Transcriptome profiling of Issatchenkia orientalis under ethanol stress

Abstract Issatchenkia orientalis, a non-Saccharomyces yeast that can resist a wide variety of environmental stresses, has potential use in winemaking and bioethanol production. Little is known about gene expression or the physiology of I. orientalis under ethanol stress. In this study, high-throughput RNA sequencing was used to investigate the transcriptome profile of I. orientalis in response to ethanol. 502 gene transcripts were differentially expressed, of which 451 were more abundant, and 51 less abundant, in cells subjected to 4 h of ethanol stress (10% v/v). Annotation and statistical analyses suggest that multiple genes involved in ergosterol biosynthesis, trehalose metabolism, and stress response are differentially expressed under these conditions. The up-regulation of molecular chaperones HSP90 and HSP70, and also genes associated with the ubiquitin–proteasome proteolytic pathway suggests that ethanol stress may cause aggregation of misfolded proteins. Finally, ethanol stress in I. orientalis appears to have a nitrogen starvation effect, and many genes involved in nutrient uptake were up-regulated

Bacterial Communities in Riparian Sediments: A Large-Scale Longitudinal Distribution Pattern and Response to Dam Construction

Sediment microbes play major roles in riparian ecosystems; however, little is known about their longitudinal distribution pattern and their responses to dam construction, the most severe human disturbance in river basins. Here, we investigated the variability of sediment bacterial communities along a large-scale longitudinal gradient and between dam-controlled and dam-affected sites in riparian zone of the Lancang River, China. The abundance, activity and diversity of sediment bacteria gradually increased in a downstream direction, but were significantly lower in the dam-affected sites than in the dam-controlled sites. The bacterial community compositions differed significantly between the upper-middle-reach and downstream sites at all control sites, and also between the dam-affected and dam-controlled sites. In the cascade dam area, the relative importance of spatial distance and environmental heterogeneity for bacterial distribution differed between the dam-controlled and dam-affected sites. Spatial distance was the primary cause of variations in bacterial community in dam-controlled site. By contrast, the environmental heterogeneity had more control over the bacterial communities than did the spatial distance in dam-affected site. Network analysis showed that the bacterial community in the dam-affected sites had lower connectivity and stability when compared with that in dam-controlled sites. These results suggest the distinct variations in sediment bacterial community in dam-affected sites, which could enhance our understanding of potential ecological effects caused by dam construction

Catalytic furfural hydrogenation to furfuryl alcohol over Cu/SiO2 catalysts: A comparative study of the preparation methods

Furfuryl alcohol, a vital intermediate for the production of foundry resins, fragrances, pharmaceuticals and pesticide, is produced by hydrogenation of furfural in gas phase or liquid phase. The furfuryl alcohol production in gas phase over silica supported copper catalyst is favored thanks to the environmental and technical advantages. The effect of preparation methods of silica supported copper catalysts on the structure and performance was investigated by means of ICP, N-2 physisorption, ex-situ/in-situ XRD, in-situ XPS, FT-1R, H-2-TPR, TEM, N20 titration, TG as well as furfural hydrogenation. The results indicated that the different catalyst synthesis strategies led to the diverse copper species in the calcined samples and disparate Cu-0 surface area as well as different molar ratio of Cu+/(Cu+ + Cu-0) in the fresh samples. The performance of impregnation derived sample was poorer than that of commercial CuCr-Strem catalyst. The catalysts prepared by deposition precipitation and ion exchange exhibited similar performance to the CuCr-Strem. The ammonia evaporation derived catalyst (Cu/SiO2-EA) showed superior performance in the activity, selectivity and stability among all the studied catalysts. The excellent performance was related to the highest surface area of Cu-0, smallest copper particle size, large surface area and pore volume as well as appropriate higher Cu+/(Cu+ + Cu-0) ratio. Furthermore, all the copper catalysts went through deactivation, which was caused by carbon deposition, during the reaction. Owing to the largest amount of Cu-0 sites and large S-BET, the Cu/SiO2-EA exhibited the slowest deactivation rate

Structural covariance in subcortical stroke patients measured by automated MRI-based volumetry

A network-level investigation of the volumetric changes of subcortical stroke patients is still lacking. Here, we explored the alterations of structural covariance caused by subcortical stroke with automated brain volumetry. T1-weighed brain MRI scans were obtained from 63 normal controls (NC), 46 stroke patients with infarct in left internal capsule (CI_L), 33 stroke patients with infarct in right internal capsule (CI_R). We performed automatic anatomical segmentation of the T1-weighted brain images with AccuBrain. Volumetric structural covariance analyses were first performed within the basal ganglia structures that were both identified by voxel-based morphometry with AAL atlas and AccuBrain. Subsequently, we additionally included the infratentorial regions that were particularly quantified by AccuBrain for the structural covariance analyses and investigated the alterations of anatomical connections within these subcortical regions in CI_L and CI_R compared with NC. The association between the regional brain volumetry and motor function was also evaluated in stroke groups. There were significant and extensive volumetric differences in stroke patients. These significant regions were generally symmetric for CI_L and CI_R group depending on the side of stroke, involving both regions close to lesions and remote regions. The structural covariance analyses revealed the synergy volume alteration in subcortical regions both in CI_L and CI_R group. In addition, the alterations of volumetric structural covariance were more extensive in CI_L group than CI_R group. Moreover, we found that the subcortical regions with atrophy contributed to the deficits of motor function in CI_R group but not CI_L group, indicating a lesion-side effect of brain volumetric changes after stroke. These findings indicated that the chronic subcortical stroke patients have extensive disordered anatomical connections involving the whole-brain level network, and the connections patterns depend on the lesion-side. Keywords: Brain segmentation, Brain volumetric changes, MRI imaging, Stroke, Structural covariance, Lesion-side effec

Synthesis, Characterization, and Catalytic Properties of Two Zwitterionic Hybrid SBA-15 Mesoporous Silicas

Zwitterionic hybrid SBA-15 mesoporous silica materials containing both amine and sulfonic acid groups have been synthesized through cocondensation from as-synthesized zwitterionic siloxane precursors (ZS) with tetraethoxysilane (TEOS). Characterization by XRD, TEM, and N2 adsorptiondesorption measurements show that the as-synthesized materials have ordered mesostructures. Analysis with UV, 29Si/13C cross-polarization magic angle spinning (CP-MAS) NMR, and X-ray photelectron spectroscopy (XPS) and elemental analysis demonstrates that the zwitterionic parts have been successfully introduced into the silica framework, and the organic contents of 15?% hybrid samples are over 1.0 mmol/g. The presence of a secondary organoamine group enables the hybrid material to be further alkalized to achieve the desired basic properties. The materials were used as catalysts for the aldol condensation of acetone with 4-nitrobenzaldehyde. With a good catalytic performance, the catalyst could be easily separated, recycled, and reactivated by secondary basification