260 research outputs found
Advanced Model for Fast Assessment of Piezoelectric Micro Energy Harvesters
The purpose of this work is to present recent advances in modeling and design of piezoelectric energy harvesters, in the framework of micro-electro-mechanical systems (MEMS). More specifically, the case of inertial energy harvesting is considered, in the sense that the kinetic energy due to environmental vibration is transformed into electrical energy by means of piezoelectric transduction. The execution of numerical analyses is greatly important in order to predict the actual behavior of MEMS devices and to carry out the optimization process. In the common practice, the results are obtained by means of burdensome 3D finite element analyses (FEA). The case of beams could be treated by applying 1D models, which can enormously reduce the computational burden with obvious benefits in the case of repeated analyses. Unfortunately, the presence of piezoelectric coupling may entail some serious issues in view of its intrinsically three-dimensional behavior. In this paper, a refined, yet simple, model is proposed with the objective of retaining the Euler-Bernoulli beam model, with the inclusion of effects connected to the actual three-dimensional shape of the device. The proposed model is adopted to evaluate the performances of realistic harvesters, both in the case of harmonic excitation and for impulsive loads
Combined mechanistic modeling and machine-learning approaches in systems biology - A systematic literature review
Background and objective: Mechanistic-based Model simulations (MM) are an effective approach commonly employed, for research and learning purposes, to better investigate and understand the inherent behavior of biological systems. Recent advancements in modern technologies and the large availability of omics data allowed the application of Machine Learning (ML) techniques to different research fields, including systems biology. However, the availability of information regarding the analyzed biological context, sufficient experimental data, as well as the degree of computational complexity, represent some of the issues that both MMs and ML techniques could present individually. For this reason, recently, several studies suggest overcoming or significantly reducing these drawbacks by combining the above-mentioned two methods. In the wake of the growing interest in this hybrid analysis approach, with the present review, we want to systematically investigate the studies available in the scientific literature in which both MMs and ML have been combined to explain biological processes at genomics, proteomics, and metabolomics levels, or the behavior of entire cellular populations. Methods: Elsevier Scopus®, Clarivate Web of Science™ and National Library of Medicine PubMed® databases were enquired using the queries reported in Table 1, resulting in 350 scientific articles. Results: Only 14 of the 350 documents returned by the comprehensive search conducted on the three major online databases met our search criteria, i.e. present a hybrid approach consisting of the synergistic combination of MMs and ML to treat a particular aspect of systems biology. Conclusions: Despite the recent interest in this methodology, from a careful analysis of the selected papers, it emerged how examples of integration between MMs and ML are already present in systems biology, highlighting the great potential of this hybrid approach to both at micro and macro biological scales
Calcific lesion preparation for coronary bifurcation stenting
Bifurcating coronary lesions are a very common challenge in interventional cardiology because of thetechnical complexity in their treatment, the risk of side branch occlusion and an overall worse outcomewhen compared to non-bifurcating lesions.
The presence of calcifications represents further complexity due to the difficulty in device delivery andstent expansion as well as enhanced risk of side branch occlusion.
Rotational and orbital atherectomy, scoring and cutting balloons, coronary lithoplasty are available toolswhich have been introduced over the last three decades to overcome such issue. Nevertheless, their application in different contexts of bifurcations presents specific caveats and the studies directed at comparing such techniques have never been expressly oriented in the subset of the bifurcating lesion.
In this paper, we review these devices and their usefulness in bifurcations by analyzing consistent datafrom clinical trials, and we propose a practical algorithm for the treatment of severely calcified bifurcatinglesions according to their anatomical features
Bone health management in the continuum of prostate cancer disease: a review of the evidence with an expert panel opinion
Bone health impairment is a frequent detrimental consequence of the high bone tropism of prostate cancer (PCa) cells. It is further worsened by administration of androgen-deprivation therapy (ADT), the current standard of care in the management of advanced PCa, through a rapid and dramatic increase in bone turnover and body mass changes. As a result, patients may experience substantial pain and poor quality of life (QoL) and have an increased risk of death. Notwithstanding the importance of this issue, however, bone health preservation is not yet a widespread clinical goal in daily practice.To address this urgent unmet need, following a thorough discussion of available data and sharing of their clinical practice experience, a panel of Italian experts in the field of bone health and metabolism formulated a number of practical advices for optimising the monitoring and treatment of bone health in men undergoing ADT during all phases of the disease. The rationale behind the venture was to raise awareness on the importance of bone preservation in this complex setting, while providing an instrument to support physicians and facilitate the management of bone health.Current evidence regarding the effects on bone health of ADT, of novel hormone therapies (which improve progression delay, pain control and QoL while consistently carrying the risk of non-pathological fractures in both non-metastatic and metastatic PCa) and of bone turnover inhibitors (whose use is frequently suboptimal) is reviewed. Finally, the expert opinion to optimise bone health preservation is given
Analysis of a Cardiac-Necrosis-Biomarker Release in Patients with Acute Myocardial Infarction via Nonlinear Mixed-Effects Models
The release of the cardiac troponin T (cTnT) in patients with acute myocardial infarc tion (AMI) has been analyzed through a methodology based on nonlinear mixed-effects (NME)
models. The aim of this work concerns the investigation of any possible relationship between clin ical covariates and the dynamics of the release of cTnT to derive more detailed and useful clinical
information for the correct treatment of these patients. An ad-hoc mechanistic model describing
the biomarker release process after AMI has been devised, assessed, and exploited to evaluate the im pact of the available clinical covariates on the cTnT release dynamic. The following approach was
tested on a preliminary dataset composed of a small number of potential clinical covariates: em ploying an unsupervised approach, and despite the limited sample size, dyslipidemia, a known risk
factor for cardiovascular disease, was found to be a statistically significant covariate. By increasing
the number of covariates considered in the model, and patient cohort, we envisage that this approach
may provide an effective means to automatically classify AMI patients and to investigate the role
of interactions between clinical covariates and cTnT relea
The GLP-1 receptor agonists exenatide and liraglutide activate Glucose transport by an AMPK-dependent mechanism
Additional file 2: Figure S2. Effects of EXE on Glut-4 in cultured L6 myotubes. Myotubes were stimulated with 100 nmol/l EXE for 20 min or 48 h. Panel A shows qPCR of Glut-4 mRNA. In panel B is a representative western blot for Glut-4 and β-Actin (loading control). In panel C is a representative western blot for Glut-4 and β-IR (loading control) in plasma membrane (PM) extracts (Glut-4 translocation). For A and C panels, data are shown as fold increase over control ± SD of three independent experiments (*p < 0.001, vs Ctrl)
Toll like receptor signaling in "inflammaging": microRNA as new players.
none7nopubblicazione scientificaopenOlivieri F; Rippo MR; Prattichizzo F; Babini L; Graciotti L; Recchioni R; Procopio ADOlivieri, Fabiola; Rippo, Maria Rita; Prattichizzo, Francesco; Babini, Lucia; Graciotti, Laura; Recchioni, R; Procopio, Antonio Domenic
Blood CXCR3(+) CD4 T Cells Are Enriched in Inducible Replication Competent HIV in Aviremic Antiretroviral Therapy-Treated Individuals
We recently demonstrated that lymph nodes (LNs) PD-1+/T follicular helper (Tfh) cells from antiretroviral therapy (ART)-treated HIV-infected individuals were enriched in cells containing replication competent virus. However, the distribution of cells containing inducible replication competent virus has been only partially elucidated in blood memory CD4 T-cell populations including the Tfh cell counterpart circulating in blood (cTfh). In this context, we have investigated the distribution of (1) total HIV-infected cells and (2) cells containing replication competent and infectious virus within various blood and LN memory CD4 T-cell populations of conventional antiretroviral therapy (cART)-treated HIV-infected individuals. In the present study, we show that blood CXCR3-expressing memory CD4 T cells are enriched in cells containing inducible replication competent virus and contributed the most to the total pool of cells containing replication competent and infectious virus in blood. Interestingly, subsequent proviral sequence analysis did not indicate virus compartmentalization between blood and LN CD4 T-cell populations, suggesting dynamic interchanges between the two compartments. We then investi-gated whether the composition of blood HIV reservoir may reflect the polarization of LN CD4 T cells at the time of reservoir seeding and showed that LN PD-1+ CD4 T cells of viremic untreated HIV-infected individuals expressed significantly higher levels of CXCR3 as compared to CCR4 and/or CCR6, suggesting that blood CXCR3-expressing CD4 T cells may originate from LN PD-1+ CD4 T cells. Taken together, these results indicate that blood CXCR3-expressing CD4 T cells represent the major blood compartment con-taining inducible replication competent virus in treated aviremic HIV-infected individuals
The Molecular and Cellular Basis of Tumor Rejection After Vaccination With Mammary Adenocarcinoma Cells Transduced With the MHC Class II Transactivator CIITA
CD8+ T cell responses are major players of tumor eradication in various vaccination protocols. However, an optimal stimulation of CD4+ T helper cells is required for both priming and maintenance of the effector CTL response against the tumor. In this study we show that the murine mammary adenocarcinoma cell line TS/A, a highly malignant MHC-II-negative tumor, is rejected in vivo if genetically engineered to express MHC-II molecules by transfer of the MHC-II transactivator CIITA. TS/ACIITA cells are fully rejected by 93% of the syngeneic recipients and have a significantly lower growth rate in the remaining 7% of animals. Rejection requires CD4+ and CD8+ cells. CD4+ T cells are fundamental in the priming phase, whereas CTLs are the major anti-tumor effectors. All tumor rejecting animals are protected against rechallenge with the parental TS/A tumor. Immunohistochemical data at day 5 post-inoculation showed an higher infiltrate of CD4+ T cells in mice bearing TS/A-CIITA, than in mice bearing the TS/A tumor. Subsequently, from day 7 trough day 10, TS/A-CIITA tumors showed higher number of both CD4+ and CD8+ cells, dendritic cells, together with massive necrosis. The frequency of IFN-αsecreting splenocytes early after inoculations was also assessed by an ex vivo ELISPOT assay. Only the rejecting TS/A-CIITA animals showed an high frequency of IFN-αsecreting cells (between 80 and 120/106 splenocytes). Importantly, CD4 and CD8 depletion experiments revealed that at the time of tumor resolution the major cell population recognizing the TS/A-CIITA cells was of CD4 origin. This is the first example of successful tumor vaccination by genetic transfer of CIITA. These results open the way to a possible use of CIITA for increasing both the inducing and the effector phase of the anti-tumor response. from 2005 International Meeting of The Institute of Human Virology Baltimore, USA, 29 August – 2 September 200
- …