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Abstract Background To examine sedentary time, prolonged sedentary bouts and physical activity in Australian employees from different workplace settings, within work and non-work contexts. Methods A convenience sample of 193 employees working in offices (131), call centres (36) and customer service (26) was recruited. Actigraph GT1M accelerometers were used to derive percentages of time spent sedentary ( Results Working hours were mostly spent sedentary (77.0%, 95%CI: 76.3, 77.6), with approximately half of this time accumulated in prolonged bouts of 20 minutes or more. There were significant (p Conclusion The workplace is a key setting for prolonged sedentary time, especially for some occupational groups, and the potential health risk burden attached requires investigation. Future workplace regulations and health promotion initiatives for sedentary occupations to reduce prolonged sitting time should be considered.

Abstract Background With an increasing research focus on multiple health behaviour change interventions, a methodological issue requiring further investigation is whether or not to employ pre-trial behavioural screening to exclude participants who are achieving a pre-specified level of one or more behaviours. Behavioural screening can be used to direct limited resources to participants most in need of a behaviour change intervention; but may reduce the representativeness of the sample and limit comparability with trials that do not employ pre-trial behavioural screening. Furthermore, the impact of this type of screening on intervention participation and intervention effects is unknown. Methods Data for this study come from the Logan Healthy Living Program, a randomised, controlled telephone counselling lifestyle intervention trial which did not employ behavioural screening prior to randomisation. Screening for physical activity, diet or the combination was simulated using baseline trial data. To examine the impact of behavioural screening on intervention participation (in terms of participant characteristics, intervention dose received and retention), characteristics of participants included an excluded under the various screening scenarios were compared. To examine the impact of behavioural screening on intervention effects, results from the main trial analysis were compared with results obtained from the same analyses performed separately for each of the screened groups. Results Simulated pre-trial behavioural screening impacted minimally on intervention dose received and trial retention rate. Beyond the anticipated effect of reducing baseline levels of the behaviours being screened for, behavioural screening affected baseline levels of behaviours not targeted by screening, and participants' demographic and health-related characteristics. Behavioural screening impacted on intervention effects in ways that were anticipated and positive, but also unexpected and detrimental. Physical activity screening (alone or in combination with diet) resulted in improved intervention effects for physical activity, while fruit and vegetable screening had no impact on intervention effects for these outcomes. All three types of screening impacted detrimentally on intervention effects for behaviours not being targeted by screening. Conclusions Behavioural screening may have desirable and undesirable consequences in the context of multiple behaviour intervention trials, and thus its potential merits and pitfalls should be carefully considered.

Introduction: Follow-up testing is recommended three months after patients initially test positive with Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (GC). Follow-up testing adherence in the United States has been reported below one third of women, even in universally insured populations. We assessed both the positivity of CT and GC infections in female basic military trainees and the rates of follow-up testing for those who tested positive., Methods: Between January 1, 2006-December 31, 2021, female Air Force Basic Military Trainees were universally screened with urinary nucleic acid amplification testing for CT and GC. Those who tested positive were evaluated to determine demographic information as well as follow-up testing rates. Patients who were evaluated with a repeat CT/GC NAAT test within 12 months after a positive CT/GC test result were considered to have received appropriate follow-up., Results: 5,022 (5.2%) of 97,168 trainees tested positive for only-CT (4,749 (4.8%)), only GC (138 (0.1%)) or both CT/GC (135 (0.1%) during the study period. Those at increased risk of infection were those <24 years of age, Hispanic and Black individuals, high school education level, and single women. Of the 4,687 still in the military at three months after diagnosis, 3,268 (69.7%) had repeat testing within 12 months. There was no significant difference in follow-up testing by age, race, educational level, marital status, or organism causing original infection., Conclusion: Follow-up testing among female USAF basic military trainees is higher than in other universally insured populations. This study demonstrates remaining barriers to adherence to recommended guidelines., Competing Interests: Conflicts of Interest: No authors report any conflicts of interest with this research., (Copyright © 2024 American Sexually Transmitted Diseases Association. All rights reserved.)

In this retrospective cohort study of military trainees, symptomatic-only coronavirus disease 2019 (COVID-19) arrival antigen testing decreased isolation requirements without increasing secondary cases compared to universal antigen testing. Symptomatic-only arrival antigen testing is a feasible alternative for individuals entering a congregant setting with a high risk of COVID-19 transmission., (© Cambridge University Press 2024.)

The Department of the Air Force performs universal antibody serology testing for hepatitis B surface antibody (anti-HBs) and hepatitis A immunoglobulin G (IgG anti-HAV) among enlisted recruits presenting to basic military training (BMT) at Joint Base San Antonio (JBSA)-Lackland. These results, along with previous vaccination records, if available at the time of accession, guide HBV and HAV vaccination during BMT. Data from January 1, 2023, through December 31, 2023, in the electronic health record, MHS-GENESIS, was used for this analysis. This analysis shows a much higher prevalence of HAV antibodies compared to HBV in the trainee population at JBSA-Lackland during 2023.

Background: The burden of transfusion-transmitted infections among blood recipients remains low due to extensive pre- and post-donation screening. However, the military has the unique challenge of providing blood in austere environments with limited testing capabilities. This study evaluates the infectious etiologies of deferred blood donors at a large military blood donation center., Methods: All blood donors at the Armed Service Blood Bank Center, San Antonio, between 2017 and 2022 with positive post-donation screening for hepatitis C (HCV), hepatitis B (HBV), human immunodeficiency virus (HIV), human T-lymphotropic virus (HTLV-I/II), Zika (2018-2021), West Nile virus, Trypanosoma cruzi, Treponema pallidum, or Babesia microti (2020-2022) were evaluated. Donors were deferred based on Food and Drug Administration (FDA) guidance., Results: Two-hundred and thirteen (213) donors met FDA criteria for deferral. T. pallidum (n = 45, 50.3 per 100,000), HCV (n = 34, 38.0 per 100,000), and HBV (n = 19, 21.2 per 100,000) were the most common pathogens among those with both positive screening and confirmatory testing. The majority of HIV (95%), Chagas (78%), HTLV-I/II (50%) deferrals were due to indeterminate confirmatory tests following initial positive screens. The majority of deferrals for HBV were for a second occurrence of a positive screen despite negative confirmatory testing., Conclusion: The rates of post-donation deferral for transfusion-transmissible infections were low in this military cohort. Our findings suggest that donor testing in deployed service members should focus on HBV, HCV, and T. pallidum and highlight the need for better diagnostics for HIV, Chagas, and HTLV-I/II., (Published 2023. This article is a U.S. Government work and is in the public domain in the USA.)

In magnetic tunnel junctions based on iron oxide nanoparticles the disorder and the oxidation state of the surface spin as well as the nanoparticles functionalization play a crucial role in the magnetotransport properties. In this work, we report a systematic study of the effects of vacuum annealing on the structural, magnetic and transport properties of self-assembled ∼10 nm Fe 3 O 4 nanoparticles. The high temperature treatment (from 573 to 873 K) decomposes the organic coating into amorphous carbon, reducing the electrical resistivity of the assemblies by 4 orders of magnitude. At the same time, the 3.Fe 2+ /(Fe 3+ +Fe 2+ ) ratio is reduced from 1.11 to 0.13 when the annealing temperature of the sample increases from 573 to 873 K, indicating an important surface oxidation. Although the 2 nm physical gap remains unchanged with the thermal treatment, a monotonous decrease of tunnel barrier width was obtained from the electron transport measurements when the annealing temperature increases, indicating an increment in the number of defects and hot-spots in the gap between the nanoparticles. This is reflected in the reduction of the spin dependent tunneling, which reduces the interparticle magnetoresistance. This work shows new insights about influence of the nanoparticle interfacial composition, as well their the spatial arrangement, on the tunnel transport of self-assemblies, and evidence the importance of optimizing the nanostructure fabrication for increasing the tunneling current without degrading the spin polarized current., (© 2023 IOP Publishing Ltd.)

Introduction: A booster dose of messenger RNA vaccine protects against severe COVID-19 outcomes. This study examined the incidence of COVID-19 booster vaccination among active-duty U.S. military servicemembers between August 2021 and January 2022, factors associated with vaccination uptake, and trends over time., Methods: This was a retrospective cohort study of active-duty military personnel using data from the Defense Medical Surveillance System. Participants were included if they served in the active component from August 2021 through January 2022 and were eligible to receive a COVID-19 booster dose by January 2022. Adjusted hazard ratio estimates of time to booster vaccination were calculated using Cox proportional hazards regression., Results: Lower booster vaccine uptake was seen in the U.S. military (25%) than among the general U.S. population at the same time (45%). Booster vaccination increased with older age, with greater education, with higher income, among women, and among those stationed overseas; it decreased with previous COVID-19 infection and use of the Janssen vaccine. There were no significant racial or ethnic disparities in booster vaccination., Conclusions: In the absence of a compulsory vaccination policy, lower booster vaccine uptake was seen among servicemembers than among the general U.S. population, particularly among members who were younger, were male, Marines, and had a previous history of infection. Low vaccination rates not only increase the risk of acute and long-term health effects from COVID-19 among servicemembers, but they also degrade the overall readiness of the U.S. military., (Published by Elsevier Inc.)

Formation of oxygen-based free radicals from photochemical decomposition of hydrogen peroxide (H 2 O 2 ) on Mars may be a key factor in the potential survival of terrestrial-like organisms on the red planet. Martian conditions that generate reactive oxygen species involve the decomposition of H 2 O 2 at temperatures of around 278 K under relatively high doses of C-band ultraviolet radiation (UVC). This process is further amplified by the presence of iron oxides and perchlorates. Photosynthetic organisms exhibit a number of evolutionary traits that allow them to withstand both oxidative stress and UVC radiation. Here, we examine the effect of free radicals produced by the decomposition of H 2 O 2 under emulated martian conditions on the viability of Scenedesmus dimorphus , a unicellular alga that is resistant to UVC radiation and varying levels of perchlorate and H 2 O 2 , both of which are present on Mars. Identification and quantification of free radicals formed under these conditions were performed with Electron Paramagnetic Resonance spectroscopy. These results were correlated with the viability of S. dimorphus , and the formation of oxygen-based free radicals and survival of the alga were found to be strongly dependent on the amount of H 2 O 2 available. For H 2 O 2 amounts close to those present in the rarefied martian environment, the products of these catalytic reactions did not have a significant effect on the algal population growth curve.

In this work it is shown a precise way to optimize the heat generation in high viscosity magnetic colloids, by adjusting the Néel relaxation time in core/shell bimagnetic nanoparticles, for magnetic fluid hyperthermia (MFH) applications. To pursue this goal, Fe 3 O 4 /Zn x Co 1-x Fe 2 O 4 core/shell nanoparticles were synthesized with 8.5 nm mean core diameter, encapsulated in a shell of ∼1.1 nm of thickness, where the Zn atomic ratio (Zn/(Zn + Co) at%) changes from 33 to 68 at%. The magnetic measurements are consistent with a rigid interface coupling between the core and shell phases, where the effective magnetic anisotropy systematically decreases when the Zn concentration increases, without a significant change of the saturation magnetization. Experiments of MFH of 0.1 wt% of these particles dispersed in water, in Dulbecco modified Eagles minimal essential medium, and a high viscosity butter oil, result in a large specific loss power (SLP), up to 150 W g -1 , when the experiments are performed at 571 kHz and 200 Oe. The SLP was optimized adjusting the shell composition, showing a maximum for intermediate Zn concentration. This study shows a way to maximize the heat generation in viscous media like cytosol, for those biomedical applications that require smaller particle sizes.

Iron oxide nanoparticles (IONPs) are frequently used in biomedical applications due to their magnetic properties and putative chemical stability. Nevertheless, their well-known ability to mimic some features of the peroxidase enzyme activity under specific conditions of pH and temperature could lead to the formation of potentially harmful free radical species. In addition to the intrinsic enzyme-like activity of IONPs, the buffer solution is an important external factor that can alter dramatically the IONP activity because the buffer species can interact with the surface of the particles. In our study, IONP activity was evaluated in different buffering solutions under different experimental conditions and predominant free radical species were measured by electron paramagnetic resonance using the spin-trap 5,5-dimethyl-1-pyrroline N-oxide (DMPO). The formation kinetics of the reactive oxygen species were studied by UV-visible spectroscopy with TMB and DAB peroxidase substrates. We found that the highest catalytic oxidation of peroxidase substrates and free radical generation were achieved in acetate buffer, while phosphate buffer inhibited the peroxidase-like activity of IONPs in a concentration dependent manner. When emulating the physiological conditions, a lower catalytic activity was observed at pH 7.4 when compared to that at pH 5.0. Also, in phosphate buffered saline (PBS), we observed an enhancement in the peroxidase substrate oxidation rate that was not accompanied by an increase in DMPO/adduct formation which could be related to a non-specific oxidation catalyzed by the chloride ion. Similar observations were found after the addition of a bicarbonate to HEPES buffer. TMB oxidation did not occur when the reaction was conducted with free iron ions from metal salts with the same concentration of the IONPs (0.33 Fe2+ and 0.66 Fe3+). However, we observed even higher catalytic activities than those when doubling the IONP concentration when they are combined with the free iron salts. These results indicate that biological buffering solutions need to be carefully considered when evaluating IONP catalytic activity and their potential toxicological effects since under physiological conditions of pH, salinity and buffering species, the peroxidase-like activity of IONPs is dramatically reduced.

We report a simple and effective way to control the heat generation of a magnetic colloid under alternate magnetic fields by changing the shell composition of bimagnetic core-shell Fe3O4/ZnxCo1-xFe2O4 nanoparticles. The core-shell structure constitutes a magnetically-coupled biphase system, with an effective anisotropy that can be tuned by the substitution of Co2+ by Zn2+ ions in the shell. Magnetic hyperthermia experiments of nanoparticles dispersed in hexane and butter oil showed that the magnetic relaxation is dominated by Brown relaxation mechanism in samples with higher anisotropy (i.e., larger concentration of Co within the shell) yielding high specific power absorption values in low viscosity media as hexane. Increasing the Zn concentration of the shell, diminishes the magnetic anisotropy, which results in a change to a Néel relaxation that dominates the process when the nanoparticles are dispersed in a high-viscosity medium. We demonstrate that tuning the Zn contents at the shell of these exchange-coupled core/shell nanoparticles provides a way to control the magnetic anisotropy without loss of saturation magnetization. This ability is an essential prerequisite for most biomedical applications, where high viscosities and capturing mechanisms are present.

In order to explore an alternative strategy to design exchange-biased magnetic nanostructures, bimagnetic core/shell nanoparticles have been fabricated by a thermal decomposition method and systematically studied as a function of the interface exchange coupling. The nanoparticles are constituted by a ∼3 nm antiferromagnetic (AFM) CoO core encapsulated in a ∼4 nm-thick Co 1-x Zn x Fe 2 O 4 (x = 0-1) ferrimagnetic (FiM) shell. The system presents an enhancement of the coercivity (H C ) as compared to its FiM single-phase counterpart and exchange bias fields (H EB ). While H C decreases monotonically with the Zn concentration from ∼21.5 kOe for x = 0, to ∼7.1 kOe for x = 1, H EB exhibits a non-monotonous behavior being maximum, H EB ∼ 1.4 kOe, for intermediate concentrations. We found that the relationship between the AFM anisotropy energy and the exchange coupling energy can be tuned by replacing Co 2+ with Zn 2+ ions in the shell. As a consequence, the magnetization reversal mechanism of the system is changed from an AFM/FiM rigid-coupling regime to an exchange-biased regime, providing a new approach to tune the magnetic properties and to design novel hybrid nanostructures.

In this work, we present a study of the low temperature magnetic phases of polycrystalline MnCr2O4 spinel through dc magnetization and ferromagnetic resonance spectroscopy (FMR). Through these experiments, we determined the main characteristic temperatures: T(C) ∼ 41 K and T(H) ∼ 18 K corresponding, respectively, to the ferrimagnetic order and to the low temperature helicoidal transitions. The temperature evolution of the system is described by a phenomenological approach that considers the different terms that contribute to the free energy density. Below the Curie temperature, the FMR spectra were modeled by a cubic magnetocrystalline anisotropy to the second order, with K1 and K2 anisotropy constants that define the easy magnetization axis along the <1 1 0> direction. At lower temperatures, the formation of a helicoidal phase was considered by including uniaxial anisotropy axis along the [11¯0] propagation direction of the spiral arrange, with a Ku anisotropy constant. The values obtained from the fittings at 5 K are K1 = -2.3 × 10(4) erg cm(-3), K2 = 6.4 × 10(4) erg cm(-3) and Ku = 7.5 × 10(4) erg cm(-3).

The control of the size of bimagnetic nanoparticles represents an important step toward the study of fundamental properties and the design of new nanostructured magnetic materials. We report the synthesis and the structural and magnetic characterization of bimagnetic CoO/CoFe2O4 core/shell nanoparticles. The material was fabricated by a seed-mediated growth high-temperature decomposition method with sizes in the range of 5-11 nm. We show that the core/shell morphology favours the crystallinity of the shell phase, and the reduction of the particle size leads to a remarkable increase of the magnetic hardening. When the size is reduced, the coercive field at 5 K increases from 21.5 kOe to 30.8 kOe, while the blocking temperature decreases from 388 K to 167 K. The size effects on the magnetic behaviour are described through a phenomenological model for strongly ferri-/antiferromagnetic coupled phases.

We have studied the magnetic behaviour of half-doped manganite Y0.5Ca0.5MnO3 in an extended range of temperatures by means of magnetic susceptibility, χ(T), and electron spin resonance (ESR) experiments. At high temperature the system crystallizes in an orthorhombic structure. The resistivity value, ρ ≃ 0.05 Ω cm at 500 K, indicates a metallic behaviour, while the Curie-Weiss dependence of χ(T) and the thermal evolution of the ESR parameters are very well described by a model that considers a system conformed by localized Mn(4+) cores, [Formula: see text], and itinerant, eg, electrons. The strong coupling between t2g and eg electrons results in an enhanced Curie constant and an FM Curie-Weiss temperature that overcomes the AFM interactions between the [Formula: see text] cores. A transition to a more distorted phase is observed at T ≈ 500 K and signatures of localization of the eg electrons appear in the χ(T) behaviour below 300 K. A new Curie-Weiss regime is observed, where the Curie-constant value is consistent with dimer formation. Based on mean-field calculations, the dimer formation is predicted as a function of the interaction strength between the t2g and eg electrons.

Serum albumin contamination of cells cultured in vitro significantly impedes the mass spectrometric analysis of proteins secreted by the cells. Here we report a novel washing and culturing technique for rat vascular endothelial cells that considerably reduces the concentration of the commonly used additive for cell culture, bovine serum albumin (BSA), in the secretome of these cells. Cells are rinsed stringently and cultured for 24 h in serum-free media without appreciably impeding cell growth or viability. The percentage of BSA scans identified by tandem mass spectrometry (LC-MS/MS) in stringently rinsed cells (average 13.2%) was significantly lower than either the moderately rinsed or no rinse cell treatments (average 35.2% and 45.2% respectively). Furthermore, the stringent wash treatment allowed the confident identification of a larger portion of the secretome of rat endothelial cells by LC-MS/MS.

The hospital records of 1687 psychiatric patients were rated for the presence of assaultive or other fear-inducing behaviors associated with the reasons for their hospital admissions. Data analyses indicated that significant associations existed between these behaviors and sex, race/ethnicity, diagnosis, previous admissions, referral source for hospitalization, legal status at admission, and legal status at discharge. No associations were found for age, education, marital status, employment status, number of days hospitalized during the index hospitalization, and referral at discharge. A comparison of these results with the results of studies by other investigators led to the conclusion that clinical variables appear to have a more consistent relation to violent behavior than demographic variables. Future research examining for the correlates of violent behavior in psychiatric patients may be more productive by focusing on the type and degree of patients' psychopathologies rather than on patients' demographic characteristics.

Recent studies indicate that the incidence of violent or fear-inducing behavior among the mentally ill may be higher than once thought. In this study, medical record admission notes for 1,687 psychiatric patients over a four-year period were examined for indications that the patients had engaged in violent or fear-inducing behavior just prior to hospital admission. This and other studies suggest that the frequency of violent or fear-inducing behavior associated with psychiatric admissions may have stabilized in recent years. The authors also found a significantly higher level of hospital readmissions for violent patients than for other patients. As a result, they caution against assuming that the rate of violent behavior among hospital admissions accurately reflects the prevalence of violent behavior among the general population of the mentally ill.