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Scientific Reports Jan 2022Cardiovascular and deep breathing diseases can be detected by measuring human signals such as heart rate, respiration, and blood pressure, which are important...
Cardiovascular and deep breathing diseases can be detected by measuring human signals such as heart rate, respiration, and blood pressure, which are important physiological parameters for accessing the state of the body. However, conventionally, heart and respiration rates are monitored using different sensors, which is cumbersome and can further increase the psychological burden on patients. To address these issues, this report proposes a sensor consisting of two stacked elements that can simultaneously measure heart and respiration rates. The two signals received can be expressed separately as heart and respiration rates after signal processing. The two stacked elements are composed of polyvinylidene fluoride thin film bonded to a polydimethylsiloxane substrate. One element (element 1) measures movement related to the heart, and the other (element 2) measures movement related to breathing. Elements 1 and 2 were experimentally observed to have sensitivities of 0.163 V/N and 0.209 V/N, respectively. In addition, the proposed system was compared with a commercial digital heart rate and respiration rate measurement instrument and was verified to be effective for simultaneous measurement of human vital signals with multiple sensors. In addition, the proposed system is flexible, lightweight, and inexpensive, making it convenient and economical.
Topics: Fluorocarbon Polymers; Polyvinyls
PubMed: 35087222
DOI: 10.1038/s41598-022-05622-z -
Clinical Oral Investigations Jul 2023Although a new super-quick setting polyether impression material has been commercially recently introduced, its properties have not been yet reported. Thus, it was the...
OBJECTIVES
Although a new super-quick setting polyether impression material has been commercially recently introduced, its properties have not been yet reported. Thus, it was the aim of this study to assess the dimensional stability, tear strength, and elastic recovery of the new material and to compare it with another commonly used polyether and polyvinyl siloxane.
MATERIALS AND METHODS
A new super-quick set polyether, a regular set polyether and a polyvinylsiloxane (PVS) impression material have been used in the study. Dimensional changes were measured using a modified mold as per ISO 4823:2000 after 1 h and 7 days. Tear strength was evaluated by subjecting specimens to tension until failure with a crosshead speed of 250 mm/min. Elastic recovery was measured by deforming specimens using a materials testing machine to a height of 16 mm (20% strain). The change in length (ΔL) was measured afterwards and elastic recovery was calculated in percentages.
RESULTS
Dimensional changes of the super quick and regular set polyether were comparable in both the vertical and horizontal dimensions after 24 h and 7 days. All the tested materials showed dimensional change values far below the maximum accepted ISO requirement (1.5%). The super quick setting polyether showed significantly improved tear strength (4.9 N/mm) in comparison to the regular set polyether (3.5 N/mm) and similar to PVS (5.2 N/mm). The elastic recovery of PVS (99.6%) was the highest among all the groups.
CONCLUSIONS AND CLINICAL RELEVANCE
The newly available super-fast set polyether offers a great potential for a reduced chair side time and comfort for both, the patient and the dentist. Super quick polyether showed as well improved tear strength, which is considered one of the shortcomings of the regular set polyether. In addition, the new polyether was as accurate as the regular set polyether and with good elastic recovery.
Topics: Humans; Dental Impression Materials; Siloxanes; Polyvinyls; Materials Testing
PubMed: 37017760
DOI: 10.1007/s00784-023-04982-8 -
Small (Weinheim An Der Bergstrasse,... Dec 2021Repetitious mechanical stress or external mechanical impact can damage wearable electronic devices, leading to serious degradations in their electrical performances,...
Repetitious mechanical stress or external mechanical impact can damage wearable electronic devices, leading to serious degradations in their electrical performances, which limits their applications. Because self-healing would be an excellent solution to the above-mentioned issue, this paper presents a self-healable memory device based on a novel nanocomposite layer consisting of a polyvinyl alcohol matrix and imidazole-modified graphene quantum dots. The device exhibits reliable electrical performance over 600 cycles, and the electrical properties of the device are maintained without any failure under this bending stress. Further, it is confirmed that the damaged device can recover its original electric characteristics after the self-healing process. It is believed that such outstanding results will lead the way to the realization of future wearable electronic systems.
Topics: Electric Conductivity; Graphite; Imidazoles; Nanocomposites; Polyvinyl Alcohol
PubMed: 34622562
DOI: 10.1002/smll.202102772 -
Journal of Visualized Experiments : JoVE Sep 2020A western blot (also known as an immunoblot) is a canonical method for biomedical research. It is commonly used to determine the relative size and abundance of specific...
A western blot (also known as an immunoblot) is a canonical method for biomedical research. It is commonly used to determine the relative size and abundance of specific proteins as well as post-translational protein modifications. This technique has a rich history and remains in widespread use due to its simplicity. However, the western blotting procedure famously takes hours, even days, to complete, with a critical bottleneck being the long incubation times that limit its throughput. These incubation steps are required due to the slow diffusion of antibodies from the bulk solution to the immobilized antigens on the membrane: the antibody concentration near the membrane is much lower than the bulk concentration. Here, we present an innovation that dramatically reduces these incubation intervals by improving antigen binding via cyclic draining and replenishing (CDR) of the antibody solution. We also utilized an immunoreaction enhancing technology to preserve the sensitivity of the assay. A combination of the CDR method with a commercial immunoreaction enhancing agent boosted the output signal and substantially reduced the antibody incubation time. The resulting ultra-high-speed western blot can be accomplished in 20 minutes without any loss in sensitivity. This method can be applied to western blots using both chemiluminescent and fluorescent detection. This simple protocol allows researchers to better explore the analysis of protein expression in many samples.
Topics: Antibodies; Blotting, Western; Electrophoresis, Polyacrylamide Gel; HEK293 Cells; Humans; Image Processing, Computer-Assisted; Membranes, Artificial; Polyvinyls
PubMed: 33044451
DOI: 10.3791/61657 -
The Science of the Total Environment May 2023In the present study, the migration of plasticizers from modeled and commercial polyvinyl chloride (mPVC and cPVC, respectively) to poly(dimethylsiloxane) via artificial...
In the present study, the migration of plasticizers from modeled and commercial polyvinyl chloride (mPVC and cPVC, respectively) to poly(dimethylsiloxane) via artificial sebum was assessed to mimic the dermal migration of plasticizers. In addition, the various factors affecting migration of phthalic acid esters (PAEs) from diverse PVC products were investigated. The migrated mass and migration ratio of PAEs increased but the migration rate decreased over time. The migration rate increased with sebum mass, contact time, and temperature but decreased under higher pressure. Low-molecular-weight PAEs (dimethyl phthalate and diethyl phthalate) migrated in higher amounts than high-molecular-weight PAEs (dicyclohexyl phthalate [DCHP] and diisononyl phthalate [DINP]). Diffusion of all PAEs in mPVC increased with temperature, with diffusion coefficients ranging from 10 to 10, 10 to 10, and 10 to 10 cm·s at 25 °C, 40 °C, and 60 °C, respectively; the enthalpy of activation ranged between 127 and 194 kJ·mol. Moreover, migration depended on total PAE content of the product, as the diffusion coefficient for DINP in cPVC (softer PVC) was approximately three orders of magnitude higher than that for DINP in mPVC (harder PVC); this may be due to the increase in free volume with increasing plasticizer content. Finally, the daily exposure doses of the plasticizers were estimated. These findings will be helpful for estimating dermal exposure risk.
Topics: Plasticizers; Polyvinyl Chloride; Sebum; Phthalic Acids
PubMed: 36858231
DOI: 10.1016/j.scitotenv.2023.162412 -
Food Chemistry Dec 2023To develop food packaging with good antibacterial activity and mechanical performance, four amino carboxymethyl chitosan (ACC)//dialdehyde starch (DAS) /polyvinyl...
To develop food packaging with good antibacterial activity and mechanical performance, four amino carboxymethyl chitosan (ACC)//dialdehyde starch (DAS) /polyvinyl alcohol (PVA) films were prepared by Schiff base and hydrogen bond interactions for efficient loading and release of ε-polylysine (ε-PL). The effects of the Schiff base reaction on the physicochemical properties of the films were explored based on the different aldehyde group contents in DAS. The ACC//DAS/PVA film exhibited a tensile strength of 62.5 MPa, and the water vapor and oxygen permeability was 8.77 × 10·g·mm/m·d·kPa and 0.15 × 10·cm·mm/m·d, respectively. By leveraging the Schiff base reaction, the film swelling properties were improved by adjusting the cross-link density, mesh size, and molecular mass between the cross-links. The ACC//DAS/PVA film could efficiently load ε-PL with a value of 98.44% and long-term release in a food simulant of 10% ethanol at 25 °C for 120 min. Moreover, the ACC-ε-PL//DAS/PVA film was successfully used for salmon preservation.
Topics: Chitosan; Polyvinyls; Polyvinyl Alcohol; Polylysine; Schiff Bases; Anti-Bacterial Agents; Food Packaging
PubMed: 37423111
DOI: 10.1016/j.foodchem.2023.136775 -
Scientific Reports Feb 2022Clinical use of human pluripotent stem cells (hPSCs) is hampered by the technical limitations of their expansion. Here, we developed a chemically synthetic culture...
Clinical use of human pluripotent stem cells (hPSCs) is hampered by the technical limitations of their expansion. Here, we developed a chemically synthetic culture substrate for human pluripotent stem cell attachment and maintenance. The substrate comprises a hydrophobic polyvinyl butyral-based polymer (PVB) and a short peptide that enables easy and uniform coating of various types of cell culture ware. The coated ware exhibited thermotolerance, underwater stability and could be stored at room temperature. The substrate supported hPSC expansion in combination with most commercial culture media with an efficiency similar to that of commercial substrates. It supported not only the long-term expansion of examined iPS and ES cell lines with normal karyotypes during their undifferentiated state but also directed differentiation of three germ layers. This substrate resolves major concerns associated with currently used recombinant protein substrates and could be applied in large-scale automated manufacturing; it is suitable for affordable and stable production of clinical-grade hPSCs and hPSC-derived products.
Topics: Cell Adhesion; Cell Culture Techniques; Cell Differentiation; Cell Line; Cell Self Renewal; Human Embryonic Stem Cells; Humans; Induced Pluripotent Stem Cells; Peptides; Polyvinyls; Tissue Scaffolds
PubMed: 35169157
DOI: 10.1038/s41598-022-06356-8 -
Journal of Oral Science Oct 2022This study investigates the attenuation of radiation doses by four materials, heat-polymerized, and self-polymerized polymethyl methacrylate (PMMA), putty-type, and...
PURPOSE
This study investigates the attenuation of radiation doses by four materials, heat-polymerized, and self-polymerized polymethyl methacrylate (PMMA), putty-type, and injection-type polyvinyl siloxane (PVS) impression material. This in vitro study should aid in the selection of dental materials for radiotherapy prostheses, thereby minimizing the possibility of radiotherapy side effects.
METHODS
Specimens of each type were fabricated as a 5 × 5 cm squares with a thickness of 10 mm. Heat-polymerizing PMMA, self-polymerizing PMMA, putty-type PVS impression material, and injection-type PVS impression material were selected. A calibration curve was created to determine the association of radiation doses and grayscale value. A linear accelerator was used to irradiate the specimens. The radiation doses above and below the materials were measured using radiochromic film dosimetry. After film irradiation, the pixel scale of color change was used to determine the radiation dose based on the created calibration curve. The results were exported to find average doses to calculate the percentage of the attenuated dose for a comparison of the four materials.
RESULTS
The average attenuated doses of heat-polymerizing PMMA, self-polymerizing PMMA, putty-type PVS, and injection-type PVS were 10.8%, 6.2%, 17.2%, and 14.2% respectively.
CONCLUSION
PVS showed higher attenuating radiation exposure compared with PMMA.
Topics: Dental Implants; Dental Impression Materials; Polymethyl Methacrylate; Polyvinyls; Siloxanes
PubMed: 36070925
DOI: 10.2334/josnusd.22-0167 -
Colloids and Surfaces. B, Biointerfaces Oct 2022Soluplus® nanomicelles have been widely reported in biomedical field for their excellent drug loading capacity and solubility enhancement ability. However, when...
Soluplus® nanomicelles have been widely reported in biomedical field for their excellent drug loading capacity and solubility enhancement ability. However, when administrated in vivo, the protein corona will be formed on Soluplus® nanomicelles, significantly affecting their drug delivery performance. Up to now, few studies examined the protein corona formation process and its impact factors of Soluplus® nanomicelles. The multiple proteins in biofluids may form protein corona in different modes due to their diversified properties. In this study, Bovine serum albumin (BSA), Lysozyme (Lyso) and Bovine hemoglobin (BHb) were chosen as model proteins to investigate the protein corona formation process of Soluplus® nanomicelles. By analyzing the polarity of the protein amino acid residues distributing microenvironments, the results showed that there were two different protein corona formation modes, i.e., surface adsorption and insertion, which were determined by the hydrophilicity of proteins. The hydrophobic BHb followed the insertion mode while hydrophilic BSA and Lyso followed the surface adsorption mode. Ultimately, upon protein corona formation, the size and surface chemistry of nanomicelles was significantly affected. We believe this study will provide a new research paradigm to the design and application of Soluplus® nanomicelles.
Topics: Amino Acids; Muramidase; Polyethylene Glycols; Polyvinyls; Protein Corona; Serum Albumin, Bovine
PubMed: 35932562
DOI: 10.1016/j.colsurfb.2022.112744 -
Molecules (Basel, Switzerland) Dec 2022To satisfy the ever-increasing energy demands, it is of the utmost importance to develop electrochemical materials capable of producing and storing energy in a highly...
To satisfy the ever-increasing energy demands, it is of the utmost importance to develop electrochemical materials capable of producing and storing energy in a highly efficient manner. Titanium dioxide (TiO) has recently emerged as a promising choice in this field due to its non-toxicity, low cost, and eco-friendliness, in addition to its porosity, large surface area, good mechanical strength, and remarkable transport properties. Here, we present titanium dioxide nanoplates/polyvinylidene fluoride (TiO/PVDF) membranes prepared by a straightforward hydrothermal strategy and vacuum filtration process. The as-synthesized TiO/PVDF membrane was applied for energy storage applications. The fabricated TiO/PVDF membrane served as the negative electrode for supercapacitors (SCs). The electrochemical properties of a TiO/PVDF membrane were explored in an aqueous 6 M KOH electrolyte that exhibited good energy storage performance. Precisely, the TiO/PVDF membrane delivered a high specific capacitance of 283.74 F/g at 1 A/g and maintained capacitance retention of 91% after 8000 cycles. Thanks to the synergistic effect of TiO and PVDF, the TiO/PVDF membrane provided superior electrochemical performance as an electrode for a supercapacitor. These superior properties will likely be used in next-generation energy storage technologies.
Topics: Polyvinyls; Titanium; Water
PubMed: 36615478
DOI: 10.3390/molecules28010285