Search

Azolla imbircata dry powder (Ai-dp) was prepared by collecting wild Azolla imbircata, drying and grinding. SEM, FTIR and XPS have been used to characterize it. Batch biosorption experiments studied pH, contact time, initial U(VI) concentration, adsorbent dosage and temperature effects on U(VI) biosorption. These results indicated that the maximum biosorption capacity was 4.55 mg L−1 under conditions of 303 K, pH 2.0, initial U(VI) concentration 15 mg L−1 and adsorbent dosage 3.75 g L−1. The biosorption process fit pseudo-second-order kinetics and Langmuir isotherm, it showed the adsorption process was monolayer chemisorption. The thermodynamic fitting results showed the adsorption process was spontaneous and exothermic.

Graphene oxide was encapsulated into sodium alginate to prepare SA-GO composite hydrogel for U(VI) adsorption, which characterized by SEM, FTIR, and XPS. The effects of pH, reaction time, initial U(VI) concentration and adsorbent amount on U(VI) adsorption were studied by batch adsorption experiments. The results showed that the maximum adsorption capacity was 149.76 mg/L when pH 5.0, adsorbent 0.1 g/L, 30 °C and initial U(VI) concentration 15 mg/L. The adsorption process accords with pseudo-second-order kinetic models and Langmuir isotherm. After five cycles of desorption and reuse experiments, the adsorption capacity of SA-GO for U(VI) was still higher than 85%.

The potato early blight was caused by Alternaria solani (Aso). At present, potato early blight resistant varieties are lacking. The experiment of Aso inoculation on a.k.a. Favorita showed that the content of chlorophyll decreased continuously within 2 days after inoculation. In addition, the contents of JA-Ile, SA, ABA and IAA were determined by LC-MS.The results of two defense-related hormones showed that jasmonic acid content decreased significantly, while jasmonic acid content did not change significantly. In order to understand the difference in gene expression of potatoes infected by Aso, the 24 hpi, 36 hpi and 48 hpi transcriptome were determined. The results showed that the gene annotation and cluster analysis of DEGs revealed a variety of defense responses to Aso infection, especially the plant hormone signal transduction pathway. The differential expression of 10 DEGs was confirmed by qPCR analysis. Finally, through weighted gene co-expression network analysis (WGCNA), “samonl” was determined as a key hormone-related network in the process of Aso infection in potatoes. This study provides an important clue for understanding the interaction between potato and Aso and for disease resistance breeding.

Antifungal activities of plant-beneficial Bacillus have been widely studied in recent years. Numerous studies have studied the antifungal mechanisms of soluble non-volatile bioactive compounds such as lipopeptides and proteins produced by Bacillus against soil-borne diseases. However, the antagonistic mechanisms of volatile organic compounds (VOCs) from Bacillus against airborne phytopathogens are still largely unknown, and the function of Alternaria solani pathogenic genes has not been well identified. Here, we first isolated a Bacillus strain with strong antifungal activity and finally identified it as B. subtilis ZD01. Then, the antagonistic mechanisms of VOCs produced by strain ZD01, against A. solani, an airborne fungal pathogen that can cause early blight diseases of potato, were studied. We showed that VOCs produced by strain ZD01 can reduce the colony size and mycelial penetration and can cause serious morphological changes of A. solani. Scanning electron microscope (SEM) observation showed that VOCs released by ZD01 could cause more flaccid and gapped hyphae of A. solani. Also, we found that VOCs produced by ZD01 can inhibit the conidia germination and reduce the lesion areas and number of A. solani in vivo significantly. Meanwhile, based on gas chromatography/mass spectrometry (GC/MS) analysis, 29 volatile compounds produced by strain ZD01 were identified. Out of 29 identified VOCs, 9 VOCs showed complete growth inhibition activities against A. solani. Moreover, we identified two virulence-associated genes (slt2 and sod) in A. solani. slt2 is a key gene that regulates the mycelial growth, penetration, sporulation, and virulence in vivo in A. solani. In addition, sod plays a significant role in the SOD synthetic pathway in A. solani. Results from qRT-PCR showed that the transcriptional expression of these two genes was down-regulated after being treated by VOCs produced by ZD01. These results are useful for a better understanding of the biocontrol mechanism of Bacillus and offer a potential method for potato early blight disease control.

In order to realize the fault diagnosis of planetary gear box, a fault diagnosis system based on Labview is designed. The design scheme of fault diagnosis system is put forward, and the typical fault mechanism and diagnosis principle of planetary gear are revealed. The virtual instrument system is designed. The experimental platform is established to simulate the broken teeth fault of solar gear. The envelope analysis of vibration data is carried out by the developed system. The results show that the system can accurately identify the characteristic frequency of the planetary gear fault and diagnose the fault, which proves that the system is effective and reliable.

Alternaria solani, the causal agent of early blight, is a major threat to global potato production. In recent years, Bacillus species have been widely used for biological control of a wide range of plant pathogens. However, limited knowledge is about the antifungal mechanisms of Bacillus strains against A. solani. Further, the specific antifungal activities of different types of secondary metabolites produced by Bacillus species have not been evaluated comprehensively. In this study, we isolated a Bacillus strain with strong antifungal activity and identified it as B. velezensis C16. The antagonistic mechanisms of non-volatile lipopeptides (LPs) and volatile organic compounds (VOCs) produced by strain C16 against A. solani were studied. The results indicated that LPs and VOCs showed considerable antagonistic activities to A. solani, with reduced colony diameter and significantly inhibited conidia germination. Hyphae treated with antagonistic compounds from C16 exhibited serious structural destruction, with thin or gapped structures and swollen sacs. Active compounds in culture supernatant and volatiles produced by C16 significantly reduced the lesion areas and growth of A. solani in vivo. High-performance liquid chromatography-mass spectrometry (HPLC-MS) and gas chromatography-mass spectrometry (GC-MS) analysis revealed iturins and volatile compounds of C16 that exhibit strong antagonistic activity on mycelia. This study comprehensively investigated the antifungal effects of LPs and VOCs released by strain C16 on the air-borne pathogen A. solani. The results suggest that these compounds exhibit a synergistic effect to resist early blight in potato.

The main challenges for extra low permeability reservoir are injectivity decline and high tubing head pressure (THP) which caused the decreases in hydrocarbon production. The most common causes of deterioration in the reservoir permeability and formation damage include the buildup of in-situ emulsions due to crude oil interaction with drilling and completion fluids, water blockage, asphaltene and paraffin deposition and alteration of near-wellbore wettability. In new wells, near-wellbore formation damage may be caused by emulsion blockages when the whole mud, mud filtrate or completion fluids interact with the formation fluids. Traditional chemical treatments have been widely used to remediate damaged formations for removal of non-aqueous fluid. Various approaches to tackle this problem have been adopted. For example, acid, solvents and mutual solvents have been applied to improve the reservoir permeability, with varying degrees of effectiveness. Microemulsion fluids with unique propertie such as an ultra-low interfacial tension (IFT), high solvency and compatibility with formation fluids has received great interests and shows great potential to effectively remove emulsion blockages, remove precipitated crude oil macromolecules, and reverse wettability to enhance hydrocarbon production. In this paper a new in-situ microemulsion formulation consisting of blend of anionic-cationic surfactants (Sa/c) has been developed to assist the fluid recovery for extra low permeability reservoir at dilute concentrations. Ultra low IFT of 3×10−4 mN/m, solubilization parameters of 18, and ultra low critical micelle concentration of 6.8 mg/L were obtained. Freezing point of crude oil was decreased by 18%, together along with 84.5% viscosity reduction by formation of microemulsion. In addition, wettability alteration was also observed. Lab data shows that the in-situ microemulsion is highly effective in fluid recovery and relative permeability enhancement when applied in stimulation treatments at dilute concentrations. Filed test by using in-situ microemulsion-assisted fluid recovery with Sa/c was tested in super high temperature-extra low permeability formations (reservoir temperature: 116°C, permeability: 4.5 mD) to demonstrate how this novel technology can significantly enhance hydrocarbon production in poorly producing wells.

The initial simulation calculation of the ORC power generation system was carried out using the software Aspen Plus, and the simulation data matched with the design conditions were obtained. According to the specific structure of the evaporator and superheater in the ORC power generation system and the characteristics of the software Aspen EDR, a new simulation calculation method is proposed: structural simulation calculation method. The calculation method and the direct simulation calculation method are used to carry out simulation comparison to find out the regularity of the change of waste heat resources, and it is convenient to further analyze and control the ORC power generation system.

The influence of treatment with an NaAlO2 aqueous solution of NaAlO2 on the surface acid properties of zeolite β was studied as a method to increase the number of both Bronsted and Lewis acid sites. The Hβ samples, prepared by treating with an aqueous solution of NaAlO2, were characterized by XRD, NH3-TPD, pyridine-IR, 29Si MAS NMR, and 27Al MAS NMR. The surface properties of the Hβ zeolite changed after treatment with the aqueous NaAlO2 solution: the number of strong and weak acid sites, the total amount of acid, and the Bronsted and Lewis acid sites increased. The treatment of zeolite β with an aqueous solution of NaAlO2 may realuminate an Si(0Al)A site by the isomorphous substitution of Al(OH)4− anions.

Summary Test results indicate that a lipophilic surfactant can be designed by mixing both hydrophilic anionic and cationic surfactants, which broaden the design of novel surfactant methodology and application scope for conventional chemical enhanced-oil-recovery (EOR) methods. These mixtures produced ultralow critical micelle concentrations (CMCs), ultralow interfacial tension (IFT), and high oil solubilization that promote high tertiary oil recovery. Mixtures of anionic and cationic surfactants with molar excess of anionic surfactant for EOR applications in sandstone reservoirs are described in this study. Physical chemistry properties, such as surface tension, CMC, surface excess, and area per molecule of individual surfactants and their mixtures, were measured by the Wilhelmy (1863) plate method. Morphologies of surfactant solutions, both surfactant/polymer (SP) and alkaline/surfactant/polymer (ASP), were studied by cryogenic-transmission electron microscopy (Cryo-TEM). Phase behaviors were recorded by visual inspection including crossed polarizers at different surfactant concentrations and different temperatures. IFTs between normal octane, crude oil, and surfactant solution were measured by the spinning-drop-tensiometer method. Properties of IFT, viscosity, and thermal stability of surfactant, SP, and ASP solutions were also tested. Static adsorption on sandstone was measured at reservoir temperature. IFT was measured before and after multiple contact adsorptions to recognize the influence of adsorption on interfacial properties. Forced displacements were conducted by flooding with water, SP, and ASP. The coreflooding experiments were conducted with synthetic brine with approximately 5,000 ppm of total dissolved solids (TDS), and with a crude oil from a Sinopec reservoir.

In this paper a new mathematical model of secondary frost heave is presented. It is expected that the problem considered under some assumptions is well-posed.

Background and purpose Coronary chronic total occlusion (CTO) is the last stage of coronary artery atherosclerosis. Percutaneous coronary intervention (PCI) is a therapeutic procedure used to recanalize vessels with total occlusion. However, successful recanalization of CTO is still not optimal, and the key influence factors are still uncertainty. Therefore, a scientific evaluation on the effective of PCI for CTO treatment is necessary. Methods Relevant studies of PCI treatment for CTO were examined. Data were extracted and assessed by two independent clinical experts. Embase, PubMed and Medline et al. were used as database. The main research key words include “CTO”, “PCI”, “Stent”, “Reopen”, “long-term”, “follow-up” and “outcome”. Quality assessment was carried out according to the Cochrane Handbook. The selected data were pooled and analyzed using fixed-effect model and random-effect model. Heterogeneity was assessed using the I2 test, Q test, L’abbe and Galbraith. Comprehensive Meta -Analysis 2.0 and Metanalysis 1.0 were used for statistics analysis in this research. Results A total of 16 articles involving 6695 cases in successful CTO recanalization (CTO success group) and 2370 cases in failed CTO recanalization(CTO failure group) were included in this research. Low CTO success was associated with elder age, previous coronary artery bypass graft surgery (CABG) history, multi-vessel diseases and right coronary artery disease lesion. Six follow-up variables including major adverse cardiac events (MACE), recurrent myocardial infarction (MI), all-cause death, incidence of angina, subsequent CABG and cumulative survival rate were found significantly reduced associated with CTO success. Conclusions Clinical baseline characteristics such as age, previous CABG history and lesion baseline characteristics such as lesion length, multi-vessel diseases might be important factors influencing the successful rate of CTO recanalization. Compared to CTO failure patients, all six follow-up variables showed advantage for CTO success patients.

Objective Ventricular septal defect (VSD) is the most common type of cardiovascular developmental anomaly and is an important risk factor for the substantially increased morbidity and mortality in newborns. Cumulative evidence implicates genetic defects in the pathogenesis of congenital VSD. However, VSD is genetically heterogeneous and the genetic determinants for VSD in most patients remain to be identified. Methods In this study, the whole coding region of the GATA4 gene, which encodes a zinc-finger transcription factor pivotal to cardiogenesis, was initially sequenced in 210 unrelated patients with VSD. The relatives of the index patient carrying the identified mutation and 200 unrelated ethnically matched healthy individuals used as controls were subsequently genotyped. The functional effect of the mutant GATA4 was characterised in contrast to its wild-type counterpart using a luciferase reporter assay system. Results A novel heterozygous GATA4 mutation, p.G296R, was identified in a family with VSD inherited as an autosomal dominant trait. Absent in 200 control individuals, the mutation co-segregated with VSD in the family with 100% penetrance and. was completely conserved evolutionarily across species. Functional analysis displayed that the p.G296R mutation of GATA4 was associated with a decreased transcriptional activity. Conclusion The findings expand the spectrum of mutations in GATA4 linked to VSD and provide more insight into the molecular mechanism involved in VSD. The results of the present study imply the potential implications in the genetic diagnosis and gene-specific therapy of this common malformation in infancy.

Congenital heart disease (CHD) is the commonest form of birth defect in humans and is a leading non-infectious cause of infant death worldwide. Genetic risk factors have been implicated in the pathogenesis of CHD. However, CHD is genetically heterogeneous and the genetic basis underpinning CHD in an

Objective Congenital heart disease (CHD) is the most common birth defect and is the leading cause of infant morbidity and mortality resulted from various birth defects. Increasing evidence demonstrates that genetic variation in the NKX2-5 gene, which encodes a homeobox-containing transcription factor crucial to cardiogenesis, is an important molecular determinant for CHD. Nevertheless, the genetic components underlying CHD in a significant portion of patients remain largely unknown. In this study, we sought to screen NKX2-5 for potential molecular defects in patients with CHD. Methods The entire coding region of NKX2-5 was sequenced initially in a cohort of 268 unrelated patients with CHD. The relatives of the patients carrying identified mutations and 200 unrelated control individuals were subsequently genotyped. Results Three novel heterozygous missense NKX2-5 mutations, p.Q22K, p.R36S, and p.E54K, were identified in 3 families with autosomal dominantly inherited atrial septal defect, ventricular septal defect, and tetralogy of Fallot, respectively. Absent in 200 control individuals, these mutations were highly conserved evolutionarily and co-segregated with CHD in the families with complete penetrance. Conclusion The findings expand the spectrum of mutations in NKX2-5 linked to CHD and provide new insight into the molecular aetiology involved in the pathogenesis of CHD, which signifies potential implications for genetic diagnosis and gene-specific therapy for this common disease in the young.