In our ongoing study of fungal bioactive natural products, 12 previously undescribed triquinane sesquiterpene glycosides, namely, antrodizonatins A-L (-), and four known compounds (-) have been obtained from the fermentation of the basidiomycete . The structures were established unambiguously via extensive spectroscopic analysis and theoretical calculations of electronic circular dichroism spectra. This is the first report of triquinane sesquiterpene glycosides.
View Article and Find Full Text PDFPhytochemistry
September 2023
Three previously undescribed griseofulvin derivatives, namely pochonichlamydins A-C, one small polyketide, namely pochonichlamydin D, together with nine known compounds, have been isolated from cultures of the fungus Pochonia chlamydosporia. Their structures with absolute configurations were elucidated on the basis of extensive spectrometric methods and single-crystal X-ray diffraction. Dechlorogriseofulvin and griseofulvin exhibited inhibitory activities against Candida albicans at the concentration of 100 μM, with inhibition rates of 69.
View Article and Find Full Text PDFObjective: To analyze the difference in clinical efficacy of minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) under Quadrant channel system combined with microscope and percutaneous pedicle screw in the treatment of degenerative lumbar spondylolisthesis.
Methods: A total of 114 patients with single-segment degenerative lumbar spondylolisthesis from June 2015 to February 2019, were divided into three groups according to the surgical methods, such as the MIS-TLIF under the microscope surgery group ( microscope group), MIS-TLIF combined with percutaneous pedicle screw technique surgery group(percutaneous group) and posterior lumbar interbody fusion surgery group (open group). In the microscope group, there were 12 males and 26 females, aged from 42 to 83 years with an average of (63.
Plasmon resonance energy transfer (PRET) in hybrid plasmonic-molecular systems has a broad range of applications from catalysis to analytical/biochemical/biophysical imaging and sensing. Herein, we experimentally and theoretically probed the influence of the distance () between the plasmonic nanoparticle and the conjugated molecules on the PRET efficiency (η) using two PRET systems, which involved tetramethylrhodamine (TAMRA) or Cy3 molecules as acceptors and single spherical gold nanoparticles (AuNPs) as donors. The double-stranded DNA (dsDNA) sequences precisely adjusted within 12.
View Article and Find Full Text PDFNature enzyme-based immunoassays have been widely used in fundamental scientific research and clinical diagnosis. However, the limitations of natural enzyme, such as the low physical/chemical stability or susceptibility to protein denaturation, greatly restrained its applications. In this article, we reported a new enzyme-free SERS immunoassay by utilizing plasmonic CuS Se nanoparticles (NPs) as nanocatalyst to catalyze the click chemistry between the azido and alkynyl substrate which is used as the SERS signal reporter.
View Article and Find Full Text PDFNonstoichiometric copper chalcogenides with heavy copper vacancies can be used as an effective photo-activated catalyst for the Huisgen [3+2] cycloaddition reaction as Cu(i) can be released corresponding to holes (Cu-defects) under light irradiation. These strategies expand new possibilities for carrying out prototypical click chemistry in the presence of functional groups.
View Article and Find Full Text PDFPlasmonic resonance energy transfer (PRET), which occurs between the plasmonic nanoparticles and organic dyes, has significant potential in target sensing chemistry owing to its sensitivity at the single nanoparticle level. In this contribution, by using AuNPs, which has localized surface plasmonic resonance light scattering (LSPR-LS) around 550 nm, as the donor of PRET, a general sensitive detecting strategy of ions were developed. Targets can specifically react with a ring-close structured rhodamine spirolactam, which was prepared from rhodamines in the presence of different primary amine wherein the option of the primary amine is up to the targets, forming ring-open structured rhodamine spirolactam with the strong absorption around 550 nm.
View Article and Find Full Text PDFEarly detection of cancer is helpful for the control and prevention of diseases. Due to the low content of cancer biomarkers in the early disease phases, however, an ultrasensitive and selective method is critical. In this contribution, an ultrasensitive surface-enhanced Raman scattering (SERS) immunoassay is newly developed with the principle of introducing a common enzyme-induced deposition (EID) reaction to coat a silver layer on the surface of gold nanoparticles and to form a core-shell nanostructure of Au@Ag.
View Article and Find Full Text PDFUnderstanding the photoinduced electron transfer (PET) mechanism is vital to improving the photoelectric conversion efficiency for solar energy materials and photosensitization systems. Herein, we visually demonstrate the PET process by real-time monitoring the photoinduced chemical transformation of p-aminothiophenol (p-ATP), an important SERS signal molecule, to 4,4'-dimercaptoazobenzene on single silver nanoparticles (AgNPs) with a localized surface plasmon resonance (LSPR) spectroscopy coupled dark-field microscopy. The bidirectional LSPR scattering spectral shifts bathochromically at first and hypsochromically then, which are caused by the electron transfer delay of p-ATP, disclose the PET path from p-ATP to O through AgNPs during the reaction, and enable us to digitalize the corresponding electron loss and gain on the surface of AgNP at different time periods.
View Article and Find Full Text PDFSurface functionalization is an essential pre requisite for wide and specific applications of nanoparticles such as photoluminescent (PL) carbon quantum dots (CQDs), but it remains a major challenge. In this report, alkynylated CQDs, prepared from carboxyl-rich CQDs through amidation with propargylamine in the presence of 1,1'-carbonyldiimidazole, were modified efficiently with azido molecular beacon DNA through a copper(I)-catalyzed alkyne-azide cycloaddition reaction (CuAAC). As a proof-of-concept, the DNA-modified CQDs are then bonded with gold nanoparticles (AuNPs, 5 nm) through a gold-sulfur bond.
View Article and Find Full Text PDFResonance energy transfer (RET) processes have wide applications; these processes involve a unidirectional energy transfer from a particular donor to a particular acceptor. Here, we report a plasmonic resonance energy transfer (PRET), which occurs from the surface of gold nanoparticles to fluorescent organic dyes, and coexists with a nanometal surface energy transfer (NSET) that operates in the reverse direction. The coexistence of both PRET and NSET in opposite directions means that the roles of both donor and acceptor can be interchanged, which could be identified by using spectrofluorometric measurements and light scattering dark field microscopic imaging.
View Article and Find Full Text PDFThe plasmon-induced light concentration (PILC) effect, which has been supposed to be responsible for lots of linear and nonlinear enhanced optical signals such as Raman and high-harmonic generation, is hard to directly observe. Herein, we developed a scattered light based composite-field microscopy imaging (iCFM) system by coupling the oblique and vertical illumination modes, which were adopted in dark- and bright-field microscopy imaging systems, respectively, and through which iCFM system monochromatic background (MCB) images are available, to directly observe the PILC effect in far-field scattering microscopy imaging. Owing to the PILC effect, the scattering signal gain of plasmonic nanoparticles was found to be larger than that of the background, and the imaging visibility of plasmonic nanoparticles was improved by 2.
View Article and Find Full Text PDFObjective: To systematically review the effectiveness of minimally invasive total hip arthroplasty (MIS-THA) versus traditional total hip arthroplasty (THA) in patients with hip diseases.
Methods: Through a method of combining Free words and keywords,we searched databases including PubMed,The Cochrane Library, EMbase,Web of Science, CBM , CNKI and Wanfang Data for randomized controlled trials (RCTs) on the comparison between MIS-THA and THA for hip disease from inception to June, 2014. Two reviewers independently screened literatures according to the inclusion and exclusion criteria, extracted data and assessed the quality of the included studies according to the "bias risk assessment" tool recommended by Cochrane Handbook 5.
Chem Commun (Camb)
February 2016
Photoluminescent carbon dots (CDs), hydrothermally prepared using tannic acid (TA), show visual aggregation induced emission enhancement (AIEE) properties at 455 nm when excited at 350 nm owing to the rotational hindering of the surface groups on CDs such as aromatic rings and phenolic hydroxyl ones, causing exponential decay between the ratio of the photoluminescence intensity in organic solvents to that in water and the permittivity of the solvent, and thus dazzling emissions of the CDs in the presence of solvents with small permittivity, tetrahydrofuran (THF), for instance, could be visually observed.
View Article and Find Full Text PDFFluorescence resonance energy transfer (FRET), which occurs between two luminescent chromophores, can greatly improve the selectivity and sensitivity of a fluorescent assay when a ratiometric signaling with the fluorescence enhancement of the acceptor at the expense of the donor is adopted. In this study, a fluorescence ratiometric detection (FRD) of riboflavin (RF) has been made based on FRET, as the strong overlap occurred between the emission spectrum of graphitic carbon nitride (g-C3N4) and absorption spectrum of RF, in which g-C3N4 acts as the energy donor and RF as the energy acceptor. With increasing concentration of RF, the fluorescence intensity of g-C3N4 emission at 444 nm decreased and the fluorescence peak at 523 nm for RF increased regularly, making the fluorescence intensity ratio of 523 nm to 444 nm linearly dependent on the concentration of RF in the range from 0.
View Article and Find Full Text PDFInsight into the nature of metal-sulfur bond, a meaningful one in life science, interface chemistry and organometallic chemistry, is interesting but challenging. By utilizing the localized surface plasmon resonance properties of silver nanoparticles, herein we visually identified the photosensitivity of silver-dithiocarbamate (Ag-DTC) bond by using dark field microscopic imaging (iDFM) technique at single nanoparticle level. It was found that the breakage of Ag-DTC bond could be accelerated effectively by light irradiation, followed by a pH-dependent horizontal or vertical degradation of the DTC molecules, in which an indispensable preoxidation process of the silver was at first disclosed.
View Article and Find Full Text PDFFull understanding and easy construction of specific biosensing principles is necessary for disease diagnostics and therapeutics in the hope of creating new types of biosensors. Herein, we developed a new conceptual nanobiosensing platform by coupling nanometal surface energy transfer (NSET) and photo-induced electron transfer (PET) with polydopamine-embedded Cu(2-x)Se nanoparticles (Cu(2-x)SeNPs@pDA) and DNA-conjugated fluorescent organic dyes. The new prepared Cu(2-x)SeNPs@pDA has intense and broad localized surface plasmon resonance (LSPR) absorption over UV to near infrared (NIR) wavelengths, with different affinities toward ssDNA versus dsDNA.
View Article and Find Full Text PDFPretreatment of nerve allografts by exposure to irradiation or green tea polyphenols can eliminate neuroimmunogenicity, inhibit early immunological rejection, encourage nerve regeneration and functional recovery, improve tissue preservation, and minimize postoperative infection. In the present study, we investigate which intervention achieves better results. We produced a 1.
View Article and Find Full Text PDFCopper chalcogenide nanocrystals (CuCNCs) as a type of semiconductor that can also act as efficient catalysts are rarely reported. Herein, we study water-soluble size-controlled Cu(2-x)Se nanocrystals (NCs), which are copper deficient and could be prepared by a redox reaction with the assistance of surfactants. We found them to have strong near-infrared localized surface plasmon resonance (LSPR) properties originating from the holes in the valence band, and also catalytic activity of more than a 500-fold enhancement of chemiluminescence (CL) in a luminol-H2O2 system.
View Article and Find Full Text PDFObjective: To investigate characteristics of treating dislocation and fracture of sacroiliac joint through anterior and posterior approaches.
Methods: Between January 2006 and September 2012, 39 patients with dislocations and fractures of sacroiliac joint were treated with operation. There were 28 males and 11 females, aged 12 to 64 (mean, 41.
A general quantitative pH sensor for environmental and intracellular applications was developed by the facile hydrothermal preparation of dicyandiamide (DCD) N-doped high quantum yield (QY) graphene quantum dots (GQDs) using citric acid (CA) as the carbon source. The obtained N-doped GQDs have excellent photoluminesence (PL) properties with a relatively high QY of 36.5%, suggesting that N-doped chemistry could promote the QY of carbon nanomaterials.
View Article and Find Full Text PDFHighly PL carbon quantum dots (CQDs) were successfully prepared from C60 by introducing CTAB and H2O2 in aqueous NaOH under hydrothermal conditions. The CQDs displayed a nanoparticle aggregation-induced emission enhancement (NP-AIEE).
View Article and Find Full Text PDFNitrogen-doped carbon dots (CDs) have attracted great interest due to their extraordinary properties, especially their enhanced emission efficiency, and thus a facile synthesis of nitrogen-doped CDs with high emission efficiency is critical for practical applications. To improve the emission efficiency of CDs, herein we employed Bombyx mori silk, which has high nitrogen content, as a raw material to prepare photoluminescent nitrogen-doped carbon dots through one-pot hydrothermal synthesis, and found that the as-prepared CDs have a photoluminescence (PL) quantum yield of 13.9%, and display amphoteric properties depending on the pH, are highly photostable, have low toxicity and are suitable for bioimaging.
View Article and Find Full Text PDFAngiotensin-converting enzyme inhibitors are widely prescribed to regulate blood pressure. High doses of orally administered perindopril have previously been shown to improve fracture healing in a mouse femur fracture model. In this study, perindopril was administered directly to the fracture area with the goal of stimulating fracture repair.
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