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Martin Goldstein

Publications and source records attributed to Martin Goldstein.

10 recordsLinked to original sources
PubMed2006

The Kauzmann paradox at constant volume.

The entropy of o-terphenyl in the liquid and crystalline state heated at constant volume in the range 250-310 K is calculated from calorimetric data at a pressure of 0.1 MPa and equation of state data. The specific heat is found to fit the same functional form as that at 0.1 MPa and leads to a vanishing of the excess entropy at essentially the same Kauzmann temperature as that under isobaric conditions. This adds confirmation to the significance of the Kauzmann extrapolation and contradicts the expectation that constant volume heating would show qualitatively different behavior from isobaric heating.

Journal Article↗
PubMed2006

Nanoconfinement and the glass transition: a cluster hypothesis.

It is suggested that the depression of the glass temperature in nanoconfined liquids and polymers may be explained by an effect of the confinement alone: specifically, confinement by hard walls creates an excluded volume effect that decreases the fraction of molecules organized in clusters. If we think of this fraction as a rough surrogate determining the fictive or structural temperature, then the confined liquid will have a higher fictive temperature than the bulk liquid at the same actual temperature. A computational method already used to study clusters may test the hypothesis.

Letter↗
PubMed2006

Increased brainstem volume in panic disorder: a voxel-based morphometric study.

Neurocircuitry models of panic disorder have hypothesized that the panic attack itself stems from loci in the brainstem including the ascending reticular system and respiratory and cardiovascular control centers. Voxel-based morphometry with acobian modulation was used to examine gray matter volume changes in 10 panic disorder patients and 23 healthy controls. The panic disorder patients had a relatively increased gray matter volume in the midbrain and rostral pons of the brainstem. Increased ventral hippocampal and decreased regional prefrontal cortex volumes were also noted at a lower significance threshold. This finding has implications for pathophysiologic models of panic disorder, and provides structural evidence for the role of the brainstem in neurocircuitry models of panic disorder.

Adult↗
PubMed2006

Veneer prep opinions.

Explore the source record for details and available documents.

Dental Prosthesis Design↗
PubMed2005

Comparing landscape calculations with calorimetric data on ortho-terphenyl, and the question of the configurational fraction of the excess entropy.

Mossa et al. [Phys. Rev. E 65, 041205 (2002)] have calculated the total and configurational entropies of supercooled ortho-terphenyl liquid using the potential-energy landscape formalism and a simplified model of the intermolecular potential. I show here that the agreement of their calculated configurational entropy with the experimental data depends on what is assumed about the configurational fraction of the excess entropy and its temperature dependence. In particular, if the configurational fraction is taken as 0.70 and independent of temperature the agreement is excellent; if a marked temperature dependence of that fraction inferred from calorimetric data is assumed the agreement is only fair at best. This marked temperature dependence of the configurational fraction also implies some implausible behavior of contributions to the excess entropy at the Kauzmann temperature, but no obvious reason for disregarding it presents itself.

Journal Article↗
PubMed2005

Fear-related activity in subgenual anterior cingulate differs between men and women.

Functional magnetic resonance imaging in association with an instructed fear/anticipatory anxiety paradigm was used to explore sex differences in the human fear response. During anticipation of mild electrodermal stimulation, women, as compared with men, demonstrated increased activity in the subgenual anterior cingulate cortex and functionally related regions of the insula and brainstem. The subgenual anterior cingulate cortex is a region critical for emotional control implicated in the pathogenesis of psychiatric disease. Present findings suggest a contributory neural substrate for the greater susceptibility of women to anxiety and affective disorders, and emphasize the importance of considering participant sex when designing and interpreting functional neuroimaging studies.

Adult↗
PubMed2005

Differential time courses and specificity of amygdala activity in posttraumatic stress disorder subjects and normal control subjects.

BACKGROUND: Previous neuroimaging studies have demonstrated exaggerated amygdala responses to negative stimuli in posttraumatic stress disorder (PTSD). The time course of this amygdala response is largely unstudied and is relevant to questions of habituation and sensitization in PTSD exposure therapy. METHODS: We applied blood oxygen level dependent functional magnetic resonance imaging and statistical parametric mapping to study amygdala responses to trauma-related and nontrauma-related emotional words in sexual/physical abuse PTSD and normal control subjects. We examined the time course of this response by separate analysis of early and late epochs. RESULTS: PTSD versus normal control subjects have a relatively increased initial amygdala response to trauma-related negative, but not nontrauma-related negative, versus neutral stimuli. Patients also fail to show the normal patterns of sensitization and habituation to different categories of negative stimuli. These findings correlate with measured PTSD symptom severity. CONCLUSIONS: Our results demonstrate differential time courses and specificity of amygdala response to emotional and control stimuli in PTSD and normal control subjects. This has implications for pathophysiologic models of PTSD and treatment response. The results also extend previous neuroimaging studies demonstrating relatively increased amygdala response in PTSD and expand these results to a largely female patient population probed with emotionally valenced words.

Adolescent↗
PubMed2005

High incidence of vaginal mesh extrusion using the intravaginal slingplasty sling.

PURPOSE: The intravaginal slingplasty (IVS) is a tension-free vaginal tape variant that uses a multi-filament polypropylene tape to support the mid urethra for the treatment of female stress urinary incontinence. Numerous cases of defective vaginal wound healing have been described in the international urogynecological literature. We describe our experience of vaginal mesh extrusion using the IVS sling. MATERIALS AND METHODS: A total of 35 patients underwent suburethral sling procedures for anatomical stress urinary incontinence using the IVS system from November 2002 to September 2003. A retrospective chart review was performed to retrieve data on safety and efficacy, complications and outcomes using this product. RESULTS: Six patients (17%) to date have presented with defective vaginal healing manifested by extrusion of the sling material. Mean time to presenting symptoms was 9 months (range 2 to 15). All patients required surgical removal of the sling material. No urethral erosions were noted. CONCLUSIONS: Our experience suggests that the IVS sling system, which uses a multi-filament polypropylene suburethral mesh, incurs an unacceptably high rate of defective vaginal wound healing and mesh extrusion.

Aged↗
PubMedDate not supplied

Coalescence of psychiatry, neurology, and neuropsychology: from theory to practice.

In a climate of renewed interest in the synergy between neurology and psychiatry, practitioners are increasingly recognizing the importance of exchange and collaboration between these two disciplines. However, there are few working models of interdisciplinary teams that freely share expertise in real time, while providing clinical and academic training to future physicians who specialize in the central nervous system. Over the past 11 years, the McLean Hospital Neuropsychiatry and Behavioral Neurology service has provided proof-of-principle for such collaboration, demonstrating that a team comprising psychiatrists, neurologists, and neuropsychologists can function effectively as a unit while maintaining the autonomy of these three disciplines and also synthesizing their combined knowledge. In addition to delivering enhanced patient care and promoting medical research, this clinical service has provided enriched cross-specialty training for fellows, residents, and medical students. The practical functioning of the team is described, and case vignettes are presented to illustrate the team's collaborative synergism in practice.

Adult↗