A high mortality rate of approximately 20% in pregnant women with hepatitis E has been reported in previous studies. However, other studies showed no difference between pregnant and nonpregnant women in the severity of hepatitis E. To determine the effects of HEV infection on pregnancy, we successfully established HEV infection in six pregnant rabbits (PR) and six nonpregnant rabbits (NPR) with a rabbit HEV isolate, taking three PR and one NPR without HEV infection as controls. Tests for HEV RNA by RT-PCR, anti-HEV antibodies by ELISA and HEV antigen via immunohistochemistry and histopathology were carried out. Two of six infected PR miscarried and three of the remaining four PR died which may be attributed to severe liver necrosis caused by HEV infection. Moreover, vertical transmission was found to be associated with the replication of HEV in placenta, indicated by the presence of HEV RNA and antigen in placenta from the infected PR. Our findings strongly suggest that HEV infection could lead to adverse outcomes in pregnancy and vertical transmission, suggesting the necessity for pregnant women at risk of HEV infection to be vaccinated.

FeCo-codoped ZnO nanowires were synthesized by in situ doping with iron and cobalt using a chemical vapor deposition method. Structure and compositional analysis indicated that the as-prepared nanowires were single- crystalline and FeCo codoped. No FeCo clusters and other secondary phases were found in the nanowires. A Curie temperature higher than 300 K was observed from the as-doped nanowires. The room temperature ferromagnetic properties of the synthesized Zn1−x(FeCo)xO nanowire make it useful in future spintronic devices.

But to date, the performance of these devices is still low, not because of the low amount of energy generated in the cell-actually that is quite decent-but due to the diffi culty of collecting it: the main problem relies on the electrode/nanowires interfaces, specially the top one, which is mechanically mounted on the NWs. Traditionally, piezoelectric nanogenerators have been fabricated using all kind of materials as top electrode, including electronic polymers, [ 7,8 ] Au-coated polyethersulfone (PES), [ 9 ] and Cr-coated Al 2 O 3 [ 10 ] or Pt-coated Silicon [ 11 ] stacks, but they are unable to physically contact all the nanowires (a rigid top electrode can only contact the tallest NWs), therefore wasting much energy. Xu et al. [ 10 ] optimized the performance of these devices by tuning the morphology of the top electrode and, more specifi cally, he used the paired nanotip-to-nanowire brushes to provide a better nanowires/electrode interface. Wang and his co-workers used Poly-methyl methacrylate (PMMA) to improve the mechanical stability of the entire cell. [ 11 ] But, even if these techniques increase the performance of the cell, the nanowires may lose a high degree of mobility. Recently, Choi et al. [ 4 ] suggested that the use of a graphene/PEN (polyethylene naphthalate) electrode can improve the effi ciency of these devices due to the high carriers' mobility of graphene. In their prototype the nanowires were fi rst directly grown on a graphene/PEN structure, and the top graphene electrode was later integrated: the graphene was fi rst transferred to a different PEN substrate and then the cell was mounted. However, this methodology can bring about a major associated problem: the low density of nanowires (≈6%) that actually contact the top electrode, which results in a large contact resistance. [ 4,9 ] In this work, we present a novel cell that overtakes the performance of all designs previously reported by directly transferring a graphene sheet on top of the nanowires before mounting the top electrode. The conductive and fl exible graphene fl ake can perfectly adapt to the rough topography of the nanowires, contacting up to ≈73% of all the nanowires. Moreover the high fl exibility of the graphene top electrode introduces spring-like effects and, as a result, the novel cells show higher currents during longer times. Figure 1 shows the schematic of the fabrication method we followed to build the nanogenerators. First, the nanowires were vertically grown on a silicon substrate (Figure 1 a) using the hydrothermal method to synthesize zinc oxide nanowire array [ 12 ] (see the Experimental Section). In the next step a sheet of graphene is directly transferred on the nanowires (Figure 1 b), and fi nally a rigid copper top electrode is mounted to form the nanogenerator (Figure 1 c). Figure 2 a,b shows the typical top and cross-sectional scanning electron microscope images of the nanowires (respectively), revealing that their diameters range from 20 to 100 nm and their typical height is ≈3 µm. TheFinding new methods t...

This study focuses on the fabrication of two nanodevice prototypes which utilized vertical and horizontal carbon nanotubes used the focused ion beam to localize the catalysts, followed by plasma-enhanced chemical vapor deposition. First, metal-gated carbon nanotube field emitter arrays were fabricated on multilayer substrates containing an imbedded catalyst layer. Second, horizontally aligned single-walled carbon nanotubes were grown on a transmission electron microscopy grid. This allows the carbon nanotubes to be directly analyzed in a transmission electron microscope. It is expected that the methodology introduced here will open up opportunities for the direct fabrication of carbon nanotube based nanodevices.