Narrow Results

It is known that redox reaction can take place among the solutions of potassium ferrocyanide (K₄[Fe(CN)₆]), glucose (C₆H${}_{12}$O₆) and glucose oxidase (Glucose Oxidase, GOD). In this work, the method of electrochemical biosensor detection based on screen printed electrode was used to observe the redox reaction among these solutions. The relationship between redox reaction and parameters was studied by examining the effects of concentration and scanning speed of three solutions.

Current model for circadian rhythms is wrong both theoretically and practically. A new model, called yin yang model, is proposed to explain the mechanism of circadian rhythms. The yin yang model separate circadian activities in a circadian system into yin (night activities) and yang (day activities) and a circadian clock into a day clock and a night clock. The day clock is the product of night activities, but it promotes day activities; the night clock is the product of day activities, but it promotes night activities. The clock maintains redox or energy homeostasis of the internal environment and allows temporal separations between biological processes with opposite impacts on the internal environment of a circadian system.

The following topics are under this section:

• ASIA-PACIFIC — Shedding Light on COVID-19 Vaccine Development
• ASIA-PACIFIC — Community-led Interventions for Improving Blood Pressure Control
• ASIA-PACIFIC — Importance of Redox Homeostasis in Potential Treatment of Disease
• ASIA-PACIFIC — Novel Processor Architecture to Solve Complex Mathematical Problems
• ASIA-PACIFIC — Uncovering Mechanisms of the Human Biological Clock
• ASIA-PACIFIC — Discovery of Healthy Stomach Stem Cells Reveals Cancer Origins
• ASIA-PACIFIC — Cataloguing Cancer “fingerprints” to Map Cancer Genomes
• ASIA-PACIFIC — Creating a Circular Economy using Greenhouse Gases
• REST OF THE WORLD — Guide for Liquid Biopsy in Individual Glioblastoma Patients
• REST OF THE WORLD — Multi-purpose use of Breast and Kidney Cancer Drugs
• REST OF THE WORLD — The Two Faces of Immune Cells
• REST OF THE WORLD — Fine Particle Air Pollution Linked to Development of Kidney Disease

A series of fully β-pyrrole brominated triarylcorrole metal complexes has been prepared for investigating the changes in visible spectra and redox potentials relative to the non-brominated derivatives, as well as for comparing the effect of bromination in corroles and porphyrins. The results reveal that bromination has a much larger effect on the electrochemistry of metallocorroles relative to metalloporphyrins, for both macrocycle- and metal-centered redox processes. The HOMO–LUMO gap energy of the triarylcorrole post-transition metal complexes decreases upon bromination because the effect on the LUMO is about twice as large of as on the HOMO; and both the HOMO and the LUMO are more affected in corroles than in porphyrins. Spectroscopic examinations of the transition metal complexes reveal that the synthetic access to divalent metallocorroles becomes feasible for the brominated derivatives.

Mixing Cu(II)Cl₂ with free base tetraphenylporphyrin ((H₂(TPP)) in dry deaerated 1,2-dichloroethane surprisingly yields a mixture of Cu(II)(TPP) and Cu(III)(TPP). The later is long-lived in the absence of water and slowly decomposes within days to yield Cu(II)(TPP). Furthermore, in the presence of air, a slightly different Cu^III porphyrin species forms, presumably, Cu(III)(TPP)^•+, in which the Q-band is subject to a 10 nm red shift. The new Cu(III)(TPP) and Cu(III)(TPP)^•+ differ in terms of absorption, fluorescence, electron paramagnetic resonance (EPR), and X-ray photoemission spectroscopy (XPS) when compared to the well-characterized Cu(II)(TPP), Cu(II)(TPP)^•+, and Cu(II)(TPP)²⁺ species.

4-[4-(1-Methyl-1-penylethyl)phenoxy]- and 4,5-di-[4-(1-methyl-1-phenylethyl)phenoxy]phthalonitriles are obtained by nucleophilic substitution. Mono- and double-decker lutetium and erbium complexes of 2(3),9(10),16(17),23(24)-tetrakis- and 2,3,9,10,16,17,23,24-octakis-[4-(1-methyl-1-phenylethyl)phenoxy]phthalocyanines are synthesized based on the phthalonitriles. Synthesized complexes are studied spectrophotometrically.

This study presented the redox and magnetically responsive water-in-oil (W/O) Pickering emulsions stabilized by amphiphilic Fe₃O₄ nanoparticles. The magnetic nanoparticles synthesized by a conventional solvothermal method were further modified and characterized by Fourier-transform infrared (FT-IR), scanning electron microscopy (SEM) and energy-dispersive system (EDS). The results showed that Fe₃O₄ nanoparticles modified by 3-pyridyl-5-ferrocenyl-2-pyrazoline (PFP) showed strong interfacial activity, which could be used to emulsify toluene and water to prepare stable water-in-toluene emulsions. Moreover, due to the good redox properties of PFP, the emulsions could be switched between stable/unstable by adding trace amounts of oxidant and reducing agents alternately. At the same time, the emulsion droplets could be moved by applying magnetic field due to the superparamagnetic nature of Fe₃O₄ nanoparticles. Moreover, based on the electrostatic interaction, $\pi$–$\pi$ stacking and solubilization effect, the obtained Pickering emulsions could be used as an excellent extraction system for dye molecules Congo red with extraction efficiency up to 97%. In addition, the droplets of the emulsion could be reused by simple washing, which provided a new method for dye contaminant removal.

Photodynamic therapy (PDT) gains wide attention as a useful therapeutic method for cancer. It is mediated by the oxygen and photosensitizer under the specific light irradiation to produce the reactive oxygen species (ROS), which induce cellular toxicity and regulate the redox potential in tumor cells. Nowadays, genetic photosensitizers of low toxicity and easy production are required to be developed. KillerRed, a unique red fluorescent protein exhibiting excellent phototoxic properties, has the potential to act as a photosensitizer in the application of tumor PDT. Meantime, the course of tumor redox metabolism during this treatment was rarely investigated so far. Thus here, we investigated the effects of KillerRed-based PDT on tumor growth in vivo and examined the subsequent tumor metabolic states including the changes of nicotinamide adenine dinucleotide hydrogen (NADH) and flavoprotein (Fp), two important metabolic coenzymes of tumor cells. Results showed the tumor growth had been significantly inhibited by KillerRed-based PDT treatment compared to control groups. A home-made cryo-imaging redox scanner was used to measure intrinsic fluorescence and exogenous KillerRed fluorescence signals in tumors. The Fp signal was elevated by nearly 4.5-fold, while the NADH signal decreased by 66% after light irradiation, indicating that Fp and NADH were oxidized in the course of KillerRed-based PDT. Furthermore, we also observed correlation between the fluorescence distribution of KillerRed and NADH. It suggests that the KillerRed protein based PDT might provide a new approach for tumor therapy accompanied by altering tumor metabolism.

4-[4-(1-Methyl-1-penylethyl)phenoxy]- and 4,5-di-[4-(1-methyl-1-phenylethyl)phenoxy]phthalonitriles are obtained by nucleophilic substitution. Mono- and double-decker lutetium and erbium complexes of 2(3),9(10),16(17),23(24)-tetrakis- and 2,3,9,10,16,17,23,24-octakis-[4-(1-methyl-1-phenylethyl)phenoxy]phthalocyanines are synthesized based on the phthalonitriles. Synthesized complexes are studied spectrophotometrically.