Objective
The association between knee injury and knee osteoarthritis (OA) is understudied relative to its importance, particularly in younger populations. This study was undertaken to examine the ...association of knee injury with radiographic features of knee OA in military officers, who have a physically demanding profession and high rates of knee injury.
Methods
Participants were recruited in 2015–2017 from an existing program that enrolled 6,452 military officers during 2004–2009. Officers with a history of knee ligament or meniscal injuries (n = 117 via medical record review) were compared to officers with no history of knee injury (n = 143). Bilateral posteroanterior knee radiographs were obtained using a standardized fixed‐flexion positioning frame. All images were read for Kellgren/Lawrence (K/L) grade, osteophyte (OST), and joint space narrowing (JSN) scores. Data were analyzed using linear‐risk regression models with generalized estimating equations.
Results
Injured and noninjured participants were similar (mean age 28 years, mean body mass index 25 kg/m2, ~40% female). The mean time from first knee injury to imaging among injured participants was 9.2 years. Compared with noninjured knees, greater prevalence of radiographic OA (K/L grade ≥ 2), OST (grade ≥ 1), and JSN (grade ≥ 1) was observed among injured knees, with prevalence differences of +16% (95% confidence interval 95% CI 10%, 22%), +29% (95% CI 20%, 38%), and + 17% (95% CI 10%, 24%), respectively. Approximately 1 in 6 officers with prior knee injury progressed to radiographic OA by age 30 years.
Conclusion
At the midpoint of a projected 20‐year military career, officers with a history of traumatic knee injury have a markedly increased prevalence of knee radiographic OA compared to officers without injury.
•A modelling study for diffusion of hydrogen with traps is presented.•Hydrogen permeation cannot be described by a constant effective diffusivity.•Diffusivity depends widely on hydrogen concentration ...and traps.•Charging and discharging process show asymmetry.
Hydrogen permeation (diffusion) is strongly influenced by the local hydrogen concentration and by the density and depth of traps. Consequently hydrogen diffusion cannot be described by a constant effective diffusivity as suggested in standards and several papers.
A modelling study for diffusion of hydrogen in metals with traps is presented. Simulations are performed for a charging and discharging process, showing a remarkable asymmetry. The actual chemical diffusivity ranges over several orders of magnitude depending on the hydrogen concentration as well as the density and depth of traps. Consequently, the concept of effective diffusivity outlined in standards and many publications fails.
A new model for the evolution of the precipitate structure derived by means of application of the thermodynamic extremum principle is presented. The model describes the evolution of the radii and of ...the chemical composition of individual precipitates of different phases in the multi-component system. In connection with a proper theory of nucleation, the model is able to describe the evolution of the precipitate structure in the classical stages of nucleation, growth and coarsening as well as interaction of precipitates of different phases, of different chemical composition and of different sizes via diffusion in the matrix.
We report on the detection of X-ray polarisation in the black-hole X-ray binary Swift J1727.8−1613 during its dim hard spectral state by the Imaging X-ray Polarimetry Explorer (IXPE). This is the ...first detection of X-ray polarisation at the transition from the soft to the hard state in an X-ray binary. We find an averaged 2–8 keV polarisation degree of (3.3 ± 0.4)% and a corresponding polarisation angle of 3° ±4°, which matches the polarisation detected during the rising stage of the outburst, in September–October 2023, within 1 σ uncertainty. The observational campaign complements previous studies of this source and enables comparison of the X-ray polarisation properties of a single transient across the X-ray hardness-intensity diagram. The complete recovery of the X-ray polarisation properties, including the energy dependence, came after a dramatic drop in the X-ray polarisation during the soft state. The new IXPE observations in the dim hard state at the reverse transition indicate that the accretion properties, including the geometry of the corona, appear to be strikingly similar to the bright hard state during the outburst rise despite the X-ray luminosities differing by two orders of magnitude.
A series of new zirconium and titanium phosphates-organophosphonates, in which the organophosphonate moiety is functionalized with a sulfo group, was prepared by a topotactic reaction involving the ...gamma modification of zirconium or titanium hydrogen phosphate with 2-bis(phosphonomethyl)amino-ethan-1-sulfonic acid (H4TDP). H4TDP represents a new type of functionalizing agent, which can be easily prepared by a Moedritzer–Irani reaction from taurine (2-aminoethanesulfonic acid). The gamma modification of zirconium hydrogen phosphate (γ-ZrP) with H4TDP provides mixed phosphate-organophosphonate compounds with the formula Zr(PO4)(H2PO4)1–2x (H2TDP) x ·yH2O, where x = 0.15, 0.34, 0.45, and is controlled by the γ-ZrP/H4TDP ratio in the starting mixture. On the contrary, by the topotactic gamma modification of titanium hydrogen phosphate (γ-TiP) with H4TDP, only one product with the formula Ti(PO4)(H2PO4)1–2z (H2TDP) z ·yH2O, where z = 0.41 ± 0.01, was obtained regardless of the composition of the starting mixture. The synthesized compounds were characterized by elemental analysis, thermogravimetric analysis, energy-dispersive X-ray analysis, and infrared spectroscopy. The way the topotactic reaction proceeds and how the grafted organophosphonate groups are bonded to the layers of the host structure were suggested on the basis of the solid-state NMR data. It was found that the grafted moieties are spread evenly in the host layers among the hydrogen phosphate groups. The obtained solids are able to intercalate basic molecules, as was proved by the intercalation reactions of the zirconium series with butylamine. The amount of intercalated butylamine increases with increasing x. It is known that both host compounds, γ-ZrP and γ-TiP, are protonic conductors. It was found that the incorporation of H2TDP increases conductivity of the zirconium compound when x = 0.15, but further incorporation of H2TDP into the γ-ZrP host structure leads to a decrease of conductivity. This behavior is explained on the basis of the 1H MAS and the 1H–1H EXSY NMR data.
Circumcision Is Unethical and Unlawful Svoboda, J. Steven; Adler, Peter W.; Van Howe, Robert S.
The Journal of law, medicine & ethics,
06/2016, Letnik:
44, Številka:
2
Journal Article
Recenzirano
The foreskin is a complex structure that protects and moisturizes the head of the penis, and, being the most densely innervated and sensitive portion of the penis, is essential to providing the ...complete sexual response. Circumcision—the removal of this structure—is non-therapeutic, painful, irreversible surgery that also risks serious physical injury, psychological sequelae, and death. Men rarely volunteer for it, and increasingly circumcised men are expressing their resentment about it.
Circumcision is usually performed for religious, cultural and personal reasons. Early claims about its medical benefits have been proven false. The American Academy of Pediatrics and the Centers for Disease Prevention and Control have made many scientifically untenable claims promoting circumcision that run counter to the consensus of Western medical organizations.
Circumcision violates the cardinal principles of medical ethics, to respect autonomy (self-determination), to do good, to do no harm, and to be just. Without a clear medical indication, circumcision must be deferred until the child can provide his own fully informed consent.
In 2012, a German court held that circumcision constitutes criminal assault. Under existing United States law and international human rights declarations as well, circumcision already violates boys› absolute rights to equal protection, bodily integrity, autonomy, and freedom to choose their own religion. A physician has a legal duty to protect children from unnecessary interventions. Physicians who obtain parental permission through spurious claims or omissions, or rely on the American Academy of Pediatrics' position, also risk liability for misleading parents about circumcision.
Context. X-ray reflection off the accretion disc surrounding a black hole, together with the associated broad iron Kα line, has been widely used to constrain the innermost accretion-flow geometry and ...black hole spin. Some recent measurements have revealed steep reflection emissivity profiles in a number of active galactic nuclei and X-ray binaries. Aims. We explore the physically motivated conditions that give rise to the observed steep disc-reflection emissivity profiles. Methods. We perform a set of simulations based on the configuration of a possible future high-resolution X-ray mission. Computations are carried out for typical X-ray bright Seyfert-1 galaxies. Results. We find that steep emissivity profiles with q ~ 4−5 (where the emissivity is ϵ(r) ∝ r−q) are produced considering either i) a lamp-post scenario where a primary compact X-ray source is located close to the black hole, or ii) the radial dependence of the disc ionisation state. If both effects are taken into account, emissivity profiles as steep as q ~ 7 can be obtained from X-ray spectra modelled via conventional reflection models. We also highlight the role of the reflection angular emissivity: the radial emissivity index q is overestimated when the standard limb-darkening law is used to describe the data. Conclusions. Very steep emissivity profiles with q ≥ 7 are naturally obtained by applying reflection models that take into account the radial profile ξ(r) of the disc ionisation induced by a compact X-ray source located close to the central black hole.
Context. Fairall 51 is a polar-scattered Seyfert 1 galaxy, a type of active galaxy believed to represent a bridge between unobscured type-1 and obscured type-2 objects. Fairall 51 has shown complex ...and variable X-ray absorption, but little is known about its origin. Aims. In our research, we observed Fairall 51 with the X-ray satellite Suzaku in order to constrain a characteristic time scale of its variability. Methods. We performed timing and spectral analysis of four observations separated by 1.5, 2, and 5.5 day intervals. Results. We found that the 0.5–50 keV broadband X-ray spectra are dominated by a primary power-law emission (with the photon index ~2). This emission is affected by at least three absorbers with different ionisations (log ξ ≈ 1–4). The spectrum is shaped further by a reprocessed emission, possibly coming from two regions, the accretion disc and a more distant scattering region. The accretion disc emission is smeared by the relativistic effects, from which we measured the spin of the black hole as a ≈ 0.8 ± 0.2. We found that most of the spectral variability can be attributed to the least ionised absorber whose column density changed by a factor of two between the first (highest-flux) and the last (lowest-flux) observation. Conclusions. A week-long scale of the variability indicates that the absorber is located at the distance ≈0.05 pc from the centre, i.e., in the broad line region.
Background:
Approximately half of concussions go undisclosed and therefore undiagnosed. Among diagnosed concussions, 51% to 64% receive delayed medical care. Understanding the influence of ...undiagnosed concussions and delayed medical care would inform medical and education practices.
Purpose:
To compare postconcussion longitudinal clinical outcomes among (1) individuals with no concussion history, all previous concussions diagnosed, and ≥1 previous concussion undiagnosed, as well as (2) those who have delayed versus immediate symptom onset, symptom reporting, and removal from activity after concussion.
Study Design:
Cohort study; Level of evidence, 2.
Methods:
Participants included 2758 military academy cadets and intercollegiate athletes diagnosed with concussion in the CARE Consortium. We determined (1) each participant’s previous concussion diagnosis status self-reported at baseline (no history, all diagnosed, ≥1 undiagnosed) and (2) whether the participant had delayed or immediate symptom onset, symptom reporting, and removal from activity. We compared symptom severities, cognition, balance, and recovery duration at baseline, 24 to 48 hours, date of asymptomatic status, and date of unrestricted return to activity using tests of parallel profiles.
Results:
The ≥1 undiagnosed concussion group had higher baseline symptom burdens (P < .001) than the other 2 groups and poorer baseline verbal memory performance (P = .001) than the all diagnosed group; however, they became asymptomatic and returned to activity sooner than those with no history. Cadets/athletes who delayed symptom reporting had higher symptom burdens 24 to 48 hours after injury (mean ± SE; delayed, 28.8 ± 0.8; immediate, 20.6 ± 0.7), took a median difference of 2 days longer to become asymptomatic, and took 3 days longer to return to activity than those who had immediate symptom reporting. For every 30 minutes of continued participation after injury, days to asymptomatic status increased 8.1% (95% CI, 0.3%-16.4%).
Conclusion:
Clinicians should expect that cadets/athletes who delay reporting concussion symptoms will have acutely higher symptom burdens and take 2 days longer to become asymptomatic. Educational messaging should emphasize the clinical benefits of seeking immediate care for concussion-like symptoms.
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