710 research outputs found
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
Nickel catalyst faceting in plasma-enhanced direct current chemical vapor deposition of carbon nanofibers
8 pagesInternational audienceVertically aligned multi-walled carbon nanofibers (CNFs) were grown by plasma-enhanced chemical vapor deposition with Ni catalysts on the top of nanofibers. Transmission electron microscopy was used to study the morphology and crystallography of Ni catalysts, which are essential for the nucleation and growth of CNFs. A model for the faceted shape of Ni catalytic particles is proposed. It is shown that the exposed polyhedral surfaces of Ni catalytic particles for vertically aligned CNFs are composed of {111}, {110}, and {100}, a faceting that appears to be characteristic of the growth atmosphere
Field Localization and Enhancement of Phase Locked Second and Third Harmonic Generation in Absorbing Semiconductor Cavities
We predict and experimentally observe the enhancement by three orders of
magnitude of phase mismatched second and third harmonic generation in a GaAs
cavity at 650nm and 433nm, respectively, well above the absorption edge. Phase
locking between the pump and the harmonics changes the effective dispersion of
the medium and inhibits absorption. Despite hostile conditions the harmonics
become localized inside the cavity leading to relatively large conversion
efficiencies. Field localization plays a pivotal role and ushers in a new class
of semiconductor-based devices in the visible and UV ranges
The Philia project – for the successful integration of the young through their empowerment and social network development
The Philia+ project has been approved for funding within the Erasmus + Programme. Several partners from Belgium, France, Germany, Portugal and Romania (from higher education and social work institutions) have worked to support the academic success and social inclusion of (pre)adolescents aged 13-18 in foster care, and to enhance, preserve and develop their support networks. Training programmes were held for teachers, trainers and researchers involved in the project, as well as for students and social work professionals and young people in difficulty in the care of associations and organizations providing them social and psychological support. The aim has always been to change their position according to the theoretical DPAPC (empowerment of individuals and communities) framework and to the methodological RAC (collaborative research-action) framework, in order to enable them to understand the mechanism of the social determinism of success and failure and to enhance their support networks. We managed to create two training modules, teasers of experienced testimonies (focus groups, comprehensive conversations), educational films for the two modules, educational films on accompanying Roma and unaccompanied minors.info:eu-repo/semantics/publishedVersio
Etchant-induced shaping of nanoparticle catalysts during chemical vapour growth of carbon nanofibres
10 pagesInternational audienceCarbon nanofibres (CNFs) obtained by plasma enhanced chemical vapour deposition are made of cone-shaped graphene layers, the opening angle of which has a significant influence on their properties: the smaller the angle, the closer the properties to those of carbon nanotubes. That angle is determined by the shape of the metal nanoparticle used to catalyse the growth. We show in this paper that the shape of Ni nanoparticle catalysts, and in turn the CNF properties, can be tuned during plasma-enhanced chemical vapour deposition, by the choice of the etchant gas. We show in particular that a water-containing etchant (H2O or H2O+H2) increases the growth rate by an order of magnitude at 600°C compared to an ammonia-containing etchant (NH3 or NH3+H2), and leaves more elongated Ni particles with a cone angle three times smaller. We conclude that the cone angle and the growth rate are directly related, and propose a mechanism to explain that large difference between the two etchants
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
On the mechanisms of precipitation of graphene on nickel thin films
Growth on transition metal substrates is becoming a method of choice to
prepare large-area graphene foils. In the case of nickel, where carbon has a
significant solubility, such a growth process includes at least two elementary
steps: (1) carbon dissolution into the metal, and (2) graphene precipitation at
the surface. Here, we dissolve calibrated amounts of carbon in nickel films,
using carbon ion implantation, and annealing at 725 \circ or 900 \circ. We then
use transmission electron microscopy to analyse the precipitation process in
detail: the latter appears to imply carbon diffusion over large distances and
at least two distinct microscopic mechanisms
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
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