Influence of the Second-Phase Resin Structure on the Interfacial Shear Strength of Carbon Fiber/Epoxy Resin.

The toughening modification of epoxy resin has received widespread attention. The addition of the second-phase resin has a good toughening effect on epoxy resin. In order to investigate the effect of the second-phase resin on the interphase of composites, in this work the interfacial properties of carbon fiber (CF)/epoxy resin with the second-phase resin structure were investigated. Methodologies including surface structure observation, chemical characteristics, surface energy of the CF, and micro-phase structure characterization of resin were tested, followed by the micro-interfacial performance of CF/epoxy composites before and after hygrothermal treatment. The results revealed that the sizing process has the positive effect of increasing the interfacial bonding properties of CF/epoxy. From the interfacial shear strength (IFSS) test, the introduction of the second phase in the resin reduced the interfacial bonding performance between the CF and epoxy. After the hygrothermal treatment, water molecules diffused along the interfacial paths between the two resins, which in turn created defects and consequently brought about a reduction in the IFSS.

Flying Target Detection Technology Based on GNSS Multipath Signals.

In this study, a passive radar system that detects flying targets is developed in order to solve the problems associated with traditional flying target detection systems (i.e., their large size, high power consumption, complex systems, and poor battlefield survivability). On the basis of target detection, the system uses the multipath signal (which is usually eliminated as an error term in navigation and positioning), enhances it by supporting information, and utilizes the multi-source characteristics of ordinary omnidirectional global navigation satellite system (GNSS) signals. The results of a validation experiment showed that the system is able to locate a passenger airplane and obtain its flight trajectory using only one GNSS receiving antenna. The system is characterized by its light weight (less than 5 kg), low power consumption, simple system, good portability, low cost, and 24/7 and all-weather work. It can be installed in large quantities and has good prospects for development.

3 directional Inception-ResUNet: Deep spatial feature learning for multichannel singing voice separation with distortion.

Singing voice separation on robots faces the problem of interpreting ambiguous auditory signals. The acoustic signal, which the humanoid robot perceives through its onboard microphones, is a mixture of singing voice, music, and noise, with distortion, attenuation, and reverberation. In this paper, we used the 3D Inception-ResUNet structure in the U-shaped encoding and decoding network to improve the utilization of the spatial and spectral information of the spectrogram. Multiobjectives were used to train the model: magnitude consistency loss, phase consistency loss, and magnitude correlation consistency loss. We recorded the singing voice and accompaniment derived from the MIR-1K dataset with NAO robots and synthesized the 10-channel dataset for training the model. The experimental results show that the proposed model trained by multiple objectives reaches an average NSDR of 11.55 dB on the test dataset, which outperforms the comparison model.

Thermal Stress Analysis and Control Method for Surface Acoustic Wave Atomizer.

To prevent the potential failure of the surface acoustic wave (SAW) atomizer caused by the concentration of thermal stresses, this study investigates the thermal elevation process inherent to the operation of the surface wave atomizer. Subsequently, a method for temperature regulation is proposed. By collecting the temperature rise data of SAW atomizers with water, olive oil, and glycerol at 5/6/7 Watts (W) of power, the temperature curves of the atomizer surface under different conditions are obtained, and the stress changes in the working process are simulated additionally. The results indicate that although the stress generated by surface acoustic wave atomizers varies for different media, there is always a problem of rapid heating during the initial working stage in all cases. To address the above issues, this study analyzed the time when the maximum stress occurred and proposed control methods based on experimental data. The simulation results show that by controlling the driving power within 4 s after the start of atomization, the problem of excessive stress during the heating stage can be avoided. Finally, the feasibility of the control method was verified through a simple power control method (limiting the driving power to 3 W in the first 2 s), proving that this method can effectively reduce the thermal stress during the working process of the atomizer and prevent the atomizer from cracking.

Positive Chemotaxis of CREKA-Modified Ceria@Polydopamine Biomimetic Nanoswimmers for Enhanced Penetration and Chemo-photothermal Tumor Therapy.

Tumor interstitial pressure represents the greatest barrier against drug diffusion into the depth of the tumor. Biometric nanomotors highlight the possibility of enhanced deep penetration and improve cellular uptake. However, control of their directionality remains difficult to achieve. Herein, we report cysteine-arginine-glutamic acid-lysine-alanine (CREKA)-modified ceria@polydopamine nanobowls as tumor microenvironment-fueled nanoscale motors for positive chemotaxis into the tumor depth or toward tumor cells. Upon laser irradiation, this nanoswimmer rapidly depletes the tumor microenvironment-specific hydrogen peroxide (H2O2) in the nanobowl, contributing to a self-generated gradient and subsequently propulsion (9.5 µm/s at 46 °C). Moreover, the asymmetrical modification of CREKA on nanobowls could automatically reconfigure the motion direction toward tumor depth or tumor cells in response to receptor-ligand interaction, leading to a deep penetration (70 µm in multicellular spheroids) and enhanced antitumor effects over conventional nanomedicine-induced chemo-photothermal therapy (tumor growth inhibition rate: 84.2% versus 56.9%). Thus, controlling the direction of nanomotors holds considerable potential for improved antitumor responses, especially in solid tumors with high tumor interstitial pressure.

Comparison of Simulated and Measured Power of the Earth-Space Link for Satellite-Based AIS Signals.

This research aims to analyze the impact of the Earth-Space link on the Automatic Identification System (AIS) signals of ships. To achieve this, we established a simulation system that measures the receiving power of AIS signals via satellite platforms. We validated the system by utilizing observation data from Tiantuo-5. Through this simulation, we quantitatively analyzed the effects of ionospheric TEC (Total Electron Content) and space loss on the received power. During the processing of observation data, we construct a geometric propagation model utilizing the measured positions of both the satellite and the ship. We then calculate the antenna gain and remove any system errors. Additionally, we eliminate the deviation of elevation and azimuth angles caused by satellite motion. This allows us to determine the actual power of different ships reaching the receiving platform. Upon comparing the measured power data with the simulated power, it was noted that both exhibited an increasing trend as the elevation angle increased. This led to an RMSE (Root Mean Square Error) result of approximately one, indicating the accuracy of the simulation system. These findings hold significant implications for analyzing interference factors in satellite-ground links.

Anisotropic, Hydrogel Microparticles as pH-Responsive Drug Carriers for Oral Administration of 5-FU.

In the last 20 years, the development of stimuli-responsive drug delivery systems (DDS) has received great attention. Hydrogel microparticles represent one of the candidates with the most potential. However, if the role of the cross-linking method, polymer composition, and concentration on their performance as DDS has been well-studied, still, a lot needs to be explained regarding the effect caused by the morphology. To investigate this, herein, we report the fabrication of PEGDA-ALMA-based microgels with spherical and asymmetric shapes for 5-fluorouracil (5-FU) on-demand loading and in vitro pH-triggered release. Due to anisotropic properties, the asymmetric particles showed an increased drug adsorption and higher pH responsiveness, which in turn led to a higher desorption efficacy at the target pH environment, making them an ideal candidate for oral administration of 5-FU in colorectal cancer. The cytotoxicity of empty spherical microgels was higher than the cytotoxicity of empty asymmetric microgels, suggesting that the gel network's mechanical proprieties of anisotropic particles were a better three-dimensional environment for the vital functions of cells. Upon treatment with drug-loaded microgels, the HeLa cells' viability was lower after incubation with asymmetric particles, confirming a minor release of 5-FU from spherical particles.

Analysis of risk factors of hepatocellular carcinoma and establishment of a clinical prognosis model.

Liver cancer is a common malignancy of the digestive system. Hepatocellular carcinoma (HCC) accounts for the most majority of these tumors and it has brought a heavy medical burden to underdeveloped countries and regions. Many factors affect the prognosis of HCC patients, however, there is no specific statistical model to predict the survival time of clinical patients. This study derived a risk factor signature of HCC and reliable clinical prediction model by statistically analyzing The Surveillance, Epidemiology, and End Results (SEER) database patient information using an open source package in the python environment.

Effective decolonization strategy for mupirocin-resistant Staphylococcus aureus by TPGS-modified mupirocin-silver complex.

The widespread utilization of mupirocin to treat methicillin-resistant Staphylococcus aureus (MRSA)-caused infectious diseases has led to the emergence of mupirocin-resistant Staphylococcus aureus (MuRSA), posing a serious global medical threat. In order to counteract MuRSA, we develop a d-α-tocopherol polyethylene glycol 1000 succinate (TPGS) modified mupirocin and silver complex (TPGS/Mup-Ag) to combat MuRSA. The surfactivity of TPGS endows Mup-Ag with a homogeneous and small particle size (∼16 â€‹nm), which significantly enhances bacterial internalization. Silver ions are released from the mupirocin-Ag complex (Mup-Ag) to exert a synergistic antibacterial activity with mupirocin. Results manifest that our strategy reduces the concentration of mupirocin that induces 50% bacterial death from about 1000 â€‹µmol/mL to about 16 â€‹µmol/mL. In vitro bacterial infection model suggests that TPGS/Mup-Ag can not only eliminate both intracellular and inhibit bacterial adhesion, but also living cells are not affected. Results of in vivo experiments demonstrate that TPGS/Mup-Ag can effectively inhibit the progression of skin infection and accelerate wound healing, as well as alleviate systemic inflammation in both the subcutaneous infection model and the wound infection model. Furthermore, this study may contribute to the development of therapeutic agents for antibiotic-resistant bacteria and offer ideas for silver-based bactericides.

Biomimetic Melanosomes Promote Orientation-Selective Delivery and Melanocyte Pigmentation in the H2O2-Induced Vitiligo Mouse Model.

Extremely limited drug retention and depigmentation represent the greatest barriers against vitiligo treatment advancement. Here, inspired by biological melanosomes, the primary melanin transporter, we developed biomimetic melanosomes to combat reactive oxygen species (ROS)-mediated melanocyte damage and depigmentation. Briefly, methylprednisolone (MPS) and melanin-mimicking polydopamine (PDA) were encapsulated inside lysine-proline-valine (KPV)-modified deformable liposomes (KPV-Lipos). Owing to their phospholipid bilayer flexibility and the specific affinity for melanocortin 1 receptor (MC1R), KPV-Lipos exhibited 1.43-fold greater skin deposition than traditional liposomes. The binding of KPV and its receptor also contributed to activating the cAMP-tyrosinase (TYR) signaling pathway, improving the endogenous melanin content. In addition, PDA mimicked melanosomes as it effectively increased the exogenous melanin content and scavenged ROS. Meanwhile, MPS inhibited inflammatory cytokine secretion, limiting the depigmented area. Ultimately, the biomimetic melanosomes affected the skin color of mice with H2O2-induced vitiligo. These melanosomes show potential as a universal platform for the self-supply of melanin by self-driven melanin synthesis with exogenous supplementation. Furthermore, this study offers ideas for the production of artificial packed melanosome substitutes for melanocyte-related diseases.

Effect of Sizing Agents on Surface Properties of Carbon Fibers and Interfacial Adhesion of Carbon Fiber/Bismaleimide Composites.

Physicochemical, surface, and mechanical properties of three batches of T800 grade carbon fibers (CFs) treated with three kinds of sizing agents and Toray T800H CFs were characterized to study the effect of sizing agents on surface properties. Scanning electron microscopy for morphology, atomic force microscopy calculations, and results for the content of sizing agents showed that sizing agent B improved the surface roughness and CFs with high content of sizing agent always presented small surface roughness in a certain content range 1.2-1.6%. Surface energy of CFs was calculated by Young's contact angle using the test results with water and glycol, and contact angles with LY-1 and modified-AC531 were also acquired. The results proved that CFs of sizing agent group B had the highest average surface energy and the lowest average contact angles with both LY-1 and modified-AC531. From both single-filament and tensile strength test results, the average strength of CFs of sizing agent group B was found to be the lowest, which indicated that sizing agent B had an influence on tensile strength decrease of T800 grade CFs. Comparing the results of interfacial shear strength both in a natural dry state and after hygrothermal treatment, high surface energy was found to be the key element to obtain high interfacial adhesion between T800 grade CFs and bismaleimide, and high surface roughness and low contact angle also played important roles. Among sizing agents A, B, and C, A had an effect on the interfacial shear strength decrease of CFs in the natural dry state, while C had that after hygrothermal treatment.

ROS-responsive chitosan-SS31 prodrug for AKI therapy via rapid distribution in the kidney and long-term retention in the renal tubule.

The development of drugs with rapid distribution in the kidney and long-term retention in the renal tubule is a breakthrough for enhanced treatment of acute kidney injury (AKI). Here, l-serine-modified chitosan (SC) was synthesized as a potential AKI kidney-targeting agent due to the native cationic property of chitosan and specific interaction between kidney injury molecule-1 (Kim-1) and serine. Results indicated that SC was rapidly accumulated and long-term retained in ischemia-reperfusion-induced AKI kidneys, especially in renal tubules, which was possibly due to the specific interactions between SC and Kim-1. SC-TK-SS31 was then prepared by conjugating SS31, a mitochondria-targeted antioxidant, to SC via reactive oxygen species (ROS)-sensitive thioketal linker. Because of the effective renal distribution combined with ROS-responsive drug release behavior, the administration of SC-TK-SS31 led to an enhanced therapeutic effect of SS31 by protecting mitochondria from damage and reducing the oxidative stress, inflammation, and cell apoptosis.

NIR-Triggered Sequentially Responsive Nanocarriers Amplified Cascade Synergistic Effect of Chemo-Photodynamic Therapy with Inspired Antitumor Immunity.

A desirable cancer therapeutic strategy is supposed to have effective ability to not only exert maximum anticancer ability but also inspire antitumor immunity for preventing tumor relapse and metastasis. During this research, multifunctional upconversion nanoparticles (UCNPs) coated by ROS-responsive micelles are prepared for tumor targeting and near-infrared (NIR)-triggered photodynamic therapy (PDT)-combined synergistic effect of chemotherapy. Moreover, both PDT and chemotherapy agents could activate antitumor immunity via inducing immunogenic cell death with CD8+ and CD4+ T cells infiltrating in tumors. Through the experiments, intravenous administration of multifunctional nanocarriers with noninvasive NIR irradiation destroys the orthotopic tumors and efficiently suppresses lung metastasis in a metastatic triple-negative breast cancer model by cascade-amplifying chemo-PDT and systemic antitumor immunity. In conclusion, this study provides prospective chemo-PDT with inspired antitumor immunity for metastatic cancer treatment.

Microstructure Engineering of Fe/Fe3C-Decorated Metal-Nitrogen-Carbon Mesoporous Nanospheres via a Self-Template Method for Enhancing Oxygen Reduction Activity.

We report a self-template and facile pyrolysis method to synthesize Fe/Fe3C-decorated metal-nitrogen-carbon mesoporous nanospheres, of which preserved plum-like and hollow structures can be simply engineered via controlling the thickness of the outermost polydopamine layer in the precursors. The preserved plum-like structure is demonstrated to show a large electrochemically active surface area and facilitate fast charge transfer, in comparison with the hollow one. The catalytic activities of metal-nitrogen-carbon and nitrogen-doped carbon active sites in the outer carbon layer toward oxygen reduction are improved under the activation of the encased Fe species. Hence, preserved plum-like structures exhibit excellent catalytic kinetics toward the oxygen reduction reaction in alkaline media. The mass activity of 21.0 mA mgcatalyst-1 at 0.9 V vs RHE is achieved and the half-wave potential is 50 mV more positive than that of the Pt/C catalyst with the same mass loading. Moreover, the outer carbon layer endows the tolerance of strong acidic and alkaline environments, resulting in good durability. Our study proposes a simple strategy for the rational design of novel transition metal carbide-based catalysts, making it a promising candidate for replacing platinum-group metal catalysts in low-temperature fuel cells.

Recent Progress and Future Directions: The Nano-Drug Delivery System for the Treatment of Vitiligo.

Vitiligo is a depigmentation disease that seriously affects the physical health, mental health and quality of life of a patient. Therapeutic aim at control immunoreaction by relieving oxidative stress. Unfortunately, the cuticle barrier function and lack of specific accumulation lead to unsatisfactory therapeutic outcomes and side effects. The introduction and innovation of nanotechnology offers inspiration and clues for the development of new strategies to treat vitiligo. However, not many studies have been done to interrogate how nanotechnology can be used for vitiligo treatment. In this review, we summarize and analyze recent studies involving nano-drug delivery systems for the treatment of vitiligo, with a special emphasis on liposomes, niosomes, nanohydrogel and nanoparticles. These studies made significant progress by either increasing drug loading efficiency or enhancing penetration. Based on these studies, there are three proposed principles for topical nano-drug delivery systems treatment of vitiligo including the promotion of transdermal penetration, enhancement of drug retention and facilitation of melanin regeneration. The presentation of these ideas may provide inspirations for the future development of topical drug delivery systems that will conquer vitiligo.

ROS-responsive nano-drug delivery system combining mitochondria-targeting ceria nanoparticles with atorvastatin for acute kidney injury.

Acute kidney injury (AKI) caused by sepsis is a serious disease which mitochondrial oxidative stress and inflammatory play a key role in its pathophysiology. Ceria nanoparticles hold strong and recyclable reactive oxygen species (ROS)-scavenging activity, have been applied to treat ROS-related diseases. However, ceria nanoparticles can't selectively target mitochondria and the ultra-small ceria nanoparticles are easily agglomerated. To overcome these shortcomings and improve therapeutic efficiency, we designed an ROS-responsive nano-drug delivery system combining mitochondria-targeting ceria nanoparticles with atorvastatin for acute kidney injury. Methods: Ceria nanoparticles were modified with triphenylphosphine (TCeria NPs), followed by coating with ROS-responsive organic polymer (mPEG-TK-PLGA) and loaded atorvastatin (Atv/PTP-TCeria NPs). The physicochemical properties, in vitro drug release profiles, mitochondria-targeting ability, in vitro antioxidant, anti-apoptotic activity and in vivo treatment efficacy of Atv/PTP-TCeria NPs were examined. Results: Atv/PTP-TCeria NPs could accumulate in kidneys and hold a great ability to ROS-responsively release drug and TCeria NPs could target mitochondria to eliminate excessive ROS. In vitro study suggested Atv/PTP-TCeria NPs exhibited superior antioxidant and anti-apoptotic activity. In vivo study showed that Atv/PTP-TCeria NPs effectively decreased oxidative stress and inflammatory, could protect the mitochondrial structure, reduced apoptosis of tubular cell and tubular necrosis in the sepsis-induced AKI mice model. Conclusions: This ROS-responsive nano-drug delivery system combining mitochondria-targeting ceria nanoparticles with atorvastatin has favorable potentials in the sepsis-induced AKI therapy.