LncRNA RP11-301G19.1 is required for the maintenance of vascular smooth muscle cell contractile phenotype via sponging miR-17-5P/ATOH8 axis.

Long noncoding RNAs (LncRNAs) play essential roles in regulating gene expression in various biological processes. However, the function of lncRNAs in vascular smooth muscle cell (VSMC) transformation remains to be explained. In this work, we discover that a new bone marrow protein (BMP) signaling target, lncRNA RP11-301G19.1, is significantly induced in BMP7-treated VSMCs through lncRNA microarray analysis. Addition of BMP signaling inhibitor LDN-193189 attenuates the expression of ACTA2 and SM-22α, as well as the mRNA level of RP11-301G19.1. Furthermore, lncRNA RP11-301G19.1 is critical to the VSMC differentiation and is directly activated by SMAD1/9. Mechanistically, knocking down of RP11-301G19.1 leads to the decrease of ATOH8, another BMP target, while the forced expression of RP11-301G19.1 reactivates ATOH8. In addition, miR-17-5p, a miRNA negatively regulated by BMP-7, contains predicted binding sites for lncRNA RP11-301G19.1 and ATOH8 3'UTR. Accordingly, overexpression of miR-17-5p decreases the levels of them. Together, our results revealed the role of lncRNA RP11-301G19.1 as a miRNA sponge to upregulate ATOH8 in VSMC phenotype transformation.

Adhesion and friction behaviors of a γ-Fe/diamond heterogeneous contact interface: a density functional theory study.

Diamond tools play a vital role in precision machining. However, the adhesive wear restricts their application when Fe-based workpieces are cut by diamond tools. Thus, it is significant to theoretically explain the interface binding mechanism between the diamond and Fe alloy matrix. In this study, the adhesion and friction behaviors of a γ-Fe/diamond (denoted as Fe/C) heterogeneous contact interface were investigated employing density functional theory (DFT). The results show that the transfer of the Fe atom to C atom occurs when the interaction energy for a given configuration is larger than the separation energy of the corresponding Fe surface layers. The energy barriers of the Fe/C(100), (110) and (111) sliding interfaces along the minimum energy path are 1.45, 0.48 and 0.42 J m-2, respectively, indicating that the Fe/C(111) interface is the easiest to slide. Furthermore, the friction potential barrier increases with an increase in the load (1-5 nN) according to the potential energy curves. Moreover, the friction coefficient of the Fe/C interface is larger than 0.2 and provides a theoretical minimum friction coefficient for the Fe/C sliding interface.

Electrocardiographic and electrophysiological characteristics of ventricular arrhythmias from the right bundle branch of the moderator band.

BACKGROUND: There are little data on ventricular arrhythmias (VAs) originating from the right bundle branch (RBB) of the moderator band (MB) (MB-RBB VAs) in a cohort of patients. OBJECTIVE: The purpose of this study was to investigate the electrocardiographic and electrophysiological characteristics of MB-RBB VAs. METHODS: Sixteen patients with MB-RBB VAs and 5 patients with right ventricular (RV) anterior papillary muscle (APM) VAs (RV-APM VAs) were studied under the guidance of intracardiac echocardiography. RESULTS: The MB-RBB VAs group demonstrated a typical left bundle branch block pattern with left superior axis deviation and a narrower QRS complex during VAs (P < .001) as compared with the RV-APM VAs group. Furthermore, the MB-RBB VAs group had a shorter rS interval, a sharper slope of the S wave downstroke without notching in leads V1 and V2, and a shorter r wave duration in lead V2. A leading RBB potential at the target during VAs was observed for all patients in the MB-RBB VAs group, which was also present during sinus rhythm for all patients, except for 2 with RBB block at baseline. Ablation of the leading RBB potential effectively eliminated the arrhythmia. In the RV-APM VAs group, no Purkinje potential at the target was identified in any patient during VAs. CONCLUSION: QRS morphology of MB-RBB VAs is characterized by a typical left bundle branch block pattern with a relatively narrow QRS complex, short r wave and rS durations, and a sharp S wave downstroke without notching in leads V1 and V2. Mapping and ablation of the leading RBB potential are effective in eliminating VAs.

Enhancement of Potential Health Benefits of Insoluble Dietary Fiber from the Fruiting Body of Medicinal Mushroom Schizophyllum commune (Agaricomycetes) through Superfine Pulverization.

The objective of the current study is to reveal the influence of particle size of ground Schizophyllum commune and its extracted dietary fiber (DF) on physicochemical and antioxidant properties. Sch. commune powder and the extracted DF was ground by regular and superfine grinding, and their particle sizes were determined using laser diffraction particle size analyzer. The results indicated that superfine grinding could significantly pulverize DF particles to micro-scale; the particle size distribution presented a Gaussian distribution. The soluble DF in Sch. commune was increased effectively with superfine grinding. Sub-micronized insoluble DF showed increased total phenolic content (TPC) and ferric reducing antioxidant power (FRAP). Moreover, with particle size reduction, the oil binding capacity (OBC), nitrite ion absorption capacity (NIAC), cation-exchange capacity (CEC), cholesterol absorption capacity (CAC), and Pb ion adsorption capacity were significantly (p < 0.05) increased and the water retention capacity (WRC), swelling capacity (SC) and Cu, Zn ions adsorption capacity had no significant changes. A kind of health beneficial DF with higher soluble DF content, OBC, NIAC, CEC, CAC, Pb ion adsorption capacity and antioxidant activity (TPC and FRAP) was obtained through superfine grinding. Sch. commune DF could be potentially used as an ingredient for functional food and nutraceuticals.

A single QTL harboring multiple genetic variations leads to complicated phenotypic segregation in apple flesh firmness and crispness.

KEY MESSAGE: Within a QTL, the genetic recombination and interactions among five and two functional variations at MdbHLH25 and MdWDR5A caused much complicated phenotype segregation in apple FFR and FCR. The storability of climacteric fruit like apple is a quantitative trait. We previously identified 62 quantitative trait loci (QTLs) associating flesh firmness retainability (FFR) and flesh crispness retainability (FCR), but only a few functional genetic variations were identified and validated. The genetic variation network controlling fruit storability is far to be understood and diagnostic markers are needed for molecular breeding. We previously identified overlapped QTLs F16.1/H16.2 for FFR and FCR using an F1 population derived from 'Zisai Pearl' × 'Red Fuji'. In this study, five and two single-nucleotide polymorphisms (SNPs) were identified on the candidate genes MdbHLH25 and MdWDR5A within the QTL region. The SNP1 A allele at MdbHLH25 promoter reduced the expression and SNP2 T allele and/or SNP4/5 GT alleles at the exons attenuated the function of MdbHLH25 by downregulating the expression of the target genes MdACS1, which in turn led to a reduction in ethylene production and maintenance of higher flesh crispness. The SNPs did not alter the protein-protein interaction between MdbHLH25 and MdWDR5A. The joint effect of SNP genotype combinations by the SNPs on MdbHLH25 (SNP1, SNP2, and SNP4) and MdWDR5A (SNPi and SNPii) led to a much broad spectrum of phenotypic segregation in FFR and FCR. Together, the dissection of these genetic variations contributes to understanding the complicated effects of a QTL and provides good potential for marker development in molecular breeding.

Short term outcomes of extremely low birth weight infants from a multicenter cohort study in Guangdong of China.

With the increase in extremely low birth weight (ELBW) infants, their outcome attracted worldwide attention. However, in China, the related studies are rare. The hospitalized records of ELBW infants discharged from twenty-six neonatal intensive care units in Guangdong Province of China during 2008-2017 were analyzed. A total of 2575 ELBW infants were enrolled and the overall survival rate was 55.11%. From 2008 to 2017, the number of ELBW infants increased rapidly from 91 to 466, and the survival rate improved steadily from 41.76% to 62.02%. Increased survival is closely related to birth weight (BW), regional economic development, and specialized hospital. The incidence of complications was neonatal respiratory distress syndrome (85.2%), oxygen dependency at 28 days (63.7%), retinopathy of prematurity (39.3%), intraventricular hemorrhage (29.4%), necrotizing enterocolitis (12.0%), and periventricular leukomalacia (8.0%). Among the 1156 nonsurvivors, 90.0% of infants died during the neonatal period (≤ 28 days). A total of 768 ELBW infants died after treatment withdrawal, for reasons of economic and/or poor outcome. The number of ELBW infants is increasing in Guangdong Province of China, and the overall survival rate is improving steadily.

Insight into Point Defects and Complex Defects in ß-Mo2C and Carbide Evolution from First Principles.

In this paper, first principles method was adopted to investigate the point defects, Vanadium-related defects and defect combinations (vacancy (V), substitutional (S) and/or interstitial (I)) in molybdenum ß-Mo2C and explore the use of first principles calculation data in analysing the link between different carbides and the effects of doping elements. Supercell models with different defect types were established and optimized, and the formation energy data of defects was developed. The structure evolution during the optimization process is analysed in detail to establish the main characteristics of changes and the relevant electronic properties. The data for different types of intrinsic defects and combined defects complexes was developed and key results is analysed. The results show that carbon vacancy (VC) is stable but does not inevitably exist in pure ß-Mo2C. Interstitial site II is a very unstable position for any type of atoms (Mo, V and C), and analysis of the structure evolution shows that the atom always moves to the interface area near the interstitial site I between two layers. In particular, a C atom can expand the lattice structure when it exists between the layer interfaces. One type of the defects studied, the substitution of Mo with V (designated as 'SV-Mo'), is the most stable defect among all single point defects. The data for defect complexes shows that the combination of multiple SV-Mo defects in the super cell being more stable than the combination of other defects (e.g., 'VMo+IC', 'SV-Mo+VC'). The data with increasing SV-Mo in (Mo, V)2C system is developed, and typical data (e.g., formation energy) for Mo-rich carbides and V carbides are correlated and the potential of the data in analysing transition of different carbides is highlighted. The relevance of using first principles calculation data in the studying of V-doping and the complex carbides (V- and Mo-rich carbides) evolution in different materials systems and future focus of continuous work is also discussed.

Clinical treatment outcomes and their changes in extremely preterm twins: a multicenter retrospective study in Guangdong Province, China. / è¶ æœªæˆç†ŸåŒèƒŽå„¿ä¸´åºŠæ•‘æ²»ç»“å±€åŠå˜åŒ–åˆ†æžï¼šä¸€é¡¹å¹¿ä¸œçœå¤šä¸­å¿ƒå›žé¡¾æ€§ç ”ç©¶.

OBJECTIVES: To investigate the clinical treatment outcomes and the changes of the outcomes over time in extremely preterm twins in Guangdong Province, China. METHODS: A retrospective analysis was performed for 269 pairs of extremely preterm twins with a gestational age of <28 weeks who were admitted to the department of neonatology in 26 grade A tertiary hospitals in Guangdong Province from January 2008 to December 2017. According to the admission time, they were divided into two groups: 2008-2012 and 2013-2017. Besides, each pair of twins was divided into the heavier infant and the lighter infant subgroups according to birth weight. The perinatal data of mothers and hospitalization data of neonates were collected. The survival rate of twins and the incidence rate of complications were compared between the 2008-2012 and 2013-2017 groups. RESULTS: Compared with the 2008-2012 group, the 2013-2017 group (both the heavier infant and lighter infant subgroups) had lower incidence rates of severe asphyxia and smaller head circumference at birth (P<0.05). The mortality rates of both of the twins, the heavier infant of the twins, and the lighter infant of the twins were lower in the 2013-2017 group compared with the 2008-2012 group (P<0.05). Compared with the 2008-2012 group, the 2013-2017 group (both the heavier infant and lighter infant subgroups) had lower incidence rates of pulmonary hemorrhage, patent ductus arteriosus (PDA), periventricular-intraventricular hemorrhage (P-IVH), and neonatal respiratory distress syndrome (NRDS) and a higher incidence rate of bronchopulmonary dysplasia (P<0.05). CONCLUSIONS: There is a significant increase in the survival rate over time in extremely preterm twins with a gestational age of <28 weeks in the 26 grade A tertiary hospitals in Guangdong Province. The incidences of severe asphyxia, pulmonary hemorrhage, PDA, P-IVH, and NRDS decrease in both the heavier and lighter infants of the twins, but the incidence of bronchopulmonary dysplasia increases. With the improvement of diagnosis and treatment, the multidisciplinary collaboration between different fields of fetal medicine including prenatal diagnosis, obstetrics, and neonatology is needed in the future to jointly develop management strategies for twin pregnancy.

Myocardin/microRNA-30a/Beclin1 signaling controls the phenotypic modulation of vascular smooth muscle cells by regulating autophagy.

Upon vascular injury, vascular smooth muscle cells (VSMCs) change from a contractile phenotype to a synthetic phenotype, thereby leading to atherogenesis and arterial restenosis. Myocardin (MYOCD) is essential for maintaining the contractile phenotype of VSMCs. Deletion of MYOCD in VSMCs triggers autophagy. However, the molecular mechanism underlying the effect of MYOCD on autophagy is not clear. In this study, knockdown of MYOCD in human aortic VSMCs (HA-VSMCs) triggered autophagy and diminished the expression of SMC contractile proteins. Inhibition of autophagy in MYOCD-knockdown cells restored the expression of contractile proteins. MYOCD activated the transcription of miR-30a by binding to the CArG box present in its promoter, as confirmed by luciferase reporter and chromatin immune coprecipitation assays, while miR-30a decreased the expression of autophagy protein-6 (ATG6, also known as beclin1) by targeting its 3'UTR. Restoring the expression of miR-30a in MYOCD-knockdown cells upregulated the levels of contractile proteins. Treatment of VSMCs with platelet-derived growth factor type BB (PDGF-BB) resulted in the transformation of VSMCs to a proliferative phenotype. A low level of miR-30a was observed in PDGF-BB-treated HA-VSMCs, and re-expression of miR-30a led to a decrease in proliferative marker expression. Furthermore, using a wire injury mouse model, we found that miR-30a expression was significantly downregulated in the arterial tissues of mice and that restoration of miR-30a expression at the injured site abolished neointimal formation. Herein, MYOCD could inhibit autophagy by activating the transcription of miR-30a and that miR-30a-mediated autophagy defects could inhibit intimal hyperplasia in a carotid arterial injury model.

Pressure-induced structure, elasticity, intrinsic hardness and ideal strength of tetragonal C4N.

A tetragonal C4N (t-C4N) structure was predicted via CALYPSO code, and the effects of pressure on its structural and mechanical properties were studied. The results show that t-C4N is different from various 2D CxNy compounds with a new type 3D crystal structure, which is similar to diamond. Bulk t-C4N is equipped with excellent elastic properties. When the pressure is increased from 0 GPa to 350 GPa, its bulk modulus B, shear modulus G and Young's modulus E are increased from 426.9 GPa to 1123.1 GPa, 371.4 GPa to 582.9 GPa and 863.7 GPa to 1490.9 GPa, respectively. The anisotropic Bmax, Gmax and Emax are increased from 582.38 GPa to 1751.41 GPa, 478.29 GPa to 1033.97 GPa and 1281.26 GPa to 2490.14 GPa, respectively. When the pressure is 0 GPa, the hardness calculated by Chen's and Tian's models are 51.15 GPa and 51.81 GPa, respectively. Its ideal tensile strength in [111] orientation is the smallest (63.46 GPa), which indicates that the (111) planes allow easy cleavage. The smallest ideal shear strength (67.98 GPa) can be obtained in the (111)[11̄0] orientation, which suggests its theoretical hardness is about 67.98 GPa. Due to its excellent mechanical properties, t-C4N can be used as an industrial superhard material.

Ventricular arrhythmias ablated successfully in the subvalvular interleaflet triangle between the right and left coronary cusps: Electrophysiological characteristics and catheter ablation.

BACKGROUND: Ventricular arrhythmias (VAs) ablated successfully at the right-left subvalvular interleaflet triangle (R-L ILT) between right and left coronary cusps have not been fully characterized. OBJECTIVE: The purpose of this study was to investigate the electrophysiological characteristics of these VAs and their relationships with the left ventricular (LV) summit. METHODS: Twenty-eight VAs ablated successfully at the R-L ILT were studied. RESULTS: Ninety-six percent of VAs had an early precordial electrocardiographic transition. R-wave amplitude in lead V1 was relatively high (RS morphology, R-wave amplitude 0.35 ± 0.09 mV; R/S ratio 0.35 ± 0.27), whereas the morphology of lead I was R-shaped in 71% and M-shaped in 50% of VAs. Earliest potential was recorded at the R-L ILT in 13 of 28 patients and the left pulmonary sinus cusp (LC) in 6 of 28 patients. Mapping the summit communicating vein (summit-CV) failed because of anatomic or instrumental limitations in these 19 patients. In the other 9 patients, earliest potential was successfully recorded at the summit-CV, while perfect pacemapping was achieved. Poor pace mapping was achieved at the R-L ILT or LC in most patients (27/28). Target site was located at the top of the R-L ILT in all cases. A presystolic potential was present at the target site in 18 of 28 patients. A U-curve via the retrograde method was conventionally used to reach the top of the R-L ILT. CONCLUSION: VAs ablated successfully at the R-L ILT have unique electrophysiological characteristics, and R-L ILT may be an endocardial anatomic ablation target for VAs originating from the base of the LV summit.

Incidence of permanent pacemaker implantation after valve replacement surgery : Cardiac structure and function at 1-year follow-up.

BACKGROUND: Our study aimed to explore the incidence and risk factors of permanent pacemaker implantation (PPI) after valve replacement surgery (VR). The influence of long-term pacemaker dependency on cardiac structure and function at the 1­year follow-up was also assessed. METHODS: The demographic and surgical data of all consecutive patients who underwent VR between 2013 and 2016 were collected. Univariate and multivariate analyses were performed to identify variables independently associated with PPI after VR. A 1­year follow-up was undertaken of patients who underwent dual-chambers pacemaker after VR because of complete atrioventricular block (AVB). Long-term pacemaker dependency and recovery of cardiac structure and function were evaluated. RESULTS: There were 5320 consecutive patients with VR. The incidence of postoperative PPI was 2.42%. Multivariate analysis indicated that among the 62 patients who underwent PPI due to AVB and sick sinus syndrome, isolated aortic valve replacement (AVR; OR: 2.24, p < 0.05), VR combined with ventricular septal defect (VSD) repair (OR: 6.78, p < 0.05), and VR with aortic root and arch surgery (OR: 4.14, p < 0.05) were independent predictors of PPI after surgery. In total, 89.6% (43/48) of the survivors showed pacemaker dependency. Of these 43 patients, 24 had enlarged left heart before VR. Compared with preoperative values, the left atrial and left ventricular end-diastolic diameter post-PPI decreased significantly, while left ventricular ejection fraction was not significantly different. CONCLUSION: Isolated AVR, VR concomitant with VSD repair, and VR with aortic root and arch surgery are independent predictors of PPI after VR. The majority of patients do not recover from AVB disorders and there is no significant negative effect on recovery of cardiac structure and function.

Effect of Combined Pulmonary Vein and Superior Vena Cava Isolation on the Outcome of Second Catheter Ablation for Paroxysmal Atrial Fibrillation.

Recurrence of paroxysmal atrial fibrillation (AF) is partly due to pulmonary vein (PV) reconnection and non-PV foci, especially superior vena cava (SVC). We aimed to investigate the efficacy and safety of empiric SVC isolation plus PV isolation after first failed radiofrequency ablation involving only PV isolation for paroxysmal AF. Procedural and follow-up outcomes of ablation for 144 consecutive paroxysmal AF patients after first failed radiofrequency ablation involving only PV isolation were retrospectively compared between patients undergoing either conventional SVC isolation (additional SVC isolation if SVC-triggered AF or rapid SVC activity was observed; n = 72) or empiric SVC isolation after PV isolation (n = 72). In conventional SVC isolation versus empiric SVC isolation groups: baseline characteristics and proportion of recorded PV electrical potentials were similarly distributed and all pulmonary veins were successfully reisolated; SVC isolation was performed less often (6 [8.3%] vs 70 [97.2%]; p <0.001, respectively); and during 19 ± 10 months follow-up, atrial tachyarrhythmias recurrence-free rate after a second procedure was lower (58.3% vs 77.8%, log rank; p = 0.037). Multivariate regression analysis revealed LA diameter ≥45 mm (odds ratio [OR] = 2.5; 95% confidence interval [CI], 1.4 to 4.6; p = 0.002) as the independent risk factor of atrial tachyarrhythmias recurrence and empiric SVC isolation (OR = 0.47; 95% CI, 0.25 to 0.87; p = 0.016) as the independent protector against atrial tachyarrhythmias recurrence after a second ablation procedure. Empiric SVC isolation plus PV isolation did not increase significantly procedural time or complications. In conclusion, the strategy of empiric SVC isolation plus PV isolation during a second procedure for paroxysmal AF improved atrial tachyarrhythmias recurrence-free rate without increasing procedural time or complications.

Short-term outcomes of extremely preterm infants at discharge: a multicenter study from Guangdong province during 2008-2017.

BACKGROUND: An increasing number of extremely preterm (EP) infants have survived worldwide. However, few data have been reported from China. This study was designed to investigate the short-term outcomes of EP infants at discharge in Guangdong province. METHODS: A total of 2051 EP infants discharged from 26 neonatal intensive care units during 2008-2017 were enrolled. The data from 2008 to 2012 were collected retrospectively, and from 2013 to 2017 were collected prospectively. Their hospitalization records were reviewed. RESULTS: During 2008-2017, the mean gestational age (GA) was 26.68 ± 1.00 weeks and the mean birth weight (BW) was 935 ± 179 g. The overall survival rate at discharge was 52.5%. There were 321 infants (15.7%) died despite active treatment, and 654 infants (31.9%) died after medical care withdrawal. The survival rates increased with advancing GA and BW (p < 0.001). The annual survival rate improved from 36.2% in 2008 to 59.3% in 2017 (p < 0.001). EP infants discharged from hospitals in Guangzhou and Shenzhen cities had a higher survival rate than in others (p < 0.001). The survival rate of EP infants discharged from general hospitals was lower than in specialist hospitals (p < 0.001). The major complications were neonatal respiratory distress syndrome, 88.0% (1804 of 2051), bronchopulmonary dysplasia, 32.3% (374 of 1158), retinopathy of prematurity (any grade), 45.1% (504 of 1117), necrotizing enterocolitis (any stage), 10.1% (160 of 1588), intraventricular hemorrhages (any grade), 37.4% (535 of 1431), and blood culture-positive nosocomial sepsis, 15.7% (250 of 1588). The multivariate logistic regression analysis indicated that improved survival of EP infants was associated with discharged from specialist hospitals, hospitals located in high-level economic development region, increasing gestational age, increasing birth weight, antenatal steroids use and a history of premature rupture of membranes. However, twins or multiple births, Apgar ≤7 at 5 min, cervical incompetence, and decision to withdraw care were associated with decreased survival. CONCLUSIONS: Our study revealed the short-term outcomes of EP infants at discharge in China. The overall survival rate was lower than the developed countries, and medical care withdrawal was a serious problem. Nonetheless, improvements in care and outcomes have been made annually.

Cavotricuspid isthmus ablation using ablation index in typical right atrial flutter.

BACKGROUND: Ablation index (AI) has been evaluated as guidance quality marker for pulmonary vein isolation, but not for linear ablation of the cavotricuspid isthmus (CTI) for typical right atrial flutter (AFL). We thus studied the feasibility and effectiveness of AI-guided CTI for AFL. METHODS: Procedural and 6-month outcomes of ablation for AFL were retrospectively compared between consecutive patients undergoing either AI-guided ablation of CTI (n = 43; AI target of 500 for anterior 2/3 segments and 400 for posterior 1/3 segments) or contact force (CF)-guided ablation (n = 42) at a single center. Each Visitag dataset from all patients in each group was analyzed. RESULTS: AI guidance vs CF guidance was associated with: higher first-pass conduction block of CTI (93.0% vs 76.2%, P = .03) with similar ablation time; similar acute spontaneous CTI reconnection 2.3% vs 9.5%, P = .343); fewer radiofrequency (RF) applications (10.1 ± 2.8 vs 11.5 ± 3.0, P = .031) needed to achieve CTI directional block; significantly higher mean ablation time, impedance drop, force time integral and AI and similar mean CF and power of each VisiTag point. One inguinal hematoma and one pseudoaneurysm developed in the AI and CF groups, respectively. Recurrent AFL was recorded in two (4.7%) AI-group patients and four (9.5%) CF-group patients (P = .650). CONCLUSION: AI-guided ablation of CTI line for AFL appears feasible and effective with similar ablation time, fewer RF applications, a higher rate of first-pass conduction block, and no additional complications.

Synergistic effect of internal electric field and oxygen vacancy on the photocatalytic activity of BiOBrxI1-x with isomorphous fluorine substitution.

Recently, bismuth oxyhalide photocatalysts have attracted much attention owing to their unique layered structure. In this paper, fluorine isomorphously substituted BiOBrxI1-x solid solution was synthesized by controlling the molar ratios of F, Br and I elements by the chemical precipitation method at room temperature. It was found that BiOF0.4Br0.5I0.1 exhibited excellent photocatalytic activity for the degradation of methyl orange, which was 10.1, 5.0 and 4.3 times higher than that of BiOI, BiOBr and BiOBr0.9I0.1 under visible light irradiation, respectively. It could be inferred that fluorine substitution is favorable to enhance the internal electric field (IEF) for BiOBrxI1-x with layered structure, which could improve the separation efficiency of the photogenerated holes and electrons and thus enhance the photocatalytic activity. On the other hand, the concentration of oxygen vacancies (OVs) rose with the increase of fluorine content, which could facilitate the adsorption of pollutants and serve as trapping sites for photo-induced carriers to improve the photocatalytic activity. The finding provides new insights into the synergistic effect of IEF and OVs toward the construction of high efficient photocatalysts.

Welding of High Entropy Alloys-A Review.

High-entropy alloy (HEA) offers great flexibility in materials design with 3-5 principal elements and a range of unique advantages such as good microstructure stability, mechanical strength over a broad range of temperatures and corrosion resistance, etc. Welding of high entropy alloy, as a key joining method, is an important emerging area with significant potential impact to future application-oriented research and technological developments in HEAs. The selection of feasible welding processes with optimized parameters is essential to enhance the applications of HEAs. However, the structure of the welded joints varies with material systems, welding methods and parameters. A systemic understanding of the structures and properties of the weldment is directly relevant to the application of HEAs as well as managing the effect of welding on situations such as corrosion that are known to be a service life limiting factor of welded structures in conditions such as marine environments. In this paper, key recent work on welding of HEAs is reviewed in detail focusing on the research of main HEA systems when applying different welding techniques. The experimental details including sample preparation, sample size (thickness) and welding conditions reflecting energy input are summarized and key issues are highlighted. The microstructures and properties of different welding zones, in particular the fusion zone (FZ) and the heat affected zones (HAZ), formed with different welding methods are compared and presented in details and the structure-property relationships are discussed. The work shows that the weldability of HEAs varies with the HEA composition groups and the welding method employed. Arc and laser welding of AlCoCrFeNi HEAs results in lower hardness in the FZ and HAZ and reduced overall strength. Friction stir welding results in higher hardness in the FZ and achieves comparable/higher strength of the welded joints in tensile tests. The welded HEAs are capable of maintaining a reasonable proportion of the ductility. The key structure changes including element distribution, the volume fraction of face centered cubic (FCC) and body centered cubic (BCC) phase as well as reported changes in the lattice constants are summarized and analyzed. Detailed mechanisms governing the mechanical properties including the grain size-property/hardness relationship in the form of Hall-Petch (H-P) effect for both bulk and welded structure of HEAs are compared. Finally, future challenges and main areas to research are highlighted.

Analyses of risk factors and prognosis for new-onset atrial fibrillation in elderly patients after dual-chamber pacemaker implantation.

OBJECTIVE: To retrospectively identify risk factors and the prognosis for new-onset atrial fibrillation (AF) after implantation of dual-chamber pacemakers in elderly patients. METHODS: Consecutive patients aged ≥ 65 years who underwent their first implantation of a dual-chamber permanent pacemaker in Beijing Anzhen Hospital from October 2013 to May 2016 were enrolled. Their complete programming and follow-up data were recorded. Follow-up end points included new-onset AF and major adverse cardiovascular and cerebrovascular events. RESULTS: Altogether, 322 patients were enrolled, with new-onset AF observed in 79 (24.5%) during their follow-up. Multivariable analysis identified four independent predictors of new-onset AF in elderly patients after pacemaker implantation: hypertension (HR = 3.040, 95% CI: 1.09-3.05, P = 0.00); age (HR = 1.966, 95% CI: 1.57-3.68, P = 0.01); left atrial enlargement (HR = 1.645, 95% CI: 1.05-1.25, P = 0.03); high ventricular pacing rate (HR = 1.137, 95% CI: 1.01-1.06, P = 0.01). Univariable analysis indicated that the CHA2DS2-VASc score was also a risk factor for AF (HR = 1.368, 95% CI: 1.178-1.589, P = 0.002), whereas multivariable regression analysis did not. Kaplan-Meier survival analysis showed that the risk for ischemic stroke was significantly higher in the new-onset AF group than in the non-AF group (P < 0.05). CONCLUSION: Hypertension, age, left atrial enlargement, and high ventricular pacing rate were independent predictors of new-onset AF in elderly patients after implantation of a permanent pacemaker. New-onset AF increased the risk for ischemic stroke.

Mapping and ablation of RVOT-type arrhythmias: comparison between the conventional and reversed U curve methods.

PURPOSE: We assessed conventional and reversed U curve methods for mapping and ablation of RVOT-type VAs. METHODS: Single-center data were reviewed from consecutive cases of symptomatic VAs of RVOT-type origin that were mapped and ablated successfully using conventional method in RVOT (pulmonary artery might be included) from January 2014 to December 2015 (cohort 1, n = 75) or conventional method in RVOT and reversed U curve in PSC (for first ablation attempt) from January 2016 to March 2017 (cohort 2, n = 60). RESULTS: At least 90% of RVOT-VAs could be eliminated using conventional method in RVOT or reversed U curve in PSC. For RVOT-VAs, if the earliest activation site was in midposterior free wall, midposterior septal side of RVOT, or anterior free wall/septal side of RVOT with conventional method, it was likely eliminated in right, left, and anterior PSC with reversed U curve method, respectively. Nearly the same earliest potential in almost the same region could be recorded by both methods. Compared with conventional method, the reversed U curve method showed better catheter stability and contact force during mapping and ablation, and showed distinctive features in presystolic potential recording, unipolar mapping, and ablation response. CONCLUSIONS: Most of RVOT-VAs could be eliminated using conventional method in RVOT or reversed U curve in PSC. However, the reversed U curve method has superiority in catheter stability and contact force, especially for VAs form free wall of RVOT.