Atomically dispersed catalysts refer to substrate-supported heterogeneous catalysts featuring one or a few active metal atoms that are separated from one another. They represent an important class of ...materials ranging from single-atom catalysts (SACs) and nanoparticles (NPs). While SACs and NPs have been extensively reported, catalysts featuring a few atoms with well-defined structures are poorly studied. The difficulty in synthesizing such structures has been a critical challenge. Here we report a facile photochemical method that produces catalytic centers consisting of two Ir metal cations, bridged by O and stably bound to a support. Direct evidence unambiguously supporting the dinuclear nature of the catalysts anchored on α-Fe₂O₃ is obtained by aberration-corrected scanning transmission electron microscopy (AC-STEM). Experimental and computational results further reveal that the threefold hollow binding sites on the OH-terminated surface of α-Fe₂O₃ anchor the catalysts to provide outstanding stability against detachment or aggregation. The resulting catalysts exhibit high activities toward H₂O photooxidation.
Graphene zigzag nanoribbons, initially in a topologically ordered state, undergo a topological phase transition into crossover phases distinguished by quasi-topological order. We computed mutual ...information for both the topologically ordered phase and its crossover phases, revealing the following results: (i) In the topologically ordered phase, A-chirality carbon lines strongly entangle with B-chirality carbon lines on the opposite side of the zigzag ribbon. This entanglement persists but weakens in crossover phases. (ii) The upper zigzag edge entangles with non-edge lines of different chirality on the opposite side of the ribbon. (iii) Entanglement increases as more carbon lines are grouped together, regardless of the lines’ chirality. No long-range entanglement was found in the symmetry-protected phase in the absence of disorder.
Summary
Medication persistence and adherence are critical for osteoporosis outcomes. Using the Taiwan National Health Insurance Research Database, we found that persistence and adherence to ...teriparatide were low in Taiwanese patients with osteoporosis and that greater persistence and adherence were associated with a lower incidence of hip and other nonvertebral fractures.
Introduction
The purpose of this study was to determine the persistence and adherence to teriparatide treatment in Taiwanese patients with osteoporosis, and to examine the association between persistence and adherence to teriparatide with fracture risks.
Methods
Medical and pharmacy claims for 4,692 patients with vertebral or hip fractures and teriparatide prescriptions between 2005 and 2008 were identified (Taiwan National Health Insurance Research Database). Persistence was the time from the start of treatment to the first 90-day gap between two teriparatide prescriptions. Adherence was the number of teriparatide pens (each pen is used over 1 month) prescribed over 24 months. Association of persistence and adherence to teriparatide with fracture incidence was assessed using adjusted Cox proportional hazards models.
Results
The proportion of patients persisting with teriparatide for >6 months and >12 months was 44.6 and 24.9 %, respectively. Over 24 months, 53.6 % of patients were adherent for >6 months and 33.9 % were adherent for >12 months. Patients persisting for >12 months had a significantly lower incidence of hip (adjusted hazard ratio HR, 0.61 95 % confidence interval (CI), 0.40–0.93,
P
= 0.0229) and nonvertebral fracture (HR, 0.79 95 % CI, 0.63–0.99,
P
= 0.0462) compared with those who persisted for ≤12 months. Patients adherent for >12 months had a lower incidence of hip (HR, 0.66 95 % CI, 0.46–0.96,
P
= 0.0286) and nonvertebral fracture (HR, 0.81 95 % CI, 0.66–0.99,
P
= 0.0377) compared with those adherent for ≤12 months.
Conclusions
Persistence and adherence to teriparatide over 24 months were low in Taiwanese patients with osteoporosis; greater adherence and persistence were associated with a lower incidence of nonvertebral fractures.
The behavior of crystalline nanoparticles depends strongly on which facets are exposed. Some facets are more active than others, but it is difficult to selectively isolate particular facets. This ...study provides fundamental insights into photocatalytic and photoelectrochemical performance of three types of TiO2 nanoparticles with predominantly exposed {101}, {010}, or {001} facets, where 86–99% of the surface area is the desired facet. Photodegradation of methyl orange reveals that {001}-TiO2 has 1.79 and 3.22 times higher photocatalytic activity than {010} and {101}-TiO2, respectively. This suggests that the photochemical performance is highly correlated with the surface energy and the number of under-coordinated surface atoms. In contrast, the photoelectrochemical performance of the faceted TiO2 nanoparticles sensitized with the commercially available MK-2 dye was highest with {010}-TiO2 which yielded an overall cell efficiency of 6.1%, compared to 3.2% for {101}-TiO2 and 2.6% for {001}-TiO2 prepared under analogous conditions. Measurement of desorption kinetics and accompanying computational modeling suggests a stronger covalent interaction of the dye with the {010} and {101} facets compared with the {001} facet. Time-resolved THz spectroscopy and transient absorption spectroscopy measure faster electron injection dynamics when MK-2 is bound to {010} compared to other facets, consistent with extensive computational simulations which indicate that the {010} facet provides the most efficient and direct pathway for interfacial electron transfer. Our experimental and computational results establish for the first time that photoelectrochemical performance is dependent upon the binding energy of the dye as well as the crystalline structure of the facet, as opposed to surface energy alone.
Cancer is one of the leading causes of death, with a heavy socio-economical burden for countries. Despite the great advances that have been made in the treatment of cancer, chemotherapy is still the ...most common method of treatment. However, many side effects, including hepatotoxicity, renal toxicity, and cardiotoxicity, limit the efficacy of conventional chemotherapy. Over recent years, natural products have attracted attention as therapeutic agents against various diseases, such as cancer. Resveratrol (RES), a natural polyphenol occurring in grapes, nuts, wine, and berries, exhibited potential for preventing and treating various cancer types. RES also ameliorates chemotherapy-induced detrimental effects. Furthermore, RES could modulate apoptosis and autophagy as the main forms of cancer cell deaths by targeting various signaling pathways and up/downregulation of apoptotic and autophagic genes. This review will summarize the anti-cancer effects of RES and focus on the fundamental mechanisms and targets for modulating apoptosis and autophagy by RES.
Particle science and technology is a rapidly developing interdisciplinary research area with its core being the understanding of the relationships between micro- and macroscopic properties of ...particulate/granular matter—a state of matter that is widely encountered but poorly understood. The macroscopic behaviour of particulate matter is controlled by the interactions between individual particles as well as interactions with surrounding fluids. Understanding the microscopic mechanisms in terms of these interaction forces is therefore key to leading to truly interdisciplinary research into particulate matter and producing results that can be generally used. This aim can be effectively achieved via particle scale research based on detailed microdynamic information such as the forces acting on and trajectories of individual particles in a considered system. In recent years, such research has been rapidly developed worldwide, mainly as a result of the rapid development of discrete particle simulation technique and computer technology. This paper reviews the work in this area with special reference to the discrete element method and associated theoretical developments. It covers three important aspects: models for the calculation of the particle–particle and particle–fluid interaction forces, coupling of discrete element method with computational fluid dynamics to describe particle–fluid flow, and the theories for linking discrete to continuum modelling. Needs for future development are also discussed.
In this Letter, the authors present a reconfigurable power divider using a hybrid matrix with variable impedance tuners. The proposed hybrid matrix-based power divider with varactor-tuned impedance ...tuners (VTITs) can simultaneously obtain variable power-dividing ratios at the centre frequency and variable operating frequencies for the 3 dB coupling states. The VTITs, consisting of a transmission line, an inductor, and a varactor located between the line and the inductor, are connected in parallel between two hybrid couplers for high impedance variation. Measured results demonstrate that the power-dividing ratio of the proposed divider varies from −14.3 to 13.3 dB with a return loss above 20 dB and the isolation above 20 dB at a centre frequency of 2.45 GHz. Moreover, it achieves an insertion loss of 0.7–1.45 dB and a phase variation of less than 8° across the variable power-dividing ratio at the centre frequency. The frequency-tuning range for the 3 dB coupling states is 750 MHz with a small phase variation of 5°.
Relatively little is known about neurobiological changes attributable to early-life stressors (e.g., orphanage rearing), even though they have been associated with a heightened risk for later ...psychopathology. Human neuroimaging and animal studies provide complementary insights into the neural basis of problem behaviors following stress, but too often are limited by dissimilar experimental designs. The current mouse study manipulates the type and timing of a stressor to parallel the early-life stress experience of orphanage rearing, controlling for genetic and environmental confounds inherent in human studies. The results provide evidence of both early and persistent alterations in amygdala circuitry and function following early-life stress. These effects are not reversed when the stressor is removed nor diminished with the development of prefrontal regulation regions. These neural and behavioral findings are similar to our human findings in children adopted from orphanages abroad in that even following removal from the orphanage, the ability to suppress attention toward potentially threatening information in favor of goal-directed behavior was diminished relative to never-institutionalized children. Together, these findings highlight how early-life stress can lead to altered brain circuitry and emotion dysregulation that may increase the risk for psychopathology.
Highlights • Diabetes increases the lipid peroxidation of the hippocampus of rats. • Diabetes promotes the IKKβ/NF-κB activation and inflammatory level. • Diabetes impairs insulin signaling by ...suppressing PI3K/AKT activities. • Dietary fish oil prevents the alterations in diabetes and improves cognitive ability.
A study using 144 one-day-old Arbor Acres broilers was conducted to assess the effects of dried ginger root (Zingiber officinale) that was processed to particle sizes of 300, 149, 74, 37, and 8.4 μm ...on growth performance, antioxidant status, and serum metabolites of broiler chickens. The birds were housed in 24 wire cages in an environmentally controlled room. Dietary treatments were no supplementation (control) and supplementation with ginger root processed to 5 particle sizes at the level of 5 g/kg of diet. Average daily gain, ADFI, and feed conversion rate of chicks of each cage were measured weekly. Blood samples from 8 broilers per treatment were obtained at d 21 and 42 of the experiment to determine antioxidant enzymatic activities and metabolites in the serum, and the birds were subsequently killed to determine carcass yield and abdominal fat content. All broilers had similar ADFI or feed conversion rate over the entire experimental period. However, broilers supplemented with ginger powder tended to have higher ADG and had greater (P = 0.014) carcass yield compared with that of the control. Supplementation of ginger increased (P < 0.001) activities of total superoxide dismutase and glutathione peroxidase but reduced (P < 0.01) concentrations of malondialdehyde and cholesterol in serum of broilers at 21 and 42 d of age. Concentration of total protein in serum of ginger-supplemented broilers tended (P = 0.092) to be higher at 21 d and was higher (P = 0.002) at 42 d of age compared with that of control broilers. Reducing particle size of ginger powder linearly reduced (P < 0.05) cholesterol (d 21) and linearly increased (P < 0.05) glutathione peroxidase (d 21), total superoxide dismutase (d 42), and total protein (d 21 and 42). Supplementation of ginger at the level of 5 g/kg improved antioxidant status of broilers and the efficacy was enhanced as the particle size was reduced from 300 to 37 μm.
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