A high-performance fluorescent and ratiometric colorimetric detection of Cu in practice.

To monitor Cu efficiently, a kind of D-π-A-π-D conjugated 3,5-di-(2-hydroxyl naphthaldehyde)-iminyl triazole (HNIT) was developed, using triazole as the electron acceptor, 2-hydroxyl naphthaline as the electron donor, and -CN- as the bridging group. The proposed HNIT possessed superior UV-vis and fluorescent spectral property with high molar absorption coefficient of 2.313 × 10 L mol cm and fluorescence quantum yield of 36.

Metabolic fluorine labeling and hotspot imaging of dynamic gut microbiota in mice.

Real-time localization and microbial activity information of indigenous gut microbiota over an extended period of time remains a challenge with existing visualizing methods. Here, we report a metabolic fluorine labeling (MEFLA)-based strategy for monitoring the dynamic gut microbiota via F magnetic resonance imaging (F MRI). In situ labeling of different microbiota subgroups is achieved by using a panel of peptidoglycan-targeting MEFLA probes containing F atoms of different chemical shifts, and subsequent real-time in vivo imaging is accomplished by multiplexed hotspot F MRI with high sensitivity and unlimited penetration.

Combining convolutional neural networks and self-attention for fundus diseases identification.

Early detection of lesions is of great significance for treating fundus diseases. Fundus photography is an effective and convenient screening technique by which common fundus diseases can be detected. In this study, we use color fundus images to distinguish among multiple fundus diseases.

Convenient colorimetric-fluorescent dual-mode recognition of I in agricultural products and visual determination of Hg in drinking beverages using Ag-Pt bimetal quantum dot nanozyme.

Conveniently and efficiently monitoring I and Hg in agricultural products or drinking beverages for the protection of human health is currently a great challenge. With this aim, a Ag-Pt bimetal quantum-dot nanozyme boosted by bioactive folic acid (FA@Ag-Pt QDs) was first developed for multichannel monitoring of I and Hg in this work using a two-step liquid-phase reduction method. Not only did the present FA@Ag-Pt QDs possess superior peroxidase-like activity with Michaelis constant (K) and maximal reaction rate (V) of 0.

Cervical Cell/Clumps Detection in Cytology Images Using Transfer Learning.

Cervical cancer is one of the most common and deadliest cancers among women and poses a serious health risk. Automated screening and diagnosis of cervical cancer will help improve the accuracy of cervical cell screening. In recent years, there have been many studies conducted using deep learning methods for automatic cervical cancer screening and diagnosis.

Augmentation and heterogeneous graph neural network for AAAI2021-COVID-19 fake news detection.

Misinformation has become a frightening specter of society, especially fake news that concerning Covid-19. It massively spreads on the Internet, and then induces misunderstandings of information to the national and global communities during the pandemic. Detecting massive misinformation on the Internet is crucial and challenging because humans have struggled against this phenomenon for a long time.

Redox-Activated Contrast-Enhanced -Weighted Imaging Visualizes Glutathione-Mediated Biotransformation Dynamics in the Liver.

GSH-mediated liver biotransformation is a crucial physiological process demanding efficient research tools. Here, we report a type of amorphous FeMnO nanoparticles (AFMO-ZDS NPs) as redox-activated probes for visualization of the dynamics of GSH-mediated biotransformation in liver with -weighted magnetic resonance imaging (MRI). This imaging technique reveals the periodic variations in GSH concentration during the degradation of AFMO-ZDS NPs due to the limited transportation capacity of GSH carriers in the course of GSH efflux from hepatocytes to perisinusoidal space, providing direct imaging evidence for this important carrier-mediated process during GSH-mediated biotransformation.

Reversible redox-responsive H/F MRI molecular probes.

Herein we report a pair of redox-responsive manganese complexes Mn(iii)/(ii)-N,N'-bis(2-hydroxy-4-trifluoromethylbenzyl)ethylenediamine-N,N'-diacetate (HTFBED, L1), which are water soluble and biologically interconvertible, as reversible redox-responsive probes in 1H/19F MRI for detecting and imaging biological redox species, offering a means to access valuable redox information associated with various diseases.

DOTA-Branched Organic Frameworks as Giant and Potent Metal Chelators.

Multinuclear complexes as metallo-agents for clinical use have caught extensive attention. In this paper, using 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) as both a functioning unit and a constructing junction, we build a series of DOTA-branched organic frameworks with multiple chelating holes by organizing DOTA layer by layer. These giant chelators are well characterized, which reveals their nanosized and soft structures.

Directional assembly of a stapled α-helical peptide.

The de novo design of stapled peptide-based self-assemblies attracts vast interest, yet still remains challenging. The development of an oxidation trigger for peptide stapling and subsequent self-assembly is described here. A self-assembling sequence, Fmoc-R(RCEX)2-NH2, transformed from a random coil to an α-helical structure upon disulphide bonding of the flanking cysteine residues positioning at the i/i + 4 locations.

A gadolinium-complex-based theranostic prodrug for in vivo tumour-targeted magnetic resonance imaging and therapy.

Here we report a target-specific theranostic prodrug (1a) containing Gd-DOTA, biotin, and camptothecin (CPT) along with a disulfide self-immolative linker. This prodrug exhibits selective targeting towards tumour cells and tissues, stimuli-responsive controlled release, enhanced anticancer efficacy, and accurate diagnosis and real-time monitoring via contrast-enhanced magnetic resonance imaging (MRI).

Erratum: In-Tether Chiral Center Induced Helical Peptide Modulators Target p53-MDM2/MDMX and Inhibit Tumor Growth in Stem-Like Cancer Cell: Erratum.

[This corrects the article DOI: 10.7150/thno.19840.

Iron-oxide-based twin nanoplates with strong T relaxation shortening for contrast-enhanced magnetic resonance imaging.

Iron oxide nanomaterials have been intensively investigated over the past few decades as magnetic resonance imaging (MRI) contrast agents (CAs) due to their favorable magnetism and excellent biocompatibility. However, commercial iron-oxide-nanoparticle-based CAs suffer from low T2 relaxivity, which significantly limits their applications in the biomedical field. Herein, we report a new type of iron oxide nanoplate (IOP) with an interesting twinning plane, which is fabricated via seed growth.

Facile Chemoselective Modification of Thio-Ethers Generates Chiral Center-Induced Helical Peptides.

A precisely positioned sulfimide chiral center on-tether of a thio-ether tethered peptide determines the peptide secondary structure by chemoselective oxaziridine modification. This method provides a facile way to tune peptides' secondary structures and biophysical properties.

A Self-Assembled Biocompatible Nanoplatform for Multimodal MR/Fluorescence Imaging Assisted Photothermal Therapy and Prognosis Analysis.

The need for better imaging assisted cancer therapy calls for new biocompatible agents with excellent imaging and therapeutic capabilities. This study successfully fabricates albumin-cooperated human serum albumin (HSA)-GGD-ICG nanoparticles (NPs), which are comprised of a magnetic resonance (MR) contrast agent, glycyrrhetinic-acid-modified gadolinium (III)-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetate (GGD), and a fluorescence (FL) dye, indocyanine green (ICG), for multimodal MR/FL imaging assisted cancer therapy. These HSA-GGD-ICG NPs with excellent biocompatibility are stable under physiological conditions, and exhibit enhanced T contrast capability and improved fluorescence imaging capacity.

Surface manganese substitution in magnetite nanocrystals enhances T contrast ability by increasing electron spin relaxation.

Magnetite nanoparticles, with good biocompatibility and favorable magnetic properties, have the potential to be the best candidate for non-gadolinium MRI contrast agents. However, they usually show low T contrast ability, largely because Fe(ii) ions have a short electronic relaxation time and also have a small number of unpaired electrons with inefficient proton relaxation enhancement. Herein, we report a novel strategy to increase the T contrast ability of magnetite nanoparticles, through substituting the undesirable Fe(ii) ions with Mn(ii) ions.

In-Tether Chiral Center Induced Helical Peptide Modulators Target p53-MDM2/MDMX and Inhibit Tumor Growth in Stem-Like Cancer Cell.

Inhibition of the interaction between p53 and MDM2/MDMX has attracted significant attention in anticancer therapy development. We designed a series of in-tether chiral center-induced helical stabilized peptides, among which MeR/PhR effectively reactivated p53. The activation of p53 inhibits cell proliferation and induces apoptosis in both the MCF-7 normal tumor cell line and the PA-1 pluripotent cancer cell line with only minimal cellular toxicity towards normal cells or cancer cell lines with p53 mutations.

Geometrical confinement directed albumin-based nanoprobes as enhanced T contrast agents for tumor imaging.

There is an urgent demand for the development of new magnetic resonance imaging (MRI) contrast agents (CAs) with high T contrast ability and good biocompatibility. Herein, we report a novel albumin-based nanoprobe loaded with ibuprofen-modified gadolinium chelates, named Ibu-Gd-BSA nanoparticles (NPs). The interfacial pore structure among the albumin molecules endows the Ibu-Gd-BSA NPs with geometrical confinement, which could prolong the rotational correlation time (τ) of CAs and the diffusion correlation time (τ) of water molecules trapped within the pores.

Development of a high quantum yield dye for tumour imaging.

A fluorescent dye, FEB, with high fluorescence quantum yield for tumour imaging is reported. FEB dyes can be efficiently synthesized in three steps and then easily modified with either PEG or PEG-iRGD to yield FEB-2000 or FEB-2000-iRGD, respectively. Both modified dyes showed negligible toxicity and were thus able to be adopted for tumour imaging.

Reversible and Versatile On-Tether Modification of Chiral-Center-Induced Helical Peptides.

Modification of the cross-linker of constrained peptides has recently received considerable attention. Here, we present a versatile approach to modifing the cross-linking tether of chiral-center-induced helical (CIH) peptides via the S-alkylation reaction. The alkylation process displayed high conversion efficiency, selectivity, and substrate tolerance.

A precisely positioned chiral center in an i, i + 7 tether modulates the helicity of the backbone peptide.

In some cases, helical peptides stabilized by an i, i + 7 tether exhibit better target binding and cellular functions compared to their i, i + 4 analogues. Herein, we carried out a systematic study of the effects of an in-tether chiral center on the i, i + 7 system. We screened the optimal cross linking mode, tether length, in-tether chiral center positions, and absolute configurations.

Dual In-Tether Chiral Centers Modulate Peptide Helicity.

The facile chemical modification on the peptide cross-linking moiety is an important strategy for improving the physicochemical properties of a peptide. Herein, peptides were constrained into helical conformations via the synergistic effects of dual in-tether chiral centers. A pentapeptide minimalistic model was used to determine the correlation between the absolute configurations of the dual in-tether chiral centers and the secondary structures of the peptides.

Investigation of Cellular Uptakes of the In-Tether Chiral-Center-Induced Helical Pentapeptides.

We recently reported that a precisely positioned in-tether chiral center can modulate backbone peptides' secondary structures, which provides an unbiased platform to evaluate peptides' biophysical properties solely imposed by secondary structure differences. In this work, we studied the cellular uptake efficiency and mechanism of epimer pairs of a panel of chirality-induced helical peptides (CIH peptides). Although the peptides' cellular uptake is a synergetic result of various factors, our results unambiguously indicate that helical content is an important factor for the cellular uptake of CIH peptides.

Water bridge coordination on the metal-rich facets of GdO nanoplates confers high T relaxivity.

The realization of the nature of water coordination on the solid surfaces may provoke an essential understanding of T relaxation enhancement, especially in nanoparticulate systems. We report herein that the T relaxivity of GdO nanoplates is highly dependent on water coordinating behaviors on different surfaces. GdO nanoplates with metal-rich {100} facets showed an approximately 4-fold higher r value compared to that with oxygen-terminated {111} facets.

An In-tether Chiral Center Modulates the Helicity, Cell Permeability, and Target Binding Affinity of a Peptide.

The addition of a precisely positioned chiral center in the tether of a constrained peptide is reported, yielding two separable peptide diastereomers with significantly different helicity, as supported by circular dichroism (CD) and NMR spectroscopy. Single crystal X-ray diffraction analysis suggests that the absolute configuration of the in-tether chiral center in helical form is R, which is in agreement with theoretical simulations. The relationship between the secondary structure of the short peptides and their biochemical/biophysical properties remains elusive, largely because of the lack of proper controls.