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Introduction and hypothesis: Various surgical techniques have been described for vaginal vault prolapse repair, but the best surgical approach is still to be proven. The aim of this study is to report the long-term objective and subjective outcomes of women who underwent iliococcygeus fixation for the treatment of vaginal vault prolapse with a minimum follow-up of 10 years. Methods: Women with symptomatic vaginal vault prolapse (Pelvic Organ Prolapse Quantification [POP-Q] stage ≥ 2) who had previously undergone hysterectomy for any reason were prospectively enrolled and treated with iliococcygeus fixation. Subjective success was defined as Patient Global Impression of Improvement (PGI-I) ≤ 2 and an absence of bulging symptoms. Objective success was defined as stage of prolapse < 2 in all compartments. Overall success rate was defined as women without prolapse symptoms, PGI-I ≤ 2, stage of prolapse < 2, and no need for other surgery. Prolpase Quality of Life (P-QOL) questionnaires were completed at the preoperative visit and at every follow-up visit. Multiple logistic regression was performed to identify factors involved in the risk of recurrent POP. Results: After a median (range) follow-up of 120 (120–132) months, the subjective, objective, and overall cure rates were 82% (32/39), 74.4% (29/39), and 74.4% (29/39), respectively. Only stage IV vault descensus independently predicted POP recurrence after ICG (OR: 7.66 [95% CI: 1.21–9.02]; p < 0.001). Conclusion: Iliococcygeus fixation seems to be a safe and effective option for the treatment of vaginal vault prolapse at 10 years' follow-up. © 2020, The International Urogynecological Association.

The properties of Zinc-doped GaAs, grown by MOVPE employing the tertiary buthyl arsine precursor, were studied as a function of the doping level, comprised within the (1 × 1016 – 7 × 1019 cm–3) range. Hall effect measurements were performed as a function of temperature; the simultaneous analysis of the Hall hole density and Hall mobility gave the effective doping concentration, the thermal ionisation energy of the acceptor impurities and the compensation ratio. Fast Fourier Transform Photoluminescence measurements were performed on the GaAs layers; the results were correlated with those obtained from the electrical analysis. A comparison of the obtained data with the results of an analogous investigation, previously performed on intrinsically Carbon doped GaAs layers, allowed the following conclusions: a) the GaAs layers exhibit a low content of non-intentional impurities (

The metal–insulator (MI) transition induced by a magnetic field was evidenced for the first time in compensated n-type GaSb layers grown by molecular beam epitaxy. The free electron densities were in the low 1016 cm−3 range or even slightly lower, so that the zero-field 3D electron gas was degenerate and, at the BMI magnetic field of the MI transition, it populates only the spin-split 0(+) Landau level (extreme quantum limit). On the metallic side of the MI transition a T1/3 dependence of the conductivity was assumed to fit the low-T data and to estimate the BMI value, which resulted of 9.1 T in the purest sample. The MI transition manifests in a strong increase of the diagonal resistivity with the magnetic field, but not of the Hall coefficient, suggesting that the apparent electron density is practically constant, whereas the mobility varies strongly. The evidence of a maximum in the temperature dependence of the Hall coefficient has been explained through a two channels transport mechanism involving localized and extended states.

Magnetoquantum oscillations of the Hall coefficient RH were observed in Te-doped GaSb layers grown by molecular beam epitaxy. The free electron densities were in the low 1016 cm−3 range or even slightly lower, thus achieving, for the first time in GaSb, the extreme quantum limit, where all the electrons occupy the spin-split 0(+) Landau level (LL). Similarly to other known cases, the amplitude of the last maximum of RH could be explained as enhanced by the metal-to-insulator transition of the spin-down electron system in the n=0 LL. The occurrence of the last negative oscillation of RH below its classical value, called Hall dip, could be frustrated, in samples with sufficiently low carrier densities, by an incipient carrier freeze-out at donor impurities induced by the magnetic field.

In AlxGa1-xSb, the Te impurity originates a simple donor state (D level), whose occupancy equilibrates rapidly with the conduction band; it coexists with a DX state which is responsible for the persistent photoconductivity effect. The D level is linked to the L conduction band minima and becomes resonant with the conduction band for x

Results are reported regarding in-plane electrical transport in n-type selectively doped GaSb/AlGaSb multiquantum wells. In the samples, which were grown by molecular beam epitaxy, only the central regions of the Al0.40Ga0.60Sb barriers were Te doped. Low-field, low-temperature Hall measurements in the dark demonstrated the presence in the GaSb wells of a degenerate electron gas with nonzero occupancy only for the lowest miniband. A positive persistent photoconductivity effect, related to the DX character of the Te impurity, was also observed. This behavior enabled the μ electron mobility to be measured at T=10 K as a function of the nS sheet carrier density. Since the experimental data were consistent with a dominant role of the interface roughness scattering in the limiting of μ, the height, Δ, and the lateral size, Λ, of the interface roughness were determined from the analysis of the μ=μ(nS) dependence. Acceptable values of Δ were obtained, consistent with results of structural investigations in singl...

Hall effect measurements were performed in Te-doped AlxGa1−xSb layers grown by molecular beam epitaxy to investigate the composition dependence of the DX center occupancy level. The investigated samples have AlSb molar fractions in the 0.25⩽x⩽0.50 range and n-type doping of about 1018 cm−3. A family of x≈0.40 samples of different doping (5×1015–1018 cm−3) were also studied. The Hall electron density data versus temperature were analyzed at high temperatures (T⩾150 K) where the DX center is at equilibrium, by assuming the negative-U model for the DX level and by taking into account the multivalley conduction effects. The DX level, degenerate in energy with the conduction band at low x values, enters the forbidden gap at x≈0.25 and then it becomes deeper with increasing x. In lightly doped samples, the introduction of a second level of the same Te impurity is required to fit the data; such level can be identified with the nonmetastable level which controls the low temperature electrical properties of the ma...

Hole capture at DX centers is evidenced in Schottky diodes made on Te-doped AlGaSb under forward bias conditions. Capacitance versus voltage measurements performed at low temperatures show that the occupancy of the DX centers is affected by sufficiently large forward biases. The current densities required to achieve such modifications are at least one order of magnitude smaller than those needed in Si-doped AlGaAs. Positive deep level transient spectroscopy signals are systematically detected in all the samples studied when forward-bias filling pulses are used. These observations are discussed in terms of minority carrier (hole) injection and subsequent capture by the DX centers.

We show in this work that, although designing Al/sub x/Ga/sub 1-x/As/GaAs HFET's for microwave power applications requires a large barrier layer bandgap (hence x>0.2), the presence of a large concentration of electrically active DX centers in the barrier layer does not hinder the device reliability. The existence of a remarkable quantity of DX centers in the Al/sub 0.25/Ga/sub 0.75/As barrier layer is for the first time revealed by means of room temperature electroluminescence, and their concentration is evaluated by measuring the threshold voltage shift induced by hot electron stress at cryogenic temperatures.

The optical absorption of molecular-beam-epitaxy-grown and Te-doped GaSb layers is measured in the spectral region of the fundamental absorption over a temperature range extending from 10 K to 300 K. In accordance with the Burstein-Moss description, a filling of the conduction-band states, resulting in a change of the shape and a shift of the absorption edge to higher energies, is observed in the absorption spectra of Te-doped n-type GaSb layers, with electron density ranging from 1.1 × 10 16 to 7.6 × 10 17 cm −3 at room temperature. A quantitative description of the Burstein-Moss effect is performed and the Fermi-level energy and the electron density in thevalley are obtained as a function of the temperature in two different ways: (i) by comparing absorption spectra of heavily doped and unintentionally or lightly doped GaSb samples; (ii) through a direct fit of absorption data performed in the framework of Kane's band model. The values of the Fermi level and of electron density in thevalley which have been optically obtained resulted in satisfactory agreement with those obtained from electrical measurements. The bandgap narrowing and the perturbation of the conduction-band density of states due to heavy doping in small-effective-mass semiconductors, such as GaSb, is considered in the framework of some current theoretical models.

Schottky barriers have been prepared on molecular beam epitaxy (MBE)-grown n-type GaSb by depositing Al in situ. In order to prevent both Sb evaporation at high temperatures and Sb condensation during cooling of the epilayers before the metal deposition, the Sb shutter has been closed at a properly chosen temperature. It is shown that the time, Ar, spent at this temperature with the Sb shutter closed strongly affects both the I-V and C-V characteristics of the barriers. The barrier height values determined by I-V measurements are unreliable due to the non-ideal features of the diodes and to hole injection which is pointed out by deep level transient spectroscopy (DLTS) measurements. Conventional C-V measurements give surprisingly large values of the diffusion potentials and of the donor concentration. These values can be corrected by combining a modified dual-frequency technique with an excess capacitance correction. It is shown that, consistent with the I-V investigation, increased Δ t values result in a significant worsening of the barrier quality.

Electron mobility and low-field transverse physical magnetoresistance were measured in Te-doped GaSb layers grown by molecular beam epitaxy. The samples investigated had electron densities ranging from to ; measurements were taken in the 8 - 300 K temperature range. The high mobility values demonstrate that SnTe can be used as a source of Te doping with results comparable with GaTe. A detailed analysis of the magnetoresistance data demonstrates that in samples with high electron density the magnetoresistance is mainly due to mixed conduction of electrons in both and L conduction band minima: the analysis gives the temperature dependence of the and mobilities and of the energy separation between L and edges. is 82 meV at 300 K and 67 meV at 8 K and exhibits a non-monotonic behaviour within the temperature range explored. In samples with low electron density the magnetoresistance is mainly due to the energy distribution of carriers in the valley.

We have previously shown that the oncogene product p21 Ras is essential for the survival and neurite outgrowth-promoting activity of nerve growth factor on cultured chick embryonic sensory, but not sympathetic neurons. In order to extend our observations to the human system and to non-neuronal cells, we introduced the oncogenic form of p21 Ras into the cytoplasm of three different types of cultured human embryonic neural crest derivatives (8th-11th gestational week): dorsal root ganglion neurons, sympathetic neurons, and adrenal chromaffin cells. These cells are dependent on nerve growth factor for survival and/or fibre outgrowth in vitro. In dorsal root ganglion neurons, p21 Ras promoted survival and fibre outgrowth which was quantitatively and qualitatively comparable to the nerve growth factor effect (84% vs. 95%, control 18%). Sympathetic neurons showed a similar effect, albeit with a higher background survival (91% vs. 93%, control 58%). On chromaffin cells, which respond to nerve growth factor with pronounced fibre outgrowth in culture, the effect of p21 Ras was again comparable to that of nerve growth factor (35% vs. 30%, control 5%). The survival and fibre outgrowth-promoting effects of p21 Ras on human embryonic dorsal root ganglion neurons, sympathetic neurons and chromaffin cells suggest an involvement of p21 Ras in the intracellular signal transduction of nerve growth factor in human neural crest-derived cell populations.

The coexistence of the DX center with nonmetastable bound states of the ordinary substitutional configuration of the donor impurity is extensively investigated in Si-doped ${\mathrm{Al}}_{\mathit{x}}$${\mathrm{Ga}}_{1\mathrm{\ensuremath{-}}\mathit{x}}$As samples having different x AlAs molar fractions in the direct gap region. The occupation of nonmetastable states is evidenced by comparing the ${\mathit{n}}_{\mathit{CV}}$ ``electron density,'' as derived from capacitance-voltage measurements in Schottky diodes, with the ${\mathit{n}}_{\mathit{H}}$ Hall density. In samples of compositions not far from the direct-to-indirect gap transition and with doping levels in the ${10}^{18}$-${\mathrm{cm}}^{\mathrm{\ensuremath{-}}3}$ range, a nonmetastable state SX, degenerate in energy with the conduction band, can reach a significant occupancy when the saturated persistent photoconductivity condition is approached during low-temperature photoionization of DX centers. On the other hand, when the free-electron density is smaller than a critical density of a few ${10}^{16}$ ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}3}$, electrons freeze out into a localized S\ensuremath{\Gamma} state, or into a low mobility impurity band, linked to the \ensuremath{\Gamma} conduction-band edge. A finite occupancy of the SX or S\ensuremath{\Gamma} state gives rise to a significant ${\mathit{N}}_{{\mathit{D}}^{0}}$ density of substitutional donors in the neutral ${\mathit{D}}^{0}$ charge state having a strongly correlated spatial distribution. Electron capture into donor states, DX or not, has a spatially selective character, as can be evidenced by low-temperature mobility data under conditions where impurity scattering dominates. For DX centers, this is demonstrated by the hysteretic behavior of low temperature (${\mathit{T}}_{0}$) ${\mathrm{\ensuremath{\mu}}}_{\mathit{H}}$ vs ${\mathit{n}}_{\mathit{H}}$ data, where any given ${\mathit{n}}_{\mathit{H}}$ value is reached through DX center photoionization steps or through electron capture via a proper thermal cycling. When ${\mathit{N}}_{{\mathit{D}}^{0}}$ is negligible the hysteresis amplitude is maximum. However, whenever ${\mathit{N}}_{{\mathit{D}}^{0}}$ reaches significant values, either at the ${\mathit{T}}_{0}$ temperature or during the thermal cycle, the hysteresis amplitude vanishes. This is systematically observed in all the cases where the occupation of SX or S\ensuremath{\Gamma} states is independently demonstrated through the analysis of ${\mathit{n}}_{\mathit{CV}}$ and ${\mathit{n}}_{\mathit{H}}$ data. Two diverse complementary effects are proposed to explain the observed vanishing of the hysteresis amplitude. \textcopyright{} 1996 The American Physical Society.

Admittance spectroscopy was employed to investigate the electrical properties of buried GaSb homojunctions. A strong p-type surface layer was obtained in n-type GaSb bulk crystals through diffusion of Zn atoms. The acceptor impurities were introduced into Te-doped substrates by epitaxially growing a heavily p(Zn)-doped GaAs layer. Current-voltage investigation, after the removal of the GaAs cap layer, demonstrated the formation of the GaSb p-n homojunction. However, the p-n interface of the junctions resulted to be not due to the presence of Zn. In fact, secondary ion mass spectrometry pointed out only a small penetration depth of Zn atoms in the GaSb substrate (similar to 100 nm), whereas electron beam induced current investigation demonstrated that the p-n junction interface was located more deeply into the substrate (similar to 1 mu m). Admittance spectroscopy and capacitance-voltage investigations led to attribute the change of conduction type from n to p of GaSb beyond the Zn penetration depth to the formation of lattice acceptor defects, influenced by the thermal annealing processes during and after the GaAs growth. An attempt to explain the formation of the buried junction in terms of atomic inter-diffusion is provided, in order to justify, from a microscopic point of view, the low diffusivity of Zn in GaSb, and the depth of the p-n junction interface in the substrate. (C) 2013 AIP Publishing LLC.

The fundamental absorption of GaSb, experimentally investigated by optical transmission measurements performed in the temperature range 9--300 K on nominally undoped molecular-beam-epitaxy-grown GaSb layers, is compared to theory. Calculations related to a band-to-band optical transition theory based on the models of Kane and Elliott, considering the band nonparabolicity and the electron-hole (exciton) interaction effects, respectively, show excellent agreement with experimental results. The role of different contributions to absorption coefficient is discussed.

In this work bulk sulphur-doped (ND>1017 cm-3) GaSb crystals have been investigated by performing Hall and photo-Hall measurements at different intensities of subgap illumination in the temperature range 14-300 K. At low temperature (T

We report the isolation and characterization of novel expressed sequences from the spinal muscular atrophy (SMA) region on human chromosome 5q13. Based on the sequence homology studies these cDNAs were grouped in four classes, one of which shows extensive homologies with the β-glucuronidase (BG) gene, differing in exon arrangement. The other cDNAs do not show any strong homology with known DNA sequences.

This chapter summarises the results achieved by the ArtDeco project and presents the overall approach for developing the models that the large-scale middleware infrastructure designed during the project uses to drive the behaviours of the information systems of a sample networked enterprise operating in the domain of wine production. This domain is sufficiently wide to cover many business aspects that highlight the ability of the proposed infrastructure to adapt its behavior to the evolving execution context by reacting to unexpected events with a very limited human intervention. The same approach has been experimented also in different domains, including fashion industry and value added services for TLC providers.

Buried GaSb junctions were realized through Zn diffusion in Te-doped GaSb bulk crystals, the p-dopant being supplied through the epitaxial deposition of a heavily Zn-doped GaAs layer on GaSb. Structural and electrical investigations confirm the build-up of buried junctions, induced by Zn diffusion within GaSb, with satisfying rectifying properties. Surprisingly, the p-n junctions are formed more deeply with respect to the Zn diffusion front. A local rising up of the native acceptor density is assumed to drive the p-type conductivity conversion of the GaSb substrate beyond the Zn penetration depth.

This chapter overviews the process of collection and automatic analysis of data and documents both inside and outside the Networked Enterprise. We will address the following research problems: discovery of the useful information sources, in terms of the enterprise documentation, of structured and unstructured data provided by existing information systems, of web-available knowledge, of event flow within the business processes; extraction of synthetic knowledge from these information sources, possibly in terms of a common, semantic data model; automatic interpretation and integration of the acquired information; analysis and dissemination of such knowledge to all decisional levels, appropriately adapting it to the user’s function and context.

The molecular beam epitaxy and the characterization of high-quality, non-intentionally doped and Te-doped GaSb are reported. The undoped layers have 77 K Hall hole concentrations p = 1−3 × 10 15 cm −3 and mobilities μ = 3000−5600 cm 2 V −1 s −1 , which compare favourably with the best results reported so far. Photoluminescence (PL) measurements at 70 K point to a relatively low concentration of intrinsic GaSb antisite defects, responsible for the p-type behaviour. A simultaneous fit of μ and p was performed in the 40–300 K temperature range by using a model with two acceptors, one of them having two charge states; the levels have energies consistent with those deduced by PL experiments. n-Doping was obtained approximately in the range 1 × 10 16 −1 × 10 18 cm −3 by using Te from an SnTe source. The mobility values are definitely higher than those reported in the literature and obtained with the same source, and they slightly exceed those achieved in GaSb doped using a GaTe Te source. A procedure for the analysis of electrical data has been set up and tested for n-GaSb with free carrier concentrations lower than a few 1017 cm−3.

The coexistence of the DX center with other donor-related bound states has been investigated in Si-doped direct gap AI,Ga I _ xAs, by comparing electron density data obtained by capacitance/voltage and Hall measurements. These experiments were carried out under saturated persistent photoconductivity conditions, as well as during isothermal capture transients. A D ° bound state degenerate in energy with the conduction band is populated through low temperature photo-ionization of the DX center. The D ° level comes very close in energy to the F minimum when the direct-to-indirect gap transition is approached. Under defined conditions, the final stage of isothermal capture transients is dominated by the electron freezing into hydrogenic bound states linked to F.

It is shown that current instabilities, which are frequently observed at low temperatures in forward biased Schottky barriers on n‐type AlGaAs, result from changes in the distribution of negatively charged donors (DX centers) near the metal contact. These changes cannot be ascribed to sample‐heating effects, but they originate from hole injection in the barrier during forward biasing. The dominant mechanisms which are expected to induce the observed distortions in the DX center profile are (i) direct capture of the injected holes by the DX center and (ii) radiative electron‐hole recombination resulting in DX center photoionization. The role of the two mechanisms is discussed.

n H (Hall) and n CV (capacitance-voltage) electron density data are compared in a Si-doped Al 0.35 Ga 0.65 As sample having an N d -N a =2.8×10 18 cm -3 net donor density. Data taken during low-temperature photoionization of DX centers and during temperature variations in the Persistent photoconductivity regime (T

The spatial distribution of the DX charges is more similar to a random one the more the saturated persistent photoconductivity (SPPC) is approached through photoionization steps. Moreover, it is shown that randomly distributed scattering centres act as isolated independent screened centres. These two facts enable a significant comparison between calculated and experimental mu = mu (n) dependences as the SPPC is approached. In Si-doped AlxGa1-xAs (x=0.25) samples the negative-U model, involving a negative DX- charge state with two electrons captured by the centre, is better supported by the comparison. As discussed, x approximately=0.25 samples with doping levels in the 1018 cm-3 range offer a practically unique opportunity for a significant analysis of low-temperature mobility data.

The low-temperature electron mobility mu in Si-doped AlxGa1-xAs (x=0.25) is not a single-valued function of the free electron density n, mu being larger if a given n value is reached through capture rather than photoionization processes. This difference is reduced by lowering the Si doping level. The result is interpreted as due to spatial correlations amongst charges at the DX centres. Analysis of mobility transients during isothermal capture processes in the temperature range 110-140 K indicates that the fast initial stage of the capture is marked by an increasing order in the spatial distribution of the scattering centres. On the contrary, the slow final stage of the capture process is characterized by a diminishing order in the distribution.

L’examen endoscopique des lesions caustiques permet l’identification rapide et directe des alterations provoquees par le caustique ingere et/ou inhale. De plus, l’examen peut etre repete, chaque etape, en vue de choisir l’approche therapeutique la plus appropriee.

L’examen endoscopique des lesions dues a l’ingestion de caustiques joue non seulement un role diagnostique fondamental mais constitue egalement l’acte therapeutique de premier choix dans les stenoses cicatricielles successives aux lesions caustiques.

Photoelectrical measurements were taken on a nominally undoped-InGaP/GaAs superlattice, inserted between two p+ and n+ InGaP cladding layers. The sequence of InGaP/GaAs alternated layers forming the superlattice was grown lattice matched on n+-GaAs substrates through low pressure-metal organic vapor phase epitaxy, at growth conditions previously optimized for obtaining sharp interfaces and negligible ordering effects in the cation sublattice of the InGaP layers. A peculiar dependence of both the photocurrent and the photovoltaic signals on the modulation frequency of the exciting light beam was observed and then interpreted according to proper equivalent electrical circuits. The effects induced by an incomplete depletion of the nominally undoped superlattice region are analyzed in detail, and the analogies between photoelectrical investigation and admittance spectroscopy are pointed out.

The low-temperature Hall mobility of photoexcited electrons has been measured in Si-doped MBE AlGaAs samples. Different fractions of occupied DX centres were obtained by selecting different free-electron densities: possible systematic errors in Hall measurements due to the method of photoexcitation are demonstrated and critically analysed. Using suitable values for the acceptor density and the alloy scattering potential a fair fitting of the experimental data was achieved within both negative-U and positive-U models for the DX centre. Discrepancies between calculated and experimental mobility versus temperature curves are observed, which are more evident the lower the free-electron densities. They are tentatively explained as being due to electrons in an impurity band originated by the shallow effective-mass state related to the Gamma minimum of the conduction band.

The role of quasistatic C‐V measurements in investigating DX‐center‐related features in AlGaAs (x=0.25, 0.30, and 0.35) Schottky barriers has been reconsidered under different experimental conditions. The vanishing of the electron‐capture rate by the DX center, at low temperature, is responsible for a frozen‐step‐like density profile of positively charged DX centers near the metal‐semiconductor interface. This causes a knee‐shaped 1/C2‐vs‐V plot and gives rise to an apparent built‐in potential. The low‐temperature freezing in of the free‐electron density in the flatband region has been demonstrated through specific experiments of thermally stimulated capacitance and low‐temperature C‐V measurements performed on the sample cooled at different cooling rates.

The photovoltaic spectra of GaAs p-i-n diodes in which the insulating region contained several molecular beam epitaxy quantum wells of nominally undoped GaAs with AlGaAs barriers were studied as a function of temperature in the interval 10–300 K. To understand the effect of the transport mechanism of photoexcited carriers on the photovoltaic response, the temperature dependence of the absorption and photovoltage peaks was measured together with the enhancement of heavy-hole electron (n = 1) exciton resonance over a wide temperature range. The temperature dependence of the lineshapes of photovoltaic and absorption spectra showed comparable thermally activated broadening, and the strength of the absorption signal increased with decreasing temperature, giving a nearly constant integrated area. The intensity of the photovoltaic peaks showed non-monotonic behaviour with a minimum at about 100 K. This was tentatively attributed to the temperature dependence of the dark current-voltage characteristics of the diode and the exciton lifetime.

The low-temperature Hall mobility of photoexcited electrons has been measured in Si-doped MBE AlGaAs samples and compared with calculated data using the background acceptor density and the alloy scattering potential as free parameters. The possibility of discriminating between negative- or positive- U electron correlation energy for the DX centre has been investigated through a careful analysis of mobility versus temperature curves relating to different photoexcited electron densities. A crucial role of the acceptor density to explain the experimental data within the positive- U model has been evidenced.

The significance of both the density N, and the apparent built-in voltage Va, as usually obtained from C-V measurements on Schottky barriers containing DX centers, is clarified. It is also shown that, owing to the non-equilibrium occupancy of the DX center, at low temperature the electron density in the flat-band region depends on the cooling rate of the sample.