A novel compact and lightweight patient-mounted MRI-compatible robot has been designed for MRI image-guided interventions. This robot is intended to enable MRI-guided needle placement as done in ...shoulder arthrography. The robot could make needle placement more accurate and simplify the current workflow by converting the traditional two-stage arthrography procedure (fluoroscopy-guided needle insertion followed by a diagnostic MRI scan) to a one-stage procedure (streamlined workflow all in MRI suite). The robot has 4 degrees of freedom (DOF), two for orientation of the needle and two for needle positioning. The mechanical design was based on several criteria including rigidity, MRI compatibility, compact design, sterilizability, and adjustability. The proposed workflow is discussed and initial MRI compatibility experiments are presented. The results show that artifacts in the region of interest are minimal and that MRI images of the shoulder were not adversely affected by placing the robot on a human volunteer.
We have developed a strategy for the easy fabrication of quantum devices on AlGaAs/GaAs heterostructures featuring gates insulated from the heterostructure surface by a thin oxide layer deposited by ...atomic layer deposition. We will present the results of comparative studies of devices made with and without oxide-insulated gates to establish whether this leads to a significant enhancement in device stability and reduced gate hysteresis and noise.
We present preliminary measurements of resistively detected nuclear magnetic resonance (NMR) in GaAs-AlGaAs quantum point contacts (QPC). Nuclear spins in the host crystal are polarized through the ...hyperfine interaction with carriers near the QPC; this polarization can be detected via the four-terminal resistance and manipulated with a radio-frequency magnetic field.
Background: Previous studies have found a strong association between dissociation and obsessive-compulsive disorder (OCD). The purpose of the present study was to evaluate whether dissociation is a ...predictor of cognitive behavior therapy (CBT) outcome in patients with OCD. Methods: Fifty-two patients with OCD were assessed using the Dissociative Experience Scale (DES), the Yale-Brown Obsessive-Compulsive Scale and the Beck Depression Inventory. CBT lasted on average 9.5 weeks and included exposure therapy. Results: Patients who dropped out due to noncompliance had higher baseline DES scores and depression scores compared to the 43 patients (83%) who completed the study. Significant OCD symptom reduction at posttreatment was observed in study completers with a large effect size (d = 1.7). More severe OCD symptoms at posttreatment were associated with higher DES scores at baseline, and treatment nonresponders had significantly higher baseline DES scores compared to responders. These associations with outcome were mainly due to the DES subfactor absorption-imaginative involvement. In regression analyses, higher absorption-imaginative involvement scores at baseline predicted poorer CBT outcome, even after controlling for depressive symptoms, comorbid axis I disorders and concomitant psychotropic drugs. Conclusions: Results from this preliminary study suggest that higher levels of dissociation (particularly absorption-imaginative involvement) in patients with OCD might predict poorer CBT outcome. If our results can be replicated, treatment outcome might be improved by additional interventions for those patients with OCD who indicate high levels of dissociation, for example by using interventions aimed at improving coping with emotionally stressful situations.
The assessment of Quality of Life (QoL) is an important tool for elucidating target symptoms that are particularly bothersome to patients. The present study was designed to explore predictors of ...decreased QoL in obsessive-compulsive disorder (OCD) patients and to explore which aspects of QoL are most affected in OCD. Furthermore, the study investigated changes in QoL after treatment and the association between QoL change scores with symptomatic outcome. In line with prior research, it was expected that low QoL in OCD patients would be most pronounced for the emotional and social aspects of the construct.
Seventy-nine OCD patients were initially recruited. Patients were assessed with the SF-36 both before and after treatment. Norm values were derived from the general population to characterize status of impairment. OCD patients were contrasted with published SF-36 scores from 2 OCD samples as well as a newly recruited psychiatric and healthy control sample.
Correlations with QoL were most pronounced for depression severity and number of OCD symptoms. Apart from low social and emotional QoL in the majority of patients, a large subgroup also reported lower physical well-being. Decreased scores on this subscale were mainly associated with length of illness, depression, and number of compulsions. Overall, QoL was significantly improved in therapy responders relative to nonresponders.
The results largely correspond to previous findings showing that OCD patients share severely compromised well-being. Somewhat unexpected from previous research, QoL deficits were not restricted to emotional and social aspects of QoL but extended to somatic domains. The present results suggest that clinicians should thoroughly explore for depression as well as physical impairments in OCD patients, which, when present, may be additionally targeted to achieve comprehensive treatment success.
The feasibility of accurate monitoring a high voltage is investigated, which based on measuring a current through a capacitor, which is already installed in the grid. A current clamp based measuring ...system with high-resolution digitizer was developed. In order to adapt the system for different capacitors, the current clamp sensor is designed for a.c. currents in the rant of 150 μA to 12 A, while the acieved accuracy of the sensor is better than 0.1%. An implemented high quality analogue a.c. integrator processes the measuring signal to get a proportional scaled high voltage waveform at the sensors output. This feature is helpful for calculating the narmonics distortion in the HV grid. If a high-quality and well-known HV capacitor is available, accurate measurements within 0.5% for rms valuse and phase angles are possible in the HV grid under on-site conditions. Such accuracies are ususally more than adequate for monitoring purposes.
Purpose: Overexpression of the multidrug resistance proteins P-glycoprotein (Pgp), multidrug resistance protein (MRP-1), breast cancer
resistance protein (BCRP), and lung resistance protein (LRP) is ...associated with treatment failure in acute myeloid leukemia
(AML) and other malignancies. The Pgp modulator cyclosporin A has shown clinical efficacy in AML, whereas its analogue PSC-833
has not. Cyclosporin A is known to also modulate MRP-1, and we hypothesized that broad-spectrum multidrug resistance modulation
might contribute to its clinical efficacy.
Experimental Design: We studied the effects of cyclosporin A and PSC-833 on in vitro drug retention and cytotoxicity in resistant cell lines overexpressing Pgp, MRP-1, and BCRP and on nuclear-cytoplasmic drug
distribution and cytotoxicity in cells overexpressing LRP. Cellular drug content was assessed by flow cytometry and nuclear-cytoplasmic
drug distribution by confocal microscopy.
Results: Cyclosporin A enhanced retention of the substrate drug mitoxantrone in cells overexpressing Pgp (HL60/VCR), MRP-1 (HL60/ADR),
and BCRP (8226/MR20, HEK-293 482R) and increased cytotoxicity 6-, 4-, 4-, and 3-fold, respectively. Moreover, cyclosporin
A enhanced nuclear distribution of doxorubicin in 8226/MR20 cells, which also express LRP, and increased doxorubicin cytotoxicity
12-fold without an effect on cellular doxorubicin content, consistent with expression of wild-type BCRP, which does not efflux
doxorubicin. Cyclosporin A also enhanced nuclear doxorubicin distribution in a second cell line with LRP overexpression, HT1080/DR4.
PSC-833 enhanced mitoxantrone retention and cytotoxicity in cells overexpressing Pgp, but had no effect in cells overexpressing
MRP-1, BCRP, or LRP.
Conclusions: Cyclosporin A modulates Pgp, MRP-1, BCRP, and LRP, and this broad-spectrum activity may contribute to its clinical efficacy.
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