The 9vHPV vaccine prevented infection and disease related to HPV-31, 33, 45, 52, and 58 in a susceptible population and generated an antibody response to HPV-6, 11, 16, and 18 that was noninferior to that generated by the qHPV vaccine. The 9vHPV vaccine did not prevent infection and disease related to HPV types beyond the nine types covered by the vaccine. (Funded by Merck; ClinicalTrials.gov number, NCT00543543).

Using spin-density functional theory we investigated various possible structures of the hematite (0001) surface. Depending on the ambient oxygen partial pressure, two geometries are found to be particularly stable under thermal equilibrium: one being terminated by iron and the other by oxygen. Both exhibit huge surface relaxations (−57% for the Fe-and −79% for the O-termination) with important consequences for the surface electronic and magnetic properties. With scanning tunneling microscopy we observe two different surface terminations coexisting on single crystalline α-Fe2O3 (0001) films, which were prepared in high oxygen pressures.PACS numbers:68.35. Bs,61.16.Ch,68.35.Md,71.15.Ap Although metal-oxide surfaces play a crucial role for several profitable processes, good quality experimental and theoretical studies of their atomic structure and electronic properties are scarce. For example, α-Fe 2 O 3 appears to be the active catalytic material for producing styrene, 1 which was substantiated by recent reactivity studies performed over single crystalline hematite model catalyst films. 2 Other candidate applications are photoelectrodes 3 and non-linear optics materials 4 . Nevertheless, the surface properties of α-Fe 2 O 3 are basically unknown, and also for other metal oxides an understanding is developed only badly. The reason is the difficult preparation of clean surfaces with defined structures and stoichiometries, which, as in the case of hematite, can require high oxygen pressures not suitable in standard ultrahigh vacuum systems. Furthermore, electron spectroscopy techniques and scanning tunneling microscopy (STM) are hampered by the insulating nature of the material. We also note that surface-science techniques often do not probe a thermal equilibrium geometry but a frozen-in metastable state. Theoretical studies, on the other hand, have to deal with 3d electrons, oxygen with very localized wave functions, a rather open structure, unusual hybridization of wave functions, huge atomic relaxations, big super cells, and magnetism. This renders an ab initio study of α-Fe 2 O 3 surfaces a most challenging investigation. Some theoretical studies of the geometry of α-Fe 2 O 3 (0001) had been performed using empirical (classical) potentials 5,6 , and Armelao et al. 7 studied the electronic structure employing a cluster approach. In this paper we report spin-density functional theory (SDFT) calculations for a slab geometry (see Fig. 1). We use the generalized gradient approximation (GGA) 8 for the exchange-correlation functional and the full-potential linearized augmented plane wave (FP-LAPW) method 9,10 to solve the Kohn-Sham equations. The STM study was performed on a thin hematite film grown epitaxially onto a Pt (111) substrate.The identification of thermal equilibrium structures of surfaces is a prerequisite for an understanding of the endurance, electronic, magnetic, and chemical properties of the material. Upper half of the slab for the unrelaxed O3-terminated surface. The cross section of the upper half ...

BACKGROUNDThe investigational 9-valent viruslike particle vaccine against human papillomavirus (HPV) includes the HPV types in the quadrivalent HPV (qHPV) vaccine (6, 11, 16, and 18) and five additional oncogenic types (31, 33, 45, 52, and 58). Here we present the results of a study of the efficacy and immunogenicity of the 9vHPV vaccine in women 16 to 26 years of age. METHODSWe performed a randomized, international, double-blind, phase 2b-3 study of the 9vHPV vaccine in 14,215 women. Participants received the 9vHPV vaccine or the qHPV vaccine in a series of three intramuscular injections on day 1 and at months 2 and 6. Serum was collected for analysis of antibody responses. Swabs of labial, vulvar, perineal, perianal, endocervical, and ectocervical tissue were obtained and used for HPV DNA testing, and liquid-based cytologic testing (Papanicolaou testing) was performed regularly. Tissue obtained by means of biopsy or as part of definitive therapy (including a loop electrosurgical excision procedure and conization) was tested for HPV. RESULTSThe rate of high-grade cervical, vulvar, or vaginal disease irrespective of HPV type (i.e., disease caused by HPV types included in the 9vHPV vaccine and those not included) in the modified intention-to-treat population (which included participants with and those without prevalent infection or disease) was 14.0 per 1000 person-years in both vaccine groups. The rate of high-grade cervical, vulvar, or vaginal disease related to 33,45, 52, and 58 in a prespecified per-protocol efficacy population (susceptible population) was 0.1 per 1000 person-years in the 9vHPV group and 1.6 per 1000 person-years in the qHPV group (efficacy of the 9vHPV vaccine, 96.7%; 95% confidence interval, 80.9 to 99.8). Antibody responses to 11,16,and 18 were noninferior to those generated by the qHPV vaccine. Adverse events related to injection site were more common in the 9vHPV group than in the qHPV group. CONCLUSIONSThe 9vHPV vaccine prevented infection and disease related to 33,45, 52, and 58 in a susceptible population and generated an antibody response to HPV-6, 11, 16, and 18 that was noninferior to that generated by the qHPV vaccine. The 9vHPV vaccine did not prevent infection and disease related to HPV types beyond the nine types covered by the vaccine. (Funded by Merck; ClinicalTrials.gov number, NCT00543543).

The growth of iron-oxide films on Pt͑111͒ prepared by iron deposition and subsequent oxidation was studied by scanning tunneling microscopy ͑STM͒ and high-resolution low-energy electron diffraction ͑LEED͒. Despite a 10% lattice mismatch to the substrate, an epitaxial growth of well-ordered films is observed. The oxide starts to grow layer by layer in a ͑111͒ orientation of the metastable cubic FeO structure up to a thickness of about 2.2 monolayers ͑ML͒. The completion of the second and third FeO layer depends on the precise oxidation temperature, and at coverages of approximately 2 ML three-dimensional Fe 3 O 4 (111) islands start to grow. The FeO͑111͒ layers consist of hexagonal close-packed iron-oxygen bilayers that are laterally expanded when compared to bulk FeO and slightly rotated against the platinum substrate. They all exhibit oxygen-terminated unreconstructed (1ϫ1) surface structures. With increasing coverage several structural film changes occur, and four coincidence structures with slightly different lateral lattice constants and rotation misfit angles against the platinum substrate are formed. In the submonolayer regime an FeO͑111͒ bilayer with a lattice constant of 3.11 Å and rotated by 1.3°against the platinum substrate is observed. Upon completion of the first layer the film gets compressed leading to a lattice constant of 3.09 Å and a rotation misfit angle of 0.6°. Between 1.5 and 2 ML a coincidence structure rotated by 30°against the platinum substrate forms, and at 2 ML a nonrotated coincidence structure with a lattice constant of 3.15 Å evolves. All these coincidence structures exhibit large periodicities between approximately 22 and 38 Å that are visible in the STM images up to the third FeO layer surface. The LEED patterns exhibit characteristic multiple scattering satellite spots. The different coincidence structures reflect lowest-total-energy arrangements, balancing the contributions of substrate-overlayer interface energies and elastic energies within the strained oxide overlayer for each coverage. ͓S0163-1829͑98͒02311-X͔

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