Supramolecular Host-Guest Strategy for the Accelerating Detection of Nitroreductase.

Identifying nitroreductase (NTR) with fluorescent techniques has become a research hotspot, due to its good sensitivity and selectivity toward the early-stage cancer diagnosis and monitoring. Herein, a host-guest reporter (NAQA⊂Zn-MPPB) is successfully achieved by encapsulating the NTR probe NAQA into a new NADH-functioned metal-organic cage Zn-MPPB, which makes the reporter for ultrafast detection of NTR within dozens of seconds in solution. The host-guest strategy fuses the Zn-MPPB and NAQA to form a pseudomolecule material, which changes the reaction process of NTR and NAQA from a double substrates mechanism to a single substrate one, and accelerates the reduction efficiency of NAQA. This advantage make the new host-guest reporter exhibit a linear relationship between emission changes and NTR concentration, and it shows better sensitively toward NTR than that of NAQA. Additionally, the positively charged water-soluble metal-organic cage can encapsulate NAQA in the cavity, promote it to dissolve in an aqueous environment, and facilitate their accumulation into tumor cells. As expected, such host-guest reporter displays a fast and high efficiently imaging capability toward NTR in tumor cells and tumor-bearing mice, and flow cytometry assay is conducted to corroborate the capability as well, implying the considerably potential of host-guest strategy for early tumor diagnosis and treatment.

Efficient removal of hexavalent chromium from water by Bacillus sp. Y2-7 with production of extracellular polymeric substances.

Bioremediation is an environmentally friendly technology for the treatment of chromium-contaminated sites. Here, a hexavalent chromium [Cr(VI)]-resistant strain was isolated from oil-contaminated soil and designated as Bacillus sp. Y2-7 based on 16S rDNA sequence characterization. The effects of various factors including inoculation dose, pH value, glucose concentration, and temperature on Cr(VI) removal rates were then evaluated. Based on the response surface methodology, optimal Cr(VI) removal efficiency (above 90%) could be achieved at an initial Cr(VI) concentration of 155.0 mg·L-1, glucose concentration of 11.479 g·L-1, and pH of 7.1. The potential removal mechanisms of Cr(VI) by strain Y2-7 were also supposed. The contents of polysaccharide and protein in extracellular polymer (EPS) of strain Y2-7 decreased slowly after cultured with Cr(VI) of 15 mg·L-1 from 1 to 7 days. We thus inferred that EPS bonded with Cr(VI) and underwent morphological changes in water. Molecular operating environment (MOE) analysis suggested that macromolecular protein complexes in Bacillus sp. Y2-7 and hexavalent chromium could establish hydrogen bonds. Collectively, our findings indicate that Bacillus sp. Y2-7 is an excellent bacterial candidate for chromium bioremediation.

Multi-walled carbon nanotube-modified hydrothermal carbon: A potent carbon material for efficient remediation of cadmium-contaminated soil in coal gangue piling site.

Coal gangue contains numerous metal ions. After rainwater leaching, the metal ions in coal gangue migrate into the surrounding soil, posing significant threats to human health and ecosystems. To remove Cd from contaminated soil surrounding a coal gangue pile area, loofah, oak chips, and corn stalks were used as raw materials to prepare loofah hydrothermal carbon (LH), oak chip hydrothermal carbon (OH), corn stalk hydrothermal carbon (CH). Next, LH, OH, and CH were modified using multiwalled carbon nanotubes (MWCNTs) to obtain loofah-, oak-chip-, and corn-stalk-MWCNTs hydrothermal carbon composites (LMH, OMH, and CMH). The loofah hydrothermal carbon with excellent pore structure, specific surface area and pore capacity was selected, and the loading of MWCNTs was varied to give it better adsorption performance. The N2 adsorption-desorption experiments showed that the specific surface area and pore volume of LMH, OMH and CMH were significantly higher than those of LH, OH and CH, respectively. The specific surface area and pore volume of LMH are 101.948 m2 g-1 and 6.226 cm3 g-1, respectively. By EDS analysis and infrared spectroscopy, it can be seen that LMH has more o-containing functional groups than OMH and CMH. Remediation experiments were carried out on the actual contaminated soil obtained from Chaili Coal Mine. It was found that the mass fractions of Cd in the acid-soluble state in the soil samples that were treated with LH and LMH decreased by 18.54% and 26.3%, respectively, after 20 d. Therefore, LMH significantly affected Cd fixation and promoted Cd pollution remediation in the coal gangue pile area.

Immune-related expression profiles of bisphosphonates-related osteonecrosis of the jaw in multiple myeloma.

Objective: To investigate the immune cellular and genomic profiles of bisphosphonates-related osteonecrosis (BRONJ) of the jaw and excavate potential small molecule drugs. Methods and materials: The genomic profile of a multiple myeloma (MM) patient with BRONJ was downloaded from Gene Expression Omnibus (GEO). The 22 immune cell subsets infiltration in the patient were predicted by cell-type identification by estimating relative subsets of RNA transcripts. In addition, the differently expressed immune-related genes (DEMGs) of BRONJ were identified, followed by Gene Ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses for functional annotation. Then, potential drugs for BRONJ treatment were predicted by Connectivity Map (CMAP) based on DEGs. Results: High proportions of native CD4+T cells and M0 macrophages were observed while resting mast cells, NK cells, and eosinophils were downregulated in the BRONJ patient (P< 0.05). Resting dendritic cells and gamma delta T cells were positively correlated (r=0.93). Additionally, 36 DEMGs were screened from 336 DEGs in BRONJ expression profiles. GO enrichment analysis revealed that DEMGs were most associated with peptidyl-tyrosine modification, myeloid leukocyte migration, leukocyte chemotaxis and regulation of chemokine production(P<0.05). KEGG analysis indicated that DEMGs were mainly related to cytokine-cytokine receptor interaction, IL-17 signaling pathway and NF-Kappa B signaling pathway(P<0.05). Besides, 12 small molecule drugs were screened in MM patient with ONJ. Conclusion: The discovery of different composition of immune cell types and immune-related transcriptomes in BRONJ helps to explain the onset and development of MRONJ, which provides a novel target for BRONJ therapy.

Metathesis of Mg2FeH6 and LiNH2 leading to hydrogen production at low temperatures.

Mg2FeH6 with a purity of up to 94.5 wt% was synthesized and its interaction with LiNH2 was investigated in this study. It was found that Li4FeH6, normally synthesized by hydriding a mixture of LiH and Fe at 700 °C and 5.5 GPa H2 pressure, can be formed via ball-milling Mg2FeH6 and LiNH2 under ambient conditions following the reaction of Mg2FeH6 + 4LiNH2 → Li4FeH6 + 2Mg(NH2)2, ΔH = -92.8 kJ mol-1. The formation of Li4FeH6 was confirmed by XRD, FTIR and Mössbauer spectroscopic characterization. Li4FeH6 further reacts with 2Mg(NH2)2 releasing ca. 4.8 wt% H2 at 225 °C and reabsorbing 3.7 wt% H2 at 200 °C and 50 bar H2 pressure. Mg(NH2)2, LiH and Fe are the hydrogenated products.