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1.
In this work a disposable, parallel microbioreactor (MBR) suitable for screening in batch or continuous mode is presented. The reactor consists of five parallel microchambers made of poly(dimethylsiloxane) bonded to a glass substrate. A grid structure is engraved on each chamber, allowing subsequent morphology imaging. Measurements are recorded over the entire cultivation period with constant parameters, namely, position and focus in the z-axis. The microdevice may be used for either parallel, uni- or multiparametric screening, and overcomes the drawback of gridless microwell plates which require expensive equipment such as an inverted microscope with an automatic stage. To validate the scalability from laboratory scale to microscale, and thus the cultivation protocol in the MBR, the germination of fungal spores (A. ochraceus) is evaluated for two different key magnitudes (pH and temperature) and compared to the results obtained from conventional laboratory scale systems (flasks and agar plates). Information on germination capacity with regard to interspecies' variability allows for optimization of industrial processes as optimal pH and temperature matched to the mesoscopic cultivation systems. The germination conditions therefore remain unaffected inside the MBR, while providing the following advantages: (i) dramatic reduction of medium consumption, (ii) submerged cultivation with constant oxygen supply, (iii) assured low cost and disposability, and (iv) possibility of a continuous cultivation mode. 相似文献
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Stefanie Demming Gena Peterat Andreu Llobera Hannah Schmolke Alexander Bruns Michael Kohlstedt Ala‘aldeen Al-Halhouli Claus-Peter Klages Rainer Krull Stephanus Büttgenbach 《Biomicrofluidics》2012,6(3)
This paper presents a vertically positioned microfluidic system made of poly(dimethylsiloxane) (PDMS) and glass, which can be applied as a microbubble column (μBC) for biotechnological screening in suspension. In this μBC, microbubbles are produced in a cultivation chamber through an integrated nozzle structure. Thus, homogeneous suspension of biomass is achieved in the cultivation chamber without requiring additional mixing elements. Moreover, blockage due to produced carbon dioxide by the microorganisms—a problem predominant in common, horizontally positioned microbioreactors (MBRs)—is avoided, as the gas bubbles are released by buoyancy at the upper part of the microsystem. The patterned PDMS layer is based on an optimized two-lithographic process. Since the naturally hydrophobic PDMS causes problems for the sufficient production of microbubbles, a method based on polyelectrolyte multilayers is applied in order to allow continuous hydrophilization of the already bonded PDMS-glass-system. The μBC comprises various microelements, including stabilization of temperature, control of continuous bubble formation, and two optical configurations for measurement of optical density with two different sensitivities. In addition, the simple and robust application and handling of the μBC is achieved via a custom-made modular plug-in adapter. To validate the scalability from laboratory scale to microscale, and thus to demonstrate the successful application of the μBC as a screening instrument, a batch cultivation of Saccharomyces cerevisiae is performed in the μBC and compared to shake flask cultivation. Monitoring of the biomass growth in the μBC with the integrated online analytics resulted in a specific growth rate of 0.32 h−1, which is almost identical to the one achieved in the shake flask cultivation (0.31 h−1). Therefore, the validity of the μBC as an alternative screening tool compared to other conventional laboratory scale systems in bioprocess development is proven. In addition, vertically positioned microbioreactors show high potential in comparison to conventional screening tools, since they allow for high density of integrated online analytics and therefore minimize time and cost for screening and guarantee improved control and analysis of cultivation parameters. 相似文献
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Jacobo . Rubio-Arias Luis Andreu Luis Manuel Martínez-Aranda Alejandro Martínez-Rodríguez Pedro Manonelles Domingo J. Ramos-Campo 《运动与健康科学(英文)》2021,10(2):192
BackgroundTo finish an endurance race, athletes perform a vigorous effort that induces the release of cardiac damage markers. There are several factors that can affect the total number of these markers, so the aim of this review was to analyze the effect of endurance running races on cardiac damage markers and to identify the factors that modify the levels of segregation of these cardiac damage markers.MethodsA systematic search of PubMed, Web of Science, and the Cochrane Library databases was performed. This analysis included studies where the acute effects of running races on cardiac damage markers (troponin I and troponin T) were analyzed, assessing the levels of these markers before and after the races.ResultsThe effects of running races on troponin I (mean difference = 0.0381 ng/mL) and troponin T (mean difference = 0.0256 ng/mL) levels were significant. The ages (R2 = 14.4%, p = 0.033) and body mass indexes (R2 = 14.5%, p = 0.045) of the athletes had a significant interaction with troponin I. In addition, gender, mean speed, time to finish the race, and type of race can affect the level of cardiac damage markers.ConclusionEndurance running races induce the release of cardiac-damage markers that remain elevated for at least 24 h after the races. In addition, young male athletes with high body mass indexes who perform races combining long duration and moderate intensity (i.e., marathons) release the highest levels of cardiac damage markers. Physicians should take into consideration these results in the diagnosis and treatment of patients admitted to the hospital days after finishing endurance running races. 相似文献
4.
Santiago Veiga Andreu Roig Miguel A. Gómez-Ruano 《European Journal of Sport Science》2016,16(8):919-926
The main objectives of the present research were (1) to examine the relationships between the distances travelled underwater during the start and turn segments with swimming race performance at the elite level and (2) to determine if the individualised-distance start and turn parameters affect the overall race performance. The race parameters of the 100 and 200?m events during 2013 World Championships were measured by an innovative image-processing system (InThePool® 2.0). Overall, 100?m race times were largely related to faster start velocities in men's breaststroke and freestyle events. Conversely, overall, 200?m race times were largely related to longer starting distances in the women's butterfly events, to longer turn distances in men's and women's backstroke and women's butterfly events and to shorter turn distances in women's freestyle events. Changes on the start or turn velocities could represent moderate time improvements in most of the 100?m events, whereas modifications on the start or turn distances (especially in the last turn) could provide elite swimmers with time improvements of practical importance on the 200?m events. The evaluation of races by individualised-distance parameters should be provided to elite swimmers in order to decide the most appropriate race segment configuration for each event. 相似文献
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Miquel Llobera 《Cultura y Educación》2013,25(7-8):91-98
El autor reivindica el papel didáctico del discurso en el aula. Desde su punto de vista, en los últimos años, se ha enfatizado en demasía la presentación de materiales didácticos «auténticos» en detrimento de considerar como «auténtico» el propio discurso producido en el aula. De hecho, el autor considera que, más allá de ser considerado como input comprensible, el discurso producido en el aula ha tenido una relevancia poco importante y, por eso, en el marco de la construcción de un discurso significativo en la relación profesor-alumno como base del progreso docente, el papel didáctico del discurso en el aula pasa a ocupar un lugar principal. 相似文献
7.
Santiago Veiga Andreu Roig 《Sports biomechanics / International Society of Biomechanics in Sports》2017,16(1):34-44
In the present research, we examined the effect of the starting and turning performances on the subsequent swimming parameters by (1) comparing the starting and turning velocities with the swimming parameters on the emersion and mid-pool segments and (2) by relating the individual behaviour of swimmers during the start and turns with subsequent behaviour on each swimming lap. One hundred and twelve 100 m performances on the FINA 2013 World Swimming Championships were analysed by an image-processing system (InThePool 2.0®). At the point of the start emersion, the swimming parameters of the 100-m elite swimmers were substantially greater than the mid-pool parameters, except on the breaststroke races. On the other hand, no diminution in the swimming parameters was observed between the turn emersion and the mid-pool swimming, except on the butterfly and backstroke male races. Changes on the surface swimming kinematics were not generally related to the starting or turning parameters, although male swimmers who develop faster starts seem to achieve faster velocities at emersion. Race analysts should be aware of a transfer of momentum when swimmers emerge from underwater with implications on the subsequent swimming kinematics, especially for male swimmers who employ underwater undulatory techniques. 相似文献
8.
Andreu Mas-Colell 《Journal of Cultural Economics》1999,23(1-2):87-93
This article considers the specificity of cultural goods, services, and artifacts in the context of international trade theory. The analysis discusses possible justifications for import or export restrictions on cultural goods. 相似文献
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Tertiary Education and Management - 相似文献
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Hubert Korzilius Andreu van Hooft Brigitte Planken Christa Hendrix 《Int J Intercult Relat》2011,35(5):540-553
The relationship between personality dimensions, measured with the Multicultural Personality Questionnaire (MPQ), and foreign language mastery were studied in a Dutch-based multinational company in the agricultural sector. In a survey, differences were studied between internal and external stakeholders to determine whether MPQ dimensions and language mastery allow us to discriminate between them. The internal stakeholders were divided into international and non-international employees; external stakeholders were the business contacts of the international employees (clients and business partners based or working abroad). The international employees were found to be more open-minded and flexible than the non-international employees, and the former group was found to be more emotionally stable than the group of business contacts. On average, the international employees reported speaking one foreign language more than both other groups. Also, the number of foreign languages correlated with the multicultural personality dimensions open-mindedness and emotional stability. It is concluded that emotional stability, open-mindedness, and the number of spoken foreign languages are to some extent predictive of differences between the various stakeholders distinguished in this sample. 相似文献