1,318 research outputs found

    Steady-state dynamics and effective temperatures of quantum criticality in an open system

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    We study the thermal and non-thermal steady state scaling functions and the steady-state dynamics of a model of local quantum criticality. The model we consider, i.e. the pseudogap Kondo model, allows us to study the concept of effective temperatures near fully interacting as well as weak-coupling fixed points. In the vicinity of each fixed point we establish the existence of an effective temperature --different at each fixed point-- such that the equilibrium fluctuation-dissipation theorem is recovered. Most notably, steady-state scaling functions in terms of the effective temperatures coincide with the equilibrium scaling functions. This result extends to higher correlation functions as is explicitly demonstrated for the Kondo singlet strength. The non-linear charge transport is also studied and analyzed in terms of the effective temperature.Comment: 5 pages, 4 figures; Supplementary Material (7 pages, 1 figure

    A novel diblock copolymer of (monomethoxy poly [ethylene glycol]-oleate) with a small hydrophobic fraction to make stable micelles/polymersomes for curcumin delivery to cancer cells

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    Curcumin is a potent natural anticancer agent, but its effectiveness is limited by properties such as very low solubility, high rate of degradation, and low rate of absorption of its hydrophobic molecules in vivo. To date, various nanocarriers have been used to improve the bioavailability of this hydrophobic biomaterial. This study investigates the encapsulation of curcumin in a novel nanostructure of monomethoxy poly(ethylene glycol)-oleate (mPEG-OA) and its anticancer effect. Tests were done to determine the critical micelle concentration (CMC), encapsulation efficiency, drug-loading efficiency, and cytotoxicity (against U87MG brain carcinoma cells and HFSF-PI3 cells as normal human fibroblasts) of some nanodevice preparations. The results of fluorescence microscopy and cell-cycle analyses indicated that the in vitro bioavailability of the encapsulated curcumin was significantly greater than that of free curcumin. Cytotoxicity evaluations showed that half maximal inhibitory concentrations of free curcumin and curcumin-loaded mPEG-OA for the U87MG cancer cell line were 48 μM and 24 μM, respectively. The Annexin-V-FLUOS assay was used to quantify the apoptotic effect of the prepared nanostructures. Apoptosis induction was observed in a dose-dependent manner after curcumin-loaded mPEG-OA treatments. Two common self-assembling structures, micelles and polymersomes, were observed by atomic force microscopy and dynamic light scat­tering, and the abundance of each structure was dependent on the concentration of the diblock copolymer. The mPEG-OA micelles had a very low CMC (13.24 μM or 0.03 g/L). Moreover, atomic force microscopy and dynamic light scattering showed that the curcumin-loaded mPEG-OA polymersomes had very stable structures, and at concentrations 1,000 times less than the CMC, at which the micelles disappear, polymersomes were the dominant structures in the dispersion with a reduced size distribution below 150 nm. Overall, the results from these tests revealed that this nanocarrier can be considered as an appropriate drug delivery system for delivering curcumin to cancer cells. © 2014 Erfani-Moghadam et al

    Analytic height correlation function of rough surfaces derived from light scattering

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    We derive an analytic expression for the height correlation function of a rough surface based on the inverse wave scattering method of Kirchhoff theory. The expression directly relates the height correlation function to diffuse scattered intensity along a linear path at fixed polar angle. We test the solution by measuring the angular distribution of light scattered from rough silicon surfaces, and comparing extracted height correlation functions to those derived from atomic force microscopy (AFM). The results agree closely with AFM over a wider range of roughness parameters than previous formulations of the inverse scattering problem, while relying less on large-angle scatter data. Our expression thus provides an accurate analytical equation for the height correlation function of a wide range of surfaces based on measurements using a simple, fast experimental procedure.Comment: 6 pages, 5 figures, 1 tabl

    Serum hyaluronate as a non-invasive marker of hepatic fibrosis and inflammation in HBeAg-negative chronic hepatitis B

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    Background: HBV infection is a serious global heath problem. It is crucial to monitor this disease more closely with a non-invasive marker in clinical trials. We aimed to evaluate the predictive value of serum hyaluronate for the presence of extensive liver fibrosis and inflammation. Methods: 28 healthy volunteers and 65 patients with HBeAg negative chronic hepatitis B were enrolled. Liver biopsies scored according to Ishak system. Association of serum hyaloronate with liver fibrosis and inflammation were assessed, and cut off points for serum hyaluronate levels were identified by receiver operating characteristics (ROC) curves and their values for prediction of fibrosis and inflammation were assessed. Results: In patients with CHB serum hyaluronate had the most significant correlation and predictive values for the liver fibrosis and inflammation comparing to the other variables. At the cut off point of 126.4 ngm/ml it could discriminate extensive fibrosis from milder ones with sensitivity of 90.9% and specificity of 98.1%. With the same value it could discriminate extensive inflammation from their milder counterparts with sensitivity of 63.6% and specificity of 92.6%. Conclusion: Serum hyaluronate was the best predictor of extensive liver fibrosis and inflammation and it could discriminate subgroups of patients with chronic hepatitis B. It could be used as a non-invasive test to monitor these patients more closely with developing anti viral agents in clinical trials

    Lamivudine resistance in Iranian chronic hepatitis B patients

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    Background and objectives: Lamivudine therapy for chronic hepatitis B (CHB) is associated with resistance. This study aimed to analyze the response, the incidence of LAM resistance, and different viral mutational patterns of Lamivudine therapy. Study design: CHB patients (n=31) who had not previously received interferon or a nucleoside analogue, received Lamivudine once daily for a minimum of E12 months and followed. All patients were tested for presence of mutation in YMDD motif of viral polymerase gene at the end of the first year of treatment, and if indicated in rising alanine aminotransferase (ALT) or HBVDNA titer. Polymerase chain reaction along with restriction fragment length polymorphism (PCR-RFLP) method was used to detect mutations in YMDD motif. Results: The mean age of patients was 45.2 (SD 13.5) years. The mean follow-up period of patients was 45.5 (21.9) months. Seventeen patients (54.8) had mutations, and 45.2 of subjects were sensitive to LAM. Mean time of mutation detection after treatment was 45.5 (SD 25.3) months. The distribution of YMDD status was: 32.3 YIDD, 3.2 YSDD, 12.9 YVDD, and 6.5 YVDD/ YIDD. The mean age, pretreatment HBeAg negativity, and high HBVDNA titer at time of mutation had significant statistical association with occurrence of YMDD mutants (PV= 0.009, 0.032, 0.049), respectively. Conclusions: Lamivudine-resistant mutation is common in CHB patients. Regarding different mutant strains as identified in this study, is necessary for develop more useful treatment strategies, especially in patients without YMDD mutation and high HBVDNA titer, analysis for possible new mutants should be performed. Copyright © 2010, Shiraz E Medical Journal. All rights reserved

    Assessment of digestive enzymes activity during the fry development of rainbow trout, Oncorhynchus mykiss: from hatching to primary stages after yolk sac absorption

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    The aim of this study was to determine the activity of digestive enzymes during the fry development of Rainbow trout ( Oncorhynchus mykiss ), which has a remarkable role in food digestion and absorption in the first feeding. The assessment of digestive enzymes activity of gastric (pepsin), pancreatic (trypsin, chymotrypsin, α-amylase and lipase) and intestinal (alkaline phosphatase) revealed that enzymes were available on the first day after hatching (DAH) but their activity showed no significant difference from hatching to day 12 (P > 0.05). An increased activity was seen between 12 and 18 DAH and this activity was significantly higher than the first 12 days (P 0.05). These results could be used as a basis for formulating a suitable feeding and also selecting the best time for starting the feeding so that optimum nutritional values and cost-effectiveness are achieved

    The study of factors associated with pregnancy outcomes in patients with systemic lupus erythematosus

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    Objectives: Systemic lupus erythematosus (SLE) is an autoimmune disease that can lead to unfavorable pregnancy complications in women. This study aimed to evaluate the factors associated with pregnancy outcomes in patients with SLE. Results: Fifty-nine pregnant women with SLE (121 pregnancies) participated in this retrospective cohort study. The mean age of the patients was 33.74 ± 3.80 years (range 21 to 48 years). Fetal loss occurred in 43.8 of pregnancies. The most common laboratory findings in SLE patients were antinuclear antibody (81.4) and anti-ds DNA positivity (54.2). High levels of C-reactive protein (CRP) during pregnancy, renal involvement, anti-double-stranded DNA positivity, anti-phospholipid antibody (APA) positivity and younger age at disease onset were significantly correlated with unfavourable pregnancy outcomes. A significant difference was observed between duration of SLE and low birth weight (P = 0.003), pre-eclampsia (P = 0.012) and still birth (P = 0.036). High CRP, APA positivity, anti-dsDNA positivity and kidney involvement were predictors of adverse pregnancy outcomes in SLE patients. Renal involvement increased risk of pregnancy with complication 8.5 times (OR = 8.5, 95 CI 1.396-63.373, P = 0.017). Antiphospholipid syndrome (APS) also was associated with an odds ratio of 5.18 (95 CI 1.681-13.647, P = 0.001). © 2020 The Author(s)
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