Abstract
Conventional spectroscopies are not sufficiently selective to comprehensively understand the behaviour of trapped carriers in perovskite solar cells, particularly under their working ...conditions. Here we use infrared optical activation spectroscopy (i.e., pump-push-photocurrent), to observe the properties and real-time dynamics of trapped carriers within operando perovskite solar cells. We compare behaviour differences of trapped holes in pristine and surface-passivated FA
0.99
Cs
0.01
PbI
3
devices using a combination of quasi-steady-state and nanosecond time-resolved pump-push-photocurrent, as well as kinetic and drift-diffusion models. We find a two-step trap-filling process: the rapid filling (~10 ns) of low-density traps in the bulk of perovskite, followed by the slower filling (~100 ns) of high-density traps at the perovskite/hole transport material interface. Surface passivation by n-octylammonium iodide dramatically reduces the number of trap states (~50 times), improving the device performance substantially. Moreover, the activation energy (~280 meV) of the dominant hole traps remains similar with and without surface passivation.
The atomic nucleus and its electrons are often thought of as independent systems that are held together in the atom by their mutual attraction. Their interaction, however, leads to other important ...effects, such as providing an additional decay mode for excited nuclear states, whereby the nucleus releases energy by ejecting an atomic electron instead of by emitting a γ-ray. This 'internal conversion' has been known for about a hundred years and can be used to study nuclei and their interaction with their electrons. In the inverse process-nuclear excitation by electron capture (NEEC)-a free electron is captured into an atomic vacancy and can excite the nucleus to a higher-energy state, provided that the kinetic energy of the free electron plus the magnitude of its binding energy once captured matches the nuclear energy difference between the two states. NEEC was predicted in 1976 and has not hitherto been observed. Here we report evidence of NEEC in molybdenum-93 and determine the probability and cross-section for the process in a beam-based experimental scenario. Our results provide a standard for the assessment of theoretical models relevant to NEEC, which predict cross-sections that span many orders of magnitude. The greatest practical effect of the NEEC process may be on the survival of nuclei in stellar environments, in which it could excite isomers (that is, long-lived nuclear states) to shorter-lived states. Such excitations may reduce the abundance of the isotope after its production. This is an example of 'isomer depletion', which has been investigated previously through other reactions, but is used here to obtain evidence for NEEC.
Bupropion is indicated to promote smoking cessation. Animal studies suggest that the pharmacologic activity of bupropion can be mediated by its major metabolite, hydroxybupropion. We measured plasma ...bupropion and its metabolite levels in a double‐blind, placebo controlled, randomized smoking‐cessation trial. Among the treatment‐adherent individuals, higher hydroxybupropion concentrations (per μg/ml) resulted in better smoking‐cessation outcomes (week 3, 7, and 26 odds ratio (OR) = 2.82, 2.96, and 2.37, respectively, P = 0.005–0.040); this was not observed with bupropion levels (OR = 1.00–1.03, P = 0.59–0.90). Genetic variation in CYP2B6, the enzyme that metabolizes bupropion to hydroxybupropion, was identified as a significant source of variability in hydroxybupropion formation. Our data indicate that hydroxybupropion contributes to the pharmacologic effects of bupropion for smoking cessation, and that variability in response to bupropion treatment is related to variability in CYP2B6‐mediated hydroxybupropion formation. These findings suggest that dosing of bupropion to achieve a hydroxybupropion level of 0.7 μg/ml or increasing bupropion dose for CYP2B6 slow metabolizers could improve bupropion's cessation outcomes.
Clinical Pharmacology & Therapeutics (2012); 92 6, 771–777. doi:10.1038/clpt.2012.186
The population structure of Phytophthora infestans in China was studied and three mitochondrial haplotypes (Ia, IIa, IIb) were observed. Genetic analysis with 10 highly informative SSR markers ...identified 68 different genotypes, including three dominant clonal lineages. In the Chinese P. infestans population, the genotypes were strongly clustered according to their geographic origin. One of dominant clonal lineages was genetically similar to Blue_13, a dominant clonal lineage found in Europe since 2004. This is the first report of Blue_13 outside Europe. Only one mating type (A1) was found in the northern and southeastern provinces, but in southern and northwestern China both mating types were observed. The mating type ratio and SSR allele frequencies indicate that in China the sexual cycle of P. infestans is rare. These results emphasize that the migration of asexual propagules and the generation of subclonal variation are the dominant driving factors of the population structure of P. infestans in China. They may also have implications for the role of monitoring P. infestans populations in potato late blight management strategies in China.
Arrays of well‐aligned, ca. 4.7 mm long carbon nanotubes (CNTs) are grown in a simple, safe, and cost‐effective manner using an efficient Al2O3/Fe catalyst prepared by an ion‐beam assisted deposition ...technique (see figure). Importantly, the as‐synthesized CNT arrays with lengths ranging from 500 μm to 1.5 mm are conducive to spinning, and CNT fibers spun from such long CNT arrays show remarkably improved tensile strength.
The coronavirus family member, SARS-CoV-2 has been identified as the causal agent for the pandemic viral pneumonia disease, COVID-19. At this time, no vaccine is available to control further ...dissemination of the disease. We have previously engineered a synthetic DNA vaccine targeting the MERS coronavirus Spike (S) protein, the major surface antigen of coronaviruses, which is currently in clinical study. Here we build on this prior experience to generate a synthetic DNA-based vaccine candidate targeting SARS-CoV-2 S protein. The engineered construct, INO-4800, results in robust expression of the S protein in vitro. Following immunization of mice and guinea pigs with INO-4800 we measure antigen-specific T cell responses, functional antibodies which neutralize the SARS-CoV-2 infection and block Spike protein binding to the ACE2 receptor, and biodistribution of SARS-CoV-2 targeting antibodies to the lungs. This preliminary dataset identifies INO-4800 as a potential COVID-19 vaccine candidate, supporting further translational study.
Aim
The intestinal barrier is made up of epithelial cells and intercellular junctional complexes to regulate epithelial ion transport and permeability. Dopamine (DA) is able to promote duodenal ...epithelial ion transport through D1‐like receptors, which includes subtypes of D1 (D1R) and D5 (D5R), but whether D1‐like receptors influence the duodenal permeability is unclear.
Methods
FITC–dextran permeability, short‐circuit current (ISC), Western blot, immunohistochemistry and ELISA were used in human D5R transgenic mice and hyperendogenous enteric DA (HEnD) rats in this study.
Results
Dopamine induced a downward deflection in ISC and an increase in FITC–dextran permeability of control rat duodenum, which were inhibited by the D1‐like receptor antagonist, SCH‐23390. However, DA decreased duodenal transepithelial resistance (TER), an effect also reversed by SCH‐23390. A strong immunofluorescence signal for D5R, but not D1R, was observed in the duodenum of control rat. In human D5R knock‐in transgenic mice, duodenal mucosa displayed an increased basal ISC with high FITC–dextran permeability and decreased TER with a lowered expression of tight junction proteins, suggesting attenuated duodenal barrier function in these transgenic mice. D5R knock‐down transgenic mice manifested a decreased basal ISC with lowered FITC–dextran permeability. Moreover, an increased FITC–dextran permeability combined with decreased TER and tight junction protein expression in duodenal mucosa were also observed in HEnD rats.
Conclusion
This study demonstrates, for the first time, that DA enhances duodenal permeability of control rat via D5R, which provides new experimental and theoretical evidence for the influence of DA on duodenal epithelial barrier function.
Summary Background Insulin-like growth factors (IGF-1 and IGF-2) bind to the IGF-1 receptor (IGF-1R), increasing cell proliferation and survival. Ganitumab is a monoclonal IgG1 antibody that blocks ...IGF-1R. We tested the efficacy and safety of adding ganitumab to endocrine treatment for patients with hormone-receptor-positive breast cancer. Methods We did this phase 2 trial in outpatient clinics and hospitals. We enrolled postmenopausal women with hormone-receptor-positive, locally advanced or metastatic breast cancer previously treated with endocrine treatment. They were randomly assigned (2:1) with a central randomisation schedule to receive intravenous ganitumab 12 mg per kg bodyweight or placebo in combination with open-label intramuscular fulvestrant (500 mg on day 1, then 250 mg on days 15, 29, and every 28 days) or oral exemestane (25 mg once daily) on a 28-day cycle. Patients, investigators, study monitors, and the sponsor staff were masked to treatment allocation. Response was assessed every 8 weeks. The primary endpoint was median progression-free survival in the intention-to-treat population. We analysed overall survival as one of our secondary endpoints. The study is registered at ClinicalTrials.gov , number NCT00626106. Findings We screened 189 patients and enrolled 156 (106 in the ganitumab group and 50 in the placebo group). Median progression-free survival did not differ significantly between the ganitumab and placebo groups (3·9 months, 80% CI 3·6–5·3 vs 5·7 months, 4·4–7·4; hazard ratio HR 1·17, 80% CI 0·91–1·50; p=0·44). However, overall survival was worse in the the ganitumab group than in the placebo group (HR 1·78, 80% CI 1·27–2·50; p=0·025). With the exception of hyperglycaemia, adverse events were generally similar between groups. The most common grade 3 or higher adverse event was neutropenia—reported by six of 106 (6%) patients in the ganitumab group and one of 49 (2%) in the placebo group. Hyperglycaemia was reported by 12 of 106 (11%) patients in the ganitumab group (with six patients having grade 3 or 4 hyperglycaemia) and none of 49 in the placebo group. Serious adverse events were reported by 27 of 106 (25%) patients in the ganitumab group and nine of 49 (18%) patients in the placebo group. Interpretation Addition of ganitumab to endocrine treatment in women with previously treated hormone-receptor-positive locally advanced or metastatic breast cancer did not improve outcomes. Our results do not support further study of ganitumab in this subgroup of patients. Funding Amgen.
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