222 research outputs found
Effects of different salt-enzymes on opening up of collagen fiber bundles for leather making
Content:
Traditional leather industry involves mechanical, chemical and biological processes, and a lot of leather chemicals are widely used annually. In the beamhouse, especially in liming and re-liming, enormous pollution is usually released because of the traditional use of Na2S and lime. Many researchers have devoted to clean production for leather making. In this study, salt-enzyme liming process was studied
in modern leather process to remove the inter-fibrillary matter. Three such salts as Na2SO4, NaCl, and MgCl2 were used with such enzymes as neutral protease and cellulase. The enzyme activity was evaluated by Folin Method. The opening up degree of collagen fiber bundles was observed by SEM and microscopic image of histological staining. The waste water was analyzed. The tannin absorptivity of the samples was evaluated by colorimetry. It was demonstrated that enzyme activity is not affected by salt, but it helps the action of enzymes on hides. Salt might accelerate the penetration of enzymes into the hide to promote the removal of inter-fibrillary and the opening up of collagen fiber bundles. The best fiber opening result was found by SEM at the MgCl2 content of more than 0.4 wt.% in liming. Microscopic observation by histological staining as well as waste water analysis indicated a good removing effect for the inter-fibrillary. This work may provide a cleaner leather making technology.
Take-Away:
1.Salt-enzyme liming process was studied in modern leather process to remove the inter-fibrillary matter.
2.To provide theoretical guidance for the clean production of leather
Regulation of Microglial Functions by Purinergic Mechanisms in the Healthy and Diseased CNS
Microglial cells, the resident macrophages of the central nervous system (CNS), exist in a process-bearing, ramified/surveying phenotype under resting conditions. Upon activation by cell-damaging factors, they get transformed into an amoeboid phenotype releasing various cell products including pro-inflammatory cytokines, chemokines, proteases, reactive oxygen/nitrogen species, and the excytotoxic ATP and glutamate. In addition, they engulf pathogenic bacteria or cell debris and phagocytose them. However, already resting/surveying microglia have a number of important physiological functions in the CNS; for example, they shield small disruptions of the blood–brain barrier by their processes, dynamically interact with synaptic structures, and clear surplus synapses during development. In neurodegenerative illnesses, they aggravate the original disease by a microglia-based compulsory neuroinflammatory reaction. Therefore, the blockade of this reaction improves the outcome of Alzheimer’s Disease, Parkinson’s Disease, multiple sclerosis, amyotrophic lateral sclerosis, etc. The function of microglia is regulated by a whole array of purinergic receptors classified as P2Y12, P2Y6, P2Y4, P2X4, P2X7, A2A, and A3, as targets of endogenous ATP, ADP, or adenosine. ATP is sequentially degraded by the ecto-nucleotidases and 5′-nucleotidase enzymes to the almost inactive inosine as an end product. The appropriate selective agonists/antagonists for purinergic receptors as well as the respective enzyme inhibitors may profoundly interfere with microglial functions and reconstitute the homeostasis of the CNS disturbed by neuroinflammation
Anisotropic shear stress effects in the basal plane of SrRuO
In this short note, we repeat the calculations the jumps for the specific
heat C, the elastic compliance S and the
thermal expansion due to a shear stress in
the basal plane of . Henceforth we clarify some issues regarding the
elastic theoretical framework suitable to explain the sound speed experiments
of Lupien et al. (2001,2002), and partially the strain experiments of Hicks et
al. (2014), and Steppke et al. (2016) in strontium ruthenate. We continue to
propose that the discontinuity in the elastic constant C of this
tetragonal crystal gives unambiguous experimental evidence that the
superconducting order parameter has two components with a broken
time-reversal symmetry state, and that the band couples the
anisotropic electron-phonon interaction to the in-plane shear stress
according to Walker and collaborators [4] and [3]. Some importants words about
the roll of the spin equal to one for the transversal phonons are added in the
conclusion following Levine [34].Comment: 11 pages, for section 5: added figure 2 and figure 3 replaced. One
reference and typos added. figure 4 added. arXiv admin note: text overlap
with arXiv:1812.0649
Influence of tree spacing on soil nitrogen mineralization and availability in hybrid poplar plantations
Nitrogen (N) availability and mineralization are key parameters and transformation processes that impact plant growth and forest productivity. We hypothesized that suitable plantation spacing can lead to enhanced soil N mineralization and nitrification, which in turn promote tree growth. Studies were conducted to evaluate seasonal patterns of soil inorganic N pools as well as rates of nitrification and N mineralization of three soil layers under four tree spacing treatments. Results showed tree spacing significantly affected annual net N mineralization, whereas inorganic N content in surface soils was significantly affected by tree spacing only during the growing season. The total annual cumulative net N mineralization ranged from 80.3–136.0 mg·kg−1 in the surface soils (0–20 cm), whereas the cumulative net N mineralization of 6 × 6 m and 4.5 × 8 m spacings was 65% and 24% higher than that of the 5 × 5 m, respectively. In general, tree spacing would affect N availability in soil by altering N mineralization rates, while high annual N mineralization was found in soils of low density plantations, with higher rates in square spacing than rectangular spacing. The obtained results suggest that suitable spacing could lead to enhanced N mineralization, but seasonal variation of soil N mineralization may not only be directly related to plantation productivity but also to understory vegetation productivity.Peer reviewedPlant and Soil Science
High genetic homogeneity points to a single introduction event responsible for invasion of Cotton leaf curl Multan virus and its associated betasatellite into China
Global genetic diversity and evolutionary patterns among Potato leafroll virus populations
Potato leafroll virus (PLRV) is a widespread and one of the most damaging viral pathogens causing significant quantitative and qualitative losses in potato worldwide. The current knowledge of the geographical distribution, standing genetic diversity and the evolutionary patterns existing among global PLRV populations is limited. Here, we employed several bioinformatics tools and comprehensively analyzed the diversity, genomic variability, and the dynamics of key evolutionary factors governing the global spread of this viral pathogen. To date, a total of 84 full-genomic sequences of PLRV isolates have been reported from 22 countries with most genomes documented from Kenya. Among all PLRV-encoded major proteins, RTD and P0 displayed the highest level of nucleotide variability. The highest percentage of mutations were associated with RTD (38.81%) and P1 (31.66%) in the coding sequences. We detected a total of 10 significantly supported recombination events while the most frequently detected ones were associated with PLRV genome sequences reported from Kenya. Notably, the distribution patterns of recombination breakpoints across different genomic regions of PLRV isolates remained variable. Further analysis revealed that with exception of a few positively selected codons, a major part of the PLRV genome is evolving under strong purifying selection. Protein disorder prediction analysis revealed that CP-RTD had the highest percentage (48%) of disordered amino acids and the majority (27%) of disordered residues were positioned at the C-terminus. These findings will extend our current knowledge of the PLRV geographical prevalence, genetic diversity, and evolutionary factors that are presumably shaping the global spread and successful adaptation of PLRV as a destructive potato pathogen to geographically isolated regions of the world
Predominant porB1A and porB1B genotypes and correlation of gene mutations with drug resistance in Neisseria gonorrhoeae isolates in Eastern China
Manipulating backbone structure with various conjugated spacers to enhance photovoltaic performance of D–A-type two-dimensional copolymers
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