High Breakthrough Pressure in Hydrogels Enabled Ultrastable Treatment of Hypersaline Wastewaters.

Surface effects of low-surface-tension contaminants accumulating at the evaporation surface easily induce wetting in membrane distillation, especially in hypersaline scenarios. Herein, we propose a novel strategy to eliminate the surface effect and redistribute contaminants at the evaporation interface simply by incorporating a layer of hydrogel. The as-fabricated composite membrane exhibits remarkable stability, even when exposed to solution with salt concentration of 5 M and surfactant concentration of 8 mM. Breakthrough pressure of the membrane reaches 20 bar in the presence of surfactants, surpassing commercial hydrophobic membranes by one to two magnitudes. Density functional theory and molecular dynamics simulations reveal the important role of the hydrogel-surfactant interaction in suppressing the surface effect. As a proof of concept, we demonstrate the membrane in stably processing synthetic wastewater containing 144 mg L-1 surfactants, 1 g L-1 mineral oils, and 192 g L-1 NaCl, showing its potential in addressing challenges of hypersaline water treatment.

Cation-Conduction Dominated Hydrogels for Durable Zinc-Iodine Batteries.

Zinc-iodine batteries have the potential to offer high energy-density aqueous energy storage, but their lifetime is limited by the rampant dendrite growth and the concurrent parasite side reactions on the Zn anode, as well as the shuttling of polyiodides. Herein, a cation-conduction dominated hydrogel electrolyte is designed to holistically enhance the stability of both zinc anode and iodine cathode. In this hydrogel electrolyte, anions are covalently anchored on hydrogel chains, and the major mobile ions in the electrolyte are restricted to be Zn2+ . Specifically, such a cation-conductive electrolyte results in a high zinc ion transference number (0.81) within the hydrogel and guides epitaxial Zn nucleation. Furthermore, the optimized Zn2+ solvation structure and the reconstructed hydrogen bond networks on hydrogel chains contribute to the reduced desolvation barrier and suppressed corrosion side reactions. On the iodine cathode side, the electrostatic repulsion between negative sulfonate groups and polyiodides hinders the loss of the iodine active material. This all-round electrolyte design renders zinc-iodine batteries with high reversibility, low self-discharge, and long lifespan.

Hetero-Polyionic Hydrogels Enable Dendrites-Free Aqueous Zn-I2 Batteries with Fast Kinetics.

Rechargeable aqueous Zn-I2 batteries (ZIB) are regarded as a promising energy storage candidate. However, soluble polyiodide shuttling and rampant Zn dendrite growth hamper its commercial implementation. Herein, a hetero-polyionic hydrogel is designed as the electrolyte for ZIBs. On the cathode side, iodophilic polycationic hydrogel (PCH) effectively alleviates the shuttle effect and facilitates the redox kinetics of iodine species. Meanwhile, polyanionic hydrogel (PAH) toward Zn metal anode uniformizes Zn2+ flux and prevents surface corrosion by electrostatic repulsion of polyiodides. Consequently, the Zn symmetric cells with PAH electrolyte demonstrate remarkable cycling stability over 3000 h at 1 mA cm-2 (1 mAh cm-2 ) and 800 h at 10 mA cm-2 (5 mAh cm-2 ). Moreover, the Zn-I2 full cells with PAH-PCH hetero-polyionic hydrogel electrolyte deliver a low-capacity decay of 0.008 ‰ per cycle during 18 000 cycles at 8 C. This work sheds light on hydrogel electrolytes design for long-life conversion-type aqueous batteries.

Negative Pressure in Water for Efficient Heat Utilization and Transfer.

Thermodynamic metastable water in negative pressure provides a possible solution to elevate the upper limit of evaporative heat transfer capacity and the efficiency of low-grade heat utilization, but practical implementations are challenging due to the difficulty in generating and maintaining large negative pressure. Herein, we report a novel structure with a hydrogel film as the evaporation surface and a permeable substrate as the functional layer to suppress cavitation. Based on the structure, we achieve an evaporation-driven flow system with negative pressure as low as -1.67 MPa. Molecular dynamics simulations elucidate the importance of strong water-polymer interactions in negative pressure generation. With the large negative pressure, we demonstrate a streaming potential generator that spontaneously converts environmental energy into electricity and outputs a voltage of 1.06 V. Moreover, we propose a "negative pressure heat pipe", which achieves a high heat transfer density of 9.6 kW cm-2 with a flow length of 1 m.

Non-invasive monitoring of biochemicals in hydrogel-assisted microfluidic chips.

Microfluidic chips are prevailingly utilized in biochemical monitoring and clinical diagnostics due to their capability of manipulating minuscule amounts of liquids in a highly integrated manner. Fabrication of microchannels on chips is commonly based on glass or polydimethylsiloxane, and sensing of the fluids and biochemicals within them relies on invasive embedded sensing accessories in the channels. In this study, we propose a hydrogel-assisted microfluidic chip for non-invasive monitoring of chemicals in microfluidics. A nanoporous hydrogel acts as a perfect sealing film on top of a microchannel to encapsulate liquid, and allows for the delivery of target biochemicals to its surface, leaving an open window for non-invasive analysis. This functionally "open" microchannel can be integrated with various electrical, electrochemical, and optical methods to realize accurate detection of biochemicals, suggesting the potential of hydrogel microfluidic chips for non-invasive clinical diagnostics and smart healthcare.

Research on Non-Pooling YOLOv5 Based Algorithm for the Recognition of Randomly Distributed Multiple Types of Parts.

Part cleaning is very important for the assembly of precision machinery. After cleaning, the parts are randomly distributed in the collection area, which makes it difficult for a robot to collect them. Common robots can only collect parts located in relatively fixed positions, and it is difficult to adapt these robots to collect at randomly distributed positions. Therefore, a rapid part classification method based on a non-pooling YOLOv5 network for the recognition of randomly distributed multiple types of parts is proposed in this paper; this method classifies parts from their two-dimensional images obtained using industrial cameras. We compared the traditional and non-pooling YOLOv5 networks under different activation functions. Experimental results showed that the non-pooling YOLOv5 network improved part recognition precision by 8% and part recall rate by 3% within 100 epochs of training, which helped improve the part classification efficiency. The experiment showed that the non-pooling YOLOv5 network exhibited improved classification of industrial parts compared to the traditional YOLOv5 network.

Eight weeks of dry dynamic breath-hold training results in larger spleen volume but does not increase haemoglobin concentration.

Purpose: It has previously been reported that repeated exposure to hypoxia increases spleen size and haemoglobin (HGB) level and recent reports on the effect apnoea has on spleen size and haematological parameters are contradictory. Therefore, this study aims to evaluate the effect apnoea training has on spleen size and haematological parameters. Methods: The breath-holding (BH) group was comprised of 12 local student-athletes with no BH exercise experience who performed BH jogging and BH jumping rope dynamic apnoea protocols, five times weekly for 8 weeks. The BH event duration was progressively increased as the apnoea tolerance of the athletes improved (20 to 35 s). The same training task was performed by the control group (n = 10) without BH. Spleen sizes were measured with an ultrasound system and a complete blood cell analysis was performed on the median cubital venous blood. Results: Spleen volume in the BH group increased from 109 ± 13 ml to 136 ± 13 ml (p < 0.001), and bulky platelets decreased from 70.50 ± 5.83 to 65.17 ± 5.87 (p = 0.034), but no changes were recorded for erythrocytes (p = 0.914), HGB (p = 0.637), PLTs (p = 0.346) and WBC (p = 0.532). No changes were recorded for the control group regarding spleen size or haematological parameters. Conclusion: Eight weeks of dry dynamic apnoea training increased spleen size and decreased the number of circulating bulky platelets in the athletes who were assessed in this study. However, the baseline RBC counts and HGB levels of the athletes were not altered by the training programme.

Stretchable and Self-Powered Temperature-Pressure Dual Sensing Ionic Skins Based on Thermogalvanic Hydrogels.

Tactile sensors with both temperature- and pressure-responsive capabilities are critical to enabling future smart artificial intelligence. These sensors can mimic haptic functions of human skin and inevitably suffer from tensile deformation during operation. However, almost all actual multifunctional tactile sensors are either nonstretchable or the sensing signals interfere with each other when stretched. Herein, we propose a stretchable and self-powered temperature-pressure dual functional sensor based on thermogalvanic hydrogels. The sensor operates properly under stretching, which relies on the thermogalvanic effect and constant elastic modulus of hydrogels. The thermogalvanic hydrogel elastomer exhibits an equivalent Seebeck coefficient of -1.21 mV K-1 and a pressure sensitivity of 0.056 kPa-1. Combined with unit array integration, the multifunctional sensor can be used for accurately recording tactile information on human skin and spatial perception. This work provides a conceptual framework and systematic design for stretchable artificial skin, interactive wearables, and smart robots.

AAV-ie-K558R mediated cochlear gene therapy and hair cell regeneration.

The cochlea consists of multiple types of cells, including hair cells, supporting cells and spiral ganglion neurons, and is responsible for converting mechanical forces into electric signals that enable hearing. Genetic and environmental factors can result in dysfunctions of cochlear and auditory systems. In recent years, gene therapy has emerged as a promising treatment in animal deafness models. One major challenge of the gene therapy for deafness is to effectively deliver genes to specific cells of cochleae. Here, we screened and identified an AAV-ie mutant, AAV-ie-K558R, that transduces hair cells and supporting cells in the cochleae of neonatal mice with high efficiency. AAV-ie-K558R is a safe vector with no obvious deficits in the hearing system. We found that AAV-ie-K558R can partially restore the hearing loss in Prestin KO mice and, importantly, deliver Atoh1 into cochlear supporting cells to generate hair cell-like cells. Our results demonstrate the clinical potential of AAV-ie-K558R for treating the hearing loss caused by hair cell death.

Non-contact optical characterization of negative pressure in hydrogel voids and microchannels.

Negative pressure in water under tension, as a thermodynamic non-equilibrium state, has facilitated the emergence of innovative technologies on microfluidics, desalination, and thermal management. However, the lack of a simple and accurate method to measure negative pressure hinders further in-depth understanding of the properties of water in such a state. In this work, we propose a non-contact optical method to quantify the negative pressure in micron-sized water voids of a hydrogel film based on the microscale mechanical deformation of the hydrogel itself. We tested three groups of hydrogel samples with different negative pressure inside, and the obtained results fit well with the theoretical prediction. Furthermore, we demonstrated that this method can characterize the distribution of negative pressure, and can thus provide the possibility of investigation of the flow behavior of water in negative pressure. These results prove this technique to be a promising approach to characterization of water under tension and for investigation of its properties under negative pressure.

Interaction-Temporal GCN: A Hybrid Deep Framework For Covid-19 Pandemic Analysis.

The Covid-19 pandemic is still spreading around the world and seriously imperils humankind's health. This swift spread has caused the public to panic and look to scientists for answers. Fortunately, these scientists already have a wealth of data-the Covid-19 reports that each country releases, reports with valuable spatial-temporal properties. These data point toward some key actions that humans can take in their fight against Covid-19. Technically, the Covid-19 records can be described as sequences, which represent spatial-temporal linkages among the data elements with graph structure. Therefore, we propose a novel framework, the Interaction-Temporal Graph Convolution Network (IT-GCN), to analyze pandemic data. Specifically, IT-GCN introduces ARIMA into GCN to model the data which originate on nodes in a graph, indicating the severity of the pandemic in different cities. Instead of regular spatial topology, we construct the graph nodes with the vectors via ARIMA parameterization to find out the interaction topology underlying in the pandemic data. Experimental results show that IT-GCN is able to capture the comprehensive interaction-temporal topology and achieve well-performed short-term prediction of the Covid-19 daily infected cases in the United States. Our framework outperforms state-of-art baselines in terms of MAE, RMSE and MAPE. We believe that IT-GCN is a valid and reasonable method to forecast the Covid-19 daily infected cases and other related time-series. Moreover, the prediction can assist in improving containment policies.

Polymer-Water Interaction Enabled Intelligent Moisture Regulation in Hydrogels.

The water-vapor transition is critical for hydrogels in a collection of applications. However, how the polymer-water interaction along with the nature of the structure affect the macroscopic water-vapor transition remains a challenging question to answer. In this work, we tested the moisture transfer behaviors of a series of hydrogels at different humidities and found some hydrogels capable of lowering their surface vapor pressure to stop dehydration at low humidity and absorbing water from ambient air to recover toward initial states at high humidity. Through molecular dynamic simulations, we demonstrate that water inside these hydrogels undergoes increasing intensive intermolecular bonding during evaporation. The increased intermolecular bonding reduces the vapor pressure of the hydrogels and leads to the self-regulation. More interestingly, we demonstrate the self-regulation is closely related to the Young's modulus of hydrogels. These results provide further insight into the mechanism of the water-vapor transition in hydrogels and show potential in a broad range of future applications.

Adsorption and dehydrogenation of C2-C6n-alkanes over a Pt catalyst: a theoretical study on the size effects of alkane molecules and Pt substrates.

Adsorption and dehydrogenation of C2-C6n-alkanes are investigated on a Pt substrate using density functional theory (DFT) calculations, and the size effects of alkane molecules and Pt substrates are discussed in detail. The Pt(111) surface and Pt55 cluster are chosen to represent large and small Pt nanoparticles, respectively. The C2-C6 straight-chain alkanes show no site preference on Pt(111) drifting over the surface, but prefer to locate along the edge sites of Pt55. Our results suggest that a linear relationship holds for the adsorption energies of n-alkanes against the chain length on Pt(111), in accordance with the experimental observations. Pt55 also exhibits a similar linear relationship for n-alkanes but with larger adsorption energies due to the low-coordinated Pt atoms at the edge site. For the two-step dehydrogenation from alkanes to alkenes, the first dehydrogenation reaction is the rate-determining step (RDS) on Pt(111), and a larger size of alkane molecule will lead to a lower dehydrogenation activity. While on Pt55, no RDS is present and the dehydrogenation activity oscillates slightly as the chain length of n-alkane increases. Generally, Pt55 involves lower energy barriers for most dehydrogenation steps compared to Pt(111), indicating that small Pt particles with more low-coordinated Pt atoms are more active towards alkane dehydrogenation. In addition, a clear BEP relationship is identified for all the dehydrogenation reactions of C2-C6n-alkanes on Pt substrates, and this linear relationship is independent of the particle size of the Pt substrate and the chain length of alkanes.

PFOS-induced placental cell growth inhibition is partially mediated by lncRNA H19 through interacting with miR-19a and miR-19b.

Perfluorooctane sulfonic acid (PFOS), a persistent environmental pollutant, has been associated with decreased birth weight. The dysregulation of long non-coding RNA (lncRNA) H19 has been implicated in pregnancy complications such as intra-uterine growth retardation (IUGR), preeclampsia (PE), however, the expression and function of H19 in PFOS-exerted detrimental effects in the placenta remains to be unveiled. Here, we explored the role of H19 in PFOS-induced placental toxicity. Results showed that PFOS caused decreased cell growth in human HTR-8/SVneo cells. Expression of H19 was increased, while miR-19a and miR-19b expression were decreased in mice placenta tissues and in HTR-8/SVneo cells exposed to PFOS. A significant hypomethylation was observed at the H19 promoter in the placentas of mice that were gestational exposed to high dose of PFOS. H19 was confirmed to bind with miR-19a and miR-19b, targeting SMAD4. Furthermore, H19 appeared to partially improve the cell growth of HTR-8/SVneo cells exposed to PFOS via upregulation of miR-19a and miR-19b. In summary, our findings revealed that H19/miR-19a and miR-19b/SMAD4 axis exerted important functions in PFOS-induced placenta cell toxicity.

Calibration of Linear Time-Varying Frequency Errors for Distributed ISAR Imaging Based on the Entropy Minimization Principle.

The inevitable frequency errors owing to the frequency mismatch of a transmitter and receiver oscillators could seriously deteriorate the imaging performance in distributed inverse synthetic aperture radar (ISAR) system. In this paper, for this issue, a novel method is proposed to calibrate the linear time-varying frequency errors (LTFE) between the transmitting node and the receiving node. The cost function is constructed based on the entropy minimization principle and the problem of LTFE calibration is transformed into cost function optimization. The frequency error coefficient, which minimizes the image entropy, is obtained by searching optimum solution in the solution space of cost function. Then, the original signal is calibrated by the frequency error coefficient. Finally, the effectiveness of the proposed method is demonstrated by simulation and real-data experiments.

Effects of γ-Irradiation on the Molecular Structures and Functions of Human Serum Albumin.

In this paper, we use spectroscopic methods (fluorescence spectroscopy, UV absorption spectroscopy, and circular dichroism (CD) spectroscopy) to elucidate the effects of reactive oxygen species generated by γ-irradiation on the molecular properties of human serum albumin (HSA). The results of fluorescence spectroscopy indicated that oxidation by γ-irradiation can lead to conformational changes of HSA. Data of CD spectra suggested that with the increase of radiation dose the percentage of α-helix in HSA has decreased. The determination of protein hydrophobicity showed that the effective hydrophobicity of HSA decreased up to 62% compared to the native HSA solution due to the exposure to the γ-irradiation. Furthermore, small changes in the esterase-like activity of HSA were introduced because of oxidation. The content of bityrosine increased markedly, suggesting that the oxidized HSA was aggregated. Moreover, there was no obvious change in the molecular properties of HSA with low γ-irradiation dose. Changes happened when the irradiation dose exceeded 200 Gy.

Evaluation on the Toxic Effects of NanoAg to Catalase.

Protein is the functional actor of life. Research on protein damage induced by nanomaterials may give insight into the toxicity mechanisms of nanoparticles. Studying nano silver over the impact of the structure and function of catalase (CAT) at the molecular level, is of great significance for a comprehensive evaluation of their toxic effects. The toxic effects of nanoAg on catalase were thoroughly investigated using steady state and time resolved fluorescence quenching measurements, ultraviolet-visible absorption spectroscopy, resonance light scattering spectroscopy (RLS), circular dichroism spectroscopy (CD) and transmission electron microscopy (TEM). NanoAg could decrease the amount of alpha-helix and increase the beta sheet structure, leading to loose the skeleton structure of catalase. The characteristic fluorescence of catalase was obviously quenched, which showed the exposal of internal hydrophobic amino acids enhanced, and its quenching type is dynamic quenching. The result of RLS and TEM showed that the distribution and size of nanoAg become more uniform and smaller after their interaction, resulting in a decrease of RLS intensity. NanoAg could make the activity of catalase rise. By changing the structure of catalase, nanoAg increases its enzymatic activity to a certain extent, breaking down its balance in vivo, thereby affecting the normal physiological activities. NanoAg has obvious toxic effects on catalase. This paper provided a new perspective and method for the toxic effects of nanoAg to biological macromolecules; provided basic data and reference gist for the hygienics and toxicology studies of nanoAg. It is conducive to the toxicity prevention and control work of nanoAg, promoting nano-technology applied to human production and living better.

Dissection of the binding of hydrogen peroxide to trypsin using spectroscopic methods and molecular modeling.

Studies on the effects of environmental pollutants to protein in vitro has become a global attention. Hydrogen peroxide (H2O2) is used as an effective food preservative and bleacher in industrial production. The toxicity of H2O2 to trypsin was investigated by multiple spectroscopic techniques and the molecular docking method at the molecular level. The intrinsic fluorescence of trypsin was proved to be quenched in a static process based on the results of fluorescence lifetime experiment. Hydrogen bonds interaction and van der Waals forces were the main force to generate the trypsin-H2O2 complex on account of the negative ΔH(0) and ΔS(0). The binding of H2O2 changed the conformational structures and internal microenvironment of trypsin illustrated by UV-vis absorption, fluorescence, synchronous fluorescence, three-dimensional (3D) fluorescence and circular dichroism (CD) results. However, the binding site was far away from the active site of trypsin and the trypsin activity was only slightly affected by H2O2, which was further explained by molecular docking investigations.

Spectroscopic investigations on the interactions between isopropanol and trypsin at molecular level.

The toxicity of hydroxyl group of isopropanol to trypsin in aqueous solution was investigated by techniques including UV-visible absorption spectroscopy, fluorescence spectroscopy, circular dichroism (CD) spectroscopy, enzyme activity assay and molecular docking technology. The results of UV-visible absorption spectroscopy and CD spectra indicate that isopropanol could change the secondary structure of trypsin by increasing the content of α-helix and decreasing the content of ß-sheet. The tertiary structure of trypsin was also changed owing to the loss of environmental asymmetry of amino acid residues. Isopropanol bound into a hydrophobic cavity on the surface of trypsin by a hydrogen bond located between the hydrogen atom on the hydroxyl of isopropanol and the oxygen atoms on SER 214 and hydrophobic interaction, as the molecular docking results showed. In addition, isopropanol could affect the function of trypsin by increasing its catalytic activity.