Single-molecule magnets (SMMs) and single-chain magnets (SCMs), also known as molecular nanomagnets, are molecular species of nanoscale proportions with the potential for high information storage ...density and spintronics applications. Metal-organic frameworks (MOFs) are three-dimensional ordered assemblies of inorganic nodes and organic linkers, featuring structural diversity and multiple chemical and physical properties. The concept of using these frameworks as scaffolds in the study of molecular nanomagnets provides an opportunity to constrain the local coordination geometries of lanthanide centers and organize the individual magnetic building blocks (MBBs, including both transition-metal and lanthanide MBBs) into topologically well-defined arrays that represent two key factors governing the magnetic properties of molecular nanomagnets. In this tutorial review, we summarize recent progress in this newly emerging field.
Rather than searching for a universal optimal level of multinationality for all firms, we argue that firm-specific attributes should result in firm-specific optimal levels of multinationality. ...Specifically, we draw upon transaction cost and internalization theory to argue that there will be different optimal levels of multinationality for individual firms, and if firms internalize foreign operations to an extent less than or greater than their individual optimal levels, transaction costs will increase and performance will decrease. To test this idea, we use transaction cost models in the context of large US law firms during the time period from 1986 through 2008 to estimate firm-specific optimal multinationality. Next, we test relationships between alignment with, or deviations from, firm-specific optimal levels of multinationality and performance (MA-P). Consistent with the MA-P hypothesis, insufficient and excessive levels of multinationality are both negatively related to financial performance. In addition, excessive multinationality is positively associated with downside performance risk. One key implication is that an MA-P approach may offer greater theoretical validity and clarity than traditional multinationality and performance (M-P) approaches.
Transaction cost and internalization theory offers that firm-specific transaction-cost factors determine firm-specific optimal levels of multinationality. Decision makers should prefer alignment with ...optimal levels of multinationality. Yet, some firms continuously misalign with their optimal levels of multinationality. We argue that having multiple preferences may explain these ‘misfit’ firms. Specifically, firms with international experience may develop an inertial preference for further international growth, along with their preference for efficiency/optimization. Hence, more internationally experienced firms with insufficient multinationality will increase their levels of multinationality in subsequent time periods to satisfy both preferences. However, growth preferences in more internationally experienced firms with excess multinationality will counter optimization preferences, reducing the likelihood of decreases to levels of multinationality in subsequent periods. We find support for these ideas in the context of 242 Japanese electrical appliance firms between 2011 and 2019 (1401 firm-year observations).
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
A giant tetrahedral heterometallic polyoxometalate (POM) Dy30Co8Ge12W108O408(OH)42(OH2)3056−, which shows single‐molecule magnet (SMM) behavior, is described. This hybrid contains the largest number ...of 4f ions of any polyoxometalate (POM) reported to date and is the first to incorporate two different 3d–4f and 4f coordination cluster assemblies within same POM framework.
Record SMM POM: A new class of polyoxometalate (POM) containing 3d–4f and 4f aggregates encapsulated by A‐α‐GeW9O3410− ligands to give Dy30Co8Ge12W108O408(OH)42(OH2)3056− is described. This hybrid with single‐molecule magnet (SMM) behavior contains the largest number of 4f ions of any POM reported to date and is the first to incorporate two different 3d–4f and 4f coordination cluster assemblies within same POM framework.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Multitopic organic linkers can provide a means to organize metal cluster nodes in a regular three‐dimensional array. Herein, we show that isonicotinic acid N‐oxide (HINO) serves as the linker in the ...formation of a metal–organic framework featuring Dy2 single‐molecule magnets as nodes. Importantly, guest solvent exchange induces a reversible single‐crystal to single‐crystal transformation between the phases Dy2(INO)4(NO3)2⋅2 solvent (solvent=DMF (Dy2‐DMF), CH3CN (Dy2‐CH3CN)), thereby switching the effective magnetic relaxation barrier (determined by ac magnetic susceptibility measurements) between a negligible value for Dy2‐DMF and 76 cm−1 for Dy2‐CH3CN. Ab initio calculations indicate that this difference arises not from a significant change in the intrinsic relaxation barrier of the Dy2 nodes, but rather from a slowing of the relaxation rate of incoherent quantum tunneling of the magnetization by two orders of magnitude.
Guest swap: Exchange of the guest molecules within the pores of a metal–organic framework (MOF) featuring Dy2 single‐molecule magnets as nodes imparts major changes in the magnetization relaxation dynamics (see picture; spectra recorded from 2 K (blue plots) to 9 K (red)). As a result of guest exchange, significantly different effective relaxation barriers (Ueff) for the compound are measured. Atom colors: Dy=green, O=red, N=blue, C=gray.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
The high axiality and Ising exchange interaction efficiently suppress quantum tunneling of magnetization of an asymmetric dinuclear DyIII complex, as revealed by combined experimental and theoretical ...investigations. Two distinct regimes of blockage of magnetization, one originating from the blockage at individual Dy sites and the other due to the exchange interaction between the sites, are separated for the first time. The latter contribution is found to be crucial, allowing an increase of the relaxation time by 3 orders of magnitude.
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IJS, KILJ, NUK, PNG, UL, UM
Although motor deficits are common in autism, the neural correlates underlying the disruption of even basic motor execution are unknown. Motor deficits may be some of the earliest identifiable signs ...of abnormal development and increased understanding of their neural underpinnings may provide insight into autism-associated differences in parallel systems critical for control of more complex behaviour necessary for social and communicative development. Functional magnetic resonance imaging was used to examine neural activation and connectivity during sequential, appositional finger tapping in 13 children, ages 8–12 years, with high-functioning autism (HFA) and 13 typically developing (TD), age- and sex-matched peers. Both groups showed expected primary activations in cortical and subcortical regions associated with motor execution contralateral primary sensorimotor cortex, contralateral thalamus, ipsilateral cerebellum, supplementary motor area (SMA); however, the TD group showed greater activation in the ipsilateral anterior cerebellum, while the HFA group showed greater activation in the SMA. Although activation differences were limited to a subset of regions, children with HFA demonstrated diffusely decreased connectivity across the motor execution network relative to control children. The between-group dissociation of cerebral and cerebellar motor activation represents the first neuroimaging data of motor dysfunction in children with autism, providing insight into potentially abnormal circuits impacting development. Decreased cerebellar activation in the HFA group may reflect difficulty shifting motor execution from cortical regions associated with effortful control to regions associated with habitual execution. Additionally, diffusely decreased connectivity may reflect poor coordination within the circuit necessary for automating patterned motor behaviour. The findings might explain impairments in motor development in autism, as well as abnormal and delayed acquisition of gestures important for socialization and communication.
Recent evidence suggests that lifelong bilingualism may contribute to cognitive reserve (CR) in normal aging. However, there is currently no neuroimaging evidence to suggest that lifelong bilinguals ...can retain normal cognitive functioning in the face of age-related neurodegeneration. Here we explored this issue by comparing white matter (WM) integrity and gray matter (GM) volumetric patterns of older adult lifelong bilinguals (N=20) and monolinguals (N=20). The groups were matched on a range of relevant cognitive test scores and on the established CR variables of education, socioeconomic status and intelligence. Participants underwent high-resolution structural imaging for assessment of GM volume and diffusion tensor imaging (DTI) for assessment of WM integrity. Results indicated significantly lower microstructural integrity in the bilingual group in several WM tracts. In particular, compared to their monolingual peers, the bilingual group showed lower fractional anisotropy and/or higher radial diffusivity in the inferior longitudinal fasciculus/inferior fronto-occipital fasciculus bilaterally, the fornix, and multiple portions of the corpus callosum. There were no group differences in GM volume. Our results suggest that lifelong bilingualism contributes to CR against WM integrity declines in aging.
•We explored whether lifelong bilingualism contributes to cognitive reserve.•Bilingual and monolingual older adults participated.•Groups were matched on demographic variables and cognitive test scores.•Bilinguals had lower white matter integrity than monolinguals.•Lifelong bilingualism appears to contribute to cognitive reserve.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
3D printing of foods is an emerging technology that makes it possible to produce unique and complex food items. A number of different foods have already been 3D printed, however, better ...characterisation of fabrication parameters is still necessary to improve quality and efficiency. In this paper, we present details of the construction of a melt extrusion 3D printer based on readily available open source components. Several key fabrication parameters were investigated and optimised to enable printing complex 3D objects made from chocolate. The ability of an extruded chocolate fibre to span large distances without collapsing was investigated by adjusting variables such as movement speeds, extrusion rates and cooling rates. We found that the chocolate spanning distance was unaffected by movement speeds ranging from 300 to 700 mm/min, and that the optimal extrusion rate was 10–20% leaner. Furthermore, the spanning distance improved by directing air across the printing part, lowering the air temperature by approximately 3.5 °C. The results from this research can be applied to 3D printing of complex objects using chocolate and other similar foods.
•Design of a melt extrusion chocolate printer with readily available components.•Movement Speed has no effect on bridging distance.•Extrusion multiplier may be optimized at 0.8–0.9.•Air quenching flow rate was no effect on bridging distance.•Air quenching temperature has substantial effect on bridging distance.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
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