Improving power conversion efficiencies (PCEs) and stability are two main tasks for organic photovoltaic (OPV) cells. In the past few years, although the PCE of the OPV cells has been considerably ...improved, the research on device stability is limited. Herein, a cross‐linkable material, cross‐linked 6,6‐phenyl‐C61‐butyric styryl dendron ester (c‐PCBSD), is applied as an interfacial modification layer on the surface of zinc oxide and as the third component into the PBDB‐TF:Y6‐based OPV cells to enhance photovoltaic performance and long‐term stability. The PCE of the OPV cells that underwent the two‐step modification increased from 15.1 to 16.1%. In particular, such OPV cells exhibited much better stability under both thermal and air conditions because of the decreased number of interfacial defects and stable interfacial and active layer morphologies. The results demonstrated that the introduction of a cross‐linkable fullerene derivative into the interfacial and active layers is a feasible method to improve the PCE and stability of OPV cells.
Organic photovoltaic cells with enhanced photovoltaic performance and long‐term stability are achieved via introducing a cross‐linkable material (c‐PCBSD) as an interfacial modification layer on the surface of zinc oxide and as the third component into the PBDB‐TF:Y6 system OPV cells, which provides a new idea for device engineering.
Co3O4/nitrogen‐doped carbon hollow spheres (Co3O4/NHCSs) with hierarchical structures are synthesized by virtue of a hydrothermal method and subsequent calcination treatment. NHCSs, as a hard ...template, can aid the generation of Co3O4 nanosheets on its surface; while SiO2 spheres, as a sacrificed‐template, can be dissolved in the process. The prepared Co3O4/NHCS composites are investigated as the electrode active material. This composite exhibits an enhanced performance than Co3O4 itself. A higher specific capacitance of 581 F g−1 at 1 A g−1 and a higher rate performance of 91.6% retention at 20 A g−1 are achieved, better than Co3O4 nanorods (318 F g−1 at 1 A g−1 and 67.1% retention at 20 A g−1). In addition, the composite is employed as a positive electrode to fabricate an asymmetric supercapacitor. The device can deliver a high energy density of 34.5 Wh kg−1 at the power density of 753 W kg−1 and display a desirable cycling stability. All of these attractive results make the unique hierarchical Co3O4/NHCS core–shell structure a promising electrode material for high‐performance supercapacitors.
The Co3O4/N‐doped carbon hollow sphere (Co3O4/NHCS) with a core–shell structure, where Co3O4 nanosheets serve as the shell and NHCS as the core, has large surface area and hierarchical porous structure. The asymmetric supercapacitor assembled with Co3O4/NHCS as a positive electrode and activated carbon as a negative electrode exhibits an excellent electrochemical performance.
Gastrointestinal microbiota may be involved in
associated gastric cancer development. The aim of this study was to explore the possible microbial mechanisms in gastric carcinogenesis and potential ...dysbiosis arising from
infection.
Deep sequencing of the microbial 16S ribosomal RNA gene was used to investigate alterations in paired gastric biopsies and stool samples in 58 subjects with successful and 57 subjects with failed anti-
treatment, relative to 49
negative subjects.
In
positive subjects, richness and Shannon indexes increased significantly (both p<0.001) after successful eradication and showed no difference to those of negative subjects (p=0.493 for richness and p=0.420 for Shannon index). Differential taxa analysis identified 18 significantly altered gastric genera after eradication. The combination of these genera into a Microbial Dysbiosis Index revealed that the dysbiotic microbiota in
positive mucosa was associated with advanced gastric lesions (chronic atrophic gastritis and intestinal metaplasia/dysplasia) and could be reversed by eradication. Strong coexcluding interactions between
and
,
,
,
,
were found only in advanced gastric lesion patients, and were absent in normal/superficial gastritis group. Changes in faecal microbiota included increased
after successful
eradication and more upregulated drug-resistant functional orthologs after failed treatment.
infection contributes significantly to gastric microbial dysbiosis that may be involved in carcinogenesis. Successful
eradication potentially restores gastric microbiota to a similar status as found in uninfected individuals, and shows beneficial effects on gut microbiota.
Flexible planar micro‐supercapacitors (MSCs) with unique loose and porous nanofiber‐like electrode structures are fabricated by combining electrochemical deposition with inkjet printing. Benefiting ...from the resulting porous nanofiber‐like structures, the areal capacitance of the inkjet‐printed flexible planar MSCs is obviously enhanced to 46.6 mF cm−2, which is among the highest values ever reported for MSCs. The complicated fabrication process is successfully averted as compared with previously reported best‐performing planar MSCs. Besides excellent electrochemical performance, the resultant MSCs also show superior mechanical flexibility. The as‐fabricated MSCs can be highly bent to 180° 1000 times with the capacitance retention still up to 86.8%. Intriguingly, because of the remarkable patterning capability of inkjet printing, various modular MSCs in serial and in parallel can be directly and facilely inkjet‐printed without using external metal interconnects and tedious procedures. As a consequence, the electrochemical performance can be largely enhanced to better meet the demands of practical applications. Additionally, flexible serial MSCs with exquisite and aesthetic patterns are also inkjet‐printed, showing great potential in fashionable wearable electronics. The results suggest a feasible strategy for the facile and cost‐effective fabrication of high‐performance flexible MSCs via inkjet printing.
An effective general strategy to fabricate high‐performance flexible micro‐supercapacitors (MSCs) with porous nanofiber‐like electrode structures is presented. Benefited from the porous nanofiber‐like structures, the specific capacitance of the resultant MSCs is largely improved while averting the complicated fabrication process.
A side‐chain conjugation strategy in the design of nonfullerene electron acceptors is proposed, with the design and synthesis of a side‐chain‐conjugated acceptor (ITIC2) based on a ...4,8‐bis(5‐(2‐ethylhexyl)thiophen‐2‐yl)benzo1,2‐b:4,5‐b′di(cyclopenta‐dithiophene) electron‐donating core and 1,1‐dicyanomethylene‐3‐indanone electron‐withdrawing end groups. ITIC2 with the conjugated side chains exhibits an absorption peak at 714 nm, which redshifts 12 nm relative to ITIC1. The absorption extinction coefficient of ITIC2 is 2.7 × 105m−1 cm−1, higher than that of ITIC1 (1.5 × 105m−1 cm−1). ITIC2 exhibits slightly higher highest occupied molecular orbital (HOMO) (−5.43 eV) and lowest unoccupied molecular orbital (LUMO) (−3.80 eV) energy levels relative to ITIC1 (HOMO: −5.48 eV; LUMO: −3.84 eV), and higher electron mobility (1.3 × 10−3 cm2 V−1 s−1) than that of ITIC1 (9.6 × 10−4 cm2 V−1 s−1). The power conversion efficiency of ITIC2‐based organic solar cells is 11.0%, much higher than that of ITIC1‐based control devices (8.54%). Our results demonstrate that side‐chain conjugation can tune energy levels, enhance absorption, and electron mobility, and finally enhance photovoltaic performance of nonfullerene acceptors.
A side‐chain conjugation strategy in the design of nonfullerene electron acceptors is proposed and the first example of a side‐chain‐conjugated fused‐ring electron acceptor is presented. Polymer solar cells based on side‐chain‐conjugated ITIC2 show a champion power conversion efficiency of 11.0%, much higher than its counterpart ITIC1‐based devices (8.54%).
2D perovskites are recently attracting a significant amount of attention, mainly due to their improved stability compared with their 3D counterpart, e.g., the archetypical MAPbI3. Interestingly, the ...first studies on 2D perovskites can be dated back to the 1980s. The most popular 2D perovskites have a general formula of (RNH3)2MAn−1MnX3n+1, where n represents the number of metal halide octahedrons between the insulating organic cation layers. The optoelectronic properties of 2D perovskites, e.g., band gap, are highly dependent on the thickness of the inorganic layers (i.e., the value of n). Herein, 2D perovskites are arbitrarily divided into three classes, strict 2D (n = 1), quasi‐2D (n = 2–5), and quasi‐3D (n > 5), and research progress is summarized following this classification. The majority of existing 2D perovskites only employ very simple organic cations (e.g., butyl ammonium or phenylethyl ammonium), which merely function as the supporting layer/insulating barrier to achieve the 2D structure. Thus, a particularly important research question is: can functional organic cations be designed for these 2D perovskites, where these functional organic cations would play an important role in dictating the optoelectronic properties of these organic–inorganic hybrid materials, leading to unique device performance or applications?
Two‐dimensional perovskites typically have a general formula of (RNH3)2MAn−1MnX3n+1, and can be arbitrarily categorized into strict 2D (n = 1), quasi‐2D (n = 2−5), and quasi‐3D (n > 5). Research progress in each category is summarized, and it is proposed that designing functional organics to manipulate the optoelectronic properties of 2D perovskites can lead to unique device applications.
This work proposes the concept of single‐cell microRNA (miR) therapy and proof‐of‐concept by engineering a nanopipette for high‐precision miR‐21‐targeted therapy in a single HeLa cell with sensitive ...photoelectrochemical (PEC) feedback. Targeting the representative oncogenic miR‐21, the as‐functionalized nanopipette permits direct intracellular drug administration with precisely controllable dosages, and the corresponding therapeutic effects can be sensitively transduced by a PEC sensing interface that selectively responds to the indicator level of cytosolic caspase‐3. The experimental results reveal that injection of ca. 4.4 × 10−20 mol miR‐21 inhibitor, i.e., 26488 copies, can cause the obvious therapeutic action in the targeted cell. This work features a solution to obtain the accurate knowledge of how a certain miR‐drug with specific dosages treats the cells and thus provides an insight into futuristic high‐precision clinical miR therapy using personalized medicine, provided that the prerequisite single‐cell experiments are courses of personalized customization.
The concept of high‐precision single‐cell microRNA therapy is proposed and devised by a functional nanopipette, which allows precise miR‐21 inhibitor delivery to induce cell apoptosis and responds selectively to caspase‐3 of a sensitive photoelectrochemical feedback. It can reveal what the precise drug amount can cause the effective therapeutic action.
The research on the polymer-based solar cells (PSCs) has attracted an increasing amount of attention in recent years because PSCs pose potential advantages over mainstream inorganic-based solar ...cells, such as significantly reduced material/fabrication costs, flexible substrates, and light weight of finished solar cells. The research community has made great progress in the field of bulk heterojunction (BHJ) polymer solar cells since its inception in 1995. The power conversion efficiency (PCE), a key parameter to assess the performance of solar cells, has increased from 1% in the 1990s to over 8% just recently. These great advances are mainly fueled by the development of conjugated polymers used as the electron-donating materials in BHJ solar cells. In this Perspective, we first briefly review the progress on the design of conjugated polymers for polymer solar cells in the past 16 years. Since a conjugated polymer can be arbitrarily divided into three constituting componentsthe conjugated backbone, the side chains, and the substituentswe then focus on the rational design of conjugated polymers by separately discussing the influence of each component on the physical and photovoltaic (PV) properties of these polymers. Special attention is paid to the design of donor–acceptor type low-band-gap polymers because this approach is prevailing in the literature with its unique features. In doing so, we strive to extract useful rules for the rational design of conjugated polymers with predictable properties. We conclude by proposing future research opportunities to achieve even higher PCEs for PSCs.
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•A slightly halophilic strain with HN-AD function was isolated.•The HN-AD pathway follows NH4+ → NO2− → N2.•83.2% of ammonium was converted into nitrogen gas.•High NH4+-N removal can ...be achieved in saline (3–5% w/v) wastewater.
The utilization of halophilic bioresources is limited due to a lack of isolation and characterization work. A halophilic bacterium strain SND-01 of Exiguobacterium mexicanum was isolated in this study, which is the first report on its novel function in heterotrophic nitrification-aerobic denitrification (HN-AD). The strain SND-01 is slightly halophilic, surviving at 0 up to 9% (w/v) salinity. When utilizing ammonium, nitrate or nitrite as the sole nitrogen source in aerobic conditions, the isolated strain showed the maximum nitrogen removal rate of 2.24 ± 0.14 mg/(L·h), 3.63 ± 0.21 mg/(L·h) and 2.30 ± 0.23 mg/(L·h), respectively. Functional genes and key enzymes involved in heterotrophic-aerobic nitrogen transformations were characterized, establishing the pathway of HN-AD. The nitrogen removal via HN-AD is dependent on the C/N ratio, salinity and temperature. The halophilic Exiguobacterium mexicanum strain SND-01 shows a significant potential in biotreatment of saline wastewater in an easy and cost-effective way.
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