Theory-Driven Tailoring of the Microenvironment of Quaternary Ammonium Binding Sites on Electrospun Nanofibers for Efficient Bilirubin Removal in Hemoperfusion.

Efficient adsorbents for excess bilirubin removal are extremely important for the treatment of hyperbilirubinemia. However, traditional adsorbents, such as activated carbons and ion-exchange resins, still suffer from dissatisfactory adsorption performance and poor blood compatibility. Herein, we adopted a rational design strategy guided by density functional theory (DFT) calculations to prepare blood-compatible quaternary ammonium group grafted electrospun polyacrylonitrile nanofiber adsorbents. The calculation analysis and adsorption experiments were used to investigate the structure-function relationship between group types and bilirubin adsorption, both indicating that quaternary ammonium groups with suitable configurations played a crucial role in bilirubin binding. The obtained nanofiber adsorbents showed the bilirubin removal efficiency above 90% even at a coexisting BSA concentration of 50 g L-1. The maximum adsorption capacities were 818.9 mg g-1 in free bilirubin solution and 163.7 mg g-1 in albumin bound bilirubin solution. The nanofiber adsorbents also showed considerable bilirubin removal in dynamic adsorption to reduce the bilirubin concentration to a normal level, which was better than commercial activated carbons. Our study demonstrates the high feasibility of a theory-driven design method for the development of grafted electrospun nanofibers, which have good potential as bilirubin adsorbents in hemoperfusion applications.

High-efficiency and economical uranium extraction from seawater with easily prepared supramolecular complexes.

Developing effective adsorbents for uranium extraction from natural seawater is strategically significant for the sustainable fuel supply of nuclear energy. Herein, stable and low-cost supramolecular complexes (PA-bPEI complexes) were facilely constructed through the assembly of phytic acid and hyperbranched polyethyleneimine based on the multiple modes of electrostatic interaction and hydrogen bonding. The PA-bPEI complexes exhibited not only high uptake (841.7 mg g-1) and selectivity (uranium/vanadium selectivity = 84.1) toward uranium but also good antibacterial ability against biofouling. Mechanism analysis revealed that phosphate chelating groups and amine assistant groups coordinated the uranyl ions together with a high affinity. To be more suitable for practical applications, powdery PA-bPEI complexes were compounded with sodium alginate to fabricate various macroscopic adsorbents with engineered forms, which achieved an extraction capacity of 9.0 mg g-1 in natural seawater after 50 days of testing. Impressively, the estimated economic cost of the macroscopic adsorbent for uranium extraction from seawater ($96.5 âˆ¼ 138.1 kg-1 uranium) was lower than that of all currently available uranium adsorbents. Due to their good uranium extraction performance and low economic cost, supramolecular complex-based adsorbents show great potential for industrial uranium extraction from seawater.

Poly-ß-cyclodextrin strengthen Pr6O11 porous oxidase mimic for dual-channel visual recognition of bioactive cysteine and Fe2.

To conveniently monitor bioactive cysteine (Cys) and Fe2+ in practice, a kind of poly-ß-cyclodextrin strengthen praseodymium oxide (Pr6O11) porous oxidase mimic (p-ß-CD@Pr6O11) was constructed by virtue of the strong coordination between nano Pr6O11 and poly-ß-cyclodextrin substrate. After its microstructure and physicochemical property were characterized in detail, it was noted that porous p-ß-CD@Pr6O11 exhibited excellent enzyme-like catalytic activity to accelerate the oxidation of 3,3',5,5,'-tetramethylbanzidine (TMB) and 2,2'-azinobis (3-ethylbenzo-thiazoline-6-sulfonic acid) ammonium salt (ABTS) with significant color-enhancement effect in the air. Based on the signal amplification, trace Cys could exclusively deteriorate the UV-vis absorbance at 653 nm of p-ß-CD@Pr6O11-TMB and Fe2+ alter the one at 729 nm of p-ß-CD@Pr6O11-ABTS with visual color changes. Under the optimized conditions, the proposed p-ß-CD@Pr6O11-TMB and p-ß-CD@Pr6O11-ABTS systems were successfully applied for dual-channel monitoring of Cys in Cys capsules and fetal bovine serum and Fe2+ in agricultural products with quite low detection limits, i.e., 7.8×10-9 mol·L-1 for Cys and 6.93×10-8 mol·L-1 (S/N=3) for Fe2+, respectively. The synergetic-enhancement detection mechanisms to Cys and Fe2+ were also proposed.

Rapid and sensitive detection of potato virus Y by isothermal reverse transcription-recombinase polymerase amplification assay in potato.

In this study, an isothermal reverse transcription-recombinase polymerase amplification (RT-RPA) assay was developed for the efficient and accurate detection of potato virus Y (PVY) under isothermal conditions. This RT-RPA assay was more efficient than the conventional reverse transcription-polymerase chain reaction (RT-PCR) assay as the amplification reaction can be completed in less than 20 min. Moreover, unlike PCR that requires a thermocycler to carry out the DNA amplification through specific temperature phases, RPA assay could be performed under an isothermal condition at a temperature ranging from 25 to 40 °C. A simple instrumentation such as a heating block or a water bath or even anon-instrumental condition such as human hands or a benchtop inside/outside a room during the summer could satisfy the temperature requirement of RPA. The sensitivity of this assay was equivalent to that of the conventional RT-PCR, and the virus can be detected in a minimum of 2 pg of total RNA extracted from the PVY infected potato leaf tissues. The efficacy of the newly developed RT-RPA was then evaluated using field potato leaf and dormancy-broken sprout samples upon enzyme-linked immunosorbent assay (ELISA) screening. Of the 164 PVY-ELISA-positive samples, RT-RPA detected 157 whereas simplex RT-PCR detected 160 and multiplex RT-PCR detected 154. Of the 74 randomly selected PVY-ELISA-negative samples, RT-RPA, simplex RT-PCR and multiplex RT-PCR led to 1, 1 and 0 positive detections, receptively. Overall, RT-RPA and the two RT-PCR assays as well as ELISA exhibited an agreement of 96.6-98.7%, thus demonstrating the suitability of RT-RPA for large scale detection of PVY, irrespective of the strain type of the virus.

An Energy-Efficient Implantable-Neural-Stimulator System with Wireless Charging and Dynamic Voltage Output.

Neural stimulators have become more and more widely used as an effective tool in neural therapies. To address power supply and consumption issues in this application, an energy-efficient Implantable-Neural-Stimulator system composed of a pulse generator and a wireless charger is proposed and implemented in 0.8µm 40V Bipolar-CMOS-DMOS (BCD) process. By adopting a Single Ended Primary Inductor Converter (SEPIC) and optimizing the switching frequency and the gate width of its power MOSFET, the stimulating output voltage range can cover 0~12V with a maximum output ripple of 0.31%. The proposed charger can charge the implantable battery wirelessly by an inductively coupled resonance circuit. In addition, it can adjust the charging voltage to keep it constantly only a little higher than the battery voltage, which reduces the charging headroom voltage and greatly improves the charging efficiency. The measured maximum power efficiencies of these two modules reach as high as 78.04% and 70.67%, respectively.