Spectroscopic Characterization of 3-Aminoisoxazole,a Prebiotic Precursor of Ribonucleotides

The processes and reactions that led to the formation of the first biomolecules on Earth play a key role in the highly debated theme of the origin of life. Whether the first chemical building blocks were generated on Earth (endogenous synthesis) or brought from space (exogenous delivery) is still unanswered. The detection of complex organic molecules in the interstellar medium provides valuable support to the latter hypothesis. To gather more insight, here we provide the astronomers with accurate rotational frequencies to guide the interstellar search of 3-aminoisoxazole, which has been recently envisaged as a key reactive species in the scenario of the so-called RNA-world hypothesis. Relying on an accurate computational characterization, we were able to register and analyze the rotational spectrum of 3-aminoisoxazole in the 6–24 GHz and 80–320 GHz frequency ranges for the first time, exploiting a Fourier-transform microwave spectrometer and a frequency-modulated millimeter/sub-millimeter spectrometer, respectively. Due to the inversion motion of the −NH₂ group, two states arise, and both of them were characterized, with more than 1300 lines being assigned. Although the fit statistics were affected by an evident Coriolis interaction, we were able to produce accurate line catalogs for astronomical observations of 3-aminoisoxazole.     

对皮尔斯电子枪综合法的改进

 在低压缩比、低导流系数情况下,对Vaughan迭代综合法因阴极半锥角初始值取得不合理而失效的原因进行了分析,并对其中的迭代公式进行了合理修正。采用Vaughan迭代综合法和修正后的迭代综合法验算了13支不同性能的电子枪,结果表明：采用修正迭代法,阴极半锥角初始值即使在0°~70°取值,都能得出正确的计算结果。在原来Vaughan法适应的情况下,修正法与原方法的阴极半锥角结果之间差值小于1°;在原来Vaughan法失效的情况下(如低导流系数、低压缩比小于7),改进后的方法也能得到接近实测值的合理结果。     

Wastewater To Resource: Design of a Sustainable Phosphorus Recovery System

To enable a more sustainable wastewater treatment processes, a transition towards resource recovery methods that have minimal environmental impact while being financially viable is imperative. Phosphorus (P) is a finite resource that is being discharged into the aqueous environment in excessive quantities. As such, understanding the financial and environmental effectiveness of different approaches for removing and recovering P from wastewater streams is important to reduce the overall impact of wastewater treatment. In this study, a process-systems modelling framework for comprehensively evaluating these approaches in terms of both economic and environmental impacts is developed. Applying this framework, treatment pathways are designed, simulated and analysed to determine the most suitable approaches for P removal and recovery. The purpose of this methodology is not only to assist with plant design, but also to identify the principal economic and environmental factors acting as barriers to implementing a given technology, incorporating the impact of waste recovery. The results suggest that the chemical and ion-exchange approaches studied deliver sustainable advantages over biological pathways, both economically and environmentally, with each possessing different strengths. The assessment methodology developed enables a more rational and environmentally sound wastewater plant design approach to be taken.     

Coordination‐driven self‐assembly of Cp*Rh‐based rectangles in novel families of hetero‐bimetallic metal–organic frameworks

The crystal and molecular structures of a series of structurally related 1,2,3‐triazole‐4,5‐dicarboxylate (LHtzdc = 1,2,3‐triazole‐4,5‐dicarboxylate) ligands for second metal ions were established via single‐crystal X‐ray structural analysis. [Cu (en)]²⁺ (en = ethylenediamine) was selected as a second metal ion, the two spare sites of the O atom from LHtzdc are coordinated to a single [Cu (en)]²⁺, and the [Cu (en)]²⁺ metal centres act as two outer pockets, which is an effective and innovative method of controlling the assembly of heterometallic cages.     

Effects of microfiltration combined with ultrasonication on shelf life and bioactive protein of skim milk

To extend the shelf life and retain bioactive proteins in milk, this study utilized microfiltration (MF) combined with ultrasonication to treat skim milk and investigated its efficiency in removing bacteria and retaining bioactive proteins compared with HTST pasteurization and microfiltration alone. Results showed that microfiltration combined with ultrasonication at 1296 J/mL could completely remove the bacteria in skim milk. Ultrasonication further extended the shelf life (4 °C) of microfiltered skim milk, which could reach at least 40 days when MF was combined with ˃1296 J/mL ultrasonication. In addition, ELISA showed that HTST pasteurization significantly decreased the levels of IgG by ~30%, IgA by ~ 50%, IgM by ~60%, and lactoferrin by ~40%, whereas the activity of the enzymes lactoperoxidase and xanthine oxidase were also decreased by ~ 20%. Compared with HTST, MF alone or combined with ultrasonication retained these bioactive proteins to a larger degree. On the other hand, proteomics indicated both damage to casein micelle and fat globule structures in milk when ultrasonication at >1296 J/mL was applied, as shown by increases in caseins and milk fat globular proteins. Simultaneously, this ultrasound intensity also decreased levels of bioactive proteins, such as complement factors. Taken together, this study provided new insights that may help to implement this novel combination of non-thermal technologies for the dairy industry aimed at improving milk quality and functionality.     

Organoruthenium (II) complexes featuring pyrazole‐linked Schiff base ligands: Crystal structure,DNA/BSA interactions,cytotoxicity and molecular docking

Half‐sandwiched ruthenium (II) arene complexes with piano stool‐like geometry with the general formula [(p‐cymene)RuClL¹] and [(p‐cymene)RuClL²] [where L¹ = (Z)‐N′‐((1,3‐diphenyl‐1H‐pyrazol‐4‐yl)methylene)furan‐2‐carbohydrazide and L² = (Z)‐N′‐((1,3‐diphenyl‐1H‐pyrazol‐4‐yl)methylene)thiophene‐2‐carbohydrazide] were synthesized and characterized. The single crystal X‐ray data revealed that the complexes belong to the same crystal system (monoclinic) with octahedral geometry, where the ruthenium atom is surrounded by hydrazone ligand coordinated through ON atoms, one chloride labile co‐ligand and the remaining three coordination sites covered by an electron cloud of p‐cymene moiety. The interaction between the complexes and DNA/bovine serum albumin (BSA) was evaluated using absorption and emission titration methods showing intercalative modes of interaction. The DNA cleavage ability of the complexes was checked by agarose gel electrophoresis method exhibiting the destruction of DNA duplex arrangement. To understand the interaction between ruthenium complex and DNA/BSA molecule, molecular docking studies were performed. In vitro cytotoxicity of the complexes was examined by the 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide (MTT) assay on human lung cancer cell line, A549, and found that at lower IC₅₀, cell growth inhibition has occurred. Similarly, the IC₅₀ values of the complexes treated with cancerous cell lines have produced a significant amount of lactase dehydrogenase and nitrite content in the culture medium, which were evaluated as apoptosis‐inducing factors, suggesting that the ruthenium (II) arene hydrazone complexes with pyrazole ligands have promising anticancer activities.     

Oscillation result for half‐linear dynamic equations on timescales and its consequences

We study oscillatory properties of half‐linear dynamic equations on timescales. Via the combination of the Riccati technique and an averaging method, we find the domain of oscillation for many equations. The presented main result is not the conversion of a known result from the theory of differential or difference equations, ie, we obtain new results for the timescales (for differential equations) and (for difference equations). Half‐linear equations generalize linear equations (in fact, they coincide with certain one‐dimensional PDEs with p‐Laplacian), but the main result is new also for linear differential and difference equations. The corresponding corollaries and examples are given as well.     

Aromatic patterns: Tryptophan aromaticity as a catalyst for the emergence of life and rise of consciousness

Sunlight held the key to the origin of life on Earth. The earliest life forms, cyanobacteria, captured the sunlight to generate energy through photosynthesis. Life on Earth evolved in accordance with the circadian rhythms tied to sensitivity to sunlight patterns. A unique feature of cyanobacterial photosynthetic proteins and circadian rhythms' molecules, and later of nearly all photon-sensing molecules throughout evolution, is that the aromatic amino acid tryptophan (Trp) resides at the center of light-harvesting active sites. In this perspective, I review the literature and integrate evidence from different scientific fields to explore the role Trp plays in photon-sensing capabilities of living organisms through its resonance delocalization of π-electrons. The observations presented here are the product of apparently unrelated phenomena throughout evolution, but nevertheless share consistent patterns of photon-sensing by Trp-containing and Trp-derived molecules. I posit the unique capacity to transfer electrons during photosynthesis in the earliest life forms is conferred to Trp due to its aromaticity. I propose this ability evolved to assume more complex functions, serving as a host for mechanisms underlying mental aptitudes – a concept which provides a theoretical basis for defining the neural correlates of consciousness. The argument made here is that Trp aromaticity may have allowed for the inception of the mechanistic building blocks used to fabricate complexity in higher forms of life. More specifically, Trp aromatic non-locality may have acted as a catalyst for the emergence of consciousness by instigating long-range synchronization and stabilizing the large-scale coherence of neural networks, which mediate functional brain activity. The concepts proposed in this perspective provide a conceptual foundation that invites further interdisciplinary dialogue aimed at examining and defining the role of aromaticity (beyond Trp) in the emergence of life and consciousness.     

New Polyfluorinated Cyanine Dyes for Selective NIR Staining of Mitochondria

In this communication, the synthesis of three unknown polyfluorinated cyanine dyes and their application as selective markers for mitochondria are presented. By incorporating fluorous side chains into cyanine dyes, their remarkable photophysical properties were enhanced. To investigate their biological application, several different cell lines were incubated with the synthesized cyanine dyes. It was discovered that the presented dyes can be utilized for selective near-infrared-light (NIR) staining of mitochondria, with very low cytotoxicity determined by MTT assay. This is the first time that polyfluorinated cyanine fluorophores are presented as selective markers for mitochondria. Due to the versatile applications of polyfluorinated fluorophores in bioimaging and materials science, it is expected that the presented fluorophores will be stimulating for the scientific community.     

Stochastic utilities with subsistence and satiation: Optimal life insurance purchase,consumption and investment

We introduce stochastic utilities such that utility of any fixed amount of interest is a stochastic process or random variable. Also, there exist stochastic (or random) subsistence and satiation levels associated with stochastic utilities. Then, we consider optimal consumption, life insurance purchase and investment strategies to maximize the expected utility of consumption, bequest and pension with respect to stochastic utilities. We use the martingale approach to solve the optimization problem in two steps. First, we solve the optimization problem with an equality constraint which requires that the present value of consumption, bequest and pension is equal to the present value of initial wealth and income stream. Second, if the optimization problem is feasible, we obtain the explicit representations of the replicating life insurance purchase and portfolio strategies. As an application of our general results, we consider a family of stochastic utilities which have hyperbolic absolute risk aversion (HARA).