1,675 research outputs found
Some Results on the Boundary Control of Systems of Conservation Laws
This note is concerned with the study of the initial boundary value problem
for systems of conservation laws from the point of view of control theory,
where the initial data is fixed and the boundary data are regarded as control
functions. We first consider the problem of controllability at a fixed time for
genuinely nonlinear Temple class systems, and present a description of the set
of attainable configurations of the corresponding solutions in terms of
suitable Oleinik-type estimates. We next present a result concerning the
asymptotic stabilization near a constant state for general systems.
Finally we show with an example that in general one cannot achieve exact
controllability to a constant state in finite time.Comment: 10 pages, 4 figures, conferenc
Technical peculiarities in Giovanni Santi’s paintings on canvas
Giovanni Santi (Colbordolo ca. 1439–Urbino 1494) was one of the most important painters
active in Urbino (Marche region, Italy) during the last decades of the fifteenth century,
where he was employed at the court of the celebrated Federico da Montefeltro. He
is known mainly as the father of Raphael, but he had a remarkable production of paintings,
especially on wood but also on canvas and on wall. This paper focuses on technical peculiarities
related to Santi’s paintings on canvas, including some practices that have not yet been noted
in relation to his panel paintings. In particular, two works painted on herringbone-weave linen
canvases were investigated: Tobias and the Archangel Raphael and Saint Roch (both dated ca.
1490–94), in the collection of the Galleria Nazionale delle Marche. The results presented are a part
of a large research project based on noninvasive and micro-invasive investigations carried out
on twenty-eight works attributed to Giovanni Santi, only partially published in a recent exhibition
catalog dedicated to the artist (Palazzo Ducale, Urbino, 2018). Black underdrawing, characterized
by a thinly applied network of close hatching for some of the shadows, was observed and,
regarding the different hues, a complex use of pigments. The binder detected is siccative oil, with
the addition of a large amount of transparent glass particles, which would have been added both
to give body to the pigment without using white fillers and to improve drying, a technique that
Santi presumably learned from the Flemish painter Justus van Ghent (act. Urbino ca. 1473–1475)
and something that he possibly transmitted to his son Raphael as a workshop practice. In fact,
Giovanni Santi’s workshop survived his death
Genetic Features of Metachronous Esophageal Cancer Developed in Hodgkin's Lymphoma or Breast Cancer Long-Term Survivors: An Exploratory Study.
Background
Development of novel therapeutic drugs and regimens for cancer treatment has led to improvements in patient long-term survival. This success has, however, been accompanied by the increased occurrence of second primary cancers. Indeed, patients who received regional radiotherapy for Hodgkin's Lymphoma (HL) or breast cancer may develop, many years later, a solid metachronous tumor in the irradiated field. Despite extensive epidemiological studies, little information is available on the genetic changes involved in the pathogenesis of these solid therapy-related neoplasms.
Methods
Using microsatellite markers located in 7 chromosomal regions frequently deleted in sporadic esophageal cancer, we investigated loss of heterozygosity (LOH) and microsatellite instability (MSI) in 46 paired (normal and tumor) samples. Twenty samples were of esophageal carcinoma developed in HL or breast cancer long-term survivors: 14 squamous cell carcinomas (ESCC) and 6 adenocarcinomas (EADC), while 26 samples, used as control, were of sporadic esophageal cancer (15 ESCC and 11 EADC).
Results
We found that, though the overall LOH frequency at the studied chromosomal regions was similar among metachronous and sporadic tumors, the latter exhibited a statistically different higher LOH frequency at 17q21.31 (p = 0.018). By stratifying for tumor histotype we observed that LOH at 3p24.1, 5q11.2 and 9p21.3 were more frequent in ESCC than in EADC suggesting a different role of the genetic determinants located nearby these regions in the development of the two esophageal cancer histotypes.
Conclusions
Altogether, our results strengthen the genetic diversity among ESCC and EADC whether they occurred spontaneously or after therapeutic treatments. The presence of histotype-specific alterations in esophageal carcinoma arisen in HL or breast cancer long-term survivors suggests that their transformation process, though the putative different etiological origin, may retrace sporadic ESCC and EADC carcinogenesis
Is there any correlation between otitis media and dental malocclusion in children? A systematic review
PurposeThis study aims to evaluate whether there is a correlation between otitis and dental malocclusions.MethodsElectronic databases were searched for observational studies published until July 2021 without language or time restrictions. PROSPERO: CRD42021270760. Observational studies on children with and without OM and/or malocclusion were included. After removing duplicates and excluding not-eligible articles, two reviewers screened relevant articles independently. Two reviewers independently extracted data and assessed data quality and validity through the Newcastle-Ottawa Scale (NOS) quality assessment tool for non-randomized studies.ResultsFive studies met the selection inclusion criteria and were included in the studies for a total of 499 patients. Three studies investigated the relationship between malocclusion and otitis media, while the remaining two studies analyzed the inverse relationship and one of them considered eustachian tube dysfunction as a proxy of OM. An association between malocclusion and otitis media and vice versa emerged, although with relevant limitations.ConclusionThere is some evidence that there is an association between otitis and malocclusion; however, it is not yet possible to establish a definitive correlation
INCREASE OF REPORTS OF SUSPECTED ADVERSE DRUG REACTIONS IN ONCOLOGY
Objective: The information of safety of antineoplastic agents derives solely from clinical studies that have a number of limitations, such as the number of patients enrolled, selected case studies, follow-up of short duration; therefore, it is not possible to identify the complete profile of safety and possible side effects of the drugs under study. ADRs monitoring and reporting programmes aim to identifying and quantifying the risks associated with the use of drugs provided in a hospital setting. The main objectives of this study were to evaluate the ADRs that occurred during hospitalization for chemotherapy in 7 cancer centers, and to facilitate the development of a monitoring system of pharmacovigilance.
Methods: An observational study was conducted in 7 cancer centers in the Emilia Romagna region over a period of 2 years, from January 2012 to January 2014. This study was based on an analysis of ADRs reported. Several parameters were utilised in the data evaluation, including drug and reaction characteristics.
Results: From January 2012 to January 2014 No. 884 ADRs were included in National Network of pharmacovigilance. The highest ADR rate (57.4%) was found in the adult females with a mean age of 62. The oncology drug most frequently reported were taxanes and platinum derivates.
Conclusion: The results obtained will contribute to the development of strategies for the pharmacovigilance service in 7 cancer centers, which will improve the quality of ADR reporting and ensure safer oncology drug use
Idiopathic thrombocytopenic purpura: current concepts in pathophysiology and management.
Idiopathic thrombocytopenic purpura (ITP) is characterized by
a low platelet count, which is the result of both increased pla-
telet destruction and insufficient platelet production. Although
the development of autoantibodies against platelet glycoproteins remains central in the pathophysiology of ITP, several abnormalities involving the cellular mechanisms of immune modu-
lation have been identified. Conventional treatments for ITP aim
at reducing platelet destruction, either by immunosuppression or splenectomy. Two new thrombopoietic agents,AMG 531 and eltrombopag, have been used in clinical trials to stimulate platelet production in ITP patients not responsive to standard
treatments. These new molecules bear no structural resemblance to thrombopoietin, but still bind and activate the thrombopoietin receptor. This review will focus on the pathophysiology and treatment of ITP in adults, highlighting recent advances
in both fields
New Insight on Medieval Painting in Sicily: The Virgin Hodegetria Panel in Monreale Cathedral (Palermo, Italy)
: The Virgin Hodegetria, located in the Cathedral of Santa Maria Nuova in Monreale, near
Palermo (Italy), probably dating the first half of the 13th century, is one of the earliest examples
of medieval panel painting in Sicily. A diagnostic campaign was carried out on the panel aiming
to identify the constituting materials and the executive technique, as well as to assess the state of
conservation for supporting the methodological choice of the restoration intervention. Both non invasive (X-ray radiography, digital microscope, multispectral imaging, ED-X-ray fluorescence) and
micro-invasive (polarised light microscopy, ESEM-EDX, ATR-FTIR spectroscopy and micro-Raman
spectroscopy) analyses were performed. According to the results, the executive technique followed
the 13th–14th-century Italian painting tradition. A complex structure was applied on the wooden
support, consisting of a double layer of canvas and several ground layers of gypsum and glue based binder. The underdrawing was made by a brush using carbonaceous black pigment. The
original palette includes red ochre, red lead, azurite, carbon black and bone black. During the several
restorations, mercury-based red, indigo, smalt blue, orpiment and synthetic mars were used. The
original silver leaf of the frame was covered with red tin-based lake and subsequently regilded with
gold leaf. Proteinaceous and oil binders were also detecte
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