73 research outputs found
Evolution of High-Energy Particle Distribution in Mature Shell-Type Supernova Remnants
Multi-wavelength observations of mature supernova remnants (SNRs), especially
with recent advances in gamma-ray astronomy, make it possible to constrain
energy distribution of energetic particles within these remnants. In
consideration of the SNR origin of Galactic cosmic rays and physics related to
particle acceleration and radiative processes, we use a simple one-zone model
to fit the nonthermal emission spectra of three shell-type SNRs located within
2 degrees on the sky: RX J1713.7-3946, CTB 37B, and CTB 37A. Although radio
images of these three sources all show a shell (or half-shell) structure, their
radio, X-ray, and gamma-ray spectra are quite different, offering an ideal case
to explore evolution of energetic particle distribution in SNRs. Our spectral
fitting shows that 1) the particle distribution becomes harder with aging of
these SNRs, implying a continuous acceleration process, and the particle
distributions of CTB 37A and CTB 37B in the GeV range are harder than the
hardest distribution that can be produced at a shock via the linear diffusive
shock particle acceleration process, so spatial transport may play a role; 2)
the energy loss timescale of electrons at the high-energy cutoff due to
synchrotron radiation appears to be always a bit (within a factor of a few)
shorter than the age of the corresponding remnant, which also requires
continuous particle acceleration; 3) double power-law distributions are needed
to fit the spectra of CTB 37B and CTB 37A, which may be attributed to shock
interaction with molecular clouds.Comment: Accepted for publication in The Astrophysical Journal, 11 pages, 3
figures, 1 tabl
Interventions to Promote Follow-up After Trabeculectomy Surgery in Rural Southern China: A Randomized Clinical Trial.
Preoperative characteristics and compliance with follow-up after trabeculectomy surgery in rural southern China
Associations between ALDOB polymorphisms and intrahepatic cholestasis of pregnancy susceptibility in the Chinese Han population
Objectives: To research the associations between fructose-bisphosphate aldolase B (ALDOB) gene polymorphisms and intrahepatic cholestasis of pregnancy (ICP) risk.
Material and methods: Whole-genome sequencing (WGS) was performed to detect ALDOB polymorphisms. Five web-available tools were employed to predict the effect of the site variant on the protein. Protein structure comparisons between the reference and ALDOB-modified samples were performed by SWISS-MODEL and Chimera 1.14rc, respectively.
Results: We identified 28 genetic variants in the ALDOB gene. When the cut-off value of minor allele frequency (MAF) of loci was 0.001 in four databases, five missense variants, including rs747604233, rs759204107, rs758242037, rs371526091 and rs77718928, were reserved for subsequent analysis. These variants were absent from the 1029 control individuals. The influence of all five variants on protein function was predicted to be damaging by the abovementioned five prediction software programs. Bioinformatics analysis demonstrated that these five missense variants were highly conserved among vertebrates. Compared to the wild-type protein structure, all five mutated protein structures showed a slight change in the chemical bond lengths of the enzyme activity domains. The combined clinical data indicate that the variant group had a significantly older age (p = 0.038), a higher level of indirect bilirubin (IDBIL, p = 0.033), and lower counts of white blood cells (WBCs, p = 7.38E-05) and platelets (PLTs, p = 0.018) than the wild-type group.
Conclusions: This is the first study to examine the associations between ALDOB polymorphisms and ICP disease in 249 Chinese patients with ICP. Our present study expands the understanding of the pathogenesis of ICP
3% diquafosol sodium eye drops in Chinese patients with dry eye: a phase IV study
IntroductionThe efficacy and safety of 3% diquafosol sodium eye drops in Chinese patients with dry eye in the real-world setting remains unclear.Methods3099 patients with dry eye symptoms were screened according to Asia Dry Eye Society latest recommendation. Among them, 3000 patients were enrolled for a phase IV study. We followed up with multiple clinical characteristics including corneal fluorescein staining, tear break up time, Schirmer’s tests, visual acuity, intraocular pressure, and others. The follow ups were performed at baseline, 2 weeks and 4 weeks after treatment.ResultsBased on the results of corneal fluorescein staining and tear break up time, all age and gender subgroups exhibited obvious alleviation of the symptoms among the patients with dry eye, and the data in elderly group showed the most significant alleviation. All the adverse drug reactions (ADRs, 6.17%) were recorded, among which 6% local ocular ADRs were included. Meanwhile, mild ADRs (91.8%) accounted for the most. Most of the ADRs (89.75%) got a quick and full recovery, with an average time at 15.6 days. 1.37% of patients dropped out of the study due to ADRs.DiscussionThe use of 3% diquafosol sodium eye drop is effective and safe in the treatment of dry eye, with a low incidence of ADRs showing mild symptoms. This trial was registered at Chinese Clinical Trial Registry ID: ChiCTR1900021999 (Registration Date: 19/03/2019)
A Dynamic Strategy for Home Pick-Up Service with Uncertain Customer Requests and Its Implementation
In this paper, a home service problem is studied, where a capacitated vehicle collects customers’ parcels in one pick-up tour. We consider a situation where customers, who have scheduled their services in advance, may call to cancel their appointments, and customers, who do not have appointments, also need to be visited if they request for services as long as the capacity is allowed. To handle those changes that occurred over the tour, a dynamic strategy will be needed to guide the vehicle to visit customers in an efficient way. Aimed at minimizing the vehicle’s total expected travel distance, we model this problem as a multi-dimensional Markov Decision Process (MDP) with finite exponential scale state space. We exactly solve this MDP via dynamic programming, where the computing complexity is exponential. In order to avoid complexity continually increasing, we aim to develop a fast looking-up method for one already-examined state’s record. Although generally this will result in a huge waste of memory, by exploiting critical structural properties of the state space, we obtain an O ( 1 ) looking-up method without any waste of memory. Computational experiments demonstrate the effectiveness of our model and the developed solution method. For larger instances, two well-performed heuristics are proposed
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