Substantia最新文献

{"title":"Capillary Electrophoresis and its Basic Principles in Historical Retrospect. Part 4. Svante Arrhenius´ Electrolyte Dissociation. From 56 Theses (1884) to Theory (1887)","authors":"E. Kenndler","doi":"10.36253/substantia-1679","DOIUrl":"https://doi.org/10.36253/substantia-1679","url":null,"abstract":"Since the main interest of Svante Arrhenius, a student at Uppsala University, was the electrical conductivity of highly dilute electrolyte solutions, which had not yet been determined at the beginning of the 1880s, he decided to determine experimentally the molecular conductivities of aqueous solutions of about fifty electrolytes and their dependence on the dilution. In his dissertation, which he began in the winter of 1882/1883, he summarized his results and considerations in 56 \"theses\". He observed that strong acids had a high molecular conductivity, which increased only slightly with increasing dilution. Weak acids, in contrast, had low molecular conductivities, but these increased abruptly above a certain dilution. Arrhenius' innovative hypothesis was that electrolyte molecules are composed from two parts, \"an active (electrolytic) and an inactive (non-electrolytic) part,\" with the proportion of the active part increasing with increasing dilution at the expense of the inactive part. Moreover, the electrically active part, which conducts electricity, was also the chemically active part. Arrhenius introduced the activity coefficient, later quoted as the degree of dissociation, which indicated the proportion of active molecules to the sum of active and inactive molecules. He tentatively related activity coefficient to molecular conductivity. He assumed that the higher the activity coefficients of different acids at the same equivalent concentrations, the stronger they are. Arrhenius tested his hypothesis taking the heat of neutralization of acids with a strong base measured by Thomsen and Berthelot. Strong acids developed the highest neutralization heats, i.e., the activation heat of water, since they consisted entirely of active H+ and OH- ions, which combined to inactive H2O. Weak acids developed correspondingly less. The established parallelism between the molecular conductivities of acids and their heats of neutralization was the first proof of Arrhenius' hypothesis. He relied on thermochemistry and completed his dissertation. He presented his dissertation in June 1883 and published it in 1884 to obtain his doctorate. At that time, Wilhelm Ostwald was investigating the affinities of acids to bases, i.e. the intensity of the effects of acids on the rates of reactions they cause. He took the rate constants as a measure of the relative strength of the acids. After receiving Arrhenius' thesis, he measured the acid´s molecular conductivities and found a remarkable proportionality to the reaction rate constants of the hydrolysis of methyl acetate and the inversion of cane sugar caused by them. This was the second proof of Arrhenius' hypothesis, based on the results of chemical kinetics. A memoir presented in 1885 by J. H. van 't Hoff on the analogy between the osmotic pressure of a highly dilute solution separated from the pure solvent by a semipermeable membrane and the pressure of an ideal gas containing the same number of particles as the solu","PeriodicalId":32750,"journal":{"name":"Substantia","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45026379","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Cultural Revolution: Ecological and Social","authors":"V. Balzani","doi":"10.36253/substantia-1741","DOIUrl":"https://doi.org/10.36253/substantia-1741","url":null,"abstract":"Our world is sick because of the bad relationship between human society and the planet and even more because of the discords within human society itself. We are slipping more and more towards ecological and social unsustainability. Both scientists and philosophers say it, and Pope Francis highlights these views in the Laudato Sì: \" Doomsday predictions can no longer be met with irony or disdain. [...] The pace of consumption, waste and environmental change has so stretched the planet’s capacity that our contemporary lifestyle, unsustainable as it is, can only precipitate catastrophes\". Here then, as the Pope writes, \" bold cultural revolution\" is needed.","PeriodicalId":32750,"journal":{"name":"Substantia","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42166776","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Light-Modulated Rheological Properties in Green Innovative Formulations","authors":"Duccio Tatini, M. Raudino, Filippo Sarri","doi":"10.36253/substantia-1736","DOIUrl":"https://doi.org/10.36253/substantia-1736","url":null,"abstract":"The addition of azorubine to a viscoelastic aqueous dispersion of sodium oleate (NaOL, 0.43 M, 13% w/w) and KCl (up to 4% w/w) leads to a green gel-like system whose rheological behavior can be efficiently and reversibly triggered from remote by using UV light. Rheology, Differential Scanning Calorimetry (DSC) measurements and phase behavior studies indicate that the original texture of the NaOL dispersion is significantly hardened upon UV irradiation for 8 hours in the presence of azorubine, showing a seven hundred-fold increase in viscosity. The UV treatment brings about the trans to cis isomerization of azorubine, which modifies the structure of the NaOL wormlike micellar system, leading to a more entangled, close-textured network. The cooperative effect of KCl on the fluid viscosity is found to be concentration-dependent. The system slowly reverts to its original rheological behaviour after standing for about 1 day. These results are relevant for the development of stimuli-responsive innovative systems based on biocompatible, non expensive and commercially available materials that can be used in a wide range of applications, such as in drug delivery or enhanced oil recovery, where a quick change in the physico-chemical features of the system is required but difficult to be performed.","PeriodicalId":32750,"journal":{"name":"Substantia","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46090942","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"True Story of Poly(2-Hydroxyethyl Methacrylate)-Based Contact Lenses: How Did It Really Happen","authors":"M. Dušková-Smrčková, J. Podešva, J. Michalek","doi":"10.36253/substantia-1591","DOIUrl":"https://doi.org/10.36253/substantia-1591","url":null,"abstract":"Soft hydrogel contact lenses represent the most famous and commercially successful application of poly(2‑hydroxyethyl methacrylate). The scarcely crosslinked network of this hydrophilic polymer finds its use also in many other fields, be it in (bio)medicine or technology. Moreover, the polymer itself and its crosslinked forms, discovered more or less serendipitously in the early fifties by a group of Czech chemists, is extremely interesting due to its exceptional properties: it readily swells in water, is optically clear, soft, biologically compatible, sufficiently strong, stable, gas-permeable, cheap, and easy to produce. Looking for its as-yet undiscovered qualities and possible utilization still continues. The story of the invention of hydrogel contact lenses was referred to many times in various literary sources which, however, contain numerous errors and misinterpretations. In the present article, we put these records straight and present the correct chronology of the hydrogel contact lenses development including the dramatic patent litigation. A brief overview of the chemical nature, properties, and applications of the constitutive substance of the lenses, i.e., the hydrophilic methacrylate, is also given.","PeriodicalId":32750,"journal":{"name":"Substantia","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48480324","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Just a Grand Duke who Loves Chemistry. Peter Leopold of Habsburg-Lorraine (1747–1792) and his Chemical Cabinet at the Imperial and Royal Museum of Physics and Natural History","authors":"G. Pratesi, A. Franza","doi":"10.36253/substantia-1600","DOIUrl":"https://doi.org/10.36253/substantia-1600","url":null,"abstract":"This article dealt with the history of the chemical cabinet established by the Grand Duke of Tuscany, Peter Leopold of Habsburg-Lorraine (1747–1792), at the Imperial and Royal Museum of Physics and Natural History in Firenze during his regency. To achieve this goal, it investigated untapped archival sources (e.g., administrative and commercial documents, minutes, correspondences, inventories) concerning the museum management from its foundation in 1775 to the departure of the Grand Duke for Vienna to be crowned as Holy Roman Emperor Leopold II in 1790. The article analyzed the chemical cabinet’s manuscript catalog, whose entire transcription is presented in the Supplementary Information Files. The work then examined the connections between the activities performed at the chemical laboratory and Peter Leopold’s interests in experimental chemistry. Concerning this research question, the scientific relationship he held with the naturalist Giovanni Valentino Mattia Fabbroni (1752–1822) – Vice-director and then Director of the Imperial and Royal Museum of Physics and Natural History – who helped the Grand Duke navigate all aspects of his interests in chemistry and natural sciences, was also discussed.","PeriodicalId":32750,"journal":{"name":"Substantia","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48072162","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Indigenous Sand Drawings as Predictors of the Cell Response to Nanoparticle Therapy","authors":"V. Uskoković","doi":"10.36253/substantia-1586","DOIUrl":"https://doi.org/10.36253/substantia-1586","url":null,"abstract":"A technique for predicting the response of cells and tissues to a physicochemical stimulus without the use of expensive molecular markers and at time points before any morphological changes can be visibly spotted would be a meaningful addendum to the current set of bioimaging tools. One such method was developed here based on correlating transformed distance matrices of populations of cultured cells and digital checkerboard patterns derived from traditional central African drawings in the sand. Similarity measurements were made at an early time point in the therapy administered to bone cancer cells in the form of composite magnetic nanoparticles. At this early of a time point, the cell viability was mildly reduced, but no gross alterations to the cell morphology or density were visible yet. Similarity score evaluation demonstrated a significantly higher degree of similarity between the patterns derived from the sand drawings and the cells subjected to the treatment than between the former patterns and the untreated cell controls. The treated cells produced more ordered and symmetric patterns than the control ones after the processing of their pairwise distant matrices, explaining their better geometric correlation with the ancestral sand arabesques, which were monolinear and commonly comprised multiple mirror planes and rotational symmetry axes. This has suggested that the course of the therapy could be predicted by a relatively simple comparison between raw optical images of cells and indigenous ideographs using the metrics postulated here. The interdisciplinary method developed in this study may prove applicable for in situ monitoring of the response of cells and tissues to various therapies, allowing for the early indications of adverse effects to be noticed based on the simple optical observations of cells and acted upon before the progression toward nonviable states becomes irreversible. The method elaborated here may also provide an impetus for a broader search for solutions to problems plaguing the modern medicine outside of the scope of its mainstream analytical frameworks and in the ancestral heritage of relatively obscure ethnic traditions.","PeriodicalId":32750,"journal":{"name":"Substantia","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46234680","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Chemists Without Knowing It?","authors":"H. Kragh","doi":"10.36253/substantia-1564","DOIUrl":"https://doi.org/10.36253/substantia-1564","url":null,"abstract":"This paper considers aspects of the chemistry-physics relationship from a historical perspective and with a focus on the entrance of quantum mechanics in twentieth-century chemistry. Traditionally, theoretical physics was widely regarded as epistemically superior to chemistry if also, from the chemists’ point of view, of little practical relevance. With the emergence of quantum chemistry in about 1930, the gulf widened as it seemed that the new discipline was more physics than chemistry. One way of investigating theoretically many-electron atoms was by means of the Hartree-Fock approximation method. The Møller-Plesset perturbation theory introduced in 1934 by a Danish and an American physicist was a refinement to the Hartree-Fock method. Although the Møller-Plesset theory was initially neglected – and is still neglected in the historiography of quantum chemistry – it came to play a most important role in later studies. Indeed, it is a prime example of what in sociological studies of science is known as a “sleeping beauty.” The paper discusses the historical context of the Møller-Plesset theory, concluding that, in a sense, its originators were “chemists without knowing it.”","PeriodicalId":32750,"journal":{"name":"Substantia","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48511372","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comments on Shirakawa’s Response","authors":"S. Rasmussen","doi":"10.36253/substantia-1529","DOIUrl":"https://doi.org/10.36253/substantia-1529","url":null,"abstract":"As both an active researcher in the synthesis of conjugated materials and a chemist-historian that has spent the last decade attempting to detail and clarify the history of conjugated and conducting polymers, I am overjoyed that Prof. Shirakawa has elected to provide additional personal details relating to the discovery and development of polyacetylene films. Shirakawa has provided this material in response to my most recent Substantia paper that details newly revealed accounts by Hyung Chick Pyun (1926-2018), who was a visiting Korean scientist that carried out the initial experiment that led to these films. This material is critical to advance our understanding of this important historical event.","PeriodicalId":32750,"journal":{"name":"Substantia","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44850510","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Is the Second Law of Thermodynamics Able to Classify Drugs?","authors":"L. Schwartz, Luc Benichou, Jules Schwartz, M. Pontie, Marc Henry","doi":"10.36253/substantia-1364","DOIUrl":"https://doi.org/10.36253/substantia-1364","url":null,"abstract":"Specialization characterizes pharmacology, with the consequence of classifying the various treatments into unrelated categories. Treating a specific disease usually requires the design of  a specific drug. The second law of thermodynamics is the driving force both for chemical reactions and for life. It applies to diseases and treatment. In most common diseases, there is a metabolic shift toward anabolism and anaerobic glycolysis, resulting in the release of entropy in the form of biomass. In accordance with the second principle of thermodynamics, treatment should aim at decreasing the entropy flux, which stays inside the body in the form of biomass. Most treatments aim at increasing the amount of entropy that is released by the cell in the form of thermal photons. As clinically different diseases often requires similar drugs, this calls for reinforcement in a quest for a single unified framework. For example, treatment of aggressive autoimmune diseases requires the same cytotoxic chemotherapy than for cancer. This strongly suggests that despite their apparent disparity, there is an underlying unity in the diseases and the treatments. The shift toward increased entropy release in the form of heat offers sound guidelines for the repurposing of drugs.","PeriodicalId":32750,"journal":{"name":"Substantia","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46204799","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Obituary: Professor Alexander Kessenikh (1932-2021)","authors":"Andrey V. Andreev, V. A. Atsarkin, Konstantin V. Ivanov, G. Kurtik, P. Lo Nostro, Vasily V. V. Ptushenko, Konstantin A. Tomilin, N. V. Vdovichenko, V. Vizgin","doi":"10.36253/substantia-1561","DOIUrl":"https://doi.org/10.36253/substantia-1561","url":null,"abstract":"On September 15, 2021, professor Alexander V. Kessenikh died. He was known for his works on nuclear magnetic resonance (NMR) and history of science.","PeriodicalId":32750,"journal":{"name":"Substantia","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43943811","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}