933 research outputs found
Highly efficient planar perovskite solar cells through band alignment engineering
The simplification of perovskite solar cells (PSCs), by replacing the mesoporous electron selective layer (ESL) with a planar one, is advantageous for large-scale manufacturing. PSCs with a planar TiO2 ESL have been demonstrated, but these exhibit unstabilized power conversion efficiencies (PCEs). Herein we show that planar PSCs using TiO2 are inherently limited due to conduction band misalignment and demonstrate, with a variety of characterization techniques, for the first time that SnO2 achieves a barrier-free energetic configuration, obtaining almost hysteresis-free PCEs of over 18% with record high voltages of up to 1.19 V
Mechanical behavior of non veneered three unit fixed partial dentures of alumina-zirconia Under cyclic load in wet environment
A 6 day course of liposomal amphotericin B in the treatment of infantile visceral leishmaniasis: the Italian experience
OBJECTIVES: To evaluate in a retrospective analysis the efficacy and safety of a 6 day course of liposomal amphotericin B (L-AmB) in infantile cases of Mediterranean visceral leishmaniasis (VL) diagnosed over a 10 year period in Italy.
PATIENTS AND METHODS: Patients included were diagnosed as having VL consecutively admitted from December 1992 to December 2001 at four main referral children's hospitals in Italy and treated with six intravenous doses of 3 mg/kg L-AmB given on days 1-5 and 10 (a total dose of 18 mg/kg). Demographic data, nutritional status, underlying diseases, clinical and laboratory findings, and therapy outcome were considered.
RESULTS: A total of 164 HIV-negative children (median age 1.6 years; range 4 months to 14 years) were enrolled. All patients were initially cured by the given treatment, and did not present adverse events related to drug infusion. Seven patients (4.3%) had a clinical and parasitological relapse 3-15 months after therapy. All relapses were successfully retreated with 3 mg/kg L-AmB for 10 consecutive days (a total dose of 30 mg/kg).
CONCLUSIONS: This study highlights the efficacy (>95%) and safety of the six dose L-AmB regimen and validates it as a first-line treatment for Mediterranean VL in children
Cost-Effectiveness of Haemorrhoidal Artery Ligation versus Rubber Band Ligation for the Treatment of Grade II–III Haemorrhoids: Analysis Using Evidence from the HubBLe Trial
Aim Haemorrhoids are a common condition, with nearly
30,000 procedures carried out in England in 2014/15, and
result in a significant quality-of-life burden to patients and
a financial burden to the healthcare system. This study
examined the cost effectiveness of haemorrhoidal artery
ligation (HAL) compared with rubber band ligation (RBL)
in the treatment of grade II–III haemorrhoids.
Method This analyses used data from the HubBLe study, a
multicentre, open-label, parallel group, randomised controlled
trial conducted in 17 acute UK hospitals between
September 2012 and August 2015. A full economic evaluation,
including long-term cost effectiveness, was conducted
from the UK National Health Service (NHS)
perspective. Main outcomes included healthcare costs,
quality-adjusted life-years (QALYs) and recurrence. Costeffectiveness
results were presented in terms of incremental
cost per QALY gained and cost per recurrence
avoided. Extrapolation analysis for 3 years beyond the trial
follow-up, two subgroup analyses (by grade of haemorrhoids
and recurrence following RBL at baseline), and
various sensitivity analyses were undertaken.
Results In the primary base-case within-trial analysis, the
incremental total mean cost per patient for HAL compared
with RBL was £1027 (95% confidence interval [CI] £782–
£1272, p\0.001). The incremental QALYs were 0.01
QALYs (95% CI -0.02 to 0.04, p = 0.49). This generated
an incremental cost-effectiveness ratio (ICER) of £104,427
per QALY. In the extrapolation analysis, the estimated
probabilistic ICER was £21,798 per QALY. Results from
all subgroup and sensitivity analyses did not materially
change the base-case result.
Conclusions Under all assessed scenarios, the HAL procedure
was not cost effective compared with RBL for the
treatment of grade II-III haemorrhoids at a cost-effectiveness
threshold of £20,000 per QALY; therefore
Cosmic rays and molecular clouds
This paper deals with the cosmic-ray penetration into molecular clouds and
with the related gamma--ray emission. High energy cosmic rays interact with the
dense gas and produce neutral pions which in turn decay into two gamma rays.
This makes molecular clouds potential sources of gamma rays, especially if they
are located in the vicinity of a powerful accelerator that injects cosmic rays
in the interstellar medium. The amplitude and duration in time of the
cosmic--ray overdensity around a given source depend on how quickly cosmic rays
diffuse in the turbulent galactic magnetic field. For these reasons, gamma-ray
observations of molecular clouds can be used both to locate the sources of
cosmic rays and to constrain the properties of cosmic-ray diffusion in the
Galaxy.Comment: To appear in the proceedings of the San Cugat Forum on Astrophysics
2012, 27 pages, 10 figure
Supersymmetric Monojets at the Large Hadron Collider
Supersymmetric monojets may be produced at the Large Hadron Collider by the
process qg -> squark neutralino_1 -> q neutralino_1 neutralino_1, leading to a
jet recoiling against missing transverse momentum. We discuss the feasibility
and utility of the supersymmetric monojet signal. In particular, we examine the
possible precision with which one can ascertain the neutralino_1-squark-quark
coupling via the rate for monojet events. Such a coupling contains information
on the composition of the neutralino_1 and helps bound dark matter direct
detection cross-sections and the dark matter relic density of the neutralino_1.
It also provides a check of the supersymmetric relation between gauge couplings
and gaugino-quark-squark couplings.Comment: 46 pages, 10 figures. The appendix has been rewritten to correct an
error that appears in all previous versions of the appendix. This error has
no effect on the results in the main body of the pape
Radio emission from Supernova Remnants
The explosion of a supernova releases almost instantaneously about 10^51 ergs
of mechanic energy, changing irreversibly the physical and chemical properties
of large regions in the galaxies. The stellar ejecta, the nebula resulting from
the powerful shock waves, and sometimes a compact stellar remnant, constitute a
supernova remnant (SNR). They can radiate their energy across the whole
electromagnetic spectrum, but the great majority are radio sources. Almost 70
years after the first detection of radio emission coming from a SNR, great
progress has been achieved in the comprehension of their physical
characteristics and evolution. We review the present knowledge of different
aspects of radio remnants, focusing on sources of the Milky Way and the
Magellanic Clouds, where the SNRs can be spatially resolved. We present a brief
overview of theoretical background, analyze morphology and polarization
properties, and review and critical discuss different methods applied to
determine the radio spectrum and distances. The consequences of the interaction
between the SNR shocks and the surrounding medium are examined, including the
question of whether SNRs can trigger the formation of new stars. Cases of
multispectral comparison are presented. A section is devoted to reviewing
recent results of radio SNRs in the Magellanic Clouds, with particular emphasis
on the radio properties of SN 1987A, an ideal laboratory to investigate
dynamical evolution of an SNR in near real time. The review concludes with a
summary of issues on radio SNRs that deserve further study, and analyzing the
prospects for future research with the latest generation radio telescopes.Comment: Revised version. 48 pages, 15 figure
Double hadron leptoproduction in the nuclear medium
First measurement of double-hadron production in deep-inelastic scattering
has been measured with the HERMES spectrometer at HERA using a 27.6 GeV
positron beam with deuterium, nitrogen, krypton and xenon targets. The
influence of the nuclear medium on the ratio of double-hadron to single-hadron
yields has been investigated. Nuclear effects are clearly observed but with
substantially smaller magnitude and reduced -dependence compared to
previously measured single-hadron multiplicity ratios. The data are in fair
agreement with models based on partonic or pre-hadronic energy loss, while they
seem to rule out a pure absorptive treatment of the final state interactions.
Thus, the double-hadron ratio provides an additional tool for studying
modifications of hadronization in nuclear matter
In Vitro Identification and Characterization of CD133pos Cancer Stem-Like Cells in Anaplastic Thyroid Carcinoma Cell Lines
Background: Recent publications suggest that neoplastic initiation and growth are dependent on a small subset of cells,
termed cancer stem cells (CSCs). Anaplastic Thyroid Carcinoma (ATC) is a very aggressive solid tumor with poor prognosis,
characterized by high dedifferentiation. The existence of CSCs might account for the heterogeneity of ATC lesions. CD133
has been identified as a stem cell marker for normal and cancerous tissues, although its biological function remains
unknown.
Methodology/Principal Findings: ATC cell lines ARO, KAT-4, KAT-18 and FRO were analyzed for CD133 expression. Flow
cytometry showed CD133pos cells only in ARO and KAT-4 (6469% and 57612%, respectively). These data were confirmed by
qRT-PCR and immunocytochemistry. ARO and KAT-4 were also positive for fetal marker oncofetal fibronectin and negative
for thyrocyte-specific differentiating markers thyroglobulin, thyroperoxidase and sodium/iodide symporter. Sorted ARO/
CD133pos cells exhibited higher proliferation, self-renewal, colony-forming ability in comparison with ARO/CD133neg.
Furthermore, ARO/CD133pos showed levels of thyroid transcription factor TTF-1 similar to the fetal thyroid cell line TAD-2,
while the expression in ARO/CD133neg was negligible. The expression of the stem cell marker OCT-4 detected by RT-PCR
and flow cytometry was markedly higher in ARO/CD133pos in comparison to ARO/CD133neg cells. The stem cell markers c-
KIT and THY-1 were negative. Sensitivity to chemotherapy agents was investigated, showing remarkable resistance to
chemotherapy-induced apoptosis in ARO/CD133pos when compared with ARO/CD133neg cells.
Conclusions/Significance: We describe CD133pos cells in ATC cell lines. ARO/CD133pos cells exhibit stem cell-like features -
such as high proliferation, self-renewal ability, expression of OCT-4 - and are characterized by higher resistance to
chemotherapy. The simultaneous positivity for thyroid specific factor TTF-1 and onfFN suggest they might represent
putative thyroid cancer stem-like cells. Our in vitro findings might provide new insights for novel therapeutic approaches
Combinatorial targeting and discovery of ligand-receptors in organelles of mammalian cells
Phage display screening allows the study of functional protein–protein interactions at the cell surface, but investigating intracellular organelles remains a challenge. Here we introduce internalizing-phage libraries to identify clones that enter mammalian cells through a receptor-independent mechanism and target-specific organelles as a tool to select ligand peptides and identify their intracellular receptors. We demonstrate that penetratin, an antennapedia-derived peptide, can be displayed on the phage envelope and mediate receptor-independent uptake of internalizing phage into cells. We also show that an internalizing-phage construct displaying an established mitochondria-specific localization signal targets mitochondria, and that an internalizing-phage random peptide library selects for peptide motifs that localize to different intracellular compartments. As a proof-of-concept, we demonstrate that one such peptide, if chemically fused to penetratin, is internalized receptor-independently, localizes to mitochondria, and promotes cell death. This combinatorial platform technology has potential applications in cell biology and drug development
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