Modeling of Fluctuations in Dynamical Optoelectronic Device Simulations within a Maxwell-Density Matrix Langevin Approach

We present a full-wave Maxwell-density matrix simulation tool including c-number stochastic noise terms for the modeling of the spatiotemporal dynamics in active photonic devices, such as quantum cascade lasers (QCLs) and quantum dot (QD) structures. The coherent light-matter interaction in such devices plays an important role in the generation of frequency combs and other nonlinear and nonclassical optical phenomena. Since the emergence of nonlinear and nonclassical features is directly linked to the noise properties, detailed simulations of the noise characteristics are required for the development of low-noise quantum optoelectronic sources. Our semiclassical simulation framework is based on the Lindblad equation for the electron dynamics, coupled with Maxwell's equations for the optical propagation in the laser waveguide. Fluctuations arising from interactions of the optical field and quantum system with their reservoirs are treated within the quantum Langevin theory. Here, the fluctuations are included by adding stochastic c-number terms to the Maxwell-density matrix equations. The implementation in the mbsolve dynamic simulation framework is publicly available.Comment: 18 pages, 5 figure

Repeating adrenal vein sampling when neither aldosterone/cortisol ratio exceeds peripheral yields a high incidence of aldosterone-producing adenoma

Objectives:In primary aldosteronism, adrenal vein sampling (AVS) suggests unilateral aldosterone-producing adenoma (APA) when the aldosterone/cortisol (A/F) ratio is less than or equal to peripheral on one side and at least two times peripheral on the other. When A/F ratios are lower bilaterally than peripheral despite adequate samples (adrenal venous cortisol 3 times peripheral), we recommend repeat AVS. This study aimed to determine the frequency of this occurrence and outcomes in such cases.Methods:We performed a retrospective observational study of all cases of primary aldosteronism undergoing initial AVS over a 34-year period.Results:Initial AVS in 1397 patients returned satisfactory and discriminatory results in 1066 (76.3%) but 37 patients (2.6%) had adequate samples but bilateral A/F ratios no higher than peripheral. Of the 22 of these 37 who agreed to repeat AVS, 10 demonstrated unilateral aldosterone production, and eight of these had unilateral adrenalectomy disclosing APAs and resulting in cure (3) or improvement (5) in hypertension. Eight had bilateral aldosterone production. Four studies were inconclusive. Patients with initial unsatisfactory AVS because of bilaterally low A/F ratios had significantly (P=0.023) more unilateral disease [10 of 18 satisfactory repeat studies (55.6%) vs. 326 of 1066 satisfactory initial studies (30.6%)] and a significantly higher (67.6 vs. 49.9%, P=0.034) percentage of males.Conclusion:As the incidence of APAs was high in a subgroup with low A/F bilaterally on initial AVS, these patients should be offered repeat AVS. This might reflect both a greater dependence of aldosterone production on adrenocorticotrophic hormone (ACTH) in APAs and the pulsatile nature of ACTH secretion

Hyperdynamic right heart function in Graves' hyperthyroidism measured by echocardiography normalises on restoration of euthyroidism

Graves' hyperthyroidism commonly causes tachycardia and may result in pulmonary hypertension and high output cardiac failure. There is limited information regarding the effect of treatment on cardiac function measured using modern echocardiographic techniques.Eight individuals with Graves' hyperthyroidism, aged 22-64 years, underwent comprehensive transthoracic echocardiography at three time points: before treatment, two weeks after commencement of carbimazole, and at six months or more when euthyroid. Exercise capacity was assessed using the 6-minute-walk-distance (6MWT), and quality of life was assessed by Medical Outcome Study 36-item Short-Form Health Status Survey.All individuals were rendered euthyroid by final assessment. At presentation, there was evidence of hyperdynamic right ventricular function as measured by peak systolic velocity of the free wall of the tricuspid annulus, tricuspid annular plane systolic excursion and right ventricular ejection fraction, which normalised after resolution of thyrotoxicosis. Baseline heart rate correlated significantly with severity of the thyrotoxicosis for either free T4 (r = 0.91, p=0.01) or free T3 (r=0.94, p=0.001). No individual had measurable pulmonary hypertension. Cardiac output was significantly lower in the euthyroid compared to the thyrotoxic state (p=0.03). A higher baseline TSH-receptor antibody titre corresponded to a greater improvement in exercise capacity (r=0.76,

The Management of Primary Aldosteronism: Case Detection, Diagnosis, and Treatment: An Endocrine Society Clinical Practice Guideline.

Abstract Objective: To develop clinical practice guidelines for the management of patients with primary aldosteronism. Participants: The Task Force included a chair, selected by the Clinical Guidelines Subcommittee of the Endocrine Society, six additional experts, a methodologist, and a medical writer. The guideline was cosponsored by American Heart Association, American Association of Endocrine Surgeons, European Society of Endocrinology, European Society of Hypertension, International Association of Endocrine Surgeons, International Society of Endocrinology, International Society of Hypertension, Japan Endocrine Society, and The Japanese Society of Hypertension. The Task Force received no corporate funding or remuneration. Evidence: We searched for systematic reviews and primary studies to formulate the key treatment and prevention recommendations. We used the Grading of Recommendations, Assessment, Development, and Evaluation group criteria to describe both the quality of evidence and the strength of recommendations. We used "recommend" for strong recommendations and "suggest" for weak recommendations. Consensus Process: We achieved consensus by collecting the best available evidence and conducting one group meeting, several conference calls, and multiple e-mail communications. With the help of a medical writer, the Endocrine Society's Clinical Guidelines Subcommittee, Clinical Affairs Core Committee, and Council successfully reviewed the drafts prepared by the Task Force. We placed the version approved by the Clinical Guidelines Subcommittee and Clinical Affairs Core Committee on the Endocrine Society's website for comments by members. At each stage of review, the Task Force received written comments and incorporated necessary changes. Conclusions: For high-risk groups of hypertensive patients and those with hypokalemia, we recommend case detection of primary aldosteronism by determining the aldosterone-renin ratio under standard conditions and recommend that a commonly used confirmatory test should confirm/exclude the condition. We recommend that all patients with primary aldosteronism undergo adrenal computed tomography as the initial study in subtype testing and to exclude adrenocortical carcinoma. We recommend that an experienced radiologist should establish/exclude unilateral primary aldosteronism using bilateral adrenal venous sampling, and if confirmed, this should optimally be treated by laparoscopic adrenalectomy. We recommend that patients with bilateral adrenal hyperplasia or those unsuitable for surgery should be treated primarily with a mineralocorticoid receptor antagonist

A systematic review and meta-analysis of thiazide-induced hyponatraemia: time to reconsider electrolyte monitoring regimens after thiazide initiation?

Aims: Hyponatraemia is one of the major adverse effects of thiazide and thiazide-like diuretics and the leading cause of drug-induced hyponatraemia requiring hospital admission. We sought to review and analyze all published cases of this important condition. Methods: Ovid Medline, Embase, Web of Science and PubMed electronic databases were searched to identify all relevant articles published before October 2013. A proportions meta-analysis was undertaken. Results: One hundred and two articles were identified of which 49 were single patient case reports. Meta-analysis showed that mean age was 75 (95% CI 73, 77) years, 79% were women (95% CI 74, 82) and mean body mass index was 25 (95% CI 20, 30) kg m−2. Presentation with thiazide-induced hyponatraemia occurred a mean of 19 (95% CI 8, 30) days after starting treatment, with mean trough serum sodium concentration of 116 (95% CI 113, 120) mm and serum potassium of 3.3 (95% CI 3.0, 3.5) mm. Mean urinary sodium concentration was 64 mm (95% CI 47, 81). The most frequently reported drugs were hydrochlorothiazide, indapamide and bendroflumethiazide. Conclusions: Patients with thiazide-induced hyponatraemia were characterized by advanced age, female gender, inappropriate saliuresis and mild hypokalaemia. Low BMI was not found to be a significant risk factor, despite previous suggestions. The time from thiazide initiation to presentation with hyponatraemia suggests that the recommended practice of performing a single investigation of serum biochemistry 7–14 days after thiazide initiation may be insufficient or suboptimal. Further larger and more systematic studies of thiazide-induced hyponatraemia are required

A systematic review and meta-analysis of thiazide-induced hyponatraemia: time to reconsider electrolyte monitoring regimens after thiazide initiation?

Aims: Hyponatraemia is one of the major adverse effects of thiazide and thiazide-like diuretics and the leading cause of drug-induced hyponatraemia requiring hospital admission. We sought to review and analyze all published cases of this important condition. Methods: Ovid Medline, Embase, Web of Science and PubMed electronic databases were searched to identify all relevant articles published before October 2013. A proportions meta-analysis was undertaken. Results: One hundred and two articles were identified of which 49 were single patient case reports. Meta-analysis showed that mean age was 75 (95% CI 73, 77) years, 79% were women (95% CI 74, 82) and mean body mass index was 25 (95% CI 20, 30) kg m−2. Presentation with thiazide-induced hyponatraemia occurred a mean of 19 (95% CI 8, 30) days after starting treatment, with mean trough serum sodium concentration of 116 (95% CI 113, 120) mm and serum potassium of 3.3 (95% CI 3.0, 3.5) mm. Mean urinary sodium concentration was 64 mm (95% CI 47, 81). The most frequently reported drugs were hydrochlorothiazide, indapamide and bendroflumethiazide. Conclusions: Patients with thiazide-induced hyponatraemia were characterized by advanced age, female gender, inappropriate saliuresis and mild hypokalaemia. Low BMI was not found to be a significant risk factor, despite previous suggestions. The time from thiazide initiation to presentation with hyponatraemia suggests that the recommended practice of performing a single investigation of serum biochemistry 7–14 days after thiazide initiation may be insufficient or suboptimal. Further larger and more systematic studies of thiazide-induced hyponatraemia are required

Synthese und Eigenschaften von 1,3,5,7-Tetra-tert-butyl-s-indacen

Um den Substituenteneinfluß auf den Bindungszustand des 12π-Perimeters von s-Indacen zu prüfen, wurde ein Tetraalkylderivat, die Titelverbindung 1, synthetisiert. 1, rote Nadeln, ist schwach paratrop. Kristallstrukturanalyse und NMR-Untersuchungen weisen auf ein delokalisiertes oder ein lokalisiertes π-Elektronensystem mit nur kleiner Energiebarriere zwischen den π-Bindungsisomeren hin