Hole transport layer (HTL)‐free carbon‐based perovskite solar cells (C‐PSCs) show promising commercial application potential due to their attractive advantages of low cost and high stability. ...However, the power conversion efficiency of C‐PSCs is relatively low, mainly due to the poor crystalline quality of the C‐PSC applicable perovskite films and the energy level mismatch between the perovskite and carbon electrode. Herein, a moisture‐induced secondary crystal growth strategy to simultaneously improve the crystalline quality and optimize the energy level of perovskite film is proposed. The presence of moisture renders the surface of perovskite grains reactive by forming metastable intermediates. It is demonstrated that the commonly considered harmful intermediates can trigger secondary crystal growth. This secondary growth strategy results in improved crystallinity, larger grain size, and better morphology of the perovskite films, which reduce the density of defect states and also benefit the interface contact between the perovskite film and carbon electrode. Furthermore, the secondary growth modulates the surface composition of the film to achieve an optimized energy level alignment. As a result, this secondary growth strategy reduces the charge recombination loss and accelerates the charge transport process in C‐PSCs. Consequently, a new record efficiency of 19.52% is achieved for HTL‐free C‐PSCs.
A moisture‐induced secondary crystal growth strategy is proposed to enhance the crystalline quality of thick perovskite films. The secondary growth results in improved crystal quality of the perovskite film and also optimizes energy level alignment. The efficiency of hole transport layer‐free carbon‐based perovskite solar cells is boosted to 19.52%.
In this review, direct cyanation, hydrocyanation, dicyanation, cyanofunctionalization and other cyanation reactions of alkynes were highlighted. Firstly, the use of nitriles and development of ...cyanation was simply introduced. After presenting the natural properties of alkynes, cyanation reactions of alkynes were classified and introduced in detail. Transition metal catalysed direct cyanation and hydrocyanation of alkynes gave alkynyl cyanides and alkenyl nitriles in good yields. Dicyanation of alkynes produced 1,2-dicyano adducts. Cyanofunctionalization of alkynes afforded functional cyanated compounds. Thiocyanation and selenocyanation yielded the expected functional vinylthiocyanates and vinylselenocyanates. A plausible reaction mechanism is presented if available.
Cyanation of alkynes was highlighted. Direct cyanation and hydrocyanation gave alkynyl cyanides and alkenyl nitriles. Dicyanation produced 1,2-dicyano adducts. Cyanofunctionalization afforded functional cyano compounds.
► Moisture content, temperature and frequency have effects on permittivities of chestnut. ► Polynomials can describe relationship between permittivities and moisture content and temperature. ► Large ...penetration depth at radio frequencies may provide large-scale treatment for drying chestnut.
Dielectric properties of compressed chestnut flour samples with 11.6–48.0% w.b. moisture content were determined with a network analyzer and an open-ended coaxial-line probe over a frequency range from 10 to 4500MHz and a temperature range from 20 to 60°C. The results showed that the permittivities of chestnut flour were a function of frequency, moisture content and temperature. Both dielectric constant and loss factor decreased with increasing frequency but increased with increasing moisture content and temperature. The relationship between permittivities and moisture content and temperature at 27, 40, 915 and 2450MHz could be described by second- or third-degree polynomial models, with the coefficients of determination higher than 0.993. The analysis of variance showed that moisture content and temperature had strong significant effects on permittivity values. The penetration depth decreased with increasing frequency, moisture content and temperature. Large penetration depth at radio frequencies below 100MHz may provide practical large-scale dielectric drying of chestnut.
The CO
emission-mitigation policies adopted in different Chinese cities are important for achieving national emission-mitigation targets. China faces enormous inequalities in terms of regional ...economic development and urbanization, with some cities growing rapidly, while others are shrinking. This study selects 280 cities in China and divides them into two groups of growing cities and two groups of shrinking cities. This is achieved using an index called "urban development degree," which is calculated based on economic, demographic, social, and land-use indicators. Then, the 280 cities' CO
emission characteristics are examined, and extended STIRPAT (stochastic impacts by regression on population, affluence, and technology) is used to verify the influencing factors. We find that rapidly growing cities (RGCs) present a trend of fluctuating growth in CO
emissions, rapidly shrinking cities (RSCs) show an inverted U-shaped trend, and slightly growing (SGCs) and slightly shrinking cities (SSCs) show a trend of rising first, followed by steady development. Moreover, for growing cities, the population, economy, and proportion of tertiary industry have positive effects on carbon emissions, while technology has negative effects. For shrinking cities, the population and economy have significant positive effects on carbon emissions, while technology and the proportion of tertiary industry have negative effects.
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•Wide-bandgap FA-based perovskite film was prepared in a high-humidity air environment.•The crystallization quality of FA-based perovskite film was significantly improved by promoting ...the nucleation rate.•A high efficiency of 17.69% was obtained for the hole transport layer-free carbon electrode-based perovskite solar cells.
The preparation of high-efficiency perovskite solar cells (PSCs) in the ambient air environment has been challenging, especially for methylamine-free formamidine (FA)-based PSCs. One of the essential reasons is the slow nucleation rate of perovskite in a high-humidity air environment, leading to the uncontrolled growth of the intermediate phase and poor crystalline quality of the film. Here, we focus on the preparation of wide-bandgap FA-based perovskite films in the ambient air environment. A simple component engineering strategy is proposed to regulate the crystallization process of perovskite film. The nucleation process of perovskite can be significantly promoted by modulating the interaction of components in the precursor solution. The uncontrollable growth of the one-dimensional intermediate phase is suppressed, ultimately resulting in the improvement of the crystallinity of perovskite films. The defect state density of the film is significantly reduced, and the non-radiative recombination processes are effectively suppressed. The efficiency of the hole transport layer (HTL)-free carbon-based PSCs (C-PSCs) reached 17.69 %, which is the highest efficiency of HTL-free C-PSCs prepared with wide-bandgap perovskite (>1.6 eV).
Summary
Transcription activator‐like (TAL) effectors are major virulence factors secreted by the type III secretion systems of Xanthomonas oryzae pv. oryzicola (Xoc) and X. oryzae pv. oryzae (Xoo), ...causing bacterial leaf streak and bacterial blight, respectively, in rice. However, the knowledge of Xoc TAL effector function in promoting bacterial virulence remains limited.
Here, we isolated the highly virulent Xoc strain HGA4 from the outbreak region of Huanggang (Hubei, China), which contains four TAL effectors not found in the Chinese model strain RS105. Among these, Tal2b was selected for introduction into RS105, which resulted in a longer lesion length than that in the control.
Tal2b directly binds to the promoter region of the gene and activates the expression of OsF3H03g, which encodes 2‐oxoglutarate‐dependent dioxygenase in rice. OsF3H03g negatively regulates salicylic acid (SA)‐related defense by directly reducing SA, and it plays a positive role in susceptibility to both Xoc and Xoo in rice.
OsF3H03g interacts with a uridine diphosphate‐glycosyltransferase protein (OsUGT74H4), which positively regulates bacterial leaf streak susceptibility and may inactivate SA via glycosylation modification.
The novel conductive polyvinylidene fluoride (PVDF) fibrous membrane with high conductivity and sensitivity was successfully prepared via electrostatic spinning and efficient silver reduction ...technology. Based on the selective dissolution of porogen of polyvinylpyrrolidone (PVP), the porous PVDF fibrous membrane with excellent adsorbability and mechanical strength was obtained, providing a structure base for the preparation of conductive PVDF fibrous membrane with silver nanoparticles (AgNPs-PVDF). The Ag
in the AgNO
mixed solution with PVP was absorbed and maintained in the inner parts and surface of the porous structure. After the reducing action of ascorbic acid-mixed solution with PVP, silver nanoparticles were obtained tightly in an original porous PVDF fibrous membrane, realizing the maximum conductivity of 2500 S/m. With combined excellent conductivity and mechanical strength, the AgNPs-PVDF fibrous membrane effectively and sensitively detected strain signals of throat vocalization, elbow, wrist, finger, and knee (gauge factor of 23). The electrospun conductive AgNPs-PVDF combined the characteristics of low resistance, high mechanical strength, and soft breathability, which provided a new and effective preparation method of conductive fibers for practical application in wearable devices.
Vibrio fischeri is widely used as the model species in toxicity and risk assessment. For the first time, a global classification model was proposed in this paper for a two-class problem (Class − 1 ...with log1/IBCsub.50 ≤ 4.2 and Class + 1 with log1/IBCsub.50 > 4.2, the unit of IBCsub.50: mol/L) by utilizing a large data set of 601 toxicity log1/IBCsub.50 of organic compounds to Vibrio fischeri. Dragon software was used to calculate 4885 molecular descriptors for each compound. Stepwise multiple linear regression (MLR) analysis was used to select the descriptor subset for the models. The ten molecular descriptors used in the classification model reflect the structural information on the Michael-type addition of nucleophiles, molecular branching, molecular size, polarizability, hydrophobic, and so on. Furthermore, these descriptors were interpreted from the point of view of toxicity mechanisms. The optimal support vector machine (SVM) model (C = 253.8 and γ = 0.009) was obtained with the genetic algorithm. The SVM classification model produced a prediction accuracy of 89.1% for the training set (451 log1/IBCsub.50), of 80.0% for the test set (150 log1/IBCsub.50), and of 86.9% for the total data set (601 log1/IBCsub.50), which are higher than that (80.5%, 76%, and 79.4%, respectively) from the binary logistic regression (BLR) model. The global SVM classification model is successful, although it deals with a large data set in relation to the toxicity of organics to Vibrio fischeri.
ABSTRACT
Vascular aging has a strong relationship with cardiovascular disease. Fos‐related antigen 1 (Fra‐1), also referred to as Fos‐like antigen 1, is a transcription factor and has been reported ...to be involved in many pathologic processes. Here, we demonstrate that Fra‐1 plays a critical role in angiotensin II (Ang II)—induced vascular senescence. Fra‐1 expression is increased significantly in Ang II—induced rat aortic endothelial cell (RAEC) senescence and the arteries from Ang II—infused mice. Interestingly, silencing Fra‐1 blocks Ang II—induced senescence phenotypes in RAECs, including decreased senescence‐associated β‐galactosidase staining, and mitigated proliferation suppression and senescence‐associated secretory phenotype. Further, knocking down Fra‐1 inhibits vascular aging phenotypes in an Ang II—infused mice model. The up‐regulated Fra‐1 also exists in human atherosclerotic plaques and Ang II—induced vascular smooth muscle cells as well as in replicated senescence RAECs. Mechanistic studies reveal that Fra‐1 preferentially associates with c‐Jun and binds to the cyclin‐dependent kinase inhibitor 1a (p21) and cyclin‐dependent kinase inhibitor 2a (p16) promoter region, leading to elevated gene expression, which causes senescence‐related phenotypes. In conclusion, our results identify that Fra‐1 plays a novel and key role in promoting vascular aging by directly binding and transcriptionally activating p21 and p16 signaling, suggesting intervention of Fra‐1 is a potential strategy for preventing aging‐associated cardiovascular disorders.—Yang, D., Xiao, C., Long, F., Wu, W., Huang, M., Qu, L., Liu, X., Zhu, Y. Fra‐1 plays a critical role in angiotensin II—induced vascular senescence. FASEB J. 33, 7603–7614 (2019). www.fasebj.org
Acute-on-chronic liver failure (ACLF) is associated with a considerably high mortality, and accurate prognosis prediction is critical to navigate intervention decisions and improve clinical outcomes. ...The objective of this study was to establish a better prognostic model for ACLF based on multiparameter ultrasound in combination with clinical features.
A total of 149 patients with ACLF were prospectively enrolled and underwent conventional ultrasound, 2-D shear wave elastography (SWE), attenuation imaging, color Doppler sonography, superb microvascular imaging and contrast-enhanced ultrasound (CEUS). Univariate and multivariate analyses were performed to identify independent ultrasound signatures for the prognosis of ACLF, which, when integrated with clinical characteristics, were used to establish a prognostic model.
Hepatic perfusion features of CEUS differed significantly between the poor and good prognosis groups, among which the time interval (TI) between peak portal vein (PV) velocity and liver parenchyma (LP) enhancement, TI(PV, LP), was independently associated with the prognosis of ACLF. A prediction model comprising TI(PV, LP) and the international normalized ratio was established, and the area under the curve (AUC) was 0.851, which is greater than those of the Model for End-stage Liver Disease (0.785), fall time of LP model (0.754), 2-D SWE nomogram (0.708) and TI(PV, LP) (0.352). Furthermore, the performance of the model was verified in an independent validation cohort (AUC = 0.920).
The newly developed model performs better than existing tested models; thus, it has potential as a better non-invasive model for predicting the prognosis of patients with ACLF. A future multicenter, large-sample study is required to validate the performance of this model.
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