Photocontrollable DNA Walker-Based Molecular Circuit for the Tunable Detection of MicroRNA-21 Using Metal-Organic Frameworks as Label-Free Fluorescence Tags.

Tunable detection of microRNA is crucial to meet the desired demand for sample species with varying concentrations in clinical settings. Herein, we present a DNA walker-based molecular circuit for the detection of miRNA-21 (miR-21) with tunable dynamic ranges and sensitivity levels ranging from fM to pM. The phosphate-activated fluorescence of UiO-66-NH metal-organic framework nanoparticles was used as label-free fluorescence tags due to their competitive coordination effect with the Zr atom, which significantly inhibited the ligand-to-metal charge transfer.

d-Penicillamine@Ag/Cu Nanocluster-Based Fluorescent Nanoneuron for Logic Screening Phosphonate-Type Organophosphate Pesticides and Steganographically Encrypting Information.

Organophosphate pesticides are used in agriculture due to their high effectiveness and low persistence in eradicating insects and pests. However, conventional detection methods encounter the limitation of undesired detection specificity. Thus, screening phosphonate-type organophosphate pesticides (OOPs) from their analogues, phosphorothioate organophosphate pesticides (SOPs), remains a challenge.

A dual-signal fluorescent colorimetric tetracyclines sensor based on multicolor carbon dots as probes and smartphone-assisted visual assay.

The widespread presence of tetracyclines in the environment has raised concerns about the potential risks to ecosystems and human health. The ratiometric fluorescence sensor for detecting tetracyclines was developed using europium-doped carbon dots (Eu-CDs) as probes under alkaline conditions. The sensing mechanism of sensor for tetracyclines was considered as inner filter effect (IFE), antenna effect (AE), and self-quenching effect (SQE).

A novel thiolysis-high-performance liquid chromatography method for the determination of proanthocyanidins in grape seeds.

A novel thiolysis-high-performance liquid chromatography method for the quantitative determination of total proanthocyanidins and the mean degree of polymerization in grape seeds has been developed. Following thiolysis with formic acid and benzyl mercaptan, reaction products were separated and purified. Three proanthocyanidin monomers and three derivatives were obtained and their structures were identified by liquid chromatography-mass spectrometry, FTIR spectroscopy, and NMR spectroscopy.

A ratiometric fluorescent sensor for tetracyclines detection in meat based on pH-dependence of targets with lanthanum-doped carbon dots as probes.

Although some ratiometric fluorescent sensors have been reported to detect tetracyclines, most of ratiometric fluorescent sensors were established based on europium ion with a narrow linear range. In this work, a ratiometric fluorescent sensor for tetracyclines detection was established based on the dual-emission lanthanum-doped carbon dots (La-CDs) as probes combining with the characteristic pH-response of tetracyclines. The fluorescence intensity of tetracyclines will be enhanced in high pH, and the emission peak of tetracyclines overlapped with the peak of probes.

Nostoc flagelliforme capsular polysaccharides from different culture conditions improve hyperlipidemia and regulate intestinal flora in C57BL/6J mice to varying degrees.

Two capsular polysaccharides (WL-CPS-1 and GLU-CPS-1) purified from Nostoc flagelliforme under normal and mixotrophic culture conditions were used to investigate the hypolipidemic activity and effect on intestinal flora in C57BL/6J mice respectively. Their molecular weight and monosaccharide composition have been determined in previous studies. They both improved the lipid level by affecting the expression of lipid metabolism genes.

Cu enhanced fluorescent Ag nanoclusters with tunable emission from red to yellow and the application for Ag sensing.

In this work, the water-soluble fluorescent Ag nanoclusters (DPA@Ag NCs) were first prepared based on D-Penicillamine (DPA) as a stabilizer, however, the fluorescence quantum yield (QY) of DPA@Ag NCs was very low, then Cu was employed to improve the fluorescence QY and the doped Ag nanoclusters with Cu (DPA@Ag/Cu NCs) were obtained. The study showed that the QY increased fourfold and the emission of nanoclusters changed from red to yellow after addition of Cu. The reasonfor change of fluorescent properties wasattributed to the change of self-assembly structures caused by adding Cu into reaction system, leading to the aggregation-induced emission enhancement (AIEE) effect and enhancing the band gap (Eg) between the HOMO and LUMO in nanoclusters.

Comparisons of Functional Properties of Polysaccharides from under Three Culture Conditions.

is an edible cyanobacterium with excellent food and herbal values. It has been used as food in China for more than 2000 years. Many studies have been focused on improving the yield and bioactivity of polysaccharides although these have ignored the functional properties.

ROS Is a Factor Regulating the Increased Polysaccharide Production by Light Quality in the Edible Cyanobacterium Nostoc flagelliforme.

To explore the regulatory factor of light quality affecting exopolysaccharide (EPS) production, transcriptome analysis of Nostoc flagelliforme cells exposed to red light (R), blue light (B), and mixed light (B/R = 15:7) (BR) with white fluorescent light as control was performed. The differentially expressed genes mainly enriched in carbohydrate metabolism and energy metabolism. Significant enrichment in the oxidation-reduction process and energy metabolism indicated that intracellular redox homeostasis was disrupted.

Comparative proteomic analysis of Nostoc flagelliforme reveals the difference in adaptive mechanism in response to different ultraviolet-B radiation treatments.

Nostoc flagelliforme is a pioneer organism in the desert and highly resistant to ultraviolet B (UV-B) radiation, while the involved adaptive mechanism has not been fully explored yet. To elucidate the responsive mechanism, two doses of UV-B radiation (low: 1 W/m and high: 5 W/m) were irradiated for 6 h and 48 h, respectively, and their effects on global metabolism in N. flagelliforme were comprehensively investigated.

Effect of culture conditions on the physicochemical properties and antioxidant activities of polysaccharides from Nostoc flagelliforme.

Three polysaccharides (WL-CPS-1, NaCl-CPS-1 and Glu-CPS-1) were extracted and purified from Nostoc flagelliforme under normal, salt stress and mixotrophic culture conditions respectively. Their physicochemical properties and antioxidant activities were investigated. WL-CPS-1, NaCl-CPS-1 and Glu-CPS-1 chemical composition differed in sugar and uronic acid contents, and they were composed of nine constituent monosaccharides and one uronic acid with different ratios, with the average molecular weights of 1.

The physiological responses of terrestrial cyanobacterium to different intensities of ultraviolet-B radiation.

is a pioneer organism in the desert and exerts important ecological functions. The habitats of are characterized by intense solar radiation, while the ultraviolet B (UV-B) tolerance has not been fully explored yet. To evaluate the physiological responses of to UV-B radiation, three intensities (1 W m, 3 W m and 5 W m) were used, and the changes in photosynthetic pigments, cell morphology, mycosporine-like amino acids (MAAs) synthesis and cell metabolism were comparatively investigated.

The relationship between monosaccharide composition of extracellular polysaccharide and activities of related enzymes in Nostoc flagelliforme under different culture conditions.

The relationship between monosaccharide composition of Nostoc flagelliforme extracellular polysaccharide (EPS) and activities of EPS synthesis enzymes under various carbon sources, nitrogen sources and light culture condition was investigated. Culture conditions showed significant influences on both monosaccharide composition and related enzyme activities. Under both carbon and nitrogen sources conditions, mannose mole percentage was increased with the increase of initial mole ratio of C/N and positively related to fructose-1, 6-bisphosphatase activity, and glucuronic acid and galactose mole percentages were positively correlated with UDP-glucose dehydrogenase, while arabinose and rhamnose mole percentages were negatively associated with UDP-glucose pyrophosphorylase.

Rapid Detection of Small Molecule Metabolites in Serum of Hepatocellular Carcinoma Patients Using Ultrafast Liquid Chromatography-Ion Trap-Time of Flight Tandem Mass Spectrometry.

A method was developed for analyzing broad spectrum small molecule metabolites in the serum of hepatocellular carcinoma (HCC) patients based on ultrafast liquid chromatography-ion trap-time of flight tandem mass spectrometry (UFLC-IT-TOF MS). Serum samples were collected from 80 HCC patients and healthy persons. After pretreatment process for protein precipitation, the supernatant was analyzed with the UFLC-IT-TOF MS to obtain information on the metabonomics of small molecules.

Complete Genome Sequence of HKU8 Isolated from Human Blood.

Members of the genus are strongly associated with human diseases. We present here the complete genome sequence of HKU8, which consists of one circular chromosome. The strain characteristically contains various genes encoding for enzymes involved in arylamidase utilization.

Feasibility of Pb phytoextraction using nano-materials assisted ryegrass: Results of a one-year field-scale experiment.

The effect of the combined application of nano-hydroxyapatite (NHAP) or nano-carbon black (NCB) on the phytoextraction of Pb by ryegrass was investigated as an enhanced remediation technique for soils by field-scale experiment. After the addition of 0.2% NHAP or NCB to the soil, temporal variation of the uptake of Pb in aboveground parts and roots were observed.

[Synthesis and characterization of non fluorescent ZnS nano clusters].

Zinc sulfide nano clusters were synthesized and characterized. A kind of method using zinc sulfide nanoparticles cluster cation exchange reaction(CX) to detect trace biological molecules was established. Non fluorescent ZnS nanoparticles (NCCs) were synthesized and characterized.

Comparison of bacterial community structures of terrestrial cyanobacterium Nostoc flagelliforme in three different regions of China using PCR-DGGE analysis.

Filamentous Nostoc flagelliforme form colloidal complex, with beaded cells interacting with other bacteria embedded in the complex multilayer sheath. However, the species of bacteria in the sheath and the interaction between N. flagelliforme and associated bacteria remain unclear.

Metabolomic approach to optimizing and evaluating antibiotic treatment in the axenic culture of cyanobacterium Nostoc flagelliforme.

The application of antibiotic treatment with assistance of metabolomic approach in axenic isolation of cyanobacterium Nostoc flagelliforme was investigated. Seven antibiotics were tested at 1-100 mg L(-1), and order of tolerance of N. flagelliforme cells was obtained as kanamycin > ampicillin, tetracycline > chloromycetin, gentamicin > spectinomycin > streptomycin.

[Identification of geographical origins of rice with pattern recognition technique by near infrared spectroscopy].

A rapid method was developed for discrimination of the geographical origins of rice with pattern recognition technique by near infrared spectrocopy (NIRS). A total of 119 geography signs product Xiangshui rice samples and 90 rice (Non-Xiangshui rice) samples produced from other places were analyzed by NIRS. After first derivative and smooth processing, principal component analysis (PCA) was used to reduce the dimensionality of the spectral data.

[Determination of trace sodium ion in high purity water by graphite furnace atomic absorption spectrometry].

The present paper studied on the determination of trace Na+ in high purity water by graphite furnace atom absorption spectrometry. A method of directly on-line concentrating samples in graphite furnace, multiple charging, ashing, then determining once by directly charging into pools of graphite furnace, was set up. The goal of concentrating samples and avoiding contamination as well as raising sensitivity were finally achieved.

[Quantitatively determining trace elements Co and Bi in gelatin by inductively coupled plasma atomic emission spectrometry method--applying IEC model to correct the spectral interference of Fe to Co].

By ICP-AES, the authors established the method to quantitatively determine the trace elements Co and Bi in gelatin. The authors processed the unknown sample with wet digesting method. Trace elements in gelatin could be quantitatively determined at the same time.

The distribution patterns of trace elements in the blood and organs in a rabbit experimental model of copper pollution and study of haematology and biochemistry parameters.

In a rabbit model of five copper overfeeding, we investigated the distribution pattern of trace elements of copper [Cu], zinc [Zn], chromium [Cr], manganese [Mn], and selenium [Se] in blood serum, red cell, and whole blood and in the organs: brain, gallbladder, liver, intestines, heart, kidney, lung, and spleen. Furthermore, their haematology and biochemistry parameters as well as feed consumption and weight development were also performed in this study. Changes in trace element concentrations were determined by contrast and control group.