ABSTRACT
Although the combination of anti-vascular strategy plus immunotherapy has emerged as the optimal first-line treatment of hepatocellular carcinoma, lack of tumor targeting leads to low antitumor efficacy and serious side effect. Here, we report an ultra-pH-sensitive nanoparticle of gambogenic acid (GNA) encapsulated by poly(ethylene glycol)-poly(2-azepane ethyl methacrylate) (PEG-PAEMA) for tumor-targeting combined therapy of anti-vascular strategy plus immunotherapy. PEG-PAEMA-GNA nanoparticle was quite stable at pH 7.4 for 30 d. In contrast, it exerted size shrinkage, charge reversal and the release of GNA at pH 6.7 within 24 h. Moreover, PEG-PAEMA-GNA significantly enhanced the anti-vascular activity, membrane-disruptive capability and pro-apoptosis when pH changed from 7.4 to 6.7. Western blot analysis exhibits that PEG-PAEMA and its GNA nanoparticle facilitated the phosphorylation of STING protein. In vivo assays show that PEG-PAEMA-GNA not only displayed much higher tumor inhibition of 92 % than 37 % of free GNA, but also inhibited tumor vasculature, promoted the maturation of dendritic cells and recruited more cytotoxic t-lymphocytes for sufficient anti-vascular therapy and immunotherapy. All these results demonstrate that PEG-PAEMA-GNA displayed tumor-targeting combined treatment of anti-vascular therapy and immunotherapy. This study offers a simple and novel method for the combination of anti-vascular therapy and immunotherapy with high selectivity towards tumor.
Subject(s)
Immunotherapy , Nanoparticles , Polyethylene Glycols , Xanthenes , Animals , Immunotherapy/methods , Nanoparticles/chemistry , Hydrogen-Ion Concentration , Polyethylene Glycols/chemistry , Polyethylene Glycols/administration & dosage , Xanthenes/chemistry , Xanthenes/administration & dosage , Xanthenes/pharmacology , Cell Line, Tumor , Humans , Mice , Apoptosis/drug effects , Carcinoma, Hepatocellular/therapy , Carcinoma, Hepatocellular/drug therapy , Liver Neoplasms/therapy , Liver Neoplasms/drug therapy , Mice, Inbred C57BL , Dendritic Cells/drug effects , Dendritic Cells/immunology , Mice, Inbred BALB C , Xanthones/chemistry , Xanthones/administration & dosage , Xanthones/pharmacology , Drug Liberation , Human Umbilical Vein Endothelial Cells , T-Lymphocytes, Cytotoxic/immunology , T-Lymphocytes, Cytotoxic/drug effectsABSTRACT
Electrochemical nitrate reduction reaction (NitRR) uses nitrate from wastewater, offering a hopeful solution for environmental issues and ammonia production. Yet, varying nitrate levels in real wastewater greatly affect NitRR, slowing down its multi-step process. Herein, a multi-strategy approach was explored through the design of ordered mesoporous intermetallic AuCu3 nanocorals with ultrathin Au skin (meso-i-AuCu3@ultra-Au) as an efficient and concentration-versatile catalyst for NitRR. The highly penetrated structure, coupled with the compressive stress exerted on the skin layer, not only facilitates rapid electron/mass transfer, but also effectively modulates the surface electronic structure, addressing the concentration-dependent challenges encountered in practical NitRR process. As expected, the novel catalyst demonstrates outstanding NitRR activities and Faradaic efficiencies exceeding 95 % across a real and widespread concentration range (10-2000â mM). Notably, its performance at each concentration matched or exceeded that of the best-known catalyst designed for that concentration. Multiple operando spectroscopies unveiled the catalyst concurrently optimized the adsorption behavior of different intermediates (adsorbed *NOx and *H) while expediting the hydrogenation steps, leading to an efficient overall reduction process. Moreover, the catalyst also displays promising potential for use in ammonia production at industrial-relevant current densities and in conceptual zinc-nitrate batteries, serving trifunctional nitrate conversion, ammonia synthesis and power supply.
ABSTRACT
Substantial evidence suggests that all types of water, such as drinking water, wastewater, surface water, and groundwater, can be potential sources of Helicobacter pylori (H. pylori) infection. Thus, it is critical to thoroughly investigate all possible preconditioning methods to enhance the recovery of H. pylori, improve the reproducibility of subsequent detection, and optimize the suitability for various water types and different detection purposes. In this study, we proposed and evaluated five distinct preconditioning methods for treating water samples collected from multiple urban water environments, aiming to maximize the quantitative qPCR readouts and achieve effective selective cultivation. According to the experimental results, when using the qPCR technique to examine WWTP influent, effluent, septic tank, and wetland water samples, the significance of having a preliminary cleaning step becomes more evident as it can profoundly influence qPCR detection results. In contrast, the simple, straightforward membrane filtration method could perform best when isolating and culturing H. pylori from all water samples. Upon examining the cultivation and qPCR results obtained from groundwater samples, the presence of infectious H. pylori (potentially other pathogens) in aquifers must represent a pressing environmental emergency demanding immediate attention. Furthermore, we believe groundwater can be used as a medium to reflect the H. pylori prevalence in a highly populated community due to its straightforward analytical matrix, consistent detection performance, and minimal interferences from human activities, temperature, precipitation, and other environmental fluctuations.
Subject(s)
Groundwater , Helicobacter pylori , Water Microbiology , Helicobacter pylori/isolation & purification , Groundwater/microbiology , Real-Time Polymerase Chain Reaction , Wastewater/microbiology , CitiesABSTRACT
RuO2 has been considered as the most likely acidic oxygen evolution reaction (OER) catalyst to replace IrO2, but its performance, especially long-term stability under harsh acidic conditions, is still unacceptable. Here, we propose a grain boundary (GB) engineering strategy by fabricating the ultrathin porous RuO2 nanosheet with abundant of grain boundaries (GB-RuO2) as an efficient acid OER catalyst. The involvement of GB induces significant tensile stress and creates an unsaturated coordination environment, effectively optimizing the adsorption of intermediates and stabilizing active site structure during OER process. Notably, the GB-RuO2 not only exhibits a low overpotential (η10=187â mV) with an ultra-low Tafel slope (34.5â mV dec-1), but also steadily operates for over 550â h in 0.1â M HClO4. Quasi in situ/operando methods confirm that the improved stability is attributed to GB preventing Ru dissolution and greatly inhibiting the lattice oxygen oxidation mechanism (LOM). A proton exchange membrane water electrolysis (PEMWE) using the GB-RuO2 catalyst operates a low voltage of 1.669â V at 2â A cm-2 and operates stably for 100â h at 100â mA cm-2.
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Background: There is no doubt that both Hashimoto thyroiditis and Graves' disease are autoimmune thyroid diseases (AITDs), but the relationship between anti-nuclear antibody (ANA) and AITDs is poorly studied. The association between thyroid autoantibody levels and ANA positivity was evaluated to assess the role of ANA in AITDs. Methods: We conducted an analysis using data from 1,149,893 patients registered at our hospital and 53,021 patients registered in the National Health and Nutrition Examination Survey databases. We focused on patients with data for thyroid peroxidase antibody (TPOAb)/ANA, TPOAb/immunoglobulin G (IgG), thyroid-stimulating hormone (TSH) receptor antibody (TRAb)/ANA, TRAb/IgG, TSH/ANA, or TSH/IgG. Results: ANA positivity rates were 12.88% and 21.22% in TPOAb/ANA and TSH/ANA patients, respectively. In TPOAb/IgG and TSH/IgG data, high IgG levels (≥15 g/L) were detected in 2.23% and 4.06% of patients, respectively. There were significant differences in ANA positivity rates and high IgG proportions among patients with different TPOAb and TSH levels. TPOAb level was correlated with ANA positivity rate and high IgG proportion, and TSH level was correlated with ANA positivity rate. Regression analysis showed positive correlations between TPOAb levels and ANA positivity risk or high IgG risk, TSH levels and high IgG risk, and elevated TSH and ANA positivity risk. Of patients with TRAb/ANA data, 35.99% were ANA-positive, and 13.93% had TRAb levels ≥1.75IU/L; 18.96% of patients with TRAb/IgG data had high IgG levels, and 16.51% had TRAb levels ≥1.75IU/L. ANA positivity rate and high IgG proportion were not significantly different among different TRAb levels. TRAb levels, ANA positivity risk and high IgG risk were not correlated. Conclusion: ANA positivity and high IgG are related to Hashimoto thyroiditis but not Graves' disease, which implies distinct pathophysiological mechanisms underlying the AITDs.
Subject(s)
Graves Disease , Hashimoto Disease , Humans , Nutrition Surveys , Autoantibodies , Graves Disease/diagnosis , Receptors, Thyrotropin , Immunoglobulin G , ThyrotropinABSTRACT
BACKGROUND AND PURPOSE: Obesity among children and adolescents continues to increase globally, and it is important to determine the factors associated with obesity among adolescents for the prevention and reduction of obesity. The purpose of this study is to understand the factors associated with the increase in the obesity rate among adolescents, providing a reference basis for the development of projects aimed at promoting adolescent health. METHODS: Using the raw data of 2021 adolescent health behavior online survey, this study analyzed demographic sociological factors, mental health, exercise habits, health behaviors and other categorical variables, and conducted the frequency, χ2 test for the difference in the proportion of obese and non-obese. According to the hierarchy model of obesity-related variables, binary logistics regression is used for multivariate analysis. This study used the original data of the 2021 Youth Health Behavior Online Survey, and performed frequency, χ2 tests on the differences in the proportion of obese and non-obese for categorical variables such as demographic sociological factors, mental health, exercise habits, and health behaviors. Multivariate analysis was performed using binary logistic regression based on hierarchical models of obesity-related variables. RESULTS: The obesity rate among Korean adolescents was 18.25 %. The obesity risk for females was reduced by 0.344 times compared to males (95 % CI = 0.327-0.361, p < 0.001); high school students had a 1.4 times higher obesity risk than middle school students (95 % CI = 1.379-1.511, p < 0.001); students with "Subjective household economic status" rated as "Medium" and 'Low' had their obesity risk increased by 1.07 times (95 % CI = 1.020-1.124, p < 0.01) and 1.254 times (95 % CI = 1.165-1.350, p < 0.001), respectively, compared to students with 'Subjective household economic status' rated as 'High'; students with 'Moderate' and 'Low' levels of 'Perceived stress' had their obesity risk reduced by 0.78 times (95 % CI = 0.74-0.823, P < 0.001) and 0.75 times (95 % CI = 0.70-0.803, P < 0.001), respectively, compared to students with 'High' levels of 'Perceived stress'; students engaging in 'Muscle strengthening exercise' '1-2 times/week' and "≥ 3 times/week" had their obesity risk reduced by 0.844 times (95% CI = 0.797-0.895, P < 0.001) and 0.575 times (95% CI = 0.537-0.616, P < 0.001), respectively, compared to students not participating in "Muscle strengthening exercise". CONCLUSION: The obesity rate of boys is higher than that of girls and high school students is higher than that of middle school students, and obesity is inversely proportional to family economic status. Mental health factors, exercise habits and eating habits are all important factors affecting adolescent obesity. It is suggested that gender differences, psychological factors, health habits, obesity education and healthy eating habits suitable for different age groups should be considered in the formulation of adolescent obesity policy.
Subject(s)
Pediatric Obesity , Male , Female , Child , Adolescent , Humans , Pediatric Obesity/epidemiology , Health Behavior , Exercise/physiology , Educational Status , HabitsABSTRACT
Noble metal free electrocatalysts for hydrogen evolution reaction (HER) in acid play an important role in proton exchange membrane-based electrolysis. Here, we develop an in situ surface self-reconstruction strategy to construct excellent acidic HER catalysts. Firstly, free-standing zinc nickel tungstate nanosheets inlaid with nickel tungsten alloy nanoparticles were synthesized on carbon cloth as pre-catalyst via metal-organic framework derived method. Amorphous nickel tungsten oxide (Ni-W-O) layer is in situ formed on surface of nanosheet as actual HER active site with the dissolution of NiW alloy nanoparticles and the leaching of cations. While the morphology of the free-standing structure remains the same, keeping the maximized exposure of active sites and serving as the electron transportation framework. As a result, benefiting from disordered arrangement of atoms and the synergistic effect between Ni and W atoms, the amorphous Ni-W-O layer exhibits an excellent acidic HER activity with only an overpotential of 46 mV to drive a current density of 10 mA cm-2 and a quite good Tafel slope of 36.4 mV dec-1 as well as an excellent durability. This work enlightens the exploration of surface evolution of catalysts during HER in acidic solution and employs it as a strategy for designing acidic HER catalysts.
ABSTRACT
Zn-N-C possesses the intrinsic inertia for Fenton-like reaction and can retain robust durability in harsh circumstance, but it is often neglected in oxygen reduction reaction (ORR) because of its poor catalytic activity. Zn is of fully filled 3d10 4s2 configuration and is prone to evaporation, making it difficult to regulate the electronic and geometric structure of Zn center. Here, guided by theoretical calculations, five-fold coordinated single-atom Zn sites with four in-plane N ligands is constructed and one axial O ligand (Zn-N4 -O) by ionic liquid-assisted molten salt template method. Additional axial O not only triggers a geometry transformation from the planar structure of Zn-N4 to the non-planar structure of Zn-N4 -O, but also induces the electron transfer from Zn center to neighboring atoms and lower the d-band center of Zn atom, which weakens the adsorption strength of *OH and decreases the energy barrier of rate determining step of ORR. Consequently, the Zn-N4 -O sites exhibit improved ORR activity and excellent methanol tolerance with long-term durability. The Zn-air battery assembled by Zn-N4 -O presents a maximum power density of 182 mW cm-2 and can operate continuously for over 160 h. This work provides new insights into the design of Zn-based single atom catalysts through axial coordination engineering.
ABSTRACT
Utilizing catalysts to accelerate polysulfides conversion are of paramount importance to eliminate the shuttling effect and improve the practical performance of lithium-sulfur (Li-S) batteries. The amorphism, attributes to the abundant unsaturated surface active sites, has recently been recognized as a contribution to increase the activity of catalysts. However, the investigation on amorphous catalysts has received limited interest in lithium-sulfur batteries due to lack of understanding of their composition structure activity. Herein, a amorphous Fe-Phytate structure is proposed to enhance polysulfide conversion and suppress polysulfide shuttling by modifying polypropylene separator (C-Fe-Phytate@PP). The polar Fe-Phytate with distorted VI coordination Fe active centers strongly intake polysulfide electron by forming FeS bond to accelerate the polysulfide conversion. The surface mediated polysulfides redox gives rise to a higher exchange current in comparison with carbon. Furthermore, Fe-Phytate owns robust adsorption to polysulfide and effectively reduce the shuttling effect. With the C-Fe-Phytate@PP separator, the Li-S batteries exhibit an outstanding rate capability of 690 mAh g-1 at 5 C and an ultrahigh areal capacity of 7.8 mAh cm-2 even at a high sulfur loading of 7.3 mg cm-2 . The work provides a novel separator for facilitating the actual applications of Li-S batteries.
ABSTRACT
Because of the increasing scarcity of water resources, the desalination of seawater by photothermal evaporation with harvested solar energy has gradually become a popular research topic. The interconnected macroporous cryogel prepared from polymerization and crosslinking below the freezing temperature of the reactant solution has an excellent performance in photothermal water evaporation after loading photothermal materials. In this study, polyacrylamide (PAM) cryogels were prepared by cryo-polymerization and sulfonated in an alkaline solution containing formaldehyde and Na2SO3. Importantly, the evaporation enthalpy of water in sulfonated PAM cryogel was reduced to 1187 J·g-1 due to the introduction of sulfonate groups into PAM, which was beneficial to increase the photothermal evaporation rate and efficiency. The sulfonated PAM cryogels loaded with polypyrrole and the umbrella-shaped melamine foam substrate were combined to form a photothermal evaporation device, and the evaporation rate was as high as 2.50 kg·m-2·h-1 under one-sun radiation. Meanwhile, the evaporation rate reached 2.09 kg·m-2·h-1 in the 14 wt% high-concentration saline solution, and no salt crystals appeared on the surface of the cryogel after 5 h of photothermal evaporation. Therefore, it was evidenced that the presence of sulfonate groups not only reduced the evaporation enthalpy of water but also prevented salting-out from blocking the water delivery channel during photothermal evaporation, with a sufficiently high evaporation rate, providing a reliable idea of matrix modification for the design of high-efficiency photothermal evaporation materials.
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Fluidic soft robots have the advantages of inherent compliance and adaptability, but they are significantly restricted by complex control systems and bulky power devices, including fluidic valves, fluidic pumps, electrical motors, as well as batteries, which make it challenging to operate in narrow space, energy shortage, or electromagnetic sensitive situations. To overcome the shortcomings, we develop portable human-powered master controllers to provide an alternative solution for the master-slave control of the fluidic soft robots. Each controller can supply multiple fluidic pressures to the multiple chambers of the soft robots simultaneously. We use modular fluidic soft actuators to reconfigure soft robots with various functions as control objects. Experimental results show that flexible manipulation and bionic locomotion can be simply realized using the human-powered master controllers. The developed controllers which eliminate energy storage and electronic components can provide a promising candidate of soft robot control in surgical, industrial, and entertainment applications.
ABSTRACT
Without excess Li, anode-free Li-metal batteries (AFLMBs) have been proposed as the most likely solution to realizing highly-safe and cost-effective Li-metal batteries. Nevertheless, short cyclic life puzzles conventional AFLMBs due to anodic dead Li accumulation with a local current concentration induced by irreversible electrolyte depletion, insufficient active Li reservoir and slow Li+ transfer at the solid electrolyte interphase (SEI). Herein, SrI2 is introduced into carbon paper (CP) current collector to effectively suppress dead Li through synergistic mechanisms including reversible I- /I3 - redox reaction to reactivate dead Li, dielectric SEI surface with SrF2 and LiF to prevent electrolyte decomposition and highly ionic conductive (3.488â mS cm-1 ) inner layer of SEI with abundant LiI to enable efficient Li+ transfer inside. With the SrI2 -modified current collector, the NCM532/CP cell delivers unprecedented cyclic performances with a capacity of 129.2â mAh g-1 after 200â cycles.
ABSTRACT
The membrane-disruptive strategy, which involves host defense peptides and their mimetics, is a revolutionary cancer treatment based on broad-spectrum anticancer activities. However, clinical application is limited by low selectivity towards tumors. In this context, we have established a highly selective anticancer polymer, i.e. poly(ethylene glycol)-poly(2-azepane ethyl methacrylate) (PEG-PAEMA), that can mediate the membrane-disruptive activity via a subtle pH change between physiological pH and tumor acidity for selective cancer treatment. Specifically, the resulting PEG-PAEMA can assemble into neutral nanoparticles and silence the membrane-disruptive activity at physiological pH and disassemble into cationic free-chains or smaller nanoparticles with potent membrane-disruptive activity after the protonation of the PAEMA block due to tumor acidity, resulting in high selectivity towards tumors. Dramatically, PEG-PAEMA exhibited a >200-fold amplification in hemolysis and <5% in IC50 against Hepa1-6, SKOV3 and CT-26 cells at pH 6.7 as compared to those at pH 7.4, thanks to the selective membrane-disruptive mechanism. Moreover, mid- and high-dose PEG-PAEMA demonstrated higher anticancer efficacy than an optimal clinical prescription (bevacizumab plus PD-1) and, significantly, had few side effects on major organs in the tumor-bearing mice model, agreeing with the highly selective membrane-disruptive activity in vivo. Collectively, this work showcases the latent anticancer pharmacological activity of the PAEMA block, and also brings new hope for selective cancer therapy.
Subject(s)
Neoplasms , Polyethylene Glycols , Animals , Mice , Hydrogen-Ion Concentration , Polyethylene Glycols/therapeutic use , Neoplasms/drug therapy , Hydrophobic and Hydrophilic InteractionsABSTRACT
For the maintenance of a biological system, spatial organization of material condensates within the cell through the dissipation of energy is crucial. Besides directed transport via microtubules, material arrangement can be achieved via motor protein facilitated adaptive active diffusiophoresis. For example, the distribution of membrane proteins during the cell division of Escherichia coli is affected by the MinD system. Synthetic active motors exhibit the ability to simulate natural motors. Here we propose an active Au-Zn nanomotor driven by water and discovered an interesting adaptive interaction mode of the diffusiophoretic Au-Zn nanomotors with passive condensate particles in different environments. It is found that the attraction/repulsion between the nanomotor and passive particles is adaptive, while an interesting hollow pattern is formed with a negatively charged substrate and a cluster pattern is favored with a positively charged substrate.
ABSTRACT
How to achieve efficient drug accumulation in the tumor with low vascular density is a great challenge but the key to push the limit of anti-vascular therapeutic efficacy. Herein, we report a charge-reversible nanoparticles of gambogenic acid (CRNP-GNA) that would induce the positive feedback loop between increased tumor vascular permeability and improved drug accumulation. This positive feedback loop would remarkably improve tumor vascular permeability for efficient drug accumulation through few residue vessels. As compared to its charge-irreversible analogue in the latter injections, the accumulation in tumor and vascular permeability and retention indexes (VPRI) in CRNP-GNA group respectively boosted from nearly equal to 8.32 and 60 times, while its tumorous microvessel density decreased from nearly equal to only 7%. The self-augmented accumulation consequently amplified the antitumor efficacy via multiple pathways of anti-angiogenesis, vascular disruption and pro-apoptosis, where 5 out of 6 tumors in animal models were completely cured by CRNP-GNA. This work confirms that the underlying positive feedback loop for anti-vascular therapy could be induced by charge-reversible drug delivery nanosystem to achieve efficient and self-augmented drug accumulation even in the tumor with few vessels. It provides a novel strategy to conquer the dilemma between anti-vascular efficacy and drug accumulation.
Subject(s)
Nanoparticles , Neoplasms , Animals , Feedback , Neoplasms/drug therapy , Drug Delivery Systems , Nanoparticles/chemistry , Cell Line, TumorABSTRACT
The soluble fraction of atmospheric transition metals is particularly associated with health effects such as reactive oxygen species compared to total metals. However, direct measurements of the soluble fraction are restricted to sampling and detection units in sequence burdened with a compromise between time resolution and system bulkiness. Here, we propose the concept of aerosol-into-liquid capture and detection, which allowed one-step particle capture and detection via the Janus-membrane electrode at the gas-liquid interface, enabling active enrichment and enhanced mass transport of metal ions. The integrated aerodynamic/electrochemical system was capable of capturing airborne particles with a cutoff size down to 50 nm and detecting Pb(II) with a limit of detection of 95.7 ng. The proposed concept can pave the way for cost-effective and miniaturized systems, for the capture and detection of airborne soluble metals in air quality monitoring, especially for abrupt air pollution events with high airborne metal concentrations (e.g., wildfires and fireworks).
ABSTRACT
Entity summarization is a novel and efficient way to understand real-world facts and solve the increasing information overload problem in large-scale knowledge graphs (KG). Existing studies mainly rely on ranking independent entity descriptions as a list under a certain scoring standard such as importance. However, they often ignore the relatedness and even semantic overlap between individual descriptions. This may seriously interfere with the contribution judgment of descriptions for entity summarization. Actually, the entity summary is a whole to comprehensively integrate the main aspects of entity descriptions, which could be naturally treated as a set. Unfortunately, the exploration of these set characteristics for entity summarization is still an open issue with great challenges. To that end, we draw inspiration from a set completion perspective and propose an entity summarization method with complementarity and salience (ESCS) to deeply exploit description complementarity and salience in order to form a summary set for the target entity. Specifically, we first generate entity description representations with textual features in the description embedding module. For the purpose of learning complementary relationships within the entire summary set, we devise a bi-directional long short-term memory structure to capture global complementarity for each summary in the summary complementarity learning module. Meanwhile, in order to estimate the salience of individual descriptions, we calculate similarities between semantic embeddings of the target entity and its property-value pairs in the description salience learning module. Next, with a joint learning stage, we can optimize ESCS from a set completion perspective. Finally, a summary generation strategy is designed to infer the entire summary set step-by-step for the target entity. Extensive experiments on a public benchmark have clearly demonstrated the effectiveness of ESCS and revealed the potential of set completion in entity summarization task.
Subject(s)
Benchmarking , Neural Networks, Computer , Knowledge , Learning , Memory, Long-TermABSTRACT
SARS-CoV-2 spreads via droplets, aerosols, and smear infection. From the beginning of the COVID-19 pandemic, using a facemask in different locations was recommended to slow down the spread of the virus. To evaluate facemasks' performance, masks' filtration efficiency is tested for a range of particle sizes. Although such tests quantify the blockage of the mask for a range of particle sizes, the test does not quantify the cumulative amount of virus-laden particles inhaled or exhaled by its wearer. In this study, we quantify the accumulated viruses that the healthy person inhales as a function of time, activity level, type of mask, and room condition using a physics-based model. We considered different types of masks, such as surgical masks and filtering facepieces (FFPs), and different characteristics of public places such as office rooms, buses, trains, and airplanes. To do such quantification, we implemented a physics-based model of the mask. Our results confirm the importance of both people wearing a mask compared to when only one wears the mask. The protection time for light activity in an office room decreases from 7.8 to 1.4 h with surgical mask IIR. The protection time is further reduced by 85 and 99% if the infected person starts to cough or increases the activity level, respectively. Results show the leakage of the mask can considerably affect the performance of the mask. For the surgical mask, the apparent filtration efficiency reduces by 75% with such a leakage, which cannot provide sufficient protection despite the high filtration efficiency of the mask. The facemask model presented provides key input in order to evaluate the protection of masks for different conditions in public places. The physics-based model of the facemask is provided as an online application.
Subject(s)
COVID-19 , SARS-CoV-2 , Humans , Pandemics/prevention & control , COVID-19/prevention & control , Respiratory Aerosols and Droplets , Masks , PhysicsABSTRACT
The macro-porous structure of polymer cryogels provides an appropriate channel for the adsorption and transport of substances, endowing its application in the field of electrochemical sensing. The combination mode of a polymer matrix and electro-active substance, particularly the distribution of an electro-active substance in the matrix, has an important effect on the overall performance of the sensor. In this work, through the simultaneous oxidation coupling polymerization of aniline (ANI) and radical polymerization of acrylamide (AAm) under cryogenic condition, conductive composite cryogels were prepared, aiming for the uniform distribution of PANI in the PAAm matrix. The possibility of simultaneous polymerizations was symmetrically investigated, and the obtained PANI/PAAm cryogels were characterized. Due to the acid-doping of PANI, the electrical conductivity of PANI/PAAm cryogels could be modulated with acidic and basic gases. Thus, the performance of the gas sensor was studied by making conductive PANI/PAAm cryogel sheets as resistive sensor electrodes. We found that the content of PANI, the sheet thickness and the dry/wet state of the cryogel influenced the response sensitivity and rate as well as the recovery properties. The response duration for HCl and NH3 gas was shorter than 70 and 120 s, respectively. The cyclic detection of HCl gas and the alternate detection of NH3/HCl were achieved. This gas sensor with advantages, including simple preparation, low cost and high sensitivity, would have great potential for the application to monitor the leakage of acidic and basic gases.
ABSTRACT
High-voltage lithium metal batteries (HVLMBs) have been arguably regarded as the most prospective solution to ultrahigh-density energy storage devices beyond the reach of current technologies. Electrolyte, the only component inside the HVLMBs in contact with both aggressive cathode and Li anode, is expected to maintain stable electrode/electrolyte interfaces (EEIs) and facilitate reversible Li+ transference. Unfortunately, traditional electrolytes with narrow electrochemical windows fail to compromise the catalysis of high-voltage cathodes and infamous reactivity of the Li metal anode, which serves as a major contributor to detrimental electrochemical performance fading and thus impedes their practical applications. Developing stable electrolytes is vital for the further development of HVLMBs. However, optimization principles, design strategies, and future perspectives for the electrolytes of the HVLMBs have not been summarized in detail. This review first gives a systematical overview of recent progress in the improvement of traditional electrolytes and the design of novel electrolytes for the HVLMBs. Different strategies of conventional electrolyte modification, including high concentration electrolytes and CEI and SEI formation with additives, are covered. Novel electrolytes including fluorinated, ionic-liquid, sulfone, nitrile, and solid-state electrolytes are also outlined. In addition, theoretical studies and advanced characterization methods based on the electrolytes of the HVLMBs are probed to study the internal mechanism for ultrahigh stability at an extreme potential. It also foresees future research directions and perspectives for further development of electrolytes in the HVLMBs.