Frequency of the Pectoralis Minor Compression Syndrome in Patients Treated for Thoracic Outlet Syndrome

BACKGROUND: Pectoralis minor compression syndrome (PMCS) is a compression of the neurovascular structures in the subpectoral tunnel and remains underestimated in the management of patients with thoracic outlet syndrome (TOS). Its underdiagnosis may be responsible for incomplete or failed treatment. The aim of the study was to evaluate the frequency of PMCS in our experience. METHODS: We retrospectively reviewed all patients treated for TOS in our department. We selected those in whom PMCS was diagnosed with a systematic dynamic arteriography. Surgery was performed using the Roos axillary approach when a first rib resection was associated or an elective approach when a first rib resection was not associated. RESULTS: From January 2004 to December 2014, 374 surgeries for TOS were performed in 279 patients, which included 90 men (sex ratio = 0.48) with a mean age of 40.1 ± 10 years old. Among these patients, 63 (22.5%) underwent 82 interventions (21.9%) for PMCS, including 26 men (sex ratio = 0.70, P < 0.05) with a mean age of 37.9 ± 9.4 years old. Tenotomy of the pectoralis minor muscle was performed using axillary approach if it was associated with a first rib resection in 74 cases (90.2%) or through an elective approach in 8 cases (9.8%) if it was isolated. Four (4.9%) postoperative complications were found (1 hematoma [1.2%], 1 hemothorax [1.2%], 1 scapula alata [1.2%], and 1 subclavian vein thrombosis [1.2%]), all after an axillary approach. In 63 cases (79.7%), preoperative symptoms were resolved. In 14 cases (17.7%), symptom resolution was incomplete, and 2 patients (2.6%) had recurrent symptoms. CONCLUSIONS: Evaluation of PMCS in TOS is justified by its frequency and the simplicity and low morbidity of the surgical procedure

Breaking stress of neutron star crust

The breaking stress (the maximum of the stress-strain curve) of neutron star crust is important for neutron star physics including pulsar glitches, emission of gravitational waves from static mountains, and flares from star quakes. We perform many molecular dynamic simulations of the breaking stress at different coupling parameters (inverse temperatures) and strain rates. We describe our results with the Zhurkov model of strength. We apply this model to estimate the breaking stress for timescales ~1 s - 1 year, which are most important for applications, but much longer than can be directly simulated. At these timescales the breaking stress depends strongly on the temperature. For coupling parameter <200, matter breaks at very small stress, if it is applied for a few years. This viscoelastic creep can limit the lifetime of mountains on neutron stars. We also suggest an alternative model of timescale-independent breaking stress, which can be used to estimate an upper limit on the breaking stress.Comment: 5 pages, 2 figures. Accepted for publication in MNRAS Letter

Observation of inhibited electron-ion coupling in strongly heated graphite

Creating non-equilibrium states of matter with highly unequal electron and lattice temperatures (Tele≠Tion) allows unsurpassed insight into the dynamic coupling between electrons and ions through time-resolved energy relaxation measurements. Recent studies on low-temperature laser-heated graphite suggest a complex energy exchange when compared to other materials. To avoid problems related to surface preparation, crystal quality and poor understanding of the energy deposition and transport mechanisms, we apply a different energy deposition mechanism, via laser-accelerated protons, to isochorically and non-radiatively heat macroscopic graphite samples up to temperatures close to the melting threshold. Using time-resolved x ray diffraction, we show clear evidence of a very small electron-ion energy transfer, yielding approximately three times longer relaxation times than previously reported. This is indicative of the existence of an energy transfer bottleneck in non-equilibrium warm dense matter

Renormalized kinetic theory of classical fluids in and out of equilibrium

We present a theory for the construction of renormalized kinetic equations to describe the dynamics of classical systems of particles in or out of equilibrium. A closed, self-consistent set of evolution equations is derived for the single-particle phase-space distribution function $f$, the correlation function $C=$, the retarded and advanced density response functions $\chi^{R,A}=\delta f/\delta\phi$ to an external potential $\phi$, and the associated memory functions $\Sigma^{R,A,C}$. The basis of the theory is an effective action functional $\Omega$ of external potentials $\phi$ that contains all information about the dynamical properties of the system. In particular, its functional derivatives generate successively the single-particle phase-space density $f$ and all the correlation and density response functions, which are coupled through an infinite hierarchy of evolution equations. Traditional renormalization techniques are then used to perform the closure of the hierarchy through memory functions. The latter satisfy functional equations that can be used to devise systematic approximations. The present formulation can be equally regarded as (i) a generalization to dynamical problems of the density functional theory of fluids in equilibrium and (ii) as the classical mechanical counterpart of the theory of non-equilibrium Green's functions in quantum field theory. It unifies and encompasses previous results for classical Hamiltonian systems with any initial conditions. For equilibrium states, the theory reduces to the equilibrium memory function approach. For non-equilibrium fluids, popular closures (e.g. Landau, Boltzmann, Lenard-Balescu) are simply recovered and we discuss the correspondence with the seminal approaches of Martin-Siggia-Rose and of Rose.and we discuss the correspondence with the seminal approaches of Martin-Siggia-Rose and of Rose.Comment: 63 pages, 10 figure