Evidence of dissipative solitons in Yb³âº:CaYAlO4.

Operation of an end-pumped Yb³âº:CaYAlO4 laser operating in the positive dispersion regime is experimentally investigated. The laser emitted strongly chirped pulses with extremely steep spectral edges, resembling the characteristics of dissipative solitons observed in fiber lasers. The results show that dissipative soliton emission constitutes another operating regime for mode locked Yb³âº-doped solid state lasers, which can be explored for the generation of stable large energy femtosecond pulses.

Femtosecond and continuous-wave laser performance of a diode-pumped Yb3+:CaYAlO4 laser.

The cw and femtosecond laser operations of Yb(3+):CaYAlO(4) (Yb:CYA) are demonstrated. The laser emitted a maximum cw power of 1.94 W with a slope efficiency (η(slope)) of 71% and an optical-to-optical efficiency (η(opt)) of 51%. Under mode-locking operation, the laser emitted near transform-limited pulses with 156 fs pulse width, 8.1 nJ pulse energy and 0.74 W average power. The η(slope) and η(opt) of the mode-locked laser were 37% and 20%, respectively.

Subpicosecond pulse generation from a Nd:CLNGG disordered crystal laser.

We report on a diode-pumped passively mode-locked subpicosecond Nd:CLNGG disordered crystal laser for the first time to our knowledge. Owing to the large inhomogeneous broadening and spectrum splitting of the disordered crystal, the Nd:CLNGG laser generated 900 fs mode-locked pulses with a repetition rate of approximately 88 MHz at 1061 nm wavelength. With a single-emitter laser diode pumping, a maximum average output power of 486 mW was achieved with a slope efficiency of 26%. Our experimental results show that the four-level Nd:CLNGG disordered crystal could be an excellent alternative for subpicosecond pulse generation.

cDNA cloning, protein structure modeling of rhesus monkey (Macaca mulatta) prothrombin.

OBJECTIVE: Hemorrhagic diseases have been considered to be one of the main causes of xenotransplantation failure. To explore the role of the rhesus monkey (Macaca mulatta) coagulation system in a pig-to-human xenotransplantation model, we primarily studied the full-length cDNA and the three-dimensional (3-D) structures of the important coagulation factor-prothrombin of the rhesus. MATERIALS AND METHODS: The full-length cDNA of rhesus prothrombin was obtained by rhesus monkey liver cDNA library screening and a 5'RACE technique. The 3-D protein structure was modeled using the SWISS-MODEL program. The important macromolecular interaction sites were compared with human and porcine prothrombin. RESULTS: At first, the full-length rhesus prothrombin cDNA was cloned; the sequence was submitted to the Genebank (accession number: EF057490). The full-length cDNA is 2029 bp, with a complete open reading frame of 1884 bp, coding 626 amino acids. The deduced protein sequence contains a signal peptide, propeptide, Gla domain, two Kringle domains, and a Trypsin domain. The nucleotide similarities of rhesus-human and rhesus-porcine genes are 95.64% and 86.14%, and those of the amino acids, 94.51% and 82.82%, respectively. Some important functional sites, such as the catalytic triad DHS, RGD, Na+ -binding, and the carboxylase-binding site, are highly conserved. However, among the three species some variations are observed in potential N-glycosylation, O-glycosylation, phosphorylation, cleavage site, FXa-binding sites. Especially, the autolysis loop shows great differences in both amino acid sequence and 3-D model. CONCLUSIONS: The great similarity of prothrombin among rhesus, human, and porcine confirmed the great value of the pig-to-rhesus xenotransplantation model. The variation especially in some important recognition sites between rhesus and pig would vary the binding affinity of enzymes to xenosubstrates and their reaction velocities in postoperative coagulation processes, which would be one possible reason for the disordered regulation of clotting seen during the xenorejection in animal models.

Immunogenicity and immune modulation of osteogenic differentiated mesenchymal stem cells from Banna minipig inbred line.

Mesenchymal stem cells (MSCs) represent a good choice for cell transplantation due to their multilineage differentiation ability and low immunogenicity. Our previous in vitro studies indicated that undifferentiated swine MSCs show low immunogenicity suppressing the proliferative responses of human peripheral blood lymphocyte to several antigens. In this study, we investigated the immunogenicity and immune modulation ability of osteogenic differentiated MSCs. SLA class I (P1, P14) was detectable by reverse-transcriptase polymerase chain reaction on both differentiated and undifferentiated MSCs. SLA class II (SLA-DRA, SLA-DQA) was only detectable on differentiated MSCs mixed lymphocyte reaction assays demonstrated that both differentiated and undifferentiated MSCs failed to stimulate proliferative responses by human peripheral blood lymphocytes (hPBLs). Furthermore, as undifferentiated MSCs, osteogenic differentiated MSCs also suppressed hPBL proliferation to phytohemaglutinin.

Quantitative analysis of technetium-99m-methylene diphosphonate uptake in unilateral hydroxyapatite-coated total hip prostheses: first year of follow-up.

UNLABELLED: A prospective study was performed on 80 patients who had undergone a unilateral hydroxyapatite (HA)-coated total hip arthroplasty to establish the normal periprosthetic uptake of methylenediphosphonate (MDP) as a function of implant age. METHODS: Patients were imaged periodically while they were asymptomatic at 1, 3, 6 and 12 mo postoperatively. Quantitative measurements were performed with a region of interest (ROI) technique. The HA-coated and uncoated areas were marked in comparison with the normal contralateral femur. The uptake ratios of the MDP were determined postoperatively in the following 12 mo. RESULTS: It was found that a decrease of the uptake ratios occurred in all ROIs. However, for the HA-coated areas, the uptake ratios still remained raised as a result of bony ingrowth. CONCLUSION: The results of the first year of follow-up were considered to be a normal database that will be used as a reference when the same group of patients are followed up to 5 yr postoperatively to detect any potential modes of failure of the implant.

Measurement of anterior-posterior diameter of inferior vena cava by ultrasonography: a new non-invasive method to assess acute changes in vascular filling state.

OBJECTIVE: The aim was to determine whether measurement of the anterior-posterior diameter of the inferior vena cava (IVC) by ultrasonography, before and during deep inspiration, allows indirect information on baseline blood volume and changes in vascular filling state to be obtained in healthy subjects. METHODS: Blood volume was measured in 12 volunteers by a standard radioactive isotope method. The IVC dimensions were measured by ultrasound in various positions. In addition, in 10 male subjects the effect on the IVC dimensions of volume loading was evaluated by rapid infusion of plasma expander. During and immediately following volume loading, the IVC dimensions and blood volume were remeasured. RESULTS: Neither the baseline IVC diameters nor any combination of these variables correlated with the concomitant blood volume. Volume loading increased the anterior-posterior IVC dimensions linearly, the largest increase being observed with the maximum IVC diameter and the subject in supine position. CONCLUSIONS: It follows that ultrasonic IVC indices cannot be used as accurate indirect estimate of baseline blood volume, but provide reliable information on acute changes of the subjects' vascular filling state.

Volume-dependent echocardiographic parameters are not useful for estimating baseline blood volume but are useful for detecting acute changes in vascular filling state.

To assess the hypothesis that echocardiographic variables vary as a function of baseline blood volume and change in response to changes in vascular filling state, we evaluated the relationship between the atrial and ventricular dimensions and left ventricular function, as measured by combined Doppler and M-mode echocardiography on the one hand, and blood volume as measured by a standard radioactive isotope technique on the other. Furthermore, we determined the effect of an increment in vascular filling state induced by plasma volume expansion. Test subjects were ten male and six female volunteers. Blood volume/kg was the only factor not different between male and female subjects and therefore suitable for our study. None of the echocardiographic variables correlated with blood volume/kg. Volume loading increased stroke volume, left atrial diameter, right atrial area, left ventricular end-diastolic dimension, mean velocity of circumferential fiber shortening and left ventricular ejection time. It is concluded that echocardiographic variables are unsuitable for estimating blood volume. Serial measurements of atrial dimensions and left ventricular dimensions are useful for detecting rapid changes in vascular filling state.

Anterior spinal artery syndrome in systemic lupus erythematosus.

We present a patient with systemic lupus erythematosus who developed an anterior spinal artery syndrome (ASAS) in association with livedo reticularis, leg ulcerations and thrombocytopenia. Low serum titres of anticardiolipin antibodies were detectable throughout the course of this disease. The patient recovered from the first episode of ASAS under corticosteroid treatment but remained paralytic after a second episode. Repeated magnetic resonance imaging of the spinal cord failed to show altered signal intensity.