1,274 research outputs found
Charge pair dissociation and recombination dynamics in a P3HT–PC60BM bulk heterojunction
The authors thank the EPSRC, SUPA, the Condensed Matter Doctoral Training Centre and the European Union Seventh Framework programme (grant agreement 321305) for financial support.The mechanism by which Coulombically bound charge pairs dissociate into free carriers in photovoltaic donor–acceptor blends is of great interest. Here, we use polarization-sensitive transient absorption (TA) to study the diffusion of photogenerated holes in a polythiophene (P3HT)–fullerene (PC60BM) blend. We observe an initial anisotropy value of 0.4 for the absorption of photogenerated holes, indicating that holes generated on a 100 fs time scale are localized on the same polymer chain as their precursor excitons. Depolarization dynamics indicate fast initial hole motion on a 0.3 ps time scale and slower migration up to 100 ps. Charge pair recombination is found to occur on a much longer time scale of 10–1000 ns via a purely bimolecular process independent of excess energy. Our results show that nearly all charge pairs get separated by at least 7 nm in the absence of an external field and indicate that high charge mobility is crucial for charge separation.PostprintPeer reviewe
Long-Term Preservation of Cones and Improvement in Visual Function Following Gene Therapy in a Mouse Model of Leber Congenital Amaurosis Caused by Guanylate Cyclase-1 Deficiency
Leber congenital amaurosis (LCA) is a severe retinal dystrophy manifesting from early infancy as poor vision or blindness. Loss-of-function mutations in GUCY2D cause LCA1 and are one of the most common causes of LCA, accounting for 20% of all cases. Human GUCY2D and mouse Gucy2e genes encode guanylate cyclase-1 (GC), which is responsible for restoring the dark state in photoreceptors after light exposure. The Glicy2e(-/-) mouse shows partially diminished rod function, but an absence of cone function before degeneration. Although the cones appear morphologically normal, they exhibit mislocalization of proteins involved in phototransduction. In this study we tested the efficacy of an rAAV2/8 vector containing the human rhodopsin kinase promoter and the human GUCY2D gene. Following subretinal delivery of the vector in Glicy2e(-/-) mice, GC1 protein was detected in the rod and cone outer segments, and in transduced areas of retina cone transducin was appropriately localized to cone outer segments. Moreover, we observed a dose-dependent restoration of rod and cone function and an improvement in visual behavior of the treated mice. Most importantly, cone preservation was observed in transduced areas up to 6 months post injection. To date, this is the most effective rescue of the Glicy2e(-/-) mouse model of LCA and we propose that a vector, similar to the one used in this study, could be suitable for use in a clinical trial of gene therapy for LCA1
Law, politics and the governance of English and Scottish joint-stock companies 1600-1850
This article examines the impact of law on corporate governance by means of a case study of joint-stock enterprise in England and Scotland before 1850. Based on a dataset of over 450 company constitutions together with qualitative information on governance practice, it finds little evidence to support the hypothesis that common-law regimes such as England were more supportive of economic growth than civil-law jurisdictions such as Scotland: indeed, levels of shareholder protection were slightly stronger in the civil-law zone. Other factors, such as local political institutions, played a bigger role in shaping organisational forms and business practice
A large population of strongly lensed faint submillimetre galaxies in future dark energy surveys inferred from JWST imaging
Bright galaxies at sub-millimetre wavelengths from Herschel are now well
known to be predominantly strongly gravitationally lensed. The same models that
successfully predicted this strongly lensed population also predict about one
percent of faint m-selected galaxies from deep JCMT surveys will also
be strongly lensed. Follow-up ALMA campaigns have so far found one potential
lens candidate, but without clear compelling evidence e.g. from lensing arcs.
Here we report the discovery of a compelling gravitational lens system
confirming the lensing population predictions, with a
submm source lensed by a foreground galaxy within the COSMOS
field, identified through public JWST imaging of a m source in the
SCUBA-2 Ultra Deep Imaging EAO Survey (STUDIES) catalogue. These systems will
typically be well within the detectable range of future wide-field surveys such
as Euclid and Roman, and since sub-millimetre galaxies are predominantly very
red at optical/near-infrared wavelengths, they will tend to appear in
near-infrared channels only. Extrapolating to the Euclid-Wide survey, we
predict tens of thousands of strongly lensed near-infrared galaxies. This will
be transformative for the study of dusty star-forming galaxies at cosmic noon,
but will be a contaminant population in searches for strongly lensed
ultra-high-redshift galaxies in Euclid and Roman.Comment: 8 pages; 4 figures; 4 tables; submitted to MNRA
The Personal Sequence Database: a suite of tools to create and maintain web-accessible sequence databases
Background: Large molecular sequence databases are fundamental resources for modern\ud
bioscientists. Whether for project-specific purposes or sharing data with colleagues, it is often\ud
advantageous to maintain smaller sequence databases. However, this is usually not an easy task for\ud
the average bench scientist.\ud
\ud
Results: We present the Personal Sequence Database (PSD), a suite of tools to create and\ud
maintain small- to medium-sized web-accessible sequence databases. All interactions with PSD\ud
tools occur via the internet with a web browser. Users may define sequence groups within their\ud
database that can be maintained privately or published to the web for public use. A sequence group\ud
can be downloaded, browsed, searched by keyword or searched for sequence similarities using\ud
BLAST. Publishing a sequence group extends these capabilities to colleagues and collaborators. In\ud
addition to being able to manage their own sequence databases, users can enroll sequences in\ud
BLASTAgent, a BLAST hit tracking system, to monitor NCBI databases for new entries displaying\ud
a specified level of nucleotide or amino acid similarity.\ud
\ud
Conclusion: The PSD offers a valuable set of resources unavailable elsewhere. In addition to\ud
managing sequence data and BLAST search results, it facilitates data sharing with colleagues,\ud
collaborators and public users. The PSD is hosted by the authors and is available at http://\ud
bioinfo.cgrb.oregonstate.edu/psd/
Targeted suppression of autoreactive CD8+ T-cell activation using blocking anti-CD8 antibodies
CD8+ T-cells play a role in the pathogenesis of autoimmune diseases such as multiple sclerosis and type 1 diabetes. However, drugs that target the entire CD8+ T-cell population are not desirable because the associated lack of speci city can lead to unwanted consequences, most notably an enhanced susceptibility to infection. Here, we show that autoreactive CD8+ T-cells are highly dependent on CD8 for ligand-induced activation via the T-cell receptor (TCR). In contrast, pathogen-speci c CD8+ T-cells are relatively CD8-independent. These generic di erences relate to an intrinsic dichotomy that segregates self-derived and exogenous antigen-speci c TCRs according to the monomeric interaction a nity with cognate peptide-major histocompatibility complex class I (pMHCI). As a consequence, “blocking” anti-CD8 antibodies can suppress autoreactive CD8+ T-cell activation in a relatively selective manner. These ndings provide a rational basis for the development and in vivo assessment of novel therapeutic strategies that preferentially target disease-relevant autoimmune responses within the CD8+ T-cell compartment
Excess Mucin Impairs Subglottic Epithelial Host Defense in Mechanically Ventilated Patients
Rationale:
Aspiration of infective subglottic secretions causes ventilator-associated pneumonia (VAP) in mechanically ventilated patients. Mechanisms underlying subglottic colonization in critical illness have not been defined, limiting strategies for targeted prevention of VAP.
Objectives:
To characterize subglottic host defense dysfunction in mechanically ventilated patients in the intensive care unit (ICU). To determine whether subglottic mucin contributes to neutrophil phagocytic impairment and bacterial growth.
Methods:
Prospective subglottic sampling in mechanically ventilated patients (intubated for four or more days), and newly intubated control patients (intubated for less than 30 minutes). Isolation and culture of primary subglottic epithelial cells from controls. Laboratory analysis of host innate immune defenses.
Measurements and Main Results:
Twenty-four patients in the ICU and 27 newly intubated control patients were studied. Subglottic ICU samples had significantly reduced microbiological diversity and contained potential respiratory pathogens. The subglottic microenvironment in ICU was characterized by neutrophilic inflammation, significantly increased pro-inflammatory cytokines and neutrophil proteases, and altered physical properties of subglottic secretions, including accumulation of mucins. Subglottic mucin from ICU patients impaired the capacity of neutrophils to phagocytose and kill bacteria. Phagocytic function was reversible upon treatment with a mucolytic agent. Subglottic mucus promoted growth and invasion of bacterial pathogens in a novel air-liquid interface model of primary human subglottic epithelium.
Conclusions:
Mechanical ventilation in ICU is characterized by substantial mucin secretion and neutrophilic inflammation. Mucin impairs neutrophil dysfunction and promotes bacterial growth. Mucolytic agents reverse mucin-mediated neutrophil dysfunction. Enhanced mucus disruption and removal has potential to augment preventive benefits of subglottic drainage
Prospectus, April 18, 1984
CHORAL UNION DEMANDING AND REWARDING; News Digest; Is your child part of the identi-child program?; Budding playwrights get chance to have work produced; PC Happenings: Parkland wins Automotive Contest, German Club annual Springfest, EMT workshop offered, Petitions available for Stu-Go, Stu-Go lacks quorum; Here Comes the Easter Bunny (or the Easter Hare?); Faces We Make; Former Prospectus entertainment writer: Alender services held; Strange things at the library; Only Food Service Management course in area: Sutton leads Food Service Management program; Criminal justice program well rounded; Running may increase protein need; Easter means Easter egg time; Second Wind hosts race; Did You Know...; Classifieds; Creative Corner...Especially for you!!: Recollections, She\u27s More than a Nurse, You are a corn-fed steak..., Memories..., A fire burns, AKTING??????????????..., Sometimes in their heed to tact..., Clouds, Disturb Not the Dead, Follow the Wind, I don\u27t know why I bother..., Innoncent Eyes, Please tell me what it is you want..., Running scared from yourself and tripped, babe..., Time Bomb, Don\u27t go away--Linger on..., Class, Raggedy Ann lay in the back of an old station wagon..., Too Late, To God; Ice Capades comes to town: Skaters say it\u27s hard work but well worth it; few surprises during Hollywood\u27s biggest night; \u27Queen\u27 film at Assembly Hall; Director shines in film; \u27Go-Go\u27s\u27 are back on track; \u27Weird Al\u27 hits big time; Fan Club to host film; Parkland College 1984 baseball roster; Cobra men lose two; 1984 Parkland Outdoor Track Bests; Sports Digest; Women lose twin bill; Prospectus survey resultshttps://spark.parkland.edu/prospectus_1984/1024/thumbnail.jp
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