1,658 research outputs found
THE DEEP STRUCTURE OF THE L'AQUILA BASIN INVESTIGATED USING ARRAY MEASUREMENTS
We present velocity profiles obtained through surface-wave methods in the historical city of L’Aquila (Italy). The city suffered severe damage (VIII-IX EMS intensity) during the April 6th 2009 Mw 6.3 earthquake. The area is characterized by the deep (up to 300-400 meters) basin of the Aterno river valley filled by lacustrine sediments over limestone bedrock. In downtown L'Aquila an outcropping unit basically composed of stiff conglomerates (Breccia) is over-imposed to ancient lacustrine sediments with a possible velocity
inversion at a depth ranging from few tens up to one hundred meters. We deployed five 2-D arrays of seismic stations and 1-D array
of vertical geophones in the city center. The 2-D arrays recorded ambient noise, whereas the 1-D array recorded signals produced by active sources. Surface-wave dispersion and spatial autocorrelation curves, calculated using array methods, were inverted through a neighborhood algorithm jointly with the microtremor HVNSR ellipticity. We obtain shear-wave velocity profiles (Vs) representative of the southern and northern sector of downtown L'Aquila. The resulting Vs profiles are used to compare the 1-D transfer functions to
aftershock data results. We apply a convolution approach evaluating synthetic time-histories in sites where surface stratigraphy is known and comparing them to recorded strong-motion data
Electron Heating and Cosmic Rays at a Supernova Shock from Chandra X-ray Observations of E0102.2-7219
In this Letter we use the unprecedented spatial resolution of the Chandra
X-ray Observatory to carry out, for the first time, a measurement of the
post-shock electron temperature and proper motion of a young SNR, specifically
to address questions about the post-shock partition of energy among electrons,
ions, and cosmic rays. The expansion rate, 0.100 +/- 0.025 percent per yr, and
inferred age, ~1000 yr, of E0102.2-7219, from a comparison of X-ray
observations spanning 20 years, are fully consistent with previous estimates
based on studies of high velocity oxygen-rich optical filaments in the remnant.
With a radius of 6.4 pc for the blast wave estimated from the Chandra image,
our expansion rate implies a blast wave velocity of ~6000 km/s and a range of
electron temperatures 2.5 - 45 keV, dependent on the degree of collisionless
electron heating. Analysis of the Chandra ACIS spectrum of the immediate
post-shock region reveals a thermal plasma with abundances and column density
typical of the Small Magellanic Cloud and an electron temperature of 0.4-1 keV.
The measured electron temperature is significantly lower than the plausible
range above, which can only be reconciled if we assume that a significant
fraction of the shock energy, rather than contributing to the heating of the
post-shock electrons and ions, has gone into generating cosmic rays.Comment: 13 pages, including 2 postscript figs, LaTeX. Accepted by Ap
Integrated multi-omics investigations of metalloproteinases in colon cancer: Focus on MMP2 and MMP9
Colorectal cancer (CRC) develops by genetic and epigenetic alterations. However, the molecular mechanisms underlying metastatic dissemination remain unclear and could benefit from multi-omics investigations of specific protein families. Matrix metalloproteinases (MMPs) are proteolytic enzymes involved in ECM remodeling and the processing of bioactive molecules. Increased MMP expression promotes the hallmarks of tumor progression, including angiogenesis, invasion, and metastasis, and is correlated with a shortened survival. Nevertheless, the collective role and the possible coordination of MMP members in CRC are poorly investigated. Here, we performed a multi-omics analysis of MMP expression in CRC using data mining and experimental investigations. Several databases were used to deeply mine different expressions between tumor and normal tissues, the genetic and epigenetic alterations, the prognostic value as well as the interrelationships with tumor immune-infiltrating cells (TIICs). A special focus was placed on to MMP2 and MMP9: their expression was correlated with immune markers and the interaction network of co-expressed genes disclosed their implication in epithelial to mesenchymal transition (EMT) and immune response. Finally, the activity levels of MMP2 and MMP9 in a cohort of colon cancer samples, including tissues and the corresponding sera, was also investigated by zymography. Our findings suggested that MMPs could have a high potency, as they are targeted in colon cancer, and might serve as novel biomarkers, especially for their involvement in the immune response. However, further studies are needed to explore the detailed biological functions and molecular mechanisms of MMPs in CRC, also in consideration of their expression and different regulation in several tissues
Retrospective Proteomic Screening of 100 Breast Cancer Tissues
The present investigation has been conducted on one hundred tissue fragments of breast cancer, collected and immediately cryopreserved following the surgical resection. The specimens were selected from patients with invasive ductal carcinoma of the breast, the most frequent and potentially aggressive type of mammary cancer, with the objective to increase the knowledge of breast cancer molecular markers potentially useful for clinical applications. The proteomic screening; by 2D-IPG and mass spectrometry; allowed us to identify two main classes of protein clusters: proteins expressed ubiquitously at high levels in all patients; and proteins expressed sporadically among the same patients. Within the group of ubiquitous proteins, glycolytic enzymes and proteins with anti-apoptotic activity were predominant. Among the sporadic ones, proteins involved in cell motility, molecular chaperones and proteins involved in the detoxification appeared prevalent. The data of the present study indicates that the primary tumor growth is reasonably supported by concurrent events: the inhibition of apoptosis and stimulation of cellular proliferation, and the increased expression of glycolytic enzymes with multiple functions. The second phase of the evolution of the tumor can be prematurely scheduled by the occasional presence of proteins involved in cell motility and in the defenses of the oxidative stress. We suggest that this approach on large-scale 2D-IPG proteomics of breast cancer is currently a valid tool that offers the opportunity to evaluate on the same assay the presence and recurrence of individual proteins, their isoforms and short forms, to be proposed as prognostic indicators and susceptibility to metastasis in patients operated on for invasive ductal carcinoma of the breast
Synchronous versus asynchronous modeling of gene regulatory networks
Motivation: In silico modeling of gene regulatory networks has gained some momentum recently due to increased interest in analyzing the dynamics of biological systems. This has been further facilitated by the increasing availability of experimental data on gene–gene, protein–protein and gene–protein interactions. The two dynamical properties that are often experimentally testable are perturbations and stable steady states. Although a lot of work has been done on the identification of steady states, not much work has been reported on in silico modeling of cellular differentiation processes
Proteomic profiling of 13 paired ductal infiltrating breast carcinomas and non-tumoral adjacent counterparts.
According to recent statistics, breast cancer remains one of the leading causes of death among women in Western countries. Breast cancer is a complex and heterogeneous disease, presently classified into several subtypes according to their cellular origin. Among breast cancer histotypes, infiltrating ductal carcinoma represents the most common and potentially aggressive form. Despite the current progress achieved in early cancer detection and treatment, including the new generation of molecular therapies, there is still need for identification of multiparametric biomarkers capable of discriminating between cancer subtypes and predicting cancer progression for personalized therapies. One established step in this direction is the proteomic strategy, expected to provide enough information on breast cancer profiling. To this aim, in the present study we analyzed 13 breast cancer tissues and their matched non-tumoral tissues by 2-DE. Collectively, we identified 51 protein spots, corresponding to 34 differentially expressed proteins, which may represent promising candidate biomarkers for molecular-based diagnosis of breast cancer and for pattern discovery. The relevance of these proteins as factors contributing to breast carcinogenesis is discussed
Differential occurrence of S100A7 in breast cancer tissues: A proteomic-based investigation
PURPOSE: The present study reports for the first time a large-scale proteomic screening of the occurrence, subcellular localization and relative quantification of the S100A7 protein among a group of 100 patients, clinically grouped for the diagnosis of infiltrating ductal carcinoma (IDC).
EXPERIMENTAL DESIGN: To this purpose, the methods of differential proteomics, Western blotting, and immunohistochemistry were used.
RESULTS: The identity of two isoforms of the protein was assessed by mass spectrometry and immunologically confirmed. Moreover, we proved by immunocytochemical applications the exclusive localization of the protein within the neoplastic cells. The correlation of S100A7 expression levels with the collective profile of cancer patients' proteomics predicted functional interactions, distinct for the two isoforms. The S100A7b isoform was significantly correlated with specific protein clusters (calcium binding, signaling and cell motion, heat shock and folding) and intercrossing pathways (antioxidant, metabolic and apoptotic pathways), while the more acidic isoform was correlated with a narrow number of proteins mainly unrelated to the b isoform.
CONCLUSIONS AND CLINICAL RELEVANCE: This study is the first proteomic-based report on S100A7 in a large series of IDC patients. The correlation with in silico data may significantly contribute the knowledge of possible pathways for S100A7, providing novel insights into the mechanism of action of this protein. We suggest that each S100A7 isoform is involved in critical phases of the breast cancer growth and progression, probably through interaction with different partner proteins
Donor age and long-term culture do not negatively influence the stem potential of limbal fibroblast-like stem cells
In regenerative medicine the maintenance of stem cell properties is of crucial importance. Ageing is considered a cause of reduced stemness capability. The limbus is a stem niche of easy access and harbors two stem cell populations: epithelial stem cells and fibroblast-like stem cells. Our aim was to investigate whether donor age and/or long-term culture have any influence on stem cell marker expression and the profiles in the fibroblast-like stem cell population
The ARIEL Instrument Control Unit design for the M4 Mission Selection Review of the ESA's Cosmic Vision Program
The Atmospheric Remote-sensing Infrared Exoplanet Large-survey mission
(ARIEL) is one of the three present candidates for the ESA M4 (the fourth
medium mission) launch opportunity. The proposed Payload will perform a large
unbiased spectroscopic survey from space concerning the nature of exoplanets
atmospheres and their interiors to determine the key factors affecting the
formation and evolution of planetary systems. ARIEL will observe a large number
(>500) of warm and hot transiting gas giants, Neptunes and super-Earths around
a wide range of host star types, targeting planets hotter than 600 K to take
advantage of their well-mixed atmospheres. It will exploit primary and
secondary transits spectroscopy in the 1.2-8 um spectral range and broad-band
photometry in the optical and Near IR (NIR). The main instrument of the ARIEL
Payload is the IR Spectrometer (AIRS) providing low-resolution spectroscopy in
two IR channels: Channel 0 (CH0) for the 1.95-3.90 um band and Channel 1 (CH1)
for the 3.90-7.80 um range. It is located at the intermediate focal plane of
the telescope and common optical system and it hosts two IR sensors and two
cold front-end electronics (CFEE) for detectors readout, a well defined process
calibrated for the selected target brightness and driven by the Payload's
Instrument Control Unit (ICU).Comment: Experimental Astronomy, Special Issue on ARIEL, (2017
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