Explore the vast range of titles available.

The nonlinear Hall effect is an unconventional response, in which a voltage can be driven by two perpendicular currents in the Hall-bar measurement. Unprecedented in the family of the Hall effects, it can survive time-reversal symmetry but is sensitive to the breaking of discrete and crystal symmetries. It is a quantum transport phenomenon that has deep connection with the Berry curvature. However, a full quantum description is still absent. Here we construct a quantum theory of the nonlinear Hall effect by using the diagrammatic technique. Quite different from nonlinear optics, nearly all the diagrams account for the disorder effects, which play decisive role in the electronic transport. After including the disorder contributions in terms of the Feynman diagrams, the total nonlinear Hall conductivity is enhanced but its sign remains unchanged for the 2D tilted Dirac model, compared to the one with only the Berry curvature contribution. We discuss the symmetry of the nonlinear conductivity tensor and predict a pure disorder-induced nonlinear Hall effect for point groups C 3 , C 3 h , C 3 v , D 3 h , D 3 in 2D, and T , T d , C 3 h , D 3 h in 3D. This work will be helpful for explorations of the topological physics beyond the linear regime. The nonlinear Hall effect is a quantum phenomenon, in which two perpendicular currents induce a Hall voltage; however, previous theories for this effect has remained at the semi classical level. Here, the authors develop a full quantum theory of the nonlinear Hall effect by using the diagrammatic technique.

Phosphorus (P) is an essential element to all living cells, yet fluctuations in P concentrations are recurrent in the marine environment. Diatoms are amongst the most successful phytoplankton groups, adapting to and surviving periods of suboptimal conditions and resuming growth as soon as nutrient concentrations permit. A knowledge of the molecular underpinnings of diatom ecological success is, however, still very incomplete. By strand‐specific RNA sequencing, we analyzed the global transcriptome changes of the diatom Phaeodactylum tricornutum in response to P fluctuations over a course of 8 d, defining five distinct physiological states. This study reports previously unidentified genes highly responsive to P stress in P. tricornutum. Our data also uncover the complexity of the P. tricornutum P‐responsive sensory and signaling system that combines bacterial two‐component systems with more complex pathways reminiscent of metazoans. Finally, we identify a multitude of novel long intergenic nonprotein coding RNAs (lincRNAs) specifically responsive to P depletion, suggesting putative regulatory roles in the regulation of P homeostasis. Our work provides additional molecular insights into the resilience of diatoms and their ecological success, and opens up novel routes to address and explore the function and regulatory roles of P. tricornutum lincRNAs in the context of nutrient stress.

Periodontitis is a widespread disease characterized by inflammation‐induced progressive damage to the tooth‐supporting structures until tooth loss occurs. The regeneration of lost/damaged support tissue in the periodontium, including the alveolar bone, periodontal ligament, and cementum, is an ambitious purpose of periodontal regenerative therapy and might effectively reduce periodontitis‐caused tooth loss. The use of stem cells for periodontal regeneration is a hot field in translational research and an emerging potential treatment for periodontitis. This concise review summarizes the regenerative approaches using either culture‐expanded or host‐mobilized stem cells that are currently being investigated in the laboratory and with preclinical models for periodontal tissue regeneration and highlights the most recent evidence supporting their translational potential toward a widespread use in the clinic for combating highly prevalent periodontal disease. We conclude that in addition to in vitro cell‐biomaterial design and transplantation, the engineering of biomaterial devices to encourage the innate regenerative capabilities of the periodontium warrants further investigation. In comparison to cell‐based therapies, the use of biomaterials is comparatively simple and sufficiently reliable to support high levels of endogenous tissue regeneration. Thus, endogenous regenerative technology is a more economical and effective as well as safer method for the treatment of clinical patients. Stem Cells Translational Medicine 2019;8:392–403 Periodontal regeneration can potentially be achieved via either the in vitro design of cell‐material constructs that may undergo remodeling and revascularization to integrate with the host tissue following transplantation or based on the in vivo manipulation of the cell‐material interplay at the target site to recruit endogenous stem cells to regenerate new tissues.

The plant immune response is a complex process involving transcriptional and posttranscriptional regulation of gene expression. Responses to plant immunity are initiated upon the perception of pathogen-associated molecular patterns, including peptide fragment of bacterial flagellin (flg22) or translation elongation factor Tu (elf18). Here, we identify an Arabidopsis thaliana long-noncoding RNA, designated ELF18-INDUCED LONG-NONCODING RNA1 (ELENA1), as a factor enhancing resistance against Pseudomonas syringe pv tomato DC3000. ELENA1 knockdown plants show decreased expression of PATHOGENESIS-RELATED GENE1 (PR1) and the plants are susceptible to pathogens. By contrast, plants overexpressing ELENA1 show elevated PR1 expression after elf18 treatment and display a pathogen resistance phenotype. RNA-sequencing analysis of ELENA1-overexpressing plants after elf18 treatment confirms increased expression of defenserelated genes compared with the wild type. ELENA1 directly interacts with Mediator subunit 19a (MED19a) and affects enrichment of MED19a on the PR1 promoter. These results show that MED19a regulates PR1 expression through ELENA1. Our findings uncover an additional layer of complexity, implicating long-noncoding RNAs in the transcriptional regulation of plant innate immunity.

The effects of mesenchymal stem cells (MSC) on the growth and metastasis of human malignancies including hepatocellular carcinoma (HCC) are controversial, and the underlying mechanisms are not yet understood. The aim of this study was to explore the role of MSC in the progression of HCC. We investigated the effect of MSC on in vitro proliferation and invasion and in vivo tumor growth and pulmonary metastasis of MHCC97‐H HCC cells with a high metastatic potential. The mRNA and protein levels of transforming growth factor‐beta 1 (TGFβ1) and MMP, and their association with the effects of MSC on HCC cells were also evaluated. Co‐culture of MHCC97‐H cells with MSC conditioned medium significantly enhanced in vitro proliferation but inhibited invasiveness. Following MSC treatment of a nude mouse model bearing human HCC, the MSC were predominantly located in the HCC tissues. Compared with controls, MSC‐treated mice exhibited significantly larger tumors (3080.51 ± 1234.78 mm3vs 2223.75 ± 1000.60 mm3, P = 0.045), but decreased cellular numbers of lung metastases (49.75 ± 18.86 vs 227.22 ± 74.67, P = 0.046). Expression of TGFβ1 and MMP‐2 was significantly downregulated in the MSC‐treated HCC cells. TGFβ siRNA concurrently downregulated expression of TGFβ and MMP‐2 in HCC cells and blocked the MSC‐induced proliferation and invasiveness of MHCC97‐H cells. The MSC enhanced tumor growth but significantly inhibited the invasiveness and metastasis of HCC, possibly through downregulation of TGFβ1. These findings suggest that MSC could be useful in controlling metastatic recurrence of HCC. (Cancer Sci 2010; 101: 2546–2553)

Endothelial cells are important constituents of blood vessels that play critical roles in cardiovascular homeostasis by regulating blood fluidity and fibrinolysis, vascular tone, angiogenesis, monocyte/leukocyte adhesion, and platelet aggregation. The normal vascular endothelium is taken as a gatekeeper of cardiovascular health, whereas abnormality of vascular endothelium is a major contributor to a plethora of cardiovascular ailments, such as atherosclerosis, aging, hypertension, obesity, and diabetes. Endothelial dysfunction is characterized by imbalanced vasodilation and vasoconstriction, elevated reactive oxygen species (ROS), and proinflammatory factors, as well as deficiency of nitric oxide (NO) bioavailability. The occurrence of endothelial dysfunction disrupts the endothelial barrier permeability that is a part of inflammatory response in the development of cardiovascular diseases. As such, abrogation of endothelial cell activation/inflammation is of clinical relevance. Recently, hydrogen sulfide (H S), an entry as a gasotransmitter, exerts diverse biological effects through acting on various targeted signaling pathways. Within the cardiovascular system, the formation of H S is detected in smooth muscle cells, vascular endothelial cells, and cardiomyocytes. Disrupted H S bioavailability is postulated to be a new indicator for endothelial cell inflammation and its associated endothelial dysfunction. In this review, we will summarize recent advances about the roles of H S in endothelial cell homeostasis, especially under pathological conditions, and discuss its putative therapeutic applications in endothelial inflammation-associated cardiovascular disorders.

Background Cold is a major abiotic stress and Huanglongbing and citrus canker disease are two devastating bacterial diseases for citrus. The Ca 2+ -CBL-CIPK network is known to regulate different types of stress signalling in plants. How do CBL–CIPK signalling networks function in response to cold and infection by C Las or Xcc in citrus? Results Eight calcineurin B-like proteins (CBLs) and seventeen CBL-interacting protein kinases (CIPKs) were identified from the cold-tolerant satsuma mandarin ‘Guijing2501’ ( Citrus. unshiu ) and C Las/ Xcc -sensitive sweet orange ( C. sinensis ). Phylogenetic analysis revealed that both CBL and CIPK family members in citrus were classified into an ancient and a recent clade according to their conserved domain characteristics and/or intron/exon structures. Genome duplication analysis suggested that both tandem and segmental duplications contributed to the amplification of the CBL and CIPK gene families in citrus under intense purifying selection, and the duplication events only existed in the recent clades. Expression comparison of the duplicated gene pairs indicated that the duplicated CBL and CIPK genes underwent functional differentiation. Further expression analysis identified that CBL1 , 5 , 6 , and 8 and CIPK2 , 8 , 12 , 15 , 16 , and 17 were significantly regulated by multiple stresses, including cold, Xcc infection and/or C Las infection, in citrus, whereas CBL2 / 7 and CIPK1/4/5/11 / 13 / 14 were independently highly regulated by cold and CIPK3 was uniquely responsive to Xcc infection. The combination analyses of targeted Y2H assay and expression analysis revealed that CBL6-CIPK8 was the common signalling network in response to cold and Xcc infection, while CBL6/CBL8-CIPK14 was uniquely responsive to cold in citrus. Further stable transformation and cold tolerance assay indicated that overexpression of CuCIPK16 enhanced the cold tolerance of transgenic Arabidopsis with higher POD activity and lower MDA content. Conclusions In this study, evolution, gene expression and protein‒protein interaction analyses of citrus CBLs and CIPKs were comprehensively conducted over a genome-wide range. The results will facilitate future functional characterization of individual citrus CBLs and CIPKs under specific stresses and provide clues for the clarification of cold tolerance and disease susceptibility mechanisms in corresponding citrus cultivars.

In this paper, we reformulate the coupled nonlinear Schrödinger (CNLS) equation by using the scalar auxiliary variable (SAV) approach and solve the resulting system by using Crank-Nicolson finite element method. The fully-discrete method is proved to be mass- and energy-conserved. However, if the convergence results are investigated by using the classical way, the presence of u t and v t in the equation of r ′ ( t ) may lead to not only a consistency error of sub-optimal order in time but also some difficulties in analysing the numerical stability. The mentioned difficulties are overcome technically by estimating the difference quotient of the error in the H - 1 -norm and carefully analysising the connections of errors between the couple systems. Consequently, the numerical solution is shown to be convergent at the order of O ( τ 2 + h p ) in the H 1 -norm with time step τ , mesh size h and the degree of finite elements p . Several numerical examples are presented to confirm our theoretical results.

Propofol, a commonly used intravenous anesthetic during cancer resection surgery, has been found to exhibit tumor inhibitory effects in vitro and in vivo. The role of propofol in lung cancer has been previously reported, whereas its action mechanism remains unclear. This study further investigated the effects of propofol on lung cancer A549 cell growth, migration and invasion, as well as the underlying mechanisms. Cell viability, proliferation, migration, invasion and apoptosis were assessed by CCK-8 assay, BrdU assay, two chamber transwell assay and flow cytometry, respectively. The regulatory effect of propofol on microRNA-372 (miR-372) expression in A549 cells was analyzed by qRT-PCR. Cell transfection was used to change the expression of miR-372. The protein expression of key factors involving in cell proliferation, apoptosis, migration and invasion, as well as Wnt/β-catenin and mTOR pathways were analyzed by western blotting. Propofol inhibited lung cancer A549 cell viability, proliferation, migration, and invasion, but promoted cell apoptosis. Moreover, miR-372 was down-regulated in propofol-treated A549 cells. Overexpression of miR-372 abrogated the effects of propofol on proliferation, migration, invasion and apoptosis of A549 cells. Knockdown of miR-372 had opposite effects. Furthermore, propofol suppressed Wnt/β-catenin and mTOR signaling pathways by down-regulating miR-372. Propofol inhibits growth, migration and invasion of lung cancer A549 cells at least in part by down-regulating miR-372 and then inactivating Wnt/β-catenin and mTOR pathways.

Root zone microbial structure is particularly complex in plants with rhizosheaths, and greater understanding of the rhizosheath may play an important role in the future development of sustainable agricultural practices. However, one important reason to focus study on rhizosheath microbial structure is that there is no definite method for rhizosheath separation. The aim of this study was to explore rhizosheath isolation methods and the diversity characteristics of microorganisms around the rhizosphere. In this study, we isolated the rhizosheath of Stipa grandis , a dominant species in desert steppe, and the microorganisms in the roots, root epidermis, rhizosheath and rhizosphere soil were extracted and sequenced by 16S rRNA and ITS. The alpha diversity index of bacteria in Stipa grandis rhizosphere soil was the greatest, followed by rhizosheath, and the alpha diversity index of endophytic bacteria in root system was the smallest. The alpha diversity index of fungi in the rhizosheath and rhizosphere soil were significantly higher than that in the root epidermis and root system. There were significant differences in bacterial community structure between the root epidermis, endophytic bacteria, rhizosheath and rhizosphere soil. Unlike bacterial community structure, the community structure of fungi in the root epidermis was similar that of endophytic fungi, but significantly different from those in rhizosheath and rhizosphere soil. This study demonstrated a feasible method for separating plant rhizosheath and root epidermis. We suggest that the root epidermis can act as the interface between the host plant root and the external soil environment. We will have to re-examine the biological and ecological significance of rhizosheath and microorganisms in rhizosheath, as well as the mechanism explaining the close relationship of the rhizosheath and the plant root epidermis. This study provides theoretical and technical guidance for the isolation of the plant rhizosheath and the study of microorganisms in plant rhizosheath.