113 research outputs found
An adaptive inelastic magnetic mirror for Bose-Einstein condensates
We report the reflection and focussing of a Bose-Einstein condensate by a new
pulsed magnetic mirror. The mirror is adaptive, inelastic, and of extremely
high optical quality. The deviations from specularity are less than 0.5 mrad
rms, making this the best atomic mirror demonstrated to date. We have also used
the mirror to realize the analog of a beam-expander, producing an ultra-cold
collimated fountain of matter wavesComment: 4 pages, 4 figure
Immediate versus deferred initiation of androgen deprivation therapy in prostate cancer patients with PSA-only relapse. An observational follow-up study
BackgroundThe optimal timing to start androgen deprivation therapy (ADT) in prostate cancer patients with rising prostate-specific antigen (PSA) as the only sign of relapse is unknown.MethodsWe identified men with prostate cancer in the Cancer of the Prostate Strategic Urologic Research Endeavour (CaPSURE) study who would have been eligible (⩽ cT3aN0M0, primary radical prostatectomy or radiotherapy, PSA relapse as the only evidence of recurrence) for a randomised trial comparing 'immediate' versus 'deferred' ADT initiation. We emulated such trial by assigning patients to the 'immediate' strategy if they initiated ADT within 3 months of PSA relapse and to the 'deferred' strategy if they initiated ADT when they presented with metastasis, symptoms or a short PSA doubling time. We censored patients when they deviated from the assigned strategy and adjusted for this censoring via inverse probability weighting.ResultsOf 2096 eligible patients (median age 69, interquartile range 63-75 years), 88% were white, 35% had a Gleason score ⩾ 7, 69% were treated with radical prostatectomy and 31% received radiotherapy only as primary treatment. The mean time from primary treatment to PSA relapse was 37.4 (standard deviation [SD] 34.2) months. Mean follow-up from primary treatment was 91.4 (SD 48.4) months. The adjusted mortality hazard ratio for immediate versus deferred ADT was 0.91 (95% confidence interval (CI), 0.52-1.60), which would be translated into a similar 5-year survival (difference between groups: -2.0% (95% CI: -10.0 to 5.9%).ConclusionOur analysis suggests that prostate cancer patients undergoing immediate ADT initiation within three months after PSA-only relapse had similar survival to those who deferred ADT initiation within 3 months after clinical progression
Surface strategies for control of neuronal cell adhesion: A review
Material engineering methods have been used for many years to develop biomedical devices for use within the body to augment, repair or replace damaged tissues ranging from contact lenses to heart valves. Here we review the findings gathered from the wide and varied surface analytical approaches applied to study the interaction between biology and man-made materials. The key material characteristics identified to be important for biological recognition are surface chemistry, topography and compliance. Model surfaces with controlled chemistry and topography have provided insight into biological response to various types of topographical features over a wide range of length scales from nano to micrometres, along with 3D matrices that have been used as scaffolds to support cells for tissue formation. The cellular response to surfaces with localised areas of patterned chemistry and to those presenting gradually changing chemistry are discussed. Where previous reviews have been structured around specific classes of surface modification, e. g. self-assembly, or have broadly examined the response of various cells to numerous surfaces, we aim in this article to focus in particular on the tissues involved in the nervous system whilst providing a broad overview of key issues from the field of cell and protein surface interactions with surfaces. The goal of repair and treatment of diseases related to the central and peripheral nervous systems rely on understanding the local interfacial environment and controlling responses at the cellular level. The role of the protein layer deposited from serum containing media onto man-made surfaces is discussed. We highlight the particular problems associated with the repair of the nervous system, and review how neuronal attachment and axon guidance can be accomplished using various surface cues when cultured with single and multiple cell types. We include a brief glossary of techniques discussed in the body of this article aimed at the biologist without a surface science background with appropriate references for advanced reading in this area
Effect of Taper Angle on Wall Shear Stress at Tapered Right-Angle Branch in Laminar Steady Flow
Electron beam lithography using plasma polymerized hexane as resist
We present electron beam lithography using thin layers of plasma polymerized hexane as resist, as an alternative for conventional spincoated resists. Hexane is chosen due to the possible bioapplications, as well as the relatively simple polymerization chemistry. Successful patterning of micro- and nanopatterns are achieved with doses of 5000-25000 mu C cm(-2). Resist polarity is negative and features with a linewidth down to 150 nm are obtained. The patterns have also been used as a mask for a subsequent etch of silicon, with a selectivity comparable to PMMA, and as the base for a lift-off process
Variation in the provision and composition of multidisciplinary teams in rheumatology services across the UK: A cross-sectional study
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