Realizing stable two-dimensional (2D) Dirac points against spin-orbit coupling (SOC) has attracted much attention because it provides a platform to study the unique transport properties. In previous ...work, Young and Kane Phys. Rev. Lett. 115, 126803 (2015) proposed stable 2D Dirac points with SOC, in which the Berry curvature and edge states vanish due to the coexistence of inversion and time-reversal symmetries. Herein, using the tight-binding model and k·p effective Hamiltonian, we present that 2D Dirac points can survive in the presence of SOC without inversion symmetry. Such 2D Dirac semimetals possess nonzero Berry curvature near the crossing nodes, and two edge states are terminated at one pair of Dirac points. In addition, according to symmetry arguments and high-throughput first-principles calculations, we identify a family of ideal 2D Dirac semimetals, which has nonzero Berry curvature in the vicinity of Dirac points and visible edge states, thus facilitating the experimental observations. Our work shows that 2D Dirac points can emerge without inversion symmetry, which not only enriches the classification of 2D topological semimetals but also provides a promising avenue to observe exotic transport phenomena beyond graphene, e.g., nonlinear Hall effect.
Aim
The aim of this study was to screen potential lotus plant endophytic bacterial isolate for effective inhibition against lotus rot causing fungal pathogen Fusarium oxysporum.
Methods and Results
...In this study, endophytic bacteria were isolated from lotus tissues and tested for antagonistic activities against the pathogenic fungus F. oxysporum. Among the putative endophytic Bacillus strains identified, suspensions of the strain B‐36 showed the highest inhibition rate against F. oxysporum growth. Pot assays indicated that B‐36 was effective in controlling F. oxysporum‐inducing lotus rot. However, the control efficiency varied with the inoculation method and concentration, where injection of 800 μl B‐36 suspension per plant (2 × 108 CFU per ml) into stems showed the highest control efficiencies of 77·1 and 60·0% for pre‐inoculation and post‐inoculation. In addition, the colonizing population levels (CPLs) of B‐36 on lotus also varied with the inoculation method and concentration, with the highest CPLs, that is, 3·05 and 2·83 log(CFU per gram), being observed on lotus leaves and stems respectively for stem injection of 200 μl per plant. Moreover B‐36 showed no noticeable effects on lotus seed germination rate or seedling growth. Finally, B‐36 was characterized as Bacillus velezensis based on its morphology, Gram‐positive characteristics, as well as its 16S rDNA and gyrB sequences.
Conclusion
The isolate B‐36 can be applied as a biocontrol agent against F. oxysporum‐inducing lotus rot.
Significance of Impact of the Study
The soil‐borne fungus F. oxysporum causes lotus rot and severe yield loss, and currently available control methods are very limited. Here we identify a new promising biocontrol agent against lotus rot caused by F. oxysporum.
Using CRISPR/Cas9 delivered as a RNA modality in conjunction with a lipid specifically formulated for large RNA molecules, we demonstrate that homology directed repair (HDR) rates between 20-40% can ...be achieved in induced pluripotent stem cells (iPSC). Furthermore, low HDR rates (between 1-20%) can be enhanced two- to ten-fold in both iPSCs and HEK293 cells by 'cold shocking' cells at 32 °C for 24-48 hours following transfection. This method can also increases the proportion of loci that have undergone complete sequence conversion across the donor sequence, or 'perfect HDR', as opposed to partial sequence conversion where nucleotides more distal to the CRISPR cut site are less efficiently incorporated ('partial HDR'). We demonstrate that the structure of the single-stranded DNA oligo donor can influence the fidelity of HDR, with oligos symmetric with respect to the CRISPR cleavage site and complementary to the target strand being more efficient at directing 'perfect HDR' compared to asymmetric non-target strand complementary oligos. Our protocol represents an efficient method for making CRISPR-mediated, specific DNA sequence changes within the genome that will facilitate the rapid generation of genetic models of human disease in iPSCs as well as other genome engineered cell lines.
In this paper, a direct and simple detection method based on surface-enhanced Raman scattering (SERS) named “heat-induced SERS sensing method” is proposed for rapid determination of glutathione in ...aqueous solutions. It was found that highly enhanced SERS spectra of glutathione can be obtained if the silver colloids adsorbed with the analyte were heated up before the SERS measurement. Besides, it was revealed that silver particles with a size of ∼60 nm are suitable for this study and that the SERS intensity is also influenced by the dropped sample volume, drying temperature, buffer concentration, and pH of the solution. It is noted that the thiol group of glutathione has a particularly strong interaction with a silver surface compared with other small biological molecules without a thiol group, validating this method to detect glutathione selectively. Under the optimal conditions, the detection of glutathione can be finished within 5 min, and the detection limit of ca. 50 nM can be reached, which is much better than the reported detection limit of glutathione (∼1 μM) by SERS. The enhancement factor of the proposed heat-induced SERS sensing method for the detection of glutathione is about 7.5 × 106. The proposed method holds a specific selectivity toward glutathione, facilitating its rapid detection in practical applications.
•Heat storage and retrieval tests in a LTES unit were studied.•Molten salt and metal foam/salt composites were used as the PCMs comparatively.•Thermal non-equilibrium model was established to ...describe the heat transfer characteristics.•Time-duration with composite PCM during heat retrieval process was reduced more.•Slight temperature difference existed between the metal skeleton and PCM.
Eutectic molten salt can be used as the latent thermal energy storage (LTES) medium in solar energy applications. In the present study, eutectic salt (50wt% NaNO3, 50wt% KNO3) with a melting temperature of about 220°C was employed as the PCM for the middle-temperature solar energy application, which can be powered by the parabolic-trough solar collector using oil as the heat transfer fluid. There are many LTES units in which the molten salt is encapsulated in the thermal energy storage tank, where the heat transfer characteristic of the LTES unit is very important for the overall performance of the entire thermal energy storage tank. We experimentally and numerically investigated the heat transfer characteristics of the molten-salt in a LTES unit with and without heat transfer enhancement. Various heating temperatures of 240°C, 250°C, and 260°C and cooling temperatures of 30°C, 70°C, and 110°C were employed in the study, so as to extensively reveal the heat transfer characteristics during heat storage and retrieval. It was found that natural convection was very dominant during heat storage in the case of pure molten-salt, especially when the heating temperature was higher, and it was weakened in the case of molten-salt with metal foam; while the heat retrieval process was enhanced by the presence of the metal foam. The numerical results were compared with the experimental results, showing reasonable agreement, which indicated that such numerical model could be used for the further study of the performance of the LTES system.
•The laminate acoustic metamaterials with multi-stopband for structural-acoustic coupled system are proposed.•Numerical results reveal that two bandgaps are generated around the absorbers’ resonant ...frequency.•The excellent performance of NVH using laminate acoustic metamaterials has been clearly verified.
This paper designs the laminate acoustic metamaterials with multi-stopband for structural-acoustic coupled system. The laminate acoustic metamaterials are composed of carbon-fiber-reinforced polymer (CFRP) and a periodic array of two degrees of freedom (2-DOF) mass-spring-damper subsystems attached to the laminate. According to the dispersion analysis, two stopbands are observed around the absorbers’ resonant frequency. Based on the finite element modeling, the multi-stopband behavior has been confirmed. In addition, the effects of damping of vibration absorbers are discussed in this work. By adding the appropriate damping to the vibration absorbers, the two stop bands can be combined into a wider stopband. Subsequently, the analyses of multi-stopband laminate acoustic metamaterials in the structural–acoustic coupled system are performed. The excellent performance of multi-stopband laminate acoustic metamaterials has been applied to the front panel of vehicle, and the noise of passenger compartment cavity is reduced significantly.
Recent large-scale genetic approaches such as genome-wide association studies have allowed the identification of common genetic variations that contribute to risk architectures of psychiatric ...disorders. However, most of these susceptibility variants are located in noncoding genomic regions that usually span multiple genes. As a result, pinpointing the precise variant(s) and biological mechanisms accounting for the risk remains challenging. By reviewing recent progresses in genetics, functional genomics and neurobiology of psychiatric disorders, as well as gene expression analyses of brain tissues, here we propose a roadmap to characterize the roles of noncoding risk loci in the pathogenesis of psychiatric illnesses (that is, identifying the underlying molecular mechanisms explaining the genetic risk conferred by those genomic loci, and recognizing putative functional causative variants). This roadmap involves integration of transcriptomic data, epidemiological and bioinformatic methods, as well as in vitro and in vivo experimental approaches. These tools will promote the translation of genetic discoveries to physiological mechanisms, and ultimately guide the development of preventive, therapeutic and prognostic measures for psychiatric disorders.
Two polyurethanases PueA and PueB from Pseudomonas protegens Pf‐5 have been reported to have hydrolytic activity against synthetic p‐nitrophenyl palmitate of lipase substrate, and PueA may play a ...more effective role in this activity. However, it is still unknown whether PueA and PueB play similar parts in the lipase activity against natural acylglycerols and achieve the extracellular secretion via their cognate ABC exporter AprDEF. In this study, we investigated these questions through the construction of four markerless deletion mutants in Pf5139 (Δupp derivative of Pf‐5), two heterologous co‐expression strains and their three control strains in lipase‐free Escherichia coli BL21(DE3), and detected their lipase activities by the tributyrin plate assay and the liquid culture assay. The results showed that PueA and PueB, classified as subfamily I.3 lipases, are major extracellular lipases involved in the uptake of oil in Pf‐5, and PueA plays a leading role in extracellular lipase activity. In addition, the extracellular secretion of PueA and PueB can be partly mediated via AprDEF in Pf‐5 and BL21(DE3). Finally, PueA and PueB are also able to achieve the extracellular secretion without the assistance of AprDEF in Pf‐5 and BL21(DE3).
Significance and Impact of the Study: We investigated the additional function of two polyurethanases PueA and PueB from Pseudomonas protegens Pf‐5, and demonstrated that they are major extracellular lipases that belong to the members of subfamily I.3 lipases, involved in the uptake of oil in Pf‐5, of which PueA plays a more important role in extracellular lipase activity. Furthermore, their cognate ABC exporter AprDEF can partly mediate the extracellular secretion of PueA and PueB in Pf‐5 and heterologous Escherichia coli BL21(DE3). Lastly, PueA and PueB can also be secreted into the extracellular environment without the help of their cognate AprDEF in Pf‐5 and BL21(DE3).
Summary
Background
Acne inversa (AI) is a chronic inflammatory skin disease with an autosomal dominant inheritance pattern. Mutations of the gene encoding nicastrin (NCSTN), a cofactor subunit of ...γ‐secretase, are responsible for familial AI. However, whether deficiency of nicastrin is functionally implicated in the biological behaviours of human keratinocytes and related molecular mechanisms remains unknown.
Objectives
To study alterations of biological traits and related signalling pathways modulated by nicastrin knockdown in keratinocytes.
Methods
A human immortalized keratinocyte cell line (HaCaT) was treated with efficient small interfering (si)RNA‐targeted NCSTN. Cell proliferation was measured by CCK‐8 assay; cell‐cycle and cell apoptosis analyses were detected by flow cytometry. Microarray analysis was applied to uncover impacts of NCSTN silencing on whole‐genome expression of HaCaT cells. Altered signalling pathways were further confirmed by real‐time polymerase chain reaction, Western blotting and immunohistochemistry in both HaCaT cells and lesions of a patient with AI with NCSTN mutation.
Results
NCSTN knockdown in HaCaT cells impaired γ‐secretase activity, leading to increased cell proliferation and S‐phase population. Microarray data also showed that numerous genes and pathways implicated in proliferation and differentiation of keratinocytes were statistically changed. Among these genes, expression levels of several Notch pathway molecules, known as γ‐secretase substrates, were validated to be significantly attenuated in both nicastrin‐silencing HaCaT cells and the lesion of the patient. Furthermore, a remarkable elevation of expression of phosphoinositide 3‐kinase (PI3K), AKT and its activated form pAKT was illustrated in siRNA‐treated HaCaT cells.
Conclusions
Deficiency of the NCSTN in familial AI may regulate proliferation and differentiation of keratinocytes mainly through the Notch and PI3K/AKT signalling pathways.
What's already known about this topic?
Acne inversa is a chronic inflammatory skin disease showing an autosomal dominant inheritance pattern.
Mutations of the gene encoding nicastrin, a cofactor subunit of the γ‐secretase complex, are responsible for familial acne inversa.
What does this study add?
This is the first identification of alterations of whole‐genome expression upon nicastrin knockdown in keratinocytes.
Loss of function of the nicastrin gene in familial acne inversa may affect proliferation and differentiation of keratinocytes mainly through the Notch and phosphoinositide 3‐kinase/AKT signalling pathways.
Linked Comment: Frew. Br J Dermatol 2016; 174: 484–485.
To evaluate lung cancer histology type using computed tomography (CT) spectral quantitative parameters combining with serum tumour markers.
Patients with suspicious lung cancer underwent CT spectral ...imaging and serum tumour markers. CT spectral quantitative parameters including attenuation value, the slope of spectral curve (λ), iodine concentration, water concentration, and effective atomic number (Zeff) were acquired. Serum levels of tumour markers including carcinoembryonic antigen (CEA), neuron-specific enolase (NSE), squamous cell carcinoma antigen (SCC-Ag), and cytokeratin fragment CYFRA21-1 were also obtained. All the values were compared among different histological types of lung cancer. The diagnostic efficiencies of serum tumour markers, CT spectral parameters, and a combination of them were computed by statistical analysis.
CEA and NSE levels were higher in adenocarcinoma and neuroendocrine tumour, respectively, while SCC-Ag and CYFRA21-1 levels were higher in squamous cell cancer. There was no significant difference in attenuation among the groups (p>0.05), whereas λ in the arterial phase, and Zeff and IC in both the arterial and venous phases were significantly different among groups (p<0.05). According to the area under the receiver operating characteristic (ROC) curve (AUC) and Youden's index, the diagnostic efficiency of serum tumour markers were higher than that of CT spectral parameters. Moreover, AUCs of combined serum and CT indicators were larger than that of combined serum markers and combined CT spectral parameters between squamous cell cancer and adenocarcinoma as well as between squamous cell cancer and neuroendocrine tumour.
CT spectral quantitative parameters and serum tumour markers are valuable in evaluating histological types of lung cancer. In combination they can significantly improve diagnostic efficiency.
•Histological type of lung cancer is essential for clinical management.•Noninvasive examination is valuable for histological diagnosis of lung cancer.•Serum tumour markers have high specificity for the histological type of lung cancer.•CT spectral imaging can provide multiple quantitative parameters for evaluation.•Combination of spectral CT and serum markers can improve diagnostic efficiency.
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