Thermography of the superfluid transition in a strongly interacting Fermi gas.

Heat transport can serve as a fingerprint identifying different states of matter. In a normal liquid, a hotspot diffuses, whereas in a superfluid, heat propagates as a wave called "second sound." Direct imaging of heat transport is challenging, and one usually resorts to detecting secondary effects. In this study, we establish thermography of a strongly interacting atomic Fermi gas, whose radio-frequency spectrum provides spatially resolved thermometry with subnanokelvin resolution. The superfluid phase transition was directly observed as the sudden change from thermal diffusion to second-sound propagation and is accompanied by a peak in the second-sound diffusivity. This method yields the full heat and density response of the strongly interacting Fermi gas and therefore all defining properties of Landau's two-fluid hydrodynamics.

Crystallization of bosonic quantum Hall states in a rotating quantum gas.

The dominance of interactions over kinetic energy lies at the heart of strongly correlated quantum matter, from fractional quantum Hall liquids1, to atoms in optical lattices2 and twisted bilayer graphene3. Crystalline phases often compete with correlated quantum liquids, and transitions between them occur when the energy cost of forming a density wave approaches zero. A prime example occurs for electrons in high-strength magnetic fields, where the instability of quantum Hall liquids towards a Wigner crystal4-9 is heralded by a roton-like softening of density modulations at the magnetic length7,10-12. Remarkably, interacting bosons in a gauge field are also expected to form analogous liquid and crystalline states13-21. However, combining interactions with strong synthetic magnetic fields has been a challenge for experiments on bosonic quantum gases18,21. Here we study the purely interaction-driven dynamics of a Landau gauge Bose-Einstein condensate22 in and near the lowest Landau level. We observe a spontaneous crystallization driven by condensation of magneto-rotons7,10, excitations visible as density modulations at the magnetic length. Increasing the cloud density smoothly connects this behaviour to a quantum version of the Kelvin-Helmholtz hydrodynamic instability, driven by the sheared internal flow profile of the rapidly rotating condensate. At long times the condensate self-organizes into a persistent array of droplets separated by vortex streets, which are stabilized by a balance of interactions and effective magnetic forces.

Disparities in clinical and demographic characteristics among Asian/Pacific Islander and Non-Hispanic White newly diagnosed lung cancer patients.

PURPOSE: Racial disparities persist among lung cancer patients but have not been adequately studied among Asian/Pacific Islander (API) subgroups, which are heterogeneous. This study compared clinical and demographic characteristics at diagnosis of API subgroups and NHW patients. METHODS: NHW and API adults diagnosed with lung cancer were identified from the Surveillance, Epidemiology, and End Results database (1990-2015). API was divided into eight subgroups: Chinese, Japanese, Filipino, Hawaiian/Pacific Islander, Korean, Vietnamese, Asian Indian/Pakistani, and Other. Multivariable multinomial logistic regression models were used to assess adjusted associations of clinical and demographic factors with API/subgroups. RESULTS: There were 522,702 (92.6%) NHW and 41,479 (7.4%) API lung cancer patients. API were less likely to be diagnosed at the age of ≥ 80 years (ORadj 0.53, 95% CI 0.48-0.58 for ≥ 80 vs. ≤ 39 years) than NHW. However, Japanese patients were more often diagnosed at ≥ 80 years compared to other ethnic subgroups. API were less often female (ORadj 0.85, 95% CI 0.83-0.86), and unmarried (ORadj 0.71, 95% CI 0.68-0.74); however, among API, Japanese, Hawaiian/Pacific Islander, Korean, and Vietnamese were more often unmarried, compared to Chinese patients. API were more frequently diagnosed at stage IV, compared to stage I (ORadj 1.31, 95% CI 1.27-1.35). API had significantly less squamous cell carcinoma (ORadj 0.54, 95% CI 0.52-0.56, compared to adenocarcinoma); among API, Japanese, Filipino, Hawaiian/Pacific Islander, Korean, Asian Indian/Pakistani, and Other were more likely than Chinese patients to present with squamous cell histology (range: ORadj[Other] 1.24, 95% CI 1.09-1.41; ORadj[Hawaiian/Pacific Islander] 2.47, 95% CI 2.22-2.75). CONCLUSION: At diagnosis, there are significant differences in demographic and clinical characteristics between NHW, API, and API subgroups. Treating API patients as a single population may overlook biological, environmental, and behavioral differences that might be beneficial in designing prevention strategies and treatment.

Short-term aspirin and statin chemoprophylaxis did not reduce the risk of developing advanced adenomatous polyps in Black patients.

BACKGROUND: Chemoprevention of colorectal neoplasia with aspirin and statins is under-investigated in Black patients. Since Black patients suffer disproportionately from colon cancer incidence and mortality compared to other populations, we investigated the utility of aspirin and statin in reducing advanced adenomatous polyp (AAP) risk in Black patients. METHODS: We carried out a retrospective cohort study of screening colonoscopies performed at a large urban academic center from 1/1/2011 through 12/31/2019. We analyzed self-identified Black patients with > 1 colonoscopy and no personal history of either inflammatory bowel disease or colon cancer syndromes. Our primary endpoint was first AAP development after index colonoscopy among Black patients taking both aspirin and a statin compared to those taking one or neither medication. We used multivariate logistic regression modeling to investigate our outcomes. RESULTS: We found data on chemoprophylaxis use in 560 patients. The mean observation period between index colonoscopy and AAP identification was 4 years. AAP developed in 106/560 (19%) of our cohort. We found no difference in AAP risk among Black patients taking both chemoprevention medications compared to partial or no chemoprophylaxis (20% vs 18% respectively, p = 0.49). This finding remained after adjusting for age, body mass index, and tobacco use (odds ratio 1.04, 95% CI 0.65-1.67; p = 0.87). CONCLUSIONS: Short-term aspirin-statin chemoprevention did not reduce the risk of AAP development in our cohort of Black patients. Larger and long-term prospective investigations are needed to investigate the utility of chemoprophylaxis in this population. TRIAL REGISTRATION: Not applicable.

Geometric squeezing into the lowest Landau level.

The equivalence between particles under rotation and charged particles in a magnetic field relates phenomena as diverse as spinning atomic nuclei, weather patterns, and the quantum Hall effect. For such systems, quantum mechanics dictates that translations along different directions do not commute, implying a Heisenberg uncertainty relation between spatial coordinates. We implement squeezing of this geometric quantum uncertainty, resulting in a rotating Bose-Einstein condensate occupying a single Landau gauge wave function. We resolve the extent of zero-point cyclotron orbits and demonstrate geometric squeezing of the orbits' centers 7 decibels below the standard quantum limit. The condensate attains an angular momentum exceeding 1000 quanta per particle and an interatomic distance comparable to the cyclotron orbit. This offers an alternative route toward strongly correlated bosonic fluids.

Universal sound diffusion in a strongly interacting Fermi gas.

Transport of strongly interacting fermions is crucial for the properties of modern materials, nuclear fission, the merging of neutron stars, and the expansion of the early Universe. Here, we observe a universal quantum limit of diffusivity in a homogeneous, strongly interacting atomic Fermi gas by studying sound propagation and its attenuation through the coupled transport of momentum and heat. In the normal state, the sound diffusivity D monotonically decreases upon lowering the temperature, in contrast to the diverging behavior of weakly interacting Fermi liquids. Below the superfluid transition temperature, D attains a universal value set by the ratio of Planck's constant and the particle mass. Our findings inform theories of fermion transport, with relevance for hydrodynamic flow of electrons, neutrons, and quarks.

Spectral Response and Contact of the Unitary Fermi Gas.

We measure radio frequency (rf) spectra of the homogeneous unitary Fermi gas at temperatures ranging from the Boltzmann regime through quantum degeneracy and across the superfluid transition. For all temperatures, a single spectral peak is observed. Its position smoothly evolves from the bare atomic resonance in the Boltzmann regime to a frequency corresponding to nearly one Fermi energy at the lowest temperatures. At high temperatures, the peak width reflects the scattering rate of the atoms, while at low temperatures, the width is set by the size of fermion pairs. Above the superfluid transition, and approaching the quantum critical regime, the width increases linearly with temperature, indicating non-Fermi-liquid behavior. From the wings of the rf spectra, we obtain the contact, quantifying the strength of short-range pair correlations. We find that the contact rapidly increases as the gas is cooled below the superfluid transition.

All-Cause 30-Day Mortality After Surgical Treatment for Head and Neck Squamous Cell Carcinoma in the United States.

OBJECTIVES: Thirty-day (30-day) mortality, a common posttreatment quality metric, is yet to be described following surgery for head and neck squamous cell carcinoma (HNSCC). This study aimed to measure 30-day postoperative mortality in HNSCC and describe clinical/nonclinical factors associated with 30-day mortality. METHODS: In this retrospective cohort study, the National Cancer Database (2004 to 2013) was queried for eligible cases of HNSCC (n=91,858). Adult patients were included who were treated surgically with curative intent for the primary HNSCC, not missing first treatment, survival, and follow-up information. The outcome of interest was all-cause mortality within 30 days of definitive surgery. Clinical and nonclinical factors associated with all-cause 30-day postoperative mortality were estimated using a fully adjusted, multivariable logistic regression, which accounted for time-varying nature of adjuvant therapy. RESULTS: A total of 775 patients died within 30 days of definitive surgery for HNSCC (30-day mortality rate of 0.84%). Thirty-day mortality rate was however up to 2.33% (95% confidence interval [CI], 1.91%-2.75%) depending on comorbidity. In the fully adjusted model, increasing severity of comorbidity was associated with greater odds of 30-day mortality (Charlson-Deyo comorbidity scores of 1: adjusted odds ratio [aOR], 1.43; 95% CI, 1.21-1.69, and of 2+ aOR, 2.55; 95% CI, 2.07-3.14). Odds of 30-day mortality were greater among Medicaid patients (aOR, 1.77; 95% CI, 1.30-2.41), and in patients in neighborhoods with little education (≥ 29% missing high school diploma: aOR, 1.35; 95% CI, 1.02-1.78). CONCLUSIONS: Patients with higher 30-day mortality were those with a greater burden of comorbidities, with little education, and covered by Medicaid.

Unhelmeted Motorcycle Riders Have Increased Injury Burden: A Need to Revisit Universal Helmet Laws.

BACKGROUND: The aim of this study was to compare hospital outcomes for patients in a motorcycle collision with and without helmet use. The study was conducted as a retrospective analysis of the National Trauma Data Bank's 2013 data set, which included reported data from 100 hospitals across the United States. METHODS: Inclusion criterion for this study is a motorcycle crash involving a driver or passenger. The total number of patients in motorcycle crashes as reported by the National Trauma Data Bank in 2013 was 10,345. Helmet use, hospital stay, ICU and ventilation days, mortality, Glasgow Coma Score, Injury Severity Score, patient payer mix, and complication data were obtained. RESULTS: Patients were divided into two groups: those wearing a helmet (n = 6250) and those without (n = 4095). Patients not wearing a helmet had an increased risk of admission to the ICU (OR = 1.36, P < 0.001, CI 1.25-1.48), requiring ventilation support (OR = 1.55, P < 0.001, CI 1.39-1.72), presenting with a Glasgow Coma Score of eight or below (OR = 2.15, P < 0.001), and in-patient mortality (OR = 2.00, P < 0.001, CI 1.58-2.54). Unhelmeted patients were more likely to have government insurance or be uninsured than those patients wearing a helmet (P < 0.001). CONCLUSIONS: It is not well understood why many states are repealing or have repealed universal helmet laws. Lack of helmet use increases the severity of injury in traumatized patients leading to a substantial financial impact on health care costs. Our analysis suggests the need to revisit the issue regarding laws that require protective headwear while riding motorcycles because of the individual and societal impact. LEVEL OF EVIDENCE: III.

Boiling a Unitary Fermi Liquid.

We study the thermal evolution of a highly spin-imbalanced, homogeneous Fermi gas with unitarity limited interactions, from a Fermi liquid of polarons at low temperatures to a classical Boltzmann gas at high temperatures. Radio-frequency spectroscopy gives access to the energy, lifetime, and short-range correlations of Fermi polarons at low temperatures T. In this regime, we observe a characteristic T^{2} dependence of the spectral width, corresponding to the quasiparticle decay rate expected for a Fermi liquid. At high T, the spectral width decreases again towards the scattering rate of the classical, unitary Boltzmann gas, ∝T^{-1/2}. In the transition region between the quantum degenerate and classical regime, the spectral width attains its maximum, on the scale of the Fermi energy, indicating the breakdown of a quasiparticle description. Density measurements in a harmonic trap directly reveal the majority dressing cloud surrounding the minority spins and yield the compressibility along with the effective mass of Fermi polarons.

The Hoffa fracture: Coronal fracture of the femoral condyle a review of literature.

This article aims to provide a systematic review of the limited literature and clinical knowledgebase available on the Hoffa fractures. It is inclusive of the normal anatomy, pathology, diagnosis, treatment options comprising of non-operative and operative protocols, and postoperative findings.

Homogeneous Atomic Fermi Gases.

We report on the creation of homogeneous Fermi gases of ultracold atoms in a uniform potential. In the momentum distribution of a spin-polarized gas, we observe the emergence of the Fermi surface and the saturated occupation of one particle per momentum state: the striking consequence of Pauli blocking in momentum space for a degenerate gas. Cooling a spin-balanced Fermi gas at unitarity, we create homogeneous superfluids and observe spatially uniform pair condensates. For thermodynamic measurements, we introduce a hybrid potential that is harmonic in one dimension and uniform in the other two. The spatially resolved compressibility reveals the superfluid transition in a spin-balanced Fermi gas, saturation in a fully polarized Fermi gas, and strong attraction in the polaronic regime of a partially polarized Fermi gas.

Development and validation of a method for simultaneous estimation of ofloxacin and ornidazole in different dissolution media.

INTRODUCTION: Ofloxacin and ornidazole in a combined tablet dosage form is available in the market. This combination has gained increasing acceptance in diarrhea caused due to bacterial and protozoal infections. Ofloxacin and ornidazole are also combined in the capsule dosage form to modify its release pattern in different studies. Spectrophotometric and HPTLC methods have been reported for their simultaneous estimation in the tablet dosage form in specific solvents. This paper presents a simple, accurate, and reproducible spectrophotometric method for simultaneous estimation of ofloxacin and ornidazole in the tablet dosage form in different dissolution media. The reported method is helpful in determination of ofloxacin and ornidazole during a dissolution study. MATERIALS AND METHODS: A simple, sensitive, accurate, and economical spectrophotometric method based on the simultaneous equation was developed for the estimation of ornidazole and ofloxacin simultaneously in the tablet or capsule dosage form in different dissolution media at different pH values. RESULTS: Ofloxacin showed absorption maxima at 294 nm in 0.1 N HCl and at 287 nm in phosphate buffer pH 6.8 and phosphate buffer pH 7.4 while ornidazole showed absorption maxima at 277 nm in 0.1 N HCl and at 319 nm in two buffers, respectively. The linearity was obtained in the concentration range of 1-8 µg/ ml for ofloxacin and 4-26 µg/ml for ornidazole. DISCUSSION: The concentrations of the drugs were determined by the simultaneous equation method. The results of analysis have been validated statistically and by recovery studies.

Formulation and evaluation of sublingual tablets containing Sumatriptan succinate.

OBJECTIVE: Sumatriptan succinate is a selective 5-hydroxytryptamine-1 receptor agonist effective in the acute treatment of migraine headaches, having low bioavailability of about 15% orally due to first-pass metabolism. The purpose of this research was to mask the intensely bitter taste of Sumatriptan succinate and to formulate fast-acting, taste-masked sublingual tablet formulation. MATERIALS AND METHODS: Taste masking was performed by solid dispersion method with mannitol and ion exchange with Kyron T 114 because it releases the drug in salivary pH. The resultant batches were evaluated for in-vivo taste masking as well compatability study (Fourier transform infrared (FTIR) and differential scanning calorimetry (DSC)). For a better feel in the mouth, menthol and sweetener Na saccharine were added to the tablet formulation. The tablets were prepared by direct compression and evaluated for weight variation, thickness, friability, drug content, hardness, disintegration time, wetting time, in vitro drug release, and in vitro permeation study. RESULTS AND DISCUSSION: Optimized batches disintegrated in vitro within 28-34 s. Maximum drug release could be achieved with in 10 min for the solid dispersion batches and 14-15 min for the ion-exchange batches with Kyron T 114. The optimized tablet formulation showed better taste and the formulated sublingual tablets may act as a potential alternate for the Sumatriptan succinate oral tablet. CONCLUSION: Sumatriptan succinate can be successfully taste-masked by both the solid dispersion method using mannitol by the melting method and Ion exchange resin with Kyron T114. It was also concluded that prepared formulation improve bioavailability by prevention of first pass metabolism.