High-throughput screening of the transport behavior of tetragonal perovskites.

Halide perovskites have attracted attention due to their low cost and excellent optoelectronic properties. Although their optical properties gained widespread consensus, there was still divergence in understanding carrier transport behavior. In this study, the mobility of tetragonal perovskites was investigated by empirical models, including longitudinal acoustic phonon (LAP) and polar optical phonon (POP) models. The results revealed that the mobility predicted from the LAP model was much higher than that from the POP model. A longitudinal optical phonon (LOP) was considered as the decisive scattering source for charge carriers in perovskites. Furthermore, the mobility was extremely sensitive to z-axis strain, and 8 types of perovskites with high carrier mobility were screened. Using the experimental lattice constants, the predicted mobility of CsSnI3 was µe,z = 1428 and µh,z = 2310 cm2 V-1 s-1, respectively. The tetragonal CsSnI3 has high mobility and moderate bandgaps, suggesting potential applications in high-efficiency solar cells.

Exploring the Dehydrogenation Reaction Pathway of Perhydro-Polycyclic Aromatic Hydrocarbons over the Pt/Al2O3 Catalyst as Liquid Organic Hydrogen Carriers by In Situ DRIFT.

Polycyclic aromatic hydrocarbons (PAHs) have been paid more attention as liquid organic hydrogen carriers (LOHCs) because of their high hydrogen storage, easy transportation, low price, and other advantages. Dehydrogenation is the key point of the PAH hydrogen storage. However, the dehydrogenation reaction rate of perhydro-PAHs is slow, and their pathway is still not clear. To clarify the PAH dehydrogenation pathway, three kinds of perhydro-PAHs containing six-membered rings (methylcyclohexane, perhydro-diphenylmethane, and perhydro-dibenzyltoluene) are selected, and their dehydrogenation processes over the Pt/Al2O3 catalyst are carried out by in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFT). It was found that the dehydrogenation in the six-membered ring started in the para position of the -CH3 group, and then, the six-membered ring was transformed into a benzene ring gradually. Between the six-membered rings, dehydrogenation started from the side ring, which has fewer groups.

Cryoballoon vs. radiofrequency catheter ablation: insights from NOrwegian randomized study of PERSistent Atrial Fibrillation (NO-PERSAF study).

AIMS: Pulmonary vein isolation (PVI) is still regarded as a cornerstone for treatment of persistent atrial fibrillation (AF). This study evaluated the effectiveness of PVI performed with cryoballoon ablation (CBA) in comparison with radiofrequency ablation (RFA) in patients with persistent AF. METHODS AND RESULTS: A total of 101 patients with symptomatic persistent AF were enrolled and randomized (1:1) to CBA or RFA groups and followed up for 12 months. The primary endpoint was any documented recurrent atrial tachyarrhythmia (ATA) lasting longer than 30 s following a 3-month blanking period. Secondary endpoints were procedure-related complications, procedure and ablation duration, and fluoroscopy time. The ATA-free survival curves were estimated by Kaplan-Meier method and analysed by the log-rank test. According to intention-to-treat analysis, freedom from ATA was achieved in 36 out of 52 patients in the CBA group and 30 out of 49 patients in the RFA group (69.2% vs. 61.2%, P = 0.393). No difference in AF recurrence was found between the two groups (27.5% in CBA vs. 38.0% in RFA, P = 0.258), and less atrial flutter recurrence was documented in the CBA group compared with the RFA group (3.9% vs. 18.0%, P = 0.020). The procedure and ablation duration were significantly shorter in the CBA group (160 ± 31 vs. 197 ± 38 min, P < 0.0001; 36.7 ± 9.5 vs. 55.3 ± 16.7 min, P < 0.0001). There was no difference regarding fluoroscopy time (21.5 ± 7.8 vs. 23.4 ± 11.2 min, P > 0.05). CONCLUSION: Compared with RFA, PVI performed by CBA led to shorter procedure and ablation duration, with less atrial flutter recurrence and similar freedom from ATA at 12-month follow-up.

Giant magnetic anisotropy of rare-earth adatoms and dimers adsorbed by graphene oxide.

Nowadays, transition-metal adatoms and dimers with giant magnetic anisotropy have attracted much attention due to their potential applications in data storage, spintronics and quantum computations. Using density-functional calculations, we investigated the magnetic anisotropy of the rare-earth adatoms and dimers adsorbed by graphene oxide. Our calculations reveal that the adatoms of Tm, Er and Sm possess giant magnetic anisotropy, typically larger than 40 meV. When the dimers of (Tm,Er,Sm)-Ir are adsorbed onto graphene oxide, the magnetic anisotropy even exceeds 200 meV. The magnetic anisotropy can be tuned by the external electric field as well as the environment.

Incidence and clinical predictors of subsequent atrial fibrillation requiring additional ablation after cavotricuspid isthmus ablation for typical atrial flutter.

OBJECTIVES: We sought to investigate the incidence of atrial fibrillation after catheter ablation for typical atrial flutter and to determine the predictors for symptomatic atrial fibrillation that required a further additional dedicated ablation procedure. DESIGN: 127 patients underwent elective cavotricuspid isthmus ablation with the indication of symptomatic, typical atrial flutter. The occurrence of atrial flutter, atrial fibrillation, cerebrovascular events and the need for additional ablation procedures for symptomatic atrial fibrillation was assessed during long-term follow-up. RESULTS: The majority of patients (70%) manifested atrial fibrillation during a follow-up period of 68 ± 24 months, and a significant proportion (42%) underwent one or multiple atrial fibrillation ablation procedures after an average of 26 months from the index procedure. Recurrence of typical atrial flutter was rare. Ten patients (8%) suffered cerebrovascular events. Earlier documentation of atrial fibrillation (OR 3.53), previous use of flecainide (OR 3.33) and left atrial diameter (OR 2.96) independently predicted occurrence of atrial fibrillation during the follow-up. A combination of pre- and intra-procedural documentation of atrial fibrillation (OR 3.81) and previous use of flecainide (OR 2.43) independently predicted additional atrial fibrillation ablation. DISCUSSION: Atrial fibrillation occurred in the majority of patients after ablation for typical atrial flutter and 42% of them required an additional dedicated ablation procedure. Pre- and intraprocedural documentation of atrial fibrillation together with previous use of flecainide independently predicted atrial fibrillation occurrence and a need for additional ablation. Anticoagulation treatment should be continued in high-risk patients in spite of clinical disappearance of atrial flutter.

Mycobacterium tuberculosis lipoprotein LprG binds lipoarabinomannan and determines its cell envelope localization to control phagolysosomal fusion.

Mycobacterium tuberculosis (Mtb) virulence is decreased by genetic deletion of the lipoprotein LprG, but the function of LprG remains unclear. We report that LprG expressed in Mtb binds to lipoglycans, such as lipoarabinomannan (LAM), that mediate Mtb immune evasion. Lipoglycan binding to LprG was dependent on both insertion of lipoglycan acyl chains into a hydrophobic pocket on LprG and a novel contribution of lipoglycan polysaccharide components outside of this pocket. An lprG null mutant (Mtb ΔlprG) had lower levels of surface-exposed LAM, revealing a novel role for LprG in determining the distribution of components in the Mtb cell envelope. Furthermore, this mutant failed to inhibit phagosome-lysosome fusion, an immune evasion strategy mediated by LAM. We propose that LprG binding to LAM facilitates its transfer from the plasma membrane into the cell envelope, increasing surface-exposed LAM, enhancing cell envelope integrity, allowing inhibition of phagosome-lysosome fusion and enhancing Mtb survival in macrophages.

Demonstration of nonlinear-energy-spread compensation in relativistic electron bunches with corrugated structures.

High quality electron beams with flat distributions in both energy and current are critical for many accelerator-based scientific facilities such as free-electron lasers and MeV ultrafast electron diffraction and microscopes. In this Letter, we report on using corrugated structures to compensate for the beam nonlinear energy chirp imprinted by the curvature of the radio-frequency field, leading to a significant reduction in beam energy spread. By using a pair of corrugated structures with orthogonal orientations, we show that the quadrupole wakefields, which, otherwise, increase beam emittance, can be effectively canceled. This work also extends the applications of corrugated structures to the low beam charge (a few pC) and low beam energy (a few MeV) regime and may have a strong impact in many accelerator-based facilities.

Effect of flecainide on the extension and localization of complex fractionated electrogram during atrial fibrillation.

AIMS: Complex fractionated electrogram (CFE) ablation in addition to pulmonary vein isolation is an accepted strategy for the treatment of non-paroxysmal atrial fibrillation (AF). We sought to determine the effect of flecainide on the distribution and extension of CFE areas. METHODS: Twenty-three non-paroxysmal AF patients were enrolled in this prospective study. A first CFE map was obtained under baseline conditions by sampling 5 s of continuous recording from the distal electrodes of the ablation catheter. Intravenous flecainide (1 mg/kg) was administered over 10 min and followed by 30-min observation time. A second CFE map was obtained with the same modalities. CFE-mean values, CFE areas, and atrial electrogram amplitude were retrieved from the electro-anatomical mapping system (Ensite NavX). RESULTS: After flecainide administration, CFE-mean values increased (111.5 ± 55.3 vs. 132.3 ± 65.0 ms, p < 0.001) with a decrease of CFE area (32.9%) in all patients. Atrial electrogram amplitude decreased significantly (0.30 ± 0.31 vs. 0.25 ± 0.20 mV, p < 0.001). We observed 80.9% preservation of CFE areas. A CFE mean of 78 ms was the best cutoff for predicting stable CFE areas. CONCLUSIONS: Flecainide reduces the extension of CFE areas while preserving their spatial localization. A CFE-mean value <80 ms may be crucial to define and locate stable CFE areas.

Plasma levels and potential roles of catestatin in patients with coronary heart disease.

OBJECTIVES: Catestatin (CST) is a new endogenous neuropeptide with a potent catecholamine release-inhibitory activity. This study was to investigate plasma CST levels in patients with coronary heart disease (CHD) and to determine the clinical significance of plasma CST in cardiovascular events. METHODS: A total of 120 CHD patients and 30 age/sex-matched healthy subjects were enrolled. Plasma CST level was measured using enzyme-linked immunosorbent assay (ELISA) and norepinephrine (NE) level was measured using high-performance liquid chromatography (HPLC). Clinical and laboratory data during hospitalization were collected, and a follow-up of 1045 days was carried out. RESULTS: Compared with controls, CHD patients had significantly higher plasma CST and NE levels on admission. ST segment elevation myocardial infarction (STEMI) patients had higher CST levels than angina pectoris patients had, but CST/NE ratios were unchanged among controls and different CHD subgroups. Plasma NE was the only independent factor associated with CST. As a dichotomous variable divided by the median value, plasma CST on admission was not associated with adverse cardiovascular events. CONCLUSIONS: Plasma CST level was positively correlated with that of NE and was elevated in parallel with that of NE in the different myocardial ischemia states. Plasma CST on admission was neither associated with adverse cardiac events nor was there any significant relationship between plasma CST and onset of new cardiovascular events. The pathophysiological role of CST in CHD needs further studies.

Thawing plateau time indicating the duration of phase transition from ice to water is the strongest predictor for long-term durable pulmonary vein isolation after cryoballoon ablation for atrial fibrillation-Data from the index and repeat procedures.

Introduction: This study aimed to clarify the relationship between the durability of pulmonary vein (PV) isolation and the time of phase transition from ice to water indicated by thawing plateau time in a cryoballoon ablation for atrial fibrillation (AF). Methods and results: In this retrospective study, 241 PVs from 71 patients who underwent a repeat AF ablation 526 (IQR: 412, 675) days after a cryoballoon ablation were analyzed. Reconnection was observed in 101 (41.9%) PVs of 53 patients (74.6%). Thawing plateau time (TimeTP) was defined as the time from 0°C to 10°C inside the balloon in the thawing period. Durable PV isolation was associated with significantly longer TimeTP compared with PV reconnection (26.0 vs. 11.0 s, P < 0.001). The proportion of durable PV isolations increased with TimeTP in a dose-proportional manner. The cut point for PV reconnection was TimeTP <15 s with a positive predictive value of 82.1% (sensitivity = 63.4%, specificity = 90.0%) while for durable PV isolation the cut point was TimeTP >25 s with a positive predictive value of 84.6% (sensitivity = 55.0%, specificity = 86.1%). In the analysis of multivariable logistic regression, location of PV reconnection (P < 0.01), TimeTP (P < 0.05) and thawing plateau integral (P < 0.01) were shown as independent predictors for durable PV isolation. Conclusion: TimeTP is an independent predictor for the durability of PV isolation, and it presents in a dose-proportional manner. TimeTP <15 s predicts long-term reconnection while TimeTP >25 s predicts durable PV isolation.

Acylation of glycerolipids in mycobacteria.

We report on the existence of two phosphatidic acid biosynthetic pathways in mycobacteria, a classical one wherein the acylation of the sn-1 position of glycerol-3-phosphate (G3P) precedes that of sn-2 and another wherein acylations proceed in the reverse order. Two unique acyltransferases, PlsM and PlsB2, participate in both pathways and hold the key to the unusual positional distribution of acyl chains typifying mycobacterial glycerolipids wherein unsaturated substituents principally esterify position sn-1 and palmitoyl principally occupies position sn-2. While PlsM selectively transfers a palmitoyl chain to the sn-2 position of G3P and sn-1-lysophosphatidic acid (LPA), PlsB2 preferentially transfers a stearoyl or oleoyl chain to the sn-1 position of G3P and an oleyl chain to sn-2-LPA. PlsM is the first example of an sn-2 G3P acyltransferase outside the plant kingdom and PlsB2 the first example of a 2-acyl-G3P acyltransferase. Both enzymes are unique in their ability to catalyze acyl transfer to both G3P and LPA.

A bioanalytical method to determine the cell wall composition of Mycobacterium tuberculosis grown in vivo.

Mycobacterium tuberculosis bacilli exhibit cell wall alterations during in vivo growth. Development of ultrasensitive analytical techniques with high specificities is required to analyze the cell wall of M. tuberculosis isolated from experimental animals because of the low amounts of bacteria available and contamination by host tissue. Here we present a novel methodology to analyze all three major components (mycolic acids, arabinogalactan, and peptidoglycan) of the mycobacterial cell wall from mycobacteria isolated from animal tissue. In this procedure, the cell wall carbohydrates are analyzed by gas chromatography tandem mass spectrometry (GC/MS/MS) of alditol acetates, the peptidoglycan by GC/MS (mass spectrometry) analysis of the unique amino acid diaminopimelic acid (after derivatization with isopropyl chloroformate), and the mycolic acids by liquid chromatography (LC)/MS (negative ion) without derivatization. The procedure was designed so that all three analyses could be performed starting with a single sample given the difficulty of preparing multiple aliquots in known ratios. Linkage analysis, including an enantiomeric specific procedure, of the arabinogalactan polymer is also presented. These procedures will enable the determination of the cell wall alterations known to occur in the important nongrowing "dormant" M. tuberculosis present during disease. With some adaptations, the methodology is also applicable to the analysis of small amounts of in vivo grown bacteria of other species.

Biaxial strain improving carrier mobility for inorganic perovskite:ab initioBoltzmann transport equation.

Inorganic halide perovskites have attracted interest due to their high efficiency and low cost. Considering the uncertainty of experimental measurements, it was important to predict the upper limit of carrier mobility. In this study, theab initioBoltzmann transport equation, including all electron-phonon interactions, was used to accurately predict the mobilities of CsPbI3, CsSnI3, CsPbBr3, and CsSnBr3. Using the iterative Boltzmann transport equation (IBTE), the calculated mobility for CsPbI3isµe= 512/µh= 379 cm2 V-1 s-1, and Sn-based perovskite exhibited high hole mobility. The longitudinal optical phonons associated with the stretching between halogen anions and divalent metal cations were revealed to be the dominant scattering source for the carriers. Furthermore, the effect of biaxial strain on mobility was investigated. We observed that biaxial compressive strain could improve the mobility of CsPbI3and CsPbBr3. Surprisingly, under a compressive strain of-2%, the mobilities of CsPbI3using IBTE approach were improved toµe= 1176/µh= 936 cm2 V-1 s-1. It was revealed that the compressive strain could decrease the effective mass of CsPbI3and CsPbBr3.

Comprehension of the Synergistic Effect between m&t-BiVO4/TiO2-NTAs Nano-Heterostructures and Oxygen Vacancy for Elevated Charge Transfer and Enhanced Photoelectrochemical Performances.

Through the utilization of a facile procedure combined with anodization and hydrothermal synthesis, highly ordered alignment TiO2 nanotube arrays (TiO2-NTAs) were decorated with BiVO4 with distinctive crystallization phases of monoclinic scheelite (m-BiVO4) and tetragonal zircon (t-BiVO4), favorably constructing different molar ratios and concentrations of oxygen vacancies (Vo) for m&t-BiVO4/TiO2-NTAs heterostructured nanohybrids. Simultaneously, the m&t-BiVO4/TiO2-NTAs nanocomposites significantly promoted photoelectrochemical (PEC) activity, tested under UV-visible light irradiation, through photocurrent density testing and electrochemical impedance spectra, which were derived from the positive synergistic effect between nanohetero-interfaces and Vo defects induced energetic charge transfer (CT). In addition, a proposed self-consistent interfacial CT mechanism and a convincing quantitative dynamic process (i.e., rate constant of CT) for m&t-BiVO4/TiO2-NTAs nanoheterojunctions are supported by time-resolved photoluminescence and nanosecond time-resolved transient photoluminescence spectra, respectively. Based on the scheme, the m&t-BiVO4/TiO2-NTAs-10 nanohybrids exhibited a photodegradation rate of 97% toward degradation of methyl orange irradiated by UV-visible light, 1.14- and 1.04-fold that of m&t-BiVO4/TiO2-NTAs-5 and m&t-BiVO4/TiO2-NTAs-20, respectively. Furthermore, the m&t-BiVO4/TiO2-NTAs-10 nanohybrids showed excellent PEC biosensing performance with a detection limit of 2.6 µM and a sensitivity of 960 mA cm-2 M-1 for the detection of glutathione. Additionally, the gas-sensing performance of m&t-BiVO4/TiO2-NTAs-10 is distinctly superior to that of m&t-BiVO4/TiO2-NTAs-5 and m&t-BiVO4/TiO2-NTAs-20 in terms of sensitivity and response speed.

Systematic analysis of virus nucleic acid sensor DDX58 in malignant tumor.

Introduction: In December 2019, a novel epidemic of coronavirus pneumonia (COVID-19) was reported，and population-based studies had shown that cancer was a risk factor for death from COVID-19 infection. However, the molecular mechanism between COVID-19 and cancer remains indistinct. In this paper, we analyzed the nucleic acid sensor (DDX58) of SARS-CoV-2 virus, which is a significant gene related to virus infection. For purpose of clarifying the characteristics of DDX58 expression in malignant tumors, this study began to systematically analyze the DDX58 expression profile in the entire cancer type spectrum. Methods: Using TCGA pan-cancer database and related data resources, we analyzed the expression, survival analysis, methylation expression, mutation status, microsatellite instability (MSI), immune related microenvironment, gene related network, function and drug sensitivity of DDX58. Results: The expression level of DDX58 mRNA in most cancers was higher than the expression level in normal tissues. Through TIMER algorithm mining, we found that DDX58 expression was closely related to various levels of immune infiltration in pan-cancer. The promoter methylation level of DDX58 was significantly increased in multiple cancers. In addition, abnormal expression of DDX58 was related to MSI and TMB in multiple cancers, and the most common type of genomic mutation was "mutation." In the protein-protein interaction (PPI) network, we found that type I interferon, phagocytosis, ubiquitinase, and tumor pathways were significantly enriched. Finally, according to the expression of DDX58 indicated potential sensitive drugs such as Cediranib, VE-821, Itraconazole, JNJ-42756493, IWR-1, and Linsitinib. Discussion: In conclusion, we had gained new insights into how DDX58 might contribute to tumor development, and DDX58 could be used as an immune-related biomarker and as a potential immunotherapeutic target for COVID-19 infected cancer patients.

The impacts of contact force, power and application time on ablation effect indicated by serial measurements of impedance drop in both conventional and high-power short-duration ablation settings of atrial fibrillation.

BACKGROUND: This study aimed to clarify the interrelationship and additive effects of contact force (CF), power and application time in both conventional and high-power short-duration (HPSD) settings. METHODS: Among 38 patients with paroxysmal atrial fibrillation who underwent first-time pulmonary vein isolation, 787 ablation points were collected at the beginning of the procedure at separate sites. Energy was applied for 60 s under power outputs of 25, 30 or 35 W (conventional group), or 10 s when using 50 W (HPSD group). An impedance drop (ID) of 10 Ω was regarded as a marker of adequate lesion formation. RESULTS: ID ≥ 10 Ω could not be achieved with CF < 5 g under any power setting. With CF ≥ 5 g, ID could be enhanced by increasing power output or prolonging ablation time. ID for 30 and 35 W was greater than for 25 W (p < 0.05). Ablation with 35 W resulted in greater ID than with 30 W only when CF of 10-20 g was applied for 20-40 s (p < 0.05). Under the same power output, ID increased with CF level at different time points. The higher the CF, the shorter the time needed to reach ID of 10 Ω and maximal ID. ID correlated well with ablation index under each power, except for lower ID values at 25 W. ID with 50 W for 10 s was equivalent to that with 25 W for 40 s, but lower than that with 30 W for 40 s or 35 W for 30 s. CONCLUSIONS: CF of at least 5 g is required for adequate ablation effect. With CF ≥ 5g, CF, power output, and ablation time can compensate for each other. Time to reach maximal ablation effect can be shortened by increasing CF or power. The effect of HPSD ablation with 50 W for 10 s is equivalent to conventional ablation with 25 W for 40 s and 30-35 W for 20-30 s in terms of ID.

The Roles of Fractionated Potentials in Non-Macroreentrant Atrial Tachycardias Following Atrial Fibrillation Ablation: Recognition Beyond Three-Dimensional Mapping.

Introduction: Non-macroreentrant atrial tachycardia (nAT) following atrial fibrillation (AF) ablation is being increasingly reported. Many issues remain to be elucidated. We aimed to characterize the fractionated potentials (FPs) in nAT and introduce a new method of cross-mapping for clarifying their roles. Methods and Results: Forty-four nATs in 37 patients were enrolled and classified into focal AT (FAT, 12), microreentrant AT (MAT, 14), and small-loop-reentrant AT (SAT, 18) groups, according to activation pattern. FP was found on all targets except in nine FATs. The ratio of FP duration to AT cycle length (TCL) was different among groups (28 ± 7% in FAT, 53 ± 11% in MAT, and 42 ± 14% in SAT, p < 0.05), and ablation duration were longer in SATs (313 ± 298 vs. 111 ± 125 s, p < 0.05). The ratio of mappable cycle length to TCL was lower in the FAT group (63 ± 22% vs. 90 ± 9% and 89 ± 8%, p < 0.05). When cross-mapping was employed, trans-potential time differences in both longitudinal and transverse direction were longer around the culprit FP for MAT (p < 0.01). After Receiver Operating Characteristic curve analysis, it is best to adopt the sum of time difference ratios in both directions ≥60% as a cut-off value for discrimination of the FPs responsible for MAT with a sensitivity of 92% and specificity of 87%. Conclusions: FP could be found on target in most nATs following a previous AF ablation. The ratio of FP duration to TCL may help for differentiation. A simple method of cross-mapping could be employed to clarify the roles of FPs.

Origin of phonon-limited mobility in two-dimensional metal dichalcogenides.

Metal dichalcogenides are novel two-dimensional (2D) semiconductors after the discovery of graphene. In this article, phonon-limited mobility for six kinds of 2D semiconductors with the composition of MX2is reviewed, in which M (Cr, Mo and W) is the transition metal, and X (S and Se) is the chalcogen element. The review is divided into three parts. In the first part, we briefly introduce the calculation method of mobility, including the empirical model and Boltzmann transport theory (BTE). The application scope, merits and limitations of these methods are summarized. In the second part, we explore empirical models to calculate the mobility of MX2, including longitudinal acoustic phonon, optical phonon (OP) and polar optical phonon (POP) models. The contribution of multi-valley to mobility is reviewed in the calculation. The differences between static and high-frequency dielectric constants (Δϵ) are only 0.13 and 0.03 for MoS2and WS2. Such a low value indicates that the polarization hardly changes in the external field. So, their mobility is not determined by POP, but by deformation potential models. Different from GaAs, POP scattering plays a decisive role in its mobility. Our investigations also reveal that the scattering from POP cannot be ignored in CrSe2, MoSe2and WSe2. In the third parts, we investigate the mobility of MX2using electron-phonon coupling matrix element, which is based on BTE from the framework of a many-body quantum-field theory. Valence band splitting of MoS2and WS2is induced by spin-orbit coupling effect, which leads to the increase of hole mobility. In particular, we review in detail the theoretical and experimental results of MoS2mobility in recent ten years, and its mobility is also compared with other materials to deepen the understanding.

Effects of exogenous urotensin II on vascular remodelling after balloon injury.

1. Urotensin II (U-II) is a powerful vasoconstrictor peptide that stimulates cell proliferation. However, the systemic effects of U-II on cellular and extracellular matrix responses of vessel walls have not been investigated. The aim of the present study was to determine the effect of exogenous U-II on arterial neointimal hyperplasia after balloon injury. 2. A stenosis model of the thoracic aorta after balloon injury was established in male Wistar rats. Rats were divided into three groups (n = 5 in each): (i) uninjured; (ii) injured for 21 days; and (iii) injured and then treated with U-II (1 nmol/kg per h) via an osmotic minipump for 21 days. Another group of rats were killed on Days 7 and 14 after balloon injury for the analysis of in vitro collagen synthesis and secretion with U-II treated by [(3)H]-proline incorporation and determination of [(3)H]-hydroxyproline radioactivity, respectively. 3. Urotensin II immunoreactivity was 1.74-fold higher in vessels injured for 21 days than in uninjured vessels and mRNA levels of the urotensin UT receptor were upregulated by 55% following injury. After U-II treatment, the mRNA levels of the UT receptor were further upregulated (by 40%). In addition, U-II treatment increased the intimal area of injured aortas (13 +/- 5 vs 7 +/- 2% in group iii and ii, respectively), as well as increasing collagen content and cell proliferation. Protein levels of matrix metalloproteinase 1 were decreased in U-II-treated rats. In vitro, U-II treatment increased collagen synthesis and secretion in uninjured vessels in a concentration-dependent manner (10(-10), 10(-9) and 10(-8) mol/L U-II), especially in injured aortas on Day 7 after injury. 4. In conclusion, exogenous U-II may upregulate mRNA levels of the UT receptor, as well as increase collagen and cell proliferation, all of which would contribute to intimal hyperplasia after angioplasty.

Investigation of strain behavior and carrier mobility of organic-inorganic hybrid perovskites: (C4H9NH3)2GeI4 and (C4H9NH3)2SnI4.

Two dimensional (2D) organic-inorganic hybrid perovskites have attracted great interest due to their tunable band gap and structural stability. In this study, biaxial strain behavior and carrier mobility of monolayers (C4H9NH3)2GeI4 and (C4H9NH3)2SnI4 are investigated by first principles calculations. (C4H9NH3)2GeI4 and (C4H9NH3)2SnI4 still retain their structural stability at ε = 13% and ε = 15%, respectively. Ab initio molecular dynamics (AIMD) simulation has confirmed that the system at 300 K is still thermodynamically stable at a biaxial strain of ε = 8%. The band gaps of (C4H9NH3)2GeI4 and (C4H9NH3)2SnI4 calculated from the HSE06 functional are increased from 2.427 and 1.953 eV at zero strain to 3.002 and 2.626 eV at ε = 8%. Deformation potential (DP) models based on longitudinal acoustic phonon (LAP) and optical phonon (OP) scattering are used to investigate mobility. The mobility of (C4H9NH3)2GeI4 is lower than that of (C4H9NH3)2SnI4. It is mainly determined by the scattering from OP with lower energy and decreases sharply with an increase in biaxial strain. Compared with Pb based perovskites, (C4H9NH3)2SnI4 exhibits high carrier mobility and thermodynamic stability.