Observation of Pauli blocking in light scattering from quantum degenerate fermions.

The Pauli exclusion principle forbids indistinguishable fermions from occupying the same quantum mechanical state. The implications of this are profound; for example, it accounts for the electronic shell structure of atoms. Here, we performed measurements on the scattering of light from ultracold ensembles of atoms. For a Fermi gas in the quantum degenerate regime, we observed a marked suppression in scattering compared with a similarly prepared Bose gas. The observed decrease in fluorescence and the corresponding increase in light transmission results from Pauli blocking, where Fermi-Dirac statistics limits the number of accessible states for a scattering atom in a large Fermi sea. Our work confirms a fundamental result on the optical response of quantum gases and may contribute to cooling and thermometry schemes.

Acute colonic pseudo-obstruction after cesarean section and gastrointestinal symptoms⋆.

OBJECTIVE: To investigate whether women who developed acute colonic pseudo-obstruction (ACPO) after cesarean section have a higher degree of gastro-intestinal symptoms than women who did not develop ACPO after cesarean section. ACPO is a colonic dilatation without mechanical obstruction, and with an unknown pathophysiology. In younger people it is mostly seen in women after cesarean section. The hypothesis of the present study is that long-term consequences of gastrointestinal symptoms evolve after ACPO, due to the impact on the colon. STUDY DESIGN: 40 women who developed ACPO after cesarean section (cases) and 80 women, who did not develop ACPO after cesarean section (controls), were asked to participate in the study. The controls were matched based on time of cesarean section (± 14 days), age (±5 years), singleton or twin, parity, cesarean section grade, and ASA-group. Baseline characteristics and information regarding the cesarean section were collected from medical records. An electronic collection of surveys was distributed to the participants, including the following: Irritable Bowel Syndrome - Severity Scoring System (IBS-SSS), Rome IV, Gastrointestinal Symptoms Rating Scale (GSRS), Visceral Sensitivity Index (VSI), Patient Health Questionnaire 15 (PHQ15), The MOS 36-item Short-Form Health Survey (SF-36), and Hospital Anxiety and Depression Scale (HADS). The score from IBS-SSS after cesarean section was used as the primary outcome. RESULTS: 25 cases and 37 controls participated in the study. A difference in blood loss was found with a median of 600 mL in cases, compared to 400 mL in controls during cesarean section (p = 0.002). No difference was found between cases and controls in the IBS-SSS score after cesarean section. However, cases yielded a higher difference between IBS-SSS before and after cesarean section, indicating a higher degree of deterioration in gastrointestinal symptoms (p = 0.026). In addition, cases reported a higher degree of pain in everyday life (p = 0.039). No difference was found in the remaining surveys. CONCLUSION: Women undergoing cesarean section developed mild grade of irritable bowel syndrome. However, gastrointestinal symptoms did not seem to be more prevalent in women who developed ACPO, although women with ACPO had a higher degree of deterioration in gastrointestinal symptoms than controls.

First-line treatment of pelvic organ prolapse and discontinuation of pessary treatment.

INTRODUCTION: The primary objective of this study was to investigate the percentages of women choosing watchful waiting, pessary use or surgery as first-line treatment of pelvic organ prolapse (POP). Second, the rate and cause of discontinuation of pessary use were investigated. METHODS: A retrospective chart review was conducted on 794 patients referred with POP at a Danish tertiary center for urogynecology at Aalborg University Hospital between 1 January 2014 and 31 December 2015. The following data were registered: age, BMI, previous use of a pessary, total number of births, vaginal births, cesarean sections, previous hysterectomy, prolapse surgery and incontinence surgery, smoking, menopause, sexual status and POP-Q stage in the three vaginal compartments. Pessary treatments were evaluated after 3 months. Additional visits, reason for discontinuation and secondary treatment were noted. RESULTS: First-line treatment was surgery in 50%, watchful waiting in 33% and pessary use in 17% of patients. Characteristics associated with choosing surgery instead of a pessary were age < 65 years, previous prolapse surgery, prolapse in the anterior or posterior compartment, and POP-Q stage > 2. Characteristics associated with choosing watchful waiting instead of a pessary were age < 65 years and prolapse in the posterior compartment. A total of 33% discontinued pessary treatment within the first 3 months. Discontinuation was associated with age < 65 years, previous hysterectomy and pelvic surgery, and additional visits. Expulsion of the pessary and pain/discomfort were the main causes of discontinuation. CONCLUSION: This study showed that 50% of patients referred with POP were treated with conservative treatment (watchful waiting and pessary) and thus more women could probably be treated in primary care.

What happens to urinary incontinence after pelvic organ prolapse surgery?

INTRODUCTION AND HYPOTHESIS: The beneficial effect of pelvic organ prolapse (POP) surgery on urge urinary incontinence (UI) is well described in the literature, while effect on preoperative stress UI (SUI) is still unclear. The aim of this study was to investigate changes concerning UUI following POP surgery without concomitant anti-incontinence procedures and to identify possible factors influencing the changes. METHODS: We conducted a retrospective study of 678 women with prolapse surgery using native tissue repair during a 3-year period. Patients completed three prolapse questions from the International Consultation on Incontinence-Vaginal Symptoms (ICIQ-VS) questionnaire and the International Consultation on Incontinence Questionnaire-Urinary Incontinence Short Form (ICIQ-UI SF) before undergoing surgery and 3 months postoperatively. Patients who scored >0 on the ICIQ-UI SF before surgery were included in the study. RESULTS: A total of 379 patients (55.9%) with POP had concomitant UI. At 3 months' follow-up, 174 patients (46%) became continent compared with 205 patients (54%) with UI. Patients with remaining UI had statistically significant higher mean preoperative ICIQ-UI SF score than patients who became dry. The risk of remaining UI after POP surgery was greater in patients with previous anti-incontinence repair. UI type was not a risk factor for its persistance. CONCLUSION: Almost half of the patients with UI before POP surgery became completely dry after prolapse surgery alone. Severity of incontinence and previous anti-incontinence surgery were identified as risk factors for persisting UI after POP surgery. We found a reduction of incontinence after an operation in any of the three compartments.

Observation of bound state self-interaction in a nano-eV atom collider.

Quantum mechanical scattering resonances for colliding particles occur when a continuum scattering state couples to a discrete bound state between them. The coupling also causes the bound state to interact with itself via the continuum and leads to a shift in the bound state energy, but, lacking knowledge of the bare bound state energy, measuring this self-energy via the resonance position has remained elusive. Here, we report on the direct observation of self-interaction by using a nano-eV atom collider to track the position of a magnetically-tunable Feshbach resonance through a parameter space spanned by energy and magnetic field. Our system of potassium and rubidium atoms displays a strongly non-monotonic resonance trajectory with an exceptionally large self-interaction energy arising from an interplay between the Feshbach bound state and a different, virtual bound state at a fixed energy near threshold.

Retrospective study on de novo postoperative urinary incontinence after pelvic organ prolapse surgery.

OBJECTIVE: Reported incidences of de novo urinary incontinence (UI) following pelvic organ prolapse (POP) surgery in preoperatively continent women vary between 2% and 43%. The aim of this study was to investigate the incidence and the types of de novo UI and differences between operations in different compartments. STUDY DESIGN: Retrospective study of 678 women with POP surgery using native tissue repair during a 3-year period. Patients completed three modified prolapse questions from the International Consultation on Incontinence-Vaginal Symptoms (ICIQ-VS) and the International Consultation on Incontinence Questionnaire- Urinary Incontinence Short Form (ICIQ-UI SF) before undergoing surgery and 3 months postoperatively. Patients who were totally dry and scored 0 on ICIQ-UI SF before surgery were included in the study (N=299). The patients developing new onset UI on ICIQ-UI SF postoperatively were interviewed by telephone after median 30 months. RESULTS: A total of 33 patients (11%) developed subjective de novo UI at 3 months follow-up. The majority of patients (N=16) reported stress UI. The risk of developing de novo UI increased with parity (p=0.03). We found no difference between operations in different compartments. At long-term follow-up 12 patients became continent without incontinence surgery or medical treatment leaving only 21 patients (7%) incontinent. CONCLUSION: The risk of developing de novo UI after prolapse surgery with native tissue repair is low and improves over time. Parity is significantly associated with the risk of developing de novo UI. There is no difference in the incidence of de novo incontinence between operations in different compartments.

Above-threshold scattering about a Feshbach resonance for ultracold atoms in an optical collider.

Ultracold atomic gases have realized numerous paradigms of condensed matter physics, where control over interactions has crucially been afforded by tunable Feshbach resonances. So far, the characterization of these Feshbach resonances has almost exclusively relied on experiments in the threshold regime near zero energy. Here, we use a laser-based collider to probe a narrow magnetic Feshbach resonance of rubidium above threshold. By measuring the overall atomic loss from colliding clouds as a function of magnetic field, we track the energy-dependent resonance position. At higher energy, our collider scheme broadens the loss feature, making the identification of the narrow resonance challenging. However, we observe that the collisions give rise to shifts in the center-of-mass positions of outgoing clouds. The shifts cross zero at the resonance and this allows us to accurately determine its location well above threshold. Our inferred resonance positions are in excellent agreement with theory.Studies on energy-dependent scattering of ultracold atoms were previously carried out near zero collision energies. Here, the authors observe a magnetic Feshbach resonance in ultracold Rb collisions for above-threshold energies and their method can also be used to detect higher partial wave resonances.

Dispersive optical detection of magnetic Feshbach resonances in ultracold gases.

Magnetically tunable Feshbach resonances in ultracold atomic systems are chiefly identified and characterized through time-consuming atom loss spectroscopy. We describe an off-resonant dispersive optical probing technique to rapidly locate Feshbach resonances and demonstrate the method by locating four resonances of 87Rb, between the |F = 1,mF = 1〉 and |F = 2,mF = 0〉 states. Despite the loss features being ≲0.1 G wide, we require only 21 experimental runs to explore a magnetic field range >18 G, where 1G = 10-4 T. The resonances consist of two known s-wave features in the vicinity of 9 G and 18 G and two previously unreported p-wave features near 5G and 10 G. We further utilize the dispersive approach to directly characterize the two-body loss dynamics for each Feshbach resonance.

Note: computer controlled rotation mount for large diameter optics.

We describe the construction of a motorized optical rotation mount with a 40 mm clear aperture. The device is used to remotely control the power of large diameter laser beams for a magneto-optical trap. A piezo-electric ultrasonic motor on a printed circuit board provides rotation with a precision better than 0.03° and allows for a very compact design. The rotation unit is controlled from a computer via serial communication, making integration into most software control platforms straightforward.

[Intrauterine pregnancy following balloon thermal endometrial ablation (Cavaterm)]. / Intrauterin graviditet efter Cavatermbehandling.

A case of intrauterine pregnancy occurring after successful balloon thermal endometrial ablation is described. Although rare, pregnancy after endometrial ablation is possible, and use of a supplemental contraceptive method should be planned. In case of pregnancy after endometrial ablation, the woman should be informed of the high risk of pregnancy complications, and termination of the pregnancy should be discussed.

Imaging of s and d partial-wave interference in quantum scattering of identical bosonic atoms.

We report on the direct imaging of s and d partial-wave interference in cold collisions of atoms. Two ultracold clouds of 87Rb atoms were accelerated by magnetic fields to collide at energies near a d-wave shape resonance. The resulting halos of scattered particles were imaged using laser absorption. By scanning across the resonance we observed a marked evolution of the scattering patterns due to the energy dependent phase shifts for the interfering s and d waves. Since only two partial-wave states are involved in the collision process the scattering yield and angular distributions have a simple interpretation in terms of a theoretical model.

Observation of a structural transition for Coulomb crystals in a linear Paul trap.

A structural transition for laser cooled ion Coulomb crystals in a linear Paul trap just above the stability limit of parametrically resonant excitation of bulk plasma modes has been observed. In contrast to the usual spheroidal shell structures present below the stability limit, the ions arrange in a "string-of-disks" configuration. The spheroidal envelopes of the string-of-disks structures are in agreement with results from cold fluid theory usually valid for ion Coulomb crystals if the ion systems are assumed to be rotating collectively.

Stability of Coulomb crystals in a linear Paul trap with storage-ring-like confinement.

We report experiments on the stability of ion Coulomb crystals in a linear Paul trap with storage-ring-like confinement. The transverse dynamics of charged particles in a trap of this type is analogous to that of a fast beam traveling through a channel with periodic, magnetic alternating gradient confinement. The experimentally observed stability conditions for stationary crystals comply remarkably well with current theory of crystalline plasmas and beams.