Destruction of first-order phase transition in a random-field Ising model

The phase transitions that occur in an infinite-range-interaction Ising ferromagnet in the presence of a double-Gaussian random magnetic field are analyzed. Such random fields are defined as a superposition of two Gaussian distributions, presenting the same width $\sigma$. Is is argued that this distribution is more appropriate for a theoretical description of real systems than its simpler particular cases, i.e., the bimodal ($\sigma=0$) and the single Gaussian distributions. It is shown that a low-temperature first-order phase transition may be destructed for increasing values of $\sigma$, similarly to what happens in the compound $Fe_{x}Mg_{1-x}Cl_{2}$, whose finite-temperature first-order phase transition is presumably destructed by an increase in the field randomness.Comment: 13 pages, 3 figure

Spectroscopic studies of ketones as a marker for patients with diabetes

Acetone in human breath has been established as a biomarker for diabetes. The application of UV spectroscopy for the study of biomedical compounds has been developed over recent years but is often limited by the lack of absolute data for calibration of the instrumentation. By measuring high resolution absolute VUV photoabsorption cross sections of acetone, we are able to provide calibration values at several wavelengths with special attention to 4.661 eV (266 nm). Results are compared with recent published data [C Wang, A Mbi, Meas. Sci. Technol., 2007, 18, 2731–2741]. The acetone spectrum is here revisited from a recent contribution [Nobre M, et al, Phys Chem Chem Phys, 2008 (in press)] where the absolute cross sectional values are obtained in the 3.7–10.8 eV energy region. Future medical units working in close link with synchrotron radiation facilities can make use of the VUV spectra wavelength region to trace acetone in diabetic patients

Rapidly progressive coronary aneurysm: a rare case of isolated coronary vasculitis with recurrent myocardial infarction

© 2022 The Authors. Published by Elsevier on behalf of the American College of Cardiology Foundation. This article is available under the Creative Commons CC-BY-NC-ND license and permits non-commercial use of the work as published, without adaptation or alteration provided the work is fully attributed.Isolated coronary arteritis without systemic involvement in adults is exceedingly rare. A 60-year-old patient developed recurrent non–ST-segment elevation myocardial infarctions for 1 year. After an initial coronary angiogram that was normal, serial angiograms showed de novo aneurysm formation. The patient responded favorably to corticosteroids, supporting the diagnosis of isolated coronary arteritis.info:eu-repo/semantics/publishedVersio

Sutureless bioprosthesis for aortic valve replacement: surgical and clinical outcomes

© 2022 The Authors. Journal of Cardiac Surgery published by Wiley Periodicals LLC. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.Background: Aortic valve stenosis is the most common adult valve disease in industrialized countries. The aging population and the increase in comorbidities urge the development of safer alternatives to the current surgical treatment. Sutureless bioprosthesis has shown promising results, especially in complex procedures and in patients requiring concomitant surgeries. Objectives: Assess the clinical and hemodynamic performance, safety, and durability of the Perceval® prosthetic valve. Methods: This single-center retrospective longitudinal cohort study collected data from all adult patients with aortic valve disease who underwent aortic valve replacement with a Perceval® prosthetic valve between February 2015 and October 2020. Of the 196 patients included (mean age 77.20 ± 5.08 years; 45.4% female; mean EuroSCORE II 2.91 ± 2.20%), the majority had aortic stenosis. Results: Overall mean cross-clamp and cardiopulmonary bypass times were 33.31 ± 14.09 min and 45.55 ± 19.04 min, respectively. Mean intensive care unit and hospital stay were 3.32 ± 3.24 days and 7.70 ± 5.82 days, respectively. Procedural success was 98.99%, as two explants occurred. Four valves were reimplanted due to intraoperative misplacement. Mean transvalvular gradients were 7.82 ± 3.62 mmHg. Pacemaker implantation occurred in 12.8% of patients, new-onset atrial fibrillation in 21.9% and renal replacement support was necessary for 3.1%. Early mortality was 2.0%. We report no structural valve deterioration, strokes, or endocarditis, and one successfully treated valve thrombosis. Conclusions: Our study confirms the excellent clinical and hemodynamic performance and safety of a truly sutureless aortic valve, up to a 5-year follow-up. These results were consistent in isolated and concomitant interventions, solidifying this device as a viable option for the treatment of isolated aortic valve disease.info:eu-repo/semantics/publishedVersio

Seleção de cultivares de arroz irrigado para solos salino-sódicos. II. Ensaios de campo

A field experiment in a saline-sodic soil of the irrigated perimeter of São Gonçalo-Sousa, PB, Brazil, was carried out with the objective to select cultivars of irrigated rice (Oryza sativa L.) for salt affected soils. A random block design with thirteen cultivars and three replications was adopted. Before the start of the experiment, 40 t/ha of gypsum were incorporated in the soil, and N, P2O5 and K2O were applied at the rate of 5O, 30 and 10 kg/ha, respectively. The cultivars under study showed significant yield differences at 0.01 probability level and a mean production of 6.12 t/ha was obtained for the cultivar IR 2058-78-1-3-2-3. Considering the high exchangeable sodium percentage and the fact that experimental plot has not been cultivated for many years, the results obtained show the viability of utilization and reclamation of such soils with gypsum and rice cultivars.Com o objetivo de selecionar, para solos afetados por sais, as cultivares de arroz (Oryza sativa L.) mais viáveis, montou-se um experimento em solo salino-sódico do Perímetro Irrigado de São  Gonçalo-Sousa, PB. O delineamento experimental adotado foi o de blocos ao acaso com treze cultivares e três repetições. Foram incorporadas 40 t/ha de gesso comercial antes do lançamento do experimento, e como adubação foram utilizados 50, 30 e 10 kg/ha de N, P2O5 e K20, respectivamente. As cultivares testadas mostraram diferenças significativas ao nível de 0,01 de probabilidade em relação à produtividade, destacando-se a cultivar IR 2058-78-1-3-2-3, com produção média de 6,12 t/ha. Considerando-se a alta percentagem de sódio trocável, e que o solo não vinha sendo cultivado há vários anos, os resultados obtidos mostram viabilidade de utilização e recuperação desses solos com o emprego de gesso e cultivares de arroz que melhor se comportaram

Multicritical Behavior in a Random-Field Ising Model under a Continuous-Field Probability Distribution

A random-field Ising model that is capable of exhibiting a rich variety of multicritical phenomena, as well as a smearing of such behavior, is investigated. The model consists of an infinite-range-interaction Ising ferromagnet in the presence of a triple-Gaussian random magnetic field, which is defined as a superposition of three Gaussian distributions with the same width $\sigma$, centered at H=0 and $H=\pm H_{0}$, with probabilities $p$ and $(1-p)/2$, respectively. Such a distribution is very general and recovers as limiting cases, the trimodal, bimodal, and Gaussian probability distributions.Comment: 25 pages, 21 figures, articl

SRC inhibition prevents P-cadherin mediated signaling and function in basal-like breast cancer cells

BACKGROUND: Basal-like breast cancer (BLBC) is a poor prognosis subgroup of triple-negative carcinomas that still lack specific target therapies and accurate biomarkers for treatment selection. P-cadherin is frequently overexpressed in these tumors, promoting cell invasion, stem cell activity and tumorigenesis by the activation of Src-Family kinase (SRC) signaling. Therefore, our aim was to evaluate if the treatment of BLBC cells with dasatinib, the FDA approved SRC inhibitor, would impact on P-cadherin induced tumor aggressive behavior. METHODS: P-cadherin and SRC expression was evaluated in a series of invasive Breast Cancer and contingency tables and chi-square tests were performed. Cell-cell adhesion measurements were performed by Atomic Force Microscopy, where frequency histograms and Gaussian curves were applied. 2D and 3D cell migration and invasion, proteases secretion and self-renew potential were evaluated in vitro. Student's t-tests were used to determine statistically significant differences. The cadherin/catenin complex interactions were evaluated by in situ proximity-ligation assay, and statistically significant results were determined by using Mann-Whitney test with a Bonferroni correction. In vivo xenograft mouse models were used to evaluate the impact of dasatinib on tumor growth and survival. ANOVA test was used to evaluate the differences in tumor size, considering a confidence interval of 95%. Survival curves were estimated by the Kaplan-Meier's method, using the log-rank test to assess significant differences for mice overall survival. RESULTS: Our data demonstrated that P-cadherin overexpression is significantly associated with SRC activation in breast cancer cells, which was also validated in a large series of primary tumor samples. SRC activity suppression with dasatinib significantly prevented the in vitro functional effects of P-cadherin overexpressing cells, as well as their in vivo tumorigenic and metastatic ability, by increasing mice overall survival. Mechanistically, SRC inhibition affects P-cadherin downstream signaling, rescues the E-cadherin/p120-catenin complex to the cell membrane, recovering cell-cell adhesion function. CONCLUSIONS: In conclusion our findings show that targeting P-cadherin/SRC signaling and functional activity may open novel therapeutic opportunities for highly aggressive and poor prognostic basal-like breast cancer.This work was funded by Laço Grant 2014, by FEDER - Fundo Europeu de Desenvolvimento Regional funds through the COMPETE 2020 - Operacional Programme for Competitiveness and Internationalisation (POCI), Portugal 2020, and by FCT - Fundação para a Ciência e a Tecnologia/ Ministério da Ciência, Tecnologia e Ensino Superior under the projects PTDC/SAU-GMG/120049/ 2010-FCOMP-01-0124-FEDER-021209, PEst-C/SAU/LA0003/2013, NORTE-01- 0145-FEDER-000029 and POCI-01-0145-FEDER-016390. FCT funded the research grants of ASR (SFRH/BPD/75705/2011), ARN (SFRH/BD/100380/2014), BS (SFRH/ BPD/104208/2014), AFV (SFRH/BPD/90303/2012), as well as JP with Programa IFCT 2013 (FCT Investigator). IPATIMUP integrates the i3S Research Unit, which is partially supported by FCT in the framework of the project “Institute for Research and Innovation in Health Sciences” (POCI-01-0145-FEDER-007274)

Role of omega-6 fatty acid metabolism in cardiac surgery postoperative bleeding risk

Copyright © 2022 The Authors. Published by Wolters Kluwer Health, Inc. on behalf of the Society of Critical Care Medicine. This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially without permission from the journal.Cardiac surgery is frequently associated with significant postoperative bleeding. Platelet-dysfunction is the main cardiopulmonary bypass (CPB)-induced hemostatic defect. Not only the number of platelets decreases, but also the remaining are functionally impaired. Although lipid metabolism is crucial for platelet function, little is known regarding platelet metabolic changes associated with CPB-dysfunction. Our aim is to explore possible contribution of metabolic perturbations for platelet dysfunction after cardiac surgery. Design: Prospective cohort study. Setting: Tertiary academic cardiothoracic-surgery ICU. Patients: Thirty-three patients submitted to elective surgical aortic valve replacement. Interventions: Samples from patients were collected at three time points (preoperative, 6- and 24-hr postoperative). Untargeted metabolic analysis using high-performance liquid chromatography-tandem mass spectrometry was performed to compare patients with significant postoperative bleeding with patients without hemorrhage. Principal component analyses, Wilcoxon matched-pairs signed-rank tests, adjusted to FDR, and pairwise comparison were used to identify pathways of interest. Enrichment and pathway metabolomic complemented the analyses. Measurements and main results: We identified a platelet-related signature based on an overrepresentation of changes in known fatty acid metabolism pathways involved in platelet function. We observed that arachidonic acid (AA) levels and other metabolites from the pathway were reduced at 6 and 24 hours, independently from antiagreggation therapy and platelet count. Concentrations of preoperative AA were inversely correlated with postoperative chest tube blood loss but were not correlated with platelet count in the preoperative, at 6 or at 24 hours. Patients with significant postoperative blood-loss had considerably lower values of AA and higher transfusion rates. Values of postoperative interleukin-6 were strongly correlated with AA variability. Conclusions and relevance: Our observations suggest that an inflammatory-related perturbation of AA metabolism is a signature of cardiac surgery with CPB and that preoperative levels of AA may be more relevant than platelet count to anticipate and prevent postoperative blood loss in patients submitted to cardiac surgery with CPB.info:eu-repo/semantics/publishedVersio

Tricritical Points in the Sherrington-Kirkpatrick Model in the Presence of Discrete Random Fields

The infinite-range-interaction Ising spin glass is considered in the presence of an external random magnetic field following a trimodal (three-peak) distribution. The model is studied through the replica method and phase diagrams are obtained within the replica-symmetry approximation. It is shown that the border of the ferromagnetic phase may present first-order phase transitions, as well as tricritical points at finite temperatures. Analogous to what happens for the Ising ferromagnet under a trimodal random field, it is verified that the first-order phase transitions are directly related to the dilution in the fields (represented by $p_{0}$). The ferromagnetic boundary at zero temperature also exhibits an interesting behavior: for $0<p_{0}<p_{0}^{*} \approx 0.30856$, a single tricritical point occurs, whereas if $p_{0}>p_{0}^{*}$ the critical frontier is completely continuous; however, for $p_{0}=p_{0}^{*}$, a fourth-order critical point appears. The stability analysis of the replica-symmetric solution is performed and the regions of validity of such a solution are identified; in particular, the Almeida-Thouless line in the plane field versus temperature is shown to depend on the weight $p_{0}$.Comment: 23pages, 7 ps figure

Eficacia y seguridad de morfina y metadona como analgésicos en un protocolo anestésico balanceado en conejos

The efficacy of preventive analgesia and the cardiopulmonary effects of morphine or methadone in rabbits undergoing experimental skin surgery were evaluated and compared. Thirty-six rabbits were randomly assigned to three experimental groups: Control, Morphine, and Methadone. The rabbits received midazolam 1 mg/kg IM associated with: placebo (NaCl 0.9%) 0.05 ml/kg, methadone 0.5 mg/kg or morphine 0.5 mg/kg, depending on the experimental group. Anaesthesia was induced and maintained with isoflurane. Heart (HR) and respiratory (fR) rates, peripheral oxygen saturation (SpO2), mean arterial pressure (MAP), and body temperature were assessed every 10 minutes. Electrocardiographic examination was performed after sedation, in the trans and immediate postoperative period. After procedure, the control group received tramadol 5 mg/kg IV. Postoperative analgesia was assessed using the visual analogue scale (VAS) and Von-Frey filament stimulation responses. All variables were compared between groups by ANOVA or Friedman. Methadone and morphine caused an increase in MAP (p=0.0112) and a decrease in HR (p=0.0001). fR and SpO2 were reduced in the methadone group (p=0.0100). The response to Von-Frey filaments (p=0.6824) and VAS (p=0.7661) were similar between treatments, however, the control group presented a higher proportion of analgesic rescue (33%) compared to morphine (19%) and methadone (12%). Electrocardiographic variables were similar between treatments (p&gt;0.05). In conclusion, preventive treatment with morphine or methadone was effective in controlling trans and postoperative pain in rabbits, and its cardiovascular effects were limited; however, methadone caused marked respiratory depression.Se evaluó y comparó la eficacia de la analgesia preventiva y los efectos cardiopulmonares de morfina o metadona en conejos sometidos a cirugía cutánea experimental. Treinta y seis conejos fueron asignados al azar a tres grupos experimentales: Control, Morfina y Metadona. Los conejos recibieron midazolam 1 mg/kg vía IM asociado a: placebo (NaCl 0.9%) 0.05 ml/kg, metadona 0.5 mg/kg o morfina 0.5 mg/kg, según el grupo experimental. La anestesia fue inducida y mantenida con isoflurano. La frecuencia cardíaca (FC) y respiratoria (fR), la saturación periférica de oxígeno (SpO2), la presión arterial media (PAM) y la temperatura corporal se evaluaron cada 10 minutos. Se realizó examen electrocardiográfico después de la sedación, en el trans y posoperatorio inmediato. Después del procedimiento, el grupo control recibió tramadol 5 mg/kg vía IV. La analgesia posoperatoria fue evaluada mediante la escala analógica visual (VAS) y la respuesta a estímulos con filamentos de Von-Frey. Todas las variables se compararon entre los grupos mediante ANOVA o Friedman. Metadona y morfina causaron aumento de PAM (p=0.0112) y reducción de la fR (p=0.0001). La fR y la SpO2 se redujeron en el grupo de metadona (p=0.0100). La respuesta a los filamentos de Von-Frey (p=0.6824) y la VAS (p=0.7661) fueron similares entre tratamientos, sin embargo, el grupo control presentó una mayor proporción de rescate analgésico (33%) en comparación con la morfina (19%) y la metadona (12%). Las variables electrocardiográficas fueron similares entre tratamientos (p&gt;0.05). En conclusión, el tratamiento preventivo con morfina o metadona resultó eficaz para controlar el dolor trans y posoperatorio en conejos y sus efectos cardiovasculares fueron limitados; sin embargo, la metadona ocasionó depresión respiratoria marcada