Fistula of the mitral-aortic intervalvular fibrosa in a patient with bacterial endocarditis: a case report and systematic literature review.

BACKGROUND: A fistulous tract in the mitro-aortic intervalvular fibrosa (MAIVF) is a rare entity, which presents as a complication of endocarditis or surgical trauma. Generally, it is associated to a pseudoaneurysm of the MAIVF (p-MAIVF) or aortic abscesses. MAIVF fistulas could potentially lead to devastating complications and a high mortality rate. This condition is managed surgically, either by a percutaneous closure or an open surgical approach. Herein we report the complex case of a patient with a MAIVF fistula secondary to bacterial endocarditis. Further clinical deterioration was caused by severe aortic valve insufficiency and hemodynamic compromise, requiring surgical intervention. CASE PRESENTATION: A 74-year-old male patient was admitted to a primary care center with complaints of malaise, asthenia, adynamia, hyporexia, and lower limb edema over the past eight days. His past medical history is positive for arterial hypertension and being monorenal. A transesophageal echocardiogram (TEE) was performed, exhibiting a 56% left ventricle ejection fraction (LVEF) and complicated aortic valve endocarditis. Surgical management through an open approach included vegetation resection, valve replacement, and closure of the MAIVF fistula. After completing antibiotic therapy, the patient was discharged without complications. During postoperative follow-up, the patient remained asymptomatic, and the control echocardiogram showed no signs of MAIVF fistula.4. CONCLUSIONS: The clinical case of a patient with a MAIVF fistula secondary to endocarditis by Streptococcus Anginous was presented. The fistulous tract was not associated to p-MAIVF or aortic abscess, findings which further deteriorate the patient's condition and increase the likelihood of fatality. This case reinforces the importance of a prompt diagnosis through cardiac imaging and timely surgical closure of the defect.

Critical loss of primary implant stability in osteosynthesis locking screws under cyclic overloading.

Primary implant stability, which refers to the stability of the implant during the initial healing period is a crucial factor in determining the long-term success of the implant and lays the foundation for secondary implant stability achieved through osseointegration. Factors affecting primary stability include implant design, surgical technique, and patient-specific factors like bone quality and morphology. In vivo, the cyclic nature of anatomical loading puts osteosynthesis locking screws under dynamic loads, which can lead to the formation of micro cracks and defects that slowly degrade the mechanical connection between the bone and screw, thus compromising the initial stability and secondary stability of the implant. Monotonic quasi-static loading used for testing the holding capacity of implanted screws is not well suited to capture this behavior since it cannot capture the progressive deterioration of peri­implant bone at small displacements. In order to address this issue, this study aims to determine a critical point of loss of primary implant stability in osteosynthesis locking screws under cyclic overloading by investigating the evolution of damage, dissipated energy, and permanent deformation. A custom-made test setup was used to test implanted 2.5 mm locking screws under cyclic overloading test. For each loading cycle, maximum forces and displacement were recorded as well as initial and final cycle displacements and used to calculate damage and energy dissipation evolution. The results of this study demonstrate that for axial, shear, and mixed loading significant damage and energy dissipation can be observed at approximately 20 % of the failure force. Additionally, at this load level, permanent deformations on the screw-bone interface were found to be in the range of 50 to 150 mm which promotes osseointegration and secondary implant stability. This research can assist surgeons in making informed preoperative decisions by providing a better understanding of the critical point of loss of primary implant stability, thus improving the long-term success of the implant and overall patient satisfaction.

Multi-omics regulatory network inference in the presence of missing data.

A key problem in systems biology is the discovery of regulatory mechanisms that drive phenotypic behaviour of complex biological systems in the form of multi-level networks. Modern multi-omics profiling techniques probe these fundamental regulatory networks but are often hampered by experimental restrictions leading to missing data or partially measured omics types for subsets of individuals due to cost restrictions. In such scenarios, in which missing data is present, classical computational approaches to infer regulatory networks are limited. In recent years, approaches have been proposed to infer sparse regression models in the presence of missing information. Nevertheless, these methods have not been adopted for regulatory network inference yet. In this study, we integrated regression-based methods that can handle missingness into KiMONo, a Knowledge guided Multi-Omics Network inference approach, and benchmarked their performance on commonly encountered missing data scenarios in single- and multi-omics studies. Overall, two-step approaches that explicitly handle missingness performed best for a wide range of random- and block-missingness scenarios on imbalanced omics-layers dimensions, while methods implicitly handling missingness performed best on balanced omics-layers dimensions. Our results show that robust multi-omics network inference in the presence of missing data with KiMONo is feasible and thus allows users to leverage available multi-omics data to its full extent.

Caracterización epidemiológica y clínica de los pacientes intervenidos en una cirugía de revascularización miocárdica / Epidemiological and clinical characterization of patients undergoing myocardial revascularization surgery

Resumen Introducción: La cardiopatía isquémica es un problema de salud pública y puede tratarse por medio de la revascularización miocárdica. Objetivo: Estructurar el primer perfil epidemiológico y clínico de los pacientes intervenidos en Tolima. Materiales y método: Es un estudio de corte transversal, de 183 pacientes mayores de 18 años programados para revascularización miocárdica entre septiembre de 2018 y septiembre de 2019. Se eligieron variables clínicas y demográficas. Se realizó un análisis descriptivo, un análisis bivariado para mortalidad y circulación extracorpórea, y una regresión logística para la mortalidad intrahospitalaria. Resultados: La edad media de los pacientes fue de 66.7 años y un 68.85% correspondió a la población femenina. Se presentó HA en 80.33%, tabaquismo en 49.18%, dislipidemia en 44.81% y DM en 40.98%. Se registró mayor proporción de complicaciones en los pacientes intervenidos sin CEC, como complicaciones pulmonares, FA de novo y una estancia intrahospitalaria y posoperatoria mayor. Los pacientes que fallecieron tuvieron mayor proporción de complicaciones, mayor estancia hospitalaria, mayor cantidad de reintervenciones y tiempo de ventilación mecánica. El modelo de regresión reveló una relación con mortalidad para los pacientes que tuvieron requerimiento de diálisis (OR = 8.7) complicaciones pulmonares (OR = 10.5) y desarrollo de FA de novo (OR = 11.3). Conclusiones: Este estudio caracteriza a la población para generar marcos de referencia en un grupo poco estudiado como el tolimense. De modo adicional, se presentaron mejores desenlaces en los pacientes llevados a revascularización miocárdica con circulación extracorpórea, y unas relaciones claras de mortalidad y complicaciones posoperatorias.

Abstract Introduction: The ischemic cardiopathy is a public health issue, that can be treated with a coronary artery bypass grafting (CABG). Objective: To present the first clinical and epidemiological profile of CABG treated patients in Tolima, Colombia. Materials and method: We conduct a cross sectional study, including 183 patients driven to a CABG procedure, between September 2018-2019. We chose clinical and demographic variables. And posteriorly, performed a descriptive and bivariate analysis, including mortality and extracorporeal circulation. Besides, we completed a logistic regression for intrahospital mortality. Results: The average age of our patients was 66,7 years, and 68.85% were female. They presented in an 80.33% arterial hypertension, smoked an 49.18%, had dyslipidemia and diabetes 44.81% and 40.95% respectively. There were more complications in patients who were drove into on pump CABG, primarily pulmonary complications, atrial fibrillation, mayor intrahospital and post-operatory stay. The patients who died, present more complications, intrahospital stay, reinterventions and mechanic ventilation time. Our regression model evidenced mortality association with post-operatory dialysis (OR = 8.7), pulmonary complications (OR = 10.5) and new atrial fibrillation (OR = 11.3). Conclusions: This study aim to characterize the Tolima's population, creating a reference in this less studied population. On the other side, the study discuss the better outcomes in patients taken to myocardial bypass with extracorporeal membrane oxygenation. And the association between dead and certain postoperative complications.

Striking confinement effect: AuCl4(-) binding to amines in a nanocage cavity.

Binding of AuCl(4)(-) to amine groups tethered to the interior of a 2 nm siloxane nanocage was determined in solutions containing various concentrations of acid. The mode of binding was inferred from EXAFS and UV-vis spectra to be by ligand exchange of amine for chloride, which implies that the amines remain unprotonated. Cyclic voltammetry confirmed that the Au complexes bind to the nanocage interior and established a 1:1 relationship between bound Au complex and amine groups. The results suggested a 5-7 pH unit shift in the protonation constant of the interior amines relative to free amines in solution.

In situ transient FTIR and XANES studies of the evolution of surface species in CO oxidation on Au/TiO2.

The adsorption of CO and its reaction with oxygen were investigated using a combination of in situ Fourier transform infrared spectroscopy, step response measurements in a microreactor, (18)O isotopic labeling, and X-ray absorption near edge structure spectroscopy. An as-prepared sample in which Au is present as a surface oxyhydroxy complex does not adsorb CO. On an activated sample in which only metallic Au is detected, 0.18 +/- 0.03 mol CO/(mol Au) are adsorbed on Au at -60 degrees C, which shows an IR band at 2090 cm(-1). When oxygen is present in the gas phase, this species reacts with a turnover rate of 1.4 +/- 0.2 mol CO(mol Au min)(-1), which is close to the steady-state turnover rate. In contrast, there is a very small quantity of adsorbed oxygen on Au. A small IR peak at 1242 cm(-1) appears when an activated sample is exposed to CO. It reacts rapidly with oxygen and is shifted to 1236 cm(-1) if (18)O is used. It is assigned to the possible intermediate hydroxycarbonyl.

Characterization of iron catalysts prepared by chemical vapor deposition on nonzeolitic supports.

Chemical vapor deposition (CVD) of FeCl3 has been used to deposit Fe3+ ions on the surface of sulfated zirconia (SZ) and silica-alumina (SA). Upon exposure to FeCl3 vapor most Brønsted acid sites and silanol groups are replaced by Fe, as evidenced by IR. With SZ the concentration of the acid sites and thus the retention of Fe increase with the sulfate loading up to approximately 45% of a monolayer, followed by an abrupt decrease at higher loadings. This indicates condensation of sulfate groups to polysulfates, which is in line with a lower number of Brønsted sites per sulfate. Release of HCl due to the reaction of Brønsted sites with FeCl3 peaks at 85 degrees C for SZ but only at 345 degrees C for SA. After replacing Cl- by OH- and calcining, the materials were tested as De-NOx catalysts and characterized by temperature-programmed reduction (TPR) with H2 or CO. Mononuclear and dinuclear oxo-ions of Fe coexist with Fe oxide particles in calcined Fe/SA, resulting in a low selectivity for NOx reduction. During reduction of Fe/SA up to 800 degrees C, a significant fraction of the Fe forms a chemical compound with SA, possibly an aluminate. In Fe/SZ the Fe dramatically increases the reducibility of the sulfate groups, from 57% partial reduction to SO2 in the absence of Fe, to 90% deep reduction to S2- ions in its presence. Formation of Fe sulfide is indicated by the enhanced sulfur retention upon reduction. Fe/SZ is active for NOx reduction with isobutane. Catalysts with low Fe content that are prepared by controlled sublimation are superior to those prepared by impregnation. At 450 degrees C and GHSV = 30,000 h(-1), 65% of NOx is reduced to N2 in excess O2.

Activation of Au/TiO2 catalyst for CO oxidation.

Changes in a Au/TiO(2) catalyst during the activation process from an as-prepared state, consisting of supported AuO(x)(OH)(4-2x)(-) species, were monitored with X-ray absorption spectroscopy and FTIR spectroscopy, complemented with XPS, microcalorimetry, and TEM characterization. When the catalyst was activated with H(2) pulses at 298 K, there was an induction period when little changes were detected. This was followed by a period of increasing rate of reduction of Au(3+) to Au(0), before the reduction rate decreased until the sample was fully reduced. A similar trend in the activation process was observed if CO pulses at 273 K or a steady flow of CO at about 240 K was used to activate the sample. With both activation procedures, the CO oxidation activity of the catalyst at 195 K increased with the degree of reduction up to 70% reduction, and decreased slightly beyond 80% reduction. The results were consistent with metallic Au being necessary for catalytic activity.