Search

The chemical reaction between Fe and lacquer has been used to create the black color in lacquer coatings since ancient times. Here, the effects of Fe ion addition, UV irradiation, and heating on the microscopic structures of black lacquer films were investigated by using X-ray absorption near edge structure (XANES), extended X-ray absorption fine structure (EXAFS), Fourier transform-infrared spectroscopy (FT-IR), small-angle X-ray scattering (SAXS), and small angle neutron scattering (SANS). The EXAFS result indicated that heating and UV irradiation made the coordination structure of Fe3+in the lacquer nonuniform, and that heating caused the greatest nonuniformity. The FT-IR, SAXS, and SANS results demonstrated that the microscopic structural changes in the black lacquer films were induced by both heating and UV irradiation, but the changes were different. Heating caused a substantial structural change on the nanoscale, and UV irradiation mainly caused changes in the molecular binding mode. The results provide important knowledge for analyzing archeological lacquer samples and for developing lacquer-based materials. This work also demonstrates the utility of the complementary use of XANES, EXAFS, FT-IR, SAXS, and SANS for nondestructive analysis of black lacquer in precious cultural relics.

The phase separation of ice crystals and solutes and bound water that occurs during freezing can be used as a reaction field to control a hierarchical structure of hydrogels. Here, we present a study of carboxymethyl cellulose nanofiber (CMCF) hydrogels formed using solid-quasi liquid phase separation. CMCF hydrogels were formed simply by adding citric acid to frozen CMCF and thawing the mixture. The compressive strength of the freeze crosslinked CMCF was 200,000 times higher than that of CMCF hydrogel formed by a conventional crosslinking method. It was found that rearrangement of CMCF structures via hydrogen bonding proceeds in the freeze concentration layer before the ice crystals melt. Under freeze concentration, CMCF and bound water are confined at high concentrations. The crosslinking reaction in such a unique space contributed to the formation of CMCF hydrogel with high mechanical strength. We discuss the gelation behavior and properties of freeze crosslinked CMCF hydrogels and their applications.The phase separation of ice crystals and solutes and bound water that occurs during freezing can be used as a reaction field to form structurally ordered hydrogels. This paper presents a study of freeze-crosslinked carboxymethyl cellulose nanofiber (CMCF) hydrogels with high mechanical strength formed using the solid-quasi liquid phase separation.

To investigate the ability of hydrogels to separate hydrogen isotopes in water, we analyzed the Raman spectra of poly-N,N-dimethylacrylamide (PDMAA) hydrogels containing deuterated water during dehydration. The results show a significant fractionation of hydrogen isotopes during dehydration. The D/(D+H) molar ratio of the hydrogel increases from 0.056 to ∼0.2 during dehydration from 90.5 to 5 wt % in water content. The result indicates that the isotope effects on equilibrium vapor pressures are more prominent for water in hydrogels than for ordinary water. The ratio of the equilibrium vapor pressures of normal and deuterated waters gradually changes with the water content in hydrogels because four types of water exist in PDMAA hydrogels. The results suggest that hydrogels are an efficient material for isotope fractionation with evaporation.

Systems for capture, storage and analysis of eccrine sweat can provide insights into physiological health status, quantify losses of water, electrolytes, amino acids and/or other essential species, and identify exposures to adverse environmental species or illicit drugs. Recent advances in materials and device designs serve as the basis for skin-compatible classes of microfluidic platforms and in situcolorimetric assays for precise assessments of sweat rate, sweat loss and concentrations of wide-ranging types of biomarkers in sweat. This paper presents a set of findings that enhances the performance of these systems through the use of microfluidic networks, integrated valves and microscale optical cuvettes formed by three dimensional printing in hard/soft hybrid materials systems, for accurate spectroscopic and fluorometric assays. Field studies demonstrate the capability of these microcuvette systems to evaluate the concentrations of copper, chloride, and glucose in sweat, along with the pH of sweat, with laboratory-grade accuracy and sensitivity.

Advances in hazardous metal ion removal are essential for wastewater clean-up to tackle the global water shortage crisis. Here, we report a Pb-selective adsorbent using a Tb oxalate framework (TOF) synthesized by a one-pot hydrothermal method. The TOF has a two-dimensional sheet structure, in which the interlayer space functions as an ion exchangeable site. Sorption tests using a mixed-ion solution containing Pb2+, Cd2+, Mn2+, Co2+, Ni2+, Cu2+, Na+, K+, Mg2+, and Ca2+showed that the TOF has high selectivity for Pb2+among other metal ions. The saturated adsorption capacity of the TOF for Pb2+was 276 mg g−1, which is higher than that of conventional adsorbents. Furthermore, the TOF exhibited reversible Pb2+adsorption/desorption and could be used for at least three cycles. The results showed that TOF has excellent potential as an adsorbent for removing Pb2+, and because of its reusability, it is also a promising material for wastewater clean-up.A Tb oxalate framework (TOF) was synthesized by a one-pot hydrothermal method. The TOF is highly selective for Pb2+, reusable, and has a high saturated adsorption capacity (276 mg g−1), which is higher than that of conventional adsorbents. The result showed that TOF is a potential adsorbent for removing Pb2+, making it a promising material for wastewater clean-up.

Raman spectroscopy was used to investigate the temperature dependence of structural changes of bound water in dried glassy poly-N,N,-dimethylacrylamide in the temperature range 286.1−329.7 K. The results show that the frequency of the O−H stretching mode of the bound water that is present in the dried glassy polymer shifts to the higher side with increasing temperature. The rate changes at around 310 K, while that for the bulk water is constant in the temperature range studied. The rates of change of the frequencies for the CO stretching mode and CH3rocking mode also change at around 310 K. These results indicate a significant change in the interaction between the bound water and polymer chains at 310 K. Temperature dependence of the local structure of the bound water was analyzed by applying a structural model of bulk water to the spectra of the O−H stretching region. The result shows that the density of a tetragonal water structure consisting of four hydrogen bonds increases with increasing temperature below 310 K and begins to decrease at temperatures above 310 K. Further, estimates of the water content indicate that the evaporation rate of the bound water significantly changes at around 310 K. These results suggest that the bound water present in the dried glassy polymer can be classified as being in two states. At temperatures below 310 K, the water that forms a shell layer around the polymer chains evaporates, while at temperatures above 310 K the water that is bound to polar groups of polymer chains begins to evaporate. The structural changes of bound water might have important implications for the interpretation of properties of hydrated polymer systems, including both biological and synthetic polymers.

Systems for “protein transduction,” intracellular delivery of functional proteins, are needed to address deliverability challenges of protein therapeutics. However, in vivo protein transduction remains challenging because of instability in serum, extracellular protease digestion and rapid excretion from the bloodstream. Here, a magnetically guided in vivo protein transduction using magnetic nanogel chaperone (MC) composed of iron oxide nanoparticles and a polysaccharide nanogel, a protein carrier inspired by “catch and release” mechanisms of molecular chaperones is demonstrated. The MC system enables efficient delivery of anti‐cancer proteins, saporin and RNaseA, into cultured tumor lines and inhibits cell proliferation, mainly via apoptosis. Magnetic in vivo protein transduction via intravenous whole body administration is demonstrated in a fibrosarcoma model. By in vivo optical imaging, MC accumulated in tumor tissues under magnetic field three times more than without irradiation. With subcutaneous injection, saporin is delivered by MC to the cytoplasm in magnetically targeted tissues. In an oral cancer model, MC‐delivered magnetically targeted saporin decreased tumor volume without significant body weight changes and no regrowth of tumor at 3 months after complete regression. Protein transduction with MC shows promise for cancer therapeutics and, potentially, for regenerative medicine and other biomedical applications. In this study, magnetic nanogel chaperone comprising self‐assembled polysaccharide nanogels and iron‐oxide nanoparticles is developed for magnetically navigated in vivo protein transduction. Magnetic navigation enhances accumulation of magnetic nanogel chaperone toward tumor tissues. Saporin‐loaded magnetic nanogel chaperone exhibits excellent anti‐tumor efficacy against oral cancer xenograft mice in vivo.

In article number 2001988by Yoshihiro Sasaki, Kazunari Akiyoshi, and co‐workers, the magnetic nanogel chaperone, comprising of self‐assembled polysaccharide nanogels and iron oxide nanoparticles, is developed for magnetically navigated in vivo protein transduction. Magnetic navigation enhances accumulation of the magnetic nanogel chaperone toward tumor tissues. Saporin‐loaded magnetic nanogel chaperone exhibits excellent anti‐tumor efficacy against oral cancer xenograft mice in vivo.

The effective, low-cost decontamination of toxic metals is critical for addressing global health risks, reducing environmental pollution, and building a sustainable future. Here, we developed an eco-friendly hydroxyapatite nanocrystal adsorbent made from bone waste that can effectively capture 90Sr. Highly carbonated nanohydroxyapatite (C-NHAP) crystals with a negatively charged surface were obtained by simply immersing pig bone in an aqueous solution of sodium hydrogen carbonate (NaHCO3). Fourier transform infrared spectra showed that the C-NHAP was highly carbonated and that the amount of introduced carbonate ions (CO32−) increased with increasing NaHCO3concentration in the immersion solution. With increasing amount of CO32−ions introduced into the C-NHAP, it exhibited a greater ion-adsorption performance. The distribution coefficient (Kd=24,780 mL g−1) of the C-NHAP for Sr2+was approximately 20 and 250 times greater than those of clinoptilolite and untreated bone, respectively. The C-NHAP also exhibited high adsorption capacity (Qe=125 mg g−1) for Sr2+. The extended X-ray absorption fine structure spectra showed that the CO32−sites in C-NHAP played an important role in its high adsorption performance. The C-NHAP exhibited high adsorptivity for Cd2+, Pb2+, and Cu2+. The C-NHAP prepared from bone waste is an eco-friendly, high-performance, low-cost material that should be useful in environmental pollutant removal and food waste disposal.