Development of neonatal connectome dynamics and its prediction for cognitive and language outcomes at age 2.

The functional brain connectome is highly dynamic over time. However, how brain connectome dynamics evolves during the third trimester of pregnancy and is associated with later cognitive growth remains unknown. Here, we use resting-state functional Magnetic Resonance Imaging (MRI) data from 39 newborns aged 32 to 42 postmenstrual weeks to investigate the maturation process of connectome dynamics and its role in predicting neurocognitive outcomes at 2 years of age. Neonatal brain dynamics is assessed using a multilayer network model. Network dynamics decreases globally but increases in both modularity and diversity with development. Regionally, module switching decreases with development primarily in the lateral precentral gyrus, medial temporal lobe, and subcortical areas, with a higher growth rate in primary regions than in association regions. Support vector regression reveals that neonatal connectome dynamics is predictive of individual cognitive and language abilities at 2  years of age. Our findings highlight network-level neural substrates underlying early cognitive development.

Comprehensive understanding of electron mobility and superior performance in sub-10 nm DG ML tetrahex-GeC2 n-type MOSFETs.

In this study, we have investigated the electron mobility of monolayered (ML) tetrahex-GeC2 by solving the linearized Boltzmann transport equation (BTE) with the normalized full-band relaxation time approximation (RTA) using density functional theory (DFT). Contrary to what the deformation potential theory (DPT) suggested, the ZA acoustic mode was determined to be the most restrictive for electron mobility, not the LA mode. The electron mobility at 300 K is 803 cm2 (V s)-1, exceeding the 400 cm2 (V s)-1 of MoS2 which was calculated using the same method and measured experimentally. The ab initio quantum transport simulations were performed to assess the performance limits of sub-10 nm DG ML tetrahex-GeC2 n-type MOSFETs, including gate lengths (Lg) of 3 nm, 5 nm, 7 nm, and 9 nm, with the underlap (UL) effect considered for the first two. For both high-performance (HP) and low-power (LP) applications, their on-state currents (Ion) can meet the requirements of similar nodes in the ITRS 2013. In particular, the Ion is more remarkable for HP applications than that of the extensively studied MoS2. For LP applications, the Ion values at Lg of 7 and 9 nm surpass those of arsenene, known for having the largest Ion among 2D semiconductors. Subthreshold swings (SSs) as low as 69/53 mV dec-1 at an Lg of 9 nm were observed for HP/LP applications, and 73 mV dec-1 at an Lg of 5 nm for LP applications, indicating the excellent gate control capability. Moreover, the delay time τ and power dissipation (PDP) at Lg values of 3 nm, 5 nm, 7 nm, and 9 nm are all below the upper limits of the ITRS 2013 HP/LP proximity nodes and are comparable to or lower than those of typical 2D semiconductors. The sub-10 nm DG ML tetrahex-GeC2 n-type MOSFETs can be down-scaled to 9 nm and 5 nm for HP and LP applications, respectively, displaying desirable Ion, delay time τ, and PDP in the ballistic limit, making them a potential choice for sub-10 nm transistors.

Progressive Stabilization of Brain Network Dynamics during Childhood and Adolescence.

Functional brain networks require dynamic reconfiguration to support flexible cognitive function. However, the developmental principles shaping brain network dynamics remain poorly understood. Here, we report the longitudinal development of large-scale brain network dynamics during childhood and adolescence, and its connection with gene expression profiles. Using a multilayer network model, we show the temporally varying modular architecture of child brain networks, with higher network switching primarily in the association cortex and lower switching in the primary regions. This topographical profile exhibits progressive maturation, which manifests as reduced modular dynamics, particularly in the transmodal (e.g., default-mode and frontoparietal) and sensorimotor regions. These developmental refinements mediate age-related enhancements of global network segregation and are linked with the expression profiles of genes associated with the enrichment of ion transport and nucleobase-containing compound transport. These results highlight a progressive stabilization of brain dynamics, which expand our understanding of the neural mechanisms that underlie cognitive development.

2D Violet phosphorene with highly anisotropic mobility and its vdW heterojunction design for device applications.

Recently, the crystal structure of violet phosphorus and its monolayer violet phosphorene (VP) have been reconfirmed experimentally, and they were verified to be more thermally stable than their allotrope, black phosphorus. Here, we calculated the carrier mobility of monolayer VP using density functional theory. It is found that the carrier mobility is highly anisotropic and the hole mobility reaches 9.86 × 103 cm2 V-1 s-1 in the a-direction, endowing the potential application of VP in p-type semiconductor channel materials. Moreover, the Schottky barrier of the graphene/VP heterojunction turns into an ohmic contact when the electric field strength is >2 V nm-1. Therefore, VP and graphene/VP heterojunctions have potential prospects in electronic devices.

Individual Uniqueness in the Neonatal Functional Connectome.

The functional connectome is highly distinctive in adults and adolescents, underlying individual differences in cognition and behavior. However, it remains unknown whether the individual uniqueness of the functional connectome is present in neonates, who are far from mature. Here, we utilized the multiband resting-state functional magnetic resonance imaging data of 40 healthy neonates from the Developing Human Connectome Project and a split-half analysis approach to characterize the uniqueness of the functional connectome in the neonatal brain. Through functional connectome-based individual identification analysis, we found that all the neonates were correctly identified, with the most discriminative regions predominantly confined to the higher-order cortices (e.g., prefrontal and parietal regions). The connectivities with the highest contributions to individual uniqueness were primarily located between different functional systems, and the short- (0-30 mm) and middle-range (30-60 mm) connectivities were more distinctive than the long-range (>60 mm) connectivities. Interestingly, we found that functional data with a scanning length longer than 3.5 min were able to capture the individual uniqueness in the functional connectome. Our results highlight that individual uniqueness is present in the functional connectome of neonates and provide insights into the brain mechanisms underlying individual differences in cognition and behavior later in life.

Development and Emergence of Individual Variability in the Functional Connectivity Architecture of the Preterm Human Brain.

Individual variability in human brain networks underlies individual differences in cognition and behaviors. However, researchers have not conclusively determined when individual variability patterns of the brain networks emerge and how they develop in the early phase. Here, we employed resting-state functional MRI data and whole-brain functional connectivity analyses in 40 neonates aged around 31-42 postmenstrual weeks to characterize the spatial distribution and development modes of individual variability in the functional network architecture. We observed lower individual variability in primary sensorimotor and visual areas and higher variability in association regions at the third trimester, and these patterns are generally similar to those of adult brains. Different functional systems showed dramatic differences in the development of individual variability, with significant decreases in the sensorimotor network; decreasing trends in the visual, subcortical, and dorsal and ventral attention networks, and limited change in the default mode, frontoparietal and limbic networks. The patterns of individual variability were negatively correlated with the short- to middle-range connection strength/number and this distance constraint was significantly strengthened throughout development. Our findings highlight the development and emergence of individual variability in the functional architecture of the prenatal brain, which may lay network foundations for individual behavioral differences later in life.

BIS index monitoring and perioperative neurocognitive disorders in older adults: a systematic review and meta-analysis.

BACKGROUND AND AIMS: Perioperative neurocognitive disorders (PND) are common in elderly patients after surgery. It has been reported that BIS-guided anesthesia potentially influenced the occurrence of PND. Therefore, we conducted this systematic review and meta-analysis to explore the associations between bispectral index (BIS) monitoring and PND. METHODS: Two researchers independently searched for relevant randomized controlled trials (RCTs) in PubMed, EMBASE, and the Cochrane Library (CENTRAL) using keywords related to the BIS and PND from inception to April 22, 2019. Odds ratios (OR) with 95% CI were calculated using a random effects model. RESULTS: Nine RCTs involving 4023 participants aged 60 years or older were included into this meta-analysis. BIS-guided anesthesia was not associated with lower incidence of POD (random effects; OR: 0.69; 95% CI 0.48, 1.01), delayed neurocognitive recovery (DNR) at 1 day, 7 days (random effects; OR: 0.14; 95% CI 0.02, 1.23; random effects; OR: 0.97; 95% CI 0.57, 1.63), and postoperative neurocognitive disorder (NCD) at 90 days and 1 year after surgery in older adults (random effects; OR:0.72; 95% CI 0.52, 1.00; random effects; OR: 0.26; 95% CI 0.03, 2.47). CONCLUSIONS: No definite evidence demonstrated that BIS-guided anesthesia decreased the incidence of POD, DNR and postoperative NCD in older patients. More homogeneous RCTs assessing the efficacy of BIS monitoring on reducing the occurrence of these perioperative cognitive disorders are needed.

Graph theoretical modeling of baby brain networks.

The human brain undergoes explosive growth during the prenatal period and the first few postnatal years, establishing an early infrastructure for the later development of behaviors and cognitions. Revealing the developmental rules during the early phase is essential for understanding the emergence of brain functions and the origin of developmental disorders. Graph-theoretical network modeling in combination with multiple neuroimaging probes provides an important research framework to explore the early development of the topological wiring and organizational paradigms of the brain. Here, we reviewed studies that employed neuroimaging and graph-theoretical modeling to investigate brain network development from approximately 20 gestational weeks to 2 years of age. Specifically, the structural and functional brain networks have evolved to highly efficient topological architectures in the early stage; where the structural network remains ahead and paves the way for the development of the functional network. The brain network develops in a heterogeneous order, from primary to higher-order systems and from a tendency of network segregation to network integration in the prenatal and postnatal periods. The early brain network topologies show abilities in predicting certain cognitive and behavior performance in later life, and their impairments are likely to continue into childhood and even adulthood. These macroscopic topological changes may be associated with possible microstructural maturations, such as axonal growth and myelinations. Collectively, this review provides a detailed delineation of the early changes in the baby brains in a graph-theoretical modeling framework, which opens up a new avenue for understanding the developmental principles of the connectome.

Comparison of the gastric acid inhibition function among lansoprazole, pantoprazole, and their respective stereoisomers in healthy Chinese subjects
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OBJECTIVE: This study was conducted to evaluate the difference in acid inhibition function among lansoprazole (LPZ), pantoprazole (PPZ), and their respective stereoisomers following single and multiple intravenous doses in healthy Chinese subjects. MATERIALS AND METHODS: The dosage groups were set as follows: 30 mg single and multiple intravenous administrations of LPZ or R-LPZ, 40 mg single and multiple intravenous administrations of PPZ or S-PPZ. Subjects received an intravenous infusion of LPZ, R-LPZ, PPZ, or S-PPZ injection in sterile saline solution (100 mL/h, 60 minutes), respectively. The intragastric pH was sampled every second for 24 hours at baseline and for 24 hours after drug administration. The baseline-adjusted pharmacodynamic (PD) parameters include ΔMean (pH), ΔMedian (pH), ΔTpH≥3 (%), ΔTpH≥4 (%), ΔTpH≥6 (%), and ΔAUECph-tτ1-τ2. The PD parameters were evaluated in different time intervals (0 - 24 hours, 0 - 4 hours and 14 - 24 hours). RESULTS: After a single dose, the ΔTpH≥4 (%) of R-LPZ, LPZ, S-PPZ and PPZ was 56.6 ± 19.6, 53.1 ± 23.3, 35.6 ± 24.9 and 26.8 ± 30.2, respectively. The ΔTpH≥6 (%) was 50.7 ± 26.1, 41.4 ± 26.2, 25.4 ± 24.9 and 22.1 ± 27.6, respectively. The ΔAUECph-τ1-τ was 45,564 ± 16,107, 41,798 ± 16,153, 31,914 ± 17,304 and 20,744 ± 21,500, respectively. Statistically significant differences were found with R-LPZ vs. S-PPZ, R-LPZ vs. PPZ, LPZ vs. S-PPZ and LPZ vs. PPZ. The average TpH≥4 of R-LPZ, LPZ, S-PPZ, and PPZ was (47.2 ± 26.1) minutes, (49.6 ± 19.3) minutes, (56.1 ± 23.7) minutes, and (72.1 ± 27.3) minutes, respectively. Statistically significant differences were found with R-LPZ vs. PPZ (p = 0.009) and LPZ vs. PPZ (p = 0.019). After multiple doses, the ΔTpH≥4 (%) of R-LPZ, LPZ, S-PPZ, and PPZ was 71.7 ± 20.2, 63.5 ± 19.4, 59.5 ± 17.8 and 64.0 ± 22.4, respectively. The ΔTpH≥6 (%) was 64.0 ± 22.2, 52.0 ± 19.2, 49.6 ± 20.4 and 50.9 ± 23.8, respectively. The ΔAUECph-τ1-τ was 326,149 ± 94,839, 288,565 ± 93,279, 296,189 ± 83,412 and 300,960 ± 108,057, respectively. No statistically significant differences were found in baseline-adjusted PD parameters during all time periods after multiple doses. CONCLUSION: After a single dose, the mean gastric pH inhibition value of R-LPZ was the highest, followed by LPZ, then S-PPZ and PPZ. R-LPZ and LPZ provided significantly better pH control compared with PPZ and S-PPZ in healthy subjects. The onset time of R-LPZ was the fastest and R-LPZ can provide better acid inhibition during sleeping time. After multiple doses, the mean values in all PD parameters of R-LPZ were the highest, the values of LPZ, S-PPZ, and PPZ were similar. However, no significant difference was found in acid inhibition among these four drugs after multiple doses.

ASDB: a resource for probing protein functions with small molecules.

UNLABELLED: : Identifying chemical probes or seeking scaffolds for a specific biological target is important for protein function studies. Therefore, we create the Annotated Scaffold Database (ASDB), a computer-readable and systematic target-annotated scaffold database, to serve such needs. The scaffolds in ASDB were derived from public databases including ChEMBL, DrugBank and TCMSP, with a scaffold-based classification approach. Each scaffold was assigned with an InChIKey as its unique identifier, energy-minimized 3D conformations, and other calculated properties. A scaffold is also associated with drugs, natural products, drug targets and medical indications. The database can be retrieved through text or structure query tools. ASDB collects 333 601 scaffolds, which are associated with 4368 targets. The scaffolds consist of 3032 scaffolds derived from drugs and 5163 scaffolds derived from natural products. For given scaffolds, scaffold-target networks can be generated from the database to demonstrate the relations of scaffolds and targets. AVAILABILITY AND IMPLEMENTATION: ASDB is freely available at http://www.rcdd.org.cn/asdb/with the major web browsers. CONTACT: junxu@biochemomes.com or xujun9@mail.sysu.edu.cn SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

Structure and Property of Nano-TiO2 Doped with Ag+ Membrane Photocatalyst.

Highly transparent silver incorporated titania (Ag/TiO2) composite nanomembranes were fabricated by a simple, reproducible dip-coating process on ceramic substrates. The obtained membrane samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectrometer (EDX), X-ray photoelectron spectroscopy (XPS). The photocatalytic activity of the Ag/TiO2 nanomembranes was assessed by the degradation of methylene blue under visible light irradiation. Compared with pure TiO2 nanomembranes, no significant shift in the TiO2 crystal structure was detected after doping with silver ions. The results from the SEM and EDX analyses showed that homogeneous spherical silver nanoparticles were produced and scattered on the surface of the TiO2 nanomembrane that was coated on the surface of the ceramic substrates. The doping with silver ions could effectively improve the photocatalytic activity of TiO2 under visible light irradiation. The Ag/TiO2 composite nanomembrane also exhibited improved hydrophilicity compared to that of a pure TiO2 nanomembrane.

Group III (In/Ga)-V (P/As)-VI (S/Se) Monolayers: A New Class of Auxetic Semiconductors with Highly Anisotropic Electronic/Optical/Mechanical/Thermal Properties.

We present a theoretical design of a class of 2D semiconducting materials, namely, group III (In/Ga)-V (P/As)-VI (S/Se) monolayers, whose global-minimum structures are predicted based on the particle swarm optimization method. Electronic structure calculations suggest that all group III-V-VI monolayers exhibit quasi-direct semiconducting characteristics with desirable band gaps ranging from 1.76 to 2.86 eV (HSE06 functional). Moreover, most group III-V-VI monolayers possess highly anisotropic carrier mobilities with large anisotropic ratios (3.4-6 for electrons, 2.2-25 for holes). G0W0+BSE calculations suggest that these monolayers show high optical anisotropy and relatively large exciton binding energies (0.33-0.75 eV), comparable to that (0.5 eV) of MoS2 monolayer. In particular, the GaPS monolayer manifests strikingly anisotropic I-V curves with a large ON/OFF ratio of ∼105 (106 for the GaPS bilayer) and anisotropic lattice thermal conductivity. Furthermore, the GaPS monolayer is predicted to exhibit both in-plane and out-of-plane negative Poisson ratios (NPRs) and prominent anisotropic Young moduli.

Sivelestat improves acute lung injury by inhibiting PI3K/AKT/mTOR signaling pathway.

OBJECTIVE: To investigate the therapeutic effect and mechanism of sivelestat sodium on acute lung injury (AIL). METHODS: A rat model for ALI/acute respiratory distress syndrome (ALI/ARDS) was established. Pathological examination of lung tissue was conducted to assess lung injury. Blood gas in the arteries was measured using a blood analyzer. Changes in PaO2, PaO2/FiO2, and lung wet/dry (W/D) weight ratio were carefully compared. ELISA assay was conducted to estimate cell adhesion and inflammation response. Finally, real-time reverse transcription polymerase chain reaction and western blotting assay was used to determine the activation of PI3K/AKT/mTOR pathway. RESULTS: ARDS in vivo model was successfully constructed by LPS injection. Compared with the sham group, PaO2 and PaO2/FiO2 were significantly lower in the vehicle group, while the lung W/D ratio, the lung injury score, NE, VCAM-1, IL-8 andTNF-αwere significantly increased. After treatment with different doses of sivelestat sodium, we found PaO2, PaO2/FiO2 were prominently increased, while the lung W/D ratio, the lung injury score, NE, VCAM-1, IL-8, TNF-α levels were decreased in the dose-dependent manner. Meanwhile, compared with the vehicle group, the expression levels of Bax, PI3K, Akt and mTOR were significantly lower, and the expression of Bcl-2 was significantly higher after injection with sivelestat sodium. CONCLUSION: Sivelestat sodium has an interventional effect on ALI in sepsis by inhibiting the PI3K/AKT/mTOR signalling pathway.

Development of sensorimotor-visual connectome gradient at birth predicts neurocognitive outcomes at 2 years of age.

Functional connectome gradients represent fundamental organizing principles of the brain. Here, we report the development of the connectome gradients in preterm and term babies aged 31-42 postmenstrual weeks using task-free functional MRI and its association with postnatal cognitive growth. We show that the principal sensorimotor-to-visual gradient is present during the late preterm period and continuously evolves toward a term-like pattern. The global measurements of this gradient, characterized by explanation ratio, gradient range, and gradient variation, increased with age (p < 0.05, corrected). Focal gradient development mainly occurs in the sensorimotor, lateral, and medial parietal regions, and visual regions (p < 0.05, corrected). The connectome gradient at birth predicts cognitive and language outcomes at 2-year follow-up (p < 0.005). These results are replicated using an independent dataset from the Developing Human Connectome Project. Our findings highlight early emergent rules of the brain connectome gradient and their implications for later cognitive growth.

Development of segregation and integration of functional connectomes during the first 1,000 days.

The first 1,000 days of human life lay the foundation for brain development and later cognitive growth. However, the developmental rules of the functional connectome during this critical period remain unclear. Using high-resolution, longitudinal, task-free functional magnetic resonance imaging data from 930 scans of 665 infants aged 28 postmenstrual weeks to 3 years, we report the early maturational process of connectome segregation and integration. We show the dominant development of local connections alongside a few global connections, the shift of brain hubs from primary regions to high-order association cortices, the developmental divergence of network segregation and integration along the anterior-posterior axis, the prediction of neurocognitive outcomes, and their associations with gene expression signatures of microstructural development and neuronal metabolic pathways. These findings advance our understanding of the principles of connectome remodeling during early life and its neurobiological underpinnings and have implications for studying typical and atypical development.

Study of the structural and the spectral characteristics of [C3N3(NH2)3]n (n = 1-4) clusters.

Previous research has shown that interactions between melamine molecules within a cluster can give rise to the molecular self-assembly and that the spectral characteristic of melamine can be used to inspect melamine in a carrier. Although the structural and spectral characteristics of an isolated single melamine molecule and the molecular arrays on metal or semiconductor surfaces have been studied extensively, little is known about that of isolated multimolecular melamine clusters. In this work, density functional theory (DFT) calculations at the ω-B97XD/6-311++G(d,p) level were performed to study the structural and spectral characteristics of isolated melamine clusters [C3N3(NH2)3]n (n = 1-4) in the ground state. The calculation shows that a ground-state single melamine molecule takes a quasi-planar structure. The C and N atoms of the molecule are in one plane, which we call the molecular plane, while the H atoms deviate slightly from the molecular plane. When melamine molecules gather to form a cluster, the intermolecular hydrogen bonds (IHBs) N-H···N will arise, with the lengths of H···N in the range from 1.960 to 1.970 Å; the length of N-H will be elongated to 1.022 Å from its original of 1.004 Å, the N-H···N bond angles will be about 176°, and the average single-bond binding energy will be approximately -0.285 eV. In a multimolecular cluster, each melamine molecule still takes the quasi-planar structure. Each molecular plane in the cluster retains a planar structure, and some H atoms diverge more from their molecular planes. The molecular planes in a cluster are not coplanar, and the dihedral angle between the molecular planes of two neighboring melamine molecules ranges from 38 to 40°. In addition, the theoretical study of the infrared (IR) spectrum and nuclear magnetic resonance (NMR) spectrum of [C3N3(NH2)3]n (n = 1-4) was conducted. The results confirm the existence of IHBs in a multimolecular melamine cluster and reveal the symmetry of the electron cloud distribution in the melamine clusters. Experimental study of the IR for solid-state melamine and (13)C NMR spectra for both solid- and liquid-state melamine samples were also carried out, in which the corresponding spectral characteristics of [C3N3(NH2)3]n (n = 2-4) clusters deduced from theoretical study were observed. Findings of this study may serve as theoretical references for future identification and utilization of melamine clusters.

TiO2 nanotubes as animal drug delivery system and in vitro controlled release.

The enrofloxacin hydrochloride (Enro), an anti-inflammatory drug for the animals, was loaded on the TNTs through physical absorption due to the high specific surface area and excellent surface activity of the TiO2 nanotubes. The samples were characterized by XRD, BET, TEM, TG and FTIR. The in vitro controlled release behavior at different temperatures was studied in detail. The results showed that the obtained TNTs were uniform and mainly amorphous crystal phase with a diameter of 10-15 nm and a length of 350-400 nm. By investigating the effect of the hydrothermal reaction process of the obtained TiO2 nanotubes and the drug loading frequency on the loading content of Enro drugs, the results indicated that the increasing loading frequency of the drug was available for the drug loading and the maximum loading content of drug reached to 33.28%. Enro-TNTs performed a better release profile at low temperature than at high temperature in PBS solution. The Higuchi square root models are suitable to explain the in vitro drug release behavior of Enro from Enro-TNTs.

Quaternary 2D monolayer Cu2Cl2Se2Hg2: anisotropic carrier mobility and tunable bandgap for transistor and photocatalytic applications.

Despite the advantages of quaternary two-dimensional (2D) materials, fewer studies have been done on them than binary 2D materials. Calculations of quaternary 2D monolayer Cu2Cl2Se2Hg2based on density functional theory and Green's function surface analysis provide insights into its structural, dynamic, and thermal stability. This material has a direct band gap of 0.91/2.0 eV (Perdew-Burke-Ernzerhof/Heyd-Scuseria-Ernzerhof) and demonstrates anisotropic carrier mobility. The electron mobility in theadirection is 1.2 × 103cm2V-1s-1, which is significantly higher than the hole mobility of 0.48 × 103cm2V-1s-1. In thebdirection, the electron mobility is 1.01 × 103cm2V-1s-1and is 8.9 times larger than the hole mobility of 0.11 × 103cm2V-1s-1. The light absorption coefficients of Cu2Cl2Se2Hg2are 1.0 × 105cm-1and 2.5 × 105cm-1in the visible and ultraviolet ranges, respectively. Uniaxial strain leads to an anisotropic alteration in the band gap and band edge position. By manipulating the strain direction and level in Cu2Cl2Se2Hg2, it is possible to increase the current ON/OFF ratio for field-effect transistors (FETs) and to facilitate photocatalytic water splitting through a redox reaction. The research reveals that Cu2Cl2Se2Hg2, a 2D monolayer in the quaternary form, has promising capabilities as an alternative for creating crystal-oriented FETs and photocatalytic water splitting systems.

Type-II 2D AgBr/SiH van der Waals heterostructures with tunable band edge positions and enhanced optical absorption coefficients for photocatalytic water splitting.

Utilizing two-dimensional (2D) heterostructures in photocatalysis can enhance optical ab-sorption and charge separation, thereby increasing solar energy conversion efficiency and tackling environmental issues. Density functional theory (DFT) was employed in this study to investigate the structural and optoelectronic properties of the AgBr/SiH van der Waals (vdW) heterostructures. All three configurations (A1, A2, and A3) were stable, with direct bandgaps of 1.83 eV, 0.99 eV, and 1.36 eV, respectively. The type-II band alignment in these structures enables electrons to be transferred from the SiH layer to the AgBr layer, and holes to move in the opposite direction. In the ultraviolet region, the optical absorption coefficients of the A1, A2, and A3 configurations are approximately 4.0 × 105 cm-1, significantly higher than that of an isolated AgBr monolayer (2.4 × 104 cm-1). In the visible light region, the A1 configuration has an absorption coefficient of 4 × 104 cm-1, higher than that of an isolated AgBr (2.2 × 104 cm-1). The band edges of the A1 configuration satisfy the redox potential for photocatalytic water splitting at pH 0-7. When the biaxial tensile strain is 5% for the A2 configuration and 2% for the A3 configuration, it can allow photocatalytic water splitting from half-reactions without strain to photocatalytic overall water splitting at pH 0-7. With a 5% biaxial tensile strain in the visible light region, the A1 and A3 configurations experience a rise in the maximum absorption coefficient of 5.7 × 104 cm-1 and 4.6 × 104 cm-1, respectively. The findings indicate that the AgBr/SiH vdW heterostructure configurations could be utilized in photocatalytic water-splitting processes with great potential.

The regulatory role of MdNAC14-Like in anthocyanin synthesis and proanthocyanidin accumulation in red-fleshed apples.

Flavonoids, such as anthocyanins and proanthocyanidins (PAs), play essential roles in plant growth, development, and stress response. Red-fleshed apples represent a valuable germplasm resource with high flavonoid content. Understanding and enriching the regulatory network controlling flavonoid synthesis in red-fleshed apples holds significant importance for cultivating high-quality fruits. In this study, we successfully isolated an NAC transcription factor, MdNAC14-Like, which exhibited a significant negative correlation with the content of anthocyanin. Transient injection of apple fruit and stable expression of callus confirmed that MdNAC14-Like acts as an inhibitor of anthocyanin synthesis. Through yeast monohybrid, electrophoretic mobility shift, and luciferase reporter assays, we demonstrated the ability of MdNAC14-Like to bind to the promoters of MdMYB9, MdMYB10, and MdUFGT, thus inhibiting their transcriptional activity and subsequently suppressing anthocyanin synthesis. Furthermore, our investigation revealed that MdNAC14-Like interacts with MdMYB12, enhancing the transcriptional activation of MdMYB12 on the downstream structural gene MdLAR, thereby promoting PA synthesis. This comprehensive functional characterization of MdNAC14-Like provides valuable insights into the intricate regulatory network governing anthocyanin and PA synthesis in apple.