1,760 research outputs found
What do -ray bursts look like?
There have been great and rapid progresses in the field of -ray
bursts (denoted as GRBs) since BeppoSAX and other telescopes discovered their
afterglows in 1997. Here, we will first give a brief review on the
observational facts of GRBs and direct understanding from these facts, which
lead to the standard fireball model. The dynamical evolution of the fireball is
discussed, especially a generic model is proposed to describe the whole
dynamical evolution of GRB remnant from highly radiative to adiabatic, and from
ultra-relativistic to non-relativistic phase. Then, Various deviations from the
standard model are discussed to give new information about GRBs and their
environment. In order to relax the energy crisis, the beaming effects and their
possible observational evidences are also discussed in GRB's radiations.Comment: 10 pages, Latex. Invited talk at the Pacific Rim Conference on
Stellar Astrophysics, Hong Kong, China, Aug. 199
Effects of the Multidisciplinary Risk Assessment and Management Program for Patients with Diabetes Mellitus (RAMP-DM) on biomedical outcomes, observed cardiovascular events and cardiovascular risks in primary care: a longitudinal comparative study
Background To assess whether the Multidisciplinary Risk Assessment and Management Program for Patients with Diabetes Mellitus (RAMP-DM) led to improvements in biomedical outcomes, observed cardiovascular events and predicted cardiovascular risks after 12-month intervention in the primary care setting. Methods A random sample of 1,248 people with diabetes enrolled to RAMP-DM for at least 12-months was selected and 1,248 people with diabetes under the usual primary care were matched by age, sex, and HbA1c level at baseline as the usual care group. Biomedical and cardiovascular outcomes were measured at baseline and at 12-month after the enrollment. Difference-in-differences approach was employed to measure the effect of RAMP-DM on the changes in biomedical outcomes, proportion of subjects reaching treatment targets, observed and predicted cardiovascular risks. Results Compared to the usual care group, RAMP-DM group had lower cardiovascular events incidence (1.21% vs 2.89%, P=0.003), and net decrease in HbA1c (-0.20%, P<0.01), SBP (-3.62 mmHg, P<0.01) and 10-year cardiovascular disease (CVD) risks (total CVD risk, -2.06%, P<0.01; coronary heart disease (CHD) risk, -1.43%, P<0.01; stroke risk, ?0.71%, P<0.01). The RAMP-DM subjects witnessed significant rises in the proportion of reaching treatment targets of HbA1c, and SBP/DBP. After adjusting for confounding variables, the significance remained for HbA1c, predicted CHD and stroke risks. Conclusions The RAMP-DM resulted in greater improvements in HbA1c and reduction in observed and predicted cardiovascular risks at 12-months follow-up, which indicated a risk-stratification multidisciplinary intervention was an effective strategy for managing Chinese people with diabetes in the primary care setting. Trial registryClinicalTrials.gov, NCT02034695published_or_final_versio
Effectiveness of the multidisciplinary Risk Assessment and Management Program for Patients with Diabetes Mellitus (RAMP-DM) for diabetic microvascular complications: A population-based cohort study
Aim: To evaluate the effectiveness of the multidisciplinary Risk Assessment and Management Program for Patients with Diabetes Mellitus (RAMP-DM) in reducing the risks of microvascular complications. Methods: This prospective cohort study was conducted with 29,670 propensity-score-matched RAMP-DM participants and diabetes patients under the usual primary care (14,835 in each group). Study endpoints were the first occurrence of any diabetic microvascular complications, non-proliferative diabetic retinopathy/preproliferative diabetic retinopathy (NPDR/prePDR), sight-threatening diabetic retinopathy (STDR) or blindness, nephropathy, end-stage renal disease (ESRD), neuropathy and lower-limb ulcers or amputation. Log-rank tests and multivariable Cox proportional-hazards regressions were employed to estimate between-group differences in incidences of study endpoints. Results: After a median follow-up of 36 months with>41,000 person-years in each group, RAMP-DM participants had a lower incidence of microvascular complications (760 vs 935; adjusted hazard ratio [HR]: 0.73; 95% confidence interval [CI]: 0.66-0.81; P<0.001) and lower incidences of all specific microvascular complications except neuropathy (adjusted HR: 0.94; 95% CI: 0.61-1.45; P=0.778). Adjusted HRs for the RAMP-DM vs control group for ESRD, STDR or blindness, and lower-limb ulcers or amputation were 0.40 (95% CI: 0.24-0.69; P<0.001), 0.55 (95% CI: 0.39-0.78; P=0.001) and 0.49 (95% CI: 0.30-0.80; P=0.005), respectively. Conclusion: The RAMP-DM intervention was associated with lower incidences of all microvascular complications except neuropathy over a 3-year follow-up. These encouraging results constitute evidence that structured risk assessment and risk-stratified management provided by a multidisciplinary team is effective for reducing microvascular complications in diabetes patients.postprin
Long-term effects of the multidisciplinary risk assessment and management program for patients with diabetes mellitus (RAMP-DM): a population-based cohort study
Background: Studies on the long-term effectiveness of multidisciplinary risk-stratification based management in Chinese population were rare. This study aimed to evaluate the effectiveness of a multidisciplinary risk assessment and management program for patients with diabetes mellitus (RAMP-DM) in reducing the risks of cardiovascular complications and all-cause mortality. Methods: A prospective cohort study was conducted in 18,188 propensity score matched RAMP-DM participants and subjects with diabetes under usual primary care (9,094 subjects in each group). The study endpoints were the first occurrence of coronary heart disease (CHD), stroke, heart failure (HF), total cardiovascular disease (CVD) and all-cause mortality. We constructed multivariable Cox proportional hazard regressions to estimate the association between the RAMP-DM intervention and the first occurrence of study endpoints. Results: The median follow-up period was 36 months. Three hundred and ninety-nine CVD events occurred in the RAMP-DM group, as compared with 608 in the control group [adjusted hazard ratio, 0.629; 95 % confidence interval (CI) 0.554–0.715; P < 0.001]. The total number of all-cause deaths in RAMP-DM group was less than half that of control group (202 vs 552, adjusted hazard ratio, 0.363; 95 % CI, 0.308–0.428; P < 0.001). The adjusted hazard ratios of the RAMP-DM group for CHD, stroke, and HF were 0.570 (95 % CI, 0.470–0.691; P < 0.001), 0.652 (95 % CI, 0.546–0.780; P < 0.001), and 0.598 (95 %CI, 0.446–0.802; P = 0.001), respectively. Conclusions: The RAMP-DM intervention was associated with lower incidences of individual and total cardiovascular complications, as well as all-cause mortality over 3 years follow-up. The encouraging results provided evidence to support that the structured risk-stratification management leading by a multidisciplinary clinical team was an effective approach to reduce future cardiovascular complications in people with diabetes.published_or_final_versio
Effects of Patient Empowerment Programme (PEP) on Clinical Outcomes and Health Service Utilization in Type 2 Diabetes Mellitus in Primary Care: An Observational Matched Cohort Study
Background: To evaluate the effects of a large population-based patient empowerment programme (PEP) on clinical outcomes and health service utilization rates in type 2 diabetes mellitus (T2DM) patients in the primary care setting. Research Design and Subjects: A stratified random sample of 1,141 patients with T2DM enrolled to PEP between March and September 2010 were selected from general outpatient clinics (GOPC) across Hong Kong and compared with an equal number of T2DM patients who had not participated in the PEP (non-PEP group) matched by age, sex and HbA1C level group. Measures: Clinical outcomes of HbA1c, SBP, DBP and LDL-C levels, and health service utilization rates including numbers of visits to GOPC, specialist outpatient clinics (SOPC), emergency department (ED) and inpatient admissions, were measured at baseline and at 12-month post-recruitment. The effects of PEP on clinical outcomes and health service utilization rates were assessed by the difference-in-difference estimation, using the generalized estimating equation models. Results: Compared with non-PEP group, PEP group achieved additional improvements in clinical outcomes over the 12-month period. A significantly greater percentage of patients in the PEP group attained HbA1C≤7% or LDL-C≤2.6 mmol/L at 12-month follow-up compared with the non-PEP group. PEP group had a mean 0.813 fewer GOPC visits in comparison with the non-PEP group. Conclusions: PEP was effective in improving the clinical outcomes and reduced the general outpatient clinic utilization rate over a 12-month period. Empowering T2DM patients on self-management of their disease can enhance the quality of diabetes care in primary care.published_or_final_versio
In situ revelation of a zinc-blende InN wetting layer during Stranski-Krastanov growth on GaN(0001) by molecular-beam epitaxy
Indium nitride (InN) exists in two different structural phases, the equilibrium wurtzite (w) and the metastable zinc-blende (zb) phases. It is of scientific interest and practical relevance to examine the crystal structure of the epifilms during growth. In this paper, we use Patterson function inversion of low-energy electron diffraction I-V curves to reveal the preferential formation of zinc-blende InN wetting layer during the Stranski-Krastanov growth on GaN(0001). For three-dimensional islands nucleated afterwards on top of the wetting layer and for thick InN films, the equilibrium wurtzite structure is observed instead. This in situ revelation of the InN lattice structure is confirmed by ex situ transmission electron microscopy studies. Finally, the formation of zb-InN layer on w-GaN is explained in terms of the strain in the system. © 2005 The American Physical Society.published_or_final_versio
Quality Grade Evaluation of Niuhuang Qingwei Pills Based on UPLC and TCM Reference Drug—A Novel Principle of Analysis of Multiple Components in Ready-Made Chinese Herbal Medicine
Ready-made Chinese herbal medicine (RMCHM) is one of the most common types of synergistic herbal medicine used worldwide. It is based on composite herbal formulae (CHF), which makes quality control of this kind of traditional Chinese medicine (TCM) difficult, let alone distinguishing the good from the bad. Taking Niuhuang Qingwei Pills (NHQWP) as an example, this study reported the development of a novel principle of analysis of multiple components in RMCHM. Experimental procedures involved the selection of high-quality Chinese materia medica (CMM, individual medicinal plant parts used in the NHQWP) to prepare three batches of TCM reference drugs (TCMRD). Pure compounds of the active ingredients identified in the herbal formula including berberine hydrochloride, geniposide, forsythiaside A, 3,5-O-dicaffeoyl quinic acid, hesperidin, baicalin, glycyrrhizic acid, and chrysophanol in the three TCMRDs were analyzed as well as those in 49 batches of commercial products from 18 manufacturers by ultra-performance liquid chromatography (UPLC) method combined with wavelength switching. Using the TCMRD as the scientific ruler, quality grade specifications of NHQWP were proposed by comprehensive analysis of multiple components. Accordingly, 13, 28, and 8 batches of samples were primarily rated as first-grade, second-grade, and unqualified, respectively
Resonances in and
A partial wave analysis is presented of and
from a sample of 58M events in the BES II detector. The
is observed clearly in both sets of data, and parameters of the
Flatt\' e formula are determined accurately: (stat)
(syst) MeV/c, MeV/c, . The data also exhibit a strong peak
centred at MeV/c. It may be fitted with and a
dominant signal made from interfering with a smaller
component. There is evidence that the signal is
resonant, from interference with . There is also a state in with MeV/c and
MeV/c; spin 0 is preferred over spin 2. This state, , is
distinct from . The data contain a strong peak due to
. A shoulder on its upper side may be fitted by interference
between and .Comment: 17 pages, 6 figures, 1 table. Submitted to Phys. Lett.
Measurement of the Branching Fraction of J/psi --> pi+ pi- pi0
Using 58 million J/psi and 14 million psi' decays obtained by the BESII
experiment, the branching fraction of J/psi --> pi+ pi- pi0 is determined. The
result is (2.10+/-0.12)X10^{-2}, which is significantly higher than previous
measurements.Comment: 9 pages, 8 figures, RevTex
Search for K_S K_L in psi'' decays
K_S K_L from psi'' decays is searched for using the psi'' data collected by
BESII at BEPC, the upper limit of the branching fraction is determined to be
B(psi''--> K_S K_L) < 2.1\times 10^{-4} at 90% C. L. The measurement is
compared with the prediction of the S- and D-wave mixing model of the
charmonia, based on the measurements of the branching fractions of J/psi-->K_S
K_L and psi'-->K_S K_L.Comment: 5 pages, 1 figur
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