Bioactive phenolic substances in industrially important tree species. Part 2: Knots and stemwood of fir species

Holzforschung ◽  
2004 ◽  
Vol 58 (6) ◽  
pp. 650-659 ◽  
Author(s):  
Stefan Willför ◽  
Linda Nisula ◽  
Jarl Hemming ◽  
Markku Reunanen ◽  
Bjarne Holmbom

Abstract Knots, i.e. branch bases inside tree stems, in fir trees contained remarkably higher concentrations of lignans, oligolignans, and juvabiones than the adjacent stemwood. Eight fir species were analysed (Abies sibirica, A. lasiocarpa, A. balsamea, A. alba, A. amabilis, A. veitchii, A. sachalinensis, and A. concolor). The amount of lignans could in some knots exceeds 6% (w/w) and the knots generally contained 20–50 times more lignans than the stemwood. However, there were large variations, not only between species but also even between knots in the same tree. Secoisolariciresinol was the predominant lignan in all knots. The lignans occur in free form in the knots and are easily extracted with polar solvents. In addition to the lignans, oligomeric aromatic substances, mainly sesquineo- and dineolignans, and juvabiones were accumulated in the knotwood. Secoisolariciresinol, but also lariciresinol (Abies alba) and 7-hydroxymatairesinol (A. amabilis), could be extracted in large scale from fir knots at pulp and paper mills. The ready availability of large amounts of lignans and oligolignans now enables research to assess their bioactivity and provide the base for applications in medicine and nutrition, or as natural antioxidants and antimicrobial agents in various technical products.

Holzforschung ◽  
2004 ◽  
Vol 58 (4) ◽  
pp. 335-344 ◽  
Author(s):  
S. Willför ◽  
L. Nisula ◽  
J. Hemming ◽  
M. Reunanen ◽  
B. Holmbom

Abstract Knots (i.e., branch bases inside tree stems) in spruce trees contained remarkably higher concentrations of lignans and oligolignans than the adjacent stemwood. The amount of lignans in some knots exceeded 10% (w w−1) and some knots contained hundreds of times more lignans than the heartwood in the same tree. However, there were large variations between different species and even between different knots in the same tree. 7-Hydroxymatairesinol was the predominant lignan in knots of Picea abies, P. glauca, P. koraiensis, P. mariana, and P. omorika, while liovil and secoisolariciresinol dominated in P. sitchensis and P. pungens. The lignans occur in free form in knots and are easily extracted with polar solvents. In addition to the true lignans, especially the knots contained large amounts of lignan-related oligomeric aromatic substances, here called oligolignans, consisting of three or four phenylpropane units. 7-Hydroxymatairesinol, but also other lignans, could be extracted in large scale from spruce knots at pulp and paper mills. Other potentially important lignans could be produced from 7-hydroxymatairesinol by semisynthesis. The ready availability of large amounts of lignans and oligolignans now enables research to assess their bioactivity and provide the basis for applications in medicine and nutrition or as natural antioxidants and antimicrobial agents in a variety of technical products.


Author(s):  
Lianli Gao ◽  
Pengpeng Zeng ◽  
Jingkuan Song ◽  
Yuan-Fang Li ◽  
Wu Liu ◽  
...  

To date, visual question answering (VQA) (i.e., image QA and video QA) is still a holy grail in vision and language understanding, especially for video QA. Compared with image QA that focuses primarily on understanding the associations between image region-level details and corresponding questions, video QA requires a model to jointly reason across both spatial and long-range temporal structures of a video as well as text to provide an accurate answer. In this paper, we specifically tackle the problem of video QA by proposing a Structured Two-stream Attention network, namely STA, to answer a free-form or open-ended natural language question about the content of a given video. First, we infer rich longrange temporal structures in videos using our structured segment component and encode text features. Then, our structured two-stream attention component simultaneously localizes important visual instance, reduces the influence of background video and focuses on the relevant text. Finally, the structured two-stream fusion component incorporates different segments of query and video aware context representation and infers the answers. Experiments on the large-scale video QA dataset TGIF-QA show that our proposed method significantly surpasses the best counterpart (i.e., with one representation for the video input) by 13.0%, 13.5%, 11.0% and 0.3 for Action, Trans., TrameQA and Count tasks. It also outperforms the best competitor (i.e., with two representations) on the Action, Trans., TrameQA tasks by 4.1%, 4.7%, and 5.1%.


2020 ◽  
Vol 2020 ◽  
pp. 1-9 ◽  
Author(s):  
Phan-Canh Trinh ◽  
Le-Thi-Thanh Thao ◽  
Hoang-Tran-Viet Ha ◽  
TuAnh Nguyen

Asteraceae species were widely applied in traditional medicines in Asian countries as sources of natural antioxidants and antimicrobial agents. This study aimed to evaluate DPPH-scavenging capacities and antimicrobial activities of nine Asteraceae species collected from Southern Vietnam. Antioxidant and antimicrobial activities were determined by standard protocols. Essential oils from Ageratum conyzoides, Helianthus annuus, and Artemisia vulgaris indicated significant inhibitory effects on Staphylococcus aureus and Candida spp. Crude extracts and fractions from Taraxacum officinale, Chrysanthemum morifolium, A. conyzoides, and Tagetes erecta showed inhibitory ability on at least one testing bacterial strains including S. aureus, Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa. In a study on clinical isolates, ethyl acetate fraction from A. conyzoides flower displayed the most potent effect on uropathogenic E. coli and K. pneumoniae with MIC at 1.25–10 mg/ml and 5–12.5 mg/ml, respectively. DPPH-scavenging assay indicated that T. erecta extract had the lowest IC50 (17.280 μg/ml) and is 2.4 times higher than vitamin C (7.321 μg/ml). This study revealed that A. conyzoides has good potential against uropathogenic E. coli and K. pneumoniae, and therefore could be applied for prophylactic treatment of urinary infection.


2021 ◽  
Author(s):  
Lu Yang ◽  
Yingbo Shen ◽  
Junyao Jiang ◽  
Xueyang Wang ◽  
Dongyan Shao ◽  
...  

Abstract Antimicrobial agents have been used in meat production for decades and its consumption is considered an key driver for the emergence and dissemination of antimicrobial resistance (AMR). However, large-scale studies on AMR changes in animal isolates since the introduction of antimicrobial usage remain scarce. We applied whole genome sequencing analysis to 982 animal-derived Escherichia coli collected in China from 1970s to 2019 and found increasing trends for the presence of numerous antimicrobial resistance genes (ARGs), including those conferring resistance to critically important agents for veterinary (florfenicol and norfloxacin) and human medicine (colistin, cephalosporins, and meropenem). Extensive diversity and increasing complexity of ARGs and their associated mobile genetic elements (MGEs) such as plasmids were also observed. The plasmids, IncC, IncHI2, IncK, IncI, IncX and IncF played a key role as highly effective vehicles for disseminating ARGs. Correlation analysis also revealed an association between antimicrobial production and emergence of ARGs at a spatial and temporal level. Prohibiting or strictly curtailing antimicrobial use in animals will potentially negate the current trends of AMR as the bacterial genome is highly changeable and using different drugs of the same class, or even unrelated classes, may co-select for MGEs carrying a plethora of co-existing ARGs. Therefore, limiting or ceasing antimicrobial use in animals to control AMR requires careful consideration.


1972 ◽  
Vol 2 (3) ◽  
pp. 205-209
Author(s):  
Herbert R. Mosley

Recent approaches to computerized index preparation have failed to accommodate the flexible nature of index entries and could only be run on large-scale dp systems. A free-form approach is described which allows the author to be as creative in his indexing as he is in his writing. Tailoring the procedure to the facilities of the dp department enables the index to be prepared on a computer system of almost any size.


2021 ◽  
Author(s):  
David Crookall ◽  
Isabel Caballero-Leiva ◽  
Laksh Sharma ◽  
Pimnutcha Promduangsri ◽  
Pariphat Promduangsri

<p>Modern, educational simulation/games (s/g) have a rich legacy, stretching back to the 1960s.  They are used today for communicating science in educational, environmental or governmental organizations.  Other uses are to help groups and organizations conduct research, solve complex problems or make collective decisions.</p><p>Over the last two decades, a particularly powerful, but underused, form of s/g has developed, called participatory simulation (PS).  It contains (elements of) game, simulation, role-play, experience, human interaction, decision-making, negotiation, engagement, stakeholder, etc.  It is often large scale, open ended, goal and results oriented, free form and data driven.  Of course, debriefing is a crucial component.</p><p>Last summer (2020), the International Oceans-Climate School (IOCS), of the Ocean Open University (OOP), France, planned to organize an in-person summer school with a PS as its capstone event.  We then postponed and made it an autumn school.  It then became clear that this also was impossible, and so, after some hesitation, we scrambled to turn it into an online PS (OPS).</p><p>The theme was “<em>The Mediterranean and climate change: Impacts, people, action</em>”.  Our overarching goal was to help participants understand the <strong>oceans-climate nexus</strong> and to become better <strong>ocean-climate-literate stakeholders</strong>.  The IOCS is an official event of the <strong>Intergovernmental Oceanographic Commission</strong> (IOC) of UNESCO, as part of the <strong>UN Decade of Ocean Science for Sustainable Development</strong>.</p><p>The school ran over three days, with the OPS over two days.  We searched for a platform that would accommodate the flexibility needed for the OPS; we chose Discord.  We had participants originating from Brazil, France, India, Italy, Iran, Spain, Tunisia and the UK; ages ranged from 19 to 60 years.  It was a great success.  A detailed, online feedback form two weeks after the event collected participants’ opinions, including:</p><ul><li><em>“It was a wonderful experience.”, :I felt very good with all the participants.”, “When I describe the experience to friends I always say that it was something really useful for my personal and professional growth.”, “It was a very enriching experience for me to meet all these people with different training and knowledge, coming from different countries.”, “Enriching moments, so much more to discover.”, “What a great experience! I felt happy, engaged and surrounded by beautiful minds.”</em></li> </ul><p>We will run the event again in the Spring and the late summer or autumn, with different geoscience themes.  The success of the October 2020 event raises several research questions, including:</p><ul><li>How do the online and the in-person versions compare?</li> <li>What are the advantages and drawbacks of each?</li> <li>Which is more effective for what objectives and what results?</li> <li>How do the two versions stack up in regard to conducting research on such events?</li> <li>What are the implications of OPS for geoliteracy?</li> </ul><p>Our presentation will describe the event in more detail, offer tentative answers to the above questions, and help you decide if you wish to participate in the next event.  Co-authors include both organizers and participants.</p>


Catalysts ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1382
Author(s):  
Ilaria De Pasquale ◽  
Chiara Lo Porto ◽  
Massimo Dell’Edera ◽  
Francesca Petronella ◽  
Angela Agostiano ◽  
...  

Pathogenic microorganisms can spread throughout the world population, as the current COVID-19 pandemic has dramatically demonstrated. In this scenario, a protection against pathogens and other microorganisms can come from the use of photoactive materials as antimicrobial agents able to hinder, or at least limit, their spreading by means of photocatalytically assisted processes activated by light—possibly sunlight—promoting the formation of reactive oxygen species (ROS) that can kill microorganisms in different matrices such as water or different surfaces without affecting human health. In this review, we focus the attention on TiO2 nanoparticle-based antimicrobial materials, intending to provide an overview of the most promising synthetic techniques, toward possible large-scale production, critically review the capability of such materials to promote pathogen (i.e., bacteria, virus, and fungi) inactivation, and, finally, take a look at selected technological applications.


2016 ◽  
Vol 87 (10) ◽  
pp. 1226-1241
Author(s):  
Vignaesh Sankaran ◽  
Steffen Rittner ◽  
Lars Hahn ◽  
Chokri Cherif

The possibility of direct preforming in the near net shape of final component structure with load- and shape-conforming fiber orientations is highly essential in composite production, not only to reduce costs but also to attain better mechanical properties and form stability. Based on the concept of varying the reinforcement yarn lengths during the feed-in (warp yarn delivery) and segmented doffing, synchronous working numerically controlled warp yarn delivery and doffing machine modules have been newly developed for multiaxial warp knitting machines to create a resource efficient textile process chain by a single-step, large-scale oriented production of load- and form-conforming warp knitted three-dimensional shell preforms with free-form geometrical surfaces. Such customized preforms in the near component net shape offer higher material utilization and increased lightweight potential.


2019 ◽  
Author(s):  
Pedro J Silva

Extensive computational studies of the imine synthesis from amines and aldehydes in water have shown that the large-scale structure of water is needed to afford appropriate charge delocalisation and enable sufficient transition state stabilisation. These insights cannot, however, be applied to the understanding of the reaction pathway in apolar solvents due their inability to form extensive hidrogen-bonding networks. In this work, we perform the first computational studies of this reaction in apolar conditions. This density-functional study of the reaction of benzaldehyde with four closely related aromatic amines (aniline, o-toluidine, m-toluidine and p-toluidine) shows that an additional molecule of amine may provide enough stabilization of the first transition state even in the absence of a hydrogen bonding network. Our computations also show that the second reaction step cannot take place unless an extra proton is added to the system but, crucially, that reaction rate is so high that even picomolar amounts of protonated base are enough to achieve realistic rates. Additional computations show that those minute amounts of protonated base may be obtained under reaction conditions without the addition of extraneous acid through the auto-protolysis of the amines themselves. To our knowledge, this is the first report of a role for the auto-protolysis of anilines in their extensive reactional repertoire.


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