75 research outputs found

    Retroviral Vectors: Post Entry Events and Genomic Alterations

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    The curative potential of retroviral vectors for somatic gene therapy has been demonstrated impressively in several clinical trials leading to sustained long-term correction of the underlying genetic defect. Preclinical studies and clinical monitoring of gene modified hematopoietic stem and progenitor cells in patients have shown that biologically relevant vector induced side effects, ranging from in vitro immortalization to clonal dominance and oncogenesis in vivo, accompany therapeutic efficiency of integrating retroviral gene transfer systems. Most importantly, it has been demonstrated that the genotoxic potential is not identical among all retroviral vector systems designed for clinical application. Large scale viral integration site determination has uncovered significant differences in the target site selection of retrovirus subfamilies influencing the propensity for inducing genetic alterations in the host genome. In this review we will summarize recent insights gained on the mechanisms of insertional mutagenesis based on intrinsic target site selection of different retrovirus families. We will also discuss examples of side effects occurring in ongoing human gene therapy trials and future prospectives in the field

    An Analysis of the Barriers to Rational Education on Hegel's Perspective

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    The main purpose of this study is to analyze the barriers to intellectual education on Hegel's point of view. The present research was qualitative research and the research method used was qualitative content analysis. The results of this study showed that the individual barriers to rational education from Hegel's point of view are: self-centered, fear, abstraction, negative skepticism, austerity and social barriers to rational education are: utilitarianism, collectivism, hypocrisy and fear of judgment. Negative. According to Hegel, obstacles to intellectual education begin when a person, due to lack of personal independence, lack of free will and lack of reciprocal and equal relationship with another, can not act as an independent intellectual being or when actuality It should not act as an independent rational being, but as an object serving the interests and purposes of other people. However, Hegel considers the obstacles of rational training as other stages of raising awareness as a step towards the development and promotion of the individual's personality, because consciousness faces these limitations and the intellectual obstacles and suffering that it suffers in the meantime. Can be aware of his inadequacies, which leads him to put himself in front of himself as an object and by exploring himself, to re-measure his understanding of himself, to know what he is. And it overcomes its one-sidedness

    Hope and Despair in Amal Donqol and Siavash Kasraei’s Poems (A Semiotic Analysis of Time-Place and Myths Components)

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    IntroductionSemiotics has provided researchers in the immediate past years with a tool for analyzing, understanding, and criticism of literary texts and discovery of hidden meanings. Semiotics has tried to unveil, decipher, and discover the deep meanings behind the structure. Amal Donqol (a contemporary Egyptian poet) and Siavash Kasraei (an Iranian poet) lived in their turbulent times. Political and social disorders intensively influenced the content and structure of their poems. The comparative semiotic study investigates meticulously and in detail the works of the Egyptian and Iranian poets considering hope and despair. It hopes to have a better and deeper understanding of the poets’ thoughts and spirits and their influence on their poems. Moreover, the study makes the ground for better presenting of the similarities and differences of their attitudes, as they live in rather similar conditions.Using the semiotics of the application of time, place, and myths, the study investigated the duality of despair and hope  in some poems of the two poets regarding the structure and poetic language. It tried to answer the question that how despair and hope have been presented in the poems and in mentioned components and how their poetic and artistic manifestations are.  Method This descriptive-analytic study was done within the American framework of comparative literature.  DiscussionSemiology (or semiotics) is a new type of criticism that has had a great impact on literary studies and related research. This field of study interprets literary texts according to such criteria and layers as time, place, intertextuality, narration, character, etc. This study explored the place, time, and mythical characters to show the appearance of hope and despair in the selected poems. The components work as codes for the poet through which he shows his inner feelings and imposes positive or negative meaning upon them. The analysis of the signs unveils the hidden layers of meanings in a literary text and familiars readers with the world, thoughts, and feelings of its writer.Time and place as signs and their signified are various and wide in literary texts and important for reading texts. The poets have used many words showing place and time. In many cases, adverbs showing the place in Donqol and Kasraei's poems lose the characteristic of being adverb of place and become a signifier having specific signifiers. The time adverbs have also been used in this way as their poems shows the change many times. The words become positively or negatively marked as they convey the poets’ feelings.  These words convey meanings different from their place and time meanings, which engages the readership with one of the dualities of despair or hope. Myth is also an important component that imposes meaning on the meaning in works of both poets. Using and recreating the myths, the poets communicate their ideals and spirits to the audience.   Conclusion- The study investigated the duality of despair or hope in the poems of two poets based on the application of some components of the semiotics of time, place, and myths. The socio-political conditions that the two poets live in seem to be the same and their poems protest against their contemporary situation, but based on the mentioned examples one can say that when the poems have been composed, when death and despair were dominant in the mental space of poets, he optimistically expected a bright future, whereas death and despair are always dominant in Amal Danqol's poems.- As a result of the different views of the poets, time, place, and myth have a hopeful and liberating application in the poems. In Amal's poems, however, the place, time, and myth components become nightmares of fear and failure, as a result of his sad and desperate creations.- Finally, looking from semiotic analysis, it can be concluded that the fully optimistic and hopeful poems of Siavash Kasraei sometimes lack poetic fantasy and becomes similar to prose, making it a weakness of the poems. On the contrary, Amal Danqol's poems, though exaggerates in expressing darkness, they are totally strong and surprising sometimes regarding poetic beauties, creating new meanings, and linguistic deviations. 

    Investigating the effect of [C8Py][Cl] and [C18Py][Cl] ionic liquids on the water/oil interfacial tension by considering Taguchi method

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    Capillary and interfacial forces are of great influences of trapping hydrocarbon in porous media after primary and secondary recovery processes. The trapped crude oil in the reservoir can be mobilized and produced by reducing these forces. Thus, surfactant flooding, as a main enhanced oil recovery (EOR) method, is usually applied to reduce the interfacial tension (IFT) of crude oil–water system in porous medium and improves the oil recovery. This study focused on the effect of [C8Py][Cl] and [C18Py][Cl] ionic liquids (ILs), as a new family of surfactant, in combination with various salts including sodium chloride, potassium chloride, magnesium sulfate and potassium sulfate on IFT reduction. EOR injection solutions were prepared from mixing the ILs at different concentrations of 100, 250, 500 and 1000 ppm with the salts ranging from 500 to 80,000 ppm. Obtained results showed that the minimum IFT value from both ILs was achieved when the concentration of the ILs was about 1000 g/mL, and the concentrations of KCl, K2SO4, MgSO4 and NaCl were 1000, 2000, 500 and 80,000 ppm, respectively. The minimum IFTs were achieved when NaCl and ILs concentrations were the maximum and MgSO4 concentration was the minimum

    Integrase-deficient lentiviral vectors mediate efficient gene transfer to human vascular smooth muscle cells with minimal genotoxic risk

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    We have previously shown that injury-induced neointima formation was rescued by adenoviral-Nogo-B gene delivery. Integrase-competent lentiviral vectors (ICLV) are efficient at gene delivery to vascular cells but present a risk of insertional mutagenesis. Conversely, integrase-deficient lentiviral vectors (IDLV) offer additional benefits through reduced mutagenesis risk, but this has not been evaluated in the context of vascular gene transfer. Here, we have investigated the performance and genetic safety of both counterparts in primary human vascular smooth muscle cells (VSMC) and compared gene transfer efficiency and assessed the genotoxic potential of ICLVs and IDLVs based on their integration frequency and insertional profile in the human genome. Expression of enhanced green fluorescent protein (eGFP) mediated by IDLVs (IDLV-eGFP) demonstrated efficient transgene expression in VSMCs. IDLV gene transfer of Nogo-B mediated efficient overexpression of Nogo-B in VSMCs, leading to phenotypic effects on VSMC migration and proliferation, similar to its ICLV version and unlike its eGFP control and uninfected VSMCs. Large-scale integration site analyses in VSMCs indicated that IDLV-mediated gene transfer gave rise to a very low frequency of genomic integration compared to ICLVs, revealing a close-to-random genomic distribution in VSMCs. This study demonstrates for the first time the potential of IDLVs for safe and efficient vascular gene transfer

    AZT resistance of simian foamy virus reverse transcriptase is based on the excision of AZTMP in the presence of ATP

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    Azidothymidine (AZT, zidovudine) is one of the few nucleoside inhibitors known to inhibit foamy virus replication. We have shown previously that up to four mutations in the reverse transcriptase gene of simian foamy virus from macaque (SFVmac) are necessary to confer high resistance against AZT. To characterize the mechanism of AZT resistance we expressed two recombinant reverse transcriptases of highly AZT-resistant SFVmac in Escherichia coli harboring three (K211I, S345T, E350K) or four mutations (K211I, I224T, S345T, E350K) in the reverse transcriptase gene. Our analyses show that the polymerization activity of these mutants is impaired. In contrast to the AZT-resistant reverse transcriptase of HIV-1, the AZT resistant enzymes of SFVmac reveal differences in their kinetic properties. The SFVmac enzymes exhibit lower specific activities on poly(rA)/oligo(dT) and higher KM-values for polymerization but no change in KD-values for DNA/DNA or RNA/DNA substrates. The AZT resistance of the mutant enzymes is based on the excision of the incorporated inhibitor in the presence of ATP. The additional amino acid change of the quadruple mutant appears to be important for regaining polymerization efficiency

    Experimental investigation of the effect of Vitagnus plant extract on enhanced oil recovery process using interfacial tension (IFT) reduction and wettability alteration mechanisms

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    © 2020, The Author(s). Surfactant flooding is a chemical enhanced oil recovery (cEOR) process wherein anionic, cationic, non-ionic, and amphoteric surfactants are injected into oil reservoirs to produce more hydrocarbon. These chemical and industrial agents might cause some economic and environmental challenges. Recently, injection of natural surfactants, as new environmentally friendly EOR agents, for improving oil recovery has been proposed by researchers. In this study, the extract of Vitagnus, a natural surfactant, was used to minimize the interfacial tension (IFT) and alter the rock wettability towards the strong water-wet system, thereby improving the oil recovery from the carbonate rock The conductivity, pH, and turbidity measurements were undertaken to identify the critical micelle concentration (CMC) of the surfactant solutions prepared by mixing 500, 1000, 2000, 3000, 4000, 5000, 6000, and 7000 ppm of the Vitagnus extract and distilled water. The obtained experimental results reveal that the optimum CMC value of the used surfactant was 3000 ppm. At this CMC value, the IFT reduced from 29.5 to 5.28 mN/m, and the contact angle of the oil droplet on the surface of the carbonate rock decreased from 114° to 29°. Accordingly, during the tertiary process, oil recovery was improved from 44% to 54.6% OOIP (original oil in place) by injecting 2.25 PVs of the VIT3000 surfactant containing 3000 ppm of the plant extract

    Detection of occludable angle with anterior segment optical coherence tomography and Pentacam as non-contact screening methods

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    Purpose To evaluate diagnostic capacity for occludable anterior chamber angle detection with anterior segment optical coherence tomography (AS-OCT) and Pentacam. Methods Observational cross-sectional study with AS-OCT and Pentacam. AS-OCT measures: angle opening distance from Schwalbe line (SL) perpendicular (AOD-SL-Perp) and vertical to iris (AOD-SL-Vert), and iridotrabecular angle (ITA). Pentacam measures: anterior chamber depth (ACD), anterior chamber volume (ACV), and anterior chamber angle (ACA). We analysed Spearman's correlation with gonioscopic classification. Area under receiver operating characteristic curves (AUCs) for occludable angle detection were compared. Agreement between iridocorneal values of methods was evaluated. Results Seventy-four left eyes of 74 patients. Correlation between temporal AS-OCT and gonioscopy: 0.83 (p < 0.0001) AOD-SL-Perp temporal, 0.82 (p < 0.0001) AOD-SL-Vert temporal, and 0.69 (p < 0.0001) ITA temporal. Correlation between AS-OCT nasal and gonioscopy: 0.74 (p < 0.0001) AOD-SL-Perp nasal, 0.74 (p < 0.0001) AOD-SL-Vert nasal, and 0.70 (p < 0.0001) ITA nasal. Correlation of Pentacam with temporal gonioscopy: 0.57 (p < 0.0001) ACD, 0.56 (p < 0.0001) ACV, and 0.63 (p < 0.0001) ACA. Correlation of Pentacam with nasal gonioscopy: 0.47 (IC 0.27-0.73, p < 0.0001) ACD, 0.49 (p < 0.0001) ACV, and 0.56 (CI 0.38-0.7, p < 0.0001) ACA. AS-OCT AUCs: AOD-SL-Perp temporal 0.89 (CI 0.80-0.95), AOD-SL-Vert 0.87 (CI 0.77-0.94), ITA temporal 0.88 (CI 0.78-0.94), AOD-SL-Perp nasal 0.83 (CI 0.72-0.91), AOD-SL-Vert nasal 0.87 (CI 0.77-0.94), and ITA nasal 0.91 (IC 0.81-0.96). Pentacam AUCs: ACD 0.76 (CI 0.64-0.85), ACV 0.75 (CI 0.63-0.84), and ACA 0.84 (CI 0.74-0.92). No statistical differences between different AUCs. Intraclass correlation coefficient (ICC) of ACA (Pentacam) with ITA temporal (AS-OCT) 0.59 and with nasal ITA nasal (AS-OCT) 0.65. Conclusion Both systems show high capacity for non-contact occludable angle detection. But agreement between methods is moderate or low

    AZT-resistant foamy virus

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    AbstractAzidothymidine (AZT) is a reverse transcriptase (RT) inhibitor that efficiently blocks the replication of spumaretroviruses or foamy viruses (FVs). To more precisely elucidate the mechanism of action of the FV RT enzyme, we generated an AZT-resistant FV in cell culture. Biologically resistant virus was obtained for simian foamy virus from macaque (SFVmac), which was insensitive to AZT concentrations of 1 mM, but not for FVs derived from chimpanzees. Nucleotide sequencing revealed four non-silent mutations in the pol gene. Introduction of these mutations into an infectious molecular clone identified all changes to be required for the fully AZT-resistant phenotype of SFVmac. The alteration of individual sites showed that AZT resistance in SFVmac was likely acquired by consecutive acquisition of pol mutations in a defined order, because some alterations on their own did not result in an efficiently replicating virus, neither in the presence nor in the absence of AZT. The introduction of the mutations into the RT of the closely related prototypic FV (PFV) did not yield an AZT-resistant virus, instead they significantly impaired the viral fitness

    Hybrid off-river augmentation system as an alternative raw water resource: the hydrogeochemistry of abandoned mining ponds

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    The use of water from abandoned mining ponds under a hybrid off-river augmentation system (HORAS) has been initiated as an alternative water resource for raw water. However, it raises the questions over the safety of the use of such waters. In this study, the hydrogeochemical analysis of the waters is presented to assess the degree to which the water has been contaminated. Comparisons were made between sampling sites, i.e. abandoned mining ponds, active sand mining ponds and the receiving streams within Bestari Jaya, Selangor River basin. The aqueous geochemistry analysis showed different hydrochemical signatures of major elements between sites, indicating different sources of minerals in the water. Discharges from the sand mining ponds were found to contain elevated availability of dissolved concentrations of iron, manganese, lead, copper and zinc, among others. However, the quality of the water (from the main river) that is supplied for potable water consumption is at a satisfactory level despite being partly sourced from the abandoned mining ponds. In fact, all the metal concentrations detected were well below the Malaysia Ministry of Health guideline limits for untreated raw water. In addition, the results of the geochemical index analysis (i.e. geoaccumulation index, enrichment factor and modified contamination factor) showed that the rivers and abandoned mining ponds were generally unpolluted with respect to the metals found in sediments
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