In this task, you're given a paragraph and title from the research paper. Your task is to classify whether the given title is suitable or not for the research paper based on the given paragraph. Return "True" if title is proper according to paragraph else "False".

[Q]: Paragraph: The envelope spike (S) proteins of MERS-CoV and SARS-CoV determine the virus host tropism and entry into host cells, and constitute a promising target for the development of prophylactics and therapeutics. Here, we present high-resolution structures of the trimeric MERS-CoV and SARS-CoV S proteins in its pre-fusion conformation by single particle cryo-electron microscopy. The overall structures resemble that from other coronaviruses including HKU1, MHV and NL63 reported recently, with the exception of the receptor binding domain (RBD). We captured two states of the RBD with receptor binding region either buried (lying state) or exposed (standing state), demonstrating an inherently flexible RBD readily recognized by the receptor. Further sequence conservation analysis of six human-infecting coronaviruses revealed that the fusion peptide, HR1 region and the central helix are potential targets for eliciting broadly neutralizing antibodies. 
 Title: ARTICLE Cryo-EM structures of MERS-CoV and SARS-CoV spike glycoproteins reveal the dynamic receptor binding domains
[A]: False


[Q]: Paragraph: Previously developed Asn-Gly-Arg (NGR) peptide-modified multifunctional poly(ethyleneimine)-poly(ethylene glycol) (PEI-PEG)-based nanoparticles (TPIC) have been considered to be promising carriers for the co-delivery of DNA and doxorubicin (DOX). As a continued effort, the aim of the present study was to further evaluate the interaction between TPIC and human umbilical vein endothelial cells (HUVEC) to better understand the cellular entry mechanism. In the present investigation, experiments relevant to co-localization, endocytosis inhibitors and factors influencing the internalization were performed. Without any treatment, there was no co-localization between aminopeptidase N/CD13 (APN/CD13) and caveolin 1 (CAV1). However, co-localization between CD13 and CAV1 was observed when cells were incubated with an anti-CD13 antibody or TPIC. As compared with antibody treatment, TPIC accelerated the speed and enhanced the degree of co-localization. TPIC entered HUVEC not only together with CD13 but also together with CAV1. However, this internalization was not dependent on the enzyme activity of CD13 but could be inhibited by methyl-β-eyclodextfin (MβCD), further identifying the involvement of caveolae-mediated endocytosis (CvME). This conclusion was also verified by endocytosis inhibitor experiments. 
 Title: A preliminary study on the interaction between Asn-Gly-Arg (NGR)-modified multifunctional nanoparticles and vascular epithelial cells-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)
[A]: False


[Q]: Paragraph: It is believed that the genomic 5 untranslated region (UTR) of Arterivirus plays crucial roles in viral genomic replication, subgenomic mRNA transcription and protein translation, yet the structure and function still remain largely unknown. In this study, we conducted serial nucleotide truncation, ranging from 1 to 190 nucleotides, to the 5 UTR of the porcine reproductive and respiratory syndrome virus (PRRSV) infectious full-length cDNA clone pAPRRS. In vitro synthetic RNAs were transfected into MARC-145 cells for further genetic and virologic analysis. Our results demonstrated that the first three nucleotides of PRRSV 5 UTR were dispensable for virus viability, which however was repaired with foreign sequences. In order to assess if the primary sequence or structural element play more important regulatory roles, the CMV promoter-driven 5 UTR truncation mutant cDNA clones were directly transfected into the BHK-21 cell lines. We found that PRRSV tolerated the first 16 nucleotides sequence alteration of 5 UTR without losing virus viability. However, these revertant viruses contained a range of non-templated with unknown origin exogenous nucleotides in the repaired 5 end. Further analyses revealed that the 5 proximal stem-loop 1 (SL1) in the highly structured 5 UTR was invariably required for virus infectivity. Taken together, we conclude that authentic 5 -proximal primary sequence is nonessential, but the resultant structural elements are probably indispensable for PRRSV infectivity. 
 Title: Cis-acting structural element in 5 UTR is essential for infectivity of porcine reproductive and respiratory syndrome virus
[A]:
True