A novel approach for using conjugated rod–coil materials as a floating gate in the fabrication of nonvolatile photonic transistor memory devices, consisting of n‐type Sol‐PDI and p‐type C10‐DNTT, is ...presented. Sol‐PDI and C10‐DNTT are used as dual functions of charge‐trapping (conjugated rod) and tunneling (insulating coil), while n‐type BPE‐PDI and p‐type DNTT are employed as the corresponding transporting layers. By using the same conjugated rod in the memory layer and transporting channel with a self‐assembled structure, both n‐type and p‐type memory devices exhibit a fast response, a high current contrast between “Photo‐On” and “Electrical‐Off” bistable states over 105, and an extremely low programing driving force of 0.1 V. The fabricated photon‐driven memory devices exhibit a quick response to different wavelengths of light and a broadband light response that highlight their promising potential for light‐recorder and synaptic device applications.
High‐performance photonic transistor memory devices are fabricated using conjugated rod–coil materials as a photoactive floating gate, in which the conjugated rods and side‐chain coils act as charge‐trapping and tunneling moieties, respectively. By inheriting their self‐assembled structure, both n‐type and p‐type memory devices exhibit a fast response, a current contrast over 105, and an extremely low programing driving force of 0.1 V.
Mechanical failure of π‐conjugated polymer thin films is unavoidable under cyclic loading conditions, due to intrinsic defects and poor resistance to crack propagation. Here, the first tear‐resistant ...and room‐temperature self‐healable semiconducting composite is presented, consisting of conjugated polymers and butyl rubber elastomers. This new composite displays both a record‐low elastic modulus (<1 MPa) and ultrahigh deformability with fracture strain above 800%. More importantly, failure behavior is not sensitive to precut notches under deformation. Autonomous self‐healing at room temperature, both mechanical and electronic, is demonstrated through the physical contact of two separate films. The composite film also shows device stability in the ambient environment over 5 months due to much‐improved barrier property to both oxygen and water. Butyl rubber is broadly applicable to various p‐type and n‐type semiconducting polymers for fabricating self‐healable electronics to provide new resilient electronics that mimic the tear resistance and healable property of human skin.
A mechanically durable and electronically stable semiconducting composite is engineered by introducing a blend of donor–acceptor polymer and butyl rubber elastomer. The composite exhibits ultralow modulus, ultrahigh deformability, tear resistance, and self‐healing performance, as well as ambient stable device stability. This method is widely applicable to different semiconducting polymers.
It is discovered that the memory‐type behaviors of novel carbohydrate‐block‐polyisoprene (MH‐b‐PI) block copolymers‐based devices, including write‐once‐read‐many‐times, Flash, and ...dynamic‐random‐access‐memory, can be easily controlled by the self‐assembly nanostructures (vertical cylinder, horizontal cylinder, and order‐packed sphere), in which the MH and PI blocks, respectively, provide the charge‐trapping and stretchable function. With increasing the flexible PI block length, the stretchability of the designed copolymers can be significantly improved up to 100% without forming cracks. Thus, intrinsically stretchable resistive memory devices (polydimethylsiloxane(PDMS)/carbon nanotubes(CNTs)/MH‐b‐PI thin film/Al) using the MH‐b‐PI thin film as an active layer is successfully fabricated and that using the MH‐b‐PI12.6k under 100% strain exhibits an excellent ON/OFF current ratio of over 106 (reading at −1 V) with stable V
set around −2 V. Furthermore, the endurance characteristics can be maintained over 500 cycles upon 40% strain. This work establishes and represents a novel avenue for the design of green carbohydrate‐derived and stretchable memory materials.
Novel stretchable block copolymers, carbohydrate‐block‐polyisoprene (MH‐b‐PI), designed for developing fully stretchable resistive memory, are demonstrated. Diverse self‐assembly nanostructures with respect to the ratio of charge‐trapping MH to stretchable PI can exhibit different memory behaviors. The polymer with longer PI, MH‐b‐PI12.6k, shows an excellent ON/OFF ratio of over 106 upon 100% stretching and the endurance characteristics can be maintained over 500 cycles.
2D transition metal dichalcogenide (TMD) layered materials are promising for future electronic and optoelectronic applications. The realization of large‐area electronics and circuits strongly relies ...on wafer‐scale, selective growth of quality 2D TMDs. Here, a scalable method, namely, metal‐guided selective growth (MGSG), is reported. The success of control over the transition‐metal‐precursor vapor pressure, the first concurrent growth of two dissimilar monolayer TMDs, is demonstrated in conjunction with lateral or vertical TMD heterojunctions at precisely desired locations over the entire wafer in a single chemical vapor deposition (VCD) process. Owing to the location selectivity, MGSG allows the growth of p‐ and n‐type TMDs with spatial homogeneity and uniform electrical performance for circuit applications. As a demonstration, the first bottom‐up complementary metal‐oxide‐semiconductor inverter based on p‐type WSe2 and n‐type MoSe2 is achieved, which exhibits a high and reproducible voltage gain of 23 with little dependence on position.
Dissimilar transition metal dichalcogenides (TMDs) are grown concurrently and location‐selectively by a new method. Precise control over the transition‐metal‐precursor vapor pressure allows successful lateral and vertical heterojunction growth, as well as growth of p‐ and n‐type TMDs at desired locations. A new synthetic strategy for future (opto)electronic applications is thus provided.
The endoplasmic reticulum (ER) has diverse functions, and especially misfolded protein modification is in the focus of this review paper. With a highly regulatory mechanism, called unfolded protein ...response (UPR), it protects cells from the accumulation of misfolded proteins. Nevertheless, not only does UPR modify improper proteins, but it also degrades proteins that are unable to recover. Three pathways of UPR, namely PERK, IRE-1, and ATF6, have a significant role in regulating stress-induced physiological responses in cells. The dysregulated UPR may be involved in diseases, such as atherosclerosis, heart diseases, amyotrophic lateral sclerosis (ALS), and cancer. Here, we discuss the relation between UPR and cancer, considering several aspects including survival, dormancy, immunosuppression, angiogenesis, and metastasis of cancer cells. Although several moderate adversities can subject cancer cells to a hostile environment, UPR can ensure their survival. Excessive unfavorable conditions, such as overloading with misfolded proteins and nutrient deprivation, tend to trigger cancer cell death signaling. Regarding dormancy and immunosuppression, cancer cells can survive chemotherapies and acquire drug resistance through dormancy and immunosuppression. Cancer cells can also regulate the downstream of UPR to modulate angiogenesis and promote metastasis. In the end, regulating UPR through different molecular mechanisms may provide promising anticancer treatment options by suppressing cancer proliferation and progression.
Although low-density culture provides an efficient method for rapid expansion of human mesenchymal stem cells (MSCs), MSCs enriched by this method undergo senescence and lose their stem cell ...properties, which could be preserved by combining low-density and hypoxic culture. The mechanism was mediated through direct down-regulation of E2A-p21 by the hypoxia-inducible factor–1α (HIF-1α)–TWIST axis. Expansion under normoxia induced E2A and p21 expression, which were abrogated by overexpression of TWIST, whereas siRNA against TWIST up-regulated E2A and p21 in hypoxic cells. Furthermore, siRNA against p21 in normoxic cells enhanced proliferation and increased differentiation potential, whereas overexpression of p21 in hypoxic cells induced a decrease in proliferation and a loss of differentiation capacity. More importantly, MSCs expanded under hypoxic conditions by up to 100 population doublings, exhibited telomerase activity with maintained telomere length, normal karyotyping, and intact genetic integrity, and did not form tumors. These results support low-density hypoxic culture as a method for efficiently expanding MSCs without losing stem cell properties or increasing tumorigenicity.
Organic–inorganic hybrid perovskites have garnered significant attention in optoelectronics owing to their outstanding tunable optical characteristics. Controlled growth of perovskite nanocrystals ...from solutions is key for controlling the emission intensity and photoluminescence lifetime of perovskites. In particular, most studies have focused on controlling the crystallization of perovskite through chemical treatment using chelating ligands or physical treatment via antisolvent diffusion, and there exists a trade‐off between the photoluminescence intensity and lifetime of perovskites. Herein, a selective solvent vapor‐assisted crystallization with the aid of a functional polymer, which nanoscale perovskite crystals are grown andante from precursor solution, is presented for tuning the crystallization and optical properties of a common halide perovskite, methylammonium lead bromide (MAPbBr3). The proposed method here produces perovskite nanocrystals in the range of 200–300 nm. The spin‐coated thin film formed from the perovskite solution exhibits strong green photoluminescence with a long lifetime. The effects of the functional group and polymer dosage on the crystallization of MAPbBr3 are systematically investigated, and the crystallization mechanism is explained based on a modified LaMer model. This study provides an advanced solution process for precisely controlling perovskite crystallization to enhance their optical properties for next‐generation optoelectronic devices.
The proposed unconventional solvent vapor‐assisted crystallization method enables growth rate of organic–inorganic hybrid perovskite crystals in better controlled manner. Together with an additive of the metal‐coordinating functional polymer, i.e., polyvinylpyrrolidone, the resultant perovskite crystals exhibit an exquisite optical property with strong green emission and long lifetime carriers.
Members of the Ras superfamily have been found to perform several functions leading to the development of eukaryotes. These small GTPases are divided into five major subfamilies, and their regulators ...can "turn on" and "turn off" signals. Recent studies have shown that this superfamily of proteins has various roles in the process of vascular development, such as vasculogenesis and angiogenesis. Here, we discuss the role of these subfamilies in the development of the vascular system in zebrafish.
Immunotherapy has emerged as a promising approach for cancer treatment, and the use of microRNAs (miRNAs) as therapeutic agents has gained significant attention. In this study, we investigated the ...effectiveness of immunotherapy utilizing miRNA34a and Jurkat T cells in inducing cell death in non-small-cell lung cancer cells, specifically A549 cells. Moreover, we explored the impact of Jurkat T cell activation and miRNA34a delivery using iron oxide nanorods (IONRs) on the killing of cancer cells. A549 cells were cocultured with both activated and inactivated Jurkat T cells, both before and after the delivery of miRNA34a. Surprisingly, our results revealed that even inactive Jurkat T cells were capable of inducing cell death in cancer cells. This unexpected observation suggested the presence of alternative mechanisms by which Jurkat T cells can exert cytotoxic effects on cancer cells. We stimulated Jurkat T cells using anti-CD3/CD28 and analyzed their efficacy in killing A549 compared to that of the inactive Jurkat T cells in conjunction with miRNA34a. Our findings indicated that the activation of Jurkat T cells significantly enhanced their cytotoxic potential against cancer cells compared to their inactive counterparts. The combined treatment of A549 cells with activated Jurkat T cells and miRNA34a demonstrated the highest level of cancer cell death, suggesting a synergistic effect between Jurkat T cell activation and miRNA therapy. Besides the apoptosis mechanism for the Jurkat T cells’ cytotoxic effects on A549 cells, we furthermore investigated the ferroptosis pathway, which was found to have an impact on the cancer cell killing due to the presence of miRNA34a and IONRs as the delivery agent inside the cancer cells.
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