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The spinel-structure CuIr2S4 compound displays a rather unusual orbitally-driven three-dimensional Peierls-like insulator–metal transition. The low-T symmetry-broken insulating state is especially interesting due to the existence of a metastable irradiation-induced disordered weakly conducting state. Here we study intense femtosecond optical pulse irradiation effects by means of the all-optical ultrafast multi-pulse time-resolved spectroscopy. We show that the structural coherence of the low-T broken symmetry state is strongly suppressed on a sub-picosecond timescale above a threshold excitation fluence resulting in a structurally inhomogeneous transient state which persists for several-tens of picoseconds before reverting to the low-T disordered weakly conducting state. The electronic order shows a transient gap filling at a significantly lower fluence threshold. The data suggest that the photoinduced-transition dynamics to the high-T metallic phase is governed by first-order-transition nucleation kinetics that prevents the complete ultrafast structural transition even when the absorbed energy significantly exceeds the equilibrium enthalpy difference to the high-T metallic phase. [ABSTRACT FROM AUTHOR]

Background/Aim. Surgical extraction of impacted lower third molars is inevitably followed by the postoperative occurrence of trismus, swelling, and pain sensations to some degree. Corticosteroids (dexamethasone in particular) are commonly used drugs in the prevention of these complications. The aim of this study was to determine the effectiveness of dexamethasone in the prevention of postoperative complications, edema, trismus, and pain after the surgical extraction of impacted lower third molars, depending on the method of its administration. Methods. This prospective study involved 30 healthy patients, aged 18 years and above, of both sexes, with fully impacted lower third molar – class I or II and position B or C, according to Pell and Gregory classification system and vertical position according to Winter classification. All patients were divided randomly into three groups de-pending on the way of dexamethasone administration: oral – dexamethasone administered in the form of oral tablets in a dose of 4 mg one hour before the surgery; submucosal – dexamethasone solution administered submucosally in a dose of 4 mg in the area of the buccal sulcus, after the inferior alveolar nerve block anesthesia and additional anesthesia for the buccal nerve; intramuscular – dexamethasone solution administered intramuscularly in a dose of 4mg into the area of the deltoid muscle, right before the intervention. Preoperatively and at every follow-up (on the first, second, and seventh day postoperatively), interincisal distance, the degree of edema, and the level of pain with the use of a visual analog scale (VAS) were measured. On the seventh postoperative day, the total number of analgesics taken by the patients was recorded. Results. In the postoperative period, there was no statistically significant difference be-tween the examined groups in terms of effectiveness in swelling, trismus, and pain reduction (p > 0.05). Conclusion. There is no significant difference in dexamethasone effectiveness in postoperative trismus, swelling, and pain reduction after the third lower molar surgery, regarding the route of administration – oral, intramuscular, or local submucosal.

Calculates the vibrational spectra of the different oxidation states of tetrakis(dimethylamino)ethylene using structural optimization and normal-mode calculations. Molecular structure; Stretch vibration frequency; Axial torsional angle.

Background/Aim: The objective of the study was to compare cytological diagnoses using transepithelial cytology (oral brush biopsy) with histopathological diagnoses obtained by incisional biopsy in patients with benign lesions, oral potentially malignant disorders and oral squamous cell carcinoma. Material and Methods: The study included 57 patients. Brush biopsy was performed after local anaesthesia administration using the cervical brush. It was immediately followed by an incisional biopsy. Modified Bethesda System was used for cytological analysis and correlated with histopathological diagnoses according to intraepithelial neoplasia. Results: Good agreement was shown between cytological and histopathological diagnosis (kappa = 0.791). The sensitivity of the study was 92.85%, specificity 100%, positive predictive value (PPV) was 100% and negative predictive value (NPV) 93.54%. Conclusions: Oral brush biopsy, which allows the collection of epithelial cells of all layers can provide fast, precise and efficient cytological results which are in good agreement with the 'gold standard' - incisional biopsy followed by histopathology.