Mixed iodide‐bromide organolead perovskites with a bandgap of 1.70–1.80 eV have great potential to boost the efficiency of current silicon solar cells by forming a perovskite‐silicon tandem ...structure. Yet, the stability of the perovskites under various application conditions, and in particular combined light and heat stress, is not well studied. Here, FA0.15Cs0.85Pb(I0.73Br0.27)3, with an optical bandgap of ≈1.72 eV, is used as a model system to investigate the thermal‐photostability of wide‐bandgap mixed halide perovskites. It is found that the concerted effect of heat and light can induce both phase segregation and decomposition in a pristine perovskite film. On the other hand, through a postdeposition film treatment with benzylamine (BA) molecules, the highly defective regions (e.g., film surface and grain boundaries) of the film can be well passivated, thus preventing the progression of decomposition or phase segregation in the film. Besides the stability improvement, the BA‐modified perovskite solar cells also exhibit excellent photovoltaic performance, with the champion device reaching a power conversion efficiency of 18.1%, a stabilized power output efficiency of 17.1% and an open‐circuit voltage (V
oc) of 1.24 V.
Using a postdeposition film treatment with benzylamine (BA) molecules, the highly defective regions of the wide‐bandgap FA0.15Cs0.85Pb(I1−
x
Br
x
)3 films can be well passivated, thus preventing the progression of decomposition or phase segregation in the film during combined heat and light stress. The BA‐treated perovskite solar cells exhibit a stabilized power output efficiency of 17.1% and an open‐circuit voltage (V
oc) of 1.24 V.
Summary
Suberin in roots acts as a physical barrier preventing water/mineral losses. In Arabidopsis, root suberization is regulated by abscisic acid (ABA) and ethylene in response to nutrient ...stresses. ABA also mediates coordination between microbiota and root endodermis in mineral nutrient homeostasis. However, it is not known whether this regulatory system is common to plants in general, and whether there are other key molecule(s) involved.
We show that serotonin acts downstream of ABA in regulating suberization in rice and Arabidopsis and negatively regulates suberization in rice roots in response to salinity. We show that ABA represses transcription of the key gene (OsT5H) in serotonin biosynthesis, thus promoting root suberization in rice. Conversely, overexpression of OsT5H or supplementation with exogenous serotonin represses suberization and reduces tolerance to salt stress.
These results identify an ABA‐serotonin regulatory module controlling root suberization in rice and Arabidopsis, which is likely to represent a general mechanism as ABA and serotonin are ubiquitous in plants.
These findings are of significant importance to breeding novel crop varieties that are resilient to abiotic stresses and developing strategies for production of suberin‐rich roots to sequestrate more CO2, helping to mitigate the effects of climate change.
Covering: December 2005 to June 2016. Previous review: Nat. Prod. Rep., 2006, 23, 673-698Over the last decade, great efforts have been made to conduct phytochemistry research on the genus Isodon, ...which have led to the isolation and identification of a number of diterpenoids. At the same time, these newly reported diterpenoids with diverse structures have led to new findings on their biological functions and chemical synthesis research. In this update, we review more than 600 new diterpenoids, including their structures, classifications, biogenetic pathways, bioactivities, and chemical synthesis.
• RBOHF from Arabidopsis thaliana represents a multifunctional NADPH oxidase regulating biotic and abiotic stress tolerance, developmental processes and guard cell aperture. The molecular components ...and mechanisms determining RBOHF activity remain to be elucidated.
• Here we combined protein interaction studies, biochemical and genetic approaches, and pathway reconstitution analyses to identify and characterize proteins that confer RBOHF regulation and elucidated mechanisms that adjust RBOHF activity.
• While the Ca2+ sensor-activated kinases CIPK11 and CIPK26 constitute alternative paths for RBOHF activation, the combined activity of CIPKs and the kinase open stomata 1 (OST1) triggers complementary activation of this NADPH oxidase, which is efficiently counteracted through dephosphorylation by the phosphatase ABI1. Within RBOHF, several distinct phosphorylation sites (p-sites) in the N-terminus of RBOHF appear to contribute individually to activity regulation.
• These findings identify RBOHF as a convergence point targeted by a complex regulatory network of kinases and phosphatases. We propose that this allows for fine-tuning of plant reactive oxygen species (ROS) production by RBOHF in response to different stimuli and in diverse physiological processes.
Sleep loss can induce or aggravate the development of cardiovascular and cerebrovascular diseases. However, the molecular mechanism underlying this phenomenon is poorly understood. The present study ...was designed to investigate the effects of REM sleep deprivation on blood pressure in rats and the underlying mechanisms of these effects. After Sprague-Dawley rats were subjected to REM sleep deprivation for 5 days, their blood pressures and endothelial function were measured. In addition, one group of rats was given continuous access to L-arginine supplementation (2% in distilled water) for the 5 days before and the 5 days of REM sleep deprivation to reverse sleep deprivation-induced pathological changes. The results showed that REM sleep deprivation decreased body weight, increased blood pressure, and impaired endothelial function of the aortas in middle-aged rats but not young rats. Moreover, nitric oxide (NO) and cyclic guanosine monophosphate (cGMP) concentrations as well as endothelial NO synthase (eNOS) phosphorylation in the aorta were decreased by REM sleep deprivation. Supplementation with L-arginine could protect against REM sleep deprivation-induced hypertension, endothelial dysfunction, and damage to the eNOS/NO/cGMP signaling pathway. The results of the present study suggested that REM sleep deprivation caused endothelial dysfunction and hypertension in middle-aged rats via the eNOS/NO/cGMP pathway and that these pathological changes could be inhibited via L-arginine supplementation. The present study provides a new strategy to inhibit the signaling pathways involved in insomnia-induced or insomnia-enhanced cardiovascular diseases.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Gait Energy Image (GEI) is an efficient template for human identification by gait. However, such a template loses temporal information in a gait sequence, which is critical to the performance of gait ...recognition. To address this issue, we develop a novel temporal template, named Chrono-Gait Image (CGI), in this paper. The proposed CGI template first extracts the contour in each gait frame, followed by encoding each of the gait contour images in the same gait sequence with a multichannel mapping function and compositing them to a single CGI. To make the templates robust to a complex surrounding environment, we also propose CGI-based real and synthetic temporal information preserving templates by using different gait periods and contour distortion techniques. Extensive experiments on three benchmark gait databases indicate that, compared with the recently published gait recognition approaches, our CGI-based temporal information preserving approach achieves competitive performance in gait recognition with robustness and efficiency.
Covering: February 2008 to May 2014. Previous review:
Nat
.
Prod
.
Rep
., 2008,
25
, 871-891
Several significant advances in the field of phytochemistry were made between 2008 and 2014 because of the ...high level of interest in Schisandraceae triterpenoids. In addition to a dramatic increase in the number of newly identified triterpenoids, the first complete synthesis of a schinortriterpenoid was accomplished. There has also been substantial progress in investigations of biological activity and mechanism of action. In this update, we review more than 250 new triterpenoids and describe their structures, classifications, biogenetic pathways, syntheses, and bioactivities.
Plants from the Schisandraceae family produce architecturally interesting triterpenoids, including lanostanes, cycloartanes, and schinortriterpenoids. This review focuses on their structures, classifications, biogenetic pathways, syntheses, and bioactivities (from February 2008 to May 2014).
We designed and built a new type of spatial mode multiplexer, based on Multi-Plane Light Conversion (MPLC), with very low intrinsic loss and high mode selectivity. In this first demonstration we show ...that a typical 3-mode multiplexer achieves a mode selectivity better than -23 dB and a total insertion efficiency of -4.1 dB (optical coating improvements could increase efficiency to -2.4 dB), across the full C-band. Moreover this multiplexer is able to perform any mode conversion, and we demonstrate its performance for the first 6 eigenmodes of a few-mode fiber: LP(01), LP(11a), LP(11b), LP(02), LP(21a) and LP(21b).
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•La0.9Mn0.8Ni0.2O3-δ (LMN) developed for C2H6 dehydrogenation to form C2H4 and H2.•Exsolved Ni particle in reduced LMN enhanced carbon resistance and dehydrogenation.•Increasing Ni ...surface increased C2H6 conversion and decreased C2H4/H2 selectivity.•LMN decomposition by excessive reduction deteriorated activity of dehydrogenation.
An A-site deficient and Ni-doped LaMnO3 perovskite (LMN) is prepared and reduced in 5% H2-N2 at 800 °C for 1 (R-LMN) and 6 (ER-LMN) h for evaluation as catalysts for C2H6 dehydrogenation to co-produce C2H4 and H2. The 1 h reduction causes the formation of Ni nanoparticles embedded in a perovskite substrate similar to LMN, but the excessive reduction for 6 h causes LMN decomposition to La2O3, MnO and Ni nanoparticles. The performance of the catalysts increases with increasing temperature. R-LMN demonstrates the highest performance among the catalysts studied, with 41.6% C2H6 conversion and 98.0% C2H4 selectivity at 750 °C; ER-LMN exhibits the lowest catalytic performance because of LMN decomposition. The performance of R-LMN is essentially stable during a 50 h test; and the slow growth of Ni nanoparticles slightly increases C2H6 conversion and decreases C2H4 selectivity due to the increase of the surface area of the Ni nanoparticles.
Suberin is a hydrophobic biopolymer that can be deposited at the periphery of cells, forming protective barriers against biotic and abiotic stress. In roots, suberin forms lamellae at the periphery ...of endodermal cells where it plays crucial roles in the control of water and mineral transport. Suberin formation is highly regulated by developmental and environmental cues. However, the mechanisms controlling its spatiotemporal regulation are poorly understood. Here, we show that endodermal suberin is regulated independently by developmental and exogenous signals to fine-tune suberin deposition in roots. We found a set of four MYB transcription factors (MYB41, MYB53, MYB92, and MYB93), each of which is individually regulated by these two signals and is sufficient to promote endodermal suberin. Mutation of these four transcription factors simultaneously through genome editing leads to a dramatic reduction in suberin formation in response to both developmental and environmental signals. Most suberin mutants analyzed at physiological levels are also affected in another endodermal barrier made of lignin (Casparian strips) through a compensatory mechanism. Through the functional analysis of these four MYBs, we generated plants allowing unbiased investigation of endodermal suberin function, without accounting for confounding effects due to Casparian strip defects, and were able to unravel specific roles of suberin in nutrient homeostasis.
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