Innovative spectral investigations on the thermal-induced poly(aspartic acid)

Dual Crosslinking Hydrogels with Tunable Injectability and Stability for Bone Repair

As an ideal biomaterial, the injectable dual crosslinking hydrogels can fill irregular shaped defects for treating bone defects. Despite advances in the fabrication of injectable dual crosslinking hydrogels, current methods...

Synthesis of amphiphilic polysuccinimide star copolymers for responsive delivery in plants

While polymeric nanocarriers are widely used in medicine for controlled release and site-specific delivery, few reports have applied such delivery methods within agriculture, despite the urgent need for specific delivery of pesticides and nutrients. We report the synthesis of stimuli-responsive and biodegradable polymeric nanocarriers designed for delivery to the phloem of plants and describe methods employed to evaluate their toxicity in plant cells.

Spectral Exploration of Calcium Accumulation in Organic Matter in Gray Desert Soil from Northwest China

Little attention has been paid to the accumulation of soil organic matter (SOM) in the fringes of the mid-latitude desert. In this paper, soil samples from a long-term field experiment conducted from 1990 to 2013 at a research station in Urumqi, China by different fertilizer treatments, were used to determine soil properties and soil dissolved organic matter (DOM) by chemical analysis, fluorescence excitation emission matrix (EEM) spectroscopy, and high resolution-transmission electron microscopy (HR-TEM). The binding features of DOM under the addition of Ca(2+) were analyzed using a two-dimensional (2D) Fourier transform infrared (FTIR) spectrometer further to explore the response of the DOM to increasing concentrations of Ca(2+). Long-term application of chemical fertilizers and goat manure increased soil organic carbon (SOC) by 1.34- and 1.86-fold, respectively, relative to the non-fertilized control (8.95 g.kg(-1)). Compared with the control, application of chemical fertilizers and manure significantly increased the concentrations of Ca, Mg, Si, humic and fulvic acid-like substances in DOM but decreased the amounts of trivalent metals (Al and Fe) and protein-like substances. Although crystalline Al/Fe nanoparticles and amorphous or short-range-order Si/Al nanoparticles existed in all DOM samples, crystalline Ca/Si nanoparticles were predominant in the samples treated with goat manure. Although organic matter and Si-O-containing nanoparticles were involved in the binding of Ca(2+) to DOM, application of chemical fertilizers weakened Ca(2+) association with components of the amide II group (1510 cm(-1)) and Si-O linkage (1080 cm(-1)), whereas application of goat manure enhanced the affinity of Ca(2+) for Si-O linkage. Our results suggested that the enrichment of Ca in gray desert soil possibly helps accumulate SOM by forming crystalline Ca/Si nanoparticles in addition to Ca(2+) and organic matter complexes.

Effects of nitrogen-dopants on Ru-supported catalysts for acetylene hydrochlorination

A series of N-doped spherical active carbons were synthesizedviathe pyrolysis of melamine in activated carbon, and used as a support to prepare Ru-based catalysts for an acetylene hydrochlorination reaction.

Biomimetic synthesis of struvite with biogenic morphology and implication for pathological biomineralization

Recent studies have found that certain urinary proteins can efficiently inhibit stone formation. These discoveries are significant for developing effective therapies for stone disease, but the inhibition mechanism of crystallization remains elusive. In the present study, polyaspartic acid (PASP) was employed as a model peptide to investigate the effect of urinary proteins on the crystallization and morphological evolution of struvite. The results demonstrate that selective adsorption/binding of PASP onto the {010} and {101} faces of struvite crystals results in arrowhead-shaped morphology, which further evolves into X-shaped and unusual tabular structures with time. Noticeably, these morphologies are reminiscent of biogenic struvite morphology. Concentration-dependent experiments show that PASP can inhibit struvite growth and the inhibitory capacity increases with increasing PASP concentration, whereas aspartic acid monomers do not show a significant effect. Considering that PASP is a structural and functional analogue of the subdomains of aspartic acid-rich proteins, our results reveal that aspartic acid-rich proteins play a key role in regulating biogenic struvite morphology, and aspartic acid residues contribute to the inhibitory capacity of urinary proteins. The potential implications of PASP for developing therapeutic agents for urinary stone disease is also discussed.

Clinoptilolite nano-particles modified with aspartic acid for removal of Cu(ii) from aqueous solutions: isotherms and kinetic aspects

Clinoptilolite nano-particles modified with aspartic acid can remove Cu(ii) cations by ion exchange and complexation processes.