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1.
Sensors (Basel) ; 24(13)2024 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-39001131

RESUMO

Due to the uniqueness of the underwater environment, traditional data aggregation schemes face many challenges. Most existing data aggregation solutions do not fully consider node trustworthiness, which may result in the inclusion of falsified data sent by malicious nodes during the aggregation process, thereby affecting the accuracy of the aggregated results. Additionally, because of the dynamically changing nature of the underwater environment, current solutions often lack sufficient flexibility to handle situations such as node movement and network topology changes, significantly impacting the stability and reliability of data transmission. To address the aforementioned issues, this paper proposes a secure data aggregation algorithm based on a trust mechanism. By dynamically adjusting the number and size of node slices based on node trust values and transmission distances, the proposed algorithm effectively reduces network communication overhead and improves the accuracy of data aggregation. Due to the variability in the number of node slices, even if attackers intercept some slices, it is difficult for them to reconstruct the complete data, thereby ensuring data security.

2.
Sensors (Basel) ; 24(9)2024 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-38732984

RESUMO

Underwater acoustic sensor networks have a wide range of applications in both civil and military fields, but the complex and changing underwater environment makes them vulnerable to multiple security threats. Trust mechanisms are effective ways to enhance network security and reliability. In order to improve the accuracy of trust evaluation and the detection rate of abnormal nodes, this paper proposes an adaptive trust evaluation model based on fuzzy logic. This model adopts a variable weight fuzzy comprehensive evaluation algorithm to dynamically adjust the weights of three direct trust indicators to ensure the accuracy of direct trust evaluation. Then, it uses fuzzy closeness to eliminate unreliable recommendation trust and adjusts the weight of recommendation trust through deviation to improve the accuracy of indirect trust. The simulation results show that the model can effectively improve the accuracy of trust evaluation and the detection rate of abnormal nodes. Especially when the link quality is unstable, the success rate of detecting abnormal nodes in this model is improved by more than 10% compared with the existing trust model.

3.
Heliyon ; 10(7): e28548, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38571649

RESUMO

Purpose: The hand motor cortex (HMC) is a reliable anatomical landmark for identifying the precentral gyrus. The current study aimed to investigate the morphology of HMC on axial MRI of glioma patients, propose a new morphological classification of HMC and analyze the effect of tumors on the morphology of HMC. Methods: A retrospective study of 276 adult right-handed glioma patients was conducted. The morphology of HMC was assessed using T2 axial images. Subsequently, the distribution of morphological subtypes was compared between the bilateral hemispheres and the tumor-affected and healthy hemispheres. Finally, the influence of tumor pathology on the morphology of HMC was investigated. Results: A new morphological classification of HMC with four subtypes (Ω, ε, Ω-ε and ε-Ω) was proposed. No significant difference was identified in the distribution of morphological subtypes between the bilateral hemispheres (p = 0.0901, Chi-square test), or between the tumor-affected and healthy hemispheres (p = 0.3507, Chi-square test), and the morphology of HMC between the bilateral hemispheres were consistent (p < 0.0001, Kappa test). In addition, a significant difference was identified in the distribution of morphological subtypes between astrocytic and oligodendroglial tumors (p = 0.0135, Chi-square test). Conclusion: In the current study, we proposed a new morphological classification of HMC, and found that tumor could affect the morphology of HMC in glioma patients. The results can help our clinical practice, enabling us to further understand the spatial structure of the cerebral hemispheres.

4.
Heliyon ; 10(7): e28550, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38590907

RESUMO

Background: The complexity of calculating the Hijdra score has limited its clinical utility in aiding the diagnosis of intracranial ruptured aneurysms. Objective: This study aimed to investigate the diagnostic and prognostic value of the modified Hijdra score in patients with aneurysmal subarachnoid hemorrhage (aSAH). Methods: Data from 773 patients with subarachnoid hemorrhage (SAH) at the First People's Hospital of Lianyungang from January 2018 to June 2023 were collected. The modified Hijdra scoring method simplifies the assessment of 10 basal cisterns/cisterns fissures compared to the traditional scoring method, with scores ranging from 0 to 2 for each item, and assigns specific scores to hematomas larger than 1 cm in diameter. The data were divided into an evaluation group (n = 641) and a validation group (n = 132). In the evaluation group, the performance of the modified Hijdra score in diagnosis and prognostic prediction was assessed, while the diagnostic and prognostic prediction efficacy of the modified Hijdra method was evaluated using the validation set. Results: Among the 641 patients in the evaluation group,550 (85. 8%) were diagnosed with intracranial aneurysms. The modified Hijdra score demonstrated an AUC of 0. 894 for aneurysm diagnosis, with a sensitivity of 98. 0% and a specificity of 64. 8% at a CutOff value of 7. 5. The diagnostic efficacy of the modified Hijdra score was 93. 24%, with a negative predictive value of 84. 29%, while the Hijdra score 's diagnostic efficacy was 85. 34% with a negative predictive value of 48. 89%. The AUC of the modified Hijdra score for predicting prognosis in patients with aneurysms was 0. 824, with a sensitivity of 84. 3% and a specificity of 70. 0% at a CutOff value of 16. 5. In CTA-negative patients, the modified Hijdra score was significantly higher (P < 0. 0001) in patients with aneurysmal SAH (15. 48 ± 3. 93) compared to those with non-aneurysmal SAH (6. 31 ± 4. 52). Conclusions: The modified Hijdra score is a valuable tool for assisting in the diagnosis and prognosis prediction of aneurysmal subarachnoid hemorrhage.

5.
ACS Appl Mater Interfaces ; 15(3): 4774-4780, 2023 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-36625686

RESUMO

Nanotribology using atomic force microscopy (AFM) can be considered as a unique approach to analyze phase transition materials by localized mechanical interaction. In this work, we investigate friction on the lamellar transition metal dichalcogenide 1T-TaS2, which can undergo first-order charge density wave (CDW) phase transitions. Based on temperature-dependent atomic force microscopy under ultrahigh vacuum conditions (UHV), we can characterize the general friction levels across the first-order phase transitions and for the different phases. While structural and electronic properties for different phases appear to be of minor influence on friction, a distinct peak in friction is observed during the phase transition when cooling the sample from the nearly commensurate CDW (NC-CDW) phase to the commensurate CDW (C-CDW) phase. By performing systematic measurements as a function of load, scan velocity, and scan time, a recently proposed friction mechanism can be corroborated, where the AFM tip gradually induces local transformations of the material close to the spinodal point in a thermally activated and shear-assisted process until the surface is fully "harvested". Our results demonstrate that repeated nanomechanical stress can trigger local first-order phase transitions constituting a so far little explored mechanical energy dissipation channel.

6.
Sci Rep ; 12(1): 16851, 2022 10 07.
Artigo em Inglês | MEDLINE | ID: mdl-36207375

RESUMO

In this paper, a special ultrasonic microforming method, Micro Ultrasonic thin Sheetmetal Forming using molten plastic as a flexible punch (short as Micro-USF), was used to conduct micro-punching experiments on stainless steel sheet with thickness of 10 µm and 20 µm. The influence of ultrasonic vibration on forming force and forming quality were investigated. The experimental results showed that the forming force required for punching thin sheet metal decreased gradually as the ultrasonic time or ultrasonic power increased. By applying the ultrasonic vibration effect, the forming force could be decreased dramatically and the maximum value of forming force drop could reach 86%. Moreover, with the application of ultrasonic vibration, the size accuracy and shape accuracy of micro-holes could be increased by 36.92% and 22.65%, but the cross-section quality of micro-holes were not significantly improved.


Assuntos
Aço Inoxidável , Vibração , Fenômenos Mecânicos , Plásticos , Ondas Ultrassônicas
7.
Contrast Media Mol Imaging ; 2022: 4938587, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35795879

RESUMO

The aim of this study was to explore the application value of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) based on a convolutional neural network (CNN) algorithm in glioma diagnosis and tumor segmentation. 66 patients with gliomas who were diagnosed and treated in the hospital were selected as the research objects. The patients were rolled into the high-grade glioma group (HGG, 46 cases) and the low-grade glioma group (LGG, 20 cases) according to the World Health Organization glioma grading standard. All patients received a conventional plain scan and a DCE-MRI. Parameters such as volume transfer constant (K trans), rate constant (K ep ), extracellular volume (V e ), and mean plasma volume (V p ) were calculated, and the parameters of patients of each grade were analyzed. The efficacy of each parameter in diagnosing glioma was analyzed through a receiver operating characteristic curve. All images were segmented by the CNN algorithm. The CNN algorithm showed good performance in DCE-MRI image segmentation. The mean, standard deviation, kurtosis, and skewness of K trans and V e , the standard deviation and skewness of K ep , and the mean and standard deviation of V p were statistically considerable in differentiating HGG and LGG (P < 0.05). ROC analysis showed that the standard deviation of K trans (0.885) had the highest diagnostic accuracy in distinguishing HGG and LGG. The values of K trans, V e , and V p were positively correlated with Ki-67 (r = 0.346, P = 0.014; r = 0.335, P = 0.017; r = 0.323, P = 0.022). In summary, the CNN-based DCE-MRI technology had high application value in glioma diagnosis and tumor segmentation.


Assuntos
Glioma , Imageamento por Ressonância Magnética , Algoritmos , Encéfalo , Glioma/diagnóstico por imagem , Humanos , Redes Neurais de Computação
8.
J Transl Med ; 20(1): 80, 2022 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-35123484

RESUMO

BACKGROUND: Long noncoding RNA NEAT1 has been implicated in glioma progression. However, the effect of NEAT1 on glycolysis of glioma cell and the potential mechanism remain unclear. METHODS: In vitro experiments, including CCK-8, colony formation, ECAR, and lactate detection assays were performed to evaluate the effect of NEAT1 on proliferation and glycolysis of glioma cell. RNA pulldown and RIP assays were performed to identify the interaction between NEAT1 and PGK1. Truncated mutation of NEAT1 and PGK1 was used to confirm the specific interactive domains between NEAT1 and PGK1. Animal studies were performed to analyze the effect of NEAT1/PGK1 on glioma progression. RESULTS: NEAT1 knockdown significantly suppressed the proliferation and glycolysis of glioma cells. NEAT1 could specifically interact with PGK1, which promotes PGK1 stability. Hairpin A of NEAT1 is essential for interaction with M1 domain of PGK1. Depletion of NEAT1 markedly inhibited tumor growth in mice, while PGK1 could reverse this effect. Higher expression of NEAT1 was associated with poor overall survival of GBM patients. CONCLUSIONS: NEAT1 over expression promotes glioma progression through stabilizing PGK1. NEAT1/PGK1 axis is a candidate therapeutic target for glioma treatment.


Assuntos
Glioma , RNA Longo não Codificante , Animais , Linhagem Celular Tumoral , Proliferação de Células/genética , Regulação Neoplásica da Expressão Gênica , Glioma/patologia , Humanos , Camundongos , Fosfoglicerato Quinase/genética , Fosfoglicerato Quinase/metabolismo , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo
9.
Nan Fang Yi Ke Da Xue Xue Bao ; 29(2): 242-5, 2009 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-19246289

RESUMO

OBJECTIVE: To investigate the cerebral uptake and regional distribution of propofol when plasma propofol concentration reaches equilibrium in the internal carotid artery and internal jugular vein in dogs. METHODS: Eight male hybrid dogs aged 12-18 months weighing 10-12 kg were anesthetized with propofol at a single bolus (7 mg/kg) in 15 s followed by propofol infusion at a constant rate of 70 mg.kg(-1).h(-1) via the great saphenous vein of the right posterior limb. Blood samples were taken from the internal carotid artery and internal jugular vein at 30 min (T30) after propofol infusion for measurement of plasma propofol concentrations by high-pressure liquid chromatography (HPLC). The thalamus, epithalamus, metathalamus, hypothalamus, subthalamus, frontal lobe, parietal lobe, temporal lobe, hippocampus, cingulate gyrus, cerebellum, midbrain, pons, medulla oblongata and cervical cord were then dissected to determine propofol concentrations in these tissues by HPLC. RESULTS: The propofol concentrations in the internal carotid artery and internal jugular vein blood plasma were comparable at T30 (6.16-/+1.02 vs 6.17-/+1.00 microg/ml, P>0.05). The propofol concentration was 6.11-/+1.07 microg/g in the epithalamus, 6.14-/+0.98 microg/g in the metathalamus, 6.12-/+1.02 microg/g in the hypothalamus, 6.15-/+1.00 microg/g in the subthalamus, 6.20-/+1.03 microg/g in the frontal lobe, 6.18-/+1.02 microg/g in the parietal lobe, 6.13-/+1.00 microg/g in the temporal lobe, 6.07-/+0.99 microg/g in the hippocampus, 6.14-/+1.06 microg/g in the cingulate gyrus, 6.15-/+1.00 microg/g in the cerebellum, 6.13-/+1.05 microg/g in the midbrain, 6.18-/+1.01 microg/g in the pons, 6.15-/+0.93 microg/g in the medulla oblongata, and 6.13-/+1.00 microg/g in the cervical cord, showing no significant differences in the distributions (P>0.05). Propofol concentration in the thalamus (8.68-/+0.88 microg/g) was significantly higher than those in the other brain tissues (P<0.05). CONCLUSIONS: At the constant intravenous propofol injection rate of 70 mg.kg(-1).h(-1), plasma propofol concentration reaches equilibrium 30 min after the injection in the internal carotid artery and internal jugular vein with even distribution in the cerebral tissues in dogs, but the thalamus contains high propofol concentration.


Assuntos
Encéfalo/metabolismo , Artéria Carótida Interna/metabolismo , Veias Jugulares/metabolismo , Propofol/farmacocinética , Tálamo/metabolismo , Absorção , Anestésicos Intravenosos/sangue , Anestésicos Intravenosos/farmacocinética , Animais , Cães , Masculino , Propofol/sangue
10.
Nan Fang Yi Ke Da Xue Xue Bao ; 27(6): 836-8, 2007 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-17584652

RESUMO

OBJECTIVE: To investigate the cerebral distribution of propofol during continued infusion at a constant rate when the cerebral propofol uptake reaches equilibrium in dogs. METHODS: Six healthy 1-year-old male dogs were used in this study. The venous channel was established in the great saphenous vein of the right posterior limb. Anesthesia was induced with a single bolus injection of propofol (7 mg/kg), followed by propofol infusion at a constant rate of 70 mg/(kg.h) using a microinfusion pump. The blood samples were taken from the right internal carotid and internal jugular vein at 30 min (T30) and 50 min (T50) during propofol infusion for measurement of plasma propofol concentrations with high performance liquid chromatography (HPLC). At T50, the frontal lobe, parietal lobe, temporal lobe, hippocampus, cingulate gyrus, thalamus, midbrain, pons, and cerebellum were dissected respectively for determination of propofol concentrations. RESULTS: Propofol concentrations in the internal carotid artery and internal jugular vein blood plasma were 3.107-/+1.067, 3.095-/+1.085 microg/ml at T30 and 3.091-/+1.101, 3.117-/+1.091 microg/ml at T50, respectively, showing no significant differences (P>0.05). Propofol concentrations in the frontal lobe, parietal lobe, temporal lobe, hippocampus, cingulate gyrus, thalamus, midbrain, pons, cerebellum at T50 were 3.085-/+1.123, 3.116-/+1.125, 3.073-/+1.159, 3.117-/+1.090, 3.075-/+1.178, 3.073-/+1.146, 3.075-/+1.151, 3.102-/+1.174, and 3.072-/+1.192 microg/g respectively, suggesting homogeneous propofol distribution in these cerebral tissues (P>0.05). CONCLUSION: At T50, the cerebral uptake of propofol reached equilibrium when propofol is distributed homogeneously in the cerebral tissues in dogs.


Assuntos
Encéfalo/metabolismo , Propofol/farmacocinética , Anestésicos Intravenosos/administração & dosagem , Anestésicos Intravenosos/sangue , Anestésicos Intravenosos/farmacocinética , Animais , Artéria Carótida Interna/metabolismo , Cromatografia Líquida de Alta Pressão , Cães , Infusões Intravenosas , Veias Jugulares/metabolismo , Masculino , Propofol/administração & dosagem , Propofol/sangue , Distribuição Tecidual
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