In Silico Finite Element Analysis of the Foot Ankle Complex Biomechanics: A Literature Review.

Computational approaches, especially finite element analysis (FEA), have been rapidly growing in both academia and industry during the last few decades. FEA serves as a powerful and efficient approach for simulating real-life experiments, including industrial product development, machine design, and biomedical research, particularly in biomechanics and biomaterials. Accordingly, FEA has been a "go-to" high biofidelic software tool to simulate and quantify the biomechanics of the foot-ankle complex, as well as to predict the risk of foot and ankle injuries, which are one of the most common musculoskeletal injuries among physically active individuals. This paper provides a review of the in silico FEA of the foot-ankle complex. First, a brief history of computational modeling methods and finite element (FE) simulations for foot-ankle models is introduced. Second, a general approach to build an FE foot and ankle model is presented, including a detailed procedure to accurately construct, calibrate, verify, and validate an FE model in its appropriate simulation environment. Third, current applications, as well as future improvements of the foot and ankle FE models, especially in the biomedical field, are discussed. Finally, a conclusion is made on the efficiency and development of FEA as a computational approach in investigating the biomechanics of the foot-ankle complex. Overall, this review integrates insightful information for biomedical engineers, medical professionals, and researchers to conduct more accurate research on the foot-ankle FE models in the future.

The long-lasting antidepressant effects of rapastinel (GLYX-13) are associated with a metaplasticity process in the medial prefrontal cortex and hippocampus.

Rapastinel (GLYX-13) is an N-methyl-d-aspartate receptor (NMDAR) modulator that has characteristics of a glycine site partial agonist. Rapastinel is a robust cognitive enhancer and facilitates hippocampal long-term potentiation (LTP) of synaptic transmission in slices. In human clinical trials, rapastinel has been shown to produce marked antidepressant properties that last for at least one week following a single dose. The long-lasting antidepressant effect of a single dose of rapastinel (3mg/kg IV) was assessed in rats using the Porsolt, open field and ultrasonic vocalization assays. Cognitive enhancement was examined using the Morris water maze, positive emotional learning, and contextual fear extinction tests. LTP was assessed in hippocampal slices. Dendritic spine morphology was measured in the dentate gyrus and the medial prefrontal cortex. Significant antidepressant-like or cognitive enhancing effects were observed that lasted for at least one week in each model. Rapastinel facilitated LTP 1day-2weeks but not 4weeks post-dosing. Biweekly dosing with rapastinel sustained this effect for at least 8weeks. A single dose of rapastinel increased the proportion of whole-cell NMDAR current contributed by NR2B-containing NMDARs in the hippocampus 1week post-dosing, that returned to baseline by 4weeks post-dosing. The NMDAR antagonist 3-(2-carboxypiperazin-4-yl)propyl-1-phosphonic acid (CPP) blocked the antidepressant-like effect of rapastinel 1week post dosing. A single injection of rapastinel also increased mature spine density in both brain regions 24h post-dosing. These data demonstrate that rapastinel produces its long-lasting antidepressant effects via triggering NMDAR-dependent processes that lead to increased sensitivity to LTP that persist for up to two weeks. These data also suggest that these processes led to the alterations in dendritic spine morphologies associated with the maintenance of long-term changes in synaptic plasticity associated with learning and memory.

Measurement of the plasma astrophysical S factor for the 3He(d,p)4He reaction in exploding molecular clusters.

The plasma astrophysical S factor for the 3He(d,p)4He fusion reaction was measured for the first time at temperatures of few keV, using the interaction of intense ultrafast laser pulses with molecular deuterium clusters mixed with 3He atoms. Different proportions of D2 and 3He or CD4 and 3He were mixed in the gas target in order to allow the measurement of the cross section for the 3He(d,p)4He reaction. The yield of 14.7 MeV protons from the 3He(d,p)4He reaction was measured in order to extract the astrophysical S factor at low energies. Our result is in agreement with other S factor parametrizations found in the literature.

Randomised, double-blind, placebo-controlled clinical trial of a new topical glyceryl trinitrate patch for chronic lateral epicondylosis.

OBJECTIVE: This study aimed to determine whether a new glyceryl trinitrate patch preparation is effective in treating chronic lateral epicondylosis. DESIGN: Randomised double-blind controlled clinical trial. SETTING: Private practice PATIENTS: 154 adult patients with chronic lateral epicondylosis were recruited, with 136 patients completing the trial. INTERVENTIONS: 8 weeks of glyceryl trinitrate patch application (dosages of 72 mg/24 h, 1.44 mg/24 h, and 3.6 mg/24 h), or placebo patch application. MAIN OUTCOME MEASURES: Subjective global assessment of change in elbow symptoms, patient-rated tennis elbow evaluation, visual analogue pain at rest, visual analogue pain with activity, visual analogue pain intensity, grip strength, and strength testing using the Orthopaedic Research Institute-Tennis Elbow Testing System. RESULTS: At 8 weeks there was a significant decrease in elbow pain with activity in the glyceryl trinitrate 0.72 mg/24 h group compared with placebo (p = 0.04). There were no other significant differences. CONCLUSIONS: Continuous 1.25 mg/24 h topical glyceryl trinitrate treatment, when combined with daily exercise rehabilitation, has previously demonstrated efficacy in treating chronic lateral epicondylosis. There was significantly decreased elbow pain with activity at 8 weeks in the glyceryl trinitrate 0.72 mg/24 h group (p = 0.04). This short-term dose-ranging study did not demonstrate a treatment effect of a new topical glyceryl trinitrate patch in dosages of 1.44 mg/24 h or 3.6 mg/24 h, which conflicts with previous studies on topical glyceryl trinitrate treatment. TRIAL REGISTRATION NUMBER: NCT00447928.

The energetics of tetrahydrocarbazole aromatization over Pd(111): a computational analysis.

The carbazole moiety is a component of many important pharmaceuticals including anticancer and anti-HIV agents and is commonly utilized in the production of modern polymeric materials with novel photophysical and electronic properties. Simple carbazoles are generally produced via the aromatization of the respective tetrahydrocarbazole (THCZ). In this work, density functional theory calculations are used to model the reaction pathway of tetrahydrocarbazole aromatization over Pd(111). The geometry of each of the intermediate surface species has been determined and how each structure interacts with the metal surface addressed. The reaction energies and barriers of each of the elementary surface reactions have also been calculated, and a detailed analysis of the energetic trends performed. Our calculations have shown that the surface intermediates remain fixed to the surface via the aromatic ring in a manner similar to that of THCZ. Moreover, the aliphatic ring becomes progressively more planer with the dissociation of each subsequent hydrogen atom. Analysis of the reaction energy profile has revealed that the trend in reaction barriers is determined by the two factors: (i) the strength of the dissociating ring-H bond and (ii) the subsequent gain in energy due to the geometric relaxation of the aliphatic ring.

DFT and in situ EXAFS investigation of gold/ceria-zirconia low-temperature water gas shift catalysts: identification of the nature of the active form of gold.

A combined experimental and theoretical investigation of the nature of the active form of gold in oxide-supported gold catalysts for the water gas shift reaction has been performed. In situ extended X-ray absorption fine structure (EXAFS) and X-ray absorption near-edge structure (XANES) experiments have shown that in the fresh catalysts the gold is in the form of highly dispersed gold ions. However, under water gas shift reaction conditions, even at temperatures as low as 100 degrees C, the evidence from EXAFS and XANES is only consistent with rapid, and essentially complete, reduction of the gold to form metallic clusters containing about 50 atoms. The presence of Au-Ce distances in the EXAFS spectra, and the fact that about 15% of the gold atoms can be reoxidized after exposure to air at 150 degrees C, is indicative of a close interaction between a fraction (ca. 15%) of the gold atoms and the oxide support. Density functional theory (DFT) calculations are entirely consistent with this model and suggest that an important aspect of the active and stable form of gold under water gas shift reaction conditions is the location of a partially oxidized gold (Audelta+) species at a cerium cation vacancy in the surface of the oxide support. It is found that even with a low loading gold catalysts (0.2%) the fraction of ionic gold under water gas shift conditions is below the limit of detection by XANES (<5%). It is concluded that under water gas shift reaction conditions the active form of gold comprises small metallic gold clusters in intimate contact with the oxide support.

Acrylamide reduction in processed foods.

The discovery of the formation of acrylamide in fried and baked foods containing high levels of starch and the amino acid asparagine, prompted widespread concern. Both processed and home cooked foods are affected and this has led to the increased study of variations in cooking and processing conditions to minimize formation. While changes in cooking protocols have been in part successful, particularly when lower frying and baking temperatures are used, pretreatments to reduce levels of acrylamide by prevention of formation or acceleration of destruction have been investigated. In this study, a range of pretreatments of grilled potato were investigated and compared with surface washing to remove asparagine and reducing sugars. Synergies were observed between different treatments, and reductions of up to 40% were achieved in a non-optimized system.

The mechanism of N2O formation via the (NO)2 dimer: a density functional theory study.

Catalytic formation of N(2)O via a (NO)(2) intermediate was studied employing density functional theory with generalized gradient approximations. Dimer formation was not favored on Pt(111), in agreement with previous reports. On Pt(211) a variety of dimer structures were studied, including trans-(NO)(2) and cis-(NO)(2) configurations. A possible pathway involving (NO)(2) formation at the terrace near to a Pt step is identified as the possible mechanism for low-temperature N(2)O formation. The dimer is stabilized by bond formation between one O atom of the dimer and two Pt step atoms. The overall mechanism has a low barrier of approximately 0.32 eV. The mechanism is also put into the context of the overall NO + H(2) reaction. A consideration of the step-wise hydrogenation of O(ads) from the step is also presented. Removal of O(ads) from the step is significantly different from O(ads) hydrogenation on Pt(111). The energetically favored structure at the transition state for OH(ads) formation has an activation energy of 0.63 eV. Further hydrogenation of OH(ads) has an activation energy of 0.80 eV.

Low-temperature catalytic decomposition of N2O on platinum and bismuth-modified platinum: identification of active sites.

Classification of the active surface sites of platinum catalysts responsible for low temperature N2O decomposition, in terms of steps, kinks and terraces, has been achieved by controlled addition of bismuth to as-received platinum/graphite catalysts.

Sex differences in olfactory self-recognition.

This study investigated sex differences in the ability to recognize one's own body odor accompanied by an attempt to account for variance in this ability by comparing ratings of self-body odor and other odors on a visual analog scale (VAS). Whereas over half (59.4%) of the females were able to identify their own odor, only one out of 18 (5.6%) males were able to recognize their own odor. Females rated their own secretions as significantly lower on a pleasant-positive factor than males rated their own odors (axillary secretions), but there was no difference in ratings between those who could and those who could not identify their own odor. The dimensions tapped by the VAS used in this study do not seem to account for the ability to identify one's own body odors.

Eye movement patterns of captioned television viewers.

Eye movement of six subjects was recorded as they watched video segments with and without captions. It was found that the addition of captions to a video resulted in major changes in eye movement patterns, with the viewing process becoming primarily a reading process. Further, although people viewing a specific video segment are likely to have similar eye movement patterns, there are also distinct individual differences present in these patterns. For example, someone accustomed to speechreading may spend more time looking at an actor's lips, while someone with poor English skills may spend more time reading the captions. Finally, there is some preliminary evidence to suggest that higher captioning speed results in more time spent reading captions on a video segment.

Time spent viewing captions on television programs.

The eye movements of 23 deaf subjects, ages 14 to 61 years, were recorded 30 times per second while the subjects watched four 2.5-minute captioned television programs. The eye movement data were analyzed to determine the percentage of time each subject actually looked at the captions on the screen. It was found that subjects gazed at the captions 84% of the time, at the video picture 14% of the time, and off the video 2% of the time. Age, sex, and educational level appeared to have little influence on time spent viewing captions. When caption speed increased from the slowest speed (100 words per minute, or wpm) to the fastest speed (180 wpm), mean percentage of time spent gazing at captions increased only from 82% to 86%. A distinctive characteristic of the data was the considerable variation from subject to subject and also within subjects (from video to video) in regard to percentage of time spent gazing at captions.

Seattle YouthCare's prevention, intervention, and education program: a model of care for HIV-positive, homeless, and at-risk youth.

YouthCare's project for youth who are human immunodeficiency virus (HIV)-positive or at high risk for becoming HIV positive is one of 10 supported by Special Projects of National Significance Program, HIV/Acquired Immunodeficiency Syndrome Bureau, Health Resources and Services Administration. Throughout its 23-year history, YouthCare has focused on serving runaway, homeless, sexual minority, and other youth "on the margins." To respond effectively to the needs of these youth, YouthCare has developed creative service approaches including involving youth in program design and taking the programs to where the youth live. Building on this experience, the agency developed a continuum of services which has provided care to 906 youth, including 37 who are HIV positive. The five major elements of the model include: (a) youth-specific HIV antibody test counseling, (b) outreach, (c) intensive case management for HIV-positive youth, (d) prevention services for youth at high risk of HIV infection, and (e) peer involvement. Quantitative evaluation helped in identifying youth served by the project (e.g., over one third self-identify as a sexual minority) and the sites at which services should be provided. Preliminary results from qualitative evaluations have stressed the importance of teamwork in designing clinical interventions and providing support to direct-service staff. This report's conclusion stresses that case management for this population, even though time and resource-intensive, is effective, and that services need to be flexible and tailored to each client's needs.

Human eosinophil-granule major basic protein and synthetic polycations induce airway hyperresponsiveness in vivo dependent on bradykinin generation.

In the current series of experiments we investigated the role of bradykinin in airway hyperresponsiveness induced by human eosinophil-granule major basic protein (MBP). Bronchoalveolar lavage was performed after intratracheal instillation of MBP or poly-L-lysine in anesthetized, intubated rats, and levels of immunoreactive kinins and kallikrein-like activity were determined. Both MBP and poly-L-lysine induced a three- and eightfold increase in levels of kallikrein-like activity and i-kinins, respectively. To determine whether kinin production is required for the development of airway hyperresponsiveness induced by cationic proteins, dose-response curves to methacholine were constructed before and 1 h after intratracheal instillation of either MBP or poly-L-lysine (100 micrograms). MBP and poly-L-lysine induced an increase in airway responsiveness, which was inhibited by pretreatment with a selective BK-2 receptor antagonist, NPC 17713 (250 micrograms/ml). Our results demonstrate that MBP and poly-L-lysine activate kallikrein and stimulate the generation of i-kinins in vivo, an effect that may be related to the cationic charge of these proteins. Furthermore, the ability of these proteins to increase airway responsiveness appears to be dependent on the generation of i-kinins.