Chiral superconductivity in heavy-fermion metal UTe2.

Spin-triplet superconductors are condensates of electron pairs with spin 1 and an odd-parity wavefunction1. An interesting manifestation of triplet pairing is the chiral p-wave state, which is topologically non-trivial and provides a natural platform for realizing Majorana edge modes2,3. However, triplet pairing is rare in solid-state systems and has not been unambiguously identified in any bulk compound so far. Given that pairing is usually mediated by ferromagnetic spin fluctuations, uranium-based heavy-fermion systems containing f-electron elements, which can harbour both strong correlations and magnetism, are considered ideal candidates for realizing spin-triplet superconductivity4. Here we present scanning tunnelling microscopy studies of the recently discovered heavy-fermion superconductor UTe2, which has a superconducting transition temperature of 1.6 kelvin5. We find signatures of coexisting Kondo effect and superconductivity that show competing spatial modulations within one unit cell. Scanning tunnelling spectroscopy at step edges reveals signatures of chiral in-gap states, which have been predicted to exist at the boundaries of topological superconductors. Combined with existing data that indicate triplet pairing in UTe2, the presence of chiral states suggests that UTe2 is a strong candidate for chiral-triplet topological superconductivity.

Dynamic profiling and functional interpretation of histone lysine crotonylation and lactylation during neural development.

Metabolites such as crotonyl-CoA and lactyl-CoA influence gene expression by covalently modifying histones, known as histone lysine crotonylation (Kcr) and lysine lactylation (Kla). However, the existence patterns, dynamic changes, biological functions and associations of these modifications with histone lysine acetylation and gene expression during mammalian development remain largely unknown. Here, we find that histone Kcr and Kla are widely distributed in the brain and undergo global changes during neural development. By profiling the genome-wide dynamics of H3K9ac, H3K9cr and H3K18la in combination with ATAC and RNA sequencing, we reveal that these marks are tightly correlated with chromatin state and gene expression, and extensively involved in transcriptome remodeling to promote cell-fate transitions in the developing telencephalon. Importantly, we demonstrate that global Kcr and Kla levels are not the consequence of transcription and identify the histone deacetylases (HDACs) 1-3 as novel 'erasers' of H3K18la. Using P19 cells as an induced neural differentiation system, we find that HDAC1-3 inhibition by MS-275 pre-activates neuronal transcriptional programs by stimulating multiple histone lysine acylations simultaneously. These findings suggest that histone Kcr and Kla play crucial roles in the epigenetic regulation of neural development.

Emerging concepts of migrasome: An up-and-coming organelle from biology to the clinic.

Since the migrasome concept was first proposed in 2015, extensive research has been conducted on these novel organelles, which grow on retracted fibers at the posterior end of migrating cells. Recently, molecular markers, biological functions, and clinical values based on the initial formation mechanism of migrasomes have emerged. Additionally, researchers are recognizing the significant role that migrasomes play in the pathological and diagnostic processes of clinical diseases. In this review, we summarize recent advances in the biology and clinical application of migrasomes and provide a comprehensive view of the prospective challenges surrounding their clinical application.

Vitamin D promotes the folate transport and metabolism in zebrafish (Danio rerio).

Vitamin D (VD) is a fat-soluble sterol that possesses a wide range of physiological functions. The present study aimed to evaluate the effects of VD on folate metabolism in zebrafish and further investigated the underlying mechanism. Wild-type (WT) zebrafish were fed with a diet containing 0 IU/kg VD3 or 800 IU/kg VD3 for 3 wk. Meanwhile, cyp2r1 mutant zebrafish with impaired VD metabolism was used as another model of VD deficiency. Our results showed that VD deficiency in zebrafish suppressed the gene expression of folate transporters, including reduced folate carrier (RFC) and proton-coupled folate transporter (PCFT) in the intestine. Moreover, VD influenced the gene expression of several enzymes related to cellular folate metabolism in the intestine and liver of zebrafish. Importantly, VD-deficient zebrafish contained a remarkably lower level of folate content in the liver. Notably, VD was incapable of altering folate metabolism in zebrafish when gut microbiota was depleted by antibiotic treatment. Further studies proved that gut commensals from VD-deficient fish displayed a lower capacity to produce folate than those from WT fish. Our study revealed the potential correlation between VD and folate metabolism in zebrafish, and gut microbiota played a key role in VD-regulated folate metabolism in zebrafish.NEW & NOTEWORTHY Our study has identified that VD influences intestinal uptake and transport of folate in zebrafish while also altering hepatic folate metabolism and storage. Interestingly, the regulatory effects of VD on folate transport and metabolism diminished after the gut flora was interrupted by antibiotic treatment, suggesting that the regulatory effects of VD on folate metabolism in zebrafish are most likely dependent on the intestinal flora.

Effects of lianas on forest biogeochemistry during their lives and afterlives.

Climate change and other anthropogenic disturbances are increasing liana abundance and biomass in many tropical and subtropical forests. While the effects of living lianas on species diversity, ecosystem carbon, and nutrient dynamics are receiving increasing attention, the role of dead lianas in forest ecosystems has been little studied and is poorly understood. Trees and lianas coexist as the major woody components of forests worldwide, but they have very different ecological strategies, with lianas relying on trees for mechanical support. Consequently, trees and lianas have evolved highly divergent stem, leaf, and root traits. Here we show that this trait divergence is likely to persist after death, into the afterlives of these organs, leading to divergent effects on forest biogeochemistry. We introduce a conceptual framework combining horizontal, vertical, and time dimensions for the effects of liana proliferation and liana tissue decomposition on ecosystem carbon and nutrient cycling. We propose a series of empirical studies comparing traits between lianas and trees to answer questions concerning the influence of trait afterlives on the decomposability of liana and tree organs. Such studies will increase our understanding of the contribution of lianas to terrestrial biogeochemical cycling, and help predict the effects of their increasing abundance.

Linkages among stem xylem transport, biomechanics, and storage in lianas and trees across three contrasting environments.

PREMISE: Stem xylem transports water and nutrients, mechanically supports aboveground tissues, and stores water and nonstructural carbohydrates. These three functions are associated with three types of cells-vessel, fiber, and parenchyma, respectively. METHODS: We measured stem theoretical hydraulic conductivity (Kt), modulus of elasticity (MOE), tissue water content, starch, soluble sugars, cellulose, and xylem anatomical traits in 15 liana and 16 tree species across three contrasting sites in Southwest China. RESULTS: Lianas had higher hydraulic efficiency and tissue water content, but lower MOE and cellulose than trees. Storage traits (starch and soluble sugars) did not significantly differ between lianas and trees, and trait variation was explained mainly by site, highlighting how environment shapes plant storage strategies. Kt was significantly positively correlated with vessel diameter and vessel area fraction in lianas and all species combined. The MOE was significantly positively correlated with fiber area fraction, wood density, and cellulose in lianas and across all species. The tissue water content was significantly associated with parenchyma area fraction in lianas. Support function was strongly linked with transport and storage functions in lianas. In trees, transport and support functions were not correlated, while storage function was tightly linked with transport and support functions. CONCLUSIONS: These findings enhance our understanding of the relationship between stem xylem structure and function in lianas and trees, providing valuable insights into how plants adapt to environmental changes and the distinct ecological strategies employed by lianas and by trees to balance the demands of hydraulic transport, mechanical support, and storage.

Exosomal mRNA in plasma serves as a predictive marker for microvascular invasion in hepatocellular carcinoma.

BACKGROUND AND AIM: There is a pressing need for non-invasive preoperative prediction of microvascular invasion (MVI) in hepatocellular carcinoma (HCC). This study investigates the potential of exosome-derived mRNA in plasma as a biomarker for diagnosing MVI. METHODS: Patients with suspected HCC undergoing hepatectomy were prospectively recruited for preoperative peripheral blood collection. Exosomal RNA profiling was conducted using RNA sequencing in the discovery cohort, followed by differential expression analysis to identify candidate targets. We employed multiplexed droplet digital PCR technology to efficiently validate them in a larger sample size cohort. RESULTS: A total of 131 HCC patients were ultimately enrolled, with 37 in the discovery cohort and 94 in the validation cohort. In the validation cohort, the expression levels of RSAD2, PRPSAP1, and HOXA2 were slightly elevated while CHMP4A showed a slight decrease in patients with MVI compared with those without MVI. These trends were consistent with the findings in the discovery cohort, although they did not reach statistical significance (P > 0.05). Notably, the expression level of exosomal PRPSAP1 in plasma was significantly higher in patients with more than 5 MVI than in those without MVI (0.147 vs 0.070, P = 0.035). CONCLUSION: This study unveils the potential of exosome-derived PRPSAP1 in plasma as a promising indicator for predicting MVI status preoperatively.

You are what you eat: nutrient and water relations between mistletoes and hosts.

Mistletoes play important roles in biogeochemical cycles. Although many studies have compared nutrient concentrations between mistletoes and their hosts, no general patterns have been found and the nutrient uptake mechanisms in mistletoes have not been fully resolved. To address the water and nutrient relations in mistletoes compared with their hosts, we measured 11 nutrient elements, two isotope ratios and two leaf morphological traits for 11 mistletoe and 104 host species from four sites across a large environmental gradient in southwest China. Mistletoes had significantly higher phosphorus, potassium, and boron concentrations, nitrogen isotope ratio, and lower carbon isotope ratio (δ13 C) indicative of lower water-use efficiency than hosts, but other elements were similar to those in hosts. Sites explained most of the variation in the multidimensional trait space. With increasing host nitrogen concentration, both mistletoe δ13 C and the difference between mistletoe and host δ13 C increased, providing evidence to support the 'nitrogen parasitism hypothesis'. Host nutrient concentrations were the best predictors for that of the mistletoe nutrient elements in most cases. Our results highlight the important roles of environmental conditions and host nutrient status in determining mistletoe nutrient pools, which together explain their trophic interactions with hosts in subtropical and tropical ecosystems.

A critical thermal transition driving spring phenology of Northern Hemisphere conifers.

Despite growing interest in predicting plant phenological shifts, advanced spring phenology by global climate change remains debated. Evidence documenting either small or large advancement of spring phenology to rising temperature over the spatio-temporal scales implies a potential existence of a thermal threshold in the responses of forests to global warming. We collected a unique data set of xylem cell-wall-thickening onset dates in 20 coniferous species covering a broad mean annual temperature (MAT) gradient (-3.05 to 22.9°C) across the Northern Hemisphere (latitudes 23°-66° N). Along the MAT gradient, we identified a threshold temperature (using segmented regression) of 4.9 ± 1.1°C, above which the response of xylem phenology to rising temperatures significantly decline. This threshold separates the Northern Hemisphere conifers into cold and warm thermal niches, with MAT and spring forcing being the primary drivers for the onset dates (estimated by linear and Bayesian mixed-effect models), respectively. The identified thermal threshold should be integrated into the Earth-System-Models for a better understanding of spring phenology in response to global warming and an improved prediction of global climate-carbon feedbacks.

Sunlight Induced and Alternative Sc(OTf)3 Catalyzed Remote C-H Halogenation of Indoles.

A mild and catalyst-free sunlight induced protocol for the remote meta bromination of electron-deficient indoles is described for the first time. Herein, N-bromosaccharin is activated by sunlight irradiation. Alternately, a synergistic activation model (Sc(OTf)3 /HFIP) has also been developed for the activation of haloniums, complementary to the light induced strategy. In addition, the cascade C6-H bromination and benzylic C-H oxidation under photocatalytic conditions was also discussed. High regio-and chem-selectivity, mild reaction conditions, and scalability demonstrate great potential of the developed methods in practical applications and further functionalization.