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Previous studies have linked exposure to light at night (LAN) with various health outcomes, but evidence is limited for the LAN-obesity association. Thestudy analysed data from 24,845 participants of the 33 Communities Chinese Health Study and obesity (BMI ≥28 kg/m2) was defined according to the Working Group on Obesity in China. The Global Radiance Calibrated Nighttime Lights data were used to estimate participants' LAN exposure. The mixed-effect regression models examined the LAN-BMI and LAN-obesity association. We found that higher LAN exposure was significantly associated with greater BMI and higher risk of obesity. Changes of BMI and the odds ratios (ORs) of obesity and 95% confidence intervals (CIs) for 2nd, 3rd, and 4th against the 1st quartile of LAN exposure were 0.363 (0.208, 0.519), 0.364 (0.211, 0.516) and 0.217 (0.051, 0.383); 1.228 (1.099, 1.371), 1.356 (1.196, 1.538) and 1.269 (1.124, 1.433), respectively. Age and regular exercise showed significant modification effects on the LAN-obesity association. [ABSTRACT FROM AUTHOR]

Background: The accumulation of single nucleotide variants (SNVs) and the emergence of neoantigens can affect tumour proliferation and the immune microenvironment. However, the SNV-related immune microenvironment characteristics and key genes involved in hepatocellular carcinoma (HCC) are still unclear. We aimed to evaluate differences in the SNV-related immune microenvironment, construct a prognostic model and validate the key genes in vitro. Methods: The categories of samples were defined by the expression of SNV score-related genes to evaluate the differences in mutational features, immune environment and prognosis. The survival model was constructed with survival-associated genes and verified in two independent test datasets. RCAN2, the key gene screened out for biofunction, was validated in vitro. Results: IC2, among the three integrated clusters (IC1, IC2, IC3) classified by the 82 SNV score-related genes, was distinct from the rest in SNV score and immune cell infiltration, showing a better prognosis. Seven prognostic markers, HTRA3, GGT5, RCAN2, LGALS3, CXCL1, CLEC3B, and CTHRC1, were screened to construct a prognostic model. The survival model distinguished high-risk patients with poor prognoses in three independent datasets (log-rank P < 0.0001, 0.011, and 0.0068, respectively) with acceptable sensitivity and specificity. RCAN2 was inversely correlated with NK cell infiltration, and knockdown of RCAN2 promoted proliferation in HCC. Conclusions: This study revealed the characteristics of the HCC SNV-associated subgroup and screened seven latent markers for their accuracy of prognosis. Additionally, RCAN2 was preliminarily proven to influence proliferation in HCC and it had a close relationship with NK cell infiltration in vitro. With the capability to predict HCC outcomes, the model constructed with seven key differentially expressed genes offers new insights into individual therapy. [ABSTRACT FROM AUTHOR]

This study investigates the mediating role of parental dyadic coping in the impact of parenting stress on marital adjustment, specifically focusing on fathers and mothers as distinct groups within Chinese families with children aged 0–6 years. A total of 632 parents who met the inclusion and exclusion criteria agreed to participate, but only 604 couples completed the questionnaire. Utilizing the Actor-Partner Interdependence Model (APIM) and the Actor-Partner Interdependence Mediation Model (APIMeM), our findings reveal that both fathers’ and mothers’ parenting stress significantly influences their own marital adjustment, with dyadic coping partially mediating this relationship. Conversely, in terms of partner effects, only mothers’ parenting stress affects fathers’ marital adjustment, which is mediated by dyadic coping between both parents. Moreover, within the APIMeM model, it was found that the variable “whether the mother worked or not” exhibited a statistically significant impact on maternal parenting stress. These findings imply that couples aiming to enhance their marital adjustment in a favorable direction should be attentive to both paternal and maternal parenting stress levels and encourage collaborative efforts in coping with stress-related consequences. Additionally, it is crucial to provide more employment opportunities and financial security for mothers in China as a means of alleviating their parenting stress and ultimately fostering positive marital adjustment. [ABSTRACT FROM AUTHOR]

This study explored interactive interface design for writing practice, feedback, and grading in Chinese character learning systems. In the experiment, 30 novice Chinese learners were invited to perform designated learning tasks on two different learning systems. Learning times and outcomes were measured. The results indicated that improvement of interactive design had positive effects on learning performance, and the participants preferred the interactive design of the newer system. Then, a total of 37 Chinese learners of different proficiencies were invited to complete a survey on their satisfaction toward the interactive design of the new system. The results revealed no significant differences in satisfaction levels across Chinese learners regardless of proficiency; moreover, all participants agreed that the interactive design of the new system benefited their learning. According to the results, improvements in interactive designs can increase learning performance when studying Chinese characters. The results can also serve as interactive design guidelines for future Chinese character learning systems. [ABSTRACT FROM AUTHOR]

The fluorescence of functional dyes was generally quenched in aqueous solution, which hindered their application in water‐bearing detections. In this work, a novel strategy based on host‐guest interaction was provided for the purpose of fluorescence enhancement in aqueous solution and cell imaging. Three adamantane‐modified fluorescent dyes (Coum‐Ad, NP‐Ad, NR‐Ad) with coumarin, 1,8‐naphthalimide and Nile Red as fluorophores were initially designed and prepared. The ((adamantan‐1‐yl)methyl)amino group, as the auxochrome of those dyes, complexed with methylated β‐cyclodextrin (M‐β‐CD) via supramolecular interaction, and then fluorescent supramolecular nanoparticles (FSNPs) were formed by self‐assembly in water. The inclusion equilibrium constant (K) could be as high as 3.94×104 M−1. With the addition of M‐β‐CD, fluorescence quantum yields of these dyes were separately improved to 69.8 %, 32.9 % and 41.3 %. Inspired by the above satisfactory results, six adamantane‐modified probes organelle‐NPAds with organelle‐targeting capability were further obtained. As the formation of hydrogen bonds between organelle‐NPAd2 and M‐β‐CD verified by theoretical calculation, K of organelle‐NPAd2 (5.13×104 M−1~4.53×105 M−1) with M‐β‐CD was higher than that of organelle‐NPAd1 (1.15×104 M−1~3.66×104 M−1) and their fluorescence quantum yields increased to 32.8 %~83.6 % in aqueous solution. In addition, fluorescence enhancement was realized in cell imaging with the addition of M‐β‐CD. [ABSTRACT FROM AUTHOR]

Purpose: We aimed to investigate whether parental and siblings' sugar-sweetened beverage (SSB) intake had prospective impact on children's SSB consumption, and the potential sex difference in these associations. Methods: This study included a total of 904 children and their parents enrolled from 2004 to 2011 China Health and Nutrition Survey (CHNS) cohort study. SSB consumption information was estimated using a short dietary questionnaire and total energy intake was assessed with three-day 24-h dietary assessments at recruitment and follow-up surveys. Multivariate logistic or linear regression analyses were used to assess the association for SSB consumption between parents, siblings and children after adjusting for age, body mass index (BMI) z-score, household income and parental educational level. Results: In this study, a majority (87.6%) of children consumed SSB. Among them, the median consumption of SSB was 70.3 ml/day per capita and 205.4 ml/day per consumer. Parental SSB consumption was relevant to children's SSB consumption, and this association was more pronounced in boys than in girls. Meanwhile, fathers seemed to have a stronger impact on whether children consume SSB than mothers which was reflected by lower P and higher OR. Additionally, children's SSB intake was prospectively associated with their older siblings' SSB consumption (Pfor trend < 0.03). Conclusions: Parental and older siblings' SSB consumption was relevant to children's SSB intake. Particularly, boys were more susceptible to parental impact than girls, and fathers seemed to have a greater influence on children than mothers. [ABSTRACT FROM AUTHOR]

Objective To investigate the relationship between the intake of vegetables and fruits and the composition and diversity of gut microbiota during the first trimester of pregnancy in Chengdu. Methods In total 104 early pregnant women in Chengdu were enrolled in this study. Dietary frequency questionnaire was used to collect the intake of vegetables and fruits. According to the median intake of vegetables and fruits, the early pregnant women were divided into high intake group and low intake group. The intestinal microflora of fecal samples of early pregnant women was detected by 16S rRNA high-throughput sequencing, and the differences of intestinal microflora between groups were compared. Multiple linear regression was used to explore the relationship between vegetable and fruit intake and intestinal flora in early pregnant women. Results The median intake of vegetables and fruits in early pregnant women was 90.0 g/d and 200.0 g/d, respectively. There was no significant difference in intestinal microflora α and β diversity between high and low intake of vegetables and fruits in early pregnancy. LEfSe analysis showed that the relative abundance of multiple intestinal microflorae in early pregnant women was significantly different between the groups with high and low intake of vegetables and fruits. Multiple linear regression analysis showed that after adjusting age, pre-pregnancy body mass index, and energy intake, early pregnant women's vegetable intake was directly proportional to the relative abundance of Eubacterium siraeum group (β=0.007, P=0.012), inversely proportional to the relative abundance of Bacteroides (β=-0.167, P=0.023), and fruit intake was proportional to the relative abundance of Ruminococcus gnavus group (β=0.004, P=0.034), inversely proportional to the relative abundance of Agathobacter (β=0.004, P=0.044). Conclusion The intake of vegetables and fruits in early pregnancy leads to the change of relative abundance of intestinal flora. This study provides a new scientific basis for dietary regulation of gut microbiota during pregnancy. [ABSTRACT FROM AUTHOR]

Lignin is an important secondary metabolite that maintains the mechanical strength of horticultural plants and enhances their ability to respond to external environmental changes such as biotic and abiotic stresses. However, excessive accumulation of lignin can lead to lignification of horticultural products, reducing their taste quality and nutritional value. Therefore, the lignin content of horticultural products needs to be controlled at a reasonable level, and studying and regulating lignin metabolism is very meaningful work. This article focuses on the synthesis, accumulation, and regulation of lignin in horticultural crops in recent years, provides a systematic analysis of its molecular mechanism and application prospects, and sheds insights into the directions that need further research in the future. This article provides an important basis for the regulation of lignin accumulation and lignification in horticultural crops and proposes new ideas for improving the quality of horticultural crops. [ABSTRACT FROM AUTHOR]

A series of viscosity probes targeting different organelles were obtained using a single hemicyanine dye as the matrix structure. Specifically, probes 1a–d were obtained by introducing four amines (6-amino-2H-chromen-2-one, N-(2-aminoethyl)-4-methylbenzenesulfonamide, dodecan-1-amine and N,N diphenylbenzene-1,4-diamine) into the indole hemicyanine dye of the carboxylic acid with a D–π-A structure. Their maximum absorption wavelengths were in the range 570–586 nm and they had relatively large molar absorption coefficients, while their maximum emission wavelengths in the red light region were in the range 596–611 nm. Moreover, their fluorescence intensity in glycerol was 35–184 times higher than that in phosphate buffer solution (PBS). The lg(Fl) and lg η of probes 1a–d showed good linearity with high correlation coefficients according to the Förster–Hoffman equation. In addition, cell staining experiments demonstrated that 1a–c could target lysosomes, endoplasmic reticulum and mitochondria, respectively. They could also undergo viscosity-detectable changes in the corresponding organelles under the action of the corresponding ion carriers. [ABSTRACT FROM AUTHOR]

Two chromenoquinoline-based fluorescent probes 1a-b have been synthesized and investigated. Photofading behaviors of compounds 1a-b showed that at least 89% absorption remained after 6 h irradiating, meanwhile, many of ions and amino acids had negligible impacts on their fluorescence intensity, which meant they had excellent photostability and selectivity. Probes 1a-b exhibited strong absorption and emission in organic solvents with large fluorescence quantum yields, even in water probe 1a still had a relatively large fluorescence quantum yield (20%). Combined with DFT calculation, the influence of alkylation on optical properties of 1b was elucidated. In addition, the fluorescence intensity of probe 1b with red emission enhanced by 5.4-fold and 5.3-fold after DNA and RNA added, and the fluorescence quantum yield increased from 3% to 17% and 14%, respectively, but the neutral molecule 1a had no response to nucleic acid. Furthermore, confocal microscopy imaging of probes 1a-b showed that 1a targeted lipid droplets while the methylated probe 1b to nucleus in living HeLa cells. The results indicated that the subcellular targeting zone could be changed by alkylation of nitrogen atom on chromenoquinoline-based conveniently, which provided a new idea for designing and synthesizing new subcellular labeled probes. [ABSTRACT FROM AUTHOR]

Polarity and viscosity, as important microenvironment parameters, play an essential role in cell metabolism. Therefore, 9-acridine carboxaldehyde reacted with cyano compounds to obtain polarity-sensitive probes 1a–b and viscosity-sensitive probes 1c–d. Among them, with the increase in solvent polarity, the maximum emission wavelength of acridine-dicyanoisophorone-based probe 1a red-shifted from 553 nm to 594 nm, the fluorescence quantum yield increased from 0.5% to 35.6%, and the fluorescence intensity enhanced 38 fold. The acridine-cyanofuranone based probe 1b also has a polarity response similar to 1a. Nevertheless, when the solution viscosity increased from 0.89 cP (100% water) to 856 cP (1% water), the fluorescence intensity of the acridine-tricyanodihydrofuran based probe 1c at 430 nm enhanced 5.6 times. The acridine-cyanobenzothiazole based probe 1d also had a viscosity response similar to 1c. In addition, probes 1a–b were used for further HeLa cell imaging experiments due to their good photostability and the results suggested that probe 1a could locate lipid droplets and probes 1b–c could stain lysosomes. Moreover, probes 1a–b could dynamically monitor the changes in intracellular polarity. [ABSTRACT FROM AUTHOR]

Although ozone exposure has neurological toxicity, it remains unclear whether it was associated with an increased risk of attention-deficit/hyperactivity disorders (ADHD) among childhood. We matched the four-year average ozone concentration with questionnaire data for 35,103 children aged 3–12 years from seven cities in Liaoning, China, 2012–2013. Using mixed-effect logistic regression models, we assessed the association of ozone concentration with multiple ADHD indicators using the Conners Abbreviated Symptom Questionnaire (C-ASQ), including explicit attention-deficit/hyperactivity symptoms (ADHD; score ≥15), attention-deficit/hyperactivity disorder tendencies (ADHD-T; 11 ≤ score ≤14), and attention-deficit/hyperactivity problems (ADHP; score ≥11). Results were also stratified by sociodemongraphics. After adjusting for covariates, we found that each interquartile range (IQR) increase in ozone concentration was associated with an increased risk of ADHD, ADHD-T, and ADHP (P < 0.001) with an odds ratio of 1.12 (95% confidence interval, 1.04–1.21), 1.08 (1.03–1.13), and 1.09 (1.05–1.14), respectively. Additionally, we found greater effect estimates in children who reported longer exercise time (vs those with limited exercise time) with odds ratio of 1.18 (1.07–1.31) vs 1.06 (0.96–1.17) for ADHD, 1.13 (1.06–1.21) vs 1.03 (0.96–1.10) for ADHD-T, and 1.15 (1.08–1.21) vs 1.04 (0.98–1.10) for ADHP. Non-breastfed children were also shown to be more vulnerable to ADHD with an odds ratio of 1.22 (1.09–1.36) compared with 1.06 (0.96–1.16) among the rest. Long-term ozone exposure may be associated with increased ADHD among children. Additional studies are needed to validate our findings and support policies and interventions to address this growing public health concern. [Display omitted] • Ozone was associated with children attention-deficit/hyperactivity disorders (ADHD). • Children with symptoms but not reaching the diagnostic criteria had similar results. • Non-breastfed children and those who exercise frequently are the most vulnerable. [ABSTRACT FROM AUTHOR]

As a special form of autophagy, mitophagy is a pivotal mechanism governing cellular metabolism and physiology. Viscosity monitoring is an important aspect for real-time visualization of the mitophagy process. Hence, the development of high-performance viscosity probes is crucial for investigating dynamic pathological processes related to mitophagy. This study presents the discovery of mitochondria near-infrared and aggregation-induced emission probes with neutral structure. Probes 1a - 1b were connected quinoline/naphthidine malononitrile and coumarin units with a double bond, the absorption maxima were at 433–471 nm; emission maxima were at 605–720 nm with large Stokes shifts of 170–279 nm in solvents of different polarity. As the environmental viscosity increases from 0.89 cP to 856 cP, the fluorescence intensity of probe 1a and probe 1b is enhanced by 418-fold and 769-fold, respectively, which due to the restricted rotation and inhibited twisted intramolecular charge transfer in high viscosity systems. In addition to excellent NIR, hypotoxicity, and mitochondrial targeting capabilities, probes 1a - 1b were successfully applied to detect changes in mitochondrial viscosity during starvation or rapamycin-induced mitophagy. These remarkable features make probes 1a - 1b as promising candidates for investigating dynamic pathological processes related to mitophagy with significant potential for biological applications. [Display omitted] • Two electroneutral, NIR and AIE probes with exhibit mitochondrial targeting abilily. • These probes nearly showed dramatic "OFF–ON" fluorescent response with viscosity increasing. • These probes can monitor the viscosity changes of starvation and drug-induced mitophagy in real time. [ABSTRACT FROM AUTHOR]

[Display omitted] • Probes 1a-b for detection of thiophenols by ESIPT mechanism were constructed with diethylcoumarin–salicylaldehyde units. • They showed large Stokes shift (greater than100 nm) and one of them displayed NIR-emitting (670 nm) when detecting thiophenols. • Probes 1a-b could form inclusion complexes with M-β-CD. • The presence of M-β-CD reduced the detection limits of probes 1a - b towards thiophenols. Thiophenol and its derivatives are compounds with high toxicity to organisms and environmental pollution, so it is necessary to detect the level of thiophenols in the environment and biological samples. The probes 1a-b were obtained by introducing the 2,4-dinitrophenyl ether group into diethylcoumarin–salicylaldehyde based compounds. And they can form host-guest compounds with methylated β-cyclodextrin (M-β-CD), the association constants of inclusion complexes are 49.2 M−1, 125 M−1 respectively. The fluorescence intensities of probes 1a-b at 600 nm (1a) and 670 nm (1b) increased significantly in thiophenols detection. Meanwhile, with the addition of M-β-CD, the hydrophobic cavity of M-β-CD significantly increased the fluorescence intensity of probes 1a-b , thus the detection limits of probes 1a-b to thiophenols were reduced from 410 nM, 365 nM to 62 nM, 33 nM respectively. Whereas, the good selectivity and short response time of probes 1a-b towards thiophenols was not affected in the presence of M-β-CD. Moreover, probes 1a-b were used for further water sample detection and HeLa cell imaging experiments due to their good response to thiophenols and the results suggested that probes 1a-b had the potential to detect the content of thiophenols in water samples and living cells. [ABSTRACT FROM AUTHOR]

In this paper, several novel nitrogen-containing heterocycle dyes 1a-c with large conjugated planar structures based on naphthyridine derivatives were designed and synthesized, which had excellent optical properties and biological applications. Optical test showed the maximum absorption wavelengths of 1a-c were in the range of 443–485 nm, while the maximum emission wavelengths located at 523–610 nm in difference solvents. Furthermore, they exhibited polarity related fluorescence intensity changes with high fluorescence quantum yields, even up to 88% (1a in THF). Moreover, the transient absorption spectra revealed the excited-state lifetime of dye 1a became shorter with the increase of solvent polarity. Density functional theory calculations are also used to help explain the effect of the polarity of solvents on their fluorescence properties. Interestingly, the dyes 1a-c were somewhat toxic to cancer cells, while had an obvious growth-promoting effect on normal cells. Additionally, 1a-c with excellent lipid droplet (LD) targeting could be used for long-term observation of targeted cellular lis) hysiological activity and further applied to dynamic monitoring of changes in LDs polarity stimulated by TLR4 activator (LPS) in living cells. Overall, the excellent optical properties and biocompatibility of 1a-c indicate that they can serve as fluorescent probes for biological applications, and the results have important implications for understanding the physiological functions of LDs, especially in terms of morphological and polar changes. [Display omitted] • The dibenzo[c,f] [2,7]naphthyridine skeleton have been first applied in the field of cell imaging. • Dyes 1a-c possess high fluorescence quantum yield and excellent polarity response. • Dyes 1a-c are somewhat toxic to cancer cells, while have a growth-promoting effect on normal cells. • Dyes 1a-c can sensitively target lipid droplets with a low concentration, and dynamically monitor their polarity changes. [ABSTRACT FROM AUTHOR]

As a key parameter affecting the biochemical reaction of cells, the change of polarity also affects some important biological processes of cells. However, there are very few polarity probes for Golgi apparatus. In this work, coumarin or 1,8-naphthalimide were chosen as the fluorophores for their excellent optical property. Based on the combination of amide and long carbon chain, three Golgi polarity probes with different emission regions were designed and synthesized. Among them, Golgi-Blue and Golgi-Green inherited the blue and green fluorescence of the parents, respectively; while after the introduction of dicyanoisophorone unit to the 1,8-naphthalimide, Golgi-Red achieved near infrared emission (700–750 nm). Moreover, the three probes were sensitive to the polarity of solution. Interestingly, the fluorescence of Golgi-Blue and Golgi-Green decreased whereas that of Golgi-Red first enhanced gradually and then weakened with the increase of polarity, which was caused by the configuration change of the ground and excited state to induce twisted intramolecular charge transfer (TICT) in 1,4-dioxane and elucidated by means of density functional theory. Cell experiments showed that the three probes could quickly and accurately target Golgi apparatus and monitor the changes of Golgi polarity. The results may help in the early diagnosis of polar-related diseases. [Display omitted] • Three coumarin or 1,8-naphthalimide derivatives were synthesized. • The three probes could rapidly target to the Golgi apparatus and test polarity. • The red polarity probe had the opposite property to the other two. • This work filled the gap in the blue and green channels of Golgi polarity probes. [ABSTRACT FROM AUTHOR]

A cyanobenzo[a]phenoxazine-based pH probe with pKa = 5.0 exhibits OFF–ON emission at 625–850 nm upon excitation at 600 nm in aqueous buffers. The in cellulo imaging experiments with HeLa cells indicate that the probe can serve as a lysosome-specific probe under red light excitation (633 nm) with near infrared emission (650–790 nm). [ABSTRACT FROM AUTHOR]

Three hydrogen sulfide (H 2 S) probes based on an azonia–cyanine skeleton were successfully designed and prepared. Probe 1a , containing 4-chloro-7-nitro-1,2,3-benzoxadiazole connected to the cyanine dye, had an emission at 660 nm that was enhanced 4.5-fold by the reduced photoinduced electron transfer process when reacting with H 2 S. Probes 1b and 1c were constructed from cyanine dyes with electron withdrawing 2,4-dinitrophenyl and 7-nitrobenzo[c] [1,2,5]oxadiazol-4-yl groups, respectively. Probes 1b and 1c gave off−on type responses with 169- and 17-fold fluorescent enhancements at 639 nm with H 2 S. Their emission properties were influenced by intramolecular hydrogen bonds and intramolecular charge transfer processes. The detection limits of probes 1a – 1c were calculated at 178, 121, and 9.6 nM, respectively. The intracellular imaging experiments with HeLa cells indicated probe 1a was a mitochondria-targeting H 2 S probe, while probes 1b and 1c were lysosome-targeting H 2 S probes. Image 1 • The cyanine dyes had possess different organelles targetablities with different drivatives. • OFF-ON fluorescent probes were designed based on the elimination and recovery of hydrogen bonds. • Three fluorescent probes all have good selectivity to hydrogen sulfide, and one probe has a lowest detection limit as 9.6 nM. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Five probes (1a-e) have excellent photo stability. • Four probes (1a-d) exhibit "OFF–ON" fluorescent responses towards nucleic acids. • Probe 1a can image mitochondrial nucleic acid. • Probe 1a was a low-toxic probe for live HeLa cells. Abstract Five cyanine dyes (1a-e) with azonia unit have been prepared by the reaction of pyrido[1,2−a]pyrimidinium ions and suitable aldehydes. Before further research, their photo and thermal stabilities were determined in the first place. At least 88% absorption remained after 5 h irradiating illustrated all of these dyes had excellent photo stability. Meanwhile, the decomposition temperature of dyes was around 200 °C which demonstrated they had good thermal stability. Therefore, the good photo and thermal stability made them possible to be probes. Subsequently, the optical properties of probes toward nucleic acids had been measured. TheirOFF–ON fluorescent responses (1a - d) towards nucleic acids were investigated. In addition, confocal microscopy imaging of probe 1a in live HeLa cells indicated that probe 1a could image mitochondrial nucleic acid. [ABSTRACT FROM AUTHOR]

To evaluate the lysosome targetability of different nitrogen-containing basicity groups, seven fluorescent probes based on phenoxazinium connected different nitrogen-containing basicity groups were prepared. Probe 8b containing N , N -dimethylphenyl, 8c containing N , N -diethylphenyl group and 8d containing quinolin-8-yl group exhibited obvious emission responses at 675 nm with pH ranging from 2.4 to 5.6, 3.4–7.6 and 1.8–4.2, and their calculated p K a were 3.99, 5.57 and 2.46 respectively. While probe 8a containing morphoyl group, probe 8e containing pyridine-4-yl, probe 8f containing pyridine-3-yl and probe 8g containing pyrimidine group showed no significant changes of emission intensity when pH changes from 2.0 to 8.0. Moreover, three probes 8b , 8c and 8d showed good selectivity for hydrogen ion. Fluorescent imaging experiments indicated that probes 8c and 8d were lysosome biomarkers for Ges-1 and HeLa cells. [ABSTRACT FROM AUTHOR]

In order to improve lysosome targetability of probes, fluorescent probes based on benzo[ a ]phenoxazine attaching different length oligoethyleneoxy chains were designed and prepared. Probes 2a – c containing N -pyridineium-3-yl exhibited almost ON-OFF near-infrared emission responses at 697–701 nm from pH 2.8 to 7.2, and the calculated p K a values of 2a – c were 4.90, 4.92 and 5.03 respectively. More importantly, fluorescent imaging experiments indicated that probes 2a – c were all lysosome biomarkers for Ges-1 and HeLa cells, which was because the introduction of oligoethyleneoxy groups improved the biocompatibility of probes, so that the probes 2a – c were better transported to lysosomes via the endocytosis pathway of the cells. Moreover, the probe 2a was selected as a representative, which not only showed good reversibility and selectivity, but used to successfully image lysosomal pH increases induced by chloroquine. [ABSTRACT FROM AUTHOR]

[Display omitted] • An aerobic denitrifying microbe, HITSZ-D1, was identified as Pseudomonas mendocina. • Strain D1 has extremely high denitrification efficiency and enzyme activities. • The environmental threshold of strain D1 is extensive. • Strain D1 efficiently metabolizes various nitrogen types without accumulating nitrite. A highly efficient aerobic denitrifying microbe was isolated from sewage sludge by using a denitrifier enrichment strategy based on decreasing carbon content. The microbe was identified as Pseudomonas mendocina HITSZ-D1 (hereafter, D1). Investigation of the conditions under which D1 grew and denitrified revealed that it performed good growth and nitrate removal performance under a wide range of conditions. In particular, D1 rapidly removed all types of inorganic nitrogen without accumulation of the intermediate products nitrite and nitrous oxide. Overall, D1 showed a total nitrogen removal efficiency >96% at a C/N ratio of 8. The biotransformation modes and fates of three typical types of inorganic nitrogen were also assessed. Moreover, D1 had significantly higher denitrification efficiency and enzyme activities than other aerobic denitrifying microbes (Paracoccus denitrificans , Pseudomonas aeruginosa , and Pseudomonas putida). These results suggest that D1 has great potential for treating wastewater containing high concentrations of nitrogen. [ABSTRACT FROM AUTHOR]

Two rosamine-based probes (1a–b) with pyronine-pyridinium skeleton were designed and prepared. Probe 1a bearing boron ester unit was oxidized and eliminated upon addition of hydrogen peroxide (H2O2), and the emission spectrum exhibited OFF–ON response accompanied by 33-fold fluorescent enhancement. In contrast, the fluorescence intensity of probe 1b enhanced 58 times after the dinitrophenyl ether part within the probe was removed by nucleophilic substitution with hydrosulfide (H2S). The design concept was based on the d-PET process in pyronine-pyridinium structures, and free 4-pyridinyl-substituted pyronine dye showing strong fluorescence was released followed by elimination. Furthermore, as biocompatible molecules, probes 1a–b have been successfully applied for imaging in live HeLa and Ges-1 cells, and all of them can serve as mitochondrial targetable probes in red channel for detecting independent species. [ABSTRACT FROM AUTHOR]

In this paper, a new compound ( 3 ) with pyronine-pyridine skeleton had a strong fluorescence at pH 5.0−9.0, while the emission turned off at pH = 1.0–2.0. It was a mitochondrial biomarker in cancer cells (KB, 4T1, HeLa) and normal cells (Ges-1, L929, WS1). Based on these above results, probe 1 with pyronine-pyridinium skeleton was further designed and prepared to detect nitroreductase (NTR). The nitrofuran group of probe 1 was reduced and eliminated upon addition of NTR and nicotinamide adenine dinucleotide (NADH) to produce compound 3 , and the d-PET process could be allowed in the pyronine-pyridinium structure of probe 1 but it was prohibited in the pyronine-pyridine skeleton of compound 3 after detection, hence probe 1 showed a nearly turn-on signal in red light region at 565–800 nm with emission maxima at 604 nm. The detection limit was calculated as low as 2.2 ng/mL. Furthermore, fluorescence imaging experiments with live HeLa and Ges-1 cells were performed, and probe 1 could serve as a mitochondrial targetable probe to detect nitroreductase in red channel. [ABSTRACT FROM AUTHOR]

The cyanine dye ( 1 ) with three arms of one chromenyl group and two indol groups was synthesized in this paper; and the proposed synthetic mechanism was also mentioned. It has excellent photostability compared to three typical cyanine dyes. Dye 1 gives high chemical activity and nearly turn-on fluorescent response towards hydrosulfide at 600–800 nm, it also has good selectivity towards hydrosulfide over other species; the detection reaction mechanism was proved by 1 H NMR analysis, and the emission responses was elucidated by time dependent density functional theory (TDDFT) calculation. The in cellular fluorescent imaging application of the dye 1 was successfully performed for the hydrosulfide imaging of HeLa cells. [ABSTRACT FROM AUTHOR]

Three phenoxazinium compounds attached with o -nitrophenyl ( 3a ), m -nitrophenyl ( 3b ) and p -nitrophenyl ( 3c ) groups were prepared, and the pH promoted emission spectra were used to evaluate the deprotonated-protonated equilibrium between phenoxazinium and phenoxazine. They showed nearly ON-OFF emission responses at 650–850 nm around pH 8.0–10.8, and the fluorescence related p K a s of 3a–c were 8.7, 9.2, and 8.9, respectively. Two phenoxazinium compounds attached with pyridinyl groups ( 7a–b ) were further prepared, the pH promoted emission spectra were influenced by both the deprotonated-protonated equilibrium between phenoxazinium and phenoxazine, and the equilibrium between pyridinyl group and pyridinumyl group. They exhibited more strong red and near-infrared emission at 600–850 nm, probe 7a gave p K a ,1 = 3.71 and p K a ,2 = 9.68, and that of probe 7b was 2.75. Moreover, the fluorescent imaging experiment indicated that probe 7a was a lysosome biomarker for V79 and HeLa cells. [ABSTRACT FROM AUTHOR]

The regulation of bacterial quorum sensing (QS) has been used to inhibit biofouling in wastewater treatment plants and the formation of biofilms. In contrast to traditional QS regulation strategies, this study aimed to obstruct the transmembrane transport process of QS signals to decrease their extracellular accumulation. Three phytochemicals, astragaloside IV, eugenol, and baicalin were selected, their effects on biofilm formation by Pseudomonas aeruginosa PA14 were studied, and the mechanisms determined. The inhibition efficiency of biofilm formation by 50 mg/L astragaloside IV, 1 mg/L eugenol, and 1 mg/L baicalin were 37%, 26%, and 26%, respectively. Confocal laser scanning microscopy and analysis of extracellular polymeric substances indicated that the three inhibitors affected the structure and composition of the biofilms. Furthermore, bacterial motility and a variety of QS-related virulence factors were suppressed by the inhibitor treatment due to changes in bacterial QS. Notably, the three inhibitors all decreased the extracellular concentration of the QS signaling molecule 3-oxo-C12-homoseine lactone by affecting the function of efflux pump MexAB-OprM. This indirectly interfered with the bacterial QS system and thus inhibited biofilm formation. In conclusion, this study revealed the inhibitory effects and inhibition mechanism of three phytochemicals on efflux pump and QS of P. aeruginosa and realized the inhibition on biofilm formation. We update the efflux pump inhibitor library and provide a new way for biofilm contamination control. [Display omitted] • Three extracts significantly affected the amount and structure of PA14 biofilm. • The QS-related virulence factor and motility of PA14 were inhibited by 3 extracts. • The expression of QS and efflux pump related genes were inhibited by 3 extracts. • Three extracts reduced the accumulation of extracellular 3-oxo-C12-HSL. [ABSTRACT FROM AUTHOR]

Hierarchical assembly of macromolecules has been central in creating complex nanostructures. In this work, polystyrene- block -poly (perfluorooctylethyl acrylates) (PS- b -PFOA) diblock copolymers were synthesized by reversible addition-fragmentation chain transfer (RAFT) polymerization and shown to assemble into hierarchical structures in bulk with the interplay of nanophase separation and crystallization. The molecular weights were determined by gel permeation chromatography (GPC) and 1 H NMR spectra. The phase-separated nanostructures of these block copolymers were investigated via small-angle X-ray scattering (SAXS) and wide-angle X-ray diffraction (WAXD) in reciprocal space and by transmission electron microscopy (TEM) in real space. The results showed that well-ordered lamellar morphologies were formed in the bulk of samples with volume fraction of PFOA ( f PFOA ) around 0.390–0.538. Within the PFOA layers, the side chains were found to further crystallize, forming crystalline layers with thicknesses about twice that of the length of fluorinated side-chains. The SAXS patterns from sheared samples further show that the orientation of crystalline layers was perpendicular to the lamellar layers formed by micro-phase separation. [ABSTRACT FROM AUTHOR]

A near-infrared fluorescent probe based on benzo[a]phenoxazine containing o -phenylenediamine group as reactive site was designed and synthesized. The titration experiment showed that the probe gave colorimetric response towards sodium nitrite with the absorption maxima at 630 nm and 542 nm in pH = 5.0 disodium hydrogen phosphate-citric acid buffers containing 30% DMSO; its emission was located in 590–820 nm with the 9.1-fold fluorescent enhancement under excitation at 580 nm. Moreover, the probe can detect nitrite quantitatively in a concentration range of 0.0–26.0 μM and the detection limit is as low as 45 nM. The salient features of this method are high sensitivity and selectivity, fast detection and low detection limit. Fluorescence confocal imaging experiments with V79 and HeLa cells indicate that the probe has the potential application in quantitative detection exogenous nitrite level for in cellular imaging. [ABSTRACT FROM AUTHOR]

In this paper, the design of a lysosome-targetable pH probe that has a fluorescent OFF (pH = 4) to ON (pH = 5–6) response is described to identify lysosomes in normal cells. The mechanism of photoinduced electron transfer with a fluorophore-based reaction (FBR-PET) was proposed. Benzo[ a ]phenoxazines with electro-donating aryl groups were selected, its (2,5-dimethoxyphenyl)imino-, (2-hydroxyphenyl)imino- and (2-hydroxy-5-methoxyphenyl)- imino-derivatives (probes 1a−c ) were prepared and their optical responses towards pH were evaluated; their fluorescence pH titration experiments gave regularly changes with the increasing electro-donating abilities at the linked aryl groups, the (2-hydroxy-5-methoxyphenyl)iminobenzo[ a ]phenoxazine (probe 1c ) exhibited a nearly OFF−ON response at 580–800 nm. All probes were reversible, and they showed excellent selectivity toward the proton over other competitive species. Fluorescence confocal images were performed with HeLa, KB cancer cells and V79 normal cells, probes 1a−c are all lysosome-targetable pH probes, and benzo[ a ]phenoxazine with (2-hydroxy-5-methoxyphenyl)imino-group (probe 1c ) has potential applications in selective differentiation of normal cells from cancer cells. [ABSTRACT FROM AUTHOR]

As an important organelle, the main function of the Golgi apparatus is to further modify and deliver proteins synthesized by the endoplasmic reticulum (ER). Dyshomeostasis of the Golgi appartus can cause many serious diseases. Therefore, monitoring the normal functioning of the Golgi appartus is particularly important. However, only a few commercially Golgi markers are available till now. In this work, three 1,8-naphthalimide related Golgi markers (4a - c) with the combination of amide and long carbon chain were designed and synthesized, their maximum emission wavelengths could reach 500–575 nm with high fluorescence quantum yields. Moreover, they possessed low cytotoxicity (cell viabilities >82%). Cell experiments exhibited that dyes 4a - c could rapidly and accurately mark the Golgi apparatus. To discuss the origin of their targeting ability, compounds 5–7 with independent amide or long carbon chain were additionally prepared. With the separation of amide and long carbon chain in compound 5 – 7 , the targeting ability was lost. The experiments showed that the targeting ability of 4a - c resulted from the combination of amide and long carbon chain structure. Also, the results may provide a new idea for designing organelle markers. [Display omitted] • Synthesis of three 1,8-naphthalimide derivatives with the combination of amide and long carbon chain. • All three dyes can quickly locate in the Golgi apparatus and not located to other organelles. • All three dyes can image at a low concentration. • The Golgi targeting ability may be attributed to the combination of amide and long carbon chain structure. [ABSTRACT FROM AUTHOR]

In this paper, oxazolepyridine and coumarin units were combined to prepare cell membrane fluorescent probe (PM-A) through aldol condensation reaction. PM-A had long wavelength emission (665–739 nm), high molar extinction coefficient (around 3.14 × 104 M−1cm−1) and large Stokes shift (150–219 nm). The photo-stability test showed that PM-A had a high relative residual absorption (93%) after 6 h of continuous illumination. In addition, the supramolecular interaction between PM-A and β-cyclodextrin was evaluated and applied to cell imaging. Probe PM-A had no fluorescence in water, but had obvious fluorescence signal in β-cyclodextrin solution. With the addition of β-cyclodextrin (0–800 eq), the fluorescence quantum yield of PM-A increased from 0% to 45%. Laser confocal experiments showed that when only PM-A was added, the probe concentration needed to be 15 μM to image the cell membrane obviously. In sharp contrast, with the help of β-cyclodextrin solution, the concentration of probe PM-A only needed 0.5 μM to quick and high specificity image cell membranes. Moreover, PM-A had high photo-bleaching resistance and long retention time after adding β-cyclodextrin. These excellent properties of PM-A were of great significance to the study of cell membrane. [Display omitted] • A near-infrared fluorescent probe (PM-A) with oxazolepyridine and coumarin units was prepared for the imaging of cell membrane at 15 μM. • The supramolecular interaction between probe PM-A and β-cyclodextrin was evaluated. • Probe PM-A showed rapid and high specificity of cell membrane imaging at the concentration of 0.5 μM with the help of β-cyclodextrin. [ABSTRACT FROM AUTHOR]

[Display omitted] • β-CD promoted denitrification and mitigated intermediate products generation. • β-CD enhanced glucose metabolism to generate energy and electron for denitrification. • The electron generation, transfer, and utilization in bacteria were promoted by β-CD. • The bacterial peripheral iron was enriched due to β-CD stimulating the EPS secretion. • β-CD enhanced bacterial iron acquisition via regulated iron transmembrane transport. Denitrification is widely applied in wastewater treatment systems for nitrogen removal, but it is still disturbed by unsatisfactory efficiency, nitrite accumulation, and nitrous oxide emission. In this study, the presence of 0.5 mM β-cyclodextrin (β-CD), an oligosaccharide chemical compound, effectively promoted the nitrate reduction by Paracoccus denitrificans from 68.02% to 82.78% after 20 h of cultivation. Meanwhile, the exogenous addition of β-CD significantly up-regulated the expression of denitrification-related genes (narG , nirS , norB , and nosZ), and mitigated the accumulation of nitrite and nitrous oxide emission. Notably, different from traditional organic substances for enhancing denitrification, this study not only identified β-CD increased electron generation and ATP synthesis from glucose metabolism of P. denitrificans instead of being utilized as an external carbon source, but also observed the relative promotion of β-CD on electron transfer and denitrification were positively correlated with ambient iron concentration. The addition of β-CD stimulated bacterial EPS secretion and indirectly enriched peripheral iron, and simultaneously benefited the iron transmembrane transportation and intracellular iron concentration. Given the whole process of iron enrichment and transportation, β-CD was demonstrated to improve denitrification and electron transfer via promoting iron acquisition. This study first revealed the enhancement of β-CD on bio-denitrification via iron acquisition, which provided a novel basis for its application in nitrogen removal. [ABSTRACT FROM AUTHOR]

To improve self-targeting abilities towards organelles, four fluorescent dyes (1a-1d) were designed by connection of dicyanoisophorone to phenylpiperidinol (1a), naphthalenol (1b), indazole (1c) and pyrene (1d) unit with a double bond. Their absorption maxima were located at 423–517 nm; and emission maxima were at 565–682 nm with large Stokes shifts of 142–191 nm. Moreover, their fluorescence intensities increased 11–117 fold in glycerol compared to phosphate buffer solution, which might be due to the long excited state lifetimes (up to 1 ns) by transient absorption spectra. Furthermore, laser confocal experiments with HeLa cells proved that dyes 1a-1d were self-target fluorescent markers at 10–20 μM for lysosomes, endoplasmic reticulum, mitochondria and lipid droplets respectively; and they could be used for the fluorescent probes at 2 μM for viscosity detection within corresponding organelles by influence of ionophores. In addition, these dyes were able to detect viscosity changes in a Parkinson's disease model with PC-12 cells. [Display omitted] • Four Dicyanoisophorone derivatives can self-target multiple organelles. • These probes can detect viscosity change within corresponding organelles by influence of ionophores. • These dyes were able to detect viscosity changes in a Parkinson's disease model. [ABSTRACT FROM AUTHOR]

In this paper, phenoxazinium was used as a fluorophore for the design of pH probes by the photoinduced electron transfer (PET) mechanism. Phenoxazinium with an aliphatic morpholinyl group (probe 1a) gave increased emission at 665 nm with pH ranging from 7.4 to 4.4; meanwhile, the other one with an aromatic diethylaminophenyl group (probe 1b) gave nearly OFF–ON emission at 679 nm with pH ranging from 7.4 to 4.2. They both were reversible pH probes with good selectivity. Their optical properties, especially the PET mechanism, were illustrated by (TD)DFT theory. Fluorescence confocal imaging of probes 1a–b and a typical phenoxazinium dye (Oxazine 1) was also performed, and the results indicated that probes 1a–b are lysosome-targetable biomarkers. [ABSTRACT FROM AUTHOR]

Compared to the nitrogen-reaction based pH optical responsive compounds, oxygen-reaction related pH sensors have attracted less attention. In this paper, hemicyanine based pH probes are designed by establishing the equilibrium between phenolate and phenol, and their reversible absorption and emission responses towards pH are evaluated. The indolium–phenol based tetramethylene hemicyanine (1a) has colorimetric responses at 455 and 578 nm due to the protonating and deprotonating processes; its emission spectra shows ratiometric changes at 594 and 654 nm with large Stokes shifts under acidic (139 nm) and basic conditions (76 nm). The bromide substituent of the hemicyanine (1b) has a lower pKa value compared with unsubstituted hemicyanine (1a), which suggests that adjustable pKa can be achieved by the modification of electron withdrawing groups. The theoretical calculations based on the density functional theory (DFT) were also used to explain the optical properties. Moreover, the in cellulo fluorescence imaging shows that the hemicyanine (1a) can be used for the detection of intracellular pH levels. [ABSTRACT FROM AUTHOR]

Hydrogen sulfide has recently been identified as a biologically responsive species. The design and synthesis of fluorescence probes, which are constructed with Nile-red or Nile-blue fluorophores and a fluorescence-controllable dinitrophenyl group, for hydrogen sulfide are reported in this paper. The Nile-red-dinitrophenyl-ether-group-based probe ( 1a) is essentially non-fluorescent because of the inhibition of the photo-induced electron-transfer process; when the dinitrobenzene moiety is removed by nucleophilic substitution with the hydrosulfide anion, probe 1a is converted into hydroxy Nile red, eliciting a HS-induced fluorescence turn-on signal. Furthermore, probe 1a has high selectivity and sensitivity for the hydrosulfide anion, and its potential for biological applications was confirmed by using it for real-time fluorescence imaging of hydrogen sulfide in live HeLa cells. The Nile-blue-dinitrobenzene-based probe ( 1b) has gradually diminishing brightness in the red-emission channel with increased hydrogen-sulfide concentration. Thus, this paper reports a comparative study of Nile-red and Nile-blue-based hydrogen-sulfide probes. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Highlights: [•] A rosamine-based pH probe developed by a one-step synthesis. [•] An OFF–ON pH probe with 400-fold enhancement in the fluorescent signal. [•] A red-emitting lysosome-specific fluorescent probe. [Copyright &y& Elsevier]

[Display omitted] • The photooxidation of thiocarbonyl photosensitizers were further studied. • It provides a feasible way to solve the photosensitizer residues problem in small molecule level. • The heavy-atom-free photosensitizer 1a mitochondrial targeting ability was verified. Photodynamic therapy (PDT) has been successfully applied in clinical treatment several years. However, after finished treatment process the residual photosensitizer will spread throughout body, which forces patients stay in the dark room to avoid exposure in sunlight several weeks. Therefore, develop degradable photosensitizer could effectively eliminate this inconvenience. In the past, researchers have developed degradable photosensitizers based on supramolecular structure. In this study, we achieved the same effect in small molecule level. Three thiocarbonyl photosensitizers (PS) have high photogenerated 1O 2 quantum yield and can be photodegraded by laser irradiation within 15 min. And due to its high phototoxicity and low toxicity, thiocarbonyl PS still maintains its high phototoxicity. Especially, mitochondrial targeting PS 1a has better properties than many BODIPY or cyanine heavy-atom-free photosensitizers. It only needs 1 μM to reduce HeLa cell activity to 30%. Finally the thiocarbonyl PS provided a convenient way to solve the PS residue problem without sacrificing PDT efficiency. [ABSTRACT FROM AUTHOR]

New pH-activatable ratiometric fluorescent probes have been developed that have a coumarin structure attached to benzothiazole or indole units with one or two conjugated bonds. They have optical responses in acidic conditions. Probes with benzothiazole (1) and indole (2, 3) units have opposite responses to changes in pH, in terms of shifts in absorption and emission. Quantum chemical calculations with the B3LYP exchange functional provide insights into the differences in optical properties between 1 and 2/3. Probe 3 (7-diethylamino-3-[4-(3,3-dimethyl-3H-indol-2-yl)-buta-1,3-dienyl]-chromen-2-one) displayed a significant 122 nm red shift of the emission maximum; the new peak is located in the near-infrared region. In vitro assays demonstrate that probe 3 can be used in quantitative fluorescence imaging for the detection of intracellular pH distributions. In addition to the large Stokes shift, it has rapid responsivity, excellent cell permeability, and high selectivity. This study reveals that the conjugation of coumarin with benzothiazole or indole to form an intramolecular charge transfer (ICT) platform is an effective method to construct new fluorescent pH probes for acidic microenvironments. [ABSTRACT FROM AUTHOR]

Abstract: Aliphatic biothiols, including cysteine, homocysteine, and glutathione, are associated with a wide range of biological functions. Hence, the selective detection of intracellular thiols has significance for investigating cellular function. Ratiometric fluorescent probes are very useful in the biological sciences because they allow measurement at two emission wavelengths, providing a built-in correction for environmental effects. In this study, a benzoxazine–hemicyanine based probe (1) was synthesized and characterized. The probe shows quick colorimetric and ratiometric response toward biothiols in the presence of other biomolecules and it functions in a wide pH range exhibiting large shifts in both absorption and fluorescence spectra. The detection mechanism, which was induced by the addition of mercaptan toward the activated double bond in the probe, was verified using 1H NMR and mass spectrometry analysis. The photophysical properties changes that occurred upon the reaction of the probe were found to be induced by the variation of intermolecular charge transfer, which was confirmed by theoretical calculations based on density functional theory (DFT). The fluorescence imaging of intracellular thiols was also examined with excellent performance. [Copyright &y& Elsevier]

Abstract: A phenoxazinium-based compound (1) behaving as a near-infrared (NIR) fluorescent probe toward Zn2+ was designed and synthesized. It showed selective fluorescence enhancement with the introduction of Zn2+ in buffer aqueous solution. The probe 1 exhibited distinct red fluorescence and good stability under physiological pH. In addition, fluorescence imaging experiments of Zn2+ in KB living cells demonstrated its value of practical applications in biological systems. [Copyright &y& Elsevier]

Background: The development of abnormal involuntary movements or dyskinesia is a serious complication of L-3,4-dihydroxyphenylalanine (L-DOPA) therapy for Parkinson's disease (PD). Objective: To evaluate the correlation between dopamine transporter (DAT) regulated by L-DOPA and the pathogenesis of dyskinesia in PD rats. Methods: Thirty rats were used to establish the PD model by injecting 6-hydroxydopamine into the right medial forebrain bundle. The sham surgery rats (n = 4) received 4 μl of physiological saline. Then, 19 rats in which PD has been successfully induced were randomly assigned to the L-DOPA (20 mg/kg/day; n = 15) or model (saline; n = 4) group. After 4 weeks of treatment, 131I-N-(3-fluoropropyl)-2β-carbomethoxy-3 β-(4-iodophenyl)nortropane was injected into the rats, and images of DAT in the brain were acquired using a storage phosphor plate. The levels of DAT-specific radioactivity uptake in the bilateral corpora striata (left/right) were compared. Results: There was no difference in DAT-specific radioactivity uptake between the bilateral corpora striata in the sham surgery rats. The images were clear and symmetrically distributed in the corpora striata. In PD model rats, the DAT-specific radioactivity uptake decreased on the lesioned side and the ratios of uptake between the corpora striata were increased. Accumulation of the radioligand on the lesioned side was sparse. In the L-DOPA group, the average ratio values were significantly increased in dyskinetic rats and reduced in nondyskinetic rats. In addition, the differences between the bilateral corpora striata were reduced in nondyskinetic rats. Conclusion: L-DOPA was shown to downregulate DAT in some PD model rats. That process may be involved in the pathogenesis of dyskinesia. Copyright © 2011 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Abnormal mitochondrial viscosity could lead to diabetes and neurodegenerative diseases, therefore three probes 1a-c for monitoring the fluctuation of viscosity were designed and synthesized in this article. Probes 1a-c were composed of 1,8-naphthalimide derivatives and benzoxazole, benzothiophene or oxazole [4,5- b ] pyridine structure through carbon-carbon double bond connection, and their emission wavelengths increased sequentially (1a : 580 nm; 1b : 614 nm; 1c : 630 nm). The single bond between the nitrogen-containing heterocycle and the carbon-carbon double bond served as the viscosity response site. When the viscosity increased from 0.95 cP to 945 cP, the fluorescence intensity of probes 1a-c increased 18.67-fold, 20.34-fold and 18.37-fold, respectively. In 99% glycerol, the fluorescence quantum yields of probes 1a-c were 85.4%, 80.8% and 34.3% respectively. In addition, the excited state lifetime of probe 1c in 80% glycerol (725 ps) was higher than that in 40% glycerol (203 ps). More importantly, the influence of solvent polarity, pH and some potential interfering substances on probes 1a-c were negligible. And cell experiments showed that probes 1a-c could be used for monitoring the fluctuation of the mitochondrial viscosity in HeLa cells. [Display omitted] • Three fluorescent probes containing nitrogen heterocyclic and 1,8-naphthalimide were designed and synthesized. • Probes 1a-c showed specific response to viscosity. They have high fluorescence quantum yield in 99% glycerol (34.3% – 85.4%). • Excited state lifetime of probe 1c in 80% glycerol was higher than that in 40% glycerol due to limited molecular rotation. • Probes 1a-c could be used to detect changes of mitochondrial viscosity in HeLa cells. [ABSTRACT FROM AUTHOR]

[Display omitted] Five cyanine dyes (6a-e) with aza units were prepared by the reaction of pyridinum or quinolinium with suitable aldehydes. They present several remarkable features including large Stokes shift (235–282 nm), long emission wavelength (640–698 nm) and excellent selectivity. Moreover, probes 6a-b display obvious and sensitive fluorescent response to DNA and RNA in aqueous solution, and the quantum yield of probe 6a response to RNA increases from 0 to 8.9%. More importantly, probes 6c and 6e can effectively avoid DNA interference and only respond to RNA in aqueous solution. In addition, laser confocal cell experiment has showed that probe 6b can image the nucleolus of nucleic acids in HeLa cells. [ABSTRACT FROM AUTHOR]

[Display omitted] • Three viscosity-sensitive cell membrane fluorescent dyes (1a-c) were designed and synthesized. • Dyes 1a-c showed remarkable OFF-ON fluorescent response to viscosity at 563 nm, 599 nm and 601 nm, respectively. • Transient absorption spectra exhibited that dye 1b had long excited-state lifetime in 99 % glycerol environment. • Dyes 1a-c with excellent bioactivity could be stably localized on cell membrane of HeLa cells (about 3 h). In this paper, three viscosity sensitive cell membrane fluorescent dyes (1a-c) were obtained. Dyes 1a-c were linked by benzaldehyde (5) and benzoindole (2a), benzoxazole (2b) and benzothiazole (2c), with double bond, respectively. The optical properties showed that dyes 1a-c had larger molar extinction coefficients (3.34 × 104-2.64 × 105 M−1 cm−1) and excellent photostability (89–93 %). In particular, dyes 1a-c had obvious specific response to viscosity. More specifically, they indicated significant OFF-ON fluorescent response at 563 nm, 599 nm and 601 nm to the increase of viscosity (0.89–865 cp), respectively, and displayed an excellent linear relationship with viscosity. Further, the excited-state lifetime of dye 1b was evaluated as long as 828 ps in high viscosity environment by transient absorption spectra. The low cytotoxicity of dyes 1a-c , provided the possibility to be used in living cells. Accordingly, laser confocal experiments clearly exhibited that dyes 1a-c could be well located in the cell membrane. The results can assist in our understanding of the functions of cell membrane as well as application in biosensor and diagnostics. [ABSTRACT FROM AUTHOR]

1,8-Naphthalimide is widely applied in the construction of probes because it is easy to be modified. However, 1,8-naphthalimide has been reported rarely in the application of organelle labelling especially lipid droplets (LDs). Herein, three types of amine compounds, aliphatic amine (a , b), aromatic amine (c , d) and heterocyclic amine (e , f), were chosen to construct fluorescent dyes (1a - 1f) with 4-bromo- N -butylnaphthalimide (1) by Ullmann reaction. The maximum emission wavelength ranged from 490 nm to 550 nm. What's more, 1a-1e showed high fluorescence quantum yields (0.54–0.93) in chloroform and 1e-1f had excellent photostability (>92%). In addition, the cell imaging experiment showed that they could label lipid droplets for HeLa cancer cells and L929 normal cells with extremely low toxicity. This work realizes the classical fluorophore 1,8-naphthalimide to synthesize a series of LDs markers without complex synthesis steps. Image 1 • An easy way to synthesize a series of lipid droplets markers with 1,8-naphthalimide unit. • All the 1,8-naphthalimide derivatives had high photostability and fluorescence quantum yield. • All the markers showed extremely low toxicity to cells. [ABSTRACT FROM AUTHOR]

Fluorescent cell membrane probes (1a-d) were designed from bioactive oxazolo [4,5- b ]pyridine unit. The probes were connected by oxazolo [4,5- b ]pyridine and benzofuran (1a), triphenyl (1b), coumarin (1c), diethylaminobenzene (1d), respectively, with a double bond. The optical properties of 1a-d with different solvents were tested, they had obvious solvatochromism in different polar solvents, Large stokes shifts (63–204 nm) and significant fluorescent enhancement in large multilamellar vesicles (MLV). After 6 h of continuous illumination, the remaining absorption of the probes was 81–97%. The cytotoxicity test indicated that the survival rate of HeLa and L929 cells was 94–119% after co-cultured with probes 1a-d for 6 h. Laser confocal experiments further illustrated that the probes could quickly (<1 min) combine with the cell membrane. Among them, probe 1a worked in the green channel, while probes 1b, 1c and 1d employed in the red channel. Moreover, the retention time of probes 1a and 1c on cell membrane was found to 2–3 h. Image 1 • Probes (1a-d) were designed from bioactive oxazolo[4,5-b]pyridine unit. • They have large stokes shifts (63 - 204 nm) and high optical stability (81 - 97 %). • The probes can quickly (< 1 min) combine with the cell membrane. • Probes 1a and 1c can stably target the cell membrane for 2-3 hours. [ABSTRACT FROM AUTHOR]

• Probe 1 based on benzo[ e ]indole and aromatic azonia exhibited near infrared emission and high sensitivity for viscosity. • A good linear relationship between lg (I 650nm) and lg η (viscosity values from 0.89 cP to 8.6 cP). • Probe 1 with the low concentration (500 nM) could simultaneously detect changes of viscosity in mitochondria and lysosomes. • Probe 1 could be used to distinguish between cancer cells and normal cells. • Probe 1 could detect the mitochondrial and lysosomal viscosity fluctuation during autophagy. This article reported a hemicyanine dye fluorescent probe (1), based on benzo[ e ]indole and aromatic azonia skeleton, for simultaneous detection of viscosity fluctuation in mitochondria and lysosomes. Probe 1 exhibited near infrared emission and high sensitivity towards viscosity of the medium. As the viscosity increases, the rotation of C C single bond between the benzo[ e ]indole and the nitrogen heterocycle could be suppressed, and the entire molecular scaffold was coplanar and emitted strong fluorescence due to more delocalized electron distribution. The fluorescence intensity of probe 1 was enhanced 16.2 times at 650 nm as the viscosity increased from 0.89 cP to 865 cP. Correspondingly, the fluorescence quantum yield of probe 1 increased from 4.2% to 49.6%. The change of lg (I 650nm) had a good linear relationship with lg η (viscosity values: 0.89 cP to 8.6 cP), which meant the viscosity of dilute solution could be detected quantitatively. In cell experiments, probe 1 with low concentration (500 nM) had stronger fluorescence intensity in cancer cells than in normal cells. Besides, probe 1 could monitor the viscosity changes of mitochondria and lysosomes caused by the addition of ionophores (monensin, nystatin and dexamethasone) or in the process of autophagy. The results provide a simple and effective method for the early diagnosis of related diseases. [ABSTRACT FROM AUTHOR]