A Highly Conductive n-Type Conjugated Polymer Synthesized in Water.

Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) is a benchmark hole-transporting (p-type) polymer that finds applications in diverse electronic devices. Most of its success is due to its facile synthesis in water, exceptional processability from aqueous solutions, and outstanding electrical performance in ambient. Applications in fields like (opto-)electronics, bioelectronics, and energy harvesting/storage devices often necessitate the complementary use of both p-type and n-type (electron-transporting) materials. However, the availability of n-type materials amenable to water-based polymerization and processing remains limited. Herein, we present a novel synthesis method enabling direct polymerization in water, yielding a highly conductive, water-processable n-type conjugated polymer, namely, poly[(2,2'-(2,5-dihydroxy-1,4-phenylene)diacetic acid)-stat-3,7-dihydrobenzo[1,2-b:4,5-b']difuran-2,6-dione] (PDADF), with remarkable electrical conductivity as high as 66 S cm-1, ranking among the highest for n-type polymers processed using green solvents. The new n-type polymer PDADF also exhibits outstanding stability, maintaining 90% of its initial conductivity after 146 days of storage in air. Our synthetic approach, along with the novel polymer it yields, promises significant advancements for the sustainable development of organic electronic materials and devices.

Lipopolysaccharide binding protein resists hepatic oxidative stress by regulating lipid droplet homeostasis.

Oxidative stress-induced lipid accumulation is mediated by lipid droplets (LDs) homeostasis, which sequester vulnerable unsaturated triglycerides into LDs to prevent further peroxidation. Here we identify the upregulation of lipopolysaccharide-binding protein (LBP) and its trafficking through LDs as a mechanism for modulating LD homeostasis in response to oxidative stress. Our results suggest that LBP induces lipid accumulation by controlling lipid-redox homeostasis through its lipid-capture activity, sorting unsaturated triglycerides into LDs. N-acetyl-L-cysteine treatment reduces LBP-mediated triglycerides accumulation by phospholipid/triglycerides competition and Peroxiredoxin 4, a redox state sensor of LBP that regulates the shuttle of LBP from LDs. Furthermore, chronic stress upregulates LBP expression, leading to insulin resistance and obesity. Our findings contribute to the understanding of the role of LBP in regulating LD homeostasis and against cellular peroxidative injury. These insights could inform the development of redox-based therapies for alleviating oxidative stress-induced metabolic dysfunction.

Switchable Broadband Terahertz Absorbers Based on Conducting Polymer-Cellulose Aerogels.

Terahertz (THz) technologies provide opportunities ranging from calibration targets for satellites and telescopes to communication devices and biomedical imaging systems. A main component will be broadband THz absorbers with switchability. However, optically switchable materials in THz are scarce and their modulation is mostly available at narrow bandwidths. Realizing materials with large and broadband modulation in absorption or transmission forms a critical challenge. This study demonstrates that conducting polymer-cellulose aerogels can provide modulation of broadband THz light with large modulation range from ≈ 13% to 91% absolute transmission, while maintaining specular reflection loss < -30 dB. The exceptional THz modulation is associated with the anomalous optical conductivity peak of conducting polymers, which enhances the absorption in its oxidized state. The study also demonstrates the possibility to reduce the surface hydrophilicity by simple chemical modifications, and shows that broadband absorption of the aerogels at optical frequencies enables de-frosting by solar-induced heating. These low-cost, aqueous solution-processable, sustainable, and bio-friendly aerogels may find use in next-generation intelligent THz devices.

Industrial Kraft Lignin Based Binary Cathode Interface Layer Enables Enhanced Stability in High Efficiency Organic Solar Cells.

Herein, a binary cathode interface layer (CIL) strategy based on the industrial solvent fractionated LignoBoost kraft lignin (KL) is adopted for fabrication of organic solar cells (OSCs). The uniformly distributed phenol moieties in KL enable it to easily form hydrogen bonds with commonly used CIL materials, i.e., bathocuproine (BCP) and PFN-Br, resulting in binary CILs with tunable work function (WF). This work shows that the binary CILs work well in OSCs with large KL ratio compatibility, exhibiting equivalent or even higher efficiency to the traditional CILs in state of art OSCs. In addition, the combination of KL and BCP significantly enhanced OSC stability, owing to KL blocking the reaction between BCP and nonfullerene acceptors (NFAs). This work provides a simple and effective way to achieve high-efficient OSCs with better stability and sustainability by using wood-based materials.

Ground-state electron transfer in all-polymer donor:acceptor blends enables aqueous processing of water-insoluble conjugated polymers.

Water-based conductive inks are vital for the sustainable manufacturing and widespread adoption of organic electronic devices. Traditional methods to produce waterborne conductive polymers involve modifying their backbone with hydrophilic side chains or using surfactants to form and stabilize aqueous nanoparticle dispersions. However, these chemical approaches are not always feasible and can lead to poor material/device performance. Here, we demonstrate that ground-state electron transfer (GSET) between donor and acceptor polymers allows the processing of water-insoluble polymers from water. This approach enables macromolecular charge-transfer salts with 10,000× higher electrical conductivities than pristine polymers, low work function, and excellent thermal/solvent stability. These waterborne conductive films have technological implications for realizing high-performance organic solar cells, with efficiency and stability superior to conventional metal oxide electron transport layers, and organic electrochemical neurons with biorealistic firing frequency. Our findings demonstrate that GSET offers a promising avenue to develop water-based conductive inks for various applications in organic electronics.

Cellulose-Based Radiative Cooling and Solar Heating Powers Ionic Thermoelectrics.

Cellulose opens for sustainable materials suitable for radiative cooling thanks to inherent high thermal emissivity combined with low solar absorptance. When desired, solar absorptance can be introduced by additives such as carbon black. However, such materials still shows high thermal emissivity and therefore performs radiative cooling that counteracts the heating process if exposed to the sky. Here, this is addressed by a cellulose-carbon black composite with low mid-infrared (MIR) emissivity and corresponding suppressed radiative cooling thanks to a transparent IR-reflecting indium tin oxide coating. The resulting solar heater provides opposite optical properties in both the solar and thermal ranges compared to the cooler material in the form of solar-reflecting electrospun cellulose. Owing to these differences, exposing the two materials to the sky generated spontaneous temperature differences, as used to power an ionic thermoelectric device in both daytime and nighttime. The study characterizes these effects in detail using solar and sky simulators and through outdoor measurements. Using the concept to power ionic thermoelectric devices shows thermovoltages of >60 mV and 10 °C temperature differences already at moderate solar irradiance of ≈400 W m-2 .

High-performance blood plasma separation based on a Janus membrane technique and RBC agglutination reaction.

Separation of plasma which is full of various biomarkers is critical for clinical diagnosis. However, the point-of-care plasma separation often relies on microfluidic filtration membranes which are usually limited in purity, yield, hemolysis, extraction speed, hematocrit level, and protein recovery. Here, we have developed a high-performance plasma membrane separation technique based on a Janus membrane and red blood cell (RBC) agglutination reaction. The RBC agglutination reaction can form larger RBC aggregates to separate plasma from blood cells. Then, the Janus membrane, serving as a multipore microfilter to block large RBC aggregates, allows the plasma to flow from the hydrophobic side to its hydrophilic side spontaneously. As a result, the separation technique can extract highly-purified plasma (99.99%) from whole blood with an ultra-high plasma yield (∼80%) in ∼80 s. Additionally, the separation technique is independent of the hematocrit level and can avoid hemolysis.

Uptake and transport of antibiotic kasugamycin in castor bean (Ricinus communis L.) seedlings.

Kasugamycin (KSM), an aminoglycoside antibiotic, has been widely used for the management of plant diseases, especially for the control of rice blast in Asia. However, its uptake mechanism and transport in plants are still obscure. The castor bean (Ricinus communis L.) seeding, a model plant for phloem transport, was used to study the mechanism of uptake and transport of KSM. Results showed that cotyledon-applied KSM could transport into the phloem and distributed in root and shoot of plant. The temperature, concentration, and pH had significant effects on the uptake of KSM, indicating that the uptake of KSM was mediated by an active carrier system. Compared with the control, competitive inhibitors of sugar transporters D-glucose, D-chiro-inositol, and phloridzin inhibited 71.03%, 67.95%, and 61.73% uptake of KSM, respectively. Energy inhibitor dinitrophenol (DNP) and carbonyl cyanide chlorophenylhydrazone (CCCP) also affected the uptake of KSM, and the inhibition rates were 34.23% and 48.06%. All the results showed that the uptake of KSM was mediated by a sugar transporter, and it could transport from shoot to root in plants via the phloem. The study preliminary elucidated the plant-microbe interactions in the context of the transport of microbial secondary metabolites in plants. It has certain significance for scientific application of antibiotics and biological control of plant diseases and provides theoretical basis for the development of bidirectional transport pesticides.

Knockdown of Acid-sensing Ion Channel 1a in the PVN Promotes Metabolic Disturbances in Male Mice.

Increasing incidence of metabolic disturbances has become a severe public healthcare problem. Ion channels and receptors in the paraventricular nucleus (PVN) of the hypothalamus serve vital roles in modulating neuronal activities and endocrine functions, which are linked to the regulation of energy balance and glucose metabolism. In this study, we found that acid-sensing ion channel 1a (ASIC1a), a Ca2+-permeable cationic ion channel was localized in the PVN. Knockdown of ASIC1a in this region led to significant body weight gain, glucose intolerance, and insulin resistance. Pharmacological inhibition of ASIC1a resulted in an increase in food intake and a decrease in energy expenditure. Our findings suggest ASIC1a in the PVN as a potential new target for the therapeutic intervention of metabolic disorders.

Mapping the energy level alignment at donor/acceptor interfaces in non-fullerene organic solar cells.

Energy level alignment (ELA) at donor (D) -acceptor (A) heterojunctions is essential for understanding the charge generation and recombination process in organic photovoltaic devices. However, the ELA at the D-A interfaces is largely underdetermined, resulting in debates on the fundamental operating mechanisms of high-efficiency non-fullerene organic solar cells. Here, we systematically investigate ELA and its depth-dependent variation of a range of donor/non-fullerene-acceptor interfaces by fabricating and characterizing D-A quasi bilayers and planar bilayers. In contrast to previous assumptions, we observe significant vacuum level (VL) shifts existing at the D-A interfaces, which are demonstrated to be abrupt, extending over only 1-2 layers at the heterojunctions, and are attributed to interface dipoles induced by D-A electrostatic potential differences. The VL shifts result in reduced interfacial energetic offsets and increased charge transfer (CT) state energies which reconcile the conflicting observations of large energy level offsets inferred from neat films and large CT energies of donor - non-fullerene-acceptor systems.

Cavitation Fibrillation of Cellulose Fiber.

Cellulose fibrils are the structural backbone of plants and, if carefully liberated from biomass, a promising building block for a bio-based society. The mechanism of the mechanical release─fibrillation─is not yet understood, which hinders efficient production with the required reliable quality. One promising process for fine fibrillation and total fibrillation of cellulose is cavitation. In this study, we investigate the cavitation treatment of dissolving, enzymatically pretreated, and derivatized (TEMPO oxidized and carboxymethylated) cellulose fiber pulp by hydrodynamic and acoustic (i.e., sonication) cavitation. The derivatized fibers exhibited significant damage from the cavitation treatment, and sonication efficiently fibrillated the fibers into nanocellulose with an elementary fibril thickness. The breakage of cellulose fibers and fibrils depends on the number of cavitation treatment events. In assessing the damage to the fiber, we presume that microstreaming in the vicinity of imploding cavities breaks the fiber into fibrils, most likely by bending. A simple model showed the correlation between the fibrillation of the carboxymethylated cellulose (CMCe) fibers, the sonication power and time, and the relative size of the active zone below the sonication horn.

SFRS11 Loss Leads to Aging-Associated Cognitive Decline by Modulating LRP8 and ApoE.

RNA binding proteins, the key regulators in gene expression at the posttranscriptional level, remain largely uncharacterized with respect to aging and relevant cognitive deterioration. Here, we report that the levels of SFRS11 are substantially decreased in the prefrontal cortex (PFC) of aged brains. Notably, mice with SFRS11 deficiency in the PFC show impaired learning and memory. We demonstrate that SFRS11 directly binds to the 3' UTR of LRP8 mRNA, as well as to the third exon of apoE mRNA, resulting in stabilization of these mRNAs, eventually deactivating JNK signaling. Importantly, restoration of LRP8 and apoE reduces JNK signaling that is significantly enhanced in SFRS11-deficient cells. In addition, LRP8 and apoE rescue aging-like phenotypes induced by SFRS11 loss. Our findings demonstrate that age-dependent loss of SFRS11 in the PFC reduces levels of apoE and LRP8, leading to activation of the JNK pathway, ultimately influencing cognitive deficits.

The Age-dependent Elevation of miR-335-3p Leads to Reduced Cholesterol and Impaired Memory in Brain.

MiR-335-3p, a neuron-enriched microRNA, has been reported to be involved in aging and age-related neurological diseases. However, the role of miR-335-3p in cholesterol metabolism of astrocytes, and whether it affects neuronal functions, particularly during aging process, largely remains unknown. In this study, we uncover that miR-335-3p is significantly increased in aged cultured astrocytes and aged hippocampal brains, accompanied by decreased cellular cholesterol and diminished expression of HMGCR (3-hydroxy-3-methylglutaryl-CoA reductase) and 3-hydroxy-3-methylglutaryl-CoA synthase-1 (HMGCS1), both step-limiting enzymes in cholesterol synthesis pathway. We also demonstrate that miR-335-3p suppresses HMGCS1 post-transcriptionally by directly binding to its 3'UTR, and HMGCR through binding mediated by SFRS2. More importantly, aged mice with miR-335-3p deficiency in hippocampal brains exhibit improved learning and memory, accompanied by enhanced levels of postsynaptic density protein 95 (PSD95). We further reveal that the level change of PSD95 is resulted from altered cholesterol metabolism. Our findings provide a novel insight into the regulatory role of miR-335-3p in cholesterol metabolism in astrocytes, and consequently cognitive functions during aging.

A facile synthesis of segmented silver nanowires and enhancement of the performance of polymer solar cells.

In this work, segmented silver nanowires (AgNWs) with an average diameter of 60 nm have been successfully synthesized by a typical polyol method without any templates and seeds. The synthesized segmented AgNWs were strongly dependent on the reaction temperature and time. It was found from high-resolution transmission electron microscopy and selected area electron diffraction measurements that the connection node of segmented AgNWs was in the form of a twinned crystal. We speculated that these segmented AgNWs were possibly derived from end-to-end self-connection and self-concrescence of two neighbouring Ag nanorods or nanowires at a suitable reaction temperature and time, which is further confirmed by the secondary growth of AgNWs. In addition, segmented AgNWs were blended into hole transporting layers to enhance the performance of polymer solar cells (PSCs) by utilizing their localized surface plasmon resonance and optical scattering effects. As a result, the power conversion efficiency (PCE) and short-circuit current density (Jsc) of PSCs with segmented AgNWs increased from 2.81% and 8.99 mA cm-2 to 3.30% and 9.95 mA cm-2, respectively.

Nanosized CoO Loaded on Copper Foam for High-Performance, Binder-Free Lithium-Ion Batteries.

The synthesis of nanosized CoO anodes with unique morphologies via a hydrothermal method is investigated. By adjusting the pH values of reaction solutions, nanoflakes (CoO-NFs) and nanoflowers (CoO-FLs) are successfully located on copper foam. Compared with CoO-FLs, CoO-NFs as anodes for lithium ion batteries present ameliorated lithium storage properties, such as good rate capability, excellent cycling stability, and large CoO nanoflakes; CoO nanoflowers; anodes; binder free; lithium ion batteriesreversible capacity. The initial discharge capacity is 1470 mA h g-1, while the reversible capacity is maintained at 1776 m Ah g-1 after 80 cycles at a current density of 100 mA h g-1. The excellent electrochemical performance is ascribed to enough free space and enhanced conductivity, which play crucial roles in facilitating electron transport during repetitive Li⁺ intercalation and extraction reaction as well as buffering the volume expansion.

Efficient Quantum-Dot Light-Emitting Diodes Employing Thermally Activated Delayed Fluorescence Emitters as Exciton Harvesters.

Utilization of triplet excitons plays a key role in obtaining highly efficient quantum-dot light-emitting diodes (QD-LEDs). However, to date, only phosphorescent materials have been implemented to harvest triplet excitons in QD-LEDs. In this work, we introduced a thermally activated delayed fluorescence (TADF) emitter, 4,5-di(9H-carbazol-9-yl)phthalonitrile (2CzPN), doped into poly(N-vinylcarbazole) (PVK) as an exciton harvester in red QD-LEDs by solution processing. As a result, electrons leaking to the PVK layer will be trapped by 2CzPN to form long-lifetime TADF excitons in the 2CzPN:PVK layer, and then this harvested exciton energy can be effectively transferred to the adjacent QDs by the Förster resonance energy-transfer process. The fabricated red CdSe/CdS core/shell QD-LEDs show a maximum luminescence efficiency of 17.33 cd/A and longer lifetime. Our results demonstrate that the TADF sensitizer would be a promising candidate to develop highly efficient QD-LEDs.