Diode-pumped ytterbium-doped Sr5(PO4)3F laser performance

The performance of the first diode-pumped Yb³⁺-doped Sr ₅(PO₄)₃F (Yb:S-FAP) solid-state laser is discussed. An InGaAs diode array has been fabricated that has suitable specifications for pumping a 3×3×30 mm Yb:S-FAP rod. The saturation fluence for diode pumping was deduced to be 5.5 J/cm ² for the particular 2.8 kW peak power diode array utilized in our studies. This is 2.5× higher than the intrinsic 2.2 J/cm ² saturation fluence as is attributed to the 6.5 nm bandwidth of our diode pump array. The small signal gain is consistent with the previously measured emission cross section of 6.0×10^-20 cm², obtained from a narrowband-laser pumped gain experiment. Up to 1.7 J/cm³ of stored energy density was achieved in a 6×6×44 mm Yb:S-FAP amplifier rod. In a free running configuration, diode-pumped slope efficiencies up to 43% (laser output energy/absorbed pump energy) were observed with output energies up to ~0.5 J per 1 ms pulse. When the rod was mounted in a copper block for cooling, 13 W of average power was produced with power supply limited operation at 70 Hz with 500 μs pulses     

Probabilistic inference of multijoint movements, skeletal parameters and marker attachments from diverse motion capture data

This paper describes a comprehensive solution to the problem of reconstructing the multijoint movement trajectories of the human body from diverse motion capture data. The problem is formulated in a probabilistic framework so as to handle multiple and unavoidable sources of uncertainty: sensor noise, soft tissue deformation and marker slip, inaccurate marker placement and limb measurement, and missing data due to occlusions. All unknown quantities are treated as state variables even though some of them are constant. In this way, state estimation and system identification can be performed simultaneously, obtaining not only the most likely values but also the confidence intervals of the joint angles, skeletal parameters, and marker positions and orientations relative to the limb segments. The inference method is a Gauss-Newton generalization of the extended Kalman filter. It is adapted to the kinematic domain by expressing spatial rotations via quaternions and computing the sensor residuals and their Jacobians analytically. The ultimate goal of this project is to provide a reliable data analysis tool used in practice. The software implementation is available online.     

Modular Functionalization of Electrodes by Cross‐Coupling Reactions at Their Surfaces

Due to the increasing importance of modified electrodes for many applications in nanotechnology, including molecular electronics, bioelectronics, and sensors, there is a need to find ways to chemically attach suitable molecular films onto the electrodes. Combining the electroreduction of aryl diazonium salts with the Sonogashira cross‐coupling reaction, a new modular technique to modify electrodes is presented. The new technique allows a wide range of functional groups to be introduced onto electrode surfaces with high surface coverage by the functional subunit. Various organic subunits, including redox chromophores, are successfully attached to platinum electrodes. The corresponding films are characterized using cyclic voltammetry, X‐ray photoelectron spectroscopy, atomic force microscopy, and contact‐angle measurements. The electroreduction of diazonium salts is successfully achieved on a broad variety of conducting and semiconducting surfaces, which shows that the technique is applicable to a broad variety of substrates.     

Multiple sclerosis and measles: a study of cellular sensitization

Lymphocyte sensitization to measles has been studied in comparable groups of multiple sclerosis, other neurologic disease and normal subjects. The macrophage electrophoretic mobility test has been used. No difference between the three groups has been found, though there is a small group of children with obscure neurological disease which might well be multiple sclerosis and which fails to mount an adequate response to measles. The role of measles (and other banal infections) in aetiopathogenesis of multiple sclerosis is briefly discussed.     

Stability of testosterone and androstenedione in blood and plasma samples

In order to investigate the stability of testosterone (T) and androstenedione (Adione) in blood and plasma samples following study was undertaken. 1. Pooled blood samples were left unseparated at room temperature for varying time periods of up to 3 days before being centrifuged. Subsequent plasma T and Adione values measured by radioimmunoassay showed only small, insignificant variations. 2. Plasma, initially separated from the pooled blood sample, was left at room temperature for up to 24 h. There was no significant change in the levels of T and Adione measured over this period. There was also good correlation between steroid concentrations measured in blood and plasma. 3. T and Adione were measured in a pooled plasma sample after repeated freezing and thawing of the sample. All T values were well within the intraassay coefficient of variation; all Adione values were within the precision limits of the assay, although there was a considerable spread in individual values. It is concluded that the various handling procedures of blood or plasma have no significant effect on T and Adione levels.     

Rat intestinal brush border membrane peptidases. I. Solubilization, purification, and physicochemical properties of two different forms of the enzyme

Two brush border peptidases have been isolated from the particulate fraction of the rat intestinal mucosa and purified to homogeneity as judged by polyacrylamide gel electrophoresis, starch gel electrophoresis, isoelectric focusing, and double immunodiffusion. For convenience, the peptidases have been designated peptidase F (fast) and S (slow) on the basis of their anodic mobilities. The isoelectric point of peptidase F was 4.76 and of peptidase S, 5.10. Both enzymes are glycoproteins. The amino acid compositions of the two peptidases are similar. The same carbohydrates are found in both enzymes, but there are differences in the molar concentrations of individual sugars. Peptidase S has greater concentrations of mannose and galactose and of hexosamines than peptidase F, while sialic acid is slightly greater in peptidase F. Carbohydrate accounted for approximately 19% and 23% of the weight of peptidases F and S, respectively. Estimates of the molecular weights of both enzymes by gel filtration gave values of 280,000. Electrophoresis of the enzymes under denaturing conditions on sodium dodecyl sulfate polyacrylamide gels indicated that each enzyme is a dimer consisting of two subunits of equal molecular weight, 140,000.     

Chemotactic responses of normal human basophils to C5a and to lymphocyte-derived chemotactic factor

Peripheral blood basophils from normal human subjects responded chemotactically to the complement component C5a and also to the supernatant fluid from cultured human lymphocytes stimulated by mitogens or specific antigen. Basophil chemotactic factor (BCF) was detected in stimulated lymphocyte cultures within 24 hr and increased for the first 3 days. BCF was found after stimulation of lymphocytes by B or T cell mitogens as well as by specific antigen. The amount of BCF in culture fluids was independent of cell proliferation. Monocyte chemotactic factor (MCF) and BCF could not be separated from one another by Sephadex or DEAE chromatography. Both activities were eluted from Sephadex G-100 columns in a m.w. region of about 15,000 daltons and were found after ion exchange chromatography on DEAE in a peak eluted by 0.1 M NaCl. These findings suggest that mitogen or antigen-stimulated lymphocytes secrete a molecule that is chemotactic for both monocytes and basophils. Thus, in the absence of a basophil-specific chemotactic molecule, the preferential accumulation of basophils in certain types of delayed hypersensitivity skin reactions must be due to additional factors such as basophil chemotaxis augmentation factor.     

Spontaneous dissection of the internal carotid artery

The arteriographic diagnosis of spontaneous, nontraumatic dissection of the internal carotid artery was made in 19 patients and confirmed at operation in ten. The tapered narrowing beginning in or about the carotid bulb and ending at the bony canal was a consistent finding. Four patients had associated aneurysm formation. All but one patient developed an acute hemispheric neurologic deficit as the initial symptom. The deficit was transient in ten and prolonged in eight. The dissection occurred in the outer layers of the media. None of the surgical specimens showed atherosclerosis. Surgical methods of management included segmental resection and grafting, thrombectomy and intimectomy, dilation, and simple ligation. Considerable improvement of luminal diameter occurred in six of seven patients whose arteries were left undisturbed.     

Effect of charcoal-broiled beef on phenacetin metabolism in man

When charcoal-broiled beef was fed to human volunteers, who were then given phenacetin orally, the concentration of phenacetin in the plasma was lowered, but its half-life in the plasma was not changed. The data suggest that feeding charcoal-broiled beef enhances the metabolism of orally administered phenacetin in the intestine or during its first pass through the liver, or both.     

(Vinylaryloxy)acetic acids. A new class of diuretic agents. 3. ((2-Nitro-1-alkenyl)aryloxy)acetic acids

A series of [(2-nitro-1-alkenyl)aryloxy]acetic acids was synthesized and tested in dogs for saluretic and diuretic activity. A number of these compounds exhibit a high order of activity on iv or po administration; representative of these is (E)-[2,3-dichloro-4-(2-nitropropenyl)phenoxy]acetic acid (5). The most highly active compounds are qualitatively similar in action to [2,3-dichloro-4-(2-methylenebutyryl)phenoxylacetic acid (ethacrynic acid) in causing a prompt increase in the excretion of water and of sodium and chloride ions in approximately equimolar amounts but are three to five times as potent. Potassium ion excretion is increased but less markedly than sodium excretion.