303 research outputs found
Unified Treatment of Asymptotic van der Waals Forces
In a framework for long-range density-functional theory we present a unified
full-field treatment of the asymptotic van der Waals interaction for atoms,
molecules, surfaces, and other objects. The only input needed consists of the
electron densities of the interacting fragments and the static polarizability
or the static image plane, which can be easily evaluated in a ground-state
density-functional calculation for each fragment. Results for separated atoms,
molecules, and for atoms/molecules outside surfaces are in agreement with those
of other, more elaborate, calculations.Comment: 6 pages, 5 figure
Saffold virus is able to productively infect primate and rodent cell lines and induces apoptosis in these cells
10.1038/emi.2014.15Emerging Microbes and Infections3
Novel Rodent Models for Macular Research
BACKGROUND: Many disabling human retinal disorders involve the central retina, particularly the macula. However, the commonly used rodent models in research, mouse and rat, do not possess a macula. The purpose of this study was to identify small laboratory rodents with a significant central region as potential new models for macular research.
METHODOLOGY/PRINCIPAL FINDINGS: Gerbillus perpallidus, Meriones unguiculatus and Phodopus campbelli, laboratory rodents less commonly used in retinal research, were subjected to confocal scanning laser ophthalmoscopy (cSLO), fluorescein and indocyanine green angiography, and spectral-domain optical coherence tomography (SD-OCT) using standard equipment (Heidelberg Engineering HRA1 and Spectralisâą) adapted to small rodent eyes. The existence of a visual streak-like pattern was assessed on the basis of vascular topography, retinal thickness, and the topography of retinal ganglion cells and cone photoreceptors. All three species examined showed evidence of a significant horizontal streak-like specialization. cSLO angiography and retinal wholemounts revealed that superficial retinal blood vessels typically ramify and narrow into a sparse capillary net at the border of the respective area located dorsal to the optic nerve. Similar to the macular region, there was an absence of larger blood vessels in the streak region. Furthermore, the thickness of the photoreceptor layer and the population density of neurons in the ganglion cell layer were markedly increased in the visual streak region.
CONCLUSIONS/SIGNIFICANCE: The retinal specializations of Gerbillus perpallidus, Meriones unguiculatus and Phodopus campbelli resemble features of the primate macula. Hence, the rodents reported here may serve to study aspects of macular development and diseases like age-related macular degeneration and diabetic macular edema, and the preclinical assessment of therapeutic strategies
Substance abuse treatment and psychiatric comorbidity: do benefits spill over? analysis of data from a prospective trial among cocaine-dependent homeless persons
BACKGROUND: Comorbid psychiatric illness can undermine outcomes among homeless persons undergoing addiction treatment, and psychiatric specialty care is not always readily available. The prognosis for nonsubstance abuse psychiatric diagnoses among homeless persons receiving behaviorally-based addiction treatment, however, is little studied. RESULTS: Data from an addiction treatment trial for 95 cocaine-dependent homeless persons (1996â1998) were used to profile psychiatric diagnoses at baseline and 6 months, including mood-related disorders (e.g. depression) and anxiety-related disorders (e.g. post-traumatic stress disorder). Treatment interventions, including systematic reinforcement for goal attainment, were behavioral in orientation. There was a 32% reduction in the prevalence of comorbid non-addiction psychiatric disorder from baseline to 6 months, with similar reductions in the prevalence of mood (-32%) and anxiety-related disorders (-20%) (p = 0.12). CONCLUSION: Among cocaine-dependent homeless persons with psychiatric comorbidity undergoing behavioral addiction treatment, a reduction in comorbid psychiatric disorder prevalence was observed over 6 months. Not all participants improved, suggesting that even evidence-based addiction treatment will prove insufficient for a meaningful proportion of the dually diagnosed homeless population
Ulnar-sided wrist pain. Part I: anatomy and physical examination
Ulnar-sided wrist pain is a common complaint, and it presents a diagnostic challenge for hand surgeons and radiologists. The complex anatomy of this region, combined with the small size of structures and subtle imaging findings, compound this problem. A thorough understanding of ulnar-sided wrist anatomy and a systematic clinical examination of this region are essential in arriving at an accurate diagnosis. In part I of this review, ulnar-sided wrist anatomy and clinical examination are discussed for a more comprehensive understanding of ulnar-sided wrist pain
Ulnar-sided wrist pain. II. Clinical imaging and treatment
Pain at the ulnar aspect of the wrist is a diagnostic challenge for hand surgeons and radiologists due to the small and complex anatomical structures involved. In this article, imaging modalities including radiography, arthrography, ultrasound (US), computed tomography (CT), CT arthrography, magnetic resonance (MR) imaging, and MR arthrography are compared with regard to differential diagnosis. Clinical imaging findings are reviewed for a more comprehensive understanding of this disorder. Treatments for the common diseases that cause the ulnar-sided wrist pain including extensor carpi ulnaris (ECU) tendonitis, flexor carpi ulnaris (FCU) tendonitis, pisotriquetral arthritis, triangular fibrocartilage complex (TFCC) lesions, ulnar impaction, lunotriquetral (LT) instability, and distal radioulnar joint (DRUJ) instability are reviewed
Barriers to Predicting the Mechanisms and Risk Factors of Non-Contact Anterior Cruciate Ligament Injury
High incidences of non-contact anterior cruciate ligament (ACL) injury, frequent requirements for ACL reconstruction, and limited understanding of ACL mechanics have engendered considerable interest in quantifying the ACL loading mechanisms. Although some progress has been made to better understand non-contact ACL injuries, information on how and why non-contact ACL injuries occur is still largely unavailable. In other words, research is yet to yield consensus on injury mechanisms and risk factors. Biomechanics, video analysis, and related study approaches have elucidated to some extent how ACL injuries occur. However, these approaches are limited because they provide estimates, rather than precise measurements of knee - and more specifically ACL - kinematics at the time of injury. These study approaches are also limited in their inability to simultaneously capture many of the contributing factors to injury
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