Molecular-pathophysiological aspects of post-COVID syndrome

Introducere. Pandemia COVID-19 a afectat oameni din întreaga lume, dar chiar și după ce au experimentat această infecție virală, 60 până la 87% dintre supraviețuitorii COVID-19 vor avea simptome clinice pe termen lung combinate în sindromul post-COVID. Scopul lucrării. Elucidarea aspectelor moleculare și fiziopatologice ale sindromului Post-COVID (SPC). Material și metode. Articole au fost selectate din următoarele surse: PubMed, Hinari, Google Scholar. Au fost studiate peste 140 de publicații legate de acest subiect. Au fost incluse publicații actuale în perioada anilor 2012-2023. Rezultate. Ținta principală pentru virusul SARS-CoV-2 sunt celule care au pe suprafața sa receptorii ACE-2. În timpul COVID19, la nivel molecular, apare hiperactivarea patologică a sistemului renină-angiotensină-aldosteron - ducând la activarea sistemului nervos simpatic și agravând starea răspunsului imun, alături de aceasta există o expresie activă a genelor de citokine, chemokine și celule imune și are loc o cascadă de citokine, ceea ce duce la o mai mare activare a sistemului nervos simpatic. Există un efect de potențare reciprocă vegetativ-imunitară, care duce la un proces inflamator pe termen lung în corpul uman, chiar și după eliberarea completă a virusului SARS-CoV-2 și epuizarea sistemului nervos parasimpatic. Componenta vegetativă explică astfel de simptome clinice precum: oboseală cronică, insomnie, atacuri de panică etc. Componenta imunitară a sindromului post-COVID poate fi dovedită folosind secvențierea ARN pentru a determina schimbarea transcriptomului după COVID19 sau prin detectarea biomarkerilor precum CRP, IL-6 și TNF-alfa pentru o lungă perioadă de timp. Concluzii. Cunoașterea mecanismelor moleculare și patofiziologice ale sindromului post-COVID ar facilita diagnosticarea și tratamentul acestor pacienți.Background. The COVID-19 pandemic has impacted people worldwide, and a significant number of COVID-19 survivors, ranging from 60% to 87%, continue to experience long-term clinical symptoms known as post-COVID syndrome. Objective of the study. Evaluation of the molecular and pathophysiological aspects of Post-COVID Syndrome (PCS). Material and methods. Articles from the following sources: PubMed, Hinari, Google Scholar were selected. Over 140 publications related to this topic were reviewed. Current publications from 2012-2023 were included. Results. The main target for SARS-CoV-2 are the cells that have ACE-2 receptors on their surface. During COVID-19, at the molecular level, pathological hyperactivation of the renin-angiotensin-aldosterone system occurs - leading to activation of the sympathetic nervous system, affecting the immune response. Additionally, there is an active expression of cytokine, chemokine and immune cell genes. All mentioned-above induces a cytokine cascade, leading to further activation of the sympathetic nervous system. There is a reciprocal vegetative-immune potentiation effect, which leads to a long-term inflammatory process in the human body, even after the complete release of SARS-CoV-2, parallel leading to exhaustion of the parasympathetic nervous system. The vegetative component explains the heterogeneity of the clinical symptoms in PCS, especially chronic fatigue, insomnia, panic attacks, depression etc. The immune component of the post-COVID syndrome can be proven by using RNA sequencing to determine the change of the transcriptome after COVID-19 or by detecting biomarkers such as CRP, IL-6 and TNF-alpha over a long period of time. Conclusion. Understanding the molecular and pathophysiological mechanisms of post-COVID syndrome is crucial for accurate diagnosis and effective treatment of affected patients

A spectroscopic and semiempirical quantum chemical study of copper (II) phthalocyaninate

Copper(II) phthalocyaninate (CuPc) was studied using both the PM3 and PM7 semiempirical molecular orbital methods, and the results were compared with its XRD, FTIR and Raman experimental properties

Hydroxyapatite coatings on TI substrates by simultaneous precipitation and electrodeposition

This paper presents the results obtained by analyzing hydroxyapatite (HA) coatings electrodeposited onto titanium plates. Instead of using a solution containing both calcium and phosphorus ions, the present approach starts with just one precursor in the electrolysis cell, and the other precursor is being added while an electrochemical potential of -1500 mV is simultaneously applied. By alternating the order of precursor addition, the Ti substrate surface was modified and the differences were evidenced using XRD, SEM, Raman and AFM. For all samples, needle-like crystals of HA grouped as hemispheres on the substrate surface. There is no significant difference, regarding morphology and hemisphere size, between the samples prepared at 1h deposition time, regardless of the precursor addition order; by contrast, the sample deposited for 4h presented a higher density

TEM, EDX and raman study of nickel oxide micro- and nanophases obtained by thermal decomposition of an organometallic precursor

Nickel(II) polyoxalate was thermally decomposed to nickel oxide in both oxidative and inert atmospheres and the products were investigated using TEM-EDX and Raman spectroscopy. The resulting micro- and nanoparticles were compared regarding their size, morphology and composition. In dynamic aerobic conditions, the product obtained at 1000 °C shows better crystallinity and presents more well defined shapes than the one obtained at 400 °C. The 1000 °C product obtained in argon is a mixture of NiO and metallic Ni

Luminescence Properties and Judd–Ofelt Analysis of Various ErF3 Concentration-Doped BaF2 Crystals

The influence of erbium ion concentration on the optical properties of BaF2:ErF3 crystals was investigated. Four ErF3 concentration (0.05, 0.08, 0.15 and 0.5 mol% ErF3)-doped BaF2 crystals were obtained using the Bridgman technique. Room temperature optical absorption in the 250–850 nm spectral range was measured, and the photoluminescence (PL) and decay times were also investigated. The Judd–Ofelt (JO) approximation was used, taking into account four absorption peaks (at 377, 519, 653 and 802 nm). The JO intensity parameters, Ωt (t = 2, 4, 6), were calculated. The influence of the ErF3 concentration on the JO parameters, branching ratio, radiative transition probability and radiative lifetime were studied. The obtained results were compared with measured values and with those reported in the literature. Under excitation at 380 nm, the well-known green (539 nm) and red (668 nm) emissions were obtained. The calculated and experimental radiative lifetimes were in millisecond range for green and red emissions. The intensity of the PL spectra varied with the Er3+ ion concentration. The emission intensity increased linearly or exponentially, depending on the ErF3 concentration. Under excitation at 290 nm, separate to the green and red emissions, a new UV emission band (at 321 nm) was obtained. Other research has not reported the UV emission or the influence of ErF3 concentration on emission behavior