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1.
J Synchrotron Radiat ; 31(Pt 2): 385-393, 2024 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-38300130

RESUMEN

As a representative of the fourth-generation light sources, the High Energy Photon Source (HEPS) in Beijing, China, utilizes a multi-bend achromat lattice to obtain an approximately 100 times emittance reduction compared with third-generation light sources. New technologies bring new challenges to operate the storage ring. In order to meet the beam commissioning requirements of HEPS, a new framework for the development of high-level applications (HLAs) has been created. The key part of the new framework is a dual-layer physical module to facilitate the seamless fusion of physical simulation models with the real machine, allowing for fast switching between different simulation models to accommodate the various simulation scenarios. As a framework designed for development of physical applications, all variables are based on physical quantities. This allows physicists to analytically assess measurement parameters and optimize machine parameters in a more intuitive manner. To enhance both extensibility and adaptability, a modular design strategy is utilized, partitioning the entire framework into discrete modules in alignment with the requirements of HLA development. This strategy not only facilitates the independent development of each module but also minimizes inter-module coupling, thereby simplifying the maintenance and expansion of the entire framework. To simplify the development complexity, the design of the new framework is implemented using Python and is called Python-based Accelerator Physics Application Set (Pyapas). Taking advantage of Python's flexibility and robust library support, we are able to develop and iterate quickly, while also allowing for seamless integration with other scientific computing applications. HLAs for both the HEPS linac and booster have been successfully developed. During the beam commissioning process at the linac, Pyapas's ease of use and reliability have significantly reduced the time required for the beam commissioning operators. As a development framework for HLA designed for the new-generation light sources, Pyapas has the versatility to be employed with HEPS, as well as with other comparable light sources, due to its adaptability.

2.
BMC Surg ; 23(1): 51, 2023 Mar 09.
Artículo en Inglés | MEDLINE | ID: mdl-36894932

RESUMEN

BACKGROUND: Minimally invasive vascular intervention (MIVI) is a powerful technique for the treatment of cardiovascular diseases, such as abdominal aortic aneurysm (AAA), thoracic aortic aneurysm (TAA) and aortic dissection (AD). Navigation of traditional MIVI surgery mainly relies only on 2D digital subtraction angiography (DSA) images, which is hard to observe the 3D morphology of blood vessels and position the interventional instruments. The multi-mode information fusion navigation system (MIFNS) proposed in this paper combines preoperative CT images and intraoperative DSA images together to increase the visualization information during operations. RESULTS: The main functions of MIFNS were evaluated by real clinical data and a vascular model. The registration accuracy of preoperative CTA images and intraoperative DSA images were less than 1 mm. The positioning accuracy of surgical instruments was quantitatively assessed using a vascular model and was also less than 1 mm. Real clinical data used to assess the navigation results of MIFNS on AAA, TAA and AD. CONCLUSIONS: A comprehensive and effective navigation system was developed to facilitate the operation of surgeon during MIVI. The registration accuracy and positioning accuracy of the proposed navigation system were both less than 1 mm, which met the accuracy requirements of robot assisted MIVI.


Asunto(s)
Procedimientos Quirúrgicos Robotizados , Robótica , Cirugía Asistida por Computador , Humanos , Procedimientos Quirúrgicos Mínimamente Invasivos/métodos , Cirugía Asistida por Computador/métodos , Angiografía de Substracción Digital , Imagenología Tridimensional/métodos
3.
J Synchrotron Radiat ; 25(Pt 6): 1611-1618, 2018 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-30407168

RESUMEN

The High Energy Photon Source (HEPS), a 6 GeV green-field diffraction-limited storage ring light source, will be built in Beijing, China. The HEPS design has been evolving for about ten years, and is now mostly finished and ready for construction. The storage ring is based on a modified hybrid seven-bend achromat (7BA) design, where bending magnets with reverse bending angles and longitudinal gradients are adopted to reach an ultralow natural emittance of 34.2 pm with a circumference of 1360.4 m. The central slice of the dipole in the middle of the modified hybrid 7BA, with flexible magnetic field, is used as the source of the bending-magnet beamline. Moreover, alternating high- and low-beta sections are specially designed to generate and deliver X-ray synchrotron radiation with high brightness of 5 × 1022 photons s-1 mm-2 mrad-2 (0.1% bandwidth)-1. Here, the HEPS storage ring design and solutions to the challenges inherent in this ultralow-emittance design are presented.

4.
Appl Microbiol Biotechnol ; 102(11): 4785-4797, 2018 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-29610966

RESUMEN

Avibacterium paragallinarum is a Gram-negative bacterium that causes infectious coryza in chicken. It was reported that the capsule polysaccharides extracted from Av. paragallinarum genotype A contained chondroitin. Chondroitin synthase of Av. paragallinarum (ApCS) encoded by one gene within the presumed capsule biosynthesis gene cluster exhibited considerable homology to identified bacterial chondroitin synthases. Herein, we report the identification and characterization of ApCS. This enzyme indeed displays chondroitin synthase activity involved in the biosynthesis of the capsule. ApCS is a bifunctional protein catalyzing the elongation of the chondroitin chain by alternatively transferring the glucuronic acid (GlcA) and N-acetyl-D-galactosamine (GalNAc) residues from their nucleotide forms to the non-reducing ends of the saccharide chains. GlcA with a para-nitrophenyl group (pNP) could serve as the acceptor for ApCS; this enzyme shows a stringent donor tolerance when the acceptor is as small as this monosaccharide. Then, UDP-GalNAc and GlcA-pNP were injected sequentially through the chip-immobilized chondroitin synthases, and the surface plasmon resonance data demonstrated that the up-regulated extent caused by the binding of the donor is one possibly essential factor in successful polymerization reaction. This conclusion will, therefore, enhance the understanding of the mode of action of glycosyltransferase. Surprisingly, high activity at near-zero temperature as well as weak temperature dependence of this novel bacterial chondroitin synthase indicate that ApCS was a cold-active enzyme. From all accounts, ApCS becomes the fourth known bacterial chondroitin synthase, and the potential applications in artificial chondroitin sulfate and glycosaminoglycan synthetic approaches make it an attractive glycosyltransferase for further investigation.


Asunto(s)
Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Gammaproteobacteria/enzimología , Gammaproteobacteria/genética , N-Acetilgalactosaminiltransferasas/genética , N-Acetilgalactosaminiltransferasas/metabolismo , Especificidad por Sustrato
5.
Sensors (Basel) ; 18(3)2018 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-29494524

RESUMEN

In this paper, a novel algorithm based on convolutional neural network (CNN) is proposed to detect foreign object debris (FOD) based on optical imaging sensors. It contains two modules, the improved region proposal network (RPN) and spatial transformer network (STN) based CNN classifier. In the improved RPN, some extra select rules are designed and deployed to generate high quality candidates with fewer numbers. Moreover, the efficiency of CNN detector is significantly improved by introducing STN layer. Compared to faster R-CNN and single shot multiBox detector (SSD), the proposed algorithm achieves better result for FOD detection on airfield pavement in the experiment.

6.
Transl Stroke Res ; 2024 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-38558011

RESUMEN

Intracerebral hemorrhage (ICH) is the most serious form of stroke and has limited available therapeutic options. As knowledge on ICH rapidly develops, cutting-edge techniques in the fields of surgical robots, regenerative medicine, and neurorehabilitation may revolutionize ICH treatment. However, these new advances still must be translated into clinical practice. In this review, we examined several emerging therapeutic strategies and their major challenges in managing ICH, with a particular focus on innovative therapies involving robot-assisted minimally invasive surgery, stem cell transplantation, in situ neuronal reprogramming, and brain-computer interfaces. Despite the limited expansion of the drug armamentarium for ICH over the past few decades, the judicious selection of more efficacious therapeutic modalities and the exploration of multimodal combination therapies represent opportunities to improve patient prognoses after ICH.

7.
Ann Biomed Eng ; 51(9): 1933-1941, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37405558

RESUMEN

Intracerebral hemorrhage (ICH) is a stroke subtype with high mortality and disability, and there are no proven medical treatments that can improve the functional outcome of ICH patients. Robot-assisted neurosurgery is a significant advancement in the development of minimally invasive surgery for ICH. This review encompasses the latest advances and future directions of surgical robots for ICH. First, three robotic systems for neurosurgery applied to ICH are illustrated. Second, the key technologies of robot-assisted surgery for ICH are introduced in aspects of stereotactic technique and navigation, the puncture instrument, and hematoma evacuation. Finally, the limitations of current surgical robots are summarized, and the possible development direction is discussed, which is named "multisensor fusion and intelligent aspiration control of minimally invasive surgical robot for ICH". It is expected that the new generation of surgical robots for ICH will facilitate quantitative, precise, individualized, standardized treatment strategies for ICH.


Asunto(s)
Robótica , Humanos , Resultado del Tratamiento , Hemorragia Cerebral/cirugía , Procedimientos Quirúrgicos Mínimamente Invasivos , Procedimientos Neuroquirúrgicos/métodos
8.
Transl Stroke Res ; 2023 Dec 29.
Artículo en Inglés | MEDLINE | ID: mdl-38157144

RESUMEN

Intracerebral hemorrhage (ICH) is the second major stroke type, with high incidence, high disability rate, and high mortality. At present, there is no effective and reliable treatment for ICH. As a result, most patients have a poor prognosis. Minimally invasive surgery (MIS) is the fastest treatment method to remove hematoma, which is characterized by less trauma and easy operation. Some studies have confirmed the safety of MIS, but there are still no reports showing that it can significantly improve the functional outcome of ICH patients. Intracranial pressure (ICP) monitoring is considered to be an important part of successful treatment in traumatic brain diseases. By monitoring ICP in real time, keeping stable ICP could help patients with craniocerebral injury get a good prognosis. In the course of MIS treatment of ICH patients, keeping ICP stable may also promote patient recovery. In this review, we will take ICP monitoring as the starting point for an in-depth discussion.

9.
Biomed Phys Eng Express ; 8(4)2022 05 06.
Artículo en Inglés | MEDLINE | ID: mdl-35439744

RESUMEN

In intervention surgery, DSA images provide a new way to observe the vessels and catheters inside the patient. Extracting coronary artery from the dynamic complex background fast improves the effectiveness directly in clinical interventional surgery. This article proposes an incremental robust principal component analysis (IRPCA) method to extract contrast-filled vessels from x-ray coronary angiograms. RPCA is a matrix decomposition method that decomposes a video matrix into foreground and background, commonly used to model complex backgrounds and extract target objects. IRPCA pre-optimizes an x-ray image sequence. When a new x-ray sequence is received, IRPCA optimizes it based on the pre-optimized matrix according to the strategy of minimizing the energy function to obtain the foreground matrix of the new sequence. Besides, based on the idea that the new x-ray sequence introduces new information to the pre-optimized matrix, we propose UIRPCA to improve the performence of IRPCA. Compared with the traditional RPCA method, IRPCA and UIRPCA save much time while ensuring that other indicators remain basically unchanged. The experiment results based on real data show the superiority of the proposed method over other RPCA algorithms.


Asunto(s)
Algoritmos , Vasos Coronarios , Angiografía Coronaria/métodos , Vasos Coronarios/diagnóstico por imagen , Humanos , Análisis de Componente Principal , Rayos X
10.
IEEE J Biomed Health Inform ; 25(9): 3300-3309, 2021 09.
Artículo en Inglés | MEDLINE | ID: mdl-33347417

RESUMEN

Cardiovascular image registration is an essential approach to combine the advantages of preoperative 3D computed tomography angiograph (CTA) images and intraoperative 2D X-ray/digital subtraction angiography (DSA) images together in minimally invasive vascular interventional surgery (MIVI). Recent studies have shown that convolutional neural network (CNN) regression model can be used to register these two modality vascular images with fast speed and satisfactory accuracy. However, CNN regression model trained by tens of thousands of images of one patient is often unable to be applied to another patient due to the large difference and deformation of vascular structure in different patients. To overcome this challenge, we evaluate the ability of transfer learning (TL) for the registration of 2D/3D deformable cardiovascular images. Frozen weights in the convolutional layers were optimized to find the best common feature extractors for TL. After TL, the training data set size was reduced to 200 for a randomly selected patient to get accurate registration results. We compared the effectiveness of our proposed nonrigid registration model after TL with not only that without TL but also some traditional intensity-based methods to evaluate that our nonrigid model after TL performs better on deformable cardiovascular image registration.


Asunto(s)
Imagenología Tridimensional , Tomografía Computarizada por Rayos X , Angiografía , Humanos , Aprendizaje Automático , Redes Neurales de la Computación
11.
J Ethnopharmacol ; 267: 113476, 2021 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-33075438

RESUMEN

ETHNOPHARMACOLOGICAL RELEVANCE: Toxicodendron vernicifluum (Stokes) F.A. Barkley (syn. Rhus verniciflua or vernicifera Stokes, Anacardiaceae) (RVS), the lacquer tree, also known as sumac, has been used in China, Japan and South Korea for thousands of years as a highly durable coating material and a traditional herbal medicine, which contains medicinal ingredients with anti-tumor, anti-inflammatory, antiviral, and anti-rheumatic activities. AIM OF THIS REVIEW: This review intends to provide a comprehensive and critical appraisal of RVS, including its phytochemical data, botanical and pharmacological literature that support its therapeutic potential in treatment on human diseases, with emphasis on the isolation of natural occurring compounds and detailed pharmacological investigations. MATERIALS AND METHODS: Specific information of RVS was collected by using the key words "Toxicodendron vernicifluum", "Rhus verniciflua Stokes", "Rhus vernicifera Stokes" and "Lacquer tree" through published scientific materials (including PubMed, ScienceDirect, Wiley, ACS, CNKI, Scifinder, Springer, Web of Science, Google Scholar, and Baidu Scholar) and other literature sources. RESULTS: The major phytoconstituents, 175 of which are presented in this review, including flavonoids, urushiols, terpenes, phenolic acids and other types of compounds, of which flavonoids and urushiols are main components. The extracts and isolates purified from RVS showed a wide range of in vitro and in vivo pharmacological effects, such as anti-cancer, anti-oxidation, anti-inflammatory, antimicrobial, tyrosinase inhibition and so on. CONCLUSION: The modern pharmacological research of RVS mainly focus on the pharmacological effects of crude extract or active constituents, of which the flavonoids are widely studied. However, there are few reports on the relationship between pharmacological effects and their structures. And at present, there is still a lack of researches that are of both effective and in-depth. Meanwhile, there is little research on quality control. Apart from the wood and lacquer, other botanical parts also need to be explored further. In addition to phenolic compounds, the study on other types of components in T. vernicifluum would start more sparks for the discovery of new bioactive principles.


Asunto(s)
Medicina Tradicional de Asia Oriental , Fitoquímicos/farmacología , Extractos Vegetales/farmacología , Toxicodendron , Animales , Humanos , Fitoquímicos/aislamiento & purificación , Fitoterapia , Extractos Vegetales/aislamiento & purificación , Toxicodendron/química
12.
Acta Crystallogr Sect E Struct Rep Online ; 66(Pt 4): o740, 2010 Mar 03.
Artículo en Inglés | MEDLINE | ID: mdl-21580585

RESUMEN

In the title zwitterionic compound, C(16)H(8)N(4)O(4), the dihedral angle between the carboxyl and carboxyl-ate groups is 72.14 (2)°. In the crystal, mol-ecules are linked by strong inter-molecular O-H⋯O(-) and N(+)-H⋯O(-) hydrogen bonds into double chains extended along [001]. These chains are additionally stabilized by π-π stacking inter-actions between the pyridine and benzene rings [centroid-centroid distance = 3.5542 (8) Å].

13.
Artículo en Inglés | MEDLINE | ID: mdl-32011251

RESUMEN

Fast and accurate ellipse detection is critical in certain computer vision tasks. In this paper, we propose an arc adjacency matrix-based ellipse detection (AAMED) method to fulfill this requirement. At first, after segmenting the edges into elliptic arcs, the digraph-based arc adjacency matrix (AAM) is constructed to describe their triple sequential adjacency states. Curvature and region constraints are employed to make the AAM sparse. Secondly, through bidirectionally searching the AAM, we can get all arc combinations which are probably true ellipse candidates. The cumulative-factor (CF) based cumulative matrices (CM) are worked out simultaneously. CF is irrelative to the image context and can be pre-calculated. CM is related to the arcs or arc combinations and can be calculated by the addition or subtraction of CF. Then the ellipses are efficiently fitted from these candidates through twice eigendecomposition of CM using Jacobi method. Finally, a comprehensive validation score is proposed to eliminate false ellipses effectively. The score is mainly influenced by the constraints about adaptive shape, tangent similarity, distribution compensation. Experiments show that our method outperforms the 12 state-of-the-art methods on 9 datasets as a whole, with reference to recall, precision, F-measure, and time-consumption.

14.
Acta Crystallogr Sect E Struct Rep Online ; 65(Pt 12): m1604-5, 2009 Nov 18.
Artículo en Inglés | MEDLINE | ID: mdl-21578631

RESUMEN

In the crystal structure of the title compound, [Zn(C(7)H(4)O(4)S)(C(10)H(8)N(2))(H(2)O)]·2H(2)O, the Zn(II) ion assumes a trigonal-bipyramidal coordination geometry completed by two N atoms from a 2,2'-bipyridine ligand, two O atoms from a 2-(3-thien-yl)malonate anion and a water mol-ecule. The S atom of the 2-(3-thien-yl)malonate ligand is disordered over two sites with an occupancy ratio of 0.701 (5):0.299 (5). Inter-molecular O-H⋯O hydrogen bonding is present in the crystal structure.

15.
Comput Biol Med ; 63: 277-86, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-25458811

RESUMEN

A shortest path-based algorithm is proposed in this paper to find splitting lines for touching cell nuclei. First, an initial splitting line is obtained through the distance transform of a marker image and the watershed algorithm. The initial splitting line is then separated into different line segments as necessary, and the endpoint positions of these line segments are adjusted to the concave points on the contour. Finally, a shortest path algorithm is used to find the accurate splitting line between the starting-point and the end-point, and the final split can be achieved by the contour of the touching cell nuclei and the splitting lines. Comparisons of experimental results show that the proposed algorithm is effective for segmentation of different types of touching cell nuclei.


Asunto(s)
Algoritmos , Núcleo Celular , Procesamiento de Imagen Asistido por Computador
16.
Comput Biol Med ; 52: 49-56, 2014 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-25014497

RESUMEN

Image distortion correction and geometric calibration are critical operations for using C-arm DSA (Digital Subtraction Angiography) images to digitally navigate vascular interventional surgery. In traditional ways, C-arm images are corrected with global or local correction methods where a supposed virtual ideal image is needed, and then the corrected images are utilized to calibrate the C-arm with a pin-hole model. In this paper, we propose a new method to calibrate the C-arm with a nonlinear model and to improve navigation performance. We first calibrate the C-arm with a nonlinear model and then the distortion correction is accomplished without virtual ideal image. In this paper, the nonlinear model of C-arm imaging system is addressed at first, and then the C-arm is calibrated with a two-stage method. In the first stage, the C-arm is calibrated with the markers in image center by RAC (radial alignment constraint) method, and in the second stage the calibration parameters are optimized with Levenberg-Marquadt algorithm by minimizing the sum of the square of difference between all markers׳ real distorted positions and their theoretical distorted positions in the phantom image. Based on the calibration result, the image distortion can be corrected. To verify our method, experiments were conducted with a conventional DSA C-arm machine in hospital. The errors in distortion correction and 3D (three-dimensional) reconstruction were quantitatively compared with the global polynomial correction method and visual model method, and the results showed that the proposed method had better performance in distortion correction and 3D reconstruction.


Asunto(s)
Angiografía de Substracción Digital , Automatización , Calibración , Humanos
17.
Int J Med Robot ; 9(2): 230-9, 2013 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-23520192

RESUMEN

BACKGROUND: Robot-assisted vascular interventional surgery (VIS) enables the surgeon to teleoperate a catheter in a safe cabinet, such that exposure to X-ray radiation is reduced. For safe and accurate teleoperation, system structure and image guidance is important. METHODS: The system structure of the developed remote-controlled vascular interventional robot (RVIR) and its image guidance system (IGS) are introduced. RVIR is based on a master-slave structure. Key technologies of IGS are addressed, including C-arm calibration, distortion correction, catheter localization and 3D vasculature reconstruction. RESULTS: Experiments show that the RMS error of distortion correction is 0.35 pixels, and 0.53 mm for distance reconstruction. The error in catheter localization between the IGS and the encoders is small. In vitro and in vivo tests verified the feasibility of RVIR. CONCLUSIONS: Experiments indicate that the RVIR is feasible and valid to help the surgeon perform VIS remotely; the function and reconstruction accuracy of IGS can satisfy the surgeon's requirement to guide the RVIR.


Asunto(s)
Imagenología Tridimensional/instrumentación , Sistemas Hombre-Máquina , Robótica/instrumentación , Cirugía Asistida por Computador/instrumentación , Telemedicina/instrumentación , Tomografía Computarizada por Rayos X/instrumentación , Procedimientos Quirúrgicos Vasculares/instrumentación , Diseño de Equipo , Análisis de Falla de Equipo
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