Search Results - (Author, Cooperation:L. Coppola)

2015-05-23

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Computer Science

Medicine

Natural Sciences in General

Physics

Animals ; *Food Chain ; Host Specificity ; Oceans and Seas ; Phylogeny ; Plankton/*classification/*physiology ; Platyhelminths/classification/physiology ; Sunlight ; *Symbiosis ; Viruses/classification

2018-11-28

Institute of Physics (IOP)

1757-8981

1757-899X

Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics

1089-7690

AIP Digital Archive

Physics

Chemistry and Pharmacology

A study of the water self-diffusion in polycrystalline lamellar systems, by pulsed field gradient spin-echo (PFG-SE) nuclear magnetic resonance (NMR) experiments, is reported here. Our analysis confirmed the validity of previous equations for bidimensional water self-diffusion in lamellar lyomesophases and clarified their applicability limits. Depending on the diffusion experimental time range, two different procedures can be built up; for wide amplitude windows, the experimental diffusion coefficients are correlated to the fraction of bound water, whereas for short times it has been possible to point out the "obstruction factor'' to diffusion. Experimental support for the theoretical findings was inferred by investigation of the lamellar mesophase of the binary system water/sodium-bis-2-ethylhexyl sulfosuccinate (AOT). It confirmed the existence of some defects in the lamellae at water concentration higher than 70 wt. %.

Electronic Resource

0009-8981

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Medicine

Electronic Resource

0006-291X

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Biology

Chemistry and Pharmacology

Physics

Electronic Resource

0006-291X

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Biology

Chemistry and Pharmacology

Physics

Electronic Resource

0009-2614

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Chemistry and Pharmacology

Physics

Electronic Resource

1435-1536

Key words Poly(ethylene oxide) ; poly(propylene oxide) ; poly(ethylene oxide) ; Micellar solutions ; Hexagonal and lamellar mesophases ; Pulsed field gradient spin-echo nuclear magnetic resonance experiments ; Micellar self-diffusion

Springer Online Journal Archives 1860-2000

Chemistry and Pharmacology

Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics

Abstract  Water-soluble poly(ethylene oxide)–poly(propylene oxide)–poly(ethylene oxide) (PEO–PPO–PPO) triblock copolymers are high-molecular-weight nonionic copolymers and form micellar solutions and liquid-crystalline mesophases in water. We studied the temperature dependence of polymer and water self-diffusion in solutions and lyotropic mesophases of the PEO13 PPO30 PEO13/water and PEO21 PPO47 PEO21/water binary systems. The self-diffusion measurements were performed by means of the pulsed field gradient spin-echo NMR method. The analysis of the water mobility was realised using “the obstruction factor” and “the two-site model”, which consider the reduction of the water self-diffusion due to the microstructure of the lyotropic aggregates and to the presence of one part of the solvent bound to the polymer aggregate surfaces. We calculated the water obstruction factors and the hydration numbers as a function both of the polymer composition and of the temperature. The results are compared with the data obtained in mesophases formed by classical surfactants.

Electronic Resource

1572-8838

Springer Online Journal Archives 1860-2000

Chemistry and Pharmacology

Electrical Engineering, Measurement and Control Technology

Abstract Experimental studies of mass transfer were conducted in stacked screens with a gas-liquid mixture flowing through the bed. Depending on the gas and liquid flow rates and on the geometric characteristics of the screens, different flow regimes are obtained. In the heterogeneous flow regime the gas phase controls mass transfer, meanwhile in the transition and bubbling flow regimes the influence of the liquid flow prevails. Appropriate dimensionless groups correlate the mass transfer coefficients with the pertinent variables for the different regimes.

Electronic Resource

0167-2738

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Physics

Electronic Resource

0002-9556

Psychology

APPARATUS

1432-1084

Key words: Duodenum ; Congenital anomalies ; gastrointestinal tract ; Magnetic Resonance imaging

Springer Online Journal Archives 1860-2000

Medicine

Abstract. The MR imaging appearance of a duodenal duplication cyst is reported. MR imaging confirmed the diagnosis suggested by ultrasound and CT scans. Fat-suppressed MR imaging before and after oral administration of the positive contrast agent Gd-DTPA was able to define tissue planes between the lesion and adjacent structures, such as the head of the pancreas, providing useful information for an accurate surgical approach. To our knowledge this is the first reported case of a duodenal duplication cyst in an adult demonstrated by MR imaging.

Electronic Resource

1432-1041

Key words Prostaglandin ; Type-2 diabetes mellitus ; Plasminogen activator inhibitor type-1

Springer Online Journal Archives 1860-2000

Chemistry and Pharmacology

Medicine

Abstract Objectives: Iloprost, an analogue of prostacyclin, is often utilised in subjects with diabetes mellitus complicated by macroangiopathy. Methods: The effects of iloprost infusion on plasminogen activator inhibitor type-1 (PAI-1), glucometabolic control and cardiovascular equilibrium in patients with type-2 diabetes mellitus and peripheral arterial occlusive disease were investigated. Thirteen (7 men/6 women) normal-weight, normotensive and non-smoker type-2 diabetic patients (63.8 ± 3.4 years, mean ± SD) with peripheral arterial occlusive disease, stage-II according to Fontaine classification, were enrolled. Eight (four men/four women) patients underwent three study designs, each separated by a 1-week interval: study I, infusion of iloprost (3 ng kg−1 min−1 for 5 h) for 1 day alone (short-term treatment); study II, infusion of saline (for 5 h) for 1 day (control treatment); study III, infusion of iloprost (3 ng kg−1 min−1 for 5 h) over a period of 28 days (long-term treatment). The remaining five (three men/two women) patients underwent study IV only, infusion of saline over a period of 28 days (placebo treatment). Plasma levels of glucose, plasminogen, PAI-1 activity and fibrinogen, blood pressure and heart rate were determined in all studies, while plasma insulin levels, blood HbA1c, walking distance and Winsor index only in studies III and IV. Results: Both short- and long-term treatments with iloprost significantly reduced PAI-1 activity (baseline vs end: 17.4 ± 1.9 AU/ml vs 15.0 ± 1.6 AU/ml, P 〈 0.02; 20.5 ± 7.6 AU/ml vs 7.9 ± 2.1 AU/ml, P 〈 0.002, respectively). Long-term treatment with iloprost significantly increased walking distance (baseline vs end: 325 ± 41 m vs 496 ± 52 m, P 〈 0.0001), but not Winsor index. Neither glucometabolic control nor cardiovascular equilibrium were affected by short- and long-term treatments with iloprost. Control and placebo treatments did not cause any significant modifications in the parameters evaluated. Conclusion: If confirmed by further investigations, the results of this pilot study suggest that iloprost, infused for both brief and long periods, is able to reduce the cardiovascular risk factor PAI-1, increases free walking capacity and does not affect glucometabolic control and blood pressure in type-2 diabetic patients complicated by macroangiopathy.

Electronic Resource

1439-0973

Springer Online Journal Archives 1860-2000

Medicine

Zusammenfassung 16 stationäre Patienten mit bakterieller Meningitis im Alter von 10 bis 76 (im Mittel 34,4) Jahren wurden mit Cefoperazon i.v. in einer Dosierung von 4,5 bis 9 g täglich behandelt. Ampicillin wurde in einem Fall zusätzlich während der letzten vier Therapietage gegeben, in einem Fall in den ersten fünf Tagen. Als Erreger wurden in neun FällenNeisseria meningitidis, in drei FällenHaemophilus influenzae und in je zwei FällenEscherichia coli undStreptococcus pneumoniae identifiziert. In 14 Fällen trat vollständige Heilung ein, die Erreger wurden eliminiert. Zwei Patienten konnten nach Versagen der Ersttherapie mit einer Alternativtherapie geheilt werden. Bei 11 Patienten wurden während der ersten Therapiewoche (am 1., 3., 5. und 7. Tag) die Spiegel von Cefoperazon in Serum und Liquor bestimmt. Gravierende Nebenwirkungen wurden nicht beobachtet.

Summary Sixteen hospitalized patients, aged between 10 and 76 years (mean: 34.3 years), with bacterial meningitis were treated i.v. with cefoperazone at daily doses of 4.5 g to 9 g. In two cases ampicillin was given in combination with cefoperazone during the last four days and the first five days of treatment, respectively. The following organisms were isolated:Neisseria meningitidis (n=9),Haemophilus influenzae (n=3),Escherichia coli (n=2),Streptococcus pneumoniae (n=2). Fourteen patients completely recovered from infection and the pathogens were eradicated; the treatment failed in only two patients and both were cured with alternative treatment. Furthermore, in 11 patients cefoperazone serum and CSF levels were determined four times during the first week of treatment (1st, 3rd, 5th and 7th days). No important side effects were recorded.

Electronic Resource

1435-1536

Ionic strength ; DPPC ; multilayer ; ESR ; DSC

Springer Online Journal Archives 1860-2000

Chemistry and Pharmacology

Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics

Abstract The effects of salinity on the lateral headgroup interactions of dipalmitoylphosphatidylcholine (DPPC) molecules in fully hydrated multilayers have been investigated by spin label electron spin resonance (ESR) spectroscopy and differential scanning calorimetry (DSC). By increasing the NaCl concentration from 0 to 3 M in the multilayers' dispersion medium, the ESR measurements performed with the 5-stearic acid spin label and di-tert-butyl-nitroxide show an increase in the orientational degree of order of the lipid molecules, mainly in the gel phase, and a decrease of the membrane permeability. An upward shift from 31.5° to 36.5°C and from 40.5° to 41.9°C of the pre- and main DPPC phase transition temperatures, respectively, is observed with 5-SASL, while slightly higher values are detected with DTBN. Small effects are evident on the properties of the liquid crystalline phase of the DPPC multilayers. The DSC measurements also reveal an upward shift of the pre- and main transition temperatures. The shifts, however, are more marked if compared to the ones observed with the ESR technique. The findings suggest an increase in the packing density of the DPPC molecules in the multilayers in presence of high salt concentration. Dehydration of the DPPC interfacial region with a variation of the lateral electrostatic interactions between phospholipid polar heads trigger the phenomena observed.

Electronic Resource

1435-1536

PFG-NMR ; self-diffusion ; micelles ; lyotropicmesophases ; hydration ; viscosity

Springer Online Journal Archives 1860-2000

Chemistry and Pharmacology

Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics

Abstract Studies by Pulsed Field Gradient NMR (PFG-NMR) methods and other physico-chemical experiments have been used to clarify the processes connected with water self-diffusion in mixtures formed by water and Triton TX-100. In micellar solutions the solvent diffusive trend is related to micelle hydration and, to a much less extent, to micelle size and shape. Hydration numbers from PFG-NMR are close to those obtained by viscosity experiments. In solution phases of the reversed kind, water in oil, water self-diffusion data suggest that aqueous domains are large and bicontinuous. Water self-diffusion in the hexagonal lyotropic mesophase has been interpreted by introducing a geometrydependent contraint, $$\tilde f$$ , termed “structural factor“, which is related to the parameters of the phase.

Electronic Resource