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In brief: We studied 407 volleyball players to investigate the factors that cause patellar or quadriceps tendinitis (jumper's knee). Athletes from 30 teams in various divisions of the Italian Volleyball Federation championship were interviewed personally or by questionnaire. Factors investigated included age and sex, years of play, frequency of training sessions and games, type of playing surface, and type of training. The results showed that symptoms occurred most often among athletes playing five times a week or more and among those playing on hard surfaces, such as cement. Age, sex, years of play, and type of training were less significant factors.

Jumper's knee (patellar or quadriceps tendon tendon itis) is found in a high number of athletes, especially in volleyball and basketball players. Conservative treatment (rest, stretching, physical therapy and an tiinflammatory drugs) is usually successful. The ath letes often recover completely and resume their sports activity. The purpose of this study is to present the histologic findings and our surgical repair of 18 knees of patients who underwent surgery after failure of conservative treatment. Histologic findings confirm that the so-called "jumper's knee" is a pathology localized at the bone- tendon junction. In all cases the following abnormali ties were found:pseudocystic cavities at the borderline between mineralized fibrocartilage and bone, disap pearance of the "blue line," increased thickness of the insertional fibrocartilage with myxomatous and hyaline metaplasia, mineralization, and ossification of the fibrocartilage far from the "blue line." Abnormali ties of the patellar tendon were observed only in one patient who received local injection of corticosteroids. Eleven of the 18 surgically treated knees obtained a satisfactory result with complete resumption of sports activity.

Background The all-inside graft-link technique for anterior cruciate ligament reconstruction is performed with two cortical suspension devices with adjustable loops on both femur and tibia. This technique requires meticulous graft preparation. The aim of this study was to biomechanically test three different graft configurations resulting from differences in initial graft length. Materials and methods Thirty bovine digital extensor tendons were arranged in three different ways: “half-quadrupled”, “tripled” and “quadrupled”. The final graft length was 65–75 mm. The specimens were fixed vertical to the loading axis of a tensile testing machine. After a static pre-conditioning of 50 N for 5 min, a load to failure test was performed and data regarding the ultimate failure load (UFL), the stiffness and mode of failure were recorded. Results The evaluation of UFL showed a significant differences between group means as determined by one-way analysis of variance (F = 21.92, p = 0.002). Post hoc comparisons showed a significantly better UFL of “tripled” (p = 0.007) and “quadrupled” preparations (p = 0.014) compared to the “half-quadrupled” configuration, with no significant differences between “tripled” and “quadrupled” grafts (p = 0.061). No significant differences were found when evaluating the stiffness between the groups. Failure occurred by tendon slippage across the suture in all specimens. Conclusion The “quadrupled” tendon achieved the best UFL, with even the “tripled” configuration having sufficient biomechanical characteristics to withstand the loads experienced during early rehabilitation. For this reason, with a total semitendinosus length of less than 260 mm it could be better to “triple” instead of “half-quadruple” it to achieve better performance of the graft.

Jumper's knee is a typical functional overload injury because it affects those athletes who submit their knee extensor mechanisms to intense and repeated stress, e.g. volleyball and basketball players, high and long jumpers. According to the classification of Perugia and colleagues, it is an insertional tendinopathy affecting, in order of frequency, the insertion of the patellar tendon into the patella (65% of cases), attachment of the quadriceps tendon to the patella (25%) and the attachment of the patellar tendon to the tibial tuberosity (10%). The frequent occurrence of this injury in athletes led to the study of factors that may contribute to its onset and aggravation. These factors are divided into extrinsic (i.e. kind of sport practised and training methods used) and intrinsic (i.e. connected with the somatic and morphological characteristics of the athletes). On the basis of our experience and after a review of the literature it appears, contrary to what has been repeatedly claimed in the past, the extrinsic factors are more important than the intrinsic in the aetiology of jumper's knee. The effect of traumatic incidents and use of elastic kneecap guards should also be considered negligible. The intrinsic causes of jumper's knee, can be sought in the mechanical properties of tendons (resistance, elasticity and extensibility) rather than in morphological or biomechanical abnormalities of the knee extensor mechanism.

Sixty-two athletes whose injured knees had negligible instability were found to have an absent or functionless anterior cruciate ligament (ACL) at the time of medial meniscectomy. After a mean of 52 months of followup, 51 patients were examined; 24 (47%) had returned to full sports activities, whereas 27 (53%) acknowledged incidents of the knee "giving way" or having completely given up sports because of instability. By analyzing the following variables, the jerk test, the type of meniscal lesion, and the type of sports engaged, we formulated a rating system to be used intraopera tively for determining the need for combining meniscec tomy with a ligament reconstruction.

A study of 75 patients was performed to assess the accuracy of arthroscopy carried out for clinical diagnosis of meniscal tear. In these patients, arthroscopy did not detect any intraarticular pathology that could explain the preoperative symptoms. Of the 75 patients, seven were subsequently reoperated on, but in 68 the typical symptoms of meniscal tear improved after the diagnostic arthroscopy.

Twenty patients had undergone arthroscopic meniscectomy for medial bucket-handle meniscal tears. Half had undergone meniscectomy with central approach, and half had been treated by anterolateral technique. Isokinetic evaluation, with a Cybex II isokinetic dynamometer, was done preoperatively and at 14 and 28 days postoperatively. Two weeks after operation, there was only a slight and insignificant decrease of quadriceps function with the central approach as compared with the anterolateral. However, at 4 weeks, no differences were shown between the two portals. The flexor muscles generally recovered more rapidly with the central technique.

We have reviewed the clinical records and the results of conservative and surgical treatment of 125 out of 172 cases of Jumper's Knee followed for at least 2 years since the onset of symptoms. All were athletes involved in various sporting activities. At follow up 15 patients had given up sport and the lesion had healed spontaneously. We used the classification of Blazina et al as modified by Roels et al. Twenty-four patients were in stage 1, 42 in stage 2, 43 in stage 3 and one in stage 4. Conservative treatment was used primarily on all patients with one exception where the tendon had ruptured. The results were very good in 42, good in 32, and poor in 43, but in 36 patients a long period of rest and reduction in sporting activity was necessary before a significant improvement was obtained. Operation was carried out on 16 patients (19 knees), 18 were in stage 3 and one in stage 4. Various surgical techniques were used. The results were very good in 7 knees, good in 5 and poor in 7. Operation is indicated after the failure of conservative measures and in patients who do not want to reduce their sporting level. The aim should be to induce healing at the bone tendon junction. We emphasize the importance of the prevention of jumper's knee in athletes.

Energy functionals which depend explicitly on orbital densities, rather than on the total charge density, appear when applying self-interaction corrections to density-functional theory; this is, e.g., the case for Perdew-Zunger and Koopmans-compliant functionals. In these formulations the total energy is not invariant under unitary rotations of the orbitals, and local, orbital-dependent potentials emerge. We argue that this is not a shortcoming, and that instead these potentials can provide, in a functional form, a simplified quasiparticle approximation to the spectral potential, i.e., the local, frequency-dependent contraction of the many-body self-energy that is sufficient to describe exactly the spectral function. As such, orbital-density-dependent functionals have the flexibility to accurately describe both total energies and quasiparticle excitations in the electronic-structure problem. In addition, and at variance with the Kohn-Sham case, orbital-dependent potentials do not require nonanalytic derivative discontinuities. We present numerical solutions based on the frequency-dependent Sham-Schlüter equation to support this view, and examine some of the existing functionals in this perspective, highlighting the very close agreement between exact and approximate orbital-dependent potentials. © 2014 American Physical Society.

We report a theoretical scheme that enables the calculation of maximally localized Wannier functions within the formalism of projector-augmented waves (PAW), which also includes the ultrasoft pseudopotential (USPP) approach. We give a description of the basic underlying formalism and explicitly write out all the required matrix elements using the common ingredients of the PAW/USPP theory. We report an implementation of the method in a form suitable for accepting the input electronic structure from USPP plane-wave DFT simulations. We apply the method to the calculation of Wannier functions, dipole moments and spontaneous polarizations for a range of test cases. A comparison with norm-conserving pseudopotentials is reported as a benchmark.

In this study we evaluated the role of the anterior cruciate ligament (ACL) and its secondary restraint in controlling knee stability using a navigation system. The purpose of this study was to evaluate the kinematics of the knee in different conditions of instability: ACL intact, after transection of the posterolateral (PL) bundle, after transection of the anteromedial (AM) bundle, and after lesion of the anterolateral femorotibial ligament (ALFTL). Anterior tibial translation and rotation were measured with a computer navigation system in 6 knees in whole fresh-frozen human cadavers by use of a manual maximum load. Anterior translation was evaluated at 30°, 60°, and 90° of flexion; rotation at 0°, 15°, 30°, 45°, 60°, and 90° of flexion. Cutting the PL bundle does not increase anterior translation and rotation of the knee. Cutting the AM bundle significantly increased the anteroposterior (AP) translation at 30° and 60° of flexion ( P =.01), but does not increase rotation of the knee. Cutting the ALFTL increased anterior translation at 60° of flexion ( P =.04) and rotation at 30°, 45°, and 60° of flexion ( P =.03). The PL bundle does not affect anterior translation and rotation of the knee. The AM bundle is the primary restraint of the anterior translation but does not affect rotation of the knee. The lateral compartment becomes the primary restraint of rotation after ACL cut. The primary kinematic effect of an ACL injury is an increase in anterior tibial translation, but there is no significant change in maximum internal or external rotation. The lesion of the ALFTL increases tibial rotation and could be correlated to the pivot shift phenomenon.

The automation of ab initio simulations is essential in view of performing high-throughput (HT) computational screenings oriented to the discovery of novel materials with desired physical properties. In this work, we propose algorithms and implementations that are relevant to extend this approach beyond density functional theory (DFT), in order to automate many-body perturbation theory (MBPT) calculations. Notably, a novel algorithm pursuing the goal of an efficient and robust convergence procedure for GW and BSE simulations is provided, together with its implementation in a fully automated framework. This is accompanied by an automatic GW band interpolation scheme based on maximally-localized Wannier functions, aiming at a reduction of the computational burden of quasiparticle band structures while preserving high accuracy. The proposed developments are validated on a set of representative semiconductor and metallic systems., Comment: 14 pages, 6 figures

Using accurate first-principles calculations based on many-body perturbation theory we predict that two-dimensional MoS$_2$ hosts edge excitons with universal character, intrinsic to the existence of edges and lying well below the onset of bulk features. These excitons are largely insensitive to edge terminations or orientation, persisting even in the presence of metallic screening at zigzag edges, with large binding energies of $\sim$0.4 eV. Additional excitons can also emerge in ultranarrow ribbons, or as a function of the chemical nature of the termination. The chemical, structural, and electronic similarities with Se- or W-based transition-metal dichalcogenides suggest that these optical features could be common in this class of materials., Comment: 7 pages main text, 5 pages supplemental material, 12 figures

We investigate from first principles the electronic and transport properties of hybrid organic/silicon interfaces of relevance to molecular electronics. We focus on conjugated molecules bonded to hydrogenated Si through hydroxyl or thiol groups. The electronic structure of the systems is addressed within density functional theory, and the electron transport across the interface is directly evaluated within the Landauer approach. The microscopic effects of molecule-substrate bonding on the transport efficiency are explicitly analyzed, and the oxygen-bonded interface is identified as a candidate system when preferential hole transfer is needed.

We investigate two phases of polythiophene crystals by means of first-principles calculations, focusing on the effect of the different structure on charge transport parameters and luminescence quantum yield. The resulting microscopic interpretation highlights the impact of solid-state interchain coupling on both transport and emissive properties of semiconducting polymer crystals.

Dynamical potentials appear in many advanced electronic-structure methods, including self-energies from many-body perturbation theory, dynamical mean-field theory, electronic-transport formulations, and many embedding approaches. Here, we propose a novel treatment for the frequency dependence, introducing an algorithmic inversion method that can be applied to dynamical potentials expanded as sum over poles. This approach allows for an exact solution of Dyson-like equations at all frequencies via a mapping to a matrix diagonalization, and provides simultaneously frequency-dependent (spectral) and frequency-integrated (thermodynamic) properties of the Dyson-inverted propagators. The transformation to a sum over poles is performed introducing $n$-th order generalized Lorentzians as an improved basis set to represent the spectral function of a propagator, and using analytic expressions to recover the sum-over-poles form. Numerical results for the homogeneous electron gas at the $G_0W_0$ level are provided to argue for the accuracy and efficiency of such unified approach., Comment: Main: 16 pages, 11 figures. Supplemental Material: 4 pages, 10 figures

One hundred sixteen patients underwent extensor mechanism reconstruction. Ninety-four returned at fol lowup (3 to 11 years after surgery). Twenty-two pa tients were lost to followup. Subjectively, 74% of the patients had either an excellent or good result and 26% either a fair or poor result. We found retrospectively, that the patients with either fair or poor results had a stable or only mildly unstable patella preoperatively.

Background: Patellar tendinopathy (jumper's knee) is an overuse syndrome that frequently affects athletes. A retrospective study was done to analyze the results at a minimum of five years after the performance of a surgical technique in competitive athletes. Methods: From 1985 to 1995, thirty-two patients (thirty-eight knees) affected by patellar tendinopathy were treated surgically after failure of nonoperative treatment. All knees were operated on by the same surgeon using the same surgical technique: longitudinal splitting of the tendon, excision of any abnormal tissue that was identified, and resection and drilling of the inferior pole of the patella. The results in twenty-seven patients (thirty-three knees), including twenty-two athletes (twenty-seven knees) who were still involved in sports activities (or wished to still be involved) at a competitive level at the time of final follow-up, were reviewed at a mean of eight years postoperatively. The results were evaluated according to symptoms and the ability to return to full sports activities. Results: The result was excellent in twenty-three knees (70%), good in five, fair in one, and poor in four at the time of the long-term follow-up. Eighty-two percent of the patients who tried to pursue sports at their preinjury level were able to do so, and 63% of those knees were totally symptom-free. Conclusions: The outcome of the described surgical treatment appears to be satisfactory; however, the results are less predictable in volleyball players.

Pentacene adsorbed on the Cu(119) vicinal surface forms long-range ordered chain structures. Photoemission spectroscopy measurements and ab initio density functional theory simulations provide consistent evidences that pentacene molecular orbitals mix with the copper bands, giving rise to interaction states localized at the interface. Angular-resolved and polarization dependent photoemission spectroscopy shows that most of the pentacene derived intensity is strongly dichroic. The symmetry of the molecular states of the free pentacene molecules is reduced upon adsorption on Cu(119), as a consequence of the molecule-metal interaction. Theoretical results show a redistribution of the charge density in $\ensuremath{\pi}$ molecular states close to the Fermi level, consistent with the photoemission intensities (density of states) and polarization dependence (orbital symmetry).

Background In recent years, the type of surgical treatment for Achilles tendon rupture has been the subject of controversial debate. This biomechanical study evaluates for the first time in literature the ultimate failure load (UFL) of interlocking horizontal mattress (IHM) suture as compared with Kakiuchi suture in Achilles tendon rupture. The hypothesis is that IHM suture can be performed also for Achilles tendon rupture and ensures higher resistance compared with the traditional Kakiuchi suture. Materials and methods Twenty fresh bovine Achilles tendons were obtained. Ten preparations were randomly assigned to each of two different groups: group A (10 specimens) sutured by IHM technique, and group B (10 specimens) sutured by Kakiuchi technique. Each construct was mounted and fixed on a tensile testing machine. Static preconditioning of 50 N was applied for 5 min as initial tensioning to stabilize the mechanical properties of the graft, then a load to failure test was performed at crosshead speed of 500 mm/min. Results Ten specimens were tested for each group. The mean UFL was 228.6 ± 98.6 N in the IHM suture group and 96.57 ± 80.1 N in the Kakiuchi suture group. Statistical analysis showed a significant difference (p

Defects in one-dimensional (1D) systems can be intrinsically distinct from its three-dimensional counterparts, and polymer films are good candidates for showing both extremes that are difficult to individuate in the experimental data. We study theoretically the impact of simple hydrogen and oxygen defects on the electron transport properties of one-dimensional poly(para-phenylenevinylene) chains through a multiscale technique, starting from classical structural simulations for crystalline films to extensive ab initio calculations within density functional theory for the defects in single crystalline-constrained chains. The most disruptive effect on carrier transport comes from conjugation breaking imposed by the overcoordination of a carbon atom in the vinyl group independently from the chemical nature of the defect. The particular case of the $[\text{C}=\text{O}]$ (keto-defect) shows in addition unexpected electron-hole separation, suggesting that the experimentally detected photoluminescence bleaching and photoconductivity enhancement could be due to exciton dissociation caused by the 1D characteristics of the defect.

We report on the electronic properties of an artificial system obtained by the intercalation of equiatomic FeCo layers under graphene grown on Ir(111). Upon intercalation, the FeCo film grows epitaxially on Ir(111), resulting in a lattice-mismatched system. By performing Density Functional Theory calculations, we show that the intercalated FeCo layer leads to a pronounced corrugation of the graphene film. At the same time, the FeCo intercalated layers induce a clear transition from a nearly undisturbed to a strongly hybridized graphene {\pi}-band, as measured by angle-resolved photoemission spectroscopy. A comparison of experimental results with the computed band structure and the projected density of states unveils a spin-selective hybridization between the {\pi} band of graphene and FeCo-3d states. Our results demonstrate that the reduced dimensionality, as well as the hybridization within the FeCo layers, induce a narrowing and a clear splitting of Fe 3d-up and Fe 3d-down spin bands of the confined FeCo layers with respect to bulk Fe and Co., Comment: 5 pages, 4 figures

Quantum ESPRESSO is an open-source distribution of computer codes for quantum-mechanical materials modeling, based on density-functional theory, pseudopotentials, and plane waves, and renowned for its performance on a wide range of hardware architectures, from laptops to massively parallel computers, as well as for the breadth of its applications. In this paper, we present a motivation and brief review of the ongoing effort to port Quantum ESPRESSO onto heterogeneous architectures based on hardware accelerators, which will overcome the energy constraints that are currently hindering the way toward exascale computing.

While the demonstrated power conversion eff i ciency of organic photovoltaics (OPVs) now exceeds 10%, new design rules are required to tailor interfaces at the molecular level for optimal exciton dissociation and charge transport in higher effi ciency devices. We show that molecular shape-complementarity between donors and acceptors can drive performance in OPV devices. Using core hole clock (CHC) X-ray spectroscopy and density functional theory (DFT), we compare the electronic coupling, assembly, and charge transfer rates at the interface between C 60 acceptors and fl at- or contorted-hexabenzocorone (HBC) donors. The HBC donors have similar optoelectronic properties but differ in molecular contortion and shape matching to the fullerene acceptors. We show that shape-complementarity drives self-assembly of an intermixed morphology with a donor/acceptor (D/A) ball-and-socket interface, which enables faster electron transfer from HBC to C 60 . The supramolecular assembly and faster electron transfer rates in the shape complementary heterojunction lead to a larger active volume and enhanced exciton dissociation rate. This work provides fundamental mechanistic insights on the improved effi ciency of organic photovoltaic devices that incorporate these concave/convex D/A materials.