All‐inorganic lead halide perovskite quantum dots (IHP QDs) have great potentials in photodetectors. However, the photoresponsivity is limited by the low charge transport efficiency of the IHP QD ...layers. High‐performance phototransistors based on IHP QDs hybridized with organic semiconductors (OSCs) are developed. The smooth surface of IHP QD layers ensures ordered packing of the OSC molecules above them. The OSCs significantly improve the transportation of the photoexcited charges, and the gate effect of the transistor structure significantly enhances the photoresponsivity while simultaneously maintaining high Iphoto/Idark ratio. The devices exhibit outstanding optoelectronic properties in terms of photoresponsivity (1.7 × 104 A W−1), detectivity (2.0 × 1014 Jones), external quantum efficiency (67000%), Iphoto/Idark ratio (8.1 × 104), and stability (100 d in air). The overall performances of our devices are superior to state‐of‐the‐art IHP photodetectors. The strategy utilized here is general and can be easily applied to many other perovskite photodetectors.
High‐performance hybrid phototransistors based on all‐inorganic lead halide perovskite quantum dots and organic semiconductors are fabricated and characterized. Because of the outstanding properties of the materials, the gate‐tunable phototransistors exhibit significantly high performance, including photoresponsivity (≈1.7 × 104 A W−1), detectivity (≈2.0 × 1014 Jones), EQE (≈67000%), Iphoto/Idark ratio (≈8.1 × 104), and long‐term stability in air.
Monolayer VSe2, featuring both charge density wave and magnetism phenomena, represents a unique van der Waals magnet in the family of metallic 2D transition‐metal dichalcogenides (2D‐TMDs). Herein, ...by means of in situ microscopy and spectroscopic techniques, including scanning tunneling microscopy/spectroscopy, synchrotron X‐ray and angle‐resolved photoemission, and X‐ray absorption, direct spectroscopic signatures are established, that identify the metallic 1T‐phase and vanadium 3d1 electronic configuration in monolayer VSe2 grown on graphite by molecular‐beam epitaxy. Element‐specific X‐ray magnetic circular dichroism, complemented with magnetic susceptibility measurements, further reveals monolayer VSe2 as a frustrated magnet, with its spins exhibiting subtle correlations, albeit in the absence of a long‐range magnetic order down to 2 K and up to a 7 T magnetic field. This observation is attributed to the relative stability of the ferromagnetic and antiferromagnetic ground states, arising from its atomic‐scale structural features, such as rotational disorders and edges. The results of this study extend the current understanding of metallic 2D‐TMDs in the search for exotic low‐dimensional quantum phenomena, and stimulate further theoretical and experimental studies on van der Waals monolayer magnets.
Monolayer VSe2 represents a unique system for exploring the interplay between charge density wave and magnetism phenomena. Evidence of spin frustration is obtained in monolayer VSe2, which is significant toward the search for exotic low‐dimensional quantum phases and further theoretical and experimental studies of van der Waals monolayer magnets.
Climate change and public health are two interconnected societal challenges. Curbing fossil-based electricity generation reduces the emissions of both CO2 and air pollutants, which brings tangible ...health benefits from improved air quality. The potential health benefits from decarbonizing the grid are enormous, immediate, and widespread. From renewable portfolio standards to carbon market, the health co-benefits from clean electricity policies often outweigh their policy costs. As climate action goes local, framing decarbonization around health benefits also makes it more personally relevant and economically attractive. Yet, to date, the health impacts have largely been viewed as ancillary benefits from decarbonization, rather than as a core consideration when energy strategies are formed, assessed and implemented. When strategic choices are made about retiring old infrastructure and building new ones, bringing public health to the center of the discussion can generate greater health benefits with more equitable distribution. Here we identify concrete ways to incorporate air quality and health considerations into power sector decarbonization strategies. We draw insights mainly from empirical and modeling evidence for the United States. These insights are generally applicable and could guide health-oriented decarbonization efforts in other countries as well.
Ag electrode is widely used in inverted perovskite solar cells (PSCs), but its easy reaction and corrosive nature with perovskite always induces severe stability issue. Here, from typical theory of ...metal anticorrosion, a chemical anticorrosion approach for Ag electrode in inverted PSCs through introducing 2‐mercaptobenzothiazole (MBT) as a corrosion inhibitor is reported. MBT can strongly bond to Ag and form a compact MBT‐Ag chain on Ag surface owing to its N atom in thiazolyl ring and exocyclic thiol groups. As a result, Ag anticorrosion ability is greatly enhanced by increasing the corrosion potential and decreasing the corrosion current, thus effectively inhibiting possible chemical reaction and corrosion between perovskite and Ag electrodes. PSCs containing MBT/Ag exhibit high efficiency of over 23% with good stability, retaining 95 ± 4.1% of initial efficiency after storage for 3800 h in glovebox. Importantly, resulting PSCs also show excellent thermal stability, maintaining 90 ± 1.8% of initial efficiency after aging for 900 h at 85 °C.
A chemical anticorrosion strategy is proposed to inhibit Ag electrode corrosion in inverted perovskite solar cells through introducing 2‐mercaptobenzothiazole (MBT) inhibitor. MBT can bond on Ag surface to inhibit Ag corrosion. Resulting devices exhibit >23% efficiency with good stability, retaining >90% of initial efficiency whether after N2 storage for 3800 h or 85 °C aging for 900 h.
Lung adenocarcinoma (ADC) is the predominant histological type of lung cancer, and radiotherapy is one of the current therapeutic strategies for lung cancer treatment. Unfortunately, biological ...complexity and cancer heterogeneity contribute to radioresistance development. Karyopherin α2 (KPNA2) is a member of the importin α family that mediates the nucleocytoplasmic transport of cargo proteins. KPNA2 overexpression is observed across cancer tissues of diverse origins. However, the role of KPNA2 in lung cancer radioresistance is unclear. Herein, we demonstrated that high expression of KPNA2 is positively correlated with radioresistance and cancer stem cell (CSC) properties in lung ADC cells. Radioresistant cells exhibited nuclear accumulation of KPNA2 and its cargos (OCT4 and c‐MYC). Additionally, KPNA2 knockdown regulated CSC‐related gene expression in radioresistant cells. Next‐generation sequencing and bioinformatic analysis revealed that STAT1 activation and nuclear phospholipid scramblase 1 (PLSCR1) are involved in KPNA2‐mediated radioresistance. Endogenous PLSCR1 interacting with KPNA2 and PLSCR1 knockdown suppressed the radioresistance induced by KPNA2 expression. Both STAT1 and PLSCR1 were found to be positively correlated with dysregulated KPNA2 in radioresistant cells and ADC tissues. We further demonstrated a potential positive feedback loop between PLSCR1 and STAT1 in radioresistant cells, and this PLSCR1‐STAT1 loop modulates CSC characteristics. In addition, AKT1 knockdown attenuated the nuclear accumulation of KPNA2 in radioresistant lung cancer cells. Our results collectively support a mechanistic understanding of a novel role for KPNA2 in promoting radioresistance in lung ADC cells.
Nuclear KPNA2 promotes radioresistance and regulates cancer stem cell properties in lung adenocarcinoma cells. A loop between PLSCR1 and STAT1 is involved in KPNA2‐mediated radioresistance.
Composting is widely used for recycling of urban sewage sludge to improve soil properties, which represents a potential pathway of spreading antibiotic resistant bacteria and genes to soils. However, ...the dynamics of antibiotic resistance genes (ARGs) and the underlying mechanisms during sewage sludge composting were not fully explored. Here, we used high-throughput quantitative PCR and 16S rRNA gene based illumina sequencing to investigate the dynamics of ARGs and bacterial communities during a lab-scale in-vessel composting of sewage sludge. A total of 156 unique ARGs and mobile genetic elements (MGEs) were detected encoding resistance to almost all major classes of antibiotics. ARGs were detected with significantly increased abundance and diversity, and distinct patterns, and were enriched during composting. Marked shifts in bacterial community structures and compositions were observed during composting, with Actinobacteria being the dominant phylum at the late phase of composting. The large proportion of Actinobacteria may partially explain the increase of ARGs during composting. ARGs patterns were significantly correlated with bacterial community structures, suggesting that the dynamic of ARGs was strongly affected by bacterial phylogenetic compositions during composting. These results imply that direct application of sewage sludge compost on field may lead to the spread of abundant ARGs in soils.
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•Moringa-Fu brick tea extract improved obesity in rats induced by high-fat diet.•Moringa-Fu brick tea extract reduced cholesterol accumulation by regulating bile acid ...metabolism.•Moringa-Fu brick tea extract effectively regulated the structure and relative abundance of microbioa associated with bile salt hydrolase (BSH) activity.
Obesity is regarded to be correlated with disorders of lipid metabolism, bile acid metabolism and dysbiosis of the gut microbiota. Moringa-Fu brick tea (MFBT), a functional food, has a significant anti-obesity effect. However, the effectiveness and mechanisms of MFBT in preventing obesity require further investigation. Here, our results show that moringa-Fu brick tea extract (MFTE) displays anti-obesity effects by reducing high-fat diet-induced weight gain and adipose tissue accumulation in rats, and attenuating visceral adiposity index, oxidative stress and inflammation. In addition, MFTE could regulate gut microbiota diversity, reduce the relative abundance of microbioa associated with bile salt hydrolase (BSH) activity, such as Blautia, Ruminococcaceae, Coprococcus and Roseburia. Moreover, MFTE could improve the expression of the main rate-limiting enzymes CYP7A1 and CYP27A1 in the process of bile acid synthesis, downregulate the expression of intestinal FXR protein, promote the serum bile acid level, and reduce the accumulation of cholesterol in serum and liver. Taken together, these results suggested that MFBT could serve as a functional food for prevention of obesity and hyperlipidemia in association with regulating bile acid metabolism and gut microbiota.
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•Ordered porous hierarchical TiO2 (hier-TiO2) was synthesized by sintering MOFs.•The scaffold of scattered distribution was prepared by hier-TiO2 nanostructures.•The crystallization ...of perovskite was controlled due to ordered porous hier-TiO2.•Grains with enlarged sizes were formed due to scaffold of scattered distribution.•PSCs with hier-TiO2 scaffold show higher efficiency and better stability.
A type of quasi-mesoscopic perovskite solar cells (QM-PSCs) with porous hierarchical TiO2 (hier-TiO2) nanostructures of scattered distribution as scaffold was investigated. The porous hier-TiO2 nanostructures were synthesized by sintering MIL-125(Ti) of metal-organic frameworks (MOFs) at 500°C in air and which were partly inherited from the ordered porosity of MIL-125(Ti). The ordered hier-TiO2 nanostructures were scattered on compact TiO2 layer to form a quasi-mesoscopic scaffold of scattered distribution, which can offer enough growth space for perovskite grains and promote the ordered growth of perovskite grains. The QM-PSCs shows a power conversion efficiency (PCE) of 16.56%, much higher than PCE (11.38%) of PSCs with conventional small TiO2 nanoparticles (npt-TiO2) as scaffold and PCE (6.07%) of planar PSCs with compact TiO2 layer. The PCEs of PSCs with hier-TiO2 and npt-TiO2 remain 47% and 22% of the initial PCE values aging for 30days in air, indicating that PSCs with hier-TiO2 scaffold shown better stability and moisture resistance. The enhanced performance of QM-PSCs is primarily attributed to the superior wettability quasi-mesoscopic scaffold with ordered porous hier-TiO2 nanostructures, which help to form the high quality perovskite film with better crystillinity and less pin-holes, and improve the contact properties between perovksite and electron transport layer.
Rationale
Accumulating evidence has linked prolonged exposure to heavy metals to cancer occurrence in the urinary system. However, the specific biological mechanisms responsible for the association ...of heavy metals with the unusually high incidence of upper tract urothelial carcinoma in Taiwan are complex and incompletely understood.
Methods
To elucidate the specific biological mechanism and identify molecular indicators of the unusually high association of upper tract urothelial carcinoma with heavy metal exposure, protein expression following the treatment of T24 human bladder carcinoma and RT4 human bladder papilloma cell line models with arsenic (As) and cadmium (Cd) was studied. Proteomic changes in these cell models were integrated with data from a human bladder cancer (BLCA) tissue proteome to identify possible protein indicators of heavy metal exposure.
Results
After mass spectrometry based proteomic analysis and verification by Western blotting procedures, we identified 66 proteins that were up‐regulated and 92 proteins that were down‐regulated in RT4 cell extracts after treatment with As or Cd. Some 52 proteins were up‐regulated and 136 proteins were down‐regulated in T24 cell extracts after treatment with Cd. We further confirmed that down‐expression of the PML (promyelocytic leukemia) protein was sustained for at least 75 days after exposure of bladder cells to As. Dysregulation of these cellular proteins by As was associated with three biological pathways. Immunohistochemical analyses of paraffin‐embedded BLCA tissue slides confirmed that PML protein expression was decreased in BLCA tumor cells compared with adjacent noncancerous epithelial cells.
Conclusions
These data suggest that PML may play an important role in the pathogenesis of BLCA and may be an indicator of heavy metal exposure in bladder cells.
Carbon nanotube (CNT) has been considered as an ideal cathode material for field emission application for a long time. To improve field emission properties, coating CNT films to form a composite ...cathode is an effective approach. However, few reports have studied and revealed the effect of coated layer thickness. Hence, in this study, we employed an Au layer to coat CNT cathodes with capability to precisely control the coated film thickness and systematically investigated the film thickness effect on field emission properties of the CNT composite field-emission devices. A nonmonotonic relationship between field emission performances and cathode film thickness was observed, and a high performance with a rather low turn-on field of 0.60 V/μm and an ultrahigh field enhancement factor near to 20000 was optimally demonstrated for the CNT composite cathode with an Au layer thickness of 3 nm. Based on experimental data and analysis, the nonmonotonic tendency was found mainly due to effective field emitter density, and the cathode conductivity works only for ultrathin films. Besides, the CNT composite cathode had good stability and uniformity for low heat contact resistant. The superior performance of the CNT cathode composited with a proper Au layer demonstrated potential applications in vacuum electronic devices and an optimized thickness of the coated layer was important for field emission enhancement of composite cathodes.
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•Screen-printed DWCNTs coated with controllable thicknesses of Au films act as the composite field emission cathodes.•The effective field emitter density is the main factor influencing the thickness dependent field emission performance.•Best performance of rather low Eto and Eth with an ultrahigh β is achieved for the cathode with an optimized Au layer thickness of 3 nm.•The conductivity of composite cathode only has a slight influence on field emission properties for thick films.
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