The role of multimodal neuromonitoring during anesthesia for ablation of giant endocranial tumors

Catedra de anesteziologie și reanimatologie nr.2, Catedra de anesteziologie și reanimatologie nr.1 „Valeriu Ghereg”, Catedra de neurochirurgie, USMF „Nicolae Testemițanu”, Chișinău, Republica Moldova, Conferința stiințifică „Nicolae Anestiadi – nume etern al chirurgiei basarabene” consacrată centenarului de la nașterea profesorului Nicolae Anestiadi 26 august 2016Material şi metode. În studiu au fost incluse 2 loturi de pacienţi: I lot– 6 pacienţi cărora li s-a administrat anestezie combinată (i/v + pivot inhalator cu sevofluran); lotul II– 5 pacienţi cărora li s-a administrat anestezie totală intravenoasă (propofol+fentanil). Monitoring: TAs, TAd, TAm (invaziv), PVC, echilibru acidobazic, gazos (arteră şi venă periferică, bulbul jugular), electrolitic, acidul lactic, diurezei orară, PESS. Discuţii. În lotul pacienţilor cu anestezie inhalatorie s-a determinat o incidenţă înaltă a depresiei hemodinamice profunde (Tam - 74,3 mmHg, p= 0,02). Tot aici s-a determinat: utilizarea dozelor mai mici de analgetice şi miorelaxante (sol. atracurium bromid 0,35-0,4mg/kg) , trezire mai rapidă, incidenţă mai scăzută a greții şi tremorului postoperator. S-a reuşit efectuarea mai veridică a neuromonitorigului, datorită cantităţii mai mici de miorelaxante utilizate. La pacienţii cu anestezie intravenoasă s-a determinat o stabilitate hemodinamică (Tam - 82,7 mmHg, p ≤ 0,05), hemoragie intraoperatorie nesemnificativă. În lotul dat s-a reuşit efectuarea neuromonitorigului, cu doze obişnuite de miorelaxante (sol. atracurium bromid 0,5 mg/kg). Concluzii. Tehnicile descrise pot fi utilizate pentru neuromonitorizare multimodală în ablaţia de tumori endocraniene. Tehnica de anestezie inhalatorie, respectând farmacocinetica preparatelor, ar putea fi de preferat, din cauza evitării riscurilor de supra - sau sub dozare de medicamente anestezice, oferind o trezire mai rapidă, cu o evaluarea neurologică imediată, care este extrem de importantă.Materials and methods. The study included two groups of patients: I-st group - 6 patients receiving combined anesthesia (i / v + inhaled sevoflurane); II-nd group - 5 patients who received intravenous anesthesia (propofol + fentanyl).Monitoring: sBP, dBP, mBP (invasive), CVP, acid-base, gas (peripheral artery and vein, jugular bulb) and electrolytic balances, lactic acid, hourly diuresis, neurology evoked potentials. Discussion. In the group of patients with inhalation anesthesia was determined a higher incidence of hemodynamic depression (Tam - 74,3 mmHg, p= 0,02). Also it was determined: use of lower doses of analgetics and muscle relaxants (sol. atracurium bromid 0,35-0,4mg/kg), faster awakening, lower incidence of postoperative nausea and tremors. We managed a more accurate recording of evoked potentials due to the small amount of muscle relaxant used. In patients with intravenous anesthesia was determined a more stable BP (mBP - 82,7 mmHg, p ≤ 0,05), less intraoperative bleeding. In the group given was carrying neuromonitorigului managed with dose of muscle relaxant common (ground. atracurium aromide 0.5 mg / kg). Conclusions. The techniques described can be used for multimodal neuromonitoring in ablation of tumor endocranial. Inhalational anesthesia technique, respecting the pharmacokinetics preparations could be preferable because avoid the risks of over - or under dosage of anesthetic agents, providing an awakening faster with immediate neurological evaluation, which is extremely important

Resonant, broadband and highly efficient optical frequency conversion in semiconductor nanowire gratings at visible and UV wavelengths

Using a hydrodynamic approach we examine bulk- and surface-induced second and third harmonic generation from semiconductor nanowire gratings having a resonant nonlinearity in the absorption region. We demonstrate resonant, broadband and highly efficient optical frequency conversion: contrary to conventional wisdom, we show that harmonic generation can take full advantage of resonant nonlinearities in a spectral range where nonlinear optical coefficients are boosted well beyond what is achievable in the transparent, long-wavelength, non-resonant regime. Using femtosecond pulses with approximately 500 MW/cm2 peak power density, we predict third harmonic conversion efficiencies of approximately 1% in a silicon nanowire array, at nearly any desired UV or visible wavelength, including the range of negative dielectric constant. We also predict surface second harmonic conversion efficiencies of order 0.01%, depending on the electronic effective mass, bistable behavior of the signals as a result of a reshaped resonance, and the onset fifth order nonlinear effects. These remarkable findings, arising from the combined effects of nonlinear resonance dispersion, field localization, and phase-locking, could significantly extend the operational spectral bandwidth of silicon photonics, and strongly suggest that neither linear absorption nor skin depth should be motivating factors to exclude either semiconductors or metals from the list of useful or practical nonlinear materials in any spectral range.Comment: 12 pages, 4 figure

Nonspreading Light Pulses in Photonic Crystals

We investigate propagation of light pulses in photonic crystals in the vicinity of the zero-diffraction point. We show that Gaussian pulses due to nonzero width of their spectrum spread weakly in space and time during the propagation. We also find the family of nonspreading pulses, propagating invariantly in the vicinity of the zero diffraction point of photonic crystals

Studii asupra germinaţiei seminţelor şi răsăririi plantelor de revent (Rheum Rhabarbarum L.)

Seed germination and plantlets spring at rhubarb species were studied in the standard conditions on a peat substrate. Results revealed that the germination rate was of 90%, and spring rate was of 82%. Germination period had 12 days, starting in the 7-th day of experiment, and the spring was done in 10 day

Amicable pairs and aliquot cycles for elliptic curves

An amicable pair for an elliptic curve E/Q is a pair of primes (p,q) of good reduction for E satisfying #E(F_p) = q and #E(F_q) = p. In this paper we study elliptic amicable pairs and analogously defined longer elliptic aliquot cycles. We show that there exist elliptic curves with arbitrarily long aliqout cycles, but that CM elliptic curves (with j not 0) have no aliqout cycles of length greater than two. We give conjectural formulas for the frequency of amicable pairs. For CM curves, the derivation of precise conjectural formulas involves a detailed analysis of the values of the Grossencharacter evaluated at a prime ideal P in End(E) having the property that #E(F_P) is prime. This is especially intricate for the family of curves with j = 0.Comment: 53 page

Photonic crystal spatial filtering in broad aperture diode laser

Broad aperture semiconductor lasers usually suffer from low spatial quality of the emitted beams. Due to the highly compact character of such lasers, the use of conventional intracavity spatial filters is problematic. We demonstrate that extremely compact photonic crystal spatial filters, incorporated into a laser resonator, can improve the beam spatial quality and, correspondingly, increase the brightness of the emitted radiation. We report the decrease in the M2 value from 47 down to 28 due to photonic crystal spatial intracavity filtering and the increase in the brightness by a factor of 1.5, giving a proof of principle of intracavity photonic crystal spatial filtering in broad area semiconductor lasers.Peer ReviewedPostprint (published version

Reevaluation of radiation reaction and consequences for light-matter interactions at the nanoscale

In the context of electromagnetism and nonlinear optical interactions damping is generally introduced as a phenomenological, viscous term that dissipates energy, proportional to the temporal derivative of the polarization. Here, we follow the radiation reaction method presented in [G. W. Ford and R. F. O'Connell, Phys. Lett. A, 157, 217 (1991)], which applies to non-relativistic electrons of finite size, to introduce an explicit reaction force in the Newtonian equation of motion, and derive a hydrodynamic equation that offers new insight on the influence of damping in generic plasmas, metal-based and/or dielectric structures. In these settings, we find new damping-dependent linear and nonlinear source terms that suggest the damping coefficient is proportional to the local charge density, and nonlocal contributions that stem from the spatial derivative of the magnetic field and discuss the conditions that could modify both linear and nonlinear electromagnetic responses.Comment: 11 pages, 1 figure, 19 reference