297 research outputs found
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CELF significantly reduces milling requirements and improves soaking effectiveness for maximum sugar recovery of Alamo switchgrass over dilute sulfuric acid pretreatment
BackgroundPretreatment is effective in reducing the natural recalcitrance of plant biomass so polysaccharides in cell walls can be accessed for conversion to sugars. Furthermore, lignocellulosic biomass must typically be reduced in size to increase the pretreatment effectiveness and realize high sugar yields. However, biomass size reduction is a very energy-intensive operation and contributes significantly to the overall capital cost.ResultsIn this study, the effect of particle size reduction and biomass presoaking on the deconstruction of Alamo switchgrass was examined prior to pretreatment by dilute sulfuric acid (DSA) and Co-solvent Enhanced Lignocellulosic Fractionation (CELF) at pretreatment conditions optimized for maximum sugar release by each pretreatment coupled with subsequent enzymatic hydrolysis. Sugar yields by enzymatic hydrolysis were measured over a range of enzyme loadings. In general, DSA successfully solubilized hemicellulose, while CELF removed nearly 80% of Klason lignin from switchgrass in addition to the majority of hemicellulose. Presoaking and particle size reduction did not have a significant impact on biomass compositions after pretreatment for both DSA and CELF. However, presoaking for 4 h slightly increased sugar yields by enzymatic hydrolysis of DSA-pretreated switchgrass compared to unsoaked samples, whereas sugar yields from enzymatic hydrolysis of CELF solids continued to increase substantially for up to 18 h of presoaking time. Of particular importance, DSA required particle size reduction by knife milling to < 2 mm in order to achieve adequate sugar yields by subsequent enzymatic hydrolysis. CELF solids, on the other hand, realized nearly identical sugar yields from unmilled and milled switchgrass even at very low enzyme loadings.ConclusionsCELF was capable of achieving nearly theoretical sugar yields from enzymatic hydrolysis of pretreated switchgrass solids without size reduction, unlike DSA. These results indicate that CELF may be able to eliminate particle size reduction prior to pretreatment and thereby reduce overall costs of biological processing of biomass to fuels. In addition, presoaking proved much more effective for CELF than for DSA, particularly at low enzyme loadings
Qalb ommu
Ä abra ta’ poeżiji u proża li tinkludi: Il-għanja tal-ħamsa u tletin sena ta’ Patri Mattew – Meta lbist il-Ä¡lekk ta’ ħija ta’ George Vella – Tliet poeżiji qosra ta’ John Sciberras – Għada jisbaħ xorta waħda – Ä ejjin id-dgħajjes – Il-kotra u ż-żmien – Ferħa bla temma ta’ A. Guillaumier – Qalb ommu ta’ Jos. M. Manara.N/
Hybrid Epsilon-Near-Zero Modes of Photonic Gap Antennas
We demonstrate that in photonic gap antennas composed of an epsilon-near-zero
(ENZ) layer embedded within a high-index dielectric, hybrid modes emerge from
the strong coupling between the ENZ thin film and the photonic modes of the
dielectric antenna. These hybrid modes show giant electric field enhancements,
large enhancements of the far-field spontaneous emission rate and a
unidirectional radiation response. We analyze both parent and hybrid modes
using quasinormal mode theory and find that the hybridization can be well
understood using a coupled oscillator model. Under plane wave illumination,
hybrid ENZ antennas can concentrate light with an electric field amplitude
100 times higher than that of the incident wave, which places them on par
with the best plasmonic antennas. In addition, the far-field spontaneous
emission rate of a dipole embedded at the antenna hotspot reaches up to
2300 that in free space, with nearly perfect unidirectional emission.Comment: 5 figures, 6 page
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A Multifunctional Cosolvent Pair Reveals Molecular Principles of Biomass Deconstruction
Transient Disruption of the Inferior Parietal Lobule Impairs the Ability to Attribute Intention to Action
Although it is well established that fronto-parietal regions are active during action observation, whether they play a causal role in the ability to infer others\u2019 intentions from visual kinematics remains undetermined. In the experiments reported here, we combined offline continuous theta burst stimulation (cTBS) with computational modeling to reveal and causally probe single-trial computations in the inferior parietal lobule (IPL) and inferior frontal gyrus (IFG). Participants received cTBS over the left anterior IPL and the left IFG pars orbitalis in separate sessions before completing an intention discrimination task (discriminate intention of observed reach-to-grasp acts) or a kinematic discrimination task unrelated to intention (discriminate peak wrist height of the same acts). We targeted intention-sensitive regions whose fMRI activity, recorded when observing the same reach-to-grasp acts, could accurately discriminate intention. We found that transient disruption of activity of the left IPL, but not the IFG, impaired the observer\u2019s ability to attribute intention to action. Kinematic discrimination unrelated to intention, in contrast, was largely unaffected. Computational analyses of how encoding (mapping of intention to movement kinematics) and readout (mapping of kinematics to intention choices) intersect at the single-trial level revealed that IPL cTBS did not diminish the overall sensitivity of intention readout to movement kinematics. Rather, it selectively misaligned intention readout with respect to encoding, deteriorating mapping from informative kinematic features to intention choices. These results provide causal evidence of how the left anterior IPL computes mapping from kinematics to intention
Employing Channel Probing to Derive End-of-Life Service Margins for Optical Spectrum Services
Optical Spectrum as a Service (OSaaS) spanning over multiple transparent
optical network domains, can significantly reduce the investment and
operational costs of the end-to-end service. Based on the black-link approach,
these services are empowered by reconfigurable transceivers and the emerging
disaggregation trend in optical transport networks. This work investigates the
accuracy aspects of the channel probing method used in Generalized Signal to
Noise Ratio (GSNR)-based OSaaS characterization in terrestrial brownfield
systems. OSaaS service margins to accommodate impacts from enabling neighboring
channels and end-of-life channel loads are experimentally derived in a
systematic lab study carried out in the Open Ireland testbed. The applicability
of the lab-derived margins is then verified in the HEAnet production network
using a 400 GHz wide OSaaS. Finally, the probing accuracy is tested by
depleting the GSNR margin through power adjustments utilizing the same 400 GHz
OSaaS in the HEAnet live network. A minimum of 0.92 dB and 1.46 dB of service
margin allocation is recommended to accommodate the impacts of enabling
neighboring channels and end-of-life channel loads. Further 0.6 dB of GSNR
margin should be allocated to compensate for probing inaccuracies
Early socialization and environmental enrichment of lactating piglets affects the caecal microbiota and metabolomic response after weaning
The aim of this study was to determine the possible impact of early socialization and an enriched neonatal environment to improve adaptation of piglets to weaning. We hypothesized that changes in the microbiota colonization process and in their metabolic response and intestinal functionality could help the animals face weaning stress. A total of 48 sows and their litters were allotted into a control (CTR) or an enriched treatment (ENR), in which piglets from two adjacent pens were combined and enriched with toys. The pattern of caecal microbial colonization, the jejunal gene expression, the serum metabolome and the intestinal physiology of the piglets were assessed before (-2 d) and after weaning (+ 3d). A differential ordination of caecal microbiota was observed after weaning. Serum metabolome suggested a reduced energetic metabolism in ENR animals, as evidenced by shifts in triglycerides and fatty acids, VLDL/LDL and creatine regions. The TLR2 gene showed to be downregulated in the jejunum of ENR pigs after weaning. The integration of gene expression, metabolome and microbiota datasets confirmed that differences between barren and enriched neonatal environments were evident only after weaning. Our results suggest that improvements in adaptation to weaning could be mediated by a better response to the post-weaning stress
Identification of fetal DNA and cells in skin lesions from women with systemic sclerosis
BACKGROUND: Systemic sclerosis is a disease of unknown origin which often occurs in women after their childbearing years. It has many clinical and histopathological similarities to chronic graft-versus-host disease. Recent studies indicate that fetal stem cells can survive in the maternal circulation for many years post partum. This finding suggests that fetal cells persisting in the maternal circulation or tissues could be involved in the pathogenesis of systemic sclerosis by initiating a graft-versus-host reaction.
METHODS: We used the polymerase chain reaction (PCR) to identify Y-chromosome sequences in DNA extracted from peripheral-blood cells and skin lesions from women with systemic sclerosis of recent onset. To confirm the PCR findings, we used fluorescence in situ hybridization of peripheral-blood cells and cells within chronic inflammatory-cell infiltrates in biopsy specimens of affected skin.
RESULTS: Y-chromosome sequences were found in DNA from peripheral-blood cells in 32 of 69 women with systemic sclerosis (46 percent), as compared with 1 of 25 normal women (4 percent, P\u3c0.001), and in T lymphocytes from 3 women with systemic sclerosis who had male offspring. Furthermore, Y-chromosome sequences were identified in skin-biopsy specimens from 11 of 19 women with systemic sclerosis (58 percent); 9 of the 11 were known to have carried male fetuses. Nucleated cells containing Y chromosomes were detected by fluorescence in situ hybridization in paraffin-embedded sections of skin lesions from all seven women we tested whose skin-biopsy specimens contained Y-chromosome sequences.
CONCLUSIONS: Fetal antimaternal graft-versus-host reactions may be involved in the pathogenesis of systemic sclerosis in some women
Biotargeted nanomedicines for cancer: six tenets before you begin
Biotargeted nanomedicines have captured the attention of academic and industrial scientists who have been motivated by the theoretical possibilities of the ‘magic bullet’ that was first conceptualized by Paul Ehrlich at the beginning of the 20th century. The Biotargeting Working Group, consisting of more than 50 pharmaceutical scientists, engineers, biologists and clinicians, has been formed as part of the National Cancer Institute’s Alliance for Nanotechnology in Cancer to harness collective wisdom in order to tackle conceptual and practical challenges in developing biotargeted nanomedicines for cancer. In modern science and medicine, it is impossible for any individual to be an expert in every aspect of biology, chemistry, materials science, pharmaceutics, toxicology, chemical engineering, imaging, physiology, oncology and regulatory affairs. Drawing on the expertise of leaders from each of these disciplines, this commentary highlights six tenets of biotargeted cancer nanomedicines in order to enable the translation of basic science into clinical practice
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