Novel underwater tissue-selective adhesive hydrogels with adhesion energy to wet porcine skin of ∼1011 J m−2 were made by bio-mimicking Mfps.

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Tough adhesive hydrogels that can tightly bond to wet tissue/polymer/ceramic/metal surfaces have great potentials in various fields. However, conventional adhesive hydrogels usually show shortterm and nonreversible adhesion ability, as the water component in a hydrogel readily transforms to vapor or ice in response to fluctuation of environment temperature, hindering their applications in extreme conditions such as in freezing Arctic and roasting Africa. For the first time, urushiol (UH), a natural catechol derivative with a long alkyl side chain, is used as a starting material to copolymerize with acrylamide for fabricating adhesive hydrogels, which contain hydrophobic/hydrophilic moieties, antifreezing agent, and adhesive catechol groups. The antifreezer/moisturizer glycerol/water binary solvent dispersed in the hydrogel endows it with antifreezing/antiheating property. The hydrophobic association and π−π interaction from UH moieties of the copolymer greatly improve its mechanical strength (tensile stress: ∼0.12 MPa with strain of ∼1100%, toughness: ∼72 kJ/m 3 , compression stress: ∼6.72 MPa at strain of 90%). The hydrogel can strongly adhere to various dry/wet biological/polymeric/ ceramic/metallic substrates at temperatures ranging from −45 to 50 °C. Under ambient conditions, its adhesion force to porcine skin, glass, and tinplate may reach up to 160, 425, and 275 N/m, respectively. Even stored at −45 or 50 °C for 30 d, the hydrogel still maintains good flexibility and robust adhesion force. It also shows repeatable underwater adhesion to biological tissue, glass, ceramic, plastic, and rubber. This novel antifreezing/antiheating adhesive hydrogel may be applied in extremely cold or hot environments and in underwater conditions.

In nature, shrimp has an outstanding antifouling behavior since its shell possesses underwater superoleophobicity. As a major component of the shrimp shell, chitin might have the potential of self-cleaning and can be exploited for dealing with oily water. Hence, novel filtration membranes derived from shellfish wastes were constructed via filtration of chitin nanofiber suspension. The resultant chitin nanofibrous membrane (CNM) was evaluated as a highly efficient oil/water emulsion separation material for the first time. Similar to shrimp shell, CNM with excellent superhydrophilicity and underwater superoleophobicity displayed extremely low underwater-oil adhesion and self-cleaning performance. With controllable thickness and nanoscale pore size, CNM could effectively separate micrometer- and nanometer-sized oil/water emulsions with a high separation efficiency (>95%) and water flux (>1500 L·m–2·h–1·bar–1). Furthermore, CNM displayed multifunctional water remediation characteristics, i.e., it could simultaneously remove heavy metal ions from water phase in the course of oil/water emulsion separation. The CNM also exhibited excellent mechanical strength, recyclable performance, thermal stability, and pH-resistance. Therefore, CNM with unique characteristics, e.g., sustainability, chemical and thermal resistance, multifunctionality, and excellent oil/water separation efficiency has the high potential in the practical oily water treatment.

Owning to its highly viscous and adhesive properties, viscous crude oil tends to easily adhere onto separation materials, resulting in serious fouling. Herein, we report an ampholytic nanofibrous membrane composed of a pair of oppositely charged biopolymerspositive chitosan (CS) and negative sodium alginate (ALG). CS and ALG were homogeneously complexed with each other to form a well-defined, interconnected, and entangled nanofibrous structure in a cosolvent of the LiOH/KOH/urea aqueous system after sequential treatment with chemical and physical cross-linking reactions. Benefitting from the coexistence of cationic and anionic groups on the surfaces of the CS/ALG composite nanofibers, the resulting CS/ALG composite nanofibrous membrane (CAM) has a strong hydrate layer to repel various oils including viscous crude oil. Moreover, The CAM could retain its wettability in harsh environments (e.g., acid, alkali, and salt). Furthermore, it could effectively separate the most troublesome crude oil-in-water emulsions with a superior separation efficiency (99%) and behaved well in terms of reusability. Meanwhile, CAM could realize multifunctional water treatment, where water-soluble dyes and heavy metal ions could be effectively wiped off by CAM from oily wastewater. The superiorities in low-cost, biodegradability, antioil fouling performance, oil/water separation properties, as well as multifunctional water treatment endow CAM with great potential in dealing with practical oily wastewater treatment.

Serum levels of vitamin A and E in early, middle and late pregnancy were analyzed to evaluate vitamin nutritional status in pregnancy, and provide guidance for pregnant women about vitamin supplements in pregnancy. In total, 28,023 serum samples were randomly selected from pregnant women in early, middle and late pregnancy between January 2013 and June 2014 in Beijing. High performance liquid chromatography (HPLC) method was used to determine the concentration of serum vitamin A and E in pregnancy. The concentration of serum vitamin A in early, middle and late pregnancy was 0.33±0.08, 0.37±0.09 and 0.33±0.15 mg/l, respectively, total abnormal rate was 25.31%, and deficiency (24.98%) was the main feature. The rate of deficiency in the early pregnancy (38.22%) was greater than that in late pregnancy (35.13%). The serum vitamin E in early, middle and late pregnancy was 9.10±2.47, 14.24±3.66 and 15.80±5.01 mg/l, respectively, total abnormal rate was 5.60%, and excess (5.37%) was the main feature. The excess rate in early pregnancy was at the lowest level (0.50%), and reached the highest level (15.32%) in late pregnancy. The serum levels of vitamin A and E are different during pregnancy. Generally, vitamin A is deficient and vitamin E is in excess. Therefore, monitoring the vitamin A and E levels, and strengthening perinatal education and providing guidance for pregnant women to supply vitamins rationally play important role in guaranteeing maternal and fetal safety.

Uncontrollable bleeding and bacterial infection are the two major challenges in treating hemorrhaging civilian and military traumas. Herein, a novel hemostatic material was designed by in situ growth of zinc imidazolate frameworks (ZIF-8) into a chitin sponge (CTS) for effective hemostasis and anti-infection. ZIF-8 nanocrystals were not only uniformly dispersed throughout the CTS but also firmly anchored onto CTS with a residual mass of over 94% after 10 min of sonication. The resultant composite sponge (ZIF-8−CTS) displayed a hierarchically porous structure with a high specific surface area (∼126.2 m 2 •g −1 ) and superhydrophilicity, accelerating blood absorption to concentrate blood cells and platelets to form a primary blood clot. Meanwhile, upon contact with blood, ZIF-8 nanocrystals could gradually release Zn 2+ to activate the blood coagulation cascade reactions. Benefiting from these two synergistic effects, ZIF-8−CTS exhibited superior hemostasis performance than the traditional hemostatic materials (cotton gauze and gelatin sponge) in the rat femoral artery and liver injury models. Furthermore, it displayed excellent cytocompatibility and hemocompatibility. Importantly, it had an outstanding bactericidal effect with antibacterial ratio of up to 100% for Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus. These results demonstrated that ZIF-8−CTS is an excellent antibacterial hemostatic material with a high potential in clinical applications.

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