Sinomenine Ameliorated Microglial Activation and Neuropathic Pain After Chronic Constriction Injury Via TGF-β1/ALK5/Smad3 Signalling Pathway.

Sinomenine (SIN), a bioactive isoquinoline alkaloid extracted from the roots and stems of Sinomenium acutum, is efficacious against various chronic pain conditions. Inhibition of microglial activation at the spinal level contributes to the analgesic effects of SIN. Microglial activation in the spinal dorsal horn is key to sensitising neuropathic pain.

Position Checking-Based Sampling Approach Combined with Attraction Point Local Optimization for Safe Flight of UAVs.

Trading off the allocation of limited computational resources between front-end path generation and back-end trajectory optimization plays a key role in improving the efficiency of unmanned aerial vehicle (UAV) motion planning. In this paper, a sampling-based kinodynamic planning method that can reduce the computational cost as well as the risks of UAV flight is proposed. Firstly, an initial trajectory connecting the start and end points without considering obstacles is generated.

Association of preoperative frailty with the risk of postoperative delirium in older patients undergoing hip fracture surgery: a prospective cohort study.

Objective: This study aimed to explore the correlation between preoperative frailty and the risk of postoperative delirium (POD) in older patients undergoing hip fracture surgery.

Methods: In total, 148 patients with hip fractures who were admitted to Tsinghua Changgung Hospital (Beijing, China) between January 2022 and January 2023 were involved in this study. Preoperative frailty scales were assessed, of which the CAM scale was postoperatively administered every morning and evening on days 1, 2, 3, 5, and 7.

Noninvasive assessment of breast cancer molecular subtypes on multiparametric MRI using convolutional neural network with transfer learning.

Background: To evaluate the performances of multiparametric MRI-based convolutional neural networks (CNNs) for the preoperative assessment of breast cancer molecular subtypes.

Methods: A total of 136 patients with 136 pathologically confirmed invasive breast cancers were randomly divided into training, validation, and testing sets in this retrospective study. The CNN models were established based on contrast-enhanced T -weighted imaging (T C), Apparent diffusion coefficient (ADC), and T -weighted imaging (T W) using the training and validation sets.

Combined diagnosis of multiparametric MRI-based deep learning models facilitates differentiating triple-negative breast cancer from fibroadenoma magnetic resonance BI-RADS 4 lesions.

Purpose: To investigate the value of the combined diagnosis of multiparametric MRI-based deep learning models to differentiate triple-negative breast cancer (TNBC) from fibroadenoma magnetic resonance Breast Imaging-Reporting and Data System category 4 (BI-RADS 4) lesions and to evaluate whether the combined diagnosis of these models could improve the diagnostic performance of radiologists.

Methods: A total of 319 female patients with 319 pathologically confirmed BI-RADS 4 lesions were randomly divided into training, validation, and testing sets in this retrospective study. The three models were established based on contrast-enhanced T1-weighted imaging, diffusion-weighted imaging, and T2-weighted imaging using the training and validation sets.

A Magnetic Resonance Angiography-Based Study Comparing Machine Learning and Clinical Evaluation: Screening Intracranial Regions Associated with the Hemorrhagic Stroke of Adult Moyamoya Disease.

Objectives: Moyamoya disease patients with hemorrhagic stroke usually have a poor prognosis. This study aimed to determine whether hemorrhagic moyamoya disease could be distinguished from MRA images using transfer deep learning and to screen potential regions that contain rich distinguishing information from MRA images in moyamoya disease.

Materials And Methods: A total of 116 adult patients with bilateral moyamoya diseases suffering from hemorrhagic or ischemia complications were retrospectively screened.

Investigation of the C-N Bond-Forming Step in a Photoinduced, Copper-Catalyzed Enantioconvergent N-Alkylation: Characterization and Application of a Stabilized Organic Radical as a Mechanistic Probe.

Whereas photoinduced, copper-catalyzed couplings of nitrogen nucleophiles with alkyl electrophiles have recently been shown to provide an attractive approach to achieving a variety of enantioselective C-N bond constructions, mechanistic studies of these transformations have lagged the advances in reaction development. Herein we provide mechanistic insight into a previously reported photoinduced, copper-catalyzed enantioconvergent C-N coupling of a carbazole nucleophile with a racemic tertiary α-haloamide electrophile. Building on the isolation of a copper(II) model complex whose EPR parameters serve as a guide, we independently synthesize two key intermediates in the proposed catalytic cycle, a copper(II) metalloradical (L*Cu(carb')) (L* = a monodentate chiral phosphine ligand; carb' = a carbazolide ligand), as well as a tertiary α-amide organic radical (R·); the generation and characterization of R· was guided by DFT calculations, which suggested that it would be stable to homocoupling.

Apparent Diffusion Coefficient-Based Convolutional Neural Network Model Can Be Better Than Sole Diffusion-Weighted Magnetic Resonance Imaging to Improve the Differentiation of Invasive Breast Cancer From Breast Ductal Carcinoma .

Background And Purpose: Breast ductal carcinoma (DCIS) has no metastatic potential, and has better clinical outcomes compared with invasive breast cancer (IBC). Convolutional neural networks (CNNs) can adaptively extract features and may achieve higher efficiency in apparent diffusion coefficient (ADC)-based tumor invasion assessment. This study aimed to determine the feasibility of constructing an ADC-based CNN model to discriminate DCIS from IBC.

Cerium(iv) complexes with guanidinate ligands: intense colors and anomalous electronic structures.

A series of cerium(iv) mixed-ligand guanidinate-amide complexes, {[(MeSi)NC(N Pr)] Ce[N(SiMe)] } ( = 0-3), was prepared by chemical oxidation of the corresponding cerium(iii) complexes, where = 1 and 2 represent novel complexes. The Ce(iv) complexes exhibited a range of intense colors, including red, black, cyan, and green. Notably, increasing the number of the guanidinate ligands from zero to three resulted in significant redshift of the absorption bands from 503 nm (2.

Regio- and Stereoselective Photoredox-Catalyzed Atom Transfer Radical Addition of Thiosulfonates to Aryl Alkynes.

Despite extensive investigations, altering the regioselectivity of atom transfer radical addition (ATRA) to alkynes remains a highly desirable yet unachieved challenge. Guided by computational predictions, thiosulfonates were found herein as a tunable radical precursor for thiyl radicals instead of well-recognized sulfonyl radicals. Merging such a finding with ATRA to phenylacetylenes leads to a highly regio- and stereoselective approach to ()-β-arylsulfonylvinyl sulfides.

Synergistic N-Heterocyclic Carbene/Palladium-Catalyzed Umpolung 1,4-Addition of Aryl Iodides to Enals.

An umpolung 1,4-addition of aryl iodides to enals promoted by cooperative (terpy)Pd/NHC catalysis was developed that generates various bioactive β,β-diaryl propanoate derivatives. This system is not only the first reported palladium-catalyzed arylation of NHC-bound homoenolates but also expands the scope of NHC-induced umpolung transformations. A diverse array of functional groups such as esters, nitriles, alcohols, and heterocycles are tolerated under the mild conditions.

Mechanistic Investigation of Enantioconvergent Kumada Reactions of Racemic α-Bromoketones Catalyzed by a Nickel/Bis(oxazoline) Complex.

In recent years, a wide array of methods for achieving nickel-catalyzed substitution reactions of alkyl electrophiles by organometallic nucleophiles, including enantioconvergent processes, have been described; however, experiment-focused mechanistic studies of such couplings have been comparatively scarce. The most detailed mechanistic investigations to date have examined catalysts that bear tridentate ligands and, with one exception, processes that are not enantioselective; studies of catalysts based on bidentate ligands could be anticipated to be more challenging, due to difficulty in isolating proposed intermediates as a result of instability arising from coordinative unsaturation. In this investigation, we explore the mechanism of enantioconvergent Kumada reactions of racemic α-bromoketones catalyzed by a nickel complex that bears a bidentate chiral bis(oxazoline) ligand.

Catalytic enantioconvergent coupling of secondary and tertiary electrophiles with olefins.

Carbon-carbon bonds, including those between sp-hybridized carbon atoms (alkyl-alkyl bonds), typically comprise much of the framework of organic molecules. In the case of sp-hybridized carbon, the carbon can be stereogenic and the particular stereochemistry can have implications for structure and function. As a consequence, the development of methods that simultaneously construct alkyl-alkyl bonds and control stereochemistry is important, although challenging.

Understanding and Controlling the Emission Brightness and Color of Molecular Cerium Luminophores.

Molecular cerium complexes are a new class of tunable and energy-efficient visible- and UV-luminophores. Understanding and controlling the emission brightness and color are important for tailoring them for new and specialized applications. Herein, we describe the experimental and computational analyses for series of tris(guanidinate) (1-8, Ce{(RN)C(N Pr)}, R = alkyl, silyl, or phenyl groups), guanidinate-amide [GA, A = N(SiMe), G = (MeSi)NC(N Pr)], and guanidinate-aryloxide (GOAr, OAr = 2,6-di- tert-butylphenoxide) cerium(III) complexes to understand and develop predictive capabilities for their optical properties.

The Hexachlorocerate(III) Anion: A Potent, Benchtop Stable, and Readily Available Ultraviolet A Photosensitizer for Aryl Chlorides.

The hexachlorocerate(III) anion, [CeCl], was found to be a potent photoreductant in acetonitrile solution with an estimated excited-state reduction potential of -3.45 V versus CpFe. Despite a short lifetime of 22.

Reactions of a cerium(iii) amide with heteroallenes: insertion, silyl-migration and de-insertion.

Reactions of Ce[N(SiMe3)Ph(F)]3 (-Ph(F) = pentafluorophenyl) toward small molecules of the type E1[double bond, length as m-dash]C[double bond, length as m-dash]E2 (E1, E2 = O, S, NR), including carbon disulfide, carbodiimide, carbon dioxide, isocyanate and isothiocyanate are reported, resulting in distinct products, including cerium(iii) dithiocarbamate, cerium(iii) guanidinate, isocyanates and unsymmetric carbodiimides. These reactions were rationalized as three consecutive stages of the same reaction pathway: insertion, silyl-migration and de-insertion.

Cerium(III) and Uranium(IV) Complexes of the 2-Fluorophenyl Trimethylsilyl Amide Ligand: C-F → Ln/An Interactions that Modulate the Coordination Spheres of f-Block Elements.

2-fluorophenyl trimethylsilyl amide, N(SiMe3)(C6H4F)(-) was shown to engage in stronger C-F → Ce(III) interactions than pentafluorophenyl trimethylsilyl amide, N(SiMe3)(C6F5)(-), through a comparative study of the Ce(III) model complexes Ce[N(SiMe3)(C6H4F)]3 (1-F1) and Ce[N(SiMe3)(C6F5)]3 (1-F5). The presence of multiple C-F → U(IV) interactions led to complexes 2-X (X = Cl, C≡CPh, OMe) with threefold geometries, featuring a trigonal pyramidal UN3Cl core in the solid-state structures. Density functional theory calculations were applied to 2-Cl to investigate the strength of the C-F → U(IV) interactions and the influence of such interactions on resulting geometries.

Cerium Photosensitizers: Structure-Function Relationships and Applications in Photocatalytic Aryl Coupling Reactions.

Two complete mixed-ligand series of luminescent Ce(III) complexes with the general formulas [(Me3Si)2NC(N(i)Pr)2]xCe(III)[N(SiMe3)2]3-x (x = 0, 1-N; x = 1, 2-N, x = 2, 3-N; x = 3, 4) and [(Me3Si)2NC(N(i)Pr)2]xCe(III)(OAr)3-x (x = 0, 1-OAr; x = 1, 2-OAr, x = 2, 3-OAr; x = 3, 4) were developed, featuring photoluminescence quantum yields up to 0.81(2) and lifetimes to 117(1) ns. Although the 4f → 5d absorptive transitions for these complexes were all found at ca.

C-F→Ln/An interactions in synthetic f-element chemistry.

The coordination of C-F moieties to electrophilic metal cations has been increasingly recognized in f-element chemistry over the last two decades. These C-F→Ln/An interactions are readily identified in the solid state and can persist in solution. The binding energies of C-F→Ln/An interactions lead to their ready displacement to expose metal centers to substrates, which is implicated in cationic polymerization catalysts.

Luminescent Ce(III) Complexes as Stoichiometric and Catalytic Photoreductants for Halogen Atom Abstraction Reactions.

Luminescent Ce(III) complexes, Ce[N(SiMe3)2]3 (1) and [(Me3Si)2NC(RN)2]Ce[N(SiMe3)2]2 (R = (i)Pr, 1-(i)Pr; R = Cy, 1-Cy), with C(3v) and C(2v) solution symmetries display absorptive 4f → 5d electronic transitions in the visible region. Emission bands are observed at 553, 518, and 523 nm for 1, 1-(i)Pr, and 1-Cy with lifetimes of 24, 67, and 61 ns, respectively. Time-dependent density functional theory (TD-DFT) studies on 1 and 1-(i)Pr revealed the (2)A1 excited states corresponded to singly occupied 5d(z(2)) orbitals.

Investigation of Uranium Tris(imido) Complexes: Synthesis, Characterization, and Reduction Chemistry of [U(NDIPP)3(thf)3].

Addition of KC8 to trivalent [UI3(thf)4] in the presence of three equivalents of 2,6-diisopropylphenylazide (N3DIPP) results in the formation of the hexavalent uranium tris(imido) complex [U(NDIPP)3(thf)3] (1) through a facile, single-step synthesis. The X-ray crystal structure shows an octahedral complex that adopts a facial orientation of the imido substituents. This structural trend is maintained during the single-electron reduction of 1 to form dimeric [U(NDIPP)3{K(Et2O)}]2 (2).

Anomalous one-electron processes in the chemistry of uranium nitrogen multiple bonds.

Novel reaction pathways are illustrated in the synthesis of uranium(IV), uranium(V), and uranium(VI) monoimido complexes. In contrast to the straightforward preparation of U(V)(═NSiMe3)[N(SiMe3)2]3 (1), the synthesis of a uranium(V) tritylimido complex, U(V)(═NCPh3)[N(SiMe3)2]3 (4), from U(III)[N(SiMe3)2]3 and Ph3CN3 was found to proceed through multiple one-electron steps. Whereas the oxidation of 1 with copper(II) salts produced the uranium(VI) monoimido complexes U(VI)(═NSiMe3)X[N(SiMe3)2]3 (X = Cl, Br), the reaction of 4 with CuBr2 undergoes sterically induced reduction to form the uranium(VI) monoimido complex U(VI)(═NCPh3)Br2[N(SiMe3)2]2, demonstrating a striking difference in reactivity based on imido substituent.

A new class of organocatalysts: sulfenate anions.

Sulfenate anions are known to act as highly reactive species in the organic arena. Now they premiere as organocatalysts. Proof of concept is offered by the sulfoxide/sulfenate-catalyzed (1-10 mol%) coupling of benzyl halides in the presence of base to generate trans-stilbenes in good to excellent yields (up to 99%).

Uranyl-oxo coordination directed by non-covalent interactions.

Directed coordination of weakly Lewis acidic K(+) ions to weakly Lewis basic uranyl oxo ligands is accomplished through non-covalent cation-π and cation-F interactions for the first time. Comparison of a family of structurally related diarylamide ligands highlights the role that the cation-π and cation-F interactions play in guiding coordination. Cation binding to uranyl is demonstrated in the solid state and in solution, providing the shortest reported crystallographic uranyl-oxo to potassium distance.

NiXantphos: a deprotonatable ligand for room-temperature palladium-catalyzed cross-couplings of aryl chlorides.

Although the past 15 years have witnessed the development of sterically bulky and electron-rich alkylphosphine ligands for palladium-catalyzed cross-couplings with aryl chlorides, examples of palladium catalysts based on either triarylphosphine or bidentate phosphine ligands for efficient room temperature cross-coupling reactions with unactivated aryl chlorides are rare. Herein we report a palladium catalyst based on NiXantphos, a deprotonatable chelating aryldiphosphine ligand, to oxidatively add unactivated aryl chlorides at room temperature. Surprisingly, comparison of an extensive array of ligands revealed that under the basic reaction conditions the resultant heterobimetallic Pd-NiXantphos catalyst system outperformed all the other mono- and bidentate ligands in a deprotonative cross-coupling process (DCCP) with aryl chlorides.