139 results on '"Liu PN"'
Search Results
2. Engineering an Organic Nanoplatform for Augmented Pyroeletroimmunotherapy.
- Author
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Li X, Gao ML, Wang SS, Li YL, Liu TN, Xiang H, and Liu PN
- Subjects
- Animals, Mice, Cell Line, Tumor, Photothermal Therapy, Humans, Reactive Oxygen Species metabolism, Lung Neoplasms therapy, Infrared Rays, Immunotherapy, Nanoparticles chemistry
- Abstract
Photothermal immunotherapy has shown great promise in the treatment of tumor metastasis. However, the thermal resistance of tumor cells substantially compromises the treatment effect of photothermal immunotherapy. Herein, a high-performance organic pyroelectric nanoplatform,
t Bu-TPAD-BF2 nanoparticles (NPs), is rationally engineered for the effective pyroelectroimmunotherapy of tumor metastasis. Biocompatiblet Bu-TPAD-BF2 NPs with excellent pyroelectric and photothermal conversion properties are constructed by assembling organic, low-bandgap pyroelectric molecules with amphiphilic polymers. After internalization by tumor cells, treatment witht Bu-TPAD-BF2 NPs causes an apparent temperature elevation upon near-infrared (NIR) laser irradiation, inducing potent immunogenic cell death (ICD). Additionally, the temperature variations under alternating NIR laser irradiation facilitate reactive oxygen species production for pyroelectric therapy, thus promoting ICD activation and lowering thermal resistance. Importantly, in vivo assessments illustrate thatt Bu-TPAD-BF2 NPs in combination with NIR laser exposure notably inhibit primary and distant tumor proliferation and prominently retarded lung metastasis. RNA profiling reveals that treatment witht Bu-TPAD-BF2 NPs markedly suppresses metastasis under NIR laser illumination by downregulating metastasis-related genes and upregulating immune response-associated pathways. Therefore, this study provides a strategy for designing high-performance pyroelectric nanoplatforms to effectively cure tumor metastasis, thereby overcoming the inherent shortcomings of photothermal immunotherapy., (© 2024 Wiley‐VCH GmbH.)- Published
- 2024
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3. On-Surface Self-Assembly Kinetic Study of Cu-Hexaazatriphenylene 2D Conjugated Metal-Organic Frameworks on Coinage Metals and MoS 2 Substrates.
- Author
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Lyu C, Gao Y, Zhou K, Hua M, Shi Z, Liu PN, Huang L, and Lin N
- Abstract
Supramolecular coordination self-assembly on solid surfaces provides an effective route to form two-dimensional (2D) metal-organic frameworks (MOFs). In such processes, surface-adsorbate interaction plays a key role in determining the MOFs' structural and chemical properties. Here, we conduct a systematic study of Cu-HAT (HAT = 1,4,5,8,9,12-hexaazatriphenylene) 2D conjugated MOFs ( c -MOFs) self-assembled on Cu(111), Au(111), Ag(111), and MoS
2 substrates. Using scanning tunneling microscopy and density functional theory calculations, we found that the as-formed Cu3 HAT2 c -MOFs on the four substrates exhibit distinctive structural features including lattice constant and molecular conformation. The structural variations can be attributed to the differentiated substrate effects on the 2D c -MOFs, including adsorption energy, lattice commensurability, and surface reactivity. Specifically, the framework grown on MoS2 is nearly identical to its free-standing counterpart. This suggests that the 2D van der Waals (vdW) materials are good candidate substrates for building intrinsic 2D MOFs, which hold promise for next-generation electronic devices.- Published
- 2024
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4. Construction of Two-Dimensional Organometallic Coordination Networks with Both Organic Kagome and Semiregular Metal Lattices on Au(111).
- Author
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Kang LX, Wang BX, Zhang XY, Zhu YC, Li DY, and Liu PN
- Abstract
Two-dimensional metal-organic networks (2D MONs) having heterogeneous coordination nodes (HCNs) could exhibit excellent performance in catalysis and optoelectronics because of the unbalanced electron distribution of the coordinating metals. Therefore, the design and construction of 2D MONs with HCNs are highly desirable but remain challenging. Here, we report the construction of 2D organometallic coordination networks with an organic Kagome lattice and a semiregular metal lattice on Au(111) via the in situ formation of HCNs. Using a bifunctional precursor 1,4-dibromo-2,5-diisocyanobenzene, the coordination of isocyano with Au adatom on a room-temperature Au(111) yielded metal-organic coordination chains with isocyano-Au-isocyano nodes. In contrast, on a high-temperature Au(111), a selective debromination/coordination cascade reaction occurred, affording 2D organometallic coordination networks with phenyl-Au-isocyano nodes. By combining scanning tunneling microscopy and density functional theory calculations, we determined the structures of coordination products and the nature of coordination nodes, demonstrating a thermodynamically favorable pathway for forming the phenyl-Au-isocyano nodes.
- Published
- 2024
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5. Two-Dimensional Nonbenzenoid Heteroacene Crystals Synthesized via In-Situ Embedding of Ladder Bipyrazinylenes on Au(111).
- Author
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Wang Y, Gong WW, Zhao Y, Xing GY, Kang LX, Sha F, Huang ZY, Liu JW, Han YJ, Li P, Li DY, and Liu PN
- Abstract
Precisely introducing topological defects is an important strategy in nanographene crystal engineering because defects can tune π-electronic structures and control molecular assemblies. The synergistic control of the synthesis and assembly of nanographenes by embedding the topological defects to afford two-dimensional (2D) crystals on surfaces is still a great challenge. By in-situ embedding ladder bipyrazinylene (LBPy) into acene, the narrowest nanographene with zigzag edges, we have achieved the precise preparation of 2D nonbenzenoid heteroacene crystals on Au(111). Through intramolecular electrocyclization of o-diisocyanides and Au adatom-directed [2+2] cycloaddition, the nonbenzenoid heteroacene products are produced with high chemoselectivity, and lead to the molecular 2D assembly via LBPy-derived interlocking hydrogen bonds. Using bond-resolved scanning tunneling microscopy, we determined the atomic structures of the nonbenzenoid heteroacene product and diverse organometallic intermediates. The tunneling spectroscopy measurements revealed the electronic structure of the nonbenzenoid heteroacene, which is supported by density functional theory (DFT) calculations. The observed distinct organometallic intermediates during progression annealing combined with DFT calculations demonstrated that LBPy formation proceeds via electrocyclization of o-diisocyanides, trapping of heteroarynes by Au adatoms, and stepwise elimination of Au adatoms., (© 2024 Wiley-VCH GmbH.)
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- 2024
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6. Enantioselective synthesis of spiro- N , O -ketals via iridium and Brønsted acid co-catalyzed asymmetric formal [4+2] cycloaddition.
- Author
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Xie XQ, Li X, and Liu PN
- Abstract
We present an iridium and Brønsted acid co-catalyzed enantioselective formal [4+2] cycloaddition reaction of cyclic enamides with 2-(1-hydroxyallyl)phenols. This method yields a wide range of N -unsubstituted spiro- N , O -ketals, with good efficiency (up to 94%) and excellent enantioselectivities (most >95% ee). The protocol features easy scale-up and facile product derivatization.
- Published
- 2024
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7. [Study on transcriptome characteristics of respiratory syncytial virus bronchiolitis in children by RNA sequencing].
- Author
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Wang LY, Le YS, Li HY, Liu ZW, Weng TT, Chen XF, Liu PN, and Dong L
- Subjects
- Child, Humans, Interleukin-10, Matrix Metalloproteinase 9, Case-Control Studies, Sequence Analysis, RNA, Receptors, Cytokine, Viral Proteins, Respiratory Syncytial Viruses, Computational Biology methods, Transcriptome, Respiratory Syncytial Virus Infections genetics
- Abstract
To explore the biological characteristics related to the pathogenesis and severity of respiratory syncytial virus (RSV) bronchiolitis by RNA sequencing of white blood cells in children with RSV bronchiolitis. This study is a case-control study. A total of 87 children diagnosed with bronchiolitis and RSV antigen positive and/or RSV nucleic acid positive in the pediatric respiratory department of the Second Affiliated Hospital of Wenzhou Medical University from October 2019 to April 2022 were selected as the case group. The case group was divided into three groups based on the condition: mild, moderate, and severe, and there were two groups according to the presence or absence of atopic symptoms: the atopic group and the non - atopic group, forty healthy children in the same period were selected as the control group. The whole blood leukocyte RNA of the children in the case group and the control group was extracted for RNA sequencing, and the data were analyzed to obtain differentially expressed genes (DEGs). Then, the immunobiological pathways and genes related to the pathogenesis, disease condition, and atopy were screened through Gene Ontology (GO) annotation, Kyoto Gene and Genome Encyclopedia (KEGG) annotation, and protein interaction network (PPI) construction methods. Construct the weighted gene co-expression network analysis (WGCNA) module to identify potential biological indicators related to disease severity.Compared with the control group, the case group had a total of 1 782 DEGs, including 1 586 upregulated genes and 196 downregulated genes. The GO pathway enrichment of DEGs is mainly enriched in molecular functions such as peroxidase activity and oxidoreductase activity. In the cytological components, it is mainly enriched in cytoplasmic vesicle lumen and secretory granule lumen. In biological processes, it is mainly enriched in processes such as neutrophil activation involved in immune responses, neutrophil degranulation, and neutrophil activation. KEGG analysis is mainly concentrated in the signal pathway of the viral protein interaction with cytokine and cytokine receptor. A PPI network was constructed to screen four genes at the core position, including CCL2, IL-10, MMP9 and JUN . The DEGs obtained by comparing different disease groups with the control group are mainly enriched in retrograde endocannabinoid signaling and cell apoptosis pathways. WGCNA analysis showed that the brown module related to oxygen saturation was most closely related to the disease, and its gene was mainly enriched in the RNA helicase retinoic acid inducible gene-I (RIG-I) like receptor signal pathway. There are 230 specific DEGs in the atopic group and 444 in the non - atopic group. KEGG enrichment analysis results show that both groups are enriched to NF-κB signaling pathway, the characteristic does not cause significant changes in immune response and transcriptome characteristics in children with RSV bronchiolitis. In conclusion, neutrophil activation, degranulation pathway and signal pathway of interaction between viral protein and cytokine and cytokine receptor are involved in the immune response of RSV bronchiolitis host. CCL2, IL-10, MMP9 and JUN genes may be associated with the pathogenesis. They might be potential biomarkers related to disease severity in RIG-I like receptors, cell apoptosis, and endogenous cannabinoid related signaling pathways.
- Published
- 2024
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8. Internal carotid artery injury during endoscopic transsphenoidal pituitary surgery: risk factors, management.
- Author
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Ma X, Zhang Y, Yang ZJ, Bo W, Wang XC, Zhang C, Liu PN, and Bi ZY
- Subjects
- Humans, Carotid Artery, Internal surgery, Retrospective Studies, Endoscopy adverse effects, Pituitary Neoplasms surgery, Pituitary Neoplasms complications, Carotid Artery Injuries etiology, Carotid Artery Injuries surgery
- Abstract
Background: Transsphenoidal surgeons should try to avoid internal carotid artery (ICA) injury but also be prepared to manage it. We analyzed our experience with ICA injury during endoscopic transsphenoidal pituitary surgery and present associated risk factors and a management protocol., Methods: We retrospectively reviewed and analyzed the medical records of 1596 patients who underwent endoscopic transsphenoidal surgery for pituitary tumor resection in our institution from January 2009 to October 2022., Results: Six patients experienced an ICA injury. All received timely and effective hemostasis with immediate direct tamponade followed by endovascular treatment. No serious postoperative complications occurred., Conclusions: We proposed a treatment plan for ICA injuries encountered during endoscopic transsphenoidal surgery and described our hemostasis process, methods of endovascular treatment, and means of postoperative follow-up in detail., (Copyright © 2023 Elsevier Masson SAS. All rights reserved.)
- Published
- 2024
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9. Quantum Phase Transition in Magnetic Nanographenes on a Lead Superconductor.
- Author
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Liu Y, Li C, Xue FH, Su W, Wang Y, Huang H, Yang H, Chen J, Guan D, Li Y, Zheng H, Liu C, Qin M, Wang X, Wang R, Li DY, Liu PN, Wang S, and Jia J
- Abstract
Quantum spins, also known as spin operators that preserve SU(2) symmetry, lack a specific orientation in space and are hypothesized to display unique interactions with superconductivity. However, spin-orbit coupling and crystal field typically cause a significant magnetic anisotropy in d/f shell spins on surfaces. Here, we fabricate atomically precise S = 1/2 magnetic nanographenes on Pb(111) through engineering sublattice imbalance in the graphene honeycomb lattice. Through tuning the magnetic exchange strength between the unpaired spin and Cooper pairs, a quantum phase transition from the singlet to the doublet state has been observed, consistent with the quantum spin models. From our calculations, the particle-hole asymmetry is induced by the Coulomb scattering potential and gives a transition point about k
B Tk ≈ 1.6Δ. Our work demonstrates that delocalized π electron magnetism hosts highly tunable magnetic bound states, which can be further developed to study the Majorana bound states and other rich quantum phases of low-dimensional quantum spins on superconductors.- Published
- 2023
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10. Ultra-early electroacupuncture rehabilitation for intravenous thrombolysis-induced cerebral infarction.
- Author
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Liu LL, Liu PN, Li XA, and Li YN
- Subjects
- Humans, Cerebral Infarction therapy, Thrombolytic Therapy, Treatment Outcome, Electroacupuncture methods, Stroke therapy, Brain Ischemia
- Abstract
Objective: The purpose of this research was to investigate whether it is possible to perform ultra-early interventional electroacupuncture on individuals who had experienced intravenous thrombolysis prior to receiving therapy for acute cerebral infarction., Patients and Methods: Patients who have undergone intravenous thrombolysis between July 2019 and March 2021 were eligible for participation in this study. The participants were divided into two groups; one group received electroacupuncture therapy 24 hours after their condition became stable, while the other group received treatment 48 hours after their condition became stable. Both groups received the same therapy for their respective forms of rehabilitation. The Fugl-Meyer Motion Assessment Scale (FMA) was used to assess the patients' motor function before and after therapy, as well as two weeks and one month after treatment. The scores of the FMA were recorded before and after treatment., Results: After therapy, the FMI scores were higher in both groups (p<0.05), and the researchers found that the ultra-early electroacupuncture intervention was related to higher FMI ratings 2 weeks and 1 month after treatment (p<0.05). In neither of the two study groups was there any sign of a major adverse response or consequence (p>0.05)., Conclusions: This research offers evidence that ultra-early interventional electroacupuncture rehabilitation therapy may be an effective and safe method of treatment for individuals who have had a cerebral infarction after receiving intravenous thrombolysis. The results lend credence to the notion that this kind of therapy should be taken into consideration as an adjunctive model for rehabilitation in patients of this type.
- Published
- 2023
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11. Formal (4+2) cycloaddition of azoalkenes with trifluoromethylimidoyl sulfoxonium ylides: synthesis of trifluoromethyl pyridazine derivatives.
- Author
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Wang J, Wang SS, Xiao J, He YJ, Wu XY, Li X, and Liu PN
- Abstract
CF
3 -substituted imidoyl sulfoxonium ylides (TFISYs) are extraordinarily versatile and powerful synthons for use in cyclization chemistry that affords diverse CF3 -substituted N-heterocycles. We first reacted TFISYs as a two-atom synthon with readily available azoalkenes and then subjected the products to metal-free formal (4+2) cycloaddition chemistry. This protocol features mild conditions and broad substrate scope, is simple to operate, and provides highly functionalized trifluoromethylpyridazines that are widely found in bioactive molecules.- Published
- 2023
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12. Two-Dimensional Crystal Transition from Radialene to Cumulene on Ag(111) via Retro-[2 + 1] Cycloaddition.
- Author
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Liu JW, Wang Y, Kang LX, Zhao Y, Xing GY, Huang ZY, Zhu YC, Li DY, and Liu PN
- Abstract
Two-dimensional (2D) crystal-to-crystal transition is an important method in crystal engineering because of its ability to directly create diverse crystal materials from one crystal. However, steering a 2D single-layer crystal-to-crystal transition on surfaces with high chemo- and stereoselectivity under ultra-high vacuum conditions is a great challenge because the transition is a complex dynamic process. Here, we report a highly chemoselective 2D crystal transition from radialene to cumulene with retention of stereoselectivity on Ag(111) via retro-[2 + 1] cycloaddition of three-membered carbon rings and directly visualize the transition process involving a stepwise epitaxial growth mechanism by the combination of scanning tunneling microscopy and non-contact atomic force microscopy. Using progression annealing, we found that isocyanides on Ag(111) at a low annealing temperature underwent sequential [1 + 1 + 1] cycloaddition and enantioselective molecular recognition based on C-H···Cl hydrogen bonding interactions to form 2D triaza[3]radialene crystals. In contrast, a higher annealing temperature induced the transformation of triaza[3]radialenes to generate trans -diaza[3]cumulenes, which were further assembled into 2D cumulene-based crystals through twofold N-Ag-N coordination and C-H···Cl hydrogen bonding interactions. By combining the observed distinct transient intermediates and density functional theory calculations, we demonstrate that the retro-[2 + 1] cycloaddition reaction proceeds via the ring opening of a three-membered carbon ring, sequential dechlorination/hydrogen passivation, and deisocyanation. Our findings provide new insights into the growth mechanism and dynamics of 2D crystals and have implications for controllable crystal engineering.
- Published
- 2023
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13. Commercial and novel anticoagulant ECMO coatings: a review.
- Author
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Zhao CY, Sheng KJ, Bao T, Shi T, Liu PN, Yan Y, and Zheng XL
- Subjects
- Humans, Anticoagulants pharmacology, Anticoagulants therapeutic use, Blood Coagulation, Hemorrhage drug therapy, Extracorporeal Membrane Oxygenation adverse effects, Thrombosis drug therapy, Thrombosis chemically induced
- Abstract
Extracorporeal membrane oxygenation (ECMO) is an invasive and last-resort treatment for circulatory and respiratory failure. Prolonged ECMO support can disrupt the coagulation and anticoagulation systems in a patient, leading to adverse consequences, such as bleeding and thrombosis. To address this problem, anticoagulation coatings have been developed for use in ECMO circuits. This article reviews commonly used commercial and novel anticoagulant coatings developed in recent years and proposes a new classification of coatings based on the current state. While commercial coatings have been used clinically for decades, this review focuses on comparing the effectiveness and stability of coatings to support clinical selections. Furthermore, novel anticoagulation coatings often involve complex mechanisms and elaborate design strategies, and this review summarises representative studies on mainstream anticoagulation coatings to provide a point of reference for future studies.
- Published
- 2023
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14. On-Surface Cross-Coupling Reactions.
- Author
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Xing GY, Zhu YC, Li DY, and Liu PN
- Abstract
On-surface synthesis, as a bottom-up synthetic method, has been proven to be a powerful tool for atomically precise fabrication of low-dimensional carbon nanomaterials over the past 15 years. This method relies on covalent coupling reactions that occur on solid substrates such as metal or metal oxide surfaces under ultra-high-vacuum conditions, and the achievements with this method have greatly enriched fundamental science and technology. However, due to the complicated reactivity of organic groups, distinct diffusion of reactants and intermediates, and irreversibility of covalent bonds, achieving the high selectivity of covalent coupling reactions on surfaces remains a great challenge. As a result, only a few on-surface covalent coupling reactions, mainly involving dehalogenation and dehydrogenation homocoupling, are frequently used in the synthesis of low-dimensional carbon nanosystems. In this Perspective, we focus on the development and synthetic applications of on-surface cross-coupling reactions, mainly Ullmann, Sonogashira, Heck, and divergent cross-coupling reactions.
- Published
- 2023
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15. A p-orbital honeycomb-Kagome lattice realized in a two-dimensional metal-organic framework.
- Author
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Wang XB, Xia B, Lyu CK, Kim D, Li E, Fu SQ, Chen JY, Liu PN, Liu F, and Lin N
- Abstract
The experimental realization of p-orbital systems is desirable because p-orbital lattices have been proposed theoretically to host strongly correlated electrons that exhibit exotic quantum phases. Here, we synthesize a two-dimensional Fe-coordinated bimolecular metal-organic framework which constitutes a honeycomb lattice of 1,4,5,8,9,12-hexaazatriphenylene molecules and a Kagome lattice of 5,15-di(4-pyridyl)-10,20-diphenylporphyrin molecules on a Au(111) substrate. Density-functional theory calculations show that the framework features multiple well-separated spin-polarized Kagome bands, namely Dirac cone bands and Chern flat bands, near the Fermi level. Using tight-binding modelling, we reveal that these bands are originated from two effects: the low-lying molecular orbitals that exhibit p-orbital characteristics and the honeycomb-Kagome lattice. This study demonstrates that p-orbital Kagome bands can be realized in metal-organic frameworks by using molecules with molecular orbitals of p-orbital like symmetry., (© 2023. The Author(s).)
- Published
- 2023
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16. Collective Quantum Magnetism in Nitrogen-Doped Nanographenes.
- Author
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Zhu G, Jiang Y, Wang Y, Wang BX, Zheng Y, Liu Y, Kang LX, Li Z, Guan D, Li Y, Zheng H, Liu C, Jia J, Lin T, Liu PN, Li DY, and Wang S
- Abstract
The emergence of quantum magnetism in nanographenes provides ample opportunities to fabricate purely organic devices for spintronics and quantum information. Although heteroatom doping is a viable way to engineer the electronic properties of nanographenes, the synthesis of doped nanographenes with collective quantum magnetism remains elusive. Here, a set of nitrogen-doped nanographenes (N-NGs) with atomic precision are fabricated on Au(111) through a combination of imidazole [2+2+2]-cyclotrimerization and cyclodehydrogenation reactions. High-resolution scanning probe microscopy measurements reveal the presence of collective quantum magnetism for nanographenes with three radicals, with spectroscopic features which cannot be captured by mean-field density functional theory calculations but can be well reproduced by Heisenberg spin model calculations. In addition, the mechanism of magnetic exchange interaction of N-NGs has been revealed and compared with their counterparts with pure hydrocarbons. Our findings demonstrate the bottom-up synthesis of atomically precise N-NGs which can be utilized to fabricate low-dimensional extended graphene nanostructures for realizing ordered quantum phases.
- Published
- 2023
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17. Rhodium-Catalyzed 1,4-Aryl Rearrangement of Sulfur Ylide for the Synthesis of 2-Pyridyl Thioethers.
- Author
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Wang J, Li QY, Wang SS, Wu XY, Li X, and Liu PN
- Abstract
We report a novel rhodium-catalyzed rearrangement involving N-substituted 2-thiopyridones and diazoesters. This reaction proceeds through the rhodium-catalyzed formation of sulfur ylides, followed by a direct C-N bond cleavage to achieve N-to-C 1,4-pyridyl migration. The protocol can be used to construct various thiopyridines possessing tetrasubstituted carbon stereocenters in moderate to excellent yields, which expands the transformation pattern of sulfur ylide intermediates in rearrangement reactions.
- Published
- 2023
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18. Management principles of cranial base tumor with aneurysm.
- Author
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Ma X, Zhang Y, Zhang C, Yang ZJ, and Liu PN
- Subjects
- Male, Female, Humans, Adult, Middle Aged, Retrospective Studies, Treatment Outcome, Skull Base surgery, Skull Base Neoplasms surgery, Aneurysm
- Abstract
Skull base tumors are challenging to treat because of their deep location, complex anatomy, and close proximity to important blood vessels and nerves. Furthermore, some patients with cranial tumors are found to have aneurysms, but there is no consensus on how to evaluate the impact of aneurysms on surgery and how to handle the lesions safely and effectively. We retrospectively reviewed our database to identify all patients with a skull base tumor treated in the Department of Neurosurgery of Beijing Tiantan Hospital affiliated with Capital Medical University from 2019 to 2021. The records of patients with skull base tumors associated with aneurysms were analyzed. The operative methods and postoperative follow-up information were collected. We analyzed a total of 481 patients with skull base tumors, comprising 224 males and 257 females with a mean age of 48 ± 14 years. Twenty-four patients (24/481, 5.0%) were diagnosed with aneurysms. For eight patients, it was considered necessary to perform aneurysm treatment before or during the tumor resection surgery. For the other 16 patients, the recommendation was to monitor the aneurysm or perform elective aneurysm treatment after tumor resection. All patients with both skull base tumors and aneurysms benefited from treatment. No severe postoperative complications occurred. We summarized the final treatment plan for all patients with skull base tumors with aneurysms and proposed a protocol to decrease the surgical risk of patients with skull base tumors associated with aneurysms., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)
- Published
- 2023
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19. Surgical outcomes and prognostic factors of parasagittal meningioma: a single-center experience 165 consecutive cases.
- Author
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Wang B, Zhang GJ, Wu Z, Zhang JT, and Liu PN
- Subjects
- Humans, Male, Female, Middle Aged, Prognosis, Retrospective Studies, Treatment Outcome, Neoplasm Recurrence, Local, Meningioma pathology, Meningeal Neoplasms surgery, Meningeal Neoplasms pathology
- Abstract
Purpose: This study aimed to estimate the prognostic factors, long-term outcomes, and surgical strategies for parasagittal meningioma (PSM) and provide a better understanding of surgical experience., Materials and Methods: Patients ( n = 1438) who underwent surgery for meningioma between January 2012 and January 2013 were enrolled in a database. We then identified 165 patients with PSM based on this database., Results: Of the 165 patients with identified PSMs, 103 were female and 62 were male, with a mean age of 49 years. Univariate analysis revealed that male sex ( p = .002), non-World Health Organization (WHO) grade I meningioma ( p < .001), treatment history ( p = .006), surgical time more than 232 minutes ( p = .006), and intraoperative bleeding > 300mL
3 ( p = .019) were associated with decreased progression-free survival (PFS). Multivariate analysis revealed that sex (hazards ratio [HR] = 3.836, 95% confidence interval [CI] = 1.364-10.794; p = .011], tumour grade (HR = 8.479, 95% CI = 3.234-22.230; p < .001), and surgical time (HR = 3.710, 95% CI = 1.057-13.023; p = .041) were independent factors for PFS. Patients with Simpson grade I-II ( p = .015), no-treatment history ( p = .006), tumour size < 3cm ( p = .005), surgical time < 232 minutes ( p = .019), intraoperative bleeding < 300mL3 ( p < .001), or WHO grade I meningioma ( p = .002) had better follow-up conditions., Conclusion: Surgery was an effective treatment for PSM, and at the time of final follow-up, patients who received aggressive resection had a substantially higher Karnofsky performance scale score.- Published
- 2022
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20. Synthesis of Dendronized Polymers on the Au(111) Surface.
- Author
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Zhu YC, Xue FH, Kang LX, Liu JW, Wang Y, Li DY, and Liu PN
- Abstract
Dendronized polymers (DPs) consist of a linear polymeric backbone with dendritic side chains. Fine-tuning of the functional groups in the side chains enriches the structural versatility of the DPs and imparts a variety of novel physical properties. Herein, the first on-surface synthesis of DPs is achieved via the postfunctionalization of polymers on Au(111), in which the surface-confinement-induced planar conformation and chiral configurations were unambiguously characterized. While the dendronized monomer was synthesized in situ on Au(111), the subsequent polymerization afforded only short, cross-linked DP chains owing to multiple side reactions. The postfunctionalization approach selectively produced brominated polyphenylene backbone moieties by the deiodination polymerization of 4-bromo-4″-iodo-5'-(4-iodophenyl)-1,1':3',1″-terphenyl on Au(111), which smoothly underwent divergent cross-coupling reactions with two different isocyanides to form two types of DPs as individual long chains.
- Published
- 2022
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21. Highly Efficient and para -Selective C-H Functionalization of Polystyrene Providing a Versatile Platform for Diverse Applications.
- Author
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Xue B, Huang PP, Zhu MZ, Fu SQ, Ge JH, Li X, and Liu PN
- Abstract
Postpolymerization modification of polystyrene (PS) can afford numerous value-added materials with different functions and applications, but it has been hampered by the lack of efficient methods. We report herein a highly efficient and para -selective conversion of the C-H bonds of the aromatic ring of PS into diverse functional groups using a combination of thianthrenation and thio-Suzuki-Miyaura coupling reaction. Notably, the thianthrenation efficiency of PS is as high as 99% and the degree of thianthrenation can be conveniently controlled using stoichiometric tuning of the amount of thianthrene- S -oxide added, resulting in 24-99 mol % thianthrenation. In the subsequent thio-Suzuki-Miyaura coupling reaction, 18 functionalized PS containing various functional groups (-CH
2 OH, -OMe, -SMe, -OTBS, -CH3 , -NHBoc, -OCOMe, -CHO, -COMe, -Si(Me)3 , etc.) were successfully prepared with a high degree of functionalization (64-99 mol %). The obtained functionalized PS can be readily converted into diverse functional materials, including solid-phase synthesis resins, aggregation-induced emission fluorophores, as well as ionomer binders and ion-exchange membranes for energy conversion devices. This method imparts diverse functionality onto PS with extremely high efficiency and selectivity, providing a versatile platform to transform existing commodity PS plastics into high-performance materials.- Published
- 2022
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22. Phase II trial of icotinib in adult patients with neurofibromatosis type 2 and progressive vestibular schwannoma.
- Author
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Zhao F, Li SW, Zhang S, Li P, Zhao C, Zhao XB, Wang CH, Zhang J, Wang B, and Liu PN
- Abstract
Objective: Neurofibromatosis type 2 (NF2) is a rare autosomal dominant syndrome associated primarily with bilateral vestibular schwannomas (VSs). Conventional surgical or radiosurgical treatments for VS in NF2 usually result in high risks of hearing loss and facial nerve impairment, while there is no validated medical option to date. This single-institution phase II study evaluated the efficacy and safety of icotinib, an oral epidermal growth factor receptor tyrosine kinase inhibitor, in patients with NF2 and progressive VS., Methods: Icotinib was administered daily at 375 mg orally in a continuous 28-day course for up to 12 courses. The primary endpoint of the study was radiographic response assessed by brain MRI using 3D volumetric tumor analysis and defined as a ≥ 20% decrease in VS volume. Hearing function was evaluated as a secondary endpoint, with response defined as a statistically significant increase in word recognition scores., Results: Ten eligible patients with a mean age of 23.8 years were enrolled. One patient (10%) with bilateral tumors experienced an objective radiographic response (-23.58% and -22.01%). Three (43%) of 7 patients met the hearing response criteria. At 12 months, the estimated progression-free survival was 82.0% (95% CI 42.3%-95.5%) for volumetric progression and 69.2% (95% CI 37.3%-87.2%) for hearing progression. Common mild to moderate adverse events included rash (90%), diarrhea (50%), myalgia (20%), and nausea/gastrointestinal pain (20%)., Conclusions: Icotinib carries minor toxicity and is associated with radiographic and hearing responses in patients with NF2 and progressive VS.
- Published
- 2022
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23. A Comprehensive Study of Gradient Conditions for Deep Proteome Discovery in a Complex Protein Matrix.
- Author
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Wei X, Liu PN, Mooney BP, Nguyen TT, and Greenlief CM
- Subjects
- Chromatography, Liquid methods, Complex Mixtures, HeLa Cells, Humans, Peptides analysis, Proteome analysis, Tandem Mass Spectrometry methods
- Abstract
Bottom-up mass-spectrometry-based proteomics is a well-developed technology based on complex peptide mixtures from proteolytic cleavage of proteins and is widely applied in protein identification, characterization, and quantitation. A tims-ToF mass spectrometer is an excellent platform for bottom-up proteomics studies due to its rapid acquisition with high sensitivity. It remains challenging for bottom-up proteomics approaches to achieve 100% proteome coverage. Liquid chromatography (LC) is commonly used prior to mass spectrometry (MS) analysis to fractionate peptide mixtures, and the LC gradient can affect the peptide fractionation and proteome coverage. We investigated the effects of gradient type and time duration to find optimal gradient conditions. Five gradient types (linear, logarithm-like, exponent-like, stepwise, and step-linear), three different gradient lengths (22 min, 44 min, and 66 min), two sample loading amounts (100 ng and 200 ng), and two loading conditions (the use of trap column and no trap column) were studied. The effect of these chromatography variables on protein groups, peptides, and spectral counts using HeLa cell digests was explored. The results indicate that (1) a step-linear gradient performs best among the five gradient types studied; (2) the optimal gradient duration depends on protein sample loading amount; (3) the use of a trap column helps to enhance protein identification, especially low-abundance proteins; (4) MSFragger and PEAKS Studio have high similarity in protein group identification; (5) MSFragger identified more protein groups among the different gradient conditions compared to PEAKS Studio; and (6) combining results from both database search engines can expand identified protein groups by 9-11%.
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- 2022
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24. Qu-Du-San-Jie decoction induces growth inhibition and vascular normalization in NF2-associated vestibular schwannoma.
- Author
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Lin J, Li SW, Zhang J, Chu FH, Li CZ, Bie ZX, Tang HL, Gao S, Li P, Liao MT, Xin TX, Zhao F, Liu PN, and Ding X
- Abstract
Background: Neurofibromatosis type 2 (NF2) is a rare genetic syndrome that predisposes individuals to develop bilateral vestibular schwannomas (VSs) causing a high risk of life-threatening neurological complications. Traditional treatment options for NF2-associated VS usually cause neurological damage, and to date, there are no FDA-approved pharmacotherapies for NF2. The aim of this study was to evaluate the antitumor efficacy of Qu-Du-San-Jie (QDSJ) decoction, a traditional Chinese medicine formula, on NF2-associated VS and to investigate the potential underlying mechanisms. Methods: Ultra high-performance liquid chromatography-mass spectroscopy (UHPLC-MS) analysis was performed to identify the components of QDSJ and their targets. To determine the relationships between the putative targets of QDSJ and the differential genes of NF2-associated VS, the drug-disease crossover genes were screened using the UHPLC-MS data combined with our previous gene expression profiling data. The differentially expressed genes were imported into the STRING database to generate a PPI network. Differentially expressed gene targets and pathways were identified using GO and KEGG pathway enrichment analyses. The in vitro and in vivo drug efficacy of QDSJ decoction was tested using a patient-derived schwannoma cell line and a patient-derived xenograft mouse model, respectively. H&E staining, immunochemistry, and immunofluorescence staining were used to evaluate the cell proliferation and tumor vessels. Results: A total of 133 compounds were identified in QDSJ decoction using UHPLC-MS analysis. Network pharmacology showed that the regulation of necroptosis, apoptosis, cell cycle, angiogenesis, adherens junction, and neuroactive ligand-receptor interaction could be associated with the efficacy of QDSJ in treating NF2-associated VS. Treatment with QDSJ induced necrotic cell death and apoptosis of schwannoma cells in vitro and suppressed the tumor growth in vivo . Histopathological analysis revealed areas of cell necrosis and enlarged tumor blood vessels in the QDSJ-treated tumors. The numbers of cells positive for Cyclin D1 and Ki-67 were significantly reduced in QDSJ-treated tumors compared to control tumors. Immunofluorescence staining of CD31 and αSMA showed a decreased number and density of tumor vessels and normalized vessel structure in QDSJ-treated tumors. Conclusion: Our study demonstrates that QDSJ decoction shows significant antitumor activity against NF2-associated schwannoma and is a possible candidate for future clinical trials., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Lin, Li, Zhang, Chu, Li, Bie, Tang, Gao, Li, Liao, Xin, Zhao, Liu and Ding.)
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- 2022
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25. Novel patient-derived xenograft and cell line models for therapeutic screening in NF2-associated schwannoma.
- Author
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Zhao F, Chen Y, Li SW, Zhang J, Zhang S, Zhao XB, Yang ZJ, Wang B, He QY, Wang LM, Xu L, and Liu PN
- Subjects
- Cell Line, Heterografts, Humans, Phosphatidylinositol 3-Kinases metabolism, Proto-Oncogene Proteins c-akt metabolism, TOR Serine-Threonine Kinases genetics, Neurilemmoma drug therapy, Neurilemmoma genetics, Neurofibromatosis 2 drug therapy, Neurofibromatosis 2 genetics, Neurofibromatosis 2 pathology
- Abstract
Treatment of schwannomas in patients with neurofibromatosis type 2 (NF2) is extremely unsatisfactory, and innovative therapeutic approaches are urgently needed. However, the lack of clinically relevant NF2-associated schwannoma models has severely hampered drug discovery in this rare disease. Here we report the first establishment and characterization of patient-derived xenograft (PDX) and cell line models of NF2-associated schwannoma, which recapitulates the morphological and histopathological features of patient tumors, retain patient NF2 mutations, and maintain gene expression profiles resembling patient tumor profiles with the preservation of multiple key signaling pathways commonly dysregulated in human schwannomas. Using gene expression profiling, we identified elevated PI3K/AKT/mTOR networks in human NF2-associated vestibular schwannomas. Using high-throughput screening of 157 inhibitors targeting the PI3K/AKT/mTOR pathways in vitro, we identified a dozen inhibitors (such as BEZ235, LY2090314, and AZD8055) with significant growth-suppressive effects. Interestingly, we observed that three cell lines displayed differential therapeutic responses to PI3K/AKT/mTOR inhibitors. Furthermore, we demonstrated that two orally bioavailable inhibitors, AZD8055 and PQR309, suppressed NF2-associated schwannoma growth both in vitro and in vivo. In conclusion, our novel patient-derived models of NF2-associated schwannoma closely mimic the phenotypes and genotypes of patient tumors, making them reliable preclinical tools for testing novel personalized therapies. © 2022 The Pathological Society of Great Britain and Ireland., (© 2022 The Pathological Society of Great Britain and Ireland.)
- Published
- 2022
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26. Synthesis of Single-Layer Two-Dimensional Metal-Organic Frameworks M 3 (HAT) 2 (M=Ni, Fe, Co, HAT=1,4,5,8,9,12-hexaazatriphenylene) Using an On-Surface Reaction.
- Author
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Lyu CK, Gao YF, Gao ZA, Mo SY, Hua MQ, Li E, Fu SQ, Chen JY, Liu PN, Huang L, and Lin N
- Abstract
1,4,5,8,9,12-Hexaazatriphenylene (HAT) is one of the smallest polyheterocyclic aromatic building blocks for forming conjugated metal-organic frameworks (cMOFs). However, the strong inter-molecular steric hindrance impedes the growth of HAT-based cMOFs. Here we employ on-surface synthesis to grow single-layer two-dimensional cMOFs of M
3 (HAT)2 (M=Ni, Fe, Co). Using scanning tunnelling microscopy and density-functional theory (DFT) analysis, we resolve that the frameworks comprise a hexagonal lattice of HAT molecules and a Kagome lattice of metal atoms. The DFT analysis indicates that Ni, Co and Fe carry a magnetic moment of 1.1, 2.5, and 3.7 μB, respectively. We anticipate that the small π-conjugated core of HAT and strong bidentate chelating coordination give rise to appealing electronic and magnetic properties., (© 2022 Wiley-VCH GmbH.)- Published
- 2022
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27. On-Surface Synthesis of [3]Radialenes via [1+1+1] Cycloaddition.
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Li DY, Wang Y, Hou XY, Ren YT, Kang LX, Xue FH, Zhu YC, Liu JW, Liu M, Shi XQ, Qiu X, and Liu PN
- Abstract
[3]Radialenes are the smallest carbocyclic structures with unusual topologies and cross-conjugated π-electronic structures. Here, we report a novel [1+1+1] cycloaddition reaction for the synthesis of aza[3]radialenes on the Ag(111) surface, where the steric hindrance of the chlorine substituents guides the selective and orientational assembling of the isocyanide precursors. By combining scanning tunneling microscopy, non-contact atomic force microscopy, and time-of-flight secondary ion mass spectrometry, we determined the atomic structure of the produced aza[3]radialenes. Furthermore, two reaction pathways including synergistic and stepwise are proposed based on density functional theory calculations, which reveal the role of the chlorine substituents in the activation of the isocyano groups via electrostatic interaction., (© 2022 Wiley-VCH GmbH.)
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- 2022
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28. Direct Access to Bridged Polycyclic Skeletons by Merging Oxidative C-H Annulation and Cascade [4 + 2] Cycloaddition.
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He Y, Wang H, Xu L, Li DY, Ge JH, Feng DF, Feng W, Zou G, and Liu PN
- Abstract
We report a step-economic strategy for the direct synthesis of bridged polycyclic skeletons by merging oxidative C-H annulation and cascade cycloaddition. In the protocol, spiro[cyclopentane-1,3'-indoline]-2,4-dien-2'-ones were first synthesized by oxidative C-H annulation of ethylideneoxindoles with alkynes. Subsequent cascade [4 + 2] cycloaddition with dienophiles gave the bridged bicyclo[2.2.1]quinolin-2(1 H )-ones and enabled the one-pot construction of two quaternary carbon centers and three C-C bonds. Mechanistic investigations of the latter suggest a cascade ring-opening, 1,5-sigmatropic rearrangement, and [4 + 2] cycloaddition process.
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- 2022
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29. Mapping Oxidation and Wafer Cleaning to Device Characteristics Using Physics-Assisted Machine Learning.
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Pratik S, Liu PN, Ota J, Tu YL, Lai GW, Ho YW, Yang ZK, Rawat TS, and Lin AS
- Abstract
It is always highly desired to have a well-defined relationship between the chemistry in semiconductor processing and the device characteristics. With the shrinkage of technology nodes in the semiconductors roadmap, it becomes more complicated to understand the relation between the device electrical characteristics and the process parameters such as oxidation and wafer cleaning procedures. In this work, we use a novel machine learning approach, i.e., physics-assisted multitask and transfer learning, to construct a relationship between the process conditions and the device capacitance voltage curves. While conventional semiconductor processes and device modeling are based on a physical model, recently, the machine learning-based approach or hybrid approaches have drawn significant attention. In general, a huge amount of data is required to train a machine learning model. Since producing data in the semiconductor industry is not an easy task, physics-assisted artificial intelligence has become an obvious choice to resolve these issues. The predicted C - V uses the hybridization of physics, and machine learning provides improvement while the coefficient of determination ( R
2 ) is 0.9442 for semisupervised multitask learning (SS-MTL) and 0.9253 for transfer learning (TL), referenced to 0.6108 in the pure machine learning model using multilayer perceptrons. The machine learning architecture used in this work is capable of handling data sparsity and promotes the usage of advanced algorithms to model the relationship between complex chemical reactions in semiconductor manufacturing and actual device characteristics. The code is available at https://github.com/albertlin11/moscapssmtl., Competing Interests: The authors declare no competing financial interest., (© 2022 The Authors. Published by American Chemical Society.)- Published
- 2022
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30. Establishment of nomograms for the prediction of useful hearing loss in patients with neurofibromatosis type 2.
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Li SW, Zhang J, Tang HL, Li P, Wang B, Zhao F, and Liu PN
- Subjects
- Deafness, Humans, Nomograms, Prognosis, Prospective Studies, ROC Curve, Retrospective Studies, Hearing Loss diagnosis, Hearing Loss epidemiology, Hearing Loss etiology, Neurofibromatosis 2 complications, Neurofibromatosis 2 diagnosis, Neuroma, Acoustic complications, Neuroma, Acoustic diagnosis, Neuroma, Acoustic surgery
- Abstract
Introduction: Treatment for vestibular schwannoma (VS) in patients with neurofibromatosis type 2 (NF2) is extremely challenging due to the high risk of hearing loss. The aim of this study was to develop nomograms for the prediction of useful hearing loss in patients with NF2., Methods: The nomogram was based on a retrospective study of 111 NF2 patients who underwent resection of large VS (> 2 cm) at Beijing Tiantan Hospital between 2011 and 2018. The utility of the proposed nomogram models was evaluated by receiver operating characteristic (ROC) curve, area under ROC curve (AUC), and calibration curve. The results were validated using a prospective cohort study on 33 patients consecutively enrolled at the same institution from 2019 to 2021., Results: On multivariate analysis of the primary cohort, large tumour size (> 3 cm) and long duration of symptoms (> 24 months) were independent risk factors for preoperative useful hearing loss (AAO-HNS Class D) (P = 0.001 and P = 0.011, respectively), while large tumour size (> 3 cm), poor hearing (Class C), and lobular growth were significantly related to postoperative useful hearing loss (P < 0.001, P = 0.031 and P = 0.033, respectively). Factors derived from multivariable analysis were all assembled into the nomogram. The calibration curve for probability of hearing loss showed good agreement between predictions by nomogram models and actual observation. The ROC curves showed good predictive accuracy of the nomogram models in both cohorts (AUC: 0.708 to 0.951)., Conclusion: The proposed nomograms resulted in accurate predictions of hearing outcomes for patients with NF2., (© 2021. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)
- Published
- 2021
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31. Steering Metal-Organic Network Structures through Conformations and Configurations on Surfaces.
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Li SW, Zhang RX, Kang LX, Li DY, Xie YL, Wang CX, and Liu PN
- Abstract
Molecular adsorption conformations and arrangement configurations on surfaces are important structural aspects of surface stereochemistry, but their roles in steering the structures of metal-organic networks (MONs) remain vague and unexplored. In this study, we constructed MONs by the coordination self-assembly of isocyanides on Cu(111) and Ag(111) surfaces and demonstrated that the MON structures can be steered by surface stereochemistry, including the adsorption conformations of the isocyanide molecules and the arrangement configurations of the coordination nodes and subunits. The coordination self-assembly of 1,4-phenylene diisocyanobenzene afforded a honeycomb MON consisting of 3-fold (isocyano)
3 -Cu motifs on a Cu(111) surface. In contrast, geometrically different chevron-shaped 1,3-phenylene diisocyanobenzene ( m -DICB) failed to generate a MON, which is ascribable to its standing conformation on the Cu(111) surface. However, m -DICB was adsorbed in a flat conformation on a Ag(111) surface, which has a larger lattice constant than a Cu(111) surface, and smoothly underwent coordination self-assembly to form a MON consisting of (isocyano)3 -Ag motifs. Interestingly, only C3 -Ag nodes with heterotactic configurations could grow into larger subunits; those subunits with heterotactic configurations further grew into Sierpiński triangle fractals (up to fourth order), while subunits with homotactic configurations afforded a triangular MON.- Published
- 2021
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32. Ladder Phenylenes Synthesized on Au(111) Surface via Selective [2+2] Cycloaddition.
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Li DY, Qiu X, Li SW, Ren YT, Zhu YC, Shu CH, Hou XY, Liu M, Shi XQ, Qiu X, and Liu PN
- Abstract
Ladder phenylenes (LPs) composed of alternating fused benzene and cyclobutadiene rings have been synthesized in solution with a maximum length no longer than five units. Longer polymeric LPs have not been obtained so far because of their poor stability and insolubility. Here, we report the synthesis of linear LP chains on the Au(111) surface via dehalogenative [2+2] cycloaddition, in which the steric hindrance of the methyl groups in the 1,2,4,5-tetrabromo-3,6-dimethylbenzene precursor improves the chemoselectivity as well as the orientation orderliness. By combining scanning tunneling microscopy and noncontact atomic force microscopy, we determined the atomic structure and the electronic properties of the LP chains on the metallic substrate and NaCl/Au(111). The tunneling spectroscopy measurements revealed the charged state of chains on the NaCl layer, and this finding is supported by density functional theory calculations, which predict an indirect bandgap and antiferromagnetism in the polymeric LP chains.
- Published
- 2021
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33. Pd-Catalyzed Direct C-H Activation for the C5-Olefination of Methyleneindolinones.
- Author
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Xu XK, Liu JW, Li DY, and Liu PN
- Subjects
- Catalysis, Kinetics, Ligands, Palladium
- Abstract
The direct C-H activation without directing groups can realize the para -selectivity, which is a powerful and concise approach for functionalization of arenes. Utilizing the strategy, a C5-olefination of methyleneindolinones has been successfully developed by palladium-catalyzed direct C-H activation, which provides an expeditious access to 5-vinylindolin-2-ones with high regioselectivity. The protocol is distinguished by a mild reaction system avoiding ligand and high temperature. The kinetic isotope experiments indicate that the C-H bond cleavage is the rate-limiting step.
- Published
- 2021
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34. Post-Functionalization of Supramolecular Polymers on Surface and the Chiral Assembly-Induced Enantioselective Reaction.
- Author
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Li DY, Zhu YC, Li SW, Shu CH, and Liu PN
- Abstract
Although post-functionalization is extensively used to introduce diverse functional groups into supramolecular polymers (SPs) in solution, post-functionalization of SPs on surfaces still remains unexplored. Here we achieved the on-surface post-functionalization of two SPs derived from 5,10,15-tri-(4-pyridyl)-20-bromophenyl porphyrin (Br-TPyP) via cross-coupling reactions on Au(111). The ladder-shaped, Cu-coordinated SPs preformed from Br-TPyP were functionalized through Heck reaction with 4-vinyl-1,1'-biphenyl. In the absence of Cu, Br-TPyP formed chiral SPs as two enantiomers via self-assembly, which were functionalized via divergent cross-coupling reaction with 4-isocyano-1,1'-biphenyl (ICBP). Surprisingly, this reaction was discovered as an enantioselective on-surface reaction induced by the chirality of SPs. Mechanistic analysis and DFT calculations indicated that after debromination of Br-TPyP and the first addition of ICBP, only one attack direction of ICBP to the chiral SP intermediate is permissive in the second addition step due to the steric hindrance, which guaranteed the high enantioselectivity of the reaction., (© 2021 Wiley-VCH GmbH.)
- Published
- 2021
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35. Epidemiological characteristics and risk factors of nosocomial carbapenem-resistant Enterobacteriaceae infections in children.
- Author
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Li Z, Lin XX, Liu CX, Ye WJ, Liu PN, Li HY, and Dong L
- Subjects
- Anti-Bacterial Agents pharmacology, Anti-Bacterial Agents therapeutic use, Carbapenems, Child, Humans, Microbial Sensitivity Tests, Risk Factors, beta-Lactamases, Carbapenem-Resistant Enterobacteriaceae, Cross Infection drug therapy, Cross Infection epidemiology, Enterobacteriaceae Infections drug therapy, Enterobacteriaceae Infections epidemiology
- Published
- 2020
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36. Atomic-Scale Visualization of Stepwise Growth Mechanism of Metal-Alkynyl Networks on Surfaces.
- Author
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Shu CH, He Y, Zhang RX, Chen JL, Wang A, and Liu PN
- Abstract
One of the most appealing topics in the study of metal-organic networks is the growth mechanism. However, its study is still considered a significant challenge. Herein, using scanning tunneling microscopy, the growth mechanisms of metal-alkynyl networks on Ag(111) and Au(111) surfaces were investigated at the atomic scale. During the reaction of 1,3,5-tris(chloroethynyl)benzene on Ag(111), honeycomb Ag-alkynyl networks formed at 393 K, and only short chain intermediates were observed. By contrast, the same precursor formed honeycomb Au-alkynyl networks on Au(111) at 503 K. Progression annealing led to a stepwise evolution process, in which the sequential activation of three Cl-alkynyl bonds led to the formation of dimers, zigzag chains, and novel chiral networks as the intermediates. Moreover, density functional theory calculations indicate that chlorine atoms are crucial in assisting the breakage of metal-alkynyl bonds to form Cl-metal-alkynyl, which guarantees the reversibility of the break/formation equilibration as the key to forming regular large-scale organometallic networks.
- Published
- 2020
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37. Construction of multiple bonds via a domino reaction of trifluoroacetimidoyl nitriles with in situ generated bis-nucleophiles.
- Author
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Li DY, Chen JY, Feng DF, Chen S, Xu XK, Dang L, and Liu PN
- Abstract
A transition-metal-free double addition/double rearrangement domino reaction affording CF3-substituted pyrimidines was developed, which enables the one-pot construction of five new bonds, namely three C-C bonds and two C-N bonds. The keys to achieve this highly efficient reaction include the delicate design of the bis-nucleophiles in situ generated from the dimerization of alkyl nitriles and the use of trifluoroacetimidoyl nitriles containing C[double bond, length as m-dash]N, C[triple bond, length as m-dash]N, and CF3 groups as the reactant. The mechanistic studies by the experiments and DFT calculations reveal that the transformation involves two addition and two unprecedented rearrangement processes.
- Published
- 2020
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38. Tuning Vinylethylene Carbonates into [4 + 2] Cycloaddition via Silylation and Vinylogous Peterson Elimination.
- Author
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Feng W, Xu L, Li DY, and Liu PN
- Abstract
Vinylethylene carbonates have been extensively used to trigger [3 + n ] or [5 + n ] cycloaddition via the formation of η
3 -allylic intermediates, while the important [4 + n ] cycloaddition has not been explored yet. Here, we report a new strategy to convert vinylethylene carbonates into 4-(trimethylsilyl)but-2-en-1-ols, which can readily undergo [4 + 2] cycloaddition by in situ formation of 1,3-dienes. This novel reaction involves [PdII ]-catalyzed decarboxylative silylation, [FeIII ]-catalyzed vinylogous Peterson elimination, and subsequent [4 + 2] cycloaddition to afford a multisubstituted cyclohexa-1,4-diene skeleton.- Published
- 2020
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39. Quantitative Proteomics Reveals Docosahexaenoic Acid-Mediated Neuroprotective Effects in Lipopolysaccharide-Stimulated Microglial Cells.
- Author
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Yang B, Li R, Liu PN, Geng X, Mooney BP, Chen C, Cheng J, Fritsche KL, Beversdorf DQ, Lee JC, Sun GY, and Greenlief CM
- Subjects
- Cytokines, Docosahexaenoic Acids pharmacology, Microglia, NF-kappa B genetics, Proteomics, Lipopolysaccharides pharmacology, Neuroprotective Agents
- Abstract
The high levels of docosahexaenoic acid (DHA) in cell membranes within the brain have led to a number of studies exploring its function. These studies have shown that DHA can reduce inflammatory responses in microglial cells. However, the method of action is poorly understood. Here, we report the effects of DHA on microglial cells stimulated with lipopolysaccharides (LPSs). Data were acquired using the parallel accumulation serial fragmentation method in a hybrid trapped ion mobility-quadrupole time-of-flight mass spectrometer. Over 2800 proteins are identified using label-free quantitative proteomics. Cells exposed to LPSs and/or DHA resulted in changes in cell morphology and expression of 49 proteins with differential abundance (greater than 1.5-fold change). The data provide details about pathways that are influenced in this system including the nuclear factor κ-light-chain-enhancer of the activated B cells (NF-κB) pathway. Western blots and enzyme-linked immunosorbent assay studies are used to help confirm the proteomic results. The MS data are available at ProteomeXchange.
- Published
- 2020
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40. Corona Virus International Public Health Emergencies: Implications for Radiology Management.
- Author
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Zhang HW, Yu J, Xu HJ, Lei Y, Pu ZH, Dai WC, Lin F, Wang YL, Wu XL, Liu LH, Li M, Mo YQ, Zhang H, Luo SP, Chen H, Lyu GW, Zhou ZG, Liu WM, Liu XL, Song HY, Chen FZ, Zeng L, Zhong H, Guo TT, Hu YQ, Yang XX, Liu PN, and Li DF
- Subjects
- Betacoronavirus, COVID-19, COVID-19 Testing, China epidemiology, Clinical Laboratory Techniques, Coronavirus Infections diagnosis, Humans, Pneumonia, Viral diagnosis, Radiology, SARS-CoV-2, Coronavirus Infections diagnostic imaging, Disease Outbreaks, Emergencies, Lung diagnostic imaging, Pneumonia, Viral diagnostic imaging, Public Health, Tomography, X-Ray Computed
- Abstract
The outbreak of 2019 novel coronavirus (2019-nCoV) pneumonia was reported in Wuhan, Hubei Province, China in December 2019 and has spread internationally. This article discusses how radiology departments can most effectively respond to this public health emergency., (Copyright © 2020 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.)
- Published
- 2020
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41. Bifunctional Phosphine Ligand Enabled Gold-Catalyzed Alkynamide Cycloisomerization: Access to Electron-Rich 2-Aminofurans and Their Diels-Alder Adducts.
- Author
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Li X, Ma X, Wang Z, Liu PN, and Zhang L
- Abstract
By using biphenyl-2-ylphosphines functionalized with a remote tertiary amino group as a ligand, readily available acetylenic amides are directly converted into 2-aminofurans devoid of any electron-withdrawing and hence deactivating/stabilizing substituents. These highly electron-rich furans have rarely been prepared, let alone applied in synthesis, because of their high reactivities and low stabilities associated with the electron-rich nature of the furan ring. In this work, these reactive furans smoothly undergo either in situ intermolecular Diels-Alder reactions to deliver highly functionalized/substituted aniline products or intramolecular ones to furnish carbazole-4-carboxylates in mostly good to excellent yields. This work offers general and expedient access to this class of little studies electron-rich furans and should lead to exciting opportunities for their applications., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)
- Published
- 2019
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42. [Expression of heterogeneous nuclear ribonucleo-protein A2B1 in mouse cerebellar development and human medulloblastoma].
- Author
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Zhao SL, Zhao F, Li Q, Zhang J, Zhang ZW, Li CD, Liu PN, Tong WM, and Niu YM
- Subjects
- Animals, Cell Line, Tumor, Cerebellum, Down-Regulation, Heterogeneous-Nuclear Ribonucleoprotein Group A-B, Humans, Mice, Cerebellar Neoplasms, Medulloblastoma
- Abstract
Objective: To investigate the expression and potential role of heterogeneous nuclear ribonucleo-protein A2B1 (HNRNPA2B1) in mouse cerebellar development and the significance of HNRNPA2B1 in human medulloblastoma. Methods: The data of HNRNPA2B1 RNA expression in mouse and human cerebella were obtained from databases. Western blot and immunohistochemical staining were performed to detect the protein level of HNRNPA2B1 in mouse cerebella at different ages. The expression level of HNRNPA2B1 in control human cerebellum and medulloblastoma was detected by immunohistochemical staining. m6A-IP-qPCR method was applied to confirm whether HNRNPA2B1 RNA in Daoy cells was modified with m6A.Western blot was used to detect the effect of MG132 treatment on the HNRNPA2B1 protein level in Daoy cells. Results: The level of HNRNPA2B1 protein in postnatal mouse cerebella was higher than that in adult mouse cerebella, with weak HNRNPA2B1 staining in external granular cells while strong staining in mature Purkinje cells and molecular layer. Compared with control normal human cerebella, the RNA expression level of HNRNPA2B1 increased in medulloblastoma, while immunohistochemical staining showed that the mean intensity of HNRNPA2B1 decreased in medulloblastoma. HNRNPA2B1 RNA in medulloblastoma and Daoy cells was modified by m6A. The HNRNPA2B1 protein level in Daoy cells increased upon MG132 treatment. Conclusions: HNRNPA2B1 is dynamically expressed during mouse cerebellar development. Compared with normal human cerebella, HNRNPA2B1 is significantly up-regulated at transcriptional level but obviously down-regulated at translational level in medulloblastoma. These results indicate that HNRNPA2B1 may be involved in cerebellar development process and medulloblastoma tumorigenesis. The m6A methylation in HNRNPA2B1 transcript and protein ubiquitin-proteasome pathway may account for the down-regulation of HNRNPA2B1 at protein level.
- Published
- 2019
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43. On-surface synthesis of 2D COFs on Cu(111) via the formation of thermodynamically stable organometallic networks as the template.
- Author
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Wang CX, Chen JL, Shu CH, Shi KJ, and Liu PN
- Abstract
Template-directed polymerization is an effective approach used to afford regular 2D covalent organic frameworks (COFs), thus the regularity of the template is crucial for the quality of the resulting 2D COFs. For the Ullmann reactions on Cu(111), aryl iodides and bromides are activated at low temperature to form organometallic C-Cu-C structures, which lead to kinetic trapping and irregular organometallic networks. Therefore, the subsequent annealing step can only afford irregular 2D COFs. In this manuscript, the molecule 4,4''-dibromo-5'-(4-chlorophenyl)-1,1':3',1''-terphenyl incorporated two Br terminals and one Cl terminal has been used to demonstrate different reactivities of a C-Cl bond and a C-Br bond via the hierarchical activation of the C-Br bond and the C-Cl bond on Cu(111). At room temperature, zigzag, armchair, and ring-like organometallic chains formed due to the activation of the C-Br bond to generate a C-Cu-C structure while C-Cl remained intact, illustrating that the C-Cl bond is more stable than C-Br. Further annealing at 433 K activated the C-Cl bond to produce regular organometallic networks as the thermodynamic product. Using the simpler molecule 1,3,5-tris(4-chlorophenyl)benzene as the precursor, the self-assembly of the intact molecules was observed on Cu(111) at 300 K without activation of the C-Cl bond. After annealing at 433 K, similar thermodynamically stable organometallic networks formed directly, which were used as a template to generate regular 2D COFs upon further annealing at 510 K.
- Published
- 2019
- Full Text
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44. On-surface synthesis of planar dendrimers via divergent cross-coupling reaction.
- Author
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Li DY, Li SW, Xie YL, Hua X, Long YT, Wang A, and Liu PN
- Abstract
Dendrimers are homostructural and highly branched macromolecules with unique dendritic effects and extensive use in multidisciplinary fields. Although thousands of dendrimers have been synthesized in solution, the on-surface synthetic protocol for planar dendrimers has never been explored, limiting the elucidation of the mechanism of dendritic effects at the single-molecule level. Herein, we describe an on-surface synthetic approach to planar dendrimers, in which exogenous palladium is used as a catalyst to address the divergent cross-coupling of aryl bromides with isocyanides. This reaction enables one aryl bromide to react with two isocyanides in sequential steps to generate the divergently grown product composed of a core and two branches with high selectivity and reactivity. Then, a dendron with four branches and dendrimers with eight or twelve branches in the outermost shell are synthesized on Au(111). This work opens the door for the on-surface synthesis of various planar dendrimers and relevant macromolecular systems.
- Published
- 2019
- Full Text
- View/download PDF
45. Evolution of transmaxillary approach to tumors in pterygopalatine fossa and infratemporal fossa: anatomic simulation and clinical practice.
- Author
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Xue Z, Liu J, Bi ZY, Yi ZQ, Bao SD, Liu PN, and Yang ZJ
- Subjects
- Adult, Female, Humans, Infratentorial Neoplasms surgery, Male, Middle Aged, Neuroendoscopy, Perioperative Care, Postoperative Complications, Pterygopalatine Fossa surgery, Infratentorial Neoplasms pathology, Pterygopalatine Fossa pathology
- Abstract
Background: The endoscopic transnasal approach has been proven to have advantages on the removal of the tumors in pterygopalatine fossa (PPF) and infratemporal fossa (ITF). Herein, this study aimed to describe a modified approach for resection of the tumors in these areas, both in cadaveric specimen and clinical patients., Methods: The 20 adult cadaveric specimens and five patients with tumors in PPF and ITF were enrolled in this study. For the cadaveric specimens, ten were simulated anterior transmaxillary approach and ten were performed modified endoscopic transnasal transmaxillary approach. The exposure areas were compared between two groups and main anatomic structure were measured. Surgery was operated in the five patients with tumors of PPF and ITF to verify the experience from the anatomy. Perioperative management, intraoperative findings and postoperative complications were recorded and analyzed., Results: The modified endoscopic transnasal transmaxillary approach provided as enough surgical exposure and high operability to the PPF and ITF as the anterior transmaxillary approach did. The diameter of maxillary artery in the PPF was 3.77 ± 0.78 mm (range: 2.06-4.82 mm), the diameter of middle meningeal artery in the ITF was 2.79 ± 0.61 mm (range: 1.54-3.78 mm). Four patients who suffered schwannoma got total removal and one of adenocystic carcinoma got subtotal removal. The main complications were facial numbness and pericoronitis of the wisdom tooth. No permanent complication was found., Conclusions: With the widespread use of neuroendoscopy, the modified endoscopic transnasal transmaxillary approach is feasible and effective for the resection of tumors located in PPF and ITF, which has significant advantages on less trauma and complications to the patients.
- Published
- 2019
- Full Text
- View/download PDF
46. Direct access to substituted benzo[b]carbazoles through cascade annulation of 2-vinylbenzaldehydes with indoles.
- Author
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Li DY, Wang A, Zhu XP, Feng W, and Liu PN
- Abstract
A highly efficient palladium-catalyzed cascade annulation of 2-vinylbenzaldehydes with indoles has been achieved to afford 6-(3-indolyl)benzo[b]carbazoles under mild conditions in good yield and with excellent regioselectivity. Mechanistic investigations reveal that the reaction proceeds via double addition of indoles, unexpected intramolecular 1,4-aryl and 1,2-hydrogen migrations, and oxidative aromatization.
- Published
- 2019
- Full Text
- View/download PDF
47. Synthesis and characterization of a single-layer conjugated metal-organic structure featuring a non-trivial topological gap.
- Author
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Gao Z, Hsu CH, Liu J, Chuang FC, Zhang R, Xia B, Xu H, Huang L, Jin Q, Liu PN, and Lin N
- Abstract
We employ an on-surface assembly protocol to synthesize a single layer of a two-dimensional conjugated network (Ni3(HITP)2) on a Au(111) surface. The electronic coupling between the π orbital of the diimine ligand and the d orbital of the metal ion renders efficient π-conjugation. Density-functional theory calculations provide evidence of a non-trivial topological gap in the surface-adsorbed single layer. This work demonstrates that single-layer 2D metal-organic frameworks adsorbed on surfaces are a new class of 2D materials that host quantum phases.
- Published
- 2019
- Full Text
- View/download PDF
48. Diverse supramolecular structures self-assembled by a simple aryl chloride on Ag(111) and Cu(111).
- Author
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Shu CH, Zhang SZ, Wang CX, Chen JL, He Y, Shi KJ, and Liu PN
- Abstract
Diverse self-assembled structures were obtained on Cu(111) and Ag(111) surfaces by using a simple and small 4,4''-dichloro-1,1':4',1''-terphenyl molecule. Surprisingly, a complicated supramolecular self-assembled vortex structure, composed of 15 molecules in a large unit, was realized through the collaboration of hydrogen bonding and halogen bonding.
- Published
- 2018
- Full Text
- View/download PDF
49. On-surface reactions of aryl chloride and porphyrin macrocycles via merging two reactive sites into a single precursor.
- Author
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Shu CH, Xie YL, Wang A, Shi KJ, Zhang WF, Li DY, and Liu PN
- Abstract
The reaction of aryl chloride and porphyrin macrocycles, which are merged into a single precursor, has been achieved on Cu(111). Scanning tunneling microscopy analysis of the oligomer products showed that the adjacent porphyrin moieties linked mainly by the phenyl group with the porphyrin macrocycle.
- Published
- 2018
- Full Text
- View/download PDF
50. Radical Cyanotrifluoromethylation of Isocyanides: Step-Economical Access to CF 3 -Containing Nitriles, Amines, and Imines.
- Author
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Chen S, Feng DF, Li DY, and Liu PN
- Abstract
A novel copper-catalyzed radical cyanotrifluoromethylation has been achieved through a multicomponent reaction of isocyanides, Togni's reagent, and trimethylsilyl cyanides, affording trifluoroacetimidoyl nitriles in good yields. This reaction demonstrates a unique feature of merging two valuable functional groups-trifluoromethyl (CF
3 ) and cyan (CN)-onto the same C atom. The transformation proceeds by the initial addition of the CF3 radical to isocyanide and the subsequent intermolecular C-CN formation. The products can be successfully transformed to a series of CF3 -containing amines and imines that may serve in the synthesis of valuable pharmaceuticals and agrochemicals.- Published
- 2018
- Full Text
- View/download PDF
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