Observation of plaid-like spin splitting in a noncoplanar antiferromagnet.

Spatial, momentum and energy separation of electronic spins in condensed-matter systems guides the development of new devices in which spin-polarized current is generated and manipulated1-3. Recent attention on a set of previously overlooked symmetry operations in magnetic materials4 leads to the emergence of a new type of spin splitting, enabling giant and momentum-dependent spin polarization of energy bands on selected antiferromagnets5-10. Despite the ever-growing theoretical predictions, the direct spectroscopic proof of such spin splitting is still lacking. Here we provide solid spectroscopic and computational evidence for the existence of such materials. In the noncoplanar antiferromagnet manganese ditelluride (MnTe2), the in-plane components of spin are found to be antisymmetric about the high-symmetry planes of the Brillouin zone, comprising a plaid-like spin texture in the antiferromagnetic (AFM) ground state. Such an unconventional spin pattern, further found to diminish at the high-temperature paramagnetic state, originates from the intrinsic AFM order instead of spin-orbit coupling (SOC). Our finding demonstrates a new type of quadratic spin texture induced by time-reversal breaking, placing AFM spintronics on a firm basis and paving the way for studying exotic quantum phenomena in related materials.

Single-cell genomics revolutionizes plant development studies across scales.

Understanding the development of tissues, organs and entire organisms through the lens of single-cell genomics has revolutionized developmental biology. Although single-cell transcriptomics has been pioneered in animal systems, from an experimental perspective, plant development holds some distinct advantages: cells do not migrate in relation to one another, and new organ formation (of leaves, roots, flowers, etc.) continues post-embryonically from persistent stem cell populations known as meristems. For a time, plant studies lagged behind animal or cell culture-based, single-cell approaches, largely owing to the difficulty in dissociating plant cells from their rigid cell walls. Recent intensive development of single-cell and single-nucleus isolation techniques across plant species has opened up a wide range of experimental approaches. This has produced a rapidly expanding diversity of information across tissue types and species, concomitant with the creative development of methods. In this brief Spotlight, we highlight some of the technical developments and how they have led to profiling single-cell genomics in various plant organs. We also emphasize the contribution of single-cell genomics in revealing developmental trajectories among different cell types within plant organs. Furthermore, we present efforts toward comparative analysis of tissues and organs at a single-cell level. Single-cell genomics is beginning to generate comprehensive information relating to how plant organs emerge from stem cell populations.

A Lactic Acid Metabolism-Related Gene Signature for Predicting Clinical Outcome and Tumor Microenvironmental Status in Patients with Hepatocellular Carcinoma.

This study aims to build a prognostic model based on lactic acid metabolism-related genes (LMRGs) to predict survival outcomes and tumor microenvironment status of Hepatocellular carcinoma (HCC) patients. The model was used to calculate riskscores of clinical samples. Survival analysis and Cox regression analysis were conducted to verify the independence and reliability of the riskscore to determine its clinical significance in prognosis evaluation of HCC. Additionally, we conducted a comprehensive analysis of tumor mutation burden (TMB), immune cell infiltration, and gene set molecular function in the high- and low-risk groups. We obtained 134 LMRGs mainly involved in cellular calcium homeostasis and calcium signaling pathways. The LMRGs in the risk assessment model included PFKFB4, SLC16A3, ADRA2B, SLC22A1, QRFPR, and PROK1. This study discovered much shorter overall survival and median survival time of patients with higher riskscores when compared to those with lower riskscores. It was indicated that for independent prediction of patients' prognosis, the riskscore had a significant clinical value. A remarkable difference was also found regarding TMB between the two groups. Finally, cell experiments demonstrated that the knockout of PFKFB4 and SLC16A3 genes suppressed lactate. Our research demonstrated that the riskscore, established based on LMRGs, is a promising biomarker.

Ag-N-C single atom catalyst with resistance for Ag loss in acetylene hydrochlorination.

Ag-N-C catalyst was synthesized by the calcination process with AgNO3as precursors, active carbon as support, and melamine as an N source. Series of characterizations showed that Ag was transferred into AgCl during the active phase by HCl, and pyridinic structure in the support was bonded with Ag components. Then, Ag-N-C single atom catalyst (SAC) was obtained by washing Ag-N-C with acid, aberration-correction high-angle-annular-dark-field scanning transmission electron microscopy showed that Ag presented in single atoms form, and Ag coordinated with the nitrogen atom in the support. Ag loss rate for Ag-N-C SAC was only 0.09% after running 10 h in acetylene hydrochlorination process, which was much smaller than Ag-N-C (57%), indicating that the presence of the Ag-N bond could be inhibiting Ag species loss.

Deactivation and Regeneration of Nitrogen Doped Carbon Catalyst for Acetylene Hydrochlorination.

The poor stability of carbon materials doped with nitrogen limited their development in acetylene hydrochlorination. Therefore, investigating the deactivation reasons of carbon catalysts and researching regeneration methods became the research focus. Herein, carbon-nitrogen materials were synthesized by one-step pyrolysis, which using biomass materials with high nitrogen content, the synthesized material was used in an acetylene hydrochlorination reaction. The acetylene conversion rate of D-GH-800 catalyst was up to 99%, but the catalytic activity decreased by 30% after 60 h reaction. Thermogravimetric analysis results showed that the coke content was 5.87%, resulting in catalyst deactivation. Temperature-programmed desorption verified that the deactivation was due to the strong adsorption and difficult desorption of acetylene by the D-GH-800 catalyst, resulting in the accumulation of acetylene on the catalyst surface to form carbon polymers and leading to the pore blockage phenomenon. Furthermore, based on the catalyst deactivation by carbon accumulation, we proposed a new idea of regeneration by ZnCl2 activation to eliminate carbon deposition in the pores of the deactivated catalyst. As a result, the activity of D-GH-800 was recovered, and lifetime was also extended. Our strategy illustrated the mechanism of carbon deposition, and the recoverability of the catalyst has promising applications.

The Role of Noncoding RNA Antisense Transcript of the B-Cell Translocation Gene 3 Regulation of BTG3 in Pancreatic Ductal Adenocarcinoma Tumor Progression.

Background: Antisense transcript of the B-cell translocation gene 3 (ASBEL) is a highly conserved antisense non-coding RNA (ncRNA) and participates in a variety of biological processes. However, the ASBEL expression status in pancreatic ductal adenocarcinoma (PDAC) and its correlation with BTG3 expression and tumor cell progression were not completely clear. Objective: We conducted cell experiments and animal experiments to confirm that ASBEL plays a crucial role in the tumorigenesis of PDAC by targeting BTG3. Methods: ASBEL regulation in PDAC tumorigenesis was evaluated using Western blotting, quantitative polymerase chain reaction, Cell Counting Kit-8 assay, flow cytometry, and cell transfection. We also evaluated the expression of ASBEL and BTG3 in tumor tissues and cells using Western blotting and quantitative real-time polymerase chain reaction. Finally, we explored the role of ASBEL in tumor development by silencing or overexpressing ASBEL gene in AsPC-1 or CFPAC-1 cells, respectively, and evaluated the antitumor activity in vivo using an ASBEL antagonist. Results: Our study revealed the expression of ASBEL in all pancreatic cell lines. The expression level of ASBEL in tumor tissues was found to be higher than that of paracarcinomatous tissues. ASBEL suppresses expression of BTG3, enhances proliferation and suppresses apoptosis, and promotes migration and invasion in pancreatic cancer cell. Antagonist regulates the expression of ASBEL in AsPC-1, and suppresses tumor growth in xenograft mouse model. Conclusions: Our results indicate that ASBEL may play a tumor-promoting factor in PDAC by targeting BTG3 and could be as an important biomarker for PDAC treatment. (Curr Ther Res Clin Exp. 2023; 84:XXX-XXX).

VAP-RELATED SUPPRESSORS OF TOO MANY MOUTHS (VST) family proteins are regulators of root system architecture.

Root system architecture (RSA) is a key factor in the efficiency of nutrient capture and water uptake in plants. Understanding the genetic control of RSA will be useful in minimizing fertilizer and water usage in agricultural cropping systems. Using a hydroponic screen and a gel-based imaging system, we identified a rice (Oryza sativa) gene, VAP-RELATED SUPPRESSOR OF TOO MANY MOUTHS1 (OsVST1), which plays a key role in controlling RSA. This gene encodes a homolog of the VAP-RELATED SUPPRESSORS OF TOO MANY MOUTHS (VST) proteins in Arabidopsis (Arabidopsis thaliana), which promote signaling in stomata by mediating plasma membrane-endoplasmic reticulum contacts. OsVST1 mutants have shorter primary roots, decreased root meristem size, and a more compact RSA. We show that the Arabidopsis VST triple mutants have similar phenotypes, with reduced primary root growth and smaller root meristems. Expression of OsVST1 largely complements the short root length and reduced plant height in the Arabidopsis triple mutant, supporting conservation of function between rice and Arabidopsis VST proteins. In a field trial, mutations in OsVST1 did not adversely affect grain yield, suggesting that modulation of this gene could be used as a way to optimize RSA without an inherent yield penalty.

Growth dynamics of the Arabidopsis fruit is mediated by cell expansion.

Fruit have evolved a sophisticated tissue and cellular architecture to secure plant reproductive success. Postfertilization growth is perhaps the most dramatic event during fruit morphogenesis. Several studies have proposed that fertilized ovules and developing seeds initiate signaling cascades to coordinate and promote the growth of the accompanying fruit tissues. This dynamic process allows the fruit to conspicuously increase its size and acquire its final shape and means for seed dispersal. All these features are key for plant survival and crop yield. Despite its importance, we lack a high-resolution spatiotemporal map of how postfertilization fruit growth proceeds at the cellular level. In this study, we have combined live imaging, mutant backgrounds in which fertilization can be controlled, and computational modeling to monitor and predict postfertilization fruit growth in Arabidopsis We have uncovered that, unlike leaves, sepals, or roots, fruit do not exhibit a spatial separation of cell division and expansion domains; instead, there is a separation into temporal stages with fertilization as the trigger for transitioning to cell expansion, which drives postfertilization fruit growth. We quantified the coordination between fertilization and fruit growth by imaging no transmitting tract (ntt) mutants, in which fertilization fails in the bottom half of the fruit. By combining our experimental data with computational modeling, we delineated the mobility properties of the seed-derived signaling cascades promoting growth in the fruit. Our study provides the basis for generating a comprehensive understanding of the molecular and cellular mechanisms governing fruit growth and shape.

Density Functional Theory Study of Low-Dimensional (2D, 1D, 0D) Boron Nitride Nanomaterials Catalyzing Acetylene Acetate Reaction.

In this paper, density functional theory (DFT) was used to study the possibility of low-dimensional (2D, 1D, 0D) boron nitride nanomaterials to catalyze acetylene acetate reaction, and further explore the possible source of this catalytic activity. It is found that the catalytic activity of boron nitride nanomaterials for acetylene acetate reaction will change with the change of the geometric structure (dimension) and reaction site of the catalyst. From the geometric structure, the reaction components and the zero-dimensional BN catalyst can form chemical bonds and form complexes, while only physical adsorption occurs on the surface of the one-dimensional and two-dimensional BN catalysts. From the reaction site, the properties of different C sites on the B12N12NC-C2H2 complexes are different. Namely, a C atom connected with a B atom is more likely to have an electrophilic reaction with H+, and a C atom connected with an N atom is more likely to have a nucleophilic reaction with CH3COO-. Through the study of three kinds of BN nanomaterials with low dimensions, we found that the zero-dimensional B12N12 nanocage broke the inherent reaction inertia of BN materials and showed good catalytic activity in an acetylene acetate reaction, which is very likely to be a non-metallic catalyst for the acetylene gas-phase preparation of vinyl acetate.

Density Functional Theory Study on NiNx (x = 1, 2, 3, 4) Catalytic Hydrogenation of Acetylene.

In this study, using the application of density functional theory, the mechanism of graphene-NiNx (x = 1, 2, 3, 4) series non-noble metal catalysts in acetylene hydrogenation was examined under the B3LYP/6-31G** approach. With the DFT-D3 density functional dispersion correction, the effective core pseudopotential basis set of LANL2DZ was applied to metallic Ni atoms. The reaction energy barriers of NiNx catalysts are different from the co-adsorption structure during the catalytic hydrogenation of graphene-NiNx (x = 1, 2, 3, 4). The calculated results showed that the energy barrier and selectivity of graphene-NiN4 for ethylene production were 25.24 kcal/mol and 26.35 kcal/mol, respectively. The low energy barrier and high activity characteristics showed excellent catalytic performance of the catalyst. Therefore, graphene-NiN4 provides an idea for the direction of catalytic hydrogenation.

Interfacial Charge Transport in 1D TiO2 Based Photoelectrodes for Photoelectrochemical Water Splitting.

1D nanostructured photoelectrodes are promising for application as photoelectrochemical (PEC) devices for solar energy conversion into hydrogen (H2 ) owing to the optical, structural, and electronic advantages. Titanium dioxide (TiO2 ) is the most investigated candidate as a photoelectrode due to its good photostability, low production cost, and eco-friendliness. The obstacle for TiO2 's practical application is the inherent wide bandgap (UV-lights response), poor conductivity, and limited hole diffusion length. Here, a comprehensive review of the current research efforts toward the development of 1D TiO2 based photoelectrodes for heterogeneous PEC water splitting is provided along with a discussion of nanoarchitectures and energy band engineering influences on interfacial charge transfer and separation of 1D TiO2 composited with different dimensional photoactive materials. The key focus of this review is to understand the charge transfer processes at interfaces and the relationship between photogenerated charge separation and photoelectrochemical performance. It is anticipated that this review will afford enriched information on the rational designs of nanoarchitectures, doping, and heterojunction interfaces for 1D TiO2 based photoelectrodes to achieve highly efficient solar energy conversion.

Cobalt Chalcogenides/Cobalt Phosphides/Cobaltates with Hierarchical Nanostructures for Anode Materials of Lithium-Ion Batteries: Improving the Lithiation Environment.

Lithium-ion batteries (LIBs) are widely used in electric vehicles and portable electronic devices due to their high energy density, long cycle life, environmental friendliness, and negligible memory effect, though they also suffer from low power density, safety issues, and an aging effect. Cobalt chalcogenides/phosphides as promising anode materials have attracted intensive interests due to their high theoretical capacity based on the conversion mechanism. Cobaltates (XCo2 O4 , X = the other metal) have attracted attention because the X element can partially replace the high cost and toxic cobalt element. The serious volume variation during the cycling process has an impact, however, on the lithiation environment of above materials. Hierarchical construction can provide more active sites and shorten the diffusion pathways of Li ions as well as accommodating the volume expansion during lithiation processes. Herein, the research progress on the synthesis methods, structural characteristics, and electrochemical performances of cobalt chalcogenides/cobalt phosphides/cobaltates with hierarchical nanostructures for LIBs is presented. The concluding remarks highlight the research challenges and possible development directions of cobalt chalcogenides/cobalt phosphides/cobaltates with tailored hierarchical nanostructures for LIBs.

Surface and Interface Engineering: Molybdenum Carbide-Based Nanomaterials for Electrochemical Energy Conversion.

Molybdenum carbide (Mox C)-based nanomaterials have shown competitive performances for energy conversion applications based on their unique physicochemical properties. A large surface area and proper surface atomic configuration are essential to explore potentiality of Mox C in electrochemical applications. Although considerable efforts are made on the development of advanced Mox C-based catalysts for energy conversion with high efficiency and stability, some urgent issues, such as low electronic conductivity, low catalytic efficiency, and structural instability, have to be resolved in accordance with their application environments. Surface and interface engineering have shown bright prospects to construct highly efficient Mox C-based electrocatalysts for energy conversion including the hydrogen evolution reaction, oxygen evolution reaction, nitrogen reduction reaction, and carbon dioxide reduction reaction. In this Review, the recent progresses in terms of surface and interface engineering of Mox C-based electrocatalytic materials are summarized, including the increased number of active sites by decreasing the particle size or introducing porous or hierarchical structures and surface modification by introducing heteroatom(s), defects, carbon materials, and others electronic conductive species. Finally, the challenges and prospects for energy conversion on Mox C-based nanomaterials are discussed in terms of key performance parameters for the catalytic performance.

The prognostic value of intratumoral and peritumoral tumor-infiltrating FoxP3+Treg cells in of pancreatic adenocarcinoma: a meta-analysis.

BACKGROUND: Tumor-infiltrating lymphocytes (TILs) are major participants in the tumor microenvironment. The prognostic value of TILs in patients with pancreatic cancer is still controversial. METHODS: The aim of our meta-analysis was to determine the impact of FoxP3+Treg cells on the survival of pancreatic cancer patients. We searched for related studies in PubMed, EMBASE, Ovid, and Cochrane Library from the time the databases were established to Mar 30, 2017. We identified studies reporting the prognostic value of FoxP3+Treg cells in patients with pancreatic cancer. Overall survival (OS) and disease-free survival (DFS)/progression-free survival (PFS)/relapse-free survival (RFS) were investigated by pooling the data. The pooled hazard ratios (HRs) with 95% confidence intervals (95% CI) were used to evaluate the association between FoxP3+Treg cells and survival outcomes of pancreatic cancer patients. A total of 972 pancreatic cancer patients from 8 studies were included in our meta-analysis. RESULTS: High levels of infiltration with FoxP3+Treg cells were significantly associated with poor OS (HR=2.13; 95% CI 1.64-2.77; P<0.05) and poor DFS/PFS/RFS (HR=1.70; 95% CI 1.04 ~ 2.78; P< 0.05). Similar results were also observed in the peritumoral tissue; high levels of FoxP3+Treg cells were associated with poor OS (HR =2.1795% CI, CI 1.50-3.13). CONCLUSION: This meta-analysis indicated that high levels of intratumoral or peritumoral FoxP3+Treg cell infiltration could be recognized as a negative factor in the prognosis of pancreatic cancer.

Highly selective catalytic reduction of NOx by MnOx-CeO2-Al2O3 catalysts prepared by self-propagating high-temperature synthesis.

We first present preparation of MnOx-CeO2-Al2O3 catalysts with varying Mn contents through a self-propagating high-temperature synthesis (SHS) method, and studied the application of these catalysts to the selective catalytic reduction of NOx with NH3 (NH3-SCR). Using the catalyst with 18 wt.% Mn (18MnCe1Al2), 100% NO conversion was achieved at 200°C and a gas hourly space velocity of 15384hr-1, and the high-efficiency SCR temperature window, where NO conversion is greater than 90%, was widened to a temperature range of 150-300°C. 18MnCe1Al2 showed great resistance to SO2 (100 ppm) and H2O (5%) at 200°C. The catalysts were characterized using X-ray diffraction, X-ray photoelectron spectroscopy, Brunauer-Emmett-Teller (BET) analysis, scanning electron microscopy, Fourier transform infrared spectroscopy, and H2 temperature programmed reduction. The characterization results showed that the surface atomic concentration of Mn increased with increasing Mn content, which led to synergism between Mn and Ce and improved the activity in the SCR reaction. 18MnCe1Al2 has an extensive pore structure, with a BET surface area of approximately 135.4m2/g, a pore volume of approximately 0.16cm3/g, and an average pore diameter of approximately 4.6 nm. The SCR reaction on 18MnCe1Al2 mainly followed the Eley-Rideal mechanism. The performances of the MnOx-CeO2-Al2O3 catalysts were good, and because of the simplicity of the preparation process, the SHS method is applicable to their industrial-scale manufacture.

Self-organization underlies developmental robustness in plants.

Development is a self-organized process that builds on cells and their interactions. Cells are heterogeneous in gene expression, growth, and division; yet how development is robust despite such heterogeneity is a fascinating question. Here, we review recent progress on this topic, highlighting how developmental robustness is achieved through self-organization. We will first discuss sources of heterogeneity, including stochastic gene expression, heterogeneity in growth rate and direction, and heterogeneity in division rate and precision. We then discuss cellular mechanisms that buffer against such noise, including Paf1C- and miRNA-mediated denoising, spatiotemporal growth averaging and compensation, mechanisms to improve cell division precision, and coordination of growth rate and developmental timing between different parts of an organ. We also discuss cases where such heterogeneity is not buffered but utilized for development. Finally, we highlight potential directions for future studies of noise and developmental robustness.

Tradeoff between speed and robustness in primordium initiation mediated by auxin-CUC1 interaction.

Robustness is the reproducible development of a phenotype despite stochastic noise. It often involves tradeoffs with other performance metrics, but the mechanisms underlying such tradeoffs were largely unknown. An Arabidopsis flower robustly develops four sepals from four precisely positioned auxin maxima. The development related myb-like 1 (drmy1) mutant generates noise in auxin signaling that disrupts robustness in sepal initiation. Here, we find that increased expression of CUP-SHAPED COTYLEDON1 (CUC1), a boundary specification transcription factor, in drmy1 underlies this loss of robustness. CUC1 surrounds and amplifies stochastic auxin noise in drmy1 to form variably positioned auxin maxima and sepal primordia. Removing CUC1 from drmy1 provides time for noisy auxin signaling to resolve into four precisely positioned auxin maxima, restoring robust sepal initiation. However, removing CUC1 decreases the intensity of auxin maxima and slows down sepal initiation. Thus, CUC1 increases morphogenesis speed but impairs robustness against auxin noise. Further, using a computational model, we find that the observed phenotype can be explained by the effect of CUC1 in repolarizing PIN FORMED1 (PIN1), a polar auxin transporter. Lastly, our model predicts that reducing global growth rate improves developmental robustness, which we validate experimentally. Thus, our study illustrates a tradeoff between speed and robustness during development.

DRMY1 promotes robust morphogenesis in Arabidopsis by sustaining the translation of cytokinin-signaling inhibitor proteins.

Robustness is the invariant development of phenotype despite environmental changes and genetic perturbations. In the Arabidopsis flower bud, four sepals robustly initiate and grow to a constant size to enclose and protect the inner floral organs. We previously characterized the mutant development-related myb-like 1 (drmy1), where 3-5 sepals initiate variably and grow to different sizes, compromising their protective function. The molecular mechanism underlying this loss of robustness was unclear. Here, we show that drmy1 has reduced TARGET OF RAPAMYCIN (TOR) activity, ribosomal content, and translation. Translation reduction decreases the protein level of ARABIDOPSIS RESPONSE REGULATOR7 (ARR7) and ARABIDOPSIS HISTIDINE PHOSPHOTRANSFER PROTEIN 6 (AHP6), two cytokinin-signaling inhibitors that are normally rapidly produced before sepal initiation. The resultant upregulation of cytokinin signaling disrupts robust auxin patterning and sepal initiation. Our work shows that the homeostasis of translation, a ubiquitous cellular process, is crucial for the robust spatiotemporal patterning of organogenesis.

Observation of Spin Splitting in Room-Temperature Metallic Antiferromagnet CrSb.

Recently, unconventional antiferromagnets that enable the spin splitting (SS) of electronic states have been theoretically proposed and experimentally realized, where the magnetic sublattices containing moments pointing at different directions are connected by a novel set of symmetries. Such SS is substantial, k-dependent, and independent of the spin-orbit coupling (SOC) strength, making these magnets promising materials for antiferromagnetic spintronics. Here, combined with angle-resolved photoemission spectroscopy (ARPES) and density functional theory (DFT) calculations, a systematic study on CrSb, a metallic spin-split antiferromagnet candidate with Néel temperature TN = 703 K, is conducted. The data reveal the electronic structure of CrSb along both out-of-plane and in-plane momentum directions, rendering an anisotropic k-dependent SS that agrees well with the calculational results. The magnitude of such SS reaches up to at least 0.8 eV at non-high-symmetry momentum points, which is significantly higher than the largest known SOC-induced SS. This compound expands the choice of materials in the field of antiferromagnetic spintronics and is likely to stimulate subsequent investigations of high-efficiency spintronic devices that are functional at room temperature.