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Structural and Functional Outcomes in Chronic Central Serous Chorioretinopathy Treated with Photodynamic Therapy
摘要： Purpose: To study the retinal pigment epithelium (RPE) and retinal alterations in chronic central serous chorioretinopathy treated with photodynamic therapy, and its correlation with functional parameters such as best-corrected visual acuity (BCVA) and contrast sensitivity (CS). Methods: Retrospective, noncomparative, consecutive evaluation by optical coherence tomography and its correlation with BCVA and CS in 31 eyes of 26 patients. Results: In all affected patients, 88.5% were male with a mean age of 42.9 years. The right eye was involved in 64.5% of cases, bilateral in 19% and 73.9% were hyperopic (spherical refraction between 0 and +5.0 diopters). Of these cases, 51.5% had peri-RPE abnormalities, 17.3% hyperreflective substances at RPE, 19.4% RPE atrophy, 55.3% foveolar atrophy, 3.1% pigment epithelial detachment, 5.2% subretinal fluid persistence, 8.3% fibrin deposits, 68.4% photoreceptor inner and outer segment line interruption and 31.1% external limiting membrane interruption. Conclusions: Time evolution and number of outbreaks were related to the decrease in foveal and chorodial thickness and in those with worse BCVA and CS. RPE abnormalities and atrophy were related to the age of onset of symptoms. Photoreceptor elongation has been correlated with poor BCVA and inner and outer segment line destructuring and interruption with poor CS.
关键词： Photochemotherapy,Contrast sensitivity,Visual acuity,Central serous chorioretinopathy,Optical coherence tomography
更新于2025-09-23 15:22:29
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Enlargement of Gold Nanoparticles for Sensitive Immunochromatographic Diagnostics of Potato Brown Rot
摘要： Lateral ?ow immunoassay (LFIA) is a convenient tool for rapid ?eld-based control of various bacterial targets. However, for many applications, the detection limits obtained by LFIA are not suf?cient. In this paper, we propose enlarging gold nanoparticles’ (GNPs) size to develop a sensitive lateral ?ow immunoassay to detect Ralstonia solanacearum. This bacterium is a quarantine organism that causes potato brown rot. We fabricated lateral ?ow test strips using gold nanoparticles (17.4 ± 1.0 nm) as a label and their conjugates with antibodies speci?c to R. solanacearum. We proposed a signal enhancement in the test strips’ test zone due to the tetrachloroauric (III) anion reduction on the GNP surface, and the increase in size of the gold nanoparticles on the test strips was approximately up to 100 nm, as con?rmed by scanning electron microscopy. Overall, the gold enhancement approach decreased the detection limit of R. solanacearum by 33 times, to as low as 3 × 104 cells·mL–1 in the potato tuber extract. The achieved detection limit allows the diagnosis of latent infection in potato tubers. The developed approach based on gold enhancement does not complicate analyses and requires only 3 min. The developed assay together with the sample preparation and gold enlargement requires 15 min. Thus, the developed approach is promising for the development of lateral ?ow test strips and their subsequent introduction into diagnostic practice.
关键词： gold nanoparticles,immunochromatographic diagnostics,potato brown rot,gold particle growth,increase of sensitivity,lateral ?ow immunoassay,test strips,Ralstonia solanacearum
更新于2025-09-23 15:22:29
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Sensitivity Enhancement of a Surface Plasmon Resonance with Tin Selenide (SnSe) Allotropes
摘要： Single layers of tin selenide (SnSe), which have a similar structure as graphene and phosphorene, also show excellent optoelectronic properties, and have received much attention as a two-dimensional (2D) material beyond other 2D material family members. Surface plasmon resonance (SPR) sensors based on three monolayer SnSe allotropes are investigated with the transfer matrix method. The simulated results have indicated that the proposed SnSe-containing biochemical sensors are suitable to detect different types of analytes. Compared with the conventional Ag-only film biochemical sensor whose sensitivity is 116°/RIU, the sensitivities of these SnSe-based biochemical sensors containing α-SnSe, δ-SnSe, ε-SnSe, were obviously increased to 178°/RIU, 156°/RIU and 154°/RIU, respectively. The diverse biosensor sensitivities achieved with these three SnSe allotropes suggest that these 2D materials can adjust SPR sensor properties.
关键词： SPR sensor,high sensitivity,SnSe allotrope
更新于2025-09-23 15:22:29
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A Sensitive Near-Infrared Fluorescent Probe for Detecting Heavy Metal Ag+ in Water Samples
摘要： Silver is a common catalyst in industrial production, and the frequent use of Ag+ can cause water pollution. Thus, the detection of Ag+ in the environment is necessary to determine the level of pollution from silver. In this work, we designed a new, highly selective near-infrared (NIR) fluorescent probe QCy to detect Ag+. The probe exhibits 'turn-off' fluorescence quenching responses at 760 nm towards Ag+ over other relevant cations, with outstanding sensitivity and a low detection limit (0.03 μM), which is considerably lower than the standard of the World Health Organization (WHO) for drinking water (0.9 μM). Meanwhile, QCy showed a very good linearity at a low concentration of Ag+ with a 'naked eye' visible color change of solution from blue to red. The probe has been applied successfully for the detection of Ag+ in real water samples.
关键词： selectivity,fluorescence probe,Ag+,sensitivity,water samples
更新于2025-09-23 15:22:29
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Effect of tantalum content on the structural properties and sensing performance of YbTaxOy electrolyte-insulator-semiconductor pH sensors
摘要： In this work, we developed YbTaxOy sensing membranes displaying super-Nernstian pH-sensitivity for use in electrolyte-insulator-semiconductor (EIS) pH sensors. We examined the effect of tantalum content on the structural properties and sensing characteristics of the YbTaxOy sensing membranes deposited through reactive co-sputtering onto Si substrates. X-ray diffraction, atomic force microscopy, secondary ion mass spectrometry, and X-ray photoelectron spectroscopy revealed the structural, morphological, depth, and chemical features, respectively, of these YbTaxOy films prepared under various Ta plasma power conditions (from 80 to 160 W). Among the tested systems, the YbTaxOy EIS device prepared at the 120 W condition exhibited the super-Nernstian sensitivity (70.24 mV/pH), the lowest hysteresis voltage (1.5 mV), and the lowest drift rate (0.26 mV/h). Presumably, this condition optimized the stoichiometry of YbTaO4 in the film and its surface roughness while reducing the crystal defect and suppressing silicate formation at the YbTaxOy-Si interface. The super-Nernstian pH-sensitivity may be attributed to the incorporation of Ta ions in the Yb2O3 forming a YbTaO4 stoichiometric film, enhancing a change in oxidation state of Yb from trivalent ion to bivalent ion and thus transferring one electron to two protons in the redox reaction.
关键词： Electrolyte-insulator-semiconductor (EIS),Sensing characteristics,Plasma power,pH sensitivity,YbTaxOy
更新于2025-09-23 15:22:29
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Remarkable reproducibility and significant sensitivity of ZnO nanoparticles covered by Chromium (III) oxide as a hydrogen sulfide gas sensor
摘要： ZnO nanoparticles covered by Chromium (III) oxide (Cr2O3) were fabricated using spray pyrolysis and thermal evaporation technique to increase the H2S gas sensor repeatability. Gas sensing analyses showed that the Cr2O3 cover on the ZnO nanoparticle increased the response at high concentrations without affecting the operating temperature. Furthermore, there was no change in the response and recovery time after coating Cr2O3. ZnO nanoparticles covered by Cr2O3 demonstrated considerable reproducibility.
关键词： H2S,Cr2O3,Sensor,ZnO,sensitivity.,longevity
更新于2025-09-23 15:22:29
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pH-sensitive fluorescent organic nanoparticles: Off-on fluorescent detection of furfural in transformer oil
摘要： Furfural content is considered as index to estimate transformer remnant life. Therefore, low cost, highly sensitive methods for determination of furfural are highly desirable. In the present work, we describe a new strategy for furfural detection by tracing the 'off-on' fluorescence signals of fluorescent organic nanoparticles (FONPs). Significant H+-dependent emission characteristics in aprotic organic solvent was found for our synthesized poly(DOPA)-FONPs. The fluorescence of poly(DOPA)-FONPs can be quickly quenched by hydroxylamine hydrochloride. Furfural can react with hydroxylamine hydrochloride to produce furan-2-carbaldehyde oxime and release proton in a 1:1 proportion. Then H+ produced by the reaction caused the fluorescence intensity at 520 nm to increase as a linear function of furfural concentrations. Under the optimum conditions, the linear working concentration range was found to be 0.01~30 mg L-1 and the LOD for the determination of furfural was 0.0015 mg L-1. The proposed method was used to determine furfural in transformer oil samples satisfactorily, providing a convenient alternative to conventional techniques.
关键词： pH-sensitivity,Transformer oil,Fluorescent assay,Fluorescent organic nanoparticle,Detection of furfural
更新于2025-09-23 15:22:29
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A novel “turn-on” mitochondria-targeting near-infrared fluorescent probe for H2S detection and in living cells imaging
摘要： Hydrogen sulfide (H2S) has been considered to be involved in cytoprotective processes and redox signaling. It is very meaningful to track and analyze it in mitochondria. Herein, we report a novel “turn-on” mitochondria-targeting near-infrared fluorescent probe (Mito-NIR-SH) for detection of H2S in living cells, which was designed and synthesized by introducing 2,4-dinitrophenyl as fluorescence quenching group and H2S response moiety into Changsha near-infrared fluorophore (CS-OH). The structure of the fluorophore and the probe were characterized by 1H NMR, 13C NMR and mass spectrometry. Meanwhile, Mito-NIR-SH could quantitatively detect H2S at concentrations ranging from 0 to 30 μM with a detection limit as low as 89.3 nM, showing good chemical stability, fast “turn-on” response, selectively mitochondrial location, as well as high sensitivity and selectivity toward H2S. Based on this, it was successfully applied to imaging exogenous and endogenous H2S in living HeLa cells via confocal fluorescence microscopy.
关键词： High sensitivity and selectivity,Near-infrared fluorescent probe,Hydrogen sulfide,Mitochondria-targeting,Bioimaging
更新于2025-09-23 15:22:29
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Changes of Optically Stimulated Luminescence Dosimeter Sensitivity with High Dose
摘要： We investigated the effect of high dose on the sensitivity of optically stimulated luminance dosimeters (OSLDs) on Co-60 gamma rays and used a commercial OLSD (Landauer, Inc., Glenwood, IL). New OSLDs were chosen arbitrarily and were irradiated with 1 Gy repeatedly. We confirmed the change in the radiation sensitivity after repeated irradiation. The OSLD sensitivity increased up to 3% after irradiating for seven times and decreased continuously after the eighth time. It dropped by approximately 0.35 Gy per irradiation. Finally, after irradiating for 30 times, the OSLD sensitivity decreased by approximately 7%. When the OSLDs were irradiated 10 times with 1 Gy after their irradiation using a high dose of 15 Gy and 30 Gy, their sensitivity decreased by 6% and 12%, respectively, compared to that before high-dose irradiation. The change in the OSLD sensitivity with a high dose could be modeled by an exponential equation. We confirmed the radiation sensitivity variation caused by a high dose, and the irradiation history of dosimeters was considered to reuse OSLDs irradiated with a high dose.
关键词： High dose,Co-60,Optically stimulated luminescence dosimeter sensitivity
更新于2025-09-23 15:22:29
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Sensitivity-Selectivity Trade-Offs in Surface Ionization Gas Detection
摘要： Surface ionization (SI) provides a simple, sensitive, and selective method for the detection of high-proton affinity substances, such as organic decay products, medical and illicit drugs as well as a range of other hazardous materials. Tests on different kinds of SI sensors showed that the sensitivity and selectivity of such devices is not only dependent on the stoichiometry and nanomorphology of the emitter materials, but also on the shape of the electrode configurations that are used to read out the SI signals. Whereas, in parallel-plate capacitor devices, different kinds of emitter materials exhibit a high level of amine-selectivity, MEMS (micro-electro-mechanical-systems) and NEMS (nanowire) versions of SI sensors employing the same kinds of emitter materials provide significantly higher sensitivity, however, at the expense of a reduced chemical selectivity. In this paper, it is argued that such sensitivity-selectivity trade-offs arise from unselective physical ionization phenomena that occur in the high-field regions immediately adjacent to the surfaces of sharply curved MEMS (NEMS) emitter and collector electrodes.
关键词： selectivity,gas detection,corona discharge,secondary electron emission,sensitivity,surface ionization
更新于2025-09-23 15:22:29