709 research outputs found
Two-loop perturbative corrections to the constrained effective potential in thermal QCD
In this paper, we compute the constrained QCD effective potential up to
two-loop order with finite quark mass and chemical potential. We present the
explicit calculations by using the double line notation and analytical
expressions for massless quarks are obtained in terms of the Bernoulli
polynomials or Polyakov loops. Our results explicitly show that the constrained
QCD effective potential is independent on the gauge fixing parameter. In
addition, as compared to the massless case, the constrained QCD effective
potential with massive quarks develops a completely new term which is only
absent when the background field vanishes. Furthermore, we discuss the relation
between the one- and two-loop constrained effective potential. The surprisingly
simple proportionality that exists in the pure gauge theories, however, is in
general no longer true when fermions are taken into account. On the other hand,
for high baryon density and low temperature , in the massless limit,
we do also find a similar proportionality between the one- and two-loop
fermionic contributions in the constrained effective potential up to .Comment: 36 pages, 5 figs, final version in JHE
Real-time hard-thermal-loop gluon self-energy in a semiquark-gluon plasma
In the real time formalism of the finite-temperature field theory, we compute
the one-loop gluon self-energy in a semi-quark-gluon plasma (QGP) where a
background filed has been introduced for the vector potential,
leading to a non-trivial expectation value for the Polyakov loop in the
deconfined phase. Explicit results of the gluon self-energies up to the
next-to-leading order in the hard-thermal-loop approximation are obtained. We
find that for the retarded/advanced gluon self-energy, the corresponding
contributions at next-to-leading order are formally analogous to the well-known
result at where the background field modification on the Debye
mass is entirely encoded in the second Bernoulli polynomials. The same feature
is shared by the leading order contributions in the symmetric gluon self-energy
where the background field modification becomes more complicated, including
both trigonometric functions and the Bernoulli polynomials. These contributions
are non-vanishing and reproduce the correct limit as .
In addition, the leading order contributions to the retarded/advanced gluon
self-energy and the next-to-leading order contributions to the symmetric gluon
self-energy are completely new as they only survive at . Given
the above results, we explicitly verify that the Kubo-Martin-Schwinger
condition can be satisfied in a semi-QGP with non-zero background field.Comment: final version published in PR
Standardization of Syndrome Differentiation Defined by Traditional Chinese Medicine in Operative Breast Cancer: A Modified Delphi Study
Objective. The aim of this study was to establish the standardization of syndrome differentiation of operative breast cancer treated with Traditional Chinese Medicine (TCM) by the modified Delphi method. Method. A literature search for standardization of syndrome differentiation of operative breast cancer was conducted and eligible articles were identified in indexed databases from 1982 to 2013. We carried out two rounds of investigation between March and October 2013 and organized 20 experts who focused on TCM or integrative medicine in breast cancer research. Experts’ judgments were collected via posted questionnaires or e-mail. A final evaluation was carried out after the end of both rounds. Result. The response ratio of the 1st round investigation reached 100%, and two experts were excluded due to the uncompleted questionnaire. The 2nd round investigation was completed by 18 experts in the 1st round panel board. In both rounds, the experts agreed that the stage of breast cancer defined by TCM could be divided into the perioperation period, the perichemotherapy period, the periradiotherapy period, and the consolidation period. Conclusion. We identified the feasibility and reasonability to establish the standardization of syndrome differentiation of operative breast cancer. According to the suggestions from experts in our Delphi study, we preliminarily established the TCM standard of syndrome differentiation based on different treatment stages of operative breast cancer
Polystyrene-b-poly(oligo(ethylene oxide) monomethyl ether methacrylate)-bpolystyrene triblock copolymers as potential carriers for hydrophobic drugs
A simple and effective method is introduced to synthesize a series of polystyrene-b-poly(oligo(ethylene oxide) monomethyl ether methacrylate)-b- polystyrene (PSt-b-POEOMA-b-PSt) triblock copolymers. The structures of PSt-b-POEOMA-b-PSt copolymers were characterized by Fourier-transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (1H NMR) spectroscopy. The molecular weight and molecular weight distribution of the copolymer were measured by gel permeation chromatography (GPC). Furthermore£ the self-assembling and drug-loaded behaviours of three different ratios of PSt-b-POEOMA-b-PSt were studied. These copolymers could readily self-assemble into micelles in aqueous solution. The vitamin E-loaded copolymer micelles were produced by the dialysis method. The micelle size and core-shell structure of the block copolymer micelles and the drug-loaded micelles were confirmed by dynamic light scattering (DLS) and transmission electron microscopy (TEM). The thermal properties of the copolymer micelles before and after drug-loaded were investigated by different scanning calorimetry (DSC). The results show that the micelle size is slightly increased with increasing the content of hydrophobic segments and the micelles are still core-shell spherical structures after drug-loaded. Moreover, the glass transition temperature (Tg) of polystyrene is reduced after the drug loaded. The drug loading content (DLC) of the copolymer micelles is 70%-80% by ultraviolet (UV) photolithography analysis. These properties indicate the micelles self-assembled from PSt-b- POEOMA-b- PSt copolymers would have potential as carriers for the encapsulation of hydrophobic drugs
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