Spooling electrochemiluminescence spectroscopy: development, applications and beyond

One of the most widely used techniques to generate light through an efficient electron transfer is called electrochemiluminescence, or electrogenerated chemiluminescence (ECL). ECL mechanisms can be explored via 'spooling spectroscopy' in which individual ECL spectra showing emitted light are collected continuously during a potentiodynamic course. The obtained spectra are spooled together and plotted along the applied potential axis; because the potential sweep occurs at a defined rate, this axis is directly proportional to time. Any changes in the emission spectra can be correlated to the corresponding potentials and/or times, leading to a deeper understanding of the mechanism for light generation-information that can be used for efficiently maximizing ECL intensities. The formation of intermediates and excited states can also be tracked, which is crucial to interrogating and drawing electron transfer pathways (i.e., understanding the chemical reaction mechanism). Spooling spectroscopy is not limited to ECL; we also include instructions for the use of related methodologies, such as spooling photoluminescence spectroscopy during an electrolysis procedure, which can be easily set up. The total time required to complete the protocol is ~49 h, from making electrodes and an ECL cell, fabricating light-tight housing, to setting up instruments. Preparing the lab for an individual experiment (making an electrolyte solution of a targeted luminophore, cooling down the CCD camera, calibrating the spectrometer and surveying electrochemistry) takes ~1 h 15 min, and performing the spooling ECL spectroscopy experiment itself requires ~10 min.

A184 INCIDENCE OF VENOUS THROMBOTIC EVENTS AND RISK FACTORS IN CHILDREN HOSPITALIZED WITH INFLAMMATORY BOWEL DISEASE: A RETROSPECTIVE, CASE-CONTROL STUDY

Background

Limited research has been published to describe the incidence of venous thromboembolism (VTE) and relevant risk factors in Canadian children with inflammatory bowel disease (IBD).

Aims

The present study aimed to investigate the incidence of VTE amongst hospitalized pediatric IBD patients over a 10-year period and identify risk factors for the development of VTE.

Methods

A retrospective, matched case-control study was performed at McMaster Children’s Hospital. Hospitalized pediatric patients with IBD (<18 years old) from September 2009 to August 2020 were selected. Inpatient data was extracted from the medical record database, including baseline demographic data, thromboembolic events and potential risk factors for VTE.

Results

There were 890 hospitalizations of IBD patients during the study period. 15 (1.69%) were diagnosed with a VTE, including 4 males and 11 females (mean age 13.4±2.9 years old). 12 ulcerative colitis (UC) (80%) and 3 Crohn’s disease (CD) (20%) hospitalizations were comprised in the VTE group. There was a significant difference in VTE rate between females (2.7%) and males (0.8%) (P = 0.03). The VTE rate in the UC group (4.2%) was significantly higher than in the CD group (0.6%) (P = 0.001). The incidence of VTE amongst hospitalized IBD patients did not vary over the 10-year period (P = 0.496). Length of stay in hospital, albumin level and central venous catheter were shown to be significantly different, although they were not identified as independent risk factors (P >0 .05). Of the 15 hospitalizations with VTE, 6/15 (40%) were superficial VTEs in the extremities and 9/15 (60%) had a deep vein thrombosis (DVT) including 6 in the extremities and 3 in the abdomen. VTEs were associated with a peripheral line in 7 patients and with a PICC line in 4 hospitalizations. 2 of 9 (22%) with extremity DVT developed symptomatic pulmonary embolism. An inherited thrombotic condition was identified in 2 of 15 with VTEs. 12/15 (80%) with VTEs were symptomatic and all VTE related symptoms happened in patients with extremity thrombosis and pulmonary embolism. 7 of 15 (47%) VTEs were treated with anticoagulation therapy for 1–6 months. VTE related symptoms and repeat imaging tests significantly improved, and no patient developed a bleeding complication as a result of treatment.

Conclusions

The VTE rate in pediatric IBD patients was relatively low at McMaster Children’s hospital. Children with VTE were disproportionately females with ulcerative colitis compared with children with no VTE. Central venous line insertion may be correlated with the risk for VTE in children with IBD. Most VTEs and related symptoms happened in patients with extremity thrombosis and secondary pulmonary embolus. Anticoagulation therapy in children with IBD with active disease appears to be safe.

Funding Agencies

Kids Dig Health Funding from McMaster Children’s Hospital, McMaster University

Supplemental iodine-containing prenatal multivitamins use and the potential effects on pregnancy outcomes in a mildly iodine-deficient region

PURPOSE

The use and contribution of prenatal multivitamins (PMV) as iodine source for pregnant women in China, especially in mildly iodine-deficient region, have not been well studied. This study aimed to explore the association between PMV intake during pregnancy and thyroid function in mothers and newborns.

METHODS

We performed a study involving women with a history of taking PMV during pregnancy between January 2013 and October 2015, in Shanghai, a mildly iodine-deficient region. Maternal thyroid function in early and late pregnancy, and neonatal TSH on postnatal d 3 were obtained from medical records. We compared the outcomes in pregnant women who took exclusively iodine-containing PMV (I + PMV) with those who took exclusively non-contained PMV (I- PMV). Propensity score matching (PSM) was used to identify women with similar baseline characteristics.

RESULTS

After PSM, 1280 women in I + PMV and 2560 in I- PMV had similar propensity scores and were included in the analyses. Introduction of I + PMV to women was associated with slightly higher maternal thyroid hormone production (higher maternal FT4, p = 0.01, non-significantly lower TSH, p = 0.79) and lower neonatal TSH levels (p < 0.0001). The frequency of adverse pregnancy outcomes or thyroid dysfunctions did not differ between groups in late pregnancy. Mothers received I + PMV (0.2 SD) had a stronger association of maternal TSH with neonatal TSH than those who received I- PMV (0.1 SD). These effects were only shown in TPOAb-negative mothers, not in TPOAb-positive mothers.

CONCLUSION

TPOAb-positive women display an impaired iodine transport in thyroid and placenta, and this may explain the lack of changes in maternal and neonatal thyroid parameters with I + PMV supplementation in these women. This phenomenon might suggest that these women require different iodine doses or treatment approach in comparison with TPOAb-negative women.

[Consistency of effective orifice area of prosthetic mitral valve estimated using 2-dimensional and 3-dimensional transesophageal echocardiography]

OBJECTIVE

To analyze the consistency of effective orifice area (EOA) of prosthetic mitral valve estimated using 2- dimensional (2D) and 3-dimensional (3D) transesophageal echocardiography (TEE).

OBJECTIVE

This study was conducted among 34 patients undergoing mitral valve replacement surgery in Nanjing First Hospital between March and June in 2019. The diameter of the left ventricular outflow tract (LVOT) measured by 2D-TEE was used to calculate the cross sectional area of LVOT (CSALVOT). In 3D-TEE method, LVOT area was measured directly by planimetry on an enface view. The EOAs of the prosthetic mitral valve were calculated for both methods using the continuity equation. Bland-Altman plot consistency test was used to analyze the consistency between the two sets of EOA results, and linear regression analysis was used to analyze their correlation.

OBJECTIVE

The EOA of the prosthetic mitral valve differed significantly between 2D method and 3D method (2.22±0.71 cm² vs 2.35±0.70 cm², P < 0.001) with a mean difference of -0.14±0.20 cm² and 95% coherence boundaries of (-0.53, 0.25 cm²). The regression equation for EOA-3D and EOA-2D is y=0.27 + 0.94x, showing a good correlation between the two methods.

OBJECTIVE

EOA estimation of the prosthetic mitral valve using 2D and 3D TEE has a good consistency, and the results estimated by the 2D method are slightly lower by about 6% than those by the 3D method.

Electrochemiluminescence and Photoluminescence of Carbon Quantum Dots Controlled by Aggregation-Induced Emission, Aggregation-Caused Quenching, and Interfacial Reactions

Carbon quantum dots (CQDs) show promise in optoelectronics as a light emitter due to simple synthesis, biocompatibility and strong tunable light emissions. However, CQDs commonly suffer from aggregation caused quenching (ACQ), inhibiting the full potential of these light emitters. Studies into different ideal light emitters have shown enhancements when converting common ACQ effects to aggregation induced emission (AIE) effects. We report CQD synthesis using citric acid and high/low thiourea concentrations, or sample 2/1. These two CQDs exhibited AIE and ACQ PL effects, respectively. CQD characterizations and photoluminescence interrogations of CQD films and solutions revealed that these unique emission mechanisms likely arose from different S incorporations into the CQDs. Furthermore, it was discovered that sample 2 emitted electrochemiluminescence (ECL) more intensely than sample 1 in a homogenous solution with S₂O₈^2- as a coreactant, due to aggregation and interactions of CQD species in solution. Very interestingly, sample 1's CQD film|S₂O₈^2- system achieved an ECL efficiency of 26% and emitted roughly 26 times more efficiently than sample 2 in the same conditions. Predominant interfacial reactions and surface state emission produced intense white light with a correlated color temperature of 2000 K. Spooling ECL spectroscopy was utilized to investigate emission mechanisms. Sample 2's CQD film|TPrA system had four times higher ECL intensity than that of sample 1, most likely due to π-cation interactions leading to a strong CQD^•+ stability, thereby, enhancing ECL. It is anticipated that ECL enhancement of CQD films or solutions by means of AIE will lead to wide CQD optoelectronic applications.

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.