Problems like this are always tackled using an identity template for the elements that don't need to change:
<xsl:template match="*">
<xsl:copy>
<xsl:coupy-of select="@*"/>
<xsl:apply-templates/>
</xsl:copy>
</xsl:template>
coupled with specific templates for the elements that do need to change:
<xsl:template match="meta">
<xsl:apply-templates select="journalcode|issn"/>
</xsl:template>
<xsl:template match="article">
<xsl:apply-templates select="*"/>
<xsl:apply-templates select="meta/author"/>
</xsl:template>
Michael Kay
http://www.saxonica.com/
Author, XSLT Programmer's Reference and XPath 2.0 Programmer's Reference