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11.
In response to herbivory by arthropods, plants emit herbivory-induced volatiles that attract carnivorous enemies of the inducing
herbivores. Here, we compared the attractiveness of eight cucumber varieties (Cucumis sativus L.) to Phytoseiulus persimilis predatory mites after infestation of the plants with herbivorous spider mites (Tetranychus urticae) under greenhouse conditions. Attractiveness differed considerably, with the most attractive variety attracting twice as
many predators as the least attractive variety. Chemical analysis of the volatiles released by the infested plants revealed
significant differences among varieties, both in quantity and quality of the emitted blends. Comparison of the attractiveness
of the varieties with the amounts of volatiles emitted indicated that the quality (composition) of the blend is more important
for attraction than the amount of volatiles emitted. The amount of (E)-β-ocimene, (E,E)-TMTT, and two other, yet unidentified compounds correlated positively with the attraction of predatory mites. Quantities
of four compounds negatively correlated with carnivore attraction, among them methyl salicylate, which is known to attract
the predatory mite P. persimilis. The emission of methyl salicylate correlated with an unknown compound that had a negative correlation with carnivore attraction
and hence could be masking the attractiveness of methyl salicylate. The results imply that the foraging success of natural
enemies of pests can be enhanced by breeding for crop varieties that release specific volatiles. 相似文献
12.
Rajendra P. Maskey Ines Kock Mohamed Shaaban Iris Grün-Wollny Elisabeth Helmke Frank Mayer Irene Wagner-Döbler Hartmut Laatsch 《Polymer Bulletin》2002,49(2-3):87-93
Summary
A new group of low-molecular weight channel-forming oligo(hydroxybutyric acids) (cPHBs, 1 with n = 8–30; main component MW ≈ 1300 dalton) was isolated from microorganisms of different origin. Inclusion bodies were
electron-microscopically visible in cells in the state of autolysis, not in cells in the exponential phase of growth. cPHB
and high-molecular poly(l3-hydroxybutyric acid) (sPHB) is cleaved by phenylethylamine and forms the corresponding monomeric
hydroxybutyramide and – under drastic conditions, the crotylamide. One of these compounds, the 3-hydroxy-N-phenethyl-butyramide
(5), was isolated as a new natural product now.
Received: 28 March 2002/Revised version: 26 July 2002/ Accepted: 26 July 2002
RID="*"
ID="*"Marine Bakterien, XVII. XVI: R.P. Maskey, R.N. Asolkar, E. Helmke, and H. Laatsch, Chalcomycin B, a new antibiotic from
a marine Streptomyces sp. B7064. J. Antibiot., submitted 2002
Correspondence to Hartmut Laatsch, e-mail: hlaatsc@gwdg.de, Fax: +49-551-399660 相似文献
13.
M. Valencia E. López S. Andrade Iris M.L. N. Guillén Hurtado V. Rico Pérez A. García García C. Salinas Martínez de Lecea A. Bueno López 《Topics in Catalysis》2013,56(1-8):452-456
The active phase Ce0.5Pr0.5O2 has been loaded on commercial substrates (SiC DPF and cordierite honeycomb monolith) to perform DPF regeneration experiments in the exhaust of a diesel engine. Also, a powder sample has been prepared to carry out soot combustion experiments at laboratory. Experiments performed in the real diesel exhaust demonstrated the catalytic activity of the Ce–Pr mixed oxide for the combustion of soot, lowering the DPF regeneration temperature with regard to a counterpart catalyst-free DPF. The temperature for active regeneration of the Ce0.5Pr0.5O2-containing DPF when the soot content is low is in the range of 500–550 °C. When the Ce0.5Pr0.5O2-containing DPF is saturated with a high amount of soot, pressure drop and soot load at the filter reach equilibrium at around 360 °C under steady state engine operation due to passive regeneration. The uncoated DPF reached this equilibrium at around 440 °C. Comparing results at real exhaust with those at laboratory allow concluding that the Ce0.5Pr0.5O2-catalysed soot combustion in the real exhaust is not based on the NO2-assisted mechanism but is most likely occurring by the active oxygen-based mechanism. 相似文献
14.
Iris B. A. W. te Paske Marjolijn J. L. Ligtenberg Nicoline Hoogerbrugge Richarda M. de Voer 《International journal of molecular sciences》2020,21(22)
To discover novel high-penetrant risk loci for hereditary colorectal cancer (hCRC) and polyposis syndromes many whole-exome and whole-genome sequencing (WES/WGS) studies have been performed. Remarkably, these studies resulted in only a few novel high-penetrant risk genes. Given this observation, the possibility and strategy to identify high-penetrant risk genes for hCRC and polyposis needs reconsideration. Therefore, we reviewed the study design of WES/WGS-based hCRC and polyposis gene discovery studies (n = 37) and provide recommendations to optimize discovery and validation strategies. The group of genetically unresolved patients is phenotypically heterogeneous, and likely composed of distinct molecular subtypes. This knowledge advocates for the screening of a homogeneous, stringently preselected discovery cohort and obtaining multi-level evidence for variant pathogenicity. This evidence can be collected by characterizing the molecular landscape of tumors from individuals with the same affected gene or by functional validation in cell-based models. Together, the combined approach of a phenotype-driven, tumor-based candidate gene search might elucidate the potential contribution of novel genetic predispositions in genetically unresolved hCRC and polyposis. 相似文献
15.
Iris Bakker Theo van der Voordt Peter Vink Jan de Boon Conne Bazley 《Color research and application》2015,40(1):62-71
Studies on color preferences are dependent on the topic and the relationships with personal characteristics, particularly personality, but these are seldom studied in one population. Therefore a questionnaire was collected from 1095 Dutch people asking for color preferences about different topics and relating them to personal characteristics. Color preferences regarding different topics show different patterns and significant differences were found between gender, age, education and personality such as being technical, being emotional or being a team player. Also, different colors were mentioned when asked for colors that stimulate to be quiet, energetic, and able to focus or creative. Probably, due to unconsciousness of contexts, many people had no color preference, a result that in the literature seldom is mentioned. Blue was the overall favorite color; however, most males chose for blue (25%) while most females had no color preference (18%). Black was the overall favorite color for clothing, mainly chosen by females (40%), while males primarily chose blue (27%). For building interiors subjects preferred white. For moods, subjects preferred white for being quiet or being able to focus, red for being energetic and had no color preference for being creative. It is concluded that color preferences are dependent upon the topic, and personal characteristics. The findings are important for architects, interior designers, fashion designers and product designers to have a basic idea of preferred colors for different objects by different types of people. © 2013 Wiley Periodicals, Inc. Col Res Appl, 40, 62–71, 2015 相似文献
16.
17.
Tetraacylgermanes as highly efficient photoinitiators for visible light cured dimethacrylate resins and dental composites 下载免费PDF全文
Norbert Moszner Urs Karl Fischer Iris Lamparth Pascal Fässler Judith Radebner Anna Eibel Michael Haas Georg Gescheidt Harald Stueger 《应用聚合物科学杂志》2018,135(15)
Tetrabenzoylgermane 1 and various substituted tetrabenzoylgermanes 2 – 7 were investigated as visible light (VL) photoinitiators (PIs) for dental dimethacrylate resins and dimethacrylate‐based composites. The tetrabenzoylgermanes 1 – 7 show a very strong VL absorption between 400 and 450 nm. Substituents on the benzoyl chromophore strongly influence their properties such as melting point, solubility, absorption behavior, or PI reactivity. A good photobleaching behavior and a very high reactivity as VL PI was found in photo‐differential scanning calorimeter experiments for selected tetrabenzoylgermanes. Composite pastes containing only ~0.1 wt % of Ge‐PI exhibited a sufficient photocuring due to the high PI‐reactivity of the tetraacylgermanes. Among the investigated germane PIs, tetrakis(2‐methylbenzoyl)germane 2 shows the best performance as VL PI for restorative composites and enables the composites to be photocured using an LED with an emission maximum of 500 nm. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46115. 相似文献
18.
Yang Ji Iris Yuwen Zhou Bensheng Qiu Phillip Zhe Sun 《Israel journal of chemistry》2017,57(9):809-824
Chemical exchange saturation transfer (CEST) MRI provides a sensitive detection mechanism for imaging dilute labile protons, complementing the routine radiological exams. Enormous progress has been achieved in CEST MRI and image analysis, from the mathematical modeling, CEST agent design, and most importantly, increasing adoption of CEST imaging in the clinical setting. Therefore, CEST imaging represents an emerging field that involves multiple disciplines and together made a remarkable transition from the simplistic CEST-weighted MRI to quantitative CEST (qCEST) analysis. This review focuses on the recent advancements in CEST quantification techniques and findings of in vivo CEST imaging in representative disorders of ischemia, tumor, and epilepsy. In addition, limitations of current CEST methodologies are examined that should help guide future development of more sensitive and quantitative CEST imaging techniques and ultimately, facilitate their adoption in the clinical setting. 相似文献
19.
Madalena C. Pinto Margarida C. Quaresma Iris A. L. Silva Violeta Railean Sofia S. Ramalho Margarida D. Amaral 《International journal of molecular sciences》2021,22(23)
SLC26A9, a constitutively active Cl− transporter, has gained interest over the past years as a relevant disease modifier in several respiratory disorders including Cystic Fibrosis (CF), asthma, and non-CF bronchiectasis. SLC26A9 contributes to epithelial Cl− secretion, thus preventing mucus obstruction under inflammatory conditions. Additionally, SLC26A9 was identified as a CF gene modifier, and its polymorphisms were shown to correlate with the response to drugs modulating CFTR, the defective protein in CF. Here, we aimed to investigate the relationship between SLC26A9 and CFTR, and its role in CF pathogenesis. Our data show that SLC26A9 expression contributes to enhanced CFTR expression and function. While knocking-down SLC26A9 in human bronchial cells leads to lower wt- and F508del-CFTR expression, function, and response to CFTR correctors, the opposite occurs upon its overexpression, highlighting SLC26A9 relevance for CF. Accordingly, F508del-CFTR rescue by the most efficient correctors available is further enhanced by increasing SLC26A9 expression. Interestingly, SLC26A9 overexpression does not increase the PM expression of non-F508del CFTR traffic mutants, namely those unresponsive to corrector drugs. Altogether, our data indicate that SLC26A9 stabilizes CFTR at the ER level and that the efficacy of CFTR modulator drugs may be further enhanced by increasing its expression. 相似文献
20.
Iris F. Kappers Francel W. A. Verstappen Ludo L. P. Luckerhoff Harro J. Bouwmeester Marcel Dicke 《Journal of chemical ecology》2010,36(5):500-512
Cucumber plants (Cucumis sativus L.) respond to spider–mite (Tetranychus urticae) damage with the release of specific volatiles that are exploited by predatory mites, the natural enemies of the spider mites,
to locate their prey. The production of volatiles also can be induced by exposing plants to the plant hormone jasmonic acid.
We analyzed volatile emissions from 15 cucumber accessions upon herbivory by spider mites and upon exposure to jasmonic acid
using gas chromatography—mass spectrometry. Upon induction, cucumber plants emitted over 24 different compounds, and the blend
of induced volatiles consisted predominantly of terpenoids. The total amount of volatiles was higher in plants treated with
jasmonic acid than in those infested with spider mites, with (E)-4,8-dimethyl-1,3,7-nonatriene, (E,E)-α-farnesene, and (E)-β-ocimene as the most abundant compounds in all accessions in both treatments. Significant variation among the accessions
was found for the 24 major volatile compounds. The accessions differed strongly in total amount of volatiles emitted, and
displayed very different odor profiles. Principal component analysis performed on the relative quantities of particular compounds
within the blend revealed clusters of highly correlated volatiles, which is suggestive of common metabolic pathways. A number
of cucumber accessions also were tested for their attractiveness to Phytoseiulus persimilis, a specialist predator of spider mites. Differences in the attraction of predatory mites by the various accessions correlated
to differences in the individual chemical profiles of these accessions. The presence of genetic variation in induced plant
volatile emission in cucumber shows that it is possible to breed for cucumber varieties that are more attractive to predatory
mites and other biological control agents. 相似文献