Cocaine use disorder criteria in a clinical sample: an analysis using Item Response Theory, factor analysis, and network analysis.

Background: The conceptualization of substance use disorders (SUDs) was modified in successive editions of the DSM. Dimensionality and inclusion/exclusion of several criteria was studied using various analytic approaches.Objective: The study aimed to deepen our knowledge of the interrelationships between the diagnostic criteria for cocaine use disorder (CUD), applying three different analytical techniques: factor analysis, Item Response Theory (IRT) models, and network analysis.Methods: 425 (85.4% male) outpatients were evaluated for CUD using the Substance Dependence Severity Scale. Confirmatory Factor Analysis, 2-parameter logistic model (IRT) and network analysis were applied to analyze the relationships between the diagnostic criteria.Results: The results show that "legal problems" criterion is not congruent with the CUD measure on three analyses. Also, network analysis suggests the usefulness of the "craving" criterion. The criterion "quit/control" is the one that presents the best centrality indices and expected influence, showing strong relationships with the criteria of "craving," "tolerance," "neglect roles" and "activities given up."Conclusions: Network analysis appears to be a useful and complementary technique to factor analysis and IRT for understanding CUD. The "quit/control" criterion emerges as a central criterion to understand CUD.

Structural and optical properties of self-assembled AlN nanowires grown on SiO2/Si substrates by molecular beam epitaxy.

Self-assembled AlN nanowires (NWs) are grown by plasma-assisted molecular beam epitaxy (PAMBE) on SiO2/Si (111) substrates. Using a combination of in situ reflective high energy electron diffraction and ex situ x-ray diffraction (XRD), we show that the NWs grow nearly strain-free, preferentially perpendicular to the amorphous SiO2 interlayer and without epitaxial relationship to Si(111) substrate, as expected. Scanning electron microscopy investigation reveals significant NWs coalescence, which results in their progressively increasing diameter and formation of columnar structures with non-hexagonal cross-section. Making use of scanning transmission electron microscopy (STEM), the NWs initial diameters are found in the 20-30 nm range. In addition, the formation of a thin (≈30 nm) polycrystalline AlN layer is observed on the substrate surface. Regarding the structural quality of the AlN NWs, STEM measurements reveal the formation of extended columnar regions, which grow with a virtually perfect metal-polarity wurtzite arrangement and with extended defects only sporadically observed. Combination of STEM and electron energy loss spectroscopy reveals the formation of continuous aluminum oxide (1-2 nm) on the NW surface. Low temperature photoluminescence measurements reveal a single near-band-edge (NBE) emission peak, positioned at 6.03 eV (at 2 K), a value consistent with nearly zero NW strain evidenced by XRD and in agreement with the values obtained on AlN bulk layers synthesized by other growth techniques. The significant full-width-at-half-maximum of NBE emission, found at ≈20 meV (at 2 K), suggests that free and bound excitons are mixed together within this single emission band. Finally, the optical properties of the hereby reported AlN NWs grown by PAMBE are comprehensively compared to optical properties of bulk, epitaxial and/or columnar AlN grown by various techniques such as: physical vapor transport, metal organic vapor phase epitaxy, metal organic chemical vapor deposition and molecular beam epitaxy.

Investigating the nutritional advice and support given to colorectal cancer survivors in the UK: is it fit for purpose and does it address their needs?

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.

Selective area growth of AlN/GaN nanocolumns on (0001) and (11-22) GaN/sapphire for semi-polar and non-polar AlN pseudo-templates.

Despite the strong interest in optoelectronic devices working in the deep ultraviolet range, no suitable low cost, large-area, high-quality AlN substrates have been available up to now. The aim of this work is the selective area growth of AlN nanocolumns by plasma assisted molecular beam epitaxy on polar (0001) and semi-polar (11-22) GaN/sapphire templates. The resulting AlN nanocolumns are vertically oriented with semi-polar {1-103} top facets when grown on (0001) GaN/sapphire, or oriented at 58° from the template normal and exposing {1-100} non-polar top facets when growing on (11-22) GaN/sapphire, in both cases reaching filling factors ≥80%. In these kinds of arrays each nanostructure could function as a building block for an individual nano-device or, due to the large filling factor values, the overall array top surfaces could be seen as a quasi (semi-polar or non-polar) AlN pseudo-template.

Compliance-guided versus FiO2-driven positive-end expiratory pressure in patients with moderate or severe acute respiratory distress syndrome according to the Berlin definition.

OBJECTIVE: To study the effect of setting positive end-expiratory pressure (PEEP) in an individualized manner (based on highest static compliance) compared to setting PEEP according to FiO2 upon mortality at 28 and 90 days, in patients with different severity acute respiratory distress syndrome (ARDS). SETTING: A Spanish medical-surgical ICU. DESIGN: A post hoc analysis of a randomized controlled pilot study. PATIENTS: Patients with ARDS. INTERVENTIONS: Ventilation with low tidal volumes and pressure limitation at 30cmH2O, randomized in two groups according to the method used to set PEEP: FiO2-guided PEEP group according to FiO2 applied and compliance-guided group according to the highest compliance. PRIMARY VARIABLES OF INTEREST: Demographic data, risk factors and severity of ARDS, APACHE II and SOFA scores, daily Lung Injury Score, ventilatory measurements, ICU and hospital stay, organ failure and mortality at day 28 and 90 after inclusion. RESULTS: A total of 159 patients with ARDS were evaluated, but just 70 patients were included. Severe ARDS patients showed more organ dysfunction-free days at 28 days (12.83±10.70 versus 3.09±7.23; p=0.04) and at 90 days (6.73±22.31 vs. 54.17±42.14, p=0.03), and a trend toward lower 90-days mortality (33.3% vs. 90.9%, p=0.02), when PEEP was applied according to the best static compliance. Patients with moderate ARDS did not show these effects. CONCLUSIONS: In patients with severe ARDS, individualized PEEP selection based on the best static compliance was associated to lower mortality at 90 days, with an increase in organ dysfunction-free days at 28 and 90 days.

Titanium induced polarity inversion in ordered (In,Ga)N/GaN nanocolumns.

We report on the formation of polarity inversion in ordered (In,Ga)N/GaN nanocolumns grown on a Ti-masked GaN-buffered sapphire substrate by plasma assisted molecular beam epitaxy. High-resolution transmission electron microscopy and electron energy-loss spectroscopy reveal a stacking fault-like planar defect at the homoepitaxial GaN interface due to Ti incorporation, triggering the generation of N-polar domains in Ga-polar nanocolumns. Density functional theory calculations are applied to clarify the atomic configurations of a Ti monolayer occupation on the GaN (0002) plane and to prove the inversion effect. The polarity inversion leads to an enhanced indium incorporation in the subsequent (In,Ga)N segment of the nanocolumn. This study provides a deeper understanding of the effects of Ti mask in the well-controlled selective area growth of (In,Ga)N/GaN nanocolumns.

Light-emitting-diodes based on ordered InGaN nanocolumns emitting in the blue, green and yellow spectral range.

The growth of ordered arrays of InGaN/GaN nanocolumnar light emitting diodes by molecular beam epitaxy, emitting in the blue (441 nm), green (502 nm), and yellow (568 nm) spectral range is reported. The device active region, consisting of a nanocolumnar InGaN section of nominally constant composition and 250 to 500 nm length, is free of extended defects, which is in strong contrast to InGaN (planar) layers of similar composition and thickness. Electroluminescence spectra show a very small blue shift with increasing current (almost negligible in the yellow device) and line widths slightly broader than those of state-of-the-art InGaN quantum wells.

Guidelines for the prevention of ventilator-associated pneumonia and their implementation. The Spanish "Zero-VAP" bundle.

BACKGROUND: "Zero-VAP" is a proposal for the implementation of a simultaneous multimodal intervention in Spanish intensive care units (ICU) consisting of a bundle of ventilator-associated pneumonia (VAP) prevention measures. METHODS/DESIGN: An initiative of the Spanish Societies of Intensive Care Medicine and of Intensive Care Nurses, the project is supported by the Spanish Ministry of Health, and participation is voluntary. In addition to guidelines for VAP prevention, the "Zero-VAP" Project incorporates an integral patient safety program and continuous online validation of the application of the bundle. For the latter, VAP episodes and participation indices are entered into the web-based Spanish ICU Infection Surveillance Program "ENVIN-HELICS" database, which provides continuous information about local, regional and national VAP incidence rates. Implementation of the guidelines aims at the reduction of VAP to less than 9 episodes per 1000 days of mechanical ventilation. A total of 35 preventive measures were initially selected. A task force of experts used the Grading of Recommendations, Assessment, Development and Evaluation Working Group methodology to generate a list of 7 basic "mandatory" recommendations (education and training in airway management, strict hand hygiene for airway management, cuff pressure control, oral hygiene with chlorhexidine, semi-recumbent positioning, promoting measures that safely avoid or reduce time on ventilator, and discouraging scheduled changes of ventilator circuits, humidifiers and endotracheal tubes) and 3 additional "highly recommended" measures (selective decontamination of the digestive tract, aspiration of subglottic secretions, and a short course of iv antibiotic). DISCUSSION: We present the Spanish VAP prevention guidelines and describe the methodology used for the selection and implementation of the recommendations and the organizational structure of the project. Compared to conventional guideline documents, the associated safety assurance program, the online data recording and compliance control systems, as well as the existence of a pre-defined objective are the distinct features of "Zero VAP".

Developing an accurate and efficient tool for the internalizing spectrum: A simulation study of the adaptive algorithm to the Inventory of Depression and Anxiety Symptoms II (IDAS-II).

OBJECTIVES: This research simulates an adaptive version of the IDAS-II (IDAS-CAT). METHODS: 2021 participants from both community (n = 1692) and patients (n = 329) samples completed the IDAS-II. Item response theory metric properties of the IDAS-II full test and the 20-items of the general depression (GD) scale were obtained. The efficiency and accuracy of different computerized adaptive algorithms were simulated. Different subsamples completed additional external measures in order to gather evidence of validity of the scores estimated with the simulated adaptive algorithms selected. RESULTS: Both unidimensional computerized adaptive testing algorithm selected for the GD scale and the bifactor model chosen for the full test, allow 70% reduction in the length of administration, maintaining a measurement error below 0.30 on the general and 0.50 on the specific factors. Results show high correlations of the scores estimated with the adaptive algorithms and the estimates based on the full test, as well as correlations with external criteria almost equal to those generated with the full test. CONCLUSIONS: IDAS-CAT could be a reliable and fast tool for measuring internalizing spectrum.

Selective area growth of In(Ga)N/GaN nanocolumns by molecular beam epitaxy on GaN-buffered Si(111): from ultraviolet to infrared emission.

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 µm(2) 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.

Assessing Internalizing Symptoms and Their Relation with Levels of Impairment: Evidence-Based Cutoffs for Interpreting Inventory of Depression and Anxiety Symptoms (IDAS-II) Scores.

Tests and scales measuring psychological disorders should provide information about how scores relate to other constructs such as quality of life or functional impairment. Such information is necessary to allow that their scores contribute to clinical decision making. The current study analyzes the clinical utility of the Spanish version of the Inventory for Depression and Anxiety Symptoms (IDAS-II) to discriminate between different levels of functional impairment and identify the IDAS-II scales that contribute most to explaining impairment. The total sample (N = 1390) consists of two subsamples: a community sample of the general population (n = 1072) selected by random sampling; and a sample of patients (n = 318) from public and private mental health services. The Spanish IDAS-II for measuring internalizing symptoms and WHODAS 2.0 for measuring impairment were administered to all participants. All scales show statistically significant higher scores in the patient sample, with Cohen's d effect sizes values greater than 0.30, except for well-being (d = 0.19). The cutoff values and their confidence intervals do not overlap with the means of either the community or patient sample. AUC values for most of the scales are above .70, except for appetite gain, ordering, euphoria, cleaning, and well-being. Multiple linear regression model using IDAS-II scales explain 57.1% of the variance of the WHODAS 2.0 (F 12.1377 = 155.305; p < .001). Cutoff values provided allow us to reliably differentiate between the patients and community samples. Spanish IDAS-II scores show greater sensitivity and specificity in detecting those with greater impairment. General Depression, Lassitude, Panic and Claustrophobia contribute to impairment in a greater extent. Knowledge of which symptoms are most related with impairment, allows healthcare providers to improve treatment planning based on empirical evidence.

Women in urology: what is their current situation in Spain?

OBJECTIVE: To analyze the current state of women in urology in Spain. MATERIAL AND METHODS: Descriptive study based on the results of an online survey sent between February and April 2020 through the database of the Residents and Young Urologists group (RAEU) of the Spanish Association of Urology (AEU). Characteristics of the survey and its results were analyzed. RESULTS: In total, 257 responses were obtained from 210 women (81.71%) and 47 men (18.29%) belonging to 111 hospitals. Statistically significant differences were observed (p < 0.001) with a higher proportion of men in all categories except for the group of young female and male attendings (29-39 years, p = 0.789), and the group of female residents against male residents (p = 0.814). The number of men was higher in hospitals with subspecialty units except for the Pelvic Floor Unit, where no statistically significant difference was observed (p = 0.06). Regarding positions of responsibility, only 7 out of 111 hospitals had female Department Chiefs. CONCLUSIONS: Women's representation in urology is increasing, mainly due to the younger generations. However, the access of these women to relevant positions is anecdotal.

Plasmon excitation in electron energy-loss spectroscopy for determination of indium concentration in (In,Ga)N/GaN nanowires.

We demonstrate the potential of low-loss electron energy-loss spectroscopy in transmission electron microscopy as a quick and straightforward method to determine the local indium compositions in (In,Ga)N/GaN nanowires. The (In,Ga)N/GaN nanowire heterostructures are grown by plasma assisted molecular beam epitaxy on Si(111) substrates in a self-assembled way, and on patterned GaN templates in an ordered way. A wide range of indium contents is realized by varying the substrate temperatures. The plasmon peak in low-loss electron energy-loss spectroscopy exhibits a linear relation with respect to indium concentration in (In,Ga)N nanowires, allowing for a direct compositional analysis. The high spatial resolution of this method in combination with structural information from transmission electron microscopy will contribute to a basic understanding of the lattice pulling effect during (In,Ga)N/GaN nanowire growth.

[Neuropsychiatric symptoms in people living with dementia related to COVID-19 pandemic lockdown. Exploratory systematic review]. / Síntomas neuropsiquiátricos en personas con demencia relacionados con el confinamiento por la pandemia de la COVID-19. Revisión sistemática exploratoria.

INTRODUCTION: Neuropsychiatric symptoms are common in patients with mild cognitive impairment and dementia. This symptomatology can appear or be exacerbated with changes in routine and in the patient's usual environment. The lockdown situation during the COVID-19 pandemic has meant a drastic and unexpected change in the daily life of the general population, with a particular impact on the most physically and mentally vulnerable groups, including patients with cognitive impairment. AIM: To know the impact of lockdown measures imposed due to the COVID-19 pandemic on neuropsychiatric symptomatology in people with mild cognitive impairment and dementia. MATERIALS AND METHODS: Exploratory systematic review, in accordance with the PRISMA guidelines, of Pubmed and Psycinfo databases papers published from January 2020 to April 2021 which related confinement due to COVID-19 with the presentation or worsening of neuropsychiatric symptoms in patients with mild cognitive impairment mild or dementia. RESULTS: Worsening of neuropsychiatric symptoms was observed in patients with dementia and mild cognitive impairment, especially agitation/aggression, anxiety, depression and apathy. Neuropsychiatric symptoms were more common in patients with dementia than in those with mild cognitive impairment, although their typology varied depending on the severity of dementia. CONCLUSIONS: During lockdown a worsening in the psychobehavioral area has been observed in people with mild cognitive impairment or dementia. Therefore, considerations arise on the need of promoting social contact in people with mild cognitive impairment and dementia, avoiding situations of isolation and low stimulation.

TITLE: Síntomas neuropsiquiátricos en personas con demencia relacionados con el confinamiento por la pandemia de la COVID-19. Revisión sistemática exploratoria.Introducción. En pacientes con deterioro cognitivo leve y demencia, son frecuentes los síntomas neuropsiquiátricos, que pueden aparecer o exacerbarse ante los cambios en la rutina y el entorno habitual del paciente. La situación de confinamiento durante la pandemia de la COVID-19 ha supuesto un cambio en la vida cotidiana de la población general, con especial impacto en los grupos más vulnerables, como los pacientes con afectación cognitiva. Objetivo. Conocer la repercusión de las medidas de confinamiento y cuarentena impuestas por la pandemia de la COVID-19 en la sintomatología neuropsiquiátrica en personas con deterioro cognitivo leve (DCL) y demencia. Materiales y métodos. Revisión sistemática exploratoria, siguiendo las directrices PRISMA, de artículos en las bases datos PubMed y PsycINFO publicados entre enero de 2020 y abril de 2021, que relacionaron el confinamiento por la COVID-19 con la presentación o el empeoramiento de síntomas neuropsiquiátricos en pacientes con DCL o con demencia. Resultados. Se observó un empeoramiento de los síntomas neuropsiquiátricos en los pacientes con demencia y DCL, especialmente agitación/agresión, ansiedad, depresión y apatía. Los síntomas neuropsiquiátricos fueron más comunes en los pacientes con demencia que en los que presentaban DCL, aunque su tipología varió en función de la gravedad de la demencia. Conclusiones. Durante el confinamiento se ha objetivado un detrimento en la esfera psicoconductual en personas con DCL o demencia. Consecuentemente, surge la reflexión sobre la necesidad de fomentar el contacto social en las personas con DCL y demencia, evitando las situaciones de aislamiento y baja estimulación.

Polarity determination by electron energy-loss spectroscopy: application to ultra-small III-nitride semiconductor nanocolumns.

Channeling-enhanced electron energy-loss spectroscopy is applied to determine the polarity of ultra-small nitride semiconductor nanocolumns in transmission electron microscopy. The technique demonstrates some practical advantages in the nanostructure analysis, especially for feature sizes of less than 50 nm. We have studied GaN and (Al, Ga)N nanocolumns grown in a self-assembled way by molecular beam epitaxy directly on bare Si(111) substrates and on AlN buffer layers, respectively. The GaN nanocolumns on Si show an N polarity, while the (Al, Ga)N nanocolumns on an AlN buffer exhibit a Ga polarity. The different polarities of nanocolumns grown in a similar procedure are interpreted in terms of the specific interface bonding configurations. Our investigation contributes to the understanding of polarity control in III-nitride nanocolumn growth.

Flow injection chemiluminescence determination of vitamin B12 using on-line UV-persulfate photooxidation and charge coupled device detection.

A sensitive chemiluminescence method for vitamin B(12) using a charge-coupled device (CCD) photodetector combined with on-line UV-persulfate oxidation in a simple continuous flow system has been developed. The principle for the determination of vitamin B(12) is based on the enhancive effect of cobalt (II) on the chemiluminescence reaction between luminol and percarbonate in alkaline medium. In addition, percarbonate has been investigated and proposed as a powerful source of hydrogen peroxide as oxidant agent in this chemiluminescence reaction. The digestion of vitamin B(12) to release the cobalt (II) is reached by UV irradiation treatment in a persulfate medium. The CCD detector, directly connected to the flow cell, is used with the continuous flow manifold to obtain the full spectral characteristics of cobalt (II) catalyzed luminol-percarbonate reaction. The vitamin B(12) oxidation process and chemical conditions for the chemiluminescence reaction were investigated and optimized. The increment of the emission intensity was proportional to the concentration of vitamin B(12) , giving a second-order calibration graph over the cobalt (II) concentration range from 10 to 5000 µg L(-1)(r(2) = 0.9985) with a detection limit of 9.3 µg L(-1). The proposed method was applied to the determination of vitamin B(12) in different kinds of pharmaceuticals.

Decision making in substance use disorder patients: Reliability, convergent validity and sensitivity to change of a new behavioral measure.

OBJECTIVE: The Iowa Gambling Task (IGT) and the Delay Discounting Test (DDT) are two of the most widely used decision-making tests within the field of addiction research. The IGT creates a context of uncertainty where immediate rewards or long-term benefits are chosen, whilst the DDT measures the change in value of a reward as the time taken to obtain it increases. The objective of this study was to analyze the psychometric properties of a new task: Deciding about your health (DAYH), which integrates both components. METHOD: Longitudinal observational study. The sample was composed of 97 patients being treated for cocaine use disorder. The DAYH, IGT, DDT and other instruments for measuring dependence severity were administered. Relapse was evaluated within 3 and 6 months after the baseline assessment. RESULTS: Reliability was indicated by an intraclass correlation coefficient (r) of. 80. DAYH scores showed significant relationships with IGT (r = -.237; p <.05), although not with DDT (r =.048) scores. A relationship was also found between DAYH and dependency severity (r = -.213; p <.05) and craving (r = -.231; p <.05). The DAYH scores showed sensitivity to change, and the capacity to predict relapse. CONCLUSIONS: These findings indicate the utility of DAYH for exploring decision-making in patients with substance use disorders. The relationships with IGT and DDT also indicate the need to further investigate how decisions are made in various contexts of choice.

Spanish Adaptation of the Inventory of Depression and Anxiety Symptoms (IDAS-II) and a study of its psychometric properties.

BACKGROUND: The Inventory of Depression and Anxiety Symptoms (IDAS-II) is composed of 99 items organized into 18 specific scales that provides dimensional assessment of depression, anxiety and bipolar symptoms. To date, IDAS-II is only available in the English and Turkish population. The main purpose of this study is to adapt the IDAS-II to the Spanish population and to assess the psychometric properties. METHODS: Participants included community adults (n = 620) and college students (n = 378). All participants completed the Beck Depression Inventory-II, Beck Anxiety Inventory, Hypomania Check List-32, Post-traumatic Stress Disorder Checklist-Civilian Version and Obsessive-Compulsive Inventory-Revised, in addition to the Spanish version of the IDAS-II. RESULTS: The results indicate good internal consistency and high temporal stability of the Spanish version of the IDAS-II. Confirmatory factor analyses show for the first time that the three-factor structure of the IDAS-II (Distress, Obsessions/Fear, and Positive Mood) loads on a second order factor, labeled "Internalizing" according to the Hierarchical Taxonomy Of Psychopathology (HiTOP). LIMITATIONS: Study was conducted exclusively on student and community samples and some of the measures used as gold-standard have presented limitations CONCLUSIONS: According to previous studies, the results supported the convergent and discriminant validity of the majority of IDAS-II scales. IDAS-II is useful in assessing the severity of depression, anxiety and bipolar symptoms in research contexts in a Spanish population according to the HiTOP model. However, more evidence is required to prove the adequate functioning of the IDAS-II in clinical samples.

Innovative design of a methodology for the simultaneous determination of compounds by kinetic-spectroscopy three-dimensional chemiluminescence.

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.

Biochar reduces volatile organic compounds generated during chicken manure composting.

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.