In a double-blind, randomised study of thromboprophylaxis in patients undergoing total hip replacement, we compared a low-molecular-weight heparin with a placebo. Of the 120 patients enrolled, 112 ...completed the trial; 58 in the treatment group and 54 in the placebo group. Nine (16%) patients in the treatment group and 19 (35%) in the placebo group developed deep venous thrombosis, diagnosed by the 125I-fibrinogen uptake test (p < 0.02). Verification was obtained by phlebography in 86% of the patients. Prolonged surgery increased the risk of thrombosis in the placebo group but not in the treatment group (p < 0.05). There were significantly more cases of deep venous thrombosis in the placebo group during the first four postoperative days (p < 0.02). The groups did not differ with respect to peroperative and postoperative bleeding. Low-molecular-weight heparin offers safe and easily administered thromboprophylaxis in total hip replacement.
We demonstrate, for the first time, a highly nonlinear polarization maintaining photonic crystal fiber with zero dispersion at 1.55 /spl mu/m, nonlinear coefficient of 20 (Wkm)/sup -1/ and splice ...loss to standard technology fiber of 0.3 dB.
The high incidence of thromboembolic complications in orthopedic surgery necessitates an effective thromboprophylactic regime. Current methods of prophylaxis are discussed, and principles of ...thromboprophylaxis with low-molecular weight heparin are presented.
For development of hollow-core transmission fibers the realizable fibers lengths, bandwidth, characterization and compatibility with standard technology are important issues. We report record-length ...air-guiding fiber, spectral properties, splicing, and OTDR measurements.
A prospective, randomized, double-blind trial concerning prophylaxis of thrombosis in 82 patients undergoing hip fracture surgery was conducted to compare a new low-molecular-weight heparin (Fragmin) ...with a placebo. Deep venous thrombosis (DVT) was detected by I125-fibrinogen uptake test followed by ascending phlebography when positive. Sixty-eight patients completed the study and a 50% reduction in the incidence of DVT was demonstrated: 9/30 (30%) patients in the treatment group and 22/38 (50DVT. This significant difference was achieved by one daily dose of 5.000 IU Fragmin subcutaneously, commencing preoperatively and continuing for six days. No differences in bleeding nor other complications in the two groups were observed. Fragmin administered once daily offers an effective and safe prophylaxis of thrombosis in hip fracture surgery.
The analogy between photonic crystal fibres and step index fibres Birkst, T.A.; Mogilevtsev, D.; Knight, J.C. ...
OFC/IOOC . Technical Digest. Optical Fiber Communication Conference, 1999, and the International Conference on Integrated Optics and Optical Fiber Communication,
1999, Letnik:
4
Conference Proceeding
Some properties of photonic crystal fibers quantitatively match those of standard step-index fibers, provided the right analogy is made between them, this is illustrated by calculations of ...second-mode cutoff (reported here for the first time to our knowledge) and propagation constants.
In this paper, we present the results of a high power photonic crystal fiber laser, where the well-known concepts of double-clad and large-mode-area design are transfered to an actively doped ...microstructured fiber. The double-clad design is achieved by surrounding the inner cladding (pump core) with a web of silica bridges (as thin as 390 nm and approximately 50 /spl mu/m long) which are substantially narrower than the wavelength of the guided radiation. It is concluded that air-clad microstructure ytterbium-doped large-mode-area fibers should be scalable to kW-level output powers, where nonlinearity will limit the performance.
Polarization properties of photonic crystal fibers Petersson, A.; Broeng, J.; Hansen, K.P. ...
2006 Optical Fiber Communication Conference and the National Fiber Optic Engineers Conference,
2006
Conference Proceeding
Photonic crystal fibers provide increased range of mode-field diameters for passive and active fibers. At present, single mode photonic crystal fibers with mode field diameters ranging from ...sub-micron to beyond 40 /spl mu/m have been demonstrated. For a number of applications, it is desirable to introduce polarization maintaining properties of such fibers. In this presentation, we report on the latest development within this area and explain the design and characteristics of different types of photonic crystal fibers with both polarization-maintaining and polarizing properties.
Opt. Express 12, 3500 (2004). We demonstrate a new class of hollow-core Bragg fibers that are composed of
concentric cylindrical silica rings separated by nanoscale support bridges. We
theoretically ...predict and experimentally observe hollow-core confinement over
an octave frequency range. The bandwidth of bandgap guiding in this new class
of Bragg fibers exceeds that of other hollow-core fibers reported in the
literature. With only three rings of silica cladding layers, these Bragg fibers
achieve propagation loss of the order of 1 dB/m.
