UV-promoted radical formation, and near-IR-induced and spontaneous conformational isomerization in monomeric 9-methylguanine isolated in low-temperature Ar matrices

2019 ◽  
Vol 21 (41) ◽  
pp. 22857-22868
Author(s):  
Maciej J. Nowak ◽  
Igor Reva ◽  
A. J. Lopes Jesus ◽  
Leszek Lapinski ◽  
Rui Fausto
Keyword(s):  
Low Temperature ◽  
The Other ◽  
Radical Formation ◽  
Conformational Isomerization ◽  
Near Ir ◽  
Ir Light

An H-atom detaches from UV-excited 9-methylguanine. Excitation with monochromatic near-IR light selectively transforms a chosen amino-hydroxy conformer (AH1 or AH2) into the other. The AH2 form spontaneously converts, via H-atom tunneling, into AH1.

Lysosome Specific Platinum(II) Catecholates with Photoactive BODIPY for Imaging and Photodynamic Therapy in Near‐IR Light

2021 ◽  
Vol 2021 (9) ◽  
pp. 831-839
Author(s):  
Vanitha Ramu ◽  
Paramita Kundu ◽  
Aarti Upadhyay ◽  
Paturu Kondaiah ◽  
Akhil R. Chakravarty
Keyword(s):  
Photodynamic Therapy ◽  
Near Ir ◽  
Ir Light

scholarly journals The Highly Uniform Photoresponsivity from Visible to Near IR Light in Sb2Te3 Flakes

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1535
Author(s):  
Shiu-Ming Huang ◽  
Jai-Lung Hung ◽  
Mitch Chou ◽  
Chi-Yang Chen ◽  
Fang-Chen Liu ◽  
...  
Keyword(s):  
Band Structure ◽  
Energy Difference ◽  
Experimental Result ◽  
Light Illumination ◽  
Near Ir ◽  
State Band ◽  
Valence Bands ◽  
Low Dimensional ◽  
Low Dimensional Materials ◽  
Ir Light

Broadband photosensors have been widely studied in various kinds of materials. Experimental results have revealed strong wavelength-dependent photoresponses in all previous reports. This limits the potential application of broadband photosensors. Therefore, finding a wavelength-insensitive photosensor is imperative in this application. Photocurrent measurements were performed in Sb2Te3 flakes at various wavelengths ranging from visible to near IR light. The measured photocurrent change was insensitive to wavelengths from 300 to 1000 nm. The observed wavelength response deviation was lower than that in all previous reports. Our results show that the corresponding energies of these photocurrent peaks are consistent with the energy difference of the density of state peaks between conduction and valence bands. This suggests that the observed photocurrent originates from these band structure peak transitions under light illumination. Contrary to the most common explanation that observed broadband photocurrent carrier is mainly from the surface state in low-dimensional materials, our experimental result suggests that bulk state band structure is the main source of the observed photocurrent and dominates the broadband photocurrent.

scholarly journals Hybrid Waveguides: Guided Mid‐IR and Near‐IR Light within a Hybrid Hyperbolic‐Material/Silicon Waveguide Heterostructure (Adv. Mater. 11/2021)

2021 ◽  
Vol 33 (11) ◽  
pp. 2170079
Author(s):  
Mingze He ◽  
Sami I. Halimi ◽  
Thomas G. Folland ◽  
Sai S. Sunku ◽  
Song Liu ◽  
...  
Keyword(s):  
Silicon Waveguide ◽  
Near Ir ◽  
Ir Light

Approaches to Cyclopropa-Fused Quinones. The Synthesis and Photolysis of Some 4,9-Disubstituted 3,3-Dimethyl-3H-benz[f]indazoles

2003 ◽  
Vol 56 (9) ◽  
pp. 903 ◽  
Author(s):  
Gavin E. Collis ◽  
Dieter Wege
Keyword(s):  
Low Temperature ◽  
Functional Group ◽  
Alkoxy Group ◽  
The Other ◽  
Acetoxy Group

Addition of 2-diazopropane to 1,4-naphthoquinone at low temperature, followed by in situ enolization and acetylation or silylation gave 3,3-dimethyl-1H-benz[f]indazol-4,9-diyl diacetate and 3,3-dimethyl-9-(t-butyl-dimethylsilyloxy)-1H-benz[f]indazol-4-ol, respectively. Functional group manipulation of the latter compound provided a number of other 4,9-disubstituted 3,3-dimethyl-3H-benz[f]indazoles. Irradiation of the diacetate led to clean extrusion of nitrogen to give the naphtho[b]cycloproparene and an alkene. Attempts to elaborate the cycloproparene into the derived cyclopropanaphthoquinone were unsuccessful. Of the other 4,9-disubstituted 3,3-dimethyl-3H-benz[f]indazoles examined, only the compound possessing an acetoxy group at C9 was photoactive, and afforded the expected cycloproparene and alkene. Compounds bearing a hydroxy or alkoxy group at C9 were photochemically inert.

Electron drift caused by rf field gradient creates many plasma phenomena: An attempt to distinguish the cause and the effect

2011 ◽  
Vol 78 (2) ◽  
pp. 165-174 ◽  
Author(s):  
C. L. XAPLANTERIS ◽  
E. D. FILIPPAKI ◽  
I. S. MISTAKIDIS ◽  
L. C. XAPLANTERIS
Keyword(s):  
Experimental Data ◽  
Steady State ◽  
Low Temperature ◽  
Mathematical Models ◽  
Field Gradient ◽  
Collision Frequency ◽  
The Other ◽  
Frequency Effect ◽  
Electron Drift ◽  
Plasma Parameters

AbstractMany experimental data along with their theoretical interpretations on the rf low-temperature cylindrical plasma have been issued until today. Our Laboratory has contributed to that research by publishing results and interpretative mathematical models. With the present paper, two issues are being examined; firstly, the estimation of electron drift caused by the rf field gradient, which is the initial reason for the plasma behaviour, and secondly, many new experimental results, especially the electron-neutral collision frequency effect on the other plasma parameters and quantities. Up till now, only the plasma steady state was taken into consideration when a theoretical elaboration was carried out, regardless of the cause and the effect. This indicates the plasma's complicated and chaotic configuration and the need to simplify the problem. In the present work, a classification about the causality of the phenomena is attempted; the rf field gradient electron drift is proved to be the initial cause.

scholarly journals XX.—On Dimethyl-Thetine and its Derivatives

1878 ◽  
Vol 28 (2) ◽  
pp. 571-582 ◽  
Author(s):  
Crum Brown ◽  
E. A. Letts
Keyword(s):  
Low Temperature ◽  
The Other ◽  
Similar Relation ◽  
The One ◽  
Elementary Textbooks

The analogies existing between elements belonging to one “family,” such, for instance, as the nitrogen family or the sulphur family, have long been recognised, and are pointed out and insisted upon even in elementary textbooks; but the very important analogies existing between substances of different quantivalence are apt to be forgotten or overlooked. For illustrations of such analogies we may point to boron and silicon, elements closely resembling one another in themselves and also in their compounds,—differing, indeed, in little else but that the one is triad and the other tetrad. A similar relation exists between gold and platinum.The elementary substances, sulphur and phosphorus, have many points of similarity: both fuse at a comparatively low temperature, both are transformed by heat into amorphous insoluble modifications, and both have anomalous vapour densities.

scholarly journals Infestation of froghopper nymphs changes the amounts of total phenolics in sugarcane

2005 ◽  
Vol 62 (6) ◽  
pp. 543-546 ◽  
Author(s):  
Rafael José Navas da Silva ◽  
Eduardo Rossini Guimarães ◽  
José Francisco Garcia ◽  
Paulo Sérgio Machado Botelho ◽  
Maria Inês Tiraboschi Ferro ◽  
...  
Keyword(s):  
Phenolic Compounds ◽  
Low Temperature ◽  
Temperature Variation ◽  
Total Phenolics ◽  
The Other ◽  
Plant Phenolics ◽  
High Moisture ◽  
Randomized Design ◽  
Leaf Tissues ◽  
Completely Randomized Design

The increased rate of sugarcane harvest without previous burn has provided a very favorable environment to the froghopper Mahanarva fimbriolata (Stal, 1854), with high moisture and low temperature variation. Few works have studied the response of sugarcane to this pest, so little is known about resistant cultivars. Plant phenolics are widely studied compounds because of their known antiherbivore effect. This research aims to determine if the attack of M. fimbriolata nymphs stimulates the accumulation of total phenolics in sugarcane. The experiment was carried out in greenhouse and arranged in completely randomized design, in a 3 X 2 X 4 factorial with three replications. Second instar nymphs of M. fimbriolata were infested at the following rates: control, 2-4 and 4-8 nymphs per pot (first-second infestations, respectively). Pots were covered with nylon net and monitored daily to isolate the effect of leaf sucking adults. Leaf and root samples were collected and kept frozen in liquid nitrogen until analyses. Infested plants showed higher levels of phenolics in both root and leaf tissues. In roots, the cultivar SP80-1816 accumulated more phenolic compounds in response to the infestation of M. fimbriolata. On the other hand, higher levels were found in leaves and roots of control plants of SP86-42, which might be an indication of a non-preference mechanism. The increase of total phenolics in sugarcane infested with root-sucking froghopper nymphs does not seem to be useful to detect the resistance to this pest.

scholarly journals THE EFFECT OF RENNIN UPON CASEIN

1927 ◽  
Vol 10 (6) ◽  
pp. 987-1005 ◽  
Author(s):  
Vladimir Pertzoff
Keyword(s):  
Low Temperature ◽  
Free Enzyme ◽  
The Other ◽  
Temperature Coefficients ◽  
Temperature Levels ◽  
Two Temperature

1. The preparation and purification of paracasein was described and certain criteria for the absence of free enzyme provided for. 2. The solubility of purified paracasein in water at low temperature was studied, and found practically identical with the solubility of casein. 3. The capacity of paracasein to bind base was investigated by means of its solubility in NaOH at 5° and at 23° ± 2°C., and found to be distinctly different from that of casein. 4. At these two temperature levels paracasein had a 1.5 greater capacity to bind base than casein. The equivalent combining weights of paracasein and casein were found to stand each to the other, apapproximately, as 2 to 3. 5. This relationship suggested that the temperature coefficients of the solubility of paracasein and casein in NaOH are identical. 6. This evidence indicates that paracasein is a modification of casein, distinguishable by physicochemical means.

scholarly journals Defining the conditional basis of silicon phthalocyanine near-IR ligand exchange

2018 ◽  
Vol 20 (28) ◽  
pp. 19030-19036 ◽  
Author(s):  
Erin D. Anderson ◽  
Stacey Sova ◽  
Joseph Ivanic ◽  
Lisa Kelly ◽  
Martin J. Schnermann
Keyword(s):  
Ligand Exchange ◽  
Radical Anion ◽  
Near Ir ◽  
Silicon Phthalocyanines ◽  
Conditional Basis ◽  
Ir Light ◽  
Silicon Phthalocyanine

The near-IR light induced ligand exchange of silicon phthalocyanines involves a critical radical anion intermediate and is dependent on hypoxia and a reductant.

Energy in Thermal Physics

2021 ◽  
pp. 1-48
Author(s):  
Daniel V. Schroeder
Keyword(s):  
Low Temperature ◽  
Molecular Level ◽  
The Other ◽  
Thermal Physics ◽  
Other Hand ◽  
Energy Flows ◽  
Basic Concepts ◽  
Simple Models

The behavior of energy in bulk-matter systems is subtle. We observe that energy flows spontaneously from high to low temperature; we refer to this flowing energy as heat; and we distinguish heat from work, the transfer of energy through mechanical or other means unrelated to temperature. On the other hand, simple models of gases and solids strongly suggest that at the molecular level all energy is purely mechanical. This introductory chapter surveys these basic concepts of thermal physics, illustrates them with a wide variety of familiar examples, and sets the stage for developing a deeper understanding.

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