116 research outputs found
In situ Functionalized Mesoporous Silicas for Sustainable Remediation Strategies in Removal of Inorganic Pollutants from Contaminated Environmental Water
Low-cost mesoporous silicas of the SBA-15 family were prepared, aimed for removal of a broad spectrum of both cationic and anionic forms of hazardous metal pollutants (Cr(III, VI), Mn(II, VII), Pb(II), Cd(II), and Cu(II)) from environmental water. Series of mono-and bifunctional materials with immobilized ethylenediaminetriacetic acid (EDTA), primary amine (NH2), and quaternary ammonium (QAS) groups were prepared in a cost-efficient one-step synthesis using two silica sources, low-cost sodium metasilicate (Na2SiO3 9H(2)O) and the conventional source-tetraethylorthosilicate (TEOS). The functionalized SBA-15 samples obtained from both silica sources were highly ordered, as evidenced by TEM and SAXS data. All obtained materials were mesoporous with high surface area values of up to 745 m(2)/g, pore volumes from 0.99 to 1.44 cm(3)/g, and narrow pore distributions near 7 nm. The adsorption affinity of the EDTA-functionalized samples followed the common order Pb(II)> Cd(II)> Cu(II)> Cr(III)> Mn(II), which could be explained based on the Pearson theory. The highest adsorption capacities were observed for samples functionalized by EDTA groups using TEOS for synthesis (TEOS/EDTA): 195.6 mg/g for Pb(II), 111.2 mg/g for Cd(II), 58.7 mg/ g for Cu(II), 57.7 mg/g for Cr(III), and 49.4 mg/g for Mn(II). Moreover, organic matter (humic acid up to 10 mg/L) and inorganic (Na(I), K(I), Mg(II), Ca(II), etc) macrocomponents present in environmental water had almost negligible effect on the removal of these cations. The NaSi/EDTA/NH2 sample revealed a better selectivity compared to the NaSi/NH2 sample towards such species as Cr(III), Mn(II), Cd(II), and Cu(II). The chromate-ions uptake at pH 7.5 by the TEOS/QAS sample turned practically unaffected by the presence of doubly charged anions (CO32-, SO42-). The content of functional groups on the surface of MS decreased only slightly (similar to 1-5%) after several regeneration cycles. The complete desorption of all heavy metal ions can be achieved using 1 mol/L EDTA solution. Reusability tests demonstrated the complete stability of the adsorbent for at least five to six consecutive adsorption/ desorption cycles with no decrease in its adsorption characteristics compared to those obtained by 0.05 mol/L HNO3 treatments. The synthesized mesoporous materials were evaluated for removal of the heavy metal ions from drinking and different natural water samples, proving their potential as sustainable, effective, and cost-efficient adsorbents
Surface modifications based on the cyanobacterial siderophore anachelin: from structure to functional biomaterials design
This review describes the design, synthesis and evaluation of novel catechol based anchors for surface modification. The anachelin chromophore, the catecholate fragment of the siderophore anachelin from the cyanobacterium Anabaena cylindrica, allows for the immobilization of polyethylene glycol (PEG) on titania and glass surfaces thus rendering them protein resistant and antifouling. It is proposed that catecholate siderophores constitute a class of natural products useful for surface modification similar to dihydroxyphenylalanine and dopamine derived compounds found in mussel adhesive proteins. Second-generation dopamine derivatives featuring a quaternary ammonium group were found to be equally efficient in generating antifouling surfaces. The anachelin chromophore, merged via a PEG linker to the glycopeptide antibiotic vancomycin, allowed for the generation of antimicrobial surfaces through an operationally simple dip-and-rinse procedure. This approach offers an option for the prevention of nosocomial infections through antimicrobial implants, catheters and stents. Consequences for the mild generation of functional biomaterials are discussed and novel strategies for the immobilization of complex natural products, proteins and DNA on surfaces are presente
Organic gunshot residues: observations about sampling and transfer mechanisms
This work aimed at studying the sampling, storage, transfer and persistence of organic gunshot residue (OGSR), mainly stabilizers, using liquid chromatography hyphenated to mass spectrometry. Collection using swabs and stubs was compared through sequential sampling in terms of amount of residues left on the hand of a shooter. While stubs collected nearly all residues, swabs left about 50% of the residues on the hands. Moreover, the study of storage conditions after sampling showed that stubs were more stable than swabs and could be held at room temperature without significant compound loss up to two weeks. Then, shooting experiments were performed to evaluate transfer of OGSR. It was not possible to differentiate different brands of ammunition based on a single compound concentration. Moreover, a memory effect was identified when different ammunition was shot using the same firearm. Finally, various exposed skin surfaces and hair as well as clothing were sampled to estimate what surfaces might be the best targets for OGSR sampling by comparing results just after discharge and two hours after discharging a pistol. The results indicated that OGSR were more rapidly lost from hands than from clothing. Moreover, it was shown that the face and hair of a suspect might be contaminated through secondary transfer. Thus, OGSR might remain longer on other skin surfaces, hair and clothing than on the hands of a suspect. As a consequence, sampling should also include clothing, hair and face
Effect of surface chemistry of bentonite/ Mg,Fe-LDHs compositesonthe implication for environmental remediation
Melatonin in Medicinal and Food Plants : Occurrence, Bioavailability, and Health Potential for Humans
Melatonin is a widespread molecule among living organisms involved in multiple biological, hormonal, and physiological processes at cellular, tissue, and organic levels. It is well-known for its ability to cross the blood-brain barrier, and renowned antioxidant effects, acting as a free radical scavenger, up-regulating antioxidant enzymes, reducing mitochondrial electron leakage, and interfering with proinflammatory signaling pathways. Detected in various medicinal and food plants, its concentration is widely variable. Plant generative organs (e.g., flowers, fruits), and especially seeds, have been proposed as having the highest melatonin concentrations, markedly higher than those found in vertebrate tissues. In addition, seeds are also rich in other substances (lipids, sugars, and proteins), constituting the energetic reserve for a potentially growing seedling and beneficial for the human diet. Thus, given that dietary melatonin is absorbed in the gastrointestinal tract and transported into the bloodstream, the ingestion of medicinal and plant foods by mammals as a source of melatonin may be conceived as a key step in serum melatonin modulation and, consequently, health promotion
Common mechanisms of placental dysfunction in preeclampsia, gestational diabetes, and COVID-19 in pregnant women
COVID-19 infection, preeclampsia and gestational diabetes mellitus in pregnancy cause similar changes in the placenta and influence development of the fetus between conception and birth in gestation. Proper uterine and placental vascularization is essential for normal fetal development. The transplacental exchange is regulated and maintained by the placental endothelium. During placental implantation, the trophoblast differentiates into two distinct layers, the inner cytotrophoblast and outer syncytiotrophoblast, which are key elements of the human placental barrier. Proinflammatory cytokines exacerbate ischemic events and create an upward spiral of an inflammatory reaction in the placenta. Placental pathology in gestational COVID-19 shows desquamation and damage of trophoblast and chronic histiocytic intervillositis. Similar lesions also occur in gestational diabetes mellitus and preeclampsia. The systemic inflammatory response of the mother, the increased inflammation in the placenta and cytokine production by placental trophoblasts should be monitored throughout pregnancy. Placental angiogenesis can be evaluated by serum vascular endothelial growth factor, Annexin A2, placental growth factor or sclerostin. Tissue damage can be assessed by measuring levels of serum lactate dehydrogenase and myeloperoxidase. Blood flow can be monitored with three-dimensional Doppler and pathological changes can be documented with paraffin-embedded tissue sections stained with hematoxylin and eosin, and electron microscope images as well as immunohistochemistry tests for vascular endothelial growth factor, placental growth factor, sclerostin and Annexin A2. The damage of maternal and fetal vascular perfusion (villitis and fibrin deposition) is a common mechanism of gestational diseases. The placenta lesions liberate anti-endothelial factors that lead to anti-angiogenic conditions and are the common mechanism of maternal placental vascular malperfusion in gestational diseases. Keywords: dysfunction, inflammation, pathology, placenta, pregnancy, vascularizatio
Solid-phase luminescence determination of tetracycline in bottled water using chemically modified silica
Проблеми відтворення трудових ресурсів сільських територій
Павленко, Н. В. Проблеми відтворення трудових ресурсів сільських територій / Наталія Вікторівна Павленко, Світлана Юріївна Кобилінська // Сучасні проблеми правового, економічного та соціального розвитку держави : тези доп. ХІ Міжнар. наук.-практ. конф. (м. Вінниця, 9 груд. 2022 р.) / МВС України, Харків. нац. ун-т внутр. справ, Наук. парк «Наука та безпека». – Вінниця, 2022. – С. 162-163.Проведено аналіз стану відтворення трудових ресурсів у сільському господарстві, виділено декілька проблем, що виникли у цій сфері. Зазначено заходи, які сприятимуть відновленню кількості та якості робочої сили, що зайнята у сільськогосподарському виробництві, та його подальшому інтенсивному розвитку.An analysis of the state of reproduction of labor resources in agriculture was carried out, several problems that arose in this area were highlighted. Measures that will contribute to the restoration of the quantity and quality of the labor force employed in agricultural production and its further intensive development are indicated.Проведен анализ состояния воспроизводства трудовых ресурсов в сельском хозяйстве, выделено несколько проблем, возникших в этой сфере. Указаны меры, способствующие восстановлению количества и качества рабочей силы, занятой в сельскохозяйственном производстве, и их дальнейшему интенсивному развитию
Type 2 diabetes mellitus compromises the survival of diffuse large B-cell lymphoma patients treated with (R)-CHOP the PLRG report
Simvastatin and purine analogs have a synergic effect on apoptosis of chronic lymphocytic leukemia cells
Despite many therapeutic regimens introduced recently, chronic lymphocytic leukemia (CLL) is still an incurable disorder. Thus, there is an urgent need to discover novel, less toxic and more effective drugs for CLL patients. In this study, we attempted to assess simvastatin, widely used as a cholesterol-lowering drug, both as a single agent and in combination with purine analogs—fludarabine and cladribine—in terms of its effect on apoptosis and DNA damage of CLL cells. The experiments were done in ex vivo short-term cell cultures of blood and bone marrow cells from newly diagnosed untreated patients. We analyzed expression of active caspase-3 and the BCL-2/BAX ratio as markers of apoptosis and the expression of phosphorylated histone H2AX (named γH2AX) and activated ATM kinase (ataxia telangiectasia mutated kinase), reporters of DNA damage. Results of our study revealed that simvastatin induced apoptosis of CLL cells concurrently with lowering of BCL-2/BAX ratio, and its pro-apoptotic effect is tumor-specific, not affecting normal lymphocytes. We observed that combinations of simvastatin+fludarabine and simvastatin+cladribine had a synergic effect in inducing apoptosis. Interestingly, the rate of apoptosis caused by simvastatin alone and in combination was independent of markers of disease progression like ZAP-70 and CD38 expression or clinical stage according to Rai classification. We have also seen an increase in γH2AX expression in parallel with activation of ATM in most of the analyzed samples. The results suggest that simvastatin can be used in the treatment of CLL patients as a single agent as well as in combination with purine analogs, being equally effective both in high-risk and good-prognosis patients. One of the mechanisms of simvastatin action is inducing DNA damage that ultimately leads to apoptosis
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