3,238 research outputs found
Thermodynamic Properties of Block Copolymer Electrolytes Containing Imidazolium and Lithium Salts
We report on the thermal properties, phase behavior, and thermodynamics of a series of polystyrene-block-poly(ethylene oxide) copolymers (SEO) mixed with the ionic species Li[N(SO_(2)CF_3)_2] (LiTFSI), imidazolium TFSI (ImTFSI), and an equimolar mixture of LiTFSI and ImTFSI (Mix). Differential scanning calorimetric scans reveal similar thermal behavior of SEO/LiTFSI and SEO/ImTFSI at the same salt concentrations. Phase behavior and thermodynamics were determined using a combination of small-angle X-ray scattering and birefringence. The thermodynamics of our mixtures can be mapped on to the theory of neat block copolymer phase behavior provided the FloryâHuggins interaction parameter, Ï, between the blocks is replaced by an effective Ï (Ï_(eff)) that increases linearly with salt concentration. The phase behavior and the value of m, the slope of the Ï_(eff) versus salt concentration data, were similar for SEO/LiTFSI, SEO/ImTFSI, and SEO/Mix blends. The theory developed by Wang [ J. Phys. Chem. B. 2008, 41, 16205] provides a basis for understanding the fundamental underpinnings of the measured value of m. We compare our experimental results with the predictions of this theory with no adjustable parameters
Nota previa sobre el Pérmico de la Cordillera Ibérica y bordes del Sistema Central
The principal stratigraphic characteristics from severa1 per- mian oatcrops from the Bordes del Macizo Central and Cor- dillera Ibérica are described here. The comparative study of these series, as well as the data apported by previous works allow certain conclusions about development of the sedimen- tation during the Permian and the limit between that system and the Trias
Pérmico continental en España
[ES] Los conocimientos que hasta el momento se poseen, indican que en España
el Pérmico estå representado por el «Autuniense» (Rotliegendes Inferior) en
facies grises caracterĂsticas y por formaciones rojas que son atribuidas al
«Saxoniense» (Rotliegendes Superior). El Pérmico Superior sólo ha sido citado
en muy escasos puntos.
En general, estĂĄ constituido por series detrĂticas, cuyo tamaño va desde
la arcilla, hasta conglomerados de gruesos bloques. Frecuentemente se intercalan
rocas volcĂĄnicas de diversos tipos. Su potencia es muy variable, pudiendo
llegar a alcanzar espesores de mĂĄs de 2.000 m. Su deposiciĂłn se realiza en
cuencas continentales condicionadas normalmente por la tectĂłnica tardihercinica.
Todas sus caracterĂsticas, asĂ como los problemas que plantea su cronoestratigrafia
son muy similares a los del PĂ©rmico de Europa Occidental.[FR] Les connaissances aujourdâhui acquisses indiquent quen Espagne, le Permien
est rĂ©presente par «lâAutunien» (Rotliegendes Infericur) en facies gris
characteritiques et par des formations rouges atribuées au «Saxonien» (Rotliegendes
Superieur). Le Permien Supericur a été identifle seulement dans
quelques points.
En general, les séries sont constituées par des seditnents détritiques, des
les argiles juqua les conglomerats; frequentment on trouve des passées
volcaniques de type divers.
Sa puissance est tres variable, jusqua 2.000 metres maximum; sa deposition
prend lieu dans bassins continentaux controlés normalement par la tectonique
tardihercynienne.
Ses characteritiques et ses problemes sont tres similaires a ceux du Permien
de lEurope Occidentale.[EN] The present data show that the Spanish Permian is represented by the
«Autunian» (Lower Rotliegendes) in a typical grey facies and redbeds similar
to the «Saxonian» (Upper Rotliegendes). The Upper Permian has been found
only in a very few points.
In general it is made of detrital series, from clays to conglomerates; some
volcanĂc levels are found.
Tickness is very variable, up to 2.000 meters. Sedimentation takes place in
continental basins, tectonically con troled 1w the tardihercynian pbases.
Their caracteristics and problenis are similar to the ones of Western European
Permian.Peer reviewe
duloxetine induced pseudolymphoma with features of lymphocytic infiltration of jessner kanof
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AntropoestratigrafĂa: nuevas unidades litolĂłgicas del Cuaternario controladas por la actividad humana
Many areas around the world such as the Mediterranean region have been inhabited without interruption for thousands of years. This is the case of the city of Barcelona (Spain), where remains of human settlements dating from pre-Roman times until the present have been found. A detailed geological mapping of the area occupied by the city of Barcelona raises a number of questions about the Holocene stratigraphy affected by human activity. In the old urban and surrounding areas most of the sedimentary deposits accumulated during settlement result from human interactions. Thus, new anthropostratigraphic units are proposed. The sedimentary deposits and the infill of rock excavations due to human presence may be divided into three categories: Natural lithoanthropogenic units (NAU) when their formation is not directly affected by anthropogenic activity but these contain artefacts of human origin. Induced lithoanthropogenic units (IAU) when natural processes together with human actions produce sedimentation or erosion due to natural phenomena; Constructed lithoanthropogenic units (CAU) when sedimentary accumulations and sharp contacts result from direct human activity.A lo largo de todo el globo terrestre, existen muchas zonas como la regiĂłn mediterrĂĄnea que han sido habitadas ininterrumpidamente durante miles de años. Este es el caso de la ciudad de Barcelona donde se han encontrado restos de asentamientos humanos desde los tiempos pre-romanos hasta la actualidad. Un mapa geolĂłgico detallado de la zona ocupada por la ciudad de Barcelona plantea una serie de interrogantes sobre la estratigrafĂa del Holoceno influenciado por la actividad humana. En la zona urbana antigua y en ĂĄreas circundantes, la mayorĂa de los depĂłsitos acumulados durante el asentamiento se han producido por las interacciones humanas. Por tanto, se proponen nuevas unidades antropoestratigrĂĄficas. Los depĂłsitos sedimentarios asĂ como los rellenos de lasexcavaciones debidos a la presencia humana pueden ser divididos en tres categorĂas: Unidades litoantropogĂ©nicas naturales (NAU) cuando su generaciĂłn no ha sido afectada directamente por la actividad humana, pero contienen diversos artefactos artificiales. Unidades litoantropogĂ©nicas inducidas (IAU) cuando los procesos naturales junto a las acciones humanas producen sedimentaciĂłn o erosiĂłn debido a los fenĂłmenos naturales. Unidades litoantropogĂ©nicas construidas (CAU) cuando las acumulaciones sedimentarias y los contactos nĂtidos son el resultado de la actividad humana directa
Long-living optical gain induced by solvent viscosity in a push-pull molecule
The combination of continuum and ultrafast pump-probe spectroscopy with DFT and TDDFT calculations, in viscous and non-viscous environments, is effective in unraveling important features of the twisted intramolecular charge transfer mechanism in a new push-pull molecule that possesses aggregation induced emission properties. Long-living optical gain is found when this mechanism is inhibited, highlighting the importance of the environment rigidity in the design of materials for photonic applications
Hidradenitis suppurativa: guidelines of the Italian Society of Dermatology and Venereology (SIDeMaST) for the use of anti-TNF-α agents.
Hidradenitis suppurativa (HS) is a chronic inflammatory skin disease characterized by nodules, abscesses and sinus tracts, primarily affecting the intertriginous areas. The occlusion of the upper part of the folliculopilosebaceous unit, leading to rupture of the sebofollicular canal with the consequent development of perifollicular lympho-histiocytic inflammation, is believed to be the initial pathogenic event in HS. Giving the chronic nature of HS, its destructive impact on social, working and daily life of patients, its management is often frustrating both for patients and physicians. The HS treatment choices are influenced by disease severity and its individual subjective impact. In this article, the Board of the Italian Society of Dermatology and Venereology (SIDeMaST) on HS has prepared a document focusing on the role of biologic drugs (anti-TNF-α) in HS management, providing also a flow-chart for HS handling and the inclusion and exclusion criteria for HS treatment with anti-TNF-α
Optic nerve head and fibre layer imaging for diagnosing glaucoma
Background
The diagnosis of glaucoma is traditionally based on the finding of optic nerve head (ONH) damage assessed subjectively by ophthalmoscopy or photography or by corresponding damage to the visual field assessed by automated perimetry, or both. Diagnostic assessments are usually required when ophthalmologists or primary eye care professionals find elevated intraocular pressure (IOP) or a suspect appearance of the ONH. Imaging tests such as confocal scanning laser ophthalmoscopy (HRT), optical coherence tomography (OCT) and scanning laser polarimetry (SLP, as used by the GDx instrument), provide an objective measure of the structural changes of retinal nerve fibre layer (RNFL) thickness and ONH parameters occurring in glaucoma.
Objectives
To determine the diagnostic accuracy of HRT, OCT and GDx for diagnosing manifest glaucoma by detecting ONH and RNFL damage.
Search methods
We searched several databases for this review. The most recent searches were on 19 February 2015.
Selection criteria
We included prospective and retrospective cohort studies and case-control studies that evaluated the accuracy of OCT, HRT or the GDx for diagnosing glaucoma. We excluded population-based screening studies, since we planned to consider studies on self-referred people or participants in whom a risk factor for glaucoma had already been identified in primary care, such as elevated IOP or a family history of glaucoma. We only considered recent commercial versions of the tests: spectral domain OCT, HRT III and GDx VCC or
Data collection and analysis
We adopted standard Cochrane methods. We fitted a hierarchical summary ROC (HSROC) model using the METADAS macro in SAS software. After studies were selected, we decided to use 2 x 2 data at 0.95 specificity or closer in meta-analyses, since this was the most commonly-reported level.
Main results
We included 106 studies in this review, which analysed 16,260 eyes (8353 cases, 7907 controls) in total. Forty studies (5574 participants) assessed GDx, 18 studies (3550 participants) HRT, and 63 (9390 participants) OCT, with 12 of these studies comparing two or three tests. Regarding study quality, a case-control design in 103 studies raised concerns as it can overestimate accuracy and reduce the applicability of the results to daily practice. Twenty-four studies were sponsored by the manufacturer, and in 15 the potential conflict of interest was unclear.
Comparisons made within each test were more reliable than those between tests, as they were mostly based on direct comparisons within each study. The Nerve Fibre Indicator yielded the highest accuracy (estimate, 95% confidence interval (CI)) among GDx parameters (sensitivity: 0.67, 0.55 to 0.77; specificity: 0.94, 0.92 to 0.95). For HRT measures, the Vertical Cup/Disc (C/D) ratio (sensitivity: 0.72, 0.60 to 0.68; specificity: 0.94, 0.92 to 0.95) was no different from other parameters. With OCT, the accuracy of average RNFL retinal thickness was similar to the inferior sector (0.72, 0.65 to 0.77; specificity: 0.93, 0.92 to 0.95) and, in different studies, to the vertical C/D ratio.
Comparing the parameters with the highest diagnostic odds ratio (DOR) for each device in a single HSROC model, the performance of GDx, HRT and OCT was remarkably similar. At a sensitivity of 0.70 and a high specificity close to 0.95 as in most of these studies, in 1000 people referred by primary eye care, of whom 200 have manifest glaucoma, such as in those who have already undergone some functional or anatomic testing by optometrists, the best measures of GDx, HRT and OCT would miss about 60 cases out of the 200 patients with glaucoma, and would incorrectly refer 50 out of 800 patients without glaucoma. If prevalence were 5%, e.g. such as in people referred only because of family history of glaucoma, the corresponding figures would be 15 patients missed out of 50 with manifest glaucoma, avoiding referral of about 890 out of 950 non-glaucomatous people.
Heterogeneity investigations found that sensitivity estimate was higher for studies with more severe glaucoma, expressed as worse average mean deviation (MD): 0.79 (0.74 to 0.83) for MD < -6 db versus 0.64 (0.60 to 0.69) for MD >=-6 db, at a similar summary specificity (0.93, 95% CI 0.92 to 0.94 and, respectively, 0.94; 95% CI 0.93 to 0.95; P < 0.0001 for the difference in relative DOR).
Authors' conclusions
The accuracy of imaging tests for detecting manifest glaucoma was variable across studies, but overall similar for different devices. Accuracy may have been overestimated due to the case-control design, which is a serious limitation of the current evidence base.
We recommend that further diagnostic accuracy studies are carried out on patients selected consecutively at a defined step of the clinical pathway, providing a description of risk factors leading to referral and bearing in mind the consequences of false positives and false negatives in the setting in which the diagnostic question is made. Future research should report accuracy for each threshold of these continuous measures, or publish raw data
PHENOMENOLOGY OF REVERSE-SHOCK EMISSION IN THE OPTICAL AFTERGLOWS OF GAMMA-RAY BURSTS
We use a parent sample of 118 gamma-ray burst (GRB) afterglows, with known redshift and host galaxy extinction, to separate afterglows with and without signatures of dominant reverse-shock emission and to determine which physical conditions lead to a prominent reverse-shock emission. We identify 10 GRBs with reverse shock signatures - GRBs 990123, 021004, 021211, 060908, 061126, 080319B, 081007, 090102, 090424 and 130427A. By modeling their optical afterglows with reverse and forward shock analytic light curves and using Monte Carlo simulations, we estimate the parameter space of the physical quantities describing the ejecta and circumburst medium. We find that physical properties cover a wide parameter space and do not seem to cluster around any preferential values. Comparing the rest-frame optical, X-ray and high-energy properties of the larger sample of non-RS-dominated GRBs, we show that the early-time (< 1ks) optical spectral luminosity, X-ray
afterglow luminosity and -ray energy output of our reverse-shock dominated sample do not differ significantly from the general population at early times. However, the GRBs with dominant reverse shock emission have fainter than average optical forward-shock emission at late time (> 10 ks). We
find that GRBs with an identifiable reverse shock component show high magnetization parameter RB = "B,r/"B,f ïżœ 2 â 104. Our results are in agreement with the mildly magnetized baryonic jet model of GRBs
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