Search

The low-pressure phase transformation of graphite to diamond has been confirmed with the help of a tantalum, hydrogen, and oxygen composited atmosphere in chemical vapor deposition. Subsequent theoretical calculations revealed the phase-transformation mechanism induced by a monodisperse transition-metal (TM) with an appropriate atomic radius (1.36–1.60 Å) and unfilled d-orbitals (d2s2–d7s2) on an H-terminated diamond substrate. However, the specific role of oxygen in TM-induced phase transformation remains unclear. Herein, we employed first-principles calculations to elucidate how oxygen assists the monodisperse TM in inducing ordinary-pressure phase transformation of graphite to diamond. Results show that the adsorption energy of the TM on the O-terminated diamond substrate was lower and the diffusion barrier was higher than that for its hydrogen counterpart, thereby effectively promoting their existence in a monodisperse state. These monodisperse TM atoms reduce the energy barrier of the phase transformation. This is attributed to the hybridization of unpaired electrons in the d-orbitals of the TM with the pz-orbitals of carbon, resulting in charge transfer within graphene from a horizontal to a vertical direction, leading to a transition from sp2-C to sp3-C. Specifically, TMs with the electronic configuration of d9s1, such as Au, have a weak role in phase transition on H-terminated diamond, while on O-terminated diamond, oxygen takes away the electrons of Au to generate more unpaired electrons that can bond to carbon, significantly promoting the phase transformation. For TMs with electronic configurations of d7s2 to d3s2, the bonding of their unpaired electrons to carbon is largely unaffected by oxygen; thus, oxidation has little influence on the phase transition. In the case of d2s2, oxygen takes away all the unpaired d-orbital electrons, thus preventing the TMs from bonding to carbon and providing no contribution to the phase transformation. Our findings offer guidance for the preparation of diamond based on graphite at ordinary pressure. [ABSTRACT FROM AUTHOR]

Ciliated muconodular papillary tumor (CMPT) is a rare pulmonary tumor, typically occurring in middle-aged and elderly individuals. The molecular mutation spectrum of CMPT remains insufficiently explored. Commonly known driver gene alterations include KRAS, BRAF, EGFR, and ALK rearrangement. This report details the clinicopathological features of 2 patients presenting with CMPT as pulmonary nodules during clinical examinations. Microscopic analysis revealed tumors with glandular or papillary structures, consisting of mucinous cells, ciliated columnar cells, and basal cells. Notably, both patients exhibited STRN::ALK fusion, a finding not previously associated with CMPT. STRN::ALK fusion serves as a target for therapy in various tumors, including non-small cell lung cancer, thyroid cancer, and colon cancer. Consequently, we conducted a review of relevant literature, summarizing the clinicopathological and molecular characteristics of CMPT to facilitate further research. Our insights enhance the understanding of this uncommon tumor and contribute to the expansion of its molecular alteration spectrum. [ABSTRACT FROM AUTHOR]

Recently emerging lithium ternary chlorides have attracted increasing attention for solid‐state electrolytes (SSEs) due to their favorable combination between ionic conductivity and electrochemical stability. However, a noticeable discrepancy in Li‐ion conductivity persists between chloride SSEs and organic liquid electrolytes, underscoring the need for designing novel chloride SSEs with enhanced Li‐ion conductivity. Herein, an intriguing trigonal structure (i.e., Li3SmCl6 with space group P3112) is identified using the global structure searching method in conjunction with first‐principles calculations, and its potential for SSEs is systematically evaluated. Importantly, the structure of Li3SmCl6 exhibits a high ionic conductivity of 15.46 mS cm−1 at room temperature due to the 3D lithium percolation framework distinct from previous proposals, associated with the unique in‐plane cation ordering and stacking sequences. Furthermore, it is unveiled that Li3SmCl6 possesses a wide electrochemical window of 0.73−4.30 V vs Li+/Li and excellent chemical interface stability with high‐voltage cathodes. Several other Li3MCl6 (M = Er, and In) materials with isomorphic structures to Li3SmCl6 are also found to be potential chloride SSEs, suggesting the broader applicability of this structure. This work reveals a new class of ternary chloride SSEs and sheds light on strategy for structure searching in the design of high‐performance SSEs. [ABSTRACT FROM AUTHOR]

Simple Summary: The two closely related maize and rice weevils exhibit differential host preferences among stored maize, wheat, and paddy grains. The maize weevil adults prefer to select maize, followed by paddy and wheat, while rice weevil adults mainly migrate towards wheat. The 2-ethylhexanol, piperitone, and (+)-Δ-cadiene are the major components in volatiles from both maize and wheat, but the abundance of these chemicals is much lower in maize than in wheat. The volatile limonene was only detected in paddy. The 2-ethylhexanol, piperitone, and (+)-Δ-cadiene were all attractive to both weevils, whereas limonene was attractive only to rice weevils. The different volatile profiles among the grains and the sensitivity of the two pest species towards these volatiles may explain the behavioral differences between maize and rice weevils in selecting host grains. The variance in sensitivity of maize and rice weevils towards host volatile chemicals with abundance differences is likely a determinant driving the two insect species to migrate towards different host grains. The Sitophilus zeamais (maize weevil) and Sitophilus oryzae (rice weevil) are two insect pests that have caused huge economic losses to stored grains worldwide. It is urgent to develop an environmentally friendly strategy for the control of these destructive pests. Here, the olfactory-mediated selection preference of the two weevil species to three stored grains was analyzed, which should help establish a pull–push system in managing them. Bioassays showed that maize weevil adults prefer to select maize, followed by paddy and wheat, while rice weevil adults mainly migrate towards wheat. Volatile analyses revealed that 2-ethylhexanol, piperitone, and (+)-Δ-cadiene are the major components in volatiles from both maize and wheat, but the abundance of these chemicals is much lower in maize than that in wheat. The volatile limonene was only detected in paddy. Y-tube bioassays suggest that 2-ethylhexanol, piperitone, and (+)-Δ-cadiene were all attractive to both weevils, whereas limonene was attractive only to rice weevils. Overall, maize weevil appeared more sensitive to the tested volatiles based on having much lower effective concentrations of these volatiles needed to attract them. The differences in volatile profiles among the grains and the sensitivity of the two species towards these volatiles may explain the behavioral differences between maize and rice weevils in selecting host grains. The differences in sensitivity of maize and rice weevils towards host volatile components with abundance differences are likely determinants driving the two insect species to migrate towards different host grains. [ABSTRACT FROM AUTHOR]

Background: Patients who possess various histological subtypes of early‐stage lung adenocarcinoma (LUAD) have considerably diverse prognoses. The simultaneous existence of several histological subtypes reduces the clinical accuracy of the diagnosis and prognosis of early‐stage LUAD due to intratumour intricacy. Methods: We included 11 postoperative LUAD patients pathologically confirmed to be stage IA. Single‐cell RNA sequencing (scRNA‐seq) was carried out on matched tumour and normal tissue. Three formalin‐fixed and paraffin‐embedded cases were randomly selected for 10× Genomics Visium analysis, one of which was analysed by digital spatial profiler (DSP). Results: Using DSP and 10× Genomics Visium analysis, signature gene profiles for lepidic and acinar histological subtypes were acquired. The percentage of histological subtypes predicted for the patients from samples of 11 LUAD fresh tissues by scRNA‐seq showed a degree of concordance with the clinicopathologic findings assessed by visual examination. DSP proteomics and 10× Genomics Visium transcriptomics analyses revealed that a negative correlation (Spearman correlation analysis: r = –.886; p =.033) between the expression levels of CD8 and the expression trend of programmed cell death 1(PD‐L1) on tumour endothelial cells. The percentage of CD8+ T cells in the acinar region was lower than in the lepidic region. Conclusions: These findings illustrate that assessing patient histological subtypes at the single‐cell level is feasible. Additionally, tumour endothelial cells that express PD‐L1 in stage IA LUAD suppress immune‐responsive CD8+ T cells. [ABSTRACT FROM AUTHOR]

We performed the CH4/(Ar–H2) plasma post-treatments on ultrananocrystalline diamond films prepared by hot filament chemical vapor deposition. The results show that during the CH4/(Ar–H2) plasma treatment, 3–5 nm diamond grains agglomerate and regrow, and the graphite between the grains transformed into diamond due to the combined action of hydrogen and tantalum atoms in the samples. This produces bigger diamond grains in size of 200 nm with a large number of stacking faults formed during the grain aggregation, and the graphite phase is greatly reduced. Moreover, the electron field emission (EFE) performance of the films is significantly improved after the CH4/(Ar–H2) plasma treatment. This suggests that the improved EFE performance is not caused by the graphite phase, but by the diamond grains with lots of stacking faults that provide transport channels for electrons. This provides a method for enhancing the EFE properties of diamond films. [ABSTRACT FROM AUTHOR]

The proliferation of ICT in today's world of work particularly in education has necessitated the need to assess lecturers' views of online assessment use in the covid‐19 era given the disruptions in face‐to‐face teaching and learning process. The study adopted a mixed research design. The population for the study was 84 computer educators made up of 40 males and 44 females from the four public tertiary institutions in Enugu State, Nigeria. Three research questions and two hypotheses guided the study. The instruments used for data collection were a structured questionnaire titled "Computer Educators' Perception of Use of Online Assessment" (CEPUOA) and a guided interview relating to the research questions. The internal consistency was determined using the Cronbach α reliability test which gave an index of.9. The data collected were analyzed using mean and standard deviation while the null hypotheses were tested using a t‐test at 0.05 level of significance. The findings of the study indicated that computer educators have a positive disposition toward the use of online assessment in conducting various assessment techniques such as tests/quizzes, semester examinations, and seminar/project evaluations. The findings of the study further showed that the utilization of online assessment techniques facilitates timely monitoring of students' progress, and the provision of immediate feedback to the learners helps in preparing students with digital skills required to function in the 21st‐century workplace, among others. In view of these, it was recommended that tertiary institutions should initiate workable policies that will encourage the effective use of online assessment by lecturers. [ABSTRACT FROM AUTHOR]

Potassium ion batteries (KIBs) have received increasing popularity owing to their distinct advantages. We discover a hitherto unknown C4S nanosheet, a novel carbon-based material with carbon and sulfur consisting of pentagons and hexagons rings. The proposed C4S nanosheet is highly stable dynamically, thermodynamically, mechanically, and chemically, according to first-principles calculations. Moreover, the graphene-like C4S nanosheet is a prospective KIBs anode material, which has a metallic band structure, a relatively low diffusion barrier (0.07 eV), a large capacity (1340 mA h g−1), and an acceptable average voltage (0.44 V). Finally, we demonstrate good cycling stability of the C4S nanosheet. Our findings indicate that the proposed C4S nanosheet is a potentially favorable KIBs anode material. [ABSTRACT FROM AUTHOR]