Osmium(II) polypyridines are a well-known class of complexes with luminescent metal-to-ligand charge-transfer (MLCT) excited states that are currently experiencing a revival due to their application ...potential in organic photoredox catalysis, triplet–triplet annihilation upconversion, and phototherapy. At the same time, there is increased interest in the development of photoactive complexes made from Earth-abundant rather than precious metals. Against this background, we present a homoleptic Mo(0) complex with a new diisocyanide ligand exhibiting different bite angles and a greater extent of π-conjugation than previously reported related chelates. This new design leads to deep red emission, which is unprecedented for homoleptic arylisocyanide complexes of group 6 metals. With a 3MLCT lifetime of 56 ns, an emission band maximum at 720 nm, and a photoluminescence quantum yield of 1.5% in deaerated toluene at room temperature, the photophysical properties are reminiscent of the prototypical Os(2,2′-bipyridine)32+ complex. Under 635 nm irradiation with a cw-laser, the new Mo(0) complex sensitizes triplet–triplet annihilation upconversion of 9,10-diphenylanthracene (DPA), resulting in delayed blue fluorescence with an anti-Stokes shift of 0.93 eV. The photorobustness of the Mo(0) complex and the upconversion quantum yield are high enough to generate a flux of upconverted light that can serve as a sufficiently potent irradiation source for a blue-light-driven photoisomerization reaction. These findings are relevant in the greater contexts of designing new luminophores and photosensitizers for use in red-light-driven photocatalysis, photochemical upconversion, light-harvesting, and phototherapy.
Inequality's effect on growth remains elusive, largely due to endogeneity, complex interactions, and lead–lag relationships. We revisit this issue by examining the four main channels through which ...inequality transmits to growth: savings, investment, education, and knowledge production. We construct new panel data for 21 OECD countries spanning 142 years. External communist influence is used as a new time-varying instrument for inequality and the effects of inequality on the outcome variables are made conditional on the stage of financial development. Our results show that inequality hampers growth at low to moderate levels of financial development but has little effect on growth at advanced levels of financial development.
The SNAP receptor (SNARE) complex, consisting of synaptosome-associated protein of 25 kDa (SNAP-25), synaptobrevin-2, and syntaxin-1, is involved in synaptic vesicles exocytosis. In addition, SNAP-25 ...has been implicated in constitutive exocytosis processes required for neurite outgrowth. However, at least three isoforms of SNAP-25 have been reported from neurons: SNAP-23, which is also present in non-neuronal cells, and the two alternative splice variants SNAP-25a and SNAP-25b. Here, we studied the differential ability of these isoforms to support the functions previously broadly ascribed to "SNAP-25." We studied the rescue of snap-25 null neurons in culture with different SNAP-25 homologs. We find that deletion of SNAP-25 leads to strongly reduced neuron survival, and, in the few surviving cells, impaired arborization, reduced spontaneous release, and complete arrest of evoked release. Lentiviral expression of SNAP-25a, SNAP-25b, or SNAP-23 rescued neuronal survival, arborization, amplitude, and frequency of spontaneous events. Also evoked release was rescued by all isoforms, but synchronous release required SNAP-25a/b in both glutamatergic and GABAergic neurons. SNAP-23 supported asynchronous release only, reminiscent of synaptotagmin-1 null neurons. SNAP-25b was superior to SNAP-25a in vesicle priming, resembling the shift to larger releasable vesicle pools that accompanies synaptic maturation. These data demonstrate a differential ability of SNAP-25b, SNAP-25a, and SNAP-23 to support neuronal function.
Background The use of global health items permits an efficient way of gathering general perceptions of health. These items provide useful summary information about health and are predictive of health ...care utilization and subsequent mortality. Methods Analyses of 10 self-reported global health items obtained from an internet survey as part of the Patient-Reported Outcome Measurement Information System (PROMIS) project. We derived summary scores from the global health items. We estimated the associations of the summary scores with the EQ-5D index score and the PROMIS physical function, pain, fatigue, emotional distress, and social health domain scores. Results Exploratory and confirmatory factor analyses supported a two-factor model. Global physical health (GPH; 4 items on overall physical health, physical function, pain, and fatigue) and global mental health (GMH; 4 items on quality of life, mental health, satisfaction with social activities, and emotional problems) scales were created. The scales had internal consistency reliability coefficients of 0.81 and 0.86, respectively. GPH correlated more strongly with the EQ-5D than did GMH (r = 0.76 vs. 0.S9). GPH correlated most strongly with pain impact (r = —0.75) whereas GMH correlated most strongly with depressive symptoms (r = —0.71). Conclusions Two dimensions representing physical and mental health underlie the global health items in PROMIS. These global health scales can be used to efficiently summarize physical and mental health in patient-reported outcome studies.
Aim
We aimed to improve bone health management of children with cerebral palsy (CP) by reviewing studies investigating bisphosphonate therapy in children with CP and other types of secondary ...osteoporosis.
Methods
We included trials on bisphosphonate treatment reporting any direct bone measurement or fracture outcome. All studies of patients with CP were included. We also included all controlled trials of children with secondary bone fragility as well as observational studies with ≥20 participants or at least 3 years of follow‐up. Studies were assessed according to PRISMA guidelines using the RoB2‐tool and the Newcastle‐Ottawa Scale.
Results
We reviewed 1104 studies and found 37 eligible. Some studies were sufficiently homogeneous to include in a meta‐analysis, and we found a 1‐year effect on lumbar spine bone mineral density (BMD) Z‐score of +0.65 after oral and + 1.21 after intravenous bisphosphonates in children with secondary osteoporosis. Further, data on adverse events and post‐treatment follow‐up were reviewed. Limitations were heterogeneity and small size of the included studies.
Conclusion
Meta‐analysis consistently showed significant BMD increases with bisphosphonates in children with secondary osteoporosis. Direct evidence of the effect of bisphosphonates on reducing fractures is lacking. We found no reports of long‐term adverse events yet longer studies are needed.
Hydrogen-air mixtures are highly flammable. Hydrogen sensors are therefore of paramount importance for timely leak detection during handling. However, existing solutions do not meet the stringent ...performance targets set by stakeholders, while deactivation due to poisoning, for example by carbon monoxide, is a widely unsolved problem. Here we present a plasmonic metal-polymer hybrid nanomaterial concept, where the polymer coating reduces the apparent activation energy for hydrogen transport into and out of the plasmonic nanoparticles, while deactivation resistance is provided via a tailored tandem polymer membrane. In concert with an optimized volume-to-surface ratio of the signal transducer uniquely offered by nanoparticles, this enables subsecond sensor response times. Simultaneously, hydrogen sorption hysteresis is suppressed, sensor limit of detection is enhanced, and sensor operation in demanding chemical environments is enabled, without signs of long-term deactivation. In a wider perspective, our work suggests strategies for next-generation optical gas sensors with functionalities optimized by hybrid material engineering.
It is well established in the literature that financial development (ED) is conducive to growth, and yet the channels through which FD affects growth are not well understood. Using a unique new panel ...data set for 21 OECD countries over the past 140 years, this paper examines the extent to which FD transmits to growth through ideas production, savings, fixed investment, and schooling. Unionization and agricultural share are used as instruments for FD. The empirical results show that FD influences growth through all four channels. In particular, ideas production is found to be the most important channel through which FD affects growth.
Fast exocytosis of synaptic vesicles differs from other membrane fusion reactions by being under tight temporal control by the intracellular calcium concentration. This is achieved by subjecting the ...SNARE-dependent fusion pathway to additional layers of control, both upstream and downstream of the assembly of the fusogenic SNARE-complex. Here, I review conflicting views on the function of the core fusion machinery consisting of the SNAREs, Munc18, complexin, and synaptotagmin. Munc18 controls docking of vesicles to the plasma membrane and initial SNARE-complex assembly, whereas complexin and synaptotagmin cooperate in holding the SNARE complex in an intermediate release-ready or cocked state. Different effects of complexin and synaptotagmin shape the energy landscape for fusion and make final fusion calcium triggered. The final steps are fusion pore formation and expansion, which allow release of the water-soluble vesicle content. The fusion pore remains the most elusive part of the exocytosis pathway, owing to its short lifetime.
Rotation during reactionDetermining changes in heterogeneous catalysts under reaction conditions can provide insight into mechanisms. Under reaction conditions, not only can metal nanoparticles ...change shape but their interaction with the oxide support could also be affected. Yuan et al. used aberration-corrected environmental transmission electron microscopy to study gold nanoparticles on titanium surfaces at low electron beam doses. During carbon monoxide (CO) oxidation at total pressures of a few millibars and 500°C, they observed that gold nanoparticles rotated by about 10° but returned to their original position when CO was removed. Density function theory calculations indicated that rotation was induced by changes in the coverage of adsorbed molecular oxygen at the interface.Science, this issue p. 517The interface between metal catalyst and support plays a critical role in heterogeneous catalysis. An epitaxial interface is generally considered to be rigid, and tuning its intrinsic microstructure with atomic precision during catalytic reactions is challenging. Using aberration-corrected environmental transmission electron microscopy, we studied the interface between gold (Au) and a titanium dioxide (TiO2) support. Direct atomic-scale observations showed an unexpected dependence of the atomic structure of the Au-TiO2 interface with the epitaxial rotation of gold nanoparticles on a TiO2 surface during carbon monoxide (CO) oxidation. Taking advantage of the reversible and controllable rotation, we achieved in situ manipulation of the active Au-TiO2 interface by changing gas and temperature. This result suggests that real-time design of the catalytic interface in operating conditions may be possible.
Synchronization of neurotransmitter release with the presynaptic action potential is essential for maintaining fidelity of information transfer in the central nervous system. However, synchronous ...release is frequently accompanied by an asynchronous release component that builds up during repetitive stimulation, and can even play a dominant role in some synapses. Here, we show that substitution of SNAP-23 for SNAP-25 in mouse autaptic glutamatergic hippocampal neurons results in asynchronous release and a higher frequency of spontaneous release events (mEPSCs). Use of neurons from double-knock-out (SNAP-25, synaptotagmin-7) mice in combination with viral transduction showed that SNAP-23-driven release is triggered by endogenous synaptotagmin-7. In the absence of synaptotagmin-7 release became even more asynchronous, and the spontaneous release rate increased even more, indicating that synaptotagmin-7 acts to synchronize release and suppress spontaneous release. However, compared to synaptotagmin-1, synaptotagmin-7 is a both leaky and asynchronous calcium sensor. In the presence of SNAP-25, consequences of the elimination of synaptotagmin-7 were small or absent, indicating that the protein pairs SNAP-25/synaptotagmin-1 and SNAP-23/synaptotagmin-7 might act as mutually exclusive calcium sensors. Expression of fusion proteins between pHluorin (pH-sensitive GFP) and synaptotagmin-1 or -7 showed that vesicles that fuse using the SNAP-23/synaptotagmin-7 combination contained synaptotagmin-1, while synaptotagmin-7 barely displayed activity-dependent trafficking between vesicle and plasma membrane, implying that it acts as a plasma membrane calcium sensor. Overall, these findings support the idea of alternative syt∶SNARE combinations driving release with different kinetics and fidelity.
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