A fluorescent probe based on cyclochalcone for detecting peroxynitrite.

A novel cyclic chalcone fluorescent probe C-PN was synthesized to detect ONOO-. After reaction with peroxynitrite, the double bond of C-PN in the cyclic chalcone structure was disconnected, which caused the change of intramolecular charge transfer (ICT) effect, emitting blue fluorescence and quenching orange red fluorescence. Visible to the naked eye, the color of the probe solution changed. The probe showed low sensitivity (detection limit = 20.2 nm), short response time (less than 60 s) at low concentration of ONOO-, good visibility, and good selectivity and stability for ONOO-.

Silencing of FGF6 hampers aerobic glycolysis and angiogenesis in bladder cancer by regulating PI3K/Akt and MAPK signaling pathways.

Metabolic abnormalities and uncontrolled angiogenesis are two vital features of malignant tumors. Although fibroblast growth factor 6 (FGF6) is known to promote the proliferation and migration of bladder cancer (BC) cells, its influences on aerobic glycolysis and angiogenesis in BC remain unclear. Gene expression at messenger RNA and protein levels were examined by reverse transcription-quantitative polymerase chain reaction and Western blot analyses, respectively. Lactate production and glucose uptake in BC cells were evaluated by performing aerobic glycolysis assays. A vasculogenic mimicry assay was executed for assessing the angiogenesis of BC cells. The viability, migration, and angiogenesis of human umbilical vein endothelial cells (HUVECs) cocultured with supernatants of BC cells were detected using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, wound healing assay, and tube formation assay. It was found that FGF6 displayed a high level in BC cell lines. Silencing of FGF6 reduced the levels of lactate production, glucose uptake, and the expression of angiogenic factors and glycolytic enzymes in BC cells, which also inhibited the viability and migration of HUVECs. In addition, FGF6 depletion or aerobic glycolysis inhibitor 2-deoxy-d-glucose treatment decreased the total branching length and intersection number of both BC cells and HUVECs. Moreover, glucose or lactate treatment reversed FGF6-induced suppression of cell viability, migration, tube formation, and vasculogenic mimicry. The activation of the phosphatidylinositol-3-kinase (PI3K)/protein kinase B (Akt) and mitogen-activated protein kinase (MAPK) signaling pathways was blocked by silenced FGF6. Furthermore, PI3K/Akt inhibitor (LY2940002) and p38-MAPK inhibitor (SB203580) inhibited the levels of aerobic glycolysis-related proteins. In conclusion, FGF6 knockdown suppressed aerobic glycolysis, thereby inhibiting angiogenesis in BC via regulation of the PI3K/Akt and MAPK signaling pathways.

Enhancing probe's sensitivity for peroxynitrite through alkoxy modification of dicyanovinylchromene.

An intramolecular charge transfer (ICT)-based fluorescent probe P-ONOO- was synthesized to detect ONOO-. After responding to peroxynitrite, the dicyano-vinyl group of P-ONOO- generates the aldehyde group, emitting strong green fluorescence accompanied by quenching of the yellow fluorescence. According to the calculated Fukui function, the modification of the alkoxy group can enhance the f+ of P-ONOO-, which can enhance the probe's nucleophilic addition reactivity with ONOO-. It has been experimentally verified that P-ONOO- shows fast response (within 30 s), excellent sensitivity (the detection limit = 10.4 nM), and good selectivity towards ONOO-. Additionally, the probe P-ONOO- has high membrane permeability and good biocompatibility, which can image endogenous ONOO- and exogenous ONOO- in HeLa cells.

A diazabenzoperylene derivative as ratiometric fluorescent probe for cysteine with super large Stokes shift.

Biothiols, including cysteine (Cys), homocysteine (Hcy), and glutathione (GSH), play key roles in biological processes, and detecting such thiols selectively is critical for understanding functions of biothiols. In this work, a pyridazine annelated perylene-based fluorescent probe PAPC is synthesized for highly selective detection of Cys. PAPC exhibits strong blue emission in PBS, while the red emission at 605 nm can be observed in the presence of Cys. The probe PAPC shows ratiometric fluorescence (I605/I460) detection of Cys with wide linear range of 1-120 µM and low detection limit of 0.19 µM. Super large Stokes shift (170 nm) and ratiometric fluorescence endow the probe low background signal. The discrimination of Cys over Hcy and GSH can be achieved through the difference of the ratiometric fluorescence. In addition, the probe has been proven to track Cys in real samples such as urine and HeLa cells. Therefore, PAPC probe is a promising candidate for detecting Cys in practical application. Graphical abstract.

Fluorine in the environment in an endemic fluorosis area in Southwest, China.

Soils in large areas of China are enriched in fluorine (F). The present study analyzed F concentrations in cultivated soil, water, chemical fertilizer, and human hair, and metal concentrations in soils from an endemic fluorosis area in Southwest, China. In order to reveal the effects of industry on F concentration in the environment, 3 towns mainly with agriculture production and another 3 towns with developed phosphorus chemical industry in a same city were selected for sample collection. The total F concentrations of the 277 surface agricultural soil samples were 378.79-1576.13 µg g-1, and F concentrations of nearly 95% of the soil samples were higher than the Chinese average topsoil F concentration (480 µg g-1). Only a small fraction (0.75%) of total F was water soluble. The average total F, water soluble F, Ca, Cr, Fe, K, Mn, Rb, and Sr concentrations in soil samples from towns with intensive industry were higher than those from towns mainly with agriculture. Significant correlations were found between soil pH with total F (p < 0.01) and with water soluble F concentration (p < 0.1). Low F concentrations (<0.5 mg L-1) were found in irrigation water, well water and tap water in a town where the industry is dense. The phosphorus fertilizer and compound fertilizer had hundreds of times of contribution to soil F increment than the nitrogen fertilizer and potassium fertilizer. Nearly half percent of F in the human hair samples was of exogenic origin. Based on soil ingestion pathway, the health risk for adults exposure to F in soils was acceptable, however, F may pose possible health risks to children in high F concentration areas.

Adult pancreatic hemangioma: a rare case report and literature review.

BACKGROUND: Adult pancreatic hemangioma is an extremely rare type of benign vascular tumor. To date, about 20 cases have been reported in the English literature. Adult patients with pancreatic hemangiomas usually have no specific symptoms, particularly in early stages. Therefore, it is difficult to detect and diagnose these lesions, which usually are identified during cross sectional imaging for an apparently unrelated causes or when biliary obstruction occurs because of compression by a tumor. CASE PRESENTATION: This study presents the case of a 52-year-old female with a chief complaint of epigastric pain. Contrast-enhanced computed tomography revealed a well-defined mass with mildly inhomogeneous enhancement in the body of the pancreas. Endoscopic ultrasonography showed calcifications in the lesion, and a few small vessels were detected by Doppler imaging. The patient received a central pancreatectomy, and pathological examination confirmed the diagnosis of pancreatic hemangioma. CONCLUSION: In this report, we reviewed the clinical manifestations, radiologic features, preoperative diagnosis, pathologic characteristics, and surgical treatment of adult pancreatic hemangioma.

A Host-Guest Supercapacitor Electrode Material Based on a Mixed Hexa-Transition Metal Sandwiched Arsenotungstate Chain and Three-Dimensional Supramolecular Metal-Organic Networks with One-Dimensional Cavities.

The mixed hexa-transition metal (hexa-TM) sandwiched arsenotungstate derivative, [CuI3(pz)2(phen)3]2[CuI(phen)2][{Na(H2O)2}{(VIV5CuIIO6)(AsIIIW9O33)2}]·6H2O (1) (pz = pyrazine; phen = 1,10-phenanthroline), has been hydrothermally synthesized and structurally characterized. In compound 1, two {AsW9O33} clusters are connected by mixed hexa-TM ring unit {VVI5CuIIO6} to form a sandwich-type dimer, which are further bonded in "ABAB" mode by the {Na(H2O)2} linker resulting in pure inorganic chains. The unique "L-shaped" trinuclear complex {Cu3(phen)3(pz)2} is supported together via staggered π-π interactions to generate extending waveform two-dimensional supramolecular layers, which are further aggregated with their adjacent analogues by complexes {Cu(phen)2} via H-bonding interaction to yield an unprecedented three-dimensional (3D) metal-organic networks with one-dimensional (1D) cavities. The pure inorganic 1D sandwich chains are implanted in the cavities as guest units via supramolecular interactions to form a POMOF 3D framework. Compound 1, as the electrode of the supercapacitor, exhibits higher specific capacitances (825 F g-1 at a current density of 2.4 A g-1), better rate capability, more durable cyclic stability (91.4% of cycle efficiency after 3000 cycles), and improved conductivity and electroactivity compared to those of parent polyoxometalate (POM) Na9[AsW9O33]·19H2O (2) and 6-Cu-substituted POM [Cu6(imi)6{AsIIIW9O30Cl3}2]·6H2O (3), which may be attributed to the introduction of V4+, the unique host-guest structure, and the rich π electron system. In addition, compound 1 exhibits dual-function electrocatalytic behavior in reducing inorganic salt IO3- and oxidizing the organic molecule dopamine.

Portal hypertension predicts short-term and long-term outcomes after hepatectomy in hepatocellular carcinoma patients.

BACKGROUND AND AIMS: The impact of portal hypertension (PH) on postoperative short-term outcomes and long-term survival in hepatocellular carcinoma (HCC) patients has lately been discussed controversially. This study aimed to explore the influence of PH on postoperative outcomes in HCC patients undergoing surgical resection. METHODS: Patients undergoing hepatectomy for HCC from 2010 to 2014 were enrolled. The impact of PH on postoperative complications, posthepatectomy liver failure (PHLF) and overall survival (OS) was evaluated. RESULTS: A total of 355 HCC patients were enrolled; 129 (36.3%) experienced postoperative complications and 21 (5.9%) developed PHLF. PH was identified as an independent predictor of PHLF. Patients with PH experienced a higher incidence of complications and PHLF than patients without PH. On the Cox proportional hazards regression model, PH was verified as a risk factor of OS for BCLC stage 0/A and B patients. Patients without PH had significantly better long-term survival compared to patients with PH both in the total cohort and in cirrhosis subgroup. CONCLUSION: Liver resection in HCC patients with PH showed a significantly increased postoperative complications and PHLF, and revealed a decreasing long-term survival than non-PH patients. Besides, tumor burden also played an important role in determining the OS. However, due to the improvement in surgical technique and perioperative management, surgery was feasible in carefully selected HCC patients with PH.

Highly Sensitive and Selective Turn-on Fluorescent Probe for Hg2+ Based on Rhodamine 6G-Thiourea Conjugate.

An easily available novel fluorescent probe based on rhodamine 6G-thiourea conjugate (RGTU) has been synthesized. Upon mixed with Hg2+ in CH3CN-H2O (1:9, v/v), the dramatic enhancement of fluorescence intensity as well as the color change of the solution were observed. The presence of common coexisting alkali, alkaline earth, and transition metal ions showed small or no interference with the detection of Hg2+. The Job's plot and 1H NMR spectra indicated that Hg2+ induced spirolactam open to form 1:1 complex between RGTU and Hg2+.

A highly Selective Fluorescent Chemosensor for Zn2+ Based on the Rhodamine Derivative Incorporating Coumarin Group.

A coumarin-appended rhodamine derivative was prepared by reacting rhodamine hydrazide and coumarin-3-carboxylic acid, which fluorescence sensing behavior toward Zn2+ against other metal ions was investigated in CH3CN. Significantly, the rodamine-coumarin derivative exhibited highly selective and sensitive recognition toward Zn2+ with a limit of detection (LOD) down to 10-9 M. Upon addition of Zn2+, remarkable fluorescent intensities enhanced and also clear color changed from colorless to pink. The Job's plot indicated the formation of 1:1 complex between the rhodamine-coumarin derivative and Zn2+. The presence of common coexisting alkali, alkaline earth, and transition metal ions showed small or no interference with the detection of Zn2+. The conjugate dye could be used for "naked-eye" detection of Zn2+.

Thiophene-based rhodamine as selectivef luorescence probe for Fe(III) and Al(III) in living cells.

The thiophene-modified rhodamine 6G (GYJ) has been synthesized as a novel chemosensor. The sensor has sufficiently high selectivity and sensitivity for the detection of Fe3+ and Al3+ ions (M3+) by fluorescence and ultraviolet spectroscopy with a strong ability for anti-interference performance. The binding ratio of M3+-GYJ complex was determined to be 2:1 according to the Job's plot. The binding constants for Fe3+ and Al3+ were calculated to be 3.91 × 108 and 5.26 × 108 M-2, respectively. All these unique features made it particularly favorable for cellular imaging applications. The obvious fluorescence microscopy experiments demonstrated that the probes could contribute to the detection of Fe3+ and Al3+ in related cells and biological organs with satisfying resolution. Graphical abstract GYJ has high selectivity and sensitivity for the detection of Fe(III) and Al(III) with the binding ratio of 2:1.

Synthesis of doubly ethyl-bridged bis(p-sulfonatocalix[4]arene) and its supramolecular polymerization with viologen dimer.

A water-soluble supramolecular polymer with a high degree of polymerization and viscosity has been constructed based on the strong host-guest interaction between p-sulfonatocalix[4]arenes (SC4As) and viologen. A homoditopic doubly ethyl-bridged bis(p-sulfonatocalix[4]arene) (d-SC4A) was prepared and its binding behavior towards methyl viologen compared with the singly ethyl-bridged bis(p-sulfonatocalix[4]arene) (s-SC4A) by NMR spectroscopy and isothermal titration calorimetry. By employing a viologen dimer (bisMV(4+)) as the homoditopic guest, two linear AA/BB-type supramolecular polymers, d-SC4A⊃bisMV(4+) and s-SC4A⊃bisMV(4+), were successfully constructed. Compared with s-SC4A⊃bisMV(4+), d-SC4A⊃bisMV(4+) shows much higher solubility and viscosity, and has also been characterized by viscosity, diffusion-ordered NMR spectroscopy, dynamic light scattering, and atomic force microscopy measurements. Furthermore, the polymer is responsive to electrostimulus as viologen is electroactive, which was studied by cyclic voltammetry. This study represents a proof-of-principle as the polymer can potentially be applied as a self-healing and degradable polymeric material.

[Socio-ecological risk analysis framework coupled with ecosystem services]. / 耦合生态系统服务的社会生态风险分析框架.

The strong coupling between society and ecosystem makes socio-ecological risks become the main object of risk management. As the link between ecological and social processes, ecosystem services (ESs) are the core variable in deconstructing the social-ecological risks and the crucial point in resolving the risks. We explored the concept and the internal formation mechanisms of socio-ecological risk combining ESs, and further put the cascade logic and evolution process of "real risk-risk perception-risk behavior". Based on driver-pressure-state-impact-response framework (DPSIR), we proposed a framework for analyzing socio-ecological risk, and expanded the content and methodology system of research and management practices related to socio-ecological risks. We proposed that socio-ecological risk research coupled with ESs should focus on: 1) exploring the transmission mechanism between ecosystem processes, ecosystem services, and human well-being; 2) exploring the response mechanism of social subject behavior and its impacts on ecosystem services and human well-being; 3) construction of a multi-scale assessment model for social ecological risks coupled with ESs. The socio-ecological risk analysis framework for coupled ecosystem services was based on the mutual feedback between human and nature to explore the logic of risk formation, evolution, and governance, which could provide ideas for clarifying the deep meaning of ecological problems and selecting pathways to resolve socio-ecological risks.

Simple cyclic chalcone dye with multiple optical functions: Piezochromism and lysosomes staining.

Both artificially synthesized and naturally occurring cyclic chalcones have been widely studied for their excellent biological activities. However, research on its photophysical properties is still limited. In the present study, we designed and synthesized a small molecule fluorescent dye based on the ICT effect, using dimethylamino as the electron-donating group and carbonyl as the electron withdrawing group, and investigated its photophysical properties in depth. Although YB is a simple small molecule, it exhibits significant piezochromic properties. The fluorescence of YB can change from green to yellow through grinding. After solvent fumigation, the fluorescence reverts to green. Furthermore, YB was used successfully in the lysosomal targeting. This study expands the research on the photophysical properties of cyclic chalcone and give richness to application of cyclic chalcone compounds.

Pagoda[n]arenes (n = 4, 5): Extremely Strong Binders for the Tropylium Cation.

Herein, host-guest complexation between pagoda[n]arenes (n = 4, P4; n = 5, P5) and tropylium cation (G) was investigated in detail. It was found that both P4 and P5 showed surprisingly strong binding affinities toward the tropylium cation with association constants of more than 107 M-1 for the 1:1 host-guest complexes. The theoretical calculations showed different host-guest complexion ways for complexes G@P4 and G@P5 and the strong π···π interactions and multiple C-H···π interactions play a very important role in the formation of these stable complexes, respectively. Moreover, the switchable processes of guest binding and release in the complexes can be effectively controlled by redox stimuli, and they can be also visible by the color and fluorescence changes.

Monitoring intracellular pH using a hemicyanine-based ratiometric fluorescent probe.

Monitoring intracellular pH using ratiometric fluorescent probes can provide further insights into various biological processes including many diseases. Although ratiometric fluorescent probes with dual emission can efficiently exclude interferences (probe concentration, instrumental efficiency, and environmental conditions) compared with traditional off-on fluorescent probes, development of pH-responsive fluorescent probes with dual emission remains relatively unexplored and challenging. Herein we reported a new hemicyanine-based ratiometric fluorescent probe 1 with a hydroxyl group. The probe 1 exhibits dual emission and shows a real-time and selective fluorescence response to micro-environmental pH conditions in a range of 6.0 âˆ¼ 8.0. Further studies revealed that 1 could exclusively enter and accumulate into mitochondria and monitor the pH micro-environmental conditions through fluorescence imaging in HepG2 cells. We suggest that this probe might be used as a probe to elucidate the role of pH in many physiological processes.

The coumarin-pyrazole dye for detection of hydrogen sulfide in cells.

Fluorescent probes for H2S are often interfered by other thiols. In this work, a coumarin-pyrazole dye with 2,4-dinitrosulfonyl group was designed for the detection of H2S. The probe exhibits weak fluorescence in water due to the photo induced electron transfer (PET) by 2,4-dinitrosulfonyl. After the sulfonyl group is cleaved off by H2S, strong fluorescence appears. The probe can specifically detect H2S without being interfered by other biological thiols, and shows a wide applicable pH range, low detection and wide detection range. The excellent detection properties of the probe can also be used to detect endogenous and exogenous H2S in cells. In addition, the probes can be made into portable test paper for the detection of H2S in solutions and can detect H2S in different water samples.

A coumarin-based fluorescent probe: single-wavelength excitation, discrimination of Cys/Hcy and GSH by naked eyes.

Biothiols mainly include cysteine (Cys), homocysteine (Hcy) and glutathione (GSH), which play an important role in life activities and abnormal changes in their concentrations are closely related to certain diseases. Therefore, the quantitative tracking and analysis of biothiols in living organisms has become a hot research topic in recent years. In this work, a coumarin-based fluorescent probe COUN was designed and synthesized for the comparable color recognition of Cys/Hcy and GSH by introducing the phenylethynyl group as the recognition site of biothiols, which showed significant fluorescence enhancement and green fluorescence under the UV light at 365 nm. The probe specifically recognized Hcy, showing 40-fold fluorescence enhancement and strong green fluorescence at 492 nm. Moreover, there was a good linear relationship between the fluorescence intensity of the probe and certain concentrations of Cys/Hcy and GSH, with detection limits of 36.6 nM, 86.4 nM, and 174 nM, respectively. The recognition mechanism of COUN to distinguish Cys/Hcy and GSH was studied by TDDFT calculations. More importantly, COUN was successfully used for imaging biothiols in living cells. The results showed that this probe could provide an effective contribution to the understanding of the role of biothiols, especially Hcy.

Coumarin-cyanine hybrid: A ratiometric fluorescent probe for accurate detection of peroxynitrite in mitochondria.

There is an urgent need to develop highly sensitive and selective fluorescence probes for ONOO- in mitochondria. Herein, we reported a ratiometric fluorescent probe COUS with coumarin-cyanine hybrid as fluorophore and C = C bonds as reaction sites of ONOO-. The probe COUS was sensitive and selective to ONOO-, and had a large fluorescence emission shift (239 nm) as well as a low detection limit (41.88 nM). Moreover, COUS showed the mitochondrial targeting ability, and the targeting moiety could dissociate from the probe when reacting with ONOO-, which enabled COUS to accurately detect ONOO- in mitochondria.

Highly selective and sensitive benzopyran-based fluorescent probes for imaging exogenous and endogenous peroxynitrite.

Peroxynitrite is widely present in organisms and closely related to many pathophysiological functions. Therefore, it is of great physiological significance to develop capable probes for detecting ONOO-. In this work, a novel fluorescent probe B-Ch was designed based on the intramolecular charge transfer (ICT) effect. By means of molecular engineering, the replacement from diethylamine group to hydroxyl group has improved the detection sensitivity of the probe. After the addition of ONOO-, the solution color and fluorescence showed noticeable changes, which were visible to the naked eye. The probe showed excellent advantages: visualization, good selectivity, low sensitivity (22.4 nM), good stability and biocompatibility, exogenous and endogenous imaging of ONOO- in HeLa cells.