Plantago consumption significantly reduces total cholesterol and low-density lipoprotein cholesterol in adults: A systematic review and meta-analysis.

Plantago is rich in soluble fiber, known for its beneficial health effects. Given this, we hypothesized that Plantago consumption might positively influence blood lipid in adults. Researchers have conducted numerous randomized controlled trials (RCTs), revealing the impacts of Plantago consumption on various blood lipid parameters. However, findings regarding specific blood lipid parameters have shown variability. This study aimed to comprehensively assess the effect of Plantago consumption on blood lipid parameters. Eligible studies evaluating the effects of Plantago consumption on blood lipid were searched in 5 electronic databases published up to August 2023. Analysis used a random effects model to determine weighted mean difference and 95% confidence intervals. In total, 29 RCTs including 2769 participants were included. Compared with the control group, Plantago consumption significantly reduced total cholesterol (TC) by 0.28 mmol/L and low-density lipoprotein cholesterol (LDL-C) by 0.35 mmol/L, correlating to an estimated 7% decrease in cardiovascular event risk. Conversely, no substantial effects were observed on high-density lipoprotein cholesterol or triglycerides. Subgroup analyses of 29 RCTs revealed that TC concentrations were significantly lowered in studies that included male participants, those who were healthy, or had lipid disorders. Additionally, TC and LDL-C were significantly lower in participants consuming Plantago husk or psyllium, and soluble fiber intake was specifically effective in lowering TC, LDL-C, and triglycerides. In conclusion, Plantago consumption can significantly lower TC and LDL-C concentrations. The findings will provide crucial insights into the potential of Plantago in dietary strategies for blood lipid management.

Topological electronic structure and spin texture of quasi-one-dimensional higher-order topological insulator Bi4Br4.

The notion of topological insulators (TIs), characterized by an insulating bulk and conducting topological surface states, can be extended to higher-order topological insulators (HOTIs) hosting gapless modes localized at the boundaries of two or more dimensions lower than the insulating bulk. In this work, by performing high-resolution angle-resolved photoemission spectroscopy (ARPES) measurements with submicron spatial and spin resolution, we systematically investigate the electronic structure and spin texture of quasi-one-dimensional (1D) HOTI candidate Bi4Br4. In contrast to the bulk-state-dominant spectra on the (001) surface, we observe gapped surface states on the (100) surface, whose dispersion and spin-polarization agree well with our ab-initio calculations. Moreover, we reveal in-gap states connecting the surface valence and conduction bands, which is a signature of the hinge states inside the (100) surface gap. Our findings provide compelling evidence for the HOTI phase of Bi4Br4. The identification of the higher-order topological phase promises applications based on 1D spin-momentum locked current in electronic and spintronic devices.

Depletion of lncRNA MEG3 Ameliorates Imatinib-Induced Injury of Cardiomyocytes via Regulating miR-129-5p/HMGB1 Axis.

Imatinib is a classical targeted drug to treat chronic myeloid leukemia (CML). However, it shows cardiotoxicity, which limits its clinical application. Long noncoding RNA (lncRNA) maternally expressed gene 3 (MEG3) shows proapoptotic properties in human cells. This study is performed to investigate whether targeting MEG3 can attenuate imatinib-mediated cardiotoxicity to cardiomyocytes. In this work, H9c2 cells were divided into four groups: control group, hypoxia group, hypoxia + imatinib, and hypoxia + imatinib + MEG3 knockdown group. MEG3 and microRNA-129-5p (miR-129-5p) expression levels were detected by the quantitative real-time PCR (qRT-PCR). The viability and apoptosis of H9c2 cells were then evaluated by cell counting kit-8 (CCK-8), flow cytometry, and TUNEL assays. The targeting relationships between MEG3 and miR-129-5p, between miR-129-5p and high-mobility group box 1 (HMBG1), were validated by dual-luciferase reporter assay and RNA Immunoprecipitation (RIP) assay. The protein expression level of HMGB1 was detected by western blot. It was revealed that, Imatinib-inhibited cell viability and aggravated the apoptosis of H9c2 cells cultured in hypoxic condition, and MEG3 knockdown significantly counteracted this effect. MiR-129-5p was a downstream target of MEG3 and it directly targeted HMGB1, and knockdown of MEG3 inhibited HMGB1 expression in H9c2 cells. In conclusion, targeting MEG3 ameliorates imatinib-induced injury of cardiomyocytes via regulating miR-129-5p/HMGB1 axis.

3D slicer combined with neuroendoscope in treatment of a distal segment aneurysm of the anterior choroidal artery complicated intraventricular hemorrhage: A case report and literature review.

Introduction: Pure ventricular hemorrhage is often secondary to Moyamoya disease, rarely caused by rupture of ventricular aneurysm. The surgical treatment of the latter is very challenging. 3D Slicer reconstruction technology can accurately locate small intracranial lesions and combined with minimally invasive surgery with transcranial neuroendoscope is a new attempt to treat the above diseases. Case presentation: We report a case of pure intraventricular hemorrhage secondary to rupture of a distal segment aneurysm of the anterior choroidal artery. Brain computed tomography (CT) before admission showed pure ventricular hemorrhage, and brain CT angiography (CTA) before operation showed a distal segment aneurysm of the anterior choroidal artery. We used 3D Slicer reconstruction and precise location of the focus before the operation and used the minimally invasive surgery technique with transcranial neuroendoscope to completely remove the hematoma in the ventricle, and found the responsible aneurysm located in the ventricle. Conclusion: Pure intraventricular hemorrhage requires vigilance against the distal segment aneurysm of the anterior choroidal artery. At present, conventional microscopic craniotomy and intravascular interventional therapy have limitations, and 3D Slicer reconstruction and precise positioning technology combined with transcranial neuroendoscope minimally invasive surgery may be a good choice.

Dominant Two-Dimensional Electron-Phonon Interactions in the Bulk Dirac Semimetal Na3Bi.

Bulk Dirac semimetals (DSMs) exhibit unconventional transport properties and phase transitions due to their peculiar low-energy band structure, yet the electronic interactions governing nonequilibrium phenomena in DSMs are not fully understood. Here we show that electron-phonon (e-ph) interactions in a prototypical bulk DSM, Na3Bi, are predominantly two-dimensional (2D). Our first-principles calculations reveal a 2D optical phonon with strong e-ph interactions associated with in-plane vibrations of Na atoms. We show that this 2D mode governs e-ph scattering and charge transport in Na3Bi and induces a dynamical phase transition to a Weyl semimetal. Our work advances the quantitative analysis of electron interactions in Na3Bi and reveals a dominant low-dimensional interaction in a bulk Dirac semimetal.

Optical bulk-boundary dichotomy in a quantum spin Hall insulator.

The bulk-boundary correspondence is a critical concept in topological quantum materials. For instance, a quantum spin Hall insulator features a bulk insulating gap with gapless helical boundary states protected by the underlying Z2 topology. However, the bulk-boundary dichotomy and distinction are rarely explored in optical experiments, which can provide unique information about topological charge carriers beyond transport and electronic spectroscopy techniques. Here, we utilize mid-infrared absorption micro-spectroscopy and pump-probe micro-spectroscopy to elucidate the bulk-boundary optical responses of Bi4Br4, a recently discovered room-temperature quantum spin Hall insulator. Benefiting from the low energy of infrared photons and the high spatial resolution, we unambiguously resolve a strong absorption from the boundary states while the bulk absorption is suppressed by its insulating gap. Moreover, the boundary absorption exhibits strong polarization anisotropy, consistent with the one-dimensional nature of the topological boundary states. Our infrared pump-probe microscopy further measures a substantially increased carrier lifetime for the boundary states, which reaches one nanosecond scale. The nanosecond lifetime is about one to two orders longer than that of most topological materials and can be attributed to the linear dispersion nature of the helical boundary states. Our findings demonstrate the optical bulk-boundary dichotomy in a topological material and provide a proof-of-principal methodology for studying topological optoelectronics.

Ab initio real-time quantum dynamics of charge carriers in momentum space.

Application of the non-adiabatic molecular dynamics (NAMD) approach is limited to studying carrier dynamics in the momentum space, as a supercell is required to sample the phonon excitation and electron-phonon (e-ph) interaction at different momenta in a molecular dynamics simulation. Here we develop an ab initio approach for the real-time charge carrier quantum dynamics in the momentum space (NAMD_k) by directly introducing e-ph coupling into the Hamiltonian based on the harmonic approximation. The NAMD_k approach maintains the zero-point energy and includes memory effects of carrier dynamics. The application of NAMD_k to the hot carrier dynamics in graphene reveals the phonon-specific relaxation mechanism. An energy threshold of 0.2 eV-defined by two optical phonon modes-separates the hot electron relaxation into fast and slow regions with lifetimes of pico- and nanoseconds, respectively. The NAMD_k approach provides an effective tool to understand real-time carrier dynamics in the momentum space for different materials.

Predicting Phonon-Induced Spin Decoherence from First Principles: Colossal Spin Renormalization in Condensed Matter.

Developing a microscopic understanding of spin decoherence is essential to advancing quantum technologies. Electron spin decoherence due to atomic vibrations (phonons) plays a special role as it sets an intrinsic limit to the performance of spin-based quantum devices. Two main sources of phonon-induced spin decoherence-the Elliott-Yafet and Dyakonov-Perel mechanisms-have distinct physical origins and theoretical treatments. Here, we show calculations that unify their modeling and enable accurate predictions of spin relaxation and precession in semiconductors. We compute the phonon-dressed vertex of the spin-spin correlation function with a treatment analogous to the calculation of the anomalous electron magnetic moment in QED. We find that the vertex correction provides a giant renormalization of the electron spin dynamics in solids, greater by many orders of magnitude than the corresponding correction from photons in vacuum. Our Letter demonstrates a general approach for quantitative analysis of spin decoherence in materials, advancing the quest for spin-based quantum technologies.

Two-dimensional electronic structure for high thermoelectric performance in halide perovskite Cs2Au(I)Au(III)I6.

Pb- or Sn-based halide perovskites usually exhibit poor thermoelectric performance, arising from their low electrical conductivity or oxidation state instability. It is highly desired to search for new halide perovskites with good thermoelectric properties. In this work, the thermally stable mixed-valence halide perovskite Cs2Au(I)Au(III)I6 is revealed to be a highly promising thermoelectric material with high in-plane power factor and ultralow lattice thermal conductivity using first-principles calculations. The high in-plane power factor is achieved due to the novel two-dimensional electronic structure near the Fermi level driven by the weak interaction between AuI-5d and I-p orbitals. In addition, the small group velocities and short phonon lifetimes give rise to ultralow lattice thermal conductivity in Cs2Au(I)Au(III)I6. These excellent electronic and thermal properties lead to a high ZT value, which is close to 1 at 300 K and ∼4 at 800 K. Our results suggest that the 2D electronic structure from the weak interaction between d and p crystal orbitals is a promising route to design high-efficiency halide double perovskite thermoelectric materials.

Reversible Light-Controlled CO Adsorption via Tuning π-Complexation of Cu+ Sites in Azobenzene-Decorated Metal-Organic Frameworks.

Light-responsive adsorbents capture significant attention due to their tailorable performance upon light irradiation. The modulation of such adsorbents is mainly based on weak (physical) interactions caused by steric hindrance while tuning strong interaction with target adsorbates is scarce. Here we report smart π-complexation adsorbents, which can adjust the π-complexation of active sites via light irradiation. A typical metal-organic framework, MIL-101-NH2 , was decorated with azobenzene motifs, and Cu+ as π-complexation active sites were introduced subsequently. The reversible light-induced isomerization of azobenzene regulates the surface electrostatic potentials around Cu+ from -0.038 to 0.008 eV, causing shielding and exposure effects. The alteration of CO uptake is achieved up to 54 % via changing light, while that on MIL-101-NH2 is negligible. This study provides a clue for designing target-specific smart materials to meet the practical stimuli-responsive adsorption demands.

Shenmai Injection Attenuates Myocardial Ischemia/Reperfusion Injury by Targeting Nrf2/GPX4 Signalling-Mediated Ferroptosis.

OBJECTIVE: To examine the effect of Shenmai Injection (SMJ) on ferroptosis during myocardial ischemia reperfusion (I/R) injury in rats and the underlying mechanism. METHODS: A total of 120 SPF-grade adult male SD rats, weighing 220-250 g were randomly divided into different groups according to a random number table. Myocardial I/R model was established by occluding the left anterior descending artery for 30 min followed by 120 min of reperfusion. SMJ was injected intraperitoneally at the onset of 120 min of reperfusion, and erastin (an agonist of ferroptosis), ferrostatin-1 (Fer-1, an inhibitor of ferroptosis) and ML385 (an inhibitor of nuclear factor erythroid-2 related factor 2 (Nrf2)) were administered intraperitoneally separately 30 min before myocardial ischemia as different pretreatments. Cardiac function before ischemia, after ischemia and after reperfusion was analysed. Pathological changes in the myocardium and the ultrastructure of cardiomyocytes were observed, and the myocardial infarction area was measured. Additionally, the concentration of Fe2+ in heart tissues and the levels of creatine kinase-MB (CK-MB), troponin I (cTnl), malondialdehyde (MDA) and superoxide dismutase (SOD) in serum were measured using assay kits, and the expressions of Nrf2, glutathione peroxidase 4 (GPX4) and acyl-CoA synthetase long-chain family member 4 (ACSL4) were examined by Western blot. RESULTS: Compared with the sham group, I/R significantly injured heart tissues, as evidenced by the disordered, ruptured and oedematous myocardial fibres; the increases in infarct size, serum CK-MB, cTnI and MDA levels, and myocardial Fe2+ concentrations; and the decreases in SOD activity (P<0.05). These results were accompanied by ultrastructural alterations to the mitochondria, increased expression of ACSL4 and inhibited the activation of Nrf2/GPX4 signalling (P<0.05). Compared with I/R group, pretreatment with 9 mL/kg SMJ and 2 mg/kg Fer-1 significantly reduced myocardial I/R injury, Fe2+ concentrations and ACSL4 expression and attenuated mitochondrial impairment, while 14 mg/kg erastin exacerbated myocardial I/R injury (P<0.05). In addition, cardioprotection provided by 9 mL/kg SMJ was completely reversed by ML385, as evidenced by the increased myocardial infarct size, CK-MB, cTnI, MDA and Fe2+ concentrations, and the decreased SOD activity (P<0.05). CONCLUSIONS: Ferroptosis is involved in myocardial I/R injury. Pretreatment with SMJ alleviated myocardial I/R injury by activating Nrf2/GPX4 signalling-mediated ferroptosis, thereby providing a strategy for the prevention and treatment of ischemic heart diseases.

Effects of Different Anesthetics on Perioperative Organ Protection and Postoperative Cognitive Function in Patients Undergoing Cardiac Valve Replacement with Cardiopulmonary Bypass.

In this paper, we have carried out an experimental study to investigate the effects of different anesthetics on perioperative organ protection and postoperative cognitive function in patients undergoing cardiac valve replacement with cardiopulmonary bypass. To realize this idea, a total of 90 patients with single valve replacement under general anesthesia and hypothermic cardiopulmonary bypass from January 2020 to October 2021 were enrolled. These patients were assigned into three groups, with 30 cases in each group by the digital table method. Group A was anesthetized with sufentanil combined with dexmedetomidine. Group B was anesthetized with sufentanil combined with etomidate. Group C was anesthetized with sufentanil combined with propofol. Perioperative organ protection and postoperative cognitive function of the three groups were compared. At T 0 time point, there was no significant difference in blood WBC, blood N, and CRP among groups A, B, and C (P > 0.05); At T 4 and T 5 time points, the indexes of blood WBC, blood N, and CRP in groups A, B, and C were higher compared to the T 0 time point. At T 4 and T 5 time points, the indexes of blood WBC, blood N, and CRP in group A were significantly lower compared to group B and group C. Before treatment, there was no significant difference in ALT and AST among groups A, B, and C (P > 0.05). After treatment, the indexes of ALT and AST in group A were significantly lower compared to group B and group C at T 4 and T 5 time points (P < 0.05). Before treatment, there was no significant difference in urea and creatinine among groups A, B, and C (P > 0.05). After treatment, the urea and creatinine indexes of group A were significantly lower compared to group B and group C at T 4 and T 5 time points (P < 0.05). Before treatment, there was no significant difference in CK-MB and CTnl among groups A, B, and C (P > 0.05); After treatment, the indexes of CK-MB and CTnl in group A were significantly lower compared to group B and group C at T 4 and T 5 time points (P < 0.05). Before treatment, there was no significant difference in MOCA scores among groups A, B, and C (P > 0.05). After treatment, the MOCA scores of group A were significantly higher compared to group B and group C at T 5 and T 6 time points (P < 0.05). Sufentanil combined with dexmedetomidine for heart valve replacement under cardiopulmonary bypass can reduce the dosage of anesthetics during the operation and have a certain perioperative protective effect on important organs such as the heart, lung, liver, and kidney, which may be related to reducing intraoperative hemodynamic fluctuations and inhibiting inflammatory stress response.

Observation of Topological Edge States on α-Bi4Br4 Nanowires Grown on TiSe2 Substrates.

A time-reversal invariant two-dimensional (2D) topological insulator (TI) is characterized by the gapless helical edge states propagating along the perimeter of the system. However, the small band gap in the 2D TIs discovered so far hinders their applications. Recently, we predicted that single-layer Bi4Br4 is a 2D TI with a remarkable band gap and that α-Bi4Br4 crystals can host topological edge states at the step edges. Here we report the growth of α-Bi4Br4 nanowires with (102)-oriented top surfaces on the TiSe2 substrates and the direct observation of the predicted topological edge states at the step edges of the nanowires using scanning tunneling microscopy. The coupling between the edge states leads to the formation of surface states at the (102) top surfaces of the nanowires. Our work demonstrates the existence of topological edge states in α-Bi4Br4 and paves the way for developing α-Bi4Br4-based devices for a high-temperature quantum spin Hall effect.

Ab Initio Electron-Phonon Interactions in Correlated Electron Systems.

Electron-phonon (e-ph) interactions are pervasive in condensed matter, governing phenomena such as transport, superconductivity, charge-density waves, polarons, and metal-insulator transitions. First-principles approaches enable accurate calculations of e-ph interactions in a wide range of solids. However, they remain an open challenge in correlated electron systems (CES), where density functional theory often fails to describe the ground state. Therefore reliable e-ph calculations remain out of reach for many transition metal oxides, high-temperature superconductors, Mott insulators, planetary materials, and multiferroics. Here we show first-principles calculations of e-ph interactions in CES, using the framework of Hubbard-corrected density functional theory (DFT+U) and its linear response extension (DFPT+U), which can describe the electronic structure and lattice dynamics of many CES. We showcase the accuracy of this approach for a prototypical Mott system, CoO, carrying out a detailed investigation of its e-ph interactions and electron spectral functions. While standard DFPT gives unphysically divergent and short-ranged e-ph interactions, DFPT+U is shown to remove the divergences and properly account for the long-range Fröhlich interaction, allowing us to model polaron effects in a Mott insulator. Our work establishes a broadly applicable and affordable approach for quantitative studies of e-ph interactions in CES, a novel theoretical tool to interpret experiments in this broad class of materials.

Controllable Microporous Framework Isomerism within Continuous Mesoporous Channels: Hierarchically Porous Structure for Capture of Bulky Molecules.

To date, some attempts have been made to synthesize hierarchically porous metal-organic frameworks (HPMOFs), and in most cases, mesopores are formed in microporous frameworks. However, mass transfer and diffusion are still limited in such HPMOFs since micropores connect mesopores and mesopores are noncontinuous. Here, we fabricate a new hierarchical structure through the formation of microporous MOFs within continuous mesoporous channels. Confined space in the as-prepared mesoporous silica-containing template was used to prepare well-dispersed metal precursor of ZnO. The strategy of ligand vapor-induced crystallization was then designed to construct MOFs inside mesoporous channels, in which vapored ligand at elevated temperature diffuses and reacts with metal precursor. Our results indicate that framework isomerism is controllable by adjusting the crystallization conditions. In comparison to their microporous and mesoporous counterparts, the hierarchically porous materials show obviously enhanced adsorption performance on a series of bulky molecules including dye, enzyme, and metal-organic polyhedron.

Efficacy and safety of different doses of tenecteplase for the treatment of acute ischemic stroke: A protocol for a systematic review and network meta-analysis.

BACKGROUND: Acute ischemic stroke (AIS) has become the major reason of causing death around the world. As a newer generation fibrinolytic agent, the potential of tenecteplase in treating AIS has been determined in clinical studies and meta-analysis. However, various doses have been prescribed for tenecteplase in clinical practice, and the optimal dose is not yet clear. METHODS: We will perform a systematic search to capture all potential randomized controlled trials (RCTs) of persons with confirmed AIS who were instructed to administer tenecteplase that report at least one outcome in PubMed, Embase, and the Cochrane Library. Two reviewers will independently check the titles, abstracts, and full-texts, extracting data, assessing the risk of bias and evaluating the certainty of evidence. We will use a random-effect model based on the Bayesian framework to completely direct and network meta-analyses. We will also test the robustness of all pooled results through conducting subgroup analyses according to the following criteria: DISCUSSION:: Our systematic review and network meta-analysis will generate several valuable findings and have several strengths including:We therefore believe that findings from this network meta-analysis will benefit future study design and improve evidence-based treatment of AIS. ETHICS AND DISSEMINATION: We will disseminate the results from the present study through submitting it to conferences or peer-reviewed journal. PROTOCOL REGISTRY: The protocol of our systematic review and network meta-analysis was registered in International Plateform of Registered Systematic Review and Meta-Analysis Protocols (INPLASY) platform with an approval number of INPLASY2020100086 (https://inplasy.com/inplasy-2020-10-0086/). Moreover, this protocol was funded through a protocol registry.

Piezoelectric Electron-Phonon Interaction from Ab Initio Dynamical Quadrupoles: Impact on Charge Transport in Wurtzite GaN.

First-principles calculations of e-ph interactions are becoming a pillar of electronic structure theory. However, the current approach is incomplete. The piezoelectric (PE) e-ph interaction, a long-range scattering mechanism due to acoustic phonons in noncentrosymmetric polar materials, is not accurately described at present. Current calculations include short-range e-ph interactions (obtained by interpolation) and the dipolelike Frölich long-range coupling in polar materials, but lack important quadrupole effects for acoustic modes and PE materials. Here we derive and compute the long-range e-ph interaction due to dynamical quadrupoles, and apply this framework to investigate e-ph interactions and the carrier mobility in the PE material wurtzite GaN. We show that the quadrupole contribution is essential to obtain accurate e-ph matrix elements for acoustic modes and to compute PE scattering. Our work resolves the outstanding problem of correctly computing e-ph interactions for acoustic modes from first principles, and enables studies of e-ph coupling and charge transport in PE materials.

Association between obstructive sleep apnoea syndrome and the risk of cardiovascular diseases: an updated systematic review and dose-response meta-analysis.

OBJECTIVE: The aim of this study was to summarize the evidence concerning the relationship between obstructive sleep apnoea syndrome (OSAS) and the risk of cardiovascular diseases (CVDs). METHODS: A systematic search was carried out using PubMed and Web of Science up to September 10, 2019. Categorical as well as linear and non-linear dose-response meta-analyses were respectively performed to evaluate the association between the severity of OSAS and the risk of CVDs. Apnoea-hypopnea index (AHI) was used as an indicator of OSAS severity. RESULTS: This study included 10 cohort studies targeting a total of 36,347 subjects and 3362 patients with CVDs. The pooled RRs of overall CVDs were 1.13 (95% confidence interval [CI] = 1.02-1.24) for mild versus non/normal OSAS, 1.16 (95% CI = 1.02-1.32) for moderate versus non/normal OSAS, 1.26 (95% CI = 1.15-1.39) for moderate-severe versus non/normal OSAS, and 1.41 (95% CI = 1.22-1.63) for severe versus non/normal OSAS. The linear dose-response meta-analysis showed that every 10 events/hour increment in AHI value was associated with a 9% increased risk of suffering from CVDs. The non-linear dose-response meta-analysis showed that the risk of CVDs increased continuously with the increment in AHI. CONCLUSION: The present systematic review and meta-analysis provide evidence for a positive association between OSAS and the risk of CVDs, despite the severity of OSAS. The relative risk of CVDs increases continuously with the increment in AHI.

Ab initio electron-two-phonon scattering in GaAs from next-to-leading order perturbation theory.

Electron-phonon (e-ph) interactions are usually treated in the lowest order of perturbation theory. Here we derive next-to-leading order e-ph interactions, and compute from first principles the associated electron-two-phonon (2ph) scattering rates. The derivations involve Matsubara sums of two-loop Feynman diagrams, and the numerical calculations are challenging as they involve Brillouin zone integrals over two crystal momenta and depend critically on the intermediate state lifetimes. Using Monte Carlo integration together with a self-consistent update of the intermediate state lifetimes, we compute and converge the 2ph scattering rates, and analyze their energy and temperature dependence. We apply our method to GaAs, a weakly polar semiconductor with dominant optical-mode long-range e-ph interactions. We find that the 2ph scattering rates are as large as nearly half the value of the one-phonon rates, and that including the 2ph processes is necessary to accurately predict the electron mobility in GaAs from first principles.

Electron-Phonon Scattering in the Presence of Soft Modes and Electron Mobility in SrTiO_{3} Perovskite from First Principles.

Structural phase transitions and soft phonon modes pose a long-standing challenge to computing electron-phonon (e-ph) interactions in strongly anharmonic crystals. Here we develop a first-principles approach to compute e-ph scattering and charge transport in materials with anharmonic lattice dynamics. Our approach employs renormalized phonons to compute the temperature-dependent e-ph coupling for all phonon modes, including the soft modes associated with ferroelectricity and phase transitions. We show that the electron mobility in cubic SrTiO_{3} is controlled by scattering with longitudinal optical phonons at room temperature and with ferroelectric soft phonons below 200 K. Our calculations can accurately predict the temperature dependence of the electron mobility in SrTiO_{3} between 150-300 K, and reveal the microscopic origin of its roughly T^{-3} trend. Our approach enables first-principles calculations of e-ph interactions and charge transport in broad classes of crystals with phase transitions and strongly anharmonic phonons.