1,720 research outputs found
Succor System and Failure Indication for the Starter Batteries of Emergency Gensets
Nowadays there are 3 % of missed start-ups of emergency gensets in Italian hospitals every year. The subject of this work is the analysis of the failure to start an emergency genset due to the failure of the batteries. The work is based on ten years statistics of maintenance on hospital facilities. A real case study is here described; measurements were made on a 1000 kVA genset of a hospital to study the real operating conditions of the system. The whole electrical, mechanical and dynamic model of the starter system of a genset is studied. Computer simulations for this study are based on the Matlab/Simulink model of the considered starter system. An automatic system of parallel between the batteries of different generators is presented as a solution to the problem. This system can also indicate to the maintenance technician the need to replace a partially deteriorated battery in a timely manner. It is also proved that it is possible to succor the failed battery instantly without losing the first part of the starting transient. The work demonstrates that the failure to start, due to a fault in the batteries, can be significantly reduced by using the proposed solution. With this technical proposal the risk of blackouts and relative human losses are largely reduced
Dexamethasone in acute cardiopulmonary syndrome with hyperinflammatory state
Abstract
Introduction
Elderly patient hospitalized due to acute heart failure often have a concomitant acute lung disease (acute bronchitis, pneumonia, chronic obstructive pulmonary disease-COPD- exacerbation). Establishing the role of each disease in a clinical picture of acute cardiopulmonary syndrome can be challenging. Procalcitonin has been used as a guide to antibiotic therapy with contrasting results. A common thread of these diseases is inflammation; a hyperinflammatory response determines more serious symptoms and a worse prognosis.
Purpose
We evaluated the effectiveness of a treatment with dexamethasone in patients with acute cardiopulmonary syndrome and a strong inflammatory response.
Materials and methods
We evaluated 157 consecutive HFPEF (heart failure with preserved ejection fraction) patients ≥80 years of age, with concomitant symptoms attributable to acute bronchitis, pneumonia, or COPD exacerbation, hospitalized due to worsening dyspnoea, with an NT-proBNP ≥3,000 pg/ml, and a finding X-ray of lung congestion with or without a consolidation. Reactive C Protein was measured. Patients with SARS-CoV-2, indication to corticosteroids use for other clinical conditions or need for mechanical ventilation were excluded. The 96 patients with values>20 mg/dl were randomized into 2 groups: 48 patients were treated open-label with dexamethasone at a dose of 8 mg iv/day for a maximun of ten days, in addition to the usual therapies for acute heart failure and lung disease, while the same number of patients were treated with the usual therapy. In both groups the antibiotic was administered only if the procalcitonin was≥0.25 μg/L. Clinical recovery time, length of hospitalization, in-hospital mortality, the need for a new hospitalization and mortality at one month were evaluated.
Results
The mean age of the patients was 88±4 years in the dexamethasone group and 87±5 in the usual therapy group. The results are shown in Table 1. Patients treated with dexamethasone experienced a faster clinical recovery and a shorter length of hospitalization. No significant differences were found regarding either in-hospital mortality or need for rehospitalization and mortality at 30 days.
Conclusions
Very elderly patients with acute cardiopulmonary syndrome and hyperinflammatory state associated with an excessive increase in Reactive Protein C have a favorable response to dexamethasone therapy in addition to the usual therapy in terms of clinical improvement and length of hospitalization. Our case history is small to evaluate a possible improvement in mortality. These findings need to be consolidated from double-blind randomized controlled trials
Funding Acknowledgement
Type of funding sources: None. Table
Transantarctic Mountain microtektites: New petrographic data, water content, and Nd and Sr isotopic composition
A stochastic approach to LCA of internal insulation solutions for historic buildings
Internal insulation is a typical renovation solution in historic buildings with valuable facades. However, it entails moisture-related risks, which affect the durability and life-cycle environmental performance. In this context, the EU project RIBuild developed a risk assessment method for both hygrothermal and life-cycle performance of internal insulation, to support decision-making. This paper presents the stochastic Life Cycle Assessment method developed, which couples the LCA model to a Monte-Carlo simulation, providing results expressed by probability distributions. It is applied to five insulation solutions, considering different uncertain input parameters and building heating scenarios. In addition, the influence of data variability and quality on the result is analyzed, by using input data from two sources: distributions derived from a generic Life Cycle Inventory database and "deterministic" data from Environmental Product Declarations. The outcomes highlight remarkable differences between the two datasets that lead to substantial variations on the systems performance ranking at the production stage. Looking at the life-cycle impact, the general trend of the output distributions is quite similar among simulation groups and insulation systems. Hence, while a ranking of the solutions based on a "deterministic" approach provides misleading information, the stochastic approach provides more realistic results in the context of decision-making
VLBI studies of DAGN and SMBHB hosting galaxies
Dual active galactic nuclei (DAGN) and supermassive black hole binaries
(SMBHBs) at kpc and pc-scale separations, respectively, are expected during
stages of galaxy merger and evolution. Their observational identification can
address a range of areas of current astrophysics frontiers including the final
parsec problem and their contribution towards the emission of low-frequency
gravitational waves. This has however been difficult to achieve with current
spectroscopy and time domain strategies. Very long baseline interferometry
(VLBI) as a method of directly imaging radio structures with milli-arcsecond
(mas) and sub-mas resolutions is introduced as a possible means of detecting
DAGN and SMBHBs. We motivate its usage with expected observational signatures
and cite some studies from literature to illustrate its current status, and
present an updated list of candidates imaged with high-resolution radio
observations. We then recall some shortcomings of the method with possible
solutions and discuss future directions, relevant to large surveys with the
upcoming Square Kilometer Array and future space VLBI missions.Comment: 13 pages, 2 table; Radio Science (accepted
Metallo-Dielectric Multilayer Structure for Lactose Malabsorption Diagnosis through H2 Breath Test
A metallo-dielectric multilayer structure is proposed as a novel approach to
the analysis of lactose malabsorption. When lactose intolerance occurs, the
bacterial overgrowth in the intestine causes an increased spontaneous emission
of H2 in the human breath. By monitoring the changes in the optical properties
of a multilayer palladium-polymeric structure, one is able to detect the
patient's disease and the level of lactose malabsorption with high sensitivity
and rapid response
Frontiers in Pigment Cell and Melanoma Research
We identify emerging frontiers in clinical and basic research of melanocyte
biology and its associated biomedical disciplines. We describe challenges and
opportunities in clinical and basic research of normal and diseased melanocytes
that impact current approaches to research in melanoma and the dermatological
sciences. We focus on four themes: (1) clinical melanoma research, (2) basic
melanoma research, (3) clinical dermatology, and (4) basic pigment cell
research, with the goal of outlining current highlights, challenges, and
frontiers associated with pigmentation and melanocyte biology. Significantly,
this document encapsulates important advances in melanocyte and melanoma
research including emerging frontiers in melanoma immunotherapy, medical and
surgical oncology, dermatology, vitiligo, albinism, genomics and systems
biology, epidemiology, pigment biophysics and chemistry, and evolution
Tumor-derived exosomes confer antigen-specific immunosuppression in a murine delayed-type hypersensitivity model
Exosomes are endosome-derived small membrane vesicles that are secreted by most cell types including tumor cells. Tumor-derived exosomes usually contain tumor antigens and have been used as a source of tumor antigens to stimulate anti-tumor immune responses. However, many reports also suggest that tumor-derived exosomes can facilitate tumor immune evasion through different mechanisms, most of which are antigen-independent. In the present study we used a mouse model of delayed-type hypersensitivity (DTH) and demonstrated that local administration of tumor-derived exosomes carrying the model antigen chicken ovalbumin (OVA) resulted in the suppression of DTH response in an antigen-specific manner. Analysis of exosome trafficking demonstrated that following local injection, tumor-derived exosomes were internalized by CD11c+ cells and transported to the draining LN. Exosome-mediated DTH suppression is associated with increased mRNA levels of TGF-β1 and IL-4 in the draining LN. The tumor-derived exosomes examined were also found to inhibit DC maturation. Taken together, our results suggest a role for tumor-derived exosomes in inducing tumor antigen-specific immunosuppression, possibly by modulating the function of APCs. © 2011 Yang et al
Chandra Observations of Candidate Subparsec Binary Supermassive Black Holes
We present analysis of Chandra X-ray observations of seven quasars that were identified as candidate subparsec binary supermassive black hole (SMBH) systems in the Catalina Real-Time Transient Survey based on the apparent periodicity in their optical light curves. Simulations predict that close-separation accreting SMBH binaries will have different X-ray spectra than single accreting SMBHs, including harder or softer X-ray spectra, ripple-like profiles in the Fe K-α line, and distinct peaks in the spectrum due to the separation of the accretion disk into a circumbinary disk and mini disks around each SMBH. We obtained Chandra observations to test these models and assess whether these quasars could contain binary SMBHs. We instead find that the quasar spectra are all well fit by simple absorbed power-law models, with the rest-frame 2–10 keV photon indices, Γ, and the X-ray-to-optical power slopes, α_(OX), indistinguishable from those of the larger quasar population. This may indicate that these seven quasars are not truly subparsec binary SMBH systems, or it may simply reflect that our sample size was too small to robustly detect any differences. Alternatively, the X-ray spectral changes might only be evident at energies higher than probed by Chandra. Given the available models and current data, no firm conclusions are drawn. These observations will help motivate and direct further work on theoretical models of binary SMBH systems, such as modeling systems with thinner accretion disks and larger binary separations
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