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F Sorrentino

Publications and source records attributed to F Sorrentino.

At least 19 recordsLinked to original sources
PubMed2006

Long-lived BLOCH oscillations with bosonic sr atoms and application to gravity measurement at the micrometer scale.

We report on the observation of Bloch oscillations on the unprecedented time scale of several seconds. The experiment is carried out with ultracold bosonic 88Sr atoms loaded into a vertical optical standing wave. The negligible atom-atom elastic cross section and zero angular momentum in the ground state makes 88Sr an almost ideal Bose gas, insensitive to typical mechanisms of decoherence due to thermalization and external stray fields. The small size of the system enables precision measurements of forces at micrometer scale. This is a challenge in physics for studies of surfaces, Casimir effects, and searches for deviations from Newtonian gravity predicted by theories beyond the standard model.

Journal Article↗
PubMed2006

Modì: a new mobile instrument for in situ double-pulse LIBS analysis.

Laser-induced breakdown spectroscopy (LIBS) is a promising technique for in situ elemental analysis. A new mobile instrument for LIBS analysis, developed in a collaboration between Marwan Technology s.r.l. and the Applied Laser Spectroscopy Laboratory in Pisa, is presented, and some applications of it and results from it are outlined. The innovative experimental set-up, based on the use of two suitably retarded laser pulses and a standardless analysis procedure, which overcomes problems related to matrix effects, greatly improves the potential of this technique for accurate quantitative analysis.

Journal Article↗
PubMed2006

Laser sources for precision spectroscopy on atomic strontium.

We present a new laser setup designed for high-precision spectroscopy on laser cooled atomic strontium. The system, which is entirely based on semiconductor laser sources, delivers 200 mW at 461 nm for cooling and trapping atomic strontium from a thermal source, 4 mW at 497 nm for optical pumping from the metastable P23 state, 12 mW at 689 nm on linewidth less than 1 kHz for second-stage cooling of the atomic sample down to the recoil limit, 1.2 W at 922 nm for optical trapping close to the "magic wavelength" for the 0-1 intercombination line at 689 nm. The 689 nm laser was already employed to perform a frequency measurement of the 0-1 intercombination line with a relative accuracy of 2.3 x 10(-11), and the ensemble of laser sources allowed the loading in a conservative dipole trap of multi-isotopes strontium mixtures. The simple and compact setup developed represents one of the first steps towards the realization of a transportable optical standards referenced to atomic strontium.

Lasers↗
PubMed2006

The usefulness of clinical indexes in the evaluation of cardiovascular risk in non cardiac surgery.

AIM: The preoperative cardiac evaluation of a patient who undergoes noncardiac surgery is a very important problem, particularly for diagnostic tools used. Aim of this study is to test the usefulness of 4 most used clinical indexes for the evaluation of cardiovascular risk in the management of patients who undergo noncardiac surgery. METHODS: The study is based on a retrospective analysis of a group of 45 patients, who underwent extracardiac surgery in biennium 2002-2004. The cardiovascular risk scores of Goldman, Detsky, Lee and Eagle were used; a comparison among the different scores was done. RESULTS: Six out of our 45 patients had perioperative cardiovascular complications, and 4 of them died. The Eagle and Lee scores were more predictive than Goldman and Detsky ones. About the 13 echocardiographic tests recorded, no one of them modified the patient preoperative risk. CONCLUSIONS: In the preoperative assessment of risk, the Eagle score was more useful than the others ones and improved the negative predictive value of the Goldman and Detsky scores. The preventive application of the clinical indexes allows optimizing the preoperative stratification of the risk, limiting the request of useless examinations and offering to the patient a well appropriated preoperative management, reducing the incidence of complications.

Adult↗
PubMed2005

Coherent multiwave heterodyne frequency measurement of a far-infared laser by means of a femtosecond laser comb.

We demonstrate the possibility of using a femtosecond laser to measure with high accuracy the frequency of a far-infrared (FIR) monochromatic source, such as an optically pumped molecular laser, by generating in a suitable mixer a signal in the radio-frequency region at the frequency difference between n steps of a femtosecond comb and the FIR source. All the couples of modes lying a distance of n steps from one another contribute coherently to the heterodyne signal. The technique has been tested up to 670 GHz.

Journal Article↗
PubMed2003

Ventricular arrhythmias in hypertensive patients with mild metabolic alterations.

BACKGROUND: Ventricular arrhythmias (VA) are prevalent in hypertensives, as well as in diabetics and dyslipidemics. The aim of our study is to evaluate if alterations in glucose or lipid metabolism increase the risk of VA in hypertensive patients. METHODS: Sixty-eight patients (24 males, 44 females, aged 45-78), with mild-moderate hypertension, were divided into 2 groups: group A (n=24) normoglycemic and normolipemic, and group B (n=44) with serum cholesterol >220 mg% and/or triglycerides >165 mg% and/or glucose >110 mg%. Patients with clinical or ECG signs of ischemia or kaliemia <3.5 mEq/l, were not admitted to the study. After a 15-days pharmacological wash-out, 24-hour Holter ECG and echocardiography were performed on all patients. RESULTS: Ventricular ectopic beats (VEB) were found in 66% of group A and 100% of group B (difference =34%, 95% C.I. =18-50%). VEB were less severe in group A (Lown's class 1-2), while group B had VEB ranging from class 1 to 5. Left ventricular hypertrophy (LVH) was found in 33% of group A and in 72.7% of group B, and was not closely correlated to VA. Group B patients with LVH had more severe VA (4 A, 4 B and 5 Lown's class). CONCLUSIONS: Hyperglycemia and/or dyslipidemia, even mild, seem to increase the risk of VA in the hypertensive patient with or without LVH. It suggests that 24 hour Holter ECG may be useful to select, among patients with metabolic alterations, those at high risk for VA.

Aged↗
PubMed2002

Cardiovascular involvement in thalassaemic patients with pseudoxanthoma elasticum-like skin lesions: a long-term follow-up study.

BACKGROUND: Congenital haemolytic anaemia may be associated with pseudoxanthoma elasticum (PXE)-like clinical manifestations. METHODS: The cardiovascular system of 14 homozygous and double heterozygous beta-thalassaemia patients with skin and retinal vessel alterations similar to those in genetic PXE was analysed over a period of 12 years and compared with that of 13 relatives (five sets of parents, one single parent, two thalassaemic brothers), and that of the control group composed of 16, age- and sex-matched, thalassaemic patients. RESULTS: All patients with clinical PXE-like skin lesions exhibited, by light and electron microscopy, dermal alterations and mineralization of elastic fibres identical to those typical of inherited PXE. None of the relatives and none of the control group showed clinical or structural findings of PXE. The follow-up started in 1988. After 12 years of clinical observation, six patients showed dramatic progression of skin involvement, angioid streaks had progressed in two subjects. One patient had recurrent gastrointestinal bleeding and underwent partial stomach removal for gastric artery aneurysm, one underwent colon resection for intestinal infarct, one patient had a transitory ischaemic attack, one died after an intracranial haemorrhage, two patients died from cardiovascular disease and one from neoplasia. CONCLUSIONS: Thalassaemic patients with PXE-like skin lesions also manifest PXE-like vessel alterations that progress with time. Considering the severe outcome of these lesions, accurate monitoring should be routinely performed on the cardiovascular system of thalassaemic patients with PXE-like skin manifestations.

Adolescent↗
PubMed2000

Hydroxyurea therapy in paraparesis and cauda equina syndrome due to extramedullary haematopoiesis in thalassaemia: improvement of clinical and haematological parameters.

Patients with beta-globin disorders show amelioration of clinical condition by sustained synthesis of fetal haemoglobin in adult life. We report data on a patient with beta(o)-thalassaemia genotype and thalassaemia intermedia clinical phenotype. He received therapy with hydroxyurea (20 mg/kg/d) because of the presence of extramedullary masses causing paraparesis, neurogenic bladder and impotence. During therapy, the patient showed an improved clinical picture and a significant increase in total Hb (from 71.8 to 103.2 g/L) and a gamma/alpha globin synthetic ratio (from 0.39 to 0.68). The myelosuppressive effect of hydroxyurea was revealed by a decrease in CFU-GEMM, BFU-E, and CFU-GM. Therefore hydroxyurea can be effective in the treatment of patients with extramedullary haematopoiesis (EMH) who are not transfusion-dependent and cannot be treated with radiotherapy.

Adult↗
PubMed1998

[Missed compartment syndrome after anterior cruciate ligament-plasty following continuous peridural anesthesia].

In this article we report a case of an early postoperative compartment syndrome of the anterior tibial compartment with complete sensomotoric palsy of the peroneal nerve after arthroscopic-assisted replacement of the anterior cruciate ligament (ACL) of the knee. The tourniquet pressure was 360 mm Hg and operation time was 1.75 h. After the operation the leg was bandaged to avoid swelling of the leg and as antithrombotic prophylaxis. Analgesic therapy was by continuous epidural bupivacaine infusion. Increasing pain of the lower leg was suppressed by additional analgesia. Due to persistent pain despite regular analgesia, the patient was sent to a main hospital on the 3rd postoperative day, where an extremely painful and swollen anterior tibial compartment with intracompartmental pressure of over 100 mm Hg was found. The compartment was released immediately. Despite the appearance of severe muscle damage, no extensive débridement was done. At the second examination, at 48 h, there was minimal perfusion of the muscles without contraction and islands of ischemic necrosis. Clinically, there was complete palsy of the dorsiflexors of the foot. The case shows the danger of a compartment syndrome when tourniquet of the limb, arthroscopy and a firm bandage are combined. Continuous epidural analgesia masks the classic symptoms of compartment syndrome.

Adult↗
PubMed1997

Steroid-eluting electrodes prevent chronic pacing threshold rise in the atrial chamber after oral propafenone administration.

The aim of the study was to evaluate chronic atrial pacing threshold increase after oral propafenone therapy. Fifty patients affected by advanced AV block and sick sinus syndrome were studied at least 6 months after pacemaker implantation, before and after oral propafenone therapy (450-900 mg/day based on body weight). The patients were subdivided into three groups as to the type of electrode implanted, all three unipolar: group I (20 patients) Medtronic CapSure 4003, group II (13 patients) Medtronic Target Tip 4011, group III (17 patients) Medtronic 4057 screw-in leads. In all cases, Medtronic unipolar pacemakers were implanted with the same noninvasive autothreshold measurement method. Propafenone and 5-OH-propafenone blood levels were measured 3-5 hours after drug administration. The packing autothreshold was measured at 0.8, 1.6, and 2.5 V by reducing the pulse width. After propafenone, groups II and III showed a statistically significant threshold rise (P ranging from < 0.01 to 0.05), whereas no significant difference was found in group I. Propafenone and 5-OH-propafenone blood vessels did not show any significant difference among the three groups. Strength-duration curves were drawn for the three groups before and after propafenone: at baseline the curves shifted to the left with the steep part above the knee, clearly favoring CapSure over the other two groups. After propafenone, the curves shifted to the right, with the flat par progressively more evident in groups II and III. In the atrial chamber, steroid-eluting leads prevented threshold increase after propafenone therapy, in contrast with a significant threshold rise with conventional porous and screw-in leads.

Aged↗
PubMed1996

Radiotherapy combined with erythropoietin for the treatment of extramedullary hematopoiesis in an alloimmunized patient with thalassemia intermedia.

We report a patient with thalassemia intermedia who developed a mediastinal syndrome due to the growth of paravertebral hematopoietic masses in the posterior mediastinum. Because the patient did not receive blood transfusions due to alloimmunization, she was first treated with human recombinant erythropoietin (escalating low-moderate doses) to recover hemoglobin levels, then in association with radiotherapy to prevent a worsening of her anemia. The mean Hb level dramatically increased and peaked at week 11, to 83 g/l, and remained unchanged before and after radiotherapy (81 versus 78 g/l). Immediately after radiotherapy extramedullary hematopoiesis volume decreased by 16.4%.

Adult↗
PubMed1996

Continuous low-dose subcutaneous desferrioxamine (DFO) to prevent allergic manifestations in patients with iron overload.

In some patients compliance to subcutaneous desferrioxamine therapy is reduced because of allergic symptoms. Effective drug desensitization consists of bringing patients to tolerate the same mode of administration. We evaluated three thalassemic patients with severe allergies to desferrioxamine. Each patient received weekly three prefilled infusors with desferrioxamine 4 g/48 m1/48 h for s.c. therapy. Follow-up was performed for 12 consecutive weeks. During follow-up no allergic events were noted. The s-ferritin levels decreased from 2583 micrograms/l +/- 485 to 1916 micrograms/l +/- 275 (mean decrease 25.8%, p = 0.038). Compliance to the infusional system was excellent. Our results show that continuous infusion of desferrioxamine using a new infusional delivery system is effective in preventing allergic reactions and in reducing iron overload.

Adult↗
PubMed1996

[The role of syndecan and tenascine during tooth development. Review o the literature].

Morphogenesis and cell differentiation in the developing tooth are controlled by a series of reciprocal interactions between the epithelial and mesenchymal tissues. The exact molecular mechanisms operating in these interactions are unknown at present, but both structural components of the extracellular matrix and cellular receptors have been suggested to be involved. In this review we resume our knowledge about tenascin and syndecan distribution and activity.

Cell Differentiation↗
PubMed1994

Early detection of nephrotoxic effects in thalassemic patients receiving desferrioxamine therapy.

Nineteen transfusion-dependent beta-thalassemia major patients were included in the study. Six of these patients underwent chelation therapy with desferrioxamine by subcutaneous infusion (50 mg/kg/12 hr) and 13 received intravenous infusion (50 mg/kg/6 hr or 100 mg/kg/24 hr). BUN, creatinine, creatinine clearance, beta 2-microglobulin, urinary beta 2-microglobulin and urinary growth hormone excretion were evaluated during desferrioxamine treatment. Thirteen out of nineteen patients presented tubular damage indicated by increased excretion of urinary beta 2-microglobulin. 85% (11 of 13) of these patients showed more serious tubular damage, as demonstrated by concurrent increased urinary growth hormone excretion. Moreover, a positive correlation between urinary growth hormone excretion and urinary beta 2-microglobulin was observed (P < 0.05).

Administration, Cutaneous↗
PubMed1993

Effect of steroid eluting versus conventional electrodes on propafenone induced rise in chronic ventricular pacing threshold.

The aim of this study was to evaluate chronic ventricular pacing threshold increase after oral propafenone therapy. Eighty-three patients affected by advanced atrioventricular block and sick sinus syndrome were studied at least 3 months after pacemaker implantation, before and after oral propafenone therapy (450-900 mg/day based on body weight). The patients were subdivided into three groups according to the type of unipolar electrode that was implanted: group I (41 patients) Medtronic CapSure 4003, group II (30 patients) Medtronic Target Tip 4011, and group III (12 patients) Osypka Vy screw-in lead. In all cases a Medtronic unipolar pacemaker was implanted: 30 Minix, 23 Activitrax, 14 Elite, 12 Legend, and 4 Pasys. Propafenone blood level was measured in 75 patients 3-5 hours after propafenone administration. The pacing autothreshold was measured at 0.8 V, 1.6 V, and 2.5 V by reducing pulse width. At the three different outputs before and after propafenone, threshold increments were significantly lower in group I in comparison with group II and group III (propafenone ranging from < 0.001 to < 0.05). No significant difference was found in pacing impedance or in propafenone plasma concentration in the three groups. Strength-duration curves were drawn for each group at baseline and after propafenone administration. Before propafenone, in group I, the knee was markedly shifted to the left and downward as compared to the classic curve, so that the steep part was predominant; in group II and group III this shift was progressively less evident.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗