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#32745881   2020/07/29 To Up

3D characterisation using plasma FIB-SEM: A large-area tomography technique for complex surfaces like black silicon.

This paper demonstrates an improved method to accurately extract the surface morphology of black silicon (BSi). The method is based on an automated Xe plasma focused ion beam (PFIB) and scanning electron microscope (SEM) tomography technique. A comprehensive new sample preparation method is described and shown to minimize the PFIB artifacts induced by both the top surface sample-PFIB interaction and the non-uniform material density. An optimized post-image processing procedure is also described that ensures the accuracy of the reconstructed 3D surface model. The application of these new methods is demonstrated by applying them to extract the surface topography of BSi formed by reactive ion etching (RIE) consisting of 2 µm tall needles. An area of 320 µm is investigated with a controlled slice thickness of 10 nm. The reconstructed 3D model allows the extraction of critical roughness characteristics, such as height distribution, correlation length, and surface enhancement ratio. Furthermore, it is demonstrated that the particular surface studied contains regions in which under-etching has resulted in overhanging structures, which would not have been identified with other surface topography techniques. Such overhanging structures can be present in a broad range of BSi surfaces, including BSi surfaces formed by RIE and metal catalyst chemical etching (MCCE). Without proper measurement, the un-detected overhangs would result in the underestimation of many critical surface characteristics, such as absolute surface area, electrochemical reactivity and light-trapping.
Yu Zhang, Charlie Kong, Rasmus Schmidt Davidsen, Giuseppe Scardera, Leiping Duan, Kean Thong Khoo, David N R Payne, Bram Hoex, Malcolm Abbott

1124 related Products with: 3D characterisation using plasma FIB-SEM: A large-area tomography technique for complex surfaces like black silicon.

96T1 ml100μg0.1ml (1mg/ml)1 kit(96 Wells)5 mg100 ul 5 G0.25 mg

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#32745569   2020/07/31 To Up

Autoantibody detection for diagnosis in direct immunofluorescence negative mucous membrane pemphigoid: ocular and other sites compared.

To assess whether a panel of serum pemphigoid autoantibody tests could be used to confirm an immunopathological diagnosis of mucous membrane pemphigoid (MMP) in direct immunofluorescent negative (DIF-) MMP patients.
John Dart, Jane Setterfield, Richard W Groves, John B Mee, Gilles F H Diercks, Hendri H Pas, Darwin Minassian,

2830 related Products with: Autoantibody detection for diagnosis in direct immunofluorescence negative mucous membrane pemphigoid: ocular and other sites compared.

4 Membranes/Box4 Membranes/Box500 MG4 Membranes/Box4 Membranes/Box250 mg4 Membranes/Box1000 pcs4 Membranes/Box2 Pieces/Box

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#32745477   2020/07/31 To Up

Leveraging parasympathetic nervous system activity to study risk for psychopathology: The special case of callous-unemotional traits.

Callous-unemotional (CU) traits are implicated in the development of severe and persistent antisocial behavior, and appear to arise from distinct behavioral, temperament, physiological, and neural risk factors to other types of externalizing psychopathology. Although existing etiological models have attempted to characterize specific mechanisms underlying the emergence of CU traits, prior empirical work is plagued by a host of inconsistent results. This inconsistency is particularly apparent in research that has investigated variation in physiological functioning, arousal, and reactivity. In this review, we summarize and evaluate studies that have examined the role of parasympathetic nervous system (PNS) functioning in child psychopathology, including studies of CU traits. We argue that the inclusion of measures of PNS activity can significantly enhance our understanding of the etiology of CU traits, provide clarity to the inconsistent findings of prior studies, and advance mechanistically-targeted interventions and treatments. We conclude the review by providing foundational and testable hypotheses about the role that disrupted PNS functioning could play in multiple pathways to CU traits beginning in infancy and across development.
Nicholas J Wagner, Rebecca Waller

1932 related Products with: Leveraging parasympathetic nervous system activity to study risk for psychopathology: The special case of callous-unemotional traits.

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#32744875   2020/08/03 To Up

Isotopic characterisation and dating of groundwater recharge mechanisms in crystalline fractured aquifers: example of the semi-arid Banabuiú watershed (Brazil).

Sustainable groundwater management implies a good knowledge of recharge processes, especially in areas with water deficit, like the semi-arid region of Banabuiú watershed (Ceará State, Northeast of Brazil). In this zone, phreatic aquifers consist of Precambrian crystalline fractured reservoirs characterised by a high spatial anisotropy, both in terms of hydrodynamics and water quality. This study implemented a multi-tracer approach (O, H, C, H, CFC, SF), combined with hydrodynamic data (i.e. groundwater levels) to identify the groundwater recharge origin and the recharge mechanisms, and to estimate the groundwater residence time. At the basin scale, hydrodynamic data and local observations indicated the high reactivity of aquifers to precipitation and suggested that infiltration processes occur mostly through preferential infiltration zones. Stable isotope data showed a major contribution of evaporated surface water in the recharge process from many artificial or natural ponds. Groundwater residence time determination highlighted the spatio-temporal heterogeneity of flow path organisation within aquifers, with variable contributions between fast vertical flow (present-day end-member; 15-85 %) and a slower horizontal flow (old end-member <1960), underlining the vulnerability of aquifers to present-day environmental stress or pollution.
Marjorie Kreis, Jean-Denis Taupin, Nicolas Patris, Eduardo S P R Martins

2781 related Products with: Isotopic characterisation and dating of groundwater recharge mechanisms in crystalline fractured aquifers: example of the semi-arid Banabuiú watershed (Brazil).

25 mg5mg10mg10mg20mg10mg10mg100ug5mg10mg1 mg10mg

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#32744774   2020/08/03 To Up

Aromatic Linkers Unleash the Antiproliferative Potential of 3-Chloropiperidines Against Pancreatic Cancer Cells.

In the present study we describe the synthesis and biological evaluation of a set of bis -3-chloropiperidines (B-CePs) containing rigid aromatic linker structures. A modification of the synthetic strategy also enabled the synthesis of a pilot tris -3-chloropiperidine (Tri-CeP) bearing three reactive chloropiperidine moieties in meta on the aromatic scaffold. The structure-reactivity relationship analysis of B-CePs suggests that the arrangement of the reactive units affects the DNA alkylating activity, while also revealing correlations between the electron density of the aromatic system and the reactivity with biologically relevant nucleophiles, both on isolated DNA and in cancer cells. Interestingly, all aromatic 3-chloropiperidines exhibited a marked cytotoxicity and tropism for 2D and 3D cultures of pancreatic cancer cells. Therefore, the new aromatic 3-chloropiperidines appear to be promising contenders for further development of mustard based anticancer agents aimed at pancreatic cancers.
Barbara Gatto, Tim Helbing, Caterina Carraro, Alexander Francke, Alice Sosic, Michele De Franco, Valentina Gandin, Richard Göttlich

1378 related Products with: Aromatic Linkers Unleash the Antiproliferative Potential of 3-Chloropiperidines Against Pancreatic Cancer Cells.

1.00 flask96T96 tests

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#32744773   2020/08/03 To Up

Development and validation of a colour spot test method for the presumptive detection of 25-NBOMe compounds.

The great increase of new psychoactive substances over the last decade has substantially transformed the illicit drug industry to an ever-changing dynamic market. 25-NBOMe compounds are just one of these new substance groups that pose a public health risk in many countries around the world. These highly potent, hallucinogenic phenethylamines have previously been sold as 'legal highs' or 'synthetic LSD' and the necessity to rapidly identify their presence is crucial. While there are many laboratory-based analytical methods capable of identifying these compounds, the lack of presumptive test methods indicates the need for a specific and timely test that could be used in the field. Herein we outline the developed chemical spot test that can selectively identify the presence of 25-NBOMe compounds and related analogues through the reaction with a substituted benzoquinone reagent under basic conditions. This test method has been comprehensively validated showing a high level of selectivity, specificity and precision with only two other illicit substances producing similar positive results as 25-NBOMe and few false-negative results seen. The working limit of detection was determined to be 225 μg and there was no cross-reactivity from potential adulterants of significance. This test has also been shown to work directly with blotter papers containing 25-NBOMe compounds, indicating no interference from this common matrix and the ability to differentiate these compounds from LSD. This method shows a high potential to be translated to a field compatible test that is simple, rapid, and selective for 25-NBOMe compounds.
Laura Clancy, Morgan Philp, Ronald Shimmon, Shanlin Fu

1794 related Products with: Development and validation of a colour spot test method for the presumptive detection of 25-NBOMe compounds.

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#32744765   2020/08/03 To Up

Synthesis and Reactivity of Bis(silylene)-Coordinated Calcium and Divalent Lanthanide Complexes.

Divalent lanthanide complexes of Eu ( 1 ) and Yb ( 2 ) coordinated by a chelating pyridine-based bis(silylene) ligand were isolated and fully characterized. Compared to the Eu(II) complex 1 , the Yb(II) complex 2 presents a lower thermal stability, resulting in the activation of one Si(II)-N bond and formation of an Yb(III) complex ( 3 ), which features a unique silylene-pyridyl-amido ligand. The different thermal stability of 1 and 2 points towards reduction-induced cleavage of one Si(II)-N bond of the bis(silylene) ligand. Successful isolation of the corresponding redox-inert bis(silylene) Ca(II) complex ( 5 ) was achieved at low temperature and thermal decomposition into a Ca(II) complex ( 4 ) bearing the same silylene-pyridyl-amido ligand was identified. In this case, the thermolysis reaction proceeds through another, non-redox induced, mechanism. An alternative higher yielding route to 4 was developed through an in situ generated silylene-pyridyl-amine proligand.
Peter Werner Roesky, Xiaofei Sun, Thomas Simler, Kevin Reiter, Florian Weigend

2629 related Products with: Synthesis and Reactivity of Bis(silylene)-Coordinated Calcium and Divalent Lanthanide Complexes.

50 ug 200ul10 mg1 ml100 mg100ug5mg25 mg100 mg 25 MG100ul200ug

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#32744750   2020/08/03 To Up

Experimental and Computational Studies on a Base-Free Terminal Uranium Phosphinidene Metallocene.

The first stable base-free terminal uranium phosphinidene metallocene is presented. Its structure and reactivity have been studied in detail and compared to that of the corresponding thorium derivative. Salt metathesis reaction of the methyl iodide uranium metallocene Cp''' 2 U(I)Me ( 2 , Cp''' = η 5 -1,2,4-(Me 3 C) 3 C 5 H 2 ) with Mes*PHK (Mes* = 2,4,6-(Me 3 C) 3 C 6 H 2 ) in THF yields the base-free terminal uranium phosphinidene metallocene, Cp''' 2 U=PMes* ( 3 ). In addition, density functional theory (DFT) studies suggest substantial 5f orbital contributions to the bonding within the uranium phosphinidene [U]=PAr moiety, which result in a more covalent bonding between the [Cp''' 2 U] 2+ and [Mes*P] 2- fragments than that for the related thorium derivative. This difference in bonding causes different reactivity patterns. Therefore, the uranium derivative 3 may act as a Cp''' 2 U(II) synthon releasing the phosphinidene moiety (Mes*P:) when treated with alkynes or a variety of hetero-unsaturated molecules such as imines, thiazoles, ketazines, bipy, organic azides, diazene derivatives, ketones, and carbodiimides.
Marc D Walter, Deqiang Wang, Guohua Hou, Guofu Zi, Wanjian Ding

2697 related Products with: Experimental and Computational Studies on a Base-Free Terminal Uranium Phosphinidene Metallocene.

50 mg500 100ul100ug Lyophilized100.00 ug100 ug100 assays100ul1 mg100ug25 mg100.00 ug

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#32743600   2020/07/20 To Up

Dynamics and significance of the antibody response to SARS-CoV-2 infection.

Characterizing the humoral immune response to SARS-CoV-2 and developing accurate serologic assays are needed for diagnostic purposes and estimating population-level seroprevalence.
Anita S Iyer, Forrest K Jones, Ariana Nodoushani, Meagan Kelly, Margaret Becker, Damien Slater, Rachel Mills, Erica Teng, Mohammad Kamruzzaman, Wilfredo F Garcia-Beltran, Michael Astudillo, Diane Yang, Tyler E Miller, Elizabeth Oliver, Stephanie Fischinger, Caroline Atyeo, A John Iafrate, Stephen B Calderwood, Stephen A Lauer, Jingyou Yu, Zhenfeng Li, Jared Feldman, Blake M Hauser, Timothy M Caradonna, John A Branda, Sarah E Turbett, Regina C LaRocque, Guillaume Mellon, Dan H Barouch, Aaron G Schmidt, Andrew S Azman, Galit Alter, Edward T Ryan, Jason B Harris, Richelle C Charles

1610 related Products with: Dynamics and significance of the antibody response to SARS-CoV-2 infection.

200ug200ul1 module200ul20mg200ul100 g

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