Symmetry-forbidden intervalley scattering by atomic defects in monolayer transition-metal dichalcogenides

Intervalley scattering by atomic defects in monolayer transition metal dichalcogenides (TDMs; MX2) presents a serious obstacle for applications exploiting their unique valley-contrasting properties. Here, we show that the symmetry of the atomic defects can give rise to an unconventional protection mechanism against intervalley scattering in monolayer TMDs. The predicted defect-dependent selection rules for intervalley scattering can be verified via Fourier transform scanning tunneling spectroscopy (FT-STS), and provide a unique identification of, e.g., atomic vacancy defects (M vs X). Our findings put the absence of the intervalley FT-STS peak in recent experiments in a different perspective.Comment: 7 pages, 4 figures + supplementary. Published versio

Systematic feature variation underlies adults’ and children’s use of in and on

The spatial prepositions in and on apply to a wide range ofcontainment and support relations, making exhaustivedefinitions difficult. Theories differ in whether they endorsegeometric or functional properties and how these properties arerelated to meaning and use. This study directly examines theroles of geometric and functional information in adults’ andchildren’s use of in and on by developing a large sample ofrelations situated within a small gradable geometric andfunctional feature space. We propose that variation in featuresacross items is systematically related to the use of in and onand demonstrate that feature-language relationships changeacross development: adults’ expression use is sensitive to bothgeometric and functional features, while children’s use variesonly according to geometric features

Geometric and functional knowledge in the acquisition of spatial language

Considerable debate surrounds the nature of spatial categories, beginning with the observation that all languages use a limited and closed set of terms to encode object location and what appears to be a large and diverse set of object relations and configurations (Talmy, 1985). In previous work, Johannes, Landau and colleagues (Johannes, Wilson, & Landau, 2012, submitted; Landau, Johannes, Skordos, & Papafragou, under review) proposed that the structure of the conceptual categories of Containment and Support that underlie spatial language is reflected in the probabilistic use of spatial terms like in and on. The work in this thesis expands on these earlier findings by exploring the nature of the conceptual information underlying probabilistic spatial expression use and the relationship between conceptual knowledge and spatial expression use across development. The studies probe relationships between adults' and children's spatial expression use and a small set of geometric features, derived from studies of pre-linguistic spatial cognition knowledge (Hespos & Baillargeon, 2001, 2008; Hespos & Spelke, 2004, 2007), and a functional feature, Locational Control, adapted from psycholinguistic studies of in and on (Garrod, Ferrier, & Campbell, 1999). The results of three studies show that adults' and children's use of different types of spatial expressions (including BE + in(side)/on (top) and lexical verbs) for a large and diverse set of Containment and Support items are predicted by different combinations of geometric and functional features. Geometric features show consistent relationships to expression use across development, while Locational Control differs in its relationship to adults' and children's use of different expression types. Parents of 4- and 6-year-old participants also provided estimates of how likely they were to use different expression types to describe the same set of experimental items to their children. Including these estimates, alongside features, in models of child expression use improved the accuracy of model predictions, particularly for children’s use of lexical verb expressions, which initially showed weak relationships to feature ratings. These findings are among the first to account for spatial language usage and development as a complex function of spatial (geometric and functional) knowledge and input environment and the first to systematically examine spatial encoding for such a diverse sample of items that are representative of the everyday object configurations that children and adults encounter in the world

Comparison of CT, PET, and PET/CT for Staging of Patients with Indolent Non-Hodgkin’s Lymphoma

The aim was to investigate the potential impact of positron emission tomography (PET)/computed tomography (CT) as compared to PET and CT on the staging of patients with indolent lymphoma. PET/CTs from 45 patients with indolent lymphoma undergoing staging or restaging were studied. Clinical follow-up, additional imaging, and histology served as the gold standard. PET/CT correctly diagnosed 92 nodal regions as positive for lymphomatous involvement and 458 as disease free vs 68 and 449 for PET and 64 and 459 for CT, respectively. The respective sensitivities, specificities, and accuracies were 99%, 100%, and 99.8% for PET/CT, 68%, 97.5%, and 92.2% for PET, and 70%, 100%, and 94.7% for CT. PET/CT performed significantly better than PET (p < 0.001 for sensitivity, specificity, and accuracy) and CT (p < 0.001 for sensitivity and accuracy). PET/CT also correctly identified significantly more extra-nodal lesions (22) than CT (14) and PET (nine). PET/CT provides significantly more accurate information compared to PET and CT for the staging and re-staging of patients with indolent lymphoma

Ventricular-vascular coupling is predictive of adverse clinical outcome in paediatric pulmonary arterial hypertension

AIMS: Ventricular-vascular coupling, the ratio between the right ventricle's contractile state (Ees) and its afterload (Ea), may be a useful metric in the management of paediatric pulmonary arterial hypertension (PAH). In this study we assess the prognostic capacity of the ventricular-vascular coupling ratio (Ees/Ea) derived using right ventricular (RV) pressure alone in children with PAH. METHODS: One hundred and thirty paediatric patients who were diagnosed with PAH via right heart catheterisation were retrospectively reviewed over a 10-year period. Maximum RV isovolumic pressure and end-systolic pressure were estimated using two single-beat methods from Takeuchi et al (Ees/Ea_(Takeuchi)) and from Kind et al (Ees/Ea_(Kind)) and used with an estimate of end-systolic pressure to compute ventricular-vascular coupling from pressure alone. Patients were identified as either idiopathic/hereditary PAH or associated PAH (IPAH/HPAH and APAH, respectively). Haemodynamic data, clinical functional class and clinical worsening outcomes-separated into soft (mild) and hard (severe) event categories-were assessed. Adverse soft events included functional class worsening, syncopal event, hospitalisation due to a proportional hazard-related event and haemoptysis. Hard events included death, transplantation, initiation of prostanoid therapy and hospitalisation for atrial septostomy and Pott's shunt. Cox proportional hazard modelling was used to assess whether Ees/Ea was predictive of time-to-event. RESULTS: In patients with IPAH/HPAH, Ees/Ea_(Kind) and Ees/Ea_(Takeuchi) were both independently associated with time to hard event (p=0.003 and p=0.001, respectively) and when adjusted for indexed pulmonary vascular resistance (p=0.032 and p=0.013, respectively). Neither Ees/Ea_(Kind) nor Ees/Ea_(Takeuchi) were associated with time to soft event. In patients with APAH, neither Ees/Ea_(Kind) nor Ees/Ea_(Takeuchi) were associated with time to hard event or soft event. CONCLUSIONS: Ees/Ea derived from pressure alone is a strong independent predictor of adverse outcome and could be a potential powerful prognostic tool for paediatric PAH

Engineering HIV envelope protein to activate germline B cell receptors of broadly neutralizing anti-CD4 binding site antibodies

Broadly neutralizing antibodies (bnAbs) against HIV are believed to be a critical component of the protective responses elicited by an effective HIV vaccine. Neutralizing antibodies against the evolutionarily conserved CD4-binding site (CD4-BS) on the HIV envelope glycoprotein (Env) are capable of inhibiting infection of diverse HIV strains, and have been isolated from HIV-infected individuals. Despite the presence of anti–CD4-BS broadly neutralizing antibody (bnAb) epitopes on recombinant Env, Env immunization has so far failed to elicit such antibodies. Here, we show that Env immunogens fail to engage the germline-reverted forms of known bnAbs that target the CD4-BS. However, we found that the elimination of a conserved glycosylation site located in Loop D and two glycosylation sites located in variable region 5 of Env allows Env-binding to, and activation of, B cells expressing the germline-reverted BCRs of two potent broadly neutralizing antibodies, VRC01 and NIH45-46. Our results offer a possible explanation as to why Env immunogens have been ineffective in stimulating the production of such bNAbs. Importantly, they provide key information as to how such immunogens can be engineered to initiate the process of antibody-affinity maturation against one of the most conserved Env regions

Prognostic value of novel imaging parameters derived from standard cardiovascular magnetic resonance in high risk patients with systemic light chain amyloidosis

Background: The differentiated assessment of functional parameters besides morphological changes is essential for the evaluation of prognosis in systemic immunoglobulin light chain (AL) amyloidosis. Methods: Seventy-four subjects with AL amyloidosis and presence of late gadolinium enhancement (LGE) pattern typical for cardiac amyloidosis were analyzed. Long axis strain (LAS) and myocardial contraction fraction (MCF), as well as morphological and functional markers, were measured. The primary endpoint was death, while death and heart transplantation served as a composite secondary endpoint. Results: After a median follow-up of 41 months, 29 out of 74 patients died and 10 received a heart transplant. Left ventricular (LV) functional parameters were reduced in patients, who met the composite endpoint (LV ejection fraction 51% vs. 61%, LAS − 6.9% vs − 10%, GLS − 12% vs − 15% and MCF 42% vs. 69%; p <  0.001 for all). In unadjusted univariate analysis, LAS (HR = 1.05, p <  0.001) and MCF (HR = 0.96, p <  0.001) were associated with reduced transplant-free survival. Kaplan-Meier analyses showed a significantly lower event-free survival in patients with reduced MCF. MCF and LAS performed best to identify high risk patients for secondary endpoint (Log-rank test p <  0.001) in a combined model. Using sequential Cox regression analysis, the addition of LAS and MCF to LV ejection fraction led to a significant increase in the predictive power of the model (χ2 (df = 1) = 28.2, p <  0.001). Conclusions: LAS and MCF as routinely available and robust CMR-derived parameters predict outcome in LGE positive AL amyloidosis. Patients with impaired LV function in combination with reduced LAS and MCF are at the highest risk for death and heart transplantation