Publications by authors named "Zhang Chun-Lin"

Herein, we develop a dual catalytic platform for the 1,2- or 1,4-alkylacylation reaction of 1,3-dienes with readily available alkyl halides and aldehydes by merging -heterocyclic carbene catalysis with photoinduced palladium catalysis. A series of β,γ-unsaturated ketones are obtained in good to high yields. Mechanistic studies suggest that this reaction involves a radical process.

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Objective: To investigate the effect of nasal mucosa-derived ectodermal mesenchymal stem cells (NM-EMSCs) on the inflammatory state of rats with chronic rhinosinusitis (CRS) and the underlying therapeutic mechanism.

Methods: NM-EMSCs were isolated and extracted to construct a rat model of CRS. Fifteen Sprague‒Dawley (SD) rats were randomly divided into three groups: CK + NS group rats were injected locally with saline in the nasal mucosa; CRS + NS group rats were injected locally with saline in the nasal mucosa; and CRS + EMSCs group rats were injected locally with NM-EMSCs in the nasal mucosa.

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N-heterocyclic carbene catalysis has been developed as a versatile method for the enantioselective synthesis of complex organic molecules in organic chemistry. Merging of N-heterocyclic carbene catalysis with transition metal catalysis holds the potential to achieve unprecedented transformations with broad substrate scope and excellent stereoselectivity, which are unfeasible with individual catalyst. Thus, this dual catalysis has attracted increasing attention, and numerous elegant dual catalytic systems have been established.

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The progression of osteoarthritis (OA) includes the initial inflammation, subsequent degradation of the extracellular matrix (ECM), and chondrocyte apoptosis. Down syndrome candidate region 1 (DSCR1) is a stress-responsive gene and expresses in varied types of cells, including chondrocytes. Bioinformatics analysis of GSE103416 and GSE104739 datasets showed higher DSCR1 expression in the inflamed cartilage tissues and chondrocytes of OA.

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Herein, a cooperative -heterocyclic carbene- and palladium-catalyzed three-component reaction of alkynes with aldehydes and fluoroalkyl iodides is developed. A series of biologically valuable -incorporated α-substituted enones was obtained in moderate to good yields. This mild catalytic method exhibits exclusive regio- and stereoselectivity, excellent functional group tolerance, and a broad substrate scope including terminal and internal alkynes.

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Article Synopsis
  • * It introduces a novel normal conducting (NC) cavity design that efficiently damps higher-order modes (HOM) by optimizing their lowest frequency and using a beam-line absorber without affecting acceleration performance.
  • * Simulations of a prototype 166.6 MHz HOM-damped cavity show impressive impedance characteristics, achieving approximately 8 MΩ for fundamental mode impedance while maintaining low HOM impedances.
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Axially chiral diaryl ethers are present in numerous natural products and bioactive molecules. However, only few catalytic enantioselective approaches have been established to access diaryl ether atropisomers. Herein, we report the N-heterocyclic carbene-catalyzed enantioselective synthesis of axially chiral diaryl ethers via desymmetrization of prochiral 2-aryloxyisophthalaldehydes with aliphatic alcohols, phenol derivatives, and heteroaromatic amines.

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Cellulose filter paper (CFP) is expected to be an ideal carrier for enzyme immobilization due to its sustainability and biocompatibility. However, the interaction between the carrier and enzyme might change the spatial conformation of the enzyme and its microenvironment, and thus the flexibility of the enzyme molecule or the transport of the substrate to the active site would be hampered. In this work, a two-component system of catechol and tetraethylene pentamine was used to replace dopamine, and a polydopamine-like composite layer was deposited on the surface of CFP to introduce amino groups, which was similar to the self-polymerization-adhesion behavior of dopamine.

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An NHC-catalyzed atroposelective synthesis of axially chiral α-carbolinones from α,β-unsaturated iminoindole derivatives and α-chloroaldehydes was developed. The reaction proceeds through a cascade process including [4 + 2] annulation and then oxidative dehydrogenation with concomitant central-to-axial chirality conversion under mild conditions. The developed method opens a new avenue to efficiently access axially chiral α-carbolinones in moderate to good enantioselectivities.

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Direct synthesis of ketones from aldehydes features high atom- and step-economy. Yet, the coupling of aldehydes with unactivated alkyl C(sp)-H remains challenging. Herein, we develop the synthesis of ketones from aldehydes via alkyl C(sp)-H functionalization under photoredox cooperative NHC/Pd catalysis.

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Ischemic stroke is a highly complex systemic disease characterized by intricate interactions between the brain and gastrointestinal tract. While our current understanding of these interactions primarily stems from experimental models, their relevance to human stroke outcomes is of considerable interest. After stroke, bidirectional communication between the brain and gastrointestinal tract initiates changes in the gastrointestinal microenvironment.

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Acetabular metastasis is a type of metastatic bone cancer, and it mainly metastasizes from cancers such as lung cancer, breast cancer, and renal carcinoma. Acetabular metastasis often causes severe pain, pathological fractures, and hypercalcemia which may seriously affect the quality of life of acetabular metastasis patients. Due to the characteristics of acetabular metastasis, there is no most suitable treatment to address it.

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Osteosarcoma is a malignant tumor that predominantly occurs in children or adolescents under the age of 20 years old. Metastasis and chemotherapy resistance are two problems in the treatment of osteosarcoma, and the lack of definite biomarkers impairs the course of treatment. In recent years, non-coding RNA, as a biomarker of osteosarcoma, has become an area of research focus.

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N-heterocyclic carbene (NHC)-catalyzed enantioselective Mannich-type reactions of the biomass-derived platform compound 5-(chloromethyl)furfural (CMF) with imines were developed. A series of high-value-added chiral amines were afforded in good to high yields with excellent regio- and enantioselectivities. The bifunctional NHC derived from ʟ-pyroglutamic acid efficiently steered the remote addition of the trienolate intermediate to the imine in a highly stereocontrolled manner.

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The incidence of incomplete partition Type I inner ear malformation is very low; therefore, bacterial meningitis caused by this malformation is also rare. Here, we report a case of such a patient. This case is a young female patient, who is 7 years old, began to have recurrent headaches, and after 5 years, also began to have chest and back pain.

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The iminoacylation of alkenes via photoredox N-heterocyclic carbene catalysis is developed with the employment of alkene-tethered α-imino-oxy acids and acyl imidazoles. The corresponding substituted 3,4-dihydro-2-pyrroles were afforded in moderate to good yields with good to high diastereoselectivities in most cases. The reaction involves the 5--trig radical cyclization of an alkene-tethered iminyl radical and the following coupling with a ketyl radical from acyl imidazole under NHC catalysis.

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Diabetic retinopathy (DR) is the leading cause of vision loss in working age population. Intravitreal injection of anti-VEGF antibody is widely used in clinical practice. However, about 27% of patients show poor response to anti-VEGF therapy and about 50% of these patients continue to have macular thickening.

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An N-heterocyclic carbene-catalyzed three-component reaction of ketone, acetylenedicarboxylate, and enal for the synthesis of multisubstituted benzenes has been developed. The key features of this reaction are mild reaction conditions and high efficiency and chemoselectivity. The corresponding pentasubstituted benzenes are obtained in good to high yields.

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Three-component carboacylation of simple alkenes with readily available reagents is challenging. Transition metal-catalysed intermolecular carboacylation works for alkenes with strained ring or directing groups. Herein, we develop a photoredox cooperative N-heterocyclic carbene/Pd-catalysed alkylacylation of simple alkenes with aldehydes and unactivated alkyl halides to provide ketones in good yields.

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Cerebral microbleeds (CMBs) are a disorder of cerebral microvessels that are characterized as small (<10 mm), hypointense, round or ovoid lesions seen on T2*-weighted gradient echo MRI. There is a high prevalence of CMBs in community-dwelling healthy older people. An increasing number of studies have demonstrated the significance of CMBs in stroke, dementia, Parkinson's disease, gait disturbances and late-life depression.

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Accumulating evidence has shown that circular RNA (circRNA) dysregulation is involved in various types of cancer, including osteosarcoma (OS). Nevertheless, the role and mechanism of circRNAs in OS progression and chemoresistance remain elusive. We found that a novel doxorubicin-induced circular RNA, hsa_circ_0004674, screened by whole total transcriptome RNA sequencing in our previous study, was upregulated in OS chemoresistant cell lines and tissues and also connected with patients' poor prognosis.

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Blood-Brain Barrier (BBB) disruption is an important pathophysiological process of acute ischemic stroke (AIS), resulting in devastating malignant brain edema and hemorrhagic transformation. The rapid activation of immune cells plays a critical role in BBB disruption after ischemic stroke. Infiltrating blood-borne immune cells (neutrophils, monocytes, and T lymphocytes) increase BBB permeability, as they cause microvascular disorder and secrete inflammation-associated molecules.

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Diabetic retinopathy (DR) is one of the common complications in diabetic patients. Nowadays, VEGF pathway is subject to extensive research. However, about 27% of the patients have a poor visual outcome, with 50% still having edema after two years' treatment of diabetic macular edema (DME) with ranibizumab.

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Axially chiral biaryl scaffolds are prevalent in natural products, chiral ligands, and organocatalysts. However, N-heterocyclic carbene (NHC) catalyzed de novo construction of an aromatic ring with concomitant axial chirality induction for the synthesis of biaryl atropisomers is far less developed, and the efficient synthesis of axially chiral tetra-ortho-substituted biaryls remains an unsolved problem under NHC catalysis. Reported here is an NHC-catalyzed de novo synthesis of axially chiral benzothiophene/benzofuran-fused biaryls from enals and 2-benzyl-benzothiophene/benzofuran-3-carbaldehydes through a [2+4] annulation, decarboxylation, and oxidative aromatization cascade with central-to-axial chirality conversion.

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Following the well-recognized dynamic kinetic resolution (DKR) of hemiaminals with α-hydrogen under lipase and chiral DMAP catalysis, the unprecedented DKR of hemiaminals without α-hydrogen was developed via N-heterocyclic carbene catalyzed -acylation of 3-hydroxy-3-trifluoromethylbenzosultams. The racemic hemiaminals without α-hydrogen were effectively racemized and differentiated by chiral NHCs under basic conditions. The resulting esters were obtained in high yields with good to high enantioselectivities.

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