▶ Severe plastic deformation of austenitic stainless steel (SUS 316)by multidirectional forging. ▶ Grain fragmentation by the coordinated effects of mechanical twinning, martensitic transformation ...and continuous dynamic recrystallization. ▶ Uniform evolution of packetswith the size (dp) from 40nm to 100nm. ▶ Ultrafine grains with an average grain size much lower than 50nm. ▶ The superior balance of strength and ductility; 2.1GPa UTS and 20% total elongation. ▶
Nano-grain evolution in an austenitic stainless steel (SUS 316) during multidirectional forging (MDF) was investigated at temperatures of 77K and 300K. The flow stress during MDF and the room-temperature hardness increased significantly with increasing cumulative strain. The initial grains were subdivided by mechanical twinning and martensitic transformation. The formation of packets, which are composed of lamellar-structured mechanical twins with a spacing of 10–300nm, enhanced grain fragmentation. The packet size ranged from 40nm to 100nm depending on the MDF temperature and the cumulative strain. Tensile tests at ambient temperatures revealed a maximum proof strength of 2.1GPa. While the proof strength increased with cumulative strain, the plastic strain at fracture was approximately 10% independent of the cumulative strain over ∑Δɛ=2.4.
Oral care regimens can be explored to improve oral health in patients with gingivitis. This study aimed to evaluate the efficacy of a multicomponent oral care regimen with a dual zinc plus arginine ...(DZA) toothpaste and cetylpyridinium chloride with zinc lactate (CPC + Zn) mouthwash in reducing gingival bleeding in patients with gingivitis.
This randomized clinical trial included 94 participants with gingivitis who were randomized into two groups: the DZA/CPC + Zn group, which used a 1450-ppm fluoride toothpaste containing 0.96% zinc plus 1.5% arginine and a fluoride-containing mouthwash with 0.075% CPC and 0.28% zinc lactate, and the control group, which used a 1450-ppm fluoride toothpaste and a placebo mouthwash for 6 months. All participants were examined by a blinded examiner who measured the gingival index, plaque index, and gingival severity index. Data were analyzed using paired t test, independent t test, and analysis of covariance (ANCOVA).
Both groups presented statistically significant reductions in all clinical parameters compared to baseline. The DZA/CPC + Zn group exhibited significantly greater reductions in gingival index, gingival severity index, proximal gingival index, plaque index and proximal plaque index compared to the control group at 1, 3, and 6 months. Furthermore, DZA/CPC + Zn significantly decreased the percentage of patients with generalized gingivitis over a 6-month follow-up period. However, differences between the DZA/CPC + Zn and the control groups were not maintained after both groups established similar regimens with fluoride toothpaste.
The multicomponent oral care regimen consisting of DZA toothpaste and CPC + Zn mouthwash is effective in reducing gingival inflammation and supragingival biofilm in patients with gingivitis.
Background
It is difficult to achieve stress equilibrium at both ends of the specimen of brittle materials such as ice because cracks are generated during impact compression.
Objective
The present ...study investigated the compressive stress of pure ice at − 10 °C by using the split Hopkinson pressure bar (SHPB) method.
Methods
An SHPB compression test using flanged bars was conducted on pure ice specimens while simultaneously observing their internal deformation and fracture state by using a high-speed camera. The results were analyzed defining that dynamic equilibrium was established when the stress error rate between both ends of the specimen was within ± 15%.
Results
The results demonstrated that establishing the dynamic equilibrium and contact condition between specimen and testing apparatus are crucial for performing the SHPB compression test on ice. They also showed a correlation between crack generation/propagation and stress rate variation and that the fracture stress at strain rates > 10
2
s
−1
can be defined; therefore, the fracture stress measured at strain rates of approximately 10
1
–10
3
s
−1
exhibited a positive strain rate dependence.
Conclusions
The fracture behavior and stress of ice at high strain rates can be determined by combining the SHPB method with high-speed camera observation.
Studying the gravity-dependent characteristics of regolith, fine-grained granular media covering extra-terrestrial bodies is essential for the reliable design and analysis of landers and rovers for ...space exploration. In this study, we propose an experimental approach to examine a granular flow under stable artificial gravity conditions for a long duration generated by a centrifuge at the International Space Station. We also perform a discrete element simulation of the granular flow in both artificial and natural gravity environments. The simulation results verify that the granular flows in artificial and natural gravity are consistent. Further, regression analysis of the experimental results reveals that the mass flow rate of granular flow quantitatively follows a well-known physics-based law with some deviations under low-gravity conditions, implying that the bulk density of the granular media decreases with gravity. This insight also indicates that the bulk density considered in simulation studies of space probes under low-gravity conditions needs to be tuned for their reliable design and analysis.
OBJECTIVE:We hypothesized that using the intima-media thicknesses (IMT) of the common carotid artery (CCA) could help predict the risk for new-onset cardiovascular disease (CVD) events in a ...population-based cohort.
DESIGN AND METHOD:We studied 2,451 men and 2,880 women with carotid atherosclerosis (mean age 59.8 yrs., without CVD at baseline) who completed a baseline survey. They were followed for 12.8 yrs. (avg.) in the Suita Study. Carotid atherosclerosis was evaluated by high-resolution ultrasonography with atherosclerotic indexes of IMT in the CCA, bifurcation, and the internal and external carotid arteries. Max-CCA, -BIF, and -IMT were defined as the maximum IMTs in the CCA, bifurcation, and entire scanned areas, respectively. We compared the risk of CVD by Cox proportional hazards models after adjusting for traditional risk factors at baseline. We evaluated the model discrimination by the area under the receiver operating characteristic curve.
RESULTS:During the follow-up, we documented 244 strokes and 171 coronary heart disease. The adjusted hazard ratios (HRs; 95%CI) in the fourth quartile (> = 1.10 mm) of the Max-CCA for CVD was 2.16 (1.39–3.3) compared with the first quartile (<0.9 mm) adjusting for traditional risk factorsadvancing age, women (HR = 0.61; 95%CI, 0.45–0.81), prehypertension (1.60; 1.15–2.19), grade-1 hypertension (2.08; 1.46–2.94), grade-2/3 hypertension (2.46; 1.70–3.56), antihypertensive drug use (1.31; 1.03–1.66), total cholesterol per 20 mg/dL (1.11; 1.05–1.18), low HDL cholesterol (1.60; 1.24–2.05), and diabetes (1.81; 1.27–2.58). Compared with the first quartile, the adjusted HRs in the fourth quartiles (> = 1.7 mm) of the Max-BIF and Max-IMT were 2.79 (1.72–4.52) and 2.30 (1.33–3.96), respectively. With the presence of plaque defined as Max-CCA > = 1.1 mm, the C statistic (0.7331; 95%CI, 0.7093–0.7570) was almost the same as that with Max-BIF and Max-IMT, and slightly higher than that without presence of plaque i.e. only as for traditional risk factors (0.7215; 0.6983–0.7447).
CONCLUSIONS:In a general Japanese population, high Max-CCA was strongly associated with incident CVD, but only slightly improved CVD prediction when it was added to the model of traditional risk factors.
Incompletely condensed (IC) and completely condensed (CC) polyhedral oligomeric silsesquioxanes (POSSs) tethered with hydrophilic poly(ethylene glycol) (PEG) chains were synthesized and used as novel ...organic-inorganic amphiphilic element-block molecules toward self-assembly nanomaterials. The association behavior of these element-block molecules in water can be controlled based on their chemical structures. The eight PEG chains-containing CC-POSS, with a structure of the hydrophobic CC-POSS center covered with hydrophilic PEG chains, is hydrophilic and can molecularly dissolve in pure water. IC-POSS, which carries three PEG chains with a molecular weight of 2000, is an amphiphilic compound and forms spherical micelles consisting of a hydrophobic IC-POSS core and hydrophilic PEG chain shell. IC-POSS, which carries three PEG chains with a molecular weight of 600, forms polydisperse worm-shaped micelle aggregates, because the hydrophilic PEG chains are very short for stable dispersion of independent spherical micelles. Amphiphilic CC-POSS, which carries branched PEG chains with a molecular weight of 600, forms a vesicle structure, although IC-POSS carrying three PEG chains forms solid micelles in spite of the same PEG number and length. These results strongly indicate that the length of the PEG chain and the shape of the POSS head group play a crucial role in determining the self-assembly structures.
![[OP.5B.07] COMMON CAROTID I...](http://api.summon.serialssolutions.com/2.0.0/image/issn/XR4PS5YY4K/0263-6352/small "[OP.5B.07] COMMON CAROTID INTIMA-MEDIA THICKNESS MEASUEMENTS IMPROVE INCIDENT CARDIOVASCULAR DISEASE PREDICTION IN THE GENERAL POPULATION: THE SUITA STUDY")
PDF