Lone Pair Effect, Structural Distortions and Potential for Superconductivity in Tl Perovskites

Drawing the analogy to BaBiO3, we investigate via ab-initio electronic structure calculations potential new superconductors of the type ATlX3 with A = Rb, Cs and X = F, Cl, and Br, with a particular emphasis on RbTlCl3. Based on chemical reasoning, supported by the calculations, we show that Tl-based perovskites have structural and charge instabilities driven by the lone pair effect, similar to the case of BaBiO3, effectively becoming A2Tl1+Tl3+X6. We find that upon hole doping of RbTlCl3, structures without Tl1+, Tl3+ charge disproportionation become more stable, although the ideal cubic perovskite, often viewed as the best host for superconductivity, should not be the most stable phase in the system. The known superconductor (Sr,K)BiO3 and hole doped RbTlCl3, predicted to be most stable in the same tetragonal structure, display highly analogous calculated electronic band structures.Comment: 5 pages, 5 figure

Autoestima, percepción de estrés y ánimo depresivo en grupos de riesgo.

Sin resume

Impacto de la apertura comercial en la productividad total de los factores: una visión comparativa global del 2000 al 2019

El presente estudio analiza diversos factores macroeconómicos relacionados a la apertura comercial que influyen en la Productividad Total de los Factores (PTF) de los años 2000 al 2019 de una forma comparativa global entre los países desarrollados de Asia y Europa y los países en desarrollo de América Latina. El método econométrico utilizado es Mínimos Cuadrados Generalizados Factibles para una muestra de 16 países de cada grupo mencionado. Los resultados indican que, para las economías avanzadas, las exportaciones de manufactura, la importación de insumos y la Inversión Extranjera Directa tienen un efecto positivo y significativo sobre la PTF, mientras que para las economías en desarrollo solo las exportaciones de bienes manufacturados e Inversión Extranjera Directa tienen un efecto positivo y significativo. El resto de las variables resultaron negativas o no significativas. Por tanto, consideramos necesario un cambio en la política comercial latinoamericana para un mejor aprovechamiento de los beneficios de la apertura comercial sobre la PTF.This study analyzes various macroeconomic factors related to trade openness that influence Total Factor Productivity (TFP) from 2000 to 2019 in a global comparative perspective between the developed countries of Asia and Europe and the developing countries of America. Latin. The econometric method used is Feasible Generalized Least Squares for a sample of 16 countries from each mentioned group. The results indicate that, for advanced economies, manufacturing exports, input imports and Foreign Direct Investment have a positive and significant effect on TFP, while for developing economies only exports of manufactured goods and Foreign Direct Investment have a positive and significant effect. The rest of the variables were negative or not significant. Therefore, we believe that a change in Latin American trade policy is necessary to make better use of the benefits of trade liberalization on TFP

A large new family of filled skutterudites stabilized by electron count

Based on the interplay of theory and experiment, a large new family of filled group 9 (Co, Rh and Ir) skutterudites is designed and synthesized. The new materials fill the empty cages in the structures of the known binary CoSb3, RhSb3 and IrSb3 skutterudites with alkaline, alkaline earth, and rare earth atoms to create compounds of the type AyB4X12; A atoms fill the cages to a fraction y, B are the group 9 transition metals, and X is a mixture of electronegative main group elements chosen to achieve chemical stability by adjusting the electron counts to electron-precise values. Forty-three new compounds are reported, antimony-tin and phosphorous-silicon based, with 63 compositional variations presented. The new family of compounds is large and general. The results described here can be extended to the synthesis of hundreds of new group 9 filled skutterudites.Comment: A revised version with the title"A large family of filled skutterudites stabilized by electron count"will appear in Nature Communication

Thromboxane inhibition improves renal perfusion and excretory function in severe congestive heart failure

AbstractObjectivesThe aim of this study was to evaluate whether thromboxane inhibition can favorably affect renal perfusion and clinical conditions in patients affected by severe heart failure.BackgroundThe renal formation of the vasoconstrictor thromboxane A2(TxA2) is increased during cardiac failure.MethodsBy oral administration of picotamide (a renal TxA2synthase and TxA2/prostaglandin H2receptor inhibitor), we blocked renal TxA2. Fourteen patients in New York Heart Association functional class IV were studied according to a randomized, double-blinded, cross-over design. Each of the two eight-day periods of testing was preceded by a three-day period during which certain vasoactive medications were stopped.ResultsDaily 24-h total urinary thromboxane B2(TxB2), the stable metabolite of TxA2, dropped at the end of picotamide treatment (p < 0.01 vs. baseline). Compared with placebo, effective renal plasma flow and the glomerular filtration rate increased (p < 0.01 and p < 0.05, respectively), thus leading to a significant decrease in the filtration fraction (p < 0.01). Renal vascular resistance decreased consistently (p < 0.01). In all patients, picotamide treatment was associated with an increase in diuresis and natriuresis (p < 0.001 vs. baseline). Plasma creatinine decreased (p < 0.05 vs. baseline). Patients also showed improvement in several clinical parameters, including a significant decrease in both pulmonary and venous pressure (p < 0.01 vs. baseline).ConclusionsThese results indicate that renal thromboxane formation plays an important role in renal vascular resistance in patients with severe heart failure, such as those described in the present study. Inhibition of TxA2improves renal hemodynamics and kidney function and favorably affects indexes of cardiac performance

Ordering cancer mutational profiles of cross-sectional copy number alterations

Understanding the dynamical evolution of cancer, with the final goal of developing effective techniques for diagnosis, prediction and treatment is one of the main challenges of modern biosciences. In this paper we approach the temporal ordering reconstruction problem, which refers to the temporal sorting of a collection of static biological data. The solution of this problem may help in better understanding the key principles and properties of the disease progression. By using a previously proposed technique for extracting temporal progressions from cross-sectional cancer gene expression data, we develop a novel methodology to be applied to static cross-sectional copy number alterations, and we test it on patients diagnosed with colorectal cancer at different stages. To capture distinct aspects of this complex phenomenon, we define several measures of chromosomal alterations and filters targeting significant portions of chromosomes. Results obtained with various measures and filters highlight the best setting for the problem, the most relevant chromosomal alterations and emphasise the influence that copy number alterations hitting key genes may have on the development of the disease

Superconductivity in Weyl Semimetal Candidate MoTe2

In recent years, layered transition-metal dichalcogenides (TMDs) have attracted considerable attention because of their rich physics; for example, these materials exhibit superconductivity, charge density waves, and the valley Hall effect. As a result, TMDs have promising potential applications in electronics, catalysis, and spintronics. Despite the fact that the majority of related research focuses on semiconducting TMDs (e.g., MoS2), the characteristics of WTe2 are provoking strong interest in semimetallic TMDs with extremely large magnetoresistance, pressure-driven superconductivity, and the predicted Weyl semimetal (WSM) state. In this work, we investigate the sister compound of WTe2, MoTe2, which is also predicted to be a WSM and a quantum spin Hall insulator in bulk and monolayer form, respectively. We find that MoTe2 exhibits superconductivity with a resistive transition temperature Tc of 0.1 K. The application of a small pressure (such as 0.4 GPa) is shown to dramatically enhance the Tc, with a maximum value of 8.2 K being obtained at 11.7 GPa (a more than 80-fold increase in Tc). This yields a dome-shaped superconducting phase diagram. Further explorations into the nature of the superconductivity in this system may provide insights into the interplay between strong correlations and topological physics.Comment: 20 pages, 5 figure

Surgical site infection after caesarean section. Space for post-discharge surveillance improvements and reliable comparisons

Surgical site infections (SSI) after caesarean section (CS) represent a substantial health system concern. Surveying SSI has been associated with a reduction in SSI incidence. We report the findings of three (2008, 2011 and 2013) regional active SSI surveillances after CS in community hospital of the Latium region determining the incidence of SSI. Each CS was surveyed for SSI occurrence by trained staff up to 30 post-operative days, and association of SSI with relevant characteristics was assessed using binomial logistic regression. A total of 3,685 CS were included in the study. A complete 30 day post-operation follow-up was achieved in over 94% of procedures. Overall 145 SSI were observed (3.9% cumulative incidence) of which 131 (90.3%) were superficial and 14 (9.7%) complex (deep or organ/space) SSI; overall 129 SSI (of which 89.9% superficial) were diagnosed post-discharge. Only higher NNIS score was significantly associated with SSI occurrence in the regression analysis. Our work provides the first regional data on CS-associated SSI incidence, highlighting the need for a post-discharge surveillance which should assure 30 days post-operation to not miss data on complex SSI, as well as being less labour intensive

Role of Dietary Carotenoids in Frailty Syndrome: A Systematic Review

Unbalanced diets and altered micronutrient intake are prevalent in the aging adult population. We conducted a systematic review to appraise the evidence regarding the association between single (α-carotene, β-carotene, lutein, lycopene, β-cryptoxanthin) or total carotenoids and frailty syndrome in the adult population. The literature was screened from study inception to December 2021, using six different electronic databases. After establishing inclusion criteria, two independent researchers assessed the eligibility of 180 retrieved articles. Only 11 fit the eligibility requirements, reporting five carotenoid entries. No exclusion criteria were applied to outcomes, assessment tools, i.e., frailty constructs or surrogates, recruitment setting, general health status, country, and study type (cohort or cross-sectional). Carotenoid exposure was taken as either dietary intake or serum concentrations. Cross-sectional design was more common than longitudinal design (n = 8). Higher dietary and plasma levels of carotenoids, taken individually or cumulatively, were found to reduce the odds of physical frailty markedly, and the evidence showed consistency in the direction of association across all selected studies. Overall, the methodological quality was rated from moderate (27%) to high (73%). Prevention of micronutrient deficiencies has some potential to counteract physical decline. Considering carotenoids as biological markers, when monitoring micronutrient status, stressing increased fruit and vegetable intake may be part of potential multilevel interventions to prevent or better manage disability