Epithelial plasticity in COPD results in cellular unjamming due to an increase in polymerized actin.

The airway epithelium is subjected to insults such as cigarette smoke (CS), a primary cause of chronic obstructive pulmonary disease (COPD) and serves as an excellent model to study cell plasticity. Here, we show that both CS-exposed and COPD-patient derived epithelia (CHBE) display quantitative evidence of cellular plasticity, with loss of specialized apical features and a transcriptional profile suggestive of partial epithelial-to-mesenchymal transition (pEMT), albeit with distinct cell motion indicative of cellular unjamming. These injured/diseased cells have an increased fraction of polymerized actin, due to loss of the actin-severing protein cofilin-1. We observed that decreasing polymerized actin restores the jammed state in both CHBE and CS-exposed epithelia, indicating that the fraction of polymerized actin is critical in unjamming the epithelia. Our kinetic energy spectral analysis suggests that loss of cofilin-1 results in unjamming, similar to that seen with both CS exposure and in CHBE cells. The findings suggest that in response to chronic injury, although epithelial cells display evidence of pEMT, their movement is more consistent with cellular unjamming. Inhibitors of actin polymerization rectify the unjamming features of the monolayer. This article has an associated First Person interview with the first author of the paper.

Time-resolved turbulent dynamo in a laser plasma.

Understanding magnetic-field generation and amplification in turbulent plasma is essential to account for observations of magnetic fields in the universe. A theoretical framework attributing the origin and sustainment of these fields to the so-called fluctuation dynamo was recently validated by experiments on laser facilities in low-magnetic-Prandtl-number plasmas ([Formula: see text]). However, the same framework proposes that the fluctuation dynamo should operate differently when [Formula: see text], the regime relevant to many astrophysical environments such as the intracluster medium of galaxy clusters. This paper reports an experiment that creates a laboratory [Formula: see text] plasma dynamo. We provide a time-resolved characterization of the plasma's evolution, measuring temperatures, densities, flow velocities, and magnetic fields, which allows us to explore various stages of the fluctuation dynamo's operation on seed magnetic fields generated by the action of the Biermann-battery mechanism during the initial drive-laser target interaction. The magnetic energy in structures with characteristic scales close to the driving scale of the stochastic motions is found to increase by almost three orders of magnitude and saturate dynamically. It is shown that the initial growth of these fields occurs at a much greater rate than the turnover rate of the driving-scale stochastic motions. Our results point to the possibility that plasma turbulence produced by strong shear can generate fields more efficiently at the driving scale than anticipated by idealized magnetohydrodynamics (MHD) simulations of the nonhelical fluctuation dynamo; this finding could help explain the large-scale fields inferred from observations of astrophysical systems.

Effects of Crude Oil Properties and Dispersant on the Microstructure and Viscosity of Seawater-in-Oil Emulsions.

This study examines the effects of crude oil properties and dispersant concentration (Corexit 9500) on the evolution of bulk viscosity, viscoelastic properties, and microstructure of salt water-in-crude oil emulsions. Microscopy, followed by machine-learning-based analysis, provides the size and spatial distribution of the seawater droplets. The crude oils include light Bakken, Alaskan North Slope (ANS), and Louisiana oils, and medium to heavy Platform Henry, Cold Lake, and Platform Gina oils. The light and medium oils entrain water up to 80% by volume, and the heavy oils, up to 25%. The droplet sizes and distance between them decrease with increasing viscosity, with small droplets clustering around larger ones. The Bakken- and ANS-based emulsions are unstable, but all of the emulsions evolve in time. All exhibit a non-Newtonian behavior, with the viscosity decreasing with increasing shear rate. The storage modulus is higher than the loss modulus for light oils, and vice versa for heavy oils. Trends of their nondimensional viscosity are collapsed onto two power laws as a function of the Ohnesorge number involving the properties of the original oil, and the size or distance between droplets. For light oils, the power law exponent decreases with increasing capillary number based on the rheometer shear rate and increases for heavy oils. At high shear rates, the exponents converge to the same value, 0.45, suggesting that the oil viscosity becomes the property that defines the emulsion rheology. The present findings are consistent with previously published data. Premixing the emulsions with dispersant causes separation of most of the water from the light oils, leaving only sparse droplet concentrations. In contrast, owing to slow diffusion rate, only a small fraction of the seawater is extracted from the heavy oil emulsions. Hence, the sparse light oil emulsions become Newtonian, but the heavy ones remain non-Newtonian.

A lower prevalence of malignant lymphoma in Sjögren's syndrome patients: A cross-sectional study.

OBJECTIVE: This study aims to determine the prevalence and risk factors associated with lymphoma in primary Sjögren's syndrome (pSS). METHODS: We conducted a cross-sectional study on pSS patients who were registered into the Integrated Data Repository (IDR) at the University of Florida (UF) Health Shands Hospital. The parameters, such as age, sex, race, and smoking status, were included. Lymphoma types in pSS were categorized. The clinical and laboratory features were compared between pSS patients with and those without lymphoma by utilizing the items in the EULAR Sjögren's Syndrome Disease Activity Index (ESSDAI). RESULTS: Among 1,211,343 patients, we found 6799 patients (0.56%) with lymphomas and 2562 patients (0.21%) with pSS. Out of the 2562 pSS patients, 67 patients (2.6%) were diagnosed with lymphoma. The difference in the clinical and laboratory features listed under the ESSDAI domains between pSS patients with lymphomas and pSS without it was significant (p < 0.05 or 0.01): fever, weight loss, lymphadenopathy, splenomegaly, lacrimal gland diseases, cough, shortness of breath, hematuria, cerebrovascular accident diseases, peripheral nerve involvement due to vasculitis, neutropenia, and thrombocytopenia. CONCLUSION: We report 2.6% of lymphoma prevalence in pSS, lower than previously reported in the literature.

Localization and characterization of human papillomavirus-16 in oral squamous cell carcinoma.

OBJECTIVES: The role of Human papillomavirus (HPV) in the oral squamous cell carcinoma (OSCC) has not been completely elucidated. The purpose of the present study was to investigate the prevalence and localization of HPV-16 virus in OSCC and to correlate HPV-16 positivity and p16INK4A expression with the clinical and pathological features of OSCC. METHODS: The archives of Oral Pathology at the University of Florida, College of Dentistry were accessed for demographic, clinical, histopathological data, and slides of 114 OSCC patients. HPV-16 positivity of OSCC was evaluated by p16INK4A immunohistochemistry (IHC) and HPV-16 E6/E7mRNA by in situ hybridization (ISH). RESULTS: Out of 114 consecutive pathological slides of OSCC, 16 samples (14%) showed positivity for p16INK4A by IHC and 14 samples (12%) were positive for HPV-16 E6/E7mRNA ISH and the Positivity showed a significant correlation with the patients' age, alcohol consumption, and the degree of OSSC differentiation. The hard palate showed the highest positivity of p16INK4A IHC and HPV-16 mRNA ISH (38%, 36% respectively). CONCLUSION: HPV-16 is a significant factor in oral carcinogenesis. We recommend using p16INK4A as a surrogate marker for HPV detection in OSCC, which can be complemented by RNA ISH for the identification of HPV subtypes.

Increased odds for COVID-19 infection among individuals with periodontal disease.

OBJECTIVES: Periodontal disease has been linked to multiple systemic conditions, but the relationship with COVID-19 still needs to be elucidated. We hypothesized that periodontal disease may be associated with COVID-19 infection. MATERIALS AND METHODS: This study utilized cross-sectional data to establish the strength of the association between periodontal disease and COVID-19 infection. The University of Florida Health Center's i2b2 patient's registry was used to generate patient counts through ICD-10 diagnostic codes. Univariate descriptive statistics of the patient population and logistic regression to estimate odds ratios of associations between periodontal disease and COVID-19 infection were used for analysis. RESULTS: Patients with periodontal disease were 4.4 times more likely to be positively diagnosed with COVID-19 than patients without PD. Associations remained similar and robust (P value < 0.0001) after adjustment for age (OR = 4.34; 95% CI, 3.68-5.09), gender (OR = 4.46; 95% CI, 3.79-5.23), and smoking status (OR = 4.77; 95% CI, 4.04-5.59). Associations were smaller but remained robust (P value < 0.0001) after adjusting for race (OR = 2.83; 95% CI, 2.40-3.32), obesity (OR = 2.53; 95% CI, 2.14-2.98), diabetes (OR = 3.32; 95% CI, 2.81-3.90), and cardiovascular disease (OR = 2.68; 95% CI, 2.27-3.14). CONCLUSIONS: Periodontal disease is significantly associated with increased odds for COVID-19 infection. CLINICAL RELEVANCE: With the caveat of a cross-sectional study design, these results suggest that periodontal disease may increase the odds for COVID-19 infection.

Beam Spray Thresholds in ICF-Relevant Plasmas.

Beam spray measurements suggest thresholds that are a factor of ≈2 to 15× less than expected based on the filamentation figure of merit often quoted in the literature. In this moderate-intensity regime, the relevant mechanism is forward stimulated Brillouin scattering. Both weak ion acoustic wave damping and thermal enhancement of ion acoustic waves contribute to the low thresholds. Forward stimulated Brillouin scattering imparts a redshift to the transmitted beam. Regarding the specific possibility of beam spray occurring outside the laser entrance holes of an indirectly driven hohlraum, this shift may be the most concerning feature owing to the high sensitivity of crossed-beam energy transfer to the interacting beam wavelengths in the subsequent overlap region.

Medication-related osteonecrosis of the jaw: A multifaceted diagnostic challenge. Mini review.

RESULTS: Medication-related osteonecrosis of the jaw (MRONJ) may present a challenge to the dental clinician due to the many presentations that it can have. This condition can be caused by multiple medications including bisphosphonates, RANKL ligand inhibitors and antiangiogenic drugs. Cases were reported in multiple sites of both the maxilla and mandible, including the hard palate, mylohyoid area, and the buccal plate. The risk factors for this condition include the use of a combination of antiresorptive medications, trauma, periodontal disease, immunosuppression, dental trauma, dental extractions, and bone manipulations. Spontaneous MRONJ have been reported in about half of the cases. Conventional radiographs are not conducive to a diagnosis, underscoring the importance of a three-dimensional modality in the diagnosis of MRONJ. The multifaceted diagnostic challenges of MRONJ are underscored in this mini review. CLINICAL SIGNIFICANCE: MRONJ can have diverse presentations and a lengthy multisite involvement. Therefore, long-term follow up for patients with history of use of antiresorptive medications is recommended.

Glossodynia, burning mouth syndrome, and COVID-19.

PURPOSE: To evaluate whether the prevalence of glossodynia increased among patients affected by COVID-19 compared to other hospital populations. METHODS: The i2b2 patient registry platform at the University of Florida Health Center was used to generate a count of patients using the international classification of diseases (ICD)-10 diagnosis codes from October 2015 to June 2021. Logistic regression of the aggregates was used for analysis. RESULTS: Of the patients with both glossodynia and COVID-19, 60% were females, 32% were African American, 64% were white, and 100% were adults. There were 72% females, 19% African Americans, 72% whites, and 93% adults with glossodynia only. For COVID-19 patients, 57% were females, 23% were African American, 56% whites, and 90% were adults. The odds ratio (OR) for glossodynia in the COVID-19 patients was significant (OR = 2.9; 95% CI, 1.94-4.32; P < 0.0001). CLINICAL SIGNIFICANCE: Glossodynia is significantly more common in COVID-19 patients and should be considered in the differential diagnoses among the oral complications of this infection.

Periapical disease in post-stroke patients.

PURPOSE: To assess the prevalence of acute periapical abscesses (PAs) in patients with history of stroke. METHODS: Integrated data of hospital patients was used. Data from the corresponding diagnosis codes for PAs and stroke were retrieved by searching the appropriate query in the database. The odds ratio (OR) of acute PAs and its association with post-stroke conditions was calculated and analyzed statistically. RESULTS: The prevalence of acute PAs in patients with stroke history was 1.39% as compared to 0.6% in the general patient population of the hospital. The OR was 2.78 and the difference was statistically significant (P< 0.0001). The prevalence of acute PAs in patients with a history of hemorrhagic stroke was 1.19% and the OR was 2.38. The difference was statistically significant (P< 0.0001). The prevalence of acute PAs in patients with a history of cerebral infarction was 1.55% and the OR was 3.11. The difference was statistically significant (P< 0.0001). The prevalence of acute PAs in patients with a history of cerebral infarction without hypertension was 0.87% and the OR was 1.75. The difference was statistically significant (P< 0.0001). CLINICAL SIGNIFICANCE: Oral healthcare providers should be aware of the possible higher prevalence of periapical abscesses in post-stroke patients. This can include patients with a history of hemorrhagic stroke or cerebral infarction.

Time Evolution and Effect of Dispersant on the Morphology and Viscosity of Water-In-Crude-Oil Emulsions.

This study examines the time evolution and effects of adding dispersant (Corexit 9500A) at varying concentrations on the microscopic morphology and bulk viscosity of saltwater-in-crude-oil (Louisiana) mechanically mixed emulsions. Rheology is used for measuring the viscoelastic properties and viscosity, the latter at varying shear rates. Microscopy, followed by machine-learning-based analysis, is used for characterizing the size and spatial distribution of the water droplets in the emulsions. Initially, the water droplets appear as a multiscale lattice with a Sauter diameter of 5.3 µm and a polydispersity of 0.43, with small droplets aggregating around large ones. The corresponding bulk viscosity decreases with increasing shear rate from 2 orders of magnitude to 5 times higher than that of the weathered crude oil. After 7 days, the number of submicron droplets increases, the nearest-neighbor distance decreases, indicating preferential aggregation, and the viscosity increases by 56-112% at high shear rates (5-100 s-1). After 14 and 21 days, some droplets coalesce resulting in loss of clusters and a decrease in viscosity. These trends suggest that changes in the aggregation contribute to the variations in viscosity. Subsequent analysis applies previously developed models for the effect of aggregation on the properties of the emulsion. While the reduction in viscosity is predicted by this model, matching of rates requires modification to the assumed relationship between yield stress and interdroplet forces. Adding dispersant without mixing generates Marangoni-driven flows as the water droplets coalesce. In time, part of the water separates, a fraction forms clouds of submicron droplets, and the rest remains unchanged. Mixing dispersant at low concentration with the emulsion accelerates the coalescence and phase separation. The removed water fraction increases with dispersant concentration, reaching 99.6% for a dispersant-to-emulsion concentration of 10-3. The remaining emulsion consists of fine droplets with Newtonian viscosity that is still 4 times higher than that of the fresh crude oil but only 14% higher than that of the weathered oil.

Effect of Oil Properties on the Generation of Nano-Aerosols During Bubble Bursting Through Crude Oil-Dispersant Slicks.

This study examines the effect of dispersant and oil properties on the aerosolization of fresh and weathered surface crude oil slicks by bursting of a plume of ∼0.7 mm bubbles. A scanning mobility particle sizer measures the size distribution of aerosols in the 20-400 nm range in a clean air chamber. The 500-µm-thick slicks contain oils with varying origin, viscosity, interfacial tension, and weathering state. Test are performed with and without premixed dispersant (Corexit 9500A), which reduces the oil-seawater interfacial tension by 2 orders of magnitude at a dispersant-to-oil ratio (DOR) of 1:25. When compared to aerosolization in clean seawater, the nano-aerosol concentration decreases for slicks without dispersant but increases by 27%-351% upon introduction of dispersant. For most cases, the airborne nanodroplet concentration increases with decreasing Capillary or Morton numbers as well as the ratio of the so-called inner to thermal length scales. To explain the airborne nanodroplet generation in an oil-dispersant mixture, we show that prior to bubble injection, even minimal agitation of the interface causes generation of a subsurface cloud of nanodroplets that diffuses away from the interface. This process appears to be caused by thermal capillary instability when the interfacial tension is low enough to increase the thermal length scale to a few nanometers.

The impact of HPV vaccination on the prevalence of oropharyngeal cancer (OPC) in a hospital-based population: A cross-sectional study of patient's registry.

BACKGROUND: Human papillomavirus (HPV) vaccines have been used for the prevention of cervical cancers, and their clinical efficacy has not been well established in the prevention of oropharyngeal cancer (OPC), in spite of the common viral etiology. Therefore, they are still not routinely prescribed for the prevention of this cancer. METHODS: We have used the i2b2 data repository to analyze the interrelations between the hospital population, OPC, vaccinated patients, and patients that were both vaccinated and developed OPC. RESULTS: From a total hospital population of 1 310 334 patients, 23 174 (1.76%) patients were vaccinated for HPV. One third were males, and two thirds were females. The total number of OPC was 4380 (0.3%) from the total population, of which 3013 (69%) were men. The highest prevalence of OPC was found in the age-group of 65-74 (37% of all cases). Four patients (0.017%) of the vaccinated group had developed OPC. Patients who were not vaccinated for HPV had a 19 times increased risk of developing OPC compared with those who were vaccinated (RR 19.3657, 95% CI 7.2655 to 51.6177, P = .0001). The risk was increased in both sexes. The RR in the male group was 23.8 (P = .0015, 95% CI) and in the female group 9.34 (P = .0001, 95% CI 3.0110 to 29.0121). The age distribution in the OPC group was significantly different from the age distribution in the HPV-vaccinated group (P = .0418) by Mann-Whitney test. 4376 non-vaccinated patients have developed OPC. CONCLUSIONS: The present study showed that HPV-vaccinated group had a reduced prevalence of OPC compared with the non-vaccinated group.

Increased odds ratio for COVID-19 in patients with recurrent aphthous stomatitis.

The ACE2 receptor, the binding sites for the COVID-19, is expressed abundantly in the oral cavity, raising the question of whether the mouth is a target for the virus in addition to organs such as kidneys and lungs. Recently, a flurry of individual case reports on oral manifestation of COVID-19 including ulceration, blistering lesions, and stomatitis were published. However, it is not clear whether the oral presentations that are not unique to the virus are indeed related to the virus and appear at a higher prevalence than in the general population. We used the i2b2 platform of hospital patient's registry to determine the odds ratio for COVID-19 in patients that were diagnosed with recurrent aphthous stomatitis, an entity restricted to the oral cavity. The overall odds ratio for COVID-19 in patients with recurrent aphthous stomatitis before adjustments was 14 and after adjustment for gender, race, and age was 13.9, 6.5, and 2.93, respectively. The odds ratio remained increased after adjustments of the comorbidities such as respiratory disease, endocrine disease, obesity, diabetes, circulatory disease, and smoking and was 3.66, 7.46, 4.6, 10.54, 7.37, and 7.52, respectively. When adjusted for recurrent aphthous stomatitis, the respiratory disease had an odd ratio of 8.56 to be associated with COVID-19. African American race and age-group 18-34 were additional significant risk factors. The present study has demonstrated a significant association between COVID-19 and RAS; however, additional longitudinal and laboratory studies are necessary to establish a cause and effect relationship between these 2 conditions.

Time-Resolved Echo-Particle Image/Tracking Velocimetry Measurement of Interactions Between Native Cardiac Output and Veno-Arterial ECMO Flows.

Determination of optimal hemodynamic and pressure-volume loading conditions for patients undergoing veno-arterial extracorporeal membrane oxygenation (VA-ECMO) would benefit from understanding the impact of ECMO flow rates (QE) on the native cardiac output in the admixing zone, i.e., aortic root. This study characterizes the flow in the aortic root of a pig with severe myocardial ischemia using contrast-enhanced ultrasound particle image/tracking velocimetry (echo-PIV/PTV). New methods for data preprocessing are introduced, including autocontouring to remove surrounding tissues, followed by blind deconvolution to identify the centers of elongated bubble traces in images with low signal to noise ratio. Calibrations based on synthetic images show that this procedure increases the number of detected bubbles and reduces the error in their locations by 50%. Then, an optimized echo-PIV/PTV procedure, which integrates image enhancement with velocity measurements, is used for characterizing the time-resolved two-dimensional (2D) velocity distributions. Phase-averaged and instantaneous flow fields show that the ECMO flow rate influences the velocity and acceleration of the cardiac output during systole, and secondary flows during diastole. When QE is 3.0 L/min or higher, the cardiac ejection velocity, phase interval with open aortic valve, velocity-time integral (VTI), and mean arterial pressure (MAP) increase with decreasing QE, all indicating sufficient support. For lower QE, the MAP and VTI decrease as QE is reduced, and the deceleration during transition to diastole becomes milder. Hence, for this specific case, the optimal ECMO flow rate is 3.0 L/min.

Prevalence of periapical abscesses in vitamin D deficient patients.

PURPOSE: To assess the prevalence of periapical abscesses (PAs) in individuals with vitamin D deficiency who are not treated and in individuals treated with a vitamin D supplement (calciferol). METHODS: Integrated data of hospital patients was used. Data from the corresponding diagnosis codes for periapical abscess and vitamin D deficiency were retrieved by searching the appropriate query in the database. The Risk Ratio (RR) for periapical abscesses, its association with vitamin D deficiency and intake of calciferol were calculated and analyzed statistically. RESULTS: The RR for prevalence of periapical abscesses in patients with vitamin D deficiency was 3.44. Presence of PAs was significantly higher in patients with vitamin D deficiency compared to patients without vitamin D deficiency (P< 0.0001). The RR and the prevalence of PAs for patients treated with calciferol were significantly lower compared to untreated patients (P< 0.0001). CLINICAL SIGNIFICANCE: Dentists should be aware of the possible association between vitamin D deficiency and occurrence of periapical abscesses. It appears that the prevalence of periapical abscesses is higher in patients with vitamin D deficiency. Calciferol supplement may reduce the prevalence of such periapical disease in these patients.

Increased occurrence of temporomandibular joint disorders in COVID-19 confirmed patients.

PURPOSE: To examine the prevalence of temporomandibular joint disorders (TMJD) in COVID-19 confirmed patients before and after adjustments for risk factors such as fibromyalgia, nocturnal bruxism, and anxiety disorders. METHODS: The i2b2 database was used to query searches of patient records at University of Florida Health Centers. Queries were submitted for the number of total hospital patients, TMJD cases, COVID-19 cases, and TMJD with COVID-19 cases from December 2019 to July 2021. Additional searches excluded fibromyalgia, nocturnal bruxism, and anxiety to examine their prevalence as risk factors. RESULTS: Out of the 548,646 total hospital patients, 86 had a diagnosis of both COVID-19 and TMJD, 14,836 had only COVID-19, and 1,856 had only TMJD. The odds ratio (OR) for having TMJD with COVID-19 was 1.7, with around 80% of TMJD occurring in young adult females. Excluding fibromyalgia and nocturnal bruxism did not change the OR. Anxiety was present in 37% of COVID-19 with TMJD cases and exclusion of this population significantly diminished the odds ratio to 1.08. These results demonstrate a correlation between COVID-19 and TMJD that dissolves when adjusting for stress. Thus, anxiety is a significant factor in the prevalence of TMJD in COVID-19 patients. CLINICAL SIGNIFICANCE: COVID-19 positive patients demonstrate an increased risk of developing TMJD, with a correlation to stress and anxiety that should be addressed during treatment.

Prevalence of periapical abscesses in patients with rheumatoid arthritis. A cross sectional study.

PURPOSE: To assess the prevalence of periapical abscesses in patients with rheumatoid arthritis, and to evaluate the effect of commonly used antirheumatic medications on such prevalence. METHODS: Integrated data of hospital patients was used. Data from the corresponding diagnosis codes for rheumatoid arthritis and periapical abscess was retrieved by searching the appropriate query in the database. The odd ratio (OR) of periapical abscesses, its association with rheumatoid arthritis and intake of three commonly prescribed antirheumatic medications were calculated and analyzed statistically. RESULTS: The prevalence of periapical abscesses in patients with rheumatoid arthritis was 1.53% as compared to 0.51% in the general patient population of the hospital. The OR was 2.60 and the difference was statistically significant (P< 0.0001). In patients treated with either Methotrexate, Sulfasalazine, or Etanercept, the ORs were 2.88, 3.1, and 1.07, respectively. The differences between Methotrexate and Sulfasalazine were statistically significant (P< 0.0001). The OR for prevalence of periapical abscesses in patients treated with Etanercept was significantly lower than that of patients treated with either Methotrexate or Sulfasalazine (P< 0.005). CLINICAL SIGNIFICANCE: Oral healthcare providers should be aware of the possible association between rheumatoid arthritis and occurrence of periapical abscesses. Patients with rheumatoid arthritis, mainly women, may exhibit higher prevalence of periapical abscesses. Treatment with TNF alpha inhibitors may lower the prevalence of periapical abscesses in such patients.

Measurement and control of large diameter ionization waves of arbitrary velocity.

Large diameter, flying focus driven ionization waves of arbitrary velocity (IWAV's) were produced by a defocused laser beam in a hydrogen gas jet, and their spatial and temporal electron density characteristics were measured using a novel, spectrally resolved interferometry diagnostic. A simple analytic model predicts the effects of power spectrum non-uniformity on the IWAV trajectory and transverse profile. This model compares well with the measured data and suggests that spectral shaping can be used to customize IWAV behavior and increase controlled propagation of ionization fronts for plasma-photonics applications.

Band alignment in quantum wells from automatically tuned DFT+U.

Band alignment between two materials is of fundamental importance for a multitude of applications. However, density functional theory (DFT) either underestimates the bandgap - as is the case with the local density approximation (LDA) or generalized gradient approximation (GGA) - or is highly computationally demanding, as is the case with hybrid-functional methods. The latter can become prohibitive in electronic-structure calculations of supercells which describe quantum wells. We propose to apply the DFT+U method, with U for each atomic shell being treated as set of tuning parameters, to automatically fit the bulk bandgap and the lattice constant, and then use the thus obtained U parameters in large supercell calculations to determine the band alignment. We apply this procedure to InP/In0.5Ga0.5As, In0.5Ga0.5As/In0.5Al0.5As and InP/In0.5Al0.5As quantum wells, and obtain good agreement with experimental results. Although this procedure requires some experimental input, it provides both meaningful valence and conduction band offsets while, crucially, lattice relaxation is taken into account. The computational cost of this procedure is comparable to that of LDA. We believe that this is a practical procedure that can be useful for providing accurate estimates of band alignments between more complicated alloys.