Molecular Dynamics Insights into Mechanical Stability, Elastic Properties, and Fracture Behavior of PHOTH-Graphene.

PHOTH-graphene is a newly predicted 2D carbon material with a low-energy structure. However, its mechanical stability and fracture properties are still elusive. The mechanical stability, elastic, and fracture properties of PHOTH-graphene were investigated using classical molecular dynamics (MD) simulations equipped with REBO potential in this study. The influence of orientation and temperature on mechanical properties was evaluated. Specifically, the Young's modulus, toughness, and ultimate stress and strain varied by -26.14%, 36.46%, 29.04%, and 25.12%, respectively, when comparing the armchair direction to the zigzag direction. The percentage reduction in ultimate stress, ultimate strain, and toughness of the material in both directions after a temperature increase of 1000 K (from 200 K to 1200 K) ranged from 56.69% to 91.80%, and the Young's modulus was reduced by 13.63% and 7.25% in both directions, respectively, with Young's modulus showing lower sensitivity. Defects usually weaken the material's strength, but adding random point defects in the range of 3% to 5% significantly increases the ultimate strain of the material. Furthermore, hydrogen atom adsorption induces crack expansion to occur earlier, and the crack tip without hydrogen atom adsorption just began to expand when the strain was 0.135, while the crack tip with hydrogen atom adsorption had already undergone significant expansion. This study provides a reference for the possible future practical application of PHOTH-graphene in terms of mechanical properties and fracture failure.

Two-dimensional nanomaterials based on rare earth elements for biomedical applications.

As a kind of star materials, two-dimensional (2D) nanomaterials have attracted tremendous attention for their unique structures, excellent performance and wide applications. In recent years, layered rare earth-based or doped nanomaterials have become a new important member of the 2D nanomaterial family and have attracted significant interest, especially layered rare earth hydroxides (LREHs) and layered rare earth-doped perovskites with anion-exchangeability and exfoliative properties. In this review, we systematically summarize the synthesis, exfoliation, fabrication and biomedical applications of 2D rare earth nanomaterials. Upon exfoliation, the LREHs and layered rare earth-doped perovskites can be dimensionally reduced to ultrathin nanosheets which feature high anisotropy and flexibility. Subsequent fabrication, especially superlattice assembly, enables rare earth nanomaterials with diverse compositions and structures, which further optimizes or even creates new properties and thus expands the application fields. The latest progress in biomedical applications of the 2D rare earth-based or doped nanomaterials and composites is also reviewed in detail, especially drug delivery and magnetic resonance imaging (MRI). Moreover, at the end of this review, we provide an outlook on the opportunities and challenges of the 2D rare earth-based or doped nanomaterials. We believe this review will promote increasing interest in 2D rare earth materials and provide more insight into the artificial design of other nanomaterials based on rare earth elements for functional applications.

Gold-catalyzed highly enantioselective cycloadditions of 1,6-enynes and 1,6-diynes assisted by remote hydrogen bonding interaction.

Gold(I)-catalyzed highly enantioselective [4 + 2] cycloadditions of 1,6-enynes were achieved by utilizing chiral bifunctional P,N ligand. A wide range of 1,6-enynes were converted to enantioenriched 5-6-6-fused tricyclic compounds under mild reaction condition (up to 99% ee). This chiral gold(I) complex was also employed in the first desymmetric cycloadditions of 1,6-diynes bearing single ester group at the tether (up to 93% ee), where 5-exo-dig pathway predominates over 6-endo-dig pathway. DFT calculations and control experiments were performed to rationalize the origin of precise stereocontrol. It implies that hydrogen bonding interaction between the ester group of substrates and the secondary amine of the chiral P,N ligands plays a pivotal role in the control of enantioselectivity. The utilities of the current reaction were demonstrated by scale-up experiment and derivatizations.

Design and Synthesis of Sulfur-Containing Tetradentate Ligands for Ir-Catalyzed Asymmetric Hydrogenation of Ketones.

Developing highly active and enantioselective ligands for the asymmetric hydrogenation of ketones has consistently attracted significant attention from scientists. A series of novel tetradentate sulfur-containing ligands, termed as f-thiophamidol, were successfully designed and synthesized which exhibited excellent performance in the asymmetric hydrogenation of simple ketones (up to 99% yield, 99% ee) and α-substituted ß-keto sulfonamides (up to 99% yield, 99% ee, 99:1 dr). The subsequent successful gram-scale experiments with high TON demonstrated the immense potential application value of this system in synthesizing drug molecules.

A nomogram incorporating Psoas muscle index for predicting tumor recurrence after liver transplantation: A retrospective study in an Eastern Asian population.

Background and aims: Tumor recurrence significantly affects the prognostic outcomes for liver cancer patients following liver transplantation. However, existing predictive models often neglect the inclusion of body composition indicators. Hence, this research aimed to investigate the significance of the psoas muscle index (PMI) in evaluating the post-transplant prognosis of liver cancer. Methods: A retrospective analysis was conducted on liver cancer patients who underwent liver transplantation surgery. Imaging analysis was performed using CT data to calculate PMI based on the left and right psoas muscle areas. Subsequently, the patients were categorized into PMI-Low and PMI-High groups using the established cut-off values. Univariate and multivariate analyses were performed using Cox proportional hazards regression to assess the correlation between PMI and clinical outcomes, and a nomogram was constructed accordingly. Results: Among the 225 patients included in the analysis, the PMI-High group exhibited significantly improved overall survival (P < 0.001) and disease-free survival (DFS, P < 0.001) rates compared to the PMI-Low group. PMI exhibited a positive correlation with body mass index (R = 0.25, P < 0.001), but no significant correlations were observed. In the multivariate analysis, PMI (HR = 4.596, P < 0.001), MELD score (HR = 1.591, P = 0.038), and Hangzhou criteria (HR = 2.557, P < 0.001) emerged as significant predictors of DFS. The constructed nomogram, incorporating these predictors, demonstrated outstanding predictive performance. Decision curve analysis revealed the superiority of the nomogram over conventional methods. Conclusions: PMI serves as a valuable prognostic factor for tumor recurrence in liver cancer patients after liver transplantation. The established nomogram is pivotal in delivering personalized predictions of DFS.

Peteryoungia algae sp. nov. isolated from seaweeds of Gouqi Island, China, and its unique genetic features among Peteryoungia strains.

A Gram-stain-negative, light khaki, strictly aerobic, rod-shaped, motile via multiple flagella, and catalase- and oxidase-positive bacterium, designated as SSM4.3T, was isolated from the seaweed of Gouqi Island in the East China Sea. The novel isolate grows at 0-5.0% NaCl concentrations (w/v) (optimum 1%), pH 5.0-9.0 (optimum pH 7.0), and 15-37 °C (optimum 30 °C). The 16S rRNA gene sequences-based phylogeny indicates that the novel marine isolate belongs to the family Rhizobiaceae and that it shared the greatest sequence similarity (98.9%) with Peteryoungia rhizophila CGMCC 1.15691T. This classification was also supported by phylogenetic analysis using core genes. The predominant fatty acids (≥ 10%) of the strain were identified as C18:1 ω7c/C18:1 ω6c. Q-10 was identified as the major isoprenoid quinone, with trace levels of Q-9 present. The major polar lipids were identified as diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylglycerol. The complete genome size of strain SSM4.3T is 4.39 Mb with a DNA G+C content of 61.3%. The average nucleotide identity, digital DNA-DNA hybridization, and average amino acid identity values between the genomes of strain SSM4.3T and its closely related representatives were 74.80-86.93%, 20.00-32.30%, and 70.30-91.52%, respectively. Phylogenetic analysis, grounded on the core genes, reveals the evolutionary relationship between SSM4.3T and other Peteryoungia strains. Pan-genomics analysis of 8 previously classified Peteryoungia species and SSM4.3T revealed their unique genetic features and functions. Overall, strain SSM4.3T was considered to be a new species of the Peteryoungia genus; the name Peteryoungia algae sp. nov. has been proposed, with type strain SSM4.3T (= LMG 32561 = MCCC 1K07170).

Highly efficient synthesis of enantioenriched vicinal halohydrins via Ir-catalyzed asymmetric hydrogenation using dynamic kinetic resolution.

A novel synthetic route was developed for the construction of chiral cis-vicinal halohydrins derivatives through Ir/f-phamidol-catalysed asymmetric hydrogenation of corresponding α-halogenated ketones with high yields (up to 99% yield), excellent diastereoselectivities (>20 : 1 dr), enantioselectivities (up to 99% ee), and high substrate catalyst ratio (S/C = 1000).

Dynamic Kinetic Resolution of ß-Cyano α-Ketoesters via Asymmetric Transfer Hydrogenation.

An efficient rhodium-catalyzed asymmetric transfer hydrogenation of ß-cyano α-ketoesters via dynamic kinetic resolution has been developed. Despite the challenge posed by multiple functional groups, the reaction proceeded smoothly under mild conditions, generating versatile synthons with two adjacent stereocenters in high yields with excellent enantio- and diastereoselectivities. Furthermore, the power of this strategy is highlighted by the scale-up reaction and the follow-up synthesis of cytoxazone and paclitaxel intermediates.

Modeling of Material Removal Rate for the Fixed-Abrasive Double-Sided Planetary Grinding of a Sapphire Substrate.

Double-sided planetary grinding (DSPG) with a fixed abrasive is widely used in sapphire substrate processing. Compared with conventional free abrasive grinding, it has the advantages of high precision, high efficiency, and environmental protection. In this study, we propose a material removal rate (MRR) model specific to the fixed-abrasive DSPG process for sapphire substrates, grounded in the trajectory length of abrasive particles. In this paper, the material removal rate model is obtained after focusing on the theoretical analysis of the effective number of abrasive grains, the indentation depth of a single abrasive grain, the length of the abrasive grain trajectory, and the groove repetition rate. To validate this model, experiments were conducted on sapphire substrates using a DSPG machine. Theoretical predictions of the material removal rate were then juxtaposed with experimental outcomes across varying grinding pressures and rotational speeds. The trends between theoretical and experimental values showed remarkable consistency, with deviations ranging between 0.2% and 39.2%, thereby substantiating the model's validity. Moreover, leveraging the insights from this model, we optimized the disparity in the material removal rate between two surfaces of the substrate, thereby enhancing the uniformity of the machining process across both surfaces.

Ex Tenebris Lux: Illuminating Reactive Oxygen and Nitrogen Species with Small Molecule Probes.

Reactive oxygen and nitrogen species are small reactive molecules derived from elements in the air─oxygen and nitrogen. They are produced in biological systems to mediate fundamental aspects of cellular signaling but must be very tightly balanced to prevent indiscriminate damage to biological molecules. Small molecule probes can transmute the specific nature of each reactive oxygen and nitrogen species into an observable luminescent signal (or even an acoustic wave) to offer sensitive and selective imaging in living cells and whole animals. This review focuses specifically on small molecule probes for superoxide, hydrogen peroxide, hypochlorite, nitric oxide, and peroxynitrite that provide a luminescent or photoacoustic signal. Important background information on general photophysical phenomena, common probe designs, mechanisms, and imaging modalities will be provided, and then, probes for each analyte will be thoroughly evaluated. A discussion of the successes of the field will be presented, followed by recommendations for improvement and a future outlook of emerging trends. Our objectives are to provide an informative, useful, and thorough field guide to small molecule probes for reactive oxygen and nitrogen species as well as important context to compare the ecosystem of chemistries and molecular scaffolds that has manifested within the field.

Peripheral Injection of hUC-MSCs in the Treatment of Acute Liver Failure: A Pre-Clinical Cohort Study in Rhesus Monkeys.

Background: Using a toxin-induced lethal acute liver failure (ALF) monkey model, we have recently shown that early peripheral infusion of human umbilical cord mesenchymal stem cells (hUC-MSCs) can alleviate liver damage and improve animal survival by suppressing the activation of circulating monocytes and the subsequent cytokine storm. Here, we explored whether the administration of hUC-MSCs could still improve ALF when the cytokine storm is fully developed. Method: We treated ALF monkeys with peripheral delivery of hUC-MSCs at 48 hr after toxin challenge. Liver indices, histology, imaging, and animal survival were recorded and analyzed. Results: In our cohort study, we conducted and demonstrated that the infusion of hUC-MSCs significantly improved liver histology, effectively controlled inflammatory cytokine storms, and increased survival rates. Additionally, the administration of a higher dose of hUC-MSCs (2 × 107/monkey) yielded superior outcomes compared to a lower dose (1 × 107/monkey). Conclusion: Treatment of hUC-MSCs can significantly improve the pathological and survival outcomes of ALF even when the cytokine storm has been fully developed, indicating a promising clinical solution for ALF.

Highly Enantioselective Hydrogenation of Unsymmetrical Benzophenones via Iridium-f-phamidol Catalysis.

A sequence of f-phamidol-based tetradentate phosphine ligands have been developed and successfully used in iridium-catalyzed enantioselective hydrogenation of benzophenones to deliver chiral benzhydrols in almost quantitative yields and with excellent enantioselectivities (up to >99% yield and up to >99% ee). Moreover, the catalytic system shows a broad substrate scope and functional group tolerance. The synthetic utilities of this methodology have been showcased by gram-scale experiments and the formal synthesis of levocetirizine.

Probing the Spatial Homogeneity of Exfoliated HfTe5 Films.

In van der Waals materials, external strain is an effective tool to manipulate and control electronic responses by changing the electronic bands upon lattice deformation. In particular, the band gap of the layered transition metal pentatelluride HfTe5 is sufficiently small to be inverted by subtle changes of the lattice parameters resulting in a strain-tunable topological phase transition. In that case, knowledge about the spatial homogeneity of electronic properties becomes crucial, especially for the microfabricated thin film circuits used in typical transport measurements. Here, we reveal the homogeneity of exfoliated HfTe5 thin films by spatially resolved Raman microscopy. Comparing the Raman spectra under applied external strain to unstrained bulk references, we pinpoint local variations of Raman signatures to inhomogeneous strain profiles in the sample. Importantly, our results demonstrate that microfabricated contacts can act as sources of significant inhomogeneities. To mitigate the impact of unintentional strain and its corresponding modifications of the electronic structure, careful Raman microscopy constitutes a valuable tool for quantifying the homogeneity of HfTe5 films and circuits fabricated thereof.

Tunable Pt-NiO interaction-induced efficient electrocatalytic water oxidation and methanol oxidation.

Metal-support interaction engineering is considered an efficient strategy for optimizing the catalytic activity. Nevertheless, the fine regulation of metal-support interactions as well as understanding the corresponding catalytic mechanisms (particularly those of non-carbon support-based counterparts) remains challenging. Herein, a controllable adsorption-impregnation strategy was proposed for the preparation of a porous nonlayered 2D NiO nanoflake support anchored with different forms of Pt nanoarchitectures, i.e. single atoms, clusters and nanoparticles. Benefiting from the unique porous architecture of NiO nanosheets, abundant active defect sites facilitated the immobilization of Pt single atoms onto the NiO crystal, resulting in NiO lattice distortion and thus changing the valence state of Pt, chemical bonding, and the coordination environment of the metal center. The synergy of the porous NiO support and the unexpected Pt single atom-NiO interactions effectively accelerated mass transfer and reduced the reaction kinetic barriers, contributing to a significantly enhanced mass activity of 5.59 A mgPt -1 at an overpotential of 0.274 V toward the electrocatalytic oxygen evolution reaction (OER) while 0.42 A mgPt -1 at a potential of 0.7 V vs. RHE for the methanol oxidation reaction (MOR) in an alkaline system, respectively. This work may offer fundamental guidance for developing metal-loaded/dispersed support nanomaterials toward electrocatalysis through the fine regulation of metal-support interactions.

Characterization and Genomic Analysis of Affinirhizobium gouqiense sp. nov. Isolated from Seawater of Gouqi Island Located in the East China Sea and Reclassification of Rhizobium lemnae to the Genus Affinirhizobium as Affinirhizobium lemnae comb. nov.

A novel bacterium designated as SSA5.23T was isolated from seawater. Cells of SSA5.23T are Gram-stain-negative, short, rod-shaped, and exhibit motility via numerous peritrichous flagella. The strain could grow at temperatures ranging from 15 to 35 °C (optimum at 25 °C), in a salinity range of 0-5.0% (w/v) NaCl, and within a pH range of 6.0-9.0 (optimum at pH 7.0). The predominant cellular fatty acid of SSA5.23T was C18:1 ω7c/C18:1 ω6c, and the major respiratory quinones were Q-9 and Q-10. Diphosphatidylglycerol, phosphatidylethanolamine, and phosphatidylglycerol were identified as the primary polar lipids. The complete genome (5.47 Mb) of SSA5.23T comprises of a circular chromosome of 3.64 Mb and three plasmids, specifically sized at 59.73 kb, 227.82 kb, and 1.54 Mb, respectively. Certain genes located on the plasmids play roles in denitrification, oxidative stress resistance, and osmotic tolerance, which likely contribute to the adaptability of this strain in marine conditions. Core-proteome average amino acid identity analysis effectively identified the strain's affiliation with the genus Affinirhizobium, showing the highest value (89.9%) with Affinirhizobium pseudoryzae DSM 19479T. This classification was further supported by the phylogenetic analysis of concatenated alignment of 170 single-copy orthologous proteins. When compared to related reference strains, SSA5.23T displayed an average nucleotide identity ranging from 74.9 to 80.3% and digital DNA-DNA hybridization values ranging from 19.9 to 23.9%. Our findings confirmed that strain SSA5.23T represents a novel species of the genus Affinirhizobium, for which the name Affinirhizobium gouqiense sp. nov. (type strain SSA5.23T = LMG 32560T = MCCC 1K07165T) was suggested.

Robust, scalable, and highly selective spirocyclic catalysts for industrial hydroformylation and isomerization-hydroformylation.

Hydroformylation (HF) or isomerization-hydroformylation (ISO-HF) represents the most direct and practical route for producing aldehydes on an industrial scale. To resolve the issues of low activity, low linear/branched (l/b) ratio, and low stability in HF and ISO-HF, we herein reported a class of spirocyclic diphosphites. Notably, the ligand termed O-SDPhite afforded excellent catalytic activity and regioselectivity for the HF of various olefins. Excellent l/b ratio and an unprecedented turnover number of up to 17,620,000 were achieved. O-SDPhite was also found to be effective in the regioselective ISO-HF of the industrially related cheap and abundant C4 Raffinates to n-valeraldehyde produced on a multimillion-ton scale. The reaction with O-SDPhite, superior to that of benchmark Biphephos, was continuously operated for 41 days and afforded an average 38.6 l/b ratio (31 days and 14.7 l/b ratio for Biphephos).

Celastrol alleviates diabetic vascular injury via Keap1/Nrf2-mediated anti-inflammation.

Introduction: Celastrol (Cel) is a widely used main component of Chinese herbal medicine with strong anti-inflammatory, antiviral and antitumor activities. In the present study, we aimed to elucidate the cellular molecular protective mechanism of Cel against diabetes-induced inflammation and endothelial dysfunction. Methods: Type 2 diabetes (T2DM) was induced by db/db mice, and osmotic pumps containing Cel (100 µg/kg/day) were implanted intraperitoneally and were calibrated to release the drug for 28 days. In addition, human umbilical vein endothelial cells (HUVECs) were cultured in normal or high glucose and palmitic acid-containing (HG + PA) media in the presence or absence of Cel for 48 h. Results: Cel significantly ameliorated the hyperglycemia-induced abnormalities in nuclear factor (erythroid-derived 2)-like protein 2 (Nrf2) pathway activity and alleviated HG + PA-induced oxidative damage. However, the protective effect of Cel was almost completely abolished in HUVECs transfected with short hairpin (sh)RNA targeting Nrf2, but not by nonsense shRNA. Furthermore, HG + PA reduced the phosphorylation of AMP-activated protein kinase (AMPK), the autophagic degradation of p62/Kelch-like ECH-associated protein 1 (Keap1), and the nuclear localization of Nrf2. However, these catabolic pathways were inhibited by Cel treatment in HUVECs. In addition, compound C (AMPK inhibitors) and AAV9-sh-Nrf2 reduced Cel-induced Nrf2 activation and angiogenesis in db/db mice. Discussion: Taking these findings together, the endothelial protective effect of Cel in the presence of HG + PA may be at least in part attributed to its effects to reduce reactive oxygen species (ROS) and inflammation through p62/Keap1-mediated Nrf2 activation.

Corrigendum: Fat fraction quantification with MRI estimates tumor proliferation of hepatocellular carcinoma.

[This corrects the article DOI: 10.3389/fonc.2024.1367907.].

Monolithic Layered Silicon Composed of a Crystalline-Amorphous Network for Sustainable Lithium-Ion Battery Anodes.

While nanostructural engineering holds promise for improving the stability of high-capacity silicon (Si) anodes in lithium-ion batteries (LIBs), challenges like complex synthesis and the high cost of nano-Si impede its commercial application. In this study, we present a local reduction technique to synthesize micron-scale monolithic layered Si (10-20 µm) with a high tap density of 0.9-1.0 g cm-3 from cost-effective montmorillonite, a natural layered silicate mineral. The created mesoporous structure within each layer, combined with the void spaces between interlayers, effectively mitigates both lateral and vertical expansion throughout repeated lithiation/delithiation cycles. Furthermore, the remaining SiO2 network fortifies the layered structure, preventing it from collapsing during cycling. Half-cell tests reveal a capacity retention of 92% with a reversible capacity of 1130 mAh g-1 over 500 cycles. Moreover, the pouch cell integrated with this Si anode (with a mass loading of 3.0 mg cm-2) and a commercial NCM811 cathode delivers a high energy density of 655 Wh kg-1 (based on the total mass of the cathode and anode) and maintains 82% capacity after 200 cycles. This work demonstrates a cost-efficient and scalable strategy to manufacture high-performance micron Si anodes for the ever-growing demand for high-energy LIBs.

Design, synthesis, and anti-oomycete activity of 3-acyloxymaltol/ethyl maltol derivatives.

Twenty 3-acyloxymaltol/ethyl maltol derivatives (7a-j and 8a-j) were synthesized and evaluated in vitro for their anti-oomycete activity against Phytophthora capsici, respectively. Among all of twenty derivatives, more than half of the compounds 7f, 7h, 8a-h and 8j had anti-oomycete activity higher than the positive control zoxamide (EC50 = 22.23 mg/L), and the EC50 values of 18.66, 20.32, 12.80, 16.18, 10.59, 14.98, 16.80, 10.36, 15.32, 12.64, and 13.59 mg/L, respectively. Especially, compounds 8c and 8f exhibited the best anti-oomycete activity against P. capsici with EC50 values of 10.59 and 10.36 mg/L, respectively. Overall, hydroxyl group of maltol/ethyl maltol is important active modification site.