Sorting out the value of spectroscopic tools to assess the Colletotrichum acutatum impact in olive cultivars with different susceptibilities

The olive tree (Olea europaea L.) can be affected by Colletotrichum acutatum, causing a loss of yield and quality of the final products, whilst the incidence of this fungal infection depends on several factors, including cultivar susceptibility. Thus, the effect of C. acutatum infection in cultivars displaying different susceptibilities to this fungal disease (‘Galega Vulgar’ ‐ susceptible, ‘Cobrançosa’ ‐ moderately susceptible, ‘Picual’ ‐ tolerant) has been assessed through spectrophotometric methods and HPLC, while the FTIR spectra of the cuticles have been concomitantly registered, resorting to the ATR accessory. With the support of multivariate analysis, these spectra allowed to discriminate olives with distinct infection times, besides retrieving evidences concerning the different susceptibility of each cultivar, while these observations were reinforced by the spectrophotometric and chromatographic methods. Furthermore, the assessment of the phenolic profile evidenced individual compounds in the distinct cultivars, so as their variations in response to the fungal infection.     

微波萃取–高效液相色谱荧光检测法测定食品包装用纸中11种荧光增白剂

采用微波萃取高效液相色谱荧光检测法测定食品包装用纸中11种荧光增白剂含量.将样品剪成约0.5 cm×0.5 cm的碎片,用体积分数为40％的乙腈水溶液(含体积分数为0.6％的三乙胺),于80℃微波萃取15 min,用高效液相色谱仪进行定性定量分析.采用Kromasil 100–5型C18柱(250 mm×4.6 mm,5μm)作为分析柱,荧光激发波长为362 nm,发射波长为410 nm,11种荧光增白剂可以较好的分离.11种荧光增白剂质量浓度线性范围为2～150μg/L,相关系数均不小于0.9996,方法检出限为0.1～0.2 mg/kg,定量限为0.3～0.6 mg/kg.样品加标平均回收率为86.0％～108.4％,相对标准偏差为0.4％～4.9％(n=6).该方法前处理简便,检测高效,灵敏度高.     

Theoretical investigation of the molecular structure and spectroscopic properties of oxicams

Nonsteroidal anti-inflammatory drugs (NSAIDs) are among the most frequently prescribed drugs and have multiple therapeutic uses. These drugs are predominantly used for the treatment of musculoskeletal diseases because of their analgesic, antipyretic, and antiplatelet activities. Oxicams constitute an interesting class of organic compounds and have been investigated in the search for new analgesic and anti-inflammatory drugs. In the present work, a theoretical investigation of the molecular structure and spectroscopic properties of a series of five oxicams in different solvents was performed using density functional theory (DFT) methods. The geometric optimizations of the oxicams were carried out using the M06 density functional and the CBSB7 basis set. The infrared data were all obtained at the same theoretical level. The UV-Vis absorption and NMR data of some oxicams were calculated using the DFT and CBSB3 basis sets. The analysis of structural parameters, particularly the bond length and spectroscopic data, indicated that interactions occurred between the hydrogen bond types for 4-meloxicam, isoxicam, and normeloxicam. Stereoelectronic interactions caused by the substitution of alkyl groups caused the bond lengths to elongate. Similarly, the substitution of heteroatoms, such as nitrogen, sulfur, or oxygen, increased the bond lengths and angular stresses.     

GC-MS Chemical Characterization and Antibacterial Effect of the Essential oil of Piper mosenii

Commercialized mouthwashes are generally expensive for the most financially vulnerable populations. Thus, several studies evaluate the antimicrobial potential of herbal products, such as essential oils, to reduce the activity of microorganisms in the mouth. The objective of this research was to carry out the chemical characterization and antibacterial activity of the essential oil of Piper mosenii (EOPm), providing data that enable the development of a low-cost mouthwash formulation aimed at vulnerable communities. The analysis of the antibacterial potential and modulator of bacterial resistance was verified by the microdilution method to determine the minimum inhibitory concentration-MIC. The chemical components were characterized by gas chromatography coupled to mass spectrometry, where 23 chemical constituents were detected, with α-pinene, being the major compound. The EOPm showed a MIC ≥ 1024 µg/mL for all bacterial strains used in the tests. When the EOPm modulating activity was evaluated together with chlorhexidine, mouthwash and antibiotics against bacterial resistance, the oil showed a significant synergistic effect, reducing the MIC of the products tested in combination, in percentages between 20.6% to 96.3%. Therefore, it is recommended to expand the tests with greater variation of EOPm concentration and the products used in this research, in addition to the evaluation of toxicity and in vivo tests, seeking the development of a possible formulation of mouthwash accessible to the vulnerable population.     

Utilization of Agro-Industrial Residues in the Rearing and Nutritional Enrichment of Zophobas atratus Larvae: New Food Raw Materials

Edible insects are a potential alternative food source of high feed conversion efficiency and protein content. Zophobas atratus is an edible insect that adapts to different diets, enabling sustainable rearing by adding value to by-products and agro-industrial residues. This study aimed to evaluate the performance and nutritional characterization of Zophobas atratus larvae fed with different proportions of grape residue. Physicochemical analysis of the diets and larvae (AOAC procedures), fatty acid profile (chromatographic techniques), metals and non-metals (inductively coupled plasma optical emission spectrometry), larval mass gain, feed conversion efficiency, and mortality rate were assessed. The replacement of 25% of the conventional diet with grape residue increased lipid, ash, and fiber contents and reduced protein, carbohydrates, and energy. It promoted greater mass gain, lower mortality rate, and reduced larval growth time by 51%. Among the replacements, 25% resulted in the second-highest content of calcium, sodium, magnesium, and zinc, and the lowest content of potassium and phosphorus in the larvae. The 100% replacement resulted in the highest amounts of C18:2n6 (27.8%), C18:3n3 (2.2%), and PUFA (30.0%). Replacing 25% of the conventional diet with grape residue is equivalent to the conventional diet in many aspects and improves several larvae performance indices and nutritional values.     

Lycopene,Mesoporous Silica Nanoparticles and Their Association: A Possible Alternative against Vulvovaginal Candidiasis?

Commonly found colonizing the human microbiota, Candida albicans is a microorganism known for its ability to cause infections, mainly in the vulvovaginal region known as vulvovaginal candidiasis (VVC). This pathology is, in fact, one of the main C. albicans clinical manifestations, changing from a colonizer to a pathogen. The increase in VVC cases and limited antifungal therapy make C. albicans an increasingly frequent risk in women’s lives, especially in immunocompromised patients, pregnant women and the elderly. Therefore, it is necessary to develop new therapeutic options, especially those involving natural products associated with nanotechnology, such as lycopene and mesoporous silica nanoparticles. From this perspective, this study sought to assess whether lycopene, mesoporous silica nanoparticles and their combination would be an attractive product for the treatment of this serious disease through microbiological in vitro tests and acute toxicity tests in an alternative in vivo model of Galleria mellonella. Although they did not show desirable antifungal activity for VVC therapy, the present study strongly encourages the use of mesoporous silica nanoparticles impregnated with lycopene for the treatment of other human pathologies, since the products evaluated here did not show toxicity in the in vivo test performed, being therefore, a topic to be further explored.     

Hetero-bimetallic Complex of a 2D Coordination Network Constructed by Sodium Ion and p-Sulfonatothiacalix[4]arene

A 2D coordination polymer built by sodium ion and water-soluble p-sulfonatothiacalix[4]arene of trivalent yttrium complex [Na（H2O）2Y（H2O）6（DMF） （p-sulfonatothiaca lix[4]arene）]-9H2O is reported. The complex belongs to the monoclinic system, space group P2 1/c, with a = 16.703（3）, b = 17.819（4）, c = 17.357（4）A, β = 106.23（3）°, Z = 4, V = 4960.0（17）A^3, Mr = 1304.08, Dc = 1.746 g/cm^3,μ= 1.624 mm^-1, F（000） = 2688, the final R = 0.0398 and wR = 0.1132 for 7534 observed reflections with I 〉 2σ（I）. One yttrium（Ⅲ） ion is coordinated by the thiacalixarene ligand via the sulfonato group, and also ligated by an oxygen atom of a DMF molecule occupying the cavity of thiacalixarene and six aqua ligands.     

实用化超导材料研究进展与展望

超导技术是21世纪具有重大经济和战略意义的高新技术,在国民经济诸多领域具有广阔的应用前景,如在超导弱电应用中的超导量子干涉器、滤波器;在超导强电应用中的电缆、限流器、电机、储能系统、变压器、磁体技术、医疗核磁共振成像、高能物理实验和高速交通输运等。实用化超导材料是超导技术发展的基础。目前,国际上发现的实用化超导材料主要有低温超导线材、铋系高温超导带材、YBCO涂层导体、MgB₂线带材以及新型铁基超导线带材。文章在简要介绍超导材料发展历程的基础上,重点综述了上述实用化超导材料制备及加工、性能和应用方面的最新研究进展,并对相关领域存在的问题及今后的发展作出展望。     

强Van der Pol振子的谐波与修正算法

引入谐波平衡近似解的符号运算与同伦延拓法,获得了强Van der Pol振子的解析近似极限环与稳定响应.为提高其近似精度,给出了谐波解的修正算法,并与数值模拟比较.结果表明,该算法非常精确可靠,是研究强非线性动力学系统的有效分析方法.