Permanent water swelling effect in low temperature thermally reduced graphene oxide

We demonstrate permanent water trapping in reduced graphene oxide after high relative humidity exposure. For this purpose, we grew graphene oxide films via spin-coating on glass substrates followed by thermal reduction. The electrical resistance of the planar device was then measured. We observed that resistance is significantly increased after water vapor exposure and remains stable even after 250 days in ambient conditions. Various techniques were applied to desorb the water and decrease (recover) the material's resistance, but it was achieved only with low temperature thermal annealing (180 °C) under forming gas (H2/N2 mixture). The permanent effect of water absorption was also detected by x-ray photoelectron spectroscopy.</p

Giant persistent photoconductivity in monolayer MoS2 field-effect transistors

Monolayer transition metal dichalcogenides (TMD) have numerous potential applications in ultrathin electronics and photonics. The exposure of TMD-based devices to light generates photo-carriers resulting in an enhanced conductivity, which can be effectively used, e.g., in photodetectors. If the photo-enhanced conductivity persists after removal of the irradiation, the effect is known as persistent photoconductivity (PPC). Here we show that ultraviolet light (λ = 365 nm) exposure induces an extremely long-living giant PPC (GPPC) in monolayer MoS2 (ML-MoS2) field-effect transistors (FET) with a time constant of ~30 days. Furthermore, this effect leads to a large enhancement of the conductivity up to a factor of 107. In contrast to previous studies in which the origin of the PPC was attributed to extrinsic reasons such as trapped charges in the substrate or adsorbates, we show that the GPPC arises mainly from the intrinsic properties of ML-MoS2 such as lattice defects that induce a large number of localized states in the forbidden gap. This finding is supported by a detailed experimental and theoretical study of the electric transport in TMD based FETs as well as by characterization of ML-MoS2 with scanning tunneling spectroscopy, high-resolution transmission electron microscopy, and photoluminescence measurements. The obtained results provide a basis for the defect-based engineering of the electronic and optical properties of TMDs for device applications

Genetic diversity and population structure analysis of isolates of the rice false smut pathogen Ustilaginoidea virens in India.

Not AvailableGenetic diversity assessment and population structure analysis are essential for char acterization of pathogens and their isolates. Markers are essential tools for explor ing genetic variation among the isolates. False smut of rice caused by Ustilaginoidea virens, formerly Villosiclava virens, is a major emerging disease of rice in India. A high level of variability is observed at the field level, but no information is available from India on genetic diversity and population structure. This is the first report of genetic diversity and population structure of U. virens from India that included 63 isolates dis tributed across the vast geographical area of eastern and north-eastern India (18.9 to 26.7°N and 82.6 to 94.2°E). Seventeen RAPDs and 14 SSRs were identified as poly morphic and a total of 140 alleles were detected across the populations. The average number of alleles per locus for each primer was 4.5. All the isolates were grouped into two major clusters, with partial geographical segregation that was supported by principal coordinate analysis. Mantel test suggested genetic distance within the iso lates increased with increasing geographical distance. Analysis of molecular variation showed more genetic variation within populations and less among populations. This outcome will help in understanding genetic diversity of U. virens from eastern and north-eastern India and in planning effective management strategies

New insights into the genetic etiology of Alzheimer's disease and related dementias

Characterization of the genetic landscape of Alzheimer's disease (AD) and related dementias (ADD) provides a unique opportunity for a better understanding of the associated pathophysiological processes. We performed a two-stage genome-wide association study totaling 111,326 clinically diagnosed/'proxy' AD cases and 677,663 controls. We found 75 risk loci, of which 42 were new at the time of analysis. Pathway enrichment analyses confirmed the involvement of amyloid/tau pathways and highlighted microglia implication. Gene prioritization in the new loci identified 31 genes that were suggestive of new genetically associated processes, including the tumor necrosis factor alpha pathway through the linear ubiquitin chain assembly complex. We also built a new genetic risk score associated with the risk of future AD/dementia or progression from mild cognitive impairment to AD/dementia. The improvement in prediction led to a 1.6- to 1.9-fold increase in AD risk from the lowest to the highest decile, in addition to effects of age and the APOE ε4 allele

Patterning and electrical interfacing of individually controllable conducting polymer microactuators

Conducting polymer actuators such as polypyrrole (PPy) microactuators are interesting candidates to drive autonomous microrobotic devices that require low weight and low power. Simple PPy tri-layer bending type microactuators that operate in air have been demonstrated previously but they lack individual control and had problems with short circuiting due to electrical connections. The lack of micropatterning methods and proper interfacing are currently major obstacles in the development of PPy tri-layer microactuators. Here, we report for the first time methods for successfully patterning and interfacing of such tri-layer PPy microactuators. The PPy tri-layer actuators were patterned using adapted microfabrication technology including photolithography. The interface was based on a flexible printed circuit board comprising the electronic circuit into which the actuator unit was embedded. It showed that the microfabricated tri-layer actuators functioned as good as the normally fabricated actuators. The new interface seemed to actually improve the actuator performance. This interfacing method could also be applied to other electroactive polymer devices, such as ion polymer metal composites (IPMC) and dielectric elastomers (DE)

An audit of decompressive craniectomies

Background: The management of acute intracranial hypertension refractory, to the medical management, remains a challenging endeavour. Mortality and morbidity rates remain high despite optimal medical management. Decompressive craniectomy has been proposed as an effective treatment for patients who have raised intracranial pressure (ICP) refractory, to the medical management. This study examined the outcome of patients who underwent this procedure. Aim: To assess the outcome of patients who underwent decompressive craniectomy. Materials and Methods: We conducted a prospective audit of consecutive patients of one neurosurgical unit, who underwent decompressive craniectomy at a tertiary care centre between 01/01/2004 to 31/03/2005. A complete neurological assessment, including Glasgow coma scale (GCS) and pupils was done and recorded at the time of admission, deterioration, post-op one wk and post-op three wks. End points were Glasgow outcome score (GOS) and Karnofsky score at 30 days, at discharge and at 6 months. Results: We studied 12 patients who were aged 30 to 69 yrs (Mean = 47 yrs). Unlike most interventions in critical care, survival is not an acceptable single end point. Good recovery ( Karnofsky score ≥80 / GOS≥4) was seen in five patients. Three patients were alive with severe disability ( Karnofsky score 1-70 / GOS 2-3), at follow up. Four patients died (Karnofsky score 0 / GOS 1). Conclusion: Eight patients who underwent decompressive craniectomy survived. Five of these patients had a good recovery. The other three survived with severe disability

Evaluation of the door-to-needle time for fibrinolytic administration for acute myocardial infarction

Background: Fibrinolytic therapy has reduced mortality following acute myocardial infarction (AMI) with the major effect coming from early achievement of infarct-related artery patency. Aim: To evaluate the door-to-needle time for fibrinolytic administration for AMI and to identify factors associated with a prolonged door-to-needle time. Materials and Methods: Our study was a prospective audit of patients who were thrombolyzed for AMI at our hospital from July 1, 2004 to March 15, 2005. All patients admitted with AMI, who were candidates for fibrinolysis, were included. We recorded the door-to-needle time. Whenever possible, we tried to find out the reason for prolonged door-to-needle time. Results: A door-to-needle time of < 30 min could be achieved in 19 of our 35 patients (54.28%). Mean door-to-needle time was 45.25 min. Discussion: Although most guidelines recommend a door-to-needle time of less than 30 min, most hospitals fail to achieve this in most patients. A study conducted by Zed et al. at the Vancouver General Hospital showed that a door-to-needle time of less than 30 min was achieved in only 24.3%. The door-to-needle time achieved at our center was shorter. In most of our patients who were thrombolyzed late, a delay in taking or interpreting an electrocardiogram was responsible. Transfer to the intensive care unit for thrombolysis also resulted in considerable delay. Conclusions: A door-to-needle time of less than 30 mins could be achieved in 19 of our 35 patients (54.28%). A significant number of AMI patients thrombolyzed did not meet the guideline for door-to-needle time of less than 30 min

The importance of sex stratification in autoimmune disease biomarker research: A systematic review

10.3389/fimmu.2018.01208Frontiers in Immunology9JUN120