Perovskite-Doped Modulated Color-Selective Photosynaptic Transistors for Target Object Recognition.

The processing of multicolor noisy images in visual neuromorphic devices requires selective absorption at specific wavelengths; however, it is difficult to achieve this because the spectral absorption range of the device is affected by the type of material. Surprisingly, the absorption range of perovskite materials can be adjusted by doping. Herein, a CdCl2 co-doped CsPbBr3 nanocrystal-based photosensitive synaptic transistor (PST) is reported. By decreasing the doping concentration, the response of the PST to short-wavelength light is gradually enhanced, and even weak light of 40 µW·cm-2 can be detected. Benefiting from the excellent color selectivity of the PST device, the device array is applied to feature extraction of target blue items and removal of red and green noise, which results in the recognition accuracy of 95% for the noisy MNIST data set. This work provides new ideas for the application of novel transistors integrating sensors and storage computing.

Broadband beam collimation metasurface for full-color micro-LED displays.

Near-eye displays are widely recognized as a groundbreaking technological advancement with the potential to significantly impact daily life. Within the realm of near-eye displays, micro-LEDs have emerged as a highly promising technology owing to their exceptional optical performance, compact form factor, and low power consumption. However, a notable challenge in integrating micro-LEDs into near-eye displays is the efficient light collimation across a wide spectrum range. In this paper, we propose what we believe to be a novel design of a broadband beam collimation metasurface for full-color micro-LEDs by harnessing wavefront phase modulation based on Huygens' principle. Our results demonstrate a substantial reduction in the full width at half maximum (FWHM) angles, achieving a reduction to 1/10, 1/10, and 1/20 for red, green, and blue micro-LEDs compared to those without the metasurface, which is the best collimation result as far as we know. The central light intensity increases by 24.60, 36.49, and 42.15 times. Furthermore, the significant enhancement in the light energy within ±10° is achieved, with the respective multiplication factors of 14.16, 15.60, and 13.00. This metasurface has the potential to revolutionize the field by enabling high-performance, compact, and lightweight micro-LED displays, with applications in near-eye displays, micro-projectors, and beyond.

Virtual bronchoscopic navigation with intraoperative cone-beam CT for the diagnosis of peripheral pulmonary nodules.

OBJECTIVE: Transbronchial biopsy is a safe manner with fewer complications than percutaneous transthoracic needle biopsy; however, the current diagnostic yield is still necessitating further improvement. We aimed to evaluate the diagnostic yield of using virtual bronchoscopic navigation (VBN) and cone-beam CT (CBCT) for transbronchial biopsy and to investigate the factors that affected the diagnostic sensitivity. METHODS: We retrospectively investigated 255 patients who underwent VBN-CBCT-guided transbronchial biopsy at our two centers from May 2021 to April 2022. A total of 228 patients with final diagnoses were studied. Patient characteristics including lesion size, lesion location, presence of bronchus sign, lesion type and imaging tool used were collected and analyzed. Diagnostic yield was reported overall and in groups using different imaging tools. RESULTS: The median size of lesion was 21 mm (range of 15.5-29 mm) with 46.1% less than 2 cm in diameter. Bronchus sign was present in 87.7% of the patients. The overall diagnostic yield was 82.1%, and sensitivity for malignancy was 66.3%. Patients with lesion > 2 cm or with bronchus sign were shown to have a significantly higher diagnostic yield. Four patients had bleeding and no pneumothorax occurred. CONCLUSION: Guided bronchoscopy with VBN and CBCT was an effective diagnostic method and was associated with a high diagnostic yield in a safe manner. In addition, the multivariant analysis suggested that lesion size and presence of bronchus sign could be a predictive factor for successful bronchoscopic diagnosis.

Effect of polymethyl methacrylate on in situ patterning of perovskite quantum dots by inkjet printing.

The preparation of perovskite quantum dots (PQDs) using an in situ inkjet printing method is beneficial for improving the problems of aggregation and photoluminescence (PL) quenching during long-term storage. However, the stability of PQDs prepared using this method is still not ideal, and the morphology of in situ-printed patterns needs to be optimized. To address these problems, this study introduced polymethyl methacrylate (PMMA) into the process of in situ inkjet printing of PQDs and explored the effect of PMMA on the in situ patterning effect of PQDs. The results showed that using a mixed precursor solution containing a small amount of PMMA as the printing ink can slow down the shrinkage process of ink droplets and improve the uniformity of film formation. As the printing substrate, PMMA provided a suitable high-viscosity environment for the in situ growth of PQDs. This could effectively suppress the coffee ring effect. In addition, the interaction between the C=O=C group in PMMA and metal ion Pb2+ in the CsPbBr3 precursor molecules was favourable to enhancing the density of PQDs. The prepared PMMA-coated CsPbBr3 quantum dots (QDs) pattern had high stability and could maintain at 90.08% PL intensity after 1 week of exposure to air.

Prediction of prognostic and immune therapy response in lung adenocarcinoma based on MHC-I-related genes.

OBJECTIVES: The study investigated the prognostic and immune predictive potential of major histocompatibility complex class I (MHC-I) in lung adenocarcinoma (LUAD). MATERIALS AND METHODS: With The Cancer Genome Atlas (TCGA)-LUAD and Gene Expression Omnibus datasets (GSE26939, GSE72094) as the training and validation sets, respectively, we used Cox regression analysis to construct a prognostic model, and verified independence of riskscore. The predictive capacity of the model was assessed in both sets using the receiver operating characteristic curve and Kaplan-Meier survival curves. Immune analysis was performed by using ssGSEA. Additionally, immune checkpoint blockade therapy was assessed by using immunophenoscore, Tumor Immune Dysfunction and Exclusion score. Based on the cMAP database, effective small molecule compounds were predicted. RESULTS: A prognostic model was established based on 8 MHC-I-related genes, and the predictive capacity of the model was accurate. Immune analysis results revealed that patients classified as high-risk had lower levels of immune cell infiltration and impaired immune function. The low-risk group possessed a better response to immune checkpoint blockade therapy. Theobromine and pravastatin were identified as having great potential in improving the prognosis of LUAD. CONCLUSION: Overall, the study revealed MHC-I-related molecular prognostic biomarkers as robust indicators for LUAD prognosis and immune therapy response.

Displacement Sensing for Laser Self-Mixing Interferometry by Amplitude Modulation and Integral Reconstruction.

To robustly and adaptively reconstruct displacement, we propose the amplitude modulation integral reconstruction method (AM-IRM) for displacement sensing in a self-mixing interferometry (SMI) system. By algebraically multiplying the SMI signal with a high-frequency sinusoidal carrier, the frequency spectrum of the signal is shifted to that of the carrier. This operation overcomes the issue of frequency blurring in low-frequency signals associated with continuous wavelet transform (CWT), enabling the precise extraction of the Doppler frequency of the SMI signal. Furthermore, the synchrosqueezing wavelet transform (SSWT) is utilized to enhance the frequency resolution of the Doppler signal. Our experimental results demonstrate that the proposed method achieves a displacement reconstruction accuracy of 21.1 nm (0.89%). Additionally, our simulations demonstrated that this method can accurately reconstruct target displacement under the conditions of time-varying optical feedback intensity or a signal-to-noise ratio (SNR) of 0 dB, with a maximum root mean square (RMS) error of 22.2 nm. These results highlight its applicability in real-world environments. This method eliminates the need to manually determine the window length for time-frequency conversion, calculate the parameters of the SMI system, or add additional optical devices, making it easy to implement.

Metamaterials for light extraction and shaping of micro-scale light-emitting diodes: from the perspective of one-dimensional and two-dimensional photonic crystals.

Metamaterials have attracted broad attention owing to their unique versatile micro- and nano-structures. As a kind of typical metamaterial, photonic crystals (PhCs) are capable of controlling light propagation and constraining spatial light distribution from the chip level. However, introducing metamaterial into micro-scale light-emitting diodes (µLED) still exists many unknowns to explore. This paper, from the perspective of one-dimensional and two-dimensional PhCs, studies the influence of metamaterials on the light extraction and shaping of µLEDs. The µLEDs with six different kinds of PhCs and the sidewall treatment are analyzed based on finite difference time domain (FDTD) method, in which the optimal match between the PhCs type and the sidewall profile is recommended respectively. The simulation results show that the light extraction efficiency (LEE) of the µLEDs with 1D PhCs increases to 85.3% after optimizing the PhCs, and is further improved to reach 99.8% by the sidewall treatment, which is the highest design record so far. It is also found that the 2D air ring PhCs, as a kind of left-handed metamaterials, can highly concentrate the light distribution into 30° with the LEE of 65.4%, without help of any light shaping device. The surprising light extraction and shaping capability of metamaterials provides a new direction and strategy for the future design and application of µLED devices.

Omnidirectional color shift suppression of full-color micro-LED displays with enhanced light extraction efficiency.

The three-primary-color chip array is the most straightforward to realize full-color micro-LED displays. However, the luminous intensity distribution shows high inconsistency between the AlInP-based red micro-LED and GaN-based blue / green micro-LEDs, resulting in the issue of angular color shift with different viewing angles. This Letter analyzes the angular dependence of color difference of conventional three-primary-color micro-LEDs, and proves that the inclined sidewall with homogeneous Ag coating has a limited angular regulation effect for micro-LEDs. Based on this, a patterned conical microstructure array is designed on the micro-LED's bottom layer to effectively eliminate the color shift. This design cannot only regulate the emission of full-color micro-LEDs to perfectly meet Lambert's cosine law without any external beam shaping elements, but also improve the light extraction efficiency of top emission by 16%, 161%, and 228% for red, green, and blue micro-LEDs, respectively. The color shift Δ u ' v ' of the full-color micro-LED display is also kept below 0.02 with the viewing angle ranging from 10° to 90°.

Uniformity improvement of a mini-LED backlight by a quantum-dot color conversion film with nonuniform thickness.

Mini-LED backlights energized by quantum-dot color conversion (QDCC) hold great potential for technological breakthroughs of liquid crystal displays. However, luminance uniformity issues should still be urgently solved owing to the large interval of direct-lit mini-LEDs, especially when covering with a QDCC film (QDCCF) with uniform thickness. Herein, we propose a uniformity improvement approach of mini-LED backlights by employing a QDCCF with nonuniform thickness based on the Lambertian distribution of mini-LEDs, which is demonstrated by screen-printing preparation and ray-tracing simulation. Experimental results show that the luminance uniformity of the nonuniform QDCCF can reach 89.91%, which is 24.92% higher than the uniform one. Ray-tracing simulation further elaborates the mechanism of this significant improvement. Finally, by employing this nonuniform QDCCF, a mini-LED backlight prototype is assembled and achieves high uniformity of 92.15%, good white balance with color coordinates of (0.3482, 0.3137), and high color gamut of 109% NTSC. This work should shed some new light on mini-LED-based display technology.

Baicalin attenuates XRCC1-mediated DNA repair to enhance the sensitivity of lung cancer cells to cisplatin.

Baicalin plays important roles in different types of cancer. A previous report showed that baicalin attenuates cisplatin resistance in lung cancer. However, its mechanism remains unclear. In this study, we investigated the effect and mechanism of baicalin on DNA repair and sensitivity of lung cancer cells to cisplatin. A549 and A549/DPP cells were treated with baicalin and cisplatin. A549/DPP cells were transfected with XRCC1 and siXRCC1. Cell viability and DNA damage were detected by MTT and comet assay. Apoptosis rate and cell cycle were detected by flow cytometry assay. The expressions of Bax, Bcl-2, and Cyclin D1 were detected by western blot. XRCC1 expression was detected by reverse transcription quantitative polymerase chain reaction (RT-qPCR) and western blot. Baicalin and cisplatin decreased cell viability in A549 and A549/DPP cells in dose-dependent manner. Baicalin enhanced the effect of cisplatin on promoting apoptosis, arresting cell on S stage and triggering DNA damage accompanied with the upregulation of Bcl-2-associated X protein (Bax) and downregulation of B-cell lymphoma 2 (Bcl-2) and Cyclin D1 in A549/DPP cells. Moreover, baicalin promoted the inhibitory effect of cisplatin on XRCC1 expression in A549 and A549/DPP cells. However, the synthetic effects of baicalin and cisplatin on A549/DPP cells were partially inhibited by XRCC1 overexpression and promoted by XRCC1 knockdown. This study demonstrates that baicalin interferes with XRCC1-mediated cellar DNA repair to sensitize lung cancer cells to cisplatin.

Quantum-dot array with a random rough interface encapsulated by atomic layer deposition.

This Letter proposes the use of atomic layer deposition (ALD) encapsulation as a stability-improving approach for a quantum-dot micro-structural array (QDMA) with a random rough interface. The QDMA is first prepared by screen printing technology on an edge-lit light-guide plate (LGP) for backlight application. A flexible aluminum oxide film is then densely deposited onto the rough surface of the QDMA. The influences of two key factors, the reaction temperature and deposition thickness, on the encapsulation effect and output performance of this QD backlight are discussed. After ALD encapsulation, the water vapor transmission rate was measured to be less than 0.014 g/(m2 day). The average luminance of the encapsulated QD backlight remained stable after continuous working for 200 h, while an unencapsulated QD backlight lost over 50% of its initial luminance. The complete attenuation trend for the encapsulated QD backlight was analyzed in a more demanding testing environment, and results showed that 80% (>3000 cd/m2) of the initial luminance was maintained after 250 h at a high temperature of 70 °C and a relative humidity of 90%. The mechanism behind these experimental results is also discussed.

Efficiency improvement of GaN-based micro-light-emitting diodes embedded with Ag NPs into a periodic arrangement of nano-hole channel structure by ultra close range localized surface plasmon coupling.

NH-µLED, namely a micro light-emitting diode structure with nano-holes dug all the way through the active region, is designed to make silver nanoparticles in extremely close contact with the quantum wells for improving the coupling between the localized surface plasmon and the quantum wells (LSP-QWs coupling) and thus enhancing the optical properties of theµLED. The experimental results show that, thanks to this deep nanohole structure, the LSP-QWs coupling can be realized effectively, which ultimately increases the optical performance of theµLED. The internal quantum efficiency of the NH-µLED filled with silver nanoparticles is increased by 12%, and the final optical output power is also enhanced. We have further carried out a comparison study which measures the transient lifetime of two different types ofµLEDs, and the results provide convincing evidence for the existence of the ultra close range LSP-QWs coupling effect.

MTHFD2 promotes tumorigenesis and metastasis in lung adenocarcinoma by regulating AKT/GSK-3ß/ß-catenin signalling.

Recent studies have demonstrated that one-carbon metabolism plays a significant role in cancer development. Methylenetetrahydrofolate dehydrogenase 2 (MTHFD2), a mitochondrial enzyme of one-carbon metabolism, has been reported to be dysregulated in many cancers. However, the specific role and mechanism of MTHFD2 in lung adenocarcinoma (LUAD) still remains unclear. In this study, we evaluated the clinicopathological and prognostic values of MTHFD2 in LUAD patients. We conducted a series of functional experiments in vivo and in vitro to explore novel mechanism of MTHFD2 in LUAD. The results showed that MTHFD2 was significantly up-regulated in LUAD tissues and predicted poor prognosis of LUAD patients. Knockdown of MTHFD2 dramatically inhibited cell proliferation and migration by blocking the cell cycle and inducing the epithelial-mesenchymal transition (EMT). In addition, MTHFD2 knockdown suppressed LUAD growth and metastasis in cell-derived xenografts. Mechanically, we found that MTHFD2 promoted LUAD cell growth and metastasis via AKT/GSK-3ß/ß-catenin signalling. Finally, we identified miR-30a-3p as a novel regulator of MTHFD2 in LUAD. Collectively, MTHFD2 plays an oncogenic role in LUAD progression and is a promising target for LUAD diagnosis and therapy.

Optimal dimension of edge-lit light guide plate based on light conduction analysis.

Dimensions of the edge-lit light guide plate (LGP) have a non-negligible impact on its output performance based on a pre-determined micro-dot array. However, how the LGP's dimension affects the performance has not been systematically researched. In this paper, the dimension of the LGP is numerically established as a function to the light output performance, which can be divided into four successive procedures. Firstly, the micro-structural dot array is designed based on the calculated illuminance distribution of the LGP's bottom surface. Based on this, the light energy output can be derived by defining three key parameters, which are dot density, scatting coefficient, and collision loss coefficient. After that, the ray-tracing simulation is used to determine the above parameters. Finally, the optimal dimensions of the LGP can be obtained with a specific correlation function with the light energy output. The mathematical relation above is demonstrated via both simulation and experiment. Our approach provides a systematic design for balancing the efficiency and uniformity of backlight by combining the dot design and the dimensional optimization, which has important theoretical guiding significance for actual display application.

Issue of spatial coherence in MQW based micro-LED simulation.

In existing flip-chip LED simulations, the light extraction efficiency is related to the multiple quantum well (MQW) to metal reflector distance because of optical interference. We calculate the contrast using several typical light intensity distributions among the several QWs in MQW. The coherence is obtained analytically. When the luminosity of each QW is equal, the contrast is ∼0, meaning the light is incoherent, contrary to traditional studies. The spatial coherence is important only when the light emission comes from just one QW. As the MQW has a not negligible thickness, the traditional single-dipole model is no longer accurate.

Precise theoretical model for quantum-dot color conversion.

Quantum-dot color conversion (QDCC) is a promising technique for next-generation full-color displays, such as QD converted organic light-emitting diodes and micro light-emitting diodes. Although present QDCC research has made some progress on the experimental aspect, the optical model and corresponding mathematical expression that can lay an indispensable foundation for QDCC have not been reported yet. In this paper, we present a theoretical model for precisely describing the complete optical behavior of QDCC, including optical transmission, scattering, absorption, and conversion process. A key parameter of QDCC, called dosage factor (DoF), is defined to quantitatively express the total consumption of QDs that can be calculated as the product of film thickness and QD concentration. Theoretical relations are established between DoF and three key performance indicators of QDCC, namely the light conversion efficiency (LCE), blue light transmittance (BLT), and optical density (OD). The maximum LCE value can be predicted based on this theoretical model, as well as the relationship between the slope of the OD curve and the molar absorption coefficient of blue light. This theoretical model is verified by both simulation and experiment. Results show that the simulation and experimental data highly match the theoretical model, and the goodness of fit reaches higher than 96% for LCE, BLT, and OD. Based on this, the optimal interval of DoF is recommended that provides key guiding significance to the QDCC related experiment.

Edge/direct-lit hybrid mini-LED backlight with U-grooved light guiding plates for local dimming.

Current mini-LED backlights improve high-dynamic-range liquid crystal displays (LCDs) by using tens of thousands of direct-lit sources for local dimming. However, relative thick profile and high power consumption are the inherent limitations while compared with edge-lit backlights. By synthesizing edge- and direct-lit advantages, we propose a novel hybrid mini-LED backlight equipped with a specially designed integrated light guiding plate (LGP) for large-area displays. This LGP is seamlessly spliced by multiple physically segmented sub-LGPs with a scattering dot array on the bottom and U-shaped grooves at the corners. Each sub-LGP is a single local dimming zone that can be independently controlled. Scattering dot distribution can be numerically calculated even from multiple edge-lit sources. High optical performance and satisfactory local dimming effect are verified and analyzed via both simulation and experiment. The experimental spatial illuminance uniformity and the light extraction efficiency reach 81% and 83% while the crosstalk can be well suppressed below 0.2% between adjacent local dimming zones. The significant advantages of our design towards state-of-the-art mini-LED backlights include the zero optical distance for an ultra-thin profile, low mini-LED amount for local dimming, high optical efficiency, and infinite extension of zone number, which is expected to have a broad application prospect in the near future.

Projection optical engine design based on tri-color LEDs and digital light processing technology.

Digital light processing (DLP) is currently a cutting-edge technology for desktop projection optical engines. Due to the passive luminescence characteristics, the DLP projection engine needs a few specific illumination optical components for light collimation, homogenization, and color combination, together with a projection lens matching the DLP chip and magnifying the image. In this paper, we propose a design approach that first splits the DLP projection optical engine into individual components for separate design, and then integrates them into a whole system for further verification. For the first step, the collimating lens group is designed for light collection, and the dichroic mirrors are used to fold the light path based on tri-color LED light sources. For the second step, a fly-eye lens and the corresponding relay lens group are designed to achieve uniform illumination on the DMD chip. The third step is to optimize the projection lens group for high-resolution projection display. Based on the design and simulation, the optical efficiency is 63.4% and the uniformity reaches 94.9% on the projection screen. The modulation transfer function (MTF) of the projection lens is higher than 0.4 at 66 lines for the distance of 500∼1500mm, and the distortion is lower than 1%. Simulation results show that the total luminous flux is estimated to reach 224.15 lm when the powers of tri-color LEDs are 21 W, 15.5 W, and 25 W, respectively. A projector prototype is built and tested for further verification, which provides a luminous flux of 220.43 lm and uniformity of 90.22%, respectively. The proposed design, demonstrated by both simulation and experiment, exhibits high feasibility and application potential in state-of-the-art commercial projector design.

Migration of ingested sharp foreign body into the bronchus: a case report and review of the literature.

BACKGROUND: Foreign body ingestion is a common emergence in gastroenterology. Foreign bodies are most likely to be embedded in the esophagus. The sharp ones may penetrate the esophageal wall and lead to serious complications. CASE PRESENTATION: A 72-year-old Chinese female was admitted to our hospital with a 4-day history of retrosternal pain and a growing cough after eating fish. Chest computed tomography scan indicated that a high-density foreign body (a fish bone) penetrated through the esophageal wall and inserted into the left main bronchus. First, we used a rigid esophagoscope to explore the esophagus under general anesthesia. However, the foreign body was invisible in the side of the esophagus. Then, the fiberoptic bronchoscopy was performed. We divided the fish bone, which traversed the left main bronchus, into two segments under holmium laser and removed the foreign body successfully. The operation time was short and there were no complications. The patient was discharged 1 week postoperatively and was symptom free even under a liquid diet. CONCLUSIONS: There are several challenges in the management of this rare condition. We applied the technique of interventional bronchoscopy to the management of esophageal foreign body flexibly in an emergency. A surgery was avoided, which was more invasive and costly.

Innovative method for Amplatzer device implantation in patients with bronchopleural fistulas.

BACKGROUND: Bronchopleural fistula (BPF) is a relatively rare complication after various types of pulmonary resection. The double-sided mushroom-shaped occluder (Amplatzer device, AD) has been gradually used for BPF blocking due to its reliable blocking effect. We have improved the existing AD implantation methods to facilitate clinical use and named the new approach Sheath-free method (SFM). The aim of the present report was to explore the reliability and advantages of the SFM in AD implantation. METHODS: We improved the existing implantation methods by abandoning the sheath of the AD and using the working channel of the bronchoscope to directly store or release the AD without general anesthesia, rigid bronchoscopy, fluoroscopy, or bronchography. A total of 6 patients (5 men and 1 woman, aged 66.67 ± 6.19 years [mean ± SD]) had BPF blocking and underwent the SFM in AD implantation. RESULTS: AD implantation was successfully performed in all 6 patients with the SFM, 4 persons had a successful closure of the fistula, one person died after few days and one person did not have a successful closure of the fistula. The average duration of operation was 16.17 min (16.17 ± 4.67 min [mean ± SD]). No patients died due to operation complications or BPF recurrence. The average follow-up time was 13.2 months (range 10-17 months). CONCLUSION: We observed that the SFM for AD implantation-with accurate device positioning and a clear field of vision-is efficient and convenient. The AD is effective in BPF blocking, and could contribute to significantly improved symptoms of patients.