Publications by authors named "Luis Betancourt"

Article Synopsis
  • The study examines the methane dry reforming (DRM) reaction using a new type of catalyst, PdAcCeOM, which has a unique interface between palladium (Pd) and cerium oxide (CeO) that enhances its effectiveness compared to traditional methods.
  • In-depth analysis showed that the unique surface arrangement of Pd and Ce in PdAcCeOM allows for more efficient reactions, primarily due to strong interactions between Pd and CeO and the formation of specific carbons on these surfaces.
  • The findings highlight that the new catalyst facilitates a preferred reaction pathway for converting methane to carbon monoxide, while traditional catalysts are hindered by competing reactions like the reverse water gas shift.
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An understanding of the immune mechanisms that lead to rejection versus tolerance of allogeneic pancreatic islet grafts is of paramount importance, as it facilitates the development of innovative methods to improve the transplant outcome. Here, we used our established intraocular islet transplant model to gain novel insight into changes in the local metabolome and proteome within the islet allograft's immediate microenvironment in association with immune-mediated rejection or tolerance. We performed integrated metabolomics and proteomics analyses in aqueous humor samples representative of the graft's microenvironment under each transplant outcome.

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Studying the oxygen reduction reaction (ORR) in the alkaline electrolyte has proven to promote better catalytic responses and accessibility to commercialization. Ni-nanowires (NWs) were synthesized via the solvothermal method and modified with Pt using the spontaneous galvanic displacement method to obtain PtNi-NWs. Carbon Vulcan XC-72R (V) was used as the catalyst support, and they were doped with NH to obtain PtNi-NWs/V and PtNi-NWs/V-NH.

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The application of artificial intelligence (AI) and machine learning (ML) in biomedical research promises to unlock new information from the vast amounts of data being generated through the delivery of healthcare and the expanding high-throughput research applications. Such information can aid medical diagnoses and reveal various unique patterns of biochemical and immune features that can serve as early disease biomarkers. In this report, we demonstrate the feasibility of using an AI/ML approach in a relatively small dataset to discriminate among three categories of samples obtained from mice that either rejected or tolerated their pancreatic islet allografts following transplant in the anterior chamber of the eye, and from naïve controls.

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Objective: To evaluate the pathologic response after neoadjuvant chemotherapy in patients with breast cancer according to the stromal tumor-infiltrating lymphocytes (TILs) as well as the evaluation of overall and disease-free survival according to TILs.

Methods: A six years (2008-2013) review was done including patients with locally advanced breast cancer that received neoadjuvant therapy and then surgery. An evaluation of the percentage of TILs was done in the pretreatment biopsies and a correlation analysis and survival curves were done.

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Objective: To determine the false-negative rate, sensitivity, and diagnostic accuracy of the frozen section analysis of the sentinel lymph node (SLN) biopsy in early-stage breast cancer compared to the definitive section and to identify the factors that could be associated with the appearance of false-negative cases. Secondarily, to evaluate the pathological results of cases submitted to completion axillary lymph node dissection (ALND) for positive SLN.

Methods: We performed a five-year review of cases (2011-2015), including patients with early-stage breast cancer undergoing SLN biopsy, with frozen section evaluation and subsequent definitive pathological analysis.

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The ketogenic diet (KD) is acknowledged as an unconventional option in the treatment of epilepsy. Several lines of investigation point to a possible role of glutamate and gamma-aminobutyric acid (GABA) as main contributors in this protective effect. Other biomolecules could also be involved in the beneficial consequence of the KD, for example, the diamine agmatine has been suggested to block imidazole and glutamate NMDA receptor and serves as an endogenous anticonvulsant in different animal models of epilepsy.

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Background: Preterm neonates exhibit several deficiencies that endanger their lives. Understanding those disturbances will provide tools for the management of preterm neonates. The present work focuses on arginine and citrulline which has been flagged among the biochemical landmarks of prematurity.

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In this study we probe the electrocatalytic activity of Pt nanoparticles supported on ceria nanoparticles (NPs) and nanorods (NRs) in the ethanol oxidation reaction (EOR) in alkaline media. The goal of this study was to relate morphology, support structure and composition to the EOR catalytic activity by using in situ X-ray absorption fine structure (XAFS) studies. Cyclic voltammetry experiments showed that both ceria supported catalysts (NP vs.

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A growing body of research shows that personality pathology in adolescents is clinically distinctive and frequently stable into adulthood. A reliable and useful method for rating personality pathology in adolescent patients has the potential to enhance conceptualization, dissemination, and treatment effectiveness. The aim of this study is to examine the clinical validity of a prototype matching approach (derived from the Shedler Westen Assessment Procedure-Adolescent Version) for quantifying personality pathology in an adolescent inpatient sample.

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Lymph node involvement is considered to be one of the most important independent prognostic factors in breast cancer. In patients without palpable lymphadenopathies, the method of choice for determining this involvement is the sentinel lymph node biopsy. In the presence of macrometastases, the current standard is to perform axillary lymph node dissection in spite of the knowledge that the involvement of non-sentinel lymph nodes is approximately 50%.

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Objectives: To determine patterns in amino acids (arginine, GABA, glutamate and glutamine) and the diamine (agmatine) in plasma and cerebrospinal fluid (CSF) of mild and severe preeclampsia compared to control patients, using capillary zone electrophoresis to generate methods for refining diagnosis and prognosis and shed light on the pathophysiological mechanisms of preeclampsia.

Study Design: This is an observational case-control study in pregnant women that attended the emergency ward of the University Hospital, Mérida, Venezuela, during the period April, 2009-April 2010.

Main Outcome Measures: Molar concentration of amino acids and diamine in plasma and CSF in control, mild and severe preeclampsia patients.

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Agmatine is a putative neurotransmitter in the brain. Current analytical techniques do not allow the detection of agmatine in extracellular fluid, making it difficult to study its physiological role. However, a new method for in vivo monitoring agmatine in the brain was developed.

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