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Research has been conducted on the ligand-conjugated nanocrystals. The use of these ligands in targeting cell surface receptors, transporters and ion channels has been investigated via the interactions of serotonin-labeled CdSe nanocrystals with the antidepressant-sensitive transporters expressed in HeLa and HEK-293 cells and the results are described.

Objective: Ultrasound is one of the most commonly used imaging modalities, though some populations face barriers in accessing ultrasound services, potentially resulting in disparities in utilization. The objective of this study was to assess the association between sociodemographic and geographic factors and non-obstetrical ultrasound utilization in the province of Saskatchewan, Canada. Methods: All non-obstetrical ultrasound exams performed from 2014 to 2018 in Saskatchewan, Canada were retrospectively identified from province-wide databases. Univariate and multivariate Poisson regression analyses were performed to assess the association between ultrasound utilization and sex, age, First Nations status, Charlson Comorbidity Index, urban vs. rural residence, geographic remoteness, and neighborhood income. Results: A total of 1,324,846 individuals (5,857,044 person-years) were included in the analysis. Female sex (adjusted incidence rate ratio [aIRR], 2.20; 95% confidence interval [CI], 2.19-2.22), age (aIRR, 4.97; 95% CI, 4.90-5.05 for ≥57 years vs. <11 years), comorbidities (aIRR, 4.36 for Charlson Comorbidity Index >10 vs. 0; 95% CI, 3.78-5.03), and higher neighborhood income (aIRR, 1.04; 95% CI, 1.02-1.05 for highest vs. lowest quintile) were associated with higher rates of ultrasound utilization. Individuals who were status First Nations (aIRR, 0.91; 95% CI, 0.90-0.92) or resided in geographically remote areas (aIRR, 0.87 for most vs. least remote; 95% CI, 0.83-0.91) had lower rates of ultrasound utilization. Individuals who lived in a rural area also had lower rates of ultrasound utilization (aIRR, 0.93; 95% CI, 0.92-0.94). Conclusion: Substantial disparities exist in non-obstetrical ultrasound utilization among individuals in low-income neighborhoods, status First Nations individuals, and individuals in rural and remote communities. [ABSTRACT FROM AUTHOR]

Rationale and Objectives: Obstetrical ultrasound imaging is an important part of prenatal care, though not all patients have readily available access to ultrasound services. This study aimed to assess the association between sociodemographic and geographic factors and (1) having a second trimester complete obstetrical ultrasound and (2) overall obstetrical ultrasound utilization.Methods: All pregnancies and obstetrical ultrasound exams billed from 2014-2018 in Saskatchewan, Canada were identified from province-wide databases. Generalized estimating equation (GEE) models with binomial and Poisson distributions were used to identify factors associated with having a second trimester ultrasound and overall obstetrical ultrasound utilization, respectively.Results: 80,536 pregnancies from 57,881 individuals were included. Of 57,186 pregnancies carried to ≥23 weeks, a second trimester ultrasound was performed in 50,180 (87.7%). Patients living in rural areas (adjusted odds ratio [aOR], 0.70; 95% confidence interval [CI], 0.63-0.77; p <0.0001), remote areas (aOR, 0.35 for greatest vs. least remoteness level; 95% CI, 0.32-0.39; p <0.0001), and status First Nations individuals (aOR, 0.50; 95% CI, 0.46-0.53; p <0.0001) were less likely to have a second trimester ultrasound. Patients living in higher income neighbourhoods (aOR, 1.86 for highest vs. lowest quintile; 95% CI, 1.62-2.13; p <0.0001) were more likely to have a second trimester ultrasound. GEE Poisson regression analysis demonstrated these same factors, except rural residence, were associated with overall obstetrical ultrasound utilization.Conclusion: Substantial disparities in obstetrical ultrasound utilization exist among patients in remote geographic areas, Indigenous peoples, and patients in low income neighbourhoods. Addressing barriers which these demographic groups face in accessing ultrasound imaging is critical to ensure health equity. [ABSTRACT FROM AUTHOR]

Introduction: Chronic kidney disease-mineral and bone disorders (CKD-MBD) are prevalent in patients undergoing maintenance dialysis. Yet, there are limited and mixed evidence on the effects of different dialysis modalities involving longer treatment times or higher frequencies on CKD-MBD markers. Methods: This cohort study used data from 132,523 incident dialysis patients treated with any of the following modalities: conventional thrice-weekly in-center hemodialysis, nocturnal in-center hemodialysis (NICHD), home hemodialysis (HHD), or peritoneal dialysis (PD) from 2007 to 2011. We used marginal structural models fitted with inverse probability weights to adjust for fixed and time-varying confounding and informative censoring. We estimated the average effects of treatments with different dialysis modalities on time-varying serum concentrations of CKD-MBD markers: albumin-corrected calcium, phosphate, parathyroid hormone (PTH), and alkaline phosphatase (ALP) using pooled linear regression. Results: Most of the cohort were exclusively treated with conventional in-center hemodialysis, while few were ever treated with NICHD or HHD. At the baseline, PD patients had the lowest mean and median values of PTH, while NICHD patients had the highest median values. During follow-up, compared to hemodialysis patients, patients treated with NICHD had lower mean serum PTH (19.8 pg/mL [95% confidence interval: 2.8, 36.8] lower), whereas PD and HHD patients had higher mean PTH (39.7 pg/mL [31.6, 47.8] and 51.2 pg/mL [33.0, 69.3] higher, respectively). Compared to hemodialysis patients, phosphate levels were lower for patients treated with NICHD (0.44 mg/dL [0.37, 0.52] lower), PD (0.15 mg/dL [0.12, 0.19] lower), or HHD (0.33 mg/dL [0.27, 0.40] lower). There were no clinically meaningful associations between dialysis modalities and concentrations of calcium or ALP. Conclusion: In incident dialysis patients, compared to treatment with conventional in-center hemodialysis, treatments with other dialysis modalities with longer treatment times or higher frequency were associated with different patterns of serum phosphate and PTH. Given the recent growth in the use of dialysis modalities other than hemodialysis, the associations between the treatment and the CKD-MBD markers warrant additional study. [ABSTRACT FROM AUTHOR]

Piezoelectric nanogenerator (PENG) is a leading-edge mechanical energy harvesting device used in portable power supply and self-powered sensor systems. Advanced 3D printers have been recently used to create 3D printed (3DP) PENGs. This has facilitated the rapid fabrication of PENGs and their integration into wearable electronics, biomedical systems, and internet of things devices. However, researchers face several critical challenges in developing robust 3DP-PENGs that can produce adequate electrical energy for self-powered systems. Therefore, this review on 3DP-PENGs is conducted to highlight their recent developments and challenges. This paper presents the latest 3D-printed piezoelectric nanogenerators in terms of their materials selection and functionalization, design and architecture formation, and applications including pressure sensors, flow sensors, microphones, and implants. Finally, crucial challenges and optimization strategies that considerably impact the output performance of 3DP-PENGs, along with a roadmap for their future enhancement are given. It is envisioned that this work will help reduce the gap between 3D printing and PENG technologies and accelerate the research and development of 3DP-PENGs. [ABSTRACT FROM AUTHOR]

In this paper we present theoretical analysis and experimental results on the dynamical behavior of a bistable microelectro-mechanical systems (MEMS) oscillator, demonstrate the existence of a strange attractor in the MEMS device, and perform model verification using the experimental data. Secure communication schemes based on synchronized chaos are also applied to the device and successfully performed in the simulation.

Using a combination of electrostatic actuators, we present a method to independently tune the linear and nonlinear stiffness coefficients of a uniaxial micromechanical device. To demonstrate the method's capability, we investigated the tuning of an oscillator with linear and cubic restoring forces. We successfully tuned the cubic stiffness from 0.31x[10.sup.11] to -5.1x[10.sup.11] N/[m.sup.3] without affecting the resonant frequency or the linear stiffness. Numerical results are presented which characterize the actuators and indicate important design parameters. Finally, issues such as actuator design, quadratic stiffness, and stability are discussed. Index Terms - Actuators, capacitance, electrostatic, stiffness, tuning.