1,228 research outputs found
A multi-family GLRT for detection in polarimetric SAR images
This paper deals with detection from multipolarization SAR images. The problem is cast in terms of a composite hypothesis test aimed at discriminating between the Polarimetric Covariance Matrix (PCM) equality (absence of target in the tested region) and the situation where the region under test exhibits a PCM with at least an ordered eigenvalue smaller than that of a reference covariance. This last setup reflects the physical condition where the back scattering associated with the target leads to a signal, in some eigen-directions, weaker than the one gathered from a reference area where it is apriori known the absence of targets. A Multi-family Generalized Likelihood Ratio Test (MGLRT) approach is pursued to come up with an adaptive detector ensuring the Constant False Alarm Rate (CFAR) property. At the analysis stage, the behaviour of the new architecture is investigated in comparison with a benchmark (but non-implementable) and some other adaptive sub-optimum detectors available in open literature. The study, conducted in the presence of both simulated and real data, confirms the practical effectiveness of the new approach
A joint coregistration of rotated multitemporal SAR images based on the cross-cross-correlation
Accurate synthetic aperture radar (SAR) images coregistration is on the base of several remote sensing applications, such as interferometry, change detection, etc. This paper proposes a new algorithm for jointly coregister a stack of multitemporal SAR images exploiting the cross-correlations computed for each couple of patches' cross-correlation. By doing so, the method is capable of exploit also the respective misregistration information between the slave during the estimation process. This methodology is applied to improve the performance of the constrained Least Squares (CLS) optimization method that does not account for the reciprocal information related to the slaves. Tests on real-recorded data shown the benefits of the proposed method in terms of root mean square error (RMSE) for images affected by respective rotations
Modulation of Toll-like receptors in psoriatic patients during therapy with adalimumab
Toll-like receptors (TLRs) are a key part of the innate immune system that detect pathogen-associated molecular patterns (PAMPs) of microorganisms and their stimulation results in the activation of signaling pathways leading to the modulation of inflammatory and immune responses. Since psoriasis is a complex, inflammatory and immune skin disease, characterized by an abnormal immune response and increased proliferation of keratinocytes, with an increased production of proinflammatory cytokines, TLRs could play an important role in the pathogenesis of the disease. We propose to assess the modulation of TLR expression on psoriatic skin of patients treated with Adalimumab and systemic conventional therapies. We therefore recruited fifteen patients: ten were treated with adalimumab and five with systemic conventional therapies; their clinical conditions were analyzed by PASI index and skin biopsies were evaluated for TLR1 and TLR2 expression by immunohistochemistry assays. Our data suggest adalimumab is not only able to improve the clinical condition of psoriatic patients, but also to modulate TLR1 and TLR2 expression involved in psoriasis, as in healthy skin. Adalimumab is a most promising biological drug able to orchestrate immune and inflammatory responses in psoriatic lesions, recovering TLR expression on basal keratinocytes and improving clinical conditions of psoriatic patients, with no evident side effects
EFSUMB Recommendations and Guidelines for Gastrointestinal Ultrasound - Part 1: Examination Techniques and Normal Findings (Short version)
Abstract
â–Ľ
In October 2014 the European Federation of Societies
for Ultrasound in Medicine and Biology formed
a Gastrointestinal Ultrasound (GIUS) task force
group to promote the use of GIUS in a clinical setting.
One of the main objectives of the task force
group was to develop clinical recommendations
and guidelines for the use of GIUS under the auspices
of EFSUMB. The first part, gives an overview of
the examination techniques for GIUS recommended
by experts in the field. It also presents the
current evidence for the interpretation of normal
sonoanatomical and physiological features as examined
with different ultrasound modalities
EFSUMB Recommendations and Guidelines for Gastrointestinal Ultrasound - Part 1: Examination Techniques and Normal Findings (Long version).
Abstract
â–Ľ
In October 2014 the European Federation of Societies
for Ultrasound in Medicine and Biology formed
a Gastrointestinal Ultrasound (GIUS) task force
group to promote the use of GIUS in a clinical setting.
One of the main objectives of the task force
group was to develop clinical recommendations
and guidelines for the use of GIUS under the auspices
of EFSUMB. The first part, gives an overview of
the examination techniques for GIUS recommended
by experts in the field. It also presents the
current evidence for the interpretation of normal
sonoanatomical and physiological features as examined
with different ultrasound modalities
Methods and advanced Equipment for Simulation and Treatment in Radiation Oncology: programa MAESTRO
n/
Unusual Skin Toxicity after a Chemotherapic Combination
As known calciphylaxis (CPX) is a rare condition involving
subcutaneous vascular calcification and cutaneous necrosis, mostly
observed in patients with renal failure. However CPX may also
appear in patients affected by polymyositis, Sjogren syndrome, Lupus
Erythematosus systemicus, Sarcoidosis and rheumatoid arthritis,
especially in children. Clinically CPX can present itself as subcutaneous
nodules, infiltrate plaques or purpuric-like and livedo-like plaques,
while in the late stages necrotic ulcers (with a bizarre shape and severe
pain) may be the main cutaneous manifestations
Risk of Drop-Out from Follow-Up Evaluations for Celiac Disease: Is It Similar for All Patients?
Background: Celiac disease (CD) follow-up is a relatively underevaluated topic. However, correct adherence to follow-up procedures is central to the early recognition of complicated CD and other conditions typically associated with CD. Establishing whether patients at increased risk of complications follow clinicians’ recommendations has multiple repercussions. Methods: We retrospectively analyzed the records of patients consecutively diagnosed with CD in our outpatient clinic between January 2004 and October 2017 to investigate the factors associated with drop-out from follow-up procedures. Results: Among the 578 patients analyzed, 40 (6.9%) dropped out during the first six months and 272 (50.6%) during the observation period. The median time to drop-out was 7.4 years (95% confidence interval: 6.8–8.0). No factors were associated with early drop-out. Instead, age at diagnosis >40 years (40–59 years, p < 0.001; ≥60 years, p = 0.048) and classical clinical presentation (p = 0.016) were significantly associated with a lower risk of later drop-out. Conclusions: Patients at increased risk of complicated CD are more compliant with follow-up procedures than patients at lower risk, despite being prescribed the same controls. These results indirectly support the hypothesis of tailored follow-up strategies, differentiated according to the risk of complications
The RCK2 domain of the human BKCa channel is a calcium sensor
Large conductance voltage and Ca2+-dependent K+ channels (BKCa) are activated by both membrane depolarization and intracellular Ca2+. Recent studies on bacterial channels have proposed that a Ca2+-induced conformational change within specialized regulators of K+ conductance (RCK) domains is responsible for channel gating. Each pore-forming α subunit of the homotetrameric BKCa channel is expected to contain two intracellular RCK domains. The first RCK domain in BKCa channels (RCK1) has been shown to contain residues critical for Ca2+ sensitivity, possibly participating in the formation of a Ca2+-binding site. The location and structure of the second RCK domain in the BKCa channel (RCK2) is still being examined, and the presence of a high-affinity Ca2+-binding site within this region is not yet established. Here, we present a structure-based alignment of the C terminus of BKCa and prokaryotic RCK domains that reveal the location of a second RCK domain in human BKCa channels (hSloRCK2). hSloRCK2 includes a high-affinity Ca2+-binding site (Ca bowl) and contains similar secondary structural elements as the bacterial RCK domains. Using CD spectroscopy, we provide evidence that hSloRCK2 undergoes a Ca2+-induced change in conformation, associated with an α-to-β structural transition. We also show that the Ca bowl is an essential element for the Ca2+-induced rearrangement of hSloRCK2. We speculate that the molecular rearrangements of RCK2 likely underlie the Ca2+-dependent gating mechanism of BKCa channels. A structural model of the heterodimeric complex of hSloRCK1 and hSloRCK2 domains is discussed
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