Fourier Mukai Transforms for Gorenstein Schemes

We extend to singular schemes with Gorenstein singularities or fibered in schemes of that kind Bondal and Orlov's criterion for an integral functor to be fully faithful. We also contemplate a criterion for equivalence. We offer a proof that is new even if we restrict to the smooth case. In addition, we prove that for locally projective Gorenstein morphisms, a relative integral functor is fully faithful if and only if its restriction to each fibre also is it. These results imply the invertibility of the usual relative Fourier-Mukai transform for an elliptic fibration as a direct corollary.Comment: Final version. To appear in Advances in Mathematic

Spatio-temporal Bounded Noises, and transitions induced by them in solutions of real Ginzburg-Landau model

In this work, we introduce two spatio-temporal colored bounded noises, based on the zero-dimensional Cai-Lin and Tsallis-Borland noises. We then study and characterize the dependence of the defined bounded noises on both a temporal correlation parameter $\tau$ and on a spatial coupling parameter $\lambda$. The boundedness of these noises has some consequences on their equilibrium distributions. Indeed in some cases varying $\lambda$ may induce a transition of the distribution of the noise from bimodality to unimodality. With the aim to study the role played by bounded noises on nonlinear dynamical systems, we investigate the behavior of the real Ginzburg-Landau time-varying model additively perturbed by such noises. The observed phase transitions phenomenology is quite different from the one observed when the perturbations are unbounded. In particular, we observed an inverse "order-to-disorder" transition, and a re-entrant transition, with dependence on the specific type of bounded noise.Comment: 12 (main text)+5 (supplementary) page

Effect of Hemodynamic Changes in Plasma Propofol Concentrations Associated with Knee-Chest Position in Spinal Surgery: A Prospective Study

Background: Anesthesia induction and maintenance with propofol can be guided by target-controlled infusion (TCI) systems using pharmacokinetic (Pk) models. Physiological variables, such as changes in cardiac output (CO), can influence propofol pharmacokinetics. Knee-chest (KC) surgical positioning can result in CO changes. Objectives: This study aimed to evaluate the relationship between propofol plasma concentration prediction and CO changes after induction and KC positioning. Methods: This two-phase prospective cohort study included 20 patients scheduled for spinal surgery. Two different TCI anesthesia protocols were administered after induction. In phase I (n = 9), the loss of consciousness (LOC) concentration was set as the propofol target concentration and CO changes following induction and KC positioning were quantified. In phase II (n = 11), based on data from phase I, two reductions in the propofol target concentration on the pump were applied after LOC and before KC positioning. Propofol plasma concentrations were measured at different moments in both phases: after induction and after KC positioning. Results: Schnider Pk model showed a good performance in predicting propofol concentration after induction; however, after KC positioning, when a significant drop in CO occurred, the measured propofol concentrations were markedly underestimated. Intended reductions in the propofol target concentration did not attenuate HD changes. In the KC position, there was no correlation between the propofol concentration estimated by the Pk model and the measured concentration in plasma, as the latter was much higher (P = 0.013) while CO and BIS decreased significantly (P < 0.001 and P = 0.004, respectively). Conclusions: Our study showed that the measured propofol plasma concentrations during the KC position were significantly underestimated by the Schnider Pk model and were associated with significant CO decrease. When placing patients in the KC position, anesthesiologists must be aware of pharmacokinetic changes and, in addition to standard monitoring, the use of depth of anesthesia and cardiac output monitors may be considered in high-risk patients.This work was partially funded by the Foundation for Science and Technology, FCT, through national (MEC) and European structural (FEDER) funds, in the scope of the research projects UID/MAT/04106/2019 (CIDMA/UA), UID/CEC/00127/2019 (IEETA/UA) and UID/MAT/00144/2019 (CMUP/UP). This work was also partially suported by Portugal 2020 under the Competitiveness and Internationalization Operational Program, and by the European Regional Development Fund through project SOCA-Smart Open Campus (CENTRO-01-0145-FEDER-000010), acknowledgements from Sonia Gouveia. Aura Silva also acknowledges the postdoctoral grant by FCT (ref. SFRH/BPD/75697/2011).info:eu-repo/semantics/publishedVersio

Aerobic Damage to [FeFe]-Hydrogenases: Activation Barriers for the Chemical Attachment of O2.

[FeFe]-hydrogenases are the best natural hydrogen-producing enzymes but their biotechnological exploitation is hampered by their extreme oxygen sensitivity. The free energy profile for the chemical attachment of O2 to the enzyme active site was investigated by using a range-separated density functional re-parametrized to reproduce high-level ab initio data. An activation free-energy barrier of 13 kcal mol(-1) was obtained for chemical bond formation between the di-iron active site and O2 , a value in good agreement with experimental inactivation rates. The oxygen binding can be viewed as an inner-sphere electron-transfer process that is strongly influenced by Coulombic interactions with the proximal cubane cluster and the protein environment. The implications of these results for future mutation studies with the aim of increasing the oxygen tolerance of this enzyme are discussed

Surgery and radioembolization of liver tumors

Surgical resection is considered the curative treatment par excellence for patients with primary or metastatic liver tumors. However, less than 40% of them are candidates for surgery, either due to nonmodifiable factors (comorbidities, age, liver dysfunction. . .), or to the invasion or proximity of the tumor to the main vascular requirements, the lack of a future liver remnant (FLR) adequate to maintain postoperative liver function, or criteria oftumor size and number. In these lastfactors, hepatic radioembolization has been shown to play a role as a presurgical tool, either by hypertrophy of the FLR or by reducing tumor size that manages to reduce tumor staging (term known as downstaging ¨ ¨ ). To these is added a third factor, which is its ability to apply the test oftime, which makes it possible to identify those patients who present progression of the disease in a short period of time (both locally and at distance), avoiding a unnecessary surgery. This paper aims to review RE as a tool to facilitate liver surgery, both through the experience of our center and the available scientific evidence.La resección quirúrgica se considera eltratamiento curativo por excelencia para los pacientes con tumores hepáticos primarios o metastásicos. Sin embargo, menos del 40% de ellos son candidatos a cirugía, ya sea por factores no modificables (comorbilidades, edad, disfunción hepática. . .), como por la invasión o proximidad del tumor a los principales pedículos vasculares, la falta de un futuro remanente hepático (FRH) adecuado para mantener una función hepática postoperatoria, o criterios de tamano˜ y numero tumoral. En estos últimos factores, la radioembolización hepática ha mostrado tener un papel como herramienta prequirúrgica, ya sea mediante la hipertrofia del FRH o mediante la reducción del tamano˜ tumoral que consigue disminuir la estadificación tumoral (término conocido como “downstaging”). A estos se suma un tercer factor, que es su capacidad de aplicar el test del tiempo, que permite identificar aquellos pacientes que presenten en un plazo corto de tiempo progresión de la enfermedad (tanto a nivel local como a distancia), evitándoles una cirugía innecesaria. En este trabajo se pretende hacer una revisión de la RE como herramienta facilitadora de la cirugía hepática, tanto a través de la experiencia de nuestro centro como de la evidencia científica disponible

Snail1 suppresses TGF-β-induced apoptosis and is sufficient to trigger EMT in hepatocytes

11 páginas.Although TGF-β suppresses early stages of tumour development, it later contributes to tumour progression when cells become resistant to its suppressive effects. In addition to circumventing TGF-β-induced growth arrest and apoptosis, malignant tumour cells become capable of undergoing epithelial-to-mesenchymal transition (EMT), favouring invasion and metastasis. Therefore, defining the mechanisms that allow cancer cells to escape from the suppressive effects of TGF-β is fundamental to understand tumour progression and to design specific therapies. Here, we have examined the role of Snail1 as a suppressor of TGF-β-induced apoptosis in murine non-transformed hepatocytes, rat and human hepatocarcinoma cell lines and transgenic mice. We show that Snail1 confers resistance to TGF-β-induced cell death and that it is sufficient to induce EMT in adult hepatocytes, cells otherwise refractory to this transition upon exposure to TGF-β. Furthermore, we show that Snail1 silencing prevents EMT and restores the cell death response induced by TGF-β. As Snail1 is a known target of TGF-β signalling, our data indicate that Snail1 might transduce the tumour-promoting effects of TGF-β, namely the EMT concomitant with the resistance to cell death.Peer reviewe