1,793 research outputs found
Femtosecond control of electric currents at the interfaces of metallic ferromagnetic heterostructures
The idea to utilize not only the charge but also the spin of electrons in the
operation of electronic devices has led to the development of spintronics,
causing a revolution in how information is stored and processed. A novel
advancement would be to develop ultrafast spintronics using femtosecond laser
pulses. Employing terahertz (10 Hz) emission spectroscopy, we
demonstrate optical generation of spin-polarized electric currents at the
interfaces of metallic ferromagnetic heterostructures at the femtosecond
timescale. The direction of the photocurrent is controlled by the helicity of
the circularly polarized light. These results open up new opportunities for
realizing spintronics in the unprecedented terahertz regime and provide new
insights in all-optical control of magnetism.Comment: 3 figures and 2 tables in the main tex
Activity of Bdellovibrio Hit Locus Proteins, Bd0108 and Bd0109, Links Type IVa Pilus Extrusion/Retraction Status to Prey-Independent Growth Signalling
Bdellovibrio bacteriovorus are facultatively predatory bacteria that grow within gram-negative prey, using pili to
invade their periplasmic niche. They also grow prey-independently on organic nutrients after undergoing a reversible
switch. The nature of the growth switching mechanism has been elusive, but several independent reports suggested
mutations in the hit (host-interaction) locus on the Bdellovibrio genome were associated with the transition to preyindependent
growth. Pili are essential for prey entry by Bdellovibrio and sequence analysis of the hit locus predicted
that it was part of a cluster of Type IVb pilus-associated genes, containing bd0108 and bd0109. In this study we have
deleted the whole bd0108 gene, which is unique to Bdellovibrio, and compared its phenotype to strains containing
spontaneous mutations in bd0108 and the common natural 42 bp deletion variant of bd0108. We find that deletion of
the whole bd0108 gene greatly reduced the extrusion of pili, whereas the 42 bp deletion caused greater pilus
extrusion than wild-type. The pili isolated from these strains were comprised of the Type IVa pilin protein; PilA.
Attempts to similarly delete gene bd0109, which like bd0108 encodes a periplasmic/secreted protein, were not
successful, suggesting that it is likely to be essential for Bdellovibrio viability in any growth mode. Bd0109 has a
sugar binding YD- repeat motif and an N-terminus with a putative pilin-like fold and was found to interact directly with
Bd0108. These results lead us to propose that the Bd0109/Bd0108 interaction regulates pilus production in
Bdellovibrio (possibly by interaction with the pilus fibre at the cell wall), and that the presence (and possibly retraction
state) of the pilus feeds back to alter the growth state of the Bdellovibrio cell. We further identify a novel small RNA
encoded by the hit locus, the transcription of which is altered in different bd0108 mutation background
Prevention of gastrointestinal cancer by surveillance endoscopy
The classification of the endoscopic appearance of superficial neoplastic lesions of the digestive mucosa aims to evaluate the risk of progression to advanced neoplasia in 3° (low, intermediate, high) and to predict appropriate treatment and corresponding surveillance. The privileged position of endoscopy results from its double impact on prevention of digestive cancer through reduction in incidence after early detection and eradication of precursors; and through reduction of mortality after detection and treatment of cancer at an early and curable stage. However the efficacy of diagnostic endoscopy still requires improvement and quality control on the following points: (1) technology, with a generalized use of the recently introduced high-resolution endoscopes. (2) diagnosis of poorly visible nonpolypoid precursors: this applies to small depressed lesions and large slightly elevated or sessile serrated and non-serrated precursors, particularly in the proximal colon. (3) treatment and training in therapeutic endoscopy, including the most recent techniques of mucosal resection of nonpolypoid lesions
Small molecule sensitization to TRAIL is mediated via nuclear localization, phosphorylation and inhibition of chaperone activity of Hsp27
10.1038/cddis.2013.413Cell Death and Disease410
Six-dimensional (1,0) effective action of F-theory via M-theory on Calabi-Yau threefolds
The six-dimensional effective action of F-theory compactified on a singular
elliptically fibred Calabi-Yau threefold is determined by using an M-theory
lift. The low-energy data are derived by comparing a circle reduction of a
general six-dimensional (1,0) gauged supergravity theory with the effective
action of M-theory on the resolved Calabi-Yau threefold. The derivation
includes six-dimensional tensor multiplets for which the (anti-) self-duality
constraints are imposed on the level of the five-dimensional action. The vector
sector of the reduced theory is encoded by a non-standard potential due to the
Green-Schwarz term in six dimensions. This Green-Schwarz term also contains
higher curvature couplings which are considered to establish the full map
between anomaly coefficients and geometry. F-/M-theory duality is exploited by
moving to the five-dimensional Coulomb branch after circle reduction and
integrating out massive vector multiplets and matter hypermultiplets. The
associated fermions then generate additional Chern-Simons couplings at
one-loop. Further couplings involving the graviphoton are induced by quantum
corrections due to excited Kaluza-Klein modes. On the M-theory side integrating
out massive fields corresponds to resolving the singularities of the Calabi-Yau
threefold, and yields intriguing relations between six-dimensional anomalies
and classical topology.Comment: 55 pages, v2: typos corrected, discussion of loop corrections
improve
Impact of socioeconomic deprivation on rate and cause of death in severe mental illness
Background:
Socioeconomic status has important associations with disease-specific mortality in the general population. Although individuals with Severe Mental Illnesses (SMI) experience significant premature mortality, the relationship between socioeconomic status and mortality in this group remains under investigated.<p></p>
Aims:
To assess the impact of socioeconomic status on rate and cause of death in individuals with SMI (schizophrenia and bipolar disorder) relative to the local (Glasgow) and wider (Scottish) populations.<p></p>
Methods:
Cause and age of death during 2006-2010 inclusive for individuals with schizophrenia or bipolar disorder registered on the Glasgow Psychosis Clinical Information System (PsyCIS) were obtained by linkage to the Scottish General Register Office (GRO). Rate and cause of death by socioeconomic status, measured by Scottish Index of Multiple Deprivation (SIMD), were compared to the Glasgow and Scottish populations.<p></p>
Results:
Death rates were higher in people with SMI across all socioeconomic quintiles compared to the Glasgow and Scottish populations, and persisted when suicide was excluded. Differences were largest in the most deprived quintile (794.6 per 10,000 population vs. 274.7 and 252.4 for Glasgow and Scotland respectively). Cause of death varied by socioeconomic status. For those living in the most deprived quintile, higher drug-related deaths occurred in those with SMI compared to local Glasgow and wider Scottish population rates (12.3% vs. 5.9%, p = <0.001 and 5.1% p = 0.002 respectively). A lower proportion of deaths due to cancer in those with SMI living in the most deprived quintile were also observed, relative to the local Glasgow and wider Scottish populations (12.3% vs. 25.1% p = 0.013 and 26.3% p = <0.001). The proportion of suicides was significantly higher in those with SMI living in the more affluent quintiles relative to Glasgow and Scotland (54.6% vs. 5.8%, p = <0.001 and 5.5%, p = <0.001).
Discussion and conclusions:
Excess mortality in those with SMI occurred across all socioeconomic quintiles compared to the Glasgow and Scottish populations but was most marked in the most deprived quintiles when suicide was excluded as a cause of death. Further work assessing the impact of socioeconomic status on specific causes of premature mortality in SMI is needed
Connecting the dots: Potential of data integration to identify regulatory snps in late-onset alzheimer's disease GWAS findings
Late-onset Alzheimer's disease (LOAD) is a multifactorial disorder with over twenty loci associated with disease risk. Given the number of genome-wide significant variants that fall outside of coding regions, it is possible that some of these variants alter some function of gene expression rather than tagging coding variants that alter protein structure and/or function. RegulomeDB is a database that annotates regulatory functions of genetic variants. In this study, we utilized RegulomeDB to investigate potential regulatory functions of lead single nucleotide polymorphisms (SNPs) identified in five genome-wide association studies (GWAS) of risk and age-at onset (AAO) of LOAD, as well as SNPs in LD (r2≥0.80) with the lead GWAS SNPs. Of a total 614 SNPs examined, 394 returned RegulomeDB scores of 1-6. Of those 394 variants, 34 showed strong evidence of regulatory function (RegulomeDB score ,3), and only 3 of them were genome-wide significant SNPs (ZCWPW1/ rs1476679, CLU/rs1532278 and ABCA7/rs3764650). This study further supports the assumption that some of the non-coding GWAS SNPs are true associations rather than tagged associations and demonstrates the application of RegulomeDB to GWAS data.©2014 Rosenthal et al
Significance of glycolytic metabolism-related protein expression in colorectal cancer, lymph node and hepatic metastasis
Background: Colorectal cancer (CRC) is one of the most common malignancies and a leading cause of cancer death worldwide. Most cancer cells display high rates of glycolysis with production of lactic acid, which is then exported to the microenvironment by monocarboxylate transporters (MCTs). The main aim of this study was to evaluate the significance of MCT expression in a comprehensive series of primary CRC cases, lymph node and hepatic metastasis.
Methods: Expressions of MCT1, MCT4, CD147 and GLUT1 were studied in human samples of CRC, lymph node and hepatic metastasis, by immunohistochemistry.
Results: All proteins were overexpressed in primary CRC, lymph node and hepatic metastasis, when compared with non-neoplastic tissue, with exception of MCT1 in lymph node and hepatic metastasis. MCT1 and MCT4 expressions were associated with CD147 and GLUT1 in primary CRC. These markers were associated with clinical pathological features, reflecting the putative role of these metabolism-related proteins in the CRC setting.
Conclusion: These findings provide additional evidence for the pivotal role of MCTs in CRC maintenance and progression, and support the use of MCTs as biomarkers and potential therapeutic targets in primary and metastatic CRC.This work was supported by the Fundação para a Ciência e a Tecnologia
(FCT) grant ref. PTDC/SAU-FCF/104347/2008, under the scope of ‘Programa
Operacional Temático Factores de Competitividade’ (COMPETE) of ‘Quadro
Comunitário de Apoio III’ and co-financed by the Fundo Europeu De Desenvolvimento
Regional (FEDER). Ricardo Amorim was recipient of the fellowship
SFRH/BD/98002/2013, from Fundação para a Ciência e a Tecnologia (FCT
Portugal).info:eu-repo/semantics/publishedVersio
Role of monocarboxylate transporters in human cancers : state of the art
Monocarboxylate transporters (MCTs) belong to the SLC16 gene family, presently composed by 14 members. MCT1-MCT4 are proton symporters, which mediate the transmembrane transport of pyruvate, lactate and ketone bodies. The role of MCTs in cell homeostasis has been characterized in detail in normal tissues, however, their role in cancer is still far from understood. Most solid tumors are known to rely on glycolysis for energy production and this activity leads to production of important amounts of lactate, which are exported into the extracellular milieu, contributing to the acidic microenvironment. In this context, MCTs will play a dual role in the maintenance of the hyper-glycolytic acidresistant phenotype of cancer, allowing the maintenance of the high glycolytic rates by performing lactate efflux, and pH regulation by the co-transport of protons. Thus, they constitute attractive targets for cancer therapy, which have been little explored. Here we review the literature on the role of MCTs in solid tumors in different locations, such as colon, central nervous system, breast, lung, gynecologic tract, prostate, stomach, however, there are many conflicting results and in most cases there are no functional studies showing the dependence of the tumors on MCT expression and activity. Additional studies on MCT expression in other tumor types, confirmation of the results already published as well as additional functional studies are needed to deeply understand the role of MCTs in cancer maintenance and aggressiveness
Buprenorphine-Naloxone in the Treatment of Codeine Dependence: a Scoping Review of Clinical Case Presentations
Misuse of prescribed and over the counter (OTC) codeine containing medicines is an increasing public health concern in recent times. Studies have called for low threshold treatment services for individuals experiencing codeine dependence using buprenorphine naloxone therapy. We present a scoping review of clinical case presentation literature on the use of buprenorphine-naloxone in the treatment of codeine dependence. Seven records (four single case studies and three case series) on codeine dependence treated with buprenorphine-naloxone were included. Five themes emerged following a review of the cases for the treatment of codeine dependence with buprenorphine-naloxone. They are: (1) Patient Profiles; (2) History of Codeine Misuse; (3) Medical Problems; (4) Use of Other Substances; and (5) Buprenorphine-naloxone in the treatment of Codeine Dependence. The review highlights the complexities of patients with regards to pain, psychiatric illness, poly substance use and iatrogenic dependence, with findings encouraging in terms of patient stabilisation and recovery
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