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Background Photodynamic therapy (PDT) is an attractive modality for the treatment of BCC, based on its generally favorable efficacy, adverse effect profile and its excellent cosmetic outcome. Objectives The purpose of the study is to compare the efficacy and cosmetic outcome of photodynamic therapy with topical 5-aminolaevulinic acid (ALA-PDT) vs. simple excision surgery for superficial and nodular basal cell carcinoma (BCC). Methods A total of 72 patients, 32 with 48 lesions, were treated with ALA- PDT, and 40 with 46 lesions treated by excision were included in this prospective, comparative, controlled, clinical study. The patients have been followed for 16-37 months (mean 25 months). The PDT was performed in combination with 5-aminolaevulinic acid twice, one month apart. Surgical excision was performed under local anesthesia with a 3-mm margin, followed by histological examination. The cosmetic outcome was evaluated by the physician according to a 4-point scale. Results Overall 94 BCC were treated. Complete healing rates did not differ significantly between groups, P = 0.64 (46/48 [95.83%] lesions treated with PDT vs. 44/46 [95.65%] lesions with surgery). In the first 12 months of follow-up, 4 lesions had recurred, 2 of which were in the PDT group while 2 lesions after surgery. The mean follow-up was 25 months. The recurrence rate in the ALA-PDT group was 4.16% vs. 4.34% in the surgery group, p = 0.64. The cosmetic outcome was superior for ALA-PDT at all time points. At 12 months, 100% lesions treated with ALA-PDT had an excellent or good cosmetic outcome, according to the investigator, compared with 88.86% with surgery, P = 0.01. Conclusion ALA-PDT offers a similarly high efficacy, and a better cosmetic outcome than simple excision surgery in the treatment of BCC. [ABSTRACT FROM AUTHOR]

Brown adipose tissue mitochondria express the unique thermogenic uncoupling protein-1. Recently, brown adipocyte progenitors have been identified in the CD34+ cell population of human skeletal muscle. The aims of this study were firstly to determine if obesity and diabetes have altered amounts of muscle brown adipocyte progenitors and, secondly, to establish if the latter are correlated with clinical parameters of obesity and diabetes. Body mass index (BMI), plasma glucose, insulin, cholesterol and triglycerides as well as homeostasis model assessment were measured in lean (n=10), obese (n=18) and obese-diabetic (n=15) subjects and muscle biopsies were taken from the rectus abdominus. CD34 being also expressed on endothelial cells, we measured CD31, another endothelial marker, and expressed the brown adipocyte progenitors, as the CD34/CD31 mRNA ratio. The latter was significantly reduced in the obese vs lean subjects suggesting a smaller pool of brown adipocyte progenitors. More strinkingly, for lean and obese subjects negative correlations were observed between the CD34/CD31 mRNA ratios and BMI, fasting insulin levels and homeostasis model assessment. These correlations highlight the potential physiological relevance of the muscle CD34/CD31 mRNA ratio. [ABSTRACT FROM AUTHOR]

We consider the transport and the noise characteristic in the case of a triple quantum dots T-shape system where two of the dots form a two-level system and the other works in a detector-like setup. Our theoretical results are obtained using the equation of motion method for the case of zero and finite on-site Coulomb interaction in the detector dot. We present analytic results for the electronic Green's functions in the system's component quantum dots, and we used numerical calculations to evaluate the system's transport properties. The transport trough the T-shaped system can be controlled by varying the coupling between the two-level system dots or the coupling between the detector dot and the exterior electrodes. The system's conductance presents Fano dips for both strong (fast detector) and weak coupling (slow detector) between the detector dot and the external electrodes. Due to stronger electronic correlations the noise characteristics in the case of a slow detector are much higher. This setup may be of interest for the practical realization of qubit states in quantum dots systems. [ABSTRACT FROM AUTHOR]

We revisited the scaling behavior of the transport properties of a quantum dot system described by the spin-1/2 Anderson model using analytical methods. In the low temperature limit, we show that the conductance has a universal behavior with universality between temperature and bias. We compare this result with the empirical formula used to fit the experimental data for conductance in the case of the equilibrium transport through a single channel quantum dot. In the high temperature limit, the conductance obtained from the Anderson model is compared with previous results obtained from the Kondo model. The universal behavior is present also in the high temperature limit. These results are in good agreement with the renormalization group calculations. [ABSTRACT FROM AUTHOR]

We study the quantum Anderson model in the presence of the finite Coulomb interaction U using the t-matrix approximation. The energy of the d-electron level increases as Uln ( U/ πΔ) for strong Coulomb interaction U and finite level-width Δ. In the case of small U/Δ parameter this approximation gives the results from the perturbation theory. The spin susceptibility is calculated as a function of U and compared with the results obtained by renormalized perturbation approximation. The results can be used to study the effect of the finite Coulomb interaction in the quantum transport. [ABSTRACT FROM AUTHOR]

We study the linear conductance in quantum dot with spin–orbit interaction coupled to Fermi liquid leads with a power-low density of states. The conductance at zero temperature is calculated as a function of the power exponent from the density of state ρ( ω)∼| ω− E F | r at the Fermi energy E F and the different energy rates. The phase shift of the conduction electrons is also r-dependent. The model can be used in the study of the quantum phase transition. [ABSTRACT FROM AUTHOR]

We consider the quantum critical properties of a disordered two dimensional Bose gas based on the renormalization group approach. To account for disorder, we consider that the Bose gas interacts with an external random field. The system’s behavior in the critical region of the quantum phase transition is obtained in the universality class z=2 and includes contributions beyond the Gaussian approximation by considering interactions between bosonic degrees of freedom. The evaluation of the system’s conductivity close to the transition point proves the occurrence of a nonzero conductivity (metallic-like) state in the system in the ω=0 and T→0 K limit. [ABSTRACT FROM AUTHOR]

We consider the influence of the temperature on the normal state in a one-dimensional ferromagnetic phase transition. This transition occurs only at T = 0 in the Luttinger model but the proximity of the critical point can give drastic effects on the physical properties of the normal phase Using the flow equations of the Renormalization group and a Φ4model with a dynamical critical exponent z = 2, we calculated the temperature dependence of coherence length, magnetic susceptibility, and specific heat. [ABSTRACT FROM AUTHOR]

We consider the influence of temperature on the critical behavior of a weakly interacting three dimensional Bose system. Using the flow equations of the Renormalization Group and a Φ4 model with dynamical critical exponent z = 2, we calculated the critical exponent ν, and the thermodynamical parameters near the critical temperature, taking in consideration the quantum effects. The quantum effects considered using this method gives for ν the value 0.75, which is close to the value 0.73 obtained by the polynomial method. The critical temperature shift ΔTc was obtained, in the lowest-order approximation, and turns out to be proportional to the scattering length. [ABSTRACT FROM AUTHOR]

We consider the influence of temperature on the critical behavior of the weakly interacting three-dimensional Bose system. Using the flow equations of the Renormalization group and a Φ4 model with dynamical critical exponent z = 2, we calculated the critical exponent ν, and the thermodynamic parameters near the critical temperature, taking into consideration the quantum effects. The quantum effects considered in this method gives ν the value 0.75, which is close to the value 0.73 obtained by the polynomial method. The critical temperature shift ΔTc was obtained, in the lowest order approximation, proportional to the scattering length. [ABSTRACT FROM AUTHOR]

We study the behavior of the nonzero temperature quantum nonlinear sigma model in d = 2 dimensions at finite temperatures in the presence of the damping term. Using the renormalization group (RG) method we calculated the effect of the finite temperature on the magnetic coherence length and the damping of the fluctuations. The results have been used to calculate the relaxation rates from nuclear magnetic resonance, which have been analyzed phenomenologically by different authors in order to get the phase diagram in the doped cuprate superconductors. Our calculations showed a good agreement with the experimental data, but we also evaluated the corrections which appear due to a more accurate analysis performed using the RG method. [ABSTRACT FROM AUTHOR]

We study the behavior of the finite temperature quantum nonlinear sigma model in two dimensions in the presence of the damping of the form f (|θ n |) = γ| ω n |α, where α satisfies α ≥ 1. The analytical calculations will be performed using α=2 and the results will be compared with the standard results obtained for the standard quantum nonlinear sigma model. The behavior of such a system is connected with the pseudogap which appears in the normal state of the cuprate superconductors. [ABSTRACT FROM AUTHOR]

We calculate the finite temperature correlation function, the coherence length and the critical temperature for a two-dimensional (2D) bosonic system, which presents the quasicondensation (a finite number of occupied states with p0≠0 momentum) effect at very low temperatures. This state, discovered experimentally, appear below a critical temperature for a finite number of particles. [ABSTRACT FROM AUTHOR]

We analyze the non-Fermi liquid behavior in the proximity of the quantum phase transition induced by the strong polarization of the electrons due to local magnetic moments in Ni xPd1- x alloys. We use the renormalization group approach introduced by Hertz–Mi11is–Moriya (HMM) to estimate the temperature dependence of the electrical resistivity for the case of three dimensional itinerant ferromagnets. We study two different cases, namely, the clean and disordered ferromagnets, and argue that at the present time more experimental data are needed to decide if the HMM theory can accurately describe the physical properties in Ni xPd1- x alloys. [ABSTRACT FROM AUTHOR]

We analyze the two-dimensional antiferromagnet with a quantum disordered ground state and a gap to bosonic excitations with finite spin. The zero temperature ( T = 0) quantum phase transition is studied, and the finite temperature effects are also considered in the low temperature approximation of the Renormalization Group Method. The violation of the universality expected for d = 2 system has been shown to be logarithmic for T = 0 and T ≠ 0. We showed that chemical potential and the ground state energy depends on the interaction parameters at T = 0 and T ≠ 0. but this dependence is logarithmic. [ABSTRACT FROM AUTHOR]

The effective mass in heavy fermion materials is calculated, taking into consideration both the antiferromagnetic and ferromagnetic fluctuations. The temperature and the proximity of a quantum critical point effects are considered. The effective mass diverges at the quantum critical point and in the zero temperature limit. [ABSTRACT FROM AUTHOR]

We consider the fluctuation conductivity in the critical region of a disorder induced quantum phase transition in layered d-wave superconductors. We specifically address the fluctuation contribution to the system’s conductivity in the limit of large (quasi-two-dimensional system) and small (quasi-three-dimensional system) separation between adjacent layers of the system. Both in-plane and c-axis conductivities were discussed near the point of insulator-superconductor phase transition. The value of the dynamical critical exponent, z = 2, permits a perturbative treatment of this quantum phase transition under the renormalization group approach. We discuss our results for the system conductivities in the critical region as function of temperature and disorder. [ABSTRACT FROM AUTHOR]

We showed that in a d-wave two-dimensional superconductor the disorder given by non-magnetic impurities at low temperature leads to a non-Fermi behavior for the normal state. The transition is similar to the superconductor–insulator transition in a model with a dissipative term. [ABSTRACT FROM AUTHOR]

We applied the Renormalization Group method at finite temperature to reconsider the two-dimensional dilute Bose gas. The general flow equations are obtained for the case of arbitrary dimensions, and by considering the two-dimensional limit, we estimate the value of the critical temperature, coherence length and specific heat. The value of the critical temperature is in agreement with previous calculations performed using the t-matrix method. The coherence length and the specific heat present a non-universal behavior, a logarithmic temperature dependence in the critical region being identified. [ABSTRACT FROM AUTHOR]

We propose a model for the explanation of the non-Fermi behavior near the ferromagnetic quantum phase transition. The scaling equations have been used to calculate the specific heat and we showed that the quantum effects are responsible for the T ln T term from the specific heat. The results are in agreement with recent experimental data obtained in the Ni xPd1 − x system. The relation with the other approaches was also discussed. [ABSTRACT FROM AUTHOR]

We used the Renormalization Group (RG) method in the Hertz–Millis version to study the quantum phase transition of the itinerant-electron ferromagnet. Near the quantum phase transition point the system present a non-Fermi behavior in agreement with the experimental results. The importance of long-range interactions considered by Belitz–Kirkpatrick–Vojta was taken into consideration, showing the importance of the marginal parameters. [ABSTRACT FROM AUTHOR]

We derive the expression of the specific heat of a three-dimensional semimetal near a zero-temperature phase transition with dynamic exponent z. The result showed the occurrence of a non-Fermi behavior for z = 3, according to the general conjecture that the systems with d = z may present a T ln T contribution in the specific heat, which is typical for the non-Fermi behavior. [ABSTRACT FROM AUTHOR]

Composite SiO2—iron oxide materials were prepared by three experimental procedures. In the first case, the iron oxides were precipitated during a sol-gel process. In the second case, a SiO2 matrix was initially obtained, and the iron oxides were formed by thermal treatment after impregnation of a soluble Fe2+ salt in the previously processed matrix. In the third method, ferrite powders, prepared by wet chemical method, were embedded into a SiO2 based sol-gel matrix. Materials with convenient porosity and nano-sized iron oxide content could be prepared using the mentioned methods. The prepared composite has been tested for arsenic(V) removal. [ABSTRACT FROM AUTHOR]

We investigate the fluctuation contribution to the specific heat of a two-dimensional superconductor with a non-Fermi normal state described by a Anderson Green's function G(k, iω) = ω[sup -α, sub c]/(iω - ε[sub k])[sup 1-α]. The specific heat corrections contain a term proportional to (T[sup 2α] -T[sup 2α, sub c])[sup -l] and another logarithmic one. We define a coherence length as function of the non-Fermi parameter α, which shows that a crossover study between BCS and Bose-Einstein condensation is possible by varying the non-Fermi parameter α. [ABSTRACT FROM AUTHOR]

The electronic self-energy due to the electron–spin fluctuation interaction is calculated using the one loop approximation for a two-dimensional system and quasi-two-dimensional (anisotropic) model. We analyzed the relevance of the diffusive modes and the temperature dependence of the magnetic correlation length for a possible temperature dependence of the pseudogap. [ABSTRACT FROM AUTHOR]

We studied the influence of the electron–boson interaction (hybridization) on the bosonic spectrum in the case of a two dimensional (2D) electronic system. The boson dispersion is affected by this interaction and we showed that for a constant density of states the wavevector dependence is quadratic for qv F/4 T ≪ 1, and the imaginary part is small for qv F/4 T ≫ 1. However, the 2D electronic system presents a van Hove density of states, and we considered this energy dependence in the calculation of the bosonic energy spectrum. The real part becomes logarithmic dependent on the wavevector and the imaginary part can be neglected if qv F ∼ E F or 2 E c ∼ z, for qv F/4 T ≫ 1. [ABSTRACT FROM AUTHOR]

We consider a two-dimensional (2D) Fermi liquid with attraction in the d channel. The critical temperature, the order parameter at T = 0 and the temperature dependence of the order parameter have been calculated analytically for a constant, an ɛr-energy dependent, and a van Hove density of states. [ABSTRACT FROM AUTHOR]

The gels which are precursors of TiO2 porous materials are prepared by the controlled hydrolysis-condensation of titanium isopropoxide by polymeric method. In the present work, a study of the influence of different experimental conditions (water/alkoxide ratio, solvent/alkoxide ratio and temperature) on the structure and texture of the polymeric gels obtained with the same type of alkoxide has been investigated. The structural and textural modifications for the unsupported materials have been detected using DTA/TGA, XRD, specific surface area and pore size computerized measurements. The optical properties of the supported materials deposited on silicon wafers have been investigated using ellipsometric method. Supported and unsupported porous materials with different structure and texture have been obtained depending on different experimental and thermal treatment conditions. [ABSTRACT FROM AUTHOR]

The gels which are precursors of TiO2 porous materials are prepared by the controlled hydrolysis-condensation of titanium isopropoxide by polymeric method. In the present work, a study of the influence of different experimental conditions (water/alkoxide ratio, solvent/alkoxide ratio and temperature) on the structure and texture of the polymeric gels obtained with the same type of alkoxide has been investigated. The structural and textural modifications for the unsupported materials have been detected using DTA/TGA, XRD, specific surface area and pore size computerized measurements. The optical properties of the supported materials deposited on silicon wafers have been investigated using ellipsometric method. Supported and unsupported porous materials with different structure and texture have been obtained depending on different experimental and thermal treatment conditions. [ABSTRACT FROM AUTHOR]

We discussed the validity of the Abrikosov–Gorkov formula for the description of the decreasing of Tc in the d-pairing superconductors. A scaling behavior of Tc with the concentration of nonmagnetic impurities has been obtained in the unitary limit scattering. The average of the impurities has also been discussed in different models and we showed that the validity of the procedure is sensitive to the ratio R = 2Δ(0)/ Tc. [ABSTRACT FROM AUTHOR]

We used the flow equation method to obtain from the electron–magnon Hamiltonian an effective electron–electron Hamiltonian with renormalized single-particle energy. In the Cooper channel the electron–electron interaction was found to be attractive. The energy scale of the superconducting critical temperature is determined by the spin splitting, which gives rise to the realistic energy scale. [ABSTRACT FROM AUTHOR]

The critical temperature of a superconductor with a non-Fermi liquid ground state has been calculated. The density of states has two different forms and is energy dependent. The critical values of the coupling factor λ were calculated. The constant density of states results are obtained as particular cases. These results are an extension of the work done by Grosu et al. [ Phys. Rev. B 56, 8298 (1997)]. [ABSTRACT FROM AUTHOR]