6,557 research outputs found
Search for the standard model Higgs boson decaying into tau pairs produced in association with a W or Z boson
A search of the Standard Model (SM) Higgs boson production in association with a vector boson, W or Z, is performed at LHC, using data collected with the CMS detector during 2011 and 2012, corresponding to a total integrated luminosity of 24.5 fbâ1. The associated production represents an interesting channel for the low-mass Higgs boson search, thanks to the presence of highly energetic leptons coming from W and Z decays which suppress the most relevant SM backgrounds. The Higgs decay search is performed in the di-Ï decay mode, in which each Ï can decay into an electron, a muon or hadronically (Ïh) and a neutrino. The
WH channel has three leptons in the final state, with W decaying into electron or muon and a neutrino; instead the ZH channel is performed in a four leptons final state, where the Z decays into a pair of electrons or muons. The data analysed are compatible with the SM expected background, and no significant excess is observed
The surface accessibility of α-bungarotoxin monitored by a novel paramagnetic probe
The surface accessibility of {alpha}-bungarotoxin has been investigated by using Gd2L7, a newly designed paramagnetic NMR probe. Signal attenuations induced by Gd2L7 on {alpha}-bungarotoxin C{alpha}H peaks of 1H-13C HSQC spectra have been analyzed and compared with the ones previously obtained in the presence of GdDTPA-BMA. In spite of the different molecular size and shape, for the two probes a common pathway of approach to the {alpha}-bungarotoxin surface can be observed with an equally enhanced access of both GdDTPA-BMA and Gd2L7 towards the protein surface side where the binding site is located. Molecular dynamics simulations suggest that protein backbone flexibility and surface hydration contribute to the observed preferential approach of both gadolinium complexes specifically to the part of the {alpha}-bungarotoxin surface which is involved in the interaction with its physiological target, the nicotinic acetylcholine receptor
Alternate bar response to sediment supply termination
Sediment supply is widely held to be one of the primary controls on bar topography in alluvial channels, yet quantitative linkages between sediment supply and bar topography are not well developed. We explore the conditions under which alternate bars form and how they respond to the elimination of sediment supply in two linked laboratory experiments. The first set of experiments was conducted in a 28 m long, 0.86 m wide flume channel using a unimodal sandâgravel mix. The second set of experiments was conducted at field scale in a 55 m long, 2.74 m wide channel using a unimodal gravel mixture. In both experiments, alternate bars and patchy surface grainâsize distributions developed under steady flow and sediment supply conditions. The cessation of the sediment supply induced a reduction in the surface grainâsize heterogeneity and the bars were eliminated. In both flumes, mean boundary shear stress had declined, but were capable of moving sediments after the bars disappeared, albeit at relatively small rates compared to when the bars were present. In the smaller flume, the previously stationary bars migrated out of the flume and were not replaced with new bars. A nearly featureless bed formed with limited surface grainâsize heterogeneity, a slightly coarsened surface and a slightly reduced slope. In the larger flume, the formation of alternate bars was induced by an imposed upstream flow constriction and as such, the bars did not migrate. Termination of sediment supply led to progressive erosion of bed topography and loss of the bars, coarsening of the bed surface, loss of bed texture patchiness and significant slope reduction. The original alternate bar topography redeveloped when the sediment supply was restored once sufficient deposition had occurred to reconstruct the original channel slope. This shows that the bar loss was reversible by establishing the previous conditions and highlights the importance of sediment supply for bar formation. The role of sediment supply in bar formation and stability is not often recognized in stream restoration. Our results suggest that the loss of sediment supply can significantly affect alternate bar topography and that considerable volumes of sediment may be needed restore channel bars
Persistent systemic microbial translocation, inflammation, and intestinal damage during Clostridioides difficile infection
Background. Clostridioides difficile infection (CDI) might be complicated by the development of nosocomial bloodstream infection (n-BSI). Based on the hypothesis that alteration of the normal gut integrity is present during CDI, we evaluated markers of microbial translocation, inflammation, and intestinal damage in patients with CDI. Methods. Patients with documented CDI were enrolled in the study. For each subject, plasma samples were collected at T0 and T1 (before and after CDI therapy, respectively), and the following markers were evaluated: lipopolysaccharide-binding protein (LPB), EndoCab IgM, interleukin-6, intestinal fatty acid binding protein (I-FABP). Samples from nonhospitalized healthy controls were also included. The study population was divided into BSI+/BSI- and fecal microbiota transplantation (FMT) +/FMT- groups, according to the development of n-BSI and the receipt of FMT, respectively. Results. Overall, 45 subjects were included; 8 (17.7%) developed primary n-BSI. Markers of microbial translocation and intestinal damage significantly decreased between T0 and T1, however, without reaching values similar to controls (P < .0001). Compared with BSI-, a persistent high level of microbial translocation in the BSI+ group was observed. In the FMT+ group, markers of microbial translocation and inflammation at T1 tended to reach control values. Conclusions. CDI is associated with high levels of microbial translocation, inflammation, and intestinal damage, which are still present at clinical resolution of CDI. The role of residual mucosal perturbation and persistence of intestinal cell damage in the development of n-BSI following CDI, as well as the possible effect of FMT in the restoration of mucosal integrity, should be further investigated
A prototype large-angle photon veto detector for the P326 experiment at CERN
The P326 experiment at the CERN SPS has been proposed with the purpose of
measuring the branching ratio for the decay K^+ \to \pi^+ \nu \bar{\nu} to
within 10%. The photon veto system must provide a rejection factor of 10^8 for
\pi^0 decays. We have explored two designs for the large-angle veto detectors,
one based on scintillating tiles and the other using scintillating fibers. We
have constructed a prototype module based on the fiber solution and evaluated
its performance using low-energy electron beams from the Frascati Beam-Test
Facility. For comparison, we have also tested a tile prototype constructed for
the CKM experiment, as well as lead-glass modules from the OPAL electromagnetic
barrel calorimeter. We present results on the linearity, energy resolution, and
time resolution obtained with the fiber prototype, and compare the detection
efficiency for electrons obtained with all three instruments.Comment: 8 pages, 9 figures, 2 tables. Presented at the 2007 IEEE Nuclear
Science Symposium, Honolulu HI, USA, 28 October - 3 November 200
Immunotherapy as a turning point in the treatment of acute myeloid leukemia
Acute myeloid leukemia (AML) is a malignant disease of hematopoietic precursors at
the earliest stage of maturation, resulting in a clonalproliferation of myoblasts replacing normal
hematopoiesis. AML represents one of the most common types of leukemia, mostly affecting elderly
patients. To date, standard chemotherapy protocols are only effective in patients at low risk of relapse
and therapy-related mortality. The average 5-year overall survival (OS) is approximately 28%. Allogeneic hematopoietic stem cell transplantation (HSCT) improves prognosis but is limited by donor
availability, a relatively young age of patients, and absence of significant comorbidities. Moreover, it
is associated with significant morbidity and mortality. However, increasing understanding of AML
immunobiology is leading to the development of innovative therapeutic strategies. Immunotherapy
is considered an attractive strategy for controlling and eliminating the disease. It can be a real
breakthrough in the treatment of leukemia, especially in patients who are not eligible forintensive
chemotherapy. In this review, we focused on the progress of immunotherapy in the field of AML by
discussing monoclonal antibodies (mAbs), immune checkpoint inhibitors, chimeric antigen receptor
T cells (CAR-T cells), and vaccine therapeutic choices
On the Response of Particle Detectors in Vaidya Spacetimes
Using the formalism of the interaction picture we calculate an expression for
the Wightman function for only the spherically symmetric modes of a quantum
Klein-Gordon scalar field in a general Vaidya spacetime with ingoing null dust.
It is demonstrated that particle detectors following time-like trajectories
that are in the ground state at some time outside of the collapsing shell will
respond independently from the configuration of the ingoing null dust if the
response is taken at any time outside of the collapsing shell. For detectors
that are taken to be in the ground state at a time interior to the shell it is
shown that their response will depend on the configuration of the ingoing null
dust. Relevance to the information loss paradox is discussed.Comment: 14 pages, 2 figure
Gold Nanorods as Radiopharmaceutical Carriers: Preparation and Preliminary Radiobiological In Vitro Tests
Low-energy electrons (Auger electrons) can be produced via the interaction of photons with gold atoms in gold nanorods (AuNRs). These electrons are similar to those emitted during the decay of technetium-99m (99mTc), a radioactive nuclide widely used for diagnostics in nuclear medicine. Auger and internal conversion (IC) electron emitters appropriately targeted to the DNA of tumors cells may, therefore, represent a new radiotherapeutic approach. 99mTc radiopharmaceuticals, which are used for diagnosis, could indeed be used in theragnostic fields when loaded on AuNRs and delivered to a tumor site. This work aims to provide a proof of concept (i) to evaluate AuNRs as carriers of 99mTc-based radiopharmaceuticals, and (ii) to evaluate the efficacy of Auger electrons emitted by photon-irradiated AuNRs in inducing radio-induced damage in T98G cells, thus mimicking the effect of Auger electrons emitted during the decay of 99mTc used in clinical settings. Data are presented on AuNRsâ chemical characterization (with an aspect ratio of 3.2 and Surface Plasmon Resonance bands at 520 and 680 nm) and the loading of pharmaceuticals (after 99mTc decay) on their surface. Spectroscopic characterizations, such as UV-Vis and synchrotron radiation-induced X-ray photoelectron (SR-XPS) spectroscopies, were performed to investigate the drugâAuNR interaction. Finally, preliminary radiobiological data on cell killing with AuNRs are presented
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