Journal articles on the topic 'Duration of load (DOL) study'
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Wu, Qiongyao, Liangliang Huo, Enchun Zhu, Shuang Niu, and Huajie Wang. "An Investigation of the Duration of Load of Structural Timber and the Clear Wood." Forests 12, no. 9 (August 25, 2021): 1148. http://dx.doi.org/10.3390/f12091148.
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In this study, DOL of structural timber and the clear wood and DOL of modulus of elasticity of wood were investigated. The dimension lumber of Spruce-Pine-Fir of Grade No. 2 and Grade No. 3 and the small clear specimens of the same species of the dimension lumber were used to conduct the short-term and the long-term bending test. The short-term strength distributions of the dimension lumber and the small clear specimens were obtained. The long-term tests were conducted under constant environmental conditions for 18 months. The sample matching technique was used to estimate the short-term strength of the specimens that underwent long-term tests. It was found out that there is virtually no difference in DOL between different grades or quality of lumber and no difference between structural timber and clear wood, and DOL obtained from the test of this study is more in agreement with Wood’s curve. A threshold stress ratio of about 0.55, loaded above which the wood began to experience strength loss, was revealed from the test. Making use of the threshold ratio concept, the DOL of wood can be obtained not only from failed specimens under load in the process of the long-term loading, but also from the ramp loading test of the specimens that survived the long-term test. Sustained load also poses DOL on the modulus of elasticity of wood, though to less degree than DOL of strength of wood.
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Luo, Xiangya, Xiangqian Luo, Haiqing Ren, Shuangbao Zhang, and Yong Zhong. "The Long-Term Mechanical Properties of BS Perpendicular to the Grain." Polymers 15, no. 1 (December 28, 2022): 128. http://dx.doi.org/10.3390/polym15010128.
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As a modern bamboo composite with good mechanical properties, bamboo scrimber (BS) has achieved prominence in the sustainable architecture field. When used as a structural material, it is inevitably under continual tension perpendicular to the grain, therefore its mechanical response under long-term loading is significant for structural design. In this study, tensile tests were conducted on BS under short-term and long-term loads perpendicular to the grain. The duration of load (DOL) effect on BS perpendicular to grain and its creep effect were analyzed. Compared with BS parallel to the grain, the DOL effect on BS perpendicular to the grain was less severe, and the capacity for creep resistance was weaker. The threshold stress ratio and relative creep strain of BS perpendicular to the grain were 0.40 and 0.87, respectively. It was found that the DOL models and the viscoelastic model accurately predicted the DOL factor and creep strain. This study provides a scientific reference for the safe lifetime service of BS in practical engineering.
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Cockram, Michael S., Ketan Jung Dulal, Radi A. Mohamed, and Crawford W. Revie. "Risk factors for bruising and mortality of broilers during manual handling, module loading, transport, and lairage." Canadian Journal of Animal Science 99, no. 1 (March 1, 2019): 50–65. http://dx.doi.org/10.1139/cjas-2018-0032.
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Multiple factors can affect the risk of bruising and mortality of broilers during loading, transport, and lairage. The risk factors affecting the percentages of broilers in each load that were “dead-on-arrival” (DOA) or bruised were studied from records provided by a processing plant, by undertaking direct observations during on-farm loading and then carrying out multivariable analyses. Selected loads between 2014 and 2015 from seven producers were included in the study. The median DOA per load was 0.13% (Q1 = 0.06, Q3 = 0.25, n = 212), the median total duration from loading to unloading was 8.6 h, and the external temperature ranged from −22 to 22 °C. Although it was not possible to adequately characterise thermal conditions within each load, the analysis indicated that the main risk factors for increased mortality were in spring and winter, an increased duration between loading and end of lairage, and a period of feed withdrawal before loading longer than 6 h. The risk of mortality increased with the weight of the birds and with an increase in rearing mortality. No relationships were found between the manner in which the broilers were handled and the percentages of DOAs or bruised birds.
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Nakamura, Noboru, Shiro Aratake, Yasuo Iijima, and Kazumi Horie. "Proposal of Test Method for Duration of Load Effect (DOL) and Calculation of DOL Factor." Mokuzai Gakkaishi 56, no. 5 (2010): 326–32. http://dx.doi.org/10.2488/jwrs.56.326.
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Gianni, L., L. Viganò, A. Locatelli, G. Capri, A. Giani, E. Tarenzi, and G. Bonadonna. "Human pharmacokinetic characterization and in vitro study of the interaction between doxorubicin and paclitaxel in patients with breast cancer." Journal of Clinical Oncology 15, no. 5 (May 1997): 1906–15. http://dx.doi.org/10.1200/jco.1997.15.5.1906.
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PURPOSE We performed a pharmacologic investigation of paclitaxel (PTX) infused over 3 hours and bolus doxorubicin (DOX) to assess the role of sequence, interval between drugs, and duration of doxorubicin infusion on paclitaxel and anthracycline plasma disposition. We also explored possible mechanisms of pharmacokinetic interference involving the physiologic role of the multidrug resistance phenotype in anthracycline and taxane biliary excretion. PATIENTS AND METHODS Pharmacokinetics was performed in 80 cycles and 36 women with previously untreated metastatic breast cancer. PTX, DOX, and their metabolites 6 alpha-hydroxyl-PTX (6 alpha OH-PTX) and doxorubicinol (DOL) were measured by high-pressure liquid chromatography (HPLC). Human breast cancer MCF-7 wild-type (WT) and resistant (TH) cell lines were cultured in whole human plasma to study anthracycline retention after treatment with different combinations of PTX, Cremophor EL (CEL) (PEG35 castor oil; BASF, Parsippany, NJ), and DOX. RESULTS Pharmacokinetic interference between PTX and DOX was responsible for nonlinearity of DOX plasma disposition and increased concentrations of DOX and DOL. These effects were PTX dose-dependent, DOX concentration-dependent, and likely a result of interference at the level of liver elimination. In view of the physiologic role of P-glycoproteins (P-gp) in xenobiotic biliary excretion, retention of DOX was assessed in MCF-7 WT and MCF-7 TH cells. Intracellular was significantly higher in MCF-7 WT than MCF-7 TH (P < .05). However, concomitant exposure to DOX, PTX, and CEL caused similar DOX retention in both MCF-7 WT and TH cells. CONCLUSION PTX, as clinically formulated in CEL, is responsible for a nonlinear disposition of DOX and DOL. Nonlinearity is PTX- and DOX-dependent, and possibly caused by competition for biliary excretion of taxanes and anthracyclines mediated by P-gp. Nonlinearity indicates that even minor modifications of dose and infusion duration of DOX and PTX may lead to unpredictable pharmacodynamic consequences. The postulated role of P-gp suggests that CEL is clinically active, and advises caution in designing combinations of PTX with other drugs that are substrate for P-gp.
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Andrade, Ana Denise, Mário Simim, Witalo Kassiano, José Manuel Palao, Karla De Jesus, Nycaelle Maia, Cláudio Assumpção, and Alexandre Igor Araripe Medeiros. "Do differences between the training load perceived by elite beach volleyball players and that planned by coaches affect neuromuscular function? (¿Las diferencias entre la carga de entrenamiento percibida por los jugadores de voleibol de playa de élite y." Retos, no. 38 (April 15, 2020): 632–36. http://dx.doi.org/10.47197/retos.v38i38.77625.
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Summary. This study aimed to verify the differences between the training load planned by coaches and that perceived by Beach Volleyball (BV) players and observe the effects on athletes’ neuromuscular function. Three female BV players and well-known coaches participated in the research and were accompanied for three training weeks in the preseason phase. Rating of perceived exertion (RPE) was collected through the 0-10 scale during a previous training session. Strength, physical fitness and tactical-technical training have been assessed with coaches and athletes’ responses 30 minutes after the end of the session. RPE Session was calculated by the product between the training duration in minutes and RPE, to estimate Internal Training Load (ITL). Neuromuscular function was assessed through Countermovement Jump (CMJ). To verify differences between coaches and athletes’ responses and vertical jump performance were used either the magnitude of differences and clinical inference. Athletes experienced lower RPE and ITL as planned by coaches in the first week of training. CMJ increased substantially from the first to the third week (with likely differences (93/03/04), standardized difference = 1.60 and 90% confidence intervals = 0.00; 3.21). We suggest that training load planned by coaches similar to that perceived by athletes have a concomitant improvement with neuromuscular performance.Resumen. Este estudio tuvo como objetivo verificar las diferencias entre la carga de entrenamiento planificada por los entrenadores y la percibida por los jugadores de voleibol de playa (VP) y observar los efectos sobre la función neuromuscular de los atletas. Tres jugadoras de VP y entrenadores conocidos participaron en la investigación y fueron acompañadas durante tres semanas de entrenamiento en la fase de pretemporada. El valor nominal del esfuerzo percibido (NEP) se recolectó a través de la escala 0-10 durante una sesión de entrenamiento anterior. La fuerza, la forma física y el entrenamiento táctico-técnico se evaluaron con las respuestas de los entrenadores y atletas 30 minutos después del final de la sesión. El producto calculó la sesión de NEP entre la duración del entrenamiento en minutos y el NEP, para estimar la carga interna de entrenamiento (CIE). La función neuromuscular se evaluó mediante salto contramovimiento (SCM). Para verificar las diferencias entre los entrenadores y las respuestas de los atletas y el rendimiento del salto vertical, se utilizó la magnitud de las diferencias y la inferencia clínica. Los atletas experimentaron menos NEP e CIE que fueron planificados por los entrenadores en la primera semana de entrenamiento. SCM aumentó sustancialmente de la primera a la tercera semana (con diferencias probables (93/03/04), diferencia estandarizada = 1.60 e intervalos de confianza del 90% = 0.00; 3.21). Sugerimos que la carga de entrenamiento planificada por entrenadores similar a la percibida por los atletas tenga una mejora concomitante con el rendimiento neuromuscular.
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Raya-González, Javier, Pedro Gómez Piqueras, and Javier Sánchez-Sánchez. "Aplicación de un programa de fuerza con carga excéntrica en la readaptación de una lesión de ligamento lateral interno de la rodilla. Estudio de caso (Effect of an eccentric load resistance training program on the rehabilitation of medial collateral liga." Retos, no. 33 (September 16, 2017): 157–61. http://dx.doi.org/10.47197/retos.v0i33.55911.
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El objetivo del presente estudio fue analizar el efecto de un programa de entrenamiento de fuerza con carga excéntrica basado en el ejercicio squat (½ squat y squat lateral) ejecutado en un dispositivo de inercia rotacional, sobre la potencia de la musculatura del tren inferior de un jugador de fútbol durante la readaptación de una lesión del ligamento lateral interno (LLI) de la rodilla. Métodos: Durante 4 semanas (3 sesiones semanales) el futbolista llevó a cabo el programa de entrenamiento de fuerza con carga excéntrica propuesto en ambas extremidades. Antes, durante y después del proceso de intervención se valoró la potencia del tren inferior de manera bilateral y unilateral, y se obtuvieron datos relativos a la potencia media, potencia pico, trabajo y duración de la repetición, tanto en fase concéntrica como excéntrica. Resultados: Se obtuvieron mejoras significativas (p≤.05) en la potencia media y pico (bilateral y unilateral) tanto en la fase concéntrica como excéntrica. Además se redujeron las asimetrías en todas las variables analizadas relativas a la potencia. Conclusiones: La aplicación de un programa de fuerza ejecutado en un dispositivo de inercia rotacional durante el proceso de recuperación funcional produce un incremento de la potencia muscular del tren inferior y disminuye la asimetría provocada por la lesión deportiva, que se refleja en la disminución del periodo de recuperación.Abstract. The aim of this study was to analyse the effect of an eccentric-load training program based on squat exercises (½ squat and lateral squat) on the lower-body power of a football player during the rehabilitation process of a medial collateral ligament injury (MCL). Methods: During 4 weeks (3 sessions a week) the soccer player followed the eccentric-load training program proposed on both legs. Before, during, and after the intervention, lower-body power was evaluated bilaterally and unilaterally, and data was obtained on the mean power, peak power, work, and duration, in both concentric and eccentric phases. Results: Significant improvements (p ≤.05) in mean and maximal power (bilateral and unilateral) were obtained in both concentric and eccentric phases. Asymmetries related to power have also been reduced. Conclusions: the application of an eccentric-overload training program during the functional recovery process results in an increase in the lower-body power and reduces the asymmetry caused by a sports injury, which is reflected in the decrease in the recovery period.
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Gea, Susana B., and P. D. Chacón. "Evaluación de la acción del fuego en una estructura de hormigón armado mediante XRD, SEM y Espectroscopía infrarroja." Revista ALCONPAT 3, no. 1 (January 30, 2013): 29–38. http://dx.doi.org/10.21041/ra.v3i1.41.
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RESUMENEl Monumento a los Héroes de la Independencia situado en Humahuaca (norte de Argentina) es una obra inaugurada en 1950 que representa magníficamente las razas autóctonas y europeas que conforman la identidad nacional. Las esculturas de bronce de 40t se encuentran sustentadas por una estructura de hormigón armado, la cual incluye instalaciones adecuadas para vivienda de un cuidador. El subsuelo de esta vivienda sufrió la acción de un incendio cuya carga y tiempo de duración se desconocen. A fin de evaluar los efectos en el hormigón producidos por el fuego, fueron tomadas muestras de un sector de la estructura que luego fueron analizadas por diversas técnicas: difracción por rayos X, microscopía electrónica de barrido y espectroscopia infrarroja. El estudio permitió inferir la temperatura a la que estuvieron sometidas las muestras analizadas y la profundidad alcanzada por el daño. Se proponen los pasos a seguir para evaluar la totalidad de la estructura.Palabras Clave: hormigón armado; fuego; microscopía electrónica; difracción por rayos X; espectroscopia infrarroja.ABSTRACTThe Monument to the Independence Heroes in Humahuaca (northern Argentina) was built in 1950 and represents magnificently the native and European people which shape the national identity. A reinforced concrete structure bears the bronze sculptures of 40tons and includes a dwelling for the monument keeper. The basement of this dwelling underwent a fire whose load and duration are unknown. A few samples from a sector of the structure were taken in order to assess the effects that fire produced in the concrete. They were analyzed by different techniques: X-ray diffraction, scanning electron microscopy and infrared spectroscopy. The study allowed to infer the temperature experimented by the analyzed samples and the depth of the damage. The following steps to assess the whole structure are proposed.Keywords: reinforced concrete; fire; electronic microscopy; X-ray diffraction; infrared spectroscopy.
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Lee, Eun Jeong, Tae Geun Kim, and Kyoung-sik Choi. "A Study of the Load Allocation using Watershed Model and Load Duration Curve in TMDL." KSCE Journal of Civil Engineering 22, no. 9 (January 12, 2018): 3222–32. http://dx.doi.org/10.1007/s12205-018-0910-0.
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Cheng, Laixiu, Liang Shi, Ling Yi, and Weizhuo Zhao. "Study on Mechanical Properties and Constitutive Relationship of Concrete Corroded by Hydrochloric Acid under Cyclic Load." Sustainability 14, no. 22 (November 8, 2022): 14692. http://dx.doi.org/10.3390/su142214692.
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Most of the existing studies on acid corrosion of concrete have focused on the mechanical behavior of concrete structures under monotonic load or without load. To investigate the mechanical properties of in-service concrete components under cyclic load in an acid corrosion environment, six groups of concrete prism specimens with different acid corrosion degrees (corrosion duration) were designed and prepared by the accelerated corrosion test method. The monotonic and cyclic axial compression load tests on these specimens were conducted to investigate the effects of corrosion degree on the mechanical properties of concrete specimens. The experimental results indicated that hydrochloric acid corrosion has obvious effects on the failure characteristics and mechanical properties of concrete. The surface of corroded concrete was easier to crack and spall under load, and the concrete spalling area enlarged as the acid corrosion duration increased. The compressive capacity of concrete specimens reduced rapidly with the increase in corrosion duration. The stress–strain envelope curves for concrete with different corrosion duration under cyclic load were essentially similar to that of concrete under monotonic load. The degradation rate of the descending section for the stress–strain curves of corroded concrete under cyclic load was much larger than that under the monotonic load due to the accumulation of internal damage in concrete. The peak strain and ultimate strain of corroded concrete increased significantly with the increase in corrosion duration and enhanced by 55.7% and 77.9%, respectively, compared with the uncorroded concrete, whereas the peak stress and elastic modulus rapidly decreased and reduced by 53.3% and 74.1%, respectively. Moreover, based on the strength degradation depth, the concept of effective bearing cross-sectional area ratio was proposed to characterize the corrosion degree of concrete, and the correction coefficient of descending section for the effective bearing cross-sectional area ratio was introduced to establish the constitutive model of corroded concrete under cyclic load, and the results calculated by this model matched well with the experimental values. The research in this paper can provide the experimental and theoretical basis for seismic life cycle and fatigue redesign of concrete structures in acid corrosion environments or coastal areas.
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Alidjinou, Enagnon, Julien Poissy, Mahdi Ouafi, Morgan Caplan, Ilyes Benhalima, Julien Goutay, Claire Tinez, et al. "Spatial and Temporal Virus Load Dynamics of SARS-CoV-2: A Single-Center Cohort Study." Diagnostics 11, no. 3 (March 3, 2021): 427. http://dx.doi.org/10.3390/diagnostics11030427.
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The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused an ongoing pandemic. Reverse transcription polymerase chain reaction (RT-PCR) is the gold standard for the detection of SARS-CoV-2 and has been applied to different specimen types. Understanding the virus load and virus detection frequency in different specimen types is important to improve diagnosis and estimate the duration of potential infectivity. We conducted a retrospective single-center cohort study on hospitalized and outpatients with SARS-CoV-2 infection. We analyzed the frequency of virus detection, virus load, and duration of the virus excretion in upper and lower respiratory specimens as well as stool and plasma. We found that the frequency of SARS-CoV-2 detection, the virus load, and duration of virus excretion was higher in lower respiratory tract (LRT) than in upper respiratory tract (URT) specimens. The duration of virus excretion was longer in patients requiring intensive care unit (ICU) admission. In conclusion, LRT specimens are the most appropriate specimen type for the detection and follow-up of SARS-CoV-2 infection. Duration of virus excretion is longer in severe cases of SARS-CoV-2 infection.
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Soloviev, Soloviev, A. N. Kozlov, A. I. Timirbaeva, and A. K. Olkhovatsky. "Study of the duration of operation of teat rubber milking machines." Sel'skohozjajstvennaja tehnika: obsluzhivanie i remont (Agricultural Machinery: Service and Repair), no. 5 (May 1, 2020): 35–40. http://dx.doi.org/10.33920/sel-10-2005-06.
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Hannesdóttir, Ásta, Albert Meseguer Urbán, Filip Spasov, and Antoine Larvol. "Optimum gust detection by nacelle-based lidar: A study on the Vestas V52." Journal of Physics: Conference Series 2265, no. 2 (May 1, 2022): 022072. http://dx.doi.org/10.1088/1742-6596/2265/2/022072.
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Abstract In this study we use lidar measurements from a four-beam nacelle mounted lidar, together with wind turbine load measurements, to analyse events that cause extreme blade flapwise loading on the Vestas V52 at Risø campus. We define a simple gust detection algorithm that is based on fitting a linear model to the line of sight velocity measurements in order to detect changes and fluctuations in the incoming wind field. The detection algorithm is run on a whole year of measurements and we perform an iterative parameter sweep using different values for two parameters of the gust detection method. These parameters are a slope threshold and slope duration of the linear fit. The blade loads that are associated with the detected gusts are analysed to find the optimum settings of the gust detection parameters. It was found that the most extreme observed blade load was detected for a range of parameters and by setting the slope threshold to 1.2 m/s2 and duration to 4 s, we could achieve the highest average load within the parameter range. On the other hand, the highest average blade load was found by setting the slope threshold to 1.4 m/s2 and duration to 8.5 s, though the most extreme load was not detected with those settings. The gust detection method shows potential to be used as an add-on solution to a traditional wind turbine controller to mitigate extreme loading during operation.
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Zhou, Ming, Xin Tang Wang, and Wan Zhen Wang. "Experimental Study of Mechanical Behavior of Concrete Filled Steel Tubular Short Columns after Fire." Advanced Materials Research 168-170 (December 2010): 674–78. http://dx.doi.org/10.4028/www.scientific.net/amr.168-170.674.
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Mechanical behavior and bearing capacity of ordinary concrete filled steel tubular short column (NCSSC) and ceramsite concrete filled steel tubular short column (CCSSC) subjected to fire load are experimentally investigated. Effect of the parameters, such as the maximum value of fire temperatures, fire duration on the strength and ductility of the two types of specimens were especially discussed. The test results show that both of the specimens of NCSSC and CCSSC after fire have higher bearing capacity and better ductility, there was no descent segment in load-displacement curves of the most specimens after the fire load was subjected, and even the case that bearing load increased again after descent segment arose. It was concluded that the maximum response temperature of specimens and fire duration time has great effect on the axial bearing capacity of concrete-filled steel tubular short columns subjected to fire, and there is a turning point of temperature for the influence.
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Xu, Ming Hai, Liang Liu, and Si Qin Chang. "Study on Intake Performance of Camless Engine." Applied Mechanics and Materials 525 (February 2014): 198–202. http://dx.doi.org/10.4028/www.scientific.net/amm.525.198.
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Electromagnetically-driven valve (EMVA) represents one of the most important developments in camless engines, which can realize unthrottled load control. An AVL-BOOST simulation model for a camless engine equipped with EMVA is built up and validated by the experimental results. The performance of the camless engine is simulated, and the intake performance and pumping loss are determined. The results of research show that the mass flow of the camless engine can be controlled by changing the intake valve opening duration, so that the load is controlled. They also show that the pumping loss can be reduced and the fuel economy can be improved during part load.
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Larsson, Gustaf, Per Johan Gustafsson, Erik Serrano, and Roberto Crocetti. "Duration of load behaviour of a glued shear plate dowel joint." European Journal of Wood and Wood Products 78, no. 1 (November 5, 2019): 5–15. http://dx.doi.org/10.1007/s00107-019-01474-z.
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Abstract An experimental study on the duration of load effects in a glued shear plate dowel joint was conducted. The joint design features a single large diameter dowel for load transfers between members, via external steel plates, which are bonded to the timber with a low stiffness bond line. Due to the low bond line stiffness, the timber element is subjected to a close to uniform shear stress distribution over the bond area. The study comprises a total of 80 test specimens loaded in shear, both parallel and perpendicular to the grain, at three load levels in the range of 50–80% of the short-term failure load. All specimens failed within approximately 110 days in outdoor sheltered conditions during which time deformations were recorded for one specimen of each type and load level. The study found a significantly larger influence of duration of load for this dominant shear action than what is reported in the literature for bending tests. The method of ranked stress was used to determine a suggested reduction factor kmod for the shear plate dowel joint to 0.10 and 0.30 for parallel and perpendicular loading, respectively. This is a rough estimate based upon a 50-year extrapolation of 4-month data. Thus, it must be concluded that the studied shear plate dowel joint is not efficient in terms of long-duration loads in outdoor sheltered climate, and that further studies are needed in order to verify the use in other climates. It is also evident in this study that there is a lack of knowledge and empirical evidence on the duration of load effects in timber for shear loading.
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Algamluoli, Ammar Falah, and Nizar Hadi Abbas. "Speed controller design for three-phase induction motor based on dynamic adjustment grasshopper optimization algorithm." International Journal of Electrical and Computer Engineering (IJECE) 11, no. 2 (April 1, 2021): 1143. http://dx.doi.org/10.11591/ijece.v11i2.pp1143-1157.
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Three-phase induction motor (TIM) is widely used in industrial application like paper mills, water treatment and sewage plants in the urban area. In these applications, the speed of TIM is very important that should be not varying with applied load torque. In this study, direct on line (DOL) motor starting without controller is modelled to evaluate the motor response when connected directly to main supply. Conventional PI controller for stator direct current and stator quadrature current of induction motor are designed as an inner loop controller as well as a second conventional PI controller is designed in the outer loop for controlling the TIM speed. Proposed combined PI-lead (CPIL) controllers for inner and outer loops are designed to improve the overall performance of the TIM as compared with the conventional controller. In this paper, dynamic adjustment grasshopper optimization algorithm (DAGOA) is proposed for tuning the proposed controller of the system. Numerical results based on well-selected test function demonstrate that DAGOA has a better performance in terms of speed of convergence, solution accuracy and reliability than SGOA. The study results revealed that the currents and speed of TIM system using CPIL-DAGOA are faster than system using conventional PI and CPIL controllers tuned by SGOA. Moreover, the speed controller of TIM system with CPIL controlling scheme based on DAGOA reached the steady state faster than others when applied load torque.
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Romero-Caballero, Alejandro, and Miguel Ángel Campos-Vázquez. "Relación entre indicadores de carga interna en un juego reducido 3x3 en jóvenes futbolistas (Relationship between internal load indicators in a 3-a-side small-sided game in young soccer players)." Retos, no. 37 (July 31, 2019): 152–59. http://dx.doi.org/10.47197/retos.v37i37.71130.
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El objetivo de esta investigación fue comprobar si existía relación entre el esfuerzo percibido por los jugadores (RPE Borg-10) y el porcentaje de frecuencia cardiaca de reserva (%FCres), como métodos para monitorizar la carga interna durante juegos en espacios reducidos (SSG) en futbolistas de categoría alevín, infantil y cadete. 36 jóvenes futbolistas del mismo club, pertenecientes a tres categorías diferentes, participaron en este estudio: alevín (media ± dt): (11,76 ± 0,31 años), infantil (12,78 ± 0,37) y cadete (15,25 ± 0,53). Todos realizaron dos SSG 3x3 con una duración de 4 series de 4 minutos, con descansos de 3 minutos entre estas. La frecuencia cardiaca (FC) estuvo constantemente registrada y el esfuerzo percibido de cada participante (RPE Borg-10) fue anotado después de cada una de las series de ambos SSG. Se realizó un ANOVA de medidas repetidas para comparar los valores medios inter-serie de las diferentes variables y un ANOVA de un factor para comparar los valores medios de cada variable durante el SSG completo entre las diferentes categorías. También se utilizó el análisis de correlación de Pearson para comprobar la relación entre el %FCres y la RPE en diferentes momentos y en función de las categorías. De estos análisis se deriva una relación moderada y estadísticamente significativa (r= .41; p<0.05) entre la RPE de los futbolistas y su % FCres durante los SSG. Estos resultados confirman que la RPE es una herramienta práctica a la hora de evaluar la carga interna durante SSG en las primeras etapas formativas en futbol.Abstract. The main purpose of this work was to verify if there was a relation between players’ perceived effort (RPE Borg-10) and the percentage of reserve heart rate (%HRres) as methods to monitor the internal load during small sided games (SSG) in U-16, U-14 and U-12 soccer players. A group of 36 young soccer players from the same club, divided into three categories: U-12 (mean ± ds: 11.76 ± 0.31 years), U-14 (12.78 ± 0.37) and U-16 (15.25 ± 0.53), participated in this study. All of them performed two SSG with a duration of 4 sets of 4 minutes, with a 3-minute rest period between them. Heart rate (HR) was constantly recorded and each participant’s perceived effort (RPE Borg-10) was recorded after each of the series of both SSG. Repeated-measure ANOVA was performed to compare mean inter-series values of the different variables, whereas one-way ANOVA was run to compare mean values of each variable during the complete SSG between the different categories. Pearson correlation analysis was also used to verify the relationship between %HRres and RPE at different times and according to the categories. From these analyses, a moderate and statistically significant relationship (r= .41; p<0.05) was derived between soccer players’ RPE and %HRres during SSG. These results confirm that RPE is a practical tool when evaluating SSG internal load in the first formative stages in soccer.
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Prinster, A., M. Quarantelli, R. Lanzillo, G. Orefice, G. Vacca, B. Carotenuto, B. Alfano, A. Brunetti, V. Brescia Morra, and M. Salvatore. "A voxel-based morphometry study of disease severity correlates in relapsing— remitting multiple sclerosis." Multiple Sclerosis Journal 16, no. 1 (December 22, 2009): 45–54. http://dx.doi.org/10.1177/1352458509351896.
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Previous studies have shown a preferential loss of grey matter in fronto-temporal regions in patients with multiple sclerosis. Studies of correlates of disease severity are more controversial, because some studies have suggested an association between sensorimotor cortex atrophy and Expanded Disability Status Scale score, while others did not find such a correlation. The objective of this study was to assess the correlation of regional loss of grey matter and white matter with indexes of clinical and radiological severity in relapsing—remitting multiple sclerosis, including the Expanded Disability Status Scale and lesion load. Correlations between Expanded Disability Status Scale, lesion load and disease duration were assessed in 128 patients with relapsing—remitting multiple sclerosis (Expanded Disability Status Scale range 1.0—6.0) using optimized voxel-based morphometry. Bilateral loss of grey matter in sensorimotor cortices was correlated with Expanded Disability Status Scale, and tissue loss also involved adjacent white matter, extending along pyramidal tracts to the brainstem. Increasing lesion load was correlated with loss of deep grey matter and white matter. No specific region of grey matter or white matter showed a significant correlation with disease duration. These findings support the hypothesis that motor neuron involvement plays a major role in the progression of physical disability. Lesion load accrual affects mainly highly interconnected subcortical structures, while disease duration has a less significant impact on brain atrophy, probably owing to the inter-subject heterogeneity of the clinical course of the disease.
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Ahmed Shah, Zahoor, Abdul Shakoor, and Hammad-Ur Rehman Bhatti. "Remdesivir for Treating Non-Hospitalized Patients with COVID-19." Pakistan Journal of Medical and Health Sciences 16, no. 2 (February 26, 2022): 156–57. http://dx.doi.org/10.53350/pjmhs22162156.
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Aim: To examine the effect of remdesivir for treating non-hospitalized patients with COVID-19. Study design: Retrospective study Place and duration of study: Department of Medicine, Bolan Medical College, Quetta from 1st April 2021 to 30th September 2021. Methodology: One hundred patients were enrolled and divided into group A and group B within the age of 24-70 years. Group A was receiving remdesivir while group B is not receiving remdesivir. The clinical variables, BMI, comorbidities, duration of disease severity and viral load were determined. RT-PCR was conducted to determine viral load. Results: The mean age of study participants was 50±15 years with greater number of males. Diabetes was the major comorbidity. The time duration was decreased in group A upto 5 days and 8 days in group B. The viral load was decreased by mean value 6.32±1.76 to 6.2±1.78 in group B then group A respectively. Conclusion: Remdesivir is effective in COVID-19 treatment. Keywords: Remdesivir, COVID-19, Viral load
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Egan, Pamela C., Emmanuelle Belanger, Orestis A. Panagiotou, Vinay B. Rao, Aryeh Pelcovits, Thomas W. LeBlanc, and Adam J. Olszewski. "Comparison of End-of-Life Care Quality Outcomes and Indicators of Palliative Needs between Medicare Beneficiaries with Solid and Hematologic Malignancies." Blood 136, Supplement 1 (November 5, 2020): 11. http://dx.doi.org/10.1182/blood-2020-143078.
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Background: Patients (pts) with hematologic malignancies (HM) are thought to have suboptimal hospice utilization and receive more aggressive end of life (EOL) care than those with solid tumors (ST), including high rates of EOL chemotherapy use, ICU admissions, and inpatient deaths (Egan, Blood Adv, 2020). Barriers to equitable EOL care outcomes for pts with HM may include difficulty identifying the "terminal phase" of disease, the potential for curative stem cell transplant that lingers even after failure of multiple therapies (Odejide, JCO, 2016), and specificity of palliative needs in HM, like transfusion dependence (Leblanc, Blood, 2018), that are not met by the current hospice benefit. However, direct comparison of EOL outcomes between HM and ST in a population-based setting has not been conducted. Our objective was to compare EOL care quality measures, hospice utilization, and indicators of palliative needs between Medicare beneficiaries with HM and ST. Methods: From the linked SEER Medicare database (covering ~30% of the US population), we identified beneficiaries with common ST (breast, prostate, lung, and colorectal cancer) and HM (leukemia, myeloma, lymphoma, myelodysplastic syndrome [MDS], and myeloproliferative neoplasms [MPN]) who died between 2011-2015, and whose cause of death was cancer. We ascertained claims-based indicators of EOL care quality: hospice use before death, duration of hospice length of stay (LOS), death in an acute care hospital, receipt of (oral or parenteral) chemotherapy in the last 14 days of life (DOL), ICU admission in the last 30 DOL, Medicare spending, and inpatient days in the last 30 DOL. We also explored indicators of palliative needs: opioid use, transfusion use, and number of physician office visits in the last 30 DOL. We compared binary outcomes in multivariable robust Poisson (reporting adjusted relative risk, adj RR), counts in negative binomial, and costs in log-gamma models, reporting estimates with 95% confidence intervals (CI). Models were adjusted for age, sex, race, marital status, Medicaid co-insurance (indicator of low socio-economic status), prevalent poverty, comorbidity index, performance status indicator, calendar year, and survival from diagnosis. Results: Characteristics of the 18,185 patients with HM and 59,352 with ST are listed in Table. HM pts were, on average, older, and more likely to be male and married. HM pts were less likely than ST pts to enroll on hospice (58% vs 67%, adjusted RR 0.85,CI 0.84-0.86), had a shorter hospice LOS (median 9 vs 14 days, adj means ratio RR 0.81, CI 0.79-0.83), and were more likely to spend < 3 days on hospice (adj RR 1.29, CI 1.24-1.35) (see Figure). HM pts were more likely to die in an acute care setting (32% vs 23%, adj RR 1.4, CI 1.36-1.44), have an ICU admission in the last 30 DOL (39% vs 30%, adj RR 1.32, CI 1.29-1.35), and receive chemotherapy in the last 14 DOL (12% vs 5%, adj RR 2.73, CI 2.55-2.93). Median Medicare spending in the last 30 DOL was higher in HM than in ST (17.8k vs 11.9k, adj means ratio 1.52, CI 1.49-1.56), as was the median number of inpatient days (4 vs 2, adj means ratio 1.55, CI 1.52-1.59). The results were consistent when examined by specific subtypes of HM and ST. Pts with HM were less likely to use opioids at the EOL (adj RR 0.81, 95% CI, 0.79-0.84), but had more transfusions (adj RR 4.34, 95% CI, 4.11-4.58) and more physician office visits (adj RR 1.11, 95% CI, 1.09-1.14). Furthermore, trends in EOL care quality indicators differed between HM and ST. While the use of hospice services increased for both populations, the hospice LOS has steadily lengthened over time in ST (from median 10 days in 2011 to 14 days in 2015, P<.001), but it did not change significantly in HM (P=.077). Discussion: To our knowledge, this is the first population-based study demonstrating that, adjusting for socio-demographic characteristics and baseline health status, pts with HM have inferior EOL care quality outcomes than those with ST. These disparities are consistent across all established EOL care quality outcomes and across all histologies, supporting the notion of a fundamental difference between EOL care in HM and ST. Furthermore, our data challenge the assumption that HM pts do not have significant palliative care needs; rather, their needs may differ from those of ST patients, and may be less easily met by the current hospice benefit (as other literature suggests). Novel care models are needed to improve EOL care for pts with HM. Disclosures Panagiotou: International Consulting Associates, Inc: Other: personal fees from International Consulting Associates, Inc. outside the scope of the submitted work. LeBlanc:AstraZeneca: Research Funding; Agios, AbbVie, and Bristol Myers Squibb/Celgene: Speakers Bureau; UpToDate: Patents & Royalties; American Cancer Society, BMS, Duke University, NINR/NIH, Jazz Pharmaceuticals, Seattle Genetics: Research Funding; AbbVie, Agios, Amgen, AstraZeneca, CareVive, BMS/Celgene, Daiichi-Sankyo, Flatiron, Helsinn, Heron, Otsuka, Medtronic, Pfizer, Seattle Genetics, Welvie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees. Olszewski:Adaptive Biotechnologies: Research Funding; Spectrum Pharmaceuticals: Research Funding; Genentech, Inc.: Research Funding; TG Therapeutics: Research Funding.
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Costa, Facundo, Andrés Santiago Parodi Feye, and Carlos Magallanes. "Efectos del entrenamiento de sobrecarga tradicional vs CrossFit sobre distintas expresiones de la fuerza (Effects of traditional strength training vs CrossFit on different expressions of strength)." Retos 42 (March 23, 2021): 182–88. http://dx.doi.org/10.47197/retos.v42i0.86132.
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El desarrollo de la fuerza es relevante tanto para el rendimiento como para la salud. El propósito del presente estudio fue determinar los efectos del CrossFit en comparación con entrenamiento tradicional sobre distintas manifestaciones de la fuerza. Catorce adultos entrenados de ambos sexos fueron divididos aleatoriamente en dos grupos para realizar 8 semanas de entrenamiento: un grupo (CF; edad: 24.9 ± 1.6 años) realizó CrossFit y el otro grupo (ET; edad: 28.7 ± 4.6 años) realizó entrenamiento de fuerza tradicional. La carga de ambos fue equiparada con relación a la duración de la parte central de las sesiones. Todos los sujetos fueron evaluados con tests de fuerza máxima (Back Squat, Bench Press y Dead Lift), fuerza resistencia (Squat y Push-ups) y fuerza explosiva (Squat Jump y Abalakov) pre y post intervención. Se verificaron mejoras en ambos grupos en todas las variables analizadas (p < 0,05), pero no se hallaron diferencias entre grupos como consecuencia de los distintos programas de entrenamiento. Se concluye que ambos programas de entrenamiento son similarmente efectivas para desarrollar la fuerza máxima, la fuerza explosiva y la fuerza resistencia en adultos entrenados.
Abstract: Muscular strength development in its different expressions forms is relevant for both sport performance and health. The purpose of the present study was to determine the effects of CrossFit training in comparison with traditional resistance training on different expressions of strength. Fourteen adults of both sexes, with strength training experience, were randomly divided into two groups to perform 8 weeks of training: one group (CF; age: 24.9 ± 1.6yrs) performed CrossFit and the other group (ET; age: 28.7 ± 4.6yrs) performed traditional strength training. The training load of both programs was equated in relation to the duration of the main part of the sessions. All subjects were tested for maximal strength (Back Squat, Bench Press and Dead Lift), endurance strength (Squat and Push-ups) and explosive strength (Squat Jump and Abalakov) before and after the intervention. Significant improvements were verified in both groups post intervention for all the variables analyzed (p <0.05), but no significant differences were found between groups as a consequence of the different training programs. It is concluded that both training modalities are similarly effective in developing maximal strength, explosive strength and endurance strength in trained adults.
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Featherston, C. A., J. Mortimer, Mark J. Eaton, Richard L. Burguete, and Rhiannon Johns. "The Dynamic Buckling of Stiffened Panels –A Study Using High Speed Digital Image Correlation." Applied Mechanics and Materials 24-25 (June 2010): 331–36. http://dx.doi.org/10.4028/www.scientific.net/amm.24-25.331.
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For a structure subjected to an intermediate velocity impact in which the duration of loading is in the order of milliseconds and in excess of the period of it’s first free vibration mode there is a relationship between impact duration and buckling load. Although this relationship results in higher buckling loads for shorter duration impacts, the precise nature of the correlation depends on a number of other factors, one of which is geometry. Since the design of many lightweight structures subject to dynamic loading in this intermediate range is based on the use of a static buckling load to which a load factor is then applied, it is essential that this factor accurately represents the relationship between the two and takes of account of any variations. Failure to do so will at least result in an over designed structure and at worst in catastrophic failure. A series of finite element analyses (FEA) have been performed in order to determine the relationship between dynamic and static buckling loads for a range of stiffened panels with differing radii of curvature. This paper describes preliminary tests performed to determine the feasibility of using high speed digital image correlation (DIC) to study such an impact and hence provide validation of the earlier FEA analyses. These are performed on a longitudinally stiffened panel subject to uniaxial compression, clamped within a rig designed to provide built-in end conditions and allow motion of one end in the direction of loading only. The specimen is tested using an accelerated drop test rig. Impact load is monitored throughout using a load cell. Full field displacement contours are obtained using a high speed DIC system. Results are presented which demonstrate deflection contours during and after impact enabling the path of the shock wave through the specimens to be determined. An initial comparison is then made the FEA results.
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Xu, Xun, Yashan Zhu, Kejing Tian, Tingcan Lin, and Yunyu Li. "Study on an Integral Algorithm of Load Identification Based on Displacement Response." Sensors 21, no. 19 (September 25, 2021): 6403. http://dx.doi.org/10.3390/s21196403.
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Load identification is a very important and challenging indirect load measurement method because load identification is an inverse problem solution with ill-conditioned characteristics. A new method of load identification is proposed here, in which a virtual function was introduced to establish integral structure equations of motion, and partial integration was applied to reduce the response types in the equations. The effects of loading duration, the type of basis function, and the number of basis function expansion items on the calculation efficiency and the accuracy of load identification were comprehensively taken into account. Numerical simulation and experimental results showed that our algorithm could not only effectively identify periodic and random loads, but there was also a trade-off between the calculation efficiency and identification accuracy. Additionally, our algorithm can improve the ill-conditionedness of the solution of load identification equations, has better robustness to noise, and has high computational efficiency.
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S. S., Nurud, Abdullah I., Saari M, NorMariah A., and Rafee B. "Fire load survey in multi-storey wholesale premise – a case study." International Journal of Engineering Technology and Sciences 5, no. 1 (June 4, 2018): 53–59. http://dx.doi.org/10.15282/ijets.v5i1.2824.
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A combustible material is one of fire hazard where the amount of combustible materials or fire load could affect the heat release and fire severity in enclosure. The fire severity in the context of fire load is related to intensity and duration of fire in enclosure. Fire load survey is conducted in this study to estimate the amount of combustible materials in wholesale premise since it become threat to life safety and property loss. The determinations of fire load in 3-storey wholesale premise in Kuantan city is conducted by using combination fire load survey method; weighing and inventory method. Result from fire load survey can help to determine the sufficient requirements of fire suppression in premise as well as fire fighters intervention strategy. An extension of this study, the data could be used as an important input to design fire for deterministic analysis in fire risk assessment to quantify the level of fire risk towards life, property and environment.
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Tang, Xiu Jian, Xin Li Tian, Jian Quan Wang, Ya Tao Mao, and F. Q. Li. "Study on Acoustic Emission Signatures during the Process of Edge Chipping for Engineering Ceramics." Materials Science Forum 697-698 (September 2011): 93–96. http://dx.doi.org/10.4028/www.scientific.net/msf.697-698.93.
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The developments of edge chipping for engineering ceramics are analyzed. An edge chipping experiment under static load is adopted to study the fracture process of edge chipping. The results show that the fracture processes of edge chipping under different edge distances are similar, which can be divided into four stages based on load-displacement curve. There is obviously Kaiser Effect during the fracture processes of edge chipping. Counts, average frequency, RMS, duration, amplitude and inverse calculation can be used to describe the process of edge chipping for engineering ceramics. Amplitude, duration and average frequency become highly active on the eve of fracture, which can be regard as the omens of edge chipping and used to predict the fracture of edge chipping.
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Felayati, Frengki Mohamad, Dwisetiono, Hadi Prasutiyon, and Betty Ariani. "Study on Natural Gas/Diesel Dual-fuel Engine Energy Ratio: Effect of Natural Gas Injection Parameters." IOP Conference Series: Earth and Environmental Science 1081, no. 1 (September 1, 2022): 012038. http://dx.doi.org/10.1088/1755-1315/1081/1/012038.
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Abstract Natural gas has been a promising demand for several years in Indonesia as a fuel for a diesel engine by converted into a natural gas/diesel dual-fuel engine. However, determining the energy ratio of the diesel and natural gas fuel is important due to the engine performance and emissions which affect the engine safety operation. This study presents the method to determine the natural gas and diesel fuel energy ratio on intake port natural gas injection mode through experiment. A direct injection diesel engine is converted to a natural gas/diesel dual-fuel engine by injecting natural gas into the intake port. The diesel injection parameters are unmodified for the experiment; besides the natural gas injection variations are studied to determine the energy ratio. Moreover, the engine is tested for low to high load conditions. However, natural gas injection duration, pressure, and injection timing variation affect the fuel energy ratio and indicated thermal efficiency (ITE). At low load, the optimum fuel energy ratio and ITE are achieved at a long injection duration (10 ms) and with advanced injection timing. Moreover, at high load, the optimum fuel energy ratio and ITE is achieved at high natural gas injection duration (12 ms), high injection pressure (3 bar), and advancing the injection timing.
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Wang, Xin Tang, Zhi Guo Xie, Ming Zhou, and Jie Yin. "Experimental Study of Mechanical Behavior of Ceramsite Concrete Filled Steel Tubular Columns Subjected to Fire Load." Advanced Materials Research 243-249 (May 2011): 1228–32. http://dx.doi.org/10.4028/www.scientific.net/amr.243-249.1228.
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Mechanical behavior of a set of ordinary concrete filled steel tubular short column (note as NCSSC) and ceramsite concrete filled steel tubular short column (note as CCSSC) subjected to fire load are experimentally investigated. Effect of the parameters, such as the maximum value of fire temperatures, fire duration on the strength and ductility of the two types of specimens were especially discussed. The test results show that both of the specimens of NCSSC and CCSSC have higher post-fire bearing capacity and better ductility, there was no descent segment in post-fire load-displacement curves of the most specimens subjected to fire load. It was concluded that the maximum response temperature of specimens and fire duration time has great effect on the axial bearing capacity of concrete-filled steel tubular short columns subjected to fire. The maximum longitudinal strain of specimens of CCSSC is less than the corresponding value of the longitudinal strain of NCSSC.
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Brink, Michel S., Wouter G. P. Frencken, Geir Jordet, and Koen A. P. M. Lemmink. "Coaches’ and Players’ Perceptions of Training Dose: Not a Perfect Match." International Journal of Sports Physiology and Performance 9, no. 3 (May 2014): 497–502. http://dx.doi.org/10.1123/ijspp.2013-0009.
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Purpose:The aim of the current study was to investigate and compare coaches’ and players’ perceptions of training dose for a full competitive season.Methods:Session rating of perceived exertion (RPE), duration, and training load (session RPE × duration) of 33 professional soccer players (height 178.2 ± 6.6 cm, weight 70.5 ± 6.4 kg, percentage body fat 12.2 ± 1.6) from an under-19 and under-17 (U17) squad were compared with the planned periodization of their professional coaches. Before training, coaches filled in the session rating of intended exertion (RIE) and duration (min) for each player. Players rated session RPE and training duration after each training session.Results:Players perceived their intensity and training load (2446 sessions in total) as significantly harder than what was intended by their coaches (P < .0001). The correlations between coaches’ and players’ intensity (r = .24), duration (r = .49), and load (r = .41) were weak (P < .0001). Furthermore, for coach-intended easy and intermediate training days, players reported higher intensity and training load (P < .0001). For hard days as intended by the coach, players reported lower intensity, duration, and training load (P < .0001). Finally, first-year players from the U17 squad perceived training sessions as harder than second-year players (P < .0001).Conclusion:The results indicate that young elite soccer players perceive training as harder than what was intended by the coach. These differences could lead to maladaptation to training. Monitoring of the planned and perceived training load of coaches and players may optimize performance and prevent players from overtraining.
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Chikov, A. E., A. N. Pavlova, A. V. Naumov, and D. S. Medvedev. "Duration of functional stability to non-specific aerobic load in wrestlers." Sports medicine: research and practice 10, no. 4 (March 17, 2021): 85–90. http://dx.doi.org/10.47529/2223-2524.2020.4.10.
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Objective: study the duration of establishment of functional stability to non-specific stress in wrestlers.Materials and Methods. Nineteen athletes in martial arts, mid-age 23 ± 3 years of age, participated in the study. The qualification level of the subjects ranged from first sport grade to Master of Sport. A series of sports training was organized within 4 weeks. Each train consisted of a smooth-running load of 40 minutes at a speed corresponding to the anaerobic exchange threshold (AET). The indicators of the duration of reaching the AET level by heart rate (HR), the power of the low frequency and high frequency component of the spectrum were analyzed.Results. The effect of urgent adaptation, in the form of an extension of the duration the heart rate on the anaerobic threshold level from 29 to 32 mines and the increase in the regulation of vegetative nervous system by increasing the total power of the spectrum observed on the third day of the training cycle. From the third to ninth days of the study, fatigue occurs, as can be seen from the lowering of the anaerobic threshold time to 21 minutes, as well as the lowering of the high-frequency part of the vegetative nervous system regulatory spectrum. The emergency adaptation ends by 9 days of observation, after four high-intensity exercises, which manifests itself in stabilizing the regulation of the heart rate, vegetative nervous system goes from a reflex level to a lower one — a humeral metabolic level. The time to reach the HR in the aerobic threshold will stabilize at 21–23 minutes.Conclusions. Functional stability to the non-specific aerobic load in the wrestlers emerged by the twentyseventh day of the study after ten highly intensive aerobic exercises, which confirmed by the results of the time dynamics of the tine of HR in aerobic threshold and analysis of spectrum results of HRV.
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Serrano, Ligia de Oliveira, Alisson Carraro Borges, Fernando Falco Pruski, and Marília Carvalho de Melo. "A New Approach to Use Load Duration Curves to Evaluate Water Quality: A Study in the Doce River Basin, Brazil." Water 12, no. 3 (March 14, 2020): 811. http://dx.doi.org/10.3390/w12030811.
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Although water availability depends both on qualitative and quantitative aspects, most studies focus only on one of these. Therefore, the goal here is to relate water quality and quantity with the construction of Load Duration Curves (LDC) and to estimate E. coli load patterns in different flow conditions, seasons, and positions of two sub-basins of the Doce watershed (Brazil): Piracicaba and Piranga. A novel methodology is proposed in which the Burr XII distribution is adjusted to the LDC to compare all observed loads to their respective Total Maximum Daily Load (TMDL), allowing the estimation of the relative difference (RD) between these. Higher values of RD were observed for low flows for the Piracicaba basin, more urbanized, where point sources of pollution are the primary concern, reaching up to 99% of needed load reduction. In the Piranga basin, more agricultural, there was a broader RD variation, from 9% to 97% load reduction needed, which is an evidence of point sources of pollution combined with non-point sources. The new methodology can be used to estimate the load reduction of any pollutant and can be used by environmental agencies to identify effective practices to minimize and control pollution in different locations of the basins.
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Liao, Yan Fen, Yan Xu, and Xiao Qian Ma. "Study of Destabilization Mechanism of Concrete Component Based on Catastrophe Theory." Advanced Materials Research 413 (December 2011): 499–506. http://dx.doi.org/10.4028/www.scientific.net/amr.413.499.
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A simplified mechanical model in view of concrete component stability problem on fire was established. Assuming the temperature of fire and load as control variables, and material strain (or intensity) as state variables, destabilization mechanism of concrete component under high temperatures was carried out with the application of cusp catastrophic model. And the nonlinear mutation characteristics and failure mechanism of concrete component on fire were investigated. The results indicate that system's catastrophe characteristic is determined by fire duration, temperature, load capacity and load characteristics. When K=-F'(u)/km>1, component destructs in the form of ductility failure, and when K<1, component destructs in the form of brittle failure. As the temperature rises, the caper value increases if the spring stiffness is defined.
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Malone, James J., Arne Jaspers, Werner Helsen, Brenda Merks, Wouter G. P. Frencken, and Michel S. Brink. "Seasonal Training Load and Wellness Monitoring in a Professional Soccer Goalkeeper." International Journal of Sports Physiology and Performance 13, no. 5 (May 1, 2018): 672–75. http://dx.doi.org/10.1123/ijspp.2017-0472.
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The purpose of this investigation was to (1) quantify the training load practices of a professional soccer goalkeeper and (2) investigate the relationship between the training load observed and the subsequent self-reported wellness response. One male goalkeeper playing for a team in the top league of the Netherlands participated in this case study. Training load data were collected across a full season using a global positioning system device and session-RPE (rating of perceived exertion). Data were assessed in relation to the number of days to a match (MD− and MD+). In addition, self-reported wellness response was assessed using a questionnaire. Duration, total distance, average speed, PlayerLoad™, and load (derived from session-RPE) were highest on MD. The lowest values for duration, total distance, and PlayerLoad™ were observed on MD−1 and MD+1. Total wellness scores were highest on MD and MD−3 and were lowest on MD+1 and MD−4. Small to moderate correlations between training load measures (duration, total distance covered, high deceleration efforts, and load) and the self-reported wellness response scores were found. This exploratory case study provides novel data about the physical load undertaken by a goalkeeper during 1 competitive season. The data suggest that there are small to moderate relationships between training load indicators and self-reported wellness response. This weak relation indicates that the association is not meaningful. This may be due to the lack of position-specific training load parameters that practitioners can currently measure in the applied context.
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Kramar, V. G. "DETERMINATION OF LOAD DURATION CURVE (ROSSANDER GRAPH) FOR THE REGIONS OF UKRAINE." Industrial Heat Engineering 40, no. 4 (December 14, 2018): 41–49. http://dx.doi.org/10.31472/ihe.4.2018.06.
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The purpose of this work is to determine the duration of the ambient air temperatures of different gradations during heating periods in different regions of Ukraine, based on the climatic data for 2005-2018 and the construction of load duration curves for the respective regions. The load duration curve (Rossander graph) is used to determine the number of maximum thermal load using hours, as well as in cases where the thermal load is provided by several sources - to determine their level of participation in the total annual heat energy production. It is important for a more accurate technical and economic evaluation of implementation results for some thermal energy sources. The climatic data of meteorological stations located in the regional centers of Ukraine and the capital of Autonomous Republic of Crimea, or as close as possible to them, were used for the study. The climatic data of heating periods from the autumn of 2005 to 2018 were considered. As the result of study, the duration of various degrees of ambient air temperature in the heating period was determined for all the regional centers of Ukraine. Taking into account the significant climatic differences in the regions of Ukraine, the results were analyzed separately for two groups of regions, for which, according to averaged data, load duration curves were determined. The examples of using of obtained results for calculations are given. On the basis of obtained data regarding duration of ambient temperatures higher than +8°C during the heating season, the energy saving potential of implementation of weather-dependent regulation of heat energy production for heating purposes in different regions was theoretically estimated, which is, on average, 8.4% for the first temperature zone (north, center) and 13% for the second zone (south).
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Sipavičienė, Saulė, Audronė Dumčienė, Irina Ramanauskienė, and Albertas Skurvydas. "Effect of Single Physical Load of Different Duration and Intensity on Cognitive Function." Medicina 48, no. 4 (May 25, 2012): 31. http://dx.doi.org/10.3390/medicina48040031.
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The aim of this study was to determine the effect of a single physical load of different duration and intensity on cognitive function. Material and Methods. The study population comprised 90 male soldiers. The subjects were randomly divided into two groups: experimental (n=60) and control group (n=30). The soldiers in the experimental group undertook 3 specific loads of different types, durations, and intensities. Attention concentration and tapping tests were carried out, and the reaction time was measured. Results. After the physical load, the soldiers in the experimental group performed the attention concentration test faster, the number of committed mistakes decreased, and the rate of processing information increased as compared to the corresponding values before physical load (all P<0.05). However, the indices of fatigue, such as the tapping test score and reaction time, in the experimental group were found to be worse than before physical loads (P<0.05). No significant changes were observed in the control group of soldiers. Conclusion. Despite fatigue, a single physical load of different duration and intensity improved the cognitive function.
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Birnbaumer, Philipp, Lena Weiner, Tanja Handl, Gerhard Tschakert, and Peter Hofmann. "Effects of Different Durations at Fixed Intensity Exercise on Internal Load and Recovery—A Feasibility Pilot Study on Duration as an Independent Variable for Exercise Prescription." Journal of Functional Morphology and Kinesiology 7, no. 3 (July 21, 2022): 54. http://dx.doi.org/10.3390/jfmk7030054.
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Duration is a rarely investigated marker of exercise prescription. The aim of this study was to test the feasibility of the methodological approach, assessing effects of different duration constant-load exercise (CLE) on physiological responses (internal load) and recovery kinetics. Seven subjects performed an incremental exercise (IE) test, one maximal duration CLE at 77.6 ± 4.8% V˙O2max, and CLE’s at 20%, 40%, and 70% of maximum duration. Heart rate (HR), blood lactate (La), and glucose (Glu) concentrations were measured. Before, 4, 24, and 48 h after CLE’s, submaximal IE tests were performed. HR variability (HRV) was assessed in orthostatic tests (OT). Rating of perceived exertion (RPE) was obtained during all tests. CLE’s were performed at 182 ± 27 W. HRpeak, Lapeak, V˙Epeak, and RPEpeak were significantly higher in CLE’s with longer duration. No significant differences were found between CLE’s for recovery kinetics for HR, La, and Glu in the submaximal IE and for HRV or OT. Despite no significant differences, recovery kinetics were found as expected, indicating the feasibility of the applied methods. Maximum tests and recovery tests closer to CLE’s termination are suggested to better display recovery kinetics. These findings are a first step to prescription of exercise by both intensity and duration on an individual basis.
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Kahale, Ajay K. "Study of Wear Behaviour of Titanium Grade 2 Using Application of Taguchi Method." International Journal for Research in Applied Science and Engineering Technology 9, no. 12 (December 31, 2021): 2214–19. http://dx.doi.org/10.22214/ijraset.2021.39707.
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Abstract: Titanium Grade 2 sample piece were subjected to wear on standard linear reciprocating tribometer machine for dry sliding condition in the constant temperature. Taguchi method were use to predict the wear rate against parameter such as Load, Frequency, and time. Signal to noise ratio and ANOVA were used study the impact of these three parameter on the wear rate. In conclusion, the major statistical factor affecting wear rate is load, followed by frequency and duration. Multiple linear regression equations are developed. Keywords: Titanium grade 2, wear rate, Tribometer, ANOVA
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Xu, Qiwei, Jianshu Huang, Yue Han, Yun Yang, and Lingyan Luo. "A Study on Electric Vehicles Participating in the Load Regulation of Urban Complexes." Energies 13, no. 11 (June 8, 2020): 2939. http://dx.doi.org/10.3390/en13112939.
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Urban complex (UC) is the main place of citizens’ life and work. The construction of an UC often needs to expand the capacity of the power equipment. This paper proposes to use electric vehicles (EVs) in an UC to reduce the power load of the UC during peak periods, so that lower capacity power equipment can be used to reduce the construction costs of the UC and the transformation of electrical facilities. In order to find the relationship between parking and power load in the UC, the UC is decomposed into different functional areas for research. Then, we build a parking information database for clustering and calculation. Divide the load peak into adjustment intervals of equal duration. The EVs parked in the UC for each regulation interval (RI) are grouped according to parking characteristics. Establish an objective function with the minimum load variance during peak hours. The discharge capacity of each group in each RI is obtained and distributed to each EV to realize peak load reduction of UC. Finally, the results of case analysis show that the strategy can reduce the peak load effectively thus save the cost of UC construction.
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Lechien, Jerome R., Pierre Cabaraux, Carlos M. Chiesa-Estomba, Mohamad Khalife, Jan Plzak, Stéphane Hans, Delphine Martiny, et al. "Psychophysical Olfactory Tests and Detection of COVID-19 in Patients With Sudden Onset Olfactory Dysfunction: A Prospective Study." Ear, Nose & Throat Journal 99, no. 9 (May 29, 2020): 579–83. http://dx.doi.org/10.1177/0145561320929169.
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Objective: To investigate the coronavirus disease 2019 (COVID-19) status of patients with initial sudden olfactory anosmia (ISOA) through nasopharyngeal swabs for reverse transcription–polymerase chain reaction (RT-PCR) analysis and to explore their olfactory dysfunctions with psychophysical olfactory evaluation. Methods: A total of 78 ISOA patients were recruited from April 6, 2020, to April 10, 2020, through a public call of University of Mons (Mons, Belgium). Patients benefited from nasopharyngeal swabs and fulfilled the patient-reported outcome questionnaire. Among them, 46 patients performed psychophysical olfactory evaluation using olfactory identification testing. Based on the duration of the ISOA, 2 groups of patients were compared: patients with olfactory dysfunction duration ≤12 days (group 1) and those with duration >12 days (group 2). Results: In group 1, 42 patients (87.5%) had a positive viral load determined by RT-PCR and 6 patients (12.5%) were negative. In group 2, 7 patients (23%) had a positive viral load and 23 patients (77%) were negative. The psychophysical olfactory evaluation reported that anosmia and hyposmia occurred in 24 (52%) and 11 (24%) patients, respectively. Eleven patients were normosmic. The viral load was significantly higher in patients of group 1 compared with those of group 2. Conclusions: Coronavirus disease 2019 was detected in a high proportion of ISOA patients, especially over the first 12 days of olfactory dysfunction. Anosmia is an important symptom to consider in the detection of COVID-19 infection.
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Henkens, Ivo R., Koen T. B. Mouchaers, Anton Vonk-Noordegraaf, Anco Boonstra, Cees A. Swenne, Arie C. Maan, Sum-Che Man, et al. "Improved ECG detection of presence and severity of right ventricular pressure load validated with cardiac magnetic resonance imaging." American Journal of Physiology-Heart and Circulatory Physiology 294, no. 5 (May 2008): H2150—H2157. http://dx.doi.org/10.1152/ajpheart.01312.2007.
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The study aimed to assess whether the 12-lead ECG-derived ventricular gradient, a vectorial representation of ventricular action potential duration heterogeneity directed toward the area of shortest action potential duration, can improve ECG diagnosis of chronic right ventricular (RV) pressure load. ECGs from 72 pulmonary arterial hypertension patients recorded <30 days before onset of therapy were compared with ECGs from matched healthy control subjects ( n = 144). Conventional ECG criteria for increased RV pressure load were compared with the ventricular gradient. In 38 patients a cardiac magnetic resonance (CMR) study had been performed within 24 h of the ECG. By multivariable analysis, combined use of conventional ECG parameters (rsr′ or rsR′ in V1, R/S > 1 with R > 0.5 mV in V1, and QRS axis >90°) had a sensitivity of 89% and a specificity of 93% for presence of chronic RV pressure load. However, the ventricular gradient not only had a higher diagnostic accuracy for chronic RV pressure load by receiver operating characteristic analysis [areas under the curve (AUC) = 0.993, SE 0.004 vs. AUC = 0.945, SE 0.021, P < 0.05], but also discriminated between mild-to-moderate and severe RV pressure load. CMR identified an inverse relation between the ventricular gradient and RV mass, and a trend toward a similar relation with RV volume. In conclusion, chronically increased RV pressure load is electrocardiographically reflected by an altered ventricular gradient associated with RV remodeling-related changes in ventricular action potential duration heterogeneity. The use of the ventricular gradient allows ECG detection of even mildly increased RV pressure load.
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Shcherba, A. А., N. І. Suprunovska, and M. O. Lomko. "INFLUENCE OF THE CAPACITANCE OF THE CAPACITOR OF THE DISCHARGE CIRCUIT OF SEMI-CONDUCTOR ELECTRIC DISCHARGE INSTALLATIONS ON THEIR OUTPUT CURRENTS OF LIMITED DURATION." Praci Institutu elektrodinamiki Nacionalanoi akademii nauk Ukraini 2021, no. 58 (May 19, 2021): 5–13. http://dx.doi.org/10.15407/publishing2021.58.005.
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Based on the analysis of transient processes of oscillatory and aperiodic discharges of the storage capacitor of the electric discharge installation to the load, it is proved that an increase in its capacity always causes an increase in the value of the discharge current corresponding to a fixed duration of the discharge, less than the duration of reaching the maximum value of the discharge current. For the capacities of the discharge capacitor varied over a wide range, the change in the value of the discharge current in the load during its forced interruption at a certain time was studied. Based on this study, we proposed a method for increasing the rate of rising of impulse currents in the load, which consists in choosing a discharge capacitor with a larger capacity compared with a capacity sufficient to implement the desired technological mode, and forced interrupting the current in the load at a certain point in time, which corresponds to a certain fixed duration discharge (less than the duration of reaching the maximum value of the discharge current when the capacitor capacity is sufficient to implement the required technological mode). The forced limitation of the discharge duration is carried out by a fully controlled semiconductor switch. This method can be used as the basis for the production of spark erosion nano-sized powders of metals and alloys. Ref. 15, fig. 3, table .
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Kirk, Christopher, Carl Langan-Evans, David R. Clark, and James P. Morton. "Quantification of training load distribution in mixed martial arts athletes: A lack of periodisation and load management." PLOS ONE 16, no. 5 (May 10, 2021): e0251266. http://dx.doi.org/10.1371/journal.pone.0251266.
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The aim of this study was to quantify typical training load and periodisation practices of MMA athletes. MMA competitors (n = 14; age = 22.4 ± 4.4 years; body mass = 71.3 ± 7.7 kg; stature = 171 ±9.9 cm) were observed during training for 8 consecutive weeks without intervention. Seven athletes were training for competitive bouts whilst the remaining 7 were not. Daily training duration, intensity (RPE), load (sRPE and segRPE), fatigue (short questionnaire of fatigue) and body region soreness (CR10 scale) were recorded. Using Bayesian analyses (BF10≥3), data demonstrate that training duration (weekly mean range = 3.9–5.3 hours), sRPE (weekly mean range = 1,287–1,791 AU), strain (weekly mean range = 1,143–1,819 AU), monotony (weekly mean range = 0.63–0.83 AU), fatigue (weekly mean range = 16–20 AU) and soreness did not change within or between weeks. Between weeks monotony (2.3 ± 0.7 AU) supported little variance in weekly training load. There were no differences in any variable between participants who competed and those who did not with the except of the final week before the bout, where an abrupt step taper occurred leading to no between group differences in fatigue. Training intensity distribution corresponding to high, moderate and low was 20, 33 and 47%, respectively. Striking drills accounted for the largest portion of weekly training time (20–32%), with MMA sparring the least (2–7%). Only striking sparring and wrestling sparring displayed statistical weekly differences in duration or load. Athletes reported MMA sparring and wrestling sparring as high intensity (RPE≥7), BJJ sparring, striking sparring and wrestling drills as moderate intensity (RPE 5–6), and striking drills and BJJ drills as low intensity (RPE≤4). We conclude that periodisation of training load was largely absent in this cohort of MMA athletes, as is the case within and between weekly microcycles.
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Jia, Meng Meng, Li Xiang, Mao Sheng Ding, Jian Ding, Yun Ting Song, and Jian Cheng Zhang. "Study on the Coordination of Load Shedding and Under-Frequency Load Shedding (UFLS) in Small Weak Receiving Power System with Wind Power Penetration." Applied Mechanics and Materials 392 (September 2013): 557–62. http://dx.doi.org/10.4028/www.scientific.net/amm.392.557.
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Frequency influencing factors in small weak receiving power grid with wind power penetration during the disturbance of power shortage are analyzed in this paper, such as wind power penetration rate, wind turbine types, inertia control loop and wind power fluctuation. Based on the influencing factors above, in the light of the phenomenon of large dive depth and long duration of the frequency first swing after fault, the coordination scheme of load shedding and under-frequency load shedding based on the simulation system is proposed: load shedding time and load shedding ratio coordination scheme. Simulation results verify the correctness of the theoretical analysis and the rationality and feasibility of the coordination scheme proposed.
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Puddy, A., and M. Younes. "Effect of slowly increasing elastic load on breathing in conscious humans." Journal of Applied Physiology 70, no. 3 (March 1, 1991): 1277–83. http://dx.doi.org/10.1152/jappl.1991.70.3.1277.
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Because the detection of added loads is a function of the step change in load relative to background level of load (Weber's law), we reasoned that detection may be delayed if the load is increased in very small steps over a protracted period. This would permit the study of subliminal load responses over a greater range than would otherwise be possible. In 13 healthy males, an external elastic load (delta E) was added in very small steps (load increased every few seconds) such that delta E increased from zero to 6.0 cmH2O/l in 18 min. Each subject underwent a control study in which an identical protocol was followed but no load was added. Five subjects sensed the load after a variable period of load application. Their results were discarded. In the remaining eight subjects, there was no perception of increased load throughout the 18 min. By comparison with the control studies in the same subjects, there was a progressive reduction in tidal volume and breath duration with loading. To assess the response to an increase in load associated with perception, in five of the eight "nonsensers" the load was suddenly doubled (delta E = 6 cmH2O/l) at the end of the 18 min of progressive nonsensed loading. This evoked perception in all subjects and was associated with highly variable responses in tidal volume and breath duration. We conclude that tachypnea associated with elastic loading in conscious humans is a reflex response that is facilitated by consciousness but does not require perception.
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He, Kang, and Yu Chen. "Experimental Investigation on Stability of Circular Steel Tubular Stub Columns at Elevated Temperatures Under Axial Compression." International Journal of Structural Stability and Dynamics 19, no. 06 (June 2019): 1950063. http://dx.doi.org/10.1142/s0219455419500639.
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This paper studies the structural stability of circular steel tubular stub columns at elevated temperatures under axial compression. Fifty-one specimens are subjected to high-temperature treatment and axial compression. The variables of the specimen are temperature, wall thickness of steel tube and duration of high temperature. The displacement–load curve, strain–load curve, ultimate load, axial compressive stiffness and failure characteristics of the specimens were analyzed. Test results show that after exposure to high temperatures, the specimens’ failure phenomenon in the axial compression loading test is consistent with that at room temperature, the bearing capacity decreases considerably, the ductility decreases slightly and the axial compressive stiffness changes irregularly. Temperature is the determining factor of the ultimate load of the specimen, and the reducing extent of ultimate load increases with the temperature. When the temperature reaches 1000∘C, its maximum reducing extent exceeds 50%. Among the three parameters considered in this study, the duration of high temperature has the least influence on the specimen.
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Loveikin, V. S., D. A. Palamarchyk, and Yu O. Romasevych. "Analysis of starting in horse head system at optimal jerking mode of movement." Naukovij žurnal «Tehnìka ta energetika» 11, no. 4 (September 10, 2020): 153–60. http://dx.doi.org/10.31548/machenergy2020.04.153.
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This article presents the results of an analytical study of the kinematic and power parameters of the movement of the articulated boom system of the crane at the beginning of the movement. The study was carried out during the acceleration of the electric motor of the mechanism for changing the departure from the state of rest to the rotation frequency corresponding to the nominal operating speed of the load movement. In this case, the start of the electric motor occurs, provided that the entire boom system moves along with the load according to the law of jerking optimization. The using of this regularity allows you to completely smooth out the swinging of the load at the beginning of the movement. In addition, towards the end of the acceleration, the same speeds and accelerations are provided between the end point of the crane trunk and the load. This makes it possible to ensure high smoothness of movement of the boom system, and to avoid the load swinging after the rotor of the electric motor reaches the rated speed. Also, a study of static, dynamic and total force in the drive gear rack was carried out. These studies were carried out at different duration of the process of starting the electric motor according to the law of jerking optimization. This made it possible to establish the dependence of the studied kinematic and power parameters on the duration of the transient process. Based on the above, recommendations have been developed for choosing the duration of the acceleration of the electric motor in the mechanism for changing the departure. During of the study, graphs of changes in the studied parameters of the boom system in time were built. Graphical dependencies were obtained with the most acceptable duration of the acceleration mode from the point of view of reducing the dynamic loads on the links of the boom system, improving the technological process of the crane and its ergonomics.
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Hussain, Syed Iqrar, Ammad Hassan Khan, Zia ur Rehman, Wasim Abbas, Safeer Abbas, Abdeliazim Mustafa Mohamed, Dina Mohamed Fathi, and Mubashir Aziz. "Effect of Weak Zones on Resilience of Sustainable Surface Course Mixtures of Fresh-Reclaimed Asphalt Pavement." Sustainability 14, no. 16 (August 12, 2022): 9966. http://dx.doi.org/10.3390/su14169966.
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The use of reclaimed asphalt pavement (RAP) is necessary for sustainable and cost-effective road infrastructure construction. This research investigates the effect of the area of weak zones (WZ) on the resilient modulus (MRT) of mixtures of fresh asphalt with 20% RAP. Experimentation on fresh asphalt–RAP mixtures comprising Superpave (SP-A, SP-B) and Asphalt Institute (MS-2) gradations with 20/30, 40/50, 60/70 and 80/100 penetration grade binders was carried out. WZ were determined based on the analysis of magnified digital images of asphalt specimens obtained using optical microscopy. This study demonstrates that the 20/30 grade binder caused an increase in the MRT at 25 °C up to 1.8, 2.9 and 9.2 times for a 0.1 s load duration, and 2.4, 3.0 and 9.7 times for a 0.3 s load duration. In contrast, improvement at 40 °C was observed to be up to 1.9, 3.1 and 9.7 times for a 0.1 s load duration, and 1.9, 3.0 and 12.4 times for a 0.3 s load duration in comparison with 40/50, 60/70 and 80/100 grade binders, respectively. Experimental data were validated by factorial analysis. Power trendline equations were also developed between MRT and WZ to explain the effect of gravel particle orientation on the sustainable resilience of surface course mixtures.
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Qian, Yujing, Zunyou Wu, Chao Chen, Kuifang Du, and Wenbin Wei. "Detection of HIV-1 viral load in tears of HIV/AIDS patients." Infection 48, no. 6 (August 26, 2020): 929–33. http://dx.doi.org/10.1007/s15010-020-01508-2.
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Abstract Objectives The tear, as an important bodily secretion, plays a crucial role in preventing infection and maintaining homeostasis of ocular surfaces. Although accumulating studies have reported on the HIV-1 viral load profile among varying bodily fluids and secretions, little was known concerning HIV-1 dynamics in tears. Therefore, the objectives of this study were to investigate the HIV-1 viral load in tears of HIV/AIDS patients and study factors influencing their tear viral load. Methods A cross-sectional study was conducted. 67 patients with a confirmed HIV-1 infection or AIDS were recruited from the Beijing You’an Hospital, China between April 2018 and September 2018. Socio-demographic information and laboratory test results were collected. At the same time, ophthalmic examinations were carried out and tear samples were tested. Results Of 30 highly active antiretroviral therapy (HAART)-naïve patients, 53.3% had detectable HIV-1 RNA in tears. Of 37 patients on HAART, HIV-1 RNA was undetectable in their tears, regardless of treatment duration and blood viral load. Tear viral load ranged from TND (target not detected) to 13,096 copies/mL. Viral load was lower in tears than in blood plasma (p < 0.001), and was significantly correlated with plasma viral load (Rho = 0.566, p < 0.001) and AIDS stage (Rho = 0.312, p = 0.01), but negatively correlated with CD4 + T cell count, CD4 +/CD8 + T cell count, and duration of HIV infection (Rho = -0.450, Rho = − 0.464, Rho = − 0.565; p < 0.001). Conclusions HIV-1 RNA is present in tears of more than half of the HAART-naïve patients, whereas absent in tears of patients on HAART. Tear viral load is positively associated with plasma viral load while it is negatively correlated with CD4 cell count. This study provides novel insights into the area with limited understanding–HIV-1 viral load in tears.
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Meyer, Tim, Nina Gäßler, and Wilfried Kindermann. "Determination of “Fatmax” with 1 h cycling protocols of constant load." Applied Physiology, Nutrition, and Metabolism 32, no. 2 (April 2007): 249–56. http://dx.doi.org/10.1139/h06-108.
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Several earlier studies were aimed at determining an exercise intensity that elicits maximal fat oxidation (Fatmax). However, these studies employed few different intensities or used exercise periods of too short a duration. All investigators described intensity with reference to maximal ergometric values, which might lead to metabolically inhomogeneous workloads between individuals. The aim of this study was to determine Fatmax by overcoming these methodological shortcomings of earlier investigations. Ten healthy recreational athletes (29 ± 5 y; 75 ± 6 kg; 1.81 ± 0.04 m) conducted an initial incremental cycling test to determine VO2 peak (59.2 ± 6.1 mL·min–1·kg–1) and individual anaerobic threshold (IAT; 221 ± 476 W). Within 4 weeks, 5 constant-load tests of 1 h duration were carried out at 55%, 65%, 75%, 85%, and 95% IAT. During all tests indirect calorimetry (MetaMax I, Cortex, Leipzig, Germany) served to quantify fat oxidation. Capillary blood sampling for lactate measurements was conducted every 15 min. All subjects remained in a lactate steady state during the constant load tests, which minimized influences from excess CO2. There was no difference between the 5 intensities for the percentage of energy from fat metabolism (p = 0.12). Additionally, the intensities led to similar absolute amounts of oxidized fat (p = 0.34). However, there was a significant increase in fat metabolism with increasing exercise duration (p = 0.04). It is impossible to define one theoretical optimal intensity for fat oxidation that is true in all individuals. It is thus mandatory to perform an individual assessment with indirect calorimetry. Intra-individual day-to-day variation might render the use of several tests of long duration less applicable than incremental testing with stages of sufficient duration.
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Wang, Zhenhuan, Muhammed M. Atakan, Xu Yan, Hüseyin H. Turnagöl, Honglei Duan, and Li Peng. "Graded exercise test with or without load carriage similarly measures maximal oxygen uptake in young males and females." PLOS ONE 16, no. 2 (February 1, 2021): e0246303. http://dx.doi.org/10.1371/journal.pone.0246303.
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The aim of this was to compare the effects of the graded exercise test (GXT) with or without load carriage on maximal oxygen uptake (V˙O2max) heart rate (HR), and expired ventilation (V˙E) and blood lactate in young healthy males and females. The study included ten females (age:20.2±0.7 yrs) and ten males (age:19.5±0.7 yrs) who performed the modified Bruce protocol at five load conditions; unloaded, 5, 10, 15, and 20% of body weight (BW) (kg). All the tests were performed in random order, at least 48 hours apart. During the GXTs, HR, V˙O2max, V˙E, workload and test duration were recorded and blood lactate concentration was measured before and immediately after the GXTs. V˙O2max remained unchanged during the GXTs in load and unloaded conditions for both sexes (p>0.05). Test duration was significantly less in females during the GXT with 15% BW (15.9±0.51 min vs. 18.1±1.14 min; p = 0.014) and 20% BW load carriage (15.2±0.75 min vs. 18.1±1.14 min; p = 0.020), compared to the unloaded GXT. Males showed significant decrease in the test duration during the GXT with load 15% BW (20.5±0.53 min vs. 22.8±0.61 min; p = 0.047) and with 20% BW (19.6±0.42 min vs. 22.8±0.71 min; p = 0.004), compared to the GXT with 5% BW. V˙E statistically decreased in female subjects only at 15% BW compared to 20% BW (15% BW = 77.9 ± 10.5 L/min vs. 15% BW = 72.0 ± 10.9 L/min; p = 0.045). There was no difference observed in maximal HR and blood lactate concentration between the GXTs in load and unloaded conditions. This study indicates that no matter the load % used during the GXT, V˙O2max, but not total exercise time, remains the same in young males and females.