The impact of information technology culture and personal innovativeness in information technology on digital entrepreneurship success

Purpose: Very little or no study has explored the predictors of behaviour and traits that determine digital entrepreneurship (DE) success. In response, the purpose of this paper is to present a research model that takes information technology (IT) culture as a theoretical lens and personal innovativeness and experience in IT projects as theoretical constructs to predict behaviour and traits that explain DE success. Design/methodology/approach: Based on the literature review, the authors propose hypotheses and a research model. The authors tested the model using structural equation modelling (SEM), by surveying a sample of digital entrepreneurs operating in the Yabacon Valley, Lagos, Nigeria. Findings: The results indicate that IT culture is an essential predictor of achieving DE success. The results also suggest that an entrepreneur's innovativeness in IT and experience in IT projects have significant negative and positive moderating effects on the relationship between IT culture and achieving DE success. Research limitations/implications: This paper taps into a new setting – DE context – by exploring the moderation effects of an entrepreneur's innovativeness in IT and experience in IT projects on the link between their IT culture and achieving a successful DE outcome. Practical implications: This model offers managers an understanding of how IT culture and personal innovativeness and experience in IT work together to achieve DE success. Meanwhile, it sheds some light on managers to treat individuals with different levels of experience differently. Originality/value: The authors theorise IT culture, personal innovativeness and experience in IT and show their effects on DE success, thus making an essential contribution to the information systems (ISs) and entrepreneurship research and practice. Moreover, the authors provide a novel methodology to conceptualise IT culture as a second-order hierarchical reflective construct by giving evidence that partial least squares (PLS) path modelling can assess a hierarchical model with moderating effects. This study answers scholars' call to construct more accurate explanations of innovation outcomes in an increasingly digital world.</p

Human Ferrochelatase: Insights for the Mechanism of Ferrous Iron Approaching Protoporphyrin IX by QM/MM and QTCP Free Energy Studies

Ferrochelatase catalyzes the insertion of ferrous iron into protoporphyrin IX, the terminal step in heme biosynthesis. Some disputes in its mechanism remain unsolved, especially for human ferrochelatase. In this paper, high-level quantum mechanical/molecular mechanics (QM/MM) and free-energy studies were performed to address these controversial issues including the iron-binding site, the optimal reaction path, the substrate porphyrin distortion, and the presence of the sitting-atop (SAT) complex. Our results reveal that the ferrous iron is probably at the binding site coordinating with Met76, and His263 plays the role of proton acceptor. The rate-determining step is either the first proton removed by His263 or the proton transition within the porphyrin with an energy barrier of 14.99 or 14.87 kcal/mol by the quantum mechanical thermodynamic cycle perturbation (QTCP) calculations, respectively. The fast deprotonation step with the conservative residues rather than porphyrin deformation found in solution provides the driving force for biochelation. The SAT complex is not a necessity for the catalysis though it induces a modest distortion on the porphyrin ring

Facile Formation of Gold-Nanoparticle-Loaded γ‑Polyglutamic Acid Nanogels for Tumor Computed Tomography Imaging

The formation of gold nanoparticle (Au NP)-loaded γ-polyglutamic acid (γ-PGA) nanogels (NGs) for computed tomography (CT) imaging of tumors is reported. γ-PGA with carboxyl groups activated by 1-ethyl-3-[3-(dimethylamino)­propyl] carbodiimide hydrochloride is first emulsified to form NGs and then in situ chemically cross-linked with polyethylenimine (PEI)-entrapped Au NPs with partial polyethylene glycol (PEG) modification ([(Au⁰)₂₀₀–PEI·NH₂–<i>m</i>PEG]). The formed γ-PGA–[(Au⁰)₂₀₀–PEI·NH₂–<i>m</i>PEG] NGs with a size of 108.6 ± 19.1 nm display an X-ray attenuation property better than commercial iodinated small-molecular-contrast agents and can be uptaken by cancer cells more significantly than γ-PGA-stabilized single Au NPs at the same Au concentrations. These properties render the formed NGs with an ability to be used as an effective contrast agent for the CT imaging of cancer cells in vitro and a tumor model in vivo. The developed hybrid NGs may be promising for the CT imaging or theranostics of different biosystems

Radiotherapy-Sensitized Tumor Photothermal Ablation Using γ‑Polyglutamic Acid Nanogels Loaded with Polypyrrole

Development of versatile nanoscale platforms for cancer diagnosis and therapy is of great importance for applications in translational medicine. In this work, we present the use of γ-polyglutamic acid (γ-PGA) nanogels (NGs) to load polypyrrole (PPy) for thermal/photoacoustic (PA) imaging and radiotherapy (RT)-sensitized tumor photothermal therapy (PTT). First, a double emulsion approach was used to prepare the cystamine dihydrochloride (Cys)-cross-linked γ-PGA NGs. Next, the cross-linked NGs served as a reactor to be filled with pyrrole monomers that were subjected to in situ oxidation polymerization in the existence of Fe­(III) ions. The formed uniform PPy-loaded NGs having an average diameter of 38.9 ± 8.6 nm exhibited good water-dispersibility and colloid stability. The prominent near-infrared (NIR) absorbance feature due to the loaded PPy endowed the NGs with contrast enhancement in PA imaging. The hybrid NGs possessed excellent photothermal conversion efficiency (64.7%) and stability against laser irradiation, and could be adopted for PA imaging and PTT of cancerous cells and tumor xenografts. Importantly, we also explored the cooperative PTT and X-ray radiation-mediated RT for enhanced tumor therapy. We show that PTT of tumors can be more significantly sensitized by RT using the sequence of laser irradiation followed by X-ray radiation as compared to using the reverse sequence. Our study suggests a promising theranostic platform of hybrid NGs that may be potentially utilized for PA imaging and combination therapy of different types of tumors