Biosafety of a 3D-printed intraocular lens made of a poly (acrylamide-co-sodium acrylate) hydrogel in vitro and in vivo

AIM:To assess the biosafety of a poly(acrylamide-cosodium acrylate)hydrogel(PAH)as a 3D-printed intraocular lens(IOL)material.METHODS:The biosafety of PAH was first evaluated in vitro using human lens epithelial cells(LECs)and the ARPE19 cell line,and a cell counting kit-8(CCK-8)assay was performed to investigate alterations in cell proliferation.A thin film of PAH and a conventional IOL were intraocularly implanted into the eyes of New Zealand white rabbits respectively,and a sham surgery served as control group.The anterior segment photographs,intraocular pressure(IOP),blood parameters and electroretinograms(ERG)were recorded.Inflammatory cytokines in the aqueous humor,such as TNFαand IL-8,were examined by ELISA.Cell apoptosis of the retina was investigated by TUNEL assay,and macro PAHge activation was detected by immunostaining.RESULTS:PAH did not slow cell proliferation when cocultured with human LECs or ARPE19 cells.The implantation of a thin film of a 3 D-printed IOL composed of PAH did not affect the IOP,blood parameters,ERG or optical structure in any of the three experimental groups(n=3 for each).Both TNFαand IL-8 in the aqueous humor of PAH group were transiently elevated 1 wk post-operation and recovered to normal levels at 1 and 3 mo post-operation.Iba1+macroPAHges in the anterior chamber angle in PAH group were increased markedly compared to those of the control group;however,there was no significant difference compared to those in the IOL group.CONCLUSION:PAH is a safe material for 3D printing of personal IOLs that hold great potential for future clinical applications.

Two-Photon Absorption and Excited State Dynamics of Two Organic Molecules Containing Donor/Acceptor Moieties

Two new two-photon absorption （TPA） molecules, named SK-G1 and NT-G1, are synthesized and the photo- physical characteristics are investigated by using linear absorption spectra, one-photon fluorescence spectra and two-photon excited fluorescence spectra. Both the compounds exhibit TPA properties, and the TPA values determined by z-scan measurement are 10 GM and 39 GM for SK-G1 and NT-G1, respectively, at wavelength 80Ohm. Time-resolved spectroscopic techniques are employed to further explore the excited state dynamics of NT-G l with larger TPA cross section. The research results show that there is an ultrafast intraband energy transfer process （about 3ps） before the formation of charge transfer state with a relatively long lifetime.

Direct Spatially Resolved Snapshot Interferometric Phase and Stokes Vector Extraction by Using an Imaging PolarCam

We extract the 3 D phase△and the Stokes parameter S3 of a transmissive anisotropic object spatially using an interferometric Polar Cam.Four parallel interferograms with a phase shift ofπ/2 between the images are captured in a single snapshot and then reconstructed by the four-bucket algorithm to extract the 3 D phase of the object.The S3 is then calculated directly from the obtained 3 D phase△.The extracted results of△and S3 were compared with those extracted from the non-interferometric Polar Cam and the Thorlabs polarimeter,and the results match quite well.The merit of using the interferometric Polar Cam is that no mechanical movement mechanisms are included,and hence the△and S3 of the object can be extracted,with high accuracy and within a part of a second(three times faster than non-interferometric Polar Cam and Thorlabs polarimeter methods).Moreover,this method can be applied in the field of the dynamic spectro–interferometric Polar Cam and can be implemented using swept-wavelength approaches.

Mechanism of Silver Nanoparticles Deposition by Electrolysis and Electroless Methods on a Graphite Substrate

This study shows a silver electrodeposition model (EDM) on a graphite substrate. The electrolyte was a 0.01 M solution of pure silver and chromium nitrate using an electrolyzing cell. EDC with current density up to 20 mA/cm2 and 15 mV and pulse current were studied. Results revealed that silver deposited at a rate of 0.515 mg/cm2/min with 12 mA/cm2 that decreases to 0.21 and 0.16 mg/cm2·min with the decrease of current density to 6 and 5 mA/cm2 respectively. The model postulates that silver ions (a) were first hydrated before diffusing (b) from the solution bulk to the cathode vicinity, The next step (c) involved the chemical adsorption of these ions on certain accessible sites of the graphite substrate (anode), The discharged entities (d) adhere to the graphite surface by Van der Vales force. Silver ions are deposited because the discharge potential of silver is low (0.38 mV) as compared to other metal ions like chromium (0.82 mV). Pulse current controls silver deposition due to flexibility in controlling steps (a)-(c) of the deposition mechanisms. Parameters like current density, current on-time, current-off time, duty cycle (ratio of current on time and total pulse time) and pulse frequency influenced the shape and size of the deposits. Step (b) suggested that silver particles were deposited in a monolayer thickness. The silver layer turned multiple after fully satisfying the accessible sites with the monolayer. The activation energy ΔE value amounts to 86.32 kJ/mol/K. At high temperature and current density, homogeneous diffusion occurs.

Soft-Chemical Synthesis of Vanadium Oxide Nanostructures Using 3,3’,3”-Nitrilotripropionic Acid(NTP)as a Carrier

Vanadium oxide nanostructures were synthesized using NTP as a carrier through soft-chemical method. The influence of calcination temperature on the phase and morphology of obtained pristine product were characterized using X-ray diffraction (XRD), thermal gravimetric analysis (TGA) and scanning electron microscopy (SEM). Cyclic voltammogram studies were conducted to examine the electrochemical performance of cathodes made of vanadium oxide nanostructures. X-ray diffraction results show that, the particle size of the nanomaterials is increases with the increasing of calcination temperature.

Catalyst-Free Growth of Nanographene Films on Various Substrates

We have developed a new method to grow uniform graphene films directly on various substrates, such as insulators, semiconductors, and even metals, without using any catalyst. The growth was carried out using a remote plasma enhancement chemical vapor deposition （r-PECVD） system at relatively low temperatures, enabling the deposition of graphene films up to 4-inch wafer scale. Scanning tunneling microscopy （STM） confirmed that the films are made up of nanocrystalline graphene particles of tens of nanometers in lateral size. The growth mechanism for the nanographene is analogous to that for diamond grown by PECVD methods, in spite of sp2 carbon atoms being formed in the case of graphene rather than sp3 carbon atoms as in diamond. This growth approach is simple, low-cost, and scalable, and might have potential applications in fields such as thin film resistors, gas sensors, electrode materials, and transparent conductive films.

A robust,highly reversible,mixed conducting sodium metal anode

Sodium metal anode holds great promise in pursuing high-energy and sustainable rechargeable batteries,but severely suffers from fatal dendrite growth accompanied with huge volume change.Herein,a robust mixed conducting sodium metal anode is designed through incorporating Na SICON-type solid Na-ion conductor into bulk Na.A fast and continuous pathway for simultaneous transportation of electrons and Na+is established throughout the composite anode.The intimate contact between Na-ion conducting phase and Na metallic phase constructs abundant two-phase boundaries for fast redox reactions.Further,the compact configuration of the composite anode substantially protects Na metal from being corroded by liquid organic electrolyte for the minimization of side reactions.Benefiting from the unique configuration,the composite anode shows highly reversible and durable Na plating/stripping behavior.The symmetric cells exhibit ultralong lifespan for over 700 h at 1 mA cm^(-2)with a high capacity of 5 m Ah cm^(-2)and outstanding rate capability up to 8 m A cm^(-2)in the carbonate electrolyte.Full cells with Na_(3)V_(2)(PO_(4))_(3)/C cathode demonstrate impressive cycling stability(capacity decay of 0.012%per cycle)and low charge/discharge polarization as well.This work provides new insights into rational design and development of robust sodium metal anode through an architecture engineering strategy for advanced rechargeable sodium batteries.

Phosphine oxide-functionalized polyfluorene derivatives:Synthesis,photophysics,electrochemical properties,and electroluminescence performance

A series of phosphine oxide-functionalized polyfluorene derivatives,PFH-PO-40-1 (P1),PFH-PO-20-1 (P2),PFH-PO-10-1 (P3),and PFH-PO-1-1 (P4),were prepared via a palladium-mediated Suzuki cross-coupling reaction.The structures and purities of all polymers were fully characterized by 1H and 13C NMR,UV-vis and photoluminescent spectroscopy,gel permeation chromatography,and TGA/DSC.Their emission features showed single broad peaks at about 445 nm in film,compared with those in dilute solutions,which might be caused by some degree of aggregation in the excited states of the backbones.The best electroluminescence (EL) performance of these polymers with configuration of ITO/PEDOT:PSS/Polymer/Alq3/LiF/Al was obtained from P1 (current efficiency was 4.2 Cd/A at 6V).

Dual activation and C-C coupling on single atom catalyst for CO_(2) photoreduction

An excellent single-atomic photocatalyst,Ti@C_(4)N_(3),is theoretically found to effectively convert CO_(2) to C_(2)H_(6) by density functional theory(DFT)calculations and non-adiabatic molecular dynamics(NAMD)simulations.The Ti@C_(4)N_(3) photocatalyst has remarkable stability both thermally,chemically,and mechanically.Electronically,it has strong absorption properties(λ=327.77 and 529.61 nm),suitable band positions,and a long photogenerated electron lifetime(τ_(e)=38.21 ps),allowing photogenerated electrons to migrate to the surface.Notably,the high-valence active site effectively activates two CO_(2) through dual activation:Under light irradiation,the weakly adsorbed CO_(2) undergoes photo-induced activation by the photoelectron of conduction band minimum(CBM);without light,the high Lewis acidity of the Ti site induces CO_(2) activation through back-donatingπ-bond.Contrast simulation results uncovered that dual activation of CO_(2) is attributed to the thermal and photonic synergy.Furthermore,two activated CO_(2) species under light easily couple to form oxalate with the barrier of 0.19 eV,and further reduced to C_(2)H_(6) with a low activation energy of 1.09 eV.