bluuebunny/crossref_metadata_2025_split huggingface dataset:
Bright polar mesospheric clouds formed by main engine exhaust from the space shuttle's final launch
Authors: Stevens Michael H. , Lossow Stefan , Fiedler Jens , Baumgarten Gerd , Lübken Franz‐Josef , Hallgren Kristofer , Hartogh Paul , Randall Cora E. , Lumpe Jerry , Bailey Scott M. , Niciejewski R. , Meier R. R. , Plane John M. C. , Kochenash Andrew J. , Murtagh Donal P. , Englert Christoph R. 
Published: August 2012

The space shuttle launched for the last time on 8 July 2011. As with most shuttle launches, the three main engines injected about 350 t of water vapor between 100 and 115 km off the east coast of the United States during its ascent to orbit. We follow the motion of this exhaust with a variety of satellite and ground‐based data sets and find that (1) the shuttle water vapor plume spread out horizontally in all directions over a distance of 3000 to 4000 km in 18 h, (2) a portion of the plume reached northern Europe in 21 h to form polar mesospheric clouds (PMCs) that are brighter than over 99% of all PMCs observed in that region, and (3) the observed altitude dependence of the particle size is reversed with larger particles above smaller particles. We use a one‐dimensional cloud formation model initialized with predictions of a plume diffusion model to simulate the unusually bright PMCs. We find that eddy mixing can move the plume water vapor down to the mesopause near 90 km where ice particles can form. If the eddy diffusion coefficient is 400 to 1000 m2/s, the predicted integrated cloud brightness is in agreement with both satellite and ground‐based observations of the shuttle PMCs. The propellant mass of the shuttle is about 20% of that from all vehicles launched during the northern 2011 PMC season. We suggest that the brightest PMC population near 70°N is formed by space traffic exhaust.
Change of Beclin‐1 dependent on ATP, [Ca2+]i and MMP in PC12 cells following oxygen‐glucose deprivation‐reoxygenation injury
Authors: Mo Zhentao , Fang Yongqi , He Yuping , Ke Xuehong 
Published: August 2012

AbstractAutophagy is usually up‐regulated to provide more ATP in response to starvation or OGD (oxygen‐glucose deprivation), but the relationship between autophagy and ATP, [Ca2+]i (intracellular free Ca2+ concentration) or MMP (mitochondrial membrane potential) during reoxygenation is not yet fully clear. The role of autophagy is unknown in PC12 cells subjected to 2 h OGD with different time points of reoxygenation. In the present study, we showed that Beclin‐1 was up‐regulated beginning at 0 h reoxygenation peaking at 24 h and lasting for 48 h. Cell viability was decreased from 0 to 48 h reoxygenation, reaching its minimum at 10 h reoxygenation. ATP was decreased from 0 to 10 h reoxygenation, reaching its minimum at 4 h reoxygenation. A significant negative correlation was observed between ATP and Beclin‐1 (r = −0.61, P<0.05) at 0 h reoxygenation, but ATP was not significant related (r = 0.24, P>0.05) to Beclin‐1 at 24 h reoxygenation. Besides, Nimodipine, a calcium antagonist, significantly reduced [Ca2+]i and Beclin‐1, but increased MMP in OGD/R‐treated cells. At 24 h reoxygenation, Beclin‐1 expression reached its maximum, cell viability continued to increase, and ATP was higher than that before OGD. These results suggest that energy metabolism dysfunction can induce autophagy during OGD in PC12 cells. Increased [Ca2+]i and decreased MMP may induce autophagy during reoxygenation in PC12 cells. Autophagy may be a protective effect on PC12 cells treated with different time points of reoxygenation after 2 h OGD.
Arthropods in amber from the Triassic Period
Authors: Schmidt Alexander R. , Jancke Saskia , Lindquist Evert E. , Ragazzi Eugenio , Roghi Guido , Nascimbene Paul C. , Schmidt Kerstin , Wappler Torsten , Grimaldi David A. 
Published: August 2012

The occurrence of arthropods in amber exclusively from the Cretaceous and Cenozoic is widely regarded to be a result of the production and preservation of large amounts of tree resin beginningca.130 million years (Ma) ago. Abundant 230 million-year-old amber from the Late Triassic (Carnian) of northeastern Italy has previously yielded myriad microorganisms, but we report here that it also preserves arthropods some 100 Ma older than the earliest prior records in amber. The Triassic specimens are a nematoceran fly (Diptera) and two disparate species of mites,Triasacarus fedeleigen. et sp. nov., andAmpezzoa triassicagen. et sp. nov. These mites are the oldest definitive fossils of a group, the Eriophyoidea, which includes the gall mites and comprises at least 3,500 Recent species, 97% of which feed on angiosperms and represents one of the most specialized lineages of phytophagous arthropods. Antiquity of the gall mites in much their extant form was unexpected, particularly with the Triassic species already having many of their present-day features (such as only two pairs of legs); further, it establishes conifer feeding as an ancestral trait. Feeding by the fossil mites may have contributed to the formation of the amber droplets, but we find that the abundance of amber during the Carnian (ca.230 Ma) is globally anomalous for the pre-Cretaceous and may, alternatively, be related to paleoclimate. Further recovery of arthropods in Carnian-aged amber is promising and will have profound implications for understanding the evolution of terrestrial members of the most diverse phylum of organisms.
Broadband cascading of second-order nonlinearity in randomized nonlinear photonic crystal
Authors: Sheng Yan , Ma Dongli , Ren Mingliang , Chen Baoqin , Roppo Vito , Li Zhiyuan , Koynov Kaloian , Krolikowski Wieslaw 
Published: August 2012

Abstract
We study both experimentally and theoretically optical parametric process in one-dimensional nonlinear photonic crystal with random variation to the sign of the second-order nonlinear coefficient. We demonstrate that the structure randomness enables broadband third-harmonic generation via cascading of two second-order nonlinear parametric wave interactions with the overall conversion efficiency higher than previously recorded in fully disordered media such as the as-grown strontium barium niobate crystal. Furthermore, thanks to the one-dimensional modulation of the second-order nonlinearity, the emitted broadband harmonics preserve well the spatial intensity profile of the incident fundamental light beam, a feature critical for applications of optical frequency conversion but unavailable in two-dimensional fully random media due to the beam divergence caused by the simultaneous emission of noncollinear harmonic.
Removal of strain relaxation induced defects by flushing of InAs quantum dots
Authors: Polojärvi Ville , Schramm Andreas , Aho Arto , Tukiainen Antti , Guina Mircea 
Published: August 2012

Abstract
We report the effect of indium flushing on the electrical and optical properties of strain-relaxed InAs quantum dots (QDs) embedded in GaAs Schottky diodes. The InAs QDs were intentionally grown beyond the critical thickness to induce plastically relaxed QDs. The samples were fabricated by molecular beam epitaxy on GaAs(1 0 0) substrates using continuous and cycled InAs deposition. Deep level transient spectroscopy (DLTS) experiments show broad dislocation-induced defects in non-flushed samples. We show by DLTS that indium flushing after QD deposition decreases remarkably the amount of electron traps in the QD layer and suppresses the defect formation into GaAs capping layer. Using capacitance–voltage measurements we observed that the flushed samples exhibit a recovery of electron confinement in the QD states. Furthermore, we used photoluminescence experiments to analyse the effects of direct versus cycled InAs deposition and indium flushing steps.
Effect of thermal treatment and ageing on IR transmission and visible photoluminescence of nanostructured aluminum oxyhydroxide
Authors: Karlash A Yu , Skryshevsky V A , Khodan A N , Kanaev A V , Gayvoronsky V Ya 
Published: August 2012

Abstract
IR transmission and visible photoluminescence (PL) were studied in raw nanoporous aluminum oxyhydroxide (NOA) and in samples after thermal treatment at different temperatures. Structural and chemical modifications of the NOA sample were related to the water content and adsorption/desorption process at the surface. The differences observed in the FTIR spectra in vacuum and after ageing of the samples can be explained by the effects of molecular water and OH− groups on the stability of the low-temperature phases of NOA. A considerable increase in PL intensity and spectrum expansion to longer wavelengths were observed in all NOA samples after water desorption. This was accompanied by strong changes in the PL decay kinetics. Quenching of the fast luminescent decay and low-energy transitions in aged samples were observed after ageing of the samples. Partial passivation of the NOA surface and defective sites under ambient conditions is discussed.
Another approach to the thin-film Γ-limit of the micromagnetic free energy in the regime of small samples
Authors: Kreisbeck Carolin 
Published: August 2012

The asymptotic behavior of the micromagnetic free energy governing a ferromagnetic film is studied as its thickness gets smaller and smaller compared to its cross section. Here the static Maxwell equations are treated as a Murat’s constant-rank PDE constraint on the energy functional. In contrast to previous work, this approach allows us to keep track of the induced magnetic field without solving the magnetostatic equations. In particular, the mathematical results of Gioia and James [Proc. R. Soc. Lond. A453 (1997), pp. 213–223] regarding convergence of minimizers are recovered by giving a characterization of the correspondingΓ\Gamma-limit.
Les
Réflexions
du marquis d'Argenson sur la liberté des historiens
Authors: Balázs Péter 
Published: August 2012

Abstract

L'article traite d'un ouvrage pratiquement inconnu — publié dans les
Mémoires de littérature, tirés des registres de l'Académie royale des inscriptions et belles-lettres
— du marquis d'Argenson (1694–1757) écrit au sujet de la liberté des historiens au sein de la monarchie française. Son point de départ est une comparaison suivie des grands historiens de l'Antiquité avec les plus illustres des ‘chroniqueurs’ français. Le marquis voit la raison de la supériorité des historiens antiques sur les modernes dans la différence des deux régimes: tandis que les républiques antiques se caractérisaient par la liberté de leurs citoyens, la monarchie française ne réserve que la servitude à ses sujets. Dans ce qui suit j'essaye de contextualiser cette affirmation très catégorique, d'abord en définissant sa place dans les débats contemporains portant sur l'histoire et l'écriture historique, puis en montrant que son auteur, qui s'efforce dans ses ouvrages majeurs de contribuer à la ‘républicanisation de la monarchie’, recourt souvent à des interprétations diamétralement opposées à celle qui est en œuvre dans le texte ici examiné.
Event-related Functional Magnetic Resonance Imaging of a Low Dose of Dexmedetomidine that Impairs Long-term Memory
Authors: Hayama Hiroki R. , Drumheller Kristin M. , Mastromonaco Mark , Reist Christopher , Cahill Lawrence F. , Alkire Michael. T. 
Published: August 2012

Abstract

Background
Work suggests the amnesia from dexmedetomidine (an α2-adrenergic agonist) is caused by a failure of information to be encoded into long-term memory and that dexmedetomidine might differentially affect memory for emotionally arousing material. We investigated these issues in humans using event-related neuroimaging to reveal alterations in brain activity and subsequent memory effects associated with drug exposure.

Methods
Forty-eight healthy volunteers received a computer-controlled infusion of either placebo or low-dose dexmedetomidine (target = 0.15 ng/ml plasma) during neuroimaging while they viewed and rated 80 emotionally arousing (e.g., graphic war wound) and 80 nonarousing neutral (e.g., cup) pictures for emotional arousal content. Long-term picture memory was tested 4 days later without neuroimaging. Imaging data were analyzed for drug effects, emotional processing differences, and memory-related changes with statistical parametric mapping-8.

Results
Dexmedetomidine impaired overall (mean ± SEM) picture memory (placebo: 0.58 ± 0.03 vs. dexmedetomidine: 0.45 ± 0.03, P = 0.001), but did not differentially modulate memory as a function of item arousal. Arousing pictures were better remembered for both groups. Dexmedetomidine had regionally heterogeneous effects on brain activity, primarily decreasing it in the cortex and increasing it in thalamic and posterior hippocampal regions. Nevertheless, a single subsequent memory effect for item memory common to both groups was identified only in the left hippocampus/amygdala. Much of this effect was found to be larger for the placebo than dexmedetomidine group.

Conclusion
Dexmedetomidine impaired long-term picture memory, but did not disproportionately block memory for emotionally arousing items. The memory impairment on dexmedetomidine corresponds with a weakened hippocampal subsequent memory effect.
Modifying Methoxycarbonyl Etomidate Inter-Ester Spacer Optimizes In Vitro Metabolic Stability and In Vivo Hypnotic Potency and Duration of Action
Authors: Husain S. Shaukat , Pejo Ervin , Ge Rile , Raines Douglas E. 
Published: August 2012

Background
Methoxycarbonyl etomidate is the prototypical very rapidly metabolized etomidate analog. Initial studies suggest that it may be too short acting for many clinical uses. We hypothesized that its duration of action could be lengthened and clinical utility broadened by incorporating specific aliphatic groups into the molecule to sterically protect its ester moiety from esterase-catalyzed hydrolysis. To test this hypothesis, we developed a series of methoxycarbonyl etomidate analogs (spacer-linked etomidate esters) containing various aliphatic-protecting groups and spacer lengths.

Methods
Spacer-linked etomidate esters were synthesized and their hypnotic potencies and durations of action following bolus administration were measured in rats using a loss-of-righting reflexes assay. Octanol:water partition coefficients and metabolic half-lives in pooled rat blood were determined chromatographically.

Results
All spacer-linked etomidate esters produced hypnosis rapidly and in a dose-dependent manner. ED50s for loss of righting reflexes ranged from 0.69 ± 0.04 mg/kg for cyclopropyl-methoxycarbonyl metomidate to 11.1 ± 0.8 mg/kg for methoxycarbonyl metomidate. The slope of a plot of the duration of loss of righting reflexes versus the logarithm of the dose ranged 12-fold among spacer-linked etomidate esters, implying widely varying brain clearance rates. The in vitro metabolic half-lives of these compounds in rat blood varied by more than two orders of magnitude and were diastereometrically selective.

Conclusions
We created 13 new analogs of methoxycarbonyl etomidate and identified two that have significantly higher potency and potentially address the too-brief duration of action for methoxycarbonyl etomidate. This work may provide a blueprint for optimizing the pharmacological properties of other soft drugs.
Complexes with Mixed Primary and Secondary Cellulose Synthases Are Functional in Arabidopsis Plants
Authors: Carroll Andrew , Mansoori Nasim , Li Shundai , Lei Lei , Vernhettes Samantha , Visser Richard G.F. , Somerville Chris , Gu Ying , Trindade Luisa M. 
Published: August 2012

Abstract
In higher plants, cellulose is synthesized by so-called rosette protein complexes with cellulose synthases (CESAs) as catalytic subunits of the complex. The CESAs are divided into two distinct families, three of which are thought to be specialized for the primary cell wall and three for the secondary cell wall. In this article, the potential of primary and secondary CESAs forming a functional rosette complex has been investigated. The membrane-based yeast two-hybrid and biomolecular fluorescence systems were used to assess the interactions between three primary (CESA1, CESA3, CESA6), and three secondary (CESA4, CESA7, CESA8) Arabidopsis (Arabidopsis thaliana) CESAs. The results showed that all primary CESAs can physically interact both in vitro and in planta with all secondary CESAs. Although CESAs are broadly capable of interacting in pairwise combinations, they are not all able to form functional complexes in planta. Analysis of transgenic lines showed that CESA7 can partially rescue defects in the primary cell wall biosynthesis in a weak cesa3 mutant. Green fluorescent protein-CESA protein fusions revealed that when CESA3 was replaced by CESA7 in the primary rosette, the velocity of the mixed complexes was slightly faster than the native primary complexes. CESA1 in turn can partly rescue defects in secondary cell wall biosynthesis in a cesa8ko mutant, resulting in an increase of cellulose content relative to cesa8ko. These results demonstrate that sufficient parallels exist between the primary and secondary complexes for cross-functionality and open the possibility that mixed complexes of primary and secondary CESAs may occur at particular times.
Nitric Oxide-Mediated Maintenance of Redox Homeostasis Contributes to NPR1-Dependent Plant Innate Immunity Triggered by Lipopolysaccharides
Authors: Sun Aizhen , Nie Shengjun , Xing Da 
Published: August 2012

Abstract
The perception of lipopolysaccharides (LPS) by plant cells can lead to nitric oxide (NO) production and defense gene induction. However, the signaling cascades underlying these cellular responses have not yet been resolved. This work investigated the biosynthetic origin of NO and the role of NONEXPRESSOR OF PATHOGENESIS-RELATED GENES1 (NPR1) to gain insight into the mechanism involved in LPS-induced resistance of Arabidopsis (Arabidopsis thaliana). Analysis of inhibitors and mutants showed that LPS-induced NO synthesis was mainly mediated by an arginine-utilizing source of NO generation. Furthermore, LPS-induced NO caused transcript accumulation of alternative oxidase genes and increased antioxidant enzyme activity, which enhanced antioxidant capacity and modulated redox state. We also analyzed the subcellular localization of NPR1 to identify the mechanism for protein-modulated plant innate immunity triggered by LPS. LPS-activated defense responses, including callose deposition and defense-related gene expression, were found to be regulated through an NPR1-dependent pathway. In summary, a significant NO synthesis induced by LPS contributes to the LPS-induced defense responses by up-regulation of defense genes and modulation of cellular redox state. Moreover, NPR1 plays an important role in LPS-triggered plant innate immunity.
Randomised clinical trial: low‐volume bowel preparation for colonoscopy ‐ a comparison between two different PEG‐based formulations
Authors: Repici A. , Cestari R. , Annese V. , Biscaglia G. , Vitetta E. , Minelli L. , Trallori G. , Orselli S. , Andriulli A. , Hassan C. 
Published: August 2012

SummaryBackgroundLow‐volume bowel preparations with polyethylene glycol (PEG) have been shown to provide an equivalent cleansing with improved tolerability as compared with standard PEG bowel preparation for colonoscopy. A new iso‐osmotic sulphate‐free formulation of PEG‐Citrate‐Simethicone (PEG‐CS) in combination with bisacodyl has been recently developed.AimTo compare the quality of bowel cleansing with PEG‐CS with bisacodyl vs. PEG‐Ascorbate (PEG‐ASC) in adult out‐patients undergoing colonoscopy.MethodsRandomised, observer‐blind, parallel group study in adult out‐patients undergoing colonoscopy in five Italian centres. Both preparations were taken the evening before the procedure. Subjects were instructed to take 2–4 tablets of 5 mg bisacodyl at 16:00 hours and 2 L of PEG‐CS at 20:00 hours or 2 L of PEG‐ASC plus 1 L of additional water the day before colonoscopy. Bowel cleansing was evaluated according to the Boston Bowel Preparation Scale (≥6 scores were considered as ‘clinical success’), and mucosal visibility according to a 3‐point scale. Tolerability, acceptability and compliance were also evaluated.ResultsFour hundred and eight patients were randomly allocated to PEG‐CS and bisacodyl (n = 204, male patient 48%, mean age 59.1 years) or PEG‐ASC (n = 204, male patient 51%, age 59.4 years). In the planned per‐protocol analysis, the rate of successful preparation was 79.1% following PEG‐CS with bisacodyl, and 70% following PEG‐ASC (P < 0.05). Mucosal visibility was evaluated as optimal in 56.1% in the PEG‐CS and bisacodyl and 46.3% in the PEG‐ASC group (P < 0.05). There were no serious adverse events (AE) in each of the two experimental groups. Two subjects in the PEG‐ASC group discontinued the study because of AE.ConclusionsPolyethylene glycol‐Citrate‐Simethicone in combination with bisacodyl was more effective for bowel cleansing than PEG‐ASC for out‐patient colonoscopy. Tolerability, safety, acceptability and compliance of the two low‐volume bowel preparations were similar.
High dose vitamin D therapy for chronic pain in children and adolescents with sickle cell disease: results of a randomized double blind pilot study
Authors: Osunkwo Ifeyinwa , Ziegler Thomas R. , Alvarez Jessica , McCracken Courtney , Cherry Korin , Osunkwo Chinyere E. , Ofori‐Acquah Solomon F. , Ghosh Samit , Ogunbobode Adeolu , Rhodes Jim , Eckman James R. , Dampier Carlton , Tangpricha Vin 
Published: August 2012

SummaryWe report results of a pilot study of high‐dose vitamin D in sickle cell disease (SCD). Subjects were given a 6‐week course of oral high‐dose cholecalciferol (4000–100 000 IU per week) or placebo and monitored prospectively for a period of six months. Vitamin D insufficiency and deficiency was present at baseline in 82·5% and 52·5% of subjects, respectively. Subjects who received high‐dose vitamin D achieved higher serum 25‐hydroxyvitamin D, experienced fewer pain days per week, and had higher physical activity quality‐of‐life scores. These findings suggest a potential benefit of vitamin D in reducing the number of pain days in SCD. Larger prospective studies with longer duration are needed to confirm these effects.
Identification, functional analysis, prevalence and treatment of monocarboxylate transporter 8 (MCT8) mutations in a cohort of adult patients with mental retardation
Authors: Visser W. Edward , Vrijmoeth Paul , Visser Frank E. , Arts Willem Frans M. , van Toor Hans , Visser Theo J. 
Published: August 2012

SummaryObjectiveMonocarboxylate transporter 8 (MCT8) is an essential thyroid hormone (TH) transporter as humans with MCT8 mutations have severe neurological and endocrine abnormalities. The objectives are (i) to identify novel MCT8 mutations and (ii) to assess their functional relevance; (iii) to describe the effects of block‐and‐replace treatment in an MCT8 patient.DesignThe TOP‐R study is a cross‐sectional nation‐wide multicentre study.PatientsSubjects with unexplained mental retardation (MR) were screened for MCT8 mutations.ResultsWe identified three mutations: p.F501del (previously described), p.L492P and p.T162T. The F501del and L492P mutants, but not the T162T mutant, showed diminished T3, T4 and rT3 transport in transfected cells. TH transport in T162T fibroblasts was also not affected. One patient was treated with block‐and‐replace therapy to normalize serum TH levels. The results indicated a slow onset of the decrease in serum T4 and T3 by successive treatment with methimazole and PTU, and eventually their complete normalization by administration of LT4 with PTU but not with methimazole. The frequency of MCT8 mutations in males with X‐linked MR approximately 3·9%.ConclusionsWe identified several MCT8 mutations in a cohort of subjects with unexplained MR. We demonstrated the pathogenicity of two missense mutations. The synonymous variant did not affect TH transport. Block‐and‐replace therapy of one patient reversed the TH abnormalities. Our data suggest a decreased TH secretion rate and an increased T4 to T3 conversion by the type I deiodinase in patients with MCT8 mutations. Our study indicates that MCT8 mutations are a relatively frequent cause of X‐linked MR.