Chronic valproic acid intoxication in epileptology: diagnosis and treatment

Valproic acid (VA) is used in epileptology for the basic and additional control of simple and complex focal seizures, absences, generalized tonicclonic seizures, and myoclonus. Information has been recently stored on cases of chronic overdosage of VA due to its blood accumulation. These conditions are described in the use of both high and average therapeutic doses of VA preparations in patients with a genetically determined delay in metabolism. The paper presents current methods for clinical and laboratory diagnosis and correction of chronic intoxication when valproic acid preparations are administered during the prehospital, hospital and rehabilitation phases of treatment. The authors note that a personalized approach is of importance for dose adjustment and prediction of unwanted adverse drug reactions associated with the use of VA preparations

Laser Scanning Microscopy of HTS Films and Devices

The work describes the capabilities of Laser Scanning Microscopy (LSM) as a spatially resolved method of testing high_Tc materials and devices. The earlier results obtained by the authors are briefly reviewed. Some novel applications of the LSM are illustrated, including imaging the HTS responses in rf mode, probing the superconducting properties of HTS single crystals, development of twobeam laser scanning microscopy. The existence of the phase slip lines mechanism of resistivity in HTS materials is proven by LSM imaging.Comment: 17 pages, 21 figures, Submitted to Fizika Nizkikh Temperatur (Low Temperature Physics

Investigation of new modification strategies for PVA membranes to improve their dehydration properties by pervaporation

International audienceNovel supported membranes based on polyvinyl alcohol (PVA) were developed using two strategies: first, by the modification of the PVA network, via so-called bulk modification, with the formation of the selective layer accomplished through the introduction of fullerenol and/or poly(allylamine hydrochloride), and second, by the functionalization of the surface with successive depositions of multilayered films of polyelectrolytes, such as poly(allylamine hydrochloride) and poly(sodium 4-styrenesulfonate) on the PVA surface. The membrane surface modifications were characterized by scanning electron microscopy and contact angle measurements. The modified PVA membranes were examined for their dehydration transport properties by the perva-poration of isopropyl alcohol-water (80/20% w/w), which was chosen as a model mixture. Compared with the pristine PVA membrane, the main improvement was a marked increase in permeance. It was found that the surface modifications mainly gave rise to a higher global flux but with a strong reduction in selectivity. Only the combination of both bulk and surface modifications with PEL could significantly increase the flux with a high water content in the permeate (over 98%). Lastly, it should be noted that this study developed a green procedure to prepare innovative membrane layers for dehydration, making use of only water as a working medium

Variations in characteristics of the barents branch of the Atlantic Water in the Nansen Basin under the influence of atmospheric circulation over the Barents Sea

The thermohaline structure of the Arctic Basin (AB) of the Arctic Ocean (AO) is determined to a great extent by an intermediate water layer existing under ice at a depth varying from 100 to 700–1000 m. The water layer is formed by warm North Atlantic Water (AW), which enters the AB by two ways: through Fram Strait and the Barents Sea (Fig. 1). The AW arriving to the AB via Fram Strait extends further eastward along the continental slope of the Eurasian Arctic region and forms the Fram Branch (FBAW). The Barents Branch of the AW (BBAW) was formed by the North Atlantic Water entering the Barents Sea between the Spitsbergen Archipelago and the Scandinavian Peninsula. Both branches merge in the northern Kara Sea

Fractional ac Josephson effect in unconventional superconductors

For certain orientations of Josephson junctions between two p_x-wave or two d-wave superconductors, the subgap Andreev bound states produce a 4pi-periodic relation between the Josephson current I and the phase difference phi: I ~ sin(phi/2). Consequently, the ac Josephson current has the fractional frequency eV/h, where V is the dc voltage. In the tunneling limit, the Josephson current is proportional to the first power (not square) of the electron tunneling amplitude. Thus, the Josephson current between unconventional superconductors is carried by single electrons, rather than by Cooper pairs. The fractional ac Josephson effect can be observed experimentally by measuring frequency spectrum of microwave radiation from the junction.Comment: 8 pages, 3 figures, RevTEX 4; v2. - minor typos corrected in proof

Current-voltage characteristic of narrow superconducting wires: bifurcation phenomena

The current-voltage characteristics of long and narrow superconducting channels are investigated using the time-dependent Ginzburg-Landau equations for complex order parameter. We found out that the steps in the current voltage characteristic can be associated with bifurcations of either steady or oscillatory solution. We revealed typical instabilities which induced the singularities in current-voltage characteristics, and analytically estimated period of oscillations and average voltage in the vicinity of the critical currents. Our results show that these bifurcations can substantially complicate dynamics of the order parameter and eventually lead to appearance of such phenomena as multistability and chaos. The discussed bifurcation phenomena sheds a light on some recent experimental findings

COMPARATIVE EFFICACY OF EXTRACORPOREAL SHOCKWAVE LITHOTRIPSY AND RETROGRADE INTRARENAL SURGERY IN THE TREATMENT OF CALCIUM OXALATE NEPHROLITHIASIS

Objective To evaluate the results of extracorporeal shockwave lithotripsy (ESWL) versus retrograde intrarenal surgery (RIRS) for the treatment of calcium oxalate nephrolithiasis, as well as the damaging effects on renal function, taking into account the dynamics of blood cystatin C and urine beta2-microglobulin.Material and Methods Of 94 patients with calcium oxalate nephrolithiasis aged 23–78 included in the study,  42 patients were classified as having undergone ESWL (group I) and 52 patients as having undergone RIRS (group II). Group II patients were then stratified into subset 2A (n = 32) as having undergone RIRS through rigid ureteroscope and subset 2B (n = 20) as having undergone RIRS through flexible ureteroscope. We performed plain urography and nephrosonography at 24–48 hours postoperatively and unenhanced computed tomography 4–6 weeks after surgery. We measured concentrations of serum cystatin C and urinary beta2-microglobulin as a marker for kidney damage. In group I, samples of peripheral blood andurine were taken before and after the first, third sessions and 30 days after the last ESWL session. In group  II, samples were analyzed before surgery, on the first and 30th postoperative days.Results The average size of calculi in the group with RIRS was 16.91 ± 2.79 mm, in the group with ESWL  12.31 ± 2.27 mm. The need for reoperation after RIRS was 19.2%, which was lower than after ESWL. Stone-free effect (no stones, or residual stones less than 3 mm) was observed in 95% of cases in patients with RIRS, and in 78% with ESWL. Group I patients demonstrated an increase in the blood leukocytes total number more often than subsets 2A (rigid RIRS) and 2B (flexible RIRS) patients. Leukocyturia was also a more common complication in group I. In the RIRS group, there was no statistically significant change in the level of blood cystatin C and urine beta2-microglobulin, on the contrary, a moderate increase in the endogenous marker of cystatin C was noted after one ESWL session. The increase in urine beta2-microglobulin levels in patients after the first and third ESWL sessions was significantly higher than after RIRS.Conclusion Flexible RIRS may be suggested as the preferred procedure for patients requiring additional protection of renal function in the treatment of renal stones less than 20 mm. ESWL of stones less than 20 mm can be used as an alternative treatment, since it is characterized by a rather long period of stone eradication from the urinary tract, a high frequency of residual calculi after the procedure, and also has a damaging effect on the renal tissue

Coherent Rabi response of a charge-phase qubit under microwave irradiation

We report on radio-frequency measurements of the charge-phase qubit being under continuous microwave irradiation in the state of weak coupling to a radio-frequency tank circuit. We studied the rf impedance dependence on the two important parameters such as power of microwave irradiation whose frequency is close to the gap between the two lowest qubit energy levels, and temperature of the internal heat bath. We have found that backaction effects of the qubit on the rf tank, and vice versa, tank on the qubit, lead to a negative as well as a positive real part of the qubit impedance Re$Z(\omega)$ seen by the tank. We have implemented noise spectroscopy measurements for direct impedance readout at the extreme points corresponding to maximum voltage response and obtained absolute values of about 0.017 $\Omega$ for the negative and positive Re$Z(\omega)$. Our results demonstrate the existence and persistence of the coherent single- and multi-photon Rabi dynamics of the qubit with both negative and positive dynamic resistance inserted into the tank in the temperature range of 10 to 200 mK.Comment: 11 pages, 9 figure