Nipple Pathology in Total Skin-Sparing Mastectomy: Implications for Immediate Reconstruction.

PURPOSE: The management of occult tumor involvement of the nipple during total skin-sparing mastectomy (TSSM) and immediate reconstruction is not well addressed in the literature. We reviewed our experience with positive nipple core biopsies, comparing outcomes of different management options. METHODS: Mastectomy and implant/expander reconstructions over a 5-year period were reviewed. Patient characteristics, type of mastectomy, and complications were analyzed. Patients were grouped by type of mastectomy/immediate reconstruction and delayed reconstruction to compare outcomes. Positive intraoperative core nipple biopsy cases formed a subset of the TSSM group. RESULTS: Forty-four of 240 (18%) cases were TSSMs performed through inferolateral incisions. All were reconstructed immediately, 24 with tissue expanders and 20 with implants. Major complications (necrosis, infection, seroma) were significantly lower than for skin-sparing mastectomies, but higher than delayed reconstruction. One case of full thickness nipple necrosis occurred. Seven of the TSSM group had positive core nipple biopsies (16%). Three of these patients underwent nipple excision and tissue expander placement at the initial surgery, of which 2 developed subsequent mastectomy skin flap necrosis requiring explantation. A third patient underwent staged nipple excision without complication. The remaining 3 patients underwent delayed nipple resection at the time of tissue expander replacement without complication. Pathology in the nipple core was invasive ductal carcinoma and ductal carcinoma in situ. No TSSM patients have developed local recurrence at follow-up. CONCLUSIONS: Concurrent excision of the nipple and an inferolateral incision increase the incidence of skin flap necrosis. Delaying nipple excision may prove to be a safer option.

Half-quantum vortex molecules in a binary dipolar Bose gas.

We study the ground state phases of a rotating two-component, or binary, Bose-Einstein condensate, wherein one component possesses a large permanent magnetic dipole moment. A variety of nontrivial phases emerge in this system, including a half-quantum vortex (HQV) chain phase and a HQV molecule phase, where HQVs bind at short distances. We attribute these phases to the development of a minimum in the HQV interaction potential, which emerges without coherent coupling or attractive interactions between the components. Thus, we show that the presence of dipolar interactions in this system provides a unique mechanism for the formation of HQV molecules and results in a rich ground state phase diagram.

Spin waves and dielectric softening of polar molecule condensates.

We consider an oblate Bose-Einstein condensate of heteronuclear polar molecules in a weak applied electric field. This system supports a rich quasiparticle spectrum that plays a critical role in determining its bulk dielectric properties. In particular, in sufficiently weak fields the system undergoes a polarization wave rotonization, leading to the development of textured electronic structure and a dielectric instability that is characteristic of the onset of a negative static dielectric function.

Meron ground state of Rashba spin-orbit-coupled dipolar bosons.

We study the effects of dipolar interactions on a Bose-Einstein condensate with synthetically generated Rashba spin-orbit coupling. The dipolar interaction we consider includes terms that couple spin and orbital angular momentum in a way perfectly congruent with the single-particle Rashba coupling. We show that this internal spin-orbit coupling plays a crucial role in the rich ground-state phase diagram of the trapped condensate. In particular, we predict the emergence of a thermodynamically stable ground state with a meron spin configuration.

Anisotropic superfluidity in a dipolar Bose gas.

We study the superfluid character of a dipolar Bose-Einstein condensate (DBEC) in a quasi-two dimensional geometry. We consider the dipole polarization to have some nonzero projection into the plane of the condensate so that the effective interaction is anisotropic in this plane, yielding an anisotropic dispersion relation. By performing direct numerical simulations of a probe moving through the DBEC, we observe the sudden onset of drag or creation of vortex-antivortex pairs at critical velocities that depend strongly on the direction of the probe's motion. This anisotropy emerges because of the anisotropic manifestation of a rotonlike mode in the system.

Critical superfluid velocity in a trapped dipolar gas.

We investigate the superfluid properties of a dipolar Bose-Einstein condensate (BEC) in a fully three-dimensional trap. Specifically, we estimate a superfluid critical velocity for this system by applying the Landau criterion to its discrete quasiparticle spectrum. We test this critical velocity by direct numerical simulation of condensate depletion as a blue-detuned laser moves through the condensate. In both cases, the presence of the roton in the spectrum serves to lower the critical velocity beyond a critical particle number. Since the shape of the dispersion, and hence the roton minimum, is tunable as a function of particle number, we thereby propose an experiment that can simultaneously measure the Landau critical velocity of a dipolar BEC and demonstrate the presence of the roton in this system.

Ischemic Hand Complications From Intra-Arterial Injection of Sublingual Buprenorphine/Naloxone Among Patients With Opioid Dependency.

BACKGROUND: Sublingual buprenorphine/naloxone, a common treatment for opioid dependence, is frequently abused by intravenous injection. Inadvertent intra-arterial injection of buprenorphine/naloxone can produce acute ischemic insult to the hand due to gelatin embolism. Our purpose was to review a series of these patients in order to describe the clinical entity, review the outcomes, and propose a rational treatment algorithm. METHODS: Clinical records of all patients evaluated by the hand surgery team between 2011 and 2015 for ischemia of the hand after buprenorphine/naloxone injection were reviewed. Treatment, complications, and amount of tissue loss were recorded. Patients presenting within 48 hours of the injection were treated with intravenous heparin for 5 days, followed by oral aspirin and clopidogrel for 30 days. Those presenting after 48 hours were treated with aspirin and clopidogrel only. RESULTS: Ten patients presented during the review period. Average follow-up time was 13 weeks. Eight had ischemia of the radial side of the hand, 1 of the ulnar side, and 1 had bilateral ischemia. Three patients were treated with intravenous heparin and 5 with oral agents. Two presented with dry gangrene and did not receive anticoagulation. All patients experienced tissue loss. There was no difference in outcome regardless of treatment. CONCLUSIONS: With the increasing use of sublingual buprenorphine/naloxone in opioid dependency, ischemic hand injuries will be seen with greater frequency. Whereas outcomes did not vary with treatment modality in this series, further study is needed to determine the most effective treatment of these injuries.

Collective phases of strongly interacting cavity photons.

We study a coupled array of coherently driven photonic cavities, which maps onto a driven-dissipative XY spin- 1 2 model with ferromagnetic couplings in the limit of strong optical nonlinearities. Using a site-decoupled mean-field approximation, we identify steady-state phases with canted antiferromagnetic order, in addition to limit cycle phases, where oscillatory dynamics persist indefinitely. We also identify collective bistable phases, where the system supports two steady states among spatially uniform, antiferromagnetic, and limit cycle phases. We compare these mean-field results to exact quantum trajectory simulations for finite one-dimensional arrays. The exact results exhibit short-range antiferromagnetic order for parameters that have significant overlap with the mean-field phase diagram. In the mean-field bistable regime, the exact quantum dynamics exhibits real-time collective switching between macroscopically distinguishable states. We present a clear physical picture for this dynamics and establish a simple relationship between the switching times and properties of the quantum Liouvillian.

Biomechanical analysis of the FlatWire Figure 8 sternal fixation device.

OBJECTIVE: To determine whether the FlatWire Figure 8 sternal fixation device (Penn United, USA) is mechanically superior to the current standard in sternotomy closure. DESCRIPTION: Unstable sternal closure using traditional steel-wire cerclage can increase postoperative pain, bony cut-through and wound dehiscence. The authors present the Figure 8 sternal fixation device to minimize these complications. Biomechanical properties of the device were compared with conventional steel wire sternal repair. EVALUATION: Using two constructs of both FlatWire and steel wire, pull-to-failure, Hertzian contact and cut-through were compared. Samples were tested to 500,000 cycles or failure. Cyclic comparisons were performed using log-rank t tests and Student's t tests for cut-through analysis. FlatWires were found to have superior biomechanical properties in all categories tested. CONCLUSION: The FlatWire provides superior biomechanical properties compared with conventional steel wire, which may lead to reduced sternal wound complications.

OBJECTIF: Déterminer si le dispositif de fixation du sternum FlatWire Figure 8 (Penn United, États-Unis) est mécaniquement supérieur à la norme actuelle pour la fermeture des sternotomies. DESCRIPTION: La fermeture du sternum au moyen du cerclage classique en fil d'acier peut accroître la douleur postopératoire, l'insertion osseuse et la déhiscence de la plaie. Les auteurs présentent le dispositif de fixation du sternum Figure 8 pour réduire ces complications au minimum. Les auteurs ont comparé les propriétés biomécaniques du dispositif à la réparation sternale classique à l'aide d'un fil d'acier. ÉVALUATION: Les auteurs ont comparé le test de tension, le contact hertzien et l'insertion du modèle FlatWire à celui du fil d'acier. Ils ont comparé les échantillons jusqu'à 500 000 cycles ou jusqu'à l'échec. Les comparaisons cycliques ont été effectuées au moyen de tests t de Mantel-Haenzel et de tests t pour l'analyse de tension. Le modèle FlatWire avait des propriétés biomécaniques supérieures dans toutes les catégories mises à l'essai. CONCLUSION: Le FlatWire a des propriétés biomécaniques supérieures à celles du fil d'acier classique, lesquelles peuvent réduire les complications de la plaie du sternum.

Manifestations of the roton mode in dipolar Bose-Einstein condensates.

We investigate the structure of trapped Bose-Einstein condensates (BECs) with long-range anisotropic dipolar interactions. We find that a small perturbation in the trapping potential can lead to dramatic changes in the condensate's density profile for sufficiently large dipolar interaction strengths and trap aspect ratios. By employing perturbation theory, we relate these oscillations to a previously identified "rotonlike" mode in dipolar BECs. The same physics is responsible for radial density oscillations in vortex states of dipolar BECs that have been predicted previously.