From admissions to licensure: education data associations from a multi-centre undergraduate medical education collaboration.

This paper reports the findings of a Canada based multi-institutional study designed to investigate the relationships between admissions criteria, in-program assessments, and performance on licensing exams. The study's objective is to provide valuable insights for improving educational practices across different institutions. Data were gathered from six medical schools: McMaster University, the Northern Ontario School of Medicine University, Queen's University, University of Ottawa, University of Toronto, and Western University. The dataset includes graduates who undertook the Medical Council of Canada Qualifying Examination Part 1 (MCCQE1) between 2015 and 2017. The data were categorized into five distinct sections: demographic information as well as four matrices: admissions, course performance, objective structured clinical examination (OSCE), and clerkship performance. Common and unique variables were identified through an extensive consensus-building process. Hierarchical linear regression and a manual stepwise variable selection approach were used for analysis. Analyses were performed on data set encompassing graduates of all six medical schools as well as on individual data sets from each school. For the combined data set the final model estimated 32% of the variance in performance on licensing exams, highlighting variables such as Age at Admission, Sex, Biomedical Knowledge, the first post-clerkship OSCE, and a clerkship theta score. Individual school analysis explained 41-60% of the variance in MCCQE1 outcomes, with comparable variables to the analysis from of the combined data set identified as significant independent variables. Therefore, strongly emphasising the need for variety of high-quality assessment on the educational continuum. This study underscores the importance of sharing data to enable educational insights. This study also had its challenges when it came to the access and aggregation of data. As such we advocate for the establishment of a common framework for multi-institutional educational research, facilitating studies and evaluations across diverse institutions. This study demonstrates the scientific potential of collaborative data analysis in enhancing educational outcomes. It offers a deeper understanding of the factors influencing performance on licensure exams and emphasizes the need for addressing data gaps to advance multi-institutional research for educational improvements.

Cardiovascular and renal outcomes of glucagon-like peptide 1 receptor agonists among patients with and without type 2 diabetes mellitus: A meta-analysis of randomized placebo-controlled trials.

Background: Multiple cardiovascular outcomes trials (CVOTs) have shown the efficacy of GLP-1RAs in reducing major adverse cardiovascular events (MACEs) for high-risk patients. However, some CVOTs failed to demonstrate cardiovascular benefits. Objectives: We analyzed the impact of GLP-1RA on cardiovascular and renal outcomes in patients with or without T2DM, with subgroup analysis based on sex, estimated glomerular filtration rate (eGFR), body mass index (BMI), and history of cardiovascular disease (CVD). Methods: A comprehensive database search for placebo-controlled RCTs on GLP-1RA treatment was conducted until April 2024. Data extraction and quality assessment were carried out, employing a robust statistical analysis using a random effects model to determine outcomes with log odds ratios and 95 % confidence intervals (CIs). Results: A total of 13 CVOTs comprising 83,258 patients were included. GLP-1RAs significantly reduced MACE (OR 0.86, 95 % CI: 0.80 to 0.94, p < 0.01) all-cause mortality OR 0.87, 95 % CI: 0.82 to 0.93, p < 0.001, CV mortality (OR 0.87, 95 % CI: 0.81 to 0.94, p < 0.001), stroke (fatal: OR 0.74, 95 % CI: 0.56 to 0.96, p = 0.03; non-fatal: OR 0.87, 95 % CI: 0.79 to 0.96, p = 0.005), coronary revascularization (OR 0.86, 95 % CI: 0.74 to 0.99, p = 0.023), and composite kidney outcome (OR 0.76, 95 % CI: 0.67 to 0.85, p < 0.001. GLP-1RA significantly reduced MACE in both sexes. Furthermore, GLP-1RA reduced MACE regardless of CVD history, BMI, and eGFR level. Conclusion: Significant reductions in MACE, overall and CV mortality, stroke, coronary revascularization, and composite kidney outcome with GLP-1RA treatment were noted across all subgroups.

Sex differences in transcatheter aortic valve replacement outcomes among patients with bicuspid aortic stenosis.

BACKGROUND: Despite comprising almost half of all patients undergoing valvular repair, data on transcatheter aortic valve replacement (TAVR) in patients with bicuspid aortic stenosis (BAS) are limited. OBJECTIVE: We aimed to evaluate whether there are any sex differences in trends and outcomes of TAVR in this population. METHODS: We utilized the National Inpatient Sample from 2012 to 2020 to identify admissions with BAS who underwent TAVR and analyzed trends and outcomes. Our primary outcome was in-hospital mortality and secondary outcomes were in-hospital complications. We used two models to adjust for demographics (A) and interventions (B). RESULTS: Between 2012 to 2020, there were 76,540 hospitalizations for BAS patients who underwent AVR, among which 6,010 (7.9 %) underwent TAVR. There was an overall increasing trend in number of TAVR cases with a decreasing trend in mortality (2013: 8.7 %, 2020: 1.3 %). TAVR was performed more in males (61.1% vs 38.9 %). Despite the worse baseline characteristics in males, in-hospital mortality (2.4% vs. 1.5 %; OR: 1.584; 95 % CI: 0.621-4.038; p = 0.335) and secondary outcomes were similar across both sexes, even after adjusting for demographics and interventions. CONCLUSION: TAVR in BAS has grown rapidly in the last decade. Males comprised the majority and had more comorbidities, but mortality and complications were similar in both sexes. Despite the increasing number of cases, a decreasing trend in mortality was observed for both sexes ultimately approaching that of SAVR, suggesting that TAVR may be a safe alternative among eligible males and females with bicuspid AS.

Sex differences in trends and in-hospital outcomes of acute myocardial infarction in patients with familial hypercholesterolemia: insights from a large national database.

BACKGROUND: Sex differences in clinical outcomes following acute myocardial infarction (AMI) are well known. However, data on sex differences among patients with familial hypercholesterolemia (FH) are limited. We aimed to explore sex differences in outcomes of AMI among patients with FH from a national administrative dataset. RESEARCH DESIGN AND METHODS: We utilized the National Inpatient Sample to identify admissions with a primary diagnosis of AMI and a secondary diagnosis of FH. Our primary outcome of interest was in-hospital mortality; secondary outcomes were performance of percutaneous coronary intervention (PCI), coronary artery bypass grafting (CABG), respiratory complications, use of inotropes, use of mechanical circulatory support (MCS), bleeding complications, transfusion and facility discharge. We adjusted for demographics (model A), comorbidities (model B), and intervention (model C). RESULTS: Between October 2016 and December 2020, 5,714,993 admissions with a primary diagnosis of AMI were identified, of which 3,035 (0.05%) had a secondary diagnosis of FH. In-hospital mortality did not differ between men and women (Model C, adjusted OR = 0.85; 95% CI 0.28-2.60, p = 0.773). There was no sex difference in the secondary outcomes. CONCLUSION: Despite generally being older and having more comorbidities, women with FH fair equally with men with FH in terms of mortality during AMI admission.

Glucagon-like peptide-1 receptor agonists modestly reduced blood pressure among patients with and without diabetes mellitus: A meta-analysis and meta-regression.

AIM: The cardiovascular benefits provided by glucagon-like peptide-1 receptor agonists (GLP-1RAs) extend beyond weight reduction and glycaemic control. One possible mechanism may relate to blood pressure (BP) reduction. We aim to quantify the BP-lowering effects of GLP1-RAs. METHODS: A comprehensive database search for placebo-controlled randomized controlled trials on GLP-1RA treatment was conducted until December 2023. Data extraction and quality assessment were carried out, employing a robust statistical analysis using a random effects model to determine outcomes with a mean difference (MD) in mmHg and 95% confidence intervals (CIs). The primary endpoint was the mean difference in systolic BP (SBP) and diastolic BP. Subgroup analyses and meta-regressions were done to account for covariates. RESULTS: Compared with placebo, GLP-1RAs modestly reduced SBP [semaglutide: MD -3.40 (95% CI -4.22 to -2.59, p < .001); liraglutide: MD -2.61 (95% CI -3.48 to -1.74, p < .001); dulaglutide: MD -1.46 (95% CI -2.20 to -0.72, p < .001); and exenatide: MD -3.36 (95% CI -3.63 to -3.10, p < .001)]. This benefit consistently increased with longer treatment durations. Diastolic BP reduction was only significant in the exenatide group [MD -0.94 (95% CI -1.78 to -0.1), p = .03]. Among semaglutide cohorts, mean changes in glycated haemoglobin and mean changes in body mass index were directly associated with SBP reduction. CONCLUSION: Patients on GLP-1RA experienced modest SBP lowering compared with placebo. This observed effect was associated with weight/body mass index reduction and better glycaemic control, which suggests that BP-lowering is an indirect effect of GLP-1RA and unlikely to be responsible for the benefits.

Observation of millihertz-level cooperative Lamb shifts in an optical atomic clock.

Collective couplings of atomic dipoles to a shared electromagnetic environment produce a wide range of many-body phenomena. We report on the direct observation of resonant electric dipole-dipole interactions in a cubic array of atoms in the many-excitation limit. The interactions produce spatially dependent cooperative Lamb shifts when spectroscopically interrogating the millihertz-wide optical clock transition in strontium-87. We show that the ensemble-averaged shifts can be suppressed below the level of evaluated systematic uncertainties for optical atomic clocks. Additionally, we demonstrate that excitation of the atomic dipoles near a Bragg angle can enhance these effects by nearly an order of magnitude compared with nonresonant geometries. Our work demonstrates a platform for precise studies of the quantum many-body physics of spins with long-range interactions mediated by propagating photons.

End-Of-Life Care for Patients With End-Stage Heart Failure, Comparisons of International Guidelines.

Heart failure (HF) is a chronic, debilitating condition associated with significant morbidity, mortality, and socioeconomic burden. Patients with end-stage HF (ESHF) who are not a candidate for advanced therapies will continue to progress despite standard medical therapy. Thus, the focus of care shifts from prolonging life to controlling symptoms and improving quality of life through palliative care (PC). Because the condition and prognosis of HF patients evolve and can rapidly deteriorate, it is imperative to begin the discussion on end-of-life (EOL) issues early during HF management. These include the completion of an advance directive, do-not-resuscitate orders, and policies on device therapy and discontinuation as part of advance care planning (ACP). ESHF patients who do not have indications for advanced therapies or those who wish not to have a left ventricular assist device (LVAD) or heart transplant (HT) often experience high symptom burden despite adequate medical management. The proper identification and assessment of symptoms such as pain, dyspnea, nausea, depression, and anxiety are essential to the management of ESHF and may be underdiagnosed and undertreated. Psychological support and spiritual care are also crucial to improving the quality of life during EOL. Caregivers of ESHF patients must also be provided supportive care to prevent compassion fatigue and improve resilience in patient care. In this narrative review, we compare the international guidelines and provide an overview of end-of-life and palliative care for patients with ESHF.

Sex differences in permanent pacemaker implantation after transcatheter aortic valve replacement: a systematic review and meta-analysis.

BACKGROUND: There is limited evidence on the effect of sex on permanent pacemaker implantation (PPMI) after transcatheter aortic valve replacement (TAVR). The primary objective of this meta-analysis was to determine the role of sex among patients requiring PPMI post-TAVR. METHODS: A literature search was conducted using the SCOPUS, MEDLINE, and CINAHL databases for studies published until October 2022. Eligible studies included published randomized controlled trials (RCTs) and Observational Cohort Studies (OCS) articles that reported PPMI as an outcome of pacemaker status following TAVR. This study was performed per the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Guidelines. Publication bias was estimated using a Funnel plot and Egger's test. Data were pooled using a random-effects model. The primary endpoint was the sex difference in PPMI after TAVR, with odds ratios and 95% confidence intervals (CIs) extracted. RESULTS: Data was obtained from 63 studies, and a total of 79,655 patients were included. The cumulative PPMI rate was 15.5% (95% CI, 13.6%-17.7%). The pooled analysis revealed that while there were more females than males undergoing TAVR (51.6%, 95% CI 50.4%-52.8%), males have a 14.5% higher risk for post-TAVR PPMI than females (OR 1.145, 95% CI 1.047-1.253, P < 0.01). CONCLUSIONS: Males are more likely to experience PPMI after TAVR than females. Further research needs to be done to better explain these observed differences in outcomes.

Comparing Outcomes of CT-Guided Percutaneous Pericardial Drainage with Surgical Pericardial Window in Patients with Symptomatic Pericardial Effusions.

RATIONALE AND OBJECTIVES: To compare short-term outcomes of CT-guided percutaneous pericardial drainage (PPD) versus subxiphoid surgical pericardial window (PW) drainage and analyze the risk factors associated with their outcomes. MATERIALS AND METHODS: A retrospective chart review of patients who underwent either percutaneous drainage with drainage catheter placement or PW with surgical drain placement for symptomatic pericardial effusion between January 1, 2006 and August 31, 2016 was performed after institutional review board approval (decision number 16-783). The primary objective was to test for associations between the short-term (≤30 days post procedure) complication and recurrence rates in patients with symptomatic pericardial effusions. The secondary objectives were to test for associations between short-term complications with changes in vital signs. RESULTS: Of the 257 procedures included in the final analysis, 142 were in the percutaneous drainage group. Short-term complication rate was significantly greater (p < 0.001) in patients undergoing PW, 17% (19/114), as compared with PPD, 2% (3/142). The estimated odds of having complications in the PW cohort was 9 times greater than the percutaneous drainage cohort (OR = 9.3, 95% CI:  2.7-32.3). No significant difference was observed between whether or not a patient experienced a short-term recurrence and any of the explanatory variables (patient demographics, imaging, and vital signs). CONCLUSION: CT-guided PPD is a safer alternative to surgical PW as it leads to fewer complications without a significant difference in recurrence rate of pericardial effusion.

Universal Kardar-Parisi-Zhang Dynamics in Integrable Quantum Systems.

Although the Bethe ansatz solution of the spin-1/2 Heisenberg model dates back nearly a century, the anomalous nature of its high-temperature transport dynamics has only recently been uncovered. Indeed, numerical and experimental observations have demonstrated that spin transport in this paradigmatic model falls into the Kardar-Parisi-Zhang (KPZ) universality class. This has inspired the significantly stronger conjecture that KPZ dynamics, in fact, occur in all integrable spin chains with non-Abelian symmetry. Here, we provide extensive numerical evidence affirming this conjecture. Moreover, we observe that KPZ transport is even more generic, arising in both supersymmetric and periodically driven models. Motivated by recent advances in the realization of SU(N)-symmetric spin models in alkaline-earth-based optical lattice experiments, we propose and analyze a protocol to directly investigate the KPZ scaling function in such systems.

Radiation induces ESCRT pathway dependent CD44v3+ extracellular vesicle production stimulating pro-tumor fibroblast activity in breast cancer.

Despite recent advances in radiotherapeutic strategies, acquired resistance remains a major obstacle, leading to tumor recurrence for many patients. Once thought to be a strictly cancer cell intrinsic property, it is becoming increasingly clear that treatment-resistance is driven in part by complex interactions between cancer cells and non-transformed cells of the tumor microenvironment. Herein, we report that radiotherapy induces the production of extracellular vesicles by breast cancer cells capable of stimulating tumor-supporting fibroblast activity, facilitating tumor survival and promoting cancer stem-like cell expansion. This pro-tumor activity was associated with fibroblast production of the paracrine signaling factor IL-6 and was dependent on the expression of the heparan sulfate proteoglycan CD44v3 on the vesicle surface. Enzymatic removal or pharmaceutical inhibition of its heparan sulfate side chains disrupted this tumor-fibroblast crosstalk. Additionally, we show that the radiation-induced production of CD44v3+ vesicles is effectively silenced by blocking the ESCRT pathway using a soluble pharmacological inhibitor of MDA-9/Syntenin/SDCBP PDZ1 domain activity, PDZ1i. This population of vesicles was also detected in the sera of human patients undergoing radiotherapy, therefore representing a potential biomarker for radiation therapy and providing an opportunity for clinical intervention to improve treatment outcomes.

Imprime PGG Enhances Anti-Tumor Effects of Tumor-Targeting, Anti-Angiogenic, and Immune Checkpoint Inhibitor Antibodies.

Imprime PGG (Imprime) is in late-stage clinical development as a combinatorial agent with several therapeutic modalities. Here we present pre-clinical mechanistic data supportive of Imprime, a soluble yeast ß-1,3/1,6-glucan pathogen-associated molecular pattern able to prime innate immune cells in a Dectin-1dependent manner. In tumor-free mice, Imprime evoked broad innate immune responses (type I interferon signature, mobilization of myeloid cells, dendritic cell and monocyte/macrophage expression of co-stimulatory ligands like CD86, and activation of natural killer cells). Imprime-mediated activation of myeloid cells also resulted in functional priming of antigen-specific CD8 T cell response. In tumor-bearing mice, Imprime monotherapy further resulted in activation of systemic and tumor infiltrating macrophages and enhanced cytotoxic CD8 T cell trafficking. Imprime enhanced the anti-tumor activity of several combinatorial agents in mouse cancer models; anti-tyrosinase-related protein 1 antibody in B16F10 melanoma experimental lung metastasis model, anti-vascular endothelial growth factor receptor 2 antibody in H1299 and H441 lung cancer, and anti-programmed cell death protein 1 antibody in MC38 colon cancer models. Mechanistically, combining Imprime with these combinatorial therapeutic agents elicited enhanced innate immune activation, supporting immunological synergy. Finally, Imprime treatment induced similar in vitro phenotypic and functional activation of human innate immune cells. Collectively, these data demonstrate Imprime's potential to orchestrate a broad, yet coordinated, anti-cancer immune response and complement existing cancer immunotherapies.

Disentangling Pauli Blocking of Atomic Decay from Cooperative Radiation and Atomic Motion in a 2D Fermi Gas.

The observation of Pauli blocking of atomic spontaneous decay via direct measurements of the atomic population requires the use of long-lived atomic gases where quantum statistics, atom recoil, and cooperative radiative processes are all relevant. We develop a theoretical framework capable of simultaneously accounting for all these effects in the many-body quantum degenerate regime. We apply it to atoms in a single 2D pancake or arrays of pancakes featuring an effective Λ level structure (one excited and two degenerate ground states). We identify a parameter window in which a factor of 2 extension in the atomic lifetime clearly attributable to Pauli blocking should be experimentally observable in deeply degenerate gases with ∼10^{3} atoms. We experimentally observe a suppressed excited-state decay rate, fully consistent with the theory prediction of an enhanced excited-state lifetime, on the ^{1}S_{0}-^{3}P_{1} transition in ^{87}Sr atoms.

Measurement Invariance of the Questionnaire on the Internal Stigma of Internet Surfing Among Sino-Australian Undergraduates.

BACKGROUND: The stigma of internet surfing is a relatively new area of study arising from the popularity of the internet. The Questionnaire on the Internal Stigma of Internet Surfing-9 (QISIS-9) was developed for the Chinese culture, so its suitability for use in other cultural contexts is uncertain. This paper examines the measurement invariance of the QISIS-9 among Sino-Australian undergraduates to verify the cross-cultural measurement invariance of QISIS-9 and promote cross-cultural (nationality) research regarding the internal stigma of internet surfing. METHODS: The Internal Stigma of Internet Surfing-9 (QISIS-9) was used to assess 200 Chinese undergraduates (50% female, Mage = 19.78) and 204 Australian undergraduates (76% female, Mage = 21.10), respectively. RESULTS: A confirmatory factor analysis (CFA) indicated that the single-factor model of QISIS-9 is acceptable with both Chinese and Australian undergraduates. However, the factor loading of Item 9, to which a reverse score is assigned, is not ideal for both samples. Thus, the item should be deleted. According to a multigroup confirmatory factor analysis (MCFA), QISIS-8, the revised version of QISIS-9, meets the strict measurement invariance among the Chinese and Australian participants. The QISIS-8 demonstrated appropriate internal consistency in the scores for both the Chinese and Australian undergraduates. CONCLUSION: The new QISIS-8 can effectively assess the internal stigma of internet surfing among Chinese and Australian undergraduates, and it provides a frame of reference for further cross-cultural (border) comparisons.

Antioxidant Supplementation Protects Elite Athlete Muscle Integrity During Submaximal Training.

PURPOSE: To determine (1) the effect of a 40-minute steady-state run on muscle membrane integrity of elite athletes as reflected by serum creatine kinase (CK), (2) whether antioxidant supplementation (AS) with vitamins E and C has a protective effect, and (3) if a minimal blood concentration of vitamin E or C is required for any such protection. METHODS: Fifteen elite-level endurance athletes (V˙O2max=71.5±1.2 mL·kg-1 min-1) were randomly assigned to 6 weeks AS (1000 IU·d-1 natural vitamin E and 1000 mg·d-1 vitamin C) or placebo. Using a double-blind crossover design and 4-week washout period, each treatment was followed by a 40-minute steady-state run at 3 mM blood lactate. Blood samples before and 0 and 24 hours after the run were assayed for serum and red cell α-tocopherol (α-TOH), serum ascorbate, and CK. RESULTS: The AS produced a 2.5-fold, well-correlated (r = .84) increase in serum and red cell α-TOH (P < .001) that attenuated the increase in postrun CK (P = .01). There was no change in serum ascorbate with AS and no relationship with CK (P > .1). Curvilinear regression revealed some evidence that a critical level of serum α-TOH in the vicinity of 12 mg·L-1 was required to attenuate CK efflux, a level only achieved with AS. CONCLUSION: The muscle membrane integrity of elite-level athletes is compromised even during steady-state running of moderate intensity and duration. The AS provided a protective effect, with evidence that a serum α-TOH concentration of around 12 mg·L-1 is required.

Transition from Military Service: Mental Health and Well-being Among Service Members and Veterans with Service-connected Disabilities.

Transitioning from military service is stressful for veterans with service-connected disabilities seeking civilian employment. This descriptive study examined self-assessed mental health, well-being, and substance use of men and women shortly before or after transition from US military service, compared to norms from community and military samples. As part of a prospective study evaluating an innovative employment program, researchers interviewed 229 current and former service members with service-connected disabilities transitioning from U.S. military service. Compared to published norms, respondents reported significantly poorer outcomes on 5 of 6 standardized measures, indicating less life satisfaction, poorer mental health, more symptoms of depression and posttraumatic stress disorder, and greater financial distress. In the previous year, 42% were prescribed opioid medications, over twice the annual opioid prescription rate of 19% in the general US population. Systematic strategies are needed to ensure access for transitioning veterans with serious behavioral health issues to appropriate evidence-based practices.

Barriers and facilitators to using vaporised nicotine products as smoking cessation aids among people receiving treatment for substance use disorder.

INTRODUCTION: Vaporised nicotine products (VNPs) may be useful smoking cessation aids for people in alcohol and other drug (AOD) treatment, a population with high tobacco-related morbidity and mortality rates. This qualitative study aimed to examine the barriers and facilitators of using VNPs as part of a clinical trial to reduce or quit smoking among people in AOD treatment. METHODS: Thirteen people in AOD treatment who were participating in a trial of VNPs for smoking cessation (QuitENDs) completed a brief semi-structured interview examining experiences of using VNPs to reduce or quit smoking. Transcribed data was analysed using the iterative categorisation framework. RESULTS: Many participants expressed the benefit of having a smoking cessation aid that addressed nicotine cravings and the behavioural hand-to-mouth action to help them reduce or quit smoking. Although many participants reported that VNPs were easy to use, some found maintaining the device to be challenging. Some participants described Australian regulations limiting use of VNPs as reducing their desire to use the device as a cessation aid. Many participants attempting to reduce or quit tobacco and cannabis simultaneously stated that VNPs alone were insufficient to help them reduce or quit tobacco. CONCLUSIONS: VNPs hold significant promise as smoking cessation aids among people in AOD treatment because of their unique ability to satisfy both nicotine cravings and behavioural habits. However, multiple barriers, such as accessibility, maintenance, and the challenges of reducing other substance use simultaneously also need to be addressed for optimal engagement in clinical trials with VNPs to quit smoking.

Evaluation of an Employment Intervention for Veterans Transitioning From the Military: A Randomized Controlled Trial.

ABSTRACT: Military personnel face numerous challenges transitioning from military jobs to meaningful civilian employment. The Independence Project compared an innovative employment program (National Career Coach Program) with standard employment services (Local Community Resources) in a randomized controlled trial. Study participants were transitioning veterans with self-reported service-connected disabilities seeking permanent employment. The primary outcomes were paid employment and disability ratings over 1 year. Secondary outcomes included health and well-being. At 1-year follow-up, National Career Coach Program participants were significantly more likely to work, had significantly greater earnings, and reported significantly greater improvements in physical and mental health compared with participants assigned to Local Community Resources. Both groups increased in disability ratings over 12 months, with no difference between groups. Multifaceted supports delivered by the National Career Coach Program increased employment, earnings, mental health, and physical health over 1 year. These significant differences appeared even though control group participants achieved considerable employment success.

Pauli blocking of atom-light scattering.

Transition rates between coupled states in a quantum system depend on the density of available final states. The radiative decay of an excited atomic state has been suppressed by reducing the density of electromagnetic vacuum modes near the atomic transition. Likewise, reducing the density of available momentum modes of the atomic motion when it is embedded inside a Fermi sea will suppress spontaneous emission and photon scattering rates. Here we report the experimental demonstration of suppressed light scattering in a quantum degenerate Fermi gas. We systematically measured the dependence of the suppression factor on the temperature and Fermi energy of a strontium quantum gas and achieved suppression of scattering rates by up to a factor of 2 compared with a thermal gas.