45 research outputs found
Case Report: Ischial Stress Fracture Non-Union in a College Football Player
Stress fractures are common injuries associated with repetitive high-impact activities, often in high-level athletes and military recruits. Although predominantly occurring in the lower extremities, stress fractures may occur wherever there is a sudden increase in frequency or intensity of activity, thereby overloading the yield point of the local bone environment. Ischial stress fractures are a rarely diagnosed cause of pain around the hip and pelvis. Often, patients present with buttock pain with activity, which can be misdiagnosed as proximal hamstring tendonitis or avulsion. Here, we report a case of a college football player who was diagnosed with an ischial stress fracture which went on to symptomatic non-union after extensive conservative management. We treated his ischial non-union with open reduction internal fixation utilizing a tension band plate and screws. This interesting case highlights an uncommon cause of the relatively common presentation of posterior hip pain and describes our technique for addressing a stress fracture non-union in the ischium
A taxonomy for solar fuels generators
A number of approaches to solar fuels generation are being developed, each of which has associated
advantages and challenges. Many of these solar fuels generators are identified as âphotoelectrochemical
cellsâ even though these systems collectively operate based on a suite of fundamentally different
physical principles. To facilitate appropriate comparisons between solar fuels generators, as well as to
enable concise and consistent identification of the state-of-the-art for designs based on comparable
operating principles, we have developed a taxonomy and nomenclature for solar fuels generators based
on the source of the asymmetry that separates photogenerated electrons and holes. Three basic device
types have been identified: photovoltaic cells, photoelectrochemical cells, and particulate/molecular
photocatalysts. We outline the advantages and technological challenges associated with each type, and
provide illustrative examples for each approach as well as for hybrid approaches
Pennsylvania Folklife Vol. 30, No. 4
⢠Farm Animals at the Kutztown Folk Festival ⢠Outdoor Ovens in the Dutch Country ⢠Gold and Silversmithing at the Kutztown Folk Festival: A Look at the Craftsmen and Their Techniques ⢠An Early Pennsylvania Dutch Garden Revisited ⢠The Amish Wedding ⢠Festival Focus ⢠Folk Festival Programs ⢠Quilts and Quilting: Picking the Winners ⢠Macrame: The Art of Creative Knotting ⢠Pennsylvania Dutch Funeral Lore: They Honored Their Dead ⢠The Making of Maple Syrup ⢠Textile Arts Reach Back Into Historyhttps://digitalcommons.ursinus.edu/pafolklifemag/1092/thumbnail.jp
Quantitative Multicolor Compositional Imaging Resolves Molecular Domains in Cell-Matrix Adhesions
Background: Cellular processes occur within dynamic and multi-molecular compartments whose characterization requires analysis at high spatio-temporal resolution. Notable examples for such complexes are cell-matrix adhesion sites, consisting of numerous cytoskeletal and signaling proteins. These adhesions are highly variable in their morphology, dynamics, and apparent function, yet their molecular diversity is poorly defined. Methodology/Principal Findings: We present here a compositional imaging approach for the analysis and display of multicomponent compositions. This methodology is based on microscopy-acquired multicolor data, multi-dimensional clustering of pixels according to their composition similarity and display of the cellular distribution of these composition clusters. We apply this approach for resolving the molecular complexes associated with focal-adhesions, and the time-dependent effects of Rho-kinase inhibition. We show here compositional variations between adhesion sites, as well as ordered variations along the axis of individual focal-adhesions. The multicolor clustering approach also reveals distinct sensitivities of different focaladhesion-associated complexes to Rho-kinase inhibition. Conclusions/Significance: Multicolor compositional imaging resolves ââmolecular signaturesâ â characteristic to focaladhesions and related structures, as well as sub-domains within these adhesion sites. This analysis enhances the spatial information with additional ââcontents-resolvedâ â dimensions. We propose that compositional imaging can serve as
Pulsation and stabilization: Contractile forces that underlie morphogenesis
Embryonic development involves global changes in tissue shape and architecture that are driven by cell shape changes and rearrangements within cohesive cell sheets. Morphogenetic changes at the cell and tissue level require that cells generate forces and that these forces are transmitted between the cells of a coherent tissue. Contractile forces generated by the actinâmyosin cytoskeleton are critical for morphogenesis, but the cellular and molecular mechanisms of contraction have been elusive for many cell shape changes and movements. Recent studies that have combined live imaging with computational and biophysical approaches have provided new insights into how contractile forces are generated and coordinated between cells and tissues. In this review, we discuss our current understanding of the mechanical forces that shape cells, tissues, and embryos, emphasizing the different modes of actomyosin contraction that generate various temporal and spatial patterns of force generation.American Cancer Society (grant PF-06- 143-01-DDC
Open versus minimally invasive fixation of a simulated syndesmotic injury in a cadaver model
Abstract Background Malreduction of unstable syndesmotic ankle fractures is common. This study compared the reduction quality of an anterolateral open technique (OT) versus a conventional minimally invasive technique (MIT). Methods Fourteen fresh-frozen lower torso specimens with 28 matched lower extremities underwent computed tomography (CT) to measure syndesmosis position before dissection. Reduction was performed using direct visualization and fluoroscopy for the OT group (right-sided specimens) and fluoroscopy only for the MIT group (left-sided specimens). Fixation was achieved with 2 cortical screws. Measurements were repeated with postfixation CT scans. Statistical analysis used a two-tailed t test (ι = 0.05). Results Mean posterior fibula-tibia distance decreased after OT by 0.3 ¹ 0.5 mm and increased after MIT by 0.7 ¹ 0.6 mm (P = 0.025 for difference between techniques). Mean anterior fibula-tibia distance decreased after OT by 0.4 ¹ 0.2 mm (P = 0.007) and did not change significantly after MIT (ââ0.01 ¹ 0.4 mm (P = 0.686). Mean anterior translation after OT was 0.04 ¹ 0.4 mm (P = 0.856), and mean posterior translation after MIT was 0.3 ¹ 0.7 mm (P = 0.434). Mean medialization after OT was 0.3 ¹ 0.4 mm (P = 0.132), and mean lateralization after MIT was 0.2 ¹ 0.6 mm (P = 0.446). Conclusions Both techniques produced near-anatomic reduction of the fibula, with MIT producing significantly more internal rotation malreduction than OT. OT appears to restore near-anatomic fibula position, although this did not differ significantly from the results of MIT. We conditionally recommend OT when closed reduction of the syndesmosis cannot be obtained
Stable Solar-Driven Water Oxidation to O<sub>2</sub>(g) by Ni-Oxide-Coated Silicon Photoanodes
Semiconductors
with small band gaps (<2 eV) must be stabilized
against corrosion or passivation in aqueous electrolytes before such
materials can be used as photoelectrodes to directly produce fuels
from sunlight. In addition, incorporation of electrocatalysts on the
surface of photoelectrodes is required for efficient oxidation of
H<sub>2</sub>O to O<sub>2</sub>(g) and reduction of H<sub>2</sub>O
or H<sub>2</sub>O and CO<sub>2</sub> to fuels. We report herein the
stabilization of np<sup>+</sup>-SiÂ(100) and n-Si(111) photoanodes
for over 1200 h of continuous light-driven evolution of O<sub>2</sub>(g) in 1.0 M KOHÂ(aq) by an earth-abundant, optically transparent,
electrocatalytic, stable, conducting nickel oxide layer. Under simulated
solar illumination and with optimized index-matching for proper antireflection,
NiO<sub><i>x</i></sub>-coated np<sup>+</sup>-SiÂ(100) photoanodes
produced photocurrent-onset potentials of â180 Âą 20 mV
referenced to the equilibrium potential for evolution of O<sub>2</sub>(g), photocurrent densities of 29 Âą 1.8 mA cm<sup>â2</sup> at the equilibrium potential for evolution of O<sub>2</sub>(g),
and a solar-to-O<sub>2</sub>(g) conversion figure-of-merit of 2.1%
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Modeling, Simulation, and Implementation of Solar-Driven Water-Splitting Devices.
An integrated cell for the solar-driven splitting of water consists of multiple functional components and couples various photoelectrochemical (PEC) processes at different length and time scales. The overall solar-to-hydrogen (STH) conversion efficiency of such a system depends on the performance and materials properties of the individual components as well as on the component integration, overall device architecture, and system operating conditions. This Review focuses on the modeling- and simulation-guided development and implementation of solar-driven water-splitting prototypes from a holistic viewpoint that explores the various interplays between the components. The underlying physics and interactions at the cell level is are reviewed and discussed, followed by an overview of the use of the cell model to provide target properties of materials and guide the design of a range of traditional and unique device architectures
A photoactivatable marker protein for pulse-chase imaging with superresolution
IrisFP is a photoactivatable fluorescent protein that combines irreversible photoconversion from a green- to a red-emitting form with reversible photoswitching between a fluorescent and a nonfluorescent state in both forms. Here we introduce a monomeric variant, mIrisFP, and demonstrate how its multiple photoactivation modes can be used for pulse-chase experiments combined with subdiffraction-resolution imaging in living cells by using dual-color photoactivation localization microscopy (PALM)