325 research outputs found
Muscle force contributions to anterior cruciate ligament loading
Anterior cruciate ligament (ACL) injuries are one of the most common knee pathologies sustained during athletic participation and are characterised by long convalescence periods and associated financial burden. Muscles have the ability to increase or decrease the mechanical loads on the ACL, and thus are viable targets for preventative interventions. However, the relationship between muscle forces and ACL loading has been investigated by many different studies, often with differing methods and conclusions. Subsequently, this review aimed to summarise the evidence of the relationship between muscle force and ACL loading. A range of studies were found that investigated muscle and ACL loading during controlled knee flexion, as well as a range of weightbearing tasks such as walking, lunging, sidestep cutting, landing and jumping. The quadriceps and the gastrocnemius were found to increase load on the ACL by inducing anterior shear forces at the tibia, particularly when the knee is extended. The hamstrings and soleus appeared to unload the ACL by generating posterior tibial shear force; however, for the hamstrings, this effect was contingent on the knee being flexed greater than ~ 20° to 30°. The gluteus medius was consistently shown to oppose the knee valgus moment (thus unloading the ACL) to a magnitude greater than any other muscle. Very little evidence was found for other muscle groups with respect to their contribution to the loading or unloading of the ACL. It is recommended that interventions aiming to reduce the risk of ACL injury consider specifically targeting the function of the hamstrings, soleus and gluteus medius
Experimental Investigation On Nanoparticles Suspended Liquid (NSL) As The Heat Transfer Fluid (HTF) For Solar Evacuated Tube Collector
This study investigates the thermal performance of a solar evacuated tube collector (SETC) using nanoparticles suspended liquid (NSL) as the heat transfer fluid (HTF). The NSL is composed of water with different concentration of TiO2, CuO, Cr2O3, TiO2+CuO+ Cr2O3 NSL With average size of ~25 nm. The experimental results show that the use of NSL increase the thermal performance of the SETC to be about 2% higher than that of the SETC without NSL. The enhancement in the thermal performance is mainly attributed to the higher thermal conductivity and specific heat capacity of the NSL. In addition, the effects of NSL concentration, flow rate and temperature on the thermal performance of the SETC with NSL were also studied. It was observed that the thermal performance of the SETC with NSL increases with increasing NSL concentration and flow rate but decreases with rise in the temperature. The results of this study can be used to optimize the design of solar evacuated tube collectors using NSL as the HTF for better thermal performance
Building a collaborative culture in cardiothoracic operating rooms: Pre and postintervention study protocol for evaluation of the implementation of teamSTEPPS training and the impact on perceived psychological safety
IntroductionThe importance of effective communication, a key component of teamwork, is well recognised in the healthcare setting. Establishing a culture that encourages and empowers team members to speak openly in the cardiothoracic (CT) operating room (OR) is necessary to improve patient safety in this high-risk environment.Methods and analysisThis study will take place at Barnes-Jewish Hospital, an academic hospital in affiliation with Washington University School of Medicine located in the USA. All team members participating in cardiac and thoracic OR cases during this 17-month study period will be identified by the primary surgical staff attending on the OR schedule.TeamSTEPPS (Team Strategies and Tools to Enhance Performance and Patient Safety) training course will be taught to all CT OR staff. Before TeamSTEPPS training, staff will respond to a 39-item questionnaire that includes constructs from the Agency for Healthcare Research and Quality Hospital Survey on Patient Safety Culture, Edmondson’s ‘Measure of psychological safety’ questionnaire, and questionnaires on turnover intentions, job satisfaction and ‘burnout’. The questionnaires will be readministered at 6 and 12 months.The primary outcomes to be assessed include the perceived psychological safety of CT OR team members, the overall effect of TeamSTEPPS on burnout and job satisfaction, and observed turnover rate among the OR nurses. As secondary outcomes, we will be assessing self-reported rates of medical error and near misses in the ORs with a questionnaire at the end of each case.Ethics and disseminationEthics approval is not indicated as this project does not meet the federal definitions of research requiring the oversight of the Institutional Review Board (IRB). Patient health information (PHI) will not be generated during the implementation of this project. Results of the trial will be made accessible to the public when published in a peer-reviewed journal following the completion of the study.</jats:sec
Non-autonomous stochastic evolution equations and applications to stochastic partial differential equations
In this paper we study the following non-autonomous stochastic evolution
equation on a UMD Banach space with type 2,
{equation}\label{eq:SEab}\tag{SE} {{aligned} dU(t) & = (A(t)U(t) + F(t,U(t)))
dt + B(t,U(t)) dW_H(t), \quad t\in [0,T],
U(0) & = u_0. {aligned}. {equation}
Here are unbounded operators with domains
which may be time dependent. We assume that
satisfies the conditions of Acquistapace and Terreni. The
functions and are nonlinear functions defined on certain interpolation
spaces and is the initial value. is a cylindrical Brownian
motion on a separable Hilbert space .
Under Lipschitz and linear growth conditions we show that there exists a
unique mild solution of \eqref{eq:SEab}. Under assumptions on the interpolation
spaces we extend the factorization method of Da Prato, Kwapie\'n, and Zabczyk,
to obtain space-time regularity results for the solution of
\eqref{eq:SEab}. For Hilbert spaces we obtain a maximal regularity result.
The results improve several previous results from the literature.
The theory is applied to a second order stochastic partial differential
equation which has been studied by Sanz-Sol\'e and Vuillermot. This leads to
several improvements of their result.Comment: Accepted for publication in Journal of Evolution Equation
CD137 promotes proliferation and survival of human B cells
CD137 (4-1BB)-mediated costimulation plays an important role in directing the fate of Ag-stimulated T cells and NK cells, yet the role of CD137 in mediating B cell function is unknown. We found that CD137 is expressed in vitro on anti-Ig–stimulated peripheral blood B cells and in vivo on tonsillar B cells with an activated phenotype. In vitro CD137 expression is enhanced by CD40 stimulation and IFN-g and is inhibited by IL-4, -10, and -21. The expression of CD137 on activated human B cells is functionally relevant because engagement with its ligand at the time of activation stimulates B cell proliferation, enhances B cell survival, and induces secretion of TNF-a and -b. Our study suggests that CD137 costimulation may play a role in defining the fate of Agstimulated human B cells.Fil: Zhang, Xiaoyu. University of Maryland; Estados UnidosFil: Voskens, Caroline J.. University of Maryland; Estados UnidosFil: Sallin, Michelle. University of Maryland; Estados UnidosFil: Maniar, Amudhan. University of Maryland; Estados UnidosFil: Montes, Carolina Lucia. University of Maryland; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; ArgentinaFil: Zhang, Yue. University of Maryland; Estados UnidosFil: Lin, Wei. University of Maryland; Estados UnidosFil: Li, Guoyan. University of Maryland; Estados UnidosFil: Burch, Erin. University of Maryland; Estados UnidosFil: Tan, Ming. University of Maryland; Estados UnidosFil: Hertzano, Ronna. University of Maryland; Estados UnidosFil: Chapoval, Andrei I.. University of Maryland; Estados UnidosFil: Tamada, Koji. University of Maryland; Estados UnidosFil: Gastman, Brian R.. University of Maryland; Estados UnidosFil: Schulze, Dan H.. University of Maryland; Estados UnidosFil: Strome, Scott E.. University of Maryland; Estados Unido
Blinatumomab vs historical standard therapy of adult relapsed/refractory acute lymphoblastic leukemia
We compared outcomes from a single-arm study of blinatumomab in adult patients with B-precursor Ph-negative relapsed/refractory acute lymphoblastic leukemia (R/R ALL) with a historical data set from Europe and the United States. Estimates of complete remission (CR) and overall survival (OS) were weighted by the frequency distribution of prognostic factors in the blinatumomab trial. Outcomes were also compared between the trial and historical data using propensity score methods. The historical cohort included 694 patients with CR data and 1112 patients with OS data compared with 189 patients with CR and survival data in the blinatumomab trial. The weighted analysis revealed a CR rate of 24% (95% CI: 20-27%) and a median OS of 3.3 months (95% CI: 2.8-3.6) in the historical cohort compared with a CR/CRh rate of 43% (95% CI: 36-50%) and a median OS of 6.1 months (95% CI: 4.2-7.5) in the blinatumomab trial. Propensity score analysis estimated increased odds of CR/CRh (OR=2.68, 95% CI: 1.67-4.31) and improved OS (HR=0.536, 95% CI: 0.394-0.730) with blinatumomab. The analysis demonstrates the application of different study designs and statistical methods to compare novel therapies for R/R ALL with historical data
Scalar and vector Slepian functions, spherical signal estimation and spectral analysis
It is a well-known fact that mathematical functions that are timelimited (or
spacelimited) cannot be simultaneously bandlimited (in frequency). Yet the
finite precision of measurement and computation unavoidably bandlimits our
observation and modeling scientific data, and we often only have access to, or
are only interested in, a study area that is temporally or spatially bounded.
In the geosciences we may be interested in spectrally modeling a time series
defined only on a certain interval, or we may want to characterize a specific
geographical area observed using an effectively bandlimited measurement device.
It is clear that analyzing and representing scientific data of this kind will
be facilitated if a basis of functions can be found that are "spatiospectrally"
concentrated, i.e. "localized" in both domains at the same time. Here, we give
a theoretical overview of one particular approach to this "concentration"
problem, as originally proposed for time series by Slepian and coworkers, in
the 1960s. We show how this framework leads to practical algorithms and
statistically performant methods for the analysis of signals and their power
spectra in one and two dimensions, and, particularly for applications in the
geosciences, for scalar and vectorial signals defined on the surface of a unit
sphere.Comment: Submitted to the 2nd Edition of the Handbook of Geomathematics,
edited by Willi Freeden, Zuhair M. Nashed and Thomas Sonar, and to be
published by Springer Verlag. This is a slightly modified but expanded
version of the paper arxiv:0909.5368 that appeared in the 1st Edition of the
Handbook, when it was called: Slepian functions and their use in signal
estimation and spectral analysi
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