2,855 research outputs found
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Collagen scaffolds as a tool for understanding the biological effect of silicates
Dietary silicon is essential in the maintenance of bone and cartilage. However, the mechanism by which silicon, in the form of silicates, triggers a biological response has never been uncovered. Here we demonstrate the incorporation of orthosilicic acid (Si(OH)4), the form of silicon in the body, within collagen scaffolds for use as an in vitro platform to identify key genes affected by silicates. Ice-templated collagenâsilicate scaffolds, containing 0.21 wt% silicon, were validated by examining the mRNA levels for an array of genes in human osteoblasts and mesenchymal stromal cells (MSC) after 48 h in culture. Several novel genes, such as tumor necrosis factor alpha (TNF), were identified as having potential links to orthosilicic acid, verifying that collagenâsilicate scaffolds are a versatile platform for identifying novel mechanisms in which silicates regulate musculoskeletal tissue.The authors gratefully acknowledge the financial support of the Gates Cambridge Trust , ERC Advanced Grant 320598 3D-E and from the National Institute for Health Research. RJ is supported by the Medical Research Council (Grant number MC_US_A090_0008/Unit Programme number U1059).This is the final published version. It first appeared at http://www.sciencedirect.com/science/article/pii/S0167577X15300203#
X-ray fluorescence mapping of mercury on suspended mineral particles and diatoms in a contaminated freshwater system
Mercury (Hg) bioavailability and geochemical cycling is affected by its partitioning between the aqueous and particulate phases. We applied a synchrotron-based X-ray fluorescence (XRF) microprobe to visualize and quantify directly the spatial localization of Hg and its correlations with other elements of interest on suspended particles from a Hg-contaminated freshwater system. Up to 175 ÎŒg gâ»Âč Hg is found on suspended particles, but less than 0.01% is in the form of methylmercury. Mercury is heterogeneously distributed among phytoplankton (e.g., diatoms) and mineral particles that are rich in iron oxides and natural organic matter (NOM). The diatom-bound Hg is mostly found on outer surfaces of the cells, suggesting passive sorption of Hg on diatoms. Our results indicate that localized sorption of Hg onto suspended particles, including diatoms and NOM-coated oxide minerals, may play an important role in affecting the partitioning, reactivity, and biogeochemical cycling of Hg in natural aquatic environments
Chiropractic wellness on the web: the content and quality of information related to wellness and primary prevention on the Internet
<p>Abstract</p> <p>Background</p> <p>The Internet has become a common source of information for patients wishing to learn about health information. Previous studies found information related to back pain poor and often contradictory to current guidelines. Wellness has become a common topic in the field of chiropractic and accrediting agencies have standards on delivery of wellness-based content in college curricula as well as directives for clinical applications. The purpose of this study was to evaluate the quality of the information on the Internet using the terms "chiropractic wellness," or "wellness chiropractic".</p> <p>Methods</p> <p>Five commonly used search engines were selected and the first 10 sites found using the strategy above were evaluated by two raters. Demographic assessments of the sites were made along with whether they were Health on the Net Foundation (HON) certified, contained standard wellness content, mentioned any Healthy People Focus Areas, and other chiropractic topics. Kappa statistics compared inter-rater agreement.</p> <p>Results</p> <p>Potential patients appeared to be the audience 87% of the time and a private doctor of chiropractic appeared to be the typical site owner. The sites usually promoted the provider. No sites displayed HON certification logo nor did any appear to meet the HON certification criteria. Twenty-six sites (55%) promoted regular physical activity in some manner and 18 (38%) had information on health risks of tobacco. Four (9%) had mental health or stress-reduction content but none had information supportive of vaccination. Some had information contradictory to common public health measures.</p> <p>Conclusions</p> <p>Patients searching the Internet for chiropractic wellness information will often find useless information that will not help them maintain health or become well. Most simply market the chiropractic practice or allow for a patients to provide personal information in exchange for more 'wellness' information. More research should be done on how providers determine site content, pay any attention to the details on their sites, or agree with content as some appear to be prefabricated sites. Website content could be enhanced by sharing of information from reputable sources like US Centers for Disease Control, the National Institutes of Health and other authoritative sources. HON certification should also be sought.</p
Myopericarditis diagnosed by a 64-slice coronary CT angiography "triple rule out" protocol
We report a case of myopericarditis in a 30-year-old male complaining of shortness of breath. In an emergency department (ED) setting, the symptoms of myopericarditis may overlap with many disease entities and can be a challenging diagnosis to make. However, with the use of a 64-section coronary CT angiography in a âtriple rule outâ (TRO) protocol, we were able to detect a large pericardial effusion surrounding the heart and moderate global hypokinesis in the setting of normal-sized heart chambers and normal coronary arteries. We were further able to exclude pulmonary embolism and thoracic dissection. This is the first reported case of diagnosing myopericarditis using a TRO protocol. It demonstrates the usefulness of TRO in making an emergent diagnosis of myopericarditis while excluding other life-threatening diseases that can lead to earlier appropriate ED disposition and care
Borrelia recurrentis employs a novel multifunctional surface protein with anti-complement, anti-opsonic and invasive potential to escape innate immunity
Borrelia recurrentis, the etiologic agent of louse-borne relapsing fever in humans, has evolved strategies, including antigenic variation, to evade immune defence, thereby causing severe diseases with high mortality rates. Here we identify for the first time a multifunctional surface lipoprotein of B. recurrentis, termed HcpA, and demonstrate that it binds human complement regulators, Factor H, CFHR-1, and simultaneously, the host protease plasminogen. Cell surface bound factor H was found to retain its activity and to confer resistance to complement attack. Moreover, ectopic expression of HcpA in a B. burgdorferi B313 strain, deficient in Factor H binding proteins, protected the transformed spirochetes from complement-mediated killing. Furthermore, HcpA-bound plasminogen/plasmin endows B. recurrentis with the potential to resist opsonization and to degrade extracellular matrix components. Together, the present study underscores the high virulence potential of B. recurrentis. The elucidation of the molecular basis underlying the versatile strategies of B. recurrentis to escape innate immunity and to persist in human tissues, including the brain, may help to understand the pathological processes underlying louse-borne relapsing fever
Prevalence of under and over weight in children with neurodisability, using body composition measures
We aimed to compare rates of under and overweight in children with different neurodevelopmental disorders (NDD) by measuring weight, height/length, arm-to-leg bioelectrical impedance (BIA) and subscapular and triceps skinfolds in 146 children aged 4-16 years attending special schools. Z scores were calculated and skinfolds and lean mass Z scores were further adjusted for height. Underweight was found in 9% (14) children (body mass index (BMI)â<â2nd) but only 3% (4) had skinfolds <5th centile. Overweight was much commoner, with 41% (58) children having BMIâ>â95th and 20% (14) had skinfolds >95th centile. Children with cerebral palsy were very short with low BMI and lean mass, but only 8% (3) had skinfolds <5th centile. The children with Down syndrome were also very short and once adjusted for height, half had skinfolds >95th centile. We conclude that overweight and raised body fat is now common in children with NDD, even when the BMI is low
Static stretching of the hamstring muscle for injury prevention in football codes: a systematic review
Purpose: Hamstring injuries are common among football players. There is still disagreement regarding prevention. The aim of this review is to determine whether static stretching reduces hamstring injuries in football codes.
Methods: A systematic literature search was conducted on the online databases PubMed, PEDro, Cochrane, Web of Science, Bisp and Clinical Trial register. Study results were presented descriptively and the quality of the studies assessed were based on Cochraneâs ârisk of biasâ tool.
Results: The review identified 35 studies, including four analysis studies. These studies show deficiencies in the quality of study designs.
Conclusion: The study protocols are varied in terms of the length of intervention and follow-up. No RCT studies are available, however, RCT studies should be conducted in the near future
The Dawn of Open Access to Phylogenetic Data
The scientific enterprise depends critically on the preservation of and open
access to published data. This basic tenet applies acutely to phylogenies
(estimates of evolutionary relationships among species). Increasingly,
phylogenies are estimated from increasingly large, genome-scale datasets using
increasingly complex statistical methods that require increasing levels of
expertise and computational investment. Moreover, the resulting phylogenetic
data provide an explicit historical perspective that critically informs
research in a vast and growing number of scientific disciplines. One such use
is the study of changes in rates of lineage diversification (speciation -
extinction) through time. As part of a meta-analysis in this area, we sought to
collect phylogenetic data (comprising nucleotide sequence alignment and tree
files) from 217 studies published in 46 journals over a 13-year period. We
document our attempts to procure those data (from online archives and by direct
request to corresponding authors), and report results of analyses (using
Bayesian logistic regression) to assess the impact of various factors on the
success of our efforts. Overall, complete phylogenetic data for ~60% of these
studies are effectively lost to science. Our study indicates that phylogenetic
data are more likely to be deposited in online archives and/or shared upon
request when: (1) the publishing journal has a strong data-sharing policy; (2)
the publishing journal has a higher impact factor, and; (3) the data are
requested from faculty rather than students. Although the situation appears
dire, our analyses suggest that it is far from hopeless: recent initiatives by
the scientific community -- including policy changes by journals and funding
agencies -- are improving the state of affairs
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The convective storm initiation project
Copyright @ 2007 AMSThe Convective Storm Initiation Project (CSIP) is an international project to understand precisely where, when, and how convective clouds form and develop into showers in the mainly maritime environment of southern England. A major aim of CSIP is to compare the results of the very high resolution Met Office weather forecasting model with detailed observations of the early stages of convective clouds and to use the newly gained understanding to improve the predictions of the model. A large array of ground-based instruments plus two instrumented aircraft, from the U.K. National Centre for Atmospheric Science (NCAS) and the German Institute for Meteorology and Climate Research (IMK), Karlsruhe, were deployed in southern England, over an area centered on the meteorological radars at Chilbolton, during the summers of 2004 and 2005. In addition to a variety of ground-based remote-sensing instruments, numerous rawin-sondes were released at one- to two-hourly intervals from six closely spaced sites. The Met Office weather radar network and Meteosat satellite imagery were used to provide context for the observations made by the instruments deployed during CSIP. This article presents an overview of the CSIP field campaign and examples from CSIP of the types of convective initiation phenomena that are typical in the United Kingdom. It shows the way in which certain kinds of observational data are able to reveal these phenomena and gives an explanation of how the analyses of data from the field campaign will be used in the development of an improved very high resolution NWP model for operational use.This work is funded by the National Environment Research Council following an initial award from the HEFCE Joint Infrastructure Fund
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