Organic solar cells （OSCs） have advantages like light-weight, flexibility, colorfulness and solution processability 1 . The active layer of OSCs generally contains two organic semiconductors： an ...electron donor and an electron acceptor. The donor and acceptor make nanoscale phase separation to allow efficient exciton dissociation and also form a three-dimensional （3D） passage to rapidly transfer free charge carriers to respective electrodes.
Organic solar cells (OSCs) based on D18:Y6 have recently exhibited a record power conversion efficiency of over 18%. The initial work is extended and the device performance of D18‐based OSCs is ...compared with three non‐fullerene acceptors, Y6, IT‐4F, and IEICO‐4Cl, and their molecular packing characteristics and miscibility are studied. The D18 polymer shows unusually strong chain extension and excellent backbone ordering in all films, which likely contributes to the excellent hole‐transporting properties. Thermodynamic characterization indicates a room‐temperature miscibility for D18:Y6 and D18:IT‐4F near the percolation threshold. This corresponds to an ideal quench depth and explains the use of solvent vapor annealing rather than thermal annealing. In contrast, D18:IEICO‐4Cl is a low‐miscibility system with a deep quench depth during casting and poor morphology control and low performance. A failure of ternary blends with PC71BM is likely due to the near‐ideal miscibility of Y6 to begin with and indicates that strategies for developing successful ternary or quaternary solar cells are likely very different for D18 than for other high‐performing donors. This work reveals several unique property–performance relations of D18‐based photovoltaic devices and helps guide design or fabrication of yet higher efficiency OSCs.
Molecular packing and thermodynamic properties of D18‐based fullerene‐free organic solar cells are studied. The D18 polymer exhibits strong chain extension in films, which is beneficial to charge transport. Miscibility and other characterizations explain the disparate performance of three systems and the processing procedures.
Objective
Changes in gut microbiota have been linked to systemic lupus erythematosus (SLE), but knowledge is limited. Our study aimed to provide an in‐depth understanding of the contribution of gut ...microbiota to the immunopathogenesis of SLE.
Methods
Fecal metagenomes from 117 patients with untreated SLE and 52 SLE patients posttreatment were aligned with 115 matched healthy controls and analyzed by whole‐genome profiling. For comparison, we assessed the fecal metagenome of MRL/lpr mice. The oral microbiota origin of the gut species that existed in SLE patients was documented by single‐nucleotide polymorphism–based strain‐level analyses. Functional validation assays were performed to demonstrate the molecular mimicry of newly found microbial peptides.
Results
Gut microbiota from individuals with SLE displayed significant differences in microbial composition and function compared to healthy controls. Certain species, including the Clostridium species ATCC BAA‐442 as well as Atopobium rimae, Shuttleworthia satelles, Actinomyces massiliensis, Bacteroides fragilis, and Clostridium leptum, were enriched in SLE gut microbiota and reduced after treatment. Enhanced lipopolysaccharide biosynthesis aligned with reduced branched chain amino acid biosynthesis was observed in the gut of SLE patients. The findings in mice were consistent with our findings in human subjects. Interestingly, some species with an oral microbiota origin were enriched in the gut of SLE patients. Functional validation assays demonstrated the proinflammatory capacities of some microbial peptides derived from SLE‐enriched species.
Conclusion
This study provides detailed information on the microbiota of untreated patients with SLE, including their functional signatures, similarities with murine counterparts, oral origin, and the definition of autoantigen‐mimicking peptides. Our data demonstrate that microbiome‐altering approaches may offer valuable adjuvant therapies in SLE.
Wide bandgap polymer D18 with narrow photon harvesting in visible light range and small molecule N3 with near‐infrared photon harvesting are adopted for building semitransparent organic photovoltaics ...(OPVs). To find out the optimal D18:N3 weight ratio for semitransparent OPVs, series of opaque OPVs are built with a varied D18:N3 weight ratio. The power conversion efficiency (PCE) and fill factor can be maintained over 16% and 77% in the D18:N3 (0.7:1.6, wt/wt) based opaque OPVs, respectively. The average visible transmittance (AVT) of the corresponding blend films can be achieved over 50%, demonstrating the great potential in fabricating efficient semitransparent OPVs. The semitransparent OPVs based on D18:N3 (0.7:1.6, wt/wt) are fabricated by using 1 nm Au/(10, 15, 20 nm) Ag as cathode. The thickness of Ag layers is varied to balance the optical properties and electrical properties of semitransparent top electrode. The semitransparent OPVs with 10 nm Ag achieve the highest light utilization efficiency of 2.90% with a PCE of 12.91% and an AVT of 22.49%, which should be among the best performance of reported semitransparent OPVs. This work demonstrates that the wide bandgap polymer donor with narrow photon harvesting in visible light range has great potential in preparing efficient semitransparent OPVs.
A power conversion efficiency of 12.91% and an average visible transmittance of 22.49% are achieved in semitransparent organic photovoltaics (OPVs) with D18:N3 (0.7:1.6, wt/wt) as active layers. This work demonstrates that the wide bandgap polymer donor with narrow photon harvesting in the visible light range has great potential in preparing efficient semitransparent OPVs.
An electrically modulated single‐/dual‐color imaging photodetector with fast response speed is developed based on a small molecule (COi8DFIC)/perovskite (CH3NH3PbBr3) hybrid film. Owing to the type‐I ...heterojunction, the device can facilely transform dual‐color images to single‐color images by applying a small bias voltage. The photodetector exhibits two distinct cut‐off wavelengths at ≈544 nm (visible region) and ≈920 nm (near‐infrared region), respectively, without any power supply. Its two peak responsivities are 0.16 A W−1 at ≈525 nm and 0.041 A W−1 at ≈860 nm with a fast response speed (≈102 ns). Under 0.6 V bias, the photodetector can operate in a single‐color mode with a peak responsivity of 0.09 A W−1 at ≈475 nm, showing a fast response speed (≈102 ns). A physical model based on band energy theory is developed to illustrate the origin of the tunable single‐/dual‐color photodetection. This work will stimulate new approaches for developing solution‐processed multifunctional photodetectors for imaging photodetection in complex circumstances.
A tunable dual‐color imaging photodetector with a fast response speed (≈102 ns) is developed by constructing a type‐I p–n heterojunction of CH3NH3PbBr3/COi8DFIC. Dual‐color imaging can be switched to single‐color imaging by applying a small bias voltage.
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•Green natural versatile adsorbent (efficiently remove Cr(VI), Pb(II) and dyes).•Higher adsorption performance under batch and fixed-bed condition.•Convenient for large scale ...application.•Excellent stability, reusability and convenient separation.
Chitosan is highly suitable for removing metal ions and dyes from water; however, the sorption performance, stability and recycling are still critical issues in practical applications. Herein, polydopamine-modified-chitosan (CS-PDA) aerogels were synthesized through dopamine self-polymerization and glutaraldehyde cross-linking reactions to enhance the adsorption capacity and acid resistance of chitosan. The self-polymerization of dopamine and gelation of chitosan were accomplished simultaneously, simplifying the synthesis process of CS-PDA aerogels, which is meaningful for the popularization and industrial application of adsorbent. CS-PDA exhibited superior adsorption performances in the removal of Cr(VI), Pb(II) and organic dyes. Adsorption isotherms and kinetic data were well fitted by Langmuir and pseudo-second-order kinetic models. The maximum adsorption capacities of CS-PDA for Cr(VI) and Pb(II) were 374.4 and 441.2 mg g−1, respectively. After eight cycles, adsorption capacity of CS-PDA showed no obvious decline. These superiorities make CS-PDA a promising multifunctional adsorbent for the purification of metal ions and dyes.
In situ electron density measurements by the CHAllenging Minisatellite Payload and the Defense Meteorological Satellites Program F17 satellites show that the midlatitude ionization at altitudes of ...∼350 and 850 km is enhanced in the late evening. The enhancements increase to maximum around midnight and are clearly observed till early morning as the equatorial ionization decays to minimal level. They appear in the winter hemisphere during June and December solstices and in both hemispheres during equinox. The enhancements are well confined between ±30° and ±50° magnetic latitude, with the magnetic flux tubes of L = 1.3 − 2.4 connecting to the plasmasphere. Furthermore, coincident longitudinal variations exist in both the ionospheric enhancements and the plasmaspheric total electron content, especially during the solstice months. The coincidence may suggest essential plasma transport between the ionosphere and the plasmasphere. These facts support the idea that the plasmasphere provides extra plasma to the midlatitude ionosphere through downward plasma influx along the magnetic field lines to form the nighttime ionization enhancements when the sunlight is absent.
Key Points
Satellites reveal global pictures of nighttime enhancements in the midlatitude ionosphere at altitude of ∼350 and 850 km
We find correlation of longitudinal dependence between the ionospheric enhancements and the plasmasphere
The plasmasphere is suggested to feed and dominate the formation of the nighttime enhancements
Novel alginate/melamine/chitosan aerogel with high efficiency and selectivity for Pb(II) ions absorption.
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•Novel alginate/melamine/chitosan aerogel for efficient Pb(II) removal.•The ...adsorption capacity for Pb(II) ions with SA/ME/CS beads can reach 1331.6 mg/g.•The absorbents maintain well performance more than eight cycles.•Well selective adsorption ability for Pb(II) among ion competition systems.
Superior mechanical properties, high adsorption capacity, and excellent regeneration property are crucial design criterions to develop a new-type aerogel for adsorptive applications towards heavy metal removal from water. Herein, chitosan and melamine not only introduced abundant functional groups to increase adsorbing sites for lead ions, but also reinforced the three-dimensional network skeleton structure of absorbents to improve the service life in adsorption applications. As-fabricated alginate/melamine/chitosan aerogel can extract Pb (II) from aqueous solution efficiently, i.e., the optimum adsorption quantity of 1331.6 mg/g at pH 5.5, which exhibited excellent and selective adsorption capacity for Pb (II) against the competition of coexisting divalent metal ions. More importantly, alginate/melamine/chitosan aerogel could be regenerated using dilute acidic solution and recovered well after eight adsorption-desorption cycles. This work might offer a new idea for design and preparation of biomass-based aerogel sorbents with promising prospect in the remediation of Pb (II)-contaminated wastewater.
Background
To compare the adhesion properties and biofilm‐forming capabilities of 27 Candida isolates obtained from catheter‐related candidemia patients and to evaluate the inhibitory effects of ...antifungal agents on different Candida species.
Material and Methods
Seven C. albicans, six C. parapsilosis, five C. guilliermondii, five C. tropicalis, and four C. glabrata clinical isolates were investigated. We quantified the adherence of these Candida species by flow cytometric method and evaluated the formation of biofilms by XTT reduction and crystal violet methods. Actions of micafungin (MF), fluconazole (FZ), and N‐acetylcysteine (NAC) on the adhesion and biofilm formation of different Candida species were determined.
Results
Non‐albicans Candida species were demonstrated to have stronger adhesion abilities compared with C. albicans. The biofilm‐forming capabilities of different Candida species were varied considerably, and the degree of biofilm formation might be affected by different assay approaches. Interestingly, C. parapsilosis displayed the highest biofilm formation abilities, while C. glabrata exhibited the lowest total biomass and metabolic activity. Furthermore, the inhibitory activities of MF, FZ, and NAC on fungal adhesion and biofilm formation were evaluated, and the results indicated that MF could reduce the adhesion ability and biofilm metabolism more significantly (p < 0.05), and its antifungal activity was elevated in a dose‐dependent manner.
Conclusion
Non‐albicans Candida species, especially C. guilliermondii, C. tropicalis, and C. parapsilosis, exhibited higher adhesion ability in catheter‐related candidemia patients. However, these Candida species had varied biofilm‐forming capabilities. MF tended to have stronger inhibitory effects against both adhesion and biofilm formation of different Candida species.
Representation of Candida adhesion profiles. The isolates were characterized by weak, moderate, strong and very strong adhesion patterns. Homogeneous distribution pattern means that yeast cells are attached to an equal amount of microspheres; while heterogeneous distribution pattern indicates that multiple microspheres are bound to a single yeast cell.
Organic semiconductors have attracted tremendous attention in the past few years, thanks to their excellent flexibility, solution‐processability, low‐cost, chemical versatility, etc. Particularly, ...organic solar cells based on ternary heterojunctions have shown remarkable device performance, with the recent development of nonfullerene acceptor materials. These novel materials are also promising for photodetection. However, there are several key limits facing organic photodetectors, such as relatively large bandgaps, poor charge transport, and stability. In this work, a novel nonfullerene acceptor—COi8DFIC—is introduced, blended with a fullerene derivative and a donor to form ternary heterojunctions. After optimization, photodiodes based on such ternary blends exhibit compelling performance metrics, including low dark current, decent responsivity, large linear dynamic range, fast response, and excellent stability. This device performance is actually on a par with the established silicon technology, suggesting great potential for photodetection and imaging.
Ternary organic heterojunction based photodiodes are achieved with broadband photoresponse covering the whole visible and near‐infrared range. These photodiodes exhibit enhanced figure of merits, including relatively low dark current and noise, decent responsivity, large linear dynamic range, fast response, and superior stability, indicating remarkable potential for next generation photodetection and imaging.
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