When high work engagement is negative for family tasks: mechanisms and boundary conditions.

Background: Typically, work engagement is positively related to beneficial job outcomes. Earlier studies, however, revealed a "dark side" of work engagement showing negative effects such as more work-family conflict. Using a resource perspective, our study seeks to better understand why and when these negative effects of work engagement occur. Specifically, we test a new model in which the relationship of work engagement with work-family conflict is mediated by organizational citizenship behavior (OCB) and work rumination. Moreover, we argue that employees' resource-building strategies (i.e., job crafting) and resource levels (i.e., psychological capital) buffer resource depletion due to high work engagement. Methods: We tested our assumptions in a field study that involved data collected on three measurement points with 523 employees from Nigeria. The measures consist of Utrecht Work Engagement Scale, Organizational Citizenship Behavior Scale, Work Rumination Scale, Psychological Capital Scale, Job Crafting Measure, Work-family Conflict Scale, and demographic variables. Structural Equation Modeling (SEM) was used to test the hypotheses. Results and discussion: Results from latent structure equation modelling confirm that work rumination mediates the positive relationship between work engagement and work-family conflict. Additionally, our findings suggest that behavioral engagement (i.e.,OCB) and work rumination mediate the relationship between work engagement and work-family conflict. Moreover, psychological capital mitigated the relationships of work engagement with work rumination, but not job crafting. Our study helps to better understand the "dark side" of work engagement and offers implications on how to mitigate its detrimental relationship with work-family conflict.

Birth weight and gestational age distributions in a rural Kenyan population.

BACKGROUND: With the increased availability of access to prenatal ultrasound in low/middle-income countries, there is opportunity to better characterize the association between fetal growth and birth weight across global settings. This is important, as fetal growth curves and birthweight charts are often used as proxy health indicators. As part of a randomized control trial, in which ultrasonography was utilized to establish accurate gestational age of pregnancies, we explored the association between gestational age and birthweight among a cohort in Western Kenya, then compared our results to data reported by the INTERGROWTH-21st study. METHODS: This study was conducted in 8 geographical clusters across 3 counties in Western Kenya. Eligible subjects were nulliparous women carrying singleton pregnancies. An early ultrasound was performed between 6 + 0/7 and 13 + 6/7 weeks gestational age. At birth, infants were weighed on platform scales provided either by the study team (community births), or the Government of Kenya (public health facilities). The 10th, 25th, median, 75th, and 90th BW percentiles for 36 to 42 weeks gestation were determined; resulting percentile points were plotted, and curves determined using a cubic spline technique. A signed rank test was used to quantify the comparison of the percentiles generated in the rural Kenyan sample with those of the INTERGROWTH-21st study. RESULTS: A total of 1291 infants (of 1408 pregnant women randomized) were included. Ninety-three infants did not have a measured birth weight. The majority of these were due to miscarriage (n = 49) or stillbirth (n = 27). No significant differences were found between subjects who were lost to follow-up. Signed rank comparisons of the observed median of the Western Kenya data at 10th, 50th, and 90th birthweight percentiles, as compared to medians reported in the INTERGROWTH-21st distributions, revealed close alignment between the two datasets, with significant differences at 36 and 37 weeks. Limitations of the current study include small sample size, and detection of potential digit preference bias. CONCLUSIONS: A comparison of birthweight percentiles by gestational age estimation, among a sample of infants from rural Kenya, revealed slight differences as compared to those from the global population (INTERGROWTH-21st). TRIAL REGISTRATION: This is a single site sub-study of data collected in conjunction with the Aspirin Supplementation for Pregnancy Indicated Risk Reduction In Nulliparas (ASPIRIN) Trial, which is listed at  ClinicalTrials.gov ,  NCT02409680 (07/04/2015).

A sacrificial magnet concept for field dependent surface science studies.

We demonstrate a straightforward approach to integrating a magnetic field into a low-temperature scanning tunneling microscope (STM) by adhering an NdFeB permanent magnet to a magnetizable sample plate. To render our magnet concept compatible with high-temperature sample cleaning procedures, we make the irreversible demagnetization of the magnet a central part of our preparation cycle. After sacrificing the magnet by heating it above its Curie temperature, we use a transfer tool to attach a new magnet in-situ prior to transferring the sample into the STM. We characterize the magnetic field created by the magnet using the Abrikosov vortex lattice of superconducting NbSe2. Excellent agreement between the distance dependent magnetic fields from experiments and simulations allows us to predict the magnitude and orientation of magnetic flux at any location with respect to the magnet and the sample plate. Our concept is an accessible solution for field-dependent surface science studies that require fields in the range of up to 400 mT and otherwise detrimental heating procedures.•Accessible magnetic field generation.•Selectable field strength and orientation.•Compatible with high-temperature sample preparation.

Discovery of superconductivity in Nb4SiSb2 with a V4SiSb2-type structure and implications of interstitial doping on its physical properties.

We report on the discovery, structural analysis, and the physical properties of Nb4SiSb2 - a hitherto unknown compound crystallizing in the V4SiSb2-type structure with the tetragonal space group I4/mcm and unit cell parameters a = 10.3638(2) Å and c = 4.9151(2) Å. We find Nb4SiSb2 to be a metal undergoing a transition to a superconducting state at a critical temperature of T c ≈ 1.6 K. The bulk nature of the superconductivity in this material is confirmed by the observation of a well defined discontinuity in specific heat with a normalized specific heat jump of ΔC(T c)/γT c = 1.33 mJ mol-1 K-2. We find that for Nb4SiSb2, the unoccupied sites on the 4b Wyckoff position can be partially occupied with Cu, Pd, or Pt. Low-temperature resistivity measurements show transitions to superconductivity for all three compounds at T c ≈ 1.2 K for Nb4Cu0.2SiSb2, and T c ≈ 0.8 K for Nb4Pd0.2SiSb2 as well as for Nb4Pt0.14SiSb2. The addition of electron-donor atoms into these void positions, henceforth, lowers the superconducting transition temperature in comparison to the parent compound.

A shocking injury: A clinical review of lightning injuries highlighting pitfalls and a treatment protocol.

INTRODUCTION: Lightning strikes have high morbidity and mortality rates. Thousands of fatalities are estimated to be caused by lightning worldwide, with the number of injuries being 10 times greater. However, evidence of lightning injuries is restricted to case reports and series and nonsystematic reviews. In this clinical review, we systematically select, score, and present evidence regarding lightning injuries. MATERIAL AND METHODS: We performed a systematic search for reviews and guidelines in the PubMed, Embase (OvidSP), MEDLINE (OvidSP), and Web of Science databases. All publications were scored according to the Levels of Evidence 2 Table of the Oxford center for Evidence-Based Medicine. The reviews were also scored using the scale for the quality assessment of narrative review articles (SANRA) and guidelines from the Appraisal of Guidelines for Research & Evaluation (AGREE II). RESULTS: The search yielded 536 articles. Eventually, 56 articles were included, which consisted of 50 reviews, five guidelines and one overview. The available reviews and guidelines were graded as low to moderate evidence. Most damage from lightning injuries is cardiovascular and neurological, although an individual can experience complications with any of their vital functions. At the scene, initial treatment and resuscitation should focus on those who appear to be dead, which is called the reverse triage system. We proposed an evidence-based treatment protocol for lightning strike patients. CONCLUSION: It is vital that every lightning strike patient is treated according to standard trauma guidelines, with a specific focus on the possible sequelae of lighting injuries. All emergency healthcare professionals should acknowledge the risks and particularities of treating lighting strike injuries to optimize the care and outcomes of these patients. Our evidence-based treatment protocol should help prehospital and in-hospital emergency healthcare practitioners to prevent therapeutic mismanagement among these patients.

Role of Methoprene-tolerant in the regulation of oogenesis in Dipetalogaster maxima.

Juvenile hormone (JH) signalling, via its receptor Methoprene-tolerant (Met), controls metamorphosis and reproduction in insects. Met belongs to a superfamily of transcription factors containing the basic Helix Loop Helix (bHLH) and Per Arnt Sim (PAS) domains. Since its discovery in 1986, Met has been characterized in several insect species. However, in spite of the importance as vectors of Chagas disease, our knowledge on the role of Met in JH signalling in Triatominae is limited. In this study, we cloned and sequenced the Dipetalogaster maxima Met transcript (DmaxMet). Molecular modelling was used to build the structure of Met and identify the JH binding site. To further understand the role of the JH receptor during oogenesis, transcript levels were evaluated in two main target organs of JH, fat body and ovary. Functional studies using Met RNAi revealed significant decreases of transcripts for vitellogenin (Vg) and lipophorin (Lp), as well as their receptors. Lp and Vg protein amounts in fat body, as well as Vg in hemolymph were also decreased, and ovarian development was impaired. Overall, these studies provide additional molecular insights on the roles of JH signalling in oogenesis in Triatominae; and therefore are relevant for the epidemiology of Chagas´ disease.

Dynamic magnetic crossover at the origin of the hidden-order in van der Waals antiferromagnet CrSBr.

The van-der-Waals material CrSBr stands out as a promising two-dimensional magnet. Here, we report on its detailed magnetic and structural characteristics. We evidence that it undergoes a transition to an A-type antiferromagnetic state below TN ≈ 140 K with a pronounced two-dimensional character, preceded by ferromagnetic correlations within the monolayers. Furthermore, we unravel the low-temperature hidden-order within the long-range magnetically-ordered state. We find that it is associated to a slowing down of the magnetic fluctuations, accompanied by a continuous reorientation of the internal field. These take place upon cooling below Ts ≈ 100 K, until a spin freezing process occurs at T* ≈ 40 K. We argue this complex behavior to reflect a crossover driven by the in-plane uniaxial anisotropy, which is ultimately caused by its mixed-anion character. Our findings reinforce CrSBr as an important candidate for devices in the emergent field of two-dimensional magnetic materials.

Quasi-1D Electronic Transport in a 2D Magnetic Semiconductor.

Electronic transport through exfoliated multilayers of CrSBr, a 2D semiconductor of interest because of its magnetic properties, is investigated. An extremely pronounced anisotropy manifesting itself in qualitative and quantitative differences of all quantities measured along the in-plane a and b crystallographic directions is found. In particular, a qualitatively different dependence of the conductivities σa and σb on temperature and gate voltage, accompanied by orders of magnitude differences in their values (σb /σa  ≈ 3 × 102  to 105 at low temperature and negative gate voltage) are observed, together with a different behavior of the longitudinal magnetoresistance in the two directions and the complete absence of the Hall effect in transverse resistance measurements. These observations appear not to be compatible with a description in terms of conventional band transport of a 2D doped semiconductor. The observed phenomenology-and unambiguous signatures of a 1D van Hove singularity detected in energy-resolved photocurrent measurements-indicate that electronic transport through CrSBr multilayers is better interpreted by considering the system as formed by weakly and incoherently coupled 1D wires, than by conventional 2D band transport. It is concluded that CrSBr is the first 2D semiconductor to show distinctly quasi-1D electronic transport properties.

Quantum Materials Discovery by Combining Chemical and Physical Design Principles.

Exploratory quantum materials discovery remains crucial to progress in material science. Due to the grand challenges that we are facing in predicting these materials and their properties from scratch, chemical design principles remain a key ingredient for the discovery of new materials. Chemical heuristics, structure, bonding, as well as global and local symmetries are at the very foundation of materials properties. In this regard, in this research, we aim to identify functional materials by composition-structure-property understanding. Materials discovery consists of a subset of methods and design principles that go hand in hand until a desired material or property is realized. However, materials synthesis is still far from a rational design approach. Rather, materials, and especially metastable materials, have to be accessed and synthesized in an exploratory, laboratory-intensive fashion. At the same time, quantum materials discovery is a vibrant highly active field of research that has seen various leaps of progress in recent years, and that holds the promise for many more in the coming years. Here, we lay out how we are discovering new materials and new materials physics in our and other chemical physics, or physical chemistry research groups, and how chemistry and chemical synthesis play a crucial role in this process.

Synthetic control over polymorph formation in the d-band semiconductor system FeS2.

Pyrite, also known as fool's gold is the thermodynamic stable polymorph of FeS2. It is widely considered as a promising d-band semiconductor for various applications due to its intriguing physical properties. Marcasite is the other naturally occurring polymorph of FeS2. Measurements on natural crystals have shown that it has similarly promising electronic, mechanical, and optical properties as pyrite. However, it has been only scarcely investigated so far, because the laboratory-based synthesis of phase-pure samples or high quality marcasite single crystal has been a challenge until now. Here, we report the targeted phase formation via hydrothermal synthesis of marcasite and pyrite. The formation condition and phase purity of the FeS2 polymorphs are systematically studied in the form of a comprehensive synthesis map. We, furthermore, report on a detailed analysis of marcasite single crystal growth by a space-separated hydrothermal synthesis. We observe that single phase product of marcasite forms only on the surface under the involvement of H2S and sulphur vapor. The availability of high-quality crystals of marcasite allows us to measure the fundamental physical properties, including an allowed direct optical bandgap of 0.76 eV, temperature independent diamagnetism, an electronic transport gap of 0.11 eV, and a room-temperature carrier concentration of 4.14 × 1018 cm-3. X-ray absorption/emission spectroscopy are employed to measure the band gap of the two FeS2 phases. We find marcasite has a band gap of 0.73 eV, while pyrite has a band gap of 0.87 eV. Our results indicate that marcasite - that is now synthetically available in a straightforward fashion - is as equally promising as pyrite as candidate for various semiconductor applications based on earth abundant elements.

Break of symmetry at the surface of IrTe2upon phase transition measured by x-ray photoelectron diffraction.

IrTe2undergoes a series of charge-ordered phase transitions below room temperature that are characterized by the formation of stripes of Ir dimers of different periodicities. Full hemispherical x-ray photoelectron diffraction (XPD) experiments have been performed to investigate the atomic position changes undergone near the surface of 1T-IrTe2in the first-order phase transition, from the (1 × 1) phase to the (5 × 1) phase. Comparison between experiment and simulation allows us to identify the consequence of the dimerization on the Ir atoms local environment. We report that XPD permits to unveil the break of symmetry of IrTe2trigonal to a monoclinic unit cell and confirm the occurrence of the (5 × 1) reconstruction within the first few layers below the surface with a staircase-like stacking of dimers.

Morphological and Ultrastructural Characterization of Hemocytes in an Insect Model, the Hematophagous Dipetalogaster maxima (Hemiptera: Reduviidae).

Hemocytes, the cells present in the hemolymph of insects and other invertebrates, perform several physiological functions, including innate immunity. The current classification of hemocyte types is based mostly on morphological features; however, divergences have emerged among specialists in triatomines, the insect vectors of Chagas' disease (Hemiptera: Reduviidae). Here, we have combined technical approaches in order to characterize the hemocytes from fifth instar nymphs of the triatomine Dipetalogaster maxima. Moreover, in this work we describe, for the first time, the ultrastructural features of D. maxima hemocytes. Using phase contrast microscopy of fresh preparations, five hemocyte populations were identified and further characterized by immunofluorescence, flow cytometry and transmission electron microscopy. The plasmatocytes and the granulocytes were the most abundant cell types, although prohemocytes, adipohemocytes and oenocytes were also found. This work sheds light on a controversial aspect of triatomine cell biology and physiology setting the basis for future in-depth studies directed to address hemocyte classification using non-microscopy-based markers.

Assessment of Lung Reaeration at 2 Levels of Positive End-expiratory Pressure in Patients With Early and Late COVID-19-related Acute Respiratory Distress Syndrome.

PURPOSE: Patients with novel coronavirus disease (COVID-19) frequently develop acute respiratory distress syndrome (ARDS) and need invasive ventilation. The potential to reaerate consolidated lung tissue in COVID-19-related ARDS is heavily debated. This study assessed the potential to reaerate lung consolidations in patients with COVID-19-related ARDS under invasive ventilation. MATERIALS AND METHODS: This was a retrospective analysis of patients with COVID-19-related ARDS who underwent chest computed tomography (CT) at low positive end-expiratory pressure (PEEP) and after a recruitment maneuver at high PEEP of 20 cm H2O. Lung reaeration, volume, and weight were calculated using both CT scans. CT scans were performed after intubation and start of ventilation (early CT), or after several days of intensive care unit admission (late CT). RESULTS: Twenty-eight patients were analyzed. The median percentages of reaerated and nonaerated lung tissue were 19% [interquartile range, IQR: 10 to 33] and 11% [IQR: 4 to 15] for patients with early and late CT scans, respectively (P=0.049). End-expiratory lung volume showed a median increase of 663 mL [IQR: 483 to 865] and 574 mL [IQR: 292 to 670] after recruitment for patients with early and late CT scans, respectively (P=0.43). The median decrease in lung weight attributed to nonaerated lung tissue was 229 g [IQR: 165 to 376] and 171 g [IQR: 81 to 229] after recruitment for patients with early and late CT scans, respectively (P=0.16). CONCLUSIONS: The majority of patients with COVID-19-related ARDS undergoing invasive ventilation had substantial reaeration of lung consolidations after recruitment and ventilation at high PEEP. Higher PEEP can be considered in patients with reaerated lung consolidations when accompanied by improvement in compliance and gas exchange.

Perioperative approach of allergic patients.

Perioperative allergic reactions are rare, yet important complications of anesthesia. Severe, generalized allergic reactions called anaphylaxis are estimated to have a mortality of 3.5-4.8%. Adequate recognition and handling of a severe perioperative anaphylactic reaction result in better outcomes, including less hypoxic-ischemic encephalopathy and death. The diagnosis of a perioperative allergic reaction can be difficult as the list of possible culprits of a perioperative allergic reaction is extensive. Making an informed guess on the causative agent and avoiding this agent in future anesthesia procedures is undesirable and unsafe. Therefore, to ensure future patient safety, a thorough investigation following a perioperative allergic reaction is mandatory. A collaborate approach by allergists and anesthesiologists is advised. In this article, we discuss the basic approach of the allergic patient and of patients with a suspected allergy to perioperatively administered medication.

Optimizing airway management and ventilation during prehospital advanced life support in out-of-hospital cardiac arrest: A narrative review.

Airway management and ventilation are essential components of cardiopulmonary resuscitation to achieve oxygen delivery in order to prevent hypoxic injury and increase the chance of survival. Weighing the relative benefits and downsides, the best approach is a staged strategy; start with a focus on high-quality chest compressions and defibrillation, then optimize mask ventilation while preparing for advanced airway management with a supraglottic airway device. Endotracheal intubation can still be indicated, but has the largest downsides of all advanced airway techniques. Whichever stage of airway management, ventilation and chest compression quality should be closely monitored. Capnography has many advantages and should be used routinely. Optimizing ventilation strategies, harmonizing ventilation with mechanical chest compression devices, and implementation in complex and stressful environments are challenges we need to face through collaborative innovation, research, and implementation.

A pre-hospital risk score predicts critical illness in non-trauma patients transported by ambulance to a Dutch tertiary referral hospital.

BACKGROUND: Early pre-hospital identification of critically ill patients reduces morbidity and mortality. To identify critically ill non-traumatic and non-cardiac arrest patients, a pre-hospital risk stratification tool was previously developed in the United States. The aim of this study was to investigate the accuracy of this tool in a Dutch Emergency Department. METHODS: This retrospective study included all patients of 18 years and older transported by ambulance to the Emergency Department of a tertiary referral hospital between January 1st 2017 and December 31st 2017. Documentation of pre-hospital vital parameters had to be available. The tool included a full set of vital parameters, which were categorized by predetermined thresholds. Study outcome was the accuracy of the tool in predicting critical illness, defined as admittance to the Intensive Care Unit for delivery of vital organ support or death within 28 days. Accuracy of the risk stratification tool was measured with the Area Under the Receiver Operating Characteristics (AUROC) curve. RESULTS: Nearly 3000 patients were included in the study, of whom 356 patients (12.2%) developed critical illness. We observed moderate discrimination of the pre-hospital risk score with an AUROC of 0.74 (95%-CI 0.71-0.77). Using a threshold of 3 to identify critical illness, we observed a sensitivity of 45.0% (95%-CI 44.8-45.2) and a specificity of 86.0% (95%-CI 85.9-86.0). CONCLUSION: These data show that this pre-hospital risk stratification tool is a moderately effective tool to predict which patients are likely to become critically ill in a Dutch non-trauma and non-cardiac arrest population.

Polytypism and superconductivity in the NbS2 system.

We report on the phase formation and the superconducting properties in the NbS2 system. Specifically, we have performed a series of standardized solid-state syntheses in this system, which allow us to establish a comprehensive synthesis map for the formation of the two polytypes 2H-NbS2 and 3R-NbS2, respectively. We show that the identification of two polytypes by means of X-ray diffraction is not always unambiguous. Our physical property measurements on a phase-pure sample of 3R-NbS2, on a phase-pure sample of 2H-NbS2, and a mixed phase sample confirm earlier reports that 2H-NbS2 is a bulk superconductor and that 3R-NbS2 is not a superconductor above T = 1.75 K. Our results clearly show that specific heat measurements, as true bulk measurements, are crucial for the identification of superconducting materials in this and related systems. Our results indicate that for the investigation of van der Waals materials great care has to be taken on choosing the synthesis conditions for obtaining phase pure samples.

Superconductivity with High Upper Critical Field in the Cubic Centrosymmetric η-Carbide Nb4Rh2C1-δ.

The upper critical field is a fundamental measure of the strength of superconductivity in a material. It is also a cornerstone for the realization of superconducting magnet applications. The critical field arises because of the Cooper pair breaking at a limiting field, which is due to the Pauli paramagnetism of the electrons. The maximal possible magnetic field strength for this effect is commonly known as the Pauli paramagnetic limit given as µ0 H Pauli ≈ 1.86[T/K]·T c for a weak-coupling Bardeen-Schrieffer-Cooper (BCS) superconductor. The violation of this limit is only rarely observed. Exceptions include some low-temperature heavy Fermion and some strongly anisotropic superconductors. Here, we report on the superconductivity at 9.75 K in the centrosymmetric, cubic η-carbide-type compound Nb4Rh2C1-δ, with a normalized specific heat jump of ΔC/γT c = 1.64. We find that this material has a remarkably high upper critical field of µ0 H c2(0) = 28.5 T, which is exceeding by far its weak-coupling BCS Pauli paramagnetic limit of µ0 H Pauli = 18.1 T. Determination of the origin and consequences of this effect will represent a significant new direction in the study of critical fields in superconductors.

Effect of influenza A virus sow vaccination on infection in pigs at weaning: A prospective longitudinal study.

Although vaccination is the main measure to control influenza A virus (IAV) in swine, there is limited information on the efficacy of sow vaccination on reducing IAV infections in pigs at weaning. We assessed the effect of sow vaccination on IAV infection in pigs at weaning in a cohort of 52 breeding herds studied prospectively. Herds were voluntarily enrolled according to their IAV history, sow vaccination protocol and monitored during six months (prospective longitudinal study). On each herd, nasal swabs were collected monthly from 30 pigs at weaning and tested for IAV by RT-PCR. IAV was detected in 25% (75/305) of sampling events. Of 9,150 nasal swab pools (3 individual nasal swabs/pool), 15% (458/3050) of pools tested IAV positive. IAV infections in pigs at weaning were lower in vaccinated herds compared to non-vaccinated ones. Moreover, no significant differences were seen between prefarrow and whole herd protocols, or the use of commercial versus autogenous IAV vaccines. Prefarrow and whole herd vaccination protocols reduced the odds of groups testing IAV positive at weaning in comparison with no vaccination. Our results are relevant when considering implementation of sow vaccination to control influenza infections in pigs at weaning and, hence, minimize transmission to growing pigs and other farms.