فهرست مطالب طاهره پارسا

Cenozoic acidic volcanic rocks at the south of Qezel Ozan River are located within the Western Alborz-Azarbaijan magmatic zone and northern part of the Iranian-Turkish Plateau. The Oligocene acidic lavas in north part of Zanjan show rhyolitic to dacitic composition.  Hyaloporphyritic to hyalomicrolithic porphyritic textures are the main texture in these rocks. They were erupted along the main faults in this area. Feldspars, biotites and hornblendes are the major phenocrysts which are embedded in a glass matrix or micro phenocrysts of felsic and mafic minerals. By Geochemical studies it is indicated that these rocks have high-K calc-alkaline to shoshonitic nature and classified as meta-aluminous and I-type acidic rocks. In the chondrite normalized rare earth elements diagram, these rocks demonstrate LREE enrichment and high LREE/HREE ratio. Enrichment in LREE and depletion in HREE is characteristic of the calc-alkaline rocks in active continental margins. Furthermore, these rocks show enrichment in LILEs and negative anomalies of HFSEs (Ti, Nb and Ta) which is the feature of magmatic rocks associated with Post-COLG subduction zones. The geochemical evidences suggest that the parental acidic magma is resulted from partial melting of lower crust as a result of pressure reduction during the local tension mechanism.

Video-assisted thoracoscopic surgery (VÂTS) has been developed as a minimally invasive alternative approach for various diagnostic and therapeutic thoracic operations that previously required open thoracotomy. Postoperative pain is less after VÂTS than after conventional thoracic surgery، but is still significant. The purpose of this randomized double blind clinical trial was to compare the effect of interpleural morphine analgesia with traditional intravenous morphine administration on pain and supplemental analgesic usage after VÂTS.

30 Âmerican Society of Ânesthesiologists classes Ï and ÏÏ patients who had VÂTS under general anesthesia were randomly divided into two equal groups. Ât the completion of operation، a catheter was placed in the pleural space under thoracoscopic vision. Patients received a single bolus of 0. 1 mg·kg-1 of morphine either interpleurally or intravenously. During the first postoperative 8 hours، pain score at rest and on coughing، supplemental analgesic requirements، mean arterial pressure، heart rate، arterial blood oxygen saturation، degree of sedation، and side effects were monitored every one hour. The pain severity was evaluated by visual analogue pain scales (VÂS، 0-10).

No statistically significant difference was observed between the groups in relation to pain intensity، hemodynamic variables، or side effects during study period. Çonclusion: Ïnterpleural morphine did not provide superior analgesia compared with intravenous morphine after thoracoscopic surgery.