1,281 research outputs found
Human genetics and genomics a decade after the release of the draft sequence of the human genome
10.1186/1479-7364-5-6-577Human Genomics56577-62
Internal fracture caused by focusing of explosive waves
Internal fracture caused by focusing of explosive wave
Delayed presentation of symptomatic breast cancers in Hong Kong: Experience in a public cancer centre
Objective Delayed presentation is an important obstacle to improving cancer treatment outcomes. We aimed to study the magnitude of this problem in Hong Kong and the factors associated with delayed presentation of patients with symptomatic breast cancers. Design Retrospective study using self-administered questionnaires. Setting Clinical Oncology Department in a regional public hospital in Hong Kong. Patients A total of 158 Chinese women with breast cancer referred to our hospital between October 2006 and December 2007 consented to participate in this study. Among these, 59 (37%) patients were referred after having surgery in private sector. Results The mean total delay (from first symptom to treatment) was 22 weeks. The mean patient delay (from first symptom to first consultation) was 13 weeks, constituting the largest component (60%) of the total delay. After symptom onset, the delay exceeded 12 weeks for consulting a doctor in 29%, and for receipt of treatment in 52% of them. Low family income (<HK$5000 per month; P<0.001) and surgery in public hospitals (P=0.013) were both independent predictors of patient delay. Surgery in public hospitals (P=0.006) and low family income (P=0.005) were the only predictors of doctor/system delay and total delay, respectively. Conclusions Delayed presentation and treatment of symptomatic breast cancer remains an important issue in Hong Kong. Apart from socio-economic factors, limited access to public medical care was likely an important contributing factor in delays related to patients as well as to doctor/system.published_or_final_versio
Relativistic effects and two-body currents in using out-of-plane detection
Measurements of the reaction were performed
using an 800-MeV polarized electron beam at the MIT-Bates Linear Accelerator
and with the out-of-plane magnetic spectrometers (OOPS). The
longitudinal-transverse, and , and the
transverse-transverse, , interference responses at a missing momentum
of 210 MeV/c were simultaneously extracted in the dip region at Q=0.15
(GeV/c). On comparison to models of deuteron electrodisintegration, the
data clearly reveal strong effects of relativity and final-state interactions,
and the importance of the two-body meson-exchange currents and isobar
configurations. We demonstrate that these effects can be disentangled and
studied by extracting the interference response functions using the novel
out-of-plane technique.Comment: 4 pages, 4 figures, and submitted to PRL for publicatio
Macroscopic transport by synthetic molecular machines
Nature uses molecular motors and machines in virtually every significant biological process, but demonstrating that simpler artificial structures operating through the same gross mechanisms can be interfaced with—and perform physical tasks in—the macroscopic world represents a significant hurdle for molecular nanotechnology. Here we describe a wholly synthetic molecular system that converts an external energy source (light) into biased brownian motion to transport a macroscopic cargo and do measurable work. The millimetre-scale directional transport of a liquid on a surface is achieved by using the biased brownian motion of stimuli-responsive rotaxanes (‘molecular shuttles’) to expose or conceal fluoroalkane residues and thereby modify surface tension. The collective operation of a monolayer of the molecular shuttles is sufficient to power the movement of a microlitre droplet of diiodomethane up a twelve-degree incline.
Measurement of the Transverse-Longitudinal Cross Sections in the p (e,e'p)pi0 Reaction in the Delta Region
Accurate measurements of the p(e,e?p)pi0 reaction were performed at
Q^2=0.127(GeV/c)^2 in the Delta resonance energy region. The experiments at the
MIT-Bates Linear Accelerator used an 820 MeV polarized electron beam with the
out of plane magnetic spectrometer system (OOPS). In this paper we report the
first simultaneous determination of both the TL and TL? (``fifth" or polarized)
cross sections at low Q^{2} where the pion cloud contribution dominates the
quadrupole amplitudes (E2 and C2). The real and imaginary parts of the
transverse-longitudinal cross section provide both a sensitive determination of
the Coulomb quadrupole amplitude and a test of reaction calculations.
Comparisons with model calculations are presented. The empirical MAID
calculation gives the best overall agreement with this accurate data. The
parameters of this model for the values of the resonant multipoles are
|M_{1+}(I=3/2)|= (40.9 \pm 0.3)10^{-3}/m_pi, CMR= C2/M1= -6.5 \pm 0.3%,
EMR=E2/M1=-2.2 \pm 0.9%, where the errors are due to the experimental
uncertainties.Comment: 10 pages, 3 figures, minor corrections and addition
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