Restricted responses of AcMYB68 and AcERF74/75 enhanced waterlogging tolerance in kiwifruit.

Most of kiwifruit cultivars (e.g. Actinidia chinensis cv. Donghong, "DH") were sensitive to waterlogging, thus, waterlogging resistant rootstocks (e.g. Actinidia valvata Dunn, "Dunn") were widely used for kiwifruit industry. Those different species provided ideal materials to understand the waterlogging responses in kiwifruit. Compared to the weaken growth and root activities in "DH", "Dunn" maintained the relative high root activities under the prolonged waterlogging. Based on comparative analysis, transcript levels of pyruvate decarboxylase (PDCs) and alcohol dehydrogenase (ADHs) showed significantly difference between these two species. Both PDCs and ADHs had been significantly increased by waterlogging in "DH", while they were only limitedly triggered by 2 days stress and subsided during the prolonged waterlogging in "Dunn". Thus, 19 differentially expressed transcript factors (DETFs) had been isolated using weighted gene co-expression network analysis combined with transcriptomics and transcript levels of PDCs and ADHs in waterlogged "DH". Among these DETFs, dual luciferase and electrophoretic mobility shift assays indicated AcMYB68 could bind to and trigger the activity of AcPDC2 promoter. The stable over-expression of AcMYB68 significantly up-regulated the transcript levels of PDCs but inhibited the plant growth, especially the roots. Moreover, the enzyme activities of PDC in 35S::AcMYB68 were significantly enhanced during the waterlogging response than that in wild type plants. Most interestingly, comparative analysis indicated that the expression patterns of AcMYB68 and the previously characterized AcERF74/75 (the direct regulator on ADHs) either showed no responses (AcMYB68 and AcERF74) or very limited response (AcERF75) in "Dunn". Taken together, the restricted responses of AcMYB68 and AcERF74/75 in "Dunn" endow its waterlogging tolerance.

A New Bacillus velezensis Strain CML532 Improves Chicken Growth Performance and Reduces Intestinal Clostridium perfringens Colonization.

Bacillus velezensis has gained increasing recognition as a probiotic for improving animal growth performance and gut health. We identified six B. velezensis strains from sixty Bacillus isolates that were isolated from the cecal samples of fifteen different chicken breeds. We characterized the probiotic properties of these six B. velezensis strains. The effect of a selected strain (B. velezensis CML532) on chicken growth performance under normal feeding and Clostridium perfringens challenge conditions was also evaluated. The results revealed that the six B. velezensis strains differed in their probiotic properties, with strain CML532 exhibiting the highest bile salt and acid tolerance and high-yield enzyme and antibacterial activities. Genomic analyses showed that genes related to amino acid and carbohydrate metabolism, as well as genes related to starch and cellulose hydrolysis, were abundant in strain CML532. Dietary supplementation with strain CML532 promoted chicken growth, improved the gut barrier and absorption function, and modulated the gut microbiota. Under the C. perfringens challenge condition, strain CML532 alleviated intestinal damage, reduced ileal colonization of C. perfringens, and also improved chicken growth performance. Collectively, this study demonstrated that the newly isolated B. velezensis strain is a promising probiotic with beneficial effects on chicken growth performance and gut health.

An all-inorganic lead-free metal halide double perovskite for the highly selective detection of norfloxacin in aqueous solution.

Lead-based perovskites are highly susceptible to environmental influences, and their application in analytical chemistry, especially in aqueous solution, has been reported rarely. All-inorganic lead-free metal halide perovskites have been considered as a substitute for lead-based perovskites. Herein, a Cs2RbTbCl6 perovskite microcrystal (PMCs), which emits strong yellow-green fluorescence with a maximum emission wavelength at 547 nm, was for the first time  synthesized and characterized. The Cs2RbTbCl6 PMCs could be well dispersed in N,N-dimethylacetamide (DMF), and its fluorescence could be significantly enhanced by the addition of norfloxacin (NOR) in the aqueous solution. We found that the Cs2RbTbCl6 PMCs can be used as fluorescent probes (excitation, 365 nm; emission, 547 nm) to selectively detect NOR in a concentration range from 10.0 to 200.0 µM with the limit of detection (LOD) being 0.04 µM. The Cs2RbTbCl6 PMCs could also be adsorbed on filter paper to fabricate as a fluorescent test paper for visual detection of NOR under 365-nm ultraviolet (UV) lamp irradiation. The proposed method has the potential to establish a new analytical method to visualize the detection of NOR in aqueous environments and also promotes the application of all-inorganic lead-free perovskites for analytical detection in aqueous environments.

AcHZP45 is a repressor of chlorophyll biosynthesis and activator of chlorophyll degradation in kiwifruit.

The degradation of chlorophyll during fruit development is essential to reveal a more 'ripe' color that signals readiness to wild dispersers of seeds and the human consumer. Here, comparative biochemical analysis of developing fruit of Actinidia deliciosa cv. Xuxiang ('XX', green-fleshed) and Actinidia chinensis cv. Jinshi No.1 ('JS', yellow-fleshed) indicated that variation in chlorophyll content is the major contributor to differences in flesh color. Four differentially expressed candidate genes were identified: the down-regulated genes AcCRD1 and AcPOR1 involved in chlorophyll biosynthesis, and the up-regulated genes AcSGR1 and AcSGR2 driving chlorophyll degradation. Prochlorophyllide and chlorophyllide, the metabolites produced by AcCRD1 and AcPOR1, progressively reduced in 'JS', but not in 'XX', indicating that chlorophyll biosynthesis was less active in yellow-fleshed fruit. AcSGR1 and AcSGR2 were verified to be involved in chlorophyll degradation, using both transient expression in tobacco and stable overexpression in kiwifruit. Furthermore, a homeobox-leucine zipper (HD-Zip II), AcHZP45, showed significantly increased expression during 'JS' fruit ripening, which led to both repressed expression of AcCRD1 and AcPOR1 and activated expression of AcSGR1 and AcSGR2. Collectively, the present study indicated that different dynamics of chlorophyll biosynthesis and degradation coordinate the changes in chlorophyll content in kiwifruit flesh, which are orchestrated by the key transcription factor AcHZP45.

Enzymatically prepared neoagarooligosaccharides improve gut health and function through promoting the production of spermidine by Faecalibacterium in chickens.

Maintaining animal gut health through modulating the gut microbiota is a constant need when antibiotics are not used in animal feed during the food animal production process. Prebiotics is regarded as one of the most promising antibiotic alternatives for such purpose. As an attractive prebiotic, the role and mechanisms of neoagarooligosaccharides (NAOS) in promoting animal growth and gut health have not been elucidated. In this study, we first cloned and expressed marine bacterial ß-agarase in yeast to optimize the NAOS preparation and then investigated the role and the underlying mechanisms of the prepared NAOS in improving chicken gut health and function. The marine bacterial ß-agarase PDE13B was expressed in Pichia pastoris GS115 and generated even-numbered NAOS. Dietary the prepared NAOS promoted chicken growth and improved intestinal morphology, its barrier, and digestion capabilities, and absorption function. Metagenomic analysis indicated that NAOS modulated the chicken gut microbiota structure and function, and microbial interactions, and promoted the growth of spermidine-producing bacteria especially Faecalibacterium. Through integration of gut metagenome, gut content metabolome, and gut tissue transcriptome, we established connections among NAOS, gut microbes, spermidine, and chicken gut gene expression. The spermidine regulation of genes related to autophagy, immunity, and inflammation was further confirmed in chicken embryo intestinal epithelium cells. We also verified that NAOS can be utilized by Faecalibacterium prausnitzii to grow and produce spermidine in in vitro experiments. Collectively, we provide a systematic investigation of the role of NAOS in regulating gut health and demonstrate the microbial spermidine-mediated mechanism involved in prebiotic effects of NAOS, which lays foundation for future use of NAOS as a new antibiotic alternative in animal production.

Identification of miRNA858 long-loop precursors in seed plants.

MicroRNAs (miRNAs) are a class of nonprotein-coding short transcripts that provide a layer of post-transcriptional regulation essential to many plant biological processes. MiR858, which targets the transcripts of MYB transcription factors, can affect a range of secondary metabolic processes. Although miR858 and its 187-nt precursor have been well studied in Arabidopsis (Arabidopsis thaliana), a systematic investigation of miR858 precursors and their functions across plant species is lacking due to a problem in identifying the transcripts that generate this subclass. By re-evaluating the transcript of miR858 and relaxing the length cut-off for identifying hairpins, we found in kiwifruit (Actinidia chinensis) that miR858 has long-loop hairpins (1,100 to 2,100 nt), whose intervening sequences between miRNA generating complementary sites were longer than all previously reported miRNA hairpins. Importantly, these precursors of miR858 containing long-loop hairpins (termed MIR858L) are widespread in seed plants including Arabidopsis, varying between 350 and 5,500 nt. Moreover, we showed that MIR858L has a greater impact on proanthocyanidin and flavonol levels in both Arabidopsis and kiwifruit. We suggest that an active MIR858L-MYB regulatory module appeared in the transition of early land plants to large upright flowering plants, making a key contribution to plant secondary metabolism.

Integrated multi-omics reveals the roles of cecal microbiota and its derived bacterial consortium in promoting chicken growth.

IMPORTANCE: The improvement of chicken growth performance is one of the major concerns for the poultry industry. Gut microbes are increasingly evidenced to be associated with chicken physiology and metabolism, thereby influencing chicken growth and development. Here, through integrated multi-omics analyses, we showed that chickens from the same line differing in their body weight were very different in their gut microbiota structure and host-microbiota crosstalk; microbes in high body weight (HBW) chickens contributed to chicken growth by regulating the gut function and homeostasis. We also verified that a specific bacterial consortium consisting of isolates from the HBW chickens has the potential to be used as chicken growth promoters. These findings provide new insights into the potential links between gut microbiota and chicken phenotypes, shedding light on future manipulation of chicken gut microbiota to improve chicken growth performance.

Examining structural factors influencing cancer care experienced by Inuit in Canada: a scoping review.

Inuit face worse cancer survival rates and outcomes than the general Canadian population. Persistent health disparities cannot be understood without examining the structural factors that create inequities and continue to impact the health and well-being of Inuit. This scoping review aims to synthesise the available published and grey literature on the structural factors that influence cancer care experienced by Inuit in Canada. Guided by Inuit input from Pauktuutit Inuit Women of Canada as well as the Joanna Briggs Institute scoping review methodology, a comprehensive electronic search along with hand-searching of grey literature and relevant journals was conducted. A total of 30 papers were included for analysis and assessment of relevance. Findings were organised into five categories as defined in the a priori framework related to colonisation, as well as health systems, social, economic, and political structures. The study results highlight interconnections between racism and colonialism, the lack of health service information on urban Inuit, as well as the need for system-wide efforts to address the structural barriers in cancer care.

A dramatic decline in fruit citrate induced by mutagenesis of a NAC transcription factor, AcNAC1.

Citrate is a common primary metabolite which often characterizes fruit flavour. The key regulators of citrate accumulation in fruit and vegetables are poorly understood. We systematically analysed the dynamic profiles of organic acid components during the development of kiwifruit (Actinidia spp.). Citrate continuously accumulated so that it became the predominate contributor to total acidity at harvest. Based on a co-expression network analysis using different kiwifruit cultivars, an Al-ACTIVATED MALATE TRANSPORTER gene (AcALMT1) was identified as a candidate responsible for citrate accumulation. Electrophysiological assays using expression of this gene in Xenopus oocytes revealed that AcALMT1 functions as a citrate transporter. Additionally, transient overexpression of AcALMT1 in kiwifruit significantly increased citrate content, while tissues showing higher AcALMT1 expression accumulated more citrate. The expression of AcALMT1 was highly correlated with 17 transcription factor candidates. However, dual-luciferase and EMSA assays indicated that only the NAC transcription factor, AcNAC1, activated AcALMT1 expression via direct binding to its promoter. Targeted CRISPR-Cas9-induced mutagenesis of AcNAC1 in kiwifruit resulted in dramatic declines in citrate levels while malate and quinate levels were not substantially affected. Our findings show that transcriptional regulation of a major citrate transporter, by a NAC transcription factor, is responsible for citrate accumulation in kiwifruit, which has broad implications for other fruits and vegetables.

Hydroxyl-Directed Rh(III)-Catalyzed C-H Functionalization: Access to Benzo[de]chromenes.

A cascade oxidative annulation reaction of heterocyclic ketene aminals (HKAs) with internal alkynes catalyzed by [Cp*RhCl2]2 and oxidized by Cu(OAc)2·H2O was developed to efficiently synthesize highly functionalized benzo[de]chromene derivatives in good to excellent yields. The reaction proceeded by the sequential cleavage of C(sp2)-H/O-H and C(sp2)-H/C(sp2)-H bonds. These multicomponent cascade reactions were highly regioselective. In addition, all of the benzo[de]chromene products exhibited intense fluorescence emission in the solid state, and they demonstrated concentration-dependent quenching in the presence of Fe3+, indicating that these compounds could be used in the recognition of Fe3+.

Consensus co-expression network analysis identifies AdZAT5 regulating pectin degradation in ripening kiwifruit.

INTRODUCTION: Cell wall degradation and remodeling is the key factor causing fruit softening during ripening. OBJECTIVES: To explore the mechanism underlying postharvest cell wall metabolism, a transcriptome analysis method for more precious prediction on functional genes was needed. METHODS: Kiwifruits treated by ethylene (a conventional and effective phytohormone to accelerate climacteric fruit ripening and softening as kiwifruits) or air were taken as materials. Here, Consensus Coexpression Network Analysis (CCNA), a procedure evolved from Weighted Gene Co-expression Network Analysis (WGCNA) package in R, was applied and generated 85 consensus clusters from twelve transcriptome libraries. Advanced and comprehensive modifications were achieved by combination of CCNA and WGCNA with introduction of physiological traits, including firmness, cell wall materials, cellulose, hemicellulose, water soluble pectin, covalent binding pectin and ionic soluble pectin. RESULTS: As a result, six cell wall metabolisms related structural genes AdGAL1, AdMAN1, AdPL1, AdPL5, Adß-Gal5, AdPME1 and four transcription factors AdZAT5, AdDOF3, AdNAC083, AdMYBR4 were identified as hub candidate genes for pectin degradation. Dual-luciferase system and electrophoretic mobility shift assays validated that promoters of AdPL5 and Adß-Gal5 were recognized and trans-activated by transcription factor AdZAT5. The relatively higher enzyme activities of PL and ß-Gal were observed in ethylene treated kiwifruit, further emphasized the critical roles of these two pectin related genes for fruit softening. Moreover, stable transient overexpression AdZAT5 in kiwifruit significantly enhanced AdPL5 and Adß-Gal5 expression, which confirmed the in vivo regulations between transcription factor and pectin related genes. CONCLUSION: Thus, modification and application of CCNA would be powerful for the precious phishing the unknown regulators. It revealed that AdZAT5 is a key factor for pectin degradation by binding and regulating effector genes AdPL5 and Adß-Gal5.

Transcriptional and post-transcriptional regulation of ethylene biosynthesis by exogenous acetylsalicylic acid in kiwifruit.

Levels of ethylene, implicated in the induction of fruit ripening in a diverse array of plants, are influenced by genetic and environmental factors, such as other plant hormones. Among these, salicylic acid (SA) and its derivative, acetylsalicylic acid (ASA), have been demonstrated to inhibit ethylene biosynthesis in fruit, yet the underlying regulatory mechanisms remain elusive. Here, we showed that treatment with exogenous ASA dramatically reduced ethylene production, as well as activities of ACC synthase (ACS) and ACC oxidase (ACO), in kiwifruit tissues. Comparative transcriptome analysis indicated the differential expression of ethylene biosynthetic genes (AdACS1/2 and AdACO5). A screen of transcription factors indicated that AdERF105L and AdWRKY29 were ASA-responsive regulators of AdACS1/2 and AdACO5, respectively. In addition to these genes, AdACS3 and AdACO3 were abundantly expressed in both ASA-treated and control tissues. AdACS3 protein was phosphorylated and stabilized by AdMPK16, a mitogen-activated protein kinase, while AdACO3 activity was enhanced by AdAP, an aspartic peptidase. Exogenous ASA downregulated AdMPK16 and AdAP, thereby influencing ethylene biosynthesis at a post-transcriptional level. These findings led us to propose a multidimensional system for inhibition of ethylene biosynthesis by ASA, inducing differential expression of some ethylene biosynthesis genes, as well as differential effects on protein activity on other targets.

A lead-free Cs2ZnCl4 perovskite nanocrystals fluorescent probe for highly selective detection of norfloxacin.

The abuse of antibiotics would seriously affect human health and has become of worldwide critical concern, thus it is urgent to develop an environmentally friendly and nontoxic fluorescent probe for antibiotics sensing. In this work, a lead-free Cs2ZnCl4 perovskite nanocrystals (PNCs) probe was fabricated for sensing norfloxacin (NOR) employing a modified ligand-assisted reprecipitation method. The prepared Cs2ZnCl4 PNCs probe had strong blue emission around 440 nm, and the characteristics of PNCs were systematically characterized by X-ray photoelectric spectroscopy (XPS), Fourier transforms infrared spectroscopy (FTIR), transmission electron microscope (TEM) and powder X-ray diffraction (XRD). The results revealed that the fluorescence intensity of the Cs2ZnCl4 PNCs was significantly enhanced after the introduction of norfloxacin. The Cs2ZnCl4 PNCs can be used as a fluorescent probe to selectively and sensitively detect norfloxacin in the concentration range from 0.2 to 50.0 µM, with a correlation coefficient (R2) of 0.9954 and the limit of detection (LOD, 3σ) of 0.1499 µM. The preparation and application of a lead-free perovskite fluorescent probe for norfloxacin would promote the application of perovskite fluorescent probes in biochemical assays.

Comparison of CT findings and histopathological characteristics of pulmonary cryptococcosis in immunocompetent and immunocompromised patients.

Pulmonary cryptococcosis (PC) is a common fungal infectious disease, and infection can occur in patients with any immune function. To better understand PC, we compared the CT findings and histopathological results in immunocompetent and immunocompromised patients. The clinical data of 68 patients with PC were collected retrospectively and divided into the immunocompetent group and immunocompromised group. The clinical characteristics, CT manifestations and histopathological characteristics of the two groups of patients were compared. Forty-two patients (61.8%) were immunocompetent, and 26 patients (38.2%) were immunocompromised. Compared with immunocompromised patients, 57.14% (24/42) of immunocompetent patients were asymptomatic (p = 0.002). Compared with immunocompetent patients, cough (14/26, 53.9%) and fever (13/26, 50.0%) were the main symptoms in immunocompromised patients (p = 0.044, p = 0.007). Nodular lesions (97.6%, 41/42) were the most common CT type in immunocompetent patients, and the CT characteristic was a single lesion (25/42, 59.5%); the main histopathological type was nodular fibrogranuloma (30/42, 71.4%), and the main histopathological characteristic was inflammatory granuloma (31/42, 73.81%) formed by macrophage phagocytosis of Cryptococcus. Consolidation (15/26, 57.7%) was more common in the CT type of immunocompromised patients. Multiple lesions (24/26, 92.31%), air bronchial signs (19/26, 73.081%) and cavities (9/26, 34.62%) were the main CT characteristics. The mucinous colloid type (19/26, 73.1%) was its main histopathological type, which was mainly characterized by a small amount of surrounding inflammatory cell infiltration (17/26, 65.4%). There were significant differences in the classification and characteristics of CT and pathology between the two groups (p < 0.05). Through the CT manifestations and histopathological characteristics of PC under different immune function states, it was found that immune function has a significant impact on the CT manifestations and histopathological characteristics of patients with PC.

The red flesh of kiwifruit is differentially controlled by specific activation-repression systems.

Anthocyanins are visual cues for pollination and seed dispersal. Fruit containing anthocyanins also appeals to consumers due to its appearance and health benefits. In kiwifruit (Actinidia spp.) studies have identified at least two MYB activators of anthocyanin, but their functions in fruit and the mechanisms by which they act are not fully understood. Here, transcriptome and small RNA high-throughput sequencing were used to comprehensively identify contributors to anthocyanin accumulation in kiwifruit. Stable overexpression in vines showed that both 35S::MYB10 and MYB110 can upregulate anthocyanin biosynthesis in Actinidia chinensis fruit, and that MYB10 overexpression resulted in anthocyanin accumulation which was limited to the inner pericarp, suggesting that repressive mechanisms underlie anthocyanin biosynthesis in this species. Furthermore, motifs in the C-terminal region of MYB10/110 were shown to be responsible for the strength of activation of the anthocyanic response. Transient assays showed that both MYB10 and MYB110 were not directly cleaved by miRNAs, but that miR828 and its phased small RNA AcTAS4-D4(-) efficiently targeted MYB110. Other miRNAs were identified, which were differentially expressed between the inner and outer pericarp, and cleavage of SPL13, ARF16, SCL6 and F-box1, all of which are repressors of MYB10, was observed. We conclude that it is the differential expression and subsequent repression of MYB activators that is responsible for variation in anthocyanin accumulation in kiwifruit species.

Molecular basis of the formation and removal of fruit astringency.

Astringency is a dry puckering mouthfeel mainly generated by the binding of tannins with proteins in the mouth. Tannins confer benefits such as resistance to biotic stresses and have antioxidant activity, and moderate concentrations of tannins can improve the flavor of fruits or their products. However, fruits with high contents of tannins have excessive astringency, which is undesirable. Thus, the balance of astringency formation and removal is extremely important for human consumption of fruit and fruit-based products. In recent years, the understanding of fruit astringency has moved beyond the biochemical aspects to focus on the genetic characterization of key structural genes and their transcriptional regulators that cause astringency. This article provides an overview of astringency formation and evaluation. We summarize the methods of astringency regulation and strategies and mechanisms for astringency removal, and discuss perspectives for future exploration and modulation of astringency for fruit quality improvement.

Transcription factors AcERF74/75 respond to waterlogging stress and trigger alcoholic fermentation-related genes in kiwifruit.

Kiwifruit plants have a fleshy, shallow root system which is sensitive to waterlogging stress, which results in a decrease in crop yield or even plants death. Although the waterlogging stress responses in kiwifruit have attracted much attention, the underlying molecular mechanism remains unclear. In this study, waterlogging led to drastic inhibition of root growth of 'Donghong' kiwifruit (Actinidia chinensis) plants grown in vitro, which was accompanied by significant elevation of endogenous acetaldehyde and ethanol contents. RNA-seq of roots of plants waterlogged for 0, 1 and 2 days revealed that a total of 149 genes were up- or down-regulated, including seven biosynthetic genes related to the glycolysis/gluconeogenesis pathway and 10 transcription factors. Analyses with real-time PCR, dual-luciferase assays and EMSA demonstrated that AcERF74 and AcERF75, two members of the ERF-VII subfamily, directly upregulated AcADH1 (alcohol dehydrogenase). Moreover, the overexpression of AcERF74/75 in transgenic calli resulted in dramatic increase of endogenous ethanol contents through the triggering of AcADH1 and AcADH2 expression. Although the AcPDC2 (pyruvate decarboxylase) expression was also enhanced in transgenic lines, the endogenous acetaldehyde contents showed no significant changes. These results illustrated that AcERF74/75 are two transcriptional activators on alcoholic fermentation related genes and are responsive to waterlogging stress in kiwifruit.

An ethylene-hypersensitive methionine sulfoxide reductase regulated by NAC transcription factors increases methionine pool size and ethylene production during kiwifruit ripening.

Ethylene plays an important role in regulating fruit ripening by triggering dynamic changes in expression of ripening-associated genes, but the functions of many of these genes are still unknown. Here, a methionine sulfoxide reductase gene (AdMsrB1) was identified by transcriptomics-based analysis as the gene most responsive to ethylene treatment in ripening kiwifruit. The AdMsrB1 protein exhibits a stereospecific activity toward the oxidative stress-induced R enantiomer of methionine sulfoxide (MetSO), reducing it to methionine (Met). Stable overexpression of AdMsrB1 in kiwifruit significantly increased the content of free Met and 1-aminocyclopropane-1-carboxylic acid (ACC), the immediate precursor of ethylene, and increased ethylene production. Dual-luciferase assays indicated that the AdMsrB1 promoter was not directly upregulated by ethylene treatment but was modulated by two ethylene-inducible NAM/ATAF/CUC transcription factors (AdNAC2 and AdNAC72) that bind directly to the AdMsrB1 promoter. Overexpression of AdNAC72 in kiwifruit not only enhanced AdMsrB1 expression, but also increased free Met and ACC content and ethylene production rates. This finding establishes an unexpected regulatory loop that enhances ethylene production and the concentration of its biosynthetic intermediates.

Highly selective and rapid detection of silver ions by using a "turn on" non-fluorescent cysteine stabilized gold nanocluster probe.

Cysteine is widely used as a stabilizer for the preparation of fluorescent gold nanoclusters (Au NCs) with different fluorescence properties. Herein, by using cysteine as a stabilizer and controlling the synthesis conditions, a new non-fluorescent cysteine stabilized gold nanocluster (Cys-Au NCs) probe was prepared and a new strategy for "turning on" the fluorescence of the Cys-Au NCs was studied for rapid and selective detection of silver ions. In this strategy, the addition of silver ions to non-fluorescent Cys-Au NCs solution could quickly induce a visible fluorescence "turn on" phenomenon in 30 s. Further studies indicated that this fluorescence "turn on" phenomenon is specific for silver ions and the "turn on" fluorescence intensity has a linear relationship with the amount of silver ions in the range from 3.0 to 30.0 µM. Therefore, the non-fluorescent Cys-Au NCs were applied to the detection of silver ions in environmental water samples and a limit of detection (LOD) of 0.26 µM was obtained. This research sheds light on new applications of Au NCs and proposes a simple, rapid, sensitive, and visual method for the detection of metal ions.

Preliminary Investigation and Imaging Analysis of Early Lung Cancer Screening Among Petroleum Workers in North China.

BACKGROUND: The detection rate of lung nodules has increased significantly among petroleum workers in North China since the low-dose CT (LDCT) screening has been widely carried out. What's more, the number of confirmed early lung cancers is increasing continuously. Therefore, a great deal of concern for the high risk of lung cancer has been shown among petroleum workers. PURPOSE: To improve the screening efficiency and maximize the benefits of the subjects, the current situation of LDCT lung cancer screening should be understood and the imaging characteristics of early lung cancer should be analyzed for petroleum workers in North China. MATERIALS AND METHODS: Firstly, the dynamic changes of LDCT early lung cancer screening for petroleum workers in North China were analyzed in recent years. Then, the survey data of 3121 petroleum workers was compared with that of 1868 non-petroleum workers, which was analyzed. Finally, 91 patients (129 nodular lung cancer) confirmed by pathology were retrospectively analyzed, and the data of which was compared with the clinical features obtained from survey data above. The imaging characteristics and related factors of different subtypes of lung adenocarcinoma were discussed and analyzed. RESULTS: Lung nodules were found in 810 cases (25.95%) out of 3121 petroleum workers; and the surgery was chosen by 42 patients, 38 of whom were confirmed as lung cancer. Compared with the data of screened petroleum workers, there were more older people and more females as well as a higher proportion of people with family malignancy history, and a lower proportion of smoking people in 91 patients with lung cancer. As the pathological grade of tumor nodules increased, the volume and diameter of nodules gradually increased, and the mean density, maximum density and standard deviation of density also increased (p < 0.001). The volume and diameter of nodules were positively correlated with ages (p < 0.05). CONCLUSION: The occurrence of lung adenocarcinoma is closely related to the family history of malignant tumors, and the constituent ratio of young women without a history of smoking increased significantly. At the same time, the quantitative information obtained by using CT images has important value in predicting its pathological subtypes.