Very high precision bound state spectroscopy near a 85^{85}Rb Feshbach resonance

We precisely measured the binding energy of a molecular state near the Feshbach resonance in a $^{85}$Rb Bose-Einstein condensate (BEC). Rapid magnetic field pulses induced coherent atom-molecule oscillations in the BEC. We measured the oscillation frequency as a function of B-field and fit the data to a coupled-channels model. Our analysis constrained the Feshbach resonance position [155.041(18) G], width [10.71(2) G], and background scattering length [-443(3) a$_0$] and yielded new values for $v_{DS}$, $v_{DT}$, and $C_6$. These results improved our estimate for the stability condition of an attractive BEC. We also found evidence for a mean-field shift to the binding energy.Comment: 5 pages, 2 figures, submitted to PR

Resonance Superfluidity: Renormalization of Resonance Scattering Theory

We derive a theory of superfluidity for a dilute Fermi gas that is valid when scattering resonances are present. The treatment of a resonance in many-body atomic physics requires a novel mean-field approach starting from an unconventional microscopic Hamiltonian. The mean-field equations incorporate the microscopic scattering physics, and the solutions to these equations reproduce the energy-dependent scattering properties. This theory describes the high-$T_c$ behavior of the system, and predicts a value of $T_c$ which is a significant fraction of the Fermi temperature. It is shown that this novel mean-field approach does not break down for typical experimental circumstances, even at detunings close to resonance. As an example of the application of our theory we investigate the feasibility for achieving superfluidity in an ultracold gas of fermionic $^6$Li.Comment: 15 pages, 10 figure

COVID-19 and immunosuppression: a review of current clinical experiences and implications for ophthalmology patients taking immunosuppressive drugs

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged in December 2019 in Wuhan city, Hubei province, China. This is the third and largest coronavirus outbreak since the new millennium after SARS in 2002 and Middle East respiratory syndrome (MERS) in 2012. Over 3 million people have been infected and the COVID-19 has caused more than 217 000 deaths. A concern exists regarding the vulnerability of patients who have been treated with immunosuppressive drugs prior or during this pandemic. Would they be more susceptible to infection by the SARS-CoV-2 and how would their clinical course be altered by their immunosuppressed state? This is a question the wider medical fraternity-including ophthalmologists, rheumatologists, gastroenterologist and transplant physicians among others-must answer. The evidence from the SARS and MERS outbreak offer some degree of confidence that immunosuppression is largely safe in the current COVID-19 pandemic. Preliminary clinical experiences based on case reports, small series and observational studies show the morbidity and mortality rates in immunosuppressed patients may not differ largely from the general population. Overwhelmingly, current best practice guidelines worldwide recommended the continuation of immunosuppression treatment in patients who require them except for perhaps high-dose corticosteroid therapy and in patients with associated risk factors for severe COVID-19 disease.Ophthalmic researc

Histological, immunohistochemical and transcriptomic characterization of human tracheoesophageal fistulas

Esophageal atresia (EA) and tracheoesophageal fistula (TEF) are relatively frequently occurring foregut malformations. EA/TEF is thought to have a strong genetic component. Not much is known regarding the biological processes disturbed or which cell type is affected in patients. This hampers the detection of the responsible culprits (genetic or environmental) for the origin of these congenital anatomical malformations. Therefore, we examined gene expression patterns in the TEF and compared them to the patterns in esophageal, tracheal and lung control samples. We studied tissue organization and key proteins using immunohistochemistry. There were clear differences between TEF and control samples. Based on the number of differentially expressed genes as well as histological characteristics, TEFs were most similar to normal esophagus. The BMP-signaling pathway, actin cytoskeleton and extracellular matrix pathways are downregulated in TEF. Genes involved in smooth muscle contraction are overexpressed in TEF compared to esophagus as well as trachea. These enriched pathways indicate myofibroblast activated fibrosis. TEF represents a specific tissue type with large contributions of intestinal smooth muscle cells and neurons. All major cell types present in esophagus are present-albeit often structurally disorganized-in TEF, indicating that i

Reliability and Validity of the Adapted Dutch Version of the Early-Onset Scoliosis-24-Item Questionnaire (EOSQ-24)

STUDY DESIGN: Translation and validation of the Early Onset Scoliosis-24 Questionnaire (EOSQ-24). OBJECTIVE: To cross-culturally adapt the English version of the EOSQ-24 to the Dutch language and to assess the questionnaire's reliability and validity. SUMMARY OF BACKGROUND DATA: Early-onset scoliosis (EOS) has a profound impact on health-related quality of life. The EOSQ-24 is health-related quality of life questionnaire filled in by parents of children with EOS. The EOSQ-24 was already translated into multiple languages and its application was confirmed in clinical studies. However, the EOSQ-24 is not yet translated and validated for the Dutch population. METHODS: The adaption of the EOSQ-24 for the Dutch population was done in three steps: 1) translation to the Dutch language, 2) cross-cultural adaptation, and 3) cross-cultural validation. To ensure that the Adapted Dutch EOSQ-24 is applicable for clinical use, the measurement properties were tested in four steps: 1) floor and ceiling effects, 2) validation, 3) reliability, and 4) discriminative ability. One hundred three parents completed the Adapted Dutch EOSQ-24, the Child Health Questionnaire (CHQ-28 PF), and the Scoliosis Research Society Questionnaire (SRS-22r). A second EOSQ-24 was completed for test-retest reproducibility. RESULTS: The EOSQ-24 was successfully translated, adapted, and validated for the Dutch language. Almost all response items showed a normal distribution. The EOSQ-24 showed excellent reliability (Cronbach α of 0.950). The EOSQ-24 was successfully validated against the CHQ-28-PF and the SRS-22r. Test-retest was excellent (ICC ≥ 0.8). Finally, The EOSQ-24 was found capable to discriminate patients with different curve severities (P = 0.003), diagnosis (P = 0.006), and ambulatory status (P < 0.001). CONCLUSION: The current Dutch EOSQ-24 proved to be a valid and reliable quality of life assessment tool for patients with EOS. Currently, long follow-up studies using the EOSQ-24, including the Dutch EOSQ-24, are lacking and are needed to fully validate the EOSQ-24 for use in a clinical setting. LEVEL OF EVIDENCE: 2