Mendeleev's discovery of the periodic table and the first European Academy of Sciences to honour him.

The chemical science community will commemorate the 155th anniversary of Mendeleev's groundbreaking discovery of the periodic table of elements in 2024. This paper aims to underscore the significance of Mendeleev's honorary membership in the Academy of Sciences in Zagreb, Croatia, which occurred in 1882, making it the first scientific academy in Europe to extend this recognition. Additionally, we seek to explore the contextual circumstances that contributed to this noteworthy event within the broader European context. To provide insight into the specificities and variations in the influence and reception of the periodic table of elements within the educational process of select European countries (Russia, Germany, Czech Lands, Serbia), we conducted a comprehensive review, drawing comparisons to Croatia. Notably, upon its initial publication in 1869, the discovery of the periodic table did not gain immediate acceptance in Croatia, largely attributed to the absence of a well-established presence of chemical science within the country. About fifteen years passed from Mendeleev's discovery of the periodic law to its reception and dissemination throughout Croatia. Despite an initial delay, Croatian chemical science followed the development of the periodic table through secondary and university education, while actively partaking it in.

Hydroxypropyl-ß-Cyclodextrin-Based Helichrysum italicum Extracts: Antioxidant and Cosmeceutical Activity and Biocompatibility.

Two Helichrysum italicum extracts, OPT-1 (rich in phenolic acids) and OPT-2 (rich in total phenols and flavonoids), were prepared using hydroxypropyl-ß-cyclodextrin (HP-ß-CD)-assisted extraction. The prepared extracts were rich in phenolic compounds, including flavonoids and phenolic acids. GC-MS analysis of the extracts identified neryl acetate, neo-intermedeol, ß-selinene, γ-curcumene, italidione I, and nerol as the main volatile components of the extracts, as well as plant sterols, γ-sitosterol, campesterol, and stigmasterol. The antioxidant (DPPH radical scavenging, reducing power, and a carotene linoleic acid assay) and cosmeceutical (anti-hyaluronidase, anti-tyrosinase, anti-lipoxygenase, ovalbumin anti-coagulation, and a UV-absorption assay) activity of the extracts in most of the assays was better than the activity of the applied positive controls. Especially low were the IC50 values of the extracts in the anti-hyaluronidase (14.31 ± 0.29 µL extract/mL and 19.82 ± 1.53 µL extract/mL for OPT-1 and OPT-2, respectively) and the anti-lipoxygenase (0.96 ± 0.11 µL extract/mL and 1.07 ± 0.01 µL extract/mL for OPT-1 and OPT-2, respectively) assays. The extracts were non-toxic to HaCaT cells in concentrations of up to 62.5 µL extract/mL assuring their status as excellent candidates for cosmeceutical product development appropriate for direct use in cosmetic products without solvent evaporation.

Optimization of Cyclodextrin-Assisted Extraction of Phenolics from Helichrysum italicum for Preparation of Extracts with Anti-Elastase and Anti-Collagenase Properties.

Helichrysum italicum is a plant traditionally used for skin-related disorders that is becoming an increasingly popular ingredient in cosmetic products. In this work, a "green" ultrasound-assisted extraction method for H. italicum phenolics was developed using skin-friendly cyclodextrins (CDs). Extraction conditions needed for the greatest yield of target compounds (total phenolics, phenolic acids, and flavonoids) were calculated. The composition of the extracts was determined using LC-MS and spectrophotometric methods. Among the tested CDs, 2-hydroxylpropyl-beta-CD (HP-ß-CD) was the best suited for extraction of target phenolics and used to prepare two optimized extracts, OPT 1 (the extract with the highest phenolic acid content) and OPT 2 (the extract with the highest total phenol and flavonoid content). The extracts were prepared at 80 °C, using 0.089 g of plant material/g solvent (0.6 mmol of HP-ß-CD), with or without addition of 1.95% (w/w) lactic acid. The main metabolite in both extracts was 3,5-O-dicaffeoylquinic acid. It was found that the addition of lactic acid greatly contributes to the extraction of arzanol, a well-known anti-inflammatory agent. IC50 values of the anti-elastase (22.360 ± 0.125 µL extract/mL and 20.067 ± 0.975 for OPT-1 and OPT-2, respectively) and anti-collagenase (12.035 ± 1.029 µL extract/mL and 14.392 ± 0.705 µL extract/mL for OPT-1 and OPT-2, respectively) activities of the extracts surpassed those of the applied positive controls, namely ursolic and gallic acids. This activity deems the prepared extracts promising ingredients for natural cosmetics, appropriate for direct use in cosmetic products, removing the need for the evaporation of conventional solvents.

Critical evaluation of the use of total reflection X-ray fluorescence spectrometry for the analysis of whole blood samples: application to patients with thyroid gland diseases.

Multielemental analysis of whole blood can provide significant information for the evaluation of nutritional status and diagnosis of certain diseases as well as for the assessment of exposure to potentially toxic metals. However, the quantification of multiple elements in whole blood is not easy partly because of the wide variation in element concentrations (from ng L-1 to g L-1) and the complex matrix. The aim of this work was to develop a fast, sustainable, and reliable analytical method, in combination with low-power TXRF, for multielemental analysis of blood samples. Firstly, a set of experiments were carried out to select the best diluent type and dilution factor using the control material SeronormTM Trace Elements Whole Blood L-1. A critical evaluation of the parameters affecting the sample deposition on the reflector was also carried out including a study of the shape and element distribution of the deposited residue on the reflector by micro X-ray fluorescence spectrometry. Using the best analytical conditions, limits of detection estimated were in the low milligrams per kilogram range and similar to those obtained using more complex sample treatments such as digestion. Accuracy and precision of the results were in most cases acceptable (recoveries 89-102%, RSD 6-8%, n = 5). Only underestimated values were obtained for light elements such as potassium. To prove the applicability of the method, several blood samples from control and thyroid disease patients were analyzed. Despite the fact that more samples need to be analyzed, it seems that Zn and Br contents in some of the patients are significantly higher compared to control samples. Graphical abstract.

Level of minerals and trace elements in the urine of the participants of mountain ultra-marathon race.

The aim of the present study was to explore impact of endurance exercise on urinary level of minerals and trace elements as well as on some oxidative stress and biochemical parameters. Urine samples were collected from participants (n=21) of mountain ultra-marathon race (53km; Medvednica, Zagreb, Croatia), before (baseline value), immediately after, 12h and 24h after the race. In urine samples level of minerals (Ca, P, K and Na) and trace elements (Se, Zn, Mn, Cu, Fe and Co) were assessed using the bench top Total reflection X-ray Fluorescence (TXRF) spectrometer. Oxidative stress was determined as level of malondialdehyde (MDA). Immediately after the race level of minerals, trace elements, MDA, creatinine, ketones, erythrocytes and specific gravity increased compared to their baseline value. In 24h follow-up trace elements involved in antioxidant defence, MDA and biochemical parameters returned to their baseline values, Cu and Co remained increased as after the race, Fe and K tended to return to baseline values while Ca, P and Na continued to increase. Mountain ultra-marathon resulted in alteration of physiologically important minerals and trace elements that for some minerals and trace elements persist, indicating their involvement in recovery processes. However, due to their loss in urine, level of minerals and trace elements in athletes participating in endurance exercise should be monitored.

[Humanities as a means of survival: the testimony of a Siberian prisoner of war in the First World War]. / Humanistika kao sredstvo prezivljavanja: svjedocanstvo sibirskog zarobljenika tijekom Prvog svjetskog rata.

This article looks into the autobiography of the Croatian chemist and pharmacognosist Antun Vrgoc (1881-1949) entitled My Memories of the World War 1914-1920 and published in Zagreb in 1937. The author was captured in October 1914 and deported to Siberia, where he remained prisoner of war until 1920. Since there are few memoirs describing the life of Siberian prisoners during the First World War, this work is a precious testimony about the attitude towards the prisoners of war, human relations, and the survival of an AustroHungarian army officer. The book shows a striking lack of civilian or military hostility towards the prisoners and the respect of the Geneva Convention. Antun Vrgoc adopted the culture, customs and language of his formal enemies, took part in their civilian life, and taught at their university. His cathartic experience of survival includes a clear message about the absurdity of war.

[Manuscript "Many different remedies for headache treatment" from the archives of Sinj Friary]. / "Mnoge Razlicite Likarie Od Bolesti Glave""­ Fragment Ljekaruse Iz Arhiva Franjevackog Samostana U Sinju.

Manuscripts containing collections of folk recipes for treatment of deseases were written mostly by Catholic priests especially Franciscians in Croatia in the past centuries. They were used as manuals for preparation of remedies and gave directions for their use. These writtings provide valuble data for etnographers and historians of ethnomedicine. The paper describes the manuscript "Many different remedies for headache treatment" written by unknown author probably in 18. century in Sinj, Dalmatia. The manuscript was found in the archives of Sinj Friary. The collection contains 16 recipes for headache treatment. Materia medica of the manuscript is composed of drugs of plant origin. Valuable information is given about the folk names for medicinal plants as well as descriptions of the ways of preparing remedies. Latin as well as contemporaly croatian names are attributed to the plants species mentioned in the manuscript. Use of the plants for treatment of the specific deseases were compared with their use in modern fitotherapy.