Enzymic differentiation between curds of heated and raw milk. I. milk alkaline phosphatase

Alkaline phosphatase, which is present in curds made from raw milk as well as from boiled milk, does not serve to differentiate them. It was found that incubation time or acidity (lactic acid equivalent of curd acidity incubated aseptically with heated milk) does not revive heat-denatured phosphatase. The reappearance was found to be due to phosphatase of microbial origin; it was not a case of reactivation of the denatured enzyme. Low intensity, but increasing slowly, of the activity of regenerated phosphatase in curd (permeability of the microbial cells to the testing reagents is probably limiting in the rate of reaction), presence of the enzyme in the sonicated cells of curd-forming microflora and absence of activity in the supernatant of the growth medium suggest that the formed enzyme is an intracellular one.     

Interface effects in YBCO/(Y-Pr)BCO multilayers, and the dimensionality of high-Tc superconductivity

Measurements on YBCO/(Y-Pr)BCO trilayers show that the depression of the transition temperature in ultrathin YBCO is accompanied by a decrease in the conductance of the layers adjacent to the interfaces. The lowering of the conductance seems to be primarily the result of charge transfer across the interfaces, and perhaps to some extent also of defects. The intrinsic properties of YBCO seem to change little or not at all as the thickness decreases from bulk down to that of a single unit cell.     

Phase equilibria in the system BaO-CeO2

The phase equilibrium relationships in the binary system BaO-CeO₂ have been investigated by thermal analysis, metallographic and X-ray diffraction methods. The system is characterised by the existence of only one compound, namely, BaCeO₃ which is found to melt incongruently at 1480±5°C with formation of solid CeO₂ and a liquid. A eutectic is found to occur between BaO and BaCeO₃ at 46±0.5 mol% CeO₂ and its melting point was determined as 1440±5°C. A narrow solid solubility range of BaO in BaCeO₃ exists but no solid solubility of BaCeO₃ in either BaO or CeO₂ was detected.     

Equivalent electrical representation of the sweat layer and gain compensation of the EMG amplifier

The sweat layer, formed on the surface of the skin, causes a partial short-circuit of the surface electrodes in an electromyographic (EMG) channel. As a result, the effective input impedance of the channel varies at random and, along with the impedance, the output voltage varies. In this note, the sweat layer has been represented as a variable resistance connected across the input stage of the EMG channel and the effect is analyzed. It has also been shown that the sweat layer's equivalent resistance can also be used for the continuous and automatic gain compensation of the EMG amplifier.     

Effect of heat treatment on electron traps in n-type GaAs

Annealing of bulk and vapor phase epitaxial (VPE) n-type GaAs at about 600°C for one hour in an apparatus of fused quartz (GE 204 or vitrosil) is seen to cause considerable reduction in the free electron concentration (N_S) and the commonly observed 0.85 eV electron traps (N_T) in these materials. Heating at elevated temperatures in the same environment causes an n-type sample to convert to p-type. The reduction in N_S and N_T is found to be considerably smaller for comparable heat treatments in a vacuum system free from quartz. It is suggested that the observed reduction is caused by in-diffusion of impurities like Cu and Li which are present in the types of quartz used in the experiments.     

Fast track thrombolysis in acute myocardial infarction: a quality improvement project

To understand the clinical efficacy of traditional anti-rheumatic herbal medicines on acute and severe arthritis or immune diseases, four herbal formulas and one herb were tested in vitro to determine their effects on prostaglandin E2 (PGE2) and interleukin 2 (IL2). Peripheral blood mononuclear cells from healthy subjects were incubated with different concentrations of four herbal formulas including Shaur Yau Gan Tsao Tang (SYGTT), Shang Jong Shiah Tong Yong Tong Feng Wan (SJSTY), Shu Jin Lih An Saan (SJLAS), Ma Shing Yih Gan Tang (MSYGT) and one herb, Tripterygium wilfordii (T2) with and without mitogen stimulation. PGE2 and IL2 from culture supernatant were measured by enzyme immunoassay. The results showed that SYGTT, SJSTY, SJLAS at concentration of 100 microg and MSYGT at 500 microg/ml can significantly inhibit PGE2 release (P < 0.05) from mononuclear cells. However, T2 at 2 microg/ml expressed the same response. For the inhibition of IL2, the concentration of SYGTT, SJSTY and SJLAS must exceed 100 symbol microg/ml. MSYGT failed to inhibit IL2 at even concentrations of 500 microg/ml but T2 at a very low concentration (0.6 microg/ml) could strongly inhibit it. The findings suggest that the majority of traditional anti-rheumatic herbal formulas or herbs, except for T2, should not be used to treat acute and critical arthritis or immune diseases.     

Reversibility with sodium bicarbonate of styrene maleic anhydride, an intravasal injectable contraceptive, in male rats

PURPOSE: Patients who use topical ophthalmic medications and wear soft contact lenses must remove their lenses before drop instillation to prevent absorption of the medication into the lenses. No previous study has examined how long such a patient should wait before reinserting their lenses. This study was designed to test the hypothesis that waiting 5 minutes before reinsertion of lenses would be sufficient to reduce absorption to a level below what is needed to produce a physiological response. METHODS: Naphcon-A was used as the test solution and pupillary dilation was the physiological response measured. The amount of benzalkonium chloride (BAC) extracted from the lenses was also measured. Twenty-three subjects, none of whom had any significant ocular or systemic abnormalities nor showed pupillary dilation to directly applied Naphcon-A, completed this 3-week study. The study used a 2-period crossover design with a 1-week screening phase. Results were analyzed with a repeated-measure analysis of variance. RESULTS: The pupils averaged 0.316 mm larger when subjects instilled Naphcon-A with lenses in place as compared to when dosing with lenses removed for 5 minutes (P = 0.0008). Nine of 23 subjects showed pupillary dilation greater than 0.5 mm when dosing with lenses in place as compared to none when lenses were removed for 5 minutes. Significantly (P < 0.01) more BAC was extracted from lenses that had been worn during dosing than from lenses removed for 5 minutes (0.9 microgram/lens as compared to no detectible amount). CONCLUSION: Removing soft contact lenses for 5 minutes was sufficient to prevent absorption of clinically significant amounts of Naphcon-A into the lenses.     

Amorphous hydrogenated silicon films prepared from a glowdischarge

From a detailed study of electrical and optical properties of amorphous hydrogenated silicon prepared from a mixture of 10% silane and 90% hydrogen, it is shown that the properties of the films compare favourably with the best reported results on those prepared from 100% silane.