Immunofluorescence Analysis of Duck plague virus gE protein on DPV-infected ducks

<p>Abstract</p> <p>Background</p> <p>In previous studies, the expression and localization characteristics of duck plague virus (DPV) gE protein have been described in cultured cells, but the properties of DPV gE protein have not been reported in vivo. Immunofluorescence analysis had been used for the detection of virus antigen, but there was no report on the use of this technique for the detection of DPV gE. In this study, we investigated the distribution of DPV gE protein on DPV-infected ducks using polyclonal antibody raised against the recombinant His-gE fusion protein by indirect immunofluorescence assay (IFA).</p> <p>Results</p> <p>The recombinant gE protein was highly immunogenicity by ELISA, and the gE was used as an antigen for the preparation of polyclonal antibody, which could be used the first antibody for further experiment to study the distribution of DPV gE protein in DPV-infected tissues by indirect immunofluorescence assay. DPV gE protein were distributed in the immune organs (thymus, bursa of fabricius (BF), Harders glands, spleen), the digestive organs (liver, duodenum, jejunum, ileum), and the other parenchymatous organs (kidney, myocardium, cerebrum, and lung) of DPV-infected ducks, but the positive immunofluorescence signal was not seen in the muscle and pancreas. The lymphocytes, reticulum cells, macrophages, epithelial cells, and hepatocytes served as the principal site for the localization of DPV gE antigen. Moreover, the intensity of fluorescence increased sharply from 12 to 216 h post-infection (p.i.).</p> <p>Conclusions</p> <p>In this work, the immunogenicity of the recombinant gE protein was analyzed by ELISA, and we presented the distribution properties of DPV gE antigen in infected ducks for the first time, which may be useful for understanding the pathogenesis of DPV. These properties of the gE protein provided the prerequisite for further functional analysis.</p

Studies of dopamine oxidation process by atmospheric pressure glow discharge mass spectrometry

An atmospheric pressure glow discharge ionisation source was constructed and utilized to study the dopamine (DA) oxidation process coupling with mass spectrometry. During the DA oxidation process catalysed by polyphenol oxidase (PPO), six cationic intermediates were directly detected by the atmospheric pressure glow discharge mass spectrometry (APGD-MS). Combined with tandem mass spectrometry, the structures of the dopamine o-semiquinone radical (DASQ) and leukodopaminochrome radical (LDAC●) intermediates and structures of the isomers of dopaminochrome (DAC) and 5,6-dihydroxyindole (DHI) were further characterised with the introduction of 2,2,6,6-tetramethylpiperidine 1-oxyl (TEMPO) and deuterium oxide (D2O) to APGD-MS. Meanwhile, UV–Vis studies confirmed the important role of PPO in catalyzing the DA oxidation reaction. Based on APGD-MS studies, a possible mechanism could be proposed for DA oxidation catalysed by PPO. Furthermore, APGD-MS could provide possibilities for the effective detection and characterisation of short-lived intermediates, even in complicated systems

RESEARCH ON MULTI-BODY DYNAMIC SIMULATION OF HUMANOID FOOT TYPE STAIR CLIMBING WHEELCHAIR BASED ON ADAMS

Based on the design of the new type of humanoid foot shaped wheelchair and the usage of large-scale engineering software named ADMAS,to simplify the wheelchair model to establish a multi-body dynamics system,and analyzed a virtual prototype simulation. In order to apply the rotation pairs of the front and back wheels of the wheelchair of the ADAMS and IF function and AZ function,many simulation experiments are carried out to simulate the parameters of the driving motor and the mechanical parameters of the mechanical legs. The mechanical characteristics of the key parts of the robot are compared. The kinematics curves and the mechanical curves are analyzed. And the stability of the climbing process is analyzed. It provides an important basis for reasonable selection of the model and the length of the machine,and provided a theoretical basis for the optimization design of other mechanisms

R/S analysis of gas emission in coal mine underground tunnel

In order to grasp changes of the danger of coal and gas outburst, factors of coal seam gas emission were analyzed, R/S analysis method was used to study gas emission of coal mine tunnel, and the following conclusion was obtained: gas emission time series have fractal characteristics, when it is detected that Hurst index is decreasing and has great volatility, it indicates abnormal gas emission will occur, so certain safety precautions should be taken in advance

Cadmium isotope fractionation during adsorption onto calcite

Adsorption on mineral surfaces is a crucial process controlling (bio)geochemical cycling of Cd, and Cd isotopic behaviour during adsorption is an important but little investigated aspect of Cd isotope systematics. This work looked at the fractionation of Cd isotopes during Cd adsorption onto calcite, which is an important sink of Cd but isotopic behaviour has only previously been investigated in co-precipitation experiments. The Cd isotope composition of calcite adsorbed components was determined to be lighter and consistent with equilibrium fractionation in all experiments. And degree of fractionation observed in our experiments is not influenced by the Cd/CaCO3 ratio, pH value or Cd/PO43− ratio in the studied range. In MQ water, the observed fractionation value αsorbed-aqueous is 0.99934 but this α value is affected by the presence of other compounds. Notably, αsorbed-aqueous = 0.99984, a reduced but resolvably lower value fractionation, was observed in the presence of PO43− which may be an important factor to be considered when interpreting Cd isotope signatures in nature. The enrichment of lighter Cd isotopes may result from highly distorted octahedral Cdsingle bondO6 sites of inner-sphere Cd complexes on calcite, indicated by extended X-ray absorption fine structure (EXAFS). However, near identical coordination environments of the aqueous and sorbed Cd species in the presence of PO43− likely led to the reduced Cd isotope fractionation. This work suggests adsorption of Cd onto carbonates minerals may produce significant Cd isotope fractionation between fluids and solid phase. Our observations offer an alternative process apart from co-precipitation when interpreting Cd isotope ratios in the presence of calcite in paleo-geological studies and could be helpful to better understand Cd (bio)geochemical cycling

Molecular photoswitches for super-resolution optical imaging

We report a series of fluorescence molecular switches including spiropyrans (SPs), dithienylethenes (DTEs) and hexaarylbiimidazoles (HABIs) and investigate their optical properties such as photochromism and photoswitchable aggregation-induced emission (condensed-state). © OSA 2013.Link_to_subscribed_fulltex