Effects Of Different Treatment Times Research Articles

Effect of Exposure Times of Sodium Hypochlorite before Acid Etching on the Microshear Bond Strength to Fluorotic Enamel.

To evaluate the effects of different treatment time of 5.25% Sodium hypochlorite (NaOCl) on the microshear bond strength (μSBS), attenuated total reflection Fourier transform infrared (ATR-FTIR) and etching pattern in mild and moderate fluorotic enamel. Forty-eight fluorotic molars were divided into two groups: mild and moderate fluorotic enamel which were classified by a Thylstrup and Fejerskov index (TFI). Based on the application time (0s, 60s, 120s, 180s) of 5.25% NaOCl, each group was sectioned into four parts. Then the etched enamel was bonded with resin and tested to acquire μSBS. The statistical method was two-way ANOVA and Least Significant Difference (LSD) test at α = 0.05. Besides, fracture modes were observed under a stereo microscope. SEM was used to evaluated the enamel-etching pattern and organic content on the fluorotic enamel surface were investigated by ATR-FTIR. Duration of 5.25% NaOCl at 60s or 120s significantly increased the μSBS of fluorotic enamel compared to 0s (p<0.05). Fracture modes indicated that dominating failures were set in the bonding interface but whose proportion decreased when 5.25% NaOCl was applied. The enamel-etching pattern in 180s was deepest under SEM. Spectra of enamel samples manifested an obvious and gradual removal of its organic phase after duration of NaOCl increased. The maximal μSBS is acquired by using 5.25% NaOCl at 60s for mild fluorotic enamel but 120s for the moderate. The prolonged application time of 5.25% NaOCl prior to phosphoric acid etching improves enamel-etching pattern. Treatment of 5.25% NaOCl decreases proteins on the fluorotic enamel surface.

Effect of nitrogen plasma treatment on the hydrophilicity of polycrystalline diamond films with micron-scale grains

Diamond film with micron-scale grains was prepared on silicon substrate by microwave plasma chemical vapor deposition (MPCVD) system. Then, MPCVD equipment was still used to change the experimental conditions, and only nitrogen was used as the gas source, so as to conduct nitrogen plasma treatment on the deposited diamond film. The effects of different treatment time on the structure, morphology and hydrophilicity of diamond films were investigated under the same nitrogen plasma treatment conditions. The results showed that with the increase of nitrogen plasma treatment time, the surface defect density of diamond grains becomes higher and higher, the concentration of nitrogen and sp2C=C composition gradually increase, the hydrophilicity of the corresponding diamond film and deionized water becomes better first (the contact angle between deionized water and diamond film decreases from 97° to 44°), and then, it becomes slightly worse (the contact angle between deionized water and diamond film increases from 44° to 49°). It shows that nitrogen plasma treatment can effectively improve the hydrophilicity of diamond film, and the experimental results are explained reasonably.

Highly Photoluminescent CsPbBr3/CsPb2Br5 NCs@TEOS Nanocomposite in Light-Emitting Diodes.

All-inorganic halide perovskite (CsPb2Br5) nanocrystals (NCs) have received widespread attention owing to their unique photoelectric properties. This work reports a novel strategy to control the phase transition from CsPbBr3 to CsPb2Br5 and investigates the effects of different treatment times and treatment temperatures on perovskite NCs formation. By controlling the volume of tetraethoxysilane (TEOS) added, the formation of different phases of perovskite powder can be well controlled. In addition, a white light-emitting diode (WLED) device is designed by coupling the CsPbBr3/CsPbBr3-CsPb2Br5 NCs@TEOS nanocomposite and CaAlSiN3:Eu2+ commercial phosphor with a 460 nm InGaN blue chip, exhibiting a high luminous efficiency of 57.65 lm/W, color rendering index (CRI) of 91, and a low CCT of 5334 K. The CIE chromaticity coordinates are (0.3363, 0.3419). This work provides a new strategy for the synthesis of CsPbBr3/CsPbBr3-CsPb2Br5 NCs@TEOS nanocomposite, which can be applied to the field of WLEDs and display devices.

Determination of proper treatment time for in vivo blood coagulation and wound healing application by non-thermal helium plasma jet

The aim of this research was to determine the time of blood coagulation of in vivo cuts that treated by the non-thermal atmospheric pressure plasma jet. Also, the effect of different treatment times on wound healing has been studied. The non-thermal atmospheric pressure plasma jet working in helium gas has been used. The averaged treatment time of 8.6s for in vivo cuts on the Balb/c mouse liver showed the complete blood coagulation. Also, the effect of tretament time on wound healing has been studied by applying plasma on the wounds for different times (10, 20, 30, 40 and 50s). It was obtained from morphological analysis that the treatment groups of 30s, 40s and 50s cause the wounds to be healed faster than the groups 10s and 20s.The histological analysis showed that in 30s and 40s treatment time groups, the repair process of treated wounds has been accelerated, while for 50s group, it has not been completed, yet. The 30s treatment time has been chosen because of imposing lower dose to living tissue. The treated wound area reduction ratios against the control wound reduction ratios for 30s group were obtained 78%, 77% and 63% at the 3rd, 5th and 8th days, respectively.

A Chromium Discharge Minimizing Tanning Technology Assisted by O2 Low Temperature Plasma

Substantial quantities of solid and liquid wastes generate in the chrome tanning process, posing major environmental problem if not managed effectively. In order to minimize the emissions of chromium, a high exhaustion chromium tanning method was designed in this study. Low temperature plasma (LTP) technology has the characteristics of economy, pollution-free and high efficiency. The pioneering works were carried out by applying LTP to surface modification of natural leather before tanning process. The effects of different treatment time on micro-structure, chemical compositions, active groups, tanning absorption rate of leather fiber were studied. The SEM results showed that the leather surface was etched rougher. The XPS data showed that the O1s area ratios increased from 18.8 % to 27.6 % after O2 LTP treatment. The optimal O2 plasma treatment time is 10min. The results show O2 LTP treatment effectively improves the chrome tanning absorption rate from 78.68 % of conventional process to 94.47 % of the novel process, which reduces the emission of heavy metal chromium and protects the environment.

Study on Processing Technology and Quality of Moringa oleifera leaves with y - Aminobutyric Acid

In order to obtain the high level of γ-aminobutyric acid Moringa oleifera leaves, Use 7% sodium glutamate solution to soak the fresh Moringa oleifera leaves, study effect of different treatment times and three different drying methods( hot air drying, vacuum freeze drying, shadow drying) on the formation of y-aminobutyric acid and quality (total flavonoids, soluble sugar, amino acids, polyphenols, color)of dried Moringa oleifera leaves. The results indicated that shadow-dried Moringa oleifera leaves had the hightest retention of γ-aminobutyric acid, but its browning degree were not preferable, soluble sugar was damaged gravely, and its vulnerable to weather conditions. Vacuum freeze dried Moringa oleifera leaves had the hightest retention of flavonoids, polyphenols and amino acids. The y-aminobutyric acid content of Vacuum freeze dried and hot air dried Moringa oleifera leaves had no much difference. Hot air dried Moringa oleifera leaves browning degree were preferable, it’s had an moderate content of soluble sugar and amino acids, the short drying time is characteristics of this drying method.with the treatment time increased, the content of γ-aminobutyric acid and amino acids content first increased and then decreased. Flavonoids and polyphenols content first decreased and then increased. Soluble sugar content decreased. In summary, after soaking with 7% sodium glutamate solution for 10h, then dried by hot air drying(drying temperature of 60°C), was the most suitable way for industrial production of the high level of γ-aminobutyric acid Moringa oleifera leaves.

Enhancement of carbon-steel peel adhesion to rubber blend using atmospheric pressure plasma

The surface of carbon-steel plates was modified by non-equilibrium plasma of diffuse coplanar surface barrier discharge (DCSBD) in order to improve the adhesive properties to the NR (natural rubber) green rubber compound. The effect of different treatment times as well as different input power and frequency of supplied high voltage was investigated. The samples were characterized using contact angle and surface free energy measurement, measurement of adhesive properties, scanning electron microscopy (SEM) and atomic force microscopy (AFM). Surface chemical composition was studied by energy-dispersive X-ray spectroscopy (EDX). Significant increase in wettability was observed even after 2 s of plasma exposure. The surface modification was confirmed also by peel test, where the best results were obtained for 6 s of plasma treatment. In addition the ageing effect was studied to investigate the durability of modification, which is crucial for the industrial applications.

Programmed cell death, antioxidant response and oxidative stress in wheat flag leaves induced by chemical hybridization agent SQ-1

Male sterility induced by a chemical hybridization agent (CHA) is an important tool for utilizing crop heterosis. Leaves, especially the flag leaves, as CHA initial recipients play a decisive role in inducing male sterility. To investigate effects of different treatment times of CHA-SQ-1 used, morphological, biochemical and physiological responses of wheat flag leaves were detected in this study. CHA induced programmed cell death (PCD) as shown in terminal deoxynucleotidyl transferase-mediated dUTP nick end-labelling (TUNEL) and DNA laddering analysis. In the early phase, CHA-SQ-1 trig-gered organelle changes and PCD in wheat leaves accompanied by excess production of reactive oxygen species (O2▪ and H2O2) and down-regulation of the activities of superoxide dismutase (SOD), catalase (CAT) and guaiacol peroxidase (POD). Meanwhile, leaf cell DNAs showed ladder-like patterns on agarose gel, indicating that CHA-SQ-1 led to the activation of the responsible endonuclease. The oxidative stress assays showed that lipid peroxidation was strongly activated and photosynthesis was obviously inhibited in SQ-1-induced leaves. However, CHA contents in wheat leaves gradually reduced along with the time CHA-SQ-1 applied. Young flags returned to an oxidative/antioxidative balance and ultimately developed into mature green leaves. These results provide explanation of the relations between PCD and anther abortion and practical application of CHA for hybrid breeding.

Atmospheric pressure plasma treatment on graphene grown by chemical vapor deposition

We demonstrate the surface treatment of graphene using an atmospheric pressure plasma jet (APPJ) system. The graphene was synthesized by a thermal chemical vapor deposition with methane gas. A Mo foil and a SiO2 wafer covered by Ni films were employed to synthesize monolayer and mixed-layered graphene, respectively. The home-built APPJ system was ignited using nitrogen gas to functionalize the graphene surface, and we studied the effect of different treatment times and interdistance between the plasma jet and the graphene surface. After the APPJ treatment, the hydrophobic character of graphene surface changed to hydrophilic. We found that the change is due to the formation of functionalities such as hydroxyl and carboxyl groups. Furthermore, it is worth noting that the nitrogen plasma treatment induced charge doping on graphene, and the pyridinic nitrogen component in the X-ray photoelectron spectroscopy spectrum was significantly enhanced. We conclude that the atmospheric pressure plasma treatment enables controlling the graphene properties without introducing surface defects.

Treatment time of ultrasound therapy interferes with the organization of collagen fibers in rat tendons

The application time of therapeutic ultrasound is an infrequently studied dosimetric variable that affects tissue repair. The aim of this study was to evaluate the effects of different treatment times of therapeutic ultrasound (US) on the organization of collagen fibers in the tendons of rats. Forty Wistar rats were selected (300±45 g), and the rats were divided into five groups (n=8 for each group): Control, without tenotomy or any treatment; tenotomy group, with tenotomy and without treatment; US groups (US1, US2, and US3), subjected to tenotomy and treated with US for one, two, or three minutes per area of the transducer, respectively. The animals were sacrificed on the 12th post-operative day, and the tendons were surgically removed for analyses of the collagen fiber organization by means of birefringence analysis. The collagen fibers exhibited better aggregation and organization in the US3 group compared with the tenotomy group (p<0.05). The findings suggest that US applied for three minutes per treated area improves the organization of collagen fibers during rat tendon repair.

Effects of Treatment Time by Sulfur Hexafluoride (SF6) Plasma on Barrier and Mechanical Properties of Paperboard

Sulfur hexafluoride (SF6) plasma, using inductively coupled plasma technique, was applied on paperboard surfaces. Effects of different treatment times on water and oil resistances, mechanical properties (through tensile, compression and folding endurance tests) and barrier properties [through water vapor transmission rate (WVTR) and oxygen transmission rate (OTR)] were determined. Results showed that SF6 plasma treatment can improve water resistance properties of paperboard significantly, beginning with only a 2 s treatment time (p ≤ 0.05), whereas oil resistance properties can be improved over a longer time period. Plasma treatment had no effect on tensile strength of treated paperboard; however, machine direction (MD) compression strength, as well as MD and CD folding endurance, of treated paperboard was significantly lower than that for an untreated sample (p ≤ 0.05). WVTR and OTR of treated paperboard were higher with increasing treatment time, because of fluorine atoms and electron bombardment causing etching of cellulose fibres. Copyright © 2011 John Wiley &amp; Sons, Ltd.

Preparation of Protein- and Cell-Resistant Surfaces by Hyperthermal Hydrogen Induced Cross-Linking of Poly(ethylene oxide)

The functionalization of surfaces with poly(ethylene oxide) (PEO) is an effective means of imparting resistance to the adsorption of proteins and the attachment and growth of cells, properties that are critical for many biomedical applications. In this work, a new hyperthermal hydrogen induced cross-linking (HHIC) method was explored as a simple one-step approach for attaching PEO to surfaces through the selective cleavage of C-H bonds and subsequent cross-linking of the resulting carbon radicals. In order to study the effects of the process on the polymer, PEO-coated silicon wafers were prepared and the effects of different treatment times were investigated. Subsequently, using an optimized treatment time and a modified butyl polymer with increased affinity for PEO, the technique was applied to butyl rubber surfaces. All of the treated surfaces exhibited significantly reduced protein adsorption and cell growth relative to control surfaces and compared favorably with surfaces that were functionalized with PEO using conventional chemical methods. Thus HHIC is a simple and effective means of attaching PEO to non-functional polymer surfaces.

Screening the Fusarium graminearum inhibitory mutant strain from Bacillus subtilis by atmospheric-pressure plasma jet

The aim of this study was to improve the antagonistic activity of Bacillus subtilis JA towards Fusarium graminearum by screening high-yielding mutant using the atmospheric-pressure plasma jet (APPJ). Atmospheric-pressure plasma jet was applied as mutagenic source for breeding high-yielding mutant strain. Helium was used as APPJ operating gas. The mutation effects of different treatment times of APPJ were studied. The mutant strain designated as B. subtilis B06 was successfully screened out, which showed higher antagonistic activity against F. graminearum in vitro. Its inhibition zone against the indicator fungus increased by 23% compared to the original one. HPLC and ESI (electrospray ionization) mass spectrometry analysis indicated that antifungal compounds produced by the mutant and original strain belonged to the lipopeptide, surfactin and iturin families. The mutant strain showed favourable properties of faster growth in the fermentation process and higher production of antibiotics. The lipopeptide production of the mutant was 2.3-fold as that of the original strain. A mutant strain with strong antagonistic activity and high yielding of antibiotics was obtained by APPJ in this study. The mutant could be used as a promising biocontrol agent in agriculture. This study provides a novel mutagenic source for breeding high-yielding microbial mutant, which would be very useful in the application of some valuable metabolites from micro-organism.