Atomic Precision Graphene Model Compound for Bright Electrochemiluminescence and Organic Light-Emitting Diodes

An N-annulated perylene diimide dimer, tPDI₂N-hex, a graphene model compound with atomic precision, was investigated for luminescence applications. Electrochemiluminescence (ECL) of tPDI₂N-hex was studied with tri-n-propylamine (TPrA) as a reducing coreactant. ECL-voltage curves along with spooling ECL spectra provided details of light generation mechanisms. The relative ECL quantum efficiency of the Ru(bpy)₃(PF₆)₂/TPrA system was calculated to be 64%, which is superior to that of many other organic molecules because of the desired excited state in the absence of surface states. An organic light-emitting diode (OLED) fabricated with tPDI₂N-hex displayed bright orange-red emission with a low color temperature, which is very desirable. It is plausible that the sterically constrained and thus orthogonal aromatic moieties in the tPDI₂N-hex structure, with atomic precision graphene layer characteristics, lead to the excellent luminescence performances. The ECL and OLED studies of tPDI₂N-hex showcase great application potentials of tPDI₂N-hex in both solution-based ECL probes and solid-state light devices.

A Perspective on Application of Carbon Quantum Dots in Luminescence Immunoassays

Quantum dots (QDs) have been established in our daily life, for instance, in display screens and light-harvesting technologies, mainly owing to their peculiar opto-electronic features. However, toxicity of inorganic QDs, such as CdSe, CdTe, and perovskites, limits their applications in biological environments for medical diagnosis and bio-imaging purposes. A new generation of QDs called carbon quantum dots (CQDs) have been progressing rapidly over the past few years. CQDs have become as popular as other carbon-based nanomaterials such as carbon nanotubes (CNTs), due to their ease of preparation, ultra-small size, biocompatibility, and bright luminescence.

Electrogenerated Chemiluminescence and Electroluminescence of N-Doped Graphene Quantum Dots Fabricated from an Electrochemical Exfoliation Process in Nitrogen-Containing Electrolytes

Artificial lighting sources are one of the most important technological developments for our modern lives; the search for cost-effective and efficient luminophores is therefore crucial to a sustainable future. Graphene quantum dots (GQDs) are carbon-based nanomaterials that exhibit exceptional optical and electronic properties, making them a prime candidate for a luminophore in a light-emitting device. Nitrogen-doped GQDs fabricated from a facile top-down electrochemical exfoliation process with a nitrogen-containing electrolyte in this report showed strong photoluminescent emission at 450 nm, and electrogenerated chemiluminescence at 660 nm in the presence of benzoyl peroxide as a coreactant. When introduced into solid-state light-emitting electrochemical cells, for the first time, the GQDs displayed a broad white emission centered at 610 nm, corresponding to Commision Internationale de l'eclairage (CIE) colour coordinates of (0.38, 0.36).

Efficient White Electrochemiluminescent Emission From Carbon Quantum Dot Films

Carbon quantum dots (CQDs) were manufactured from citric acid and urea in a gram-scale synthesis with a controlled size range between 1. 5 and 23.8 nm. The size control was realized by varying volume of the precursor solution in a hydrothermal synthesis method. The prepared CQDs were investigated using electrochemiluminescence (ECL) spectroscopy at interfaces of their electrode films and electrolyte solution containing coreactants rather than conventional optoelectronic tests, providing an in-depth analysis of light-emission mechanisms of the so-called half-cells. ECL from the CQD films with TPrA and K2S2O8 as coreactants provided information on the stability of the CQD radicals in the films. It was discovered that CQD•- has a powerful electron donating nature to sulfate radical to generate ECL at a relative efficiency of 96% to the Ru(bpy)3Cl2/K2S2O8 coreactant system, indicating a strong performance in light emitting applications. The smaller the CQD particle sizes, the higher the ECL efficiency of the film interface, most likely due to the increased presence of surface states per mass of CQDs. Spooling ECL spectroscopy of the system revealed a potential-dependent light emission starting from a deep red color to blue-shifted intensity maximum, cool bright white emission with a correlated color temperature of 3,200 K. This color temperature is appropriate for most indoor lighting applications. The above ECL results provide information on the performance of CQD light emitters in films, permitting preliminary screening for light emitting candidates in optoelectronic applications. This screening has revealed CQD films as a powerful and cost-effective light emitting layer toward lighting devices for indoor applications.

Hsa_circ_0005075 predicts a poor prognosis and acts as an oncogene in colorectal cancer via activating Wnt/β-catenin pathway

OBJECTIVE

Emerging evidence has demonstrated vital regulation of circular RNAs (circRNAs) on tumorigenesis and progression of tumors. Abnormally expressed circRNAs hsa_circ_0005075 (circ_0005075) has been reported in several tumors. In this study, we aimed to explore the expression profiles, prognostic value, and potential function of circ_0005075 in colorectal cancer (CRC) PATIENTS AND METHODS: RT-PCR was used to detect the expression of circ_0005075 in both CRC tissues and cell lines. The associations between circ_0005075 expression and clinicopathological features and clinical prognosis were statistically analyzed. The effects of circ_0005075 on CRC cells were evaluated by Cell Counting Kit-8 (CCK-8), colony formation assays, Flow cytometer, and transwell assays. Western blot was performed to explore whether circ_0005075 modulated the Wnt/β-catenin pathway.

RESULTS

We observed that circ_0005075 expression was significantly up-regulated in both CRC tissues and cell lines. Then, clinical assays indicated that high circ_0005075 expression was significantly associated with histology/differentiation, depth of invasion, advanced TNM stage, and shorter overall survival and disease-free survival of CRC patients. Cellular studies indicated that circ_0005075 can enhance the proliferation, migration, and invasion capacities of CRC cells, thereby promoting tumor progression. Further mechanistic investigation showed that circ_0005075 displayed its tumor-promotive roles through activating Wnt/β-catenin pathway.

CONCLUSIONS

Our present data revealed circ_0005075 as a potential molecular marker and target for the prognosis and treatment of CRC patients.

Benzosiloles with Crystallization-Induced Emission Enhancement of Electrochemiluminescence: Synthesis, Electrochemistry, and Crystallography

Crystallization-induced emission enhancement (CIEE) was demonstrated for the first time for electrochemilunimescence (ECL) with two new benzosiloles. Compared with their solution, the films of the two benzosiloles gave CIEE of 24 and 16 times. The mechanism of the CIEE-ECL was examined by spooling ECL spectroscopy, X-ray crystal structure analysis, photoluminescence, and DFT calculations. This CIEE-ECL system is a complement to the well-established aggregation-induced emission enhancement (AIEE) systems. Unique intermolecular interactions are noted in the crystalline chromophore. The first heterogeneous ECL system is established for organic compounds with highly hydrophobic properties.

Comparison of contrast-enhanced ultrasound and contrast-enhanced computed tomography for the diagnosis of cervical lymph node metastasis in squamous cell carcinoma of the oral cavity

Early detection of cervical lymph node metastasis (CLNM) from squamous cell carcinoma (SCC) of the oral cavity remains challenging. This prospective study was performed to evaluate the ability of contrast-enhanced ultrasound (CEUS) to detect CLNM from oral cavity SCC. Additionally, its diagnostic value was compared with that of contrast-enhanced computed tomography (CECT). Forty-eight consecutive patients with SCC of the oral cavity were enrolled. All subjects were examined preoperatively with both CEUS and CECT. Subsequently, neck dissections were performed for these patients, and cervical lymph nodes separated from the surgical specimens were assessed histologically. The diagnostic performance of these two examinations was compared based on the results of histopathology. The sensitivity, specificity, accuracy, positive predictive value, negative predictive value, and Youden index for CEUS and CECT were 69.39% vs. 44.90%, 94.71% vs. 97.12%, 89.88%% vs. 87.16%, 75.56% vs. 78.57%, 92.92% vs. 88.21%, and 64.10% vs. 42.02%, respectively. A significant difference was observed in terms of sensitivity (P=0.024) and Youden index (rate difference 22.08%, 95% confidence interval 2.72-41.44%). Therefore, CEUS appears to be a promising diagnostic tool that is superior to CECT for detecting CLNM from SCC of the oral cavity, with a higher sensitivity.

Sex modulates the apolipoprotein E ε4 effect on white matter and cortical functional connectivity in individuals with amnestic mild cognitive impairment

BACKGROUND AND PURPOSE

Recent studies from the Alzheimer's Disease Neuroimaging Initiative show that, in the USA, 75% of patients with Alzheimer's disease are female. To date, there have rarely been any attempts to analyze data by sex or gender, which limits the potential for discovering the effects of sex or gender on disease. Little evidence is available regarding the effect of gender and apolipoprotein E (APOE) ε4 on white matter (WM) connection from the functional perspective due to the lack of appropriate techniques for detecting blood-oxygen-level-dependent signals in WM.

METHODS

We took advantage of a new framework known as functional tensor imaging to investigate the effect of sex and APOEε4 on WM cortical functional connectivity throughout the brain.

RESULTS

In a group of female patients with amnestic mild cognitive impairment, we found a significantly reduced functional connectivity in the left posterior limb of the internal capsule, left superior fronto-occipital fasciculus, bilateral temporopolar area and right somatosensory association cortex in APOEε4 carriers in contrast to non-carriers. We also found a significant APOEε4 by sex interaction effect on the right somatosensory association cortex, left temporopolar area and left superior temporal gyrus. The clinical Montreal Cognitive Assessment score was significantly negatively associated with the right somatosensory association cortex with APOEε4 by sex interaction in males.

CONCLUSIONS

These results indicate that increased APOE-related risk in women may be associated with decreased activity in both gray matter and WM in patients with amnestic mild cognitive impairment compared with men. The finding suggests accounting for sex differences in neuroimaging biomarkers, diagnostics and treatment strategy.

MiR-203 over-expression promotes prostate cancer cell apoptosis and reduces ADM resistance

The article "MiR-203 over-expression promotes prostate cancer cell apoptosis and reduces ADM resistance, by Chen LZ, Ding Z, Zhang Y, He ST, Wang XH, published in Eur Rev Med Pharmacol Sci. 2018 Jun;22(12):3734-3741. DOI: 10.26355/eurrev_201806_15253. PMID: 29949147" has been withdrawn from the authors. The Publisher apologizes for any inconvenience this may cause.

MiR-203 over-expression promotes prostate cancer cell apoptosis and reduces ADM resistance

OBJECTIVE

Extra-cellular signal regulated kinase (ERK)/mitogen activated protein kinase (MAPK) signaling pathway is widely involved in cell proliferation, apoptosis, and drug resistance. MAPK kinase 1 (MEK1) is the upstream protein kinase of ERK that can activate ERK/MAPK signaling pathway. microRNA 203 (MiR-203) down-regulation is found to be associated with prostate cancer pathogenesis. Bioinformatics analysis showed the complementary targeted relationship between miR-203 and the 3'-UTR of MEK1 mRNA. This study explored the role of miR-203 in regulating prostate cancer cell proliferation, apoptosis, and ADM resistance through affecting MEK1 expression.

MATERIALS AND METHODS

Dual luciferase assay confirmed the targeted relationship between miR-203 and MEK1. MiR-203, MEK1, p-ERK1/2, and B cell lymphoma 2 (Bcl-2) expressions were compared in normal prostate epithelial cells PrEC, prostate cancer cells PC-3M, and drug resistance cells PC-3M/ADM. PC-3M, PC-3M/ADM cell apoptosis and proliferation were detected by using flow cytometry under ADM treatment at IC50 concentration of PC-3M cells. PC-3M cells were cultured in vitro and divided into four groups, including microRNA-normal control (miR-NC), miR-203 mimic, small interfere NC (si-NC), and si-MEK1.

RESULTS

MiR-203 targeted and inhibited MEK1 expression. MiR-203 levels and cell apoptosis were significantly lower, while MEK1, p-ERK1/2, Bcl-2, and cell proliferation were significantly higher in PC-3M/ADM cells compared to the PC-3M cells. MiR-203 mimic and/or si-MEK1 transfection significantly reduced MEK1, p-ERK1/2, and Bcl-2 levels, attenuated cell proliferation, induced cell apoptosis, and decreased drug resistance.

CONCLUSIONS

MiR-203 elevation suppressed prostate cancer PC-3M cell proliferation, promoted apoptosis, and weakened ADM resistance through targeted inhibiting MEK1 expression to alleviate ERK/MAPK signaling pathway and Bcl-2 expression.

Different responses of avian feeding guilds to spatial and environmental factors across an elevation gradient in the central Himalaya

Although elevational patterns of species richness have been well documented, how the drivers of richness gradients vary across ecological guilds has rarely been reported. Here, we examined the effects of spatial factors (area and mid-domain effect; MDE) and environmental factors, including metrics of climate, productivity, and plant species richness on the richness of breeding birds across different ecological guilds defined by diet and foraging strategy. We surveyed 12 elevation bands at intervals of 300 m between 1,800 and 5,400 m a.s.l using line-transect methods throughout the wet season in the central Himalaya, China. Multiple regression models and hierarchical partitioning were used to assess the relative importance of spatial and environmental factors on overall bird richness and guild richness (i.e., the richness of species within each guild). Our results showed that richness for all birds and most guilds displayed hump-shaped elevational trends, which peaked at an elevation of 3,300-3,600 m, although richness of ground-feeding birds peaked at a higher elevation band (4,200-4,500 m). The Normalized Difference Vegetation Index (NDVI)-an index of primary productivity-and habitat heterogeneity were important factors in explaining overall bird richness as well as that of insectivores and omnivores, with geometric constraints (i.e., the MDE) of secondary importance. Granivore richness was not related to primary production but rather to open habitats (granivores were negatively influenced by habitat heterogeneity), where seeds might be abundant. Our findings provide direct evidence that the richness-environment relationship is often guild-specific. Taken together, our study highlights the importance of considering how the effects of environmental and spatial factors on patterns of species richness may differ across ecological guilds, potentially leading to a deeper understanding of elevational diversity gradients and their implications for biodiversity conservation.

Observation of second sound in graphite at temperatures above 100 K

Wavelike thermal transport in solids, referred to as second sound, is an exotic phenomenon previously limited to a handful of materials at low temperatures. The rare occurrence of this effect restricted its scientific and practical importance. We directly observed second sound in graphite at temperatures above 100 kelvins by using time-resolved optical measurements of thermal transport on the micrometer-length scale. Our experimental results are in qualitative agreement with ab initio calculations that predict wavelike phonon hydrodynamics. We believe that these results potentially indicate an important role of second sound in microscale transient heat transport in two-dimensional and layered materials in a wide temperature range.

Imaging features of metanephric adenoma and their pathological correlation

AIM

To analyse the imaging features of metanephric adenoma (MA) and their pathological correlation.

MATERIALS AND METHODS

The imaging findings in 11 patients with MA were studied retrospectively. Ultrasonography (US), computed tomography (CT), and magnetic resonance imaging (MRI) findings were studied in seven, 11, and six patients, respectively. The enhancement pattern, attenuation, lesion location, size, cystic or solid appearance, capsule sign, and presence of calcifications were evaluated.

RESULTS

On ultrasonography, MA presented as hypoechoic (4/7), slightly hyperechoic (1/7), isoechoic (2/7), and with a clear boundary. Unenhanced CT showed unclear boundaries (11/11), homogeneous isodensity (8/11), with calcification (1/11), necrosis (1/11), and heterogeneous hyperattenuation (1/11). Mean CT attenuation values on unenhanced and enhanced CT (cortical phase, corticomedullary phase, and excretory phase) were 38.87±6.66, 55.71±17.74, 67.77±16.86, and 65.62±15.99 HU, respectively. The degree of enhancement of the lesions in each phase was statistically significantly lower than that of the surrounding normal renal parenchyma (p=0.00). The pattern of enhancement of the solid component was slight and gradual enhancement (9/11). The tumour was located entirely within the renal medulla in nine cases, and two cases demonstrated an exophytic pattern. All tumours showed a clear boundary on enhanced CT, but capsules were not found. The mean greatest tumour diameter was 3.5 cm. MA showed markedly hyperintense on the diffusion-weighted MRI sequence (DWI) and delayed enhancement of the tumour capsule on enhanced MRI.

CONCLUSIONS

Imaging features of MA are usually solid and hypovascular, and show prolonged, and homogeneous mild enhancement that is less than that of the surrounding normal renal parenchyma in all phases. MA is markedly hyperintense on DWI.

Correlating Live Cell Viability with Membrane Permeability Disruption Induced by Trivalent Chromium

Cr(III) is often regarded as a trace essential micronutrient that can be found in many dietary supplements due to its participation in blood glucose regulation. However, increased levels of exposure have been linked to adverse health effects in living organisms. Herein, scanning electrochemical microscopy (SECM) was used to detect variation in membrane permeability of single cells (T24) resulting from exposure to a trivalent Cr-salt, CrCl₃. By employing electrochemical mediators, ferrocenemethanol (FcMeOH) and ferrocenecarboxylic acid (FcCOO^-), initially semipermeable and impermeable, respectively, complementary information was obtained. Three-dimensional COMSOL finite element analysis simulations were successfully used to quantify the permeability coefficients of each mediator by matching experimental and simulated results. Depending on the concentration of Cr(III) administered, three regions of membrane response were detected. Following exposure to low concentrations (up to 500 μM Cr(III)), their permeability coefficients were comparable to that of control cells, 80 μm/s for FcMeOH and 0 μm/s for FcCOO^-. This was confirmed for both mediators. As the incubation concentrations were increased, the ability of FcMeOH to permeate the membrane decreased to a minimum of 17 μm/s at 7500 μM Cr(III), while FcCOO^- remained impermeable. At the highest examined concentrations, both mediators were found to demonstrate increased membrane permeability. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide cell viability studies were also conducted on Cr(III)-treated T24 cells to correlate the SECM findings with the toxicity effects of the metal. The viability experiments revealed a similar concentration-dependent trend to the SECM cell membrane permeability study.

Physcion 8-O-β-glucopyranoside prevents hypoxia-induced epithelial-mesenchymal transition in colorectal cancer HCT116 cells by modulating EMMPRIN

Epithelial-mesenchymal transition (EMT) is considered as the most important mechanism that underlies the initiation of cancer metastasis. Here we report that Physicon 8-O-β-glucopyranoside (PG), a major active ingredient from a traditional Chinese herbal medicine Rumex japonicus Houtt, is capable of preventing human colorectal cancer cells from hypoxia-induced EMT. The treatment of the cells with PG reversed the EMT-related phenotype that has the morphological changes, down-regulation of E-cadherin, and hypoxia-induced cell migration and invasion. The effect was mediated at least in part by inhibiting the mRNA and protein expressions of EMMPRIN via modulation of PTEN/Akt/HIF-1α pathway. In addition, we found that PG-mediated prevention of EMT involved blockade of the hypoxia-induced up-regulation of Snail, Slug and Twist. In summary, this study showed that PG can prevent EMT induced by hypoxia, the environment that commonly exists in the center of a solid tumor. Given the low toxicity of PG to the healthy tissues, our study suggests that PG can serve as a safe therapeutic agent for suppressing cancer metastasis.