Simultaneous direct measurement of the electrocaloric and dielectric dynamics of ferroelectrics with microsecond temporal resolution.

A contactless technique for direct time-resolved measurements of the full dynamics of the adiabatic temperature change in electrocaloric materials is introduced. The infrared radiation emitted by the electrocaloric sample is sensitively detected with µs time resolution and mK temperature resolution. We present time-resolved measurements of the electrocaloric effect up to kHz frequencies of the driving electric field and down to small field strengths. The simultaneous recording of transients for applied electric field and induced polarization gives a comprehensive view of the correlation of electrocaloric and ferroelectric properties. The technique can further be applied to the continuous measurement of fatigue for >106 electric field cycles.

Towards Bose-Einstein condensation of semiconductor excitons: the biexciton polarization effect.

We theoretically predict a strong influence of stimulated exciton-exciton scattering on semiconductor luminescence. The stimulated scattering causes circularly polarized instead of unpolarized emission at the biexciton emission line in a degenerate gas of partly spin polarized excitons. The biexciton polarization effect increases with increasing exciton densities and decreasing temperatures and approaches almost unity in the ultimate case of Bose-Einstein condensation. Time- and polarization-resolved luminescence measurements evidence the biexciton polarization effect both in ZnSe and GaAs quantum wells.

Spin noise spectroscopy in GaAs.

We observe the noise spectrum of electron spins in bulk GaAs by Faraday-rotation noise spectroscopy. The experimental technique enables the undisturbed measurement of the electron-spin dynamics in semiconductors. We measure exemplarily the electron-spin relaxation time and the electron Landé g factor in -doped GaAs at low temperatures and find good agreement of the measured noise spectrum with a theory based on Poisson distribution probability.

Anomalous spin dephasing in (110) GaAs quantum wells: anisotropy and intersubband effects.

A strong anisotropy of electron spin decoherence is observed in GaAs/(AlGa)As quantum wells grown on a (110) oriented substrate. The spin lifetime of spins perpendicular to the growth direction is about one order of magnitude shorter compared to spins along [110]. The spin lifetimes of both spin orientations decrease monotonically above temperatures of 80 and 120 K, respectively. The decrease is very surprising for spins along the [110] direction and cannot be explained by the usual Dyakonov-Perel dephasing mechanism. A novel spin dephasing mechanism is put forward that is based on scattering of electrons between different quantum well subbands.

Ultrafast terahertz probes of transient conducting and insulating phases in an electron-hole gas.

Many-body systems in nature exhibit complexity and self-organization arising from seemingly simple laws. For example, the long-range Coulomb interaction between electrical charges has a simple form, yet is responsible for a plethora of bound states in matter, ranging from the hydrogen atom to complex biochemical structures. Semiconductors form an ideal laboratory for studying many-body interactions of electronic quasiparticles among themselves and with lattice vibrations and light. Oppositely charged electron and hole quasiparticles can coexist in an ionized but correlated plasma, or form bound hydrogen-like pairs called excitons. The pathways between such states, however, remain elusive in near-visible optical experiments that detect a subset of excitons with vanishing centre-of-mass momenta. In contrast, transitions between internal exciton levels, which occur in the far-infrared at terahertz (1012 s(-1)) frequencies, are independent of this restriction, suggesting their use as a probe of electron-hole pair dynamics. Here we employ an ultrafast terahertz probe to investigate directly the dynamical interplay of optically-generated excitons and unbound electron-hole pairs in GaAs quantum wells. Our observations reveal an unexpected quasi-instantaneous excitonic enhancement, the formation of insulating excitons on a 100-ps timescale, and the conditions under which excitonic populations prevail.

Is pelvic inflammatory disease an indication for treatment with ciprofloxacin?

This pilot study was carried out on 23 gynaecological patients suffering from salpingitis, salpingitis and pelviperitonitis, Douglas' abscess, and vaginal stump abscess. 21 courses were evaluable for clinical efficacy. The diagnoses had been established mainly by pelviscopy and by clinical gynaecological examinations. The dosage was 2 X 500 mg ciprofloxacin orally every 12 h for 7.6 (5-11) days. Cervical smears collected before therapy revealed the most common pathogens to be Escherichia coli and staphylococci, followed by Proteus mirabilis and streptococci. Clinically ciprofloxacin produced a complete cure in 16 patients (76%), and a clear improvement in four patients (19%). One patient left hospital before completing the therapy. Laboratory tests did not reveal any pathological findings, and ophthalmological examinations (fundoscopy, visus, colour perception) on 16 patients, before and after treatment, likewise did not show any changes. In one patient, therapy had to be discontinued after three days because of pruritic exanthema and vertigo. A second patient complained of strong pain behind the eyes and headache. In both patients these symptoms disappeared completely on discontinuation of treatment. The study showed clinical efficacy of orally administered ciprofloxacin in pelvic inflammatory disease.

Fenoterol depot and fenoterol in premature uterine contractions--a multicentric double-blind comparative study.

In a double-blind randomized study, the effect of a single dose of a fenoterol preparation with delayed release of active substance (designated as fenoterol depot) was compared with a fenoterol product with undelayed release of active substance (designated as fenoterol) in two groups respectively comprising 66 and 65 female patients with premature uterine contractions. The fenoterol depot was administered p.o. in a single total dose of 21 mg at the beginning of an investigation period of 360 minutes and the fenoterol was administered p.o. within 235 minutes in three identical consecutive doses resulting in a total dose of 22.5 mg. The increased uterine activity present at the beginning was markedly lowered by an initial intravenous infusion of Partusisten. After administration of the two oral preparations, the uterine contractions remained at the low level achieved. The fenoterol depot was slightly superior to fenoterol with regard to the reduction of the duration of contractions: the difference in the inhibition of the duration of the contraction between the two preparations was a maximum of 25.7% in favor of fenoterol depot. The frequency of uterine contraction was substantially reduced by both preparations, but to a greater extent by the depot form. The tocolytic efficacy and the tolerance were rated as "good" in 70% and 75% respectively with fenoterol depot and in 69% and in 71% respectively in the case of fenoterol. The maternal pulse rate remained at the level reached at the end of Partusisten infusion with the two preparation, and the blood pressure fluctuated slightly within the normal range.(ABSTRACT TRUNCATED AT 250 WORDS)

[Prevention of infection in hysterectomy by local preoperative antibiotics]. / Infektionsprophylaxe bei Hysterektomien durch lokale präoperative Antibiose.

By once-only administration of a vaginal ovulum containing tetracyclin (Mysteclin) in the evening prior to surgery wound infections, in particular following vaginal hysterectomies, are significantly reduced. This does not apply to the infection parameters fever and urinary tract infections, which are not influenced by local preoperative antibiosis. The method should only be used in cases with a low primary infection risk, where it is justified by virtue of the simlicity of performing it, its lack of complications, and its low cost.

[Perioperative CTG in cesarean section]. / Das perioperative CTG bei der Sectio.

In 30 cases each of primary (intact amnion) and secondary (ruptured amnion) cesarean section continuous perioperative cardiographic monitoring of the fetus was performed. When primary cesarean section is performed, perioperative monitoring extending to delivery of the fetus is not generally necessary, provided the preoperative CTG is normal and the patient is positioned on her left on the operating table. In secondary cesarean section with normal CTG continuous perioperative monitoring of the fetus is also unnecessary. If secondary cesarean section is performed when the amnion is ruptured and the CTG is pathologic, the fetus should be cardiotocographically monitored up to delivery, to permit the speed of preparation and performance of the operation to be adapted to the condition of the fetus and any necessary preparations for reanimation to be made.

[Do extended preventive indications for cervix cerclage increase labor complications? A statistical analysis on direct and indirect complications of cerclage using Bavarian perinatal data 1978-1980]. / Bewirkt die erweiterte prophylaktische Indikationsstellung zur Zervixcerclage eine Erhöhung der Geburtskomplikationen?--Eine statistische Analyse über direkte und indirekte Komplikationen der Cerclage mit Hilfe der Bayerischen Perinatalerhebung von 1978-1980.

On the basis of 159.710 single pregnancies with 11.321 cerclages documented in the Bavarian Perinatal Survey of 1978-1980, with 2.676 single-child births, and 514 cerclages performed on the authors' own patients, possible complications of the extended indication for cerclage were determined as follows: The late abortion rate was not increased. Possibly because the group represented a negative selection, rupture of the membranes prior to labour, infant mortality due to infection, and premature labour were significantly more common in gravidae who had undergone cerclage. However, it was not possible to identify a causal connection between these and the cerclage operation. With regard to indirect complications there was an appreciable increase in the number of caesarean deliveries among cerclage patients, a slight increase in the number of cases in which labour lasted over 12 hours, and a significant increase in the number of lacerations of the cervix. There was no increase in the incidence of post-term births, malformations, stillbirths, or infantile acidosis among the children of patients who had undergone cerclage.

[Can premature birth rate be reduced by preventive cerclage? A retrospective statistical analysis on the effect and value of cerclage using the Bavarian Perinatal Survey 1978-1980]. / Kann durch die prophylaktische Cerclage die Frühgeburtenrate gesenkt werden? Eine retrospektive statistische Analyse über Wirkung und Wertigkeit der Cerclage mit Hilfe der Bayerischen Perinatalerhebung (BPE) der Jahre 1978-1980.

There is no simple correlation between cerclage rates and premature birth-rates. This concludes that premature birth-rates cannot be reduced by extending the cerclage. In all comparable categories the premature birth-rate was higher in groups which used the cerclage than those ones which did not use the cerclage even though a) the risk of social economical premature birth-rates was reduced and b) care was intensified for pregnancy cases. Cerclage groups have a higher percentage of case history risks than the non-cerclage groups. There is a direct relationship between the social status and the premature births. The case history of premature birth risks cannot be reduced using the cerclage especially with women who have previously had 2 abortions or premature births. When placenta previa occurs the cerclage does not reduce premature births. In the case of cervix insufficiency and early labor the cerclage reduces the premature birth-rate. Extended prophylactic cerclage cannot be used to diminish premature births.

[Can by preventive cervix cerclage the premature birth rate in multiple pregnancy be reduced? A retrospective statistical analysis on effectiveness of cerclage using the Bavarian Perinatal Survey 1978-1980]. / Kann durch die prophylaktische Zervix-Cerclage die Frühgeburtenrate bei Mehrlingen gesenkt werden? Eine retrospektive statistische Analyse über die Effektivität der Cerclage mit Hilfe der BPE von 1978-1980.

Through a retrospective statistical analyzation of 3081 multiple births with 907 cerclage of BPE from 1978-1980, among which included 77 multiple births and 61 Cerclage cases of the Amberg gynecology clinic, could be proved that the liberal use of prophylactic cerclages could not reduce the premature birth rate of multiple birth pregnancies.

[Perioperative infection prevention with cefotaxime]. / Perioperative Infektionsprophylaxe mit Cefotaxim.

In a study comprising 172 patients who had been abdominally or vaginally hysterectomised, the effectivity of short-term prophylaxis with cefotaxim on various infection parameters was examined. The 100 patients of the prophylaxis group showed a significant reduction (p less than 0.01) of postoperative fever and of pelvic infections after vaginal hysterectomies. With abdominal hysterectomies, wound infections and pelvic infections were not reduced so strikingly. Infections of the urinary tract were seen less frequently in the prophylaxis group. Perioperative short-term prophylaxis is meaningful in vaginal hysterectomies, whereas in abdominal hysterectomies such prophylaxis will be useful only in cases with enhanced risk of infection.

[Results of sling surgery using Tutoplast dura]. / Ergebnisse nach Schlingenoperation mit Tutoplast-Dura.

From 1976-1979 127 patients were treated with a tutoplast dura sling operation. Either an open or a closed sling was used. Between one and four and one half years later 117 patients were re-examined and 65 patients had urodynamic tests. The late results of tutoplast dura sling operations are good and compare favorably to the upper data indicated in the literature. The best results are obtained in cases of prolapse. The closed sling has higher success rates but also higher complication rates than the open sling. Primary operations have better results than operations for recurrence. A severe stress incontinence should be subjected to specific primary treatment.

[Determination of concentration of an antibiotic (Cefotaxim) in the vaginal mucosa after preoperative intravenous administration]. / Konzentrationsbestimmung eines Antibiotikums (Cefotaxim) in der Vaginal-haut nach präoperativer intravenöser Gabe.

In 11 patients in whom an antibiotic (Cefotaxim) had been applied preoperatively, the tissue concentration was determined in the vaginal mucosa where postoperative infections after gynaecological operations are most common. The tissue concentration is compared with the minimum inhibition concentration of the pathogens identified directly before the operation in the cervicovaginal flora. In the case of the aerobic pathogens--with the exception of Pseudomonas aeruginosa--the concentration is far in excess of the necessary MIC, whereas with the anaerobic pathogens the concentration is only partly greater than the MIC. Resistance exists against Bacteroides fragilis.

[Proof of beta-2-adrenergic activity of etilefrin (effortil) via aimed recording of its tocolytic action (author's transl)]. / Nachweis der beta-2-adrenergen Wirkung von Etilefrin (Effortil) durch gezielte Registrierung seines tokolytischen Effektes.

In 21 normal deliveries the intrauterine pressure was measured continuously during the first stage of labor. Thus the tocolytic efficiency of Etilefrin was revealed. Intensity and duration of the tocolytic effect were related to the dose. Pressure and frequency of the contractions were diminished. Therefore these results are conclusive that Etilefrin, generally given for its alpha- and beta 1 mimetic effects, has an additional beta 2-mimetic and tocolytic component.