In finger vein verification, the most important and challenging part is to robustly extract finger vein patterns from low-contrast infrared finger images with limited a priori knowledge. Although ...recent convolutional neural network (CNN)-based methods for finger vein verification have shown powerful capacity for feature representation and promising perspective in this area, they still have two critical issues to address. First, these CNN-based methods unexceptionally utilize fully connected layers, which restrict the size of finger vein images to process and increase the processing time. Second, the capacity of CNN for feature representation generally suffers from the low quality of finger vein ground-truth pattern maps for training, particularly due to outliers and vessel breaks. To address these issues, in this paper, we propose a novel approach termed FV-GAN to finger vein extraction and verification, based on generative adversarial network (GAN), as the first attempt in this area. Unlike the CNN-based methods, FV-GAN learns from the joint distribution of finger vein images and pattern maps rather than the direct mapping between them, with the aim at achieving stronger robustness against outliers and vessel breaks. Moreover, FV-GAN adopts fully convolutional networks as the basic architecture and discards fully connected layers, which relaxes the constraint on the input image size and reduces the computational expenditure for feature extraction. Furthermore, we design an adversarial training strategy and propose a hybrid loss function for FV-GAN. The experimental results on two public databases show significant improvement by FV-GAN in finger vein verification in terms of both verification accuracy and equal error rate.
Tunable terahertz optical dual-functional slow light reflector based on gold-graphene metamaterials has been designed and the proposed structure can achieve a good optical reflection effect and slow ...light effect. The tunable function can be dynamically controlled by applying a voltage to the gold and it can achieve a good effect for selecting reflection band. In more detail, the gold in this device can enable us to dynamically tune the Fermi level of graphene, thus this device can achieve a good tunable effect. Compared with other structures, the graphene monolayer in this structure is simpler and forms a complete band distribution, laying a solid foundation for the subsequent implementation of the device. Through the derivation and analysis of the optical equivalent-cavity coupled mode theory, the theoretical fitting transmission and reflection of this device can be obtained, and they are in good agreement with the numerical results. Furthermore, the slow light effect of this device has been analyzed and it is found that this device has a better slow light performance. This investigation is expected to provide a theoretical basis for the realization of tunable slow light reflectors.
Subsurface damage (SSD) generated during the grinding process directly affects the optical quality and the service life of optical components. It is of great significance to accurately predict and ...effectively control the depth of the SSD layer of the ground workpiece. However, most of the existing SSD depth prediction models are based on quasi-static and room temperature conditions. This paper presented a prediction model of SSD depth, which considered the combined effect of local strain rate and temperature on the SSD generation during grinding process. The variation of strain and strain rate in the local shear zone of an average abrasive grit on the grinding wheel was analyzed, considering the dynamic density of abrasive grits; Strain rate effect of the material was described by introducing a dynamic fracture toughness KID, which would increase with the strain rate; Grinding zone temperature and especially the temperature on the abrasive grits were analyzed. Combining the strain rate effect and temperature effect, a thermodynamic fracture toughness KIDT model was further developed. On the basis of classic brittle material crack system and the kinematics of grinding, the SSD prediction model considering the dynamic variation of mechanical properties in grinding process was derived. The effects of local strain rate and temperature in grinding of BK7 optical glass were systematically studied under different grinding wheel speeds. The predicted SSD values using a conventional static model and current models considering the strain rate or grinding temperature effect or both, were compared with the measured values. The predicted SSD values using the theoretical model including both the strain rate and grinding temperature effects, agree well with the measured values. The proposed model therefore is anticipated to be meaningful to understand of the SSD of hard and brittle materials involved in a precision grinding process.
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Novel Li2SnO3:Mn4+ red-emitting phosphor is synthesized by high-temperature solid-state reaction method in air. Emission band of Li2SnO3:Mn4+ phosphor within the range 620–760 nm is attributed to the ...2E → 4A2 electron transition of Mn4+ ion. Excitation bands peaking at 330, 395, and 480 nm are attributed to O2- → Mn4+ charge transfer and 4A2 → (4T1, 2T1, and 4T2) transitions of Mn4+ ion, respectively. The optimal Mn4+ concentration is ∼0.4 mol% and the corresponding quantum efficiency and lifetime are ∼42.3% and 16.3 μs. The influences of temperature and Mn4+ concentration to emission intensity are discussed and analysized. Lifetime data and time resolved spectra confirm that there is only a single type of Mn4+ ion luminescent center in Li2SnO3:Mn4+ phosphor. The influences of the crystal field and the “Mn4+-ligand” bonding to luminescence properties of Mn4+ ion are summaried and analysized. The luminous mechanism is explained via Tanabe-Sugano energy level diagram and the configuration coordinate diagram of Mn4+ in the octahedron. The results indicate that Li2SnO3:Mn4+ phosphor has a hope to be used as red phosphor candidate for solid-state lighting.
PLE and PL spectra of novel Li2SnO3:Mn4+ red-emitting phosphor, the picture of Li2SnO3:Mn4+ phosphor under 365 nm UV lamp, the unit cell of Li2SnO3, and LED devices based on blue (∼460 nm) chip + Li2SnO3:0.4%Mn4+ phosphor without or with YAG:Ce phosphor. Display omitted
•Novel Li2SnO3:Mn4+ red-emitting phosphor is synthesized by solid-state reaction method.•Emission band peaking at ∼658 nm is observed within the range 620–760 nm.•Red and white LED devices are fabricated by an encapsulation technology in the lab.•The luminous mechanism is analyzed by the configurational coordinate diagram of Mn4+ ion.
A systematic study has been performed to investigate the topography and wear characteristics of diamond wheel at different processing stages in grinding of N-BK7 optical glass, including ...manufacturing, truing, sharpening and grinding. The morphology of the abrasive grains, protrusion height and density were quantitatively evaluated. Moreover, the wear modes of diamond grits, including micro-fracture, macro-fracture, pull-outs and attritious wear, were analyzed based on a comprehensive wear model. The topography disparity at different processing stages is attributed to the microscopic difference of wear mechanism of diamond grits. Interestingly, three wear regions (initial/steady/deteriorated wear) occur during multi-pass grinding, and the most dominant wear behaviors of these three regions are separately macro-fracture and pull-out, micro-fracture and attritious wear, pull-out and wheel loading.
•The diamond wheel topography at different processing stages possess its own characteristics.•The paper quantitatively evaluated the abrasive grain morphology, protrusion height and density of diamond wheel.•The wear behavior of diamond wheel at different processing stages is analyzed based on a comprehensive wear model.•There are three wear regions (initial/steady/deteriorated wear) during multi-pass grinding of N-BK7 optical glass.
Our previous study indicated that Casein kinase 2 interacting protein-1 (CKIP-1) could promote the activation of the nuclear factor E2-related factor 2 (Nrf2)/ antioxidant response element (ARE) ...pathway, playing a significant role in inhibiting the fibrosis of diabetic nephropathy (DN). However, the underlying mechanism is still unknown. Here, we investigated whether CKIP-1 affects the polyubiquitination of Nrf2 and its cytosolic inhibitor kelch like ECH-associated protein 1 (Keap1) via mediating Smad ubiquitylation regulatory factor-1 (Smurf1) to promote the activation of the Nrf2/ARE signaling and resist high glucose (HG)-induced renal fibrosis in glomerular mesangial cells (GMCs) and diabetic mice kidneys. Results showed that the expression of Smurf1 increased in HG-induced GMCs, with a paramount upregulation at 1h. Overexpression of wild-type Smurf1 plasmid further promoted the HG-induced the over-production of fibronectin (FN) and intercellular adhesionmolecule-1 (ICAM-1), and depletion of Smurf1 dramatically reduced the expression of FN and ICAM-1. Overexpression of CKIP-1 decreased the K48-linked polyubiquitination and increased the K63-linked polyubiquitination of Nrf2 as well as enhanced the K48-linked polyubiquitination and reduced K63-linked polyubiquitination of Keap1, promoting the activation of the Nrf2/ARE pathway. Overexpression of Smurf1 increased the K48-linked polyubiquitination and decreased the K63-linked polyubiquitination of Nrf2, and down-regulated the K48-linked polyubiquitination and up-regulated the K63-linked polyubiquitination of Keap1, inhibiting the activation of the Nrf2/ARE pathway. CKIP-1 promoted the degradation of Smurf1 by increasing the ubiquitination of Smurf1. Treatment of CKIP-1 adenovirus infection reduced the Smurf1 levels, promoted the activation of the Nrf2/ARE pathway as well as suppressed the production of reactive oxygen species (ROS), and then improved the failure of renal function of diabetic mice. Experiments above suggested that CKIP-1 affects the polyubiquitination of Nrf2 and Keap1 and promotes the Nrf2-ARE pathway through down-regulating Smurf1 to resist HG-induced up-regulation of FN and ICAM-1 in GMCs and diabetic mice kidneys.
•Smurf1 involves in the progress of DN because of its ubiquitin ligase activity.•Both Nrf2 and Keap1 can be polyubiquitinated.•CKIP-1 affects the polyubiquitination of Nrf2 and Keap1 via Smurf1.•CKIP-1 adenovirus improved antioxidant ability and renal failure of diabetic mice.
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Lung cancer is the leading cause of cancer-related deaths worldwide, with 50-70% of patients suffering from bone metastasis. Accumulating evidence has demonstrated that miRNAs are involved in cell ...proliferation, migration, and invasion in malignancy, such as lung cancer bone metastasis. In the present study, we demonstrated that reduced miR-192-5p and increased TRIM44 levels were associated with the proliferation, migration and invasion of lung cancer. Furthermore, the potential functions of miR-192-5p were explored in A549 and NCI-H1299 cells. We found that miR-192-5p upregulation suppressed tumour behaviours in lung cancer cells. To further investigate whether miR-192-5p is associated with TRIM44, we used TargetScan software to predict the binding site between miR-192-5p and TRIM44. Luciferase activity assays were performed to verify this prediction. In addition, the significant role of miR-192-5p in negatively regulating TRIM44 expression was manifested by our research group. our results suggest that miR-192-5p inhibited the proliferation, migration and invasion of lung cancer through TRIM44.
Abstract
A very simple optical tunable device, which can realize multiple functions of frequency selection, reflection and slow light, is presented at the investigation. The proposed device is ...constructed by a periodic grating-like structure. There are two dielectrics (graphene and silicon) in a period of the equivalent grating. The incident light will strongly resonate with the graphene of electrostatic doping, forming an evanescent wave propagating along the surface of graphene, and this phenomenon is the surface plasmon. Under constructive interference of the polaritons, a unique plasmonic induced transparency phenomenon will be achieved. The induced transparency produced by this device can be well theoretically fitted by the bright and dark mode of optical equivalent cavity which can be called coupled mode theory. This theory can well analyze the influence of various modes and various losses between the function of this device. The device can use gate voltages for electrostatic doping in order to change the graphene carrier concentration and tune the optical performance of the device. Moreover, the length of the device in
y
-direction is will be much larger than the length of single cycle, providing some basis for realizing the fast tunable function and laying a foundation for the integration. Through a simulation and calculation, we can find that the group index and group delay of this device are as high as 515 and 0.257 picoseconds (ps) respectively, so it can provide a good construction idea for the slow light device. The proposed grating-like metamaterial structure can provide certain simulation and theoretical help for the optical tunable reflectors, absorbers, and slow light devices.
Diabetic nephropathy (DN) is rapidly becoming the leading cause of end-stage renal disease worldwide and a major cause of morbidity and mortality in patients of diabetes. The main pathological change ...of DN is renal fibrosis. Paeonol (PA), a single phenolic compound extracted from the root bark of Cortex Moutan, has been demonstrated to have many potential pharmacological activities. However, the effects of PA on DN have not been fully elucidated. In this study, high glucose (HG)-treated glomerular mesangial cells (GMCs) and streptozotocin (STZ)-induced diabetic mice were analyzed in exploring the potential mechanisms of PA on DN. Results
showed that: (1) PA inhibited HG-induced fibronectin (FN) and ICAM-1 overexpressions; (2) PA exerted renoprotective effect through activating the Nrf2/ARE pathway; (3) Sirt1 mediated the effects of PA on the activation of Nrf2/ARE pathway. What is more, in accordance with the
results, significant elevated levels of Sirt1, Nrf2 and downstream proteins related to Nrf2 were observed in the kidneys of PA treatment group compared with model group. Taken together, our study shows that PA delays the progression of diabetic renal fibrosis, and the underlying mechanism is probably associated with regulating the Nrf2 pathway. The effect of PA on Nrf2 is at least partially dependent on Sirt1 activation.
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