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Bi3+ doped Ti/Sb-SnO2/PbO2 electrode materials were fabricated by electrodeposition to improve their electrochemical performance in zinc electrowinning. The surface morphology, chemical composition, and hydrophilicity of the as-prepared electrodes were characterized using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and contact angle. An electrochemical measurement and an accelerated lifetime experiment were also conducted to investigate the electrocatalytic performance and stability of the electrodes. The results show that the Bi3+ modification electrode has an important effect on the coating morphology, the crystal structure, the surface hydrophilicity, the electrocatalytic activity, and the stability. The electrode prepared from the solution containing 2 mmol·L-1 Bi(NO3)3 (marked as the Ti/Sb-SnO2/2Bi-PbO2 electrode) exhibits the best hydrophilicity performance (θ = 21.6°) and the longest service life (1196 h). During the electrochemical characterization analysis, the Ti/Sb-SnO2/2Bi-PbO2 electrode showed the highest oxygen evolution activity, which can be attributed to it having the highest electroactive surface (qT* = 21.20 C·cm-2) and the best charge-transfer efficiency. The DFT calculation demonstrated that the doping of Bi3+ leads to a decrease in the OER reaction barrier and an increase in the DOS of the electrode, which further enhances the catalytic activity and the conductivity of the electrode. Moreover, the simulated zinc electrowinning experiment demonstrated that the Ti/Sb-SnO2/2Bi-PbO2 electrode consumes less energy than other electrodes. Therefore, it is expected that the Bi3+ modified electrode will become a very promising electrode material for zinc electrowinning in the future.
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Eye gaze can be a potentially fast and ergonomic method for target selection in augmented reality (AR). However, the eye-tracking accuracy of current consumer-level AR systems is limited. While state-of-the-art AR target selection techniques based on eye gaze and touch (gaze-touch), which follow the "eye gaze pre-selects, touch refines and confirms" mechanism, can significantly enhance selection accuracy, their selection speeds are usually compromised. To balance accuracy and speed in gaze-touch grid menu selection in AR, we propose the Hand-Held Sub-Menu (HHSM) technique.tou HHSM divides a grid menu into several sub-menus and maps the sub-menu pointed to by eye gaze onto the touchscreen of a hand-held device. To select a target item, the user first selects the sub-menu containing it via eye gaze and then confirms the selection on the touchscreen via a single touch action. We derived the HHSM technique's design space and investigated it through a series of empirical studies. Through an empirical study involving 24 participants recruited from a local university, we found that HHSM can effectively balance accuracy and speed in gaze-touch grid menu selection in AR. The error rate was approximately 2%, and the completion time per selection was around 0.93 s when participants used two thumbs to interact with the touchscreen, and approximately 1.1 s when they used only one finger.
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Realidad Aumentada , Humanos , Interfaz Usuario-Computador , Fijación Ocular , Ergonomía , Sistemas de ComputaciónRESUMEN
P2X7 receptor (P2X7R) is highly expressed on immune cells, triggering the release of cytokines and regulating autoimmune responses. To investigate P2X7R surface expression on T helper (Th) 1, Th17, and regulatory T (Treg) cells in patients with systemic lupus erythematosus (SLE) or rheumatoid arthritis (RA) and correlations with disease activity, 29 SLE and 29 RA patients and 18 healthy controls (HCs) were enrolled. We showed that SLE and RA patients had significantly higher levels of plasma cytokines (IFN-γ, IL-1ß, IL-6, IL-17A, and IL-23), frequencies of Th1 and Th17 cells, and expression of P2X7R on Th1 and Th17 than HCs, and the Th17/Treg ratio was significantly increased, whereas Treg cell levels were significantly decreased. The Ca2+ influx increase following BzATP stimulation was significantly higher in CD4+PBMCs from SLE and RA patients than in HCs. Blood levels of shed P2X7R were increased in SLE and RA patients. Furthermore, 28-joint Disease Activity Score and SLE Disease Activity Index score showed negative correlations with Treg cell levels and positive correlations with Th17/Treg ratio and Th17 cell P2X7R expression. Interestingly, Th17 cell P2X7R expression was closely correlated with IL-1ß, C-reactive protein, the erythrocyte sedimentation rate, anticyclic citrullinated peptide Abs, albumin, and C4. These data indicate that increased Th17 cell P2X7R expression is functionally and positively related to disease activity and some inflammatory mediators in SLE and RA patients, and P2X7R could be critical in promoting the Th17 immune response and contributing to the complex pathogenesis of SLE and RA.
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Artritis Reumatoide/inmunología , Lupus Eritematoso Sistémico/inmunología , Receptores Purinérgicos P2X7/metabolismo , Linfocitos T Reguladores/inmunología , Células TH1/inmunología , Células Th17/inmunología , Enfermedad Aguda , Adulto , Anciano , Progresión de la Enfermedad , Femenino , Regulación de la Expresión Génica , Humanos , Masculino , Persona de Mediana Edad , Receptores Purinérgicos P2X7/genéticaRESUMEN
Listeria monocytogenes widely exists in the natural environment and does great harm, which can cause worldwide public safety problem. Infection with L. monocytogenes can cause rapid death of Kupffer cell (KCs) in liver tissue and liver damage. American ginseng saponins is a natural compound in plants, which has great potential in inhibiting L. monocytogenes infection. Therefore, American ginseng stem-leaf saponins (AGS) and American ginseng heat-transformed saponins (HTS) were used as raw materials to study their bacteriostatic experiments in vivo and in vitro. In this experiment, female Kunming mice were randomly divided into five groups: control group, negative group, AGS group, HTS group (10 mg/kg/day in an equal volume via gastric administration) and penicillin group, each group containing six mice. Profiles AGS and HTS components were evaluated by high-performance liquid chromatography (HPLC) analysis. The bacteriostatic effect of AGS and HTS on L. monocytogenes was evaluated by inhibition zone test, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). The bacteriostatic effect of AGS and HTS pretreatment on mice infected with L. monocytogenes were studies by animal experimental. The results showed that the content of polar saponins in AGS was 0.81 ± 0.003 mg/mg, less polar saponins was 0.08 ± 0.02 mg/mg, the content of polar saponins in HTS was 0.10 ± 0.01 mg/mg, less polar saponins was 0.76 ± 0.02 mg/mg. The in vitro bacteriostatic diameter of HTS (16.6 ± 0.8 mm) is large than that of AGS (10.2 ± 1.2 mm). AGS and HTS pretreatment could reduce the colony numbers in the livers of mice infected with Listeria monocytogenes. The levels of alanine aminotransferase (ALT), IL-1ß, IL-6, TNF-α and IFN-γ in the livers of mice in the pretreatment group were significantly lower than those in the negative group. There were obvious leukoplakia, calcification and other liver damage on the liver surface in the negative control group, and obvious inflammatory cell infiltration in HE sections. AGS and HTS pretreatment can reduce liver injury caused by L. monocytogenes and protect the liver. Compared with AGS, HTS has higher content of less polar saponins and better bacteriostatic effect in vitro. The count of bacterial in liver tissue of HTS group was significantly lower, the survival rate was significantly higher than that of AGS group. Less polar saponins had better bacteriostatic effect. Collectively, less polar saponins pretreatment has a protective effect on mice infected with L. monocytogenes, to which alleviated liver damage, improved anti-inflammatory ability and immunity of the body, protected liver may contribute.
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Ginsenósidos/toxicidad , Listeria monocytogenes/efectos de los fármacos , Animales , Femenino , Listeriosis/inmunología , Listeriosis/metabolismo , Listeriosis/microbiología , Listeriosis/veterinaria , Hígado/metabolismo , Ratones , Pruebas de Sensibilidad Microbiana , Estómago , Factor de Necrosis Tumoral alfaRESUMEN
This study introduces an effective method to deposit polypyrrole (PPy) on graphite felt (GF) as anode to improve the start-up performance of microbial fuel cells (MFCs). The results of scanning electron microscope (SEM) and electrochemical testing reveal that polypyrrole is able to improve the electrical conductivity and surface roughness, which is beneficial to the microorganism attachment and growth. It shows that microorganisms grow faster on polypyrrole-modified anode than on unmodified anode. It takes ca. 5 days for polypyrrole-modified anode to reach a reproducible voltage platform, while it takes 11 days for unmodified anode. Moreover, the maximum power density of microbial fuel cells with polypyrrole-modified anode was 919 mW m-2, which were 2.3 times of that with unmodified anode. This research revealed that polypyrrole modification can improve the start-up performance of microbial fuel cells. It is considered as a feasible, economical and sustainable anode.
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Fuentes de Energía Bioeléctrica , Conductividad Eléctrica , Grafito/química , Polímeros/química , Pirroles/química , ElectrodosRESUMEN
In human esophageal squamous cell carcinoma (ESCC), miR-34a was downregulated and could inhibit in vitro cell proliferation and migration. However, the underlying mechanism was not clear yet. The expression levels of mRNA and protein were detected by quantitative real-time PCR or western blotting, respectively. MiR-34a was knocked down or overexpressed and transfected into human ESCC cell lines ECA109 and TE-13, respectively. Cell migration and wound healing assays were used to examine the effect on migration and invasion in vitro. Animal models were used to examine the role of miR-34a in metastasis in vivo. Luciferase assay was carried out to validate the potential target of miR-34a. CD44 was upregulated and miR-34a was downregulated in ESCC tissues and cell lines. The linear regression analysis showed that CD44 expression was negatively correlated with the level of miR-34a. Luciferase assay showed that miR-34a interacted with a putative binding site in the CD44 3'UTR. MiR-34a was found to negatively regulate the expression of CD44. In vitro experiment showed that miR-34a overexpression inhibited ESCC cell invasion and migration; whereas miR-34a knockdown showed reversed results. MiR-34a also inhibited esophagus tumor growth and metastasis in vivo; whereas miR-34a knockdown showed reversed results. Finally, we found that CD44 knockdown reversed the effects of miR-34a knockdown on ESCC cell invasion and migration in vitro. MiRNA-34a suppresses invasion and metastatic in ESCC by regulating CD44.
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Carcinoma de Células Escamosas/metabolismo , Neoplasias Esofágicas/metabolismo , Receptores de Hialuranos/metabolismo , MicroARNs/metabolismo , Proteínas de Neoplasias/metabolismo , ARN Neoplásico/metabolismo , Animales , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/patología , Neoplasias Esofágicas/genética , Neoplasias Esofágicas/patología , Carcinoma de Células Escamosas de Esófago , Femenino , Humanos , Receptores de Hialuranos/genética , Masculino , Ratones , Ratones Desnudos , MicroARNs/genética , Invasividad Neoplásica , Metástasis de la Neoplasia , Proteínas de Neoplasias/genética , ARN Neoplásico/genéticaRESUMEN
A novel bioelectrochemical system (BES) was designed to recover copper and nickel from wastewater sequentially. The BES has two chambers separated by a bipolar membrane and two cathodes. Firstly, the copper ions were reduced on a graphite cathode with electricity output, and then with an additional bias-potential applied, the nickel ions were recovered sequentially on a copper sheet with electricity input. In this design, nickel and copper can be recovered and separated sequentially on two cathodes. By adjusting the molar ratio of copper and nickel ions to 2.99:1 in wastewater, 1.40 mmol Cu²âº could be recovered with 143.78 J electricity outputs, while 50.68 J electricity was input for 0.32 mmol nickel reduction. The total energy output of copper recovery was far more than the electricity input of nickel reduction. The present technology provides a potential method for heavy metal ion separation and recovery.
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Cobre/aislamiento & purificación , Níquel/aislamiento & purificación , Eliminación de Residuos Líquidos/métodos , Cationes , Electricidad , Técnicas Electroquímicas/instrumentación , Electrodos , Eliminación de Residuos Líquidos/instrumentación , Aguas Residuales/química , Contaminantes Químicos del Agua/aislamiento & purificaciónRESUMEN
CONTEXT: Nesfatin-1 is implicated to possess an anti-inflammatory effect. OBJECTIVE: The aim of our study is to investigate whether abnormal serum levels of nesfatin-1 are associated with the presence and severity of preeclampsia. METHODS: A total of 120 women with preeclampsia and 92 women with uncomplicated pregnancies were enrolled in this study. RESULTS: Women with preeclampsia showed significantly reduced levels of serum nesfatin-1 levels than women with uncomplicated pregnancies. Serum nesfatin-1 levels were significantly decreased in women with severe preeclampsia compared with women with mild preeclampsia. CONCLUSION: Decreased serum nesfatin-1 levels are associated with the presence and severity of preeclampsia.
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Proteínas de Unión al Calcio/sangre , Proteínas de Unión al ADN/sangre , Proteínas del Tejido Nervioso/sangre , Preeclampsia/sangre , Adulto , Presión Sanguínea , Diagnóstico Diferencial , Femenino , Humanos , Resistencia a la Insulina , Modelos Lineales , Nucleobindinas , Preeclampsia/diagnóstico , Preeclampsia/fisiopatología , Embarazo , Índice de Severidad de la Enfermedad , Triglicéridos/sangreRESUMEN
Currently, praziquantel is the drug of choice for the treatment of human Schistosoma mansoni infections. It has not been proved until now that there is real praziquantel resistance, but there is decreased praziquantel sensitivity. A search for novel antischistosomal agents against the parasite has been given a high priority. Dihydroartemisinin, formerly identified as an antimalarial drug, has been shown to be active against both Schistosoma japonicum and S. mansoni in mice. Interestingly, dihydroartemisinin is found to be highly effective against the 14-28-day schistosomula of S. mansoni, and treatment with multiple low doses of the drug achieves a high efficacy with reduced toxicity to the host. The long time development from juveniles to adults allows adequate timing for treatment of this neglected tropical disease. It is supposed that dihydroartemisinin, a safe orally administered agent, may be used for the prevention and control of human S. mansoni infections, notably in areas with reduced praziquantel sensitivity or praziquantel resistance detected.
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Artemisininas/uso terapéutico , Esquistosomiasis mansoni/tratamiento farmacológico , Esquistosomicidas/uso terapéutico , Animales , Femenino , Ratones , Praziquantel/uso terapéutico , Schistosoma mansoni/efectos de los fármacosRESUMEN
Artemisinin, also known as qinghaosu, is a sesquiterpene lactone endoperoxide extracted from the plant Artemisia annua L, an herb employed in traditional Chinese medicine. Artemisinin and its two main derivatives artemether and artesunate have been shown to be effective against both malaria and schistosomiasis, and therefore, they were described by Liu et al (Parasitol Res 110:2071-2074, 2012b) as the gifts from traditional Chinese medicine not only for malaria control but also for schistosomiasis control. However, another artemisinin derivative dihydroartemisinin (DHA) cannot be neglected. Dihydroartemisinin, a derivative of artemisinin with the C-10 lactone group replaced by hemiacetal and the active metabolite of all artemisinin compounds, was firstly identified as an antimalarial agent, and the dihydroartemisinin-piperaquine combination has been recommended as a first-line treatment of uncomplicated Plasmodium falciparum malaria by the WHO. It has been recently found that administration of dihydroartemisinin at a single dose of 300 mg/kg 2 h or 3, 5, 7, 10, 14, 18, 21, 28, or 35 days post-infection reduces total worm burdens by 1.1-64.8% and female worm burden reductions by 11.9-90.5%, and the in vivo activity of dihydroartemisinin against S. japonicum is enhanced by the use of multiple doses. However, a combination of praziquantel and dihydroartemisinin appears no more effective against S. japonicum schistosomulum than treatment with dihydroartemisinin alone. In mice experimentally infected with S. mansoni, administration with dihydroartemisinin at a single dose of 300 mg/kg on days 1, 7, 14, 21, 28, 35, 42, 49, or 56 post-infection results in total worm burden reductions of 13.8-82.1% and female worm burden reductions of 13-82.8%, and a clear-cut dose-response relationship of dihydroartemisinin against the schistosomula and adult worms of S. mansoni is observed. In addition, dihydroartemisinin was found to cause damages to the reproductive system of female S. mansoni worms, reduce the oviposition of survival worms, and inhibit the formation of granulomas around tissue-trapped eggs. More interestingly, no reduced sensitivity to dihydroartemisinin is detected in praziquantel non-susceptible S. japonicum, which provides a new option for the treatment of S. japonicum and S. mansoni infections, notably in endemic foci with praziquantel resistance or insensitivity detected. It is therefore considered that dihydroartemisinin is another gift from the traditional Chinese medicine not only for malaria control but also for schistosomiasis control.
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Artemisininas/farmacología , Medicamentos Herbarios Chinos/farmacología , Esquistosomicidas/farmacología , Animales , Antimaláricos/farmacología , Arteméter , Artesunato , Femenino , Malaria Falciparum/tratamiento farmacológico , Ratones , Praziquantel/farmacología , Esquistosomiasis Japónica/tratamiento farmacológicoRESUMEN
To facilitate the reuse of existing charts, previous research has examined how to obtain a semantic understanding of a chart by deconstructing its visual representation into reusable components, such as encodings. However, existing deconstruction approaches primarily focus on chart styles, handling only basic layouts. In this paper, we investigate how to deconstruct chart layouts, focusing on rectangle-based ones, as they cover not only 17 chart types but also advanced layouts (e.g., small multiples, nested layouts). We develop an interactive tool, called Mystique, adopting a mixed-initiative approach to extract the axes and legend, and deconstruct a chart's layout into four semantic components: mark groups, spatial relationships, data encodings, and graphical constraints. Mystique employs a wizard interface that guides chart authors through a series of steps to specify how the deconstructed components map to their own data. On 150 rectangle-based SVG charts, Mystique achieves above 85% accuracy for axis and legend extraction and 96% accuracy for layout deconstruction. In a chart reproduction study, participants could easily reuse existing charts on new datasets. We discuss the current limitations of Mystique and future research directions.
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This paper presents a systematic study of the generalization of convolutional neural networks (CNNs) and humans on relational reasoning tasks with bar charts. We first revisit previous experiments on graphical perception and update the benchmark performance of CNNs. We then test the generalization performance of CNNs on a classic relational reasoning task: estimating bar length ratios in a bar chart, by progressively perturbing the standard visualizations. We further conduct a user study to compare the performance of CNNs and humans. Our results show that CNNs outperform humans only when the training and test data have the same visual encodings. Otherwise, they may perform worse. We also find that CNNs are sensitive to perturbations in various visual encodings, regardless of their relevance to the target bars. Yet, humans are mainly influenced by bar lengths. Our study suggests that robust relational reasoning with visualizations is challenging for CNNs. Improving CNNs' generalization performance may require training them to better recognize task-related visual properties.
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Chaotic sequences are widely used in secure communication due to their high randomness. Chaotic resonance (CR) refers to the resonant response of a system to weak signals induced by chaotic activity, but its practical application remains limited. This study designs a simplified FitzHugh-Nagumo (FHN) auditory neuron model by simulating the physiological activities of auditory neurons and considering the combined stimulation of chaotic activity and sound signals. It is found that the neuron dynamics depend on both external sound stimuli and chaotic current intensity. Chaotic currents induce spikes in the neuron output sequence through CR, and the spikes become more frequent with increasing current intensity, eventually leading to a chaotic state regardless of the initial state. However, the sensitivity of the initial value of this chaotic sequence shifts to the chaotic current excitation system. The injection of chaotic currents can reduce the system's average Hamiltonian energy under certain conditions. By measuring the complexity of the generated sequences, we find that the addition of chaotic currents can enhance the complexity of the original sequences, and the enhancement ability increases with the intensity. This provides a new approach to enhance the complexity of original chaotic sequences. Moreover, different chaotic currents can induce different chaotic sequences with varying abilities to enhance the complexity of the original sequences. We hope our work can contribute to secure communication.
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Hearing impairment is considered to be related to the damage of hair cells or synaptic terminals, which will cause varying degrees of hearing loss. Numerous studies have shown that cochlear implants can balance this damage. The human ear receives external acoustic signals mostly under complex conditions, and its biophysical mechanisms have important significance for reference in the design of cochlear implants. However, the relevant biophysical mechanisms have not yet been fully determined. Using the characteristics of special acoustoelectric conversion in piezoelectric ceramics, this paper integrates them into the traditional FitzHugh-Nagumo neuron circuit and proposes a comprehensive model with coupled auditory neurons. The model comprehensively considers the effects of synaptic coupling between neurons, information transmission delay, external noise stimulation, and internal chaotic current stimulation on the synchronization of membrane potential signals of two auditory neurons. The experimental results show that coupling strength, delay size, noise intensity, and chaotic current intensity all have a certain regulatory effect on synchronization stability. In particular, when auditory neurons are in a chaotic state, their impact on synchronization stability is sensitive. Numerical results provide a reference for exploring the biophysical mechanisms of auditory neurons. At the same time, we are committed to providing assistance in using sensors to monitor signals and repair hearing impairments.
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We present an authoring tool, called CAST+ (Canis Studio Plus), that enables the interactive creation of chart animations through the direct manipulation of keyframes. It introduces the visual specification of chart animations consisting of keyframes that can be played sequentially or simultaneously, and animation parameters (e.g., duration, delay). Building on Canis [1], a declarative chart animation grammar that leverages data-enriched SVG charts, CAST+ supports auto-completion for constructing both keyframes and keyframe sequences. It also enables users to refine the animation specification (e.g., aligning keyframes across tracks to play them together, adjusting delay) with direct manipulation. We report a user study conducted to assess the visual specification and system usability with its initial version. We enhanced the system's expressiveness and usability: CAST+ now supports the animation of multiple types of visual marks in the same keyframe group with new auto-completion algorithms based on generalized selection. This enables the creation of more expressive animations, while reducing the number of interactions needed to create comparable animations. We present a gallery of examples and four usage scenarios to demonstrate the expressiveness of CAST+. Finally, we discuss the limitations, comparison, and potentials of CAST+ as well as directions for future research.
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Line-based density plots are used to reduce visual clutter in line charts with a multitude of individual lines. However, these traditional density plots are often perceived ambiguously, which obstructs the user's identification of underlying trends in complex datasets. Thus, we propose a novel image space coloring method for line-based density plots that enhances their interpretability. Our method employs color not only to visually communicate data density but also to highlight similar regions in the plot, allowing users to identify and distinguish trends easily. We achieve this by performing hierarchical clustering based on the lines passing through each region and mapping the identified clusters to the hue circle using circular MDS. Additionally, we propose a heuristic approach to assign each line to the most probable cluster, enabling users to analyze density and individual lines. We motivate our method by conducting a small-scale user study, demonstrating the effectiveness of our method using synthetic and real-world datasets, and providing an interactive online tool for generating colored line-based density plots.
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Solar-driven interfacial water purification emerges as a sustainable technology for seawater desalination and wastewater treatment to address the challenge of water scarcity. Currently, the energy losses via radiation and convection to surrounding environment minimize its energy efficiency. Therefore, it is necessary to develop strategies to minimize the heat losses for efficient water purification. Here, a novel evaporator was developed through the in situ gelation of PAM hydrogel on the surface carbonized hydroponic bamboo (PSC) to promote energy efficiency. The inherent porous and layered network structures of bamboo, in synergy with the functional hydration capacity of PAM hydrogel, facilitated adequate water transportation, while reducing evaporation enthalpy. The PAM hydrogel firmly covered on the photothermal layer surface effectively minimized the radiation and convection heat losses, while further harvesting those thermal energy that would otherwise dissipate into the surrounding environment. The reduced thermal conductivity of PSC served as a thermal insulator as well, obstructing heat transfer to bulk water and thus diminishing conduction losses. Consequently, the rational designed PSC could efficiently convert solar energy to purified water, leading to the evaporation of 2.09 kg m-2 h-1, the energy efficiency of 87.6 % under one sun irradiation, and yielding 9.6 kg m-2 fresh water over 11 h outdoor operation. Moreover, the PSC also performs excellent salt rejection, and long-term stability at outdoor experiment. These results demonstrated high and stable solar evaporation performance could be achieved if turning heat losses into a way of extra energy extraction to further enhance the evaporation performance. This strategy appears to be a promising strategy for effective thermal energy management and practical application.
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BACKGROUND AND OBJECTIVE: Medical image visualization is an essential tool for conveying anatomical information. Ray-casting-based volume rendering is commonly used for generating visualizations of raw medical images. However, exposing a target area inside the skin often requires manual tuning of transfer functions or segmentation of original images, as preset parameters in volume rendering may not work well for arbitrary scanned data. This process is tedious and unnatural. To address this issue, we propose a volume visualization system that enhances the view inside the skin, enabling flexible exploration of medical volumetric data using virtual reality. METHODS: In our proposed system, we design a virtual reality interface that allows users to walk inside the data. We introduce a view-dependent occlusion weakening method based on geodesic distance transform to support this interaction. By combining these methods, we develop a virtual reality system with intuitive interactions, facilitating online view enhancement for medical data exploration and annotation inside the volume. RESULTS: Our rendering results demonstrate that the proposed occlusion weakening method effectively weakens obstacles while preserving the target area. Furthermore, comparative analysis with other alternative solutions highlights the advantages of our method in virtual reality. We conducted user studies to evaluate our system, including area annotation and line drawing tasks. The results showed that our method with enhanced views achieved 47.73% and 35.29% higher accuracy compared to the group with traditional volume rendering. Additionally, subjective feedback from medical experts further supported the effectiveness of the designed interactions in virtual reality. CONCLUSIONS: We successfully address the occlusion problems in the exploration of medical volumetric data within a virtual reality environment. Our system allows for flexible integration of scanned medical volumes without requiring extensive manual preprocessing. The results of our user studies demonstrate the feasibility and effectiveness of walk-in interaction for medical data exploration.
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Realidad Virtual , Interfaz Usuario-Computador , PielRESUMEN
With the development of virtual reality, the practical requirements of the wearable haptic interface have been greatly emphasized. While passive haptic devices are commonly used in virtual reality, they lack generality and are difficult to precisely generate continuous force feedback to users. In this work, we present SmartSpring, a new solution for passive haptics, which is inexpensive, lightweight and capable of providing controllable force feedback in virtual reality. We propose a hybrid spring-linkage structure as the proxy and flexibly control the mechanism for adjustable system stiffness. By analyzing the structure and force model, we enable a smart transform of the structure for producing continuous force signals. We quantitatively examine the real-world performance of SmartSpring to verify our model. By asymmetrically moving or actively pressing the end-effector, we show that our design can further support rendering torque and stiffness. Finally, we demonstrate the SmartSpring in a series of scenarios with user studies and a just noticeable difference analysis. Experimental results show the potential of the developed haptic display in virtual reality.
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We present SizePairs, a new technique to create stable and balanced treemap layouts that visualize values changing over time in hierarchical data. To achieve an overall high-quality result across all time steps in terms of stability and aspect ratio, SizePairs employs a new hierarchical size-based pairing algorithm that recursively pairs two nodes that complement their size changes over time and have similar sizes. SizePairs maximizes the visual quality and stability by optimizing the splitting orientation of each internal node and flipping leaf nodes, if necessary. We also present a comprehensive comparison of SizePairs against the state-of-the-art treemaps developed for visualizing time-dependent data. SizePairs outperforms existing techniques in both visual quality and stability, while being faster than the local moves technique.