A water-soluble fluorescent chemosensor based on Asp functionalized naphthalimide for successive detection Fe3+ and H2PO4−

The selective recognition of target ions in water is very important and the development of novel water-soluble chemosensor is still an intriguing challenge. Herein, a novel water-soluble fluorescent sensor based on aspartic acid (Asp) functionalized 1,8-naphthalimide derivative (Asp-NI) has been designed and synthesized. The sensor Asp-NI could dissolve in water and successively detect Fe3+ and H2PO4− in water solution with high selectivity and sensitivity. The detection limits are 4.97 × 10−7 mol/L for Fe3+ and 5.27 × 10−6 mol/L for H2PO4−. Other coexistent competitive metal ions (Hg2+, Ag+, Ca2+, Cu2+, Co2+, Ni2+, Cd2+, Pb2+, Zn2+, Cr3+, and Mg2+) showed no interference in the Fe3+ detection process. The sensor Asp-NI could act as a Fe3+ and H2PO4− controlled “On–Off–On” fluorescent switch. More interestingly, the Fe3+ induced fluorescence quenching process could be totally reversed by the addition of H2PO4−, this “On–Off–On” switching process could be repeated several times with little fluorescence loss. Notably, the actual usage of sensor Asp-NI was further demonstrated by test kits.

Active control of an edge-mode-based plasmon-induced absorption sensor

We investigate the formation and evolution of plasmon-induced absorption (PIA) effect in a three-dimensional graphene waveguide structure. The PIA window is formed by near-field coupling of the graphene edge mode, the extremely destructive interference between the radiative mode and sub-radiative mode of graphene nanoribbons. The resonance intensity has a significant dependence on the coupling distance between the graphene nanoribbons. At the same time, it is particularly sensitive to the refractive index of the environment, which is promising for sensing devices. In addition, the resonant wavelength can be actively controlled by changing the Fermi energy of graphene. Moreover, it can be seen that the group time delay of the PIA window reaches -0.28  ps, which is a good candidate for ultrafast light application. Finally, additional graphene nanoribbons can also form a double-channel PIA window. Our work may provide an excellent platform for controlling the optical transmission of highly integrated plasmonic components.

Rapid detection and subtyping of human papillomaviruses in condyloma acuminatum using loop-mediated isothermal amplification with hydroxynaphthol blue dye

Objective Condyloma acuminatum (CA) is a common, viral, sexually transmitted disease worldwide. Human papillomavirus (HPV) genotyping has important clinical implications for the treatment of CA. We developed a loop-mediated isothermal amplification (LAMP) method for the detection of HPV. Methods We collected 294 cervical scrape samples, including 30 HPV-6-positive, 30 HPV-11-positive, 22 HPV-16-positive, 20 HPV-42-positve, 30 HPV-43-positive, 20 HPV-44-positive and 142 HPV-negative samples. Tissues from 40 patients with a pathological diagnosis of CA were paraffin-embedded and analyzed by LAMP and Luminex. Hydroxynaphthol blue (HNB) and electrophoresis were used to detect the results of LAMP. Results LAMP and Luminex systems were compared in detecting six subtypes of HPV. LAMP reactions were specific for each subtype. The sensitivity of LAMP for HPV-6, as determined by the HNB indicator assay, was 1000 copies/tube. The kappa value between the two methods was 0.98 (HPV-6), 0.94 (HPV-11), 0.89 (HPV-43), 0.87 (HPV-42) 0.79 (HPV-16) and 0.68 (HPV-44). Among the 142 HPV-negative samples determined by the Luminex assay, HPV-6 was detected in eight and HPV-11 in one by LAMP. Among the 40 CA samples, the results of LAMP and Luminex were in agreement in 38 (95%). Conclusion The results of this study indicated that the LAMP assay with HNB is superior to the Luminex method in terms of sensitivity and specificity. The specificity of LAMP was 100% and the sensitivity of LAMP was 1000 copies/tube using HNB. LAMP is therefore a useful, quick and accurate method for the clinical diagnosis of HPV subtypes.

Tumor-associated macrophages as predictive biomarkers for postoperative adjuvant chemotherapy in patients with stage II colon cancer

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Background: For stage II colon cancer, the effect of postoperative adjuvant chemotherapy is still controversial. It is well known that tumor-associated macrophages (TAMs) play an important role in tumor progression. The aim of this study is to determine the effect of TAMs as predictor for adjuvant chemotherapy for stage II colon cancer. Methods: From July 2009 to June 2012, 521 patients with pathological stage II colon cancer were included. TAMs were detected using tissue microarray and immunohistochemistry (all TAMs detected by CD68; M2 subtype detected by CD206). The density of CD68+ TAMs, CD206+ TAMs and the ratio of CD206+ TAMs / CD68+ TAMs (CD206 / CD68 ratio) were calculated. The cut-off values were defined using X-Tile software. Results: High CD206+ TAMs density and high CD206 / CD68 ratio were significantly associated with reduced disease-free survival (DFS, P < 0.001 and P < 0.001, respectively) and overall survival (OS, P < 0.001 and P < 0.001, respectively). And CD206 / CD68 ratio had a better prognostic power. Furthermore, for patients with low CD206 / CD68 ratio, adjuvant chemotherapy made no benefit. But for high CD206 / CD68 ratio, adjuvant chemotherapy significantly improved DFS and OS (as shown in Table 1). In subgroup analysis, for T3 with high-risk factors or T4 tumors, CD206 / CD68 ratio was also a significant predictor for adjuvant chemotherapy (interaction P = 0.024 in DFS). Conclusions: For stage II colon cancer, CD206 / CD68 ratio was a good prognostic and predictive biomarker for adjuvant chemotherapy. Together with clinicopathological high-risk factors, it might facilitate patient counselling and individualise management. [Table: see text]

Pollutants identification of ambient aerosols by two types of aerosol mass spectrometers over southeast coastal area, China

Two different aerosol mass spectrometers, Aerodyne Aerosol Mass Spectrometer (AMS) and Single Particle Aerosol Mass Spectrometer (SPAMS) were deployed to identify the aerosol pollutants over Xiamen, representing the coastal urban area. Five obvious processes were classified during the whole observation period. Organics and sulfate were the dominant components in ambient aerosols over Xiamen. Most of the particles were in the size range of 0.2-1.0μm, accounting for over 97% of the total particles measured by both instruments. Organics, as well as sulfate, measured by AMS were in good correlation with measured by SPAMS. However, high concentration of NH₄⁺ was obtained by AMS, while extremely low value of NH₄⁺ was detected by SPAMS. Contrarily, high particle number counts of NO₃^- and Cl^- were given by SPAMS while low concentrations of NO₃^- and Cl^- were measured by AMS. The variations of POA and SOA obtained from SPAMS during event 1 and event 2 were in accordance with the analysis of HOA and OOA given by AMS, suggesting that both of AMS and SPAMS can well identify the organic clusters of aerosol particles. Overestimate or underestimate of the aerosol sources and acidity would be present in some circumstances when the measurement results were used to analyze the aerosol properties, because of the detection loss of some species for both instruments.

Reconstruction of atmospheric trace metals pollution in Southwest China using sediments from a large and deep alpine lake: Historical trends, sources and sediment focusing

Atmospheric pollution, one of the leading environmental problems in South and East Asia, and its impact on the terrestrial environmental quality remain poorly understood particularly in alpine areas where both historical and present-day mining and smelting operations might leave an imprint. Here, we reconstructed atmospheric trace metals pollution during the past century using core sediments from a large and deep alpine lake in Southwest China. The implication of in lake and/or in watershed sediment focusing in pollution quantification is discussed by analyzing 15 sediment cores. Factor analysis and enrichment factor indicated Cd, Pb and Sb as the typical pollutants. Distinct peaks of Pb and Sb pollution were observed around the 1920s, but little Pb pollution was detected in recent decades, different from other studies in similar regions. Cadmium pollution was observed until the mid-1980s synchronized with Sb. The distinctive variations in atmospheric trace metal pollution process in Southwest China highlight the regional and sub-regional sources of metal pollutants, which should be primarily attributed to non-ferrous metal smelting emissions. Both natural and anthropogenic metals showed wide concentration ranges though exhibited similar temporal trends in the 15 cores. Spatial variations of anthropogenic metals were influenced by the in-watershed pollutants remobilization, whereas, natural metals were regulated by the detrital materials in the sub-basin. In-lake sediment focusing had little influence on the spatial distributions of all metals, different from the traditional sediment focusing pattern observed in small lakes. Anthropogenic Cd accumulation in sediments ranged from 1.5 to 10.1mgm^-2 in a specific core with an average of 6.5mgm^-2 for the entire lake, highlighting that a reliable whole-lake pollutant budget requires an analysis of multiple cores. Our study suggests that the management of aquatic ecosystem health should take the remobilization of in-watershed stored pollutants into consideration especially under increasing human perturbation.

Silencing homeobox C6 inhibits colorectal cancer cell proliferation

Homeobox C6 (HOXC6), a member of the homeobox family that encodes highly conserved transcription factors, plays a vital role in various carcinomas. In this study, we used a tissue microarray (TMA) consisting of 462 CRC samples to demonstrate that HOXC6 is more abundantly expressed in colorectal cancer (CRC) tissues than adjacent normal mucosa. Clinicopathological data indicated that higher HOXC6 expression correlated with poor overall survival and was associated with primary tumor location in the right colon, primary tumor (pT) stage 3/4 and primary node (pN) stage 1/2. Multivariate analysis showed that high HOXC6 expression was an independent risk factor for poor CRC patient prognosis. HOXC6 downregulation via lentivirus-mediated expression of HOXC6-targeting shRNA reduced HCT116 cell viability and colony formation in vitro, and reduced growth of subcutaneous xenografts in nude mouse. HOXC6 thus appears to promote CRC cell proliferation and tumorigenesis through autophagy inhibition and mTOR pathway activation.

Competition of cation–π and exo-wall π–π interactions: a novel approach to achieve ultrasensitive response

A novel approach to achieve ultrasensitive response was successfully developed by rationally introducing the competition between cation–π and exo-wall π–π interactions into a pillar[5]arene-based supramolecular organogel (P5N-OG).

A cyanide-triggered hydrogen-bond-breaking deprotonation mechanism: fluorescent detection of cyanide using a thioacetohydrazone-functionalized bispillar[5]arene

Bispillar[5]arene-based fluorescent sensor was used for fluorescent detection of cyanide anions through deprotonation accompanied by intermolecular hydrogen bond breakage.

A novel water soluble pillar[5]arene and phenazine derivative self-assembled pseudorotaxane sensor for the selective detection of Hg2+ and Ag+ with high selectivity and sensitivity

A bifunctional supramolecular pseudorotaxane chemosensor (G-WAP) based on pillar[5]arene and phenazine imidazole was constructed, which could detect Hg²⁺ and Ag⁺ in water.

A novel supramolecular AIE gel acts as a multi-analyte sensor array

Supramolecular gelator WJ could form a stable supramolecular organogel (WJG) with strong aggregation-induced emission (AIE). Utilizing the AIE gel, we successfully developed a multi-analyte sensor array which could accurately identify CN⁻, Al³⁺, and Fe³⁺ and l-Cys.

Changes in structural characteristics and metal speciation for biochar exposure in typic udic ferrisols

Recent studies on biochars confirmed their potential benefits in improving soil fertility and sequestrating contaminants. However, little information on the changes in structural characteristics and metal speciation of biochars after exposure to soils is currently available. The aim of this study was to use double experimental bags to study the transformation of ozonized biochars derived from poultry manure and drying sludge (denoted PB and SB, respectively) in typic udic ferrisols. The carbon and sulfur functional groups and chemical characteristics of the biochars were determined using spectroscopic techniques, such as Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and near-edge X-ray absorption fine structure spectroscopy spectroscopy, combined with chemical extractions. Metal species were characterized using Cu K-edge X-ray absorption near-edge structure and chemical sequential fractionation schemes. The results showed that the potential changes in structural characteristics and metal species of biochars in soil were highly dependent on the composition of the biochars. PB comprised highly aromatic and chemically stable C, whereas SB contained a substantial amount of easily degradable C. Oxygen-containing groups slightly increased after incubation in the soil with either 60% water holding capacity (WHC) or flooding for 3 months. Sulfur in the biochars was predominantly inorganic S. Minerals such as K, Na, Mg, and S were mobilized from the biochars, accounting for 5-55% depending on the properties and sources of the element. Both PB and SB contained high concentrations of Cu and Zn. CuO in PB dissolved within 3 months, whereas CuS in both PB and SB was partly oxidized in the soil with 60% WHC for 9 months and adsorbed to the organic phase. Zn had relatively high mobility in both biochars, resulting in its vertical migration into soils.

A bis-naphthalimide functionalized pillar[5]arene-based supramolecular π-gel acts as a multi-stimuli-responsive material

A novel approach for the design of multi-stimuli-responsive supramolecular functional materials was successfully developed by introducing the competition of π–π stacking and cation–π interactions into a pillar[5]arene-based supramolecular π-gel (MP5-G).

Highly selective and sensitive chemosensor based on 2,3-diaminophenazine hydrochloride for the detection of cyanide in pure water and its application in plant seed samples

A 2,3-diaminophenazine hydrochloride (Q1) shows a ultrasensitive visible and fluorescence response for cyanide in pure water via hydrogen bonding.

A multi-stimuli responsive metallosupramolecular polypseudorotaxane gel constructed by self-assembly of a pillar[5]arene-based pseudo[3]rotaxane via zinc ion coordination and its application for highly sensitive fluorescence recognition of metal ions

A novel pillar[5]arene-based metallosupramolecular polypseudorotaxane gel has been successfully prepared.

Tri-pillar[5]arene-based multi-stimuli-responsive supramolecular polymers for fluorescence detection and separation of Hg2+

A novel tri-pillar[5]arene based supramolecular polymer (JP5G) shows multiple stimuli-response properties and could detect and remove Hg²⁺ from aqueous solution.

Novel 2-(hydroxy)-naphthyl imino functionalized pillar[5]arene: a highly efficient supramolecular sensor for tandem fluorescence detection of Fe3+ and F− and the facile separation of Fe3+

A novel pillar[5]arene-based supramolecular sensor (AP5N) for tandem fluorescence detection of Fe³⁺ and F⁻ was successfully prepared. Interestingly, the sensor AP5N shows excellent facile separation property for Fe³⁺.