Skin-Inspired Multi-Modal Mechanoreceptors for Dynamic Haptic Exploration

Active sensing is a fundamental aspect of human and animal interactions with the environment, providing essential information about the hardness, texture, and tackiness of objects. This ability stems from the presence of diverse mechanoreceptors in the skin, capable of detecting a wide range of stimuli and from the sensorimotor control of biological mechanisms. In contrast, existing tactile sensors for robotic applications typically excel in identifying only limited types of information, lacking the versatility of biological mechanoreceptors and the requisite sensing strategies to extract tactile information proactively. Here, inspired by human haptic perception, a skin-inspired artificial 3D mechanoreceptor (SENS) capable of detecting multiple mechanical stimuli is developed to bridge sensing and action in a closed-loop sensorimotor system for dynamic haptic exploration. A tensor-based non-linear theoretical model is established to characterize the 3D deformation (e.g., tensile, compressive, and shear deformation) of SENS, providing guidance for the design and optimization of multimode sensing properties with high fidelity. Based on SENS, a closed-loop robotic system capable of recognizing objects with improved accuracy (≈96%) is further demonstrated. This dynamic haptic exploration approach shows promise for a wide range of applications such as autonomous learning, healthcare, and space and deep-sea exploration.

Deshielding Anions Enable Solvation Chemistry Control of LiPF6-Based Electrolyte toward Low-Temperature Lithium-Ion Batteries

Severe capacity decay under subzero temperatures remains a significant challenge for lithium-ion batteries (LIBs) due to the sluggish interfacial kinetics. Current efforts to mitigate this deteriorating interfacial behavior rely on high-solubility lithium salts (e.g., Lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), Lithium bis(fluorosulfonyl)imide (LiFSI))-based electrolytes to construct anion participated solvation structures. However, such electrolytes bring issues of corrosion on the current collector and increased costs. Herein, the most commonly used Lithium hexafluorophosphate (LiPF6) instead, to establish a peculiar solvation structure with a high ratio of ion pairs and aggregates by introducing a deshielding NO3 - additive for low-temperature LIBs is utilized. The deshielding anion significantly reduces the energy barrier for interfacial behavior at low temperatures. Benefiting from this, the graphite (Gr) anode retains a high capacity of ≈72.3% at -20 °C, which is far superior to the 32.3% and 19.4% capacity retention of counterpart electrolytes. Moreover, the LiCoO2/Gr full cell exhibits a stable cycling performance of 100 cycles at -20 °C due to the inhibited lithium plating. This work heralds a new paradigm in LiPF6-based electrolyte design for LIBs operating at subzero temperatures.

Hygroscopic Solutes Enable Non-van der Waals Electrolytes for Fire-Tolerant Dual-Air Batteries

Thermal safety issues of batteries have hindered their large-scale applications. Nonflammable electrolytes improved safety but solvent evaporation above 100 °C limited thermal tolerance, lacking reliability. Herein, fire-tolerant metal-air batteries were realized by introducing solute-in-air electrolytes whose hygroscopic solutes could spontaneously reabsorb the evaporated water solvent. Using Zn/CaCl2 -in-air/carbon batteries as a proof-of-concept, they failed upon burning at 631.8 °C but self-recovered then by reabsorbing water from the air at room temperature. Different from conventional aqueous electrolytes whose irreversible thermal transformation is determined by the boiling points of solvents, solute-in-air electrolytes make this transformation determined by the much higher decomposition temperature of solutes. It was found that stronger intramolecular bonds instead of intermolecular (van der Waals) interactions were strongly correlated to ultra-high tolerance temperatures of our solute-in-air electrolytes, inspiring a concept of non-van der Waals electrolytes. Our study would improve the understanding of the thermal properties of electrolytes, guide the design of solute-in-air electrolytes, and enhance battery safety.

Boosting Solid-State Reconversion Reactivity to Mitigate Lithium Trapping for High Initial Coulombic Efficiency

An initial Coulombic efficiency (ICE) higher than 90% is crucial for industrial lithium-ion batteries, but numerous electrode materials are not standards compliant. Lithium trapping, due to i) incomplete solid-state reaction of Li+ generation and ii) sluggish Li+ diffusion, undermines ICE in high-capacity electrodes (e.g., conversion-type electrodes). Current approaches mitigating lithium trapping emphasize ii) nanoscaling (<50 nm) to minimize Li+ diffusion distance, followed by severe solid electrolyte interphase formation and inferior volumetric energy density. Herein, this work accentuates i) instead, to demonstrate that the lithium trapping can be mitigated by boosting the solid-state reaction reactivity. As a proof-of-concept, ternary LiFeO2 anodes, whose discharged products contain highly reactive vacancy-rich Fe nanoparticles, can alleviate lithium trapping and enable a remarkable average ICE of ≈92.77%, much higher than binary Fe2 O3 anodes (≈75.19%). Synchrotron-based techniques and theoretical simulations reveal that the solid-state reconversion reaction for Li+ generation between Fe and Li2 O can be effectively promoted by the Fe-vacancy-rich local chemical environment. The superior ICE is further demonstrated by assembled pouch cells. This work proposes a novel paradigm of regulating intrinsic solid-state chemistry to ameliorate electrochemical performance and facilitate industrial applications of various advanced electrode materials.

Technology Roadmap for Flexible Sensors

Humans rely increasingly on sensors to address grand challenges and to improve quality of life in the era of digitalization and big data. For ubiquitous sensing, flexible sensors are developed to overcome the limitations of conventional rigid counterparts. Despite rapid advancement in bench-side research over the last decade, the market adoption of flexible sensors remains limited. To ease and to expedite their deployment, here, we identify bottlenecks hindering the maturation of flexible sensors and propose promising solutions. We first analyze challenges in achieving satisfactory sensing performance for real-world applications and then summarize issues in compatible sensor-biology interfaces, followed by brief discussions on powering and connecting sensor networks. Issues en route to commercialization and for sustainable growth of the sector are also analyzed, highlighting environmental concerns and emphasizing nontechnical issues such as business, regulatory, and ethical considerations. Additionally, we look at future intelligent flexible sensors. In proposing a comprehensive roadmap, we hope to steer research efforts towards common goals and to guide coordinated development strategies from disparate communities. Through such collaborative efforts, scientific breakthroughs can be made sooner and capitalized for the betterment of humanity.

Freestanding and Scalable Force-Softness Bimodal Sensor Arrays for Haptic Body-Feature Identification

Tactile technologies that can identify human body features are valuable in clinical diagnosis and human-machine interactions. Previously, cutting-edge tactile platforms have been able to identify structured non-living objects; however, identification of human body features remains challenging mainly because of the irregular contour and heterogeneous spatial distribution of softness. Here, freestanding and scalable tactile platforms of force-softness bimodal sensor arrays are developed, enabling tactile gloves to identify body features using machine-learning methods. The bimodal sensors are engineered by adding a protrusion on a piezoresistive pressure sensor, endowing the resistance signals with combined information of pressure and the softness of samples. The simple design enables 112 bimodal sensors to be integrated into a thin, conformal, and stretchable tactile glove, allowing the tactile information to be digitalized while hand skills are performed on the human body. The tactile glove shows high accuracy (98%) in identifying four body features of a real person, and four organ models (healthy and pathological) inside an abdominal simulator, demonstrating identification of body features of the bimodal tactile platforms and showing their potential use in future healthcare and robotics.

Wet-Adhesive On-Skin Sensors Based on Metal-Organic Frameworks for Wireless Monitoring of Metabolites in Sweat

Metal-organic frameworks (MOFs) with well-defined porous structures and tailored functionalities have been widely used in chemical sensing. However, the integration of MOFs with flexible electronic devices for wearable sensing is challenging because of their low electrical conductivity and fragile mechanical properties. Herein, a wearable sweat sensor for metabolite detection is presented by integrating an electrically conductive Ni-MOF with a flexible nanocellulose substrate. The MOF-based layered film sensor with inherent conductivity, highly porous structure, and active catalytic properties enables the selective and accurate detection of vitamin C and uric acid. More importantly, the lightweight sensor can conformably self-adhere to sweaty skin and exhibits high water-vapor permeability. Furthermore, a wireless epidermal nutrition tracking system for the in situ monitoring of the dynamics of sweat vitamin C is demonstrated, the results of which are comparable to those tested by high-performance liquid chromatography. This study opens a new avenue for integrating MOFs as the active layer in wearable electronic devices and holds promise for the future development of high-performance electronics with enhanced sensing, energy production, and catalytic capabilities through the implementation of multifunctional MOFs.

Mechano-Graded Electrodes Mitigate the Mismatch between Mechanical Reliability and Energy Density for Foldable Lithium-Ion Batteries

Flexible lithium-ion batteries (LIBs) with high energy density are highly desirable for wearable electronics. However, difficult to achieve excellent flexibility and high energy density simultaneously via the current approaches for designing flexible LIBs. To mitigate the mismatch, mechano-graded electrodes with gradient-distributed maximum allowable strain are proposed to endow high-loading-mass slurry-coating electrodes with brilliant intrinsic flexibility without sacrificing energy density. As a proof-of-concept, the up-graded LiNi_1/3 Mn_1/3 Co_1/3 O₂ cathodes (≈15 mg cm^-2 , ≈70 µm) and graphite anodes (≈8 mg cm^-2 , ≈105 µm) can tolerate an extremely low bending radius of 400 and 600 µm, respectively. Finite element analysis (FEA) reveals that, compared with conventionally homogeneous electrodes, the flexibility of the up-graded electrodes is enhanced by specifically strengthening the upper layer and avoiding crack initiation. Benefiting from this, the foldable pouch cell (required bending radius of ≈600 µm) successfully realizes a remarkable figure of merit (FOM, energy density vs bending radius) of 121.3 mWh cm^-3 . Moreover, the up-graded-electrodes-based pouch cells can deliver a stable power supply, even under various deformation modes, such as twisting, folding, and knotting. This work proposes new insights for harmonizing the mechanics and electrochemistry of energy storage devices to achieve high energy density under flexible extremes.

Strain-Driven Auto-Detachable Patterning of Flexible Electrodes

Flexible electrodes that are multilayer, multimaterial, and conformal are pivotal for multifunctional wearable electronics. Traditional electronic circuits manufacturing requires substrate-supported transfer printing, which limits their multilayer integrity and device conformability on arbitrary surfaces. Herein, a "shrinkage-assisted patterning by evaporation" (SHAPE) method is reported, by employing evaporation-induced interfacial strain mismatch, to fabricate auto-detachable, freestanding, and patternable electrodes. The SHAPE method utilizes vacuum-filtration of polyaniline/bacterial cellulose (PANI/BC) ink through a masked filtration membrane to print high-resolution, patterned, and multilayer electrodes. The strong interlayer hydrogen bonding ensures robust multilayer integrity, while the controllable evaporative shrinking property of PANI/BC induces mismatch between the strains of the electrode and filtration membrane at the interface and thus autodetachment of electrodes. Notably, a 500-layer substrateless micro-supercapacitor fabricated using the SHAPE method exhibits an energy density of 350 mWh cm^-2 at a power density of 40 mW cm^-2 , 100 times higher than reported substrate-confined counterparts. Moreover, a digital circuit fabricated using the SHAPE method functions stably on a deformed glove, highlighting the broad wearable applications of the SHAPE method.

Enabling the High-Voltage Operation of Layered Ternary Oxide Cathodes via Thermally Tailored Interphase

Layered ternary oxides LiNi_x Mn_y Co_z O₂ are promising cathode candidates for high-energy lithium-ion batteries (LIBs), but they usually suffer from the severe interfacial parasitic reactions at voltages above 4.3 V versus Li⁺ /Li, which greatly limit their practical capacities. Herein, using LiNi_1/3 Mn_1/3 Co_1/3 O₂ (NMC111) as the model system, a novel high-temperature pre-cycling strategy is proposed to realize its stable cycling in 3.0-4.5 V by constructing a robust cathode/electrolyte interphase (CEI). Specifically, performing the first five cycles of NMC111 at 55 °C helps to yield a uniform CEI layer enriched with fluorine-containing species, Li₂ CO₃ and poly(CO₃ ), which greatly suppresses the detrimental side reactions during extended cycling at 25 °C, endowing the cell with a capacity retention of 92.3% at 1C after 300 cycles, far surpassing 62.0% for the control sample without the thermally tailored CEI. This work highlights the critical role of temperature on manipulating the interfacial properties of cathode materials, opening a new avenue for developing high-voltage cathodes for Li-ion batteries.

Hygroscopic Chemistry Enables Fire-Tolerant Supercapacitors with a Self-Healable "Solute-in-Air" Electrolyte

High-temperature-induced fire is an extremely serious safety risk in energy storage devices; which can be avoided by replacing their components with nonflammable materials. However; these devices are still destroyed by the high-temperature decomposition; lacking reliability. Here, a fire-tolerant supercapacitor is further demonstrated that recovers after burning with a self-healable "solute-in-air" electrolyte. Using fire-tolerant electrodes and separator with a semiopen device configuration; hygroscopic CaCl₂ in the air ("CaCl₂ -in-air") is designed as a self-healable electrolyte; which loses its water solvent at high temperatures but spontaneously absorbs water from the air to recover by itself at low temperatures. The supercapacitor is disenabled at 500 °C; while it recovers after cooling in the air. Especially; it even recovers after burning at around 647 °C with enhanced performance. The study offers a self-healing strategy to design high-safety; high-reliability; and fire-tolerant supercapacitors; which inspires a promising way to deal with general fire-related risks.

A Mechanically Interlocking Strategy Based on Conductive Microbridges for Stretchable Electronics

Stretchable electronics incorporating critical sensing, data transmission, display and powering functionalities, is crucial to emerging wearable healthcare applications. To date, methods to achieve stretchability of individual functional devices have been extensively investigated. However, integration strategies of these stretchable devices to achieve all-stretchable systems are still under exploration, in which the reliable stretchable interconnection is a key element. Here, solderless stretchable interconnections based on mechanically interlocking microbridges are developed to realize the assembly of individual stretchable devices onto soft patternable circuits toward multifunctional all-stretchable platforms. This stretchable interconnection can effectively bridge interlayer conductivity with tight adhesion through both conductive microbridges and selectively distributed adhesive polymer. Consequently, enhanced stretchability up to a strain of 35% (R/R₀  ≤ 5) is shown, compared with conventional solder-assisted connections which lose electrical conduction at a strain of less than 5% (R/R₀  ≈ 30). As a proof of concept, a self-powered all-stretchable data-acquisition platform is fabricated by surface mounting a stretchable strain sensor and a supercapacitor onto a soft circuit through solderless interconnections. This solderless interconnecting strategy for surface-mountable devices can be utilized as a valuable technology for the integration of stretchable devices to achieve all-soft multifunctional systems.

Metal-Ion Oligomerization Inside Electrified Carbon Micropores and its Effect on Capacitive Charge Storage

Ion adsorption inside electrified carbon micropores is pivotal for the operation of supercapacitors. Depending on the electrolyte, two main mechanisms have been identified so far, the desolvation of ions in solvents and the formation of superionic states in ionic liquids. Here, it is shown that upon confinement inside negatively charged micropores, transition-metal cations dissolved in water associate to form oligomer species. They are identified using in situ X-ray absorption spectroscopy. The cations associate one with each other via hydroxo bridging, forming ionic oligomers under the synergic effect of spatial confinement and Coulombic screening. The oligomers display sluggish dissociation kinetics and accumulate upon cycling, which leads to supercapacitor capacitance fading. They may be dissolved by applying a positive potential, so an intermittent reverse cycling strategy is proposed to periodically evacuate micropores and revivify the capacitance. These results reveal new insights into ion adsorption and structural evolution with their effects on the electrochemical performance, providing guidelines for designing advanced supercapacitors.

Pangolin-Inspired Stretchable, Microwave-Invisible Metascale

Microwave-invisible devices are emerging as a valuable technology in various applications, including soft robotics, shape-morphing structures, and textural camouflages, especially in electronic countermeasures. Unfortunately, conventional microwave-absorbing metastructures and bulk absorbers are stretching confined, limiting their application in deformable or special-shaped targets. To overcome such limitations, a conceptually novel soft-rigid-connection strategy, inspired by the pangolin, is proposed. Pangolin-inspired metascale (PIMS), which is a kind of stretchable metamaterial consisting of an electromagnetic dissipative scale (EMD-scale) and elastomer, is rationally designed. Such a device exhibits robust microwave-absorbing capacity under the interference of 50% stretching. Besides, profiting from the covering effect and size-confined effect of EMD-scale, the out-of-plane indentation failure force of PIMS is at least 5 times larger than conventional device. As a proof of concept, the proposed device is conformally pasted on nondevelopable surfaces. For a spherical dome surface, the maximum radar cross-section (RCS) reduction of PIMS is 6.3 dB larger than that of a conventional device, while for a saddle surface, the bandwidth of 10 dB RCS reduction exhibits an increase of 83%. In short, this work provides a conceptually novel platform to develop stretchable, nondevelopable surface conformable functional devices.

Catheter lock solutions for reducing catheter-related bloodstream infections in paediatric patients: a network meta-analysis

BACKGROUND

Different catheter lock solutions (CLSs) are used to reduce catheter-related bloodstream infection (CRBSI) for paediatric patients with central venous catheters (CVCs), but the most effective CLS is unknown.

AIM

To compare the effectiveness of different CLSs for the prevention of CRBSI in paediatric patients.

METHODS

Potential studies were searched and selected through the PubMed, Embase, Web of Science and Cochrane Library up to May 2021. Randomized controlled trials that assessed the effects of CLSs for preventing CRBSI in paediatric patients were included. We performed a random-effects network meta-analysis to estimate risk ratio (RR) with 95% confidence interval (CI).

FINDINGS

Thirteen studies comprising 1335 patients were included in the network meta-analysis. Taurolidine + heparin was effective in the prevention of CRBSI compared with heparin in paediatric patients (RR: 0.21, 95% CI: 0.09-0.51). No significant difference was found between the other CLSs (such as vancomycin, ethanol, fusidic acid, amikacin, and amikacin and vancomycin) and heparin or between different intervention lock solutions for CRBSI prevention. Based on the surface under the cumulative ranking curve, taurolidine + heparin (85.3%) appeared to be the most effective solution for effectiveness on CRBSI prevention, followed by fusidic acid + heparin (77.0%) and amikacin + heparin (65.7%). There was no statistical global inconsistency among the included studies after design by treatment test (χ² = 2.22, P=0.137).

CONCLUSION

The study showed that taurolidine lock solution seemed to be the most effective for the prevention of CRBSI in paediatric patients. Well-designed randomized trials in paediatric patients are needed to provide more reliable evidence in the effectiveness of different CLSs.

Worldwide cancer statistics of adolescents and young adults in 2019: a systematic analysis of the Global Burden of Disease Study 2019

Background

The cancer burden in adolescents and young adults (AYAs) deserves more attention. However, global cancer statistics for AYAs are often presented as aggregates, concealing important heterogeneity. This study aimed to describe the worldwide profile of cancer incidence, mortality, and corresponding trends from 1990 to 2019 among 15-39-year olds by focusing on the patterns by age, sex, sociodemographic index (SDI), and regions.

Patients and methods

Global, regional, and country data on the number of cancer cases and cancer-related deaths for 29 cancer types were collected from the 2019 Global Burden of Disease (GBD) Study. We also summarized the results using five levels of the SDI and 21 GBD regions.

Results

In 2019, an estimated 1 335 100 new cancer cases and 397 583 cancer-related deaths occurred among AYAs worldwide. While the incidence rate increased mildly, the death rate decreased significantly between 1990 and 2019, with an estimated annual percentage change of 0.38 (95% confidence interval 0.36-0.39) and −0.93 (95% confidence interval −0.95 to −0.92), respectively. The cancer burden was disproportionally greater among women than among men. The cancer profiles varied substantially across geographical regions, with the highest burden being in South Asia and East Asia. Besides, the cancer incidence in the high SDI regions was four times higher than that in the low SDI regions; however, the mortality burden in the high SDI region was lower than that in the low SDI region, which reflected the differences in cancer profiles across SDI regions and the inferior outcomes in the low SDI regions.

Conclusion

This study updates the previous epidemiological data of the cancer burden of AYAs. The cancer burden in AYAs varied substantially according to age, sex, SDI, and geographical regions. These findings highlight that the specific cancer profile of AYA patients requires targeted cancer control measures to reduce the cancer burden in this age group.

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The cancer burden in AYAs varied substantially according to age, sex, SDI, and geographical regions.

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Cancer burden in AYAs was disproportionally greater among women than among men.

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Cancer profiles of AYAs varied across different geographical regions and SDI regions.

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Cancer burden in AYAs was still considerable in the low SDI regions.

Analysis of long non-coding RNA expression profiles in disuse osteoporosis using microarray and bioinformatics

Disuse osteoporosis (DOP) is one of the major consequences of long space flights. DOP also occurs in patients with spinal cord injuries and prolonged bedridden states that can have a severe impact on human health. Bone marrow mesenchymal stem cells (BMSCs) are multipotent stromal cells that play an important role in bone homeostasis. Long non-coding RNAs (lncRNAs) are involved in regulating osteogenic differentiation of BMSCs, and their abnormal expression might lead to the formation of orthopedic diseases. However, the specific mechanism of DOP has not yet been elucidated. All sequencing data were obtained from Gene Expression Omnibus (GEO) datasets. The limma package of R was applied to identify DEmRNAs and DElncRNAs. Pearson correlation coefficients (PCC) between DElncRNADEmRNA expression levels were calculated. Functional annotation was performed for DEmRNAs coexpressed with DElncRNAs. In addition, the Cytohubba plug-in in Cytoscape was applied to determine the top 10 hub genes. Finally, connectivity map (CMap) analysis was used to identify potential therapeutic drugs for DOP. The gene expression data, GSE100930 and GSE17696, were retrieved from the GEO database. A total of 2,212 differentially expressed mRNAs (DEmRNAs) and 22 differentially expressed lncRNAs (DElncRNAs) were obtained. Gene ontology (GO) functional terms, Kyoto Encyclopedia of Genes, and Genomes (KEGG) pathway enrichment analysis reveal 30 significant GO terms and 13 significant pathways. A coding-non-coding gene co-expression (CNC) network was constructed to study the potential role of hub-DElncRNAs and their co-expressed DEmRNAs in DOP. The lncRNAs, GSNAS1, SNHG12, and EPB41LA4A-AS1, were significant in the CNC network and potential regulators of DOP development. Three bioactive compounds (scoulerine, kinetin riboside, dexanabinol) with potential therapeutic significance for DOP were obtained through the Connectivity Map (CMAP) analysis. Our study revealed a new mechanism for a lineage shift of bone marrow mesenchymal stem cells under microgravity, and linked the function of protein-coding mRNAs with ncRNAs, which may contribute to the development of new therapies for DOP.

Wuyiencin produced by Streptomyces albulus CK-15 displays biocontrol activities against cucumber powdery mildew

AIMS

Wuyiencin is a nucleoside antibiotic produced by Streptomyces albulus CK-15. The aim of this study was to determine whether wuyiencin can be used, as a suitable alternative to chemical pesticides, to protect cucumbers (Cucumis sativus L.) from powdery mildew caused by Sphaerotheca fuliginea. Further, the mechanisms underlying the control of cucumber powdery mildew by S. albulus CK-15 were preliminarily elucidated.

METHODS AND RESULTS

Wuyiencin solutions of different concentrations were used to treat infected cucumber plants under greenhouse conditions. The results indicated that wuyiencin could significantly reduce powdery mildew disease incidence, with a maximum prevention efficacy of 94·38%. Further, scanning electron micrographs and enzyme assays showed that wuyiencin inhibited S. fuliginea spore growth and elicited the activity of plant systemic resistance-related enzymes. Additionally, real-time quantitative reverse transcription PCR suggested that wuyiencin can activate a salicylic acid-dependent plant defence response.

CONCLUSIONS

Wuyiencin produced by S. albulus CK-15 possessed antifungal effects and was able to mitigate cucumber powdery mildew disease via antagonistic action. Wuyiencin also induced defence responses in the plants.

SIGNIFICANCE AND IMPACT OF THE STUDY

These results reinforce the biotechnological potential of wuyiencin as both an antagonistic agent and an inducer of plant systemic resistance.

An artificial sensory neuron with visual-haptic fusion

Human behaviors are extremely sophisticated, relying on the adaptive, plastic and event-driven network of sensory neurons. Such neuronal system analyzes multiple sensory cues efficiently to establish accurate depiction of the environment. Here, we develop a bimodal artificial sensory neuron to implement the sensory fusion processes. Such a bimodal artificial sensory neuron collects optic and pressure information from the photodetector and pressure sensors respectively, transmits the bimodal information through an ionic cable, and integrates them into post-synaptic currents by a synaptic transistor. The sensory neuron can be excited in multiple levels by synchronizing the two sensory cues, which enables the manipulating of skeletal myotubes and a robotic hand. Furthermore, enhanced recognition capability achieved on fused visual/haptic cues is confirmed by simulation of a multi-transparency pattern recognition task. Our biomimetic design has the potential to advance technologies in cyborg and neuromorphic systems by endowing them with supramodal perceptual capabilities.

Viral Load Dynamics in Sputum and Nasopharyngeal Swab in Patients with COVID-19

Coronavirus disease 2019 (COVID-19) has caused a global pandemic associated with substantial morbidity and mortality. Nasopharyngeal swabs and sputum samples are generally collected for serial viral load screening of respiratory contagions, but temporal profiles of these samples are not completely clear in patients with COVID-19. We performed an observational cohort study at Renmin Hospital of Wuhan University, which involved 31 patients with confirmed COVID-19 with or without underlying diseases. We obtained samples from each patient, and serial viral load was measured by real-time quantitative polymerase chain reaction. We found that the viral load in the sputum was inclined to be higher than samples obtained from the nasopharyngeal swab at disease presentation. Moreover, the viral load in the sputum decreased more slowly over time than in the nasopharyngeal group as the disease progressed. Interestingly, even when samples in the nasopharyngeal swab turned negative, it was commonly observed that patients with underlying diseases, especially hypertension and diabetes, remained positive for COVID-19 and required a longer period for the sputum samples to turn negative. These combined findings emphasize the importance of tracking sputum samples even in patients with negative tests from nasopharyngeal swabs, especially for those with underlying conditions. In conclusion, this work reinforces the importance of sputum samples for SARS-CoV-2 detection to minimize transmission of COVID-19 within the community.

Mechanically Reinforced Localized Structure Design to Stabilize Solid-Electrolyte Interface of the Composited Electrode of Si Nanoparticles and TiO2 Nanotubes

Silicon anode with extremely high theoretical specific capacity (≈4200 mAh g^-1 ), experiences huge volume changes during Li-ion insertion and extraction, causing mechanical fracture of Si particles and the growth of a solid-electrolyte interface (SEI), which results in a rapid capacity fading of Si electrodes. Herein, a mechanically reinforced localized structure is designed for carbon-coated Si nanoparticles (C@Si) via elongated TiO₂ nanotubes networks toward stabilizing Si electrode via alleviating mechanical strain and stabilizing the SEI layer. Benefited from the rational localized structure design, the carbon-coated Si nanoparticles/TiO₂ nanotubes composited electrode (C@Si/TiNT) exhibits an ideal electrode thickness swelling, which is lower than 1% after the first cycle and increases to about 6.6% even after 1600 cycles. While for traditional C@Si/carbon nanotube composited electrode, the initial swelling ratio is about 16.7% and reaches ≈190% after 1600 cycles. As a result, the C@Si/TiNT electrode exhibits an outstanding capacity of 1510 mAh g^-1 at 0.1 A g^-1 with high rate capability and long-time cycling performance with 95% capacity retention after 1600 cycles. The rational design on mechanically reinforced localized structure for silicon electrode will provide a versatile platform to solve the current bottlenecks for other alloyed-type electrode materials with large volume expansion toward practical applications.

Predicting pungency and understanding the pungency mechanism of capsaicinoids using TOPS-MODE approach

Quantitative structure-property relationship (QSPR) models were developed for predicting the pungency of a set of capsaicinoids. Multiple linear regression (MLR) coupled with topological substructural molecular descriptor (TOPS-MODE) approach was used. The best MLR model based on only five orthogonalized TOPS-MODE variables allowed us to obtain a coefficient of determination of 0.954 on the training set. The predictive power of the model was validated through a test set and several external validation parameters. This showed that the TOPS-MODE descriptors weighted by bond dipole moments, van der Waals atomic radii, and the total solute hydrogen bond basicity affected pungency. The contributions of certain bonds and fragments to pungency were used to understand the pungency mechanism of capsaicinoids. The selected model can more accurately predict pungency of capsaicinoids compared than those found in the literature, and especially bring insights into the structural features and chemical factors related to pungency.

Retrospective Analysis of 2019-nCov-Infected Cases in Dongyang, Southeastern China

The 2019 novel coronavirus (2019-nCov) has caused increasing number of infected cases globally. This study was performed to analyze information regarding the transmission route and presence of viral nucleic acids on several clinical samples. Confirmed 2019-nCov-infected cases were identified in Dongyang and were treated according to guidelines for the diagnosis of 2019-nCov infection released by the National Health Commission. Information regarding the contacts that the infected people had was collected to determine whether it caused clustered cases. A series of successive nucleic acid examination of feces, oropharyngeal swabs, and sputum was also performed, and the results were analyzed. A total of 19 confirmed cases of 2019-nCov infection were identified in Dongyang, Zhejiang Province, China. Five cases showed severe symptoms, and the remaining ones showed mild manifestations. Ten cases infected from two asymptomatic individuals were clustered into two groups. Among 14 cases with consecutive nucleic acid test results, four patients showed positive results in feces after their negative conversion in oropharyngeal swabs. Asymptomatic individuals with the virus could cause 2019-nCov clustered cases, and the clustered cases may differ from sporadic cases on age and length of hospitalization. In addition, nucleic acids in feces last longer than those in oropharyngeal swabs.

Non-invasive prediction of fetal growth restriction by whole-genome promoter profiling of maternal plasma DNA: a nested case-control study

Objective

To predict fetal growth restriction (FGR) by whole‐genome promoter profiling of maternal plasma.

Design

Nested case–control study.

Setting

Hospital‐based.

Population or Sample

810 pregnancies: 162 FGR cases and 648 controls.

Methods

We identified gene promoters with a nucleosome footprint that differed between FGR cases and controls based on maternal plasma cell‐free DNA (cfDNA) nucleosome profiling. Optimal classifiers were developed using support vector machine (SVM) and logistic regression (LR) models.

Main outcome measures

Genes with differential coverages in promoter regions through the low‐coverage whole‐genome sequencing data analysis among FGR cases and controls. Receiver operating characteristic (ROC) analysis (area under the curve [AUC], accuracy, sensitivity and specificity) was used to evaluate the performance of classifiers.

Results

Through the low‐coverage whole‐genome sequencing data analysis of FGR cases and controls, genes with significantly differential DNA coverage at promoter regions (−1000 to +1000 bp of transcription start sites) were identified. The non‐invasive ‘FGR classifier 1’ (C_FGR1) had the highest classification performance (AUC, 0.803; 95% CI 0.767–0.839; accuracy, 83.2%) was developed based on 14 genes with differential promoter coverage using a support vector machine.

Conclusions

A promising FGR prediction method was successfully developed for assessing the risk of FGR at an early gestational age based on maternal plasma cfDNA nucleosome profiling.

Tweetable abstract

A promising FGR prediction method was successfully developed, based on maternal plasma cfDNA nucleosome profiling.

A promising FGR prediction method was successfully developed, based on maternal plasma cfDNA nucleosome profiling.

Dielectric Polarization in Inverse Spinel-Structured Mg2 TiO4 Coating to Suppress Oxygen Evolution of Li-Rich Cathode Materials

High-energy Li-rich layered cathode materials (≈900 Wh kg^-1 ) suffer from severe capacity and voltage decay during cycling, which is associated with layered-to-spinel phase transition and oxygen redox reaction. Current efforts mainly focus on surface modification to suppress this unwanted structural transformation. However, the true challenge probably originates from the continuous oxygen release upon charging. Here, the usage of dielectric polarization in surface coating to suppress the oxygen evolution of Li-rich material is reported, using Mg₂ TiO₄ as a proof-of-concept material. The creation of a reverse electric field in surface layers effectively restrains the outward migration of bulk oxygen anions. Meanwhile, high oxygen-affinity elements of Mg and Ti well stabilize the surface oxygen of Li-rich material via enhancing the energy barrier for oxygen release reaction, verified by density functional theory simulation. Benefited from these, the modified Li-rich electrode exhibits an impressive cyclability with a high capacity retention of ≈81% even after 700 cycles at 2 C (≈0.5 A g^-1 ), far superior to ≈44% of the unmodified counterpart. In addition, Mg₂ TiO₄ coating greatly mitigates the voltage decay of Li-rich material with the degradation rate reduced by ≈65%. This work proposes new insights into manipulating surface chemistry of electrode materials to control oxygen activity for high-energy-density rechargeable batteries.

Interfacial Lattice-Strain-Driven Generation of Oxygen Vacancies in an Aerobic-Annealed TiO2 (B) Electrode

Oxygen vacancies play crucial roles in defining physical and chemical properties of materials to enhance the performances in electronics, solar cells, catalysis, sensors, and energy conversion and storage. Conventional approaches to incorporate oxygen defects mainly rely on reducing the oxygen partial pressure for the removal of product to change the equilibrium position. However, directly affecting reactants to shift the reaction toward generating oxygen vacancies is lacking and to fill this blank in synthetic methodology is very challenging. Here, a strategy is demonstrated to create oxygen vacancies through making the reaction energetically more favorable via applying interfacial strain on reactants by coating, using TiO₂ (B) as a model system. Geometrical phase analysis and density functional theory simulations verify that the formation energy of oxygen vacancies is largely decreased under external strain. Benefiting from these, the obtained oxygen-deficient TiO₂ (B) exhibits impressively high level of capacitive charge storage, e.g., ≈53% at 0.5 mV s^-1 , far surpassing the ≈31% of the unmodified counterpart. Meanwhile, the modified electrode shows significantly enhanced rate capability delivering a capacity of 112 mAh g^-1 at 20 C (≈6.7 A g^-1 ), ≈30% higher than air-annealed TiO₂ and comparable to vacuum-calcined TiO₂ . This work heralds a new paradigm of mechanical manipulation of materials through interfacial control for rational defect engineering.

Interfacial Lattice-Strain-Driven Generation of Oxygen Vacancies in an Aerobic-Annealed TiO2 (B) Electrode

Oxygen vacancies play crucial roles in defining physical and chemical properties of materials to enhance the performances in electronics, solar cells, catalysis, sensors, and energy conversion and storage. Conventional approaches to incorporate oxygen defects mainly rely on reducing the oxygen partial pressure for the removal of product to change the equilibrium position. However, directly affecting reactants to shift the reaction toward generating oxygen vacancies is lacking and to fill this blank in synthetic methodology is very challenging. Here, a strategy is demonstrated to create oxygen vacancies through making the reaction energetically more favorable via applying interfacial strain on reactants by coating, using TiO₂ (B) as a model system. Geometrical phase analysis and density functional theory simulations verify that the formation energy of oxygen vacancies is largely decreased under external strain. Benefiting from these, the obtained oxygen-deficient TiO₂ (B) exhibits impressively high level of capacitive charge storage, e.g., ≈53% at 0.5 mV s^-1 , far surpassing the ≈31% of the unmodified counterpart. Meanwhile, the modified electrode shows significantly enhanced rate capability delivering a capacity of 112 mAh g^-1 at 20 C (≈6.7 A g^-1 ), ≈30% higher than air-annealed TiO₂ and comparable to vacuum-calcined TiO₂ . This work heralds a new paradigm of mechanical manipulation of materials through interfacial control for rational defect engineering.

Honeycomb-Lantern-Inspired 3D Stretchable Supercapacitors with Enhanced Specific Areal Capacitance

Traditional stretchable supercapacitors, possessing a thin electrode and a 2D shape, have limited areal specific areal capacitance and are incompatible with 3D wearables. To overcome the limitations of 2D stretchable supercapacitors, it is highly desirable to develop 3D stretchable supercapacitors with higher mass loading and customizable shapes. In this work, a new 3D stretchable supercapacitor inspired by a honeycomb lantern based on an expandable honeycomb composite electrode composed of polypyrrole/black-phosphorous oxide electrodeposited on carbon nanotube film is reported. The 3D stretchable supercapacitors possessing device-thickness-independent ion-transport path and stretchability can be crafted into customizable device thickness for enhancing the specific areal energy storage and integrability with wearables. Notably, a 1.0 cm thick rectangular-shaped supercapacitor shows enhanced specific areal capacitance of 7.34 F cm^-2 , which is about 60 times higher than that of the original 2D supercapacitor (120 mF cm^-2 ) at a similar discharge rate. The 3D supercapacitor can also maintain a capacitance ratio of 95% even under the reversible strain of 2000% after 10 000 stretch-and-release cycles, superior to state-of-the-art stretchable supercapacitors. The enhanced specific areal energy storage and the customizablility in shapes of the 3D stretchable supercapacitors show immense promise in a wide range of applications in stretchable and wearable electronics.

AID and TET2 co-operation modulates FANCA expression by active demethylation in diffuse large B cell lymphoma

Diffuse large B cell lymphoma (DLBCL) is traced to a mature B malignance carrying abnormal activation-induced cytidine deaminase (AID) expression. AID activity initially focuses on deamination of cytidine to uracil to generate somatic hypermutation and class-switch recombination of the immunoglobulin (Ig), but recently it has been implicated in DNA demethylation of genes required for B cell development and proliferation in the germinal centre (GC). However, whether AID activity on mutation or demethylation of genes involves oncogenesis of DLBCL has not been well characterized. Our data demonstrate that the proto-oncogene Fanconi anaemia complementation group A (FANCA) is highly expressed in DLBCL patients and cell lines, respectively. AID recruits demethylation enzyme ten eleven translocation family member (TET2) to bind the FANCA promoter. As a result, FANCA is demethylated and its expression increases in DLBCL. On the basis of our findings, we have developed a new therapeutic strategy to significantly inhibit DLBCL cell growth by combination of the proteasome inhibitor bortezomib with AID and TET2 depletion. These findings support a novel mechanism that AID has a crucial role in active demethylation for oncogene activation in DLBCL.

Expression and significance of peripheral myeloid-derived suppressor cells in chronic hepatitis B patients

BACKGROUND

Myeloid-derived suppressor cells (MDSCs) exert their suppressive effects on multiple immune response and contribute to the development of many diseases. However, limited data is available on the involvement of MDSCs in human chronic HBV infection.

OBJECTIVE

To investigate whether the progression of chronic HBV infection was associated with imbalance of MDSCs.

METHODS

The percentages of MDSCs, regulatory T (Treg), Th1 and Tc1 cells in the peripheral blood from chronic hepatitis B (CHB) patients and healthy controls (HC) were determined by flow cytometry. Plasma levels of IL-10, TGF-β and IFN-γ were measured using enzyme-linked immunosorbent assay. The potential association of the frequencies of MDSCs with clinical parameters was assessed.

RESULTS

The percentages of MDSCs and Treg cells were significantly higher in CHB patients than those in HC. The percentages of MDSCs were negatively correlated with Th1 cells. Increased plasma IL-10 level and decreased IFN-γ level were found in CHB patients compared with HC. Moreover, the frequencies of MDSCs and plasma IL-10 levels were positively correlated with serum HBV DNA loads, as well as liver function impairment.

CONCLUSION

The expanded peripheral MDSCs may contribute to poor viral clearance and disease progression during chronic HBV infection.