Selective Liquid-Liquid Extraction of Thorium(IV) from Rare-Earth Element Mixtures.

One of the major challenges in processing rare-earth element (REE) materials arises from the large amounts of radioactive thorium (Th) that are often found within REE minerals, encouraging enhanced metal separation procedures. We report here a study aimed at developing improved systems for REE processing with the goal of efficient extraction of Th(IV) from acidic solution. A tripodal ligand, TRPN-CMPO-Ph, was prepared that utilizes carbamoylmethylphosphine oxide (CMPO) chelators tethered to a tris(3-aminopropyl)amine (TRPN) capping scaffold.

Crystal structure of a (carb-oxy-meth-yl)tri-ethyl-aza-nium bromide-2-(tri-ethyl-aza-n-ium-yl)acetate (1/1) hydrogen-bonded dimer.

The title compound, CHNO ·Br·CHNO, crystallizes as the bromide salt of a 50:50 mixture of (tri-ethyl-azaniumyl)-carb-oxy-lic acid and the zwitterionic (tri-ethyl-azaniumyl)-carboxyl-ate. The two organic entities are linked by a half-occupied bridging carb-oxy-lic acid hydrogen atom that is hydrogen-bonded to the carboxyl-ate group of the second mol-ecule. The tetra-lkyl-ammonium group adopts a nearly perfect tetra-hedral shape around the nitro-gen atom with bond lengths that agree with known values.

A Process for the Design and Development of Novel Bone Morphogenetic Protein-7 (BMP-7) Mimetics With an Example: THR-184.

Growth Factors have been evaluated as therapeutic targets for the treatment of a broad spectrum of diseases. Because they are proteins with pleiotropic effects, the quest to harness their beneficial effects has presented challenges. Most Growth Factors operate at the extracellular-receptor level and have natural feedback mechanisms that modulate their effects.

Characteristics of child sexual assault within a child advocacy center client population.

This descriptive study summarized data from a child advocacy center to illustrate how such information might be used to profile the scope and character of child sexual abuse (CSA) at the community level. This detailed information is not available from national or state data but is needed to understand the circumstances of the children receiving services and the type of care they may need. Variables included victim demographics, type of sexual abuse and relationship to the perpetrator, and the person to whom the victim was most likely to disclose their sexual assault.

A study of the dynamic properties of the human red blood cell membrane using quasi-elastic light-scattering spectroscopy.

A quasi-elastic light-scattering (QELS) microscope spectrometer was used to study the dynamic properties of the membrane/cytoskeleton of individual human red blood cells (RBCs). QELS is a spectroscopic technique that measures intensity fluctuations of laser light scattered from a sample. The intensity fluctuations were analyzed using power spectra and the intensity autocorrelation function, g(2)(tau), which was approximated with a single exponential.

A quasi-elastic light scattering study of smooth muscle myosin in the presence of ATP.

We have investigated the hydrodynamic properties of turkey gizzard smooth muscle myosin in solution using quasi-elastic light scattering (QELS). The effects of ionic strength (0.05-0.

Form birefringence of muscle.

We investigate the sensitivity of measurements of muscle birefringence to cross-bridge dynamics in the resting, active, and rigor states. The theory of form birefringence is reviewed, and an optical model is constructed for the form birefringence of muscle. Values for the parameters in the model are selected or deduced from the literature.

Quasi-elastic light scattering studies of membrane motion in single red blood cells.

Studies of red blood cells (RBCs) and RBC ghosts, using a quasi-elastic light scattering (QELS) microscope spectrometer, have identified the membrane as the primary source of the light scattering signal. This is the first report in which motion of the cell membrane has been demonstrated to be the primary source of the QELS signal from a cell. Cytoplasmic changes induced in the RBC by varying the osmotic strength of the medium were also detected using this technique.

Quasielastic light scattering microscope spectrometer.

We have developed a quasielastic light scattering microscope spectrometer from a commercially available instrument. The coherence requirements of microscope spectrometers have been examined, and our system performs in agreement with theory. Microscopic scattering volumes can be studied while still minimizing spatial averaging effects on the intensity autocorrelation function.

Erythrocyte age-fractionation using a Percoll-Renografin density gradient: application to autologous red cell antigen determinations in recently transfused patients.

A rapid technic for the age-fractionation of human erythrocytes into reticulocyte-enriched (young) red blood cells and reticulocyte-poor (old) red blood cells using an isopycnic density gradient centrifugation through Percoll-Renografin was evaluated for use in autologous red blood cell antigen determinations in multiply-transfused patients. The fractionation was demonstrated by statistically significant density-related changes in pyruvate kinase and acetylcholinesterase activities (P = 0.002 and 0.

Measurement of the translational diffusion constant of G-actin by photon correlation spectroscopy.

Photon correlation spectroscopic measurements on monomeric actin have yielded a translational diffusion constant of 8.13 X 10(-7) cm2 s-1 after correction for the contribution of the back-reflections of the main beam. This value corresponds to a sphere with a radius of 2.

Photon correlation spectroscopic study of the size distribution of phospholipid vesicles.

The dependence of phospholipid vesicle size on lipid composition is investigated by photon correlation spectroscopy. For each lipid composition prolonged ultracentrifugation was used to isolate a nearly uniform population of minimum-sized vesicles. The residual size variations in the samples were sufficient to cause polydispersity that made comparisons between samples difficult.

Histochemical demonstration of terminal deoxynucleotidyl transferase in leukemia.

White blood cells from 22 patients with leukemia and lymphoma were studied for the presence of terminal deoxynucleotidyl transferase with a peroxidase-antiperoxidase method. The enzyme was detected in leukemic cells of 5 patients with acute lymphoblastic leukemia and 1 patient with chronic myelogenous leukemia, whereas 16 patients with different forms of leukemia or lymphoma were negative for this enzyme. Comparative studies using a biochemical and an indirect immunofluorescence assay revealed complete concordance between these three methods.

Terminal deoxynucleotidyl transferase activity in neoplastic and nonneoplastic hematopoietic cells.

Terminal deoxynucleotidyl transferase activity was investigated by enzyme assay and (or) an indirect immunofluorescence method with specimens from 151 patients who had a variety of neoplastic and nonneoplastic conditions: leukemia, 62; non-Hodgkin's lymphoma, 36; Hodgkin's disease, seven; lymph nodes without neoplasms, 21; normal peripheral blood, 15; normal bone marrow, ten. Immunologic studies were done on samples from 82 of these patients. Increased terminal deoxynucleotidyl transferase activity was found by both methods in patients who had acute lymphoblastic leukemia and the lymphoid blast crisis of chronic myelocytic leukemia and by the immunofluorescence method in patients who had lymphoblastic lymphoma.

Quasi-elastic light-scattering studies of single skeletal muscle fibers.

Measurements were made of the intensity autocorrelation function, g(2)[tau], of light scattered from intact frog muscle fibers. During the tension plateau of an isometric tenanus, scattered field statistics were approximately Gaussian and intensity fluctuations were quasi-stationary. The half time, tau 1/2, for the decay of g(2)[tau] was typically 70 ms at a scattering angle of 30 degrees.

Dynamic light-scattering evidence for the flexibility of native muscle thin filaments.

We have obtained clear evidence for the flexibility of native scallop adductor thin filaments by studying the temperature and ionic strength dependence of the average decay constants obtained from intensity fluctuation spectroscopic (IFS) measurements. The low-angle (10-25 degrees ), average decay constants obtained from time autocorrelation functions of scattered light were independent of concentration (0.08-1.

Iterative Fourier approach for describing linear, multiple plane, coherent optical processors.

In this paper it is shown that the formal mathematical description of a quite general, multiplane, coherent, optical processor can always be reduced to an iterative Fourier transform and multiply procedure. In orderto write the system description in this manner, only suitable notational changes are needed. The principaladvantage of this alternate form is that more tractable models result for system synthesis.

Apodization filtering applied to a bandlimited optical Fourier transformer.

The basic Fourier optical transform operation that exists between the front and rear focal planes of a coherently illuminated lens is examined from the viewpoint of spatial bandlimiting. It is common to regard this relationship as exact in its application to optical data processors, but in reality, finite size lens and pupil functions impose spatial bandlimiting that smooths or broadens the fields in the transform domain. To reduce these effects, shaded apertures or apodizing filters are placed in the lens plane.

Bandlimiting effects in an optical Laplace transform computer.

Data processing in coherent optical systems has been limited to a large extent by operations involving spectrum manipulations through the Fourier transform. By appropriate modification of the Green function kernel of the Rayleigh-Sommerfeld diffraction integral, it should be possible to obtain transform relationships between the input and output of a coherent processor, other than the Fourier transform. Cutrona has suggested a possible implementation for a Laplace transformer but has apparently not attempted a physical realization [IRE Trans.