3,209 research outputs found
Point-of-Care Ultrasound Assists in Rapid Diagnosis of T-cell Lymphoblastic Lymphoma in a Young Boy.
T-cell lymphoblastic lymphoma (T-cell LBL) is an uncommon diagnosis for acute dyspnea in pediatric emergencies. This case details a 13-year-old boy presenting to the ED with dyspnea, who was diagnosed with T-cell LBL. It was a unique presentation in which there was no obvious mediastinal mass on the examination or primary imaging. As a safe and cost-effective modality for a patient that was too unstable to transfer to the radiology department for computed tomography, point-of-care ultrasound (POCUS) was useful in the patient\u27s rapid assessment for suspected pericardial and pleural effusion. This case highlights the advantage of early utilization of POCUS for pediatric patients with dyspnea
Ground-state properties of trapped Bose-Fermi mixtures: role of exchange-correlation
We introduce Density Functional Theory for inhomogeneous Bose-Fermi mixtures,
derive the associated Kohn-Sham equations, and determine the
exchange-correlation energy in local density approximation. We solve
numerically the Kohn-Sham system and determine the boson and fermion density
distributions and the ground-state energy of a trapped, dilute mixture beyond
mean-field approximation. The importance of the corrections due to
exchange--correlation is discussed by comparison with current experiments; in
particular, we investigate the effect of of the repulsive potential energy
contribution due to exchange--correlation on the stability of the mixture
against collapse.Comment: 6 pages, 4 figures (final version as published in Physical Review
Spin relaxation in semiconductor quantum dots
We have studied the physical processes responsible for the spin -flip in GaAs
quantum dots. We have calculated the rates for different mechanisms which are
related to spin-orbit coupling and cause a spin-flip during the inelastic
relaxation of the electron in the dot both with and without a magnetic field.
We have shown that the zero-dimensional character of the problem when electron
wave functions are localized in all directions leads to freezing out of the
most effective spin-flip mechanisms related to the absence of the inversion
centers in the elementary crystal cell and at the heterointerface and, as a
result, to unusually low spin-flip rates.Comment: 6 pages, RevTe
Survivors of Chronic Stroke Experience Continued Impairment of Dexterity But Not Strength in the Nonparetic Upper Limb
Objective
To investigate the performance of the less affected upper limb in people with stroke compared with normative values. To examine less affected upper limb function in those whose prestroke dominant limb became paretic and those whose prestroke nondominant limb became paretic. Design
Cohort study of survivors of chronic stroke (7.2±6.7y post incident). Setting
The study was performed at a freestanding academic rehabilitation hospital. Participants
Survivors of chronic stroke (N=40) with severe hand impairment (Chedoke-McMaster Stroke Assessment rating of 2-3 on Stage of Hand) participated in the study. In 20 participants the prestroke dominant hand (DH) was tested (nondominant hand [NH] affected by stroke), and in 20 participants the prestroke NH was tested (DH affected by stroke). Interventions
Not applicable. Main Outcome Measure
Jebsen-Taylor Hand Function Test. Data from survivors of stroke were compared with normative age- and sex-matched data from neurologically intact individuals. Results
When combined, DH and NH groups performed significantly worse on fine motor tasks with their nonparetic hand relative to normative data (PP\u3e.140). Conclusions
Survivors of stroke with severe impairment of the paretic limb continue to present significant upper extremity impairment in their nominally nonparetic limb even years after stroke. This phenomenon was observed regardless of whether the DH or NH hand was primarily affected. Because this group of survivors of stroke is especially dependent on the nonparetic limb for performing functional tasks, our results suggest that the nonparetic upper limb should be targeted for rehabilitation
The Anatomy of the Facial Vein: Implications for Plastic, Reconstructive, and Aesthetic Procedures
Background: Anatomical knowledge of the facial vasculature is crucial for successful plastic, reconstructive, and minimally invasive procedures of the face. Whereas the majority of previous investigations focused on facial arteries, the precise course, variability, and relationship with adjacent structures of the facial vein have been widely neglected. Methods: Seventy-two fresh frozen human cephalic cadavers (32 male and 40 female cadavers;mean age, 75.2 +/- 10.9 years;mean body mass index, 24.2 +/- 6.6 kg/m(2);99 percent Caucasian ethnicity) were investigated by means of layer-by-layer anatomical dissection. In addition, 10 cephalic specimens were investigated using contrast agent-enhanced computed tomographic imaging. Results: The facial vein displayed a constant course in relation to the adjacent anatomical structures. The vein was identified posterior to the facial artery, anterior to the parotid duct, and deep to the zygomaticus major muscle. The angular vein formed the lateral boundary of the deep medial cheek fat and the premaxillary space, and the medial boundary of the deep lateral cheek fat and the suborbicularis oculi fat. The mean distance of the inferior and superior labial veins, of the deep facial vein, and of the angular vein from the inferior orbital margin was 51.6 +/- 3.1, 42.6 +/- 2.3, 27.4 +/- 3.0, and 4.2 +/- 0.7 mm, respectively. Conclusions: This work provides detailed information on the course of the facial vein in relation to neighboring structures. The presented clinically relevant anatomical observations and descriptions of landmarks will serve as helpful information for plastic, reconstructive, and aesthetic surgeons
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