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H J Bernstein

Publications and source records attributed to H J Bernstein.

At least 19 recordsLinked to original sources
PubMed1994

Stimulus dose-titration in ECT: a 2-year clinical experience.

One hundred and thirty-four patients referred for electroconvulsive therapy (ECT) over a 2-year period underwent standardized stimulus dose-titration. No significant adverse events were associated with the dose-titration procedure. Our data demonstrate that seizure threshold increases with age (p = 0.0001) and is higher with bilateral electrode placement (p = 0.0001). Contrary to other studies, our data show the effect of gender is not statistically significant (p = 0.54). If consensus regarding optimal dosing strategies relative to seizure threshold can be achieved, dose-titration may be adopted as a clinically useful step in optimizing ECT technique.

Adult↗
PubMed1991

TV and ECT.

Explore the source record for details and available documents.

Depressive Disorder↗
PubMed1983

A Monte Carlo simulation of Compton scattering in positron emission tomography.

A Monte Carlo technique was used to simulate some of the important physical processes involved in the coincidence detection of gamma rays by a positron emission tomograph. The major effect considered here is the detection of Compton scattered gamma rays as coincidence counts. The Compton scattering of gamma rays in a H2O filled phantom was simulated using the Klein-Nishina cross section. Results obtained in the form of profiles of activity were compared to a model which represents scatter as the convolution of the true signal with an exponential.

Models, Theoretical↗
PubMed1979

Mechanisms of spectral shifts in lobster carotenoproteins. The resonance Raman spectra of ovoverdin and the crustacyanins.

Resonance Raman data have been used to elucidate the mechanisms of the absorption spectral shifts occurring for astaxanthin upon binding to the carotenoproteins, ovoverdin and alpha-,beta- and gamma-crustacyanins, from the lobster Homarus americanus. Although distinguishable on the basis of small differences in their resonance Raman spectra the binding sites of the crustacyanins, giving rise to lambdamax at 605 +/- 25 nm, are essentially the same. The large red shift in lambdamax for the crustacyanins compared to free astaxanthin (lambdamax 480 nm), is accounted for by a charge-polarisation mechanism in which charged groups and possibly hydrogen bonds in the binding site set up pi electron polarisation in the ligand. Several alternate mechanisms can be eliminated. Ovoverdin is found to consist of three polypeptide chains of molecular weight 105,000, 95,000 and 78,000 which are not linked by disulfide bridges. The visible absorption peaks of ovoverdin at 460 and 640 nm are shown to arise from two astaxanthin molecules each bound at a different site. The spectral characteristics of the 460 nm site suggest a rigid hydrophobic environment for astaxanthin, in which no charge-ligand interactions occur. The mechanism of the spectral shift in the 640 nm site is the same as in the crustacyanins, i.e. a charge-polarisation effect. Resonance Raman spectra of ovoverdin and the crustacyanins could be obtained in situ; they were identical to the spectra of the purified proteins showing that the carotenoid sites were unperturbed by protein isolation.

Animals↗
PubMed1978

Raman spectroscopic studies of biological membrane model systems: dietherlecithins.

Raman spectra are obtained for the multilayer dispersion of rac-1,2,dioctadec-9'-cis-enyl-glycero-3-phosphorylcholine (dietherlecithin) in excess water. The CH stretching region was studied as a function of temperature and indicates that the multilayer dispersions undergo a liquid crystal to the gel phase transition at--21 +/- 4 degrees C.

Membranes, Artificial↗
PubMed1976

Deuterated fatty acids as Raman spectroscopic probes of membrane structure.

Raman spectra are reported for the C-D stretching region of stearic acid-d35 bound in egg lecithin multilayers. The temperature dependence of the spectra shows that the linewidth of the C-D stretching bands is a sensitive and non-perturbative probe of membrane hydrocarbon chain conformation. The utility of this approach for studying lipid conformation in membranes containing a significant fraction of non-lipid component is discussed.

Deuterium↗
PubMed1976

The effect of sonication on the hydrocarbon chain conformation in model membrane systems: a Raman spectroscopic study.

Raman spectra are presented for egg lecithin above and below the gelliquid crystal phase transition, and several regions of the Raman spectrum are shown to be sensitive to conformational changes in the hydrocarbon chains. These regions are used to investigate the effect of sonication on the structure of egg lecithin and dipalmitoyl lecithin vesicles. Sonication of both egg lecithin above Tm, and dipalmitoyl lecithin above and below Tm produces no change in the relative population of trans and gauche isomers in any of the systems studied. Sonication does however appear to effect interchain interactions, a possible consequence of imperfect packing towards the center of the bilayers in vesicle systems.

Lasers↗
PubMed1976

Raman studies of the C-H and C-D stretching regions in stearic acid and some specifically deuterated derivatives.

Raman spectra of polycrystalline stearic acid-do, stearic acid-d35, 16:16-d2-18:18:18-d3-stearic acid, 18:18:18-d3-stearic acid, 17:17-d2-stearic acid, 17-d1-stearic acid, 16:16-d2-stearic acid, 12:12-d2-stearic acid and 12-d1-stearic acid have been obtained for the region containing the C-D and C-H stretching vibrations. Assignments of the methyl, methyl-d3, methylene, methylene-d2 and methylene-d1 stretching vibrations are discussed.

Deuterium↗