812 results on '"Khachatryan L"'
Search Results
2. Microelectrophysiological Studies of the Ratio of Excitatory to Inhibitory Synaptic Processes in the Corticonigral Projection in a Model of Parkinson’s
- Author
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Poghosyan, M. V., Khachatryan, L. M., Danielyan, M. A., Avetisyan, Z. A., and Sarkissian, J. S.
- Published
- 2020
- Full Text
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3. The antimicrobial effects of silver nanoparticles obtained through the royal jelly on the yeasts Candida guilliermondii NP-4.
- Author
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Marutyan S, Karapetyan H, Khachatryan L, Muradyan A, Marutyan S, Poladyan A, and Trchounian K
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- Antifungal Agents pharmacology, Antifungal Agents chemistry, Microbial Sensitivity Tests, Superoxide Dismutase metabolism, Antioxidants pharmacology, Antioxidants chemistry, Oxidative Stress drug effects, Catalase metabolism, Lipid Peroxidation drug effects, Silver chemistry, Silver pharmacology, Metal Nanoparticles chemistry, Candida drug effects, Candida growth & development, Fatty Acids metabolism, Fatty Acids chemistry
- Abstract
The effect of silver nanoparticles (Ag NPs) obtained in the presence of royal jelly (RJ) on the growth of yeast Candida guilliermondii NP-4, on the total and H
+ -ATPase activity, as well as lipid peroxidation process and antioxidant enzymes (superoxide dismutase (SOD), catalase) activity was studied. It has been shown that RJ-mediated Ag NPs have a fungicide and fungistatic effects at the concentrations of 5.4 µg mL-1 and 27 µg mL-1 , respectively. Under the influence of RJ-mediated Ag NPs, a decrease in total and H+ -ATPase activity in yeast homogenates by ~ 90% and ~ 80% was observed, respectively. In yeast mitochondria total and H+ -ATPase activity depression was detected by ~ 80% and ~ 90%, respectively. The amount of malondialdehyde in the Ag NPs exposed yeast homogenate increased ~ 60%, the catalase activity increased ~ 70%, and the SOD activity-~ 30%. The obtained data indicate that the use of RJ-mediated Ag NPs have a diverse range of influence on yeast cells. This approach may be important in the field of biomedical research aimed at evaluating the development of oxidative stress in cells. It may also contribute to a more comprehensive understanding of antimicrobial properties of RJ-mediated Ag NPs and help control the proliferation of pathogenic fungi., (© 2024. The Author(s).)- Published
- 2024
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4. SYSTEMIC OR LIMITED IS HEMISCLERODERMA OF FACE IN A PERSON WITH UVEITIS? EXPERIENCE OF 10 CASES OF UVEITIS IN HEMISCLERODERMA OF FACE FROM ONE RHEUMATOLOGY CENTER.
- Author
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Osminina M, Aslamazova A, Podchernyaeva N, Khachatryan L, Velikoretskaya M, Chebysheva S, and Polyanskaya A
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- Humans, Child, Female, Male, Retrospective Studies, Adolescent, Child, Preschool, Scleroderma, Localized complications, Scleroderma, Localized pathology, Magnetic Resonance Imaging, Iridocyclitis diagnosis, Uveitis complications, Uveitis diagnosis, Uveitis pathology
- Abstract
Linear scleroderma of head and face (LSH) in children is a severe disorder, that results in hemiatrophy of skin, subcutaneuse tissue, bones with functional disabilities, neurologic disorders and uveal involvement. The aim of the research was to establish uveal involvement in children with hemifacial scleroderma. Materials and methods: A retrospective analysis was done in a group of 110 children with hemifacial scleroderma. A comprehensive clinical, laboratory and instrumental examination was performed, including MRI of the brain, EEG, and an ophthalmologist's examination, which included visometry, biomicroscopy, and ophthalmoscopy. Results: 10 cases of uveal involvement were detected (9% of 110 pt). 9 patients had anterior segment inflammation (iridocyclitis), in 2 iridocyclitis was combined with retinal changes (in 1- peripheral focal chorioretinitis, in 1- iridocyclitis and central focal chorioretinitis). In one case, iridocyclitis was combined with optic neuropathy. In 3 children uveitis appeared at the disease debute, in the others 3-10 years later. Uveal inflammation in all cases was on the side of scleroderma skin involvement. In 3 children uveitis was bilateral. Seizures and concomittant foci in white matter of the brain were detected in 2 children with uveitis. 90% of the group had positive antinuclear factor. Persistent decrease in visual acuity developed in 3 patients. Соnclusion: Patients with LSH must undergo routine eye examination using basic ophthalmological techniques (visometry, biomicroscopy, ophthalmoscopy) every 6 months and highly necessary in case of relapse of scleroderma We assume that patients with UI in LSH must be defined as patients with JSS and treated intensively with systemicglucocorticoids, cytostatics and even biologics in case of resistance.
- Published
- 2024
5. Prosthetic rehabilitation of patients with maxillary oncology defects using zygomatic implants.
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Mathevosyan D, Hovhannisyan S, Mashinyan K, Khachatryan L, Badalyan A, and Hakobyan G
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- Humans, Male, Female, Middle Aged, Adult, Aged, Dental Implants, Maxilla surgery, Palatal Obturators, Treatment Outcome, Dental Prosthesis, Implant-Supported methods, Zygoma surgery, Maxillary Neoplasms surgery, Maxillary Neoplasms rehabilitation
- Abstract
Purpose: Prosthetics for patients after oncological resection of the upper jaw is a complex problem associated with the physiological and anatomical separation of the oral cavity and the nasal/paranasal region. This study reports the clinical results of the use of the zygomatic implants for prosthetic rehabilitation in patients with maxillectomy due to upper jaw tumors., Materials and Methods: The study included 16 patients who underwent prosthetic rehabilitation using a zygomatic implant after maxillectomy period from 2021 to 2023. After the tumor was removed, immediate surgical obturators were placed. Main prosthetic rehabilitation was performed 6-12 months after tumor removal, but before that, a temporary obturator was made and used. Six-twelve months after tumor resection, 1-4 zygomatic implants were inserted into the zygomatic bone unilaterally or bilaterally. A total of 42 zygomatic implants were installed, 2 of which were unsuccessful and were removed in 1 patient. The implants were placed using the surgical guide, which was planned and prepared digitally., Results: No postsurgical complications were seen, and the patients were discharged from the hospital after 7-10 days. The patients were able to return to a normal diet (hard food) after just 7 days following surgery, with no further complaints regarding function or pain, apart from the residual edema caused by the intervention., Conclusions: The use of prostheses fixed on zygomatic implants in patients with maxillary defects is an effective method of prosthodontic rehabilitation in complex clinical cases after maxillectomy., (© 2024. The Author(s).)
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- 2024
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6. Blinatumomab as postremission therapy replaces consolidation and substantial parts of maintenance chemotherapy and results in stable MRD negativity in children with newly diagnosed B-lineage ALL.
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Mikhailova E, Popov A, Roumiantseva J, Budanov O, Lagoyko S, Zharikova L, Miakova N, Litvinov D, Khachatryan L, Pshonkin A, Ponomareva N, Boichenko E, Varfolomeeva S, Dinikina J, Novichkova G, Henze G, and Karachunskiy A
- Subjects
- Adolescent, Child, Child, Preschool, Female, Humans, Infant, Male, Consolidation Chemotherapy methods, Maintenance Chemotherapy methods, Pilot Projects, Antibodies, Bispecific therapeutic use, Antibodies, Bispecific pharmacology, Neoplasm, Residual drug therapy, Precursor B-Cell Lymphoblastic Leukemia-Lymphoma drug therapy
- Abstract
The bispecific T cell-binding antibody blinatumomab (CD19/CD3) is widely and successfully used for the treatment of children with relapsed or refractory B-cell precursor acute lymphoblastic leukemia (BCP-ALL). Here, we report the efficacy of a single course of blinatumomab instead of consolidation chemotherapy to eliminate minimal residual disease (MRD) and maintain stable MRD-negativity in children with primary BCP-ALL.Between February 2020 and November 2022, 177 children with non-high-risk BCP-ALL were enrolled in the ALL-MB 2019 pilot study (NCT04723342). Patients received the usual risk-adapted induction therapy according to the ALL-MB 2015 protocol. Those who achieved a complete remission at the end of induction (EOI) received treatment with blinatumomab immediately after induction at a dose of 5 μg/m
2 /day for 7 days and 21 days at a dose of 15 μg/m2 /day, followed by 12 months of maintenance therapy. MRD was measured using multicolor flow cytometry (MFC) at the EOI, then immediately after blinatumomab treatment, and then four times during maintenance therapy at 3-month intervals.All 177 patients successfully completed induction therapy and achieved a complete hematological remission. In 174 of these, MFC-MRD was measured at the EOI. 143 patients (82.2%) were MFC-MRD negative and the remaining 31 patients had varying degrees of MFC-MRD positivity.MFC-MRD was assessed in all 176 patients who completed the blinatumomab course. With one exception, all patients achieved MFC-MRD negativity after blinatumomab, regardless of the MFC-MRD score at EOI. One adolescent girl with high MFC-MRD positivity at EOI remained MFC-MRD positive. Of 175 patients who had completed 6 months of maintenance therapy, MFC-MRD data were available for 156 children. Of these, 155 (99.4%) were MFC-MRD negative. Only one boy with t(12;21) (p13;q22)/ ETV6::RUNX1 became MFC-MRD positive again. The remaining 174 children had completed the entire therapy. MFC-MRD was examined in 154 of them, and 153 were MFC-MRD negative. A girl with hypodiploid BCP-ALL showed a reappearance of MFC-MRD with subsequent relapse.In summary, a single 28-day course of blinatumomab immediately after induction, followed by 12 months of maintenance therapy, is highly effective in achieving MRD-negativity in children with newly diagnosed non-high risk BCP-ALL and maintaining MRD-negative remission at least during the treatment period., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)- Published
- 2024
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7. Diagnostic and Prognostic Value of Indicators of Bone Metabolism Markers in Patients Following Mandibulectomy and Free Fibula Flap Reconstruction with Endosteal Implants.
- Author
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Hakobyan G, Khachatryan L, Khudaverdyan M, Gegham T, and Burnazyan S
- Abstract
Purpose: To evaluate and assess the indicators of bone metabolism markers osteocalcin and β -Cross-Laps in blood serum as a tool for monitoring bone regeneration and determining the time of implantation in patients after mandibulectomy and reconstruction of a free fibular flap with subsequent endosteal implants., Materials and Methods: Forty-eight patients in a 6-year period participated in this study, due to resection for tumors. All patients underwent reconstruction with fibula free flap after tumor resection, 4-6 months after osteoectomy, dental implants were installed with further orthopedic rehabilitation. To assess the rate of bone remodeling after transplantation, the content biochemical markers of bone remodeling osteocalcin and β -Cross-Laps serum were determined by enzyme immunoassay., Results: All 46 fibular free flaps were healed without complications and were survived. A total 326 implants installed, 8 implants failed to osseointegrate, and 6 implants failed after 5 years of loading (peri-implantitis). Success rate of implants after 5 years was 95,7%. In patients before surgery, the mean of osteocalcin levels was 8.5 ng/ml, two months later, there was a sharp increase in the content of osteocalcin by 15.4 ng/ml, after four months reached 24.7 ng/ml, after six months of 28.6 ng/ml, then the indicator began to decrease and after 12 months it was approaching the norm of 14.7 ng/ml. In patients before surgery, the mean level of β -Cross-Laps was 0.76 ng/ml, after two months bone transplantation the mean level of β -Cross-Laps decreased to - 0.65 ng/ml, after four months the indicator increased and reached of 0.98 ng/ml, after six months the indicator was - 1.56 ng/ml, then these indicators began to decrease and after 12 months, approaching normal values of - 0.87 ng/ml. There is a correlation between different concentrations of osteocalcin or β -Cross- Laps and the success rate of implants. Implants were shown to be unsuccessful low concentrations of osteocalcin and high concentrations of β -Cross-Laps in serum., Conclusion: Studies have shown that the long-term survival and success rates of implants placed in the reconstructed areas may guarantee an excellent prognosis of implant-supported prostheses. Bone markers in blood serum osteocalcin and β -Cross-Laps can be used to evaluate the rate of bone remodeling, which allows you to determine the time of implantation., Competing Interests: Conflict of interestThe author declares that he has no conflict of interest and there was no external source of funding for the present study. None of the authors have any relevant financial relationship(s) with a commercial interest., (© The Association of Oral and Maxillofacial Surgeons of India 2023. Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.)
- Published
- 2024
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8. On a Class of Infinite Systems of Linear Equations Originating in Statistical Physics
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Khachatryan, L. A. and Nahapetian, B. S.
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- 2019
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9. Investigating the association between diabetes and carpal tunnel syndrome: A systematic review and meta-analysis approach.
- Author
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Sanjari E, Raeisi Shahraki H, G Khachatryan L, and Mohammadian-Hafshejani A
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- Humans, Diabetes Mellitus epidemiology, Odds Ratio, Publication Bias, Risk Factors, Carpal Tunnel Syndrome epidemiology, Carpal Tunnel Syndrome complications
- Abstract
Introduction: In recent years, several studies have reported on the relationship between diabetes and carpal tunnel syndrome (CTS). However, due to their contradictory results, a systematic review and meta-analysis were conducted to investigate this subject., Methods: This study is a systematic review and meta-analysis of studies published in ISI Web of Science, Scopus, PubMed, Cochrane, Google Scholar, and Embase databases. Heterogeneity in the studies included in the meta-analysis was evaluated using statistical tests such as the Chi-square test, I2, and forest plots. Publication bias was assessed using Begg's and Egger's tests., Results: This investigation analyzed data from 42 studies conducted between 1985 and 2022, with a total of 3,377,816 participants. The meta-analysis demonstrated that the odds ratio (OR) of CTS in participants with a history of diabetes compared to those without was 1.90 (95% CI: 1.64-2.21; P-value < 0.001). Given that publication bias was observed in this study (Begg's test P-value = 0.01), the modified OR was calculated with consideration of missed studies, which was 1.68 (95% CI: 1.45-1.94; P-value < 0.001)., Conclusion: The results of this study suggest that diabetic patients have 90% higher odds of developing CTS compared to non-diabetic individuals, which is statistically significant., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Sanjari et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)
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- 2024
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10. Duality of Energy and Probability in Finite-Volume Models of Statistical Physics.
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Khachatryan, L. A.
- Subjects
STATISTICAL models ,RANDOM sets ,PROBABILITY theory ,FINITE fields ,MATHEMATICAL physics ,RANDOM fields ,STATISTICAL physics - Abstract
Copyright of National Academy of Sciences of Armenia Reports / Doklady Nacionalnaâ Akademiâ Nauk Armenii is the property of National Academy of Sciences of the Republic of Armenia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2023
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11. Rational Processing of Refractory Copper-Bearing Ores
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Ignatkina, V. A., Bocharov, V. A., Makavetskas, A. R., Kayumov, A. A., Aksenova, D. D., Khachatryan, L. S., and Fishchenko, Yu. Yu.
- Published
- 2018
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12. Forced Vibrations of a Two-Layer Orthotropic Shell with an Incomplete Contact Between Layers
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Ghulghazaryan, L. G. and Khachatryan, L. V.
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- 2018
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13. New Features of Laboratory-Generated EPFRs from 1,2-Dichlorobenzene (DCB) and 2-Monochlorophenol (MCP).
- Author
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Khachatryan L, Rezk MY, Nde D, Hasan F, Lomnicki S, Boldor D, Cook R, Sprunger P, Hall R, and Cormier S
- Abstract
The present research is primarily focused on investigating the characteristics of environmentally persistent free radicals (EPFRs) generated from commonly recognized aromatic precursors, namely, 1,2-dichlorobenzene (DCB) and 2-monochlorophenol (MCP), within controlled laboratory conditions at a temperature of 230 °C, termed as DCB230 and MCP230 EPFRs, respectively. An intriguing observation has emerged during the creation of EPFRs from MCP and DCB utilizing a catalyst 5% CuO/SiO
2 , which was prepared through various methods. A previously proposed mechanism, advanced by Dellinger and colleagues (a conventional model), postulated a positive correlation between the degree of hydroxylation on the catalyst's surface (higher hydroxylated, HH and less hydroxylated, LH) and the anticipated EPFR yields. In the present study, this correlation was specifically confirmed for the DCB precursor. Particularly, it was observed that increasing the degree of hydroxylation at the catalyst's surface resulted in a greater yield of EPFRs for DCB230. The unexpected finding was the indifferent behavior of MCP230 EPFRs to the surface morphology of the catalyst, i.e., no matter whether copper oxide nanoparticles are distributed densely, sparsely, or completely agglomerated. The yields of MCP230 EPFRs remained consistent regardless of the catalyst type or preparation protocol. Although current experimental results confirm the early model for the generation of DCB EPFRs (i.e., the higher the hydroxylation is, the higher the yield of EPFRs), it is of utmost importance to closely explore the heterogeneous alternative mechanism(s) responsible for generating MCP230 EPFRs, which may run parallel to the conventional model. In this study, detailed spectral analysis was conducted using the EPR technique to examine the nature of DCB230 EPFRs and the aging phenomenon of DCB230 EPFRs while they exist as surface-bound o -semiquinone radicals ( o -SQ) on copper sites. Various aspects concerning bound radicals were explored, including the hydrogen-bonding tendencies of o -semiquinone ( o -SQ) radicals, the potential reversibility of hydroxylation processes occurring on the catalyst's surface, and the analysis of selected EPR spectra using EasySpin MATLAB. Furthermore, alternative routes for EPFR generation were thoroughly discussed and compared with the conventional model., Competing Interests: The authors declare no competing financial interest., (© 2024 The Authors. Published by American Chemical Society.)- Published
- 2024
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14. Environmentally persistent free radicals: Methods for combustion generation, whole-body inhalation and assessing cardiopulmonary consequences.
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Aryal A, Noël A, Khachatryan L, Cormier SA, Chowdhury PH, Penn A, Dugas TR, and Harmon AC
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- Animals, Male, Mice, Mice, Inbred C57BL, Free Radicals, Particulate Matter toxicity, Reactive Oxygen Species metabolism, Cytochrome P-450 CYP1A1, Air Pollutants toxicity
- Abstract
Particulate matter (PM) containing environmentally persistent free radicals (EPFRs) results from the incomplete combustion of organic wastes which chemisorb to transition metals. This process generates a particle-pollutant complex that continuously redox cycles to produce reactive oxygen species. EPFRs are well characterized, but their cardiopulmonary effects remain unknown. This publication provides a detailed approach to evaluating these effects and demonstrates the impact that EPFRs have on the lungs and vasculature. Combustion-derived EPFRs were generated (EPFR lo: 2.1e
-16 radical/g, EPFR hi: 5.5e-17 radical/g), characterized, and verified as representative of those found in urban areas. Dry particle aerosolization and whole-body inhalation were established for rodent exposures. To verify that these particles and exposures recapitulate findings relevant to known PM-induced cardiopulmonary effects, male C57BL6 mice were exposed to filtered air, ∼280 μg/m3 EPFR lo or EPFR hi for 4 h/d for 5 consecutive days. Compared to filtered air, pulmonary resistance was increased in mice exposed to EPFR hi. Mice exposed to EPFR hi also exhibited increased plasma endothelin-1 (44.6 vs 30.6 pg/mL) and reduced nitric oxide (137 nM vs 236 nM), suggesting vascular dysfunction. Assessment of vascular response demonstrated an impairment in endothelium-dependent vasorelaxation, with maximum relaxation decreased from 80% to 62% in filtered air vs EPFR hi exposed mice. Gene expression analysis highlighted fold changes in aryl hydrocarbon receptor (AhR) and antioxidant response genes including increases in lung Cyp1a1 (8.7 fold), Cyp1b1 (9 fold), Aldh3a1 (1.7 fold) and Nqo1 (2.4 fold) and Gclc (1.3 fold), and in aortic Cyp1a1 (5.3 fold) in mice exposed to EPFR hi vs filtered air. We then determined that lung AT2 cells were the predominate locus for AhR activation. Together, these data suggest the lung and vasculature as particular targets for the health impacts of EPFRs and demonstrate the importance of additional studies investigating the cardiopulmonary effects of EPFRs., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)- Published
- 2023
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15. Description of random fields by systems of conditional distributions.
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Khachatryan, L. A.
- Subjects
RANDOM fields ,MARKOV random fields ,INVERSE problems ,DISTRIBUTION (Probability theory) - Abstract
In this paper, we consider the direct and inverse problems of the description of lattice positive random fields by various systems of finite-dimensional (as well as one-point) probability distributions parameterized by boundary conditions. In the majority of cases, we provide necessary and sufficient conditions for the system to be a conditional distribution of a (unique) random field. The exception is Dobrushin-type systems for which only sufficient conditions are known. Also, we discuss possible applications of the considered systems. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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16. Results and lessons learned from the sbv IMPROVER metagenomics diagnostics for inflammatory bowel disease challenge.
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Khachatryan L, Xiang Y, Ivanov A, Glaab E, Graham G, Granata I, Giordano M, Maddalena L, Piccirillo M, Manipur I, Baruzzo G, Cappellato M, Avot B, Stan A, Battey J, Lo Sasso G, Boue S, Ivanov NV, Peitsch MC, Hoeng J, Falquet L, Di Camillo B, Guarracino MR, Ulyantsev V, Sierro N, and Poussin C
- Subjects
- Humans, Metagenomics, Inflammatory Bowel Diseases diagnosis, Inflammatory Bowel Diseases genetics, Colitis, Ulcerative diagnosis, Crohn Disease diagnosis, Crohn Disease genetics, Gastrointestinal Microbiome genetics
- Abstract
A growing body of evidence links gut microbiota changes with inflammatory bowel disease (IBD), raising the potential benefit of exploiting metagenomics data for non-invasive IBD diagnostics. The sbv IMPROVER metagenomics diagnosis for inflammatory bowel disease challenge investigated computational metagenomics methods for discriminating IBD and nonIBD subjects. Participants in this challenge were given independent training and test metagenomics data from IBD and nonIBD subjects, which could be wither either raw read data (sub-challenge 1, SC1) or processed Taxonomy- and Function-based profiles (sub-challenge 2, SC2). A total of 81 anonymized submissions were received between September 2019 and March 2020. Most participants' predictions performed better than random predictions in classifying IBD versus nonIBD, Ulcerative Colitis (UC) versus nonIBD, and Crohn's Disease (CD) versus nonIBD. However, discrimination between UC and CD remains challenging, with the classification quality similar to the set of random predictions. We analyzed the class prediction accuracy, the metagenomics features by the teams, and computational methods used. These results will be openly shared with the scientific community to help advance IBD research and illustrate the application of a range of computational methodologies for effective metagenomic classification., (© 2023. The Author(s).)
- Published
- 2023
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17. Efficacy of combined immunosuppression with or without eltrombopag in children with newly diagnosed aplastic anemia.
- Author
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Goronkova O, Novichkova G, Salimova T, Kalinina I, Baidildina D, Petrova U, Antonova K, Sadovskaya M, Suntsova E, Evseev D, Matveev V, Venyov D, Khachatryan L, Litvinov D, Pshonkin A, Ovsyannikova G, Kotskaya N, Gobadze D, Olshanskaya Y, Popov A, Raykina E, Mironenko O, Voronin K, Purbueva B, Boichenko E, Dinikina Y, Guseynova E, Sherstnev D, Kalinina E, Mezentsev S, Streneva O, Yudina N, Plaksina O, Erega E, Maschan M, and Maschan A
- Subjects
- Humans, Treatment Outcome, Immunosuppression Therapy, Immunosuppressive Agents adverse effects, Anemia, Aplastic diagnosis, Anemia, Aplastic drug therapy
- Abstract
We compared the efficacy and safety of eltrombopag (ELTR) combined with immunosuppressive therapy (IST) and IST alone in treatment-naïve children with severe (SAA) and very severe (vSAA) aplastic anemia. Ninety-eight pediatric patients were randomized to receive horse antithymocyte globulin (hATG) and cyclosporin A (CsA) with (n = 49) or without (n = 49) ELTR. The primary endpoint was the overall response rate (ORR) at 4 months. After 4 months, nonresponders were crossed over to the alternative group. In all patients, the ORR in ELTR + IST and IST groups was similar (65% vs 53%; P = .218); however, the complete response (CR) rate was significantly higher in the ELTR + IST group (31% vs 12%; P = .027). In severity subgroups, the ORR was 89% vs 57% (P = .028) in favor of IST + ELTR in SAA, but it did not differ in patients with vSAA (52% vs 50%; P = .902). At 6 months after the crossover, 61% of initial ELTR(-) patients achieved a response compared with 17% of initial ELTR(+) patients (P = .016). No significant difference in ELTR + IST and IST groups was observed in the 3-year overall survival (OS) (89% vs 91%; P = .673) or the 3-year event-free survival (EFS) (53% vs 41%; P = .326). There was no unexpected toxicity related to ELTR. Adding ELTR to standard IST was well tolerated and increased the CR rate. The greatest benefit from ELTR combined with IST was observed in patients with SAA but not in those with vSAA. The second course of IST resulted in a high ORR in initial ELTR(-) patients who added ELTR and had limited efficacy among patients who received ELTR upfront. This trial was registered at Clinicaltrials.gov as #NCT03413306., (© 2023 by The American Society of Hematology. Licensed under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0), permitting only noncommercial, nonderivative use with attribution. All other rights reserved.)
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- 2023
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18. Randomization in the construction of multidimensional martingales
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Khachatryan, L. A. and Nahapetian, B. S.
- Published
- 2013
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19. Effects of Temperature and UV Light on Degradation of α-Tocopherol in Free and Dissolved Form
- Author
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Sabliov, Cristina M., Fronczek, C., Astete, C. E., Khachaturyan, M., Khachatryan, L., and Leonardi, C.
- Published
- 2009
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20. Basic foundations of selection and joint application of selective collectors and flotation depressants of sulfide minerals with close physicochemical properties
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Bocharov, V. A., Ignatkina, V. A., and Khachatryan, L. S.
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- 2008
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21. Modified reagent mode in porphyry copper-molybdenum ore flotation
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Bocharov, V. A., Khachatryan, L. S., Ignatkina, V. A., and Baatarkhuu, Zh.
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- 2008
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22. Metagenomics : beyond the horizon of current implementations and methods
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Khachatryan, L., Knijff, P. de, Laros, J.F.J., Geluk, A., Kroes, A.C.M., Kok, J.N., Sijen, T., and Leiden University
- Subjects
Bioinfromatics ,Metagenomics - Abstract
The current field of metagenomics can be summarised by three main questions: "Who is in metagenome?" (or "How complex the metagenome is?"), "What are they doing?" and "What is the difference between two metagenomes?".This research was dedicated to creating new and evaluating already existing methods answering these questions.
- Published
- 2020
23. Environmentally persistent free radicals enhance SARS-CoV-2 replication in respiratory epithelium.
- Author
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Yamamoto A, Sly PD, Chew KY, Khachatryan L, Begum N, Yeo AJ, Vu LD, Short KR, Cormier SA, and Fantino E
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- Humans, Antioxidants metabolism, Tumor Necrosis Factor-alpha metabolism, Angiotensin-Converting Enzyme 2 metabolism, Free Radicals metabolism, Cytokines metabolism, Respiratory Mucosa metabolism, Oxidants metabolism, SARS-CoV-2 metabolism, COVID-19 metabolism
- Abstract
Epidemiological evidence links lower air quality with increased incidence and severity of COVID-19; however, mechanistic data have yet to be published. We hypothesized air pollution-induced oxidative stress in the nasal epithelium increased viral replication and inflammation. Nasal epithelial cells (NECs), collected from healthy adults, were grown into a fully differentiated epithelium. NECs were infected with the ancestral strain of SARS-CoV-2. An oxidant combustion by-product found in air pollution, the environmentally persistent free radical (EPFR) DCB230, was used to mimic pollution exposure four hours prior to infection. Some wells were pretreated with antioxidant, astaxanthin, for 24 hours prior to EPFR-DCB230 exposure and/or SARS-CoV-2 infection. Outcomes included viral replication, epithelial integrity, surface receptor expression ( ACE2 , TMPRSS2 ), cytokine mRNA expression ( TNF-α , IFN-β ), intracellular signaling pathways, and oxidative defense enzymes. SARS-CoV-2 infection induced a mild phenotype in NECs, with some cell death, upregulation of the antiviral cytokine IFN-β , but had little effect on intracellular pathways or oxidative defense enzymes. Prior exposure to EPFR-DCB230 increased SARS-CoV-2 replication, upregulated TMPRSS2 expression, increased secretion of the proinflammatory cytokine TNF-α , inhibited expression of the mucus producing MUC5AC gene, upregulated expression of p21 (apoptosis pathway), PINK1 (mitophagy pathway), and reduced levels of antioxidant enzymes. Pretreatment with astaxanthin reduced SARS-CoV-2 replication, downregulated ACE2 expression, and prevented most, but not all EPFR-DCB230 effects. Our data suggest that oxidant damage to the respiratory epithelium may underly the link between poor air quality and increased COVID-19. The apparent protection by antioxidants warrants further research.
- Published
- 2023
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24. Collaborative Content-Dependent Modeling: A Return to the Roots of Salient Object Detection.
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Jiao S, Goel V, Navasardyan S, Yang Z, Khachatryan L, Yang Y, Wei Y, Zhao Y, and Shi H
- Abstract
Salient object detection (SOD) aims to identify the most visually distinctive object(s) from each given image. Most recent progresses focus on either adding elaborative connections among different convolution blocks or introducing boundary-aware supervision to help achieve better segmentation, which is actually moving away from the essence of SOD, i.e., distinctiveness/salience. This paper goes back to the roots of SOD and investigates the principles of how to identify distinctive object(s) in a more effective and efficient way. Intuitively, the salience of one object should largely depend on its global context within the input image. Based on this, we devise a clean yet effective architecture for SOD, named Collaborative Content-Dependent Networks (CCD-Net). In detail, we propose a collaborative content-dependent head whose parameters are conditioned on the input image's global context information. Within the content-dependent head, a hand-crafted multi-scale (HMS) module and a self-induced (SI) module are carefully designed to collaboratively generate content-aware convolution kernels for prediction. Benefited from the content-dependent head, CCD-Net is capable of leveraging global context to detect distinctive object(s) while keeping a simple encoder-decoder design. Extensive experimental results demonstrate that our CCD-Net achieves state-of-the-art results on various benchmarks. Our architecture is simple and intuitive compared to previous solutions, resulting in competitive characteristics with respect to model complexity, operating efficiency, and segmentation accuracy.
- Published
- 2023
- Full Text
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25. Disperse Layered Silicates in Magnesium Silicate Rocks
- Author
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Khachatryan, L. A.
- Published
- 2004
- Full Text
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26. Chemical Transformations in the Course of Solid-Phase Synthesis of Fibrous Alkali-Free Fluoroamphibole
- Author
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Khachatryan, L. A., Karakhanyan, S. S., and Grigor'eva, L. F.
- Published
- 2004
- Full Text
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27. Molecular modeling studies of the reactions of phenoxy radical dimers: Pathways to dibenzofurans
- Author
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Asatryan, R., Davtyan, A., Khachatryan, L., and Dellinger, B.
- Subjects
Molecular dynamics -- Research ,Dibenzofurans -- Chemical properties ,Dibenzofurans -- Structure ,Density functionals -- Usage ,Chemicals, plastics and rubber industries - Abstract
The results of density functional theory calculations for pathways of dibenzofuran formation from unsubstituted phenoxy radicals are reported. Intramolecular H-transfer within the (R,S) isomer leads to formation of a different stable intermediate, a 5-hydroxyl-4,5-cyclohexadiene-2,3-benzofuran (reaction HT-2), considered formally as dibenzofuran structure with out-of-plane H and OH moieties.
- Published
- 2005
28. Synthesis of new 6,7-dihydro-1H-cyclopenta[d]pyrimidine-2,4(3H,5H)-dione derivatives containing the substituted aliphatic ring
- Author
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Papoyan, R. F., Khachatryan, L. A., Panosyan, G. A., and Kochikyan, V. T.
- Published
- 2012
- Full Text
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29. Preparation of Nano/Microcapsules of Ozonated Olive Oil in Hyaluronan Matrix and Analysis of Physicochemical and Microbiological (Biological) Properties of the Obtained Biocomposite.
- Author
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Khachatryan G, Khachatryan L, Krystyjan M, Lenart-Boroń A, Krzan M, Kulik K, Białecka A, Grabacka M, Nowak N, and Khachatryan K
- Subjects
- Humans, Capsules, Hyaluronic Acid, Olive Oil, Hydrogels pharmacology, Hydrogels chemistry, Anti-Bacterial Agents pharmacology, Polymers chemistry, Anti-Infective Agents pharmacology, Ozone pharmacology
- Abstract
Hydrogels, based on natural polymers, such as hyaluronic acid, are gaining an increasing popularity because of their biological activity. The antibacterial effect of ozone is widely known and used, but the instability the gas causes, severely limits its application. Ozone entrapment in olive oil by its reaction with an unsaturated bond, allows for the formation of stable, therapeutically active ozone derivatives. In this study, we obtained an innovative hydrogel, based on hyaluronic acid containing micro/nanocapsules of ozonated olive oil. By combination of the biocompatible polymer with a high regenerative capacity and biologically active ingredients, we obtained a hydrogel with regenerative properties and a very weak inhibitory effect against both bacterial commensal skin microbiota and pathogenic Candida -like yeasts. We assessed the stability and rheological properties of the gel, determined the morphology of the composite, using scanning electron microscopy (SEM) and particle size by the dynamic light scattering (DLS) method. We also performed Attenuated total reflectance Fourier transform infrared (FTIR-ATR) spectroscopy. The functional properties, including the antimicrobial potential were assessed by the microbiological analysis and in vitro testing on the HaCat human keratinocyte cell line. The studies proved that the obtained emulsions were rheologically stable, exhibited an antimicrobial effect and did not show cytotoxicity in the HaCat keratinocyte model.
- Published
- 2022
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30. Revealing the Mechanism of Dioxin Formation from Municipal Solid Waste Gasification in a Reducing Atmosphere.
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Bei J, Xu X, Zhan M, Li X, Jiao W, Khachatryan L, and Wu A
- Subjects
- Atmosphere, Carbon Dioxide, Chlorine, Incineration, Solid Waste, Dioxins, Polychlorinated Dibenzodioxins
- Abstract
Gasification is an effective technology for the thermal disposal of municipal solid waste (MSW) with lower dioxin emission compared to the prevailing incineration process. Nevertheless, the mechanism of dioxin formation in the reducing atmosphere during the gasification process was seldomly explored. Herein, the effects of the atmosphere, temperature, and chlorine source were systematically investigated in terms of dioxin distribution. With CO
2 and H2 O as gasification agents, a reducing reaction atmosphere was formed with abundant H2 which effectively suppressed the generation of C-Cl, contributing to a substantial decrease of dioxin concentration by ∼80% compared to the incineration process. The formation of dioxin was favored at temperatures below 700 °C with its peak concentration achieved at 500 °C. It was unveiled that inorganic chlorine played a dominant role in the reducing atmosphere, with a lower proportion of C-O-C/O-C═O on residual slag compared to an oxidizing atmosphere. Additionally, the generated H2 reduced the concentration of dioxins by attacking C-Cl and inhibiting the crucial Deacon reaction for dioxin formation, validated by density functional theory calculation. Eventually, the formation route paradigm and the reaction mechanism of dioxin formation from MSW gasification were revealed, facilitating and rationally guiding the control of dioxin emission.- Published
- 2022
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31. UP-FRONT 2-CHLORDEOXYADENOSINE-BASED COMBINATION CHEMOTHERAPY IN HIGH-RISK LCH: EARLY RESULTS OF PILOT TRIAL
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Maschan, M., Novichkova, G., Baidildina, D., Khachatryan, L., Sinizina, V., Solopova, G., Petrova, U., and Maschan, A.
- Published
- 2009
32. SINGLE CASE OF PERICARDIAL EFFUSION IN PATIENT WITH FAMILIAL MEDITERRANEAN FEVER: P-280
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Simonyan, L. G. and Khachatryan, L. Ch.
- Published
- 2009
33. CORRECTION OF SLEEP DISORDERS IN CHILDREN.
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KHACHATRYAN, L. G., MAKSIMOVA, M. S., GEPPE, N. A., LEMESHKO, I. D., KASANAVE, E. V., and TREPILETZ, V. M.
- Subjects
SLEEP disorders in children ,BEHAVIOR therapy ,ANXIETY in children ,FATIGUE (Physiology) ,PEDIATRICS - Abstract
The article is devoted to a critical theme: sleep disorders in children. An open, prospective, randomized, comparative, controlled observational study was performed in the representative group of 114 patients aged 6 months to 2.5 years with sleep and sleep initiation disorders, where 64 patients received treatment with Dormikind and 50 patients received behavioral therapy for 28 days. It was reliably proved that sleep initiation reduced by 1.7 times and reached 26.2±4.8 (95% CI, 25.0-27.4) minutes in the main group. The number of children sleeping on hands dropped by 8.7 times and by 2 times in the parents' bed in the main group, according to Brief Infant Sleep Questionnaire scale, in the control group the same characteristics changed by 1.1, 1.3 and 1.5 times, correspondingly, and sleep initiation reached 33.4±2.9 (95% CI, 32.6-34.2), U-criteria, U=742.5 (p<0.001). The number of patients rocked to sleep in their own beds increased by 3.2 times (vs. 1.2 times in the control group) on the background of treatment with Dormikind. Duration of night sleep increased on average by 1.5 ±0.96 (95% CI, 1.26-1.74) hours; in the control group -- by 0.5±0.81 (95% CI, 0.27-0.73) hours (U-criteria, U=383.5; p<0.001) and frequency of awakening reduced by 2.1 times and reached 1.8±0.7 (95% CI, 1.6-2.0) hours. In the control group frequency of awakening reduced only by 1.2 times in average and reached 2.8±0.7 (95% CI, 2.6-3.1), U-criteria, U=579.5; p<0.001. Significant positive dynamics was noted in the emotional-behavioral state of children after therapy: decreased irritation, excitability, fatigue, anxiety and till the end of treatment total score significantly improved by almost 3 times (1.3 times in the control group, that is 2.8±0.7, 95% CI, 2.6-3.0; U-criteria, U=266.0, p<0.001) and reached 1.3±0.7 (95% CI, 1.1-1.5) in the main group. According to positive dynamics in all sleep parameters, IMOS score showed significant difference in groups concerning valuation: "total recovery" -- 31% (20 patients) in Dormikind group and 0% in the control one (F-criteria, p=0.0008). Valuation "significant improvement" -- 58% (37 patients) in the main group vs. 10% (5 patients) in the control, valuation "improvement" -- 6% (4 patients) in the main group vs. 46% (23 patients) in the control. Parents noticed absence of dynamics only in 5% (3 patients) in the main group vs. 38% in the control and in 3 children of the control group parents noticed worsening of the state after therapy. Thus, the high efficacy and safety of Dormikind were verified, and it can be recommended for wide use in pediatric healthcare practice. [ABSTRACT FROM AUTHOR]
- Published
- 2018
34. Crowdsourced benchmarking of taxonomic metagenome profilers: lessons learned from the sbv IMPROVER Microbiomics challenge.
- Author
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Poussin C, Khachatryan L, Sierro N, Narsapuram VK, Meyer F, Kaikala V, Chawla V, Muppirala U, Kumar S, Belcastro V, Battey JND, Scotti E, Boué S, McHardy AC, Peitsch MC, Ivanov NV, and Hoeng J
- Subjects
- Benchmarking, Metagenomics methods, Software, Crowdsourcing, Metagenome
- Abstract
Background: Selection of optimal computational strategies for analyzing metagenomics data is a decisive step in determining the microbial composition of a sample, and this procedure is complex because of the numerous tools currently available. The aim of this research was to summarize the results of crowdsourced sbv IMPROVER Microbiomics Challenge designed to evaluate the performance of off-the-shelf metagenomics software as well as to investigate the robustness of these results by the extended post-challenge analysis. In total 21 off-the-shelf taxonomic metagenome profiling pipelines were benchmarked for their capacity to identify the microbiome composition at various taxon levels across 104 shotgun metagenomics datasets of bacterial genomes (representative of various microbiome samples) from public databases. Performance was determined by comparing predicted taxonomy profiles with the gold standard., Results: Most taxonomic profilers performed homogeneously well at the phylum level but generated intermediate and heterogeneous scores at the genus and species levels, respectively. kmer-based pipelines using Kraken with and without Bracken or using CLARK-S performed best overall, but they exhibited lower precision than the two marker-gene-based methods MetaPhlAn and mOTU. Filtering out the 1% least abundance species-which were not reliably predicted-helped increase the performance of most profilers by increasing precision but at the cost of recall. However, the use of adaptive filtering thresholds determined from the sample's Shannon index increased the performance of most kmer-based profilers while mitigating the tradeoff between precision and recall., Conclusions: kmer-based metagenomic pipelines using Kraken/Bracken or CLARK-S performed most robustly across a large variety of microbiome datasets. Removing non-reliably predicted low-abundance species by using diversity-dependent adaptive filtering thresholds further enhanced the performance of these tools. This work demonstrates the applicability of computational pipelines for accurately determining taxonomic profiles in clinical and environmental contexts and exemplifies the power of crowdsourcing for unbiased evaluation., (© 2022. The Author(s).)
- Published
- 2022
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35. Metal-Free Biomass-Derived Environmentally Persistent Free Radicals (Bio-EPFRs) from Lignin Pyrolysis.
- Author
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Khachatryan L, Barekati-Goudarzi M, Asatryan R, Ozarowski A, Boldor D, Lomnicki SM, and Cormier SA
- Abstract
To assess contribution of the radicals formed from biomass burning, our recent findings toward the formation of resonantly stabilized persistent radicals from hydrolytic lignin pyrolysis in a metal-free environment are presented in detail. Such radicals have particularly been identified during fast pyrolysis of lignin dispersed into the gas phase in a flow reactor. The trapped radicals were analyzed by X-band electron paramagnetic resonance (EPR) and high-frequency (HF) EPR spectroscopy. To conceptualize available data, the metal-free biogenic bulky stable radicals with extended conjugated backbones are suggested to categorize as a new type of metal-free environmentally persistent free radicals (EPFRs) (bio-EPFRs). They can be originated not only from lignin/biomass pyrolysis but also during various thermal processes in combustion reactors and media, including tobacco smoke, anthropogenic sources and wildfires (forest/bushfires), and so on. The persistency of bio-EPFRs from lignin gas-phase pyrolysis was outlined with the evaluated lifetime of two groups of radicals being 33 and 143 h, respectively. The experimental results from pyrolysis of coniferyl alcohol as a model compound of lignin in the same fast flow reactor, along with our detailed potential energy surface analyses using high-level DFT and ab initio methods toward decomposition of a few other model compounds reported earlier, provide a mechanistic view on the formation of C- and O-centered radicals during lignin gas-phase pyrolysis. The preliminary measurements using HF-EPR spectroscopy also support the existence of O-centered radicals in the radical mixtures from pyrolysis of lignin possessing a high g value (2.0048)., Competing Interests: The authors declare no competing financial interest., (© 2022 The Authors. Published by American Chemical Society.)
- Published
- 2022
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36. Combinatorial Approach to the Description of Random Fields.
- Author
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Khachatryan, L. A. and Nahapetian, B. S.
- Abstract
We develop a combinatorial approach to the description of lattice random fields with general (Polish) state space. This approach based on so-called P-functions, which can be interpreted as a system of limiting correlation functions. We suggest a method of construction of P-functions, which can be applied in the theory of Gibbs random fields. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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- View/download PDF
37. THE ASSESSMENT OF TOTAL SUSPENDED PARTICLE MITIGATION POTENTIAL OF PLATANUS ORIENTALIS AND FRAXINUS EXCELSIOR IN YEREVAN CONDITIONS.
- Author
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Khachatryan, L. R.
- Subjects
- *
EUROPEAN ash , *SYCAMORES , *GREEN infrastructure , *AIR pollution , *SPECIES - Abstract
The aim of the presented research was to study and assess Total Suspended Particle mitigation capacity of Fraxinus excelsior and Platanus orientalis - the two most widespread tree species in Yerevan. It turned out that in the conditions of Yerevan, both tree species show high efficiency of TSP mitigation. In this regard, we recommend using P. orientalis and F. excelsior in Yerevan green infrastructure as wide as possible, especially along the highways, in the industrial areas of the city, and in areas with intensive construction. [ABSTRACT FROM AUTHOR]
- Published
- 2021
38. Syncope in a pregnant woman with repaired Tetralogy of Fallot: a case report.
- Author
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Ghazaryan N, Adamyan M, Khachatryan L, and Hovakimyan T
- Abstract
Background: Tetralogy of Fallot (TOF) is one of the most widespread cyanotic congenital heart disease (CHD), which can be successfully repaired in the neonatal period. However, residual problems and the surgical technique itself can create a favourable basis for arrhythmias and conduction abnormalities in these patients. Sometimes, these arrhythmias may worsen during pregnancy and require urgent intervention., Case Summary: This is a case of a 25-year-old woman, who underwent a surgical repair of TOF at the age of 2 years. She suffered an ischaemic stroke postoperatively, which was complicated with secondary seizures and syncope. These episodes were evaluated as epilepsy. The patient was admitted to our hospital with the above-mentioned complaints in the 10th week of pregnancy. A comprehensive cardiac examination was performed. Her presyncopal event was captured during Holter monitoring, which documented a severe dysfunction of the sinus node. She was diagnosed with postoperative sick sinus syndrome and implanted with a permanent dual-chamber pacemaker (PM). After the operation, the patient did not have any episodes of syncope or seizures and the PM check-up showed almost 30% of atrial pacing., Conclusion: No matter how obvious the neurological or other nature of syncope may seem, it is advised to exclude the cardiac origin of syncope, especially in patients with repaired CHD. One of the most common complications after surgery of CHD is rhythm and conduction disturbances. In some of these cases, permanent PM implantation can be unavoidable, even during pregnancy. The implantation of the PM device during pregnancy can be performed safely., (© The Author(s) 2022. Published by Oxford University Press on behalf of the European Society of Cardiology.)
- Published
- 2022
- Full Text
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39. Investigation of gasification kinetics of multi-component waste mixtures in a novel thermogravimetric flow reactor via gas analysis.
- Author
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Mărculescu C, Tîrţea RN, Khachatryan L, and Boldor D
- Subjects
- Food, Kinetics, Plastics, Temperature, Refuse Disposal
- Abstract
A novel gasification fed-batch reactor enabling both thermogravimetric and gas analysis of large samples (up to tens of grams) was designed and tested. Air gasification experiments on food-court waste representative samples and its components were performed at 700 °C and 800 °C using ER = 0.3. At both temperatures, the lignocellulosics fraction produced highest H
2 concentration (greater than 21% at 800 °C) while the plastic components generated less H2 regardless of process temperature (2.44%-7.08%). Synergistic effects of multiple components gasification with respect to H2 production was noticed through its non-linear evolution at 700 °C (ranging from 1.18% to 5.38%). A strong negative effect was observed at 800 °C; plastic addition reduced H2 production when combined with lignocellulosic and organic matter (1.02% to 9.73%). The same effects were observed for CH4 formation. This phenomenon was validated by kinetic analysis of decay curves of all components and their mixtures at the beginning of gasification in entire temperature region., (Copyright © 2021 Elsevier Ltd. All rights reserved.)- Published
- 2022
- Full Text
- View/download PDF
40. COMMUNITY STRUCTURE AND ECOSYSTEM SERVICES OF TREES OF THE FIRST SECTION OF CIRCULAR PARK IN YEREVAN, ARMENIA.
- Author
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Khachatryan, L. R.
- Subjects
- *
CARBON sequestration , *AIR pollution , *TREES , *ECOSYSTEM services - Abstract
The article considers the results of the study on community structure and ecosystem services of trees of the first section of Circular Park - one of the largest parks in Yerevan, Armenia. Totally 757 trees, representing 27 species were identified. The results of the tree condition assessment indicated that 55% of the examined trees were in poor condition. Across all trees, the most common diameter at breast height (hereafter referred to as DBH) and height respectively fell within the 16-30 cm and 6-11 m size classes, which reflects the presence of a high number of middle-aged trees. The data obtained via i-Tree canopy showed that the combined air pollution removal ecosystem service for trees was valued at approximately $1.290, for carbon storage and sequestration - $32,815. [ABSTRACT FROM AUTHOR]
- Published
- 2021
41. Current problems of the agricultural market and development prospects on an example of the Republic of Armenia.
- Author
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KHACHATRYAN, L. R.
- Subjects
AGRICULTURAL marketing ,AGRICULTURAL development ,FARM produce ,VALUE-added tax ,AGRICULTURAL technology - Abstract
Copyright of Ekonomika APK is the property of Economy of Argo-Industrial Complex and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2019
- Full Text
- View/download PDF
42. Formation and Investigation of Physicochemical, Biological and Bacteriostatic Properties of Nanocomposite Foils Containing Silver Nanoparticles and Graphene Oxide in Hyaluronic Acid Matrix.
- Author
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Khachatryan K, Khachatryan L, Krzan M, Krystyjan M, Krzemińska-Fiedorowicz L, Lenart-Boroń A, Koronowicz A, Drozdowska M, and Khachatryan G
- Abstract
Natural polysaccharides, including hyaluronic acid, find a wide range of applications in biomedical sciences. There is a growing interest in nanocomposites containing hyaluronic acid and nanoparticles such as nanometals or graphene. In this study, we prepared foils of pure sodium hyaluronate and sodium hyaluronate containing nanosilver, graphene oxide, nanosilver/graphene oxide and characterized their properties. UV-vis spectroscopy and scanning electron microscopy (SEM) confirmed the formation of 10-20 nm silver nanoparticles. The structural changes were investigated using Fourier transforms infrared (FTIR) spectra and size exclusion chromatography. The obtained results suggest changes in molecular weights in the samples containing nanoparticles, which was highest in a sample containing nanosilver/graphene oxide. We also assessed the mechanical properties of the foils (thickness, tensile strength and elongation at break) and their wettability. The foils containing nanosilver and nanosilver/graphene oxide presented bacteriostatic activity against E. coli , Staphylococcus spp. and Bacillus spp., which was not observed in the control and sample containing graphene oxide. The composites containing graphene oxide and nanosilver/graphene oxide exhibited a cytotoxic effect on human melanoma WM266-4 cell lines (ATCC, Manassas, VA, USA).
- Published
- 2021
- Full Text
- View/download PDF
43. Evidence for chemical burns by white phosphorus in Armenian soldiers during the 2020 Nagorno-Karabakh war.
- Author
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Brutyan S, Babayan K, Barseghyan N, Petrosyan V, Knipper P, Bégué T, Khachatryan L, and Khonsari RH
- Subjects
- Armenia, Humans, Phosphorus, Burns, Chemical, Military Personnel
- Published
- 2021
- Full Text
- View/download PDF
44. Relationships between circulating galectin-3, extracellular matrix fibrosis and outcomes in dilated cardiomyopathy.
- Author
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Rubiś P, Holcman K, Dziewięcka E, Wiśniowska-Śmiałek S, Karabinowska A, Szymonowicz M, Khachatryan L, Wypasek E, Garlitski A, Gackowski A, and Podolec P
- Subjects
- Adult, Biomarkers, Extracellular Matrix pathology, Fibrosis, Galectin 3, Humans, Middle Aged, Myocardium pathology, Cardiomyopathy, Dilated
- Abstract
Background: Galectin-3 is an emerging biomarker in cardiovascular disease. Myocardial galectin-3 is involved in the pathology of cardiac fibrosis; however, the role of circulating galectin-3 is not yet established., Objectives: To assess the relationships between circulating galectin-3, fibrosis and outcomes in dilated cardiomyopathy (DCM)., Material and Methods: We included 70 patients (age: 48 ±12.1 years, ejection fraction (EF) 24.4 ±7.4%) with new-onset DCM (n = 35, ≤6 months). Galectin-3 and procollagen type I and III (PICP, PINP, PIIICP, and PIIINP), transforming growth factor β (TGF-β), connective tissue growth factor (CTGF), osteopontin (OPN), matrix metalloproteinases (MMP-2 and -9), and tissue inhibitor (TIMP-1) were determined in serum at baseline and after 3 and 12 months. Patients underwent endomyocardial biopsy. The endpoint was a combination of death and urgent hospitalization at 12 months., Results: Galectin-3 did not correlate with biopsy-determined fibrosis. Baseline galectin-3 correlated with OPN,, TIMP-1, PIIICP, and MMP-2. In new-onset DCM, galectin-3 levels at baseline were higher than at 3 and 12 months, whereas in chronic DCM there was no difference. Galectin-3 was a predictor of the endpoint (hazard ratio (HR) = 1.115; 95% confidence interval (95% CI) = 1.009-1.231; p < 0.05). The best cut-off value was 14.54 ng/mL (area under the curve (AUC) = 0.67). Patients with galectin-3 ≥14.54 ng/mL had an increased risk of events (HR = 2.569; 95% CI = 1.098-6.009; p < 0.05)., Conclusions: Circulating galectin-3 is unrelated to fibrosis. Serial measurements of galectin-3 correlated with markers of fibrosis, including markers of collagen synthesis and OPN. Circulating galectin-3 was independently associated with cardiovascular (CV) outcomes in DCM.
- Published
- 2021
- Full Text
- View/download PDF
45. Inflammatory Bowel Disease-Associated Changes in the Gut: Focus on Kazan Patients.
- Author
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Lo Sasso G, Khachatryan L, Kondylis A, Battey JND, Sierro N, Danilova NA, Grigoryeva TV, Markelova MI, Khusnutdinova DR, Laikov AV, Salafutdinov II, Romanova YD, Siniagina MN, Vasiliev IY, Boulygina EA, Solovyeva VV, Garanina EE, Kitaeva KV, Ivanov KY, Chulpanova DS, Kletenkov KS, Valeeva AR, Odintsova AK, Ardatskaya MD, Abdulkhakov RA, Ivanov NV, Peitsch MC, Hoeng J, and Abdulkhakov SR
- Subjects
- Feces, Humans, Tatarstan, Dysbiosis ethnology, Fatty Acids, Volatile, Gastrointestinal Microbiome, Inflammatory Bowel Diseases ethnology
- Abstract
Background: Several studies have highlighted the role of host-microbiome interactions in the pathogenesis of inflammatory bowel disease (IBD), resulting in an increasing amount of data mainly focusing on Western patients. Because of the increasing prevalence of IBD in newly industrialized countries such as those in Asia, the Middle East, and South America, there is mounting interest in elucidating the gut microbiota of these populations. We present a comprehensive analysis of several IBD-related biomarkers and gut microbiota profiles and functions of a unique population of patients with IBD and healthy patients from Kazan (Republic of Tatarstan, Russia)., Methods: Blood and fecal IBD biomarkers, serum cytokines, and fecal short-chain fatty acid (SCFA) content were profiled. Finally, fecal microbiota composition was analyzed by 16S and whole-genome shotgun sequencing., Results: Fecal microbiota whole-genome sequencing confirmed the presence of classic IBD dysbiotic features at the phylum level, with increased abundance of Proteobacteria, Actinobacteria, and Fusobacteria and decreased abundance of Firmicutes, Bacteroidetes, and Verrucomicrobia. At the genus level, the abundance of both fermentative (SCFA-producing and hydrogen (H2)-releasing) and hydrogenotrophic (H2-consuming) microbes was affected in patients with IBD. This imbalance was confirmed by the decreased abundance of SCFA species in the feces of patients with IBD and the change in anaerobic index, which mirrors the redox status of the intestine., Conclusions: Our analyses highlighted how IBD-related dysbiotic microbiota-which are generally mainly linked to SCFA imbalance-may affect other important metabolic pathways, such as H2 metabolism, that are critical for host physiology and disease development., (© 2020 Crohn’s & Colitis Foundation. Published by Oxford University Press on behalf of Crohn’s & Colitis Foundation.)
- Published
- 2021
- Full Text
- View/download PDF
46. Factors associated with unfavourable treatment outcomes among people with rifampicin-resistant tuberculosis in Armenia, 2014-2017.
- Author
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Khachatryan L, Grigoryan R, Dadu A, Kumar AMV, Akopyan K, Dumchev K, Harutyunyan H, and Matteelli A
- Subjects
- Antitubercular Agents therapeutic use, Armenia epidemiology, Cohort Studies, Humans, Male, Middle Aged, Treatment Outcome, Rifampin therapeutic use, Tuberculosis, Multidrug-Resistant drug therapy, Tuberculosis, Multidrug-Resistant epidemiology
- Abstract
Rifampicin-Resistant/Multidrug-Resistant Tuberculosis (RR/MDR-TB) is recognized as a major public health concern globally. In Armenia, the proportion of RR/MDR-TB is increasing among all people affected with TB. We conducted a nationwide cohort study involving analysis of programmatic data to investigate the rates of and factors associated with unfavourable treatment outcomes among patients with RR/MDR-TB registered by the national TB programme from 2014 to 2017 in Armenia. We used Cox regression to identify factors associated with the outcome. Among 451 RR/MDR-TB patients, 80% were men and median age was 46 years. Of them, 53 (11.8%) had Extensively Drug-Resistant Tuberculosis (XDR-TB) and 132 (29.3%) had pre-XDR-TB. Almost half (224, 49.7%) of the patients had unfavourable treatment outcome, which included 26.8% Loss To Follow-Up (LTFU), 13.3% failures and 9.5% deaths. In multivariable analysis, people with pre-XDR-TB [adjusted Hazard Ratio [aHR] 3.13, 95% confidence intervals [CI] 2.16-4.55] and XDR-TB (aHR 4.08, 95% CI 2.45-6.79) had a higher risk of unfavourable outcomes. Patients receiving home-based treatment (71/451, 15.7%) and treatment with new drugs (172/451, 38.1%) had significantly lower risk (aHR 0.45, 95% CI 0.28-0.72 and aHR 0.26, 95% CI 0.18-0.39) of unfavourable treatment outcome. The proportion of MDR-TB patients reaching favourable treatment outcome in Armenia was substantially lower than the recommended level (75%). The most common treatment outcome was LTFU indicating the need for further assessment of underlying determinants. Home-based treatment looks promising and future studies are required to see if expanding it to all RR/MDR-TB patients is feasible and cost-effective.
- Published
- 2021
- Full Text
- View/download PDF
47. OH-Initiated Reactions of para -Coumaryl Alcohol Relevant to the Lignin Pyrolysis. Part II. Kinetic Analysis.
- Author
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Hudzik JM, Barekati-Goudarzi M, Khachatryan L, Bozzelli JW, Ruckenstein E, and Asatryan R
- Abstract
Monolignols are precursor units and primary products of lignin pyrolysis. The currently available global (lumped) and semidetailed kinetic models, however, are lacking the comprehensive decomposition kinetics of these key intermediates in order to advance toward the fundamentally based detailed chemical-kinetic models of biomass pyrolysis. para -Coumaryl alcohol (HOPh-CH═CH-CH
2 OH, p -CMA) is the simplest of the three basic monolignols containing a typical side-chain double bond and both alkyl and phenolic type OH groups. The two other monomers additionally contain one and two methoxy groups, respectively, attached to the benzene ring. Previously, we developed a detailed fundamentally based mechanism for unimolecular decomposition of p -CMA (as well as its truncated allyl and cinnamyl alcohol models) and explored its reactivity toward H radicals generated during pyrolysis. The reactions of p -CMA with pyrolytic OH radicals is another set of key reactions particularly important for understanding the formation mechanisms of a wide variety of oxygenates in oxygen-deficit (anaerobic) conditions and the role of the lignin side groups in pyrolysis pathways. In Part I of the current study ( J. Phys. Chem. A, 2019, 123, 2570-2585), we reported a detailed potential energy (enthalpy) surface analysis of the reaction OH + p -CMA with suggestions for a variety of chemically activated, unimolecular, and bimolecular reaction pathways. In Part II of our work, we provide a detailed kinetic analysis of the major reaction channels to evaluate their significance and possible impacts on product distributions. Temperature- and pressure-dependent rate constants are calculated using the quantum Rice-Ramsperger-Kassel method and the master equation analysis for falloff and stabilization. Enthalpies of formation, entropies, and heat capacities are calculated using density functional theory and higher-level composite methods for stable molecules, radicals, and transition-state species. A significant difference between well depths for the chemically activated adduct radicals, [ p -CMA-OH]*, is found for the α- and β-carbon addition reactions to generate the 1,3- and 1,2-diol radicals, respectively. This is due to the synergistic effect from conjugation of the proximal radical center with the aromatic ring and the strong H-bonding interaction between vicinal OH groups in the β-adduct (1,2-diol radical). Both adducts undergo isomerization and low-energy transformations, however, with different kinetic efficiencies because of the difference in stabilization energies. Reaction pathways include dissociation, intramolecular abstraction, atom and group transfers, and elimination. Of particular interest is a roaming-like low-energy dehydration reaction to form O-centered intermediate radicals. The kinetic analysis demonstrated the feasible formation of various products detected in pyrolysis experiments, suggesting that the gas-phase reactions of OH radicals can be a key process to form major products and complex oxygenates during lignin pyrolysis. Our preliminary experiments involving pyrolysis of the vaporized monomers support this basic statement. A novel mechanism for the formation of benzofuran, identified in experimentation, is also provided based on the potential conversions of hydroxyphenylacetaldehyde and corresponding isomers, which are kinetically favored products.- Published
- 2020
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48. Comparative Studies of Environmentally Persistent Free Radicals on Total Particulate Matter Collected from Electronic and Tobacco Cigarettes.
- Author
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Hasan F, Khachatryan L, and Lomnicki S
- Subjects
- Free Radicals analysis, Particulate Matter, Nicotiana, Electronic Nicotine Delivery Systems, Tobacco Products
- Abstract
In the current study, electron paramagnetic resonance (EPR) spectroscopy was employed to measure environmentally persistent free radicals (EPFRs) in the total particulate matter (TPM) of mainstream and sidestream TPM of conventional cigarettes and the TPM of e-cigarettes. Comparable concentrations of EPFRs were detected in both sidestream (8.05 ± 1.32) × 10
4 pmol/g and mainstream TPM (7.41 ± 0.85) × 104 pmol/g of conventional cigarettes. TPM exposure to air resulted in long-lived oxygen centered, secondary radicals with EPR g values of 2.0041 for mainstream and 2.0044 for sidestream. Surprisingly, despite no combustion process, the TPM from e-cigarettes (menthol flavor of NJOY and V2 brands) also contain EPFRs with g values of 2.0031-2.0033, characteristic of carbon centered radicals, while the radical signal in the vanilla flavor of V2 brand was remarkably similar to semiquinones in cigarette smoke with a higher g value (2.0063). The radical concentration in e-cigarettes was much lower as compared to tobacco TPM. Although the production of ROS generated by e-cigarettes is comparatively lower than ROS generated by conventional cigarettes, EPFRs in e-cigarettes appear to be more potent than those in tobacco TPM with respect to hydroxyl radical generation yield per unit EPFR. EPFRs in e-cigarette TPM may be a potential source of health impacts.- Published
- 2020
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49. Taxonomic classification and abundance estimation using 16S and WGS-A comparison using controlled reference samples.
- Author
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Khachatryan L, de Leeuw RH, Kraakman MEM, Pappas N, Te Raa M, Mei H, de Knijff P, and Laros JFJ
- Subjects
- Datasets as Topic, High-Throughput Nucleotide Sequencing, Metagenomics, Real-Time Polymerase Chain Reaction, Bacteria classification, Bacteria genetics, RNA, Ribosomal, 16S genetics, Whole Genome Sequencing
- Abstract
The assessment of microbiome biodiversity is the most common application of metagenomics. While 16S sequencing remains standard procedure for taxonomic profiling of metagenomic data, a growing number of studies have clearly demonstrated biases associated with this method. By using Whole Genome Shotgun sequencing (WGS) metagenomics, most of the known restrictions associated with 16S data are alleviated. However, due to the computationally intensive data analyses and higher sequencing costs, WGS based metagenomics remains a less popular option. Selecting the experiment type that provides a comprehensive, yet manageable amount of information is a challenge encountered in many metagenomics studies. In this work, we created a series of artificial bacterial mixes, each with a different distribution of skin-associated microbial species. These mixes were used to estimate the resolution of two different metagenomic experiments - 16S and WGS - and to evaluate several different bioinformatics approaches for taxonomic read classification. In all test cases, WGS approaches provide much more accurate results, in terms of taxa prediction and abundance estimation, in comparison to those of 16S. Furthermore, we demonstrate that a 16S dataset, analysed using different state of the art techniques and reference databases, can produce widely different results. In light of the fact that most forensic metagenomic analysis are still performed using 16S data, our results are especially important., (Copyright © 2020. Published by Elsevier B.V.)
- Published
- 2020
- Full Text
- View/download PDF
50. Functional properties of composites containing silver nanoparticles embedded in hyaluronan and hyaluronan-lecithin matrix.
- Author
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Khachatryan G, Khachatryan K, Krystyjan M, Krzan M, and Khachatryan L
- Subjects
- Gels chemical synthesis, Hyaluronic Acid chemical synthesis, Rheology, Silver chemistry, Gels chemistry, Hyaluronic Acid chemistry, Lecithins chemistry, Metal Nanoparticles chemistry
- Abstract
The rapid progress of nanotechnology triggers the development of nanomedicine. As the antimicrobial properties of nanosilver are well known, there is a huge interest in the synthesis of silver nanoparticles using environmentally-friendly methods. In this study we described the functional (rheological, mechanical, surface, structural) properties of gels and foils containing silver nanoparticles embedded in hyaluronan and hyaluronan-lecithin matrix prepared using the methods of green chemistry. The study showed that the addition of silver strengthened the structure of Hyal foil, but reduced the stretch of the sample and that lecithin weakened the mechanical properties of the composites. Also, the presence of nanosilver made the studied foils partially hydrophilic, while these with lecithin were more hydrophobic. The results of the study are significant for the adaptation of the investigated materials to their potential applications., (Copyright © 2020 Elsevier B.V. All rights reserved.)
- Published
- 2020
- Full Text
- View/download PDF
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