250 research outputs found

    Quantumness and memory of one qubit in a dissipative cavity under classical control

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    Hybrid quantum–classical systems constitute a promising architecture for useful control strategies of quantum systems by means of a classical device. Here we provide a comprehensive study of the dynamics of various manifestations of quantumness with memory effects, identified by non-Markovianity, for a qubit controlled by a classical field and embedded in a leaky cavity. We consider both Leggett–Garg inequality and quantum witness as experimentally-friendly indicators of quantumness, also studying the geometric phase of the evolved (noisy) quantum state. We show that, under resonant qubit-classical field interaction, a stronger coupling to the classical control leads to enhancement of quantumness despite a disappearance of non-Markovianity. Differently, increasing the qubit-field detuning (out-of-resonance) reduces the nonclassical behavior of the qubit while recovering non-Markovian features. We then find that the qubit geometric phase can be remarkably preserved irrespective of the cavity spectral width via strong coupling to the classical field. The controllable interaction with the classical field inhibits the effective time-dependent decay rate of the open qubit. These results supply practical insights towards a classical harnessing of quantum properties in a quantum information scenari

    Structure, Wettability, Corrosion and Biocompatibility of Nitinol Treated by Alkaline Hydrothermal and Hydrophobic Functionalization for Cardiovascular Applications

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    The main objective of this study is to hydrophobize nitinol (Ni-Ti alloy) for cardiovascular applications. For this purpose, medical nitinol samples were subjected to sodium hydroxide hydrothermal treatments at various temperatures, followed by hexadecyltrimethoxysilane (HDTMS) functionalization. Then, the structure, wettability, corrosion, cytocompatibility and cell adhesion of the prepared samples were evaluated. According to the results, porous blade-shaped layers of sodium titanate were formed on the substrate surface as a result of the alkaline treatment. These nano-rough features offered considerable hydrophobicity after HDTMS processing, where a maximum water contact angle of about 140° was obtained for the sample treated at 120 °C, followed by the HDTMS coating. In contrast to the individual application of the alkaline treatments, the subsequent HDTMS processing improved corrosion resistance in the simulated body fluid. Although all the samples presented appropriate cytocompatibility with respect to human umbilical vein endothelial cells, the cells did not show an adhesion tendency to the hydrophobic surfaces. It is concluded that alkaline hydrothermal and HDTMS processed nitinol can be considered for cardiovascular applications demanding hydrophobic surfaces

    Gamma irradiation of ocular melanoma and lymphoma cells in the presence of gold nanoparticles: in vitro study

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    The aim of this work was to determine whether conjugation of cultivated choroidal melanoma and Burkitt's lymphoma cells with gold nanoparticles (GNPs) is beneficial for these series of ocular cancer patients. GNPs are radiosensitizers and can sensitize tumors to radiotherapy.This application has been examined in several tumor types, but not in choroidal melanoma. This study shows the results of in vitro study on the choroidal melanoma and also Burkitt's lymphoma cells in the presence of GNPs during continuous gamma irradiation. Cytotoxicity of GNPs were assessed for five different concentrations then cultured melanoma and Burkitt's lymphoma cells were irradiated with a Gamma source in the presence and absence of NPs. Incubation of melanoma cells with GNP concentrations below 100 μg/ml, accompanied by gamma irradiation, increased cell death (P value = 0.016). In the absence of irradiation, GNPs at these concentrations did not affect cultured melanoma cell metabolism. Reduced cell viability resulted from a significant increase in absorbed energy by the tumor. Moreover, GNP concentrations higher than 200 μg/ml induced cytotoxicity in melanoma cells. Cytotoxicity assay in GNPs-loaded Burkitt's lymphoma cells showed a slight decrease in cell viability at 50 μg/ml and clear cytotoxicity at concentrations higher than 100 μg/ml (P value = 0.035). Concentration and proper injection doses of GNPs in sensitive tissues such as the human eye are important variables yet to be determined.This is the first report of choroidal melanoma dosimetry performed in the presence of GNPs and provides valuable insights into future therapeutic approaches. Further in vitro study with more different sizes and concentrations is needed to determine the optimum size and concentration before any clinical research in this regard. © 2018 The Authors. Journal of Applied Clinical Medical Physics published by Wiley Periodicals, Inc. on behalf of American Association of Physicists in Medicine

    Gamma irradiation of ocular melanoma and lymphoma cells in the presence of gold nanoparticles: in vitro study

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    The aim of this work was to determine whether conjugation of cultivated choroidal melanoma and Burkitt's lymphoma cells with gold nanoparticles (GNPs) is beneficial for these series of ocular cancer patients. GNPs are radiosensitizers and can sensitize tumors to radiotherapy.This application has been examined in several tumor types, but not in choroidal melanoma. This study shows the results of in vitro study on the choroidal melanoma and also Burkitt's lymphoma cells in the presence of GNPs during continuous gamma irradiation. Cytotoxicity of GNPs were assessed for five different concentrations then cultured melanoma and Burkitt's lymphoma cells were irradiated with a Gamma source in the presence and absence of NPs. Incubation of melanoma cells with GNP concentrations below 100 μg/ml, accompanied by gamma irradiation, increased cell death (P value = 0.016). In the absence of irradiation, GNPs at these concentrations did not affect cultured melanoma cell metabolism. Reduced cell viability resulted from a significant increase in absorbed energy by the tumor. Moreover, GNP concentrations higher than 200 μg/ml induced cytotoxicity in melanoma cells. Cytotoxicity assay in GNPs-loaded Burkitt's lymphoma cells showed a slight decrease in cell viability at 50 μg/ml and clear cytotoxicity at concentrations higher than 100 μg/ml (P value = 0.035). Concentration and proper injection doses of GNPs in sensitive tissues such as the human eye are important variables yet to be determined.This is the first report of choroidal melanoma dosimetry performed in the presence of GNPs and provides valuable insights into future therapeutic approaches. Further in vitro study with more different sizes and concentrations is needed to determine the optimum size and concentration before any clinical research in this regard. © 2018 The Authors. Journal of Applied Clinical Medical Physics published by Wiley Periodicals, Inc. on behalf of American Association of Physicists in Medicine

    Expansion of Single Cell Transcriptomics Data of SARS-CoV Infection in Human Bronchial Epithelial Cells to COVID-19

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    Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of coronavirus disease 19 (COVID-19) that was emerged as a new member of coronaviruses since December 2019 in Wuhan, China and then after was spread in all continentals. Since SARS-CoV-2 has shown about 77.5 similarity to SARS-CoV, the transcriptome and immunological regulations of SARS-CoV-2 was expected to have high percentage of overlap with SARS-CoV. Results: In this study, we applied the single cell transcriptomics data of human bronchial epithelial cells (2B4 cell line) infected with SARS-CoV, which was annotated in the Expression Atlas database to expand this data to COVID-19. In addition, we employed system biology methods including gene ontology (GO) and Reactome pathway analyses to define functional genes and pathways in the infected cells with SARS-CoV. The transcriptomics analysis on the Expression Atlas database revealed that most genes from infected 2B4 cell line with SARS-CoV were downregulated leading to immune system hyperactivation, induction of signaling pathways, and consequently a cytokine storm. In addition, GO:0016192 (vesicle-mediated transport), GO:0006886 (intracellular protein transport), and GO:0006888 (ER to Golgi vesicle-mediated transport) were shown as top three GOs in the ontology network of infected cells with SARS-CoV. Meanwhile, R-HAS-6807070 (phosphatase and tensin homolog or PTEN regulation) showed the highest association with other Reactome pathways in the network of infected cells with SARS-CoV. PTEN plays a critical role in the activation of dendritic cells, B- and T-cells, and secretion of proinflammatory cytokines, which cooperates with downregulated genes in the promotion of cytokine storm in the COVID-19 patients. Conclusions: Based on the high similarity percentage of the transcriptome of SARS-CoV with SARS-CoV-2, the data of immunological regulations, signaling pathways, and proinflammatory cytokines in SARS-CoV infection can be expanded to COVID-19 to have a valid platform for future pharmaceutical and vaccine studies. © 2020 The Author(s)

    Identification and characterization of a silent mutation in RNA binding domain of N protein coding gene from SARS-CoV-2

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    Objective: This study describes the occurrence of a silent mutation in the RNA binding domain of nucleocapsid phosphoprotein (N protein) coding gene from SARS-CoV-2 that may consequence to a missense mutation by onset of another single nucleotide mutation. Results: In the DNA sequence isolated from severe acute respiratory syndrome (SARS-CoV-2) in Iran, a coding sequence for the RNA binding domain of N protein was detected. The comparison of Chinese and Iranian DNA sequences displayed that a thymine (T) was mutated to cytosine (C), so �TTG� from China was changed to �CTG� in Iran. Both DNA sequences from Iran and China have been encoded for leucine. In addition, the second T in �CTG� in the DNA or uracil (U) in �CUG� in the RNA sequences from Iran can be mutated to another C by a missense mutation resulting from thymine DNA glycosylase (TDG) of human and base excision repair mechanism to produce �CCG� encoding for proline, which consequently may increase the affinity of the RNA binding domain of N protein to viral RNA and improve the transcription rate, pathogenicity, evasion from human immunity system, spreading in the human body, and risk of human-to-human transmission rate of SARS-CoV-2. © 2021, The Author(s)

    Identification and characterization of the first fish parvalbumin-like protein data from a pathogenic fungal species, Trichophyton violaceum

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    Parvalbumins are the most important fish allergens, which are heat-stable, classified in the family of calcium-binding EF-hand proteins, and contain one magnesium binding site. The functional connection between calcium and parvalbumin gives fish the high-speed swimming ability because of high concentration of Ca2+-binding parvalbumin in fish white muscles. Although parvalbumins are widely studied and conceivably play crucial roles in the physiology and swimming pattern of fishes, still no report is available about their presence in microbes, such as pathogenic fungal species. We detected a DNA sequence in the genome of Trichophyton violaceum and used in silico and polymerase chain reaction (PCR) technique with a designed pair of primers to identify it as parvalbumin-coding gene. © 2020 The Author

    Potential therapeutic agents to COVID-19: An update review on antiviral therapy, immunotherapy, and cell therapy

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    Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged in Wuhan, China, in December 2020 and coronavirus disease 19 (COVID-19) was later announced as pandemic by the World Health Organization (WHO). Since then, several studies have been conducted on the prevention and treatment of COVID-19 by potential vaccines and drugs. Although, the governments and global population have been attracted by some vaccine production projects, the presence of SARS-CoV-2-specific antiviral drugs would be an urge necessity in parallel with the efficient preventive vaccines. Various nonspecific drugs produced previously against other bacterial, viral, and parasite infections were recently evaluated for treating patients with COVID-19. In addition to therapeutic properties of these anti-COVID-19 compounds, some adverse effects were observed in different human organs as well. Not only several attentions were paid to antiviral therapy and treatment of COVID-19, but also nanomedicine, immunotherapy, and cell therapy were conducted against this viral infection. In this review study, we planned to introduce the present and potential future treatment strategies against COVID-19 and define the advantages and disadvantages of each treatment strategy. © 2021 The Author

    Comparison of the effect of argon, hydrogen, and nitrogen gases on the reduced graphene oxide-hydroxyapatite nanocomposites characteristics

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    In this study, the effect of the argon, nitrogen, and hydrogen gases on the final properties of the reduced graphene oxide-hydroxyapatite nanocomposites synthesized by gas injected hydrothermal method was investigated. Four samples were synthesized, which in the first sample the pressure was controlled by volume change at a constant concentration. In subsequent samples, the pressure inside the autoclave was adjusted by the injecting gases. The initial pressure of the injected gases was 10 bar and the final pressure considered was 25 bar. The synthesized powders were consolidated at 950 °C and 2 MPa by spark plasma sintering method. The final samples were subjected to Vickers indentation analysis. The findings of this study indicate that the injection of argon, hydrogen, and nitrogen gases improved the mechanical properties of the nanocomposites. Injection of gases increased the crystallinity and particle size of hydroxyapatite, and this increase was greater for nitrogen gas than for others. Injection of these gases increased the rate of graphene oxide reduction and in this case the effect of nitrogen gas was greater than the others. Figure not available: See fulltext. © 2020 The Author(s)
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