[Progress in research of 2019-nCoV infection in children and adolescents].

As 2019-nCoV vaccine is widely used in the adult population, children and adolescents have gradually become an important susceptible population to 2019-nCoV due to their low coverage of the vaccine and high contact degree. Understanding the characteristics of 2019-nCoV infection in minors is vital. This paper summarized the progress in the research of 2019-nCoV in minors by using the data from the retrieval of recently published literature. Furthermore, the key characteristics of 2019-nCoV infection in minors, including the susceptibility, transmissibility, prognosis and immune response were analyzed and the progress in child and adolescent vaccine development was introduced.

[The study of binding of the virG gene product with the virD gene promotor region of the Agrobacterium tumefaciens Ti-plasmid C58]. / Izuchenie sviazyvaniia produkta gena virG s promotornoi oblast'iu gena virD Ti-plazmidy Agrobacterium tumefaciens C58.

The 1.5 kb EcoRI--HindIII fragment of the pTiC58 containing the virD regulatory sequence demonstrates a constitutive promoter activity in E. coli background and an inducible one in agrobacterium. The virG gene was cloned in pTZ19R plasmid. To reveal the virG product--virD regulatory sequence interaction a few protein fractions of E. coli harbouring the obtained recombinant plasmid pTZ19G lysate were used. PAGE-retardation assay revealed the specific binding between the 1.5 kb DNA fragment containing 5'-end of virD and a separate protein fraction of the bacterial lysate.

Intracellular oxidative stress and cadmium ions release induce cytotoxicity of unmodified cadmium sulfide quantum dots.

OBJECTIVE: To fully understand the cytotoxicity of after-degradation QDs, we synthesized CdS QDs and investigated its toxicity mechanism. METHODS: Biomimetic method was proposed to synthesize cadmium sulfide (CdS) QDs. Thereafter MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide) assay was conducted to evaluate their cytotoxicity. To investigate the toxicity mechanism, we subsequently conducted intracellular reactive oxygen species (ROS) measurement with DCFH-DA, glutathione (GSH) measurement with DTNB, and cellular cadmium assay using atomic absorption spectrometer. Microsized CdS were simultaneously tested as a comparison. RESULTS: MTT assay results indicated that CdS QDs are more toxic than microsized CdS especially at concentrations below 40 microg/ml. While microsized CdS did not trigger ROS elevation, CdS QDs increase ROS by 20-30% over control levels. However, they both deplete cellular GSH significantly at the medium concentration of 20 microg/ml. In the presence of NAC, cells are partially protected from CdS QDs, but not from microsized particles. Additionally, nearly 20% of cadmium was released from CdS nanoparticles within 24h, which also accounts for QDs' toxicity. CONCLUSION: Intracellular ROS production, GSH depletion, and cadmium ions (Cd(2+)) release are possible mechanisms for CdS QDs' cytotoxicity. We also suggested that with QD concentration increasing, the principal toxicity mechanism changes from intracellular oxidative stress to Cd(2+) release.