Semiconductor compounds are widely used for photocatalytic hydrogen production applications, where photogenerated electron-hole pairs are exploited to induce catalysis. Recently, powders of a ...metallic oxide (Sr
NbO
, 0.03<x<0.20) were reported to show competitive photocatalytic efficiencies under visible light, which was attributed to interband absorption. This discovery expanded the range of materials available for optimized performance as photocatalysts. Here we study epitaxial thin films of SrNbO
and find that their bandgaps are ∼4.1 eV. Surprisingly, the carrier density of the conducting phase exceeds 10
cm
and the carrier mobility is only 2.47 cm
V
s
. Contrary to earlier reports, the visible light absorption at 1.8 eV (∼688 nm) is due to the plasmon resonance, arising from the large carrier density. We propose that the hot electron and hole carriers excited via Landau damping (during the plasmon decay) are responsible for the photocatalytic property of this material under visible light irradiation.
The transcription factor CREB (cAMP Response-Element Binding Protein) is overexpressed in the majority of acute myeloid leukemia (AML) patients, and this is associated with a worse prognosis. ...Previous work revealed that CREB overexpression augmented AML cell growth, while CREB knockdown disrupted key AML cell functions in vitro. In contrast, CREB knockdown had no effect on long-term hematopoietic stem cell activity in mouse transduction/transplantation assays. Together, these studies position CREB as a promising drug target for AML. To test this concept, a small molecule inhibitor of CREB, XX-650-23, was developed. This molecule blocks a critical interaction between CREB and its required co-activator CBP (CREB Binding Protein), leading to disruption of CREB-driven gene expression. Inhibition of CBP-CREB interaction induced apoptosis and cell-cycle arrest in AML cells, and prolonged survival in vivo in mice injected with human AML cells. XX-650-23 had little toxicity on normal human hematopoietic cells and tissues in mice. To understand the mechanism of XX-650-23, we performed RNA-seq, ChIP-seq and Cytometry Time of Flight with human AML cells. Our results demonstrate that small molecule inhibition of CBP-CREB interaction mostly affects apoptotic, cell-cycle and survival pathways, which may represent a novel approach for AML therapy.
Background. Influenza vaccines may be reformulated annually because of antigenic drift in influenza viruses. However, the relationship between antigenic characteristics of circulating viruses and ...vaccine effectiveness (VE) is not well understood. We conducted an assessment of the effectiveness of US influenza vaccines during the 2010–2011 season. Methods. We performed a case—control study comparing vaccination histories between subjects with acute respiratory illness with positive real-time reverse transcription polymerase chain reaction for influenza and influenza test-negative controls. Subjects with acute respiratory illness of ≤7 days duration were enrolled in hospitals, emergency departments, or outpatient clinics in communities in 4 states. History of immunization with the 2010–2011 vaccine was ascertained from vaccine registries or medical records. Vaccine effectiveness was estimated in logistic regression models adjusted for study community, age, race, insurance status, enrollment site, and presence of a high-risk medical condition. Results. A total of 1040 influenza-positive cases and 3717 influenza-negative controls were included from the influenza season, including 373 cases of influenza A(H1N1), 334 cases of influenza A(H3N2), and 333 cases of influenza B. Overall adjusted VE was 60% (95% confidence interval CI, 53%–66%). Age-specific VE estimates ranged from 69% (95% CI, 56%–77%) in children aged 6 months–8 years to 38% (95% CI, −16% to 67%) in adults aged ≥65 years. Conclusions. The US 2010–2011 influenza vaccines were moderately effective in preventing medically attended influenza during a season when all 3 vaccine strains were antigenically similar to circulating viruses. Continued monitoring of influenza vaccines in all age groups is important, particularly as new vaccines are introduced.
The new Surrey ion beam analysis facility Simon, A.; Jeynes, C.; Webb, R.P. ...
Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms,
06/2004, Volume:
219
Journal Article
Peer reviewed
We present the characteristics of an ion beam analysis facility based on a fully computer controlled 2 MV Tandetron
TM commissioned in 2002. The terminal voltage temperature stability is measured ...using the 3036 keV
16O(α,α)
16O resonance. A microbeam beamline with an Oxford triplet lens and a coolable sample holder has been built. We report new temperature dependent time-resolved IBIC measurements from CZT detectors that illustrate the capability of the system. A millibeam beamline has been built with a 6-axis goniometer capable of handling 100 mm wafers through an airlock with a
z-axis for the precise location of the sample surface at the eucentric point. This instrument is designed for routine RBS/ERD and channelling applications, and incorporates a versatile controller capable of fully automated data collection.
Respiratory syncytial virus (RSV) infection is a leading cause of hospitalization among infants. However, estimates of the RSV hospitalization burden have varied, and precision has been limited by ...the use of age strata grouped in blocks of 6 to ≥ 12 months.
We analyzed data from a 5-year, prospective, population-based surveillance for young children who were hospitalized with laboratory-confirmed (reverse-transcriptase polymerase chain reaction) RSV acute respiratory illness (ARI) during October through March 2000-2005. The total population at risk was stratified by month of age by birth certificate information to yield hospitalization rates.
There were 559 (26%) RSV-infected children among the 2149 enrolled children hospitalized with ARI (85% of all eligible children with ARI). The average RSV hospitalization rate was 5.2 per 1000 children <24 months old. The highest age-specific rate was in infants 1 month old (25.9 per 1000 children). Infants ≤ 2 months of age, who comprised 44% of RSV-hospitalized children, had a hospitalization rate of 17.9 per 1000 children. Most children (79%) were previously healthy. Very preterm infants (<30 weeks' gestation) accounted for only 3% of RSV cases but had RSV hospitalization rates 3 times that of term infants.
Young infants, especially those who were 1 month old, were at greatest risk of RSV hospitalization. Four-fifths of RSV-hospitalized infants were previously healthy. To substantially reduce the burden of RSV hospitalizations, effective general preventive strategies will be required for all young infants, not just those with risk factors.
In agreement with previous work, adult rats given selective lesions to dopamine (DA)-containing neurons as neonates exhibited a greater behavioral sensitization to repeated phencyclidine (PCP) ...treatment in comparison to sham-lesioned controls. Acute administration of olanzapine (1–5 mg/kg ip) or clozapine (15 mg/kg ip) decreased sensitized PCP-induced activity in both lesioned and control animals. Acute haloperidol (0.5 mg/kg ip) had no impact on PCP responsiveness in lesioned animals, but significantly antagonized PCP effects in sham-lesioned controls. Ketanserin, a selective 5-HT
2A/5-HT
2C-receptor antagonist, significantly reduced PCP activation in both lesioned and control rats, suggesting that the efficacy of atypical antipsychotics against PCP-induced sensitized responses may be mediated by one of the 5-HT
2-receptor subtypes. A 6-week chronic regimen of orally administered olanzapine, clozapine, or haloperidol failed to block the sensitization induced by repeated PCP exposure. However, a 10-month oral olanzapine treatment significantly blunted the behavioral sensitization to repeated PCP exposure in lesioned animals, even after withdrawal from chronic olanzapine for more than 3 weeks. A 10-month oral haloperidol treatment had no effect on the sensitization induced by repeated PCP dosing. The persistent effect of chronic olanzapine administration on PCP sensitization may be relevant to the chronic therapeutic efficacy of atypical antipsychotics treating schizophrenia—a clinical syndrome linked to enhanced sensitivity to
N-methyl-
d-aspartate (NMDA)-receptor antagonists.
The primary role of respiratory syncytial virus (RSV) in causing infant hospitalizations is well recognized, but the total burden of RSV infection among young children remains poorly defined.
We ...conducted prospective, population-based surveillance of acute respiratory infections among children under 5 years of age in three U.S. counties. We enrolled hospitalized children from 2000 through 2004 and children presenting as outpatients in emergency departments and pediatric offices from 2002 through 2004. RSV was detected by culture and reverse-transcriptase polymerase chain reaction. Clinical information was obtained from parents and medical records. We calculated population-based rates of hospitalization associated with RSV infection and estimated the rates of RSV-associated outpatient visits.
Among 5067 children enrolled in the study, 919 (18%) had RSV infections. Overall, RSV was associated with 20% of hospitalizations, 18% of emergency department visits, and 15% of office visits for acute respiratory infections from November through April. Average annual hospitalization rates were 17 per 1000 children under 6 months of age and 3 per 1000 children under 5 years of age. Most of the children had no coexisting illnesses. Only prematurity and a young age were independent risk factors for hospitalization. Estimated rates of RSV-associated office visits among children under 5 years of age were three times those in emergency departments. Outpatients had moderately severe RSV-associated illness, but few of the illnesses (3%) were diagnosed as being caused by RSV.
RSV infection is associated with substantial morbidity in U.S. children in both inpatient and outpatient settings. Most children with RSV infection were previously healthy, suggesting that control strategies targeting only high-risk children will have a limited effect on the total disease burden of RSV infection.
The pharmacology of the enantiomers of threo-methylphenidate (MPH) was evaluated in the rat to assess the relative contribution of each isomer to central and peripheral actions of the racemic drug. ...Fractional recrystallization of binaphthyl phosphate salts of dl-threo-MPH allowed resolution of d-threo-MPH and 92% enrichment of l-threo-MPH. The enantiomeric disposition was monitored using gas chromatographic separation of trifluoroacetylprolyl diastereomeric derivatives. The activity of the d-isomer was greater than the l-isomer in the induction of locomotor activity and the inhibition of tritiated dopamine and l-norepinephrine uptake into striatal and hypothalamic synaptosomes, respectively. Neither isomer produced a significant change in the spontaneous release of tritiated catecholamines from synaptosomes. Destruction of catecholaminergic neurons by 6-hydroxydopamine pretreatment attenuated the locomotor response to d-threo-MPH, indicating the involvement of catecholaminergic neural pathways in the locomotor response. Only the d-enantiomer significantly potentiated the pressor responses to i.v. l-norepinephrine. Receptor site stereoselectively for threo- vs. erythro-MPH is discussed in terms of isomer conformational preferences. These results suggest that synaptic inhibition of catecholamine uptake by d-threo-MPH may be involved fundamentally in behavioral and pressor effects of the racemic drug.
The use of graphene electronics in space will depend on the radiation hardness of graphene. The damage threshold of graphene samples, subjected to 2
MeV H
+ irradiation, was found to increase with ...layer number and also when the graphene layer was supported by a substrate. The thermal properties of graphene as a function of the number of layers or as influenced by the substrate argue against a thermal model for the production of damage by the ion beam. We propose a model of intense electronically-stimulated surface desorption of the atoms as the most likely process for this damage mechanism.
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