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Abstract In this paper, we first construct thermofield double states for bosonic string theory in the light-cone gauge. We then obtain a coherent-thermal string state and a thermal-coherent string state. We use the covariance matrix approach to calculate the circuit complexity of coherent-thermal string states. In this approach, we generate the optimal geodesics by a horizontal string generator, and then obtain the circuit complexity using the length of the minimal geodesics in the group manifold.

Abstract Discrete-time quantum walks are known to exhibit exotic topological states and phases. Physical realization of quantum walks in a lossy environment may destroy these phases. We investigate the behaviour of topological states in quantum walks in the presence of a lossy environment. The environmental effects in the quantum walk dynamics are addressed using the non-Hermitian Hamiltonian approach. We show that the topological phases of the quantum walks are robust against moderate losses. The topological order in one-dimensional split-step quantum walk persists as long as the Hamiltonian respects exact $${{\mathcal {P}}}{{\mathcal {T}}}$$ P T -symmetry. Although the topological nature persists in two-dimensional quantum walks as well, the $${{\mathcal {P}}}{{\mathcal {T}}}$$ P T -symmetry has no role to play there. Furthermore, we observe topological phase transition in two-dimensional quantum walks that is induced by losses in the system.

We have studied the charged BTZ black holes in noncommutative spaces arising from two independent approaches. First, by using the Seiberg-Witten map followed by a dynamic choice of gauge in the Chern-Simons gauge theory. Second, by inducing the fuzziness in the mass and charge by a Lorentzian distribution function with the width being the same as the minimal length of the associated noncommutativity. In the first approach, we have found the existence of non-static and non-stationary BTZ black holes in noncommutative spaces for the first time in the literature, while the second approach facilitates us to introduce a proper bound on the noncommutative parameter so that the corresponding black hole becomes stable and physical. We have used a contemporary tunneling formalism to study the thermodynamics of the black holes arising from both of the approaches and analyze their behavior within the context.

Abstract We analyze certain aspects of BTZ black holes in massive theory of gravity. The black hole solution is obtained by using the Vainshtein and dRGT mechanism, which is asymptotically AdS with an electric charge. We study the Hawking radiation using the tunneling formalism as well as analyze the black hole chemistry for such system. Subsequently, we use the thermodynamic pressure-volume diagram to explore the efficiency of the Carnot heat engine for this system. Some of the important features arising from our solution include the non-existence of quantum effects, critical Van der Walls behaviour, thermal fluctuations and instabilities. Moreover, our solution violates the Reverse Isoperimetric Inequality and, thus, the black hole is super-entropic, perhaps which turns out to be the most interesting characteristics of the BTZ black hole in massive gravity.

One of the major difficulties of modern science underlies at the unification of general relativity and quantum mechanics. Different approaches towards such theory have been proposed. Noncommutative theories serve as the root of almost all such approaches. However, the identification of the appropriate passage to quantum gravity is suffering from the inadequacy of experimental techniques. It is beyond our ability to test the effects of quantum gravity thorough the available scattering experiments, as it is unattainable to probe such high energy scale at which the effects of quantum gravity appear. Here we propose an elegant alternative scheme to test such theories by detecting the deformations emerging from the noncommutative structures. Our protocol relies on the novelty of an opto-mechanical experimental setup where the information of the noncommutative oscillator is exchanged via the interaction with an optical pulse inside an optical cavity. We also demonstrate that our proposal is within the reach of current technology and, thus, it could uncover a feasible route towards the realization of quantum gravitational phenomena thorough a simple table-top experiment.

We study the correction of the energy spectrum of a gravitational quantum well due to the combined effect of the braneworld model with infinite extra dimensions and generalized uncertainty principle. The correction terms arise from a natural deformation of a semiclassical theory of quantum gravity governed by the Schrödinger–Newton equation based on a minimal length framework. The two fold correction in the energy yields new values of the spectrum, which are closer to the values obtained in the GRANIT experiment. This raises the possibility that the combined theory of the semiclassical quantum gravity and the generalized uncertainty principle may provide an intermediate theory between the semiclassical and the full theory of quantum gravity. We also prepare a schematic experimental set-up which may guide to the understanding of the phenomena in the laboratory.

Mutation in TP53 is a common genetic alteration in human cancers. Certain tumor associated p53 missense mutants acquire gain-of-function (GOF) properties and confer oncogenic phenotypes including enhanced chemoresistance. The colorectal cancers (CRC) harboring mutant p53 are generally aggressive in nature and difficult to treat. To identify a potential gene expression signature of GOF mutant p53-driven acquired chemoresistance in CRC, we performed transcriptome profiling of floxuridine (FUdR) treated SW480 cells expressing mutant p53R273H (GEO#: GSE77533). We obtained several genes differentially regulated between FUdR treated and untreated cells. Further, functional characterization and pathway analysis revealed significant enrichment of crucial biological processes and pathways upon FUdR treatment in SW480 cells. Our data suggest that in response to chemotherapeutics treatment, cancer cells with GOF mutant p53 can modulate key cellular pathways to withstand the cytotoxic effect of the drugs. The genes and pathways identified in the present study can be further validated and targeted for better chemotherapy response in colorectal cancer patients harboring mutant p53.

Almost all epithelial tumours contain cancer stem-like cells, which possess a unique property of self-renewal and differentiation. In oral cancer, several biomarkers including cell surface molecules have been exploited for the identification of this highly tumorigenic population. Implicit is the role of CD44 in defining CSCs but CD24 is not well-explored. Here we show that CD44highCD24low cells isolated from the oral cancer cell lines, not only express stem cell related genes but also exhibit Epithelial-to-Mesenchymal transition (EMT) characteristics. This CD44highCD24low population gives rise to all other cell types upon differentiation. Typical Cancer Stem Cell (CSC) phenotypes like increased colony formation, sphere forming ability, migration and invasion were also confirmed in CD44highCD24low cells. Drug transporters were found to be over-expressed in CD44highCD24low sub-population thereby contributing to elevated chemo-resistance. To validate our findings in-vivo, we determined the relative expression of CD44 and CD24 in clinical samples of OSCC patients. CD44 expression was consistently high whereas CD24 showed significantly lower expression in tumour tissues. Further, the gene expression profile of the CSC and non-CSC population unravels the molecular pathways which may contribute to stemness. We conclude that CD44highCD24low represents cancer stem-like cells in Oral Squamous Cell Carcinoma.

Expression of matrix metalloproteinase-1 (MMP-1), an interstitial collagenase, plays a major role in cellular invasion during development of gastric cancer, a leading cause of death worldwide. A single-nucleotide polymorphism (SNP) -1607 1G/2G site of the MMP-1 gene promoter has been reported to alter transcription level. While the importance's of other SNPs in the MMP-1 promoter have not yet been studied in gastric cancer, our aim was to investigate MMP-1 gene promoter polymorphisms and gastric cancer susceptibility in eastern Indian population. A total of 145 gastric cancer patients and 145 healthy controls were genotyped for MMP-1 -1607 1G/2G (rs1799750) by PCR-restriction fragment length polymorphism (RFLP), while MMP-1 -519 A/G (rs1144393), MMP-1 -422 T/A (rs475007), MMP-1 -340 T/C (rs514921) and MMP-1 -320 T/C (rs494379) were genotyped by DNA sequencing. A positive association was found with MMP-1 -422 T/A SNP that showed significant risk for regional lymph node metastasis (P = 0.021, Odd's ratio (OR) = 3.044, Confidence intervals (CI) = 1.187-7.807). In addition, we found a significant association with lower stomach tumor formation among gastric cancer patients for three adjacent polymorphisms near the transcriptional start sites of [MMP-1 -422 T/A (P = 0.043, OR = 2.182, CI = 1.03-4.643), MMP-1 -340 T/C (P = 0.075, OR = 1.97, CI = 0.94-4.158) and MMP-1 -320 T/C (P = 0.034, OR = 2.224, CI = 1.064-40731)]. MMP-1 level in patients' serum was correlated with MMP-1 promoter haplotypes conferring these three SNPs to evaluate the functional importance of these polymorphisms in lower stomach tumor formation and significant correlation was observed. Furthermore, MMP-1 -519 A/G polymorphism displayed poor cellular differentiation (P = 0.024, OR = 3.8, CI = 1.69-8.56) attributing a higher risk of cancer progression. In conclusion, MMP-1 proximal promoter SNPs are associated with the risk of lower stomach tumor formation and node metastasis in eastern Indian population.

The two dimensional set of canonical relations giving rise to minimal uncertainties previously constructed from a q-deformed oscillator algebra is further investigated. We provide a representation for this algebra in terms of a flat noncommutative space and employ it to study the eigenvalue spectrum for the harmonic oscillator on this space. The perturbative expression for the eigenenergy indicates that the model might possess an exceptional point at which the spectrum becomes complex and its PT-symmetry is spontaneously broken.

The aim of this study is to understand the mechanism of EGFR overexpression in head and neck squamous cell carcinoma (HNSCC). For this reason, expression/mutation of EGFR were analyzed in 30 dysplastic head and neck lesions and 148 HNSCC samples of Indian patients along with 3 HNSCC cell lines. In addition, deletion/methylation/mutation/expression of SH3GL2 (associated with EGFR degradation) and CDC25A (associated with dephosphorylation of EGFR) were analyzed in the same set of samples. Our study revealed high frequency of EGFR overexpression (66-84%), low frequency of gene amplification (10-32.5%) and absence of functional mutation in the dysplastic lesions and HNSCC samples. No correlation was found between protein overexpression and mRNA expression/gene amplification status of EGFR. On the other hand, frequent alterations (deletion/methylation) of SH3GL2 (63-77%) and CDC25A (37-64%) were seen in the dysplastic and HNSCC samples. Two novel single nucleotide polymorphism (SNPs) were found in the promoter region of SH3GL2. Reduced expression of these genes showed concordance with their alterations. Overexpression of EGFR and p-EGFR were significantly associated with reduced expression and alterations of SH3GL2 and CDC25A respectively. In-vitro demethylation experiment by 5-aza-2'-deoxycytidine (5-aza-dC) showed upregulation of SH3GL2 and CDC25A and downregulation of EGFR expression in Hep2 cell line. Poor patient outcome was predicted in the cases with alterations of SH3GL2 and CDC25A in presence of human papilloma virus (HPV) infection. Also, low SH3GL2 and high EGFR expression was a predictor of poor patient survival. Thus, our data suggests that overexpression of EGFR due to its reduced degradation and dephosphorylation is needed for development of HNSCC.

Harmonic oscillator coherent states are well known to be the analogue of classical states. On the other hand, nonlinear and generalised coherent states may possess nonclassical properties. In this article, we study the nonclassical behaviour of nonlinear coherent states for generalised classes of models corresponding to the generalised ladder operators. A comparative analysis among them indicates that the models with quadratic spectrum are more nonclassical than the others. Our central result is further underpinned by the comparison of the degree of nonclassicality of squeezed states of the corresponding models.

We investigate certain properties of -valued two-dimensional (2D) soliton surfaces associated with the integrable sigma models constructed by orthogonal rank-one Hermitian projectors, which are defined on the 2D Riemann sphere with a finite action functional. Several new properties of the projectors mapping onto one-dimensional subspaces, as well as their relations with three mutually different immersion formulas, namely, the generalized Weierstrass, Sym–Tafel and Fokas–Gelfand, have been discussed in detail. Explicit connections among these three surfaces are also established by purely analytical descriptions, and it is demonstrated that the three immersion formulas actually correspond to the single surface parametrized by some specific conditions. [ABSTRACT FROM AUTHOR]

We generalize the Milne quantization condition to non-Hermitian systems. In the general case the underlying nonlinear Ermakov–Milne–Pinney equation needs to be replaced by a nonlinear integral differential equation. However, when the system is PT-symmetric or/and quasi/pseudo-Hermitian the equations simplify and one may employ the original energy integral to determine its quantization. We illustrate the working of the general framework with the Swanson model and two explicit examples for pairs of supersymmetric Hamiltonians. In one case both partner Hamiltonians are Hermitian and in the other a Hermitian Hamiltonian is paired by a Darboux transformation to a non-Hermitian one. [ABSTRACT FROM AUTHOR]