Rechargeable aqueous Zn-ion batteries (ZIBs) are very promising for large-scale grid energy storage applications owing to their low cost, environmentally benign constituents, excellent safety, and ...relatively high energy density. Their usage, however, is largely hampered by the fast capacity fade. The complexity of the reactions has resulted in long-standing ambiguities of the chemical pathways of Zn/MnO2 system. In this study, we find that both H+/Zn2+ intercalation and conversion reactions occur at different voltages and that the rapid capacity fading can clearly be ascribed to the rate-limiting and irreversible conversion reactions at a lower voltage. By limiting the irreversible conversion reactions at ∼1.26 V, we successfully demonstrate ultrahigh power and long life that are superior to most of the reported ZIBs or even some lithium-ion batteries.
Controlling thermal expansion is an important, not yet resolved, and challenging problem in materials research. A conceptual design is introduced here, for the first time, for the use of ...metal–organic frameworks (MOFs) as platforms for controlling thermal expansion devices that can operate in the negative, zero, and positive expansion regimes. A detailed computer simulation study, based on molecular dynamics, is presented to support the targeted application. MOF-5 has been selected as model material, along with three molecules of similar size and known differences in terms of the nature of host–guest interactions. It has been shown that adsorbate molecules can control, in a colligative way, the thermal expansion of the solid, so that changing the adsorbate molecules induces the solid to display positive, zero, or negative thermal expansion. We analyze in depth the distortion mechanisms, beyond the ligand metal junction, to cover the ligand distortions, and the energetic and entropic effect on the thermo-structural behavior. We provide an unprecedented atomistic insight on the effect of adsorbates on the thermal expansion of MOFs as a basic tool toward controlling the thermal expansion.
Skutterudites CoSb3 with multiple cofillers Ba, La, and Yb were synthesized and very high thermoelectric figure of merit ZT = 1.7 at 850 K was realized. X-ray diffraction of the densified ...multiple-filled bulk samples reveals all samples are phase pure. High-resolution scanning transmission electron microscopy (STEM) and energy dispersive X-ray spectroscopy (EDS) analysis confirm that multiple guest fillers occupy the nanoscale-cages in the skutterudites. The fillers are further shown to be uniformly distributed and the Co−Sb skutterudite framework is virtually unperturbed from atomic scale to a few micrometers. Our results firmly show that high power factors can be realized by adjusting the total filling fraction of fillers with different charge states to reach the optimum carrier density, at the same time, lattice thermal conductivity can also be significantly reduced, to values near the glass limit of these materials, through combining filler species of different rattling frequencies to achieve broad-frequency phonon scattering. Therefore, partially filled skutterudites with multiple fillers of different chemical nature render unique structural characteristics for optimizing electrical and thermal transports in a relatively independent way, leading to continually enhanced ZT values from single- to double-, and finally to multiple-filled skutterudites. The idea of combining multiple fillers with different charge states and rattling frequencies for performance optimization is also expected to be valid for other caged TE compounds.
Scientists and clinicians have traditionally targeted single brain regions with stimulation to modulate brain function and disease. However, brain regions do not operate in isolation, but interact ...with other regions through networks. As such, stimulation of one region may impact and be impacted by other regions in its network. Here we test whether the effects of brain stimulation can be enhanced by simultaneously targeting a region and its network, identified with resting state functional connectivity MRI. Fifteen healthy participants received two types of transcranial direct current stimulation (tDCS): a traditional two-electrode montage targeting a single brain region (left primary motor cortex M1) and a novel eight-electrode montage targeting this region and its associated resting state network. As a control, 8 participants also received multifocal tDCS mismatched to this network. Network-targeted tDCS more than doubled the increase in left M1 excitability over time compared to traditional tDCS and the multifocal control. Modeling studies suggest these results are unlikely to be due to tDCS effects on left M1 itself, however it is impossible to completely exclude this possibility. It also remains unclear whether multifocal tDCS targeting a network selectively modulates this network and which regions within the network are most responsible for observed effects. Despite these limitations, network-targeted tDCS appears to be a promising approach for enhancing tDCS effects beyond traditional stimulation targeting a single brain region. Future work is needed to test whether these results extend to other resting state networks and enhance behavioral or therapeutic effects.
•Resting state functional connectivity can guide multifocal tDCS.•tDCS effects can be enhanced with network-targeted stimulation.•Multifocal tDCS mismatched to a network fails to produce similar effects.
Cognitive-behavioural therapy (CBT) is considered to be effective for the symptoms of schizophrenia. However, this view is based mainly on meta-analysis, whose findings can be influenced by failure ...to consider sources of bias.
To conduct a systematic review and meta-analysis of the effectiveness of CBT for schizophrenic symptoms that includes an examination of potential sources of bias.
Data were pooled from randomised trials providing end-of-study data on overall, positive and negative symptoms. The moderating effects of randomisation, masking of outcome assessments, incompleteness of outcome data and use of a control intervention were examined. Publication bias was also investigated.
Pooled effect sizes were -0.33 (95% CI -0.47 to -0.19) in 34 studies of overall symptoms, -0.25 (95% CI -0.37 to -0.13) in 33 studies of positive symptoms and -0.13 (95% CI -0.25 to -0.01) in 34 studies of negative symptoms. Masking significantly moderated effect size in the meta-analyses of overall symptoms (effect sizes -0.62 (95% CI -0.88 to -0.35) v. -0.15 (95% CI -0.27 to -0.03), P = 0.001) and positive symptoms (effect sizes -0.57 (95% CI -0.76 to -0.39) v. -0.08 (95% CI -0.18 to 0.03), P<0.001). Use of a control intervention did not moderate effect size in any of the analyses. There was no consistent evidence of publication bias across different analyses.
Cognitive-behavioural therapy has a therapeutic effect on schizophrenic symptoms in the 'small' range. This reduces further when sources of bias, particularly masking, are controlled for.
Bismuth compounds are considered relatively non-toxic, with their low solubility in aqueous solutions (e.g., biological fluids) being the major contributing factor to this property. Bismuth ...derivatives are widely used for the treatment of peptic ulcers, functional dyspepsia, and chronic gastritis. Moreover, the properties of bismuth compounds have also been extensively explored in two main fields of action: antimicrobial and anticancer. Despite the clinical interest of bismuth-based drugs, several side effects have also been reported. In fact, excessive acute ingestion of bismuth, or abuse for an extended period of time, can lead to toxicity. However, evidence has demonstrated that the discontinuation of these compounds usually reverses their toxic effects. Notwithstanding, the continuously growing use of bismuth products suggests that it is indeed part of our environment and our daily lives, which urges a more in-depth review and investigation into its possible undesired activities. Therefore, this review aims to update the pharmaco-toxicological properties of bismuth compounds. A special focus will be given to in vitro, in vivo, and clinical studies exploring their toxicity.
Despite advances in cancer therapy, several persistent issues remain. These include cancer recurrence, effective targeting of aggressive or therapy-resistant cancers, and selective treatments for ...transformed cells. This review evaluates the current findings and highlights the potential of targeting the unfolded protein response to treat cancer. The unfolded protein response, an evolutionarily conserved pathway in all eukaryotes, is initiated in response to misfolded proteins accumulating within the lumen of the endoplasmic reticulum. This pathway is initially cytoprotective, allowing cells to survive stressful events; however, prolonged activation of the unfolded protein response also activates apoptotic responses. This balance is key in successful mammalian immune response and inducing cell death in malignant cells. We discuss how the unfolded protein response affects cancer progression, survival, and immune response to cancer cells. The literature shows that targeting the unfolded protein response as a monotherapy or in combination with chemotherapy or immunotherapies increases the efficacy of these drugs; however, systemic unfolded protein response targeting may yield deleterious effects on immune cell function and should be taken into consideration. The material in this review shows the promise of both approaches, each of which merits further research.
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