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The current labor situation, mediated by different and recent social, labor and, in new times, health crises, forces people to be in constant adaptation and professional reinvention, needing learning that allows better self-management and self-regulation of their labor possibilities. Personal and work trajectories are increasingly unstable, discontinuous, intermittent, and people access to a greater extent precarious, insecure jobs with minimal quality conditions and, not infrequently, maladapted to the level of professional qualification that they have. A clear case is that of the group of guidance professionals, a qualified profile and/or in constant training that fulfills an essential social function, especially in complex times like the ones we live in. Specifically, in this work we are interested in validating the functionality of the CCP model in the training of guidance professionals, identifying the most significant qualitative elements that they perceive. A qualitative design is selected into a Delphi study, through the application of an interview protocol with open questions of a narrative nature. The data is analyzed by traditional procedures of qualitative content analysis, with the support of the NVivo computer software in its version 12. The findings found reveal that the CCP model allows the development of career management skills in the process of configuration of professional projects, especially regarding exploratory skills on self-knowledge, decision-making and career project. The functionality of the model is concluded, highlighting its possibilities of self-application through mixed virtual systems with professional accompaniment and resource support. Likewise, it is concluded that the qualitative-narrative methodology allows to obtain meanings and understanding about the scope of the model in the initial and continuous training of guidance professionals. [ABSTRACT FROM AUTHOR]

Background: The present study assessed the quantity and quality of nutritional advice and support given to colorectal cancer survivors in the UK. Methods: A descriptive cross‐sectional survey was completed by 75 colorectal cancer survivors recruited through social media and bowel cancer support groups in the UK. The survey consisted of open‐ended and closed questions that aimed to explore the nutritional needs, nutritional advice given and other sources of information accessed by colorectal cancer survivors. Results: Sixty‐nine percent of respondents reported that they did not receive any nutritional advice or support from their healthcare team throughout diagnosis, treatment and post‐treatment. Colorectal cancer survivors accessed nutritional advice from a variety of sources, mainly cancer charity websites. Respondents expressed their desire for individualised advice relating to their nutritional problems. Conclusions: The results obtained in the present study indicate that a high proportion of colorectal cancer patients are not receiving the nutritional support that they need to overcome nutritional difficulties. There is an urgent need to improve clinical practice to ensure colorectal patients receive nutritional advice that is both consistent between healthcare professionals and personalised throughout each stage of diagnosis, treatment and post‐treatment. [ABSTRACT FROM AUTHOR]

[Display omitted] • The study identifies drivers of digital technology adoption in the agrifood sector. • Cluster analysis and cross-efficiency DEA is used to develop the research model. • A synthetic index is used to rank the companies according to the drivers. • The position in the ranking is determined by the most complex technologies. • The ranking position is related to product, radical and sustainable innovations. Digital transformation affects all stages of the agri-food value chain. Digitalisation is being combined with innovations and eco-innovations to gain a competitive advantage and ensure greater sustained competitiveness. However, not all technologies have been implemented in the same way and at the same pace by the different companies in the agri-food sector. The aim of this research is to identify the internal and external drivers of digitalisation in agri-food companies and to develop a synthetic index to rank companies based on those drivers, before examining the relationship between the position in the ranking and innovation. The results reveal that the decisive drivers are management support and competitive pressure rather than external support from government policies or suppliers. Higher ranking companies in terms of the digitalisation process are more proactive in introducing product and radical innovations and are the most eco-innovative and thus sustainability-oriented. Finally, results show that the digitalisation of the sector is marked by the depth of technology implementation, specifically IoT, big data and artificial intelligence. Blockchain technology does not currently make a difference as it is not widely used. [ABSTRACT FROM AUTHOR]

Background and aims: Despite the high interest in biochar as soil amendment, the number of field studies is still limited, being experiments with perennial crops in arid lands particularly lacking. This study evaluated the application of compost and biochar in a drip-irrigated organic olive crop in a calcareous soil in South-East Spain. Methods: During two consecutive years, changes in soil total organic C (TOC), dissolved organic C (DOC) and water soluble N (WSN), mineral N (NH and NO ), NO emissions, denitrifying enzyme activity (DEA) and number of amoA gen copies were monitored. Results: Biochar increased TOC compared to the rest of treatments, whereas DOC and WSN significantly increased in plots amended with compost and the compost-biochar mixture. DEA, amoA-encoding genes and NO emissions were highest with the compost-biochar mixture, but results were not always significant. Conclusions: Our results show that, in these N-limited and deficit irrigated semi-arid agro-ecosystems, compost amendment has an impact on soil microbiological activity with a link to N availability. Biochar applied alone does not alter the N dynamics, but markedly builds-up soil C. In both cases only during the first year these effects were statistically significant. When applied in combination a synergistic effect was observed and the highest values of DEA, amoA gene copies and NO emissions were detected. [ABSTRACT FROM AUTHOR]

A composting study was performed to assess the impact of biochar addition to a mixture of poultry manure and barley straw. Two treatments: control (78% poultry manure + 22% barley straw, dry weight) and the same mixture amended with biochar (3% dry weight), were composted in duplicated windrows during 19 weeks. Typical monitoring parameters and gaseous emissions (CO 2 , CO, CH 4 , N 2 O and H 2 S) were evaluated during the process as well as the agronomical quality of the end-products. Biochar accelerated organic matter degradation and ammonium formation during the thermophilic phase and enhanced nitrification during the maturation phase. Our results suggest that biochar, as composting additive, improved the physical properties of the mixture by preventing the formation of clumps larger than 70 mm. It favoured microbiological activity without a relevant impact on N losses and gaseous emissions. It was estimated that biochar addition at 3% could reduce the composting time by 20%. [ABSTRACT FROM AUTHOR]

Context: Linezolid resistance is extremely uncommon in Staphylococcus aureus.Objective: To report an outbreak with linezolid and methicillin-resistant S. aureus (LRSA) in an intensive care department and the effective control measures taken.Design, Setting, and Patients: Outbreak study of consecutive critically ill patients colonized and/or infected with LRSA at an intensive care department of a 1000-bed tertiary care university teaching hospital in Madrid, Spain. Patients were placed under strict contact isolation. Daily updates of outbreak data and recommendations for the use of linezolid were issued. Extensive environmental sampling and screening of the hands of health care workers were performed.Main Outcome Measures: Linezolid use and clinical and epidemiological characteristics and outcomes using minimal inhibitory concentrations, pulsed-field gel electrophoresis, and polymerase chain reaction of LRSA isolates.Results: Between April 13 and June 26, 2008, 12 patients with LRSA were identified. In 6 patients, LRSA caused ventilator-associated pneumonia and in 3 patients it caused bacteremia. Isolates were susceptible to trimethoprim-sulfamethoxazole, glycopeptides, tigecycline, and daptomycin. Genotyping identified 1 predominant clone and 3 other types. Cfr-mediated linezolid resistance was demonstrated in all isolates. Potential hospital staff carriers and environmental samples were negative except for one. Six patients died, 5 of them in the intensive care unit, with 1 death attributed to LRSA infection. Linezolid use decreased from 202 defined daily doses in April 2008 to 25 defined daily doses in July 2008. Between July 2008 and April 2010, no new cases have been identified in the weekly surveillance cultures or diagnostic samples.Conclusions: The first clinical outbreak, to our knowledge, with LRSA mediated by the cfr gene developed at our center, was associated with nosocomial transmission and extensive usage of linezolid. Reduction of linezolid use and infection-control measures were associated with the termination of the outbreak. [ABSTRACT FROM AUTHOR]

There is much evidence that demonstrates that programs and interventions based on the theoretical models of the Theory of Reasoned Action (TRA) and the Theory of Planned Behaviour (TPB) have been effective in the prevention of the sexual transmission of HIV. The objective of this work is to compare the effectiveness of both models in the prediction of condom use, distinguishing two components inside the variable Perceived Behavioural Control of the TPB model: self-efficacy and control. The perspective of gender differences is also added. The study was carried out in a sample of 601 Portuguese and Spanish university students. The results show that the females have a higher average in all the TPB variables than males, except in the frequency of condom use: females request the use of condoms less frequently than males. On the other hand, for both females and males the TPB model predicts better condom-use intention than the TRA. However there are no differences between the two models in relation to the prediction of condom-use behaviour. For prediction of intention, the most outstanding variable among females is attitude, while among males they are subjective norm and self-efficacy. Finally, we analyze the implications of these data from a theoretical and practical point of view. [ABSTRACT FROM AUTHOR]

Objectives: The aim of this study was to determine the factors related to the adoption of effective methods for preventing AIDS, particularly condom use, in university students from Spain and Portugal. Study design: A cross-sectionaI, and cross-cultural study. Data were obtained by questionnaire. Method: The variables analysed in the sample of Spanish and Portuguese students were: the perceptions of benefits and barriers to condom use; perceived self-efficacy in the negotiation of condom use; and in using a condom in difficult situations; and the perceptions of vulnerability, severity and risk. Results: The data showed similarities between the Spanish and Portuguese students in the high frequency of condom use and the weight of self-efficacy for negotiating and ensuring condom use. However, data also reflected differences between the countries especially with regard to the weight of benefits and costs in the adoption of prevention methods. Conclusions: These findings suggest that the different realities for each country or context must be considered in the design of AIDS prevention programmes aimed at late adolescents. Whereas in both countries prevention programmes should encourage the ability to negotiate condom use, Portuguese programmes must underline the benefits of condom use, and Spanish programmes should aim to analyse the importance of barriers to condom use for the students to reduce these and to replace costs with benefits. [ABSTRACT FROM AUTHOR]

This work reports on the growth of wurtzite InN nanocolumns on A-plane GaN templates and on their structural and optical characterization by scanning and transmission electron microscopy, photoluminescence, and Raman spectroscopy. InN nanocolumns grown on A-plane substrates show sharp and pyramidal-like top surfaces that could be attributed to A-plane and M-plane facets, instead of the hexagonal top surfaces observed in nanocolumns grown on C-plane surfaces. The results of these characterization techniques show that the nanocolumns preserve the nonpolar growth orientation of the GaN templates. Good crystal quality is expected from the low temperature (13 K) photoluminescence dominant peak at 0.69 eV. [ABSTRACT FROM AUTHOR]

High quality InN nanocolumns have been grown by molecular beam epitaxy on bare and AlN-buffered Si(111) substrates. The accommodation mechanism of the InN nanocolumns to the substrate was studied by transmission electron microscopy. Samples grown on AlN-buffered Si(111) show abrupt interfaces between the nanocolumns and the buffer layer, where an array of periodically spaced misfit dislocations develops. Samples grown on bare Si(111) exhibit a thin SixNy at the InN nanocolumn/substrate interface because of Si nitridation. The SixNy thickness and roughness may affect the nanocolumn relative alignment to the substrate. In all cases, InN nanocolumns grow strain- and defect-free. [ABSTRACT FROM AUTHOR]

• Organic fertilization resulted in higher N 2 O emissions than mineral fertilization. • Biochar improved yield-scaled N 2 O emissions in all treatments. • The combination of biochar and mineral fertilization led to the lowest yield-scaled N 2 O emissions. The impact of different forms of nitrogen input, biochar amendments and their combination on the yield-scaled N 2 O emissions were investigated during the cultivation of a representative commercial crop. A field randomized block design with inorganic/organic fertilization and biochar amendment was established during a crop cycle of drip-irrigated broccoli. N 2 O emissions were measured with a static chamber in crop rows and in the bare soil control. N 2 O emissions were triggered by N fertigation and heavy rainfall events and increased as the plants grew. Organic fertilization resulted in higher N 2 O emissions than mineral fertilization and these treatments also resulted in the highest peak emissions after fertigation events. Biochar had a significant mitigation effect in hot moments registered immediately after fertilization in organic fertilization treatments. However, biochar caused a slight but not significant reduction in cumulative N 2 O emissions in all treatments. Peak emissions after heavy rainfall were similar in all the treatments and were not affected by the biochar amendment. Biochar usage decreased the soil bulk density in the inorganic fertilization treatments and facilitated N uptake by the plants. Biochar addition resulted in a significant reduction in yield-scaled emissions, which was more pronounced in the inorganic fertilizer treatments. [ABSTRACT FROM AUTHOR]

• Biochar reduced VOC concentration during the thermophilic phase of composting. • 50% of the nitrogen and oxygenated VOC were significantly reduced by biochar addition. • The improved aerated conditions in the pile enhanced the VOC removal efficiency. The efficiency of biochar for reducing the levels of volatile organic compounds (VOC) was investigated in a composting mixture containing 90% poultry manure and 10% straw (with and without 3% biochar addition) at three different stages of the process. The use of a low application rate of biochar reduced the concentration of VOC during the thermophilic phase. Biochar significantly reduced the levels of nitrogen volatile compounds, which are the most abundant VOC family, originated from microbial transformation of the N-compounds originally present in manure. The most efficient VOC reduction was observed in oxygenated volatile compounds (ketones, phenols and organic acids), which are intermediates of organic matter degradation, whereas there was no effect on other VOC families (aliphatic, aromatic and terpenes). These results suggest the importance of not only the sorption capacity of biochar but also its impact in the composting progress as main drivers for VOC reduction. [ABSTRACT FROM AUTHOR]

A correction to the article "InN nanocolumns grown by plasma-assisted molecular beam epitaxy on A-plane GaN templates" that was published in the 2009 issue is presented.

Abstract: Atriplex halimus L. (Amaranthaceae) (Mediterranean saltbush) is a halophytic shrub that is widely distributed in arid and semi-arid regions around the Mediterranean basin and east to Saudi Arabia, at elevations less than 900 m. It grows on a variety of soils, from fine to coarse texture, with varying degrees of salinity. There are two sub-species of A. halimus: halimus is diploid (2n = 2x = 18) and is found at semi-arid, less-saline sites, while schweinfurthii is tetraploid (2n = 4x = 36) and occupies arid, saline sites. Throughout its distribution, A. halimus is exposed to high light intensity and temperature and varying degrees of drought and salinity; it can also withstand sub-zero winter temperatures or soil contamination by trace elements. Some of its physiological and biochemical tolerance mechanisms – such as adjustment of plant water relations – are common to all or several of these environmental stresses, but others are specific to particular stresses. The importance of A. halimus in the functioning of ecosystems is reflected in its promotion of soil biota, while it also acts as a food plant for mammals and arthropods. Its deep root system decreases soil erosion in arid zones, due to stabilisation of the soil. The protein-rich shoot material of A. halimus makes it an important fodder species for livestock, particularly sheep and goats. However, its low energy value means that it should be supplemented with carbohydrate-rich material, such as cereal straw. Potential new uses of this versatile plant species include the phytoremediation of soils contaminated by trace elements and the exploitation of its biomass as a source of renewable energy. Such applications, together with its continued use in low-intensity farming systems, should ensure that A. halimus remains a vital plant species in low-rainfall regions. [Copyright &y& Elsevier]

Selective area growth of In(Ga)N/GaN nanocolumns was performed on GaN-buffered Si(111) substrates by plasma-assisted molecular beam epitaxy. Undoped and Si-doped GaN buffer layers were first grown on Si(111) substrates, showing photoluminescence excitonic emission without traces of other low energy contributions, in particular, the yellow band. The GaN buffer surface roughness (between 10 and 14 nm, the rms value in a 10 × 10 μm2 area) was low enough to allow the fabrication of a thin (7 nm thick) well defined Ti nanohole mask, for the selective area growth. Ordered In(Ga)N/GaN nanocolumns emitting from the ultraviolet (3.2 eV) to the infrared (0.78 eV) were obtained. The morphology and the emission efficiency of the In(Ga)N/GaN nanocolumns emitting at a given wavelength could be substantially improved by tuning the In/Ga and total III/N ratios. An estimated internal quantum efficiency of 36% was derived from photoluminescence data for green emitting nanocolumns. [ABSTRACT FROM AUTHOR]

Abstract: A novel alternative for the simultaneous determination of compounds with similar structure is described, using the whole chemiluminescence-time profiles, acquired by the stopped-flow technique, in combination with mathematical treatments of multivariate calibration. The proposed method is based on the chemiluminescent oxidation of morphine and naloxone by their reaction with potassium permanganate in an acidic medium, using formaldehyde as co-factor. The whole chemiluminescence-time profiles, acquired using the stopped-flow technique in a continuous-flow system, allowed the use of the time-resolved chemiluminescence (CL) data in combination with multivariate calibration techniques, as partial least squares (PLS), for the quantitative determination of both opiate narcotics in binary mixtures. In order to achieve overcoat the additivity of the CL profiles and beside to obtain CL profiles for each drug the most separated as possible in the time, the optimum chemical conditions for the CL emission were investigated. The effect of common emission enhancers on the CL emission obtained in the oxidation reaction of these compounds in different acidic media was studied. The parameters selected were sulphuric acid 1.0molL−1, permanganate 0.2mmolL−1 and formaldehyde 0.8molL−1. A calibration set of standard samples was designed by combination of a factorial design, with three levels for each factor and a central composite design. Finally, with the aim of validating the chemometric proposed method, a prediction set of binary samples was prepared. Using the multivariate calibration method proposed, the analytes were determined in synthetic samples, obtaining recoveries of 97–109%. [Copyright &y& Elsevier]

Using the ALMA data, we have studied the HC3N and continuum emission in the starburst pseudo-ring (SB pseudo-ring) and the circumnuclear disc (CND) of the SB/active galactic nucleus (AGN) composite galaxy NGC 1068. We have detected emission from vibrationally excited HC3N (HC3N*) only towards one star-forming region of the SB pseudo-ring. Remarkably, HC3N* was not detected towards the CND despite its large HC3N v = 0 column density. From local thermodynamic equilibrium (LTE) and non-LTE modelling of HC3N*, we obtained a dust temperature (T dust) of ∼250 K and a density |$(n_{\text{H}_2}) \text{ of }6\times 10^5$|  cm−3 for this star-forming region. The estimated infrared (IR) luminosity of 5.8 × 108 L⊙ is typical of proto-superstar clusters (proto-SSCs) observed in the SB galaxy NGC 253. We use the continuum emissions at 147 and 350 GHz, along with CO and Pa α, to estimate the ages of other 14 SSCs in the SB pseudo-ring. We find the SSCs to be associated with the region connecting the nuclear bar with the SB pseudo-ring, supporting the inflow scenario. For the CND, our analysis yields T dust ≤ 100 K and |$n_{\text{H}_2}\sim (3\!-\!6)\times 10^5$|  cm−3. The very different dust temperatures found for the CND and the proto-SSC indicate that, while the dust in the proto-SSC is being efficiently heated from the inside by the radiation from massive protostars, the CND is being heated externally by the AGN, which in the IR optically thin case can only heat the dust to 56 K. We discuss the implications of the non-detection of HC3N* near the luminous AGN in NGC 1068 on the interpretation of the HC3N* emission observed in the SB/AGN composite galaxies NGC 4418 and Arp 220. [ABSTRACT FROM AUTHOR]

High-quality InN nanocolumns grown by molecular beam epitaxy on n-type Si(111) have been electrically characterized by atomic force microscopy. Current-voltage characteristics were measured on InN nanocolumns with similar heights but different diameters. The conductivity scales the nanocolumns reciprocal diameter, pointing to the nanocolumn lateral surface as the main conduction path. These results, opposing those found in undoped GaN nanocolumns where the conductivity is rather independent of the diameter (conduction through the volume), agree well with a model that predicts electron accumulation by Fermi level pinning within the conduction band on nonpolar (m plane) InN surfaces reconstructed under In-rich conditions. [ABSTRACT FROM AUTHOR]

This report presents a novel methodology based in the quickly acquisition of full UV–vis range spectra combined with the joint determination of kinetic parameters and chemiluminescence signals. Then this technique allows obtaining three-dimensional chemiluminescence spectra profiles containing kinetic and spectroscopic information. That is especially useful for resolving mixtures of luminophors because of more analytical information for each analyte is available increasing the selectivity relative to conventional chemiluminescence methods. To accomplish this, a conventional Back-Thinned CCD detector is used and the three-dimensional chemiluminescence spectra is subsequently processed so that two-dimensional spectra with different trajectories can be obtained by dedicated software CLTotal. The potential of the proposed analytical methodology was assessed for the simultaneous determination of two polycyclic aromatic hydrocarbons. The chemiluminescent reaction between DNPO and hydrogen peroxide induced by their presence was used to record 3D spectra and the software CLTotal to subsequently construct linear variable-angle trajectories in the spectra, in order to obtain more selective 2D spectra facilitating the simultaneous determination of the analytes. The results of the statistical analysis testify to the usefulness of the proposed method for the intended purpose. Unlabelled Image • The chemiluminiscence turns into an autonomous methodology of analysis. • 3D kinetic-spectrometry chemiluminescent spectra can be processed. • A powerful tool for fast multicomponent analysis in complex matrices. • Application to the resolution of a mixture containing two PAHs. [ABSTRACT FROM AUTHOR]

The effects of Si doping on the growth mode and residual strain of GaN layers grown on Si(111) substrates by plasma-assisted molecular beam epitaxy are studied by Raman scattering and photoluminescence. As the Si concentration increases a progressive decrease of the high-energy E[sub 2] mode frequency is observed, together with a redshift of the excitonic emission. Both effects indicate an enhancement of the biaxial tensile strain of thermal origin for increasing doping level, which is confirmed by x-ray diffraction measurements. Beyond Si concentrations of 5x10[sup 18] cm[sup -3] both the phonon frequency and the exciton emission energy increase again. This change indicates a partial strain relaxation due to a change in the growth mode. © 2001 American Institute of Physics. [ABSTRACT FROM AUTHOR]

We demonstrate the isolation of two free carrier scattering mechanisms as a function of radial band bending in InN nanowires via universal mobility analysis, where effective carrier mobility is measured as a function of effective electric field in a nanowire field-effect transistor. Our results show that Coulomb scattering limits effective mobility at most effective fields, while surface roughness scattering only limits mobility under very high internal electric fields. High-energy α particle irradiation is used to vary the ionized donor concentration, and the observed decrease in mobility and increase in donor concentration are compared to Hall effect results of high-quality InN thin films. Our results show that for nanowires with relatively high doping and large diameters, controlling Coulomb scattering from ionized dopants should be given precedence over surface engineering when seeking to maximize nanowire mobility. [ABSTRACT FROM AUTHOR]

The band bending and carrier concentration profiles as a function of depth below the surface for oxidized InxGa1-xN alloys with a composition range of 0.39≤x≤1.00 are investigated using x-ray photoelectron, infrared reflection, and optical absorption spectroscopies, and solutions of Poisson’s equation within a modified Thomas–Fermi approximation. All of these InGaN samples exhibit downward band bending ranging from 0.19 to 0.66 eV and a high surface sheet charge density ranging from 5.0×1012 to 1.5×1013 cm-2. The downward band bending is more pronounced in the most In-rich InGaN samples, resulting in larger near-surface electron concentrations. [ABSTRACT FROM AUTHOR]

The morphology of GaN samples grown by plasma-assisted molecular beam epitaxy on Si(111) was systematically studied as a function of impinging Ga/N flux ratio and growth temperature (730–850 °C). Two different growth regimes were identified: compact and nanocolumnar. A growth diagram was established as a function of growth parameters, exhibiting the transition between growth regimes, and showing under which growth conditions GaN cannot be grown due to thermal decomposition and Ga desorption. Present results indicate that adatoms diffusion length and the actual Ga/N ratio on the growing surface are key factors to achieve nanocolumnar growth. [ABSTRACT FROM AUTHOR]

This work studies the effect of four different types of buffer layers on the structural and optical properties of InGaN layers grown on Si(111) substrates and their correlation with electrical characteristics. The vertical electrical conduction of n-InGaN/buffer-layer/p-Si heterostructures, with In composition near 46%, which theoretically produces an alignment of the bands, is analyzed. Droplet elimination by radical-beam irradiation was successfully applied to grow high quality InGaN films on Si substrates for the first time. Among several buffer choices, an AlN buffer layer with a thickness above 24 nm improves the structural and optical quality of the InGaN epilayer while keeping a top to bottom ohmic behavior. These results will allow fabricating double-junction InGaN/Si solar cells without the need of tunnel junctions between the two sub-cells, therefore simplifying the device design. [ABSTRACT FROM AUTHOR]

Abstract: GaN and InGaN nanocolumns of various compositions are studied by room-temperature photoluminescence (PL) under different ambient conditions. GaN nanocolumns exhibit a reversible quenching upon exposure to air under constant UV excitation, following a t −1/2 time dependence and resulting in a total reduction of intensity by 85–90%, as compared to PL measured in vacuum, with no spectral change. This effect is not observed when exposing the samples to pure nitrogen. We attribute this effect to photoabsorption and photodesorption of oxygen that modifies the surface potential bending. InGaN nanocolumns, under the same experimental conditions do not show the same quenching features: The high-energy part of the broad PL line is not modified by exposure to air, whereas a lower-energy part, which does quench by 80–90%, can now be distinguished. We discuss the different behaviors in terms of carrier localization and possible composition or strain gradients in the InGaN nanocolumns. [Copyright &y& Elsevier]

Background: Procalcitonin is released in response to bacterial infection and it is not released in Inflammatory and viral diseases. Objective: To show the diagnostic efficacy and prognostic value of procalcitonin for sepsis. Methods: A consecutive series of 103 patients with suspected sepsis were admitted to the intensive care unit over a 2-year period. During the first 24 hours of the admission procalcitonin, C-reactive protein, and complement proteins were determined. The diagnostic efficacy was tested with predictive values, likelihood ratios, receiver operating characteristic curves, and multiple logistic regression. The association of procalcitonin with mortality was assessed by the Multivariate Cox proportional hazards model. Results: Procalcitonin had a better positive likelihood ratio than C-reactive protein -2.2 (95% confidence interval: 1.3-3.7) versus 1.1 (95% confidence interval: 0.9-1.2). Sequential Organ Failure Assessment yielded the highest discriminative value, with an area under the curve of 0.82 (95% confidence interval: 0.73-0.92), followed by procalcitonin (0.81; 95% confidence interval: 0.72-0.89). Multivariate regression analysis showed procalcitonin (adjusted odds ratio: 3.8; 95% confidence interval: 1.2-11.8) and Sequential Organ Failure Assessment score (adjusted odds ratio: 5.3; 95% confidence interval: 1.4-19.9) as the only variables independently associated with infection. Multivariate Cox regression analysis revealed that procalcitonin was not independently associated with mortality. Conclusions: The diagnostic accuracy of procalcitonin was higher than C-reactive protein and complement proteins. Procalcitonin in combination with Sequential Organ Failure Assessment was useful to diagnose infection. C-reactive protein, Sequential Organ Failure Assessment score, age, and gender showed to be helpful to improve the prediction of mortality risk, but not procalcitonin. [ABSTRACT FROM AUTHOR]

Low-temperature photoluminescence is studied in detail in GaN nanocolumns (NCs) grown by plasma-assisted molecular beam epitaxy under various conditions (substrate temperature and impinging Ga/N flux ratio). The relative intensities of the different emission lines, in particular those related to structural defects, appear to be correlated with the growth conditions, and clearly linked to the NC sample morphology. We demonstrate, in particular, that all lines comprised between 3.10 and 3.42 eV rapidly lose intensity when the growth conditions are such that the NC coalescence is reduced. The well-known line around 3.45 eV, characteristic of GaN NC samples, shows, however, a behavior that is exactly the opposite of the other lines, namely, for growth conditions leading to reduced NC coalescence, this line tends to become more prominent, thus proving to be intrinsic to individual GaN NCs. [ABSTRACT FROM AUTHOR]

This work reports on the growth by molecular beam epitaxy and characterization of InN/InGaN multiple quantum wells (MQWs) emitting at 1.5 μm. X-ray diffraction (XRD) spectra show satellite peaks up to the second order. Estimated values of well (3 nm) and barrier (9 nm) thicknesses were derived from transmission electron microscopy and the fit between experimental data and simulated XRD spectra. Transmission electron microscopy and XRD simulations also confirmed that the InGaN barriers are relaxed with respect to the GaN template, while the InN MQWs grew under biaxial compression on the InGaN barriers. Low temperature (14 K) photoluminescence measurements reveal an emission from the InN MQWs at 1.5 μm. Measurements as a function of temperature indicate the existence of localized states, probably due to InN quantum wells' thickness fluctuations as observed by transmission electron microscopy. [ABSTRACT FROM AUTHOR]

Transmission electron microscopy is used to investigate GaN layers grown on Si(111) substrates by plasma-assisted molecular-beam epitaxy. These layers were grown on top of different AlN buffer layers. Multiple-beam dark-field techniques applied to both cross-sectional and planar-view samples show the presence of inversion domains. These domains grow directly from the interface with the Si(111) substrate. Such observations are related, as in the case of growth on sapphire, to the symmetry difference between wurtzite and diamond. © 2001 American Institute of Physics. [ABSTRACT FROM AUTHOR]

We report on the fabrication and characterization of Schottky barrier photodetectors based on Si-doped Al[sub 0.35]Ga[sub 0.65]N layers grown on Si(111) substrates, for solar UV-band monitoring (λ<320 nm). The epilayers have been obtained by plasma-assisted molecular-beam epitaxy, showing a full width at half maximum of 15 arcmin in x-ray diffraction measurements. A very high visible rejection (>10[sup 4]) and a responsivity of 5 mA/W at 257 nm are reached. The detector time response is limited by the resistancexcapacitance product, with a minimum time constant of 20 ns in the zero-load-resistance limit. After photodiode voltage breakdown, the effect on the detector response is discussed. © 2000 American Institute of Physics. [ABSTRACT FROM AUTHOR]