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Chen, Wenwen [Verfasser], and Joachim [Akademischer Betreuer] Spatz. "Anti-Reflective and Anti-Bacterial Properties of Biomimetic Nanostructures / Wenwen Chen ; Betreuer: Joachim Spatz." Heidelberg : Universitätsbibliothek Heidelberg, 2016. http://d-nb.info/1180611349/34.
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Chen, Wenwen [Verfasser], and Joachim P. [Akademischer Betreuer] Spatz. "Anti-Reflective and Anti-Bacterial Properties of Biomimetic Nanostructures / Wenwen Chen ; Betreuer: Joachim Spatz." Heidelberg : Universitätsbibliothek Heidelberg, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:16-heidok-205577.
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Brandt, Paul Dieter. "Shear bond strength, microleakage and anti-bacterial properties of self-etching bonding systems." Diss., Pretoria : [s.n.], 2009. http://upetd.up.ac.za/thesis/available/etd-02182010-110040/.
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Ray, Priyanka. "Calixarenes and Nanoparticles : Synthesis, Properties and Applications." Thesis, Paris 11, 2013. http://www.theses.fr/2013PA112131.
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Le travail présenté dans ce manuscrit inclut la synthèse organique des différents types de calixarènes, l'étude de leurs propriétés optiques, des simulations théoriques pour déterminer leurs conformations favorables et leurs utilisations pour stabiliser des nanoparticules. Des nanoparticules d’argent, d’or, de platine et des nanoparticules bimétalliques (Ag-Au) ont été synthétisées en utilisant par réduction radiolytique ainsi que la synthèse la photochimique. Ces nanoparticules sont stabilisées en utilisant des calixarènes et divers polymères. Les nanomatériaux ont été caractérisés par spectroscopie d’absorption UV-Visible et spectroscopie de fluorescence et par des observations en microscopie électronique en transmission. Comme les nanoparticules métalliques sont connues pour leurs applications dans divers domaines, des propriétés antibactériennes de nanoparticules d'argent et des propriétés électrocatalytiques des nanoparticules d'or ont été testéesThe work presented in this manuscript includes the organic synthesis of different types of calixarenes, the study of their optical properties, computational studies for determination of their favourable conformations and their use in the stabilisation of nanoparticles. Silver, gold, platinum and bimetallic (Ag-Au) nanoparticles were synthesised using radiolytic reduction as well as photochemical method. These nanoparticles were stabilised by calixarenes and also other ligands which included several polymers. The nanomaterials were characterised using UV-Visible absorption and fluorescence spectroscopy and transmission electron microscopy (TEM) measurements. As metal nanoparticles are known for their applications in various fields, the antibacterial properties of silver nanoparticles and the electrocatalytic properties of gold nanoparticles were tested
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Buzby, Scott Edward. "The effect of doping titanium dioxide nanoparticles on phase transformation, photocatalytic activity and anti-bacterial properties." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file, 120 p, 2008. http://proquest.umi.com/pqdweb?did=1459918071&sid=9&Fmt=2&clientId=8331&RQT=309&VName=PQD.
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Stiles, Spencer R. "The effects on the antimicrobial properties of Hoshino's triple antibiotic paste when chlorhexidine gluconate (0.12%) is substituted for the propylene glycol and macrogol ointment mixture." Morgantown, W. Va. : [West Virginia University Libraries], 2010. http://hdl.handle.net/10450/11207.
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Thesis (M.S.)--West Virginia University, 2010.Title from document title page. Document formatted into pages; contains v, 47 p. : col. ill. Includes abstract. Includes bibliographical references (p. 44-47).
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Echeverría, Medina Mayra Fernanda. "Anti-staphylococcal properties of four plant extracts against sensitive and multi-resistant bacterial strains isolated from cattle and rabbits." Tesis de Licenciatura, Universidad Autonoma del Estado de México, 2018. http://hdl.handle.net/20.500.11799/95124.
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The aim of this study is to investigate the biopotency of methanolic extracts of Vitex mollis, Psidium guajava,
Dalbergia retusa, and Crescential alata leaves against various staphylococcal strains isolated from cattle and
rabbits. Methicillin-resistant S. aureus strains were isolated from cattle, while other strains were isolated from
rabbits using standard methodology. The total phytochemical phenolic and saponins contents were obtained
being the main groups of the antinutritional factors. The antimicrobial activity of the extracts against the
standard culture of S. aureus (control) and S. aureus isolated from cattle and rabbits were investigated comparatively
relative to that of oxacillin. It was found that both the control S. aureus and the isolated S. aureus are
susceptible to all the four plant extracts, and sensitive to oxacillin. Of all the S. aureus including the control,
MRSA2 is the most susceptible to all the extracts at 1000 μg/mL, except that of V. mollis where it is the least
susceptible. Among all the plant extracts, P. guajava is the most active against MRSA2 and SOSA2. Therefore, the
isolates from cattle (MRSA1 and MRSA2) are more susceptible to all the plant extracts than the isolates from
rabbits. Among all the rabbit isolates, CoNS3 is the least susceptible to the extracts. Since all the plant extracts
exhibit remarkable inhibitory activities against all the S. aureus strains, they are promising towards the production
of therapeutic drugs.
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Ye, Ni-Jyun, and 葉倪君. "Anti-bacterial and anti-inflammatory properties of Plectranthus amboinicus (Lour.) Spreng extracts." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/wep688.
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碩士嘉南藥理大學
生物科技系
102
Acne is a common skin problem and usually appears in many teenagers and young adults with hormone imbalance, bacterial infection, food or cosmetic application. Plectranthus amboinicus is a plant of the Lamiaceae family. The heavy and strong scent of P. amboinicus has been used for centuries in perfumes, and more recently in insect repellents, and alternative medicines. Most of pharmacological studies indicated that the essential oil from P. amboinicus has modulatory effect on gastrointestinal tract, antibacterial activity, anti-inflammatory and analgesic effect. In this research, we aimed to isolate the polyphenols, instead of the essential oil, from the leaves of P. amboinicus and to test its therapeutic effects on acne. The total polyphenol concentrations and in vitro antioxidant activity in crude ethanol extract, n-hexane layer, methanol layer, n-butanol layer, and water layer, were investigated. We found the methanol layer, exhibited the highest total phenol content (167.79 ± 12.67 mg of gallic acid/mg of dry weight), DPPH and ABTS+ radical cation scavenging activities (IC50=27 ± 2 mg/mL and 21 ± 2 mg/mL, respectively) and Trolox equivalent antioxidant capacity (TEAC=0.38 μg TE /μg). However, the other three layers showed no or little activity to scavenge DPPH and ABTS. Furthermore, the crude ethanol extract and the methanol layer were tested for anti-bacterial activity against Propionibacterium acnes and Staphylococcus aureus, which have been recognized as pus-forming bacteria triggering an inflammation in acne. Disc diffusion and broth microdilution were employed. Disc diffusion method showed that the 5 mg methanol layer exhibited 23 mm of inhibition zones against P. acnes, respectively. Crude ethanol extract did not show clear inhibition zone. The MIC values against Staphylococcus aureus for crude ethanol extract and methanol layer were 2.5 mg/mL and 0.3 mg/mL, respectively. On the other hand, the MIC values against Propionibacterium acnes were about 2 mg/mL and 0.3 mg/mL for crude ethanol extract and methanol layer, respectively. The anti-inflammatory effects of crude ethanol extract and the methanol layer were examined in LPS-induced RAW264.7 cells. The methanol layer with the highest phenolic content, exhibited dose-dependent inhibitory effect against LPS-mediated nitric oxide (NO) release, without affecting cell viability in RAW264.7 macrophages. The methanol layer also significantly downregulated the expression of LPS-induced protein expression of iNOS (inducible NO synthase) and COX-2 (cyclooxygenase-2); while upregulated HO-1 (heme oxygenase-1) expression. To sum up, the methanol layer of P. amboinicus may serve as an attractive candidate in complementary and alternative medicine for the treatment of acne.
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Huang, Chu-Wen, and 黃主文. "Anti-Bacterial and Anti-Fouling Properties of the Mixed Self-Assembled Monolayers Study." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/97hr52.
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碩士國立虎尾科技大學
機械與機電工程研究所
100
With the progress of the times a hydrophobic film because of the water-resistant and anti-fog and prevent pollution characteristics has been widely used. Similar to the effective control of surface properties of the material self-assembled thin films (SAMs), and the production process is simple and high stability, spontaneous monolayers adsorbed on the substrate to form a self-assembly film of ordered and closely in recent years has been widely applications in many fields such as biomedical applications, optical, electrical machinery, mechanical engineering and so on. Established antimicrobial fouling of the surface film to reach a self-assembled thin-film technology, the use of organic silane class of self-assembled film formed on the optical lens through the mix of antimicrobial pharmaceutical hydrophobic self-assembled films, composed of the case, transmittance, surface cleanlinessand contact angle performance, re-use of the above conditions to work out the best mixed antibacterial self-assembly film. Prepared nine kinds of self-assembled monolayers of ODS OTS, ODS increase the concentration of 10% anti-bacterial pharmaceutical experiments, the OTS added concentration of 10% anti-bacterial pharmaceutical ODS increase the concentration of 50 % antibacterial Pharmacy, the OTS added concentration of 50 % anti-bacterial pharmaceutical, and is divided into strengthen the treatment and untreated groups, surface plasma interface at different temperatures, the oscillation frequency, speed and soaking time and TEOS plus ODS, TEOS plus ODS plus antibacterial 10 % and 50 %, at different speeds, self-assembly film experiment, the study found that tiny self-assembled film on the nature of the transmittance of the optical lens. The best effect, and TEOS plus ODS together with antimicrobial 10 antimicrobial 10 % and 50 % of the six kinds of ODS and OTS, and coupled with self-assembled films contact angle experiments, reaction time 12 hours, temperature 60 ° C 10 % and 50 % of the three kinds of self-assembled film, the maximum angle of the TEOS plus ODS 12 hours of reaction time, temperature at 40 ℃, the speed of 200 rpm, the contact angle up to 160 ° or more. Lens and self-assembled film interface strengthening treatment, can be found in the ODS self-assembled film, the critical load of ODS mixing concentration of 50 % of antimicrobial agents can be increased by 51.1 %, 54.46 %. The analysis results show that the adhesion TEOS plus ODS have the best adhesion, but after a variety of pharmaceutical re-joined the anti-bacterial, whether it is on the adhesion strength, roughness and contact angle, there are a downward trend by ESCA photoelectron spectrometernine kinds of experimental data that can be learned are self-assembled film was hydrolyzed in solution and the formation of bonding film on the substrate surface. Therefore summarize the results above, self-assembled film of ODS + Anti50 % mixed antibacterial best TEOS + ODS hydrophobic contact angle with appropriate antimicrobial, but still needs to improve its self-assembled film of surface cleaning degrees.
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Yu, Chia-Chun, and 余佳峻. "Studies in Tribological and Anti-bacterial Properties of Organosilane on Glass." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/65sf9z.
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碩士國立虎尾科技大學
機械與機電工程研究所
103
The glass is ectensively applied in the industry and the daily necessities, for examply biomedical engineering, microelectromechanical, sensor, copper oxide photovoltaic cell, touch screens, glasses, and allkinds of windows, etc…many of these glass used in public places, and in the public places a lot of dirt and glass residue virus. If we can use a simple coating on glass reduces the adhesion of dirt and bacteria breeding, will be able to increase the aesthetics of each other and to avoid contagious diseases to environmental pollution.To promote the improvement of the value of gless, the society will be a great boon. Some self-assembled monolayer film made simple, In the past, already has a stain-resistant and reliable and stable system, but mixed self-assembled film fow success stories in the research, because of factors made complicated and not easy to control OTS mixed self-assembled film made simple step, low cost these thesis used taguchi method design and find the best of made arguments, so we can simply be coated on the glass and increasing antibacterial function.Let this coating multifunctional.The experimental results show Ethanol, Toluene, n-Heptane, compared with eachother in different solvents, tound effect, in the soaking temperature 30 ℃, ding temperature 25 ℃,soaking time 6 hrs, as hoc agent concentration 15 mM , under condition of Antibacterial agent concentration 10% contactis reach 130.1°. Surface adhesion reduced original 80%, and this film antimicrobial effects made bacteria reach only 0.63 CFU / cm2, much higfer than the industry and lifestyle applications, standard. The second part of the use sol gel method to as the precursors, different solvents, different additives etc, paremeeters of the glass surface modification, and plated OTS mixed self-assembled film contact angle of up to 117° expressed with stain resistance and antibacterial.
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Peng, Pei-Wen, and 彭珮雯. "Integral Research of Biomedical Alloys and Anti-bacterial Properties on Dental Engineering System." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/82859229555532756156.
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博士臺灣大學
機械工程學研究所
98
In the current study of dental engineering system, the holistic researches regarding the potential biomaterials, surface modification and antibacterial properties had been conducted. From the perspectives of the material forming and machinability, we were attempt to study microstructure and mechanical behavior of the duplex (α + β) Ti-4.8Al-2.5Mo-1.4V alloy, the bacterial response to stainless steels with various amount of antibacterial agents and the machinability of the Fe-9Al-30Mn-1C-3Cr alloy. In addition, the microstructure and material properties and iomechanical behaviors of the titanium with electrical-discharging process were investigated. First of all, in the study of the duplex Ti-4.8Al-2.5Mo-1.4V (Ti14) alloy, the phase transformation sequence was found to be (α + β) → (α + β + α′) → (α′ + α″ + residual β) during heat-treatment between 600°C and 1000°C. The (α′ + α″ + residual β) structure exhibited the maximum yield strength (σy = 920 MPa), hardness (HRC 36), and damping coefficient (188.3 × 10-4). However, the (α + β) structure achieved the greatest elongation (~15%). It is believed that the lath-like α′ martensite not only increases the tensile strength, but also enhances the hardness of the Ti14 alloy. Moreover, it also plays a crucial role in increasing the damping capacity of the Ti14 alloy. The Ag-rich compound was consisted of Fe and Ag elements, and belongs to a FCC structure with the lattice parameter a = 0.251 nm in our antibacterial analysis. No precipitates were found within the matrix and grain boundaries in the present alloys after SHT. When the alloy contains about 0.3 wt.% Ag, it has excellent antibacterial property against both E. coli and S. aureus. It has an AR nearly of 100%. The effects of phase transformation in the Fe-9Al-30Mn-1C-3Cr alloy on machinability were studied. The relationship among surface roughness (R), cutting velocity (V), feed (f), and cutting depth (d) was found to be R = 0.9281 V-0.5337 f0.4914 d0.0667. Moreover, after machining, hardening of the surface layer to around HV 600 was observed. Transmission electron microscopy (TEM) revealed some κ phase carbides ((Fe,Mn)3AlCx) having an order L′12 structure with lattice parameter a = 0.375 nm in the hardened layer. Furthermore, the heat transfer coefficient of the present alloy (0.083 cal/cm2 s °C) was found to be lower than that of AISI 304 stainless steel (0.098 cal/cm2 s °C). The cutting temperature during machining was approximately 620°C. It is noted that these results have not been previously reported in Fe-Al-Mn-C and Fe-Al-Mn-C-Cr alloys. Nano-(γ-TiH) and nano-(γ-TiH and δ-TiH0.71) phases were formed by the natural penetration of hydrogen, and lectrical-discharging, respectively. A nanostructural surface and an oxidation layer were formed by the dissolution reactions of nano-(γ-TiH and δ-TiH0.71) phases. Nano-(γ-TiH and δ-TiH0.71) phases are important in the formation of a nanoporous and nanostructural TiO2 layer. The presence of nano-(γ-TiH and δ-TiH0.71) phases on titanium is critical in the preparation of a thick and nanoporous TiO2 layer by electrical-discharging. In our biomechanical analysis, the difference of stress distribution between fixture and bone tissue was reduced following electrical-discharging. Therefore, the more uniform stress distribution was presented around the Ti-implant interface with the surface modification. From the biomechanical perspective, early healing and osseointegration would be obtained with electrical-discharging.
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Lin, Ming-Hong, and 林明宏. "Bio-implantation and Anti-bacterial properties of the Ag-doped DLC nanocomposite films." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/ntsqpn.
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碩士國立臺北科技大學
機電整合研究所
102
Diamond-like carbon(DLC) films have a lot of physical and chemical properties, like high hardness, electrical resistance, chemical inertness, especially ensure high biocompatibility. In this study, DLC and Ag-doped DLC(Ag-DLC) nanocoposite films were deposited on silicon substrate by R.F. unbalanced magnetron sputtering technique. It is shown that the DLC films had smooth surface and good chemical inertness. Ag-DLC nanocoposite films had different nano-silver sizes, higher hydrophobicity and surface roughness. In biological experiments, thin films were conducted in cell culture and bacteria experiment. MG-63 cells were cultured on substrates of Si、Ti6Al4V、glass、DLC and Ag-doped DLC nanocoposite films. The vitro tests revealed that MG-63 cell attached on DLC films but Ag-doped DLC nanocoposite films not and cytotoxicity tests shown Ag-doped DLC nanocoposite films did not release toxicity. In anti-bacterial test, DLC films had little number of E. coli attached on surface. Ag-doped DLC nanocoposite films surface did not have any E. coli attached and killed E.coli in bacterial solution. It confirmed Ag-doped DLC nanocoposite films have good antibacterial properties.
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林永豐. "The study on the microstructure and properties of the austenitic anti-bacterial stainless steels." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/64245585954767917974.
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Cheng, Ming-Kai, and 鄭名凱. "Effect of annealing on wear-resistant and anti-bacterial properties of TaN-Cu nanocomposite thin films." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/97536434878051919616.
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碩士明志科技大學
化工與材料工程研究所
95
TaN–Cu nanocomposite films were deposited by reactive co-sputtering on Si and tool steel substrates. The films were then annealed using RTA (Rapid Thermal Annealing) at 400 C for 2、4、8 minutes respectively to induce the nucleation and growth of Cu particles in TaN matrix and on film surface. C-AFM (Conductive Atomic Force Microscopy)、SSPM (Scanning Surface Potential Microscopy)and FESEM (Field Emission Scanning Electron Microscopy) were applied to characterize Cu nano-particles emerged on the surface of TaN-Cu thin films. The effect of annealing on anti-wear and anti-bacterial properties of these films was studied. The results reveal that annealing by RTA can cause Cu nano-particles to emerge on the TaN surface. Consequently, hardness and friction coefficients will change, as well as the anti-bacterial behavior.，According to the results TaN-11at%Cu has the best anti-bacterial behavior (reach >99%),While TaN-1.4at% has the highest hardness at 27.5 GPa,after 8-minute annealing。
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Wang, Yen-Wen, and 王彥文. "Fabrication of Ag/TiO2 Foams via Pickering Emulsion: A Study on Anti-bacterial and Photo-catalytic Properties." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/52915429817402430997.
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碩士國立中興大學
材料科學與工程學系所
104
This research aims to prepare Ag/TiO2 foams with macroporous structures via Pickering emulsion, in which the Ag/TiO2 particles consisted of a core/shell structure with a mesoporous TiO2 shell. X-ray diffraction revealed that the Ag/TiO2 particles were anatase structure. The BET surface area was 134 m2/g and average pore diameter was 12 nm, respecticall. Different surfactants were used to modify the surface of the Ag/TiO2 particles in solvent. By selective adsorption of nonionic 1-hxadecylamine (HDA) molecules on the Ag/TiO2 particles, an initially hydrophilic surface became partly hydrophobic. The contact angle increased from 23o to 80o by the HDA adsorption. Ag/TiO2 foams were then prepared by a simple mechanical frothing of the aqueous suspensions consisting of the hydrophobic Ag/TiO2 particles as the filler phase. The partly hydrophobic particles moved to the air-water interface so that the bubbles were protected from coalescence, drainage and disportionation to occur between the neighboring bubbles. Finally, macroporous Ag/TiO2 foams were prepared after calcination at moderate temperatures and their photocatalysis and bactericide activities were examined. For the UV photocatalysis, degradation efficiency against MB dye in water only increased from 29% to 32% when the composite foams were prepared with an increasing molar fraction of TiO2. For the bactericide, efficiency of killing E coli was apparent in 1 h. When time was extended to 3 h, the bactericidal efficiency reached 99%.
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Jenks, Daniel Brent. "The effects of concentration and treatment time on the residual antibacterial properties of DAP." Thesis, 2016. http://hdl.handle.net/1805/10233.
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Indiana University-Purdue University Indianapolis (IUPUI)
Endodontic Regeneration
Graduate Endodontic DepartmentIntroduction: Regenerative endodontic procedures are used to treat immature teeth with pulpal necrosis in order to control infection, enable continued root development and enhance formation of a pulp like tissue in the canal. Canal disinfection is an integral part the regenerative endodontic process. Double antibiotic paste (DAP; i.e., equal parts of ciprofloxacin and metronidazole) has been successfully used for canal disinfection in regenerative endodontics. A comparison of the residual antibacterial effect of dentin treated with various dilutions of DAP pastes on biofilm formation has not yet been investigated thoroughly. Objectives: The aims of this in-vitro study were to investigate how concentration and time of treatment affect the residual antibacterial properties of DAP in preventing E. faecalis biofilm formation on human dentin. Materials and Methods: Extracted human teeth were used to obtain 4x4mm radicular dentin specimens. Each specimen was pretreated for 1 or 4 weeks with the 77 clinically used concentration of DAP (500 mg/mL), low concentrations of DAP (1, 5 or 50 mg/mL) loaded into a methylcellulose system, calcium hydroxide (Ca(OH)2), or placebo paste. After treatment, samples were rinsed and placed in sterile phosphate buffered saline (PBS) for three weeks. Samples were then inoculated with cultured E. faecalis and incubated in anaerobic conditions for three weeks to allow mature biofilm formation. The dentin samples were rinsed and biofilms detached. The detached biofilm cells were then diluted and spirally plated for enumeration on blood agar plates. The plates were then incubated for 24 h and the number of CFUs/mL was determined using an automated colony counter. Data was analyzed using Fisher’s Exact and Wilcoxon rank sum tests were used for statistical comparisons (α=0.05). Results: Dentin pretreatment for 4 weeks with 5, 50 or 500 mg/mL of DAP demonstrated significantly higher residual antibacterial effects and complete eradication of E. faecalis biofilms in comparison to a 1 week pretreatment with similar concentrations. However, dentin pretreated with 1 mg/mL of DAP or Ca(OH)2 did not provide a substantial residual antibacterial effect regardless of the application time. Conclusion: Dentin treated with 500, 50, or 5 mg/mL of DAP for 4 weeks was able to completely prevent the colonization of bacterial biofilm. Four-week treatment of dentin with DAP offers superior residual antibacterial effect in comparison to a one-week treatment. Intracanal application of DAP for 4 weeks during endodontic regeneration may offer an extended residual antibacterial effect.
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Cheng, Chia-Chin, and 鄭嘉晉. "Jingle-bell Shaped Titanium Dioxide Hollow Spheres with Silver Core: A Study on the Fabrication, Anti-bacterial and Photo-catalytic Properties." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/13064635552761916057.
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碩士國立中興大學
材料科學與工程學系所
100
Jingle-bell shaped titanium dioxide (TiO2) hollow spheres with silver (Ag) core (Ag@TiO2 jingle-bell shaped structure) have been prepared by layer by layer assembly method with silicon dioxide (SiO2) as sacrificial template. Ag cores are synthesized by chemical reduction method in H2O solvent with silver nitrate (AgNO3) as the Ag precursor, polyvinylpyrrolidone (PVP) as capping agent and glucose (C6H12O6) as reducing agent. The average size of silver particles can be tailored by adjusting PVP / AgNO3 weight ratio. For example, the average particle size of silver deceased from 357.9 ± 8.1 nm (at PVP / AgNO3 weight ratio of 0) to 81.2 ± 1.1 nm (at PVP / AgNO3 of 2). The Ag particles are encapsulated as cores by SiO2 adsorption via sol-gel Stober method. The average particle size of Ag@SiO2 core shell particles deceased from 576.1±4.1nm to 231.1±1.9nm by adjusting H2O / TEOS molar ratio from 30 to 250; whilst the fraction of successful encapsulation increased from 55.1% to 99.2% observed by TEM and image pro analytic software. The Ag@TiO2 jingle-bell shaped structure (or nanorattles) is obtained from Ag@SiO2 covered by titanium (Ⅳ) butoxide (TBOT) precursor, then the SiO2 sacrificial template is removed by hydrofluoric acid after 450oC calcination. Shell thickness of the Ag@TiO2 jingle-bell shaped structure can be varied from 16.5±2.9nm to 32.2±3.8nm by adjusting the TBOT concentration from 0.058 to 0.145M. For the Ag@TiO2 jingle-bell shaped structure with BET surface area of 48 m2 g-1, photocatalytic efficiency against methylene blue dye is 55% under UV irradiation. Antibacterial efficiency of the Ag@TiO2 jingle-bell shaped structure against E. coli is 100% incubated for 24hrs.
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Yu, Shih-hsien, and 游士賢. "Studies of surface grafting control and characterization of zwitterionic polymer brushes on tissue culture polystyrene plates and of their anti-bacterial properties." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/xcrxw2.
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碩士國立中央大學
化學工程與材料工程研究所
97
In this study, polystyrene surfaces were grafted with zwitterionic polymer brushes of poly(sulfobetaine methacrylate) (polySBMA) ,non-charged polymer brushes of poly(ethylene methacrylate) (polyPEGMA), positive-charged polymer brushes of poly(Sulfopropyl methacrylate) (polySA) and negative-charged polymer brushes of poly(trimethylammonium methacrylate) (polyTM). These were prepared via surface-activated ozone treatment and thermally induced graft copolymerization.Surface packing property of polymer brushes exhibited controllable packing and showed different surface hydrophilicity. The hydration behavior of polymer chains on the resulting TCPS plates can be controlled by the grafting density of polymer on the TCPS surface. In this study, we quantify how surface packing densities of polymer affect bacterial adhesion and biofilm formation on the modified surfaces, and then compare fibroblast cell and bacteria attachment on the material surface owing to electrostatic interaction , or hydrophilic and hydrophilic interaction, between the biological molecules and material surfaces. A well-packed polymer grafted surface via surface-initiated atom transfer radical polymerization (ATRP) was also studied for comparison of anti-bacterial and un-modified TCPS surface was chosen as reference. The short-term adhesion (3 h) and the long-term accumulation (24 h) of two bacterial species (Gram-positive Staphylococcus epidermidis and Gram-negative Escherichia coli), and fibroblast cells on these surfaces in static or dynamic incubation at 37oC to observe the biological molecules attached on the surfaces of modified materials in two culture system. The relative cell adhesion on the surface grafted by charged polymer(polySA and polyTM) were both not reduced, especially for positive-charged polyTM、non-charged polymer (polyPEGMA) and zwitterionic neutral polymer (polySBMA) will be effectively suppressed. Relative bacterial adhesion on the surface, except for positive-charged polyTM,negative-charged polySA、non-charged polymer (polyPEGMA) and zwitterionic neutral polymer (polySBMA) was effectively reduced with increasing surface packing densities of polymer brush grafted on the TCPS surface. The major reason was responsible for the electrostatic interaction between negative charge of bacteria surface and the material surfaces. However, the increasing amount of Staphylococcus epidermidis short/long-term accumulation on the modified materials in the static incubation was more than Escherichia coli, and in the dynamic incubation, the detachable numbers of Staphylococcus epidermidis was also larger than Escherichia coli. Above results was shown the attachment rate of Staphylococcus epidermidis was faster than Escherichia coli, and Escherichia coli were hard to remove once they attached on the materials because of their cell surface was more hydrophilic than Staphylococcus epidermidis.
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Yeh, T. H., and 葉子豪. "Surface emergence and dissolution of Ag and Cu-Ag nanoparticles on TaN thin films and their effects on films' mechanical and anti-bacterial properties." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/10983907587963262442.
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碩士明志科技大學
材料工程研究所
98
Ag and Cu, when used as dopants, are proved immiscible with TaN, which makes the synthesis of TaN -Ag or -Cu nanocomposite thin films possible [5]. Recently, it was reported that the mechanical properties of Ag- or Cu- doped TaN films could be improved after rapid thermal annealing (RTA), due to the formation of metal nanoparticles in the matrix. In a previous study, it was also shown that Ag and Cu particles could form on the surface of TaN, which consequently made these TaN-metal nanocomposite promising antibacterial films. It is found that the anti-bacterial efficiency depends on metal type, emerged particle size, and total exposed metal amount. However, up to date, there is no study on the comparison of TaN-Cu and TaN-Ag against Gram-negative (ex: E. Coli.) and Gram-positive (ex: S. aureus) bacteria. Also, there is no study on the possibility of rejuvenation for these films. Furthermore, there is no study on TaN-(Cu,Ag) composite thin films. The present study makes attempts to (1) compare the anti-bacterial efficiency of TaN-Ag and TaN-Cu against E. coli and S. aureus, (2) study the rejuvenating behavior of TaN-Cu thin films, and (3) study the anti-bacteria and anti-wear behaviors of TaN-(Cu,Ag) thin films. It is hoped that these films would combine the advantages of TaN-Ag and TaN-Cu. TaN-Cu, TaN-Ag and TaN–(Cu,Ag) nanocomposite films were deposited by reactive co-sputtering on Si and tool steel substrates. TaN-Cu and TaN-Ag films were then annealed using RTA (Rapid Thermal Annealing) at 400C for 2, 4, 8, 15 minutes respectively, TaN-(Cu,Ag) films were then annealed using RTA at 200, 250, 300, 350, 400C for 4 minutes respectively to induce the nucleation and growth of metal particles in TaN matrix and on film surface. C-AFM (Conductive Atomic Force Microscopy), FESEM (Field-emission Scanning Electron Microscopy) were applied to characterize the size of metal nano-particles emerged on the surface of these thin films. The effect of annealing on mechanical and anti-bacterial properties of these films was studied. A nano-indenter and a pin-on-disc tribometer were used to study the effect of annealing on the films’ mechanical properties. On the other hand, ICP-MS (Inductively Coupled Plasma Mass Spectrophotometer) was applied to characterize the Cu and Ag ion’s dissolving rate. The samples were tested for their anti-bacterial behaviors against Gram-negative and Gram-positive bacteria. The antibacterial efficiency was correlated with Ag and Cu ion concentrations in buffer solution. Under similar ion concentrations, it is concluded that Ag ion or TaN-Ag is more effective against E. Coli (Gram-negative), while Cu ion or TaN-Cu is more effective against Staphylococcus aureus (Gram-positive). Part of this study is aiming at the rejuvenating behavior of TaN-Cu nanocomposite thin films. After being rejuvenated, TaN-Cu films appear to recover their antibacterial behaviors. However, the mechanical properties of TaN-Cu nanocomposite thin films would deteriorate with the increased number of rejuvention. For the study of TaN-(Cu,Ag) nanocomposite films, the results show that these films could be annealed at a temperature as low as 250℃, and exhibit excellent antibacterial property against E.coli and S.aureus. The antibacterial efficiency may increase with the increase of annealing temperature. Furthermore, hardness may increase with the increase of annealing temperature, while friction coefficient and wear rate decrease with the increase of annealing temperature.
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Yassen, Ghaeth H. "The effect of endodontic regeneration medicaments on mechanical properties of radicular dentin." Thesis, 2013. http://hdl.handle.net/1805/3226.
Full textAbstract:
Indiana University-Purdue University Indianapolis (IUPUI)Endodontic regeneration treatment of necrotic immature teeth has gained popularity in recent years. The approach suggests a biological alternative to induce a continuous root development. In this project, three in vitro experiments were conducted to investigate the effect of three medicaments used in endodontic regeneration on mechanical properties and chemical structure of radicular dentin. In the first experiment, we investigated longitudinally the effect of medicaments on the indentation properties of the root canal surface of immature teeth using a novel BioDent reference point indenter. A significant difference in the majority of indentation parameters between all groups was found after one-week and one-month application of medicaments (p<0.0001): triple antibiotic paste (TAP) > double antibiotic paste (DAP) > control > calcium hydroxide [Ca(OH)2]. The four-week exposure of dentin to TAP and DAP caused 43% and 31% increase in total indentation distance outcome, respectively. In the second experiment, we investigated longitudinally the effect of medicaments on the chemical structure of immature radicular dentin by measuring the phosphate/amide I ratios of dentin using Attenuated Total Reflection Fourier Transform Infrared Spectroscopy. Phosphate/amide I ratios were significantly different between the four groups after one week, two weeks and four week application of medicaments (p<0.0001): Ca(OH)2-treated dentin > untreated dentin > DAP-treated dentin > TAP-treated dentin. In the third experiment, we investigated longitudinally the effect of medicaments on root fracture resistance and microhardness of radicular dentin. For the microhardness, the two-way interaction between group and time was significant (p<0.001). TAP and DAP caused a significant and continuous decrease in dentin microhardness after one and three month application, respectively. The three-month intracanal application of Ca(OH)2 significantly increased the microhardness of root dentin. The time factor had a significant effect on fracture resistance (p<0.001). All medicaments caused significant decrease in fracture resistance ranging between 19%-30% after three month application compared to one week application. The three medicaments used in endodontic regeneration caused significant change in the chemical integrity of the superficial radicular dentin and significantly affected the indentation properties of the root canal surface. Furthermore, the three month intracanal application of medicaments significantly reduced the fracture resistance of roots.
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Hamilton, Maria Fernanda 1981. "Effect of nylon-6 and chitosan nanofibers on the physicomechanical and antibacterial properties of an experimental resin-based sealant." Thesis, 2014. http://hdl.handle.net/1805/6496.
Full textAbstract:
Indiana University-Purdue University Indianapolis (IUPUI)Purpose: Dental sealant forms a physical barrier to prevent pit and fissure caries; therefore, the retention rate becomes a main factor of the sealant’s effectiveness. Electrospun nylon-6/N6 nanofibers have shown good mechanical properties, such as high tensile strength and fracture toughness. Chitosan/CH has received significant attention due to properties such as antibacterial activity. The purpose of this study was to synthesize and evaluate the effect of incorporating N6 and CH electrospun nanofibers on the physical-mechanical and antibacterial properties of an experimental resin-based sealant. Methods and Materials: Nanofiber synthesis: N6 pellets were dissolved in 1,1,1,3,3,3-hexafluoro-2-propanol at a concentration of 10wt%. Practical-grade chitosan was dissolved in trifluoroacetic acid and dichloromethane (60:40 TFA/DCM) at 7 wt%. Electrospinning parameters were optimized in order to fabricate defect-free N6 and chitosan nanofiber mats. Morphological and chemical characterizations were performed by scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy, respectively after vacuum drying the mats for 48 h. The average fiber diameter was determined from SEM images by measuring the diameter of 120 fibers using ImageJ software. Experimental Sealant: N6 and CH electrospun mats (3×3cm2) were immersed into a resin mixture of BIS-GMA/TEGDMA. Once no bubbles were seen, the resin-modified N6 and CH mats were put on a glass plate, light-cured (“TRIAD 2000”) for 2 min and then submitted to a cryomilling process to obtain a fine micron-sized powder. Three different filler levels (1 wt%, 2.5 wt%, 5 wt%) were used to prepare the N6 and CH incorporated resin-based sealants. Additionally, a commercially available resin-based sealant and the experimental resin mixture (unfilled) were used as controls. Three-point flexural testing, Vickers microhardness testing, and agar diffusion testing were performed on the experimental sealants and the commercial sealant. Data were analyzed by one-way ANOVA and Fisher's Protected Least Significant Differences Pair-wise comparisons between groups (5%). Results: The average fiber diameter for N6 was found to be 503±304 nm and 595±411 nm for CH. No significant difference was found between fiber diameter (p = 0.0601). FTIR confirmed the characteristic peaks for N6 ((CO-NH and [-(CH2)5-].) and CH (N-H and C2F3O2-). CH-5% group had significantly higher (p = 0.0000) FS (115.3±4.5 MPa) than all other groups. CH-1% and CH-2.5% groups had significantly higher FS than the control (unfilled) (p = 0.0016 and p = 0.0033 respectively); Helioseal Clear (p = 0.0000), and nylon groups. N6-5% had significantly higher flexural strength than Helioseal Clear (p = 0.0013) and N6-2.5% (p = 0.0250). CH-1% had significantly higher hardness values than all other groups, and CH-5% (p = 0.0414) had significantly higher values than N6-2.5%. No antibacterial inhibition was seen in any of the tested groups. Conclusions: CH and N6 nanofibers were successfully prepared via electrospinning and used to modify the experimental resin-based dental sealants. The overall results indicated that CH-containing sealants presented the highest flexural strength and hardness; however, none of the CH groups displayed antimicrobial properties. Further investigation is needed to enhance the physico-mechanical properties of the experimental resin-based sealants using nylon-6 and CH.
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Osborne, Mathew S. "Comparison of the anti-basal ganglia and anti-phospholipid properties of mAb10F5 and IgG2 subtype controls." 2011. http://liblink.bsu.edu/uhtbin/catkey/1657740.
Full textAbstract:
Group A streptococcal disorders can result from autoantibodies generated against M proteins. These autoantibodies cross react with the basal ganglia resulting in movement disorders. Previously, we demonstrated binding of streptococcal mAb10F5, with CPu and phospholipids. To determine if mAb10F5 binding to basal ganglia and phospholipids is due to virulence of the antibody or antibody subtype, rats were injected with control IgG2 antibodies and euthanized after 24, 48, or 72 hours. Brains were harvested and immunofluorescence was used to analyze brain slices. Control IgG2 rats showed significantly less fluorescence in the CPu than mAb10F5 injected rats at every time point. These findings reaffirm 10F5 is an anti-basal ganglia antibody. To evaluate mechanism of antibody entry, mAb10F5 was examined for anti-phospholipid activity. MAb10F5 displayed greater affinity to phospholipids when compared to
IgG2 controls. Our findings support mAb10F5 is an anti-basal ganglia and anti-phospholipid antibody due to its own virulence.Access to thesis permanently restricted to Ball State community only
Department of Physiology and Health Science