59 research outputs found
Universal logarithmic correction to Renyi (Shannon) entropy in generic systems of critical quadratic fermions
The Renyi (Shannon) entropy, i.e., Re-alpha(Sh), of the ground state of quantum systems in local bases normally show a volume-law behavior. For a subsystem of quantum chains at a critical point there is an extra logarithmic subleading term with a coefficient which is universal. In this paper we study this coefficient for generic time-reversal translational invariant quadratic critical free fermions. These models can be parametrized by a complex function which has zeros on the unit circle. When the zeros on the unit circle do not have degeneracy and there is no zero outside of the unit circle we are able to classify the coefficient of the logarithm. In particular, we numerically calculate the Renyi (Shannon) entropy in a configuration basis for a wide variety of these models and show that there are two distinct classes. For systems with U(1) symmetry the coefficient is proportional to the central charge, i.e., one half of the number of points that one can linearize the dispersion relation of the system; for all the values of a with transition point at alpha = 4. For systems without this symmetry, when alpha > 1, this coefficient is again proportional to the central charge. However, the coefficient for alpha <= 1 is a new universal number. Finally, by using the discrete version of the Bisognano-Wichmann modular Hamiltonian of the Ising chain we show that these coefficients are universal and dependent on the underlying CFT
Universal logarithmic correction to Rényi (Shannon) entropy in generic systems of critical quadratic fermions
The R\'enyi (Shannon) entropy, i.e. , of the ground state of
quantum systems in local bases normally show a volume-law behavior. For a
subsystem of quantum chains at critical point there is an extra logarithmic
subleading term with a coefficient which is universal. In this paper we study
this coefficient for generic time-reversal translational invariant quadratic
critical free fermions. These models can be parameterized by a complex function
which has zeros on the unit circle. When the zeros on the unit circle do not
have degeneracy and there is no zero outside of the unit circle we are able to
classify the coefficient of the logarithm. In particular, we numerically
calculate the R\'enyi (Shannon) entropy in configuration basis for wide variety
of these models and show that there are two distinct classes. For systems with
symmetry the coefficient is proportional to the central charge, i.e. one
half of the number of points that one can linearize the dispersion relation of
the system; for all the values of with transition point at .
For systems without this symmetry, when this coefficient is again
proportional to the central charge. However, the coefficient for
is a new universal number. Finally, by using the discrete version of
Bisognano-Wichmann modular Hamiltonian of the Ising chain we show that these
coefficients are universal and dependent on the underlying CFT.Comment: v2: 16 pages, 10 figures published versio
A review of potential suggested drugs for coronavirus disease (COVID-19) treatment
The latest pandemic, coronavirus disease-2019 (COVID-19), is associated with high prevalence and easy transmission, which is expanding globally with no conventional treatment or vaccine. The new virus revealed 79 and 50 genomic similarities with severe acute respiratory syndrome coronavirus (SARS-CoV) and Middle East respiratory syndrome coronavirus (MERS-CoV), respectively. Accordingly, since the disease resists testing and adopting new therapeutics, repositioning pre-existing drugs may present a fast and attractive strategy with known safety, characteristics, and dosage used. However, they are not specific and targeted. Therefore, several drugs have been investigated for their efficacy and safety in the treatment of COVID-19; most of them are undergoing clinical trials. This article summarizes clinical investigations of potential therapeutic drugs used as COVID-19 therapy. Subsequently, it prepares a pattern of results and therapeutic targets to help further experiment designs. We have investigated drugs as classified in the following three groups; 1) The drugs which computationally showed effectiveness (in silico) but needed further lab confirmations; 2) Emetine, Teicoplanin, and Nelfinavir have shown effectiveness in vitro; 3) The drugs currently under clinical trial. © 2021 Elsevier B.V
A review of potential suggested drugs for coronavirus disease (COVID-19) treatment
The latest pandemic, coronavirus disease-2019 (COVID-19), is associated with high prevalence and easy transmission, which is expanding globally with no conventional treatment or vaccine. The new virus revealed 79 and 50 genomic similarities with severe acute respiratory syndrome coronavirus (SARS-CoV) and Middle East respiratory syndrome coronavirus (MERS-CoV), respectively. Accordingly, since the disease resists testing and adopting new therapeutics, repositioning pre-existing drugs may present a fast and attractive strategy with known safety, characteristics, and dosage used. However, they are not specific and targeted. Therefore, several drugs have been investigated for their efficacy and safety in the treatment of COVID-19; most of them are undergoing clinical trials. This article summarizes clinical investigations of potential therapeutic drugs used as COVID-19 therapy. Subsequently, it prepares a pattern of results and therapeutic targets to help further experiment designs. We have investigated drugs as classified in the following three groups; 1) The drugs which computationally showed effectiveness (in silico) but needed further lab confirmations; 2) Emetine, Teicoplanin, and Nelfinavir have shown effectiveness in vitro; 3) The drugs currently under clinical trial. © 2021 Elsevier B.V
Intestinal protozoa in domestic cats (Carnivora: Felidae, felis catus) in northwestern iran: A cross-sectional study with prevalent of microsporidian and coccidian parasites
Background: In this study, some microsporidial and coccidian parasites were isolated from 103 domestic cats in the Meshkin Shahr area, northwestern Iran during the Jun 2014 to Jun 2015, and their genera were identified using parasitologicamethods with emphasis on their zoonotic importance. Methods: One hundred and three fecal samples of domestic cats were collected and preserved in formalin (10) and conserved in phosphate buffer saline solution, finally examined by microscopy after formalin-ether concentration and specific staining. Preservation in dichromate potassium (2.5) was performed for all coccidian positive samples and then sporulated coccidian oocysts were investigated. Results: The detected parasites were Isospora spp. 6/103(5.8). Microsporidian spores were identified in 46/103 (44.6) of all samples post-stained by the aniline blue staining method. Conclusion: Microsporidial infections were more prevalent in domestic cats. Further studies are needed in the identification of microsporidial spores isolated from infected cats. © 2019, Tehran University of Medical Sciences (TUMS). All rights reserved
The benefits of folic acid-modified gold nanoparticles in CT-based molecular imaging: radiation dose reduction and image contrast enhancement
X-ray computed tomography (CT) requires an optimal compromise between image quality and patient dose. While high image quality is an important requirement in CT, the radiation dose must be kept minimal to protect the patients from ionizing radiation-associated risks. The use of probes based on gold nanoparticles (AuNPs) along with active targeting ligands for specific recognition of cancer cells may be one of the balanced solutions. Herein, we report the effect of folic acid (FA)-modified AuNP as a targeted nanoprobe on the contrast enhancement of CT images as well as its potential for patient dose reduction. For this purpose, nasopharyngeal KB cancer cells overexpressing FA receptors were incubated with AuNPs with and without FA modification and imaged in a CT scanner with the following X-ray tube parameters: peak tube voltage of 130�KVp, and tube current�time products of 60, 90, 120, 160 and 250�mAs. Moreover, in order to estimate the radiation dose to which the patient was exposed during a head CT protocol, the CT dose index (CTDI) value was measured by an X-ray electrometer by changing the tube current�time product. Raising the tube current�time product from 60 to 250�mAs significantly increased the absorbed dose from 18�mGy to 75�mGy. This increase was not associated with a significant enhancement of the image quality of the KB cells. However, an obvious increase in image brightness and CT signal intensity (quantified by Hounsfield units HU) were observed in cells exposed to nanoparticles without any increase in the mAs product or radiation dose. Under the same Au concentration, KB cells exposed to FA-modified AuNPs had significantly higher HU and brighter CT images than those of the cells exposed to AuNPs without FA modification. In conclusion, FA-modified AuNP can be considered as a targeted CT nanoprobe with the potential for dose reduction by keeping the required mAs product as low as possible while enhancing image contrast. © 2017 Informa UK Limited, trading as Taylor & Francis Grou
The G2A Receptor Controls Polarization of Macrophage by Determining Their Localization Within the Inflamed Tissue
Macrophages are highly versatile cells, which acquire, depending on their microenvironment, pro- (M1-like), or antiinflammatory (M2-like) phenotypes. Here, we studied the role of the G-protein coupled receptor G2A (GPR132), in chemotactic migration and polarization of macrophages, using the zymosan-model of acute inflammation. G2A-deficient mice showed a reduced zymosan-induced thermal hyperalgesia, which was reversed after macrophage depletion. Fittingly, the number of M1-like macrophages was reduced in the inflamed tissue in G2A-deficient mice. However, G2A activation was not sufficient to promote M1-polarization in bone marrow-derived macrophages. While the number of monocyte-derived macrophages in the inflamed paw was not altered, G2A-deficient mice had less macrophages in the direct vicinity of the origin of inflammation, an area marked by the presence of zymosan, neutrophil accumulation and proinflammatory cytokines. Fittingly neutrophil efferocytosis was decreased in G2A-deficient mice and several lipids, which are released by neutrophils and promote G2A-mediated chemotaxis, were increased in the inflamed tissue. Taken together, G2A is necessary to position macrophages in the proinflammatory microenvironment surrounding the center of inflammation. In absence of G2A the macrophages are localized in an antiinflammatory microenvironment and macrophage polarization is shifted toward M2-like macrophages
Phenotypic and Genome-Wide Analysis of an Antibiotic-Resistant Small Colony Variant (SCV) of Pseudomonas aeruginosa
Small colony variants (SCVs) are slow-growing bacteria, which often show increased resistance to antibiotics and cause latent or recurrent infections. It is therefore important to understand the mechanisms at the basis of this phenotypic switch.One SCV (termed PAO-SCV) was isolated, showing high resistance to gentamicin and to the cephalosporine cefotaxime. PAO-SCV was prone to reversion as evidenced by emergence of large colonies with a frequency of 10(-5) on media without antibiotics while it was stably maintained in presence of gentamicin. PAO-SCV showed a delayed growth, defective motility, and strongly reduced levels of the quorum sensing Pseudomonas quinolone signal (PQS). Whole genome expression analysis further suggested a multi-layered antibiotic resistance mechanism, including simultaneous over-expression of two drug efflux pumps (MexAB-OprM, MexXY-OprM), the LPS modification operon arnBCADTEF, and the PhoP-PhoQ two-component system. Conversely, the genes for the synthesis of PQS were strongly down-regulated in PAO-SCV. Finally, genomic analysis revealed the presence of mutations in phoP and phoQ genes as well as in the mexZ gene encoding a repressor of the mexXY and mexAB-oprM genes. Only one mutation occurred only in REV, at nucleotide 1020 of the tufA gene, a paralog of tufB, both encoding the elongation factor Tu, causing a change of the rarely used aspartic acid codon GAU to the more common GAC, possibly causing an increase of tufA mRNA translation. High expression of phoP and phoQ was confirmed for the SCV variant while the revertant showed expression levels reduced to wild-type levels.By combining data coming from phenotypic, gene expression and proteome analysis, we could demonstrate that resistance to aminoglycosides in one SCV mutant is multifactorial including overexpression of efflux mechanisms, LPS modification and is accompanied by a drastic down-regulation of the Pseudomonas quinolone signal quorum sensing system
- …