RNA Polymerase II Regulates Topoisomerase 1 Activity to Favor Efficient Transcription.

We report a mechanism through which the transcription machinery directly controls topoisomerase 1 (TOP1) activity to adjust DNA topology throughout the transcription cycle. By comparing TOP1 occupancy using chromatin immunoprecipitation sequencing (ChIP-seq) versus TOP1 activity using topoisomerase 1 sequencing (TOP1-seq), a method reported here to map catalytically engaged TOP1, TOP1 bound at promoters was discovered to become fully active only after pause-release. This transition coupled the phosphorylation of the carboxyl-terminal-domain (CTD) of RNA polymerase II (RNAPII) with stimulation of TOP1 above its basal rate, enhancing its processivity. TOP1 stimulation is strongly dependent on the kinase activity of BRD4, a protein that phosphorylates Ser2-CTD and regulates RNAPII pause-release. Thus the coordinated action of BRD4 and TOP1 overcame the torsional stress opposing transcription as RNAPII commenced elongation but preserved negative supercoiling that assists promoter melting at start sites. This nexus between transcription and DNA topology promises to elicit new strategies to intercept pathological gene expression.

A novel RIPK1 inhibitor reduces GVHD in mice via a nonimmunosuppressive mechanism that restores intestinal homeostasis.

Intestinal epithelial cells (IECs) are implicated in the propagation of T-cell-mediated inflammatory diseases, including graft-versus-host disease (GVHD), but the underlying mechanism remains poorly defined. Here, we report that IECs require receptor-interacting protein kinase-3 (RIPK3) to drive both gastrointestinal (GI) tract and systemic GVHD after allogeneic hematopoietic stem cell transplantation. Selectively inhibiting RIPK3 in IECs markedly reduces GVHD in murine intestine and liver. IEC RIPK3 cooperates with RIPK1 to trigger mixed lineage kinase domain-like protein-independent production of T-cell-recruiting chemokines and major histocompatibility complex (MHC) class II molecules, which amplify and sustain alloreactive T-cell responses. Alloreactive T-cell-produced interferon gamma enhances this RIPK1/RIPK3 action in IECs through a JAK/STAT1-dependent mechanism, creating a feed-forward inflammatory cascade. RIPK1/RIPK3 forms a complex with JAK1 to promote STAT1 activation in IECs. The RIPK1/RIPK3-mediated inflammatory cascade of alloreactive T-cell responses results in intestinal tissue damage, converting the local inflammation into a systemic syndrome. Human patients with severe GVHD showed highly activated RIPK1 in the colon epithelium. Finally, we discover a selective and potent RIPK1 inhibitor (Zharp1-211) that significantly reduces JAK/STAT1-mediated expression of chemokines and MHC class II molecules in IECs, restores intestinal homeostasis, and arrests GVHD without compromising the graft-versus-leukemia (GVL) effect. Thus, targeting RIPK1/RIPK3 in IECs represents an effective nonimmunosuppressive strategy for GVHD treatment and potentially for other diseases involving GI tract inflammation.

Spacecraft Homography Pose Estimation with Single-Stage Deep Convolutional Neural Network.

Spacecraft pose estimation using computer vision has garnered increasing attention in research areas such as automation system theory, control theory, sensors and instruments, robot technology, and automation software. Confronted with the extreme environment of space, existing spacecraft pose estimation methods are predominantly multi-stage networks with complex operations. In this study, we propose an approach for spacecraft homography pose estimation with a single-stage deep convolutional neural network for the first time. We formulated a homomorphic geometric constraint equation for spacecraft with planar features. Additionally, we employed a single-stage 2D keypoint regression network to obtain homography 2D keypoint coordinates for spacecraft. After decomposition to obtain the rough spacecraft pose based on the homography matrix constructed according to the geometric constraint equation, a loss function based on pixel errors was employed to refine the spacecraft pose. We conducted extensive experiments using widely used spacecraft pose estimation datasets and compared our method with state-of-the-art techniques in the field to demonstrate its effectiveness.

Interphase Regulation by Multifunctional Additive Empowering High Energy Lithium-Ion Batteries with Enhanced Cycle Life and Thermal Safety.

High energy density lithium-ion batteries (LIBs) adopting high-nickel layered oxide cathodes and silicon-based composite anodes always suffer from unsatisfied cycle life and poor safety performance, especially at elevated temperatures. Electrode /electrolyte interphase regulation by functional additives is one of the most economic and efficacious strategies to overcome this shortcoming. Herein, cyano-groups (-CN) are introduced into lithium fluorinated phosphate to synthesize a novel multifunctional additive of lithium tetrafluoro (1,2-dihydroxyethane-1,1,2,2-tetracarbonitrile) phosphate (LiTFTCP), which endows high nickel LiNi0.8 Co0.1 Mn0.1 O2 /SiOx -graphite composite full cell with an ultrahigh cycle life and superior safety characteristics, by adding only 0.5 wt % LiTFTCP into a LiPF6 -carbonate baseline electrolyte. It is revealed that LiTFTCP additive effectively suppresses the HF generation and facilitates the formation of a robust and heat-resistant cyano-enriched CEI layer as well as a stable LiF-enriched SEI layer. The favorable SEI/CEI layers greatly lessen the electrode degradation, electrolyte consumption, thermal-induced gassing and total heat-releasing. This work illuminates the importance of additive molecular engineering and interphase regulation in simultaneously promoting the cycling and thermal safety of LIBs with high-nickel NCMxyz cathode and silicon-based composite anode.

Improving the predictions of leaf photosynthesis during and after short-term heat stress with current rice models.

In response to increasing global warming, extreme heat stress significantly alters photosynthetic production. While numerous studies have investigated the temperature effects on photosynthesis, factors like vapour pressure deficit (VPD), leaf nitrogen, and feedback of sink limitation during and after extreme heat stress remain underexplored. This study assessed photosynthesis calculations in seven rice growth models using observed maximum photosynthetic rate (Pmax ) during and after short-term extreme heat stress in multi-year environment-controlled experiments. Biochemical models (FvCB-type) outperformed light response curve-based models (LRC-type) when incorporating observed leaf nitrogen, photosynthetically active radiation, temperatures, and intercellular CO2 concentration (Ci ) as inputs. Prediction uncertainty during heat stress treatment primarily resulted from variation in temperatures and Ci . Improving FVPD (the slope for the linear effect of VPD on Ci /Ca ) to be temperature-dependent, rather than constant as in original models, significantly improved Ci prediction accuracy under heat stress. Leaf nitrogen response functions led to model variation in leaf photosynthesis predictions after heat stress, which was mitigated by calibrated nitrogen response functions based on active photosynthetic nitrogen. Additionally, accounting for observed differences in carbohydrate accumulation between panicles and stems during grain filling improved the feedback of sink limitation, reducing Ci overestimation under heat stress treatments.

Exploring the limits of metasurface polarization multiplexing capability based on deep learning.

Metasurfaces provide a new approach for planar optics and thus have realized multifunctional meta-devices with different multiplexing strategies, among which polarization multiplexing has received much attention due to its convenience. At present, a variety of design methods of polarization multiplexed metasurfaces have been developed based on different meta-atoms. However, as the number of polarization states increases, the response space of meta-atoms becomes more and more complex, and it is difficult for these methods to explore the limit of polarization multiplexing. Deep learning is one of the important routes to solve this problem because it can realize the effective exploration of huge data space. In this work, a design scheme for polarization multiplexed metasurfaces based on deep learning is proposed. The scheme uses a conditional variational autoencoder as an inverse network to generate structural designs and combines a forward network that can predict meta-atoms' responses to improve the accuracy of designs. The cross-shaped structure is used to establish a complicated response space containing different polarization state combinations of incident and outgoing light. The multiplexing effects of the combinations with different numbers of polarization states are tested by utilizing the proposed scheme to design nanoprinting and holographic images. The polarization multiplexing capability limit of four channels (a nanoprinting image and three holographic images) is determined. The proposed scheme lays the foundation for exploring the limits of metasurface polarization multiplexing capability.

Design, synthesis, evaluation and optimization of potent IRAK4 inhibitors alleviating production of inflammatory cytokines in LPS-induced SIRS model.

Interleukin-1 receptor associated kinase-4 (IRAK4) has emerged as a therapeutic target for inflammatory and autoimmune diseases. Through reversing the amide of CA-4948 and computer aided structure-activity relationship (SAR) studies, a series of IRAK4 inhibitors with oxazolo[4,5-b]pyridine scaffold were identified. Compound 32 showed improved potency (IC50 = 43 nM) compared to CA-4948 (IC50 = 115 nM), but suffered from hERG inhibition (IC50 = 5.7 µM). Further optimization led to compound 42 with reduced inhibition of hERG (IC50 > 30 µM) and 13-fold higher activity (IC50 = 8.9 nM) than CA-4948. Importantly, compound 42 had favorable in vitro ADME and in vivo pharmacokinetic properties. Furthermore, compound 42 significantly reduced LPS-induced production of serum TNF-α and IL-6 cytokines in the mouse model. The overall profiles of compound 42 support it as a lead for the development of IRAK4 inhibitors for the treatment of inflammatory and autoimmune disorders.

Long-term safety of infants from mothers with chronic hepatitis B treated with tenofovir disoproxil in China.

OBJECTIVE: The physical and neuromental development of infants remains uncertain after fetal exposure to tenofovir disoproxil fumarate (TDF) for the prevention of mother-to-child transmission of HBV. We aimed to investigate the safety of TDF therapy during the third trimester of pregnancy. DESIGN: Infants from a previous randomised controlled trial were recruited for our long-term follow-up (LTFU) study. Mothers with chronic hepatitis B were randomised to receive TDF therapy or no treatment during the third trimester. Infants' physical growth or malformation, bone mineral density (BMD) and neurodevelopment, as assessed using Bayley-III assessment, were examined at 192 weeks of age. RESULTS: Of 180 eligible infants, 176/180 (98%) were enrolled and 145/176 (82%) completed the LTFU (control group: 75; TDF-treated group: 70). In the TDF-treated group, the mean duration of fetal exposure to TDF was 8.57±0.53 weeks. Congenital malformation rates were similar between the two groups at week 192. The mean body weight of boys in the control and TDF-treated groups was significantly higher (19.84±3.46 kg vs. 18.47±2.34 kg; p=0.03) and within the normal range (18.48±2.35 kg vs. 17.80±2.50 kg; p=0.07), respectively, when compared with the national standard. Other prespecified outcomes (head circumference, height, BMD, and cognitive, motor, social-emotional, and adaptive behaviour measurements) were all comparable between the groups. CONCLUSION: Infants with fetal exposure to TDF had normal physical growth, BMD and neurodevelopment at week 192. Our findings provide evidence on the long-term safety of infants after fetal exposure to maternal TDF therapy for preventing hepatitis B transmission. TRIAL REGISTRATION NUMBER: NCT01488526.

Design, synthesis, and structure-activity relationship of novel RIPK2 inhibitors.

The NOD1/2 (nucleotide-binding oligomerization domain-containing protein 1/2) signaling pathways are involved in innate immune control and host defense. NOD dysfunction can result in a variety of autoimmune disorders. NOD-induced generation of inflammatory cytokines is mediated by receptor-interacting protein kinase 2 (RIPK2), which has been considered as a promising therapeutic target. Herein, we disclose the design, synthesis, and SAR study of a series of RIPK2 inhibitors. The lead compound 17 displayed a high affinity for RIPK2 (Kd = 5.9 nM) and was capable of inhibiting RIPK2 kinase function in an ADP-Glo assay. In vitro DMPK studies showed that compound 17 had good metabolic stability and no CYP inhibition. Compound 17 effectively suppressed inflammatory cytokine production in both cells and animal model.

Discovery, optimization and evaluation of isothiazolo[5,4-b]pyridine derivatives as RIPK1 inhibitors with potent in vivo anti-SIRS activity.

Receptor-interacting protein kinase-1 (RIPK1) is involved in the necroptosis pathway, which regulates inflammatory signaling and cell death in a variety of diseases, including inflammatory and neurodegenerative disorders. We identified a novel hit compound 36 by a cell-based screening assay (anti-necroptosis EC50 = 58 nM). Starting from compound 36, we designed a series of scaffolds to improve anti-necroptosis activity, physicochemical properties and metabolic stability. The isothiazolo[5,4-b]pyridine backbone proved to be a promising scaffold which provided a number of potent necroptosis inhibitors. Compound 56, for example, effectively blocked necroptosis in both human and mouse cells (EC50 = 1-5 nM). A binding assay showed that compound 56 potently binds to RIPK1 (Kd = 13 nM), but not RIPK3 (Kd > 10,000 nM). Kinase functional assay (ADP-Glo) confirmed that compound 56 inhibits RIPK1 phosphorylation with an IC50 at 5.8 nM. Importantly, compound 56 displayed excellent cross-species liver microsomal metabolic stability (t1/2 > 90 min). Furthermore, compound 56 exhibited favorable in vitro safety profiles in hERG and CYP assays. Finally, pre-treatment with 56 significantly reduced hypothermia and lethal shock in the systemic inflammatory response syndrome mice model. Taken together, compound 56 represented a promising prototype for the development of therapeutic agent to treat inflammation-related diseases.

Structural and functional studies of TBC1D23 C-terminal domain provide a link between endosomal trafficking and PCH.

Pontocerebellar hypoplasia (PCH) is a group of neurological disorders that affect the development of the brain, in particular, the pons and cerebellum. Homozygous mutations of TBC1D23 have been found recently to lead to PCH; however, the underlying molecular mechanisms remain unclear. Here, we show that the crystal structure of the TBC1D23 C-terminal domain adopts a Pleckstrin homology domain fold and selectively binds to phosphoinositides, in particular, PtdIns(4)P, through one surface while binding FAM21 via the opposite surface. Mutation of key residues of TBC1D23 or FAM21 selectively disrupts the endosomal vesicular trafficking toward the Trans-Golgi Network. Finally, using the zebrafish model, we show that PCH patient-derived mutants, impacting either phosphoinositide binding or FAM21 binding, lead to abnormal neuronal growth and brain development. Taken together, our data provide a molecular basis for the interaction between TBC1D23 and FAM21, and suggest a plausible role for PtdIns(4)P in the TBC1D23-mediating endosome-to-TGN trafficking pathway. Defects in this trafficking pathway are, at least partially, responsible for the pathogenesis of certain types of PCH.

Early glycolytic reprogramming controls microglial inflammatory activation.

BACKGROUND: Microglial activation-mediated neuroinflammation plays an important role in the progression of neurodegenerative diseases. Inflammatory activation of microglial cells is often accompanied by a metabolic switch from oxidative phosphorylation to aerobic glycolysis. However, the roles and molecular mechanisms of glycolysis in microglial activation and neuroinflammation are not yet fully understood. METHODS: The anti-inflammatory effects and its underlying mechanisms of glycolytic inhibition in vitro were examined in lipopolysaccharide (LPS) activated BV-2 microglial cells or primary microglial cells by enzyme-linked immunosorbent assay (ELISA), quantitative reverse transcriptase-polymerase chain reaction (RT-PCR), Western blot, immunoprecipitation, flow cytometry, and nuclear factor kappa B (NF-κB) luciferase reporter assays. The anti-inflammatory and neuroprotective effects of glycolytic inhibitor, 2-deoxoy-D-glucose (2-DG) in vivo were measured in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-or LPS-induced Parkinson's disease (PD) models by immunofluorescence staining, behavior tests, and Western blot analysis. RESULTS: We found that LPS rapidly increased glycolysis in microglial cells, and glycolysis inhibitors (2-DG and 3-bromopyruvic acid (3-BPA)), siRNA glucose transporter type 1 (Glut-1), and siRNA hexokinase (HK) 2 abolished LPS-induced microglial cell activation. Mechanistic studies demonstrated that glycolysis inhibitors significantly inhibited LPS-induced phosphorylation of mechanistic target of rapamycin (mTOR), an inhibitor of nuclear factor-kappa B kinase subunit beta (IKKß), and NF-kappa-B inhibitor alpha (IκB-α), degradation of IκBα, nuclear translocation of p65 subunit of NF-κB, and NF-κB transcriptional activity. In addition, 2-DG significantly inhibited LPS-induced acetylation of p65/RelA on lysine 310, which is mediated by NAD-dependent protein deacetylase sirtuin-1 (SIRT1) and is critical for NF-κB activation. A coculture study revealed that 2-DG reduced the cytotoxicity of activated microglia toward MES23.5 dopaminergic neuron cells with no direct protective effect. In an LPS-induced PD model, 2-DG significantly ameliorated neuroinflammation and subsequent tyrosine hydroxylase (TH)-positive cell loss. Furthermore, 2-DG also reduced dopaminergic cell death and microglial activation in the MPTP-induced PD model. CONCLUSIONS: Collectively, our results suggest that glycolysis is actively involved in microglial activation. Inhibition of glycolysis can ameliorate microglial activation-related neuroinflammatory diseases.

An Accurate Linear Method for 3D Line Reconstruction for Binocular or Multiple View Stereo Vision.

For the problem of 3D line reconstruction in binocular or multiple view stereo vision, when there are no corresponding points on the line, the method called Direction-then-Point (DtP) can be used, and if there are two pairs of corresponding points on the line, the method called Two Points 3D coordinates (TPS) can be used. However, when there is only one pair of corresponding points on the line, can we get the better accuracy than DtP for 3D line reconstruction? In this paper, a linear and more accurate method called Point-then-Direction (PtD) is proposed. First, we used the intersection method to obtain the 3D point's coordinate from its corresponding image points. Then, we used this point as a position on the line to calculate the direction of the line by minimizing the image angle residual. PtD is also suitable for multiple camera systems. The simulation results demonstrate that PtD increases the accuracy of both the direction and the position of the 3D line compared to DtP. At the same time, PtD achieves a better result in direction of the 3D line than TPS, but has a lower accuracy in the position of 3D lines than TPS.

Novel renal medullary carcinoma cell lines, UOK353 and UOK360, provide preclinical tools to identify new therapeutic treatments.

Renal medullary carcinoma (RMC) is a rare, aggressive disease that predominantly afflicts individuals of African or Mediterranean descent with sickle cell trait. RMC comprises 1% of all renal cell carcinoma diagnoses with a median overall survival of 13 months. Patients are typically young (median age-22) and male (male:female ratio of 2:1) and tumors are characterized by complete loss of expression of the SMARCB1 tumor suppressor protein. Due to the low incidence of RMC and the disease's aggressiveness, treatment decisions are often based on case reports. Thus, it is critical to develop preclinical models of RMC to better understand the pathogenesis of this disease and to identify effective forms of therapy. Two novel cell line models, UOK353 and UOK360, were derived from primary RMCs that both demonstrated the characteristic SMARCB1 loss. Both cell lines overexpressed EZH2 and other members of the polycomb repressive complex and EZH2 inhibition in RMC tumor spheroids resulted in decreased viability. High throughput drug screening of both cell lines revealed several additional candidate compounds, including bortezomib that had both in vitro and in vivo antitumor activity. The activity of bortezomib was shown to be partially dependent on increased oxidative stress as addition of the N-acetyl cysteine antioxidant reduced the effect on cell proliferation. Combining bortezomib and cisplatin further decreased cell viability both in vitro and in vivo that single agent bortezomib treatment. The UOK353 and UOK360 cell lines represent novel preclinical models for the development of effective forms of therapy for RMC patients.

Knockdown of milk-fat globule EGF factor-8 suppresses glioma progression in GL261 glioma cells by repressing microglial M2 polarization.

Tumor-associated microglial cells promote glioma growth, invasion, and chemoresistance by releasing inflammatory factors. Milk fat globule EGF factor 8 protein (MFG-E8), a secreted glycoprotein, is closely related to tissue homeostasis and anti-inflammation. In the present study, we investigated the role of MFG-E8 in microglial polarization and glioma progression in vitro and in vivo. We found that glioma cells secrete comparable amounts of MFG-E8 in culture media to astrocytes. Recombinant MFG-E8 triggered microglia to express the M2 polarization markers, such as arginase-1 (ARG-1), macrophage galactose-type C-type lectin-2 (MGL-2), and macrophage mannose receptor (CD206). Forced expression of MFG-E8 in BV-2 microglia cells not only promoted IL-4-induced M2 polarization but also inhibited lipopolysaccharide (LPS)-induced M1 microglial polarization. Mechanistic studies demonstrated that recombinant MFG-E8 markedly induced signal transducer and activator of transcription 3 (STAT3) phosphorylation, and the STAT3 inhibitor stattic significantly blocked MFG-E8-induced ARG-1 expression. Administration of antibody against MFG-E8 and knockdown of its receptor, integrin ß3, significantly attenuated MFG-E8-induced ARG-1 expression. Similarly, knockdown of MFG-E8 also markedly reduced IL-4-induced M2 marker expression and increased LPS-induced M1 marker expression in microglia cells. Moreover, the knockdown of MFG-E8 in GL261 glioma cells inhibited cell proliferation and enhanced chemosensitivity to 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU), which was likely associated with the downregulation of FAK/AKT activation and STAT3/cyclin D1 signaling. The murine GL261 glioma experimental model demonstrated that knockdown of MFG-E8 significantly reduced tumor size and extended survival times. Additionally, attenuated CD11b+ cell infiltration and reduced CD206+ expression in CD11b+ cells were also observed in an MFG-E8 knockdown GL261 murine glioma model. These results suggested that inhibition of MFG-E8 might hamper the immunosuppressive microenvironment in gliomas and therefore ameliorate tumor progression.

Achromatic metasurface doublet with a wide incident angle for light focusing.

Benefiting from the excellent capabilities of arbitrarily controlling the phase, amplitude and polarization of the electromagnetic wave, metasurfaces have attracted much attention and brought forward the revolution of fields ranging from device fabrications to optical applications. Cascaded metasurfaces have been demonstrated to correct the monochromatic aberration and enable a near-diffraction-limited focusing spot over a wide incident angle. However, they can only work under the design wavelength and suffer from the axial chromatic aberration at another wavelength. Here, an achromatic metasurface doublet is proposed to eliminate the axial achromatic aberration and enable high-quality focusing with a wide incident angle at distinct wavelengths. It consists of square nanopillar arrays with spatially varying width to simultaneously realize wavelength-dependent phase controls. The constructed metasurface doublet is further verified numerically and near-diffraction-limited foci are exactly formed at the same plane with an incident angle up to 20° for design wavelengths. We expect that our proposed approach can find optical applications in the fields of holograms, photograms, microscopy and machine vision.

Achromatic super-oscillatory metasurface through optimized multiwavelength functions for sub-diffraction focusing.

Optical super-oscillatory lenses based on planar micro/nano structures have been demonstrated as promising alternatives for shaping wavefronts of light and realizing super-resolution images in a NA-limited optical system. However, as the super-oscillatory foci originated from the delicate interference of the light, the change of the parameters might destroy the hotspots, such as the incident wavelength. Here, a multiwavelength achromatic super-oscillatory metasurface (ASOM) is proposed through simultaneously controlling distinct wavelength-dependent wavefronts. The constructed multiwavelength ASOM is then verified numerically, and the foci are precisely formed at the same axial plane for the design wavelengths with resolution beyond the diffraction limit. We expect that our proposed multiwavelength controllable method will give more freedom for the designs of planar and lightweight components, which would be useful in optical applications, such as data storage, super-resolution imaging, holography, etc.

Design, synthesis, and evaluation of novel CXCR4 antagonists based on an aminoquinoline template.

The chemokine receptor CXCR4 has been explored as a drug target due to its involvement in pathological conditions such as HIV infection and cancer metastasis. Here we report the structure-activity relationship study of novel CXCR4 antagonists based on an aminoquinoline template. This template is devoid of the chiral center in the classical tetrahydroquinoline (THQ) ring moiety and therefore can be easily synthesized. A number of potent CXCR4 antagonists were identified, exemplified by compound 3, which demonstrated excellent binding affinity with CXCR4 receptor (IC50 = 57 nM) and inhibited CXCL12 induced cytosolic calcium increase (IC50 = 0.24 nM). Furthermore, compound 3 potently inhibited CXLC12/CXCR4 mediated cell migration in a transwell invasion assay. The simplified synthetic approach combined with good physicochemical properties (e.g. MW 362, clogP 2.1, PSA 48, pKa 7.0 for compound 3) demonstrate the potential of this aminoquinoline template as a novel scaffold to develop CXCR4 antagonists.

Foxg1 Directly Represses Dbx1 to Confine the POA and Subsequently Regulate Ventral Telencephalic Patterning.

During early development, signaling centers, such as the cortical hem and the preoptic area (POA), are critical for telencephalic patterning. However, the mechanisms underlying the maintenance of signal centers are poorly understood. Here, we report that the transcription factor Foxg1 is required to confine the POA, a resource of Sonic Hedgehog (Shh) that is pivotal for ventral telencephalic development. Cell-specific deletion of Foxg1 achieved by crossing Foxg1fl/fl with Dbx1-cre or Nestin-CreER combined with tamoxifen induction results in a dramatic expansion of the POA accompanied by the significantly increased activity of the Shh signaling pathway. Ventral pattern formation was severely impaired. Moreover, we demonstrated that Foxg1 directly represses Dbx1 to restrict the POA. Furthermore, we found that the ventral pallium was expanded, which might also contribute to the observed patterning defects. These findings will improve our understanding of the maintenance of signal centers and help to elucidate the mechanisms underlying ventral telencephalic patterning.

Enhanced Light-Driven Hydrogen-Production Activity Induced by Accelerated Interfacial Charge Transfer in Donor-Acceptor Conjugated Polymers/TiO2 Hybrid.

Donor-acceptor (D-A) conjugated polymers have proved to be desired candidates to couple with inorganic semiconductors for enhanced photocatalytic activity. Herein, the matched energy levels between polymer BFB and TiO2 make them form BFB-TiO2 composites with moderate photocatalytic H2 evolution rate (HER). To further enhance the interfacial interaction, BFB was modified with a carboxylic acid end group, which reacted with surface OH of TiO2 to form an ester bond. As a result, the functionalized BFBA-TiO2 composites exhibited superior photocatalytic activity. Especially, HER of 4 % BFBA-TiO2 can reach up to 228.2 µmol h-1 under visible light irradiation (λ>420 nm), which is about 2.02 times higher than that of BFB-TiO2 . The enhanced photocatalytic activity originated from the formed ester bond between polymer and TiO2 , and photogenerated electrons injection from lowest unoccupied molecular orbital (LUMO) of the exited polymer to conduction band of TiO2 were accelerated. Therefore, based on an intermolecular interaction mechanism, more suitable D-A conjugated polymers with anchoring groups could be designed to couple with other semiconductors for enhancing photocatalytic activity.