We investigated the effects of solvent composition, acidity, and temperature on the dediazoniation of 4‐methylbenzenediazonium (4MBD) ions in EtOH/H2O mixtures by employing a combination of ...spectrometric and chromatographic techniques. First‐order behavior is found in all solvent composition ranges. HPLC Analyses of the reaction mixtures indicate that three main dediazoniation products are formed depending on the particular experimental conditions. These are 4‐cresol (ArOH), 4‐phenetole (ArOEt), and toluene (ArH). At acidities (defined as −log HCl)<2, the main dediazoniation products are the substitution products ArOH and ArOEt but upon decreasing the acidity, the reduction product ArH becomes predominant at the expense of ArOH and ArOEt, indicating that a turnover in the reaction mechanism takes place under acidic conditions. At any given EtOH content, the plot of kobs values against acidity is S‐shaped, the inflexion point depending upon the EtOH concentration and the temperature. Similar S‐shaped variations are found when plotting the dediazoniation–product distribution against the acidity. The acid dependence of the switch between the homolytic and heterolytic mechanisms suggests that the homolytic dediazoniation proceeds via transient diazo ethers, and this complex kinetic behavior can be rationalized by assuming two competitive mechanisms: i) the spontaneous heterolytic dediazoniation of 4MBD, and ii) an O‐coupling mechanism in which the EtOH molecules capture ArN$\rm{{_{2}^{+}}}$ to yield a highly unstable (Z)‐adduct which undergoes homolytic fragmentation initiating a radical process (Scheme). Analyses of the effects of temperature on the equilibrium constant for the formation of the diazo ether and on the rate of splitting of the diazo ether allowed the estimation of relevant thermodynamic parameters for the formation of diazo ethers derived from methylbenzenediazonium ions under acidic conditions.
To compare the atherosclerosis disease burden between ankylosing spondylitis (AS) and non-radiographic (nr) axial spondyloarthritis (axSpA) and establish a model that allows to identify ...high-cardiovascular (CV) risk in axial spondyloarthritis patients.
Cross-sectional study from the AtheSpAin cohort, a Spanish multicenter cohort aimed to study atherosclerosis in axSpA. Carotid ultrasound (US) was performed to determine the carotid intima-media wall thickness (cIMT) and detect the presence of carotid plaques. The European cardiovascular disease risk assessment model, the Systematic COronary Risk Evaluation (SCORE), was also applied.
A set of 639 patients with AS and 167 patients with nr-axSpA without history of CV events were recruited. AS patients were older showing more CV risk factors and higher values of C reactive protein and erythrocyte sedimentation rate (ESR) than those with nr-axSpA. However, no difference in the prevalence of carotid plaques or in the cIMT was found between both groups in the adjusted analysis. The percentage of patients reclassified from the low and moderate CV risk categories to the very high-risk category due to the presence of carotid plaques was comparable in AS and nr-axSpA (10.7% versus 10.1% and 40.5% versus 45.5%, respectively). A model containing age, BASFI and ESR applied to moderate risk axSpA patients identified 41% of these patients as having very high-risk patients with high specificity (88%).
The atherosclerosis burden is similar in nr-axSpA and AS. As occurred for AS, more than 40% of axSpA patients included in the category of moderate CV risk according to the SCORE are reclassified into very high risk after carotid US, and a clinically relevant proportion of them can be detected by applying a model containing age, BASFI and ESR.
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Improving the mechanical properties of a clayey soil is one of the best options to avoid future structural failures in buildings and is cheaper than replacing all the material. Therefore, this ...article proposes the use of recycled glass and fan shells as reinforcement materials. This article presents an experimental study to evaluate the mechanical properties of a pure and mixed soil. The clay soil was mixed with 7% of glass (PV) and with 3%, 6%, 10%, 12% and 15% of Fan Shells (PCA) duly crushed and passed through sieve #100. Tests of sieve granulometry, sedimentation granulometry, Atterberg limits, modified proctor and drained consolidated direct cut were performed. This allowed comparing all the data obtained and defining the optimal percentage of the mixture in which the clay improves its mechanical properties. According to the tests carried out, the proportion that has 7% glass and 6% Fan Shells has better results because there is an improvement in its dry density from 1,784 g / cm3 to 1,847 g / cm3, its moisture content increases from 9.4% to 12.1%. In addition, its friction angle improves from 28.9 ° to 32 ° and cohesion from 0.05 kg / cm2 to 0.1 kg / cm2. These results verify that the properties of the clay soil are improved.
Interstitial lung disease (ILD) is one of the most serious complications of rheumatoid arthritis (RA). In the present study, we aimed to assess the efficacy of abatacept (ABA) in patients with ILD ...associated to RA.
National multicenter, non-controlled, open-label registry study of RA patients with ILD treated with ABA.
63 patients (36 women) with RA-associated ILD undergoing ABA therapy were studied. The mean ± standard deviation age at the time of the study was 63.2 ± 9.8 years. The median duration of RA and ILD from diagnosis were 6.8 and 1 year, respectively. RA was seropositive in 55 patients (87.3%). In 15 (23.8%) of 63 patients the development of ILD was closely related to the administration of synthetic or biologic disease modifying anti-rheumatic drugs. After a follow-up of 9.4 ± 3.2 months, two-thirds of patients remained stable whereas one-quarter experienced improvement in the Modified Medical Research Council scale. At that time forced vital capacity remained stable in almost two-thirds of patents and improved in one out of five patients assessed. Also, diffusing capacity of the lung for carbon monoxide remained stable in almost two-thirds and showed improvement in a quarter of the patients assessed. At 12 months, 50% of the 22 patients in whom chest HRCT scan was performed due persistence of respiratory symptoms showed stabilization, 8 (36.4%) improvement and 3 worsening of the HRCT scan pattern. Eleven of 63 patients had to discontinue ABA, mainly due to adverse events.
ABA appears to be an effective in RA-associated ILD.
To determine the potential impact of sex-specific disease-related characteristics on cardiovascular (CV) disease in axial spondyloarthritis (axSpA).
Cross-sectional study of the Spanish AtheSpAin ...cohort to study CV disease in axSpA. Data on carotid ultrasound and CV disease and disease-related features were collected.
611 men and 301 women were recruited. Classic CV risk factors were significantly less prevalent in women, who also showed a lower frequency of carotid plaques (p = 0.001), lower carotid intima-media thickness (IMT) values (p<0.001) and CV events (p = 0.008). However, after adjustment for classic CV risk factors, only the differences with respect to carotid IMT remained statistically significant. Women showed higher ESR at diagnosis (p = 0.038), and more active disease (ASDAS, p = 0.012, and BASDAI, p<0.001). They had shorter disease duration (p<0.001), lower prevalence of psoriasis (p = 0.008), less structural damage (mSASSS, p<0.001), and less mobility limitation (BASMI, p = 0.033). To establish whether these findings could lead to sex differences in CV disease burden, we compared the prevalence of carotid plaques in men and women with the same level of CV risk stratified according to the Systematic Coronary Risk Evaluation (SCORE). Men included in the low-moderate CV risk SCORE category had more carotid plaques (p = 0.050), along with longer disease duration (p = 0.004), higher mSASSS (p = 0.001) and psoriasis (p = 0.023). In contrast, in the high-very high-risk SCORE category, carotid plaques were observed more frequently in women (p = 0.028), who were characterized as having worse BASFI (p = 0.011), BASDAI (p<0.001) and ASDAS (p = 0.027).
Disease-related features may influence the expression of atherosclerosis in patients with axSpA. This may be especially applicable to women at high CV risk, characterized by greater disease severity and more severe subclinical atherosclerosis than men, suggesting a stronger interaction between disease activity and atherosclerosis in women with axSpA.
A series of chromium oxides (Cr2O3) nanoparticles supported on different carbonaceous material, namely: graphene, graphene oxide (GO) and graphite, were synthetized by precipitation of the salt ...precursors with precipitant (ammonia) and the subsequent thermal treatment. The catalytic activity of these composites and the Cr2O3 nanoparticles have been analysed by Koutecky-Levich (KL) and rotating ring-disc electrode methods and the results have been discussed following a model proposed here, which considers the O2 electrosorption as the rate determining step. Among them, graphite and graphene based composites have better catalytic activities and their behaviours agree with the proposed treatment: logarithm dependent of the intercept and nondependent slopes values of the KL plots with the potential. Cr2O3-graphite shows a mechanism interchanging 4 e-, which has been attributed to a graphite- Cr2O3 nanoparticles interaction. Besides, Cr2O3-graphite-based electrodes have been tested as cathode in a Zn/PVA-KOH/air battery, confirming its good properties to be applied as positive electrode in metal-air batteries.
A sustainable route to obtain graphene oxide (GO) and reduced graphene oxide (rGO) with highly competitive properties through the utilization of graphite recycled from spent vehicle's lithium-ion ...batteries is described. As compared with previous works, our precursor material is representative of a larger-scale recycling procedure, involves the processing of both cathodic and anodic materials, and concerns a larger number of batteries operated in diverse conditions. The morphology, chemical features, structure, and conductivity of the samples have been thoroughly investigated. Results obtained from complementary characterization techniques reveal the correct formation of GO and rGO samples from the recycled graphites. Electrical measurements show that the conductivity of our GO and rGO samples are very similar or even larger than those reported for samples obtained from high-purity natural graphite. These results indicate that our strategy is able to produce good-quality GOs and rGOs with potential applications in different fields, contributing to the circular economy and the recyclability of discarded wastes.
•GO and rGO samples were prepared from waste precursor material.•Highly competitive GO and rGO samples were obtained.•A deep characterization of all obtained GO and rGO samples was carried out.•Electrical characterization shows a high conductivity of the final samples.
Asthma is the most common chronic disease in children globally. The Global Asthma Network (GAN) Phase I study aimed to determine if the worldwide burden of asthma symptoms is changing.
This updated ...cross-sectional study used the same methods as the International study of Asthma and Allergies in Childhood (ISAAC) Phase III. Asthma symptoms were assessed from centres that completed GAN Phase I and ISAAC Phase I (1993–95), ISAAC Phase III (2001–03), or both. We included individuals from two age groups (children aged 6–7 years and adolescents aged 13–14 years) who self-completed written questionnaires at school. We estimated the 10-year rate of change in prevalence of current wheeze, severe asthma symptoms, ever having asthma, exercise wheeze, and night cough (defined by core questions in the questionnaire) for each centre, and we estimated trends across world regions and income levels using mixed-effects linear regression models with region and country income level as confounders.
Overall, 119 795 participants from 27 centres in 14 countries were included: 74 361 adolescents (response rate 90%) and 45 434 children (response rate 79%). About one in ten individuals of both age groups had wheeze in the preceding year, of whom almost half had severe symptoms. Most centres showed a change in prevalence of 2 SE or more between ISAAC Phase III to GAN Phase I. Over the 27-year period (1993–2020), adolescents showed a significant decrease in percentage point prevalence per decade in severe asthma symptoms (–0·37, 95% CI –0·69 to –0·04) and an increase in ever having asthma (1·25, 0·67 to 1·83) and night cough (4·25, 3·06 to 5·44), which was also found in children (3·21, 1·80 to 4·62). The prevalence of current wheeze decreased in low-income countries (–1·37, –2·47 to –0·27, in children and –1·67, –2·70 to –0·64, in adolescents) and increased in lower-middle-income countries (1·99, 0·33 to 3·66, in children and 1·69, 0·13 to 3·25, in adolescents), but it was stable in upper-middle-income and high-income countries.
Trends in prevalence and severity of asthma symptoms over the past three decades varied by age group, country income, region, and centre. The high worldwide burden of severe asthma symptoms would be mitigated by enabling access to effective therapies for asthma.
International Union Against Tuberculosis and Lung Disease, Boehringer Ingelheim New Zealand, AstraZeneca Educational Grant, National Institute for Health Research, UK Medical Research Council, European Research Council, and Instituto de Salud Carlos III.
Resumen Introducción La persistencia de ductus arterioso (PDA), se considera un factor de riesgo para enterocolitis necrosante (ECN) y otras complicaciones digestivas en prematuros. El objetivo del ...presente trabajo es analizar si existe un mayor riesgo de cirugía abdominal y morbimortalidad asociada en prematuros que precisaron tratamiento debido a una PDA significativa. Metodología Estudio observacional, analítico y retrospectivo incluyendo prematuros menores de 37 semanas de gestación, con diagnóstico de PDA en los últimos 10 años. En función del tratamiento recibido, los pacientes fueron divididos en 3 grupos: tratamiento médico (A), tratamiento médico y quirúrgico (B) y sin tratamiento (C). Se analizaron variables pre y perinatales, incidencia de complicaciones digestivas (ECN y necesidad de cirugía por este motivo) y mortalidad global. Resultados Se obtuvo una muestra de 144 pacientes: 91 se asignaron al grupo A, 16 al B y 37 al C. La edad gestacional media por grupos fue de 28, 26,7 y 30,1 semanas. El peso medio al nacer fue de 1.083,9, 909,3 y 1471,2 g, respectivamente. En cuanto a la incidencia de ECN, se encontraron un total de 21, 5 y 5 casos en cada grupo, precisando cirugía abdominal un 43, 60 y 35%, respectivamente. La mortalidad por grupos fue del 12, 19 y 3%. Conclusiones Los pacientes que precisaron tratamiento por PDA, presentaron una mayor incidencia de complicaciones digestivas y una mayor mortalidad que los pacientes no tratados, sin embargo, no encontramos diferencias estadísticamente significativas. En el grupo de pacientes que requirieron tratamiento, la menor edad gestacional y peso al nacer, podrían explicar el incremento de la morbimortalidad encontrada en estos pacientes.
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