Computer Quantum-Chemical Simulation of Polymeric Stabilization of Silver Nanoparticles

Severe hemostatic disorders against the background of COVID-19 have a significant effect on the state of dental status. The study aimed to improve the effectiveness of dental care for patients with COVID-19 disease. To study the dental status of patients with COVID-19 undergoing inpatient treatment, to compare the change in saliva pH with the results of SARS-CoV-2 detection in paired nasopharyngeal smears and saliva samples, to study the microcirculation and oxygenation level of periodontal tissues in patients with moderate and severe COVID-19 undergoing inpatient treatment. 194 people were examined, including 112 patients with the new COVID 19 coronavirus infection and 82 comparison group without concomitant pathology. All patients are divided into five age groups according to their recommendations. The complex of examination included assessment of dental status, determination of saliva pH, the study of microcirculation and oxygenation in the periodontium, and on the phalanx of the index finger of the right hand. Analysis of the results of the study shows that when assessing the dental status, the most characteristic complaints were dryness of the oral cavity, ageusia or hypogeusia, anosmia, or hyposmia. Gum bleeding was observed in two older age groups: in patients aged 45-54 years in 20% of cases, in 55-64 years -18.5% of cases. Less than a quarter of the patients complained of hypersensitivity of the teeth. The study of the saliva pH level revealed normal indicators of the acid-base balance of the oral cavity, which did not depend on the results of the PCR test for COVID-19.

Section: Introductionmentioning

confidence: 99%

Tissue Dental Status and Features of Periodontal Microcirculation in Patients with New COVID-19 Coronavirus Infection.

Remizova¹,

Dzgoeva²,

Tingaeva³

et al. 2021

“…As a result of quantum chemical modeling, it was found that silver nanoparticles can interact with the following amino acids: Proline, glutamine, lysine, arginine, asparagine, histidine, glutamic and aspartic acids, tryptophan, and cysteine, which is due to the presence of additional -NH2, -NH, -SH and -COOH groups in these amino acids that are not involved in the formation of a peptide bond. These free additional groups make possible interaction with nanosilver [23,47]. Thus, the interaction of silver nanoparticles with threonine, serine, and tyrosine is unlikely.…”

Section: Resultsmentioning

confidence: 99%

“…The calculation was performed on the equipment of the Data Processing Center (Schneider Electric) of the North Caucasus Federal University. Calculation characteristics: Energy, method -B3LYP; basis -3-21G, convergence-5, force field-Ghemic [47][48][49]. Amino acids were considered as the target of nanosilver.…”

Section: Methodsmentioning

confidence: 99%

Computed Quantum Chemical Modeling of the Effect of Nanosilver on Coronavirus COVID-1

Mishununa¹,

Chapanov²,

Gakaeva³

et al. 2021

This article presents an analysis of available scientific data on the morphology and nanostructure of the COVID-19 coronavirus. Possible mechanisms of influence of nanosilver particles on the coronavirus are considered. Models of nanosilver complexes with spike protein of coronavirus amino acids were constructed using computer quantum-chemical modeling. The values of electron density distribution, highest occupied molecular orbital, lowest unoccupied molecular orbital, and electron density distribution gradient for each constructed model are obtained. As a result of quantum chemical modeling, it was found that silver nanoparticles can interact with the following amino acids: Proline, glutamine, lysine, arginine, asparagine, histidine, glutamic and aspartic acids, tryptophan, and cysteine, which is due to the presence of additional -NH2, -NH, -SH and -COOH groups in these amino acids that are not involved in the formation of a peptide bond. The freedom of additional groups makes it possible to interact with nanosilver. Analysis of the obtained data showed that the most energy-efficient interaction is the formation of the "tryptophan-nanosilver" complex (E= -5856.83 kcal/mol). Based on the findings of quantum chemical calculations, the most stable complex is the "cysteine-nanosilver" (ΔE = 0.16 a.u).

“…The functions of these programs are sometimes not enough to perform more complex work with the obtained data, including differentiation of tumors in various diseases [8][9][10]. The creation of 3D models of organs on these programs is quite successful, but it requires a little more time and additional resources [11][12][13]. Also, the software used is not able to create 3D models of the internal structure of organs if the images were obtained without the use of contrast agents [14][15][16][17].…”

Section: Introductionmentioning

confidence: 99%

Computer-Assisted Surgery: Virtual- and Augmented-Reality Displays for Navigation During Planning and Performing Surgery on Large Joints

Mishvelov¹,

Ibragimov²,

Amaliev³

et al. 2021

Today, a small number of full-fledged multifunctional CT systems are used for planning intraoperative intervention using mixed reality, for example, in cardiovascular surgery and urology, especially in Oncology. Surgeons today need a wide field of view to operate. Currently, the use of technologies like the DaVinci robot surgeon is constrained by the bulkiness of software and hardware solutions, the lack of trained specialists, and the high cost of equipment. There is no technology for navigating the course of the operation, with a layer of mixed reality being applied to the patient during the operation, so that the surgeon can use it to track the position of the organ, organ systems, and surgical instruments in real-time. The developed software prototype allows you to create three-dimensional models of internal organs based on computer and magnetic resonance imaging images with the possibility of simulating surgical intervention. Augmented reality glasses are also used to practice the skills of operations on a virtual patient using phantom dummies, linking surgical instruments to holography, as well as fully combining the simulation of the preoperative period with a real patient in real-time.