Effects of education on low-phosphate diet and phosphate binder intake to control serum phosphate among maintenance hemodialysis patients: A randomized controlled trial.

Background:For phosphate control, patient education is essential due to the limited clearance of phosphate by dialysis. However, well-designed randomized controlled trials about dietary and phosphate binder education have been scarce. Methods:We enrolled maintenance hemodialysis patients and randomized them into an education group (n = 48) or a control group (n = 22). We assessed the patients' drug compliance and their knowledge about the phosphate binder using a questionnaire. Results:The primary goal was to increase the number of patients who reached a calcium-phosphorus product of lower than 55. In the education group, 36 (75.0%) patients achieved the primary goal, as compared with 16 (72.7%) in the control group (P = 0.430). The education increased the proportion of patients who properly took the phosphate binder (22.9% vs. 3.5%, P = 0.087), but not to statistical significance. Education did not affect the amount of dietary phosphate intake per body weight (education vs. control: -1.18 ± 3.54 vs. -0.88 ± 2.04 mg/kg, P = 0.851). However, the dietary phosphate-to-protein ratio tended to be lower in the education group (-0.64 ± 2.04 vs. 0.65 ± 3.55, P = 0.193). The education on phosphate restriction affected neither the Patient-Generated Subjective Global Assessment score (0.17 ± 4.58 vs. -0.86 ± 3.86, P = 0.363) nor the level of dietary protein intake (-0.03 ± 0.33 vs. -0.09 ± 0.18, P = 0.569). Conclusion:Education did not affect the calcium-phosphate product. Education on the proper timing of phosphate binder intake and the dietary phosphate-to-protein ratio showed marginal efficacy

Tailored polyethylene glycol grafting on porous nanoparticles for enhanced targeting and intracellular siRNA delivery

Surface functionalization of nanoparticles with polyethylene glycol (PEG) has been widely demonstrated as an anti-opsonization strategy to reduce protein corona formation which is one of the major concerns affecting target receptor recognition. However, excessive surface passivation with PEG can lead to the strong inhibition of cellular uptake and less efficient binding to target receptors, resulting in reduced potential of targeted delivery. To improve specific cell targeting while reducing the nonspecific protein adsorption, a secondary packaging of the nanoparticles with shorter PEG chains, making the targeting ligands densely stretched out for enhanced molecular recognition is demonstrated. Particularly, we report the tailored surface functionalization of the porous nanoparticles that require the stealth shielding onto the open-pore region. This study shows that, in addition to the surface chemistry, the conformation of the PEG layers controls the cellular interaction of nanoparticles. Since the distance between neighboring PEG chains determines the structural conformation of the grafted PEG molecules, tailored PEG combinations can efficiently resist the adsorption of serum proteins onto the pores by transitioning the conformation of the PEG chains, thus significantly enhance the targeting efficiency (>5-fold). The stretched brush PEG conformation with secondary packaging of shorter PEG chains could be a promising anti-opsonization and active targeting strategy for efficient intracellular delivery of nanoparticles

Evaluation of the anti-oxidative and ROS scavenging properties of biomaterials coated with epigallocatechin gallate for tissue engineering

In tissue engineering, excessively generated reactive oxygen species (ROS) during biomaterial implantation or cell transplantation is a one of major causes of diminishing therapeutic effects. In this study, we prepared biomaterial surfaces coated with antioxidant epigallocatechin gallate (EGCG) and metal ions, and evaluated their anti-oxidative and ROS scavenging properties. We revealed that EGCG-coating on polycaprolactone (PCL) film surface increased hydrophilicity and anti-oxidative properties as a function of total phenol content (TPC) potentially due to the increase in phenolic -OH and pi-electrons from structural maintenance and directly removed the hydrogen peroxide (H2O2) by resonance-stabilization. Furthermore, EGCG-coated PCL film increased attachment, spreading area, and viability of human adipose-derived stem cells (hADSCs) against H2O2 treatment while stimulated the cellular signaling to reduce apoptotic gene and enhance anti-oxidative enzyme expression. Further, we applied EGCG coating on the surface of poly-L-lactic acid (PLLA) fibers. Spheroids incorporating EGCG-coated PLLA fibers were able to maintain their shape and showed improved viability and anti-oxidative activities in response to H2O2-induced oxidative stress than control spheroids. Therefore, metal-phenolic network (MPN) coating of EGCG is a suitable method to impart the anti-oxidative properties to biomaterials by evaluating the structural properties and biological effects. Statement of Significance This manuscript describes an antioxidant coating for biomaterials to control reactive oxygen species (ROS). Antioxidant epigallocatechin gallate (EGCG) was coated on the PCL film surface via metal-phenolic network (MPN). We revealed that the phenolic functional groups of EGCG are structurally maintained as confirmed by quantitative reducing power, radical scavenging assays. EGCG coating not only removed ROS directly, but also is involved in cell signaling to enhance the anti-apoptotic gene, anti-oxidative enzyme expression. Furthermore, human adipose-derived stem cells (hADSCs) spheroid produced by self-assembly with EGCG-coated poly-L-lactic aicd (PLLA) fibers showed anti-oxidative properties from inside of spheroids. Thus, our evaluation of the anti-oxidative properties of EGCG coating can be applied to various tissue engineering applications. (C) 2021 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved

Enhanced superconductivity in aluminum-based hyperbolic metamaterials

One of the most important goals of condensed matter physics is materials by design, i.e. the ability to reliably predict and design materials with a set of desired properties. A striking example is the deterministic enhancement of the superconducting properties of materials. Recent experiments have demonstrated that the metamaterial approach is capable of achieving this goal, such as tripling the critical temperature T-C in Al-Al2O3 epsilon near zero (ENZ) core-shell metamaterial superconductors. Here, we demonstrate that an Al/Al2O3 hyperbolic metamaterial geometry is capable of a similar T-C enhancement, while having superior transport and magnetic properties compared to the core-shell metamaterial superconductors

Observation of the out-of-plane magnetization in a mesoscopic ferromagnetic structure superjacent to a superconductor

The geometry of magnetic flux penetration in a high temperature superconductor at a buried interface was imaged using element-specific x-ray excited luminescence. We performed low temperature observation of the flux penetration in YBa2Cu3O7–δ (YBCO) at a buried interface by imaging of the perpendicular magnetization component in square Permalloy (Py) mesostructures patterned superjacent to a YBCO film. Element specific imaging below the critical temperature of YBCO reveals a cross-like geometry of the perpendicular magnetization component which is decorated by regions of alternating out-of-plane magnetization at the edges of the patterned Py structures. The cross structure can be attributed to the geometry of flux penetration originating from the superconductor and is reproduced using micromagnetic simulations. Our experimental method opens up possibilities for the investigation of flux penetration in superconductors at the nanoscale

Construction of 3-D cellular multi-layers with extracellular matrix assembly using magnatic nanoparticles

Construction of 3-dimensional (3-D) engineered tissue is increasingly being investigated for use in drug discovery and regenerative medicine. Here, we developed multi-layered 3-D cellular assembly by using magnetic nanoparticles (MNP) isolated from Magnetospirillum sp. AMB-1 magnetotactic bacteria. Magnetized human dermal fibroblasts (HDFBs) were prepared by treatment with the MNP, induced to form 3-D assembly under a magnetic field. Analyses including LIVE/DEAD assay, transmission electron microscopy revealed that the MNP were internalized via clathrin-mediated endocytosis without cytotoxicity. The magnetized HDFBs could build 3-D structure as a function of seeding density. When the highest seeding density (5 × 105 cells/mm2 was used, the thickness of assembly was 4190 ± 169 μm, with approximately 93±16 cell layers being formed. Immunofluorescence staining confirmed homogeneous distribution of ECM and junction proteins throughout the 3-D assembly. Real-time PCR analysis showed decrease in expression levels of collagen types I and IV but increase in that of connexin 43 in the 3-D assembly compared with the 2-D culture. Finally, we demonstrated that the discernible layers can be formed hierarchically by serial assembly. In conclusion, our study showed that a multi-layered structure can be easily prepared using magnetically-assisted cellular assembly with highlighting cell-cell and cell-ECM communication.OAIID:RECH_ACHV_DSTSH_NO:T201623722RECH_ACHV_FG:RR00200001ADJUST_YN:EMP_ID:A002014CITE_RATE:3.929FILENAME:7. (2016.10) Construction of 3-D Cellular Multi-Layers with.pdfDEPT_NM:화학생물공학부EMAIL:[email protected]_YN:YFILEURL:https://srnd.snu.ac.kr/eXrepEIR/fws/file/a5981ae9-bf9b-4b44-bd34-9e96bc984798/linkCONFIRM:

MFT-MAC: A Duty-Cycle MAC Protocol Using Multiframe Transmission for Wireless Sensor Networks

In many sensor network applications, energy efficiency and latency are major design criteria because battery-operated sensor nodes limit network lifetime. In this paper, we propose a new contention-based duty-cycle MAC protocol using a synchronized approach for use in wireless sensor networks. In the proposed MFT-MAC protocol, we use a control frame that considers the number of DATA frames to be transmitted to the next node in order to improve the energy efficiency and reduce the end-to-end delay. During the SLEEP period, each node transmits multiple DATA frames to the next node through the use of the control frame. The performance of the proposed MAC protocol is confirmed through the use of NS-2 simulator

Comparison of estimated glomerular filtration rate equations at the time of hemodialysis initiation

Background: Estimated glomerular filtration rate (eGFR) is one of the most important guidelines in deciding the optimal timing of dialysis initiation. In the present study, we calculated the eGFR at the time of hemodialysis (HD) initiation using 5 commonly used equations to relate them with clinical and laboratory characteristics of the patients and to evaluate which of these equations best define the eGFR at HD initiation. Methods: We retrospectively analyzed 409 end-stage renal disease patients who were newly started on HD treatment in our institution. The eGFR was calculated using the Cockcroft–Gault equation, the Cockcroft–Gault equation corrected for body surface area, the Modification of Diet in Renal Disease (MDRD) equation, the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation, and the Nankivell equation. Results: The mean eGFRs at HD start were significantly different across the equations. The mean eGFR was 7.8 mL/min for the corrected Cockcroft–Gault equation, 7.7 mL/min for the Cockcroft–Gault equation, 6.2 mL/min/1.73 m2 for the MDRD equation, and 5.6 mL/min/1.73 m2 for the CKD-EPI equation. The corrected Cockcroft–Gault, the MDRD, and the CKD-EPI equations were well correlated with all CKD-specific complications including hypertension, anemia, hyperkalemia, metabolic acidosis, hypocalcemia, hyperphosphatemia, and hyperparathyroidism. The mean eGFR calculated by the corrected Cockcroft–Gault equation showed the lowest coefficient of variation among all the equations. Conclusions: The eGFR at HD initiation are significantly different according to the used eGFR equations, and the corrected Cockcroft–Gault equation may be the best in defining the eGFR at HD initiation