Search Results - (Author, Cooperation:W. Jeong)

2018-05-04

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Geosciences

Computer Science

Medicine

Natural Sciences in General

Physics

Evolution, Genetics

2018-04-09

Institute of Physics (IOP)

1757-8981

1757-899X

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

2018-04-09

Institute of Physics (IOP)

1757-8981

1757-899X

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

2018-07-03

The Society of Nuclear Medicine (SNM)

0022-3123

Medicine

2015-12-08

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

2013-06-15

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

2018-02-27

American Physical Society (APS)

1098-0121

1095-3795

Physics

Magnetism

1550-7408

Blackwell Publishing Journal Backfiles 1879-2005

Biology

. The unusual nature of mitosis and ancestral organization of the dinoflagellate nucleus prompted the question of whether the cdc2-like histone H1 kinase, a presumed ubiquitous cell cycle regulator in eukaryotes, is present in these primitive organisms. Western blotting of Crypthecodinium cohnii protein extracts using antibody against the Pro-Ser-Thr-Ala-Ile-Arg-Glu (=PSTAIRE) amino acid sequence motif, conserved in all cdc2 homologues known, revealed one prominent band corresponding to a protein with an apparent relative molecular weight ≈ 34,000, identical in mobility to that from HeLa cells and Physarum polycephalum, higher and lower eukaryotic controls, respectively. Incubation of C. cohnii cell lysates with p13suc1-sepharose beads, which preferentially, though not exclusively, bind p34cdc2, resulted in precipitation of a 34-kDa protein which was reactive with anti-PSTAIRE antibody, selectively competed for by the PSTAIRE peptide and able to phosphorylate histone H1 in vitro. We conclude that the dinoflagellate C. cohnii contains a protein very similar to the cdc2 gene product from fission yeast and its homologues in all eukaryotes studied thus far.

Electronic Resource

1550-7408

Blackwell Publishing Journal Backfiles 1879-2005

Biology

. Gram- symbiotic X-bacteria present in the xD strain of Amoeba proteus as required cell components, synthesize and export a large amount of a 29-kDa protein (S29x) into the host's cytoplasm across bacterial and symbiosome membranes. The S29x protein produced by E. coli transformed with the s29x gene is also rapidly secreted into the culture medium. Inside amoebae, S29x enters the host's nucleus as detected by confocal and irnmunoelectron microscopy, although it is not clear if S29x is selectively accumulated inside the nucleus. The deduced amino-acid sequence of S29x has a stretch of basic amino acids that could act as a nuclear localization signal, but there is no signal peptide at the N-terminus and the transport of S29x is energy independent. The functions of S29x are not known, but in view of its prominent presence inside the amoeba's nucleus, S29x is suspected to be involved in affecting the expression of amoeba's nuclear gene(s).

Electronic Resource

1077-3118

AIP Digital Archive

Physics

Single and multiple quantum well samples have been grown by atmospheric pressure metalorganic chemical vapor deposition at In compositions from 9 to 28% and layer thicknesses ranging from 15 to 140 A(ring), depending upon the composition. Selected samples containing three quantum wells of a given composition but with different thicknesses were characterized by x-ray double-crystal diffractometry, low-temperature photoluminescence, and transmission electron microscopy (TEM). Using a simulation technique based on the dynamical theory of x-ray diffraction in concert with TEM measurements, the In composition in the quantum well as well as the thicknesses can be directly extracted. The peak positions of the photoluminescence are used to determine the strained and unstrained energy gap and the conduction band offsets associated with InxGa1−xAs of a given composition. We have found the discontinuities to be 60% of the difference in the energy gap of GaAs and strained InxGa1−xAs.

Electronic Resource

1077-3118

AIP Digital Archive

Physics

We report on the first observation of stimulated emission from Hg-based quantum well structures in which the active region is a HgCdTe superlattice. The laser structures were grown on (100) CdZnTe substrates photoassisted molecular beam epitaxy. Cleaved laser cavities were optically pumped using the 1.06 μm output from a cw Nd:YAG laser. Stimulated emission cavity modes were seen at cw laser power densities as low as 3.4 kW/cm2 and at temperatures ≥ 60 K.

Electronic Resource

1077-3118

AIP Digital Archive

Physics

At North Carolina State University, we have recently employed photoassisted molecular beam epitaxy to successfully prepare p-type modulation-doped HgCdTe. The modulation-doped HgCdTe samples were grown on lattice-matched (100) CdZnTe substrates cut from boules grown at Santa Barbara Research Center. In this letter, we report details of the growth experiments and describe the structural, optical, and electrical properties that this new infrared quantum alloy of HgCdTe possesses.

Electronic Resource

1077-3118

AIP Digital Archive

Physics

The light hole to conduction band optical transition has been identified in the room-temperature absorption spectra of several high quality HgTe-HgCdTe superlattices, in addition to the familiar heavy hole to conduction band transitions. The observation of the light hole transition, coupled with a more accurate determination of the superlattice layer thicknesses, allows the superlattice band gap and the HgTe-HgCdTe valence band offset to be determined more precisely than previously possible. A two-band tight-binding model was used to calculate the transition energies to compare with the optical data. The valence band offset for the HgTe-Hg0.15 Cd0.85 Te interface was determined to be 300±25 meV.

Electronic Resource

1077-3118

AIP Digital Archive

Physics

GaAs has been selectively grown in a hexagonally ordered array of nanometer-scale holes with a density as high as ∼1011/cm2 by metalorganic chemical vapor deposition. This array of holes was created using block copolymer lithography, in which a thin layer of diblock copolymer was used as an etching mask to make dense holes in a 15-nm-thick SiNx film. These selectively grown nanoscale features are estimated to be 23 nm in diameter with narrow lateral size and height distributions as characterized by field-emission scanning electron microscopy and tapping mode atomic force microscopy. The narrow size distribution and uniform spatial position of the nanoscale dots we report offer potential advantages over self-assembled dots grown by the Stranski–Krastanow mode. © 2000 American Institute of Physics.

Electronic Resource

1750-3841

Blackwell Publishing Journal Backfiles 1879-2005

Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition

Process Engineering, Biotechnology, Nutrition Technology

: The phytosterol compositions in unsaponifiables of fig (Ficus carica, var. Mission) fruit and 3 structural components of the branches; and the fatty acid composition of fig fruits were studied using gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS). The phytosterols were determined from the trimethylsilyl ether (TMS) derivatives of the unsaponifiable samples. Fourteen compounds were separated from fig fruit; 13, 10, and 6 in bark, stem, and pith, respectively. Sitosterol was the most predominant sterol in all parts. Also detected were campesterol, stigmasterol, and fucosterol. Fatty acids in fig fruit, determined as their methyl esters, were myristic (14:0), palmitic (16:0), stearic (18:0), oleic (18:1), linoleic (18:2), and linolenic (18:3) acids.

Electronic Resource

0022-328X

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Chemistry and Pharmacology

Electronic Resource

1435-1536

Key words Epoxy acrylate dispersions ; urethane acrylate anionomers ; two hydrophilic ionic segments ; ionic interaction ; final film properties

Springer Online Journal Archives 1860-2000

Chemistry and Pharmacology

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

Abstract  Epoxy acrylate dispersions stabilized using urethane acrylate anionomers were prepared for an application of ultraviolet (UV) curing. By observing the optical microscopy and colloidal stability for the epoxy acrylate dispersions, it was confirmed that the urethane acrylate anionomers incorporated have an interfacial activity in the interface between the epoxy acrylate oil and the water/ ethanol mixture (80/20, w/w). This was possible by the structurally designed urethane acrylate anionomers, containing a hydrophobic soft segment and two hydrophilic ionic sites in their molecules. In addition, when ultraviolet (UV)-cured, the urethane acrylate anionomers agglomerated to form the rubber domains in the epoxy acrylate film, which were induced by the ionic interaction. Consequently, this agglomerated rubber domains improved the final film properties.

Electronic Resource

1573-2711

spreading ; thin liquid films ; perfluoropolyalkylethers ; chain-end functionality ; humidity ; ellipsometry

Springer Online Journal Archives 1860-2000

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

Abstract Spreading characteristics of thin liquid films of perfluoropolyalkyl ethers (PFPE) on silica surfaces and thermally bonded PFPE surfaces have been measured by scanning microellipsometer as function of molecular weight, chain-end functionality, and humidity. The effects of molecular weight are much smaller than those of chain-end functionality. Changes in spreading profiles with time show that interactions of chain-end groups with solid surfaces have dramatic effects on the structure and mobility of thin polymer films on solid surfaces. Wetting autophobicity is clearly manifested by PFPEs with functional chain-end groups on silica surfaces.

Electronic Resource

0021-9304

cell culture ; CHO cells ; cellulose membrane ; phosphorylation ; cell aggregation ; Chemistry ; Polymer and Materials Science

Wiley InterScience Backfile Collection 1832-2000

Medicine

Technology

Phosphate groups (negatively charged chemical groups) were grafted onto the surface of cellulose membranes by a reaction between hydroxyl groups of cellulose and phosphorus pentoxide to observe the effect of phosphate groups on cellular behavior. X-ray photoelectron spectroscopy (XPS) was used to determine phosphorylation. Captive bubble contact angle measurement was used to determine surface wettability. XPS was also used to analyze serum protein adsorption. Chinese hamster ovary (CHO) cells were maintained in Ham's F-12 nutrient mixture with and without fetal calf serum. Total cell area and shape factor were analyzed using image-analyzing software. Serum proteins showed higher adsorption on phosphated cellulose. Cell spreading on phosphated membranes was greater than on the cellulose membrane that served as control. The cell growth rate was faster compared to the control. Large cell aggregates were not found on the phosphated membranes, in contrast to the control membrane. The cells on the control were aggregated regardless of the existence of divalent cations in the medium. © 1998 John Wiley & Sons, Inc. J Biomed Mater Res, 40, 401-406, 1998.

8 Ill.

Electronic Resource