258 research outputs found
Detection of Mycoplasma pneumoniae in Simulated and True Clinical Throat Swab Specimens by Nanorod Array-Surface-Enhanced Raman Spectroscopy
The prokaryote Mycoplasma pneumoniae is a major cause of respiratory disease in humans, accounting for 20% of all community-acquired pneumonia and the leading cause of pneumonia in older children and young adults. The limitations of existing options for mycoplasma diagnosis highlight a critical need for a new detection platform with high sensitivity, specificity, and expediency. Here we evaluated silver nanorod arrays (NA) as a biosensing platform for detection and differentiation of M. pneumoniae in culture and in spiked and true clinical throat swab samples by surface-enhanced Raman spectroscopy (SERS). Three M. pneumoniae strains were reproducibly differentiated by NA-SERS with 95%–100% specificity and 94–100% sensitivity, and with a lower detection limit exceeding standard PCR. Analysis of throat swab samples spiked with M. pneumoniae yielded detection in a complex, clinically relevant background with >90% accuracy and high sensitivity. In addition, NA-SERS correctly classified with >97% accuracy, ten true clinical throat swab samples previously established by real-time PCR and culture to be positive or negative for M. pneumoniae. Our findings suggest that the unique biochemical specificity of Raman spectroscopy, combined with reproducible spectral enhancement by silver NA, holds great promise as a superior platform for rapid and sensitive detection and identification of M. pneumoniae, with potential for point-of-care application
Recommended from our members
Composition for personal growth : program design and evaluation.
<p>Two categories were used for cross-validation of the model, either type 1 or type 2. Clinical isolates were treated as an unknown class and cross-validated sensitivity, specificity, and class error were based on their classification prediction score with their respective reference strain control class. CV, cross-validated.</p><p>Cross-validated PLS-DA modeling statistics for the prediction performance for NA-SERS typing of individual type 1 and 2 <i>M</i>. <i>pneumoniae</i> clinical isolates.</p
Milestones in the Observations of Cosmic Magnetic Fields
Magnetic fields are observed everywhere in the universe. In this review, we
concentrate on the observational aspects of the magnetic fields of Galactic and
extragalactic objects. Readers can follow the milestones in the observations of
cosmic magnetic fields obtained from the most important tracers of magnetic
fields, namely, the star-light polarization, the Zeeman effect, the rotation
measures (RMs, hereafter) of extragalactic radio sources, the pulsar RMs, radio
polarization observations, as well as the newly implemented sub-mm and mm
polarization capabilities.
(Another long paragraph is omitted due to the limited space here)Comment: Invited Review (ChJA&A); 32 pages. Sorry if your significant
contributions in this area were not mentioned. Published pdf & ps files (with
high quality figures) now availble at http://www.chjaa.org/2002_2_4.ht
On the Origin of Cosmic Magnetic Fields
We review the literature concerning how the cosmic magnetic fields pervading
nearly all galaxies actually got started. some observational evidence involves
the chemical abundance of the light elements Be and B, while another one is
based on strong magnetic fields seen in high red shift galaxies. Seed fields,
whose strength is of order 10^{-20} gauss, easily sprung up in the era
preceding galaxy formation. Several mechanisms are proposed to amplify these
seed fields to microgauss strengths. The standard mechanism is the Alpha-Omega
dynamo theory. It has a major difficulty that makes unlikely to provide the
sole origin. The difficulty is rooted in the fact that the total flux is
constant. This implies that flux must be removed from the galactic discs. This
requires that the field and flux be separated, for otherwise interstellar mass
must be removed from the deep galactic gravitational and then their strength
increased by the alpha omega theory.Comment: 90 pages and 6 figures; accepted for publication in Reports of
Progress in Physics as an invited revie
Pulsar rotation measures and the large-scale structure of Galactic magnetic field
The large-scale magnetic field of our Galaxy can be probed in three
dimensions using Faraday rotation of pulsar signals. We report on the
determination of 223 rotation measures from polarization observations of
relatively distant southern pulsars made using the Parkes radio telescope.
Combined with previously published observations these data give clear evidence
for large-scale counterclockwise fields (viewed from the north Galactic pole)
in the spiral arms interior to the Sun and weaker evidence for a
counterclockwise field in the Perseus arm. However, in interarm regions,
including the Solar neighbourhood, we present evidence that suggests that
large-scale fields are clockwise. We propose that the large-scale Galactic
magnetic field has a bisymmetric structure with reversals on the boundaries of
the spiral arms. Streaming motions associated with spiral density waves can
directly generate such a structure from an initial inwardly directed radial
field. Large-scale fields increase toward the Galactic Center, with a mean
value of about 2~G in the Solar neighbourhood and 4~G at a
Galactocentric radius of 3 kpc.Comment: ApJ accepted. 16 pages, 14 figures, 2 tables, 223 pulsar RM
Counterclockwise magnetic fields in the Norma spiral arm
Pulsars provide unique probes of the large-scale interstellar magnetic field
in the Galactic disk. Up to now, the limited Galactic distribution of the known
pulsar population has restricted these investigations to within a few
kiloparsec of the Sun. The Parkes multibeam pulsar survey has discovered many
more-distant pulsars which enables us for the first time to explore the
magnetic field in most of the nearby half of the Galactic disk. Here we report
the detection of counterclockwise magnetic fields in the Norma spiral arm using
pulsar rotation measures. The fields are coherent in direction over a linear
scale of kpc along the arm and have a strength of G.
The magnetic field between the Carina-Sagittarius and Crux-Scutum arms is
confirmed to be coherent from l\sim45\degr to l\sim305\degr over a length
of kpc. These results strengthen arguments for a bisymmetric spiral
model for the field configuration in the Galactic disk.Comment: minor change
To what extent can behaviour change techniques be identified within an adaptable implementation package for primary care? A prospective directed content analysis
Interpreting evaluations of complex interventions can be difficult without sufficient description of key intervention content. We aimed to develop an implementation package for primary care which could be delivered using typically available resources and could be adapted to target determinants of behaviour for each of four quality indicators: diabetes control, blood pressure control, anticoagulation for atrial fibrillation and risky prescribing. We describe the development and prospective verification of behaviour change techniques (BCTs) embedded within the adaptable implementation packages
Cotranscriptional recruitment of the nuclear poly(A)-binding protein Pab2 to nascent transcripts and association with translating mRNPs
Synthesis of the pre-mRNA poly(A) tail in the nucleus has important consequences on the translational activity of the mature mRNA in the cytoplasm. In most eukaryotes, nuclear polyadenylation of pre-mRNAs is thought to require the nuclear poly(A)-binding protein (PABP2/PABPN1) for poly(A) tail synthesis and ultimate length control. As yet, however, the extent of the association between PABP2 and the exported mRNA remains poorly understood. Here, we used chromatin immunoprecipitation (ChIP) assays to show that the fission yeast ortholog of mammalian PABP2 (Pab2) is cotranscriptionally recruited to active genes. Notably, the association of Pab2 to genes precedes that of a typical 3′-processing/polyadenylation factor, suggesting that Pab2 recruitment during the transcription cycle precedes polyadenylation. The inclusion of an RNase step in our ChIP and immunoprecipitation assays suggests that Pab2 is cotranscriptionally recruited via nascent mRNA ribonucleoprotein (mRNPs). Tandem affinity purification coupled with mass spectrometry also revealed that Pab2 associates with several ribosomal proteins as well as general translation factors. Importantly, whereas previous results suggest that the nuclear poly(A)-binding protein is not present on cytoplasmic mRNAs, we show that fission yeast Pab2 is associated with polysomes. Our findings suggest that Pab2 is recruited to nascent mRNPs during transcription and remains associated with translated mRNPs after nuclear export
Socio-economic Aspects of Marine Bivalve Production
The aim of this book is to review and analyse the goods and services of bivalve shellfish. How
they are defined, what determines the ecological functions that are the basis for the goods
and services, what controversies in the use of goods and services exist, and what is needed for
sustainable exploitation of bivalves from the perspective of the various stakeholders. The book
is focused on the goods and services, and not on impacts of shellfish aquaculture on the
benthic environment, or on threats like biotoxins; neither is it a shellfish culture handbook
although it can be used in evaluating shellfish culture. The reviews and analysis are based on
case studies that exemplify the concept, and show the strengths and weaknesses of the
current applications. The multi-authored reviews cover ecological, economic and social aspects
of bivalve goods and services. The book provides new insights for scientists, students, shellfish
producers, policy advisors, nature conservationists and decision makers
- …