Graphene-based materials exhibit remarkable electronic, optical, and mechanical properties, which has resulted in both high scientific interest and huge potential for a variety of applications. ...Furthermore, the family of graphene-based materials is growing because of developments in preparation methods. Raman spectroscopy is a versatile tool to identify and characterize the chemical and physical properties of these materials, both at the laboratory and mass-production scale. This technique is so important that most of the papers published concerning these materials contain at least one Raman spectrum. Thus, here, we systematically review the developments in Raman spectroscopy of graphene-based materials from both fundamental research and practical (
i.e.
, device applications) perspectives. We describe the essential Raman scattering processes of the entire first- and second-order modes in intrinsic graphene. Furthermore, the shear, layer-breathing, G and 2D modes of multilayer graphene with different stacking orders are discussed. Techniques to determine the number of graphene layers, to probe resonance Raman spectra of monolayer and multilayer graphenes and to obtain Raman images of graphene-based materials are also presented. The extensive capabilities of Raman spectroscopy for the investigation of the fundamental properties of graphene under external perturbations are described, which have also been extended to other graphene-based materials, such as graphene quantum dots, carbon dots, graphene oxide, nanoribbons, chemical vapor deposition-grown and SiC epitaxially grown graphene flakes, composites, and graphene-based van der Waals heterostructures. These fundamental properties have been used to probe the states, effects, and mechanisms of graphene materials present in the related heterostructures and devices. We hope that this review will be beneficial in all the aspects of graphene investigations, from basic research to material synthesis and device applications.
This work provides a comprehensive understanding on the developments in the Raman spectroscopy of graphene-based materials from fundamental research studies to device applications.
SUMMARY
Sphingolipids have key functions in plant membrane structure and signaling. Perturbations of plant sphingolipid metabolism often induce cell death and salicylic acid (SA) accumulation; SA ...accumulation, in turn, promotes sphingolipid metabolism and further cell death. However, the underlying molecular mechanisms remain unclear. Here, we show that the Arabidopsis thaliana lipase‐like protein ENHANCED DISEASE SUSCEPTIBILITY 1 (EDS1) and its partner PHYTOALEXIN DEFICIENT 4 (PAD4) participate in sphingolipid metabolism and associated cell death. The accelerated cell death 5 (acd5) mutants accumulate ceramides due to a defect in ceramide kinase and show spontaneous cell death. Loss of function of EDS1, PAD4 or SALICYLIC ACID INDUCTION DEFICIENT 2 (SID2) in the acd5 background suppressed the acd5 cell death phenotype and prevented ceramide accumulation. Treatment with the SA analogue benzothiadiazole partially restored sphingolipid accumulation in the acd5 pad4 and acd5 eds1 double mutants, showing that the inhibitory effect of the pad4‐1 and eds1‐2 mutations on acd5‐conferred sphingolipid accumulation partly depends on SA. Moreover, the pad4‐1 and eds1‐2 mutations substantially rescued the susceptibility of the acd5 mutant to Botrytis cinerea. Consistent with this, B. cinerea‐induced ceramide accumulation requires PAD4 or EDS1. Finally, examination of plants overexpressing the ceramide synthase gene LAG1 HOMOLOGUE2 suggested that EDS1, PAD4 and SA are involved in long‐chain ceramide metabolism and ceramide‐associated cell death. Collectively, our observations reveal that EDS1 and PAD4 mediate ceramide (especially long‐chain ceramide) metabolism and associated cell death, by SA‐dependent and SA‐independent pathways.
Significance Statement
Several reports have investigated the roles of ceramides in plants; however, the mechanism by which ceramides elicit cell death remains to be elucidated. In this work we found that ENHANCED DISEASE SUSCEPTIBILITY 1 and its partner PHYTOALEXIN DEFICIENT 4, which are crucial components in SA biosynthesis and cell death regulation, mediate ceramide (especially long‐chain ceramide) metabolism and associated cell death by SA‐dependent and SA‐independent pathways.
Full text
Available for:
BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Celastrol, triptolide and triptonide are the most significant active ingredients of Tripterygium wilfordii Hook F (TWHF). In 2007, the ‘Cell’ journal ranked celastrol, triptolide, artemisinin, ...capsaicin and curcumin as the five natural drugs that can be developed into modern medicinal compounds. In this review, we collected relevant data from the Web of Science, PubMed and China Knowledge Resource Integrated databases. Some information was also acquired from government reports and conference papers. Celastrol, triptolide and triptonide have potent pharmacological activity and evident anti-cancer, anti-tumor, anti-obesity and anti-diabetes effects. Because these compounds have demonstrated unique therapeutic potential for acute and chronic inflammation, brain injury, vascular diseases, immune diseases, renal system diseases, bone diseases and cardiac diseases, they can be used as effective drugs in clinical practice in the future. However, celastrol, triptolide and triptonide have certain toxic effects on the liver, kidney, cholangiocyte heart, ear and reproductive system. These shortcomings limit their clinical application. Suitable combination therapy, new dosage forms and new routes of administration can effectively reduce toxicity and increase the effect. In recent years, the development of different targeted drug delivery formulations and administration routes of celastrol and triptolide to overcome their toxic effects and maximise their efficacy has become a major focus of research. However, in-depth investigation is required to elucidate the mechanisms of action of celastrol, triptolide and triptonide, and more clinical trials are required to assess the safety and clinical value of these compounds.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Environmental friendly aqueous‐processed solar cells have become one of the most promising candidates for the next‐generation photovoltaic devices. Researchers have made lots of progress in designing ...active materials with novel structures, manipulating the defects in active materials, optimizing device architecture, etc. However, it has long been a challenge to control the width of the depletion region and enhance carrier extraction ability. Fabrication of a thick bulk heterojunction (BHJ) film is an effective strategy to address these issues but difficult to realize. Herein, the thicker BHJ film of ZnO:CdTe is successfully fabricated and incorporated into CdTe‐poly(p‐phenylenevinylene) hybrid solar cells. As expected, this BHJ film enhances light absorption, extends the width of the depletion region, prolongs carrier lifetime, and promotes carrier extraction ability. Moreover, the electron transport layer of sol–gel ZnO with excellent transmittance and electrical conductivity boosts electron generation, transport, and injection, which further improves the device performance. As a result, the highest short current density (Jsc) of 19.5 mA cm−2, power conversion efficiency of 6.51%, and the widest depletion region (177 nm) are obtained in aqueous‐processed hybrid solar cells.
A thicker bulk heterojunction film is successfully fabricated leading to generation of more carriers, extendsion of depleted region width, prolonged carrier lifetime, and improved carrier extraction efficiency. The highest short current density of 19.5 mA cm−2, power conversion efficiency of 6.51% and the widest depletion region (177 nm) are obtained based on aqueous‐processed hybrid solar cells.
Full text
Available for:
FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Sn-based catalysts are recognized as prospective electrocatalysts to produce HCOOH due to their environmental friendliness, low cost, abundant reserves and selective *OCHO adsorption. However, most ...Sn-based catalysts usually suffer from low selectivity, catalytic activity and high overpotential. Recently, heterojunctions have aroused great attention for their superiority in exploiting the advantages of different catalysts, coordinating the electronic structure and decreasing the activation energy barrier for better stability and activity. Herein, ZnO/SnO2 was designed and prepared for highly selective CO2 reduction for HCOOH. A Faraday Efficiency (FE) of 93.8% and a yield of 0.16 mmol h−1 cm−2 were obtained at the potential of −1.05 V. Experimental evidence showed that the excellent catalytic performance was attributed to the heterojunctions, which optimized the electronic properties, enhanced the adsorption of CO2 or CO2·− and provided more active sites.
Breast cancer (BC) is the most prevalent malignant cancer in the world, is the leading cause of cancer‐related death female. Recently, there is accumulating evidence that long noncoding RNAs ...(lncRNAs) might as an important role in the progression of BC. (epithelial‐mesenchymal transition (EMT) is considered to play a vital role in tumor cells migration and invasion. Nevertheless, the entire biological mechanisms and functions of lncRNAs in tumor migration, invasion, and EMT remain uncertain. In the present research, we observed that the expression of lncRNA AC073284.4 was downregulated in BC paclitaxel‐resistant (PR) cells (MCF‐7/PR) and tissues. Bioinformatics analysis predicted that miR‐18b‐5p was a direct target of AC073284.4, which has been validated by dual‐luciferase reporter gene assay. We further proved that AC073284.4 could directly bind to miR‐18b‐5p and relieve the suppression for dedicator of cytokinesis protein 4 (DOCK4). Furthermore, the underlying functional experiments demonstrated that AC073284.4 might sponge miR‐18b‐5p to attenuate the invasion, metastasis, and EMT of BC cell through upregulating DOCK4 expression. In summary, AC073284.4 might serve as a competing endogenous RNA (ceRNA) in BC progression via modulating miR‐18b‐5p/DOCK4 axis, which weakens EMT and migration of BC. These results suggesting that AC073284.4 might function as a potential novel diagnostic biomarker in the progression of BC.
These findings provide a novel mechanism of the AC073284.4/miR‐18‐5p/DOCK4 axis in breast cancer, especially to explore its role in invasion, metastasis, and EMT, and suggest that this pathway might be a promising molecular therapeutic target against human breast cancer.
Full text
Available for:
BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Immune checkpoint blockade has vastly changed the landscape of cancer treatment and showed a promising prognosis for cancer patients. However, there is still a large portion of patients who have no ...response to this therapy. Therefore, it's essential to investigate biomarkers to predict the efficacy of immune checkpoint inhibitors. This article summarizes the predictive value of established biomarkers, including programmed cell death ligand 1(PD-L1) expression level, tumor mutational burden, tumor-infiltrating lymphocytes, and mismatch repair deficiency. It also addresses the predictive value of tumorous mutations, circulation factors, immune-related factors, and gut microbiome with immunotherapy treatment. Furthermore, some of the emerging novel biomarkers, and potential markers for hyper progressive disease are discussed, which should be validated in clinical trials in the future.
Diabetic retinopathy (DR) is the main cause of blindness in adults and investigating new therapeutic targets for DR is necessary. This study aimed to investigate the effect of high-mobility group box ...1 (HMGB1) protein and its mechanism in diabetic retinopathy (DR) were investigated.
Human retinal endothelial cells (HREC) were uesd for chip-seq. Sprague Dawley (SD) rats were randomly divided into control group, HMGB1 group, diabetes mellitus (DM) combined with HMGB1 siRNA group, and DM group. Next, eyeballs were removed and retinas were detached for western blot. The DM model of cell was built by increasing the glucose concentration in cell culture medium. The regulation of HMGB1 was achieved by short hairpin (sh)-HMGB1 transfection, then, the transfected cells were harvested for luciferase assay, western blot and qRT-PCR analyses as well as proliferation and apoptosis detection.
Chip-seq and luciferase assay showed the possible transcription factor functions of HMGB1 and IKB-α was one of the HMGB1 binding sites. In vivo and in vitro results indicated high expression of HMGB1 and NF-kB and low expression of IKB-α in DR and the expression of IKB-α and NF-kB was regulated by HMGB1. Moreover, cell assays showed that HMGB1 inhibited cell proliferation and promoted apoptosis.
The results from the present study showed that HMGB1 may be involved in the pathogenesis of DR as a transcription factor through NF-kB pathway. Therefore, blockade of HMGB1 may be a new method for the treatment of DR.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Coupling modes between surface plasmon polaritons (SPPs) and surface phonon polaritons (SPhPs) play a vital role in enhancing near-field thermal radiation but are relatively unexplored, and no ...experimental result is available. Here, we consider the NFTR enhancement between two identical graphene-covered SiO2 heterostructures with millimeter-scale surface area and report an experimentally record-breaking ∼64-fold enhancement compared to blackbody (BB) limit at a gap distance of 170 nm. The energy transmission coefficient and radiation spectra show that the physical mechanism behind the colossal enhancement is the coupling between the surface plasmon and phonon polaritons.
Full text
Available for:
IJS, KILJ, NUK, PNG, UL, UM
•Research trend in urban neighbourhood assessment based on street view image is identified.•Study method are mainly experiment and simulation.•Deep learning is the mainstream image processing method ...in this field.•Data analysis methods include numerical and spatial analysis.•Parameters and work flow are reviewed.
The urban neighbourhood is one of the most important places for public activities and behaviour spaces in cities, and the quantification of their environments is receiving increasing attention from researchers. In the era of big data, numerous urban data sources, represented by street view images, are documenting the evolution of people's lifestyles in various ways. With the rapid development of image processing technology, street view images have become an emerging data source for urban research. Street view image processing can be used to obtain spatial elements of large scale urban neighborhoods, thus enabling rapid urban neighbourhood evaluation. However, no systematic literature review has been conducted so far on the research of street view images application in urban neighbourhood environment. This paper systematically reviews the research trends of existing publications on the use of street view images for the quantitative analysis of urban neighbourhood environments. The number of publications began to grow rapidly in 2010. From 2010 to 2020, the number of publications increased from 6 to 341, with an annual growth rate of approximately 30.4%. Recent studies have focused on five areas: thermal environment, neighbourhood morphology, environmental perception, socio-economic factors, landscape design and environmental evaluation. The publications use experiment and simulation as the main research methods. Deep learning is the mainstream and advanced image processing method, and the data analysis models include numerical analysis and spatial analysis. Finally, the overall research framework and future research trends of street view images in the current quantitative research of urban streets are obtained.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
PDF
