One-Step Platform for Maduramicin and Salinomycin Detection Based on Bispecific Monoclonal Antibody and Interpretation of Molecular Recognition Mechanism.

Maduramicin (MAD) and salinomycin (SAL) are the widely used poly(ether ionophore) antibiotics to control coccidiosis in animals. Due to their strong cytotoxicity, strict control over their dosage and residue in animal food is necessary. To improve the detection efficiency of the existing single-residue detection methods, a tetraploid tumor hybrid system was constructed using drug mutagenesis, and the bispecific monoclonal antibody (BsMAb) against MAD and SAL was obtained by hybridization-hybridoma technology. By optimizing the optimal working concentration of the tracer and antibody, a multiresidue fluorescence polarization immunoassay method based on BsMAb was successfully established. The whole detection process takes 10 min, and the LOD values of MAD and SAL were 4.71 and 3.49 ng·g-1, respectively. IC50 values were 6.45 and 6.24 ng·mL-1, respectively. There was no cross-reactivity with other polyether ionophore antibiotics. Finally, a breakthrough in detection was achieved: bispecific monoclonal antibody prepared by the hybridization-hybridoma technology was used to detect maduramicin and salinomycin.

Impact of China's National Centralized Drug Procurement Policy on pharmaceutical enterprises' financial performance: a quasi-natural experimental study.

Introduction: In China, the interest relationship between pharmaceutical enterprises and medical institutions has harmed the healthy development of pharmaceutical enterprises. In November 2018, the National Centralized Drug Procurement (NCDP) policy was published. The NCDP policy severs the interest relationship and significantly impacts on pharmaceutical enterprises's financial performance. Methods: Using the implementation of China's National Centralized Drug Procurement (NCDP) policy as a quasi-natural experiment, this study evaluated the impact of participation in the NCDP policy on pharmaceutical enterprises' financial performance. We developed a difference-in-difference model to estimate the change in financial performance after NCDP implementation, based on financial data on Chinese listed pharmaceutical enterprises. Results: We found that the bid-winning enterprises' financial performance significantly improved after participating in NCDP. This may be related to lower costs, market share expansion, and increased research and development investment by the bid-winning enterprises. Discussion: To further promote the high-quality development of pharmaceutical enterprises in China, the government should expand the variety of drugs on the NCDP list (NCDP drugs), while improving the drug patent protection system and the policies to support the bid-winning enterprises.

The SHH-GLI1 pathway is required in skin expansion and angiogenesis.

To investigate the role of GLI1 on skin proliferation and neovascularization during skin expansion in mice. We constructed GLI1-cre/R26-Tdtomato and GLI1-cre/R26-mtmg gene-tagged skin expansion mouse models. Using a two-photon in vivo imaging instrument to observe the changes in the number and distribution of GLI1(+) cells during the expansion process and to clarify the spatial relationship between GLI1(+) cells and blood vessels during the expansion process. In vitro proliferation assays were performed to further validate the effects of SHH (sonic hedgehog) and its downstream component GLI1 on cell proliferation viability. Finally, qRT-PCR was used to verify the changes in proliferation, angiogenesis-related factors, SHH signalling pathway-related factors, and the role of GLI1 cells in the process of skin expansion in mice. The number of GLI1(+) cells increased during dilation and were attached to the outer membrane of the vessel. The epidermis was thickened and the dermis thinned after the dilated skin was taken, while the epidermal thickening was suppressed and the dermis became thinner after the GLI1 cells were inhibited. The non-inhibited group showed a significant increase in PCNA positivity with prolonged dilation compared to the GANT61(GLI specificity inhibitor) inhibited group; CD31 immunofluorescence showed a significant increase in the number of dilated skin vessels and a significant decrease in the number of vessels after treatment with GANT61 inhibitor. In vitro proliferation results showed that SHH signalling activator significantly increased the proliferation viability of GLI1(+) hair follicle mesenchymal stem cells, while GNAT61 significantly inhibited the proliferation viability of GLI1(+) hair follicle mesenchymal stem cells. GLI1 is necessary for proliferation and neovascularization in expansion skin of mice through activation of the SHH signalling pathway.

Development of a detection method for 10 non-steroidal anti-inflammatory drugs residues in four swine tissues by ultra-performance liquid chromatography with tandem mass spectrometry.

The ultra-performance liquid chromatography with tandem mass spectrometry (UPLC-MS/MS) detection method was developed for the residues of 10 NSAIDs (salicylic acid, acetylsalicylic acid, acetaminophen, diclofenac, tolfenamic acid, antipyrine, flunixin meglumine, aminophenazone, meloxicam, metamizole sodium) in swine muscle, liver, kidney, and fat. Swine tissue samples were extracted by phosphorylated acetonitrile with the addition of an appropriate amount of internal standard working solution, defatted with acetonitrile-saturated n-hexane, and purified by Hydrophile-Lipophile Balance (HLB) solid-phase extraction column, then separated by UPLC BEH shield RP18 column with 0.1% formic acid in water/0.1% formic acid in acetonitrile with gradient elution, which was detected in the multiple reaction monitoring (MRM) modes. The correlation coefficient of the standard curve equation is greater than 0.99, and the coefficient of variation within and between batches is less than 14.4%. We evaluated the analytical method using two green assessment tools. The method established in this study met the requirements of NSAID residue analysis and provides analytical tools for determining and confirming NSAIDs in swine tissue samples. This is the first report on the simultaneous determination of 10 NSAIDs in four swine tissues by the UPLC-MS/MS method and accurate quantification using deuterated internal standards.

Monodisperse Cu/Cu2O@C core-shell nanocomposite supported on rGO layers as an efficient catalyst derived from a Cu-based MOF/GO structure.

A novel copper/copper(i) oxide@carbon (Cu/Cu2O@C) core-shell nanocomposite monodispersed on the surface of reduced graphene oxide (defined as Cu/Cu2O@C-rGO) was synthesized using a one-step calcination of Cu-based metal organic frameworks (MOFs)/graphene oxide (GO) composite structure. The size of the resultant Cu/Cu2O@C core-shell nanoparticles (NPs) on the rGO layers were mainly distributed in range of about 90-100 nm with good dispersion, which was characterized using transmission electron microscopy. X-ray diffraction, Raman spectroscopy, Fourier transform infrared spectroscopy, nitrogen adsorption-desorption isotherms, X-ray photoelectron spectrometry and thermogravimetric analyses were also carried out to characterize the structure and composition of the Cu/Cu2O@C-rGO. The catalytic performance of the Cu/Cu2O@C-rGO composite was evaluated using a reduction reaction from 4-nitrophenol to 4-aminophenol. It was demonstrated that the Cu/Cu2O@C-rGO composite exhibited an excellent catalytic performance, which can reach a nearly 100% conversion rate in 90 s with 0.1 mg of catalyst. This catalyst also showed a good performance for the degradation of other organic dyes such as methylene blue, methyl orange and rhodamine B. Additionally, the core-shell structure exhibited good stability and reusability for the reduction reaction, which was because of its relatively better oxidation resistance than that of the bare Cu NPs. This research provided an efficient and stable non-noble metal-based catalyst derived from the MOF/GO structure.

[Preparation of weak light driven TiO2 multi composite photocatalysts via adsorption phase synthesis].

Photodegradation of pollutions by TiO2 under irradiation of weak UV and visible lights was one of the key points to expand the application of heterogeneous photocatalysis. Based on the adsorption phase synthesis, N doping and co-doping with N and Fe2O3 were employed to prepare TiO2 multi composite photocatalysts. The activity of these photocatalyts was evaluated by photodegradation of methyl-orange illuminated under weak UV and visible lights. Via UV-Vis diffuse reflectance spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy and photoluminescence spectra, the effects on the light absorption and visible response expansion of catalysts caused by different conditions were explored, such as sintering temperature, doping content of N and co-doping. Followed that, the changes in the photocatalytic activities were studied under the irradiation of weak light. The results showed that, N doping could enhance the light absorption of the catalysts, thus significantly enhanced their photocatalytic activity illuminated under UV weak light. All N-doped photocatalysts had a higher activity than the commercial available P25 photocatalyst. The visible response of catalysts was expanded little caused by N doping, thereby most catalysts doped by single N element had no activity illuminated by weak visible light. Only the catalyst doped with 5% of N element showed a weak activity after calcined at 900 degrees C . Due to the synergy effects between N doping and Fe2O3 coupling, co-doping did not only enhance the light absorption of the catalysts, but also significantly expanded the visible response of catalysts. So, co-doped catalysts showed a good catalytic activity when excited by weak visible light.