Investigation of high concentration effects of Sb and P in silicon by combination of SIMS and TEM

1989 ◽  
Vol 333 (3) ◽  
pp. 191-202 ◽  
Author(s):  
G. Stingeder ◽  
P. Pongratz ◽  
W. Kuhnert ◽  
T. Brabec
Keyword(s):  
High Concentration ◽  
Concentration Effects

Ultra-high concentration effects in multi-junction solar cells

2005 ◽  
Author(s):  
Eugene A. Katz ◽  
Jeffrey M. Gordon ◽  
Wondesen Tassew ◽  
Daniel Feuermann
Keyword(s):  
Solar Cells ◽  
High Concentration ◽  
Concentration Effects

scholarly journals High-Dose Benzodiazepines Positively Modulate GABAA Receptors via a Flumazenil-Insensitive Mechanism

2021 ◽  
Vol 23 (1) ◽  
pp. 42
Author(s):  
Na Wang ◽  
Jingjing Lian ◽  
Yanqing Cao ◽  
Alai Muheyati ◽  
Shanshan Yuan ◽  
...  
Keyword(s):  
Gabaa Receptors ◽  
High Dose ◽  
High Concentration ◽  
Concentration Effects ◽  
In Vivo Evaluation ◽  
Chemical Structures ◽  
Loss Of Righting Reflex ◽  
High Concentrations

Benzodiazepines (BZDs) produce versatile pharmacological actions through positive modulation of GABAA receptors (GABAARs). A previous study has demonstrated that high concentrations of diazepam potentiate GABA currents on the α1β2γ2 and α1β2 GABAARs in a flumazenil-insensitive manner. In this study, the high-concentration effects of BZDs and their sensitivity to flumazenil were determined on synaptic (α1β2γ2, α2β2γ2, α5β2γ2) and extra-synaptic (α4β2δ) GABAARs using the voltage-clamp electrophysiology technique. The in vivo evaluation of flumazenil-insensitive BZD effects was conducted in mice via the loss of righting reflex (LORR) test. Diazepam induced biphasic potentiation on the α1β2γ2, α2β2γ2 and α5β2γ2 GABAARs, but did not affect the α4β2δ receptor. In contrast to the nanomolar component of potentiation, the second potentiation elicited by micromolar diazepam was insensitive to flumazenil. Midazolam, clonazepam, and lorazepam at 200 µM exhibited similar flumazenil-insensitive effects on the α1β2γ2, α2β2γ2 and α5β2γ2 receptors, whereas the potentiation induced by 200 µM zolpidem or triazolam was abolished by flumazenil. Both the GABAAR antagonist pentylenetetrazol and Fa173, a proposed transmembrane site antagonist, abolished the potentiation induced by 200 µM diazepam. Consistent with the in vitro results, flumazenil antagonized the zolpidem-induced LORR, but not that induced by diazepam or midazolam. Pentylenetetrazol and Fa173 antagonized the diazepam-induced LORR. These findings support the existence of non-classical BZD binding sites on certain GABAAR subtypes and indicate that the flumazenil-insensitive effects depend on the chemical structures of BZD ligands.

Mixture and Concentration Effects on Odorant Receptor Response Patterns In Vivo

2020 ◽  
Vol 45 (6) ◽  
pp. 429-438 ◽  
Author(s):  
Timothy S McClintock ◽  
Qiang Wang ◽  
Tomoko Sengoku ◽  
William B Titlow ◽  
Patrick Breheny
Keyword(s):  
Odorant Receptor ◽  
Single Species ◽  
Odorant Receptors ◽  
Response Patterns ◽  
High Concentration ◽  
Concentration Effects ◽  
Volatile Chemicals ◽  
Receptor Response ◽  
Mixture Suppression

Abstract Natural odors are mixtures of volatile chemicals (odorants). Odors are encoded as responses of distinct subsets of the hundreds of odorant receptors and trace amine-associated receptors expressed monogenically by olfactory sensory neurons. This is an elegantly simple mechanism for differentially encoding odors but it is susceptible to complex dose–response relationships and interactions between odorants at receptors, which may help explain olfactory phenomena, such as mixture suppression, synthetic versus elemental odor processing, and poorly predictable perceptual outcomes of new odor mixtures. In this study, in vivo tests in freely behaving mice confirm evidence of a characteristic receptor response pattern consisting of a few receptors with strong responses and a greater number of weakly responding receptors. Odorant receptors responsive to an odor are often unrelated and widely divergent in sequence, even when the odor consists of a single species of odorant. Odorant receptor response patterns to a citrus odor broaden with concentration. Some highly sensitive receptors respond only to a low concentration but others respond in proportion to concentration, a feature that may be critical for concentration-invariant perception. Other tests find evidence of interactions between odorants in vivo. All of the odorant receptor responses to a moderate concentration of the fecal malodor indole are suppressed by a high concentration of the floral odorant, α-ionone. Such suppressive effects are consistent with prior evidence that odorant interactions at individual odorant receptors are common.

scholarly journals Flumazenil-Insensitive Benzodiazepine Effects in Recombinant αβ and Neuronal GABAA Receptors

2020 ◽  
Vol 10 (3) ◽  
pp. 150
Author(s):  
Jing-Jing Lian ◽  
Yan-Qing Cao ◽  
Yu-Lei Li ◽  
Gang Yu ◽  
Rui-Bin Su
Keyword(s):  
Gabaa Receptors ◽  
Binding Sites ◽  
Cortical Neurons ◽  
Drug Binding ◽  
Receptor Subtypes ◽  
Gamma Aminobutyric Acid ◽  
High Concentration ◽  
Concentration Effects ◽  
Whole Cell Patch Clamp ◽  
Patch Clamp Electrophysiology

Gamma-aminobutyric acid, type A (GABAA) receptors are complex heterogeneous pentamers with various drug binding sites. Several lines of evidence suggest that benzodiazepines modulate certain GABAA receptors in a flumazenil-insensitive manner, possibly via binding sites other than the classical ones. However, GABAA receptor subtypes that contain non-classical benzodiazepine binding sites are not systemically studied. The present study investigated the high-concentration effects of three benzodiazepines and their sensitivity to flumazenil on different recombinant (α1β2, α2β2, α3β2, α4β2, α5β2 and α1β3) and native neuronal GABAA receptors using the whole-cell patch-clamp electrophysiology technique. The classical benzodiazepine diazepam (200 μmol/L) and midazolam (200 μmol/L) produced flumazenil-insensitive effects on α1β2 receptor, whereas the imidazopyridine zolpidem failed to modulate the receptor. Flumazenil-insensitive effects of diazepam were also observed on the α2β2, α3β2 and α5β2, but not α4β2 receptors. Unlike β2-containing receptors, the α1β3 receptor was insensitive to diazepam. Moreover, the diazepam (200 μmol/L) effects on some cortical neurons could not be fully antagonized by flumazenil (200 μmol/L). These findings suggested that the non-classical (flumazenil-insensitive) benzodiazepine effects depended on certain receptor subtypes and benzodiazepine structures and may be important for designing of subtype- or binding site- specific drugs.

scholarly journals Analysis of the size dependence of macromolecular crowding shows that smaller is better

2015 ◽  
Vol 112 (26) ◽  
pp. 7990-7995 ◽  
Author(s):  
Kim A. Sharp
Keyword(s):  
Small Molecules ◽  
Size Dependence ◽  
Reaction Rates ◽  
Medium Size ◽  
In Vitro Experiments ◽  
High Concentration ◽  
Concentration Effects ◽  
Large Molecules

The aqueous milieu inside cells contains as much as 30–40% dissolved protein and RNA by volume. This large concentration of macromolecules is expected to cause significant deviations from solution ideality. In vivo biochemical reaction rates and equilibria might differ significantly from those measured in the majority of in vitro experiments that are performed at much lower macromolecule concentrations. Consequently crowding, a nonspecific phenomenon believed to arise from the large excluded volume of these macromolecules, has been studied extensively by experimental and theoretical methods. However, the relevant theory has not been applied consistently. When the steric effects of macromolecular crowders and small molecules like water and ions are treated on an equal footing, the effect of the macromolecules is opposite to that commonly believed. Large molecules are less effective at crowding than water and ions. There is also a surprisingly weak dependence on crowder size. Molecules of medium size, ∼5 Å radius, have the same effect as much larger macromolecules like proteins and RNA. These results require a reassessment of observed high-concentration effects and of strategies to mimic in vivo conditions with in vitro experiments.

High concentration effects of ion implanted boron in silicon

1980 ◽  
Vol 22 (1) ◽  
pp. 35-38 ◽  
Author(s):  
H. Ryssel ◽  
K. Müller ◽  
K. Haberger ◽  
R. Henkelmann ◽  
F. Jahnel
Keyword(s):  
High Concentration ◽  
Concentration Effects ◽  
Ion Implanted
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