Influence of protective isolation on outcome of allogeneic bone marrow transplantation for leukemia

Most of the previously published surgical series of suprasellar meningiomas have two disadvantages: (1) patients involved were treated within a relatively long time period, making analysis more difficult, (2) radiographic long term follow-up examinations with either CT- or MRI-scans were not performed. Both disadvantages were overcome in our retrospective clinical study, consisting of 50 consecutive patients with suprasellar meningiomas treated between 1982 and 1991. Radiological, ophthalmological, and neurological investigations were performed preoperatively, postoperatively and at long term follow-up (mean: 5.7 years). A radiologically confirmed radical tumour removal could be achieved in 84% of patients. Both, the peri-operative mortality (2%) and serious operative morbidity (6%) were low. However, 12% of patients developed late onset epilepsy. At long term follow-up, visual function was improved in 67%, unchanged in 9% and worsened in 24%. In more than 50% of patients the vision showed recovery over a longer time period than the first 10 days after operation. Radiographic control examinations revealed tumour recurrences in 2 patients (both asymptomatic) and progress of residual tumour in 5 patients (2 symptomatic, 3 asymptomatic). Since introduction of modern neurosurgery, a clear improvement in the surgical treatment of suprasellar meningiomas can be observed. However, the still long delay in diagnosing these tumours correctly prevents a further improvement of the ophthalmological results at long-term follow-up. Due to a relatively high rate of late onset epilepsy, anticonvulsive prophylaxis for 6 months seems to be justified. Regarding present preoperative diagnostic measures, ia-DSA seems only be indicated in patients with CT/MRI-scans, suspicious for tumourous narrowing or invasion of major cerebral arteries. In addition, we recommend radiographic control examinations at regular time intervals to confirm radical tumour removal and to detect the "ideal" point of time for renewed treatment.     

STUDY OF FACTORS INVOLVED IN GLAZE-SLIP CONTROL,I–IV* I,GLAZE-SLIP SPECIFICATIONS

Experiments were conducted to find a simple, adequate means of specifying glaze consistency. Tests showed that the amount of slip clinging to a glass plate after it is withdrawn from a reservoir of slip (known as its coherence value) was directly influenced by such factors as amount of water, clay content, and age. These factors are commonly thought of as governing the working quality of the slip. Surface tension has little apparent relation to the working qualities of the slip. Examination of the fired glazes revealed that a distinct coherence value separated good glazes from poor types. A total of 110 pieces was fired; of these samples, fifty-two were glazed with slips having coherence values above 0.04 gm. per sq. cm. Only three of the fifty-two samples were satisfactory; the remaining fifty-eight were coated with slips with a coherence value of less than 0.04 gm. per sq. cm. Only nine of these were defective in any respect and most of them were in the region of 0.04 gm. per sq. cm. coherence value.     

The composition and metabolism of high density lipoprotein subfractions

The composition and metabolism of high density lipoprotein (HDL) subfractions were investigated in seven nomal individuals. Mean HDL₂ (d, 1.063–1.125 g/ml) composition (by weight) was 43% protein, 28% phospholipid, 23% cholesterol, and 6% triglyceride, and mean HDL₃ (d, 1.125–1.21 g/ml) composition was 58% protein, 22% phospholipid, 14% cholesterol, and 5% triglyceride. The mean apoA-I; apoA-II weight ratio was 4.75 for HDL₂ and 3.65 for HDL₃.HDL₂ protein was proportionally slightly richer in C apolipoproteins and higher molecular weight constituents (including apoE) than HDL₃. Kinetic studies utilizing radiolabeled HDL_A (d, 1.09–1.21 g/ml), HDL₂, and HDL₃ demonstrated rapid exchange of apoA-I and apoA-II radioactivity among HDL subfractions, similar fractional rates of catabolism of apoA-I and apoA-II within HDL, and similar radioactivity decay within HDL subfractions. Mean plasma residence time was 5.74 days for radiolabeled HDL₂ and 5.70 days for radiolabeled HDL₃. Differences in HDL protein mass among individuals were largely due to alterations in catabolism, and in general both HDL₂ and HDL₃ were catabolized via a plasma and a nonplasma pathway. Data from simultaneous radiolabeled very low density lipoprotein and HDL studies in 2 individuals are consistent with the concept that apoC-II and apoC-III are catabolized at a different rate than are apoA-I and apoA-II within the HDL density range.     

Evaluation of the friction of WC/DLC solid lubricating films in vacuum

The accuracy of nanopositioning is to a large extent limited by the friction-caused errors, particularly in vacuum environments. An investigation of the friction behaviour of sp²-bonds dominating diamond like carbon (DLC) coatings and WC_1−x/DLC, WC(N)/DLC multilayer coatings, which are considered to be used in nanopositioning in vacuum, have been performed by a vacuum microtribometer. By using an atomically smooth Si sphere as a counterface, the reciprocating sliding friction was measured at a normal load <5 mN, and running speed at a 1–100 μm/s in ambient air and in ultra high vacuum (UHV) at 10⁻⁷ Pa, and correlated with microstructures and properties of the coatings. When tested in UHV, the coefficient of friction (COF) for pure DLC coatings (thickness: 700 nm) changes significantly between 0.2 and 0.4. Once the thickness of DLC layers is limited to 5 nm by formation of multilayer coatings, the COF in UHV decreases by nearly one order to 0.02–0.05. We suggest that the deformation of DLC films and the transfer films determines COF. Thick DLC coatings can induce more plastic deformation and consumes more energy in sliding resulting in a high COF. Thickening of the transfer film in running leads to a continuous decrease of COF since the deformation of the transfer films turns easier. The low COF of multilayer coatings is mainly due to their confinement of the thickness of DLC films. A consistent velocity-strengthening frictional behaviour of both WC_1−x/DLC and WC(N)/DLC coatings in UHV indicates that the transfer films acting as a thin layer of granular material. Further study of the friction behaviour with the presence of such granular materials might be interesting for the further development of tribological coatings for vacuum applications.     

Selective precision synthesis of planar mechanisms satisfying position and velocity constraintsSelective präzisions-sythese ebener getriebe für gegebene stellungen und geschwindigkeiten

For many path generating mechanisms used in today's machines, the tracer point velocity may be as critical as its generated position for adequate mechanism performance [1,2]. In this paper the recently developed Selective Precision Synthesis technique has been extended to include the synthesis of mechanisms whose tracer points satisfy velocity as well as position specifications. The mechanism designer now has the capability of determining the planar mechanisms whose tracer points generate the positions and velocities within specified limits of accuracy. The method is applicable to all planar mechanisms constructed from dyads—including 4-bar, slider-crank, multi-loop and multi-link mechanisms. The theory is programmed for digital computation and numerical examples are presented to illustrate the use of the method.     

Differential Effects of Estrogen and Progestin on Apolipoprotein B100 and B48 Kinetics in Postmenopausal Women

The distinct effects of the estrogen and progestin components of hormonal therapy on the metabolism of apolipoprotein (apo) B‐containing lipoproteins have not been studied. We enrolled eight healthy postmenopausal women in a placebo‐controlled, randomized, double‐blind crossover study. Each subject received placebo, conjugated equine estrogen (CEE, 0.625 mg/day) and CEE plus medroxyprogesterone acetate (MPA, 2.5 mg/day) for 8 weeks in a randomized order, with a 4‐week washout between phases. Main outcomes were the fractional catabolic rate (FCR) and production rate (PR) of apo B100 in triglyceride‐rich lipoproteins (TRL), intermediate‐density lipoproteins (IDL) and low ‐density lipoprotein (LDL) and of apo B48 in TRL. Compared to placebo, CEE increased TRL apo B100 PR (p = 0.04). CEE also increased LDL apo B100 FCR (p = 0.02), but this effect was offset by a significant increase in LDL apo B100 PR (p = 0.04). Adding MPA to CEE negated the CEE effects resulting in no significant changes in TRL apo B100 PR and LDL apo B100 FCR and PR relative to placebo. Relative to placebo, during CEE there was a trend toward a reduction in plasma apo B48 concentrations and PR (p = 0.07 and p = 0.12, respectively). Compared with CEE, CEE + MPA significantly increased TRL apo B48 FCR (p = 0.02) as well as apo B48 PR (p = 0.01), resulting in no significant changes in apo B48 concentration. Estrogen and progestin have independent and opposing effects on the metabolism of the atherogenic apo B100‐ and apo B48‐containing lipoproteins.     

Sealability Properties of Fluorine-Free Fire-Fighting Foams (FfreeF)

This contribution compares the sealability performance of recently developed three synthetic foam formulations (that do not contain fluorosurfactants or fluoropolymers) with that of an aqueous film forming foam (AFFF). We apply the sealability methodology outlined in the Australian Defence Force Specification, DEF(AUST)5706. This methodology specifies a 0.28 m² small-scale indoor fire pan. The pan is first filled with 10 L of water and then 5 L of AVGAS (aviation gasoline, flash point of −50°C) or heptane (flash point of −4°C) is placed on top of the water. Foams were generated from a pressurised extinguisher with a foam nozzle as described in the standard’s specification, set to create foams with expansion of 4:1. The foam spread across the fuel until the entire fuel surface was covered with foam. At 5 min intervals, a lit taper was introduced into the space above the pan area by passing it twice around the surface of the foam in a circular motion at a height of approximately 15 mm from the surface of the foam. The results demonstrate differences in the sealability performance between AFFF and fluorine-free foams (FfreeF). Under laboratory conditions, with a foam blanket 1–2 cm deep, best-performing FfreeF formulation (RF6) provides about 30% of the durability of an AFFF for protection against evaporation of low-flashpoint flammable liquids. We also note in the results the significant differences among FfreeF with almost no sealability of AVGAS vapours offered by the two other formulations. Presented at the Suppression and Detection Research and Applications—A Technical Working Conference (SUPDET 2007); Wyndham Orlando Resort, March 5–8, 2007, Orlando, FL, USA.     

Volumetric hemodynamic parameters to guide fluid removal on hemodialysis in the intensive care unit

Estimation of removable excess body fluid is difficult in critically ill patients with renal failure. Volumetric hemodynamic parameters are increasingly being used to guide fluid therapy in the intensive care unit, but their suitability to monitor fluid removal with hemodialysis in critically ill patients is not known. Changes in the extravascular lung water index (EVLWI) and intrathoracic blood volume index (ITBVI) measured with transpulmonary thermodilution immediately before and after hemodialysis were analyzed from 39 hemodialysis sessions of 9 patients consecutively treated in the medical intensive care unit of a German University Hospital. Additional hemodynamic, ventilation, and oxygenation-related parameters were recorded at the same time. Online relative blood volume (RBV) monitoring was performed in 29 sessions. Comparisons of pre and postdialysis values showed a significant reduction of the EVLWI with fluid removal (p=0.009), with only a slight nonsignificant decrease in the ITBVI. The cardiac index (CI) also decreased significantly (p=0.010), whereas blood pressure remained stable. Oxygenation improved significantly (p=0.005), and the hematocrit increased significantly with dialysis (p=0.039). There was no correlation between hematocrit changes and RBV measurements. Significant correlations existed between ITBVI and CI changes (p<0.001), but not to EVLWI reduction. The removal of excess body fluid on hemodialysis is reflected by the EVLWI reduction, whereas the preservation of cardiac preload is shown by ITBVI stability. Volumetric hemodynamic parameters could be useful to guide fluid removal with hemodialysis in the intensive care unit.     

Adhesion Maps Using Scanning Force Microscopy Techniques

A technique has been developed that allows a real-time measurement of the lift-off force required to remove a scanning force microscope tip from a substrate. Both topography and adhesion maps are obtained simultaneously, allowing the correlation between topography and adhesion properties to be studied. Quantitative values of important adhesion parameters can be extracted from these data. A number of examples are given which illustrate the utility of this technique.     

The effect of water on friction of MEMS

Water plays a significant role in the performance of micro electro mechanical systems (MEMS). A special apparatus was employed to investigate the adhesive friction attributed to water at low coverages, i.e., in the nanometer range, where friction and adhesion are a function of the water layer thickness. In addition, the history of the sample surface also plays a significant role. The friction forces associated with hydrophobic samples are negligibly affected by humidity changes, whereas those of hydrophilic samples show a strong dependence. Sample coverage and the friction force are also influenced by the sample temperature. High forces were measured for high humidities at low sample temperatures, for hydrophilic silicon. In contrast, hydrophobic samples show an increase of the friction force with increasing temperature. Experiments performed under high vacuum demonstrated that decreasing the water layer thickness by desorption decreases the friction force with several sub‐minima and sub‐maxima. The friction signal is accompanied by sudden fluctuations. For submonolayer coverage the friction force starts to increase. This revised version was published online in July 2006 with corrections to the Cover Date.