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Three-dimensional (3D) printed calcium phosphate cement (CPC) scaffolds are increasingly being used for bone tissue repair. Traditional materials used for CPC scaffolds, such as bovine and porcine bone, generally contain low amounts of calcium phosphate compounds, resulting in reduced production rates of CPC scaffolds. On the other hand, cockle shells contain more than 99% CaCO3 in the form of amorphous aragonite with excellent biocompatibility, which is expected to increase the CPC production rate. In this study, 3D-printed cockle shell powder-based CPC (CSP-CPC) scaffolds were developed by the material extrusion method. Lactic acid and hyaluronic acid were used to promote the printability. The characterization of CSP-CPC scaffolds was performed using Fourier transform infrared spectra, X-ray diffraction patterns, and scanning electron microscopy. The biocompatibility of CSP-CPC scaffolds was evaluated using cell viability, Live/Dead, and alkaline phosphatase assays. In addition, CSP-CPC scaffolds were implanted into the mouse calvarial defect model to confirm bone regeneration. This study provides an opportunity to create high value added in fishing villages by recycling natural products from marine waste. [ABSTRACT FROM AUTHOR]

A deprotonated 2,5-dihydroxyterephthalic acid (DHT) was synthesized to obtain a water-soluble, fluorescent molecule (DHT-K). The deprotonated DHT-K was converted to DHT upon exposure to acidic gas, changing fluorescence color from yellow to blue. DHT-K was incorporated to poly(vinyl alcohol) to form a film, and the film showed the same fluorescence change when exposed to HCl gas. The blue fluorescence of HCl-exposed DHT-K film was returned to yellow emission by simple treatment with NH3 gas, showing effective regeneration. Using detectable fluorescence changes by the naked eye, DHT-K can be a potential candidate for a fluorescent indicator toward HCl gas. [ABSTRACT FROM AUTHOR]

Though 2,5-dihydroxyterephthalic acid (DHT) is composed of a single benzene molecule, it is blue-emissive in common organic solvents and in the solid state. Like most organic fluorophores, DHT is not soluble in water, which limits its versatile use in metal ion detection in an aqueous medium. To improve the water solubility of DHT and its use as a molecular sensor in aqueous solutions, its deprotonated form, DHT-K, was synthesized through the simple one-pot reaction of DHT with KOH. Compared with DHT, DHT-K was highly soluble in water and emitted yellow fluorescence in the solution and the solid. In addition, DHT-K showed high selectivity for Al ions, exhibiting fluorescence wavelength changes from 540 to 495 nm depending on the Al ion concentration. A linear relationship between the fluorescence intensity of DHT-K and Al ion concentration was established ranging from 18.96 to 247 μM with a detection limit of 1.84 µM. The binding stoichiometry between DHT-K and Al ions was determined by Job's plot and found to be 1:2. Upon exposure to Al ions, DHT-K showed significant changes in fluorescence color and emission wavelength, whereas no fluorescence changes were observed by the addition of various metal ions such as Zn2+, Mg2+, Ca2+, Cu2+, Fe3+, and Co2+. Thus, DHT-K can be applied as a fluorescent sensor that can selectively detect Al ions in aqueous solutions. [ABSTRACT FROM AUTHOR]

A single‐benzene‐based, blue‐emissive diethyl 2,5‐dihydroxyterephthalate (DDT) was prepared by Fischer esterification of 2,5‐dihydroxyterephthalic acid (DHT) and ethanol. The strong fluorescence in both the solution and the solid state from such a simple framework stemmed from the push‐pull structure of the electron‐donating hydroxy groups and the accepting carbonyl groups, as well as structural planarity from intramolecular hydrogen bonds. The strong intermolecular hydrogen bonds enabled DDT to crystallize easily. The color CCD imaging technique showed efficient 1D optical waveguiding with a large optical loss coefficient of 0.15 dB/μm. DDT has potential application in optical sensors, photonic devices, and optoelectronic communication, because of its highly ordered structure and light‐emitting ability. [ABSTRACT FROM AUTHOR]

Based on a conventional cation-exchange polymer resin, Cs ion exchange resins were fabricated for the removal of radioactive Cs via two preparation methods. Prussian blue (PB), which have been commonly used to remove radioactive 137Cs, was synthesized on the surface of resins. To provide a strong interaction between the polymer resin and PB, polydopamine (PDA) was used as a linker, present on the surface of the polymer resins. Based on the same principle, two types of Cs ion exchange resins were prepared via different orders of fabrication sequence. From the removal test of Cs ions, it was found that the two types of the resins did not show noticeable difference in adsorption of Cs ions, in which adsorption of Cs ions took place heterogeneously and chemically with multilayer adsorption. [ABSTRACT FROM AUTHOR]

Highlights • Sodium alginate beads containing chemically bound PB beads were prepared. • The beads showed improved adsorption of Cs ions compared to conventional sodium alginate beads containing PB. • The beads showed efficient adsorption in a fixed bed column as well as in a batch with good stability. • The beads exhibited high removal efficiency toward radioactive 137Cs. Abstract A new approach for efficient removal of radioactive 137Cs was developed using a sodium alginate hydrogel beads-based adsorbent containing chemically bound Prussian blue (PB). Sodium alginate was crosslinked with Fe (III) ions to form hydrogel beads, in which Fe (III) had a dual function; it served as a crosslinking agent and also led to PB formation via reaction with hexacyanoferrate. Fe (III) ions, an unusual crosslinking agent for sodium alginate gel, led to stable, homogeneous distribution of PB inside the beads. The amount of embedded PB in the composite beads was more than two times larger than in the conventional sodium alginate-PB composite beads, resulting in an adsorption capacity for Cs ions that was two to five times higher, mainly because of a higher PB contents and because of the microporosity of the sodium alginate hydrogel. [ABSTRACT FROM AUTHOR]

We prepared shape-controllable, sodium alginate-based hydrogels containing various particles inside the hydrogels. Centrifugal injection method was employed to obtain smaller sized gels, compared to that fabricated by conventional method. A conventionally-fabricated gel beads were spherically-shaped, in which the shape was determined by the droplets of sodium alginate solution from syringe needle. The shape of the gels was easily manipulated to obtain hollow-cylindrical gels by simple use of embedding particles and by changing the concentration of sodium alginate, calcium chloride, and the embedding components. As a result, the hollow-centered gels with the unique shape were obtained. [ABSTRACT FROM AUTHOR]

Radioactive Cs ions are extremely harmful to the human body, causing cancers and other diseases. Treatments were performed on radioactive Cs present in wastewater after use in industrial or medical fields. Prussian blue (PB) has been widely used for the removal of Cs ions from water but its colloidal structure hinders reuse, making it problematic for practical use. To solve this problem, we used a commercial macroporous polymer resin as a PB matrix. To provide an efficient anchor for PB, the surface of the polymer resin was decorated with sodium dodecylbenzenesulfonate to produce a negatively charged surface. The successful chemical binding between the polymer resin and PB prevented leakage of the latter during adsorption and crosslinked structure of the matrix provided regeneration of the adsorbent. The adsorbent maintained its removal efficiency after five repeats of the regeneration process. The PB-based, Cs ion-exchange resin showed excellent selectivity toward Cs ions and good reusability, maintaining its high adsorption capacity. Image 1 • Cs ion-exchange resin was synthesized from polystyrene-based resin beads containing Prussian blue (PB). • Adsorption of SDBS by the polymer resin was efficiently carried out by the presence of PB. • The crosslinked adsorbent provided easy and stable reusability without any PB leakage. [ABSTRACT FROM AUTHOR]

This study was performed to examine whether the use of nitrogen-doped carbon nanodots (N-CNDs) can improve the detection sensitivity of the 3 M™ molecular detection system (MDS) for Campylobacter. N-CNDs were added to a Campylobacter enrichment broth (CEB) at concentrations of 5 and 10 mg/mL (NCEB-5 and NCEB-10, respectively). Campylobacter coli , C. jejuni , and C. lari were inoculated into the broths. The broth cultures were then irradiated with light-emitting diode (LED) at 425 nm for 1 h and incubated at 42 °C for 6 h, and then grown on modified charcoal cefoperazone deoxycholate agar (mCCDA). The detection rates of the MDS and a conventional method (plating an enriched sample on mCCDA and analyzing a colony on mCCDA with PCR) for Campylobacter in chicken and duck carcasses were compared. The detection rates from the MDS were compared after enrichment in CEB and NCEB-5 at 3, 5, 6, 7, 9, 12, and 24 h. When 5 mg/mL of N-CNDs was added to the CEB followed by irradiation at 425 nm, growth of the Campylobacter was accelerated. In addition, the qualitative test was more sensitive in the MDS than in the conventional method, and the detection time was shortened in CEB enriched with N-CNDs. These results indicate that adding N-CNDs to CEB can improve the detection efficiency of MDS. • Campylobacter detection is hampered by the presence of competing bacteria. • Campylobacter detection efficiency of the MDS was improved by adding nitrogen-doped carbon nanodots (N-CNDs). • The addition of N-CNDs accelerated the growth of Campylobacter. [ABSTRACT FROM AUTHOR]