Browsing PubMed by Issue Date
Now showing items 1-20 of 91
-
Evolutionary route to diploidy and sex
(National Academy of Sciences, 2001-11-20)By using a bit-string model of evolution, we find a successful route to diploidy and sex in simple organisms. Allowing the sexually reproducing diploid individuals to also perform mitosis, as they do in a haploid-diploid ... -
Strategies for the evolution of sex
(American Physical Soc, One Physics Ellipse, 2001-12)We find that the hypothesis made by Jan, Stauffer, and Moseley [Theory Biosci. 119, 166 (2000)] for the evolution of sex, namely, a strategy devised to escape extinction due to too many deleterious mutations, is sufficient ... -
Computational model of the ventricular action potential in adult spontaneously hypertensive rats
(2003-09-01)Introduction: Cardiac hypertrophy has substantial clinical significance because many hypertrophic cells have markedly prolonged repolarization behavior, which may lead to increased risk for cardiac arrhythmias. Spontaneously ... -
Volumetric ultrasound imaging using 2-D CMUT arrays
(IEEE-Inst Electrical Electronics Engineers Inc, 2003-11)Recently, capacitive micromachined ultrasonic transducers (CMUTs) have emerged as a candidate to overcome the difficulties in the realization of 2-D arrays for real-time 3-D imaging. In this paper, we present the first ... -
Forward-viewing CMUT arrays for medical Imaging
(IEEE-INST Electrical Electronics Engineers Inc, 2004-07)This paper reports the design and testing of forward-viewing annular arrays fabricated using capacitive micromachined ultrasonic transducer (CMUT) technology. Recent research studies have shown that CMUTs have broad frequency ... -
Coherent array imaging using phased subarrays. Part II: Simulations and experimental results
(IEEE-INST Electrical Electronics Engineers Inc, 2005-01)The basic principles and theory of phased subarray (PSA) imaging imaging provides the flexibility of reducing I he number of front-end hardware channels between that of classical synthetic aperture (CSA) imaging-which uses ... -
Coherent-array imaging using phased subarrays. Part I: Basic principles
(IEEE-INST Electrical Electronics Engineers Inc, 2005-01)The front-end hardware complexity of a coherent array imaging system scales with the number of active array elements that are simultaneously used for transmission or reception of signals. Different imaging methods use ... -
Photon transmission study on conformational ordering of iota-carrageenan in CaCl2 solution
(Taylor & Francis Inc, 2005-06)Coil-to-double helix (c-h) and double helix-to-dimer (h-d) phase transitions of iota-carrageenan in CaCl2 solution upon cooling were studied using photon transmission technique. Photon transmission intensity, I-iota r was ... -
Film formation from pure and mixed latices; transient fluorescence study
(Academic Press Inc Elsevier Science, 2005-11-15)A fast transient fluorescence technique was used to study latex film formation induced by organic solvent vapor. Mixtures of pyrene (P)- and naphthalene (N)-labeled and/or pure naphthalene-labeled latex films were prepared ... -
Design of a front-end integrated circuit for 3D acoustic imaging using 2D CMUT arrays
(IEEE-INST Electrical Electronics Engineers Inc, 2005-12)Integration of front-end electronics with 2D capacitive micromachined ultrasonic transducer (CMUT) arrays has been a challenging issue due to the small element size and large channel count. We present design and verification ... -
Annular-ring CMUT arrays for forward-looking IVUS: Transducer characterization and imaging
(IEEE, 2006-02)In this study, a 64-element, 1.15-mm diameter annular-ring capacitive micromachined ultrasonic transducer (CMUT) array was characterized and used for forward-looking intravascular ultrasound (IVUS) imaging tests. The array ... -
Size-dependent self-organization of colloidal particles on chemically patterned surfaces
(SP Zhejiang University Press, 2006-04-14)A study of the self-organization of colloidal particles during the evaporation of particle solutions on chemically patterned surfaces is presented. On a surface with hydrophilic and hydrophobic regions, colloidal particles ... -
Ceramic encapsulated latex composites
(Elsevier Inc, 2006-04-15)This work reports the encapsulation of latex particles in Al(2)O(3)-polystyrene (PS) composite films. These films were prepared from PS particles in Al(2)O(3) dispersion at room temperature in various latex contents. ... -
Vapor-induced film formation from low-T-g particles for different solvent compositions
(Elsevier Inc, 2006-05-15)The photon transmission method was used to study latex film formation from poly(vinyl acetate) (PVAc) particles induced by two different solvents. Films with the same latex content were prepared from PVAc particles and ... -
Universal behaviour of gel formation from acrylamide-carrageenan mixture around the gel point: A fluorescence study
(Taylor & Francis Group, 2006-08)The steady state fluorescence (SSF) technique was used to study the sol-gel transition, for the solution free radical crosslinking copolymerization of acrylamide (AAm) with various carrageenan content. N, N'- methylenebis ... -
Monitoring small molecule diffusion into hydrogels at various temperatures by fluorescence technique
(Elsevier B.V, 2006-12-01)steady state fluorescence technique was used to study small molecule diffusion into polyacrylamide (PAAm) gels at various temperatures. Pyranine (P-y), dissolved in water was introduced as a probe and fluorescence emission ... -
Small molecule diffusion into swelling Iota-Carrageenan gels: A fluorescence study
(Taylor & Francis Group, 2007-04)Small molecule diffusion into Iota-Carrageenan gel was studied by using steady-state fluorescence (SSF) technique. Pyranine, dissolved in water was used as fluorescence probe. Fluorescence emission intensity, I-p, and ... -
Integration of 2D CMUT arrays with front-end electronics for volumetric ultrasound imaging
(IEEE-INST Electrical Electronics Engineers Inc, 2008-02)For three-dimensional (3D) ultrasound imaging, connecting elements of a two-dimensional (2D) transducer array to the imaging system's front-end electronics is a challenge because of the large number of array elements and ... -
Relocating sensor nodes to maximize cumulative connected coverage in wireless sensor networks
(Molecular Diversity Preservation Int, 2008-04)In order to extend the availability of the wireless sensor network and to extract maximum possible information from the surveillance area, proper usage of the power capacity of the sensor nodes is important. Our work ... -
Comment on "Encryption and decryption of images with chaotic map lattices" [Chaos 16, 033118 (2006)]
(American Institute of Physics Inc., 2008-09)In this paper, we comment on the chaotic encryption algorithm proposed by A. N. Pisarchik et al. [Chaos 16, 033118 (2006)]. We demonstrate that the algorithm is not invertible. We suggest simple modifications that can ...
