141 research outputs found

    Optimizing Prescription of Chinese Herbal Medicine for Unstable Angina Based on Partially Observable Markov Decision Process

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    Objective. Initial optimized prescription of Chinese herb medicine for unstable angina (UA). Methods. Based on partially observable Markov decision process model (POMDP), we choose hospitalized patients of 3 syndrome elements, such as qi deficiency, blood stasis, and turbid phlegm for the data mining, analysis, and objective evaluation of the diagnosis and treatment of UA at a deep level in order to optimize the prescription of Chinese herb medicine for UA. Results. The recommended treatment options of UA for qi deficiency, blood stasis, and phlegm syndrome patients were as follows: Milkvetch Root + Tangshen + Indian Bread + Largehead Atractylodes Rhizome (ADR=0.96630); Danshen Root + Chinese Angelica + Safflower + Red Peony Root + Szechwan Lovage Rhizome Orange Fruit (ADR=0.76); Snakegourd Fruit + Longstamen Onion Bulb + Pinellia Tuber + Dried Tangerine peel + Largehead Atractylodes Rhizome + Platycodon Root (ADR=0.658568). Conclusion. This study initially optimized prescriptions for UA based on POMDP, which can be used as a reference for further development of UA prescription in Chinese herb medicine

    What does H7N9 mean and how can we be prepared for the next flu pandemic?

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    Gastric Lavage in Acute Organophosphorus Pesticide poisoning (GLAOP) – a randomised controlled trial of multiple vs. single gastric lavage in unselected acute organophosphorus pesticide poisoning

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    BACKGROUND: Organophosphorus (OP) pesticide poisoning is the most common form of pesticide poisoning in many Asian countries. Guidelines in western countries for management of poisoning indicate that gastric lavage should be performed only if two criteria are met: within one hour of poison ingestion and substantial ingested amount. But the evidence on which these guidelines are based is from medicine overdoses in developed countries and may be irrelevant to OP poisoning in Asia. Chinese clinical experience suggests that OP remains in the stomach for several hours or even days after ingestion. Thus, there may be reasons for doing single or multiple gastric lavages for OP poisoning. There have been no randomised controlled trials (RCTs) to assess this practice of multiple lavages. Since it is currently standard therapy in China, we cannot perform a RCT of no lavage vs. a single lavage vs. multiple lavages. We will compare a single gastric lavage with three gastric lavages as the first stage to assess the role of gastric lavage in OP poisoning. METHODS/DESIGN: We have designed an RCT assessing the effectiveness of multiple gastric lavages in adult OP self-poisoning patients admitted to three Chinese hospitals within 12 hrs of ingestion. Patients will be randomised to standard treatment plus either a single gastric lavage on admission or three gastric lavages at four hour intervals. The primary outcome is in-hospital mortality. Analysis will be on an intention-to-treat basis. On the basis of the historical incidence of OP at the study sites, we expect to enroll 908 patients over three years. This projected sample size provides sufficient power to evaluate the death rate; and a variety of other exposure and outcome variables, including particular OPs and ingestion time. Changes of OP level will be analyzed in order to provide some toxic kinetic data. DISCUSSION: the GLAOP study is a novel, prospective cohort study that will explore to the toxic kinetics of OP and effects of gastric lavage on it. Given the poor information about the impact of gastric lavage on clinical outcomes for OP patients, this study can provide important information to inform clinical practice

    Large anisotropy of magnetic damping in ultrathin epitaxial Fe/GaAs (001) film

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    The magnetization dynamics of ultrathin epitaxial Fe films on GaAs (0 0 1) with different thicknesses have been investigated by all-optical time-resolved magneto-optical Kerr effect. For the Fe film with thickness of 8 monolayers, the magnetic damping constant along orientation increases by 66% compared with that along orientation, showing the uniaxial anisotropy of magnetic damping. By the measurement of angular dependent time-resolved magneto-optical Kerr effect, the uniaxial magnetic damping is clearly correlated to the in-plane uniaxial anisotropy field of the Fe film. In addition, the anisotropy of the damping constants is found to disappear for the Fe films thicker than 15 monolayers, suggesting that the anisotropic damping originates from the interfacial effect between Fe and GaAs

    Direct observation of spin polarization in epitaxial Fe3O4(001)/MgO thin films grown by magnetron sputtering

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    We obtained epitaxial single-crystal Fe3O4(001)/MgO(001) thin films by magnetron sputtering. The high quality of the grown Fe3O4 films was confirmed by reflection high-energy electron diffraction and x-ray photoelectron spectroscopy. Atomic magnetic properties of Fe3O4(001)/MgO(001) were investigated using vibrating sample magnetometry and x-ray magnetic circular dichroism. The values of saturation magnetization and magnetic moment are 407 ± 5 emu/cm3 (3.26 ± 0.04 μ B / (f. u.)) and 3.31 ± 0.15 μ B / (f. u.), respectively, in the Fe3O4 film as thin as 5 nm, which are close to the bulk values. The spin polarization was directly measured using spin-resolved photoemission spectroscopy. The measured spin polarization has a maximum value of -42% ± 3%, which is comparable to the theoretical value for the (2 × 2)R45° reconstructed Fe3O4(001) surface. Furthermore, the film thickness-dependent measurements indicate that the anti-phase boundaries significantly decrease the spin polarization rather than the lattice mismatch. Our results demonstrate that epitaxial Fe3O4(001)/MgO thin films grown by magnetron sputtering have desired magnetic properties, facilitating the potential application of Fe3O4-based spintronic devices

    Ultrafast magnetization enhancement via the dynamic spin-filter effect of type-II Weyl nodes in a kagome ferromagnet

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    The magnetic type-II Weyl semimetal (MWSM) Co3Sn2S2 has recently been found to host a variety of remarkable phenomena including surface Fermi-arcs, giant anomalous Hall effect, and negative flat band magnetism. However, the dynamic magnetic properties remain relatively unexplored. Here, we investigate the ultrafast spin dynamics of Co3Sn2S2 crystal using time-resolved magneto-optical Kerr effect and reflectivity spectroscopies. We observe a transient magnetization behavior, consisting of spin-flipping dominated fast demagnetization, slow demagnetization due to overall half-metallic electronic structures, and an unexpected ultrafast magnetization enhancement lasting hundreds of picoseconds upon femtosecond laser excitation. By combining temperature-, pump fluence-, and pump polarization-dependent measurements, we unambiguously demonstrate the correlation between the ultrafast magnetization enhancement and the Weyl nodes. Our theoretical modelling suggests that the excited electrons are spin-polarized when relaxing, leading to the enhanced spin-up density of states near the Fermi level and the consequently unusual magnetization enhancement. Our results reveal the unique role of the Weyl properties of Co3Sn2S2 in femtosecond laser-induced spin dynamics

    Impurity band assisted carrier relaxation in Cr doped topological insulator Bi2Se3

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    Topological insulators (TIs) with unique band structures have wide application prospects in the fields of ultrafast optical and spintronic devices. The dynamics of hot carriers plays a key role in these TI-based devices. In this work, using the time- and angle-resolved photoemission spectroscopy technique, the relaxation process of the hot carriers in Cr-doped Bi2Se3 has been systematically studied since the ferromagnetic TI is one of the key building blocks for next-generation spintronics. It is found that electronic temperature (Te) and chemical potential (μ) decrease faster with the increase in the Cr doping concentration. Similarly, the lifetime (τ) of the excited electrons also decreases with more Cr doped into Bi2Se3. The results suggest a mechanism of impurity band-assisted carrier relaxation, where the impurity band within the bulk bandgap introduced by Cr doping provides significant recombination channels for the excited electrons. This work directly illustrates the dynamic process of the photon-generated carriers in Cr-doped Bi2Se3, which is expected to promote the applications of (Bi1-xCrx)2Se3 in photoelectric devices
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