A Self-Healing Optoacoustic Patch with High Damage Threshold and Conversion Efficiency for Biomedical Applications

Compared with traditional piezoelectric ultrasonic devices,optoacoustic devices have unique advantages such as a simple preparation process,anti-electromagnetic interference,and wireless long-distance power supply.However,current optoacoustic devices remain limited due to a low damage threshold and energy conversion efficiency,which seriously hinder their widespread applications.In this study,using a self-healing polydimethylsiloxane(PDMS,Fe-Hpdca-PDMS)and carbon nanotube composite,a flexible optoacoustic patch is developed,which possesses the self-healing capability at room temperature,and can even recover from damage induced by cutting or laser irradiation.Moreover,this patch can generate high-intensity ultrasound(>25 MPa)without the focusing structure.The laser damage threshold is greater than 183.44 mJ cm^(-2),and the optoacoustic energy conversion efficiency reaches a major achievement at 10.66×10^(-3),compared with other carbon-based nanomaterials and PDMS composites.This patch is also been successfully examined in the application of acoustic flow,thrombolysis,and wireless energy harvesting.All findings in this study provides new insight into designing and fabricating of novel ultrasound devices for biomedical applications.

KRAS Exon 3 and PTEN Exon 7 Mutations in Small-cell Lung Cancer

Small cell lung cancer (SCLC) is recognized as one of the most aggressive and fatal malignant tumors. No significant improvement has been made to prolong the survival of SCLC patients. This study aimed to examine the mutation status of K-Ras (KRAS) and phosphatase and tensin homolog (PTEN) in SCLC patients in order to identify potential therapeutic targets for SCLC. Nineteen primary SCLC tumor specimens were enrolled in the study. Direct sequencing was perfonned to detect the mutations of KRAS exon 3 and PTEN exon 7 in the specimens. Kaplan- Meier and Cox regression analysis was performed to determine the overall survival (OS) of these SCLC patients. KRAS exon 3 mutation was found in 4 (21%) SCLC patients, and PTEN exon 7 mutation in only 1 (5%) SCLC patient. Kaplan Meier analysis showed that clinical stage and brain metastasis were significantly associated with OS (both P<0.05), but neither KRAS exon 3 mutation nor PTEN exon 7 mutation was significantly associated with OS (P>0.05). Cox proportional hazards regression model indicated that extensive stage of disease was the only independent negative prognostic factor for OS in SCLC patients. In conclusion, KRAS exon 3 and PTEN exon 7 mutations had no significant impact on OS of SCLC patients. Further study is still necessary to validate the molecular profiles of SCLC.

Visible light responsive spiropyran derivatives based on dynamic coordination bonds

Spiropyrans(SPs) are a well-known class of photochromic compounds and have found widespread application due to their unique properties. However, for many conventional SPs, high energy ultraviolet(UV)light is commonly essential to drive photoisomerization, leading to poor fatigue resistance. Moreover, the practical application of spiropyrans is hindered by their fast fading speed due to the instability of closed forms(SP) or open forms(MC). Herein, we disclose a novel strategy to address these challenges through introducing both electron-donating substituents to stabilize the SP and dynamic coordination bonds to stabilize the MC. The resulting new spiropyrans complexes exhibit negative photochromic properties, with fast visible light response, good stability of both SP and MC, and significantly improved fatigue resistance.

In vivo field recordings effectively monitor the mouse cortex and hippocampus under isoflurane anesthesia

Isoflurane is a widely used inhaled anesthetic in the clinical setting. However, the mechanism underlying its effect on consciousness is under discussion. Therefore, we investigated the effect of isoflurane on the hippocampus and cortex using an in vivo field recording approach. Our results showed that 1.3%, 0.8%, and 0.4% isoflurane exerted an inhibitory influence on the mouse hippocampus and cortex. Further, high frequency bands in the cortex and hippocampus showed greater suppression with increasing isoflurane concentration. Our findings suggest that in vivo field recordings can monitor the effect of isoflurane anesthesia on the mouse cortex and hippocampus.

A Fast and Room-temperature Self-healing Thermal Conductive Polymer Composite

Thermal conducting materials may be damaged during long-term use,resulting in the increase of thermal resistance and therefore inefficient heat dissipation.The introduction of self-healing ability may solve this problem,but the realization of fast and room-temperature self-healing in thermal conducting composites is quite challenging.Herein,we choose a flexible poly(dimethylsiloxane)polymer material(PDMS-COOH)as the matrix and graphene nanosheets as the thermal conductive filler to prepare a new kind of thermal conductive polymer composite(PDMS-COOH-CG)that can quickly self-heal at room temperature.The thermal conductivity of PDMS-COOH-CG10 with 10%of graphene content is 0.48 W·m^(-1)·K^(-1),which is 16 times that of PDMS-COOH(0.03 W·m^(-1)·K^(-1)).At room temperature,self-healing efficiency of PDMS-COOH-CG10 based on tensile strength can be 53.8%for 30 s and 84.6%for 24 h.Dynamic infrared thermal imaging dipicted that after 2 min of self-healing at room temperature,the thermal conduction temperature near the damage was basically restored to the level of the pristine sample.

Efficient circularly polarized photoluminescence and electroluminescence of chiral spiro-skeleton-based thermally activated delayed fluorescence molecules

Chiral thermally activated delayed fluorescence(TADF) molecules showing circularly polarized luminescence(CPL) have great potential in 3D displays. However, the relationships among CPL property, device performance and molecule structure are still not clear. In this article, we develop a strategy to promote dissymmetry factors without sacrifice in device performance and study the impact of molecule structures towards CPL property. Three novel TADF enantiomers are synthesized and studied.(R/S)-SCN with diminutive cyano group as an acceptor shows dissymmetry factor |gPL| ≈ 1.4×10^(-3) and noticeable organic light-emitting diode(OLED) performances with a maximum external quantum efficiency(EQEmax) of 23.0%. For(R/S)-SPHCN, the prolonged electron withdrawing group benzonitrile enhances |gPL| up to 3.6×10^(-3) with decreased device EQEmaxof 15.4%. By further replacing benzonitrile with(trifluoromethyl)pyridine, the enantiomers of(R/S)-SCFPY show similar |gPL| factors of 3.5×10^(-3) and device EQE_(max)up to 23.3%, which represents the highest efficiency among sprio-type TADF materials based OLEDs. Furthermore, the OLEDs also show obvious circularly polarized electroluminescence with gELfactors of-1.4/1.8×10^(-3),-3.6/3.6×10^(-3) and-3.7/3.6×10^(-3), respectively. These results indecate by delicate functional group engineering, high g factor can be achieved while maintaining decent device performances. Besides,(R/S)-SCFPY represents an impressive TADF emitter, which shows promoted g factor and recorded high device EQE_(max)among similar molecules.

Stretchable and self-healable spoof plasmonic meta-waveguide for wearable wireless communication system

Microwave transmission lines in wearable systems are easily damaged after frequent mechanical deformation,posing a severe threat to wireless communication.Here,we report a new strategy to achieve stretchable microwave transmission lines with superior reliability and durability by integrating a self-healable elastomer with serpentine-geometry plasmonic meta-waveguide to support the spoof surface plasmon polariton(SSPP).After mechanical damage,the self-healable elastomer can autonomously repair itself to maintain the electromagnetic performance and mechanical strength.Meanwhile,the specially designed SSPP structure exhibits excellent stability and damage resistance.Even if the self-healing process has not been completed or the eventual repair effect is not ideal,the spoof plasmonic meta-waveguide Can still maintain reliable performance.Self-healing material enhances strength and durability,while the SSPP improves stability and gives more tolerance to the self-healing process.Our design coordinates the structural design with material synthesis to maximize the advantages of the SSPP and self-healing material,signifcantly improving the relability and durability of stretchable microwave transmission lines.We also perform communication quality experiments to demonstrate the potential of the proposed meta-waveguide as interconnects in future body area network systems.

A Strong and Rigid Coordination Adaptable Network that Can Be Reprocessed and Recycled at Mild Conditions

The investigation of covalent adaptable networks(CANs)is expanding rapidly due to the growing demand for sustainable materials,as CANs show thermoset-like behavior and yet can be reprocessed,recycled,and healed.However,most of the CANs reported so far have a trade-off between mechanical strength and reversible properties and often show performance reduction after reprocessing and/or recycling.Herein,we designed and synthesized a coordination adaptable network(CoAN)by crosslinking low-molecular-weight monomers with abundant coordination bonds.Owning to its excellent variable-stiffness property,leading to high stiffness at ambient conditions and low viscosity at elevated temperature,the as-prepared CoAN showed high mechanical rigidity but could be reprocessed rapidly and recycled at mild conditions.After reprocessing or recycling,the mechanical properties of the samples showed no performance reduction,compared with a pristine sample.Density functional theory calculations showed that free thiol ligands played a key role in reducing the activation energy for bond exchange.When used as binders for composites,the embedded carbon fibers could be recycled rapidly and still maintain the original microstructure.The material also showed temperature-sensitive dielectric and conductive properties due to the release of metal ions upon heating.Overall,such performances are superior among the CANs reported previously.