Blue and Green Light Responsive Caged Glutamate.

Glutamate (Glu) is an excitatory neurotransmitter that plays a critical role in memory. Brain mapping activities of such pathways relied heavily on the ability to release Glu with spatiotemporal precision. Several photo-protecting groups (PPGs), referred to as photocages or cages, were designed to accomplish the release of Glu upon irradiation. Previously reported Glu cages responded to UV upon irradiation with single photons, which limited their use in vivo experiments due to cytotoxicity. Other caged designs suffered from lower quantum efficiency (QE) of release necessitating higher concentrations and/or longer photoirradiation times. There have been limited examples of cages that respond to visible light with single photon irradiation. Herein, we report the efficient preparation of 11 caged Glu examples that respond to two visible wavelengths, 467 nm (thiocoumarin based) and 515-540 nm (BODIPY based). The kinetics of photouncaging were studied for all caged designs, and we report all quantum efficiencies, i.e., quantum yields (Φ), that ranged from 0.0001-0.65. Two of the BODIPY cages are reported here for the first time, and one, Me-BODIPY-Br-Glu, shows the most efficient Glu release with a QE of 0.65. Similar caged designs can be extended to the inhibitory neurotransmitter, GABA. This would enable the use of two visible wavelengths to modulate the release of excitatory and inhibitory neurotransmitters upon demand via optical control.

Significance of additive manufacturing amidst the pandemic.

In the light of COVID-19 pandemic, a global shortage for Personnel Protective Equipment (PPE) led to the search for an alternative to fill the gap where additive manufacturing made necessary development of rapid design and adaptive filtering masks for local manufacturing using 3D printing to help the frontline workers. The review focuses on the utilization of antimicrobial materials in additive manufacturing with the use of bespoke design to facilitate and respond to the disruptions in the medical supply chain. Previous studies confirmed the age-old theory of copper as an antimicrobial material with contact killing properties. The antimicrobial properties of copper have been registered at the U.S. Environmental Protection Agency as the first solid antimicrobial material. Combining the properties of copper in a PLA (Polylactic Acid) filament as a nano composite, Copper-3D facilitates the antimicrobial properties to any 3D printed object. Provided this flexibility of 3D printing, the use of masks designed distinctively based on the 3D scan of an individual's facial structures as an efficient Personnel Protective Equipment is also addressed. Additive manufacturing as a support to the shortage of medical devices and a responsive method to the disruption in the supply chain is discussed.

Synthesis and Characterization of Ligand-Stabilized Silver Nanoparticles and Comparative Antibacterial Activity against E. coli.

Silver is a well-established antimicrobial agent. Conjugation of organic ligands with silver nanoparticles has been shown to create antimicrobial nanoparticles with improved pharmacodynamic properties and reduced toxicity. Twelve novel organic ligand functionalized silver nanoparticles (AgNPs) were prepared via a light-controlled reaction with derivatives of benzothiazole, benzoxazine, quinazolinone, 2-butyne-1,4-diol, 3-butyne-1-ol, and heptane-1,7-dioic. UV-vis, Fourier-transform infrared (FTIR) spectroscopy, and energy-dispersive X-ray (EDAX) analysis were used to confirm the successful formation of ligand-functionalized nanoparticles. Dynamic light scattering (DLS) revealed mean nanoparticle diameters between 25 and 278 nm. Spherical and nanotube-like morphologies were observed using transmission electron microscopy (TEM) and scanning electron microscopy (SEM). Seven of the twelve nanoparticles exhibited strong antimicrobial activity and five of the twelve demonstrated significant antibacterial capabilities against E. coli in a zone-of-inhibition assay. The synthesis of functionalized silver nanoparticles such as the twelve presented is critical for the further development of silver-nanoconjugated antibacterial agents.

Retrofit of two way holding chuck to improve process efficiency and resource management.

In today's industrial scenarios, having continuous improvement to increase the process efficiency is one of the key measures. Especially manufacturing and automotive industries are putting forth a lot of resource and time to improve the efficiency of the process without compromising the current production capacity and improve the quality rate. This paper deals with a case study of retrofitting a two-way chuck in a vertical lathe machine and thereby calculating the overall equipment effectiveness of the entire automated process in piston manufacturing. The current automated production line of piston manufacturing is being analysed with the help of value stream mapping (VSM). Value stream mapping is widely used by the industrial persons to identify the wastes i.e., non-value-added time in the process line. The Critical to Quality (CTQ) parameters in an efficient production line such as lead time, value added time, transfer time and takt time have taken into account for identifying the places of improvement. A new retrofitted design has been suggested which can increase the production efficiency of the current system with effective utilization of available resources. After implementing the modified retrofit design, the subsequent changes in the process line have also been stated through Future state VSM, which clearly indicates the reduction in drop to drop time between the cells which has been considered as the non value added time in the current system. Studies like these shows that effective utilisation of available resources through retrofitting can greatly assist the manufacturers to reduce their cost of additional investment and be sustainable among the growing competitors in the market.