Search Results (92)

Cancer stem cells (CSCs), a subpopulation of tumor cells endowed with self-renewal capacity, drive cancer initiation and progression. While long non-coding RNAs (lncRNAs) are increasingly recognized as critical regulators of CSC stemness, their specific roles in gastric cancer stem cells (GCSCs) remain poorly understood. This study investigates the functional significance of lncRNA TSPEAR-AS2 in modulating GCSC properties and uncovers its underlying molecular mechanisms. Through integrated whole-transcriptome sequencing, bioinformatics analysis, and validation in 48 paired gastric cancer tissues and adjacent normal tissues, TSPEAR-AS2 was identified as a differentially expressed lncRNA upregulated in both GCSCs and tumor samples. Functional experiments revealed that TSPEAR-AS2 overexpression significantly enhanced GCSC sphere-forming ability, proliferation, cell cycle progression, epithelial–mesenchymal transition (EMT), and expression of stemness markers (CD54, CD44, OCT4, NANOG, and SOX2) while suppressing apoptosis. Conversely, TSPEAR-AS2 knockdown attenuated these malignant phenotypes. In vivo tumorigenicity assays in nude mice further confirmed that TSPEAR-AS2 promotes tumor growth, with overexpression accelerating and knockdown inhibiting tumor formation. Mechanistically, bioinformatics predictions and dual-luciferase reporter assays established TSPEAR-AS2 as a competing endogenous RNA (ceRNA) that sponges miR-15a-5p, thereby derepressing the miR-15a-5p target gene CCND1. Rescue experiments demonstrated that overexpression of miR-15a-5p phenocopied TSPEAR-AS2 knockdown, reducing GCSC stemness, while miR-15a-5p inhibition rescued the effects of TSPEAR-AS2 suppression. Collectively, these findings reveal a novel TSPEAR-AS2/miR-15a-5p/CCND1 regulatory axis that sustains GCSC stemness and tumorigenicity. These results highlight TSPEAR-AS2 as a potential therapeutic target for eradicating gastric cancer stem cells and improving clinical outcomes. Full article

The ability of earth-abundant metals to serve as catalysts for the oxygen reduction reaction is of increasing importance given the prominence of this reaction in several emerging technologies. It is now recognized that both the primary and secondary coordination environments of these catalysts can be modulated to optimize their performance. In this present work, we describe two Co^II complexes [Co^II(PaPy₂Q)](OTf) (1) and [Co^II(PaPy₂N)](OTf) (2) that catalyze chemical and electrochemical dioxygen reduction. Both 1 and 2 contain Co^II centers in a N₅⁻ coordination environment, but 2 has a naphthyridine group that places a nitrogen atom in the secondary coordination sphere. Solid-state X-ray crystallography and solution-state spectroscopic measurements reveal that, apart from this second-sphere nitrogen in 2, complexes 1 and 2 have essentially identical properties. Despite these similarities, 2 performs the chemical reduction of dioxygen ~10-fold more rapidly than 1. In addition, 2 has an enhanced performance in the electrochemical reduction of dioxygen compared to 1. Both complexes yield a significant amount of H₂O₂ in the chemical reduction of dioxygen (>25%). The enhanced catalytic performance of 2 is attributed to the presence of the second-sphere nitrogen atom, which might enable the efficient protonation of cobalt–oxygen intermediates formed during turnover. Full article

Ovarian cancer (OC) is the most lethal gynecologic malignancy worldwide, with high rates of disease relapse posing a significant therapeutic challenge. Consequently, there is an urgent need to develop novel treatments for OC. This study aims to evaluate the effects of the novel imipridone, ONC206, both as a monotherapy and in combination with the standard of care chemotherapy drug, cisplatin (CDDP), on human OC cell lines. In order to study the effect of ONC206 and CDDP on ovarian cancer, two cell lines, OVCAR-420 and SKOV-3, were used in this study. Cell proliferation was assessed using MTT assay while cell viability was evaluated using the trypan blue exclusion assay. Cell migration was examined using the wound healing assay. To investigate the effects of both treatments, alone or in combination on the stem-cell-like population of OC cells, the sphere-forming assay was employed. Our results revealed that ONC206, alone or in combination with CDDP, exerts a potent anti-proliferative effect on both OVCAR-420 and SKOV-3 cells, as shown in the MTT and trypan blue exclusion assays. Interestingly, a synergistic effect was observed when ONC206 was combined with CDDP, enhancing the overall anti-cancer efficacy. Additionally, ONC206 alone or in combination with CDDP inhibited the migratory ability of the ovarian cancer cells. Furthermore, the activity of ovarian cancer stem cells was inhibited when cells were treated with ONC206 alone or in combination with CDDP, as shown in the significant decrease in both the size and the sphere-forming ability of ovarian cancer stem cells in the 3D culture model. Our results highly suggest the potential of imipridones as a new class of therapeutics in ovarian cancer management. Among these, ONC206 shows nanomolar potency, highlighting its potential as a standalone therapy or in combination with existing treatment regimens. Full article

Journalists have incorporated social networks into their work as a standard tool, enhancing their ability to produce and disseminate information and making it easier for them to connect more directly with their audiences. However, this greater presence in the digital public sphere has also increased their exposure to harassment and hate speech, particularly in the case of women journalists. This study analyzes the presence of harassment and hate speech in responses (n = 60,684) to messages that 200 journalists and media outlets posted on X (formerly Twitter) accounts during the days immediately preceding and following the July 23 (23-J) general elections held in Spain in 2023. The results indicate that the most common forms of harassment were insults and political hate, which were more frequently aimed at personal accounts than institutional ones, highlighting the significant role of political polarization—particularly during election periods—in shaping the hostility that journalists face. Moreover, although, generally speaking, the total number of harassing messages was similar for men and women, it was found that a greater number of sexist messages were aimed at women journalists, and an ideological dimension was identified in the hate speech that extremists or right-wing populists directed at them. This study corroborates that this is a minor but systemic issue, particularly from a political and gender perspective. To counteract this, the media must develop proactive policies and protective actions extending even to the individual level, where this issue usually applies. Full article

Popular photoluminescent (PL) nanomaterials, such as carbon dots, have attracted substantial attention from scientists due to their photophysical properties, biocompatibility, low cost, and diverse applicability. Carbon dots have been used in sensors, cell imaging, and cancer therapy. Leek seeds with anticancer, antimicrobial, and antioxidant functions serve as traditional Chinese medicine. However, leek seeds have not been studied as a precursor of carbon dots. In this study, leek seeds underwent a supercritical fluid extraction process. Leek seed extract was obtained and then carbonized using a dry heating method, followed by hydrolysis to form carbon dot micelles (CD-micelles). CD-micelles exhibited analyte-induced PL quenching against Co²⁺ through the static quenching mechanism, with the formation of self-assembled Co²⁺-CD-micelle sphere particles. In addition, CD-micelles extracted metal ion through liquid–liquid extraction, with removal efficiencies of >90% for Pb²⁺, Al³⁺, Fe³⁺, Cr³⁺, Pd²⁺, and Au³⁺. Moreover, CD-micelles exhibited ABTS•⁺ radical scavenging ability and cytotoxicity for cisplatin-resistant lung cancer cells. CD-micelles killed cisplatin-resistant small-cell lung cancer cells in a dose-dependent manner with a cancer cell survival rate down to 12.8 ± 4.2%, with a similar treatment function to that of cisplatin. Consequently, CD-micelles functionalized as novel antioxidants show great potential as anticancer nanodrugs in cancer treatment. Full article

With the help of electrochemical methods, including CV and EIS, the influence of methimazole, carbimazole, and the concentration of the supporting electrolyte on the kinetics and mechanism of zinc electroreduction on a mercury electrode was compared and analyzed. Moreover, molecular dynamics simulations of zinc/carbimazole and zinc/methimazole solutions were carried out to determine the effect of drugs on the hydration sphere of Zn²⁺ ions. It was shown that the electroreduction of Zn²⁺ in the presence of methimazole and carbimazole occurs in two steps and the first one determines the kinetics of the entire process. The presence of both drugs in the solution and the increase in the concentration of the supporting electrolyte reduce the degree of hydration of the depolarizer ions and the hydration of the electrode surface, what is a factor favoring the rate of electroreduction. Based on theoretical studies, the formation of stable complexes between Zn²⁺ and the molecules of both drugs in a solution was considered unlikely. However, active complexes can be formed between depolarizer ions and molecules adsorbed at the electrode surface. They constitute a bridge facilitating charge exchange during the electrode reaction, revealing the catalytic abilities of methimazole and carbimazole. In the range of c_drug ≤ 1 × 10⁻³ mol dm⁻³, carbimazole is a better catalyst, whereas in the range of c_drug ≥ 5 × 10⁻³ mol dm⁻³, it is methimazole. The effectiveness of both compounds in catalyzing the first stage of the electrode reaction increases with the increase in the NaClO₄ concentration. Full article

Alumina (Al₂O₃) particles, the primary combustion products of solid rockets, can accumulate in the stratosphere, changing the global radiative balance. These Al₂O₃ particles were usually treated as homogeneous spheres. However, they contain impurities and may form clusters during the combustion process. Models representing Al-containing and C-containing Al₂O₃ clusters were developed, denoted as Al₂O₃ shell model (ASM) and Al₂O₃ core model (ACM), respectively. The superposition T-matrix method (STMM) was applied to examine their optical characteristics. Subsequently, a method to obtain the top-of-atmosphere flux was proposed by integrating the models with the moderate resolution atmospheric transmission code (MODTRAN). With the addition of Al/C, the absorption cross-section enhances by several orders of magnitude at 0.55 μm and increases slightly at 10 μm. The equivalent sphere models will weaken their scattering ability. A 4Tg mass burden of Al₂O₃ produces radiative forcing of −0.439 Wm⁻². However, the addition of Al and C reduces the forcing by up to 15% and 12%, respectively. In summary, the optical characteristics and radiative forcing of Al₂O₃ clusters are sensitive to Al/C and morphology models. While our findings are impacted by various uncertainties, they contribute valuable insights into the radiative forcing of Al₂O₃ particles, potential climatic changes by space activities. Full article

The purpose of the article was to investigate the potential of rural green tourism in Ukraine and to determine the main directions of its innovative development, taking into account global, national, and regional trends. SLR (Systematic Literature Review), methods of expert assessment, selective observation, and graphic method were used to achieve the set goal. The article analyzes the current state of rural green tourism in Ukraine; the tourism and recreation potential of rural areas of Ukraine was assessed; promising types of innovations that are currently relevant for implementation in the practice of providing services in the field of rural green tourism in Ukraine are defined and grouped; and the impact of global, national, and regional trends on the current stage of activity and further development of rural green tourism in Ukraine is determined. It is determined that in modern economic conditions, rural tourism serves as a stabilizing factor that will contribute not only to maintaining the normal living standards of rural residents, but also to the development of the region’s economy, service infrastructure, household services, and the social sphere. Thus, rural green tourism is the main tool for stimulating the economic and socio-cultural development of rural areas. The results of the assessment of the tourist and recreational potential of rural green tourism of Ukraine showed that the recreational and tourist attractiveness of rural areas is mainly determined by natural and ecological conditions, cultural and historical conditions, and the tourist infrastructure of the region. Financial economic, socio-demographic, and administrative management conditions negatively affect the recreational and tourist attractiveness of rural areas, resulting in the low ability of the rural population to implement innovations. It has been established that in order for the tourist business to be able to quickly adapt to the normal state, it is necessary to introduce innovative types of tourism that will make it possible to attract a larger number of people to the tourist business and establish additional income due to the introduction of innovative offers, new tours, visits to special places, and the entire range of services of the best quality, which will contribute to the accelerated implementation of online forms and digital tools in the provision of tourist services, etc. It has been proven that the introduction of innovations plays an important role in ensuring the sustainable and balanced development of rural tourism in Ukraine, contributing to the creation of new opportunities and improving the quality of tourist services. Full article

Glioblastoma (GBM) poses a significant challenge in clinical oncology due to its aggressive nature, heterogeneity, and resistance to therapies. Cancer stem cells (CSCs) play a critical role in GBM, particularly in treatment resistance and tumor relapse, emphasizing the need to comprehend the mechanisms regulating these cells. Also, their multifaceted contributions to the tumor microenvironment (TME) underline their significance, driven by their unique properties. This study aimed to characterize glioblastoma stem cells (GSCs), specifically slow-cycling cells (SCCs), in an immunocompetent murine GBM model to explore their similarities with their human counterparts. Using the KR158 mouse model, we confirmed that SCCs isolated from this model exhibited key traits and functional properties akin to human SCCs. KR158 murine SCCs, expanded in the gliomasphere assay, demonstrated sphere forming ability, self-renewing capacity, positive tumorigenicity, enhanced stemness and resistance to chemotherapy. Together, our findings validate the KR158 murine model as a framework to investigate GSCs and SCCs in GBM pathology, and explore specifically the SCC–immune system communications, understand their role in disease progression, and evaluate the effect of therapeutic strategies targeting these specific connections. Full article

Planar light concentrators are potential applications for solar thermal conversion, in which the intensity of the electric field will exhibit strongly non-uniform characteristics. However, previous research has long ignored the solar absorption performance of plasmonic nanoparticles in the focused electric field. In this work, we use the finite element method (FEM) to study the optical behaviors of a single nanoparticle and multiple nanoparticles in the focused electric field formed by vertically and inwardly imposing the initial incident light on a quarter cylindrical surface. The results show that the focused electric field can significantly improve the solar absorption abilities compared with the parallel one for all the nanoparticles due to the local near-electric field enhancement caused by the aggregation of the free electrons on the smaller zone. Further studies on the focused electric field reveal that the plasmon heating behavior of Au spheres presents a rising trend with the decrease in inter-particle spacing, as the gap is less than the radius of Au spheres. As the number of nanoparticles increases along the focal line, the absorption power of the center nanoparticles gradually tends to be stable, and it is much lower than that of a single nanoparticle. As the nanoparticles are arranged along the y and z directions, the heterogeneity of the electric field makes the optical properties uneven. Notably, the strongest electric field appears slightly close to the incident surface rather than on the focal line. Full article

The enigmatic 72 Verses for St. Martial is one of the many works by Ademar de Chabannes (989–1034) crafted to promote the false narrative that St. Martial of Limoges, rather than being a third-century bishop, was actually a first-century apostle. The composition is visually striking due to the acrostic formed from the first letter of each tercet, MARCIALIS APOSTOLVS XRISTI, and its two overlapping melodies, one in black ink and the other in red. The relationship between the two notations is the subject of debate: Paul Hooreman’s conclusion that they are two variations of the same monophonic chant is countered by Manuel Pedro Ferreira, who argues that Hooreman’s reasoning is insufficient to rule out polyphony. I use Ferreira’s assessment as a jumping-off point for the current analysis, which investigates the compositional processes underlying the creation of the 72 Verses. Hooreman describes many details in the chant as subject to disorganization, scribal error, lack of ability, etc., but when the chant is analyzed polyphonically, these problems resolve. Beyond the music itself, the chant’s unusual polyphonic structure features reveals that the chant is structured around medieval maps, moving between a mappa mundi and the celestial spheres. Full article

Iron hydroxyl sulfate minerals (IHSMs, including schwertmannite and jarosite) are a promising material for environmental applications with excellent adsorption of metal oxygen anions. The acid mine drainage (AMD) abundant in iron and sulfate ions holds potential for the production of valuable IHSMs, thereby achieving resource recycling whilst simultaneously mitigating water contamination, which is important for the sustainable remediation of AMD. Conventional mineralization, which promotes the generation of minerals from Fe³⁺ and SO₄²⁻ through the energy provided by chemical or biological oxidation, can only partially mineralize iron in AMD containing substantial quantities of Fe²⁺. In this study, an improved method for mineralizing AMD containing iron of a different valence into IHSMs under the induction of KHCO₃ was proposed. For AMD containing Fe²⁺, the combination of KHCO₃ and H₂O₂ was used to promote the hydrolysis of iron (92.7%) and sulfate (11.1%) into IHK minerals, which resulted in a significant increase in iron removal of 75.2% and a minor increase in sulfate removal of 4.9%, compared with the formation of schwertmannite from oxidation solely involving H₂O₂. For the AMD containing Fe³⁺, the energy generated by the acid–base reaction in water could also directly promote the formation of IK minerals from 97.2% iron and 6.9% sulfate. XRD and FTIR analyses confirmed the identification of the IHK and IK minerals as IHSMs transitioning from schwertmannite to jarosite. SEM and elemental analyses indicated that the mineral exhibited denser aggregate spheres with the incorporation of KHCO₃ in mineralization yet displayed enhanced mineralization abilities for the contaminant ions in AMD. Moreover, despite the SSA of the modified minerals being diminished (2.02, 1.83 and 1.83 m²/g for IH, IHK and IK, respectively), the presence of more sulfate in the mineral enhanced the adsorption capacity of Cr(VI). Furthermore, the water quality results also illustrated that the removal ratios of iron and sulfate in AMD notably increased with the involvement of KHCO₃ in mineralization. In conclusion, the KHCO₃-induced mineralization of iron-containing (either divalent or trivalent) AMD into IHSMs not only improved the mineralization ratios and contaminant removal ratios for better remediation of AMD but also obtained mineral resources with better adsorption of Cr(VI), thereby fostering the sustainable advancement of the remediation of AMD. Therefore, this innovative strategy employing KHCO₃-assisted chemical mineralization to form IHSMs holds ample potential and promises to be an efficacious methodology for the sustainable remediation of iron-rich AMD. Full article

Head and neck squamous cell carcinoma (HNSCC) is a very heterogeneous cancer with a poor overall response to therapy. One of the reasons for this therapy resistance could be cancer stem cells (CSCs), a small population of cancer cells with self-renewal and tumor-initiating abilities. Tumor cell heterogeneity represents hurdles for therapeutic elimination of CSCs. Different signaling pathway activations, such as Wnt, Notch, and Sonic-Hedgehog (SHh) pathways, lead to the expression of several cancer stem factors that enable the maintenance of CSC features. Identification and isolation of CSCs are based either on markers (CD133, CD44, and aldehyde dehydrogenase (ALDH)), side populations, or their sphere-forming ability. A key challenge in cancer therapy targeting CSCs is overcoming chemotherapy and radiotherapy resistance. However, in novel therapies, various approaches are being employed to address this hurdle such as targeting cell surface markers, other stem cell markers, and different signaling or metabolic pathways, but also, introducing checkpoint inhibitors and natural compounds into the therapy can be beneficial. Full article

Based on evidence collected in a collaborative research project, this article studies the Black Coalition for Rights created in Brazil in 2019. Compared to previous experiences of antiracist struggles in Brazil, the Coalition stands out for its decentralized organization, its ability to convey political content through adequate aesthetic forms, its capillarity in the domestic sphere, and its transnational articulations. Equally striking is its intersectional character understood as both the emphasis on the transversal character of racism and the stress of the interdependent character of social struggles against different forms of inequalities (with regard to gender, race, class, etc.). The Coalition has so far proven to be particularly successful in terms of its mobilization capacity, its public visibility, and its agenda-setting power. According to our preliminary findings, its success can be explained, to a great extent, by its ability to vocalize a broad set of political claims and, consequently, to fill the gap left by other civil society actors demobilized by the far right-wing backlash in Brazil and the pandemic. Since January 2023, in the context of a new progressive government, the Coalition has started facing difficulties in preserving its intersectional and socially encompassing character. Full article

The anterior lens epithelium has the ability to differentiate into lens fibres throughout its life. The present study aims to identify and functionally characterize the adult stem cells in the human lens epithelium. Whole mounts of lens epithelium from donor eyes (normal/cataract) were immunostained for SOX2, gap junction protein alpha 1 (GJA1), PAX6, α, β and γ-crystallins, followed by a confocal analysis. The functional property of adult stem cells was analysed by their sphere forming ability using cultured lens epithelial cells from different zones. Based on marker expression, the lens epithelium was divided into four zones: the central zone, characterized by a small population of PAX6⁺, GJA1⁻, β-crystallin⁻ and γ-crystallin⁻ cells; the germinative zone, characterized by PAX6⁺, GJA1⁺, β-crystallin⁻ and γ-crystallin⁻; the transitional zone, characterized by PAX6⁺, GJA1⁺, β-crystallin⁺ and γ-crystallin⁻; and the equatorial zone, characterized by PAX6^+/−, GJA1⁺, β-crystallin⁺, and γ-crystallin⁺ cells. The putative lens epithelial stem cells identified as SOX2⁺ and GJA1 membrane expression negative cells were located only in the central zone (1.89 ± 0.84%). Compared to the other zones, a significant percentage of spheres were identified in the central zone (1.68 ± 1.04%), consistent with the location of the putative adult lens epithelial stem cells. In the cataractous lens, an absence of SOX2 expression and a significant reduction in sphere forming ability (0.33 ± 0.11%) were observed in the central zone. The above findings confirmed the presence of putative stem cells in the central zone of the adult human lens epithelium and indicated their probable association with cataract development. Full article