Objective To explore the clinical significance of procalcitonin(PCT)in guiding the optimizing antimi-crobial treatment strategy in ventilator-associated pneumonia(VAP).Methods Sixty patients receiving mechanism ventilation for ≥48 hours in an intensive care unit between November 2011 and April 2013 were randomly divided into control group (n=29)and trail group (n=31),patients in control group stopped antimicrobial use according to guideline,patients in trail group stopped antimicrobial use according to serum procalcitonin level,duration of anti-microbial use and mechanical ventilation between two groups were compared.Results Days of mechanical ventila-tion,length of ICU stay,mortality rates between two groups were not significantly different(all P >0.05);antimi-crobial days in trail group was significantly less than control group([10.70 ±3.78]d vs [13.93 ±3.03 ]d)(t =4.484;P <0.001).Conclusion Serum procalcitonin level plays an important role in the rational use of antimicrobial agents in patient with VAP.

BACKGROUND:Finite element contact analysis was performed in premolars of lower mandible with enamelo-dentinal junction defects, which provided biomechanical evidence for the prevention of wedge-shaped defect and occlusion treatment.
OBJECTIVE:To analyze the effects of undermining damage of the enamelo-dentinal junction on the stress distribution of sclerous tissues of dental cervix.
METHODS:Triangle defects were established and models of wedge-shaped defect were designed in mandibular premolar along the enamelo-dentinal junction. The stresses during tightly biting and masticatory movement were simulated. Nonlinear contact analysis was conducted in sclerous tissues of mandibular premolar in the buccal cervical region.
RESULTS AND CONCLUSION:By simulating the stresses during tightly biting and masticatory movement, the stresses were concentrated in the defected regions of mandibular premolar at the enamelo-dentinal junction. With the defect length increased in size, the stress value and the magnitude of the stress field both increased. These indicated that the destruction of enamelo-dentinal junction altered stress distribution in the buccal cervical region. In the clinic, wedge-shaped defect should be fil ed promptly.

OBJECTIVETo study the distribution of stress of simulating teeth with wedge shaped defects in the cervical region.

METHODSThe models of anisotropic enamel of the mandibular first premolar and the opposite maxillary first premolar crown were created. A defect was introduced into the model of mandibular premolar in the buccal cervical region along the enamelo-dentinal junction (DEJ). The stress distribution in the cervical region of the mandibular premolar was investigated considering lateral condition simulating working micromotions. In this case, the stroke was applied to the maxillary first mandibular in a stepping procedure using nonlinear contact analysis.

RESULTSThe stresses were concentrated in the defect of the enamel and dentin at the DEJ in the condition of lateral loading. As the defect length increased in size, the peak maximum principal stress (MPS) value and the magnitude of the stress field along the DEJ both increased.

CONCLUSIONUndermined cervical DEJ had a significant effect on the stress distribution in the buccal cervical region.

Bicuspid ; Dental Enamel ; Dental Stress Analysis ; Dentin ; Finite Element Analysis ; Humans ; Mandible ; Maxilla