A Label-Free and Ultrasensitive Immunosensor for Detection of Human Chorionic Gonadotrophin Based on Graphene FETs.

We report on a label-free immunosensor based on graphene field effect transistors (G-FETs) for the ultrasensitive detection of Human Chorionic Gonadotrophin (hCG), as an indicator of pregnancy and related disorders, such as actopic pregnancy, choriocarcinoma and orchic teratoma. Pyrene based bioactive ester was non-covalently anchored onto the graphene channel in order to retain the sp² lattice. The G-FET transfer characteristics showed repeatable and reliable responses in all surface modifying steps using a direct current (DC) readout system. The hCG concentration gradient showed a detection limit of ~1 pg·mL-1. The proposed method facilitates the cost-effective and viable production of graphene point-of-care devices for clinical diagnosis

Improved efficiency of graphene/Si Schottky junction solar cell based on back contact structure and DUV treatment

© 2017 Elsevier Ltd A graphene/Si Schottky junction solar cell is commonly fabricated by using the top-window structure. However, reported devices have many drawbacks such as a small active area of 0.11 cm 2 , s-shape in the J-V curves, recombination process of charge carriers at the graphene/textured Si interface, high cost and a complex fabrication process. Here, we report a novel graphene/Si Schottky junction solar cell with a back contact-structure, which has benefits of a simpler fabrication process, lower fabrication cost, and larger active area in comparison with a device fabricated with the previous structure. Additionally, we found that the PMMA residue left on graphene surfaces is the key to eliminate the s-shape in the J-V curves. Thus, the deep UV treatment of the CVD graphene is applied within the wet transfer process to effectively remove the PMMA residue, suppress the behavior of s-shaped kink in J-V curves and enhance the solar cell efficiency. As a result, the recorded power conversion efficiency of 10% is achieved for graphene/textured Si devices without chemical doping and anti-reflection coating, and this value is improved to 14.1% after applying chemical doping. Doped devices also show great stability and retain 84% of the efficiency after 9 days storage in air

Quantitative Analysis of Cell Nucleus Organisation

There are almost 1,300 entries for higher eukaryotes in the Nuclear Protein Database. The proteins' subcellular distribution patterns within interphase nuclei can be complex, ranging from diffuse to punctate or microspeckled, yet they all work together in a coordinated and controlled manner within the three-dimensional confines of the nuclear volume. In this review we describe recent advances in the use of quantitative methods to understand nuclear spatial organisation and discuss some of the practical applications resulting from this work

The Transcriptional Regulator CBP Has Defined Spatial Associations within Interphase Nuclei

It is becoming increasingly clear that nuclear macromolecules and macromolecular complexes are compartmentalized through binding interactions into an apparent three-dimensionally ordered structure. This ordering, however, does not appear to be deterministic to the extent that chromatin and nonchromatin structures maintain a strict 3-D arrangement. Rather, spatial ordering within the cell nucleus appears to conform to stochastic rather than deterministic spatial relationships. The stochastic nature of organization becomes particularly problematic when any attempt is made to describe the spatial relationship between proteins involved in the regulation of the genome. The CREB–binding protein (CBP) is one such transcriptional regulator that, when visualised by confocal microscopy, reveals a highly punctate staining pattern comprising several hundred individual foci distributed within the nuclear volume. Markers for euchromatic sequences have similar patterns. Surprisingly, in most cases, the predicted one-to-one relationship between transcription factor and chromatin sequence is not observed. Consequently, to understand whether spatial relationships that are not coincident are nonrandom and potentially biologically important, it is necessary to develop statistical approaches. In this study, we report on the development of such an approach and apply it to understanding the role of CBP in mediating chromatin modification and transcriptional regulation. We have used nearest-neighbor distance measurements and probability analyses to study the spatial relationship between CBP and other nuclear subcompartments enriched in transcription factors, chromatin, and splicing factors. Our results demonstrate that CBP has an order of spatial association with other nuclear subcompartments. We observe closer associations between CBP and RNA polymerase II–enriched foci and SC35 speckles than nascent RNA or specific acetylated histones. Furthermore, we find that CBP has a significantly higher probability of being close to its known in vivo substrate histone H4 lysine 5 compared with the closely related H4 lysine 12. This study demonstrates that complex relationships not described by colocalization exist in the interphase nucleus and can be characterized and quantified. The subnuclear distribution of CBP is difficult to reconcile with a model where chromatin organization is the sole determinant of the nuclear organization of proteins that regulate transcription but is consistent with a close link between spatial associations and nuclear functions

Non-linear dynamic analysis of coupled spar platform

Spar platforms are treated as cost-effective and resourceful type of offshore structure in deep water. With increasing depth there are significant changes in its structural behaviour due to coupling of spar hull-mooring line along with radical influence of mooring line damping. So these phenomena should be precisely counted for accurate motion analysis of spar mooring system. In present study, spar platform are configured as a single fully coupled integrated model in ABAQUS/AQUA. Non-linear dynamic analysis in time domain is performed adopting Newmark-β automatic time incrementation technique. Non-linearities due to geometric, loading and boundary conditions are duly considered. Displacement and rotational responses of spar and mooring tensions are obtained during long-duration storm. spar responses get significantly modified and mean position of oscillations gets shifted after longer wave loading. The surge, heave and pitch responses are predominantly excited respectively. The energy contents of PSDs of these responses reduce considerably after long wave loading. Mooring tension responses are significantly different reflecting the damping effect of mooring lines. The pitch response is fairly sensitive to the wave loading duration. After long duration of storm the wave frequency response increases. However, low frequency and wave frequency responses may simultaneously occur due to synchronising sea states

Structural behaviour of fully coupled spar–mooring system under extreme wave loading

Floating spar platform has been proven to be an economical and efficient type of offshore oil and gas exploration structure in deep and ultra-deep seas. Associated nonlinearities, coupled action, damping effect and extreme sea environments may modify its structural responses. In this study, fully coupled spar–mooring system is modelled integrating mooring lines with the cylindrical spar hull. Rigid beam element simulates large cylindrical spar hull and catenary mooring lines are configured by hybrid beam elements. Nonlinear finite element analysis is performed under extreme wave loading at severe deep sea. Morison's equation has been used to calculate the wave forces. Spar responses and mooring line tensions have been evaluated. Though the maximum mooring line tensions are larger at severe sea-state, it becomes regular after one hour of wave loading. The response time histories in surge, heave, pitch and the maximum mooring tension gradually decreases even after attaining steady state. It is because of damping due to heavier and longer mooring lines in coupled spar–mooring system under deep water conditions. The relatively lesser values of response time histories in surge, heave, pitch and the maximum mooring tension under extreme wave loading shows the suitability of a spar platform for deep water harsh and uncertain environmental conditions

Demystifying Smoker's Paradox: A Propensity Score-Weighted Analysis in Patients Hospitalized With Acute Heart Failure.

Background Smoker's paradox has been observed with several vascular disorders, yet there are limited data in patients with acute heart failure (HF). We examined the effects of smoking in patients with acute HF using data from a large multicenter registry. The objective was to determine if the design and analytic approach could explain the smoker's paradox in acute HF mortality. Methods and Results The data were sourced from the acute HF registry (Gulf CARE [Gulf Acute Heart Failure Registry]), a multicenter registry that recruited patients over 10 months admitted with a diagnosis of acute HF from 47 hospitals in 7 Middle Eastern countries. The association between smoking and mortality (in hospital) was examined using covariate adjustment, making use of mortality risk factors. A parallel analysis was performed using covariate balancing through propensity scores. Of 5005 patients hospitalized with acute HF, 1103 (22%) were current smokers. The in-hospital mortality rates were significantly lower in current smoker's before (odds ratio, 0.71; 95% CI, 0.52-0.96) and more so after (odds ratio, 0.47; 95% CI, 0.31-0.70) covariate adjustment. With the propensity score-derived covariate balance, the smoking effect became much less certain (odds ratio, 0.63; 95% CI, 0.36-1.11). Conclusions The current study illustrates the fact that the smoker's paradox is likely to be a result of residual confounding as covariate adjustment may not resolve this if there are many competing prognostic confounders. In this situation, propensity score methods for covariate balancing seem preferable. Clinical Trial Registration URL: https://www.clinicaltrials.gov/. Unique identifier: NCT01467973.Gulf CARE (Gulf Acute Heart Failure Registry) is an investigator- initiated study conducted under the auspices of the Gulf Heart Association and funded by Servier, Paris, France; and (for centers in Saudi Arabia), by the Saudi Heart Association (The Deanship of Scientific Research at King Saud University, Riyadh, Saudi Arabia [research group number: RG -1436- 013]). This does not alter our adherence to policies on sharing data and materials; and the funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. The publication of this article was funded by the Qatar National Library