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To examine in detail the behavior of a new vortex shedding mode found in a previous investigation [Phys. Fluids 14, 3160 (2002)], a two-dimensional numerical study on the laminar incompressible flow past a rotating circular cylinder in the Reynolds number range 60≤Re≤200 and at rotational rates 0≤α≤6 was carried out. The results obtained clearly confirm the existence of the second shedding mode for the entire Reynolds number range investigated. A complete bifurcation diagram a(Re) was compiled defining both kind of shedding modes. The unsteady periodic flow in the second mode is characterized by a frequency much lower than that known for classical von Kármán vortex shedding of the first mode. The corresponding Strouhal number shows a strong dependence on the rotational velocity of the cylinder, while only a weak dependence is observed for the Reynolds number. Furthermore, the amplitudes of the fluctuating lift and drag coefficients are much larger than those characterizing classical vortex shedding behind nonrotating or slowly rotating cylinders. Additionally, negative values for the mean drag denoting thrust are found within the second shedding mode. [ABSTRACT FROM AUTHOR]

A two-dimensional numerical study on the laminar flow past a circular cylinder rotating with a constant angular velocity was carried out. The objectives were to obtain a consistent set of data for the drag and lift coefficients for a wide range of rotation rates not available in the literature and a deeper insight into the flow field and vortex development behind the cylinder. First, a wide range of Reynolds numbers (0.01 ≤ Re ≤ 45) and rotation rates (0 ≤ α ≤ 6) were considered for the steady flow regime, where α is the circumferential velocity at the cylinder surface normalized by the free-stream velocity. Furthermore, unsteady flow calculations were carried out for one characteristic Reynolds number (Re = 100) in the typical two-dimensional (2D) vortex shedding regime with α varying in the range 0 ≤ α ≤ 2. Additionally, the investigations were extended to very high rotation rates (α ≤ 12) for which no data exist in the literature. The numerical investigations were based on a finite-volume flow solver enhanced by multi-grid acceleration and the local grid refinement technique to achieve efficient computations and accurate numerical results. The predictions show that the rotation of the cylinder suppresses the vortex development in both the steady and the unsteady flow regimes and significantly changes the flow field close to the cylinder. For very low Reynolds numbers, the drag force is not affected by rotation and the lift force is a linear function of α. For higher Re in the steady flow regime, the drag force decreases with increasing rotational velocities even leading to negative values. The lift force is almost a linear function of the rotational velocity and nearly independent of Re for low rotational speeds of α < 2. However, for higher α values and larger Reynolds numbers (Re > 1), a progressive increase in the lift force is observed. A very interesting phenomenon was found in the... [ABSTRACT FROM AUTHOR]

In this article, we explicitly construct the coordinates associated with the Penrose diagram in spacetimes connected via a spacelike thin shell in the following two examples: the generalized black-to-white hole bounce with mass difference and the Schwarzschild-to-de Sitter transition. We point out the issue of the first junction condition in the Penrose diagram constructed by cutting and pasting analytically known metrics with spherical symmetry by a static spacelike thin shell. With the goal of a global conformal coordinate chart associated with the corresponding Penrose diagram without discontinuity at the thin shell, we give a procedure consisting of three conformal transformations that serve different purposes. The first two of them are used to generate a continuous coordinate patch covering the entire thin shell, and therefore, the Penrose diagram can be constructed properly by patches with overlapping. The third transformation removes any coordinate singularity reintroduced by the first two transformations at the event horizons., (© 2024. The Author(s).)

Despite the significant advances in drug development we are witnessing the inability of health systems to combat both neurodegenerative diseases and cancers, especially glioblastoma. Hence, natural products are comprehensively studied in order to provide novel therapeutic options. This study aimed to explore anti-neurodegenerative and anti-glioblastoma potential of extract of Phlomis fruticosa L. using in vitro model systems. It was found that the methanol extract of P. fruticosa was able to efficiently reduce activities of enzymes linked to neurodegenerative disease including acetylcholinesterase, butyrylcholinesterase and tyrosinase. Furthermore, P. fruticosa extract has shown excellent antioxidant potential, as evidenced by six different methods. Analysis of cytotoxic effect of P. fruticosa extract on A172 glioblastoma cell line revealed that the concentration of the extract necessary for 50 % inhibition of A172 growth (IC 50 ) was 710 μg/mL. The extract did not induce changes in proliferation and morphology of A172 glioblastoma cells. On the other side, production of ROS was increased in A172 cells treated with the extract. Observed cytotoxic effect of P. fruticosa extract might be based on increase in ROS generation upon treatment. Quantitative chemical analysis revealed the presence of twelve different polyphenols with the cis 3- O -caffeoylquinic acid being the most abundant. This study provided scientific evidence for further exploration of P. fruticosa as a promising natural anti-neurodegenerative therapeutic option., (Copyright © 2022 Stojkovic et al.)

Local anesthetic wound infiltration (WI) provides anesthesia for minor surgical procedures and improves postoperative analgesia as part of multimodal analgesia after general or regional anesthesia. Although pre-incisional block is preferable, in practice WI is usually done at the end of surgery. WI performed as a continuous modality reduces analgesics, prolongs the duration of analgesia, and enhances the patient's mobilization in some cases. WI benefits are documented in open abdominal surgeries (Caesarean section, colorectal surgery, abdominal hysterectomy, herniorrhaphy), laparoscopic cholecystectomy, oncological breast surgeries, laminectomy, hallux valgus surgery, and radical prostatectomy. Surgical site infiltration requires knowledge of anatomy and the pain origin for a procedure, systematic extensive infiltration of local anesthetic in various tissue planes under direct visualization before wound closure or subcutaneously along the incision. Because the incidence of local anesthetic systemic toxicity is 11% after subcutaneous WI, appropriate local anesthetic dosing is crucial. The risk of wound infection is related to the infection incidence after each particular surgery. For WI to fully meet patient and physician expectations, mastery of the technique, patient education, appropriate local anesthetic dosing and management of the surgical wound with "aseptic, non-touch" technique are needed.

Due to limited arsenal of systemically available antifungal agents, infections caused by Candida albicans are difficult to treat and the emergence of drug-resistant strains present a major challenge to the clinicians worldwide. Hence further exploration of potential novel and effective antifungal drugs is required. In this study we have explored the potential of a flavonoid, astragalin, in controlling the growth of C. albicans, in both planktonic and biofilm forms by microdilution method; and in regulating the morphological switch between yeast and hyphal growth. Astragalin ability to interfere with membrane integrity, ergosterol synthesis and its role in the regulation of genes encoding for efflux pumps has been addressed. In our study, astragalin treatment produced good antimicrobial and significant antibiofilm activity. Anticandidal activity of astragalin was not related to ERG11 downregulation, neither to direct binding to CYP51 enzyme nor was linked to membrane ergosterol assembly. Instead, astragalin treatment resulted in reduced expression of CDR1 and also affected cell membrane integrity without causing cytotoxic effect on human gingival fibroblast cells. Considering that astragalin-mediated decreased expression of efflux pumps increases the concentration of antifungal drug inside the fungal cells, a combinatorial treatment with this agent could be explored as a novel therapeutic option for candidiasis., (Copyright © 2020 Ivanov et al.)

Aim: Newly synthesized platinum(IV) complexes with ethylenediamine-N,N'-diacetate ligands (EDDA-type) (butyl-Pt and pentyl-Pt) were investigated against two cancer (A549 lung, and HTB 140 melanoma) and one non-cancerous (MRC-5 embryonic lung fibroblast) human cell lines., Materials and Methods: The effects of these agents were compared with those of cisplatin after 6-, 24- and 48-h treatment. Sulforhodamine-B (SRB) assay was performed to estimate the cytotoxic effect, while the inhibitory effect on cell proliferation was measured using 5-bromo-2,-deoxyuridine (BrdU) incorporation assay. Cell cycle analysis was performed by flow cytometry. Type of cell death induced by these agents was determined by electrophoretic analysis of DNA, flow cytometry and by western blot analysis of proteins involved in induction of apoptosis. The effects of gamma irradiation, alone and in combination with platinum-based compounds, were examined by clonogenic and SRB assays., Results: All examined platinum-based compounds had inhibitory and antiproliferative effects on A549 cells, but not on HTB140 and MRC-5 cells. Butyl-Pt, pentyl-Pt and cisplatin arrested the cell cycle in the S-phase and induced apoptotic cell death via regulation of expression of B-cell lymphoma 2 (BCL2) and BCL2-associated X (BAX) proteins. Platinum-based compounds increased the sensitivity of A549 cells to gamma irradiation. Butyl-Pt and pentyl-Pt showed better antitumour effects against A549 cells than did cisplatin, by interfering in cell proliferation and the cell cycle, and by triggering apoptosis., Conclusion: The effects of gamma irradiation on tumour cells may be amplified by pre-treatment of cells with platinum-based compounds., (Copyright© 2020, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

The essential oil of Thymus algeriensis was analyzed as a potential preservative in soft cheese. We developed a novel method to test the preserving properties of essential oil in soft cheese. Contamination incidence of Penicillium aurantiogriseum was absent after 30 d of storage at 4°C with 25 µL of essential oil added. The antimicrobial activity was tested against 8 bacteria and 8 fungi. Thymus algeriensis oil showed inhibitory activity against tested bacteria at 0.03 to 0.09 mg/mL, and bactericidal activity was achieved at 0.05 to 0.15 mg/mL. For antifungal activity, minimum inhibitory concentrations ranged between 0.01 and 0.04 mg/mL and minimum fungicidal concentrations between 0.01 and 0.04 mg/mL. Furthermore, the oil was also screened for antiradical activity using the 1,1-diphenyl-2-picrylhydrazyl assay. The results showed that the oil was active and achieved half-maximal inhibitory activity at 0.132 mg/mL. We used gas chromatography, gas chromatography-mass spectrometry, and nuclear magnetic resonance spectrometry to investigate the volatile compounds from the oil. Carvacrol was identified as the main compound in the oil, represented by 80.9% of the total constituents, followed by p-cymene (7.7%)., (Copyright © 2018 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.)

Bioactive potential of apigenin derivative apigenin-7- O -glucoside related to its antifungal activity on Candida spp. and cytotoxic effect on colon cancer cells was studied and compared with bioactive potential of apigenin. Antifungal activity was tested on 14 different isolates of Candida spp. using membrane permeability assay, measuring inhibition of reactive oxidative species and inhibition of CYP51 C. albicans enzyme. Cytotoxic potential of apigenin-7- O -glucoside was tested on colon cancer HCT116 cells by measuring cell viability, apoptosis rate and apoptosis- and colon cancer-related gene expression. Obtained results indicated considerable antifungal activity of apigenin-7- O -glucoside towards all Candida isolates. Breakdown of C. albicans plasma membrane was achieved upon treatment with apigenin-7- O -glucoside for shorter period of time then with apigenin. Reduction of intra- and extracellular reactive oxidative species was achieved with minimum inhibitory concentrations of both compounds, suggesting that reactive oxidative species inhibition could be a mechanism of antifungal action. None of the compounds exhibited binding affinity to C. albicans CYP51 protein. Besides, apigenin-7- O -glucoside was more effective compared to apigenin in reduction of cell's viability and induction of cell death of HCT116 cells. Treatment with both compounds resulted in chromatin condensation, apoptotic bodies formation and apoptotic genes expression in HCT116 cells, but the apigenin-7- O -glucoside required a lower concentration to achieve the same effect. Compounds apigenin-7- O -glucoside and apigenin displayed prominent antifungal potential and cytotoxic effect on HCT116 cells. However, our results showed that apigenin-7- O -glucoside has more potent activity compared to apigenin in all assays that we used.