Quantum Langevin theory of excess noise

In an earlier work [P. J. Bardroff and S. Stenholm], we have derived a fully quantum mechanical description of excess noise in strongly damped lasers. This theory is used here to derive the corresponding quantum Langevin equations. Taking the semi-classical limit of these we are able to regain the starting point of Siegman's treatment of excess noise [Phys. Rev. A 39, 1253 (1989)]. Our results essentially constitute a quantum derivation of his theory and allow some generalizations.Comment: 9 pages, 0 figures, revte

Influence of Coulomb and Phonon Interaction on the Exciton Formation Dynamics in Semiconductor Heterostructures

A microscopic theory is developed to analyze the dynamics of exciton formation out of incoherent carriers in semiconductor heterostructures. The carrier Coulomb and phonon interaction is included consistently. A cluster expansion method is used to systematically truncate the hierarchy problem. By including all correlations up to the four-point (i.e. two-particle) level, the fundamental fermionic substructure of excitons is fully included. The analysis shows that the exciton formation is an intricate process where Coulomb correlations rapidly build up on a picosecond time scale while phonon dynamics leads to true exciton formation on a slow nanosecond time scale.Comment: 18 pages, 7 figure

Risk profiles and one-year outcomes of patients with newly diagnosed atrial fibrillation in India: Insights from the GARFIELD-AF Registry.

BACKGROUND: The Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF) is an ongoing prospective noninterventional registry, which is providing important information on the baseline characteristics, treatment patterns, and 1-year outcomes in patients with newly diagnosed non-valvular atrial fibrillation (NVAF). This report describes data from Indian patients recruited in this registry. METHODS AND RESULTS: A total of 52,014 patients with newly diagnosed AF were enrolled globally; of these, 1388 patients were recruited from 26 sites within India (2012-2016). In India, the mean age was 65.8 years at diagnosis of NVAF. Hypertension was the most prevalent risk factor for AF, present in 68.5% of patients from India and in 76.3% of patients globally (P < 0.001). Diabetes and coronary artery disease (CAD) were prevalent in 36.2% and 28.1% of patients as compared with global prevalence of 22.2% and 21.6%, respectively (P < 0.001 for both). Antiplatelet therapy was the most common antithrombotic treatment in India. With increasing stroke risk, however, patients were more likely to receive oral anticoagulant therapy [mainly vitamin K antagonist (VKA)], but average international normalized ratio (INR) was lower among Indian patients [median INR value 1.6 (interquartile range {IQR}: 1.3-2.3) versus 2.3 (IQR 1.8-2.8) (P < 0.001)]. Compared with other countries, patients from India had markedly higher rates of all-cause mortality [7.68 per 100 person-years (95% confidence interval 6.32-9.35) vs 4.34 (4.16-4.53), P < 0.0001], while rates of stroke/systemic embolism and major bleeding were lower after 1 year of follow-up. CONCLUSION: Compared to previously published registries from India, the GARFIELD-AF registry describes clinical profiles and outcomes in Indian patients with AF of a different etiology. The registry data show that compared to the rest of the world, Indian AF patients are younger in age and have more diabetes and CAD. Patients with a higher stroke risk are more likely to receive anticoagulation therapy with VKA but are underdosed compared with the global average in the GARFIELD-AF. CLINICAL TRIAL REGISTRATION-URL: http://www.clinicaltrials.gov. Unique identifier: NCT01090362

Vanzacaftor–tezacaftor–deutivacaftor versus elexacaftor–tezacaftor–ivacaftor in individuals with cystic fibrosis aged 12 years and older (SKYLINE Trials VX20-121-102 and VX20-121-103): results from two randomised, active-controlled, phase 3 trials

Background The goal of cystic fibrosis transmembrane conductance regulator (CFTR) modulators is to reach normal CFTR function in people with cystic fibrosis. Vanzacaftor–tezacaftor–deutivacaftor restored CFTR function in vitro and in phase 2 trials in participants aged 18 years and older resulting in improvements in CFTR function, as measured by sweat chloride concentrations and lung function as measured by spirometry. We aimed to evaluate the efficacy and safety of vanzacaftor–tezacaftor–deutivacaftor compared with standard of care elexacaftor–tezacaftor–ivacaftor in individuals with cystic fibrosis aged 12 years and older. Methods In two randomised, active-controlled, double-blind, phase 3 trials, individuals aged 12 years and older with stable cystic fibrosis with F508del-minimal function (SKYLINE Trial VX20-121-102) or with F508del-F508del, F508del-residual function, F508del-gating, or elexacaftor–tezacaftor–ivacaftor-responsive-non-F508del genotypes (SKYLINE Trial VX20-121-103) were enrolled at 126 and 159 international sites, respectively. Eligible individuals were entered into a 4-week run-in period, during which they received elexacaftor (200 mg once daily), tezacaftor (100 mg once daily), and ivacaftor (150 mg once every 12 h) as two fixed-dose combination tablets in the morning and one ivacaftor tablet in the evening. They were then randomly assigned (1:1) to either elexacaftor (200 mg once daily), tezacaftor (100 mg once daily), and ivacaftor (150 mg once every 12 h) as two fixed-dose combination tablets in the morning and one ivacaftor tablet in the evening, or vanzacaftor (20 mg once daily), tezacaftor (100 mg once daily), and deutivacaftor (250 mg once daily) as two fixed-dose combination tablets in the morning, for the 52-week treatment period. All participants received matching placebo tablets to maintain the treatment blinding. Randomisation was done using an interactive web-response system and stratified by age, FEV1 % predicted, sweat chloride concentration, and previous CFTR modulator use, and also by genotype for Trial VX20-121-103. The primary endpoint for both trials was absolute change in FEV1 % predicted from baseline (most recent value before treatment on day 1) through week 24 (with non-inferiority of vanzacaftor–tezacaftor–deutivacaftor shown if the lower bound of the 95% CI for the primary endpoint was –3·0 or higher). Efficacy was assessed in all participants with the intended CFTR genotype who were randomly assigned to treatment and received at least one dose of study treatment during the treatment period. Safety was assessed in all participants who received at least one dose of study drug during the treatment period. These trials are registered with ClinicalTrials.gov, NCT05033080 (Trial VX20-121-102) and NCT05076149 (Trial VX20-121-103), and are now complete. Findings In Trial VX20-121-102 between Sept 14, 2021, and Oct 18, 2022, 488 individuals were screened, of whom 435 entered the 4-week run-in period, and subsequently 398 were randomly assigned and received at least one dose of elexacaftor–tezacaftor–ivacaftor (n=202) or vanzacaftor–tezacaftor–deutivacaftor (n=196). Median age was 31·0 years (IQR 22·6–38·5), 163 (41%) of 398 participants were female, 235 (59%) were male, and 388 (97%) were White. In Trial VX20-121-103, between Oct 27, 2021, and Oct 26, 2022, 699 individuals were screened, of whom 597 entered the 4-week run-in period, and subsequently 573 participants were randomly assigned and received at least one dose of elexacaftor–tezacaftor–ivacaftor (n=289) or vanzacaftor–tezacaftor–deutivacaftor (n=284). Median age was 33·1 years (IQR 24·5–42·2), 280 (49%) of 573 participants were female, 293 (51%) were male, and 532 (93%) were White. The absolute change in least squares mean FEV1 % predicted from baseline through week 24 for Trial VX20-121-102 was 0·5 (SE 0·3) percentage points in the vanzacaftor–tezacaftor–deutivacaftor group versus 0·3 (0·3) percentage points in the elexacaftor–tezacaftor–ivacaftor group (least squares mean treatment difference of 0·2 percentage points [95% CI –0·7 to 1·1]; p<0·0001), and for Trial VX20-121-103, was 0·2 (SE 0·3) percentage points in the vanzacaftor–tezacaftor–deutivacaftor group versus 0·0 (0·2) percentage points in the elexacaftor–tezacaftor–ivacaftor group (least squares mean treatment difference 0·2 percentage points [95% CI –0·5 to 0·9]; p<0·0001). Most adverse events were mild or moderate, with the most common being infective pulmonary exacerbation (133 [28%] of 480 participants in the pooled vanzacaftor–tezacaftor–deutivacaftor group vs 158 [32%] of 491 in the pooled elexacaftor–tezacaftor–ivacaftor group), cough (108 [23%] vs 101 [21%]), COVID-19 (107 [22%] vs 127 [26%]), and nasopharyngitis (102 [21%] vs 95 [19%]). Interpretation Vanzacaftor–tezacaftor–deutivacaftor is non-inferior to elexacaftor–tezacaftor–ivacaftor in terms of FEV1 % predicted, and is safe and well tolerated. Once daily dosing with vanzacaftor–tezacaftor–deutivacaftor reduces treatment burden, potentially improving adherence, compared with the twice daily regimen of the current standard of care. The restoration of CFTR function and the potential variants treated are also considerations that should be compared with currently available CFTR modulators. Funding Vertex Pharmaceuticals

Excess quantum noise due to nonorthogonal polarization modes

We show that the quantum-limited linewidth of a laser can be enhanced when the polarization eigenmodes of the laser resonator are nonorthogonal. For the theoretical description of this phenomenon we introduce a simple coupled two-mode model. Experimentally, we observed an enhancement of the quantum noise by a factor of 60 in a He-Xe gas laser