Cardiorenal Syndrome in Right Heart Failure Due to Pulmonary Arterial Hypertension-The Right Ventricle as a Therapeutic Target to Improve Renal Function.

Cardiorenal syndrome (CRS) due to right ventricular (RV) failure is a disease entity emerging as a key indicator of morbidity and mortality. The multifactorial aspects of CRS and the left-right ventricular interdependence complicate the link between RV failure and renal function. RV failure has a direct pathophysiological link to renal dysfunction by leading to systemic venous congestion in certain circumstances and low cardiac output in other situations, both leading to impaired renal perfusion. Indeed, renal dysfunction is known to be an independent predictor of mortality in patients with pulmonary arterial hypertension (PAH) and RV failure. Thus, it is important to further understand the interaction between the RV and renal function. RV adaptation is critical to long-term survival in patients with PAH. The RV is also known for its remarkable capacity to recover once the aggravating factor is addressed or mitigated. However, less is known about the renal potential for recovery following the resolution of chronic RV failure. In this review, we provide an overview of the intricate relationship between RV dysfunction and the subsequent development of CRS, with a particular emphasis on PAH. Additionally, we summarize potential RV-targeted therapies and their potential beneficial impact on renal function.

Aqueous Assembly of Oxide and Fluoride Nanoparticles into 3D Microassemblies.

We demonstrate rapid [∼mm3/(h·L)] organic ligand-free self-assembly of three-dimensional, >50 µm single-domain microassemblies containing up to 107 individual aligned nanoparticles through a scalable aqueous process. Organization and alignment of aqueous solution-dispersed nanoparticles are induced by decreasing their pH-dependent surface charge without organic ligands, which could be temperature-sensitive or infrared light absorbing. This process is exhibited by transforming both dispersed iron oxide hydroxide nanorods and lithium yttrium fluoride nanoparticles into high packing density microassemblies. The approach is generalizable to nanomaterials with pH-dependent surface charge (e.g., oxides, fluorides, and sulfides) for applications requiring long-range alignment of nanostructures as well as high packing density.

Mouse Model of Chromosome 15q13.3 Microdeletion Syndrome Demonstrates Features Related to Autism Spectrum Disorder.

The chromosome 15q13.3 microdeletion is a pathogenic copy number variation conferring epilepsy, intellectual disability, schizophrenia, and autism spectrum disorder (ASD). We generated mice carrying a deletion of 1.2 Mb homologous to the 15q13.3 microdeletion in human patients. Here, we report that mice with a heterozygous deletion on a C57BL/6 background (D/+ mice) demonstrated phenotypes including enlarged/heavier brains (macrocephaly) with enlarged lateral ventricles, decreased social interactions, increased repetitive grooming behavior, reduced ultrasonic vocalizations, decreased auditory-evoked gamma band EEG, and reduced event-related potentials. D/+ mice had normal body weight, activity levels, sensory gating, and cognitive abilities and no signs of epilepsy/seizures. Our results demonstrate that D/+ mice represent ASD-related phenotypes associated with 15q13.3 microdeletion syndrome. Further investigations using this chromosome-engineered mouse model may uncover the common mechanism(s) underlying ASD and other neurodevelopmental/psychiatric disorders representing the 15q13.3 microdeletion syndrome, including epilepsy, intellectual disability, and schizophrenia. SIGNIFICANCE STATEMENT: Recently discovered pathologic copy number variations (CNVs) from patients with neurodevelopmental/psychiatric disorders show very strong penetrance and thus are excellent candidates for mouse models of disease that can mirror the human genetic conditions with high fidelity. A 15q13.3 microdeletion in humans results in a range of neurodevelopmental/psychiatric disorders, including epilepsy, intellectual disability, schizophrenia, and autism spectrum disorder (ASD). The disorders conferred by a 15q13.3 microdeletion also have overlapping genetic architectures and comorbidity in other patient populations such as those with epilepsy and schizophrenia/psychosis, as well as schizophrenia and ASD. We generated mice carrying a deletion of 1.2 Mb homologous to the 15q13.3 microdeletion in human patients, which allowed us to investigate the potential causes of neurodevelopmental/psychiatric disorders associated with the CNV.

Gastrin-releasing peptide contributes to the regulation of adult hippocampal neurogenesis and neuronal development.

In the postnatal hippocampus, newly generated neurons contribute to learning and memory. Disruptions in neurogenesis and neuronal development have been linked to cognitive impairment and are implicated in a broad variety of neurological and psychiatric disorders. To identify putative factors involved in this process, we examined hippocampal gene expression alterations in mice possessing a heterozygous knockout of the calcium/calmodulin-dependent protein kinase II alpha heterozygous knockout gene (CaMK2α-hKO), an established model of cognitive impairment that also displays altered neurogenesis and neuronal development. Using this approach, we identified gastrin-releasing peptide (GRP) as the most dysregulated gene. In wild-type mice, GRP labels NeuN-positive neurons, the lone exception being GRP-positive, NeuN-negative cells in the subgranular zone, suggesting GRP expression may be relevant to neurogenesis and/or neuronal development. Using a model of in vitro hippocampal neurogenesis, we determined that GRP signaling is essential for the continued survival and development of newborn neurons, both of which are blocked by transient knockdown of GRP's cognate receptor (GRPR). Furthermore, GRP appears to negatively regulate neurogenesis-associated proliferation in neural stem cells both in vitro and in vivo. Intracerebroventricular infusion of GRP resulted in a decrease in immature neuronal markers, increased cAMP response element-binding protein (CREB) phosphorylation, and decreased neurogenesis. Despite increased levels of GRP mRNA, CaMK2α-hKO mutant mice expressed reduced levels of GRP peptide. This lack of GRP may contribute to the elevated neurogenesis and impaired neuronal development, which are reversed following exogenous GRP infusion. Based on these findings, we hypothesize that GRP modulates neurogenesis and neuronal development and may contribute to hippocampus-associated cognitive impairment.

Liquid crystal Janus emulsion droplets: preparation, tumbling, and swimming.

This study introduces liquid crystal (LC) Janus droplets. We describe a process for the preparation of these droplets, which consist of nematic LC and polymer compartments. The process employs solvent-induced phase separation in emulsion droplets generated by microfluidics. The droplet morphology was systematically investigated and demonstrated to be sensitive to the surfactant concentration in the background phase, the compartment volume ratio, and the possible coalescence of multiple Janus droplets. Interestingly, the combination of a polymer and an anisotropic LC introduces new functionalities into Janus droplets, and these properties lead to unusual dynamical behaviors. The different densities and solubilities of the two compartments produce gravity-induced alignment, tumbling, and directional self-propelled motion of Janus droplets. LC Janus droplets with remarkable optical properties and dynamical behaviors thus offer new avenues for applications of Janus colloids and active soft matter.

Patterns of Statin Therapy Use and Associated Outcomes in Older Veterans Across Kidney Function.

BACKGROUND: Despite significant morbidity and mortality related to atherosclerotic cardiovascular disease, to date, most major clinical trials studying the effects of statin therapy have excluded older adults. The objective of this analysis was to evaluate the effect of initiating statin therapy on incident dementia and mortality among individuals 75 years of age or older across the complete spectrum of kidney function. METHODS: We conducted a retrospective cohort study of 640,191 VA health system patients who turned 75 years of age between 2000 and 2018. Patients on statin therapy received the medication for an average of 6.3 years (standard deviation 4.6 years). The primary outcome of interest included incident dementia diagnosis during the study period. The secondary outcome was all-cause mortality. Cox proportional hazard analysis was used to evaluate the adjusted association of statin initiation with these outcomes. RESULTS: There was a higher rate of incident dementia in the No Statin group (4.7%) vs the Statin group (3.2%). Additionally, we observed a 22% all-cause mortality benefit associated with statin therapy. We did not observe a treatment effect with respect to primary or secondary outcomes across varying levels of kidney function. CONCLUSION: This large cohort study did not reveal an association between the initiation of statin therapy and incident dementia. A survival benefit was seen in statin users compared with nonusers. Prospective studies in more diverse populations including older adults will be needed to verify these findings.

The immature dentate gyrus represents a shared phenotype of mouse models of epilepsy and psychiatric disease.

OBJECTIVES: There is accumulating evidence to suggest psychiatric disorders, such as bipolar disorder and schizophrenia, share common etiologies, pathophysiologies, genetics, and drug responses with many of the epilepsies. Here, we explored overlaps in cellular/molecular, electrophysiological, and behavioral phenotypes between putative mouse models of bipolar disorder/schizophrenia and epilepsy. We tested the hypothesis that an immature dentate gyrus (iDG), whose association with psychosis in patients has recently been reported, represents a common phenotype of both diseases. METHODS: Behaviors of calcium/calmodulin-dependent protein kinase II alpha (α-CaMKII) heterozygous knock-out (KO) mice, which are a representative bipolar disorder/schizophrenia model displaying iDG, and pilocarpine-treated mice, which are a representative epilepsy model, were tested followed by quantitative polymerase chain reaction (qPCR)/immunohistochemistry for mRNA/protein expression associated with an iDG phenotype. In vitro electrophysiology of dentate gyrus granule cells (DG GCs) was examined in pilocarpine-treated epileptic mice. RESULTS: The two disease models demonstrated similar behavioral deficits, such as hyperactivity, poor working memory performance, and social withdrawal. Significant reductions in mRNA expression and immunoreactivity of the mature neuronal marker calbindin and concomitant increases in mRNA expression and immunoreactivity of the immature neuronal marker calretinin represent iDG signatures that are present in both mice models. Electrophysiologically, we have confirmed that DG GCs from pilocarpine-treated mice represent an immature state. A significant decrease in hippocampal α-CaMKII protein levels was also found in both models. CONCLUSIONS: Our data have shown iDG signatures from mouse models of both bipolar disorder/schizophrenia and epilepsy. The evidence suggests that the iDG may, in part, be responsible for the abnormal behavioral phenotype, and that the underlying pathophysiologies in epilepsy and bipolar disorder/schizophrenia are strikingly similar.

Stable cycling and excess capacity of a nanostructured Sn electrode based on Sn(CH3COO)2 confined within a nanoporous carbon scaffold.

A high capacity, electrochemically stable, nanostructured Sn electrode for Li ion battery anodes is described. This electrode utilizes a rigid, electrically conductive, nanoporous carbon aerogel scaffold by incorporating tin acetate, Sn(CH3COO)2, into the scaffold pore volume through melt infusion. Incorporation of the Sn(CH3COO)2 by melt infusion ensures a chemically stable contact with the scaffold. The mechanical rigidity of the pore volume confines the Sn to nanometer dimensions without sintering, leading to stable cycling. Separation of the synthesis of the scaffold from the loading with Sn(CH3COO)2 permits optimized division of the scaffold pore volume for expansion and electrolyte access during reaction with Li. Using this design, an electrode based on an aerogel with a 5 nm mode pore size was cycled over 300 times without degradation. In addition, after subtracting the contribution from the carbon scaffold, the capacity exceeded the theoretical capacity for Sn, due to an oxidation reaction occurring at 1.2 V. This excess capacity may be related to the solid-solid or solid-electrolyte interfaces in the electrode, possibly representing a new reversible Li ion reaction.

Reversible ligand exchange in a metal-organic framework (MOF): toward MOF-based dynamic combinatorial chemical systems.

Reversible benzene dicarboxylate/2-bromobenzene dicarboxylate ligand exchange has been studied in the cubic metal-organic framework MOF-5. Significant exchange (up to ∼50%), with continuous compositional variation, was observed using ex-situ (1)H NMR following treatment over ∼6 h at ∼85 °C in 10-40 mM ligand solutions. Exchange occurred without significant structural degradation as characterized by X-ray diffraction, nitrogen adsorption, and scanning electron microscopy. Solid-state (13)C NMR was used to show that exchanged ligands were incorporated into the framework lattice and not simply adsorbed within the pores. Exchange was found to be sensitive to the small free energy changes caused by the ligand concentration in the exchanging solution indicating that exchange is energetically nearly degenerate. This demonstration of reversible, nearly isoenergetic exchange indicates that mixed ligand MOFs could be developed as dynamic combinatorial chemical systems.

Observation of electron orbital signatures of single atoms within metal-phthalocyanines using atomic force microscopy.

Resolving the electronic structure of a single atom within a molecule is of fundamental importance for understanding and predicting chemical and physical properties of functional molecules such as molecular catalysts. However, the observation of the orbital signature of an individual atom is challenging. We report here the direct identification of two adjacent transition-metal atoms, Fe and Co, within phthalocyanine molecules using high-resolution noncontact atomic force microscopy (HR-AFM). HR-AFM imaging reveals that the Co atom is brighter and presents four distinct lobes on the horizontal plane whereas the Fe atom displays a "square" morphology. Pico-force spectroscopy measurements show a larger repulsion force of about 5 pN on the tip exerted by Co in comparison to Fe. Our combined experimental and theoretical results demonstrate that both the distinguishable features in AFM images and the variation in the measured forces arise from Co's higher electron orbital occupation above the molecular plane. The ability to directly observe orbital signatures using HR-AFM should provide a promising approach to characterizing the electronic structure of an individual atom in a molecular species and to understand mechanisms of certain chemical reactions.

Icosahedral platinum alloy nanocrystals with enhanced electrocatalytic activities.

This communication describes the synthesis of Pt-M (M = Au, Ni, Pd) icosahedral nanocrystals based on the gas reducing agent in liquid solution method. Both CO gas and organic surface capping agents play critical roles in stabilizing the icosahedral shape with {111} surfaces. Among the Pt-M alloy icosahedral nanocrystals generated, Pt(3)Ni had an impressive ORR specific activity of 1.83 mA/cm(2)(Pt) and 0.62 A/mg(Pt). Our results further show that the area-specific activity of icosahedral Pt(3)Ni catalysts was about 50% higher than that of the octahedral Pt(3)Ni catalysts (1.26 mA/cm(2)(Pt)), even though both shapes are bound by {111} facets. Density functional theory calculations and molecular dynamics simulations indicate that this improvement may arise from strain-induced electronic effects.

SREB2/GPR85, a schizophrenia risk factor, negatively regulates hippocampal adult neurogenesis and neurogenesis-dependent learning and memory.

SREB2/GPR85, a member of the super-conserved receptor expressed in brain (SREB) family, is the most conserved G-protein-coupled receptor in vertebrate evolution. Previous human and mouse genetic studies have indicated a possible link between SREB2 and schizophrenia. SREB2 is robustly expressed in the hippocampal formation, especially in the dentate gyrus, a structure with an established involvement in psychiatric disorders and cognition. However, the function of SREB2 in the hippocampus remains elusive. Here we show that SREB2 regulates hippocampal adult neurogenesis, which impacts on cognitive function. Bromodeoxyuridine incorporation and immunohistochemistry were conducted in SREB2 transgenic (Tg, over-expression) and knockout (KO, null-mutant) mice to quantitatively assay adult neurogenesis and newborn neuron dendritic morphology. Cognitive responses associated with adult neurogenesis alteration were evaluated in SREB2 mutant mice. In SREB2 Tg mice, both new cell proliferation and new neuron survival were decreased in the dentate gyrus, whereas an enhancement of new neuron survival occurred in SREB2 KO mouse dentate gyrus. Doublecortin staining revealed dendritic morphology deficits of newly generated neurons in SREB2 Tg mice. In a spatial pattern separation task, SREB2 Tg mice displayed a decreased ability to discriminate spatial relationships, whereas SREB2 KO mice had enhanced abilities in this task. Additionally, SREB2 Tg and KO mice had reciprocal phenotypes in a Y-maze working memory task. Our results indicate that SREB2 is a negative regulator of adult neurogenesis and consequential cognitive functions. Inhibition of SREB2 function may be a novel approach to enhance hippocampal adult neurogenesis and cognitive abilities to ameliorate core symptoms of psychiatric patients.

Entropy of cellulose dissolution in water and in the ionic liquid 1-butyl-3-methylimidazolim chloride.

The entropic driving forces of cellulose dissolution in water and in the ionic liquid 1-butyl-3-methylimidazolium chloride (BmimCl) are investigated via molecular dynamics simulations and the two-phase thermodynamic model. An atomistic model of cellulose was simulated at a dissociated state and a microfibril state to represent dissolution. The calculated values of entropy and internal energy changes between the two states inform the interplay of energetic and entropic driving forces in cellulose dissolution. In both water and BmimCl, we found that the entropy associated with the solvent degrees of freedom (DOF) decreases upon cellulose dissolution. However, solvent entropy reduction in BmimCl is much smaller than that in water and counteracts the entropy gain from the solute DOF to a much lesser extent. Solvent entropy reduction in water also plays a major role in making the free energy change of cellulose dissolution unfavorable at room temperature. In BmimCl, the interaction energies between solvent molecules and glucan chains and the total entropy change both contribute favorably to the dissolution free energy of cellulose. Calculations at different temperatures in the two solvents indicate that changes in total internal energy are a good indicator of the sign of the free energy change of cellulose dissolution.

Shape and composition-controlled platinum alloy nanocrystals using carbon monoxide as reducing agent.

The shape of metal alloy nanocrystals plays an important role in catalytic performances. Many methods developed so far in controlling the morphologies of nanocrystals are however limited by the synthesis that is often material and shape specific. Here we show using a gas reducing agent in liquid solution (GRAILS) method, different Pt alloy (Pt-M, M = Co, Fe, Ni, Pd) nanocrystals with cubic and octahedral morphologies can be prepared under the same kind of reducing reaction condition. A broad range of compositions can also be obtained for these Pt alloy nanocrystals. Thus, this GRAILS method is a general approach to the preparation of uniform shape and composition-controlled Pt alloy nanocrystals. The area-specific oxygen reduction reaction (ORR) activities of Pt(3)Ni catalysts at 0.9 V are 0.85 mA/cm(2)(Pt) for the nanocubes, and 1.26 mA/cm(2)(Pt) for the nanooctahedra. The ORR mass activity of the octahedral Pt(3)Ni catalyst reaches 0.44 A/mg(Pt).

Dissecting force interactions in cellulose deconstruction reveals the required solvent versatility for overcoming biomass recalcitrance.

Pretreatment for deconstructing the multifaceted interaction network in crystalline cellulose is a limiting step in making fuels from lignocellulosic biomass. Not soluble in water and most organic solvents, cellulose was found to dissolve in certain classes of ionic liquids (ILs). To elucidate the underlying mechanisms, we simulated cellulose deconstruction by peeling off an 11-residue glucan chain from a cellulose microfibril and computed the free-energy profile in water and in 1-butyl-3-methylimidazolium chloride (BmimCl) IL. For this deconstruction process, the calculated free-energy cost/reduction in water/BmimCl is ∼2 kcal/mol per glucose residue, respectively. To unravel the molecular origin of solvent-induced differences, we devised a coarse graining scheme to dissect force interactions in simulation models by a force-matching method. The results establish that solvent-glucan interactions are dependent on the deconstruction state of cellulose. Water couples to the hydroxyl and side-chain groups of glucose residues more strongly in the peeled-off state but lacks driving forces to interact with sugar rings and linker oxygens. Conversely, BmimCl demonstrates versatility in targeting glucose residues in cellulose. Anions strongly interact with hydroxyl groups, and the coupling of cations to side chains and linker oxygens is stronger in the peeled-off state. Other than enhancing anion-hydroxyl group coupling, coarse-grain analysis of force interactions identifies configuring cations to target side chains and linker oxygens as a useful design strategy for pretreatment ILs. Furthermore, the state dependence of solvent-glucan interactions highlights specific stabilization and/or frustration of the different structure states of cellulose as important design parameters for pretreatment solvents.

Dual Component Passive Icephobic Coatings with Micron-Scale Phase-Separated 3D Structures.

A passive icephobic coating (τice < 20 kPa) is an enabling technology to many industries, including aerospace and energy and power generation, with recent efforts in materials research identifying strategies to achieve this low adhesion threshold. To better meet this need, we have combined low surface energy perfluoropolyether (PFPE) and hydrophilic poly(ethylene glycol) (PEG) species in a segmented polyurethane thermoplastic elastomer. Coating microstructure presents a segregated 3D morphology at the micron-scale (1-100 µm) with discrete PFPE and continuous PEG phases self-similar through the thickness. Spray application produces a solid, mechanically tough film free of additive fluids or sacrificial elements, demonstrating exceptional ice adhesion reduction up to 1000× lower versus aluminum (τice < 1 kPa), as measured under environmentally realistic accretion and centrifugal test shedding conditions. Finally, the modular nature of the synthetic system allows PEG and PFPE to be exchanged for poly(tetramethylene oxide) to investigate performance drivers.

Hierarchical carbon foams with independently tunable mesopore and macropore size distributions.

Hierarchical carbon foams with independently tunable mesopore and macropore size distributions were formed in a high internal phase emulsion (HIPE) template. The HIPE consists of an internal oil phase that controls the macropore dimensions and an aqueous resorcinol-formaldehyde precursor solution external phase that directs the mesopore size distribution. Once the emulsion is formed, the precursor solution is cured, fluid elements are extracted from the monolith via solvent exchange, and then the sample is pyrolyzed to create a hierarchical open-cell foam consisting of macropores with mesoporous carbon xerogel walls. Both mesopore and macropore size distributions may be independently tuned by changing the synthesis parameters. These samples have a peak in the mesopore size distribution that may be tuned to between 5 and 8 nm and macropore average diameters that may be tuned to between 0.7 and 2.1 microm. Furthermore, the 0.7 and 2.1 microm average diameter macropores have 0.18 and 0.53 microm diameter macropore windows between adjacent pores, respectively. Pore volumes up to 5.26 cm(3)/g and electrical conductivities as high as 0.34 S/cm are observed after 1200 degrees C carbonization of the framework. These foams may have potential applications as 3-D current collectors in batteries and as fuel cell catalyst supports.

Fabrication and hydrogen sorption behaviour of nanoparticulate MgH2 incorporated in a porous carbon host.

Nanoparticles of MgH2 incorporated in a mesoporous carbon aerogel demonstrated accelerated hydrogen exchange kinetics but no thermodynamic change in the equilibrium hydrogen pressure. Aerogels contained pores from <2 to approximately 30 nm in diameter with a peak at 13 nm in the pore size distribution. Nanoscale MgH2 was fabricated by depositing wetting layers of nickel or copper on the aerogel surface, melting Mg into the aerogel, and hydrogenating the Mg to MgH2. Aerogels with metal wetting layers incorporated 9-16 wt% MgH2, while a metal free aerogel incorporated only 3.6 wt% MgH2. The improved hydrogen sorption kinetics are due to both the aerogel limiting the maximum MgH(2) particle diameter and a catalytic effect from the Ni and Cu wetting layers. At 250 degrees C, MgH2 filled Ni decorated and Cu decorated carbon aerogels released H(2) at 25 wt% h(-1) and 5.5 wt% h(-1), respectively, while a MgH(2) filled aerogel without catalyst desorbed only 2.2 wt% h(-1) (all wt% h(-1) values are with respect to MgH2 mass). At the same temperature, MgH2 ball milled with synthetic graphite desorbed only 0.12 wt% h(-1), which demonstrated the advantage of incorporating nanoparticles in a porous host.

The kinetic enhancement of hydrogen cycling in NaAlH(4) by melt infusion into nanoporous carbon aerogel.

Enhanced kinetic performance and reversibility have been achieved with uncatalyzed NaAlH4 by incorporation into nanoporous carbon aerogel. Aerogel with a pore size distribution peaked at 13 nm and a pore volume of 0.8 cm(3) g(-1) was filled with NaAlH4 to 94% capacity by melt infusion at 189 degrees C under 183 bar H(2) gas overpressure. Dehydrogenation to NaH + Al with reasonable kinetics was accomplished at 150 degrees C, well below the NaAlH4 melting temperature (183 degrees C), compared to hydrogen release above 230 degrees C for bulk uncatalyzed NaAlH4. Uncatalyzed bulk samples did not rehydrogenate under laboratory conditions, whereas NaAlH4 in a carbon aerogel host was readily rehydrogenated at approximately 160 degrees C and 100 bar H(2) to approximately 85% of its initial capacity. Ball-milled NaAlH4 catalyzed with 4 mol% TiCl3 showed somewhat better kinetics compared to the infused aerogel; nevertheless, the large kinetic enhancement obtained by incorporation into carbon aerogel, even in the absence of a catalyst, demonstrates the substantial benefit of confining the NaAlH4 to nanoscale dimensions.

The synthesis and hydrogen storage properties of a MgH(2) incorporated carbon aerogel scaffold.

A new approach to the incorporation of MgH2 in the nanometer-sized pores of a carbon aerogel scaffold was developed, by infiltrating the aerogel with a solution of dibutylmagnesium (MgBu2) precursor, and then hydrogenating the incorporated MgBu2 to MgH2. The resulting impregnated material showed broad x-ray diffraction peaks of MgH2. The incorporated MgH2 was not visible using a transmission electron microscope, which indicated that the incorporated hydride was nanosized and confined in the nanoporous structure of the aerogel. The loading of MgH2 was determined as 15-17 wt%, of which 75% is reversible over ten cycles. Incorporated MgH2 had >5 times faster dehydrogenation kinetics than ball-milled activated MgH2, which may be attributed to the particle size of the former being smaller than that of the latter. Cycling tests of the incorporated MgH(2) showed that the dehydrogenation kinetics are unchanged over four cycles. Our results demonstrate that confinement of metal hydride materials in a nanoporous scaffold is an efficient way to avoid aggregation and improve cycling kinetics for hydrogen storage materials.