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81.
Lara La Pera Alfredo Liberatore Giuseppe Avellone Serena Fanara Giacomo Dugo Pasquale Agozzino 《Food additives & contaminants. Part A, Chemistry, analysis, control, exposure & risk assessment》2013,30(6):786-792
A simple, sensitive and accurate method for the analysis of furan in roasted coffee has been used based on headspace–solid-phase micro-extraction (HS–SPME) coupled to gas chromatography–mass spectrometry (GC–MS). The extraction was performed using 75-µm carboxen/polydimethylsiloxane fiber. Ionic strength, extraction time and temperature, and desorption time were assessed as the most important parameters affecting the HS–SPME procedure and d 4-furan was used as the internal standard. The linearity range was in the range 0.0075–0.486 ng g?1; the LOD and LOQ calculated using the signal-to-noise ratio approach were 0.002 and 0.006 ng g?1, respectively. The inter- and intra-day precision was 8 and 10%, respectively. The concentration of furan found in batches of roasted coffee powder different producing countries ranged from 57.3 to 587.3 ng g?1. The mean reduction in furan levels observed when brewing coffee by either infusion, using a moka pot or an expresso machine was 57, 67.5 and 63.3%, respectively. 相似文献
82.
Dr. Serena Massari Dr. Beatrice Mercorelli Dr. Luca Sancineto Dr. Stefano Sabatini Prof. Violetta Cecchetti Prof. Giorgio Gribaudo Prof. Giorgio Palù Prof. Christophe Pannecouque Prof. Arianna Loregian Prof. Oriana Tabarrini 《ChemMedChem》2013,8(8):1403-1414
Although human cytomegalovirus (HCMV) infection is mostly asymptomatic for immunocompetent individuals, it remains a serious threat for those who are immunocompromised, in whom it is associated with various clinical manifestations. The therapeutic utility of the few available anti‐HCMV drugs is limited by several drawbacks, including cross‐resistance due to their common mechanism of action, i.e., inhibition of viral DNA polymerase. Therefore, compounds that target other essential viral events could overcome this problem. One example of this is the 6‐aminoquinolone WC5 , which acts by directly blocking the transactivation of essential viral Early genes by the Immediate‐Early 2 (IE2) protein. In this study, the quinolone scaffold of the lead compound WC5 was investigated in depth, defining more suitable substituents for each of the scaffold positions explored and identifying novel, potent and nontoxic compounds. Some compounds showed potent anti‐HCMV activity by interfering with IE2‐dependent viral E gene expression. Among them, naphthyridone 1 was also endowed with potent anti‐HIV activity in latently infected cells. Their antiviral profile along with their innovative mechanism of action make these anti‐HCMV quinolones a very promising class of compounds to be exploited for more effective antiviral therapeutic treatment. 相似文献
83.
Lorenzo Berti Paola Serena D’Agostino Kelly Boeneman Igor L. Medintz 《Nano Research》2009,2(2):121-129
We demonstrate improved peptide linkers which allow both conjugation to biomolecules such as DNA and self-assembly with luminescent
semiconductor quantum dots. A hexahistidine peptidyl sequence was generated by standard solid phase peptide synthesis and
modified with the succinimidyl ester of iodoacetamide to yield a thiol-reactive iodoacetyl polyhistidine linker. The reactive
peptide was conjugated to dye-labeled thiolated DNA which was utilized as a model target biomolecule. Agarose gel electrophoresis
and fluorescence resonance energy transfer analysis confirmed that the linker allowed the DNA to self-assemble with quantum
dots via metal-affinity driven coordination. In contrast to previous peptidyl linkers that were based on disulfide exchange
and were thus labile to reduction, the reactive haloacetyl chemistry demonstrated here results in a more stable thioether
bond linking the DNA to the peptide which can withstand strongly reducing environments such as the intracellular cytoplasm.
As thiol groups occur naturally in proteins, can be engineered into cloned proteins, inserted into nascent peptides or added
to DNA during synthesis, the chemistry demonstrated here can provide a simple method for self-assembling a variety of stable
quantum dot bioconjugates.
相似文献
84.
Wilberforce SI Best SM Cameron RE 《Journal of materials science. Materials in medicine》2010,21(12):3085-3093
The application of bioresorbable polymer nanocomposites in orthopaedics offer the potential to address several of the limitations
associated with the use of metallic implants. Their enhanced biological performance has been demonstrated recently, but until
now relatively little work has been reported on their mechanical properties. To this end, the viscoelastic properties and
Tg of bioresorbable polylactide-co-glycolide/α-tricalcium phosphate nanocomposites were investigated by dynamic mechanical thermal
analysis. At room temperature of approximately 20°C, the storage moduli of the nanocomposites were generally higher than the
storage modulus of the unfilled polymer due to the stiffening effect of the nano-particles. However at physiological temperature
of approximately 37°C, the storage moduli of the nanocomposites decreased from 6.2 to 15.4% v/v nano-particle loadings. Similarly
the Tg of the nanocomposites also decreased from 6.2 to 15.4% v/v nano-particle loadings. These effects were thought to be due to
weak interfacial bonding between the nano-particles and polymer matrix. The storage moduli at 37°C and Tg increased from the minimum value when the particle loading was raised to 25.7 and 34.2% v/v loadings. SEM and particle size
distribution histograms showed that at these loadings, there was a broad particle size distribution consisting of nano-particles
and micro-particles and that some particle agglomeration was present. The consequent reduction in the interfacial area and
the number of weak interfaces presumably accounts for the rise in the storage modulus at 37°C and the Tg. 相似文献
85.
Qian Tang Roger Brooks Neil Rushton Serena Best 《Journal of materials science. Materials in medicine》2010,21(1):173-181
Plasma sprayed hydroxyapatite (HA) coatings on metallic prostheses have been used clinically in dentistry and orthopedics
since the mid 1980s. The coating properties are dependent on the spraying parameters. Since silicon-substituted hydroxyapatite
(SiHA) has been shown to offer improved bioactivity over phase pure HA, SiHA coatings have the potential for enhanced performance
in clinical application. In this study, phase pure HA and 0.8 wt% SiHA powders were synthesized with similar particle size
distribution and morphology. The powders were plasma sprayed onto Ti–6Al–4V substrates at 37 kW and 40 kW plasma gun input
power respectively. Four kinds of samples were prepared, HAC 37, HAC 40, SiHAC 37 and SiHAC 40. Materials characterization
showed that the coatings were of relatively high phase purity. In vitro cell culture demonstrated that human osteoblast cells
grew well on all samples, with the highest cell growth observed on SiHA coatings produced under the lower plasma gun input
power. 相似文献
86.
Effect of different land use on soil erosion in the pre-alpine fringe (North-East Italy): Ion budget and sediment yield 总被引:1,自引:0,他引:1
Data concerning ion budget from rainfall, runoff and soil loss measurements from two experimental plots located in North-East Italy, under different land cover (beech forest and vineyard, respectively), are reported. The chemical composition of rainfall, soil solution and runoff was determined to study the solute cycle within the soil, and the relationships between water, soil and vegetation. The forest ecosystem is more prone to acidification than the agricultural one; the elemental concentration of runoff water is considerably lower than that of soil solution. Comparing the ion input (rainfall) and output (runoff) at the two sites, it was possible to estimate the ion budget in the two soil-vegetation systems. The runoff amount and the ion balance are related to rainfall volumes and composition; the measured runoff under vineyard is 59% in comparison to the one under beech. The soil loss at the two experimental sites (170 kg/ha and 132 kg/ha, respectively) is quite limited. The measured sediment yield of the two catchments (0.24-0.19 t/ha/year, respectively) is consistent with data reported for native forests of western Europe. Comparing rainfall and soil loss at the two sites proved that maintenance of some form of land cover is advisable if runoff and erosion are to be minimized. In the European context, where the most important consequences of erosion are sedimentation downstream and loss of productivity, this type of data will yield valuable information for the understanding of such processes occurring at catchment scale, and will help policy-makers develop appropriate programs for the territory safeguard. 相似文献
87.
Serena Bianchi Sara Bernardi Antonella Mattei Loredana Cristiano Leonardo Mancini Diana Torge Giuseppe Varvara Guido Macchiarelli Enrico Marchetti 《International journal of molecular sciences》2022,23(9)
Several types of deproteinised bovine bone mineral (DBBM) are available on the market, and each one is obtained with a thermic and chemical process that can differ, achieving different results. Currently, several protocols using low temperature are suggested to reduce the possible particle crystallisation during the production process. This study aimed to evaluate the biomorphological reaction of periodontal fibroblast cultures in contact with different DBBM particles treated with a low-temperature protocol (Thermagen®) and without exposure to sodium hydroxide (NaOH). Morphological evaluation was performed using light, confocal laser, and scanning electron microscopy, and the biological reaction in terms of proliferation was performed using an XTT proliferation assay at 24 h (T1), 72 h (T2), and 7 days (T3). The morphological analysis highlighted how the presence of the materials stimulated a change in the morphology of the cells into a polygonal shape, surface reactions with the thickening of the membrane, and expression of actin. In particular, the morphological changes were appreciable from T1, with a progressive increase in the considered morphological characteristics at T2 and T3 follow-ups. The proliferation assay showed a statistical significance between the different experimental materials and the negative control in T2 and T3 follow-ups. The post hoc analysis did not reveal any differences between the materials. In conclusion, the grafts obtained with the low-temperature extractions protocol and not exposed to NaOH solution showed positive morphological reactions with no differences in the sizes of particles. 相似文献
88.
Costanza Renata Neri Serena Scapaticci Francesco Chiarelli Cosimo Giannini 《International journal of molecular sciences》2022,23(9)
Obesity is one of the greatest health challenges affecting children of all ages and ethnicities. Almost 19% of children and adolescents worldwide are overweight or obese, with an upward trend in the last decades. These reports imply an increased risk of fat accumulation in hepatic cells leading to a series of histological hepatic damages gathered under the acronym NAFLD (Non-Alcoholic Fatty Liver Disease). Due to the complex dynamics underlying this condition, it has been recently renamed as ‘Metabolic Dysfunction Associated Fatty Liver Disease (MAFLD)’, supporting the hypothesis that hepatic steatosis is a key component of the large group of clinical and laboratory abnormalities of Metabolic Syndrome (MetS). This review aims to share the latest scientific knowledge on MAFLD in children in an attempt to offer novel insights into the complex dynamics underlying this condition, focusing on the novel molecular aspects. Although there is still no treatment with a proven efficacy for this condition, starting from the molecular basis of the disease, MAFLD’s therapeutic landscape is rapidly expanding, and different medications seem to act as modifiers of liver steatosis, inflammation, and fibrosis. 相似文献
89.
Laura Mannarino Lara Paracchini Federica Pezzuto Gheorghe Emilian Olteanu Laura Moracci Luca Vedovelli Irene De Simone Cristina Bosetti Monica Lupi Rosy Amodeo Alessia Inglesi Maurizio Callari Serena Penpa Roberta Libener Sara Delfanti Antonina De Angelis Alberto Muzio Paolo Andrea Zucali Paola Allavena Giovanni Luca Ceresoli Sergio Marchini Fiorella Calabrese Maurizio DIncalci Federica Grosso 《International journal of molecular sciences》2022,23(10)
90.
Francesca Lucibelli Maria Carmen Valoroso Serena Aceto 《International journal of molecular sciences》2022,23(15)
DNA methylation is an epigenetic modification of the genome involved in the regulation of gene expression and modulation of chromatin structure. Plant genomes are widely methylated, and the methylation generally occurs on the cytosine bases through the activity of specific enzymes called DNA methyltransferases. On the other hand, methylated DNA can also undergo demethylation through the action of demethylases. The methylation landscape is finely tuned and assumes a pivotal role in plant development and evolution. This review illustrates different molecular aspects of DNA methylation and some plant physiological processes influenced by this epigenetic modification in model species, crops, and ornamental plants such as orchids. In addition, this review aims to describe the relationship between the changes in plant DNA methylation levels and the response to biotic and abiotic stress. Finally, we discuss the possible evolutionary implications and biotechnological applications of DNA methylation. 相似文献