RESUMO
The aims of this work were to characterize the sorption and evaluate the inhibitory effect of octylphenol ethoxylate Triton X-100 (OPEOTx) on methanogenic and denitrifying sludges. According to Langmuir isotherm, maximums OPEOTx sorption values on methanogenic and denitrifying sludges were 60.70â¯mg (gVSS)-1 and 87.47â¯mg (gVSS)-1 respectively. The specific removal rate of chemical oxygen demand (rCOD) and the accumulated volume biogas (VBG) were used to evaluate the OPEOTx inhibitory effect on sludges. Experimental inhibition data were fitted to the models of non-competitive inhibition and modified Gompertz. Methanogenic sludges reached higher levels inhibition in the rCOD and biogas production potential Pmax (84.0 and 88.5%) comparing with denitrifying sludges (24.3 and 21.9%). Furthermore, in all OPEOTx concentrations, carbohydrates-proteins quotient value of the extracellular polymeric substances for the denitrifying sludges remained below respect to the same quotient in methanogenic sludges. The above contributes in part to explain the greater sorption capacity of the denitrifying sludges by OPEOTx and their granules resistance to be damaged by OPEOTx amphiphilic nature. The study gives insights to understand OPEOs interactions and their effects on methanogenic and denitrifying granular sludges.
Assuntos
Fenóis , Esgotos , Reatores Biológicos , OctoxinolRESUMO
STUDY DESIGN: Retrospective study. OBJECTIVES: To evaluate the demographic and clinical characteristics of patients diagnosed with spinal cord injury (SCI) admitted to a single center. SETTING: Single center study, México. METHODS: This study reviewed 433 patients with SCI. Data were extracted from medical records and retrospectively reviewed. RESULTS: A total of 433 patients with a diagnosis of SCI were included in the analysis. Of these, 346 (79.9%) had traumatic SCI (TSCI) and 87 (20.1%) had non-traumatic SCI (NTSCI). The principal causes of traumatic TSCI were motor vehicle accidents in 150 patients (43.4%), falls in 107 patients (30.9%) and a result of firearms in 58 patients (16.8%). Tumoral cord compression was the main cause of NTSCI in 50 patients (57.4%), followed by degenerative disease-causing myelopathy in 17 patients (19.5%). The proportion of patients affected with NTSCI was significantly lower, 29.9 vs 79.1% (P=0.0001), the age of patients was higher 53.9 vs 37.8 (P<0.002) and SCI was less severe, AIS D 41.33 vs 9.5% (P=0.0001) compared with the TSCI group. CONCLUSIONS: The demographic profiles of patients with TSCI and NTSCI differ in terms of proportion of total SCIs, patient age, male:female ratio and incomplete vs complete injury. The most common etiology of TSCI was motor vehicle accidents (43.4%), and neurological lesions were complete in 62.7% of patients. The most common etiology of NTSCI was tumoral spinal lesions (57.4%), and lesions were incomplete in 75.8% of patients.
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Acidentes por Quedas/estatística & dados numéricos , Demografia , Traumatismos da Medula Espinal/epidemiologia , Traumatismos da Medula Espinal/etiologia , Traumatismos da Medula Espinal/terapia , Acidentes de Trânsito/estatística & dados numéricos , Adolescente , Adulto , Idoso , Criança , Feminino , Humanos , Masculino , México/epidemiologia , Pessoa de Meia-Idade , Estudos Retrospectivos , Traumatismos da Medula Espinal/psicologia , Estatísticas não Paramétricas , Adulto JovemRESUMO
The presence of perianal endometriosis involving the anal sphincter is a rare presentation of this disease, most cases are diagnosed late and few are reported in the literature despite the number of episiotomies performed today. We present a case in a female with perianal symptoms after an episiotomy 15 years ago and visualized by endoanal ultrasound. We also review the literature of this condition. The treatment of choice is wide excision of the lesion involving the anal sphincter so the sphincter defect should be repaired by sphincteroplasty. According to the literature, early diagnosis by clinical suspicion and confirmation by endoanal ultrasound, with wide excision of endometrioma gives satisfactory results regarding anal continence.
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Canal Anal/patologia , Doenças do Ânus/patologia , Endometriose/patologia , Adulto , Canal Anal/diagnóstico por imagem , Canal Anal/cirurgia , Doenças do Ânus/diagnóstico por imagem , Doenças do Ânus/cirurgia , Cicatriz/etiologia , Cicatriz/patologia , Endometriose/diagnóstico por imagem , Endometriose/cirurgia , Episiotomia , Feminino , Humanos , Resultado do Tratamento , UltrassonografiaRESUMO
BACKGROUND: Tomographic finding of thickening of colon and terminal ileum and its correlation with colonoscopic findings has been poorly studied. Various radiographic patterns of intestinal thickening suggestive of benign disease have been described, but they cannot completely rule out malignancy. OBJECTIVE: To determine if a relationship exists between colonic wall or terminal ileum thickening documented by computed tomography with abnormal colonoscopic findings and colon cancer. METHODS: Retrospective study of radiology database of a tertiary hospital identifying patients with report of thickening of terminal ileum or colon and have colonoscopy performed. It was investigated the performance of endoscopic biopsies and histopathological outcome. RESULTS: We included 24 patients. The main site of colonic thickening on CT was sigmoid in 8 (33.3%) cases. The most common colonoscopic finding was colorectal tumor probably malignant in 7 (29.2%) patients, but adenocarcinoma was reported in 8 (33.3%) patients. There was a statistically significant relationship between colonic thickening and colorectal cancer (p < 0.001) but no statistically significant association was found between thickening and sigmoid colon cancer. There was statistical significant correlation between weight loss, melena, anemia, constipation, diarrhea, and hematochezia with diagnosis of cancer (p < 0.01). CONCLUSIONS: The finding of thickening of colon documented by computed tomography is significantly associated with the presence of colorectal carcinoma. Additional colonoscopy must always be performed in an attempt to elucidate the origin of this thickening.
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Colo/diagnóstico por imagem , Colo/patologia , Neoplasias do Colo/diagnóstico , Colonoscopia , Íleo/diagnóstico por imagem , Íleo/patologia , Tomografia Computadorizada por Raios X , Adolescente , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Centros de Atenção Terciária , Adulto JovemRESUMO
INTRODUCTION: The rotator cuff tears are a very frequent condition. The rotator cuff repair is a procedure often perform by the orthopedic surgeon. There are multiple techniques and suture configurations for this type of repairs. The double row configuration is one of the most used and consider very effective for mid-size and large size rotator cuff tears. The parachute configuration for this repair is a novel technique that may be useful for mid-size and large size tears, for this repair two medial double row anchors are used and one knotless lateral anchor. Our porpoise was to compare biomechanical performance and footprint coverage of a conventional suture-bridge double-row rotator cuff repair configuration versus a double-row-parachute. METHODS: This paper shows the biomechanical behavior on a cadaver model of the parachute configuration, and also compares this conformation with a double row in a suture-bridge fashion. Our hipothesis was that the Parachute configurations biomechanical performance is equivalent to the suture-bridging double-row technique. RESULTS: The parachute configuration advantages show the advantage of using less anchors, which will decrease the surgical time and also the risks of using multiple hardware in the humeral head.
INTRODUCCIÓN: La lesión del manguito rotador es una patología común cuya reparación es un procedimiento realizado por los cirujanos ortopedistas. Existen muchas técnicas de reparación, así como múltiples configuraciones de anclas y suturas para realizar estos procedimientos. La técnica de doble fila es una de las más usadas para rupturas de tamaño mediano y grande con buenos resultados. La configuración en «paracaídas¼ para la reparación del manguito rotador puede llegar a ser útil para éstas, en este tipo de configuración se utilizan dos anclas mediales y un ancla sin nudos lateral. Nuestro objetivo fue la comparación de la eficiencia biomecánica y cobertura de la huella de una configuración convencional de doble fila «suture bridge¼ frente a una configuración en «paracaídas¼. MÉTODOS: Este trabajo revisó el comportamiento biomecánico, en piezas cadavéricas, de la configuración de paracaídas y se comparó con la configuración de doble fila tipo «suture-bridge¼. Nuestra hipótesis era que el rendimiento biomecánico de la configuración de Parachute es equivalente a la técnica de doble fila «suture bridge¼. RESULTADOS: Las posibles ventajas de la configuración de paracaídas son el uso de menos anclas, disminuyendo el tiempo quirúrgico y los riesgos de tener múltiples implantes en la cabeza humeral.
Assuntos
Lesões do Manguito Rotador , Fenômenos Biomecânicos , Humanos , Manguito Rotador/cirurgia , Lesões do Manguito Rotador/cirurgia , Técnicas de Sutura , SuturasRESUMO
In this work was to evaluate the conidiospores production of Trichoderma harzianum using barley straw as substrate. Four growth conditions were used; washed and unwashed barley straw and washed and unwashed barley straw supplemented with mineral salts. The highest spore production was observed when washed barley straw supplemented with mineral salts with 1.56â¯×â¯1010 conidiospores/gram of dry matter (gdm) at 216â¯h of cultivation was used. The effect of substrate moisture on spore production was studied, three initial moisture levels of the substrate were tested and it was observed that a humidity of 80 % of the substrate improves the production of conidiospores reaching a concentration of 2.35â¯×â¯1010 conidiospores/gdm at 136â¯h. Finally, conidiospores viability was evaluated for 12 months by keeping them on the conidia and substrate, and viability of 71 % of the conidiospores was observed, so this maintenance method is an excellent means of conserving the conidiospores viability.
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Since 1974, the Bachelor of Biomedical Engineering Program (BBME) is offered at Universidad Autónoma Metropolitana-Iztapalapa, in Mexico City. By design, it must be completed in four years (12 trimesters) and, in the latter three, the senior students work on a BME project, which is done by completing three modules: Project Seminar (PS), Project on BME I and Project on BME II. In the PS module, the student must find a problem of interest in the BME field and suggest a solution through the development of an Engineering Project Proposal (EPP). Currently, the module is being taught by two faculty members of the BBME, who instruct students on how to develop their EPPs and evaluate their progress by reviewing a number of EPPs during the trimester. This generates a huge workload for the module instructors, which makes it necessary to involve more faculty members trimester-to-trimester (i.e. every 12 weeks) and, therefore, to create a set of systematic guidelines that ease the evaluation process for new instructors. Hence, the purpose of this paper is to present an assessment strategy (in the form of an assessment matrix) for the PS module as well as some preliminary results after two trimesters of its implementation.
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Engenharia Biomédica/educação , Currículo/normas , Estudantes , Universidades/normas , Engenharia Biomédica/normas , Humanos , MéxicoRESUMO
Abstract: Introduction: The rotator cuff tears are a very frequent condition. The rotator cuff repair is a procedure often perform by the orthopedic surgeon. There are multiple techniques and suture configurations for this type of repairs. The double row configuration is one of the most used and consider very effective for mid-size and large size rotator cuff tears. The parachute configuration for this repair is a novel technique that may be useful for mid-size and large size tears, for this repair two medial double row anchors are used and one knotless lateral anchor. Our porpoise was to compare biomechanical performance and footprint coverage of a conventional suture-bridge double-row rotator cuff repair configuration versus a double-row-parachute. Methods: This paper shows the biomechanical behavior on a cadaver model of the parachute configuration, and also compares this conformation with a double row in a suture-bridge fashion. Our hipothesis was that the Parachute configuration's biomechanical performance is equivalent to the suture-bridging double-row technique. Results: The parachute configuration advantages show the advantage of using less anchors, which will decrease the surgical time and also the risks of using multiple hardware in the humeral head.
Resumen: Introducción: La lesión del manguito rotador es una patología común cuya reparación es un procedimiento realizado por los cirujanos ortopedistas. Existen muchas técnicas de reparación, así como múltiples configuraciones de anclas y suturas para realizar estos procedimientos. La técnica de doble fila es una de las más usadas para rupturas de tamaño mediano y grande con buenos resultados. La configuración en «paracaídas¼ para la reparación del manguito rotador puede llegar a ser útil para éstas, en este tipo de configuración se utilizan dos anclas mediales y un ancla sin nudos lateral. Nuestro objetivo fue la comparación de la eficiencia biomecánica y cobertura de la huella de una configuración convencional de doble fila «suture bridge¼ frente a una configuración en «paracaídas¼. Métodos: Este trabajo revisó el comportamiento biomecánico, en piezas cadavéricas, de la configuración de paracaídas y se comparó con la configuración de doble fila tipo «suture-bridge¼. Nuestra hipótesis era que el rendimiento biomecánico de la configuración de Parachute es equivalente a la técnica de doble fila «suture bridge¼. Resultados: Las posibles ventajas de la configuración de paracaídas son el uso de menos anclas, disminuyendo el tiempo quirúrgico y los riesgos de tener múltiples implantes en la cabeza humeral.
Assuntos
Humanos , Lesões do Manguito Rotador/cirurgia , Suturas , Fenômenos Biomecânicos , Técnicas de Sutura , Manguito Rotador/cirurgiaRESUMO
Larval and adult extracts from isolates of Haemonchus contortus were assayed for specific [3H]levamisole binding activity. All of the tissue preparations displayed [3H]levamisole binding sites. The sensitive isolate SE and resistant isolate RJ showed no differences in larval and adult binding data. Larval SE extracts had higher receptor density (Bmax = 648 fmol mg-1) and dissociation constant (Kd = 1.28 microM) for [3H]levamisole than larval extracts of the American isolate RUSA (Bmax = 87 fmol mg-1 and Kd = 0.15 microM). Extracts of adult SE and RUSA isolates contain as much as 327 fmol mg-1 of protein and 205 fmol mg-1 of protein, respectively, and similar dissociation constants (Kd = 0.77 microM and Kd = 0.81 microM, respectively). There was a good correlation between specific binding activity of larval and adult extracts in both SE and RUSA isolates. The nicotinic cholinergic antagonist alpha-bungarotoxin had no effects in either isolate on [3H]levamisole binding activity. The results confirm that levamisole acts at a cholinergic receptor in H. contortus, and suggest that target site modification could be involved in the development of levamisole resistance.
Assuntos
Antinematódeos/metabolismo , Haemonchus/metabolismo , Levamisol/metabolismo , Receptores Colinérgicos/metabolismo , Animais , Antinematódeos/farmacologia , Sítios de Ligação , Ligação Competitiva , Bungarotoxinas/farmacologia , Antagonistas Colinérgicos/farmacologia , Resistência a Medicamentos/fisiologia , Fezes/parasitologia , Haemonchus/efeitos dos fármacos , Levamisol/farmacologia , Contagem de Ovos de Parasitas , Receptores Colinérgicos/fisiologia , OvinosRESUMO
This study compares the purity indices found after purifying tubulin obtained from the nematode parasite Trichinella spiralis, using different chromatographic and electrophoretic methods. Affinity chromatography, using monoclonal antibodies anti-alpha and anti-beta-tubulin fixed to activated Sepharosa 4B-CNBr, yields a tubulin purity of 15%. In contrast, by means of interchange-anionic chromatography using a column of DEAE-Sephadex-A50, we obtained an increase in purity of up to 75%. Finally, with the combined application of preparative electrophoresis and electroelution of proteins in polyacrylamide gels with SDS, we obtained the best results with a purity reaching 90%.
Assuntos
Trichinella spiralis/química , Tubulina (Proteína)/isolamento & purificação , Animais , Anticorpos Monoclonais/imunologia , Cromatografia de Afinidade , Cromatografia por Troca Iônica , Eletroforese em Gel de Poliacrilamida , Tubulina (Proteína)/imunologiaRESUMO
A protease from excretion-secretion products of Trichinella spiralis muscle-stage larvae was purified by continuous elution electrophoresis. The state of purification was analyzed electrophoretically using one- and two-dimensional sodium dodecyl sulfate polyacrylamide gel electrophoresis. The purified enzyme was shown to be a single polypeptide with an estimated molecular mass of 35 kDa and isoelectric point of 6.2. Following purification, the enzyme activity was measured by hydrolysis of gelatin, azocoll, azoalbumin, azocasein and collagen as substrates. Maximal azocollytic activity was at pH 5 and a temperature of 37 degrees C. Finally, the proteolytic activity was partially inhibited by N-alpha-p-tosyl-lysine chloromethyl ketone, chymostatin and E-64.
Assuntos
Endopeptidases/isolamento & purificação , Endopeptidases/metabolismo , Músculos/parasitologia , Trichinella spiralis/enzimologia , Amidoidrolases , Animais , Colorimetria , Eletroforese em Gel Bidimensional , Eletroforese em Gel de Poliacrilamida , Cinética , Larva , Camundongos , Camundongos Endogâmicos , Peso Molecular , Peptídeo-N4-(N-acetil-beta-glucosaminil) Asparagina Amidase , Inibidores de Proteases/farmacologia , Trichinella spiralis/parasitologiaRESUMO
Trichinella spiralis larvae infect their hosts by the penetration of small intestine enterocytes. The exact mechanism of penetration is unknown, but the presence of proteolytic enzymes is suspected. In this study, whole worm extracts and excretory-secretory (ES) components were obtained and their proteolytic enzymes examined. Enzymes from worm extracts were capable of hydrolysing azocoll, a general protease substrate in a wide range of pH (2-8), with maximal activity at pH 5. Trichinella spiralis larval enzymes were sensitive to metalloprotease and serine protease inhibitors. Three proteases were identified in worm extracts at molecular weight (MW) 48, 54 and 62 kDa by incorporating a gelatine substrate into a standard or a modified sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) set-up, in which we used low SDS concentration in gel and electrophoresis buffer (0.01%). Intact larvae incubated in a medium containing azocoll showed azocollytic activity. Subsequent analysis of ES products by modified SDS-PAGE in gels containing gelatine demonstrated the presence of three protease of apparent MW 33, 62 and 230 kDa.
Assuntos
Endopeptidases/análise , Trichinella spiralis/enzimologia , Animais , Compostos Azo/metabolismo , Colágeno/metabolismo , Colorimetria , Corantes/metabolismo , Eletroforese em Gel de Poliacrilamida , Endopeptidases/química , Endopeptidases/metabolismo , Concentração de Íons de Hidrogênio , Hidrólise , Larva/enzimologia , Peso MolecularRESUMO
Tubulin was estimated to account for 0.3% of the total soluble protein in Trichinella spiralis cytosolic fractions. Tubulin from T. spiralis was partially purified by precipitation with either taxol or vinblastine sulphate. Immunoblotting with alpha- and beta-tubulin monoclonal antibodies revealed the presence of tubulin in T. spiralis partially purified preparations. Electrophoretic mobility of T. spiralis tubulin in sodium dodecyl sulphate-polyacrylamide gels was very similar to that shown by pig brain tubulin. Further studies with colchicine binding assays indicated that T. spiralis tubulin has binding features similar to that of tubulin from other nematodes: colchicine association constant = 8.1 x 10(-4) M and competitive inhibition of colchicine binding by podophyllotoxin, with an inhibition constant of 1.3 x 10(-6) M. Finally, inhibition of colchicine binding by several benzimidazoles (mebendazole, fenbendazole, oxibendazole and albendazole) was investigated. All the benzimidazoles inhibited colchicine binding in a competitive manner, with inhibition constant values ranging from 1.4 x 10(-7) M (mebendazole) to 3.9 x 10(-6) M (fenbendazole).
Assuntos
Benzimidazóis/metabolismo , Trichinella/análise , Tubulina (Proteína)/análise , Albendazol/metabolismo , Animais , Anti-Helmínticos/metabolismo , Ligação Competitiva , Colchicina/metabolismo , Eletroforese em Gel de Poliacrilamida , Fenbendazol/metabolismo , Immunoblotting , Mebendazol/metabolismo , Tubulina (Proteína)/química , Tubulina (Proteína)/isolamento & purificação , Tubulina (Proteína)/metabolismoRESUMO
The biodegradation route of the octylphenol ethoxylates (OPEOs) by denitrification in an upflow anoxic sludge blanket (UASB) reactor was studied. An anaerobic sludge adapted to denitrifying conditions with acetate was adapted with increasing amounts of OPEOs and diminishing amounts of acetate until only 300 mg x L(-1) of OPEOs were fed. Only 70% of stoichiometric NO3- was fed so partial removal was expected. The total OPEOs fed was transformed with 70% COD removal. HPLC and GC-MS analyses showed that octylphenol (OP) was immediately formed but disappeared while other intermediates, the ethoxylated moieties; mono and diethoxylate (OPEO1 and OPEO2 respectively) led to the cleavage of the alkyl chain to form propylphenol triethoxylate (PPEO3) and heptylphenol diethoxylated (HPEO2). These last two compounds are produced due to an attack to both sides of the molecule; the hydrophilic and the hydrophobic. These findings suggest three simultaneous routes of OPEO degradation.
Assuntos
Reatores Biológicos , Fenóis/metabolismo , Tensoativos/metabolismo , Bactérias Anaeróbias , Biodegradação Ambiental , Polímeros , Eliminação de Resíduos Líquidos/métodosRESUMO
Nonionic surfactants are used worldwide in various industrial and household applications. Since these compounds are used in aqueous solutions, they primarily enter the environment through sewage and industrial wastewater treatment plants. The objective of this work was to evaluate the inhibitory effect of Triton X-100, a commercial nonionic surfactant, on the anaerobic digestion of lactose. Thus non-ionic surfactants acts as a non-competitive inhibitor with K1 = 250 mgL-1 and a inhibition order of 2.4. Nonetheless if give enough time the sludge was able to degrade 79% of Triton at 0.1 gL-1 d-1 in a UASB reactor. An activity test of this sludge showed that Triton inhibited the acetogenic (both propionic and butyric) and acetoclastic activities, while there were high fermentative and hydrogenotrophic activities (80% and 95%, respectively).
Assuntos
Bactérias Anaeróbias/fisiologia , Detergentes/química , Octoxinol/química , Tensoativos/metabolismo , Eliminação de Resíduos Líquidos/métodos , Biodegradação Ambiental , Produtos Domésticos , Lactose/metabolismo , Purificação da ÁguaRESUMO
Today, it is generally accepted that current methods for biophysical antenatal surveillance do not facilitate a comprehensive and reliable assessment of foetal well-being and that continuing research into alternative methods is necessary to improve antenatal monitoring procedures. In our research, attention has been paid to the abdominal phonogram, a signal that is recorded by positioning an acoustic sensor on the maternal womb and contains valuable information about foetal status, but which is hidden by maternal and environmental sources. To recover such information, previous work has used single-channel independent component analysis (SCICA) on the abdominal phonogram and successfully retrieved estimates of the foetal phonocardiogram, the maternal phonocardiogram, the maternal respirogram and noise. The availability of these estimates made it possible for the current study to focus on their evaluation as sources for antenatal surveillance purposes. To this end, the foetal heart rate (FHR), the foetal heart sounds morphology, the maternal heart rate (MHR) and the maternal breathing rate (MBR) were collected from the estimates retrieved from a dataset of 25 abdominal phonograms. Next, these parameters were compared with reference values to quantify the significance of the physiological information extracted from the estimates. As a result, it has been seen that the instantaneous FHR, the instantaneous MHR and the MBR collected from the estimates consistently followed the trends given by the reference signals, which is a promising outcome for this preliminary study. Thus, as far as this study has gone, it can be said that the independent traces retrieved by SCICA from the abdominal phonogram are likely to become valuable sources of information for well-being surveillance, both foetal and maternal.
Assuntos
Abdome , Acústica , Monitorização Fetal/métodos , Feto/fisiologia , Estudos de Viabilidade , Feminino , Frequência Cardíaca Fetal , Humanos , Mães , Gravidez , Respiração , Estatística como Assunto , Adulto JovemRESUMO
This work explored the suitability of using the foetal phonocardiogram (FPCG) blindly separated from the abdominal phonogram as a source for foetal heart rate (FHR) measuring in antenatal surveillance. To this end, and working on a dataset of 15 abdominal phonograms, the FPCG was estimated by using two de-noising approaches (1) single-channel independent component analysis (SCICA) to produce FPCG(e) and (2) empirical filtering to produce FPCG(g). Next, the FPCGs were further processed to collect the beat-to-beat FHR and the resulting time-series (FCTG(e) and FCTG(g) were compared to the reference signal given by the abdominal ECG (FCTG(r)). Results are promising, the FPCG(e) gives rise to a FCTG(e) that resembles FCTG(r) and, most importantly, whose mean FHR value is statistically equivalent to that given by FCTG(r) (p > 0.05). Thus, the mean FHR value obtained from the FPCG(e), is likely to be equivalent to the value given by the abdominal ECG, which is especially significant since the FPCG(e) is retrieved from the noisy abdominal phonogram. Hence, as far as this study has gone, it can be said that, when using SCICA to de-noise the abdominal phonogram, the resulting FPCG is likely to become a useful source for FHR collection in antenatal surveillance.
Assuntos
Abdome/fisiologia , Frequência Cardíaca Fetal/fisiologia , Adulto , Algoritmos , Eletrocardiografia , Feminino , Idade Gestacional , Humanos , Fonocardiografia , Gravidez , Processamento de Sinais Assistido por Computador , Razão Sinal-RuídoRESUMO
Recorded by positioning a sensitive acoustic sensor over the maternal womb, the abdominal phonogram is a signal that contains valuable information for foetal surveillance (e.g. heart rate), which is hidden by maternal and environmental sources. To recover such information, previous work used single-channel independent component analysis (SCICA) to separate the abdominal phonogram into statistically independent components (ICs) that, once acquired, must be objectively associated with the real sources underlying the abdominal phonogram-either physiological or environmental. This is a typical challenge for blind source separation methodologies and requires further research on the signals of interest to find a suitable solution. Here, we have conducted a joint study on 75 sets of ICs by means of statistical, spectral, complexity and time-structure analysis methods. As a result, valuable and consistent characteristics of the components separated from the abdominal phonogram by SCICA have been revealed: (1) the ICs are spectrally disjoint and sorted according to their frequency content, (2) only the ICs with lower frequency content present strong regular patterns and (3) such regular patterns are driven by well-known physiological processes given by the maternal breathing rate, the maternal heart rate and the foetal heart rate. This information was so promising that it has been used in current work for automatic classification of ICs and recovery of the traces of the physiological sources underlying the abdominal phonogram. Future work will look for the extraction of information useful for surveillance (e.g. heart rate), not only about foetal well-being, but also about maternal condition.
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Resumen: El Potencial de disparidad es una respuesta cortical elicitada por la detección automática de estímulos con distintas características, permitiendo la exploración de procesos neuropsicológico. Sin embargo el análisis de esta señal se puede dificultar por una baja relación señal a ruido debida a los artefactos presentes en la adquisición de la misma. Diversas publicaciones proponen el uso de implementaciones de la técnica de Separación Ciega de fuentes, como el Análisis por Componentes Independientes (ACI), para preprocesar las señales y eliminar estos artefactos. Sin em bargo, no se ha estudiado cuál de los algoritmos ACI que se encuentran en la literatura será el óptimo para mejorar la calidad del MMN, por lo que en este estudio se propuso determinar si existen diferencias significativas en las respuestas obtenidas al utilizar los algoritmos de FastICA, Infomax y SOBI para eliminar los artefactos típicamente presentes en este tipo de señales. Adicionalmente se dan algunas características de estos artefactos a manera de sistematizar la identificación y eliminaciones de los mismos, además de comparar las respuestas obtenidas con y sin preprocesamiento, así como la distribución topográfica de este potencial antes y después de la eliminación de artefactos. Mediante el algoritmo Infomax se identifican mejor los Componentes Independientes asociados con artefactos, resultando en un MMN de mayor amplitud y distribución topográfica fronto-central con predominancia izquierda.
Abstract: Mismatch Negativity is a cortical response elicited by the automatic detection of stimuli which have different characteristics, allowing exploration of neuropsychological processes. However, the analysis of this signal can be di fficult by a low SNR due to artifacts present when the signal is recorded. Different publications propose to use the approach given by the Blind Source Separation Technique by means of the Independent Component Analysis (ICA) to preprocess and eliminate these artifacts. Nevertheless, it has not been studied which of the ICA algorithms found in the literature will be optimal for improving the quality of MMN. Therefore the aim of this study is to determine whether there are significant differences in the responses obtained by using FastICA, Infomax and SOBI to remove artifacts typically present in such signals. In addition, some features of the Independent Components related to artifacts are given in order to systematize the identification and elimination of those. In addition, MMN responses obtained with and without data preprocessing, as well as topographic maps before and after the elimination of artifacts were compared. Thus, Infomax is the best ICA algorithm to calculate Independent Components associated with artifacts, resulting in high amplitude MMN and a topographic map with a clear fronto-central distribution with left-hemisphere predominance.
RESUMO
A biodecolorization model that considers the simultaneous mechanism of biosorption and biodegradation of a synthetic dye by immobilized white-rot fungus Trametes subectypus B32 in a fixed bed bioreactor was developed. The model parameters (biokinetic, biosorption and macroscopic transport) were determined by independent experiments. The biodecolorization model was used to determine the effect of variables such as immobilized biomass content, volumetric flow of wastewater, dye feeding concentration and initial dye concentration. By means of the model was possible to predict in the steady state, the limits of immobilized T. subectypus to biodecolorize polluted influent, being the model predictions similar in extent to previous reports. A dimensionless module of biosorption-bioreaction (Ï=q(max)v(z)/r(max)L) was proposed to be used like criterion whenever one of the two mechanisms controls the biodecolorization. The model could be used for the designing and scaling up of fixed bed bioreactors with immobilized white-rot fungi for the biodecolorization process.