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- 2018
- electromagnetic pulse
- cell proliferation
- cell membrane permeability
- cell response to electromagnetic stress
- apoptosis
- cancer therapy
- necrosis
- Intelligent Medical Engineering
- V.N. Karazin Kharkiv National University
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Orexin-A Suppresses Signal Transmission to Dopaminergic Amacrine Cells From Outer and Inner Retinal Photoreceptors
摘要： The neuropeptides orexin-A and orexin-B are widely expressed in the vertebrate retina; however, their role in visual function is unclear. This study investigates whether and how orexins modulate signal transmission to dopaminergic amacrine cells (DACs) from both outer retinal photoreceptors (rods and cones) and inner retinal photoreceptors (melanopsin-expressing intrinsically photosensitive retinal ganglion cells [ipRGCs]). A whole-cell voltage-clamp technique was used to record light-induced responses from genetically labeled DACs in ?at-mount mouse retinas. Rod and cone signaling to DACs was con?rmed pharmacologically (in wild-type retinas), whereas retrograde melanopsin signaling to DACs was isolated either pharmacologically (in wild-type retinas) or by genetic deletion of rod and cone function (in transgenic mice). Orexin-A attenuated rod/cone-mediated light responses in the majority of DACs and inhibited all DACs that exhibited melanopsin-based light responses, suggesting that exogenous orexin suppresses signal transmission from rods, cones, and ipRGCs to DACs. In addition, orexin receptor 1 antagonist SB334867 and orexin receptor 2 antagonist TCS OX229 enhanced melanopsin-based DAC responses, indicating that endogenous orexins inhibit signal transmission from ipRGCs to DACs. We further found that orexin-A inhibits melanopsin-based DAC responses via orexin receptors on DACs, whereas orexin-A may modulate signal transmission from rods and cones to DACs through activation of orexin receptors on DACs and their upstream neurons. Our results suggest that orexins could in?uence visual function via the dopaminergic system in the mammalian retina.
关键词： orexin,dopamine,ipRGC,melanopsin,amacrine cell,retina
更新于2025-09-09 09:28:46
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Prevalence and type of artefact with spectral domain optical coherence tomography macular ganglion cell imaging in glaucoma surveillance
摘要： Purpose The ganglion cell analysis (GCA) of the CIRRUSTM HD-OCT (Carl Zeiss, Meditec; Dublin, CA) provides measurement of the macular ganglion cell-inner plexiform layer (GCIPL) thickness. This study determined the frequency of scan artefacts and errors in GCIPL imaging in individuals undergoing HD-OCT surveillance for glaucoma. Method A total of 1439 eyes from 721 subjects enrolled in a prospective study assessing predictors of glaucoma progression underwent macular GCIPL imaging with the CIRRUS HD-OCT at recruitment. The prevalence of acquisition errors, segmentation errors, and co-morbid macular pathology was determined. Results A total of 87 (6.0%) of the 1439 scans had either acquisition errors, segmentation artefacts, or other macular pathology. The most common co-morbid macular pathology was epiretinal membrane in 2.2% of eyes. Conclusion The macular GCIPL scan was artefact free in 94% of eyes. However, epiretinal membrane and high myopia can cause scan artefact and should be considered when interpreting the results.
关键词： glaucoma,optical coherence tomography,ganglion cell analysis,scan artefacts,macular pathology
更新于2025-09-09 09:28:46
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BCAbox Algorithm Expands Capabilities of Raman Microscope for Single Organelles Assessment
摘要： Raman microspectroscopy is a rapidly developing technique, which has an unparalleled potential for in situ proteomics, lipidomics, and metabolomics, due to its remarkable capability to analyze the molecular composition of live cells and single cellular organelles. However, the scope of Raman spectroscopy for bio-applications is limited by a lack of software tools for express-analysis of biomolecular composition based on Raman spectra. In this study, we have developed the first software toolbox for immediate analysis of intracellular Raman spectra using a powerful biomolecular component analysis (BCA) algorithm. Our software could be easily integrated with commercial Raman spectroscopy instrumentation, and serve for precise analysis of molecular content in major cellular organelles, including nucleoli, endoplasmic reticulum, Golgi apparatus, and mitochondria of either live or fixed cells. The proposed software may be applied in broad directions of cell science, and serve for further advancement and standardization of Raman spectroscopy.
关键词： single cell assay,biomolecular analysis,Raman spectrometry,microscopy
更新于2025-09-09 09:28:46
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Accurate Extraction of Equivalent Circuit Parameters of Spiral Resonators for the Design of Metamaterials
摘要： Spiral resonators (SRs) are one of the most common typologies of resonant magnetic unit cell for the realization of metamaterials. The precise knowledge of their lumped electric properties (RLC parameters) is of crucial importance in the metamaterial design. Thus, an accurate and unambiguous procedure for estimating the value of the RLC lumped parameters of compact SRs is introduced. The proposed procedure relies on a rigorous approach allowing a complete characterization of SRs also in terms of Q-factor. The method is general and valid for other shapes of resonators. The estimations have been finally verified by performing measurements on fabricated SRs through a magnetic probe.
关键词： spiral resonators (SRs),scattering parameters,unit cell,Metamaterial,resonant frequency
更新于2025-09-09 09:28:46
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Vacuum evaporated FTO/(Cu, Ag)2ZnSnSe4 thin films and its electrochemical analysis
摘要： Cu2ZnSnSe4 and Ag2ZnSnSe4 thin films were deposited on FTO substrates by the thermal evaporation method and the films were then annealed at 300?C for 2 hrs. The XRD analysis confirms the formation of tetragonal structure for both CZTSe and AZTSe thin films. The introduction of Ag instead of Cu is confirmed by the major crystalline peak (112) shift towards lower angle 2θ=26.1? (for AZTSe). In the Raman spectra, the noticeable vibrations at 186 cm-1 and 183 cm-1 confirm the formation of CZTSe and AZTSe thin films. The Raman technique also found the presence of SnSe as a secondary phase. By comparing the optical spectra, the AZTSe film has higher absorption in the visible region than the CZTSe thin films which is attributed to the surface plasmon resonance of Ag. AFM images show a pyramidal structure for both CZTSe and AZTSe films. The Mott-Schottky plot shows p-type conductivity for FTO/CZTSe while there is n-type conductivity for a FTO/AZTSe thin film. The variation in the conductivity is due to replacing Cu with Ag. Photoelectrochemical cell (PEC) performance was employed in the presence of a polysulfide electrode by a standard three-electrode system. By comparing the value of Voc, the AZTSe film shows higher VOC than CZTSe films which is important for photovoltaic applications. The Photoconversion efficiency (PCE) is measured to be 0.31 % for FTO/AZTSe thin films, while it is low about 0.29% for FTO/CZTSe. The impedance plot shows the semicircular nature for both the FTO/CZTSe and FTO/AZTSe films.
关键词： Mott-schottky,Electrochemical Impedance,Cu2ZnSnSe4,Photoelectrochemical cell,Ag2ZnSnSe4
更新于2025-09-09 09:28:46
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DNA-Stabilized Silver Nanoclusters for Label-Free Fluorescence Imaging of Cell Surface Glycans and Fluorescence Guided Photothermal Therapy
摘要： A multifunctional nanoplatform that enables the integration of biological detection, imaging diagnosis, and synergistic therapy into a single nanostructure holds great promise for nanoscience and nanomedicine. Herein, a novel theranostic platform was presented for label-free imaging of cell surface glycans based on DNA/silver nanoclusters (AgNCs) via hybridization chain reaction (HCR) and fluorescence guided photothermal therapy (PTT). In this strategy, a dibenzocyclooctyne (DBCO)-functionalized DNA and two hairpin structures of DNA/AgNCs probes were involved. Following metabolic glycan labeling, the binding of DBCO-functionalized DNA to cell surface initiated HCR, and then cell surface glycans were specifically labeled by DNA/AgNCs fluorescent probes. Furthermore, this signal amplification strategy was adopted in quantitative analysis, and the detection limit could be achieved as low as 20 cells in 200 μL binding buffer. Moreover, the remarkable photothermal properties of DNA/AgNCs via HCR, led to efficient killing of cancer cell and inhibited the tumor growth under imaging guide. In this strategy, DNA/AgNCs were utilized to detect the cellular glycans, which aided in overcoming the high cost and instability of fluorescent dyes. Simultaneously, the HCR process avoided the introduction of excessive azido-sugars under the precondition of ensuring apparent fluorescence. These results indicated that the developed nanoplatform has great potential for specific cell surface glycans imaging and fluorescence guided PTT.
关键词： DNA-stabilized silver nanoclusters,fluorescence guided photothermal therapy,hybridization chain reaction,cell surface glycans,label-free fluorescence imaging
更新于2025-09-09 09:28:46
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Diagnostic accuracy of ex vivo fluorescence confocal microscopy for Mohs surgery of basal cell carcinomas: a prospective study on 753 margins
摘要： Background: Frozen histological sections are currently used for intra-operative margin assessment during Mohs surgery. Fluorescence confocal microscopy (FCM) is a new tool, which offers a promising and faster alternative to frozen histology. Objective: The aim of the present study is to prospectively evaluate in a clinical setting, the accuracy of FCM as compared to frozen sections in BCC’s margin assessment. Methods: Patients with BCC, scheduled for Mohs surgery were prospectively enrolled. Freshly-excised surgical specimens were first examined through FCM and then frozen sections were evaluated. Permanent sections were finally obtained, in order to validate our sample technique. A blind re-evaluation was also performed for discordant cases between FCM and frozen sections. Sensitivity and specificity levels, as well as positive and negative predicting values were calculated and ROC curves were generated. Results: We enrolled 127 BCCs in as many patients (40.2% females). A total number of 753 sections were examined. All BCCs were located on the head and neck area. When evaluating the performance of FCM as compared to frozen sections 79.8% sensitivity, 95.8% specificity, 80.5% positive predicting and 95.7% negative predicting values were found (Area Under the Curve: .88, 95%CI .84-.92; P<.001). A total of 49 discordant cases between FCM and frozen sections evaluations were blindly re-evaluated, of which 24 were false positive and 25 false negative. The performance of FCM and frozen sections was also evaluated according to the final histopathological assessment. Conclusions: We found high levels of accuracy for FCM as compared to frozen sections evaluation, in intra-operative BCC’s margin assessment during Mohs surgery. Some technical issues still prevent a wide use of this technique, but new upcoming devices promise to overcome these limitations.
关键词： basal cell carcinoma,fluorescence confocal microscopy,Mohs surgery,skin cancer,ex vivo confocal microscopy
更新于2025-09-09 09:28:46
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Changes in Ganglion Cell-Inner Plexiform Layer Thickness and Retinal Microvasculature in Hypertension: An OCT Angiography Study
摘要： Objective: To investigate retinal blood flow in patients with hypertension using optical coherence tomography angiography (OCTA) and the relationship between blood flow metrics and ganglion cell-inner plexiform layer (GC-IPL) thickness. Design: Retrospective, cross-sectional study. Methods: A total of 201 eyes from 117 healthy subjects and 84 hypertensive patients without any ocular abnormalities were included. Hypertensive patients were divided into the two groups according to disease periods (<5 years: hypertension group 1; ≥5 years: hypertension group 2). Macular 3 × 3 mm angiography was acquired using the Zeiss Cirrus 5000 OCT instrument. Vessel density (VD), perfusion density (PD), and foveal avascular zone metrics of the superficial capillary plexus were automatically calculated, and the thicknesses of the central fovea, GC-IPL, and peripapillary retinal nerve fiber layer (RNFL) were measured. All measurements were compared among the three groups, and retinal blood flow metrics were correlated with the thickness of each retinal layer. Logistic regression analyses were performed to determine the factors associated with prolonged hypertension. Results: The average GC-IPL (p<0.001) and peripapillary RNFL (p=0.048) thicknesses in hypertension group 2 were significantly thinner compared to the control group. The 3 mm total area of the VD and PD was also decreased compared to the control group and hypertension group 1 (all p<0.05), and was significantly correlated with the GC-IPL (VD: r=0.450, p=0.001; PD: r=0.467, p<0.001) and peripapillary RNFL (VD: r=0.314, p=0.027; PD: r=0.328, p=0.023) thicknesses in hypertension group 2. Using multivariate logistic analyses, only the average GC-IPL thickness was a significant factor for prolonged hypertension (odds ratio=0.911, p=0.002). Conclusions: In patients with hypertension lasting more than 5 years, inner retinal layer thinning, particularly GC-IPL thinning, was observed, which was significantly correlated with a decrease in retinal blood flow. Therefore, physicians should consider the effects of hypertension on the GC-IPL.
关键词： hypertension,retinal microcirculation,optical coherence tomography angiography,ganglion cell-inner plexiform layer
更新于2025-09-09 09:28:46
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A novel colorimetric and ratiometric fluorescent probe for selective detection of bisulfite in real samples and living cells
摘要： An abnormal level of bisulfite can induce toxicological effects associated with lung cancer, cardiovascular and neurological disorders. Therefore, it is of significance to develop an effective fluorescent probe to detect bisulfite in living cells. Herein, a novel fluorescent probe QPCT, based on a 1,4-addition mechanism, was constructed for the colorimetric and ratiometric detection of bisulfite. QPCT displayed high selectivity and anti-interference ability to bisulfite over other anions and biothiols. The probe renders a sensitive ratiometric response to bisulfite with a remarkable fluorescence blue shift from 590 to 537 nm and the fluorescence ratio was linear with bisulfite concentration over the range of 0-120 μM. More importantly, QPCT has been successfully applied to detect bisulfite in sugars and living A549 cells, which indicated that QPCT had a great capability for monitoring bisulfite in complex systems.
关键词： Real samples,Fluorescent probe,Live-cell imaging,Bisulfite,Colorimetric and ratiometric
更新于2025-09-09 09:28:46
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Ultra-short Echo Time Imaging with Multiple Echo Refocusing for Porous Media T2 Mapping
摘要： T2 relaxation time measurement is a powerful tool to distinguish signal components in porous media. As T2 weighting is generally achieved by spin-echo based methods, it is very challenging to capture very short T2 relaxation time components, approximately 1 ms, with high resolution spatial encoding. It is especially challenging when T2 relaxation times of the other signal components are not known a priori. We propose a method, combining ultrashort echo time (UTE) imaging with multiple spin echo refocusing, to generate a series of images with T2 weighting. The T2 decay curves for each image voxel were extracted, and multiple T2 relaxation components were quantitatively evaluated. The method has been applied to a fast relaxation system, namely, moisture content in wood samples to differentiate cell wall (bound) water and cell cavity (lumen) water.
关键词： cell wall water,spin echo,wood,T2 mapping,lumen water,k-space,radial,UTE
更新于2025-09-09 09:28:46