Abstract Purpose Bariatric surgery is recognized as the treatment of choice for class III obesity (body mass index ≥40) and has been increasingly recommended for obese patients. Prior research has ...suggested an excess of deaths due to suicide following bariatric surgery, but few large long-term follow-up studies exist. We examined postbariatric surgery suicides by time since operation, sex, age, and suicide death rates as compared with US suicide rates. Methods Medical data following bariatric operations performed on Pennsylvania residents between January 1, 1995 and December 31, 2004 were obtained from the Pennsylvania Health Care Cost and Containment Council. Matching mortality data from suicides between September 1, 1996 and December 28, 2006 were obtained from the Division of Vital Records, Pennsylvania State Department of Health. Results There were 31 suicides (16,683 operations), for an overall rate of 6.6/10,000; 13.7 per 10,000 among men and 5.2 per 10,000 among women. About 30% of suicides occurred within the first 2 years following surgery, with almost 70% occurring within 3 years. For every age category except the youngest, suicide rates were higher among men than women. Age- and sex-matched suicide rates in the US population (ages 35-64 years) were 2.4/10,000 (men) and 0.7/10,000 (women). Conclusions Compared with age and sex-matched suicide rates in the US, there was a substantial excess of suicides among all patients who had bariatric surgery in Pennsylvania during a 10-year period. These data document a need to develop more comprehensive longer-term surveillance and follow-up methods in order to evaluate factors associated with postbariatric surgery suicide.
Recent advances in proteomic technologies have made high throughput profiling of low abundance proteins in large epidemiological cohorts increasingly feasible. We investigated whether aptamer-based ...proteomic profiling could identify biomarkers associated with future development of type 2 diabetes (T2DM) beyond known risk factors. We identified dozens of markers with highly significant associations with future T2DM across two large longitudinal cohorts (n=2,839) followed for up to 16 years. We leveraged proteomic, metabolomic, genetic and clinical data from humans to nominate one specific candidate to test for potential causal relationships in model systems. Our studies identified functional effects of aminoacylase 1 (ACY1), a top protein association with future T2DM risk, on amino acid metabolism and insulin homeostasis in vitro and in vivo. Further, a loss-of-function variant associated with circulating levels of the biomarker WAP, Kazal, immunoglobulin, Kunitz and NTR domain-containing protein 2 (WFIKKN2) was in turn associated with fasting glucose, hemoglobin A1c and HOMA-IR measurements in humans. In addition to identifying novel disease markers and potential pathways in T2DM, we provide publicly available data to be leveraged for new insights about gene function and disease pathogenesis in the context of human metabolism. .
In this paper we describe a novel method for delivering a precise, known amount of electric charge to a micron-sized solid target. Aerosolised microparticles passed through a plasma discharge will ...acquire significant electric charge. The fluid stability under evaporative stress is a key aspect that is core to the research. Initially stable charged aerosols subject to evaporation (i.e. a continually changing radius) may encounter the Rayleigh stability limit. This limit arises from the electrostatic and surface tension forces and determines the maximum charge a stable droplet can retain, as a function of radius. We demonstrate that even if the droplet charge is initially much less than the Rayleigh limit, the stability limit will be encountered as the droplet evaporates. The instability emission mechanism is strongly linked to the final charge deposited on the target, providing a mechanism that can be used to ensure a predictable charge deposit on a known encapsulated microparticle.
•A mechanism to deliver a precise charge to an encapsulated micron-sized target.•Method relies on aerosolising the target, and passing the aerosol through a plasma.•Abundant free charge accumulates on aerosols from plasma interaction.•Evaporation of aerosols forces a series of Rayleigh instabilities.•Final charge on exposed target is consistently the final Raleigh instability limit.
Strong confinement of charges in few-electron systems such as in atoms, molecules, and quantum dots leads to a spectrum of discrete energy levels often shared by several degenerate states. Because ...the electronic structure is key to understanding their chemical properties, methods that probe these energy levels in situ are important. We show how electrostatic force detection using atomic force microscopy reveals the electronic structure of individual and coupled self-assembled quantum dots. An electron addition spectrum results from a change in cantilever resonance frequency and dissipation when an electron tunnels on/off a dot. The spectra show clear level degeneracies in isolated quantum dots, supported by the quantitative measurement of predicted temperature-dependent shifts of Coulomb blockade peaks. Scanning the surface shows that several quantum dots may reside on what topographically appears to be just one. Relative coupling strengths can be estimated from these images of grouped coupled dots.
Verifiable control of a swarmof unmanned aerial vehicles Bennet, D J; McInnes, C R
Proceedings of the Institution of Mechanical Engineers. Part G, Journal of aerospace engineering,
11/2009, Letnik:
223, Številka:
G7
Journal Article
Recenzirano
This article considers the distributed control of a swarm of unmanned aerial vehicles (UAVs) investigating autonomous pattern formation and reconfigurability. A behaviour-based approach to formation ...control is considered with a velocity field control algorithm developed through bifurcating potential fields. This new approach extends previous research into pattern formation using potential field theory by considering the use of bifurcation theory as a means of reconfiguring a swarm pattern through a free parameter change. The advantage of this kind of system is that it is extremely robust to individual failures, is scalable, and also flexible. The potential field consists of a steering and repulsive term with the bifurcation of the steering potential resulting in a change of the swarm pattern. The repulsive potential ensures collision avoidance and an equally spaced final formation. The stability of the system is demonstrated to ensure that desired behaviours always occur, assuming that at large separation distances the repulsive potential can be neglected through a scale separation that exists between the steering and repulsive potential. The control laws developed are applied to a formation of ten UAVs using a velocity field tracking approach, where it is shown numerically that desired patterns can be formed safely ensuring collision avoidance. PUBLICATION ABSTRACT
Lamina propria (LP) T cell populations in the normal human colon contain oligoclonal expansions, but their distribution has not been well studied. We analyzed T cell receptor (TCR) β-chain (Vβ) ...variable region expression in CD4+and CD8+peripheral blood T cells and LP T cells from separated colonic segments in 13 subjects. CD4+and CD8+Vβ subset expansions were found in the LP of most individuals, and remarkable differences in CD4+and CD8+TCR repertoires were apparent between colon and blood as well as between colon segments within each individual. The presence of such T cell expansions in colon therefore cannot be used to infer immunopathology. In addition, CD8+Vβ expansions seen in peripheral blood T cells, which have been previously shown to be clonal in origin, were also often expanded in LP T cells of the same subject. These results suggest that LP CD8+T cell stimulation may contribute to CD8+peripheral blood T cell expansions.
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