The Creation and Annealing Kinetics of Fast Light Induced Defect States created by 1 Sun Illumination in a-Si:H

2005 ◽  
Vol 862 ◽  
Author(s):  
M.L. Albert ◽  
J. Deng ◽  
X. Niu ◽  
J.M. Pearce ◽  
R.W. Collins ◽  
...  
Keyword(s):  
Defect States ◽  
Recombination Rates ◽  
Carrier Generation ◽  
Illumination Time ◽  
Overall Stability ◽  
History Of ◽  
Fast Light ◽  
Kinetics Of ◽  
Dispersive Process

AbstractPreliminary results are presented on the kinetics of fast states at 25°C created by 1 sun illumination in protocrystalline hydrogen diluted a-Si:H films. The results are for the bulk properties of the a-Si:H films which was confirmed by the similarity of results obtained on corresponding intrinsic layers in p-i-n solar cells. It is found that the kinetics exhibit two regimes. The first regime is in the form of a delay before the onset of an A·log(t) time dependence indicative of a dispersive process. Despite the unexpected effect of a dependence of this first regime on the degradation/annealing history of the samples, it was possible to characterize the highly reproducible logarithmic dependences for different illumination times as well as in the presence of different carrier generation/recombination rates. It is found that for the degradation times studied, the annealing kinetics associated with the second regime are independent of the 1 sun illumination time but are dependent on the recombination introduced by illuminations as low as ∼0-5 of 1 sun. These fast states are located close to midgap, similar to the position of dangling bond defects. The results presented raise interesting questions that still need to be answered about the nature and origin of the fast defects in order to assess their contribution to the long term degradation and the overall stability a-Si:H materials.

Infrared Photosensitivity Due to the Yb-Induced Defect States in Pb1−xGexTe Alloys

1999 ◽  
Vol 607 ◽  
Author(s):  
E.P. Skipetrov ◽  
N.A. Chernova ◽  
E.A. Zvereva ◽  
E.I. Slyn'ko
Keyword(s):  
Persistent Photoconductivity ◽  
Helium Temperature ◽  
Defect States ◽  
Galvanomagnetic Properties ◽  
Jahn Teller ◽  
Kinetics Of

AbstractGalvanomagnetic properties and photoconductivity kinetics of Pb1−xGexTe(x≤0.04) alloys doped with Yb have been investigated. The alloys exhibit high infrared photosensitivity at temperature under 40 K; at helium temperature, the effect of persistent photoconductivity has been observed. The photoconductivity kinetics after terminating of infrared illumination consists of a fast and a long-term relaxation regions. We explain the observed effects by a capture of electrons into the Yb-induced states, that are subjected to the Jahn-Teller instability. The parameters of the Jahn-Teller states are estimated.

scholarly journals Kinetics of Archived M184V Mutation in Treatment-Experienced Virally Suppressed HIV-Infected Patients

2021 ◽  
Author(s):  
Romain Palich ◽  
Elisa Teyssou ◽  
Sophie Sayon ◽  
Basma Abdi ◽  
Cathia Soulie ◽  
...  
Keyword(s):  
Detection Threshold ◽  
Factors Associated ◽  
Hiv Rna ◽  
Hiv Dna ◽  
Immunodeficiency Virus ◽  
History Of ◽  
Viral Sequences ◽  
Kinetics Of ◽  
M184v Mutation

Abstract Background We aimed to assess the kinetics of drug-resistant viral variants (DRVs) harboring the M184V mutation in proviral DNA of long-term virally suppressed patients, and factors associated with DRV persistence. Methods Human immunodeficiency virus (HIV) DNA from blood cells stored in 2016 and 2019 was sequenced using Sanger and ultradeep sequencing (SS and UDS; detection threshold 1%) in antiretroviral therapy (ART)-treated patients with HIV RNA < 50 copies/mL for at least 5 years, with past M184V mutation documented in HIV RNA. Results Among 79 patients, by combining SS and UDS, M184V was found to be absent in 26/79 (33%) patients and persistent in 53/79 (67%). M184V-positive patients had a longer history of ART, lower CD4 nadir, and higher pretherapeutic HIV RNA. Among 37 patients with viral sequences assessed by UDS, the proportion of M184V-positive DRVs significantly decreased between 2016 and 2019 (40% vs 14%, P = .005). The persistence of M184V was associated with duration and level of HIV RNA replication under lamivudine/emtricitabine (3TC/FTC; P = .0009 and P = .009, respectively). Conclusions While it decreased over time in HIV DNA, M184V mutation was more frequently persistent in HIV DNA of more treatment-experienced patients with longer past replication under 3TC/FTC.

Comparative Labelling and Biokinetic Studies of 99mTc-EDTA(Sn) and 99mTc-DTPA(Sn)

1977 ◽  
Vol 16 (01) ◽  
pp. 30-35 ◽  
Author(s):  
N. Agha ◽  
R. B. R. Persson
Keyword(s):  
Complex Formation ◽  
Significant Influence ◽  
Room Temperature ◽  
Ph Value ◽  
Maximum Activity ◽  
Reduction Step ◽  
Labelling Yield ◽  
Different Temperatures ◽  
Kinetics Of

SummaryGelchromatography column scanning has been used to study the fractions of 99mTc-pertechnetate, 99mTcchelate and reduced hydrolyzed 99mTc in preparations of 99mTc-EDTA(Sn) and 99mTc-DTPA(Sn). The labelling yield of 99mTc-EDTA(Sn) chelate was as high as 90—95% when 100 μmol EDTA · H4 and 0.5 (Amol SnCl2 was incubated with 10 ml 99mTceluate for 30—60 min at room temperature. The study of the influence of the pH-value on the fraction of 99mTc-EDTA shows that pH 2.8—2.9 gave the best labelling yield. In a comparative study of the labelling kinetics of 99mTc-EDTA(Sn) and 99mTc- DTPA(Sn) at different temperatures (7, 22 and 37°C), no significant influence on the reduction step was found. The rate constant for complex formation, however, increased more rapidly with increased temperature for 99mTc-DTPA(Sn). At room temperature only a few minutes was required to achieve a high labelling yield with 99mTc-DTPA(Sn) whereas about 60 min was required for 99mTc-EDTA(Sn). Comparative biokinetic studies in rabbits showed that the maximum activity in kidneys is achieved after 12 min with 99mTc-EDTA(Sn) but already after 6 min with 99mTc-DTPA(Sn). The long-term disappearance of 99mTc-DTPA(Sn) from the kidneys is about five times faster than that for 99mTc-EDTA(Sn).

Atypical Femoral Fracture in McCune-Albright Syndrome

2020 ◽  
Vol 7 (3) ◽  
pp. 147-152
Author(s):  
Salman Ghaffari ◽  
◽  
Mehran Razavipour ◽  
Parastoo Mohammad Amini ◽  
◽  
...  
Keyword(s):  
Femoral Fracture ◽  
Dynamic Compression ◽  
Plate Fixation ◽  
Medullary Canal ◽  
Mccune Albright Syndrome ◽  
Café Au Lait Spots ◽  
History Of ◽  
Albright Syndrome ◽  
Mccune Albright

McCune-Albright Syndrome (MAS) is characterized by endocrinopathies, café-au-lait spots, and fibrous dysplasia. Bisphosphonates are the most prescribed treatment for reducing the pain but their long-term use has been associated with atypical fractures of cortical bones like femur in patients. We present a 23-year-old girl diagnosed with MAS. She had an atypical mid-shaft left femoral fracture that happened during simple walking. She also had a history of long-term use of alendronate. Because of the narrow medullary canal, we used 14 holes hybrid locking plate for the lateral aspect of the thigh to fix the fracture and 5 holes dynamic compression plate (instead of the intramedullary nail) in the anterior surface to double fix it, reducing the probability of device failure. With double plate fixation and discontinuation of alendronate, the complete union was achieved five months after surgery

European Integration

2020 ◽  
Author(s):  
Johann P. Arnason
Keyword(s):  
European Integration ◽  
Eastern European ◽  
The European Union ◽  
Historical Processes ◽  
History Of ◽  
External Conditions ◽  
Eastern European Countries ◽  
Totalitarian Regimes ◽  
The Eu

Different understandings of European integration, its background and present problems are represented in this book, but they share an emphasis on historical processes, geopolitical dynamics and regional diversity. The introduction surveys approaches to the question of European continuities and discontinuities, before going on to an overview of chapters. The following three contributions deal with long-term perspectives, including the question of Europe as a civilisational entity, the civilisational crisis of the twentieth century, marked by wars and totalitarian regimes, and a comparison of the European Union with the Habsburg Empire, with particular emphasis on similar crisis symptoms. The next three chapters discuss various aspects and contexts of the present crisis. Reflections on the Brexit controversy throw light on a longer history of intra-Union rivalry, enduring disputes and changing external conditions. An analysis of efforts to strengthen the EU’s legal and constitutional framework, and of resistances to them, highlights the unfinished agenda of integration. A closer look at the much-disputed Islamic presence in Europe suggests that an interdependent radicalization of Islamism and the European extreme right is a major factor in current political developments. Three concluding chapters adopt specific regional perspectives. Central and Eastern European countries, especially Poland, are following a path that leads to conflicts with dominant orientations of the EU, but this also raises questions about Europe’s future. The record of Scandinavian policies in relation to Europe exemplifies more general problems faced by peripheral regions. Finally, growing dissonances and divergences within the EU may strengthen the case for Eurasian perspectives.

The natural history of pituitary apoplexy: long term follow-up study

2019 ◽  
Author(s):  
Ayesha Shaikh ◽  
Natasha Shrikrishnapalasuriyar ◽  
Giselle Sharaf ◽  
David Price ◽  
Maneesh Udiawar ◽  
...  
Keyword(s):  
Natural History ◽  
Pituitary Apoplexy ◽  
Follow Up Study ◽  
Long Term Follow Up ◽  
History Of

1386-P: Long-Term Weight Change after Pregnancy and Type 2 Diabetes Risk in Women with a History of Gestational Diabetes

Diabetes ◽  
2020 ◽  
Vol 69 (Supplement 1) ◽  
pp. 1386-P
Author(s):  
SYLVIA E. BADON ◽  
FEI XU ◽  
CHARLES QUESENBERRY ◽  
ASSIAMIRA FERRARA ◽  
MONIQUE M. HEDDERSON
Keyword(s):  
Type 2 Diabetes ◽  
Gestational Diabetes ◽  
Weight Change ◽  
Diabetes Risk ◽  
History Of

Update on the Boundaries of the Curly Birch Range

2020 ◽  
pp. 9-21
Author(s):  
L.V. Vetchinnikova ◽  
◽  
A.F. Titov ◽  
◽  
Keyword(s):  
Population Size ◽  
Natural Populations ◽  
Forest Tree ◽  
Published Data ◽  
Population Approach ◽  
Key Factors ◽  
History Of ◽  
Individual Trees ◽  
Karelian Birch

The article reports on the application of the best known principles for mapping natural populations of curly (Karelian) birch Betula pendula Roth var. carelica (Mercklin) Hämet-Ahti – one of the most appealing representatives of the forest tree flora. Relying on the synthesis and analysis of the published data amassed over nearly 100 years and the data from own full-scale studies done in the past few decades almost throughout the area where curly birch has grown naturally, it is concluded that its range outlined in the middle of the 20th century and since then hardly revised is outdated. The key factors and reasons necessitating its revision are specified. Herewith it is suggested that the range is delineated using the population approach, and the key element will be the critical population size below which the population is no longer viable in the long term. This approach implies that the boundaries of the taxon range depend on the boundaries of local populations (rather than the locations of individual trees or small clumps of trees), the size of which should not be lower than the critical value, which is supposed to be around 100–500 trees for curly birch. A schematic map of the curly birch range delineated using this approach is provided. We specially address the problem of determining the minimum population size to secure genetic diversity maintenance. The advantages of the population approach to delineating the distribution range of curly birch with regard to its biological features are highlighted. The authors argue that it enables a more accurate delineation of the range; shows the natural evolutionary history of the taxon (although it is not yet officially recognized as a species) and its range; can be relatively easily updated (e.g. depending on the scope of reintroduction); should be taken into account when working on the strategy of conservation and other actions designed to maintain and regenerate this unique representative of the forest tree flora.

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