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Photocatalysis is a potential technology to produce hydrogen peroxide with low energy consumption and no pollution. However, when using traditional photocatalysts it is hard to meet the requirements of wide visible light absorption, high carrier separation rate and sufficient active sites. Graphitic carbon nitride (g-C3N4) has great potential in the photocatalytic production of hydrogen peroxide, but its photocatalytic performance is limited by a high carrier recombination ratio. Here, we fabricated the Z-Scheme heterojunction of C3N4/Ti3C2/CdS in situ. The large specific surface area of C3N4 can provide plenty of reactive sites, and the absorption efficiency under visible light is improved with the addition of Ti3C2 and CdS. The better conductivity of Ti3C2 reduces the charge transfer resistance. With the increase of surface charge carriers, the width of the space charge region decreases and the photocurrent density increases significantly. Under visible light irradiation, the H2O2 yield of the ternary photocatalyst reaches 256 µM L-1 h-1, which is about 6 times that of pristine C3N4. After three cycles, the high photocatalytic efficiency can still be maintained. In this paper, the reaction mechanism of photocatalytic hydrogen peroxide production by the C3N4/Ti3C2/CdS composite material is proposed through an in-depth study of energy band theory, which provides a new reference for the design and preparation of high-performance materials for photocatalytic hydrogen peroxide production.
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Recent experiments demonstrated that interfacial water dissociation (H2O â H+ + OH-) could be accelerated exponentially by an electric field applied to graphene electrodes, a phenomenon related to the Wien effect. Here we report an order-of-magnitude acceleration of the interfacial water dissociation reaction under visible-light illumination. This process is accompanied by spatial separation of protons and hydroxide ions across one-atom-thick graphene and enhanced by strong interfacial electric fields. The found photoeffect is attributed to the combination of graphene's perfect selectivity with respect to protons, which prevents proton-hydroxide recombination, and to proton transport acceleration by the Wien effect, which occurs in synchrony with the water dissociation reaction. Our findings provide fundamental insights into ion dynamics near atomically thin proton-selective interfaces and suggest that strong interfacial fields can enhance and tune very fast ionic processes, which is of relevance for applications in photocatalysis and designing reconfigurable materials.
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We experimentally demonstrate an all-fiber, ultraviolet-enhanced, supercontinuum generation in a specifically designed seven-core photonic crystal fiber pumped by a picosecond Yb-doped master oscillator power amplifier (MOPA). The MOPA source is seeded by a giant-chirped Yb-doped mode-locked fiber laser operating in the dissipative-soliton-resonance (DSR) region. The DSR is achieved by using a nonlinear optical loop mirror (NOLM) with a fundamental repetition rate of 4.5 MHz and a central wavelength of 1035 nm. An extremely wide optical spectrum spanning from 350 nm to 2400 nm is obtained with a total output power of 6.86 W.
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We present the results of numerical simulations of dissipative soliton generation using nonlinear Schrödinger equations in an all-normal-dispersion (ANDi) mode-locked fiber laser based on a nonlinear optical loop mirror (NOLM). Firstly, systematic and computationally intensive analysis of the pulse state distributions in two-dimensional parameter spaces of an ANDi fiber laser was conducted. In addition, we determined that unstable non-vanishing regions including pulsation and noise-like pulses are directly related to the saturable absorptions of NOLMs and that two critical filter bandwidths separate those regions from stable ones. Finally, we found that the multi-pulsing power threshold can be maximized by using an optimal optical filter bandwidth.
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Physical pain may lead to aggressive behavior in a social context. However, it is unclear whether this is related to changes of social information processing. Thus, this study aimed to investigate the neural mechanisms underlying pain-induced aggression using functional magnetic resonance imaging. In the experiment, 59 healthy participants were recruited: 31 were treated with topical capsaicin cream (pain group) and 28 with hand cream (control group). Participants completed a social network aggression task, during which they underwent two phases: feedback processing and attack exerting. The results revealed that participants in the pain group exhibited more aggression than those in the control group. During the feedback-processing phase, physical pain reduced brain activation in the right insula, left orbitofrontal cortex and anterior cingulate cortex, which typically exhibited stronger activation in response to negative (and positive) vs neutral social feedback in the control group. However, during the attack-exerting phase, pain did not significantly alter the activation of the dorsolateral prefrontal cortex. These findings suggest that pain increased aggression, while before that, it suppressed brain activities of the salience network involved in the process of salient social information and the value system associated with the value representation of social events.
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Agresión , Encéfalo , Humanos , Retroalimentación , Agresión/fisiología , Encéfalo/fisiología , Corteza Prefrontal/diagnóstico por imagen , Mapeo Encefálico , Dolor , Imagen por Resonancia Magnética/métodosRESUMEN
In recent years, the sustainable livelihood of farmers has been threatened by various events such as the COVID-19 pandemic, which has significantly impacted efforts to alleviate poverty. Therefore, it is vitally important to increase farmers' sustainable livelihood resilience to enhance the stability and sustainability of poverty alleviation efforts. In this study, to scientifically measure and analyze farmers' sustainable livelihood resilience, we designed an analytical framework that captures the characteristics of farmers' sustainable livelihood resilience from the three dimensions of buffer capacity, self-organization capacity, and learning capacity. We then constructed an index system of farmers' sustainable livelihood resilience and a cloud-model-based multi-level fuzzy comprehensive evaluation model. Finally, the coupling coordination degree and decision tree methods were used to identify the level of development and relationships among the three abovementioned dimensions of farmers' sustainable livelihood resilience. A case study from Fugong County, Yunnan Province, China revealed that the spatial and temporal distributions of farmers' sustainable livelihood resilience were heterogeneous across various regions. Furthermore, the spatial distribution of the coordinated development level of farmers' sustainable livelihood resilience is similar to that of its overall level because the three dimensions of buffer capacity, self-organization capacity, and learning capacity interact with each other and develop synergistically, and the lack of any one of these affects the overall development of farmers' sustainable livelihood resilience. In addition, the sustainable livelihood resilience of farmers in various villages is in a state of stable promotion, benign promotion, stagnation, mild recession, severe recession, or chaotic period, indicating a lack of balance in terms of the state of development. However, sustainable livelihood resilience will gradually improve in response to targeted support policies formulated by the national or local governments.
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BACKGROUND: Knee osteoarthritis (KOA) is a common public health problem and a leading cause of long-term pain, decreased muscle strength, and even disability. Tai Chi has been proved effective and highly recommended for KOA management worldwide. However, little is known about its benefits on quadriceps strength which is closely associated with relieving knee pain. This trial is designed to evaluate the efficacy and safety of Tai Chi on knee pain and muscle strength in middle-aged and older adults with KOA. METHODS: A total of 100 participants will be randomly divided into a Tai Chi group (TC group) (1x/week for 12 weeks) and a control group with a health education and stretching program (1x/week for 12 weeks) with a follow-up period of 6 weeks. The primary outcome is the change of Western Ontario and McMaster Universities (WOMAC) pain subscale at week 12 compared with baseline. Secondary outcomes include WOMAC stiffness and function subscales, data from isokinetic dynamometry, gait analysis with electromyography (EMG), and a 36-item short form health survey (SF-36). The daily dose of pain-relieving medication will also be recorded. All adverse effects will be assessed by the Treatment Emergent Symptom Scale (TESS). DISCUSSION: We expect this randomized trial to evaluate the effectiveness of Tai Chi on relieving pain and increasing quadriceps strength in KOA patients. This protocol, if proven effective, will contribute to providing a promising alternative intervention for middle-aged and older adults with KOA. TRIALS REGISTRATION NUMBER: This trial has been registered in the China Clinical Trials Registry (registration number: ChiCTR2300069339).
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Osteoartritis de la Rodilla , Taichi Chuan , Persona de Mediana Edad , Humanos , Anciano , Osteoartritis de la Rodilla/terapia , Resultado del Tratamiento , Dolor , Fuerza Muscular , Ensayos Clínicos Controlados Aleatorios como AsuntoRESUMEN
Thermal homeostasis is vital for mammals and is controlled by brain neurocircuits. Yet, the neural pathways responsible for cold defense regulation are still unclear. Here, we found that a pathway from the lateral parabrachial nucleus (LPB) to the dorsomedial hypothalamus (DMH), which runs parallel to the canonical LPB to preoptic area (POA) pathway, is also crucial for cold defense. Together, these pathways make an equivalent and cumulative contribution, forming a parallel circuit. Specifically, activation of the LPB â DMH pathway induced strong cold-defense responses, including increases in thermogenesis of brown adipose tissue (BAT), muscle shivering, heart rate, and locomotion. Further, we identified somatostatin neurons in the LPB that target DMH to promote BAT thermogenesis. Therefore, we reveal a parallel circuit governing cold defense in mice, which enables resilience to hypothermia and provides a scalable and robust network in heat production, reshaping our understanding of neural circuit regulation of homeostatic behaviors.
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Hipotermia , Termogénesis , Ratones , Animales , Termogénesis/fisiología , Área Preóptica/metabolismo , Vías Nerviosas/fisiología , Homeostasis , Hipotermia/metabolismo , Tejido Adiposo Pardo/metabolismo , Frío , MamíferosRESUMEN
Background: Herniation of the nucleus pulposus caused by disc degeneration and other reasons can cause low back pain and disability. In China, traditional Chinese exercises (TCEs) and traditional Chinese massage (TCM) are widely used to improve symptoms of pain and disability in patients with lumbar disc herniation (LDH). The safety and efficacy of combination therapy have not been studied. Objectives: To assess the effect of traditional Chinese exercise combined with massage vs. traditional Chinese massage alone on pain, disability, lumbar mobility and gait performance in patients with LDH. Methods: Multi-center, randomized clinical trial conducted at 4 hospitals in China and enrolling 272 patients with LDH. Participants were randomly assigned to TCEs plus TCM group or TCM alone group. The combined therapy group received 18 Tai Chi training sessions (30-min sessions 3 times a week) and regular TCM treatments over 6 weeks. The control group received TCM therapy alone and was instructed to maintain their usual daily physical activity. Outcome variables measured included Visual Analog Scale (VAS), Short Form of McGill Pain Questionnaire (SF-MPQ), Oswestry Disability Index (ODI), lumbar spine range of motion (ROM) and gait performance. Results: Among the 272 randomized participants, 259 completed the study. The mean VAS score was 51.77 mm at baseline in the TCEs plus TCM group, and 50.93 mm for the TCM alone group. The reduction in the VAS score at week 6 was greater in the TC group than in the TCM group with a mean difference of 4.05 (95% CI, 2.15-5.95; P < 0.001), and the ODI score with between-group differences of 3.57 points (95% CI, 2.84-4.30 points; P < 0.001). Similar significantly different results were observed in SF-MPQ, walking speed, cadence, and lumbar ROM. No serious adverse events were reported throughout the study period. Conclusion: Compared with TCM alone, TCEs combined with TCM treatment performed better in reducing pain and improving disability. The combination therapy could be considered a valuable treatment option for LDH patients, with potential therapeutic utility for middle-aged and elderly patients with LDH.
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Defect-free graphene is impermeable to gases and liquids but highly permeable to thermal protons. Atomic-scale defects such as vacancies, grain boundaries, and Stone-Wales defects are predicted to enhance graphene's proton permeability and may even allow small ions through, whereas larger species such as gas molecules should remain blocked. These expectations have so far remained untested in experiment. Here, we show that atomically thin carbon films with a high density of atomic-scale defects continue blocking all molecular transport, but their proton permeability becomes â¼1000 times higher than that of defect-free graphene. Lithium ions can also permeate through such disordered graphene. The enhanced proton and ion permeability is attributed to a high density of eight-carbon-atom rings. The latter pose approximately twice lower energy barriers for incoming protons compared to that of the six-atom rings of graphene and a relatively low barrier of â¼0.6 eV for Li ions. Our findings suggest that disordered graphene could be of interest as membranes and protective barriers in various Li-ion and hydrogen technologies.
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In this study, a uniform nanoporous NiO film, with a thickness of up to 2.6 µm, was prepared using polyethylene glycol (PEG). The addition of PEG significantly decreased the cracks in the NiO film and prevented the peeling of the NiO film from a fluorine-doped tin oxide substrate. The NiO cathode was prepared using CdSeS quantum dots (QDs) as the sensitizer, with an optimized photoelectric conversion of 0.80%. The optimized QD-sensitized NiO films were first assembled with the TiO2 anode to prepared QD-sensitized p-n-type tandem solar cells. The open circuit voltage was greater than that obtained using the separated NiO cathode or TiO2 anode.