Modification of spontaneous emission of (CdSe)ZnS nanocrystals embedded in nanoimprinted photonic crystals

Highly luminescent (CdSe)ZnS nanocrystals, with band edge emission in the red region of the visible spectrum, were successfully synthesized and incorporated in a resist, namely mr-NIL 6000. The nanocomposite material was imprinted by using conventional nanoimprint lithography (NIL) process. We report on the fabrication and characterization of nanoimprinted photonic crystals in this new functional material. Experiments showed good imprint properties of the NC/polymer based material and that the surface nanostructuration improves the light extraction efficiency by over 2 compared to a nanoimprinted unpatterned surface.

Restoring melancholia in the classification of mood disorders

The present DSM criteria for major depression poorly identify samples for treatment selection, prognosis, and assessments of pathophysiology. Melancholia, in contrast, is a disorder with definable clinical signs that can be verified by laboratory tests and treatment response. It identifies more specific populations than the present system and deserves individual identification in psychiatric classification. Its re-introduction will refine diagnosis, prognosis, treatment selection, and studies of pathophysiology of a large segment of the psychiatrically ill.

Acoustoelasticity in soft solids: assessment of the nonlinear shear modulus with the acoustic radiation force

The assessment of viscoelastic properties of soft tissues is enjoying a growing interest in the field of medical imaging as pathologies are often correlated with a local change of stiffness. To date, advanced techniques in that field have been concentrating on the estimation of the second order elastic modulus (mu). In this paper, the nonlinear behavior of quasi-incompressible soft solids is investigated using the supersonic shear imaging technique based on the remote generation of polarized plane shear waves in tissues induced by the acoustic radiation force. Applying a theoretical approach of the strain energy in soft solid [Hamilton et al., J. Acoust. Soc. Am. 116, 41-44 (2004)], it is shown that the well-known acoustoelasticity experiment allowing the recovery of higher order elastic moduli can be greatly simplified. Experimentally, it requires measurements of the local speed of polarized plane shear waves in a statically and uniaxially stressed isotropic medium. These shear wave speed estimates are obtained by imaging the shear wave propagation in soft media with an ultrafast echographic scanner. In this situation, the uniaxial static stress induces anisotropy due to the nonlinear effects and results in a change of shear wave speed. Then the third order elastic modulus (A) is measured in agar-gelatin-based phantoms and polyvinyl alcohol based phantoms.

Antidepressant medication treatment failure does not predict lower remission with ECT for major depressive disorder: a report from the consortium for research in electroconvulsive therapy

OBJECTIVE

To test whether antidepressant medication treatment failure predicts differential remission with electroconvulsive therapy (ECT) in nonpsychotic unipolar depression.

METHOD

Depressed patients diagnosed with the Structured Clinical Interview for DSM-IV receiving ECT were assessed for medication use with the Antidepressant Treatment History Form (ATHF) (N = 345). Response to ECT was assessed with the 24-item Hamilton Rating Scale for Depression. Baseline medication treatment failure was analyzed as a possible predictor of remission status. Dates of study enrollment were from May 1997 to July 2004.

RESULTS

Resistance to antidepressant medication as assessed by the ATHF, either taken as a whole or for any individual class of medication, was not predictive of acute remission status with ECT.

CONCLUSION

Treatment failure with anti-depressant medication does not predict acute remission status with ECT for nonpsychotically depressed patients.

Theory of the time reversal cavity for electromagnetic fields

We derive a general expression of the electric dyadic Green function in a time-reversal cavity, based on vector diffraction theory in the frequency domain. Our theory gives a rigorous framework to time-reversal experiments using electromagnetic waves and suggests a methodology to design structures generating subwavelength focusing after time reversal.

DSM melancholic features are unreliable predictors of ECT response: a CORE publication

OBJECTIVE

To determine the relationship between baseline melancholic features with outcomes in patients with major depressive disorder referred for electroconvulsive therapy (ECT).

METHOD

In a multihospital (Consortium for Research in ECT) collaborative ECT study, SCID-1 interviews were obtained at study entry. Ratings of the 24-item Hamilton Rating Scale for Depression were obtained thrice weekly during the course of ECT, once during a subsequent treatment-free week, and periodically during 6-month continuation treatment with either bitemporal ECT or nortriptyline plus lithium (continuation pharmacotherapy).

RESULTS

The evaluable sample was severely ill with a mean 24-item Hamilton Rating Scale for Depression score of 35.2 (+/-6.9). Of 489 patients, 63.6% (311) met DSM-IV criteria for melancholic features. During acute ECT, 62.1% of those with melancholic features remitted, as compared with 78.7% for those without melancholic features (P = 0.002). During medication continuation treatment (continuation pharmacotherapy), relapse rates were higher for those with melancholic features than for those without these features. Conversely, with continuation ECT, the rate of relapse was lower for those with, compared with those without, melancholic features.

CONCLUSIONS

Ascertaining melancholic features by SCID-1 criteria does not identify depressed patients more likely to respond to ECT as had been anticipated from the literature. Melancholic features were associated with poorer treatment outcomes in acute ECT. Those with melancholic features were less likely to relapse with continuation ECT, but those with melancholic features were more likely to relapse with continuation pharmacotherapy. The limitations of the DSM-IV criteria for melancholia are discussed.

Compensating for bone interfaces and respiratory motion in high-intensity focused ultrasound

Bursts of focused ultrasound energy a thousand times more intense than diagnostic ultrasound have become a non-invasive option for treating cancer, from breast to prostate or uterine fibroid, during the last decade. Despite this progress, many issues still need to be addressed. First, the distortions caused by defocusing obstacles, such as the skull or ribs, on the ultrasonic therapeutic beam are still being investigated. Multi-element transducer technology must be used in order to achieve such transcranial or transcostal adaptive focusing. Second, the problem of motion artifacts, a key component in the treatment of abdominal lesions, has been shown significantly to influence the efficacy and treatment time. Though many methods have been proposed for the detection of organ motion, little work has been done to develop a comprehensive solution including motion tracking and feedback correction in real time. This paper is a review of the work achieved by authors in transcranial high-intensity focused ultrasound (HIFU), transcostal HIFU and motion compensated HIFU. For these three issues, the optimal solution can be reached using the same technology of multi-element transducers devices able to work both in transmit and receive modes.

Complaints of Loss of Personal Memories After Electroconvulsive Therapy: Evidence of a Somatoform Disorder?

This selective review considers the rare complaints of the loss of personal memories after successful courses of electroconvulsive therapy (ECT), which are best characterized as somatoform disorders, rather than as evidence of brain damage, thus warranting psychological treatment for such disorders.

Photoluminescence enhancement in nanoimprinted photonic crystals and coupled surface plasmons

A method to enhance the photoluminescence of dye chromophores-loaded by coupling the emission to surface plasmons in nanoimprinted photonic crystals is reported. A 9-fold enhancement in the spontaneous emission intensity of a rhodamine-doped polymer film is achieved on a silver layer due to surface plasmon excitation. By changing the surface plasmon frequency, this enhancement can be suppressed. When the polymer film is patterned by nanoimprint lithography with a twodimensional photonic crystal the photoluminescence intensity increases up to 27 times compared to unpatterned samples on a quartz substrate.

Resurrecting melancholia

OBJECTIVE

To define melancholia as a distinct mood disorder, identified by unremitting depressed mood, vegetative dysfunction, and psychomotor disturbances, verifiable by neuroendocrine tests, and treatable by electroconvulsive therapy and tricyclic antidepressants.

METHOD

A review of the literature of two centuries finds descriptions of severe mood disorders, either depression or mania or circular, defined as 'melancholia.' In the 1980 diagnostic revision (DSM-III), melancholia was relegated to a features specifier only.

RESULTS

DSM classification criteria develop heterogeneous patient samples that are neither guides to prognosis nor to treatment response, and confound studies of pathophysiology. Within the large population of mood disorders, a syndrome of melancholia is identifiable by specific behaviors, vegetative signs, and validated by neuroendocrine abnormalities (cortisolemia). Populations so identified are clinically homogeneous and have improved treatment responses. Patients meeting criteria for melancholia are now identified as psychotic depressed, geriatric depressed, postpartum psychosis, and pharmacotherapy resistant.

CONCLUSION

The review supports the establishment of melancholia by empirically derived criteria rather than by a checklist is an alternative to the major depression choice and offers an improved model for psychiatric classification.

Continuation electroconvulsive therapy vs pharmacotherapy for relapse prevention in major depression: a multisite study from the Consortium for Research in Electroconvulsive Therapy (CORE)

BACKGROUND

Although electroconvulsive therapy (ECT) has been shown to be extremely effective for the acute treatment of major depression, it has never been systematically assessed as a strategy for relapse prevention.

OBJECTIVE

To evaluate the comparative efficacy of continuation ECT (C-ECT) and the combination of lithium carbonate plus nortriptyline hydrochloride (C-Pharm) in the prevention of depressive relapse.

DESIGN

Multisite, randomized, parallel design, 6-month trial performed from 1997 to 2004.

SETTING

Five academic medical centers and their outpatient psychiatry clinics.

PATIENTS

Two hundred one patients with Structured Clinical Interview for DSM-IV-diagnosed unipolar depression who had remitted with a course of bilateral ECT.

INTERVENTIONS

Random assignment to 2 treatment groups receiving either C-ECT (10 treatments) or C-Pharm for 6 months.

MAIN OUTCOME MEASURE

Relapse of depression, compared between the C-ECT and C-Pharm groups.

RESULTS

In the C-ECT group, 37.1% experienced disease relapse, 46.1% continued to have disease remission at the study end, and 16.8% dropped out of the study. In the C-Pharm group, 31.6% experienced disease relapse, 46.3% continued to have disease remission, and 22.1% dropped out of the study. Both Kaplan-Meier and Cox proportional hazards regression analyses indicated no statistically significant differences in overall survival curves and time to relapse for the groups. Mean +/- SD time to relapse for the C-ECT group was 9.1 +/- 7.0 weeks compared with 6.7 +/- 4.6 weeks for the C-Pharm group (P = .13). Both groups had relapse proportions significantly lower than a historical placebo control from a similarly designed study.

CONCLUSIONS

Both C-ECT and C-Pharm were shown to be superior to a historical placebo control, but both had limited efficacy, with more than half of patients either experiencing disease relapse or dropping out of the study. Even more effective strategies for relapse prevention in mood disorders are urgently needed.

Gastrointestinal helminths in indigenous and exotic chickens in Vietnam: association of the intensity of infection with the Major Histocompatibility Complex

This study compared the prevalence and intensity of infections of helminths in 2 chicken breeds in Vietnam, the indigenous Ri and the exotic Luong Phuong. Also, possible correlations with the Major Histocompatibility Complex (MHC) were tested. The most prevalent helminths were Ascaridia galli, Heterakis beramporia, Tetrameres mothedai, Capillaria obsignata, Raillietina echinobothrida and Raillietina tetragona. Differences in prevalence and intensity of infection were found between the 2 breeds. Comparing the 2 groups of adult birds, Ri chickens were observed to have higher prevalence and infection intensities of several species of helminths, as well as a higher mean number of helminth species. In contrast, A. galli and C. obsignata were shown to be more prevalent in Luong Phuong chickens. Furthermore, an age-dependent difference was indicated in the group of Ri chickens in which the prevalence and the intensity of infection was higher for the adult than the young chickens for most helminths. The most notable exception was the significantly lower prevalence and intensities of A. galli in the group of adult chickens. In contrast, the prevalence and intensity were very similar in both age groups of Luong Phuong chickens. Using a genetic marker located in the MHC, a statistically significant correlation between several MHC haplotypes and the infection intensity of different helminth species was inferred. This is the first report of an association of MHC haplotype with the intensity of parasite infections in chickens.

Adaptive focusing for transcranial ultrasound imaging using dual arrays

Ultrasonic brain imaging remains difficult and limited because of the strong aberrating effects of the skull (absorption, diffusion and refraction of ultrasounds): high resolution transcranial imaging would require adaptive focusing techniques in order to correct the defocusing effect of the skull. In this paper, a noninvasive brain imaging device is presented. It is made of two identical linear arrays of 128 transducers located on each side of the skull. It is possible to separate the respective influence of the two bone windows on the path of an ultrasonic wave propagating from one array to the other, and thus estimate at each frequency the attenuation and phase shift locally induced by each bone window. The information obtained on attenuation and phase is used to correct the wave fronts that have to be sent through the skull in order to obtain a good focusing inside the skull. Compared to uncorrected wave fronts, the spatial shift of the focal spot is corrected, the width of the focal spot is reduced, and the sidelobes level is decreased up to 17 dB. Transcranial images of a phantom are presented and exhibit the improvement in image quality provided by this new noninvasive adaptive focusing method.