700 research outputs found
d=4 Attractors, Effective Horizon Radius and Fake Supergravity
We consider extremal black hole attractors (both BPS and non-BPS) for N=3 and
N=5 supergravity in d=4 space-time dimensions. Attractors for matter-coupled
N=3 theory are similar to attractors in N=2 supergravity minimally coupled to
Abelian vector multiplets. On the other hand, N=5 attractors are similar to
attractors in N=4 pure supergravity, and in such theories only 1\N-BPS
non-degenerate solutions exist. All the above mentioned theories have a simple
interpretation in the first order (fake supergravity) formalism. Furthermore,
such theories do not have a d=5 uplift. Finally we comment on the "duality"
relations among the attractor solutions of N\geq2 supergravities sharing the
same full bosonic sector.Comment: 1+47 pages, 2 Tables. v2: Eqs. (2.3),(2.4) and Footnote 3 added;
minor cosmetic changes; to appear in PR
Paracrine mechanisms of stem cell reparative and regenerative actions in the heart
Stem cells play an important role in restoring cardiac function in the damaged heart. In order to mediate repair, stem cells need to replace injured tissue by differentiating into specialized cardiac cell lineages and/or manipulating the cell and molecular mechanisms governing repair. Despite early reports describing engraftment and successful regeneration of cardiac tissue in animal models of heart failure, these events appear to be infrequent and yield too few new cardiomyocytes to account for the degree of improved cardiac function observed. Instead, mounting evidence suggests that stem cell mediated repair takes place via the release of paracrine factors into the surrounding tissue that subsequently direct a number of restorative processes including myocardial protection, neovascularization, cardiac remodeling, and differentiation. The potential for diverse stem cell populations to moderate many of the same processes as well as key paracrine factors and molecular pathways involved in stem cell-mediated cardiac repair will be discussed in this review. This article is part of a special issue entitled, "Cardiovascular Stem Cells Revisited"
Product Differentiation Costs and Global Competition
The growing competitive intensity on the markets determines the emergence of
competition costs that are expressed at a corporate level and have implicit
repercussions for the supply system. This type of costs makes it possible to identify
a close link between competition costs and supply differentiation costs.
Classification by competitive intensity presupposes that the analysis performed
identifies the classification of company costs as the discriminating element, in
terms of the competitive pressure of the context in which the firm operates.
The emergence of competition costs is linked to an attempt to squeeze them as an
aspect of vertical, or more specifically, horizontal cooperation strategies.Product Differentiation; Differentiation Costs; Over-Supply; Global Competition; Marketing; Market-Driven Management; Global Corporations; Global Markets DOI:http://dx.doi.org/10.4468/2005.1.06garbelli
Secreted frizzled related protein 2 (Sfrp2) is the key Akt-mesenchymal stem cell-released paracrine factor mediating myocardial survival and repair
Stem cell therapy has emerged as a promising tool for the treatment of a variety of diseases. Previously, we have shown that Akt-modified mesenchymal stem cells mediate tissue repair through paracrine mechanisms. Using a comprehensive functional genomic strategy, we show that secreted frizzled related protein 2 (Sfrp2) is the key stem cell paracrine factor that mediates myocardial survival and repair after ischemic injury. Sfrp2 is known to modulate Wnt signaling, and we demonstrate that cardiomyocytes treated with secreted frizzled related protein increase cellular beta-catenin and up-regulate expression of antiapoptotic genes. These findings reveal the key role played by Sfrp2 in mediating the paracrine effects of Akt-mesenchymal stem cells on tissue repair and identify modulation of Wnt signaling as a therapeutic target for heart disease
Complexity analyses show two distinct types of nonlinear dynamics in short heart period variability recordings
Two diverse complexity metrics quantifying time irreversibility and local prediction, in connection with a surrogate data approach, were utilized to detect nonlinear dynamics in short heart period (HP) variability series recorded in fetuses, as a function of the gestational period, and in healthy humans, as a function of the magnitude of the orthostatic challenge. The metrics indicated the presence of two distinct types of nonlinear HP dynamics characterized by diverse ranges of time scales. These findings stress the need to render more specific the analysis of nonlinear components of HP dynamics by accounting for different temporal scales
Early Complete Revascularization in Hemodynamically Stable Patients With ST-Segment Elevation Myocardial Infarction and Multivessel Disease
Serum uric acid may modulate the inflammatory response after primary percutaneous coronary intervention in patients with ST-elevation myocardial infarction
Barriers associated with emergency medical service activation in Italian patients with ST-segment elevation acute coronary syndromes
Abstract
Background
Many ST-segment elevation acute coronary syndrome (STEACS) patients fail to activate the Emergency Medical System (EMS), with possible dramatic consequences. Prior studies focusing on barriers to EMS activation include patients with any acute coronary syndrome (ACS) without representation of southern European populations. However, barriers are influenced by the ACS type and by socio-demographic and racial factors.
Purpose
We aimed to investigate the barriers to EMS call for patients diagnosed for STEACS in Italy.
Methods
A prospective, single-center, survey-based study, including all the patients treated with primary percutaneous coronary intervention for STEACS in a tertiary hospital in northern Italy from 1st June 2018 to 31st May 2020.
Results
The questionnaire was filled out by 293 patients. The majority of the participants were males (74%), married (70.4%), with a high-school degree (38.4%) and with a median age of 62 years. Chest pain as a possible symptom related to a cardiovascular attack is known by most of the respondents (89%), and left arm pain/shake by 53.7% of them, whilst the other possible signs and symptoms (i.e. dyspnea, asthenia, sweating, nausea, vomiting, dizziness) were unknown to the majority of the participants. Only 191 (65.2%) of the participants activated the EMS after symptoms onset. The main reasons for not calling EMS were the perception that symptoms were not related to an important health problem (45.5%) and that a private vehicle is faster than EMS to reach the hospital (34.7%). The median time to first medical contact was 60 minutes, and it was significantly higher in the patients who did not called EMS compared to those who did (180 [60–420] mins vs 35 [15–120] mins, p<0.001). The patients who called a private doctor after symptoms onset did not called EMS more frequently than those who did not (5.9% vs 8.2%, p=0.3). Moreover, 30% of the patients who did not call the EMS would still act in the same way if a new episode occurred and the main reasons for this were that they think to be faster than EMS (57.1%) and to live close to the hospital (17.9%). Analyzing predictors of EMS activation, only prior history of cardiovascular disease has been demonstrated to be a predictor of calling the EMS in case of symptoms suspected for STEACS.
Conclusions
Our study, from the southern Europe, showed that a substantial percentage of patients with symptoms suspected for STEACS preferred private vehicle rather than activating the EMS. Our results highlight the need for information campaigns targeted to both the general population and medical doctors, stressing that the EMS is faster than a private vehicle to direct the patient to the right hospital and increasing the awareness of the people on the type of possible heart attack symptoms, which seem to be the most neglected issues by patients who did not call the EMS.
Funding Acknowledgement
Type of funding sources: None
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