课程文献中心 更多>>

关键词： 医教协同   临床医学   生物化学   泛雅平台   微信公众平台  

摘要： 在医教协同背景下,加强医学人才培养是深化高等教育综合改革的重要任务。然而,传统的生物化学课堂教学模式已经无法满足当代高素质医学人才的培养。信息化时代促进了线上教学的开展,本文借助泛雅平台构建生物化学优质网络教学课程,运用微信公众平台适时推送课程内容,并通过微信群与学生进行即时沟通互动和答疑,辅助生物化学传统课堂教学,培养学生自主学习能力,实现学生个性化学习。

关键词： Allelopathy   Antioxidant enzymes   2-Benzoxazolinone   Kinetin   Phenylalanine ammonia lyase   Vigna radiata   SUPEROXIDE-DISMUTASE   LIPID-PEROXIDATION   OXIDATIVE STRESS   LETTUCE   BOA   ALLELOCHEMICALS   ANTIOXIDANTS   GERMINATION   REDUCTASE   GROWTH  

摘要： Cytokinins are growth regulators concerned with influencing numerous plant metabolic and stress adaptive mechanisms under adversity. The present investigation was conducted to study the role of kinetin (KN) in ameliorating the damaging effects of allelochemical 2-benzoxazolinone (BOA) on Vigna radiata seedlings. The experiment was undertaken in sand culture under glasshouse conditions where plants were exposed to BOA (1 and 1.5 mM) by root and KN (1 mM) foliarly and then sampled for different growth parameters. BOA at both concentrations induced growth retardation which was more pronounced at the higher dose (1.5 mM). BOA toxicity gradually decreased photosynthetic pigment, relative water, protein, anthocyanin content, nitrate reductase activity and antioxidant enzyme activity. On contrary, enhanced electrolyte leakage (EL), lipid peroxidation (LP), hydrogen peroxide (H2O2), proline content and phenylalanine ammonia lyase activity (PAL). The foliar KN supplementation assisted in growth restoration by influencing several physiobiochemical attributes. KN-induced growth amelioration was reflected as reduced generation of reactive oxygen species and membrane stability with reduced LP and EL. The seedlings exposed to combined BOA and KN treatment exhibited higher antioxidant enzyme activity and total phenolic content (TPC) coupled with proline accumulation which play significant role in combating stress efficiently. The results revealed that KN has potential to buttress the defence system of crops grown in soil having higher BOA content. In future, research emphasis should be given on gene regulation mechanisms by allelopathins in plant system.

关键词： Serine protease   Geobacillus   Thermostability   Surfactant  

摘要： Proteases account for approximately 60% of the enzyme market in the world, and they are used in various industrial applications including the detergent industry. In this study, production and characterization of a novel serine protease of thermophilic Geobacillus sp. GS53 from Balcova geothermal region, Izmir, Turkey, were performed. The thermostable protease was purified through ammonium sulfate precipitation and anion-exchange chromatography. The results showed that the protease had 137.8 U mg(-1) of specific activity and optimally worked at 55 C-o and pH 8. It was also active in a broad pH (4-10) and temperature (25-75 degrees C) ranges. The protease was highly stable at 85 degrees C and demonstrated relative stability at pH 4, 7, and 10. Also, the enzyme had high stability against organic solvents and surfactants; enzyme relative activity did not decrease below 81% upon preincubation for 10 min. Ca2+, Cu2+, and Zn2+ ions slightly induced protease activity. The protease was highly specific to casein, skim milk, Hammerstein casein, and BSA substrates. These results revealed that the protease might have a potential effect in a variety of industrial fields, especially the detergent industry, because of its high thermostability and stability to surfactants.

关键词： Seaweed   Preservation   Downstream processing   Protein   Alginate   Biogas   CHEMICAL-COMPOSITION   ANAEROBIC-DIGESTION   LAMINARIA-DIGITATA   SEASONAL-VARIATION   DRYING TREATMENT   BROWN SEAWEEDS   PROTEIN   SARGASSUM   PRECIPITATION   DEGRADATION  

摘要： Saccharina latissima biomass cultivated along the Swedish west coast was subjected to four different scalable preservation methods after harvest; freezing, sun-drying, oven-drying and ensiling. Freeze-drying and freezing at -80 ?C were also included to provide dry and wet references. The effects of the different preservation methods on the composition of Saccharina biomass (on dry weight, DW, basis), and the recovery as well as properties of high-quality protein, alginate and biogas were evaluated. Sun-drying significantly reduced protein, alginate and fatty acid content of the seaweeds and thereby concentrated ash in the biomass compared to the other methods. Protein/amino acids and fatty acids were significantly concentrated in ensiled biomass, while mannitol and laminarin were reduced compared to the other biomasses. Oven-drying and -20 ?C freezing affected the composition the least, with lower ash content and alterations in some specific amino and fatty acids. Sun-drying and ensiling resulted in significantly lower protein solubility at high pH compared to the other biomasses which translated into the lowest total seaweed protein recovery using the pH-shift process. Highest protein yield was obtained with the freeze-dried reference. Ensiling lead to a significant decrease in the molecular weight of alginate, while sun-drying caused a negative effect on alginate by inducing a shift in the guluronic and mannuronic acids composition of alginate. Sun-drying gave the lowest methane yield in the anaerobic digestion experiments while freezing at -80 ?C gave the highest yield, closely followed by freezing at -20 ?C and ensiling. To conclude, preservation methods must be carefully chosen to protect the valuable component in Saccharina latissima, and to achieve an efficient downstream processing ultimately yielding high quality products as part of a seaweed biorefinery.

关键词： Autism spectrum disorder   Sulfur amino acids   S-adenosylmethionine   Hypomethylation   Radical SAM   Metabotype   CEREBRAL FOLATE-DEFICIENCY   METHYLTRANSFERASE VAL158MET POLYMORPHISM   S-ADENOSYLHOMOCYSTEINE HYDROLASE   PROTECTS DOPAMINERGIC-NEURONS   OXIDATIVE STRESS   MITOCHONDRIAL DYSFUNCTION   DNA METHYLATION   P-CRESOL   COPROPORPHYRINOGEN OXIDASE   TRANSSULFURATION PATHWAY  

摘要： There are multiple lines of evidence for an impaired sulfur amino acid (SAA) metabolism in autism spectrum disorder (ASD). For instance, the concentrations of methionine, cysteine and S-adenosylmethionine (SAM) in body fluids of individuals with ASD is significantly lower while the concentration of Sadenosylhomocysteine (SAH) is significantly higher as compared to healthy individuals. Reduced methionine and SAM may reflect impaired remethylation pathway whereas increased SAH may reflect reduced S-adenosylhomocysteine hydrolase activity in the catabolic direction. Reduced SAM/SAH ratio reflects an impaired methylation capacity. We hypothesize multiple mechanisms to explain how the interplay of oxidative stress, neuroinflammation, mercury exposure, maternal use of valproate, altered gut microbiome and certain genetic variants may lead to these SAA metabotypes. Furthermore, we also propose a number of mechanisms to explain the metabolic consequences of abnormal SAA metabotypes. For instance in the brain, reduced SAM/SAH ratio will result in melatonin deficiency and hypomethylation of a number of biomolecules such as DNA, RNA and histones. In addition to previously proposed mechanisms, we propose that impaired activity of "radical SAM" enzymes will result in reduced endogenous lipoic acid synthesis, reduced molybdenum cofactor synthesis and impaired porphyrin metabolism leading to mitochondrial dysfunction, porphyrinuria and impaired sulfation capacity. Furthermore depletion of SAM may also lead to the disturbed mTOR signaling pathway in a subgroup of ASD. The proposed "SAM-depletion hypothesis" is an inclusive model to explain the relationship between heterogeneous risk factors and metabotypes observed in a subset of children with ASD. (c) 2021 Elsevier B.V. and Societe Francaise de Biochimie et Biologie Moleculaire (SFBBM). All rights reserved.

关键词： Aquaculture tail water   Nitrogen   Temperature   Macroalgae   Photosynthetic characteristic   Adaptability   NITRATE REDUCTASE-ACTIVITY   PHYSIOLOGICAL-RESPONSES   CARBONIC-ANHYDRASE   ULVA-PROLIFERA   WATER-QUALITY   ELEVATED CO2   FRESH-WATER   MARINE   AQUACULTURE   NUTRIENT  

摘要： Gracilaria blodgettii and Gracilaria lemaneiformis are often adopted as tools to purify aquaculture tail water. However, there has been such phenomenon that high temperature in summer restricts the process of aquaculture. To explore the adaptive capacity of G. blodgettii and G. lemaneiformis, we experimented them and cultured for 12 days under three temperatures (20, 25, and 30 degrees C) and three levels of multiple nitrogen sources (0.12, 0.6 and 4.4 mg L-1). Their growth, photosynthetic characteristics, and biochemical compositions including the contents of pigments and soluble protein were determined to investigate the single and interactive effects of temperatures and nitrogen levels on these two species. The results showed that in terms of G. blodgettii, the higher growth rate and more pigment (chlorophyll a and carotenoids) contents were observed at 25 and 30 degrees C in comparison to 20 degrees C, and the pigments showed maximum contents at 25 degrees C. More nitrogen improved the growth rate, net photosynthetic rate (P-n) at 25 and 30 degrees C, F-v/F-m at 20 degrees C, maximal photosynthetic electron transfer rate (ETRm), as well as soluble protein content at 20 and 25 degrees C. Additionally, the growth rate, P-n, and ETRm of G. lemaneiformis all showed a decline as increasing temperature; analogously high nitrogen concentration increased the growth rate at 25 and 30 degrees C, F-v/F-m at each temperature, ETRm, and pigments contents at 20 degrees C, as well as soluble protein content at 20 and 25 degrees C. Conclusions indicated that high temperature restricted the growth rate, inhibited photosynthetic characteristics, and decreased the soluble protein content of G. lemaneiformis. The reduced photosynthetic performance, pigments, and soluble protein contents of G. blodgettii were noted under similar conditions. However, nitrogen enrichment induced the greater resistant level to high temperature, and G. blodgettii showed better response. These findings s

关键词： Turnip   Cadmium   Hyperaccumulator   Flavonoid   Acetylation   RNA-SEQ DATA   GENOME-WIDE IDENTIFICATION   GLUTATHIONE METABOLISM   SULFUR ASSIMILATION   GENE FAMILIES   STRESS   EFFLUX   ZINC   ACCUMULATION   PROTEIN  

摘要： Cadmium (Cd) pollution is a prominent environment problem, and great interests have been developed towards the molecular mechanism of Cd accumulation in plants. In this study, we conducted combined transcriptomic, proteomic and biochemical approaches to explore the detoxification of a Cd-hyperaccumulating turnip landrace exposed to 5 mu M (T5) and 25 mu M (T25) Cd treatments. A total of 1090 and 2111 differentially expressed genes (DEGs) and 161 and 303 differentially expressed proteins (DEPs) were identified in turnips under T5 and T25, respectively. However, poor correlations were observed in expression changes between mRNA and protein levels. The enriched KEGG pathways of DEGs with a high proportion (> 80%) of upregulated genes were focused on the flavonoid biosynthesis, sulphur metabolism and glucosinolate biosynthesis pathways, whereas those of DEPs were enriched on the glutathione metabolism pathway. This result suggests that these pathways contribute to Cd detoxification in turnips. Furthermore, induced antioxidant enzymes, heat stock proteins and stimulated protein acetylation modification seemed to play important roles in Cd tolerance in turnips. In addition, several metal transporters were found responsible for the Cd accumulation capacity of turnips. This study may serve as a basis for breeding low-Cd-accumulating vegetables for foodstuff or high-Cd-abstracting plants for phytoremediation.

关键词： Prebiotic   Salt precipitation   Thermodynamic parameter   Xylanolytic enzyme   Xylooligosaccharide   BETA-XYLOSIDASE   THERMAL-PROPERTIES   SUGARCANE BAGASSE   ENDO-XYLANASE   NRRL Y-2311-1   CARBON SOURCE   PURIFICATION   BRAN   GALACTOSIDASE   STABILITY  

摘要： In this study, crude and partially purified xylanase from Aureobasidium pullulans CCT 1261 were characterized and applied in beechwood xylan hydrolysis to obtain xylooligosaccharides (XOS). Fractional precipitation (0?30 %/30?60 %) with ammonium sulfate allowed partial purification of xylanases in 6.8-fold and recovery of 69.4 %. Both extracts exhibited optimum activity at 50 ?C and pH 4.5, and greater stability at 40 ?C within the studied range. The thermostability parameters (kd, t1/2, ?H*, ?G*, ?S*) of the extracts indicated the enzyme denaturation by the increment in temperature from 40 ?C to 60 ?C; its process was endothermic and led to protein unfolding in a more random structure. Crude xylanase showed a lower value of the Michaelis-Menten constant (25 mg/mL) than the partially purified enzyme (50 mg/mL). In hydrolysis reactions, total XOS contents (7.7 mg/ mL and 7.9 mg/mL) and XOS yields (25.7 % and 26.5 %) were equal statistically using the crude or partially purified extracts, differing only in the amount of xylose released. The hydrolysates were mainly composed of potential prebiotics, i.e., xylobiose (50.9 % and 53.8 %) and xylotriose (30.9 % and 32.8 %). Based on these results, the use of crude and partially purified xylanase from A. pullulans showed a promising perspective for xylan hydrolysis to produce XOS.

关键词： Curcumin   Antioxidant activity   Cell death   Neuroinflammation   Methamphetamine neurotoxicity   PRO-INFLAMMATORY CYTOKINES   OXIDATIVE STRESS   CEREBRAL-ISCHEMIA   TNF-ALPHA   DOPAMINE   INJURY   BRAIN   NEUROINFLAMMATION   NEURODEGENERATION   INHIBITION  

摘要： Objective: Methamphetamine is used extensively around the world as a psychostimulant. The complications related to methamphetamine include methamphetamine-induced neurotoxicity, mainly involving intraneuronal processes, such as oxidative stress and excitotoxicity. Curcumin is effective against neuronal injury due to its antioxidant, anti-inflammatory effects. In this study, we examined the protective effects of curcumin against methamphetamine neurotoxicity. Methods: Sixty male Wistar rats were divided into the following groups: control (n = 12), DMSO (n = 12), methamphetamine (n = 12), and methamphetamine + curcumin (100 and 200 mg/kg, respectively, intraperitoneal [IP]; n = 12). Neurotoxicity was induced by 40 mg/kg of methamphetamine administrated through 4 injections (4 & times; 10 mg/kg, q2h, IP). Curcumin (100 and 200 mg/kg) was administered at 7 days after the last methamphetamine injection. By using a Morris water maze task, the hippocampus-dependent memory and spatial learning were evaluated 1 day after the last curcumin injection. Then, the animal brains were isolated for biochemical measurements, as well as glial fibrillary acidic protein (GFAP), ionized calcium-binding adaptor protein-1(Iba-1) and caspase-3 immunohistochemical staining. Results: The current study demonstrated that administration of curcumin significantly attenuates spatial memory impairment (P < 0.01) following methamphetamine neurotoxicity. Curcumin caused a significant increase in the levels of superoxide dismutase and glutathione peroxidase (P < 0.05). However, it decreased tumor necrosis factor (TNF-alpha) (P < 0.05) and malondialdehyde (P < 0.01) levels as compared to the methamphetamine group. Also, curcumin significantly reduced Iba-1 (P < 0. 01), GFAP and caspase-3 positive cells in the hippocampus (P < 0.001). Conclusion: Curcumin exerted neuroprotective effects on methamphetamine neurotoxicity because of its antioxidant and anti-inflammatory effect.

关键词： Biogas   Biomass   Anaerobic digestion   Waste management   Kinetic model   Methane   Agricultural waste  

摘要： This paper evaluates the anaerobic digestion of agricultural waste, manure and slaughterhouse residues of species typical of the Andes, such as llama, vicuna and guinea pig; quinoa, amaranth and wheat straw in order to be able to use them as a renewable energy source and boost rural development in the region. Has been used sludge from a WWTP as inoculum, evaluating the effect of two relationships between the substrate and inoculum (RSI) for both livestock and agricultural waste. The highest cumulative maximum methane production rate was obtained for the residues of flame manure and quinoa straw for an RSI of 1:2 with productions of 376.08 ml CH4/g SV and 377.02 ml CH4/g SV respectively. In these materials an RSI of 1:2 obtained increases of 22.56% and 37.54% compared to the RSI 1:1. Also, the kinetic analysis showed that the modified Gompertz model is the one that best fits performance, with constant differences of 7.06% between the experimental and predicted values. On the other hand, the modified Gompertz model was adjusted to the experimental results with an r(2) of (0.998) and an RMSE of 4.09 ml/g SV at 17.12 ml/g SV. (c) 2020 Elsevier Ltd. All rights reserved.