instruction:
In this task, you're given a paragraph from the research paper and your task is to generate a suitable title for the research paper based on the given paper. Under 100 words is a good title length.
question:
Madin Darby canine kidney (MDCK) cells were adapted to serum-free RPMI 1640 medium and used for cultivation of canine viruses. RPMI 1640 medium was supplemented with a soybean peptone, l-glutamine and antibiotics, so that the protein concentration was less than 5 g/ml (RPMI/SP medium). The resulting adapted MDCK-SP cells showed steady growth after the twenty-eighth passage in RPMI/SP medium (MDCK-SP cell culture). Canine distemper virus, canine parvovirus, canine adenoviruses and canine parainfluenza virus, which are the principal components of canine combined virus vaccines, grew in the MDCK-SP cell culture as efficiently as the parental MDCK cells cultured in the conventional Eagle's MEM containing fetal bovine serum. Consequently, the use of MDCK-SP cell culture can make current canine vaccine products much safer, of higher quality and at lower cost.
answer:
Growth characteristics of canine pathogenic viruses in MDCK cells cultured in RPMI 1640 medium without animal protein


question:
Many new RNA pseudoknot structures have been detected and proposed in the past year. Although we are still waiting for the first detailed structure of a pseudoknot, their role in processes such as translational autoregulation or ribosomal frameshifting has been extensively studied and is now well established. Pseudoknot structures appear to play a pivotal role in small subunit ribosomal RNA and in the noncoding regions of viral RNAs. There are also strong indications that RNA pseudoknots are highly suitable structural motifs for the recognition and binding of proteins.
answer:
RNA pseudoknots


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Wuhan. Specific antiviral drug are urgently needed to treat COVID-19 infections. The main protease (M pro ) of SARS-CoV-2 is a key CoV enzyme that plays a pivotal role in mediating viral replication and transcription, which makes it an attractive drug target. In an effort to rapidly discover lead compounds targeting M pro , two compounds (11a and 11b) were designed and synthesized, both of which exhibited excellent inhibitory activity with an IC 50 value of 0.05 μ M and 0.04 μ M respectively. Significantly, both compounds exhibited potent anti-SARS-CoV-2 infection activity in a cell-based assay with an EC 50 value of 0.42 μ M and 0.33 μ M, respectively. The X-ray crystal structures of SARS-CoV-2 M pro in complex with 11a and 11b were determined at 1.5 Å resolution, respectively. The crystal structures showed that 11a and 11b are covalent inhibitors, the aldehyde groups of which are bound covalently to Cys145 of M pro . Both compounds showed good PK properties in vivo, and 11a also exhibited low toxicity which is promising drug leads with clinical potential that merits further studies.
answer:

Structure-Based Design, Synthesis and Biological Evaluation of Peptidomimetic Aldehydes as a Novel Series of Antiviral Drug Candidates Targeting the SARS-CoV-2 Main Protease