High-energy Li1.17Ni0.19Co0.10Mn0.54O2 (HE-NCM) is a lithium-rich layered oxide with alternating Li- and transition-metal (TM) layers in which excess lithium ions replace transition metals in the ...host structure. HE-NCM offers a capacity roughly 50 mAh g–1 higher compared to that of conventional layered oxides but suffers from capacity loss and voltage fade upon cycling. Differential capacity plots (taken over 100 cycles) show that the origin of the fading phenomenon is a bulk issue rather than a surface degradation. Although previous studies indicate only minor changes in the bulk material, long duration in situ synchrotron X-ray powder diffraction measurements, in combination with difference Fourier analysis of the data, revealed an irreversible transition-metal motion within the host structure. The extensive work provides new insights into the fading mechanism of the material.
The electrochemical synthesis of ammonia from nitrogen under mild conditions using renewable electricity is an attractive alternative
to the energy-intensive Haber-Bosch process, which dominates ...industrial ammonia production. However, there are considerable scientific and technical challenges
facing the electrochemical alternative, and most experimental studies reported so far have achieved only low selectivities and conversions. The amount of ammonia produced is usually so small that it cannot be firmly attributed to electrochemical nitrogen fixation
rather than contamination from ammonia that is either present in air, human breath or ion-conducting membranes
, or generated from labile nitrogen-containing compounds (for example, nitrates, amines, nitrites and nitrogen oxides) that are typically present in the nitrogen gas stream
, in the atmosphere or even in the catalyst itself. Although these sources of experimental artefacts are beginning to be recognized and managed
, concerted efforts to develop effective electrochemical nitrogen reduction processes would benefit from benchmarking protocols for the reaction and from a standardized set of control experiments designed to identify and then eliminate or quantify the sources of contamination. Here we propose a rigorous procedure using
N
that enables us to reliably detect and quantify the electrochemical reduction of nitrogen to ammonia. We demonstrate experimentally the importance of various sources of contamination, and show how to remove labile nitrogen-containing compounds from the nitrogen gas as well as how to perform quantitative isotope measurements with cycling of
N
gas to reduce both contamination and the cost of isotope measurements. Following this protocol, we find that no ammonia is produced when using the most promising pure-metal catalysts for this reaction in aqueous media, and we successfully confirm and quantify ammonia synthesis using lithium electrodeposition in tetrahydrofuran
. The use of this rigorous protocol should help to prevent false positives from appearing in the literature, thus enabling the field to focus on viable pathways towards the practical electrochemical reduction of nitrogen to ammonia.
Sulfur is an underused by‐product of the petrochemicals industry. Recent research into inverse vulcanization has shown how this excess sulfur can be transformed into functional polymers, by ...stabilization with organic crosslinkers. For these interesting new materials to realize their potential for applications, more understanding and control of their physical properties is needed. Here we report four new terpolymers prepared from sulfur and two distinct alkene monomers that can be predictively tuned in glass transition, molecular weight, solubility, mechanical properties, and color.
Strengthening, altering and controlling the properties of inverse vulcanized sulfur polymers is of great importance. Over 60 million tons of sulfur are produced in excess by the petrochemical industry, and the potential applications of sulfur polymers are widespread. We investigate the mechanical properties and create a library of sulfur terpolymers.
Although most neurophysiological studies of persons with cerebral palsy (CP) have been focused on supraspinal networks, recent evidence points toward the spinal cord as a central contributor to their ...motor impairments. However, it is unclear if alterations in the spinal pathways are also linked to deficits in the sensory processing observed clinically. This investigation aimed to begin to address this knowledge gap by evaluating the flexor carpi radialis (FCR) H-reflex in adults with CP and neurotypical (NT) controls while at rest and during an isometric wrist flexion task. The maximal H-wave (Hmax) and M-wave (Mmax) at rest were calculated and utilized to compute Hmax/Mmax ratios (H:M ratios). Secondarily, the facilitation of the H-wave was measured while producing an isometric, voluntary wrist flexion contraction (i.e., active condition). Finally, a wrist position sense test was used to quantify the level of joint position sense. These results revealed that the adults with CP had a lower H:M ratio compared with the NT controls while at rest. The adults with CP were also unable to facilitate their H-reflexes with voluntary contraction and had greater position sense errors compared with the controls. Further, these results showed that the adults with CP that had greater wrist position sense errors tended to have a lower H:M ratio at rest. Overall, these findings highlight that aberration in the spinal cord pathways of adults with CP might play a role in the sensory processing deficiencies observed in adults with CP.
Endometrial cancer is the sixth commonest cancer in women worldwide, with over 417,000 diagnoses in 2020. The disease incidence has increased by 132% over the last 30 years and is set to continue to ...rise in response to an ageing population and increasing global rates of obesity and diabetes. A greater understanding of the mechanisms driving endometrial carcinogenesis has led to the identification of potential strategies for primary disease prevention, although prospective evaluation of their efficacy within clinical trials is still awaited. The early diagnosis of endometrial cancer is associated with improved survival, but has historically relied on invasive endometrial sampling. New, minimally invasive tests using protein and DNA biomarkers and cytology have the potential to transform diagnostic pathways and to allow for the surveillance of high-risk populations. The molecular classification of endometrial cancers has been shown to not only have a prognostic impact, but also to have therapeutic value and is increasingly used to guide adjuvant treatment decisions. Advanced and recurrent disease management has also been revolutionised by increasing the use of debulking surgery and targeted treatments, particularly immunotherapy. This review summarises the recent advances in the prevention, diagnosis and treatment of endometrial cancer and seeks to identify areas for future research.
Abstract
We search for an isotropic stochastic gravitational-wave background (GWB) in the 12.5 yr pulsar-timing data set collected by the North American Nanohertz Observatory for Gravitational Waves. ...Our analysis finds strong evidence of a stochastic process, modeled as a power law, with common amplitude and spectral slope across pulsars. Under our fiducial model, the Bayesian posterior of the amplitude for an
f
−2/3
power-law spectrum, expressed as the characteristic GW strain, has median 1.92 × 10
−15
and 5%–95% quantiles of 1.37–2.67 × 10
−15
at a reference frequency of
f
yr
=
1
yr
−
1
;
the Bayes factor in favor of the common-spectrum process versus independent red-noise processes in each pulsar exceeds 10,000. However, we find no statistically significant evidence that this process has quadrupolar spatial correlations, which we would consider necessary to claim a GWB detection consistent with general relativity. We find that the process has neither monopolar nor dipolar correlations, which may arise from, for example, reference clock or solar system ephemeris systematics, respectively. The amplitude posterior has significant support above previously reported upper limits; we explain this in terms of the Bayesian priors assumed for intrinsic pulsar red noise. We examine potential implications for the supermassive black hole binary population under the hypothesis that the signal is indeed astrophysical in nature.
The source of oxygen to Earth's atmosphere is organic carbon burial, whilst the main sink is oxidative weathering of fossil carbon. However, this sink is to insensitive to counteract oxygen rising ...above its current level of about 21%. Biogeochemical models suggest that wildfires provide an additional regulatory feedback mechanism. However, none have considered how the evolution of different plant groups through time have interacted with this feedback. The Cretaceous Period saw not only super-ambient levels of atmospheric oxygen but also the evolution of the angiosperms, that then rose to dominate Earth's ecosystems. Here we show, using the COPSE biogeochemical model, that angiosperm-driven alteration of fire feedbacks likely lowered atmospheric oxygen levels from ~30% to 25% by the end of the Cretaceous. This likely set the stage for the emergence of closed-canopy angiosperm tropical rainforests that we suggest would not have been possible without angiosperm enhancement of fire feedbacks.
•High incidence of anxiety disorders in people with obesity.•Common neurobiological mechanisms link obesity and mood disorders.•We describe effects of hypercaloric diets during various ...neurodevelopmental periods.•Increased rates of obesity in young people may promote anxiety disorder development.
Obesity is an increasing problem in young people. Childhood obesity and overweight have increased rapidly on a global scale, and have tripled in the past 30 years, to affect approximately one in five children. Diets high in refined fats and sugar are a major contributor to the development of obesity, and the effects of such obesity-inducing hypercaloric diets on brain function may contribute to the high prevalence of anxiety disorders in people with obesity. Anxiety disorders typically emerge in childhood and adolescence, and symptoms often continue into adulthood. Based on this symptomology, we consider anxiety-related behavioral consequences of hypercaloric diets across development. We review research on the effects of hypercaloric dietary manipulations across the lifespan on emotion regulation and the neurobiological mechanisms that underpin these processes. Cumulatively, the findings reveal that gestation and the juvenile/adolescent developmental periods may be early-life windows of vulnerability for developing anxiety in later life due to the augmented effects of these diets on neuroendocrine stress systems and the maturation of neural circuitry supporting emotion regulation.
Return to Learn After Traumatic Brain Injury Dichiaro, Michael; Baker, David; Tlustos, Sarah J
The Pediatric clinics of North America,
06/2023, Letnik:
70, Številka:
3
Journal Article
Recenzirano
A successful return of youth back to school after traumatic brain injury (TBI) is an important aspect of post-injury management. Regardless of the severity of the injury, returning to school is an ...important aspect of improving recovery and outcomes. Often temporary informal school adjustments suffice in supporting children returning to school after concussion. For those with more a significant TBI, often formal school supports and interventions are important. Given the resiliency and recovery often seen after pediatric brain injury, close monitoring, serial evaluations, and fluid supports are important in accurately identifying what specific sequelae require support in the school setting.
Five studies tested the effect of exposure to authoritarian values on positive affect (PA), negative affect (NA), and meaning in life (MIL). Study 1 (N = 1,053) showed that simply completing a ...measure of right-wing authoritarianism (vs. not) prior to rating MIL led to higher MIL. Preregistered Study 2 (N = 1,904) showed that reading speeches by real-world authoritarians (e.g., Adolf Hitler) led to lower PA, higher NA, and higher MIL than a control passage. In preregistered Studies 3 (N = 1,573) and 4 (N = 1,512), Americans read authoritarian, egalitarian, or control messages and rated mood, MIL, and evaluated the passages. Both studies showed that egalitarian messages led to better mood and authoritarian messages led to higher MIL. Study 5 (N = 148) directly replicated these results with Canadians. Aggregating across studies (N = 3,401), moderational analyses showed that meaning in life, post manipulation, was associated with more favorable evaluations of the authoritarian passage. In addition, PA was a stronger predictor of MIL in the egalitarian and control conditions than in the authoritarian condition. Further results showed no evidence that negative mood (or disagreement) spurred the boost in MIL. Implications and future directions are discussed.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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