31 research outputs found
SCATTEROMETRY OF 50 NM HALF PITCH FEATURES
Metrology technologies are an essential adjunct to Integrated Circuit (I.C.) Semiconductor manufacturing. Scatterometry, an optical metrology, was chosen to measure 50 nm half pitch feature structures. A bread-board scatterometry system has been assembled to provide a non-contact, non-destructive, accurate and flexible measurement. A real-time, on-line scatterometry system has also been demonstrated and proven to provide a high throughput measurement.
Three different types of samples have been measured using the scatterometry setup. The wire-grid polarizer (WGP) sample has been made by Jet and Flash Nanoimprint Lithography with ~100 nm pitch and ~50 nm wide ~200 nm tall Al gratings on fused silica substrates. One of the resist grating samples has been made by Roll-to-Roll Nanoimprint Lithography with ~130 nm pitch and ~65 nm wide ~100 nm tall resist gratings on polycarbonate substrate. The other resist grating samples have been made by Immersion Interference Lithography with ~80 nm pitch and ~70 nm tall resist gratings on silicon substrate.
For the WGP, four wavelengths (244 nm, 405 nm, 633 nm and 982 nm) were used to study the dependence of the parametric scatterometry on a function of the wavelength to sample pitch ratio ( /p: from 2.4 to 9.8). Results show that even for a laser wavelength ten times larger than the sample pitch, scatterometry can still provide the characteristic structure information. The definition of the grating structure in the simulation has improved from a simple trapezoidal structure to a more complicated model with top rounding structure and an Al2O3 âskinâ. With a better model and definition of the structure, simulation results have been closer to measurement results for all four wavelengths and the parameter sets present a very close results from scatterometry measurements. For the resist grating samples, scatterometry has less sensitivity because of lower index contrast than WGP, but a 405 nm laser source can still provide effective measurement on ~100 nm pitch resist samples. The scatterometry results are also sensitive to inhomogeneity of the resist sample and show a capability for classifying different types of macroscopic defects.
A model-based limitation study for both WGP and resist grating shows the fundamental limits of scatterometry for different materials and structures based on current noise levels. We have simulated a reducing linewidth and height of gratings with fixed pitch and the conditions with scaling the entire grating structure and have demonstrated that the potential capability of scatterometry can approach down to 10 nm feature size with a 405 nm laser
Evaluating the impact of urban landscape elements on the sense of security and local belonging-case study: Tongdejie, China
Introduction: The urban landscape is a pivotal element shaping the urban space and significantly influences its desirability or undesirability. It has a profound connection with people and their living environment, playing a crucial role in providing identity and a sense of peace to citizens. As urbanization expands and population density increases, the importance of security as a basic need within the urban structure becomes even more significant. A confusing, unattractive, or monotonous urban space can adversely affect citizensâ feelings and reduce their sense of security.Methods: In this research, we investigated the relationship between urban landscape components and the sense of local belonging, as well as the relationship between the sense of security and the urban landscape. We sought to understand how the design and planning of the urban landscape can have a positive impact on urban life and increase citizensâ sense of belonging to the city and its surroundings.Results: Our findings revealed a positive and significant correlation between the sense of local belonging and the sense of security. Living in a safe, attractive, and desirable environment fosters and strengthens feelings of belonging to the environment. This strengthening of the sense of belonging increases residentsâ satisfaction and enhances the quality of life in cities.Discussion: The urban landscape serves as a powerful tool that, when optimally designed, can positively influence urban life and enhance citizensâ sense of belonging to their city and its surrounding environment. By prioritizing security and creating aesthetically pleasing and engaging urban spaces, cities can significantly improve the well-being and quality of life of their residents
Characterization of a multidrug-resistant porcine Klebsiella pneumoniae sequence type 11 strain coharboring blaKPC-2 and fosA3 on two novel hybrid plasmids
The occurrence of carbapenemase-producing Enterobacteriaceae (CPE) poses a considerable risk for public health. The gene for Klebsiella pneumoniae carbapenemase-2 (KPC-2) has been reported in many countries worldwide, and KPC-2-producing strains are mainly of human origin. In this study, we identified two novel hybrid plasmids that carry either blaKPC-2 or the fosfomycin resistance gene fosA3 in the multiresistant K. pneumoniae isolate K15 of swine origin in China. The blaKPC-2-bearing plasmid pK15-KPC was a fusion derivative of an IncF33:Aâ:Bâ incompatibility group (Inc) plasmid and chromosomal sequences of K. pneumoniae (CSKP). A 5-bp direct target sequence duplication (GACTA) was identified at the boundaries of the CSKP, suggesting that the integration might have been due to a transposition event. The blaKPC-2 gene on pK15-KPC was in a derivative of ÎTn6296-1. The multireplicon fosA3-carrying IncN-IncR plasmid pK15-FOS also showed a mosaic structure, possibly originating from a recombination between an epidemic fosA3-carrying pHN7A8-like plasmid and a pKPC-LK30-like IncR plasmid. Stability tests demonstrated that both novel hybrid plasmids were stably maintained in the original host without antibiotic selection but were lost from the transformants after approximately 200 generations. This is apparently the first description of a porcine sequence type 11 (ST11) K. pneumoniae isolate coproducing KPC-2 and FosA3 via pK15-KPC and pK15-FOS, respectively. The multidrug resistance (MDR) phenotype of this high-risk K. pneumoniae isolate may contribute to its spread and its persistence
Direct field-to-pattern monolithic design of holographic metasurface via residual encoder-decoder convolutional neural network
Complex-amplitude holographic metasurfaces (CAHMs) with the flexibility in modulating phase and amplitude profiles have been used to manipulate the propagation of wavefront with an unprecedented level, leading to higher image-reconstruction quality compared with their natural counterparts. However, prevailing design methods of CAHMs are based on Huygens-Fresnel theory, meta-atom optimization, numerical simulation and experimental verification, which results in a consumption of computing resources. Here, we applied residual encoder-decoder convolutional neural network to directly map the electric field distributions and input images for monolithic metasurface design. A pretrained network is firstly trained by the electric field distributions calculated by diffraction theory, which is subsequently migrated as transfer learning framework to map the simulated electric field distributions and input images. The training results show that the normalized mean pixel error is about 3% on dataset. As verification, the metasurface prototypes are fabricated, simulated and measured. The reconstructed electric field of reverse-engineered metasurface exhibits high similarity to the target electric field, which demonstrates the effectiveness of our design. Encouragingly, this work provides a monolithic field-to-pattern design method for CAHMs, which paves a new route for the direct reconstruction of metasurfaces
Identification of Major QTLs Associated With First Pod Height and Candidate Gene Mining in Soybean
First pod height (FPH) is a quantitative trait in soybean [Glycine max (L.) Merr.] that affects mechanized harvesting. A compatible combination of the FPH and the mechanized harvester is required to ensure that the soybean is efficiently harvested. In this study, 147 recombinant inbred lines, which were derived from a cross between âDongnong594â and âCharlestonâ over 8 years, were used to identify the major quantitative trait loci (QTLs) associated with FPH. Using a composite interval mapping method with WinQTLCart (version 2.5), 11 major QTLs were identified. They were distributed on five soybean chromosomes, and 90 pairs of QTLs showed significant epistatic associates with FPH. Of these, 3 were main QTL Ă main QTL interactions, and 12 were main QTL Ă non-main QTL interactions. A KEGG gene annotation of the 11 major QTL intervals revealed 8 candidate genes related to plant growth, appearing in the pathways K14486 (auxin response factor 9), K14498 (serine/threonine-protein kinase), and K13946 (transmembrane amino acid transporter family protein), and 7 candidate genes had high expression levels in the soybean stems. These results will aid in building a foundation for the fine mapping of the QTLs related to FPH and marker-assisted selection for breeding in soybean
Color Calibration for Colorized Vision System with Digital Sensor and LED Array Illuminator
Color measurement by the colorized vision system is a superior method to achieve the evaluation of color objectively and continuously. However, the accuracy of color measurement is influenced by the spectral responses of digital sensor and the spectral mismatch of illumination. In this paper, two-color vision system illuminated by digital sensor and LED array, respectively, is presented. The Polynomial-Based Regression method is applied to solve the problem of color calibration in the sRGB and CIEââLâaâbâ color spaces. By mapping the tristimulus values from RGB to sRGB color space, color difference between the estimated values and the reference values is less than 3ÎE. Additionally, the mapping matrix ΊRGBâsRGB has proved a better performance in reducing the color difference, and it is introduced subsequently into the colorized vision system proposed for a better color measurement. Necessarily, the printed matter of clothes and the colored ceramic tile are chosen as the application experiment samples of our colorized vision system. As shown in the experimental data, the average color difference of images is less than 6ÎE. It indicates that a better performance of color measurement is obtained via the colorized vision system proposed
Deep Learning with Transformer or Convolutional Neural Network in the Assessment of Tumor-Infiltrating Lymphocytes (TILs) in Breast Cancer Based on US Images: A Dual-Center Retrospective Study
This study aimed to explore the feasibility of using a deep-learning (DL) approach to predict TIL levels in breast cancer (BC) from ultrasound (US) images. A total of 494 breast cancer patients with pathologically confirmed invasive BC from two hospitals were retrospectively enrolled. Of these, 396 patients from hospital 1 were divided into the training cohort (n = 298) and internal validation (IV) cohort (n = 98). Patients from hospital 2 (n = 98) were in the external validation (EV) cohort. TIL levels were confirmed by pathological results. Five different DL models were trained for predicting TIL levels in BC using US images from the training cohort and validated on the IV and EV cohorts. The overall best-performing DL model, the attention-based DenseNet121, achieved an AUC of 0.873, an accuracy of 79.5%, a sensitivity of 90.7%, a specificity of 65.9%, and an F1 score of 0.830 in the EV cohort. In addition, the stratified analysis showed that the DL models had good discrimination performance of TIL levels in each of the molecular subgroups. The DL models based on US images of BC patients hold promise for non-invasively predicting TIL levels and helping with individualized treatment decision-making
Separation and Enrichment of Three Coumarins from Angelicae Pubescentis Radix by Macroporous Resin with Preparative HPLC and Evaluation of Their Anti-Inflammatory Activity
In order to enrich and separate three coumarins (columbianetin acetate, osthole and columbianadin) from Angelicae Pubescentis Radix (APR), an efficient method was established by combining macroporous resins (MARs) with preparative high-performance liquid chromatography (PHPLC). Five different macroporous resins (D101, AB-8, DA-201, HP-20 and GDX-201) were used to assess the adsorption and desorption characteristics of three coumarins. The result demonstrated that HP-20 resin possessed the best adsorption and desorption capacities for these three coumarins. Moreover, the adsorption dynamics profiles of three coumarins were well fitted to the pseudo second order equation (R2 > 0.99) for the HP-20 resin. The adsorption process was described by the three isotherms models including Langmuir (R2 > 0.98, 0.046 ≤ RL ≤ 0.103), Freundlich (R2 > 0.99, 0.2748 ≤ 1/n ≤ 0.3103) and Dubinin Radushkevich (R2 > 0.97). The contents of columbianetin acetate, osthole and columbianadin in the product were increased 10.69-fold, 19.98-fold and 19.68-fold after enrichment, respectively. Three coumarins were further purified by PHPLC and the purities of them reached above 98%. Additionally, the anti-inflammatory effects of these three coumarins were assessed by Lipopolysaccharide (LPS)-induced RAW 264.7 cells. It was found that the production of NO and MCP-1 was obviously inhibited by three coumarins. Columbianetin acetate, osthole and columbianadin could be used as potentially natural anti-inflammatory ingredients in pharmaceutical products. It was concluded that the new method combining MARs with PHPLC was efficient and economical for enlarging scale separation and enrichment of columbianetin acetate, osthole and columbianadin with anti-inflammatory effect from the APR extract