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Decisions to treat large-vessel occlusion with endovascular therapy (EVT) or intravenous alteplase depend on how physicians weigh benefits against risks when considering patients’ comorbidities. We explored EVT/alteplase decision-making by stroke experts in the setting of comorbidity/disability.
In an international multi-disciplinary survey, experts chose treatment approaches under current resources and under assumed ideal conditions for 10 of 22 randomly assigned case scenarios. Five included comorbidities (cancer, cardiac/respiratory/renal disease, mild cognitive impairment [MCI], physical dependence). We examined scenario/respondent characteristics associated with EVT/alteplase decisions using multivariable logistic regressions.
Among 607 physicians (38 countries), EVT was chosen less often in comorbidity-related scenarios (79.6% under current resources, 82.7% assuming ideal conditions) versus six “level-1A” scenarios for which EVT/alteplase was clearly indicated by current guidelines (91.1% and 95.1%, respectively, odds ratio [OR] [current resources]: 0.38, 95% confidence interval 0.31–0.47). However, EVT was chosen more often in comorbidity-related scenarios compared to all other 17 scenarios (79.6% versus 74.4% under current resources, OR: 1.34, 1.17–1.54). Responses favoring alteplase for comorbidity-related scenarios (e.g. 75.0% under current resources) were comparable to level-1A scenarios (72.2%) and higher than all others (60.4%). No comorbidity independently diminished EVT odds when considering all scenarios. MCI and dependence carried higher alteplase odds; cancer and cardiac/respiratory/renal disease had lower odds. Being older/female carried lower EVT odds. Relevant respondent characteristics included performing more EVT cases/year (higher EVT-, lower alteplase odds), practicing in East Asia (higher EVT odds), and in interventional neuroradiology (lower alteplase odds vs neurology).
Moderate-to-severe comorbidities did not consistently deter experts from EVT, suggesting equipoise about withholding EVT based on comorbidities. However, alteplase was often foregone when respondents chose EVT. Differences in decision-making by patient age/sex merit further study.
Flash type electronic memories are the preferred format in code storage at complex programs running on fast processors and larger media files in portable electronics due to fast write/read operations, long rewrite life, high density and low cost of fabrication. Scaling limitations of top-down fabrication approaches can be overcome in next generation flash memories by replacing continuous floating gate with array of nanocrystals. Germanium (Ge) is a good candidate for nanocrystal based flash memories due its small band gap. In this work, we present effect of silicon dioxide (SiO2) host matrix density on Ge nanocrystals morphology. Low density Ge+SiO2 layers are deposited between high density SiO2 layers by using off-angle magnetron sputter deposition. After high temperature post-annealing, faceted and elongated Ge nanocrystals formation is observed in low density layers. Effects of Ge concentration and annealing temperature on nanocrystal morphology and mean size were investigated by using transmission electron microscopy. Positive correlation between stress development and nanocrystal size is observed at Raman spectroscopy measurements. We concluded that non-uniform stress distribution on nanocrystals during growth is responsible from faceted and elongated nanocrystal morphology.
We present recent results on the carbon chemistry in photodissociation regions. We show that carbon chains and rings (CCH, c-C$_3$H$_2$ and C$_4$H) are tightly spatially correlated with each other, and with the mid-infrared emission due to PAHs (7 and 15 $\mu$m), mapped by ISOCAM. Neither the spatial distribution, nor the abundances of these species can be fit by state-of-the-art PDR models, which calls for another production mechanism. We discuss model predictions for carbon clusters and simple hydrocarbons. We show how selected abundance ratios can be used as a diagnostic of the physical conditions. We stress the need for more theoretical and laboratory work on fundamental processes relevant for the interstellar medium, which should be taken into account in the astrochemical models, but whose rates are not known accurately enough.
Maya Lowlands climate researchers have set aside earlier beliefs
that Maya civilization flourished in an unchanging environment.
Analyses of river discharge, weather patterns, lake-bottom
sediments, and settlement patterns reveal a highly variable
climate, considerable diversity in local geology and soils,
and a wide range of cultural adaptations tailored to distinctive
subregional settings. Significant knowledge gaps remain. Among
the unanswered questions is how cities in the elevated interior
were maintained without natural, permanent bodies of water even
during equitable climatic conditions, much less through the
episodes of severe drought that have become apparent in studies
of past climates. The research reported in this article lays
the groundwork for climate studies in the southwestern Yucatan
The small effective mass and high mobility of electrons in Bi, make Bi nanowires a promising system for thermoelectric applications. Dense arrays of 20–200 nm diameter Bi nanowires were fabricated by high pressure injection of the melt. Transport properties and Seebeck coefficient were investigated for Bi nanowires with various wire diameters as a function of temperature (1 K < T < 300 K) and magnetic fields (B < 0.6 T). We discuss the problem of the contact resistance of Bi nanowire arrays.
We discuss our rational approach to incorporate optically nonlinear molecules into polymeric and cross-linked materials through the use of isocyanate-hydroxy coupling chemistry. Thin film fabrication, optical loss, poling, second harmonic generation, and electro-optic properties are discussed.
Three modes of instabilities in the slit-jet flow field are recognized. Additional evidence for the universality of the Strouhal number for the second mode ST = fw/U0 ≈ 0.43 and additional information on the wavelength (λ) between, and convection speed uc of the symmetrically placed, large-scale motions that result from this instability are presented. Specifically λ/w ≈ 1.2 and uc/U0 ≈ 0.51. The third instability mode is initiated at a Reynolds number U0w/v of approximately 1600; this instability results in a loss of the regular pattern associated with the large-scale motions.
Peptidic neurones may be considered as multisignal integrators and transducers. When formation or release of peptide outstrips genetically determined breakdown capacity, overflow of peptides to the body fluids and urine may be expected. In this paper, pathological urinary chromatographic patterns of peptides are shown for genetic, functional and mixed disorders. Part symptoms of the disorders may be induced with the biologically isolated and purified peptides as well as with chemically synthesized peptides.
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