tant was decanted. This peptization step was repeated 3±4 times. Finally, the combined supernatants were centrifuged at 12 500g for 5 min and the weakly opalescent colorless supernatant, containing the smallest nanoparticles, was carefully decanted.Thin fibers of LaPO 4 :Eu were synthesized in acidic solution as follows: A solution of La(NO 3 ) 3 ×6H 2 O (12.34 g; 28.5 mmol) and Eu(NO 3 ) 3 ×5H 2 O (0.642 g; 1.5 mmol) in water (100 mL) was adjusted to pH 4.5 and combined with stirring with (NH 4 ) 2 HPO 4 (3.96 g; 30 mmol) dissolved in water (100 mL). The resulting suspension having pH 1.7 was poured into a Teflonlined autoclave (Berghof, HR-500) and treated as described above.Similarly, fibers of LaPO 4 :Ce(5 %) and La 0.4 Ce 0.45 Tb 0.15 PO 4 were prepared by employing a total amount of 30 mmol of the respective nitrates. Prior to heating, the suspension in the autoclave was purged with forming gas (N 2 :H 2 = 9:1) for 60 min, in order to prevent oxidation of Ce 3+ to Ce 4+ .Powders of the nanoparticles were obtained from the colloidal solutions by removing the water with a rotary evaporator (bath temperature 50 C).Transmission electron micrographs of the samples were taken using a Philips CM 300 UT electron microscope, working at 300 kV acceleration voltage. A Philips Xpert system was used to measure the X-ray diffraction pattern of powder samples.UV-vis absorption spectra of the colloidal solutions were recorded with a Lambda 40 spectrometer (Perkin±Elmer). Photoluminescence spectra were recorded with a Spex Fluoromax 2 spectrometer having a spectral resolution of 0.5 nm.[**] We thank the Royal Society (YQZ, WKH, MT), the DERA (NG), Conacyt-MØxico and DGAPA-UNAM IN 107-296 (HT), and the EPSRC for financial support. We are grateful to J. Thorpe and D. Randall (Sussex) for assistance with TEM and SEM facilities.

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IMPORTANCEPrehospital delay (time from symptom onset of stroke to the door of a hospital) in patients with stroke is long in China. With the goal of improving public awareness and knowledge of stroke recognition, Stroke 1-2-0 was developed in China as an education program to prompt rapid response to the onset of stroke based on clinical practice in China, and examination of its outcomes is needed. OBJECTIVE To investigate the association of the Stroke 1-2-0 educational campaign with prehospital delay for patients with ischemic stroke. DESIGN, SETTING, AND PARTICIPANTSIn a population-based cross-sectional study, all patients with ischemic stroke events were admitted to the Minhang Hospital, which is the only tertiary care hospital with a stroke center that provides acute stroke care in Xinzhuang county, Shanghai, China.

Reports reveal that the piezoresistance coefficients of silicon carbide (SiC) nanowires (NWs) are 2 to 4 times smaller than those of their corresponding bulk counterparts. It is a challenge to eliminate contamination in adhering NWs onto substrates. In this study, a new setup was developed, in which NWs were manipulated and fixed by a goat hair and conductive silver epoxy in air, respectively, in the absence of any depositions. The goat hair was not consumed during manipulation of the NWs. The process took advantage of the stiffness and tapered tip of the goat hair, which is unlike the loss issue of beam sources in depositions. With the new fixing method, in situ transmission electron microscopy (TEM) electromechanical coupling measurements were performed on pristine SiC NWs. The piezoresistance coefficient and carrier mobility of SiC NW are −94.78 × 10 −11 Pa −1 and 30.05 cm 2 V −1 s −1 , respectively, which are 82 and 527 times respectively greater than those of SiC NWs reported previously. We, for the first time, report that the piezoresistance coefficient of SiC NW is 17 times those of its bulk counterparts. These findings provide new insights to develop high performance SiC devices and to help avoid catastrophic failure when working in harsh environments.