808 research outputs found
Low energy proton-proton scattering in effective field theory
Low energy proton-proton scattering is studied in pionless effective field
theory. Employing the dimensional regularization and MS-bar and power
divergence subtraction schemes for loop calculation, we calculate the
scattering amplitude in 1S0 channel up to next-to-next-to leading order and fix
low-energy constants that appear in the amplitude by effective range
parameters. We study regularization scheme and scale dependence in separation
of Coulomb interaction from the scattering length and effective range for the
S-wave proton-proton scattering.Comment: 23 pages, 6 eps figures, revised considerably, accepted for
publication in Phys. Rev.
Reconstituting ring-rafts in bud-mimicking topography of model membranes.
During vesicular trafficking and release of enveloped viruses, the budding and fission processes dynamically remodel the donor cell membrane in a protein- or a lipid-mediated manner. In all cases, in addition to the generation or relief of the curvature stress, the buds recruit specific lipids and proteins from the donor membrane through restricted diffusion for the development of a ring-type raft domain of closed topology. Here, by reconstituting the bud topography in a model membrane, we demonstrate the preferential localization of cholesterol- and sphingomyelin-enriched microdomains in the collar band of the bud-neck interfaced with the donor membrane. The geometrical approach to the recapitulation of the dynamic membrane reorganization, resulting from the local radii of curvatures from nanometre-to-micrometre scales, offers important clues for understanding the active roles of the bud topography in the sorting and migration machinery of key signalling proteins involved in membrane budding
Sex differences in atheroma burden and endothelial function in patients with early coronary atherosclerosis
Aims Women and men have different clinical presentations and outcomes in coronary artery disease (CAD). We tested the hypothesis that sex differences may influence coronary atherosclerotic burden and coronary endothelial function before development of obstructive CAD. Methods and results A total of 142 patients (53 men, 89 women; mean ± SD age, 49.3 ± 11.7 years) with early CAD simultaneously underwent intravascular ultrasonography and coronary endothelial function assessment. Atheroma burden in the left main and proximal left anterior descending (LAD) arteries was significantly greater in men than women (median, 23.0% vs. 14.1%, P = 0.002; median, 40.1% vs. 29.3%, P = 0.001, respectively). Atheroma eccentricity in the proximal LAD artery was significantly higher in men than women (median, 0.89 vs. 0.80, P = 0.04). The length of the coronary segments with endothelial dysfunction was significantly longer in men than women (median, 39.2 vs. 11.1 mm, P = 0.002). In contrast, maximal coronary flow reserve was significantly lower in women than men (2.80 vs. 3.30, P < 0.001). Sex was an independent predictor of atheroma burden in the left main and proximal LAD arteries (both P < 0.05) by multivariate analysis. Conclusion Men have greater atheroma burden, more eccentric atheroma, and more diffuse epicardial endothelial dysfunction than women. These results suggest that men have more severe structural and functional abnormalities in epicardial coronary arteries than women, even in patients with early atherosclerosis, which may result in the higher incidence rates of CAD and ST-segment myocardial infarction in men than wome
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Synthesis of Prussian blue-embedded porous polymer for detection and removal of Cs ions
A Prussian blue (PB)-embedded coordination polymer (COP) was prepd. by simple incorporation of PB into a COP composed of 1,1,2,2-tetrakis(4-carboxyphenyl)ethane and the Zn ion during the synthesis of COP. The PB-COP was prepd. as micro-sized particles with green emission (490 nm) from the strongly fluorescent tetraphenylethene group in the solid state through aggregation-induced emission. The PB-COP showed particle shape with sizes ranging from 1 to 6 μm. As the PB in PB-COP efficiently adsorbed Cs ions, the microstructure of PB-COP was degraded to smaller particles, along with a concomitant decrease in the green fluorescence of the PB-COP. Such a decrease in the green emission of PB-COP was used as a signal for the presence of Cs ions, in which the limit of detection for Cs ions was found to be 73.8 ppb. The hybridized material of the PB-COP can be used as both an efficient adsorbent and a sensor for Cs ions, achieving simultaneous removal and detection
New SX Phoenicis Stars in the Globular Cluster M53
Through time-series CCD photometry of the metal-poor globular cluster M53, we
have discovered eight new SX Phoenicis type stars (labeled from SXP1 to SXP8).
All the new SX Phoenicis stars are located in the blue straggler star region of
a color-magnitude diagram of M53. One of these stars (SXP2) is found to have
very closely separated pulsation frequencies: where
and are primary and secondary frequencies. This may be due to excitation
of non-radial modes. Six of these SX Phoenicis stars are considered to be
pulsating in the fundamental mode. They show a tight linear correlation between
the period and luminosity. We derive a period - luminosity relation for the
fundamental mode for the period range of :
with an rms scatter of 0.038,
corresponding to for an adopted distance modulus
of (Harris 1996).Comment: 31 pages with 7 figures, accepted by the Astronomical Journal
(scheduled June 2003
HEAT TRANSFER IN WAVY DUCT WITH DIFFERENT CORRUGATION ANGLE
ABSTRACT The present study investigates the effects of duct corrugation angle and flow velocity on the convective heat/mass transfer characteristics in wavy ducts applied in a primary surface heat exchanger. Local heat/mass transfer coefficients on the corrugated duct sidewall are determined using a naphthalene sublimation technique. The flow visualization technique is used to understand the overall flow structures inside the duct. The corrugation angles of the wavy ducts are 145º and 130º, and the duct aspect ratio is fixed at 7.3. The Reynolds numbers, based on the duct hydraulic diameter, vary from 1,000 to 5,000. The results show that secondary vortex flow cells, called TaylorGörtler vortices, exist periodically in the wavy duct. Therefore, non-uniform distributions of the heat/mass transfer coefficients are obtained on the duct walls. On the pressure-side wall, high heat/mass transfer cell-shaped regions appear due to the secondary vortex flows for both corrugation angles. On the suction-side wall, the heat transfer coefficients are lower than those on the pressure-side wall. The wavy duct with the corrugation angle of 130º has the stronger strength of the secondary vortex cells resulting in higher heat/mass transfer rates on the duct wall because the sharp turn enhances the development of the secondary flow cells
Dependence of reaction center-type energy-dependent quenching on photosystem II antenna size
AbstractThe effects of photosystem II antenna size on reaction center-type energy-dependent quenching (qE) were examined in rice plants grown under two different light intensities using both wild type and qE-less (OsPsbS knockout) mutant plants. Reaction center-type qE was detected by measuring non-photochemical quenching at 50 μmol photons m−2 s−1 white light intensity. We observed that in low light-grown rice plants, reaction center-type qE was higher than in high light-grown plants, and the amount of reaction center-type qE did not depend on zeaxanthin accumulation. This was confirmed in Arabidopsis npq1–2 mutant plants that lack zeaxanthin due to a mutation in the violaxanthin de-epoxidase enzyme. Although the electron transport rate measured at a light intensity of 50 μmol photons m−2 s−1 was the same in high light- and low light-grown wild type and mutant plants lacking PsbS protein, the generation of energy-dependent quenching was completely impaired only in mutant plants. Analyses of the pigment content, Lhcb proteins and D1 protein of PSII showed that the antenna size was larger in low light-grown plants, and this correlated with the amount of reaction center-type qE. Our results mark the first time that the reaction center-type qE has been shown to depend on photosystem II antenna size and, although it depends on the existence of PsbS protein, the extent of reaction center-type qE does not correlate with the transcript levels of PsbS protein. The presence of reaction center-type energy-dependent quenching, in addition to antenna-type quenching, in higher plants for dissipation of excess light energy demonstrates the complexity and flexibility of the photosynthetic apparatus of higher plants to respond to different environmental conditions
Effects of Gyejibongnyeong-hwan on dysmenorrhea caused by blood stagnation: study protocol for a randomized controlled trial
<p>Abstract</p> <p>Background</p> <p>Gyejibongnyeong-hwan (GJBNH) is one of the most popular Korean medicine formulas for menstrual pain of dysmenorrhea. The concept of blood stagnation in Korean medicine is considered the main factor of causing abdominal pain, or cramps, during menstrual periods. To treat the symptoms, GJBNH is used to fluidify the stagnated blood and induce the blood flow to be smooth, reducing pain as the result. The purpose of this trial is to identify the efficacy of GJBNH in dysmenorrhea caused by blood stagnation.</p> <p>Methods</p> <p>This study is a multi-centre, randomised, double-blind, controlled trial with two parallel arms: the group taking GJBNH and the group taking placebo. 100 patients (women from age 18 to 35) will be enrolled to the trial. Through randomization 50 patients will be in experiment arm, and the other 50 patients will be in control arm. At the second visit (baseline), all participants who were already screened that they fulfil both the inclusion and the exclusion criteria will be randomised into two groups. Each group will take the intervention three times per day during two menstrual cycles. After the treatment for two cycles, each patient will be followed up during their 3<sup>rd</sup>, 4<sup>th </sup>and 5<sup>th </sup>menstrual cycles. From the screening (Visit 1) through the second follow-up (Visit 6) the entire process will take 25 weeks.</p> <p>Discussion</p> <p>This trial will provide evidence for the effectiveness of GJBNH in treating periodical pain due to dysmenorrhea that is caused by blood stagnation. The primary outcome between the two groups will be measured by changes in the Visual Analogue Score (VAS) of pain. The secondary outcome will be measured by the Blood Stagnation Scale, the Short-form McGill questionnaire and the COX menstrual symptom scale. Analysis of covariance (ANCOVA) and repeated measured ANOVA will be used to analyze the data analysis.</p> <p>Trial registration</p> <p>Current Controlled Trials: <a href="http://www.controlled-trials.com/ISRCTN30426947">ISRCTN30426947</a></p
Comparison of The Genome Profiles Between Head and Body Lice
The body louse (Pediculus humanus humanus) is known to have diverged from the head louse (P. humanus capitis) but genomic differences between these two subspecies still remain unexplored. To compare genomic profiles between head and body lice, whole genome sequences of head lice were determined by next generation sequencing methods based on both Illumina Genome analyzer and Roche GS FLX pyrosequencing and compared with the reference genome sequences of the body louse. Total consensuses generated by mapping to the body louse genome in conjunction with de novo assembly of head louse genome sequences revealed a head louse genome size of 110 Mbp with a 96% coverage of the body louse genome sequences. A total of 12,651 genes were predicted from the head louse genome sequences although more precise assembly and functional annotation of the genome is required for a more accurate gene count. Among the 873 genes that were putatively specific to the head louse, 15 genes were confirmed to be transcribed in both head and body lice, suggesting the previously estimated gene number of the body louse was likely underestimated. The single nucleotide polymorphism analysis showed that the nucleotide diversity of genome between head and body lice was 2.2%, which was larger than that of the transcriptome between head and body lice. An endosymbiont genome analysis showed that the composition of endosymbionts in head lice was similar to that of body lice and Candidatus Riesia pediculicola was the primary endosymbiont in both head and body lice
Correction to. Magnetic resonance imaging for clinical management of rectal cancer: Updated recommendations from the 2016 European Society of Gastrointestinal and Abdominal Radiology (ESGAR) consensus meeting
Objectives: To update the 2012 ESGAR consensus guidelines on the acquisition, interpretation and reporting of magnetic resonance imaging (MRI) for clinical staging and restaging of rectal cancer. Methods Fourteen abdominal imaging experts from the European Society of Gastrointestinal and Abdominal Radiology (ESGAR) participated in a consensus meeting, organised according to an adaptation of the RAND-UCLA Appropriateness Method. Two independent (non-voting) Chairs facilitated the meeting. 246 items were scored (comprising 229 items from the previous 2012 consensus and 17 additional items) and classified as ‘appropriate’ or ‘inappropriate’ (defined by ≥ 80 % consensus) or uncertain (defined by < 80 % consensus).
Results: Consensus was reached for 226 (92 %) of items. From these recommendations regarding hardware, patient preparation, imaging sequences and acquisition, criteria for MR imaging evaluation and reporting structure were constructed. The main additions to the 2012 consensus include recommendations regarding use of diffusion-weighted imaging, criteria for nodal staging and a recommended structured report template.
Conclusions: These updated expert consensus recommendations should be used as clinical guidelines for primary staging and restaging of rectal cancer using MRI
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