322 research outputs found
Maximal and minimal solutions of second order elliptic and parabolic equations in non-divergence form with measurable coefficients
In this paper we will prove that the supremum and infimum of good solutions of the Dirichlet problem for elliptic and parabolic equations in non-divergence form with measurable coefficients, are good solutions to the same problem
correlating imaging parameters with molecular data an integrated approach to improve the management of breast cancer patients
The goal of this review is to provide an overview of the studies aimed at integrating imaging parameters with molecular biomarkers for improving breast cancer patient's diagnosis and prognosis. The use of diagnostic imaging to extract quantitative parameters related to the morphology, metabolism, and functionality of tumors, as well as their correlation with cancer tissue biomarkers is an emerging research topic. Thanks to the development of imaging biobanks and the technological tools required for extraction of imaging parameters including radiomic features, it is possible to integrate imaging markers with genetic data. This new field of study represents the evolution of radiology–pathology correlation from an anatomic–histologic level to a genetic level, which paves new interesting perspectives for breast cancer management
Water-Mediated Nanostructures for Enhanced MRI: Impact of Water Dynamics on Relaxometric Properties of Gd-DTPA
Recently, rational design of a new class of contrast agents (CAs), based on biopolymers (hydrogels), have received considerable attention in Magnetic Resonance Imaging (MRI) diagnostic field. Several strategies have been adopted to improve relaxivity without chemical modification of the commercial CAs, however, understanding the MRI enhancement mechanism remains a challenge. Methods: A multidisciplinary approach is used to highlight the basic principles ruling biopolymer-CA interactions in the perspective of their influence on the relaxometric properties of the CA. Changes in polymer conformation and thermodynamic interactions of CAs and polymers in aqueous solutions are detected by isothermal titration calorimetric (ITC) measurements and later, these interactions are investigated at the molecular level using NMR to better understand the involved phenomena. Water molecular dynamics of these systems is also studied using Differential Scanning Calorimetry (DSC). To observe relaxometric properties variations, we have monitored the MRI enhancement of the examined structures over all the experiments. The study of polymer-CA solutions reveals that thermodynamic interactions between biopolymers and CAs could be used to improve MRI Gd-based CA efficiency. High-Pressure Homogenization is used to obtain nanoparticles. Results: The effect of the hydration of the hydrogel structure on the relaxometric properties, called Hydrodenticity and its application to the nanomedicine field, is exploited. The explanation of this concept takes place through several key aspects underlying biopolymer-CA's interactions mediated by the water. In addition, Hydrodenticity is applied to develop Gadolinium-based polymer nanovectors with size around 200 nm with improved MRI relaxation time (10-times). Conclusions: The experimental results indicate that the entrapment of metal chelates in hydrogel nanostructures offers a versatile platform for developing different high performing CAs for disease diagnosis
Structural analysis of a simplified model reproducing SARS-CoV-2 S RBD/ACE2 binding site
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is an RNA virus identified as the cause of the coronavirus outbreak in December 2019 (COVID-19). Like all the RNA viruses, SARS-CoV-2 constantly evolves through mutations in its genome, accumulating 1–2 nucleotide changes every month, giving the virus a selective advantage through enhanced transmissibility, greater pathogenicity, and the possibility of circumventing immunity previously acquired by an individual either by natural infection or by vaccination. Several SARS-CoV-2 variants of concern (VoC) have been identified, among which we find Alpha (Lineage B.1.1.7), Beta (Lineage B.1.351), and Gamma (Lineage P.1) variants. Most of the mutations occur in the spike (S) protein, a surface glycoprotein that plays a crucial role in viral infection; the S protein binds the host cell receptor, the angiotensin-converting enzyme of type 2 (ACE2) via the receptor binding domain (RBD) and catalyzes the fusion of the viral membrane with the host cell. In this work, we present the development of a simplified system that would afford to study the change in the SARS-CoV-2 S RBD/ACE2 binding related to the frequent mutations. In particular, we synthesized and studied the structure of short amino acid sequences, mimicking the two proteins’ critical portions. Variations in the residues were easily managed through the one-point alteration of the sequences. Nuclear magnetic resonance (NMR) and circular dichroism (CD) spectroscopies provide insights into ACE2 and SARS-CoV-2 S RBD structure with its related three variants (Alpha, Beta, and Gamma). Spectroscopy data supported by molecular dynamics lead to the description of an ACE2/RBD binding model in which the effect of a single amino acid mutation in changing the binding of S protein to the ACE2 receptor is predictable
Twenty years of the Italian Fanconi Anemia Registry: where we stand and what remains to be learned
The natural history of Fanconi anemia remains hard to establish because of its rarity and its heterogeneous clinical presentation; since 1994, the Italian Fanconi Anemia Registry has collected clinical, epidemiological and genetic data of Italian Fanconi Anemia patients. This registry includes 180 patients with a confirmed diagnosis of Fanconi anemia who have either been enrolled prospectively, at diagnosis, or later on. After enrollment, follow-up data were periodically collected to assess the clinical course, possible complications and long-term survival; the median follow up was 15.6 years. The main goal of the study was to describe the natural history of Fanconi anemia, focusing on the following variables: family history, disease presentation, development of hematological manifestations, development of malignancies, occurrence of hematopoietic stem cell transplantation and survival. Typical morphological and/or hematological abnormalities and/or growth retardation were the most common manifestations at diagnosis; the majority of patients (77%) exhibited hematological abnormalities at the initial presentation, and almost all (96%) eventually developed hematological manifestations. More than half of the patients (57%) underwent a bone-marrow transplant. The occurrence of cancer was quite rare at diagnosis, whereas the cumulative incidence of malignancies at 10, 20 and 30 years was 5%, 8% and 22%, respectively, for hematological cancers and 1%, 15% and 32%, respectively, for solid tumors. Overall survival at 10, 20 and 30 years were 88%, 56% and 37%, respectively; the main causes of death were cancer, complications of the hematological presentation and complications of transplantation. These data clearly confirm the detrimental outcome of Fanconi anemia, with no major improvement in the past decades
Association between mode of breast cancer detection and diagnosis delay
abstract We investigated the association between mode of breast cancer (Bca) detection and diagnosis delay in a case-series of primary, histologically confirmed Bca patients from Southern Italy. Nine hundred and fifty nine women diagnosed with incident, primary Bca were recruited in two southern Italian regions. We grouped the mode of detection into two categories: Self-Detection (S-D) and Mammography (MG). Diagnosis delay was defined as the time between detection and a histologically confirmed diagnosis of invasive Bca. 20.9% detected Bca with MG while 79.1% had S-D Bca. Women who detected Bca themselves (S-D) were more likely to delay breast cancer diagnosis than women who were diagnosed by a mammography (MG) (OR: 2.0; 95% CI: 1.39–2.87); when considering the model adjusted for health system-related characteristics, the risk increased (OR: 2.13; 95% CI: 1.47–3.09). Our study indicates a disadvantage in terms of diagnostic delay for women who were admitted and treated in community hospitals compared to women admitted and treated in breast health services
The Metabolomic Profile in Amyotrophic Lateral Sclerosis Changes According to the Progression of the Disease: An Exploratory Study
Amyotrophic lateral sclerosis (ALS) is a multifactorial neurodegenerative pathology of the upper or lower motor neuron. Evaluation of ALS progression is based on clinical outcomes considering the impairment of body sites. ALS has been extensively investigated in the pathogenetic mechanisms and the clinical profile; however, no molecular biomarkers are used as diagnostic criteria to establish the ALS pathological staging. Using the source-reconstructed magnetoencephalography (MEG) approach, we demonstrated that global brain hyperconnectivity is associated with early and advanced clinical ALS stages. Using nuclear magnetic resonance (1H-NMR) and high resolution mass spectrometry (HRMS) spectroscopy, here we studied the metabolomic profile of ALS patients’ sera characterized by different stages of disease progression—namely early and advanced. Multivariate statistical analysis of the data integrated with the network analysis indicates that metabolites related to energy deficit, abnormal concentrations of neurotoxic metabolites and metabolites related to neurotransmitter production are pathognomonic of ALS in the advanced stage. Furthermore, analysis of the lipidomic profile indicates that advanced ALS patients report significant alteration of phosphocholine (PCs), lysophosphatidylcholine (LPCs), and sphingomyelin (SMs) metabolism, consistent with the exigency of lipid remodeling to repair advanced neuronal degeneration and inflammatio
Challenges and strategies in developing research in nursing
Introducción: Como resultado del perfeccionamiento continuo del Sistema Nacional de Educación, se ha producido en nuestro país una profunda re-conceptualización de los procesos de enseñanza-aprendizaje, teniendo un particular impacto el ámbito investigativo. En este contexto, el presente estudio, persigue evaluar y analizar tanto los conocimientos básicos investigativos por parte de los estudiantes de enfermería, como las destrezas y capacidades de análisis, solución de problemas, argumentación y comparación de experiencias que adquieren los estudiantes al finalizar el estudio. Metodología: El estudio adoptó una metodología de investigación de carácter exploratorio y descriptivo seguido por una estrategia de campo, dirigida a la recolección de información primaria. Las técnicas e instrumentos aplicados fueron de orden cuantitativo (cuestionario pre-test y post-test entre otros) y cualitativo (grupos de discusiones y audio-video grabaciones). Resultados: El procesamiento, y posterior análisis de los resultados obtenidos, permitió identificar los conocimientos previos y posteriores, la satisfacción y la motivación por parte del alumnado, así como un conjunto de factores que inciden, afectan, limitan e influyen en la práctica del proceso evaluativo de los aprendizajes. Conclusiones: los estudiantes valoran el conocimiento de una metodología de investigación y son conscientes de su importancia tanto en la elaboración de un proyecto fin de grado como para su futuro laboral. Sin embargo, no se involucran, en el tema propuesto y si lo hacen, mayoritariamente es por necesidad. Por ello, a pesar de los programas de formación en investigación, los estudiantes se muestran poco dinámicos e incluso reacios a desarrollar cualquier tipo de proyecto investigativo que no esté relacionado con el proyecto fin de grado, materia obligatoria dentro del nuevo plan de estudio
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