Synthesis of an azadioxa-planar triphenylborane and investigation of its structural and photophysical properties

2021 ◽  
Author(s):  
Y. Kitamoto ◽  
K. Oda ◽  
K. Ogino ◽  
K. Hiyama ◽  
H. Kita ◽  
...  
Keyword(s):  
Photophysical Properties ◽  
Critical Role ◽  
Molecular Properties ◽  
Bridging Groups ◽  
First Time

An azadioxa-planar triphenylborane was synthesized for the first time and it was found that bridging groups have a critical role in changing its molecular properties.

Non-Plasmonic SERS with Silicon: Is It Really Safe? New Insights into Opto-Thermics of Core/Shell Microbeads

2018 ◽  
Author(s):  
Nicolò Bontempi ◽  
Irene Vassalini ◽  
Stefano Danesi ◽  
Matteo Ferroni ◽  
Paolo Colombi ◽  
...  
Keyword(s):  
Critical Role ◽  
Raman Laser ◽  
Core Shell ◽  
Thermal Coupling ◽  
Melting Points ◽  
Experimental Proof ◽  
Weakly Coupled ◽  
Light Management ◽  
Laser Sources ◽  
First Time

<p>Here we investigate for the first time the opto-thermal behavior of SiO<sub>2</sub>/Si core/shell microbeads (Si-rex) irradiated with three common Raman laser sources (lambda=532, 633, 785 nm) under real working conditions. We obtained an experimental proof of the critical role played by bead size and aggregation in heat and light management, demonstrating that in the case of strong opto-thermal coupling the temperature can exceed that of the melting points of both core and shell components. In addition, we also show that weakly coupled beads can be utilized as stable substrates for plasmon-free SERS experiments.</p>

scholarly journals Prediction of IL4 Inducing Peptides

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Sandeep Kumar Dhanda ◽  
Sudheer Gupta ◽  
Pooja Vir ◽  
G. P. S. Raghava
Keyword(s):  
Mhc Class Ii ◽  
Critical Role ◽  
Interleukin 4 ◽  
Th2 Response ◽  
Data Set ◽  
T Helper 2 ◽  
Cell Responses ◽  
Antibody Class ◽  
First Time ◽  
Motif Information

The secretion of Interleukin-4 (IL4) is the characteristic of T-helper 2 responses. IL4 is a cytokine produced by CD4+ T cells in response to helminthes and other extracellular parasites. It has a critical role in guiding antibody class switching, hematopoiesis and inflammation, and the development of appropriate effector T-cell responses. In this study, it is the first time an attempt has been made to understand whether it is possible to predict IL4 inducing peptides. The data set used in this study comprises 904 experimentally validated IL4 inducing and 742 noninducing MHC class II binders. Our analysis revealed that certain types of residues are preferred at certain positions in IL4 inducing peptides. It was also observed that IL4 inducing and noninducing epitopes differ in compositional and motif pattern. Based on our analysis we developed classification models where the hybrid method of amino acid pairs and motif information performed the best with maximum accuracy of 75.76% and MCC of 0.51. These results indicate that it is possible to predict IL4 inducing peptides with reasonable precession. These models would be useful in designing the peptides that may induce desired Th2 response.

Updating the knowledge of the flower flies (Diptera: Syrphidae) from Chile: Illustrated catalog, extinction risk and biological notes

Zootaxa ◽  
2021 ◽  
Vol 4959 (1) ◽  
pp. 1-178
Author(s):  
RODRIGO M. BARAHONA-SEGOVIA ◽  
PAMELA RIERA ◽  
LAURA PAÑINAO-MONSÁLVEZ ◽  
VICENTE VALDÉS GUZMÁN ◽  
PATRICIA HENRÍQUEZ-PISKULICH
Keyword(s):  
Extinction Risk ◽  
Critical Role ◽  
Floral Biology ◽  
Iucn Red List ◽  
Decomposition Of Organic Matter ◽  
Management Plans ◽  
Flower Flies ◽  
Iucn Red List Criteria ◽  
Definition Of ◽  
First Time

Syrphidae, more commonly known as flower flies, are considered one of the most important Diptera families worldwide because of their critical role in pollination, biological control and decomposition of organic matter. The study of these flies in Chile has stagnated due to a lack of local experts as well as the absence of an updated catalog of species. This study is an attempt to remedy the latter of these issues by providing an illustrated and updated catalog to the Syrphidae of Chile. Species are presented under currently accepted names, with synonyms and previous combinations listed and original references. Type localities, world and Chilean distribution by geopolitical Chilean regions, taxonomic and biological notes, a complete record of bibliographic references and extinction risk under IUCN Red List criteria are provided. This catalog recognizes 132 species of Syrphidae, belonging to four subfamilies (Eristalinae, Microdontinae, Pipizinae and Syrphinae), 13 tribes and 47 genera. A total of 46 species (34.84 %) is restricted to the geopolitical territory of Chile. Eight species are considered exotic, one is considered incertae sedis and three are based on doubtful records. Seventeen species of 10 different genera (Copestylum Macquart, 1846; Dolichogyna Macquart, 1842; Eosalpingogaster Hull, 1949b; Eupeodes Osten Sacken, 1877; Meromacrus Rondani, 1848; Palpada Macquart, 1834; Paragus Latreille, 1804; Sphiximorpha Rondani, 1850; Sterphus Philippi, 1865 and Toxomerus Macquart, 1855) are reported from Chile for the first time. A total of 44 species (33.33 %) reported from Chile are directly threatened by human activities such as agriculture, forestry, mining and/or urbanization and indirectly by climate change. The gaps found in the geographic distribution of Chilean flower fly species and what it means for its use by disciplines such as ecology, floral biology and agronomy, are discussed. In addition, the use of this illustrated catalog for biological conservation, the potential definition of priority areas and ecosystem management plans based on this group of Diptera are also discussed. 

scholarly journals The nanoscaled metal-organic framework ICR-2 as a carrier of porphyrins for photodynamic therapy

2018 ◽  
Vol 9 ◽  
pp. 2960-2967 ◽  
Author(s):  
Jan Hynek ◽  
Sebastian Jurík ◽  
Martina Koncošová ◽  
Jaroslav Zelenka ◽  
Ivana Křížová ◽  
...  
Keyword(s):  
Inorganic Chemistry ◽  
Photodynamic Therapy ◽  
Photophysical Properties ◽  
Metal Organic Framework ◽  
Metal Organic Frameworks ◽  
Biological Applications ◽  
Nanoparticle Surface ◽  
Metal Organic ◽  
Unsaturated Metal Sites ◽  
First Time

Nanosized porphyrin-containing metal-organic frameworks (MOFs) attract considerable attention as solid-state photosensitizers for biological applications. In this study, we have for the first time synthesised and characterised phosphinate-based MOF nanoparticles, nanoICR-2 (Inorganic Chemistry Rez). We demonstrate that nanoICR-2 can be decorated with anionic 5,10,15,20-tetrakis(4-R-phosphinatophenyl)porphyrins (R = methyl, isopropyl, phenyl) by utilizing unsaturated metal sites on the nanoparticle surface. The use of these porphyrins allows for superior loading of the nanoparticles when compared with commonly used 5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin. The nanoICR-2/porphyrin composites retain part of the free porphyrins photophysical properties, while the photodynamic efficacy is strongly affected by the R substituent at the porphyrin phosphinate groups. Thus, phosphinatophenylporphyrin with phenyl substituents has the strongest photodynamic efficacy due to the most efficient cellular uptake.

scholarly journals Obesity Accelerates Age-Associated Defects in Human B Cells Through a Metabolic Reprogramming Induced by the Fatty Acid Palmitate

2022 ◽  
Vol 2 ◽  
Author(s):  
Daniela Frasca ◽  
Maria Romero ◽  
Denisse Garcia ◽  
Alain Diaz ◽  
Bonnie B. Blomberg
Keyword(s):  
Fatty Acid ◽  
B Cells ◽  
Critical Role ◽  
Metabolic Reprogramming ◽  
Autoimmune Antibodies ◽  
Human B Cells ◽  
Initial Hypothesis ◽  
First Time ◽  
Culture Supernatants

We have measured the secretion of autoimmune antibodies in plasma samples and in culture supernatants of blood-derived B cells from four groups of individuals: young lean (YL), elderly lean (EL), young obese (YO) and elderly obese (EO). We found secretion comparable in YO and EL individuals, suggesting that obesity accelerates age-associated defects in circulating B cells. To define at least one possible molecular pathway involved, we used an in vitro model in which B cells from YL and EL individuals have been stimulated with the Fatty Acid (FA) palmitate, the most common saturated FA in the human body. The rationale to use palmitate is that there is a chronic increase in circulating levels of palmitate, due to increased spontaneous lipolysis occurring during aging and obesity, and this may induce autoimmune B cells. Results herein show that in vitro incubation of B cells from YL and EL individuals with the FA palmitate induces mRNA expression of T-bet, the transcription factor for autoimmune antibodies, as well as secretion of autoimmune IgG antibodies, with B cells from YL individuals looking similar to B cells from EL individuals, confirming our initial hypothesis. The generation of autoimmune B cells in the presence of the FA palmitate was found to be associated with a metabolic reprogramming of B cells from both YL and EL individuals. These results altogether show the critical role of the FA palmitate in inducing human B cell immunosenescence and show for the first time the importance of metabolic pathways in this process.

scholarly journals The upper atmospheres of Uranus and Neptune

2020 ◽  
Vol 378 (2187) ◽  
pp. 20190478 ◽  
Author(s):  
Henrik Melin
Keyword(s):  
Magnetic Field ◽  
Joule Heating ◽  
Critical Role ◽  
Upper Atmosphere ◽  
Heating Rates ◽  
James Webb Space Telescope ◽  
Vertical Distributions ◽  
Auroral Current ◽  
First Time ◽  
The Magnetic Field

We review the current understanding of the upper atmospheres of Uranus and Neptune, and explore the upcoming opportunities available to study these exciting planets. The ice giants are the least understood planets in the solar system, having been only visited by a single spacecraft, in 1986 and 1989, respectively. The upper atmosphere plays a critical role in connecting the atmosphere to the forces and processes contained within the magnetic field. For example, auroral current systems can drive charged particles into the atmosphere, heating it by way of Joule heating. Ground-based observations of H 3 + provides a powerful remote diagnostic of the physical properties and processes that occur within the upper atmosphere, and a rich dataset exists for Uranus. These observations span almost three decades and have revealed that the upper atmosphere has continuously cooled between 1992 and 2018 at about 8 K/year, from approximately 750 K to approximately 500 K. The reason for this trend remain unclear, but could be related to seasonally driven changes in the Joule heating rates due to the tilted and offset magnetic field, or could be related to changing vertical distributions of hydrocarbons. H 3 + has not yet been detected at Neptune, but this discovery provides low-hanging fruit for upcoming facilities such as the James Webb Space Telescope and the next generation of 30 m telescopes. Detecting H 3 + at Neptune would enable the characterization of its upper atmosphere for the first time since 1989. To fully understand the ice giants, we need dedicated orbital missions, in the same way the Cassini spacecraft explored Saturn. Only by combining in situ observations of the magnetic field with in-orbit remote sensing can we get the complete picture of how energy moves between the atmosphere and the magnetic field. This article is part of a discussion meeting issue ‘Future exploration of ice giant systems’.

scholarly journals Cloud-top entrainment instability?

2010 ◽  
Vol 660 ◽  
pp. 1-4 ◽  
Author(s):  
B. STEVENS
Keyword(s):  
Numerical Simulations ◽  
Critical Role ◽  
Direct Numerical Simulations ◽  
Spatial Extent ◽  
High Fidelity ◽  
Mixing Processes ◽  
Molecular Mixing ◽  
First Time ◽  
Cloud Regimes

Mixing processes at cloud boundaries are thought to play a critical role in determining cloud lifetime, spatial extent and cloud microphysical structure. High-fidelity direct numerical simulations by Mellado (J. Fluid Mech., 2010, this issue, vol. 660, pp. 5–36) show, for the first time, the character and potency of a curious instability that may arise as a result of molecular mixing processes at cloud boundaries, an instability which until now has been thought by many to control the distribution of climatologically important cloud regimes.

scholarly journals Cyclic AMP-dependent Protein Lysine Acylation in Mycobacteria Regulates Fatty Acid and Propionate Metabolism

2013 ◽  
Vol 288 (20) ◽  
pp. 14114-14124 ◽  
Author(s):  
Subhalaxmi Nambi ◽  
Kallol Gupta ◽  
Moitrayee Bhattacharyya ◽  
Parvathy Ramakrishnan ◽  
Vaishnavi Ravikumar ◽  
...  
Keyword(s):  
Critical Role ◽  
Fatty Acyl ◽  
Intracellular Camp ◽  
Dependent Manner ◽  
Multiple Substrates ◽  
Propionate Metabolism ◽  
Lysine Residues ◽  
Dependent Protein ◽  
First Time ◽  
Camp Levels

Acetylation of lysine residues is a posttranslational modification that is used by both eukaryotes and prokaryotes to regulate a variety of biological processes. Here we identify multiple substrates for the cAMP-dependent protein lysine acetyltransferase from Mycobacterium tuberculosis (KATmt). We demonstrate that a catalytically important lysine residue in a number of FadD (fatty acyl CoA synthetase) enzymes is acetylated by KATmt in a cAMP-dependent manner and that acetylation inhibits the activity of FadD enzymes. A sirtuin-like enzyme can deacetylate multiple FadDs, thus completing the regulatory cycle. Using a strain deleted for the KATmt ortholog in Mycobacterium bovis Bacillus Calmette-Guérin (BCG), we show for the first time that acetylation is dependent on intracellular cAMP levels. KATmt can utilize propionyl CoA as a substrate and, therefore, plays a critical role in alleviating propionyl CoA toxicity in mycobacteria by inactivating acyl CoA synthetase (ACS). The precision by which mycobacteria can regulate the metabolism of fatty acids in a cAMP-dependent manner appears to be unparalleled in other biological organisms and is ideally suited to adapt to the complex environment that pathogenic mycobacteria experience in the host.

scholarly journals Comparative Assessment of Affinity-Based Techniques for Oriented Antibody Immobilization towards Immunosensor Performance Optimization

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
George Tsekenis ◽  
Marianneza Chatzipetrou ◽  
Maria Massaouti ◽  
Ioanna Zergioti
Keyword(s):  
Performance Optimization ◽  
Surface Density ◽  
Critical Role ◽  
Protein A ◽  
Antigen Binding ◽  
Antibody Immobilization ◽  
Functionalized Surfaces ◽  
Antigen System ◽  
Complex Engineering ◽  
First Time

Immunosensor sensitivity and stability depend on a number of parameters such as the orientation, the surface density, and the antigen-binding efficiency of antibodies following their immobilization onto functionalized surfaces. A number of techniques have been developed to improve the performance of an immunosensor that targets one or both of the parameters mentioned above. Herein, two widely employed techniques are compared for the first time, which do not require any complex engineering of neither the antibodies nor the surfaces onto which the former get immobilized. To optimize the different surface functionalization protocols and compare their efficiency, a model antibody-antigen system was employed that resembles the complex matrices immunosensors are frequently faced with in real conditions. The obtained results reveal that protein A/G is much more efficient in increasing antibody loading onto the surfaces in comparison to boronate ester chemistry. Despite the fact, therefore, that both contribute towards the orientation-specific immobilization of antibodies and hence enhance their antigen-binding efficiency, it is the increased antibody surface density attained with the use of protein A/G that plays a critical role in achieving maximal antigen recognition.

scholarly journals Dissecting pigment architecture of individual photosynthetic antenna complexes in solution

2015 ◽  
Vol 112 (45) ◽  
pp. 13880-13885 ◽  
Author(s):  
Quan Wang ◽  
W. E. Moerner
Keyword(s):  
Single Molecule ◽  
Light Harvesting ◽  
Fluorescent Proteins ◽  
Protein Complexes ◽  
Photophysical Properties ◽  
Critical Role ◽  
Photosynthetic Pigment ◽  
Emergent Properties ◽  
Aqueous Environment ◽  
Harvesting Systems

Oligomerization plays a critical role in shaping the light-harvesting properties of many photosynthetic pigment−protein complexes, but a detailed understanding of this process at the level of individual pigments is still lacking. To study the effects of oligomerization, we designed a single-molecule approach to probe the photophysical properties of individual pigment sites as a function of protein assembly state. Our method, based on the principles of anti-Brownian electrokinetic trapping of single fluorescent proteins, step-wise photobleaching, and multiparameter spectroscopy, allows pigment-specific spectroscopic information on single multipigment antennae to be recorded in a nonperturbative aqueous environment with unprecedented detail. We focus on the monomer-to-trimer transformation of allophycocyanin (APC), an important antenna protein in cyanobacteria. Our data reveal that the two chemically identical pigments in APC have different roles. One (α) is the functional pigment that red-shifts its spectral properties upon trimer formation, whereas the other (β) is a “protective” pigment that persistently quenches the excited state of α in the prefunctional, monomer state of the protein. These results show how subtleties in pigment organization give rise to functionally important aspects of energy transfer and photoprotection in antenna complexes. The method developed here should find immediate application in understanding the emergent properties of other natural and artificial light-harvesting systems.

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