Coordination Synergistic-Induced -Aggregation Enhanced Fluorescent Performance of HBT-Excimers and Imaging Applications.

Developing a novel strategy to improve the optical performances of fluorescent probes is a vital factor in elevating its practical application; viz., novel biocompatible fluorescent probes with excellent multifunctions exhibited unparalleled advantages in probing functions of intracellular molecules to elucidate intracellular events in living systems. Herein, we have successfully constructed a new strategy that aggregation and coordination synergistically induce (2-hydroxylphenyl-benzothiazole) HBT derivatives to form excimers with large red-shifted fluorescence and application for insight into stress-response zinc fluctuations in living systems.

Transcriptional regulation of cellobiose utilization by PRD-domain containing Sigma54-dependent transcriptional activator (CelR) and catabolite control protein A (CcpA) in .

Cellobiose, a β-1,4-linked glucose dimer, is a major cellodextrin resulting from the enzymatic hydrolysis of cellulose. It is a major source of carbon for soil bacteria. In bacteria, the phosphoenolpyruvate (PEP): carbohydrate phosphotransferase system (PTS), encoded by the operon, is responsible for the transport and utilization of cellobiose.

Unraveling the complex dynamics of signaling molecules in cellular signal transduction.

Signaling molecules in cellular responses to foreign stimuli are described as static up- or down-concentration changes during signal transduction. This is because analytical methods for transducing molecules are much slower than the signaling events. In this study, we develop a dynamic cell model and reveal the temporal regulation of signal transduction events in response to reactive oxygen species (ROS).

Waste iron scraps promote anammox bacteria to resist inorganic carbon limitation.

The anaerobic ammonium oxidation (anammox) process is adversely affected by the limitation of inorganic carbon (IC). In this research, a new technique was introduced to assist anammox biomass in counteracting the adverse effects of IC limitation by incorporating waste iron scraps (WIS), a cheap and easily accessible byproduct of lathe cutting. Results demonstrated that reducing the influent IC/TN ratio from 0.

Development of fluorescent probes with specific recognition moiety for hydrogen polysulfide.

Hydrogen polysulfide (HS, n > 1) is an important component of reactive sulfur species (RSS), which is an important substance for maintaining the redox balance in cells. However, limited recognition moieties are available for hydrogen polysulfide probe design. In this study, we have constructed a small library containing several organic molecules to explore a new specific recognition moiety for HS fluorescent probe design.

Superselective renal arterial embolization for severe postpercutaneous nephrolithotomy haemorrhage: clinical characteristics and risk factors for initial failure.

Objective: To identify the clinical characteristics of patients who underwent superselective renal arterial embolization (SRAE) after percutaneous nephrolithotomy (PCNL) and to explore the risk factors for failed initial SRAE after PCNL.

Materials And Methods: Patients who underwent SRAE for severe haemorrhage following PCNL between January 2014 and December 2020 were included in the study. The clinical data of those patients and the parameters and characteristics of the perioperative PCNL and SRAE procedures were collected and analysed.

Design and Synthesis of Neutralizable Fondaparinux.

Fondaparinux, a clinically approved anticoagulant pentasaccharide for the treatment of thrombotic diseases, displays better efficacy and biosafety than other heparin-based anticoagulant drugs. However, there is no suitable antidote available for fondaparinux to efficiently manage its potential bleeding risks, thereby precluding its widespread use. Herein, we describe a convergent and stereocontrolled approach to efficiently synthesize an aminopentyl-functionalized pentasaccharide, which is further used to prepare fondaparinux-based biotin conjugates and clusters.

Fluorescent imaging to provide visualized evidences for mercury induced hypoxia stress.

As one typical toxic and dangerous heavy metal, mercury brings incalculable hazards to the environment and human, the mechanism at the molecular level is unclear. There is no visualized evidence to support directly that mercury ions (Hg) exposure may induce secondary stress, which is associated with the risk of hypoxia microenvironment in biological systems. Hypoxia occurs in many physiological and pathophysiological processes in the living system, accompanying overexpression of various biomarkers, such as nitroreductase (NTR).

A small molecule fluorescent probe for mercury ion analysis in broad low pH range: Spectral, optical mechanism and application studies.

Development of new fluorescent probes for mercury ion analysis in environmental or living organism is undergoing quick growth due to its detrimental toxicity to environmental safety, ecological security, and human being. However, in most cases, the industrial waste water is acidic whereas it remains a great challenge to real-time monitor mercury ion directly at low pH using small molecule fluorescence probe. In this study, we have successfully designed and synthesized the Naph (1, 8-Naphthalimide derivative) -based small molecule probe termed as Naph-NSS capable of monitoring mercury ion in a broad range at low pH (from 2.

Insight into sulfur dioxide and its derivatives metabolism in living system with visualized evidences via ultra-sensitive fluorescent probe.

Sulfur dioxide (SO) and its derivatives have long been considered as hazardous environmental pollutants but commonly used as food additives in safe dose range. They also could be produced from biological metabolism process of sulfur-containing amino acids. However, their physiological roles remain extremely obscure mainly due to lack of efficient tools for monitoring and imaging strategy establishment.

Visualizing and evaluating mitochondrial cysteine via near-infrared fluorescence imaging in cells, tissues and in vivo under hypoxia/reperfusion stress.

Increasingly grim environmental pollutions are closely related with the occurrence and development of diseases. However, it's obscure how environmental stress disturbs the normal physiological process, and then how endogenous reactive species mend the cases. Hypoxia/reperfusion (H/R), a common and intractable injury in aquaculture and clinic, can induce oxidative stress and ultimately cause irreversible injury to organism.

Evaluation of cyclooxygenase-2 fluctuation via a near-infrared fluorescent probe in idiopathic pulmonary fibrosis cell and mice models.

Idiopathic pulmonary fibrosis (IPF) is a devastating and fatal interstitial lung disease due to various challenges in diagnosis and treatment. Due to its complicated pathogenesis and difficulty in early diagnosis, there is no effective cure. Cyclooxygenase-2 (COX-2) is inextricably associated with pulmonary fibrosis.

A cysteine-selective fluorescent probe for monitoring stress response cysteine fluctuations.

Rare studies provided evidence for the real-time monitoring of stress response cysteine fluctuations. Here, we have successfully designed and synthesized a cysteine-selective fluorescent probe 1 to monitor stress response Cys fluctuations, providing visual evidence of Hg2+ regulated cysteine fluctuations for the first time, which may open a new way to help researchers to reveal the mechanism of heavy metal ion poisoning.

A chemical covalent tactic for bio-thiol sensing and protein labeling agent design.

Discovering novel chemical reactions is important for bioanalysis. Herein, we report a tactic for bio-thiol sensing and protein labeling agent design by the installation of a sulfoxide group onto the skeleton of various fluorophores, and powerfully validate its abilities, which may shed light on the development of specific protein tags to give insight into their biological functions.

A reaction-based ratiometric fluorescent probe for mercury ion detection in aqueous solution.

Mercury ions are crucially harmful to ecosystem and human being due to their characters of bioaccumulation and difficulty of biochemical degradation. Therefore, development of mercury ion detection methods has attracted increasing interests recently. In this study, we successfully synthesized a hydroxyphenylbenzothiazole (HBT)-based fluorescent probe HBT-Hg in an extremely simple manner for mercuric ions detection.

A near-infrared fluorescent probe for observing thionitrous acid-mediated hydrogen polysulfides formation and fluctuation in cells and in vivo under hypoxia stress.

Hydrogen polysulfides (HS, n>1) as important intracellular reactive sulfur species (RSS) are believe to be responsible for cellular redox regulation. Lots of researches about HS focusing on their formation, detection and bio-function in signalling regulation are spring up but with poor understanding, especially for biosynthesis and bio-function remain complicated and confusing. Recent studies reveal that thionitrous acid (HSNO) as potential intermediate linked signalling molecules of nitrogenous and sulphureous during biotic redox regulation.

Detection of hypochlorous acid fluctuation via a selective near-infrared fluorescent probe in living cells and in vivo under hypoxic stress.

Hypoxic stress is a common concern in medicine and biology, which can induce the cellular injury and death by excess production of reactive oxygen species (ROS). Hypochlorous acid (HOCl), one of the ROS, plays a crucial role in the oxidative damage to tissue proteins in the pathogenesis of various diseases. Therefore, excess production of HOCl might be an important factor for the damage caused by hypoxic stress.

Glutathione Peroxidase-Activatable Two-Photon Ratiometric Fluorescent Probe for Redox Mechanism Research in Aging and Mercury Exposure Mice Models.

Solid evidence confirms that glutathione peroxidase (GPx) is a kind of vital protease in the first-line antioxidant defense system and participates in regulation of redox homeostasis as well as the pentose phosphate pathway. However, the current methods cannot achieve real-time and in situ visualization studies of GPx. In addition, GPx is highly reactive and susceptible to external interference, and there is rare research for exploring the roles of GPx under environmental factor exposure.

Evaluating the Protective Effects of Mitochondrial Glutathione on Cerebral Ischemia/Reperfusion Injury via Near-Infrared Fluorescence Imaging.

Cerebral ischemia/reperfusion (I/R) is common and intractable in the clinic, associated with the outburst of reactive oxygen species (ROS) in mitochondria. Although numerous research studies have been conducted to prove the protective-effect roles of glutathione (GSH) in this event, the changes in GSH concentrations in living cells remain largely unexplained, and there is scarce evidence by fluorescence imaging for its roles. Herein we have designed and synthesized two distinctive "off-on" near-infrared (NIR) fluorescent probes BCy-SeSe and BCy-SS based on a new fluorophore BCy-Keto for specific response to mitochondrial GSH changes during the cerebral I/R process.

High Spatiotemporal Resolution Observation of Glutathione Hydropersulfides in Living Cells and Tissue via a Two-Photon Ratiometric Fluorescent Probe.

Glutathione hydropersulfides (GSSH) are alluded to play crucial roles in signal transduction, redox homeostasis, and metabolic regulation. However, the detailed biological functions of GSSH in these aspects are extremely ambiguous. The key barrier to understand the role of GSSH in biological systems is a lack of detection tools with high spatiotemporal resolution.

A near-infrared fluorescent probe for evaluating endogenous hydrogen peroxide during ischemia/reperfusion injury.

Hydrogen peroxide (H2O2), as a major component of reactive oxygen species (ROS), plays an important role in normal physiological processes. A H2O2 burst also occurs in the ischemia/reperfusion (I/R) process and causes a series of physiological and pathological injuries. Therefore, it is important to determine concentration fluctuations of H2O2.

A ratiometric fluorescent probe of methionine sulfoxide reductase with an improved response rate and emission wavelength.

A ratiometric fluorescent probe of methionine sulfoxide reductase, Msr-Ratio, was disclosed for monitoring the enzyme activity in vitro and in live cells. The probe displayed favorable properties such as a nearly 400-fold fluorescence change, fast response rate (<30 min), large Stokes shift (120 nm), and green emission (550 nm).

Dictyoptesterols A-C, ∆-24-oxo cholestane-type sterols with potent PTP1B inhibitory activity from the brown alga Dictyopteris undulata Holmes.

Three new cholestane-type sterols bearing an unusual ∆-24-oxo side chain, namely, dictyoptesterols A-C (1-3), were isolated from the brown alga Dictyopteris undulata Holmes, together with five known strutural analogues (4-8). Their structures were elucidated on the basis of by extensive spectroscopic analysis. The absolute configurations of the steroidal nuclei of the new compounds were proposed by a comparison of NMR data with those of related known compounds as well as biogenetic considerations.

Intermolecular interactions between σ- and π-holes of bromopentafluorobenzene and pyridine: computational and experimental investigations.

The characters of σ- and π-holes of bromopentafluorobenzene (C6F5Br) enable it to interact with an electron-rich atom or group like pyridine which possesses an electron lone-pair N atom and a π ring. Theoretical studies of intermolecular interactions between C6F5Br and C5H5N have been carried out at the M06-2X/aug-cc-pVDZ level without and with the counterpoise method, together with single point calculations at M06-2X/TZVP, wB97-XD/aug-cc-pVDZ and CCSD(T)/aug-cc-pVDZ levels. The σ- and π-holes of C6F5Br exhibiting positive electrostatic potentials make these sites favorably interact with the N atom and the π ring of C5H5N with negative electrostatic potentials, leading to five different dimers connected by a σ-holen bond, a σ-holeπ bond or a π-holeπ bond.

PBr-Mediated Cyclization of 1,7-Diyn-3,6-bis(propargyl carbonate)s: Synthesis of 5-Bromotetracenes.

A new and straightforward method for the synthesis of 5-bromotetracenes through PBr-mediated cyclization of 1,7-diyn-3,6-bis(propargyl carbonate)s has been developed. This method offers several advantages such as easily accessible starting materials, high efficiency, and wide functional group compatibility. In addition, chloro- and iodo-substituted tetracenes were also synthesized using appropriate halogenating reagents.