We study a two-dimensional fermionic cloud of repulsive alkali-metal atoms characterized by two hyperfine states which are Rabi coupled. Within a variational Hartree-Fock scheme, we calculate ...analytically the ground-state energy of the system. Then we determine the conditions under which there is a quantum phase transition with spontaneous symmetry breaking from a spin-balanced configuration to a spin-polarized one, an effect known as itinerant ferromagnetism. Interestingly, we find that the transition appears when the interaction energy per particle exceedes both the kinetic energy per particle and the Rabi coupling energy. The itinerant ferromagnetism of the polarized phase is analyzed, obtaining the population imbalance as a function of interaction strength, Rabi coupling, and number density. Finally, the inclusion of a external harmonic confinement is investigated by adopting the local density approximation. We predict that a single atomic cloud can display population imbalance near the center of the trap and a fully balanced configuration at the periphery.
Quantum dynamics of impurities in a bath of bosons is a long-standing problem in solid-state, plasma, and atomic physics. Recent experimental and theoretical investigations with ultracold atoms have ...focused on this problem, studying atomic impurities immersed in an atomic Bose-Einstein condensate (BEC) and for various relative coupling strengths tuned by the Fano−Feshbach resonance technique. Here, we report extensive numerical simulations on a closely related problem: the collision between a bosonic impurity consisting of a few 41K atoms and a BEC of 87Rb atoms in a quasi one-dimensional configuration and under a weak harmonic axial confinement. For small values of the inter-species interaction strength (regardless of its sign), we find that the impurity, which starts from outside the BEC, simply causes the BEC cloud to oscillate back and forth, but the frequency of oscillation depends on the interaction strength. For intermediate couplings, after a few cycles of oscillation the impurity is captured by the BEC, and strongly changes its amplitude of oscillation. In the strong interaction regime, if the inter-species interaction is attractive, a local maximum (bright soliton) in the BEC density occurs where the impurity is trapped; if, instead, the inter-species interaction is repulsive, the impurity is not able to enter the BEC cloud and the reflection coefficient is close to one. However, if the initial displacement of the impurity is increased, the impurity is able to penetrate the cloud, leading to the appearance of a moving hole (dark soliton) in the BEC.
To cite this article: Zanichelli A, Vacchini R, Badini M, Penna V, Cicardi M. Standard care impact on angioedema because of hereditary C1 inhibitor deficiency: a 21-month prospective study in a ...cohort of 103 patients. Allergy 2011; 66: 192-196. ABSTRACT: Background: Hereditary angioedema (HAE) due to the deficiency of C1 inhibitor (C1-INH) causes chronically recurrent cutaneous, abdominal and laryngeal angioedema that are disabling and potentially life-threatening. Objective: We designed a prospective study to quantify the residual disease in patients with HAE treated according to the existing consensus documents. Methods: Data were collected from diaries recording occurrence, duration, location and treatment of acute angioedema attacks. A total of 386 semesters properly completed were analyzed. Forty-seven of 103 patients were on prophylactic treatment, 41 with attenuated androgens and six with tranexamic acid. A total of 1532 angioedema attacks (one every 45.3 days) were registered. Results: Peripheral attacks were the most frequent (698), followed by abdominal (503) and combined locations (232), laryngeal edema was less common (99). Patients on prophylaxis with attenuated androgens had 7.7 attacks/year lasting 1.47 days, those on tranexamic acid had 8.1 attacks/year lasting 1.59 days, and those without prophylaxis had 8.9 attacks/year lasting 1.68. Plasma-derived C1-INH was used by 44 patients to treat a total of 376 acute attacks that resolved faster (1.1 day) than those not treated (1.85 day) or treated with tranexamic acid (1.79 day). No adverse events related to C1-INH infusion were reported. Conclusion: Our data demonstrate that tranexamic acid is not effective in the treatment of acute attacks and indicate that under the current therapeutic approach, the HAE related disability is effectively but partially reduced. Incomplete success does not appear to depend on limited efficacy of the drugs but on their limited use that can be overcome by implementing specific treatment strategies.
Motivated by recent experiments and theoretical investigations on binary mixtures, we investigate the miscible-immiscible transition at finite temperature by means of Quantum Monte Carlo. Based on ...the observation that the segregated phase is strongly affected by temperature, we propose to use the degree of demixing for thermometry of a binary bosonic mixture trapped in an optical lattice. We show that the proposed method is especially sensitive at low temperatures, of the order of the tunnelling amplitude, and therefore is particularly suitable in the regime where quantum magnetism is expected.
Abnormal development of ventral midbrain (VM) dopaminergic (DA) pathways, essential for motor and cognitive function, may underpin a number of neurological disorders and thereby highlight the ...importance of understanding the birth and connectivity of the associated neurons. While a number of regulators of VM DA neurogenesis are known, processes involved in later developmental events, including terminal differentiation and axon morphogenesis, are less well understood. Recent transcriptional analysis studies of the developing VM identified genes expressed during these stages, including the cell adhesion molecule with homology to L1 (Chl1). Here, we map the temporal and spatial expression of CHL1 and assess functional roles of substrate-bound and soluble-forms of the protein during VM DA development. Results showed early CHL1 in the VM, corresponding with roles in DA progenitor migration and differentiation. Subsequently, we demonstrated roles for CHL1 in both axonal extension and repulsion, selectively of DA neurons, suggestive of a role in guidance towards forebrain targets and away from hindbrain nuclei. In part, CHL1 mediates these roles through homophilic CHL1-CHL1 interactions. Collectively, these findings enhance our knowledge of VM DA pathways development, and may provide new insights into understanding DA developmental conditions such as autism spectrum disorders.
Background
“
Gynecomastia” is an enlargement of the male breast. Our study aims to assess patient satisfaction as well as evaluate differences in recurrence rates in lipomatous and glandular ...gynecomastia 10–19 years postoperatively.
Methods
Forty-one gynecomastia patients undergoing surgical treatment from 1997 to 2005 were invited for a follow-up examination 10–19 years postoperatively. Of these, 16 patients presented for a clinical examination. Patient satisfaction was measured with a validated questionnaire consultation satisfaction questionnaire (CSQ)-9. Furthermore, photo-material and patient charts were evaluated concerning preoperative macroscopical type of gynecomastia, BMI, and operative technique.
Results
Mean follow-up time was 13.8 years (range: 10.5–19 years). Eight patients (50%) had presented with lipomatous and eight patients (50%) with glandular gynecomastia prior to surgery. One of the patients with glandular gynecomastia (12.5%) presented with recurrence at the time of follow-up, while five of the eight patients showing lipomatous gynecomastia (62.5%) presented with recurrence. Interestingly, younger patient groups tend to be more satisfied with the operative treatment of gynecomastia than older patient groups, especially regarding the improvement of self-esteem.
Conclusions
Long-term follow-up results showed that recurrence rates are significantly higher in patients with lipomatous gynecomastia than in patients with glandular gynecomastia, with BMI increase in patients with glandular and lipomatous gynecomastia showing no statistically significant differences. Furthermore, general patient satisfaction and improvement of self-esteem was higher in younger patient groups than older patient groups.
Level of Evidence IV
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Clinical Trial Registration Number: DRKS00009630.
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