Aggregation-Induced Near-Infrared Emission and Electrochemiluminescence of an Iridium(III) Complex for Ampicillin Sodium Sensing.

A new iridium(III) complex was synthesized and characterized. Its photophysical properties and aggregation-induced emission and electrochemiluminescence in the near-infrared range were studied. The large conjugated cyclometallic ligand 1,2-phenylbenzoquinoline (pbq) was selected to form the Ir-C bond with the metal iridium(III) center and provide near-infrared emission of the complex. The auxiliary ligand 4,4'-diamino-2,2'-bipyridine (dabpy) can form hydrogen bonds, which was beneficial for the generation of aggregation-induced emission. The complex was aggregated into small spherical nanoparticles in 80% water and fascinating nanorings in 90% water. The sensing of ampicillin sodium (AMP) antibiotic by the iridium(III) complex were also investigated by photoluminescent and electrochemiluminescent methods. The complex showed a good selectivity toward AMP antibiotic compared to sodium phenylacetate and other eight antibiotics. The detection limits for AMP antibiotic was 0.76 µg/mL. This work provided a new strategy for the design of iridium(III) complex-based aggregation-induced emission and electrochemiluminescence probes for the sensing application.

Avascular necrosis under different treatment in children with developmental dysplasia of the hip: a network meta-analysis.

The objective of this study was to evaluate the incidence of avascular necrosis (AVN) of the femoral head in children less than 3 years of age with developmental dysplasia of the hip (DDH) treated with closed reduction, open reduction alone and open reduction combined with osteotomy. We reviewed clinical trials from the PubMed, EMBASE and Cochrane Library databases (up to November 2020) that were related to closed reduction, open reduction alone and open reduction combined with osteotomy for the treatment of children under 3 years of age with DDH. The screening and quality evaluation of the literature were performed independently by two researchers. In case of disagreement, a third researcher resolved the discourse. Finally, the data were extracted, and the R software and GeMTC program package were used to conduct a network meta-analysis (NMA). The evaluation index was the incidence of AVN. Fourteen articles were included. The NMA showed that in terms of the incidence of AVN, cases treated with open reduction alone were higher than those with closed reduction, and the difference was statistically significant. Open reduction alone had the highest probability (94.4%) of having the highest incidence of AVN, followed by open reduction combined with osteotomy (5.5%) and closed reduction (0.1%). In the treatment of children with DDH who are younger than 3 years old, open reduction alone is most likely to be the treatment with the highest incidence of AVN, followed by open reduction combined with osteotomy. The closed reduction had the smallest probability of AVN.

3D simulation of radiographic projections to test and reduce the effect of pelvic tilt on the accuracy of cross-table lateral radiography.

BACKGROUND: Cross-table lateral (CL) radiography is a convenient and feasible method to assess cup version angle (VA) after total hip arthroplasty; However, pelvic tilt (PT) may contribute to its measurement inaccuracy. How PT affects CL radiographic measurements have not been well studied. We sought (1) to determine the effect of the PT on cup version measurement on CL radiography and (2) to develop a method for reducing measurement errors caused by the PT. METHODS: We used 3D technique to construct standard model and capture CL radiography simulation. A linear regression model was created to analyze the relationship between PT and VA. CL radiography and computed tomography (CT) were performed for the enrolled patients after surgery. The consistency between CL and CT measurements were verified by intra-class correlation coefficient (ICC). RESULTS: There was a high correlation between the VA and PT. For each 1-degree increased in the PT, the VA decreased by 0.76° (R2 = 0.995, p < 0.001). Based on the data, we created a corrective formula to convert the radiographic measurements into values approximating the actual VA under a natural pelvic position. The VA measurements corrected by our equation was in high agreement with the CT-measured values with reference to the corresponding PT (ICC = 0.988, p < 0.001), which was in sharp contrast to that without PT control (ICC = 0.454, p = 0.203). CONCLUSIONS: The PT may contribute to cup version measurement inaccuracies on CL radiography. Our mathematical algorithm can serve as a reliable method to improve the accuracy of CL radiography.

Exosomal lncRNAs NONMMUT000375.2 and NONMMUT071578.2 derived from titanium particle treated RAW264.7 cells regulate osteogenic differentiation of MC3T3-E1 cells.

Periprosthetic osteolysis and the subsequent aseptic loosening can lead to the failure of joint replacement. Wear particles are well known to be the initiative cause inducing osteolysis through enhancing osteoclast-mediated bone resorption and reducing osteogenic differentiation. The purpose of this study was to investigate the effects of osteoclast-secreted exosomal long noncoding RNAs (lncRNAs) on osteogenesis in the process of particle-induced osteolysis. RAW264.7 cells were treated by titanium particles (TI). The inflammatory cytokines were increased, and expression of Receptor Activator of Nuclear Factor-κB and Nuclear factor of activated T cells c1 were also increased, indicating osteoclast differentiation occurred. The purified exosomes from RAW264.7 cells induced with TI inhibited osteogenic differentiation of MC3T3-E1 cells. RNA sequencing generated lncRNAs expression profiles (458 up-regulated and 1641 down-regulated) of the exosomes derived from RAW264.7 cells treated with TI. Based on the results of gene ontology/Kyoto Encyclopedia of Genes and Genomes analysis and quantitative real time polymerase chain reaction validation, we confirmed two candidate lncRNAs, NONMMUT000375.2 and NONMMUT071578.2. The regulation network presented that some vital genes involved in osteoclast differentiation, such as Bcl2, Wnt11, TGF-ß, and Pdk1, were under the regulation of NONMMUT000375.2 and NONMMUT071578.2. Taken together, exosomes derived from TI treated RAW264.7 cells inhibit the osteogenic activity of MC3T3-E1 cells. Exosomal lncRNAs, NONMMUT000375.2 and NONMMUT071578.2 may potentially play their roles in promoting osteoclast differentiation and suppressing osteogenesis, which aggravates the osteoclastogenesis/osteogenesis imbalance.

Chain structure and immunomodulatory activity of a fructosylated chondroitin from an engineered Escherichia coli K4.

Polysaccharide K4 expressed from E. coli K4 has a similar structure with chondroitin, which can be used as a precursor to produce chondroitin sulfates. Here, we investigated the structure, conformation and biological activity of K4 from an engineered strain with high productivity. The NMR analysis suggested that K4 from wild-type strain with a low yield was a partially fructosylated chondroitin. While K4 from engineered strain was a fully fructosylated chondroitin. Light scattering analysis gave the Mw values of 6.15 × 104, 8.23 × 104 and 1.92 × 104 for K4-1, K4-2 and defructosylated K4 (DK4), respectively. The exponents of functions z1/2 = f(Mw) were in the range of 0.643-0.608, suggesting a random coil conformation for K4 and DK4. And the random coils K4 easily self-assembled into sphere-like aggregates in the dilute aqueous solution. Both K4 and DK4 exhibited significant immunomodulatory activities on RAW 264.7 cells at the dosage range of 5-500 µg/mL.

Expression and characterization of an enhanced recombinant heparinase I with chitin binding domain.

Heparinase I (Hep I) can efficiently depolymerize heparin and heparin sulfate to oligosaccharides or unsaturated disaccharides, which resulted in loss of physiological function such as blood coagulation. In order to realize the immobilization of Hep I on chitin carriers, we cloned Hep I with the chitin binding domain (ChBD) as a chitin-affinity tag, and the Small Ubiquitin-like MOdifier (SUMO) linker as a solvation enhancer in different fusion sequence. DNA and protein gels suggested that 4 kinds of recombinants were successfully constructed and expressed in Escherichia coli (E. coli). And the triple functional heparinases isolated from cell lysate could be efficiently purified by chitin beads. After optimizing fermentation conditions, it gave the specific enzyme activities of 1.88±0.11, 3.69±0.45, 3.44±0.38, and 2.73±0.29IU/mg total proteins for ChBD-Hep I, ChBD-SUMO-Hep I, SUMO-ChBD-Hep I, and ChBD-Hep I-SUMO, respectively, with unfractionated heparin as substrate. The optimal reaction temperature and pH were determined to be 30°C and 7.0 for all the fusion enzymes. ChBD-SUMO-Hep I exhibited the maximum half-life (48min) at 30°C and best thermo-stability under 15-50°C. All the fusion enzymes showed broad pH-stability in the range of 5.4-9.0.