Andreev Reflections in Micrometer-Scale Normal-Insulator-Superconductor Tunnel Junctions

Understanding the subgap behavior of Normal-Insulator-Superconductor (NIS) tunnel junctions is important in order to be able to accurately model the thermal properties of the junctions. Hekking and Nazarov developed a theory in which NIS subgap current in thin-film structures can be modeled by multiple Andreev reflections. In their theory, the current due to Andreev reflections depends on the junction area and the junction resistance area product. We have measured the current due to Andreev reflections in NIS tunnel junctions for various junction sizes and junction resistance area products and found that the multiple reflection theory is in agreement with our data

Production Mechanism for Quark Gluon Plasma in Heavy Ion Collisions

A general scheme is proposed here to describe the production of semi soft and soft quarks and gluons that form the bulk of the plasma in ultra relativistic heavy ion collisions. We show how to obtain rates as a function of time in a self consistent manner, without any ad-hoc assumption. All the required features - the dynamical nature of QCD vacuum, the non-Markovian nature of the production, and quasi particle nature of the partons, and the importance of quantum interference effects are naturally incorporated. We illustrate the results with a realistic albeit toy model and show how almost all the currently employed source terms are unreliable in their predictions. We show the rates in the momentum space and indicate at the end how to extract the full phase-space dependence.Comment: 4 pages, 4 figures, two colum

Comprehensive Genomic Profiling in Routine Clinical Practice Leads to a Low Rate of Benefit from Genotype-Directed Therapy

Background: Describe a single-center real-world experience with comprehensive genomic profiling (CGP) to identify genotype directed therapy (GDT) options for patients with malignancies refractory to standard treatment options. Methods: Patients who had CGP by a CLIA-certified laboratory between November 2012 and December 2015 were included. The medical records were analyzed retrospectively after Institutional Review Board (IRB) approval. The treating oncologist made the decision to obtain the assay to provide potential therapeutic options. The objectives of this study were to determine the proportion of patients who benefited from GDT, and to identify barriers to receiving GDT. Results: A total of 125 pediatric and adult patients with a histologically confirmed diagnosis of malignancy were included. Among these, 106 samples were from adult patients, and 19 samples were from pediatric patients. The median age was 54 years for adults. The majority had stage IV malignancy (53%) and were pretreated with 2–3 lines of therapy (45%). The median age was 8 years for pediatric patients. The majority had brain tumors (47%) and had received none or 1 line of therapy (58%) when the profiling was requested. A total of 111 (92%) patients had genomic alterations and were candidates for GDT either via on/off-label use or a clinical trial (phase 1 through 3). Fifteen patients (12%) received GDT based on these results including two patients who were referred for genomically matched phase 1 clinical trials. Three patients (2%) derived benefit from their GDT that ranged from 2 to 6 months of stable disease. Conclusions: CGP revealed potential treatment options in the majority of patients profiled. However, multiple barriers to therapy were identified, and only a small minority of the patients derived benefit from GDT

A Study of Brain Networks Associated with Swallowing Using Graph-Theoretical Approaches

Functional connectivity between brain regions during swallowing tasks is still not well understood. Understanding these complex interactions is of great interest from both a scientific and a clinical perspective. In this study, functional magnetic resonance imaging (fMRI) was utilized to study brain functional networks during voluntary saliva swallowing in twenty-two adult healthy subjects (all females, 23.1±1.52 years of age). To construct these functional connections, we computed mean partial correlation matrices over ninety brain regions for each participant. Two regions were determined to be functionally connected if their correlation was above a certain threshold. These correlation matrices were then analyzed using graph-theoretical approaches. In particular, we considered several network measures for the whole brain and for swallowing-related brain regions. The results have shown that significant pairwise functional connections were, mostly, either local and intra-hemispheric or symmetrically inter-hemispheric. Furthermore, we showed that all human brain functional network, although varying in some degree, had typical small-world properties as compared to regular networks and random networks. These properties allow information transfer within the network at a relatively high efficiency. Swallowing-related brain regions also had higher values for some of the network measures in comparison to when these measures were calculated for the whole brain. The current results warrant further investigation of graph-theoretical approaches as a potential tool for understanding the neural basis of dysphagia. © 2013 Luan et al

Simple model of adsorption on external surface of carbon nanotubes: a new analytical approach basing on molecular simulation data

Nitrogen adsorption on carbon nanotubes is wide- ly studied because nitrogen adsorption isotherm measurement is a standard method applied for porosity characterization. A further reason is that carbon nanotubes are potential adsorbents for separation of nitrogen from oxygen in air. The study presented here describes the results of GCMC simulations of nitrogen (three site model) adsorption on single and multi walled closed nanotubes. The results obtained are described by a new adsorption isotherm model proposed in this study. The model can be treated as the tube analogue of the GAB isotherm taking into account the lateral adsorbate-adsorbate interactions. We show that the model describes the simulated data satisfactorily. Next this new approach is applied for a description of experimental data measured on different commercially available (and characterized using HRTEM) carbon nanotubes. We show that generally a quite good fit is observed and therefore it is suggested that the observed mechanism of adsorption in the studied materials is mainly determined by adsorption on tubes separated at large distances, so the tubes behave almost independently

A Multicenter, Phase 2 Study of Vascular Endothelial Growth Factor Trap (Aflibercept) in Platinum- and Erlotinib-Resistant Adenocarcinoma of the Lung

IntroductionAflibercept (vascular endothelial growth factor [VEGF] trap), a recombinant fusion protein, blocks the activity of VEGF-A and placental growth factor and has demonstrated activity in pretreated patients with lung cancer in a phase I trial. This study evaluated the efficacy and safety of intravenous aflibercept in patients with platinum- and erlotinib-resistant lung adenocarcinoma.MethodsAn open-label, single arm, multicenter trial was conducted, with the primary end point of response rate (modified RECIST). Additional endpoints included safety, duration of response, progression-free survival, and overall survival. Patients with platinum- and erlotinib-resistant lung adenocarcinoma were eligible. Aflibercept 4.0 mg/kg intravenous every 2 weeks was administered until progression of disease or intolerable toxicity.ResultsNinety-eight patients were enrolled; 89 were evaluable for response. Median age was 60 years, 41% were men with Eastern Cooperative Oncology Group performance status 0/1/2 in 35/55/9% of patients. The overall response rate was 2.0%, (95% confidence interval, 0.2-7.2%). Median progression-free survival was 2.7 months, and overall was survival 6.2 months. Six- and 12-month survival rates were 54 and 29%, respectively. A median of four cycles was administered (range 1-22). Common grade 3/4 toxicities included dyspnea (21%), hypertension (23%), and proteinuria (10%). Two cases of grade 5 hemoptysis were reported, and one case each of tracheoesophageal fistula, decreased cardiac ejection fraction, cerebral ischemia, and reversible posterior leukoencephalopathy.ConclusionsAflibercept has minor single agent activity in heavily pretreated lung adenocarcinoma, and is well tolerated, with no unexpected toxicities. Further studies evaluating aflibercept in lung cancer, in combination with chemotherapy and other targeted therapies, are ongoing

Prepatterning in the Stem Cell Compartment

The mechanism by which an apparently uniform population of cells can generate a heterogeneous population of differentiated derivatives is a fundamental aspect of pluripotent and multipotent stem cell behaviour. One possibility is that the environment and the differentiation cues to which the cells are exposed are not uniform. An alternative, but not mutually exclusive possibility is that the observed heterogeneity arises from the stem cells themselves through the existence of different interconvertible substates that pre-exist before the cells commit to differentiate. We have tested this hypothesis in the case of apparently homogeneous pluripotent human embryonal carcinoma (EC) stem cells, which do not follow a uniform pattern of differentiation when exposed to retinoic acid. Instead, they produce differentiated progeny that include both neuronal and non-neural phenotypes. Our results suggest that pluripotent NTERA2 stem cells oscillate between functionally distinct substates that are primed to select distinct lineages when differentiation is induced