210 research outputs found
Caractérisations diélectriques, expérimentations ex vivo et simulations multiphysiques de l'hyperthermie micro-ondes des tissus biologiques
Research and development of medical devices with various diagnostic and therapeutic applications have been carried out in different countries because of the great advances in electronic and electromagnetic devices during recent decades. However, at present, all of available existing microwave hyperthermia system can just offer treatment, by using high microwave power. In this thesis, a new microwave hyperemia system is researched which could have both diagnostic and therapeutic functions. One single applicator is used to measure dielectric properties of tissue with a very low harmless microwave power for diagnosis first. Then thermal therapeutic treatment will be carried out by using the same applicator with higher and adapted microwave power. Microwave broad band characterization of five different biological tissues at different temperatures with an openâended coaxial probe method and the virtual line model has been carried out. Ex vivo microwave hyperthermia experiments using microwave power of a few Watts at 2.45GHz have been carried out on five tissues of various thicknesses. Temperature evolution of the biological tissues has been measured by using an infra-red senor. Electromagnetic and thermal simulations for ex vivo microwave hyperthermia experiment have also been achieved by using COMSOL Multiphysics software with 2D axisymmetrical finiteâelement method and considering different tissues of various thicknesses and incident microwave powers. Simulation results correlate well with the experimental ones. This research, illustrates the possibility to have a flexible and feasible coaxial cable for both diagnosis and treatment for a minimally invasive therapy.La recherche et dĂ©veloppement de dispositifs mĂ©dicaux avec diverses applications en diagnostiques et en thĂ©rapie ont Ă©tĂ© rĂ©alisĂ©s. Actuellement, tous les systĂšmes micro-ondes disponibles d'hyperthermie proposent uniquement des traitements avec une puissance Ă©levĂ©e de micro-ondes. Dans cette thĂšse, un nouveau systĂšme d'hyperthermie micro-ondes est Ă©tudiĂ© pour le bĂ©nĂ©fice des fonctions de diagnostic et de thĂ©rapie. L'utilisation d'un applicateur avec un niveau trĂšs faible et inoffensif de puissance micro-ondes permet de faire le premier diagnostic. Le traitement thĂ©rapeutique thermique sera effectuĂ© en utilisant le mĂȘme applicateur avec une puissance micro-ondes Ă©levĂ©e et adaptĂ©e sur la partie pathologique. Des caractĂ©risations micro-ondes large bande de cinq tissus biologiques diffĂ©rents ont Ă©tĂ© effectuĂ©es Ă diffĂ©rentes tempĂ©ratures avec une mĂ©thode de sonde coaxiale ouverte et le modĂšle de ligne virtuelle. Les expĂ©rimentations ex vivo d'hyperthermie micro-ondes avec des puissances de quelques watts Ă 2,45GHz ont Ă©tĂ© rĂ©alisĂ©es sur ces tissus d'Ă©paisseurs variĂ©es. L'Ă©volution de la tempĂ©rature des tissus a Ă©tĂ© mesurĂ©e en utilisant un capteur infrarouge. Les simulations Ă©lectromagnĂ©tiques et thermiques pour les expĂ©rimentations ex vivo d'hyperthermie micro-ondes ont Ă©tĂ© effectuĂ©es en utilisant COMSOL Multiphysics avec la mĂ©thode des Ă©lĂ©ments finis et la symĂ©trie axiale 2D en considĂ©rant les tissus variĂ©s de diffĂ©rentes Ă©paisseurs et puissances micro-onde incidente. Les simulations du modĂšle correspondent bien aux mesures. Cette recherche illustre la possibilitĂ© d'avoir un cĂąble coaxial souple et adaptĂ© Ă la fois au diagnostic et au traitement pour une thĂ©rapie mini invasive
FACTS: Fully Automatic CT Segmentation of a Hip Joint
Extraction of surface models of a hip joint from CT data is a pre-requisite step for computer assisted diagnosis and planning (CADP) of periacetabular osteotomy (PAO). Most of existing CADP systems are based on manual segmentation, which is time-consuming and hard to achieve reproducible results. In this paper, we present a Fully Automatic CT Segmentation (FACTS) approach to simultaneously extract both pelvic and femoral models. Our approach works by combining fast random forest (RF) regression based landmark detection, multi-atlas based segmentation, with articulated statistical shape model (aSSM) based fitting. The two fundamental contributions of our approach are: (1) an improved fast Gaussian transform (IFGT) is used within the RF regression framework for a fast and accurate landmark detection, which then allows for a fully automatic initialization of the multi-atlas based segmentation; and (2) aSSM based fitting is used to preserve hip joint structure and to avoid penetration between the pelvic and femoral models. Taking manual segmentation as the ground truth, we evaluated the present approach on 30 hip CT images (60 hips) with a 6-fold cross validation. When the present approach was compared to manual segmentation, a mean segmentation accuracy of 0.40, 0.36, and 0.36 mm was found for the pelvis, the left proximal femur, and the right proximal femur, respectively. When the models derived from both segmentations were used to compute the PAO diagnosis parameters, a difference of 2.0 ± 1.5°, 2.1 ± 1.6°, and 3.5 ± 2.3% were found for anteversion, inclination, and acetabular coverage, respectively. The achieved accuracy is regarded as clinically accurate enough for our target applications
Chinese herbal medicine Guizhi Fuling Formula for treatment of uterine fibroids : a systematic review of randomized clinical trials
Background: Guizhi Fuling Formula is widely applied for uterine fibroids in China. Many clinical trials are reported. This study assessed the efficacy and safety of Guizhi Fuling Formula for the treatment of uterine fibroids. Methods: PubMed, Cochrane CENTRAL, EMBASE, and four Chinese databases were searched through May 2013. We included randomised controlled trials (RCTs) that tested Guizhi Fuling Formula for uterine fibroids, compared with no intervention, placebo, pharmaceutical medication, or other Chinese patent medicines approved by the State Food and Drug Administration of China. Authors extracted data and assessed the quality independently. We applied RevMan 5.2.0 software to analyse data of included randomised trials. Results: A total of 38 RCTs involving 3816 participants were identified. The methodological quality of the included trials was generally poor. Meta-analyses demonstrated that Guizhi Fuling Formula plus mifepristone were more effective than mifepristone alone in reducing the volume of fibroids (in total volume of multiple fibroids, MD â19.41 cm3, 95% CI â28.68 to â10.14; in average volume of multiple fibroids, MD â1.00 cm3, 95% CI â1.23
to â0.76; in average volume of maximum fibroids, MD â3.35 cm3, 95% CI â4.84 to â1.87, I2 = 93%, random effects model). Guizhi Fuling Formula significantly improved symptoms of dysmenorrhea either when it was used alone (RR 2.27, 95% CI 1.04 to 4.97) or in combination with mifepristone (RR 2.35, 95% CI 1.15 to 4.82). No serious adverse events were reported. Conclusions: Guizhi Fuling Formula appears to have additional benefit based on mifepristone treatment in
reducing volume of fibroids. However, due to high risk of bias of the trials, we could not draw confirmative conclusions on its benefit. Future clinical trials should be well-designed and avoid the issues that are identified in this study
Hepatoprotective mechanism of Silybum marianum on nonalcoholic fatty liver disease based on network pharmacology and experimental verification
The study aimed to identify the key active components in Silybum marianum (S. marianum) and determine how they protect against nonalcoholic fatty liver disease (NAFLD). TCMSP, DisGeNET, UniProt databases, and Venny 2.1 software were used to identify 11 primary active components, 92 candidate gene targets, and 30 core hepatoprotective gene targets in this investigation, respectively. The PPI network was built using a string database and Cytoscape 3.7.2. The KEGG pathway and GO biological process enrichment, biological annotation, as well as the identified hepatoprotective core gene targets were analyzed using the Metascape database. The effect of silymarin on NAFLD was determined using H&E on pathological alterations in liver tissues. The levels of liver function were assessed using biochemical tests. Western blot experiments were used to observe the proteins that were expressed in the associated signaling pathways on the hepatoprotective effect, which the previous network pharmacology predicted. According to the KEGG enrichment study, there are 35 hepatoprotective signaling pathways. GO enrichment analysis revealed that 61 biological processes related to the hepatoprotective effect of S. marianum were identified, which mainly involved in response to regulation of biological process and immune system process. Silymarin was the major ingredient derived from S. marianum, which exhibited the hepatoprotective effect by reducing the levels of ALT, AST, TC, TG, HDL-C, LDL-C, decreasing protein expressions of IL-6, MAPK1, Caspase 3, p53, VEGFA, increasing protein expression of AKT1. The present study provided new sights and a possible explanation for the molecular mechanisms of S. marianum against NAFLD
Catalytic oxidation of polymer used in oilfield by supported Co(II) complex within a high pH range
In this study, a clean oxidation process for the treatment of wastewater containing hydroxypropyl guar gum (HPGG) and other polymers under a high pH range was designed. For that, 5-sulfosalicylic acid (L)-Co(II) complex supported on bentonite (B) (B@Co(II)L) was prepared for treatment of wastewater by hydrogen peroxide (). The morphology and pore structure of B@Co(II)L was first characterized by scanning electron microscopy (SEM), powder X-ray diffraction (XRD), Fourier infrared spectrometer (FT-IR), and adsorptionâdesorption isotherms, after which the catalytic performance was investigated for the treatment of polymer wastewater. Results show that B@Co(II)L performed high catalytic performance in a wide range of 7.0 to 13.0. The viscosity of the HPGG can be decreased effectively from 22 to 2.5 mm/s under the optimal conditions of 45 °C, pH 10.0, 10% (mass ratio to HPGG), and 10% B@Co(II)L (mass ratio to ), and the removal rate for chemical oxygen demand (COD) of HPGG, CMC, and PAM reached to 95.9%, 94.8%, and 93.7%, respectively, within 240 min. Most of all, by applying the catalyst in the oilfield, it was found that the catalyst has high performance and the removal rate for COD of oilfield wastewater, fracturing fluids, and drilling fluid can be achieved by 92.1%, 94.2%, and 90.7%, respectively
Blocking CHOP-dependent TXNIP shuttling to mitochondria attenuates albuminuria and mitigates kidney injury in nephrotic syndrome
Albuminuria is a hallmark of glomerular disease of various etiologies. It is not only a symptom of glomerular disease but also a cause leading to glomerulosclerosis, interstitial fibrosis, and eventually, a decline in kidney function. The molecular mechanism underlying albuminuria-induced kidney injury remains poorly defined. In our genetic model of nephrotic syndrome (NS), we have identified CHOP (C/EBP homologous protein)-TXNIP (thioredoxin-interacting protein) as critical molecular linkers between albuminuria-induced ER dysfunction and mitochondria dyshomeostasis. TXNIP is a ubiquitously expressed redox protein that binds to and inhibits antioxidant enzyme, cytosolic thioredoxin 1 (Trx1), and mitochondrial Trx2. However, very little is known about the regulation and function of TXNIP in NS. By utilizin
Catalytic oxidation of polymer used in oilfield by supported Co(II) complex within a high pH range
In this study, a clean oxidation process for the treatment of wastewater containing hydroxypropyl guar gum (HPGG) and other polymers under a high pH range was designed. For that, 5-sulfosalicylic acid (L)-Co(II) complex supported on bentonite (B) (B@Co(II)L) was prepared for treatment of wastewater by hydrogen peroxide (). The morphology and pore structure of B@Co(II)L was first characterized by scanning electron microscopy (SEM), powder X-ray diffraction (XRD), Fourier infrared spectrometer (FT-IR), and adsorptionâdesorption isotherms, after which the catalytic performance was investigated for the treatment of polymer wastewater. Results show that B@Co(II)L performed high catalytic performance in a wide range of 7.0 to 13.0. The viscosity of the HPGG can be decreased effectively from 22 to 2.5 mm/s under the optimal conditions of 45 °C, pH 10.0, 10% (mass ratio to HPGG), and 10% B@Co(II)L (mass ratio to ), and the removal rate for chemical oxygen demand (COD) of HPGG, CMC, and PAM reached to 95.9%, 94.8%, and 93.7%, respectively, within 240 min. Most of all, by applying the catalyst in the oilfield, it was found that the catalyst has high performance and the removal rate for COD of oilfield wastewater, fracturing fluids, and drilling fluid can be achieved by 92.1%, 94.2%, and 90.7%, respectively
Statistical model-based segmentation of the proximal femur in digital antero-posterior (AP) pelvic radiographs
Purpose: Segmentation of the proximal femur in digital antero-posterior (AP) pelvic radiographs is required to create a three-dimensional model of the hip joint for use in planning and treatment. However, manually extracting the femoral contour is tedious and prone to subjective bias, while automatic segmentation must accommodate poor image quality, anatomical structure overlap, and femur deformity. A new method was developed for femur segmentation in AP pelvic radiographs. Methods: Using manual annotations on 100 AP pelvic radiographs, a statistical shape model (SSM) and a statistical appearance model (SAM) of the femur contour were constructed. The SSM and SAM were used to segment new AP pelvic radiographs with a three-stage approach. At initialization, the mean SSM model is coarsely registered to the femur in the AP radiograph through a scaled rigid registration. Mahalanobis distance defined on the SAM is employed as the search criteria for each annotated suggested landmark location. Dynamic programming was used to eliminate ambiguities. After all landmarks are assigned, a regularized non-rigid registration method deforms the current mean shape of SSM to produce a new segmentation of proximal femur. The second and third stages are iteratively executed to convergence. Results: A set of 100 clinical AP pelvic radiographs (not used for training) were evaluated. The mean segmentation error was 0.96 mm ± 0.35 mm , requiring < 5 s per case when implemented with Matlab. The influence of the initialization on segmentation results was tested by six clinicians, demonstrating no significance difference. Conclusions: A fast, robust and accurate method for femur segmentation in digital AP pelvic radiographs was developed by combining SSM and SAM with dynamic programming. This method can be extended to segmentation of other bony structures such as the pelvis
Statistical model-based segmentation of the proximal femur in digital antero-posterior (AP) pelvic radiographs
Purpose: Segmentation of the proximal femur in digital antero-posterior (AP) pelvic radiographs is required to create a three-dimensional model of the hip joint for use in planning and treatment. However, manually extracting the femoral contour is tedious and prone to subjective bias, while automatic segmentation must accommodate poor image quality, anatomical structure overlap, and femur deformity. A new method was developed for femur segmentation in AP pelvic radiographs. Methods: Using manual annotations on 100 AP pelvic radiographs, a statistical shape model (SSM) and a statistical appearance model (SAM) of the femur contour were constructed. The SSM and SAM were used to segment new AP pelvic radiographs with a three-stage approach. At initialization, the mean SSM model is coarsely registered to the femur in the AP radiograph through a scaled rigid registration. Mahalanobis distance defined on the SAM is employed as the search criteria for each annotated suggested landmark location. Dynamic programming was used to eliminate ambiguities. After all landmarks are assigned, a regularized non-rigid registration method deforms the current mean shape of SSM to produce a new segmentation of proximal femur. The second and third stages are iteratively executed to convergence. Results: A set of 100 clinical AP pelvic radiographs (not used for training) were evaluated. The mean segmentation error was 0.96 mm ± 0.35 mm , requiring < 5 s per case when implemented with Matlab. The influence of the initialization on segmentation results was tested by six clinicians, demonstrating no significance difference. Conclusions: A fast, robust and accurate method for femur segmentation in digital AP pelvic radiographs was developed by combining SSM and SAM with dynamic programming. This method can be extended to segmentation of other bony structures such as the pelvis
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Massive seasonal high-altitude migrations of nocturnal insects above the agricultural plains of East China
High-altitude, windborne movements of insects occur on an enormous scale, and have significant impacts on ecosystem function, provision of beneficial services, disease spread, and agricultural productivity. We used a combination of insect monitoring radar, balloon-borne nets, and searchlight traps to characterize the intensity, taxonomic composition, direction, and geographical extent of nocturnal insect âbioflowsâ occurring at heights to ~1 km above the agricultural lands of East China during spring, summer, and fall. We demonstrate seasonal northward and southward flows and show that the transport of insect biomass is considerably greater above this globally important food-production region than above the United Kingdom (the only other region where it has been quantified to date) and is dominated by species that are agricultural pests. Long-distance migrations of insects contribute to ecosystem functioning but also have important economic impacts when the migrants are pests or provide ecosystem services. We combined radar monitoring, aerial sampling, and searchlight trapping, to quantify the annual pattern of nocturnal insect migration above the densely populated agricultural lands of East China. A total of ~9.3 trillion nocturnal insect migrants (15,000 t of biomass), predominantly Lepidoptera, Hemiptera, and Diptera, including many crop pests and disease vectors, fly at heights up to 1 km above this 600 km-wide region every year. Larger migrants (>10 mg) exhibited seasonal reversal of movement directions, comprising northward expansion during spring and summer, followed by southward movements during fall. This northâsouth transfer was not balanced, however, with southward movement in fall 0.66Ă that of northward movement in spring and summer. Spring and summer migrations were strongest when the wind had a northward component, while in fall, stronger movements occurred on winds that allowed movement with a southward component; heading directions of larger insects were generally close to the track direction. These findings indicate adaptations leading to movement in seasonally favorable directions. We compare our results from China with similar studies in Europe and North America and conclude that ecological patterns and behavioral adaptations are similar across the Northern Hemisphere. The predominance of pests among these nocturnal migrants has severe implications for food security and grower prosperity throughout this heavily populated region, and knowledge of their migrations is potentially valuable for forecasting pest impacts and planning timely management actions
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