Chemical Analysis Research Articles

Introduction and Development of Surface-Enhanced Raman Scattering (SERS) Substrates: A Review.

Since its discovery, the phenomenon of Surface Enhanced Raman Scattering (SERS) has gradually become an important tool for analyzing the composition and structure of substances. As a trace technique that can efficiently and nondestructively detect single molecules, the application of SERS has expanded from environmental and materials science to biomedical fields. In the past decade or so, the explosive development of nanotechnology and nanomaterials has further boosted the research of SERS technology, as nanomaterial-based SERS substrates have shown good signal enhancement properties. So far, it is widely recognized that the morphology, size, composition, and stacking mode of nanomaterials have a very great influence on the strength of the substrate SERS effect. Herein, an overview of methods for the preparation of surface-enhanced Raman scattering (SERS) substrates is provided. Specifically, this review describes a variety of common SERS substrate preparation methods and explores the potential and promise of these methods for applications in chemical analysis and biomedical fields. By detailing the influence of different nanomaterials (e.g., metallic nanoparticles, nanowires, and nanostars) and their structural features on the SERS effect, this article aims to provide a comprehensive understanding of SERS substrate preparation techniques.

Fracture failure of oil-collecting steel wire reinforced thermoplastic composite pipe

A steel wire-reinforced thermoplastic composite pipe (SRTP) used as an oil connecting experienced fracture failure after 1.8 years’ service. In this paper, we conducted through on-site working condition investigation, visual physical inspection, analysis of the inner lining structure composition, physical and chemical properties analysis, thermal analysis, and mechanical analysis, and morphology analysis. The lining material of the SRTP exhibited significant swelling, which reduced its performance, and operation at high temperatures (>75°C) accelerated this process. Due to the swelling of oil and the permeation of CO2 and H2S, the oil and acid gases penetrated the interlayer of the composite pipe and accumulated in the annular space, continuously corroding and weakening the steel wire. This process gradually reduced its load-bearing capacity and pressure resistance. It is recommended that non-metallic pipes should be selected according to the service conditions to ensure that the materials are consistent with the design requirements.

On the issue of functional use of pics during the Early Neolithic: a case study from the LBK site in Wólka Wojnowska (S Poland)

Picks are extremely rare artefacts associated with flint inventories of the Linear Band Pottery culture (hereinafter: LBK). Previously, only three such artefacts attributed to this culture have been found in the drainage basins of the Vistula and Oder Rivers. The contexts of discovery of picks dated to slightly later times indicated that they should be linked with mining activities of early agricultural societies. The presented collection from Wólka Wojnowska is one of the most numerous typological series of LBK picks found at a single site within the entire range of the LBK. The results of traceological and chemical SEM-EDX analyses of residues preserved on their surfaces indicate that these tools were used in processing hematite in order to produce ochre. The obtained data considerably broaden the scope of the functions of picks used during the Early Neolithic and allow us to question the interpretation that they were only employed in mining for siliceous materials.

Intracellular Redox Environment Determines Cancer-normal Cell Selectivity of Selenium Nanoclusters.

Elucidating the chemical structure and intracellular action mechanisms is still the critical limit for the clinical translation of nanomedicines. Intracellular redox environments originating from cell metabolism are key factors affecting internalized drug efficacy. Herein, we engineer Se-Se/Se-S bond to assemble selenium nanoclusters with intracellular redox environment-driven selective structure. Chemical structure analysis reveals that, the bonding of sulfur atom in intermediates to the two neighboring or interposition selenium atoms in selenium rings is the key internal driving force for nanoparticle cluster formation. This nanocluster can be predominantly transformed to selenocysteine to facilitate selenoproteins synthesis in normal cells, while metabolize to cytotoxic SeO32- based on the oxidative intracellular redox environment of cancer cells. Resultantly, selenium nanoclusters exhibit significant cell proliferation inhibition ability to cancer cells and impressive safety to normal cells. Taken together, this study not only clarifies the chemical nature of the atom engineering of selenium nanocluster, but also elucidates its intracellular redox environment-oriented anticancer mechanism.

Intracellular Redox Environment Determines Cancer‐normal Cell Selectivity of Selenium Nanoclusters

Elucidating the chemical structure and intracellular action mechanisms is still the critical limit for the clinical translation of nanomedicines. Intracellular redox environments originating from cell metabolism are key factors affecting internalized drug efficacy. Herein, we engineer Se‐Se/Se‐S bond to assemble selenium nanoclusters with intracellular redox environment‐driven selective structure. Chemical structure analysis reveals that, the bonding of sulfur atom in intermediates to the two neighboring or interposition selenium atoms in selenium rings is the key internal driving force for nanoparticle cluster formation. This nanocluster can be predominantly transformed to selenocysteine to facilitate selenoproteins synthesis in normal cells, while metabolize to cytotoxic SeO32‐ based on the oxidative intracellular redox environment of cancer cells. Resultantly, selenium nanoclusters exhibit significant cell proliferation inhibition ability to cancer cells and impressive safety to normal cells. Taken together, this study not only clarifies the chemical nature of the atom engineering of selenium nanocluster, but also elucidates its intracellular redox environment‐oriented anticancer mechanism.

Development and Validation of a New Eco-Friendly HPLC-PDA Bioanalytical Method for Studying Pharmacokinetics of Seliciclib

Background and Objectives: Seliciclib (SEL) is the first selective, orally bioavailable potential drug containing cyclin-dependent kinase inhibitors. Preclinical studies showed antitumor activity in a broad range of human tumor xenografts, neurodegenerative diseases, renal dysfunctions, viral infections, and chronic inflammatory disorders. To support the pharmacokinetics and aid in therapeutic monitoring of SEL following its administration for therapy, an efficient analytical tool capable of quantifying the concentrations of SEL in blood plasma is needed. In the literature, there is no existing method for quantifying SEL in plasma samples. This study introduces the first HPLC method with a photodiode array (PDA) detector for the quantitation of SEL in plasma. Materials and Methods: The chromatographic resolution of SEL and linifanib as an internal standard (IS) was achieved on Zorbax Eclipse Plus C18 HPLC column (150 mm length × 4.6 mm internal diameter, 5 µm particle size), with a mobile phase composed of acetonitrile–ammonium acetate, pH 5 (50:50, v/v) at a flow rate of 1.0 mL min−1. Both SEL and IS were detected by PDA at 230 nm. The method was validated according to the ICH guidelines for bioanalytical method validation. Results: The method exhibited linearity in concentrations ranging from 50 to 1000 ng mL−1, with a limit of quantitation of 66.1 ng mL−1. All remaining validation parameters satisfied the ICH validation criteria. The environmental sustainability of the method was verified using three extensive tools. The proposed HPLC-PDA method was effectively utilized to study the pharmacokinetics of SEL in rats after a single oral administration of 25 mg/kg. Conclusions: The proposed method stands as a valuable tool for studying SELs for pharmacokinetics in humans. It aids in achieving the targeted therapeutic advantages and safety of treatment with SEL by optimizing the SEL dosage and dosing schedule.

Combining Differential Equations with Stochastic for Economic Growth Models in Indonesia: A Comprehensive Literature Review

Economic growth modeling is one of the methods a government can use to formulate appropriate economic policies to improve the prosperity of its people. Differential equations and stochastic models play a major role in studying economic growth. This article aims to conduct a literature review on the use of differential equations in relation to stochastics to model economic growth. In addition, this article also discusses the use of differential and stochastic equations in economic growth models in Indonesia. This study involves searching for and selecting articles to obtain a collection of research works relevant to the application of differential and stochastic equations to economic growth models, supported by bibliometric analysis. The results of this literature review show that there is still little research discussing economic growth models using differential equations combined with stochastic models, especially those applied in Indonesia. While the application of these models remains relatively limited, their potential to offer deeper insights into the complex dynamics of economic growth is undeniable. By further developing and refining these models, we can gain a more comprehensive understanding of the factors driving growth and the potential implications of various economic policies. This will ultimately equip policy-makers with a more powerful analytical tool for making informed decisions.

Impact of Surface Enhanced Raman Spectroscopy in Catalysis.

Catalysis stands as an indispensable cornerstone of modern society, underpinning the production of over 80% of manufactured goods and driving over 90% of industrial chemical processes. As the demand for more efficient and sustainable processes grows, better catalysts are needed. Understanding the working principles of catalysts is key, and over the last 50 years, surface-enhanced Raman Spectroscopy (SERS) has become essential. Discovered in 1974, SERS has evolved into a mature and powerful analytical tool, transforming the way in which we detect molecules across disciplines. In catalysis, SERS has enabled insights into dynamic surface phenomena, facilitating the monitoring of the catalyst structure, adsorbate interactions, and reaction kinetics at very high spatial and temporal resolutions. This review explores the achievements as well as the future potential of SERS in the field of catalysis and energy conversion, thereby highlighting its role in advancing these critical areas of research.

The Canadian VirusSeq Data Portal and Duotang: open resources for SARS-CoV-2 viral sequences and genomic epidemiology.

The COVID-19 pandemic led to a large global effort to sequence SARS-CoV-2 genomes from patient samples to track viral evolution and inform the public health response. Millions of SARS-CoV-2 genome sequences have been deposited in global public repositories. The Canadian COVID-19 Genomics Network (CanCOGeN - VirusSeq), a consortium tasked with coordinating expanded sequencing of SARS-CoV-2 genomes across Canada early in the pandemic, created the Canadian VirusSeq Data Portal, with associated data pipelines and procedures, to support these efforts. The goal of VirusSeq was to allow open access to Canadian SARS-CoV-2 genomic sequences and enhanced, standardized contextual data that were unavailable in other repositories and that meet FAIR standards (Findable, Accessible, Interoperable and Reusable). In addition, the portal data submission pipeline contains data quality checking procedures and appropriate acknowledgement of data generators that encourages collaboration. From inception to execution, the portal was developed with a conscientious focus on strong data governance principles and practices. Extensive efforts ensured a commitment to Canadian privacy laws, data security standards, and organizational processes. This portal has been coupled with other resources, such as Viral AI, and was further leveraged by the Coronavirus Variants Rapid Response Network (CoVaRR-Net) to produce a suite of continually updated analytical tools and notebooks. Here we highlight this portal (https://virusseq-dataportal.ca/), including its contextual data not available elsewhere, and the Duotang (https://covarr-net.github.io/duotang/duotang.html), a web platform that presents key genomic epidemiology and modelling analyses on circulating and emerging SARS-CoV-2 variants in Canada. Duotang presents dynamic changes in variant composition of SARS-CoV-2 in Canada and by province, estimates variant growth, and displays complementary interactive visualizations, with a text overview of the current situation. The VirusSeq Data Portal and Duotang resources, alongside additional analyses and resources computed from the portal (COVID-MVP, CoVizu), are all open source and freely available. Together, they provide an updated picture of SARS-CoV-2 evolution to spur scientific discussions, inform public discourse, and support communication with and within public health authorities. They also serve as a framework for other jurisdictions interested in open, collaborative sequence data sharing and analyses.

Enhanced Biological Potential and Phytochemical Profiling of Phoenix Dactylifera Leaves (Deglet Nour and Alig) by Kombucha Fermentation: Focus on Polyphenols, Antioxidant, Antidiabetic, and Cytotoxic Activities.

The date palm, scientifically known as Phoenix dactylifera, is an important cultural and economic source of wealth in southern Tunisia. It produces considerable agricultural waste, including palm leaves, the disposal of which is often a challenge. Our study addresses the sustainable conversion of date palm leaves into a valuable product through kombucha fermentation, focusing on two widely used varieties in Tunisia: Deglet Nour and Alig. HPLC-RI analysis showed a significant difference in the fermentation process between the treated samples, which is reflected in the highest sugar consumption and metabolite production in Alig palm. Unfermented and fermented date palm leaves were sequentially extracted with solvents of increasing polarity to evaluate their chemical composition and bioactivity. The results showed that kombucha fermentation significantly increased the total phenolic content, with the highest amounts in the ethyl acetate fraction. In terms of antioxidant activity, the ethyl acetate extracts showed a high percentage inhibitory activity (82.76%) against the DPPH radical found in fermented Palm Alig, which also exhibited the most important antidiabetic capacity (resulting in an IC50 value of 20 µg/mL). The chemical analyses resulted in the detection of 19 compounds by HPLC-DAD and 50 volatiles by GC-MS, which are mainly found in kombucha extracts.

MSBERT: Embedding Tandem Mass Spectra into Chemically Rational Space by Mask Learning and Contrastive Learning.

Tandem mass spectrometry (MS/MS) is a powerful technique for chemical analysis in many areas of science. The vast MS/MS spectral data generated in liquid chromatography-mass spectrometry (LC-MS) experiments require efficient analysis and interpretation methods for the following compound identification. In this study, we propose MSBERT based on self-supervised learning strategies to embed MS/MS spectra into reasonable embeddings for efficient compound identification. It adopts the transformer encoder as the backbone for mask learning and uses the same spectra with different masks for contrastive learning. MSBERT is trained on the GNPS data set and tested on the GNPS data set, the MoNA data set, and the MTBLS1572 data set. It exhibits enhanced library matching and analogous compound searching capabilities compared to existing methods. The recalls at 1, 5, and 10 on a GNPS test subset with structures not in the training set are 0.7871, 0.8950, and 0.9080, respectively. The results are better than those of Spec2Vec with 0.6898, 0.8276, and 0.8620, and DreaMS with 0.7158, 0.8327, and 0.8635. The rationality of embeddings is demonstrated by t-SNE visualization, structural similarity, spectra clustering, compound identification, and analogous compound searching. A user-friendly web server is provided for efficient spectral analysis, and the source code for MSBERT is available at https://github.com/zhanghailiangcsu/MSBERT.

Tracing the Past: Microwear Analysis of Stone and Shell Beads Unearthed in Early Neolithic Burials at Samborzec, Poland

This paper presents a thorough analysis of ornaments discovered in two Neolithic burials at Samborzec Site 1, providing valuable insights into their origins and significance. The artefacts, retrieved over six decades ago in the burials of a woman and child, have undergone extensive examination, including raw material identification, microwear studies, and the analysis of red residues found on their surfaces. While most of the ornaments concerned were crafted from marble, two beads were identified as Spondylus shells. Chemical analysis of residues, primarily found on the marble ornaments, revealed the presence of cinnabar, a red pigment of foreign origin. The remarkable similarities in ornaments between the investigated burials strongly suggest the association of both with LBK communities. The presented studies offer valuable insights into their object biographies, from the acquisition of raw materials from distant regions through their manufacture, assembly, and prolonged use as personal items. In this context, our research emphasizes their belonging to a shared Neolithic tradition in Europe.

Nutritional composition analysis in food images: an innovative Swin Transformer approach.

Accurate recognition of nutritional components in food is crucial for dietary management and health monitoring. Current methods often rely on traditional chemical analysis techniques, which are time-consuming, require destructive sampling, and are not suitable for large-scale or real-time applications. Therefore, there is a pressing need for efficient, non-destructive, and accurate methods to identify and quantify nutrients in food. In this study, we propose a novel deep learning model that integrates EfficientNet, Swin Transformer, and Feature Pyramid Network (FPN) to enhance the accuracy and efficiency of food nutrient recognition. Our model combines the strengths of EfficientNet for feature extraction, Swin Transformer for capturing long-range dependencies, and FPN for multi-scale feature fusion. Experimental results demonstrate that our model significantly outperforms existing methods. On the Nutrition5k dataset, it achieves a Top-1 accuracy of 79.50% and a Mean Absolute Percentage Error (MAPE) for calorie prediction of 14.72%. On the ChinaMartFood109 dataset, the model achieves a Top-1 accuracy of 80.25% and a calorie MAPE of 15.21%. These results highlight the model's robustness and adaptability across diverse food images, providing a reliable and efficient tool for rapid, non-destructive nutrient detection. This advancement supports better dietary management and enhances the understanding of food nutrition, potentially leading to more effective health monitoring applications.

Neither nectar nor deception: the role of floral rewards in the pollination system of Laelia (Orchidaceae: Laeliinae).

Orchids offer a variety of floral rewards to pollinators. In many orchid groups, however, the transfer of pollen is based on food-deception, as in the case of Laelia (including Schomburgkia s.s.), a genus assigned to the Neotropical subtribe Laeliinae. Here, we report on the reproductive biology of a Brazilian member of this subtribe, namely, Laelia gloriosa, occurring in the forested areas of southeastern Brazil. The study includes analyses of floral morphology, histochemistry, and the chemical analysis of floral rewards and scents. Pollinators and pollination mechanism data were collected in the field by means of focal observations. Analyses of breeding systems and the percentage of potentially viable seed were also recorded. The floral morphology of Laelia gloriosa indicates that this species is melittophilous. The flowers release a citrus-like fragrance that attracts many species of bee. The flowers offer waxy material as a reward, and this is collected exclusively by Meliponini bees. Several bee species visit the flowers. However, those of L. gloriosa are pollinated exclusively by Trigona spinipes. Pollinaria are deposited on the bee's scutellum. Plants of the studied population were entirely self-compatible, but pollinator-dependent. The frequency of visits to these flowers was greater than in rewardless Laeliinae. Our study provides the first evidence of lipoidal substances as a resource in Laeliinae. The discovery that an orchid species (Laelia gloriosa) of this subtribe, hitherto considered to be entirely pollinated by nectar-seeking pollinators, offers a floral waxy material and provides new insights into the evolution of this important subtribe.

Dinamika Transformasi Tasawuf Era Modern: Neo-Sufisme dan Gerakan Islam Transnasional

This article examines the dynamics transformation of Sufism in the modern era. Sufism in the modern era appears running into transformation both in terms of its concept and movement. From the aspect of the concept of Sufism, modern Sufism is running into a transformation, namely neo-Sufism. Likewise, in the network aspect of the Sufism movement in the modern era, Sufism moves dynamically, from a local movement to becoming a network of transnational Islamic movements. This research is qualitative research using transnationalism theory as an analytical tool and historical studies as an approach. In this research, at least two findings were found. First, the presence of neo-Sufism is a form of transformation of classical Sufism teachings. The concept of neo-Sufism tends to be balanced (tawazun) between exoteric and esoteric aspects and can be a spiritual alternative for urban Muslim communities. Second, modern Sufism can be categorized as a representation of a transnational Islamic movement, as a non-governmental movement structured across countries in terms of thought, spiritual and political movements. The main route behind the transnational Islamic movement of Sufism is through da'wah, trade and immigrants. Keywords: Sufism, Neo-Sufism, Transnationalism, Transformative

Recent Advances in Luminophores for Enhanced Electrochemiluminescence Analysis.

Electrochemiluminescence (ECL) detection is widely applied in many fields, including chemical measurement, biological analysis, and clinic tests, due to its high sensitivity. Currently, the fast development of many new electrochemical luminophores is continuously improving the ECL-based detection ability. Besides the enhancement of luminescence emission for a high detection sensitivity, minimizing the effect of co-reactants on ECL detection and achieving multiple analysis in one sample are also the main directions in this field. This review focuses on a summary of recently prepared new luminophores to achieve the three aims mentioned above. Especially, the review is composed by three parts, focusing on the luminophores or materials with high ECL efficiency, self-enhancing properties, and multi-color ECL luminophores. The fabrication of biosensors using these molecules is also reviewed to exhibit the advances in biological applications.

Experimental investigation of dodecanoic acid–tetradecanoic acid–dodecanol ternary mixture based nanoparticle enriched-phase change material for food preservation applications

In this research, a novel phase change material (PCM), containing dodecanoic acid-tetradecanoic acid-dodecanol ternary mixture, designated as pure mixture, dispersed with two carbon-based nanoparticles, i.e., graphene nanoplatelets - multiwall carbon nanotube and graphene nanoplatelets-titanium dioxide, with 1% weight fraction, is prepared and is designated as nanoparticle-enriched-phase change material. The chemical and thermal analysis of pure ternary mixture and nanoparticle-enriched-phase change material was conducted using X-ray diffraction, Scanning electron microscopy, Differential scanning calorimetry, Fourier transform infrared, Thermo gravimetric analyser and Thermal conductivity analyser techniques. The pure mixture possess melting and freezing temperature of 15.6°C and 8.4°C with a melting-freezing latent heat (LH) of 131.5 J/g and 125.4 J/g, respectively. The thermal conductivity exhibited a significant increase of 187.6% in the case of pure mixture with graphene nanoplatelets- multiwall carbon nanotube and 41.7% for pure mixture with graphene nanoplatelets-titanium dioxide. Moreover, the PCM remained thermally stable in both cases, even with the incorporation of nanoparticles. The melting as well as freezing LHs were reduced by about 18.17% and 18.02% for graphene nanoplatelets- multiwall carbon nanotube dispersed PCM and, 12.49% and 9.49% for graphene nanoplatelets- titanium dioxide dispersed PCM, respectively, in comparison with the pure mixture. Similarly, the melting/freezing temperatures, gets also reduced by 9.6%/8.3% and 10.9%/8.3%, respectively, for both mixtures. The pure mixture with graphene nanoplatelets- multiwall carbon nanotube exhibited a substantial decrease in both charging and discharging times, with reductions of 28.48% and 18.73%, respectively, in comparison to pure mixture, at an air inlet velocity of 3 m/s.

Calcium Imaging and Analysis in Beta Cells in Acute Mouse Pancreas Tissue Slices.

Ca2+ ions play a central role in the stimulus-secretion coupling cascade of pancreatic beta cells. The use of confocal microscopy in conjunction with the acute pancreas tissue slice technique offers valuable insights into changes in theintracellular calcium concentration following stimulation by secretagogues. This allows the study of beta cells on a single cell level, as well as their behavior on a multicellular scale within an intact environment. With the use of advanced analytical tools, this approach offers insight into how single cells contribute to the functional unit of islets of Langerhans and processes underlying insulin secretion. Here we describe a comprehensive protocol for the preparation and utilization of acute pancreas tissue slices in mice, the use of high-resolution confocal microscopy for observation of glucose-stimulated calcium dynamics in beta cells, and the computational analysis for objective evaluation of calcium signals.

Reference Material for the Composition of Fuel Oil

Electrical transformers are a key element in the process of distributing electricity from the producer to the final consumer. The reliability of electrical transformers is ensured through systematic monitoring of the structural condition using chemical analysis of fuel (transformer) oil used for electrical insulation and cooling of transformers. The working life of energy oil and paper insulation can be assessed by evaluating the content of antioxidant additive (ionol) and furan derivatives (furfuryl alcohol, furfural, 2-acetylfuran and 5-methylfurfural). The article provides a critical analysis of methods for measuring ionol and furan derivatives in oils. In particular, it has been established that the most widely used methods for the identification of ionol and furan derivatives are liquid and gas chromatography methods with preliminary isolation of analytes based on the principles of liquid/solid-phase extraction. At the same time, the need for matrix reference materials with established metrological traceability was identified for metrological support of methods for measuring the content of ionol and furan derivatives in oils. Therefore, the purpose of this study was the development of a certified reference material (CRM) for the composition of fuel oil. The technology for producing such a CRM makes it possible to prepare the material with the required concentrations of analytes. The article describes the sequence of preparation of a CRM batch and presents the conclusions of studying the stability and between-bottle homogeneity of the material. The given calculation of the standard uncertainty for the certified value of the CRM from the characterization method, heterogeneity, and instability of the material in accordance with GOST ISO Guide 35–2015 deserves attention. The metrological traceability of certified values of the CRM to the unit of value «mass fraction of a component» reproduced by the State Primary Standard of units of mass (molar) fraction and mass (molar) concentration of organic components in liquid and solid substances and materials based on liquid and gas chromatography-mass spectrometry with isotope dilution and gravimetry (GET 208–2019). The competence of the study is confirmed by the fact that the CRM was recognized as GSO 12232–2023.

Within Thermal Scales: The Kinetic and Energetic Pull of Chemical Entropy.

Biological systems are fundamentally containers of thermally fluctuating atoms that through unknown mechanisms are structurally layered across many thermal scales from atoms to amino acids to primary, secondary, and tertiary structures to functional proteins to functional macromolecular assemblies and up. Understanding how the irreversible kinetics (i.e., the arrow of time) of biological systems emerge from the equilibrium kinetics of constituent structures defined on smaller thermal scales is central to describing biological function. Muscle's irreversible power stroke - with its mechanochemistry defined on both the thermal scale of muscle and the thermal scale of myosin motors - provides a clear solution to this problem. Individual myosin motors function as reversible force-generating switches induced by actin binding and gated by the release of inorganic phosphate, P i . As shown in a companion article, when N individual switches thermally scale up to an ensemble of N switches in muscle, the entropy of a binary system of switches is created. We have shown in muscle that a change in state of this binary system of switches entropically drives actin-myosin binding (the switch) and muscle's irreversible power stroke, and that this simple two-state model accurately accounts for most key aspects of muscle contraction. Extending this observation beyond muscle, here I show that the chemical kinetics of an ensemble of N molecules differs fundamentally from a conventional chemical analysis of N individual molecules, describing irreversible chemical reactions as being pulled into the future by the a priori defined entropy of a binary system rather than being pushed forward by the physical occupancy of chemical states (e.g., mass action).