Emerging complexity in the self-dual theory of superconductivity.

To describe the way complexity emerges in seemingly simple systems of nature, requires one to attend to two principal questions: how complex patterns appear spontaneously and why a single system can accommodate their inexhaustible variety. It is commonly assumed the pattern formation phenomenon is related to the competition of several types of interactions with disparate length scales. These multi-scale interactions also lead to frustration within the system, resulting in the existence of a manifold of configurations-patterns with qualitatively distinct morphologies. This work explores an alternative approach through a mechanism that leads to a wide range of intricate and topologically non-trivial patterns. The mechanism is described by the self-dual Ginzburg-Landau theory and, possibly, other Maxwell-Higgs models. It gives rise to unique spatial flux and condensate spatial profiles observed in superconductors between the two conventional superconductivity types I and II.

Comparison of 3 supraspinatus tendon repair techniques - a 3D computational finite element analysis.

Considering that optimal contact area and pressure at the tendon-bone interface are associated with better footprint repair and outcomes, the aim of this study was to compare the performance of standard double-row, transosseous equivalent (TOE), and partial articular supraspinatus tendon avulsion (PASTA) techniques for the treatment of full-thickness tears of the supraspinatus tendon using 3D finite element models. Loading consisted, alternately, in a preloading of 10 N and 20 N of the sutures. The footprint coverage of the standard double-row, TOE, and PASTA techniques was estimated to represent 19%, 30%, and 35%, respectively, of the repair area. The average contact pressures followed an opposite trend, i.e., the largest was estimated for the standard double-row technique, whereas the lowest was estimated for the PASTA technique. Despite the present study advancing the computational modelling of rotator cuff repair, and the results being consistent with the literature, its findings must be evaluated cautiously, bearing in mind its limitations.

Primary stability analysis of stemless shoulder implants.

Although the primary stability of joint implants is fundamental for successful osseointegration, little is know about this issue in the context of stemless shoulder implants. Considering 3D finite element models, the purpose of this study was to evaluate the primary stability of five stemless designs, based on the Sidus, SMR, Simpliciti, Eclipse, and Global Icon stemless systems. Three alternative bone quality conditions were considered for cancellous bone. For the Sidus, SMR, and Simpliciti designs, which do not possess a collar that sits on the cortical rim of the humeral resected surface, contact and no contact conditions were considered between the bone surface and the humeral head components. Micromotions at bone-implant interfaces promoting osseointegration were computed as a measure of primary stability for eight load cases consisting of peak in vivo joint loads measured during selected upper limb activities. Under good bone quality conditions, all stemless designs presented micromotions below 150 µm. The Eclipse-based and Global-Icon based designs were the least sensitive to bone quality. Stemless designs presenting a solid collar or contact between the humeral head component and bone provided more stability. Overall, the Eclipse-based and Global Icon-based designs presented the best performance from the primary stability point of view. However, if bone adaptation data available in the literature are considered along with the primary stability data computed here, the Global Icon-based design, as well as other designs, might be considered superior long-term options due to their better compromise between primary stability and impact on bone adaptation.

Bone remodelling of the humerus after a resurfacing and a stemless shoulder arthroplasty.

BACKGROUND: New implant designs, such as resurfacing and stemless implants, have been developed to improve the long-term outcomes of the shoulder arthroplasty. However, it is not yet fully understood if their influence on the bone load distribution can compromise the long-term stability of the implant due to bone mass changes. Using three-dimensional finite element models, the aim of the present study was to analyse the bone remodelling process of the humerus after the introduction of resurfacing and stemless implants based on the Global C.A.P. and Sidus Stem-Free designs, respectively. METHODS: The 3D geometric model of the humerus was generated from the CT data of the Visible Human Project and the resurfacing and stemless implants were modelled in Solidworks. Considering a native humerus model, a humerus model with the resurfacing implant, and a humerus model with the stemless implant, three finite element models were developed in Abaqus. Bone remodelling simulations were performed considering healthy and poor bone quality conditions. The loading condition considered comprised 6 load cases of standard shoulder movements, including muscle and joint reaction forces estimated by a multibody model of the upper limb. FINDINGS: The results showed similar levels of bone resorption for the resurfacing and stemless implants for common humeral regions. The regions underneath the head of the resurfacing implant, unique to this design, showed the largest bone loss. For both implants, bone resorption was more pronounced for the poor bone quality condition than for the healthy bone quality condition. INTERPRETATION: The stemless implant lost less density at the fixation site, which might suggest that these implants may be better supported in the long-term than the resurfacing implants. However, further investigation is necessary to allow definite recommendations.

Osteochondritis Dissecans of the Capitellum: A Case Report of Successful Arthroscopic Treatment.

Introduction. Osteochondritis dissecans (OCD) of the capitellum is a localized disorder of the subchondral bone, in a region with limited healing capacity. Although its aetiology is still unknown, it has been associated with repetitive microtrauma. The natural history of this disease involves the evolution for degenerative joint disease in approximately half of the patients, with early identification and treatment being critical to optimizing the outcome. Case Presentation. We present a rare case in our practice, illustrating a capitellar OCD in a fifteen-year-old White male without an identified cause of repetitive microtrauma. Conclusion. In this case prompt diagnosis and arthroscopic-assisted treatment led to a successful result.

Full-thickness tears of the supraspinatus tendon: A three-dimensional finite element analysis.

Knowledge regarding the likelihood of propagation of supraspinatus tears is important to allow an early identification of patients for whom a conservative treatment is more likely to fail, and consequently, to improve their clinical outcome. The aim of this study was to investigate the potential for propagation of posterior, central, and anterior full-thickness tears of different sizes using the finite element method. A three-dimensional finite element model of the supraspinatus tendon was generated from the Visible Human Project data. The mechanical behaviour of the tendon was fitted from experimental data using a transversely isotropic hyperelastic constitutive model. The full-thickness tears were simulated at the supraspinatus tendon insertion by decreasing the interface area. Tear sizes from 10% to 90%, in 10% increments, of the anteroposterior length of the supraspinatus footprint were considered in the posterior, central, and anterior regions of the tendon. For each tear, three finite element analyses were performed for a supraspinatus force of 100N, 200N, and 400N. Considering a correlation between tendon strain and the risk of tear propagation, the simulated tears were compared qualitatively and quantitatively by evaluating the volume of tendon for which a maximum strain criterion was not satisfied. The finite element analyses showed a significant impact of tear size and location not only on the magnitude, but also on the patterns of the maximum principal strains. The mechanical outcome of the anterior full-thickness tears was consistently, and significantly, more severe than that of the central or posterior full-thickness tears, which suggests that the anterior tears are at greater risk of propagating than the central or posterior tears.

Computational reverse shoulder prosthesis model: Experimental data and verification.

The reverse shoulder prosthesis aims to restore the stability and function of pathological shoulders, but the biomechanical aspects of the geometrical changes induced by the implant are yet to be fully understood. Considering a large-scale musculoskeletal model of the upper limb, the aim of this study is to evaluate how the Delta reverse shoulder prosthesis influences the biomechanical behavior of the shoulder joint. In this study, the kinematic data of an unloaded abduction in the frontal plane and an unloaded forward flexion in the sagittal plane were experimentally acquired through video-imaging for a control group, composed of 10 healthy shoulders, and a reverse shoulder group, composed of 3 reverse shoulders. Synchronously, the EMG data of 7 superficial muscles were also collected. The muscle force sharing problem was solved through the minimization of the metabolic energy consumption. The evaluation of the shoulder kinematics shows an increase in the lateral rotation of the scapula in the reverse shoulder group, and an increase in the contribution of the scapulothoracic joint to the shoulder joint. Regarding the muscle force sharing problem, the musculoskeletal model estimates an increased activity of the deltoid, teres minor, clavicular fibers of the pectoralis major, and coracobrachialis muscles in the reverse shoulder group. The comparison between the muscle forces predicted and the EMG data acquired revealed a good correlation, which provides further confidence in the model. Overall, the shoulder joint reaction force was lower in the reverse shoulder group than in the control group.

Long head of biceps: from anatomy to treatment.

The long head of the biceps (LHB), tendinous structure of the proximal brachial biceps, has its well-known anatomy, which contrasts with its current functional characterization. Various forms of proximal anchor and intra-articular route, important for the correct interpretation of its contribution to the pathology of the shoulder as well as the treatment methodology, are described. Knowledge of its biomechanics results mainly from cadaveric studies that contradict each other. Already the few studies in vivo indicate a depressant and stabilizing action, anterior, for the humeral head. Its pathology is rarely isolated because it is almost always correlated with rotator cuff or labrum pathology. It can be divided into 3 major groups (inflammatory, instability and traumatic) and subdivided according to its location. The anterior shoulder pain is the initial symptom of pathology of LHB Its perfect characterization is dependent on the associated injuries. Clinical tests are multiple and only their combination allows better sensitivity and specificity for LHB pathology. The arthro-MRI and dynamic ultrasound are able to increase proper diagnostic of the pathology of LHB. Treatment ranges from conservative and surgical. The latter includes the repair, tenotomy and tenodesis of LHB which can be performed by open or arthroscopic methodology. The author intends to review existing literature on all aspects related to the long head of the biceps from anatomy to treatment, presenting the latest results.

Reorganization of lipid domain distribution in giant unilamellar vesicles upon immobilization with different membrane tethers.

Characterization of phase coexistence in biologically relevant lipid mixtures is often carried out through confocal microscopy of giant unilamellar lipid vesicles (GUVs), loaded with fluorescent membrane probes. This last analysis is generally limited to the vesicle hemisphere further away from the coverslip, in order to avoid artifacts induced by the interaction with the solid surface, and immobilization of vesicles is in many cases required in order to carry out intensity, lifetime or single-molecule based microscopy. This is generally achieved through the use of membrane tethers adhering to a coverslip surface. Here, we aimed to determine whether GUV immobilization through membrane tethers induces changes in lipid domain distribution within liposomes displaying coexistence of lipid lamellar phases. Confocal imaging and a Förster resonance energy transfer (FRET) methodology showed that biotinylated phospholipids present significantly different membrane phase partition behavior upon protein binding, depending on the presence or absence of a linker between the lipid headgroup and the biotinyl moiety. Membrane phases enriched in a membrane tether displayed in some cases a dramatically increased affinity for the immobilization surface, effectively driving sorting of lipid domains to the adherent membrane area, and in some cases complete sequestering of a lipid phase to the interaction surface was observed. On the light of these results, we conclude that tethering of lipid membranes to protein surfaces has the potential to drastically reorganize the distribution of lipid domains, and this reorganization is solely dictated by the partition properties of the protein-tether complex.

Impact assessment in living kidney donation: psychosocial aspects in the donor.

BACKGROUND: Living donor kidney transplantation has a positive influence on graft survival and recipient quality of life (QoL). We assessed the psychosocial impact of donation to the donor. METHODS: Before and after the procedure 32 living kidney donors (mean age 41 years) completed the Zung Self-Rating Anxiety and Depression Scales; a Sociodemographic, Short-Form 36 Health Survey (SF-36), and a Donation Perceptions Questionnaire. RESULTS: Living kidney donors were siblings (62.5%), parents (34.4%), or a daughter (3.1%). Transplantation was not successful in two cases: one recipient death and one graft failure. No significant changes were observed in donor QoL except for the SF-36 social functioning subscale that showed significant improvement after donation (P = .038). A reduction in depression symptom frequency was verified after donation (from 65.6% to 46.9%). There was an almost significant decrease in depression scores (P = .077), which was in fact was significant when one considered only successful transplants (P = .021). There was no significant variation in anxiety scores among donors. Time since transplantation was inversely correlated with overall anxiety (r = .443, P = .011), and with somatic anxiety subscales (r = .357, P = .045). For most donors, the decision to donate was easy and spontaneous. Nearly all donors would donate again and strongly encourage others to donate. CONCLUSIONS: Except for the social functioning scale that improved, no significant changes were observed in QoL of living kidney donors after the procedure. Depression scores significantly decreased after donation, but anxiety scores remained stable. Donors, who were mostly siblings, showed positive perceptions about donation, did not regret their decision, and strongly recommend it to others.

[Epilepsy, epileptics, the work: conflicting relations]. / A epilepsia, o epiléptico e o trabalho: relações conflitantes.

Participation in the workplace by people with epilepsy is conditioned by various interrelated issues concerning epilepsy itself, the epileptic individual, and society's implicit cultural codes. In order to analyze how such conflictive participation interferes decisively in the quality of life of people with epilepsy, a survey was conducted with 339 patients at the University Hospital of Universidade Federal Fluminense. Patients answered questionnaires including level of schooling, professional qualifications, employment situation, frequency, type, and duration of seizures, associated phenomena, and prejudice towards epilepsy. We observed that satisfactory management of seizures is decisive for their success at work. All patients with daily seizures and 9.3% of those with weekly seizures had never been employed. We conclude that any intervention in this context must include the implementation of multiprofessional and intersectorial therapeutic programs and legislation to protect epileptic patients' rights in a broad effort at demystification of epilepsy.

Misoprostol embryotoxicity: clinical evaluation of fifteen patients with arthrogryposis.

We report on clinical evaluations of Brazilian patients with misoprostol-induced arthrogryposis. All 15 patients had growth retardation, underdeveloped bones, short feet with equinovarus, rigidity of several joints with skin dimples and webs, decreased movement of legs stemming from neurologic impairment, bilateral symmetrical hypoplasia or atrophy of limb muscles, and absent tendon reflexes. Of the 15 patients, five had upper limb deformities in addition to lower limb involvement, and one had spinal cord disruption leading secondarily to segmental sensory loss and neurogenic bladder and bowel. Electroneuromyography of five patients indicated that the abnormalities were of neurogenic origin and suggestive of anterior horn cell defects. All of their mothers took 400-4,800 mcg of misoprostol orally or vaginally at 8 to 12 weeks of pregnancy. Our observations support a previously stated caution with regard to the embryotoxicity of misoprostol.

Seizures in Chédiak-Higashi syndrome. Case report.

Chédiak-Higashi syndrome is a rare hematological disease characterized by increased fusion of cytoplasmatic granules. Neurological symptoms occur in approximately half of the patients. We describe the clinical, eletrophysiological, hematological and radiological findings in a girl who had Chédiak-Higashi syndrome and seizures.

Liquid-liquid extraction of a recombinant protein, cytochrome b5, with aqueous two-phase systems of polyethylene glycol and potassium phosphate salts.

The partitioning of cytochrome b5 in aqueous two-phase systems of polyethylene glycol (PEG) and potassium phosphate salts was investigated. Cytochrome b5 partitioning is enhanced with decreasing polymer molecular mass and with increasing tieline length and pH. The effect of cytochrome b5 mutation, by substitution of the glutamic acid at positions 56 and 92 of the polypeptide chain by a lysine, on protein partitioning was also studied. Partitioning of cytochrome b5 mutants shows the same dependence on tieline length and pH, following the order cytochrome b5 > mutant 56 > mutant 92.