1,765 research outputs found
Fabrication of an in-plane SU-8 cantilever with integrated strain gauge for wall shear stress measurements in fluid flows.
We present a cantilever fabricated from the polymer SU-8 for the measurement of wall shear stress in fluid flows. The pressure induced deflection of the cantilever, measured using a calibrated and integrated nichrome strain gauge, can be related to the wall shear stress on the surface. The initial degree of curvature of the cantilever can be controlled via the exposure dose, which allows a small positive deflection to be achieved, and so minimises the intrusion into the flow. Wind tunnel testing results show a sensitivity greater than 2.5 mV/Pa, with a shear stress of 0.38 Pa and excitation of 1 V
Strain-level resolution and pneumococcal carriage dynamics by single-molecule real-time (SMRT) sequencing of the plyNCR marker: a longitudinal study in Swiss infants
BACKGROUND
Pneumococcal carriage has often been studied from a serotype perspective; however, little is known about the strain-specific carriage and inter-strain interactions. Here, we examined the strain-level carriage and co-colonization dynamics of Streptococcus pneumoniae in a Swiss birth cohort by PacBio single-molecule real-time (SMRT) sequencing of the plyNCR marker.
METHODS
A total of 872 nasal swab (NS) samples were included from 47 healthy infants during the first year of life. Pneumococcal carriage was determined based on the quantitative real-time polymerase chain reaction (qPCR) targeting the lytA gene. The plyNCR marker was amplified from 214 samples having lytA-based carriage for pneumococcal strain resolution. Amplicons were sequenced using SMRT technology, and sequences were analyzed with the DADA2 pipeline. In addition, pneumococcal serotypes were determined using conventional, multiplex PCR (cPCR).
RESULTS
PCR-based plyNCR amplification demonstrated a 94.2% sensitivity and 100% specificity for Streptococcus pneumoniae if compared to lytA qPCR. The overall carriage prevalence was 63.8%, and pneumococcal co-colonization (≥ 2 plyNCR amplicon sequence variants (ASVs)) was detected in 38/213 (17.8%) sequenced samples with the relative proportion of the least abundant strain(s) ranging from 1.1 to 48.8% (median, 17.2%; IQR, 5.8-33.4%). The median age to first acquisition was 147 days, and having ≥ 2 siblings increased the risk of acquisition.
CONCLUSION
The plyNCR amplicon sequencing is species-specific and enables pneumococcal strain resolution. We therefore recommend its application for longitudinal strain-level carriage studies of Streptococcus pneumoniae. Video Abstract
Unit cell of graphene on Ru(0001): a 25 x 25 supercell with 1250 carbon atoms
The structure of a single layer of graphene on Ru(0001) has been studied
using surface x-ray diffraction. A surprising superstructure has been
determined, whereby 25 x 25 graphene unit cells lie on 23 x 23 unit cells of
Ru. Each supercell contains 2 x 2 crystallographically inequivalent subcells
caused by corrugation. Strong intensity oscillations in the superstructure rods
demonstrate that the Ru substrate is also significantly corrugated down to
several monolayers, and that the bonding between graphene and Ru is strong and
cannot be caused by van der Waals bonds. Charge transfer from the Ru substrate
to the graphene expands and weakens the C-C bonds, which helps accommodate the
in-plane tensile stress. The elucidation of this superstructure provides
important information in the potential application of graphene as a template
for nanocluster arrays.Comment: 9 pages, 3 figures, paper submitted to peer reviewed journa
Chlorantraniliprole (Rynaxypyr): A novel DuPontâ„¢ insecticide with low toxicity and low risk for honey bees (Apis mellifera) and bumble bees (Bombus terrestris) providing excellent tools for uses in integrated pest management
contribution to session IVTest methodology Background: The effects on bees of chlorantraniliprole (DPX-E2Y45, DuPontâ„¢ Rynaxypyr), a new anthranilic diamide insecticide with a novel and very specific mode of action activating insect ryanodine receptors were investigated.Results: Acute toxicity tests with chlorantraniliprole and the formulations, Coragen and Altacor, demonstrated low intrinsic toxicity to honey bees. Low risk for honey bees was demonstrated in semi-field tunnel tests with flowering Phacelia or wheat (with daily sprays of sugar solution to simulate honey dew) at application rates of Coragen of up to 60 g chlorantraniliprole/ha. Low potential of systemic exposure via pollen and nectar of honeybees to chlorantraniliprole was documented in a residue Phacelia tunnel trial with chlorantraniliprole applied to and mixed into bare soil. The impact of Altacor on bumble bees was studied in a greenhouse test in tomato at 40 g chlorantraniliprole/ha. Bumble bees directly over-sprayed during foraging activity with chlorantraniliprole or exposed to treated plants behaved as controls.
Conclusion: Chlorantraniliprole formulations provide excellent tools for integrated pest management (IPM) programmes to conserve pollinating honey bees and bumble bees.
Keywords: Chlorantraniliprole, Rynaxypyr®, insecticide, side-effects, honey bee, bumble bee, integrated pest management (IPM
Perceptions of the healthcare system among stakeholders
The U.S. healthcare system is rife with complexities and is consistently a source of political debate. One’s interaction with the system may directly impact the understanding of the system. The objective of this research is to examine the perceptions of the United States healthcare system from the viewpoint of healthcare providers, insurers, and consumers. Using a grounded theory approach, theoretical sampling was used to explore similarities and differences between the three groups of actors in the healthcare system. Data were collected through interviews with thirty-one participants using a semi-structured interview schedule. Themes of cost, access, and inefficiency emerged from the data. The theme of cost included the ability to pay, innovative care delivery, and relation to access. Access included the need for guidance, geographical proximity to healthcare, and socioeconomic status. The theme of inefficiency included how insurance dictates care, and the unwieldy system. Similarities among groups were the high cost of care, ability to pay, and complexity. Differences discovered were the insurers’ dual role as professional and consumer, providers’ informal access to care, and differing views on who is to blame for the high cost of healthcare. This research unveils perspectives of three stakeholders of actors in the healthcare system, providing a foundation for further research to better understand these perspectives in improving equity and access in healthcare.
Experience Framework
This article is associated with the Staff & Provider Engagement lens of The Beryl Institute Experience Framework (https://www.theberylinstitute.org/ExperienceFramework). Access other PXJ articles related to this lens. Access other resources related to this lens
Strain-level resolution and pneumococcal carriage dynamics by single-molecule real-time (SMRT) sequencing of the plyNCR marker: a longitudinal study in Swiss infants.
BACKGROUND
Pneumococcal carriage has often been studied from a serotype perspective; however, little is known about the strain-specific carriage and inter-strain interactions. Here, we examined the strain-level carriage and co-colonization dynamics of Streptococcus pneumoniae in a Swiss birth cohort by PacBio single-molecule real-time (SMRT) sequencing of the plyNCR marker.
METHODS
A total of 872 nasal swab (NS) samples were included from 47 healthy infants during the first year of life. Pneumococcal carriage was determined based on the quantitative real-time polymerase chain reaction (qPCR) targeting the lytA gene. The plyNCR marker was amplified from 214 samples having lytA-based carriage for pneumococcal strain resolution. Amplicons were sequenced using SMRT technology, and sequences were analyzed with the DADA2 pipeline. In addition, pneumococcal serotypes were determined using conventional, multiplex PCR (cPCR).
RESULTS
PCR-based plyNCR amplification demonstrated a 94.2% sensitivity and 100% specificity for Streptococcus pneumoniae if compared to lytA qPCR. The overall carriage prevalence was 63.8%, and pneumococcal co-colonization (≥ 2 plyNCR amplicon sequence variants (ASVs)) was detected in 38/213 (17.8%) sequenced samples with the relative proportion of the least abundant strain(s) ranging from 1.1 to 48.8% (median, 17.2%; IQR, 5.8-33.4%). The median age to first acquisition was 147 days, and having ≥ 2 siblings increased the risk of acquisition.
CONCLUSION
The plyNCR amplicon sequencing is species-specific and enables pneumococcal strain resolution. We therefore recommend its application for longitudinal strain-level carriage studies of Streptococcus pneumoniae. Video Abstract
Bupivacaine concentrations in the lumbar cerebrospinal fluid of patients during spinal anaesthesia
Background Data on bupivacaine concentrations in the cerebral spinal fluid (CSF) during spinal anaesthesia are scarce. The purpose of this study was to determine the concentration of bupivacaine in the lumbar CSF of patients with an adequate level of spinal anaesthesia after injection of plain bupivacaine 0.5%. Methods Sixty patients with an adequate level of spinal block after standardized administration of plain bupivacaine 20 mg in men and of 17.5 mg in women were studied. To measure the CSF bupivacaine concentration, we performed a second lumbar spinal puncture and obtained a CSF sample at a randomized time point 5-45 min after the bupivacaine injection. In addition, we calculated the half-life of bupivacaine in the CSF and tested the hypothesis that the level of spinal block is related to the lumbar CSF bupivacaine concentration. Results Men and women had CSF bupivacaine concentrations ranging from 95.4 to 773.0 µg ml−1 (median 242.4 µg ml−1) and from 25.9 to 781.0 µg ml−1 (median 187.6 µg ml−1), respectively. The large variability of bupivacaine concentrations obtained at similar times after subarachnoid administration made calculation of a meaningful half-life of bupivacaine in CSF impossible. There was no association between CSF bupivacaine concentration and spinal block level, and CSF bupivacaine concentrations for the same spinal block level differed between patients by six-fold. Conclusions There is a large variability of CSF bupivacaine concentrations in patients with an adequate level of spinal anaesthesi
Effect of conduction electron interactions on Anderson impurities
The effect of conduction electron interactions for an Anderson impurity is
investigated in one dimension using a scaling approach. The flow diagrams are
obtained by solving the renormalization group equations numerically. It is
found that the Anderson impurity case is different from its counterpart -- the
Kondo impurity case even in the local moment region. The Kondo temperature for
an Anderson impurity shows nonmonotonous behavior, increasing for weak
interactions but decreasing for strong interactions. The implication of the
study to other related impurity models is also discussed.Comment: 10 pages, revtex, 4 figures (the postscript file is included), to
appear in Phys. Rev. B (Rapid Commun.
Use of biomarkers or echocardiography in pulmonary embolism: the Swiss Venous Thromboembolism Registry
Background: Cardiac biomarkers and echocardiography for assessing right ventricular function are recommended to risk stratify patients with acute non-massive pulmonary embolism (PE), but it remains unclear if these tests are performed systematically in daily practice. Design and methods: Overall, 587 patients with acute non-massive PE from 18 hospitals were enrolled in the Swiss Venous Thromboembolism Registry (SWIVTER): 178 (30%) neither had a biomarker test nor an echocardiographic evaluation, 196 (34%) had a biomarker test only, 47 (8%) had an echocardiogram only and 166 (28%) had both tests. Results: Among the 409 (70%) patients with biomarkers or echocardiography, 210 (51%) had at least one positive test and 67 (16%) had positive biomarkers and right ventricular dysfunction. The ICU admission rates were 5.1% without vs. 5.6% with testing (P = 0.78), and thrombolysis or embolectomy were performed in 2.8% vs. 4.9%, respectively (P = 0.25). In multivariate analysis, syncope [odds ratio (OR): 3.49, 95% confidence interval (CI): 1.20-10.15; P = 0.022], tachycardia (OR: 2.31, 95% CI: 1.37-3.91; P = 0.002) and increasing age (OR: 1.02; 95% CI: 1.01-1.04; P < 0.001) were associated with testing of cardiac risk; outpatient status at the time of PE diagnosis (OR: 2.24, 95% CI: 1.49-3.36; P < 0.001), cancer (OR: 1.81, 95% CI: 1.17-2.79; P = 0.008) and provoked PE (OR: 1.58, 95% CI: 1.05-2.40; P = 0.029) were associated with its absence. Conclusions: Although elderly patients and those with clinically severe PE were more likely to receive a biomarker test or an echocardiogram, these tools were used in only two-thirds of the patients with acute non-massive PE and rarely in combinatio
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