Faster Migration Rate Research Articles

Adsorption behavior of non-ionic demulsifiers at the oil/water interface stabilized by asphaltenes: Experiments, adsorption kinetics, and mechanisms

Formation of emulsions containing asphaltenes is both undesirable and unavoidable in petroleum production. Chemical demulsifiers, such as non-ionic surfactants, have long been applied as the cheapest and most effective method of breaking emulsions by altering the oil/water interfacial properties. In this study, the association state of the asphaltenes, the dehydration rate, and the interfacial rheology under various demulsifier concentrations were used to analyze the contributions of non-ionic demulsifiers to the breaking of the asphaltene-containing emulsions. Additionally, the dynamic interfacial tension (DIFT) data over time were used to investigate the adsorption kinetics of the asphaltenes and the demulsifier at the oil/water interface. Results indicate that liquid paraffin enhanced the association of the asphaltene molecules, while the non-ionic demulsifier rendered asphaltene aggregate sizes smaller. The addition of the demulsifiers reduced the interfacial strength, leading to an unstable interface. The oil-soluble demulsifiers reduced IFT more effectively than the water-soluble ones, due to their faster migration rate and low interfacial tension gradient to the oil–water interface. The adsorption process of the asphaltenes, influenced by the demulsifier concentration, could be divided into three stages: a short-term diffusion-controlled process, a transition process, and a slow descent process (referred to as Regimes I, II, and III). In Regime I, the diffusion coefficient of asphaltenes increased with the demulsifier concentration, indicating that the demulsifier aided the dispersing of the asphaltenes in the solution. The equilibrium IFT and the maximum surface excess concentration of the asphaltenes in the long-term adsorption process decreased with the demulsifier concentration, indicating that the asphaltene-containing emulsions generally became unstable after adding the demulsifiers. Our results offer valuable insights into the adsorption kinetics and the mechanisms of alterations by the asphaltenes and demulsifiers of the oil/water interface, with implications for various interfacial phenomena (e.g., emulsion stability) involving surfactants in oil production, transportation, and processing.

Porous nickel–cobalt phosphate with oxygen-rich vacancies in situ grown on dopamine-modified cellulose textiles as self-supporting high mass loadings supercapacitor electrode

Transition-metal phosphates/phosphides showcase significant promise for energy-related applications because of their high theoretical electrochemical characteristics. However, sluggish electro/ion transfer rates and kinetically unfavorable reaction sites hinder their application at high mass loading. Herein, a self-supporting electrode based on transition-metal phosphates was successfully fabricated via a one-step electrodeposition process. The nanosheet structure of transition-metal phosphates, formed by interconnecting nanoparticles, effectively mitigates the impact of stress and achieves a high mass-loading (21 mg cm−2) of the electrode. Additionally, the oxygen vacancy-rich and porous nanostructure of transition-metal phosphates endows the as-prepared electrodes with a significantly increased conductivity and fast ion migration rate for enhancing electrochemical kinetics. Consequently, the as-fabricated transition-metal phosphate electrode displays the highest areal specific capacity of 39.2F cm−2. Furthermore, the asymmetric supercapacitor achieves a maximum energy density of 0.79 mWh cm−2 and a high capacity retention of 93.0 % for 10000 cycles under 60 mA cm−2. This work provides an ideal strategy for fabricating flexible electrodes with high mass loading and synthesizing transition-metal phosphate electrodes rich in oxygen vacancies.

Acid-activated α-MnO2 for photothermal co-catalytic oxidative degradation of propane: Activity and reaction mechanism

In order to further reduce the energy consumption of the conventional thermal catalytic oxidation system and improve the degradation efficiency of pollutants, photothermal synergistic catalytic oxidation (PTSCO) system was constructed in this paper with propane as simulated pollutant representing VOCs, and then the modified α-MnO2 catalysts were prepared by using the acid activation method, which were used for the catalytic oxidation of propane in PTSCO. The α-MnO2 with appropriate acid concentration possessed excellent low-temperature reducibility, abundant active oxygen species, fast oxygen migration rate and a large number of acid sites. The optimal catalyst, H0.05-MnO2, had a T90 of 204 °C in the PTSCO system, which reduced by more than 30 °C relative to the α-MnO2 (T90 of 235 °C). Moreover, H0.05-MnO2 demonstrated excellent water resistance and long-term stability (T = 45 h). It was shown that the combination of photocatalysis and thermocatalysis can improve propane degradation by examining the kinetics of propane degradation in the PTSCO system and the conformational relationship of propane degradation by catalysts. Furthermore, a multi-pathway synergistic mechanism between photocatalysis and thermocatalysis in the PTSCO system was proposed. This work provided a theoretical basis for the preparation of high-performance catalysts and the catalytic degradation of propane.

Role of CTGF and PI3K/Akt signaling pathway in paraquat-induced mesenchymal changes in alveolar epithelial cells

Objective: To investigate the role of connective tissue growth factor (CTGF) and PI3K/Akt signaling pathways in paraquat (PQ) -induced alterations in alveolar epithelial cell mesenchymalization (EMT) . Methods: In February 2023, RLE-6TN cells were divided into 2 groups, which were set as uncontaminated group and contaminated group (200 μmol/L PQ), and cellular EMT alteration, CTGF and PI3K/Akt signaling pathway related molecules expression were detected by cell scratch assay, qRT-PCR and western-blot assay. Using shRNA interference technology to specifically inhibit the expression of CTGF, RLE-6TN cells were divided into four groups: control group, PQ group (200 μmol/L PQ), interference group (transfected with a plasmid with shRNA-CTGF+200 μmol/L PQ), and null-loaded group (transfected with a plasmid with scramble- CTGF+200 μmol/L PQ), qRT-PCR and western blot were used to examine the alteration of the cellular EMT and the expression of molecules related to the activity of PI3K/Akt pathway. The PI3K/Akt signaling pathway was blocked by the PI3K inhibitor LY294002, and the expression of EMT-related molecules in cells of the control group, PQ group (200 μmol/L PQ), and inhibitor group (200 μmol/L PQ+20 μmol/L LY294002) was examined by qRT-PCR and western blot.The t-test was used to compare the differences between the two groups, while the analysis of variance (ANOVA) was applied to compare the differences among multiple groups. For further pairwise comparisons, the Bonferroni method was adopted. Results: The results of cell scratch test showed that compared with the uncontaminated group, RLE-6TN cells in the contaminated group had faster migration rate, lower mRNA and protein expression levels of E-Cadherin, and higher mRNA and protein expression levels of α-SMA, CTGF, PI3K and Akt, with statistical significance (P<0.05). After specific inhibition of CTGF expression, the mRNA and protein expression of CTGF, PI3K, Akt, and α-SMA in the cells of the interference group were significantly lower than that of the PQ group and the null-loaded group (P<0.05/6), whereas that of E-Cadherin was higher than that of the PQ group and the null-loaded group (P<0.05/6). Specifically blocking the PI3K/Akt signaling pathway, the mRNA and protein expression of PI3K, Akt and α-SMA in the cells of the inhibitor group was decreased compared with that of the PQ group (P<0.05/3), while the expression of E-Cadherin was elevated compared with that of the PQ group (P<0.05/3) . Conclusion: CTGF may promote PQ-induced alveolar epithelial cell EMT through activation of the PI3K/Akt signaling pathway. Inhibition of CTGF expression or blockade of PI3K/Akt signaling pathway activity can alleviate the extent of PQ-induced alveolar epithelial cell EMT.

Morphological and sedimentary characteristics of raked linear dunes in the southeastern Taklimakan Desert, China

Raked linear dunes were rarely reported, except in the Kumtagh Desert, leaving little known about the dynamic process. However, numerous raked linear dunes have formed in the Kat Kum dunefield of the southeastern Taklimakan Desert, which provides a new case to study the morphodynamics of these dunes. We conducted a comprehensive analysis on the dune morphometry, wind regime, sedimentary characteristics, and sand availability of these dunes. We found that grain size variation is an essential factor affecting the formation of raked linear dunes in addition to wind regime and limited sand availability. These dunes in the Kat Kum present small scale and easily reshaped with fast migration rate compared with these in the Kumtagh Desert, and distributed in areas with low sand cover. The primary ridge extended obliquely to the resultant drift direction, whereas the subsidiary ridge extend is nearly parallel to this direction. The grain size of the primary ridge is noticeably coarser than that of the subsidiary ridge. These dunes seem to have evolved from barchans. Under a north-northeast wind, barchans reshaped to asymmetrical barchans by extending their southeast limbs and eroding their northwest limbs, causing the ridge to be oblique to the resultant drift direction. The strong east-northeast wind erodes and reshapes the primary ridge, transporting fine sand to the northwest and resulting in the formation of proto-subsidiary ridges. With the elongation and lateral movement of primary ridge, a continuous subsidiary ridge with regular dune spacing forms on the northwest flank.

A highly sensitive self-powered sensing method designed on DNA circuit strategy and MoS2 hollow nanorods for detection of thalassemia

Thalassemia is one of the most common monogenic diseases, which seriously affects human growth and development, cardiovascular system, liver, etc. There is currently no effective cure for this disease, making screening for thalassemia particularly important. Herein, a self-powered portable device with high sensitivity and specificity for efficiently screening of low-level thalassemia is developed which is enabled with AuNPs/MoS2@C hollow nanorods and triple nucleic acid amplification technologies. It is noteworthy that AuNPs/MoS2@C electrode shows the advantages of high electrocatalytic activity, fast carrier migration rate and large specific surface area, which can significantly improve the stability and output signal of the platform. Using high-efficiency tetrahedral DNA as the probe, the target CD122 gene associated with thalassemia triggers a catalytic hairpin assembly reaction to achieve CD122 recycling while providing binding sites for subsequent hybridization chain reaction, greatly improving the detection accuracy and sensitivity of the device. A reliable electrochemical/colorimetric dual-mode assay for CD122 is then established, with a linear response range of 0.0001–100 pM for target concentration and open circuit voltage, and the detection limit is 78.7 aM (S/N = 3); a linear range of 0.0001–10000 pM for CD122 level and RGB Blue value, with a detection limit as low as 58.5 aM (S/N = 3). This method achieves ultra-sensitive and accurate detection of CD122, providing a new method for the rapid and accurate screening of thalassemia.

Molecular selection and environmental evaluation of eco-friendly surfactants to efficiently reduce pesticide pollution

Surfactants are widely used in industrial and agricultural production, especially as agrochemicals. However, the improvement of pesticide utilization by surfactants as the synergist should be achieved without adverse effects on crops, non-target organisms and related ecological environment, which is a lack of attention. Herein, the influence of the nonionic surfactant Triton X (TX) series with different hydrophilic chain lengths on the “Pesticide-Crop-Ecology” system was systematically studied. The impact behavior of TX droplets on the scallion leaf surface was predicted first by molecular dynamics (MD) simulation. Then the impact behavior, adhesion properties and foliar retention of TX droplets on the scallion leaf were investigated by physical experiments. The results showed that the TX-102 structure could increase leaf retention of pyraclostrobin (PYR) by 15.66% due to its fast molecular migration rate, strong adhesion and appropriate wettability with leaves. Furthermore, the environmental effect of the selected TX-102 was fully evaluated, and it was found that TX-102 was relatively safe for both Vicia faba cells and human 293t cells, although it slightly promoted the effect of PYR on cell apoptosis. Importantly, TX-102 has a potential repair effect on the damage to dominant soil bacteria caused by PYR. This study provides a new strategy for the development of efficient and environment-friendly pesticide synergists and sustainable agricultural development.

Three-dimensional porous Na4MnV(PO4)3 constructed by Aspergillus niger biological template as a high performance cathode for sodium ion batteries

The sodium super ion conductor (NASICON) structure materials have attracted extensive attention because of its open three-dimensional crystal network framework and fast sodium ion migration rate. However, the poor electronic conductivity due to the presence of phosphate groups and the consequent high cost have been a barrier to commercialization. In this work, Na4MnV(PO4)3 (NMVP) with three-dimensional porous structure is synthesized in situ using Aspergillus niger as a biological template (noted as NMVP/ANDC). The cell wall of Aspergillus niger is rich in hydroxyl groups, which can adsorb metal ions well, so that NMVP particles can be synthesized on Aspergillus niger without stacking and agglomeration. NMVP grows along Aspergillus niger mycelium has a spongy-like three-dimensional porous network structure, which helps the contact between active materials and electrolyte, reduces the migration distance of sodium ions, and improves the conductivity of active materials. Therefore, NMVP/ANDC has good rate performance and cycle stability. It can provide 109 mAh g−1 at 0.5 C and 79.6% capacity retention after 3000 cycles at 5 C. The biological template method is proposed in this paper opens up a simple way for the preparation of other three-dimensional porous network structural materials.

Optimizing lattice oxygen mobility and acidity of heteropoly acid catalysts for oxidation of isobutane to methacrylic acid

In this paper, a series of heteropoly acids, (Cs2.2Cu0.26V0.38)xPMo12O40 (x = 1.3, 1.1, 1.0, 0.88), are prepared, characterized and examined as the catalysts for the oxidation of isobutane to MAA. Under the employed reaction condition, Cs2.23Cu0.26V0.38PMo12O40 exhibits an isobutane conversion of 20% and a MAA selectivity of 51% at 335 °C, giving a MAA yield of 0.68 mmolMAA·h−1·gcatalyst−1. Lattice oxygen mobility and acidity of (Cs2.2Cu0.26V0.38)xPMo12O40 catalysts play key roles. A fast migration rate and a moderate release rate of lattice oxygen are beneficial to the selective oxidation of isobutane to MAA. Cs2.2Cu0.26V0.38PMo12O40 exhibits strong acid sites facilitating MAA desorption and surface sites strongly binding MAA, causing MAA polymerization which blocks the active sites and decreases the long-term catalytic activity. These results demonstrate that the optimization of lattice oxygen mobility and surface acidity is an effective strategy to fabricate efficient heteropoly acid catalysts for the oxidation of isobutane to MAA.

Dual-carbon coupled three-dimensional superstructures with dominant mesopores targeting fast potassium-ion storage

Carbon materials with three-dimensional (3D) superstructure are a promising anode for potassium-ion batteries (PIBs) because of its rich micropores and defects. However, plenty of micropores often need more time to make electrolyte fully infiltrate, and their irreversible trapping effect will inevitably cause the loss of active K-ions upon cycling. Besides, excessive defects easily arouse poor conductivity because the absence of continuous graphite domains. Hence, dual-carbon coupled 3D superstructure is constructed by pyrolyzing the mixture of zeolitic imidazolate framework and polyvinylpyrrolidone (ZIF8@PVP). Since the preferential decomposition of external PVP, the micropores in ZIF8-derived carbon are effectively inhibited while keeping considerable mesopores, thus substantially shortening ions diffusion distance. Moreover, the decomposition and shrinkage of ZIF8 particles in return prompt the PVP-derived carbon to create more defects, which favors the adsorption storage of K-ions. Not only that, the metallic Zn can catalyze the formation of continuous graphite domains, endowing fast electron migration rate. Accordingly, the optimized product not only delivers an excellent rate (188.2 mAh g−1 at 2 A g−1) and cyclability (over 1800 cycles) in K-half cells, but presents a high energy density (181.5 Wh kg−1) in potassium-ion hybrid capacitors.

Nanostructure engineering of polymeric carbon nitride with boosted photocatalytic antibacterial activity

Nanostructural engineering can achieve smart modulation of the physical and chemical properties of nanomaterials by changing their dimensions, morphologies, and shapes. Nanostructures of different dimensions affect the bactericidal activity of nano‐antibacterial materials. Herein, the nanostructures of the metal‐free antibacterial substance polymeric carbon nitride (PCN) were engineered to prepare. The PCN nanotubes, nanosheets, and microspheres exhibited defined dimensional and morphological characteristics from one‐dimensional (1D) to 2D to 3D. Nanostructuring did not change the crystallization and bonding of PCN, but it profoundly impacted the specific surface area, porosity, absorption spectrum, fluorescence spectrum, photoelectric response, and impedance. Unsurprisingly, the photocatalytic activity of PCN nanostructures in killing Escherichia coli appeared dimensional dependence. The low‐dimensional PCN nanostructures including nanosheets and nanotubes had significantly boosted bactericidal activity; the E. coli survival rates on them after 2 h of visible light irradiation were only 10.4 and 15.8%, respectively. The excellence of the activity can be attributed to the comprehensive effect of strong photo‐generated hole oxidation ability, long photo‐generated carrier lifetime, fast carrier migration rate, large surface area, and sharp shape. The implement of nanostructure engineering provided a promising way to enhance the antibacterial activity of PCN photocatalysts.

The performance changes and migration behavior of PLA/nano‐silver composite film by high‐pressure treatment in food simulation solution

AbstractPolylactic acid (PLA) is one of the most promising biodegradable materials, which can reduce the environmental pollution caused by food and material industry. The effect of the addition proportion of nano‐silver and different food simulant on the migration and the performance changes of film during migration were evaluated, revealing the association between the performance changes and nano‐silver migration. The results showed that nano‐silver had the largest migration amount and the fastest migration rate in 4% (v/v) acetic acid solution, followed by 50% (v/v) ethanol solution, and the lowest in isooctane solution. Performance changes were affected by the compatibility of silver nanoparticles and PLA, and the strength of the interaction between the film and acetic acid. Performances of composite film deteriorated during high proportions of nano‐silver addition and long soaking. Adding a small amount of nano‐silver to the composite was the effective method considering the balance between good performances and migration.

Spatial distribution and migration of 239+240Pu in Chinese soils

The migration of radionuclides is a critical threat to the soil and groundwater environment. This study investigates highly radiological toxic 239+240Pu in 647 surface soils and 66 soil cores in China. First, the spatial distributions of 239+240Pu activities and 240Pu/239Pu ratios are presented in Chinese surface soils. Second, four different types of vertical distribution of 239+240Pu, namely 45.4%, 40.9%, 9.1% and 4.5% of Chinese soil cores proportions are integrated using statistical analysis. Furthermore, different soil types are accompanied by different 239+240Pu vertical distributions, which relate closely to the 239+240Pu migration. Finally, based on the Convection Dispersion Equation (CDE) model, the present work find that the apparent convection velocities of 239+240Pu are ranging from 0.00032 ± 0.00031 cm a−1 to 0.473 ± 0.083 cm a−1. As shown by the four typical vertical activity distribution of 239+240Pu in soil cores, the deepened activity maximum value position of 239+240Pu implies a fast migration rate or apparent convection velocity. This study, for the first time, suggests a significant linear correlation (R2 = 0.847) between the depth of 239+240Pu maximum value (cm) and the apparent convection velocity (v, cm a−1). We hypothesize that v usually does not exceed 0.5 cm a−1 in the CDE model. A significant linear correlation is also identified between apparent dispersion coefficient (D, cm2 a−1) and v2 in Chinese soil cores from the CDE model. It will provide an important reference for harmful heavy metal migration research in the future.

Application of Metal-organic Framework Materials (MOFs) in the Photocatalytic CO2 Reduction: A Mini-Review

Abstract: In recent years, the effective use of CO2 has become one of the research hotspots worldwide to solve environmental pollution and energy shortage, whose excessive emission led to increasingly serious global environmental problems. Metal-organic frameworks (MOFs), with extraordinary specific surface areas, tunable surface chemistry, fast electron migration rate, large CO2 adsorption capacity, etc． are a new class of functional materials composed of metal ions/clusters and organic ligands, which have broad application potential in CO2 photocatalytic reduction. This paper systematically generalized the composition of the structure, discussed the methods of synthetics and expounded the photocatalytic properties and photocatalytic mechanism of MOFs. In addition, the application and research progress of MOFs functional materials in recent research are reviewed. The article also summarized challenges and prospects for the large-scale photocatalytic applications of MOFs catalysts. It guides the preparation of novel modified MOFs photocatalysts for high-efficiency applications in the field of CO2 reduction and photocatalytic degradation of dyes.

Surface modification to enhance cell migration on biomaterials and its combination with 3D structural design of occluders to improve interventional treatment of heart diseases

The dominant source of thromboembolism in heart comes from the left atrial appendage (LAA). An occluder can close LAA and significantly reduce the risk of strokes, particularly for those patients with atrial fibrillation. However, it is technically challenging to fabricate an LAA occluder that is appropriate for percutaneous implantation and can be rapidly endothelialized to accomplish complete closure and avoid severe complication. Hypothesizing that a fast migration rate of endothelial cells on the implant surface would lead to rapid endothelialization, we fabricated an LAA occlusion device for interventional treatment with a well-designed 3D architecture and a nanoscale 2D coating. Through screening of biomaterials surfaces with cellular studies in vitro including cell observations, qPCR, RNA sequencing, and implantation studies in vivo, we revealed that a titanium–nitrogen nanocoating on a NiTi alloy promoted high migration rate of endothelial cells on the surface. The effectiveness of this first nanocoating LAA occluder was validated in animal experiments and a patient case, both of which exhibited successful implantation, fast sealing and long-term safety of the device. The mechanistic insights gained in this study will be useful for the design of medical devices with appropriate surface modification, not necessarily for improved cell adhesion but sometimes for enhanced cell migration.

Migration phenology and patterns of American woodcock in central North America derived using satellite telemetry

American woodcock Scolopax minor (hereafter woodcock) migration ecology is poorly understood, but has implications for population ecology and management, especially related to harvest. To describe woodcock migration patterns and phenology, we captured and equipped 73 woodcock with satellite tracking devices in the Central Management Region (analogous to the Mississippi Flyway) of North America and documented migration paths of 60 individual woodcock and 87 autumn or spring woodcock migrations during 2014–2016. Woodcock migration at the scale of the Central Management Region was more synchronous in spring than in autumn, but unlike most other migratory birds, average duration of autumn migration (31 days) was shorter than duration of spring migration (53 days). This difference in migration duration resulted from woodcock making more close-together migratory stopovers during spring migration, not because woodcock had individual stopovers of longer duration. During autumn migration, the number of days, the number of stopovers, migration end date and net migration displacement were negatively related to initiation date and rate of migration, and the number of stopovers and the net migration displacement were negatively related with migration end date. Spring migration duration, end date, the number of stopovers and net migration displacement were negatively related to migration rate and initiation date was positively related to migration rate, suggesting that woodcock that initiated spring migration later had faster migration rates. Juvenile female woodcock began spring migration later than adult female woodcock. Our results provide a basis for comparing current harvest seasons with presence of migrating woodcock during autumn and provide insight into differential harvest of migratory versus local woodcock on breeding areas.

Slow demography and limited dispersal constrain the expansion of north‐eastern temperate forests under climate change

AbstractAimTree species may be vulnerable to migration lags because they are sessile, long‐lived, have a small intrinsic growth rate and relatively short dispersal. Our study assesses if those ecological mechanisms will mitigate the progression of the north‐eastern American temperate forest leading edge into the boreal forest.LocationThe North‐eastern boreal‐temperate forest ecotone (from 43° to 51° North and 80° to 60° West).TaxonOur approach involved 15 forest species classified into four representative forest communities of the eastern boreal‐temperate forest.MethodsWe performed simulations on the boreal‐temperate ecotone using a state and transition model (STM), wherein forest communities are classified in four states: boreal, temperate, mixed and stands in regeneration. We propose a new modelling approach based on metapopulation theory to account for dispersal limitations and the demography of the temperate and boreal forests. We calibrated the STM model with an extensive dataset of 48,940 forest inventory plots. We projected the boreal‐temperate forest landscape over 23 General Circulation models (GCMs) from the RCP 8.5 emission scenario to study the forest communities dynamics at the landscape scale under climate change.ResultsSimulations of climate changes predict a significant increase of temperate forest dominance within the ecotone, mainly due to the conversion of mixed stands into temperate stands. The leading edge of the temperate forest will however move only 304 m in latitude (95% CI: 0.18–0.56) into the boreal forest by the end of this century. In comparison, the average expansion rate was 2,555 m/year (95% CI: 1,969–2,932) when we released the dispersal constraint and even higher with an average rate of 7,197 m/year (95% CI: 5,722–9,776) when we released the dispersal and demography constraints.Main conclusionsThe northern edge of the temperate forest distribution does not change with almost no movement toward the north for either temperate or mixed communities by the end of this century. Slow demographic and dispersal rates prevent any substantial movement in temperate forests, with much faster migration rates when these constraints are removed.

Ectopic expression of 35 kDa and knocking down of 78 kDa SG2NAs induce cytoskeletal reorganization, alter membrane sialylation, and modulate the markers of EMT

SG2NA is a protein of the striatin family that organizes STRIPAK complexes. It has splice variants expressing differentially in tissues. Its 78 kDa isoform regulates cell cycle, maintains homeostasis in the endoplasmic reticulum, and prevents oxidative injuries. The 35 kDa variant is devoid of the signature WD-40 repeats in the carboxy terminal, and its function is unknown. We expressed it in NIH 3T3 cells that otherwise express 78 kDa variant only. These cells (35 EE) have altered morphology, faster rate of migration, and enhanced growth as measured by the MTT assay. Similar phenotypes were also seen in cells where the endogenous 78 kDa isoform was downregulated by siRNA (78 KD). Proteomic analyses showed that several cancer-associated proteins are modulated in both 35 EE and 78 KD cells. The 35 EE cells have diffused actin fibers, distinctive ultrastructure, reduced sialylation, and increased expression of MMP2 & 9. The 78 KD cells also had diffused actin fibers and an upregulated expression of MMP2. In both cells, markers epithelial to mesenchymal transition (EMT) viz, E- & N-cadherins, β-catenin, slug, vimentin, and ZO-1 were modulated partially in tune with the EMT process. Since NIH 3T3 cells are mesenchymal, we also expressed 35 kDa SG2NA in MCF-7 cells of epithelial origin. In these cells (MCF-7-35), the actin fibers were also diffused and the modulation of the markers was more in tune with the EMT process. However, unlike in 35 EE cells, in MCF-7-35 cells, membrane sialylation rather increased. We infer that ectopic expression of 35 kDa and downregulation of 78 kDa SG2NAs partially induce transformed phenotypes.

The synergy of germline C634Y and V292M RET mutations in a northern Chinese family with multiple endocrine neoplasia type 2A.

Genetic analysis for germline mutations of RET proto‐oncogene has provided a basis for individual management of medullary thyroid carcinoma (MTC) and pheochromocytoma. Most of compound mutations have more aggressive phenotypes than single point mutations, but the compound C634Y/V292M variant in MTC has never been reported. Thus, we retrospectively investigated synergistic effect of C634Y and V292M RET germline mutations in family members with multiple endocrine neoplasia type 2A. Nine of 14 family members in a northern Chinese family underwent RET mutation screening using next‐generation sequencing and PCR followed by direct bidirectional DNA sequencing. Clinical features of nine individuals were retrospectively carefully reviewed. In vitro, the scratch‐wound assay was used to investigate the difference between the cells carrying different mutations. We find no patients died of MTC. All 3 carriers of the V292M variant were asymptomatic and did not have biochemical or structural evidence of disease (age: 82, 62 and 58). Among 4 C634Y mutation carriers, 2 patients had elevated calcitonin with the highest (156 pg/mL) in an 87‐year‐old male. Two carriers of compound C634Y/V292M trans variant had bilateral MTC with pheochromocytoma or lymph node metastasis (age: 54 and 41 years, respectively). Further, the compound C634Y/V292M variant had a faster migration rate than either single point mutation in vitro (P < .05). In conclusion, the V292M RET variant could be classified as ‘likely benign’ according to ACMG (2015). The compound variant V292M/C634Y was associated with both more aggressive clinical phenotype and faster cell growth in vitro than was either single mutation.

Differential Wound Healing Capacity of Mesenchymal Stem Cell-Derived Exosomes Originated From Bone Marrow, Adipose Tissue and Umbilical Cord Under Serum- and Xeno-Free Condition.

Exosomes are nano-scale and closed membrane vesicles which are promising for therapeutic applications due to exosome-enclosed therapeutic molecules such as DNA, small RNAs, proteins and lipids. Recently, it has been demonstrated that mesenchymal stem cell (MSC)-derived exosomes have capacity to regulate many biological events associated with wound healing process, such as cell proliferation, cell migration and blood vessel formation. This study investigated the regenerative potentials for cutaneous tissue, in regard to growth factors associated with wound healing and skin cell proliferation and migration, by exosomes released from primary MSCs originated from bone marrow (BM), adipose tissue (AD), and umbilical cord (UC) under serum- and xeno-free condition. We found crucial wound healing-mediated growth factors, such as vascular endothelial growth factor A (VEGF-A), fibroblast growth factor 2 (FGF-2), hepatocyte growth factor (HGF), and platelet-derived growth factor BB (PDGF-BB) in exosomes derived from all three MSC sources. However, expression levels of these growth factors in exosomes were influenced by MSC origins, especially transforming growth factor beta (TGF-β) was only detected in UCMSC-derived exosomes. All exosomes released by three MSCs sources induced keratinocyte and fibroblast proliferation and migration; and, the induction of cell migration is a dependent manner with the higher dose of exosomes was used (20 μg), the faster migration rate was observed. Additionally, the influences of exosomes on cell proliferation and migration was associated with exosome origins and also target cells of exosomes that the greatest induction of primary dermal fibroblasts belongs to BMMSC-derived exosomes and keratinocytes belongs to UCMSC-derived exosomes. Data from this study indicated that BMMSCs and UCMSCs under clinical condition secreted exosomes are promising to develop into therapeutic products for wound healing treatment.