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Photorefractive-damage- (PRD) resistant zirconium-oxide-doped lithium niobate is investigated as a substrate for the realization of annealed proton-exchanged (APE) waveguides. Its advantages are a favorable distribution coefficient, PRD resistance comparable to magnesium-oxide-doped lithium niobate, and a proton-diffusion behavior resembling congruent lithium niobate. A 1D model for APE waveguides was developed based on a previous model for congruently melting lithium niobate. Evidence for a nonlinear index dependence on concentration was found.

We report the case of a 66-year-old woman admitted to the intensive care unit (ICU) for ongoing dyspnea and hemoptoe. She was operated upon in 1979 for aortic coarctation by the interposition of a 14 mm Dacron prosthesis from the left subclavian artery to descending aorta. Clinical evaluation performed over the years was normal with no signs of cardiac failure or prosthesis malfunctioning. The computed tomography scans (CT) showed a progressive increase of the descending aorta diameters and the onset of a pseudo-aneurysm of 50 mm in diameter. Patient was re-operated through a median sternotomy enlarged by a left thoracotomy and intra-operative findings revealed the pseudo-aneurysm originating from a dehiscence of the proximal suture. In order to allow a safe reconstruction of the dilated subclavian artery, a T-shaped composed graft was confectioned and then sutured to the descending aorta and the subclavian artery, respectively. Post-operative course was uneventful and three months CT scan showed a normal position of the composed graft.

The objective of this study was to examine the in vitro effect of a single or a multiple doses of low-level laser irradiation (LLLI) on proliferation of the human osteosarcoma cell line, SAOS-2. SAOS-2 cells were divided in five groups and exposed to LLLI (659 nm diode laser; 11 mW power output): group I as a control (dark), group II exposed to a single laser dose of 1 J/cm2, group III irradiated with a single dose of 3 J/cm2, and group IV and V exposed for three consecutive days to 1 or 3 J/cm², respectively. Cellular proliferation was assessed daily up to 7 days of culturing. The obtained results showed an increase in proliferative capacity of SAOS-2 cells during the first 96 h of culturing time in once-irradiated cells, as compared to control cells. Furthermore, a significantly higher proliferation in the group IV and V was detected if compared to a single dose or to control group after 96 h and 7 days. In conclusion, the effect of the single dose on cell proliferation was transitory and repeated irradiations were necessary to observe a strong enhancement of SAOS-2 growth. As a future perspective, we would like to determine the potential of LLLI as a new approach for promoting bone regeneration onto biomaterials.

In this work we study the photorefractive and electro-optical properties of Zirconium-doped congruent lithium niobate (LN) crystals. In order to set the ground for the utilization of these crystals in nonlinear wavelengthconversion devices, we investigate the dependence of the photorefractive properties of the crystals on dopant concentration and incident power. In our experiments the birefringence variations induced by a 532-nm laser beam are measured by using the Sénarmont method, in the ZrO2concentration range 0-3mol% and intensity range 155- 1800 W/cm2. In order to investigate photorefractivity at high intensities, we have also utilized the direct observation of the distortion of the light spot transmitted by the crystal. In presence of photorefractivity, the transmitted light spot becomes smeared and elongated along the c-axis. Our data show that the threshold ZrO2concentration can be in the range 2.5-3mol%. Considering that the growth of large homogeneous Zr:LN crystals should be easier than for Mg:LN, and that electrical poling of these crystals has already been demonstrated, Zr-doped LN could represent a more convenient choice than Mg:LN for the realization of room-temperature wavelength converters.

Surgical aortic valve replacement (SAVR) is the definitive proven therapy for patients with severe aortic stenosis who have symptoms or decreased left ventricular (LV) function. The development of transcatheter aortic valve implantation (TAVI) offers a viable and “less invasive” option for the treatment of patients with critical aortic stenosis at high risk with conventional approaches. The main objective of this study was the comparison of LV hemodynamic and structural modifications (reverse remodeling) between percutaneous and surgical approaches in the treatment of severe aortic stenosis.

Long-term left ventricular (LV) performance and patient outcome after coronary artery bypass grafting (CABG) procedure in the presence of depressed LV function and hibernating myocardium (HM) have been poorly determined. Therefore, we prospectively evaluated patients undergoing CABG with severe LV dysfunction and HM to elucidate postoperative prognosis.

The 'double-orifice' (DO) technique has been recently proposed as an additional option in mitral valve repair (MVR). However, little is known regarding the long-term postoperative outcome and the predictors of DO results. Therefore, the aim of this study was to evaluate our clinical series and to identify prognostic factors of DO repair.

To see whether degree of pulmonary hypertension or severity of cardiac failure affect the success of pulmonary thromboendarterectomy (PTE) in chronic thromboembolic pulmonary hypertension.

Background. The connection between the donor and the recipient aorta is a potential source of early and late complications as a result of infection, compliance mismatch, and technical and hemodynamic factors. Moreover, the abrupt change in systolic pressure after heart transplantation involves the entire thoracic aorta in the risk of aneurysm formation. The aim of this study was to analyze the types of aortic complications encountered in our heart transplantation series and to discuss etiology, diagnostic approach, and modes of treatment.

To identify whether prophylactic use of ATG is advantageous when compared with ALG in heart‐transplanted patients, a retrospective analysis of clinical and laboratory results was performed. Sixteen patients who received prophylactic rabbit ATG were compared with 36 receiving prophylactic horse ALG. Postoperative monitoring included endomyocardial biopsy, infection surveillance and peripheral lymphocyte identification with a panel of monoclonal antibodies. The ATG‐treated group, when compared with ALG‐treated, showed a marked suppression of peripheral lymphocyte count. Moreover, patients on ATG therapy, when compared with those receiving ALG, showed a statistical and prolonged (up to 30 days) decrease of CD2, CD3, CD4, CD8, CD20, CD25 and T‐5.9 (a CD4 subpopulation) positive cells. The incidence of rejection was lower in the first 3 months in ATG‐treated group and the overall incidence of infection was also significantly decreased. Thus, our results indicate that the use of prophylactic ATG is beneficial in heart‐transplanted patients since it may reduce rejection episodes without increasing the infection rate, despite the greater immunosuppression.

The effects ofL-carnitine on cardiac performance after open heart surgery were evaluated in a balanced, placebo-controlled, double-blind study in 38 patients. Preoperative haemodynamic status was good in all of them. Seventeen subjects underwent mitral valve replacement and 19 patients coronary artery bypass grafting. Five gramsL-carnitine were given intravenously over 2 h, twice daily for 5 consecutive days; moreover, 10 gL-carnitine in 1500 ml cardioplegia were administered through the aortic root after aortic cross-clamping. Surgery was always planned on treatment day 3. The post-ischaemic functional recovery of the heart was assessed by clinical parameters, as well as by biochemical and ultrastructure evaluations on biopsy specimens. No differences were found between the control and the treatment group with respect to all clinical parameters of cardiac performance after cardiopulmonary bypass. At anaesthesia induction, serum carnitine was significantly increased in treated patients, but carnitine concentrations in the right atrial biopsy obtained just before aortic declamping were similar in the two groups. In patients with mitral valve replacement,L-carnitine therapy was associated with significantly higher concentrations of pyruvate, ATP and creatine phosphate in papillary muscle. Glycogen levels were also higher in the treated group, but the difference was not statistically significant. Myocardial ultrastructure on septal biopsies, obtained within 5 min from weaning from extracorporeal circulation, showed better preservation scores for all considered parameters (nucleus, sarcoplasmic reticulum, mitochondria and cellular oedema) in the treated subjects, although the difference reached statistical significance only for nuclei. When biochemical and ultrastructural data are considered, these findings suggest thatL-carnitine improves myocardial metabolism. However, it cannot be concluded thatL-carnitine provides an advantageous support therapy for well-compensated patients requiring cardiac surgery. In contrast, the positive effects ofL-carnitine on cardiac recovery after bypass might become clinically relevant in the surgical setting for haemodynamically compromised patients, in which further investigations are required.

The mechanisms of atrial fibrillation arc multiple reentry circuits spinning around the atrial surface, and these baffle any attempt to direct surgical interruption. The purpose of this article is to report the surgical experience in the treatment of isolated and concomitant atrial fibrillation at the Cardiac Surgical Institute of the University of Pavia.

We report the observation of Gaussian beam fragmentation into Airy-like waveforms during nonlinear propagation. The effect is supported by the high-intensity photovoltaic nonlinearity arising in unbiased pure congruent lithium niobate. The process is found to occur when the nonlinear response is dominated by the nonlocal effects associated with the charge-displacement process.

Transmission of 4×40 4;Gbit/s channels over a 5×100 4;km dispersion-managed link with in-line wavelength conversion of one channel is reported. Polarisation-independent conversion is demonstrated exploiting four-wave mixing in semiconductor optical amplifiers. Error-free operation after conversion and propagation is shown over both G.655 and G.652 fibres.

Sternal osteomyelitis due to Aspergillus fumigatusafter cardiac surgery occurred in two nonimmunosuppressed patients. The clinical features of the infection were markedly different in the two cases. In the first patient, sepsis showed a late and insidious onset followed by slow progression. In the second case, fungi were isolated from wound swabs within a few days of surgery and the clinical picture showed acute onset and rapid progression. Only a few cases of sternal osteomyelitis due to Aspergillus have been described previously after cardiac surgery. Aspergillus infection should be considered in the differential diagnosis of mediastinitis after cardiac surgery, especially in a clinical setting of otherwise unexplained sepsis or nonhealing wound despite apparently adequate treatment.

Cardiopulmonary failure occurred in a 62-year-old patient a few hours after emergency cardiac retransplantation. Venoarterial extracorporeal membrane oxygenation was required to support biventricular dysfunction; thereafter, inhaled nitric oxide was given for residual hypoxemia and pulmonary hypertension. We report survival after venoarterial extracorporeal membrane oxygenation and inhaled nitric oxide treatment for both heart and lung failure in a heart recipient.