Engineering exosomes from fibroblast growth factor 1 pre-conditioned adipose-derived stem cells promote ischemic skin flaps survival by activating autophagy.

Background: The recovery of ischemic skin flaps is a major concern in clinical settings. The purpose of this study is to evaluate the effects of engineered exosomes derived from FGF1 pre-conditioned adipose-derived stem cells (FEXO) on ischemic skin flaps.

Method: 6 patients who suffered from pressure ulcer at stage 4 and underwent skin flaps surgery were recruited in this study to screen the potential targets of ischemic skin flaps in FGF family.

Acid Neutralization by Composite Lysine Nanoparticles for Spinal Cord Injury Recovery through Mitigating Mitochondrial Dysfunction.

After spinal cord injury (SCI), significant alterations in the tissue microenvironment lead to mitochondrial dysfunction, inducing apoptosis and inhibiting the remodeling of neural circuits, thereby impeding recovery. Although previous studies have demonstrated a marked decrease in pH at the injury site, creating an acidic microenvironment, the impact of improving this acidic microenvironment on SCI recovery has not been investigated. This study prepared a lysine@hollow mesoporous silica nanoparticle/gelatin methacrylate (GelMA) (L@H/G) composite hydrogel.

Comparison of left atrial and left atrial appendage mechanics in the recurrence of atrial fibrillation after radiofrequency catheter ablation.

Objectives: Although radiofrequency catheter ablation (RFCA) has become an important treatment strategy for paroxysmal or persistent atrial fibrillation (AF), AF recurrence after RFCA remains an important issue that plagues clinicians and patients. This study aimed to investigate the association of left atrial (LA) and left atrial appendage (LAA) mechanics with AF recurrence after RFCA and to compare their prognostic values in patients with AF undergoing RFCA.

Methods: A total of 160 patients with non-valvular AF who underwent RFCA for the first time were included in this study.

Cadmium-induced preeclampsia-like phenotype in the rat is related to decreased progesterone synthesis in the placenta.

Cadmium (Cd) is a toxic element, which is associated with preeclampsia (PE).We treated pregnant rats with cadmium chloride from gestational days (GDs) 9-12 to introduce the PE-like animal model. Maternal systolic blood pressures (SBPs) and body weights were measured on GDs 0, 5, 10, 15, and 20.

Monolithic mtesla-level magnetic induction by self-rolled-up membrane technology.

Monolithic strong magnetic induction at the mtesla to tesla level provides essential functionalities to physical, chemical, and medical systems. Current design options are constrained by existing capabilities in three-dimensional (3D) structure construction, current handling, and magnetic material integration. We report here geometric transformation of large-area and relatively thick (~100 to 250 nm) 2D nanomembranes into multiturn 3D air-core microtubes by a vapor-phase self-rolled-up membrane (S-RuM) nanotechnology, combined with postrolling integration of ferrofluid magnetic materials by capillary force.

Localized Triggering of the Insulator-Metal Transition in VO Using a Single Carbon Nanotube.

Vanadium dioxide (VO) has been widely studied for its rich physics and potential applications, undergoing a prominent insulator-metal transition (IMT) near room temperature. The transition mechanism remains highly debated, and little is known about the IMT at nanoscale dimensions. To shed light on this problem, here we use ∼1 nm-wide carbon nanotube (CNT) heaters to trigger the IMT in VO.

Quasi-Ballistic Thermal Transport Across MoS Thin Films.

Layered two-dimensional (2D) materials have highly anisotropic thermal properties between the in-plane and cross-plane directions. Conventionally, it is thought that cross-plane thermal conductivities (κ ) are low, and therefore c-axis phonon mean free paths (MFPs) are small. Here, we measure κ across MoS films of varying thickness (20-240 nm) and uncover evidence of very long c-axis phonon MFPs at room temperature in these layered semiconductors.

Microstructural origin of resistance-strain hysteresis in carbon nanotube thin film conductors.

A basic need in stretchable electronics for wearable and biomedical technologies is conductors that maintain adequate conductivity under large deformation. This challenge can be met by a network of one-dimensional (1D) conductors, such as carbon nanotubes (CNTs) or silver nanowires, as a thin film on top of a stretchable substrate. The electrical resistance of CNT thin films exhibits a hysteretic dependence on strain under cyclic loading, although the microstructural origin of this strain dependence remains unclear.

Spatially Resolved Thermometry of Resistive Memory Devices.

The operation of resistive and phase-change memory (RRAM and PCM) is controlled by highly localized self-heating effects, yet detailed studies of their temperature are rare due to challenges of nanoscale thermometry. Here we show that the combination of Raman thermometry and scanning thermal microscopy (SThM) can enable such measurements with high spatial resolution. We report temperature-dependent Raman spectra of HfO, TiO and GeSbTe (GST) films, and demonstrate direct measurements of temperature profiles in lateral PCM devices.

Dense Vertically Aligned Copper Nanowire Composites as High Performance Thermal Interface Materials.

Thermal interface materials (TIMs) are essential for managing heat in modern electronics, and nanocomposite TIMs can offer critical improvements. Here, we demonstrate thermally conductive, mechanically compliant TIMs based on dense, vertically aligned copper nanowires (CuNWs) embedded into polymer matrices. We evaluate the thermal and mechanical characteristics of 20-25% dense CuNW arrays with and without polydimethylsiloxane infiltration.

Solution-mediated selective nanosoldering of carbon nanotube junctions for improved device performance.

As-grown randomly aligned networks of carbon nanotubes (CNTs) invariably suffer from limited transport properties due to high resistance at the crossed junctions between CNTs. In this work, Joule heating of the highly resistive CNT junctions is carried out in the presence of a spin-coated layer of a suitable chemical precursor. The heating triggers thermal decomposition of the chemical precursor, tris(dibenzylideneacetone)dipalladium (Pd2(dba)3), and causes local deposition of Pd nanoparticles at the CNT junctions, thereby improving the on/off current ratio and mobility of CNT network devices by an average factor of ∼6.

Helical carbon nanotubes enhance the early immune response and inhibit macrophage-mediated phagocytosis of Pseudomonas aeruginosa.

Aerosolized or aspirated manufactured carbon nanotubes have been shown to be cytotoxic, cause pulmonary lesions, and demonstrate immunomodulatory properties. CD-1 mice were used to assess pulmonary toxicity of helical carbon nanotubes (HCNTs) and alterations of the immune response to subsequent infection by Pseudomonas aeruginosa in mice. HCNTs provoked a mild inflammatory response following either a single exposure or 2X/week for three weeks (multiple exposures) but were not significantly toxic.

High field breakdown characteristics of carbon nanotube thin film transistors.

The high field properties of carbon nanotube (CNT) network thin film transistors (CN-TFTs) are important for their practical operation, and for understanding their reliability. Using a combination of experimental and computational techniques we show how the channel geometry (length L(C) and width W(C)) and network morphology (average CNT length L(t) and alignment angle distribution θ) affect heat dissipation and high field breakdown in such devices. The results suggest that when WC ≥ L(t), the breakdown voltage remains independent of W(C) but varies linearly with L(C).

High-field transport and thermal reliability of sorted carbon nanotube network devices.

We examine the high-field operation, power dissipation, and thermal reliability of sorted carbon nanotube network (CNN) devices, with <1% to >99% semiconducting nanotubes. We combine systematic electrical measurements with infrared (IR) thermal imaging and detailed Monte Carlo simulations to study high-field transport up to CNN failure by unzipping-like breakdown. We find that metallic CNNs carry peak current densities up to an order of magnitude greater than semiconducting CNNs at comparable nanotube densities.

Nanoscale Joule heating, Peltier cooling and current crowding at graphene-metal contacts.

The performance and scaling of graphene-based electronics is limited by the quality of contacts between the graphene and metal electrodes. However, the nature of graphene-metal contacts remains incompletely understood. Here, we use atomic force microscopy to measure the temperature distributions at the contacts of working graphene transistors with a spatial resolution of ~ 10 nm (refs 5-8), allowing us to identify the presence of Joule heating, current crowding and thermoelectric heating and cooling.