Laser operation of a Tm:Y₂O₃ planar waveguide

We demonstrate the first Tm-doped yttria planar waveguide laser to our knowledge, grown by pulsed laser deposition. A maximum output power of 35 mW at 1.95 µm with 9% slope efficiency was achieved from a 12 µm-thick film grown on a Y3Al5O12 substrate

An 11.5 W Yb:YAG planar waveguide laser fabricated via pulsed laser deposition

We present details of the homo-epitaxial growth of Yb:YAG onto a <100> oriented YAG substrate by pulsed laser deposition. Material characterization and initial laser experiments are also reported, including the demonstration of laser action from the 15 µm-thick planar waveguide generating 11.5 W of output power with a slope efficiency of 48%. This work indicates that under appropriate conditions, high-quality single-crystal Yb:YAG growth via pulsed laser deposition is achievable with characteristics comparable to those obtained via conventional crystal growth techniques

Commensurate and incommensurate 1D interacting quantum systems

Single-atom imaging resolution of many-body quantum systems in optical lattices is routinely achieved with quantum-gas microscopes. Key to their great versatility as quantum simulators is the ability to use engineered light potentials at the microscopic level. Here, we employ dynamically varying microscopic light potentials in a quantum-gas microscope to study commensurate and incommensurate 1D systems of interacting bosonic Rb atoms. Such incommensurate systems are analogous to doped insulating states that exhibit atom transport and compressibility. Initially, a commensurate system with unit filling and fixed atom number is prepared between two potential barriers. We deterministically create an incommensurate system by dynamically changing the position of the barriers such that the number of available lattice sites is reduced while retaining the atom number. Our systems are characterised by measuring the distribution of particles and holes as a function of the lattice filling, and interaction strength, and we probe the particle mobility by applying a bias potential. Our work provides the foundation for preparation of low-entropy states with controlled filling in optical-lattice experiments.Comment: 12 pages, 10 figure

Theory of Distinct Crystal Structures of Polymerized Fullerides AC60, A=K, Rb, Cs: the Specific Role of Alkalis

The polymer phases of AC60 form distinct crystal structures characterized by the mutual orientations of the (C60-)n chains. We show that the direct electric quadrupole interaction between chains always favors the orthorhombic structure Pmnn with alternating chain orientations. However the specific quadrupolar polarizability of the alkali metal ions leads to an indirect interchain coupling which favors the monoclinic structure I2/m with equal chain orientations. The competition between direct and indirect interactions explains the structural difference between KC60 and RbC60, CsC60.Comment: 4 pages, 2 figures, 1 tabl

Lower Bounds and Series for the Ground State Entropy of the Potts Antiferromagnet on Archimedean Lattices and their Duals

We prove a general rigorous lower bound for $W(\Lambda,q)=\exp(S_0(\Lambda,q)/k_B)$, the exponent of the ground state entropy of the $q$-state Potts antiferromagnet, on an arbitrary Archimedean lattice $\Lambda$. We calculate large-$q$ series expansions for the exact $W_r(\Lambda,q)=q^{-1}W(\Lambda,q)$ and compare these with our lower bounds on this function on the various Archimedean lattices. It is shown that the lower bounds coincide with a number of terms in the large-$q$ expansions and hence serve not just as bounds but also as very good approximations to the respective exact functions $W_r(\Lambda,q)$ for large $q$ on the various lattices $\Lambda$. Plots of $W_r(\Lambda,q)$ are given, and the general dependence on lattice coordination number is noted. Lower bounds and series are also presented for the duals of Archimedean lattices. As part of the study, the chromatic number is determined for all Archimedean lattices and their duals. Finally, we report calculations of chromatic zeros for several lattices; these provide further support for our earlier conjecture that a sufficient condition for $W_r(\Lambda,q)$ to be analytic at $1/q=0$ is that $\Lambda$ is a regular lattice.Comment: 39 pages, Revtex, 9 encapsulated postscript figures, to appear in Phys. Rev.

Perinatal outcomes after in-utero exposure to beta-blockers in women with heart disease:Data from the ESC EORP registry of pregnancy and cardiac disease (ROPAC)

Background: Beta-blockers are commonly used drugs during pregnancy, especially in women with heart disease, and are regarded as relatively safe although evidence is sparse. Differences between beta-blockers are not well-studied. Methods: In the Registry of Pregnancy And Cardiac disease (ROPAC, n = 5739), a prospective global registry of pregnancies in women with structural heart disease, perinatal outcomes (small for gestational age (SGA), birth weight, neonatal congenital heart disease (nCHD) and perinatal mortality) were compared between women with and without beta-blocker exposure, and between different beta-blockers. Multivariable regression analysis was used for the effect of beta-blockers on birth weight, SGA and nCHD (after adjustment for maternal and perinatal confounders). Results: Beta-blockers were used in 875 (15.2%) ROPAC pregnancies, with metoprolol (n = 323, 37%) and bisoprolol (n = 261, 30%) being the most frequent. Women with beta-blocker exposure had more SGA infants (15.3% vs 9.3%, p &lt; 0.001) and nCHD (4.7% vs 2.7%, p = 0.001). Perinatal mortality rates were not different (1.4% vs 1.9%, p = 0.272). The adjusted mean difference in birth weight was −177 g (−5.8%), the adjusted OR for SGA was 1.7 (95% CI 1.3–2.1) and for nCHD 2.3 (1.6–3.5). With metoprolol as reference, labetalol (0.2, 0.1–0.4) was the least likely to cause SGA, and atenolol (2.3, 1.1–4.9) the most. Conclusions: In women with heart disease an association was found between maternal beta-blocker use and perinatal outcomes. Labetalol seems to be associated with the lowest risk of developing SGA, while atenolol should be avoided.</p

Pregnancy outcomes in women with cardiovascular disease: evolving trends over 10 years in the ESC Registry Of Pregnancy And Cardiac disease (ROPAC)

Aims Reducing maternal mortality is a World Health Organization (WHO) global health goal. Although maternal deaths due to haemorrhage and infection are declining, those related to heart disease are increasing and are now the most important cause in western countries. The aim is to define contemporary diagnosis-specific outcomes in pregnant women with heart disease. Methods and results From 2007 to 2018, pregnant women with heart disease were prospectively enrolled in the Registry Of Pregnancy And Cardiac disease (ROPAC). Primary outcome was maternal mortality or heart failure, secondary outcomes were other cardiac, obstetric, and foetal complications. We enrolled 5739 pregnancies; the mean age was 29.5. Prevalent diagnoses were congenital (57%) and valvular heart disease (29%). Mortality (overall 0.6%) was highest in the pulmonary arterial hypertension (PAH) group (9%). Heart failure occurred in 11%, arrhythmias in 2%. Delivery was by Caesarean section in 44%. Obstetric and foetal complications occurred in 17% and 21%, respectively. The number of high-risk pregnancies (mWHO Class IV) increased from 0.7% in 2007–2010 to 10.9% in 2015–2018. Determinants for maternal complications were pre-pregnancy heart failure or New York Heart Association >II, systemic ejection fraction <40%, mWHO Class 4, and anticoagulants use. After an increase from 2007 to 2009, complication rates fell from 13.2% in 2010 to 9.3% in 2017. Conclusion Rates of maternal mortality or heart failure were high in women with heart disease. However, from 2010, these rates declined despite the inclusion of more high-risk pregnancies. Highest complication rates occurred in women with PAH

Perinatal outcomes after in-utero exposure to beta-blockers in women with heart disease:Data from the ESC EORP registry of pregnancy and cardiac disease (ROPAC)

Background: Beta-blockers are commonly used drugs during pregnancy, especially in women with heart disease, and are regarded as relatively safe although evidence is sparse. Differences between beta-blockers are not well-studied. Methods: In the Registry of Pregnancy And Cardiac disease (ROPAC, n = 5739), a prospective global registry of pregnancies in women with structural heart disease, perinatal outcomes (small for gestational age (SGA), birth weight, neonatal congenital heart disease (nCHD) and perinatal mortality) were compared between women with and without beta-blocker exposure, and between different beta-blockers. Multivariable regression analysis was used for the effect of beta-blockers on birth weight, SGA and nCHD (after adjustment for maternal and perinatal confounders). Results: Beta-blockers were used in 875 (15.2%) ROPAC pregnancies, with metoprolol (n = 323, 37%) and bisoprolol (n = 261, 30%) being the most frequent. Women with beta-blocker exposure had more SGA infants (15.3% vs 9.3%, p &lt; 0.001) and nCHD (4.7% vs 2.7%, p = 0.001). Perinatal mortality rates were not different (1.4% vs 1.9%, p = 0.272). The adjusted mean difference in birth weight was −177 g (−5.8%), the adjusted OR for SGA was 1.7 (95% CI 1.3–2.1) and for nCHD 2.3 (1.6–3.5). With metoprolol as reference, labetalol (0.2, 0.1–0.4) was the least likely to cause SGA, and atenolol (2.3, 1.1–4.9) the most. Conclusions: In women with heart disease an association was found between maternal beta-blocker use and perinatal outcomes. Labetalol seems to be associated with the lowest risk of developing SGA, while atenolol should be avoided.</p

2-Hour Accelerated Diagnostic Protocol to Assess Patients With Chest Pain Symptoms Using Contemporary Troponins as the Only Biomarker

Objectives The purpose of this study was to determine whether a new accelerated diagnostic protocol (ADP) for possible cardiac chest pain could identify low-risk patients suitable for early discharge (with follow-up shortly after discharge). Background Patients presenting with possible acute coronary syndrome (ACS), who have a low short-term risk of adverse cardiac events may be suitable for early discharge and shorter hospital stays. Methods This prospective observational study tested an ADP that included pre-test probability scoring by the Thrombolysis In Myocardial Infarction (TIMI) score, electrocardiography, and 0 + 2 h values of laboratory troponin I as the sole biomarker. Patients presenting with chest pain due to suspected ACS were included. The primary endpoint was major adverse cardiac event (MACE) within 30 days. Results Of 1,975 patients, 302 (15.3%) had a MACE. The ADP classified 392 patients (20%) as low risk. One (0.25%) of these patients had a MACE, giving the ADP a sensitivity of 99.7% (95% confidence interval [CI]: 98.1% to 99.9%), negative predictive value of 99.7% (95% CI: 98.6% to 100.0%), specificity of 23.4% (95% CI: 21.4% to 25.4%), and positive predictive value of 19.0% (95% CI: 17.2% to 21.0%). Many ADP negative patients had further investigations (74.1%), and therapeutic (18.3%) or procedural (2.0%) interventions during the initial hospital attendance and/or 30-day follow-up. Conclusions Using the ADP, a large group of patients was successfully identified as at low short-term risk of a MACE and therefore suitable for rapid discharge from the emergency department with early follow-up. This approach could decrease the observation period required for some patients with chest pain. (An observational study of the diagnostic utility of an accelerated diagnostic protocol using contemporary central laboratory cardiac troponin in the assessment of patients presenting to two Australasian hospitals with chest pain of possible cardiac origin; ACTRN12611001069943

Cost-Effectiveness of Highly Active Antiretroviral Therapy in South Africa

BACKGROUND: Little information exists on the impact of highly active antiretroviral therapy (HAART) on health-care provision in South Africa despite increasing scale-up of access to HAART and gradual reduction in HAART prices. METHODS AND FINDINGS: Use and cost of services for 265 HIV-infected adults without AIDS (World Health Organization [WHO] stage 1, 2, or 3) and 27 with AIDS (WHO stage 4) receiving HAART between 1995 and 2000 in Cape Town were compared with HIV-infected controls matched for baseline WHO stage, CD4 count, age, and socioeconomic status, who did not receive antiretroviral therapy (ART; No-ART group). Costs of service provision (January 2004 prices, US$1 = 7.6 Rand) included local unit costs, and two scenarios for HAART prices for WHO recommended first-line regimens: scenario 1 used current South African public-sector ART drug prices of$730 per patient-year (PPY), whereas scenario 2 was based on the anticipated public-sector price for locally manufactured drug of $181 PPY. All analyses are presented in terms of patients without AIDS and patients with AIDS. For patients without AIDS, the mean number of inpatient days PPY was 1.08 (95$950 for the No-ART group versus $1,342 and$793 PPY for the HAART group for scenario 1 and 2, respectively, whereas the incremental cost per life-year gained (LYG) was $1,622 for scenario 1 and$675 for scenario 2. For patients with AIDS, mean inpatients days PPY was 2.04 (95% CI: 1.63–2.52) for the HAART versus 15.36 (95% CI: 13.97–16.85) for the No-ART group. Mean outpatient visits PPY was 7.62 (95% CI: 6.81–8.49) compared with 6.60 (95% CI: 5.69–7.62) respectively. Average service provision PPY was $3,520 for the No-ART group versus$1,513 and $964 for the HAART group for scenario 1 and 2, respectively, whereas the incremental cost per LYG was cost saving for both scenarios. In a sensitivity analysis based on the lower (25$1,557 to $1,772 for the group without AIDS and from cost saving to$111 for patients with AIDS. CONCLUSION: HAART is a cost-effective intervention in South Africa, and cost saving when HAART prices are further reduced. Our estimates, however, were based on direct costs, and as such the actual cost saving might have been underestimated if indirect costs were also included