Centrality evolution of the charged-particle pseudorapidity density over a broad pseudorapidity range in Pb-Pb collisions at root s(NN)=2.76TeV

Peer reviewe

Proximal adductor longus tendon repair with a concomitant distal fascial release for complete hip adductor tendon tears:surgical technique and outcomes in 40 male athletes

Abstract Background: The optimal treatment for complete avulsions of the proximal adductor longus (AL) is still debatable, and different operative and nonoperative treatment options have been suggested. Purpose: To report surgical techniques and functional outcomes of a series of athletes who were treated operatively for proximal AL tears. Study Design: Case series; Level of evidence, 4. Methods: A retrospective evaluation of patients who underwent surgical repair of complete proximal AL tear with concomitant distal fascial release with or without lesions of the neighboring soft tissue structures was performed. This included preinjury Tegner score, age, number of tendons involved, time interval from injury to surgery, and postoperative complications. Self-reported outcomes were defined based on the ability to regain sports activities (excellent, good, moderate, fair, or poor). Between-group comparisons were performed to identify factors associated with improved outcomes. The Mann-Whitney nonparametric test was used for comparing continuous variables, and the Fisher exact test was used for comparing nominal variables. Results: A total of 40 male athletes were included in the evaluation, with an average follow-up of 11 months (range, 6 months-8 years). Self-reported outcome was excellent in 23 (57.5%), good in 13 (32.5%), and moderate in 4 (10%) patients. Comparisons between patients with excellent versus good/moderate outcomes revealed nonsignificant differences regarding age at injury and preinjury Tegner score. Athletes with excellent outcomes received surgery sooner after the injury compared with athletes with good/moderate outcomes (2.4 ± 1.8 vs 11.4 ± 11.0 weeks, respectively; P < 0.01). Conclusion: Surgical repair for complete proximal AL tears with a concomitant distal fascial release resulted in outcomes rated as good or excellent in 90% of the cases. This treatment should be considered particularly in high-level athletes with a clear tendon retraction and within the first month after the injury. Further research is nevertheless needed to compare these outcomes with other treatment alternatives to better define criteria advocating surgery

Calcaneal bone bruise after surgery for insertional Achilles tendinopathy

Abstract Objectives: Excision of the posterosuperior corner of the calcaneus (EPCC) is routinely undertaken in athletes after failure of conservative management of insertional Achilles tendinopathy. Some patients can experience sharp calcaneal pain during postoperative rehabilitation, a sign of a calcaneal bone bruise (CBB). Design: Case series, level of evidence IV. Setting: University teaching hospital. Patients: This study reports 8 patients who developed postoperative CBB after having started impact training too early. Intervention: Patients in whom a diagnosis of CBB had been formulated were followed to return-to-play and resolution of bone edema by MRI. Main Outcome Measures: Detection of CBB after EPCC. Results: After routine EPCC for insertional Achilles tendinopathy, 8 patients presented with sharp pain for a mean 7.1 weeks (median 6 weeks, range 5‐11 weeks) before clinical suspicion of CBB. At that stage, MRI showed clear evidence of a bone bruise, with a diagnosis of CBB formulated at an average of 10.8 postoperative weeks (range 6‐16 weeks). Calcaneal bone bruise resolved with modified symptom-free loading. Patients returned to play at average on 5.6 months (range 2‐9 months) after the diagnosis of postoperative CBB. Conclusions: We describe 8 athletes who developed painful CBB following routine EPCC for insertional Achilles tendinopathy after having increased their level of activities too soon after the index procedure. In these patients, the diagnosis of postoperative CBB can be formulated by MRI and more cautious rehabilitation implemented

Tears of biceps femoris, semimembranosus, and semitendinosus are not equal:a new individual muscle-tendon concept in athletes

Abstract Objectives: Hamstring injuries are common and can now be accurately diagnosed. In addition, novel surgical indications have been introduced. However, evidence-based guidelines on the hamstring injuries in management of top-level athletes are missing. Methods: The management methods and outcomes of treatment are classically based on relatively small case series. We discuss a novel concept based on the fact that each tendon of the hamstrings muscle should be managed in an individual fashion. Furthermore, suitable indications for hamstring surgery in athletes are introduced. Results: The present study introduces modern treatment principles for hamstring injury management. Typical clinical and imagining findings as well as surgical treatment are presented based on a critical review of the available literature and personal experience. Conclusions: Hamstring injuries should not be considered to be all equal given the complexity of this anatomical region: The three separate tendons are different, and this impacts greatly on the decision-making process and outcomes in athletes

Measurement of electrons from semileptonic heavy-flavour hadron decays at midrapidity in pp and Pb–Pb collisions at √sNN = 5.02 TeV

The differential invariant yield as a function of transverse momentum (pT) of electrons from semileptonic heavy-flavour hadron decays was measured at midrapidity in central (0–10%), semi-central (30–50%) and peripheral (60–80%) lead–lead (Pb–Pb) collisions at √sNN = 5.02 TeV in the pT intervals 0.5–26 GeV/c (0–10% and 30–50%) and 0.5–10 GeV/c (60–80%). The production cross section in proton–proton (pp) collisions at √s = 5.02 TeV was measured as well in 0.5 < pT < 10 GeV/c and it lies close to the upper band of perturbative QCD calculation uncertainties up to pT = 5 GeV/c and close to the mean value for larger pT. The modification of the electron yield with respect to what is expected for an incoherent superposition of nucleon–nucleon collisions is evaluated by measuring the nuclear modification factor RAA. The measurement of the RAA in different centrality classes allows in-medium energy loss of charm and beauty quarks to be investigated. The RAA shows a suppression with respect to unity at intermediate pT, which increases while moving towards more central collisions. Moreover, the measured RAA is sensitive to the modification of the parton distribution functions (PDF) in nuclei, like nuclear shadowing, which causes a suppression of the heavy-quark production at low pT in heavy-ion collisions at LHC

Dielectron and heavy-quark production in inelastic and high-multiplicity proton–proton collisions at √s = 13 TeV

The measurement of dielectron production is presented as a function of invariant mass and transverse momentum (pT) at midrapidity (|ye| < 0.8) in proton–proton (pp) collisions at a centre-of-mass energy of √s = 13 TeV. The contributions from light-hadron decays are calculated from their measured cross sections in pp collisions at √s = 7 TeV or 13 TeV. The remaining continuum stems from correlated semileptonic decays of heavy-flavour hadrons. Fitting the data with templates from two different MC event generators, PYTHIA and POWHEG, the charm and beauty cross sections at midrapidity are extracted for the first time at this collision energy: dσcc¯/dy|y=0 = 974 ± 138 (stat.) ± 140 (syst.) ± 214(BR) μb and dσbb¯ /dy|y=0 = 79 ± 14 (stat.) ± 11 (syst.) ± 5(BR) μb using PYTHIA simulations and dσcc¯/dy|y=0 = 1417 ± 184 (stat.) ± 204 (syst.) ± 312(BR) μb and dσbb¯ /dy|y=0 = 48 ± 14 (stat.) ± 7 (syst.) ± 3(BR) μb for POWHEG. These values, whose uncertainties are fully correlated between the two generators, are consistent with extrapolations from lower energies. The different results obtained with POWHEG and PYTHIA imply different kinematic correlations of the heavy-quark pairs in these two generators. Furthermore, comparisons of dielectron spectra in inelastic events and in events collected with a trigger on high charged-particle multiplicities are presented in various pT intervals. The differences are consistent with the already measured scaling of light-hadron and open-charm production at high charged-particle multiplicity as a function of pT. Upper limits for the contribution of virtual direct photons are extracted at 90% confidence level and found to be in agreement with pQCD calculations

Charged-particle multiplicity distributions over a wide pseudorapidity range in proton-proton collisions at √s = 0.9, 7 and 8 TeV

We present the charged-particle multiplicity distributions over a wide pseudorapidity range (−3.4<η<5.0) for pp collisions at s√= 0.9, 7, and 8 TeV at the LHC. Results are based on information from the Silicon Pixel Detector and the Forward Multiplicity Detector of ALICE, extending the pseudorapidity coverage of the earlier publications and the high-multiplicity reach. The measurements are compared to results from the CMS experiment and to PYTHIA, PHOJET and EPOS LHC event generators, as well as IP-Glasma calculations

Measurement of Λ(1520) production in pp collisions at √s = 7 TeV and p–Pb collisions at √sNN = 5.02 TeV

The production of the Λ(1520) baryonic resonance has been measured at midrapidity in inelastic pp collisions at s√ = 7 TeV and in p-Pb collisions at sNN−−−√ = 5.02 TeV for non-single diffractive events and in multiplicity classes. The resonance is reconstructed through its hadronic decay channel Λ(1520) → pK− and the charge conjugate with the ALICE detector. The integrated yields and mean transverse momenta are calculated from the measured transverse momentum distributions in pp and p-Pb collisions. The mean transverse momenta follow mass ordering as previously observed for other hyperons in the same collision systems. A Blast-Wave function constrained by other light hadrons (π, K, K0S, p, Λ) describes the shape of the Λ(1520) transverse momentum distribution up to 3.5 GeV/c in p-Pb collisions. In the framework of this model, this observation suggests that the Λ(1520) resonance participates in the same collective radial flow as other light hadrons. The ratio of the yield of Λ(1520) to the yield of the ground state particle Λ remains constant as a function of charged-particle multiplicity, suggesting that there is no net effect of the hadronic phase in p-Pb collisions on the Λ(1520) yield