1,722,137 research outputs found
La spettroscopia Raman nella diagnostica dei Beni Culturali: esempio di applicazione alla caratterizzazione degli affreschi conservati nella Chiesa di Sant’Agostino a Siena
No full textThe 'Madonna and Child Enthroned with Saints' of Ambrogio Lorenzetti in the St. Augustine Church (Siena, Italy): Raman microspectroscopy and SEM-EDS characterisation of the pigments
No full textRaman microspectroscopy combined with scanning electron microscopy was applied to the investigation of the Madonna and Child Enthroned with Saints of Ambrogio Lorenzetti (early 14th century; St. Augustine church, Siena, Italy). A detailed investigation of both the materials used for the wall painting and the alteration products was provided in order to increase the level of accessibility of this masterpiece and to stimulate its restoration. The results showed that the pigments used for this wall painting were those widely used by medieval painters: chalk white, white lead, yellow ochre, red ochre, red lead, cinnabar, Siena earth, green earth, verdigris, azurite, and carbon black. Gilded tin foil has been further used for the decoration of the haloes. The alteration products mainly consist of Ca sulfates and Ca oxalates. Fungal spores were further observed in correspondence to the application of lead-based pigments. © 2014, Springer-Verlag Berlin Heidelberg
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Clay mineral fluctuations and surface textural analysis of quartz grains in Pliocene-Quaternary marine sediments from Wilkes Land continental rise (East-Antarctica): Palaeoenvironmental significance
No full textPliocene-Quaternary marine sediments from Wilkes Land continental rise were investigated using clay mineral analysis and quartz grain surface texture observations. The studied piston cores were collected during a geophysical and geological survey in the framework of the Italian and Australian WEGA Project. The cores were collected along two transects crossing the channel-mound system that characterizes the Wilkes Land continental rise. Massive and laminated facies were recognized in these sedimentary sequences. The clay mineral assemblages are dominated by illite. Smectite and chlorite occur in intermediate amounts, whereas kaolinite is scarce. Illite derives from the hinterland of the Mertz and Ninnis glaciers. Smectite and kaolinite derive from the Ross Sea area and they are transported by westward marine bottom currents. Chlorite is derived both from the adjacent continent and from the Victoria Land. Different concentrations of individual clay minerals in the massive and laminated facies are controlled by the interplay between different source areas and the main sedimentary processes. Glacial and eolian quartz grains prevail in the massive units indicating short transportation and rapid deposition from melting ices, with no further significant transport action by marine currents. In the laminated facies the high amount of quartz grains affected by high-energy subaqueous transport features are related both to turbiditic processes and to bottom current transport. © 2005 Elsevier B.V. All rights reserved
Advancing Chimeric Antigen Receptor T-Cell Therapy for Acute Myeloid Leukemia: Current Limitations and Emerging Strategies
Full text linkChimeric antigen receptor (CAR) T-cell therapy represents one of the most impressive advances in anticancer therapy of the last decade. While CAR T-cells are gaining ground in various B cell malignancies, their use in acute myeloid leukemia (AML) remains limited, and no CAR-T product has yet received approval for AML. The main limitation of CAR-T therapy in AML is the lack of specific antigens that are expressed in leukemic cells but not in their healthy counterparts, such as hematopoietic stem cells (HSCs), as their targeting would result in an on-target/off-tumor toxicity. Moreover, the heterogeneity of AML and the tendency of blasts to modify surface antigens’ expression in the course of the disease make identification of suitable targets even more challenging. Lastly, AML’s immunosuppressive microenvironment dampens CAR-T therapeutic activities. In this review, we focus on the actual pitfalls of CAR T-cell therapy in AML, and we discuss promising approaches to overcome them
Present and Future Role of Immune Targets in Acute Myeloid Leukemia
Full text linkIt is now well known that the bone marrow (BM) cell niche contributes to leukemogenesis, but emerging data support the role of the complex crosstalk between AML cells and the BM microenvironment to induce a permissive immune setting that protects leukemic stem cells (LSCs) from therapy-induced death, thus favoring disease persistence and eventual relapse. The identification of potential immune targets on AML cells and the modulation of the BM environment could lead to enhanced anti-leukemic effects of drugs, immune system reactivation, and the restoration of AML surveillance. Potential targets and effectors of this immune-based therapy could be monoclonal antibodies directed against LSC antigens such as CD33, CD123, and CLL-1 (either as direct targets or via several bispecific T-cell engagers), immune checkpoint inhibitors acting on different co-inhibitory axes (alone or in combination with conventional AML drugs), and novel cellular therapies such as chimeric antigen receptor (CAR) T-cells designed against AML-specific antigens. Though dozens of clinical trials, mostly in phases I and II, are ongoing worldwide, results have still been negatively affected by difficulties in the identification of the optimal targets on LSCs
ATP-Binding Cassette Subfamily G Member 2 in Acute Myeloid Leukemia: A New Molecular Target?
Full text linkDespite the progress in the knowledge of disease pathogenesis and the identification of many molecular markers as potential targets of new therapies, the cure of acute myeloid leukemia remains challenging. Disease recurrence after an initial response and the development of resistance to old and new therapies account for the poor survival rate and still make allogeneic stem cell transplantation the only curative option. Multidrug resistance (MDR) is a multifactorial phenomenon resulting from host-related characteristics and leukemia factors. Among these, the overexpression of membrane drug transporter proteins belonging to the ABC (ATP-Binding Cassette)-protein superfamily, which diverts drugs from their cellular targets, plays an important role. Moreover, a better understanding of leukemia biology has highlighted that, at least in cancer, ABC protein’s role goes beyond simple drug transport and affects many other cell functions. In this paper, we summarized the current knowledge of ABCG2 (formerly Breast Cancer Resistance Protein, BCRP) in acute myeloid leukemia and discuss the potential ways to overcome its efflux function and to revert its ability to confer stemness to leukemia cells, favoring the persistence of leukemia progenitors in the bone marrow niche and justifying relapse also after therapy intensification with allogeneic stem cell transplantation
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