Rose-like NiCo2O4 with Atomic-Scale Controllable Oxygen Vacancies for Modulating Sulfur Redox Kinetics in Lithium-Sulfur Batteries.

The long-term stability of Li-S batteries is significantly compromised by the shuttle effect and insulating nature of active substance S, constraining their commercialization. Developing efficient catalysts to mitigate the shuttle effect of lithium polysulfides (LiPSs) is still a challenge. Herein, we designed and synthesized a rose-like cobalt-nickel bimetallic oxide catalyst NiCo2O4-OV enriched with oxygen vacancies (OV) and verified the controllable synthesis of different contents of OV. Introducing the OV proved to be an efficient approach for controlling the electronic structure of the electrocatalyst and managing the absorption/desorption processes on the reactant surface, thereby addressing the challenges posed by the LiPS shuttle effect and sluggish transformation kinetics in Li-S batteries. In addition, we investigated the effect of OV in NiCo2O4 on the adsorption capacity of LiPSs using adsorption experiments and density functional theory (DFT) simulations. With the increase in the level of OV, the binding energy between the two is enhanced, and the adsorption effect is more obvious. NiCo2O4-OV contributes to the decomposition of Li2S and diffusion of Li+ in Li-S batteries, which promotes the kinetic process of the batteries.

Relieving Stress Concentration through Anion-Cation Codoping toward Highly Stable Nickel-Rich Cathode.

Nickel-rich LiNi0.8Co0.15Al0.015O2 (NCA) with excellent energy density is considered one of the most promising cathodes for lithium-ion batteries. Nevertheless, the stress concentration caused by Li+/Ni2+ mixing and oxygen vacancies leads to the structural collapse and obvious capacity degradation of NCA. Herein, a facile codoping of anion (F-)-cation (Mg2+) strategy is proposed to address these problems. Benefiting from the synergistic effect of F- and Mg2+, the codoped material exhibits alleviated Li+/Ni2+ mixing and demonstrates enhanced electrochemical performance at high voltage (≥4.5 V), outperformed the pristine and F-/Mg2+ single-doped counterparts. Combined experimental and theoretical studies reveal that Mg2+ and F- codoping decreases the Li+ diffusion energy barrier and enhances the Li+ transport kinetics. In particular, the codoping synergistically suppresses the Li+/Ni2+ mixing and lattice oxygen escape, and alleviates the stress-strain accumulation, thereby inhibiting crack propagation and improving the electrochemical performance of the NCA. As a consequence, the designed Li0.99Mg0.01Ni0.8Co0.15Al0.05O0.98F0.02 (Mg1+F2) demonstrates a much higher capacity retention of 82.65% than NCA (55.69%) even after 200 cycles at 2.8-4.5 V under 1 C. Furthermore, the capacity retention rate of the Mg1+F2||graphite pouch cell after 500 cycles is 89.6% compared to that of the NCA (only 79.4%).

High-Performance Infrared Detectors Based on Black Phosphorus/Carbon Nanotube Heterojunctions.

Infrared detectors have broad application prospects in the fields of detection and communication. Using ideal materials and good device structure is crucial for achieving high-performance infrared detectors. Here, we utilized black phosphorus (BP) and single-walled carbon nanotube (SWCNT) films to construct a vertical van der Waals heterostructure, resulting in high-performance photovoltaic infrared detectors. In the device, a strong built-in electric field was formed in the heterojunction with a favored energy-band matching between the BP and the SWCNT, which caused a good photovoltaic effect. The fabricated devices exhibited a diode-like rectification behavior in the dark, which had a high rectification ratio up to a magnitude of 104 and a low ideal factor of 1.4. Under 1550 nm wavelength illumination, the 2D BP/SWCNT film photodetector demonstrated an open-circuit voltage of 0.34 V, a large external power conversion efficiency (η) of 7.5% and a high specific detectivity (D*) of 3.1 × 109 Jones. This external η was the highest among those for the photovoltaic devices fabricated with the SWCNTs or the heterostructures based on 2D materials and the obtained D* was also higher than those for most of the infrared detectors based on 2D materials or carbon materials. This work showcases the application potential of BP and SWCNTs in the detection field.

Intestinal preservation in a birdlike dinosaur supports conservatism in digestive canal evolution among theropods.

Dromaeosaurids were bird-like dinosaurs with a predatory ecology known to forage on fish, mammals and other dinosaurs. We describe Daurlong wangi gen. et sp. nov., a dromaeosaurid from the Lower Cretaceous Jehol Biota of Inner Mongolia, China. Exceptional preservation in this specimen includes a large bluish layer in the abdomen which represents one of the few occurrences of intestinal remnants among non-avian dinosaurs. Phylogenetically, Daurlong nests among a lineage of short-armed Jehol Biota species closer to eudromaeosaurs than microraptorines. The topographic correspondence between the exceptionally preserved intestine in the more stem-ward Scipionyx and the remnants in the more birdlike Daurlong provides a phylogenetic framework for inferring intestine tract extent in other theropods lacking fossilized visceral tissues. Gastrointestinal organization results conservative among faunivorous dinosaurs, with the evolution of a bird-like alimentary canal restricted to avialan theropods.

A signature of immune-related gene pairs (IRGPs) for risk stratification and prognosis of oral cancer patients.

BACKGROUND: With low response to present immunotherapy, it is imperative to identify new immune-related biomarkers for more effective immunotherapies for oral cancer. METHODS: RNA profiles for 390 oral cancer patients and 32 normal samples were downloaded from The Cancer Genome Atlas (TCGA) database and differentially expressed genes (DEGs) were analyzed. Immune genesets from ImmPort repository were overlapped with DEGs. After implementing univariate Cox analysis and the least absolute shrinkage and selection operator (LASSO) Cox regression analysis, key immune-related gene pairs (IRGPs) among the overlapped DEGs for predicting the survival risk were obtained. Then, the cutoff of risk score was calculated by the receiver operating characteristic (ROC) curve to stratify oral cancer patients into high and low-risk groups. Multivariate Cox analysis was used to analyze independent prognostic indicators for oral cancer. Besides, infiltration of immune cells, functional annotation, and mutation analysis of IRGPs were conducted. Biological functions correlated with IRGPs were enriched by Gene Set Enrichment Analysis (GSEA) method. RESULTS: We identified 698 differentially expressed genes (DEGs) in response to oral cancer. 17 IRGPs among the DEGs were identified and integrated into a risk score model. Patients in the high-risk group have a significantly worse prognosis than those in the low-risk group in both training (P<0.001) and test (P=0.019) cohorts. Meanwhile, the IRGP model was identified as an independent prognostic factor for oral cancer. Different infiltration patterns of immune cells were found between the high- and low-risk groups that more types of T and B cells were enriched in the low-risk group. More immune-related signaling pathways were highly enriched in the low-risk group and Tenascin C (TNC) was the most frequently mutated gene. We have developed a novel 17-IRGPs signature for risk stratification and prognostic prediction of oral cancer. CONCLUSION: Our study provides a foundation for improved immunotherapy and prognosis and is beneficial to the individualized management of oral cancer patients.

Large Scale Synthesis of Three-dimensional Hierarchical Porous Framework with High Conductivity and its Application in Lithium Sulfur Battery.

Quick capacity loss due to the polysulfide shuttle effects and poor rate performance caused by low conductivity of sulfur have always been obstacles to the commercial application of lithium sulfur batteries. Herein, an in-situ doped hierarchical porous biochar materials with high electron-ion conductivity and adjustable three-dimensional (3D) macro-meso-micropore is prepared successfully. Due to its unique physical structure, the resulting material has a specific surface area of 2124.9 m2 g-1 and a cumulative pore volume of 1.19 cm3 g-1 . The presence of micropores can effectively physically adsorb polysulfides and mesopores ensure the accessibility of lithium ions and active sites and give the porous carbon material a high specific surface area. The large pores provide channels for the storage of electrolyte and the transmission of ions on the surface of the substrate. The combined effect of these three kinds of pores and the N doping formed in-situ can effectively promote the cycle and rate performance of the battery. Therefore, prepared cathode can still reach a reversible discharge capacity of 616 mAh g-1 at a rate of 5 C. After 400 charge-discharge cycles at 1 C, the reversible capacity is maintained at 510.0 mAh g-1 . This new strategy has provided a new approach to the research and industrial-scale production of adjustable hierarchical porous biochar materials.

New material of Longipteryx (Aves: Enantiornithes) from the Lower Cretaceous Yixian Formation of China with the first recognized avian tooth crenulations.

We report on a new specimen of Longipteryx chaoyangensis from the Lower Cretaceous Yixian Formation in Chaoyang, Liaoning Province, China. The new material preserves previously unknown tooth crenulations. This is the first recognized tooth crenulations within Aves. It not only provides new information regarding the anatomy of the Longipteryx, but also sheds new light on the trophic specialization of this genus and even this family. It was discovered from the Yixian Formation, which is older than the Longipteryx chaoyangensis bearing-Jiufotang Formation. This new discovery also expands the known stratigraphic range of Longipteryx.

An advanced, new long-legged bird from the Early Cretaceous of the Jehol Group (northeastern China): insights into the temporal divergence of modern birds.

We describe a new ornithuromorph bird species, Gansus zheni from the Lower Cretaceous lacustrine deposits of the Jiufotang Formation (Jehol Group), Liaoning Province, China. A cladistic analysis resolves Gansus zheni as the sister taxon of the roughly contemporaneous Gansus yumenensis (Xiagou Formation, Gansu Province), and together as the most immediate outgroup to Ornithurae. Gansus zheni is the most advanced bird known today for the Jehol Biota. Its discovery provides the best-documented case of inter-basinal correlations (Jehol and Changma basins of Liaoning and Gansu provinces, respectively) using low-taxonomic clades of fossil birds. The existence of close relatives of Ornithurae in deposits formed at about 120 million years ago helps to mitigate the long-standing controversy between molecular and paleontological evidence for the temporal divergence of modern birds (Neornithes).

A new specimen of the Early Cretaceous bird Hongshanornis longicresta: insights into the aerodynamics and diet of a basal ornithuromorph.

The discovery of Hongshanornis longicresta, a small ornithuromorph bird with unusually long hindlimb proportions, was followed by the discovery of two closely related species, Longicrusavis houi and Parahongshanornis chaoyangensis. Together forming the Hongshanornithidae, these species reveal important information about the early diversity and morphological specialization of ornithuromorphs, the clade that contains all living birds. Here we report on a new specimen (DNHM D2945/6) referable to Hongshanornis longicresta that contributes significant information to better understand the morphology, trophic ecology, and aerodynamics of this species, as well as the taxonomy of the Hongshanornithidae. Most notable are the well-preserved wings and feathered tail of DNHM D2945/6, which afford an accurate reconstruction of aerodynamic parameters indicating that as early as 125 million years ago, basal ornithuromorphs had evolved aerodynamic surfaces comparable in size and design to those of many modern birds, and flight modes alike to those of some small living birds.

A new mammal skull from the Lower Cretaceous of China with implications for the evolution of obtuse-angled molars and 'amphilestid' eutriconodonts.

We report the discovery of Juchilestes liaoningensis, a new genus and species of eutriconodont mammal from the Lujiatun Site of the Lower Cretaceous Yixian Formation (123.2 +/- 1.0 Ma; Lower Aptian). The holotype preserves a partial skull and full dentition. Among eutriconodonts, its lower dentition is similar to taxa formerly assigned to the paraphyletic group of 'amphilestids'. Some have considered 'amphilestid' molars to represent the structural intermediate between the lower molars of the 'triconodont' pattern of cusps in alignment and the fully triangulate and more derived therian molars. However, 'amphilestid' taxa were previously represented only by the lower dentition. Our study reveals, for the first time, the upper dentition and skull structure of an 'amphilestid', and shows that at least some eutriconodonts have an obtuse-angled cusp pattern on molars in middle positions of the long molar series. Its petrosal is similar to those of other eutriconodonts and spalacotheroid 'symmetrodonts'. Our phylogenetic analyses suggest that (i) Juchilestes is most closely related to the Early Cretaceous Hakusanodon from Japan, in the same Eastern Asiatic geographic region; (ii) 'amphilestids' are not monophyletic; and (iii) eutriconodonts might not be a monophyletic group, although this hypothesis must be further tested.