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61.
Maria Elena Zarif Saa Alexandra Yehia Bogdan Bi Veronica Stulu Sorin Vizireanu Gheorghe Dinescu Alina Maria Holban Florica Marinescu Ecaterina Andronescu Alexandru Mihai Grumezescu Alexandra Ctlina Bîrc Alexandru Titus Farcaiu 《International journal of molecular sciences》2021,22(23)
Despite the technological progress of the last decade, dental caries is still the most frequent oral health threat in children and adults alike. Such a condition has multiple triggers and is caused mainly by enamel degradation under the acidic attack of microbial cells, which compose the biofilm of the dental plaque. The biofilm of the dental plaque is a multispecific microbial consortium that periodically develops on mammalian teeth. It can be partially removed through mechanical forces by individual brushing or in specialized oral care facilities. Inhibition of microbial attachment and biofilm formation, as well as methods to strengthen dental enamel to microbial attack, represent the key factors in caries prevention. The purpose of this study was to elaborate a cold plasma-based method in order to modulate microbial attachment and biofilm formation and to improve the retention of fluoride (F−) in an enamel-like hydroxyapatite (HAP) model sample. Our results showed improved F retention in the HAP model, which correlated with an increased antimicrobial and antibiofilm effect. The obtained cold plasma with a dual effect exhibited through biofilm modulation and enamel strengthening through fluoridation is intended for dental application, such as preventing and treating dental caries and enamel deterioration. 相似文献
62.
The problem of regulating an uncertain and/or time-varying linear discrete-time system with state and control constraints to the origin is addressed. It is shown that feasibility and a robustly asymptotically stable closed loop can be achieved using an interpolation technique. The design method can be seen as an alternative to optimization-based control schemes such as Robust Model Predictive Control. Especially for problems requiring complex calculations to find the optimal solution, the present method can provide a straightforward suboptimal solution. A simulation demonstrates the performance of this class of constrained controllers. 相似文献
63.
Ki-Heung Park Sorin Cristoloveanu Maryline Bawedin Youngho Bae Kyoung-Il Na Jong-Ho Lee 《Solid-state electronics》2011,59(1):39-43
We propose a double-gate (DG) 1T-DRAM cell combining SONOS type storage node on the back-gate (control-gate) for nonvolatile memory function. The cell sensing margin and retention time characteristics were systematically examined in terms of control-gate voltage (Vcg) and nonvolatile memory (NVM) function. The additional NVM function is achieved by Fowler-Nordheim (FN) tunneling electron injection into the nitride storage node. The injected electrons induce a permanent hole accumulation layer in silicon body which improves the sensing margin and retention time characteristics. To demonstrate the effect of stored electrons in the nitride layer, experimental data are provided using 0.6 μm devices fabricated on SOI wafers. 相似文献
64.
Baiyan Dong Sorin Manolache Eileen B. Somers Amy C. Lee Wong Ferencz S. Denes 《应用聚合物科学杂志》2005,97(2):485-497
Polyethylene glycol (PEG) structures were deposited onto stainless steel (SS) surfaces by spin coating and argon radio frequency (RF)‐plasma mediated crosslinking. Electron spectroscopy for chemical analysis (ESCA) and attenuated total reflectance Fourier transform infrared spectroscopy (ATR‐FTIR) indicated the presence of CH2 CH2 O structure and C C C linkage, as a result of the plasma crosslinking, on PEG‐modified SS surfaces. Scanning electron microscopy (SEM) indicated complete deposition, and water contact angle analysis revealed higher hydrophilicity on PEG‐modified surfaces compared to unmodified SS surfaces. Surface morphology and roughness analysis by atomic force microscopy (AFM) revealed smoother SS surfaces after PEG modification. The evaluation of antifouling ability of the PEG‐modified SS surfaces was carried out. Compared to the unmodified SS, PEG‐modified surfaces showed about 81–96% decrease in Listeria monocytogenes attachment and biofilm formation (p < 0.05). This cold plasma mediated PEG crosslinking provided a promising technique to reduce bacterial contamination on surfaces encountered in food‐processing environments. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 485–497, 2005 相似文献
65.
66.
Florica Adriana Nicolescu Valentin Victor Jerca Dumitru Mircea Vuluga Dan Sorin Vasilescu 《Polymer Bulletin》2010,65(9):905-916
New side-chain poly(methacrylate)s with azo moieties were prepared by free radical copolymerization, starting from methyl
methacrylate (MMA) and some original azo-monomers. The chromophore content was evaluated from 1H-NMR spectroscopy and elemental analyses; all structures exhibited a high content of azobenzene units. UV–Vis measurements
have also supported this fact. Reactivity ratios for the methacrylate systems and their corresponding Q–e values were calculated based on several initial feed compositions (MMA and the newly synthesized azo-monomers) using an integral
method with its appropriate software. The polymers were also characterized by FTIR, SEC and DSC-TGA techniques. The coloured
poly(methacrylate)s exhibited glass transition temperatures between 141 and 168 °C and thermal stabilities up to 306 °C. 相似文献
67.
This study reports the synthesis and characterization of two urethane dimethacrylates containing poly(ethylene oxide) or poly(propylene oxide) segment and cinnamate pendant moieties to be formulated in dental resin composites. 1H NMR, 13C NMR, and Fourier transform infrared spectroscopies, gel permeation chromatography, electrospray ionization‐mass spectroscopy, and thermogravimetric measurements confirmed their structure, whereas the photopolymerization evolution of oligodimethacrylates relating to a low–molecular‐weight dicinnamate methacrylate under ultraviolet irradiation was investigated by photo‐differential scanning calorimeter, monitoring the degree of conversion (DC) and polymerization rate. The photopolymerization results reveal that the investigated derivatives display a good photoreactivity (DC: ~ 70%) during the formation of crosslinked polymers, the DC depending especially on the sample viscosity. The polymerization shrinkage for several mixtures including the urethane oligocinnamates (20 wt %) and diglycidyl methacrylate of bisphenol A/triethyleneglycol dimethacrylate system in the absence of filler was determined, the obtained values being in the range of 6.1–8.2 vol %. For few cured specimens incorporating quartz filler (75 wt %), water sorption/solubility, contact angle, and mechanical parameters were measured to establish if such monomers could be of interest in dentistry. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013 相似文献
68.
69.
Flame retardant cellulosic materials have been produced using a silicon dioxide (SiO2) network coating. SiO2 network armor was prepared through hydrolysis and condensation of the precursor tetraethyl orthosilicate (TEOS), prior coating the substrates, and was cross linked on the surface of the substrates using atmospheric pressure plasma (APP) technique. Because of protection effects of the SiO2 network armor, the cellulosic based fibers exhibit enhanced thermal properties (characterized by TGA and DSC) and improved flame retardant (proven by ASTM D1230‐99). Furthermore, the surface analysis (XPS and SEM) confirmed the presence of the SiO2 network attached to the substrates even after intense ultrasound washes. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 相似文献
70.
Cotar AI Chifiriuc MC Dinu S Bucur M Iordache C Banu O Dracea O Larion C Lazar V 《International journal of molecular sciences》2010,11(12):5273-5291
Staphylococcus (S.) aureus and Pseudomonas (Ps.) aeruginosa are two of the most frequently opportunistic pathogens isolated in nosocomial infections, responsible for severe infections in immunocompromised hosts. The frequent emergence of antibiotic-resistant S. aureus and Ps. aeruginosa strains has determined the development of new strategies in order to elucidate the different mechanisms used by these bacteria at different stages of the infectious process, providing the scientists with new procedures for preventing, or at least improving, the control of S. aureus and Ps. aeruginosa infections. The purpose of this study was to characterize the molecular markers of virulence in S. aureus and Ps. aeruginosa strains isolated from different clinical specimens. We used multiplex and uniplex PCR assays to detect the genes encoding different cell-wall associated and extracellular virulence factors, in order to evaluate potential associations between the presence of putative virulence genes and the outcome of infections caused by these bacteria. Our results demonstrate that all the studied S. aureus and Ps. aeruginosa strains synthesize the majority of the investigated virulence determinants, probably responsible for different types of infections. 相似文献