A highly distorted ultraelastic chemically complex Elinvar alloy.

The development of high-performance ultraelastic metals with superb strength, a large elastic strain limit and temperature-insensitive elastic modulus (Elinvar effect) are important for various industrial applications, from actuators and medical devices to high-precision instruments1,2. The elastic strain limit of bulk crystalline metals is usually less than 1 per cent, owing to dislocation easy gliding. Shape memory alloys3-including gum metals4,5 and strain glass alloys6,7-may attain an elastic strain limit up to several per cent, although this is the result of pseudo-elasticity and is accompanied by large energy dissipation3. Recently, chemically complex alloys, such as 'high-entropy' alloys8, have attracted tremendous research interest owing to their promising properties9-15. In this work we report on a chemically complex alloy with a large atomic size misfit usually unaffordable in conventional alloys. The alloy exhibits a high elastic strain limit (approximately 2 per cent) and a very low internal friction (less than 2 × 10-4) at room temperature. More interestingly, this alloy exhibits an extraordinary Elinvar effect, maintaining near-constant elastic modulus between room temperature and 627 degrees Celsius (900 kelvin), which is, to our knowledge, unmatched by the existing alloys hitherto reported.

Metallic CoSb and Janus Co2AsSb monolayers as promising anode materials for metal-ion batteries.

Structural symmetry breaking plays a pivotal role in fine-tuning the properties of nano-layered materials. Here, based on the first-principles approaches we propose a Janus monolayer of metallic CoSb by breaking the out-of-plane structural symmetry. Specifically, within the CoSb monolayer by replacing the top-layer 'Sb' with 'As' atoms entirely, the Janus Co2AsSb monolayer can be formed, whose structure is confirmed via structural optimization and ab initio molecular dynamics simulations. Notably, the Janus Co2AsSb monolayer demonstrates stability at an elevated temperature of 1200 K, surpassing the stability of the CoSb monolayer, which remains stable only up to 900 K. We propose that both the CoSb and Janus Co2AsSb monolayers could serve as capable anode materials for power-driven metal-ion batteries, owing to their substantial theoretical capacity and robust binding strength. The theoretical specific capacities for Li/Na reach up to 1038.28/1186.60 mA h g-1 for CoSb, while Janus Co2AsSb demonstrates a marked improvement in electrochemical storage capacity of 3578.69/2215.38 mA h g-1 for Li/Na, representing a significant leap forward in this domain. The symmetry-breaking effect upgrades the CoSb monolayer, as a more viable contender for power-driven metal-ion batteries. Furthermore, electronic structure calculations indicate a notable charge transfer that augments the metallic nature, which would boost electrical conductivity. These simulations demonstrate that the CoSb and Janus Co2AsSb monolayers have immense potential for application in the design of metal-ion battery technologies.

Clinical efficacy and safety evaluation of Dermatophagoides farinae drops in the treatment of allergic rhinitis with epistaxis.

Summary: Background. Epistaxis is frequently observed in allergic rhinitis (AR) patients. However, few studies focus on the outcome of epistaxis with treatment of AR patients. This study aimed to retrospectively analyze the efficacy and safety of AR patients with epistaxis treated with sublingual immunotherapy (SLIT). Methods. A total of 74 patients aged 4-60 years with house dust mite (HDM)-induced AR accompanied by epistaxis and who completed 1 year of SLIT treatment with standard Dermatophagoides farinae (D. farinae) drops were enrolled in this study. The symptom scores, total medication scores (TMS), combined symptom and medication score (CSMS), visual analog scales (VAS), and bleeding score (BS) were assessed, as well as the nasal endoscopic examinations were performed to observe nasal signs. Results. The levels of symptom scores, TMS, CSMS, VAS, and BS at 0.5 year and 1 year of SLIT treatment were significantly lower than those at the baseline (all p less than 0.01). Also, statistical differences were seen in CSMS (p less than 0.05) and VAS (p less than 0.01) between 0.5 year and 1 year. As expected, BS was positively correlated with CSMS (r = 0.617, 95% CI 0.517-0.699) and VAS (r = 0.777, 95% CI 0.719-0.822) at all three time points. Conclusions. SLIT with D. farinae drops was effective and safe for AR patients with epistaxis, resulting in improving the symptoms of rhinitis while relieving the symptoms of epistaxis.

[Pulmonary artery stenosis after single lung transplantation: a case report and literature review].

Objective: To summarize and analyze the clinical features, treatment, and prognosis of pulmonary artery stenosis post-lung transplantation. Methods: A 62-year-old male patient was admitted to the hospital with a cough and chest tightness of over a year's duration, which had worsened in the last two months, leading to the diagnosis of idiopathic pulmonary fibrosis. The clinical data were observed and reviewed post-left allograft single lung transplantation. Literature searches were conducted using the keywords "lung transplantation" "stenosis, pulmonary artery" and "postoperative complications" in CNKI, Wanfang Medical Network, and PubMed databases up to December 2022. Results: On January 26, 2022, a left allograft single lung transplantation was performed under general anesthesia. Postoperatively, extracorporeal membrane oxygenation and mechanical ventilation were successfully weaned off at 22 hours and 2 days, respectively, with transfer from the intensive care unit 12 days after surgery. PaO2 and PaCO2 were 50 mmHg and 40 mmHg after deoxygenation. Both pulmonary CT angiography and ventilatory-perfusion imaging indicated stenosis of the left pulmonary anastomosis. Balloon dilation and pulmonary artery stenting were performed, with PaO2 and PaCO2 improving to 87 mmHg and 42 mmHg, respectively. The patient was discharged 102 days post-surgery, and was followed up for 1 year, with a good prognosis. Additionally, 36 related articles were retrieved, encompassing 69 cases with a median age of 53 years (38.5-59.0 years). Of these, 27.54% (19/69) were diagnosed with idiopathic pulmonary fibrosis, 46.38% (32/69) underwent single lung transplantation, with the primary clinical symptom being hypoxemia in 71.01% (49/69) cases. Left pulmonary artery anastomotic stenosis was observed in 43.48% (30/69), with 65.22% (45/69) being diagnosed in the late postoperative period. Interventional therapy was performed to 44.93% (31/69), with a mortality rate of 21.74% (15/69). Conclusions: The primary clinical manifestation of post-lung transplantation pulmonary artery stenosis is hypoxemia and can be diagnosed by pulmonary artery CT angiography, transesophageal echocardiography, and pulmonary angiography. Early diagnosis can significantly reduce mortality, and interventional therapy is an effective treatment for severe pulmonary artery stenosis post-lung transplantation.

[Application of computational fluid dynamics in the evaluation of left ventricular function in cardiomyopathies and coronary disease].

Computational fluid dynamics (CFD) is an emerging technology applied in the field of cardiovascular medicine, which can obtain hemodynamic data by simulating the blood flow in the patient's heart for cardiac function assessment and disease diagnosis. Left ventricular function plays a key role in the occurrence and development of cardiomyopathies and coronary disease. CFD can reconstruct the left ventricular anatomic structures of patients to clarify pathophysiologic mechanisms and analyze hemodynamic parameters to evaluate left ventricular function, verify surgical efficacy, and guide surgical strategy, which has a positive effect on achieving early diagnosis and reducing mortality from cardiomyopathies and coronary disease. At present, there are still technical limitations in the large-scale clinical application of CFD, and various solutions are being developed and tested, and further improvement and refinement are needed.

Exploring the absolute yield curve of secondary electrons using machine learning methods.

Knowledge of absolute secondary electron yield (δ) is important for various applications of electron emission materials. Besides, it is also crucial to know the dependence of δ on primary electron energy Ep and material properties like atomic number Z. The available experimental database of δ reveals a large discrepancy among the measurement data, while the oversimplified semi-empirical theories of secondary electron emission can only present the general shape of the yield curve but not the absolute yield value. This limits not only the validation of a Monte Carlo model for theoretical simulations but also presents large uncertainties in the applications of different materials for various purposes. In applications, it is highly desirable to have the knowledge of the absolute yield of a material. Therefore, it is highly desirable to establish the relationship of the absolute yield with material and electron energy based on the available experimental data. Recently, machine learning (ML) methods have been increasingly used for the prediction of material properties mainly based on the atomistic calculations with the first-principles theory. We propose here the application of ML models to a material property study, starting with experimental observations and unfolding the relationship of δ with basic material properties and primary electron energy. Our ML models are able to predict δ(Ep)-curve covering a wide energy range of 10 eV-30 keV for unknown elements within the uncertainty range of the experimental data and can suggest more reliable data among the scattered experimental data.

Theoretical prediction and characterization of novel two-dimensional ternary tetradymite compounds La2X2Y (X = I, Br, Cl; Y = Ge, Te) as anode materials for metal-ion batteries.

Tetradymite compounds, such as Bi2Te3, crystallizing in rhombohedral structures have triggered tremendous research interest from the scientific community because of their intriguing properties. Herein, using the state-of-the-art first-principles calculations, we identify that La2X2Y (X = I, Br, Cl; Y = Ge, Te) nanosheets exhibit a ternary tetradymite-type structure with extraordinary electrical and electrochemical properties. It is first demonstrated that the layered La2X2Y compounds exhibit weak interlayer coupling with cleavage energies in the range of ∼0.28-0.38 J m-2, allowing the ready separation of monolayers that can be synthesized by mechanical exfoliation from their bulk counterparts. Next, we predict that La2X2Ge nanosheets exhibit a semiconducting nature, and upon physical realistic strain, a Dirac cone can be realized. These findings can be exploited in the transport properties. Furthermore, we comprehensively investigated the electrochemical properties of the predicted systems to evaluate their potential use in metal-ion (Li/Na) batteries. Our detailed analyses reveal that the Li (Na) adatoms are sufficiently mobile on the surface of the studied systems. For instance, the binding energy for the Li (Na) adatom on La2I2Ge is -2.24(-1.79) eV with a diffusion barrier of as small as ∼0.31(0.20) eV. Subsequently, the maximum theoretical specific capacity for Li (Na) reaches as high as 887(1064) mA h g-1, which can be attributed to a much higher storage capacity compared to previously identified 2D anode materials. These findings substantiate that the predicted nanosheets could be synthesized to explore their potential applications in future metal-ion batteries.

A theoretical characterization method for non-spherical core-shell nanoparticles by XPS.

Core-shell nanoparticles (NPs) are active research areas for their unique properties and wide applications. By changing the elemental composition in the core and shell, a series of core-shell NPs with specific functions can be obtained, where the sizes of the core and shell also influence the properties. X-ray photoelectron spectroscopy (XPS) is useful in this context as a means of quantitatively analyzing such NPs. The empirical formula proposed by Shard [J. Phys. Chem. C, 2012, 116(31), 16806-16813] for calculating the shell thickness of the spherical core-shell NPs has been verified by Powell et al. [J. Phys. Chem. C, 2016, 120(39), 22730-22738] through a simulation of XPS with Simulation of Electron Spectra for Surface Analysis (SESSA) software. However, real core-shell NPs are not necessarily ideal spheres; such NPs can have rich shapes and uneven thicknesses. This work aims to extend the Shard formula to non-ideal core-shell NPs. We have used a Monte Carlo simulation method to study the XPS signal variation with the shell thickness for several modeled non-spherical shapes of core-shell NPs including some complex geometric structures which are numerically constructed with finite-element triangular meshes. Five types of non-spherical shapes, i.e. egg, ellipsoid, rod, rough-surface, and star shapes, are considered, while the size parameters are varied over a wide range. The equivalent radius and equivalent thickness are defined to characterize the average size of the nanoparticles for the use of the Shard formula. We have thus derived an extended Shard formula for the specific core-shell NPs, with which the relative error between the predicted shell thickness and the real thickness can be reduced to less than 10%.

[Treatment of orbital vascular malformations with intralesional bleomycin injection and N-butyl-2-cyanoacrylate glue embolization].

Objective: To evaluate the clinical efficacy of bleomycin lavage combined with N-butyl-2-cyanoacrylate glue embolization and resection in the treatment of orbital vascular malformations. Methods: It was a retrospective case series study. Patients with orbital vascular malformations diagnosed at the Ophthalmology Division of Chinese PLA General Hospital from January 2018 to October 2021 were included and divided into exophthalmos group and non-exophthalmos group based on whether the patients had postural exophthalmos. Intralesional bleomycin injection and N-butyl-2-cyanoacrylate glue embolization were performed. The preoperative and postoperative visual acuity, the dosages of bleomycin and isobutyl cyanoacrylate glue, pathological results, imaging findings and remission rate were recorded and analyzed. The Chi-square test, Wilcoxon signed rank analysis and Mann-Whitney U test were used for statistical analysis. Results: A total of 58 patients (58 eyes)were included, and there were 22 males (37.9%)　and 36 females (62.1%). Nineteen (32.8%) patients had postural exophthalmos, and 39 (67.2%) patients did not suffer postural exophthalmos. The patient's age of the two groups was 39.0 (28.0, 54.5) years vs. 14.0 (5.7, 26.5) years, with a statistically significant difference (Z=-3.96, P<0.001). There was no significant difference in gender, eye laterality, follow-up time and the disease course between the two groups (all P>0.05). During the operation, the dosage of bleomycin was 15 000 (13 500, 15 000) U in the exophthalmos group, and 15 000 (9 000, 16 500) U in the non-exophthalmos group (Z=-0.70, P=0.944). The dosages of N-butyl-2-cyanoacrylate glue were 2.8 (1.0, 3.0) ml and 1.7 (1.0, 2.2) ml, respectively, in the two groups, with no significant difference (Z=-1.11, P=0.268). There was no visual impairment in both groups, while the visual acuity in 5 patients without postural exophthalmos was improved postoperatively. The imaging examination results showed no difference in the malformed vascular area before and after the treatment in the exophthalmos group [384.0 (329.0, 458.0) mm2 vs. 330.5 (271.6, 356.7) mm2; Z=-1.26, P=0.208], but a significantly decreased area after the treatment in the non-exophthalmos group [960.8 (822.1, 1058.3) mm2 vs. 311.6 (164.6, 361.6) mm2; Z=-2.67, P=0.008]. All patients had no obvious local or systemic adverse reactions during the follow-up. The pathology reports showed vascular malformations in all 15 specimens obtained from the exophthalmos group, as well as vascular malformations in 41.0% (16/39) of specimens and venous lymphatic malformations in 59.0% (23/39) of specimens from the non-exophthalmos group. Thirty-nine patients had complete remission (67.2%), 19 patients had partial remission (32.8%), and the effective treatment rate was 100%. Conclusion: Bleomycin lavage combined with N-butyl-2-cyanoacrylate glue embolization can achieve good therapeutic effects on orbital vascular malformations.

[circ-WHSC1 affects the growth, metastasis and radiotherapy sensitivity of nasopharyngeal carcinoma cells by targeting miR-338-3p/ELAVL1 axis].

Objective: To study the effect of circ-WHSC1 on the growth, metastasis and radiosensitivity of nasopharyngeal carcinoma cells and its molecular mechanism. Methods: Cancerous tissues and adjacent tissues were collected from 23 patients with nasopharyngeal carcinoma, and real-time fluorescent quantitative PCR (RT-qPCR) was used to detect the expression levels of circ-WHSC1, miR-338-3p, and ELAVL1 mRNA. Western blot was used to detect the expression of ELAVL1 protein. Nasopharyngeal carcinoma cells 5-8F and SUNE1 were divided into si-NC group, si-circ-WHSC1 group, pCD5-ciR group, circ-WHSC1 group, anti-miR-NC group, anti-miR-338-3p group, miR-NC group, miR-338-3p group, si-circ-WHSC1+ anti-miR-NC group, si-circ-WHSC1+ anti-miR-338-3p group, miR-338-3p+ pcDNA group, miR-338-3p+ ELAVL1 group. Tetramethylazolium salt colorimetric method (MTT) was used to detect cell viability. Clone formation test was used to detect cell clone formation and cell radiosensitivity. Flow cytometry was used to detect cell apoptosis. Transwell was used to detect cell migration and invasion. Dual luciferase assay was used to detect the targeting relationship between circ-WHSC1 and miR-338-3p, miR-338-3p and ELAVL1. The SUNE1 cells stably transfected with sh-circ-WHSC1 were injected into nude mice and irradiated with radiation, and then the tumor volume and weight of mice were detected. Results: The expressions of circ-WHSC1 (1.57±0.94 vs 3.78±1.18, 1.00±0.10 vs 1.64±0.14/2.00±0.21/2.81±0.26/3.36±0.34) and ELAVL1 (1.28±0.74 vs 3.36±0.77, 1.00±0.08 vs 2.51±0.19/3.27±0.27) in nasopharyngeal carcinoma tissues and cells were increased, and the expression of miR-338-3p (3.13±0.96 vs 1.37±0.98, 1.00±0.08 vs 0.48±0.08/0.38±0.07) was decreased (P<0.05). After knockdown of circ-WHSC1, the activity of nasopharyngeal carcinoma cells was decreased [(100.00±8.00)% vs (51.33±8.62)%, (100.00±10.10)% vs (41.02±7.31)%], the number of clone-forming cells was decreased (101.00±8.54 vs 50.33±8.02, 114.00±14.10 vs 42.33±10.01), the rate of apoptosis was increased [(5.37±1.20)% vs (18.3±1.01)%, (6.5±1.18)% vs (22.43±1.40)%], and the numbers of migration (136.00±13.00 vs 72.33±9.50, 154.00±14.10 vs 62.67±11.50) and invasion (113.67±11.59 vs 60.67±9.07, 124.33±15.57 vs 50.33±9.01) were decreased; after different doses of radiation, the cell survival score was decreased (0.23±0.04 vs 0.06±0.01, 0.32±0.07 vs 0.05±0.02) (P<0.05). Circ-WHSC1 targeted and negatively regulated miR-338-3p. Inhibition of miR-338-3p affected the effect of knockdown of circ-WHSC1 on the proliferation, apoptosis, migration, invasion and radiosensitivity of nasopharyngeal carcinoma cells. MiR-338-3p targeted and negatively regulated ELAVL1; ELAVL1 overexpression affected the effects of miR-338-3p on the proliferation, apoptosis, migration, invasion and radiosensitivity of nasopharyngeal carcinoma cells. After the cells stably transfected with sh-circ-WHSC1 were injected into nude mice, the tumor volume [(884.67±95.63)mm(3) vs (487.33±76.51)mm(3)] and weight [(899.01±88.54)mg vs (558.67±75.04) mg] of the nude mice were reduced; after further irradiation, the tumor volume [(395.00±73.50)mm(3) vs 243.13±42.51)mm(3)] and weight[ (452.33±67.30)mg vs (211.09±57.51)mg] of the nude mice were reduced (P<0.05). Circ-WHSC1 regulated the expression of ELAVL1 by targeting miR-382. Conclusion: Knockdown of circ-WHSC1 can inhibit the growth and metastasis of nasopharyngeal carcinoma cells by targeting miR-338-3p/ELAVL1 axis, and enhances the radiosensitivity of nasopharyngeal carcinoma cells.

[Drought and Heat Stress-Mediated Modulation of Alternative Splicing in the Genes Involved in Biosynthesis of Metabolites Related to Tea Quality].

Alternative splicing (AS) regulates mRNAs at the post-transcriptional level to affect both their amounts and the protein function. However, little is known about the roles of AS in regulation of biosynthesis of amino acids, flavonoids, and volatile compounds in tea plants. In this study, we used Iso-seq and transcriptome deep sequencing (RNA-seq) to identify AS events, and analyzed the expression of respective mRNAs in tea plants under drought (DS), heat stress (HS), and their combination (HD). By RT-PCR, we validated the AS events in nine genes involved in the biosynthesis of amino acids and flavonoids. The genes accumulating AS transcripts under DS, HS, and HD conditions included those encoding for anthocyanidin reductase (ANR), dihydrofavonol-4-reductase-like (DFRA), and chalcone isomerase (CHI). Similarly, genes directly or indirectly involved in the biosynthesis of volatile compounds such as lipoxygenase (LOX), terpenoid/terpene synthase (TPS), and 1-deoxy-D-xylulose 5-phosphate reductoisomerase (DXR) also had AS events. Our study revealed that AS might specifically regulate the biosynthesis of amino acids in tea plants under stressful conditions. Moreover, we suggest that the AS events within the ANR and DFRA transcripts might play an important role in the regulation of flavonoid biosynthesis under DS, HS, and HD conditions. This study improved our understanding of the genetic drivers of the changes in the content of bioactive ingredients of tea plants subjected to abiotic stresses.

[Comparison of time series and case-crossover analyses in environmental epidemiology].

Time-series and case-crossover are two main study designs in environmental epidemiology. However, due to the differences in design principles and model construction between the two analyses, the results of the two analyses may not be consistent. Herein, we examined the short-term effect of cold spells on cardiovascular mortality in Nanjing using both time series and case-crossover analyses, aiming to provide a basis for the selection of appropriate research design in environmental epidemiology.

[Lung transplantation for pulmonary alveolar proteinosis: a case report and literature review].

Objective: To observe the efficacy of lung transplantation for pulmonary alveolar proteinosis (PAP) patients and to improve the understanding of the therapy. Methods: The clinical data of a patient with autoimmune PAP treated with sequential homogenous bilateral lung transplantation were described and the literatures were reviewed. Results: This 55-year-old female patient was diagnosed with autoimmune PAP and had been treated with whole lung lavage for 19 times, but only achieved short-term symptomatic relief after each operation. Inhalation of granulocyte macrophage colony stimulating factor occurred allergic reactions. Lung transplantation was performed on February 15, 2022, and a significant improvement in oxygenation and clinical symptoms were observed. The patient remained stable during follow-up. Conclusion: Treatment with lung transplantation is safe and effective for end-stage patients with PAP in the early phase, but the long-term effect remains to be observed.

[Soft tissue reconstruction strategy for sacral tumor resection].

Objective: To investigate the clinical strategy and effect of soft tissue reconstruction after sacral tumor resection in different planes. Methods: The data of 27 consecutive patients who underwent primary or secondary sacral tumor resection and soft tissue reconstruction from June 2012 to June 2021 at Dongnan Hospital of Xiamen University (the 909th Hospital) were retrospectively analyzed. There were 11 males and 16 females, aged (M(IQR)) (46.2±23.6) years (range: 16 to 72 years). Sacrospinous muscle, gluteus maximus and vertical rectus abdominis muscle flap were selected for soft tissue reconstruction according to the tumor site and the size of tissue defect. the postoperative follow-up was performed. The operative methods, intraoperative conditions, complications and disease outcomes were summarized. Results: Among the 27 patients with sacral tumor, the tumor plane was located in S1 in 8 cases, S2 in 5 cases and S3 or below in 14 cases. There were 12 patients with tumor volume≤400 cm3 and 15 patients with tumor volume>400 cm3. Operation time was 100(90) minutes (range: 70 to 610 minutes), intraoperative blood loss was 800(1 600) ml (range: 400 to 6 500 ml). Soft tissue reconstruction was performed by transabdominal rectus abdominis transfer repair in 2 cases, extraperitoneal rectus abdominis transfer repair in 1 case, gluteus maximus transfer repair in 5 cases, gluteus maximus advancement repair in 13 cases, and sacrospinous muscle transfer repair in 6 cases. Postoperative complications occurred in 6 cases, including 1 case of incision infection, 4 cases of skin border necrosis, and 1 case of delayed infection due to fracture of internal fixator 3 years after operation, all of them were cured. The follow-up time was (35±21) months. Among the patients, 6 patients had recurrence, 2 patients with Ewing sarcoma died of lung metastasis 1 year after operation, 4 patients with metastatic cancer died of primary disease, and the remaining patients survived without disease. Conclusion: Choosing different soft tissue reconstruction strategies according to sacral tumor location and tissue defect size can effectively fill the dead space after sacral tumor resection, reduce postoperative complications and improve the prognosis of patients.

Distinct Kondo Screening Behaviors in Heavy Fermion Filled Skutterudites with 4f

CeOs_{4}Sb_{12} (COS) and PrOs_{4}Sb_{12} (POS) are two representative compounds that provide the ideal vantage point to systematically study the physics of multi-f-electron systems. COS with Ce 4f^{1}, and POS with Pr 4f^{2} configurations show distinct properties of Kondo insulating and heavy fermion superconductivity, respectively. We unveiled the underlying microscopic origin by angle-resolved photoemission spectroscopy studies. Their eV-scale band structure matches well, representing the common characters of conduction electrons in ROs_{4}Sb_{12} systems (R=rare earth). However, f electrons interact differently with conduction electrons in COS and POS. Strong hybridization between conduction electrons and f electrons is observed in COS with band dependent hybridization gaps, and the development of a Kondo insulating state is directly revealed. Although the ground state of POS is a singlet, finite but incoherent hybridization exists, which can be explained by the Kondo scattering with the thermally excited triplet crystalline electric field state. Our results help us to understand the intriguing properties in COS and POS, and provide a clean demonstration of the microscopic differences in heavy fermion systems with 4f^{1} and 4f^{2} configurations.

Black phosphorene/blue phosphorene van der Waals heterostructure: a potential anode material for lithium-ion batteries.

Van der Waals (vdW) heterostructure-based electrodes have invoked tremendous research interest due to their intriguing properties and their capability to break the limitations of the restricted properties of single-material systems. Herein, based on first-principles approaches, we propose that the black phosphorene/blue phosphorene (BLK-P/BLE-P) vdW heterostructure can be a capable anode material for power-driving lithium-ion batteries (LIBs), as it exhibits a large theoretical capacity, together with a relatively strong binding strength compared with the individual BLK-P and BLE-P monolayers. Our calculation results show that the Li adatom prefers to intercalate into the interlayer of the BLK-P/BLE-P vdW heterostructure due to the synergistic interfacial effect, resulting in a high binding strength and a diffusivity comparable to the BLK-P and BLE-P monolayers. Subsequently, the theoretical specific capacity is found to be as high as 552.8 mA h g-1, which can be attributed to the much higher storage capacity of Li adatoms in the BLK-P/BLE-P vdW heterostructure. Furthermore, electronic structure calculations reveal that a large amount of charge transfer assists in semiconductor to metallic transition upon lithiation, which would ensure good electrical conductivity. These simulations prove that the BLK-P/BLE-P heterostructure has great potential in LIBs and is essential for future battery design.

Ensemble machine learning methods: predicting electron stopping powers from a small experimental database.

Electron stopping power (SP) is of great importance in theoretical and applied research areas specifically for Monte Carlo simulation studies in many microanalysis and surface analysis techniques, radiation dosimetry, and the design of particle detectors. However, experimental data are available for a dozen elemental materials only. On the other hand, the Bethe analytical expression of the SP is applicable at high energies only whereas no generally accepted formula exists at lower energies. We employed ensemble machine learning (ML) methods with the available experimental database for the prediction of SPs of electrons with energies from 100 keV down to 1 eV, in elements over the entire periodic table. With a small training database for electron SPs, we applied various algorithms individually as well as their ensembles, which have the credibility to enhance the prediction accuracy in the case of a small training database. Based on the model's performance evaluation tests, we concluded that the stacked generalization is more accurate than the individual algorithms. Using this method, we were able to predict the electron SPs for 54 elements (in total) including 12 elements that were present in the training database as well as for 42 elements beyond the training database over a wide energy range (1 eV to 100 keV). Compared to other theoretical approaches, the ML predicted SPs show very good agreement with the available experimental data at all energies. Moreover, unlike other theoretical approaches, the ML model does not need dielectric function data and other physical parameters which involve complex calculations. Using our ML model, we have predicted SPs for a further 14 elements for which no theoretical SPs are available because of the lack of good dielectric function data.

Optical properties of amorphous carbon determined by reflection electron energy loss spectroscopy spectra.

We present the combined experimental and theoretical investigations of the optical properties of amorphous carbon. The reflection electron energy loss spectra (REELS) spectra of carbon were measured using a cylindrical mirror analyzer under ultrahigh vacuum conditions at primary electron energies of 750, 1000 and 1300 eV. The energy loss function and thereby the refractive index n and the extinction coefficient k were determined from these REELS spectra in a wide loss energy range of 2-200 eV by applying our reverse Monte Carlo method. The high accuracy of the obtained optical constants is justified with the ps- and f-sum rules. We found that our present optical constants of amorphous carbon fulfill the sum rules with the highest accuracy compared with the previously published data. Therefore, we highly recommend to replace the previous data with the present ones for practical applications. Moreover, we present the atomic scattering factors of amorphous carbon obtained from the dielectric function to predict its optical constants at a given density.

Diagnostic value of maximum signal intensity on T1-weighted MRI images for differentiating parotid gland tumours along with pathological correlation.

AIM: To investigate the efficacy of the maximum signal intensity of tumour on T1-weighted magnetic resonance imaging (MRI) images for differentiating Warthin's tumours (WTs) from pleomorphic adenomas (PAs) and malignant tumours (MTs). MATERIALS AND METHODS: One hundred and fifty-four histopathologically confirmed parotid tumours, including 76 PAs, 45 WTs, and 33 MTs, were analysed. MRI results were compared with pathological findings. The maximum signal intensity of tumour and the average signal intensity of spinal cord were measured on T1-weighted images, then the tumour-to-spinal cord signal intensity ratio (T1-max-SIR) was calculated. The distribution of T1-max-SIRs among the three groups of tumours was analysed using the Mann-Whitney U-test. Receiver operating characteristic curves were generated to assess the ability of T1-max-SIRs to differentiate parotid tumours. In addition, the interobserver agreement between readers was assessed using interclass correlation coefficient (ICC). RESULTS: T1-max-SIRs were higher in WTs than in PAs (p<0.001) and MTs (p<0.001), and no significant difference was found between PAs and MTs (p=0.151). The area under the curve (AUC) of T1-max-SIRs for differentiating WTs from PAs was 0.901, with a sensitivity of 91.1% and a specificity of 82.9%. The AUC of T1-max-SIRs for differentiating WTs from MTs was 0.851, with a sensitivity of 88.9% and a specificity of 78.8%. Readers had excellent interobserver agreement on T1-max-SIRs (ICC = 0.989; 95% confidence interval, 0.985-0.992). CONCLUSIONS: T1-max-SIRs can be useful for differentiating WTs from PAs and MTs with high diagnostic efficiency.