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Search Results: 1 - 10 of 110531 matches for " Z. Liu "
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Uneventful Spinal Anesthesia in a Patient with Precipitous Drop of Platelet Secondary to HELLP Syndrome: A Case Report and Review of Literatures  [PDF]
Joe Z Liu, Chunhua Li, Hong Wang
Open Journal of Anesthesiology (OJAnes) , 2012, DOI: 10.4236/ojanes.2012.24031
Abstract: Thrombocytopenia caused by Hemolysis, Elevated Liver enzymes and Low Platelet count (HELLP) syndrome in pre-eclampsia parturients can be associated with substantial maternal and neonatal morbidity. Data on the issue of the safety of neuraxial anesthesia with thrombocytopenia in HELLP syndrome is limited. A lower limit of 100,000 per microliter for platelet count was suggested as “safe” for performing neuraxial anesthesia, however there is no supporting data. This lower limit is challenged lately. We present a case of uneventful spinal anesthesia for urgent Cesarean section in a patient with severe pre-eclamsia, HELLP syndrome and precipitous platelet drop from 230,000 to 42,000 per microliter.
Application of Volatility in Portfolio Construction  [PDF]
Michael Ha, George Z. Liu, Lihui Zheng
Journal of Applied Mathematics and Physics (JAMP) , 2015, DOI: 10.4236/jamp.2015.37099
Abstract:

We studied the CBOE Market Volatility Index from 1995 to 2004 and the Cross-Sectional Volatility of MSCI US and MSCI AC Asia ex Japan of the same period. Tracking Error calculations and Market Volatility Analyses were performed. We selected a portfolio, Dragon, for Risk Analysis, Risk Decomposition and Risk Characteristics identification purposes. A conclusion relating Dragon’s Tracking Error and its Portfolio Size was drawn.

Portfolio Construction for Value Appreciation  [PDF]
Michael Ha, George Z. Liu, Lihui Zheng
Journal of Applied Mathematics and Physics (JAMP) , 2016, DOI: 10.4236/jamp.2016.44076
Abstract:

Background: While working as risk consultants at Barra in 1990’s, the first two authors decided to start collaborating on a research project with its first paper titled “Application of Volatility in Portfolio Construction” [1]. The third author was then a risk manager of a financial institution which was a client of Barra’s. Bringing his expertise in portfolio risk management, he joined the research team. Aim: The core of this paper lies in the construction of an investment portfolio with a main objective of value appreciation while examining its tracking error [1]-[3], a risk measurement with reference to a benchmark [1] [4]. The authors believe, while tracking error measurement is a common tool for portfolio risk management, total risk measurement is more important. The management goal is to minimize drawbacks using the technique of risk budgeting. These topics will be discussed in future research papers.

The Cohomology of Transitive Lie Algebroids
Z. Chen,Z. -J. Liu
Mathematics , 2007,
Abstract: For a transitive Lie algebroid A on a connected manifold M and its a representation on a vector bundle F, we study the localization map Y^1: H^1(A,F)-> H^1(L_x,F_x), where L_x is the adjoint algebra at x in M. The main result in this paper is that: Ker Y^1_x=Ker(p^{1*})=H^1_{deR}(M,F_0). Here p^{1*} is the lift of H^1(\huaA,F) to its counterpart over the universal covering space of M and H^1_{deR}(M,F_0) is the F_0=H^0(L,F)-coefficient deRham cohomology. We apply these results to study the associated vector bundles to principal fiber bundles and the structure of transitive Lie bialgebroids.
Omni-Lie algebroids
Z. Chen,Z. -J. Liu
Mathematics , 2007,
Abstract: A generalized Courant algebroid structure is defined on the direct sum bundle D(E) +J(E), where D(E) and J(E) are the gauge Lie algebroid and the jet bundle of a vector bundle E respectively. Such a structure is called an omni-Lie algebroid since it is reduced to the omni-Lie algebra introduced by A.Weinstein if the base manifold is a point. We prove that any Lie algebroid structure on E is characterized by a Dirac structure as the graph of a bundle map from J(E) to D(E).
On (Co-)morphisms of Lie Pseudoalgebras and Groupoids
Z. Chen,Z. -J. Liu
Mathematics , 2007,
Abstract: We give a unified description of morphisms and comorphisms of Lie pseudoalgebras, showing that the both types of morphisms can be regarded as subalgebras of a Lie pseudoalgebra, called the $\psi$-sum. We also provide similar descriptions for morphisms and comorphisms of Lie algebroids and groupoids.
The NUADU experiment on TC-2 and the first Energetic Neutral Atom (ENA) images recorded by this instrument
C. Shen ,Z. Liu
Annales Geophysicae (ANGEO) , 2005,
Abstract: For Double Star Project (DSP) exploration, the scientific operations are very important and essential for achieving its scientific objectives. Two years before the launch of the DSP satellites (TC-1 and TC-2) and during the mission operating phase, the long-term and short-term master science operations plans (MSOP) were produced. MSOP is composed of the operation schedules of all the scientific instruments, the modes and timelines of the Payload Service System on TC-1 and TC-2, and the data receiving schedules of the three ground stations. The MSOP of TC-1 and TC-2 have been generated according to the scientific objectives of DSP, the orbits of DSP, the near-Earth space environments and the coordination with Cluster, etc., so as to make full use of the exploration resources provided by DSP and to acquire as much quality scientific data as possible for the scientific communities. This paper has summarized the observation resources of DSP, the states of DSP and its evolution since the launch, the strategies and rules followed for operating the payload and utilizing the ground stations, and the production of MSOP. Until now, the generation and execution of MSOP is smooth and successful, the operating of DSP is satisfactory, and most of the scientific objectives of DSP have been fulfilled.
Controlled-release and preserved bioactivity of proteins from (self-assembled) core-shell double-walled microspheres
Yuan W, Liu Z
International Journal of Nanomedicine , 2012, DOI: http://dx.doi.org/10.2147/IJN.S27621
Abstract: ntrolled-release and preserved bioactivity of proteins from (self-assembled) core-shell double-walled microspheres Original Research (2748) Total Article Views Authors: Yuan W, Liu Z Published Date January 2012 Volume 2012:7 Pages 257 - 270 DOI: http://dx.doi.org/10.2147/IJN.S27621 Received: 25 October 2011 Accepted: 13 November 2011 Published: 18 January 2012 Weien Yuan1,2, Zhenguo Liu1 1Department of Neurology, Xinhua Hospital, affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 2School of Pharmacy, Shanghai Jiao Tong University, Shanghai, People’s Republic of China Abstract: In order to address preserved protein bioactivities and protein sustained-release problems, a method for preparing double-walled microspheres with a core (protein-loaded nanoparticles with a polymer-suspended granule system-formed core) and a second shell (a polymer-formed shell) for controlled drug release and preserved protein bioactivities has been developed using (solid-in-oil phase-in-hydrophilic oil-in-water (S/O/Oh/W)) phases. The method, based on our previous microsphere preparation method (solid-in-oil phase-in-hydrophilic oil-in-water (S/O/Oh/W), employs different concentric poly(D,L-lactide-co-glycolide), poly(D,L-lactide), and protein-loaded nanoparticles to produce a suspended liquid which then self-assembles to form shell-core microspheres in the hydrophilic oil phase, which are then solidified in the water phase. Variations in the preparation parameters allowed complete encapsulation by the shell phase, including the efficient formation of a poly(D,L-lactide) shell encapsulating a protein-loaded nanoparticle-based poly(D,L-lactide-co-glycolide) core. This method produces core-shell double-walled microspheres that show controlled protein release and preserved protein bioactivities for 60 days. Based upon these results, we concluded that the core-shell double-walled microspheres might be applied for tissue engineering and therapy for chronic diseases, etc.
Surgical wound healing using hemostatic gauze scaffold loaded with nanoparticles containing sustained-release granulocyte colony-stimulating factor
Yuan W, Liu Z
International Journal of Nanomedicine , 2011, DOI: http://dx.doi.org/10.2147/IJN.S26006
Abstract: rgical wound healing using hemostatic gauze scaffold loaded with nanoparticles containing sustained-release granulocyte colony-stimulating factor Original Research (3099) Total Article Views Authors: Yuan W, Liu Z Published Date December 2011 Volume 2011:6 Pages 3139 - 3149 DOI: http://dx.doi.org/10.2147/IJN.S26006 Weien Yuan1,2, Zhenguo Liu1 1Department of Neurology, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, 2School of Pharmacy, Shanghai Jiao Tong University, Shanghai, People's Republic of China Background: The therapeutic strategies for malignant melanoma are still cancer chemotherapy, radiotherapy, and tumor resection. However, these therapeutic strategies often lead to a reduced neutrophilic granulocyte count or loss of more blood after surgical tumor resection. In this study, we developed a formulation of hemostatic gauze impregnated with sustained-release granulocyte colony-stimulating factor (G-CSF) with increasing of the neutrophilic granulocyte count in the blood following chemotherapy and decreasing blood loss after surgical tumor resection. Methods: We designed a formulation with both hemostatic properties and increased neutrophil content to be used in cancer chemotherapy, radiotherapy, and tumor resection, comprising a hemostatic gauze as a scaffold and (G-CSF)-loaded dextran nanoparticles coated with polylactic-co-glycolic acid (PLGA) solution fabricated by direct spray-painting onto the scaffold and then vacuum-dried at room temperature. The performance of this system was evaluated in vitro and in vivo. Results: Nearly zero-order release of G-CSF was recorded for 12–14 days, and the cumulative release of G-CSF retained over 90% of its bioactivity in a NFS-60 cell line proliferation assay when the scaffold was incubated in phosphate-buffered saline (pH 7.4) at 37°C. The in vivo hemostatic efficacy of this formulation was greater than that of native G-CSF, the scaffold directly spray-painted with G-CSF solution or PLGA organic solution as a coating, or when a blank scaffold was covered with the coating. Conclusion: Our results suggest that this formulation has both hemostatic properties and increased neutrophil activity.
Towards a comprehensive physically-based rainfall-runoff model
Z. Liu,E. Todini
Hydrology and Earth System Sciences (HESS) & Discussions (HESSD) , 2002,
Abstract: This paper introduces TOPKAPI (TOPographic Kinematic APproximation and Integration), a new physically-based distributed rainfall-runoff model deriving from the integration in space of the kinematic wave model. The TOPKAPI approach transforms the rainfall-runoff and runoff routing processes into three ‘structurally-similar’ non-linear reservoir differential equations describing different hydrological and hydraulic processes. The geometry of the catchment is described by a lattice of cells over which the equations are integrated to lead to a cascade of non-linear reservoirs. The parameter values of the TOPKAPI model are shown to be scale independent and obtainable from digital elevation maps, soil maps and vegetation or land use maps in terms of slope, soil permeability, roughness and topology. It can be shown, under simplifying assumptions, that the non-linear reservoirs aggregate into three reservoir cascades at the basin scale representing the soil, the surface and the drainage network, following the topographic and geomorphologic elements of the catchment, with parameter values which can be estimated directly from the small scale ones. The main advantage of this approach lies in its capability of being applied at increasing spatial scales without losing model and parameter physical interpretation. The model is foreseen to be suitable for land-use and climate change impact assessment; for extreme flood analysis, given the possibility of its extension to ungauged catchments; and last but not least as a promising tool for use with General Circulation Models (GCMs). To demonstrate the quality of the comprehensive distributed/lumped TOPKAPI approach, this paper presents a case study application to the Upper Reno river basin with an area of 1051 km2 based on a DEM grid scale of 200 m. In addition, a real-world case of applying the TOPKAPI model to the Arno river basin, with an area of 8135 km2 and using a DEM grid scale of 1000 m, for the development of the real-time flood forecasting system of the Arno river will be described. The TOPKAPI model results demonstrate good agreement between observed and simulated responses in the two catchments, which encourages further developments of the model. Keywords: rainfall-runoff modelling, topographic, kinematic wave approximation, spatial integration, physical meaning, non-linear reservoir model, distributed and lumped
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