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At least 127 records · Page 7Linked to original sources
PubMed1998

Meeting the expectations of chronic tinnitus patients: comparison of a structured group therapy program for tinnitus management with a problem-solving group.

Two different group treatments were evaluated in 144 in-patients suffering from impairment due to chronic tinnitus. A tinnitus management therapy (TMT) was developed using principles of cognitive-behavioral therapy and compared with problem solving group therapy. Self-ratings were used to evaluate the help patients found in dealing with life problems and tinnitus as well as the degree to which they felt they were being properly treated and taken seriously. Patients showed significantly more satisfaction with the TMT group and evaluated the help they found in coping with tinnitus and life problems significantly higher. Thus, in the light of unsatisfactory medical solutions and the poor acceptance of some psychological treatments for tinnitus, TMT appears to be an acceptable and helpful treatment program.

Adaptation, Psychological↗
PubMed2000

Comparison of 2D fingerprint types and hierarchy level selection methods for structural grouping using Ward's clustering

Four different two-dimensional fingerprint types (MACCS, Unity, BCI, and Daylight) and nine methods of selecting optimal cluster levels from the output of a hierarchical clustering algorithm were evaluated for their ability to select clusters that represent chemical series present in some typical examples of chemical compound data sets. The methods were evaluated using a Ward's clustering algorithm on subsets of the publicly available National Cancer Institute HIV data set, as well as with compounds from our corporate data set. We make a number of observations and recommendations about the choice of fingerprint type and cluster level selection methods for use in this type of clustering

Journal Article↗
PubMed2002

Trigonal bipyramidal geometry and tridentate coordination mode of the tripod in FeCl(2) complexes with tris(2-pyridylmethyl)amine derivatives bis-alpha-substituted with bulky groups. structures and spectroscopic comparative studies.

A series of dichloroferrous complexes with ligands derived from the tris(2-pyridylmethyl)amine tripod has been prepared and characterized. The X-ray crystal structures of the complexes [bis(2-bromo-6-pyridylmethyl)(2-pyridylmethyl)amine]Fe(II)Cl(2) ((Br(2)TPA)Fe(II)Cl(2)) and [bis(2-phenyl-6-pyridylmethyl)(2-pyridylmethyl)amine]Fe(II)Cl(2), ((Ph(2)TPA)Fe(II)Cl(2)) are reported. In these complexes, the tripod coordinates in the tridentate mode, with a substituted pyridyl arm dangling away from the metal. Both complexes have a trigonal bipyramidal iron center with two equatorial chloride ions. Their crystal structures are compared with those of the [tris(2-pyridylmethyl)amine]Fe(II)Cl(2) and [(2-bromo-6-pyridylmethyl)bis(2-pyridylmethyl)amine]Fe(II)Cl(2) complexes ((TPA)Fe(II)Cl(2) and (BrTPA)Fe(II)Cl(2), respectively) in which the ligand coordinates in the tetradentate mode. For all complexes, the metal to ligand distances are systematically above the value of 2.0 A, and (1)H NMR displays paramagnetically shifted resonances with short relaxation times. This indicates that the iron is in a high-spin state. Electric conductivity measurements show that, for all complexes, the measured values lie within the same range, significantly below those expected for ionic complexes. Together with the analysis of the UV-visible and NMR data, this strongly suggests that the coordination mode of the tripod is retained in solution.

Chlorides↗
PubMed2005

Time-resolved EPR studies of main chain radicals from acrylic polymers. Effects of tacticity, solvent, and side group structure on chain stiffness.

Main chain polymeric radicals from several acrylic polymers, produced by laser flash photolysis at 248 nm in liquid solution, have been studied using direct detection time-resolved electron paramagnetic resonance (TREPR) spectroscopy at 9.5 GHz. Highly isotactic poly(methyl methacrylate) (i-PMMA) shows a sharp, well-resolved spectrum at about 95 degrees C. Using synthetic methodology to disrupt the tacticity of i-PMMA, we observed different fast-motion hyperfine coupling constants for the main chain radicals. By raising the temperature of observation, we returned the coupling constants to the same value as those in the highly isotactic sample. This result is related qualitatively to the degree of stiffness of the polymer chains as a function of tacticity. The concept is tested further by comparison to two other acrylic polymers with bulky side chains: poly(fluorooctyl methacrylate) (PFOMA) and poly(adamantyl methacrylate) (PAMA), whose main chain radicals show significant line broadening even at 110 degrees C. Solvent effects on both spectral appearance (the alternating line-width effect) and kinetic decays (attributed to T1 relaxation) are also presented and discussed in terms of main chain conformational motion.

Journal Article↗
PubMed2004

LZnX complexes of tripodal ligands with intramolecular RN-H hydrogen bonding groups: structural implications of a hydrogen bonding cavity, and of X/R in the hydrogen bonding geometry/strength.

Tripodal ligands N(CH2Py)3-n(CH2Py-6-NHR)n(R=H, n=1-3 L1-3, n=0 tpa; R=CH2tBu, n=1-3 L'1-3) are used to investigate the effect of different hydrogen bonding microenvironments on structural features of their LZnX complexes (X=Cl-, NO3-, OH-). The X-ray structures of [(L2)Zn(Cl)](BPh4)2.0.5(H2O.CH3CN), [(L3)Zn(Cl)](BPh4)3.CH3CN, [(L'1)Zn(Cl)](BPh4) 1', [(L'2)Zn(Cl)](BPh4)2'.CH3OH, and [(L'3)Zn(Cl)](BPh4)3' have been determined and exhibit trigonal bipyramidal geometries with intramolecular (internal) N-HCl-Zn hydrogen bonds. The structure of [(L'2)Zn(ONO2)]NO3 4'.H2O with two internal N-HO-Zn hydrogen bonds has also been determined. The axial Zn-Cl distance lengthens from 2.275 A in [(tpa)Zn(Cl)](BPh4) to 2.280-2.347 A in 1-3, 1'-3'. Notably, the average Zn-N(py) distance is also progressively lengthened from 2.069 A in [(tpa)Zn(Cl)](BPh4) to 2.159 and 2.182 A in the triply hydrogen bonding cavity of 3 and 3', respectively. Lengthening of the Zn-Cl and Zn-N(py) bonds is accompanied by a progressive shortening of the trans Zn-N bond from 2.271 A in [(tpa)Zn(Cl)](BPh4) to 2.115 A in 3 (2.113 A in 3'). As a result of the triply hydrogen bonding microenvironment the Zn-Cl and Zn-N(py) distances of 3 are at the upper end of the range observed for axial Zn-Cl bonds, whereas the axial Zn-N distance is one of shortest among N4 ligands that induce a trigonal bipyramidal geometry. Despite the rigidity of these tripodal ligands, the geometry of the intramolecular RN-HX-Zn hydrogen bonds (X=Cl-, OH-, NO3-) is strongly dependent on the nature of X, however, on average, similar for R=H, CH2tBu.

Journal Article↗
PubMed1978

Mathematical theory of group selection: Structure of group selection in founder populations determined from convexity of the extinction operator.

Genetic analysis for group selection is developed for the case of a biallelic locus (A, a) undergoing group selection of founder populations only. By contrast to R. Levins"E = E(x) models, extinction now depends on genetics at the propagule stage but acts uniformly on larger populations. Biological evidence supports this hypothesis, which also allows mathematical treatment at once simpler and biologically more general than the Fokker-Planck partial differential equation formalism adopted by Levins. It is presently possible to handle cytogenetics of both diploid and haplodiploid type. The model is set up as a quasideterministic recursion in the 5-simplex Sigma(5), collapsing both drift and mendelian selection effects into a single parameter u, which is a Fisher-Kimura-Ohta fixation probability. In the analysis, it is shown that the stability of the fixed points is determined by the convexity of the extinction operator acting on propagules, assumed to be of size 2.THUS, [FORMULA: see text] in which E(1) and E(3) are extinction probabilities for phenotypically uniform founder populations and E(2) is the corresponding probability for founder populations of mixed phenotype. Further parameter regions are defined where fixation of the group-selected gene is globally stable, and this is still possible even when extinction pressure acting on carrying capacity populations becomes weak relative to a fixed mendelian selection strength.

Journal Article↗
PubMed1983

Structured group treatment for sexually abused children.

The author provides a model for the group treatment of sexually abused children. Eight treatment themes and various techniques of intervention are presented, and the model's applications to other methods of treatment and groups of sexually abused clients are described.

Arkansas↗
PubMed2005

Structural group classification technique based on regional fMRI BOLD responses.

This paper presents a new multigroup classification method based on subtle differences in regional brain activity during the completion of a functional magnetic resonance imaging (fMRI) challenge paradigm. Classification is performed based on features derived from BOLD time intensity curves in selected regions of interest (ROI). For each ROI, a mean time intensity curve [called mean regional response (MRR)] is calculated from realigned and normalized datasets. The overall subject performance is characterized with a vector of features obtained using nonlinear modeling of all subject's MRRs with a mixture of time shifted Gaussian functions. The classification is performed in the reduced-dimension optimal discrimination space, obtained through canonical transformations of original feature space. In order to demonstrate feasibility of the proposed method, classification of three groups of subjects is presented. The three groups are defined as heavy marijuana smokers after 24 hours of abstinence, heavy marijuana smokers after 28 days of abstinence, and healthy nonusing controls. The proposed method can be useful as an analytic tool for the discrimination of different groups of subjects based on temporal features of functional magnetic resonance imaging activation.

Adult↗