Search Results - (Author, Cooperation:A. Chang)

2018-02-16

American Chemical Society (ACS)

0006-2960

1520-4995

Biology

Chemistry and Pharmacology

2018-04-17

American Chemical Society (ACS)

Chemistry and Pharmacology

2018-08-01

Genetics Society of America (GSA)

2160-1836

Biology

2018-10-27

American Chemical Society (ACS)

0002-7863

1520-5126

Chemistry and Pharmacology

2012-02-18

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

*Biological Evolution ; Cell Wall/metabolism ; Cytoplasm/metabolism ; Epigenesis, Genetic ; Genetic Association Studies ; Genetic Variation/genetics ; Genotype ; Heat-Shock Proteins/genetics/metabolism ; Laboratories ; Meiosis ; Peptide Termination Factors/genetics/metabolism ; *Phenotype ; Prions/genetics/*metabolism ; Saccharomyces cerevisiae/*classification/cytology/*genetics/metabolism ; Saccharomyces cerevisiae Proteins/genetics/metabolism ; Transcription Factors/genetics/metabolism

2014-04-18

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

Aggression/*physiology ; Animals ; Estrogen Receptor alpha/*metabolism ; Female ; Integrases/genetics/metabolism ; Male ; Mice ; Neurons/*metabolism ; Optogenetics ; Sexual Behavior, Animal/*physiology ; Ventromedial Hypothalamic Nucleus/*cytology/*physiology

2013-08-09

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

Animals ; *Connectome ; Drosophila/*physiology ; Female ; *Models, Biological ; Motion Perception/*physiology ; Visual Pathways/cytology/*physiology

0018-019X

Chemistry ; Organic Chemistry

Wiley InterScience Backfile Collection 1832-2000

Chemistry and Pharmacology

Für Coleon B, C19H20O6, den gelben Farbstoff aus Blattdrüsen von Coleus igniarius Schweinf. (Labiatae) wird Struktur 1 bewiesen. Die absolute Konfiguration wurde durch Überführung in 19-Nor-dihydro-royleanon-trimethyläther und Vergleich mit dem konfigurativ verknüpften Dihydro-royleanon-trimethyläther bestimmt. Für die besondere chemische Reaktivität von Coleon B ist einerseits der Hydrochinonring C und andererseits das die Ringe A und B umfassende konjugierte Hexadiendion-System verantwortlich. Sie wurde durch zahlreiche Reaktionen belegt.Die früher [5] erwähnte ( - )-Coleus-Substanz C hat sich als Gemisch aus Spinasterin und Dihydrospinasterin, die (+)-Substanz D als α-Amyrin erwiesen.

14 Ill.

Electronic Resource

2018-02-20

Institute of Physics (IOP)

1757-8981

1757-899X

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

2018-12-18

Institute of Physics Publishing (IOP)

1748-0221

Physics

1089-7623

AIP Digital Archive

Physics

Electrical Engineering, Measurement and Control Technology

Scanning tunneling spectroscopy (STS) capable of measuring the local density of states dI/dV=G(V,x,y) correlated with the topography z(x,y) is implemented on a PC/AT computer system. An algorithm using dimensional decoupling and recursive linking is incorporated in a compact C-language code to achieve flexible and sophisticated STS control. Data acquisition and processing methods which provide the local density of states G(V,x,y,s) at different tip heights s in registry with z(x,y) are described. Examples of novel low-temperature experiments are given to show the capabilities of this implementation of STS.

Electronic Resource

1471-0528

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Objective To assess the capability of a computer software interpretation program, using intrapartum fetal heart rate and intrauterine pressure as recorded in a cardiotocogram to predict fetal acidosis at birth.Design and subjects A retrospective analysis of digitised fetal heart rate and uterine activity values obtained from 73 high risk women in labour.Setting Two university teaching hospitals.Methods A computer software program was constructed to analyse the digitised data and predict acidosis. The results of the analysis were compared with actual umbilical arterial blood pH and base excess at delivery.Results The software cardiotocogram interpreter was able to predict a pH of less than 7.15 with an accuracy of 77%, a sensitivity of 88% and specificity of 75% in this set of data. It was able to predict a base excess of less than –8 mmol/1 with an accuracy of 81%, a sensitivity of 76% and specificity of 82%.Conclusions A computerised method of analysing fetal heart rate and uterine activity using a simple algorithm has demonstrated a capability to predict fetal acidosis at the time of delivery. Further research in this area is warranted.

Electronic Resource

1471-0528

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Electronic Resource

1365-2133

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Electronic Resource

1077-3118

AIP Digital Archive

Physics

We have examined fluctuations in the tunneling current of 3.5 nm SiO2 barriers for voltages in the direct tunneling regime. We find a 1/f power law for the spectral density of the fluctuations where f is the frequency. This 1/f noise can be attributed to fluctuations of a trap assisted tunneling current through the oxide that causes current noise but is not evident in the I–V curves. We suggest that this noise may be a more sensitive probe of trap assisted tunneling and degradation in thin oxides than other measures. At voltages above a threshold of 2.5 V, we observe the reversible onset of non-Gaussian current transients in the noise. The onset of these current transients can be related to a transition in the spacial uniformity of the tunneling current density that may result in eventual breakdown of the oxide. © 1996 American Institute of Physics.

Electronic Resource

1077-3118

AIP Digital Archive

Physics

A new, simplified process has been developed for fabricating submicron AlxGa1−xAs-GaAs heterostructure devices for low-temperature transport studies, with the advantage of gatability. This process utilizes electron beam lithography, photolithography, and wet etching techniques to laterally confine the two-dimensional electron gas, and possesses the unique feature that the metal etch mask for the electron beam defined narrow section is deposited directly on top of the heterostructure surface, allowing for use as a gate. Devices of lithographic widths from 0.4 to 2.0 μm have been successfully fabricated, where the 0.4 μm devices of both enhancement and depletion modes have been demonstrated to function down to 0.35 K in temperature.

Electronic Resource

1471-0528

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Objective To test whether maternal corticotrophin-releasing hormone levels are elevated in the mid–trimester for those women who subsequently had spontaneous preterm delivery and to assess the clinical utility of the measurement in the prediction of preterm delivery.Design A prospective observational study.Setting Department of Obstetrics and Gynaecology, Prince of Wales Hospital, Hong Kong.Population 1047 low risk pregnant women recruited at 15–20 weeks of gestation.Methods Venous samples were assayed for levels of corticotrophin-releasing hormone. The investigators responsible for the laboratory assay were blinded to the obstetric outcome.Main outcome measures Incidence of preterm, term and post-term pregnancies.Results Those who were delivered spontaneously at a preterm gestational age (before 34 weeks) had significantly higher corticotrophin–releasing hormone levels in the mid–trimester, compared with those who were delivered at term or post–term. There was a trend towards lower corticotrophm–releasing hormone levels with more advanced gestational age at delivery. When the measurement of corticotrophin–releasing hormone was used to predict delivery before 34 weeks, the best cut off was 1.9 MoM, which produced a sensitivity of 72.7% and specificity of 78.4%. This translated to a positive predictive value of 3.6%, negative predlctive value of 99.6% and relative risk of 9.4 when the background prevalence of spontaneous preterm delivery before 34 weeks was 1.1%. The likelihood ratio was 3.4.Conclusions Mid-trimester maternal corticotrophin-releasing hormone levels are elevated in pregnancies destined to deliver preterm before 34 weeks. When used alone in a low risk population, the measurement has a low predictive power for preterm delivery. However, the likelihood ratio of 3.4 implies that in high risk populations the test may be considerably more valuable.

Electronic Resource

1471-0528

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Electronic Resource

1471-0528

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Electronic Resource

1471-0528

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

The normal distribution of birth weight in a Queensland population has been surveyed. A method of analysis is presented which allows for the influence of a number of factors that affect birth weight.

Electronic Resource