135 research outputs found
Moser's estimates for degenerate Kolmogorov equations with non-negative divergence lower order coefficients
We prove Lloc 1e estimates for positive solutions to the following degenerate second order partial differential equation of Kolmogorov type with measurable coefficients of the form 11i,j=1m0 02xjavax.xml.bind.JAXBElement@14c7905daij(x,t) 02xjavax.xml.bind.JAXBElement@41a3b5feu(x,t)+ 11i,j=1Nbijxj 02xjavax.xml.bind.JAXBElement@21dceba6u(x,t) 12 02tu(x,t)++ 11i=1m0bi(x,t) 02iu(x,t) 12 11i=1m0 02xjavax.xml.bind.JAXBElement@638b72d3ai(x,t)u(x,t)+c(x,t)u(x,t)=0 where (x,t)=(x1,\u2026,xN,t)=z is a point of RN+1, and 1 64m0 64N. (aij) is a uniformly positive symmetric matrix with bounded measurable coefficients, (bij) is a constant matrix. We apply the Moser's iteration method to prove the local boundedness of the solution u under minimal integrability assumption on the coefficients
Rapid temperature-assisted synthesis of nanoporous γ-cyclodextrin-based metal–organic framework for selective CO2 adsorption
Preparation and Carbonization of Glucose and Pyromellitic Dianhydride Crosslinked Polymers
In this work, four types of nanosponges were prepared from pyromellitic dianhydride (PMDA) and D-glucose (GLU) with different molar ratios (1.5:1, 2:1, 2.5:1 and 3:1). The obtained PMDA/GLU nanosponges were then pyrolyzed at 800 °C for 30 min under N2 gas flow. The prepared polymeric nanosponges were investigated by FTIR spectroscopy, elemental and thermogravimetric analyses to unravel the role played by the different molar ratio of the precursors in the formation of the polymer. The pyrolyzed nanosponges were investigated by means of porosity measurements, X-ray diffraction analysis, Raman spectroscopy and high-resolution transmission electron microscopy. Notably, no significant correlation of the amounts of used precursors with the porous texture and structure was evidenced. The results corroborate that PMDA and GLU can be easily combined to prepare nanosponges and that the carbon materials produced by their pyrolysis can be associated with glassy carbons with a microporous texture and relatively high surface area. Such hard carbons can be easily obtained and shrewdly used to segregate relatively small molecules and organic contaminants; in this study methylene blue adsorption was investigated
Effect of the cross-linking density on the swelling and rheological behavior of ester-bridged β-cyclodextrin nanosponges
New poly(β-cyclodextrin)/poly(vinyl alcohol) electrospun sub-micrometric fibers and their potential application for wastewater treatments
Chemical characterization of non-psychoactive Cannabis sativa L. extracts, in vitro antiproliferative activity and induction of apoptosis in chronic myelogenous leukaemia cancer cells
In this study, extracts from non-psychoactive Cannabis sativa L. varieties were characterized by means of ultra high-performance liquid chromatography coupled with high-resolution mass spectrometry (UHPLC-HRMS) and their antiproliferative activity was assessed in vitro. The human chronic myelogenous leukaemia cell line K562 was chosen to investigate the mechanism of cell death. The effect on the cell cycle and cell death was analysed by flow cytometry. Proteins related to apoptosis were studied by western blotting. Mechanical properties of cells were assessed using the Micropipette Aspiration Technique (MAT). The results indicated that the cannabidiol (CBD)-rich extract inhibited cell proliferation of K562 cell line in a dose-dependent manner and induced apoptosis via caspase 3 and 7 activation. A significant decrease in the mitochondrial membrane potential was detected, together with the release of cytochrome c into the cytosol. The main apoptotic markers were not involved in the mechanism of cell death. The extract was also able to modify the mechanical properties of cells. Thus, this hemp extract and its pure component CBD deserve further investigation for a possible application against myeloproliferative diseases, also in association with other anticancer drugs
Botanical sources, chemistry, analysis, and biological activity of furanocoumarins of pharmaceutical interest
The aim of this work is to provide a critical review of plant furanocoumarins from different points of view, including their chemistry and biosynthetic pathways to their extraction, analysis, and synthesis, to the main biological activities found for these active compounds, in order to highlight their potential within pharmaceutical science. The limits and the possible improvements needed for research involving these molecules are also highlighted and discussed
Late complications of robot-assisted radical cystectomy with totally intracorporeal urinary diversion
Introduction and objectives: To evaluate late complications in a large cohort of patients undergoing robot-assisted radical cystectomy (RARC) with totally intracorporeal urinary diversion (ICUD). Materials and methods: We prospectively enrolled patients who underwent RARC and ICUD between August 2012 and June 2019. We excluded patients with Ejection fraction < 36%, retinal vasculopathy, ventriculoperitoneal shunts, and those treated without curative intent. All complications and their onset date have been recorded, defined, and graded according to Clavien classification adapted for radical cystectomy. Results: 210 patients were included, 76% of whom were men, with a mean age of 62 years. Urinary diversions used were Padua Ileal Bladder (PIB) in 80% of cases, and ileal conduit (IC) in 20% of patients (generally older and with more comorbidity). The mean follow-up was 30 ± 22 months. The stenosis rate of uretero-ileal anastomosis was 14%, while a reduction in eGFR (≥ 20%) was observed in about half of the cases. UTIs occurred in 37% of the patients, especially in the first 12 months. Only 2% of patients had bowel occlusion, whereas incisional hernia, lymphocele, and systemic events (metabolic acidosis and major cardiovascular events) occurred respectively in 20%, 10%, and 1% of cases. Conclusions: Our study evaluates first late complications in a cohort of patients who underwent RARC with ICUD. These data are encouraging and in line with findings from a historical series of open radical cystectomy (ORC). This study is a further step in supporting RARC as a safe and effective surgical option for the treatment of muscle-invasive bladder cancer (MIBC) in tertiary referral centers
Artificial Intelligence Can Guide Antibiotic Choice in Recurrent UTIs and Become an Important Aid to Improve Antimicrobial Stewardship
Background: A correct approach to recurrent urinary tract infections (rUTIs) is an important pillar of antimicrobial stewardship. We aim to define an Artificial Neural Network (ANN) for predicting the clinical efficacy of the empiric antimicrobial treatment in women with rUTIs. Methods: We extracted clinical and microbiological data from 1043 women. We trained an ANN on 725 patients and validated it on 318. Results: The ANN showed a sensitivity of 87.8% and specificity of 97.3% in predicting the clinical efficacy of empirical therapy. The previous use of fluoroquinolones (HR = 4.23; p = 0.008) and cephalosporins (HR = 2.81; p = 0.003) as well as the presence of Escherichia coli with resistance against cotrimoxazole (HR = 3.54; p = 0.001) have been identified as the most important variables affecting the ANN output decision predicting the fluoroquinolones-based therapy failure. A previous isolation of Escherichia coli with resistance against fosfomycin (HR = 2.67; p = 0.001) and amoxicillin-clavulanic acid (HR = 1.94; p = 0.001) seems to be the most influential variable affecting the output decision predicting the cephalosporins- and cotrimoxazole-based therapy failure. The previously mentioned Escherichia coli with resistance against cotrimoxazole (HR = 2.35; p < 0.001) and amoxicillin-clavulanic acid (HR = 3.41; p = 0.007) seems to be the most influential variable affecting the output decision predicting the fosfomycin-based therapy failure. Conclusions: ANNs seem to be an interesting tool to guide the antimicrobial choice in the management of rUTIs at the point of care
Star-shaped Magnetic-plasmonic Au@Fe3O4 nano-heterostructures for photothermal therapy
Here, we synthesize a Au@Fe3O4 core@shell system with a highly uniform unprecedented star-like shell morphology with combined plasmonic and magnetic properties. An advanced electron microscopy characterization allows assessing the multifaceted nature of the Au core and its role in the growth of the peculiar epitaxial star-like shell with excellent crystallinity and homogeneity. Magnetometry and magneto-optical spectroscopy revealed a pure magnetite shell, with a superior saturation magnetization compared to similar Au@Fe3O4 heterostructures reported in the literature, which is ascribed to the star-like morphology, as well as to the large thickness of the shell. Of note, Au@Fe3O4 nanostar-loaded cancer cells displayed magneto-mechanical stress under a low frequency external alternating magnetic field (few tens of Hz). On the other hand, such a uniform, homogeneous, and thick magnetite shell enables the shift of the plasmonic resonance of the Au core to 640 nm, which is the largest red shift achievable in Au@Fe3O4 homogeneous core@shell systems, prompting application in photothermal therapy and optical imaging in the first biologically transparent window. Preliminary experiments performing irradiation of a stable water suspension of the nanostar and Au@Fe3O4-loaded cancer cell culture suspension at 658 nm confirmed their optical response and their suitability for photothermal therapy. The outstanding features of the prepared system can be thus potentially exploited as a multifunctional platform for magnetic-plasmonic applications
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