353 research outputs found
Rates of symptom reoccurrence after endovascular therapy in subclavian artery stenosis and prevalence of subclavian artery stenosis prior to coronary artery bypass grafting
Percutaneous transluminal angioplasty (PTA) and stenting is commonly used to treat subclavian artery stenosis (SAS). In this study, the outcomes of 43 consecutive cases, performed at one institution from October 1997 to October 2005, were analyzed. Mean stenosis was 84.41% pre-intervention and 6.83% post-intervention. Five of the procedures were angioplasty alone; 38 were angioplasty with stenting. Technical success was achieved in 42 out of 43 patients. The 30-day mortality rate was 0%. At one-month post intervention, all patients were symptom free. Ten patients redeveloped symptoms by one year. Demographic data, patient comorbidities, and indication to treat were analyzed. It was found that prior coronary intervention led to a statistically significant higher rate of symptom reoccurrence (p = 0.036). Additionally, a divergence in the rate of symptom reoccurrence based on indication to treat SAS was noted with the highest rate of symptom reoccurrence in the pre-coronary artery bypass grafting (CABG) group and the lowest rate of symptom reoccurrence in the subclavian steal syndrome (SSS) group. The coronary subclavian steal (CSS) group had an intermediate rate of symptom reoccurrence. During this time period, 1154 CABGs were performed. Flow-limiting stenosis was noted on angiography in 17 of these patients, giving pre-CABG prevalence of 1.46%
Thermal noise limitations to force measurements with torsion pendulums: Applications to the measurement of the Casimir force and its thermal correction
A general analysis of thermal noise in torsion pendulums is presented. The
specific case where the torsion angle is kept fixed by electronic feedback is
analyzed. This analysis is applied to a recent experiment that employed a
torsion pendulum to measure the Casimir force. The ultimate limit to the
distance at which the Casimir force can be measured to high accuracy is
discussed, and in particular the prospects for measuring the thermal correction
are elaborated upon.Comment: one figure, five pages, to be submitted to Phys Rev
Organisational participation and women - an attitude problem?
Employee participation is a dynamic and contested area of organisational behaviour, attracting continuing academic, practitioner and policy interest and debate. This chapter focuses on organisational participation and women
Perillyl alcohol in Solid Lipid Nanoparticles (SLN-PA): Cytotoxicity and antitumor potential in sarcoma 180 mice model
Cancer is a group of diseases characterized by the uncontrolled growth of cells. These cells invade organs and tissues by extension or direct dissemination and can spread to other regions of the body.
Nanomedicine offers many possibilities to prevent the spread of cancer tissue and help cure the disease.
In this work, solid lipid nanoparticles (SLN) were used to encapsulate perillyl alcohol (PA), a volatile
monoterpene with proven anticancer activity. Encapsulation of PA into SLN (SLN-PA) is expected to
promote controlled release, increase PA bioavailability, and impair the volatility of the monoterpene.
SLN-PA prepared by high-shear homogenization showed average particle diameter around 254 nm,
polydispersity index ~ 0.35, zeta potential ~ -14.7 mV, and encapsulation efficiency 84.6%. Scanning
electron microscope analysis revealed a decrease in crystallinity, suggesting the encapsulation of PA in
the SLN, confirming the spherical shape and the loading of the monoterpene in the SLN. In vitro cytotoxicity
assays against murine fibroblasts (L929) showed that SLN-PA in both treated doses did not
induce any cytotoxicity on non-tumoral cells. In vivo antitumor effect of the SLN-PA was evaluated in
sarcoma 180-transplanted mice. The in vivo results demonstrated a significant tumor inhibition rate of
51.76 and 54.49% via intraperitoneal application of SLN-PA at doses of 100 and 200 mg/kg/day (p <
0.05), respective when compared to the negative control (dimethyl sulfoxide). Adverse side effects of
SLN-PA were not noticed in the liver, the kidney, or spleen tissue. The developed SLN-PA can be
considered as a safe approach for site-specific antitumor effect in vivo, reinterpreting new nanoparticles-
based cancer therapy.This work was supported by the Banco do Nordeste (grant FUNDECI/2016.0015), Conselho Nacional
de Desenvolvimento CientĂfico e TecnolĂłgico (CNPq), Fundação de Apoio Ă Pesquisa e Ă Inovação
TecnolĂłgica do Estado de Sergipe (Fapitec) and Coordenação de Aperfeiçoamento de Pessoal de NĂvel
Superior (CAPES). Eliana B. Souto would like to acknowledge the Portuguese Science and Technology
Foundation (FCT/MCT) and from European Funds (PRODER/COMPETE) for the project
UIDB/04469/2020 (strategic fund), co-financed by FEDER, under the Partnership Agreement PT2020.info:eu-repo/semantics/publishedVersio
Precision Measurement of the Newtonian Gravitational Constant Using Cold Atoms
About 300 experiments have tried to determine the value of the Newtonian
gravitational constant, G, so far, but large discrepancies in the results have
made it impossible to know its value precisely. The weakness of the
gravitational interaction and the impossibility of shielding the effects of
gravity make it very difficult to measure G while keeping systematic effects
under control. Most previous experiments performed were based on the torsion
pendulum or torsion balance scheme as in the experiment by Cavendish in 1798,
and in all cases macroscopic masses were used. Here we report the precise
determination of G using laser-cooled atoms and quantum interferometry. We
obtain the value G=6.67191(99) x 10^(-11) m^3 kg^(-1) s^(-2) with a relative
uncertainty of 150 parts per million (the combined standard uncertainty is
given in parentheses). Our value differs by 1.5 combined standard deviations
from the current recommended value of the Committee on Data for Science and
Technology. A conceptually different experiment such as ours helps to identify
the systematic errors that have proved elusive in previous experiments, thus
improving the confidence in the value of G. There is no definitive relationship
between G and the other fundamental constants, and there is no theoretical
prediction for its value, against which to test experimental results. Improving
the precision with which we know G has not only a pure metrological interest,
but is also important because of the key role that G has in theories of
gravitation, cosmology, particle physics and astrophysics and in geophysical
models.Comment: 3 figures, 1 tabl
Psychometric Evaluation of the Arabic Version of the Spiritual Well-Being Scale on a Sample of Jordanian Arab Christians
This paper assesses the psychometric properties of the Arabic version of the Spiritual Well-Being Scale (SWBS) in an Arab Christian sample by analyzing its internal structure. A convenience sample of 340 Arab Christians was recruited from the adult community population of northern Jordan. Data were collected through a self-completion, anonymous questionnaire distributed through church and community groups. Principal Components factor analysis, non-parametric bivariate statistics, and Cronbach's alpha were used to assess the psychometric properties of the total scale and its subscales. The findings broadly supported the factor structure of the SWBS in other Arab samples in that the scale consists of three factors, representing positive existential well-being, affiliation, and alienation subscales. In conclusion, these preliminary findings suggest that the Arabic version of the SWBS can be used as an instrument to measure levels of spiritual well-being in Arab Christian populations. </jats:p
Phenomenology of the Lense-Thirring effect in the Solar System
Recent years have seen increasing efforts to directly measure some aspects of
the general relativistic gravitomagnetic interaction in several astronomical
scenarios in the solar system. After briefly overviewing the concept of
gravitomagnetism from a theoretical point of view, we review the performed or
proposed attempts to detect the Lense-Thirring effect affecting the orbital
motions of natural and artificial bodies in the gravitational fields of the
Sun, Earth, Mars and Jupiter. In particular, we will focus on the evaluation of
the impact of several sources of systematic uncertainties of dynamical origin
to realistically elucidate the present and future perspectives in directly
measuring such an elusive relativistic effect.Comment: LaTex, 51 pages, 14 figures, 22 tables. Invited review, to appear in
Astrophysics and Space Science (ApSS). Some uncited references in the text
now correctly quoted. One reference added. A footnote adde
Vitalism and the Resistance to Experimentation on Life in the Eighteenth Century
There is a familiar opposition between a âScientific Revolutionâ ethos and practice of experimentation, including experimentation on life, and a âvitalistâ reaction to this outlook. The former is often allied with different forms of mechanism â if all of Nature obeys mechanical laws, including living bodies, âiatromechanismâ should encounter no obstructions in investigating the particularities of animal-machines â or with more chimiatric theories of life and matter, as in the âOxford Physiologistsâ. The latter reaction also comes in different, perhaps irreducibly heterogeneous forms, ranging from metaphysical and ethical objections to the destruction of life, as in Margaret Cavendish, to more epistemological objections against the usage of instruments, the âanatomicalâ outlook and experimentation, e.g. in Locke and Sydenham. But I will mainly focus on a third anti-interventionist argument, which I call âvitalistâ since it is often articulated in the writings of the so-called Montpellier Vitalists, including their medical articles for the EncyclopĂ©die. The vitalist argument against experimentation on life is subtly different from the metaphysical, ethical and epistemological arguments, although at times it may borrow from any of them. It expresses a Hippocratic sensibility â understood as an artifact of early modernity, not as some atemporal trait of medical thought â in which Life resists the experimenter, or conversely, for the experimenter to grasp something about Life, it will have to be without torturing or radically intervening in it. I suggest that this view does not have to imply that Nature is something mysterious or sacred; nor does the vitalist have to attack experimentation on life in the name of some âvital forceâ â which makes it less surprising to find a vivisectionist like Claude Bernard sounding so close to the vitalists
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