Influența exercitată de Led-uri și tuburile fluorescente, de diferite culori, asupra proceselor regenerative și a morfogenezei la culturile in vitro de Rebutia heliosa

The paper traces how the light source and light color influence the regenerative processes and morphogenesis in vitro cultures of Rebutia heliosa. To establish the vitroculture of R. heliosa, some explants from young plants, either buds or rounds cut from young stems and cross-sectioned were considered. The culture medium consisted of: macroelements and Fe EDTA Murashige-Skoog (1962), microelements Heller (1953), a mineral mixture to which the following vitamins were added: pyridoxine HCl, thiamine HCl and nicotinic acid (each 1 mg/l, each), m-inositol – 100 mg/l, sucrose – 20 g/l and agar-agar 7 g/l, without growth phytoregulators.The variable element was the lighting source. Fluorescent tubes and LEDs (monochrome but differently coloured) have been used: blue (λ = 470 nm), yellow (λ = 580 nm), green (λ = 540 nm), red (λ = 670 nm) as well as LED`s emitting white light (λ = 510 nm) at a luminous intensity of 1000 lux. The evolution of R. heliosa vitro cultures was monitored for 90 days and analyzed their reaction variability. Based on the comparative study, the following can be stated: the light of fluorescent tubes is more suitable for the morphogenesis of R. heliosa vitroplants, but the processes of regeneration and organogenesis are directly influenced by the source and color of light influenced, thus rhizogenesis and caulogenesis is favored by the presence of green and red light emitted by LEDs, while the white and yellow light of fluorescent tubes favors the caulogenesis and callusogenesis processes.Lucrarea urmărește modul în care sursa de iluminare și culoarea luminii influențează procesele regenerative și morfogeneza în vitroculturile de R. heliosa. Pentru a înființa vitrocultura de R. heliosa am prelevat explante de la plante t inere, fie mugurași, fie rondele decupate din tulpinile tinere și secţionate transversal. Mediul de cultură utilizat de noi a constat din: macroe-lemente şi Fe EDTA Murashige-Skoog (1962), microelemente Heller (1953), amestec mineral la care au fost adăugate vitaminele: piridoxină HCl, tiamină HCl şi acid nicotinic (câte 1 mg/l, fiecare), m-inozitol – 100 mg/l, zaharoză – 20 g/l şi agar-agar 7 g/l, fără fitoregulatori de creștere. Variabila este reprezentată de sursa de iluminare, tuburi fluorescente și LED-uri (monocrome și diferit colorate): albastru (λ = 470nm), galben (λ = 580nm), verde (λ = 540nm), roșu (λ = 670nm) și LED-uri care emit lumină albă (λ = 510nm) la o intensitate luminoasă de 1000 lux. Am urmărit timp de 90 de zile evoluţia vitroculturilor de R. heliosa și am analizat variabilitatea de reacţie a acestora iar pe baza studiului comparativ putem afirma următoarele: lumina tuburilor fluorecente este mai potrivită pentru morfogeneza vitroplantulelor de R. heliosa, dar procesele de regenerare și organogeză sunt influențate în mod direct de sursa și culoarea luminii, astfel rizogeneza și caulogeneza este favorizează de prezența luminii verde și roșie emisă de LED-uri în timp ce lumina albă și galbenă a tuburilor fluorescente avantajează procesele de caulogeneză și calusogeneză

MORPHOLOGICAL CHANGES DURING GERMINATION AND GROWTH OF RAPESEED SAMPLES (Brassica napus) EXPOSED TO NON-IONIZING RADIATION

The UV-A radiation acts on cellular constituents indirectly through oxidative mechanisms involving the radicals’ formation. These species have a relatively short lifespan, but are highly reactive, reacts with most cellular constituents: nucleic acids, proteins, lipids, polysaccharides. The rapeseed samples provided by Agricultural Research Center Secuieni, Neamţ (Romania) were irradiated with a wide band source (UV-B, UV-A, visible) with different non-radiation doses, equivalent to several hours of sun exposure. The exposure to UV radiation determines changes in the metabolism, within the growth and development processes, having positive or negative influences on plant health and vitality. The purpose of this study is to analyze different rapeseed samples in order to identify the differences according to non-radiation effect. Regarding the growth and development of height stems it has been observed that roots length and stem height of rape samples are highest at irradiation time around 280 minutes

WHEAT FLOUR HUMIDITY VARIATION WITH UV-VIS RADIATION DOSE REVEALED BY SPECTRAL AND CHEMOMETRIC STUDIES

The cells’ exposure to UV radiation induces mutations of the cellular components by its action on DNA, protein synthesis and enzymatic activities. Different varieties of wheat flour were treated with UV-B, UV-A, Vis radiation and compared with untreated samples. The IR spectra for these components were recorded with a Bruker FTIR spectrophotometer using an ATR method, at 4 cm-1 resolution. The paper proposes a comparative study of unmaturing flour behavior under UV-Vis and natural radiations in order to observe the physico-chemical changing by FTIR spectroscopy. At small doses of irradiation (up to 2 h) the humidity of the samples decreases and then it significantly increases, most pronounced in Gruia’s case where the humidity is reaching 74.4% of the initial value. Middle infrared spectral studies reveal an inverse weak linear correlation between Amide I region (1650 cm-1) (R-squared value: -0.3168) and an inverse medium linear correlation assigned to area alcohol O-H band at 3290 cm-1 (R-squared value: -0.6064) with the irradiation dose variables. Strong direct linear correlations confirmed by R-squared value: 0.7835 are found between alcohol O-H band at 3290 cm-1 and humidity percentage parameter

Degradation of keratin substrates by keratinolytic fungi

Background: The hydrolysis of keratin wastes by microorganisms is considered a biotechnological alternative for recycling and valorization through keratinolytic microorganisms. Despite their resistant structure, keratin wastes can be efficiently degraded by various microorganisms through the secretion of keratinases, which are promising enzymes for several applications, including detergents, fertilizers, and leather and textile industry. In an attempt to isolate keratinolytic microorganisms that can reach commercial exploitation as keratinase producers, the current work assesses the dynamics of keratin biodegradation by several keratinolytic fungal strains isolated from soil. The activity of fungal strains to degrade keratin substrates was evaluated by SEM, FTRIR-ATR spectra and TGA analysis. Results: SEM observations offered relevant information on interactions between microorganism and structural elements of hair strands. FTIR spectra of the bands at 1035–1075 cm-1 assigned to sulfoxide bond appeared because of S–S bond breaking, which demonstrated the initiation of keratin biodegradation. According to TGA, in the second zone of thermal denaturation, where keratin degradation occurs, the highest weight loss of 71.10% was obtained for sample incubated with Fusarium sp. 1A. Conclusions: Among the tested strains, Fusarium sp. 1A was the most active organism in the degradation process with the strongest denaturation of polypeptide chains. Because keratinolytic microorganisms and their enzymes keratinases represent a subject of scientific and economic interest because of their capability to hydrolyze keratin, Fusarium sp. 1A was selected for further studies

Changes in Epidemiology and Antibiotic Prescription of Influenza: Before and after the Emergence of COVID-19

Background: The appearance of COVID-19 had a major impact on healthcare and the epidemiology of other diseases. Following the cessation of non-pharmacologic interventions destined to limit the spread of COVID-19, influenza reemerged. The aim of this study was to compare the pre-pandemic influenza seasons with the influenza seasons after the emergence of the COVID-19 pandemic, and to identify differences in terms of clinical characteristics, risk factors, complications, outcomes, and antiviral and antibiotic treatments. Methods: We conducted a retrospective cohort study from the Teaching Hospital of Infectious Diseases database in Cluj-Napoca, Romania. We analyzed four pre-pandemic seasons and the seasons after the onset of COVID-19. We included adult patients hospitalized with confirmed influenza between October 2016 and August 2023. Variables such as age, sex, duration of hospitalization, severity, clinical manifestations, comorbidities, and Charlson comorbidity index were assessed. Results: A total of 941 patients were included in the analysis. The percentage of severe influenza was similar in both groups, but mortality from influenza was significantly lower after 2022. Virtually all patients were prescribed antivirals; antibiotic prescriptions decreased in the post-COVID-19 influenza seasons. Conclusion: The present study suggests that influenza seasons after 2022 had lower mortality and attenuated clinical presentation