The effect of Si and Sc on the evolution of the precipitates during aging in Al4.0Cu0.5 Mg alloys was investigated by means of microhardness tests and transmission electron microscope. The results ...show that Si can significantly refine the size of θ′ phases, because addition of Si introduces a considerable amount of small, uniformly dispersed Al–Cu–Mg–Si (Q) quaternary phases, which provides nucleation sites for the θ′ phases. Sc atoms segregate at the interfaces between the matrix and the θ′-Al2Cu precipitates in AlCuMgSiSc alloy. The segregation of Sc atoms inhibits the growth of the θ′ phases and improves the thermal stability of the θ′ phases. At the same time, the segregation of Sc atoms in Q phases restrains the coarsening of the Q phases, which also contributes to the thermal stability of the θ′ phases. The co-addition of Si and Sc thus leads to a combination of high strength and high thermal stability of the Al–Cu–Mg–Si-Sc alloy.
Abstract
The Vera C. Rubin Observatory is expected to start the Legacy Survey of Space and Time (LSST) in early to mid-2025. This multiband wide-field synoptic survey will transform our view of the ...solar system, with the discovery and monitoring of over five million small bodies. The final survey strategy chosen for LSST has direct implications on the discoverability and characterization of solar system minor planets and passing interstellar objects. Creating an inventory of the solar system is one of the four main LSST science drivers. The LSST observing cadence is a complex optimization problem that must balance the priorities and needs of all the key LSST science areas. To design the best LSST survey strategy, a series of operation simulations using the Rubin Observatory scheduler have been generated to explore the various options for tuning observing parameters and prioritizations. We explore the impact of the various simulated LSST observing strategies on studying the solar system’s small body reservoirs. We examine what are the best observing scenarios and review what are the important considerations for maximizing LSST solar system science. In general, most of the LSST cadence simulations produce ±5% or less variations in our chosen key metrics, but a subset of the simulations significantly hinder science returns with much larger losses in the discovery and light-curve metrics.
Global estimates of prevalence, deaths, and disability-adjusted life years (DALYs) from the Global Burden of Diseases, Injuries, and Risk Factors Study 2019 were examined for metabolic diseases (type ...2 diabetes mellitus T2DM, hypertension, and non-alcoholic fatty liver disease NAFLD). For metabolic risk factors (hyperlipidemia and obesity), estimates were limited to mortality and DALYs. From 2000 to 2019, prevalence rates increased for all metabolic diseases, with the greatest increase in high socio-demographic index (SDI) countries. Mortality rates decreased over time in hyperlipidemia, hypertension, and NAFLD, but not in T2DM and obesity. The highest mortality was found in the World Health Organization Eastern Mediterranean region, and low to low-middle SDI countries. The global prevalence of metabolic diseases has risen over the past two decades regardless of SDI. Urgent attention is needed to address the unchanging mortality rates attributed to metabolic disease and the entrenched sex-regional-socioeconomic disparities in mortality.
Display omitted
•Global estimates from the GBD Study 2019 were examined for metabolic diseases•Mortality rates decreased over time for hyperlipidemia, hypertension, and NAFLD•Mortality rates remained unchanged over time for diabetes and obesity•The highest mortality was in the Eastern Mediterranean and low-income countries
Global estimates from the GBD Study 2019 reveal decreasing mortality rates between 2000 and 2019 for hyperlipidemia, hypertension, and NAFLD, but not for T2DM and obesity. The highest mortality rate due to metabolic disease was found in the Eastern Mediterranean, and in low- to low-middle-income countries. Urgent attention is needed to address high and unchanging mortality rates as well as entrenched sex-regional-socioeconomic disparities in death related to metabolic disease.
To systematically compare epithelial-off standard (SCXL) to accelerated corneal collagen cross-linking (ACXL) for the treatment of keratoconus.
PubMed, Embase, the Cochrane Library, and the US trial ...registry were searched for trials comparing SCXL and ACXL for keratoconus up to October 2017. Standardized mean differences (SMDs) with 95% confidence intervals (CIs) were calculated. Primary outcomes were changes in uncorrected distance visual acuity, maximum keratometry (Kmax), and mean keratometry (mean K). Secondary outcomes were changes in corrected distance visual acuity, mean refractive spherical equivalent, central corneal thickness (CCT), and endothelial cell density (ECD).
Eleven trials were included. For primary outcomes, SCXL showed a greater reduction in Kmax (SMD 0.32; 95% CI 0.16, 0.48) than ACXL. For secondary outcomes, the decrease in CCT (SMD 0.32; 95% CI 0.03, 0.61) and ECD (SMD 0.26; 95% CI 0.06, 0.46) was less with ACXL than with SCXL. For the other outcomes, there were no statistically significant differences.
SCXL has a greater effect in terms of reduction in Kmax than ACXL, while ACXL induces less reduction in CCT and ECD than SCXL. Further well-designed randomized controlled trials comparing ACXL and SCXL are indicated.
In this work, the interdiffusion coefficient and atomic mobility for the fcc Ag-Cu-Mg phase at 1073 K were investigated by combining diffusion couple experiments and calculations. Based on the ...experimental composition profiles, the diffusion coefficients at the intersections of the diffusion paths were calculated using the Matano-Kirkaldy method. Using the thermodynamic descriptions available in the literature, the atomic mobilities for the fcc Ag-Cu-Mg phase were automatically optimized by numerical inverse method integrated with the CALTPP (CALculation of ThermoPhysical Properties) program. Moreover, the obtained atomic mobilities were confirmed to be reliable by good agreements between the model-simulated and the measured composition profiles. In addition, three-dimensional surfaces were presented for the interdiffusion coefficient, activation energy, and frequency factor. The presently obtained atomic mobilities can be incorporated into the diffusion database for Ag-based alloys, which can contribute to microstructure simulation and materials design.
Glycogen synthase kinase 3 beta (GSK3β) is highly inactivated in epithelial cancers and is known to inhibit tumor migration and invasion. The zinc-finger-containing transcriptional repressor, Slug, ...represses E-cadherin transcription and enhances epithelial-mesenchymal transition (EMT). In this study, we find that the GSK3β-pSer9 level is associated with the expression of Slug in non-small cell lung cancer. GSK3β-mediated phosphorylation of Slug facilitates Slug protein turnover. Proteomic analysis reveals that the carboxyl terminus of Hsc70-interacting protein (CHIP) interacts with wild-type Slug (wtSlug). Knockdown of CHIP stabilizes the wtSlug protein and reduces Slug ubiquitylation and degradation. In contrast, nonphosphorylatable Slug-4SA is not degraded by CHIP. The accumulation of nondegradable Slug may further lead to the repression of E-cadherin expression and promote cancer cell migration, invasion and metastasis. Our findings provide evidence of a de novo GSK3β-CHIP-Slug pathway that may be involved in the progression of metastasis in lung cancer.
Summary Objective To study the effect of intra-articular injection of meloxicam (Mobic) on the development of osteoarthritis (OA) in rats and examine concomitant changes in nociceptive behavior and ...the expression of mitogen-activated protein kinases (MAPKs) in articular cartilage chondrocytes. Methods OA was induced in Wistar rats by right anterior cruciate ligament transection (ACLT); the left knee was not treated. The OA + meloxicam (1.0 mg) group was injected intra-articularly in the ACLT knee with 1.0 mg of meloxicam once a week for 5 consecutive weeks starting 5 weeks after ACLT. The OA + meloxicam (0.25 mg) group was treated similarly with 0.25 mg meloxicam. The sham group underwent arthrotomy only and received vehicle of 0.1 mL sterile 0.9% saline injections, whereas the naive rats in meloxicam-only groups were treated similarly with 1.0- and 0.25-mg meloxicam. Nociception was measured as secondary mechanical allodynia and hind paw weight-bearing distribution at before (pre-) and 5, 10, 15, and 20 weeks post-ACLT. Histopathology of the cartilage and synovia was examined 20 weeks after ACLT. Immunohistochemical analysis was performed to examine the effect of meloxicam on MAPKs (p38, c-Jun N-terminal kinase (JNK), and extracellular signal-regulated kinase (ERK)) expression in the articular cartilage chondrocytes. Results OA rats receiving intra-articular meloxicam treatment showed significantly less cartilage degeneration and synovitis than saline-treated controls. Nociception were improved in the OA + meloxicam groups compared with the OA group. Moreover, meloxicam attenuated p38 and JNK but enhanced ERK expression in OA-affected cartilage. Conclusions Intra-articular injection of meloxicam (1) attenuates the development of OA, (2) concomitantly reduces nociception, and (3) modulates chondrocyte metabolism, possibly through inhibition of cellular p38 and JNK, but enhances ERK expression.
In industrial robots, a performance issue is backlash, which is the clearance between mating gears of its joints. Over time, backlash grows through wear and tear, causing inaccuracies in robot ...positioning. Current methods in backlash detection are performed in low-speed and laboratory settings, or require offline diagnostics. These methods are impractical in actual manufacturing environments, where industrial robots operate continuously at high speeds. Other methods require additional sensors unavailable in typical industrial robots. In this article, we present an online method to quantify backlash and predict the remaining useful life (RUL) in an industrial robot performing cyclic production tasks, using only standard available sensors. To achieve the robot's target position, the input torque oscillates; these oscillations grow as the backlash becomes more severe. We modeled the oscillations as an unknown input, and used an unknown input observer to estimate them and detect/quantify the backlash. Then, a health indicator (HI) is plotted over time and a failure threshold is set based on historical data. Finally, an exponential degradation model is used to predict the RUL of the robot joint. The UIO successfully detected and quantified the backlash through the HI. The degradation model gave a good estimate of the RUL with an accuracy of 20 days after 250 days of operation.
PDF
