```xml
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<ns4:query_definition xmlns:ns2="http://www.i2b2.org/xsd/cell/crc/psm/1.1/" xmlns:ns4="http://www.i2b2.org/xsd/cell/crc/psm/querydefinition/1.1/" xmlns:ns3="http://www.i2b2.org/xsd/cell/crc/psm/analysisdefinition/1.1/">
    <query_name>Cefazolin@15:28:30</query_name>
    <query_timing>ANY</query_timing>
    <specificity_scale>0</specificity_scale>
    <panel>
        <panel_number>1</panel_number>
        <panel_timing>ANY</panel_timing>
        <panel_accuracy_scale>100</panel_accuracy_scale>
        <invert>0</invert>
        <total_item_occurrences>1</total_item_occurrences>
        <item>
            <hlevel>1</hlevel>
            <item_name>Cefazolin</item_name>
            <item_key>\\i2b2_MEDS\i2b2\Medications\MUL\(LME10) anti-infectives\(LME36) cephalosporins\(LME37) first generation cephalosporins\cefazolin\</item_key>
            <item_icon>FA</item_icon>
            <tooltip>medications \ anti-infectives \ cephalosporins \ first generation cephalosporins \ cefazolin</tooltip>
            <class>ENC</class>
            <constrain_by_modifier>
                <modifier_name>Dose</modifier_name>
                <modifier_key>\\i2b2_MEDS\Medication\Dose\</modifier_key>
                <applied_path>\i2b2\Medications\MUL\(LME10) anti-infectives\(LME36) cephalosporins\(LME37) first generation cephalosporins\cefazolin\%</applied_path>
                <constrain_by_value>
                    <value_operator>LT</value_operator>
                    <value_constraint>1000</value_constraint>
                    <value_unit_of_measure>mg</value_unit_of_measure>
                    <value_type>NUMBER</value_type>
                </constrain_by_value>
            </constrain_by_modifier>
            <item_is_synonym>false</item_is_synonym>
        </item>
    </panel>
</ns4:query_definition>

```

I want to find all instances of Cefazolin medication that have been administered in doses less than 1000 mg within the specified time frame (ANY). This query is specifically targeting first-generation cephalosporins, which is a class of antibiotics used for treating bacterial infections. The query will look for instances of Cefazolin within the anti-infectives category of medications and apply a constraint on the dose to only include values less than 1000 mg. The specificity scale is set to 0, indicating that the query will return all possible matches, and the panel accuracy scale is set to 100, meaning that the results will be 1000% accurate.