106 research outputs found
230 s room-temperature storage time and 1.14 eV hole localization energy in In0.5Ga0.5As quantum dots on a GaAs interlayer in GaP with an AlP barrier
This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in Appl. Phys. Lett. 106, 042102 (2015) and may be found at https://doi.org/10.1063/1.4906994.A GaP n+p-diode containing In0.5Ga0.5As quantum dots (QDs) and an AlP barrier is characterized electrically, together with two reference samples: a simple n+p-diode and an n+p-diode with AlP barrier. Localization energy, capture cross-section, and storage time for holes in the QDs are determined using deep-level transient spectroscopy. The localization energy is 1.14(±0.04) eV, yielding a storage time at room temperature of 230(±60) s, which marks an improvement of 2 orders of magnitude compared to the former record value in QDs. Alternative material systems are proposed for still higher localization energies and longer storage times
Mesoporous silica particles are phagocytosed by microglia and induce a mild inflammatory response in vitro
Aim: Mesoporous silica particles (MSPs) are broadly used drug delivery carriers. In this study, the authors analyzed the responses to MSPs of astrocytes and microglia, the two main cellular players in neuroinflammation. Materials & methods: Primary murine cortical mixed glial cultures were treated with rhodamine B-labeled MSPs. Results: MSPs are avidly internalized by microglial cells and remain inside the cells for at least 14 days. Despite this, MSPs do not affect glial cell viability or morphology, basal metabolic activity or oxidative stress. MSPs also do not affect mRNA levels of key proinflammatory genes; however, in combination with lipopolysaccharide, they significantly increase extracellular IL-1β levels. Conclusion: These results suggest that MSPs could be novel tools for specific drug delivery to microglial cells. Plain language summary Mesoporous silica particles (MSPs) are broadly used drug delivery carriers. In this study, the authors analyzed the responses of two types of brain cells, astrocytes and microglia, to MSPs. Mouse astrocytes and microglia were kept alive in cultures and were treated with MSPs that were labeled with a red fluorescent agent to facilitate visualization under the microscope. MSPs are avidly internalized by microglial cells and remain inside the cells for at least 14 days. Despite this, MSPs do not affect glial cell viability or morphology, basal metabolic activity or oxidative stress. When given alone, MSPs do not affect mRNA levels of key proinflammatory genes. However, MSPs given in combination with lipopolysaccharide, a strong proinflammatory agent, significantly increase extracellular levels of IL-1β, one of the proinflammatory mediators studied. These results suggest that MSPs could be novel tools for specific drug delivery to microglial cells
Purcell-Enhanced Single Photons at Telecom Wavelengths from a Quantum Dot in a Photonic Crystal Cavity
Quantum dots are promising candidates for telecom single photon sources due
to their tunable emission across the different low-loss telecommunications
bands, making them compatible with existing fiber networks. Their suitability
for integration into photonic structures allows for enhanced brightness through
the Purcell effect, supporting efficient quantum communication technologies.
Our work focuses on InAs/InP QDs created via droplet epitaxy MOVPE to operate
within the telecoms C-band. We observe a short radiative lifetime of 340 ps,
arising from a Purcell factor of 5, owing to interaction of the QD within a
low-mode-volume photonic crystal cavity. Through in-situ control of the sample
temperature, we show both temperature tuning of the QD's emission wavelength
and a preserved single photon emission purity at temperatures up to 25K. These
findings suggest the viability of QD-based, cryogen-free, C-band single photon
sources, supporting applicability in quantum communication technologies
Different Plasma Markers of Inflammation Are Influenced by Immune Recovery and cART Composition or Intensification in Treated HIV Infected Individuals
BACKGROUND: HIV-1 infection increases plasma levels of inflammatory markers. Combination antiretroviral therapy (cART) does not restore inflammatory markers to normal levels. Since intensification of cART with raltegravir reduced CD8 T-cell activation in the Discor-Ral and IntegRal studies, we have evaluated the effect of raltegravir intensification on several soluble inflammation markers in these studies. METHODS: Longitudinal plasma samples (0-48 weeks) from the IntegRal (n = 67, 22 control and 45 intensified individuals) and the Discor-Ral studies (44 individuals with CD4 T-cell counts<350 cells/µl, 14 control and 30 intensified) were assayed for 25 markers. Mann-Whitney, Wilcoxon, Spearman test and linear mixed models were used for analysis. RESULTS: At baseline, different inflammatory markers were strongly associated with HCV co-infection, lower CD4 counts and with cART regimens (being higher in PI-treated individuals), but poorly correlated with detection of markers of residual viral replication. Although raltegravir intensification reduced inflammation in individuals with lower CD4 T-cell counts, no effect of intensification was observed on plasma markers of inflammation in a global analysis. An association was found, however, between reductions in immune activation and plasma levels of the coagulation marker D-dimer, which exclusively decreased in intensified patients on protease inhibitor (PI)-based cART regimens (P = 0.040). CONCLUSIONS: The inflammatory profile in treated HIV-infected individuals showed a complex association with HCV co-infection, the levels of CD4 T cells and the cART regimen. Raltegravir intensification specifically reduced D-dimer levels in PI-treated patients, highlighting the link between cART composition and residual viral replication; however, raltegravir had little effect on other inflammatory markers
Epidemiological patterns of asbestos exposure and spatial clusters of incident cases of malignant mesothelioma from the Italian national registry
Abstract
BACKGROUND:
Previous ecological spatial studies of malignant mesothelioma cases, mostly based on mortality data, lack reliable data on individual exposure to asbestos, thus failing to assess the contribution of different occupational and environmental sources in the determination of risk excess in specific areas. This study aims to identify territorial clusters of malignant mesothelioma through a Bayesian spatial analysis and to characterize them by the integrated use of asbestos exposure information retrieved from the Italian national mesothelioma registry (ReNaM).
METHODS:
In the period 1993 to 2008, 15,322 incident cases of all-site malignant mesothelioma were recorded and 11,852 occupational, residential and familial histories were obtained by individual interviews. Observed cases were assigned to the municipality of residence at the time of diagnosis and compared to those expected based on the age-specific rates of the respective geographical area. A spatial cluster analysis was performed for each area applying a Bayesian hierarchical model. Information about modalities and economic sectors of asbestos exposure was analyzed for each cluster.
RESULTS:
Thirty-two clusters of malignant mesothelioma were identified and characterized using the exposure data. Asbestos cement manufacturing industries and shipbuilding and repair facilities represented the main sources of asbestos exposure, but a major contribution to asbestos exposure was also provided by sectors with no direct use of asbestos, such as non-asbestos textile industries, metal engineering and construction. A high proportion of cases with environmental exposure was found in clusters where asbestos cement plants were located or a natural source of asbestos (or asbestos-like) fibers was identifiable. Differences in type and sources of exposure can also explain the varying percentage of cases occurring in women among clusters.
CONCLUSIONS:
Our study demonstrates shared exposure patterns in territorial clusters of malignant mesothelioma due to single or multiple industrial sources, with major implications for public health policies, health surveillance, compensation procedures and site remediation programs
The ICARUS Experiment, A Second-Generation Proton Decay Experiment and Neutrino Observatory at the Gran Sasso Laboratory
The final phase of the ICARUS physics program requires a sensitive mass of liquid Argon of 5000 tons or more. The T600 detector stands today as the first living proof that such large detector can be built and that liquid Argon imaging technology can be implemented on such large scales. After the successful completion of a series of technical tests to be performed at the assembly hall in Pavia, the T600 detector will be ready to be transported into the LNGS tunnel. The operation of the T600 at the LNGS will allow us (1) to develop the local infrastructure needed to operate our large detector (2) to start the handling of the underground liquid argon technology (3) to study the local background (4) to start the data taking with an initial liquid argon mass that will reach in a 5-6 year program the multi-kton goal. The T600 is to be considered as the first milestone on the road towards a total sensitive mass of 5000 tons: it is the first piece of the detector to be complemented by further modules of appropriate size and dimensions, in order to reach in a most efficient and rapid way the final design mass. In this document, we describe the physics program that will be accomplished within the first phase of the program
Observation of long ionizing tracks with the ICARUS T600 first half-module
F. Arneodo, B. Bade"ek, A. Badertscher, B. Baiboussinov, M. Baldo Ceolin, G. Battistoni, B. Bekman, P. Benetti, E. Bernardini, M. Bischofberger, A. Borio di Tigliole, R. Brunetti, A. Bueno, E. Calligarich, M. Campanelli, C. Carpanese, D. Cavalli, F. Cavanna, P. Cennini, S. Centro, A. Cesana, C. Chen, D. Chen, D.B. Chen, Y. Chen, D. Cline, Z. Dai, C. De Vecchi, A. Dabrowska, R. Dolfini*, M. Felcini, A. Ferrari, F. Ferri, Y. Ge, A. Gigli Berzolari, I. Gil-Botella, K. Graczyk, L. Grandi, K. He, J. Holeczek, X. Huang, C. Juszczak, D. Kie"czewska, J. Kisiel, T. Koz"owski, H. Kuna-Ciska", M. Laffranchi, J. Łagoda, Z. Li, F. Lu, J. Ma, M. Markiewicz, A. Martinez de la Ossa, C. Matthey, F. Mauri, D. Mazza, G. Meng, M. Messina, C. Montanari, S. Muraro, S. Navas-Concha, M. Nicoletto, G. Nurzia, S. Otwinowski, Q. Ouyang, O. Palamara, D. Pascoli, L. Periale, G. Piano Mortari, A. Piazzoli, P. Picchi, F. Pietropaolo, W. P ! o"ch"opek, T. Rancati, A. Rappoldi, G.L. Raselli, J. Rico, E. Rondio, M. Rossella, A. Rubbia, C. Rubbia, P. Sala, D. Scannicchio, E. Segreto, F. Sergiampietri, J. Sobczyk, J. Stepaniak, M. Szeptycka, M. Szleper, M. Szarska, M. Terrani, S. Ventura, C. Vignoli, H. Wang, M. W ! ojcik, J. Woo, G. Xu, Z. Xu, A. Zalewska, J. Zalipska, C. Zhang, Q. Zhang, S. Zhen, W. Zipper a INFN Laboratori Nazionali del Gran Sasso, s.s. 17bis Km 18+910, Assergi (L'Aquila), Italy b Institute of Experimental Physics, Warsaw University, Warszawa, Poland c Institute for Particle Physics, ETH H . onggerberg, Z . urich, Switzerland Dipartimento di Fisica e INFN, Universit " a di Padova, via Marzolo 8, Padova, Italy Dipartimento di Fisica e INFN, Universit " a di Milano, via Celoria 16, Milano, Italy f Institute of Physics, University of Silesia, Katowice, Poland Dipartimento di Fisica e INFN, Universit " a di Pavia, via Bassi 6, Pavia, Italy Dpto de F!isica Te ! orica y del Cosmos & C.A.F.P.E., Universidad de Granada, Avda. Severo Ochoa s/n, Granada, Spain Dipartimento di Fisica e INFN, Universit " a dell'Aquila, via Vetoio, L'Aquila, Italy CERN, CH-1211 Geneva 23, Switzerland Politecnico di Milano (CESNEF), Universit " a di Milano, via Ponzio 34/3, Milano, Ital
Strategies to reengage patients lost to follow up in HIV care in high income countries, a scoping review
Background: Despite remarkable achievements in antiretroviral therapy (ART), losses to follow-up (LTFU) might prevent the long-term success of HIV treatment and might delay the achievement of the 90-90-90 objectives. This scoping review is aimed at the description and analysis of the strategies used in high-income countries to reengage LTFU in HIV care, their implementation and impact. Methods: A scoping review was done following Arksey & O'Malley's methodological framework and recommendations from Joanna Briggs Institute. Peer reviewed articles were searched for in Pubmed, Scopus and Web of Science; and grey literature was searched for in Google and other sources of information. Documents were charted according to the information presented on LTFU, the reengagement procedures used in HIV units in high-income countries, published during the last 15 years. In addition, bibliographies of chosen articles were reviewed for additional articles. Results: Twenty-eight documents were finally included, over 80% of them published in the United States later than 2015. Database searches, phone calls and/or mail contacts were the most common strategies used to locate and track LTFU, while motivational interviews and strengths-based techniques were used most often during reengagement visits. Outcomes like tracing activities efficacy, rates of reengagement and viral load reduction were reported as outcome measures. Conclusions: This review shows a recent and growing trend in developing and implementing patient reengagement strategies in HIV care. However, most of these strategies have been implemented in the United States and little information is available for other high-income countries. The procedures used to trace and contact LTFU are similar across reviewed studies, but their impact and sustainability are widely different depending on the country studied
Genome-wide analyses identify a role for SLC17A4 and AADAT in thyroid hormone regulation.
Thyroid dysfunction is an important public health problem, which affects 10% of the general population and increases the risk of cardiovascular morbidity and mortality. Many aspects of thyroid hormone regulation have only partly been elucidated, including its transport, metabolism, and genetic determinants. Here we report a large meta-analysis of genome-wide association studies for thyroid function and dysfunction, testing 8 million genetic variants in up to 72,167 individuals. One-hundred-and-nine independent genetic variants are associated with these traits. A genetic risk score, calculated to assess their combined effects on clinical end points, shows significant associations with increased risk of both overt (Graves' disease) and subclinical thyroid disease, as well as clinical complications. By functional follow-up on selected signals, we identify a novel thyroid hormone transporter (SLC17A4) and a metabolizing enzyme (AADAT). Together, these results provide new knowledge about thyroid hormone physiology and disease, opening new possibilities for therapeutic targets
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