Ferroptosis in the adjuvant treatment of lung cancer-the potential of selected botanical drugs and isolated metabolites.

Ferroptosis represents a distinct form of cell death that is not associated with necrosis, autophagy, apoptosis, or pyroptosis. It is characterised by intracellular iron-dependent lipid peroxidation. The current literature indicates that a number of botanical drugs and isolated metabolites can modulate ferroptosis, thereby exerting inhibitory effects on lung cancer cells or animal models. The aim of this review is to elucidate the mechanisms through which botanical drugs and isolated metabolites regulate ferroptosis in the context of lung cancer, thereby providing potential insights into lung cancer treatment. It is crucial to highlight that these preclinical findings should not be interpreted as evidence that these treatments can be immediately translated into clinical applications. In the future, we will continue to study the pharmacology, pharmacokinetics and toxicology of these drugs, as well as evaluating their efficacy and safety in clinical trials, with the aim of providing new approaches to the development of new agents for the treatment of lung cancer.

Assessment of Individual and Mixed Effects of Six Minerals on Thyroid Hormones in Chinese Pregnant Women.

The biosynthesis of thyroid hormones is essential for brain and neurological development. It requires iodine as a key component but is also influenced by other nutrients. Evidence for the combined nutrient status in relation to thyroid hormones during pregnancy is limited. We aimed to investigate the joint associations of iodine, selenium, zinc, calcium, magnesium and iron with maternal thyroid functions in 489 pregnant women from Hangzhou, China. Serum levels of six essential minerals and thyroid function parameters were measured during the first antenatal visit. Linear regression, quantile g-computation and Bayesian kernel machine regression were used to explore the individual and joint relationships between the six minerals and thyroid hormones. Linear regression analyses revealed that calcium was positively associated with free triiodothyronine (FT3). Zinc was positively associated with free thyroxine (FT4). Iodine was negatively associated with thyroid-stimulating hormone (TSH) and positively associated with FT3 and FT4. The quantile g-computation and BKMR models indicated that the joint nutrient concentration was negatively associated with TSH and positively associated with FT3 and FT4. Among the six minerals, iodine contributed most to thyroid function. The findings suggested that maintaining the appropriate concentration of minerals, either as individuals or a mixture, is important for thyroid health during pregnancy.

Adjustable luminescence copper nanoclusters nanoswitch based on competitive coordination of samarium ions for cascade detection of adenosine triphosphate and acid phosphatase activity.

Benefit from the strong coordination property, lanthanide metal ions have been used as competitive reagents to modulate the fluorescence changes of the system. However, lanthanide metal ions as inducers for aggregation-induced emission enhancement in nanosystems is rare. Herein, we report a "turn on-off-on" fluorescent switch for cascade detection of acid phosphatase (ACP) and adenosine triphosphate (ATP) based on the competitive coordination of samarium ions (Sm3+). Novel copper nanoclusters (CuNCs) with long wavelength emission (614 nm) stabilized by glutathione (GSH) and glycylglycine (Gly-Gly) have been confirmed to have AIE property. With the continuous aggregation of GSH/Gly-Gly CuNCs under the induction of Sm3+, the fluorescence of the system increased to achieve the "turn-on" process. The coordinated behaviour between Sm3+ and GSH/Gly-Gly CuNCs is discussed. Due to the strong metal coordination ability of ATP, the Sm3+ coordinated with the GSH/Gly-Gly CuNCs is competed out, resulting in the fluorescence "turn-off" process of the system. As the substrate of enzymatic hydrolysis of ACP, with the continuous hydrolysis of ATP by ACP, Sm3+ coordinates with GSH/Gly-Gly CuNCs again, which leads to the AIE effect and realize the fluorescence "turn-on" process of the system. This strategy results in ATP linear range of 0.508 ~ 120.0 µM with a detection limit of 0.508 µM (S/N = 3) and ACP linear range of 0.011 ~ 30.0 U·L-1 with a detection limit of 0.011 U·L-1 (S/N = 3). Application to biologic samples was successful.

Dietary intake and serum concentrations of vitamin A and vitamin E and pre-eclampsia risk in Chinese pregnant women: A matched case-control study.

Background: Many studies have suggested that the serum concentrations of vitamin A (VA) and vitamin E (VE) influence preeclampsia (PE) risk in pregnant women. However, few studies have assessed whether dietary intake and serum concentrations of VA and VE are correlated with PE risk. Methods: A 1:1 matched case-control study was conducted to explore the association between the dietary intake and serum concentrations of VA and VE and the risk of PE in pregnant Chinese women. A total of 440 pregnant women with PE and 440 control pregnant women were included in the study. Dietary information was obtained using a 78-item semi-quantitative food frequency questionnaire. Serum concentrations of VA and VE were measured by liquid chromatography-tandem mass spectrometry. Results: Compared with the lowest quartile, the multivariate-adjusted odds ratios [95% confidence interval (CI)] of the highest quartiles were 0.62 (95% CI: 0.40-0.96, P trend = 0.02) for VA, 0.51 (95% CI: 0.33-0.80, P trend =0.002) for ß-carotene, and 0.70 (95% CI: 0.45-1.08, P trend = 0.029) for retinol. Additionally, for serum VA and VE concentrations, the multivariate-adjusted odds ratios (95% CI) were 2.75 (95% CI: 1.24-6.13, P trend = 0.002) and 11.97 (95% CI: 4.01-35.77, P trend < 0.001), respectively. No significant association was seen between VE intake and PE risk. Conclusions: Dietary VA intake was negatively correlated with PE risk, and serum VA and VE concentrations were positively correlated with PE risk among pregnant Chinese women.

Plastic ingestion and trophic transfer in an endangered top predator, the longfin mako shark (Isurus paucus), from the tropical western Pacific Ocean.

Plastic pollution has become a global environmental problem of major concern. However, the plastic contamination in the marine top predators, particularly in endangered species, is incompletely understood because of the limited amount of data on their presence in the digestive system and prey. This study investigated the stomach contents of an endangered but poorly known shark species, the longfin mako shark (Isurus paucus), found in the tropical western Pacific Ocean. We examined the plastics in this female specimen (1.22-m fork length) and her prey to assess the potential for trophic transfer of microplastics. Polypropylene bottle cap and lollipop packaging, longnose lancetfish (Alepisaurus ferox), and squid were found in the stomach of I. paucus, while no apparent internal injuries were noted. The microplastic fragments and granules, confirmed by laser direct infrared spectroscopy, were found in the digestive system of the intact squid ingested by I. paucus, suggesting that trophic transfer may occur between shark and prey. These results indicate that I. paucus is vulnerable to plastic ingestion and provide evidence of trophic transfer of microplastics in shark species. Our study emphasizes the need to evaluate the potential ecotoxicological consequences of increasing plastic pollution to endangered marine top predators.

Microplastic contamination and risk assessment in blue shark (Prionace glauca) from the eastern tropical Pacific Ocean.

We quantified the abundance and characteristics of microplastics in the blue shark, Prionace glauca, found in the eastern tropical Pacific Ocean and investigated the potential microplastic pollution risks. Microplastics (MPs) were detected in 39.1 % of specimens, up to 0.15 ± 0.38 items/g wet weight of the posterior part of the pylorus, and were sized 45.87 to 3220.12 µm. The majority were fibrous in shape (83.3 %) and blue in color (72.2 %). Both sexes of sharks had similar MP abundance and characteristics, except for polymers, with polyethylene terephthalate and polypropylene representing the dominant type in males and females, respectively. Most individuals experienced low pollution, but one male P. glauca exhibited a high ecological risk level owing to the high MP abundance and detection of polyvinyl chloride. This study provides an important baseline for the ingestion of microplastics by pelagic shark species and is a preliminary quantitative measure that could be used in future studies of the risk of MPs.

Ratiometric fluorescence and visual determination of tetracycline antibiotics based on Y3+ and copper nanoclusters-induced cascade signal amplification.

A ratiometric fluorescence probe is proposed for sensitive and visual detection of tetracyclinee (TC) based on cascade fluorescence signal amplification induced by bovine serum albumin-stabilized copper nanoclusters (BSA-CuNCs) and yttrium ions (Y3+). TC can combine with Y3+ to form the complex (TC-Y3+) to enhance the fluorescence of TC at 515 nm. Then, positively charged TC-Y3+ and negatively charged BSA-CuNCs was bonded together by electrostatic interactions to achieve the fluorescence resonance energy transfer (FRET) process. With the increase of TC concentration, the fluorescence intensity of TC-Y3+ at 515 nm (F515) gradually increased; meanwhile, the fluorescence intensity of BSA-CuNCs at 405 nm (F405) decreased gradually. The ratio of F515 and F405 was used for the quantitative determination of TC. The linear range of the constructed fluorescent probe is 1.0 to 60.0 µM, and the limit of detection is 0.22 µM. The method was successfully applied to the determination of TC in spiked milk with recoveries ranging from 94.3 to 112%. Furthermore, the color of this platform can be observed from dark violet to bright green under the UV lamp. Since the response time of the reaction is less than 10 s, an intelligent sensing platform based on the use of the smartphone as image acquisition equipment was also established to realize rapid on-site and portable detection of TC through the colorimetric recognition application.

Comparative Genomic Analysis of Seven Vibrio alginolyticus Strains Isolated From Shrimp Larviculture Water With Emphasis on Chitin Utilization.

The opportunistic pathogen Vibrio alginolyticus is gaining attention because of its disease-causing risks to aquatic animals and humans. In this study, seven Vibrio strains isolated from different shrimp hatcheries in Southeast China were subjected to genome sequencing and subsequent comparative analysis to explore their intricate relationships with shrimp aquaculture. The seven isolates had an average nucleotide identity of ≥ 98.3% with other known V. alginolyticus strains. The species V. alginolyticus had an open pan-genome, with the addition of ≥ 161 novel genes following each new genome for seven isolates and 14 publicly available V. alginolyticus strains. The percentages of core genes of the seven strains were up to 83.1-87.5%, indicating highly conserved functions, such as chitin utilization. Further, a total of 14 core genes involved in the chitin degradation pathway were detected on the seven genomes with a single copy, 12 of which had undergone significant purifying selection (dN/dS < 1). Moreover, the seven strains could utilize chitin as the sole carbon-nitrogen source. In contrast, mobile genetic elements (MGEs) were identified in seven strains, including plasmids, prophages, and genomic islands, which mainly encoded accessory genes annotated as hypothetical proteins. The infection experiment showed that four of the seven strains might be pathogenic because the survival rates of Litopenaeus vannamei postlarvae were significantly reduced (P < 0.05) when compared to the control. However, no obvious correlation was noted between the number of putative virulence factors and toxic effects of the seven strains. Collectively, the persistence of V. alginolyticus in various aquatic environments may be attributed to its high genomic plasticity via the acquisition of novel genes by various MGEs. In view of the strong capability of chitin utilization by diverse vibrios, the timely removal of massive chitin-rich materials thoroughly in shrimp culture systems may be a key strategy to inhibit proliferation of vibrios and subsequent infection of shrimp. In addition, transcontinental transfer of potentially pathogenic V. alginolyticus strains should receive great attention to avoid vibriosis.

The effects of temperature variability on mortality in patients with chronic obstructive pulmonary disease: a time-series analysis in Hangzhou, China.

Chronic obstructive pulmonary disease (COPD) is a leading cause of death in people aged over 60 years old. Research has been reported that ambient temperature and diurnal temperature range (DTR), as representative indices of temperature variability, are contributors to the development and exacerbation of COPD. However, few studies are available in Chinese population. In this study, we aimed to assess the associations of temperature variability on COPD mortality in a fast developing city in China. Using the mortality surveillance system, we obtained a total of 7,863 deaths attributed to COPD from 2014 to 2016. Quasi-Poisson generalized linear regression with distributed lag non-linear model was applied to explore the associations between temperature variability and COPD deaths, after controlling for the potential confounders, including relative humidity, day of week, public holiday, and long-term trend. A J-shaped association of DTR and a reversely J-shaped association of temperature for COPD mortality were observed. Risk estimates showed that the relative risks (RRs) of COPD mortality with extreme high DTR at lag 0 and 0-7 days were 1.045 (95% CI: 0.949-1.151) and 1.460 (95% CI: 1.118-1.908), and the extreme high temperature at lag 0 and 0-7 days were 1.090 (95% CI: 0.945-1.256) and 1.352 (95% CI: 1.163-1.572). Our findings suggest that short-term exposure to extreme temperature was associated with mortality for COPD in Hangzhou. The evidence has implications for policy decision-making and targeted interventions.

Dietary carotenoid intake and risk of developing preeclampsia: a hospital-based case-control study.

BACKGROUND: The effect of carotenoids on the risk of preeclampsia (PE) is uncertain. We aimed to examine the associations between the intake of dietary carotenoids and related compounds by pregnant women in China, and the risk of their developing PE. METHODS: Four hundred and forty PE cases and 440 age- (± 3 years), gestational age- (± 1 weeks) and gestational diabetes mellitus status- (yes/no) matched healthy controls were recruited from March 2016 to June 2019. Dietary intake of carotenoids was assessed using a 79-item validated food-frequency questionnaire. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using conditional logistic regression. RESULTS: After adjusting for potential confounders, we found that the intake of total carotenoids, ß-carotene, ß-cryptoxanthin, lycopene, and lutein and zeaxanthin (lut-zea) were negatively associated with the odds of developing PE. Compared with the lowest quartile intake, the multivariate-adjusted OR (95% CI) of the highest quartile intake was 0.29 (0.16-0.54, Ptrend <  0.001) for total carotenoids, 0.31 (0.16-0.58, Ptrend <  0.001) for ß-carotene, 0.50 (0.27-0.90, Ptrend = 0.007) for ß-cryptoxanthin, 0.55 (0.30-0.99, Ptrend = 0.04) for lycopene and 0.32 (0.17-0.61, Ptrend = 0.001) for lut-zea. However, no significant associations were observed between the risk of developing PE and α-carotene intake (OR = 0.75, 95% CI: 0.41-1.36, Ptrend = 0.28). Moreover, similar negative associations were found for every one-standard-deviation increase in the intake of total carotenoids, ß-carotene, ß-cryptoxanthin, lycopene and lut-zea. CONCLUSION: These results indicate that a high intake of total carotenoids, ß-carotene, ß-cryptoxanthin, lycopene and lut-zea may be associated with a low risk of developing PE.

Serum uric acid level and all-cause and cardiovascular mortality in peritoneal dialysis patients: A systematic review and dose-response meta-analysis of cohort studies.

BACKGROUND: The association between serum uric acid (SUA) and all-cause and cardiovascular disease (CVD) mortality in peritoneal dialysis (PD) patients is controversial. Therefore, we aimed to determine the relationship between SUA and all-cause and CVD mortality in PD patients. METHOD: Web of Science, EMBASE, PubMed and the Cochrane Library databases were searched from their inception to 7 April 2021. Effect estimates were presented as hazard ratios (HRs) with 95% confidence intervals (95% CIs) and pooled using random effects model. RESULT: Thirteen cohort studies with 22418 patients were included in this systematic review, of which 9 were included in the meta-analysis. Before switching the reference group, pooled result for the highest SUA category was significantly greater than the median for all-cause mortality (HR = 2.41, 95% CI: 1.37-4.26). After switching the reference group, the highest SUA category did not demonstrate an increased all-cause (HR = 1.40, 95% CI: 0.95-2.05) or CVD (HR = 1.30, 95% CI: 0.72-2.34) mortality compared with the lowest SUA category. Dose-response analysis suggested a nonlinear association between SUA and all-cause mortality risk (Pnonlinearity = 0.002). CONCLUSION: This meta-analysis didn't find the relationship between SUA levels and all-cause and CVD mortality risk in PD patients. More rigorously designed studies are warranted in the future.

Controllable release ratiometric fluorescent sensor for hyaluronidase via the combination of Cu2+-Fe-N-C nanozymes and degradable intelligent hydrogel.

As a popular controllable-released carrier, intelligent hydrogels are often used in drug delivery and disease therapeutics. Meanwhile, benefit from the mimic-enzyme activity performance, Fe-N-C nanozymes have been widely used in sensing and analysis. However, the combination of intelligent hydrogels with specific degradability and Fe-N-C nanozymes with enhanced activity in one system to achieve controllable and sensitive detection is rare. Herein, we combine intelligent hydrogel with mimic peroxidase activity enhanced Fe-N-C nanozymes to construct a ratiometric fluorescence probe for sensitive detection of hyaluronidase (HAase). The modification of copper ions has been proved to enhance the mimic enzyme activity of Fe-N-C nanozymes greatly. Cu2+ modified Fe-N-C nanozymes were embedded in hyaluronic acid hydrogel. In the presence of HAase, the HA hydrogel structure was hydrolyzed and released Cu2+-Fe-N-C nanozymes gradually. The released Cu2+-Fe-N-C nanozymes are used to catalyze the hydrogen peroxide system so that o-phenylenediamine is oxidized to orange fluorescent 2, 3-diaminophenolazine (DAP). Due to the electrostatic interaction, the fluorescence resonance energy transfer can occur between the negatively charged copper nanoclusters emitted by 430 nm and the positively charged DAP emitted by 560 nm. The activity of HAase was monitored according to the ratio of fluorescence intensity at 560 nm and 430 nm (F560/F430). The linear range of this method is 0-10.0 U/ml and the detection limit is 0.43 U/mL (S/N = 3). This strategy has been further applied to biological samples successfully.

Dietary and serum vitamin D and preeclampsia risk in Chinese pregnant women: a matched case-control study.

The effect of vitamin D (VD) on the risk of preeclampsia (PE) is uncertain. Few of previous studies focused on the relationship between dietary VD intake and PE risk. Therefore, we conducted this 1:1 matched case-control study to explore the association of dietary VD intake and serum VD concentrations with PE risk in Chinese pregnant women. A total of 440 pairs of participants were recruited during March 2016 to June 2019. Dietary information was obtained using a seventy-eight-item semi-quantitative FFQ. Serum concentrations of 25(OH)D2 and 25(OH)D3 were measured by liquid chromatography-tandem MS. Multivariate conditional logistic regression was used to estimate OR and 95 % CI. Restricted cubic splines (RCS) were plotted to evaluate the dose-response relationship of dietary VD intake and serum VD concentrations with PE risk. Compared with the lowest quartile, the OR of the highest quartile were 0·45 (95 % CI 0·29, 0·71, Ptrend = 0·001) for VD dietary intake and 0·26 (95 % CI 0·11, 0·60, Ptrend = 0·003) for serum levels after adjusting for confounders. In addition, the RCS analysis suggested a reverse J-shaped relationship between dietary VD intake and PE risk (P-nonlinearity = 0·02). A similar association was also found between serum concentrations of total 25(OH)D and PE risk (P-nonlinearity = 0·02). In conclusion, this study provides evidence that higher dietary intake and serum levels of VD are associated with the lower risk of PE in Chinese pregnant women.

Low Iodine Intake May Decrease Women's Fecundity: A Population-Based Cross-Sectional Study.

Salt iodization is one of the most cost-effective strategies to eliminate iodine deficiency disorders (IDD). However, China's dismantling of salt monopoly has reduced the availability of iodized salt in the susceptible population in pregnancy, which might cause IDD and have adverse health effects on both themselves and their offspring. The aim of our study was therefore to explore the association between IDD and women's reproductive health. This is a population-based cross-sectional study conducted in 2018 in Zhejiang Province, China. A total of 1653 pregnant women participated in this study. Median urinary iodine concentration (UIC) in the population was used to assess iodine intake. Cox regression analyses were used to estimate the association between iodine intake and time to pregnancy, which was indicated with fecundability ratio (FR) and 95% confidence interval (CI). The percentage of participants with iodine deficiency who had been waiting longer than 13 months to get pregnant (20%; median UIC 119.6 µg/L) was significantly higher than those with iodine sufficiency (14%; median UIC 147.1 µg/L). A significant decrease in fecundity was observed in participants with iodine deficiency (FR, 0.820; 95% CI, 0.725-0.929) than those with iodine sufficiency. These findings indicate the importance of ongoing monitoring of iodine nutrition in women of reproductive age. Keeping a safe and optimal level of iodine nutrition during pregnancy should be emphasized.

Dietary patterns and sarcopenia in a Chinese population.

BACKGROUND AND OBJECTIVES: Malnutrition is implicated as a key modifiable risk factor for sarcopenia. As such, a dietary pattern analysis, rather than an analysis of single food items or nutrients, may provide insights into the comprehensive contribution of diet and nutrition to the risk of sarcopenia. Accordingly, the aim of this study was to evaluate the relationships between main dietary patterns and sarcopenia. METHODS AND STUDY DESIGN: A total of 591 participants aged over 40 years were included in this cross-sectional study. A validated food-frequency questionnaire was used to assess their dietary intake, and principal component analysis (PCA) was used to identify the main dietary patterns. A multivariate logistic regression model was used to explore the associations between their main dietary patterns and the risk of sarcopenia. RESULTS: This study identified 56 cases of sarcopenia, equating to an overall detection rate of 9.48%. The PCA revealed four major dietary patterns among the participants: "coarse cereals and vegetables"; "beverages and animal organs"; "poultry, fish and shrimp"; and "fruits and pasta". After adjusting for age, sex, physical activity and smoking, individuals with the "coarse cereals and vegetables" dietary pattern had a 63.0% reduction in the risk of sarcopenia. CONCLUSIONS: The "coarse cereals and vegetables" dietary pattern is negatively correlated with sarcopenia, and may reduce the risk of sarcopenia.

A dual-mode strategy for sensing and bio-imaging of endogenous alkaline phosphatase based on the combination of photoinduced electron transfer and hyperchromic effect.

Benefit from the additional correction of the output signal in dual-mode detection, traditional dual signal readout strategies are performed by constructing the ratiometric fluorescent probe through excitation energy transfer (EET) or fluorescence resonance energy transfer (FRET). To avoid the complicated modification process and obtain the results rapidly, a simple dual-mode sensing strategy based on the electronic effects of p-nitrophenol (PNP) is described to monitor the activities of alkaline phosphatase (ALP). In the sensing platform, p-nitrophenylphosphate was used as a substrate to produce the PNP using ALP as the catalyst. Due to the PNP possesses negative effect of induction and conjugation, photoinduced electron transfer and hyperchromic effect have been achieved between PNP and polyethyleneimine-protected copper nanoclusters (PEI-Cu NCs), which caused the changes of the fluorescence intensity and UV-visible absorption. The dual-mode signal sensing system showed the satisfactory linear results of ALP from 1 to 100 U/L for fluorescent sensing strategy and 1-70 U/L for the absorption method with a competitive LOD of 0.27 and 0.87 U/L (signal-to-noise ratio of 3). This strategy detected biological ALP in human serum and bio-imaging of endogenous ALP in A549 cells successfully, which verifies a certain potential of the strategy for the practical applications.

A fluorescence signal amplification and specific energy transfer strategy for sensitive detection of ß-galactosidase based on the effects of AIE and host-guest recognition.

Benefit from the efficient energy transfer, aggregation-induced emission (AIE) and host-guest recognition as strategies of signal amplification and specific binding have been applied to establish the sensing system; however, the application of these two attractive strategies in one system is rare. Herein, we propose a "turn-on" to "turn-off" fluorescent strategy for sensitive detection of ß-galactosidase (ß-Gal) based on the application of AIE and host-guest recognition. In this work, a novel red-emitted (635 nm) copper nanoclusters (CuNCs) protected by dithioerythritol (DTE) and ß-cyclodextrin (ß-CD) has been found to possess AIE property induced by aluminum cations to achieve the "turn-on" process, and the coordinated behavior between aluminum cations and DTE/ß-CD CuNCs is also discussed. As the hydrolysis product of ß-Gal and 4-nitrophenyl-ß-D-galactopyranoside, p-nitrophenol can combine with ß-CD in DTE/ß-CD CuNCs by the host-guest recognition to realize the efficient photoelectron transfer to "turn-off" the fluorescence. This strategy performs the exciting linear range of 0.0-50.0 U/L and detection limit of 0.56 U/L (S/N = 3) for sensitive detection of ß-Gal and further applies in biologic samples successfully. As far as we know, this is the first work to combine AIE and host-guest recognition in one system to construct the sensing platform, which can achieve efficient and specific energy transfer to improve the sensitivity of the system.

Apparent Contact Angle around the Periphery of a Liquid Drop on Roughened Surfaces.

The wetting of roughened surfaces is complicated since not all of the surface of the irregular surface is wetted and thus, the three-phase contact line for the liquid drop is a complex, three-dimensional line that varies according to the dimensions of the roughness and its spatial heterogeneity. This can cause the contact line to not sit within a constant height horizontal plane especially when air is trapped underneath the liquid layer. Here, we explore the effect of roughness on the effective contact angle of a water droplet on a roughened hydrophobic surface. The results show that the apparent contact angle varies around the periphery of the droplet due to the roughness of the surface on first contact. Also, repeated wetting of the droplet on the surface reveals that the apparent contact angle changes due to residual liquid remaining on the roughened surface. The results also show that the Wenzel and Cassie-Baxter models tend to overestimate the apparent contact angle on the roughened surfaces.

A fluorescence signal amplification strategy for modification-free ratiometric determination of tyrosinase in situ based on the use of dual-templated copper nanoclusters.

A fluorescence resonance energy transfer (FRET)-based in situ fluorescence signal amplification strategy is described for the determination of tyrosinase (TYR). In this assay, a dual-templated copper nanocluster (CuNCs) stabilized by bovine serum albumin (BSA) and glycylglycine (Gly-Gly) was used as an energy donor. Metyrosine was employed as a TYR substrate because its enzyme catalytic product (methyldopa) was able to function as a monomer molecule to form fluorescent polymethyldopa (PMeDP) with the assistance of BSA/Gly-Gly CuNCs. In this process, PMeDP can combine with BSA/Gly-Gly CuNCs without extra modification and then acts as an energy receptor, which leads to a remarkable FRET from BSA/Gly-Gly CuNCs to PMeDP. Interestingly, the fluorescence intensity of PMeDP was strengthened greatly in the FRET-based sensor compared to the separate excitation, which provided good sensitivity for TYR sensing. Illuminated under a UV light source, the fluorescence signal change is observed from dark violet to bright green. Therefore, the present sensing system affords a reliable ratiometric assay for TYR determination. Also, the ratio of fluorescence intensity between PMeDP (λem at 505 nm, F505) and BSA/Gly-Gly CuNCs (λem at 415 nm, F415) was used for quantitative determination of TYR. The sensing system was easily operated in aqueous media with an exciting detection limit of 44.0 U L-1. This sensing strategy has been applied to the screening of inhibitors. Graphical abstract Schematic representation of the strategy for the determination of tyrosinase.

Molecular cloning, characterization, and expression of two TNFRs from the pearl oyster Pinctada fucata martensii.

Proteins in the tumor necrosis factor receptor (TNFR) superfamily play significant roles in many physiological and pathological events, such as inflammation, apoptosis, autoimmunity, and organogenesis. Here, two TNFR gene homologs (PmTNFR1 and PmTNFR5) were identified in the pearl oyster Pinctada fucata martensii. The predicted PmTNFR1 and PmTNFR5 protein sequences were 406 and 533 amino acids long, respectively, and both possessed motifs characteristic of the TNFR family, including a TNFR homology domain (CRD), a transmembrane domain (TM), and death domains. However, the predicted amino acid sequences of PmTNFR1 and PmTNFR5 had low identity (~16-23%) with sequences of vertebrate TNFR family proteins. Furthermore, PmTNFR5 had a death domain at the C-terminal, indicating that this protein may be a novel member of the TNFR superfamily. Constitutive PmTNFR1 and PmTNFR5 mRNA expression was detected in all six pearl oyster tissues tested, with comparatively greater transcript abundance in the hepatopancreas and gill. The gene expression levels of PmTNFR1 and PmTNFR5, as well as those of downstream signaling molecules related to the NF-κB pathway (RIP, TRAF2, TRAF3, IKK, and NF-κB), were quantified in the gill after LPS challenge and in the hemocytes after nucleus insertion surgery using real-time PCR (qRT-PCR). We found that all genes were significantly upregulated at 6 h and 12 h post-injection, as well as at 15 d post-insertion. We used RNAi to inhibit the expression of the PmTNFR1 and PmTNFR5 genes. We then quantified the expression levels of PmTNFR1 and PmTNFR5, as well as downstream genes, using qRT-PCR. We found that RNAi inhibition of PmTNFR1 and PmTNFR5 downregulated the downstream genes (RIP, TRAF2, TRAF3, IKK, and NF-κB). Therefore, our results suggested that PmTNFR1 and PmTNFR5 mediate the NF-κB signaling pathway, and are closely related to immune defense, particularly allograft immunity, in the pearl oyster P. fucata martensii.