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Early gastric cancer detection in high-risk patients: a multicentre randomised controlled trial on the effect of second-generation narrow band imaging
摘要： Objective early detection of gastric cancer has been the topic of major efforts in high prevalence areas. Whether advanced imaging methods, such as second-generation narrow band imaging (2g- nBi) can improve early detection, is unknown. Design This open-label, randomised, controlled tandem trial was conducted in 13 hospitals. Patients at increased risk for gastric cancer were randomly assigned to primary white light imaging (Wli) followed by secondary 2g- nBi (Wli group: n=2258) and primary 2g- nBi followed by secondary Wli (2g- nBi group: n=2265) performed by the same examiner. suspected early gastric cancer (egc) lesions in both groups were biopsied. Primary endpoint was the rate of egc patients in the primary examination. The main secondary endpoint was the positive predictive value (PPV) for egc in suspicious lesions detected (primary examination). results egcs were found in 44 (1.9%) and 53 (2.3%; p=0.412) patients in the Wli and 2g- nBi groups, respectively, during primary egD. in a post hoc analysis, the overall rate of lesions detected at the second examination was 25% (n=36/145), with no significant differences between groups. PPV for egc in suspicious lesions was 13.5% and 20.9% in the Wli (50/371 target lesions) and 2g- nBi groups (59/282 target lesions), respectively (p=0.015). Conclusion The overall sensitivity of primary endoscopy for the detection of egc in high- risk patients was only 75% and should be improved. 2g- nBi did not increase egc detection rate over conventional Wli. The impact of a slightly better PPV of 2g- nBi has to be evaluated further.
关键词： positive predictive value,narrow band imaging,early gastric cancer,detection rate,white light imaging
更新于2025-09-19 17:13:59
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Direct Z-scheme photocatalytic removal of ammonia via the narrow band gap MoS2/N-doped graphene hybrid catalyst upon near-infrared irradiation
摘要： Near-infrared (NIR) irradiation accounts for approximately 54.3% of the solar spectrum. Therefore, MoS2 and N-doped graphene (NG) were utilised to fabricate a direct Z-scheme NIR-response photocatalytic system (MoS2/NG). The photocatalytic tests showed that MoS2/NG Z-scheme photocatalytic system can result in a 99.6% degradation ratio of ammonia under NIR irradiation, whereas the removal ratio of ammonia was only 64.0% using MoS2 as the photocatalyst under similar conditions. The catalytic e?ciency is still over 90.7% even if the MoS2/NG catalyst was used for ?ve runs, indicating that it is extremely stable. The kinetic research indicated the ?1. The average apparent rate constant kapp for ammonia degradation into N2 was at approximately 0.251 h enhanced photocatalytic activity of MoS2/NG was attributed to the more positive valence band level of the Z-scheme system.
关键词： MoS2/N-doped graphene,Near-infrared irradiation,Degradation ammonia,Narrow band gap,Z-scheme photocatalysis
更新于2025-09-12 10:27:22
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[IEEE 2019 26th International Workshop on Active-Matrix Flatpanel Displays and Devices (AM-FPD) - Kyoto, Japan (2019.7.2-2019.7.5)] 2019 26th International Workshop on Active-Matrix Flatpanel Displays and Devices (AM-FPD) - Effect of Device Structure on the Narrow-band Light Detection of Bulk Heterostructure Organic Photodetectors based on Poly(3-hexylthiophene) and Fullerene Derivative
摘要： The characteristics of organic photodetectors based on poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl C61-butyric acid methyl ester (PCBM) blends with various film thicknesses of active layer are investigated. The red-shift in peak wavelength of incident-photon-to-current conversion efficiency (IPCE) spectra in the devices with various film thicknesses is observed with increasing film thickness. For thick devices upon irradiation by light with a photon energy of around energy gap of an active layer, excitons are formed almost uniformly because of the small absorption coefficient of red light. A conventional device with 2 μm-thick film exhibits narrow-band light detection with red-light sensitivity and the relatively narrow spectral response of the full-width at half-maximum (FWMH) of around 50 nm. On the other hand, an inverted device with 2 μm-thick film exhibits broadband light detection. For bulk heterostructure devices, one of important factors to realize the narrowband light detection is the control of charge carrier collection efficiency at electrodes which is attributed to the device structure, including the intrachain transport in polymer.
关键词： PCBM,bulk heterostructure,organic photodetectors,narrow-band light detection,P3HT
更新于2025-09-12 10:27:22
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Precipitating CsPbBr <sub/>3</sub> quantum dots in boro-germanate glass with a dense structure and inert environment toward highly stable and efficient narrow-band green emitters for wide-color-gamut liquid crystal displays
摘要： All-inorganic perovskite CsPbBr3 quantum dots (QDs) are becoming the most popular narrow-band green emitter for use as a critical material in next generation wide-color-gamut backlight displays. However, their intrinsic poor stability greatly hinders their development for practical applications. Herein, CsPbBr3 QDs were successfully precipitated in boro-germanate glass (CsPbBr3 QDs@glass) with well-designed compositions, not only retaining a high photoluminescence quantum yield (PLQY of 43% upon 450 nm excitation) and narrow bandwidth (FWHM of 22 nm), but also showing significantly enhanced stability in relation to water, heat, and UV/blue irradiation. The relative PL intensity of CsPbBr3 QDs@glass was maintained at 60% or 85% after being immersed in water for 22 days or exposed to UV light for 100 hours, respectively. Moreover, CsPbBr3 QDs@glass samples present impressive recovery abilities in thermal cycling experiments or upon intermittent blue light irradiation. Finally, an all-inorganic white light-emitting diode (white LED) achieving 125% of National Television Standards Committee (NTSC) performance was fabricated through employing green-emitting CsPbBr3 QDs@glass and red-emitting Cs2SiF6:Mn4+ phosphor-in-glass (PiG) plates as color convertors. The design rules established here could initiate the further exploration of other glass systems with moderate halide solubilities and low melting temperatures to precipitate highly e?cient and stable CsPbX3 (X = Cl, Br, I) QDs.
关键词： stability,boro-germanate glass,CsPbBr3 quantum dots,wide-color-gamut liquid crystal displays,narrow-band green emitters
更新于2025-09-12 10:27:22
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Improved banded method for spectral thermal radiation in participating media with spectrally dependent wall emittance
摘要： To develop an efficient and practical spectral radiation model for CFD simulations, a banded approach is proposed for a mixture of carbon dioxide and water vapor in varying thermodynamic states. Using a previously reported band dividing scheme, a statistical narrow band model is implemented to provide gray band absorption coefficient databases. The databases were then approximated by certain simple correlations, which can be readily used in CFD calculations of RTE solvers. The correlations were validated in several 1D and 3D benchmarks representing various combustion conditions. The accuracy and CPU cost of the proposed banded approach were studied and compared with those of other similar methods. The results demonstrated that the new approach is an efficient and accurate method that can be conveniently applied in a commercial CFD code for spectral radiation; moreover, it can handle non-gray walls. As a practical case study, the proposed approach was used to simulate radiative heat transfer within a back pass channel of a CFB boiler. The effect of combustion scenarios, i.e., air- and oxygen-fired, boiler load, inlet flow conditions, and wall material, was analyzed by the CFD model. The predictions of two different RTE solvers, i.e., P1 and DO, and the required CPU time were compared for gray and non-gray models.
关键词： Non-gray wall,Back pass channel,CFB boiler,Radiation heat transfer,Band absorption coefficient,Narrow band calculation,Non-gray gas modeling,Banded approach
更新于2025-09-11 14:15:04
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Influence of the Laser Frequency Drift in Phase-Sensitive Optical Time Domain Reflectometry
摘要： The influence of the laser frequency drift on the operation of phase-sensitive optical time domain reflectometry (?-OTDR) systems is considered. Theoretical results based on a new numerical ?-OTDR model demonstrating the influence of the laser frequency instability on a signal are reported. This model is verified based on experimental data. It has been used to calculate the signal-to-noise ratio (SNR) of the system for different parameters of the laser source stability. As a result, quantitative requirements for lasers used in ?-OTDR systems are formulated.
关键词： laser frequency fluctuation,phase-sensitive optical time domain reflectometer,narrow-band laser,distributed sensor
更新于2025-09-11 14:15:04
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Serum TGF-?2 and TNF-?± During Psoriasis Therapy with Narrowband Ultraviolet B
摘要： Although it is now an accepted concept that narrow-band UVB therapy is an efficacious therapy for psoriasis, the relationship between the response rate and the potential effects on serum cytokines is less well-established. The purpose of this study was to investigate the correlation between the response rate and the changes of serum TGF-β and TNF-α necessary for understanding the underlying mechanisms of narrow-band UVB phototherapy. NB-UVB is effective against psoriasis without any obvious side effects and can significantly decrease serum TNF-α and promote TGF-β level of psoriasis patients. Additionally, measurement of TGF-β and TNF-α in serum could be considered as biomarkers of psoriasis activity during NB-UVB therapy.
关键词： Serum Transforming Growth Factor-β (TGF-β),Narrow-Band Ultraviolet B (NB-UVB),Psoriasis,Tumour Necrosis Factor-α(TNF-α)
更新于2025-09-10 09:29:36
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Computer-assisted diagnosis of early esophageal squamous cell carcinoma using narrow-band imaging magnifying endoscopy
摘要： Background We developed a computer-assisted diagnosis model to evaluate the feasibility of automated classification of intrapapillary capillary loops (IPCLs) to improve the detection of esophageal squamous cell carcinoma (ESCC). Methods We recruited patients who underwent magnifying endoscopy with narrow-band imaging for evaluation of a suspicious esophageal condition. Case images were evaluated to establish a gold standard IPCL classification according to the endoscopic diagnosis and histological findings. A double-labeling fully convolutional network (FCN) was developed for image segmentation. Diagnostic performance of the model was compared with that of endoscopists grouped according to years of experience (senior > 15 years; mid level 10 – 15 years; junior 5 – 10 years). Results Of the 1383 lesions in the study, the mean accuracies of IPCL classification were 92.0 %, 82.0 %, and 73.3 %, for the senior, mid level, and junior groups, respectively. The mean diagnostic accuracy of the model was 89.2 % and 93.0 % at the lesion and pixel levels, respectively. The interobserver agreement between the model and the gold standard was substantial (kappa value, 0.719). The accuracy of the model for inflammatory lesions (92.5 %) was superior to that of the mid level (88.1 %) and junior (86.3 %) groups (P < 0.001). For malignant lesions, the accuracy of the model (B1, 87.6 %; B2, 93.9 %) was significantly higher than that of the mid level (B1, 79.1 %; B2, 90.0 %) and junior (B1, 69.2 %; B2, 79.3 %) groups (P < 0.001). Conclusions Double-labeling FCN automated IPCL recognition was feasible and could facilitate early detection of ESCC.
关键词： esophageal squamous cell carcinoma,intrapapillary capillary loops,computer-assisted diagnosis,narrow-band imaging,magnifying endoscopy
更新于2025-09-10 09:29:36
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Controllable luminescence in Eu2+-doped Li2Sr2Al(PO4)3 phosphor via tuning the Eu2+ concentration and codoping Ce3+
摘要： In this work, blue-emitting aluminophosphate phosphor, Li2Sr2Al(PO4)3:Eu2+, was prepared by the solid state reaction. The influence of Eu2+ concentration on the excitation and emission characteristics of Li2Sr2Al(PO4)3:Eu2+ has been studied using optical spectroscopy techniques. Upon near UV-light excitation, Li2Sr2Al(PO4)3:Eu2+ generates a blue band peaked at 445 nm, and a violet band centered at 398 nm, which originate from Eu2+ ions occupying two kinds of crystallographic sites: Sr(1)O8 and Sr(2)O9, respectively. The luminescence intensities of Eu1 and Eu2 have the strong dependence on the Eu2+ concentration. The contribution of Eu2+ luminescence from Eu1 becomes dominant with high Eu2+-doping. Li2Sr2Al(PO4)3 doped with high level of Eu2+ exhibits a strong narrow-band blue emission with a full width at half-maximum of about 42 nm. Meanwhile, the Eu2+ emission can be efficiently enhanced by codoping with Ce3+ ions using exclusive excitation into the Eu2+ absorption band. The mechanism of luminescence enhancement caused by Ce3+ ions has been determined. These results indicate that Li2Sr2Al(PO4)3:Eu2+,Ce3+ phosphor might be competitive as a potential blue-emitting phosphor for white LEDs.
关键词： Photoluminescence,Narrow-band emission,Aluminophosphate,Optical materials
更新于2025-09-10 09:29:36
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[IEEE 2018 XXIIIrd International Seminar/Workshop on Direct and Inverse Problems of Electromagnetic and Acoustic Wave Theory (DIPED) - Tbilisi, Georgia (2018.9.24-2018.9.27)] 2018 XXIIIrd International Seminar/Workshop on Direct and Inverse Problems of Electromagnetic and Acoustic Wave Theory (DIPED) - Directed Circular Polarized Antenna
摘要： The goal of proposed research is to construct the circular polarized narrow-band directed antenna using low-loss dielectric and high relative permittivity material for the substrate. Presented first part contains the simulation of such antenna using the software which based on Finite Element Method for the purpose to fined optimal parameters of such antenna before its construction. Using numerical experiment we suppose to determine best parameters of antenna, to achieve desired radiation parameters: well matched to the open space; circular polarization of radiated field; narrow-beam; wide-ban. It was designed 2.49 GHz and 2.4 GHz circular polarization radiation patch antennas, which was archived by cutting edges from square patch antenna. For simulation it was used 6.8 relative permittivity material for the substrate.
关键词： Patch Antenna,Narrow-band,Circular Polarization
更新于2025-09-09 09:28:46