搜索结果：Akademii

The 3' untranslated region of mRNAs are involved in post-transcriptional control, influencing mRNA stability, localization, and translation efficiency through its interaction with various proteins and RNAs. While eukaryotic 3' UTRs are typically several hundred nucleotides long, certain protozoan species possess remarkably short 3' UTRs and have evolved alternative genetic codes where canonical stop codons are reassigned to sense codons. This suggests a potential link between 3' UTR architecture and the efficiency of translation termination. In this study, we investigate how the length and secondary structure of the 3' UTR modulate translation termination efficiency across different species. We demonstrate that shortening of structured 3' UTRs confer a translational advantage for mRNAs bearing UAA stop codons. Using purified pre-termination complexes, we show that 3' UTR secondary structures enhance the termination rate by facilitating the spatial proximity of PABP (bound to the poly(A) tail) to eRF3a on the ribosome. Furthermore, we found that the termination rate at UGA stop codons is highly sensitive to 3' UTR length when assayed with both human and ciliate release factors. Our investigation of stop codon reassignment underscores the primary role of release factor recognition efficiency in this process. Collectively, our findings reveal a dual regulatory mechanism: while long, structured 3' UTRs can sterically hinder stop codon recognition, they simultaneously promote eRF3a-PABP interactions that facilitate the recruitment of release factors to the ribosome. This work establishes 3' UTR length as a key cis-regulatory factor fine-tuning the fundamental process of translation termination.

The parti-coloured bat (Vespertilio murinus) is a widely distributed species across Eurasia, notable for its facultative, seasonally occurring male-only colonies, which are uncommon in the bat world. Males benefit from social warming and social foraging during spermatogenesis. However, little is known about the relatedness between individuals within these groups. Our aim was to create a panel of microsatellite loci for use in genetic studies of parti-coloured bats, as understanding the evolutionary mechanisms leading to male sociality cannot be done without using genetic techniques. Of 27 microsatellite loci that had previously been used for other species of the Vespertilionidae family, we selected 12 that provided reliable quality results with Vespertilio murinus samples. The number of alleles at each locus ranged from 3 to 40, and observed heterozygosity ranged from 0.002 to 0.589. Almost all markers showed a departure from Hardy-Weinberg equilibrium and presence of null alleles. The presented microsatellite panel will be a valuable tool for studying the genetic relatedness of male colonies of parti-coloured bats.

During the September 2024 Science Festival in Warsaw, three unique events were organized in collaboration between the Nencki Institute of Experimental Biology PAS, the Academy of Fine Arts in Warsaw, and the Marceli Nencki Foundation for the Advancement of Biological Sciences. These events focused on exploring interactions between biological sciences and visual arts. As part of this collaboration, an exhibition titled “Vibration” was presented at the Hermitage in the Royal Łazienki Park. Additionally, lectures and an exhibition titled “Can Molecular Biology Inspire Visual Artists” were held at the Nencki Institute PAS. A unique event, the “Bio-Workshop”, was organized for high school students at the Graphic Arts Department of the Academy of Fine Arts in Warsaw. In addition to recounting and detailing these events, this article presents a broader context of the interplay between art and natural sciences. The benefits of creative interdisciplinary activities are discussed, highlighting the potential for mutual inspiration between these two fields, benefiting both artists and scientists. Podczas wrześniowego Festiwalu Nauki 2024 w Warszawie odbyły się trzy wyjątkowe wydarzenia zorganizowane we współpracy Instytutu Biologii Doświadczalnej im. M. Nenckiego PAN, Akademii Sztuk Pięknych w Warszawie oraz Fundacji Marcelego Nenckiego Wspierania Nauk Biologicznych. Spotkania te koncentrowały się na eksplorowaniu interakcji między naukami biologicznymi a sztukami wizualnymi. W ramach tej współpracy przygotowano wystawę pt. "Rozedrganie", która została zaprezentowana w Ermitażu w Łazienkach Królewskich. Ponadto, w Instytucie Nenckiego PAN odbyły się wykłady oraz wystawa prac studentów ASP zatytułowana "Czy biologia molekularna może inspirować artystów sztuk wizualnych?". Dla uczniów szkół średnich zorganizowano unikatowe wydarzenie - "Bio-Mikroplener", które miało miejsce na Wydziale Grafiki Akademii Sztuk Pięknych w Warszawie. W artykule, oprócz relacji i szczegółowego opisu tych wydarzeń, przedstawiono szerszy kontekst oddziaływań między sztuką a naukami przyrodniczymi. Omówiono korzyści płynące z kreatywnych działań interdyscyplinarnych, zarówno dla artystów, jak i naukowców, podkreślając potencjał wzajemnego inspirowania się tych dwóch dziedzin.

The Escherichia coli bacterium is presented from its discovery in 1885 by the German-Austrian microbiologist and pediatrician Theodor Escherich, to contemporary research using state-of-the-art experimental and bioinformatic techniques, including artificial intelligence and machine learning. E. coli accompany humans from birth as a commensal organism of the gut microbiota. However, some E. coli strains exhibit pathogenic properties, causing intestinal and extraintestinal diseases, sometimes threatening the health and even life of the host. At the same time, 140 years after the discovery of E. coli bacteria, it is the best-studied single-celled organism in the world. Molecular biologists, bacteriologists, and biochemists point to the enormous importance of E. coli as a model organism in understanding the molecular mechanisms of key life processes in both health and disease, as well as its use in industrial-scale biotechnology. That is why E. coli is called the “workhorse of molecular biology and biomedicine,” and scientists working with E. coli strains have been recognized and honored for their discoveries with numerous Nobel Prizes. Przedstawiono bakterię Escherichia coli, od jej odkrycia w 1885 roku przez niemiecko-austriackiego mikrobiologa i pediatrę Theodora Eschericha, po współcześnie prowadzone badania z zastosowaniem najnowocześniejszych eksperymentalnych i bioinformatycznych technik włączając AI i uczenie maszynowe. Bakteria E. coli towarzyszy człowiekowi od urodzenia jako komensalny organizm mikrobioty jelitowej, niemniej część szczepów E. coli wykazuje właściwości patogenne, wywołując schorzenia jelitowe i pozajelitowe, niekiedy zagrażające zdrowiu, a nawet życiu gospodarza. Jednocześnie, po upływie 140 lat od odkrycia bakterii E. coli jest to najlepiej zbadany jednokomórkowy organizm na świecie. Biolodzy molekularni, bakteriolodzy, czy biochemicy wskazują na ogromne znaczenie E. coli jako modelowego organizmu w poznaniu molekularnych mechanizmów kluczowych procesów życiowych zarówno w warunkach zdrowia jak i choroby oraz jego wykorzystania w biotechnologii na skalę przemysłową. Stąd bakteria E. coli określana jest jako "workhorse of molecular biology and biomedicine", zaś badacze pracujący ze szczepami E. coli zostali docenieni i uhonorowani za swoje odkrycia wieloma Nagrodami Nobla.

Obsidian is a natural glass that is a common product of silicic volcanic eruptions. It has been prized throughout human history for its glassy nature, finding use in tools, weapons and ornaments, and in ritual and spiritual practice. The absence of large crystals in obsidian has led to the widespread view that it is formed by rapid cooling of lava, preventing crystal nucleation and growth. Here we show that, on the contrary, the absence of vesicles in obsidian requires relatively slow cooling - on the order of 10-4 to 10-8 °C/s - to enable the resorption of remnant bubbles. Our bubble-resorption model for obsidian formation is supported by in-situ X-ray computed tomography at magmatic temperatures that reveals bubble shrinkage during resorption on cooling. We validate a numerical model for growth and resorption of bubbles against these results, then apply the model to explore the conditions under which obsidian can form in nature. Our findings revise the accepted thermal histories of obsidian-forming systems, overturning conventional wisdom for the formation of this culturally, archaeologically, and volcanologically important material.

暂无摘要（点击查看详情）

Secondary metabolites, which are natural products of fungi, perform key biological functions and have applications in medicine. The production of these compounds is subject to the control of clusters of biosynthetic genes located within the genome. It has been observed that these genes can become dormant under standard culture conditions. The advent of modern genetic and epigenetic methodologies has rendered the activation of these elements possible, thus facilitating the identification of novel bioactive compounds. The present article delineates classes of metabolites, the mechanisms of their biosynthesis, and current research strategies, combining knowledge from biology, genetics, and biotechnology. Produkty naturalne grzybów, zwane metabolitami wtórnymi, pełnią kluczowe funkcje biologiczne i mają zastosowanie w medycynie. Ich produkcja jest kontrolowana przez zgrupowane w genomie klastry genów biosyntetycznych, które mogą być uśpione w standardowych warunkach hodowli. Dzięki nowoczesnym metodom genetycznym i epigenetycznym możliwe jest ich aktywowanie, co pozwala odkrywać nowe związki bioaktywne. Artykuł przedstawia klasy metabolitów, mechanizmy ich biosyntezy oraz aktualne strategie badawcze, łącząc wiedzę z zakresu biologii, genetyki i biotechnologii.

The claustrum, a subcortical structure densely expressing 5-hydroxytryptamine 2 A (5-HT2A) receptors, has been implicated in sensory integration, emotional regulation, salience, and attention. Despite its hypothesized involvement in the effects of serotonergic psychedelics, the neurochemical impact of these substances on claustral neurotransmission remains unexplored. This study aimed to investigate how psilocin — a tryptamine and the active metabolite of psilocybin — and 4-Iodo-2, 5-dimethoxy-N-(2-methoxybenzyl)phenethylamine (25I-NBOMe) — a phenethylamine and new psychoactive substance (NPS) — modulate extracellular neurotransmitter levels in the rat claustrum, as well as to examine their effects on wet dog shake behavior, a well-established proxy for hallucinogenic activity. Adult male Wistar Han rats were used for in vivo brain microdialysis experiments. Microdialysis probes were stereotaxically implanted into the claustrum. Rats received local administration of either psilocin (100 or 500 µM) or 25I-NBOMe (500 µM) through the microdialysis probe. Dialysate samples were collected and analyzed using high-performance liquid chromatography (HPLC) with electrochemical detection to quantify extracellular levels of dopamine (DA), noradrenaline (NA), serotonin (5-HT), glutamate (GLU), gamma-aminobutyric acid (GABA), and acetylcholine (ACh). A behavioral test defined as wet dog shakes (WDS) was conducted after drugs administration, to infer psychedelic-like activity. In vivo microdialysis performed in freely moving rats revealed that both substances markedly altered extracellular levels of DA, NA, 5-HT, GLU, GABA, and ACh. Psilocin, at both administered doses, was the only compound to significantly elevate NA and produced the most pronounced enhancement of cholinergic signaling across all neurotransmitter systems examined. By contrast, 25I-NBOMe induced a more substantial shift toward excitatory dominance, accompanied by the greatest increase in 5-HT release. Overall, psilocin generated a comparatively balanced excitatory–inhibitory neurochemical profile, reflecting its combined engagement of 5-HT2A and 5-HT1A receptors, whereas 25I-NBOMe produced an excitation-biased pattern consistent with its selective, high-affinity 5-HT2A agonism. These findings highlight the claustrum as a neurochemical convergence point for psychedelic action and demonstrate that psilocin engages this circuitry in a regulated, receptor-balanced manner, whereas 25I-NBOMe drives a markedly more excitatory and less compensated profile, underscoring their fundamentally distinct therapeutic and toxicological potentials. The online version contains supplementary material available at 10.1007/s43440-025-00817-3.

This study examines the utilisation of fly ash from the energy sector as a secondary raw material in cement composites, with the aim of improving sustainability while maintaining high mechanical performance. By partially replacing Portland cement with industrial by-products, the proposed approach supports resource efficiency and aligns cement composite production with circular economy principles. Three formulations were tested: a reference mix and mixes with 25% and 50% cement reduction. Compressive strength reached 41 MPa, confirming suitability for construction use. Chemical and textural properties were analysed using XRD, FTIR, TGA, and nitrogen adsorption (BET, BJH). The results showed structural modifications, including new crystalline phases and changes in porosity. XRD confirmed newly formed phases, while FTIR identified Si-O-Si and Al-O-Si bonds, indicating effective activation of fly ash. Reducing cement content increased surface area and mesoporosity, enhancing performance. The findings demonstrate that fly ash can serve as a sustainable substitute for Portland cement within a circular economy framework, supporting CO2 emission reduction and resource conservation while enabling the production of durable and environmentally responsible cement composites.

暂无摘要（点击查看详情）

Throughout Earth's history, eruptions from volcanic fissures have been responsible for some of the largest outpourings of basaltic magma, impacting climate and society. In continental monogenetic settings, these eruptions can occur on short timescales and with short notice after long quiescence. Their deposits are often quickly destroyed or buried as the eruption progresses, limiting understanding of eruption triggers and hazards uniquely garnered from these tephra layers and lavas. The ~37 ka Budj Bim Volcanic Complex (BBVC) in the active intracontinental monogenetic Newer Volcanics Province (NVP), southeastern Australia (~4.5 Ma to present), is a rarely preserved volcanic fissure system that provides new insight on how magma ascent dynamics impact eruptions. The BBVC comprises a 2.2 km long array of basaltic scoria cones, spatter cones, an elongate open crater with steep inward-sloping walls and a substantial lava-tube-fed flow field. Newly logged eruption sequences, petrography and geochemical analysis reveal five eruption stages, involving vent-shifting along a dyke-fed fissure, and rapid changes in eruption styles between Strombolian and micro-Plinian activity interspersed with concurrent and intermittent phreatomagmatism. The eruption culminated in the establishment and then breach of an elongate lava lake, feeding the > 30 km long culturally significant Tyrendarra lava flow (UNESCO World Heritage site). The BBVC eruption would have evolved similarly to the 2014-2015 Bárðarbunga-Holuhraun fissure eruption in Iceland, but with increased complexity due to its intraplate continental setting and feeder dyke interaction with aquifers and near-surface faults, resulting in greater level of phreatomagmatism and explosion depths potentially down to 320 m. This finding must be considered to improve future eruption scenario assessments in the NVP and builds new understanding of complex volcanic fissure eruption behaviour that can be applied to similar systems around the world. The online version contains supplementary material available at 10.1007/s00445-026-01967-9.

Many new techniques for ensuring traceable temperature measurements at the point of use are being developed and some are approaching maturity. The aim of this study is to examine the formalism associated with traceability to the SI kelvin for these practical techniques, as well as to identify areas of research which should be a priority. First, the status quo of thermodynamic temperature realization and dissemination is summarized. Then the state of the art of two main types of thermometry which can potentially provide in situ traceability is discussed. These are self-validating thermometers which make use of the phase change of materials, and practical primary thermometers, examples of which are given in order of decreasing commercial readiness: relative primary radiometry, acoustic gas thermometry (AGT), Johnson noise thermometry (JNT) and Doppler broadening thermometry (DBT). It is shown that relative primary thermometry is, in general, much more likely to become a day-to-day practical reality than absolute primary thermometry, and that this has a significant bearing on what the formalism might look like regarding metrological traceability and demonstrations of equivalence. This article is part of the Theo Murphy meeting issue 'The redefined kelvin: progress and prospects'.

The aim of the study was to create a Polish adaptation of the Highly Sensitive Person Scale (HSPS), assess its psychometric properties and conduct factor analysis in a group of adults. Five hundred two students of the Poznan University of Medical Sciences, aged 19-40 were studied, assessed by the 27-item HSPS, Beck Depression Inventory (BDI) and NEO-FFI Questionnaire. Exploratory and confirmatory factor analysis was performed in two subgroups (N = 250 and N = 252, respectively). The Polish version was accepted by the authors of the scale. Cronbach's α was 0.90 and the ICC interclass correlation coefficient was 0.95 for retest data. Exploratory factor analysis distinguished a three-factor model of the HSPS scale (EOE, LST and AES factors), and confirmatory analysis confirmed its better fit. The HSPS scale, EOE and LST showed a significant relationship with the BDI and "Neuroticism" and a negative relationship with "Extraversion", while the AES factor was strongly related to "Openness". Women scored higher on all HSPS subscales, HSPS total score and "Conscientiousness". The Polish version of the HSPS scale is characterized by good reliability, consistency and validity, and the results indicate a three-factor model. We recommend the use of the HSPS scale in Polish conditions by mental health professionals.

Our study aimed to unravel the unknown mechanisms behind the exceptional efficacy of Psilocybin (PSI) in treating treatment-resistant depression (TRD). Focusing on Wistar-Kyoto (WKY) rats with a TRD phenotype and Wistar (WIS) rats as a normative comparison, we investigated behavioral and neuroplasticity-related responses to PSI, striving to shed light on the distinctive features of its antidepressant effects. We set out to assess the behavioral impact of acute and prolonged PSI administration on WKY and WIS rats, employing Novel Object Recognition (NORT), Social Interaction (SI), and Forced Swimming Test (FST). Our secondary objectives involved exploring strain-specific alterations in neuroplasticity-related parameters, including brain-derived neurotrophic factor (BDNF) and activity-regulated cytoskeleton-associated protein (Arc). Conducting post-acute and extended assessments after a single PSI administration, we applied behavioral tests and biochemical analyses to measure serum BDNF levels and neuroplasticity-related parameters in the prefrontal cortex. Statistical analyses were deployed to discern significant differences between the rat strains and assess the impact of PSI on behavioral and biochemical outcomes. Our findings uncovered significant behavioral disparities between WKY and WIS rats, indicating passive behavior and social withdrawal in the former. PSI demonstrated pronounced pro-social and antidepressant effects in both strains, each with its distinctive temporal trajectory. Notably, we identified strain-specific variations in BDNF-related signaling and observed the modulation of Arc expression in WKY rats. Our study delineated mood-related behavioral nuances between WKY and WIS rat strains, underscoring the antidepressant and pro-social properties of PSI in both groups. The distinct temporal patterns of observed changes and the identified strain-specific neuroplasticity alterations provide valuable insights into the TRD phenotype and the mechanisms underpinning the efficacy of PSI.

This study presents an enhanced approach for estimating groundwater storage (GWS) dynamics using downscaled Gravity Recovery and Climate Experiment (GRACE) data combined with Global Land Data Assimilation System (GLDAS) outputs in the transboundary Bug River Basin. We applied three innovations to improve satellite-based GWS estimation. First, we applied the random forest (RF) algorithm to downscale GRACE terrestrial water storage (TWS) data to 0.1° × 0.1° resolution, using precipitation, evapotranspiration, runoff, and soil moisture as predictors. Second, we introduced a novel cumulative component to the GLDAS-based TWS change indicator, representing vadose-zone water equivalent, which depends on groundwater level (GWL) depth. This adaptation accounted for hydrodynamic conditions by extending the accumulation period with increasing GWL depth, effectively reducing phase shifts and temporal delays relative to the in-situ GWS observations common in prior studies. Third, satellite-based GWS estimates were calibrated using in-situ groundwater measurements combined with RF and kriging. The proposed approach significantly improved consistency between satellite-derived and in-situ GWS (correlation coefficients between 0.66 and 0.95), enhancing the reliability of groundwater monitoring. The GWS seasonal variability and amplitude were found to strongly depend on vadose zone properties and GWL depth. Despite an overall decline in total TWS, GWS in the Bug River Basin remained stable, reflecting system resilience to climatic fluctuations. Our methodology enhances groundwater monitoring and forecasting in transboundary catchments and enables the development of continuous changes in GWS in time and space, which is particularly important for regions with a sparse network of in-situ observations.

暂无摘要（点击查看详情）

Extended gamma-ray emission around isolated pulsars at TeV energies, also known as TeV halos, have been found around a handful of middle-aged pulsars. The halos are significantly more extended than their pulsar wind nebulae but much smaller than the particle diffusion length in the interstellar medium. The origin of TeV halos is unknown. Interpretations invoke either local effects related to the environment of a pulsar or generic particle transport behaviors. The latter scenario predicts that TeV halos would be a universal phenomena for all pulsars. We searched for extended gamma-ray emission around 36 isolated middle-aged pulsars identified by radio and gamma-ray facilities using 2321 days of data from the High-Altitude Water Cherenkov (HAWC) Observatory. Through a stacking analysis comparing TeV flux models against a background-only hypothesis, we identified TeV halolike emission at a significance level of 5.10σ. Our results imply that extended TeV gamma-ray halos may commonly exist around middle-aged pulsars. This reveals a previously unknown feature about pulsars and opens a new window to identify the pulsar population that is invisible to radio, x-ray, and GeV gamma-ray observations.

Maternal consumption of monosaccharides during pregnancy and lactation can program long-term metabolic and neurobehavioral outcomes in offspring. The melanocortin-4 receptor (MC4R) is a key regulator of metabolism and behavior. However, the impact of maternal monosaccharide diets on MC4R signaling within mesocorticolimbic regions remains unclear. In this study, we investigated the effects of maternal glucose (GLU) and fructose (FRU) diets on metabolic, molecular, and neurochemical outcomes in offspring. Adolescent and young adult male and female Wistar rat offspring, following maternal GLU and FRU exposure during pregnancy and lactation, underwent sucrose preference testing, intraperitoneal glucose tolerance tests, and serum lipid profiling. In addition, the gene expression of Mc4r, proopiomelanocortin (Pomc), agouti-related peptide (Agrp), and melanocortin-2 receptor accessory protein 2 (Mrap2) was quantified in the nucleus accumbens, prelimbic cortex, dorsal striatum, and basolateral amygdala, while the levels of MC4R protein were assessed in synaptosomal fractions from these brain regions. The maternal GLU diet reduced total calorie intake during lactation, while the FRU diet increased the dams’ caloric intake from sugar during both pregnancy and lactation. In the offspring, a maternal FRU diet increased sucrose consumption in young adult males and dysregulated glucose homeostasis in both adolescent and young adult males. Maternal monosaccharide diets also influenced serum lipid profiles and increased the body weights of their offspring. At the molecular level, region-, sex-, and age-specific changes in gene expression were observed, particularly the upregulation of Mc4r. Neurochemical analyses showed that maternal FRU diet increased synaptosomal MC4R levels in the mesocorticolimbic regions of young adult offspring. Principal component analysis revealed distinct clustering of metabolic and MC4R-related variables based on diet and sex, while regression analyses indicated significant diet-dependent correlations between MC4R levels and lipid parameters. These findings suggest that maternal monosaccharide diets induce persistent alterations in the metabolic profiles of offspring and MC4R signaling, potentially contributing to the development of programmed metabolic and behavioral outcomes. Not applicable. The online version contains supplementary material available at 10.1007/s43440-025-00785-8.

The properties of compatibilized blends of polyethylene (PE) and polypropylene (PP), having reduced macromolecular entanglements, were studied. The density of PP macromolecular entanglements was controlled by prior disentangling in solution. The polymer ratio in the blend was 4:1 or 1:4. An ethylene-octene copolymer was used as a compatibilizer. The melt blending process resulted in good dispersion of the minority component, with slightly larger inclusions when more disentangled PP was used. Rheological studies confirmed the achievement of different entanglement densities of PP macromolecules in the blends. The partial disentanglement did not affect the thermal stability of the blends. During the isothermal crystallization studies, faster growth of PP spherulites was observed in the blend with reduced entanglements, which also influenced the entire crystallization process. The recovery time of equilibrium entanglement was investigated and it turned out to be 45 min if the blend was annealed at 190 °C, which was shorter than in the analogous homopolymer. Studies of tensile properties showed that in blends with a majority share of polyethylene, the elongation at break increased with the disentanglement of the minority component, due to better bonding of the blend components and thus the reduction in microcavitation.