scholarly journals Phyllotaxic diversity in Magnolia flowers

2014 ◽  
Vol 63 (2) ◽  
pp. 117-137 ◽  
Author(s):  
Beata Zagórska-Marek
Keyword(s):  
Genetic Factor ◽  
Wide Spectrum ◽  
Periodic Distribution ◽  
Pattern Diversity ◽  
First Time

Impermanent initials and thus the shift of the axis in the stochastic meristems are postulated to be responsible for ontogenetic phyllotactic diversity in plants. In the gynoecium of <i>Magnolia acuminata</i> the main Fibonacci pattern develops in much less than 50% of individual generative shoots. There is also an extremely wide spectrum of other patterns, among them even the rarest I, 3, 8, 11 ... pattern is present. Regarded sometimes as "impossible", the pattern has been documented in SEM for the first time. Beside the presence of various patterns, frequent ontogenetic transformations of phyllotaxis have been found in <i>Magnolia</i>. These are indicated by dislocations in the periodic distribution of carpel primordia. In other magnolias, exemplified by <i>M. soulangeana</i>, the Fibonacci pattern prevails, but not as much as in coniferous vegetative shoots, where, as demonstrated earlier, it reaches 95%. Other pattern numbers are also different. This suggests the involvement of the genetic factor and may be attributed to the higher frequency of discontinuous phyllotactic transformations in some species. The stochastic character of the meristem is perhaps more pronounced in some plants, which leads in turn to more frequent transitions and greater pattern diversity.

New Principles of the Substructure Development in Metal Materials under Plastic Deformation, Revealed by Advanced X-Ray Methods

2004 ◽  
Vol 443-444 ◽  
pp. 259-262 ◽  
Author(s):  
Yuriy Perlovich ◽  
Margarita Isaenkova
Keyword(s):  
Wide Spectrum ◽  
Residual Deformation ◽  
Ray Method ◽  
Computer Data ◽  
Rolled Material ◽  
X Ray ◽  
Pole Figures ◽  
Metal Materials ◽  
First Time ◽  
Ray Methods

The substructure inhomogeneity of real textured metal materials was studied by use of the X-ray method of Generalized Pole Figures and the computer data treatment. Main regularities of substructure inhomogeneity were revealed for the first time. Substructure conditions of grains in rolled material form an extremely wide spectrum and vary by passing from texture maxima to texture minima, where residual deformation effects are most significant. The distribution of residual elastic microstrains in the orientational space of rolled material shows the distinct system.

scholarly journals Double the Chemistry, Double the Fun: Structural Diversity and Biological Activity of Marine-Derived Diketopiperazine Dimers

Marine Drugs ◽  
2019 ◽  
Vol 17 (10) ◽  
pp. 551 ◽  
Author(s):  
Nelson G. M. Gomes ◽  
Renato B. Pereira ◽  
Paula B. Andrade ◽  
Patrícia Valentão
Keyword(s):  
Wide Spectrum ◽  
Structural Diversity ◽  
Pharmacological Properties ◽  
Binding Ability ◽  
Recognition Sites ◽  
Naturally Occurring ◽  
Bioactive Properties ◽  
Models Of Disease ◽  
First Time ◽  
Biosynthetic Machinery

While several marine natural products bearing the 2,5-diketopiperazine ring have been reported to date, the unique chemistry of dimeric frameworks appears to remain neglected. Frequently reported from marine-derived strains of fungi, many naturally occurring diketopiperazine dimers have been shown to display a wide spectrum of pharmacological properties, particularly within the field of cancer and antimicrobial therapy. While their structures illustrate the unmatched power of marine biosynthetic machinery, often exhibiting unsymmetrical connections with rare linkage frameworks, enhanced binding ability to a variety of pharmacologically relevant receptors has been also witnessed. The existence of a bifunctional linker to anchor two substrates, resulting in a higher concentration of pharmacophores in proximity to recognition sites of several receptors involved in human diseases, portrays this group of metabolites as privileged lead structures for advanced pre-clinical and clinical studies. Despite the structural novelty of various marine diketopiperazine dimers and their relevant bioactive properties in several models of disease, to our knowledge, this attractive subclass of compounds is reviewed here for the first time.

scholarly journals Structural and Biochemical Studies of Dihydrofolate Reductase from Streptococcus pyogenes as a Target for Antifolate Antibiotics

2018 ◽  
Author(s):  
Behnoush Hajian ◽  
Jolanta Krucinska ◽  
Michael Martins ◽  
Narendran G-Dayanan ◽  
Kishore Viswanathan ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Streptococcus Pyogenes ◽  
Dihydrofolate Reductase ◽  
Wide Spectrum ◽  
Streptococcal Infections ◽  
Biochemical Studies ◽  
Live Bacteria ◽  
Dhfr Inhibitors ◽  
First Time ◽  
Structural Insights

ABSTRACTStreptococcus pyogenes, a beta-hemolytic bacterium, causes a wide spectrum of infections in human including pharyngitis, tonsillitis, scarlet fever, rheumatic fever, and necrotizing fasciitis. Streptococcal infections can also exist as co-infection with methicillin resistant Staphylococcus aureus (MRSA). Trimethoprim-sulfamethoxazole (TMP-SMX) combination has been used for treatment of S. pyogenes and MRSA co-infection. However, resistance to TMP, an inhibitor of dihydrofolate reductase enzyme (DHFR), has challenged the efficacy of TMP-SMX combination. We explored the activity of a series of novel DHFR inhibitors against S. pyogenes. This study identified potent inhibitors of DHFR enzyme from S. pyogenes with excellent inhibitory activity against the growth of the live bacteria. We determined, for the first time, the crystal structure of S. pyogenes DHFR which provides structural insights into design and development of antifolate agents against this global pathogen.

scholarly journals Chemical Ecology of Teak (Tectona grandis Linn.) Floral Volatiles

2020 ◽  
Vol 32 (11) ◽  
pp. 2693-2699
Author(s):  
P. Mohamed Shafi ◽  
M. Mohanakrishnan
Keyword(s):  
Chemical Ecology ◽  
Wide Spectrum ◽  
Tectona Grandis ◽  
Floral Volatiles ◽  
Volatile Profile ◽  
Oxygenated Compounds ◽  
First Time ◽  
Enormous Number ◽  
Effective Pollinators ◽  
Insect Visitors

In present work, the GC, GC-MS and GC-olfactory techniques were applied for the first time for the analysis of floral volatiles of teak. Chemical ecology of the teak flower is also studied by correlating each of the components in its volatile profile with the major classes of insect visitors and pollinators with the help of the internet databases. Sixty six components consisting of 84% of the oil were identified in the GC-MS analysis. Out of these 78% were oxygenated compounds while only 20% were various hydrocarbons, either sesquiterpenes or diterpenes. All the monoterpenes were in the oxidized form which reduces the therapeutic potentials of the oil while improving its perfumery value. The olfactory evaluation of the oil revealed the presence of a wide spectrum of impressions ranging from spicy-floral to mushroom-metallic and woody-earthy to honey-like. The main reason for the enormous number of insects visiting teak flower is the presence of large number of volatile compounds with diverge semiochemical behaviour. At the same time the presence of some specific allomones and alarm pheromones results in the repulsion of some effective pollinators. This leads to ineffective pollination and comparatively low fruit development in teak.

scholarly journals TLR9 and COVID-19: A Multidisciplinary Theory of a Multifaceted Therapeutic Target

2021 ◽  
Vol 11 ◽  
Author(s):  
Gillina F. G. Bezemer ◽  
Johan Garssen
Keyword(s):  
World War Ii ◽  
Wide Spectrum ◽  
The Novel ◽  
Vaccine Adjuvants ◽  
Drug Candidates ◽  
Vulnerable Patients ◽  
Medical Need ◽  
Thrombotic Complications ◽  
Novel Coronavirus ◽  
First Time

By mapping the clinical pathophysiology of the novel coronavirus disease 2019 (COVID-19) against insights from virology, immunology, genomics, epidemiology and pharmacology, it is here proposed that the pathogen recognition receptor called toll like receptor 9 (TLR9) might have a pivotal role in the pathogenesis of COVID-19. Severe Acute Respiratory Syndrome Coronavirus 2, is causing the greatest global social and economic disruption since world war II. Lack of a vaccine, lack of successful treatment and limitations of the healthcare workforce and resources needed to safeguard patients with severe COVID-19 on the edge of life, demands radical preventive measures. It is urgently needed to identify biomarkers and drug candidates so that vulnerable individuals can be recognized early and severe multi-organ complications can be prevented or dampened. The TLR9 COVID-19 hypothesis describes a mechanism of action that could explain a wide spectrum of manifestations observed in patients with severe COVID-19. The introduced hypothesis proposes biomarkers for identification of vulnerable individuals and positions TLR9 as a promising multifaceted intervention target for prevention and/or treatment of COVID-19. TLR9 agonists might have value as prophylactic vaccine adjuvants and therapeutic immune stimulators at the early onset of disease. Additionally, in this current manuscript it is proposed for the first time that TLR9 could be considered as a target of “inhibition” aimed to dampen hyperinflammation and thrombotic complications in vulnerable patients that are at risk of developing late stages of COVID-19. The readily availability of TLR9 modulating drug candidates that have reached clinical testing for other disorders could favor a fast track development scenario, an important advantage under the current high unmet medical need circumstances regarding COVID-19.

scholarly journals Consistency between Fourier transform and small-volume few-wave decomposition for spectral and spatial variability of gravity waves above a typhoon

2012 ◽  
Vol 5 (7) ◽  
pp. 1637-1651 ◽  
Author(s):  
C. I. Lehmann ◽  
Y.-H. Kim ◽  
P. Preusse ◽  
H.-Y. Chun ◽  
M. Ern ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Momentum Flux ◽  
Wide Spectrum ◽  
Three Dimensional ◽  
Phase Speed ◽  
Analysis Technique ◽  
Momentum Fluxes ◽  
Different Types ◽  
Wave Decomposition ◽  
First Time

Abstract. Convective gravity wave (GW) sources are spatially localized and emit at the same time waves with a wide spectrum of phase speeds. Any wave analysis therefore compromises between spectral and spatial resolution. Future satellite borne limb imagers will for a first time provide real 3-D volumes of observations. These volumes will be however limited which will impose further constraints on the analysis technique. In this study a three dimensional few-wave approach fitting sinusoidal waves to limited 3-D volumes is introduced. The method is applied to simulated GWs above typhoon Ewiniar and GW momentum flux is estimated from temperature fluctuations. Phase speed spectra as well as average profiles of positive, negative and net momentum fluxes are compared to momentum flux estimated by Fourier transform as well as spatial averaging of wind fluctuations. The results agree within 10–20%. The few-wave method can also reveal the spatial orientation of the GWs with respect to the source. The relevance of the results for different types of measurements as well as its applicability to model data is discussed.

scholarly journals Concurrent Course of Transient Neonatal Diabetes with Cholestasis and Paucity of Interlobular Bile Ducts: A Case Report

2009 ◽  
Vol 12 (5) ◽  
pp. 417-420 ◽  
Author(s):  
Alan P. Kenny ◽  
Nancy A. Crimmins ◽  
Deborah J.G. Mackay ◽  
Robert J. Hopkin ◽  
Kevin E. Bove ◽  
...  
Keyword(s):  
Bile Ducts ◽  
Time Course ◽  
Wide Spectrum ◽  
Uniparental Disomy ◽  
Neonatal Diabetes ◽  
Alagille Syndrome ◽  
Chromosome 6 ◽  
Similar Time ◽  
Transient Neonatal Diabetes ◽  
First Time

We report for the first time a patient with both transient neonatal diabetes mellitus (TNDM) and idiopathic neonatal cholestasis, with both features resolving over a similar time course. Cholestasis was due to paucity of interlobular bile ducts (PILBD). Genetic analysis was consistent with a uniparental disomy of chromosome 6. Paucity of interlobular bile ducts is common in Alagille syndrome but also occurs by unknown mechanisms in a wide spectrum of other diseases. We propose a shared explanation for this patient's TNDM and PILBD mediated by the noted chromosomal abnormality. We suggest that hepatobiliary function be evaluated in patients with TNDM to determine the prevalence and course of cholestasis of the disease.

scholarly journals Chemical alteration of the Pleistocene sediments under influence basaltic sills in the Guaymas Basin, Gulf of California

2019 ◽  
Vol 98 ◽  
pp. 08004
Author(s):  
Evgenii Goncharov ◽  
Victor Kurnosov ◽  
Yurii Konovalov ◽  
Alfred Geptner ◽  
Konstantin Galin ◽  
...  
Keyword(s):  
Gulf Of California ◽  
Wide Spectrum ◽  
Hydrothermal Systems ◽  
Ocean Drilling Program ◽  
Upper Pleistocene ◽  
Guaymas Basin ◽  
Ocean Drilling ◽  
Sediment Cover ◽  
Short Time ◽  
First Time

In Guaymas Basin of the Gulf of California Holes DSDP 478 и 481A were drilled (Ocean Drilling Program). Studying of the cores from the holes showed the alteration of chemical composition of sediments in zones of contacts with basaltic sills. In the altered sediments strong decreased content in the Corg. Especially strong it occurs in sediment, that is located between sills in complex of thin sills. In these sediments also strong decreased contentin the Li, Cu, As, Mo, Ag, Cd, Sb, Ta, W, Tl, Pb, Bi.For the first time in Upper Pleistocene sediments altered under conditions short-time hydrothermal systems that were formed by intruded sills into sediment cover was analysis wide spectrum of microelements, including rare earth elements.

scholarly journals Consistency between Fourier transform and small-volume few-wave decomposition for spectral and spatial variability of gravity waves above a typhoon

2012 ◽  
Vol 5 (1) ◽  
pp. 1763-1793
Author(s):  
C. I. Lehmann ◽  
Y.-H. Kim ◽  
P. Preusse ◽  
H.-Y. Chun ◽  
M. Ern ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Momentum Flux ◽  
Wide Spectrum ◽  
Three Dimensional ◽  
Phase Speed ◽  
Analysis Technique ◽  
Momentum Fluxes ◽  
Different Types ◽  
Wave Decomposition ◽  
First Time

Abstract. Convective gravity wave (GW) sources are spatially localized and emit at the same time waves with a wide spectrum of phase speeds. Any wave analysis therefore compromises between spectral and spatial resolution. Future satellite borne limb imagers will for a first time provide real 3d volumes of observations. These volumes will be however limited which will impose further constraints on the analysis technique. In this study a three dimensional few-wave appoach fitting sinusoidal waves to limited 3-D volumes is introduced. The method is applied to simulated GWs above typhoon Ewiniar and GW momentum flux is estimated from temperature fluctuations. Phase speed spectra as well as average profiles of positive, negative and net momentum fluxes are compared to momentum flux estimated by Fourier transform as well as spatial averaging of wind fluctuations. The results agree within 10–20%. The few-wave method can also reveal the spatial orientation of the GWs with respect to the source. The relevance of the results for different types of measurements as well as its applicability to model data is discussed.

scholarly journals Unicellular Eukaryote as a Bio-cellular Model for Studying Effect Benzimidazole: Ultrastructural Analysis

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Karlen O Hovnanyan
Keyword(s):  
Mechanism Of Action ◽  
Wide Spectrum ◽  
Biological Effects ◽  
Unicellular Eukaryote ◽  
Electron Microscopic ◽  
Cystic Form ◽  
Ultrastructural Characterization ◽  
Wide Range ◽  
First Time ◽  
Derivatives Of

The search for new derivatives of benzoimidazole with an active center that have a wide range of biological effects (antifungal, antiflammatory, antibacterial, antiviral, antitumor, antidiabetic, etc.) is the subject of modern pharmaceutical science. To determine the mechanism of action of benzoimidazole, a search is underway for more. We have previously carried out the Ultrastructural characterization of various prokaryotes and protists, as well as the mechanism of action of antibiotics and chemical preparations on them. From a series of heterocyclic drugs, a drug with a wide spectrum of action was chosen as derivatives of benzimidazole and a model of a free-living unicellular eukaryote Endameba moshkovskii with a vegetative and cystic form. The purpose of this work is the nature of the action of drugs of the benzimidazole series and in the ultrastructural visualization of the mechanism of action of benzimidazole using electron microscopic and electron-cytochemical methods on the model of polyxenic cultures of unicellular eukaryotes Entamoeba moshkovskii. We have established for the first time the excising effect of benzimidazole and the functional-ultrastructural mechanism of the action of benzimidazole on entameoba cells. As a result, the ultrastructural and functional morphology of benzimidazole action in the process of excysting entamoeba was established.

Sign in / Sign up

Export Citation Format

Share Document