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Biomedical subjects

M Bini

Publications and source records attributed to M Bini.

At least 19 recordsLinked to original sources
PubMed2006

Structural and spectroscopic properties of pure and doped Ba6Ti2Nb8O30 tungsten bronze.

Pure and doped Ba(6)Ti(2)Nb(8)O(30) (BTN), obtained by substituting M = Cr, Mn, or Fe on the Ti site (Ba(6)Ti(2-x) M(x)Nb(8)O(30), x = 0.06 and 0.18) and Y and Fe on the Ba and Ti sites, respectively (Ba(6-x)Y(x)Ti(2-x)Fe(x)Nb(8)O(30), x= 0.18), are synthesized. The influence of cation doping on the local structure, the cation oxidation state, and the possible defect formation able to maintain the charge neutrality are investigated by spectroscopic (electron paramagnetic resonance (EPR) and micro-Raman), structural (X-ray powder diffraction) and transport (impedance spectroscopy, thermoelectric power) measurements, in the temperature range of 300-1200 K in air and N(2) flow. Starting from the valence state of the doping ions (Fe(3+), Cr(3+), and Mn(2+)), determined by EPR, and from thermoelectric power measurements, evidencing a negative charge transport, different charge-compensating defect equilibria, based on the creation of positive electron holes or oxygen vacancies and electrons, are discussed to interpret the conductivity results.

Journal Article↗
PubMed2006

Cation distribution in LiMgVO4 and LiZnVO4: structural and spectroscopic study.

The room temperature cation occupancy in LiMgVO(4) and LiZnVO(4) crystallographic sites is obtained by means of the combined use of X-ray powder diffraction (XRPD), (7)Li and (51)V magic angle spinning nuclear magnetic resonance (MAS NMR), and micro-Raman measurements. In the LiMgVO(4) Cmcm orthorhombic structure, the 4c (C(2)(v) symmetry) tetrahedral vanadium site is fully ordered; on the contrary, the Li 4c tetrahedral site and the 4b (C(2)(h) symmetry) Mg octahedral site display about 22% of reciprocal cationic exchange. Higher cationic disorder is observed in LiZnVO(4): the three cations can distribute on the three tetrahedral and distinct sites of the R-3 structure. XRPD and MAS NMR analysis results highly agree for what concerns vanadium ion distribution on the three cationic sites (about 25, 26, and 47%). From the full profile fitting of XRPD patterns with the Rietveld method, it is also obtained that Li(+) displays a slightly preferred occupation of the T1 position (approximately 55%) and Zn(2+) of the T2 position (approximately 46%). The vibrational spectra of the two compounds are characterized by different peak positions and broadening of the Raman modes, reflecting the cation distribution and the local vibrational unit distortion. A comparison is also made with recent Raman results on Li(3)VO(4). High temperature XRPD measurements rule out possible structural transitions up to 673 K for both compounds.

Journal Article↗
PubMed2005

Transport and structural properties of pure and Cr doped Li3VO4.

This study deals with the effects of 5 and 10% chromium additions on the transport and structural properties of Li3VO4. The Cr substitution is easily obtained without impurity phases and does not affect the room- and high-temperature host crystal structure, as evidenced by X-ray powder diffraction and micro-Raman analysis. The EPR signals are interpreted in terms of quantified amounts of Cr ions in 5+ and 3+ valence states. Suitable 7Li and 51V MAS NMR spectra simulations agree with the EPR results about the relative amount of Cr5+ and Cr3+ ions substituted in V5+ and Li+ sites, respectively. The Cr3+ presence on Li site, also suggested by Raman results and Rietveld refinements, requires Li vacancies to maintain the charge neutrality. The p-type conductivity, suggested by the positive thermoelectric power coefficients, significantly increases by the cation doping up to an order of magnitude.

Journal Article↗
PubMed2004

Energetics of midvelocity emissions in peripheral heavy ion collisions at Fermi energies.

Peripheral and semiperipheral collisions have been studied in the system 93Nb+93Nb at 38A MeV. The evaporative and midvelocity components of the light charged particle and intermediate mass fragment emissions have been carefully disentangled. In this way it was possible to obtain the average amount not only of charge and mass, but also of energy, pertaining to the midvelocity emission, as a function of an impact parameter estimator. This emission has a very important role in the overall balance of the reaction, as it accounts for a large fraction of the emitted mass and for more than half of the dissipated energy. As such, it may give precious clues on the microscopic mechanism of energy transport from the interaction zone toward the target and projectile remnants.

Journal Article↗
PubMed2004

Long-term outcome after senning operation for transposition of the great arteries.

BACKGROUND: The Senning operation for transposition of the great arteries (TGA) was first introduced by Senning in 1959 and was revived by Quaegebeur et al. in the late 1970s, thus becoming the intervention of choice for the correction of TGA in many centers. HYPOTHESIS: The purpose of this study was to evaluate the long-term follow-up of a group of patients undergoing surgery with the Senning procedure for TGA. METHODS: From November 1978 to November 1987, 73 consecutive patients underwent the Senning operation. The 70 survivors had an average follow-up of 19 years (16-25 years). RESULTS: (1) Cardiac rhythm: with time there was a progressive decrease in stable sinus rhythm (60% after 20 years) and a progressive increase of supraventricular tachyarrhythmias requiring therapy (10% after 20 years). (2) Right ventricular function: 20% of the patients had reduced ejection fraction. (3) Late mortality: in the last 12 years of follow-up years there were two sudden deaths (2.8%). (4) Functional status: 80% of patients were in NYHA class I, 17% in class II, and 3% in class III. CONCLUSIONS: Our results confirm that the patients who undergo the Senning procedure have a progressive loss of sinus rhythm, an increase in active arrhythmias, and other important adverse outcomes such as late sudden death and a decrease in right ventricular function; however, most patients (93% in our series) are alive and in good functional status.

Adolescent↗
PubMed2002

Long-term evaluation of esophageal function in patients treated at birth for esophageal atresia.

Dysphagia, gastroesophageal reflux (GER) and esophageal metaplasia are reported with various incidence in the long term follow-up of patients treated at birth for esophageal atresia (EA). To evaluate the long term outcomes 26 patients treated at birth for EA with Tracheo Esophageal Fistula (TEF) were examined 8-28 (mean 15.8) years later by clinical evaluation, including barium meal, fiberoptic upper GI endoscopy, 24 hour ambulatory two-channel pH-monitoring and stationary esophageal manometry. 50% of patients complained of dysphagia. Mild esophagitis was found in 20% of patients but GER was detected in only 16.7% of the cases. By morphological X-ray, esophageal anomalies were detected in 31% of cases without significant functional relevance. Hundred percent of patients had a disorganized peristaltic esophageal activity and a low amplitude of the esophageal contractions was observed in 58% of them. In our series, esophageal dismotilty seems to be the main consequence of EA without any relevant disturbance of normal nutritional habit.

Adolescent↗
PubMed2002

Intermediate mass fragment emission pattern in peripheral heavy-ion collisions at Fermi energies.

The emission pattern in the v(perp)-v(par) plane of intermediate mass fragments with Z = 3--7 (IMF) has been studied in the collision 116Sn+ 93Nb at 29.5A MeV as a function of the total kinetic energy loss of the reaction. This pattern shows that for peripheral reactions most IMF's are emitted at velocities intermediate between those of the projectile- and target-like products. Coulomb trajectory calculations show that these IMF's are produced in the interaction zone in a short time interval at the end of the target-projectile interaction.

Journal Article↗
PubMed2001

Polymorphism of rac-5,6-diisobutyryloxy-2-methylamino-1,2,3,4-tetrahydro-naphthalene hydrochloride (CHF 1035). I. Thermal, spectroscopic, and X-ray diffraction properties.

The polymorphism of rac-5,6-diisobutyryloxy-2-methylamino-1,2,3,4-tetrahydro-naphthalene hydrochloride (CHF 1035) was investigated. Three different crystal forms (Form I, Form II, and Form III) were obtained by recrystallization procedures from common organic solvents. The polymorphs were characterized by Raman and carbon-13 nuclear magnetic resonance ((13)C NMR) spectroscopy, in solution and in solid state (cross polarization-magic angle spinning), powder X-ray diffractometry, and thermal methods (differential scanning calorimetry, hot stage microscopy, and thermogravimetry). Moreover, the diffraction patterns of Form I, collected at controlled temperatures, gave evidence of the presence of two reversible structural rearrangements at approximately 60 and approximately 75 degrees C. These structural variations were confirmed by the results obtained by differential scanning calorimetry and hot stage microscopy techniques. The analysis of the Raman spectra allowed the identification of peculiar absorption bands for each polymorph. Form III was the stable crystal form at room temperature as determined by the basis of slurry conversion method.

Calorimetry, Differential Scanning↗
PubMed2001

Electromagnetic field monitoring and control systems: state-of-the-art and work-in-progress.

The development of EMF monitoring and control systems unquestionably represents one of the major innovations in the range of methodologies for evaluating, through measurement, the so-called environmental electromagnetic pollution. The interest recently shown by ARPA and municipal and provincial councils for setting up electromagnetic field monitoring and control systems has created significant developments in the field under examination. This paper attempts to provide a complete overview of the technical possibilities provided by electromagnetic field monitoring and control systems in the environment and their possible applications. Equipment currently available and under development is described, as well as the most significant work-in-progress in this sector. In the near future, several monitoring systems will be proposed and set up by municipalities and provinces, or directly by telecommunications companies. For this reason, it is more than ever necessary that agreement be reached at a national level to define a unified methodological and operating approach to enable monitoring data from different sources to be compared.

Electromagnetic Fields↗
PubMed2001

[Peristomal laparocele: particular indications for the use of prosthetic materials].

The authors report the case of a female patient suffering from colic neoplasm and a vast peristomal laparocele, the long-term outcome of a rectal amputation that the patient underwent at a young age. After colic resection, a vast area of surgical mesh in dacron was modelled and positioned in a retromuscular scat, thus allowing the hernia pathology to be resolved relatively simply, owing to its particular location-in correspondence with a preternatural anus-until not long ago this would have represented an absolute contraindication to the use of prosthetic materials. A precise surgical approach, marked by a scrupulous respect for aseptic conditions, is essential in these circumstances owing to the persistent risk of septic complications.

Aged↗
PubMed2000

Dielectric properties of wood from 2 to 3 GHz.

Many applications of microwave energy to wooden materials have been developed in the last few decades, both for treatment and for diagnostic purposes. All these applications require a reliable estimation of the permittivity of the wood species of interest, which is the physical parameter of crucial importance in the absorption of electromagnetic energy. This paper presents results obtained in the dielectric characterization of five wood species in the frequency range from 2 to 3 GHz, including the ISM frequency of 2.45 GHz. Permittivity was measured by an open-ended coaxial-line probe of new design on wood samples conditioned at several moisture levels. The influence of the natural variability of wood characteristics on the measured permittivity was also investigated by a suitable experimental setup consisting of a poplar table including both sapwood and heartwood regions. Finally, a theoretical discussion on the meaning of a scalar measurement on anisotropic dielectrics is conducted in terms of an isotropic-equivalent permittivity, which is related to the permittivity tensor of the dielectric material.

Electricity↗
PubMed1998

Long-term efficacy of endoscopic stenting in patients with stricture of the biliary anastomosis after orthotopic liver transplantation.

BACKGROUND AND STUDY AIMS: The choledocho-choledochostomy (CCS) stricture is one of the most frequent complications occurring after liver transplantation. Endoscopic retrograde cholangiography (ERCP) is the most sensitive method used to define the presence and narrowness of the stricture. Endoscopic stenting of the strictured anastomosis could provide an effective alternative to the surgical intervention. PATIENTS AND METHOD: ERCP was performed in 36 of 210 patients with liver transplantation and acute cholestasis or jaundice: in 15 cases biliary anastomotic stricture was found. These patients were endoscopically treated by long-term stenting of the common bile duct (CBD) (1 year) and followed up for more than 12 months after stent removal. RESULTS: In all cases the stenting procedure resolved the biliary obstruction syndrome within 7 days. At the end of the stenting period the CCS was dilated enough to allow adequate bile flow and absence of cholestasis. Moreover, in most patients (10) the anastomosis was kept patient for more than 1 year after stent removal, whereas only two patients had stricture recurrence and needed endoscopic restenting. Four patients dropped out of the study, respectively because of liver rejection (two), acute liver failure (one) and myocardial infarction (one). One patient who developed a stone of the transplanted CBD underwent surgical intervention. CONCLUSIONS: According to our data, the endoscopic stenting of the CBD might be considered as the first choice procedure in the setting of the biliary anastomotic strictures occurring after liver transplantation. It has proved to be safe and effective, avoiding the need for more invasive surgery, which in any case should be considered for nonresponsive patients.

Adult↗
PubMed1998

An electrical model of biological tissues undergoing hyperaemia.

Tissue hyperaemia is a physiological consequence of the temperature increase that follows, for example, the absorption of electromagnetic or ultrasound power in clinical diathermy. Diathermy, as well as other physical therapies (for example massotherapy), affects the local blood content of tissues through various mechanisms (vasoconstriction/dilatation, opening/closing of precapillary sphincters). A method for evaluating hyperaemia in superficial and medium-depth tissues has been recently proposed, which is based on four-electrode impedance measurements. A microcirculation model has also been developed to describe the hyperaemic effects of local diathermic therapy. This paper describes an electrical model of the tissues in hyperaemic conditions which allows us to correlate electrical impedance measurements to microcirculation modifications.

Biophysical Phenomena↗
PubMed1997

Hyperaemia evaluation in clinical diathermy by four-electrode impedance measurements.

The four-electrode electrical impedance measurement technique is proposed for the evaluation of the hyperaemia variation in tissues treated by diathermic therapy. An impedance meter suitable for such measurements is described, and an electrical model of the heated tissues, concerning the impedance variation during diathermy and its relation with hyperaemia, is presented. The occurrence of the substantial contribution of blood to the overall transverse impedance is demonstrated by comparing the experimental results with those arising from a 2D electrical/thermal model of the treated tissues. A two-admittance model is proposed to explain the electrical behaviour of the tissues treated by diathermy. The model allows us to separate the impedance violation due to the temperature dependence of tissue conductivity from that due to the change of tissue blood content. The results of preliminary measurements of tissue impedance on healthy volunteers treated by electromagnetic diathermy are presented and discussed, showing the feasibility of impedance detection of hyperaemia variations inside tissues.

Body Temperature↗
PubMed1996

The effect of endoscopic sclerotherapy of esophageal varices on the development of gastric varices.

BACKGROUND AND STUDY AIMS: The effect of sclerotherapy of esophageal varices on the development of gastric varices is a controversial question. The aim of the present study was to evaluate prospectively the presence and development of gastric varices as a consequence of esophageal variceal sclerotherapy. PATIENTS AND METHODS: We prospectively studied 227 patients, all of whom had liver cirrhosis at the time of the first bleeding episode due to esophageal varices. All patients were treated with emergency endoscopic sclerotherapy, and further courses of sclerotherapy to eradicate the varices were given at seven-day intervals for three sessions, and then every fifteen days until eradication was complete. At the time of inclusion in the study, patients were divided in two groups: group A, with initial gastric varices, and group B, without any gastric varices initially. RESULTS: Group A included 138 patients (60.8%), in 99 of whom (71.7%) disappearance of the gastric varices was observed. In 63 cases (63.6%) the varices were eliminated during the sclerotherapy treatment, before the eradication of esophageal varices; in 36 cases (36.4%), the gastric varices disappeared after the eradication of the esophageal varices. Group B included 89 patients (32.9%); in 78 of them (87.6%), no appearance of gastric varices was observed, while in 11 (12.4%), gastric varices appeared. CONCLUSION: From these data, it can be concluded that sclerotherapy of esophageal varices cannot be a determinant factor either for the appearance of gastric varices or for their subsequent risk of bleeding.

Adult↗