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There is a strong relationship between metazoan body size and extinction risk. However, the size selectivity and underlying mechanisms in foraminifera, a common marine protozoa, remain controversial. Here, we found that foraminifera exhibit size-dependent extinction selectivity, favoring larger groups (>7.4 log10 cubic micrometer) over smaller ones. Foraminifera showed significant size selectivity in the Guadalupian-Lopingian, Permian-Triassic, and Cretaceous-Paleogene extinctions where the proportion of large genera exceeded 50%. Conversely, in extinctions where the proportion of large genera was

Massive carbon dioxide (CO2) emissions are widely assumed to be the driver of the end-Permian mass extinction (EPME). However, the rate of and total CO2 released, and whether the source changes with time, remain poorly understood, leaving a key question surrounding the trigger for the EPME unanswered. Here, we assimilate reconstructions of atmospheric Pco2 and carbonate δ13C in an Earth system model to unravel the history of carbon emissions and sources across the EPME. We infer a transition from a CO2 source with a thermogenic carbon isotopic signature associated with a slower emission rate to a heavier, more mantle-dominated volcanic source with an increased rate of emissions. This implies that the CO2 degassing style changed as the Siberian Traps emplacement evolved, which is consistent with geochemical proxy records. Carbon cycle feedbacks from terrestrial ecosystem disturbances may have further amplified the warming and the severity of marine extinctions.

Electrochemical aptamer-based (EAB) sensors utilize the binding-induced conformational change of an electrode-attached, redox-reporter-modified aptamer to transduce target recognition into an easily measurable electrochemical output. Because this signal transduction mechanism is single-step and rapidly reversible, EAB sensors support high-frequency, real-time molecular measurements, and because it recapitulates the reagentless, conformation-linked signaling seen in vivo among naturally occurring receptors, EAB sensors are selective enough to work in the complex, time-varying environments found in the living body. The fabrication of EAB sensors, however, requires that their target-recognizing aptamer be modified such that (1) it undergoes the necessary binding-induced conformational change and (2) that the thermodynamics of this conformational switch are tuned to ensure that they reflect an acceptable trade-off between affinity and signal gain. That is, even if an as-selected aptamer achieves useful affinity and specificity, it may fail when adapted to the EAB platform because it lacks the binding-induced conformational change required to support EAB signaling. In this paper we reveal the spectroscopy-guided approaches we use to modify aptamers such that they support the necessary binding-induced conformational change. Specifically, using newly reported aptamers, we demonstrate the systematic design of EAB sensors achieving clinically and physiologically relevant specificity, limits of detection, and dynamic range against the targets methotrexate and tryptophan.

The Eocene was a typical greenhouse climate period in the history of the Earth, with a high global sea level and extensive carbonate deposits developed in Tethys. During the Eocene, a carbonate platform was deposited in the western Tarim Basin, which belongs to the easternmost Tethys. However, the details of this carbonate platform and its complications for paleoecology and paleoclimate are still unclear. This research focuses on the bivalve-bearing carbonates of the Kalataer Formation in the western Tarim Basin, and detailed analyses of microfacies, biostratigraphy, paleoecology, and sea-level change were carried out. The bivalves of the Kalataer Formation are dominated by the Ostrea (Turkostrea) strictiplicata, Ostrea (Turkostrea) cizancourti, Ostrea (Turkostrea) strictiplicata, Ostrea (Turkostrea) strictiplicata, and Sokolowia buhsii, and the age is middle Lutetian of the Eocene. The biota of the Kalataer Formation mainly lives in open shallow sea environments, with medium to low energy and rich nutrients and oxygen, representing a typical shallow marine ecosystem of the carbonate platform. Microfacies and paleoecology indicate a large marine transgression event occurred in the western Tarim Basin during the middle Eocene. [ABSTRACT FROM AUTHOR]

Currently, the knowledge of long noncoding RNA (lncRNA)‐encoded peptides is quite lacking in esophageal squamous cell carcinoma (ESCC). In this study, we simultaneously identified six lncRNA open reading frames (ORFs) with peptide‐coding abilities including lysine‐specific demethylase 4A antisense RNA 1 (KDM4A‐AS1) ORF by combining weighted gene co‐expression network analysis (WGCNA) for ESCC clinical samples, ribosome footprints, ORF prediction, mass spectrometry (MS) identification, and western blotting. KDM4A‐AS1 ORF‐encoded peptide reduced ESCC cell viability and migratory ability. Co‐immunoprecipitation and MS analysis revealed that KDM4A‐AS1‐encoded peptide specifically bound with 103 proteins in ESCC cells, and enrichment analysis suggested that peptide‐bound proteins were related to fatty acid metabolism and redox process. Cell and molecular experiments demonstrated that KDM4A‐AS1‐encoded peptide inhibited stearoyl‐CoA desaturase and fatty acid synthase expression, increased reactive oxygen species level, and reduced mitochondrial membrane potential in ESCC cells. In summary, multiple lncRNAs with translation potential were simultaneously identified by combining multiple approaches in ESCC, providing novel identification strategies for lncRNA‐encoded peptides. Moreover, lncRNA KDM4A‐AS1‐encoded peptide weakened ESCC cell viability and migratory capacity and functioned in fatty acid metabolism and redox process. [ABSTRACT FROM AUTHOR]

Energy level interaction and electron concentration are crucial aspects that affect the response performance of quantum cascade detectors (QCDs). In this work, two different-structured array QCDs are prepared, and the detectivity reaches 109 cm·Hz1/2/W at room temperature. The overlap integral (OI) and oscillator strength (OS) between different energy levels under a series of applied biases are fitted and reveal the influence of energy level interaction on the response performance. The redistribution of electrons in the cascade structure at room temperatures is established. The coupled doped-well structure shows a higher electron concentration at room temperature, which represents a high absorption efficiency in the active region. Even better responsivity and detectivity are exhibited in the coupled doped-well QCD. These results offer a novel strategy to understand the mechanisms that affect response performance and expand the application range of QCDs for long-wave infrared (LWIR) detection. [ABSTRACT FROM AUTHOR]