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1.
Chaos Solitons Fractals ; 117: 168-174, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32288355

RESUMO

We consider the fractional order epidemic model based on assumption that people will recover after disease and may be infected again on a time interval of non fatal disease. Our mathematical formulation is based on the fractional Caputo derivative. The existence and uniqueness of the solution is discussed. Furthermore, numerical solution is studied by variational iteration method and Euler method. Consequently, some numerical results are presented within.

2.
J Water Health ; 15(1): 133-144, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28151446

RESUMO

This work evaluated the antimicrobial efficacy of kaolin clay and its loaded forms with carbon nanotubes (CNTs) and silver nanoparticles (AgNPs) against bacterial isolates from different water supplies (tap, underground and surface water) in addition to wastewater. A total of 160 water samples were collected from different water sources in the investigated districts. Samples were cultured for isolation and serological identification of pathogenic bacteria. AgNPs were synthesized by a typical one-step synthesis protocol, where CNTs were carried out in a reactor employing the double bias-assisted hot filament chemical vapor deposition method. Both were characterized using transmission electron microscopy, infrared and X-ray fluorescence (XRF) spectroscopy. The antimicrobial efficacy of each of natural kaolin clay, AgNPs- and CNTs-loaded clays were evaluated by their application in four concentrations (0.01, 0.03, 0.05 and 0.1 ppm) at different contact times (5 min, 15 min, 30 min and 2 h). AgNPs-loaded clays at concentrations of 0.05 and 0.1 mg/l for 2 h contact time exhibited a higher bactericidal efficacy on Escherichia coli and Salmonella spp. (70, 70, 80 and 90%, respectively) compared to CNTs-loaded clay. Concluding, the application of AgNPs-loaded clay for removal of water bacterial contaminants at a concentration of 0.1 ppm for 2 h contact times resulted in highly effective removals.


Assuntos
Bactérias/isolamento & purificação , Caulim/química , Nanopartículas Metálicas/química , Nanotubos de Carbono/química , Eliminação de Resíduos Líquidos/métodos , Microbiologia da Água , Purificação da Água/métodos , Adsorção , Água Potável/microbiologia , Prata/química , Eliminação de Resíduos Líquidos/instrumentação , Águas Residuárias/microbiologia , Purificação da Água/instrumentação
3.
Environ Monit Assess ; 188(8): 445, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27372905

RESUMO

Waste management is a successful instrument to minimize generated waste and improve environmental conditions. In spite of the large share of developing countries in the textile industry, limited information is available concerning the waste management strategies implemented for textiles on those countries and their environmental impacts. In the current study, two waste management approaches for hazardous solid waste treatment of acrylic fibers (landfill and incineration) were investigated. The main research questions were: What are the different impacts of each waste management strategy? Which waste management strategy is more ecofriendly? Life cycle assessment was employed in order to model the environmental impacts of each waste streaming approach separately then compare them together. Results revealed that incineration was the more ecofriendly approach. Highest impacts of both approaches were on ecotoxicity and carcinogenic potentials due to release of metals from pigment wastes. Landfill had an impact of 46.8 % on human health as compared to 28 % by incineration. Incineration impact on ecosystem quality was higher than landfill impact (68.4 and 51.3 %, respectively). As for resources category, incineration had a higher impact than landfill (3.5 and 2.0 %, respectively). Those impacts could be mitigated if state-of-the-art landfill or incinerator were used and could be reduced by applying waste to energy approaches for both management systems In conclusion, shifting waste treatment from landfill to incineration would decrease the overall environmental impacts and allow energy recovery. The potential of waste to energy approach by incineration with heat recovery could be considered in further studies. Future research is needed in order to assess the implementation of waste management systems and the preferable waste management strategies in the textile industry on developing countries.


Assuntos
Conservação dos Recursos Naturais/métodos , Monitoramento Ambiental/métodos , Resíduos Perigosos/análise , Incineração/métodos , Indústria Têxtil , Gerenciamento de Resíduos/métodos , Egito , Humanos , Instalações de Eliminação de Resíduos
4.
Urol Case Rep ; 4: 61-3, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26793585

RESUMO

This is to describe a case of a morbidly obese (BMI = 40) female with retrocaval ureter treated with laparoendoscopic single-site surgery. A JJ stent was positioned. A 2 cm umbilical access was created. A single port platform was positioned. The entire ureter was mobilized posterior to the vena cava and transected where the dilated portion ended. The distal ureter was repositioned lateral to the inferior vena cava. Anastomosis was done. A 3 mm trocar was used to assist suturing. At 4-month follow-up, CT revealed no evidence of obstruction of the right kidney and the patient was symptomless. Although challenging, in a morbidly obese patient, LESS repair for retrocaval ureter is feasible.

5.
J Environ Manage ; 166: 1-11, 2016 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-26468602

RESUMO

Concerns over the negative environmental impact from livestock farming across Europe continue to make their mark resulting in new legislation and large research programs. However, despite a huge amount of published material and many available techniques, doubts over the success of national and European initiatives remain. Uptake of the more cost-effective and environmentally-friendly farming methods (such as dietary control, building design and good manure management) is already widespread but unlikely to be enough in itself to ensure that current environmental targets are fully met. Some of the abatement options available for intensive pig and poultry farming are brought together under the European IPPC/IED directive where they are listed as Best Available Techniques (BAT). This list is far from complete and other methods including many treatment options are currently excluded. However, the efficacies of many of the current BAT-listed options are modest, difficult to regulate and in some cases they may even be counterproductive with respect to other objectives ie pollution swapping. Evaluation of the existing and new BAT technologies is a key to a successful abatement of pollution from the sector and this in turn relies heavily on good measurement strategies. Consideration of the global effect of proposed techniques in the context of the whole farm will be essential for the development of a valid strategy.


Assuntos
Criação de Animais Domésticos/métodos , Poluição Ambiental , Gado/crescimento & desenvolvimento , Criação de Animais Domésticos/legislação & jurisprudência , Criação de Animais Domésticos/tendências , Animais , Poluição Ambiental/análise , Poluição Ambiental/legislação & jurisprudência , Europa (Continente) , Regulamentação Governamental
6.
Animal ; 10(2): 212-20, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26412234

RESUMO

Generally, <30% of dairy cattle's nitrogen intake is retained in milk. Large amounts of nitrogen are excreted in manure, especially in urine, with damaging impacts on the environment. This study explores the effect of lowering dietary degradable nitrogen supplies--while maintaining metabolisable protein--on dairy cows' performance, nitrogen use efficiency and gas emissions (NH3, N2O, CH4) at barn level with tied animals. Two dietary N concentrations (CP: 12% DM for LowN; 18% DM for HighN) were offered to two groups of three lactating dairy cows in a split-plot design over four periods of 2 weeks. Diets were formulated to provide similar metabolisable protein supply, with degradable N either in deficit or in excess (PDIN of 84 and 114 g/kg DM for LowN and HighN, respectively). Cows ingested 0.8 kg DM/day less on the LowN diet, which was also 2.5% less digestible. Milk yield and composition were not significantly affected. N exported in milk was 5% lower (LowN: 129 g N/day; HighN: 136 g N/day; P<0.001) but milk protein yield was not significantly affected (LowN: 801 g/day; HighN: 823 g/day; P=0.10). Cows logically ingested less nitrogen on the LowN diet (LowN: 415 g N/day; HighN: 626 g N/day; P<0.001) resulting in a higher N use efficiency (N milk/N intake; LowN: 0.31; HighN: 0.22; P<0.001). N excreted in urine was almost four times lower on the LowN diet (LowN: 65 g N/day; HighN: 243 g N/day; P<0.001) while urinary urea N concentration was eightfold lower (LowN: 4.6 g/l; HighN: 22.9 g/l; P<0.001). Ammonia emission (expressed in g/h in order to remove periods of the day with potential interferences with volatile molecules from feed) was also lower on the LowN diet (LowN: 1.03 g/h per cow; HighN: 1.25 g/h per cow; P<0.05). Greenhouse gas emissions (N2O and CH4) at barn level were not significantly affected by the amount of dietary N. Offering low amounts of degradable protein with suitable metabolisable protein amounts to cattle improved nitrogen use efficiency and lowered ammonia emissions at barn level. This strategy would, however, need to be validated for longer periods, other housing systems (free stall barns) and at farm level including all stages of manure management.


Assuntos
Bovinos/fisiologia , Proteínas Alimentares/administração & dosagem , Meio Ambiente , Lactação/fisiologia , Nitrogênio/metabolismo , Amônia/análise , Animais , Dieta com Restrição de Proteínas , Proteínas Alimentares/provisão & distribuição , Ingestão de Alimentos , Feminino , Abrigo para Animais/classificação , Esterco , Metano/análise , Leite/química , Leite/metabolismo , Proteínas do Leite/análise , Óxido Nítrico/análise , Nitrogênio/administração & dosagem , Ureia
7.
Bioprocess Biosyst Eng ; 38(9): 1819-33, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26059818

RESUMO

Inorganic nitrogen supplementation is commonly used to boost fermentation metabolism in yeast cultures. However, an excessive addition can induce an opposite effect. Hence, it is important to ensure that the ammonia supplemented to the culture leads to an improvement of the ethanol production while avoiding undesirable inhibition effects. To this end, a macroscopic model describing the influence of ammonia addition on Saccharomyces cerevisiae metabolism during bioethanol production from potato peel wastes has been developed. The model parameters are obtained by a simplified identification methodology in five steps. It is validated with experimental data and successfully predicts the dynamics of growth, substrate consumption (ammonia and fermentable sugar sources) and bioethanol production, even in cross validation. The model is used to determine the optimal quantity of supplemented ammonia required for maximizing bioethanol production from potato peel wastes in batch cultures.


Assuntos
Metabolismo dos Carboidratos/fisiologia , Etanol/metabolismo , Modelos Biológicos , Nitrogênio/metabolismo , Saccharomyces cerevisiae/fisiologia , Solanum tuberosum/microbiologia , Amônia/metabolismo , Reatores Biológicos/microbiologia , Proliferação de Células/fisiologia , Simulação por Computador , Etanol/isolamento & purificação , Resíduos Industriais/prevenção & controle , Compostos Inorgânicos/metabolismo , Eliminação de Resíduos/métodos
8.
Afr. j. urol. (Online) ; 17(1): 1-5, 2011.
Artigo em Inglês | AIM (África) | ID: biblio-1258100

RESUMO

Objectives: Anterior vaginal wall slings (AVWS) have been used for decades in the treatment of female stress urinary incontinence (SUI). The main drawback of using the vaginal wall as a sling is its tendency to weaken and stretch over the course of years. The use of synthetic tapes for the treatment of SUI is effective but costly. For patients who cannot afford synthetic tapes; we describe the preliminary results of a modified AVWS technique for the treatment of SUI types II and III. Patients and Methods: In this series; a modification of the AVWS was applied in 35 female patients with SUI. A fortified and rolled flap is used to provide compression and support of the urethra. The vaginal mucosal surface of the flap is cauterized and two diagonal sutures are placed across it. The flap is then rolled on itself with a running 2/0 vicryl suture. Two sutures attached to both ends are passed retropubically to the anterior abdominal wall and tied over the rectus sheath. Results: All 35 female patients had type II/III SUI. After a median follow up of 43 months; 91of the patients were dry or used 0-1 pad per day. Only one patient suffered from transient retention for one week post-operatively. Conclusion: This is a simple method to reinforce vaginal wall flaps. It could offer a durable and effective option for the treatment of SUI in patients who can not afford synthetic tapes. Long-term follow up is required to evaluate the durability of the procedure


Assuntos
Estresse Fisiológico/terapia , Slings Suburetrais , Incontinência Urinária
9.
Afr. j. urol. (Online) ; 17(2): 43-47, 2011.
Artigo em Inglês | AIM (África) | ID: biblio-1258107

RESUMO

Objectives: Urinary incontinence in patients with neurological disease is a major health problem. A modified rectus fascial sling has been assessed in incontinent male patients. Patients and Methods: Fourteen adult male patients with total incontinence due to neurogenic or post-traumatic and etiology were included in this study. A rectangular rectus sheath flap was harvested and defatted.The flap was placed around the bulbar urethra and sutures were passed both in front of and behindthe pubic bone. Both sutures on each side were tied to each other over the pubic bone. Results: Of the 14 patients; 9 (64.3) were completely dry; 3 (21.4) reported improved continence; while 2 (14.3) were a failure. In total; 71.4of the patients showed significant improvement using the Incontinence Quality of Life (IQoL) questionnaire. A significant decrease in the number of pads used per day of 61.3(p


Assuntos
Masculino , Incontinência Urinária/terapia
10.
East Mediterr Health J ; 16(11): 1170-82, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21218742

RESUMO

The objective of this descriptive, hospital-based comparative cross-sectional survey was to determine gender differences in factors associated with patients' decisions to seek treatment for urinary incontinence (Ul). Using an interview questionnaire, data were collected from 353 patients attending clinics at hospitals in Alexandria, Egypt. There were differences between males and females regarding specific psychosocial factors motivating health care seeking behaviour. Women had fewer hospital admissions and hospital days and less use of diagnostic procedures and surgery. More women suffered from at least one negative impact on their social lives compared to men. The impact of symptoms on quality of life appeared to be the main trigger for seeking help for UI in both men and women.


Assuntos
Tomada de Decisões , Homens/psicologia , Aceitação pelo Paciente de Cuidados de Saúde/psicologia , Incontinência Urinária/psicologia , Mulheres/psicologia , Adolescente , Adulto , Idoso , Distribuição de Qui-Quadrado , Efeitos Psicossociais da Doença , Estudos Transversais , Egito/epidemiologia , Feminino , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Aceitação pelo Paciente de Cuidados de Saúde/estatística & dados numéricos , Qualidade de Vida/psicologia , Fatores Sexuais , Comportamento Social , Estatísticas não Paramétricas , Inquéritos e Questionários , Incontinência Urinária/epidemiologia , Incontinência Urinária/terapia
11.
Animal ; 4(8): 1413-24, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22444661

RESUMO

A model has been developed to predict pig manure evolution (mass, dry and organic matter, N, P, K, Cu and Zn contents) and related gaseous emissions (methane (CH4), nitrous oxide (N2O) and ammonia (NH3)) from pig excreta up to manure stored before spreading. This model forms part of a more comprehensive model including the prediction of pig excretion. The model simulates contrasted management systems, including different options for housing (slatted floor or deep litter), outside storage of manure and treatment (anaerobic digestion, biological N removal processes, slurry composting (SC) with straw and solid manure composting). Farmer practices and climatic conditions, which have significant effects on gaseous emissions within each option, have also been identified. The quantification of their effects was based on expert judgement from literature and local experiments, relations from mechanistic models or simple emission factors, depending on existing knowledge. The model helps to identify relative advantages and weaknesses for each system. For example, deep-litter with standard management practices is associated with high-greenhouse gas (GHG) production (+125% compared to slatted floor) and SC on straw is associated with high NH3 emission (+15% compared to slatted floor). Another important result from model building and first simulations is that farmer practices and the climate induce an intra-system (for a given infrastructure) variability of NH3 and GHG emissions nearly as high as inter-system variability. For example, in deep-litter housing systems, NH3 and N2O emissions from animal housing may vary between 6% and 53%, and between 1% and 19% of total N excreted, respectively. Thus, the model could be useful to identify and quantify improvement margins on farms, more precisely or more easily than current methodologies.

12.
(East. Mediterr. health j).
em Inglês | WHO IRIS | ID: who-118049

RESUMO

The objective of this descriptive, hospital-based comparative cross-sectional survey was to determine gender differences in factors associated with patients' decisions to seek treatment for urinary incontinence [Ul]. Using an interview questionnaire, data were collected from 353 patients attending clinics at hospitals in Alexandria, Egypt. There were differences between males and females regarding specific psychosocial factors motivating health care seeking behaviour. Women had fewer hospital admissions and hospital days and less use of diagnostic procedures and surgery. More women suffered from at least one negative impact on their social lives compared to men. The impact of symptoms on quality of life appeared to be the main trigger for seeking help for Ul in both men and women


Assuntos
Fatores Sexuais , Tomada de Decisões , Inquéritos e Questionários , Estudos Transversais , Percepção , Estilo de Vida , Qualidade de Vida , Incontinência Urinária
13.
IEEE Trans Pattern Anal Mach Intell ; 31(12): 2257-74, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19834145

RESUMO

Representing a 3D shape by a set of 1D curves that are locally symmetric with respect to its boundary (i.e., curve skeletons) is of importance in several machine intelligence tasks. This paper presents a fast, automatic, and robust variational framework for computing continuous, subvoxel accurate curve skeletons from volumetric objects. A reference point inside the object is considered a point source that transmits two wave fronts of different energies. The first front (beta-front) converts the object into a graph, from which the object salient topological nodes are determined. Curve skeletons are tracked from these nodes along the cost field constructed by the second front (alpha-front) until the point source is reached. The accuracy and robustness of the proposed work are validated against competing techniques as well as a database of 3D objects. Unlike other state-of-the-art techniques, the proposed framework is highly robust because it avoids locating and classifying skeletal junction nodes, employs a new energy that does not form medial surfaces, and finally extracts curve skeletons that correspond to the most prominent parts of the shape and hence are less sensitive to noise.


Assuntos
Osso e Ossos/anatomia & histologia , Imageamento Tridimensional , Modelos Anatômicos , Animais , Inteligência Artificial , Gráficos por Computador , Simulação por Computador , Humanos , Reconhecimento Automatizado de Padrão
14.
Animal ; 3(4): 606-16, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22444385

RESUMO

A total of 200 crossbred pigs (castrated males and females) were used in five replicates to evaluate the influence of rearing conditions for fattening pigs on growth performance, manure production and gaseous emissions. Approximately at 36 kg body weight (BW), littermates were allocated to either a conventional (fully slatted floor, 0.65 m2/pig, considered as control, CON) or an alternative (sawdust bedding, 1.3 m2/pig, with free access to an outdoor area 1.1 m2/pig, OUT) system, until slaughter at approximately 115 kg BW. Pigs had free access to standard growing and finishing diets. Manure was stored as slurry below the slatted floor in the CON system and as litter, for the inside area, or slurry and liquid, for the outside area, in the OUT system. The amount and composition of manure were determined at the end of each replicate. Ammonia emission from the rooms was measured continuously. Dust and odour concentrations were measured in replicates 1 and 2, and CH4, N2O and CO2 emissions were measured in replicate 3. Compared with the CON, the OUT pigs exhibited a faster growth rate (+8%, P < 0.001) due to their greater feed intake (+0.21 kg/day, P < 0.01), resulting in a heavier BW (+7.3 kg, P < 0.001) and a lower lean meat content (-1.6% points, P < 0.001) at slaughter. The total amount of manure produced per pig was similar in both systems (380 kg/pig), but because of the contribution of sawdust, dry matter (DM) content was higher (P < 0.001) and concentrations in N, P, K, Cu and Zn in DM were lower (P < 0.001) in manure from the OUT than from the CON system. In the OUT system, most of the manure DM (70%) was collected indoor, corresponding mostly to the contribution of the sawdust, and most of the manure water (70%) was collected outdoor. Pigs excreted indoor about 60% and 40% of urine and faeces, respectively. Ammonia emission from the room was lower for the OUT system, whereas total NH3 emissions, including the outdoor area, tended to be higher (12.0 and 14.1 g/day N-NH3 per pig for CON and OUT, respectively). Nitrous oxide emission was higher (1.6 and 4.6 g/day N-N2O per pig for CON and OUT, respectively) and methane emission was lower (12.1 and 5.9 g/day per pig for CON and OUT, respectively), for the OUT compared with the CON system.

15.
Talanta ; 75(5): 1175-83, 2008 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-18585199

RESUMO

Ipratropium (IP(+)) ion-selective electrode (ISE) has been constructed from poly(vinyl chloride) matrix membrane containing Ipratropium-tetraphenylborate (IP-TPB) as the electroactive component using 2-nitrophenyloctylether as plasticizer. The electrode exhibits near Nernstian response to Ipratropium bromide (IPBr) over the concentration range 10(-5) to 10(-2) mol L(-1) and detection limit 5.1x10(-6) mol L(-1). The electrode offers significant advantages including long lifetime (>2 months), excellent stability and reproducibility, fast response time (<10 s), wide pH working range (pH 2-9), high thermal stability (isothermal coefficient 0.37 mV/degrees C) and superior selectivity for IPBr over a large number of inorganic and organic substances. The electrode was successfully used as indicator electrode in the potentiometric titration of IPBr versus sodium tetraphenylborate (NaTPB) and in the determination of IPBr in Atrovent vials and spiked urine samples applying batch and flow injection techniques, with satisfactory results.


Assuntos
Broncodilatadores/análise , Análise de Injeção de Fluxo/métodos , Ipratrópio/análise , Preparações Farmacêuticas/análise , Cloreto de Polivinila/química , Broncodilatadores/química , Eletrodos , Ipratrópio/química , Preparações Farmacêuticas/química , Potenciometria , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
16.
IEEE Trans Pattern Anal Mach Intell ; 29(9): 1563-74, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17627044

RESUMO

A wide range of computer vision applications require an accurate solution of a particular Hamilton- Jacobi (HJ) equation, known as the Eikonal equation. In this paper, we propose an improved version of the fast marching method (FMM) that is highly accurate for both 2D and 3D Cartesian domains. The new method is called multi-stencils fast marching (MSFM), which computes the solution at each grid point by solving the Eikonal equation along several stencils and then picks the solution that satisfies the upwind condition. The stencils are centered at each grid point and cover its entire nearest neighbors. In 2D space, 2 stencils cover the 8-neighbors of the point, while in 3D space, 6 stencils cover its 26-neighbors. For those stencils that are not aligned with the natural coordinate system, the Eikonal equation is derived using directional derivatives and then solved using higher order finite difference schemes. The accuracy of the proposed method over the state-of-the-art FMM-based techniques has been demonstrated through comprehensive numerical experiments.


Assuntos
Algoritmos , Inteligência Artificial , Aumento da Imagem/métodos , Interpretação de Imagem Assistida por Computador/métodos , Armazenamento e Recuperação da Informação/métodos , Reconhecimento Automatizado de Padrão/métodos , Análise Numérica Assistida por Computador , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
17.
Med Image Anal ; 10(1): 2-18, 2006 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-15893953

RESUMO

In this paper, we present an automatic statistical approach for extracting 3D blood vessels from time-of-flight (TOF) magnetic resonance angiography (MRA) data. The voxels of the dataset are classified as either blood vessels or background noise. The observed volume data is modeled by two stochastic processes. The low level process characterizes the intensity distribution of the data, while the high level process characterizes their statistical dependence among neighboring voxels. The low level process of the background signal is modeled by a finite mixture of one Rayleigh and two normal distributions, while the blood vessels are modeled by one normal distribution. The parameters of the low level process are estimated using the expectation maximization (EM) algorithm. Since the convergence of the EM is sensitive to the initial estimate of the model parameters, an automatic method for parameter initialization, based on histogram analysis, is provided. To improve the quality of segmentation achieved by the proposed low level model especially in the regions of significantly vascular signal loss, the high level process is modeled as a Markov random field (MRF). Since MRF is sensitive to edges and the intracranial vessels represent roughly 5% of the intracranial volume, 2D MRF will destroy most of the small and medium sized vessels. Therefore, to reduce this limitation, we employed 3D MRF, whose parameters are estimated using the maximum pseudo likelihood estimator (MPLE), which converges to the true likelihood under large lattice. Our proposed model exhibits a good fit to the clinical data and is extensively tested on different synthetic vessel phantoms and several 2D/3D TOF datasets acquired from two different MRI scanners. Experimental results showed that the proposed model provides good quality of segmentation and is capable of delineating vessels down to 3 voxel diameters.


Assuntos
Encéfalo/irrigação sanguínea , Processamento de Imagem Assistida por Computador , Imageamento Tridimensional , Angiografia por Ressonância Magnética , Modelos Estatísticos , Algoritmos , Angiografia Cerebral , Humanos , Imagens de Fantasmas , Processamento de Sinais Assistido por Computador , Processos Estocásticos
18.
Artigo em Inglês | MEDLINE | ID: mdl-17354913

RESUMO

In this paper, we propose a new visualization technique for virtual colonoscopy (VC). The proposed method is called Virtual Fly-Over, which splits the entire colon anatomy into exactly two halves. Then, it assigns a virtual camera to each half to perform fly-over navigation, which has several advantages over both traditional fly-through and related methods. First, by controlling the elevation of the camera, there is no restriction on its field of view (FOV) angle (e.g., >90 degrees) to maximize visualized surface areas, and hence no perspective distortion. Second, the camera viewing volume is perpendicular to each colon half, so potential polyps that are hidden behind haustral folds are easily found. Finally, because the orientation of the splitting surface is controllable, the navigation can be repeated at a different split orientation to overcome the problem of having a polyp that is divided between the two halves of the colon. Quantitative experimental results on 15 clinical datasets have shown that the average surface visibility coverage is 99.59 +/- 0.2%.


Assuntos
Algoritmos , Colonografia Tomográfica Computadorizada/métodos , Gráficos por Computador , Aumento da Imagem/métodos , Interpretação de Imagem Assistida por Computador/métodos , Imageamento Tridimensional/métodos , Interface Usuário-Computador , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
20.
Farmaco ; 60(3): 249-54, 2005 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15784245

RESUMO

Typical anti-mucolytic drugs called salbutamol hydrochloride and bromhexine sulfate encountered in tablets were determined simultaneously either by using linear regression at zero-crossing wavelengths of the first derivation of UV-spectra or by application of multiple linear partial least squares regression method. The results obtained by the two proposed mathematical methods were compared with those obtained by the HPLC technique.


Assuntos
Albuterol/análise , Antitussígenos/análise , Bromoexina/análise , Algoritmos , Cromatografia Líquida de Alta Pressão , Preparações Farmacêuticas/análise , Análise de Regressão , Espectrofotometria Ultravioleta/métodos , Comprimidos/química
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