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Atomically thin two-dimensional (2D) metals may be key ingredients in next-generation quantum and optoelectronic devices. However, 2D metals must be stabilized against environmental degradation and integrated into heterostructure devices at the wafer scale. The high-energy interface between silicon carbide and epitaxial graphene provides an intriguing framework for stabilizing a diverse range of 2D metals. Here we demonstrate large-area, environmentally stable, single-crystal 2D gallium, indium and tin that are stabilized at the interface of epitaxial graphene and silicon carbide. The 2D metals are covalently bonded to SiC below but present a non-bonded interface to the graphene overlayer; that is, they are 'half van der Waals' metals with strong internal gradients in bonding character. These non-centrosymmetric 2D metals offer compelling opportunities for superconducting devices, topological phenomena and advanced optoelectronic properties. For example, the reported 2D Ga is a superconductor that combines six strongly coupled Ga-derived electron pockets with a large nearly free-electron Fermi surface that closely approaches the Dirac points of the graphene overlayer.

Aiming at the problem of delayed repair of cracks in the airtight wall of the goaf, a method to initiate crack repair using microcapsules in the initial stage of crack evolution of the airtight wall (cracking period) is proposed. This method makes use of the stress at the crack tip. The microcapsule wall is torn to allow the repair agent wrapped in the wall of the capsule to flow out and fill the gap. After the curing reaction, crack repair is completed. During the crack repair process of the airtight wall, the particle size of the microcapsule affects the strength of the capsule wall and directly affects the repair effect. In order to study the influence of particle size on the strength of microcapsules, eight kinds of microcapsules with different particle diameters and the same wall thickness were prepared by orthogonal experiments. The particle size and wall thickness were characterized by SEM, and the strength of the capsule wall was measured using nanoindentation technology. The quadratic function relationship that the strength of the capsule wall decreases with the increase of the particle size is obtained.

Introduction: Older patients combined with coronary heart disease (CHD) develop acute heart failure (AHF) after hip fracture surgery is common, and this study aimed to investigate the risk factors of postoperative AHF in older hip fracture patients and to construct a nomogram prediction model. Methods: We retrospectively collected older hip fracture patients with CHD who underwent hip fracture surgery at the Third Hospital of Hebei Medical University from January 2017 to December 2021. We divided them into a training set and a validation set. We collected the demographic data, laboratory indicators and imaging examination results. We identified risk factors for postoperative AHF and used R language software to establish a nomogram prediction model, plot ROC curves, calibration curves and DCA decision curves. Results: We retrospectively collected 1288 older hip fractures patients with CHD. After excluding 214 patients who did not meet the criteria, 1074 patients were included in our research and we divided them into the training set and the validation set. In the training set, a total of 346 (42.8%) patients developing postoperative AHF. Through univariate and multivariate logistic regression analysis, we identified the risk factors for postoperative AHF and constructed a nomogram prediction model. The AUC of the prediction model is 0.778. The correction curve shows that the model has good consistency. The decision curve analysis shows that the model has good clinical practicality. Conclusion: There were 42.8% older patients combined with CHD develop postoperative AHF. Among them, fracture type, age, anemia at admission, combined with COPD, ASA ≥ 3, and preoperative waiting time > 3 days are risk factors for postoperative AHF. We constructed a nomogram prediction model that can effectively predict the risk of postoperative AHF in older hip fracture patients combined with CHD. [ABSTRACT FROM AUTHOR]

Background: The prognosis of elderly patients with acute myocardial infarction (AMI) is poor, and this study aimed to investigate the characteristics and predictors of preoperative AMI in elderly hip fracture patients and to propose a valid clinical prediction model.Methods: We collected clinical data of older hip fracture patients from January 2019 to December 2020. The data collected include demographic and clinical characteristics, underlying diseases and laboratory results. In AMI patients, we further collected type of myocardial infarctions, clinical symptoms, electrocardiogram (ECG), Killip class and diagnosis method. The prediction model was constructed by using Least absolute shrinkage and selection operator (LASSO) regression and multivariate logistic regression analyses. In addition, the constructed prediction model was transformed into a nomogram. The performance of the model was evaluated using the area under receiver operating characteristic curve (AUC), calibration curve, and decision curve analysis (DCA). Bootstrapping was used for validation.Results: There are 40 (4.2%) cases developed AMI in all 958 patients. There were 685 (71.5%) female patients and 273 (28.5%) male patients. Among 40 AMI patients, 38 (95.0%) had Type 2 myocardial infarction (T2MI) and 2 (5.0%) had Type 1 myocardial infarction (T1MI). The majority of these ECG were ST segment depression (57.5%). Most elderly AMI patients (67.5%) presented asymptomatic. Predictors for preoperative AMI were higher age (OR 2.386, 95% CI 1.126– 5.057), diabetes (OR 5.863, 95% CI 2.851– 12.058), Hb≤ 100 g/L (OR 3.976, 95% CI 1.478– 10.695), CRP≥ 40 mg/L (OR 6.998, 95% CI 2.875– 17.033), and ALB≤ 35 g/L (OR 2.166, 95% CI 1.049– 4.471). Good discrimination and calibration effect of the model was showed. Interval validation could still achieve the C-index value of 0.771. DCA demonstrated this nomogram has good clinical utility.Conclusion: This model has a good predictive effect on preoperative AMI in elderly patients with hip fracture, which can help to better plan clinical evaluation. [ABSTRACT FROM AUTHOR]

We previously identified a lipopeptide, EK1C4, by linking cholesterol to EK1, a pan-CoV fusion inhibitory peptide via a polyethylene glycol (PEG) linker, which showed potent pan-CoV fusion inhibitory activity. However, PEG can elicit antibodies to PEG in vivo, which will attenuate its antiviral activity. Therefore, we designed and synthesized a dePEGylated lipopeptide, EKL1C, by replacing the PEG linker in EK1C4 with a short peptide. Similar to EK1C4, EKL1C displayed potent inhibitory activity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and other coronaviruses. In this study, we found that EKL1C also exhibited broad-spectrum fusion inhibitory activity against human immunodeficiency virus type 1 (HIV-1) infection by interacting with the N-terminal heptad repeat 1 (HR1) of viral gp41 to block six-helix bundle (6-HB) formation. These results suggest that HR1 is a common target for the development of broad-spectrum viral fusion inhibitors and EKL1C has potential clinical application as a candidate therapeutic or preventive agent against infection by coronavirus, HIV-1, and possibly other class I enveloped viruses. [ABSTRACT FROM AUTHOR]

Artificial nanomotors show advantages over traditional nanomedicines in biomedical applications due to their active locomotion by converting various energy sources into mechanical force in situ. Currently, nanomotors are attracting wide attention in diagnosis and therapy towards clinical applications. In this perspective, we summarize recent developments of nanomotors in biomedical applications, including targeted drug delivery, biological barrier penetration, and diagnostics and cancer treatment. The development of nanomotors in biomedicine still faces considerable challenges and practical difficulties towards clinical use, which are discussed in detail. Finally, we propose potential solutions that may help the development of nanomotors towards advanced diagnostics and therapy. [ABSTRACT FROM AUTHOR]

Single crystalline BaMnSb2 is considered as a 3D Weyl semimetal with the 2D electronic structure containing Dirac cones from the Sb sheet. We report experimental investigation of low-temperature cleaved BaMnSb2 surfaces using scanning tunneling microscopy/spectroscopy and low energy electron diffraction. By natural cleavage, we find two terminations: one is Ba (above the orthorhombically distorted Sb sheet) and another Sb2 (at the surface of the Sb/Mn/Sb sandwich layer). Both terminations show the 2 × 1 surface reconstructions, with drastically different morphologies and electronic properties, however. The reconstructed structures, defect types and nature of the electronic structures of the two terminations are extensively studied. The quasiparticle interference (QPI) analysis is conducted at the energy range between −2 V and 2 V, although no interesting states are observed near the Fermi level, the surface-projected electronic band structures strongly depend on the surface termination above 1.6 V. The existence of defects can greatly modify the local density of states to create electronic phase separations on the surface in the order of tens of nm scale. Our observation on the atomic structures of the terminations and the corresponding electronic structures provides critical information towards an understanding of topological properties of BaMnSb2. [ABSTRACT FROM AUTHOR]

Purpose: Respiratory complication is one of the major challenges in the treatment of older adults with hip fractures. However, no study so far has investigated the effect of wearing medical masks on the prevention of perioperative respiratory complications in these patients. Patients and Methods: In this retrospective cohort study, 1016 consecutive patients aged ≥ 65 years with hip fractures were included and assigned to two groups: the control group and the observation group. The two groups received the same perioperative management modalities. In addition, patients in the observation group were asked to wear medical masks for protection. Data of patients' demographics, fracture type, surgical methods, comorbidities, the incidence of perioperative respiratory and other complications, and hospital outcomes were collected and compared between the two groups. Subgroup analyses were also performed stratified by fracture types. Results: A total of 1016 patients (292 females and 724 males) with a mean age of 79.4± 7.3 years were analyzed in the study, including 533 in the control group and 483 in the observation group. The overall incidence of perioperative respiratory complication, and the incidence of pulmonary infection, respiratory failure and arrhythmia in the observation group were significantly lower than the control group, especially in winter and spring. There was no difference in other complications, hospital length of stay, and total hospital costs. Further subgroup analyses showed that the incidence of heart failure and arrhythmia in the observation group was lower than that in the control group for patients with femoral neck fractures, which was different from patients with intertrochanteric fractures. Conclusion: The incidence of perioperative respiratory complications, including pulmonary infection and respiratory failure, could be reduced in older adults with hip fractures by strengthening personal protection, including wearing medical masks, especially in winter and spring. Wearing medical masks could also effectively reduce the incidence of perioperative heart failure and arrhythmia in femoral neck fracture patients and do not increase the incidence of other complications and the burden of hospitalization. [ABSTRACT FROM AUTHOR]

The electronic inhomogeneities in Co, Ni, and Cr doped BaFe2As2 single crystals are compared within three bulk property regions: a pure superconducting (SC) dome region, a coexisting SC and antiferromagnetic (AFM) region, and a non-SC region. Machine learning is utilized to categorize the inhomogeneous electronic states: in-gap, L-shape, and S-shape states. Although the relative percentages of the states vary in the three samples, the total volume fraction of the three electronic states is quite similar. This is coincident with the number of electrons (Ni0.04 and Co0.08) and holes (Cr0.04) doped into the compounds. The in-gap state is confirmed as a magnetic impurity state from the Co or Ni dopants, the L-shape state is identified as a spin density wave which competes with the SC phase, and the S-shape state is found to be another form of magnetic order which constructively cooperates with the SC phase, rather than competing with it. [ABSTRACT FROM AUTHOR]

The role of silver localized surface plasmons (LSPs) on the luminescence of a Si(111)-(7 × 7) surface has been investigated by scanning tunneling microscopy (STM) with a silver tip at 77 K. On a bare Si(111)-(7 × 7) surface, a characteristic peak at 1.85 eV dominates the STM-induced luminescence spectrum, although the luminescence intensity is extremely weak. Once Ag atoms are deposited onto the Si surface to form islands with a few atomic layers, it is found that the intensity of the characteristic peak from the Si surface underneath the Ag islands is significantly enhanced by about one order. In addition to the luminescence from the Si surface, light emission originating from the irradiation decay of the Ag plasmons is also detected. Such great enhancement of the luminescence from the Si surface is attributed to the strong coupling between the surface states of the Si and the LSPs of the Ag islands. [ABSTRACT FROM AUTHOR]

Purpose: Limited information exists on fall-related fractures in older adults with cerebrovascular disease. This study aimed to determine the characteristics of older adults with cerebrovascular disease who sustained fall-related fractures and identify the associated risk factors for perioperative complications. Patients and Methods: This was a cross-sectional study, which included patients with cerebrovascular disease who sustained fractures between Jan. 2017 and Dec. 2019. The collected data included demographics (age and gender), time and place of fracture occurrence, mechanism of injury, fracture location, type of cerebrovascular disease, complications, and comorbidities. Results: A total of 768 patients with 815 fractures were included; there were 253 males and 515 females, with an average age of 78.3 years. For either males or females, 80– 84 years was the most commonly involved age group. Most (61.0%) patients had their fractures occurring at home and most fractures (70.7%) occurred during the daytime. Most were hip fractures and limb weakness; instability-related falls were the most common cause of fracture, making a proportion of 34.5%. Patients who suffered falls were mainly combining ischemic cerebrovascular disease. Most (85.9%) patients presented with at least one comorbid disease and the perioperative complication rate was 76.9% in total cases. Age≥ 80 (OR: 1.772, 95% CI: 1.236– 2.540) and the number of comorbidities≥ 3 (OR: 1.606, 95% CI: 1.035– 2.494) were found independently associated with complications, while the type of cerebrovascular disease, fracture location, and comorbidities of prior fragility fracture and respiratory disease were not significantly correlated with complications. Conclusion: Our findings highlighted that more focus on improved physical function explored in intervention setting and the importance of primary home prevention measures seems justified in China and maybe other countries as well. It is the first study that presented the epidemiological characteristics of older adults with cerebrovascular disease who later experienced a fracture. [ABSTRACT FROM AUTHOR]

Background: Plasmid-mediated mechanisms of drug resistance accelerate the spread of polymyxin resistance, leaving clinicians with few or no antibacterial options for the treatment of infections caused by MDR bacteria, especially carbapenemase-producing strains.Objectives: To evaluate the associations among promoter sequence variation, mcr-1 expression, host factors and levels of colistin resistance and to propose antisense agents such as peptide nucleic acids (PNAs) targeting mcr-1 as a tool to restore colistin susceptibility through modulation of MCR-1 expression in Escherichia coli.Methods: A β-galactosidase assay was performed to study mcr-1 promoter activity. Quantitative real-time PCR and western blot assays were used to identify the expression level of MCR-1 in WT strains and transformants. Three PNAs targeting different regions of mcr-1 were designed and synthesized to determine whether they can effectively inhibit MCR-1 expression. MIC was measured to test colistin susceptibility in the presence or absence of PNA-1 in mcr-1-carrying E. coli.Results: Variation in the mcr-1 promoter sequence and host species affect promoter activity, MCR-1 expression levels and colistin MICs. One PNA targeting the ribosome-binding site fully inhibited the expression of mcr-1 at a concentration of 4 μM, resulting in significantly increased susceptibility to colistin. The MIC90 of colistin decreased from 8 to 2 mg/L (P < 0.05) in the presence of 4 μM PNA.Conclusions: These findings suggest that the antisense approach is a possible strategy to combat mcr-1-mediated resistance as well as other causes of emerging global resistance. [ABSTRACT FROM AUTHOR]