207 research outputs found
Functional and Binding Characterizations of Urotensin II-Related Peptides in Human and Rat Urotensin II-Receptor Assay
Cardiovascular disease competes with breast cancer as the leading cause of death for older females diagnosed with breast cancer: a retrospective cohort study
Colorectal cancer screening using the faecal occult blood test (FOBt): a survey of GP attitudes and practices in the UK
<p>Abstract</p> <p>Background</p> <p>Colorectal cancer (CRC) is the third most common cancer in the UK. Five-year survival rates are less than 50%, largely because of late diagnosis. Screening using faecal occult blood tests (FOBt) can detect bowel cancer at an earlier stage than symptomatic presentation, and has the potential to significantly decrease colorectal cancer mortality. However, uptake of screening is currently low, despite the introduction of the NHS Bowel Cancer Screening Programme (NHSBCSP), and it has been suggested that GP recommendations of screening can improve patient compliance. GP recommendation of CRC screening is argued to be affected by attitudes towards it, along with perceptions of its efficacy.</p> <p>Methods</p> <p>This paper presents the findings of a cross-sectional postal survey of GPs in the UK which aimed to investigate GPs' attitudes in relation to colorectal cancer screening and the use of FOBt in routine practice. An 'attitude' score was calculated, and binary logistic regression used to evaluate the association of socio-demographic and general practice attributes with attitudes towards CRC screening and FOBt.</p> <p>Results</p> <p>Of 3,191 GPs surveyed, 960 returned usable responses (response rate 30.7%). Positive attitudes were associated with personal experience of CRC screening and Asian or Asian British ethnicity. GPs from practices located in more deprived locations were also more likely to have positive attitudes towards FOBt and its recommendation to patients.</p> <p>Conclusions</p> <p>The success of population-based screening for CRC will largely be determined by GP attitudes and support, particularly with regard to FOBt. Previous research has implied that South Asian GPs are more likely to have negative attitudes towards FOBt screening, however, our research suggests that this is not a group requiring targeted interventions to increase their support for the NHSBCSP. Of the available CRC screening tests, GPs perceived FOBt to be the most appropriate for population-based screening.</p
Photochemically reduced polyoxometalate assisted generation of silver and gold nanoparticles in composite films: a single step route
A simple method to embed noble metal (Ag, Au) nanoparticles in organicβinorganic nanocomposite films by single step method is described. This is accomplished by the assistance of Keggin ions present in the composite film. The photochemically reduced composite film has served both as a reducing agent and host for the metal nanoparticles in a single process. The embedded metal nanoparticles in composites film have been characterized by UVβVisible, TEM, EDAX, XPS techniques. Particles of less than 20 nm were readily embedded using the described approach, and monodisperse nanoparticles were obtained under optimized conditions. The fluorescence experiments showed that embedded Ag and Au nanoparticles are responsible for fluorescence emissions. The described method is facile and simple, and provides a simple potential route to fabricate self-standing noble metal embedded composite films
Decrease in Incidence of Colorectal Cancer Among IndividualsΒ 50 Years or Older After Recommendations forΒ Population-based Screening
BACKGROUND & AIMS: The incidence of colorectal cancer (CRC) in the United States is increasing among adults younger than 50 years, but incidence has decreased among older populations after population-based screening was recommended in the late 1980s. Blacks have higher incidence than whites. These patterns have prompted suggestions to lower the screening age for average-risk populations or in blacks. At the same time, there has been controversy over whether reductions in CRC incidence can be attributed to screening. We examined age-related and race-related differences in CRC incidence during a 40-year time period.
METHODS: We determined the age-standardized incidence of CRC from 1975 through 2013 by using the population-based Surveillance, Epidemiology, and End Results (SEER) program of cancer registries. We calculated incidence for 5-year age categories (20-24 years through 80-84 years and 85 years or older) for different time periods (1975-1979, 1980-1984, 1985-1989, 1990-1994, 1995-1999, 2000-2004, 2005-2009, and 2010-2013), tumor subsite (proximal colon, descending colon, and rectum), and stages at diagnosis (localized, regional, and distant). Analyses were stratified by race (white vs black).
RESULTS: There were 450,682 incident cases of CRC reported to the SEER registries during the entire period (1975-2013). Overall incidence was 75.5/100,000 white persons and 83.6/100,000 black persons. CRC incidence peaked during 1980 through 1989 and began to decrease in 1990. In whites and blacks, the decreases in incidence between the time periods of 1980-1984 and 2010-2013 were limited to the screening-age population (ages 50 years or older). Between these time periods, there was 40% decrease in incidence among whites compared with 26% decrease in incidence among blacks. Decreases in incidence were greater for cancers of the distal colon and rectum, and reductions in these cancers were greater among whites than blacks. CRC incidence among persons younger than 50 years decreased slightly between 1975-1979 and 1990. However, among persons 20-49 years old, CRC incidence increased from 8.3/100,000 persons in 1990-1994 to 11.4/100,000 persons in 2010-2013; incidence rates in younger adults were similar for whites and blacks.
CONCLUSIONS: On the basis of an analysis of the SEER cancer registries from 1975 through 2013, CRC incidence decreased only among individuals 50 years or older between the time periods of 1980-1984 and 2010-2013. Incidence increased modestly among individuals 20-49 years old between the time periods of 1990-1994 and 2010-2013. The decision of whether to recommend screening for younger populations requires a formal analysis of risks and benefits. Our observed trends provide compelling evidence that screening has had an important role in reducing CRC incidence
How to Join a Wave: Decision-Making Processes in Shimmering Behavior of Giant Honeybees (Apis dorsata)
Shimmering is a collective defence behaviour in Giant honeybees (Apis dorsata) whereby individual bees flip their abdomen upwards, producing Mexican wave-like patterns on the nest surface. Bucket bridging has been used to explain the spread of information in a chain of members including three testable concepts: first, linearity assumes that individual βagent beesβ that participate in the wave will be affected preferentially from the side of wave origin. The directed-trigger hypothesis addresses the coincidence of the individual property of trigger direction with the collective property of wave direction. Second, continuity describes the transfer of information without being stopped, delayed or re-routed. The active-neighbours hypothesis assumes coincidence between the direction of the majority of shimmering-active neighbours and the trigger direction of the agents. Third, the graduality hypothesis refers to the interaction between an agent and her active neighbours, assuming a proportional relationship in the strength of abdomen flipping of the agent and her previously active neighbours. Shimmering waves provoked by dummy wasps were recorded with high-resolution video cameras. Individual bees were identified by 3D-image analysis, and their strength of abdominal flipping was assessed by pixel-based luminance changes in sequential frames. For each agent, the directedness of wave propagation was based on wave direction, trigger direction, and the direction of the majority of shimmering-active neighbours. The data supported the bucket bridging hypothesis, but only for a small proportion of agents: linearity was confirmed for 2.5%, continuity for 11.3% and graduality for 0.4% of surface bees (but in 2.6% of those agents with high wave-strength levels). The complimentary part of 90% of surface bees did not conform to bucket bridging. This fuzziness is discussed in terms of self-organisation and evolutionary adaptedness in Giant honeybee colonies to respond to rapidly changing threats such as predatory wasps scanning in front of the nest
Microwave-Assisted Synthesis of Titania Nanocubes, Nanospheres and Nanorods for Photocatalytic Dye Degradation
TiO2nanostructures with fascinating morphologies like cubes, spheres, and rods were synthesized by a simple microwave irradiation technique. Tuning of different morphologies was achieved by changing the pH and the nature of the medium or the precipitating agent. As-synthesized titania nanostructures were characterized by X-ray diffraction (XRD), UVβvisible spectroscopy, infrared spectroscopy (IR), BET surface area, photoluminescence (PL), scanning electron microscopy (SEM) and transmission electron microscopy (TEM), and atomic force microscopy (AFM) techniques. Photocatalytic dye degradation studies were conducted using methylene blue under ultraviolet light irradiation. Dye degradation ability for nanocubes was found to be superior to the spheres and the rods and can be attributed to the observed high surface area of nanocubes. As-synthesized titania nanostructures have shown higher photocatalytic activity than the commercial photocatalyst Degussa P25 TiO2
Application of Magnetic Nanoparticles to Gene Delivery
Nanoparticle technology is being incorporated into many areas of molecular science and biomedicine. Because nanoparticles are small enough to enter almost all areas of the body, including the circulatory system and cells, they have been and continue to be exploited for basic biomedical research as well as clinical diagnostic and therapeutic applications. For example, nanoparticles hold great promise for enabling gene therapy to reach its full potential by facilitating targeted delivery of DNA into tissues and cells. Substantial progress has been made in binding DNA to nanoparticles and controlling the behavior of these complexes. In this article, we review research on binding DNAs to nanoparticles as well as our latest study on non-viral gene delivery using polyethylenimine-coated magnetic nanoparticles
Computing Highly Correlated Positions Using Mutual Information and Graph Theory for G Protein-Coupled Receptors
G protein-coupled receptors (GPCRs) are a superfamily of seven transmembrane-spanning proteins involved in a wide array of physiological functions and are the most common targets of pharmaceuticals. This study aims to identify a cohort or clique of positions that share high mutual information. Using a multiple sequence alignment of the transmembrane (TM) domains, we calculated the mutual information between all inter-TM pairs of aligned positions and ranked the pairs by mutual information. A mutual information graph was constructed with vertices that corresponded to TM positions and edges between vertices were drawn if the mutual information exceeded a threshold of statistical significance. Positions with high degree (i.e. had significant mutual information with a large number of other positions) were found to line a well defined inter-TM ligand binding cavity for class A as well as class C GPCRs. Although the natural ligands of class C receptors bind to their extracellular N-terminal domains, the possibility of modulating their activity through ligands that bind to their helical bundle has been reported. Such positions were not found for class B GPCRs, in agreement with the observation that there are not known ligands that bind within their TM helical bundle. All identified key positions formed a clique within the MI graph of interest. For a subset of class A receptors we also considered the alignment of a portion of the second extracellular loop, and found that the two positions adjacent to the conserved Cys that bridges the loop with the TM3 qualified as key positions. Our algorithm may be useful for localizing topologically conserved regions in other protein families
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