Sustainable Production of Stiff and Crystalline Bacterial Cellulose from Orange Peel Extract

In this work, a potentially economic and environmentally friendly method for the synthesis of bacterial cellulose (BC) by Gluconacetobacter xylinus from a biomass containing orange peel extract was evaluated. Orange peel extract was used as a culture medium without any hydrolysis treatment, thus speeding up the synthesis procedure. The efficacy of orange peel as a carbon source was compared with that of sucrose. The orange peel extract formed thicker cellulose gels than those formed using sucrose. X-ray diffraction (XRD) revealed both a high crystallinity index and crystallite size of BC nanofibers in samples obtained from orange peel (BC_Orange). Field emission scanning electron microscopy (FE-SEM) revealed a highly densely packed nanofibrous structure (50 nm in diameter). BC_Orange presented a two-fold increase in water holding capacity (WHC), and dynamic mechanical analysis (DMA) showed a 44% increase in storage modulus compared to sucrose derived BC. These results showed that the naturally available carbon sources derived from orange peel extract can be effectively used for BC production. The orange-based culture medium can be considered a profitable alternative to the generation of high-value products in a virtuous circular economy model

S100B is not a reliable prognostic index in paediatric TBI.

Pediatr Neurosurg. 2007;43(4):258-64

Determination of zeolite-group mineral compositions by electron probe microanalysis

A new protocol for the quantitative determination of zeolite-group mineral compositions by electron probe microanalysis (wavelength-dispersive spectrometry) under ambient conditions, is presented. The method overcomes the most serious challenges for this mineral group, including new confidence in the fundamentally important Si-Al ratio. Development tests were undertaken on a set of natural zeolite candidate reference samples, representing the compositional extremes of Na, K, Cs, Mg, Ca, Sr and Ba zeolites, to demonstrate and assess the extent of beam interaction effects on each oxide component for each mineral. These tests highlight the variability and impact of component mobility due to beam interaction, and show that it can be minimized with recommended operating conditions of 15 kV, 2 nA, a defocused, 20 μm spot size, and element prioritizing with the spectrometer configuration. The protocol represents a pragmatic solution that works, but provides scope for additional optimization where required. Vital to the determination of high-quality results is the attention to careful preparations and the employment of strict criteria for data reduction and quality control, including the monitoring and removal of non-zeolitic contaminants from the data (mainly Fe and clay phases). Essential quality criteria include the zeolite-specific parameters of R value (Si/(Si + Al + Fe3+), the ‘E%’ charge-balance calculation, and the weight percent of non-hydrous total oxides. When these criteria are applied in conjunction with the recommended analytical operating conditions, excellent inter-batch reproducibility is demonstrated. Application of the method to zeolites with complex solid-solution compositions is effective, enabling more precise geochemical discrimination for occurrence-composition studies. Phase validation for the reference set was conducted satisfactorily with the use of X-ray diffraction and laser-ablation inductively-coupled plasma mass spectroscopy

Fast and simple spectral FLIM for biochemical and medical imaging.

Spectrally resolved fluorescence lifetime imaging microscopy (λFLIM) has powerful potential for biochemical and medical imaging applications. However, long acquisition times, low spectral resolution and complexity of λFLIM often narrow its use to specialized laboratories. Therefore, we demonstrate here a simple spectral FLIM based on a solid-state detector array providing in-pixel histrogramming and delivering faster acquisition, larger dynamic range, and higher spectral elements than state-of-the-art λFLIM. We successfully apply this novel microscopy system to biochemical and medical imaging demonstrating that solid-state detectors are a key strategic technology to enable complex assays in biomedical laboratories and the clinic.A.E. thanks the EPSRC for the initial funding of the project (EP/F044011/1) from 2009 to 2011. M.P. and L.D.C. were supported by a Programme Grant to A.R.V. from the UK Medical Research Council (MRC). This project was also supported by the MRC’s grant-in-aid to the Cancer Unit, Cambridge (A.E., A.R.V.). C.F.K acknowledges funding from the MRC (grant MR/K015850/1), the Wellcome Trust (grant 089703/Z/09/Z) and the EPSRC (EP/L015889/1).This is the author accepted manuscript. The final version is available from the Optical Society of America via http://dx.doi.org/10.1364/OE.23.02351

Torus equivariant K-stability

It is conjectured that to test the K-polystability of a polarised variety it is enough to consider test-configurations which are equivariant with respect to a torus in the automorphism group. We prove partial results towards this conjecture. We also show that it would give a new proof of the K-polystability of constant scalar curvature polarised manifolds

Forward and backward digit span difficulties in children with specific learning disorder

This study examined performance in the forward and backward digit span task of the Wechsler Intelligence Scale for Children–Fourth Edition (WISC–IV) in a large group of children with specific learning disorder (SLD) as compared with a group of typically developing children matched for age and sex. Our results further support the hypothesis that the intellectual difficulties of children with SLD involve working memory in the forward digit span task to a greater extent than in the backward digit span task. The correlation of the two spans with a General Ability Index (GAI) was similar in SLD, and smaller in magnitude than in typically developing children. Despite a GAI within normal range, children with SLD had difficulty with both digit span tasks, but more so for forward span. This pattern was similar for different SLD profiles with clinical diagnoses of dyslexia and mixed disorder, but the impairments were more severe in the latter. Age differences were also investigated, demonstrating larger span impairment in older children with SLD than in younger

Scalable Synthesis of Few-Layered 2D Tungsten Diselenide (2H-WSe2) Nanosheets Directly Grown on Tungsten (W) Foil Using Ambient-Pressure Chemical Vapor Deposition for Reversible Li-Ion Storage

We report a facile two-furnace APCVD synthesis of 2H-WSe2. A systematic study of the process parameters is performed to show the formation of the phase-pure material. Extensive characterization of the bulk and exfoliated material confirm that 2H-WSe2 is layered (i.e., 2D). X-ray diffraction (XRD) confirms the phase, while high-resolution scanning electron microscopy (HRSEM), high-resolution transmission electron microscopy (HRTEM), and atomic force microscopy (AFM) clarify the morphology of the material. Focused ion beam scanning electron microscopy (FIB-SEM) estimates the depth of the 2H-WSe2 formed on W foil to be around 5-8 μm, and Raman/UV-vis measurements prove the quality of the exfoliated 2H-WSe2. Studies on the redox processes of lithium-ion batteries (LiBs) show an increase in capacity up to 500 cycles. On prolonged cycling, the discharge capacity up to the 50th cycle at 250 mA/g of the material shows a stable value of 550 mAh/g. These observations indicate that exfoliated 2H-WSe2 has promising applications as an LiB electrode material

Evaluation of the effect of hypothermia by cold water immersion on blood neutrophils and lymphocytes of rats submitted to acute exercise

O estresse sistêmico induzido pelo exercício libera substâncias bioativas determinantes da mobilização neutrofílica. A crioterapia diminui a reação inflamatória e atenua a elevação da perfusão sanguínea induzida pelo exercício. O objetivo deste trabalho foi analisar a influência da hipotermia decorrente da crioimersão corporal (CIC) imediata ao esforço físico agudo nas concentrações neutrofílicas e linfocíticas no sangue. Os ratos do grupo controle (AI) foram mantidos em repouso enquanto os do grupo AII foram submetidos ao protocolo de CIC a 10ºC por 10 minutos. Enquanto os animais dos grupos BI, BII, BIII e BIV realizaram o esforço físico agudo (EFA) em água a 31ºC durante 100 minutos com sobrecarga corpórea de 5% do peso corporal, os dos grupos CI, CII, CIII e CIV foram submetidos ao EFA seguido imediatamente de CIC. Nos grupos B e C, os animais foram sacrificados nos períodos de 06 (I), 12 (II), 24 (III) e 48 (IV) horas posteriores ao EFA. Através da microscopia óptica realizou-se a contagem dos neutrófilos e linfócitos. Utilizou-se do Teste T Student para análise estatística considerando-se nível de significância p < 0,05. Observou-se uma significativa neutrofilia nos grupos AII, BI, BII, BIII, BIV, CI, CII e CIII em relação a AI, diferentemente do grupo CIV, que apresentou quantidade de neutrófilos igual ao grupo controle. Os valores de linfócitos nos grupos BII, BIII, BIV, CI e CII foram significativamente menores do que AI, e nos grupos AII, BI, CIII e CIV foram iguais a AI. A neutrofilia e a linfopenia posteriores ao intenso exercício agudo são mantidas por 48 horas ou mais, porém, mediante a aplicação da crioimersão corporal imediata ao exercício, são normalizadas em 24 horas.Systemic stress induced by exercise increases bioactive substances in plasma which leads to neutrophilic mobilization. Cryotherapy causes a decrease in the inflammatory reaction and attenuates high blood perfusion after exercise. The objective of this work was to analyze the influence of cold water immersion (CWI) after acute exercise on neutrophil and lymphocyte mobilization. A control group of rats (AI) was kept at rest and a second group (AII) was submitted to CWI at 10º C for 10 minutes. The animals of Groups BI, BII, BIII and BIV were submitted to acute exercise which consisted in swimming in water at 31º C for 100 minutes with a load equivalent to 5% of the body weight. Groups CI, CII, CIII and CIV were submitted to CWI immediately after acute exercise. The animals were sacrificed at 6 (I), 12 (II), 24 (III) and 48 (IV) hours after the exercise and neutrophil and lymphocyte cells were counted for all groups by optic microscopy. The Student t-test was used for statistical analysis with a significance level of p< 0.05. A significant increase in the number of neutrophils was observed in Groups AII, BI, BII, BIII, BIV, CI, CII and CIII compared to AI. The neutrophil count of the CIV Group was similar to the Control Group. There was a significant drop in the number of lymphocytes in Groups BII, BIII, BIV, CI and CII when compared to Group AI. The lymphocyte count of Groups AII, BI, CIII and CIV were similar to the Control Group. The changes in neutrophil and lymphocyte counts caused by acute exercise were reverted to normal at 24 hours by cold water immersion