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Firefighters are routinely exposed to various traumatic events and often experience a range of trauma-related symptoms. Although these repeated traumatic exposures rarely progress to the development of post-traumatic stress disorder, firefighters are still considered to be a vulnerable population with regard to trauma.
To investigate how the human brain responds to or compensates for the repeated experience of traumatic stress.
We included 98 healthy firefighters with repeated traumatic experiences but without any diagnosis of mental illness and 98 non-firefighter healthy individuals without any history of trauma. Functional connectivity within the fear circuitry, which consists of the dorsal anterior cingulate cortex, insula, amygdala, hippocampus and ventromedial prefrontal cortex (vmPFC), was examined using resting-state functional magnetic resonance imaging. Trauma-related symptoms were evaluated using the Impact of Event Scale – Revised.
The firefighter group had greater functional connectivity between the insula and several regions of the fear circuitry including the bilateral amygdalae, bilateral hippocampi and vmPFC as compared with healthy individuals. In the firefighter group, stronger insula–amygdala connectivity was associated with greater severity of trauma-related symptoms (β = 0.36, P = 0.005), whereas higher insula–vmPFC connectivity was related to milder symptoms in response to repeated trauma (β = −0.28, P = 0.01).
The current findings suggest an active involvement of insular functional connectivity in response to repeated traumatic stress. Functional connectivity of the insula in relation to the amygdala and vmPFC may be potential pathways that underlie the risk for and resilience to repeated traumatic stress, respectively.
Syncope accounts for 1% of emergency department (ED) visits, yet few experience a serious adverse event (SAE). Two-thirds of syncope patients are transported to the ED by ambulance, placing considerable burden on emergency medical services (EMS), and many of these transports may be unnecessary. We estimated the proportion of syncope patients who fell into a low-risk category based on an ED diagnosis of vasovagal syncope and the absence of EMS intervention, hospitalization, or SAE.
We conducted a multicentre prospective cohort study enrolling adult syncope patients transported to the ED by ambulance over 13 months. We collected demographics and EMS interventions, and followed patients for 30 days to identify all SAE, including death, dysrhythmia, myocardial infarction, aortic dissection, pulmonary embolism, subarachnoid hemorrhage, significant hemorrhage, and related procedural interventions.
Of 990 (67.2%) patients transported to the ED by ambulance, 121 had EMS interventions, 137 suffered 30-day SAE, 393 (39.7%; 95%CI 36.6, 42.8) were deemed low risk, 41 patients with vasovagal syncope were lost to follow-up, and 298 patients were diagnosed with non-vasovagal syncope. During transport, 121 (12.2%; 95%CI 10.2, 14.3) patients underwent some EMS intervention, and 137 (14.6%; 95%CI 12.4, 16.9) suffered SAEs within 30 days.
About 40% of patients transported to the ED by ambulance are at low risk and may not benefit from paramedic care or transport to a hospital. A robust clinical decision tool would help identify patients safe for treat-and-release, diversion to alternative care, or rapid offload into low-acuity ED areas, potentially reducing EMS workload and cost.
Introduction: Existing resources to support adolescents with acquired brain injury (ABI) in transition from school to the ‘adult world’ are variable. This study evaluated an intervention using a coaching approach to support adolescents during this transition phase.
Method: The study design was a parallel-group randomised controlled trial (RCT). Participants (n = 43) aged 14–19 years were randomised to intervention (n = 21) or no-intervention control (n = 21) conditions. The intervention group received six coaching sessions over an average of 22 weeks. Outcome measures evaluated changes reported by the adolescent (satisfaction, emotional functioning and hope) and their parent (participation, behaviour and support needs).
Results: Relative to baseline, there was no significant improvement for those in the intervention group in comparison to the control group on any of the outcome measures.
Conclusion: The results of this RCT do not support coaching as an intervention for adolescents with ABI.
To examine the nutritional quality of menu items promoted in four (US) fast-food restaurant chains (McDonald’s, Burger King, Wendy’s, Taco Bell) in 2010 and 2013.
Menu items pictured on signs and menu boards were recorded at 400 fast-food restaurants across the USA. The Nutrient Profile Index (NPI) was used to calculate overall nutrition scores for items (higher scores indicate greater nutritional quality) and was dichotomized to denote healthier v. less healthy items. Changes over time in NPI scores and energy of promoted foods and beverages were analysed using linear regression.
Four hundred fast-food restaurants (McDonald’s, Burger King, Wendy’s, Taco Bell; 100 locations per chain).
NPI of fast-food items marketed at fast-food restaurants.
Promoted foods and beverages on general menu boards and signs remained below the ‘healthier’ cut-off at both time points. On general menu boards, pictured items became modestly healthier from 2010 to 2013, increasing (mean (se)) by 3·08 (0·16) NPI score points (P<0·001) and decreasing (mean (se)) by 130 (15) kJ (31·1 (3·65) kcal; P<0·001). This pattern was evident in all chains except Taco Bell, where pictured items increased in energy. Foods and beverages pictured on the kids’ section showed the greatest nutritional improvements. Although promoted foods on general menu boards and signs improved in nutritional quality, beverages remained the same or became worse.
Foods, and to a lesser extent, beverages, promoted on menu boards and signs in fast-food restaurants showed limited improvements in nutritional quality in 2013 v. 2010.
The mechanical properties of organic electronic materials and interfaces play a central role in determining the manufacturability and reliability of flexible and stretchable organic electronic devices. The synergistic effects of mechanical stress and deformation, together with other operating parameters such as temperature and temperature cycling, and exposure to solar radiation, moisture, and other environmental species are particularly important for longer-term device stability. We review recent studies of basic mechanical properties such as adhesion and cohesion, stiffness, yield behavior, and ductility of organic semiconducting materials, and their connection to underlying molecular structure. We highlight thin-film metrologies to probe the mechanical behavior, including when subjected to simulated operational conditions. We also report on strategies for improving reliability through interface engineering and tailoring material chemistry and molecular structure. These studies provide insights into how these metrologies and metrics inform the development of materials and devices for improved reliability.
Africa is experiencing a rapid increase in adult obesity and associated cardiometabolic diseases (CMDs). The H3Africa AWI-Gen Collaborative Centre was established to examine genomic and environmental factors that influence body composition, body fat distribution and CMD risk, with the aim to provide insights towards effective treatment and intervention strategies. It provides a research platform of over 10 500 participants, 40–60 years old, from Burkina Faso, Ghana, Kenya and South Africa. Following a process that involved community engagement, training of project staff and participant informed consent, participants were administered detailed questionnaires, anthropometric measurements were taken and biospecimens collected. This generated a wealth of demographic, health history, environmental, behavioural and biomarker data. The H3Africa SNP array will be used for genome-wide association studies. AWI-Gen is building capacity to perform large epidemiological, genomic and epigenomic studies across several African counties and strives to become a valuable resource for research collaborations in Africa.
Here we introduce a cost-effective and highly sensitive flexible accelerometer system, which can sense human pulse by detecting the pulsation. The accelerometer employs capacitive sensing with a structure of two parallel plate electrodes with the optimally designed top electrode pattern in order to achieve high sensitivity. This flexible light-weight sensor is fabricated by direct-printing of silver nano-inks on pre-patterned flexible paper substrates. When the accelerometer is attached to the body surfaces: neck, inner elbow, or any other pulsation point, accurate pulse rates are obtained by reading out the voltage output signal.
Roughness parameters of sample surface and buried interfaces in a series of thin layers of Si0.4 GeO.6 grown on Si(100) by molecular beam epitaxy (MBE) were measured by using the technique of grazing-incidence x-ray scattering (GIXS). The strain in the layer and the critical thickness of the film were determined from x-ray diffraction of the Si(004) peak. The roughness parameters can be described by a scaling-law with an exponent β = 0.71 for both the surface and interfacial roughness. Establishment of a scaling law thus allows a possibility of predicting the interfacial roughness as a function of the epilayer thickness.
Acceptance and commitment therapy (ACT) is increasingly used in clinical practice to manage anxiety conditions. This psychotherapeutic approach focuses on the following: (1) acceptance of an individual's experience of the spectrum of psychological and emotional states, (2) choosing valued direction for the individual's life, and (3) commitment to action that leads the individual in the direction of those values. This article presents an empirical review of ACT for treatment of anxiety in two parts. In the first part we systematically review the literature for studies examining ACT for anxiety management in the general population with anxiety problems. In the second part, we discuss applicability of acceptance-based approaches for a health population in which these techniques may have applicability, that is, for people with acquired brain injury (ABI). Electronic searches for the review were conducted on PsycINFO and Medline. Inclusion criteria were as follows: (1) used an ACT intervention study, (2) the target of the intervention was an anxiety disorder or anxiety symptomatology, (3) the intervention used a randomised controlled trial (RCT) or single case experimental design (SCED) methodology, and (4) the paper was available in English. Studies were rated for methodological quality using standardised assessment procedures. Four RCTs provided support for ACT for obsessive compulsive disorder (OCD), maths anxiety, trichotillomania (TTM), and mixed anxiety and depression. Three SCED trials scoring in the high range on the scale of methodological quality revealed some support for ACT for managing TTM, skin picking, and OCD. Although no studies were identified that investigated ACT for managing anxiety in people with ABI, the review highlights issues for consideration when applying ACT in this population.
A novel approach of fabricating 2-D arrays of SiO2 beads on a Si surface using the Langmuir-Blodgett (LB) technique is reported. The corrugated surfaces were tested as a separation media for surface electrophoresis of DNA molecules. The measured electrophoretic mobility for λ-DNA is only 20% slower than previously measured on a flat Si wafer. This indicates that the separation mechanism is due to surface friction rather than biased reptation as reported by Tinland in the three dimensional Silica bead matrix where the mobility is two orders of magnitude smaller.
Garnet phases have been considered as a durable crystalline waste form for hosting actinide. The garnet-structure phases with stoichiometries of Ca2,5Ce0,5Zr2Fe3O12, Ca2CeZrFeFe3O12, and Ca1,5GdCe0,5ZrFeFe3O12 were synthesized through cold pressing and sintering in air and oxygen to determine the optimum parameters for the formation of actinide waste forms. Cerium (Ce) was used as an imitator of plutonium due to its similarity in oxidation state and ionic radii. Gadolinium (Gd) plays a major role as an absorber of neutrons that prevents nuclear chain reaction. It also serves as imitators of the trivalent actinides. Ce-garnet or (Ce,Gd)-garnet is chemically analogous to the garnets with plutonium and/or trivalent actinides. The results of XRD and SEM-EDS examination of the products of experiments reveal that equilibrium state was reached at the temperatures of 1300 °C and 1200 °C for 1 and 5 hours heating, respectively.
Porcelain (veneer layer)/alumina (core layer) is a typical dental crown structure. Due to its high incidence of failure, a new porcelain/mullite (buffer layer)/alumina trilayer structure is designed, fabricated, and evaluated. Alumina green bodies were prepared by gel-casting process, and then calcined at 900 and 1100°C to infiltrate mullite precursor slurry of silica-rich (Al2O3·2SiO2) composition into the bodies. Porosity in the bodies is not dependent on calcination temperature, resulting in a similar infiltration depth. Porcelain was coated on the alumina sintered at 1600°C with and without mullite buffer layer. There are no delamination or cracks observed after firing the layered materials. Rod type microstructure and continuous composition are indicated at the interface in the case of the layered structure with mullite buffer layer. To investigate the cracking resistance behavior for this new structure, Vickers indentation and Hertzian contact fatigue tests were conducted. Cracks do not penetrate the interface with mullite buffer layer into the porcelain, showing a reversal case for the layered structure without mullite buffer layer. The layered structure with mullite buffer layer shows higher critical load for fracture than that without mullite buffer layer. Fracture mode of the layered structures in cyclic fatigue shows a top layer (porcelain) fracture at relatively low load (P = 250 N) and higher cycles (n = 106), and a bottom layer (alumina) fracture at higher load (P = 300 N) and relatively low cycles (n = 105).
Ag nanoparticles have been prepared by thermal decomposition of Ag-oleate complex using electric furnace at 300 °C for about 4 hrs. TEM images of the particles showed 2-dimensional assembly of particles with diameter of 8.0 ± 1.3 nm, demonstrating the uniformity of these nanoparticles. Ag-TiO2 nanoparticles were synthesized by sol-gel process and they had core-shell structure. Results showed the formation of the silver core and titanium oxide shell. In this study, we investigated the structure of Ag nanoparticle and Ag-TiO2 nanoparticle and Ag-TiO2-chitosan complex and their functions of antibiosis and deodorization.
This is Part II of a tribological study of metal/ceramic pair in a sliding contact. The tribological behavior of molybdenum against a single crystal A12O3 was investigated at bulk temperatures of 23ºC and 400ºC using a sliding speed of 4 m/s and loads from nine to twenty five Newtons. The role of oxidational wear was confirmed at both temperatures. The linear dependency of wear rate on load was identified at 23ºC tests. At 400ºC, there was a rapid increase of wear rate at a load of about 25 N possibly due to the volatilization of MoO3, which is the limitation of molybdenum oxide as a solid lubricant. However, this study showed that the out-of-contact oxide formation may have prevented the catastrophic oxidation during contact at the real area of contact. It also showed that in-situ formed molybdenum oxide has good lubricating properties (≃ 0.3) and a low wear rate (≃ 10-14 m3/m). Therefore, this molybdenum can be used for a large range of sliding speeds and loads.
Superconducting films of YBa2Cu3O7−6 obtained by laser ablation on MgO and ZrO2 substrates were investigated by soft x-ray absorption fine structure technique (XAFS) at O K-edge. Local environment around oxygen atoms was probed and information on the distribution of the nearestneighbors was obtained. Much higher degree of local disorder than that in a bulk YBa2Cu3O7−δ sample was observed.
Angular dependence of grazing incidence x-ray scattering and Ge fluorescence yield were measured for the heterostructures of Si1-xGex/Si and the inverted bilayer Si/Si1-xGex as well as two 10-period superlattices. Interfacial roughness, correlation of height fluctuations between interfaces and Ge density profiles in the multilayers were investigated.
Multiphoton excitations of conjugated polymers are related to their optical gap, Eg, which serves as an internal standard. In π-electron models with electron-hole symmetry, the alternation gap Ea is the lowest-energy two-photon absorption (TPA) and increases with the alternation δ of the transfer integrals t(l ± δ) along the backbone. Increasing electron-electron (e-e) correlations shift an intense TPA from 2Eg in the band limit to Eg in the atomic limit. Two-photon spectra and multiphoton resonances in polyenes, polydiacetylenes, and polysilanes are related to interacting electrons in Pariser-Parr-Pople(PPP) models with increasing alternation and either carbon or silicon e-e interactions. Some general features of correlated states of conjugated polymers are discussed in the rigid-lattice limit.
We have studied charge carrier generation by photons in thin films of poly(di-n-hexylsilane) over the photon energy range 3.15 to 6 eV and find that it is nonlinear in light intensity to above 4.5 eV. We show that the generation mechanism is exciton-exciton annihilation.