CO2 laser welding characteristics of Inconel 718, heat treatment effects on microstructures, and tensile/fatigue properties were researched. CO2 laser welding was carried out on 5 mm thick plates ...having two different grain sizes, ASTM #4 and #10. For the fine-grain sized specimens (ASTM #10), the optimum laser welding conditions without defects were 6 kW with 2.5 m/min and 8 kW with 4.0 m/min. However, on the heat-affected zone (HAZ) of large-grained Inconel 718 (ASTM #4), the microfissures were shown at the same welding conditions. Before welding, plates were pre-heat treated at three different conditions: as-received, 955 deg C solution treatment, and 955 deg C solution treatment + aging (955STA). After welding, welds were subjected to four different post-weld heat treatment conditions: as-welded, 955 deg C solution treatment + aging, modified cyclic solution treatment, and direct aging (DA) treatment. In this research, modified cyclic solution heat treatment showed reduction of microfissures and improved tensile and fatigue properties.
High-speed gap measurement in the nano/micrometer range presents unique engineering challenges. A signal conditioner is required for capacitive sensors to amplify, denoise, and restrict the ...bandwidth. In this work, a capacitive sensor was used in combination with a SAW device that serves as a signal conditioner. The proposed system provides 2.75MHz bandwidth through amplitude modulation using the center frequency of the SAW device as a carrier signal and has outstanding signal conditioning capabilities. Construction and characterization of a SAW-based capacitive gap sensor to measure a 200Hz gap frequency are described.
The structure and photoelectrochemical properties of TiO2 films deposited onto SnO2 conducting glass from the ambient hydrolysis of TiCl4 and annealed at temperatures ranging from 100 to 500 °C were ...studied by Raman spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM), intensity-modulated photovoltage spectroscopy (IMVS), and intensity-modulated photocurrent spectroscopy (IMPS) measurements. Analysis of the XRD and Raman spectra shows that TiCl4-produced TiO2 films have the rutile structure, regardless of annealing temperature. The TEM reveals that the rutile TiO2 films consist of rod-shaped particles that grow with increasing annealing temperature. The AM-1.5 short-circuit photocurrent J sc and open-circuit photovoltage V oc of RuLL‘(NCS)2-sensitized (L = 2,2‘-bypyridyl-4,4‘-dicarboxylic acid, L‘ = 2,2‘-bipyridyl-4,4-ditetrabutylammoniumcarboxylate) 4.5 μm thick rutile films increase significantly with annealing temperature, from 1.1 mA/cm2 and 602 mV at 100 °C to 8.7 mA/cm2 and 670 mV at 500 °C. Studies of the incident photon-to-current conversion efficiency (IPCE), the photocurrent−voltage characteristics, the optical appearance, the water content, and the particle size of the films indicate that the increase of both J sc and V oc with annealing temperature is due, in part, to increased dye adsorption resulting from the evaporation of surface water and the improved light-scattering properties of the film associated with the growth of rutile particles. IMVS and IMPS measurements indicate that variations of the charge-collection efficiency of the cell, which increases from 86% for the 300 °C annealed samples to above 99% for the 500 °C annealed samples, have only a minor effect on J sc. Analysis of the time constants at open circuit and short circuit for a given electron injection current suggests that the ratio of free-to-trapped electrons at short circuit decreases and the diffusion coefficient of free electrons increases with annealing temperature. Raman and XRD measurements and other observations indicate that treating transparent nanocrystalline anatase TiO2 electrodes with TiCl4 produces a translucent overlayer of rutile TiO2. The increased film thickness and light-scattering characteristics of the rutile overlayer may explain, in part, the improved IPCE observed for dye-sensitized TiCl4-treated nanocrystalline anatase TiO2 electrodes.
Aim To evaluate the clinical utility of the meniscal width to transverse diameter ratio (L/M ratio) of the lateral meniscus in the diagnosis of incomplete discoid lateral meniscus (IDLM) as compared ...with the arthroscopic diagnosis, meniscal width to tibial diameter ratio (L/T ratio) and conventional lateral meniscus width criteria. Materials and methods This retrospective study sample included 41 patients with IDLM who underwent knee magnetic resonance imaging (MRI) and arthroscopy, as well as 50 controls with normal lateral menisci. MRI examinations were interpreted independently by two radiologists, both of whom were blinded to clinical information and radiological reports. Assessment of meniscal width (L), maximal transverse diameter of the lateral meniscus (M), and transverse diameter of the tibia (T) was carried out on central coronal sections that were observed to pass through the medial collateral ligament. L/M and L/T ratios were calculated. These results were correlated with arthroscopic findings and analysed statistically using categorical regression analysis and non-parametric correlation analysis. Using arthroscopic findings as the standard of reference, sensitivity and specificity were calculated for: (1) 12, 13, 14, and 15 mm meniscal width thresholds; (2) 40%, 50%, 60%, and 70% L/M ratio thresholds; and (3) 15%, 18%, 20%, and 25% L/T ratio thresholds. Results The mean L/M ratio of the IDLM was approximately 67% and was statistically significantly higher than the control (44%). The best diagnostic discrimination was achieved using a threshold of 50%. The mean L/T ratio of the IDLM was approximately 23% and was statistically significant. The best diagnostic discrimination was achieved using a threshold of 18%. The threshold of 13 mm of meniscal width also showed high sensitivity and high specificity. Conclusion The use of the L/M ratio or L/T ratio in combination with meniscal width criteria may be a useful method for evaluating IDLM.
In 2015, the United States Preventive Services Task Force (USPSTF) recommended targeted screening for prediabetes and diabetes (dysglycemia) in adults who are aged 40 to 70 y old and overweight or ...obese. Given increasing prevalence of dysglycemia at younger ages and lower body weight, particularly among racial/ethnic minorities, we sought to determine whether the current screening criteria may fail to identify some high-risk population subgroups.
We investigated the performance of the 2015 USPSTF screening recommendation in detecting dysglycemia among US community health center patients. A retrospective analysis of electronic health record (EHR) data from 50,515 adult primary care patients was conducted. Longitudinal EHR data were collected in six health centers in the Midwest and Southwest. Patients with a first office visit between 2008 and 2010 were identified and followed for up to 3 y through 2013. We excluded patients who had dysglycemia at baseline and those with fewer than two office visits during the follow-up period. The exposure of interest was eligibility for screening according to the 2015 USPSTF criteria. The primary outcome was development of dysglycemia during follow-up, determined by: (1) laboratory results (fasting/2-h postload/random glucose ≥ 100/140/200 mg/dL 5.55/7.77/11.10 mmol/L or hemoglobin A1C ≥ 5.7% 39 mmol/mol); (2) diagnosis codes for prediabetes or type 2 diabetes; or (3) antidiabetic medication order. At baseline, 18,846 (37.3%) participants were aged ≥40 y, 33,537 (66.4%) were overweight or obese, and 39,061 (77.3%) were racial/ethnic minorities (34.6% Black, 33.9% Hispanic/Latino, and 8.7% Other). Overall, 29,946 (59.3%) patients had a glycemic test within 3 y of follow-up, and 8,478 of them developed dysglycemia. Only 12,679 (25.1%) patients were eligible for screening according to the 2015 USPSTF criteria, which demonstrated the following sensitivity and specificity (95% CI): 45.0% (43.9%-46.1%) and 71.9% (71.3%-72.5%), respectively. Racial/ethnic minorities were significantly less likely to be eligible for screening yet had higher odds of developing dysglycemia than whites (odds ratio 95% CI: Blacks 1.24 1.09-1.40; Hispanics 1.46 1.30-1.64; and Other 1.33 1.16-1.54). In addition, the screening criteria had lower sensitivity in all racial/ethnic minority groups compared to whites. Limitations of this study include the ascertainment of dysglycemia only among patients with available test results and findings that may not be generalizable at the population level.
Targeted diabetes screening based on new USPSTF criteria may detect approximately half of adult community health center patients with undiagnosed dysglycemia and proportionately fewer racial/ethnic minorities than whites. Future research is needed to estimate the performance of these screening criteria in population-based samples.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Nonmuscle myosin-IIA (NMHC-IIA) heavy chain phosphorylation has gained recognition as an important feature of myosin-II regulation. In previous work, we showed that phosphorylation on S1943 promotes ...myosin-IIA filament disassembly in vitro and enhances EGF-stimulated lamellipod extension of breast tumor cells. However, the contribution of NMHC-IIA S1943 phosphorylation to the modulation of invasive cellular behavior and metastasis has not been examined. Stable expression of phosphomimetic (S1943E) or non-phosphorylatable (S1943A) NMHC-IIA in breast cancer cells revealed that S1943 phosphorylation enhances invadopodia function, and is critical for matrix degradation in vitro and experimental metastasis in vivo. These studies demonstrate a novel link between NMHC-IIA S1943 phosphorylation, the regulation of extracellular matrix degradation and tumor cell invasion and metastasis.
•pS1943 NMHC-IIA is detected in orthotopic tumors and metastatic lesions.•S1943E NMHC-IIA drives gelatin degradation and MMP9 secretion.•S1943E NMHC-IIA S1943E increases experimental metastasis in vivo.•NMHC-IIA S1943 phosphorylation regulates breast cancer invasion and metastasis.
To investigate the relationship between cognitive performance and cognitive health appraisals across non-Hispanic White, non-Hispanic Black, and Hispanic older adults in the United States and to ...explore within-group variations by examining interactions between cognitive performance and background and health variables.
The sample (N = 3,099) included 2,260 non-Hispanic White, 498 non-Hispanic Black, and 341 Hispanic adults aged 65 or older, from the 2016-2017 Harmonized Cognitive Assessment Protocol. Regression models of cognitive health appraisals, indicated by self-rated cognitive health, were examined in the entire sample and in racial and ethnic subgroups to test direct and interactive effects of cognitive performance, indicated by the Mini-Mental State Examination (MMSE).
The regression model for the entire sample showed direct effects of cognitive performance and race/ethnicity on cognitive health appraisals, as well as a significant interaction between cognitive performance and being non-Hispanic Black. Cognitive performance and cognitive health appraisals were positively associated in non-Hispanic Whites but not significantly associated in non-Hispanic Blacks. Our subsequent analysis within each racial/ethnic group showed that the effect of cognitive performance in non-Hispanic Blacks and Hispanics became either reversed or nonsignificant when background and health variables were considered. Modification by age or chronic medical conditions in each racial and ethnic group was also observed.
Overall, these findings suggest that perceptions and appraisals of cognitive health vary by race and ethnicity and hold implications for how these differences should be considered in research and practice with diverse groups of older adults.
Celotno besedilo
Dostopno za:
BFBNIB, DOBA, IZUM, KILJ, NUK, OILJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK, VSZLJ
The nature of light as an electromagnetic wave with transverse components has been confirmed using optical polarizers, which are sensitive to the orientation of the electric field. Recent advances in ...nanoscale optical technologies demand their magnetic counterpart, which can sense the orientation of the optical magnetic field. Here we report that subwavelength metallic apertures on infinite plane predominantly sense the magnetic field of light, establishing the orientation of the magnetic component of light as a separate entity from its electric counterpart. A subwavelength aperture combined with a tapered optical fibre probe can also serve as a nanoscale polarization analyser for the optical magnetic field, analogous to a nanoparticle sensing the local electric polarization. As proof of its functionality, we demonstrate the measurement of a magnetic field orientation that is parallel to the electric field, as well as a circularly polarized magnetic field in the presence of a linearly polarized electric field.
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