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1.
Sensors (Basel) ; 22(13)2022 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-35808527

RESUMO

Blockchain has become one of the key techniques for the security of the industrial internet. However, the blockchain is vulnerable to FAW (Fork after Withholding) attacks. To protect the industrial internet from FAW attacks, this paper proposes a novel FAW attack protection algorithm (FAWPA) based on the behavior of blockchain miners. Firstly, FAWPA performs miner data preprocessing based on the behavior of the miners. Then, FAWPA proposes a behavioral reward and punishment mechanism and a credit scoring model to obtain cumulative credit value with the processed data. Moreover, we propose a miner's credit classification mechanism based on fuzzy C-means (FCM), which combines the improved Aquila optimizer (AO) with strong solving ability. That is, FAWPA combines the miner's accumulated credit value and multiple attack features as the basis for classification, and optimizes cluster center selection by simulating Aquila's predation behavior. It can improve the solution update mechanism in different optimization stages. FAWPA can realize the rapid classification of miners' credit levels by improving the speed of identifying malicious miners. To evaluate the protective effect of the target mining pool, FAWPA finally establishes a mining pool and miner revenue model under FAW attack. The simulation results show that FAWPA can thoroughly and efficiently detect malicious miners in the target mining pool. FAWPA also improves the recall rate and precision rate of malicious miner detection, and it improves the cumulative revenue of the target mining pool. The proposed algorithm performs better than ND, RSCM, AWRS, and ICRDS.


Assuntos
Blockchain , Mineradores , Algoritmos , Humanos , Mineração
2.
Sensors (Basel) ; 22(23)2022 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-36501830

RESUMO

In the blockchain system, mining pools are popular for miners to work collectively and obtain more revenue. Nowadays, there are consensus attacks that threaten the efficiency and security of mining pools. As a new type of consensus attack, the Fork After Withholding (FAW) attack can cause huge economic losses to mining pools. Currently, there are a few evaluation tools for FAW attacks, but it is still difficult to evaluate the FAW attack protection capability of target mining pools. To address the above problem, this paper proposes a novel evaluation framework for FAW attack protection of the target mining pools in blockchain systems. In this framework, we establish the revenue model for mining pools, including honest consensus revenue, block withholding revenue, successful fork revenue, and consensus cost. We also establish the revenue functions of target mining pools and other mining pools, respectively. In particular, we propose an efficient computing power allocation optimization algorithm (CPAOA) for FAW attacks against multiple target mining pools. We propose a model-solving algorithm based on improved Aquila optimization by improving the selection mechanism in different optimization stages, which can increase the convergence speed of the model solution and help find the optimal solution in computing power allocation. Furthermore, to greatly reduce the possibility of falling into local optimal solutions, we propose a solution update mechanism that combines the idea of scout bees in an artificial bee colony optimization algorithm and the constraint of allocating computing power. The experimental results show that the framework can effectively evaluate the revenue of various mining pools. CPAOA can quickly and accurately allocate the computing power of FAW attacks according to the computing power of the target mining pool. Thus, the proposed evaluation framework can effectively help evaluate the FAW attack protection capability of multiple target mining pools and ensure the security of the blockchain system.


Assuntos
Blockchain , Utensílios Domésticos , Algoritmos , Consenso
3.
Transp Policy (Oxf) ; 129: 78-89, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36250134

RESUMO

The COVID-19 pandemic has stifled international trade and the global maritime industry. Its impact on the routing of the regional vessel traffic flow provides supportive data to port authorities, ship owners, shippers, and consignees. This study proposes a spatiotemporal dynamic graph neural network (STDGNN) model that includes the usual primary part of the vessel flow and an auxiliary part of newly confirmed COVID-19 cases near the port. The primary part consists of a time-embedding (TE) block, two dynamic graph neural network (DGNN) blocks, and a gated recurrent unit block, to capture the spatiotemporal dependence in the regional vessel traffic flow. The auxiliary part is made of multiple blocks to exploit the dynamic temporal relationships in hours, days, and weeks. Moreover, the performance of the STDGNN model is verified by utilising real vessel traffic flow data (i.e. inflow, outflow, and volume) and the new cases of COVID-19 near the port of New York, USA, provided by the automatic identification system and the Johns Hopkins University Centre for Systems Science and Engineering. The 2-h prediction result shows a 37.7%, 17.23%, and 11.4% improvement in the mean absolute error (MAE) over the gated recurrent unit (GRU), STGCN, and TGCN models, respectively. The delicate and adaptable prediction of vessel traffic flow could help the port relieve congestion, enhance efficiency, and further assist the recovery of regional maritime industries in the post-COVID era.

4.
Phys Chem Chem Phys ; 23(42): 24328-24335, 2021 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-34673863

RESUMO

Thermoelectric materials are promising for energy harvesting using waste heat. The thermal management of the thermoelectric materials attract scientific and technological interests. The narrow bandgap semiconductor BiAgSe2 is a good candidate for thermoelectric materials due to its ultralow thermal conductivity. The mother compound BiAgSe2 crystallizes in hexagonal symmetry at room temperature, but experiences structural transitions to cubic phase at high temperature. By contrast, the daughter compound BiAgSeTe exhibits long range ordering and crystallizes into cubic phase at room temperature. Nevertheless, the local structural disorderings due to the Bi3+ and Ag+ anti-site defects, as well as local structural distortions, are ubiquitous in both parent BiAgSe2 and BiAgSeTe. BiAgSeTe exhibits distinct transport properties owing to the disordering-induced drastic changes in the electronic band structure, as well as the scattering dictated by the point defects. It is suggested that BiAgSe2 and BiAgSeTe could be good candidates for phonon glass and crystal glass (PGEC)-type thermoelectrics.

5.
Phys Chem Chem Phys ; 22(17): 9362-9367, 2020 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-32309829

RESUMO

The quaternary chalcogenides consisting of earth-abundant elements such as Cu2ZnSnSe4 (CZTSe) have promising electrical and optical properties prompting enormous technological interest. Understanding different types of defects including Cu/Zn ordering is believed to be the key point to tackle technological challenges such as a large open circuit voltage deficit in CZTSe. The Te doped Cu2.2Zn0.8SnSe4-xTex (x = 0.01-0.04) were investigated using X-ray absorption fine structure spectroscopy at the Cu, Zn, and Se K-edges as well as at the Te L3-edge. Cu at the zinc site with anti-site defects and oxygen interstitials are identified. The detailed electronic structure upon Te doping is studied, providing insights into the rich defect chemistry present in this compound.

6.
Phys Chem Chem Phys ; 20(13): 8488-8497, 2018 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-29537014

RESUMO

Porphyrin-based supramolecular nanoassemblies of a spherical morphology have been attracting broad interest owing to their wide application possibilities in numerous fields of paramount significance. Most of the existing assembly protocols, however, either suffer from the requirement of elaborately-designed yet tediously-synthesized ad hoc porphyrins, the use of surfactant templates, or accurate consideration of the experimental parameters etc. The initiation of a facile surfactant-free fabrication protocol performable under ambient conditions using commercial porphyrins as building blocks is strongly desired. We herein report that a commercial metal-free porphyrins, 5,10,15,20-tetrakis(4-aminophenyl)porphyrin (TPPNH2), could be facilely organized to form well-defined discrete spherical nanoassemblies at room temperature by means of a simple reprecipitation method. We further find that the as-manufactured TPPNH2 nanospheres could work as photocatalysts towards the reduction of potassium tetrachloroplatinate(ii), leading to their self-platinization and the production of platinum/porphyrin nanosphere nanocomposites, wherein ultrathin Pt nanoparticles of a size of ca. 3 nm are immobilized on the porphyrin nanospheres. Significantly, by taking the advantage of their easy sedimentation from aqueous suspensions, we show that the as-produced composites could serve as qualified heterogeneous nanocatalysts in terms of their excellent catalytic stability and recyclability towards the reduction of 4-nitrophenol, where the catalytic reactivity exhibits only trivial changes even after the reactions have been repeated 8 times continuously. Taking into account the general concerns of porphyrins- and Pt-based nanostructures, this might provide a facile method for the construction of spherical porphyrin nanostructures with self-platinization capability. Meanwhile, considering the high cost and scarcity of Pt, our nanocomposites with excellent stability and recyclability likely have a bright future of potential uses.

7.
Pak J Med Sci ; 34(3): 638-642, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30034430

RESUMO

OBJECTIVE: To study the biomechanical properties of different suture methods, and to provide evidence for the clinical application of this suture methods in repairing acute Achilles tendon rupture. METHODS: Twenty four fresh frozen cadaver Achilles tendon specimens were collected and randomly divided into three groups (n=8), Group-A Bunnell suture method, Group-B Bosworth suture and Group-C anchor suture respectively. 5 N tensions were applied to tighten the tendon. The actual length of the tendon between the upper and lower clips was measured with a ruler. The length of the long axis and the short axis of the three sections of the tendon was measured by vernier caliper. The cross sectional area of the tendon was calculated according to the elliptical area formula and the mean value was obtained. RESULTS: There was no significant difference in the length and cross-sectional area of each tendon among three groups (F=0.26, P=0.86; F=0.09, P=0.96). There was no significant difference in the maximum load of tendon and failure displacement in Group A and B (P>0.05). The maximal load of Group-C was significantly larger than that of Group A and B (P<0.05), and there was no significant difference between the failure displacement and Group A and B (P>0.05). CONCLUSION: Three suture methods can provide good biomechanical properties, but the anchor suture is more effective in solving the shortcomings of traditional methods. It is a safe and effective method, and is worthy of promotion.

8.
Indian J Microbiol ; 56(2): 214-218, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27570314

RESUMO

Nitric oxide (NO) is a small molecule with a wide range of biological activities in mammalian and bacteria. However, the role of NO in fungi, especially Candida albicans, is not clear. In this study, we confirmed the generation of endogenous NO in C. albicans, and found that the production of endogenous NO in C. albicans was associated with nitric oxide synthase pathway. Our results further indicated that the production of endogenous NO in C. albicans was reduced under oxidative stress such as menadione or H2O2 treatment. Meanwhile, exogenous NO donor, sodium nitroprusside (SNP), synergized with H2O2 against C. albicans. Interestingly, SNP could inhibit the antifungal effect of azoles against C. albicans in vitro, suggesting that NO might be involved in the resistance of C. albicans to antifungals. Collectively, this study demonstrated the production of endogenous NO in C. albicans, and indicated that NO may play an important role in the response of C. albicans to oxidative stress and azoles.

9.
Phys Chem Chem Phys ; 17(38): 25182-90, 2015 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-26352766

RESUMO

Ag/AgCl-based plasmonic photocatalysts have received much attention as emerging visible-light-driven photocatalysts, wherein those characterized by 1D morphology have aroused great expectations. Most of the current existing protocols for the fabrication of 1D materials, however, suffer from either multistep tedious synthesis processes or the requirement of rigorous experimental conditions. A one-pot fabrication method feasible under ambient conditions is strongly desired. By means of a surfactant-assisted protocol, we report herein that Ag/AgCl structures of near-spherical and 1D morphology could be controllably produced. We show that near-spherical Ag/AgCl species could be produced immediately after dropping an AgNO3 aqueous solution into an aqueous solution of cetyltrimethylammonium chloride (CTAC) surfactant under stirring. Interestingly, we show that these initially formed near-spherical species could automatically evolve into 1D Ag/AgCl fibers simply by extending the stirring time under ambient conditions. In our new protocol, CTAC works not only as a chlorine source but also as a directing reagent to assist the formation of 1D Ag/AgCl structures. Moreover, we demonstrate that compared to near-spherical structures, our Ag/AgCl fibers could display boosted catalytic performances towards the photodegradation of the methyl orange pollutant under visible light irradiation. Our work might launch an easy method for the construction of fibrous Ag/AgCl architectures of superior photocatalytic reactivity, and it also provides deep insights into the surfactant-assisted synthesis.

10.
Pak J Med Sci ; 30(4): 773-7, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25097515

RESUMO

Objective : To summarize the functional outcome of tarsometatarsal joint fracture-dislocation managed according to Myerson classification. Methods : Total eighty cases of tarsometatarsal joint fracture-dislocation were treated from Mar 2004 to Feb 2012. According to the Myerson classification, there were 14 cases in type A, 12 cases in type B1, 28 cases in type B2, 11 cases in type C1 and 15 cases in type C2. All the cases were treated with open reduction and internal fixation and the incisions and implants were also selected according to the Myerson classification. X-ray was examined during the follow-up period and functional evaluation was carried out by American Orthopaedic Foot and Ankle Society (AOFAS) midfoot score system. Analysis of variance was used to test the different types of Myerson classification. Results : Sixty eight patients got a mean follow-up of 24 months (15-36 months). No patient suffered from infection, skin flap necrosis and X-ray showed there were no implants loosening or breakage. The mean AOFAS score was 88.4(47-100) and excellent and good result was 89.7%. The differences among Myerson classifications showed that there were statistical significance between type B and type A, type C (P<0.05) Three patients suffered from severe pain and difficult walking, X-ray showed the ambiguity of the joint space, which can be diagnosed as posttraumatic arthritis. One patient had arthrodesis finally. Conclusion : The Myerson classification is helpful to make preoperative plan and judging prognosis to the tarsometatarsal joint injuries. In type B, single or double incisions with screw or plate fixation is enough, while in type A and type C, double or triple incisions with screw or plate fixation in medial joints and Kirschner wire fixation in lateral joints are needed. Postoperatively, the type B patients had better prognosis than type A and type C patients. However, the concomitant injuries around the tarsometatarsal joint were not included in Myerson classification, which is the limitation but cannot be neglected.

11.
Sci Rep ; 14(1): 6170, 2024 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-38486035

RESUMO

Employee scheduling aims to assign employees to shifts to satisfy daily workload and constraints. Some employee scheduling problems and their variants have been proven NP-hard, and a series of works have been done. However, the existing algorithms consider the fixed work time, which may cause plenty of overstaffing and understaffing phenomenons. Hence, this paper proposes a fast-flexible strategy based approach (FFS) to solve it. FFS introduces the idea of soft work time, which allows the work time of employees can be adjusted in a range. Based on this, we set the flextime strategy to decide the specific work time of each employee every day. Besides, FFS adopts a pairwise-allocated strategy and proficiency average matrix to boost its efficiency and effectiveness. Finally, the extensive experimental evaluation shows that FFS is more effective and efficient than the baselines for solving the employee scheduling problem considering soft work time.

12.
Indian J Ophthalmol ; 72(Suppl 2): S265-S272, 2024 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-38271422

RESUMO

PURPOSE: To evaluate the myopia risk in school-aged children one year after lifting a pandemic-related lockdown and develop a tool to identify high-risk groups. METHODS: In total, 38,079 children without myopia from 38 schools were included. The outcomes were myopia incidence and progression in 1 year after the COVID-19 lockdown was lifted, both obtained by the spherical equivalent refraction (SER). We separated the population into an exploratory (75%) and a validation sample (25%) to construct the risk score model. RESULTS: In total, 9811 (29.57%) students became myopic, and the overall myopia progression was 0.22 ± 0.62 D. Even less myopia progression was noted in the pre-myopia group at baseline (All: P = 0.045, Boy: P = 0.005). The risk score model included seven predictors: gender, grade, SER at baseline, residence, parental myopia, eye discomfort symptoms, and online courses. The model had a score range of 0-46 and an optimal cutoff of 34. The area under the receiver operating curve of the model was 0.726 (0.719-0.732) for the exploratory sample and 0.731 (0.720-0.742) for the validation sample. CONCLUSIONS: The risk score can serve as a practical tool for classifying the risk of myopia in school-aged children.


Assuntos
Miopia , Masculino , Criança , Humanos , Estudos de Coortes , Miopia/diagnóstico , Miopia/epidemiologia , Refração Ocular , China/epidemiologia , Fatores de Risco
13.
Int J Cancer ; 132(1): 128-36, 2013 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-22674195

RESUMO

The aberrant expression of microRNAs (miRNAs) is associated with a variety of diseases, including cancer. In our study, we examined the miRNA expression profile of meningiomas, which is a common type of benign intracranial tumor derived from the protective meninges membranes that surround the brain and spinal cord. To define a typical human meningioma miRNA profile, the expression of 200 miRNAs in a training sample set were screened using quantitative reverse transcription polymerase chain reaction analysis, and then significantly altered miRNAs were validated in a secondary independent sample set. Kaplan-Meier and univariate/multivariate Cox proportional hazard regression analyses were performed to assess whether miRNA expression could predict the recurrence of meningioma after tumor resection. After a two-phase selection and validation process, 14 miRNAs were found to exhibit significantly different expression profiles in meningioma samples compared to normal adjacent tissue (NAT) samples. Unsupervised clustering analysis indicated that the 14-miRNA profile differed between tumor and NAT samples. Downregulation of miR-29c-3p and miR-219-5p were found to be associated with advanced clinical stages of meningioma. Kaplan-Meier analysis showed that high expression of miR-190a and low expression of miR-29c-3p and miR-219-5p correlated significantly with higher recurrence rates in meningioma patients. Cox proportional hazard regression analysis revealed that miR-190a expression level is an important prognostic predictor that is independent of other clinicopathological factors. Our results suggest that the use of miRNA profiling has significant potential as an effective diagnostic and prognostic marker in defining the expression signature of meningiomas and in predicting postsurgical outcomes.


Assuntos
Neoplasias Meníngeas/genética , Meningioma/genética , Meningioma/patologia , MicroRNAs/biossíntese , Recidiva Local de Neoplasia/genética , Recidiva Local de Neoplasia/patologia , Adolescente , Adulto , Idoso , Criança , Análise por Conglomerados , Regulação para Baixo , Feminino , Seguimentos , Perfilação da Expressão Gênica/métodos , Humanos , Estimativa de Kaplan-Meier , Masculino , Neoplasias Meníngeas/metabolismo , Neoplasias Meníngeas/patologia , Meningioma/metabolismo , MicroRNAs/genética , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/metabolismo , Prognóstico , Modelos de Riscos Proporcionais , Adulto Jovem
14.
Photoacoustics ; 29: 100442, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36589516

RESUMO

The standard reconstruction of Photoacoustic (PA) computed tomography (PACT) image could cause the artifacts due to interferences or ill-posed setup. Recently, deep learning has been used to reconstruct the PA image with ill-posed conditions. In this paper, we propose a jointed feature fusion framework (JEFF-Net) based on deep learning to reconstruct the PA image using limited-view data. The cross-domain features from limited-view position-wise data and the reconstructed image are fused by a backtracked supervision. A quarter position-wise data (32 channels) is fed into model, which outputs another 3-quarters-view data (96 channels). Moreover, two novel losses are designed to restrain the artifacts by sufficiently manipulating superposed data. The experimental results have demonstrated the superior performance and quantitative evaluations show that our proposed method outperformed the ground-truth in some metrics by 135% (SSIM for simulation) and 40% (gCNR for in-vivo) improvement.

15.
Medicine (Baltimore) ; 102(51): e36633, 2023 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-38134108

RESUMO

BACKGROUND: To compare the effects of stepwise intracranial decompression (SID) and decompressive craniectomy (DC) on severe traumatic brain injury. METHODS: This prospective randomized study was conducted at The Third Affiliated Hospital of Soochow University. Ninety two patients were divided into 2 groups according to the random number table method. The study group received SID, whereas the control group received DC. The surgical time and intraoperative bleeding of the 2 groups of patients were recorded, neurological function and glasgow coma score before and after treatment in both groups, incidence of complications, prognostic situation, and levels of brain oxygen metabolism indicators before and after treatment. RESULTS: Among the 92 patients who agreed, 46 were assigned to the study and control groups, and 6 patients were excluded. Finally, 86 patients were analyzed, including 43 in the study group and 43 in the control group. After treatment, the glasgow coma score scores of the 2 groups increased compared to before treatment; the study group had a higher score, The National Institutes of Health Stroke Scale score decreased compared to before treatment, and the study group had a lower score (P < .05). The incidence of complications in the study group (4.65%) was significantly lower than that in the control group (18.60%) (P < .05). The good prognosis rate of the research group (41.86%) was significantly higher than that of the control group (16.28%) (P < .05). CONCLUSION: Compared with DC, using SID to treat severe traumatic brain injury can shorten surgical time and reduce intraoperative bleeding, more effectively improve patients neurological function and consciousness state, reduce the incidence of complications, and regulate brain oxygen metabolism status, which is beneficial for improving prognosis and ensuring a good outcome of the disease.


Assuntos
Lesões Encefálicas Traumáticas , Craniectomia Descompressiva , Humanos , Craniectomia Descompressiva/métodos , Estudos Prospectivos , Coma , Lesões Encefálicas Traumáticas/cirurgia , Oxigênio , Descompressão , Resultado do Tratamento
16.
Plast Reconstr Surg ; 152(1): 98-107, 2023 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-36728660

RESUMO

BACKGROUND: Wound healing is a widespread health problem that imposes a financial burden on health systems. Cell therapy with genetically modified adipose-derived stem cells (ADSCs) is a promising strategy for dysregulated wound repair. E2F transcription factor 1 (E2F1) is a bidirectional regulator of cytokines. Here, the authors aimed to investigate the impact and potential mechanism of E2F1 -/- ADSCs in promoting the wound healing process. METHODS: Forty-five C57BL/6 mice (specific pathogen-free, male) with 10-mm full-thickness wounds were randomly treated with subcutaneous injection of 2 × 10 6 wild-type ADSCs, 2 × 10 6 E2F1 -/- ADSCs, or phosphate-buffered saline. The wound closure rate was monitored at days 0, 3, 7, 10, and 14 after treatment. The collagen synthesis, angiogenesis, and wound contraction were calculated by Masson, immunohistochemistry, and immunofluorescent staining (CD31 and KI67), Western blotting (α-smooth muscle actin, collagen I, vascular endothelial growth factor, and transforming growth factor-ß1) separately at day 14. In vitro, the conditioned media (CM) of wild-type ADSCs and E2F1 -/- ADSCs were collected to evaluate the impact on proliferation, migration, and angiogenesis. RESULTS: In vivo, the E2F1 -/- ADSC group exhibited increased healing rate, proliferating vessels, and collagen synthesis compared with control at day 14 ( P < 0.05). Moreover, E2F1 -/- ADSCs showed enhanced vascular endothelial growth factor and transforming growth factor-ß1 expression in the wound site and CM, and the CM from E2F1 -/- ADSCs promoted the proliferation, migration, and tube formation of co-cultured cells in vitro ( P < 0.05). CONCLUSION: The E2F1 -/- ADSCs exhibited a strong paracrine ability to improve the vascularization process and collagen deposition, thereby accelerating wound healing in the rodent model. CLINICAL RELEVANCE STATEMENT: These findings show that targeting transcription factor E2F1 could regulate the paracrine function of ADSCs, developing E2F1-modified ADSCs as an effective therapeutic option for wound healing and regeneration.


Assuntos
Fator de Crescimento Transformador beta1 , Fator A de Crescimento do Endotélio Vascular , Camundongos , Masculino , Animais , Fator A de Crescimento do Endotélio Vascular/metabolismo , Fator de Crescimento Transformador beta1/metabolismo , Camundongos Endogâmicos C57BL , Colágeno/metabolismo , Células-Tronco/metabolismo , Tecido Adiposo/metabolismo
17.
Photoacoustics ; 31: 100517, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37292518

RESUMO

Photoacoustic tomography (PAT) is a newly developed medical imaging modality, which combines the advantages of pure optical imaging and ultrasound imaging, owning both high optical contrast and deep penetration depth. Very recently, PAT is studied in human brain imaging. Nevertheless, while ultrasound waves are passing through the human skull tissues, the strong acoustic attenuation and aberration will happen, which causes photoacoustic signals' distortion. In this work, we use 180 T1 weighted magnetic resonance imaging (MRI) human brain volumes along with the corresponding magnetic resonance angiography (MRA) brain volumes, and segment them to generate the 2D human brain numerical phantoms for PAT. The numerical phantoms contain six kinds of tissues, which are scalp, skull, white matter, gray matter, blood vessel and cerebrospinal fluid. For every numerical phantom, Monte-Carlo based optical simulation is deployed to obtain the photoacoustic initial pressure based on optical properties of human brain. Then, two different k-wave models are used for the skull-involved acoustic simulation, which are fluid media model and viscoelastic media model. The former one only considers longitudinal wave propagation, and the latter model takes shear wave into consideration. Then, the PA sinograms with skull-induced aberration is taken as the input of U-net, and the skull-stripped ones are regarded as the supervision of U-net to train the network. Experimental result shows that the skull's acoustic aberration can be effectively alleviated after U-net correction, achieving conspicuous improvement in quality of PAT human brain images reconstructed from the corrected PA signals, which can clearly show the cerebral artery distribution inside the human skull.

18.
Zhongguo Zhong Yao Za Zhi ; 37(11): 1655-8, 2012 Jun.
Artigo em Zh | MEDLINE | ID: mdl-22994002

RESUMO

OBJECTIVE: To explore the expression of inducible nitric oxide synthase (iNOS) in restenosis rats and function of Astragalus membranaceus and Angelica sinensis. METHOD: The restenosis model was established by denuding aorta endothelium, rats were randomly divided into control group, model group, A. membranaceus treatment group, A. sinensis treatment group, combined A. membranaceus with A. sinensis treatment group. After intramuscular injection of drugs for 21 dayss, the changes of iNOS in restenosis rats were observed by histomorphology and immunohistochemisty, the effects of A. membranaceus and A. sinensis on iNOS in restenosis rats was also investigated. RESULT: A small quantity of iNOS were detected in the intima and media of normal aorta, the expression of iNOS was increased on 3 day after denuding aorta endothelium, the expression of iNOS increasd and the color darken along with injury damage and intima thickening. Compared with model group, the expression of iNOS decreasd in A. membranaceus, A. sinensis treated group, A. membranaceus and A. sinensis treated group changed more significantly. CONCLUSION: iNOS was involved in blood vessel restenosis by denuding aorta endothelium, A. membranaceus, A. sinensis could inhibit intimal proliferation through iNOS.


Assuntos
Angelica sinensis/química , Astrágalo/química , Medicamentos de Ervas Chinesas/farmacologia , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Óxido Nítrico Sintase Tipo II/metabolismo , Animais , Constrição Patológica/tratamento farmacológico , Constrição Patológica/enzimologia , Medicamentos de Ervas Chinesas/uso terapêutico , Masculino , Ratos , Ratos Sprague-Dawley
19.
Adv Sci (Weinh) ; 9(1): e2103632, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34716685

RESUMO

Organic compounds bearing redox-active ionic pairs as electrode materials for high-performance rechargeable batteries have gained growing attention owing to the properties of synthetic tunability, high theoretical capacity, and low solubility. Herein, an innovative biredox-ionic composite, i.e., ethylviologen dianthraquinone-2-sulfonate (EV-AQ2 ), affording multiple and reversible active sites as a cathode material in lithium-organic batteries is reported. EV-AQ2 exhibits a high initial capacity of 199.2 mAh g-1 at 0.1 C rate, which corresponds to the transfer of two electrons from one redox couple EV2+ /EV0 and four electrons from two redox-active AQ- anions. It is notable that EV-AQ2 shows remarkably improved cyclability compared to the precursors. The capacity retention is 89% and the Coulombic efficiency approaches 100% over 120 cycles at 0.5 C rate. The results offer evidence that AQ- into the EV2+ scaffold with multiple redox sites are promising in developing high-energy-density organic rechargeable batteries.

20.
Coron Artery Dis ; 31(1): e87-e93, 2022 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-34292180

RESUMO

BACKGROUND: Inflammation plays an important role in acute myocardial infarction (AMI). Procalcitonin levels rise in response to proinflammatory stimuli. This study aimed to investigate the effects of different doses of atorvastatin on the serum inflammatory profiles, especially procalcitonin and major adverse cardiovascular events (MACEs) in patients with AMI during hospitalization. METHODS: The patients who were admitted to the Coronary Care Unit of The Third Medical Center of PLA General Hospital (Beijing, China) between January 2015 and December 2015 with a diagnosis of AMI were enrolled, and randomized to atorvastatin 20 mg/day postoperatively (20-mg group), 40 mg/day postoperatively (40-mg group) and 80 mg preoperatively+40 mg/day postoperatively (80/40-mg group). Serum procalcitonin and high-sensitivity C-reactive protein (hs-CRP) were evaluated before and at 1 and 3 days after percutaneous coronary intervention (PCI). RESULTS: A total of 112 patients with AMI (23 women and 89 men) were prospectively eligible for the study. There were no significant differences in most clinical data among the three groups. The 80/40-mg group showed significantly reduced serum procalcitonin levels at 1 and 3 days after PCI (P < 0.001) and reduced hs-CRP levels at 3 days P = 0.001) compared with 20-mg and 40-mg groups. Serum procalcitonin (OR, 4.593; 95% CI, 1.476-8.387; P = 0.005), hs-CRP (OR, 1.149; 95% CI, 1.012-1.338; P = 0.018), highly sensitive cardiac troponin T (OR, 1.255; 95% CI, 1.004-1.569, P = 0.009) and Gensini score (OR, 1.022; 95% CI, 1.045-1.062; P = 0.013) were independently associated with MACEs during hospitalization. CONCLUSION: The use of atorvastatin 80 mg before and 40 mg/day after PCI in patients with AMI can effectively reduce serum inflammatory factors. procalcitonin and hs-CRP were independently associated with in-hospital MACEs.


Assuntos
Atorvastatina/farmacologia , Doenças Cardiovasculares/complicações , Pró-Calcitonina/efeitos dos fármacos , Idoso , Atorvastatina/uso terapêutico , Pequim , Biomarcadores/análise , Biomarcadores/sangue , Doenças Cardiovasculares/sangue , Doenças Cardiovasculares/mortalidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Valor Preditivo dos Testes , Pró-Calcitonina/análise , Pró-Calcitonina/sangue , Prognóstico
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