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Introduction Current guidelines recommend adding an oral antihyperglycemic agent (AHA) to metformin in patients with type 2 diabetes mellitus (T2DM) uncontrolled on metformin. Recent randomized clinical trials (RCTs) have demonstrated that adding dual AHAs instead of a single AHA provided more effective glycemic control. However, the comparative efficacy of approved single and dual initiation strategies is unknown. Therefore, we conducted a Bayesian network meta-analysis to compare the efficacy of dual and single add-on oral AHAs in patients uncontrolled on metformin. Methods A systematic literature review of RCTs was conducted following Cochrane and ISPOR guidelines. MEDLINE, Embase, and CENTRAL were searched from inception to November 19, 2019. Approved oral doses of sodium–glucose co-transporter-2 (SGLT-2) inhibitors, dipeptidyl peptidase-4 (DPP-4) inhibitors, and glucagon-like peptide-1 (GLP-1) receptor agonists in single or dual initiation therapies were indirectly compared. Outcomes focused on efficacy and included mean change from baseline in hemoglobin A1c (HbA1c), weight, systolic blood pressure (SBP), diastolic blood pressure, and achieving HbA1c target

Three-dimensional structure fabrication using discrete building blocks provides a versatile pathway for the creation of complex nanophotonic devices. The processing of individual components can generally support high-resolution, multiple-material, and variegated structures that are not achievable in a single step using top-down or hybrid methods. In addition, these methods are additive in nature, using minimal reagent quantities and producing little to no material waste. In this article, we review the most promising technologies that build structures using the placement of discrete components, focusing on laser-induced transfer, light-directed assembly, and inkjet printing. We discuss the underlying principles and most recent advances for each technique, as well as existing and future applications. These methods serve as adaptable platforms for the next generation of functional three-dimensional nanophotonic structures.

Rapid detection of toxic and hazardous gases at trace concentrations plays a vital role in industrial, battlefield, and laboratory scenarios. Of interest are both sensitive as well as highly selective sensors. Whispering gallery mode (WGM) microresonator-based biochemical sensors are among the most sensitive sensors in existence due to their long photon confinement times. One main concern with these devices, however, is their selectivity towards specific classes of target analytes. Here, we employ frequency locked whispering gallery mode microtoroid optical resonators covalently modified with various polymer coatings to selectively detect the chemical warfare agent surrogate diisopropyl methylphosphonate (DIMP) as well as the toxic industrial chemicals formaldehyde and ammonia at parts-per-trillion concentrations. This is 1-2 orders of magnitude better than previously reported, depending on the target, except for pristine graphene and pristine carbon nanotube sensors, which demonstrate similar detection levels but in vacuum and without selectivity. Selective polymer coatings include polyethylene glycol (PEG) for DIMP sensing, accessed by the modification of commercially available materials, and 3-(triethoxysilyl)propyl-terminated polyvinyl acetate (PVAc) for ammonia sensing. Notably, we developed an efficient one-pot procedure to access 3-(triethoxysilyl)propyl-terminated PVAc that utilizes cobalt-mediated living radical polymerization and a nitroxyl polymer-terminating agent. Alkaline hydrolysis of PVAc coatings to form polyvinyl alcohol (PVA) coatings directly bound to the microtoroid proved to be reliable and reproducible, leading to WGM sensors capable of the rapid and selective detection of formaldehyde vapors. The selectivity of these three polymer coatings as sensing media was predicted, in part, based on their functional group content and known reactivity patterns with the target analytes. Furthermore, we demonstrate that microtoroids coated with a mixture of polymers can serve as an all-in-one sensor that can detect multiple agents. We anticipate that our results will facilitate rapid early detection of chemical agents, as well as their surrogates and precursors.

Aims While glycemic control is key in effective type 2 diabetes mellitus management, many patients fail to reach their individualized glycemic goal. This analysis aimed to describe a real-world picture of diabetes management: individualized hemoglobin A1c (HbA1c) goals, rate of goal attainment, HbA1c at each line of therapy, and patient awareness of their glycemic goal. Secondly, we aimed to understand physician satisfaction with HbA1c amongst patients aware vs. those unaware of HbA1c goal. Methods Analysis of physicians and the next ten consulting patients with type 2 diabetes mellitus conducted in Europe and the USA including medical record data abstraction/assessment by physicians, a patient-reported survey and a physician survey. Patients were diagnosed for 3 months or more with a known current and target HbA1c. For the sub-analysis assessment of patient awareness of HbA1c goal, in addition to the above, these patients had to have completed a patient-reported questionnaire and answer the question on awareness of HbA1c goal. Results A total of 730 physicians provided data on 8794 patients with type 2 diabetes mellitus; 5331 patients were eligible for this analysis. Overall, mean (standard deviation, SD) individualized HbA1c goal was 6.8% (0.68%). Of eligible patients, 39.1% met their HbA1c goal; of 60.9% of patients not reaching their HbA1c goal, the mean distance from individualized HbA1c goal was 0.9% (SD 1.0%). Physicians progressed patients’ antihyperglycemic therapy when HbA1c was 8% or higher. Among 2560 patients who were included in the sub-analysis assessing the effect of patient awareness of their HbA1c goal on multiple parameters, 70.5% were aware of their HbA1c goal; mean HbA1c goal was 6.8% (0.7%) and current mean HbA1c value 7.1% (1.2%). A total of 949 patients in the sub-analysis (39.2%) achieved their goal; achieving HbA1c goal was not related to knowledge of goal. Patients aware of their HbA1c goal were slightly more adherent to their antihyperglycemic medication. They also were prescribed more antihyperglycemic agents, more often on a later therapy line receiving a GLP-1 receptor agonist, SGLT2i, or insulin, and more often tested their blood glucose levels than patients who were unaware. Physicians were not satisfied with the current blood glucose level of one third of their patients, believing that more of those who were aware of their HbA1c goal could achieve better glucose control (32.4% of aware vs. 28.2% of unaware patients; p = 0.003). Conclusions Our results showed that the proportion of patients with type 2 diabetes mellitus achieving their goals for glycemic control was suboptimal when compared to current guideline criteria, with only about 40% of patients achieving their individualized HbA1c goal. Treatment intensification was often delayed until HbA1c was 8% and higher. Patients aware of their HbA1c goal were slightly more adherent to their antihyperglycemic medication; however, awareness of HbA1c goal did not enhance goal attainment. This highlights the need for a holistic approach to diabetes management, involving patient education, and patient–physician communication and partnership. Supplementary Information The online version contains supplementary material available at 10.1007/s12325-021-01985-3.

Lens-free microscopes can utilize holographic reconstruction techniques to recover the image of an object from the digitally recorded superposition of an unperturbed plane wave and a wave scattered by the object. Image reconstruction most commonly relies on the scalar angular spectrum method (ASM). While fast, the scalar ASM can be inaccurate for nanoscale objects, either because of the scalar approximation, or more generally, because it only models field propagation and not light-matter interaction, including inter-particle coupling. Here we evaluate the accuracy of the scalar ASM when combined with three different light-matter interaction models for computing the far-field light scattered by random arrays of gold and polystyrene nanoparticles. Among the three models—a dipole-matched transmission model, an optical path length model, and a binary amplitude model—we find that which model is most accurate depends on the nanoparticle material and packing density. For polystyrene particles at any packing density, there is always at least one model with error below 20%, while for gold nanoparticles with 40% or 50% surface coverage, there are no models that can provide errors better than 30%. The ASM error is determined in comparison to a discrete dipole approximation model, which is more computationally efficient than other full-wave modeling techniques. The knowledge of when and how the ASM fails can serve as a first step toward improved resolution in lens-free reconstruction and can also be applied to other random nanoparticle array applications such as lens-based super-resolution imaging, sub-diffraction beam focusing, and biomolecular sensing.

Accurate, cost-effective, easy-to-use, and point-of-care sensors for protein biomarker levels are important for disease diagnostics. A cost-effective and compact readout approach that has been used for several diagnostic applications is lens-free holographic microscopy, which provides an ultralarge field of view and submicron resolution when it is coupled with pixel super-resolution techniques. Despite its potential as a diagnostic technique, lens-free microscopy has not previously been applied to quantitative protein molecule sensing in solution, which can simplify sensing protocols and ultimately enable measurements of binding kinetics in physiological conditions. Here, we sense interferon-γ (an immune system biomarker) and NeutrAvidin molecules in solution by combining lens-free microscopy with a one-step bead-based agglutination assay, enabled by a custom high-speed light-emitting diode (LED) array and automated image processing routines. We call this a quantitative large-area binding (QLAB) sensor. The high-speed light source provides, for the first time, pixel super-resolved imaging of >104 2 μm beads in solution undergoing Brownian motion, without significant motion blur. The automated image processing routines enable the counting of individual beads and clusters, providing a quantitative sensor readout that depends on both bead and analyte concentrations. Fits to the chemical binding theory are provided. For NeutrAvidin, we find a limit of detection (LOD) of

Whispering gallery mode resonators such as silica microtoroids can be used as sensitive biochemical sensors. One sensing modality is mode-splitting, where the binding of individual targets to the resonator breaks the degeneracy between clockwise and counter-clockwise resonant modes. Compared to other sensing modalities, mode-splitting is attractive because the signal shift is theoretically insensitive to the polar coordinate where the target binds. However, this theory relies on several assumptions, and previous experimental and numerical results have shown some discrepancies with analytical theory. More accurate numerical modeling techniques could help to elucidate the underlying physics, but efficient 3D electromagnetic finite-element method simulations of large microtoroid (diameter ~90 µm) and their resonance features have previously been intractable. In addition, applications of mode-splitting often involve bacteria or viruses, which are too large to be accurately described by the existing analytical dipole approximation theory. A numerical simulation approach could accurately explain mode splitting induced by these larger particles. Here, we simulate mode-splitting in a large microtoroid using a beam envelope method with periodic boundary conditions in a wedge-shaped domain. We show that particle sizing is accurate to within 11% for radii a<λ/7, where the dipole approximation is valid. Polarizability calculations need only be based on the background media and need not consider the microtoroid material. This modeling approach can be applied to other sizes and shapes of microresonators in the future.

Evidence from clinical trials suggest that newer antihyperglycemic agents (AHAs) have a better clinical profile at a higher dose. However, the utilization of the different doses in the real world is not well known. This study aimed to assess the dose utilization of the 2 newer classes of AHAs using the 2018 Adelphi T2DM Disease Specific Programme, a survey involving 730 physicians and 8794 patients in the U.S. and Europe. The analysis included 1612 patients on sodium glucose cotransporter 2 inhibitors (SGLT2i) and 1073 patients on glucagon like peptide-1 receptor agonist (GLP-1RA), either monotherapy or combined therapy. Dose cut points for SGLT2i drugs were based on doses utilized in cardiovascular outcomes trials (at a compound level, Table 1). There is no standard cut point on dosing in GLP-1RA, therefore a conservative approach was applied (see Table for details). Analyses were performed at class level. SGLT2i drugs were more likely to be prescribed at a high dose (85.7%) to patients who were slightly younger than those receiving a lower dose (57.1 vs. 58.9 years). GLP-1RA were prescribed at high dose in 63.2% of the patients. Mean BMI was higher in patients receiving high dose of a GLP-1 receptor agonist. Disclosure D. Lautsch: Employee; Self; Merck & Co., Inc. E. McLeod: Employee; Self; Pfizer Inc. Stock/Shareholder; Self; Pfizer Inc. T. Wang: Employee; Spouse/Partner; Janssen Pharmaceuticals, Inc. Employee; Self; Merck & Co., Inc. C.D. Gonzalez: Employee; Self; Merck & Co., Inc. S. Rajpathak: Employee; Self; Menarini Group. S. Malkani: None. J. Jackson: None. G. Milligan: None. V. Higgins: None. Funding Merck Sharp & Dohme Corp; Pfizer Inc.

Terahertz (THz) optics offer the potential to image through objects that are opaque for visible wavelengths and provide unique spectroscopic signatures for a variety of materials and quantum processes. However, the resolution of THz images suffers from the long wavelength of THz light compared to visible. Hyperbolic metamaterials provide a possible solution through the creation of super-resolving lenses and offer greater flexibility in effective refractive index than can be provided by natural materials. Most hyperbolic metamaterials function in a narrow bandwidth due to their resonant nature. In search of a broadband material, we simulate a temperature-tunable hyperbolic metamaterial composed of a multilayer stack of alternating layers of high-density polyethylene (HDPE) and indium antimonide (InSb). At a single temperature, negative effective medium permittivity is found over a small bandwidth of 0.09 THz, but by tuning over a 40°C temperature range the bandwidth is increased dramatically to 1.0 THz. Furthermore, we compute the transmission and negative refraction through the multilayer stack and simulate the imaging properties of curved hyperlens stacks using slits as test objects, achieving resolutions as small as 20 µm at 130 µm wavelength, far below the half-wavelength diffraction limit.

Lens-free holographic microscopy offers sub-micron resolution over an ultra-large field-of-view >20 mm2, making it suitable for bio-sensing applications that require the detection of small targets at low concentrations. Various pixel super-resolution techniques have been shown to enhance resolution and boost signal-to-noise ratio (SNR) by combining multiple partially-redundant low-resolution frames. However, it has been unclear which technique performs best for small-target sensing. Here, we quantitatively compare SNR and resolution in experiments using no regularization, cardinal-neighbor regularization, and a novel implementation of sparsity-promoting regularization that uses analytically-calculated gradients from Bayer-pattern image sensors. We find that sparsity-promoting regularization enhances the SNR by ~8 dB compared to the other methods when imaging micron-scale beads with surface coverages up to ~4%.

Introduction Ertugliflozin is a new sodium-glucose co-transporter-2 inhibitor (SGLT2i) for the treatment of type 2 diabetes mellitus. As there are no head-to-head trials comparing the efficacy of SGLT2is, the primary objective of this analysis was to indirectly compare ertugliflozin to other SGLT2i in patient populations with inadequately controlled glycated hemoglobin (HbA1c > 7.0%) and previously treated with either diet/exercise, metformin alone or metformin plus a dipeptidyl peptidase-4 inhibitor (DPP4i). Methods A systematic literature review (SLR) identified randomized controlled trials (RCTs) reporting outcomes at 24–26 weeks of treatment. Comparators to ertugliflozin were the SGLT2is canagliflozin, dapagliflozin and empagliflozin, with non-SGLT2i comparators also evaluated third-line [insulin and glucagon-like peptide-1 receptor agonists (GLP-1 RAs)]. Outcomes were change from baseline in HbA1c, weight and systolic blood pressure (SBP) as well as HbA1c

Objective: Indirectly compare the efficacy and safety of ertugliflozin (ERTU) from the VERTIS SITA2 trial to other treatments in patients with inadequate A1C control on MET+DPP-4i. Methods: Literature was searched up to end 2016 for RCTs in patients with A1C ≥7% on MET+DPP-4i. Included outcomes vs. placebo at 24-26 weeks were change in A1C, weight, systolic blood pressure, A1C Results: Interventions compared (+background therapies) were dapagliflozin 10mg (MET+sitagliptin [SITA] and MET+saxagliptin), empagliflozin 10/25mg (MET+linagliptin), titrated canagliflozin (MET+SITA), titrated liraglutide (MET) and ERTU 5/15mg (MET+SITA). No relevant insulin RCTs were found. Added to MET+SITA, ERTU 5 and 15mg were significantly more effective than dapagliflozin 10mg (A1C mean difference [MD] 5mg -0.29%, CrI -0.56, -0.02; 15mg -0.37%, CrI -0.64, -0.10). Comparisons to other SGLT2i regimens did not find significant differences in A1C or other outcomes. The liraglutide arm of LIRA SWITCH discontinued SITA. Sensitivity analysis comparing triple therapy (MET+SITA+ERTU) vs. dual therapy (MET+liraglutide) did not find significant differences (A1C MD 5mg -0.07%, CrI -0.35, 0.22, 15mg -0.15% CrI -0.43, 0.14). Conclusions: Amongst patients requiring triple therapy with SGLT2i added to MET+DPP-4i there was considerable heterogeneity between studies and assumptions of equivalence of background DPP-4i were required. Nonetheless, this analysis indicated that ERTU was more effective than dapagliflozin as add-on to MET+SITA and was comparable to other SGLT2i+MET+DPP-4i regimens. Disclosure A. McNeill: Employee; Self; Merck & Co., Inc.. Stock/Shareholder; Self; Merck & Co., Inc. G.M. Davies: Employee; Self; Merck & Co., Inc. E. Kruger: Employee; Self; QuintilesIMS. S.L. Kowal: None. F. Ejzykowicz: Employee; Self; Merck Sharp & Dohme Corp. H. Hannachi: Employee; Self; Merck & Co., Inc. N.B. Cater: Employee; Self; Peter Sheehan Diabetes Care Foundation, Inc. E. McLeod: Employee; Self; Pfizer Inc..

Objective: Indirectly compare the efficacy and safety of ertugliflozin (ertu) from the VERTIS MET and FACTORIAL trials to other SGLT2i as an add-on to MET. Methods: Pubmed, EMBASE and Cochrane databases were searched through to end 2016 for RCTs of 24-26 weeks duration in T2DM patients with uncontrolled A1C on MET. Comparators to ertu 5mg and 15mg were low and high doses of SGLT2i licensed in Europe and USA: canagliflozin (cana), dapagliflozin (dapa) and empagliflozin (empa). Included outcomes vs. placebo at 24-26 weeks were change in A1C, weight, systolic blood pressure (SBP), A1C Results: The NMA included 7 RCTs. Ertu was significantly more effective in reducing A1C than dapa doses (ertu 5mg vs. dapa 5mg mean difference (MD): -0.22%, CrI -0.42, -0.02; ertu 15mg vs. dapa 10mg MD:-0.26%, CrI -0.46, -0.06) and ertu 15mg was superior to empa 25mg (MD: -0.23%, CrI -0.44, -0.03). There were no further significant differences between ertu and other SGLT2i for change in A1C, SBP, weight, A1C Conclusions: Although reliant upon indirect comparison rather than head to head RCTs, ertu 5 and 15mg were superior to dapa 5 and 10mg, respectively, and ertu 15mg was superior to empa 25mg. Across remaining outcomes, both ertu doses added to MET were comparable to other SGLT2i. Disclosure A. McNeill: Employee; Self; Merck & Co., Inc.. Stock/Shareholder; Self; Merck & Co., Inc. G.M. Davies: Employee; Self; Merck & Co., Inc. E. Kruger: Employee; Self; QuintilesIMS. T. Reason: None. F. Ejzykowicz: Employee; Self; Merck Sharp & Dohme Corp. H. Hannachi: Employee; Self; Merck & Co., Inc. N.B. Cater: Employee; Self; Peter Sheehan Diabetes Care Foundation, Inc. E. McLeod: Employee; Self; Pfizer Inc..

Objective: Indirectly compare the efficacy and safety of ertugliflozin (ertu) from the VERTIS MONO trial to other SGLT2i when used as monotherapy. Methods: Pubmed, EMBASE and Cochrane were searched through to end of 2016 for RCTs of 24-26 weeks duration in T2DM patients with uncontrolled A1C on no anti-hyperglycemic therapy. Comparators to ertu 5mg and 15mg were low and high doses of SGLT2i licensed in Europe and USA: canagliflozin (cana), dapagliflozin (dapa) and empagliflozin (empa). Included outcomes vs. placebo at 24-26 weeks were change in A1C, weight loss (WL), systolic (SBP), A1C Results: The NMA included 10 RCTs with FE models selected for all analyses except A1C Conclusions: In an indirect comparison ertu 5mg was comparable to other low dose SGLT2i at reducing A1C whereas ertu 15mg was more effective vs. dapa 10mg and empa 25mg. With the exception of SBP for ertu 15mg vs. cana 300mg, remaining outcomes were comparable to other SGLT2i for both ertu 5mg and 15mg. Disclosure G.M. Davies: Employee; Self; Merck & Co., Inc. A. McNeill: Employee; Self; Merck & Co., Inc.. Stock/Shareholder; Self; Merck & Co., Inc. E. Kruger: Employee; Self; QuintilesIMS. S.L. Kowal: None. F. Ejzykowicz: Employee; Self; Merck Sharp & Dohme Corp. H. Hannachi: Employee; Self; Merck & Co., Inc. N.B. Cater: Employee; Self; Peter Sheehan Diabetes Care Foundation, Inc. E. McLeod: Employee; Self; Pfizer Inc..

Providing means for researchers and citizen scientists in the developing world to perform advanced measurements with nanoscale precision can help to accelerate the rate of discovery and invention as well as improve higher education and the training of the next generation of scientists and engineers worldwide. Here, we review some of the recent progress toward making optical nanoscale measurement tools more cost-effective, field-portable, and accessible to a significantly larger group of researchers and educators. We divide our review into two main sections: label-based nanoscale imaging and sensing tools, which primarily involve fluorescent approaches, and label-free nanoscale measurement tools, which include light scattering sensors, interferometric methods, photonic crystal sensors, and plasmonic sensors. For each of these areas, we have primarily focused on approaches that have either demonstrated operation outside of a traditional laboratory setting, including for example integration with mobile phones, or exhibited the potential for such operation in the near future.

Slender liquid nanofilms exposed to large surface thermal gradients are known to undergo thickness fluctuations which rapidly self-organize into arrays of nanoprotrusions with a separation distance of tens of microns. We previously reported good agreement between measurements of the characteristic spacing and the wavelength of the most unstable mode predicted by a linear stability analysis based on a long wavelength thermocapillary model. Here we focus on differential colorimetry measurements to quantify early time out-of-plane growth of protrusions for peak heights spanning 20 to 200 nm. Analysis of peak heights based on shape reconstruction reveals robust exponential growth. Good quantitative agreement of the growth rates with the thermocapillary model is obtained using a single fit constant to account for material parameters of nanofilms that could not be measured directly. These findings lend further support to the conjecture that the array protrusions uncovered almost two decades ago stem from a linear instability whose growth rate is controlled by thermocapillary forces counterbalanced by capillary forces., Comment: 12 pages, 8 figures, 5 tables

Caused by the herpes simplex virus (HSV), herpes is a viral infection that is one of the most widespread diseases worldwide. Here we present a computational sensing technique for specific detection of HSV using both viral immuno-specificity and the physical size range of the viruses. This label-free approach involves a compact and cost-effective holographic on-chip microscope and a surface-functionalized glass substrate prepared to specifically capture the target viruses. To enhance the optical signatures of individual viruses and increase their signal-to-noise ratio, self-assembled polyethylene glycol based nanolenses are rapidly formed around each virus particle captured on the substrate using a portable interface. Holographic shadows of specifically captured viruses that are surrounded by these self-assembled nanolenses are then reconstructed, and the phase image is used for automated quantification of the size of each particle within our large field-of-view, ~30 mm2. The combination of viral immuno-specificity due to surface functionalization and the physical size measurements enabled by holographic imaging is used to sensitively detect and enumerate HSV particles using our compact and cost-effective platform. This computational sensing technique can find numerous uses in global health related applications in resource-limited environments.

Significant progress in characterization of nanoparticles and biomolecules was enabled by the development of advanced imaging equipment with extreme spatial-resolution and sensitivity. To perform some of these analyses outside of well-resourced laboratories, it is necessary to create robust and cost-effective alternatives to existing high-end laboratory-bound imaging and sensing equipment. Towards this aim, we have designed a holographic on-chip microscope operating at an ultraviolet illumination wavelength (UV) of 266 nm. The increased forward scattering from nanoscale objects at this short wavelength has enabled us to detect individual sub-30 nm nanoparticles over a large field-of-view of >16 mm2 using an on-chip imaging platform, where the sample is placed at ≤0.5 mm away from the active area of an opto-electronic sensor-array, without any lenses in between. The strong absorption of this UV wavelength by biomolecules including nucleic acids and proteins has further enabled high-contrast imaging of nanoscopic aggregates of biomolecules, e.g., of enzyme Cu/Zn-superoxide dismutase, abnormal aggregation of which is linked to amyotrophic lateral sclerosis (ALS) - a fatal neurodegenerative disease. This UV-based wide-field computational imaging platform could be valuable for numerous applications in biomedical sciences and environmental monitoring, including disease diagnostics, viral load measurements as well as air- and water-quality assessment.

Imaging object details with length scales below approximately 200 nm has been historically difficult for conventional microscope objective lenses because of their inability to resolve features smaller than one-half the optical wavelength. Here we review some of the recent approaches to surpass this limit by harnessing self-assembly as a fabrication mechanism. Self-assembly can be used to form individual nano- and micro-lenses, as well as to form extended arrays of such lenses. These lenses have been shown to enable imaging with resolutions as small as 50 nm half-pitch using visible light, which is well below the Abbe diffraction limit. Furthermore, self-assembled nano-lenses can be used to boost contrast and signal levels from small nano-particles, enabling them to be detected relative to background noise. Finally, alternative nano-imaging applications of self-assembly are discussed, including three-dimensional imaging, enhanced coupling from light-emitting diodes, and the fabrication of contrast agents such as quantum dots and nanoparticles.

Ultra-high quality (Q) whispering gallery mode (WGM) microtoroid optical resonators have demonstrated highly sensitive biomolecular detection down to the single molecule limit; however, the lack of a robust coupling method has prevented their widespread adoption outside the laboratory. We demonstrate through simulation that a phased array of nanorods can enable free-space coupling of light both into and out of a microtoroid while maintaining a high Q. To simulate large nanostructured WGM resonators, we developed a new approach known as FloWBEM, which is an efficient and compact 3D wedge model with custom boundary conditions that accurately simulate the resonant Fano interference between the traveling WGM waves and a nanorod array. Depending on the excitation conditions, we find loaded Q factors of the driven system as high as 2.1×107 and signal-to-background ratios as high as 3.86%, greater than the noise levels of many commercial detectors. These results can drive future experimental implementation.

Whispering gallery mode (WGM) microtoroid optical resonators have been effectively used to sense low concentrations of biomolecules down to the single molecule limit. Optical WGM biochemical sensors such as the microtoroid operate by tracking changes in resonant frequency as particles enter the evanescent near field of the resonator. Previously, gold nanoparticles have been coupled to WGM resonators to increase the magnitude of resonance shifts via plasmonic enhancement of the electric field. However, this approach results in increased scattering from the WGM, which degrades its quality (Q) factor, making it less sensitive to extremely small frequency shifts caused by small molecules or protein conformational changes. Here, we show using simulation that precisely positioned trimer gold nanostructures generate dark modes that suppress radiation loss and can achieve high (>106) Q with an electric-field intensity enhancement of 4300, which far exceeds that of a single rod (∼2500 times). Through an overall evaluation of a combined enhancement factor, which includes the Q factor of the system, the sensitivity of the trimer system was improved 105× versus 84× for a single rod. Further simulations demonstrate that unlike a single rod system, the trimer is robust to orientation changes and has increased capture area. We also conduct stability tests to show that small positioning errors do not greatly impact the result.

The direct observation of nanoscale objects is a challenging task for optical microscopy because the scattering from an individual nanoparticle is typically weak at optical wavelengths. Electron microscopy therefore remains one of the gold standard visualization methods for nanoparticles, despite its high cost, limited throughput and restricted field-of-view. Here, we describe a high-throughput, on-chip detection scheme that uses biocompatible wetting films to self-assemble aspheric liquid nanolenses around individual nanoparticles to enhance the contrast between the scattered and background light. We model the effect of the nanolens as a spatial phase mask centred on the particle and show that the holographic diffraction pattern of this effective phase mask allows detection of sub-100 nm particles across a large field-of-view of >20 mm2. As a proof-of-concept demonstration, we report on-chip detection of individual polystyrene nanoparticles, adenoviruses and influenza A (H1N1) viral particles.

Background Venous thromboembolism (VTE) is a burden on healthcare systems. Standard treatment involves parenteral anticoagulation overlapping with a vitamin K antagonist, an approach that is effective but associated with limitations including the need for frequent coagulation monitoring. The direct oral anticoagulant rivaroxaban is similarly effective to standard therapy as a single-drug treatment for VTE and does not require routine coagulation monitoring. The objective of this economic evaluation was to estimate the cost-effectiveness of rivaroxaban compared with standard VTE treatment from a UK perspective. Methods A Markov model was constructed using data and probabilities derived from the EINSTEIN DVT and EINSTEIN PE studies of rivaroxaban and other published sources. Health outcomes included VTE rates, bleeding events avoided, quality-adjusted life-years (QALYs) and incremental cost-effectiveness ratios (ICERs). Results There was greater discounted quality-adjusted life expectancy with rivaroxaban than with standard therapy, irrespective of indication and treatment duration. Rivaroxaban was associated with per-patient cost savings for each treatment duration modelled (3, 6 and 12 months), and these were greatest with shorter durations. Rivaroxaban was found to be dominant (cheaper and more effective) and, therefore, cost-effective, in both patients with deep vein thrombosis and pulmonary embolism in all three treatment duration groups, and was also cost-effective in patients requiring lifelong anticoagulation (ICERs: £8677 per QALY and £7072 per QALY in patients with index deep vein thrombosis and pulmonary embolism, respectively). The cost-effectiveness of rivaroxaban was largely insensitive to variations in one-way sensitivity analysis. Probabilistic sensitivity analysis demonstrated that at a threshold of £20,000 per QALY, rivaroxaban had a consistent probability of being cost-effective, compared with LMWH/VKA treatment, of around 80% regardless of index VTE or duration of anticoagulation therapy (3, 6, 12 months or lifelong). Conclusions This analysis suggests that rivaroxaban represents a cost-effective choice for acute treatment of deep vein thrombosis and pulmonary embolism and secondary prevention of VTE in the UK, compared with LMWH/VKA treatment, regardless of the required treatment duration. Electronic supplementary material The online version of this article (doi:10.1186/s12959-015-0051-3) contains supplementary material, which is available to authorized users.

In fluorescence microscopy, the signal-to-noise ratio (SNR) of the optical system is directly linked to the numerical aperture (NA) of the microscope objective, which creates detection challenges for low-NA, wide-field and high-throughput imaging systems. Here we demonstrate a method to increase the light collection efficiency from micron-scale fluorescent objects using self-assembled vapor-condensed polyethylene glycol droplets, which act as micro-reflectors for fluorescent light. Around each fluorescent particle, a liquid meniscus is formed that increases the excitation efficiency and redirects part of the laterally-emitted fluorescent light towards the detector due to internal reflections at the liquid-air interface of the meniscus. The three-dimensional shape of this micro-reflector can be tuned as a function of time, vapor temperature and substrate contact angle, providing us optimized SNR performance for fluorescent detection. Based on these self-assembled micro-reflectors, we experimentally demonstrate ~2.5-3 fold enhancement of the fluorescent signal from 2-10 μm sized particles. A theoretical explanation of the formation rate and shapes of these micro-reflectors is presented, along with a ray tracing model of their optical performance. This method can be used as a sample preparation technique for consumer electronics-based microscopy and sensing tools, thus increasing the sensitivity of low-NA systems that image fluorescent micro-objects.

Sizing individual nanoparticles and dispersions of nanoparticles provides invaluable information in applications such as nanomaterial synthesis, air and water quality monitoring, virology, and medical diagnostics. Several conventional nanoparticle sizing approaches exist; however, there remains a lack of high-throughput approaches that are suitable for low-resource and field settings, i.e., methods that are cost-effective, portable, and can measure widely varying particle sizes and concentrations. Here we fill this gap using an unconventional approach that combines holographic on-chip microscopy with vapor-condensed nanolens self-assembly inside a cost-effective hand-held device. By using this approach and capturing time-resolved in situ images of the particles, we optimize the nanolens formation process, resulting in significant signal enhancement for the label-free detection and sizing of individual deeply subwavelength particles (smaller than lambda/10) over a 30 mm(2) sample field-of-view, with an accuracy of +/- 11 nm. These time-resolved measurements are significantly more reliable than a single measurement at a given time, which was previously used only for nanoparticle detection without sizing. We experimentally demonstrate the sizing of individual nanoparticles as well as viruses, monodisperse samples, and complex polydisperse mixtures, where the sample concentrations can span similar to 5 orders-of-magnitude and particle sizes can range from 40 nm to millimeter-scale. We believe that this high-throughput and label-free nanoparticle sizing platform, together with its cost-effective and hand-held interface, will make highly advanced nanoscopic measurements readily accessible to researchers in developing countries and even to citizen-scientists, and might especially be valuable for environmental and biomedical applications as well as for higher education and training programs.

Venous thromboembolism is a burden on healthcare systems. The aim of this analysis was to project the long-term costs and outcomes for rivaroxaban compared to standard of care (enoxaparin/warfarin) in Portugal for the treatment and secondary prevention of venous thromboembolism.A Markov model was developed using event rates extracted from the EINSTEIN trials supplemented with literature-based estimates of longer-term outcomes. Core outcomes included per patient costs and quality-adjusted life years reported separately per treatment arm and incrementally, as well as cost per quality-adjusted life years gained. The deep vein thrombosis and pulmonary embolism indications were analysed separately. The analyses were conducted from the Portuguese societal perspective and over a 5-year time horizon. Costs and outcomes were discounted at a 5% annual rate. Several scenario analyses were undertaken to explore the impact on results of varying key modeling assumptions.Rivaroxaban treatment was associated with cost-savings for the treatment of deep vein thrombosis and was both cost-saving and more effective for the treatment of pulmonary embolism, compared with enoxaparin/warfarin.The results of the sensitivity and scenario analyses further supported that rivaroxaban is a cost-effective alternative to standard of care treatment. The use of an expert panel to derive some input values and the lack of Portuguese specific utilities were the main limitations.Rivaroxaban represents an efficient alternative to using enoxaparin/warfarin in Portugal, as it's associated with lower costs (for both indications) and greater quality adjusted life years (for the pulmonary embolism indication).Introdução: O tromboembolismo venoso representa uma carga substancial para os sistemas de saúde. O objectivo foi estimar os resultados clínicos e económicos a longo-prazo associados a rivaroxabano relativamente à prática clínica (enoxaparina/varfarina) no tratamento e prevenção secundária de tromboembolismo venoso em Portugal.Material e Métodos: Foi desenvolvido um modelo de Markov baseado nos ensaios clínicos EINSTEIN e dados da literatura para complicações a longo-prazo. Foram avaliados custos e anos de vida ajustados pela qualidade de vida totais e incrementais e rácio custo-efectividade incremental. As indicações trombose venosa profunda e embolismo pulmonar foram analisados separadamente. Adoptou-se a perspectiva da sociedade portuguesa e um horizonte temporal de cinco anos. Aplicou-se uma taxa de actualização de cinco por cento para custos e consequências. Foram desenvolvidas análises de sensibilidade e diversas análises de cenário para avaliação da variação dos resultados em função de determinados pressupostos.Resultados: Rivaroxabano está associado a menores custos na trombose venosa profunda e constitui uma alternativa associada a menores custos e a maior eficácia no tratamento de embolismo pulmonar, relativamente a enoxaparina/varfarina.Discussão: O recurso a um painel de peritos para identificação de alguns recursos e a ausência de utilidades específicas para Portugal constituem as principais limitações.Conclusão: Rivaroxabano constitui uma alternativa eficaz, estando associado a menores custos (para ambas as indicações) e a mais anos de vida ajustados pela qualidade de vida (para embolismo pulmonar) relativamente a enoxaparina/varfarina em Portugal.

Nanostructured optical components, such as nanolenses, direct light at subwavelength scales to enable, among others, high-resolution lithography, miniaturization of photonic circuits, and nanoscopic imaging of biostructures. A major challenge in fabricating nanolenses is the appropriate positioning of the lens with respect to the sample while simultaneously ensuring it adopts the optimal size and shape for the intended use. One application of particular interest is the enhancement of contrast and signal-to-noise ratio in the imaging of nanoscale objects, especially over wide fields-of-view (FOVs), which typically come with limited resolution and sensitivity for imaging nano-objects. Here we present a self-assembly method for fabricating time- and temperature-tunable nanolenses based on the condensation of a polymeric liquid around a nanoparticle, which we apply to the high-throughput on-chip detection of spheroids smaller than 40 nm, rod-shaped particles with diameter smaller than 20 nm, and biofunctionalized nanoparticles, all across an ultralarge FOV of >20 mm(2). Previous nanoparticle imaging efforts across similar FOVs have detected spheroids no smaller than 100 nm, and therefore our results demonstrate the detection of particles >15-fold smaller in volume, which in free space have >240 times weaker Rayleigh scattering compared to the particle sizes detected in earlier wide-field imaging work. This entire platform, with its tunable nanolens condensation and wide-field imaging functions, is also miniaturized into a cost-effective and portable device, which might be especially important for field use, mobile sensing, and diagnostics applications, including, for example, the measurement of viral load in bodily fluids.

The physical interaction between nano-scale objects and liquid interfaces can create unique optical properties, enhancing the signatures of the objects with sub-wavelength features. Here we show that the evaporation on a wetting substrate of a polymer solution containing sub-micrometer or nano-scale particles creates liquid micro-lenses that arise from the local deformations of the continuous wetting film. These micro-lenses have properties similar to axicon lenses that are known to create beams with a long depth of focus. This enhanced depth of focus allows detection of single nanoparticles using a low magnification microscope objective lens, achieving a relatively wide field-of-view, while also lifting the constraints on precise focusing onto the object plane. Hence, by creating these liquid axicon lenses through spatial deformations of a continuous thin wetting film, we transfer the challenge of imaging individual nano-particles to detecting the light focused by these lenses. As a proof of concept, we demonstrate the detection and sizing of single nano-particles (100 and 200 nm), CpGV granuloviruses as well as Staphylococcus epidermidis bacteria over a wide field of view of e.g., 5.10×3.75 mm2 using a ×5 objective lens with a numerical aperture of 0.15. In addition to conventional lens-based microscopy, this continuous wetting film based approach is also applicable to lensfree computational on-chip imaging, which can be used to detect single nano-particles over a large field-of-view of e.g., >20-30 mm2. These results could be especially useful for high-throughput field-analysis of nano-scale objects using compact and cost-effective microscope designs.

The development of lensfree on-chip microscopy in the past decade has opened up various new possibilities for biomedical imaging across ultra-large fields of view using compact, portable, and cost-effective devices. However, until recently, its ability to resolve fine features and detect ultra-small particles has not rivalled the capabilities of the more expensive and bulky laboratory-grade optical microscopes. In this Frontier Review, we highlight the developments over the last two years that have enabled computational lensfree holographic on-chip microscopy to compete with and, in some cases, surpass conventional bright-field microscopy in its ability to image nano-scale objects across large fields of view, yielding giga-pixel phase and amplitude images. Lensfree microscopy has now achieved a numerical aperture as high as 0.92, with a spatial resolution as small as 225 nm across a large field of view e.g., >20 mm2. Furthermore, the combination of lensfree microscopy with self-assembled nanolenses, forming nano-catenoid minimal surfaces around individual nanoparticles has boosted the image contrast to levels high enough to permit bright-field imaging of individual particles smaller than 100 nm. These capabilities support a number of new applications, including, for example, the detection and sizing of individual virus particles using field-portable computational on-chip microscopes.

We report the discovery of an entirely new three-dimensional (3D) swimming pattern observed in human and horse sperms. This motion is in the form of 'chiral ribbons', where the planar swing of the sperm head occurs on an osculating plane creating in some cases a helical ribbon and in some others a twisted ribbon. The latter, i.e., the twisted ribbon trajectory, also defines a minimal surface, exhibiting zero mean curvature for all the points on its surface. These chiral ribbon swimming patterns cannot be represented or understood by already known patterns of sperms or other micro-swimmers. The discovery of these unique patterns is enabled by holographic on-chip imaging of >33,700 sperm trajectories at >90-140 frames/sec, which revealed that only ~1.7% of human sperms exhibit chiral ribbons, whereas it increases to ~27.3% for horse sperms. These results might shed more light onto the statistics and biophysics of various micro-swimmers' 3D motion.

Computational microscopy tools, in particular lensfree on-chip imaging, provide a large field-of-view along with a long depth-of-field, which makes it feasible to rapidly analyze large volumes of specimen using a compact and light-weight on-chip imaging architecture. To bring molecular specificity to this high-throughput platform, here we demonstrate the use of plasmon-resonant metallic nanoparticles to automatically recognize different cell types based on their plasmon-enhanced lensfree holograms, detected and reconstructed over a large field-of-view of e.g., ~24 mm².

Nanofabrication using near-field optical probes is an established technique for rapid prototyping and automated maskless fabrication of nanostructured devices. In this review, we present the primary types of near-field probes and their physical processing mechanisms. Highlights of recent developments include improved resolution by optimizing the probe shape, incorporation of surface plasmonics in probe design, broader use in biological and magnetic storage applications, and increased throughput using probe arrays as well as high speed writing and patterning.

Thermocapillary lithography, a continuous-relief patterning technique, is used to fabricate polymer microlens arrays with variable pitch and focal length. Pattern definition results from sculpting by thermocapillary forces imposed by a cooled mask.

The free surface of molten nanofilms is known to undergo spontaneous formation of periodic protrusions when exposed to a large transverse thermal gradient. Early time measurements of the array pitch and growth rate in polymer melts confirm a formation process based on a long wavelength thermocapillary instability and not electrostatic attraction or acoustic phonon driven growth as previously believed. We find excellent agreement with theoretical predictions provided the nanofilm out-of-plane thermal conductivity is several times larger than bulk, an enhancement suggestive of polymer chain alignment.

Current demands on optical nanolithography require the ability to rapidly and cost-effectively write arbitrary patterns over large areas with sub-diffraction limit feature sizes. The challenge in accomplishing this with arrays of near-field probes is maintaining equal separations between the substrate and each probe, even over non-planar substrates. Here we demonstrate array-based laser nanolithography where each probe is a microsphere capable of fabricating 100 nm structures using 355 nm light when self-positioned near a surface by Bessel beam optical trapping. We achieve both a feature size uniformity and relative positioning accuracy better than 15 nm, which agrees well with our model. Further improvements are possible using higher power and/or narrower Bessel beam optical traps.

[Background and Aims] Vibration-controlled transient elastography (VCTE), point shear wave elastography (pSWE), 2-dimensional shear wave elastography (2DSWE), magnetic resonance elastography (MRE), and magnetic resonance imaging (MRI) have been proposed as non-invasive tests for patients with non-alcoholic fatty liver disease (NAFLD). This study evaluated their diagnostic accuracy for liver fibrosis and non-alcoholic steatohepatitis (NASH)., [Methods] PubMED/MEDLINE, EMBASE and the Cochrane Library were searched for studies examining the diagnostic accuracy of these index tests, against histology as the reference standard, in adult patients with NAFLD. Two authors independently screened and assessed methodological quality of studies and extracted data. Summary estimates of sensitivity, specificity and area under the curve (sAUC) were calculated for fibrosis stages and NASH, using a random effects bivariate logit-normal model., [Results] We included 82 studies (14,609 patients). Meta-analysis for diagnosing fibrosis stages was possible in 53 VCTE, 11 MRE, 12 pSWE and 4 2DSWE studies, and for diagnosing NASH in 4 MRE studies. sAUC for diagnosis of significant fibrosis were: 0.83 for VCTE, 0.91 for MRE, 0.86 for pSWE and 0.75 for 2DSWE. sAUC for diagnosis of advanced fibrosis were: 0.85 for VCTE, 0.92 for MRE, 0.89 for pSWE and 0.72 for 2DSWE. sAUC for diagnosis of cirrhosis were: 0.89 for VCTE, 0.90 for MRE, 0.90 for pSWE and 0.88 for 2DSWE. MRE had sAUC of 0.83 for diagnosis of NASH. Three (4%) studies reported intention-to-diagnose analyses and 15 (18%) studies reported diagnostic accuracy against pre-specified cut-offs., [Conclusions] When elastography index tests are acquired successfully, they have acceptable diagnostic accuracy for advanced fibrosis and cirrhosis. The potential clinical impact of these index tests cannot be assessed fully as intention-to-diagnose analyses and validation of pre-specified thresholds are lacking., [Lay summary] Non-invasive tests that measure liver stiffness or use magnetic resonance imaging (MRI) have been suggested as alternatives to liver biopsy for assessing the severity of liver scarring (fibrosis) and fatty inflammation (steatohepatitis) in patients with non-alcoholic fatty liver disease (NAFLD). In this study, we summarise the results of previously published studies on how accurately these non-invasive tests can diagnose liver fibrosis and inflammation, using liver biopsy as the reference. We found that some techniques that measure liver stiffness had a good performance for the diagnosis of severe liver scarring., This work has been undertaken as part of the LITMUS (Liver Investigation: Testing Marker Utility in Steatohepatitis) project. The LITMUS project has received funding from the Innovative Medicines Initiative 2 Joint Undertaking under grant agreement No. 777377. This Joint Undertaking receives support from the European Union’s Horizon 2020 research and innovation programme and Europen Federation of Pharmaceutical Industries and Associations (efpia.eu).