标准模型下前向安全公钥加密方案的新构造

针对已有的可证安全的前向安全公钥加密方案仅满足较弱的选择明文安全性,难以满足实际应用的安全需求这一问题,提出了一个新的前向安全公钥加密方案,基于判定性截断q-ABDHE问题的困难性,该方案在标准模型下被证明满足选择密文安全性。在该方案中,解密算法的计算代价和密文的长度独立于系统时间周期总数。对比分析表明,该方案的整体性能优于已有的前向安全公钥加密方案。     

Gelable and Adhesive Powder for Lethal Non-Compressible Hemorrhage Control

Hemostatic powders are widely used in clinical and emergency situations but often exhibit low wet adhesion, cytotoxicity concerns, and do not work well for lethal non-compressible hemorrhage. Here a new kind of gelable and adhesive powder (GAP) is developed, which integrates chitosan microspheres (CM), tetra-armed poly(ethylene glycol) amine (Tetra-PEG-NH₂), and tetra-armed poly(ethylene glycol) succinimidyl succinate (Tetra-PEG-SS). Upon application to the wound site, the macroporous CM can rapidly absorb the interfacial liquids, and meanwhile, the hydrated GAP turns into hydrogel (crosslinking between Tetra-PEG-SS and CM/Tetra-PEG-NH₂) with stable and robust adhesion to the wet tissue though covalent bonding. The in vitro and in vivo results suggest that the GAP with optimized formulation exhibits strong tissue adhesive, high burst pressure, and enhanced blood clotting ability, as well as excellent biocompatibility and on-demand removal properties. A significantly improved hemostatic efficacy is demonstrated in the rat liver, spleen, and femoral artery injury models compared to that of the CM, commercial fibrin glue, and Yunnan Baiyao (YB). The GAP can also halt the severe bleeding from pig visceral organs. Overall, the proposed GAP has many advantages including good biocompatibility, rapid and effective hemostasis, low cost, and ease of use, making it as a promising hemostat for lethal non-compressible hemorrhage control.     

Combined Optical,Gravimetric, and Electrical Operando Investigation of Structural Variations in Polymeric Mixed Conductors

Bioelectronics based on organic mixed conductors offers tremendous application potential in biological interfacing, drug delivery systems, and neuromorphic devices. The ion injection and water swelling upon electrochemical switching can significantly change the molecular packing of polymeric mixed conductors and thus influence the device performance. Herein, we quantify ion and water injection, and analyze the change of microscopic molecular packing of typical polymeric mixed conducting materials, namely poly(3,4‑ethylenedioxythiophene) doped with poly(styrene sulfonate) (PEDOT:PSS) and poly(2-(3,3′-bis(2-(2-(2-methoxyethoxy)ethoxy) ethoxy)-[2,2′-bithiophen]-5-yl)thieno[3,2-b]thiophene) (p(g2T-TT)), by integrating electrochemical quartz crystal microbalance with dissipation monitoring, in situ charge accumulation spectroscopy, and electrical current-voltage measurement. The penetration of ions and water can lead to viscous and disordered microstructures in organic mixed conductors and the water uptake property plays a more dominant role in morphological disruption compared with ion uptake is demonstrated. This study demonstrates the potential application of the combined optical, gravimetric, and electrical operando platform in evaluating the structural kinetics of organic mixed conductors and highlights the importance of concertedly tuning the hydration process, structural integrity, and charge transport properties of organic mixed conductors in order to achieve high performance and stable bioelectronic devices.     

2D MoN1.2-rGO Stacked Heterostructures Enabled Water State Modification for Highly Efficient Interfacial Solar Evaporation

Improving interfacial solar evaporation performance is crucial for the practical application of this technology in solar-driven seawater desalination. Lowering evaporation enthalpy is one of the most promising and effective strategies to significantly improve solar evaporation rate. In this study, a new pathway to lower vaporization enthalpy by introducing heterogeneous interactions between hydrophilic hybrid materials and water molecules is developed. 2D MoN_1.2 nanosheets are synthesized and integrated with rGO nanosheets to form stacked MoN_1.2-rGO heterostructures with massive junction interfaces for interfacial solar evaporation. Molecular dynamics simulation confirms that atomic thick 2D MoN_1.2 and rGO in the MoN_1.2-rGO heterostructures simultaneously interact with water molecules, while the interactions are remarkably different. These heterogeneous interactions cause an imbalanced water state, which easily breaks the hydrogen bonds between water molecules, leading to dramatically lowered vaporization enthalpy and improved solar evaporation rate (2.6 kg m⁻² h⁻¹). This study provides a promising strategy for designing 2D-2D heterostructures to regulate evaporation enthalpy to improve solar evaporate rate for clean water production.     

Wearable Organic Electrochemical Transistor Array for Skin-Surface Electrocardiogram Mapping Above a Human Heart

Electrocardiogram (ECG) mapping can provide vital information in sports training and cardiac disease diagnosis. However, most electronic devices for monitoring ECG signals need to use multiple long wires, which limit their wearability and conformability in practical applications, while wearable ECG mapping based on integrated sensor arrays has been rarely reported. Herein, ultra-flexible organic electrochemical transistor (OECT) arrays used for wearable ECG mapping on the skin surface above a human heart are presented. QRS complexes of ECG signals at different recording distances and directions relative to the heart are obtained. Furthermore, the ECG signals are successfully analyzed by the devices before and after exercise, indicating potential applications in some sports training and fitness scenarios. The OECT arrays that can conveniently monitor spacial ECG signals in the heart region may find niche applications in wearable electronics and healthcare products in the future.     

A Hybrid Strategy-Based Ultra-Narrow Stretchable Microelectrodes with Cell-Level Resolution

Stretchable ultra-narrow (e.g., 10 µm in width) microelectrodes are crucial for the electrophysiological monitoring of single cells providing the fundamental understanding to the working mechanism of neuro network or other electrically functional cells. Current fabrication strategies either focus on the preparation of normal stretchable electrodes with hundreds of micrometers or millimeters in width by using inorganic conductive materials or develop conductive organic polymer gel for ultra-narrow electrodes which suffer from low stretchability and instability for long-term implantation, therefore, it is still highly desirable to explore bio-interfacial ultra-narrow stretchable inorganic electrodes. Herein, a hybrid strategy is reported to prepare ultra-narrow multi-channel stretchable microelectrodes without using photolithography or laser-assisting etching. A 10 µm × 10 µm monitoring window is fabricated with enhanced interfacial impedance by the special rough surface. The stretchability achieves to 120% for this 10 µm-width stretchable electrode. Supported by these superior properties, it is demonstrated that the stretchable microelectrodes can detect electrophysiological signals of single cells in vitro and collect electrophysiological signals more precisely in vivo. The reported strategy will open up the accessible preparation of the fine-size stretchable microelectrode. It will significantly improve the resolution of monitoring and stimulation of inorganic stretchable electrodes.     

An Artificial Motion and Tactile Receptor Constructed by Hyperelastic Double Physically Cross-Linked Silk Fibroin Ionoelastomer

Ionotronic artificial motion and tactile receptor (i-AMTR) is essential to realize an interactive human-machine interface. However, an i-AMTR that effectively mimics the composition, structure, mechanics, and multi-functionality of human skin, called humanoid i-AMTR, is yet to be developed. To bridge this technological gap, this study proposes a strategy that combines molecular structure design and function integration to construct a humanoid i-AMTR. Herein, a silk fibroin ionoelastomer (SFIE) with double cross-linked molecular structure is designed to mimic the composition and structure of human skin, thereby resolving the conflict of stretchability, softness, and resilience, suffered by many previously reported ionotronics. Functionally, electromechanical sensing and triboelectricity-based tactile perception are integrated into SFIE, to enable simultaneous perception of both motion and tactile inputs. By further leveraging the machine learning and Internet of Things (IoT) techniques, the proposed SFIE-based humanoid i-AMTR precisely senses the movement of human body and accurately sortball objects made of different materials. Notably, the success rate for 610 sorting tests reaches as high as 92.3%. These promising results essentially demonstrate a massive potential of humanoid i-AMTR in the fields of sorting robots, rehabilitation medicine, and augmented reality.     

Magnesium Gradient-Based Hierarchical Scaffold for Dual-Lineage Regeneration of Osteochondral Defect

Osteochondral regeneration remains a great challenge due to the limited self-healing ability and the complexity of its hierarchical structure and composition. Mg²⁺ and hypoxia are two effective modulators in boosting chondrogenesis. To this end, a double-layered scaffold (D) consisting of a hydrogel layer on a porous cryogel is fabricated to mimic the hierarchical structure of osteochondral tissue. An Mg²⁺ gradient is incorporated into the double-layered scaffold with hypoxia-mimicking deferoxamine (DFO) embedded in the hydrogel (D-Mg-DFO), which remarkably augments the dual-lineage regeneration of both cartilage and subchondral bone. The higher Mg²⁺ supplementation from the upper hydrogel, associated with its hypoxia-mimicking situation and small pore size, exhibits promotive effects on chondrogenic differentiation. The lower Mg²⁺ supplementation from the bottom cryogel, associated with its interconnected macroporous structure, achieves multiple contributions in stem cell migration from bone marrow cavity, matrix mineralization, and osteogenesis. Furthermore, rabbits’ trochlea osteochondral defects are established to evaluate the regenerative outcome. Compared to control scaffolds containing only Mg²⁺ or DFO, the D-Mg-DFO scaffold presents the best regenerative effect under the synergistic contribution of multiple factors. Overall, this work provides a new design of scaffold toward an effective repair of cartilage defect.     

基于砷化镓工艺的集成式功分器

A compact lumped integrated power divider with low insertion loss using 0.5 μm GaAs pHEMT technology is presented. The proposed power divider uses the π-type LC network for transmission line equivalence and a thin film resistor for isolation tuning simultaneously. The quality factor of the inductor is analyzed and synthesized for insertion-loss influence. The measured insertion loss is less than 0.5 dB when the operating frequency is within the range of 5.15-6.15 GHz. The return loss and isolation are better than 15 dB and 20 dB, respectively. The compact dimension of the power divider is as small as 0.9 × 0.85 mm^2. The measured results agree well with the simulated ones.     

Novel Red-Emitting Microwave-Assisted-Sintered LiSrPO4: Eu3+ Phosphors for Application in Near-UV White Light-Emitting Diodes

Novel red-emitting LiSr_1?x PO₄:xEu³⁺ phosphors with various concentrations (x = 0.03, 0.05, 0.07, 0.1) of Eu³⁺ ions were synthesized by microwave-assisted sintering at 1200°C for 3 h in air. The microstructural and luminescent characteristics of the LiSrPO₄:Eu³⁺ phosphors were investigated and are discussed here. x-Ray diffraction (XRD) results showed that the prepared LiSr_1?x PO₄:xEu³⁺ phosphors presented an impurity phase of Eu₂O₃ when the Eu³⁺ ions exceeded x = 0.05. Photoluminescence (PL) results showed a series of emission states ⁵D₀ → ⁷F₀, ⁵D₀ → ⁷F₁, ⁵D₀ → ⁷F₂, ⁵D₀ → ⁷F₃, and ⁵D₀ → ⁷F₄ (corresponding to the typical 4f → 4f intraconfiguration forbidden transitions of Eu³⁺) with a major emission peak at around 617 nm. The optimum concentration of Eu³⁺ for LiSr_1?x PO₄:xEu³⁺ prepared by microwave-assisted sintering was found to be 0.05. The lifetime values of LiSr_1?x PO₄:xEu³⁺ phosphors with doping concentrations of Eu³⁺ ions of 0.03, 0.05, 0.07, and 0.1 were found to be 3.32 ms, 3.30 ms, 2.84 ms, and 2.60 ms, respectively. Moreover, the chromaticity values (x, y) of all of the LiSr_1?x PO₄:xEu³⁺ phosphors were located in the red region (0.65, 0.34).