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Ridge frequency is an important parameter in fingerprint image processing and feature extraction. However, ridge frequency estimation is a difficult task in noisy fingerprint images. A simple and accurate method for the computation of fingerprint ridge frequency using the Fourier spectrum is proposed. The results of the experiments conducted on a collection of fingerprints as well as a quantitative method for performance evaluation based on a Gabor filter-bank are presented. The proposed method is robust with respect to noise and reliable frequency images are obtained.

The service life of various mechanical elements subjected to contact load can be extended by means of a hard coating protecting the substrate. The design of competent coated systems relies on the assessment of stresses, induced in a layered body under contact load. The fast Fourier transform has been widely used in the computation of displacements and stresses arising in homogenous bodies and the extension of this technique to layered solids is enticing considering that the Green's functions, describing the response of layered solids to load, are only available in the frequency domain. The newly proposed technique for displacement calculation is coupled with the Conjugate Gradient Method to assess the contact area and the pressure distribution from a purely elastic contact model, while imposing an additional pressure cut-off limit that assures realistic prediction of contact spots in rough contact simulation. The newly advanced computer code is benchmarked against existing results for the spherical indentation of a coated flat surface, derived by a different method, and then applied to the simulation of the contact process involving a deterministic roughness sample. [ABSTRACT FROM AUTHOR]

An algorithm for simulation of linear viscoelastic contacts advanced in a companion paper is extended and employed to study the effect of the loading rate and of the loading frequency in the spherical indentation of a Zener half-space. The newly proposed extended model can tackle displacement-driven contact scenarios, as well as the computation of the post-unloading displacement. A triangular loading profile is imposed to study the effect of the loading rate on contact parameters. The viscoelastic contact performance under harmonic load is investigated for an imposed spectrum of excitation frequencies. As the proposed algorithm can readily handle complex constitutive models of linear viscoelasticity and arbitrary loading programs, the simulation of the viscoelastic contact process is achieved with greater accuracy compared to other existing computational methods. [ABSTRACT FROM AUTHOR]

This study presents the phytosynthesis of silver-based nanoparticles using tomato flower waste extracts for the first time in the literature. The determination of total polyphenolic and flavonoid contents in the extracts showed high gallic acid equivalents (6436-8802 mg GAE/kg dm) and high quercetin equivalents (378-633 mg QE/kg dm), respectively, dependent on the extraction method. By the Ultra Performance Liquid Chromatography technique, 14 polyphenolic compounds were identified and quantified in the tomato flower waste extracts. The abundant phenolic compounds were caffeic acid (36,902-32,217 mg/kg) and chlorogenic acid (1640-1728 mg/kg), and the abundant flavonoid compounds were catechin (292-251 mg/kg) and luteolin (246-108 mg/kg). Transmission electron microscopy of the nanoparticles revealed a particle size range of 14-40 nm. Fourier Transform infrared spectroscopy and X-ray diffraction studies confirmed the phytosynthesis of the silver/silver oxide nanoparticles. These findings hold significant results for the antibacterial and antitumoral potential applications of the obtained nanoparticles, opening new areas for research and development and inspiring further exploration. The impact of this research on the field of metallic nanoparticle phytosynthesis is substantial, as it introduces a novel approach and could lead to significant advancements in the field.

The aims of the present study were to evaluate for the first time the chemical composition and antioxidant, antibacterial, antifungal and antiproliferative potentials of the Romanian George 90 lavender species, as well as parental species, L. angustifolia and L. latifolia . The L. angustifolia , L. latifolia and George 90 essential oils were analyzed by GC-MS/MS and the L. angustifolia , L. latifolia and George 90 hydroalcoholic extracts were analyzed by HPLC-DAD. The antioxidant, antibacterial, antifungal and antiproliferative assays revealed that all the investigated species showed significant activities. The results highlighted the chemical composition and the promising biological potentials of the L. angustifolia , L. latifolia and George 90 lavender species, validating their ethnomedicinal value, which offers potential applications as natural drugs.

Helicobacter pylori causes gastritis, peptic ulcers and gastric cancer and affects more than half of the world's population. Although this infection can have serious consequences, no novel cure or remedy have been discovered, the present therapy still relies on a variety of known antibiotics and anti-secretory agents. In the present study, the potential effect of combinations between methanolic extracts of four Algerian medicinal plants, garlic ( Allium sativum ), red onion ( Allium cepa ), cumin ( Cuminum cyminum L.) and fenugreek ( T. foenum-graecum L.), with different strains of lactic acid bacteria against H. pylori , was investigated. Similarly, the in vivo antibacterial effect of fenugreek extract combined with Bifidobacterium breve on H. pylori colonization potential to confirm the enhanced effect of the mixture was explored. Helicobacter pylori was inhibited by all combined mixtures of extracts and probiotics with varying results. The highest anti- H. pylori activities were found in fenugreek/ B. breve , cumin/ B. breve , garlic/ B. breve and onion/ B. breve combinations with inhibition diameters of 29, 26, 23 and 25 mm, respectively. Preliminary studies on the effect of probiotics against H. pylori revealed that the inhibition was due to lactic acid and bacteriocins and it was also related to the presence of phenolic compounds in the studied plants, such as gallic acid, caffeic acid, quercetin and vanillic acid. Fenugreek extract was found to inhibit the growth of H. pylori in a concentration-dependent manner. When H. pylori -infected rats were administered B. breve , the infection rate of H. pylori was significantly reduced, while the combination of B. breve and fenugreek extract effectively inhibited H. pylori . In addition, the B. breve and fenugreek extract mixture significantly reduced gastritis in H. pylori -infected rats. These results suggest that this complex mixture may be an alternative to treating diseases caused by H. pylori infection.

The present work describes, for the first time in the literature, the phytosynthesis of silver nanoparticles using Leonurus cardiaca L. extracts. The influence of the extraction method (classical temperature extraction and microwave extraction), as well as of the extract concentration on the characteristics of the nanoparticles, was studied using analytical methods, such as UV-Vis spectrometry, X-ray diffraction, dynamic light scattering, and transmission electron microscopy. Experimental data suggest that use of lower extract concentration leads to smaller dimensions nanoparticles, the same effect using the extract obtained by microwave-assisted extraction. The smallest recorded crystallite sizes (by X-ray diffraction) were under 3 nm. The antioxidant properties (determined by the DPPH assay) and the antimicrobial potential (determined against Gram-negative and Gram-positive strains) are enhanced by the phytosynthesis process (as demonstrated by the comparison of the nanoparticles' properties with the parent extracts). The present work could also represent an important step in obtaining nanoparticles with enhanced properties and controlled morphologies, but also offers information on the phytosynthesis of metallic nanoparticles using low extract concentrations.

The duration of denture use, oral hygiene, smoking and male sex were identified as risk factors for oral mucosal lesions. As it is well known, all the oral mucosal lesions associated with risk factors have an important degree of malignity. Chronic mechanical irritation can be another cause of oral cancer and it is produced by the constant action of a deleterious agent from the oral cavity. Autophagy represents a complex evolutionary conserved catabolic process in which cells self-digest intracellular organelles in order to regulate their normal turnover and remove the damaged ones with compromised function to further maintain homeostasis. Autophagy is modulated by mTOR kinase and indirectly by PI3K/AKT survival pathway. Due to its dual capacity to either induce cell death or promote cell survival, important evidence pointed that autophagy has a two-faced role in response to chemotherapy in cancer. In conclusion, understanding how to overcome cytoprotective autophagy and how to take advantage of autophagic cell death is critical in order to enhance the cancer cells sensitivity to particular therapeutic agents.