Ultrafast demagnetization at high temperatures.

Time-resolved pump-probe measurements were made at variable heat accumulation in Co/Pd superlattices. Heat accumulation increases the baseline temperature and decreases the equilibrium magnetization. Transient ultrafast demagnetization first develops with higher fluence in parallel with strong equilibrium thermal spin fluctuations. The ultrafast demagnetization is then gradually removed as the equilibrium temperature approaches the Curie temperature. The transient magnetization time-dependence is well fit with the spin-flip scattering model.

Demagnetizing fields in all-optical switching.

A model of demagnetizing fields and micromagnetic simulations are applied to examine the evolution of a demagnetized cylinder. In addition to three expected final magnetic structures, a fourth switched state is obtained over a range of magnetic energy densities. The switched state is absent when demagnetizing fields are neglected. The connection to all-optical switching of materials with perpendicular magnetic anisotropy is discussed.

Heat accumulation and all-optical switching by domain wall motion in Co/Pd superlattices.

All-optical switching by domain wall motion has been obtained in Co/Pd superlattices with a TiS oscillator. Heat accumulation is part of the switching process for our experimental conditions. Numerical calculations point to a connection between domain wall motion and in-plane heat diffusion.

CT-guided bipolar and multipolar radiofrequency ablation (RF ablation) of renal cell carcinoma: specific technical aspects and clinical results.

PURPOSE: This study was designed to evaluate the clinical efficacy of CT-guided bipolar and multipolar radiofrequency ablation (RF ablation) of renal cell carcinoma (RCC) and to analyze specific technical aspects between both technologies. METHODS: We included 22 consecutive patients (3 women; age 74.2 ± 8.6 years) after 28 CT-guided bipolar or multipolar RF ablations of 28 RCCs (diameter 2.5 ± 0.8 cm). Procedures were performed with a commercially available RF system (Celon AG Olympus, Berlin, Germany). Technical aspects of RF ablation procedures (ablation mode [bipolar or multipolar], number of applicators and ablation cycles, overall ablation time and deployed energy, and technical success rate) were analyzed. Clinical results (local recurrence-free survival and local tumor control rate, renal function [glomerular filtration rate (GFR)]) and complication rates were evaluated. RESULTS: Bipolar RF ablation was performed in 12 procedures and multipolar RF ablation in 16 procedures (2 applicators in 14 procedures and 3 applicators in 2 procedures). One ablation cycle was performed in 15 procedures and two ablation cycles in 13 procedures. Overall ablation time and deployed energy were 35.0 ± 13.6 min and 43.7 ± 17.9 kJ. Technical success rate was 100 %. Major and minor complication rates were 4 and 14 %. At an imaging follow-up of 15.2 ± 8.8 months, local recurrence-free survival was 14.4 ± 8.8 months and local tumor control rate was 93 %. GFR did not deteriorate after RF ablation (50.8 ± 16.6 ml/min/1.73 m(2) before RF ablation vs. 47.2 ± 11.9 ml/min/1.73 m(2) after RF ablation; not significant). CONCLUSIONS: CT-guided bipolar and multipolar RF ablation of RCC has a high rate of clinical success and low complication rates. At short-term follow-up, clinical efficacy is high without deterioration of the renal function.

Role of long-range intermolecular forces in the formation of inorganic nanoparticle clusters.

An understanding of the role played by intermolecular forces in terms of the electron density distribution is fundamental to the understanding of the self-assembly of molecules in the formation of a molecular crystal. Using ab initio methods capable of describing both short-range intramolecular interactions and long-range London dispersion interactions arising from electron correlation, analyses of inorganic dimers of As(4)S(4) and As(4)O(6) molecules cut from the structures of realgar and arsenolite, respectively, reveal that the molecules adopt a configuration that closely matches that observed for the crystal. Decomposition of the interaction energies using symmetry-adapted perturbation theory reveals that both model dimers feature significant stabilization from electrostatic forces as anticipated by a Lewis acid/Lewis base picture of the interaction. London dispersion forces also contribute significantly to the interaction, although they play a greater role in the realgar structure near equilibrium than in arsenolite.

Epidermodysplasia verruciformis in a HIV-positive patient homozygous for the c917A-->T polymorphism in the TMC8/EVER2 gene.

BACKGROUND: Epidermodysplasia verruciformis (EV) is a rare autosomal-recessive disorder characterized by widespread and persistent infection with human papilloma virus (HPV) and a risk of malignant degeneration. Most cases of EV are caused by mutations in the two EV genes, EVER1/TMC6 and EVER2/TMC8. The clinical presentation of EV takes two different forms, which coexist in most cases. Over a period of years, patients develop plane warts and pityriasis versicolor-like lesions. Sixteen cases of EV in HIV-positive patients have been clinically investigated and reported in the literature. However, different inherited susceptibilities towards HPV infection in immunodeficient patients, like HIV-positive patients, have only rarely been addressed. OBSERVATION: We describe a 22-year-old female patient with a congenital HIV infection, who presented with slowly progressing and confluent erythematous papules on her hands and hypopigmented macules on her extremities. The histopathology was typical for EV, and HPV5 was detected by PCR and reverse hybridization. The 44-year-old HIV-positive mother has no typical EV lesions. The patient is homozygous for an A to T single nucleotide polymorphism (SNP) at position 917 of the TMC8/EVER2 gene. The mother of the patient is heterozygous for this SNP. CONCLUSION: These results support the hypothesis that the combination of immunodeficiency and a susceptibility allele may contribute to the differences in occurrence of EV in HIV-positive patients.

[Diagnosis of endolymphatic hydrops using low frequency modulated distortion product otoacoustic emissions]. / Diagnostik des endolymphatischen Hydrops mit tieftonmodulierten DPOAE.

BACKGROUND: The low frequency modulation of distortion product otoacoustic emissions (DPOAEs) is an objective audiometric method that appears to be a useful tool for the diagnosis of endolymphatic hydrops (EH), e.g. in patients with Menière's disease, or in those who present only some of the symptoms of the disease. METHOD: Low-frequency modulated DPOAEs were registered in 20 patients with unilateral Menière's disease (13 women and 7 men, aged 40-66 years) and were compared to a control group matched in age and gender. As a diagnostic parameter, the 'modulation index' MI=1/2 MS/DM was used (MS or modulation span, being the difference between the maximal and the minimal DPOAE-amplitude, and DM, being the mean of the suppressed stationary DPOAE-amplitude). RESULTS: In the patients with unilateral Menière's disease, MI was lower than in the control group. This difference was highly significant. In 56% of the patients' contralateral ears MI was lower than the cut off-value and significantly lower than in the control group, but did not differ significantly from the patients' ipsilateral ears. CONCLUSION: The registration of low-frequency modulated DPOAEs is comparable to the generally applied transtympanic electrocochleography in its diagnostic validity. The method is fast and non-invasive and could be applied to monitor the course of the disease.

Cutaneous myiasis due to Dermatobia hominis.

Cutaneous myiasis caused by the human botfly Dermatobia hominis involves the infestation of tissue with dipterous fly larvae and is common in the neotropical region of the New World. We report a case of D. hominis imported in Switzerland from Costa Rica. In the past, various approaches to extract the botfly larva have been reported.

[Aural fullness and endolymphatic hydrops]. / Druckgefühl im Ohr bei endolymphatischem Hydrops.

BACKGROUND: Low-frequency modulated DPOAEs were registrated to investigate whether the subjective symptom of aural fullness can indicate an endolymphatic hydrops. METHOD: The cochlear partition is periodically moved towards scala vestibuli and scala tympani by a low-frequency suppressor tone. The level of simultaneously registrated DPOAEs is modulated depending on the phase of the suppressor. This modulation may be reduced when the displacement of the organ of Corti is inhibited by mechanical stiffening of the basilar membrane (e. g. in endolymphatic hydrops). SUBJECTS: Low-frequency modulated DPOAEs were registrated in 15 patients with Menière's disease, in 8 patients with aural fullness and tinnitus, but without vertigo, and in 21 normal hearing adults. RESULTS: In both patient groups the modulation depth is high significantly lower than in the control group. The results do not differ significantly in the patients with and without vertigo. CONCLUSION: The reduction of the modulation depth can be interpreted as a sign of an endolymphatic hydrops. In the group of patients with aural fullness a cochlear hydrops can be assumed. The measurement of low-frequency modulated DPOAEs is a new tool to diagnose and monitor the course of endolymphatic hydrops and to evaluate the effectiveness of therapeutic methods.