Weihua Li
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Marek’s Disease (MD) is one of the main infectious diseases
that threaten the healthy development of the Chinese poultry industry. The evolution
of epidemic strains of the MD Virus (MDV) in China is different from the evolution
of strains overseas. The meq gene sequence of pathogenic strains is different
from that of the attenuated vaccine strain (MDV-1). The meq and L-meq
gene sequences of the MDV in the lymphoid tissue of chickens in latency period
are homologous. The meq gene was only found in the lymphoid tissue of
chickens during the onset period. |
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Chyong Fang Hsu
,
Lijuan Zhang
,
Hui Peng
,
Jadranka Travas-Sejdic
and
Paul A. Kilmartin
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Polypyrrole (PPy) powders were synthesized chemically using the oxidant ammonium persulfate (APS). The free radical scavenging properties were evaluated using a form of the α,α-diphenyl-β-picrylhydrazyl (DPPH) assay adapted for use with 1.0 mg amounts of conducting polymer powders. A lower scavenging capacity was obtained when a higher ratio of APS to pyrrole was used in the chemical synthesis which also led to a decrease in polymer conductivity and doping level as determined by the amount of (bi)sulfate present given by elemental analyses. The occurrence of overoxidation of polypyrrole at a higher oxidant level was confirmed in FTIR spectra by the presence of a carbonyl group. PPy prepared at a lower APS/pyrrole ratio contained more bipolaron charge carriers, which were converted to polarons upon initial reduction with hydrazine. More complete reduction with hydrazine led to a loss of (bi)sulfate dopant, but to improved DPPH radical scavenging, confirming that the conducting polymer is acting as a reducing agent in scavenging DPPH radicals. |
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Ariane I. de Agostini
,
Ji-Cui Dong
,
Corinne de Vantery Arrighi
,
Marie-Andree Ramus
,
Isabelle Dentand-Quadri
,
Sebastien Thalmann
,
Patricia Ventura
,
Victoria Ibecheole
,
Felicia Monge
,
Anne-Marie Fischer
,
Sassan HajMohammadi
,
Nicholas W. Shworak
,
Lijuan Zhang
,
Zhenqing Zhang
and
Robert J. Linhardt
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Anticoagulant heparan sulfate proteoglycans bind and activate antithrombin by virtue of a specific 3-O-sulfated pentasaccharide. They not only occur in the vascular wall but also in extravascular tissues, such as the ovary, where their functions remain unknown. The rupture of the ovarian follicle at ovulation is one of the most striking examples of tissue remodeling in adult mammals. It involves tightly controlled inflammation, proteolysis, and fibrin deposition. We hypothesized that ovarian heparan sulfates may modulate these processes through interactions with effector proteins. Our previous work has shown that anticoagulant heparan sulfates are synthesized by rodent ovarian granulosa cells, and we now have set out to characterize heparan sulfates from human follicular fluid. Here we report the first anticoagulant heparan sulfate purified from a natural human extravascular source. Heparan sulfate chains were fractionated according to their affinity for antithrombin, and their structure was analyzed by 1H NMR and MS/MS. We find that human follicular fluid is a rich source of anticoagulant heparan sulfate, comprising 50.4% of total heparan sulfate. These antithrombin-binding chains contain more than 6% 3-O-sulfated glucosamine residues, convey an anticoagulant activity of 2.5 IU/ml to human follicular fluid, and have an anti-Factor Xa specific activity of 167 IU/mg. The heparan sulfate chains that do not bind antithrombin surprisingly exhibit an extremely high content in 3-O-sulfated glucosamine residues, which suggest that they may exhibit biological activities through interactions with other proteins. |
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