466 research outputs found
Superconducting properties of the In-substituted topological crystalline insulator, SnTe
We report detailed investigations of the properties of a superconductor obtained by substituting In at the Sn site in the topological crystalline insulator (TCI), SnTe. Transport, magnetization and heat capacity measurements have been performed on crystals of SnInTe, which is shown to be a bulk superconductor with at ~K and at ~K. The upper and lower critical fields are estimated to be ~T and ~mT respectively, while indicates this material is a strongly type II superconductor
Vitalism in Early Modern Medical and Philosophical Thought
Vitalism is a notoriously deceptive term. It is very often defined as the view, in biology, in early modern medicine and differently, in early modern philosophy, that living beings differ from the rest of the physical universe due to their possessing an additional âlife-forceâ, âvital principleâ, âentelechyâ, enormon or Ă©lan vital. Such definitions most often have an explicit pejorative dimension: vitalism is a primitive or archaic view, that has somehow survived the emergence of modern science (the latter being defined in many different ways, from demystified Cartesian reductionism to experimental medicine, biochemistry or genetics: Cimino and Duchesneau eds. 1997, Normandin and Wolfe eds. 2013). Such dismissive definitions of vitalism are meant to dispense with argument or analysis.
Curiously, the term has gained some popularity in English-language scholarship on early modern philosophy in the past few decades, where it is used without any pejorative dimension, to refer to a kind of âactive matterâ view, in which matter is not reducible to the (mechanistic) properties of size, shape and motion, possessing instead some internal dynamism or activity (see e.g. James 1999, Boyle 2018, Borcherding forthcoming). The latter meaning is close to what the Cambridge Platonist Ralph Cudworth termed âhylozoismâ, namely the attribution of life, agency or mind to matter, and he implicitly targeted several figures I shall mention here, notably Margaret Cavendish and Francis Glisson, for holding this view. However, one point I shall make in this entry is that when vitalism first appears by name, and as a self-designation, in the Montpellier School (associated with the Faculty of Medicine at the University of Montpellier, in the second half of the eighteenth century; thus vitalisme appears first, followed shortly thereafter by Vitalismus in German, with âvitalismâ appearing in English publications only in the early nineteenth century: Toepfer 2011), it is quite different from both the more âsupernaturalâ view described above â chiefly espoused by its rather obsessive opponents â and from the more neutral, but also de-biologized philosophical view (that of e.g. Cavendish or Conway who are, broadly speaking naturalists). Rather than appealing to a metaphysics of vital force, or of self-organizing matter, this version of vitalism, which I shall refer to as âmedical vitalismâ, seems to be more of a âsystemicâ theory: an attempt to grasp and describe top-level (âorganizationalâ, âorganismicâ, âholisticâ) features of living systems (Wolfe 2017, 2019).
In this entry I seek to introduce some periodization in our thinking about early modern (and Enlightenment) vitalism, emphasizing the difference between the seventeenth-century context and that of the following generations â culminating in the ideas of the Montpellier School. This periodization should also function as a kind of taxonomy or at least distinction between some basic types of vitalism. As I discuss in closing, these distinctions can cut across the texts and figures we are dealing with, differently: metaphysical vs. non-metaphysical vitalism, philosophical vs. medical vitalism, medical vs. âembryologicalâ vitalism, and so on. A difference I can only mention but not explore in detail is that the more medically grounded, âorganismicâ vitalism is significantly post-Cartesian while the more biological/embryological vitalism is, inasmuch as it is a dynamic, self-organizing matter theory, an extension of Renaissance ideas (chymiatry, Galenism and in general theories of medical spirits).
I examine successively vitalismâs Renaissance prehistory, its proliferation as âvital matter theoryâ in seventeenth-century England (in authors such as Cavendish, Conway and Glisson, with brief considerations on Harvey and van Helmont), and its mature expression in eighteenth-century Montpellier (notably with Bordeu and MĂ©nuret de Chambaud)
The transition to âpatienthoodâ, the contribution of the nursing assistant: a grounded theory study
The face of nursing is changing, as health-care organizations are looking to new assistant roles to support the registered nurse and potentially provide a source for apprenticeship toward registration. These developments are within a context of an existing assistant staff group, delivering much of the bedside care. Few studies have explored the dyadic relationship between nursing assistant and patient, despite the potential for their interactions to contribute to the patient experience. This study aimed to gain an understanding of patientsâ perceptions of the nursing assistant role using constructivist grounded theory. Constant comparison guided data collection and analysis, and 4 core categories emerged: expectation, observation, meaningful connections, and adaptation. Within these core categories, we suggest the assistant plays a part in how participants adapt from the known self to a self of patienthood and the overall patient experience. We conclude that there is a necessity to understand more fully the dyadic relationship between patients and nursing assistants
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
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
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
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