This study investigates the extraction of rhenium using trialkylbenzyl ammonium chloride (TABAC) as an alternative to trialkylamine (TAA) for recovering rhenium from highly diluted solutions. Rhenium, present as ReO₄⁻ over a wide acidity range, was extracted via an anion exchange mechanism in single-stage experiments monitored by inductively coupled plasma mass spectrometry (ICP-MS). Key variables, including pH, acid concentration, and the concentrations of extractant and metal, were examined. The results demonstrated a high extraction efficiency exceeding 99% within a pH range of 2 to 7 and from solutions containing sulfuric or hydrochloric acid at concentrations of 0.1 to 3.0 M (mol/L). However, extraction from nitric acid solutions was less efficient, with less than 30% recovery. Performance for both TAA-kerosene and TABAC-kerosene followed the order H₂SO₄ > HCl > HNO₃. The optimal TABAC concentration was 10⁻² M (mol/L) in kerosene. TABAC also showed higher selectivity than TAA, with separation coefficients Re/Mo = 66.8 and Re/W = 55.8 in 0.1–1.0 M (mol/L) sulfuric acid. Based on equilibrium studies, the complexes formed during extraction were identified as [R₃R′NH]ReO₄. This approach may offer environmentally friendly and cost-effective benefits for large-scale industrial applications, enabling efficient recovery of valuable rhenium while reducing waste and environmental impact.

Chromium pollution has emerged as a critical environmental concern, prompting extensive research into the chemical and mineralogical properties of refined ferrochrome (RFC) slag, the leaching of chromium using sulfuric acid, and the adsorption of chromium cations onto natural zeolite. The aim of the study is to analyze the chemical and mineralogical properties of purified ferrochrome slag (RFC) from the Aktobe Ferroalloy Plant and its leaching with sulfuric acid, as well as to study the effectiveness of Shankanai zeolite in the adsorption of chromium cations from a sulfuric acid solution to improve waste management in the ferrochrome industry. Semi-quantitative X-ray analysis reveals that the dominant phase in RFC slag is olivine (50.7% Ca₂SiO₄). The optimal chromium transition rate (16.67%) occurs in dilute H₂SO₄ (23%) after 145 min of leaching, while the highest transition efficiency (18.0–18.5%) is achieved at 90 °C with a leaching duration of 145–180 min. Chromium in the RFC slag cake is predominantly in the divalent state, existing as pentahydrate chromium (II) sulfate (CrSO₄•5H₂O). The chromium sorption process was studied in a sulfuric acid solution obtained after leaching of ferrochrome slags. The process of chromium sorption by Shankanai zeolite from sulfuric acid has been studied for the first time, and the influence of the main technological parameters of the process on the degree of its purification has been established. It was determined that the highest degree of purification of a chromium-containing sulfuric acid solution is achieved with a ratio of zeolite:chromium-containing sulfuric acid solution equal to 1:10, heated to 35 °C for 15 min, and it reaches (63.6–69.0%). The natural zeolite of the Shankanai deposit is an effective, and inexpensive sorbent for cleaning aggressive media, particularly media contaminated with chromium-containing sulfuric acid. X-ray diffraction analysis further confirmed that both chromium and sulfur ions participate in the sorption process, as evidenced by microstructural changes in the zeolite, including pore filling and smoothing observed in microphotographs. These findings underscore the potential of natural zeolite as an efficient and cost-effective adsorbent for the remediation of chromium-contaminated solutions following sulfuric acid leaching. Its ability to adsorb chromium ions highlights its significant applicability in environmental cleanup efforts. This study contributes to sustainability by offering an environmentally friendly and cost-effective method for chromium removal, reducing industrial waste impact and promoting circular economy principles by utilizing natural zeolite, a readily available and recyclable adsorbent.

Acute pneumonia is frequently accompanied by immune suppression, particularly affecting T-cell subsets, such as CD4⁺, CD4⁺CD25⁺, and CD4⁺CD25⁺FoxP3⁺, which are critical for immune regulation. This study evaluates the immunomodulatory potential of a novel fluorinated piperazine-based aminophosphonate, complexed with β-cyclodextrin ((o-Fph)PPhβCD), comparing it with the clinically approved agent Polyoxidonium (PO) in a rat model of oleic acid-induced acute pneumonia. Flow cytometric analysis revealed that (o-Fph)PPhβCD significantly restored CD4⁺ and CD4⁺CD25⁺ T-cell levels and induced a sustained reduction in regulatory CD4⁺CD25⁺FoxP3⁺ cells, suggesting enhanced effector immune activity. While PO provided early immunorestorative effects, (o-Fph)PPhβCD exerted a more prolonged response, which was particularly evident by day 14. Structural confirmation of the inclusion complex was achieved through IR and NMR spectroscopy. These findings highlight (o-Fph)PPhβCD as a promising immunotherapeutic candidate that is capable of rebalancing immune cell populations and supporting host defense mechanisms during acute pulmonary inflammation.

This study investigated the effects of aseptic inflammation and heavy metal exposure on immune responses, as well as the potential immunomodulatory properties of the newly synthesized 1-[1-(2,5-dimethoxyphenyl)-4-(naphthalene-1-yloxy)but-2-ynyl]-4-methylpiperazine complexed with β-cyclodextrin (β-CD). Aseptic inflammation was induced by a subcutaneous injection of turpentine in rats, while heavy metal exposure was achieved through a daily administration of cadmium chloride and lead acetate. The levels of immune cell populations, including cytotoxic T lymphocytes (CTL), monocytes, and granulocytes, were assessed in the spleen. The results showed that aseptic inflammation led to decreased levels of CTL, monocytes, and granulocytes on the 14th day, indicating an inflammatory response accompanied by a migration of effector cells to the inflamed tissues. The exposure to cadmium chloride and lead acetate resulted in systemic immunotoxic effects, with reduced levels of B cells, CD4⁺ Th cells, monocytes, and granulocytes in the spleen. Notably, piperazine complexed with β-CD (the complex) exhibited significant stimulatory effects on CD4⁺, CD8⁺, and myeloid cell populations during aseptic inflammation, even in the presence of heavy metal exposure. These findings suggest the potential immunomodulatory properties of the complex in the context of aseptic inflammation and heavy metal exposure.

Multidentate bispidine ligands, including tetra-, penta-, hexa-, hepta-, and octadentate variants, exhibit strong coordination tendencies due to their intrinsic rigidity, significant reorganization potential, and ability to efficiently encapsulate metal ions. These structural attributes profoundly influence the thermodynamic stability, metal ion selectivity, redox behavior, and spin-state configuration of the resulting complexes. Metal ions, in turn, serve as highly suitable candidates for coordination due to their remarkable kinetic inertness, rapid complex formation kinetics, and low redox potential. This review focuses on ligands incorporating the bispidine core (3,7-diazabicyclo[3.3.1]nonane) and provides an overview of advancements in the synthesis of metal complexes involving p-, d-, and f-block elements. Furthermore, the rationale behind the growing interest in bispidine-based complexes for applications in radiopharmaceuticals, medicinal chemistry, and organic synthesis is explored, particularly in the context of their potential for diagnostic and catalytic drug development.

Leukopenia remains a major clinical challenge associated with infectious diseases, oncological therapies, autoimmune disorders, and metabolic and iatrogenic conditions. Insufficient leukopoiesis not only increases susceptibility to infections but also limits the intensity and continuity of anticancer and immunosuppressive treatments. Targeted stimulation of leukopoiesis therefore represents a critical therapeutic strategy in modern biomedicine. This narrative review summarizes pharmacological and biotechnological approaches to leukopoiesis stimulation based on an analysis of peer-reviewed literature from major biomedical databases. Emphasis was placed on molecular mechanisms of action, clinical positioning, and translational potential of leukopoiesis-modulating agents. Current leukopoiesis-stimulating strategies encompass cytokine-based therapies, bone marrow-derived peptides, thymic and microbial immunomodulators, nucleic acid-based agents, plant-derived compounds, and chemically synthesized small molecules. Classical colony-stimulating factors remain the cornerstone of clinical practice; however, their limitations, including adverse effects and restricted spectrum of action, have driven the development of alternative approaches. Emerging strategies increasingly target specific regulatory nodes of hematopoiesis, including bone marrow stromal interactions, transcription factor signaling, chemokine receptor pathways, and immune cell differentiation programs. Advances in the understanding of leukopoiesis regulation have expanded therapeutic opportunities beyond conventional growth factor administration. Pharmacological and biotechnological targeting of leukopoiesis holds promise for improving clinical outcomes in patients with leukopenia of diverse etiologies. Future progress in this field will depend on the integration of mechanistic insights with clinical evidence to enable more selective, effective, and safer leukopoiesis-stimulating therapies.