Surface plasmon enhancement of broadband photoluminescence emission from graphene oxide

The photoluminescence (PL) emission studies of both graphene oxide (GO) and partially reduced graphene oxide (rGO) have been investigated. It has been observed that GO has broadband emission from the green to near infrared range and upon reduction rGO shows blue PL emission. The broadband PL emission is due to the recombination of the electron-hole pair in the sp(2) domain embedded within the sp(3) matrix. The broadband PL emission also suggests the existence of various sizes of the sp(2) domain within the same matrix. Furthermore, PL emission from GO in the presence of an Au metal thin film has been investigated. It has been observed that the entire broadband emission from GO in the green to near infrared wavelength region is enhanced significantly at room temperature. The Au-GO interface exhibits surface plasmon resonance in the visible wavelength region and is responsible for over 10 fold enhancement in the photoluminescence at ∼2.36 eV. The electrical property measurements on the GO and rGO thin films suggested that the rGO exhibits significantly higher electrical conductivity compared to that of the GO thin film. Furthermore, the GO thin film exhibits semiconducting behaviour. These properties make the material quite suitable for fabrication of new generation photonic devices.

A new cytotype of the African pygmy mouse Mus minutoides in Eastern Africa. Implications for the evolution of sex-autosome translocations

The African pygmy mice (genus Mus, subgenus Nannomys) are recognized for their highly conserved morphology but extensive chromosomal diversity, particularly involving sex-autosome translocations, one of the rarest chromosomal rearrangements among mammals. It has been shown that in the absence of unambiguous diagnostic morphological traits, sex-autosome translocations offer accurate taxonomic markers. For example, in Mus minutoides, irrespective of the diploid number (which ranges from 2n = 18 to 34), all specimens possess the sex-autosome translocations (X.1) and (Y.1) that are unique to this species. In this study, we describe a new cytotype that challenges this view. Males are characterized by the translocation (Y.1) only, while females carry no sex-autosome translocation, the X chromosome being acrocentric. Hence, although sex-autosome translocations (X.1) and (Y.1) are still diagnostic when one or both are present, their absence does not rule out M. minutoides. This cytotype has a large distribution, with specimens found in Tanzania and in the eastern part of South Africa. The nonpervasive distribution of Rb(X.1) provides an opportunity to investigate different evolutionary scenarios of sex-autosome translocations using a phylogenetic framework and the distribution of telomeric repeats. The results tend to support a scenario involving a reversal event, i.e., fusion then fission of Rb(X.1), and highlighted the existence of a new X1X1X2X2/X1X2Y sex chromosome system, confirming the remarkable diversity of neo-sex chromosomes and sex determination systems in the African pygmy mice.

A 3'-UTR KRAS-variant is associated with cisplatin resistance in patients with recurrent and/or metastatic head and neck squamous cell carcinoma

BACKGROUND

A germline mutation in the 3'-untranslated region of KRAS (rs61764370, KRAS-variant: TG/GG) has previously been associated with altered patient outcome and drug resistance/sensitivity in various cancers. We examined the prognostic and predictive significance of this variant in recurrent/metastatic (R/M) head and neck squamous cell carcinoma (HNSCC).

PATIENTS AND METHODS

We conducted a retrospective study of 103 HNSCCs collected from three completed clinical trials. KRAS-variant genotyping was conducted for these samples and 8 HNSCC cell lines. p16 expression was determined in a subset of 26 oropharynx tumors by immunohistochemistry. Microarray analysis was also utilized to elucidate differentially expressed genes between KRAS-variant and non-variant tumors. Drug sensitivity in cell lines was evaluated to confirm clinical findings.

RESULTS

KRAS-variant status was determined in 95/103 (92%) of the HNSCC tumor samples and the allelic frequency of TG/GG was 32% (30/95). Three of the HNSCC cell lines (3/8) studied had the KRAS-variant. No association between KRAS-variant status and p16 expression was observed in the oropharynx subset (Fisher's exact test, P = 1.0). With respect to patient outcome, patients with the KRAS-variant had poor progression-free survival when treated with cisplatin (log-rank P = 0.002). Conversely, KRAS-variant patients appeared to experience some improvement in disease control when cetuximab was added to their platinum-based regimen (log-rank P = 0.04).

CONCLUSIONS

The TG/GG rs61764370 KRAS-variant is a potential predictive biomarker for poor platinum response in R/M HNSCC patients.

CLINICAL TRIAL REGISTRATION NUMBERS

NCT00503997, NCT00425750, NCT00003809.

Evaluation of two fibrous wound dressings for the management of leg ulcers: results of a European randomised controlled trial (EARTH RCT)

OBJECTIVE

To evaluate the performance (efficacy, safety and acceptability) of a new micro-adherent absorbent dressing (UrgoClean®) compared with a hydrofiber dressing (Aquacel®) in the local management of venous leg ulcers, in the debridement stage.

METHOD

A non-inferiority European randomised controlled clinical trial (RCT) was conducted in 37 centres, on patients presenting with venous or predominantly venous, mixed aetiology leg ulcers at their sloughy stage (with more than 70% of the wound bed covered with slough at baseline). Patients were followed over a 6-week period and assessed weekly. The primary judgement criteria was the relative regression of the wound surface area after the 6-week treatment period. Secondary endpoints were the relative reduction of sloughy tissue and the percentage of patients presenting with a debrided wound.

RESULTS

Altogether, 159 patients were randomised to either UrgoClean (test group; n=83) or Aquacel (control group; n=76) dressings. Regarding the wound healing process predictive factors (wound area, duration, ABPI value, recurrence), at baseline, the two groups were well balanced, for both wound and patient characteristics. Compression therapy was administered to both groups and after a median 42-day treatment period, the percentage of relative reduction of the wound surface area was very similar (-36.9% vs -35.4% in the UrgoClean and control groups, respectively). When considering the secondary criteria at week 6, the relative reduction of sloughy tissue was significantly higher in the UrgoClean group than in the control group (-65.3% vs -42,6%; p=0.013). The percentage of debrided wounds was also significantly higher in the test group (52.5% vs 35.1%; p=0.033).

CONCLUSION

This 'EARTH' RCT confirmed that the UrgoClean dressing has similar efficacy and safety compared to Aquacel. However, UrgoClean also showed better autolytic properties than the control group in the management of venous leg ulcers at the sloughy stage. The new UrgoClean dressing therefore represents a promising therapeutic option within the current range of autolytic dressings available.

DECLARATION OF INTEREST

This study was sponsored by a grant from the pharmaceutical company Laboratoires Urgo. S. Bohbot and O. Tacca are employees of Laboratoires Urgo. S. Meaume, J. Dissemond and G. Perceau have received monetary compensation as presenters for Laboratoires Urgo. Data management and statistical analyses were conducted independently by Vertical (Paris, France).

Vibration frequency measurement using a local multithreshold technique

In this paper, we demonstrate the use of a video camera for measuring the frequency of small-amplitude vibration movements. The method is based on image acquisition and multilevel thresholding and it only requires a video camera with high enough acquisition rate, not being necessary the use of targets or auxiliary laser beams. Our proposal is accurate and robust. We demonstrate the technique with a pocket camera recording low-resolution videos with AVI-JPEG compression and measuring different objects that vibrate in parallel or perpendicular direction to the optical sensor. Despite the low resolution and the noise, we are able to measure the main vibration modes of a tuning fork, a loudspeaker and a bridge. Results are successfully compared with design parameters and measurements with alternative devices.

Interaction between cholecystokinin and the fibroblast growth factor system in the ventral tegmental area of selectively bred high- and low-responder rats

Individual differences in the locomotor response to novelty have been linked to basal differences in dopaminergic neurotransmission. Mesolimbic dopaminergic outputs are regulated by cholecystokinin (CCK), a neuropeptide implicated in anxiety. In turn, CCK expression is regulated by fibroblast growth factor-2 (FGF2), which has recently been identified as an endogenous regulator of anxiety. FGF2 binds to the high-affinity fibroblast growth factor receptor-1 (FGF-R1) to regulate the development and maintenance of dopamine neurons in the ventral tegmental area (VTA). However, the relationship between the FGF and CCK systems in the VTA is not well understood. Therefore, we utilized the selectively-bred low-responder (bLR; high-anxiety) and high-responder (bHR; low-anxiety) rats to examine the effects of repeated (21-day) FGF2 treatment on CCK and FGF-R1 mRNA in the rostral VTA (VTAr). In vehicle-treated controls, both CCK and FGF-R1 mRNA levels were increased in the VTAr of bLR rats relative to bHR rats. Following FGF2 treatment, however, bHR-bLR differences in CCK and FGF-R1 mRNA expression were eliminated, due to decreased CCK mRNA levels in the VTAr of bLR rats and increased FGF-R1 expression in bHR rats. Differences after FGF2 treatment may denote distinct interactions between the CCK and FGF systems in the VTAr of bHR vs. bLR rats. Indeed, significant correlations between CCK and FGF-R1 mRNA expression were found in bHR, but not bLR rats. Colocalization studies suggest that CCK and FGF-R1 are coexpressed in some VTAr neurons. Taken together, our findings suggest that the FGF system is poised to modulate both CCK and FGF-R1 expression in the VTAr, which may be associated with individual differences in mesolimbic pathways associated with anxiety-like behavior.

Interspecific introgression and changes in population structure in a flatfish species complex after the Prestige accident

Oil spills cause aggressive impacts on marine ecosystems affecting immense areas and the species inhabiting them. If wastes are not cleaned up properly, the remnants may affect local populations for a long time. This work focuses on the long-term impacts of the Prestige spillage that occurred off Galician coast (Spain) in November 2002. Model species were two sympatric flatfish, the megrims Lepidorhombus whiffiagonis and Lepidorhombus boscii. Samples obtained before and nine years after the Prestige accident from affected and unaffected areas were genotyped for six hypervariable nuclear markers and for the mitochondrial D-loop sequence. The results revealed a high proportion of post-F1 interspecific hybrids in the area affected, and also increased intraspecific population differentiation likely due to such localized introgression of foreign genes. These changes suggest the appearance of a hybrid zone following the accident and emphasize the need of paying special attention to potential evolutionary impacts of oil spills.