Combining transcranial direct current stimulation with hand robotic rehabilitation in chronic stroke patients: a double blind randomized clinical trial.

OBJECTIVE: This study aimed to assess the impact of combining transcranial direct current stimulation (tDCS) with end-effector robot-assisted treatment (RAT) on upper limb function, spasticity, and hand dexterity in chronic stroke patients. DESIGN: This was a prospective, double-blind randomized trial with 20 equally allocated stroke patients. The experimental group received dual-tDCS (anode over affected M1, cathode over contralateral M1) alongside RAT, while the control group received sham tDCS with the same electrode placement + RAT. Each patient underwent 20 combined tDCS and RAT sessions. The primary outcome measure was the Fugl Meyer Upper Limb motor score (mFM-UL), with secondary outcomes including AMADEO® kinematic measures, Action Research Arm Test (ARAT), and Functional Independence Measure (FIM). Assessments were conducted at baseline, post-rehabilitation, and three months later. RESULTS: Combining bilateral tDCS with RAT did not yield additional improvements in mFM-UL, FIM, or ARAT scores among stroke patients. However, the real tDCS group showed enhanced finger flexion in the affected hand based on AMADEO® kinematic measures. CONCLUSION: The addition of tDCS to RAT did not result in significant overall functional improvements in chronic stroke patients. However, a benefit was observed in finger flexion of the affected hand.

Is the Combination of Robot-Assisted Therapy and Transcranial Direct Current Stimulation Useful for Upper Limb Motor Recovery? A Systematic Review with Meta-Analysis.

Stroke is the third leading cause of disability in the world, and effective rehabilitation is needed to improve lost functionality post-stroke. In this regard, robot-assisted therapy (RAT) and transcranial direct current stimulation (tDCS) are promising rehabilitative approaches that have been shown to be effective in motor recovery. In the past decade, they have been combined to study whether their combination produces adjuvant and greater effects on stroke recovery. The aim of this study was to estimate the effectiveness of the combined use of RATs and tDCS in the motor recovery of the upper extremities after stroke. After reviewing 227 studies, we included nine randomised clinical trials (RCTs) in this study. We analysed the methodological quality of all nine RCTs in the meta-analysis. The analysed outcomes were deficit severity, hand dexterity, spasticity, and activity. The addition of tDCS to RAT produced a negligible additional benefit on the effects of upper limb function (SMD -0.09, 95% CI -0.31 to 0.12), hand dexterity (SMD 0.12, 95% CI -0.22 to 0.46), spasticity (SMD 0.04, 95% CI -0.24 to 0.32), and activity (SMD 0.66, 95% CI -1.82 to 3.14). There is no evidence of an additional effect when adding tDCS to RAT for upper limb recovery after stroke. Combining tDCS with RAT does not improve upper limb motor function, spasticity, and/or hand dexterity. Future research should focus on the use of RAT protocols in which the patient is given an active role, focusing on the intensity and dosage, and determining how certain variables influence the success of RAT.

Facile Fabrication of High-Performance Thermochromic VO2-Based Films on Si for Application in Phase-Change Devices.

This work reports on an alternative and advantageous procedure to attain VO2-based thermochromic coatings on silicon substrates. It involves the sputtering of vanadium thin films at glancing angles and their subsequent fast annealing in an air atmosphere. By adjusting thickness and porosity of films as well as the thermal treatment parameters, high VO2(M) yields were achieved for 100, 200, and 300 nm thick layers treated at 475 and 550 °C for reaction times below 120 s. Comprehensive structural and compositional characterization by Raman spectroscopy, X-ray diffraction, and scanning-transmission electron microscopies combined with analytical techniques such as electron energy-loss spectroscopy bring to the fore the successful synthesis of VO2(M) + V2O3/V6O13/V2O5 mixtures. Likewise, a 200 nm thick coating consisting exclusively of VO2(M) is also achieved. Conversely, the functional characterization of these samples is addressed by variable temperature spectral reflectance and resistivity measurements. The best results are obtained for the VO2/Si sample with changes in reflectance of 30-65% in the near-infrared at temperatures between 25 and 110 °C. Similarly, it is also proven that the achieved mixtures of vanadium oxides can be advantageous for certain optical applications in specific infrared windows. Finally, the features of the different structural, optical, and electrical hysteresis loops associated with the metal-insulator transition of the VO2/Si sample are disclosed and compared. These remarkable thermochromic performances hereby accomplished highlight the suitability of these VO2-based coatings for applications in a wide range of optical, optoelectronic, and/or electronic smart devices.

Effect of Interfacial Schemes on the Optical and Structural Properties of InAs/GaSb Type-II Superlattices.

Incorporating an intentional strain compensating InSb interface (IF) layer in InAs/GaSb type-II superlattices (T2SLs) enhances device performance. But there is a lack of studies that correlate this approach's optical and structural quality, so the mechanisms by which this improvement is achieved remain unclear. One critical issue in increasing the performance of InAs/GaSb T2SLs arises from the lattice mismatch between InAs and GaSb, leading to interfacial strain in the structure. Not only that but also, since each side of the InAs/GaSb heterosystem does not have common atoms, there is a possibility of atomic intermixing at the IFs. To address such issues, an intentional InSb interfacial layer is commonly introduced at the InAs-on-GaSb and GaSb-on-InAs IFs to compensate for the strain and the chemical mismatches. In this report, we investigate InAs/GaSb T2SLs with (Sample A) and without (Sample B) InSb IF layers emitting in the mid-wavelength infrared (MWIR) through photoluminescence (PL) and band structure simulations. The PL studies indicate that the maximum PL intensity of Sample A is 1.6 times stronger than that of Sample B. This could be attributed to the effect of migration-enhanced epitaxy (MEE) growth mode. Band structure simulations understand the impact of atomic intermixing and segregation at T2SL IFs on the bandgap energy and PL intensity. It is observed that atomic intermixing at the IFs changes the bandgap energy and significantly affects the wave function overlap and the optical property of the samples. Transmission electron microscopy (TEM) measurements reveal that the T2SL IFs in Sample A are very rough compared to sharp IFs in Sample B, indicating a high possibility of atomic intermixing and segregation. Based on these results, it is believed that high-quality heterostructure could be achieved by controlling the IFs to enhance its structural and compositional homogeneities and the optical properties of the T2SLs.

Radiation and Dust Sensor for Mars Environmental Dynamic Analyzer Onboard M2020 Rover.

The Radiation and Dust Sensor is one of six sensors of the Mars Environmental Dynamics Analyzer onboard the Perseverance rover from the Mars 2020 NASA mission. Its primary goal is to characterize the airbone dust in the Mars atmosphere, inferring its concentration, shape and optical properties. Thanks to its geometry, the sensor will be capable of studying dust-lifting processes with a high temporal resolution and high spatial coverage. Thanks to its multiwavelength design, it will characterize the solar spectrum from Mars' surface. The present work describes the sensor design from the scientific and technical requirements, the qualification processes to demonstrate its endurance on Mars' surface, the calibration activities to demonstrate its performance, and its validation campaign in a representative Mars analog. As a result of this process, we obtained a very compact sensor, fully digital, with a mass below 1 kg and exceptional power consumption and data budget features.

Comparación de los índices de Charlson y COTE en la enfermedad pulmonar obstructiva crónica (EPOC) y su relación con la mortalidad

Resumen La morbimortalidad de la Enfermedad Pulmonar Obstructiva Crónica (EPOC) está vinculada en parte a las comorbilidades. Muchas cohortes han demostrado que las comorbilidades crónicas son más frecuentes en pacientes con EPOC que en los que no la tienen influyendo en el pronóstico final del paciente. Objetivo: Comparar los Índices Charlson y CO-morbidity Test (COTE) y su relación con la mortalidad en pacientes con EPOC. Materiales y métodos: Estudio de cohorte prospectiva seguida durante veinte años, observacional, con una visita a Diciembre de 2016. Se evaluaron e incluyeron pacientes con EPOC (definición GOLD 2017), que presentaban comorbilidades y se determinaron los Índices de Charlson y COTE y se estableció su relación con la mortalidad. Se usaron estadísticas convencionales y coeficiente de regresión lineal. Resultados: Se incluyeron 354 pacientes con EPOC (edad 66,5 ± 8,4, 66,7% hombres, exfumadores 74,2%, 56 ± 29,7 paquetes/ año). A los veinte años estaban vivos 220 (62%) y fallecieron 134 (38%). Su clasificación fue: GOLD 1 (10.16%), 2 (43,78%), 3 (37%), 4 (9,03%); A (9%), B (48,3%), C (0,6%) y D (41,8%); FEV1 post-broncodilatador 53,8 ± 20%. El índice de Charlson fue 4,1 ± 1,7 y el de COTE de 0,8 ± 0. Las comorbilidades más frecuentes fueron Hipertensión (HTA) 24,2%, Insuficiencia Cardíaca Congestiva (ICC) 12,4%, Diabetes (DBT) 8,2%, Cáncer 7,3% y Síndrome de superposición Asma - EPOC (SAOC) 3,6%. Las patologías con mayor mortalidad fueron ICC 21%, HTA 11,2%, DBT y cáncer 8,2%, Infarto Agudo de Miocardio (IAM) 6%, Síndrome de Apneas - Hipopneas del Sueño (SAHS) y SAOC 1,5%, y Fibrilación auricular (FA) 0,75%. El índice COTE correlaciona pobremente con el de Charlson (r = 0.47). Más de los dos tercios de los fallecidos tiene 4 o más puntos del Charlson. 85% de los fallecidos tienen 1 punto o menos evaluados por el índice de COTE. Conclusión: Las comorbilidades son muy frecuentes en obstrucción moderada a grave de pacientes EPOC, especialmente B y D. Las más frecuentes son DBT e HTA. Un puntaje ≥ a 4 puntos del índice Charlson discrimina mejor la mortalidad en comparación al índice de COTE. Hay una correlación pobre entre ambos índices.

Comparison between the Charlson and COTE Indices in Chronic Obstructive Pulmonary Disease (COPD) and their Relationship with Mortality

Abstract The morbidity and mortality of chronic obstructive pulmonary disease (COPD) is partly related to comorbidities. Many cohorts have shown that chronic comorbidities are more frequent in patients with COPD than in those without it, influencing the final prognosis of the patient. Objective: To compare the Charlson and CO-morbidity Test (COTE) indices and their relationship with mortality in COPD patients. Materials and Methods: A prospective, observational cohort followed during ten years with one visit in December 2016. The study included and evaluated patients with COPD (GOLD 2017 definition) who had comorbidities; we determined the Charlson and COTE indices and established their relationship with mortality. Conventional statistics and linear regression coefficient were used. Results: 354 COPD patients were evaluated (age 66.5 ± 8.4, 66.7% male, 74.2% ex-smokers, 56 ± 29.7 p/y). After ten years, 220 patients were alive (62%) and 134 had died (38%). They had the following classification: GOLD 1 (10.16%), 2 (43.78%), 3 (37%), 4 (9.03%); A (9%), B (48.3%), C (0.6%) and D (41.8%); FEV1 post-bronchodilator 53.8 ± 20%. The Charlson Index was 4.1 ± 1.7 and the COTE was 0.8 ± 0. The most frequent comorbidities were hypertension (AHT) 24.2%, congestive heart failure (CHF) 12.4%, diabetes (DBT) 8.2%, cancer 7.3%, and asthma-COPD overlap syndrome (ACOS) 3.6%. The diseases with the highest mortality rate were CHF 21%, AHT 11.2%, DBT and cancer 8.2%, acute myocardial infarction (AMI) 6%, obstructive sleep apnea-hypopnea syndrome (OSAHS) and ACOS 1.5%, and atrial fibrillation (AF) 0.75% %. The COTE index correlates poorly with the Charlson index (r = 0.47). More than two-thirds of dead patients have 4 or more Charlson points. 85% of deceased patients have 1 point or less in the COTE index. Conclusion: Comorbidities are very frequent in moderate to severe obstruction in COPD patients, especially B and D. The most frequent are DBT and AHT. A Charlson index score of ≥ 4 more accurately discriminates mortality compared to the COTE index. There is a poor correlation between both indices.

Determination of veterinary drugs in microalgae biomass from photobioreactors fed with piggery wastewater.

Concentration data of veterinary drugs in microalgae biomass collected from photobioreactors fed with piggery wastewaters are presented for the first time in this work. To this aim, a QuEChERS methodology and an ultrasound-assisted solid-liquid extraction have been assessed as sample preparation procedures with the purpose of determining 20 veterinary drugs, mainly antibiotics of different physico-chemical properties in addition to dexamethasone, fenbendazole and progesterone. Some critical operation parameters of the QuEChERS procedure were optimized by an experimental design but tetracycline, oxytetracycline, doxycycline, marbofloxacin and ciprofloxacin were not detected by the QuEChERS sample preparation. The use of a longer and thorough approach, a solid-liquid extraction with water/methanol in presence of primary secondary amine as a clean-up agent followed by solid-phase extraction on Oasis HLB cartridges, is recommended to monitor all intended analytes. The determination in extracts is carried out by ultra-high performance liquid chromatography-tandem mass spectrometry in selected reaction monitoring mode. Limits of detection about 0.2-42 ng per g of lyophilized microalgae sample, and repeatabilities about 6-46% (n = 5, RSDs) are reached. The solid-liquid extraction method was applied to microalgae biomass samples collected from a photobioreactor. Nine drugs were detected in the samples at relatively low concentration and a proportional relationship between the found concentrations and the octanol/water partition coefficients of the drugs has been outlined. Moreover, a linear ratio between the concentrations measured in biomass and effluent has been observed for most of the drugs.

Taking the pulse of a classroom with a gamified audience response system.

BACKGROUND AND OBJECTIVE: This paper presents an empirical study of a gamified mobile-based assessment approach that can be used to engage students and improve their educational performance. METHOD: A gamified audience response system called G-SIDRA was employed. Three gamification elements were used to motivate students in classroom activities: badges for achievements to increase engagement, points to indicate progression and performance in the subject and ranking for promoting competitiveness. A total of 90 medical students in a General and Descriptive Anatomy of the Locomotor System course were taught using G-SIDRA in the academic year 2019/2020. Smart bracelets were configured to collect heart rate measurements from 30 students with the aim of evaluating the impact of the gamification elements. The control group consisted of a sample of 110 students enrolled on the same course in the academic year 2016/2017 using non-gamified SIDRA. RESULTS: Statistically significant differences were found between multiple choice questions (MCQ) scores obtained by using SIDRA and G-SIDRA in the four experiments (U = 1.621,50, p < 0,01 for Exp1; U = 1.950,00, p < 0,01 for Exp2; U = 955,00, p < 0,01 for Exp3; U = 2.335,00, p < 0,01 for Exp4). In the students' final exam grades, statistically significant differences between students that used G-SIDRA as opposed to SIDRA (T(157) = 3.992; p = 0.044) were obtained. Concerning gamification elements, statistically significantly differences were found in comparing the pulse increases after and before the badge event in the four experiments (U = 2.484,00, p = 0,038 for Exp1; U = 2.109,50, p = 0,046 for Exp2; U = 1.790,50, p = 0,025 for Exp3; U = 1.557,0, p = 0,048 for Exp4). However, there are not statistically significant differences between the pulse increases after and before the ranking event in the four experiments. In a 5-point Likert-type scale, the students expressed satisfaction with G-SIDRA (M = 4.552) and thought the system helped to better understand both theoretical and practical concepts (M = 4.092). Their global assessment of the G-SIDRA platform was 4.471. CONCLUSIONS: Of the three gamification elements used in the study, only badge has an effect on heart rate. Better student responses and academic performance were achieved when using G-SIDRA. Nevertheless, more research is required to evaluate the impact of the gamification elements on the motivation, engagement and performance of students. Physiological measures are promising approaches for gamification elements evaluation.

Effects of Gamification on the Benefits of Student Response Systems in Learning of Human Anatomy: Three Experimental Studies.

This paper presents three experiments to assess the impact of gamifying an audience response system on the perceptions and educational performance of students. An audience response system called SIDRA (Immediate Audience Response System in Spanish) and two audience response systems with gamification features, R-G-SIDRA (gamified SIDRA with ranking) and RB-G-SIDRA (gamified SIDRA with ranking and badges), were used in a General and Descriptive Human Anatomy course. Students participated in an empirical study. In the academic year 2019-2020, a total of 90 students used RB-G-SIDRA, 90 students employed R-G-SIDRA in the academic year 2018-2019, and 92 students used SIDRA in the academic year 2017-2018. Statistically significant differences were found between final exam grades obtained by using RB-G-SIDRA and SIDRA, U = 39.211 adjusted p = 0.001 and RB-G-SIDRA and R-G-SIDRA U = 31.157 adjusted p = 0.015, thus finding strong evidence with respect to the benefit of the badges used in RB-G-SIDRA. Moreover, in the students' SIDRA systems scores, statistically significant differences were found between RB-G-SIDRA and SIDRA, U = -90.521 adjusted p < 0.001, and between R-G-SIDRA and SIDRA, U = -87.998 adjusted p < 0.001. Significant correlations between individual and team scores were also found in all of the tests in RB-G-SIDRA and G-SIDRA. The students expressed satisfaction, engagement, and motivation with SIDRA, R-G-SIDRA, and RB-G-SIDRA, thus obtaining a final average assessment of 4.28, 4.61, and 4.47 out of 5, respectively. Students perform better academically with gamified versus non-gamified audience response systems. Findings can be used to build a gamified adaptive learning system.

Use of deep learning for structural analysis of computer tomography images of soil samples.

Soil samples from several European countries were scanned using medical computer tomography (CT) device and are now available as CT images. The analysis of these samples was carried out using deep learning methods. For this purpose, a VGG16 network was trained with the CT images (X). For the annotation (y) a new method for automated annotation, 'surrogate' learning, was introduced. The generated neural networks (NNs) were subjected to a detailed analysis. Among other things, transfer learning was used to check whether the NN can also be trained to other y-values. Visually, the NN was verified using a gradient-based class activation mapping (grad-CAM) algorithm. These analyses showed that the NN was able to generalize, i.e. to capture the spatial structure of the soil sample. Possible applications of the models are discussed.

Unveiling the age and origin of biogenic aggregates produced by earthworm species with their NIRS fingerprint in a subalpine meadow of Central Pyrenees.

In this study the near-infrared reflectance (NIR) spectra signals (750-2,500 nm) of soil samples was compared with the NIR signals of the biogenic aggregates produced in the lab by three earthworm species, i.e., Aporrectodea rosea (Savigny 1826), Lumbricus friendi Cognetti, 1904 and Prosellodrilus pyrenaicus (Cognetti, 1904) from subalpine meadows in the Central Pyrenees. NIR spectral signatures of biogenic aggregates, root-aggregates, and non-aggregated soil were obtained together with soil carbon (C), nitrogen (N), [Formula: see text] and [Formula: see text] determinations. The concentrations of C, N and C:N ratio in the three types of soil aggregates identified were not statistically significant (ANOVA, p>0.05) although non-macroaggregated soil had slightly higher C concentrations (66.3 g kg-1 dry soil) than biogenic aggregates (earthworm- and root-aggregates, 64.9 and 63.5 g kg-1 dry soil, respectively), while concentrations of [Formula: see text] and [Formula: see text] were highest in the root-attached aggregates (3.3 and 0.31 mg kg dry soil-1). Total earthworm density and biomass in the sampled area was 137.6 ind. m-2, and 55.2 g fresh weight m-2, respectively. The biomass of aggregates attached to roots and non-macroaggregated soil was 122.3 and 134.8 g m-2, respectively, while biomass of free (particulate) organic matter and invertebrate biogenic aggregates was 62.9 and 41.7 g m-2, respectively. Multivariate analysis of NIR spectra signals of field aggregates separated root aggregates with high concentrations of [Formula: see text] and [Formula: see text] (41.5% of explained variance, axis I) from those biogenic aggregates, including root aggregates, with large concentrations of C and high C:N ratio (21.6% of total variability, axis II). Partial Least Square (PLS) regressions were used to compare NIR spectral signals of samples (casts and soil) and develop calibration equations relating these spectral data to those data obtained for chemical variables in the lab. After a derivatization process, the NIR spectra of field aggregates were projected onto the PLS factorial plane of the NIR spectra from the lab incubation. The projection of the NIR spectral signals onto the PLSR models for C, N, [Formula: see text] and [Formula: see text] from casts produced and incubated in the lab allowed us to identify the species and the age of the field biogenic aggregates. Our hypothesis was to test whether field aggregates would match or be in the vicinity of the NIR signals that corresponded to a certain species and the age of the depositions produced in the lab. A NIRS biogenic background noise (BBN) is present in the soil as a result of earthworm activity. This study provides insights on how to analyse the role of these organisms in important ecological processes of soil macro-aggregation and associated organic matter dynamics by means of analyzing the BBN in the soil matrix.

Hierarchical drivers of soil microbial community structure variability in "Monte Perdido" Massif (Central Pyrenees).

Microbial activity is highly dependent on climatic factors (moisture and temperature) and edaphic characteristics in temperate ecosystems. Moreover, soil microbial community composition in high mountain areas is less known when compared to plant communities. In this study we investigated the soil microbial community from a functional perspective using PLFA (phospholipid fatty acid) methods in the four aspects of four summits (2,242 - 3,012 m above sea level) in the Spanish Central Pyrenees. Soil organic carbon (C), microbial biomass and nutrient dynamics ([Formula: see text] + [Formula: see text], N mineralization and nitrification potential) were also determined. Microbial biomass C was highest in the lowermost summit and decreased by approximately 50, 14 and 12% with increasing altitude. In each summit soil [Formula: see text] and [Formula: see text] concentrations differed significantly among summits and aspects. Soil nitrification potential varied significantly between the factors summit and aspects, e.g., southerly vs. northerly, easterly vs. westerly aspects. Gram negative bacteria and Actinobacteria functional groups dominated the microbial community, with almost 40% of the total PLFA. Non-metric multidimensional scale (NMS) analysis showed that most of the PLFA functional groups were present in all summits and aspects, although with specific biomarkers. A high abundance of biomarkers 16:1ω9c and 16:0 2OH (gram negative bacteria) were obtained in the lowermost summit, while the biomarkers 16.1ω7cDMA (anaerobes) and 19:3ω6c (Eukaryote) were only found in the uppermost summit. Linear mixed model (lmm) analysis was used with summit as fixed effect and aspect as random effect. In general, our results demonstrate a fundamental role for environment, principally moisture, temperature and organic matter in explaining the pattern observed for soil PLFA biomarkers. Under a global change scenario, we need to shed light on the relationships between soil microbial functional groups and soil nutrient-related variables in order to identify the associated patterns of decomposition rates and soil processes driven by microbial communities in mountain areas. The results could thus be used in global predictive models on climate change impact on C or N cycles in these environments.

Cloning and expression of synthetic genes encoding native, hybrid- and bacteriocin-derived chimeras from mature class IIa bacteriocins, by Pichia pastoris (syn. Komagataella spp.).

In this work, synthetic genes designed from (a), the native amino acid sequence of the class IIa bacteriocins enterocin HF (EntHF) and enterocin CRL35 (EntCRL35), (b) from hybrid bacteriocins derived from fusion of enterocin A (EntA) to itself and to EntHF and EntCRL35 through a tri-glycine peptide linker, and (c) from bacteriocin-derived chimeras devised from fusion of the N-terminal region of EntA and enterocin P (EntP) to the C-terminal end of EntHF and EntCRL35, were cloned in plasmid pPICZαA for expression by P. pastoris X-33. Synthetic genes encoding EntHF and EntCRL35 were also cloned in plasmid pP-αhSUMO3 for expression of the hSUMO3-fused bacteriocins by P. pastoris. Only recombinant P. pastoris expressing the bacteriocin-derived chimeras displayed a direct antimicrobial activity whereas P. pastoris X-33, producer of EntP::EntHF, showed the highest antimicrobial activity in their supernatants and in the multi-step chromatographic purified fractions. The MRM-ESI-LC-MS/MS (QTRAP) analysis of purified fractions from P. pastoris producers of hybrid- and bacteriocin-derived chimeras, permitted detection in the samples of peptides with the expected molecular mass of the bacteriocins produced. The antimicrobial activity of the EntP::EntHF chimera compared to that of the synthetic EntP::EntHF peptide, suggest that the biologically-produced bacteriocin-derived chimera shows a higher specific antimicrobial activity than its synthetic counterpart against different Listeria strains, including L. monocytogenes. More important, the N-terminal region of EntA and EntP seems to drive the production, processing and secretion of hybrid- and bacteriocin-derived chimeras, by P. pastoris X-33.

Identification of the co-existence of low total organic carbon contents and low pH values in agricultural soil in north-central Europe using hot spot analysis based on GEMAS project data.

Total organic carbon (TOC) contents in agricultural soil are presently receiving increased attention, not only because of their relationship to soil fertility, but also due to the sequestration of organic carbon in soil to reduce carbon dioxide emissions. In this research, the spatial patterns of TOC and its relationship with pH at the European scale were studied using hot spot analysis based on the agricultural soil results of the Geochemical Mapping of Agricultural Soil (GEMAS) project. The hot and cold spot maps revealed the overall spatial patterns showing a negative correlation between TOC contents and pH values in European agricultural soil. High TOC contents accompanying low pH values in the north-eastern part of Europe (e.g., Fennoscandia), and low TOC with high pH values in the southern part (e.g., Spain, Italy, Balkan countries). A special feature of co-existence of comparatively low TOC contents and low pH values in north-central Europe was also identified on hot and cold spot analysis maps. It has been found that these patterns are strongly related to the high concentration of SiO2 (quartz) in the coarse-textured glacial sediments in north-central Europe. The hot spot analysis was effective, therefore, in highlighting the spatial patterns of TOC in European agricultural soil and helpful to identify hidden patterns.

Photochemical, thermal, biological and long-term degradation of celecoxib in river water. Degradation products and adsorption to sediment.

Celecoxib is an anti-inflammatory drug with antibacterial activity whose fate in surface water is unknown. Thus, some assays have been conducted under forced biological, photochemical and thermal conditions, and non-forced conditions, to establish its persistence and degradation products in river water. The results suggest that celecoxib dissolved in river water is not biologically degraded while it is minimally altered after its exposure to sunlight or high temperature (70°C). Only the irradiation at 254nm promotes its complete degradation. Celecoxib is degraded about 3%, in 36 weeks, when water was kept at room temperature and the exposure to sunlight was partially limited as it happens inside a body of water. Residues were monitored by ultra-pressure liquid chromatography/quadrupole time-of-flight/mass spectrometry after solid-phase extraction; eleven degradation products were detected and the structures of nine of them were unequivocally proposed from the molecular formulae and fragmentation observed in high-resolution tandem mass spectra. The long-term transformation products under non-forced conditions were 4-[5-(4-methylphenyl)-3-(trifluoromethyl)-1H-pyrazol-1-yl]benzenesulfonic acid, 4-[1-(4-sulfoaminephenyl)-3-(trifluoromethyl)-1H-pyrazol-5-yl]benzoic acid and a hydroxylated derivative. The degradation over time in presence of sediment was monitored, being slightly higher, about 4%. The adsorption equilibrium constants of celecoxib and degradation products on river sediment were estimated.

Forced and long-term degradation assays of tenoxicam, piroxicam and meloxicam in river water. Degradation products and adsorption to sediment.

The fate of the pharmaceutical drugs tenoxicam, piroxicam and meloxicam in river water is evaluated here for first time. So, biological, photochemical and thermal degradation assays have been conducted to estimate their degradation rates and know their degradation products. Results indicated that the direct sunlight irradiation, without any protection, promoted a fast degradation of the oxicams while the chemical reactions in solution were less important. The biological degradation in water was negligible except for tenoxicam in whose case its influence was scarce. When the exposition of river water to sunlight was partially limited and kept under the natural day-night cycle, as occurs inside a body of water, tenoxicam, piroxicam and meloxicam (at 2 µg L-1) were detected during a period of 15, 27 and 45 days, respectively. Residues were monitored by ultra-pressure liquid chromatography/quadrupole time-of-flight/mass spectrometry after solid-phase extraction and several degradation products were found (10 for tenoxicam, 9 for piroxicam and 7 for meloxicam) and monitored over time. Their structures were proposed from the molecular formulae and fragmentation observed in high-resolution tandem mass spectra; the nature of the transformation products found in the long-term resulted to be very variable for each oxicam. Furthermore, the degradation in presence of river sediment was also monitored over time, with some differences being noted; the adsorption coefficients of the compounds on sediment were calculated, meloxicam exhibited a higher sorption capacity. The ecotoxicity of the different compounds in aquatic ecosystems was predicted, too.

Degradation of indomethacin in river water under stress and non-stress laboratory conditions: degradation products, long-term evolution and adsorption to sediment.

The pharmaceutical compound indomethacin is not totally removed in wastewater treatment plants, whose effluents flow into aquatic environments; concentrations in the 0.1-100ng/L range are commonly found in surface waters, and its fate is unknown. Here, biological, photochemical and thermal degradation assays were conducted under stress and non-stress conditions to estimate its degradation rate in river water and establish its degradation products over time. The results revealed that direct sunlight irradiation promoted the complete degradation of indomethacin (2µg/L) in less than 6hr, but indomethacin was detected over a period of 4months when water was kept under the natural day-night cycle and the exposure to sunlight was partially limited, as occurs inside a body of water. The biological degradation in water was negligible, while the hydrolysis at pH7.8 was slow. Residues were monitored by ultra-pressure liquid chromatography/quadrupole time-of-flight/mass spectrometry after solid-phase extraction, and six degradation products were found; their structures were proposed based on the molecular formulae and fragmentation observed in high-resolution tandem mass spectra. 4-Chlorobenzoic and 2-acetamido-5-methoxybenzoic acids were the long-term transformation products, persisting for at least 30weeks in water kept under non-stress conditions. Furthermore, the degradation in the presence of sediment was also monitored over time, with some differences being noted. The adsorption coefficients of indomethacin and degradation products on river sediment were calculated; long-term degradation products did not have significant adsorption to sediment.