Low-concentration alkali treatments at low temperatures facilitate the crystal transition of cellulose I to II. However, the transition mechanism remains unclear. Hence, in this study, we traced the transition using in situ solid-state C CP/MAS NMR, WAXS, and Na NMR relaxation measurements.
View Article and Find Full Text PDFThe group-transfer polymerization (GTP) of ,-bis(2-methoxyethyl)acrylamide (MOEAm) initiated by MeEtSiH in the hydrosilylation-promoted method and by silylketene acetal (SKA) in the conventional method proceeded in a controlled/living manner to provide poly(,-bis(2-methoxyethyl)acrylamide) (PMOEAm) and PMOEAm with the SKA residue at the α-chain end (MCIP-PMOEAm), respectively. PMOEAm--poly(dimethylacrylamide) (PDMAm) and PMOEAm--PDMAm and PMOEAm--poly(-bis(2-ethoxyethyl)acrylamide) (PEOEAm) and PMOEAm--PEOEAm were synthesized by the block and random group-transfer copolymerization of MOEAm and dimethylacrylamide or -bis(2-ethoxyethyl)acrylamide. The homo- and copolymer structures affected the thermoresponsive properties; the cloud point temperature () increasing by decreasing the degree of polymerization (x).
View Article and Find Full Text PDFVideo 1Crush the large-sized stones directly using an electrohydraulic lithotripsy device.
View Article and Find Full Text PDFSilver nanoparticles (AgNPs) are used in a wide range of applications, and the size control and stability of the nanoparticles are crucial aspects in their applications. In the present study, cyclized poly(ethylene glycol) (-PEG) with various molecular weights, along with linear PEG with hydroxy chain ends (HO-PEG-OH) and methoxy chain ends (MeO-PEG-OMe) were applied for the Tollens' synthesis of AgNPs. The particle size was significantly affected by the topology and end groups of PEG.
View Article and Find Full Text PDFNanoscale Adv
January 2022
Silver nanoparticles (AgNPs) are practically valuable in biological applications. However, no steady PEGylation has been established, which is essential for internal use in humans or animals. In this study, cyclic PEG (-PEG) without any chemical inhomogeneity is physisorbed onto AgNPs to successfully PEGylate and drastically enhance the dispersion stability against physiological conditions, white light, and high temperature.
View Article and Find Full Text PDFSnare devices play an important role in treatment of intestinal polyps. However, there are no objective measurements for the characteristics of the various types of snare devices. Seven types of snare devices from four manufacturers were evaluated based on original measurements.
View Article and Find Full Text PDFA series of cyclic surfactants were synthesized from a poly(ethylene glycol) (PEG) homopolymer and Pluronic surfactants L35, L64, P123, F68, 10R5, and 17R4, and their interfacial activity depending on the topology, chain ends, and block sequence was investigated. The cyclization was performed in a single step through etherification of the PEG homopolymer and the hydrophilic-hydrophobic-hydrophilic (ABA type) poly(ethylene glycol)-poly(propylene glycol)-poly(ethylene glycol) (PEG-PPG-PEG), while the hydrophobic-hydrophilic-hydrophobic (BAB type) PPG-PEG-PPG was cyclized via acetalization. The cyclized surfactants were rigorously characterized by nuclear magnetic resonance spectroscopy and size exclusion chromatography.
View Article and Find Full Text PDFUltrathin endoscopes are commonly used for surveillance esophagogastroduodenoscopy (EGD) to reduce discomfort associated with scope insertion. However, the flexibility of an ultrathin endoscope is a trade-off between reducing discomfort and lengthening examination time. The EG17-J10 (EG17) is a novel ultrathin endoscope characterized by its tapering body stiffness; however, the flexibility of its tip is comparable to that of the traditional ultrathin endoscope EG16-K10 (EG16).
View Article and Find Full Text PDFSingle-photon sources and their optical spin readout are at the core of applications in quantum communication, quantum computation, and quantum sensing. Their integration in photonic structures such as photonic crystals, microdisks, microring resonators, and nanopillars is essential for their deployment in quantum technologies. While there are currently only two material platforms (diamond and silicon carbide) with proven single-photon emission from the visible to infrared, a quantum spin-photon interface, and ancilla qubits, it is expected that other material platforms could emerge with similar characteristics in the near future.
View Article and Find Full Text PDFA quinoline-based hexadentate ligand, (,)-,,,-tetrakis(6-methoxy-2-quinolylmethyl)-1,2-diphenylethylenediamine ((,)-6-MeOTQPhEN), exhibits fluorescence enhancement at 498 nm upon addition of 1 equiv of Zn (/ = 12, φ = 0.047) in aqueous DMF solution (DMF/HO = 2:1). Addition of 1 equiv of Cd affords a much smaller fluorescence increase at the same wavelength (/ = 2.
View Article and Find Full Text PDFA 54-year-old man with diarrhea and hematochezia for 2 months was referred to our department. A total colonoscopy revealed amoebic colitis caused by Entamoeba histolytica. Concurrently, a submucosal tumor-like yellowish hemispheric polypoid lesion was incidentally detected in the rectum.
View Article and Find Full Text PDFWe report the enhancement of the optical emission between 850 and 1400 nm of an ensemble of silicon mono-vacancies (V), silicon and carbon divacancies (VV), and nitrogen vacancies (NV) in an n-type 4H-SiC array of micropillars. The micropillars have a length of ca. 4.
View Article and Find Full Text PDFEGTA (ethylene glycol bis(2-aminoethyl ether)-N,N,N',N'-tetraacetic acid) and BAPTA (1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid) are well-known Ca2+ chelators that have four carboxylates, two nitrogen atoms and two ether oxygen atoms. In the present study, we prepared EGTQ (N,N,N',N'-tetrakis(2-quinolylmethyl)-1,2-bis(2-aminoethoxy)ethane) and BAPTQ (N,N,N',N'-tetrakis(2-quinolylmethyl)-1,2-bis(2-aminophenoxy)ethane) as quinoline alternatives of EGTA and BAPTA, respectively. In methanol-HEPES buffer solution (9 : 1, 50 mM HEPES, 0.
View Article and Find Full Text PDFWe characterized intrinsic deep level defects created in ion collision cascades which were produced by patterned implantation of single accelerated 2.0 MeV He and 600 keV H ions into n-type 4H-SiC epitaxial layers using a fast-scanning reduced-rate ion microbeam. The initial deep level transient spectroscopy measurement performed on as-grown material in the temperature range 150-700 K revealed the presence of only two electron traps, Z (0.
View Article and Find Full Text PDFA quinoline-based heptadentate ligand, N,N,N',N'-tetrakis(2-quinolylmethyl)-3-oxa-1,5-pentanediamine (TQOPEN), exhibits a fluorescence increase (I/I = 25, ϕ = 0.017) at 428 nm upon addition of 1 equiv of Cd. In contrast, 1 equiv of Zn induces a negligible fluorescence change due to weak interaction (I/I = 2.
View Article and Find Full Text PDFAn isoquinoline-based ligand, N,N,N',N'-tetrakis(1-isoquinolylmethyl)-2-hydroxy-1,3-propanediamine (1-isoHTQHPN), exhibits a fluorescence increase at 475 nm upon addition of 1 equiv. of Zn(2+) (IZn/I0 = 12, ϕZn = 0.023).
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