Perovskite solar cells (PSCs) have achieved certified power conversion efficiency (PCE) over 25%. Though their high PCE can be achieved by optimizing absorber layer and device interfaces, the ...intrinsic instability of perovskite materials is still a key issue to be resolved. Mixed‐halide perovskites using multiple halogen constituents have been proved to improve robustness; however, the anion at the X site in the ABX3 formula is not limited to halogens. Other negative monovalent ions with similar properties to halogens, such as pseudo‐halogens, have the opportunity to form perovskites with ABX3 stoichiometry. Recently, thiocyanates and formates have been utilized to synthesize stable perovskite materials. This review presents the evolution of pseudo‐halide perovskite solar cells in the past few years. The intrinsic properties, their effects on crystal structure, and bandgap engineering of the pseudo‐halide perovskites are summarized. Various thiocyanate compounds applied in the fabrication of perovskite solar cells are discussed. The fabrication process, film formation mechanism, and crystallinity of pseudo‐halide perovskites are elucidated to understand their effects on the photovoltaic performance and device stability. Other applications of pseudo‐halide perovskites are summarized in the final section. Lastly, this review concludes with suggestions and outlooks for further research directions.
Monovalent pseudo‐halide anions share similar properties to halide anions. This review presents the evolution of pseudo‐halide perovskite solar cells in the past few years. The role of pseudo‐halides and their position and occupation in perovskite crystal, its impact on perovskite film quality, solar cell stability and photovoltaic performance, and pseudo‐halide optoelectronic devices beyond solar cells are compared comprehensively.
Inspection of insect sticky paper traps is an essential task for an effective integrated pest management (IPM) programme. However, identification and counting of the insect pests stuck on the traps ...is a very cumbersome task. Therefore, an efficient approach is needed to alleviate the problem and to provide timely information on insect pests. In this research, an automatic method for the multi‐class recognition of small‐size greenhouse insect pests on sticky paper trap images acquired by wireless imaging devices is proposed. The developed algorithm features a cascaded approach that uses a convolutional neural network (CNN) object detector and CNN image classifiers, separately. The object detector was trained for detecting objects in an image, and a CNN classifier was applied to further filter out non‐insect objects from the detected objects in the first stage. The obtained insect objects were then further classified into flies (Diptera: Drosophilidae), gnats (Diptera: Sciaridae), thrips (Thysanoptera: Thripidae) and whiteflies (Hemiptera: Aleyrodidae), using a multi‐class CNN classifier in the second stage. Advantages of this approach include flexibility in adding more classes to the multi‐class insect classifier and sample control strategies to improve classification performance. The algorithm was developed and tested for images taken by multiple wireless imaging devices installed in several greenhouses under natural and variable lighting environments. Based on the testing results from long‐term experiments in greenhouses, it was found that the algorithm could achieve average F1‐scores of 0.92 and 0.90 and mean counting accuracies of 0.91 and 0.90, as tested on a separate 6‐month image data set and on an image data set from a different greenhouse, respectively. The proposed method in this research resolves important problems for the automated recognition of insect pests and provides instantaneous information of insect pest occurrences in greenhouses, which offers vast potential for developing more efficient IPM strategies in agriculture.
Abstract
Two-dimensional (2D) semiconducting monolayers such as transition metal dichalcogenides (TMDs) are promising channel materials to extend Moore’s Law in advanced electronics. Synthetic TMD ...layers from chemical vapor deposition (CVD) are scalable for fabrication but notorious for their high defect densities. Therefore, innovative endeavors on growth reaction to enhance their quality are urgently needed. Here, we report that the hydroxide W species, an extremely pure vapor phase metal precursor form, is very efficient for sulfurization, leading to about one order of magnitude lower defect density compared to those from conventional CVD methods. The field-effect transistor (FET) devices based on the proposed growth reach a peak electron mobility ~200 cm
2
/Vs (~800 cm
2
/Vs) at room temperature (15 K), comparable to those from exfoliated flakes. The FET device with a channel length of 100 nm displays a high on-state current of ~400 µA/µm, encouraging the industrialization of 2D materials.
All retroviruses, including HIV-1, display species-specific patterns of infection. The impaired growth of these retroviruses in foreign and sometimes even in their natural hosts often stems from the ...action of potent host-encoded "viral restriction factors" that form important protective components of the innate immune system. The discovery of APOBEC3G and related cytidine deaminases as one class of host restriction factors and of the action of HIV-1 Vif as a specific APOBEC3G antagonist have stimulated intense scientific interest. This Vif-APOBEC3G axis now forms a very attractive target for development of an entirely new class of anti-HIV drugs. In this review, we summarize current understanding of the mechanism of action of the APOBEC3 family of enzymes, their intriguing regulation within cells, the impact of these enzymes on viral evolution and disease progression, and their roles in controlling not only the replication of exogenous retroviruses but also the retrotransposition of endogenous retroelements.
UV irradiation can injure the epidermis, resulting in sunburn, inflammation, and cutaneous tissue disorders. Previous studies demonstrate that EGFR in keratinocytes can be activated by UVB and ...contributes to inflammation. Poly (ADP‐ribose) polymerase‐1 (PARP‐1) is a nuclear enzyme and plays an essential role in DNA repair under moderate stress. In this study, we set out to understand how PARP‐1 regulates UVB irradiation‐induced skin injury and interplays with EGFR to mediate the inflammation response. We found that PARP‐1 deficiency exacerbated the UVB‐induced inflammation, water loss, and back skin damage in mice. In human primary keratinocytes, UVB can activate PARP‐1 and enhance DNA damage upon PARP‐1 gene silencing. Moreover, PARP‐1 silencing and PARP inhibitor olaparib can suppress UVB‐induced COX‐2 and MMP‐1 expression, but enhance TNF‐α and IL‐8 expression. In addition, EGFR silencing or EGFR inhibition by gefitinib can decrease UVB‐induced COX‐2, TNF‐α, and IL‐8 expression, suggesting EGFR activation via paracrine action can mediate UVB‐induced inflammation responses. Immunoblotting data revealed that PARP‐1 inhibition decreases UVB‐induced EGFR and p38 activation. Pharmacological inhibition of p38 also dramatically led to the attenuation of UVB‐induced inflammatory gene expression. Of note, genetic ablation of PARP‐1 or EGFR can attenuate UVB‐induced ROS production, and antioxidant NAC can attenuate UVB‐induced EGFR‐p38 signaling axis and PARP‐1 activation. These data suggest the regulatory loops among EGFR, PARP‐1, and ROS upon UVB stress. PARP‐1 not only serves DNA repair function but also orchestrates interactions to EGFR transactivation and ROS production, leading to p38 signaling for inflammatory gene expression in keratinocytes.
Defect engineering represents a significant approach for atomically thick 2D semiconductor material development to explore the unique material properties and functions. Doping‐induced conversion of ...conductive polarity is particularly beneficial for optimizing the integration of layered electronics. Here, controllable doping behavior in palladium diselenide (PdSe2) transistor is demonstrated by manipulating its adatom‐vacancy groups. The underlying mechanisms, which originate from reversible adsorption/desorption of oxygen clusters near selenide vacancy defects, are investigated systematically via their dynamic charge transfer characteristics and scanning tunneling microscope analysis. The modulated doping effect allows the PdSe2 transistor to emulate the essential characteristics of photo nociceptor on a device level, including firing signal threshold and sensitization. Interestingly, electrostatic gating, acting as a neuromodulator, can regulate the adaptive modes in nociceptor to improve its adaptability and perceptibility to handle different danger levels. An integrated artificial nociceptor array is also designed to execute unique image processing functions, which suggests a new perspective for extension of the promise of defect engineered 2D electronics in simplified sensory systems toward use in advanced humanoid robots and artificial visual sensors.
Modulable conductive polarity is demonstrated in the PdSe2 ambipolar transistor by Se vacancy‐dominated defect engineering via laser irradiation. It endows the PdSe2 transistor‐based synaptic device with convertible plasticity to emulate the tunable adaptive features in the photo nociceptor, providing a new vista for the defect‐engineered van der Waals electronics to exploit novel applications toward advanced artificial intelligent machines.
Poly(ADP-ribose) polymerase-1 (PARP-1) plays an essential role in DNA repair by catalyzing the polymerization of ADP-ribose unit to target proteins. Several studies have shown that PARP-1 can ...regulate inflammatory responses in various disease models. The intracellular Nod-like receptor NLRP3 has emerged as the most crucial innate immune receptor because of its broad specificity in mediating immune response to pathogen invasion and danger signals associated with cellular damage. In our study, we found NLRP3 stimuli-induced caspase-1 maturation and IL-1β production were impaired by PARP-1 knockout or PARP-1 inhibition in bone marrow-derived macrophages (BMDM). The step 1 signal of NLRP3 inflammasome activation was not affected by PARP-1 deficiency. Moreover, ATP-induced cytosolic ROS production was lower in
Parp-1
−/−
BMDM, resulting in the decreased inflammasome complex assembly. PARP-1 can translocate to cytosol upon ATP stimulation and trigger the PARylation modification on NLRP3, leading to NLRP3 inflammasome assembly. PARP-1 was also a bridge between NLRP3 and thioredoxin-interacting protein (TXNIP) and participated in NLRP3/TXNIP complex formation for inflammasome activation. Overall, PARP-1 positively regulates NLRP3 inflammasome activation via increasing ROS production and interaction with TXNIP and NLRP3, leading to PARylation of NLRP3. Our data demonstrate a novel regulatory mechanism for NLRP3 inflammasome activation by PARP-1. Therefore, PARP-1 can serve as a potential target in the treatment of IL-1β associated inflammatory diseases.
Video-assisted thoracic surgery (VATS) lobectomy for non-small cell lung cancer (NSCLC) is increasingly popular. However, the oncologic soundness of VATS for patients with NSCLC as measured by ...long-term survival has not been proven. The objective here is to determine the overall survival (OS) and disease-free survival (DFS) in two well-matched groups of patients with NSCLC resected by VATS or thoracotomy.
We conducted a retrospective review of a prospective database to identify patients who had a lobectomy for NSCLC. A propensity score-matched analysis was done with variables of age, sex, smoking history, Charlson comorbidity index, forced expiratory volume in 1 second, lung diffusing capacity for carbon monoxide, histology, and clinical T and N status. Medical records were reviewed and survival was analyzed.
After matching, there were 208 patients in each group. Patient and tumor characteristics were similar. The VATS group had a shorter length of stay. More nodes (14.3 versus 11.3; p=0.001) and more nodal stations (3.8 versus 3.1; p<0.001) were removed by thoracotomy. No differences were seen in OS and DFS. Median follow-up was 36 months. More than 90% of patients had clinical stage I disease, with 3- and 5-year OS of 87.4% and 76.5%, respectively, for VATS, and 81.6% and 77.5%, respectively, for thoracotomy (p=0.672). Both the incidence and distribution of recurrence were similar. Multivariate Cox regression analyses of OS and DFS confirmed the noninferiority of VATS.
For patients with clinical stage I NSCLC, VATS lobectomy offered similar OS and DFS compared with thoracotomy. Thoracotomy offers a more thorough lymph node evaluation, and may be appropriate for patients with more advanced clinical disease.
The scaling of silicon metal-oxide-semiconductor field-effect transistors has followed Moore's law for decades, but the physical thinning of silicon at sub-ten-nanometre technology nodes introduces ...issues such as leakage currents
. Two-dimensional (2D) layered semiconductors, with an atomic thickness that allows superior gate-field penetration, are of interest as channel materials for future transistors
. However, the integration of high-dielectric-constant (κ) materials with 2D materials, while scaling their capacitance equivalent thickness (CET), has proved challenging. Here we explore transferrable ultrahigh-κ single-crystalline perovskite strontium-titanium-oxide membranes as a gate dielectric for 2D field-effect transistors. Our perovskite membranes exhibit a desirable sub-one-nanometre CET with a low leakage current (less than 10
amperes per square centimetre at 2.5 megavolts per centimetre). We find that the van der Waals gap between strontium-titanium-oxide dielectrics and 2D semiconductors mitigates the unfavourable fringing-induced barrier-lowering effect resulting from the use of ultrahigh-κ dielectrics
. Typical short-channel transistors made of scalable molybdenum-disulfide films by chemical vapour deposition and strontium-titanium-oxide dielectrics exhibit steep subthreshold swings down to about 70 millivolts per decade and on/off current ratios up to 10
, which matches the low-power specifications suggested by the latest International Roadmap for Devices and Systems
.
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