17 research outputs found
Probing Carbocatalytic Activity of Carbon Nanodots for the Synthesis of Biologically Active Dihydro/Spiro/Glyco Quinazolinones and Aza-Michael Adducts
Herein,
we report the fluorescent carbon dots as an effective and
recyclable carbocatalyst for the generation of carbonâheteroatom
bond leading to quinazolinone derivatives and aza-Michael adducts
under mild reaction conditions. The results establish this nanoscale
form of carbon as an alternative carbocatalyst for important acid
catalyzed organic transformations. The mild surface acidity of carbon
dots imparted by âCOOH functionality could effectively catalyze
the formation of synthetically challenging spiro/glycoquinazolinones
under the present reaction conditions
Carbon Dots as Nanodispersants for Multiwalled Carbon Nanotubes: Reduced Cytotoxicity and Metal Nanoparticle Functionalization
The colloidal stabilization
of multiwalled carbon nanotubes (MWCNTs)
in an aqueous medium through noncovalent interactions has potential
benefits toward the practical use of this one-dimensional carbonaceous
material for biomedical applications. Here, we report that fluorescent
carbon nanodots can efficiently function as dispersing agents in the
preparation of stable aqueous suspensions of CNTs at significant concentrations
(0.5 mg/mL). The amphiphilic nature of carbon dots with a hydrophobic
graphitic core could effectively interact with the CNT surface, whereas
hydrophilic oxygenated functionalization on the C-dot surface provided
excellent water dispersibility. The resultant CNT-C-dot composite
showed significantly reduced cytotoxicity compared to that of unmodified
or protein-coated CNTs, as demonstrated by cell viability and proliferation
assays. Furthermore, the reducing capability of C-dots could be envisaged
toward the formation of a catalytically active metal nanoparticle-CNT-C-dot
composite without the addition of any external reducing or stabilizing
agents that showed excellent catalytic activity toward the reduction
of <i>p</i>-nitrophenol in the presence of NaBH<sub>4</sub>. Overall, the present work establishes C-dots as an efficient stabilizer
for aqueous dispersions of CNTs, leading to an all-carbon nanocomposite
that can be useful for different practical applications
Monosomy X as the Sole Cytogenetic Abnormality in Acute Lymphoblastic Leukemia: A Report of Two New Patients
Integrated halide perovskite photoelectrochemical cells with solar driven water splitting efficiency of 20.8
Achieving high solar to hydrogen STH efficiency concomitant with long term durability using low cost, scalable photo absorbers is a long standing challenge. Here we report the design and fabrication of a conductive adhesive barrier CAB that translates gt;99 of photoelectric power to chemical reactions. The CAB enables halide perovskite based photoelectrochemical cells with two different architectures that exhibit record STH efficiencies. The first, a co planar photocathode photoanode architecture, achieved an STH efficiency of 13.4 and 16.3 amp; 8201;h to t60, solely limited by the hygroscopic hole transport layer in the n i p device. The second was formed using a monolithic stacked silicon perovskite tandem, with a peak STH efficiency of 20.8 and 102 amp; 8201;h of continuous operation before t60 under AM 1.5G illumination. These advances will lead to efficient, durable, and low cost solar driven water splitting technology with multifunctional barrier
Sharing aquatic genetic resources across jurisdictions: playing âchickenâ in the sea
International regimes regulating access and benefit sharing were originally designed to promote conservation and fairness objectives concerning the use of the worldâs biological resources for their genetic material value. These regimes determine from whom permission is required to take the resources and who obtains the benefits of their use. They have evolved separate frameworks in three distinct jurisdictional areasâwithin national jurisdiction, beyond national jurisdiction and in the Antarctic Treaty Area. This article argues that if these regimes continue to evolve separately, there is a strong temptation for countries to play âchickenâ with biological resource governance through forum shopping or opting out of agreements that do not suit their political ends. Using game theory and a transgenic tilapia fish example incorporating genetic material from the three jurisdictional areas, it illustrates the legal and ethical dilemmas that can arise from the territorial (jurisdictional) approach to access and benefit sharingâto the detriment of fairness and conservation in tilapiaâs countries of origin. Tilapias are known as the âchicken of the seaâ because they dominate global farmed production and developing countries depend on them as their primary source of protein, livelihoods and trade. This means there will be serious consequences if the regimes do not achieve their fairness and conservation objectives for sharing their genetic material. This article concludes that a purpose-driven cooperative governance approach can sidestep the game of chicken and promote fairer and more conservation focused outcomes than the current jurisdictional approach for the developing country providers of migratory aquatic resources