The flow of two zinc oxide-eugenol-based endodontic sealers

Background/Aim. Endodontic sealers (ES) for obturation are usually prepared with a slight variation of their components both on purpose or unintentionally. Considering that fact, as well as a frequent use of compaction techniques with the applied force to gutta-percha and ES of 1-3 kg, the aim of this study was to investigate the flow of two zinc-oxide eugenol ES in regard to the applied force and a variation of sealer’s components. Methods. The experimental group samples of both ES were prepared according to the manufacturer’s instructions, applied between pair of glass slabs and loaded by weights of 1 and 2 kg, respectively (American National Standard, Specification No. 57). Some samples of one ES were prepared as thick consistency with 10% more powder and some as thin mixture with 10% less powder than the standard prescription. These semples had been exposed to the load of 2 kg. The control group included samples of both ES prepared as standard prescription but exposed to the weight of one glass slab only. The spread ES appeared as a regular circle 10 min upon mixing and weighting. Measuring of the circle diameter was done by an orthodontic ruler. The flow of the used ES was considered the function of its spread diameter. Results. Application of 1 vs 2 kg load for both regularly mixed sealers in the scope of disk diameter (flow) was statistically insignificant (p > 0.05). This means that the stated null hypothesis that there would be no significant difference in flow rate among the regularly mixed sealers at the level of α = 0.05 is accepted. The findings about difference in the disk diameter in regard to mixing variation of Endomethasone indicate that the null hypothesis that there would be no significant difference in flow rate between the regular and thick mixed mass at the level of α = 0.05 is accepted. In the comparison of regular and thin mix a significant difference was noted and the null hypotesis is rejected (p < 0.01). The control group results displayed Roth 801 as less viscous than Endomethasone sealer (p < 0.01). Conclusion. Application of 1 or 2 kg pressure on the samples of both exposed sealers does not significantly affect the flow values as well as comparison of the regular to thick consistency of Endomethasone while comparison of its regular to thin mass shows a significant difference

Repetitive transcranial magnetic stimulation in bipolar depression: Another puzzle of manic switch?

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Neurophysiological evaluation of patients with degenerative diseases of the cervical spine

Bacground/Aim. Diagnostic protocol for patients with degenerative diseases of the cervical spine demands, in parallel with neuroimaging methods, functional evaluation through neurophysiological methods (somatosensitive and motor evoked potentials and electromyoneurography) aiming to evaluate possible subclinical affection of spinal medula resulting in neurological signs of long tract abnormalities. Considering diversities of clinical outcomes for these patients, complex diagnostic evaluation provides a prognosis of the disease progression. Methods. The study included 21 patients (48.24 ± 11.01 years of age) with clinical presentation of cervical spondylarthropathy, without neuroradiological signs of myelopathy. For each patient, in addition to conventional neurophysiological tests (somatisensory evoked potentials - SSEP, motor evoked potentials - MEP, electromyoneurography - EMG, nerve conduction studies), we calculated central motor conduction time (CMCTF), as well the same parameter in relation to a different position of the head (maximal anteflexion and retroflexion), so-called dynamic tests. Results. Abnormalities of the peripheral motor neurone by conventional EMNeG was established in 2/3 of the patients, correponding to the findings of root condution time. Prolonged conventional CVMPF were found in 29% of the patients, comparing to 43% CVMPF abnormalities found with the dynamic tests. In addition, the SSEP findings were abnormal in 38% of the patients with degenerative diseases of the cervical spine. Conclusion. An extended neurophysiological protocol of testing corticospinal functions, including dynamic tests of central and periheral motor neurons are relevant for detection of subclinical forms of cervical spondylothic myelopathy, even at early stages. In addition to the conventional neurophysiological tests, we found usefull to include the dynamic motor tests and root conduction time measurement in diagnostic evaluation

Homeostatic Modulation of Stimulation-Dependent Plasticity in Human Motor Cortex

Since recently, it is possible, using noninvasive cortical stimulation, such as the protocol of paired associative stimulation (PAS), to induce the plastic changes in the motor cortex, in humans that mimic Hebb's model of learning. Application of TMS conjugated with peripheral electrical stimulation at strictly coherent temporal manner lead to convergence of inputs in the sensory-motor cortex, with the consequent synaptic potentiation or weakening, if applied repetitively. However, when optimal interstimulus interval (ISI) for induction of LTP-like effects is applied as a single pair, Motor evoked potential (MEP) amplitude inhibition is observed, the paradigm known as short-latency afferent inhibition (SLAI). Aiming to resolve this paradox, PAS protocols were applied, with 200 repetitions of TMS pulses paired with median nerve electrical stimulation, at ISI equal to individual latencies of evoked response of somatosensory cortex (N-20) (PASLTP), and at ISI of N-20 shortened for 5 msec (PASLTD) protocols that mimic LTP-like changes in the human motor cortex. MEP amplitudes before, during and after interventions were measured as an indicator based on output signals originating from the motor system. Post-intervention MEP amplitudes following the TMS protocols of PASLTP and PASLTD were facilitated and depressed, respectively, contrary to MEP amplitudes during intervention. During PASLTP MEP amplitudes were significantly decreased in case of PASLTP, while in the case of PASLTD an upward trend was observed. In conclusions, a possible explanation for the seemingly paradoxical effect of PAS can be found in the mechanism of homeostatic modulation of plasticity. Those findings indicate the existence of complex relationships in the development of plasticity induced by stimulation, depending on the level of the previous motor cortex excitability

Optical Emission Lines and the X-Ray Properties of Type 1 Seyfert Galaxies

In this contribution we report on the study of the optical emission lines and X-ray spectra of a sample of Type 1 AGNs, collected at the Sloan Digital Sky Survey database and observed by the XMM Newton satellite. Exploiting the different instruments carried onboard XMM, we identify the spectral components of the soft and hard energy bands (in the range from 0.3 keV up to 10 keV). The properties of the X-ray continuum and of the Fe Kalpha line feature are investigated in relation to the optical broad emission line profiles and intensity ratios. The resulting picture of emission, absorption and reflection processes is interpreted by means of a BLR structural model that was developed on the basis of independent optical and radio observations.Comment: 6 pages, 3 figures, Proceedings of the VIII Serbian Conference on Spectral Line Shapes in Astrophysics, accepted for publication on Baltic Astronomy. Corrected typos in V

RXJ 0921+4529: a binary quasar or gravitational lens?

We report the new spectroscopic observations of the gravitational lens RXJ 021+4529 with the multi-mode focal reducer SCORPIO of the SAO RAS 6-m telescope. The new spectral observations were compared with the previously observed spectra of components A and B of RXJ 0921+4529, i.e. the same components observed in different epochs. We found a significant difference in the spectrum between the components that cannot be explained with microlensing and/or spectral variation. We conclude that RXJ 0921+4529 is a binary quasar system, where redshifts of quasars A and B are 1.6535 +/- 0.0005 and 1.6625 +/- 0.0015, respectively.Comment: 6 pages, 5 figures, accepted for publication in The Astrophysical Journal Letter

Are Boltzmann Plots of Hydrogen Balmer lines a tool for identifying a subclass of S1 AGN?

It is becoming clear that we can define two different types of nearby AGN belonging to the Seyfert 1 class (S1), on the basis of the match of the intensities of their Broad Balmer Lines (BBL) with the Boltzmann Plots (BP). These two types of S1 galaxies, that we call BP-S1 and NoBP-S1, are characterized, in first approximation, by Broad Line Regions (BLR) with different structural and physical properties. In this communication, we show that these features can be well pointed out by a multi-wavelength analysis of the continuum and of the broad recombination Hydrogen lines, that we carry out on a sample of objects detected at optical and X-ray frequencies. The investigation is addressed to verify whether BP-S1 are the ideal candidates for the study of the kinematical and structural properties of the BLR, in order to derive reliable estimates of the mass of their central engine and to constrain the properties of their nuclear continuum spectrum.Comment: 26 pages, 4 figures (1 multi-paged). Accepted for publication on Advances in Space Research. Contribution to the IX SCSLS

Neuspeh sprečavanja razvoja intermedijernog sindroma kod akutnog trovanja organofosfornim insekticidima primenom oksima i atropina

Introduction. Intermediate syndrome (IMS) was described a few decades ago, however, there is still a controversy regarding its exact etiology, risk factors, diagnostic parameters and required therapy. Considering that acute poisonings are treated in different types of medical institutions this serious complication of organophosphate insecticide (OPI) poisoning is frequently overlooked. The aim of this paper was to present a case of IMS in organophosphate poisoning, which, we believe, provides additional data on the use of oxime or atropine. Case report. After a well-resolved cholinergic crisis, the patient developed clinical presentation of IMS within the first 72 h from deliberate malathion ingestion. The signs of IMS were weakness of proximal limb muscles and muscles innervated by motor cranial nerves, followed by the weakness of respiratory muscles and serious respiratory insufficiency. Malathion and its active metabolite were confirmed by analytical procedure (liquid chromatography-mass spectrometry). Pralidoxime methylsulphate, adiministered as a continuous infusion until day 8 (total dose 38.4 g), and atropine until the day 10 (total dose 922 mg) did not prevent the development of IMS, hence the mechanical ventilation that was stopped after 27 h had to be continued until the day 10. Conclusion. Continuous pralidoxime methylsulphate infusion with atropine did not prevent the development of IMS, most likely due to the delayed treatment and insufficient oxime dose but also because of chemical structure and lipophilicity of ingested OPI. A prolonged intensive care monitoring and respiratory care are the key management for the intermediate syndrome.Uvod. Intermedijerni sindrom (IMS) opisan je pre nekoliko decenija, međutim i dalje postoje kontroverze u vezi sa njegovom etiologijom, faktorima rizika, dijagnostičkim parametrima i potrebnom terapijom. S obzirom na to da se akutna trovanja leče u medicinskim ustanovama različitog tipa, ova teška komplikacija akutnih trovanja organofosfornim insekticidima (OFI) često se ne prepoznaje. Cilj rada bio je da se prikaže slučaj akutnog trovanja organofosfornim insekticidom koji će dati dodatne podatke o upotrebi oksima i atropina. Prikaz bolesnika. Nakon kupirane holinergičke krize kod bolesnika, 72 h od namerne ingestije malationa, došlo je do razvoja kliničke slike IMS. Znaci IMS su uključivali slabost mišića gornjih ekstremiteta i mišića inervisanih motornim kranijalnim nervima, što je bilo praćeno slabošću respiratorne muskulature i teškom respiratornom insuficijencijom. Malation i njegov aktivni metabolit potvrđeni su analitičkom procedurom (tečna hromatografijamasena spektrometrija). Kontinuiranom infuzijom pralidoksim metilsulfata do osmog dana (ukupno 38,4 g) i atropina do desetog dana (ukupna doza 922 mg), nije sprečen razvoj IMS, te je mehanička ventilacija, koja je prekinuta nakon 27 h, morala biti nastavljena do desetog dana. Zaključak. Kontinuiranom infuzijom pralidoksim-metilsulfata i atropina nije sprečen razvoj IMS, najverovatnije zbog odloženog početka lečenja i nedovoljne doze primenjenog oksima, ali i hemijske strukture i lipofilnosti ingestiranog OFI. Istaknut je značaj produžene opservacije u jedinici intenzivne nege i respiratorne podrške u lečenju intermedijernog sindroma

The combined effect of noninvasive cortical stimulation and motor training on hand motor deficit in chronic stroke

Sve veći broj dokaza podržava efikasnost primene transkranijalne stimulacije jednosmernom strujom (tSJS) u rehabilitaciji pacijenata sa hroničnim oštećenjem motorne funkcije ruke usled moždanog udara. Pored toga se smatra da plasticitet indukovan kombinacijom stimulacije motorne kore i intenzivne upotrebe zahvaćenog ekstremiteta može biti posebno korisna metoda za oporavak motornih funkcija u ove grupe pacijenata. Cilj: U ovoj studiji, istraživali smo i poredili efekte kombinovane primene aktivne tSJS i specifičnog motornog treninga (MT) u odnosu na lažnu (sham) tSJS sa MT (kontrolna procedura) na oporavak hroničnog motornog deficita šake nakon moždanog udara. Metode: Trideset pacijenata sa hroničnim motornim deficitom nastalog usled MU pre više od 9 meseci su metodom randomizacije raspoređeni u grupu sa aktivnim tretmanom (stvarna tSJS + MT) ili u kontrolnu grupu (lažna tSJS + MT) u skladu sa dvostrukoslepim, placebo-kontrolisanim, uporednim dizajnom ove studije. Svaka grupa je sprovodila MT u trajanju 45 min dnevno (ukupno 10 sesija tokom 2 nedelje). Ovom treningu je neposredno prethodilo 20 minuta aktivne anodne tSJS, primenjene iznad oštećenog regiona motorne kore intenziteta od 2 mA, ili 20 minuta lažne anodne tSJS, iznad istog regiona i istog trajanja. Modifikovani test funkcije šake prema Jebsen- Taylor-u (mJTt) je korišćen kao primarni parametar za procenu ishoda. Snaga stiska šake merena dinamometrijom i skala za gornje ekstremitete prema Fugl-Meyer-u su bili sekundarni ishodi. Evaluacije su sprovođenje neposredno pre započinjanja tretmana (T0), nakon prvog tretmana (T1), nakon desetodnevne primene tretmana (T2) i 30 dana po prestanku tretmana (T3). Podgrupa pacijenata (ukupno 21) je dodatno testirana pre (T0) i posle tretmana (T2) metodom transkranijalne magnetne stimulacije koja omogućuje evaluaciju stepena nadražljivosti motorne kore mozga putem merenja praga motornog podražaja u mirovanju i pri blagoj mišićnoj kontrakciji, kao i amplitude motornog evociranog potencijala...A growing body of evidence supports the effectiveness of transcranial direct current stimulation (tDCS) in rehabilitation of patients with hand motor impairment in the chronic phase of stroke. Furthermore, it is assumed that the combination of stimulation- and practice-induced plasticity may be especially beneficial for this group of patients. Objective: To compare the combined effects of anodal tDCS and specific motor training (MT) to sham tDCS and MT (control) on hand motor deficit in patients with chronic stroke. Methods: A total of 30 patients ≥9 months post-stroke were randomly assigned to an active treatment group (real tDCS+MT) or a control group (sham tDCS+MT) in this parallel, two-arm, double-blind, sham-controlled study. MT was administered for 45 min/day (10 sessions for 2 weeks) and preceded by 20 minutes of either 2 mA anodal tDCS or sham tDCS over the ipsilesional primary motor cortex. A modified Jebsen- Taylor Hand Function Test (mJTt) was the primary outcome measure, with handgrip dynamometer and upper limb Fugl-Meyer (ULFM) assessments serving as secondary outcomes. These assessments were administered before commencing the treatment (T0), after the first treatment on day 1 (T1), after the last treatment on day 10 (T2), and at 30- day follow-up (T3). A subset of 21 patients was additionally evaluated pre- and posttreatment (T0, T2) by transcranial magnetic stimulation measures of the primary motor cortex excitability (resting and active motor thresholds, MEP amplitude). Results: The ANCOVA, controlling for baseline status (T0), showed a stastistically significant Time x Group interaction for mJTt due to a statistically significant change over time in the active tDCS group compared to the sham tDCS group..