The synthesis and first full structural elucidation of a benzotriazole azo dye

Although azo dyes containing benzotriazole are of interest as substrates for surface enhanced resonance Raman scattering, SERRS, little is known of their molecular structure due to their poor crystal growth properties. We recently synthesised a highly crystalline dihydroquinoline via an unusual condensation reaction and we report herein that the azo‐benzotriazole dye subsequently formed was sufficiently crystalline to allow structural elucidation using synchroton radiation. It was found that this benzotriazole dye exists as the unexpected 6‐isomer and the structure of the dihydroquinoline moiety changes markedly on coupling due to increased delocalisation.     

Collaborative Workshops and Student Academic Performance in Introductory College Mathematics Courses: A Study of a Treisman Model Math Excel Program

High failure rates in introductory college mathematics courses, particularly among underrepresented groups of students, have been of concern for many years. One approach to the problem experiencing some success has been Treisman's Emerging Scholars workshop model. The model involves supplemental workshops in which students solve problems in collaborative learning groups. This study reports on the effectiveness of Math Excel, an implementation of the Treisman model for introductory mathematics courses (college algebra, precalculus, differential calculus, and integral calculus) at Oregon State University over five academic terms. Regression analyses revealed a significant effect on achievement (.671 grade points on a 4‐point scale) favoring Math Excel students. Even after adjusting for prior mathematics achievement using linear regression with SAT‐M as predictor, Math Excel groups' grade averages were over half a grade point better than predicted (significant at the .001 level). This study provides supporting evidence that programs like Math Excel can help students in making a successful transition to college mathematics study.     

A Mechanistic Model of Gas-Condensate Flow in Pores

Recent experimental results reported in the literature indicate that the relative permeability of gas-condensate systems increases with rate (velocity) at some conditions. To gain a better understanding of the nature of the flow and the prevailing mechanisms resulting in such behaviour flow visualisation experiments have been performed, using high pressure micromodels. The observed flow behaviour at the pore level has been employed to develop a mechanistic model describing the coupled flow of gas and condensate phases. The results of the model simulating the observed simultaneous flow of gas and condensate phases have been compared with reported core experimental results. Most features of the reported rate effect are predictable by the developed single pore model, nevertheless, its extension to include multiple pore interaction is recommended.     

Gallium Zigzag Chains as an Ordering Principle in η5‐2,5‐di‐(t‐butyl) phospholylgallium(I)

The solid state structure of η⁵‐2,5‐di‐(t‐butyl)phospholylgallium(I) 1 was determined by X‐ray diffraction at 190 K. The molecules of 1 are partly organized in a for sandwich complexes new type of structure: a Ga zigzag chain in which the aromatic phospholyl rings alternate on both sides of the chain.     

Influence of Nanoscale Surface Topography and Chemistry on the Functional Behaviour of an Adsorbed Model Macromolecule

The functional behaviour of a model macromolecule (fibrinogen) adsorbed at the nanofabricated solid‐liquid interface was found to be strongly influenced by the local topographic structure of the interface. Protein molecules bound at topographically structured surfaces (either chemically homogeneous or heterogeneous 40‐nm diameter and 10‐nm deep pits) were found to bind platelets significantly faster than uncoated substrates whereas proteins bound to flat (R_a 1 nm) substrates were not. During the initial interaction, the chemistry of the underlying substrate apparently does not affect the macromolecules' functional behaviour.     

The Search for New‐Generation Olefin Polymerization Catalysts: Life beyond Metallocenes

Even late transition metal complexes function as active and selective catalysts for α‐olefin polymerization. The discovery of a highly active family of catalysts 1 based on iron, a metal that had no previous track record in this field, has highlighted the possibilities for further new catalyst discoveries. As a result, an intense search has developed for new‐generation catalysts, in both academic and industrial research laboratories. R¹=H, Me; R²=Me, iPr; R³=H, Me, iPr; R⁴=H, Me; X=halide.     

An In Vitro Assessment of Immunostimulatory Responses to Ten Model Innate Immune Response Modulating Impurities (IIRMIs) and Peptide Drug Product,Teriparatide

Understanding, predicting, and minimizing the immunogenicity of peptide-based therapeutics are of paramount importance for ensuring the safety and efficacy of these products. The so-called anti-drug antibodies (ADA) may have various clinical consequences, including but not limited to the alteration in the product’s distribution, biological activity, and clearance profiles. The immunogenicity of biotherapeutics can be influenced by immunostimulation triggered by the presence of innate immune response modulating impurities (IIRMIs) inadvertently introduced during the manufacturing process. Herein, we evaluate the applicability of several in vitro assays (i.e., complement activation, leukocyte proliferation, and cytokine secretion) for the screening of innate immune responses induced by ten common IIRMIs (Bacillus subtilis flagellin, FSL-1, zymosan, ODN2006, poly(I:C) HMW, poly(I:C) LMW, CLO75, MDP, ODN2216, and Escherichia coli O111:B4 LPS), and a model biotherapeutic Forteo™ (teriparatide). Our study identifies cytokine secretion from healthy human donor peripheral blood mononuclear cells (PBMC) as a sensitive method for the in vitro monitoring of innate immune responses to individual IIRMIs and teriparatide (TP). We identify signature cytokines, evaluate both broad and narrow multiplex cytokine panels, and discuss how the assay logistics influence the performance of this in vitro assay.     

What's in an Atom? A Comparison of Carbon and Silicon-Centred Amidinium⋅⋅⋅Carboxylate Frameworks**

Despite their apparent similarity, framework materials based on tetraphenylmethane and tetraphenylsilane building blocks often have quite different structures and topologies. Herein, we describe a new silicon tetraamidinium compound and use it to prepare crystalline hydrogen bonded frameworks with carboxylate anions in water. The silicon-containing frameworks are compared with those prepared from the analogous carbon tetraamidinium: when biphenyldicarboxylate or tetrakis(4-carboxyphenyl)methane anions were used similar channel-containing networks are observed for both the silicon and carbon tetraamidinium. When terephthalate or bicarbonate anions were used, different products form. Insights into possible reasons for the different products are provided by a survey of the Cambridge Structural Database and quantum chemical calculations, both of which indicate that, contrary to expectations, tetraphenylsilane derivatives have less geometrical flexibility than tetraphenylmethane derivatives, that is, they are less able to distort away from ideal tetrahedral bond angles.