| 1. |
- Ademuyiwa, Adesoji O., et al.
(författare)
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Determinants of morbidity and mortality following emergency abdominal surgery in children in low-income and middle-income countries
- 2016
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Ingår i: BMJ Global Health. - : BMJ Publishing Group Ltd. - 2059-7908. ; 1:4
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Tidskriftsartikel (refereegranskat)abstract
- Background: Child health is a key priority on the global health agenda, yet the provision of essential and emergency surgery in children is patchy in resource-poor regions. This study was aimed to determine the mortality risk for emergency abdominal paediatric surgery in low-income countries globally.Methods: Multicentre, international, prospective, cohort study. Self-selected surgical units performing emergency abdominal surgery submitted prespecified data for consecutive children aged <16 years during a 2-week period between July and December 2014. The United Nation's Human Development Index (HDI) was used to stratify countries. The main outcome measure was 30-day postoperative mortality, analysed by multilevel logistic regression.Results: This study included 1409 patients from 253 centres in 43 countries; 282 children were under 2 years of age. Among them, 265 (18.8%) were from low-HDI, 450 (31.9%) from middle-HDI and 694 (49.3%) from high-HDI countries. The most common operations performed were appendectomy, small bowel resection, pyloromyotomy and correction of intussusception. After adjustment for patient and hospital risk factors, child mortality at 30 days was significantly higher in low-HDI (adjusted OR 7.14 (95% CI 2.52 to 20.23), p<0.001) and middle-HDI (4.42 (1.44 to 13.56), p=0.009) countries compared with high-HDI countries, translating to 40 excess deaths per 1000 procedures performed.Conclusions: Adjusted mortality in children following emergency abdominal surgery may be as high as 7 times greater in low-HDI and middle-HDI countries compared with high-HDI countries. Effective provision of emergency essential surgery should be a key priority for global child health agendas.
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| 2. |
- Ciers, Anastasiia, 1992, et al.
(författare)
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Integrated free-space optomechanics with AlGaAs heterostructures
- 2021
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Ingår i: 2021 Conference on Lasers and Electro-Optics Europe and European Quantum Electronics Conference, CLEO/Europe-EQEC 2021. - 9781557528209
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Konferensbidrag (refereegranskat)abstract
- We fabricated and characterized suspended bi-layered photonic crystal slabs in AlGaAs heterostructures. Our approach allows to create integrated, closely spaced membranes, which can exhibit photonic bound states in the continuum to increase light-matter interaction.
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| 3. |
- Coelho, Teresa, et al.
(författare)
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Safety and efficacy of RNAi therapy for transthyretin amyloidosis
- 2013
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Ingår i: The New England journal of medicine. - 1533-4406. ; 369:9, s. 819-29
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Transthyretin amyloidosis is caused by the deposition of hepatocyte-derived transthyretin amyloid in peripheral nerves and the heart. A therapeutic approach mediated by RNA interference (RNAi) could reduce the production of transthyretin. METHODS: We identified a potent antitransthyretin small interfering RNA, which was encapsulated in two distinct first- and second-generation formulations of lipid nanoparticles, generating ALN-TTR01 and ALN-TTR02, respectively. Each formulation was studied in a single-dose, placebo-controlled phase 1 trial to assess safety and effect on transthyretin levels. We first evaluated ALN-TTR01 (at doses of 0.01 to 1.0 mg per kilogram of body weight) in 32 patients with transthyretin amyloidosis and then evaluated ALN-TTR02 (at doses of 0.01 to 0.5 mg per kilogram) in 17 healthy volunteers. RESULTS: Rapid, dose-dependent, and durable lowering of transthyretin levels was observed in the two trials. At a dose of 1.0 mg per kilogram, ALN-TTR01 suppressed transthyretin, with a mean reduction at day 7 of 38%, as compared with placebo (P=0.01); levels of mutant and nonmutant forms of transthyretin were lowered to a similar extent. For ALN-TTR02, the mean reductions in transthyretin levels at doses of 0.15 to 0.3 mg per kilogram ranged from 82.3 to 86.8%, with reductions of 56.6 to 67.1% at 28 days (P<0.001 for all comparisons). These reductions were shown to be RNAi-mediated. Mild-to-moderate infusion-related reactions occurred in 20.8% and 7.7% of participants receiving ALN-TTR01 and ALN-TTR02, respectively. CONCLUSIONS: ALN-TTR01 and ALN-TTR02 suppressed the production of both mutant and nonmutant forms of transthyretin, establishing proof of concept for RNAi therapy targeting messenger RNA transcribed from a disease-causing gene. (Funded by Alnylam Pharmaceuticals; ClinicalTrials.gov numbers, NCT01148953 and NCT01559077.).
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| 4. |
- de Amorim Ferreira, Beatriz, 1996, et al.
(författare)
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Revealing Dark Exciton Signatures in Polariton Spectra of 2D Materials
- 2024
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Ingår i: ACS Photonics. - 2330-4022. ; In Press
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Tidskriftsartikel (refereegranskat)abstract
- Dark excitons in transition metal dichalcogenides (TMDs) have been so far neglected in the context of polariton physics due to their lack of oscillator strength. However, in tungsten-based TMDs, dark excitons are known to be the energetically lowest states and could thus provide important scattering partners for polaritons. In this joint theoretical-experimental work, we investigate the impact of the full exciton energy landscape on polariton absorption and reflectance. By changing the cavity detuning, we vary the polariton energy relative to the unaffected dark excitons in such a way that we open or close specific phonon-driven scattering channels. We demonstrate both in theory and experiment that this controlled switching of scattering channels manifests in characteristic sharp changes in the optical spectra of polaritons. These spectral features can be exploited to extract the position of dark excitons. Our work suggests new possibilities for exploiting polaritons for fingerprinting nanomaterials via their unique exciton landscape.
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| 5. |
- Ferreira, Beatriz, 1996, et al.
(författare)
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Signatures of dark excitons in exciton–polariton optics of transition metal dichalcogenides
- 2023
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Ingår i: 2D Materials. - : IOP Publishing. - 2053-1583. ; 10
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Tidskriftsartikel (refereegranskat)abstract
- Integrating 2D materials into high-quality optical microcavities opens the door to fascinating many-particle phenomena including the formation of exciton-polaritons. These are hybrid quasi-particles inheriting properties of both the constituent photons and excitons. In this work, we investigate the so-far overlooked impact of dark excitons on the momentum-resolved absorption spectra of hBN-encapsulated WSe2 and MoSe2 monolayers in the strong-coupling regime. In particular, thanks to the efficient phonon-mediated scattering of polaritons into energetically lower dark exciton states, the absorption of the lower polariton branch in WSe2 is much higher than in MoSe2. It shows unique step-like increases in the momentum-resolved profile indicating opening of specific scattering channels. We study how different externally accessible quantities, such as temperature or mirror reflectance, change the optical response of polaritons. Our study contributes to an improved microscopic understanding of exciton-polaritons and their interaction with phonons, potentially suggesting experiments that could determine the energy of dark exciton states via momentum-resolved polariton absorption.
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| 6. |
- Fitzgerald, Jamie, 1992, et al.
(författare)
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Cavity optomechanics with photonic bound states in the continuum
- 2021
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Ingår i: Physical Review Research. - 2643-1564. ; 3:1
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Tidskriftsartikel (refereegranskat)abstract
- We propose a versatile, free-space cavity optomechanics platform built from two photonic crystal membranes, one of which is freely suspended, and designed to form a microcavity less than one wavelength long. This cavity features a series of photonic bound states in the continuum that, in principle, trap light forever and can be favorably used together with evanescent coupling for realizing various types of optomechanical couplings, such as linear or quadratic coupling of either dispersive or dissipative type, by tuning the photonic crystal patterning and cavity length. Crucially, this platform allows for a quantum cooperativity exceeding unity in the ultrastrong single-photon coupling regime, surpassing the performance of conventional Fabry-Perot-based cavity optomechanical devices in the nonresolved sideband regime. This platform allows for exploring new regimes of the optomechanical interaction, in particular in the framework of pulsed and single-photon optomechanics.
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| 7. |
- Fitzgerald, Jamie, 1992, et al.
(författare)
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Nanophotonic Structures for Cavity Optomechanics
- 2021
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Ingår i: 2021 Conference on Lasers and Electro-Optics Europe and European Quantum Electronics Conference, CLEO/Europe-EQEC 2021. ; June 2021
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Konferensbidrag (refereegranskat)abstract
- In this contribution, we will show how nanophotonic structures can be used to gain access to previously inaccessible regimes in cavity optomechanics [1]. We introduce a novel optomechanics platform, built from two photonic crystal membranes [2] , one of which is freely suspended (see Fig. 1 ). This cavity supports a series of photonic bound states in the continuum (BICs) that, in principle, trap light forever [3] and can be favourably used together with evanescent coupling for realizing various types of optomechanical couplings, such as linear or quadratic coupling of either dispersive or dissipative type, by tuning the photonic crystal patterning and cavity length. By combining light propagation in both free-space (between the photonic-crystal membranes) and guided-mode (over the photonic-crystal membranes) form, our platform merges the strengths offered by in-plane and out-of-plane optomechanical systems.
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| 8. |
- Fitzgerald, Jamie, 1992, et al.
(författare)
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Surface phonon polaritonics made simple: Great as plasmonics but lower losses
- 2019
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Ingår i: Advanced Photonics. - 2577-5421. ; 1:2
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Phonon-polaritons offer an exciting avenue in nanophotonics. We comment on the novel nanofabrication approach presented by Bo Qiang et al. in this issue of Advanced Photonics. Their approach to phononic material allows better radiation manipulation, and high Q-factors.
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| 9. |
- Fitzgerald, Jamie, et al.
(författare)
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The N-terminal N5 subdomain of the alpha 3(VI) chain is important for collagen VI microfibril formation
- 2001
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Ingår i: Journal of Biological Chemistry. - 1083-351X. ; 276:1, s. 187-193
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Tidskriftsartikel (refereegranskat)abstract
- Collagen VI assembly is unique within the collagen superfamily in that the alpha 1(VI), alpha 2(VI), and alpha 3(VI) chains associate intracellularly to form triple helical monomers, and then dimers and tetramers, which are secreted from the cell. Secreted tetramers associate end-to-end to form the distinctive extracellular microfibrils that are found in virtually all connective tissues. Although the precise protein interactions involved in this process are unknown, the N-terminal globular regions, which are composed of multiple copies of von Willebrand factor type A-like domains, are likely to play a critical role in microfibril formation, because they are exposed at both ends of the tetramers. To explore the role of these subdomains in collagen VI intracellular and extracellular assembly, alpha 3(VI) cDNA expression constructs with sequential N-terminal deletions were stably transfected into SaOS-2 cells, producing cell lines that express alpha 3(VI) chains with N-terminal globular domains containing modules N9-N1, N6-N1, N5-N1, N4-N1, N3-N1, or N1, as well as the complete triple helix and C-terminal globular domain (C1-C5). All of these transfected alpha 3(VI) chains were able to associate with endogenous alpha 1(VI) and alpha 2(VI) to form collagen VI monomers, dimers, and tetramers, which were secreted. Importantly, cells that expressed alpha 3(VI) chains containing the N5 subdomain, alpha 3(VI) N9-C5, N6-C5, and N5-C5, formed microfibrils and deposited a collagen VI matrix. In contrast, cells that expressed the shorter alpha 3(VI) chains, N4-C5, N3-C5, and N1-C5, were severely compromised in their ability to form end-to-end tetramer assemblies and failed to deposit a collagen VI matrix. These data demonstrate that the alpha 3(VI) N5 module is critical for microfibril formation, thus identifying a functional role for a specific type A subdomain in collagen VI assembly.
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| 10. |
- Fitzgerald, Jamie, 1992, et al.
(författare)
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Towards New Regimes in Cavity Optomechanics with Photonic Bound States in the Continuum in Photonic Crystal Membranes
- 2022
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Ingår i: International Conference on Metamaterials, Photonic Crystals and Plasmonics. - 2429-1390. ; , s. 633-634
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Konferensbidrag (refereegranskat)abstract
- We will present an optomechanics platform based on photonic bound states in the continuum and show that this platform is very flexible and makes it possible to reach different regimes of cavity optomechanics, e.g., with linear or quadratic coupling of either dispersive or dissipative type. Bound states in the continuum enable to build compact optomechanical devices, resulting in linear optomechanical coupling strengths that are orders of magnitude larger than conventional out-of-plane systems and comparable to values observed for in-plane geometries.
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