Sepsis awareness and knowledge amongst nurses, physicians and paramedics of a tertiary care center in Switzerland: A survey-based cross-sectional study.

BACKGROUND: Sepsis is a leading cause of morbidity and mortality. Prompt recognition and management are critical to improve outcomes. METHODS: We conducted a survey among nurses and physicians of all adult departments of the Lausanne University Hospital (LUH) and paramedics transporting patients to our hospital. Measured outcomes included professionals' demographics (age, profession, seniority, unit of activity), quantification of prior sepsis education, self-evaluation, and knowledge of sepsis epidemiology, definition, recognition, and management. Correlation between surveyed personnel and sepsis perceptions and knowledge were assessed with univariable and multivariable logistic regression models. RESULTS: Between January and October 2020, we contacted 1'216 of the 4'417 professionals (27.5%) of the LUH, of whom 1'116 (91.8%) completed the survey, including 619 of 2'463 (25.1%) nurses, 348 of 1'664 (20.9%) physicians and 149 of 290 (51.4%) paramedics. While 98.5% of the participants were familiar with the word "sepsis" (97.4% of nurses, 100% of physicians and 99.3% of paramedics), only 13% of them (physicians: 28.4%, nurses: 5.9%, paramedics: 6.8%) correctly identified the Sepsis-3 consensus definition. Similarly, only 48% and 49.3% of the physicians and 10.1% an 11.9% of the nurses knew that SOFA was a sepsis defining score and that the qSOFA score was a predictor of increased mortality, respectively. Furthermore, 15.8% of the physicians and 1.0% of the nurses knew the three components of the qSOFA score. For patients with suspected sepsis, 96.1%, 91.6% and 75.8% of physicians respectively chose blood cultures, broad-spectrum antibiotics and fluid resuscitation as therapeutic interventions to be initiated within 1 (76.4%) to 3 (18.2%) hours. For nurses and physicians, recent training correlated with knowledge of SOFA score (ORs [95%CI]: 3.956 [2.018-7.752] and 2.617 [1.527-4.485]) and qSOFA (ORs [95%CI]: 5.804 [2.653-9.742] and 2.291 [1.342-3.910]) scores purposes. Furthermore, recent training also correlated with adequate sepsis definition (ORs [95%CI]: 1.839 [1.026-3.295]) and the components of qSOFA (ORs [95%CI]: 2.388 [1.110-5.136]) in physicians. CONCLUSIONS: This sepsis survey conducted among physicians, nurses and paramedics of a tertiary Swiss medical center identified a deficit of sepsis awareness and knowledge reflecting a lack of sepsis-specific continuing education requiring immediate corrective measures.

National Early Warning Score (NEWS) Outperforms Quick Sepsis-Related Organ Failure (qSOFA) Score for Early Detection of Sepsis in the Emergency Department.

Background: Prompt recognition of sepsis is critical to improving patients' outcomes. We compared the performance of NEWS and qSOFA scores as sepsis detection tools in patients admitted to the emergency department (ED) with suspicion of sepsis. Methodology: A single-center 12-month retrospective study comparing NEWS using the recommended cut-off of ≥5 and qSOFA as sepsis screening tools in a cohort of patients transported by emergency medical services (EMS) to the Lausanne University Hospital (LUH). We used the Sepsis-3 consensus definition. The primary study endpoint was the detection of sepsis. Secondary endpoints were ICU admission and 28-day all-cause mortality. Results: Among 886 patients admitted to ED by EMS for suspected infection, 556 (63%) had a complete set of vital parameters panel enabling the calculation of NEWS and qSOFA scores, of whom 300 (54%) had sepsis. For the detection of sepsis, the sensitivity of NEWS > 5 was 86% and that of qSOFA ≥ 2 was 34%. Likewise, the sensitivities of NEWS ≥ 5 for predicting ICU admission and 28-day mortality were higher than those of qSOFA ≥ 2 (82% versus 33% and 88% versus 37%). Conversely, the specificity of qSOFA ≥ 2 for sepsis detection was higher than that of NEWS ≥ 5 (90% versus 55%). The negative predictive value of NEWS > 5 was higher than that of qSOFA ≥ 2 (77% versus 54%), while the positive predictive value of qSOFA ≥ 2 was higher than that of NEWS ≥ 5 (80% versus 69%). Finally, the accuracy of NEWS ≥ 5 was higher than that of qSOFA ≥ 2 (72% versus 60%). Conclusions: The sensitivity of NEWS ≥ 5 was superior to that of qSOFA ≥ 2 to identify patients with sepsis in the ED and predict ICU admission and 28-day mortality. In contrast, qSOFA ≥ 2 had higher specificity and positive predictive values than NEWS ≥ 5 for these three endpoints.

Performance of the Digital Dietary Assessment Tool MyFoodRepo.

Digital dietary assessment devices could help overcome the limitations of traditional tools to assess dietary intake in clinical and/or epidemiological studies. We evaluated the accuracy of the automated dietary app MyFoodRepo (MFR) against controlled reference values from weighted food diaries (WFD). MFR's capability to identify, classify and analyze the content of 189 different records was assessed using Cohen and uniform kappa coefficients and linear regressions. MFR identified 98.0% ± 1.5 of all edible components and was not affected by increasing numbers of ingredients. Linear regression analysis showed wide limits of agreement between MFR and WFD methods to estimate energy, carbohydrates, fat, proteins, fiber and alcohol contents of all records and a constant overestimation of proteins, likely reflecting the overestimation of portion sizes for meat, fish and seafood. The MFR mean portion size error was 9.2% ± 48.1 with individual errors ranging between -88.5% and +242.5% compared to true values. Beverages were impacted by the app's difficulty in correctly identifying the nature of liquids (41.9% ± 17.7 of composed beverages correctly classified). Fair estimations of portion size by MFR, along with its strong segmentation and classification capabilities, resulted in a generally good agreement between MFR and WFD which would be suited for the identification of dietary patterns, eating habits and regime types.

Development and validation of a knowledge-based score to predict Fried's frailty phenotype across multiple settings using one-year hospital discharge data: The electronic frailty score.

Background: Most claims-based frailty instruments have been designed for group stratification of older populations according to the risk of adverse health outcomes and not frailty itself. We aimed to develop and validate a tool based on one-year hospital discharge data for stratification on Fried's frailty phenotype (FP). Methods: We used a three-stage development/validation approach. First, we created a clinical knowledge-driven electronic frailty score (eFS) calculated as the number of deficient organs/systems among 18 critical ones identified from the International Statistical Classification of Diseases and Related Problems, 10th Revision (ICD-10) diagnoses coded in the year before FP assessment. Second, for eFS development and internal validation, we linked individual records from the Lc65+ cohort database to inpatient discharge data from Lausanne University Hospital (CHUV) for the period 2004-2015. The development/internal validation sample included community-dwelling, non-institutionalised residents of Lausanne (Switzerland) recruited in the Lc65+ cohort in three waves (2004, 2009, and 2014), aged 65-70 years at enrolment, and hospitalised at the CHUV at least once in the year preceding the FP assessment. Using this sample, we selected the best performing model for predicting the dichotomised FP, with the eFS or ICD-10-based variables as predictors. Third, we conducted an external validation using 2016 Swiss nationwide hospital discharge data and compared the performance of the eFS model in predicting 13 adverse outcomes to three models relying on well-designed and validated claims-based scores (Claims-based Frailty Index, Hospital Frailty Risk Score, Dr Foster Global Frailty Score). Findings: In the development/internal validation sample (n = 469), 14·3% of participants (n = 67) were frail. Among 34 models tested, the best-subsets logistic regression model with four predictors (age and sex at FP assessment, time since last hospital discharge, eFS) performed best in predicting the dichotomised FP (area under the curve=0·71; F1 score=0·39) and one-year adverse health outcomes. On the external validation sample (n = 54,815; 153 acute care hospitals), the eFS model demonstrated a similar performance to the three other claims-based scoring models. According to the eFS model, the external validation sample showed an estimated prevalence of 56·8% (n = 31,135) of frail older inpatients at admission. Interpretation: The eFS model is an inexpensive, transportable and valid tool allowing reliable group stratification and individual prioritisation for comprehensive frailty assessment and may be applied to both hospitalised and community-dwelling older adults. Funding: The study received no external funding.

Epidemiology, risk factors and clinical course of SARS-CoV-2 infected patients in a Swiss university hospital: An observational retrospective study.

BACKGROUND: This study aims to describe the epidemiology of COVID-19 patients in a Swiss university hospital. METHODS: This retrospective observational study included all adult patients hospitalized with a laboratory confirmed SARS-CoV-2 infection from March 1 to March 25, 2020. We extracted data from electronic health records. The primary outcome was the need to mechanical ventilation at day 14. We used multivariate logistic regression to identify risk factors for mechanical ventilation. Follow-up was of at least 14 days. RESULTS: 145 patients were included in the multivariate model, of whom 36 (24.8%) needed mechanical ventilation at 14 days. The median time from symptoms onset to mechanical ventilation was 9·5 days (IQR 7.00, 12.75). Multivariable regression showed increased odds of mechanical ventilation with age (OR 1.09 per year, 95% CI 1.03-1.16, p = 0.002), in males (OR 6.99, 95% CI 1.68-29.03, p = 0.007), in patients who presented with a qSOFA score ≥2 (OR 7.24, 95% CI 1.64-32.03, p = 0.009), with bilateral infiltrate (OR 18.92, 3.94-98.23, p<0.001) or with a CRP of 40 mg/l or greater (OR 5.44, 1.18-25.25; p = 0.030) on admission. Patients with more than seven days of symptoms on admission had decreased odds of mechanical ventilation (0.087, 95% CI 0.02-0.38, p = 0.001). CONCLUSIONS: This study gives some insight in the epidemiology and clinical course of patients admitted in a European tertiary hospital with SARS-CoV-2 infection. Age, male sex, high qSOFA score, CRP of 40 mg/l or greater and a bilateral radiological infiltrate could help clinicians identify patients at high risk for mechanical ventilation.

Automated solvent vapor annealing with nanometer scale control of film swelling for block copolymer thin films.

Molecular self-assembly of block copolymers has been pursued as a next generation high-resolution, low-cost lithography technique. Solvent vapor annealing is a promising way of achieving self-assembled patterns from polymers with high interaction parameters, χ, or high molecular weights. Compared to thermal annealing, the assembly in a solvated state can be much faster, but the film swelling process is typically challenging to control and reproduce. We report the design and implementation of an automated solvent annealing system that addresses these issues. In this system the film swelling is controlled via local heating or cooling, which enables exceptionally fast and precise modulation of the swelling. The swelling of the polymer films follows preprogrammed annealing profiles with the help of a feedback loop that compares and tunes the film thickness with respect to the set point. The system therefore enables complex annealing profiles such as rapid cyclic swelling and deswelling. We show that the orientation of the pattern morphology and the amount of lattice defects are influenced by the used annealing profile. We demonstrate that optimized profiles significantly shorten the annealing time (<15 min) of high-χ and high-molecular weight poly(styrene-b-2-vinylpyridine).

High molecular weight block copolymer lithography for nanofabrication of hard mask and photonic nanostructures.

An unusual dot pattern was realized via self-assembly of high molecular weight polystyrene-block-polydimethylsiloxane (PS-b-PDMS) copolymer by a simple one-step solvent annealing process, optimized based on Hansen solubility parameters. Annealing PS-b-PDMS under neutral solvent vapors at room temperature produces an ordered arrangement of dots with ∼112 nm spacing and ∼54 nm diameter. The template is highly resistant to dry etching with chlorine-based plasma, enabling its utilization on a variety of hard masks and substrates. The self-assembled PDMS dots were further exploited as a template for direct patterning of silicon, metal, and dielectric materials. This nanopatterning methodology circumvents expensive and time-consuming atomic layer deposition, wet processes, and sequential infiltration techniques. Application-wise, we show a process to fabricate nanostructured antireflection surfaces (nanocones) on a 2 in. silicon wafer, reducing the reflectance of planar silicon from 35% to below 0.5% over a broad wavelength range. Alternatively, nanocones made of TiO2 on silicon exhibit low reflectance (<3%) and improved transmittance into the substrate at the visible wavelength range. The measured optical properties concur with the simulation results. The versatility of the PS-b-PDMS templates was further utilized for nanopatterning materials such as silicon-on-insulator substrates, gallium arsenide, aluminum indium phosphide, and gallium nitride, which are important in electronics and photonics.

All-Metal Broadband Optical Absorbers Based on Block Copolymer Nanolithography.

The growing interest in solar energy during recent years has spurred on the development of high-efficiency optical absorbers using emerging concepts in plasmonics and metamaterials. Most absorber designs require patterning on a subwavelength scale, making large-scale fabrication expensive or impractical. This study presents an all-metal metasurface with tightly packed, sub-80 nm nanodomes fabricated by template-stripping thin gold films from reusable silicon templates. Subwavelength patterning was achieved via molecular self-assembly of block copolymers, which enables large-area, periodic patterning with nanometer precision. The proposed nanodome surface acts as an optical absorber capable of absorbing 97% of incident light in the visible range 320-650 nm, and still more than 90% at high incidence angles. We demonstrate both experimentally and theoretically that the absorption behavior of the thin film can be controlled by changing the size of the nanodomes, namely, the gap between the structures. The enhanced absorption of light is attributed to localized particle plasmon and gap plasmon resonances. This research provides a straightforward and cost-effective strategy to design and fabricate thin, large-area, light-absorbing coatings that can be transferred onto nearly any rigid or flexible substrate. The all-metal metasurfaces are a promising candidate for plasmon-induced hot electron generation for efficient solar energy conversion in photovoltaic and photocatalytic devices.

Directed self-assembly of a high-chi block copolymer for the fabrication of optical nanoresonators.

In this paper, we report on the fabrication of optical nanoresonators using block copolymer lithography. The nanostructured gratings or nanofins were fabricated using a silicon-containing block copolymer on a chromium coated silicon-on-insulator substrate. The etch resistance of the block copolymer template enables a unique patterning technique for high-aspect-ratio silicon nanofins. Integration of the directed self-assembly with nanoimprint lithography provides a well-aligned array of nanofins with a depth of ∼125 nm on a wafer scale. The developed nanopatterning method is an alternative to the previously reported nanopatterning techniques utilizing block copolymers. A dense array of sub-10 nm nanofins is used to realize a photonic guided-mode resonance filter. The nanostructured grating provides high sensitivity in refractive index sensing, as demonstrated by simulations and experiments in measuring varying contents of the tetrahydrofuran solvent.

Comparison of metal/polymer back reflectors with half-sphere, blazed, and pyramid gratings for light trapping in III-V solar cells.

We report on the fabrication of diffraction gratings for application as back contact reflectors. The gratings are designed for thin-film solar cells incorporating absorbers with bandgap slightly lower than GaAs, i.e. InAs quantum dot or GaInNAs solar cells. Light trapping in the solar cells enables the increase of the absorption leading to higher short circuit current densities and higher efficiencies. We study metal/polymer back reflectors with half-sphere, blazed, and pyramid gratings, which were fabricated either by photolithography or by nanoimprint lithography. The gratings are compared in terms of the total and the specular reflectance, which determine their diffraction capabilities, i.e. the feature responsible for increasing the absorption. The pyramid grating showed the highest diffuse reflection of light compared to the half-sphere structure and the blazed grating. The diffraction efficiency measurements were in agreement with the numerical simulations. The validated model enables designing such metal/polymer back reflectors for other type of solar cells by refining the optimal dimensions of the gratings for different wavelength ranges.

Guided-mode resonance gratings for enhanced mid-infrared absorption in quantum dot intermediate-band solar cells.

Achieving strong absorption of low-energy photons is one of the key issues to demonstrate quantum dot solar cells working in the intermediate band regime at practical concentration factors and operating temperatures. Guided-mode resonance effects may enable large enhancement of quantum dot intraband optical transitions. We propose quantum dot thin-film cells designed to have significant field waveguiding in the quantum dot stack region and patterned at the rear-side with a sub-wavelength diffraction grating. Remarkable increase of the optical path length at mid-infrared wavelengths is shown owing to guided-mode resonances. Design guidelines are presented for energy and strength of the second-photon absorption for III-V quantum dots, such as InAs/GaAs and GaSb/GaAs, whose intraband and intersubband transitions roughly extends over the 2 - 8 µm range. The proposed design can also be applied to quantum dot infrared detectors. Angle-selectivity is discussed in view of applications in concentrator photovoltaic systems and infrared imaging systems.

Ultra-large core birefringent Yb-doped tapered double clad fiber for high power amplifiers.

We present a birefringent Yb-doped tapered double-clad fiber with a record core diameter of 96 µm. An impressive gain of over 38 dB was demonstrated for linearly polarized CW and pulsed sources at a wavelength of 1040 nm. For the CW regime the output power was70 W. For a mode-locked fiber laser a pulse energy of 28 µJ with 292 kW peak power was reached at an average output power of 28 W for a 1 MHz repetition rate. The tapered double-clad fiber has a high value of polarization extinction ratio at 30 dB and is capable of delivering the linearly polarized diffraction-limited beam (M2 = 1.09).

Nonlinear imaging of nanostructures using beams with binary phase modulation.

We demonstrate nonlinear microscopy of oriented nanowires using excitation beams with binary phase modulation. A simple and intuitive optical scheme comprising a spatial light modulator gives us the possibility to control the phase across an incident Hermite-Gaussian beam of order (1,0) (HG10 mode). This technique allows us to gradually vary the spatial distribution of the longitudinal electric fields in the focal volume, as demonstrated by second-harmonic generation from vertically-aligned GaAs nanowires. These results open new opportunities for the full control of polarization in the focal volume to enhance light interaction with nanostructured materials.

Block Copolymer Patterning for Creating Porous Silicon Thin Films with Tunable Refractive Indices.

We investigated the use of block copolymer (BCP) self-assembly for tuning the optical properties of silicon. We fabricated porous silicon by etching a hexagonally ordered pore pattern onto the surface of silicon wafers using poly(styrene-2-vinylpyridine) to prepare the etch mask. Contrary to typical BCP lithography, we did not need to use a range of different polymers to vary the pore size. We used the dry etching time as a way to increase the pore diameter and thus the porosity. The optical properties of the fabricated porous thin films were characterized by two effective medium approximations. Both the volume-averaging theory and the 2D Maxwell-Garnett theory gave similar effective refractive index values, although the latter was more accurate in predicting the film porosity. The refractive indices of the produced thin films could be varied by controlling the porosity. A maximum decrease of 30% in the refractive index was observed at 34% porosity compared to bulk silicon. We also demonstrated over a 60% decrease in the reflectance of silicon at 500 nm wavelength. The presented BCP method can be used to tailor semiconductor and dielectric layers for photonic applications without the size limitations of conventional lithography or the unpredictability of other pore-forming fabrication methods.

Fabrication of Ion-Shaped Anisotropic Nanoparticles and their Orientational Imaging by Second-Harmonic Generation Microscopy.

Ion beam shaping is a novel and powerful tool to engineer nanocomposites with effective three-dimensional (3D) architectures. In particular, this technique offers the possibility to precisely control the size, shape and 3D orientation of metallic nanoparticles at the nanometer scale while keeping the particle volume constant. Here, we use swift heavy ions of xenon for irradiation in order to successfully fabricate nanocomposites consisting of anisotropic gold nanoparticle that are oriented in 3D and embedded in silica matrix. Furthermore, we investigate individual nanorods using a nonlinear optical microscope based on second-harmonic generation (SHG). A tightly focused linearly or radially-polarized laser beam is used to excite nanorods with different orientations. We demonstrate high sensitivity of the SHG response for these polarizations to the orientation of the nanorods. The SHG measurements are in excellent agreement with the results of numerical modeling based on the boundary element method.

Enhancement of second-harmonic generation from silicon nitride with gold gratings.

We report strong enhancement of second-harmonic generation in a hybrid nanostructure with gold gratings embedded in a silicon nitride film. Compared to a flat silicon nitride film, the enhancement factor can be as large as 102 to 103 for transverse magnetic and electric polarizations, respectively in good agreement with numerical results calculated using finite element method. For both polarizations, the enhancement arises from a resonance between the waveguide modes and grating.

Coating of gold nanoparticles made by pulsed laser ablation in liquids with silica shells by simultaneous chemical synthesis.

Coating of gold nanoparticles with silica shells by the well known Stöber-method requires the use of additional coupling agents to seed the growth of the shell as gold does not form a native oxide. Here we report a novel single-step process to create the gold nanoparticles directly into a mixture of tetraethyl orthosilicate and a catalyst by means of pulsed laser ablation in liquids. We observe that good silica shells are achieved only when all of the reagents are present during the production of the nanoparticles. Experiments with two different laser wavelengths: 515 nm and 1030 nm, show that the formation of the shell is efficient only with the laser wavelength close to the plasmon resonance of the gold nanoparticles. We propose a model indicating that the shell formation is initiated by laser-induced heating of the particles.

Broadband infrared mirror using guided-mode resonance in a subwavelength germanium grating.

We demonstrate a broadband mirror for the IR wavelength region comprising a subwavelength grating made of germanium. We design and optimize the guided-mode resonances in the structure for TM-polarized incident light by rigorous electromagnetic simulations. The grating structure is realized by nanoimprint lithography and dry etching. The reflectivity of the mirror is over 95% for the wavelength range between 2245 and 3080nm.

How Grids are perceived in healthcare and the public service sector.

Computational and data grids have been developed to manage large amounts of data produced in scientific collaborations. While the developed technologies could be employed to help the daily work in the public sector and in healthcare, their wide adaptation has not been seen, yet. In this paper we present a survey, which we conducted to find out how the decision makers and system specialists in the public service sector see the role of Grid technologies in their future work. The respondents of the survey work as decision makers and systems specialists in the healthcare and the public services domain in Switzerland.

Narrow linewidth templates for nanoimprint lithography utilizing conformal deposition.

Nanoimprint lithography has the potential to cost efficiently realize patterns with extremely narrow linewidth over a large area. A significant challenge to achieving this target is the fabrication of nanoimprint templates. The cost and writing time of conventional electron beam lithography for direct writing of the templates rapidly increases as the patterned area increases and the linewidth decreases. We have developed a novel process for creating narrow linewidth nanopatterns. This process is based on conformal deposition of thin films on seed nanopatterns. We have demonstrated the process by fabricating nanosized loops and lines. The linewidth of the structures can be tuned precisely, and in our experiments it could be reduced to 20 nm. The closed loop structures are interesting, since this geometry is crucially important in many leading edge research fields such as negative refractive index materials, ultrahigh density memory applications and quantum rings. The fabricated template was subsequently used as a template in soft-stamp UV nanoimprint lithography to successfully replicate the structures in UV-curable resist.