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</LabelSeparator><Level>2</Level><ElementName>posc_GoingConcernDisclosureTextBlock</ElementName><ElementPrefix>posc_</ElementPrefix><IsBaseElement>false</IsBaseElement><BalanceType>na</BalanceType><PeriodType>duration</PeriodType><IsReportTitle>false</IsReportTitle><IsSegmentTitle>false</IsSegmentTitle><IsCalendarTitle>false</IsCalendarTitle><IsEquityPrevioslyReportedAsRow>false</IsEquityPrevioslyReportedAsRow><IsEquityAdjustmentRow>false</IsEquityAdjustmentRow><IsBeginningBalance>false</IsBeginningBalance><IsEndingBalance>false</IsEndingBalance><IsReverseSign>false</IsReverseSign><PreferredLabelRole>terseLabel</PreferredLabelRole><FootnoteIndexer /><Cells><Cell FlagID="0" ContextID="P01_01_2013To06_30_2013" UnitID=""><Id>1</Id><IsNumeric>false</IsNumeric><IsRatio>false</IsRatio><DisplayZeroAsNone>false</DisplayZeroAsNone><NumericAmount>0</NumericAmount><RoundedNumericAmount>0</RoundedNumericAmount><NonNumbericText>              &lt;table border="0" style="clear:both;width:100%; table-layout:fixed;"&gt;  &lt;tr&gt;  &lt;td&gt;&lt;/td&gt;  &lt;/tr&gt;  &lt;/table&gt;    &lt;div style="clear:both; FONT-FAMILY:Times New Roman;FONT-SIZE: 10pt;MARGIN: 0pt 0px; FONT: 10pt Times New Roman, Times, Serif "&gt;  &lt;div style="clear:both; FONT-FAMILY:Times New Roman;FONT-SIZE: 10pt;MARGIN: 0in 0in 0pt; FONT-SIZE: 10pt"&gt;  &lt;table style="clear:both;WIDTH: 100%; BORDER-COLLAPSE: collapse"  border="0" cellspacing="0" cellpadding="0" width="100%"&gt;  &lt;tr&gt;  &lt;td style="BORDER-BOTTOM: #f0f0f0; BORDER-LEFT: #f0f0f0; PADDING-BOTTOM: 0in; BACKGROUND-COLOR: transparent; PADDING-LEFT: 0in; WIDTH: 7%; PADDING-RIGHT: 0in; BORDER-TOP: #f0f0f0; BORDER-RIGHT: #f0f0f0; PADDING-TOP: 0in"   valign="top" width="7%"&gt;  &lt;div style="clear:both;MARGIN: 0in 0in 0pt"&gt;&lt;b&gt;&lt;font style="COLOR: black; FONT-SIZE: 10pt"&gt;3.&lt;/font&gt;&lt;/b&gt;&lt;font style="FONT-SIZE: 10pt"&gt;&lt;/font&gt;&lt;/div&gt;  &lt;/td&gt;  &lt;td style="BORDER-BOTTOM: #f0f0f0; BORDER-LEFT: #f0f0f0; PADDING-BOTTOM: 0in; BACKGROUND-COLOR: transparent; PADDING-LEFT: 0in; WIDTH: 93%; PADDING-RIGHT: 0in; BORDER-TOP: #f0f0f0; BORDER-RIGHT: #f0f0f0; PADDING-TOP: 0in"   valign="top" width="93%"&gt;  &lt;div style="clear:both;MARGIN: 0in 0in 0pt"&gt;&lt;b&gt;&lt;font style="COLOR: black; FONT-SIZE: 10pt"&gt;Going Concern&lt;/font&gt;&lt;/b&gt;&lt;font  style="FONT-SIZE: 10pt"&gt;&lt;/font&gt;&lt;/div&gt;  &lt;/td&gt;  &lt;/tr&gt;  &lt;/table&gt;  &lt;/div&gt;    &lt;div style="clear:both; FONT-FAMILY:Times New Roman;FONT-SIZE: 10pt;MARGIN: 0in 0in 0pt"&gt;  &lt;font style="FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/div&gt;    &lt;div style="clear:both; FONT-FAMILY:Times New Roman;FONT-SIZE: 10pt;MARGIN: 0in 0in 0pt 0.5in"   align="justify"&gt;&lt;font style="FONT-SIZE: 10pt"&gt;Since inception, the  Company has expended substantial resources on research and  development and sustained losses. Due to the limited number of  systems sold or placed into service each year, revenues have  fluctuated significantly from year to year and have not been  sufficient to be operationally profitable. The Company had an  accumulated deficit of $118,759,000 and a stockholders&amp;#8217;  deficit of $7,635,000 at June 30, 2013. The Company will need to  increase sales and apply the research and development advancements  to achieve profitability in the future. The Company will need to  resume and increase sales of PET and radiopharmaceutical systems,  services, radipharmaceuticals and radioisotope sales and apply the  research and development advancements to achieve profitability in  the future. There can be no assurance that the Company will  continue to be successful in selling products.&lt;/font&gt;&lt;/div&gt;    &lt;div style="clear:both; FONT-FAMILY:Times New Roman;FONT-SIZE: 10pt;TEXT-INDENT: 0.5in; MARGIN: 0in 0in 0pt"   align="right"&gt;&lt;font style="FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/div&gt;    &lt;div style="clear:both; FONT-FAMILY:Times New Roman;FONT-SIZE: 10pt;MARGIN: 0in 0in 0pt 0.5in"   align="justify"&gt;&lt;font style="COLOR: black; FONT-SIZE: 10pt"&gt;The  Company had cash and cash equivalents of $370,000 at June 30, 2013.  At the same date, the Company had accounts payable and accrued  liabilities of $1,596,000,&lt;/font&gt; &lt;font style="FONT-SIZE: 10pt"&gt;and  a negative working capital of $8,462,000.&lt;font style="COLOR: black"&gt;&lt;/font&gt;Working capital requirements for the upcoming  year will reach beyond our current cash balances. The Company plans  to continue to raise funds as required through equity and debt  financing to sustain business operations. These factors raise  substantial doubt about the Company&amp;#8217;s ability to continue as  a going concern.&lt;/font&gt;&lt;/div&gt;    &lt;div style="clear:both; FONT-FAMILY:Times New Roman;FONT-SIZE: 10pt;MARGIN: 0in 0in 0pt 0.5in"   align="justify"&gt;&lt;font style="FONT-SIZE: 10pt"&gt;&amp;#160;&lt;/font&gt;&lt;/div&gt;    &lt;div style="clear:both; FONT-FAMILY:Times New Roman;FONT-SIZE: 10pt;MARGIN: 0in 0in 0pt 0.5in"   align="justify"&gt;&lt;font style="FONT-SIZE: 10pt"&gt;There can be no  assurance that the Company will be successful in implementing its  business plan and ultimately achieving operational profitability.  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