Boltzmann showed that in spite of momentum and energy redistribution through collisions, a rarefied gas confined in a isotropic harmonic trapping potential does not reach equilibrium; it evolves ...instead into a breathing mode where density, velocity, and temperature oscillate. This counterintuitive prediction is upheld by cold atoms experiments. Yet, are the breathers eternal solutions of the dynamics even in an idealized and isolated system? We show by a combination of hydrodynamic arguments and molecular dynamics simulations that an original dissipative mechanism is at work, where the minute and often neglected bulk viscosity eventually thermalizes the system, which thus reaches equilibrium.
A thermodynamic study of Glycerol Steam Reforming (GSR) for hydrogen production with in situ carbon dioxide and hydrogen (reaction products) simultaneous removal was performed. The sorption-enhanced ...membrane reactor (SEMR) was divided into multiple sub-Gibbs reactors and the Gibbs free energy minimization method was employed. The effects of temperature (600-800 K), molar water-to-glycerol feed ratio (WGFR) (3-9), pressure (1-5 atm) and fraction of hydrogen and carbon dioxide removal (f, 0-0.99) on the GSR process were target of investigation. A hydrogen yield (total moles of hydrogen produced/mole of reacted glycerol) very close to the stoichiometric value of 7 was obtained at 700 K, WGFR of 9, 1 atm and for f sub(CO) sub(2) = 0.99 and f sub(H) sub(2) = 0.80. This corresponds to an enhancement of 217%, 47% and 22% in terms of hydrogen yield comparatively to the traditional reactor (TR), sorption-enhanced reactor (SER) with carbon dioxide capture (f sub(CO) sub(2) = 0.99) and membrane reactor (MR) with hydrogen separation (f sub(H) sub(2) = 0.80); respectively. In terms of coke, its formation was only observed under WGFRs below the stoichiometric value of 3.
The one‐pot synthesis of λ4‐dibenzothiophen‐5‐imino‐N‐dibenzothiophenium triflate (1) in multigram scale is reported. This compound reacts with Rh2(esp)2 ...(esp=α,α,α′,α′‐tetramethyl‐1,3‐benzenedipropionic acid) generating a Rh‐coordinated sulfonitrene species, which is able to transfer the electrophilic nitrene moiety to olefins. When indenes are used as substrates, isoquinolines are obtained in good yields. We assumed that after formation of the corresponding N‐sulfonio aziridine, a ring expansion occurs via selective C−C bond cleavage and concomitant elimination of dibenzothiophene. Unexpectedly, a similar protocol transforms 1‐arylcyclobutenes into 1‐cyano‐1‐arylcyclopropanes. Our calculations indicate that aziridination is not favored in this case; instead, sulfilimine‐substituted cyclobutyl carbocations are initially formed, and these evolve to the isolated cyclopropanes via ring contraction. Both procedures are operationally simple, tolerate a range of functional groups, including oxidation‐sensitive alcohols and aldehydes, and enable the convenient preparation of valuable 15N‐labelled products. These results demonstrate the potential of 1 to provide alternative pathways for the selective transfer of N‐atoms in organic molecules.
Under rhodium catalysis N‐sulfonio(sulfilimines) act as sulfonitrene precursors. Reaction of such species with indenes presumably delivers N‐sulfonio aziridines, which evolve to isoquinolines via electrocyclic ring expansion. Contrarily, 1‐arycyclobutenes are transformed into 1‐cyano‐1‐arylcyclopropanes via ring contraction.
Studying soil hydrological processes requires the determination of soil hydraulic parameters whose assessment using traditional methods is expensive and time-consuming. A specific method, Beerkan ...estimation of soil transfer parameters referred to as BEST was developed to facilitate the determination of both the water retention curve, theta(h), and the hydraulic conductivity curve, K(theta), defined by their shape and scale parameters. BEST estimates shape parameters from particle-size distribution analysis and scale parameters from infiltration experiments at null pressure head. Saturated water content is measured directly at the end of infiltration. Hydraulic conductivity and water pressure scale parameters are calculated from the steady-state infiltration rate and prior estimation of sorptivity (S). This is provided by fitting transient infiltration data on the classical two-term equations with values from zero to a maximum corresponding to null hydraulic conductivity and using a data subset for which the two-term infiltration equations are verified as valid. BEST was compared with other fitting methods to estimate sorptivity and hydraulic conductivity from infiltration modeling data on the basis of the same infiltration equations for three contrasting soils: agricultural soil, sandy soil, and a coarser fluvioglacial deposit. The other methods failed sometimes to model accurately experimental data and to provide values in agreement with physical principles of water infiltration (negative values for hydraulic conductivity, too high steady-state infiltration rate). None of these anomalies was encountered when modeling cumulative infiltration with BEST. BEST appears to be a promising, easy, robust, and inexpensive way of characterizing the hydraulic behavior of soil.
Hydroxytyrosol (HT) is a bioactive olive oil phenol with beneficial effects in a number of pathological situations. We have previously demonstrated that an HT-enriched diet could serve as a ...beneficial therapeutic approach to attenuate ischemic-stroke-associated damage in mice. Our exploratory pilot study examined this effect in humans. Particularly, a nutritional supplement containing 15 mg of HT/day was administered to patients 24 h after the onset of stroke, for 45 days. Biochemical and oxidative-stress-related parameters, blood pressure levels, serum proteome, and neurological and functional outcomes were evaluated at 45 and 90 days and compared to a control group. The main findings were that the daily administration of HT after stroke could: (i) favor the decrease in the percentage of glycated hemoglobin and diastolic blood pressure, (ii) control the increase in nitric oxide and exert a plausible protective effect in oxidative stress, (iii) modulate the evolution of the serum proteome and, particularly, the expression of apolipoproteins, and (iv) be beneficial for certain neurological and functional outcomes. Although a larger trial is necessary, this study suggests that HT could be a beneficial nutritional complement in the management of human stroke.
The present work compared 2 culture methods and the combinations of pre-enrichment and enrichment culture methods with PCR assays buffered peptone water-PCR and tetrathionate-PCR or modified ...semisolid Rappaport-Vassiliadis (MSRV)-PCR for motile and nonmotile Salmonella strain detection using artificially contaminated poultry feces. The specificity and positive predictive values were equal to one in both culture methods. Specificity and positive predictive values, accuracy, sensitivity, and negative predictive values were higher for motile than nonmotile Salmonella strains in culture methods. Only Salmonella enterica serovar Gallinarum was detected by the MSRV method with low accuracy, sensitivity, and negative predictive value. The detection level of motile strains was 2 ×10(0) to 22 × 10(2) cfu per 25 g for these methods, whereas it was 6.9 × 10(2) cfu per 25 g in culture methods for Salmonella Gallinarum. Extending the incubation time of the enrichment medium to 6 d in the TT method did not improve the isolation rates. In general, all selective plating media did not show any statistical differences in the parameters of performance studied. On the other hand, accuracy and sensitivity values were higher in MSRV-PCR and tetrathionate-PCR methods than in the buffered peptone water-PCR method. Specificity and positive predictive values were equal to one in most of the cases. In terms of detection limits, motile Salmonella strains were recovered from 5 × 10(0) cfu per 25 g in MSRV-PCR and tetrathionate-PCR methods, whereas the detection limit was better for nonmotile Salmonella in MSRV-PCR methods than in the tetrathionate-PCR method. Kappa coefficients showed that there was a very good agreement between tetrathionate and MSRV methods for motile Salmonella strains, whereas these methods did not show any concordance for nonmotile Salmonella strains. When buffered peptone water-PCR was compared with both tetrathionate-PCR and MSRV-PCR, agreement was poor for motile Salmonella strains and slight to fair for nonmotile Salmonella strains. The difference in isolation rate obtained with the methods used for motile and nonmotile Salmonella strains must be taken into account when a poultry fecal sample is considered negative for the presence of Salmonella.
► MAE, MSPD, SLE and QuEChERS were optimized and tested for the extraction of pesticides in grapes. ► MAE, MSPD and SLE were optimized by experimental design. ► Linearity, LODs and LOQs, recoveries ...and precision of the four methods were compared. ► The methods were carried out for the analysis of spiked and real samples. ► MAE demonstrated to be more sensitive and faster than the other three methods.
Four different methods for simultaneous extraction of vinclozolin, dichlofluanid, penconazole, captan, quinoxyfen, fluquinconazol, boscalid and pyraclostrobin from grapes were optimized and further tested. Microwave assisted extraction (MAE), matrix solid-phase dispersion (MSPD), solid–liquid extraction (SLE) and QuEChERS were compared in terms of their limits of detection and quantification and recoveries. For MAE, MSPD and ethyl acetate extraction, the optimal conditions were optimized by using experimental designs. The analysis was performed using gas chromatography–mass spectrometry in the selected ion monitoring mode (GC–MS, SIM). The proposed methods showed good sensitivity, limits of quantification were lower than MRLs and precision (expressed as relative standard deviation) ranged from 2.9 to 11.1%. The recoveries obtained from MAE, MSPD, SLE and QuEChERS were in the range 78–100%, 66–102%, 58–88% and 68–96%, respectively. In addition, the four methods were compared in two ways: by means of calibration curves obtained with 10 fortified samples in the studied range of concentrations and by the application of statistical tests such as Levene's test (to study variance homogeneity), ANOVA and Tukey's test (in case of Levene's test was satisfactory) for the assessment of the information obtained in the analysis of real samples. Both ways of comparison led to the same results: no differences between the four methods for the extraction of vinclozolin, dichofluanid, quinoxyfen, fluquinconazol and pyraclostrobin were found. However, there were differences for the analysis of captan, boscalid and penconazole.
Inflammatory bowel disease (IBD) is a chronic gastrointestinal condition. While inflammatory biomarkers are valuable for diagnosing and monitoring the disease, their correlation with patients' ...quality of life (QoL) is not well-established.
This study aims to investigate the correlations between inflammatory biomarkers and the quality of life (QoL) variables of individuals diagnosed with IBD in clinical remission.
The sample of this cross-sectional study included 74 patients (80% women; 45 ± 11 years old) diagnosed with IBD. Outcome variables included faecal calprotectin (FC), C-reactive protein (CRP), cortisol levels from hair samples, and anxiety and depression assessed using the Hospital Anxiety and Depression Scale (HADS-A and HADS-D, respectively), alongside QoL evaluated with the Inflammatory Bowel Disease Questionnaire 32 (IBDQ-32). Bivariate correlations were calculated using the Pearson correlation coefficient, and stepwise linear regression analyses were conducted to identify independent factors contributing to IBDQ-32 scores.
The IBDQ-32 did not significantly correlate with any biomarkers. However, it exhibited a large and statistically significant negative correlation with HADS-A (r = -0.651) and HADS-D (r = -0.611) scores (
< 0.001). Stepwise linear regression analyses indicated that HADS-A was a significant and independent predictor for IBDQ-32 scores (Adjusted R
= 0.41, β = -0.65,
< 0.001).
Inflammatory markers such as CRP, FC, or cortisol in hair do not play a decisive role in assessing the QoL of IBD patients. These findings emphasize the significance of considering psychological factors in evaluating and managing QoL in IBD patients in order to identify severity, suggesting that instruments like HADS should be integral to comprehensive patient assessments.
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