Ratiometric Near-Infrared Fluorescent Probe Monitors Ferroptosis in HCC Cells by Imaging HClO in Mitochondria.

Hypochlorous acid (HClO) is a typical endogenous ROS produced mainly in mitochondria, and it has strong oxidative properties. Abnormal HClO levels lead to mitochondrial dysfunction, strongly associated with various diseases. It has been shown that HClO shows traces of overexpression in cells of both ferroptosis and hepatocellular carcinoma (HCC).

A near-infrared fluorescent probe with remarkably large stokes shift for specifical imaging of peroxynitrite fluctuations in Hela cells.

Peroxynitrite (ONOO), an endogenous reactive nitrogen species, plays an important role in maintaining intracellular homeostasis. Abnormal levels of ONOO in cells could cause protein oxidation which is confirmed that related with Alzheimer's diseases, so accurate monitoring of ONOO in cells is crucial. Herein, a novel fluorescent probe (XPC) based on dicyanomethylene-4H-benzothiopyran was developed by regulating its intramolecular charge transfer (ICT) effect to detect ONOO.

Rational design of a far-red fluorescent probe for endogenous biothiol imbalance induced by hydrogen peroxide in living cells and mice.

Intracellular biothiols are correlated with many diseases such as nerve disorder and Parkinson's disease likely due to a redox imbalance. In this work, we designed an ultrafast fluorescent probe (Cou-DNBS) for biothiols with a large Stokes shift (131 nm). The probe was constructed through linking the 2,4-dinitrobenzenesulfonyl moiety as the specially recognizing biothiols site to an iminocoumarin fluorophore Cou-NH obtained by fusing an additional benzene ring.

A dual-emission fluorescent probe for discriminating cysteine from homocysteine and glutathione in living cells and zebrafish models.

Cellular biothiols function crucially and differently in physiological and pathological processes. However, it is still challenging to detect and discriminate thiols within a single one molecule, especially for cysteine (Cys) and homocysteine (Hcy). In this study, a simple two-emission turn-on fluorescent biothiol probe (ICN-NBD) was rationally designed and synthesized through a facile ether bond linking 7-nitro-1,2,3-benzoxadiazole (NBD) and phenanthroimidazole containing a cyano tail.

Fluorometric and colorimetric dual-readout alkaline phosphatase activity assay based on enzymatically induced formation of colored Au@Ag nanoparticles and an inner filter effect.

An ultrasensitive fluorometric and colorimetric dual-mode assay is described for the determination of the activity of alkaline phosphatase (ALP). ALP catalyzes the decomposition of 2-phospho-L-ascorbic acid, and the ascorbic acid thus generated reduces silver ions. In the presence of gold nanoparticles, gold-silver nanoparticles (Au@Ag NPs) are formed.

A two-separated-emission fluorescent probe for simultaneous discrimination of Cys/Hcy and GSH upon excitation of two different wavelengths.

It is challenging to simultaneously discriminate two or three biothiols from each other due to their structural similarities as well as reactions sites. The development of multiple-signal fluorescent probes would be a promising way to overcome this issue. Herein, a two-separated-emission fluorescent probe for biothiols was developed based on the combination of nitrobenzofurazan (NBD) and phenanthroimidazole fluorophores linked by a facile ether bond.

Effects of Positive and Negative Expectations on Human Pain Perception Engage Separate But Interrelated and Dependently Regulated Cerebral Mechanisms.

Expectations substantially influence pain perception, but the relationship between positive and negative expectations remains unclear. Recent evidence indicates that the integration between pain-related expectations and prediction errors is crucial for pain perception, which suggests that aversive prediction error-associated regions, such as the anterior insular cortex (aIC) and rostral anterior cingulate cortex (rACC), may play a pivotal role in expectation-induced pain modulation and help to delineate the relationship between positive and negative expectations. In a stimulus expectancy paradigm combining fMRI in healthy volunteers of both sexes, we found that, although positive and negative expectations respectively engaged the right aIC and right rACC to modulate pain, their associated activations and pain rating changes were significantly correlated.

Ultra-fast zinc ion detection in living cells and zebrafish by a light-up fluorescent probe.

As the second most abundant transition metal after iron in biological systems, Zn takes part in various fundamental life processes such as cellular metabolism and apoptosis, neurotransmission. Thus, the development of analytical methods for fast detection of Zn in biology and medicine has been attracting much attention but still remains a huge challenge. In this report, we develop a novel Zn-specific light-up fluorescent probe based on intramolecular charge transfer combined with chelation enhanced fluorescence induced by structural transformation.

Rhodium(III)-Catalyzed C(sp)-H Bond Aminocarbonylation with Isocyanates.

Rh(III)-catalyzed C(sp)-H bond aminocarbonylation of 8-methylquinolines and isocyanates has been realized under mild conditions. This approach is applicable to different aryl and alkyl isocyanates, leading to the synthesis of various α-quinolinyl amide compounds in moderate to excellent yields. A plausible mechanism for this transformation is proposed according to the experimental results obtained.

A fast-response two-photon fluorescent probe for imaging endogenous HO in living cells and tissues.

As a second messenger, hydrogen peroxide plays significant roles in numerous physiological and pathological processes and is related to various diseases including inflammatory disease, diabetes, neurodegenerative disorders, cardiovascular disease and Alzheimer's disease. Two-photon (TP) fluorescent probes reported for the detection of endogenous HO are rare and most have drawbacks such as slow response and low sensitivity. In this report, we demonstrate a simple HO-specific TP fluorescent probe (TX-HP) containing a two-photon dye 6-hydroxy-2,3,4,4a-tetrahydro-1H-xanthen-1-one (TX) on the modulation of the ICT process.

Two Distinctly Separated Emission Colorimetric NIR Fluorescent Probe for Fast Hydrazine Detection in Living Cells and Mice upon Independent Excitations.

Hydrazine is carcinogenic and highly toxic so that it can lead to serious environmental contamination and serious health risks although it has been extensively used as an effective propellant and an important reactive base in industry. Thus, the development of two-emission NIR fluorescent probes for rapid detection of hydrazine with high selectivity and sensitivity is of significance and of great challenge in both biological and environmental sciences. Here, we report a two-emission colorimetric fluorescent probe for the specific detection of hydrazine based on hydrazinolysis reaction under physiological conditions.

A Fluorescent Probe for Hydrogen Peroxide in Vivo Based on the Modulation of Intramolecular Charge Transfer.

Endogenous hydrogen peroxide in vivo is related to many diseases, including cancer, diabetes, cardiovascular disease, and neurodegenerative disorders. Although many probes for detection of HO have been explored, rapid response probes are still expected for in vivo application. Here, a new probe (PAM-BN-PB) was designed based on an intramolecular charge transfer (ICT) process with three parts: phenanthroimidazole, benzonitrile, and phenyl boronate.

A simple fluorescent probe for sensing cysteine over homocysteine and glutathione based on PET.

A big challenge is the discrimination of sulfhydryl-containing amino acids due to their structural similarity. We designed and synthesized a simple fluorescent probe 3 for specific detection of cysteine based on photo-induced electron transfer (PET). The acrylate and BODIPY moieties in probe 3 act as a reaction site and reporter group, respectively.

[2,5-Bis(2,2'-bipyridyl-6-yl)-3,4-diazahexa-2,4-diene]dichloridomanganese(II): from a mononuclear compound to a three-dimensional supramolecular framework through C-H···Cl hydrogen bonds and π-π stacking interactions.

The title compound, [MnCl2(C24H20N6)], has been synthesized and characterized based on the multifunctional ligand 2,5-bis(2,2'-bipyridyl-6-yl)-3,4-diazahexa-2,4-diene (L). The Mn(II) centre is five-coordinate with an approximately square-pyramidal geometry. The L ligand acts as a tridendate chelating ligand.

Ring-Opening Polymerization of -Lactide with Aluminum Chiral Anilido-Oxazolinate Complexes.

A series of dimethylaluminum complexes )AlMe (-, where = 2-(2'-ArNH)phenyl-4-R-oxazoline) bearing chiral, bidentate anilido-oxazolinate ligands have been prepared and characterized. Six of the complexes, in the presence of an alcohol cocatalyst, are shown to be active initiators for the stereoselective ring-opening polymerization of -lactide in toluene solution and under bulk conditions, yielding polylactides with a range of tacticity from slightly isotactic to moderately heterotactic. The reactivity and selectivity of these catalysts are discussed on the basis of the effect of their substituents.

Unexpected formation of chiral pincer CNN nickel complexes with β-diketiminato type ligands via C-H activation: synthesis, properties, structures, and computational studies.

Reaction of lithiated chiral, unsymmetric β-diketimine type ligands HL(2a-e) containing oxazoline moiety (HL(2a-e) = 2-(2'-R(1)NH)-phenyl-4-R(2)-oxazoline) with trans-NiCl(Ph)(PPh(3))(2) afforded a series of new chiral CNN pincer type nickel complexes (3a-3e) via an unexpected cyclometalation at benzylic or aryl C-H positions. Single crystal X-ray diffraction analysis established the pincer coordination mode and the strained conformation. Chirality, and in one case, racemization of the target nickel complexes were confirmed by circular dichroism (CD) spectroscopy.

3D simulation of morphological effect on reflectance of Si3N4 sub-wavelength structures for silicon solar cells.

In this study, we investigate the reflectance property of the cylinder, right circular cone, and square pyramid shapes of silicon nitride (Si3N4) subwavelength structure (SWS) with respect to different designing parameters. In terms of three critical factors, the reflectance for physical characteristics of wavelength dependence, the reflected power density for real power reflection applied on solar cell, and the normalized reflectance (reflected power density/incident power density) for real reflectance applied on solar cell, a full three-dimensional finite element simulation is performed and discussed for the aforementioned three morphologies. The result of this study shows that the pyramid shape of SWS possesses the best reflectance property in the optical region from 400 to 1000 nm which is useful for silicon solar cell applications.

A novel three-dimensional CdII coordination polymer: poly[[aquabis(2,2'-bipyridine)(μ5-pyrazol-1-ide-3,5-dicarboxylato)(μ4-pyrazol-1-ide-3,5-dicarboxylato)(μ3-pyrazole-3,5-dicarboxylato)tetracadmium(II)] dihydrate].

The title compound, {[Cd(4)(C(5)H(2)N(2)O(4))(C(5)HN(2)O(4))(2)(C(10)H(8)N(2))(2)(H(2)O)]·2H(2)O}(n), crystallized in the monoclinic space group P2(1)/n and displays a three-dimensional architecture. The asymmetric unit is composed of four crystallographically independent Cd(II) centres, two triply deprotonated pyrazole-3,5-dicarboxylic acid molecules, one doubly deprotonated pyrazole-3,5-dicarboxylic acid molecule, two 2,2'-bipyridine ligands, one coordinated water molecule and two interstitial water molecules. Interestingly, the Cd(II) centers exhibit two different coordination numbers.

Selective, catalytic aerobic oxidation of alcohols using CuBr(2) and bifunctional triazine-based ligands containing both a bipyridine and a TEMPO group.

Three novel, bifunctional triazine-based ligands, namely , and , containing both a TEMPO and a bipyridine moiety have been synthesized. These bpy/TEMPO-based molecules have been used as catalyst precursors for the copper-catalyzed aerobic oxidation of alcohols to aldehydes and ketones, in the presence of tert-BuOK as co-catalyst. The complexes obtained in situ from ligands and with copper(II) bromide in a 2:1 acetonitrile/water mixture, selectively catalyze the aerobic oxidation of primary benzylic, allylic and aliphatic alcohols and secondary benzylic alcohols.

A copper complex bearing a TEMPO moiety as catalyst for the aerobic oxidation of primary alcohols.

A new bifunctional, triazine-based ligand has been designed with the aim to generate a copper(II) complex holding a TEMPO (2,2,6,6-tetramethylpiperidinyloxy) moiety. The coordination compound obtained from the ligand 4-(2-(3-(pyridin-2-yl)-1H-pyrazol-1-yl)ethoxy)-6-(4-amino-2,2,6,6-tetramethylpiperidine-1-oxyl)-N,N-diphenyl-1,3,5-triazin-2-amine (pypzt-1) and copper(II) bromide (i.e.

Syntheses, crystal structures, and magnetic characterization of five new dimeric manganese(III) tetradentate Schiff base complexes exhibiting single-molecule-magnet behavior.

Tetradentate Schiff base ligands H2L (H2saltmen, H2salen, H2-5-Brsalen, and H2-3,5-Brsalen), derived from the condensation of the corresponding salicylaldehyde or its derivatives with 1,1,2,2-tetramethylethyldiamine or 1, 2-diaminoethane, reacted with Mn(III) acetate or perchlorate salts and sodium azide or sodium cyanate to produce five Mn(III) dimer complexes, [Mn(saltmen)(O2CCH3)]2.2CH3CO2H (1), [Mn(saltmen)(N3)]2 (2), [Mn(salen)(NCO)]2 (3), [Mn(3,5-Brsalen)(3,5-Brsalicylaldehyde)]2 (4), and [Mn(5-Brsalen)(CH3OH)]2(ClO4)2 (5). These new complexes have been characterized by IR, elemental analyses, crystal structural analyses, and magnetic studies.

Tuning the magnetic behavior via dehydration/hydration treatment of a new ferrimagnet with the composition of K0.2Mn1.4Cr(CN)6 x 6H2O.

A new complex (1) of Prussian blue analogue with the composition of K0.2Mn1.4Cr(CN)6 x 6H2O was prepared and characterized structurally as well as magnetically.

7-trifluoromethylquinoline-functionalized luminescent photochromic spiropyran with the stable merocyanine species both in solution and in the solid state.

A new spiropyran (SP2) with the stable merocyanine form (MC2) both in solution and in the solid state at room temperature was designed and synthesized. The stability of MC2 is believed to be due to the electron-withdrawing effect of both the quinoline and the trifluoromethyl groups. (1)H NMR spectra indicate that the ratio of the open form vs the closed form of SP2 is dependent on the polarity of solvents.