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1.
Matern Child Nutr ; 15 Suppl 3: e12791, 2019 05.
Artículo en Inglés | MEDLINE | ID: mdl-31148399

RESUMEN

Good nutrition during a child's early years lays a strong foundation of health for the rest of its life. Yet in India, there is widespread prevalence of undernourishment among children below 5 years of age. Within the Indian context, small millets have great potential as a healthy food to address this challenge by the virtue of their nutritional qualities. However, there are many problems with the current processing technology for small millets, whereas the use of value-added products was minimal. To address this, an assessment of existing small millet processing machinery was undertaken, and a double chamber centrifugal dehuller was developed, which had higher recovery of dehulled unpolished millets and met requirements at the village and enterprise levels. To demonstrate the health benefits of consuming value-added small millets, a study of supplementation of multi-millet health mix on the nutritional status of primary schoolchildren was conducted in Thondamuthur Block of Coimbatore District, India. Multi-millet health mix was formulated from kodo millet, little millet, foxtail millet, finger millet, and wheat with the inclusion of pulses. It contained 65.45-g carbohydrate, 11.46-g protein, 4.94-g fat, 4.94-g fibre, 4.07-mg iron, 112-mg calcium, 268.52-mg phosphorus, and 349 calories of energy per 100 g. The study indicated that there was a significant increase in height, weight, and haemoglobin level of the schoolchildren who regularly consumed the formulated multi-millet health mix. The improved huller and value-added food product developed can be feasible options for improving nutrition security and livelihoods through increased use of small millets.


Asunto(s)
Centrifugación/instrumentación , Suplementos Dietéticos , Desnutrición/prevención & control , Mijos , Valor Nutritivo , Panicum , Niño , Preescolar , Grano Comestible , Tecnología de Alimentos/instrumentación , Humanos , India/epidemiología , Estado Nutricional
2.
J Exp Bot ; 70(18): 4865-4876, 2019 09 24.
Artículo en Inglés | MEDLINE | ID: mdl-31056686

RESUMEN

Significant improvements to the centrifuge water-extraction method of measuring the percentage loss volume of water (PLV) and corresponding vulnerability curves (VCs) are reported. Cochard and Sperry rotors are both incapable of measuring the VCs of species with long vessels because of premature embolism induced by hypothetical nanoparticles that can be drawn into segments during flow measurement. In contrast, water extraction pushes nanoparticles out of the sample. This study focuses on a long-vessel species, Robinia pseudoacacia, for which many VCs have been constructed by different methods, and the daily water relations have been quantified. PLV extraction curves have dual Weibull curves, and this paper focuses on the second Weibull curve because it involves the extraction of water from vessels, as proven by staining methods. We demonstrate an improved water extraction method after evaporation correction that has accuracy to within 0.5%, shows good agreement with two traditional methods that are slower and less accurate, and is immune to nanoparticle artefacts. Using Poiseuille's Law and the geometry of vessels, we argue that the percentage loss of conductivity (PLC) equals 2PLV-PLV2 in a special case where all vessels, regardless of size, have the same vulnerability curve. In this special case, this equation predicts the data reasonably well.


Asunto(s)
Centrifugación/instrumentación , Robinia/metabolismo , Agua/metabolismo , Xilema/metabolismo , Botánica/instrumentación
3.
Tree Physiol ; 39(1): 156-165, 2019 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-29788216

RESUMEN

Cavitation resistance is a key trait for characterizing the drought adaption in plants and is usually presented in terms of vulnerability curves. Three principal techniques have been developed to produce vulnerability curves, but curves generated with centrifugation are reported to suffer from artifacts when applied to long-vesseled species. The main cause of this artifact is the issue of open vessels, resulting in a nano-particle effect that may seed premature embolism. We used two methods to test the potential mechanism behind the nano-particle effect in centrifuge-based vulnerability curves. A four-cuvette rotor system based on a traditional Cochard rotor was designed to inhibit effervescence while injecting water, but the recalcitrant vulnerability curves in Robinia could not be eliminated. There may be multiple sources, besides effervescence, of hypothetical nano-particles: they may arise from cut surfaces or they may be always present in the injected water, leading to the premature embolisms. To prevent the entry of the hypothetical nano-particles, water extraction curves in terms of PLV (percentage loss volume of extracted water from stems) vs tensions were constructed. The PLV curves of Robinia showed s-shaped characteristics after subtracting the first Weibull components from water extraction curves, which were not related to the water loss from vessels according to dye staining experiments. The differences between T50 (xylem tension at which 50% of hydraulic conductivity is lost) in mean PLV curve and T50 in percentage loss of conductivity curves determined by the four-cuvette rotor system and by the bench dehydration method were 3.9 MPa and 0.7 MPa, respectively. Hence, PLV curves may be a valid way to measure the cavitation resistance in long-vesseled species with centrifugation. Keeping bark intact in the process of measurement is recommended, otherwise it would increase evaporation from the entire system.


Asunto(s)
Aclimatación , Centrifugación/métodos , Nanopartículas , Enfermedades de las Plantas , Robinia/fisiología , Calibración , Centrifugación/instrumentación , Resistencia a la Enfermedad , Sequías , Tallos de la Planta/fisiología , Agua
4.
Biochem Med (Zagreb) ; 28(2): 020902, 2018 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-29666561

RESUMEN

INTRODUCTION: Obtaining suitable results unaffected by pre- or postanalytical phases is pivotal for clinical chemistry service. We aimed comparison and stability of nine biochemical analytes after centrifugation using Barricor™ plasma tubes with mechanical separator vs standard Vacutainer® lithium heparin tubes. MATERIALS AND METHODS: We collected samples on six healthy volunteers and nine patients from intensive care units into 6 mL plastic Vacutainer® lithium heparin tubes and 5.5 mL plastic Barricor™ plasma tubes. All tubes were centrifuged within 30 minutes after venipuncture. First, we compared results of nine biochemical analytes from lithium heparin tubes with Barricor™ tubes for each analyte using Passing-Bablok and Bland-Altman analyses. Second, we calculated the difference of analyte concentrations between baseline and time intervals in tubes stored at + 4 °C. Based on the total change limit we calculated the maximum allowable concentrations percentage change from baseline. RESULTS: The majority of correlation coefficients were close to 0.99 indicating good correlation in the working range. Bland-Altman analyses showed an acceptable concordance for all analytes. In consequence, the Barricor™ tube might be an alternative to regular lithium heparin tube. Stability with this new generation tube is improved for eight analytes (except for aspartate aminotransferase) in comparison with regular lithium heparin tubes. CONCLUSIONS: By using Barricor™ tubes and prompt centrifugation, supplemental analysis or re-analysis for eight analytes including alanine aminotransferase, alkaline phosphatase, C-reactive protein, high sensitivity troponin T, lactate dehydrogenase, NT-pro BNP, potassium and sodium could be performed within 72 h of specimen collection.


Asunto(s)
Recolección de Muestras de Sangre/instrumentación , Centrifugación/instrumentación , Alanina Transaminasa/sangre , Fosfatasa Alcalina/sangre , Anticoagulantes/química , Biomarcadores/sangre , Recolección de Muestras de Sangre/normas , Proteína C-Reactiva/metabolismo , Estudios de Casos y Controles , Cationes Monovalentes , Enfermedad Crítica , Heparina/química , Humanos , Unidades de Cuidados Intensivos , L-Lactato Deshidrogenasa/sangre , Litio/química , Péptido Natriurético Encefálico/sangre , Fragmentos de Péptidos/sangre , Potasio/sangre , Sodio/sangre , Troponina T/sangre
5.
J Chromatogr A ; 1504: 55-63, 2017 Jun 30.
Artículo en Inglés | MEDLINE | ID: mdl-28515006

RESUMEN

The Edelweiss plant has been recognized as a very valuable source of anti-aging principles due to its composition of antioxidants compounds: leontopodic acid A and 3,5-dicaffeoylquinic acid. In this work, off-line multi-heart cutting CPC-LC separation was set up at industrial scale in order to isolate and produce new high quality reference material of these two antioxidants from Edelweiss. For this purpose, CPC and HPLC methods were developed and optimized at laboratory scale and a comprehensive CPCxHPLC analysis of the crude extract was established. Thereby, the CPC method led to a first separation of the target compounds according to their partition coefficient in the solvent system and the HPLC method was performed on the recovered fractions to lead to a second separation. A 2D CPCxHPLC plot was established in order to know the fractions to select at the industrial scale. Then, the CPC and HPLC methods were transferred at industrial scale and the multi-heart cutting CPC-LC was performed in off-line mode. Using CPC with methyl ter-butyl ether-water 1:1 (v/v) solvent system and LC with Denali C18 column, 2g of crude extract sample were injected and leontopodic acid A and 3,5-dicaffeoylquinic acid were recovered with purity over 97%. The compounds were identified by MS and NMR.


Asunto(s)
Antioxidantes/aislamiento & purificación , Asteraceae/química , Centrifugación/métodos , Cromatografía Líquida de Alta Presión/métodos , Extractos Vegetales/aislamiento & purificación , Antioxidantes/análisis , Centrifugación/instrumentación , Cromatografía Líquida de Alta Presión/instrumentación , Espectroscopía de Resonancia Magnética , Extractos Vegetales/química
6.
J Extra Corpor Technol ; 48(4): 168-172, 2016 12.
Artículo en Inglés | MEDLINE | ID: mdl-27994256

RESUMEN

Autotransfusion protocols often use the use of costly filters, such as leukocyte-depleting filters (LDFs), to minimize reinfusion of activated leukocytes and inflammatory mediators associated with reperfusion injury (RI). LDFs are used extensively in hospital settings; however, they represent an additional capital expenditure for hospitals, as well as a constraint on the reinfusion rate of blood products for health-care providers. We compared a commonly used LDF to a novel centrifugation method employing a widely used cell salvage device. Complete blood counts and enzyme-linked immunosorbent assays (ELISAs) measuring tumor necrosis factor-α (TNF-α) and interleukin-2 (IL-2) were performed to compare the efficacy of these methodologies. The LDF removed, on average, 94% of all leukocytes, including 96% of neutrophils. The centrifugation method removed, on average, 89% of all leukocytes, including 91% of neutrophils and resulted in a highly concentrated red blood cell product. Our results suggest both methods offer equivalent leukocyte reduction. TNF-α was also comparably reduced following our novel centrifugation method and the LDF method and IL-2 levels were undetectable in all samples. These results indicate our novel centrifugation method may preclude the need for a LDF during select autotransfusion applications.


Asunto(s)
Transfusión de Sangre Autóloga/instrumentación , Centrifugación/instrumentación , Procedimientos de Reducción del Leucocitos/instrumentación , Leucocitos/citología , Recuperación de Sangre Operatoria/instrumentación , Ultrafiltración/instrumentación , Animales , Transfusión de Sangre Autóloga/métodos , Bovinos , Células Cultivadas , Diseño de Equipo , Análisis de Falla de Equipo , Recuento de Leucocitos
7.
Lab Chip ; 15(17): 3572-80, 2015 Sep 07.
Artículo en Inglés | MEDLINE | ID: mdl-26215661

RESUMEN

Drug screening and profiling is an important phase in drug discovery, development, and marketing. However, some profiling tests are not routinely done because of the needed additional technical skills and costly maintenance, which leads to cases of unexpected side effects or adverse drug reactions (ADRs). This study presents the design and operation of a microfluidic chip for single-cell level drug screening and profiling as an alternative platform for this purpose. Centrifugation was utilized to trap isolated single and groups of primary cultured neonatal rat cardiomyocytes in the same chip. In the off-spin operation of the chip, the cells can be observed under a microscope and movies of the beat motion can be recorded. The beat profiles of the cells were generated by image correlation analysis of the recorded video to study the contractile characteristics (beating rate, beating strength, and inter-beat duration). By utilizing this non-invasive tool, long term continuous monitoring, right after trapping, was made possible and cell growth and dynamics were successfully observed in the chip. Media and liquid replacement does not require further centrifugation but instead utilizes capillary flow only. The effect of carbachol (100 µM) and isoproterenol (4 µg mL(-1)) on single cells and groups of cells was demonstrated and the feature for immunostaining (ß-actin) applicability of the chip was revealed. Furthermore, these findings can be helpful for the headway of non-invasive profiling of cardiomyocytes and for future chip design and operation of high-throughput lab-on-a-chip devices.


Asunto(s)
Centrifugación/instrumentación , Descubrimiento de Drogas/instrumentación , Evaluación Preclínica de Medicamentos/instrumentación , Técnicas Analíticas Microfluídicas/instrumentación , Miocitos Cardíacos/citología , Análisis de la Célula Individual , Animales , Diseño de Equipo , Contracción Miocárdica , Miocitos Cardíacos/efectos de los fármacos , Ratas , Análisis de la Célula Individual/instrumentación , Análisis de la Célula Individual/métodos
8.
Anal Bioanal Chem ; 406(4): 957-69, 2014 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-23748592

RESUMEN

Countercurrent chromatography (CCC) is an attractive separation method because the analytes are partitioned between two immiscible liquid phases avoiding problems related to solid stationary phase. In recent years, this technique has made great progress in separation power and detection potential. This review describes coupling strategies involving high speed CCC (HSCCC) or centrifugal partition chromatography (CPC). It includes on-line extraction-isolation, hyphenation with mass spectrometry (MS) and nuclear magnetic resonance (NMR) detectors, multidimensional CCC (MDCCC), two-dimensional CCC (2D-CCC), on-line coupling with liquid chromatography (LC), and biological tests, and innovative off-line developments. The basic principles of each method are presented and applications are summarized.


Asunto(s)
Centrifugación/tendencias , Distribución en Contracorriente/tendencias , Animales , Centrifugación/instrumentación , Centrifugación/métodos , Cromoterapia/instrumentación , Cromoterapia/métodos , Cromoterapia/tendencias , Distribución en Contracorriente/instrumentación , Distribución en Contracorriente/métodos , Humanos , Péptidos/análisis , Péptidos/aislamiento & purificación , Extractos Vegetales/análisis , Extractos Vegetales/aislamiento & purificación
9.
Transfusion ; 53(5): 1001-9, 2013 May.
Artículo en Inglés | MEDLINE | ID: mdl-22897672

RESUMEN

BACKGROUND: Storage lesions in red blood cells (RBCs) lead to an accumulation of soluble contaminants that can compromise the patient. Organ failures, coagulopathies, and cardiovascular events including lethal cardiac arrest have been reported, especially with massive transfusion or in pediatric patients. Washing improves the quality of stored RBCs, and autotransfusion devices have been proposed for intraoperative processing, but these devices were designed for diluted wound blood, and limited data on their performance with RBCs are available. STUDY DESIGN AND METHODS: Three autotransfusion devices (Electa, Sorin; CATS, Fresenius; OrthoPAT, Haemonetics) differing in function of their centrifugation chambers were evaluated with RBCs at the end of their shelf life and with dilutions thereof. Elimination rates of potassium, plasma free hemoglobin, total protein, citrate, acid equivalents, and iomeprol added as a marker substance were analyzed, in addition to RBC recoveries. RESULTS: Product hematocrit (Hct) levels ranged between 54.8 and 72.6%. RBC recovery rates were between 62.7 and 95.0%, the lowest being with the OrthoPAT processing of undiluted RBCs. Plasma elimination rates increased with predilution and ranged from 46.6% to 99.5%, the lowest being with the CATS and undiluted RBCs. Washing did not change pH and buffering capacity of RBCs. CONCLUSION: Autotransfusion devices offer a practical and obviously economical option to wash banked RBCs intraoperatively to prevent hyperkalemia and other disturbances in massive transfusion or pediatric patients. Predilution improves elimination rates, especially in devices that produce high product Hct levels. With a Y-tubing the RBCs should bypass reservoir and vacuum, and the procedure should be guarded by a policy and procedure manual and a quality management system.


Asunto(s)
Seguridad de la Sangre/instrumentación , Transfusión de Sangre Autóloga/instrumentación , Transfusión de Eritrocitos/instrumentación , Recuperación de Sangre Operatoria/instrumentación , Biomarcadores/sangre , Bancos de Sangre , Proteínas Sanguíneas/análisis , Centrifugación/instrumentación , Cromatografía Líquida de Alta Presión , Ácido Cítrico/sangre , Hematócrito , Humanos , Concentración de Iones de Hidrógeno , Yopamidol/análogos & derivados , Yopamidol/sangre
10.
Rev Enferm ; 35(3): 28-32, 2012 Mar.
Artículo en Español | MEDLINE | ID: mdl-22670388

RESUMEN

The blood retrievers are instruments increasingly used in operating rooms. They are especially useful in operations where there is a high risk of bleeding and transfusion requirements are high. In paediatrics is of great importance in complex interventions in order to avoid allogeneic transfusion (blood collected from donors). The implementation of the recovery of blood in the surgical field is very simple and easy to use. This is a suction tube that collects the blood that is free, transferring it to a centrifuge where it is filtered and washed, stored in a blood collection bag for subsequent infusion. The blood is of high quality and contains a high hematocrit blood from the bank.


Asunto(s)
Transfusión de Sangre Autóloga/instrumentación , Células Sanguíneas , Centrifugación/instrumentación , Diseño de Equipo , Humanos , Cuidados Intraoperatorios
11.
Methods Mol Biol ; 835: 603-10, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22183681

RESUMEN

Upon infection of plants by pathogens, at least at the early stages of infection, the interaction between the two organisms occurs in the apoplast. To study the molecular basis of host susceptibility vs. resistance on the one hand, and pathogen virulence vs. avirulence on the other, the identification of extracellular compounds such as pathogen effectors that determine the outcome of the interaction is essential. Here, I describe the vacuum infiltration-centrifugation technique, which is an extremely simple and straightforward method to explore one of the most important battlefields of a plant-pathogen interaction; the apoplast.


Asunto(s)
Centrifugación/instrumentación , Hongos/fisiología , Interacciones Huésped-Patógeno , Extractos Vegetales/aislamiento & purificación , Hojas de la Planta/microbiología , Plantas/microbiología , Centrifugación/métodos , Diseño de Equipo , Enfermedades de las Plantas/microbiología , Extractos Vegetales/metabolismo , Hojas de la Planta/metabolismo , Plantas/metabolismo , Vacio
12.
Anesteziol Reanimatol ; (5): 71-6, 2009.
Artículo en Ruso | MEDLINE | ID: mdl-19938720

RESUMEN

The paper gives a brief review of the engineering solutions now applied to the clinical use of a blood reinfusion procedure. It considers simple, transient, and sophisticated (automatic) blood reinfusion methods, their advantages and disadvantages, and the areas of their possible clinical application.


Asunto(s)
Recolección de Muestras de Sangre/instrumentación , Transfusión Sanguínea/instrumentación , Transfusión de Sangre Autóloga/instrumentación , Centrifugación/instrumentación , Diseño de Equipo , Transfusión de Eritrocitos/instrumentación , Humanos
13.
Rapid Commun Mass Spectrom ; 22(18): 2929-36, 2008 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-18729236

RESUMEN

Isotopic measurements of leaf water have provided insights into a range of ecophysiological and biogeochemical processes, but require an extraction step which often constitutes the major analytical bottleneck in large-scale studies. Current standard procedures for leaf water analysis are based on cryogenic vacuum or azeotrophic distillation, and are laborious, require sophisticated distillation lines and the use of toxic materials. We report a rapid technique based on centrifugation/filtration of leaf samples pulverised in their original sampling tubes, using a specifically adapted, simple apparatus. The leaf water extracts produced are suitable for isotopic analysis via pyrolysis gas chromatography isotope ratio mass spectrometry (PYR/GC/IRMS). The new method was validated against cryogenic vacuum distillation and showed an overall accuracy of +/-0.5 per thousand (nine grouped comparisons, n = 110) over a range of 21 per thousand. Effects due to the presence of soluble carbohydrates were near the detection limits for most samples analysed, and these effects could be corrected for (the extracted soluble organics could also be used for isotopic analysis). The extraction time for a routine eight-sample subset was reduced from 4 h (cryogenic distillation) to 45 min, limited only by the size of the centrifuge(s) used. This method provides a rapid, low-cost and reliable alternative to conventional vacuum and other distillation methods that can alleviate current restrictions on ecosystem- and global-scale studies that require high-throughput leaf water isotopic analysis.


Asunto(s)
Centrifugación/instrumentación , Marcaje Isotópico/métodos , Espectrometría de Masas/instrumentación , Extractos Vegetales/aislamiento & purificación , Hojas de la Planta/química , Manejo de Especímenes/instrumentación , Agua/química , Centrifugación/métodos , Diseño de Equipo , Análisis de Falla de Equipo , Manejo de Especímenes/métodos
14.
Interact Cardiovasc Thorac Surg ; 7(5): 759-63, 2008 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-18635585

RESUMEN

This study evaluated the effect of different washing and centrifuge rates of the Cell Saver 5 on the quality of processed autologous blood. Autologous blood was washed with 1000 ml of sterile normal saline at centrifuge speed of 5650 revolutions per minute (rpm) (group I) or 4350 rpm (group II) with different washing pump speeds--500, 800 and 1000 ml/min. Hemoglobin, free hemoglobin, hematocrit, erythrocytes, leukocytes, platelets, and protein were measured before and after processing. The highest values of hemoglobin, hematocrit and erythrocytes were achieved using 800 and 1000 ml/min pump speeds in group I and 500 ml/min speed in group II. Red blood cells concentration was higher in group I. There were no significant changes of free hemoglobin removal within group I. In group II the lowest free hemoglobin was achieved when 1000 ml/min rate was used. Platelets and protein did not depend on wash pump speeds in both groups. Platelet recovery in group I was higher than in group II at all washing pump speeds. Leukocytes were not adequately removed at all pump speeds. The Cell Saver 5 produces optimum results when the high wash pump speeds (800 and 1000 ml/min) and standard centrifuge speed are used.


Asunto(s)
Transfusión de Sangre Autóloga/instrumentación , Puente Cardiopulmonar , Centrifugación/instrumentación , Transfusión de Eritrocitos/instrumentación , Transfusión de Sangre Autóloga/efectos adversos , Transfusión de Sangre Autóloga/normas , Centrifugación/efectos adversos , Centrifugación/normas , Diseño de Equipo , Recuento de Eritrocitos , Transfusión de Eritrocitos/efectos adversos , Transfusión de Eritrocitos/normas , Hematócrito , Hemoglobinas/análisis , Humanos , Recuento de Leucocitos , Recuento de Plaquetas , Estudios Prospectivos , Control de Calidad , Estrés Mecánico
15.
Vestn Khir Im I I Grek ; 167(6): 87-91, 2008.
Artículo en Ruso | MEDLINE | ID: mdl-19241825

RESUMEN

The aim of the investigation was to study effectiveness of washing autoblood by Cell Saver 5 (Haemonetics ) device in using different rates of washing and centrifuging. Autoblood was washed with 1000 ml 0.9% NaCl with different rates (500, 800 and 1000 ml/min) at different rates of centrifuge (5650 r/min and 4350 r/min). It was shown that Haemonetics Cell Saver 5 secured the optimum composition of the end product when using high rates of washing (800 and 1000 ml/min) and standard rate of the centrifuge rotation (5650 r/min).


Asunto(s)
Centrifugación/instrumentación , Transfusión de Eritrocitos/normas , Monitoreo Intraoperatorio/métodos , Transfusión de Sangre Autóloga , Centrifugación/normas , Puente de Arteria Coronaria , Diseño de Equipo , Recuento de Eritrocitos , Eritrocitos/citología , Eritrocitos/metabolismo , Hemoglobinas/análisis , Humanos , Reproducibilidad de los Resultados
16.
Cardiovasc Eng ; 7(1): 39-42, 2007 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-17380386

RESUMEN

According to Earnshaw's Theorem (1839), the passive maglev cannot achieve stable equilibrium and thus an extra coil is needed to make the rotor electrically levitated in a heart pump. The author had developed a permanent maglev centrifugal pump utilizing only passive magnetic bearings, to keep the advantages but to avoid the disadvantages of the electric maglev pumps. The equilibrium stability was achieved by use of so-called "gyro-effect": a rotating body with certain high speed can maintain its rotation stably. This pump consisted of a rotor (driven magnets and an impeller), and a stator with motor coil and pump housing. Two passive magnetic bearings between rotor and stator were devised to counteract the attractive force between the motor coil iron core and the rotor driven magnets. Bench testing with saline demonstrated a levitated rotor under preconditions of higher than 3,250 rpm rotation and more than 1 l/min pumping flow. Rotor levitation was demonstrated by 4 Hall sensors on the stator, with evidence of reduced maximal eccentric distance from 0.15 mm to 0.07 mm. The maximal rotor vibration amplitude was 0.06 mm in a gap of 0.15 mm between rotor and stator. It concluded that Gyro-effect can help passive maglev bearings to achieve stabilization of permanent maglev pump; and that high flow rate indicates good hydraulic property of the pump, which helps also the stability of passive maglev pump.


Asunto(s)
Centrifugación/instrumentación , Diseño Asistido por Computadora , Corazón Auxiliar , Magnetismo/instrumentación , Magnetismo/uso terapéutico , Diseño de Equipo , Análisis de Falla de Equipo
17.
Bioresour Technol ; 98(4): 940-5, 2007 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-16762544

RESUMEN

A pot experiment was conducted on a low-fertility calcareous soil in order to evaluate the effect on ryegrass growth and nutrient uptake of an organic fertiliser obtained by composting "alperujo" and cotton gin waste. Compost, alone and combined with nitrogen fertilisation, was added to the soil at three rates and three harvests were obtained. The compost application enhanced plant growth in the first and third harvest. However, the additional nitrogen fertilisation clearly improved soil productivity due to the scarce availability of this nutrient in the compost. Also, a general increase in the plant contents of phosphorus and potassium in the first two harvests was recorded, whereas treatments with the maximum compost rate showed the highest plant content of copper in the last two harvests. Decreases in calcium in the last two harvests, in magnesium in all of them and in iron and manganese in the last harvest were also observed.


Asunto(s)
Centrifugación/instrumentación , Residuos Industriales , Lolium/metabolismo , Aceites de Plantas/aislamiento & purificación , Lolium/crecimiento & desarrollo , Aceite de Oliva
18.
Artif Organs ; 30(5): 371-6, 2006 May.
Artículo en Inglés | MEDLINE | ID: mdl-16683955

RESUMEN

Centrifugal pumps have been increasingly used in clinical settings. Like roller pumps, centrifugal pumps can cause debris release due to mechanical stress. The objectives of this study were to evaluate in vitro the particle release from a centrifugal pump, Gyro Pump (Japan Medical Materials Co., Osaka, Japan), which is a pivot-bearing supported pump clinically used in Japan, and to identify the released particles. In the clean room Class 10,000, the pump was operated for 24 h at 4000 rpm and 6 L/min in a mock loop filled with lactated Ringer's solution. After 24 h, the sample fluid and a blank were filtered with a 0.45-microm membrane filter for microscopic counting, followed by observation with a scanning electron microscope and element analysis with an X-ray spectrometer. Microscopic countings were 128 +/- 42 in the test samples (n = 10) of the Gyro Pump and 98 +/- 42 in the blank samples (n = 10) (P = 0.12). The oxygen/carbon atomic ratio of the particles in the test samples was 0.32 +/- 0.06, which was similar to the ratio of the particles in the blank sample (0.34 +/- 0.06). The profiles of elements with an X-ray spectrometer showed that the released particles from the Gyro Pump were not derived from the pump materials. In conclusion, an in vitro test system has been established for estimation of particle release from a centrifugal pump. Based upon the results with the system, the Gyro Pump with a pivot-bearing system has little risk to release debris particles even in a severe condition.


Asunto(s)
Corazón Artificial/efectos adversos , Óxido de Aluminio/efectos adversos , Materiales Biocompatibles/efectos adversos , Centrifugación/instrumentación , Diseño de Equipo , Microscopía Electrónica de Rastreo , Tamaño de la Partícula , Polietilenos/efectos adversos
19.
J Pharmacol Toxicol Methods ; 53(3): 186-97, 2006.
Artículo en Inglés | MEDLINE | ID: mdl-16176877

RESUMEN

INTRODUCTION: A novel application of a Ultrafree filter cartridge/centrifugation method was evaluated to determine uptake in canalicular membrane vesicles (CMVs) from SD rats, beagle dogs, cynomolgus monkeys (common safety species in the pharmaceutical industry) and humans to assess biliary transport. METHODS: CMVs prepared from fresh livers of rats, dogs, monkeys and humans (four donors) were characterized for enrichment, basolateral and Golgi contamination and orientation. The presence of MRP2 and p-glycoprotein (P-gp) were confirmed by Western blots. Uptake of [3H]-leukotriene C4 (LTC4) and [3H]-estradiol-17beta-d-glucuronide (E2-Gluc) was determined at a low substrate concentration and/or by kinetic measurements (K(m) and V(max)). Correlation of in vitro data with in vivo findings was achieved by determining the biliary clearance of E2-Gluc in rats after a single i.v. dose and with literature in vivo data for LTC4. RESULTS: CMVs were highly enriched and minimally contaminated based on marker enzyme activities. Uptake clearance among different species varied by approximately ten-fold (rat > dog = human > monkey) for LTC4 and less than two-fold for E2-Gluc. The lower uptake of LTC4 by human than rat CMVs may be attributed to a higher Km value for human than rat CMVs. Uptake of LTC4 or E2-Gluc by human CMVs showed little inter-subject variability (2-5-fold). Differences in in vitro uptake clearance (10-fold) between LTC4 and E2-Gluc in rat CMVs seemed to correlate with differences in their biliary clearance (4-fold) in rats, consistent with LTC4 and E2-Gluc being a high and a low clearance substrate, respectively. DISCUSSION: A novel application of a Ultrafree filter cartridge/centrifugation method was developed to determine uptake in CMVs from different preclinical animal safety species and humans, and may represent a useful approach to study the mechanism of biliary excretion during drug discovery and development.


Asunto(s)
Canalículos Biliares/metabolismo , Hepatocitos/metabolismo , Hígado/citología , Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/genética , Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/metabolismo , Adulto , Animales , Bilis/metabolismo , Canalículos Biliares/enzimología , Transporte Biológico Activo/efectos de los fármacos , Transporte Biológico Activo/fisiología , Membrana Celular/enzimología , Membrana Celular/metabolismo , Centrifugación/instrumentación , Centrifugación/métodos , Perros , Evaluación Preclínica de Medicamentos , Estradiol/análogos & derivados , Estradiol/farmacocinética , Femenino , Hepatocitos/citología , Humanos , Técnicas In Vitro , Leucotrieno C4/farmacocinética , Macaca fascicularis , Masculino , Proteínas de Transporte de Membrana/genética , Proteínas de Transporte de Membrana/metabolismo , Persona de Mediana Edad , Proteína 2 Asociada a Resistencia a Múltiples Medicamentos , Proteínas Asociadas a Resistencia a Múltiples Medicamentos/genética , Proteínas Asociadas a Resistencia a Múltiples Medicamentos/metabolismo , Ratas , Ratas Sprague-Dawley , Especificidad de la Especie , Especificidad por Sustrato
20.
Eur Spine J ; 13 Suppl 1: S102-6, 2004 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-15221571

RESUMEN

A possible strategy to promote the wound-healing cascade in both soft and hard tissues is the preparation of an autologous platelet-rich plasma (PRP) to encourage the release of growth factors from activated platelets. In this process, PRP combines the advantage of an autologous fibrin clot that will aid in hemostasis as well as provide growth factors in high concentrations to the site of a tissue defect. The PRP preparation can be used as a biological enhancer in the healing of fractures and lumbar fusions. The local application of growth factors seems to promote initiation and early maturation of bone formation. Autologous bone or bone substitutes can be added to this mixture to increase the volume of grafting material. A simplified technique utilizing a commercially available separation system (GPS-Gravitational Platelet Separation System) is described. This system provides a less costly alternative to other previously described augmentation techniques and also presents a patient-friendly and operator-safe alternative. Further experimental studies of the actual concentrations of the growth factors in the PRP samples are necessary in order to validate the platelet concentration and growth-factor activation by laboratory evidence. In further prospective clinical trials, the safety and efficacy of PRP, in combination with autologous bone or bone graft substitutes, must be evaluated.


Asunto(s)
Plaquetas/fisiología , Sustancias de Crecimiento/metabolismo , Transfusión de Plaquetas/métodos , Cicatrización de Heridas/fisiología , Pérdida de Sangre Quirúrgica/prevención & control , Transfusión de Sangre Autóloga/métodos , Separación Celular/métodos , Centrifugación/instrumentación , Centrifugación/métodos , Humanos , Activación Plaquetaria/fisiología , Columna Vertebral/cirugía
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