scholarly journals A Transformative Gold Patterning through Selective Laser Refining of Cyanide

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1921
Author(s):  
Jaemook Lim ◽  
Jimin Ham ◽  
Woohyun Lee ◽  
Eunseung Hwang ◽  
Won Chul Lee ◽  
...  
Keyword(s):  
Repair Process ◽  
Gold Electrodes ◽  
Proof Of Concept ◽  
Direct Writing ◽  
Gold Cyanide ◽  
Thermocapillary Force ◽  
Synthesis Time ◽  
Frequent Use ◽  
Transformative Approach ◽  
Nanoparticle Ink

Gold is an essential noble metal for electronics, and its application area is increasing continuously through the introduction of gold nanoparticle ink that enables rapid prototyping and direct writing of gold electrodes on versatile substrates at a low temperature. However, the synthesis of gold nanoparticles has certain limitations involving high cost, long synthesis time, large waste of material, and frequent use of chemicals. In this study, we suggest simultaneous laser refining of gold cyanide and selective fabrication of gold electrodes directly on the substrate without a separate synthesis step. Gold cyanide is commonly the first product of gold from the primitive ore, and the gold can be extracted directly from the rapid photothermal decomposition of gold cyanide by the laser. It was confirmed that laser-induced thermocapillary force plays an important role in creating the continuous gold patterns by aligning the refined gold. The resultant gold electrodes exhibited a low resistivity analogous to the conventional direct writing method using nanoparticles, and the facile repair process of a damaged electrode was demonstrated as the proof-of-concept. The proposed transformative approach for gold patterning, distinguished from the previous top-down and bottom-up approaches, has the potential to replace the well-known techniques and provide a new branch of electrode manufacturing scheme.

scholarly journals Radiosynthesis of [18F]-Labelled Pro-Nucleotides (ProTides)

Molecules ◽  
2020 ◽  
Vol 25 (3) ◽  
pp. 704
Author(s):  
Alessandra Cavaliere ◽  
Katrin C. Probst ◽  
Stephen J. Paisey ◽  
Christopher Marshall ◽  
Abdul K. H. Dheere ◽  
...  
Keyword(s):  
Total Synthesis ◽  
Pet Imaging ◽  
Early Stage ◽  
Proof Of Concept ◽  
Synthesis Time ◽  
Positron Emission ◽  
Anti Cancer ◽  
Radiochemical Yields ◽  
Radiochemical Synthesis

Phosphoramidate pro-nucleotides (ProTides) have revolutionized the field of anti-viral and anti-cancer nucleoside therapy, overcoming the major limitations of nucleoside therapies and achieving clinical and commercial success. Despite the translation of ProTide technology into the clinic, there remain unresolved in vivo pharmacokinetic and pharmacodynamic questions. Positron Emission Tomography (PET) imaging using [18F]-labelled model ProTides could directly address key mechanistic questions and predict response to ProTide therapy. Here we report the first radiochemical synthesis of [18F]ProTides as novel probes for PET imaging. As a proof of concept, two chemically distinct radiolabelled ProTides have been synthesized as models of 3′- and 2′-fluorinated ProTides following different radiosynthetic approaches. The 3′-[18F]FLT ProTide was obtained via a late stage [18F]fluorination in radiochemical yields (RCY) of 15–30% (n = 5, decay-corrected from end of bombardment (EoB)), with high radiochemical purities (97%) and molar activities of 56 GBq/μmol (total synthesis time of 130 min.). The 2′-[18F]FIAU ProTide was obtained via an early stage [18F]fluorination approach with an RCY of 1–5% (n = 7, decay-corrected from EoB), with high radiochemical purities (98%) and molar activities of 53 GBq/μmol (total synthesis time of 240 min).

scholarly journals Combination of a Collagen Scaffold and an Adhesive Hyaluronan-Based Hydrogel for Cartilage Regeneration: A Proof of Concept in an Ovine Model

Cartilage ◽  
2021 ◽  
pp. 194760352198941
Author(s):  
Clara Levinson ◽  
Emma Cavalli ◽  
Brigitte von Rechenberg ◽  
Marcy Zenobi-Wong ◽  
Salim E. Darwiche
Keyword(s):  
Collagen Scaffold ◽  
Cartilage Regeneration ◽  
Repair Process ◽  
Single Step ◽  
Surrounding Tissue ◽  
Proof Of Concept ◽  
Ovine Model ◽  
Stifle Joint ◽  
Adjacent Cartilage

Objective Hyaluronic acid–transglutaminase (HA-TG) is an enzymatically crosslinkable adhesive hydrogel with chondrogenic properties demonstrated in vitro and in an ectopic mouse model. In this study, we investigated the feasibility of using HA-TG in a collagen scaffold to treat chondral lesions in an ovine model, to evaluate cartilage regeneration in a mechanically and biologically challenging joint environment, and the influence of the surgical procedure on the repair process. Design Chondral defects of 6-mm diameter were created in the stifle joint of skeletally mature sheep. In a 3-month study, 6 defects were treated with HA-TG in a collagen scaffold to test the stability and biocompatibility of the defect filling. In a 6-month study, 6 sheep had 12 defects treated with HA-TG and collagen and 2 sheep had 4 untreated defects. Histologically observed quality of repair tissue and adjacent cartilage was semiquantitatively assessed. Results HA-TG adhered to the native tissue and did not cause any detectable negative reaction in the surrounding tissue. HA-TG in a collagen scaffold supported infiltration and chondrogenic differentiation of mesenchymal cells, which migrated from the subchondral bone through the calcified cartilage layer. Additionally, HA-TG and collagen treatment led to better adjacent cartilage preservation compared with empty defects ( P < 0.05). Conclusions This study demonstrates that the adhesive HA-TG hydrogel in a collagen scaffold shows good biocompatibility, supports in situ cartilage regeneration and preserves the surrounding cartilage. This proof-of-concept study shows the potential of this approach, which should be further considered in the treatment of cartilage lesions using a single-step procedure.

scholarly journals Structure Inheritance in Nanoparticle Ink Direct-Writing Processes and Crack-Free Nano-Copper Interconnects Printed by a Single-Run Approach

Materials ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1559 ◽  
Author(s):  
Shujie Liu ◽  
Yujie Li ◽  
Songling Xing ◽  
Lei Liu ◽  
Guisheng Zou ◽  
...  
Keyword(s):  
Copper Interconnects ◽  
Optimum Process ◽  
Direct Writing ◽  
Sintering Process ◽  
Mechanical Agitation ◽  
Process Route ◽  
Weak Gel ◽  
Printing Processes ◽  
Nanoparticle Ink ◽  
Gel Network

When nanoparticle conductive ink is used for printing interconnects, cracks and pores are common defects that deteriorate the electrical conductivity of the printed circuits. Influences of the ink solvent, the solid fraction of the ink, the pre-printing treatment and the sintering parameters on the interconnect morphology and conductivity were investigated. It was found that the impacts of all these factors coupled with each other throughout the whole procedure, from the pre-printing to the post-printing processes, and led to a structure inheritance effect. An optimum process route was developed for producing crack-free interconnects by a single-run direct-writing approach using home-made nano-copper ink. A weak gel was promoted in the ink before printing in the presence of long-chain polymers and bridging molecules by mechanical agitation. The fully developed gel network prevented the phase separation during ink extrusion and crack formations during drying. With the reducing agents in the ink and slow evaporation of the ink solvent, compact packing and neck joining of copper nanoparticles were obtained after a two-step sintering process. The crack-free interconnects successfully produced have a surface roughness smaller than 1.5 μm and the square resistances as low as 0.01 Ω/□.

Planar integration of flexible micro-supercapacitors with ultrafast charge and discharge based on interdigital nanoporous gold electrodes on a chip

2016 ◽  
Vol 4 (24) ◽  
pp. 9502-9510 ◽  
Author(s):  
Chao Zhang ◽  
Jian Xiao ◽  
Lihua Qian ◽  
Songliu Yuan ◽  
Shuai Wang ◽  
...  
Keyword(s):  
Electrochemical Performance ◽  
Nanoporous Gold ◽  
Gold Electrodes ◽  
Direct Writing ◽  
Excellent Electrochemical Performance ◽  
Writing Technology

A flexible micro-supercapacitor based on interdigital nanoporous gold electrodes is elaborately designed through direct writing technology, exhibiting excellent electrochemical performance.

Direct measurement of electron-diffraction-pattern intensities using an energy loss spectrometer

1989 ◽  
Vol 47 ◽  
pp. 668-669
Author(s):  
A. G. Jackson ◽  
M. Rowe
Keyword(s):  
Thermal Effects ◽  
Dynamic Range ◽  
Scattering Amplitude ◽  
Dynamical Theory ◽  
Site Symmetry ◽  
Proof Of Concept ◽  
Parallel Acquisition ◽  
Kinematic Approximation ◽  
Speed Up ◽  
Structure Calculations

Diffraction intensities from intermetallic compounds are, in the kinematic approximation, proportional to the scattering amplitude from the element doing the scattering. More detailed calculations have shown that site symmetry and occupation by various atom species also affects the intensity in a diffracted beam. [1] Hence, by measuring the intensities of beams, or their ratios, the occupancy can be estimated. Measurement of the intensity values also allows structure calculations to be made to determine the spatial distribution of the potentials doing the scattering. Thermal effects are also present as a background contribution. Inelastic effects such as loss or absorption/excitation complicate the intensity behavior, and dynamical theory is required to estimate the intensity value.The dynamic range of currents in diffracted beams can be 104or 105:1. Hence, detection of such information requires a means for collecting the intensity over a signal-to-noise range beyond that obtainable with a single film plate, which has a S/N of about 103:1. Although such a collection system is not available currently, a simple system consisting of instrumentation on an existing STEM can be used as a proof of concept which has a S/N of about 255:1, limited by the 8 bit pixel attributes used in the electronics. Use of 24 bit pixel attributes would easily allowthe desired noise range to be attained in the processing instrumentation. The S/N of the scintillator used by the photoelectron sensor is about 106 to 1, well beyond the S/N goal. The trade-off that must be made is the time for acquiring the signal, since the pattern can be obtained in seconds using film plates, compared to 10 to 20 minutes for a pattern to be acquired using the digital scan. Parallel acquisition would, of course, speed up this process immensely.

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