The ion selectivity of [2 Qua.2 Qua.2 Qua] was investigated based on descriptors derived from quantum chemical calculations (B3LYP/LANL2DZp), including structural aspects and model reaction energies. The results clearly show that the cryptand [2 Qua.2 Qua.2 Qua] demonstrates the same ion selectivity as the earlier investigated cryptands [2 Oxa.2 Oxa.2 Oxa] and [2.2.2]. There is a clear preference for K<sup>+</sup> (over Rb<sup>+</sup>) and Ba<sup>2+</sup> (over Sr<sup>2+</sup>). The substitution of the oxalic acid or ethyl moieties by the quadratic acid block, with its sp<sup>2</sup>-carbon cycle, makes the cryptates [M ⸦ 2 Qua.2 Qua.2 Qua]<sub>m+</sub> less flexible in comparison to [M ⸦ 2 Oxa.2 Oxa.2 Oxa]<sub>m+</sub> and [M ⸦ 2.2.2]<sub>m+</sub>. To compensate for the quadratic acid-based inflexibility, the cryptand [2 Qua.2 Qua.2 Qua] utilizes twisting the CN⸱⸱⸱NC angle to improve the coordination of guest cations and nest them in a better way in [2 Qua.2 Qua.2 Qua].

The Eurasian Eagle-owl represents a widely distributed but locally scarce apex predator whose biology and ecology in Serbia remain understudied. Here, we examined the spatial and altitudinal distribution, population size, and territory density of this species in Eastern Serbia. Our surveys identified 79 owl territories spread across 51 10×10 km UTM squares, resulting in a mean density of 0.5 territories/100 km². The territories were unevenly distributed, primarily concentrated in hilly terrains, river valleys and along mountain edges. The altitudinal range of identified territories spanned from 65 to 645 m, with the majority located in hilly zones below 500 m. Notably, we discovered 42 new, previously undocumented territories. Based on the collected data and habitat modelling, we estimate that the number of Eagle-owl territories in Eastern Serbia ranges from 135 to 170. Our findings contribute to a better understanding of the species' ecology and form a solid framework for future studies.

The impact of a small hydropower plant (SHP) on aquatic communities (benthic algae, macroinvertebrates and ichthyofauna) and water quality was investigated in the Panjica River (Serbia). The field research was conducted at three localities in November 2024. The results showed differences in community composition between localities upstream and downstream of the SHP, with the greatest impact observed immediately downstream of the water intake. A decline in benthic diatom and macroinvertebrate diversity was observed. Non-diatom algae more clearly indicated the changes in habitat conditions caused by the SHP's operation, as evidenced by the excessive growth of the cyanobacterium Microcoleus autumnalis. The greatest impact was observed in the ichthyofauna, which was absent at the site immediately downstream of the SHP. The ecological status assessment based on diatoms showed no differences, while the macroinvertebrates indicated a deterioration in water quality downstream of the SHP. Long-term monitoring is recommended to better assess SHP's impact.

One fundamental question is the connection between electrical and gravitational forces. We present a quantum entanglement model, with multiple discrete electrically charged wave-packets, that simulates gravitational attraction among them, where quantum states can have only two wave-packets with opposite charge polarities, with equal absolute values, while the rest remain neutral, relating those charges to gravitational masses. We present a thought experiment where neutrons are displaced by electric fields above the Schwinger limit, predicting their maximum possible corresponding displacement magnitudes and diminishments in their gravitational masses (with increments elsewhere), estimating an upper bound for the gravitational mass of each of those entangled wave packets allegedly constituting those neutrons. Thus, the realization of the experiment could verify the predictions, but cannot necessarily falsify the model. The model's significance rests in hypothesizing entanglements in a classical mechanical property without violating the measurement independence postulate and in its possible applications for gravity simulations with quantum systems.

Resveratrol exerts neuroprotective effects that are not only due to anti inflammatory and antioxidant activity but also by launched biogenesis via sirtuin-1 (SIRT1) protein that protects cells from oxidative stress. Resveratrol has low bioavailability due to low aqueous solubility and rapid metabolism. To improve the pharmacological profile, one of the strategies is the structural modification and selecting an analogue that would activate SIRT1 and improve pharmacokinetics. The aim was to examine the neuroprotective potential of resveratrol analogues through the analysis of the binding affinity to the sirtuin-1 receptor and with improved permeability through the blood-brain barrier. 15 of them have a higher affinity for the target. Four analogues are characterized by better properties including both higher permeability and higher binding affinity for SIRT1 compared to resveratrol. The selected compounds are assumed to have better bioavailability and CNS distribution, and further studies are proposed to confirm their effects and use as neuroprotective agents.

Dexamethasone is a synthetic glucocorticoid commonly used in both human and veterinary medicine. Prolonged treatment with dexamethasone can lead to serious metabolic side effects such as insulin resistance and diabetes. In this study, the morphological, immunohistochemical, and ultrastructural changes in the rat pancreatic islets were investigated after dexamethasone treatment (2 mg/kg, intraperitoneally for 12 days). The results showed that the volume density, mean diameter and profile area of islets were significantly increased in dexamethasone-treated animals. The volume density, profile area and mass of B-cells increased, whereas the volume density of A-and D-cells decreased, as did the number of A-cells per mm 2 of islet. Mild insulin immunopositivity of the centrally located B-cells together with altered ultrastructural features indicated their loss of function. The results of the present study suggest adverse effects of dexamethasone on pancreatic endocrine function that may ultimately seriously affect glucose homeostasis.

Colorectal cancer is one of the leading causes of mortality worldwide. It is the most common malignancy and there is a need for new approaches in therapies. Surgery, radiation and chemotherapy are the key components of colon cancer treatment. Besides common chemotherapy, alternative therapies are being studied to increase treatment effectiveness and reduce side effects. In this article, colorectal carcinoma cells were treated with chemotherapeutics and relative gene expression was investigated for the genes coding cytoskeleton proteins: CDH1, CTNNB1 and CDH2; for redox status genes: GPX1, GPX2, GPX3, GPX4, TXNRD1, GSTP1, NFE2L2, NFKB1, HIF1A; and for apoptosis genes: CASP3, CASP8, CASP9, FAS, BCL-2 and BAX. The results of our research showed that some concentrations of chemotherapeutics increased the expression of certain genes. Molecular alterations that lead to colorectal cancer can determine appropriate and effective treatment - chemotherapeutics, as well as the design of direct therapeutic targets.

The ginger species (Zingiberaceae family) have attract a lot of scientific attention because of their perceived beneficial effects on health. Despite this, for the numerous species of the family, scientific reports are quite scarce and warrant further analyses. The most of until now analyzed ginger species are allochthonous in the Philippines. Thus, this study was carried out to determine the total phenolic content and antioxidant activity of the ethanolic extracts of the leaves and rhizomes of Etlingera dostseiana Naive, Demayo & Alejandro, a Philippine endemic ginger species. Data recorded for total phenolic content (mg GAE/g dried sample) revealed that the leaves (15.44 ± 0.80) have a greater amount of phenolics than the rhizomes (0.59 ± 0.03). The total antioxidant activity (mg AAE/g dried sample) was also observed to be higher in leaves (14.24 ± 0.25) than in the rhizomes (0.91 ± 0.04), as well as the reducing power (mg GRPE/g dried sample) - 10.33 ± 1.13 in leaves versus 0.21 ± 0.06 in rhizomes. Based on the correlation analysis, a perfect positive linear relationship was observed among the total phenolic content, total antioxidant activity, and reducing power (r=1, p<0.001). These imply that the high contents of phenolic compounds contribute to the antioxidant activity of extracts of E. dostseiana. It can be regarded that E. dostseiana could be a candidate as a natural plant source of antioxidant compounds.

In this study, the allelopathic potential of aqueous extracts of Codiaeum variegatum L. Rumph. Ex A. Juss. (40%, 20%, 10%, 5%, 2.5%, and 1.25%) on germination, early growth, and physiological activity of the selected plant recipient Lolium perenne L. was investigated. The obtained results confirmed the existence of allelopathic potential, which differed in its possibilities of adverse effects on the morphological and physiological characteristics of the recipient plant. The monitoring of the germination characteristics of the recipient plant showed that the tested extracts exhibited a concentration-dependent effect, i.e., stronger concentrations had a stronger inhibitory effect. A weaker negative effect on the growth of the selected species was observed, and it was shown that the root length of the seedling was usually under the stronger inhibitory effect of higher concentrations of extracts, in contrast to the length of the shoot, where all the applied extracts had a significant stimulatory effects. Moreover, allelochemicals of C. variegatum were shown to interfere with the synthesis of phenolic compounds and antioxidant capacity of L. perenne seedlings, the values of which decreased with increasing concentration of test extracts.

Mucopolysaccharidosis type II or Hunter syndrome is a hereditary, progressive disease that occurs due to the deposition of acidic glucosaminoglycans in lysosomes, due to hereditary deficits of specific degradation enzymes. A two-year-old boy was hospitalized and diagnosed with macrocephaly, hepatomegaly and at the age of four, an iduronate 2-sulfatase (IDS) gene analysis was performed and a mutation on the 3rd exon (c.262C>T, p.R88C) on the X chromosome was determined. Only four years after the diagnosis of Hunter syndrome, the boy begins to receive enzyme therapy - the drug Elaprase. During the period of receiving therapy, the boy's progression of the disease was significantly reduced.