Persistent left superior vena cava (PLSVC) is a rare congenital vascular anomaly. Permanent pacemaker implantation (PPI) in patients with PLSVC can be challenging because of the venous anomalies. We ...reported a case series of patients with PLSVC who underwent PPI with double active fixation leads.
From January 2012 to July 2016, 9 patients (three male and six females, mean age 68 ± 11 years) with PLSVC who received a dual-chamber pacemaker with double active fixation leads were enrolled retrospectively in this observational study. The indications for pacemaker implantation were symptomatic third-degree atrioventricular block in one and sick sinus syndrome in eight patients.
PPI were implanted successfully in all 9 patients. Successful positioning of the ventricular leads at the right ventricular outflow tract (RVOT) septum with a "C" shaped stylet was achieved in 7 patients (77.8%). In the remaining two cases, the ventricular leads were placed in the right ventricular apex and the inferior free wall of the sub-tricuspid annulus. The atrial leads were placed at the lateral wall of the right atrium in all patients. Procedure time and fluoroscopy time were 85.3 ± 11.3 min and 4.5 ± 1.1 min respectively. During a mean follow-up of 4 years, no complications were observed and pacing parameters did not change significantly.
PPI through PLSVC may be technically feasible, safe, and effective. Double active fixation leads may be standard for patients with PLSVC and most of the ventricular leads could be placed at the RVOT septum.
Based on the molecular interaction volume model (MIVM), the activities of components of Sn-Sb, Sb-Bi, Sn-Zn, Sn-Cu, and Sn-Ag alloys were predicted. The predicted values are in good agreement with ...the experimental data, which indicate that the MIVM is of better stability and reliability due to its good physical basis. A significant advantage of the MIVM lies in its ability to predict the thermodynamic properties of liquid alloys using only two parameters. The phase equilibria of Sn-Sb and Sn-Bi alloys were calculated based on the properties of pure components and the activity coefficients, which indicates that Sn-Sb and Sn-Bi alloys can be separated thoroughly by vacuum distillation. This study extends previous investigations and provides an effective and convenient model on which to base refining simulations for Sn-based alloys.
The recovery of tellurium and bismuth from bismuth telluride waste is of great significance in improving the utilization levels of renewable resources, protecting the ecological environment and ...alleviating the problem of resource shortages. In this paper, tellurium and bismuth were recovered from bismuth telluride waste by selective sulfidation–vacuum volatilization. The Gibbs free energy, phase diagram and thermodynamic equilibrium diagram for the core reaction were calculated and analyzed to determine the possible reactions and the conditions required for the stability of bismuth telluride during the sulfidation process. After calculating the saturated vapor pressures, it was concluded that tellurium and bismuth sulfide could be separated by vacuum volatilization. The thermogravimetric analyses and differential scanning calorimetry were then used to analyze the reaction between bismuth telluride and sulfur. The results indicated that the temperature range for the sulfidation reaction should be 491–620 K. The volatilization temperature of tellurium should be greater than 695 K. The evaporation kinetics for tellurium and bismuth sulfide showed that the evaporation rate of tellurium was much higher than that of bismuth sulfide. Furthermore, experiments were conducted to verify the reliability of the theoretical analysis, and these were in good agreement with the thermodynamic and kinetic results. The direct yields of tellurium and bismuth were 99.65% and 99.49%, respectively. These results confirmed that the selective sulfidation-vacuum volatilization method is a feasible alternative for recovery of tellurium and bismuth from bismuth telluride waste.
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•Thermodynamic show that this method can realize the separation of Te and Bi.•The experimental conditions were determined according to the kinetic study.•There is a good agreement between theoretical research and verification experiment.•The direct yields of Te and Bi were 99.65% and 99.49%, respectively.•This is a new method of bismuth telluride waste recovery.
Little is known about the mechanisms of intracellular sterol transport or how cells maintain the high sterol concentration of the plasma membrane (PM). Here we demonstrate that two inducible ...ATP-binding cassette (ABC) transporters (Aus1p and Pdr11p) mediate nonvesicular movement of PM sterol to the endoplasmic reticulum (ER) in Saccharomyces cerevisiae. This transport facilitates exogenous sterol uptake, which we find requires steryl ester synthesis in the ER. Surprisingly, while expression of Aus1p and Pdr11p significantly increases sterol movement from PM to ER, it does not alter intracellular sterol distribution. Thus, ER sterol is likely rapidly returned to the PM when it is not esterified in the ER. We show that the propensity of PM sterols to be moved to the ER is largely determined by their affinity for sterol sphingolipid-enriched microdomains (rafts). Our findings suggest that raft association is a primary determinant of sterol accumulation in the PM and that Aus1p and Pdr11p facilitate sterol uptake by increasing the cycling of sterol between the PM and ER.
Ribosome assembly factors have been extensively studied in yeast, and their abnormalities may affect the assembly process of ribosomes and cause severe damage to cells. However, it is not clear ...whether mRNA turnover protein 4 (MRT4) functions in the fungal growth and pathogenicity in
. Here, we identified the nucleus-located gene
using reverse genetics, and found that knockdown of
resulted in retard mycelia growth and complete loss of pathogenicity. Furthermore,
knockdown mutants showed almost no appressorium formation and oxalic acid production comparing to the wild-type and complementary strains. In addition, the abilities to ROS elimination and resistance to oxidative and osmotic stresses were also seriously compromised in
mutants. Overall, our study clarified the role of
MRT4 in
, providing new insights into ribosome assembly in regulating pathogenicity and resistance to environmental stresses of fungi.
To examine the pinocytotic pathways mediating native low-density lipoprotein (LDL) uptake by human macrophage colony-stimulating factor-differentiated macrophages (the predominant macrophage ...phenotype in human atherosclerotic plaques).
We identified the kinase inhibitor SU6656 and the Rho GTPase inhibitor toxin B as inhibitors of macrophage fluid-phase pinocytosis of LDL. Assessment of macropinocytosis by time-lapse microscopy revealed that both drugs almost completely inhibited macropinocytosis, although LDL uptake and cholesterol accumulation by macrophages were only partially inhibited (approximately 40%) by these agents. Therefore, we investigated the role of micropinocytosis in mediating LDL uptake in macrophages and identified bafilomycin A1 as an additional partial inhibitor (approximately 40%) of macrophage LDL uptake that targeted micropinocytosis. When macrophages were incubated with both bafilomycin A1 and SU6656, inhibition of LDL uptake was additive (reaching 80%), showing that these inhibitors target different pathways. Microscopic analysis of fluid-phase uptake pathways in these macrophages confirmed that LDL uptake occurs through both macropinocytosis and micropinocytosis.
Our findings show that human macrophage colony-stimulating factor-differentiated macrophages take up native LDL by macropinocytosis and micropinocytosis, underscoring the importance of both pathways in mediating LDL uptake by these cells.
Superhydrophobic surfaces based on electrospun fibrous structures exhibit advantages of additive manufacturing and enable the passage of gases. Compared to randomly deposited fibers, directionally ...aligned fibers improve the control of surface wetting by a specified fiber orientation and predictable liquid–fiber contact interface. In this article, we create superhydrophobicity with adjustable adhesion based on the understanding of droplet wetting behavior on directionally aligned fibers. Directionally aligned polystyrene fibers with different diameters and interfiber distances (l) are produced using electrospinning with a rotating fin collector. The wetting behavior of droplets on the surfaces dressed by aligned fibers is characterized, and a thermodynamic model of wetting behavior is established to guide the experimental studies. As a result, high-adhesive superhydrophobicity is achieved on weak hydrophobic substrate surfaces dressed by aligned polystyrene fibers with a diameter of 1.8 μm and l between 5 and 130 μm. Water droplets (2 μL) exhibit a maximum contact angle of 156° and adhere to the fiber-dressed surfaces by tilting upside down. Low-adhesive superhydrophobicity is achieved by introducing an additional layer of aligned fibers to increase the transition energy barrier. On the dual-layer structure with an upper-layer l of 9 μm, droplets show a contact angle of 155° and can readily roll off the surface. Moreover, increasing the upper-layer l to 15 μm reserves the surface to high-adhesive superhydrophobicity.
Carbon capture and storage (CCS) is now known to be an effective way to reduce greenhouse gas emissions especially CO2 to the atmosphere. Amino acid salt (AAS) solutions are regarded as promising CO2 ...absorbents compared to traditional amine solutions, as they are environmentally being with lower evaporation as well as fewer degradation issues. This paper is intended to review recent developments in CO2 capture using AASs. The thermodynamics and kinetics of CO2 and different AASs are illustrated in detail. We will also discuss the blended solutions containing AASs in terms of applications and absorption or regeneration performance. Additionally, we will present specific directions for future research on CO2-AAS systems. This paper could provide a guideline for effective carbon capture by new absorbents.
•A comprehensive review of amino acid salts fundamentals is introduced.•Detailed thermodynamics and kinetics between CO2 and various amino acid salts are discussed.•The developments of CO2 capture by amino acid salts in the fields of biogas upgrading, natural gas and flue gas purification are illustrated.
•The core–shell Ag@N-CQDs structures modified BiVO4 photocatalyst is synthesized.•Ag@N-CQDs exhibit surface plasmon resonance and up-conversion effect.•BiVO4/Ag@N-CQDs possess an enhanced molecular ...oxygen activation.•TheBiVO4/Ag@N-CQDs exhibit excellent photocatalytic efficiency and stability.
Visible-near infrared (Vis-NIR) light accounts for ~95% of solar light. In recent years, rational design of Vis-NIR responsive photocatalyst with improved photocatalytic performance has attracted growing concern. In this work, a Vis-NIR responsive photocatalyst was developed by integrating core–shell structured Ag@nitrogen-doped carbon quantum dots (N-CQDs) with BiVO4 nanosheets. The efficiencies of tetracycline hydrochloride (TC) removal based on the BiVO4/Ag@N-CQDs composite were 80.37% and 65.67% under visible light irradiation (λ > 420 nm) for 60 min and NIR light irradiation (λ > 760 nm) for 180 min, respectively. This improved photocatalytic performance of BiVO4/Ag@N-CQDs composite stems from the synergistic effect between BiVO4 nanosheets and core–shell structured Ag@N-CQDs nanoparticles. The as-prepared BiVO4/Ag@N-CQDs composite exhibits surface plasmon resonance (SPR) and molecular oxygen activation. Thus, the charge separation, light absorption in Vis-NIR region and oxidation ability are boosted during the photocatalytic activity. This work provides a new insight for designing advanced structure of Vis-NIR responsive photocatalyst.
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