329 research outputs found
Organic long persistent luminescence from a thermally activated delayed fluorescence compound
Funding: UK EPSRC (grants EP/ P010482/1, EP/J01771X, EP/J00916, and EP/R035164/1). We gratefully acknowledge funding through the EPSRC NSFCBET lead agency agreement (EP/R010595/1,1706207) and a Leverhulme Trust Research Grant (RPG-2017-231).Organic long‐persistent luminescence (OLPL) is one of the most promising methods for long‐lived‐emission applications. However, present room‐temperature OLPL emitters are mainly based on a bimolecular exciplex system which usually needs an expensive small molecule such as 2,8‐bis(diphenyl‐phosphoryl)dibenzo[b,d]thiophene (PPT) as the acceptor. In this study, a new thermally activated delayed fluorescence (TADF) compound, 3‐(4‐(9H‐carbazol‐9‐yl)phenyl)acenaphtho[1,2‐b]pyrazine‐8,9‐dicarbonitrile (CzPhAP), is designed, which also shows OLPL in many well‐known hosts such as PPT, 2,2′,2″‐(1,3,5‐benzinetriyl)‐tris(1‐phenyl‐1‐H‐benzimidazole) (TPBi), and poly(methyl methacrylate) (PMMA), without any exciplex formation, and its OLPL duration reaches more than 1 h at room temperature. Combining the low cost of PMMA manufacture and flexible designs of TADF molecules, pure organic, large‐scale, color tunable, and low‐cost room‐temperature OLPL applications become possible. Moreover, it is found that the onset of the 77 K afterglow spectra from a TADF‐emitter‐doped film is not necessarily reliable for determining the lowest triplet state energy level. This is because in some TADF‐emitter‐doped films, optical excitation can generate charges (electron and holes) that can later recombine to form singlet excitons during the phosphorescence spectrum measurement. The spectrum taken in the phosphorescence time window at low temperature may consequently consist of both singlet and triplet emission.Publisher PDFPeer reviewe
Recommendations for The Conduct of Economic Evaluations in Osteoporosis: Outcomes of An Experts’ Consensus Meeting Organized by The European Society for Clinical and Economic Aspects of Osteoporosis, Osteoarthritis and Musculoskeletal Diseases (ESCEO) And the US Branch of The International Osteoporosis Foundation
Summary
Economic evaluations are increasingly used to assess the value of health interventions, but variable quality and heterogeneity limit the use of these evaluations by decision-makers. These recommendations provide guidance for the design, conduct, and reporting of economic evaluations in osteoporosis to improve their transparency, comparability, and methodologic standards. Introduction
This paper aims to provide recommendations for the conduct of economic evaluations in osteoporosis in order to improve their transparency, comparability, and methodologic standards. Methods
A working group was convened by the European Society for Clinical and Economic Aspects of Osteoporosis and Osteoarthritis to make recommendations for the design, conduct, and reporting of economic evaluations in osteoporosis, to define an osteoporosis-specific reference case to serve a minimum standard for all economic analyses in osteoporosis, to discuss methodologic challenges and initiate a call for research. A literature review, a face-to-face meeting in New York City (including 11 experts), and a review/approval by a larger group of experts worldwide (including 23 experts in total) were conducted. Results
Recommendations on the type of economic evaluation, methods for economic evaluation, modeling aspects, base-case analysis and population, excess mortality, fracture costs and disutility, treatment characteristics, and model validation were provided. Recommendations for reporting economic evaluations in osteoporosis were also made and an osteoporosis-specific checklist was designed that includes items to report when performing an economic evaluation in osteoporosis. Further, 12 minimum criteria for economic evaluations in osteoporosis were identified and 12 methodologic challenges and need for further research were discussed. Conclusion
While the working group acknowledges challenges and the need for further research, these recommendations are intended to supplement general and national guidelines for economic evaluations, improve transparency, quality, and comparability of economic evaluations in osteoporosis, and maintain methodologic standards to increase their use by decision-makers
Influence of apical oxygen on the extent of in-plane exchange interaction in cuprate superconductors
In high Tc superconductors the magnetic and electronic properties are
determined by the probability that valence electrons virtually jump from site
to site in the CuO2 planes, a mechanism opposed by on-site Coulomb repulsion
and favored by hopping integrals. The spatial extent of the latter is related
to transport properties, including superconductivity, and to the dispersion
relation of spin excitations (magnons). Here, for three antiferromagnetic
parent compounds (single-layer Bi2Sr0.99La1.1CuO6+delta, double-layer
Nd1.2Ba1.8Cu3O6 and infinite-layer CaCuO2) differing by the number of apical
atoms, we compare the magnetic spectra measured by resonant inelastic x-ray
scattering over a significant portion of the reciprocal space and with
unprecedented accuracy. We observe that the absence of apical oxygens increases
the in-plane hopping range and, in CaCuO2, it leads to a genuine 3D
exchange-bond network. These results establish a corresponding relation between
the exchange interactions and the crystal structure, and provide fresh insight
into the materials dependence of the superconducting transition temperature.Comment: 9 pages, 4 figures, 1 Table, 42 reference
Coexistence of a colon carcinoma with two distinct renal cell carcinomas: a case report
<p>Abstract</p> <p>Introduction</p> <p>We present the case of a patient with two tumors in his left kidney and a synchronous colon cancer. While coexisting tumors have been previously described in the same kidney or the kidney and other organs, or the colon and other organs, to the best of our knowledge no such concurrency of three primary tumors has been reported in the literature to date.</p> <p>Case presentation</p> <p>A 72-year-old man of Greek nationality presenting with pain in the right hypochondrium underwent a series of examinations that revealed gallstones, a tumor in the hepatic flexure of the colon and an additional tumor in the upper pole of the left kidney. He was subjected to a right hemicolectomy, left nephrectomy and cholecystectomy, and his postoperative course was uneventful. Histopathology examinations showed a mucinous colon adenocarcinoma, plus two tumors in the left kidney, a papillary renal cell carcinoma and a chromophobe renal cell carcinoma.</p> <p>Conclusion</p> <p>This case underlines the need to routinely scan patients pre-operatively in order to exclude coexisting tumors, especially asymptomatic renal tumors in patients with colorectal cancer, and additionally to screen concurrent tumors genetically in order to detect putative common genetic alterations.</p
Spintronics: Fundamentals and applications
Spintronics, or spin electronics, involves the study of active control and
manipulation of spin degrees of freedom in solid-state systems. This article
reviews the current status of this subject, including both recent advances and
well-established results. The primary focus is on the basic physical principles
underlying the generation of carrier spin polarization, spin dynamics, and
spin-polarized transport in semiconductors and metals. Spin transport differs
from charge transport in that spin is a nonconserved quantity in solids due to
spin-orbit and hyperfine coupling. The authors discuss in detail spin
decoherence mechanisms in metals and semiconductors. Various theories of spin
injection and spin-polarized transport are applied to hybrid structures
relevant to spin-based devices and fundamental studies of materials properties.
Experimental work is reviewed with the emphasis on projected applications, in
which external electric and magnetic fields and illumination by light will be
used to control spin and charge dynamics to create new functionalities not
feasible or ineffective with conventional electronics.Comment: invited review, 36 figures, 900+ references; minor stylistic changes
from the published versio
Classification and evolutionary history of the single-strand annealing proteins, RecT, Redβ, ERF and RAD52
BACKGROUND: The DNA single-strand annealing proteins (SSAPs), such as RecT, Redβ, ERF and Rad52, function in RecA-dependent and RecA-independent DNA recombination pathways. Recently, they have been shown to form similar helical quaternary superstructures. However, despite the functional similarities between these diverse SSAPs, their actual evolutionary affinities are poorly understood. RESULTS: Using sensitive computational sequence analysis, we show that the RecT and Redβ proteins, along with several other bacterial proteins, form a distinct superfamily. The ERF and Rad52 families show no direct evolutionary relationship to these proteins and define novel superfamilies of their own. We identify several previously unknown members of each of these superfamilies and also report, for the first time, bacterial and viral homologs of Rad52. Additionally, we predict the presence of aberrant HhH modules in RAD52 that are likely to be involved in DNA-binding. Using the contextual information obtained from the analysis of gene neighborhoods, we provide evidence of the interaction of the bacterial members of each of these SSAP superfamilies with a similar set of DNA repair/recombination protein. These include different nucleases or Holliday junction resolvases, the ABC ATPase SbcC and the single-strand-binding protein. We also present evidence of independent assembly of some of the predicted operons encoding SSAPs and in situ displacement of functionally similar genes. CONCLUSIONS: There are three evolutionarily distinct superfamilies of SSAPs, namely the RecT/Redβ, ERF, and RAD52, that have different sequence conservation patterns and predicted folds. All these SSAPs appear to be primarily of bacteriophage origin and have been acquired by numerous phylogenetically distant cellular genomes. They generally occur in predicted operons encoding one or more of a set of conserved DNA recombination proteins that appear to be the principal functional partners of the SSAPs
What are the beliefs, attitudes and practices of front-line staff in long-term care (LTC) facilities related to osteoporosis awareness, management and fracture prevention?
<p>Abstract</p> <p>Background</p> <p>Compared to the general elderly population, those institutionalized in LTC facilities have the highest prevalence of osteoporosis and subsequently have higher incidences of vertebral and hip fractures. The goal of this study is to determine how well nurses at LTC facilities are educated to properly administer bisphosphonates. A secondary question assessed was the nurse's and PSW's attitudes and beliefs regarding the role and benefits of vitamin D for LTC patients.</p> <p>Methods</p> <p>Eight LTC facilities in Hamilton were surveyed, and all nurses were offered a survey. A total 57 registered nurses were surveyed. A 21 item questionnaire was developed to assess existing management practices and specific osteoporosis knowledge areas.</p> <p>Results</p> <p>The questionnaire assessed the nurse's and personal support worker's (PSWs) education on how to properly administer bisphosphonates by having them select all applicable responses from a list of options. These options included administering the drug before, after or with meals, given with or separate from other medications, given with juice, given with or without water, given with the patient sitting up, or finally given with the patient supine. Only 52% of the nurses and 8.7% of PSWs administered the drug properly, where they selected the options: (given before meals, given with water, given separate from all other medications, and given in a sitting up position). If at least one incorrect option was selected, then it was scored as an inappropriate administration. Bisphosphonates were given before meals by 85% of nurses, given with water by 90%, given separately from other medication by 71%, and was administered in an upright position by 79%. Only 52% of the nurses and 8.7% of PSWs surveyed were administering the drug properly. Regarding the secondary question, of the 57 nurses surveyed, 68% strongly felt their patients should be prescribed vitamin D supplements. Of the 124 PSWs who completed the survey, 44.4% strongly felt their patients should be prescribed vitamin D supplementation.</p> <p>Conclusion</p> <p>Bisphosphonates are quite effective in increasing the bone mineral density of LTC patients, and may reduce fracture rates, but it is only effective if properly administered. In our study, proper administration of bisphosphonate therapy was less than optimal. In summary, although the education of health providers has improved since the mid-1990's, this area still requires further attention and the subject of future quality assurance research.</p
Advances in Glucocorticoid-Induced Osteoporosis
Glucocorticoid-induced osteoporosis (GIOP) is one of the most important side effects of glucocorticoid use, as it leads to an increased risk of fractures. Recently, many published studies have focused on the cellular and molecular mechanisms of bone metabolism, the pathophysiology of GIOP, and the intervention options to prevent GIOP. In this review, recent advances in GIOP are summarized, particularly recent progress in our understanding of the mechanisms of GIOP resulting in improved insight that might result in the development of new treatment options in the near future
Inflammation Triggers Emergency Granulopoiesis through a Density-Dependent Feedback Mechanism
Normally, neutrophil pools are maintained by homeostatic mechanisms that require
the transcription factor C/EBPα. Inflammation, however, induces neutrophilia
through a distinct pathway of “emergency” granulopoiesis that is
dependent on C/EBPβ. Here, we show in mice that alum triggers emergency
granulopoiesis through the IL-1RI-dependent induction of G-CSF. G-CSF/G-CSF-R
neutralization impairs proliferative responses of hematopoietic stem and
progenitor cells (HSPC) to alum, but also abrogates the acute mobilization of BM
neutrophils, raising the possibility that HSPC responses to inflammation are an
indirect result of the exhaustion of BM neutrophil stores. The induction of
neutropenia, via depletion with Gr-1 mAb or myeloid-specific ablation of Mcl-1,
elicits G-CSF via an IL-1RI-independent pathway, stimulating granulopoietic
responses indistinguishable from those induced by adjuvant. Notably, C/EBPβ,
thought to be necessary for enhanced generative capacity of BM, is dispensable
for increased proliferation of HSPC to alum or neutropenia, but plays a role in
terminal neutrophil differentiation during granulopoietic recovery. We conclude
that alum elicits a transient increase in G-CSF production via IL-1RI for the
mobilization of BM neutrophils, but density-dependent feedback sustains G-CSF
for accelerated granulopoiesis
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