Predicting Vulnerable Carotid Plaques by Detecting Wall Shear Stress Based on Ultrasonic Vector Flow Imaging.

OBJECTIVE: Carotid plaque vulnerability is a significant factor in the risk of cardio-cerebrovascular events, with intraplaque neovascularization (IPN) being a crucial characteristic of plaque vulnerability. This study investigates the value of ultrasound vector flow imaging (V-Flow) for measuring carotid plaque wall shear stress (WSS) in predicting the extent of IPN. METHODS: We enrolled 140 patients into three groups: 53 in the plaque group (72 plaques), 23 in the stenosis group (27 plaques), and 64 in the control group. V-Flow was employed to measure WSS parameters, including the average WSS (WSS Mean) and the maximum WSS (WSS Max), across three plaque locations: mid-upstream, maximum thickness, and mid-downstream. Contrast-enhanced ultrasound (CEUS) was utilized in 76 patients to analyze IPN and its correlation with WSS parameters. RESULTS: 1. WSS Max in the stenosis group was significantly higher than that in the control and plaque groups at the maximum thickness part (p < 0.05); WSS Mean in the stenosis group was significantly lower than that in the control group at the mid-upstream and mid-downstream segments (p < 0.05); and WSS Mean in the plaque group was significantly lower than that of the control group at all three locations (p < 0.05). 2. CEUS revealed that plaques with neovascularization enhancement exhibited significantly higher WSS values (p < 0.05), with a positive correlation between WSS parameters and IPN enhancement grades, particularly WSS Max at the thickest part (r = 0.508). 3. ROC curve analysis of WSS parameters for evaluating IPN showed that the efficacy of WSS Max in evaluating IPN was better than that of WSS Mean (p < 0.05), with an AUC of 0.7762, 0.6973; 95% CI of 0.725 - 0.822, 0.642 - 0.749, respectively; Cut-off was 4.57 Pa, 1.12 Pa; sensitivity was 74.03%, 63.64%; specificity was 75.00%, 68.18%. CONCLUSIONS: V-Flow effectively measures WSS in carotid plaques. WSS Max provides a promising metric for assessing IPN, offering potential insights into plaque characteristics and showing some potential in predicting plaque vulnerability.

Functional reconstruction of the basal ganglia neural circuit by human striatal neurons in hypoxic-ischaemic injured brain.

Perinatal hypoxic-ischaemic encephalopathy is the leading cause of neonatal death and permanent neurological deficits, while the basal ganglia is one of the major nuclei that is selectively and greatly affected in the brains of hypoxic-ischaemic encephalopathy patients, especially in severe cases. Human embryonic stem cell-derived neurons have shown great potential in different types of brain disorders in adults. However, it remains unknown whether and how grafted human embryonic stem cell-derived neurons can repair immature brains with hypoxic-ischaemic encephalopathy. Here, by administrating genetically labelled human embryonic stem cell-derived striatal neural progenitors into the ipsilateral striatum of hypoxic-ischaemic encephalopathy-injured mice, we found that the grafted cells gradually matured into GABA spiny projection neurons morphologically and electrophysiologically, and significantly rescued the area loss of hypoxic-ischaemic encephalopathy-injured brains. Intriguingly, using immunohistochemical staining combined with enhanced ascorbate peroxidase-based immunoelectron microscopy and rabies virus-mediated trans-synaptic tracing, we show that the grafts start to extend axonal projections to the endogenous target areas (globus pallidus externa, globus pallidus internus, substantia nigra), form synapses with host striatal, globus pallidus and nigra neurons, and receive extensive and stable synaptic inputs as early as 2 months post-transplantation. Importantly, we further demonstrated functional neural circuits re-established between the grafted neurons and host cortical, striatal and substantial nigra neurons at 3-6 months post-transplantation in the hypoxic-ischaemic encephalopathy-injured brain by optogenetics combined with electrophysiological recording. Finally, the transplanted striatal spiny projection neurons but not spinal GABA neurons restored the motor defects of hypoxic-ischaemic encephalopathy, which were reversed by clozapine-N-oxide-based inhibition of graft function. These findings demonstrate anatomical and functional reconstruction of the basal ganglia neural circuit including multiple loops by striatal spiny projection neurons in hypoxic-ischaemic encephalopathy-injured immature brains, which raises the possibility of such a cell replacement therapeutic strategy for hypoxic-ischaemic encephalopathy in neonates.

Analysis of related factors influencing postoperative recurrence of adenomyosis treated with HIFU.

OBJECTIVE: To analyze the efficacy of high-intensity focused ultrasound (HIFU) for adenomyosis and postoperative recurrence and its influencing factors. METHODS: Clinical and follow-up data of 308 patients with adenomyosis who were treated with HIFU in Haifu Center, Affiliated Hospital of Chengdu University of Traditional Chinese Medicine from September 2017 to January 2022 were retrospectively analyzed. The recurrence of adenomyosis and the efficacy of HIFU at 6 months after surgery were followed up. To explore factors influencing postoperative prognosis and recurrence, the following variables were analyzed: patients' age, course of disease, gravidity and parity, size of the uterus, duration of HIFU, duration of irradiation, treatment intensity, dysmenorrhea score, time of follow-up, combined treatment of traditional Chinese medicine (TCM), western medicine adjuvant treatment, lesion location and type, and menorrhagia. RESULTS: Among the 308 patients, 238 (77%) were followed up from 6 to 36 months, with an average follow-up time of 15.24 ± 9.97 months. The other 70 (23%) were lost to follow-up. At 6-month after surgery, efficacy rates of dysmenorrhea and menorrhagia management were 86.7% and 89.3%, respectively. Postoperative recurrence rates were 4.8% (1-12 months), 9.0% (12-24 months), and 17.0% (24-36 months) for dysmenorrhea; and 6.3% (1-12 months), 2.4% (12-24 months), and 12.2% (24-36 months) for menorrhagia. Multivariate logistic regression analyses showed that parity (P = 0.043, OR = 1.773, 95% CI 1.018-3.087), uterine size (P = 0.019, OR = 1.004, 95% CI 1.001-1.007), combined treatment of TCM (P = 0.047, OR = 1.846, 95% CI 1.008-3.381), diffuse lesion type (P = 0.013, OR = 0.464, 95% CI 0.254-0.848) and ablation rate (P = 0.015, OR = 0.481, 95%CI 0.267-0.868) were prognostic factors (P < 0.05). Age, course of disease, gravidity, duration of HIFU, duration of irradiation, treatment intensity, preoperative dysmenorrhea score, time of follow-up, western medicine adjuvant therapy, lesion location, and preoperative menstrual volume had no effect on prognosis (P > 0.05). CONCLUSION: HIFU can effectively relieve dysmenorrhea and reduce menstrual volume in patients with adenomyosis. Parity, uterine size, lesion type (diffuse), and ablation rate are risk factors for symptom recurrence after HIFU, while the combination of TCM therapy is a protective factor for relapse. We, therefore, recommend TCM in the adjuvant setting after HIFU according to patient condition.

Pan-cancer spatially resolved single-cell analysis reveals the crosstalk between cancer-associated fibroblasts and tumor microenvironment.

Cancer-associated fibroblasts (CAFs) are a heterogeneous cell population that plays a crucial role in remodeling the tumor microenvironment (TME). Here, through the integrated analysis of spatial and single-cell transcriptomics data across six common cancer types, we identified four distinct functional subgroups of CAFs and described their spatial distribution characteristics. Additionally, the analysis of single-cell RNA sequencing (scRNA-seq) data from three additional common cancer types and two newly generated scRNA-seq datasets of rare cancer types, namely epithelial-myoepithelial carcinoma (EMC) and mucoepidermoid carcinoma (MEC), expanded our understanding of CAF heterogeneity. Cell-cell interaction analysis conducted within the spatial context highlighted the pivotal roles of matrix CAFs (mCAFs) in tumor angiogenesis and inflammatory CAFs (iCAFs) in shaping the immunosuppressive microenvironment. In patients with breast cancer (BRCA) undergoing anti-PD-1 immunotherapy, iCAFs demonstrated heightened capacity in facilitating cancer cell proliferation, promoting epithelial-mesenchymal transition (EMT), and contributing to the establishment of an immunosuppressive microenvironment. Furthermore, a scoring system based on iCAFs showed a significant correlation with immune therapy response in melanoma patients. Lastly, we provided a web interface ( https://chenxisd.shinyapps.io/pancaf/ ) for the research community to investigate CAFs in the context of pan-cancer.

Crosstalk suppression in CMOS terahertz detectors by using a mushroom-like AMC structure.

The suppression of the crosstalk in a CMOS THz detector is essential for enhancing the performance of detector arrays; however, it presents several technical challenges at the chip level. In this paper, a novel structure featuring a mushroom-like artificial magnetic conductor (M-AMC) is developed to suppress the crosstalk between CMOS THz detectors with on-chip antennas. Three-dimensional simulation results show that the M-AMC structure, which is designed by metal Al and doped-Si materials in the CMOS process, not only reduces the transmission coefficient of the electromagnetic wave between adjacent pixels but also enhances the electric field of the target pixels. A 0.65 THz detector array with a M-AMC structure based on the on-chip antenna was fabricated. Experimental results present that after implanting the M-AMC structure, the noise equivalent power (NEP) at the central frequency of pixels significantly decreases by 315.5%. Moreover, the distribution of NEP becomes more uniform, as evidenced by a reduction in the standard deviation coefficient of 26.3%. This demonstrates the effectiveness of the method in suppressing crosstalk and improving the responsivity of CMOS THz detectors, which can be used for high-performance THz detector arrays.

Synthesis of Urchin-like Ni@NP@NCP Composites with Three Solvothermal Systems for Highly Efficient Overall Seawater Splitting.

In this work, an urchin-like Ni@Ni2P@NiCoP (Ni@NP@NCP) composite was prepared on nickel foam by a simple hydrothermal treatment process. Using the prepared NiO nanosheets as templates, the NiCo precursor was prepared in the presence of three solvothermal systems of water/dimethylformamide (DMF)/dimethyl sulfoxide (DMSO) by the hydrothermal process. After mixing and calcining with sodium hypophosphite under a nitrogen atmosphere at a high temperature for phosphating, an urchin-like Ni@NP@NCP(F/SO/H) nanostructured catalyst was obtained with superior hydrogen evolution and oxygen evolution performance. To further explore their efficiency in seawater splitting. Ni@NP@NCP(F/SO/H) composites were used as the cathode and anode of an electrolytic cell, which delivered 1.822 V potential at 300 mA cm-2 in simulated seawater (1 M KOH and 0.5 M NaCl). This may provide an effective way of developing clean energy.

Two-step particle swarm optimization algorithm for effective deconvolution and resolution enhancement of various overlapping peaks.

RATIONALE: The existing particle swarm optimization (PSO) algorithms are only effective in deconvoluting the overlapping peaks in ion mobility spectra with fewer than four component peaks, which limits the applicability of these algorithms. METHODS: A high-performance two-step particle swarm optimization (TSPSO) algorithm was developed. Compared to the existing PSO algorithms, TSPSO can narrow the search ranges of all coefficients for the overlapping peaks through Gaussian model calculation, and thus can deconvolute various overlapping peaks with high accuracy, even for 30-component overlapping peaks. In addition, the TSPSO could be further applied to enhance the resolution of the spectra by narrowing the peak widths after the peak deconvolution. RESULTS: Simulated overlapping peaks were first used to evaluate the performance of TSPSO as compared to the dynamic inertia weight particle swarm optimization (DIWPSO) algorithm. The results showed that the profiles of the peaks deconvoluted by using TSPSO were more consistent with the original ones. The fitness values and the standard deviations of the fitness values from TSPSO were also at least an order of magnitude less than those from DIWPSO. By applying TSPSO, the overlapping peaks from both mass spectrometry (MS) and field asymmetric waveform ion mobility spectrometry (FAIMS) spectra can also be well deconvoluted. In addition, the resolutions of the MS and FAIMS spectra can be effectively enhanced after peak deconvolution. The enhanced spectra matched excellently with the experimental ones acquired at high-resolution modes. CONCLUSIONS: The experiment results convincingly demonstrate that the TSPSO algorithm is capable of both deconvoluting complex overlapping peaks and enhancing the spectrum resolution with high accuracy.

Forty years of development of salpingitis animal modeling.

This review summarizes and examines research in the area of salpingitis animal modeling in the last 40 years, focusing primarily on Chlamydia trachomatis animal models, which are the most numerous in the literature. Early animal models are examined, followed by a discussion of study parameters and their impact on modeling success, subsequent considerations of fertility measures in modeling, explorations of treatment options, and finally exploring recent directions with a brief discussion of models using other bacterial pathogens.

Resolution enhancement with highly curved illumination in ptychography.

By deducing a formula to compute a sample from recorded diffraction intensity directly and analytically, the relationship among the highest reachable resolution of the ptychographic iterative engine (PIE), its illumination angle, and its collection angle was discussed analytically. Curved illumination was then proposed to realize the resolution enhancement for PIE, and a corresponding computing algorithm was proposed to avoid an undersampling effect without increasing the size of the computing matrix, thus realizing speedy high-resolution PIE imaging with a simple experimental setup. While theoretical analysis was carried out, the feasibility of this proposed method was verified both numerically and experimentally.

Risk factors and a nomogram model for postoperative delirium in elderly gastric cancer patients after laparoscopic gastrectomy.

BACKGROUND: To evaluate the risk factors of postoperative delirium (POD) in elderly gastric cancer (GC) patients after laparoscopic gastrectomy and construct a predictive model. METHODS: Elderly GC patients undergoing laparoscopic gastrectomy were enrolled and grouped based on the status of POD development within postoperative 7 days. Independent risk factors were selected out by univariate and multivariate logistic regression analyses and then enrolled in the nomogram prediction model. RESULTS: A total of 270 elderly GC patients were enrolled, and POD occurred in 74 (27.4%) patients within postoperative 7 days. The results of multivariate regression analysis indicated that age (OR: 3.30, 95% CI: 1.41-6.85, P < 0.001), sleeping pills (OR: 1.87, 95% CI: 1.12-3.09, P = 0.012), duration of ICU stay (OR: 1.55, 95% CI: 1.02-2.37, P = 0.029), albumin/fibrinogen ratio (AFR) (OR: 1.74, 95% CI: 1.03-2.76, P = 0.019), and neutrophils/lymphocytes ratio (NLR) (OR: 2.12, 95% CI: 1.11-4.01, P = 0.016) were five independent risk factors for POD in elderly GC patients. The AUC of the constructed nomogram model based on these five factors was 0.807. CONCLUSIONS: This study highlighted that age, AFR, NLR, sleeping pills taking, and duration of ICU stay were independent risk factors for POD, and the nomogram model based on these factors could effectively predict POD in elderly GC patients.

Evaluation of Calu-3 cell lines as an in vitro model to study the inhalation toxicity of flavoring extracts.

This study aimed to evaluate the characteristics of Calu-3 cells as a model to examine the toxicological responses of inhalable substances. Calu-3 cells were grown to the confluence at an air-liquid interface (ALI) using a Transwell® permeable support system. The ALI resulted in biomimetic native bronchial epithelium displaying pseudostratified columnar epithelium with more microvilli and secretory vesicles. We further characterized and optimized the Calu-3 cell line model using ALI culturing conditions, immunolabeling of protein expression, ultrastructural analysis using scanning electron microscopy (SEM), and transepithelial electrical resistance (TEER) measurements, and then screened for the cytotoxicity of tobacco flavoring extracts. Calu-3 cells displayed dose-dependent responses when treated with the flavoring extract. Within 8-10 days, cell monolayers developed TEER ≥1000 Ω·cm2. During this time, Calu-3 cells exposed to flavoring extracts X01 and X06 exhibited a loss of cellular integrity and decreased ZO-1 and E-cadherin protein expression. In conclusion, we investigated the Calu-3 cell line culture conditions, culture time, and barrier integrity and tested the effect of six new synthetic tobacco flavoring extracts. Our data demonstrate that the Calu-3 human bronchial epithelial cell monolayer system is a potential in vitro model to assess the inhalation toxicity of inhalable substances.

Microbolometer with a salicided polysilicon thermistor in CMOS technology.

The metal-type microbolometers in CMOS technology normally suffer low resistivity and high thermal conductivity, limiting their performance and application areas. In this paper, we demonstrate a polysilicon microbolometer fabricated in 0.18 µm CMOS and post-CMOS processes. The detector is composed of a SiO2 absorber coupled with a salicided poly-Si thermistor that has a high resistivity of 1.37×10-4 Ω·cm and low thermal conductivity of 18 W/m·K. It is experimentally shown that the microbolometer with a 40 µm × 40 µm pixel size has a maximum responsibility and detectivity of 2.13×104 V/W and 2.33×109 cmHz1/2/W, respectively. The results are superior to the reported metal-type and diode-type microbolometers in the CMOS process and provide good potential for a low-cost, high-performance, uncooled microbolometer array for infrared imaging applications.

Effect of Saponin from Tupistra chinensis Baker on proliferation and apoptosis of ovarian cancer cells by Wnt/ß-Catenin pathway.

The present study aimed to investigate the molecular mechanism and the effect of Saponin from Tupistra chinensis Baker (STCB) on the proliferation and apoptosis of ovarian cancer cells. To investigate the inhibitory effect of STCB on the proliferation of ovarian cancer cells, SKOV3 cells were cultured and the methyl thiazolyl tetrazolium assay was used. Flow cytometry was also used to analyze the cell cycle distribution and apoptotic rate. Ki-67, cyclin D1, cleaved caspase-3, cleaved caspase-9, ß-catenin, and c-Myc protein expressions were detected by western blot. Ovarian cancer cells were treated with STCB and Wnt pathway activator lithium chloride (LiCl). These methods were also used to determine the proliferation, cell cycle distribution, and apoptosis of ovarian cancer cells. In STCB-treated group, the proliferation inhibition and apoptosis rate, the proportion of G0-G1 phase, and the expression level of cleaved caspase-3 and 9 of ovarian cancer cells were significantly increased. Similarly, the expression of Ki-67, cyclin D1, ß-catenin, and c-Myc were significantly decreased (p < .05). The results also showed that in STCB-LiCl-treated group, while the proliferation inhibition rate of ovarian cancer cells, the proportion of G0-G1 cells, the expression level of cleaved caspase-3 and 9, and the apoptosis rate (p < .05) were significantly decreased, the expression level of Ki-67, cyclin D1, ß-catenin, and c-Myc was significantly increased. STCB induced G0-G1 phase arrest, inhibited cell proliferation, and promoted apoptosis of ovarian cancer cells by inhibiting Wnt/ß-catenin pathway.

Investigation of a noise source and its impact on the photocurrent performance of long-wave-infrared InAs/GaSb type-II superlattice detectors.

Electrical noise significantly limits the detectivity of infrared photodiode detectors. In this paper, we investigated the dark current and noise spectra for long-wave-infrared InAs/GaSb type-II superlattice (T2SL) detectors to study the origin of noise under various work conditions. The temperature-dependent I-V characteristics reveal a turning point near 90 K, below which the dominant dark current mechanism changes from Shockley-Hall-Read generation current and diffusion current to shunt current and trap-assisted tunneling (TAT) current. The contribution of shunt and tunneling process to the total 1/f noise are analyzed by fitting the noise power spectral density at 77 K for detectors. It is found that the TAT current dominates the 1/f noise at the reverse bias stronger than -0.1 V, while shunt current exhibits a larger contribution at the reverse bias less than -0.1 V with the shunt noise coefficient αshunt of 5×10-8. Furthermore, the leakage routes related to the shunt process and their temperature dependence are illustrated by two-dimensional photocurrent mapping.

Comparative anti-inflammatory effect of curcumin at air-liquid interface and submerged conditions using lipopolysaccharide stimulated human lung epithelial A549 cells.

BACKGROUND: Inhalation of aerosolized drugs is a promising entry route for rapid and non-invasive therapeutics delivery to the lung. Curcumin exhibits potent anti-inflammatory properties, which are effective for use in lung diseases. The anti-inflammatory properties of curcumin have been widely studied in vitro with cells cultured in submerged conditions, however, the effectiveness using air-liquid interface (ALI) exposure is currently unknown. METHODS: The anti-inflammatory effect of curcumin under both ALI and submerged conditions was investigated in the present study. Lipopolysaccharide (LPS) stimulated A549 cells were exposed to curcumin under ALI (10-100 µM) using a dose-controlled air-liquid interface cell exposure (ALICE)-CLOUD system and submerged cell culture conditions (1-20 µM). The expression of pro-inflammatory cytokines (interleukin (IL)-6, IL-8), cell viability and cytotoxicity were studied for each exposure scenario. The cellular uptake behaviour of curcumin was studied with an equipotent cell-based dose (200 pmol/106 cell) at various time points up to 24 h. RESULTS: The ALI delivery profile proved to be rapid, efficient and reproducible. For the doses studied, no significant effect on cell viability and cytotoxicity were observed. ALI exposure of curcumin was more effective in reducing pro-inflammatory cytokines expression in lung epithelial cells compared with submerged cell cultures. Furthermore, rapid cellular uptake and higher intracellular doses were achieved by ALI conditions. CONCLUSIONS: The ALICE-CLOUD system combined with lung epithelial cells cultured under ALI conditions offers a reliable and relevant in vitro method for preclinical aerosolized drug screening. Curcumin might be a promising anti-inflammatory candidate drug for inhalation therapy of lung diseases.

Preoperative prognostic nutritional index predicts postoperative delirium in elderly patients after hip fracture surgery.

BACKGROUND: Postoperative delirium (POD) is a very common complication in elderly patients after hip fracture surgery, which has poorly understood pathophysiology. This study aimed to investigate potential risk factors for POD. METHODS: Elderly patients (aged ≥65 years) scheduled to undergo selective surgery in our hospital were consecutively recruited. Patient characteristics, preoperative laboratory tests and prognostic nutritional index (PNI) levels were compared between patients with or without POD. The risk factors for POD were evaluated by univariate and multivariate logistic regression analyses. Receiver operating characteristic (ROC) curve analysis was performed to evaluate the predictive value of PNI and age for POD. RESULTS: Fifty-seven of the 163 enrolled patient had suffered POD within postoperative day 7 with an incidence of 35.0%. Multivariate logistic analyses revealed that an advanced age (cut-off value: 71.5 years, sensitivity: 48.1%, specificity: 75.4%, odds ratio (OR): 3.24, 95% CI: 1.16-8.69, P = 0.026) and lower PNI level (cut-off value: 47.45, sensitivity: 86.0%, specificity: 51.9%, OR: 2.88, 95% CI: 1.25-6.64, P = 0.012) were two independent predictive factors associated with POD. According to the ROC curve analysis, preoperative PNI level was a predictor for POD with an area under the curve of 0.686 (95% CI: 0.604-0.767, P < 0.001). CONCLUSIONS: Advanced age and lower preoperative PNI level were significantly associated with POD in elderly patients after hip fracture surgery.

Spinal IL-36γ/IL-36R participates in the maintenance of chronic inflammatory pain through astroglial JNK pathway.

Emerging evidence indicates that spinal neuroinflammation contributes to the maintenance of chronic inflammatory pain. IL-36, as a novel member of the interleukin (IL)-1 super-family cytokines, plays an important role in inflammatory responses. The present study aimed to investigate the role of spinal IL-36 and IL-36 receptor (IL-36R) signaling in the pathology of chronic inflammatory pain. IL-36γ and IL-36R, but not IL-36α and IL-36ß, were persistently upregulated in the spinal cord of mice with intraplantar injections of complete Freund's adjuvant (CFA). Intrathecal administration of both IL-36R antagonist (IL-36Ra) and IL-36γ siRNA significantly attenuated CFA-induced chronic inflammatory pain behaviors. Furthermore, CFA-induced IL-36γ expression was mainly observed in spinal neurons whereas IL-36R was primarily expressed in spinal astrocytes. Additionally, the intrathecal injection of IL-36γ was sufficient to induce pain hypersensitivity and astrocyte activation in naive mice, and these effects could be inhibited by blocking c-Jun N-terminal kinase (JNK) phosphorylation. In vitro experiments also demonstrated that the IL-36γ could induce astrocytic JNK activation and inflammatory cytokines release, which was mediated by IL-36R. Finally, intrathecal injection of IL-36γ-activated astrocytes in a pJNK-dependent manner induced mechanical allodynia and thermal hyperalgesia in naive mice. Collectively, these findings reveal that the neuronal/astrocytic interaction in the spinal cord by which neuronally produced IL-36γ activates astrocytes via IL-36R-mediated JNK pathway is crucial for the maintenance of chronic inflammatory pain. Thus, IL-36γ/IL-36R-mediated astrocyte signaling may be a suitable therapeutic target for chronic inflammatory pain.

Dual-frequency CMOS terahertz detector with silicon-based plasmonic antenna.

Multi-frequency Terahertz (THz) detectors have shown great application potentials in THz imaging and sensing systems. For the first time to our knowledge, a novel dual-frequency THz detector with the stacked structure consisting of a silicon-based plasmonic antenna and a metal-based antenna in one compact unit is proposed and fabricated in standard CMOS technology. Compared with the metal antenna, the antenna based on heavy-doped poly-silicon materials enables the detector to excite localized surface plasmon resonance mode, making the effective absorption of the THz waves and thus resulting in the significant responsivity enhancement of the detector. The experimental results show a maximum voltage responsivity up to about 2000 V/W and 450 V/W, while the noise equivalence power is as low as 23 pW/Hz0.5 and 110 pW/Hz0.5 for the silicon antenna and metal antenna at the frequency of 220 GHz and 650 GHz, respectively. The presented dual-frequency detector can be easily implemented in a small size in favor of high-density array integration.

High-performance nanoporous-GaN metal-insulator-semiconductor ultraviolet photodetectors with a thermal oxidized ß-Ga2O3 layer.

We report on the high-performance nanoporous (NP) GaN-based metal-insulator-semiconductor (MIS) ultraviolet (UV) photodetectors (PDs) with a thermal oxidized ß-Ga2O3insulating layer. The devices show a high responsivity of 4.5×105 A/W and maximum external quantum efficiency of 1.55×108% at 360 nm under a 10 V applied bias, which are attributed to the trap-assisted tunneling induced internal gain mechanism. Correspondingly, a specific detectivity of 8.27×1015 Jones and excellent optical switching repeatability are also observed in our fabricated PDs. The NP-GaN/ß-Ga2O3 MIS UV PD may act as an excellent candidate for the application in UV photodetection due to the high performance and simple fabrication process.

Investigation of deep level defects on Beryllium compensation doping of In0.53Ga0.47As/GaAs0.49Sb0.51 type-II superlattice photodiodes.

In this paper, deep level transient spectroscopy (DLTS) characterization was performed on Beryllium compensation doping of InGaAs/GaAsSb type-II superlattice photodiode. Three electron traps with the energy levels located at Ec-0.11 eV (E1), Ec-0.28 eV (E2), Ec-0.17 eV (E3), and a hole trap situated at Ev + 0.25 eV (H1) were revealed. The position distribution and depth concentration of these traps in SL absorption region was also explored. Furthermore, the bandlike states (E2) and localized states (E1 and H1) of extended defects were confirmed by DLTS measurements as a function of the filling-pulse time, these traps as generation-recombination centers are responsible for dominant dark current.