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Viral suppressors of RNA silencing (VSRs) are encoded by diverse viruses to counteract the RNA silencing-mediated defence mounted by the virus-infected host cells. In this study, we identified the NSs protein encoded by tomato zonate spot virus (TZSV) as a potent VSR, and used a potato virus X (PVX)-based heterologous expression system to demonstrate TZSV NSs as a viral pathogenicity factor that intensified PVX symptoms in Nicotiana benthamiana. We then used a yeast two-hybrid screen to identify the suppressor of gene silencing 3 protein of N. benthamiana (NbSGS3), a known component of the plant RNA silencing pathway, as an interaction partner of TZSV NSs. We verified this interaction in plant cells with bimolecular fluorescence complementation, subcellular colocalization, and co-immunoprecipitation. We further revealed that the NSs-NbSGS3 interaction correlated with the VSR activity of TZSV NSs. TZSV NSs reduced the concentration of NbSGS3 protein in plant cells, probably through the ubiquitination and autophagy pathways. Interestingly, TZSV infection, but not NSs overexpression, significantly up-regulated the NbSGS3 transcript levels. Our data indicate that TZSV NSs suppresses RNA silencing of the host plant and enhances TZSV pathogenicity through its interaction with NbSGS3. This study reveals a novel molecular mechanism of NSs-mediated suppression of plant host antiviral defence.

Liver cancer is a malignant tumor with high morbidity and mortality, which has a tremendous negative impact on human survival. However, it is a challenging task to recognize tens of thousands of histopathological images of liver cancer by naked eye, which poses numerous challenges to inexperienced clinicians. In addition, factors such as long time-consuming, tedious work and huge number of images impose a great burden on clinical diagnosis. Therefore, our study combines convolutional neural networks with histopathology images and adopts a feature fusion approach to help clinicians efficiently discriminate the differentiation types of primary hepatocellular carcinoma histopathology images, thus improving their diagnostic efficiency and relieving their work pressure. In this study, for the first time, 73 patients with different differentiation types of primary liver cancer tumors were classified. We performed an adequate classification evaluation of liver cancer differentiation types using four pre-trained deep convolutional neural networks and nine different machine learning (ML) classifiers on a dataset of liver cancer histopathology images with multiple differentiation types. And the test set accuracy, validation set accuracy, running time with different strategies, precision, recall and F1 value were used for adequate comparative evaluation. Proved by experimental results, fusion networks (FuNet) structure is a good choice, which covers both channel attention and spatial attention, and suppresses channel interference with less information. Meanwhile, it can clarify the importance of each spatial location by learning the weights of different locations in space, then apply it to the study of classification of multi-differentiated types of liver cancer. In addition, in most cases, the Stacking-based integrated learning classifier outperforms other ML classifiers in the classification task of multi-differentiation types of liver cancer with the FuNet fusion strategy after dimensionality reduction of the fused features by principle component analysis (PCA) features, and a satisfactory result of 72.46% is achieved in the test set, which has certain practicality.

ZnO has been widely applied as an efficient electron transport material (ETM) in perovskite solar cells (PSCs) due to advantages including easy fabrication and superior electron mobility. However, the thermal instability of perovskite layers deposited on top of ZnO has been a notorious issue, impeding the development of ZnO-based PSCs. Herein, we demonstrate a simple in-situ grown ZnO nanocone arrays and solution-processed ultrathin Zn2SnO4 (ZTO) passivation layer. The latter not only circumvented the thermal instability issue by physically isolating the perovskite film and ZnO, but assisted in charge extraction efficiency between the ETM/perovskite interface by passivating the defects on ZnO surface. Consequently, ZTO-passivated ZnO ETM based PSCs delivered a power conversion efficiency as high as 18.3% with a Voc of 1.07 V, a Jsc of 23.2 mA/cm2, a FF of 0.74 and remarkably enhanced stability. Therefore, introduction of utilizing a thin ZTO layer shows strong promise in ultimately solving the thermal instability issue of ZnO-based PSCs, paving the way for their practical use by making full use of the prominent advantages offered by ZnO.

Aiming at the research problem of the valuation level of the stock market and its quantitative relationship with the fundamental index and liquidity index, this paper makes all the original data fall into the tolerable coverage domain through the method of series level ratio. The random error term of time series is eliminated by summation of sequence in grey prediction model. The cumulative time series is used as the input layer neuron of the neural network, and the grey neural network prediction model is established to quantitatively describe and predict the valuation level, and the weighted average price/sales ratio is used to obtain the overall valuation level of the science and technology innovation.

Cordycepin as the main active ingredient of Cordyceps militaris, a traditional medicinal fungus in China, has many physiological functions such as anti-cancer, anti-tumor and anti-virus activity. The most potential route for effective cordycepin production has been considered as liquid fermentation of C. militaris though with low productivity at present. Thus, it is urgent to apply both process engineering strategy and metabolic engineering strategy to enhance the productivity of cordycepin. In this review, the effects of medium components (i.e. the carbon/nitrogen source, precursor substances and metal ions) and operation factors (i.e. pH, dissolved oxygen and light) on cordycepin biosynthesis in liquid fermentation system are summarized. Besides, separation of cordycepin, the gene cluster involved and predicted biosynthesis pathways of cordycepin are also discussed, providing possible solutions of finally realizing efficient production of cordycepin.蛹虫草 Cordyceps militaris 是我国传统的药用真菌，虫草素是蛹虫草的主要活性成分，具有抗癌、抗肿瘤、抗病毒等多种生理功能。蛹虫草菌液体发酵是最有希望实现高效生产虫草素的途径，但现阶段生产强度低，亟需应用发酵工程及代谢工程手段提高虫草素产量。文中对液体发酵体系中培养基组分 (碳/氮源、前体物质、金属离子等) 和培养条件 (pH、溶氧量、光照等) 对虫草素产量的影响进行了总结，并对虫草素的分离纯化、生物合成基因簇及合成代谢途径进行了阐述，最后探讨了实现虫草素高效生产的关键环节。.

Recent advances in flexible perovskite solar cells (PSCs) have attracted considerable attention owing to their great potential for bendable and wearable electronic devices. In particular, developing high-quality low-temperature processed electron transport layers (ETLs) plays a pivotal role in realizing highly efficient flexible PSCs. Herein, we develop a facile strategy to fabricate graphene quantum dot/SnO2 composites (G@SnO2) as effective ETLs. Systematic optimization and investigation reveal that SnO2 blended with graphene quantum dots with ca. 5 nm diameter (G5@SnO2) has higher electron mobility, better film coverage and better energy level alignment compared to pristine SnO2, leading to promoted charge transfer and suppressed charge recombination. PSCs based on G5@SnO2 demonstrate superior photovoltaic performance with a champion power conversion efficiency (PCE) of 19.6% and average PCE of 19.0%. Amazingly, the G5@SnO2 based flexible PSCs obtain a best PCE and stabilized PCE of 17.7% and 17.2%, respectively, comparable to the highest PCEs recorded for flexible devices. Moreover, our flexible PSCs demonstrate outstanding mechanical durability, retaining over 91% of the initial PCE value after 500 bending cycles with a bending radius of 7 mm.

It is well recognized that the thickness of TiO2 film serving as hole blocking layer (bl-TiO2) in planar n-i-p structured perovskite solar cells is required to be thin for the purpose of reducing c...

Organic–inorganic hybrid perovskites have been emerging as promising light-harvesting materials for high-efficiency solar cells recently. Compared to solution-based methods, vapor-based deposition technologies are more suitable in preparing compact, uniform, and large-scale perovskite thin films. Here, we utilized flash-evaporation printing (FEP), a laser-induced ultrafast single source evaporation method employing a carbon nanotube evaporator, to fabricate high-quality methylammonium lead iodide perovskite thin films. Stoichiometric films with pure tetragonal perovskite phase can be achieved using a controlled methylammonium iodide to lead iodide ratio in evaporation precursors. The film crystallinity and crystal grain growth could further be promoted after postannealing. Planar solar cells (0.06 cm2) employing these perovskite films exhibit a champion power conversion efficiency (PCE) of 16.8% with insignificant hysteresis, which is among the highest reported PCEs using vapor-based deposition methods. L...

The hole extraction layer (HEL) plays a critical role in determining the charge extraction in inverted perovskite solar cells (PSCs) besides affecting the perovskite crystallization. Herein, we demonstrate efficient inverted perovskite solar cells based on solution-processed kesterite Cu2ZnSnS4 (CZTS) as the HEL for the first time. We achieved CZTS HEL with desired phase purity and optimal film coverage by optimizing the spin-coating process. Moreover, photoluminescence (PL) studies indicate that the CZTS HEL developed in this work provides superior hole extraction in comparison with the widely reported NiOx. This ultimately results in a respectable power conversion efficiency of 13.75% for the proof-of-concept device, reaching a level that is comparable to that of the NiOx-based device.

Significant efforts have been devoted to enhancing both the performance and long-term stability of lead halide perovskite solar cells (PSCs) to promote their practical application. In this context, a self-assembled monolayer composed of a dye molecule is demonstrated for the first time to be efficient in passivating the surface of the hole transport layer, NiOx, in the p–i–n PSCs through multiple functions, including the minimization of energy-level offset, reducing surface trap states, and enhancing wetting between NiOx and perovskite layers coupled with increasing perovskite crystallinity. Consequently, the dye monolayer has sufficiently improved the hole extraction efficiency and suppressed the charge recombination, validated by steady and transient photoluminescence measurements and the electrochemical impedance analysis. Concurrently, a mixed layer of BaSnO3 nanoparticles and [6,6]-phenyl-C61-butyric acid methyl (PCBM) (barium stannate (BSO)/PCBM) was exploited as an efficient electron transport laye...

Paper-based electronics have obtained increasing attention as they offer benefits of light weight, flexibility and low cost. In this work, heat-resistant borosilicate glass paper, showing extraordinary flexibility and being able to be treated at high temperature (~500 °C), is used as the substrate for flexible dye-sensitized solar cells (DSSCs) for the first time. High-quality photoanodes were prepared via a novel sequent filling method with the aid of poly(methyl methacrylate) PMMA and ice layers, leading to smooth and continuous TiO2 film. A complete different device structure design compared to the conventional one was also brought about, by taking advantage of using this photoanode as solid-state electrolyte supporter and being further connected with the counter-electrode. The prototype solar cell was successfully demonstrated for the first time, with a decent initiating photovoltaic performance, resulting in an efficiency of 0.85% (open-circuit voltage, Voc=0.67 V; short-circuit current density, Jsc=...

Electron-extraction layer (EEL) plays a critical role in determining the charge extraction and the power conversion efficiencies of the organometal-halide perovskite solar cells (PSCs). In this work, Ti–Fe–O ternary oxides were first developed to work as an efficient EEL in planar PSC. Compared with the widely used TiOx and the pure FeOx, the ternary composites show superior properties in multiple aspects including the excellent stability of the precursor solution, good coverage on the substrates, outstanding electrical properties, and suitable energy levels. By varying the Fe content from 0 to 100% in the Ti–Fe–O composites, the conductivity of the resultant compact layer was markedly improved, confirmed by consistent results from the conductive atomic force microscopy and the linear sweep voltammetry measurements. Meanwhile, the compositional engineering tunes the energy level alignment of the Ti–Fe–O EEL/CH3NH3PbI3 interface to a region that is favorable for obtaining excellent charge-extraction proper...

Wireless, battery-free optoelectronic systems enable localized tissue oximetry in tether-free, awake animal models., Monitoring regional tissue oxygenation in animal models and potentially in human subjects can yield insights into the underlying mechanisms of local O2-mediated physiological processes and provide diagnostic and therapeutic guidance for relevant disease states. Existing technologies for tissue oxygenation assessments involve some combination of disadvantages in requirements for physical tethers, anesthetics, and special apparatus, often with confounding effects on the natural behaviors of test subjects. This work introduces an entirely wireless and fully implantable platform incorporating (i) microscale optoelectronics for continuous sensing of local hemoglobin dynamics and (ii) advanced designs in continuous, wireless power delivery and data output for tether-free operation. These features support in vivo, highly localized tissue oximetry at sites of interest, including deep brain regions of mice, on untethered, awake animal models. The results create many opportunities for studying various O2-mediated processes in naturally behaving subjects, with implications in biomedical research and clinical practice.

Coastline is an important geographic background for each coastal area, and dynamic monitoring of coastlines is beneficial to coastal natural protection and further coastal construction and development. Based on the Landsat8 data and Sentinel-2 data from 2014 to 2019, this paper uses a method combining regional growth and edge detection to analyze the Cixi section’s coastline changes on the south bank of Hangzhou Bay. Firstly, the multi-source remote sensing data is preprocessed, and then the MNDWI value of each image is calculated. Then, each image is processed into a binary image by a regional growth algorithm. Eventually, we realize the coastline segmentation by the Canny operator of edge detection. The research represents that the coastline of the south coast of Hangzhou Bay moves toward the ocean year by year, and the length of the coastline generally decreases. The analysis may be caused by human-made activities in Hangzhou Bay Area in recent years, such as river cut-offs and urban construction. The research in this paper provides a reference for the protection of natural coastlines and human-made coastlines.

Non-obvious hysteresis and higher steady-state power conversion efficiency (PCE) were demonstrated by simply employing hematite (α-Fe2O3) as the electron transporting layer (ETL) to replace the conventional titania (TiO2) ETL in planar heterojunction perovskite solar cells. The achieved higher built-in potential across the perovskite layer for the devices using α-Fe2O3 ETLs led to more efficient charge extraction/transport and less charge recombination than using TiO2 ETLs. As a consequence, a significant reduction in the charge accumulation at the perovskite/α-Fe2O3 interface made the device much less sensitive to the scanning rate and direction, i.e., lower hysteresis. Furthermore, α-Fe2O3 based devices displayed good stability over 30 days of storage time with exposure to ambient air, owing to the higher crystalline quality and uniform grain size of the perovskite films deposited on α-Fe2O3 ETLs than on TiO2 ETLs.

Highly transparent and conductive aluminum doped zinc oxide (AZO) films were prepared by sol–gel method on the glass substrates. The effects of doping concentration, annealing temperature and facing direction during annealing on the structural, electrical and optical properties of AZO films were studied by performing a series of characterizations including X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, UV–vis spectrophotometry, four-point probe method and Hall effect measurement system. The results showed that the AZO films were wurtzite crystallized with c-axis preferred orientation. A minimum resistivity of 1.8 × 10 − 3 Ω cm and a transmittance above 90% were obtained for the film doped with 1.5 at.% aluminum, annealed at 510 °C and faced-down in the oven, which was among the best performance of the currently reported works based on sol–gel process. Moreover, energy level analysis revealed that the AZO film has a work function of 4.3 eV, exhibiting great potential in perovskite solar cell applications.

Inverted perovskite solar cells (PSCs) have been becoming more and more attractive, owing to their easy-fabrication and suppressed hysteresis, while the ion diffusion between metallic electrode and perovskite layer limit the long-term stability of devices. In this work, we employed a novel polyethylenimine (PEI) modified cross-stacked superaligned carbon nanotube (CSCNT) film in the inverted planar PSCs configurated FTO/NiO x/methylammonium lead tri-iodide (MAPbI3)/6, 6-phenyl C61-butyric acid methyl ester (PCBM)/CSCNT:PEI. By modifying CSCNT with a certain concentration of PEI (0.5 wt %), suitable energy level alignment and promoted interfacial charge transfer have been achieved, leading to a significant enhancement in the photovoltaic performance. As a result, a champion power conversion efficiency (PCE) of ∼11% was obtained with a Voc of 0.95 V, a Jsc of 18.7 mA cm-2, a FF of 0.61 as well as negligible hysteresis. Moreover, CSCNT:PEI based inverted PSCs show superior durability in comparison to the standard silver based devices, remaining over 85% of the initial PCE after 500 h aging under various conditions, including long-term air exposure, thermal, and humid treatment. This work opens up a new avenue of facile modified carbon electrodes for highly stable and hysteresis suppressed PSCs.

Organic-inorganic hybrid perovskites have been emerging as promising light-harvesting materials for high-efficiency solar cells recently. Compared to solution-based methods, vapor-based deposition technologies are more suitable in preparing compact, uniform, and large-scale perovskite thin films. Here, we utilized flash-evaporation printing (FEP), a laser-induced ultrafast single source evaporation method employing a carbon nanotube evaporator, to fabricate high-quality methylammonium lead iodide perovskite thin films. Stoichiometric films with pure tetragonal perovskite phase can be achieved using a controlled methylammonium iodide to lead iodide ratio in evaporation precursors. The film crystallinity and crystal grain growth could further be promoted after postannealing. Planar solar cells (0.06 cm

Perovskite solar cells (PSCs) have received tremendous attention due to their stunning progress in photovoltaic performance. The hysteresis behavior, however, is one of the major concerning issues accompanying the development of PSCs. In this context, we propose a new mechanism that explains the origin of hysteresis behavior by analyzing the electrical processes after changing the external electrical bias: the compensating electric field to the scanning voltage induced by drifting carriers. This is further verified by experiments, where we observed much reduced hysteresis in the current density–voltage (J–V) characteristics for the PSCs based on a thinner perovskite layer, which is a result of more evenly distributed electrons and holes. Moreover, light illumination with different wavelengths was applied to vary the initial carrier distribution inside the perovskite layer. We found that J–V curves when illuminating the device with longer wavelengths exhibited diminished hysteresis, which could be a result of more evenly generated carriers due to a smaller absorptivity than that with short wavelength illumination. Based on the proposed model, three key factors affecting the hysteresis behavior were pointed out, including the initial carrier distribution, the carrier transport properties in the perovskite layer, and the carrier extraction properties at the interfaces. Strategies to construct hysteresis-free and stable PSCs have thus been accordingly proposed.

Electron-extraction layer (EEL) plays a critical role in determining the charge extraction and the power conversion efficiencies of the organometal-halide perovskite solar cells (PSCs). In this work, Ti-Fe-O ternary oxides were first developed to work as an efficient EEL in planar PSC. Compared with the widely used TiO

Cu 2 ZnSnS 4 (CZTS) nanocrystals were synthesized successfully by two hot-injection methods, for which it was found that the temperature for sulfur precursor injection is an important factor to determine the morphology of nanocrystals. Injection carried out at a lower temperature lead to more homogeneous samples. Pure kesterite CZTS with diameter of about 15–20 nm was achieved confirmed by comprehensive characterizations including TEM, XRD, Raman, and XPS. Besides, CZTS nanocrystal based thin film, which was fabricated by solution process, exhibited a hole mobility of 4.3 × 10 −2 cm 2 /V-s. The film was then successfully incorporated into a Schottky solar cell, yielding an open circuit voltage of about 300 mV. It is notable that this was the first time that the completely nontoxic Schottky solar cell was achieved based on CZTS nanocrystal, which was fabricated completely under room temperature.

The Assembly of one-dimensional (1D) nanostructures such as nanowires/nanorods/nanotubes into two-dimensional (2D) macrostructured films is attracting considerable research interest because of their unique properties and wide applications. In this study, flexible membranes were successfully fabricated using α-MnO2 nanowires synthesized through a hydrothermal method. The effects of thickness and post-annealing temperature on the mechanical properties of the membranes were investigated in detail. Nano-indentation measurements showed that the modulus of the as-prepared 11.75 μm-thick membrane reached 5.765 GPa, and the modulus increased with the increasing post-annealing temperature. Thus, the fabricated membranes with superior mechanical strength can have potential applications such as in photocatalysis, filtering, and supporting substrates.

We report herein perovskite solar cells using solution-processed silver nanowires (AgNWs) as transparent top electrode with markedly enhanced device performance, as well as stability by evaporating an ultrathin transparent Au (UTA) layer beneath the spin-coated AgNWs forming a composite transparent metallic electrode. The interlayer serves as a physical separation sandwiched in between the perovskite/hole transporting material (HTM) active layer and the halide-reactive AgNWs top-electrode to prevent undesired electrode degradation and simultaneously functions to significantly promote ohmic contact. The as-fabricated semitransparent PSCs feature a Voc of 0.96 V, a Jsc of 20.47 mA cm(-2), with an overall PCE of over 11% when measured with front illumination and a Voc of 0.92 V, a Jsc of 14.29 mA cm(-2), and an overall PCE of 7.53% with back illumination, corresponding to approximately 70% of the value under normal illumination conditions. The devices also demonstrate exceptional fabrication repeatability and air stability.

Printing solutions have attracted wide attention from various research fields, but thin films made by printing technologies still cannot match the quality of the films made by conventional thin-film deposition methods. In this study, a flash-evaporation printing (FEP) technology, which employed a freestanding carbon nanotube (CNT) flash evaporator, was developed to address this issue and to achieve a compact physical vapor deposition geometry. The target material precoated on the CNT flash evaporator was printed onto a substrate by gas-phase transportation. The FEP methodology presented a printable solution for hybrid perovskite thin films. The as-fabricated photovoltaic devices showed power conversion efficiencies of ∼10.3%, and the thin films were also utilized as potential photodetectors. In addition, this technology can also be used to print patterns and a wide variety of materials on large panels. The environmentally friendly and cost-effective FEP technology will be of significant benefit to printed electronics, organic electronics and future flexible electronics. Integrating high-purity vapor sources into printing techniques noticeably boosts the performance of thin-film photovoltaics. Yang Wei from Tsinghua University, China, and his team developed an alternative to normally bulky thermal evaporators by coating metal frames with layers of ’super-aligned‘ carbon nanotubes, cross-stacked 15 sheets high. With a heat capacity over three orders of magnitude lower than metals, the carbon-nanotube stack warms up to 1,100 degrees Celsius instantly following laser stimulation. These thermal properties enable flash deposition of reagents from the tiny evaporator to a target substrate just a millimeter away. The researchers demonstrated the potential of this approach by flash depositing perovskite precursors as a thin film and then transforming them into solar cells with liquid chemicals. Analysis revealed the new fabrication technique fabricated the perovskite thin film with high quality, resulting in a high 10.3% power conversion efficiency. A flash-evaporation printing technology is developed that employs freestanding carbon nanotubes as a flash evaporator. The target materials precoated on the flash evaporator are printed onto substrates by gas-phase transportation. This methodology offers a printable solution for hybrid perovskite thin films, and can also be used to print patterns and a wide variety of materials on large panels.