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Stability of blood alcohol concentration (BAC) in laboratory samples is of great importance when it is necessary to perform repeated analyses.We have analyzed the stability of BAC in 50 samples, which were taken from apprehended drivers, kept at -18ºC, without preserving agents. Quantitative analyses were performed using headspace sampling gas chromatography (HS-GC) with flame ionizing detection (FID). Samples were analyzed immediately after collection (C1), and after 60 (C60), 120 (C120) and 180 (C180) days. A group of 50 samples, which were kept closed for 180 days at -18ºC, was utilized as a control.We found a significant decrease in BAC between C1 and C180 (= 0.224; SD= 0.144; t = 10.98; p0.001), and between C1 and C60, C60 and C120, C120 and C180. There was a significant positive correlation (r=0.8) between starting concentration C1, and the value of BAC changes (ΔC). Linear regression analysis (R2=0.64) implies the degree of validity to the proposed model of ΔC change regarding initial BAC. There were significant changes in ΔC between the two groups.These data underline the significance of air chamber percent (CA%) and ethanol evaporation due to ventilation between liquid and gas phase as a mechanism of ethanol decay.

The admixture of clonidine or epinephrine to lidocaine for inferior alveolar nerve block was studied with regard to onset, duration, intensity of anaesthesia, postoperative analgesia, systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), heart rate (HR), ST segment depression ≥1 mm and cardiac arrhythmias. Forty healthy patients (ASA I) received 2 ml 2% lidocaine with clonidine (15 μg/ml; n = 20) or epinephrine (12.5 μg/ml; n = 20) in a double-blind fashion for lower third molar surgery. Duration and intensity were not different between groups, while onset was significantly different by subjective evaluation. The need for postoperative pain medication was significantly lower in the clonidine group. There was a significant decrease in SBP and MAP in both groups 35 min after administration of anaesthesia compared with basal values, while DBP was significantly lower only in the clonidine group. There was no significant difference in SBP, DBP and MAP between groups. HR was significantly increased in the epinephrine group 5 min after administration of anaesthesia and during surgery compared with the clonidine group and with basal values. The presented data suggest that clonidine could be a useful and safe alternative to epinephrine for intraoral block anaesthesia.

A series of periphyton, sediment, and water samples has been collected from the Kolubara River and its tributaries at selected locations, characterized by heavy industrialization, and analysed for stable isotopes by X-ray-fluorescence spectrometry. The results of measurements for stable metals revealed that the anthropogenic contribution essentially overwhelms the natural system of the catchment. Thus, concentrations of heavy metals near points of industrial discharge were significantly higher than background concentrations. The existing primary and secondary waste water-treatment plants associated with heavy industry of the area must therefore be revived, and control should be instituted at the sources of pollution. The bioaccumulation factors (BF), and sediment distribution coefficients (K(D)), and concentration ratios (CR) for sixteen stable isotopes were calculated. It is shown that the concentration ratios of periphyton over sediment for Mn, Zn, As, Sb, I, Ba, and Pb exceeded unity. Furthermore, the recorded partition coefficients were indicative of the distribution and mobility of the stable metals in the Kolubara River environment.

The effects of captopril and bradykinin on chorda tympani-induced salivation were studied in the submandibular gland of anesthetized cat. Captopril and bradykinin, but not des-Arg9-bradykinin, increased salivation evoked by electrical stimulation of chorda tympani. These potentiated effects of captopril and bradykinin were suppressed by Hoe-140, a kinin B2 receptor antagonist, or by concomitant addition of N(G)-nitro arginine methyl ester (L-NAME), a nitric oxide synthase inhibitor, and aspirin, a cyclooxygenase inhibitor. It appears that captopril potentiates chorda tympani-induced salivation through endogenously accumulated bradykinin, which acts on kinin B2 receptors, mediating production of nitric oxide and cyclooxygenase products.

A new approach to decoupled control of large-scale non-linear systems is applied to a dynamic flight control. Control synthesis is performed in two steps. First the nominal, programmed control is synthesized using the complete model of flight dynamics. This nominal control should realize the nominal trajectory under ideal conditions with no perturbations. In the second step the tracking of the nominal trajectory is realized. The system is viewed as a set of decoupled subsystems and for each subsystem local control is synthesized. Then, the stability of the overall system is analyzed and the global control is introduced to compensate coupling among some of the subsystems. A particular choice of subsystems in a case of flight control and of local and global control synthesis is proposed. A simulation of flight control with the proposed control law is also presented.