5,257 research outputs found
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Photoacoustic Imaging for Noninvasive Periodontal Probing Depth Measurements.
The periodontal probe is the gold standard tool for periodontal examinations, including probing depth measurements, but is limited by systematic and random errors. Here, we used photoacoustic ultrasound for high-spatial resolution imaging of probing depths. Specific contrast from dental pockets was achieved with food-grade cuttlefish ink as a contrast medium. Here, 39 porcine teeth (12 teeth with artificially deeper pockets) were treated with the contrast agent, and the probing depths were measured with novel photoacoustic imaging and a Williams periodontal probe. There were statistically significant differences between the 2 measurement approaches for distal, lingual, and buccal sites but not mesial. Bland-Altman analysis revealed that all bias values were < ±0.25 mm, and the coefficients of variation for 5 replicates were <11%. The photoacoustic imaging approach also offered 0.01-mm precision and could cover the entire pocket, as opposed to the probe-based approach, which is limited to only a few sites. This report is the first to use photoacoustic imaging for probing depth measurements with potential implications to the dental field, including tools for automated dental examinations or noninvasive examinations
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In vitro and in vivo modification of Neisseria gonorrhoeae lipooligosaccharide epitope structure by sialylation.
After growth of gonococci in the presence of cytidine monophospho-N-acetyl-neuraminic acid (CMP-NANA), their 4.5-kD lipooligosaccharide (LOS) component was increased by approximately 400 daltons, whereas the LOS of strains lacking the 4.5-kD component were unaffected. Expression of mAb-defined epitopes on the 4.5-kD component was decreased on LOS of strains grown in CMP-NANA, and treatment of the LOS with neuraminidase reversed this affect. Gonococci incubated with human PMNs also had decreased expression of the 4.5-kD+ epitopes. A detergent extract of gonococci incorporated radiolabeled NANA in the LOS, suggesting the presence of a sialyltransferase in gonococci. Exogenous sialyltransferases also could use LOS as an acceptor
MR Imaging Texture Analysis in the Abdomen and Pelvis
Texture analysis (TA) is a form of radiomics and refers to quantitative measurements of the
histogram, distribution and/or relationship of pixel intensities or gray scales within a region of
interest on an image. TA can be applied to MRI of the abdomen and pelvis, with the main
strength being quantitative analysis of pixel intensities and heterogeneity rather than
subjective/qualitative analysis. There are multiple limitations of MR texture analysis (MRTA)
including a dependency on image acquisition and reconstruction parameters, non-standardized
approaches without or with image filtration, diverse software methods and applications, and
statistical challenges relating numerous texture analysis results to clinical outcomes in
retrospective pilot studies with small sample sizes. Despite these limitations, there is a growing
body of literature supporting MRTA. In this review, the application of MRTA to the abdomen
and pelvis will be discussed, including tissue or tumor characterization and response evaluation
or prediction of outcomes in various tumors
The James Clerk Maxwell telescope dense gas survey of the Perseus molecular cloud
This is the final version of the article. Available from the publisher via the DOI in this record.We present the results of a large-scale survey of the very dense (n > 106 cm-3) gas in the Perseus molecular cloud using HCO+ and HCN (J = 4 → 3) transitions. We have used this emission to trace the structure and kinematics of gas found in pre- and protostellar cores, as well as in outflows. We compare the HCO+/HCN data, highlighting regions where there is a marked discrepancy in the spectra of the two emission lines. We use the HCO+ to identify positively protostellar outflows and their driving sources, and present a statistical analysis of the outflow properties that we derive from this tracer. We find that the relations we calculate between the HCO+ outflow driving force and the Menv and Lbol of the driving source are comparable to those obtained from similar outflow analyses using 12CO, indicating that the two molecules give reliable estimates of outflow properties. We also compare the HCO+ and the HCN in the outflows, and find that the HCN traces only the most energetic outflows, the majority of which are driven by young Class 0 sources. We analyse the abundances of HCN and HCO+ in the particular case of the IRAS 2A outflows, and find that the HCN is much more enhanced than the HCO+ in the outflow lobes. We suggest that this is indicative of shock enhancement of HCN along the length of the outflow; this process is not so evident for HCO+, which is largely confined to the outflow base. © 2014 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society.SLW-S and JH are funded by the Science and Technology Facilities
Council of the UK. The James Clerk Maxwell Telescope is
operated by the Joint Astronomy Centre on behalf of the Science
and Technology Facilities Council of the United Kingdom, the National
Research Council of Canada and (until 2013 March 31) the
Netherlands Organisation for Scientific Researc
The origin of life: chemical evolution of a metabolic system in a mineral honeycomb?
For the RNA-world hypothesis to be ecologically feasible, selection mechanisms acting on replicator communities need to be invoked and the corresponding scenarios of molecular evolution specified. Complementing our previous models of chemical evolution on mineral surfaces, in which selection was the consequence of the limited mobility of macromolecules attached to the surface, here we offer an alternative realization of prebiotic group-level selection: the physical encapsulation of local replicator communities into the pores of the mineral substrate. Based on cellular automaton simulations we argue that the effect of group selection in a mineral honeycomb could have been efficient enough to keep prebiotic ribozymes of different specificities and replication rates coexistent, and their metabolic cooperation protected from extensive molecular parasitism. We suggest that mutants of the mild parasites persistent in the metabolic system can acquire useful functions such as replicase activity or the production of membrane components, thus opening the way for the evolution of the first autonomous protocells on Earth
Neuropeptide S stimulates the hypothalamo-pituitary-adrenal axis and inhibits food intake.
Structural characterization and physical properties of P2O5-CaO-Na2O-TiO2 glasses by Fourier transform infrared, Raman and solid-state magic angle spinning nuclear magnetic resonance spectroscopies.
Phosphate-based glasses have been investigated for tissue engineering applications. This study details the properties and structural characterization of titanium ultra-phosphate glasses in the 55(P(2)O(5))-30(CaO)-(25-x)(Na(2)O)-x(TiO(2)) (0≤x≤5) system, which have been prepared via melt-quenching techniques. Structural characterization was achieved by a combination of X-ray diffraction (XRD), and solid-state nuclear magnetic resonance, Raman and Fourier transform infrared spectroscopies. Physical properties were also investigated using density, degradation and ion release studies; additionally, differential thermal analysis was used for thermal analysis of these glasses. The results show that with the addition of TiO(2) the density and glass transition temperature increased whereas the degradation and ion release properties are decreased. From XRD data, TiP(2)O(7) and CaP(2)O(6) were detected in 3 and 5 mol.% TiO(2)-containing glasses. Magic angle spinning nuclear magnetic resonance results confirmed that as TiO(2) is incorporated into the glass; the amount of Q(3) increases as the amount of Q(2) consequently decreases, indicating increasing polymerization of the phosphate network. Spectroscopy results also showed that the local structure of glasses changes with increasing TiO(2) content. As TiO(2) is incorporated into the glass, the phosphate connectivity increases, indicating that the addition of TiO(2) content correlates unequivocally with an increase in glass stability
Low levels of hepatitis C diagnosis and testing uptake among people who inject image and performance enhancing drugs in England and Wales, 2012-15
People injecting image and performance enhancing drugs (IPEDs) have traditionally not been perceived as being at high risk of hepatitis C virus (HCV) infection. However, recent studies indicate the HCV antibody (anti-HCV) prevalence in this group is 10-times that in the general population. HCV testing uptake and undiagnosed infections are examined using data from a voluntary unlinked-anonymous survey. Method People injecting IPEDs across England and Wales completed a short bio-behavioural survey (2012–15). Anti-HCV status and self-reports of HCV testing were used in the analysis. Results The participants median age was 31 years, 98% were men, 14% had also injected psychoactive drugs and the anti-HCV prevalence was 4.8% (N = 564). Among those who had never injected psychoactive drugs the anti-HCV prevalence was 1.4%; among those who had recently injected psychoactive drugs (preceding 12 months) prevalence was 39% and among those who had done this previously 14% (p < 0.001). Overall, 37% had been tested for HCV: among those who had recently injected psychoactive drugs 78% had been tested, as had 56% of those who had injected psychoactive drugs previously; 33% of those never injecting psychoactive drugs were tested (p < 0.001). Overall, 44% of those with anti-HCV were aware of this; however, only 14% of those who had never injected psychoactive drugs were aware. Conclusions One-in-twenty people who inject IPEDs have anti-HCV. HCV infections among those who had never injected psychoactive drugs were mostly undiagnosed, though this group had a lower prevalence. Targeted HCV testing interventions are also needed for those injecting IPEDs
Prevalence of, and risk factors for, HIV, hepatitis B and C infections among men who inject image and performance enhancing drugs: a cross-sectional study
Objective: To describe drug use, sexual risks and the prevalence of blood-borne viral infections among men who inject image and performance enhancing drugs (IPEDs).
Design: A voluntary unlinked-anonymous crosssectional biobehavioural survey.
Setting: 19 needle and syringe programmes across England and Wales.
Participants: 395 men who had injected IPEDs.
Results: Of the participants (median age 28 years), 36% had used IPEDs for <5 years. Anabolic steroids (86%), growth hormone (32%) and human chorionic gonadotropin (16%) were most frequently injected, with 88% injecting intramuscularly and 39% subcutaneously. Two-thirds also used IPEDs orally. Recent psychoactive drug use was common (46% cocaine, 12% amphetamine), 5% had ever injected a psychoactive drug and 9% had shared injecting equipment. ‘Viagra/Cialis’ was used by 7%, with 89% reporting anal/vaginal sex in the preceding year (20% had 5+ female-partners, 3% male-partners) and 13% always using condoms. Overall, 1.5% had HIV, 9% had antibodies to the hepatitis B core antigen (anti-HBc) and 5% to hepatitis C (anti-HCV). In multivariate analysis, having HIV was associated with: seeking advice from a sexual health clinic; having had an injection site abscess/wound; and having male partners. After excluding those reporting male partners or injecting psychoactive drugs, 0.8% had HIV, 8% anti-HBc and 5% anti-HCV. Only 23% reported uptake of the hepatitis B vaccine, and diagnostic testing uptake was poor (31% for HIV, 22% for hepatitis C).
Conclusions: Previous prevalence studies had not found HIV among IPED injectors. HIV prevalence in this, the largest study of blood-borne viruses among IPED injectors, was similar to that among injectors of psychoactive drugs. Findings indicate a need for targeted interventions
Helping in humans and other animals: a fruitful interdisciplinary dialogue.
Humans are arguably unique in the extent and scale of cooperation with unrelated individuals. While pairwise interactions among non-relatives occur in some non-human species, there is scant evidence of the large-scale, often unconditional prosociality that characterizes human social behaviour. Consequently, one may ask whether research on cooperation in humans can offer general insights to researchers working on similar questions in non-human species, and whether research on humans should be published in biology journals. We contend that the answer to both of these questions is yes. Most importantly, social behaviour in humans and other species operates under the same evolutionary framework. Moreover, we highlight how an open dialogue between different fields can inspire studies on humans and non-human species, leading to novel approaches and insights. Biology journals should encourage these discussions rather than drawing artificial boundaries between disciplines. Shared current and future challenges are to study helping in ecologically relevant contexts in order to correctly interpret how payoff matrices translate into inclusive fitness, and to integrate mechanisms into the hitherto largely functional theory. We can and should study human cooperation within a comparative framework in order to gain a full understanding of the evolution of helping
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