266 research outputs found
The Application of VR Technology in E-Commerce
Virtual reality (VR) technology is continually being developed and is used in all walks of life. VR has become the key to innovation and development and not only a mode of providing entertainment - one of which is e-commerce. The goal of integrating VR technology into is to ensure that people can enhance the effectiveness of information at the content level of goods, the formal level to give users a new experience. To implement changes within e-commerce, this paper explores the current state-of-the-art with respect to VR technology in e-commerce application, and postulates relevant recommendations
Local step-flow dynamics in thin film growth with desorption
Desorption of deposited species plays a role in determining the evolution of
surface morphology during crystal growth when the desorption time constant is
short compared to the time to diffuse to a defect site, step edge or kink.
However, experiments to directly test the predictions of these effects are
lacking. Novel techniques such as \emph{in-situ} coherent X-ray scattering can
provide significant new information. Herein we present X-ray Photon Correlation
Spectroscopy (XPCS) measurements during diindenoperylene (DIP) vapor deposition
on thermally oxidized silicon surfaces. DIP forms a nearly complete
two-dimensional first layer over the range of temperatures studied (40 - 120
C), followed by mounded growth during subsequent deposition. Local
step flow within mounds was observed, and we find that there was a
terrace-length-dependent behavior of the step edge dynamics. This led to
unstable growth with rapid roughening () and deviation from a
symmetric error-function-like height profile. At high temperatures, the grooves
between the mounds tend to close up leading to nearly flat polycrystalline
films. Numerical analysis based on a 1 + 1 dimensional model suggests that
terrace-length dependent desorption of deposited ad-molecules is an essential
cause of the step dynamics, and it influences the morphology evolution.Comment: 21 pages, 9 figures, and one tabl
Primary adenomyoepithelioma of tonsil
We present a case of adenomyoepithlioma (AME) arising from the tonsil. AME is an uncommon tumor that typically arises in breast, but rarely found in salivary glands, lung, and skin. Its biological features have not been thoroughly characterized. Here we describe a primary AME originating from the tonsil. The pathologic changes were characterized by hypercellularity, the dominance of both epithelial and myoepithelial cells. Malignancy was evidenced by the presence of a high mitotic rate and invasive growth. The epithelial cells express high levels of cytokeratin and epithelial membrane antigen (EMA). The myoepithelial cells show positive staining for calponin, p63, vimentin, and S-100. A thorough review of the literature indicates that this is likely the first reported case of AME from the tonsil. Following descriptions of the diagnosis, treatment, and prognosis of this specific case, pathologic and clinical characteristics of AME from other tissues are also compiled and discussed
Envelope Deglycosylation Enhances Antigenicity of HIV-1 gp41 Epitopes for Both Broad Neutralizing Antibodies and Their Unmutated Ancestor Antibodies
The HIV-1 gp41 envelope (Env) membrane proximal external region (MPER) is an important vaccine target that in rare subjects can elicit neutralizing antibodies. One mechanism proposed for rarity of MPER neutralizing antibody generation is lack of reverted unmutated ancestor (putative naive B cell receptor) antibody reactivity with HIV-1 envelope. We have studied the effect of partial deglycosylation under non-denaturing (native) conditions on gp140 Env antigenicity for MPER neutralizing antibodies and their reverted unmutated ancestor antibodies. We found that native deglycosylation of clade B JRFL gp140 as well as group M consensus gp140 Env CON-S selectively increased the reactivity of Env with the broad neutralizing human mAbs, 2F5 and 4E10. Whereas fully glycosylated gp140 Env either did not bind (JRFL), or weakly bound (CON-S), 2F5 and 4E10 reverted unmutated ancestors, natively deglycosylated JRFL and CON-S gp140 Envs did bind well to these putative mimics of naive B cell receptors. These data predict that partially deglycoslated Env would bind better than fully glycosylated Env to gp41-specific naïve B cells with improved immunogenicity. In this regard, immunization of rhesus macaques demonstrated enhanced immunogenicity of the 2F5 MPER epitope on deglyosylated JRFL gp140 compared to glycosylated JRFL gp140. Thus, the lack of 2F5 and 4E10 reverted unmutated ancestor binding to gp140 Env may not always be due to lack of unmutated ancestor antibody reactivity with gp41 peptide epitopes, but rather, may be due to glycan interference of binding of unmutated ancestor antibodies of broad neutralizing mAb to Env gp41
Initial antibodies binding to HIV-1 gp41 in acutely infected subjects are polyreactive and highly mutated
Many HIV-1 envelope-reactive antibodies shortly after HIV-1 transmission may arise from crow-reactive memory B cells previously stimulated by non-HIV-1 host or microbial antigen
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