108 research outputs found
High On/Off Ratio Graphene Nanoconstriction Field Effect Transistor
We report a method to pattern monolayer graphene nanoconstriction field
effect transistors (NCFETs) with critical dimensions below 10 nm. NCFET
fabrication is enabled by the use of feedback controlled electromigration (FCE)
to form a constriction in a gold etch mask that is first patterned using
conventional lithographic techniques. The use of FCE allows the etch mask to be
patterned on size scales below the limit of conventional nanolithography. We
observe the opening of a confinement-induced energy gap as the NCFET width is
reduced, as evidenced by a sharp increase in the NCFET on/off ratio. The on/off
ratios we obtain with this procedure can be larger than 1000 at room
temperature for the narrowest devices; this is the first report of such large
room temperature on/off ratios for patterned graphene FETs.Comment: 18 pages, 6 figures, to appear in Smal
Graphene-protein bioelectronic devices with wavelength-dependent photoresponse
We implemented a nanoelectronic interface between graphene field effect
transistors (FETs) and soluble proteins. This enables production of
bioelectronic devices that combine functionalities of the biomolecular and
inorganic components. The method serves to link polyhistidine-tagged proteins
to graphene FETs using the tag itself. Atomic Force Microscopy and Raman
spectroscopy provide structural understanding of the bio/nano hybrid;
current-gate voltage measurements are used to elucidate the electronic
properties. As an example application, we functionalize graphene FETs with
fluorescent proteins to yield hybrids that respond to light at wavelengths
defined by the optical absorption spectrum of the proteinComment: 10 pages, 3 figures; To appear in Applied Physics Letter
Multivalent Adhesion Molecule 7 Clusters Act as Signaling Platform for Host Cellular GTPase Activation and Facilitate Epithelial Barrier Dysfunction
Vibrio parahaemolyticus is an emerging bacterial pathogen which colonizes the gastrointestinal tract and can cause severe enteritis and bacteraemia. During infection, V. parahaemolyticus primarily attaches to the small intestine, where it causes extensive tissue damage and compromises epithelial barrier integrity. We have previously described that Multivalent Adhesion Molecule (MAM) 7 contributes to initial attachment of V. parahaemolyticus to epithelial cells. Here we show that the bacterial adhesin, through multivalent interactions between surface-induced adhesin clusters and phosphatidic acid lipids in the host cell membrane, induces activation of the small GTPase RhoA and actin rearrangements in host cells. In infection studies with V. parahaemolyticus we further demonstrate that adhesin-triggered activation of the ROCK/LIMK signaling axis is sufficient to redistribute tight junction proteins, leading to a loss of epithelial barrier function. Taken together, these findings show an unprecedented mechanism by which an adhesin acts as assembly platform for a host cellular signaling pathway, which ultimately facilitates breaching of the epithelial barrier by a bacterial pathogen. © 2014 Lim et al
āYes, and ā¦ā Exploring the Future of Learning Analytics in Medical Education
This Conversations Starter article presents a selected research abstract from the 2017 Association of American Medical Colleges Northeastern Region Group on Educational Affairs annual spring meeting. The abstract is paired with the integrative commentary of three experts who shared their thoughts stimulated by the study. Commentators brainstormed āwhat\u27s nextā with learning analytics in medical education, including advancements in interaction metrics and the use of interactivity analysis to deepen understanding of perceptual, cognitive, and social learning and transfer processes
A comparative analysis of the effect of low-cost fish and commercially compounded feed on growth performance and organoleptic quality of hybrid grouper (Epinephelus fuscoguttatusĆ Epinephelus lanceolatus) in cage farming in Kuala Penyu, Sabah, and nutritional costs
A 25-week feeding trial was conducted to assess the growth performance, organoleptic quality, and to estimate the viability of nourishing hybrid grouper (Epinephelus fuscoguttatus x Epinephelus lanceolatus) with low-cost fish (LCF) and commercially compound feed (CCF). A group of 3600 juvenile fish (182g) were released in four sea cages and fed with either LCF or CCF in duplicate. At the end of the trial, the hybrid grouper provided LCF attained a significantly higher (P0.05). Although technicalities of fish fed with LCF suggest that LCF is more efficient than CCF, feeding LCF to high-value fish is an unsustainable practice as LCF is usually obtained through trawling āa destructive fishing method for the marine ecosystem. Therefore, feeding with CCF without the use of LCF as the source of protein for its fishmeal will contribute to sustainable aquaculture. In order to convince the local farmers in Sabah to adopt the practice of feeding CCF, future research should focus on completing the species-specific diet formulation to promote optimum growth, and find ways to reduce the CCF local selling price
A multiāethnic analysis of immuneārelated gene expression signatures in patients with ovarian clear cell carcinoma
10.1002/path.5769The Journal of Patholog
Progress in upscaling Miscanthus biomass production for the European bio-economy with seed-based hybrids
Funded by UK's Biotechnology and Biological Sciences Research Council (BBSRC) Department for Environment, Food and Rural Affairs (DEFRA). Grant Number: LK0863 BBSRC strategic programme Grant on Energy Grasses & Bio-refining. Grant Number: BBS/E/W/10963A01 OPTIMISC. Grant Number: FP7-289159 WATBIO. Grant Number: FP7-311929 Innovate UK/BBSRC āMUSTā. Grant Number: BB/N016149/1Peer reviewedPublisher PD
Deletion of the WD40 Domain of LRRK2 in Zebrafish Causes Parkinsonism-Like Loss of Neurons and Locomotive Defect
LRRK2 plays an important role in Parkinson's disease (PD), but its biological functions are largely unknown. Here, we cloned the homolog of human LRRK2, characterized its expression, and investigated its biological functions in zebrafish. The blockage of zebrafish LRRK2 (zLRRK2) protein by morpholinos caused embryonic lethality and severe developmental defects such as growth retardation and loss of neurons. In contrast, the deletion of the WD40 domain of zLRRK2 by morpholinos targeting splicing did not induce severe embryonic developmental defects; rather it caused Parkinsonism-like phenotypes, including loss of dopaminergic neurons in diencephalon and locomotion defects. These neurodegenerative and locomotion defects could be rescued by over-expressing zLRRK2 or hLRRK2 mRNA. The administration of L-dopa could also rescue the locomotion defects, but not the neurodegeneration. Taken together, our results demonstrate that zLRRK2 is an ortholog of hLRRK2 and that the deletion of WD40 domain of zLRRK2 provides a disease model for PD
Genomic insights into rapid speciation within the worldās largest tree genus Syzygium
Species radiations, despite immense phenotypic variation, can be difficult to resolve phylogenetically when genetic change poorly matches the rapidity of diversification. Genomic potential furnished by palaeopolyploidy, and relative roles for adaptation, random drift and hybridisation in the apportionment of genetic variation, remain poorly understood factors. Here, we study these aspects in a model radiation, Syzygium, the most species-rich tree genus worldwide. Genomes of 182 distinct species and 58 unidentified taxa are compared against a chromosome-level reference genome of the sea apple, Syzygium grande. We show that while Syzygium shares an ancient genome doubling event with other Myrtales, little evidence exists for recent polyploidy events. Phylogenomics confirms that Syzygium originated in Australia-New Guinea and diversified in multiple migrations, eastward to the Pacific and westward to India and Africa, in bursts of speciation visible as poorly resolved branches on phylogenies. Furthermore, some sublineages demonstrate genomic clines that recapitulate cladogenetic events, suggesting that stepwise geographic speciation, a neutral process, has been important in Syzygium diversification
Epithelial Ovarian Cancer
Epithelial ovarian cancer generally presents at an advanced stage and is the most common cause of gynaecological cancer death. Treatment requires expert multidisciplinary care. Population-based screening has been ineffective, but new approaches for early diagnosis and prevention that leverage molecular genomics are in development. Initial therapy includes surgery and adjuvant therapy. Epithelial ovarian cancer is composed of distinct histological subtypes with unique genomic characteristics, which are improving the precision and effectiveness of therapy, allowing discovery of predictors of response such as mutations in breast cancer susceptibility genes BRCA1 and BRCA2, and homologous recombination deficiency for DNA damage response pathway inhibitors or resistance (cyclin E1). Rapidly evolving techniques to measure genomic changes in tumour and blood allow for assessment of sensitivity and emergence of resistance to therapy, and might be accurate indicators of residual disease. Recurrence is usually incurable, and patient symptom control and quality of life are key considerations at this stage. Treatments for recurrence have to be designed from a patient's perspective and incorporate meaningful measures of benefit. Urgent progress is needed to develop evidence and consensus-based treatment guidelines for each subgroup, and requires close international cooperation in conducting clinical trials through academic research groups such as the Gynecologic Cancer Intergroup.status: publishe
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