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Actual decision making problems are often based on the company decision maker's behavior factors, such as risk attitude, subjective preference, etc. Regret theory can well express the behavior of the decision maker. In this pursuit, a novel decision making method was developed, based on the regret theory for the multi-attribute decision making problem, in which attribute values were expressed by spherical fuzzy numbers. Distance measurement not only has extensive applications in fields such as pattern recognition and image processing, but also plays an important role in the research of fuzzy decision theory. The existing distance measures of spherical fuzzy set either have special cases of anti-intuition or are more complex in calculation, so finding suitable distance measures is also an important research topic in the decision-making theory of spherical fuzzy set. For this reason, we first establish a new distance of spherical fuzzy sets based on Hellinger distance of probability distribution. A decision maker's perception utility value function is proposed using the new distance formula, which is used to measure the regretful and rejoice value. Then we establish an optimization model for solving the attribute weights, when the information of attribute weight was partially known. Subsequently, the comprehensive perceived utility values were utilized to rank the order of the alternatives. Finally, a numerical example of assessment of logistics providers is used to show that the new decision making method is effective and feasible.
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Two novel chlorinated and nitrogenated azaphilones, namely N-butyl-2-aza-2-deoxychaetoviridin A (1) and N-hexyl-2-aza-2-deoxychaetoviridin A (2), along with a previously identified analogue, chaetoviridin A (3), were successfully obtained from Chaetomium globosum 2020HZ23, a marine algal-sourced endophytic fungus. The planar structures as well as the absolute configurations of these new metabolites were determined utilizing a synergistic approach that involved both spectroscopic techniques (1D/2D NMR and HRESIMS) and Density Functional Theory (DFT) calculations. Each compound was subject to in vitro cytotoxicity evaluation toward the A549 cancer cell line. Both compounds 1 and 2 demonstrated significant cytotoxicity, as evidenced by their respective IC50 values of 13.6 and 17.5 µM. Furthermore, 1 and 2 demonstrated potent cell migration inhibition, which elevated with increasing dose concentration. In contrast, compound 3 exhibited less cytotoxic activity relative to 1 and 2, suggesting that the cytotoxic potency escalates with N-substitution at the C-2 position and the introduction of a side chain. This finding could offer implications for future studies aimed at designing and refining lead compounds within this class.
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The aim of this paper is to develop a new decision making method considering decision makers' psychological behavior for multi-attribute decision making problem under intuitionistic trapezoidal fuzzy environment. We first put forward a new distance measure of intuitionistic trapezoidal fuzzy numbers. Then combining with cumulative prospect theory, we develop a novel decision making method, which can consider risk attitude of decision makers. Finally, an example is given to demonstrate the effectiveness and practicability of the proposed method.
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Tomada de Decisões , Lógica Fuzzy , AlgoritmosRESUMO
Magnetic resonance (MR) images are often contaminated by Gaussian noise, an electronic noise caused by the random thermal motion of electronic components, which reduces the quality and reliability of the images. This paper puts forward a hybrid denoising algorithm for MR images based on two sparsely represented morphological components and one residual part. To begin with, decompose a noisy MR image into the cartoon, texture, and residual parts by MCA, and then each part is denoised by using Wiener filter, wavelet hard threshold, and wavelet soft threshold, respectively. Finally, stack up all the denoised subimages to obtain the denoised MR image. The experimental results show that the proposed method has significantly better performance in terms of mean square error and peak signal-to-noise ratio than each method alone.
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Algoritmos , Imageamento por Ressonância Magnética/estatística & dados numéricos , Encéfalo/diagnóstico por imagem , Biologia Computacional , Simulação por Computador , Bases de Dados Factuais , Humanos , Interpretação de Imagem Assistida por Computador/estatística & dados numéricos , Neuroimagem/estatística & dados numéricos , Distribuição Normal , Análise de Componente Principal , Processamento de Sinais Assistido por Computador , Razão Sinal-Ruído , Análise de OndaletasRESUMO
OBJECTIVE: In vitro performance verification of ventricular assist devices using a mock circulatory loop is a prominent step to guarantee the system responses and the device performance and safety before the in vivo tests and ultimately clinical trials. METHODS: In this article, we performed a comprehensive literature research to establish a verification matrix consisting of 12 test cases, defined by a set of physiological parameters which are commonly used to characterize a physiological condition. The clinical hemodynamic indicators for defining successful mechanical support were used as the acceptance criteria. A mock circulatory loop was customized to simulate the test cases, and a full verification protocol was described in details. An example left ventricular assist device was incorporated in the loop to accomplish a standard ventricular assist device performance verification. RESULT: The test cases based on clinical data with sufficient safety margin represent our understanding in defining the extremes of operation. The mock circulatory loop was capable of generating the test conditions in the verification matrix and reproducing the Frank-Starling law of the native heart. The effect of the left ventricular assist device assistance (characterized by the total systemic flow, mean aortic pressure, and left atrial pressure) was well verified by the proposed protocol and acceptance criteria. CONCLUSION: To date, all left ventricular assist devices made in China have been evaluated according this protocol and some of them have entered the clinical trial stage. We are closely observing the clinical data in order to further improve the performance of the platform and encourage more advances in mechanical circulatory assist devices.
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Sistema Cardiovascular/fisiopatologia , Coração Auxiliar , Pressão Arterial , China , Hemodinâmica , Humanos , Modelos CardiovascularesRESUMO
Artificial intelligence is a blooming branch of medical device. Its development and quality control all rely on high quality clinical data. Since there is no established standard or guidance yet, it is important to study how to build and utilize a dataset appropriately and scientifically, especially for the decrease of clinical trial expense. With reference to the current status of premarket review and related guidance in developed countries, this paper analyzes the role and requirement of datasets in the quality control of AI medical device, providing useful information for regulation agencies and the development of public datasets for AI.
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Inteligência Artificial , Equipamentos e Provisões , Análise de Dados , Controle de QualidadeRESUMO
Iridium-rhodium is generally applied as a thermocouple material, with max operating temperature about 2150⯰C. In this study, a ultrasonic temperature measurement system was designed by using Iridium-rhodium (60%Ir-40%Rh) alloy as an acoustic waveguide sensor material, and the system was preliminarily tested in a high-temperature oxidation environment. The result of ultrasonic temperature measurement shows that this system can indeed work stably in high-temperature oxidation environments. The relationship between temperature and delay time of ultrasonic thermometry up to 2200⯰C was illustrated. Iridium-rhodium materials were also investigated in order to fully elucidate the proposed waveguide sensor's performance in a high-temperature oxidation environment. This system lays a foundation for further application of high-temperature measurement.
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This paper analyses overall situation of the national quality inspection for medical devices in recent 13 years. The statistics cover the inspected varieties, sampling quantity and quality status. The achievements and suggestions are provided, which are helpful for future work.
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Equipamentos e Provisões/normas , HumanosRESUMO
OBJECTIVE: Establish the test platform of the intraocular lens loop, and the platform was evaluated through the experiment. METHODS: The intraocular lens loop test platform is made up with three models. The different intraocular lens haptics support force can be completed by replacing different sample holder model. RESULTS: The standard deviation and the coefficient of variation were calculated through the result of the fifteen samples. The standard deviation was 0.04 mN, and the coefficient of variation was 0.66%. The two values were in the acceptable range. CONCLUSIONS: The platform was so stabilizing that it could be used to test support force of IOL loop. The different shapes of IOL could be tested on the platform through the replacement of the holder model.
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Lentes Intraoculares , Desenho de PróteseRESUMO
This paper introduces the implement method of DICOM medical image compression technology, The image part of DICOM files are extracted and converted to BMP format. The non-image information in DICOM file are stored into the text. When the final image of JPEG standard and non-image information are encapsulated to DICOM format images, it realizes the compression of medical image, which is beneficial to the image storage and transmission.
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Compressão de Dados/métodos , Processamento de Imagem Assistida por Computador/métodos , SoftwareRESUMO
How to use clustering techniques in PACS system is introduced. Two kinds of cluster solution to configure PACS system is proposed.
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Sistemas Computacionais , Sistemas de Informação em Radiologia/organização & administraçãoRESUMO
The regulatory history and status of in vitro diagnostic reagents (IVD) at home and abroad are introduced. Suggestions are also provided on the administration of IVD.
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Técnicas e Procedimentos Diagnósticos/instrumentação , Administração de Serviços de Saúde , Indicadores e Reagentes/normas , Vigilância de Produtos ComercializadosRESUMO
Structures were obtained from images with morphological characteristics to register with voxel-based method. We applied simple morphological operations to obtain human brain cortex and chose normalized mutual information as similarity measure for the geometric alignment of PET and MR images. Evaluation used nine patients, and the results showed that sub-voxel accuracy was achieved and the registration process was significantly more rapid. Thus this new automated multi-modality registration method is more robust and has high accuracy.
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Algoritmos , Córtex Cerebral/anatomia & histologia , Córtex Cerebral/diagnóstico por imagem , Interpretação de Imagem Assistida por Computador/métodos , Imageamento Tridimensional/métodos , Imageamento por Ressonância Magnética/métodos , Técnica de Subtração , Tomografia Computadorizada de Emissão/métodos , Humanos , Aumento da Imagem/métodos , Reprodutibilidade dos Testes , Sensibilidade e EspecificidadeRESUMO
We propose radial harmonic Fourier moments, which are shifting, scaling, rotation, and intensity invariant. Compared with Chebyshev-Fourier moments, the new moments have superior performance near the origin and better ability to describe small images in terms of image-reconstruction errors and noise sensitivity. A multidistortion-invariant pattern-recognition experiment was performed with radial harmonic Fourier moments.
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Maximization of mutual information is a powerful criterion for 3D medical image registration, allowing robust and fully accurate automated rigid registration of multi-modal images in a various applications. In this paper, a method based on normalized mutual information for 3D image registration was presented on the images of CT, MR and PET. Powell's direction set method and Brent's one-dimensional optimization algorithm were used as optimization strategy. A multi-resolution approach is applied to speedup the matching process. For PET images, pre-procession of segmentation was performed to reduce the background artefacts. According to the evaluation by the Vanderbilt University, Sub-voxel accuracy in multi-modality registration had been achieved with this algorithm.