Low‐dimensional Ruddlesden–Popper (LDRP) perovskites are a current theme in solar energy research as researchers attempt to fabricate stable photovoltaic devices from them. However, poor exciton ...dissociation and insufficiently fast charge transfer slows the charge extraction in these devices, resulting in inferior performance. 1,4‐Butanediamine (BEA)‐based low‐dimensional perovskites are designed to improve the carrier extraction efficiency in such devices. Structural characterization using single‐crystal X‐ray diffraction reveals that these layered perovskites are formed by the alternating ordering of diammonium (BEA2+) and monoammonium (MA+) cations in the interlayer space (B‐ACI) with the formula (BEA)0.5MAn
PbnI3n+1. Compared to the typical LDRP counterparts, these B‐ACI perovskites deliver a wider light absorption window and lower exciton binding energies with a more stable layered perovskite structure. Additionally, ultrafast transient absorption indicates that B‐ACI perovskites exhibit a narrow distribution of quantum well widths, leading to a barrier‐free and balanced carrier transport pathway with enhanced carrier diffusion (electron and hole) length over 350 nm. A perovskite solar cell incorporating BEA ligands achieves record efficiencies of 14.86% for (BEA)0.5MA3Pb3I10 and 17.39% for (BEA)0.5Cs0.15(FA0.83MA0.17)2.85Pb3(I0.83Br0.17)10 without hysteresis. Furthermore, the triple cations B‐ACI devices can retain over 90% of their initial power conversion efficiency when stored under ambient atmospheric conditions for 2400 h and show no significant degradation under constant illumination for over 500 h.
A new type of ACI perovskite is prepared through the alternating ordering of BEA2+ and MA+ cations in the interlayer space (B‐ACI). The high exciton extraction efficiency and a narrow distribution of quantum well widths of B‐ACI perovskite enable a device with a record efficiency of 17.39%. Furthermore, the devices show stronger resistance to humidity, heating, and light soaks than previous equivalents.
Regulatory T cells (Tregs) and plasmacytoid dendritic cells (pDCs) play important roles in the immune escape of cancer. In this study, we investigated pDCs and pDC‐induced inducible costimulator ...(ICOS)+ Treg populations in peripheral blood from gastric cancer (GC) patients and healthy donors by flow cytometry. The distribution of these cells in carcinoma tissue, peritumor tissue, and normal gastric mucosa was detected by immunohistochemistry. Plasma and tissue concentration of the cytokines such as interleukin‐10 and transforming growth factor‐β1 were also measured. We found that the numbers of pDCs, Tregs, and ICOS+ Tregs in peripheral blood were increased in GC patients compared with healthy donors. In tissue, Tregs and ICOS+ Tregs were found distributing mainly in carcinoma tissue, whereas pDCs were mainly found in peritumor tissue. Moreover, the Foxp3+ICOS+/Foxp3+ cell ratio in carcinoma and peritumor tissue were higher than that in normal tissue. There were more ICOS+ Tregs in tumor and peritumor tissue of late‐stage GC patients. There was a positive correlation between pDCs and ICOS+ Tregs in peripheral blood and peritumor tissue from GC patients. In conclusion, pDCs may play a potential role in recruiting ICOS+ Tregs, and both participate in the immunosuppression microenvironment of GC.
We found that numbers of pDCs, Tregs and ICOS+ Tregs in peripheral blood were increased in GC patients compared with healthy donors. In tissue, Tregs and ICOS+ Tregs were found distributing mainly in carcinoma tissue, while pDCs mainly in peritumor tissue. Both pDCs and ICOS+ Tregs participate in the immunosuppression microenviroment of gastric cancer together.
Although incorporating multiple halogen (bromine) anions and alkali (rubidium) cations can improve the open‐circuit voltage (Voc) of perovskite solar cells (PSCs), severe voltage loss and poor ...stability have remained pivotal limitations to their further commercialization. In this study, acetylcholine (ACh+) is anchored to the surface of a quadruple‐cation perovskite to provide additional electron states near the valence band maximum of the perovskite surface, thereby enhancing the band alignment and minimizing the Voc loss significantly. Moreover, the quaternary ammonium and carbonyl units of ACh+ passivate the antisite and vacancy defects of the organic/inorganic hybrid perovskite. Because of strong interactions between ACh+ and the perovskite, the formation of lead clusters and the migration of halogen anions in the perovskite film are suppressed. As a result, the device prepared with ACh+ post‐treatment delivers a power conversion efficiency (PCE) (21.56%) and a value of Voc (1.21 V) that are much higher than those of the pristine device, along with a twofold decrease in the hysteresis index. After storage for 720 h in humid air, the device subjected to ACh+ treatment maintained 70% of its initial PCE. Thus, post‐treatment with ACh+ appears to be a useful strategy for preparing efficient and stable PSCs.
Anchoring acetylcholine on the surface of a perovskite film regulates the band‐edge state near the valence band maximum of the surface and inhibits the migration of halogen ions. Consequently, the voltage loss and stability of corresponding perovskite solar cells are greatly improved, suggesting a new direction toward their further commercialization.
We present a new method for the reconstruction of rational functions through finite-fields sampling that can significantly reduce the number of samples required. The method works by exploiting all ...the independent linear relations among target functions. Subsequently, the explicit solutions of the functions can be efficiently obtained by solving the linear system. As a first application, we utilize the method to address various examples within the context of Feynman integrals reduction. These examples demonstrate that our method can substantially improve the computational efficiency, making it useful for future computations in particle physics.
Traditionally chemical modifications altering molecular skeletons (MSs) were the only solution to modulate material active sites at ground states. According to Runge–Gross theorem, the MS and the ...adjoint electron‐configuration (MS‐AEC) can be tuned at excited states (ESs), even without chemical modifications. A porphyrinic metal–organic framework PCN‐222 and its metalloporphyrin homologs are used for adsorptive carbon capture both at ground states and with photoexcitation (350–780 nm). Instead of passive photothermal effects, the carbon capture performances of all the adsorbents get promotions. The dominant first ESs with long lifetimes meet the time‐scale of molecular adsorption equilibrium, meanwhile tune the MS‐AEC of the porphyrin ligands to generate new active sites with much more negative electrostatic‐potentials, of which the distribution gradient is crucial for inducing CO2 and can be further modulated by the central‐coordinated metal cations at ground and excited states. This work demonstrates the availability of static ESs and possibility of nonchemical modifications.
In comparison to severe acute respiratory syndrome coronavirus (SARS-CoV), SARS-CoV-2 appears to be more contagious 1, and coronavirus disease 2019 (COVID-19) patients demonstrate varied clinical ...manifestations distinct from those seen in patients with SARS-CoV and Middle East respiratory syndrome coronavirus infections 2. Collective results from the clinical and epidemiological observations suggest a distinct viral–host interaction in COVID-19 patients. Profiling of the antibody response during SARS-CoV-2 infection may help improve our understanding of the viral–host interaction and the immunopathological mechanisms of the disease.
Humoral immune response to SARS-CoV-2 showed an early response of IgA, instead of IgM, in COVID-19 patients. As highlighted by this study, enhanced IgA responses observed in severe COVID-19 might confer damaging effects in severe COVID-19.
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Efficient brain drug delivery has been a challenge in the treatment of Alzheimer's disease (AD) and other brain disorders as blood‐brain barrier (BBB) impedes most drugs to reach brain. To overcome ...this obstacle, a novel poly(lactic‐co‐glycolic acid) (PLGA) nanoparticle conjugated with CD47 extracellular domain via reactive oxygen species (ROS)‐responsive phenylborate ester bond exhibiting “do not eat me” signal and BBB penetrating peptide CRTIGPSVC (CRT) and microglia modulation agent Nec‐1s encapsulated in it is developed. The experimental results show that the designed nanoparticle efficiently increases its half‐life in blood circulation by preventing engulfment via phagocytes, and enhances its brain distribution by synergistic effect of CD47 and CRT. The high level of ROS in mouse brain releases CD47 from the nanoparticles and the resultant particles are effectively phagocytized by resident microglia. The engulfed Nec‐1s modulates pathological microglia to a beneficial state, which reduces Aβ burden, microgliosis and astrocytosis, decreases cytokine production and oxidative stress in the brains of AD mice, and finally attenuates cognition deficits and synapse loss. The results first demonstrate that the conditionally releasable “do not eat me” CD47 signal remarkably facilitates microglia‐targeted drug delivery and warrants further study to develop therapeutic agent for AD treatment.
A poly(lactic‐co‐glycolic acid) (PLGA) nanoparticle conjugated with the “do not eat me” CD47 signal via reactive oxygen species‐responsive bond and blood‐brain barrier penetrating peptide CRTIGPSVC is developed for microglia‐targeted Nec‐1s delivery. This nanoparticle shows increased brain distribution and microglial delivery of drug via conditionally releasable CD47 and can modulate pathological microglia to a beneficial state in Alzheimer's disease treatment.
Rechargeable aqueous Zn‐VOx batteries are attracting attention in large scale energy storage applications. Yet, the sluggish Zn2+ diffusion kinetics and ambiguous structure–property relationship are ...always challenging to fulfil the great potential of the batteries. Here we electrodeposit vanadium oxide nanobelts (VO‐E) with highly disordered structure. The electrode achieves high capacities (e.g., ≈5 mAh cm−2, 516 mAh g−1), good rate and cycling performances. Detailed structure analysis indicates VO‐E is composed of integrated amorphous‐crystalline nanoscale domains, forming an efficient heterointerface network in the bulk electrode, which accounts for the good electrochemical properties. Theoretical calculations indicate that the amorphous‐crystalline heterostructure exhibits the favorable cation adsorption and lower ion diffusion energy barriers compared to the amorphous and crystalline counterparts, thus accelerating charge carrier mobility and electrochemical activity of the electrode.
Vanadium oxide materials with the unique amorphous‐crystalline heterostructure are fabricated using an electrochemical method for the first time. The electrode displays good electrochemical performances as cathode for aqueous Zn‐ion batteries. Experimental and simulation results suggest that the amorphous‐crystalline heterostructure exhibits the favourable cation adsorption and ion diffusion properties compared to other modelling structures.
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