Association between birth weight and insulin resistance in US adolescents: A retrospective cohort study exploring the role of concurrent body mass index.

BACKGROUND AND AIMS: This study aimed to investigate the association between birth weight (BW) and abnormal HOMA-IR in US adolescents aged 12-15 years. The role of concurrent body mass index (BMI) in adolescence was also examined. METHODS AND RESULTS: This retrospective cohort study included 3429 participants from NHANES with data in 1999-2020. HOMA-IR ≥2.3 was considered abnormal. Participants were classified as low (LBW; <2.5 kg), normal (NBW; 2.5-4.0 kg), or high (HBW; >4.0 kg) BW. Logistic regression was used to explore the association between BW and HOMA-IR. Mediation analysis was used to examine whether BMI z-score in adolescence mediated the association between BW and HOMA-IR. Compared with those in NBW, the odds ratios (95 % CI) of abnormal HOMA-IR in LBW and HBW groups were 1.26 (0.99-1.60), and 0.62 (0.47-0.83) respectively. The association between BW and abnormal HOMA-IR was consistent in all subgroups with no significant interactions. Mediation analysis showed that BW is associated with lower risk of HOMA-IR directly, but with higher risk indirectly via BMI in adolescence. CONCLUSION: There was a negative linear relationship between BW and the prevalence of abnormal HOMA-IR in adolescents aged 12-15 independent of concurrent BMI. Children who were born with LBW but had high BMI in adolescence were of particularly higher risk of insulin resistance.

Fetal Hyperthyroidism with Maternal Hypothyroidism: Two Cases of Intrauterine Therapy.

Fetal hyperthyroidism can occur secondary to maternal autoimmune hyperthyroidism. The thyroid-stimulating hormone receptor antibody (TRAb) transferred from the mother to the fetus stimulates the fetal thyroid and causes fetal thyrotoxicosis. Fetuses with this condition are difficult to detect, especially after maternal Graves disease therapy. Here, we present two cases of fetal hyperthyroidism with maternal hypothyroidism and review the assessment and intrauterine therapy for fetal hyperthyroidism. Both women were referred at 22+ and 23+ weeks of gestation with abnormal ultrasound findings, including fetal heart enlargement, pericardial effusion, and fetal tachycardia. Both women had a history of Graves disease while in a state of hypothyroidism with a high titer of TRAb. A sonographic examination showed a diffusely enlarged fetal thyroid with abundant blood flow. Invasive prenatal testing revealed no significant chromosomal aberration. Low fetal serum TSH and high TRAb levels were detected in the cord blood. Fetal hyperthyroidism was considered, and maternal oral methimazole (MMI) was administered as intrauterine therapy, with the slowing of fetal tachycardia, a reduction in fetal heart enlargement, and thyroid hyperemia. During therapy, maternal thyroid function was monitored, and the dosage of maternal levothyroxine was adjusted accordingly. Both women delivered spontaneously at 36+ weeks of gestation, and neonatal hyperthyroidism was confirmed in both newborns. After methimazole and propranolol drug treatment with levothyroxine for 8 and 12 months, both babies became euthyroid with normal growth and development.

Constructing imine groups on the surface of Cu1/Pd(111) as a novel strategy for CO2 hydrogenation to methanol.

Developing a promising strategy to improve the limited selectivity and activity of traditional Pd-Cu bimetallic catalysts for CO2 hydrogenation to methanol (CH3OH) remains a grand challenge. By using density functional theory calculations, we discovered that introducing imine groups on the Cu1/Pd(111) surface through a condensation reaction of aldehydes and amines is an intriguing approach for simultaneously enhancing the selectivity and activity of Cu1/Pd(111) for CO2 hydrogenation to CH3OH. The imine groups formed by amino reactions with acrolein on the Cu1/Pd(111) surface (C3H4O@NH2-Cu1/Pd(111)) improved the turnover frequency (TOF). The imine group optimized the electronic structure of active sites and increased electron transfer to the anti-bonding orbital of CO2, facilitating the activity of C3H4O@NH2-Cu1/Pd(111) for CO2 hydrogenation to CH3OH. Besides, the inhibition of CO by-products and the low desorption energy of CH3OH were responsible for the high selectivity of C3H4O@NH2-Cu1/Pd(111) for CH3OH. This work advances our understanding of the role of imines in catalysis and provides a new strategy for designing excellent functional group-modified catalysts for the hydrogenation of CO2 to CH3OH.

A DFT study of boron nitride-confined nickel single atoms for the oxidation of methane to methanol.

Direct oxidation of methane to methanol (DMTM) remains an economically tantalizing but fundamentally challenging goal because of the highly stable C-H bonds. By using density functional theory calculations, we investigated the catalytic properties of single transition metals (Fe, Pd, Ni) supported on O-doped BN in different coordination environments for DMTM. The results indicated that embedding Ni into O-doped BN via two N atoms and one O atom coordination (Ni1/O1N2-BN) was an efficient option for DMTM. Ni1/O1N2-BN was capable of effectively activating the strong C-H bonds of CH4 by generating key Ni-O intermediates. Besides, Ni1/O1N2-BN also exhibited high selectivity for CH3OH owing to the inhibition of CH2 competitive species and low desorption energy of CH3OH. Furthermore, the excellent thermal stability of Ni1/O1N2-BN was verified via ab initio molecular dynamics calculations at 500 K for 10 ps. This work provides a new insight into the fundamental understanding and materials design of high-efficiency catalysts for DMTM.

Direct conversion of methane to methanol on boron nitride-supported copper single atoms.

Direct conversion of methane to methanol (DMTM) under mild conditions is one of the most attractive and challenging processes in catalysis. By using density functional theory calculations, we systematically investigate the catalytic performance of Cu single atoms supported on O-doped BN in different coordination environments as a DMTM catalyst. Computations demonstrate that Cu coordinated with one O atom and two N atoms on O-doped BN (Cu1/O1N2-BN) exhibited the highest catalytic activity for DMTM at room temperature with quite a low rate-determining step energy barrier of 0.46 eV. The moderate adsorption of *O atoms, selective stabilization of CH3 species, and easy desorption of CH3OH are responsible for the unique activity of Cu1/O1N2-BN for DMTM. In addition, the adsorption free energy of *O atoms produced by the dissociation of O-donor molecules is a suitable descriptor for predicting the catalytic performance of materials and accelerating the discovery of catalysts for DMTM. This work opens new avenues to develop highly efficient catalysts for DMTM.

Photocatalytic Conversion of Methane: Recent Advancements and Prospects.

Abundant and affordable methane is not only a high-quality fossil fuel, it is also a raw material for the synthesis of value-added chemicals. Solar-energy-driven conversion of methane offers a promising approach to directly transform methane to valuable energy sources under mild conditions, but remains a great challenge at present. In this Review, recent advances in the photocatalytic conversion of methane are systematically summarized. Insights into the construction of effective semiconductor-based photocatalysts from the perspective of light-absorption units and active centers are highlighted and discussed in detail. The performance of various photocatalysts in the conversion of methane is presented, with the photooxidation classified according to the oxidant systems. Lastly, challenges and future perspectives in the photocatalytic oxidation of methane are described.

Enhanced uranium photoreduction on Ti3C2Tx MXene by modulation of surface functional groups and deposition of plasmonic metal nanoparticles.

Photocatalytic reduction of soluble hexavalent uranium (U(VI)) is a novel and efficient avenue to enriching U(VI), where the free U(VI) is firstly bound on the surface of photocatalysts and then reduced to insoluble tetravalent uranium (U(IV)) by photoelectrons. Therefore, constructing the efficient U(VI) binding sites on photocatalysts is an efficient strategy to boost catalytic activity toward U(VI) photoreduction. Herein, we successfully constructed an efficient catalyst for U(VI) photoreduction by depositing Ag nanoparticles on Ti3C2Tx MXene with abundant U(VI) binding sites (Ag/Ti3C2Tx-O). Impressively, the U(VI) extracting mass over Ag/Ti3C2Tx-O under light reached up to 1257.6 mg/g in 120 min, which was almost 11 times as high as that without light. Further mechanistic studies indicated that the U(VI) binding sites on Ti3C2Tx MXene in Ag/Ti3C2Tx-O were beneficial to the reduction of U(VI) by significantly decreasing its reduction potential. More importantly, hot electrons generated by Ag nanoparticles were transferred into the binding sites to easily reduce the bound U(VI), resulting in the remarkable performance of Ag/Ti3C2Tx-O during U(VI) enrichment.

Copper-Stabilized P'2-Type Layered Manganese Oxide Cathodes for High-Performance Sodium-Ion Batteries.

Layered sodium manganese oxides are promising low-cost and high-capacity cathode materials for commercialization of sodium-ion batteries (SIBs). P'2-type Na0.67MnO2 with an orthorhombic structure has been considered as a significant candidate for SIBs. However, the Jahn-Teller distortion and undesired phase transitions will lead to poor structural stability and unsatisfactory cycling performance. Herein, a systematic investigation on partially copper-doped P'2-type Na0.67CuxMn1-xO2 (x = 0, 0.05, 0.1, and 0.2) series as cathodes for SIBs reveals the relationship between doping concentrations and Na storage properties. With proper copper content, P'2 Na0.67Cu0.1Mn0.9O2 exhibits a suppressed Jahn-Teller effect as well as relatively less phase transitions, which can deliver a high specific capacity of 222.7 mA h g-1 at 10 mA g-1 within 1.5-4.2 V, with a capacity retention of 76% at 1 A g-1 after 300 cycles. The electrochemical mechanism is systematically investigated via in situ X-ray diffraction observations and density functional theory calculations, which provide fundamental guidelines for developing high-performance cathodes for SIBs.

Copper-Based Plasmonic Catalysis: Recent Advances and Future Perspectives.

With the capability of inducing intense electromagnetic field, energetic charge carriers, and photothermal effect, plasmonic metals provide a unique opportunity for efficient light utilization and chemical transformation. Earth-abundant low-cost Cu possesses intense and tunable localized surface plasmon resonance from ultraviolet-visible to near infrared region. Moreover, Cu essentially exhibits remarkable catalytic performance toward various reactions owing to its intriguing physical and chemical properties. Coupling with light-harvesting ability and catalytic function, plasmonic Cu serves as a promising platform for efficient light-driven chemical reaction. Herein, recent advancements of Cu-based plasmonic photocatalysis are systematically summarized, including designing and synthetic strategies for Cu-based catalysts, plasmonic catalytic performance, and mechanistic understanding over Cu-based plasmonic catalysts. What's more, approaches for the enhancement of light utilization efficiency and construction of active centers on Cu-based plasmonic catalysts are highlighted and discussed in detail, such as morphology and size control, regulation of electronic structure, defect and strain engineering, etc. Remaining challenges and future perspectives for further development of Cu-based plasmonic catalysis are also proposed.

Modulating oxygen coverage of Ti3C2Tx MXenes to boost catalytic activity for HCOOH dehydrogenation.

As a promising hydrogen carrier, formic acid (HCOOH) is renewable, safe and nontoxic. Although noble-metal-based catalysts have exhibited excellent activity in HCOOH dehydrogenation, developing non-noble-metal heterogeneous catalysts with high efficiency remains a great challenge. Here, we modulate oxygen coverage on the surface of Ti3C2Tx MXenes to boost the catalytic activity toward HCOOH dehydrogenation. Impressively, Ti3C2Tx MXenes after treating with air at 250 °C (Ti3C2Tx-250) significantly increase the amount of surface oxygen atoms without the change of crystalline structure, exhibiting a mass activity of 365 mmol·g-1·h-1 with 100% of selectivity for H2 at 80 °C, which is 2.2 and 2.0 times that of commercial Pd/C and Pt/C, respectively. Further mechanistic studies demonstrate that HCOO* is the intermediate in HCOOH dehydrogenation over Ti3C2Tx MXenes with different coverages of surface oxygen atoms. Increasing the oxygen coverage on the surface of Ti3C2Tx MXenes not only promotes the conversion from HCOO* to CO2* by lowering the energy barrier, but also weakens the adsorption energy of CO2 and H2, thus accelerating the dehydrogenation of HCOOH.

Anchoring Pt Single Atoms on Te Nanowires for Plasmon-Enhanced Dehydrogenation of Formic Acid at Room Temperature.

Formic acid (HCOOH), as a promising hydrogen carrier, is renewable, safe, and nontoxic. However, the catalytic dehydrogenation of HCOOH is typically conducted at elevated temperature. Here, HCOOH decomposition is successfully achieved for hydrogen production on the developed Pt single atoms modified Te nanowires with the Pt mass loading of 1.1% (1.1%Pt/Te) at room temperature via a plasmon-enhanced catalytic process. Impressively, 1.1%Pt/Te delivers 100% selectivity for hydrogen and the highest turnover frequency number of 3070 h-1 at 25 °C, which is significantly higher than that of Pt single atoms and Pt nanoclusters coloaded Te nanowires, Pt nanocrystals decorated Te nanowires, and commercial Pt/C. A plasmonic hot-electron driven mechanism rather than photothermal effect domains the enhancement of catalytic activity for 1.1%Pt/Te under light. The transformation of HCOO* to CO2 δ -* on Pt atoms is proved to be the rate-determining step by further mechanistic studies. 1.1%Pt/Te exhibits tremendous catalytic activity toward the decomposition of HCOOH owing to its plasmonic hot-electron driven mechanism, which efficiently stimulates the rate-determining step. In addition, hot electrons generated by the Te atoms nearby Pt single atoms are regarded to directly inject into the reactants adsorbed and activated on Pt single atoms.

In2O3 Nanocrystals for CO2 Fixation: Atomic-Level Insight into the Role of Grain Boundaries.

N-functionalization of amines with CO2 and H2 is one of the most important processes to make use of CO2. Although noble metal-based catalysts with remarkable performance have been widely used in this process, developing efficient non-noble-metal-based catalysts remains a grand challenge. Herein, we report In2O3 nanocrystals with high density of grain boundaries (HGB-In2O3), which show excellent activity toward methylation of amines. Impressively, HGB-In2O3 achieved the optimal yield of 82.7% for N,N-dimethylaniline with a mass activity of 21.2 mmol·g-1h-1 in methylation of N-methylaniline, comparable to noble-metal-based catalysts. As a bonus, HGB-In2O3 held noticeable stability, remarkable selectivity, and comprehensive applicability. Further mechanistic studies revealed that the presence of high density of grain boundaries not only facilitated the adsorption and activation of CO2 to generate CH3OH as the intermediate but also enhanced the activation of N-H bond in amines, contributing to the attractive activity of HGB-In2O3 toward methylation of amines.

Pt Single Atoms Embedded in the Surface of Ni Nanocrystals as Highly Active Catalysts for Selective Hydrogenation of Nitro Compounds.

Single-atom catalysts exhibit high selectivity in hydrogenation due to their isolated active sites, which ensure uniform adsorption configurations of substrate molecules. Compared with the achievement in catalytic selectivity, there is still a long way to go in exploiting the catalytic activity of single-atom catalysts. Herein, we developed highly active and selective catalysts in selective hydrogenation by embedding Pt single atoms in the surface of Ni nanocrystals (denoted as Pt1/Ni nanocrystals). During the hydrogenation of 3-nitrostyrene, the TOF numbers based on surface Pt atoms of Pt1/Ni nanocrystals reached ∼1800 h-1 under 3 atm of H2 at 40 °C, much higher than that of Pt single atoms supported on active carbon, TiO2, SiO2, and ZSM-5. Mechanistic studies reveal that the remarkable activity of Pt1/Ni nanocrystals derived from sufficient hydrogen supply because of spontaneous dissociation of H2 on both Pt and Ni atoms as well as facile diffusion of H atoms on Pt1/Ni nanocrystals. Moreover, the ensemble composed of the Pt single atom and nearby Ni atoms in Pt1/Ni nanocrystals leads to the adsorption configuration of 3-nitrostyrene favorable for the activation of nitro groups, accounting for the high selectivity for 3-vinylaniline.

Synergetic interaction between neighbouring platinum monomers in CO2 hydrogenation.

Exploring the interaction between two neighbouring monomers has great potential to significantly raise the performance and deepen the mechanistic understanding of heterogeneous catalysis. Herein, we demonstrate that the synergetic interaction between neighbouring Pt monomers on MoS2 greatly enhanced the CO2 hydrogenation catalytic activity and reduced the activation energy relative to isolated monomers. Neighbouring Pt monomers were achieved by increasing the Pt mass loading up to 7.5% while maintaining the atomic dispersion of Pt. Mechanistic studies reveal that neighbouring Pt monomers not only worked in synergy to vary the reaction barrier, but also underwent distinct reaction paths compared with isolated monomers. Isolated Pt monomers favour the conversion of CO2 into methanol without the formation of formic acid, whereas CO2 is hydrogenated stepwise into formic acid and methanol for neighbouring Pt monomers. The discovery of the synergetic interaction between neighbouring monomers may create a new path for manipulating catalytic properties.

Supported Rhodium Catalysts for Ammonia-Borane Hydrolysis: Dependence of the Catalytic Activity on the Highest Occupied State of the Single Rhodium Atoms.

Supported metal nanocrystals have exhibited remarkable catalytic performance in hydrogen generation reactions, which is influenced and even determined by their supports. Accordingly, it is of fundamental importance to determine the direct relationship between catalytic performance and metal-support interactions. Herein, we provide a quantitative profile for exploring metal-support interactions by considering the highest occupied state in single-atom catalysts. The catalyst studied consisted of isolated Rh atoms dispersed on the surface of VO2 nanorods. It was observed that the activation energy of ammonia-borane hydrolysis changed when the substrate underwent a phase transition. Mechanistic studies indicate that the catalytic performance depended directly on the highest occupied state of the single Rh atoms, which was determined by the band structure of the substrates. Other metal catalysts, even with non-noble metals, that exhibited significant catalytic activity towards NH3 BH3 hydrolysis were rationally designed by adjusting their highest occupied states.

Integration of Quantum Confinement and Alloy Effect to Modulate Electronic Properties of RhW Nanocrystals for Improved Catalytic Performance toward CO2 Hydrogenation.

The d-band center and surface negative charge density generally determine the adsorption and activation of CO2, thus serving as important descriptors of the catalytic activity toward CO2 hydrogenation. Herein, we engineered the d-band center and negative charge density of Rh-based catalysts by tuning their dimensions and introducing non-noble metals to form an alloy. During the hydrogenation of CO2 into methanol, the catalytic activity of Rh75W25 nanosheets was 5.9, 4.0, and 1.7 times as high as that of Rh nanoparticles, Rh nanosheets, and Rh73W27 nanoparticles, respectively. Mechanistic studies reveal that the remarkable activity of Rh75W25 nanosheets is owing to the integration of quantum confinement and alloy effect. Specifically, the quantum confinement in one dimension shifts up the d-band center of Rh75W25 nanosheets, strengthening the adsorption of CO2. Moreover, the alloy effect not only promotes the activation of CO2 to form CO2δ- but also enhances the adsorption of intermediates to facilitate further hydrogenation of the intermediates into methanol.

Integration of Photothermal Effect and Heat Insulation to Efficiently Reduce Reaction Temperature of CO2 Hydrogenation.

The photothermal effect is applied in CO2 hydrogenation to reduce the reaction temperature under illumination by encapsulating Pt nanocubes and Au nanocages into a zeolitic imidazolate framework (ZIF-8). Under illumination, the heat generated by the photothermal effect of Au nanocages is mainly insulated in the ZIF-8 to form a localized high-temperature region, thereby improving the catalytic activity of Pt nanocubes.

Atomic-level insights in optimizing reaction paths for hydroformylation reaction over Rh/CoO single-atom catalyst.

Rh-based heterogeneous catalysts generally have limited selectivity relative to their homogeneous counterparts in hydroformylation reactions despite of the convenience of catalyst separation in heterogeneous catalysis. Here, we develop CoO-supported Rh single-atom catalysts (Rh/CoO) with remarkable activity and selectivity towards propene hydroformylation. By increasing Rh mass loading, isolated Rh atoms switch to aggregated clusters of different atomicity. During the hydroformylation, Rh/CoO achieves the optimal selectivity of 94.4% for butyraldehyde and the highest turnover frequency number of 2,065 h-1 among the obtained atomic-scale Rh-based catalysts. Mechanistic studies reveal that a structural reconstruction of Rh single atoms in Rh/CoO occurs during the catalytic process, facilitating the adsorption and activation of reactants. In kinetic view, linear products are determined as the dominating products by analysing reaction paths deriving from the two most stable co-adsorbed configurations. As a bridge of homogeneous and heterogeneous catalysis, single-atom catalysts can be potentially applied in other industrial reactions.

Pt3 Co Octapods as Superior Catalysts of CO2 Hydrogenation.

As the electron transfer to CO2 is a critical step in the activation of CO2 , it is of significant importance to engineer the electronic properties of CO2 hydrogenation catalysts to enhance their activity. Herein, we prepared Pt3 Co nanocrystals with improved catalytic performance towards CO2 hydrogenation to methanol. Pt3 Co octapods, Pt3 Co nanocubes, Pt octapods, and Pt nanocubes were tested, and the Pt3 Co octapods achieved the best catalytic activity. Both the presence of multiple sharp tips and charge transfer between Pt and Co enabled the accumulation of negative charges on the Pt atoms in the vertices of the Pt3 Co octapods. Moreover, infrared reflection absorption spectroscopy confirmed that the high negative charge density at the Pt atoms in the vertices of the Pt3 Co octapods promotes the activation of CO2 and accordingly enhances the catalytic activity.

Ratio-controlled synthesis of CuNi octahedra and nanocubes with enhanced catalytic activity.

Non-noble bimetallic nanocrystals (NCs) have been widely explored due to not only their low cost and abundant content in the Earth's crust but also their outstanding performance in catalytic reactions. However, controllable synthesis of non-noble alloys remains a significant challenge. Here we report a facile synthesis of CuNi octahedra and nanocubes with controllable shapes and tunable compositions. Its success relies on the use of borane morpholine as a reducing agent, which upon decomposition generates a burst of H2 molecules to induce rapid formation of the nuclei. Specifically, octahedra switched to nanocubes with an increased amount of borane morpholine. In addition, the ratio of CuNi NCs could be facilely tuned by changing the molar ratio of both precursors. The obtained CuNi NCs exhibited high activity in aldehyde-alkyne-amine coupling reactions, and their performance is strongly facet- and composition-dependent due to the competition of the surface energy (enhanced by increasing the percent of Ni) and active sites (derived from Cu atoms).