172 research outputs found
Treatment of residual pockets with photodynamic therapy, diode laser, or deep scaling. A randomized, split-mouth controlled clinical trial
The objective of this work was to compare the effects of antimicrobial photodynamic therapy (PDT), diode soft laser therapy (DSL), and thorough deep scaling and root planing (SRP) for treatment of residual pockets. Thirty-two subjects with a history of non-surgical treatment for chronic periodontitis were included. Residual pockets >4mm and bleeding upon probing were debrided with an ultrasonic device and then subjected to either PDT, DSL, or SRP. Pocket probing depth (PPD), bleeding on probing (BOP), and gingival recession were monitored over 6months. Counts of four microorganisms were determined by direct hybridization with RNA probes. PPD decreased from 5.6 ± 1.0 to 3.8 ± 1.1 in 6months (p 4mm with BOP depended on initial PPD (p = 0.036) and was higher if treated with DSL (p = 0.034). Frequencies of three microorganisms were significantly lower in PDT- and SRP-treated than in DSL-treated quadrants (p = 0.02) after 14days, but not at months 2 and 6. All three treatments resulted in a significant clinical improvement. PDT and SRP suppressed Porphyromonas gingivalis, Tannerella forsythia, and Treponema denticola stronger, and resulted in fewer persisting pockets after 6months, than DSL applicatio
HPLC-DAD-MS Fingerprint of Andrographis Paniculata (Burn. f.) Nees (Acanthaceae)
An HPLC-UV fingerprint analysis was developed for the quality evaluation of Andrographis paniculata aerial parts. HPLC-DAD-MS experiments allowed the identification of eleven diterpenes and five flavonoids. Plant material of Indian and Chinese origin was evaluated employing the developed method. The chemical fingerprints of the plant material of different origins do not show significant differences
Executive Functioning and Personality Traits in Insomnia Disorder: A Preliminary Report on the Clinical Importance of Objective and Subjective Reduction of Total Sleep Time
To confirm and extend previous findings on the relationships between executive functioning (EF) and insomnia, as well as the available evidence on the associations between personality traits and insomnia, 30 consecutively-admitted insomnia participants and 30 community dwelling adult participants matched on age, gender and educational level, were administered a battery of EF measures and the Personality Inventory for DSM-5 (PID-5). Insomnia participants underwent two full-night polysomnographic (PSG) recording, followed by a morning assessment of subjective sleep parameters. A misperception index (MI) was computed in order to identify participants characterized by objective insomnia and non-objective insomnia. The EF performance associations between insomnia and poor performance on selected executive functions was confirmed. However, the objective insomnia and non-objective insomnia sub-groups show significant differences on specific EF indices, as well as on dysfunctional personality dimensions
Isothermal austenite-Ferrite phase transformations and microstructural evolution during annealing in super duplex stainless steels
Super Duplex Stainless Steels (SDSSs) are composed of α-ferrite and γ-austenite grains, the simultaneous presence of which forms an optimal microstructure to achieve the best combination of mechanical and corrosion resistance properties. Moreover, international quality standards are strict about the phase fraction ratio. The purpose of this work is the achievement of a better description of the phase ratio evolution taking place during annealing at 1080°C in the super duplex stainless steels F53â\u80\u93S32750 and F55â\u80\u93S32760. The experimental results show a damped sinusoidal trend in the α/γ phase ratio evolution with the increase of the soaking time of thermal treatment. This can be described by coupling both the competitive coarsening growth regime and the concept of the local equilibrium phase transformations, pointing out a good correspondence with the experimental data. Further, recrystallization phenomena also play a major role. Finally, the additivity character of the observed processes has been proven
Heat treatment cycle optimization for A707L5 copper-nickel steel
The mechanical properties of the A707L5 steel grade were studied as a function
of the applied aging temperature. The results obtained are discussed on the basis of the
microstructure analysis and precipitates were identified on the fracture surfaces observed
by scanning electron microscopy assisted by a field emission gun (FEG-SEM). This steel grade
appears to be particularly sensitive to the aging time-temperature, which significantly affected
the precipitation phenomena. The annealing temperature and solution quenching
involved in the thermal cycle significantly affect the perlite formation, the grain size and
the ε-Cu precipitates that represent the main factors of influence ruling the mechanical
properties
Hot-dip aluminizing on AISI F55-UNS S32760 super duplex stainless steel properties: Effect of thermal treatments
The behavior of super duplex stainless steels AISI F55-UNS S32760 in hot-dip aluminizing process has been studied, investigating the influence of cold working and of different initial microstructures obtained through a preliminary thermal treatment. The microstructural features examined are the secondary austenite precipitation, the static recovery of ferrite and the thermal dissolution of austenite within ferritic matrix. The hot-dip aluminizing temperature has been optimized through sessile drop tests. The treatment has been performed at 1100 °C for 300 s, 900 s and 2700 s. A strong chemical interaction occurs, generating intermetallic compounds at the interface. Molten aluminum interacts exclusively with the ferritic phase due to its much higher diffusivity in this phase coupled with its marked ferrite-stabilizer behavior. Thus, the influence of cold working is not remarkable, since the strains are mainly allocated by austenitic phase. The diffusivity of aluminum increases due to lattice defects thermally generated and, mainly, to influence given by grain boundaries, multiplied by secondary austenite precipitation, which act as short-circuit diffusion paths. Ni and Cr contents in the ferritic matrix have an influence but not highly relevant. Then, the best starting condition of the super duplex stainless steel substrates, to obtain a thick interfacial layer, are the thermal annealing at 1080 °C for 360 s/mm after a solution thermal treatment at 1300 °C for 60 s/mm
The Influence of Thermomechanical Processing Conditions on the Evolution of Microstructure and Crystallographic Textures and the Mechanical Properties of Deformed Mild Steels in the Intercritical Region
Rolling temperature and rolling reduction intensively influence the formation of Luder lines and fluting marks in mild steels. They govern these effects through control of strain aging. In order to enhance the strain aging resistance and the consequent reduction of yield point elongation and fluting intensity, warm rolling without using the skin pass process is applied. The development of microstructure and crystallographic textures during deformation process and the determination of fluting intensity and mechanical properties consisting of tensile and formability properties in terms of different thermomechanical conditions (RT and RR%) were investigated in this study. These properties are determined through the use of bending, tensile tests, optical microscope, and EBSD analysis
Impact of warm rolling process parameters on crystallographic textures, microstructure and mechanical properties of low-carbon boron-bearing steels
The effect of the warm rolling process on the microstructure and the mechanical properties of low-carbon high-boron steels are studied in this work. To investigate these effects, boron-bearing low-carbon steel, subjected to roll at three different temperatures, was studied symmetrically and asymmetrically. The results of the experimental trials achieved by mechanical and microstructural analysis revealed that the use of warm rolling can represent a favorable method to suppress strain aging completely, and to eliminate the fluting effect and yield point elongation. In addition, the tensile and elongation properties are modified with the formation of boron nitride precipitates and dislocations in different thermomechanical conditions
Solidification microstructure of centrifugally cast Inconel 625
Centrifugal casting is a foundry process allowing the production of near net-shaped axially symmetrical
components. The present study focuses on the microstructural characterization of centrifugally cast alloys
featuring different chemical compositions for the construction of spheres applied in valves made of alloy IN625
for operation at high pressure. Control of the solidification microstructure is needed to assure the reliability of the
castings. Actually, a Ni-base superalloy such as this one should have an outstanding combination of mechanical
properties, high temperature stability and corrosion resistance. Alloys such as IN625 are characterised by a large
amount of alloying elements and a wide solidification range, so they can be affected by micro-porosity defects,
related to the shrinkage difference between the matrix and the secondary reinforcing phases (Nb-rich carbides
and Laves phase). In this study, the microstructure characterization was performed as a function of the applied
heat treatments and it was coupled with a calorimetric analysis in order to understand the mechanism ruling the
formation of micro-porosities that can assure alloy soundness. The obtained results show that the presence of
micro-porosities is governed by morphology and by the size of the secondary phases, and the presence of the
observed secondary phases is detrimental to corrosion resistance
Effect of periodontal treatment on peak serum levels of inflammatory markers
Background and objective: Some subjects with untreated periodontitis exhibit elevated levels of distinct inflammatory markers in serum. The aim of the study was to assess whether nonsurgical periodontal therapy changes the levels of these markers and lowers these peaks. Methods: Forty periodontally diseased subjects received nonsurgical periodontal therapy (full-mouth scaling and root planing within 48h) with either adjunctive systemic amoxicillin and metronidazole (n = 19) or placebo (n = 21). Serum samples, obtained at baseline (BL) and 3months after treatment (M3), were evaluated for 15 cytokines and 9 acute-phase proteins using the Bio-Plex bead array multianalyte detection system. For each analyte, peak values were defined as greater than the mean + 2 standard deviations (SD) of measurements found in 40 periodontally healthy persons. Proportions were compared using Fisher's exact test. Results: At M3, a significantly better primary clinical outcome (persisting pockets of >4mm with bleeding on probing) was obtained in patients treated with scaling and root planing plus antibiotics compared to those receiving placebo (3.3 ± 5.1 vs. 6.8 ± 7.8 pockets per patient, p < 0.05). The levels of cytokines and acute-phase proteins of periodontitis patients were usually below the mean + 2 SD threshold of healthy persons. However, values above threshold were found in some individuals. Eleven patients showed a peak value of one analyte, and seven patients showed two peaks. In the remaining 12 patients, between three and ten analytes showed peak values. Therapy greatly reduced the number of subjects with four or more peaks (BL, 11 subjects; M3, 1 subject, p = 0.003). With regards to the reduction of peaks, no specific benefit of adjunctive antibiotics could be seen. Conclusion: Subjects with untreated periodontitis may show high peaks for several inflammatory markers in serum simultaneously. Nonsurgical periodontal treatment with or without antibiotics reduced most of these peak levels
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