A dual PMMA/calcium sulfate carrier of vancomycin is more effective than PMMA‐vancomycin at inhibiting Staphylococcus aureus growth in vitro

Both antibiotic‐impregnated poly(methyl acrylate, methyl methacrylate) (PMMA) and antibiotic‐impregnated calcium sulfate have been successfully used as local antibiotic delivery vehicles for the management of chronic osteomyelitis. Here, we examined the antibiotic elution characteristics and antibacterial properties of a composite drug delivery system consisting of PMMA/calcium sulfate carrying vancomycin (dual carrier‐v) against Staphylococcus aureus, with PMMA loaded with vancomycin (PMMA‐v) as a control. Vancomycin gradually degraded from dual carrier‐v and PMMA‐v up to about 8 and 6 weeks, respectively. At different elution time points, the inhibition zones of the dual carrier‐v were larger than the inhibition zones of the PMMA‐v (P < 0.05). The colony inhibition rate of the dual carrier‐v was 95.57%, whereas it was 77.87% for PMMA‐v. Scanning electron microscopy was used to demonstrate biofilm formation on the surface of plates treated with vancomycin‐unloaded PMMA, whereas there was no biofilm formation on the surface of plates treated with dual carrier‐v or PMMA‐v. The dual carrier‐v was more effective at antibacterial adhesion at each time point after immersion in simulated body fluid as compared with PMMA‐v (P < 0.05). In conclusion, our results suggest that the dual carrier‐v can release higher concentrations of antibiotics and inhibit bacteria growth more effectively in vitro as compared with PMMA‐v. The dual carrier‐v thus may have potential as an alternative strategy for osteomyelitis management

Effects of alfalfa and organic fertilizer on benzo[a]pyrene dissipation in an aged contaminated soil

BACKGROUND: A climate-controlled pot experiment was conducted to investigate the effects of planting alfalfa and applying organic fertilizer on the dissipation of benzo[a]pyrene from an aged contaminated agricultural soil. RESULTS: Short-term planting of alfalfa inhibited the dissipation of benzo[a]pyrene from the soil by 8.9%, and organic fertilizer enhanced benzo[a]pyrene removal from the soil by 11.6% compared with the unplanted and unfertilized treatments, respectively. No significant interaction was observed between alfalfa and organic fertilizer on benzo[a]pyrene dissipation. Sterilization completely inhibited the removal of benzo[a]pyrene from the soil indicating that its degradation by indigenous microorganisms may have been the main mechanism of dissipation. Furthermore, significant positive relationships were observed between benzo[a]pyrene removal and the contents of soil ammonium nitrogen, nitrate nitrogen, and total mineral nitrogen at the end of the experiment, suggesting that competition between plants and microorganisms for nitrogen may have inhibited benzo[a]pyrene dissipation in the rhizosphere of alfalfa and the addition of organic fertilizer may facilitate microbial degradation of benzo[a]pyrene in the soil

Non-iterative calculation of quasi-dynamic energy flow in the heat and electricity integrated energy systems

Quasi-dynamic energy flow calculation is an indispensable tool for the heat and electricity integrated energy system (HE-IES) analysis. One solves the nonlinear partial differential algebraic equations to obtain thermal, hydraulic and electric variations. However, mainstream iteration solvers face the challenges of inefficiency and bad robustness. For one thing, the frequent update and factorization of Jacobian matrices utilize high CPU time. For another, the per-step iteration numbers grow exponentially as the system loading level creeps up. This paper presents a novel non-iterative algorithm for the quasi-dynamic energy flow calculation. The kernel of the proposed algorithm is to transform these nonlinear equations into linear recursive ones, by solving which, we obtain explicit closed-form solutions of unknown variables. In each step, the proposed algorithm requires only one matrix factorization and fixed times of arithmetic operations regardless of the loading levels, so that it achieves small and consistent per-step time costs. A semi-discrete scheme is used in PDE solution to avoid dissipative and dispersive errors that are often overlooked in previous literature. To ensure convergence, we also propose to control the temporal step sizes adaptively by estimating the simulation errors. Case studies showed that the proposed method manifested efficient and robust time performance compared with the iterative algorithms, and meanwhile preserved high accuracy

High drug loading hydrophobic cross-linked dextran microspheres as novel drug delivery systems for the treatment of osteoarthritis

Drug delivery via intra-articular (IA) injection has proved to be effective in osteoarthritis (OA) therapy, limited by the drug efficiency and short retention time of the drug delivery systems (DDSs). Herein, a series of modified cross-linked dextran (Sephadex, S0) was fabricated by respectively grafting with linear alkyl chains, branched alkyl chains or aromatic chain, and acted as DDSs after ibuprofen (Ibu) loading for OA therapy. This DDSs expressed sustained drug release, excellent anti-inflammatory and chondroprotective effects both in IL-1β induced chondrocytes and OA joints. Specifically, the introduction of a longer hydrophobic chain, particularly an aromatic chain, distinctly improved the hydrophobicity of S0, increased Ibu loading efficiency, and further led to significantly improving OA therapeutic effects. Therefore, hydrophobic microspheres with greatly improved drug loading ratio and prolonged degradation rates show great potential to act as DDSs for OA therapy

Evaluation of a newly developed quantitative heart-type fatty acid binding protein assay based on fluorescence immunochromatography using specific monoclonal antibodies

<div><p><b><i>Objectives.</i></b> To develop a rapid, sensitive and specific assay for quantification of serum heart-type fatty acid binding protein (H-FABP) based on immunofluorescence of specific monoclonal antibodies. <b><i>Design and Methods.</i></b> We generated novel H-FABP-directed monoclonal antibodies by cloning of spleen cells of mice immunized with H-FABP. Epitopes were mapped and antigen affinity was assessed by surface plasmon resonance (SPR). The H-FABP specific monoclonal antibodies were coupled to fluorescent beads and sprayed onto a nitrocellulose membrane facilitating quantification of H-FABP by immunofluorescence. Reagent cross-reactivity, interference resistance, accuracy and sensitivity were examined. A total of 103 clinical samples were used to compare the sensitivity and specificity of the new assay to a commercially available Randox kit. <b><i>Results.</i></b> This new assay could be finished within 15 min, with sensitivity reaching 1 ng/ml. In a trial of 103 clinical serum samples, the new testing kit results were highly correlated with those from the Randox kit (R² = 0.9707). Using the Randox kit as the reference kit, the sensitivity of the new assay was 98.25%, and specificity was 100%. <b><i>Conclusions.</i></b> An immunofluorescence-based H-FABP assay employing novel monoclonal antibodies could rapidly, specifically and sensitively detect H-FABP in serum samples, providing an effective method for rapid clinical assessment of H-FABP index in the clinic.</p></div

Detection Limit of Rapid Diagnostic Test and Real Time RT-PCR for H7N9 isolates.

a<p>State Key Laboratory for Diagnosis and Treatment of Infection Diseases, First Affiliated Hospital, College of Medicine, Zhejiang University.</p>b<p>Beijing #1: Influenza Branch of the Center for Disease Prevention and Control of China.</p>c<p>Beijing #2: Institute of Microbiology and Epidemiology, Academy of Military Medical Sciences (Beijing, China).</p

Analytic sensitivity and specificity of rapid diagnostic test for recombinant hemagglutinin derived from influenza viruses.

<p>*Signal intensity was determined by comparing with a standard color chart and categorized as weak (+, C7–9), moderate (++, C4–6) or strong (+++, C1–3) positivity, respectively. “−” indicates a negative test result.</p

Rapid Diagnostic Test of clinical samples from influenza A(H7N9) positive patients.

<p>Rapid Diagnostic Test of clinical samples from influenza A(H7N9) positive patients.</p