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61.
Thermodynamic interactions in the ethane-1,2-diol (1) + 1,2-dimethoxyethane(2) + water (3) ternary system have been investigated in terms of the excessmolar volume, derived from density measurements at 19 different temperaturesfrom –10;dg to 80;dgC. Fourteen three-component mixtures have been considered,covering the entire composition range. The excess molar volumes are discussedin terms of conformational changes induced in each component by the presenceof another one. The results obtained support the hypothesis of the absence of anythree-component complex adducts under all experimental conditions investigated.  相似文献   
62.
The separation of three pairs of enantiomeric herbicides has been successfully achieved by capillary electrophoresis at two different pH values in the presence of cyclodextrin derivatives previously synthesized in our laboratory. Two of these derivatives constitute a new class of receptor, the hemispherodextrins, in which a trehalose capping moiety is bonded to β-cyclodextrin. Because of their peculiar structure hemispherodextrins have very promising characteristics and the low receptor concentration required to achieve separation deserves particular interest.  相似文献   
63.
64.
We study backward stochastic differential equations (BSDEs) for time-changed Lévy noises when the time-change is independent of the Lévy process. We prove existence and uniqueness of the solution and we obtain an explicit formula for linear BSDEs and a comparison principle. BSDEs naturally appear in control problems. Here we prove a sufficient maximum principle for a general optimal control problem of a system driven by a time-changed Lévy noise. As an illustration we solve the mean–variance portfolio selection problem.  相似文献   
65.
Co-Salox complexes are suitable catalysts for the reduction of prochiral α,β-unsaturated esters. These ligands can be prepared in a single step from available and inexpensive materials, thus representing an easily accessible alternative to previously reported Co-catalysts. NaBH4 is employed as reducing agent in the presence of EtOH as proton source, leading to the stereoselective formation of chiral esters, amides, and nitriles in up to 99 % yield and 96.5 : 3.5 er. The concentration of the reductant counter cation (Na+) and the solvent polarity have been shown to correlate with reactivity and enantioselectivity, suggesting that a relatively complex mechanistic manifold is in place.  相似文献   
66.
Nitinol self-expanding stents are used for the endovascular management of peripheral artery diseases of the popliteal artery, which is located behind the knee joint. Unfortunately, the complex kinematics of the artery during the leg flexion leads to severe loading conditions, favouring the mechanical failure of the stent, calling for a specific biomechanical analysis. For this reason, in the present study we reconstruct by medical image analysis the patient-specific popliteal kinematics during leg flexion, which is subsequently exploited to compute the mechanical response of a stent model, virtually implanted in the artery by structural finite element analysis (FEA). The medical image analysis indicates a non-uniform configuration change of the artery during the leg flexion, leading to an increase of the vessel curvature above the knee. The computed mechanical response of the stent reflects the non-uniform configuration change of the artery as after the flexion the average stress is higher in the part of the stent located above the knee. Although the proposed analysis is limited to a case-study, it shows the capability of patient-specific FEA simulations to compute the mechanical response of a stent model subjected to the complex and severe loading conditions of the popliteal artery during leg flexion.  相似文献   
67.
In this work we present a systematic study of Japanese sword hand-guards (tsuba) carried out by means of non-invasive techniques using neutrons. Several tsuba from different periods, belonging to the Japanese Section of the Stibbert Museum, were analysed using an innovative approach to characterise the bulk of the samples, coupling two neutron techniques, namely Time of Flight Neutron Diffraction (ToF-ND) and Nuclear Resonance Capture Analysis (NRCA). The measurements were carried out on the same instrument: the INES beam-line at the ISIS spallation pulsed neutron source (UK). NRCA analysis allows identifying the elements present in the sample gauge volume, while neutron diffraction is exploited to quantify the phase distribution and other micro-structural parameters of the metal specimen. The results show that all samples are made of high-quality metal, either steel or copper alloy, with noticeable changes in composition and working techniques, depending on the place and time of manufacturing.  相似文献   
68.
Cannabidiol (CBD) is a biologically active compound present in the plants of the Cannabis family, used as anticonvulsant, anti-inflammatory, anti-anxiety, and more recently, anticancer drug. In this work, its use as a new self-assembly inducer in the formation of nanoparticles is validated. The target conjugates are characterized by the presence of different anticancer drugs (namely N-desacetyl thiocolchicine, podophyllotoxin, and paclitaxel) connected to CBD through a linker able to improve drug release. These nanoparticles are formed via solvent displacement method, resulting in monodisperse and stable structures having hydrodynamic diameters ranging from 160 to 400 nm. Their biological activity is evaluated on three human tumor cell lines (MSTO-211H, HT-29, and HepG2), obtaining GI50 values in the low micromolar range. Further biological assays were carried out on MSTO-211H cells for the most effective NP 8B, confirming the involvement of paclitaxel in cytotoxicity and cell death mechanism  相似文献   
69.
Hydroxyapatite (HA) is the main inorganic mineral that constitutes bone matrix and represents the most used biomaterial for bone regeneration. Over the years, it has been demonstrated that HA exhibits good biocompatibility, osteoconductivity, and osteoinductivity both in vitro and in vivo, and can be prepared by synthetic and natural sources via easy fabrication strategies. However, its low antibacterial property and its fragile nature restricts its usage for bone graft applications. In this study we functionalized a MgHA scaffold with gold nanorods (AuNRs) and evaluated its antibacterial effect against S. aureus and E. coli in both suspension and adhesion and its cytotoxicity over time (1 to 24 days). Results show that the AuNRs nano-functionalization improves the antibacterial activity with 100% bacterial reduction after 24 h. The toxicity study, however, indicates a 4.38-fold cell number decrease at 24 days. Although further optimization on nano-functionalization process are needed for cytotoxicity, these data indicated that Au-NRs nano-functionalization is a very promising method for improving the antibacterial properties of HA.  相似文献   
70.
1,2,3-triazoles are versatile building blocks with growing interest in medicinal chemistry. For this reason, organic chemistry focuses on the development of new synthetic pathways to obtain 1,2,3-triazole derivatives, especially with pyridine moieties. In this work, a novel series of 1,5-disubstituted-1,2,3-triazoles functionalized with pyrimidine nucleobases were prepared via 1,3-dipolar cycloaddition reaction in a regioselective manner for the first time. The N1-propargyl nucleobases, used as an alkyne intermediate, were obtained in high yields (87–92%) with a new two-step procedure that selectively led to the monoalkylated compounds. Then, FeCl3 was employed as an efficient Lewis acid catalyst for 1,3-dipolar cycloaddition between different aryl and benzyl azides and the N1-propargyl nucleobases previously synthesized. This new protocol allows the synthesis of a series of new 1,2,3-triazole derivatives with good to excellent yields (82–92%). The ADME (Absorption, Distribution, Metabolism, and Excretion) analysis showed good pharmacokinetic properties and no violations of Lipinsky’s rules, suggesting an appropriate drug likeness for these new compounds. Molecular docking simulations, conducted on different targets, revealed that two of these new hybrids could be potential ligands for viral and bacterial protein receptors such as human norovirus capsid protein, SARS-CoV-2 NSP13 helicase, and metallo-β-lactamase.  相似文献   
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