A 1,000 Frames/s Programmable Vision Chip with Variable Resolution and Row-Pixel-Mixed Parallel Image Processors

A programmable vision chip with variable resolution and row-pixel-mixed parallel image processors is presented. The chip consists of a CMOS sensor array, with row-parallel 6-bit Algorithmic ADCs, row-parallel gray-scale image processors, pixel-parallel SIMD Processing Element (PE) array, and instruction controller. The resolution of the image in the chip is variable: high resolution for a focused area and low resolution for general view. It implements gray-scale and binary mathematical morphology algorithms in series to carry out low-level and mid-level image processing and sends out features of the image for various applications. It can perform image processing at over 1,000 frames/s (fps). A prototype chip with 64 × 64 pixels resolution and 6-bit gray-scale image is fabricated in 0.18 μm Standard CMOS process. The area size of chip is 1.5 mm × 3.5 mm. Each pixel size is 9.5 μm × 9.5 μm and each processing element size is 23 μm × 29 μm. The experiment results demonstrate that the chip can perform low-level and mid-level image processing and it can be applied in the real-time vision applications, such as high speed target tracking

Mesoscale Modeling of Spallation Failure in Fiber-Reinforced Concrete Slab due to Impact Loading

In this paper, a model for damage and fracture, considering the heterogeneity of material properties, is validated and used to investigate the mechanism of spallation in fiber-reinforced concrete (FRC) slabs with various fiber and aggregate contents under impact loading. Numerical simulations show that there is a marked difference in the failure patterns among slabs with various fiber and aggregate contents, and the fibers can remarkably improve the tensile strength of the concrete slab, effectively prevent the initiation and propagation of cracks, and inhibit the occurrence of spallation. Moreover, numerical simulations capture the whole process of the propagation of incident compressive stress waves in the FRC and the reflection of stress waves upon concrete surfaces and the spallation failure of FRC induced by the reflected tensile stress wave, which is obviously different from the failure pattern of FRC under static loads. The results of this study can also provide a valuable reference for studies on the tensile properties and failure modes of heterogeneous quasi-brittle materials and the design of FRC slabs with appropriate fiber contents

A high-speed CMOS image sensor for real-time vision chip

A high-speed CMOS image sensor for real-time vision chip is proposed. The high-speed CMOS image sensor consists of CMOS photodiode array, correlated double sampling(CDS) array, programmable gain amplifier(PGA) array, area-efficient single-slope analog-to-digital converter(ADC) array and controller circuit. It can perform the image capturing and row-parallel signal processing. It outputs digital signal or digital image at a frame rate of over1000 frame/s. It can reduce the fixed pattern noise(FPN) and amplify(or shrink) the output signals of the photodiode array to maintain the amplitude of the signal in row-parallel fashion. It can continuously perform8-bit ADC conversion in row-parallel. A128 pixel×128 pixel image sensor with128 rows of CDS, PGA and single-slope ADC is fabricated by using0.18μm1P6M CMOS process. The chip size is2.2 mm×2.6 mm. The measured results demonstrate that the designed chip can perform high-speed real-time optical signal capturing and processing. It can be applied to the real-time vision chip system

Effects of tracer position on screw placement technique in robot-assisted posterior spine surgery: a case–control study

Abstract Introduction Robot-assisted spine surgery is increasingly used in clinical work, and the installation of tracers as a key step in robotic surgery has rarely been studied. Objective To explore the potential effects of tracers on surgical outcomes in robot-assisted posterior spine surgery. Methods We reviewed all patients who underwent robotic-assisted posterior spine surgery at Beijing Shijitan Hospital over a 2-year period from September 2020 to September 2022. Patients were divided into two groups based on the location of the tracer (iliac spine or vertebral spinous process) during robotic surgery and a case–control study was conducted to determine the potential impact of tracer location on the surgical procedure. Data analysis was performed using SPSS.25 statistical software (SPSS Inc., Chicago, Illinois). Results A total of 525 pedicle screws placed in 92 robot-assisted surgeries were analyzed. The rate of perfect screw positioning was 94.9% in all patients who underwent robot-assisted spine surgery (498/525). After grouping studies based on the location of tracers, we found there was no significant difference in age, sex, height and body weight between the two groups. The screw accuracy (p < 0.01)was significantly higher in the spinous process group compared to the iliac group (97.5% versus 92.6%), but the operation time (p = 0.09) was longer in comparison. Conclusion Placing the tracer on the spinous process as opposed to the iliac spine may result in longer procedure duration or increased bleeding, but enhanced satisfaction of screw placement

Microstructural Origin of the Double Yield Points of the Metallocene Linear Low-Density Polyethylene (mLLDPE) Precursor Film under Uniaxial Tensile Deformation

The microstructural origin of the double yield points of metallocene linear low-density polyethylene (mLLDPE) precursor films has been studied with the assistance of the synchrotron radiation small- and wide-angle X-ray scattering (SAXS/WAXS). It has been shown that the microstructural origin of the double yield points is highly related to the initial orientation of the original precursor film. For less oriented mLLDPE precursor films, the rearrangement of lamellae and the appearance of the monoclinic phase are the microstructural origins of the first yield point. In comparison, for the highly-oriented mLLDPE precursor film, only the orthorhombic-monoclinic phase transition appears at the first yield point. The melting-recrystallization and the formation of the fibrillary structure happen beyond the second yield point for all studied mLLDPE precursor films. Finally, the detailed microstructural evolution roadmaps of mLLDPE precursor films under uniaxial tensile deformation have been established, which might serve as a guide for processing high-performance polymer films by post-stretching

Modified unilateral iliac screw fixation with partial reduction in the treatment of high-grade spondylolisthesis at L5/S1 in adult patients: introduction of key technique, report of clinical outcomes and analysis of spinopelvic parameters

Abstract Background Management of high-grade spondylolisthesis (HGS) remains challenging. Spinopelvic fixation such as iliac screw (IS) was developed to deal with HGS. However concerns regarding constructs prominence and increased infection-related revision surgery have complicated it’s use. We aim to introduce the modified iliac screw (IS) technique in treating high-grade L5/S1 spondylolisthesis and it’s clinical and radiological outcomes. Methods Patients with L5/S1 HGS who underwent modified IS fixation were enrolled. Pre- and postsurgical upright full spine radiographs were obtained to analyze sagittal imbalance, spinopelvic parameters, pelvic incidence-lumbar lordosis mismatch (PI-LL), slip percentage, slip angle (SA), and lumbosacral angle (LSA). Visual analogue scale (VAS), Oswestry disability index (ODI) were evaluated pre- and postoperatively for clinical outcomes assessment. Estimated blood loss, operating time, perioperative complications and revision surgery were documented. Results From Jan 2018 to March 2020, 32 patients (15 males) with mean age of 58.66 ± 7.77 years were included. The mean follow-up period was 49 months. The mean operation duration was 171.67 ± 36.66 min. At the last follow-up: (1) the VAS and ODI score were significantly improved (p < 0.05), (2) PI increased by an average of 4.3°, the slip percent, SA and LSA were significantly improved (p < 0.05), (3) four patients (16.7%) with global sagittal imbalance recovered a good sagittal alignment, PI-LL within ± 10° was observed in all patients. One patient experienced wound infection. One patient underwent a revision surgery due to pseudoarthrosis at L5/S1. Conclusion The modified IS technique is safe and effective in treating L5/S1 HGS. Sparing use of offset connector could reduce hardware prominence, leading to lower wound infection rate and less revision surgery. The long-term clinical affection of increased PI value is unknown

植物甾醇的抗炎性研究进展Progress on anti-inflammatory properties of phytosterols

植物甾醇作为一种食物来源中的功能性成分，对人体产生有益的影响。近年来，植物甾醇由于其安全性和有效的抗炎活性而受到广泛关注。为系统介绍植物甾醇的抗炎作用，综述了植物甾醇对多种炎症抑制作用的分子机制，包括对细胞因子和其他炎症相关因子、NF-KB信号通路及免疫系统的影响，介绍了植物甾醇对结肠炎、前列腺炎、肝炎及其他炎症的作用。植物甾醇是一种有效抗炎的活性物质，未来仍需系统研究其抗炎分子机制及进行临床研究。As a functional ingredient in food sources, phytosterols have a beneficial effect on the human body. In recent years, phytosterols have received widespread attention due to their safety and effective anti-inflammatory activity. In order to systematically summarize the function in anti-inflammation of phytosterols, the molecular mechanism of the inhibitory effects of phytosterols on various inflammations, including the effects on cytokines and other inflammation related factors, NF-KB signal pathway and immune system, and the effects of phytosterols on colitis, prostatitis, hepatitis and other inflammation were introduced. Phytosterol is an effective anti-inflammatory active substance. In the future, its anti-inflammatory molecular mechanism needs to be studied systematically and the clinical research needs to be carried out

A Novel CMOS Color Pixel for Vision Chips

This paper presents a novel CMOS color pixel with a 2D metal-grating structure for real-time vision chips. It consists of an N-well/P-substrate diode without salicide and 2D metal-grating layers on the diode. The periods of the 2D metal structure are controlled to realize color filtering. We implemented sixteen kinds of the pixels with the different metal-grating structures in a standard 0.18 mu m CMOS process. The measured results demonstrate that the N-well/P-substrate diode without salicide and with the 2D metal-grating structures can serve as the high speed RGB color active pixel sensor for real-time vision chips well

Catalytic Self-Limited Assembly at Hard Templates: A Mesoscale Approach to Graphene Nanoshells for Lithium–Sulfur Batteries

Hollow nanostructures afford intriguing structural features ranging from large surface area and fully exposed active sites to kinetically favorable mass transportation and tunable surface permeability. The unique properties and potential applications of graphene nanoshells with well-defined small cavities and delicately designed graphene shells are strongly considered. Herein, a mesoscale approach to fabricate graphene nanoshells with a single or few graphene layers and quite small diameters through a catalytic self-limited assembly of nanographene on <i>in situ</i> formed nanoparticles was proposed. The graphene nanoshells with a diameter of ca. 10–30 nm and a pore volume of 1.98 cm³ g^–1 were employed as hosts to accommodate the sulfur for high-rate lithium–sulfur batteries. A very high initial discharge capacity of 1520 mAh g^–1, corresponding to 91% sulfur utilization rate at 0.1 C, was achieved on a graphene nanoshell/sulfur composite with 62 wt % loading. A very high retention of 70% was maintained when the current density increased from 0.1 C to 2.0 C, and an ultraslow decay rate of 0.06% per cycle during 1000 cycles was detected