1,206 research outputs found
I. PHOTOTITRIMETRIC DETERMINATION OF SULFHYDRYL COMPOUNDS WITH O-HYDROXYMERCURIBENZOIC ACID USING DITHIOFLUORESCEIN AS AN INDICATOR. II. PURIFICATION AND PARTIAL CHARACTERIZATION OF CYSTEINE-GLUTAMATE TRANSAMINASE FROM RAT LIVER.
Source: Dissertation Abstracts International, Volume: 38-04, Section: B, page: 1691. Thesis (Ph.D.)--University of Windsor (Canada), 1977
Microchip implants for humans as unique identifiers: a case study on VeriChip
Microchip implants for humans are not new. The installation of pacemakers in humans and a great number of other medical innovations for prosthesis are now considered straightforward procedures. Today we have even realised the potential for microchip implants to be embedded inside the body of humans for the purpose of acting as unique lifetime identifiers (ULI). Tiny radiofrequency identification (RFID) devices are now being utilised to store a unique 16-digit identification number
Resource synergy : improving the discovery of quality resources to support and information-dense learning environment
Phonon lasing from optical frequency comb illumination of a trapped ion
An atomic transition can be addressed by a single tooth of an optical
frequency comb if the excited state lifetime () is significantly longer
than the pulse repetition period (). In the crossover regime
between fully-resolved and unresolved comb teeth (), we observe Doppler cooling of a pre-cooled trapped atomic ion
by a single tooth of a frequency-doubled optical frequency comb. We find that
for initially hot ions, a multi-tooth effect gives rise to lasing of the ion's
harmonic motion in the trap, verified by acoustic injection locking. The gain
saturation of this phonon laser action leads to a comb of steady-state
oscillation amplitudes, allowing hot ions to be loaded directly into the trap
and laser cooled to crystallization despite the presence of hundreds of
blue-detuned teeth.Comment: 5 pages, 4 figure
An Ultra-Sensitive Electrochemical Enzyme Immunoassay for Thyroid Stimulating Hormone in Human Serum
A sensitive heterogeneous electrochemical enzyme immunoassay has been developed for thyroid stimulating hormone (TSH) by modifying a commercially available two-site immunoenzymometric assay. p-Aminophenyl phosphate (PAPP) was used as the substrate of alkaline phosphatase, and hydrolysed to p-aminophenol (PAP). The amount of PAP produced from the assay was proportional to the amount of TSH in the sample. Detection of PAP was done by oxidative amperometry in a flow injection system. The working electrode was a glassy carbon electrode whose potential was held at +325 mV (vs Ag/AgCl). The amperometric detection of PAP required only 1 μl of sample (the range of linearity: 50.0 fmol-100 pmol PAP, the limit of detection: 10.9 fmol PAP). Intra-assay precision over the assay range of linearity (0.02–60 mIU l−1 or 0.02–60 pIU TSH) showed a maximum RSD of 8.0%, and a low detection limit of 0.01 mIU l−1 or 0.01 pIU TSH. The study also indicates that this two-site electrochemical enzyme immunoassay correlates well with the Bio-Rad\u27s immunoradiometric assay currently used in our medical center (r = 0.992, slope = 1.53, n = 43) and a highly sensitive immunochemiluminometric assay in the Nichols Institute (r = 0.986, slope = 0.499, n = 23)
Cyclone: A close air support aircraft for tomorrow
To meet the threat of the battlefield of the future, the U.S. ground forces will require reliable air support. To provide this support, future aircrews demand a versatile close air support aircraft capable of delivering ordinance during the day, night, or in adverse weather with pin-point accuracy. The Cyclone aircraft meets these requirements, packing the 'punch' necessary to clear the way for effective ground operations. Possessing anti-armor, missile, and precision bombing capability, the Cyclone will counter the threat into the 21st Century. Here, it is shown that the Cyclone is a realistic, economical answer to the demand for a capable close air support aircraft
The African Lungfish (\u3cem\u3eProtopterus dolloi\u3c/em\u3e): Ionoregulation and Osmoregulation in a Fish out of Water
Although urea production and metabolism in lungish have been thoroughly studied, we have little knowledge of how internal osmotic and electrolyte balance are controlled during estivation or in water. We tested the hypothesis that, compared with the body surface of teleosts, the slender African lungfish (Protopterus dolloi) body surface was relatively impermeable to water, Na+ and Cl- due to its greatly reduced gills. Accordingly, we measured the tritiated water (3H-H2O) flux in P. dolloi in water and during air exposure. In water, 3H-H2O efflux was comparable with the lowest measurements reported in freshwater teleosts, with a rate constant (K) of 17.6% body water h-1. Unidirectional ion fluxes, measured using 22Na+ and 36Cl-, indicated that Na+ and Cl- influx was more than 90% lower than values reported in most freshwater teleosts. During air exposure, a cocoon formed within 1 wk that completely covered the dorsolateral body surface. However, there were no disturbances to blood osmotic or ion (Na+, Cl-) balance, despite seven- to eightfold increases in plasma urea after 20 wk. Up to 13-fold increases in muscle urea (on a dry-weight basis) were the likely explanation for the 56% increase in muscle water content observed after 20 wk of air exposure. The possibility that muscle acted as a “water reservoir” during air exposure was supported by the 20% decline in body mass observed during subsequent reimmersion in water. This decline in body mass was equivalent to 28 mL water in a 100-g animal and was very close to the calculated net water gain (approximately 32 mL) observed during the 20-wk period of air exposure. Tritiated water and unidirectional ion fluxes on air-exposed lungfish revealed that the majority of water and ion exchange was via the ventral body surface at rates that were initially similar to aquatic rates. The 3H-H2O flux declined over time but increased upon reimmersion. We conclude that the slender lungfish body surface, including the gills, has relatively low permeability to water and ions but that the ventral surface is an important site of osmoregulation and ionoregulation. We further propose that an amphibian-like combination of ventral skin water and ion permeability, plus internal urea accumulation during air exposure, allows P. dolloi to extract water from its surroundings and to store water in the muscle when the water supply becomes limited
- …