13,940 results match your criteria average velocity


Intracranial Meningiomas Decrease in Volume on Magnetic Resonance Imaging After Discontinuing Progestin.

Neurosurgery 2021 Jun 24. Epub 2021 Jun 24.

Department of Neurosurgery, Lariboisiere Hospital, University of Paris Diderot, Paris, France.

Background: The behavior of meningiomas under influence of progestin therapy remains unclear.

Objective: To investigate the relationship between growth kinetics of intracranial meningiomas and usage of the progestin cyproterone acetate (PCA).

Methods: This study prospectively followed 108 women with 262 intracranial meningiomas and documented PCA use. Read More

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An Experimentally Validated Finite Element Model of the Lower Limb to Investigate the Efficacy of Blast Mitigation Systems.

Front Bioeng Biotechnol 2021 28;9:665656. Epub 2021 May 28.

Department of Bioengineering, Imperial College London, London, United Kingdom.

Improvised explosive devices (IEDs) used in the battlefield cause damage to vehicles and their occupants. The injury burden to the casualties is significant. The biofidelity and practicality of current methods for assessing current protection to reduce the injury severity is limited. Read More

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Kinematic factors associated with start performance in World-class male sprinters.

J Biomech 2021 Jun 7;124:110554. Epub 2021 Jun 7.

Cardiff School of Sport and Health Sciences, Cardiff Metropolitan University, Cardiff, UK.

The aim was to investigate the kinematic factors associated with successful performance in the initial acceleration phase of a sprint in the best male athletes in the World at the 2018 World Indoor Athletics Championships. High speed video (150 Hz) was captured for eight sprinters in the men's 60 m final. Spatio-temporal and joint kinematic variables were calculated from the set position to the end of the first ground contact post-block exit (GC1). Read More

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Comparison of knee extensor strength after anterior cruciate ligament reconstruction using either quadriceps tendon or hamstring tendon autografts.

Eur J Orthop Surg Traumatol 2021 Jun 21. Epub 2021 Jun 21.

Department of Orthopaedic Surgery and Sport Traumatology, Grenoble South Teaching Hospital, 38130, Echirolles, France.

Purpose: The aim was to assess the consequences of quadriceps tendon (QT) harvest on knee extensor strength after anterior cruciate ligament reconstruction (ACL-R) compared to hamstring tendon (HT) autograft. Secondary objectives were to evaluate flexor strength recovery and search for correlation between strength status and functional outcome.

Methods: This a retrospective cohort of 44 patients who underwent ACL-R using either QT (25) or HT (19). Read More

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Quantitative magnetic resonance angiography to assess post embolization hemodynamics following pipeline embolization.

Interv Neuroradiol 2021 Jun 20:15910199211023650. Epub 2021 Jun 20.

Department of Neurosurgery, Donald and Barbara Zucker School of Medicine at Hofstra Northwell, US.

Introduction: Delayed intraparenchymal hemorrhage is a known complication of the Pipeline Embolization device (PED); however, its etiology is unclear and some have suggested it is a flow related phenomenon. Quantitative magnetic resonance angiography (QMRA) serves as a powerful tool to collect and analyze hemodynamic data. We report a detailed characterization of short-term hemodynamics after PED placement. Read More

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The association of bispectral index values and metrics of cerebral perfusion during cardiopulmonary bypass.

J Clin Anesth 2021 Jun 17;74:110395. Epub 2021 Jun 17.

Department of Anesthesiology and Critical Care Medicine, School of Medicine, Johns Hopkins University, Baltimore, MD, USA; Saitama Medical Center, Jichi Medical University, Saitama 330-8503, Japan. Electronic address:

Study Objective: Low bispectral index (BIS) values have been associated with adverse postoperative outcomes. However, trials of optimizing BIS by titrating anesthetic administration have reported conflicting results. One potential explanation is that cerebral perfusion may also affect BIS, but the extent of this relationship is not clear. Read More

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Sequencing versus continuous granular sludge reactor for the treatment of freshwater aquaculture effluents.

Water Res 2021 May 26;201:117293. Epub 2021 May 26.

Universidade Católica Portuguesa, CBQF - Centro de Biotecnologia e Química Fina - Laboratório Associado, Escola Superior de Biotecnologia, Rua Diogo Botelho 1327, 4169-005 Porto, Portugal.

Ammonium and nitrite levels in water are crucial for fish health preservation and growth maintenance in freshwater aquaculture farms, limiting water recirculation. The aim of the present work was the evaluation and comparison of two granular sludge reactors which were operated to treat freshwater aquaculture streams at laboratory-scale: an Aerobic Granular Sludge - Sequencing Batch Reactor (AGS-SBR) and a Continuous Flow Granular Reactor (CFGR). Both units were fed with a synthetic medium mimicking an aquaculture recycling water (1. Read More

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Changes in intersegmental stability during gait in patients with spastic cerebral palsy.

Gait Posture 2021 Jun 11;88:264-271. Epub 2021 Jun 11.

Department of Physical Education, Seoul National University, Seoul, South Korea; Institute of Sport Science, Seoul National University, Seoul, South Korea; Advanced Institute of Convergence Technology, Seoul National University, Suwon, South Korea. Electronic address:

Background: Dysfunction in peripheral and neural structure with spastic cerebral palsy (CP) causes impaired performance and stability of various behaviors. Recent progress of quantification methods for the stability properties, which is based on the uncontrolled manifold hypothesis, has been applied to various neurological disorders. A prior study revealed that the ability for purposeful regulation of stability properties is weakened with CP during finger and hand actions. Read More

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Identification of Low-voltage Areas: A Unipolar, Bipolar and Omnipolar Perspective.

Circ Arrhythm Electrophysiol 2021 Jun 18. Epub 2021 Jun 18.

Department of Cardiology, Erasmus Medical Center, Rotterdam, the Netherlands.

- Low-voltage areas (LVA) are commonly considered surrogate markers for an arrhythmogenic substrate underlying tachyarrhythmias. It remains challenging to define a proper threshold to classify LVA and it is unknown whether unipolar, bipolar and the recently introduced omnipolar voltage mapping techniques are complementary or contradictory in classifying LVAs. Therefore, this study examined similarities and dissimilarities in unipolar, bipolar and omnipolar voltage mapping and explored the relation between various types of voltages and conduction velocity (CV). Read More

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2.05-µm all-fiber laser source designed for CO and wind coherent lidar measurement.

Appl Opt 2021 May;60(15):C12-C19

This work reports on an all-fiber pulsed laser source for simultaneous remote sensing of concentration and wind velocity in the 2.05 µm region. The source is based on a polarization-maintaining master oscillator power amplifier (MOPA) architecture. Read More

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Microbubbles intensification and mechanism of wet air oxidation process of MDEA-containing wastewater.

Environ Technol 2021 Jun 18:1-21. Epub 2021 Jun 18.

College of Chemical Engineering, Nanjing Tech University, Nanjing 210009, China.

In order to the intensification of gas-liquid mass transfer of MDEA-containing wastewater during wet air oxidation process (WAO), the microbubbles and millimeter bubbles were applied by fine-pore sparger (5μm and 20-30 μm) and single pore sparger (6.35mm), respectively. Effect of the superficial gas velocity on the average microbubble size, gas holdup and oxygen mass transfer coefficient (Ka) of MDEA-containing wastewater at the ambient conditions was studied. Read More

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Speckle-Tracking Echocardiography for Detecting Subclinical Left Ventricular Dysfunction in Patients With Familial Hypercholesterolemia.

Tex Heart Inst J 2021 Jun;48(2)

Department of Echocardiography, Beijing Anzhen Hospital, Capital Medical University and Beijing Institute of Heart Lung and Blood Vessel Diseases, Beijing, People's Republic of China.

Myocardial ischemia and left ventricular dysfunction have been documented in young adults with familial hypercholesterolemia. We investigated whether speckle-tracking echocardiography can be used to detect subclinically impaired global and regional myocardial function in patients with this lipid disorder. This single-center study included 47 patients with familial hypercholesterolemia and 37 healthy control subjects who underwent transthoracic Doppler echocardiography and speckle-tracking echocardiography from January 2003 through December 2016. Read More

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Homocysteine predicts vascular target organ damage in hypertension and may serve as guidance for first-line antihypertensive therapy.

J Clin Hypertens (Greenwich) 2021 Jun 17. Epub 2021 Jun 17.

Faculty of Medicine, Dentistry & Health Sciences, School of Medicine - Royal Perth Hospital Unit, Dobney Hypertension Centre, Royal Perth Hospital Research Foundation, The University of Western Australia, Perth, WA, Australia.

Homocysteine is an independent risk factor for cardiovascular and cerebrovascular disease and has been proposed to contribute to vascular dysfunction. We sought to determine in a real-world clinical setting whether homocysteine levels were associated with hypertension mediated organ damage (HMOD) and could guide treatment choices in hypertension. We performed a cross-sectional analysis of prospectively collected data in 145 hypertensive patients referred to our tertiary hypertension clinic at Royal Perth Hospital and analyzed the association of homocysteine with HMOD, renin-angiotensin-aldosterone system (RAAS), and RAAS blockade. Read More

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Unsteady hybrid-nanofluid flow comprising ferrousoxide and CNTs through porous horizontal channel with dilating/squeezing walls.

Sci Rep 2021 Jun 16;11(1):12637. Epub 2021 Jun 16.

Fixed Point Research Laboratory, Fixed Point Theory and Applications Research Group, Center of Excellence in Theoretical and Computational Science (TaCS-CoE), Faculty of Science, King Mongkut's University of Technology Thonburi (KMUTT), 126 Pracha Uthit Rd., Bang Mod, Thung Khru, Bangkok, 10140, Thailand.

The key objective of the present research is to examine the hybrid magnetohydrodynamics (MHD) nanofluid (Carbon-nanotubes and ferrous oxide-water) CNT-FeO/H flow into a horizontal parallel channel with thermal radiation through squeezing and dilating porous walls. The parting motion is triggered by the porous walls of the channel. The fluid flow is time-dependent and laminar. Read More

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External-field-induced dynamics of a charged particle on a closed helix.

Phys Rev E 2021 May;103(5-1):052217

Zentrum für Optische Quantentechnologien, Fachbereich Physik, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany.

We investigate the dynamics of a charged particle confined to move on a toroidal helix while being driven by an external time-dependent electric field. The underlying phase space is analyzed for linearly and circularly polarized fields. For small driving amplitudes and a linearly polarized field, we find a split up of the chaotic part of the phase space, which prevents the particle from inverting its direction of motion. Read More

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Intermittency of three-dimensional perturbations in a point-vortex model.

Phys Rev E 2021 May;103(5-1):053102

Laboratoire de Physique de l'Ecole normale supérieure, ENS, Université PSL, CNRS, Sorbonne Université, Université de Paris, F-75005 Paris, France.

Three-dimensional (3D) instabilities on a (potentially turbulent) two-dimensional (2D) flow are still incompletely understood, despite recent progress. Here, based on known physical properties of such 3D instabilities, we propose a simple, energy-conserving model describing this situation. It consists of a regularized 2D point-vortex flow coupled to localized 3D perturbations ("ergophages"), such that ergophages can gain energy by altering vortex-vortex distances through an induced divergent velocity field, thus decreasing point-vortex energy. Read More

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Cumulative impact of multiple evidence based strategies on postnatal growth of extremely-low-birth-weight infants.

Clin Nutr 2021 Jun 1;40(6):3908-3913. Epub 2021 Jun 1.

Biostatistics, OSF Saint Francis Medical Center, Peoria, IL, United States.

Background: Postnatal growth failure is common in very preterm infants and is associated with worse neurodevelopmental outcome.

Objective: To evaluate the cumulative impact of multiple evidence based strategies on the postnatal growth of extremely-low-birth-weight (ELBW) infants.

Methods: We conducted a prospective observational study. Read More

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Can the exercise-based and occupational therapy improve the posture, strength, and mobility in elderly Greek subjects with hip fracture? A non-randomized control trial.

J Frailty Sarcopenia Falls 2021 Jun 1;6(2):57-65. Epub 2021 Jun 1.

Medical School, Department of Medicine, Democritus University of Thrace, Alexandroupolis, Greece.

Objectives: The effects of a rehabilitation program on static balance, mobility, and strength of lower limbs in elderly fallers operated after a hip fracture and non-operated were studied.

Methods: Ninety-one elderly (>65 years) were divided in two groups, the Operated Group (OG, 43 fallers) and the Non-Operated Group (NOG, 48 fallers). Posture during bipedal stance (30s), mobility (Up-and-Go, Falls Efficacy Scale, Berg Balance Scale) and isokinetic strength of several muscular groups in both limbs were evaluated before and after a rehabilitation intervention, consisting in 20 sessions (3 sessions/week) including kinesiotherapy and occupational therapy. Read More

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Which variables may affect underwater glide performance after a swimming start?

Eur J Sport Sci 2021 Jun 15:1-20. Epub 2021 Jun 15.

University of Castilla-La Mancha, Sport Training Lab, Toledo, Spain.

The underwater phase is perhaps the most important phase of the swimming start. To improve performance during the underwater phase, it is necessary to improve our understanding of the key variables affecting this phase. The main aim of this study was to identify key kinematic variables that are associated with the performance of an underwater glide of a swimming start, when performed at streamlined position without underwater undulatory swimming. Read More

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Heading in Football: Incidence, Biomechanical Characteristics and the Association with Acute Cognitive Function-A Three-Part Systematic Review.

Sports Med 2021 Jun 15. Epub 2021 Jun 15.

Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, UK.

Background: There is growing concern surrounding the role of repetitive sub-concussive head impacts, such as football heading, on brain health.

Objectives: Three questions were addressed while only considering studies that observed heading exposure directly: (1) how frequently does heading occur within football training and matches, (2) what are the biomechanical characteristics of heading, and (3) is cognitive function affected by heading?

Methods: This review followed the steps described in the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines. Electronic databases including MEDLINE and SPORTDiscus were searched from the earliest entry to July 2020. Read More

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Measurements of exhaled airflow velocity through human coughs using particle image velocimetry.

Build Environ 2021 Sep 9;202:108020. Epub 2021 Jun 9.

School of Engineering, The University of Tokyo, Tokyo, Japan.

The sudden outbreak of coronavirus (COVID-19) has infected over 100 million people and led to over two million deaths (data in January 2021), posing a significant threat to global human health. As a potential carrier of the novel coronavirus, the exhaled airflow of infected individuals through coughs is significant in virus transmission. The research of detailed airflow characteristics and velocity distributions is insufficient because most previous studies utilize particle image velocimetry (PIV) with low frequency. Read More

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September 2021

Brachial-ankle pulse wave velocity and prognosis in patients with atherosclerotic cardiovascular disease: a systematic review and meta-analysis.

Hypertens Res 2021 Jun 14. Epub 2021 Jun 14.

Department of Special Care Center, Fuwai Hospital, National Clinical Research Center for Cardiovascular Diseases, National Center for Cardiovascular Diseases, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, China.

Arterial stiffness has been suggested as an independent cardiovascular risk factor. This systematic review and meta-analysis aimed to quantify the association between brachial-ankle pulse wave velocity (baPWV) and prognosis in atherosclerotic cardiovascular disease (ASCVD) patients. The PubMed, EMBASE, and Cochrane Library databases were searched for cohort studies examining the association of high baPWV with prognosis in ASCVD patients. Read More

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Simultaneous umbilical blood flow during normal pregnancy in sheep and goat foetuses using non-invasive colour Doppler ultrasound.

Anim Reprod 2018 Aug 16;15(2):148-155. Epub 2018 Aug 16.

Institute of Reproductive Biology, University of Veterinary Medicine Hannover, 30559 Hannover, Germany.

The characteristics of umbilical blood flow (UM) was investigated using 18 (25 foetuses) pregnant ewes and 20 (41 foetus) pregnant goats transrectal non-invasive color Doppler ultrasonographic examinations were done frequently between 2 and 8 week after breeding and then transabdominally until parturition. Colour Doppler velocimetery includes blood flow volume (BFV), time averaged maximum velocity (TAMV), resistance index (RI), pulsatility index (PI), time average of mean (TAMEAN) and impedance of blood flow (PS/ED or AB ratio). Also a qualitative evaluation of UM blood flow indicating increases (P < 0. Read More

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Numerical parametric study of Nonlinear Coda Wave Interferometry sensitivity to microcrack size in a multiple scattering medium.

Ultrasonics 2021 Jun 1;116:106483. Epub 2021 Jun 1.

Laboratoire d'Acoustique de l'Université du Mans (LAUM), UMR 6613, Institut d'Acoustique - Graduate School (IA-GS), CNRS, Le Mans Université, France.

This paper reports a numerical study of the sensitivity and applicability of the Nonlinear Coda Wave Interferometry (NCWI) method in a heterogeneous material with a localized microcracked zone. We model the influence of a strong pump wave on the localized microcracked zone as a small average increase in the length of each crack. Further probing of this microcracked zone with a multiply scattered ultrasonic wave induces small changes to the coda-type signal, which are quantified with coda wave interferometry. Read More

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An examination into the effect of genetic taste status and intensity of carbonation on swallowing and palatability in healthy young adults.

Int J Lang Commun Disord 2021 Jun 14. Epub 2021 Jun 14.

Department of Clinical Speech and Language Studies, Trinity College Dublin, Ireland.

Background: Dysphagia is a highly prevalent condition and affects a wide range of cohorts. A common compensatory strategy to manage dysphagia is diet modification. However, this technique is often associated with poor patient quality of life and adverse long-term effects. Read More

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Speed but Not Smoothness of Gait Reacts to Rehabilitation in Multiple Sclerosis.

Mult Scler Int 2021 3;2021:5589562. Epub 2021 Jun 3.

Centre for Clinical Neuroplasticity Medical Park Loipl, Bischofswiesen, Germany.

Introduction: Improved gait is one of the leading therapy goals in multiple sclerosis. A plethora of clinical timed trials and state-of-the-art technology-based approaches are available to assess gait performance.

Objectives: To examine what aspects of gait react to inpatient rehabilitation in MS and which parameters should be best assessed. Read More

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Retrospective Analysis of Training and Its Response in Marathon Finishers Based on Fitness App Data.

Front Physiol 2021 21;12:669884. Epub 2021 May 21.

Machine Learning and Data Analytics Lab, Department Artificial Intelligence in Biomedical Engineering, University of Erlangen-Nürnberg (FAU), Erlangen, Germany.

Finishing a marathon requires to prepare for a 42.2 km run. Current literature describes which training characteristics are related to marathon performance. Read More

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Ontogenetic shape trajectory of Trichomycterus areolatus varies in response to water velocity environment.

PLoS One 2021 11;16(6):e0252780. Epub 2021 Jun 11.

Department of Biology, Brigham Young University, Provo, Utah, United States of America.

Body and head shape among fishes both vary between environments influenced by water velocity and across ontogeny. Although the shape changes associated with variation in average water velocity and ontogeny are well documented, few studies have tested for the interaction between these two variables (i.e. Read More

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A New Approach of Sperm Motility Subpopulation Structure in Donkey and Horse.

Front Vet Sci 2021 25;8:651477. Epub 2021 May 25.

Equine Reproduction Service, Autonomous University of Barcelona, Department of Animal Medicine and Surgery Veterinary Faculty, Catalonia, Spain.

This study aimed to characterize the sperm kinematic values with high frames per second, to define the subpopulation structure of a horse and a donkey and compare them. A total of 57 fresh semen ejaculates (26 Spanish and 16 Arabian horse breeds and 10 donkeys) were collected and subsequently analyzed for kinematic parameters using the Computer-aided sperm motility analysis ISAS®v1.2 system and using a Spermtrack® 10-μm depth counting chamber. Read More

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[Effect of band ligation or combined with tissue adhesive in the treatment of gastroesophageal varices and portal vein blood flow situational changes].

Zhonghua Gan Zang Bing Za Zhi 2021 May;29(5):468-471

Department of Endoscopy, The First Affiliated Hospital of Fujian Medical University, Fuzhou 350005, China.

42 cases with gastroesophageal varices were prospectively included. The groups were treated with endoscopic band ligation or combined with tissue adhesive. The results showed that the left gastric vein internal diameter, average blood flow velocity and blood flow volume after the treatment of band ligation combined with tissue adhesive were significantly lower than that of the treatment of band ligation alone, and the differences were statistically significant ( < 0. Read More

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