Synthesis of zinc porphyrins and effect of peripheral substituents on the coordination reaction

Three free-base porphyrins, modified with Boc-d-threonine and their zinc porphyrins have been synthesized using benzaldehyde, 4-chlorobenzaldehyde, and 4-methoxybenzaldehyde. The effects of peripheral substituents on the coordination reactions between zinc porphyrins and imidazole derivatives have been studied by UV-visible spectroscopy, fluorescence spectrometry, and theoretical calculations. The results show that the coordination reaction forms a Zn-N bond between zinc porphyrins involving different peripheral substituents and imidazole derivatives. The association coordination constants decrease (N-MeIm > Im) due to the change in enthalpy; the zinc porphyrin synthesized using 4-chlorobenzaldehyde and N-methylimidazole shows the largest association constant. Fluorescent quenching is observed during the coordination process with the zinc porphyrin synthesized using 4-methoxybenzaldehyde and N-methylimidazole showing the largest Stern-Volmer quenching rate constant. In addition, theoretical calculations have been used to investigate essential characteristics of the reaction, charges, bond lengths, and bond energies for each system

ATP-Responsive and Near-Infrared-Emissive Nanocarriers for Anticancer Drug Delivery and Real-Time Imaging

Stimuli-responsive and imaging-guided drug delivery systems hold vast promise for enhancement of therapeutic efficacy. Here we report an adenosine-5'-triphosphate (ATP)-responsive and near-infrared (NIR)-emissive conjugated polymer-based nanocarrier for the controlled release of anticancer drugs and real-time imaging. We demonstrate that the conjugated polymeric nanocarriers functionalized with phenylboronic acid tags on surface as binding sites for ATP could be converted to the water-soluble conjugated polyelectrolytes in an ATP-rich environment, which promotes the disassembly of the drug carrier and subsequent release of the cargo. In vivo studies validate that this formulation exhibits promising capability for inhibition of tumor growth. We also evaluate the metabolism process by monitoring the fluorescence signal of the conjugated polymer through the in vivo NIR imaging

Thrombin-Responsive Transcutaneous Patch for Auto-Anticoagulant Regulation

A thrombin-responsive closed-loop patch is developed for prolonged heparin delivery in a feedback-controlled manner. This microneedle-based patch can sense activated thrombin and subsequently releases heparin to prevent coagulation in the blood flow. This "smart" heparin patch can be transcutaneously inserted into skin without drug leakage and can sustainably regulate blood coagulation in response to thrombin

Density Functional Theory Analysis of the Copolymerization of Cyclopropenone with Ethylene Using a Palladium Catalyst

Density functional theory has been used to elucidate the mechanism of Pd copolymerization of cyclopropenone with ethylene. The results reveal that introducing ethylene and cyclopropenone to Pd catalyst is thermodynamically feasible and generates the α,β-unsaturated ketone unit (UnitA). Cis-mode insertion and Path A1a are the most favorable reaction routes for ethylene and cyclopropenone, respectively. Moreover, cyclopropenone decomposition can generate CO in situ without a catalyst or with a Pd catalyst. The Pd-catalyzed decomposition of cyclopropenone exhibits a lower reaction barrier (22.7 kcal/mol) than its direct decomposition. Our study demonstrates that incorporating CO into the Pd catalyst can generate the isolated ketone unit (UnitB). CO is formed first; thereafter, UnitB is generated. Therefore, the total energy barrier of UnitB generation, accounting for the CO barrier, is 22.7 kcal/mol, which is slightly lower than that of UnitA generation (24.0 kcal/mol). Additionally, the possibility of copolymerizing ethylene, cyclopropenone, and allyl acetate (AAc) has been investigated. The free energy and global reactivity index analyses indicate that the cyclopropenone introduction reaction is more favorable than the AAc insertion, which is consistent with the experimental results. Investigating the copolymerization mechanism will help to develop of a functionalization strategy for polyethylene polymers

The Kth-best approach for linear bilevel multifollower programming with partial shared variables among followers

In a real world bilevel decision-making, the lower level of a bilevel decision usually involves multiple decision units. This paper proposes the Kth-best approach for linear bilevel multifollower programming problems with sharing variables among followers. Finally a numeric example is given to show how the Kth-best approach works

A Web-based Decision Support System for Linear Bilevel Problems

Abstract Advanced web and database technology support remote data access and communication. It has opened new opportunities for decision support system builders to d~velop web-based DSS. This paper presents a web-based decision support system for linear bileveI~oblems. An extended Kuhn-Tucker method for linear bilevel programming is implemented in this system. It can compute a global optimal solution for linear bilevel programming problems

An extended branch and bound algorithm for linear bilevel programming

[Abstract]: For linear Bilevel programming, the branch and bound algorithm is the most successful algorithm to deal with the complementary constraints arising from Kuhn-Tucker conditions. However, one principle challenge is that it could not well handle a linear bilevel programming problem when the constraint functions at the upper-level are of arbitrary linear form. This paper proposes an extended branch and bound algorithm to solve this problem. The results have demonstrated that the extended branch and bound algorithm can solve a wider class of linear bilevel problems can than current capabilities permit

An extended Kuhn-Tucker approach for linear bilevel multifollower programming with partial shared variables among followers

In a real world bilevel decision-making, the lower level of a bilevel decision usually involves multiple decision units. This paper proposes an extended Kuhn-Tucker approach for linear bilevel multifollower programming problems with partial shared variables among followers. Finally numeric examples are given to show how the Kuhn-Tucker approach works

AN EXTENDED BRANCH AND BOUND ALGORITHM FOR BILEVEL MULTI-FOLLOWER DECISION MAKING IN A REFERENTIAL-UNCOOPERATIVE SITUATION

Within the framework of any bilevel decision problem, a leader's decision at the upper level is influenced by the reaction of their follower at the lower level. When multiple followers are involved in a bilevel decision problem, the leader's decision will not only be affected by the reactions of those followers, but also by the relationships among those followers. One of the popular situations within this framework is where these followers are uncooperatively making decisions while having cross reference of decision information, called a referential-uncooperative situation in this paper. The well-known branch and bound algorithm has been successfully applied to a one-leader-and-one-follower linear bilevel decision problem. This paper extends this algorithm to deal with the above-mentioned linear bilevel multi-follower decision problem by means of a linear referential-uncooperative bilevel multi-follower decision model. It then proposes an extended branch and bound algorithm to solve this problem with a set of illustrative examples in a referential-uncooperative situation.Linear bilevel programming, branch and bound algorithm, optimization, multi-followers

Cryptoanalysis of the modified diffractive-imaging-based image encryption by deep learning attack

10.1080/09500340.2020.1862329Journal of Modern Optics67171398-140