Search results for "Statics"
showing 10 items of 141 documents
Generalized synthesis of periodic surfactant/inorganic composite materials
1994
THE recent synthesis of silica-based mesoporous materials1,2 by the cooperative assembly of periodic inorganic and surfactant-based structures has attracted great interest because it extends the range of molecular-sieve materials into the very-large-pore regime. If the synthetic approach can be generalized to transition-metal oxide mesostructures, the resulting nanocomposite materials might find applications in electrochromic or solid-electrolyte devices3,4, as high-surface-area redox catalysts5 and as substrates for biochemical separations. We have proposed recently6 that the matching of charge density at the surfactant/inorganic interfaces governs the assembly process; such co-organizatio…
2020
Biomolecules, and particularly proteins, bind on nanoparticle (NP) surfaces to form the so-called protein corona. It is accepted that the corona drives the biological distribution and toxicity of NPs. Here, the corona composition and structure were studied using silica nanoparticles (SiNPs) of different sizes interacting with soluble yeast protein extracts. Adsorption isotherms showed that the amount of adsorbed proteins varied greatly upon NP size with large NPs having more adsorbed proteins per surface unit. The protein corona composition was studied using a large-scale label-free proteomic approach, combined with statistical and regression analyses. Most of the proteins adsorbed on the N…
Cytotoxicity of a new hemostatic agent on human pulp fibroblasts in vitro
2011
Objective: The objective of this study was to evaluate the cytotoxicity of the plant extract ankaferd blood stopper (ABS) in vitro. Study Design: ABS was eluted with fresh Dulbecco's Modified Eagle's Medium (DMEM) without serum for 72 h, at 37°C. The cells treated with various dilutions of ABS were seeded into 96-well microplate at 10 4 /well in triplicates. Cells without treatment served as a control group. The number of viable cells after 48 h incubation was determined by a modified 3-(4, 5-dimethyl-thiazol-2-yl)-2, 5-diphenyl-tetrazolium bromide (MTT) assay. The relative viability of pulp cells was expressed as color intensity of the number in the experimental wells relative to that of t…
Electrostatic phenomena in ion exchange membranes
1971
Abstract Specific and transport properties of a cation and an anion exchange membrane in Na + and Cl - form respectively have been measured in water and dioxane water mixtures. A greater electrolyte absorption and a lesser specific conductivity and counterion transport number in solvents at higher dioxane content indicate strong electrostatic interactions between fixed groups in the membrane and counterions.
Solvability of a first order system in three-dimensional non-smooth domains
1985
summary:A system of first order partial differential equations is studied which is defined by the divergence and rotation operators in a bounded nonsmooth domain $\Omega\subset \bold R^3$. On the boundary $\delta\Omega$, the vanishing normal component is prescribed. A variational formulation is given and its solvability is investigated.
No influence of magnetic fields on cell cycle progression using conditions relevant for patients during MRI.
2003
The purpose of this study was to examine whether exposure to magnetic fields (MFs) relevant for magnetic resonance imaging (MRI) in clinical routine influences cell cycle progression in two tumor cell lines in vitro. HL60 and EA2 cells were exposed to four types of MFs: (i) static MF of 1.5 and 7.05 T, (ii) extremely low frequency magnetic gradient fields (ELFMGFs) with ± 10 mT/m and 100 Hz, as well as ± 100 mT/m and 100 Hz, (iii) pulsed high frequency MF in the radiofrequency (RF) range (63.6 MHz, 5.8 μT), and (iv) a combination of (i–iii). Exposure periods ranged from 1 to 24 h. Cell cycle distribution (G0/G1, S, and G2/M phases) was analyzed by flow cytometry. Cell cycle analysis did not…
The role of hemostatic devices in neurosurgery. A systematic review.
2021
Hemostasis represents a fundamental step in every surgical procedure. During neurosurgical procedures, proper and robust hemostasis into confined spaces can significantly reduce the odds of perioperative complications. Over the decades, multiple methods have been applied, and several medical devices have been developed to promote and guarantee proper hemostasis. This study presents a systematic review of the most used intraoperative hemostatic methods and devices in neurosurgery. Insightful research was performed on the PubMed database according to the PRISMA guidelines. This comprehensive review of scientific literature represents a synoptic panel where the most used intraoperative hemosta…
Haemostatic agents in apical surgery. A systematic review.
2015
Background Blood presence in apical surgery can prevent the correct vision of the surgical field, change the physical properties of filling materials and reduce their sealing ability. Objetive To describe which are the most effective and safest haemostatic agents to control bleeding in patients undergoing apical surgery. Material and Methods TWe carried out a systematic review, using Medline and Cochrane Library databases, of human clinical studies published in the last 10 years. Results The agents that proved more effective in bleeding control were calcium sulphate (100%) and collagen plus epinephrine (92.9%) followed by ferric sulphate (60%), gauze packing (30%) and collagen (16.7%). When…
Hemostasis in brain tumor surgery using the Aquamantys system
2014
Background: Adequate hemostasis in cranial and spinal tumor surgery is of paramount importance in neurosurgical practice. Generalized ooze bleeding from the surgical walls cavity, coming from neoplastic vessels or nervous tissue, may be problematic. Recent technical advances have dramatically reduced intraoperative complications related to blood loss. Several techniques are usually employed to control hemostasis in tumor surgery, including preoperative embolization, intraoperative hypotension, electrical coagulation, and local application of fibrin sealants or hemostatic matrix, which influence coagulation. Material/Methods: Our aim in this study was to evaluate the efficacy and the safety …