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Feasibility of using an led-probe in third-space endoscopy: a clinical study
摘要： Background: Third-space endoscopy is a novel, safe, and effective method for treating different gastrointestinal conditions. However, several failed endoscopic procedures are attributed to incomplete myotomy. Lighting devices are used to prevent organic injuries. We aimed to investigate the feasibility of using a hand-made LED-probe (LP) in third-space procedures. Methods: This prospective study was conducted in a tertiary-care center in Mexico between December 2016 and January 2019. We included peroral endoscopic myotomy (POEM) and gastric peroral endoscopic myotomy(G-POEM) procedures. Pseudoachalasia, peptic ulcer, normal gastric emptying scintigraphy (GES) and prepyloric tumors were excluded. LP was used to guide or confirm procedures. Clinical and procedural characteristics were recorded and analyzed. Results: Seventy third-space procedures were included (42POEM,28G-POEM), with an average patient age of 46.7 ± 14.3 and 43.7 ± 10.1 years, respectively. For the POEM and G-POEM groups, respectively, 18/42(42.9%) and 13/28(46.7%) patients were males; median procedure times were 50 (interquartile range [IQR]: 38–71) and 60(IQR: 48–77) min, median LP placement times were 5(IQR: 4-6) and 6(IQR: 5-7) min, mild adverse events occurred in 4(9.4%) and 4(14.2%) of cases, and clinical success at 6 months occurred in 100 and 85.7% of cases. Integrated relaxation pressure (IRP) improved from 27.3 ± 10.8 to 9.5 ± 4.1 mmHg (p < 0.001); retention percentage at 4 h also improved. LP was successfully placed and adequate myotomy confirmed including 14.2 and 17.8% of POEM and G-POEM difficult patients. Conclusions: Using an LP is promising and allows guiding during third-space procedures either for submucosal tunnel creation or myotomy confirmation, with excellent safety and efficacy in clinical practice.
关键词： LED-probe,Third-space endoscopy,Gastric peroral endoscopic myotomy,Peroral endoscopic myotomy
更新于2025-09-23 15:21:01
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Copper nanoclusters @ nitrogen-doped carbon quantum dots-based ratiometric fluorescence probe for lead (II) ions detection in porphyra
摘要： A novel ratiometric fluorescence probe was proposed for detecting lead (II) ions (Pb2+) in porphyra, the approach was based on copper nanoclusters and nitrogen-doped carbon quantum dots (CuNCs-CNQDs). In this probe, the CuNCs delivered the response signal, the fluorescence of which was enhanced by Pb2+ due to the aggregation-induced emission enhancement (AIEE) between Pb2+ and CuNCs. The CNQDs provided the self-calibration signal, whose fluorescence remained almost unchanged in coexistence with Pb2+. According to the change of fluorescence intensity ratio between the fluorophores, CuNCs–CNQDs nanohybrid was used as ratiometric probes for the sensitive detection of Pb2+ in the range of 0.010 to 2.5 mg L-1, with a detection limit of 0.0031 mg L-1. Finally, the probe was successfully applied to detect Pb2+ in porphyra with relative standard deviations (RSDs) lower than 5%. This study provides a straightforward, stable, and sensitive approach for detecting Pb2+ in porphyra.
关键词： Lead (II) ions,Ratiometric fluorescence probe,Aggregation-induced emission enhancement,Copper nanoclusters,Nitrogen-doped carbon quantum dots
更新于2025-09-23 15:21:01
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Design, synthesis, crystal structure and cytotoxicity studies of colorimetric fluorescent “OFF-ON” probes for rapid detection of hydrogen sulfide based on Cu(II) complex
摘要： Four colorimetric fluorescent probes based on copper(II) complexes were synthesized and the molecular structures were characterized by X-ray diffraction, ESI-HRMS and elemental analysis. When exposed to HS–, the synthesized probes showed significant color changes from yellow to red and remarkable increase of fluorescence intensity (over 80-fold). What’s more, the interaction of host-guest could be completed in 2 minutes. However, no clear color and fluorescence intensity changes were observed in the presence of other anions (AcO–, H2PO4–, F–, Cl–, Br–, I–, SO42-, SO32-, CO32-, Cys and GSH). The synthesized colorimetric fluorescent probes could detect HS– rapidly and conveniently. Cytotoxicity studies indicated that the synthesized fluorescent probes were low cytotoxicity in Hela cells and may be used to detect H2S level in vivo.
关键词： hydrogen sulfide,copper complex crystal,fluorescent probe,colorimetric detection,cytotoxicity
更新于2025-09-23 15:21:01
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Dual-Site and Dual-Excitation Fluorescent Probe That Can Be Turned for Discriminative Detection of Cysteine, Homocystein, and Thiophenols
摘要： Thiols play a vital role in both the physiological process and organic synthesis field, including aliphatic thiols (e.g., Cys, Hcy, and GSH) and thiophenols. Due to the similarity of thiols in terms of molecular structure and chemical properties, it is difficult for conventional fluorescent probes to distinguish them, which hinders the progress of biological and pathological research. Keeping this in mind, a dual-site and dual-excite fluorescent probe (YY) was designed to distinguish Cys, Hcy, and thiophenols by three different reaction paths. When excited at 470 nm, YY only exhibits a fluorescence OFF-ON response towards thiophenols. However, when excited at 453 nm, YY not only displays a fluorescence OFF-ON response towards Hcy and thiophenols (λem = 499 and 561 nm) but also presents a two-stage fluorescence response towards Cys, which possesses a fluorescence OFF-ON response in the first stage (λem = 501 nm) and then a fluorescence ON-OFF response in the second stage (λem = 556 nm). This specific fluorescence response indicates that YY has ability to overcome the above-mentioned challenge to achieve discriminative detection of Cys, Hcy, and thiophenols qualitatively, which promotes the study of thiols in the field of physiology and pathology. Furthermore, cell-imaging studies show that YY can be applied to the imaging of exogenous Cys, Hcy, and thiophenols through two different emission channels.
关键词： thiophenols,discriminative detection,thiols,fluorescent probe,Cys,Hcy
更新于2025-09-23 15:21:01
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Automated evaluation of probe-based confocal laser endomicroscopy in the lung
摘要： Probe-based confocal endomicroscopy provides real time videos of autoflourescent elastin structures within the alveoli. With it, multiple changes in the elastin structure due to different diffuse parenchymal lung diseases have previously been described. However, these evaluations have mainly relied on qualitative evaluation by the examiner and manually selected parts post-examination. Objectives To develop a fully automatic method for quantifying structural properties of the imaged alveoli elastin and to perform a preliminary assessment of their diagnostic potential. Methods 46 patients underwent probe-based confocal endomicroscopy, of which 38 were divided into 4 groups categorizing different diffuse parenchymal lung diseases. 8 patients were imaged in representative healthy lung areas and used as control group. Alveolar elastin structures were automatically segmented with a trained machine learning algorithm and subsequently evaluated with two methods developed for quantifying the local thickness and structural connectivity. Measurements and main results The automatic segmentation algorithm performed generally well and all 4 patient groups showed statistically significant differences with median elastin thickness, standard deviation of thickness and connectivity compared to the control group. Conclusion Alveoli elastin structures can be quantified based on their structural connectivity and thickness statistics with a fully-automated algorithm and initial results highlight its potential for distinguishing parenchymal lung diseases from normal alveoli.
关键词： diffuse parenchymal lung diseases,automated evaluation,elastin structures,probe-based confocal laser endomicroscopy,lung
更新于2025-09-23 15:21:01
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Decoupling mesoscale functional response in PLZT across the ferroelectric – relaxor phase transition with contact Kelvin probe force microscopy and machine learning
摘要： Relaxor ferroelectrics exhibit a range of interesting material behavior including high electromechanical response, polarization rotations as well as temperature and electric field-driven phase transitions. The origin of this unusual functional behavior remains elusive due to limited knowledge on polarization dynamics at the nanoscale. Piezoresponse force microscopy and associated switching spectroscopy provide access to local electromechanical properties on the micro- and nanoscale, which can help to address some of these gaps in our knowledge. However, these techniques are inherently prone to artefacts caused by signal contributions emanating from electrostatic interactions between tip and sample. Understanding functional behavior of complex, disordered systems like relaxor materials with unknown electromechanical properties therefore requires a technique that allows to distinguish between electromechanical and electrostatic response. Here, contact Kelvin probe force microscopy (cKPFM) is used to gain insight into the evolution of local electromechanical and capacitive properties of a representative relaxor material lead lanthanum zirconate across the phase transition from a ferroelectric to relaxor state. The obtained multidimensional data set was processed using an unsupervised machine learning algorithm to detect variations in functional response across the probed area and temperature range. Further analysis showed formation of two separate cKPFM response bands below 50°C, providing evidence for polarization switching. At higher temperatures only one band is observed, indicating an electrostatic origin of the measured response. In addition, from the cKPFM data qualitatively extracted junction potential difference, becomes independent of the temperature in the relaxor state. The combination of this multidimensional voltage spectroscopy technique and machine learning allows to identify the origin of the measured functional response and to decouple ferroelectric from electrostatic phenomena necessary to understand the functional behavior of complex, disordered systems like relaxor materials.
关键词： phase transition,machine learning,Relaxor ferroelectric,lead lanthanum zirconium titanate,piezoresponse force microscopy,k-means clustering,contact Kelvin probe force microscopy
更新于2025-09-23 15:21:01
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Crystalline structure, electronic and lattice-dynamics properties of NbTe2
摘要： Layered-structure materials are currently relevant given their quasi-2D nature. Knowledge of their physical properties is currently of major interest. Niobium ditelluride possesses a monoclinic layered-structure with a distortion in the tellurium planes. This structural complexity has hindered the determination of its fundamental physical properties. In this work, NbTe2 crystals were used to elucidate its structural, compositional, electronic and vibrational properties. These findings have been compared with calculations based on density functional theory. The chemical composition and elemental distribution at the nanoscale were obtained through atom probe tomography. Ultraviolet photoelectron spectroscopy allowed the first determination of the work function of NbTe2. Its high value, 5.32 eV, and chemical stability allow foreseeing applications such as contact in optoelectronics. Raman spectra were obtained using different excitation laser lines: 488, 633, and 785 nm. The vibrational frequencies were in agreement with those determined through density functional theory. It was possible to detect a theoretically-predicted, low-frequency, low-intensity Raman active mode not previously observed. The dispersion curves and electronic band structure were calculated, along with their corresponding density of states. The electrical properties, as well as a pseudo-gap in the density of states around the Fermi energy are characteristics proper of a semi metal.
关键词： Electronic band structure,Ultraviolet photoelectron spectroscopy,Density functional theory,Atom probe tomography,Niobium ditelluride,Layered-structure materials,Raman spectra,Density of states,Semimetal
更新于2025-09-23 15:21:01
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[IEEE 2018 IEEE 5G World Forum (5GWF) - Silicon Valley, CA, USA (2018.7.9-2018.7.11)] 2018 IEEE 5G World Forum (5GWF) - Feasibility and Challenges of Over-The-Air Testing for 5G Millimeter Wave Devices
摘要： The evolution from 1G through 5G cellular technologies has been fueled mainly by the insatiable need for speed, lower latency, high reliability and enhanced flexibility of use across the wireless ecosystem. Using multiple antennas in conjunction with complex modulation schemes has rendered each generation of cellular technology an enhanced version over its former counterpart. 5G technology aims to exploit previously unchartered higher millimeter wave (mmWave) frequencies & larger bandwidths towards realizing the goal of greater data throughput, while simultaneously enhancing data reliability and reducing latency. The small wavelength of mmWave signals makes it possible to design 5G devices using several multi-element phased array antennas with small element-element spacing. However, unlike the antenna designs of 2G/3G/4G devices, 5G multi-element antennas would be integrated with the radio frequency integrated circuit (RFIC) board of the 5G device. The tight integration between antennas and RFIC renders the antenna port of the device under test (DUT) inaccessible for physical connections using cables/connectors to test equipment. Since conducted testing with cables is not feasible anymore, radiated over-the-air (OTA) testing becomes mandatory for 5G mmWave device verification. This paper aims to assess the feasibility of candidate OTA test methods for 5G mmWave test requirements. The challenges of testing 5G mmWave devices over-the-air have been elucidated and alternative OTA test solutions for overcoming these challenges have also been discussed.
关键词： multi-probe anechoic chamber (MPAC),Multiple-input multiple-output (MIMO),compact antenna test range (CATR),far-field,near-field,antenna arrays
更新于2025-09-23 15:21:01
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[IEEE 2018 IEEE International Symposium on the Physical and Failure Analysis of Integrated Circuits (IPFA) - Singapore (2018.7.16-2018.7.19)] 2018 IEEE International Symposium on the Physical and Failure Analysis of Integrated Circuits (IPFA) - Nano C-V imaging of Semiconductor Devices with Scanning Microwave Impedance Microscopy
摘要： Two doped semiconductor samples are measured using probe-based Scanning Microwave Impedance Microscopy (sMIM). One is a plan-view polished CMOS image sensor and the other is a cross-section polished power device. Both samples are imaged with sMIM using two different approaches: the first using a dual pass method with dC/dV images acquired simultaneously with sMIM during the first pass in contact mode, and the second pass at a fixed offset from the surface. The second method uses a non-resonant mode where C-V are acquired at specific lateral locations. The C-V curves are used to determine polarity compared to dC/dV and also to distinguish p-n junctions, characterize doping concentration, and build images at constant DC values to discern subtle changes not evident in traditional SCM imaging.
关键词： Nano-C-V,SCM,Scanning Probe Microscopy,doping characterization,Scanning Microwave Impedance Microscopy,Scanning Capacitance Microscopy,sMIM
更新于2025-09-23 15:21:01
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[IEEE SoutheastCon 2018 - St. Petersburg, FL (2018.4.19-2018.4.22)] SoutheastCon 2018 - BWO and IMPATT Millimeter Wave Probing of c-Si, and Perovskite
摘要： In this paper, we provide a short review of electrovacuum microwave generator “carcinotron” (backward wave oscillator, BWO) and other microwave sources that are used for materials characterization. Time averaged photoresponse transients of c-silicon, and hybrid perovskite obtained using electrovacuum probe source BWO are compared with photo-responses of the same samples using solid-state Impact Ionization Avalanche Transit-time (IMPATT) diode cavity oscillator probe. We discuss outcomes of using two different probing sources operated at 140 GHz. IMPATT probe source yields a slightly higher crest factor than the BWO source as evidenced from perovskite response to light, and no systematic relationship was found between mmw transmissivity and stimulating laser (pump) fluence.
关键词： signal,materials,conductivity,beam,oscillator,probe
更新于2025-09-23 15:21:01