29 research outputs found
Three-dimensional analysis of the occlusal plane related to the hamular?incisive?papilla occlusal plane in young adults
Promene mineralnih sastava mandibulnog tela u osteoporozi
The aim of investigation was to determine physical-chemic characteristics of selected segments of mandibular corpuses from 2 cadavers which would be indicators to determine changes of bone compositions due to osteoporosis. 3 samples from massive mandibular body from cadaver where teeth of lower arch persisted and 3 samples from mandibular edentulous corpus from another cadaver were investigated. External borders of samples were assigned. In the same x-ray exposing and in identical processing 2 orthopantomographs were made and optical densities(OPDs) of regions of interest were analyzed using DT II 05 (EU(England,UK)). Samples of similar dimensions were cut and then analyzed by scanning-electronic microscopy (Philips,EU). Using bensol as liquid phase on 200C in pycnometer, densities of samples of bones were analyzed. Values of OPDs, in U/mm2, amount: -2.48-sample(S)l, -2.86 S2, -2.51 S3, -0.90 S4, -1.40 S5, -0.62 S6. Statistically significant, to p lt 0.01 totals of cancellous sites were established in comparisons: of S6 and of S4, of SI and of S5 as well as of S2 and of S4, and to p lt 0.1 were established in comparisons: of Sl and of S3, of SI and of S6, of S2 and of S5, of S2 and of S6, of S3 and of S4, as well as of S6 and of S4. Mean thickness of cortical lamellae, in mm, amount: 17.9 ± 7.51 in S1, 12.22 + 1.17 in S2, 31.03 ± 8.91 in S3, 9.31 ± 3.89 in S4, 23.9 ± 11.7 in S5 and 4.06 ± 1,02 in S6. Densities in g/cm3, amount: 1.9658 for S1, 2.1141 for S2, 2.0748 for S3, 2.1296 for S4 2.2231 for S5 and 2.1357 for S6. Differences of densities and of compositions of non-osteoporotic mandibular-body samples, and of mandibular osteoporotic samples were determined.Osteoporoza jeste značajno i zastupljeno oboljenje kada dominiraju procesi razgrađivanja kostnih supstanci u humanim organizmima. Za razliku od činjenica da u literaturi postoje brojni prikazi – makroskopski patološki preparati, mikroskopski patološki preparati, šematizovane ilustracije itd. skoro da nema podataka ni o promenama fizičkih parametara, niti o uticajima kompleksnih hemijskih jedinjenja u kostnim supstancama izmenjenim usled osteoporoza na fizičko-hemijske osobenosti izmenjene kosti, tako da dosta toga još uvek nije ispitano u vezi karakteristika, izmena sastava i fizičko-hemijske osobenosti osteoporoznih kosti. (Kanis 1994; 1996, WHO 1994 Kršljak 1995, Novaković i Giordani 1996, Poštić, Marković, Veselinović Tijanić i Zec 2001). Svakako bi trebalo da bude interesantno i značajno proceniti šta je izmenjeno u makrostrukturama i šta je sve izmenjeno u mikrostrukturama kosti oštećenih usled osteoporoza. Čini se da je važno utvrditi kako bi trebalo delovati na nivou jedinjenja i potencijalno na nivou molekula. Stoga je potrebno ispitati kako bi, na osnovu izmena u mikrostrukturama kosti, trebalo inicirati pozitivno remodelovanje kostne supstance, da li su formirana jedinjenja kakva je potrebno razgraditi zato što su apsolutno nepovoljna ili je moguće delovati, bez obzira na formirana odnosno preformirana jedinjenja, apozicijama potrebnih i u smislu osteogenih potencijala kvalitetnih jedinjenja na nivoima mikrostruktura. Ispitivanjima fizičko-hemijskih promena mikrostruktura kosti trebalo bi da budu utvrđeni karakteristični podaci, tako da bi na osnovu karakterističnih podataka trebalo proceniti da li bi aplikovanjima posebno sintetisanih jedinjenja odnosno specifičnih supstanci i aplikovanjima posebno kombinovanih supstanci bilo moguće poboljšati strukture kosti, ojačati segmente kosti - poboljšati fizičko-hemijska svojstva i sprečiti frakture segmenata kosti
Promene mineralnih sastava mandibulnog tela u osteoporozi
The aim of investigation was to determine physical-chemic characteristics of selected segments of mandibular corpuses from 2 cadavers which would be indicators to determine changes of bone compositions due to osteoporosis. 3 samples from massive mandibular body from cadaver where teeth of lower arch persisted and 3 samples from mandibular edentulous corpus from another cadaver were investigated. External borders of samples were assigned. In the same x-ray exposing and in identical processing 2 orthopantomographs were made and optical densities(OPDs) of regions of interest were analyzed using DT II 05 (EU(England,UK)). Samples of similar dimensions were cut and then analyzed by scanning-electronic microscopy (Philips,EU). Using bensol as liquid phase on 200C in pycnometer, densities of samples of bones were analyzed. Values of OPDs, in U/mm2, amount: -2.48-sample(S)l, -2.86 S2, -2.51 S3, -0.90 S4, -1.40 S5, -0.62 S6. Statistically significant, to p lt 0.01 totals of cancellous sites were established in comparisons: of S6 and of S4, of SI and of S5 as well as of S2 and of S4, and to p lt 0.1 were established in comparisons: of Sl and of S3, of SI and of S6, of S2 and of S5, of S2 and of S6, of S3 and of S4, as well as of S6 and of S4. Mean thickness of cortical lamellae, in mm, amount: 17.9 ± 7.51 in S1, 12.22 + 1.17 in S2, 31.03 ± 8.91 in S3, 9.31 ± 3.89 in S4, 23.9 ± 11.7 in S5 and 4.06 ± 1,02 in S6. Densities in g/cm3, amount: 1.9658 for S1, 2.1141 for S2, 2.0748 for S3, 2.1296 for S4 2.2231 for S5 and 2.1357 for S6. Differences of densities and of compositions of non-osteoporotic mandibular-body samples, and of mandibular osteoporotic samples were determined.Osteoporoza jeste značajno i zastupljeno oboljenje kada dominiraju procesi razgrađivanja kostnih supstanci u humanim organizmima. Za razliku od činjenica da u literaturi postoje brojni prikazi – makroskopski patološki preparati, mikroskopski patološki preparati, šematizovane ilustracije itd. skoro da nema podataka ni o promenama fizičkih parametara, niti o uticajima kompleksnih hemijskih jedinjenja u kostnim supstancama izmenjenim usled osteoporoza na fizičko-hemijske osobenosti izmenjene kosti, tako da dosta toga još uvek nije ispitano u vezi karakteristika, izmena sastava i fizičko-hemijske osobenosti osteoporoznih kosti. (Kanis 1994; 1996, WHO 1994 Kršljak 1995, Novaković i Giordani 1996, Poštić, Marković, Veselinović Tijanić i Zec 2001). Svakako bi trebalo da bude interesantno i značajno proceniti šta je izmenjeno u makrostrukturama i šta je sve izmenjeno u mikrostrukturama kosti oštećenih usled osteoporoza. Čini se da je važno utvrditi kako bi trebalo delovati na nivou jedinjenja i potencijalno na nivou molekula. Stoga je potrebno ispitati kako bi, na osnovu izmena u mikrostrukturama kosti, trebalo inicirati pozitivno remodelovanje kostne supstance, da li su formirana jedinjenja kakva je potrebno razgraditi zato što su apsolutno nepovoljna ili je moguće delovati, bez obzira na formirana odnosno preformirana jedinjenja, apozicijama potrebnih i u smislu osteogenih potencijala kvalitetnih jedinjenja na nivoima mikrostruktura. Ispitivanjima fizičko-hemijskih promena mikrostruktura kosti trebalo bi da budu utvrđeni karakteristični podaci, tako da bi na osnovu karakterističnih podataka trebalo proceniti da li bi aplikovanjima posebno sintetisanih jedinjenja odnosno specifičnih supstanci i aplikovanjima posebno kombinovanih supstanci bilo moguće poboljšati strukture kosti, ojačati segmente kosti - poboljšati fizičko-hemijska svojstva i sprečiti frakture segmenata kosti
Toward mid-infrared nonlinear optics applications of silicon carbide microdisks engineered by lateral under-etching [invited]
We report the fabrication and characterization of silicon carbide microdisks on top of silicon pillars suited for applications from near-to mid-infrared. We probe 10 ?m diameter disks with different under-etching depths, from 4 ?m down to 1.4 ?m, fabricated by isotropic plasma etching and extract quality factors up to 8400 at telecom wavelength. Our geometry is suited to present high Q single-mode operation. We experimentally demonstrate high-order whispering-gallery mode suppression while preserving the fundamental gallery mode and investigate some requirements for nonlinear optics applications on this platform, specifically in terms of quality factor and dispersion for Kerr frequency comb generation
Dispersion engineered air-clad SiGe waveguides with low propagation loss in the mid-infrared
Summary form only given. Photonic devices operating in the mid-IR (3 μm to 13μm wavelength range) are of great interest for a wide range of applications, such as free-space communications, environmental monitoring or defence. Group IV-based material platforms [1], such as silicon-on-insulator (SOI)[2] and silicon-on-sapphire (SOS)[3] have attracted significant interest for mid-IR integrated photonics. However, absorption in silica beyond 3.5 μm and in sapphire beyond 5.5 μm eventually limits the operational wavelength band of these platforms. More recently, silicon-germanium (SiGe) alloys, with a transparency window potentially extending up to 13 μm depending on the Ge content [4] have emerged as an attractive alternative platform for mid-IR photonics [5-7]. In [6, 7] we reported Si 0.6 Ge 0.4 waveguides buried-in silicon with propagation loss of around 1dB/cm at 4μm, and nonlinear properties somewhat comparable to crystalline silicon between 3.5μm and 5μm
Mid-infrared nonlinear optics in SiGe waveguides
Comprehensive mid-IR nonlinear measurements of SiGe waveguides performed in the picosecond and femtosecond regime and compared to numerical calculations are reported. Nonlinear properties of SiGe waveguides in the mid-IR are extracted
Mid-infrared ultra-short pulses nonlinear measurement of SiGe waveguides
International audienc
Mid-infrared nonlinear optical response of Si-Ge waveguides with ultra-short optical pulses
We characterize the nonlinear optical response of low loss Si0.6Ge0.4 / Si waveguides in the mid-infrared between 3.3 μm and 4 μm using femtosecond optical pulses. We estimate the three and four-photon absorption coefficients as well as the Kerr nonlinear refractive index from the experimental measurements. The effect of multiphoton absorption on the optical nonlinear Kerr response is evaluated and the nonlinear figure of merit estimated providing some guidelines for designing nonlinear optical devices in the mid-IR. Finally, we compare the impact of free-carrier absorption at mid-infrared wavelengths versus near-infrared wavelengths for these ultra-short pulses
Systematic assessment of the various controversies, difficulties, and current trends in the reestablishment of lost occlusal planes in edentulous patients
Waveguides for nonlinear optics in the mid-infrared
I will review our work on nonlinear waveguides for supercontinuum generation in the mid-infrared focusing on the nonlinear properties and waveguide performance of chalcogenide, silicon and silicon-germanium devices