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At least 127 records · Page 7Linked to original sources
PubMed1992

[Postoperative astigmatism. 3.5 mm scleral tunnel incision and implantation of a HEMA posterior chamber lens vs 7 mm scleral step incision and implantation of a PMMA posterior chamber lens].

In a prospective study, two groups of 35 patients each were compared following phacoemulsification and posterior lens implantation. Both groups were followed up to evaluate the evolution of the postoperative astigmatism during a minimum of 6 months. In group A, a HEMA posterior chamber lens was implanted through a 3.5 mm scleral tunnel incision. In group B, a PMMA posterior chamber lens was implanted through a 7 mm scleral step incision. The data were analyzed for the whole observation time with reference to preoperative, early postoperative, absolute and induced astigmatism. Different subgroups were formed. Vector analysis was performed in both groups in order to determine surgically induced axial changes, e.g., the intensity and direction of the power working on the cornea. The results were compared. Group A showed lesser early postoperative astigmatism than group B; however, group A also returned to the preoperative values more quickly. Both groups exhibited a shift towards against-the-rule astigmatism.

Astigmatism↗
PubMed1990

Comparative study of serum insulin, glucose, growth hormone and cortisol of students at 794.7 mm Hg (Dead Sea level) and 697.5 mm Hg (Amman) barometric pressures.

Serum insulin, glucose, growth hormone and cortisol levels were measured in high school students living at Dead Sea level (390 m below sea level) and Amman (766 m above sea level) with 794.7 mm Hg and 697.5 mm Hg barometric pressures, respectively. A total of 54 and 50 healthy male subjects of age 17-19 years, having almost identical economic and nutritional status were studied. We found that serum insulin and growth hormone levels were significantly higher; whereas serum glucose and cortisol levels were significantly lower (p less than 0.05) for subjects at Dead Sea level than those at Amman.

Adolescent↗
PubMed1985

The stabilising function of the mm. iliocostales and the mm. multifidi during walking.

The myoelectric activity of the mm. multifidi and the mm. iliocostales lumborum of six subjects was recorded during walking. The subjects walked on a treadmill as well as on a fixed walkway. On the treadmill, recordings were made at two different speeds and with a varying loading of the spine. There was almost no difference in myoelectric activity time between the treadmill and the fixed walkway. Related to unloaded walking, both the multifidi and the iliocostales showed an increase in activity time when the subjects carried a load of 5 kg in front of the trunk and a decrease of activity time with a load of 5 kg on the back. A load on the lateral aspect of the body shortened the muscle activity time of the multifidi on the homolateral side. In three subjects the same pattern was found for the iliocostales, but in the other three subjects there was no activity registered at all. On the side contralateral to the load, the multifidi showed no increase of activity time while the iliocostales muscles demonstrated an increase. It is concluded that during walking the iliocostalis muscle has a more important function in lateral bending than the multifidus. It was remarkable that the multifidi muscles of the left side were active for longer periods than were those of the right side in all situations except during lateral loading.

Adult↗
PubMed1995

[Incidence of ultrasound detectable liver hematomas after ultrasound controlled fine needle puncture with the 0.95 mm cutting biopsy cannula in comparison with percutaneous liver biopsy with the 1.4 mm Menghini needle].

BACKGROUND: Recently, a high incidence of ultrasound-detected hepatic hematomas due to percutaneous liver biopsy has been reported. Until yet, little is known about the incidence of asymptomatic hepatic hematomas following sonographically guided fine-needle biopsy. PATIENTS AND METHODS: For that reason, we carried out a prospective study with sonographic examinations before and after liver biopsy in 160 patients. 51 patients, aged 50 to 83, median 67 years, with focal liver lesions had ultrasound-guided liver biopsy using the 0.95 mm-cut biopsy-needle, in 109 patients (17 to 80, median 49 years) with diffuse liver disease percutaneous liver biopsy with the 1.4 mm-needle of Menghini was performed. RESULT: After fine-needle biopsy none of the 51 patients with focal liver lesions displayed liver hematoma on ultrasonography. In the group of patients who underwent percutaneous Menghini biopsy a liver hematoma, sized up to 12 x 5 cm in diameter, occurred four times (3.7%). CONCLUSION: The results of this study indicate that fine-needle biopsy of the liver is a particularly safe diagnostic procedure, when compared with percutaneous Menghini biopsy.

Adolescent↗
PubMed1994

Construction of a 28-mm 1H/13C probe and actively shielded Z-gradient set for operation in a 9.4 T/89 mm magnet.

In this work, we present a new RF and gradient assembly for operation in a 9.4 Tesla/89 mm magnet. This assembly was designed in order to enable 1H-NMR perfusion studies that are based on proton-observed carbon-edited approaches or gradient selected double quantum coherence. The RF portion of this probe assembly is comprised of a modified Alderman-Grant coil and a saddle coil operating at 400 and 100 MHz, respectively. These coils are surrounded by an actively shielded Z gradient, which also allows for the use of gradient-based water suppression without the need for carbon selection. We demonstrate that this probe can be used to implement gradient selected double quantum coherence experiments resulting in a high degree of water suppression.

Carbon Isotopes↗
PubMed2006

Long-term results of the cementless ALLOCLASSIC hip arthroplasty system using a 28-mm ceramic head: with a retrospective comparison to a 32-mm head.

One hundred twenty-four total hip arthroplasties in 119 patients, all performed with the cementless ALLOCLASSIC hip arthroplasty system (SL stem and CSF cup; Centerpulse, Winterthur, Switzerland), were analyzed retrospectively. In all hips, a 28-mm head and an ultrahigh-molecular-weight polyethylene inlay were used. Of the 124 hips, 81 could be investigated clinically and radiologically after an average of 150.6 months (range, 133-169 months). Twenty-six patients (26 hips) died in the interim. One of these patients had septic cup loosening. Seventeen hips (16 patients) were not available for follow-up because of health reasons (12 hips in 11 patients), lack of cooperation (3 hips in 3 patients), or loss to follow-up (2 hips in 2 patients). Of the 124 total hip arthroplasties, 4 cups were removed (2 aseptic and 2 septic loosening). No stem had to be removed. If aseptic loosening is defined as the end point, the survival rate is 98.4% (95% confidence interval, 93.8%-99.6%) for the cup and 100% for the stem after 157 months. If revision for any reason is defined as the end point, the survival rate is 95.6% (95% confidence interval, 90.1%-98.3%). Before operation, the average Harris Hip Score was 36.4 points (21-46). At time of follow-up, the average Harris Hip Score was 89.7 points (54-100). Radiolucent lines and osteolyses were found only seldom (mostly in the proximal stem zones).

Adult↗
PubMed2004

Thienyl carboxylate ligands bound to and bridging MM quadruple bonds, M = Mo or W: models for polythiophenes incorporating MM quadruple bonds.

A series of compounds of the form [M(2)L(4)] and [[((t)()BuCO(2))(3)M(2)](2)(mu-L')] have been made where M = Mo or W, L = a thienyl, bithienyl, or terthienyl carboxylate, and L' = a corresponding thienyl dicarboxylate. The electronic absorption spectra are reported and the electronic structures discussed. Intense metal-to-ligand charge transfer bands traverse the visible and near-IR regions of the electronic absorption spectrum. The compounds show reversible metal-based oxidations and quasireversible ligand-based reductions. The molecular structure of Mo(2)(O(2)C-2-Th)(4).2THF is reported, on the basis of a single crystal X-ray diffraction study. These compounds provide insight into the expected properties of related dimetalated polythiophenes incorporating MM quadruple bonds.

Carboxylic Acids↗
PubMed1992

Modified SRK formula for axial myopia (24.5 mm < or = axial length < 27.0 mm).

When used for eyes with greater than average axial length (AXL), the SRK formula has been reported to have a tendency to yield more myopic refractions than those predicted. To further evaluate such findings, we studied 609 eyes with AXLs between 24.5 and 27.0 mm. Comparing the predicted with the actual refractions and calculating the range of errors, we found that the postoperative refractions were more myopic than predicted. Then, based on our evaluation of the relationship between the postoperative refractions and the powers of the implanted intraocular lenses (IOLs), we devised the following formula: R = 0.8 x (P - I) + 0.57 (P < .01) in which R = the postoperative refraction; P = the emmetropic IOL power; and I = the actual IOL power. Testing this modified SRK formula in 55 additional eyes, we found that the predicted postoperative refractions it yielded were more accurate than those calculated using five earlier formulas.

Cataract Extraction↗
PubMed1994

Percutaneous native renal biopsy: comparison of a 1.2-mm spring-driven system with a traditional 2-mm hand-driven system.

Over the last few years spring-driven mechanical biopsy guns have been introduced for performing renal biopsies. There has been little research done comparing these guns with traditional hand-driven needles in performing biopsies of native kidneys. We wished to compare our experience with the two needle types. We studied retrospectively the results and complication rates of 155 native kidney biopsies. Sixty-nine were performed with hand-driven 14-gauge needles and eighty-six with 18-gauge, spring-driven biopsy guns. Sufficient tissue for diagnosis was obtained in 96% of cases in the hand-driven group compared with 99% in the biopsy gun group (P = NS). Complications occurred in six cases in the hand-driven group compared with one case in the biopsy gun group (P = 0.02). As expected, the reported number of glomeruli per core in the 14-gauge cores was greater than in the 18-gauge cores (16.5 v 6.2, P < 0.01). This was partially offset by the greater number of passes made with the smaller needle. We conclude that similar results can be expected from both biopsy methods, with a possible slight decrease in complications using biopsy guns with smaller needle diameters.

Adolescent↗
PubMed2004

Hydration energies in the gas phase of select (MX)mM+ ions, where M+ = Na+, K+, Rb+, Cs+, NH4+ and X- = F-, Cl-, Br-, I-, NO2-, NO3-. Observed magic numbers of (MX)mM+ ions and their possible significance.

The sequential hydration energies and entropies with up to four water molecules were obtained for MXM(+) = NaFNa(+), NaClNa(+), NaBrNa(+), NaINa(+), NaNO(2)Na(+), NaNO(3)Na(+), KFK(+), KBrK(+), KIK(+), RbIRb(+), CsICs(+), NH(4)BrNH(4)(+), and NH(4)INH(4)(+) from the hydration equilibria in the gas phase with a reaction chamber attached to a mass spectrometer. The MXM(+) ions as well as (MX)(m)M(+) and higher charged ions such as (MX)(m)M(2)(2+) were obtained with electrospray. The observed trends of the hydration energies of MXM(+) with changing positive ion M(+) or the negative ion X(-) could be rationalized on the basis of simple electrostatics. The most important contribution to the (MXM-OH(2))(+) bond is the interaction of the permanent and induced dipole of water with the positive charge of the nearest-neighbor M(+) ion. The repulsion due to the water dipole and the more distant X(-) has a much smaller effect. Therefore, the bonding in (MXM-OH(2))(+) for constant M and different X ions changes very little. Similarly, for constant X and different M, the bonding follows the hydration energy trends observed for the naked M(+) ions. The sequential hydration bond energies for MXM(H(2)O)(n)(+) decrease with n in pairs, where for n = 1 and n = 2 the values are almost equal, followed by a drop in the values for n = 3 and n = 4, that again are almost equal. The hydration energies of (MX)(m)M(+) decrease with m. The mass spectra with NaCl, obtained with electrospray and observed in the absence of water vapor, show peaks of unusually high intensities (magic numbers) at m = 4, 13, and 22. Experiments with variable electrical potentials in the mass spectrometer interface showed that some but not all of the ion intensity differentiation leading to magic numbers is due to collision-induced decomposition of higher mass M(MX)(m)(+) and M(2)(MX)(m)(2+) ions in the interface. However, considerable magic character is retained in the absence of excitation. This result indicates that the magic ions are present also in the saturated solution of the droplets produced by electrospray and are thus representative of particularly stable nanocrystals in the saturated solution. Hydration equilibrium determinations in the gas phase demonstrated weaker hydration of the magic ion (NaCl)(4)Na(+).

Journal Article↗
PubMed2003

Electric poling and electromechanical characterization of 0.1-mm-thick sensor films and 0.2-mm-thick cable layers from piezoelectric poly(vinylidene fluoride-trifluoroethylene).

Piezoelectric polymers have been proposed for many sensor and actuator applications. Among these, piezoelectric polymer films with thicknesses between several tens and a few hundreds of micrometers as well as coaxial cables with piezoelectric polymer layers are highly suitable and attractive for the detection of mechanical loads. In addition to good piezoelectric properties, materials for such sensors should have high mechanical strength. Therefore, the most common materials are nonporous piezoelectric polymers, such as polyvinylidene fluoride (PVDF) or its copolymer with trifluoroethylene (P(VDF-TrFE)). Here, P(VDF-TrFE) polymer films as well as the operating principle and the geometry of piezoelectric polymer cables are described. As active piezoelectric cable layer, P(VDF-TrFE) (76/24) was employed. After electrical poling with one or more point-to-cable corona discharges, the polarization in the P(VDF-TrFE) layer was investigated. Poling parameters, such as electric field and poling time, were varied. The resulting polarization was characterized with measurements of polarization profiles across the film or the cable-layer thickness as well as with the determination of other electromechanical quantities. The optimized poling process yields good piezoelectric properties in the piezoelectric polymer layers as well as useful sensor properties of the piezoelectric polymer cable, which are assessed and discussed.

Journal Article↗