Publications by authors named "Haifeng Zheng"

RNA performs a remarkable range of functions, such as RNA processing, chromosome maintenance and dosage compensation. Technologies that robustly and specifically image RNA in its native state are highly desirable, as these technologies can help researchers clarify the localization and functionality of diverse RNAs. Here, we describe the development of a sequence-activated fluorescent RNA (SaFR) technique.

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Background: This study aims to investigate the early kinetics of interleukin 6 (IL-6), procalcitonin (PCT), and C-reactive protein (CRP) on initial antibiotic efficacy in hematological disorder patients with febrile neutropenia (FN).

Methods: A total of 40 patients with 43 episodes of FN were enrolled and divided into initial antibiotic effective group (IAE group, n = 24) and initial antibiotic ineffective group (IAI group, n = 19). The levels of IL-6, PCT, and CRP before antibacterial treatment (T0), and 12 h (T1), 24 h (T2), 48 h (T3), and 72 h (T4) post-antibacterial treatment were determined, respectively.

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Phosphine-ligated transition metal complexes play a pivotal role in modern catalysis, but our understanding of the impact of ligand counts on the catalysis performance of the metal center is limited. Here we report the synthesis of a low-coordinate mono(phosphine)-Rh catalyst on a metal-organic layer (MOL), P-MOL • Rh, and its applications in the hydrogenation of mono-, di-, and tri-substituted alkenes as well as aryl nitriles with turnover numbers (TONs) of up to 390000. Mechanistic investigations and density functional theory calculations revealed the lowering of reaction energy barriers by the low steric hindrance of site-isolated mono(phosphine)-Rh sites on the MOL to provide superior catalytic activity over homogeneous Rh catalysts.

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Phytosterols are vital structural and regulatory components in plants. Zea mays produces a series of phytosterols that are specific to corn. However, the underline biosynthetic mechanism remains elusive.

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Article Synopsis
  • * A total of 310 SSNHL patients were compared to 154 healthy individuals, revealing significantly lower levels of vitamin D, A (in women), and E (in men) in those with SSNHL.
  • * The findings suggest that lower levels of these vitamins could be associated with the development of SSNHL, potentially indicating a role in its pathogenesis.
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Herein, we report the synthesis of a bifunctional photocatalyst, Zr-OTf-EY, through sequential modifications of metal cluster nodes in a metal-organic layer (MOL). With eosin Y and strong Lewis acids on the nodes, Zr-OTf-EY catalyzes cross-coupling reactions between various C-H compounds and electron-deficient alkenes or azodicarboxylate to afford C-C and C-N coupling products, with turnover numbers of up to 1980. In Zr-OTf-EY-catalyzed reactions, Lewis acid sites bind the alkenes or azodicarboxylate to increase their local concentrations and electron deficiency for enhanced radical additions, while EY is stabilized by site isolation on the MOL to afford a long-lived catalyst for hydrogen atom transfer.

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New chiral and achiral dyes were synthesized by using clean, highly efficient Diels-Alder 'click' reactions. We prepared pure endo- and exo- stereoisomers and blue-light-emitting single crystal of an exo-isomer. H NMR spectroscopy and single-crystal X-ray diffraction reveal the precise spatial configurations of endo- and exo-dye stereoisomers.

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The cell types and conductance that contribute to normal cardiac functions remain under investigation. We used mice that express an enhanced green fluorescent protein (eGFP)-histone 2B fusion protein driven off the cell-specific endogenous promoter for Pdgfra to investigate the distribution and functional role of PDGFRα cells in the heart. Cardiac PDGFRα cells were widely distributed within the endomysium of atria, ventricle, and sino-atrial node (SAN) tissues.

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Highly efficient perovskite optoelectronics (POEs) have been limited by nonradiative recombination. We report a strategy to inhibit the nonradiative recombination of 2D triphenylamine polymers in the hole transport layer (HTL) via introducing electron-donating groups to enhance the conjugation effect and electron cloud density. The conjugated systems with electron-donating groups present smaller energy level oscillation compared to the ones with electron-absorbing groups, as confirmed by nonadiabatic molecular dynamics (NAMD) calculation.

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Metal-organic layers (MOLs), a monolayered version of metal-organic frameworks (MOFs), have recently emerged as a novel two-dimensional molecular material platform to design multifunctional catalysts. MOLs inherit the intrinsic molecular tunability of MOFs and yet have more accessible and modifiable building blocks. Here we report molecular engineering of six MOLs via modulated solvothermal synthesis between HfCl and three photosensitizing ligands followed by postsynthetic modification with two carboxylate-containing cobaloximes for tandem and synergistic photocatalysis.

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Aberrant splicing of precursor messenger RNA (pre-mRNA) can generate abnormal transcripts, and most of the human diseases have been shown to associate with abnormal splicing of pre-mRNA. Conventional methods require sample lysis and thus cannot be used for monitoring pre-mRNA splicing in real time. This chapter guides how to develop an intron-retained bioluminescence (BL) reporter, which simulates the splicing process of pre-mRNA in vitro and in vivo noninvasively.

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Herein, we report the synthesis of a metal-organic layer, Hf-Ru-Au, containing Ru(bipyridine)-type photosensitizers and (phosphine)-AuCl catalysts for photoredox Au-catalyzed cross-coupling of allenoates, alkenes, or alkynes with aryldiazonium salts to afford furanone, tetrahydrofuran, or aryl alkyne derivatives, respectively. Site isolation of (phosphine)-AuCl complexes in Hf-Ru-Au prevents Au catalyst deactivation via ligand redistribution, Au(I) disproportionation, and aryl-phosphine reductive elimination, while the proximity between the Ru photosensitizers and Au catalysts enhances catalytic efficiency, with 14-200 times higher activity over those of the homogeneous controls in the cross-coupling reactions.

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Background: The effects of graft thickness on tympanoplasty is uncertain.

Objective: To compare the results of endoscopic tympanoplasty using different thicknesses of autologous tissues.

Methods: This retrospective analysis included 186 patients who received type I tympanoplasty, divided into three main groups based of grafting material: perichondrium (A), cartilage-perichondrium (B), or cartilage-perichondrium plus additional perichondrium (C).

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Correction for 'Dynamic visualization of mRNA splicing variants with a transactivating reporter' by Si Chen , , 2021, DOI: 10.1039/d1cc02439f.

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Dynamic changes in intron sequences, with their loss and gain, are poorly detected due to the limited methods for the non-invasive monitoring of the pre-mRNA splicing process. Here, we describe the design of a two-step transcriptional activation (TSTA) reporter for the real-time imaging of the splicing process in living subjects. By taking advantage of the strong transactivating properties of the GAL4VP16 fusion protein, which can target upstream activation sequence (UAS) elements to boost subsequent firefly luciferase reporter gene expression, we successfully and consistently detected the dynamic pre-mRNA splicing activity in response to exogenous splicing modulators in living cells and animals.

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An oxocarbenium-olefin cross metathesis occurs during Brønsted acid catalyzed reactions of 1-isochromene acetals with vinyl diazo compounds. Formally a carbonyl-alkene [2 + 2]-cyclization between isobenzopyrylium ions and the vinyl group of vinyl diazoesters, the retro-[2 + 2] cycloaddition produces a tethered alkene and a vinyl diazonium ion that, upon loss of dinitrogen, undergoes a highly selective carbocationic cascade rearrangements to diverse products whose formation is controlled by reactant substituents. Polysubstituted benzobicyclo[3.

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1,2,3-Triazine 1-oxides are formed by nitrosyl addition from -butyl nitrite to the vinylogous position of vinyl diazo compounds. This transformation, which is a formal intermolecular [5 + 1] cycloaddition, occurs under mild conditions, with high functional group tolerance and regioselectivity, and can be employed for late-stage functionalization. Upon heating at refluxing chlorobenzene temperature, these triazine--oxides undergo dinitrogen extrusion to form isoxazoles in very high yields.

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Brønsted acid catalyzed formal [4 + 4]-, [4 + 3]-, and [4 + 2]-cycloadditions of donor-acceptor cyclobutenes, cyclopropenes, and siloxyalkynes with benzopyrylium ions are reported. [4 + 2]-cyclization/deMayo-type ring-extension cascade processes produce highly functionalized benzocyclooctatrienes, benzocycloheptatrienes, and 2-naphthols in good to excellent yields and selectivities. Moreover, the optical purity of reactant donor-acceptor cyclobutenes is fully retained during the cascade.

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A general catalytic methodology for the synthesis of pyrazolines from α-diazo compounds and conjugated alkenes is reported. The direct hydrogen atom transfer (HAT) process of α-diazo compounds promoted by the tert-butylperoxy radical generates electrophilic diazomethyl radicals, thereby reversing the reactivity of the carbon atom attached with the diazo group. The regiocontrolled addition of diazomethyl radicals to carbon-carbon double bonds followed by intramolecular ring closure on the terminal diazo nitrogen and tautomerization affords a diverse set of pyrazolines in good yields with excellent regioselectivity.

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Two types of voltage-dependent inward currents were evoked by depolarization in murine antral smooth muscle cells (SMCs) bathed in Ca-containing physiological solution: high-voltage-activated (HVA) and low-voltage-activated (LVA) inward currents. We examined whether the LVA current was due to: ) T-type Ca channels, ) Ca-activated Clchannels, ) nonselective cation channels (NSCC), or ) voltage-dependent K channels. Replacement of external Ca (2 mM) with equimolar Ba increased the amplitude of the HVA current but blocked the LVA current.

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The decomposition of litter carbon (C) fraction is a major determinant of soil organic matter pool and nutrient cycling. However, knowledge of litter chemical traits regulate C fractions release is still relatively limited. A litterbag experiment was conducted using six plant functional litter types at two vegetation type (coniferous forest and alpine shrubland) in a treeline ecotone.

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Pyroptotic cell death is a phenomenon that runs through all life activities and plays an important role in physiological and pathological processes of the body's metabolism. It is of big biological significance to understand the phenomenon and nature of cell pyroptosis. In the process of cell pyroptosis, the pore-forming effector gasdermin D (GSDMD) is cleaved to form oligomers, which are inserted into the cell membrane, causing rapid cell death.

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The design and characterization of the heteronuclear group 14 C[triple bond, length as m-dash]E (E = Si, Ge, Sn, Pb) triple bonds have attracted intensive interest in the past few decades. In the current work, utilizing the advantages of N-heterocyclic carbenes (NHCs) and Lewis acid-base pair strategy, we theoretically designed a new class of compounds III-1, i.e.

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