Biomedical subjects

Zhaoyang Wu

Publications and source records attributed to Zhaoyang Wu.

8 recordsLinked to original sources

PubMed2026

Stable chloroform emissions in southeastern China: insights from recent observations.

Chloroform (CHCl3) is a short-lived ozone-depleting substance not currently regulated under the Montreal Protocol. Due to the unique meteorological conditions in East Asia, CHCl3 emitted in this region has a greater potential to reach the stratosphere and contribute to ozone depletion. As an essential component of national CHCl3 emissions, southeastern China has attracted increasing attention. However, long-term observational data in this region remain relatively scarce, with no updates since 2020. In this study, we continuously measured atmospheric CHCl3 concentrations at a remote monitoring station in southeastern China from 1 June 2023 to 31 May 2025. Frequent concentration enhancements were observed during the monitoring period, with mixing ratios ranging from 9.3 to 134.1 ppt and an average value of 36.8 ± 19.7 ppt. Back-trajectory analysis indicated that air masses associated with elevated CHCl3 levels primarily originated from coastal industrial provinces in eastern China. Using the Potential Source Contribution Function and Concentration Weighted Trajectory methods, we identified the Yangtze River Delta (Jiangsu, Anhui, and Zhejiang Provinces) and Jiangxi Province as dominant source regions. Emissions of CHCl3 in southeastern China were estimated using the Tracer Ratio Method to be approximately 30.1 ± 5.3 Gg/yr from 2023-06-01 to 2025-05-31, indicating overall stability relative to earlier estimates and no apparent upward trend. These findings provide updated insights into the current status of CHCl3 emissions in southeastern China and highlight the need for continued monitoring and emission assessment of CHCl3 in East Asia, given its unregulated status and implications for ozone layer recovery.

Air Pollutants↗

PubMed2006

An amplified mass piezoelectric immunosensor for Schistosoma japonicum.

An ultrasensitive piezoelectric immunosensor using an amplification path based on an insoluble biocatalyzed precipitation product has proposed for Schistosoma japonicum. A mercapto Schistosoma japonicum antigen was self-assembled onto the quartz crystal surface via an Au nanoparticle mediator monolayer to sense the Schistosoma japonicum antibody (SjAb). And the horseradish peroxidase labeled protein A conjugate which was bounded to the SjAb by a "sandwich" format was used as a biocatalyst for the oxidative precipitation of 4-chloro-1-naphthol by H(2)O(2) to yield the insoluble product benzo-4-chlorohexadienone, resulting in an amplified mass sensing of antigen-antibody interaction. The amount of the precipitate accumulated on the quartz crystal is controlled by the antibody concentration. The SjAb can be linearly determined in the range of 10-200 ngml(-1) and the detection limit reaches as low as 5 ngml(-1).

Animals↗

PubMed2006

[Effect of pilose antler polypeptides on the apoptosis of rabbit marrow mesenchymal stem cells differentiated into chondrogenic phenotype in vitro].

OBJECTIVE: To observe the effect of pilose antler polypeptides (PAP) on the apoptosis of rabbit marrow mesenchymal stem cells (MSCs) differentiated into chondrogenic phenotype by interleukin 1beta (IL-1beta) so as to optimize the seeding cells in cartilage tissue engineering. METHODS: The MSCs were separated from the nucleated cells fraction of autologous bone marrow by density gradient centrifuge and cultured in vitro. The MSCs were induced into chondrogenic phenotype by transforming growth factor beta1 (TGF-beta1) and basic fibroblast growth factor (bFGF). According to different medias, the MSCs were randomly divided into four groups: group A as black control group, group B (100 ng IL-1beta), group C (10 microg/ml PAP + 100 ng IL-1beta) and group D (100 ng/ml TGF-beta1 + 100 ng IL-1beta). The samples were harvested and observed by morphology, flow cytometry analysis, RT-PCR and ELISA at 24, 48 and 72 hours. RESULTS: The intranuclear chromatin agglutinated into lump and located under nuclear membranes which changed into irregular shape at 24 hours. The intranuclear chromatin agglutinated intensified at 48 hours. Then the nuclear fragments agglutinated into apoptosis corpuscles at 72 hours in group B. The structure change of cells in groups C and D was later than that in group B, and the number of cells changed shape was fewer than that in group B. The structure change of cells in group A was not significant. The apoptosis rate of cells, the mRNA expression of Caspase-3 and the enzymatic activity of Caspase-3 gradually increased in group B, and there were significant differences compared with groups A, C and D (P < 0.01). CONCLUSION: Caspase-3 is involved in apoptosis of the MSCs differentiated into chondrogenic phenotype cultured in vitro. PAP could prevent from or reverse apoptosis of these MSCs by decreasing the expression of Caspase-3 and inhibiting the activity of Caspase-3.

Animals↗

PubMed2004

A plasma-polymerized film for capacitance immunosensing.

A capacitance immunosensor based on a plasma-polymerized ethylenediamine film (PPEF) has been developed. The resulting PPEF is studied with scanning electrode micrograph (SEM), IR reflection spectrum and cyclic voltammetry. SEM and IR reflection spectrum showed that the plasma-polymerized film (PPF) formed on the gold electrode surface is quite homogeneous, flat, nonporous and contains plenty of free-reacted -NH2. Moreover, cyclic voltammetry showed that the hexacyanoferrate redox reactions were blocked well by the formed PPF, that is to say, the formed PPF has excellent insulating characteristics. To investigate its applicability for capacitive immunosensing, goat-anti-human IgG antibody (IgGAb) was coupled to the PPF-coated gold electrode surface via glutaraldehyde (GA) to form an immunoglobulin G (IgG) probe. Alternating current (ac) impedance and capacitance measurement were used in the immunoassay. The experiment results show that the PPEF is applicable to form insulating layer of capacitive immunosensors.

Biosensing Techniques↗

PubMed2004

A piezoelectric immunoagglutination assay for Toxoplasma gondii antibodies using gold nanoparticles.

The serologic detection of anti-Toxoplasma gondii immunoglobulins plays a key role in the clinical diagnosis of Toxoplasmosis. In this paper, a simple, rapid and highly sensitive agglutination-based piezoelectric immunoassay has been firstly developed for directly detecting anti-T. gondii immunoglobulins in infected rabbit serum (IRS) and infected rabbit blood (IRB). The proposed technique is based on that the specific agglutination of antigen-coated gold nanoparticles, averaging 10nm in diameter, in the presence of the corresponding antibody causes a frequency change that is monitored by a piezoelectric device. In contrast to the commonly used piezoelectric assays, it possesses an attractive advantage in that the immobilization of antibody or antigen on the crystal is unnecessary. Use of a newly prepared sensing probe which was modified by a plasma-polymerized film (PPF) of n-butyl amine and further by a heparin layer resulted in a response-enhanced immunoagglutination and a high compatibility of the probe with biological samples. An appropriate reagent consisting of 1% normal rabbit serum (NRS) and 0.1% bovine serum albumin (BSA) for diluting the analytes were verified in counteracting the background interference of assay. Moreover, an optimization of assay medium composition with the addition of poly(ethylene glycol) (PEG) serving as immunoagglutination rate and sensitivity enhancer was investigated in detail. It is found that the developed immunoagglutination assay system is sensitive to dilution ratio of anti-T. gondii antibody as low as 1:5500. Analytical results of several specimens obtained using the developed technique are in satisfactory agreement with those given by the ELISA method, implying a promising alternative approach for detecting anti-T. gondii antibodies in the clinical diagnosis.

Agglutination Tests↗

PubMed2003

A novel biosensing interfacial design produced by assembling nano-Au particles on amine-terminated plasma-polymerized films.

A novel biosensing interfacial design strategy has, for the first time, been produced by assembling nano-Au particles on amine-terminated plasma-polymerized films (PPF). A quartz-crystal microbalance (QCM) as a model transducer was deposited with PPF of n-butylamine by use of a glow discharge and then treated with nano-Au particles. The kinetic assembly process and conditions were studied using the real-time-output device and the surface topology of the resulting crystal was characterized by atomic force microscopy (AFM) imaging. Based on analysis of the experimental data, including the association constant of Au-amine interaction, the assembly mechanism is considered to be partly or even mainly chemical adsorption. Moreover, immobilization of anti-human IgM antibody (IgM Ab), as an example, on the developed PPF-Au interface was investigated. It was found that antibody molecules immobilized by the proposed procedure had higher immunological activity than those immobilized by the conventional glutaraldehyde (GLU) cross-linking procedure or the direct gold-attachment procedure. The newly developed sensor had a better response, with a detection limit of IgM concentration as low as approximately 1.00 microg mL(-1). In particular, the extremely high stability of both PPF and nano-Au monolayer formulated allows the designed biosensing interface to withstand harsh regeneration treatment, making it reusable.

Biosensing Techniques↗

PubMed2002

A piezoelectric immunoassay based on self-assembled monolayers of cystamine and polystyrene sulfonate for determination of Schistosoma japonicum antibodies.

A piezoelectric immunosensor based on an improved immobilization strategy combining self-assembled monolayers (SAM) of cystamine (Cys) and polystyrene sulfonate (PSS) has been developed for the determination of Schistosoma japonicum antibodies (SjAb) in rabbit serum. Cys SAM were first applied to the gold electrode surface of the crystal, serving as a positively-charged base. Schistosoma japonicum antigen (SjAg) was then electrostatically immobilized on the crystal by means of a negatively-charged PSS layer. When sealed by use of an appropriately selected blocking reagent for BSA and normal rabbit serum (NRS), non-specific adsorption could be substantially reduced. The immunosensor was used to determine SjAb in optimized buffer medium with addition of poly(ethylene glycol) (PEG), which served as an immunoreaction enhancer. It was shown experimentally that SjAg immobilized by the Cys-PSS adsorption procedure had higher immunological activity or binding efficiency than those immobilized by the glutaraldehyde (GLU) binding or direct attachment procedures. The immunosensor developed had satisfactory sensitivity and detection limit, and regeneration of the piezoelectric quartz-crystal was easy. Analytical results obtained with infected rabbit serum samples indicated that the proposed immunosensor is a promising alternative for qualitative and quantitative determination of SjAb in clinical diagnosis of infection with Schistosoma japonicum.

Adsorption↗

PubMed2002

Renewable urea sensor based on a self-assembled polyelectrolyte layer.

A renewable urea sensor based on a carboxylic poly(vinyl chloride) (PVC-COOH) matrix pH-sensitive membrane has been proposed, in which a positively charged polyelectrolyte layer is first constructed by using a self-assembly technique on the surface of a PVC-COOH membrane, and urease, with negative charges, is then immobilized through electrostatic adsorption onto the PVC-COOH membrane, by controlling the pH of the urease solution below its isoelectric point. The response characteristics of the PVC-COOH pH-sensitive membrane and the effects of experimental conditions have been investigated in detail. Compared with conventional covalent immobilization, the urea sensor made with this self-assembly immobilization shows significant advantage in terms of sensitivity and ease of regeneration. The potential responses of the urea sensor with self-assembly immobilization increase with the urea concentration over the concentration range 10(-5) - 10(-1) mol l(-1), and the detection limit is 0.028 mmol(-1). Moreover, this type of urea sensor can be repeatedly regenerated by using a simple washing treatment with 0.01 mol l(-1) NaOH (containing 0.5 mol l(-1) NaCl) and 0.01 mol l(-1) HCl. The urease layers and the polyelectrolyte layers on the PVC-COOH membrane are removed, the potential response of the sensor to urea solutions of different concentrations returns nearly to zero, and another assembly cycle of urease and polyelectrolyte can then be carried out.

Biosensing Techniques↗