Two Zn(II)‐based meta‐organic frameworks: Selective detection of antibiotics and treatment activity on age‐related macular degeneration by reducing inflammasome activation

Via utilizing the mixed‐ligand method, two novel Zn(II)‐containing meta‐organic frameworks with the chemical formula of {[Zn(L)(5‐HIP)]·H₂O}_n ( 1 ) and [Zn(L)(2,6‐NDC)]_n ( 2 ) were prepared under the solvothermal conditions by applying aromatic dicarboxylic acids ligands (5‐H₂HIP = 5‐hydroxyisophthalic acid; 2,6‐H₂NDC = 2,6‐naphthalenedicarboxylic acid) and 1,4‐bis(benzimidazol‐1‐yl)‐2‐butylene (L). Due to its good water stability as well as the strong luminescent emission around room temperature, complex 2 has the high selectivity and sensibility of fluorescence detection to the ceftriaxone sodium (a kind of antibiotic) with the detection limit up to ppm lever. The treatment activity of the compounds on age‐related macular degeneration was assessed and the specific mechanism was investigated. First of all, the inflammasome activation in the endothelial cells of retina was evaluated with western blot. In addition to this, the down‐stream production of the inflammasome activation was also measured with ELISA detection kit.     

Monitoring of circulating amino acids in patients with pancreatic cancer and cancer cachexia using capillary electrophoresis and contactless conductivity detection

Branched chain amino acids (BCAAs), alanine and glutamine are determined in human plasma by capillary electrophoresis with contactless conductivity detection (CE/C⁴D). The baseline separation of five amino acids from other plasma components is achieved on the short capillary effective length of 18 cm in 3.2 mol/L acetic acid with addition of 13% v/v methanol as background electrolyte. Migration times range from 2.01 min for valine to 2.84 min for glutamine, and LODs for untreated plasma are in the interval 0.7–0.9 μmol/L. Sample treatment is based on the addition of acetonitrile to only 15 μL of plasma and supernatant is directly subjected to CE/C⁴D. Circulating amino acids are measured in patients with pancreatic cancer and cancer cachexia during oral glucose tolerance test. It is shown that patients with pancreatic cancer and cancer cachexia syndrome exhibit low basal circulating BCAAs and glutamine levels and loss of their insulin-dependent suppression.     

Capillary electrophoresis method for analysis of inorganic and organic anions related to habitability and the search for life

In situ missions of exploration require analytical methods that are capable of detecting a wide range of molecular targets in complex matrices without a priori assumptions of sample composition. Furthermore, these methods should minimize the number of reagents needed and any sample preparation steps. We have developed a method for the detection of metabolically relevant inorganic and organic anions that is suitable for implementation on in situ spaceflight missions. Using 55 mM acetic acid, 50 mM triethylamine, and 5% glycerol, more than 21 relevant anions are separated in less than 20 min. The method is robust to sample ionic strength, tolerating high concentrations of background salts (up to 900 mM NaCl and 300 mM MgSO₄). This is an important feature for future missions to ocean worlds. The method was validated using a culture of Escherichia coli and with high salinity natural samples collected from Mono Lake, California.     

基于三苯胺的荧光探针设计、合成与应用研究进展

螺旋桨结构的三苯胺荧光团既能作为强的电子供体,又能作为潜在的聚集诱导发光(AIE)骨架.同时,三苯胺衍生物很容易通过简单的反应进行结构修饰,如醛基、氨基、硼酸基、卤素、乙炔基等取代的三苯胺能够发生缩合反应或偶联反应等,进一步功能化.因此,功能性三苯胺类化合物被广泛用于太阳能电池、荧光染料、固态发光材料和荧光探针的分子设计中.根据三苯胺基荧光探针的检测对象,将其分为阳离子、阴离子和中性小分子荧光探针三类,并从分子的结构和性能出发,重点综述了近五年来国内外三苯胺基荧光探针在分子设计、合成与检测应用方面的最新进展.展望未来,构建近红外发光和高量子效率的AIE荧光探针值得关注.     

Urea Detection of Electrochemical Transistor Sensors based on Polyanline (PANI)/MWCNT/Cotton Yarns

A cotton yarn biosensor based on electrochemical transistor functionalized with MWCNT and PANI was developed for the detection of urea. The transistors based on PANI/MWCNT/cotton yarns under optimized MWCNT concentration has been obtained, which exhibited high on/off current ratio, fast response time, and good operational stability. A transistor-based urea sensor was prepared from PANI/MWCNT/cotton yarns, which could monitor urea in the 1 nM–1 mM linear range with the correlation coefficient of 0.9716. Furthermore, the sensor showed superior reproducibility and high specificity. The practical applications of the proposed sensor were also confirmed. These results indicate the flexible transistor can be used as an efficient platform for biological detection in body fluids.     

Theoretical investigation of the interaction between the metal phthalocyanine [MPc]a(M = Sc,Ti, and V; a = –1, 0, and +1) complexes and formaldehyde

Formaldehyde (FA, CH₂O) is one of the toxic volatile organic compounds that cause harmful effects on the human body. In this work, the interaction of FA gas with metal phthalocyanine (MPc) molecules was studied by employing density functional theory calculations. A variety of [MPc]^a (M = Sc, Ti, and V; a = –1, 0, and +1) complexes were studied, and the electronic properties, interaction energies, and charge transfer properties of all of the studied molecules were systematically discussed. Among the studied complexes, the Sc and Ti phthalocyanines were more reactive toward the adsorption of FA gas. Moreover, it was revealed that the interaction of the [ScPc]⁺¹ and [TiPc]⁰ complexes with the CH₂O molecule was stronger, in which the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energy gap of 46% and 36% decreased after FA adsorption. The results indicated that the MPc-based materials may be a promising candidate for the detection of FA gas.     

Binding Characteristics Study of DNA based Aptamers for E. coli O157:H7

E. coli O157:H7 is a pathogenic bacterium producing verotoxins that could lead to serious complications such as hemolytic uremia syndrome. Fast detection of such pathogens is important. For rapid detection, aptamers are quickly gaining traction as alternative biorecognition molecules besides conventional antibodies. Several DNA aptamers have been selected for E. coli O157:H7. Nonetheless, there has not been a comparative study of the binding characteristics of these aptamers. In this work, we present a comprehensive analysis of binding characteristics including binding affinity (K_d) and binding capacity (B_max) of DNA-based aptamers for E. coli O157:H7 using qPCR. Our results show that aptamer E18R has the highest binding capacity to E. coli 157:H7 and the highest specificity over non-pathogenic E. coli strains K12 and DH5α. Our study also finds that the common biotin-tag modification at 5′ end typically changes the binding capacity significantly. For most of the selected aptamers, the binding capacity after a biotin-tag modification decreases. There exists a discrepancy in the binding capability between the selected aptamer and the aptamer used for detection. Our study also shows that a lower concentration of Mg²⁺ ions in the binding buffer leads to a decrease in the binding capacity of E17F and E18R, while it does not affect the binding capacity of S1 and EcoR1.     

Evaluation of Physiological Characteristics,Soluble Sugars,Organic Acids and Volatile Compounds in ‘Orin’ Apples (Malus domestica) at Different Ripening Stages

‘Orin’ is a popular apple cultivar, which has a yellow-green appearance, pleasant taste, and unique aroma. However, few studies on the fruit quality characteristics of ‘Orin’ apples have been reported before. In this study, changes of the physiological characteristics were measured at different ripening stages, and the soluble sugars and organic acids were determined by high-performance liquid chromatography (HPLC). Volatile compounds were identified using the headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography-mass spectrometry (GC-MS). During the fruit ripening, the ‘Orin’ apple fruit weight, size, and total soluble solid were gradually increased by contrast with the titratable acidity, and the firmness decreased. The content of four soluble sugars reached the maximum at the 180 days after full bloom (DAFB) stage. Malic acid was measured as the most abundant organic acid in ‘Orin’ apples. Ethyl butyrate, hexyl propanoate, hexyl acetate and butyl acetate belonging to esters with high odor activity values (OAVs) could be responsible for the typical aroma of ‘Orin’ apples. The aim of this work was to provide information on the flavor characteristics of ‘Orin’ apples and promote this apple cultivar for marketing and processing in the future.     

Bioactive Phenolic Compounds from Primula veris L.: Influence of the Extraction Conditions and Purification

Our experiments may help to answer the question of whether cowslip (Primula veris L.) is a rich source of bioactive substances that can be obtained by efficient extraction with potential use as a food additive. A hypothesis assumed that the type of solvent used for plant extraction and the individual morphological parts of Primula veris L. used for the preparation of herbal extracts will have key impacts on the efficiency of the extraction of bioactive compounds, and thus, the health-promoting quality of plant concentrates produced. Most analysis of such polyphenolic compound contents in extracts from Primula veris L. has been performed by using chromatography methods such as ultra-performance reverse-phase liquid chromatography (UPLC−PDA−MS/MS). Experiments demonstrated that the most effective extraction agent for fresh study material was water at 100 °C, whereas for dried material it was 70% ethanol. The richest sources of polyphenolic compounds were found in cowslip primrose flowers and leaves. The aqueous and ethanol extracts from Primula veris L. were characterized by a quantitatively rich profile of polyphenolic substances, and a high antioxidative potential. Selective extraction with the use of mild conditions and neutral solvents is the first step to obtaining preparations from cowslip primrose with a high content of bioactive substances.     

Effect of Botanical Extracts on the Growth and Nutritional Quality of Field-Grown White Head Cabbage (Brassica oleracea var. capitata)

Nutraceuticals and functional foods are gaining more attention amongst consumers interested in nutritious food. The consumption of foodstuffs with a high content of phytochemicals has been proven to provide various health benefits. The application of biostimulants is a potential strategy to fortify cultivated plants with beneficial bioactive compounds. Nevertheless, it has not yet been established whether the proposed higher plants (St. John’s wort, giant goldenrod, common dandelion, red clover, nettle, and valerian) are appropriate for the production of potential bio-products enhancing the nutritional value of white cabbage. Therefore, this research examines the impact of botanical extracts on the growth and nutritional quality of cabbage grown under field conditions. Two extraction methods were used for the production of water-based bio-products, namely: ultrasound-assisted extraction and mechanical homogenisation. Bio-products were applied as foliar sprays to evaluate their impact on total yield, dry weight, photosynthetic pigments, polyphenols, antioxidant activity, vitamin C, nitrates, micro- and macroelements, volatile compounds, fatty acids, sterols, and sugars. Botanical extracts showed different effects on the examined parameters. The best results in terms of physiological and biochemical properties of cabbage were obtained for extracts from common dandelion, valerian, nettle, and giant goldenrod. When enriched with nutrients, vegetables can constitute a valuable component of functional food.