The Achilles tendon (AT) consists of fibers originating from the soleus muscle (SOL), which lies deep, and the medial (GM) and lateral (GL) heads of the gastrocnemius muscle, which lie superficial. ...As the fibers descend toward the insertion of the AT, the individual subtendons twist around each other. The aim of this study was to investigate the twisted structure of the AT and its individual subtendons. Specimens of the AT, with preserved calcaneal bone and a fragment of the triceps surae muscle, were obtained from 53 fresh‐frozen, male cadavers (n=106 lower limbs). The angle of torsion of each of the AT's subtendons was measured using a specially designed and 3D‐printed tool. The mean distance between the most distal fibers of the triceps surae muscle and the superior border of the calcaneal bone was 60.77±14.15 mm. The largest component of the AT at the level of its insertion into the calcaneal bone is the subtendon from the GL (44.43%), followed by the subtendon from SOL (27.89%), and the subtendon from GM (27.68%). The fibers originating from the GM rotate on average 28.17±15.15°, while the fibers originating from the GL and SOL twist 135.98±33.58° and 128.58±29.63°, respectively. The torsion of superficial fibers (GM) comprising the AT is significantly lower than that of deeper fibers (GL and SOL). The cross‐sectional area of the AT is smaller at the level of the musculo‐tendinous junction than at the level of its insertion. This study illustrates the three types of the AT with differently twisting subtendons, as well as a generalized model of the AT. Types of AT torsion may potentially alter the biomechanical properties of the tendon, thus possibly influencing the pathophysiologic mechanisms leading to the development of various tendinopathies.
Predicting the biological function potential of post-translational modifications (PTMs) is becoming increasingly important in light of the exponential increase in available PTM data from ...high-throughput proteomics. We developed structural analysis of PTM hotspots (SAPH-ire)—a quantitative PTM ranking method that integrates experimental PTM observations, sequence conservation, protein structure, and interaction data to allow rank order comparisons within or between protein families. Here, we applied SAPH-ire to the study of PTMs in diverse G protein families, a conserved and ubiquitous class of proteins essential for maintenance of intracellular structure (tubulins) and signal transduction (large and small Ras-like G proteins). A total of 1728 experimentally verified PTMs from eight unique G protein families were clustered into 451 unique hotspots, 51 of which have a known and cited biological function or response. Using customized software, the hotspots were analyzed in the context of 598 unique protein structures. By comparing distributions of hotspots with known versus unknown function, we show that SAPH-ire analysis is predictive for PTM biological function. Notably, SAPH-ire revealed high-ranking hotspots for which a functional impact has not yet been determined, including phosphorylation hotspots in the N-terminal tails of G protein gamma subunits—conserved protein structures never before reported as regulators of G protein coupled receptor signaling. To validate this prediction we used the yeast model system for G protein coupled receptor signaling, revealing that gamma subunit–N-terminal tail phosphorylation is activated in response to G protein coupled receptor stimulation and regulates protein stability in vivo. These results demonstrate the utility of integrating protein structural and sequence features into PTM prioritization schemes that can improve the analysis and functional power of modification-specific proteomics data.
Little is known about why patients with low back pain (LBP) respond differently to treatment, and more specifically, to a lumbar stabilization exercise program. As a first step toward answering this ...question, the present study evaluates how subgroups of patients who demonstrate large and small clinical improvements differ in terms of physical and psychological changes during treatment.
Participants (n = 110) performed the exercise program (clinical sessions and home exercises) over eight weeks, with 100 retained at six-month follow-up. Physical measures (lumbar segmental instability, motor control impairments, range of motion, trunk muscle endurance and physical performance tests) were collected twice (baseline, end of treatment), while psychological measures (fear-avoidance beliefs, pain catastrophizing, psychological distress, illness perceptions, outcome expectations) were collected at four time points (baseline, mid-treatment, end of treatment, follow-up). The participants were divided into three subgroups (large, moderate and small clinical improvements) based on the change of perceived disability scores. ANOVA for repeated measure compared well-contrasted subgroups (large vs. small improvement) at different times to test for SUBGROUP × TIME interactions.
Statistically significant interactions were observed for several physical and psychological measures. In all these interactions, the large- and small-improvement subgroups were equivalent at baseline, but the large-improvement subgroup showed more improvements over time compared to the small-improvement subgroup. For psychological measures only (fear-avoidance beliefs, pain catastrophizing, illness perceptions), between-group differences reached moderate to strong effect sizes, at the end of treatment and follow-up.
The large-improvement subgroup showed more improvement than the small-improvement subgroup with regard to physical factors typically targeted by this specific exercise program as well as for psychological factors that are known to influence clinical outcomes.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Two studies of 100 children aged 3–12 years examined theory of mind (ToM) understanding via explanations and predictions in hearing preschoolers and ToM‐delayed deaf children. Study 1's 75 children ...(31 deaf; 44 hearing) displayed an “explanation advantage,” devising valid epistemic ToM explanations despite failing simpler forced‐choice false‐belief (FB) prediction tests. This novel discovery for deaf children extended to unexpectedly frequent cognitive (“think” or “know”) explanations. Study 2 (with 25 additional deaf children; Mage = 9) showed that microgenetic FB explanation practice resulted in significant gains on FB prediction posttests that were absent in a non‐ToM control group. Implications for (a) explanation's interconnection with conceptual development, (b) designing ToM interventions, and (c) teaching deaf and hearing children are discussed.
Neonatal mouse hearts have a regenerative capacity similar to adult zebrafish. Different cardiac injury models have been established to investigate the regenerative capacity of neonatal mouse hearts, ...including ventricular amputation, cryoinjury, and ligation of a major coronary artery. While the ventricular resection model can be utilized to study how tissue forms and regenerates de novo, cryoinjury and coronary artery ligation are methods that might better mimic myocardial infarction by creating tissue damage and necrosis as opposed to the removal of healthy tissue in the ventricular amputation model. Here we describe methods of creating ventricular resection and cardiac cryoinjury in newborn mice.
Chabazite (CHA) molecular sieves, which are industrial catalysts for the selective reduction of nitrogen oxides and the conversion of methanol into olefins, are also ideal materials in catalysis ...research because their crystalline frameworks contain one unique tetrahedral site. The presence of a single lattice site allows for more accurate descriptions of experimental data using theoretical models and consequently for precise structure–function relationships of active sites incorporated into framework positions. A direct hydrothermal synthesis route to prepare pure-silica chabazite molecular sieves substituted with framework Sn atoms (Sn-CHA) was developed, which is required to predominantly incorporate Sn within the crystalline lattice. Quantitative titration with Lewis bases (NH3, CD3CN, and pyridine) demonstrates that framework Sn atoms behave as Lewis acid sites which catalyze intermolecular propionaldehyde reduction and ethanol oxidation as well as glucose–fructose isomerization. Aqueous-phase glucose isomerization turnover rates (per accessible Sn, 398 K) on Sn-CHA are four orders of magnitude lower than on Sn-Beta zeolites, but similar to those on amorphous Sn-silicates. Further analysis of Sn-CHA by dynamic nuclear polarization enhanced solid-state nuclear magnetic resonance (DNP NMR) spectroscopy enables measurement of 119Sn NMR chemical shift anisotropy (CSA) of Sn sites. Comparison of experimentally determined CSA parameters to those computed on cluster models using density functional theory supports the presence of closed sites (Sn-(OSi)4) and defect sites ((HO)-Sn-(OSi)3) adjacent to a framework Si vacancy), which respectively become hydrated hydrolyzed-open sites and hydrated defect sites when Sn-CHA is exposed to ambient conditions or aqueous solution. Kinetic and spectroscopic data show that large substrates (e.g., glucose) are converted only on Sn sites located within disordered mesoporous voids of Sn-CHA, which are selectively detected and quantified in IR and 15N and 119Sn DNP NMR spectra using pyridine titrants. This integrated experimental and theoretical approach allows precise description of the primary coordination and secondary confining environments of Sn active sites isolated in crystalline silica frameworks and establishes the role of confinement within microporous voids of Beta zeolites for aqueous-phase glucose isomerization catalysis.
Accurate and rapid point-of-care (PoC) diagnostics are critical to the control of the COVID-19 pandemic. The current standard for accurate diagnosis of SARS-CoV-2 is laboratory-based reverse ...transcription polymerase chain reaction (RT-PCR) assays. Here, a preliminary prospective performance evaluation of the QuantuMDx Q-POC SARS-CoV-2 RT-PCR assay is reported. Between November 2020 and March 2021, 49 longitudinal combined nose/throat (NT) swabs from 29 individuals hospitalised with RT-PCR confirmed COVID-19 were obtained at St George's Hospital, London. In addition, 101 mid-nasal (MN) swabs were obtained from healthy volunteers in June 2021. These samples were used to evaluate the Q-POC SARS-CoV-2 RT-PCR assay. The primary analysis was to compare the sensitivity and specificity of the Q-POC test against a reference laboratory-based RT-PCR assay. The overall sensitivity of the Q-POC test compared with the reference test was 96.88% (83.78- 99.92% CI) for a cycle threshold (Ct) cut-off value for the reference test of 35 and 80.00% (64.35-90.95% CI) without altering the reference test's Ct cut-off value of 40. The Q-POC test is a sensitive, specific and rapid PoC test for SARS-CoV-2 at a reference Ct cut-off value of 35. The Q-POC test provides an accurate option for RT-PCR at PoC without the need for sample pre-processing and laboratory handling, enabling rapid diagnosis and clinical triage in acute care and other settings.
At what age do infants understand that goals exist independently of the actions that result from them? Exploring infants' understanding of failed intentional actions--when the goal of the action is ...unfulfilled and thus not apparent in the actor's movements--is a critical step in answering this question. Using a visual habituation paradigm, we assessed when infants understand that a failed intentional action is goal directed and whether an understanding of successful intentional actions (actions that do overtly attain their goals) precedes an understanding of failed intentional actions. Results demonstrated that 10- and 12-month-olds recognized the goal directedness of both successful and failed reaching actions. Eight-month-olds also recognized the goal directedness of successful actions, but not of unsuccessful attempts. Thus, by the end of the 1st year of life, infants possess an impressive understanding ofintentional action, and an understanding of failed intentional actions follows an earlier understanding of successful ones.
In response to a physician shortage in Ethiopia, the number of medical students admitted to public universities was rapidly increased through a "flooding" policy.
To assess medical student ...perceptions on the impact of the "flooding" policy on medical education and e-learning initiatives, as well as plans for future emigration.
A cross-sectional survey of medical students at AAU was implemented in 2014. Attitude and practice items were assessed using a Likert scale. Logistic regression analysis was performed to identify characteristics associated with an interest in future emigration.
673 (99.6%) of 676 students approached completed the survey, representing 39.5% of all 1705 medical students enrolled at AAU in 2014. Most students felt the "flooding" policy had a negative impact on their medical education and >90% felt there was not adequate infrastructure to support the increased student body. E-learning activities to accommodate increased class size included distribution of electronic tablets, but at the time of the survey only 34.8% of students still had a working tablet and 82.3% reported problems with internet connectivity. Most preclinical students (85.1%) who had attended live-streamed lectures preferred traditional classroom lectures. Half of the students (49.5%) intended to practice medicine in Ethiopia. Independent risk factors for planning to emigrate included age <21 years (aOR = 1.30, 95% CI 1.04, 1.97); having applied to medical school for reasons other than "wanting to be a physician" (aOR = 1.55, 95% CI 1.14, 2.20), and not believing that "flooding" policy would increase the number of physicians working in Ethiopia (aOR = 1.87, 95% CI 1.33, 2.58).
The "flooding" policy lead to significant educational challenges that were not fully alleviated by e-learning initiatives. Concomitant increases in resources for infrastructure development and faculty expansion are needed to maintain quality medical education. Additional research is needed on factors that influence medical graduates decision to emigrate.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Artificial surfaces in coastal waters and offshore oceans, including boat hulls, docks, and offshore structures, are invariably colonized, or fouled, by a host of sessile species known collectively ...as fouling communities. Fouling has great economic impacts on shipping and other marine industries and plays an important role in the spread of marine invasive species across the globe. The main strategy to prevent fouling of artificial surfaces is application of antifouling coatings containing varying concentrations and mixtures of biocides. Presently, copper and zinc are popular antifouling biocides, and the latter is gaining in usage due to the known toxic characteristics of copper in the marine environment and consequent regulation and consumer opinion. Nanomaterials, including Cu and ZnO nanoparticles, have been explored as a way to efficiently deliver biocides from coating matrices. Here, we examine the efficacy and biocide release characteristics of several copper- and zinc-based antifouling coatings, including formulations containing traditional micron-sized Cu and ZnO particles and two containing copper and ZnO nanoparticles, respectively. Most of the antifouling coatings tested significantly reduced the abundance and biodiversity of the fouling community in the three study locations across California. Invasive species were suppressed by most coatings at similar levels to natives, suggesting that in general, antifouling coatings do not favor invasive species. We found that zinc-based antifouling coatings were similar and in some cases better performing than copper, despite the generally lower toxicity of zinc to aquatic organisms compared with copper. The performance of zinc-based coatings, moreover, was not directly related to the amount of zinc released into the water or their zinc content. Nano-based coatings did not offer any clear advantages over non-nano coatings, either in the degree of Zn leaching or fouling suppression. Coating matrix properties clearly are an important factor affecting the efficacy and biocide leaching rate of antifouling coatings.
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