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Redesigning algorithms to intervene on social norm misperceptions during a national election
Brazil’s environmental governance at risk
Microbial engraftment and immune regulation during fecal microbiota transplantation and immune checkpoint inhibitor therapy
Total phenolics, flavonoids and antioxidant activity in thirty litchi genotypes of Eastern India
Genome in motion: Mapping the nucleus in health
Few-femtosecond photoelectron spectroscopy reveals fundamental photodynamics of the carbon-carbon double bond in ethylene
Abstract Conjugated π -systems, often composed of carbon-carbon double bonds as key structural units, are among the most important organic chromophores and serve as prototypical systems for studying π π * excitation. Their ultrafast excited-state dynamics govern the outcomes of fundamental photochemical processes, including vision, photoisomerization, photosynthesis, and solar energy conversion. Here, we investigate the ultrafast dynamics of the simplest isolated C=C chromophore, ethylene, and its per-deuterated isotopologue using broadly tunable sub-4 femtosecond pulses in the 150-200 nm range combined with time-resolved photoelectron spectroscopy. Supported by advanced quantum dynamics calculations, our results reveal the important role of the 1 B 3 g ( σ π * ) state, which is strongly coupled through torsional motion to the optically populated 1 B 1 u ( π π * ) state. These findings establish a revised framework for understanding and controlling photochemical reaction in conjugated molecular systems.
Multi-layer collaborative control method for user-side resources based on deep deterministic policy gradient algorithm
The global biogeography of passerine songs
Although bird songs are classic models for understanding the evolution of vocal communication, their global diversity has long made the development of a unifying framework challenging. By analyzing the acoustic architecture of songs from more than 3000 passerine species worldwide, we show that this acoustic space can be structured around eight elemental motifs. The differential use of these motifs is driven by a combination of species’ biological traits (social organization, morphology, and mating system) and the physics of sound propagation. In tropical rainforests, environmental filtering for transmission efficiency favors structurally simple motifs, such as flat whistles. Conversely, in temperate regions, where high population densities facilitate close-range communication and short breeding seasons intensify sexual selection, the balance shifts toward complex, information-rich motifs, such as ultrafast trills, despite their susceptibility to acoustic degradation. Ultimately, the global geography of birdsong reflects a spatially varying equilibrium between physical environmental constraints and the biological drive for complex communication.
Mechanisms of MCM2–7 helicase activation and initial DNA melting at near base-pair resolution
Abstract During eukaryotic DNA replication initiation, inactive MCM2–7 double-hexamers assembled at replication origins must be converted into two active CMG helicases, yet how this transition is coupled to origin DNA unwinding in vivo remains unclear. Here, we identify a DNA-bound intermediate with an extended genomic footprint that forms during helicase activation. Genome-wide mapping of initial strand separation reveals that DNA unwinding initiates near the N-terminal interface of opposing MCM2–7 hexamers. At these sites, the origin DNA exhibits a conserved AT-rich/GC-rich/AT-rich sequence architecture centred under the helicase complex, which is associated with an elevated DNA melting probability. We further show that restricting hexamer splitting delays release of the Cdc45-loading factor Sld3, demonstrating that mechanical transitions during helicase activation are tightly coupled to complex disassembly. Finally, we provide in vivo evidence that single-stranded DNA is ejected through a specialised DNA exit gate at the Mcm2/5 interface during helicase activation, which is dispensable for ongoing DNA synthesis. Together, these findings establish a mechanistic framework for how replication origins are remodelled to initiate DNA replication and reveal key intermediates and DNA transactions during helicase activation.
GridTradeRL: a multi-agent deep reinforcement learning framework for decentralized peer-to-peer energy trading in smart grid prosumer networks
Late-stage functionalization with strain-release warheads enables tunable covalent inhibition
Covalent inhibition continues to gain momentum as a strategy for selective protein modulation in both therapeutic and chemical biology contexts. Covalent reactive groups (CRGs) typically engage nucleophilic residues such as cysteine, resulting in targeted protein inactivation. However, common electrophiles such as acrylamides often suffer from nonselective reactivity, leading to off-target effects and toxicity. To overcome these limitations, we developed a modular sulfur(IV) reagent platform for the mild, late-stage installation of sulfonyl- and sulfonimidoyl-bicyclobutane motifs with complete cysteine selectivity. This methodology enables access to diverse sulfur(VI) CRGs with tunable strain-release reactivity. Incorporation into US Food and Drug Administration–approved covalent inhibitors demonstrated effective bioisosteric replacement of acrylamides and the potential of strain-release CRGs for selective protein targeting. Preclinical studies in mice have validated this approach, highlighting its promise for next-generation covalent drug design.
Electronically coupled Co single atoms with Co-Pd alloy catalyst for high-performance rechargeable hydrazine-assisted Zn−Air batteries
Association of fluid balance trajectories with multi-timepoint prognosis in heart failure: a group-based trajectory model analysis
Crush-resistant air sacs allow insect larvae to exploit aquatic habitats at extreme depth
The absence of aquatic insects from pelagic marine habitats has been attributed to their air-filled tracheal respiratory system, which could implode at depth while undertaking diel vertical migrations to escape predatory fish. However, we found that the aquatic larvae of the lake fly Chaoborus edulis in Lake Malawi have modified their tracheal system into reinforced buoyancy-regulating air-filled sacs, allowing them to escape predatory fish by undertaking these migrations well over 200 meters deep into the lake’s anoxic hypolimnion during the day. The crush depth of their air sacs increases with each instar, with final instars resisting implosion at depths greater than half a kilometer. Contrary to expectations, these insects adapt to the extreme hydrostatic pressures of deep-water habitats, allowing them to coexist with pelagic fish.
Real-time photoactivated SRS imaging enables spatiotemporally controlled nitroxyl release and therapeutic guidance in vivo
Valorization of mahogany sawdust waste for dyeing of cotton knitted fabrics using aloe vera and banana sap bio-mordants
Abstract Growing environmental concerns and the need to reduce dependence on synthetic dyes have intensified the search for sustainable colorant sources and bio-based mordanting systems derived from renewable resources. In this study, mahogany sawdust, a wood industry by-product, was used as a natural dye source for cotton knitted fabric coloration. Aloe vera, banana sap, and their combination served as bio-mordants. Pre-mordanting was performed at 100 °C for 60 min, followed by 24 h of conditioning. The dye was extracted by heating a mahogany sawdust-water mixture at 100 °C for 1 h. The UV–Visible spectrum of the extract showed a maximum absorption at 275 nm, consistent with the absorption characteristics of flavonoid-related chromophoric compounds. FTIR spectra revealed intensified characteristic peaks in the combined bio-mordant sample, indicating improved intermolecular interaction and dye absorption behavior within the dye–fiber system. The highest color strength value of 7.1 was obtained with the aloe vera and banana sap combination, compared to 4.1 for the unmordanted fabric. Washing fastness improved from 2–3 in the control to 3–4 in mordanted samples, while wet rubbing fastness increased from 2–3 to 3–4, and light fastness reached a rating of 3 in the combined treatment. Comparatively lower weight-loss behavior during washing-based mechanical treatment was observed in bio-mordanted fabrics. Saliva fastness ratings of 3–4 for color change and 4–5 for staining demonstrated acceptable color resistance under saliva exposure conditions. The combined bio-mordant treatment demonstrates improved dye absorption behavior and durability, supporting potential application of mahogany sawdust-based coloration systems in sustainable cotton dyeing.
A fatal reaction
A cutting-edge gene-editing trial in China went disastrously wrong. A family wants accountability