Polymeric ionic liquid-assembled graphene-immobilized silica composite for selective isolation of human serum albumin from human whole blood.

Polymeric ionic liquids (PILs) with 1-vinyl-3-ethylimidazolium cations and two different anions of Br- and PF6- were assembled onto the surface of graphene (G) nanosheets. The derived two composites, i.e., PIL(Br)-G and PIL(PF6)-G, were further efficiently immobilized onto the surface of silica nanoparticles via self-assembly technique. The obtained two PIL-G/SiO2 nanocomposites exhibited diverse adsorption performances toward proteins through adjusting the anions of PILs. Electrostatic attractions between proteins and the nanocomposites dominated protein adsorption, while the presence of PF6- anions weakened electrostatic interactions and deteriorated the selective adsorption of target protein, i.e., bovine serum albumin (BSA) in this case. Specifically, PIL(Br)-G/SiO2 nanocomposite displayed high selectivity toward BSA and a high adsorption efficiency of ca. 98% was achieved for 100 mg L-1 BSA in a Britton-Robinson (B-R) buffer at pH 5. HPLC analysis demonstrated the selectivity of PIL(Br)-G/SiO2 nanocomposite toward BSA in the presence of abundant hemoglobin and cytochrome c. The practical applicability was verified by performing selective isolation of human serum albumin (HSA) from human whole blood. Graphical abstract Selective isolation of human serum albumin from blood by polymeric ionic liquid assembled graphene immobilized silica nanocomposite with tunable anions.

Tunable composites prepared from graphene oxide and zeolitic imidazolate framework-8 for improved selective isolation of hemoglobin.

The authors report on the preparation of composites made from graphene oxide (GO) and zeolitic imidazolate framework-8 (ZIF-GO), with various fractions of GO. GO acts as the template and as a modulator for the surface properties of the composites. It also improves the selective adsorption of specific proteins, i.e. hemoglobin (Hb) in this case. The adsorption capacity for Hb is as high as 436 mg g-1 when using a composite containing 20% of GO as sorbent, and 95% of specific activity is maintained for the Hb recovered. The sorbent is applied to selectively isolate Hb from human whole blood. Graphical abstract Graphene oxide-zeolitic imidazolate framework-8 composites (ZIF-GO) with varying mass ratios of GO were prepared in order to tune surface properties and to improve the adsorption selectivity toward hemoglobin.

Effects of harvest time and added molasses on nutritional content, ensiling characteristics and in vitro degradation of whole crop wheat.

OBJECTIVE: Wheat is an alternative to corn silage for ruminant feeding in northern China. This study examined the effects of harvest time and added molasses on nutritional content, ensiling characteristics and in vitro degradation of whole crop wheat (WCW). METHODS: Fresh WCW at the milk-ripe stage was harvested at 0700 h (i.e., in the morning [Mo]) and 1700 h (i.e., in the afternoon [Af]), and then immediately used to prepare silage and make hay. Commercial molasses was added to Af WCW at 0%, 2%, 4%, and 6% (fresh weight) proportions. The WCW treated with molasses was mixed thoroughly prior to ensiling. RESULTS: Dry matter (DM), neutral detergent fiber, water soluble carbohydrate (WSC) content (p<0.01), accumulative gas production in 72 h (GP72h, 77.46 mL/g vs 95.15 mL/g) and dry matter disappearance in vitro (69.15% vs 76.77%) were lower (p<0.05), while crude protein (CP) content was higher for WCW silage (WCWS) compared to WCW (p<0.01). The propionic acid and butyric acid concentrations in WCWS from Mo WCW were 1.47% and 0.26%, respectively. However, the propionic and butyric acid concentrations were negligible, while the ammonia nitrogen/total nitrogen (NH3-N/TN, p<0.01) concentration was lower and the rate of gas production at 50% of the maximum (17.05 mL/h vs 13.94 mL/h, p<0.05) was higher for Af WCWS compared to Mo WCWS. The incubation fluid's NH3-N concentration was lower in WCWS and Af WCW compared to Mo WCW (p<0.05). The CP and WSC content increased with increasing molasses levels (p<0.05). Furthermore, the pH (p<0.01) and time when gas production was 50% of the maximum (2.78 h vs 3.05 h, p<0.05) were lower in silage treated with 4% molasses than silage without molasses. CONCLUSION: Harvesting wheat crops in the afternoon and adding molasses at 4% level to WCW optimally improved ensiling characteristics, leading to well-preserved silage.

Metal affinity-carboxymethyl cellulose functionalized magnetic graphene composite for highly selective isolation of histidine-rich proteins.

A metal affinity-carboxymethyl cellulose functionalized magnetic graphene, namely MGCI-Cu composite, was prepared by successive modifications of graphene oxide nanosheets with magnetic nanoparticles, carboxymethyl cellulose (CMC), iminodiacetic acid (IDA) and then chelated with copper ions. The successful modifications of the graphene surface were demonstrated by various characterizations, and a high density of 6.17 µmol m-2 for metal affinity groups was obtained. The composite exhibited high adsorption selectivity toward histidine-rich proteins. The adsorption was governed by strong metal affinity binding force between hisitidine residues of proteins and immobilized Cu2+ ions of MGCI-Cu composite. In particular, highly selective isolation of hemoglobin (Hb) was achieved in 0.2 mol L-1 phosphate buffer at pH 8. The adsorption capacity of Hb significantly increased to 769 mg g-1 in comparison to that of 435 mg g-1 on metal affinity modified magnetic graphene composite (MGI-Cu) without CMC modification. The adsorbed Hb molecules were recovered with a carbonate buffer (0.2 mol L-1 pH 10) containing 0.5 mol L-1 imidazole. MGCI-Cu composite displayed favorable reusability for at least four times after regeneration of the composite by edetic acid (EDTA) and Cu2+ solution. The practical applications demonstrated that MGCI-Cu composite could highly selectively isolate Hb from human whole blood and polyhistidine-tagged recombinant protein from Escherichia coli (E. coli) lysate.

Effects of replacing Leymus chinensis with whole-crop wheat hay on Holstein bull apparent digestibility, plasma parameters, rumen fermentation, and microbiota.

Twelve Holstein bulls were used in a 4 × 4 Latin square design to investigate the effects of using whole-crop wheat hay (WCWH) as a substitute for Leymus chinensis (LC) on apparent digestibility, plasma parameters, ruminal fermentation, and microbial communities. Experimental treatments were four proportions of WCWH, 0, 33, 67, and 100%, as a substitute for LC (WCWH0, WCWH33, WCWH67, and WCWH100, respectively). The WCWH100 group showed a higher nutritional intake of crude protein (CP) and higher apparent digestibility of organic matter (OM), CP, and ether extract (EE) than the WCWH0 group (P < 0.05). Urea N, NH3-N, isobutyrate and isovalerate levels were higher (P < 0.05) in the WCWH100 group than in the WCWH0 group. 16S rRNA high-throughput sequencing analysis revealed similarities in the community composition, species diversity and relative abundance of dominant bacteria at the phylum and genus levels among the four groups. Collectively, our data indicated that WCWH can be used to replace LC in the diet of finishing dairy bulls without having a negative impact on apparent digestibility, plasma parameters, and ruminal bacteria composition. These results offer the first deep insight into the effects of replacing LC with WCWH on the performance parameters and rumen microbiota in Holstein bulls, and may aid in ruminant farming.