Non-Equilibrium Fluidization of Dense Active Suspension

We investigate dense suspensions of swimming bacteria prepared in a nutrient-exchange chamber. Near the pellet concentration, nonthermal fluctuations showed notable agreement between self and collective behaviors, a phenomenon not previously observed at equilibrium. The viscosity of active suspensions dramatically decreased compared to their inactive counterparts, where glassy features, such as non-Newtonian viscosity and dynamic heterogeneity, disappeared. Instead, the complex shear modulus showed a power-law rheology,$G^*(\omega)\propto\left(-i\omega\right)^\frac{1}{2}$, indicating the role of bacterial activity in driving the system towards a critical jamming state

Coulomb breakup reactions of 93,94 Zr in inverse kinematics

Coulomb breakup reactions of 93,94 Zr have been studied in inverse kinematics at incident beam energies of about 200 MeV/nucleon in order to evaluate neutron capture reaction methods. The 93 Zr(n,γ) 94 Zr reaction is particularly important as a candidate nuclear transmutation reaction for the long-lived fission product 93 Zr in nuclear power plants. One- and two-neutron removal cross sections on Pb and C targets were measured to deduce the inclusive Coulomb breakup cross sections, 375 ± 29 (stat.) ± 30 (syst.) and 403 ± 26 (stat.) ± 31 (syst.) mb for 93 Zr and 94 Zr, respectively. The results are compared with estimates using the standard Lorentzian model and microscopic calculations. The results reveal a possible contribution of the pygmy dipole resonance or giant quadrupole resonance in the Coulomb breakup reactions of 94 Zr

Self-replicating segregation patterns in horizontally vibrated binary mixture of granules

Abstract Fluidized granular mixtures of various particle sizes exhibit intriguing patterns as different species segregate and condense. However, understanding the segregation dynamics is hindered by the inability to directly observe the time evolution of the internal structure. We discover self-replicating bands within a quasi-2D container subjected to horizontal agitation, resulting in steady surface waves. Through direct observation of surface flow and evolving internal structures, we reveal the crucial role of coupling among segregation, surface flow, and hysteresis in granular fluidity. We develop Bonhoeffer-van der Pol type equations grounded in experimental observations, reproducing complex band dynamics, such as replication, oscillation, and breathing. It suggests the similarity between pattern formation in granular segregation and that in reaction–diffusion systems

Segregation patterns in rotating cylinders determined by the size difference, density ratio, and cylinder diameter

Abstract Granular materials often segregate under mechanical agitation, which differs from the expectation of mixing. It is well known that a bidisperse mixture of granular materials in a partially filled rotating cylinder exhibits alternating bands depending on the combination of the two species. The dynamic angle of repose, which is the angle that a steady avalanche makes with the horizontal, has been considered the dominant parameter that determines the segregated state. However, the previously known angle of repose condition was not always satisfied in different experimental cases. To clarify the experimental conditions, we conducted an exhaustive parameter search with three dimensionless parameters: the particle size difference normalized by the average particle size, the specific density ratio, and the ratio of the cylinder diameter to the average particle size. Additional experiments were conducted to explore the effect of the rotational speed of the cylinder. This systematic approach enabled us to predict the segregated state. Moreover, we discovered that the band width can be effectively scaled by combining these three parameters

Use of analgesics before and after total joint replacement in working-age Japanese patients with knee and hip osteoarthritis: A retrospective database study

Background: Patterns of analgesic use before and after total joint replacement (TJR) in patients with knee/hip osteoarthritis (OA) is not well reported. Methods: This retrospective longitudinal analysis used JMDC claims data of patients who underwent knee/hip replacement surgery from 2010 to 2019. Primary outcome was proportion of patients using analgesics pre-surgery, immediately post-surgery, and in post-surgery period. Factors affecting post-surgery analgesic withdrawal and opioid prescriptions were assessed using logistic regression. Results: Of all (N = 3168) patients, those with knee OA (91.1 %) and hip OA (82.5 %) used analgesics pre-surgery, and 96.1 % with knee OA and 84.9 % with hip OA required analgesics even 3 months post-surgery. NSAIDs were most commonly used pre- and post-surgery in both OA groups. Before surgery, 15.6 % (knee OA) and 13.7 % of patients (hip OA) used weak opioids, and 23.1 % (knee OA) and 10.5 % (hip OA) of patients continued them post-surgery. Strong opioid use was noted in 2.2 % and 1.2 % of patients pre-surgery, and 5.8 % and 3.4 % of patients post-surgery in the knee and hip OA groups, respectively. Using pre-operative oral NSAIDs (odds ratio [OR]:0.56; 95 % confidence interval [CI]:0.44–0.72) and weak opioids (OR:0.58; 95 % CI:0.38–0.87) associated with withdrawal of post-surgery analgesics in patients with hip OA, and using intra-articular hyaluronic acid pre-surgery (OR:0.45; 95 % CI:0.21–0.97) was significant in patients with knee OA. Using weak (OR:4.59; 95 % CI:3.44–6.13) and strong opioids (OR:2.48; 95 % CI:1.01–6.07) pre-surgery associated with post-operative opioid use in patients with hip OA, and weak opioid use was significant in patients with knee OA (OR:7.00; 95 % CI:4.65–10.54). Conclusion: This study reported difference in analgesic use before and after TJR, and that many patients required analgesics even 3 months after TJR surgery in Japan. Pre-operative analgesic use associated with continued use after surgery. Optimal pain management before and immediately after TJR is important to reduce post-operative analgesic use, especially opioids