10:1, 55 nm) and was deposited by the co-evaporation of magnesium and silver metals, with deposition rates of 5 and 0.5 s ±1 , respectively. The other was LiF/ Al and was deposited by first evaporating LiF (0.5 nm) at a deposition rate of 0.1 s ±1 and then evaporating aluminum (400 nm) at a rate of 1±2 s ±1 . The cathode was then capped with silver metal (100 nm) by evaporating silver at a rate of 3 s ±1 . The effective area of the emitting diode was 9.00 mm 2 . Current, voltage, and light-intensity measurements were made simultaneously using a Keithley 2400 source meter and a Newport 1835-C optical meter equipped with a Newport 818-ST silicon photodiode. All chemicals used for EL devices were sublimed in vacuum prior to use.[**] Research sponsored by MDI N00014-95-1-1116 for the Office of Naval Research, NSF, and NASA. Fig. 1. a) SEM image of ZnS nanobelts and nanosaws grown from an alumina substrate. b,c) Distribution of the ZnS nanobelts on the substrate surface suggesting a ªweed growthº model.

Patients with Crohn’s disease commonly develop ileal and less commonly colonic strictures, containing various degrees of inflammation and fibrosis. While predominantly inflammatory strictures may benefit from a medical anti-inflammatory treatment, predominantly fibrotic strictures currently require endoscopic balloon dilation or surgery. Therefore, differentiation of the main components of a stricturing lesion is key for defining the therapeutic management. The role of endoscopy to diagnose the nature of strictures is limited by the superficial inspection of the intestinal mucosa, the lack of depth of mucosal biopsies and by the risk of sampling error due to a heterogeneous distribution of inflammation and fibrosis within a stricturing lesion. These limitations may be in part overcome by cross-sectional imaging techniques such as ultrasound, CT and MRI, allowing for a full thickness evaluation of the bowel wall and associated abnormalities. This systematic literature review provides a comprehensive summary of currently used radiologic definitions of strictures. It discusses, by assessing only manuscripts with histopathology as a gold standard, the accuracy for diagnosis of the respective modalities as well as their capability to characterise strictures in terms of inflammation and fibrosis. Definitions for strictures on cross-sectional imaging are heterogeneous; however, accuracy for stricture diagnosis is very high. Although conventional cross-sectional imaging techniques have been reported to distinguish inflammation from fibrosis and grade their severity, they are not sufficiently accurate for use in routine clinical practice. Finally, we present recent consensus recommendations and highlight experimental techniques that may overcome the limitations of current technologies.

We report the first successful synthesis and characterization of single-crystal wurtzite CdSe nanoribbons through a simple thermal evaporation process. Asymmetric growth of the nanoribbons occurs, yielding a sawlike shape with sharp teeth on one side. This asymmetric growth is suggested to be induced by the polarization of the c-plane in the wurtzite crystal structure.

Consensus criteria for diagnosis and response to therapy in stricturing Crohn's disease should inform both clinical practice and trial design.

Ustekinumab is an effective therapeutic option for inducing and maintaining clinical, endoscopic and radiographic response in patients with Crohn's disease failing anti-TNF therapy.