Pregnancy and the Risk of Stroke Kittner, Steven J; Stern, Barney J; Feeser, Barbara R ...
The New England journal of medicine,
09/1996, Letnik:
335, Številka:
11
Journal Article
Recenzirano
Odprti dostop
Although it is widely believed that pregnancy and the period shortly after pregnancy are associated with an increased risk of stroke, quantitative data supporting this assumption are scant.
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Most of ...the studies of stroke and pregnancy have been based on a series of pregnancies at a single hospital
2
–
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or have not identified strokes among women of childbearing age who were not either pregnant or recently pregnant.
2
–
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There are few data on the risk of stroke in relation to the full range of outcomes of pregnancy (spontaneous or induced abortion, stillbirth, and live birth). the one population-based study of . . .
The phase-change (PC) materials in the majority of optical data storage media in use today exhibit a fast, reversible crystal → amorphous phase transition that allows them to be switched between on ...(1) and off (0) binary states. Solid-state inorganic materials with this property are relatively common, but those exhibiting an amorphous → amorphous transition called polyamorphism are exceptionally rare. K
Sb
Se
(KSS) reported here is the first example of a material that has both amorphous → amorphous polyamorphic transition and amorphous → crystal transition at easily accessible temperatures (227 and 263 °C, respectively). The transitions are associated with the atomic coordinative preferences of the atoms, and all three states of K
Sb
Se
are stable in air at 25 °C and 1 atm. All three states of K
Sb
Se
exhibit distinct optical bandgaps, E
= 1.25, 1.0, and 0.74 eV, for the amorphous-II, amorphous-I, and crystalline versions, respectively. The room-temperature electrical conductivity increases by more than 2 orders of magnitude from amorphous-I to -II and by another 2 orders of magnitude from amorphous-II to the crystalline state. This extraordinary behavior suggests that a new class of materials exist which could provide multistate level systems to enable higher-order computing logic circuits, reconfigurable logic devices, and optical switches.
We present a new measurement of the difference between the nucleon strange and antistrange quark distributions from dimuon events recorded by the NuTeV experiment at Fermilab. This analysis is the ...first to use a complete next to leading order QCD description of charm production from neutrino scattering. Dimuon events in neutrino deep inelastic scattering allow direct and independent study of the strange and antistrange content of the nucleon. We find a positive strange asymmetry with a significance of 1.6sigma. We also report a new measurement of the charm mass.
The NuTeV Collaboration has extracted the electroweak parameter sin(2)theta(W) from the measurement of the ratios of neutral current to charged current nu and (-)nu cross sections. Our value, ...sin(2)theta((on-shell))(W) = 0.2277 +/- 0.0013(stat) +/- 0.0009(syst), is 3 standard deviations above the standard model prediction. We also present a model independent analysis of the same data in terms of neutral-current quark couplings.
In this article, we report the design, fabrication, characterization, and simulation of three-dimensional (3D) dye-sensitized solar cells (DSSCs), using ordered indium–tin-oxide (ITO) nanorod (NR) ...arrays as the photoanode, and compare them with conventional planar (2D) DSSCs. The ITO NR array used in the 3D cell greatly improves its performance by providing shorter electron pathways and reducing the recombination rate of the photogenerated electrons. We observed a 10–20% enhancement of the energy conversion efficiency, primarily due to an increased short circuit current. This finding supports the concept of using 3D photoanodes with optically transparent and conducting nanorods for the enhancement of the energy-harvesting devices that require short charge collection distance without sacrificing the optical thickness. Thus, unlike the conventional solar cell structure, the functions for photon collection and charge transport are decoupled to allow for improved cell designs.
A solid-phase microextraction method for phenols that is faster, more accurate and safer than current standard procedures is developed. The method has uses in wastewater treatment applications.
Solid-phase micro-extraction (SPME) uses coated fused-silica fibres to extract analytes from aqueous solution for subsequent determination by gas chromatography. The syringe assembly used in SPME is ...illustrated. An SPME method using poly(acrylate)-coated fibres was developed as a possible alternative to existing U.S. EPA methods for determination of phenols. The limits of detection were typically at nanograms per litre. The sensitivity of the method increased at low pH value and with addition of salt. Detection limits and precision of this method for various phenolic compounds are compared with those obtained by other procedures. Results obtained on a polluted groundwater and a pulp and paper mill effluent are presented.
Reinforced self‐assembled nano‐dielectrics (R‐SANDs) are fabricated by depositing a thin protective layer on high‐capacitance SAND films, thus significantly improving SAND durability and expanding ...SAND compatibility with a broader range of semiconductor deposition techniques. Fully transparent TFTs with excellent field‐effect mobilities ∼140 cm2/V·s and low operating voltages ∼1.0 V are demonstrated by combining the R‐SAND and an amorphous Zn‐In‐Sn‐O transparent oxide semiconductor.
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