Switching the crystalline phase of a material via electrostatic control is a proven strategy for developing memory devices such as memristors that are based on nonvolatile resistance switching phenomena. However, phase switching in atomic-scale systems is often difficult to control and poorly understood. Here, we explore nonvolatile switching of long 2.
View Article and Find Full Text PDFJ Phys Chem C Nanomater Interfaces
July 2021
The precise positioning of dopant atoms within bulk crystal lattices could enable novel applications in areas including solid-state sensing and quantum computation. Established scanning probe techniques are capable tools for the manipulation of surface atoms, but at a disadvantage due to their need to bring a physical tip into contact with the sample. This has prompted interest in electron-beam techniques, followed by the first proof-of-principle experiment of bismuth dopant manipulation in crystalline silicon.
View Article and Find Full Text PDFProspective data are limited on human papillomavirus (HPV) acquisition and clearance among circumcised men from resource-limited geographical regions, particularly Africa. The goal of this study was to estimate incidence and clearance of type-specific genital HPV infection in men. Penile exfoliated cell specimens were collected from the glans/coronal sulcus and shaft of 1,037 circumcised Kenyan men at baseline and 6-, 12- and 18-month follow-up visits between 2003-2007.
View Article and Find Full Text PDFLancet Oncol
February 2019
Background: Human papillomavirus (HPV) testing on self-collected samples is a potential alternative to HPV testing on clinician-collected samples, but non-inferiority of its clinical accuracy remains to be assessed in the regular screening population. The IMPROVE study was done to evaluate the clinical accuracy of primary HPV testing on self-collected samples within an organised screening setting.
Methods: In this randomised, non-inferiority trial, women aged 29-61 years were invited to participate in the study as part of their regular screening invitation in the Netherlands.
Based on scientific data showing that HPV testing provides better protection against cervical precancer and cancer than cytology, in 2011 the Dutch Health Council advised the Minister of Welfare, Health and Sports to replace cytology by HPV testing in the Dutch population-based screening programme. After a successful evaluation of the feasibility of HPV-based screening in 2014, primary HPV testing for cervical screening was implemented in 2017. The Netherlands has been one of the first countries worldwide to implement nationwide HPV-based screening and its experience with the new programme is therefore followed with great interest.
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