Search Results - (Author, Cooperation:G. Wei)

2018-04-05

Institute of Physics (IOP)

1757-8981

1757-899X

Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics

2013-03-16

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Computer Science

Medicine

Natural Sciences in General

Physics

Animals ; *Biological Evolution ; Birds/*anatomy & histology ; Feathers/*anatomy & histology ; *Fossils ; Hindlimb/*anatomy & histology ; Wings, Animal/*anatomy & histology

2013-07-05

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

DNA-Binding Proteins ; Drosophila Proteins ; Erythrocytes/cytology/metabolism/parasitology ; *Gene Silencing ; Genes, Protozoan/genetics ; Histones/chemistry/*metabolism ; Introns/genetics ; Lysine/metabolism ; Malaria Vaccines/genetics ; Methylation ; Plasmodium falciparum/*genetics/metabolism/*pathogenicity ; Promoter Regions, Genetic/genetics ; Protozoan Proteins/genetics/*metabolism ; RNA, Long Noncoding/genetics ; Transcription Factors ; Transcription Initiation Site ; Virulence/genetics ; Virulence Factors/*genetics

1432-0843

Springer Online Journal Archives 1860-2000

Medicine

Summary P388 murine leukemic cells lines which were resistant (P388R) or sensitive (P388S) to adriamycin (adr) were used to evaluate the potential utility of in vitro clonogenic assays for detecting and quantitating the number of adr-resistant cells present in a cell mixture. The progeny of P388S cells that had been exposed for 1 h or continuously to adr were as sensitive to the drug as the original P388S cells. Serial passages in the presence of adr, however, resulted in the selection of adr-resistant cells, but even these cells varied in their level of resistance. When P388S and P388R cells were mixed together and exposed to adr, the clonogenic assay consistently overestimated the proportion of P388S cells present. These studies demonstrate some of the inherent limitations of clonogenic drug sensitivity assays and may provide an explanation for the reported discrepancies between in vitro drug sensitivity and clinical responses to therapy reported in the literature.

Electronic Resource

2018-03-06

Cold Spring Harbor Laboratory Press

1549-5469

Biology

Medicine

2018-03-06

The American Association for Cancer Research (AACR)

1078-0432

1557-3265

Medicine

2018-06-15

American Society of Hematology (ASH)

0006-4971

1528-0020

Biology

Medicine

Myeloid Neoplasia

2018-02-09

American Society of Hematology (ASH)

0006-4971

1528-0020

Biology

Medicine

Thrombosis and Hemostasis, Vascular Biology

2018-12-15

The American Association for Cancer Research (AACR)

1078-0432

1557-3265

Medicine

1077-3118

AIP Digital Archive

Physics

An effective interstitial surface recombination velocity for the buried Si-SiO2 interface in separation by implantation of oxygen (SIMOX) material has been used to accurately model the oxidation-enhanced diffusion of boron and phosphorous in single- and multiple-implant material. The effective recombination velocity at the SIMOX interface was found to be higher than the value for a thermally grown SiO2 interface. The enhancement of the effective recombination velocity is dependent on the material formation conditions and is empirically related to the near-interface dislocation density. Increased surface interfacial area is considered to be the most likely cause for the increased effective recombination velocity.

Electronic Resource

1077-3118

AIP Digital Archive

Physics

In this letter, an rf-excited, anodized aluminum structure waveguide CO2 laser is presented, which has the advantages of low cost, better cooling, and ease of manufacture. With this structure, we have obtained 12 W EH11 waveguide mode output power from only a 300 mm gain length.

Electronic Resource

1089-7666

AIP Digital Archive

Physics

Burgers' equation, involving very high Reynolds numbers, is numerically solved by using a new approach based on the distributed approximating functional for representing spatial derivatives of the velocity field. For moderately large Reynolds numbers, this simple approach can provide very high accuracy while using a small number of grid points. In the case where the Reynolds number ≥105, the exact solution is not available and a discrepancy exists in the literature. Our results clarify the behavior of the solution under these conditions. © 1997 American Institute of Physics.

Electronic Resource

1089-7690

AIP Digital Archive

Physics

Chemistry and Pharmacology

Expressions for the transport coefficients of a moderately dense gas are obtained, based on a recently derived density corrected quantum Boltzmann equation. Linearization of the equations determining the pair correlation and the "free'' singlet density operators about local equilibrium is discussed first. The rate of change of the pair correlations is treated as dynamic effects for pairs of particles relaxing to local equilibrium via a relaxation time model arising from interactions with "third particles.'' In contrast, the singlet density operator satisfies a Boltzmann equation with binary collisions. Spatially inhomogeneous corrections to the collision superoperator are included. Contributions to the transport coefficients arise from the perturbation from local equilibrium through fluxes associated with kinetic, collisional and, for the thermal conductivity, potential energy mechanisms. A comparison is made between the classical limit of the transport coefficient expressions obtained here and the classical expressions previously derived from the Boltzmann equation with the nonlocal collision corrections of Green and Bogoliubov. © 1996 American Institute of Physics.

Electronic Resource

1089-7690

AIP Digital Archive

Physics

Chemistry and Pharmacology

A recently formulated density corrected quantum Boltzmann equation emphasizes the need to explicitly include pair correlations and the conversion of kinetic energy to potential energy as important effects in the kinetic theory of moderately dense gases. This paper first considers an appropriate evolution equation for the pair correlations which includes their decay via interactions with other particles in the gas. The molecular description is given of such a gas close to local thermal equilibrium, together with expressions for the associated hydrodynamic variables. Wigner functions are used to uniquely separate macroscopic and microscopic properties. An accompanying paper solves the combination of linearized Boltzmann and correlated pair equations to obtain expressions for the transport coefficients. © 1996 American Institute of Physics.

Electronic Resource

1089-7690

AIP Digital Archive

Physics

Chemistry and Pharmacology

The Fokker–Planck equation is solved by the method of distributed approximating functionals via forward time propagation. Numerical schemes involving higher-order terms in Δt are discussed for the time discretization. Three typical examples (a Wiener process, an Ornstein–Uhlenbeck process, and a bistable diffusion model) are used to test the accuracy and reliability of the present approach, which provides solutions that are accurate up to ten significant figures while using a small number of grid points and a reasonably large time increment. Two sets of solutions for the bistable system, one computed using the eigenfunction expansion of a preceding paper and the other using the present time-dependent treatment, agree to no fewer than five significant figures. It is found that the distributed approximating functional method, while simple in its implementation, yields the most accurate numerical solutions yet available for the Fokker–Planck equation. © 1997 American Institute of Physics.

Electronic Resource

1089-7690

AIP Digital Archive

Physics

Chemistry and Pharmacology

Formal collision theory indicates that the absolute termolecular recombination reaction rate can be expressed in a form associated either with direct or indirect mechanisms for the recombination. Moreover, the same exact rate constant can be calculated using either of the four mechanisms. These results are to be contrasted to the rate constants standardly calculated by approximate methods. © 1997 American Institute of Physics.

Electronic Resource

1089-7690

AIP Digital Archive

Physics

Chemistry and Pharmacology

The distributed approximating functional method is applied to the solution of the Fokker–Planck equations. The present approach is limited to the standard eigenfunction expansion method. Three typical examples, a Lorentz Fokker–Planck equation, a bistable diffusion model and a Henon–Heiles two-dimensional anharmonic resonating system, are considered in the present numerical testing. All results are in excellent agreement with those of established methods in the field. It is found that the distributed approximating functional method yields the accuracy of a spectral method but with a local method's simplicity and flexibility for the eigenvalue problems arising from the Fokker–Planck equations. © 1997 American Institute of Physics.

Electronic Resource

1089-7690

AIP Digital Archive

Physics

Chemistry and Pharmacology

This paper introduces a discrete singular convolution algorithm for solving the Fokker–Planck equation. Singular kernels of the Hilbert-type and the delta type are presented for numerical computations. Various sequences of approximations to the singular kernels are discussed. A numerical algorithm is proposed to incorporate the approximation kernels for physical applications. Three standard problems, the Lorentz Fokker–Planck equation, the bistable model and the Henon–Heiles system, are utilized to test the accuracy, reliability, and speed of convergency of the present approach. All results are in excellent agreement with those of previous methods in the field. © 1999 American Institute of Physics.

Electronic Resource

1089-7690

AIP Digital Archive

Physics

Chemistry and Pharmacology

A newly developed distributed approximating functional (DAF)-wavelet, the Dirichlet–Gabor DAF-wavelet (DGDW), is applied in a calculation of the state-to-state reaction probabilities for the three-dimensional (3-D) (J=0)H+H2 reaction, using the time-independent wave-packet reactant-product decoupling (TIWRPD) method. The DGDWs are reconstructed from a rigorous mathematical sampling theorem, and are shown to be DAF-wavelet generalizations of both the sine discrete variable representation (sinc-DVR) and the Fourier distributed approximating functionals (DAFs). An important feature of the generalized sinc-DVR representation is that the grid points are distributed at equally spaced intervals and the kinetic energy matrix has a banded, Toeplitz structure. Test calculations show that, in accordance with mathematical sampling theory, the DAF-windowed sinc-DVR converges much more rapidly and to higher accuracy with bandwidth, 2W+1. The results of the H+H2 calculation are in very close agreement with the results of previous TIWRPD calculations, demonstrating that the DGDW representation is an accurate and efficient representation for use in FFT wave-packet propagation methods, and that, more generally, the theory of wavelets and related techniques have great potential for the study of molecular dynamics. © 1998 American Institute of Physics.

Electronic Resource

1089-7690

AIP Digital Archive

Physics

Chemistry and Pharmacology

For a closed system, the integration (trace in the quantum case) over one particle of a reduced distribution function is related to the reduced distribution function of one lower order. The particular details of this "chain" relation depend sensitively on the detailed manner in which the reduced distribution functions are defined, specifically their normalization. Correlation functions are defined in terms of reduced distribution functions, which fixes the normalization of the correlation functions and, provided they exist, their associated chain relations. Chain relations for the correlation functions are shown to exist for normalizations of generic type but not for normalizations of specific type. The normalization requirement is shown, in general, to prevent the direct association of correlation functions with physical clusters, which is commonly assumed in the literature. These relations are illustrated for an ideal gas of monomers and dimers. The effect of taking the thermodynamic limit on the chain relations for this system is discussed. This illustrates how the thermodynamic limit generally destroys the chain relations. © 1998 American Institute of Physics.

Electronic Resource