Anisotropy-induced phase transitions in an intrinsic half-Chern insulator Ni2I2.

One crucial target of research on spintronics is to achieve flexibly tunable and highly efficient spin-polarized electronic current. In this work, by using first-principles calculations and topological characterization theories, we propose an intrinsic half-Chern insulator (HCI) in a Ni2I2 monolayer, which possesses 100% spin-polarized topologically nontrivial edge states, distinct from ordinary Chern insulators. Its band gap is formed due to the lifting of the double degeneracy of non-Dirac bands composed of Ni dxz/dyz orbitals. The HCI becomes a half semiconductor (HS) or a combined state of a half metal (HM) and an HCI if biaxial strain is applied. The phase transition is found to be associated with the unique anisotropy of the bands, originating from the diverse orbital distributions and the opposite moving in energy of Ni dxy and dxz/dyz bands under the strain. Our findings demonstrate that the monolayer Ni2I2 is a unique Chern insulator with ideal spintronic properties, supporting versatile applications in spintronic devices with very high spin polarization and extremely low-power dissipation.

Trigonal multivalent polonium monolayers with intrinsic quantum spin Hall effects.

Two-dimensional (2D) topological insulators, a type of the extraordinary quantum electronic states, have attracted considerable interest due to their unique electronic properties and promising potential applications. Recently, the successful fabrication of 2D Te monolayers (i.e. tellurene) in experiments (Zhu et al., Phys Rev Lett 119:106101, 2017) has promoted researches on the group-VI monolayer materials. With first-principles calculations and tight-binding (TB) method, we investigate the structures and electronic states of 2D polonium (poloniumene), in which Po is a congener of Te. The poloniumene is found to have the tendency of forming a three-atomic-layer 1 T-MoS2-like structure (called trigonal poloniumene), namely, the central-layer Po atoms behave metal-like, while the two-outer-layer Po atoms are semiconductor-like. This unique multivalent behavior of the Po atoms is conducive to the structural stability of the monolayer, which is found to be an intrinsic quantum spin Hall insulator with a large band gap. The nontrivial topology originates from the [Formula: see text] band inversion, which can be understood based on a built TB model. The poloniumene with different congener elements doped is also explored. Our results provide a thorough understanding of structures and electronic states of 2D polonium-related materials.

Optimal glucose, HbA1c, glucose-HbA1c ratio and stress-hyperglycaemia ratio cut-off values for predicting 1-year mortality in diabetic and non-diabetic acute myocardial infarction patients.

BACKGROUND: Stress-induced hyperglycaemia at time of hospital admission has been linked to worse prognosis following acute myocardial infarction (AMI). In addition to glucose, other glucose-related indices, such as HbA1c, glucose-HbA1c ratio (GHR), and stress-hyperglycaemia ratio (SHR) are potential predictors of clinical outcomes following AMI. However, the optimal blood glucose, HbA1c, GHR, and SHR cut-off values for predicting adverse outcomes post-AMI are unknown. As such, we determined the optimal blood glucose, HbA1c, GHR, and SHR cut-off values for predicting 1-year all cause mortality in diabetic and non-diabetic ST-segment elevation myocardial infarction (STEMI) and non-ST-segment elevation myocardial infarction (NSTEMI) patients. METHODS: We undertook a national, registry-based study of patients with AMI from January 2008 to December 2015. We determined the optimal blood glucose, HbA1c, GHR, and SHR cut-off values using the Youden's formula for 1-year all-cause mortality. We subsequently analyzed the sensitivity, specificity, positive and negative predictive values of the cut-off values in the diabetic and non-diabetic subgroups, stratified by the type of AMI. RESULTS: There were 5841 STEMI and 4105 NSTEMI in the study. In STEMI patients, glucose, GHR, and SHR were independent predictors of 1-year all-cause mortality [glucose: OR 2.19 (95% CI 1.74-2.76); GHR: OR 2.28 (95% CI 1.80-2.89); SHR: OR 2.20 (95% CI 1.73-2.79)]. However, in NSTEMI patients, glucose and HbA1c were independently associated with 1-year all-cause mortality [glucose: OR 1.38 (95% CI 1.01-1.90); HbA1c: OR 2.11 (95% CI 1.15-3.88)]. In diabetic STEMI patients, SHR performed the best in terms of area-under-the-curve (AUC) analysis (glucose: AUC 63.3%, 95% CI 59.5-67.2; GHR 68.8% 95% CI 64.8-72.8; SHR: AUC 69.3%, 95% CI 65.4-73.2). However, in non-diabetic STEMI patients, glucose, GHR, and SHR performed equally well (glucose: AUC 72.0%, 95% CI 67.7-76.3; GHR 71.9% 95% CI 67.7-76.2; SHR: AUC 71.7%, 95% CI 67.4-76.0). In NSTEMI patients, glucose performed better than HbA1c for both diabetic and non-diabetic patients in AUC analysis (For diabetic, glucose: AUC 52.8%, 95% CI 48.1-57.6; HbA1c: AUC 42.5%, 95% CI 37.6-47. For non-diabetic, glucose: AUC 62.0%, 95% CI 54.1-70.0; HbA1c: AUC 51.1%, 95% CI 43.3-58.9). The optimal cut-off values for glucose, GHR, and SHR in STEMI patients were 15.0 mmol/L, 2.11, and 1.68 for diabetic and 10.6 mmol/L, 1.72, and 1.51 for non-diabetic patients respectively. For NSTEMI patients, the optimal glucose values were 10.7 mmol/L for diabetic and 8.1 mmol/L for non-diabetic patients. CONCLUSIONS: SHR was the most consistent independent predictor of 1-year all-cause mortality in both diabetic and non-diabetic STEMI, whereas glucose was the best predictor in NSTEMI patients.

Full Respiration Rate Monitoring Exploiting Doppler Information with Commodity Wi-Fi Devices.

Respiration rate is an essential indicator of vital signs, which can demonstrate the physiological condition of the human body and provide clues to some diseases. Commercial Wi-Fi devices can provide a non-invasive, cost-effective and long-term respiration rate-monitoring scheme for home scenarios. However, previous studies show that the breathing depth and location may affect the detectability of respiratory signals. In this study, we leverage the variation of the Doppler spectral energy extracted from the channel state information (CSI) collected by Wi-Fi devices to track the chest displacement induced by respiration. First, the random phase is eliminated by phase-fitting method to obtain the complex CSI containing the Doppler shift. Then, the multipath decomposition of CSI is carried out to obtain the channel impulse response, which eliminates the interference phase of the time delay and retains the Doppler shift. The dynamic path units are also separate from the multipath, which overcomes the indoor multipath effect. Finally, we conduct a time-frequency analysis to dynamic units to accumulate Doppler spectral energy. Based on these ideas, we design a complete respiration rate-monitoring system to obtain the respiration rate by using the consistency between the Doppler energy change period and the respiratory cycle. We evaluate our system through extensive experiments in several typical home environments filled with multipath. Experimental results show that the errors of the three scenarios are approximate, the maximum error is less than 0.7 bpm, and the average errors are approximately 0.15 bpm. This result indicates that our scheme can achieve high precision respiration monitoring and has good anti-multipath ability compared with existing methods.

Various half-metallic nodal loops in organic Cr2N6C3 monolayers.

Topological nodal-line semimetals, as a type of exotic quantum electronic state, have drawn considerable research interest recently. In this work, we propose a new two-dimensional covalent-organic Cr2N6C3 monolayer (ML) material, which has a combined honeycomb and effective Kagome lattice and has various half-metallic nodal loops (HMNLs). First-principles calculations show that the Cr2N6C3 ML is dynamically and thermally stable and has an out-of-plane ferromagnetic order. Remarkably, various nodal loops, including types I-III, are found coexisting in the material, all of which are rare half-metallic states. The obtained HMNLs, simultaneously possessing the merits of spintronics and semimetals, are robust against spin-orbit coupling and biaxial strain. A topological phase transition, characterized by loop-winding indexes, can be induced in the ML by applying uniaxial strain. Tight-binding model calculations show that the obtained HMNLs originate primarily from the band inversion between Cr dx2-y2/xy and N pz orbitals, accommodated on the honeycomb and Kagome sublattices, respectively. The various predicted HMNLs and topological behaviors mean that the Cr2N6C3 MLs have promisingly versatile applications in future low-power-consuming spintronics and electronics.

Abundant topological phases in hydrogenated group-IV binary alloy compounds.

Based on the widely studied two-dimensional layered materials, new materials with unique properties can be acquired by stacking the layered materials with different styles. By using density-functional calculations and symmetry analysis, we here present a route to produce abundant topologically nontrivial electronic states in three-dimensional compounds made of stacked monolayer hydrogenated group-IV binary alloys. Triply degenerate point (TDP) semimetals and Dirac semimetals are found in the hydrogenated SnPb compounds with different stacking configurations. The TDP semimetal is characterized by two sets of near-Dirac TDPs, stemming from the inversion of the s (p z ) and p x,y bands from the Pb (and also Sn) atoms and protected by a C 3v double point group symmetry. Type-I and type-II states, and one essential Dirac semimetal state, coexist in a hydrogenated SnPb compound. Hourglass surface states are also observed in this case. For the hydrogenated GeSn and GePb compounds, normal insulators and weak topological insulators (and also Dirac semimetals) are obtained, respectively. The topological nature of the states is identified by calculations of topological indexes as well as surface states. With these extremely rich topological phases, the studied compounds offer an ideal material platform for realizing topological semimetals and insulators in experiments.

Determination of Risk Factors and Establishment of a Prediction Model for Immediate Technical Failure during Endovascular Treatment of Femoropopliteal Occlusive Disease.

BACKGROUND: For long femoropopliteal occlusive lesions, the immediate technical failure (ITF) of endovascular treatment (EVT) is relatively high. Therefore, this study aims to reveal risk factors and establish a prediction model of ITF of EVT in femoropopliteal occlusive disease (FPOD) patients based on preoperative clinical date that may be helpful to the clinical procedures. METHODS: A retrospective analysis of 1,563 FPOD patients who underwent above-the-knee EVT was undertaken. Univariate analysis with chi-squared test was used to screen risk factors from preoperative clinical data. Multivariable analysis with logistic regression was used to generate a model for predicting the ITF rate of EVT, which was evaluated through the receiver operating characteristic curve and another independent cohort of 242 FPOD patients. RESULTS: Risk factors for ITF during EVT in FPOD included age (>80 years, X1), the absence of diabetes mellitus (X2), low-density lipoprotein (>160 mg/dL, X3), lesion calcification (X4), lesion length (>20 cm, X5), ostial occlusion of superficial femoral artery (SFA) (X6), and SFA lesion involving the popliteal artery (X7). A logistic regression model was established based on the equation: -6.504 + 1.236X1 + 0.945X2 + 1.406X3 + 1.136X4 + 1.059X5 + 2.307X6 + 2.194X7. Scores were given to risk factors as follows: X1 (yes = 12, no = 0), X2 (yes = 9, no = 0), X3 (yes = 14, no = 0), X4 (yes = 11, no = 0), X5 (yes = 11, no = 0), X6 (yes = 23, no = 0), and X7 (yes = 22, no = 0). We determined that the optimal comprehensive score for predicting EVT failure was 39, with a sensitivity of 0.847 and a specificity of 0.8. Among these 242 peripheral arterial disease patients, 12 of 14 patients who had failed EVT had a comprehensive score of >39. CONCLUSIONS: We identified a number of risk factors of ITF during the above-the-knee EVT and established a prediction model that may be used for guidance in clinical practice.

Strain Effect on the Electronic and Optical Properties of CdSe Nanowires.

First-principles density functional theory (DFT) simulations were carried out to study the strain dependence on the electronic and optical properties of cadmium selenide (CdSe) nanowires (NWs). The band structures, effective masses of electron and holes, dielectric properties, and other optical properties (such as extinction coefficient, optical reflectivity, and absorption coefficient) were calculated under both compressive and tensile uniaxial strains. Size-dependence was also discussed by comparing results among CdSe wires with various diameters. Simulation results show that an interesting band-switch behavior occurs at the valence bands regardless of size. The cause and the consequences of such band-switch behavior were also studied. Further strain dependence on corresponding electronic and optical properties were examined as well. Our results provide insights to possible mechanical tuning via strain on the electronic and optical properties of CdSe NWs.

Laparoscopic surgery assisted by colonoscopy for a submucosal cecal fecalith presenting as acute appendicitis: A case report.

RATIONALE: A cecal submucosal fecalith is extremely rare and is likely to be misdiagnosed as appendicitis with an incarcerated fecalith. PATIENT CONCERNS: This review presents the case of a female patient complaining of recurrent abdominal pain in the right lower quadrant, similar to the clinical symptoms of appendicitis. Physical examination revealed an abdominal tenderness in the right lower quadrant without rebound tenderness or muscular tension. An ultrasound examination found a mass located in the right lower abdomen. Computed tomography showed a high-density shadow in the cecal cavity. DIAGNOSES: A fecalith was detected in the submucosal cecal wall. The postoperative pathologic examination showed that the fecalith was located in the submucosa. INTERVENTIONS: A partial cecal excision was performed under laparoscopic surgery assisted by colonoscopy. OUTCOMES: The patient was discharged 1 week after surgery without postoperative complications. LESSONS: Fecaliths should be considered in the differential diagnosis of submucosal occupying lesions of the cecum.

Oxygen consumption, substrate oxidation, and blood pressure following sprint interval exercise.

UNLABELLED: This study examined the acute effect of sprint interval exercise (SIE) on postexercise oxygen consumption, substrate oxidation, and blood pressure. The participants were 10 healthy males aged 21-27 years. Following overnight fasts, each participant undertook 2 trials in a random balanced order: (i) four 30-s bouts of SIE on a cycle ergometer, separated by 4.5 min of recovery, and (ii) resting (control) in the laboratory for an equivalent period. Time-matched measurements of oxygen consumption, respiratory exchange ratio, and blood pressure were made for 2 h into recovery. Total 2-h oxygen consumption was significantly higher in the SIE than in the control trial (mean ± SD: CONTROL: 31.9 ± 6.7 L vs Exercise: 45.5 ± 6.8 L, p < 0.001). The rate of fat oxidation was 75% higher 2 h after the exercise trial compared with the control trial ( CONTROL: 0.08 ± 0.05 g·min(-1) vs Exercise: 0.14 ± 0.06 g·min(-1), p = 0.035). Systolic blood pressure ( CONTROL: 117 ± 8 mm Hg vs Exercise: 109 ± 8 mm Hg, p < 0.05) and diastolic blood pressure ( CONTROL: 84 ± 6 mm Hg vs Exercise: 77 ± 5 mm Hg, p < 0.05) were significantly lower 2 h after the exercise trial compared with the control trial. These data showed a 42% increase in oxygen consumption (∼13.6 L) over 2 h after a single bout of SIE. Moreover, the rate of fat oxidation increased by 75%, whereas blood pressure was reduced by ∼8 mm Hg 2 h after SIE. Whether these acute benefits of SIE can translate into long-term changes in body composition and an improvement in vascular health needs investigation.

[Mitochondrial calcium uniporter participates in TNF-alpha induced cardioprotection in isolated rat hearts subjected to ischemia/reperfusion].

AIM: To investigate whether mitochondrial calcium uniporter participates in the cardioprotection of tumor necrosis factor alpha (TNFalpha) pretreatment in isolated rat hearts subjected to ischemia/reperfusion. METHODS: Isolated perfused rat hearts were subjected to 30 min regional ischemia (occlusion of left anterior descending artery) and 120 min reperfusion. The infarct size, coronary flow (CF) and lactate dehydrogenase (LDH) release during reperfusion were measured. The mitochondria of the heart were isolated and suspended in the swelling buffer for measurement of absorbance at 520 nm. RESULTS: Pretreatment with TNFa at 10 U/ml for 7 min followed by 10 min washout reduced the infarct size and LDH release, and improved the recovery of CF during reperfusion. Administration of spermine (20 micromol/L), an opener of mitochondrial calcium uniporter, for 10 min during early reperfusion attenuated the reduction of infarct size and LDH release, and improvement of CF induced by TNFalpha. In isolated mitochondria of the heart pretreated with TNFalpha, the absorbance at 520 nm decreased less than that of mitochondria without TNFalpha pretreatment. Administration of spermine (50 micromol/L) attenuated the change of the absorbance induced by TNFalpha. CONCLUSION: The findings indicate that TNFalpha protects myocardium against ischemia/reperfusion injury via inhibiting mitochondrial calcium uniporter opening as well as mitochondrial permeability transition pore opening.

Mitochondrial calcium uniporter participates in TNF-alpha induced cardioprotection in isolated rat hearts subjected to ischemia/reperfusion / 中国应用生理学杂志

<p><b>AIM</b>To investigate whether mitochondrial calcium uniporter participates in the cardioprotection of tumor necrosis factor alpha (TNFalpha) pretreatment in isolated rat hearts subjected to ischemia/reperfusion.</p><p><b>METHODS</b>Isolated perfused rat hearts were subjected to 30 min regional ischemia (occlusion of left anterior descending artery) and 120 min reperfusion. The infarct size, coronary flow (CF) and lactate dehydrogenase (LDH) release during reperfusion were measured. The mitochondria of the heart were isolated and suspended in the swelling buffer for measurement of absorbance at 520 nm.</p><p><b>RESULTS</b>Pretreatment with TNFa at 10 U/ml for 7 min followed by 10 min washout reduced the infarct size and LDH release, and improved the recovery of CF during reperfusion. Administration of spermine (20 micromol/L), an opener of mitochondrial calcium uniporter, for 10 min during early reperfusion attenuated the reduction of infarct size and LDH release, and improvement of CF induced by TNFalpha. In isolated mitochondria of the heart pretreated with TNFalpha, the absorbance at 520 nm decreased less than that of mitochondria without TNFalpha pretreatment. Administration of spermine (50 micromol/L) attenuated the change of the absorbance induced by TNFalpha.</p><p><b>CONCLUSION</b>The findings indicate that TNFalpha protects myocardium against ischemia/reperfusion injury via inhibiting mitochondrial calcium uniporter opening as well as mitochondrial permeability transition pore opening.</p>