Design and experimental validation of a finite-size labyrinthine metamaterial for vibro-acoustics: enabling upscaling towards large-scale structures.

In this article, we present the design and experimental validation of a labyrinthine metamaterial for vibro-acoustic applications. Based on a two-dimensional unit cell, different designs of finite-size metamaterial specimens in a sandwich configuration including two plates are proposed. The design phase includes an optimization based on Bloch-Floquet analysis with the aims of maximizing the band gap and extruding the specimens in the third dimension while keeping the absorption properties almost unaffected. By manufacturing and experimentally testing finite-sized specimens, we assess their capacity to mitigate vibrations in vibro-impact tests. The experiments confirm a band gap in the low- to mid-frequency range. Numerical models are employed to validate the experiments and to examine additional vibro-acoustic load cases. The metamaterial's performances are compared with benchmark solutions, usually employed for noise and vibration mitigation, showing a comparable efficacy in the band gap region. To eventually improve the metamaterial's performance, we optimize its interaction with the air and test different types of connections between the metamaterial and the homogeneous plates. This finally leads to metamaterial samples largely exceeding the benchmark performances in the band gap region and reveals the potential of interfaces for performance optimization of composed structures.This article is part of the theme issue 'Current developments in elastic and acoustic metamaterials science (Part 1)'.

Incidence and risk factors of hypoxaemia after preoxygenation at induction of anaesthesia.

BACKGROUND: The incidence of hypoxaemia related to airway management is still a matter of concern. Our aim was to determine the factors that contribute to hypoxaemia during induction of anaesthesia after a standardised preoxygenation procedure. METHODS: The study was a multicentre and prospective observational trial. It evaluated the incidence of hypoxaemia at induction of anaesthesia in adult patients. The primary endpoint was the incidence of hypoxaemia defined as pulse oximetry of arterial oxyhaemoglobin saturation (SpO2) <95%. RESULTS: Of 2398 patients, hypoxaemia was observed in 158 (6.6%). We identified five preoperative independent risk factors: chronic obstructive pulmonary disease, hypertension, anticipated difficult mask ventilation and difficult tracheal intubation, and emergency surgery. There were also three pre-induction independent risk factors: difficult preoxygenation, difficult mask ventilation, and difficult tracheal intubation. We found a high negative predictive value of preoperative risk factors for difficult mask ventilation of 0.96 (0.95-0.96), and for difficult tracheal intubation (0.95 [0.94-0.96]). A total of 723 patients (30%) experienced difficult preoxygenation (FeO2 <90% at the end of preoxygenation). Male sex, chronic obstructive pulmonary disease, hypertension, emergency surgery, and predictable difficult mask ventilation were independent patient risk factors for difficult preoxygenation. CONCLUSIONS: Difficult mask ventilation and difficult tracheal intubation are risk factors for hypoxaemia at induction of general anaesthesia. Difficult preoxygenation was observed in 30% of patients and was also identified as a risk factor for hypoxaemia. This suggests that techniques improving preoxygenation should be implemented in daily practice.

Case-control study found that primary language disorders were associated with screen exposure.

AIM: We explored the associations between childhood exposure to screens, including televisions, computers, game consoles, tablets and smartphones and primary language disorders. METHODS: This multi-centre case-control study comprised 167 children aged 3.5-6.5 years, who were born in 2010-2012 and diagnosed with primary language disorders, and 109 matched controls without language disorders. Questionnaires were completed by their parents who were recruited by 16 family doctors and 27 speech and language therapists in the Ille-et-Vilaine region of France. The data were analysed using a multivariate logistic regression model and presented as adjusted odds ratios (aOR) and 95% confidence intervals (95% CI). RESULTS: We found that cases (44.3%) and controls (22.0%) exposed to screens in the morning before nursery or primary school were three times more likely to develop primary language disorders (aOR 3.40, 95% CI 1.60-7.23). When this risk was combined with rarely or never discussing screen content with their parents (aOR 2.14, 95% CI 1.01-4.54) they were six times more likely to have language problems (aOR 5.86, 95% CI 1.44-23.95). CONCLUSION: Being exposed to screens in the morning before school, and rarely or never discussing screen content with parents, meant children were six times more likely to develop primary language disorders.

Nurses' and physicians' approaches to delirium management in the intensive care unit: A focus group investigation.

BACKGROUND: Delirium in the intensive care unit (ICU) is common, but reliable evidence-based recommendations are still limited. OBJECTIVES: The aim of our study was to explore nurses' and physicians' experiences and approaches to ICU delirium management. METHOD: Our study had a qualitative multicentre design using interdisciplinary focus groups and framework analysis. Participants were strategically selected to include nurses and physicians with experience in delirium management at five ICUs in four out of five regions in Denmark. RESULTS: We conducted eight focus group interviews with 24 nurses and 15 physicians; median ICU experience was 9 years (range 1-35). The main issues identified were (1) the decision to treat or not to treat ICU delirium based on delirium phenotype, (2) the decision to act based on experience or evidence, and (3) the decision to intervene using nursing care or medications. ICU delirium was treated with pharmacological interventions in patients with signs of agitation, hallucinations, and sleep deprivation. The first choice of agent was haloperidol or olanzapine. Agitated and combative patients received benzodiazepines, propofol, or dexmedetomidine. Calm delirious patients were managed with non-pharmacological solutions. Physicians recommended pro re nata (PRN) orders to prevent over medication, whereas nurses opposed PRN orders with the fear that it would increase their responsibilities. CONCLUSION: Our study described an algorithm of contemporary delirium management in Danish ICUs based on qualitative inquiry. When evidence-based solutions are unclear, nurses and physicians rely on personal experience, collective experience, and best available evidence to determine which patients to treat and what methods to use to treat ICU delirium. Delirium management still needs clear objectives and guidelines with evidence-based recommendations for first-line treatment and subsequent treatment options.

Haloperidol for delirium in critically ill patients - protocol for a systematic review.

BACKGROUND: In the intensive care unit, the prevalence of delirium is high. Delirium has been associated with morbidity and mortality including more ventilator days, longer intensive care unit stay, increased long-term mortality, and cognitive impairment. Thus, the burden of delirium for patients, relatives, and societies is considerable. The objective of this systematic review was to critically access the evidence of randomised clinical trials on the effects of haloperidol vs. placebo or any other agents for delirium in critically ill patients. METHODS: We will search for randomised clinical trials in the following databases: Cochrane Library, MEDLINE, EMBASE, Science Citation Index, BIOSIS, Cumulative Index to Nursing and Allied Health Literature, Latin American and Caribbean Health Sciences Literature, and Allied and Complementary Medicine Database. Two authors will independently screen and select references for inclusion using Covidence, extract data and assess the methodological quality of the included randomised clinical trials using the Cochrane risk of bias tool. Any disagreement will be resolved by consensus. We will analyse the extracted data using Review Manager, STATA 15, and Trial Sequential. ANALYSIS: The aim of this study was to assess the quality of the evidence, we will create a 'Summary of Findings' table containing our primary and secondary outcomes using the GRADE assessment. DISCUSSION: Our ambition with this systematic review is to provide reliable and powered evidence to better inform decision makers on the use of or future trials with haloperidol for the management of delirium in critically ill patients.

Development and internal validation of the Simplified Mortality Score for the Intensive Care Unit (SMS-ICU).

BACKGROUND: Intensive care unit (ICU) mortality prediction scores deteriorate over time, and their complexity decreases clinical applicability and commonly causes problems with missing data. We aimed to develop and internally validate a new and simple score that predicts 90-day mortality in adults upon acute admission to the ICU: the Simplified Mortality Score for the Intensive Care Unit (SMS-ICU). METHODS: We used data from an international cohort of 2139 patients acutely admitted to the ICU and 1947 ICU patients with severe sepsis/septic shock from 2009 to 2016. We performed multiple imputations for missing data and used binary logistic regression analysis with variable selection by backward elimination, followed by conversion to a simple point-based score. We assessed the apparent performance and validated the score internally using bootstrapping to present optimism-corrected performance estimates. RESULTS: The SMS-ICU comprises seven variables available in 99.5% of the patients: two numeric variables: age and lowest systolic blood pressure, and five dichotomous variables: haematologic malignancy/metastatic cancer, acute surgical admission and use of vasopressors/inotropes, respiratory support and renal replacement therapy. Discrimination (area under the receiver operating characteristic curve) was 0.72 (95% CI: 0.71-0.74), overall performance (Nagelkerke's R2 ) was 0.19 and calibration (intercept and slope) was 0.00 and 0.99, respectively. Optimism-corrected performance was similar to apparent performance. CONCLUSIONS: The SMS-ICU predicted 90-day mortality with reasonable and stable performance. If performance remains adequate after external validation, the SMS-ICU could prove a valuable tool for ICU clinicians and researchers because of its simplicity and expected very low number of missing values.

Validated chromatographic method for the simultaneous determination of eight drugs (morphine, ropivacaine, bupivacaine, baclofen, clonidine, sufentanil, fentanyl and ziconotide) for intrathecal analgesia.

Intrathecal analgesia has increased over the past two decades in various indications: chronic refractory pain from cancerous or non-cancerous origins, spasticity. These different indications involve the use of different molecules alone or in combination such as morphine, ropivacaine, bupivacaine, fentanyl, sufentanil, clonidine, baclofen and ziconotide. Pump refills are prepared at the pharmacy under a laminar flow hood. An analytical control should be carried out before release of the preparation. A new method of analytical control by chromatography has been developed and validated according to the International Conference on Harmonization guideline in order to secure the production process.

Direct and indirect genetic effects of sex-specific mitonuclear epistasis on reproductive ageing.

Mitochondria are involved in ageing and their function requires coordinated action of both mitochondrial and nuclear genes. Epistasis between the two genomes can influence lifespan but whether this also holds for reproductive senescence is unclear. Maternal inheritance of mitochondria predicts sex differences in the efficacy of selection on mitonuclear genotypes that should result in differences between females and males in mitochondrial genetic effects. Mitonuclear genotype of a focal individual may also indirectly affect trait expression in the mating partner. We tested these predictions in the seed beetle Callosobruchus maculatus, using introgression lines harbouring distinct mitonuclear genotypes. Our results reveal both direct and indirect sex-specific effects of mitonuclear epistasis on reproductive ageing. Females harbouring coadapted mitonuclear genotypes showed higher lifetime fecundity due to slower senescence relative to novel mitonuclear combinations. We found no evidence for mitonuclear coadaptation in males. Mitonuclear epistasis not only affected age-specific ejaculate weight, but also influenced male age-dependent indirect effects on traits expressed by their female partners (fecundity, egg size, longevity). These results demonstrate important consequences of sex-specific mitonuclear epistasis for both mating partners, consistent with a role for mitonuclear genetic constraints upon sex-specific adaptive evolution.

Frequency of the Val1016Ile mutation on the kdr gene in Aedes aegypti (Diptera: Culicidae) in south Brazil.

Recently, the number of Aedes aegypti foci has increased in west of Santa Catarina, south Brazil, which has increased concern regarding mosquito-borne disease outbreaks such as dengue fever, Zika virus, and chikungunya. Therefore, it is important to monitor genetic resistance to insecticides through "knockdown resistance". Homozygosity (Ile/Ile) at position 1016 in the coding region of a voltage-dependent sodium channel gene (Nav) may induce resistance to pyrethroid insecticides. We evaluated the frequency of these alleles in A. aegypti in west Santa Catarina. In total, 349 specimens were obtained from the microregions of Joaçaba (31), Concórdia (35), Chapecó (154), and São Miguel do Oeste (129). We found that 109 individuals (31.0%) were homozygous for Val/Val, 102 (29.0%) were heterozygous for Val/Ile, and 138 (40.0%) were homozygous for Ile/Ile. The allele frequencies were similar for Val (0.455) and Ile (0.545). Joaçaba and Concórdia had the highest mutant allele frequencies (0.825 and 0.685, respectively). Therefore, these populations should be monitored for increases in pyrethroid resistance. The São Miguel do Oeste and Chapecó populations had similar frequencies of Val and Ile and were not in Hardy-Weinberg equilibrium, suggesting that a selection pressure or other evolutionary force has occurred. In conclusion, the observed frequency of Ile/Ile homozygous individuals in the region studied requires attention, because the implementation of controls using pyrethroid may increase the frequency of the mutant allele through the selection of resistant populations.

Enhanced electro-optical lithium niobate photonic crystal wire waveguide on a smart-cut thin film.

We report an electro-optically tunable photonic crystal linear cavity etched on a 200 nm lithium niobate waveguide ridge. The photonic crystal cavity and the ridge are both fabricated on a 1 µm thin film of lithium niobate obtained by smart-cut technology. The photonic crystal, of area 4x0.8 µm2, has been engineered to work in a slow light configuration so that the electro-optic effect is 20 times more important than in bulk material.

6-micron interaction length electro-optic modulation based on lithium niobate photonic crystal cavity.

We report on electro-optic modulation using a Lithium Niobate (LN) Photonic Crystal (PC) cavity structure. The compact device (6 µm in length) consists of a 2D photonic crystal cavity made on an Annealed Proton Exchange (APE) LN waveguide with vertical deposited electrodes. Experimental results show a tunability of 0.6 nm/V. This compact design opens a way towards micro and nano-scale tunable photonic devices with low driving electrical power.

The cytotoxic effect of combined hyperthermia and taxane chemotherapy on ovarian cancer cells: results of an in vitro study.

PURPOSE: Hyperthermic intraperitoneal chemotherapy (HIPEC) is under continuous evaluation as a potential treatment for ovarian cancer. The purpose of this study was to evaluate the effect of chemotherapy, drug concentration and temperature. MATERIALS AND METHODS: We examined the combined effects of hyperthermia and taxane chemotherapy on the clonogenic survival of the human ovarian carcinoma SHIN-3 cell line in vitro. RESULTS: When hyperthermia was combined with chemotherapy, the median lethal dose (LD50) was equivalent regardless of the duration of exposure, and was independent of the exposure temperature. Taxanes showed a similar LD50 over the temperature range tested. CONCLUSIONS: In our study, hyperthermia does not increase the cytotoxic effects of taxanes, at least for the concentrations and durations tested.

Ellipsometric and Rutherford Back scattering Spectrometry studies of SiO(X)N(Y) films elaborated by plasma-enhanced chemical vapour deposition technique.

Silicon oxynitride (SiO(X)N(Y)) thin films were deposited by plasma-enhanced chemical vapour deposition technique (PECVD) from silane (SiH4), nitrous oxide (N2O), ammonia (NH3) and nitrogen (N2) mixture. Spectroscopic ellipsometry (SE), in the range of wavelengths 450-900 nm, was used to define the film thickness and therefore the deposition rate, as well as the refractive index as a function of the N2O gaseous flow. While considering the (Si3N4, SiO2, H2 or void) heterogeneous mixture, Maxwell Garnett (MG) theory allows to fit the SE measurements and to define the volume fraction of the different phases. Finally, Rutherford Backscattering Spectrometry (RBS) results showed that x = O/Si ratio increases gradually with increasing the N2O flow, allowing the correlation of the SiO(X)N(Y) films main parameters.

Active acoustical impedance using distributed electrodynamical transducers.

New miniaturization and integration capabilities available from emerging microelectromechanical system (MEMS) technology will allow silicon-based artificial skins involving thousands of elementary actuators to be developed in the near future. SMART structures combining large arrays of elementary motion pixels coated with macroscopic components are thus being studied so that fundamental properties such as shape, stiffness, and even reflectivity of light and sound could be dynamically adjusted. This paper investigates the acoustic impedance capabilities of a set of distributed transducers connected with a suitable controlling strategy. Research in this domain aims at designing integrated active interfaces with a desired acoustical impedance for reaching an appropriate global acoustical behavior. This generic problem is intrinsically connected with the control of multiphysical systems based on partial differential equations (PDEs) and with the notion of multiscaled physics when a dense array of electromechanical systems (or MEMS) is considered. By using specific techniques based on PDE control theory, a simple boundary control equation capable of annihilating the wave reflections has been built. The obtained strategy is also discretized as a low order time-space operator for experimental implementation by using a dense network of interlaced microphones and loudspeakers. The resulting quasicollocated architecture guarantees robustness and stability margins. This paper aims at showing how a well controlled semidistributed active skin can substantially modify the sound transmissibility or reflectivity of the corresponding homogeneous passive interface. In Sec. IV, numerical and experimental results demonstrate the capabilities of such a method for controlling sound propagation in ducts. Finally, in Sec. V, an energy-based comparison with a classical open-loop strategy underlines the system's efficiency.

[How to confirm acute fatty liver of pregnancy in case of emergency]. / Comment confirmer le diagnostic de stéatose hépatique aiguë gravidique en urgence?

Acute fatty liver of pregnancy (AFLP) is a rare disease of which prognosis could be adverse if diagnosis is delayed. Certain diagnosis is sometimes made complex because of undercurrent symptoms with pre-eclampsia or hemolysis, elevated liver enzyme, low platelet (HELLP) syndrome. Several reports announce an increase of incidence and illustrate cases confirmed by non-invasive methods. They permit early diagnosis and improve morbidity and mortality. Reviewing seven of the most important series of AFLP, we demonstrate how to use ultrasonography or computed tomography scan to confirm AFLP. However, liver biopsy should be realised after delivery in case of uncertain diagnosis.

Development of an ICU discharge instrument predicting psychological morbidity: a multinational study.

PURPOSE: To develop an instrument for use at ICU discharge for prediction of psychological problems in ICU survivors. METHODS: Multinational, prospective cohort study in ten general ICUs in secondary and tertiary care hospitals in Sweden, Denmark and the Netherlands. Adult patients with an ICU stay ≥ 12 h were eligible for inclusion. Patients in need of neurointensive care, with documented cognitive impairment, unable to communicate in the local language, without a home address or with more than one limitation of therapy were excluded. Primary outcome was psychological morbidity 3 months after ICU discharge, defined as Hospital Anxiety and Depression Scale (HADS) subscale score ≥ 11 or Post-traumatic Stress Symptoms Checklist-14 (PTSS-14) part B score > 45. RESULTS: A total of 572 patients were included and 78% of patients alive at follow-up responded to questionnaires. Twenty percent were classified as having psychological problems post-ICU. Of 18 potential risk factors, four were included in the final prediction model after multivariable logistic regression analysis: symptoms of depression [odds ratio (OR) 1.29, 95% confidence interval (CI) 1.10-1.50], traumatic memories (OR 1.44, 95% CI 1.13-1.82), lack of social support (OR 3.28, 95% CI 1.47-7.32) and age (age-dependent OR, peak risk at age 49-65 years). The area under the receiver operating characteristics curve (AUC) for the instrument was 0.76 (95% CI 0.70-0.81). CONCLUSIONS: We developed an instrument to predict individual patients' risk for psychological problems 3 months post-ICU, http://www.imm.ki.se/biostatistics/calculators/psychmorb/ . The instrument can be used for triage of patients for psychological ICU follow-up. TRIAL REGISTRATION: The study was registered at clinicaltrials.gov, NCT02679157.

Direct observation of dynamic modes excited in a magnetic insulator by pure spin current.

Excitation of magnetization dynamics by pure spin currents has been recently recognized as an enabling mechanism for spintronics and magnonics, which allows implementation of spin-torque devices based on low-damping insulating magnetic materials. Here we report the first spatially-resolved study of the dynamic modes excited by pure spin current in nanometer-thick microscopic insulating Yttrium Iron Garnet disks. We show that these modes exhibit nonlinear self-broadening preventing the formation of the self-localized magnetic bullet, which plays a crucial role in the stabilization of the single-mode magnetization oscillations in all-metallic systems. This peculiarity associated with the efficient nonlinear mode coupling in low-damping materials can be among the main factors governing the interaction of pure spin currents with the dynamic magnetization in high-quality magnetic insulators.

Generation of coherent spin-wave modes in yttrium iron garnet microdiscs by spin-orbit torque.

In recent years, spin-orbit effects have been widely used to produce and detect spin currents in spintronic devices. The peculiar symmetry of the spin Hall effect allows creation of a spin accumulation at the interface between a metal with strong spin-orbit interaction and a magnetic insulator, which can lead to a net pure spin current flowing from the metal into the insulator. This spin current applies a torque on the magnetization, which can eventually be driven into steady motion. Tailoring this experiment on extended films has proven to be elusive, probably due to mode competition. This requires the reduction of both the thickness and lateral size to reach full damping compensation. Here we show clear evidence of coherent spin-orbit torque-induced auto-oscillation in micron-sized yttrium iron garnet discs of thickness 20 nm. Our results emphasize the key role of quasi-degenerate spin-wave modes, which increase the threshold current.

[Preliminary results of an herpetology investigation in sugar cane plantation in Democratic Republic of Congo]. / Résultats préliminaires d'une enquête herpétologique en plantation de cannes à sucre en République Démocratique du Congo.

Out of the 3,000 species of snakes described in the world, 163 are currently known from D.R. of Congo. We performed a systematic survey in sugar-cane plantations of the Sugar Company of Kwilu-Ngongo (Bas-Congo), located at 160 km South-West from Kinshasa and exploiting nearly 10,000 ha. The plantation is divided into 3 sectors in the middle of which we deposited barrels filled of formaldehyde. All the employees of the Sugar Company of Kwilu-Ngongo were requested to collect encountered snakes and put them in the nearest barrel. Between August 9th and September 21st, 2004, we collected 36 snakes in two different sites, revealing the presence of 3 families and 12 species. The most abundant species in Causus maculatus (47% in the first site--Point 8--and 29% in the second site--Point 13). The most poisonous and dangerous species were captured only in the first site--point 8, and were Dendroaspis jamesoni and Naja melanoleuca, both young.

[Consequences of smoking on fetal development and risk of intra-uterine growth retardation or in utero fetal death]. / Conséquences du tabagisme sur le développement foetal et le risque de retard de croissance intra-utérin ou de mort foetale in utero.

Active and passive smoking constitutes one of the most serious public health problems due to the deleterious effect on the expected infant and the mother. These effects are dose dependent as illustrated by intra-uterine growth retardation, where the effect worsens with duration of smoking during pregnancy, and also by other conditions such as abrutio placentae or placenta praevia, premature rupture of the membranes and preterm birth, where the risk is multiplied by two (or even three)! In utero death is the ultimate sanction. Studies on the consequences of maternal smoking on fetal development have demonstrated the cardiovascular effect (CO and nicotine) and the respiratory effect (CO) which can be aggravated after birth by passive smoking. Teratogenic and cancerogenic effects have also been clearly demonstrated. Maternal smoking would also affect fetal brain development with negative effects on the major neurotransmitter systems (domaminergic, serotinergic, noradrenergic) and on the development of key structures such as the prefrontal cortex, certain limbic structures including the hippocampus and other structures implicated in motor function such as the ventral striatum. These development anomalies of the brain could give rise, after birth, to psychological, behavioral, attention and cognitive disorders, further arguments in favor of an effective anti-smoking policy including appropriate care for smoking pregnant mothers in both hospital and outpatient settings.