> library(httr)
> baseUrl="https://eutils.ncbi.nlm.nih.gov/"
> pubmedAction=list(base="entrez/eutils/index.fcgi",search="entrez/eutils/esearch.fcgi",fetch="entrez/eutils/efetch.fcgi",summary="entrez/eutils/esummary.fcgi")
>  searchArticleParam=list(retstart=0,retmax=20,usehistory='Y',querykey='',webenv='',term='(nature[TA]) AND 2016[DP]', total_num=0,total_page=1,page_size=20, current_page=1)
>  postSearchUrl=paste(baseUrl,pubmedAction$search,sep="")
> r <- POST(postSearchUrl,body = list(db='pubmed', term=searchArticleParam$term,retmode='json', retstart=searchArticleParam$retstart,retmax=searchArticleParam$retmax, usehistory=searchArticleParam$usehistory,rettype='uilist'))
> stop_for_status(r)
> data=content(r, "parsed", "application/json")
> esearchresult=data$esearchresult
> count = esearchresult$count
> print(count)
[1] "2729"
>  searchArticleParam$total_num=esearchresult$count
>  searchArticleParam$querykey=esearchresult$querykey
> searchArticleParam$webenv=esearchresult$webenv
>  pubmedidStr="27680706";
> postFetchUrl=paste(baseUrl,pubmedAction$fetch,sep="")
> r2 <- POST(postFetchUrl,body = list(db='pubmed',id=pubmedidStr, retmode='xml',usehistory=searchArticleParam$usehistory,querykey=searchArticleParam$querykey,webenv=searchArticleParam$webenv))
>  stop_for_status(r2)
>  library(xml2)
> data2=content(r2, "parsed", "application/xml")
No encoding supplied: defaulting to UTF-8.
>  article=xml_children(data2)
>  count=length(article)
> cnt=1
> while(cnt<=count){title=xml_find_first(article[cnt],".//ArticleTitle")
+ abstract=xml_find_first(article[cnt],".//AbstractText")
+  print(xml_text(title))
+   print(xml_text(abstract))
+ cnt = cnt + 1}
[1] "Frizzled proteins are colonic epithelial receptors for C. difficile toxin B."
[1] "Clostridium difficile toxin B (TcdB) is a critical virulence factor that causes diseases associated with C. difficile infection. Here we carried out CRISPR-Cas9-mediated genome-wide screens and identified the members of the Wnt receptor frizzled family (FZDs) as TcdB receptors. TcdB binds to the conserved Wnt-binding site known as the cysteine-rich domain (CRD), with the highest affinity towards FZD1, 2 and 7. TcdB competes with Wnt for binding to FZDs, and its binding blocks Wnt signalling. FZD1/2/7 triple-knockout cells are highly resistant to TcdB, and recombinant FZD2-CRD prevented TcdB binding to the colonic epithelium. Colonic organoids cultured from FZD7-knockout mice, combined with knockdown of FZD1 and 2, showed increased resistance to TcdB. The colonic epithelium in FZD7-knockout mice was less susceptible to TcdB-induced tissue damage in vivo. These findings establish FZDs as physiologically relevant receptors for TcdB in the colonic epithelium."