Research Summary
Literature suggests that firms may approximate ambidexterity over time by alternating between periods of exploration and exploitation. We theorize and empirically test performance ...implications of two types of temporal transition between exploration and exploitation and their boundary conditions. We find that a discontinuous jump has a negative effect on firm performance while an incremental transition has a positive effect. We also find that the role of firm resources and particularly that of non‐scale‐free resources is critical in shaping the performance effects of the two types of temporal transition. Our findings indicate that the two types of temporal transition have distinct advantages and disadvantages.
Managerial Summary
Firms need to make use of old ideas and search for new ideas to remain competitive. We argue that firms take different approaches to achieve this goal. We find that firms that alternate between old and new ideas in an incremental and continuous manner perform better than firms that switch abruptly between old and new ideas. We also find that the performance effects of the two approaches are more pronounced for firms with limited resources. This finding warns managers of the danger of an abrupt and discontinuous jump between old and new ideas, especially for firms with limited resources.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Humidity sensors are essential components in wearable electronics for monitoring of environmental condition and physical state. In this work, a unique humidity sensing layer composed of ...nitrogen‐doped reduced graphene oxide (nRGO) fiber on colorless polyimide film is proposed. Ultralong graphene oxide (GO) fibers are synthesized by solution assembly of large GO sheets assisted by lyotropic liquid crystal behavior. Chemical modification by nitrogen‐doping is carried out under thermal annealing in H2(4%)/N2(96%) ambient to obtain highly conductive nRGO fiber. Very small (≈2 nm) Pt nanoparticles are tightly anchored on the surface of the nRGO fiber as water dissociation catalysts by an optical sintering process. As a result, nRGO fiber can effectively detect wide humidity levels in the range of 6.1–66.4% relative humidity (RH). Furthermore, a 1.36‐fold higher sensitivity (4.51%) at 66.4% RH is achieved using a Pt functionalized nRGO fiber (i.e., Pt‐nRGO fiber) compared with the sensitivity (3.53% at 66.4% RH) of pure nRGO fiber. Real‐time and portable humidity sensing characteristics are successfully demonstrated toward exhaled breath using Pt‐nRGO fiber integrated on a portable sensing module. The Pt‐nRGO fiber with high sensitivity and wide range of humidity detection levels offers a new sensing platform for wearable humidity sensors.
Nitrogen‐doped graphene fiber functionalized by Pt nanoparticles (Pt‐nRGO fiber) is integrated on a flexible and transparent polyimide substrate for application in real‐time and on‐site monitoring of humidity. This work demonstrates the humidity sensing characteristic of Pt‐nRGO fiber, which further expands versatility of graphene‐based fiber in wearable sensing electronics.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Achieving an improved understanding of catalyst properties, with ability to predict new catalytic materials, is key to overcoming the inherent limitations of metal oxide based gas sensors associated ...with rather low sensitivity and selectivity, particularly under highly humid conditions. This study introduces newly designed bimetallic nanoparticles (NPs) employing bimetallic Pt‐based NPs (PtM, where M = Pd, Rh, and Ni) via a protein encapsulating route supported on mesoporous WO3 nanofibers. These structures demonstrate unprecedented sensing performance for detecting target biomarkers (even at p.p.b. levels) in highly humid exhaled breath. Sensor arrays are further employed to enable pattern recognition capable of discriminating between simulated biomarkers and controlled breath. The results provide a new class of multicomponent catalytic materials, demonstrating potential for achieving reliable breath analysis sensing.
Effective strategy to readily synthesize highly dispersed Pt‐based bimetallic (PtM, where M = Pd, Rh, and Ni) NPs as a new class of active catalysts is successfully developed on the highly porous architecture of 1D WO3 nanofibers via a protein template, i.e., apoferritin, in combination with the electrospinning method for superior exhaled‐breath sensors.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
This study investigates corporate social responsibility (CSR) of sinful firms, which refer to ones that are operating in controversial industries, including the production and distribution of ...alcohol, tobacco, gambling, adult entertainment, firearm, military, and nuclear power. We attempt to answer two questions in this study: (1) Do these sinful firms actively advertise their CSR engagements compared to non-sinful firms? And (2) do their advertising efforts really yield increased financial performance? Positing that advertising not only can make sinful firms' good deeds visible, but also can highlight the contradiction between these firms' stigma and their prosocial activities, we claim that sinful firms are likely to advertise their CSR engagement to overcome their stigmatized firm image, but these advertising activities will make the firms' performance vulnerable by inducing skepticism from stakeholders. Using KLD database in conjunction with COMPUSTAT and Center for Research in Security Prices from 1991 to 2010, where 337 firms are involved in the controversial sinful industries, namely tobacco, alcohol, gaming, firearms, military, and nuclear power, we examine the effect of advertising spending of sinful firms' CSR engagement on performance vulnerability, which is instantiated with idiosyncratic risk. The empirical results indicate that sinful firms increase their advertising expenditure when they engage in CSR programs, but these efforts for advertising CSR tend to increase idiosyncratic risk. This finding indicates that even though sinful firms can benefit from engaging in socially responsible initiatives, advertising their CSR efforts may backfire.
Research summary: Since Nickerson and Zenger (2002) proposed how vacillation may lead to organizational ambidexterity, large-sample empirical tests of their theory have been missing. In this paper, ...we empirically examine the performance implications of vacillation. Building upon vacillation theory, we predict that the frequency and scale of vacillation will have inverted U-shaped relationships with firm performance. We test our hypotheses using patent-based measures of exploration and exploitation in the context of technological innovation and knowledge search. Managerial summary: Firms often shift their focus on technological innovation and knowledge search from seeking new and novel knowledge (i.e., exploration) to extending and refining existing knowledge (i.e., exploitation) or vice versa. We examine how the frequency and scale of firms vacillating between exploration and exploitation may affect their performance. We find that both too infrequent or too frequent changes and a too small or too large scale of changes are not desirable.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
We report on the heterogeneous sensitization of metal–organic framework (MOF)-driven metal-embedded metal oxide (M@MO) complex catalysts onto semiconductor metal oxide (SMO) nanofibers (NFs) via ...electrospinning for markedly enhanced chemical gas sensing. ZIF-8-derived Pd-loaded ZnO nanocubes (Pd@ZnO) were sensitized on both the interior and the exterior of WO3 NFs, resulting in the formation of multiheterojunction Pd–ZnO and ZnO–WO3 interfaces. The Pd@ZnO loaded WO3 NFs were found to exhibit unparalleled toluene sensitivity (R air /R gas = 4.37 to 100 ppb), fast gas response speed (∼20 s) and superior cross-selectivity against other interfering gases. These results demonstrate that MOF-derived M@MO complex catalysts can be functionalized within an electrospun nanofiber scaffold, thereby creating multiheterojunctions, essential for improving catalytic sensor sensitization.
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IJS, KILJ, NUK, PNG, UL, UM
Practical sensing applications such as real‐time safety alerts and clinical diagnoses require sensor devices to differentiate between various target molecules with high sensitivity and selectivity, ...yet conventional devices such as oxide‐based chemo‐resistive sensors and metal‐based surface‐enhanced Raman spectroscopy (SERS) sensors usually do not satisfy such requirements. Here, a label‐free, chemo‐resistive/SERS multimodal sensor based on a systematically assembled 3D cross‐point multifunctional nanoarchitecture (3D‐CMA), which has unusually strong enhancements in both “chemo‐resistive” and “SERS” sensing characteristics is introduced. 3D‐CMA combines several sensing mechanisms and sensing elements via 3D integration of semiconducting SnO2 nanowire frameworks and dual‐functioning Au metallic nanoparticles. It is shown that the multimodal sensor can successfully estimate mixed‐gas compositions selectively and quantitatively at the sub‐100 ppm level, even for mixtures of gaseous aromatic compounds (nitrobenzene and toluene) with very similar molecular structures. This is enabled by combined chemo‐resistive and SERS multimodal sensing providing complementary information.
Synergistic electrical and optical multimodal sensing by 3D nanoarchitectures for label‐free gas detection is reported.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Since mid-December of 2019, coronavirus disease 2019 (COVID-19) has been spreading from Wuhan, China. The confirmed COVID-19 patients in South Korea are those who came from or visited China. As ...secondary transmissions have occurred and the speed of transmission is accelerating, there are rising concerns about community infections. The 54-year old male is the third patient diagnosed with COVID-19 in Korea. He is a worker for a clothing business and had mild respiratory symptoms and intermittent fever in the beginning of hospitalization, and pneumonia symptoms on chest computerized tomography scan on day 6 of admission. This patient caused one case of secondary transmission and three cases of tertiary transmission. Hereby, we report the clinical findings of the index patient who was the first to cause tertiary transmission outside China. Interestingly, after lopinavir/ritonavir (Kaletra, AbbVie) was administered, β-coronavirus viral loads significantly decreased and no or little coronavirus titers were observed.
1D metal‐oxide nanotube (NT) structures have attracted considerable attention for applications in chemical sensors due to their high surface area and unique chemical and physical properties. ...Moreover, bimodal pores, i.e., meso‐ and macro‐sized pores, which are formed on the shell of NTs, can further facilitate gas penetration into the sensing layers, leading to much improved sensing properties. However, thin‐walled NTs with bimodal pore distribution have been rarely fabricated due to the limitations of synthetic methods. Here, Ostwald ripening‐driven electrospinning combined with sacrificial templating route using polystyrene (PS) colloid and bioinspired protein is firstly proposed for producing both bi‐modal pores and catalyst‐loaded thin‐walled SnO2 NTs. Homogeneous catalyst loading on porous SnO2 NTs is achieved by the protein cage that contains catalysts and PS colloids and protein shells are thermally decomposed during calcination of electrospun fibers, resulting in the creation of dual‐sized pores on NTs. Pt catalyst decorated porous SnO2 NTs (Pt‐PS_SnO2 NTs) show exceptionally high acetone gas response, superior selectivity against other interfering gases, and very low limit of detection (10 ppb) to simulated diabetic acetone molecules. More importantly, sensor arrays assembled with developed porous SnO2 NTs enable the direct distinction between the simulated diabetic breath and normal breath from healthy people.
Highly mesoporous SnO2 nanotubes (NTs) functionalized with large pores and bioinspired catalysts (Pt‐PS_SnO2 NTs) are simply synthesized as an ideal nanostructure of sensing layers by using biotemplating route and diffusion of SnO2 effect. Pt‐PS_SnO2 NTs exhibit dramatically enhanced acetone sensing performance; especially, they can clearly distinguish the exhaled breath of healthy people and diabetics.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Navigation of nanoparticles to target sites of blood flow disturbance markedly upgrades the diagnostic paradigm in vascular medicine. The theranostic treatment of pre‐stenotic vessels can prevent the ...irreversible occlusion process effectively. Here, these nanotheranostic functions are established by displaying CDK9(cyclin‐dependent kinase 9)‐targeting peptide (P.) onto nanovesicles (NV) and liposomes using the navigation function and subsequent binding‐on signaling of P. as a game‐changer. When rabbit vessels are allografted with injecting contrast‐loaded P. liposomes, the case‐dependent stenotic degree after 2–6 weeks can be diagnosed accurately within 2–4 days via computed tomography imaging with cross‐validation in a mouse model of partial carotid ligation. Furthermore, the anti‐CDK9 signaling of P. NV is activated post‐targeting and effectively prevents vascular stenosis by suppressing inflammation and lipotoxicity in the vessels, serum, and/or liver. CDK9 targeting is confirmed using computer, in vitro, and in vivo models. This study demonstrates an unprecedented nanotheranostic function for future clinical applications.
The disturbed flow‐sensing peptide plays a game‐changer role in guiding diagnosis and treatment of pre‐stenotic vessels as a theranostic navigator. Displaying the peptide on nanoparticles enables accurate prediction of vascular stenosis with subsequent prevention of vascular remodeling through multi‐organ targeting. The results from rabbit, mouse, and in vitro models validates an unprecedented nanotheranostic function for the future medicine.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
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