162 research outputs found
Idiopathic Myenteric Ganglionitis Underlying Acute âDramaticâ Intestinal Pseudoobstruction: Report of an Exceptional Case
Inflammation of the myenteric plexus of the gastrointestinal tract is a very rare pathological condition, with few reports in the medical literature. This pathological condition causes atonic gut motor dysfunction and is principally secondary to other diseases, being reported nearly solely as a paraneoplastic phenomenon in neuroendocrine lung tumors, including small cell carcinomas or neuroblastomas. In addition it can also be associated with disorders of the central nervous system, although it has rarely been described in Chagas disease. It has been named âidiopathic myenteric ganglionitisâ because no apparent causes can be demonstrated. We report the clinicopathologic findings of an exceptional case of a young woman affected by severe chronic constipation suddenly changing into acute intestinal pseudoobstruction with dramatic evolution. Relationships between ganglionitis, idiopathic constipation and acute intestinal pseudoobstruction as well as therapeutic implications are discussed
Influence of tumor microenvironment and fibroblast population plasticity on melanoma growth, therapy resistance and immunoescape
Cutaneous melanoma (CM) tissue represents a network constituted by cancer cells and tumor microenvironment (TME). A key feature of CM is the high structural and cellular plasticity of TME, allowing its evolution with disease and adaptation to cancer cell and environmental alter-ations. In particular, during melanoma development and progression each component of TME by interacting with each other and with cancer cells is subjected to dramatic structural and cellular modifications. These alterations affect extracellular matrix (ECM) remodelling, phenotypic profile of stromal cells, cancer growth and therapeutic response. The stromal fibroblast populations of the TME include normal fibroblasts and melanomaâassociated fibroblasts (MAFs) that are highly abun-dant and flexible cell types interacting with melanoma and stromal cells and differently influencing CM outcomes. The shift from the normal microenvironment to TME and from normal fibroblasts to MAFs deeply sustains CM growth. Hence, in this article we review the features of the normal mi-croenvironment and TME and describe the phenotypic plasticity of normal dermal fibroblasts and MAFs, highlighting their roles in normal skin homeostasis and TME regulation. Moreover, we dis-cuss the influence of MAFs and their secretory profiles on TME remodelling, melanoma progres-sion, targeted therapy resistance and immunosurveillance, highlighting the cellular interactions, the signalling pathways and molecules involved in these processes
Extending the temporal context of ethnobotanical databases: the case study of the Campania region (southern Italy)
<p>Abstract</p> <p>Background</p> <p>Ethnobotanical studies generally describe the traditional knowledge of a territory according to a "hic et nunc" principle. The need of approaching this field also embedding historical data has been frequently acknowledged. With their long history of civilization some regions of the Mediterranean basin seem to be particularly suited for an historical approach to be adopted. Campania, a region of southern Italy, has been selected for a database implementation containing present and past information on plant uses.</p> <p>Methods</p> <p>A relational database has been built on the basis of information gathered from different historical sources, including diaries, travel accounts, and treatises on medicinal plants, written by explorers, botanists, physicians, who travelled in Campania during the last three centuries. Moreover, ethnobotanical uses described in historical herbal collections and in Ancient and Medieval texts from the Mediterranean Region have been included in the database.</p> <p>Results</p> <p>1672 different uses, ranging from medicinal, to alimentary, ceremonial, veterinary, have been recorded for 474 species listed in the data base. Information is not uniformly spread over the Campanian territory; Sannio being the most studied geographical area and Cilento the least one. About 50 plants have been continuously used in the last three centuries in the cure of the same affections. A comparison with the uses reported for the same species in Ancient treatises shows that the origin of present ethnomedicine from old learned medical doctrines needs a case-by-case confirmation.</p> <p>Conclusion</p> <p>The database is flexible enough to represent a useful tool for researchers who need to store and compare present and previous ethnobotanical uses from Mediterranean Countries.</p
Underground experimental study finds no evidence of low-energy resonance in the 6Li(p,Îł)7Be reaction
The astrophysical Li6(p,\u3b3)Be7 reaction occurs during Big Bang nucleosynthesis and the pre-main sequence and main sequence phases of stellar evolution. The low-energy trend of its cross section remains uncertain, since different measurements have provided conflicting results. A recent experiment reported a resonancelike structure at center-of-mass energy 195 keV, associated to a positive-parity state of Be7. The existence of such resonance is still a matter of debate. We report a new measurement of the Li6(p,\u3b3)Be7 cross section performed at the Laboratory for Underground Nuclear Astrophysics, covering the center-of-mass energy range E=60-350 keV. Our results rule out the existence of low-energy resonances. The astrophysical S-factor varies smoothly with energy, in agreement with theoretical models
Characterization of the LUNA neutron detector array for the measurement of the 13C(α,n)16O reaction
We introduce the LUNA neutron detector array developed for the investigation of the 13C(\u3b1, n)16O reaction towards its astrophysical s-process Gamow peak in the low-background environment of the Laboratori Nazionali del Gran Sasso (LNGS). Eighteen 3He counters are arranged in two different configurations (in a vertical and a horizontal orientation) to optimize neutron detection efficiency, target handling and target cooling over the investigated energy range E\u3b1,lab=300 12400 keV (En=2.2 122.6MeV in emitted neutron energy). As a result of the deep underground location, the passive shielding of the setup and active background suppression using pulse shape discrimination, we reached a total background rate of 1.23\ub10.12 counts/hour. This resulted in an improvement of two orders of magnitude over the state of the art allowing a direct measurement of the 13C(\u3b1, n)16O cross-section down to E\u3b1,lab=300 keV. The absolute neutron detection efficiency of the setup was determined using the 51V(p,n)51Cr reaction and an AmBe radioactive source, and completed with a Geant4 simulation. We determined a (34 \ub1 3)% and (38 \ub1 3)% detection efficiency for the vertical and horizontal configurations, respectively, for En=2.4MeV neutrons
Storage, Accumulation and Deceleration of Secondary Beams for Nuclear Astrophysics
Low-energy investigations on rare ion beams are often limited by the
available intensity and purity of the ion species in focus. Here, we present
the first application of a technique that combines in-flight production at
relativistic energies with subsequent secondary beam storage, accumulation and
finally deceleration to the energy of interest. Using the FRS and ESR
facilities at GSI, this scheme was pioneered to provide a secondary beam of
Te for the measurement of nuclear proton-capture at energies of
6 and 7 MeV/u. The technique provided stored beam intensities of about
ions at high purity and brilliance, representing a major step towards
low-energy nuclear physics studies using rare ion beams
Low-energy resonances in the 18O (p,΄) 19F reaction
Background: Shell hydrogen burning during the asymptotic giant branch (AGB) phase through the oxygen
isotopes has been indicated as a key process that is needed to understand the observed 18O/16O relative abundance
in presolar grains and in stellar atmospheres. This ratio is strongly influenced by the relative strengths of the
reactions 18O(p,\u3b1) 15N and 18O(p,\u3b3 ) 19F in low-mass AGB stars. While the former channel has been the focus
of a large number of measurements, the (p,\u3b3 ) reaction path has only recently received some attention and its
stellar reaction rate over a wide temperature range rests on only one measurement.
Purpose: Our aim is the direct measurement of states in 19F as populated through the reaction 18O(p,\u3b3 ) 19F
to better determine their influence on the astrophysical reaction rate, and more generally to improve the
understanding of the nuclear structure of 19F.
Method: Branchings and resonance strengths were measured in the proton energy range Elab
p = 150\u2013400 keV,
using a high-purity germanium detector inside a massive lead shield. The measurement took place in the ultralow-
background environment of the Laboratory for Underground Nuclear Astrophysics (LUNA) experiment at
the Gran Sasso National Laboratory, leading to a highly increased sensitivity.
Results: The uncertainty of the \u3b3 branchings and strengths was improved for all four resonances in the studied
energy range; many new transitions were observed in the case of the 334 keV resonance, and individual \u3b3 decays
of the 215 keV resonance were measured for the first time. In addition a number of transitions to intermediate
states that decay through \u3b1 emission were identified. The strengths of the observed resonances are generally in
agreement with literature values.
Conclusions: Our measurements substantially confirm previous determinations of the relevant resonance
strengths. Therefore the 18O(p,\u3b3 ) 19F reaction rate does not change with respect to the reaction rate reported
in the compilations commonly adopted in the extant computations of red-giant branch and AGB stellar models.
Nevertheless, our measurements definitely exclude a nonstandard scenario for the fluorine nucleosynthesis and
a nuclear physics solution for the 18O depletion observed in Group 2 oxygen-rich stardust grains
Horizons: nuclear astrophysics in the 2020s and beyond
Nuclear astrophysics is a field at the intersection of nuclear physics and astrophysics, which seeks to understand the nuclear engines of astronomical objects and the origin of the chemical elements. This white paper summarizes progress and status of the field, the new open questions that have emerged, and the tremendous scientific opportunities that have opened up with major advances in capabilities across an ever growing number of disciplines and subfields that need to be integrated. We take a holistic view of the field discussing the unique challenges and opportunities in nuclear astrophysics in regards to science, diversity, education, and the interdisciplinarity and breadth of the field. Clearly nuclear astrophysics is a dynamic field with a bright future that is entering a new era of discovery opportunities
Horizons: nuclear astrophysics in the 2020s and beyond
Nuclear astrophysics is a field at the intersection of nuclear physics and astrophysics, which seeks to understand the nuclear engines of astronomical objects and the origin of the chemical elements. This white paper summarizes progress and status of the field, the new open questions that have emerged, and the tremendous scientific opportunities that have opened up with major advances in capabilities across an ever growing number of disciplines and subfields that need to be integrated. We take a holistic view of the field discussing the unique challenges and opportunities in nuclear astrophysics in regards to science, diversity, education, and the interdisciplinarity and breadth of the field. Clearly nuclear astrophysics is a dynamic field with a bright future that is entering a new era of discovery opportunities
Horizons: Nuclear Astrophysics in the 2020s and Beyond
Nuclear Astrophysics is a field at the intersection of nuclear physics and
astrophysics, which seeks to understand the nuclear engines of astronomical
objects and the origin of the chemical elements. This white paper summarizes
progress and status of the field, the new open questions that have emerged, and
the tremendous scientific opportunities that have opened up with major advances
in capabilities across an ever growing number of disciplines and subfields that
need to be integrated. We take a holistic view of the field discussing the
unique challenges and opportunities in nuclear astrophysics in regards to
science, diversity, education, and the interdisciplinarity and breadth of the
field. Clearly nuclear astrophysics is a dynamic field with a bright future
that is entering a new era of discovery opportunities.Comment: 96 pages. Submitted to Journal of Physics
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