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关键词： Tetranychidae   Phytochemical   Acaricidal   Ovicidal   Antioxidant enzyme   Detoxification enzyme  

摘要： Natural pesticides are potential alternatives to conventional chemical pesticides. Recently, studies on pesticide-pest interactions have combined empirical biochemical measurements and practical field experiments. In this study, we performed laboratory and field efficacy analysis and biochemical characterization of two phytochemicals (2,4-di-tertbutylphenol (DTBP) and ethyl oleate (EO)) for carmine spider mite Tetranychus cinnabarinus control. DTBP and EO controlled mites by inhibiting egg hatchability and showed significant residual toxicity in laboratory tests. The control efficacy was confirmed in eggplant and cucumber field trials in three provinces in China. Oxidative stress induced by antioxidant enzymes (superoxide dismutase and peroxidase) and detoxification metabolism (involving carboxylesterase and/or mixed-function oxidase) may be involved in the response of mites to DTBP and EO. This study demonstrates the potential of DTBP and EO as effective acaricides for the control of spider mites and provides researchers a better understanding of acaricide-mite interactions.

关键词： Partial substitution of chemical nitrogen with organic nitrogen   Rice productivity   Soil enzymes   Microbial composition   Paddy ecosystem  

摘要： Substitution of chemical fertilizers with organic amendments recycle organic wastes and minimizes adverse environmental effects of mineral-fertilizer overuse. In China, cropping systems which utilize two rice plantings per year are the most important planting pattern for ensuring food security. To date, few studies have comprehensively evaluated the responses of soil fertility and rice performance in double rice cropping systems to the partial substitution of chemical nitrogen (N) with organic N under the same input rates of N, P and K. In addition, the influences of the mineral-to-organic substitution ratio and season on these responses remain poorly understood. Here, a 34-year field fertilizer trial was sampled to determine the impacts of organic substitution regime and growing season on soil biochemical properties and rice yield. Compared with the mineral NPK fertilizer regime, the replacement of 30 %, 50 % and 70 % of total N with organic N increased the yield of early rice by 4.5 %-8.3 %, respectively and that of late rice by 6.7 %-9.6 %. Moreover, the organic substitution regimes significantly improved soil biochemical indicators. The higher organic N substitution percentage resulted in higher values of many soil properties with the exception of TC:TN, fungi:bacteria and G(+):G(-), which tended to decrease with increasing substitution. Both fertilizer regime and growing season affected soil nutrient contents, enzyme activity and microbial community structure. The relative abundances of identified PLFA biomarkers 16:1 omega 5c, 16:10 omega 7c and 18:1 omega 7c were markedly higher (p <= 0.05) in the organic alternative treated soils than the NPK-treated soils in both seasons. Our results suggest that the substitution of 70 % chemical N with organic N is the most effective fertilizer practice for improving soil fertility and rice yield in double rice cropping systems.

关键词： Tick   Ixodes persulcatus   Methionine aminopeptidase   Enzymatic activity  

摘要： Methionine aminopeptidases (MetAPs), which remove the initiator methionine from nascent peptides, are essential in all organisms and considered to be a valuable targets for the treatment of various diseases, including cancer, malaria, and bacterial infections. However, MetAPs have not been reported in hard ticks (family Ixodidae), and their bioinformatics characterisation in tick's genome sequences is limited. In this study, we cloned, identified, and characterised a novel MetAP from Ixodes persulcatus, a vector for pathogens causing Lyme borreliosis and tick-borne encephalitis. The sequence analysis showed that I. persulcatus MetAP was a type 1 enzyme carrying CC-terminal motifs conserved in the M24A family of metallopeptidases. Protein-protein docking simulations using human MetAP revealed conservation of substrate and metal-binding residues in the catalytic site cleft of the novel enzyme, which was designated IpMetAP. Recombinant IpMetAP expressed in Escherichia coli revealed its significant enzymatic activity with the synthetic substrate H-Met-4-methyl-coumaryl-7-amide at pH 7.5 with K-m of 0.014 mM, k(cat) of 0.25 s(-1), and overall catalytic efficiency (k(cat)/K-m) of 18.36 mM(-1) s(-1). The activity of IpMetAP was enhanced by the addition of divalent cations Mn2+ and Co2+ and significantly inhibited by EDTA and bestatin. Site-directed mutagenesis of conserved amino acids indicated that the substitution of metal-binding residues D226 and H288 completely abolished the IpMetAP enzymatic activity, whereas that of the other sites had only moderate effects on substrate hydrolysis. The catalytic properties of IpMetAP suggest that the enzyme behaves similar to other MetAPs and such characterization expands our knowledge of aminopeptidases and protein metabolism of tick.

关键词： Epidemic prevention   Hemagglutinin   Monoclonal antibody   Epitope sequence  

摘要： The highly pathogenic avian influenza (HPAI) H5N8 virus has been detected in wild birds and poultry worldwide. The threat caused by HPAI H5N8 virus still exists with concerns for human infection. The preparedness for epidemic prevention and decreasing the agricultural and economic lost is extremely important. Hemagglutinin (HA), a surface glycoprotein of influenza viruses, is considered as the major target for detection of the influenza virus subtype in the infected samples. In this study, the recombinant H5N8 HA1 and HA2 proteins were expressed in Escherichia coli, and were utilized to generate two monoclonal antibodies, named 7H6C and YC8. 7H6C can bind the HA proteins of H5N1 and H5N8, but cannot bind the HA proteins of H1N1, H3N2, and H7N9, indicating that it has H5-subtype specificity. In contrast, YC8 can bind the HA proteins of H1N1, H5N1, and H5N8, but cannot bind the HA proteins of H3N2 and H7N9, indicating that it has H1-subtype and H5-subtype specificity. The epitope sequences recognized by 7H6C are located in the head domain of H5N8 HA, and are highly conserved in H5 subtypes. The epitope sequences recognized by YC8 are located in the stalk domain of H5N8 HA, and are highly conserved among the H1 and H5 subtypes. 7H6C and YC8 can be applied for specific detection of the HA proteins of H5N8 and H5Nx avian influenza viruses.

关键词： active learning   biochemistry   biomolecules   card sorting   game-based   novice expert   structure-function   visual literacy  

摘要： Introductory biochemistry courses are often challenging for students because they require the integration of chemistry, biology, physics, math, and physiology knowledge and frameworks to understand and apply a large body of knowledge. This can be complicated by students' persistent misconceptions of fundamental concepts and lack of fluency with the extensive visual and symbolic literacy used in biochemistry. Card sorting tasks and game-based activities have been used to reveal insights into how students are assimilating, organizing, and structuring disciplinary knowledge, and how they are progressing along a continuum from disciplinary novice to expert. In this study, game-based activities and card sorting tasks were used to promote and evaluate students' understanding of fundamental structure-function relationships in biochemistry. Our results suggest that while many markers of expertise increased for both the control and intervention groups over the course of the semester, students involved in the intervention activities tended to move further towards expert-like sorting. This indicates that intentional visual literacy game-based activities have the ability to build underdeveloped skills in undergraduate students.

关键词： Endoglucanase   Lignocellulose   Thermostable   Cellulase  

摘要： To develop new cellulases for efficient utilization of the lignocellulose, an endoglucanase (CoCel5A) gene fromColletotrichum orchidophilumwas synthesized and a recombinantPichia pastorisGS115/pPIC9K/cocel5A was constructed for secretory expression of CoCel5A. After purification, the protein CoCel5A was biochemically characterized. The endoglucanase CoCel5A exhibited the optimal activity at 55-75 degrees C and high thermostability (about 85% residual activity) at the temperature of 55 degrees C after incubation for 3 h. The highest activity of CoCel5A was detected when 100 mM citric acid buffer (pH 4.0-5.0) was used and excellent pH stability (up to 95% residual activity) was observed after incubation in 100 mM citric acid buffer (pH 3.0-6.0) at 4 degrees C for 24 h. Carboxymethyl cellulose sodium salt (n = approx. 500) (CMC) and beta-d-glucan were the best substrates for CoCel5A among the tested substrates. The kinetic parametersV(max),K-m, andK(cat)/K(m)values against CMC were 290.70 U/mg, 2.65 mg/mL, and 75.67 mL/mg/s, respectively;and 228.31 U/mg, 2.06 mg/mL, and 76.45 mL/mg/s against beta-d-glucan, respectively, suggesting that CoCel5A has high affinity and catalytic efficiency. These properties supported the potential application of CoCel5A in biotechnological and environmental fields.

关键词： short-chain carboxylic acids   bio-based products   patents   scientific papers   bioconversion   multicriteria analysis  

摘要： There are increasing environmental and economic demands for the production of chemicals of industrial interest from renewable resources. Among the renewable products, short-chain carboxylic acids (C1-C6) stand out due to their importance in many sectors of the economy. Within this class, a wide variety of acids are industrially valuable as the precursors of many other chemicals for different applications, technological solutions, and markets. This makes it difficult to identify the most promising from a technical and economic standpoint. In this work, data on scientific papers and patents published between 2008 to 2017, related to the main bio-based carboxylic acids, are used to identify the acids that are generating growing scientific and industrial interest. The biochemical processes in patents associated with the production of such acids are evaluated using a multicriteria approach that integrates valuation patent criteria. The results of this study show that acids that are of substantial commercial interest, such as acetic, citric, lactic, acrylic, and methacrylic acids, have the highest growth rate both in scientific papers and patents. In terms of biochemical processes, the multicriteria decision analysis showed that the most relevant processes described in patents were associated with 'drop-in' acids such as methacrylic, adipic, maleic, acrylic, and glutaric acids. There is also a clear indication of the emergence of studies on low volume acids such as acetoacetic, acetolactic, muconic, and levulinic acids. In conclusion, the analysis shows that emerging scientific and technological production is conservative, focusing on acids with established markets, especially for the substitution of petrochemicals for immediate demand. (c) 2020 Society of Industrial Chemistry and John Wiley & Sons Ltd

关键词： Magnetic resonance imaging   Positron-emission tomography   Prostate cancer   Robot-assisted radical prostatectomy  

摘要： Background/Purpose: We sought to compare the diagnostic performances of Ga-68-PSMA-11 PET/CT and prostate/whole-abdomen multiparametric magnetic resonance imaging (PWAmpMRI) in Taiwanese patients with biochemically recurrent prostate cancer following robot-assisted radical prostatectomy. Methods: Between June 2017 and December 2018, we prospectively enrolled 34 patients. Upon review of all available clinical and imaging data, a best valuable comparator (BVC) was defined on an individual basis in the light of a consensus reached by a multidisciplinary tumor board. Diagnostic positivity was investigated in relation to the different lesion types. Results: On a patient-based analysis, Ga-68-PSMA-11 PET/CT and PWAmpMRI showed a moderate agreement (kappa coefficient = 0.62). Ga-68-PSMA-11 PET/CT identified local recurrences, regional, and non-regional lymph node metastases, and bone metastases in 15, 10, 1, and 5 patients, respectively. Conversely, PWAmpMRI detected these lesions in 26, 8, 1, and 4 patients, respectively. When the BVC was used as reference standard, the positive diagnostic rates for local recurrences, regional lymph node metastases, non-regional lymph node metastases, and bone metastases were 57.7%, 90.9%, 100%, and 100%, respectively for Ga-68-PSMA-11 PET/CT, and 100%, 72.7%, 100%, and 80% for PWAmpMRI, respectively. The use of both PWAmpMRI and Ga-68-PSMA-11 PET/CT showed a complete diagnostic yield for detecting both local recurrence and systemic failure when PSA levels reached 0.5 ng/mL. Conclusion: Due to urine radioactivity, Ga-68-PSMA-11 PET/CT performs less than PWAmpMRI on local recurrences. However, it can have a complementary diagnostic role in the detection of lymph node metastases and in identifying non-axial bone metastases beyond the PWAmpMRI scanning field. Copyright (C) 2020, Formosan Medical Association. Published by Elsevier Taiwan LLC.

关键词： Redox reactions  

摘要： This study was performed to evaluate the effects of using native and commercial probiotic strains on biochemical, microbiological, and sensory properties of yogurt. The viability of probiotic bacteria in all samples exceeded 6 log CFU/ml required to provide health benefits. The native Iranian Lactobacillus casei showed the highest viability throughout storage (8.5 log CFU/ml at the end of storage). Three distinct phases were observed in pH, acidity, and redox potential during the fermentation of all samples. Commercial L. casei strain had the lowest mean acidity increase rates and the longest incubation times. The growth of Lactobacillus delbrueckii ssp. Bulgaricus and Streptococcus thermophilus in probiotic yogurt was improved compared to the control yogurt. The control sample had the lowest score in all sensory parameters evaluated. Overall, yogurt containing native Iranian L. casei strain is recommended because of its good sensory and microbial properties. Practical applications Among different functional food products, probiotic dairy products are of great interest and yogurt is the most popular probiotic carrier. In most cases, commercial strains of Lactobacillus and bifidobacteria are incorporated into yogurt and native strains have not been studied widely. In this regard, isolation, characterization, and investigation of the effect of their application in dairy products can be promising in the development of functional dairy products with acceptable qualitative characteristics.

关键词： biosensor   biochemical oxygen demand (BOD5)   poly(vinyl alcohol)   N-vinylpyrrolidone   association of microorganism   immobilization in layer-by-layer films  

摘要： A new approach has been developed for the formation of the biosensor recognition elements via the immobilization of microorganisms in layer-by-layer films in order to determine the biochemical oxygen demand (BOD). Bioreceptor elements of BOD-biosensors have been fabricated based on the bacterial microorganisms Paracoccus yeei, Pseudomonas veronii, and Bacillus proteolyticus isolated from activated sludge. The recognition element was formed with via layer-by-layer deposition;each layer contained cells of one species. A similar multilayered recognition element based on yeast cells of Ogataea angusta, Blastobotrys adeninivorans, and Debaryomyces hansenii was created. In both cases, the cells were immobilized in a hydrogel of polyvinyl alcohol modified with N-vinylpyrrolidone. It was found that layer-by-layer immobilization increases the sensitivity of both the yeast- and bacterial cell-based biosensors. It was surmised that this is due to the lack of competition for substrate within the layer and its greater ability to each of the cell layers. The effects of the composition of the assayed samples (pH, ionic strength, heavy metal compounds) on the oxidative activity of the developed recognition elements have been studied. The analytical and metrological characteristics of the biosensors have been defined. The lower limit of the estimated BOD5 values was 0.5 mg O-2/dm(3) and 0.7 mg O-2/dm(3) for bacterial- and yeast cell-based biosensors, respectively. BOD5 was detected in water samples with the fabricated recognition elements. It was shown that the use of these two bioreceptors makes it possible to obtain data that strongly agree with those obtained with traditional method and that biosensing analyzers can act as prototype pilot model of the devices