721 research outputs found
Dental pulp pluripotent-like stem cells (DPPSC), a new stem cell population with chromosomal stability and osteogenic capacity for biomaterials evaluation
Background: Biomaterials are widely used to regenerate or substitute bone tissue. In order to evaluate their potential use for clinical applications, these need to be tested and evaluated in vitro with cell culture models. Frequently, immortalized osteoblastic cell lines are used in these studies. However, their uncontrolled proliferation rate, phenotypic changes or aberrations in mitotic processes limits their use in long-term investigations. Recently, we described a new pluripotent-like subpopulation of dental pulp stem cells derived from the third molars (DPPSC) that shows genetic stability and shares some pluripotent characteristics with embryonic stem cells. In this study we aim to describe the use of DPPSC to test biomaterials, since we believe that the biomaterial cues will be more critical in order to enhance the differentiation of pluripotent stem cells. Methods: The capacity of DPPSC to differentiate into osteogenic lineage was compared with human sarcoma osteogenic cell line (SAOS-2). Collagen and titanium were used to assess the cell behavior in commonly used biomaterials. The analyses were performed by flow cytometry, alkaline phosphatase and mineralization stains, RT-PCR, immunohistochemistry, scanning electron microscopy, Western blot and enzymatic activity. Moreover, the genetic stability was evaluated and compared before and after differentiation by short-comparative genomic hybridization (sCGH). Results: DPPSC showed excellent differentiation into osteogenic lineages expressing bone-related markers similar to SAOS-2. When cells were cultured on biomaterials, DPPSC showed higher initial adhesion levels. Nevertheless, their osteogenic differentiation showed similar trend among both cell types. Interestingly, only DPPSC maintained a normal chromosomal dosage before and after differentiation on 2D monolayer and on biomaterials. Conclusions: Taken together, these results promote the use of DPPSC as a new pluripotent-like cell model to evaluate the biocompatibility and the differentiation capacity of biomaterials used in bone regeneration
Delta excitation in K^+-nucleus collisions
We present calculations for \Delta excitation in the (K^+,K^+) reaction in
nuclei. The background from quasielastic K^+ scattering in the \Delta region is
also evaluated and shown to be quite small in some kinematical regions, so as
to allow for a clean identification of the \Delta excitation strength. Nuclear
effects tied to the \Delta renormalization in the nucleus are considered and
the reaction is shown to provide new elements to enrich our knowledge of the
\Delta properties in a nuclear medium.Comment: 11 pages, 6 figures, LaTe
Self energies of the pion and the delta isobar from the ^3He(e,e'pi^+)^3H reaction
In a kinematically complete experiment at the Mainz microtron MAMI, pion
angular distributions of the He(e,e'H reaction have been measured
in the excitation region of the resonance to determine the
longitudinal (), transverse (), and the interference part of the
differential cross section. The data are described only after introducing
self-energy modifications of the pion and -isobar propagators. Using
Chiral Perturbation Theory (ChPT) to extrapolate the pion self energy as
inferred from the measurement on the mass shell, we deduce a reduction of the
mass of MeV/c in the
neutron-rich nuclear medium at a density of fm. Our data are consistent with the self energy
determined from measurements of photoproduction from He and heavier
nuclei.Comment: Elsart, 12 pages and 4 figures, Correspondent: Professor Dr. Dr. h.c.
mult. Achim Richter, [email protected], submitted to Phys. Rev.
Let
Theoretical study of lepton events in the atmospheric neutrino experiments at SuperK
Super-Kamiokande has reported the results for the lepton events in the
atmospheric neutrino experiment. These results have been presented for a 22.5kT
water fiducial mass on an exposure of 1489 days, and the events are divided
into sub-GeV, multi-GeV and PC events. We present a study of nuclear medium
effects in the sub-GeV energy region of atmospheric neutrino events for the
quasielastic scattering, incoherent and coherent pion production processes, as
they give the most dominant contribution to the lepton events in this energy
region. We have used the atmospheric neutrino flux given by Honda et al. These
calculations have been done in the local density approximation. We take into
account the effect of Pauli blocking, Fermi motion, Coulomb effect,
renormalization of weak transition strengths in the nuclear medium in the case
of the quasielastic reactions. The inelastic reactions leading to production of
leptons along with pions is calculated in a - dominance model by
taking into account the renormalization of properties in the nuclear
medium and the final state interaction effects of the outgoing pions with the
residual nucleus. We present the results for the lepton events obtained in our
model with and without nuclear medium effects, and compare them with the Monte
Carlo predictions used in the simulation and the experimentally observed events
reported by the Super-Kamiokande collaboration.Comment: 23 pages, 13 figure
Modelling of the effect of ELMs on fuel retention at the bulk W divertor of JET
Effect of ELMs on fuel retention at the bulk W target of JET ITER-Like Wall was studied with multi-scale calculations. Plasma input parameters were taken from ELMy H-mode plasma experiment. The energetic intra-ELM fuel particles get implanted and create near-surface defects up to depths of few tens of nm, which act as the main fuel trapping sites during ELMs. Clustering of implantation-induced vacancies were found to take place. The incoming flux of inter-ELM plasma particles increases the different filling levels of trapped fuel in defects. The temperature increase of the W target during the pulse increases the fuel detrapping rate. The inter-ELM fuel particle flux refills the partially emptied trapping sites and fills new sites. This leads to a competing effect on the retention and release rates of the implanted particles. At high temperatures the main retention appeared in larger vacancy clusters due to increased clustering rate
Why Are Outcomes Different for Registry Patients Enrolled Prospectively and Retrospectively? Insights from the Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF).
Background: Retrospective and prospective observational studies are designed to reflect real-world evidence on clinical practice, but can yield conflicting results. The GARFIELD-AF Registry includes both methods of enrolment and allows analysis of differences in patient characteristics and outcomes that may result. Methods and Results: Patients with atrial fibrillation (AF) and ≥1 risk factor for stroke at diagnosis of AF were recruited either retrospectively (n = 5069) or prospectively (n = 5501) from 19 countries and then followed prospectively. The retrospectively enrolled cohort comprised patients with established AF (for a least 6, and up to 24 months before enrolment), who were identified retrospectively (and baseline and partial follow-up data were collected from the emedical records) and then followed prospectively between 0-18 months (such that the total time of follow-up was 24 months; data collection Dec-2009 and Oct-2010). In the prospectively enrolled cohort, patients with newly diagnosed AF (≤6 weeks after diagnosis) were recruited between Mar-2010 and Oct-2011 and were followed for 24 months after enrolment. Differences between the cohorts were observed in clinical characteristics, including type of AF, stroke prevention strategies, and event rates. More patients in the retrospectively identified cohort received vitamin K antagonists (62.1% vs. 53.2%) and fewer received non-vitamin K oral anticoagulants (1.8% vs . 4.2%). All-cause mortality rates per 100 person-years during the prospective follow-up (starting the first study visit up to 1 year) were significantly lower in the retrospective than prospectively identified cohort (3.04 [95% CI 2.51 to 3.67] vs . 4.05 [95% CI 3.53 to 4.63]; p = 0.016). Conclusions: Interpretations of data from registries that aim to evaluate the characteristics and outcomes of patients with AF must take account of differences in registry design and the impact of recall bias and survivorship bias that is incurred with retrospective enrolment. Clinical Trial Registration: - URL: http://www.clinicaltrials.gov . Unique identifier for GARFIELD-AF (NCT01090362)
ACE and CXCL10 as predictive biomarkers in the LEA study
Background: LEA Study (GEICAM/2006-11/GBG51), is a randomized clinical trial comparing bevacizumab in combination with endocrine therapy (ET + B) with endocrine therapy (ET) in postmenopausal women with advanced or metastatic HR-positive/HER2-negative breast cancer (BC) with indication of hormonotherapy as first-line treatment. Patients with secondary hypertension had better progression-free survival (PFS) and overall survival (OS). We have evaluated the role of two hypertension-related biomarkers, Angiotensin-Converting Enzyme (ACE) and Small-Inducible Cytokine B10 (CXCL10) as prognostic and/or predictive biomarkers of benefit to bevacizumab in the first line metastatic disease.
Methods: From 380 patients, 266 were included in 33 Spanish sites. Median age was 64 years, 63.5% had measurable disease, 97.4% were metastatic at randomization, 51.5% had visceral disease and 52.6% received previous chemotherapy. PFS was 14.3 months (range 0.8-61.1), OS was 34 months (range 0.8-71.6) and 93 patients had Objective Response (OR). We analyzed 124 plasma samples collected before treatment (52 from ET and 72 from ET + B arms). Circulating levels of ACE and CXCL10 were determined by ELISA. ACE levels of 115ng/ml and 135ng/ml were pre-defined as cutoff values. CXCL10 was explored as a quantitative variable.
Results: PFS was 15.1 months (range 1.4-61.1), OS was 31.1 months (range 2.8-61.1) and 40.3% had OR. OR was significantly different between treatment arms (p < 0.001) but not PFS or OS. Median ACE concentration was 130.9ng/ml (range 35.3-315.4). Low ACE (<135ng/ml) had better PFS in the whole population (p = 0.048) and in the ET + B arm (p = 0.041). ACE cutoff of 115 ng/ml was not able to identify any subgroup with better prognosis. Median CXCL10 concentration was 230.3pg/ml (range 15.1-4129.6). A higher expression of CXCL10 was significantly associated with worse OS in the whole population (p < 0.0001) and each treatment arm (p = 0.002 and p = 0.001 in ET and ET + B, respectively). No association with OR were identified neither for ACE nor for CXCL10.
Conclusions: ACE levels could be considered a prognostic and a bevacizumab predictive biomarker of PFS. CXCL10 could be prognostic of OS. Confirmatory studies are warranted
The MEGARA view of outflows in LINERs
Outflows are believed to be ubiquitous in all AGNs, although their presence
in low luminosity AGNs, in particular, for LINERs, has only started to be
explored. Their properties (geometry, mass and energetics) are still far from
being properly characterised. We use integral field spectroscopic data from the
MEGARA instrument, at GTC, to analyse a small sample of nine LINERs, candidates
of hosting ionised gas outflows. We aim to study the main emission lines in the
optical to identify their properties and physical origin. We obtained data
cubes at the lowest (R6000) and highest (R20000) spectral
resolution of MEGARA. We modelled and subtracted the stellar continuum to
obtain the ionised gas contribution, and then fitted the emission lines to
extract their kinematics (velocity and velocity dispersion). We identified
outflows as a secondary component in the emission lines. The primary component
of the emission lines was typically associated to gas in the galactic disc. For
some objects, there is an enhanced- region co-spatial with the
secondary component. We associated it to turbulent gas produced due to the
interaction with the outflows. We find signatures of outflows in six LINERs,
with mass outflow rates ranging from 0.004 to 0.4 Myr and energy
rates from 10 to 10 erg s. Their mean
electronic density is 600cm, extending to distances of 400 pc at
an (absolute) velocity of 340 km s (on average). They tend to be
compact and unresolved, although for some sources they are extended with a
bubble-like morphology. Our results confirm the existence of outflows in the
best LINER candidates identified using previous long-slit spectroscopic and
imaging data. These outflows do not follow the scaling relations obtained for
more luminous AGNs. For some objects we discuss jets as the main drivers of the
outflowsComment: 31 pages, 15 figures. Accepted for publication in Astronomy &
Astrophysic
Health-related quality of life with palbociclib plus endocrine therapy versus capecitabine in postmenopausal patients with hormone receptor–positive metastatic breast cancer: Patient-reported outcomes in the PEARL study
Background: The PEARL study showed that palbociclib plus endocrine therapy (palbociclib/ET) was not superior to capecitabine in improving progression-free survival in postmenopausal patients with metastatic breast cancer resistant to aromatase inhibitors, but was better tolerated. This analysis compared patient-reported outcomes. Patients and methods: The PEARL quality of life (QoL) population comprised 537 patients, 268 randomised to palbociclib/ET (exemestane or fulvestrant) and 269 to capecitabine. Patients completed the European Organisation for Research and Treatment of Cancer QLQ-C30 and QLQ-BR23 and EQ-5D-3L questionnaires. Changes from the baseline and time to deterioration (TTD) were analysed using linear mixed-effect and stratified Cox regression models, respectively. Results: Questionnaire completion rate was high and similar between treatment arms. Significant differences were observed in the mean change in global health status (GHS)/QoL scores from the baseline to cycle 3 (2.9 for palbociclib/ET vs. -2.1 for capecitabine (95% confidence interval [CI], 1.4–8.6; P = 0.007). The median TTD in GHS/QoL was 8.3 months for palbociclib/ET versus 5.3 months for capecitabine (adjusted hazard ratio, 0.70; 95% CI, 0.55–0.89; P = 0.003). Similar improvements for palbociclib/ET were also seen for other scales as physical, role, cognitive, social functioning, fatigue, nausea/vomiting and appetite loss. No differences were observed between the treatment arms in change from the baseline in any item of the EQ-5D-L3 questionnaire as per the overall index score and visual analogue scale. Conclusion: Patients receiving palbociclib/ET experienced a significant delay in deterioration of GHS/QoL and several functional and symptom scales compared with capecitabine, providing additional evidence that palbociclib/ET is better tolerated. Trial registration number: NCT02028507 (ClinTrials.gov). EudraCT study number: 2013-003170-27. © 2021 The Author(s
Mapping the ionized gas of the metal-poor HII galaxy PHL 293B with MEGARA
Here we report the first spatially resolved spectroscopic study for the
galaxy PHL293B using the high-resolution GTC/MEGARA IFU. PHL293B is a local,
extremely metal-poor, high ionization galaxy. This makes PHL 293B an excellent
analogue for galaxies in the early Universe. The MEGARA aperture (~12.5''x
11.3'') covers the entire PHL 293B main body and its far-reaching ionized gas.
We created and discussed maps of all relevant emission lines, line ratios and
physical-chemical properties of the ionized ISM. The narrow emission gas
appears to be ionized mainly by massive stars according to the observed
diganostic line ratios, regardless of the position across the MEGARA aperture.
We detected low intensity broad emission components and blueshifted absorptions
in the Balmer lines (H,H) which are located in the brightest
zone of the galaxy ISM. A chemically homogeneity, across hundreds of parsecs,
is observed in O/H. We take the oxygen abundance 12+log(O/H)=7.64 0.06
derived from the PHL293B integrated spectrum as the representative metallicity
for the galaxy. Our IFU data reveal for the first time that the nebular
HeII4686 emission from PHL 293B is spatially extended and coincident with the
ionizing stellar cluster, and allow us to compute its absolute HeII ionizing
photon flux. Wolf-Rayet bumps are not detected excluding therefore Wolf-Rayet
stars as the main HeII excitation source. The origin of the nebular HeII4686 is
discussed.Comment: 14 pages, 9 Figures, 3 Tables; Accepted for publication in MNRA
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