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Objective: To explore the relationship between clinicopathological features, treatment and prognosis of patients with malignant mesothelioma, and provide theoretical basis for the prevention and treatment of malignant mesothelioma. Methods: In November 2022, the clinical data of 37 patients with malignant mesothelioma diagnosed in Qingdao Central Hospital from July 2014 to November 2022 were retrospectively analyzed, and the prognostic factors were analyzed by Kaplan-Meier and log-rank tests. Results: The median age of the 37 patients was 66 years old, all patients were confirmed by pathology. The median survival time of all patients was 30.00 months. The 1-year, 2-year, 3-year and 5-year cumulative survival rates were 70.27% (26/37), 48.65% (18/37), 16.22% (6/37) and 13.51% (5/37), respectively. Compared with different treatments, the median survival time of palliative care patients was 5.00 months, which was significantly lower than that of operation group (30.33 months), chemotherapy group (30.00 months), surgery combined with chemotherapy group (30.00 months) and chemotherapy combined with bevacizumab targeted therapy group (47.42 months) (P<0.05). Gender, age (≥60 years old or <60 years old), smoking history, occupational exposure history, disease site, and surgical history were not factors affecting the survival of malignant mesothelioma patients (P>0.05) . Conclusion: The clinical symptoms of malignant mesothelioma are not specific, but early initiation of treatment can still prolong survival, and chemotherapy combined with anti-vascular targeted therapy shows better therapeutic effect.
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Neoplasias Pulmonares , Mesotelioma Maligno , Mesotelioma , Neoplasias Pleurais , Humanos , Idoso , Pessoa de Meia-Idade , Mesotelioma/tratamento farmacológico , Estudos Retrospectivos , Prognóstico , Análise de Sobrevida , Taxa de SobrevidaRESUMO
Objective: To observe the effect of lipid regulating therapy on carotid atherosclerotic plaque in diabetic patients. Methods: The REACH study, conducted between March 2009 and February 2012, enrolled asymptomatic patients with magnetic resonance imaging (MRI) confirmed carotid atherosclerotic plaque, who had never taken lipid-lowering drugs. Patients were treated with a moderate dose of rosuvastatin for 24 months. Blood lipid levels were measured and carotid MRI was performed at baseline, 3 and 24 months after treatment. The volume of carotid wall and lipid-rich necrotic core (LRNC) were measured by image analysis software. This study retrospectively analyzed patients in the REACH study. Patients were divided into diabetes group and non-diabetic group. The changes of blood lipid level and MRI parameters of carotid atherosclerotic plaque were compared between the two groups and their correlation was analyzed. Results: A total of 38 patients with carotid atherosclerotic plaque were included in this study, including 13 patients (34.2%) in the diabetic group and 25 patients (65.8%) in the non-diabetic group. Baseline parameters were comparable between the two groups, except higher HbA1c level in diabetes group (P<0.05). Compared with baseline, the total cholesterol (TC), low density lipoprotein cholesterol (LDL-C) and triglyceride (TG) levels were significantly decreased at 3 and 24 months in both two groups (P<0.05). The change of high-density lipoprotein cholesterol (HDL-C) in diabetes group was not obvious, while it was significantly increased in non-diabetic group at 24 months ((1.38±0.33) mmol/l vs. (1.26±0.26) mmol/l, P<0.05). MRI results showed that the volume and percentage of LRNC remained unchanged at 3 months, slightly decreased at 24 months (64.86 (45.37, 134.56) mm3 vs. 75.76 (48.20, 115.64) mm3, P>0.05) and (15.84% (11.47%, 24.85%) vs. 16.95% (11.64%, 22.91%), P>0.05) in diabetic group. In non-diabetic group, the volume and percentage of LRNC were significantly decreased at 3 months (63.01 (44.25, 188.64) mm3 vs. 72.49 (51.91, 199.59) mm3, P<0.05) and (13.76% (8.81%, 27.64%) vs. 16.04% (11.18%, 27.05%), P<0.05) respectively. Both parameters further decreased to (55.63 (27.18, 179.40) mm3) and (12.71% (8.39%, 24.41%)) at 24 months (both P<0.05). Wall volume, lumen volume and percent wall volume (PWV) were not affected post therapy in both two groups(P>0.05). There were no correlations between the changes of plaque parameters including volume and percentage of LRNC, wall volume, lumen volume, PWV and the changes of blood lipid parameters (TC, LDL-C, HDL-C and TG) in 3 and 24 months (P>0.05). Conclusion: Lipid-lowering therapy possesses different effects on carotid atherosclerotic plaque in diabetic and non-diabetic patients, and the LRNC improvement is more significant in non-diabetic patients as compared to diabetic patients.
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Doenças das Artérias Carótidas , Placa Aterosclerótica , Rosuvastatina Cálcica , Artérias Carótidas/diagnóstico por imagem , Artérias Carótidas/patologia , Doenças das Artérias Carótidas/diagnóstico por imagem , Doenças das Artérias Carótidas/tratamento farmacológico , HDL-Colesterol/uso terapêutico , LDL-Colesterol , Diabetes Mellitus , Humanos , Imageamento por Ressonância Magnética/métodos , Necrose/patologia , Placa Aterosclerótica/diagnóstico por imagem , Placa Aterosclerótica/tratamento farmacológico , Estudos Retrospectivos , Rosuvastatina Cálcica/uso terapêuticoRESUMO
Objective: To investigate the characteristics of pregnancy with pre-excitation syndrome and its influence on pregnancy outcomes. Methods: A retrospective analysis was made on the clinical data of 62 cases of pregnancy complicated with pre-excitation syndrome in Beijing Anzhen Hospital from Jan. 2008 to Dec. 2008. According to whether there was a supraventricular tachycardia (SVT) in pregnancy, they were divided into two groups. There were 16 pregnant women in the SVT seizure group during pregnancy, and 46 pregnant women in no SVT seizure group, with a multi-disciplinary comprehensive diagnosis and treatment model. SPSS software was used to analyze the data and compare the gestational age, age and weight of the newborn, and then compare the pregnancy outcomes. Results: (1) The total number of deliveries in Beijing Anzhen Hospital during the study period was 21 786, and the patients with pregnancy combined with pre-excitation syndrome account for 0.28% (62/21 786). (2) Totally 44 patients (71%, 44/62) were diagnosed with pre-excitation syndrome before pregnancy, and 18 patients (29%, 18/62) were diagnosed for the first-time during pregnancy. Among patients diagnosed with pre-excitation syndrome before pregnancy, 16 patients (36%, 16/44) had seizures before pregnancy, 28 patients (64%, 28/44) had asymptomatic before pregnancy, and 4 of asymptomatic patients had SVT during pregnancy. (3) Of the 16 pregnant women in the SVT seizure group during pregnancy, 2 patients (2/16) had SVT episodes in the first trimester, 5 patients (5/16) had SVT episodes in the second trimester, 9 patients (9/16) had SVT episodes in the third trimester. In the SVT seizure group, 8 patients (8/16) had SVT episodes before pregnancy, and 8 patients (8/16) had no SVT episodes before pregnancy. There were 46 patients in the SVT seizure-free group during pregnancy, including 9 patients with SVT attacks before pregnancy and 37 patients without SVT before pregnancy. (4) Compared with the pregnant women in the SVT seizure group, the age, weight gained during pregnancy, delivery gestation week, newborn weight, and the time of the first and second labors were not statistically different between the two groups of pregnant women (all P>0.05). However, the total duration of labor in the SVT seizure group during pregnancy was shorter and pre-pregnancy weight was lower (all P<0.05). The rate of cesarean section in pregnant women with SVT attack was 12/16, and the rate of cesarean section in pregnant women without SVT was 50% (23/46; P=0.051). No pregnant woman had an arrhythmia during delivery. Conclusions: SVT episode in patients during pregnancy most occurs in the third trimester. Patients who are asymptomatic before pregnancy may also have SVT during pregnancy. Pre-excitation syndrome patients with SVT attacks during pregnancy increase adverse pregnancy outcomes. Multidisciplinary comprehensive management could effectively control pregnant women with pre-excitation syndrome, effectively reduce the occurrence of serious arrhythmia risk events during pregnancy, so that most patients could get good pregnancy outcomes.
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Cesárea/estatística & dados numéricos , Síndromes de Pré-Excitação/diagnóstico , Resultado da Gravidez , China/epidemiologia , Feminino , Idade Gestacional , Humanos , Recém-Nascido , Gravidez , Complicações na Gravidez/epidemiologia , Estudos RetrospectivosRESUMO
One of the end-products of ROS-induced peroxidation, malondialdehyde (MDA), induces the cross-links in proteins, which leads to perturbation of the physiological functions of cells and contributes to abnormal biological regulation and various disorders. Taurine (2-aminoethanesulfonic acid, Tau) aids in adjusting normal physiological functions to confer stress resistance. The protective effects of Tau against MDA stress in vitro or in vivo were reported previously. In this study, we had investigated the protective effects of taurine on viability, oxidative stress levels and mitochondrial biogenesis in mouse muscle C2C12 cells undergoing MDA induced stress. We show that the treatment with 100 µM MDA leads to increase in cell oxidative stress levels, inhibition of mitochondrial biogenesis and the reduction of the cell survival rates. The pretreatment with 0.1 µM taurine reduced MDA-induced death rate via inhibition of oxidative stress, restoration of mitochondrial functions of the mitochondrial membrane potential (MMP) and ATP production. In MDA stress, the pre-treatment with 0.1 µM taurine leads to upregulation of the factors of mitochondrial biogenesis. These observations suggest that the cytoprotective effects of taurine may be due to an induction of mitochondrial biogenesis.
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Malondialdeído/toxicidade , Mitocôndrias/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Taurina/farmacologia , Trifosfato de Adenosina/biossíntese , Animais , Sobrevivência Celular/efeitos dos fármacos , Humanos , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Camundongos , Mitocôndrias/metabolismo , Células Musculares/efeitos dos fármacos , Biogênese de OrganelasRESUMO
Bats are considered as the reservoirs of several emerging infectious disease, and novel viruses are continually found in bats all around the world. Studies conducted in southern China found that bats carried a variety of viruses. However, few studies have been conducted on bats in northern China, which harbours a diversity of endemic insectivorous bats. It is important to understand the prevalence and diversity of viruses circulating in bats in northern China. In this study, a total of 145 insectivorous bats representing six species were collected from northern China and screened with degenerate primers for viruses belonging to six families, including coronaviruses, astroviruses, hantaviruses, paramyxoviruses, adenoviruses and circoviruses. Our study found that four of the viruses screened for were positive and the overall detection rates for astroviruses, coronaviruses, adenoviruses and circoviruses in bats were 21.4%, 15.9%, 20% and 37.2%, respectively. In addition, we found that bats in northern China harboured a diversity of novel viruses. Common Serotine (Eptesicus serotinu), Fringed long-footed Myotis (Myotis fimriatus) and Peking Myotis (Myotis pequinius) were investigated in China for the first time. Our study provided new information on the ecology and phylogeny of bat-borne viruses.
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Quirópteros/virologia , Vírus/isolamento & purificação , Adenoviridae/genética , Adenoviridae/isolamento & purificação , Animais , Astroviridae/genética , Astroviridae/isolamento & purificação , China/epidemiologia , Circoviridae/genética , Circoviridae/isolamento & purificação , Coronaviridae/genética , Coronaviridae/isolamento & purificação , Filogenia , Vírus/classificação , Vírus/genéticaRESUMO
OBJECTIVE: The aim of this study was to explore the impact of normoxic and hypoxic cell-culture conditions on the expression and secretion of adipose mesenchymal stem cells (ADMSCs)-derived paracrine molecules, and to evaluate the cardioprotective role of hypoxic condition medium (hypoCM) in vivo. MATERIALS AND METHODS: Semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA) analyses of normoxic and hypoxic ADMSCs and their conditioned medium fractions. Then, the effect of hypoCM on cardiomyocytes proliferation and migration was assessed. Moreover, a rat model of myocardial infarct (MI) was established to test the therapeutic effect of hypoCM in vivo. RESULTS: ADMSCs expressed and secreted significantly higher amounts of vascular endothelial growth factor (VEGF), hepatocyte growth factor (HGF) and stromal derived factor-1 (SDF-1 or CXCL12) under hypoxic conditions. Furthermore, compared with the vehicle control, hypoCM significantly enhanced the proliferation and migration of cardiomyocytes. Consistent with the in vitro data, hypoCM decreased the infarct size, apoptosis index and apoptosis related protein in the rat MI model. CONCLUSIONS: These findings suggest that ADMSCs promote rat MI via hypoxia-enhanced paracrine.
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Tecido Adiposo/metabolismo , Meios de Cultivo Condicionados/metabolismo , Células-Tronco Mesenquimais/metabolismo , Infarto do Miocárdio/metabolismo , Infarto do Miocárdio/prevenção & controle , Animais , Apoptose/efeitos dos fármacos , Apoptose/fisiologia , Cardiotônicos/administração & dosagem , Cardiotônicos/metabolismo , Hipóxia Celular/efeitos dos fármacos , Hipóxia Celular/fisiologia , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/fisiologia , Quimiocina CXCL12/metabolismo , Meios de Cultivo Condicionados/farmacologia , Fator de Crescimento de Hepatócito/metabolismo , Humanos , Masculino , Miócitos Cardíacos/metabolismo , Ratos , Ratos WistarRESUMO
OBJECTIVE: This study aims to explore the effects of lentivirus mediated cyclooxygenase-2 gene shorthairpinRNA (COX-2-shRNA) on invasiveness of endometrial carcinoma HEC-1B cells. MATERIALS AND METHODS: Double-stranded DNA oligonucleotide of COX-2-shRNA was designed and synthesized, and the recombinant lentiviral vector COX-2-ShRNA (LV-COX-2-ShRNA) was constructed. LV-COX-2-ShRNA, pHelper 1, and pHelper 2 were transferred into 293T cells, followed by lentiviral packaging. The virus titer was tested according to expression level of GFP in 293T cells. HEC-1B cells were infected with recombinant lentivirus. The silencing of COX-2 gene was assessed by real-time PCR and western-blot, and the in vivo invasiveness of HEC-1B cells was analyzed by transwell invasion assay. RESULTS: Recombinant lentiviral vector expressing siRNA targeting COX-2 gene was successfully constructed to harvest the recombinant lentivirus with the concentrated virus suspension titer of 5 x 10(7)Tu/ml. Compared with control group, the inhibitory rate of COX-2 expression in HEC-1B cells in siRNA group were 61.87% and 67.48% at mRNA and protein level, respectively. The mean number of cells penetrating matrigel was 16.6, which was significantly less than the control group 50.2 and non-specific siRNA infection group 47.2, the invasion inhibition rate being 64.8% (p < 0.01). CONCLUSION: RNA interference can inhibit the invasiveness of HEC-in cells.
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Ciclo-Oxigenase 2/genética , Neoplasias do Endométrio/genética , Neoplasias do Endométrio/patologia , Linhagem Celular Tumoral , Ciclo-Oxigenase 2/metabolismo , Neoplasias do Endométrio/enzimologia , Feminino , Inativação Gênica , Vetores Genéticos , Humanos , Lentivirus , Invasividade Neoplásica/genética , RNA Interferente PequenoRESUMO
In this paper, we present a blind forensic approach for the detection of global image modifications like filtering, lossy compression, scaling and so on. It is based on a new set of image features we proposed, called Histogram statistics of Reorganized Block-based Tchebichef moments (HRBT) features, and which are used as input of a set of classifiers we learned to discriminate tampered images from original ones. In this article, we compare the performances of our features with others proposed schemes from the literature in application to different medical image modalities (MRI, X-Ray ). Experimental results show that our HRBT features perform well and in some cases better than other features.
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Diagnóstico por Imagem , Medicina Legal , HumanosRESUMO
In this paper we present a medical image integrity verification system that not only allows detecting and approximating malevolent local image alterations (e.g. removal or addition of findings) but is also capable to identify the nature of global image processing applied to the image (e.g. lossy compression, filtering ). For that purpose, we propose an image signature derived from the geometric moments of pixel blocks. Such a signature is computed over regions of interest of the image and then watermarked in regions of non interest. Image integrity analysis is conducted by comparing embedded and recomputed signatures. If any, local modifications are approximated through the determination of the parameters of the nearest generalized 2D Gaussian. Image moments are taken as image features and serve as inputs to one classifier we learned to discriminate the type of global image processing. Experimental results with both local and global modifications illustrate the overall performances of our approach.
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Segurança Computacional , Diagnóstico por Imagem/métodos , Medicina Legal/métodos , Processamento de Imagem Assistida por Computador/métodos , Humanos , Imageamento por Ressonância Magnética , Distribuição Normal , Retina/anatomia & histologiaRESUMO
In this paper, we propose a system which aims at verifying integrity of medical images. It not only detects and localizes alterations, but also seeks into the details of the image modification to understand what occurred. For that latter purpose, we developed an image signature which allows our system to approximate modifications by a simple model, a door function of similar dimensions. This signature is partly based on a linear combination of the DCT coefficients of pixel blocks. Protection data is attached to the image by watermarking. Whence, image integrity verification is conducted by comparing this embedded data to the recomputed one from the observed image. Experimental results with malicious image modification illustrate the overall performances of our system.
Assuntos
Algoritmos , Segurança Computacional , Compressão de Dados/métodos , Interpretação de Imagem Assistida por Computador/métodos , Reconhecimento Automatizado de Padrão/métodos , Rotulagem de Produtos/métodos , Processamento de Sinais Assistido por Computador , Aumento da Imagem/métodosRESUMO
OBJECTIVE: To determine whether foreign diagnostic criteria for the diagnosis of gestational diabetes mellitus (GDM) are suitable for Chinese pregnant women. METHODS: The study participants were 340 pregnant women receiving obstetric care at the Shanghai Jiaotong University-Affiliated Sixth People's Hospital in Shanghai, China. The normal-pregnancy group comprised 190 women with no risk factor for GDM and the high-risk pregnancy group comprised 150 women who had at least one high-risk factor for GDM. All women took the diagnostic 100-g, 3-h oral glucose tolerance test (100-g 3-h OGTT) between 24 and 28 weeks of pregnancy. The results of the 100-g 3-h OGTT were classified according to three different sets of diagnostic criteria: (1) new, "Chinese" diagnostic criteria based on the results from the 100-g 3-h OGTT performed in the 190 healthy participating women; (2) the Carpenter and Coustan criteria; and (3) the National Diabetes Data Group (NDDG) criteria. Venous plasma glucose (VPG) was measured by the glucose oxidase method. A consistency check was used for analysis. Obstetric and neonatal outcomes were recorded. RESULTS: With 97.5% as the statistical cutoff value for the 100-g 3-h OGTT, the new diagnostic criteria for this study, based on data obtained from the 100-g 3-h OGTT performed on the 190 participating healthy pregnant women, were 5.2, 10.3, 8.9, and 7.7 mmol/L at 0, 60, 120, and 180 min. The e value was 0.83 for the new criteria vs. the Carpenter and Coustan criteria (P<0.001) and 0.70 for the new criteria vs. the NDDG criteria (P<0.001). In women with GDM and gestational-impaired glucose tolerance (GIGT), the incidence rates of macrosomia by the new criteria and the Carpenter and Coustan criteria were similar, but higher than the rates calculated with the NDDG criteria (P<0.05). CONCLUSION: With venous plasma glucose level measured by the glucose oxidase method, the Carpenter and Coustan criteria are applicable to Chinese pregnant women for diagnosis of GDM.
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Povo Asiático , Diabetes Gestacional/diagnóstico , Diabetes Gestacional/etnologia , Adulto , China , Feminino , Humanos , Gravidez , Resultado da GravidezRESUMO
Iterative reconstruction methods such as the expectation maximization maximum likelihood (EMML) method can be accelerated by using a rescaled block-iterative (RBI) algorithm. It was demonstrated that the space-alternating generalized expectation-maximization (SAGE) algorithm is superior to the EMML due to the following facts: (1) The hidden data spaces can be appropriately chosen and then be used in SAGE algorithm to speed up the convergence rate. (2) SAGE algorithm updates the parameters sequentially which makes its M-step to be treated more easily. In this paper, we present a novel algorithm that combines the RBI algorithm with SAGE algorithm. The convergence property of RBI-SAGE is discussed, and the image quality is assessed with mean absolute error and chi-square error. The experimental results show that the proposed method is more effective than the SAGE algorithm even if the projection data includes statistic noise.
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This work presents a new iterative method for reconstructing positron emission tomography (PET) images. Unlike conventional maximum likelihood-expectation maximization (MLEM), this method intends to introduce the fuzzy set principle to MLEM algorithm. In this work, the noncognitive uncertainty of the observed projection data are described by their probability density function; whereas the cognitive uncertainty of a random variable can be described by the membership function for its fuzziness. The mean of the observed projection data are regard as fuzzy random variables because of the complexity of system. The fuzzy random variable can be represented by a triangular membership function. We establish a joint probability density function that includes the effects of both fuzziness and randomness. The maximum likelihood approach is used to estimate the image vector. The order subset (OS), rescaled block-iterative (RBI), and row-action (RA) techniques are applied to our PET reconstructed method to speed up the convergence rate and to decrease the iteration numbers.
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The purpose of this paper is to develop a new method for automated on-line verification of the treatment field shape during radiotherapy. The treatment field boundary is extracted from the digital portal image and is then approximated by a polygon. The proposed procedure used one of the approved field shapes as the reference boundary for automated comparison with subsequent portal field boundaries. The orthogonal moment-based method was applied to align treatment field boundaries that include the translational shifts, scaling factor and rotation angle. Firstly, the moments of order up to one were used to adjust the magnification and translation of the test field boundary related to the reference one; this step created a common coordinate system for the two images. Then a quadratic least-square objective function based on the orthogonal moments (e.g. Legendre moments) of the two field shapes was employed to perform rotational correction. Since moment computation by a straightforward method required a large number of multiplication and addition operations, a fast method for computing Legendre moments was also developed to decrease the calculation time. Application of the method to some simulated cases showed that our alignment procedure has an accuracy of 0.5 mm in detecting translational shift, 0.004 in detecting magnification and less than 0.3 degrees in detecting rotation angle between the test shape and the reference shape. The alignment procedure using the proposed method can be done within 2 s on a Pentium II personal computer. Therefore, our method is potentially useful for automated real-time treatment field shape verification.
Assuntos
Radiometria/métodos , Planejamento da Radioterapia Assistida por Computador/métodos , Algoritmos , Simulação por Computador , Modelos Teóricos , Gravação em VídeoRESUMO
A recently developed soil leaching column chromatography was applied to study the adsorption of pesticide in water-soil system. Soil was filled directly into a liquid chromatographic column and pesticide solution was applied as an eluant, and the adsorption equilibrium was monitored by a UV detector. The herbicide atrazine, i. e. 2-chloro-4-ethylamino-6-isopropylamino-s-triazine, was chosen as an example. Its mass concentration ranged from 19.73 mg/L to 29.60 g/L. After the soil phase was rinsed with methanol, the amount of atrazine adsorbed was calculated from the difference between the atrazine totally rinsed and that in solution in the column. The low content atrazine sample was determined by enrichment on an ODS column and step-gradient method. It shows that the adsorption of atrazine on a sandy loam soil is in accordance with Freundlich isotherm. The adsorption coefficient Kf is 842.6 mL/kg and the normalized organic carbon adsorption coefficient log Koc is 1.832.
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Atrazina/análise , Cromatografia Líquida , Herbicidas/análise , Poluentes do Solo/análise , Poluentes da Água/análise , Adsorção , Resíduos de Praguicidas/análise , Solo/análiseRESUMO
The gamma unit is used to irradiate a target within the brain. During such a treatment many parameters, including the number of shots, the coordinates, the collimator size and the weight associated with each shot, affect the amount of dose delivered to the target volume and to the surrounding normal tissues. Hence it is not easy to determine an appropriate set of these parameters by a trial and error method. For this reason, we present here an optimization method to determine mathematically those parameters. This method is composed of two steps: firstly, a quasi-Newton method is used to deal with the continuous variables such as position and weight of shots; the result obtained at the end of this step then serves as the initial configuration for the next step, in which a simulated annealing method is applied to optimize all the aforementioned parameters. Application of the proposed methods to two examples shows that our optimization algorithm runs in a satisfactory way.
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Raios gama , Radioterapia/métodos , Algoritmos , Neoplasias Encefálicas/radioterapia , Radiometria , Radiocirurgia/métodos , Técnicas EstereotáxicasRESUMO
This paper presents a three-dimensional edge operator aimed at the detection of anatomical structures in medical imaging. It uses the spatial moments of gray level surface, and operates in three dimensions with any window size. It allows us to estimate the location and the contrast surface, as well as the surface orientation. The computation of the discrete version is reported. Bias and errors due to the spatial sampling and noise are analyzed both at a theoretical and experimental level. The moment-based operator is compared with other well-known edge operators on simple shaped primitives for which the analytical solution is known. The 3D rendering of real data is then provided by merging the operator in a ray-tracing framework.
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Interpretação de Imagem Assistida por Computador/métodos , Processamento de Imagem Assistida por Computador/métodos , Artefatos , Humanos , Processamento de Imagem Assistida por Computador/estatística & dados numéricos , Matemática , Variações Dependentes do ObservadorRESUMO
This paper describes a new method for the three-dimensional (3-D) tracking and the quantification of blood vessels from magnetic resonance angiography (MRA). The approach is based on 3-D geometrical moments and consists of the following steps: (1) interactive selection of 3-D seed points; (2) automatic tracking of the vessels; (3) local computation of both diameter and orientation; (4) rendering of the vessels. This detection and estimation scheme has been validated on simulated and real data.