Origins of nanoscale heterogeneity in ultrathin films

A key challenge in thin-film growth is controlling structure and composition at the atomic scale. We have used spatially resolved electron scattering to measure how the three-dimensional composition profile of an alloy film evolves with time at the nanometer length scale. We show that heterogeneity during the growth of Pd on Cu(001) arises naturally from a generic step-overgrowth mechanism relevant in many growth systems.

Enhanced self-diffusion on Cu(111) by trace amounts of s: chemical-reaction-limited kinetics

We find that less than 0.01 monolayer of S can enhance surface self-diffusion on Cu(111) by several orders of magnitude. The measured dependence of two-dimensional island decay rates on S coverage (theta(S)) is consistent with the proposal that Cu3S3 clusters are responsible for the enhancement. Unexpectedly, the decay and ripening are diffusion limited with very low and very high theta(S) but not for intermediate theta(S). To explain this result we propose that surface mass transport in the intermediate region is limited by the rate of reaction to form Cu3S3 clusters on the terraces.

[Follow-up of symptoms, parameters of respiratory function, and data on specific sensitization in a group of subjects with latex-induced asthma and rhinitis]

We re-investigated 13 workers 6 years (SD 2) after the first diagnosis of asthma or rhinitis caused by latex, to update the exposure to latex, the eventual symptoms, respiratory function (spirometry and metacholine PD20 FEV1), skin prick test to common allergens and latex, RAST to latex, total IgE levels and eosinophils count in the blood. At the follow up, all the workers stopped wearing powdered latex gloves, but for 10 an indirect exposure to latex was still possible. All cases referred improvement of respiratory symptoms at work, but 7 workers occasionally complained of mild symptoms. No statistically significant variations of respiratory function test and of the immunological parameters were found. The workers with persistent respiratory symptoms at work had a longer duration of symptoms before the diagnosis (p = 0.02), if compared with workers without symptoms.

[Ultrasound-guided laparoscopic ischemia of uterine leiomyomas]

OBJECTIVE

Implementation of minimally invasive selective ischemization of uterine leiomyomas at fertile age women.

DESIGN

Pilot study.

SETTINGS

Gynecological institute GynCentrum, Prague.

SUBJECT AND METHODS

Ultrasound guided laparoscopic electro-coagulation of myoma's vascular stalk was carried out at consecutive 48 women during June 2000-June 2002.

RESULTS

Significant reduction of the original size of the leiomyoma was achieved at 98% of women during 3 months after the surgery. No surgery complications were observed as well as any obstetrical complications at five patients getting pregnant after the procedure.

CONCLUSION

In addition to good therapeutic effect this minimally invasive technique brings more rapid recovery, smaller visible incisions and reduced complication, particularly during consequent pregnancy.

Direct observation of misfit dislocation glide on surfaces

Using scanning tunneling microscopy we have observed thermally induced dislocation glide in monolayer Cu films on Ru(0001) at room temperature. The motion is governed by a Peierls barrier that depends on the detailed structure of the dislocations, in particular upon whether the threading dislocations that terminate them are dissociated or not. Calculations based on the Frenkel-Kontorova model reproduce the threading dislocation structure and provide estimates of the Peierls barrier and dislocation stiffness which are consistent with experiment.

Why do cohabiting couples marry? An example of a causal event history approach to interdependent systems

The purpose of this paper is to demonstrate a causal approach to interdependent systems based on two empirical investigations. These examples demonstrate 1) the study of two highly interdependent processes: entry into first marriage as the dependent process and the process of first birth/first pregnancy as the explaining one; 2) an interdependence occurring mainly in a very specific phase of individuals' lives (i.e., during the period of first family formation); 3) the involvement of time lags between cause and its effect (e.g., time until detection of conception); and 4) the highly dynamic character of an unfolding effect over time (i.e., the effect of first pregnancy/first birth on first marriage strongly depends on the progress of pregnancy and the time since the birth has taken place).

[Vulvar involvement as a rare extra-intestinal manifestation of Crohn disease]

BACKGROUND

Crohn's disease may involve all parts of the gastrointestinal tract. Extraintestinal manifestations with and without continuity to the intestine are described. The most common complications are the involvement of bone (articulations), liver and eyes. Crohn's disease of the vulva is rare and only a few cases have been reported in the literature.

CASE REPORT

The 45-year-old woman has a 15-year history of a marked chronic-inflammatory bowel disease. The diagnosis of Crohn's disease was never confirmed histologically. In 1984, she developed a painful vulvar swelling and erythema. A fungal infection was suspected and she was treated with topical antimycotic medication, but there wasn't any improvement. In July 1995, biopsies of the vulva showed a granulomatous inflammation consistent with Crohn's disease. Oral metronidazol therapy (20 mg/kg/day) was started. After 2 months, the erythema had healed completely but the vulvar swelling remained.

CONCLUSIONS

The treatment of this extraintestinal manifestation is very difficult. Systemic or topical application of steroids is without response in most cases. Surgical excision showed good results in a few cases. A long-term treatment with oral metronidazol 20 mg/kg/day could be a chance for healing without adverse effects.

Action of gold chloride ("gold toning") on silver-enhanced 1 nm gold markers

In conventional immunoelectron microscopy (IEM), very small colloidal gold particles (0.8-3 nm), or the gold compound Nanogold (1.4 nm) are silver-enhanced for easy detection. However, silver enhancement has drawbacks. First, the silver layer is dissolved during fixation with osmium tetroxide, even if the concentration and incubation time are strongly reduced during pre-embedding labeling experiments in transmission electron microscopic (TEM) and scanning electron microscopic (SEM) studies. Second, after exposure to the electron beam the silver layer may migrate on the section or the whole particles may disappear. Sometimes silver migration can be observed even without irradiation. This effect strongly hampers reinvestigation of previously inspected areas, after some time of storage. In both cases, gold chloride treatment after silver enhancement is sufficient to completely protect the silver-enhanced 1 nm gold markers. Gold chloride treatment is part of the so-called "gold toning" procedure, which is a method used to substitute and/or cover the silver by a layer of gold. It can be applied in TEM and SEM experiments. As a serious drawback, gold chloride treatment slightly reduces the size of both unenhanced and silver-enhanced gold particles and can lead to disintegrated silver/gold particles. Therefore, this technique is useful for pre-embedding IEM, on-(resin)section, and ultrathin cryosection labeling experiments. However, it appears to be unsuitable for double-labeling studies using different gold sizes, for quantitation experiments, and in SEM.

"Cataplexy" and muscle ultrasound abnormalities in Coffin-Lowry syndrome

The Coffin-Lowry syndrome is a rare cause of mental retardation recognised by its distinctive facial and digital features. We have observed an unusual, non-epileptic, cataplexy-like phenomenon in three subjects with the syndrome and we speculate that this feature may go unrecognised. We also provide evidence of neuromuscular dysfunction as part of the phenotype by showing abnormalities on muscle ultrasound in four gene carriers.

[Therapy of orthostatic disorders of cardiovascular regulation. Placebo controlled double-blind study with oxilofrine]

In a double-blind study, the antihypotensive agent oxilofrine was compared with placebo in patients suffering from orthostatic circulatory regulation disorders of the sympathicotonic type. After a washout period of one week, 30 patients were treated for two weeks with oxilofrine and 30 with placebo. The area of the blood pressure amplitude determined with the Schellong test between the 8th minute prone and the 15th minute erect, increased during treatment with oxilofrine from 126 +/- 21 mmHg x min. to 187 +/- 39 mmHg x min. (increase: 48%). The increase under placebo was only 20.8%. The difference in the primary variable was significant. The systolic pressure at the end of treatment with oxilofrine in the Schellong test was virtually constant; under placebo, the systolic pressure decreased.