Dual-gated bilayer graphene hot electron bolometer

Detection of infrared light is central to diverse applications in security, medicine, astronomy, materials science, and biology. Often different materials and detection mechanisms are employed to optimize performance in different spectral ranges. Graphene is a unique material with strong, nearly frequency-independent light-matter interaction from far infrared to ultraviolet, with potential for broadband photonics applications. Moreover, graphene's small electron-phonon coupling suggests that hot-electron effects may be exploited at relatively high temperatures for fast and highly sensitive detectors in which light energy heats only the small-specific-heat electronic system. Here we demonstrate such a hot-electron bolometer using bilayer graphene that is dual-gated to create a tunable bandgap and electron-temperature-dependent conductivity. The measured large electron-phonon heat resistance is in good agreement with theoretical estimates in magnitude and temperature dependence, and enables our graphene bolometer operating at a temperature of 5 K to have a low noise equivalent power (33 fW/Hz1/2). We employ a pump-probe technique to directly measure the intrinsic speed of our device, >1 GHz at 10 K.Comment: 5 figure

Exploring Barriers and Opportunities in Adopting Crowdsourcing Based New Product Development in Manufacturing SMEs

Crowdsourcing is an innovative business practice of obtaining needed services, ideas, or content or even funds by soliciting contributions from a large group of people (the ‘Crowd’). The potential benefits of utilizing crowdsourcing in product design are well-documented, but little research exists on what are the barriers and opportunities in adopting crowdsourcing in new product development (NPD) of manufacturing SMEs. In order to answer the above questions, a Proof of Market study is carried out on crowdsourcing-based product design under an Innovate UK funded Smart project, which aims at identifying the needs, challenges and future development opportunities associated with adopting crowdsourcing strategies for NPD. The research findings from this study are reported here and can be used to guide future development of crowdsourcing-based collaborative design methods and tools and provide some practical references for industry to adopt this new and emerging collaborative design method in their business

Effects of hospital facilities on patient outcomes after cancer surgery: an international, prospective, observational study

Background Early death after cancer surgery is higher in low-income and middle-income countries (LMICs) compared with in high-income countries, yet the impact of facility characteristics on early postoperative outcomes is unknown. The aim of this study was to examine the association between hospital infrastructure, resource availability, and processes on early outcomes after cancer surgery worldwide.Methods A multimethods analysis was performed as part of the GlobalSurg 3 study-a multicentre, international, prospective cohort study of patients who had surgery for breast, colorectal, or gastric cancer. The primary outcomes were 30-day mortality and 30-day major complication rates. Potentially beneficial hospital facilities were identified by variable selection to select those associated with 30-day mortality. Adjusted outcomes were determined using generalised estimating equations to account for patient characteristics and country-income group, with population stratification by hospital.Findings Between April 1, 2018, and April 23, 2019, facility-level data were collected for 9685 patients across 238 hospitals in 66 countries (91 hospitals in 20 high-income countries; 57 hospitals in 19 upper-middle-income countries; and 90 hospitals in 27 low-income to lower-middle-income countries). The availability of five hospital facilities was inversely associated with mortality: ultrasound, CT scanner, critical care unit, opioid analgesia, and oncologist. After adjustment for case-mix and country income group, hospitals with three or fewer of these facilities (62 hospitals, 1294 patients) had higher mortality compared with those with four or five (adjusted odds ratio [OR] 3.85 [95% CI 2.58-5.75]; p<0.0001), with excess mortality predominantly explained by a limited capacity to rescue following the development of major complications (63.0% vs 82.7%; OR 0.35 [0.23-0.53]; p<0.0001). Across LMICs, improvements in hospital facilities would prevent one to three deaths for every 100 patients undergoing surgery for cancer.Interpretation Hospitals with higher levels of infrastructure and resources have better outcomes after cancer surgery, independent of country income. Without urgent strengthening of hospital infrastructure and resources, the reductions in cancer-associated mortality associated with improved access will not be realised

Origin of Axial and Radial Expansions in Carbon Nanotubes Revealed by Ultrafast Diffraction and Spectroscopy

The coupling between electronic and nuclear degrees of freedom in low-dimensional, nanoscale systems plays a fundamental role in shaping many of their properties. Here, we report the disentanglement of axial and radial expansions of carbon nanotubes, and the direct role of electronic and vibrational excitations in determining such expansions. With subpicosecond and subpicometer resolutions, structural dynamics were explored by monitoring changes of the electron diffraction following an ultrafast optical excitation, whereas the transient behavior of the charge distribution was probed by time-resolved, electron-energy-loss spectroscopy. Our experimental results, and supporting density functional theory calculations, indicate that a population of the excited carriers in the antibonding orbitals of the nanotube walls drives a transient axial deformation in ∼1 ps; this deformation relaxes on a much longer time scale, 17 ps, by nonradiative decay. The electron-driven expansion is distinct from the phonon-driven dynamics observed along the radial direction, using the characteristic Bragg reflections; it occurs in 5 ps. These findings reveal the nonequilibrium distortion of the unit cell at early times and the role of the electron(phonon)-induced stress in the lattice dynamics of one-dimensional nanostructures

VP35.11: Fetal growth prescriptive charts evaluation: a systematic review

International audienc

Perinatal outcome of appropriate-weight fetuses with decelerating growth

Introduction: To assess the perinatal outcome of fetuses dropping by ≥50 estimated fetal weight (EFW) centiles between the second and third trimester. Methods: Singleton pregnancies progressing after 32 + 0 weeks, who had their second- and third-trimester scans at our institutions were enrolled in the study. The perinatal outcome of AGA fetuses crossing more than 50 centiles was compared to that of fetuses with FGR, small for gestational age (SGA) and nondecelerating appropriate for gestational age (AGA). The primary perinatal outcomes were perinatal death, neonatal intensive care (NICU) admission and emergency cesarean section (CS). The rates of these outcomes were compared between the four groups and regression analysis was performed to account for maternal and fetal confounders. Results: Our analysis included 4394 cases. Compared to nondecelerating SGA, fetuses crossing ≥50 centiles had higher rates of NICU admission (odds ratio [OR] 1.8, 95% confidence interval [CI] CI 1.1–3.1) and perinatal death (OR 3.8, 95%CI 1.3–11.4). Regression analysis showed that significant independent predictors for NICU admission included maternal age, gestational age at birth and FGR (area under the curve [AUC] 0.851), whereas significant predictors for perinatal death included maternal age, gestational age at birth, decelerating growth ≥50 centiles, conception through ART and third-trimester CPR centile (AUC 0.801). Conclusion: AGA fetuses that cross >50 EFW centiles between the second and third trimester are at increased risk of adverse perinatal outcome and it seems advisable that they are followed up as typical FGR cases. © 2019 Informa UK Limited, trading as Taylor & Francis Group

Prevention of gestational diabetes mellitus in overweight or obese pregnant women: A network meta-analysis

Aims: Several interventions have been implemented to prevent the development of gestational diabetes mellitus (GDM) in obese pregnant women, including physical exercise programs, and administration of metformin, vitamin D and probiotics. The aim of this network meta‐analysis was to compare the efficiency of these interventions and identify the optimal. Materials: A network meta-analysis of randomized trials was performed comparing the different interventions for the development of GDM in overweight or obese women, either to each other or placebo/no intervention. A search was conducted in four electronic databases and grey literature sources. The primary outcome was the development of GDM; secondary outcomes were other complications of pregnancy. Results: The meta-analysis included 23 studies (4237 participants). None of the interventions was superior compared with placebo/no intervention for the prevention of GDM. Metformin and physical exercise were superior to placebo/no intervention for gestational weight gain (MD −1.21, 95% CI −2.14 to −0.28 and MD −0.96, 95% CI −1.69 to −0.22, respectively). Metformin was superior to placebo/no intervention for caesarean sections and admission to NICU. Conclusions: Interventions aiming to prevent the development of GDM in overweight/obese women are not effective, when applied during pregnancy. © 2019 Elsevier B.V

The effect of dietary supplements on oxidative stress in pregnant women with gestational diabetes mellitus: A network meta-analysis

Background: Gestational diabetes mellitus (GDM) exacerbates the oxidative stress status of the pregnant women. Τo improve the oxidative stress status, several therapeutic interventions have been suggested. The aim of this network meta-analysis is to assess the effect of different dietary supplements on the oxidative stress status in pregnant women with GDM. Methods: A network meta-analysis of randomized control trials was performed comparing the changes delta (Δ) in total antioxidant capacity (TAC) and concentration of malondialdehyde (MDA) as primary outcomes, following different therapeutic interventions with dietary supplements in pregnant women with GDM. Four electronic databases and grey literature sources were searched. The secondary outcomes were other markers of oxidative stress. Results: The meta-analysis included 16 studies of 1173 women with GDM. Regarding ΔTAC: probiotics and omega-3 with vitamin E were superior to placebo/no intervention. Regarding ΔMDA: vitamin D with calcium, omega-3, vitamin D, omega-3 with vitamin E, magnesium with zinc and calcium, and probiotics were superior to placebo/no intervention. Conclusions: Administration of dietary supplements in women with GDM can be helpful in limiting the oxidative stress which develop in these pregnancies. © 2021 by the authors. Licensee MDPI, Basel, Switzerland