93 research outputs found
Systematic review of the use of honey as a wound dressing
OBJECTIVE: To investigate topical honey in superficial burns and wounds though a systematic review of randomised controlled trials. DATA SOURCES: Cochrane Library, MEDLINE, EMBASE, PubMed, reference lists and databases were used to seek randomised controlled trials. Seven randomised trials involved superficial burns, partial thickness burns, moderate to severe burns that included full thickness injury, and infected postoperative wounds. REVIEW METHODS: Studies were randomised trials using honey, published papers, with a comparator. Main outcomes were relative benefit and number-needed-to-treat to prevent an outcome relating to wound healing time or infection rate. RESULTS: One study in infected postoperative wounds compared honey with antiseptics plus systemic antibiotics. The number needed to treat with honey for good wound healing compared with antiseptic was 2.9 (95% confidence interval 1.7 to 9.7). Five studies in patients with partial thickness or superficial burns involved less than 40% of the body surface. Comparators were polyurethane film, amniotic membrane, potato peel and silver sulphadiazine. The number needed to treat for seven days with honey to produce one patient with a healed burn was 2.6 (2.1 to 3.4) compared with any other treatment and 2.7 (2.0 to 4.1) compared with potato and amniotic membrane. For some or all outcomes honey was superior to all these treatments. Time for healing was significantly shorter for honey than all these treatments. The quality of studies was low. CONCLUSION: Confidence in a conclusion that honey is a useful treatment for superficial wounds or burns is low. There is biological plausibility
A novel mechanical cleavage method for synthesizing few-layer graphenes
A novel method to synthesize few layer graphene from bulk graphite by mechanical cleavage is presented here. The method involves the use of an ultrasharp single crystal diamond wedge to cleave a highly ordered pyrolytic graphite sample to generate the graphene layers. Cleaving is aided by the use of ultrasonic oscillations along the wedge. Characterization of the obtained layers shows that the process is able to synthesize graphene layers with an area of a few micrometers. Application of oscillation enhances the quality of the layers produced with the layers having a reduced crystallite size as determined from the Raman spectrum. Interesting edge structures are observed that needs further investigation
N-type graphene induced by dissociative H-2 adsorption at room temperature
Studies of the interaction between hydrogen and graphene have been increasingly required due to the indispensable modulation of the electronic structure of graphene for device applications and the possibility of using graphene as a hydrogen storage material. Here, we report on the behaviour of molecular hydrogen on graphene using the gate voltage-dependent resistance of single-, bi-, and multi-layer graphene sheets as a function of H-2 gas pressure up to 24 bar from 300 K to 345 K. Upon H-2 exposure, the charge neutrality point shifts toward the negative gate voltage region, indicating n-type doping, and distinct Raman signature changes, increases in the interlayer distance of multi-layer graphene, and a decrease in the d-spacing occur, as determined by TEM. These results demonstrate the occurrence of dissociative H-2 adsorption due to the existence of vacancy defects on graphene.open12
Compulsive Internet Use Among Adolescents: Bidirectional Parent–Child Relationships
Although parents experience growing concerns about their children’s excessive internet use, little is known about the role parents can play to prevent their children from developing Compulsive Internet Use (CIU). The present study addresses associations between internet-specific parenting practices and CIU among adolescents, as well as the bidirectionality of these associations. Two studies were conducted: a cross-sectional study using a representative sample of 4,483 Dutch students and a longitudinal study using a self-selected sample of 510 Dutch adolescents. Results suggest that qualitatively good communication regarding internet use is a promising tool for parents to prevent their teenage children from developing CIU. Besides, parental reactions to excessive internet use and parental rules regarding the content of internet use may help prevent CIU. Strict rules about time of internet use, however, may promote compulsive tendencies. Finally, one opposite link was found whereby CIU predicted a decrease in frequency of parental communication regarding internet use
Co-rumination buffers the link between social anxiety and depressive symptoms in early adolescence
Objectives:
We examined whether co-rumination with online friends buffered the link between social anxiety and depressive symptoms over time in a community sample.
Methods:
In a sample of 526 participants (358 girls; Mage = 14.05) followed at three time points, we conducted a latent cross-lagged model with social anxiety, depressive symptoms, and co-rumination, controlling for friendship stability and friendship quality, and adding a latent interaction between social anxiety and co-rumination predicting depressive symptoms.
Results:
Social anxiety predicted depressive symptoms, but no direct links between social anxiety and co-rumination emerged. Instead, co-rumination buffered the link between social anxiety and depressive symptoms for adolescents with higher but not lower levels of social anxiety.
Conclusions:
These findings indicate that co-rumination exerted a positive influence on interpersonal relationships by diminishing the influence from social anxiety on depressive symptoms over time
Engineering the fatty acid synthesis pathway in Synechococcus elongatus PCC 7942 improves omega-3 fatty acid production
Background: The microbial production of fatty acids has received great attention in the last few years as feedstock for the production of renewable energy. The main advantage of using cyanobacteria over other organisms is their ability to capture energy from sunlight and to transform CO2 into products of interest by photosynthesis, such as fatty acids. Fatty acid synthesis is a ubiquitous and well-characterized pathway in most bacteria. However, the activity of the enzymes involved in this pathway in cyanobacteria remains poorly explored. Results: To characterize the function of some enzymes involved in the saturated fatty acid synthesis in cyanobacteria, we genetically engineered Synechococcus elongatus PCC 7942 by overexpressing or deleting genes encoding enzymes of the fatty acid synthase system and tested the lipid profile of the mutants. These modifications were in turn used to improve alpha-linolenic acid production in this cyanobacterium. The mutant resulting from fabF overexpression and fadD deletion, combined with the overexpression of desA and desB desaturase genes from Synechococcus sp. PCC 7002, produced the highest levels of this omega-3 fatty acid. Conclusions: The fatty acid composition of S. elongatus PCC 7942 can be significantly modified by genetically engineering the expression of genes coding for the enzymes involved in the first reactions of fatty acid synthesis pathway. Variations in fatty acid composition of S. elongatus PCC 7942 mutants did not follow the pattern observed in Escherichia coli derivatives. Some of these modifications can be used to improve omega-3 fatty acid production. This work provides new insights into the saturated fatty acid synthesis pathway and new strategies that might be used to manipulate the fatty acid content of cyanobacteria.Work in the FDLC laboratory was financed by the Spanish Ministry of Economy and Competitivity (MINECO) Grant BFU2014-55534-C2-1-P. MSM. was recipientof a Ph.D. fellowship (BES-2012-057387) from MINECO
Groundnut
Groundnut, a crop rich in nutrients, originated in South America and
spread to the rest of the world. Cultivated groundnut contains a fraction of
the genetic diversity present in their closely related wild relatives, which is
not more than 13 %, due to domestication bottleneck. Closely related ones
are placed in section Arachis , which have not been extensively utilized
until now due to ploidy differences between the cultivated and wild relatives.
In order to overcome Arachis species utilization bottleneck, a large
number of tetraploid synthetics were developed at the Legume Cell
Biology Unit of Grain Legumes Program, ICRISAT, India. Evaluation of
synthetics for some of the constraints showed that these were good sources
of multiple disease and pest resistances. Some of the synthetics were utilized
by developing ABQTL mapping populations, which were screened
for some biotic and abiotic constraints. Phenotyping experiments showed
ABQTL progeny lines with traits of interest necessary for the improvement
of groundnut
A comparative Raman study of the interaction of electron donor and acceptor molecules with graphene prepared by different methods
Interaction of tetrathiafulvalene (TTF) and tetracyanoethylene (TCNE) with few-layer graphene samples prepared by the exfoliation of graphite oxide (EG), conversion of nanodiamond (DG) and arc-evaporation of graphite in hydrogen (HG) has been investigated by Raman spectroscopy to understand the role of the graphene surface. The position and full-width at half maximum of the Raman G-band are affected on interaction with TTF and TCNE and the effect is highest with EG and least with HG. The effect of TTF and TCNE on the 2D-band is also maximum with EG. The magnitude of interaction between the donor/acceptor molecules varies in the same order as the surface areas of the graphenes. (C) 2009 Published by Elsevier B. V
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