[en] Iron incorporated into food can induce precipitation and unwanted interaction with other components in food. Iron-binding proteins represent a possibility to avoid these problems and other side effects, as the iron is protected. However, there are several technical problems associated with protein–iron complex formation. In this paper, the iron-binding phosphorylated human-like collagen (Fe-G6P-HLC) was prepared under physiological conditions through phosphorylated modification. One molecule of Fe-G6P-HLC possesses about 24 atoms of Fe. Spectroscopy analysis, differential scanning calorimetry (DSC) and equilibrium dialysis techniques were employed to investigate the characteristics of the Fe-G6P-HLC. The binding sites (n_b) and apparent association constant (K_app) between iron and phosphorylated HLC were measured at n_b = 23.7 and log K_app = 4.57, respectively. The amount of iron (Fe²⁺ sulfate) binding to phosphorylated HLC was found to be a function of pH and phosphate content. In addition, the solubility and thermal stability of HLC were not significantly affected. The results should facilitate the utilization of HLC as a bioactive iron supplement in the food and medical industry and provide an important theoretical evidence for the application of HLC chelates. - Highlights: • The iron-binding phosphorylated human-like collagen (Fe-G6P-HLC) was prepared. • One molecule of Fe-G6P-HLC possesses about 24 atoms of Fe. • The binding properties could be modulated through alterations in pH and phosphate content presented in HLC. • A novel strategy for preparing iron-binding proteins was provided

[en] Protein preparation, which has active ingredients designated for the use of biomaterials and therapeutical protein, is obtained by genetic engineering, but products of genetic engineering are often contaminated by endotoxins. Because endotoxin is a ubiquitous and potent proinflammatory agent, endotoxin removal or depletion from protein is essential for researching any biomaterials. In this study, we have used Tris-acetate (TA) buffer of neutral pH value to evaluate endotoxins absorbed on the Pierce high-capacity endotoxin removal resin. The effects of TA buffer on pH, ionic strength, incubation time as well as human-like collagen (HLC) concentration on eliminating endotoxins are investigated. In the present experiments, we design an optimal method for TA buffer to remove endotoxin from recombinant collagen and use a chromogenic tachypleus amebocyte lysate (TAL) test kit to measure the endotoxin level of HLC. The present results show that, the endotoxins of HLC is dropped to 8.3 EU/ml at 25 mM TA buffer (pH 7.8) with 150 mM NaCl when setting incubation time at 6 h, and HLC recovery is about 96%. Under this experimental condition, it is proved to exhibit high efficiencies of both endotoxin removal and collagen recovery. The structure of treated HLC was explored by Transmission Electron Microscopy (TEM), demonstrating that the property and structure of HLC treated by TA buffer are maintained. Compared to the most widely used endotoxin removal method, Triton X-114 extraction, using TA buffer can obtain the non-toxic HLC without extra treatment for removing the toxic substances in Triton X-114. In addition, the present study aims at establishing a foundation for further work in laboratory animal science and providing a foundation for medical grade biomaterials. - Graphical abstract: The processes of endotoxins adsorbed from HLC. - Highlights: • TA buffer is a mild buffer system for endotoxins removal of HLC. • TA buffer may facilitate endotoxins adsorbed on the resin efficiently. • TA buffer has high-efficiency endotoxin removal and high HLC recovery efficiency

[en] Injectable hydrogel plays an important role in soft tissue filling and repair. We report an injectable hydrogel based on hyaluronic acid (HA) and human-like collagen (HLC), both with favorable biocompatibility and biodegradability. These two types of biomacromolecules were crosslinked with 1,4-butanediol diglycidyl ether to form a three-dimensional network. The redundant crosslinker was removed by dialysis and distillation. An HA-based hydrogel prepared by the same method was used as a control. The cytocompatibility was studied with a Cell Counting Kit-8 (CCK-8) test. Carbazole colorimetry was used to analyze the in vitro degradation rate. The histocompatibility was evaluated by hematoxylin and eosin (H and E) staining analysis and immunohistochemical analysis. The CCK-8 assay demonstrated that the HA/HLC hydrogel was less cytotoxic than the HA-based hydrogel and could promote baby hamster kidney cell (BHK) proliferation. The cell adhesion indicated that BHK could grow well on the surface of the materials and maintain good cell viability. The in vitro degradation test showed that the HA/HLC hydrogel had a longer degradation time and an excellent antienzyme ability. In vivo injection showed that there was little inflammatory response to HA/HLC after 1, 2, and 4 weeks. Therefore, the HA/HLC hydrogel is a promising biomaterial for soft tissue filling and repair. - Highlights: • Human-like collagen was used with hyaluronic acid to prepare soft tissue filling meterials. • 1,4-Butanediol diglycidyl ether (BDDE) was introduced to treat the hydrogels. • The addition of human-like collagen could improve the biological properties of hydrogels

[en] Objective: To analyze the CT perfusion characteristics and hemodynamic changes of type n autoimmune pancreatitis. Methods: Whole organ low-dose CT perfusion characteristics and hemodynamic changes of type n autoimmune pancreatitis (7 patients) were compared to that of normal pancreas (11) and pancreatic carcinoma (8). Results: Of 7 patients with autoimmune pancreatitis, 5 were located in the head and 2 in the body and tail of the pancreas with pancreatic duct dilatation (5), extrahepatic bile duct dilatation (4), and ulcerative colitis (1). Time-density curve analysis showed diffusely reduced enhancement in autoimmune pancreatitis with significantly different perfusion parameters (P < 0.05) from that of pancreatic carcinoma. Conclusion: CT perfusion imaging allows quantitative evaluation of the hemodynamic changes for diagnosing type n autoimmune pancreatitis. (authors)

[en] Here we report a Li-metal-free full battery, using interlayer-expanded V_6O_1_3 ultra-thin nanosheets and prelithiated graphite for cathodes and anodes, respectively. This full Li-ion battery exhibits a superior specific capacity of 233 mAh g"−"1 at a current density of 100 mA g"−"1 and 91% capacity retention after 500 cycles. Our first-principle calculations reveal that the interlayer-expansion is induced by the interaction between V_6O_1_3 and water which breaks interlayer V-O bonds and forms hydroxyls. The unique structure provides short lithium-ion diffusion path, excellent charge transport, abundant binding sites and volume flexibility for Li"+ intercalation/deintercalation, thus leading to high capability (280 mAh g"−"1) and cycling performance (capacity retain 96.1% at 2.4 A g"−"1 for 1000 cycles). Using novel prelithiation process, the Li-metal-free full cells with high controllability and performance is expected to contribute significantly to the development of safe, green, and powerful energy storage devices.

[en] Wound dressings play an indispensable role in wound healing. However, traditional wound dressings have several disadvantages, such as poor mechanical properties and small pore diameters, which do not allow sufficient gas exchange. To overcome these shortcomings, this paper reports a polyvinyl alcohol (PVA)-based hydrogel physically crosslinked at −20 °C and containing polyethylene glycol (PEG) and nanohydroxyapatite (HAP). The physical and chemical properties of the hydrogels formed by different stirring methods (stirring with a glass rod or a hand-held homogenizer) were compared. The average roughness of Gel 1 (prepared using a hand-held homogenizer) is 112.6 nm, which is much lower than the average surface roughness of Gel 2 (1222 nm, prepared using a glass rod). Moreover, the hydrogel made by the unconventional mixing method (with a homogenizer) showed better performance, including a more interconnected open-pore microstructure and better mechanical properties. Finally, a full-thickness skin defect test was performed. The experimental results demonstrated that the hydrogel has considerable potential for applications in wound dressings. (paper)

[en] We investigate the detailed analysis of the magnetic properties in a series of Pr_1–xSm_xFeO₃ single crystals from x = 0 to 1 with an interval of 0.1. Doping controlled spin reorientation transition temperature T _SR Γ₄ (G _x, A _y, F _z) to Γ₂ (F _x, C _y, G _z) covers a wide temperature range including room temperature. A ‘butterfly’-shape type-I spin switching with 180° magnetization reversal occurs below and above the magnetization compensation points in x = 0.4 to 0.8 compounds. Interestingly, in Pr_0.6Sm_0.4FeO₃ single crystal, we find an inadequate spin reorientation transition accompanied by uncompleted type-I spin switching in the temperature region from 138 to 174 K. Furthermore, a type-II spin switching appears at 23 K, as evidenced from the magnetization curve in field-cooled-cooling (FCC) mode initially bifurcate from zero-field-cooled (ZFC) magnetization curve at 40 K and finally drops back to coincide the ZFC magnetization value at 23 K. Our current research reveals a strong and complex competition between Pr³⁺–Fe³⁺ and Sm³⁺–Fe³⁺ exchange interactions and more importantly renders a window to design spintronic device materials for future potential applications. (paper)

[en] The search for low-dimensional materials with unique electronic properties is important for the development of electronic devices in the nanoscale. Through systematic first-principles calculations, we found that the band gaps of the two-dimensional honeycomb monolayers (HMs) and one-dimensional single-walled nanotubes (SWNTs) of IIB–VI semiconductors (ZnO, CdO, ZnS and CdS) are nearly chirality-independent and weakly diameter-dependent. Based on analysis of the electronic structures, it was found that the conduction band minimum is contributed to by the spherically symmetric s orbitals of cations and the valence band maximum is dominated by the in-plane $(d_{xy}-<!--\; ???\; -->p_y)$ and $(d_{x^2-<!--\; ???\; -->y^2}-<!--\; ???\; -->p_x)$ hybridizations. These electronic states are robust against radius curvature, resulting in the invariant feature of the band gaps for the structures changing from HM to SWNTs. The band gaps of these materials range from 2.3 to 4.7 eV, which is of potential application in electronic devices and optoelectronic devices. Our studies show that searching for and designing specific electronic structures can facilitate the process of exploring novel nanomaterials for future applications. (paper)

[en] Shale was thermally treated to obtain a series of kerogen with varied maturation. Their chemical, structural and porous properties were related to the sorption and/or desorption behaviors of phenanthrene and benzene. As the treatment temperature increases, aliphatic and carbonyl carbon of the kerogen samples decrease, while their aromaticity and maturation increase. Meanwhile, the isothermal nonlinearity of phenanthrene and benzene increases whereas the sorption capacity and micropore adsorption volumes (V_o,d) initially increase and then decrease. The V_o,d of benzene is significantly correlated with, but higher than that of phenanthrene, suggesting similar micropore filling mechanism and molecular sieve effect. The benzene desorption exhibits hysteresis, which is related to the pore deformation of the kerogen and the entrapment of solute in the kerogen matrix. The V_o,d of phenanthrene and benzene on the kerogen samples accounts for 23–46% and 36–65% of the maximum sorption volumes, respectively, displaying the importance of the micropore filling. -- Highlights: • The microporosity estimated by benzene vapor differs greatly from that by N₂. • The micropore volume changes with kerogen maturation. • The phenanthrene or benzene sorption is related to the microporosity of kerogen. • Higher adsorption volume for benzene than for phenanthrene suggests molecular sieve effect. • The pore-filling plays an important role in the sorption of phenanthrene and benzene. -- The sorption behaviors of benzene and phenanthrene are related to the microporosity of the differently matured kerogen, indicating the importance of pore-filling

[en] The contents of nonhydrolyzable organic matter (NHC) and black carbon (BC) were measured in soils and sediments from the Pearl River Delta, South China. Polycyclic aromatic hydrocarbons (PAHs) were extracted respectively by Soxhlet and an accelerated solvent extraction device (ASE) using different solvents. In addition, sequential aqueous leaching at different temperatures was carried out. The PAH content extracted with the sequential three solvent ASE is two times higher than that using the Soxhlet extraction method. The relationship of the PAH content with the NHC content is very significant. The PAH concentrations measured at various temperature steps fit well to the Van't Hoff equation and the enthalpy was estimated. The investigation indicates that condensed organic matter such as kerogen carbon, aged organic matter, and BC is relevant for the extraction and distribution of native PAHs in the investigated field soils and sediments. - Kerogen carbon and aged organic matter is important for the extraction and distribution of native PAHs in the soils and sediments