Disease of the gallbladder in patients with normal cholecystograms

Sodium amytal increased resting potential decreased and finally abolished action potentials and temporarily decreased input resistance of the neuron membrane. Simultaneously, the intracellular potassium content decreased, but sodium content was almost unchanged. These effects are suggested to be connected with changes in the membrane potassium permeability and with disturbances in the mechanisms of action potential generation.     

Soluble temporarily immobilised biocatalysts

High catalytic density, good catalytic stability, simple catalyst recovery and facilitated product up-grading are necessary requirements for the industrial application of biocatalysts such as enzymes and cells. These requirements can be met by using soluble immobilised biocatalysts. The biocatalysts are usually confined in space to one of two aqueous phases, both of which have high water content and therefore are biocompatible and non-toxic to biological material. The products are either evenly distributed among the phases or partitioned to one of the phases. Soluble immobilised biocatalysts are particularly useful for bioconversions of particulate or macromolecular substrates, as well as for bioconversions involving product inhibition. The feasibility of soluble immobilised biocatalysts has been studied on the enzymic saccharification of cellulose, glucose fermentation with Saccharomyces cerevisiae and the bioconversion of cellulose into ethanol.     

Prevalence of primary and secondary hypertension: studies in a random population sample

The prevalence of primary and secondary hypertension was determined in a random sample of 7455 Swedish men aged 47 to 54 years. Three hundred and sizty-one men were undergoing treatment for hypertension. Seven hundred and ninety-eight men who had blood pressures above 175/115 mm Hg at preliminary screening were recalled for further blood pressure measurements. Those on treatment and all the untreated men whose blood pressures were still over 175/115 mm Hg then underwent extensive investigation for secondary hypertension. Renal parenchymal hypertension was found in 25 (3-6%) patients, renovascular hypertension in four (0-6%), and other forms of secondary hypertension in 11 (1-6%). The investigation led to surgical treatment in only two cases (0-3%). The low prevalence of secondary hypertension, especially surgically curable forms of hypertension, makes routine screening for these cases unnecessary, at least when patients with hypertension have been found at screening. These data must be taken into account in planning community control programmes in hypertension.     

Noncoherent detection of convolutionally encoded continuous phasemodulation

The authors consider the error probability at large signal-to-noise ratios of rate-1/2 convolutionally encoded CPFSK (continuous-phase frequency-shift keying) with an optimum noncoherent detector on an additive white Gaussian noise channel. The performance is given in terms of a parameter called the minimum squared normalized equivalent Euclidean distance which plays the same role mathematically as the minimum squared normalized Euclidean distance used for coherent detectors. It is shown that by introducing convolutional coding the error performance is significantly improved. The authors propose a decoding algorithm for these convolutionally encoded CPM schemes which is based on a limited tree search algorithm and uses the maximum-likelihood decision rule for noncoherent detection. Computer simulations show that the degradation in error performance compared to the performance of the optimum coherent Viterbi detector is less than 1 dB with a relatively simple noncoherent detector on an additive white Gaussian noise channel for most of the schemes considered     

20 Gbit/s optical time multiplexing with TJS GaAlAs lasers

Optical time multiplexing has been demonstrated using ultrashort optical pulses (30 ps) generated by direct modulation of TJS GaAlAs lasers. With the detection method used, an intensity correlator using second-harmonic generation in LiIO3, a bit rate of 20 Gbit/s was observed. However, the ultrashort optical pulses generated by the TJS lasers indicate that optical time multiplexing at 30 Gbit/s can be achieved.     

Electrical noise measurements on laser diodes for monitoring of optical feedback and mode hopping

By measuring the wideband electrical noise voltage at the diode terminal, several laser characteristics can be monitored entirely without optical equipment. The letter describes the application of electrical noise measurements to the study of longitudinal mode hopping and optical feedback-induced noise from, for example, optical fibres.     

Internet-Based Treatment for Insomnia: A Controlled Evaluation.

This study investigated the effects of an Internet-based intervention for insomnia. Participants who met criteria for insomnia (N = 109) were randomly assigned to either a cognitive-behavioral self-help treatment or a waiting list control condition. The 5-week intervention mainly consisted of sleep restriction, stimulus control, and cognitive restructuring. Sleep diary data were collected for 2 weeks at baseline and at posttreatment. The dropout rate was 24% (n = 28). Results showed statistically significant improvements in the treatment group on many outcome measures, including total sleep time, total wake time in bed, and sleep efficiency. However, improvements were also found in the control group. Overall, between-groups effect sizes were low, with the exception of the Beliefs and Attitudes About Sleep Scale (Cohen's d = .81). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

SC filter for RF sampling and downconversion with wideband image rejection

In this paper we present an SC filter for RF downconversion using the direct RF sampling and decimation technique. The circuit architecture is generic and it features high image rejection for wideband signals and good linearity. An SC implementation in 0.13μm CMOS suitable for an RF of 2.4 GHz and 20 MHz signal bandwidth is presented as a demonstrator. Simulation results obtained using Cadence Spectre simulation tools are included.     

On the effective constitutive properties of a thin adhesive layer loaded in peel

An experimental method to determine the complete stress-elongation relation for a structural adhesive loaded in peel is presented. Experiments are performed on the double cantilever beam specimen, which facilitates a more stable experimental set-up as compared with conventional methods like the butt-joint test. The method is based on the concept of equilibrium of the energetic forces acting on the specimen. Two sources of energetic forces are identified: the start of the adhesive layer and the positions of the two acting loads. By use of the concept of equilibrium of energetic forces, it is possible to measure the energy release rate of the adhesive layer instantaneously during an experiment. The complete stress-elongation relation is found to be the derivative of the energy release rate with respect to the elongation of the adhesive layer at its start. By this procedure, an effective property of the adhesive layer is measured. That is, the fields are assumed to be constant through the thickness of the layer and only vary along the layer. To investigate the validity of this approach, experiments are performed on five different groups of specimens with different dimensions. This leads to large variations in the length of the damage zone at the start of the adhesive layer. Four of the experimental groups are used to determine the stress-elongation relation. This is found to be independent of the geometry. For the remaining experimental group, the adherends deform plastically and simulations are performed with the stress-elongation relation determined from the four elastic groups. It is found that the relation cannot be used to accurately predict the behaviour of the experiments where the adherends deform plastically. This indicates that the stress-elongation relation has limited applicability.