2,702 research outputs found
Methodological factors affecting joint moments estimation in clinical gait analysis: A systematic review
Quantitative gait analysis can provide a description of joint kinematics and dynamics, and it is recognized as a clinically useful tool for functional assessment, diagnosis and intervention planning. Clinically interpretable parameters are estimated from quantitative measures (i.e. ground reaction forces, skin marker trajectories, etc.) through biomechanical modelling. In particular, the estimation of joint moments during motion is grounded on several modelling assumptions: (1) body segmental and joint kinematics is derived from the trajectories of markers and by modelling the human body as a kinematic chain; (2) joint resultant (net) loads are, usually, derived from force plate measurements through a model of segmental dynamics. Therefore, both measurement errors and modelling assumptions can affect the results, to an extent that also depends on the characteristics of the motor task analysed (i.e. gait speed). Errors affecting the trajectories of joint centres, the orientation of joint functional axes, the joint angular velocities, the accuracy of inertial parameters and force measurements (concurring to the definition of the dynamic model), can weigh differently in the estimation of clinically interpretable joint moments. Numerous studies addressed all these methodological aspects separately, but a critical analysis of how these aspects may affect the clinical interpretation of joint dynamics is still missing. This article aims at filling this gap through a systematic review of the literature, conducted on Web of Science, Scopus and PubMed. The final objective is hence to provide clear take-home messages to guide laboratories in the estimation of joint moments for the clinical practice
H2 from biofuels and carriers: A concerted homo-heterogeneous kinetic model of ethanol partial oxidation and steam reforming on Rh/Al2O3
Investigating bioethanol as a renewable energy source is crucial in the context of H2-based economy. Ethanol partial oxidation and steam reforming on Rh/Al2O3 represent promising processes that have already proved to be highly tangled reacting systems. In this work, a significant step forward has been done towards the development of an engineering tool that can capture all the relevant features of the process; a combined homo-heterogeneous kinetic scheme was developed and validated against experimental data, informative of the catalytic and thermal activation of the C2-alcohol. In particular, a 36-species reduced homogeneous scheme was developed, able to cap -ture observed trends with a limited computational load. On the other side, a macro-kinetic heterogeneous scheme with six molecular reactions (ethanol oxidative dehydrogenation, total oxidation, decomposition, dehydrogenation, steam reforming and acetaldehyde post -reforming) was tuned to accurately describe ethanol/O2 and ethanol/H2O reacting systems.& COPY; 2023 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved
Tug of war between survival and death: exploring ATM function in cancer.
Ataxia-telangiectasia mutated (ATM) kinase is a one of the main guardian of genome stability and plays a central role in the DNA damage response (DDR). The deregulation of these pathways is strongly linked to cancer initiation and progression as well as to the development of therapeutic approaches. These observations, along with reports that identify ATM loss of function as an event that may promote tumor initiation and progression, point to ATM as a bona fide tumor suppressor. The identification of ATM as a positive modulator of several signalling networks that sustain tumorigenesis, including oxidative stress, hypoxia, receptor tyrosine kinase and AKT serine-threonine kinase activation, raise the question of whether ATM function in cancer may be more complex. This review aims to give a complete overview on the work of several labs that links ATM to the control of the balance between cell survival, proliferation and death in cancer
Lanthanoid β-triketonates: a new class of highly efficient NIR emitters for bright NIR-OLEDs
The reaction of hydrated YbCl3 with potassium tribenzoylmethanide yields a new bimetallic tetranuclear Yb3+/K+ assembly. This species not only possesses the longest excited state lifetime and quantum yield reported for the Yb3+ diketonate family but is also suitable to be incorporated in NIR-OLEDs, whose performance outclasses any other reported lanthanoid-based device with NIR emission
NGC 5385, NGC 2664 and Collinder 21: three candidate Open Cluster Remnants
We present CCD UBVI photometric and medium/high resolution spectroscopic
observations obtained in the field of the previously unstudied dissolving open
cluster candidates NGC 5385, NGC 2664 and Collinder~21. Our analysis stands on
the discussion of star counts, photometry, radial velocity distribution, and
proper motions available from the Tycho~2 catalogue. All the three aggregates
clearly emerge from the mean Galactic field, but, regrettably, the close
scrutiny of proper motions and radial velocities reveals that we are not facing
any physical group. Instead, what we are looking at are just chance alignments
of a few bright unrelated stars. Our analysis casts some doubt on the Bica et
al. (2001) criterion to look for Possible Open Cluster Remnants. It seems
mandatory to define a better criterion to adopt for further investigations.Comment: 12 pages, 12 eps figures (7, 9 and 11 degraded in resolution),
accepted for publication in Astronomy & Astrophysic
Highlighting the Role of Lubricant Oil in the Development of Hydrogen Internal Combustion Engines by means of a Kinetic Reaction Model
One-step assembly of Re(I) tricarbonyl 2-pyridyltetrazolato metallacalix[3]arene with aqua emission and reversible three-electron oxidation
The reaction of 2-pyridyltetrazolate with [Re(CO)5X] (X = Cl, Br) yielded the formation of an unexpected cyclic metallacalix[3]-arene, as revealed by X-ray structural studies, characterised by aqua emission and reversible three-electron oxidation
Fully-resolved simulations of coal particle combustion using a detailed multi-step approach for heterogeneous kinetics
Fully-resolved simulations of the heating, ignition, volatile flame combustion and char conversion of single coal particles in convective gas environments are conducted and compared to experimental data (Molina and Shaddix, 2007). This work extends a previous computational study (Tufano et al., 2016) by adding a significant level of model fidelity and generality, in particular with regard to the particle interior description and hetero-
geneous kinetics. The model considers the elemental analysis of the given coal and interpolates its properties by linear superposition of a set of reference coals. The improved model description alleviates previously made assumptions of single-step pyrolysis, fixed volatile composition and simplified particle interior properties, and it
allows for the consideration of char conversion. The results show that the burning behavior is affected by the oxygen concentration, i.e. for enhanced oxygen levels ignition occurs in a single step, whereas decreasing the oxygen content leads to a two-stage ignition process. Char conversion becomes dominant once the volatiles have been depleted, but also causes noticeable deviations of temperature, released mass, and overall particle con- version during devolatilization already, indicating an overlap of the two stages of coal conversion which are usually considered to be consecutive. The complex pyrolysis model leads to non-monotonous profiles of the combustion quantities which introduce a minor dependency of the ignition delay time on its definition. Regardless of the chosen extraction method, the simulations capture the measured values of very well
Comparison of a fast track protocol and standard care after hip arthroplasty in the reduction of the length of stay and the early weight-bearing resumption: study protocol for a randomized controlled trial
Background: To date, hip arthroplasty is one of the most commonly performed surgical procedures, with growing worldwide demand. In recent decades, major progress made in terms of surgical technique, biomechanics, and tribology knowledge has contributed to improve the medical and functional management of the patient. This study aims to assess if the application of a fast track protocol, consisting of a preoperative educational intervention, adequate postoperative pain control, and intensive rehabilitation intervention, reduces the length of stay (LOS) and allows the early functional recovery compared to standard clinical practice for patients undergoing hip arthroplasty. Methods: The study population consists of 90 patients with primary arthrosis of the hip with an anterior indication of hip arthroplasty. The exclusion criteria are older than 70 years, a contraindication to performing spinal anesthesia, and bone mass index (BMI) greater than 32. Participants, 45 for each group, are randomly allocated to one of two arms: fast track clinical pathway or standard care protocol. During allocation, baseline parameters such as Harris Hip Score (HHS) and Western Ontario and McMaster Universities (WOMAC) index are collected. On the third postoperative day, the functional autonomy for each patient is assessed by the Iowa Level of Assistance (ILOA) scale, and it is expected the discharge for patients in the fast track group (primary outcome). On the other hand, standard care patient discharge is expected after 5–7 days after surgery. During follow-up fixed at 6 weeks and 3, 6, and 12 months, HHS and WOMAC scores are collected for each patient (secondary outcomes). Discussion: Although total hip replacement has become a widespread standardized procedure, to the authors’ knowledge, only few randomized controlled trials were performed to evaluate the effectiveness of fast track pathway vs. standard care procedure in the reduction of the LOS after hip arthroplasty. It is expected that our results collected by the application of minimally invasive surgical interventions with concomitant management of perioperative pain and bleeding and early functional rehabilitation will contribute to enriching the understanding of clinical and organizational aspects linked to fast track arthroplasty. Trial registration: ClinicalTrials.gov NCT03875976. Registered on 15 March 2019—“retrospectively registered”
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