2,227 research outputs found
Anatomy of sartorius muscle
A sartorius muscle is the longest muscle of the human system. It runs over 2 joints— hip and knee joints. In the study 10 sartorius muscles were examined. They were dissected free of lower human limbs. Dimensions of limbs which these muscles come from and dimensions of the muscles and their component parts were examined. The attention was paid mainly to parts of tendon located inside the muscle belly. The results show that they are either of a comparable length (distal tendon) or several times longer (proximal tendon) than visible parts located outside of the muscle. Moreover, a complex structure of the distal tendon which includes 2 tracts of different places of insertion was stated. Inferior tract inserted in the same place as muscle tendons: semitendinosus and gracilis. The superior tract inserted transversely against the former one. The tendon of the sartorius muscle forms additionally an aponeurosis whose fibres enter into the deep fascia of crus. The muscle belly is characterised with various width on different levels of its length. In half of casess word-like distal segment of belly is formed
Anatomy of the long peroneal muscle of the leg
Background: The aim of the work was to perform a morphometric analysis of the long peroneal muscle (LPM) of the leg and explore the relationship between muscle belly and tendon.
Materials and methods: Ten lower limbs (8 right and 2 left) were fixed in formaldehyde and dissected using standard technique. The LPM was exposed from the proximal attachment to the top of a lateral malleolus.
Results: The tendon was subsequently freed and various measurements were taken. The tendon of the LPM enters deep into the muscle belly. Muscle fibres surround the tendon and descend as far down as 4 cm above the lateral malleolus. Muscle fibres insert mainly along posterior border of the tendon and on its medial surface, leaving lateral surface only partly covered.
Conclusions: The LPM contains a long intramuscular segment of the tendon and area of the musculotendinous junction varies along the LPM. It makes the idea of uniform pennation pattern of the LPM unlikely
Tunneling-percolation origin of nonuniversality: theory and experiments
A vast class of disordered conducting-insulating compounds close to the
percolation threshold is characterized by nonuniversal values of transport
critical exponent t, in disagreement with the standard theory of percolation
which predicts t = 2.0 for all three dimensional systems. Various models have
been proposed in order to explain the origin of such universality breakdown.
Among them, the tunneling-percolation model calls into play tunneling processes
between conducting particles which, under some general circumstances, could
lead to transport exponents dependent of the mean tunneling distance a. The
validity of such theory could be tested by changing the parameter a by means of
an applied mechanical strain. We have applied this idea to universal and
nonuniversal RuO2-glass composites. We show that when t > 2 the measured
piezoresistive response \Gamma, i. e., the relative change of resistivity under
applied strain, diverges logarithmically at the percolation threshold, while
for t = 2, \Gamma does not show an appreciable dependence upon the RuO2 volume
fraction. These results are consistent with a mean tunneling dependence of the
nonuniversal transport exponent as predicted by the tunneling-percolation
model. The experimental results are compared with analytical and numerical
calculations on a random-resistor network model of tunneling-percolation.Comment: 13 pages, 12 figure
Morphology and morphometry of the semitendinosus distal tendon in adults and foetuses
Background: The distal tendon of the semitendinosus is often used as a graft in orthopedic reconstructive surgery. Knowledge of the exact morphology of this tendon, and also the ability to predict its morphometric data are certainly helpful when planning the procedure of surgery. Comparison of the semitendinosus distal tendon anatomy in adults and foetuses may be scientifically relevant. There are no scientific reports on this tendon anatomy in foetuses.
Materials and methods: Seventy semitendinosus muscles from cadavers were obtained using standard dissection techniques (50 muscles were obtained from adults and 20 from foetuses). Moreover, ultrasound examinations of 20 muscles were performed in living individuals.
Results: Two main parts of the distal tendon were distinguished — the external part not covered with muscle fibres and the internal part, which is partially or entirely hidden within the muscle belly (venter). The average length of the distal tendon was 32.34 cm, while the average lengths of the external and internal parts were 9.65 cm and 12.59 cm, respectively. The external part was solid and cylindrical. The internal part was flat and rolled like a trough, thus making the tendon a poor transplant material. Similarly, the distal tendon in foetuses consisted of two parts, including the external and internal part.
Conclusions: The proportions between the lengths of different muscle parts were very similar in adults and foetuses
Breakup of finite-size liquid filaments: Transition from no-breakup to breakup including substrate effects
This work studies the breakup of finite-size liquid filaments, when also
including substrate effects, using direct numerical simulations. The study
focuses on the effects of three parameters: Ohnesorge number, the ratio of the
viscous forces to inertial and surface tension forces, the liquid filament
aspect ratio, and where there is a substrate, a measure of the fluid slip on
the substrate, i.e. slip length. Through these parameters, it is determined
whether a liquid filament breaks up during the evolution toward its final
equilibrium state. Three scenarios are identified: a collapse into a single
droplet, the breakup into one or multiple droplets, and recoalescence into a
single droplet after the breakup (or even possibly another breakup after
recoalescence). The results are compared with the ones available in the
literature for free-standing liquid filaments. The findings show that the
presence of the substrate promotes breakup of the filament. The effect of the
degree of slip on the breakup is also discussed. The parameter domain regions
are comprehensively explored when including the slip effects. An experimental
case is also carried out to illustrate the collapse and breakup of a
finite-size silicon oil filament supported on a substrate, showcasing a
critical length of the breakup in a physical configuration. Finally, direct
numerical simulations reveal striking new details into the breakup pattern for
low Ohnesorge numbers, where the dynamics are fast and the experimental imaging
is not available; our results therefore significantly extend the range of
Ohnesorge number over which filament breakup has been considered
Self-reported quality care for knee osteoarthritis: comparisons across Denmark, Norway, Portugal and the UK
Objectives: To assess and compare patient perceived quality of osteoarthritis (OA) management in primary healthcare in Denmark, Norway, Portugal and the UK. Methods: Participants consulting with clinical signs and symptoms of knee OA were identified in 30 general practices and invited to complete a cross-sectional survey including quality indicators (QI) for OA care. A QI was considered as eligible if the participant had checked 'Yes' or 'No', and as achieved if the participant had checked 'Yes' to the indicator. The median percentage (with IQR and range) of eligible QIs achieved by country was determined and compared in negative binominal regression analysis. Achievement of individual QIs by country was determined and compared using logistic regression analyses. Results: A total of 354 participants self-reported QI achievement. The median percentage of eligible QIs achieved (checked 'Yes') was 48% (IQR 28%, 64%; range 0-100%) for the total sample with relatively similar medians across three of four countries. Achievement rates on individual QIs showed a large variation ranging from 11% (referral to services for losing weight) to 67% (information about the importance of exercise) with significant differences in achievement rates between the countries. Conclusions: The results indicated a potential for improvement in OA care in all four countries, but for somewhat different aspects of OA care. By exploring these differences and comparing healthcare services, ideas may be generated on how the quality might be improved across nations. Larger studies are needed to confirm and further explore the findings.EULAR Health Professional Grant; Norwegian Fund through the FYSIOPRIM project; National Institute for Health Research (NIHR) [RP-PG-0407-10 386]; Arthritis Research UK Centre in Primary Care grant [18139]; National Institute for Health Research (NIHR) Collaborations for Leadership in Applied Health Research and Care West Midlands by a Knowledge Mobilisation Research Fellowship from the National Institute for Health Research; National Institute for Health Research (NIHR); Fundacao para a Ciencia e Tecnologia [PEst-OE/MAT/UI0006/2014]info:eu-repo/semantics/publishedVersio
Daily sunshine hours as determinant of 25-hydroxyvitamin D concentration among diabetic cardiac patients who experienced myocardial infarction hospitalized due to acute coronary syndrome: a cross-sectional study
Wstęp. Niedobór witaminy D jest problemem ogólnoświatowym o różnych konsekwencjach zdrowotnych. Witamina D może obniżać ryzyko niewydolności serca, jednak dowody świadczące o skuteczności suplementacji witaminą D na utrzymanie zdrowia układu sercowo-naczyniowego są sprzeczne z powodu braku odpowiedniej liczby i jakości badań klinicznych. Przyczyny braku jednoznacznych efektów potwierdzających pozytywny wpływ suplementacji witaminy D mogą być co najmniej trzy: 1) suplementacja zbyt małą ilością witaminy D lub 2) brak włączenia do badania tylko populacji z ciężkim niedoborem witaminy D, lub 3) czas trwania suplementacji. Celem pracy była charakterystyka grupy pacjentów kardiologicznych, u których stwierdzono w poprzednich badaniach najniższe stężenia 25-hydroksywitaminy D [25(OH)D].Materiał i metody. Analizie poddano wyniki 92 chorych kardiologicznych z cukrzycą w wieku 41–89 lat, którzy przeżyli zawał serca z istotnymi zmianami w tętnicach wieńcowych, hospitalizowanych z powodu ostrego zespołu wieńcowego, mieszkających w Warszawie.Wyniki. Mediana stężenia 25(OH)D w badanej populacji wyniosła 11 ng/ml (zakres: 4–28 ng/ml). Jedynym istotnym determinantem stężenia 25(OH)D był okres badania; stężenie było wyższe latem niż zimą.Wnioski. Leczenie witaminą D u polskich pacjentów kardiologicznych w celu osiągnięcia optymalnego stężenia, tj. 30 ng/ml (75 nmol/l), wydaje się konieczne i powinno być jak najszybciej wdrożone.Introduction. Vitamin D deficiency is a worldwide problem with a variety of health consequences. Vitamin D may reduce the risk of heart failure, however, evidence of the impact of vitamin D treatment on maintenance of cardiovascular health (i.e., preventing cardiovascular diseases) is conflicting due to lack of support from clinical trials. The reason for the failure of clinical trials to confirm an effect of vitamin D supplementation could be at least threefold: 1) too little vitamin D given to the participants or 2) lack of inclusion of only severely vitamin D-deficient populations or 3) study duration. The aim of this study was to characterize a group of cardiac patients who presented the lowest concentrations of 25-hydroxyvitamin D [25(OH)D].
Material and methods. Results of 92 diabetic cardiac patients aged between 41 and 89 years who experienced myocardial infarction, with significant coronary arteries changes, hospitalized due to acute coronary syndrome living in
Warsaw were analyzed.
Results. Patients presented median 25(OH)D concentration value of 11 ng/mL (range: 4–28 ng/mL). The only significant determinant of 25(OH)D concentration was the date of examination, with higher concentrations in summer than in winter.
Conclusions. Vitamin D treatment in Polish cardiac patients aimed at reaching the optimal level of 30 ng/mL (75 nmol/L) seems to be necessary and implemented as soon as possible
The cranio-orbital foramen; a meta-analysis with a review of the literature
Background: The goal of the present study was to provide accurate data on the prevalence and morphometrical aspects of the cranio-orbital foramen (COF), which can surely be of use by surgeons performing procedures on the lateral orbit. Furthermore, the embryology and the clinical significance of this osseous structure were thoroughly discussed.
Materials and methods: Major online medical databases such as PubMed, Scopus, Embase, Web of Science, and Google Scholar were searched to find all relevant studies regarding COF.
Results: Eventually, a total of 25 studies that matched the required criteria and contained complete and relevant data were included in this meta-analysis. The pooled prevalence of COF was found to be 48.37% (95% CI: 41.67% - 55.10%). The occurrence of the COF unilaterally was set to be 71.92% (95% CI: 41.87% - 96.97%). The occurrence of the COF bilaterally was set at 26.08% (95% CI: 3.03% - 58.13%).
Conclusions: In conclusion, we believe that this is the most accurate and up-to-date study regarding the anatomy of the COF. The COF is prevalent in 48.37% of the cases, and it is most frequently unilateral (73.92%). Furthermore, the prevalence of accessory COFs was found to be 16.72 percent. The presence of these foramina may represent a source of hemorrhage that ophthalmic surgeons should be aware of when performing procedures in the lateral part of the orbit
Dimensionality of Carbon Nanomaterials Determines the Binding and Dynamics of Amyloidogenic Peptides: Multiscale Theoretical Simulations
Experimental studies have demonstrated that nanoparticles can affect the rate of protein self-assembly, possibly interfering with the development of protein misfolding diseases such as Alzheimer's, Parkinson's and prion disease caused by aggregation and fibril formation of amyloid-prone proteins. We employ classical molecular dynamics simulations and large-scale density functional theory calculations to investigate the effects of nanomaterials on the structure, dynamics and binding of an amyloidogenic peptide apoC-II(60-70). We show that the binding affinity of this peptide to carbonaceous nanomaterials such as C60, nanotubes and graphene decreases with increasing nanoparticle curvature. Strong binding is facilitated by the large contact area available for π-stacking between the aromatic residues of the peptide and the extended surfaces of graphene and the nanotube. The highly curved fullerene surface exhibits reduced efficiency for π-stacking but promotes increased peptide dynamics. We postulate that the increase in conformational dynamics of the amyloid peptide can be unfavorable for the formation of fibril competent structures. In contrast, extended fibril forming peptide conformations are promoted by the nanotube and graphene surfaces which can provide a template for fibril-growth
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