Heat-capacity measurements under uniaxial pressure using a piezo-driven device.

We report the development of a technique to measure heat capacity at large uniaxial pressure using a piezoelectric-driven device generating compressive and tensile strain in the sample. Our setup is optimized for temperatures ranging from 8 K down to millikelvin. Using an AC heat-capacity technique, we are able to achieve an extremely high resolution and to probe a homogeneously strained part of the sample. We demonstrate the capabilities of our setup on the unconventional superconductor Sr2RuO4. By replacing thermometer and adjusting the remaining setup accordingly, the temperature regime of the experiment can be adapted to other temperature ranges of interest.

Charge-doping-driven evolution of magnetism and non-Fermi-liquid behavior in the filled skutterudite CePt4Ge(12-x)Sb(x).

The filled skutterudite compound CePt(4)Ge(12) is situated close to the border between the intermediate valence of Ce and heavy-fermion behavior. Substitution of Ge by Sb drives the system into a strongly correlated and, ultimately, upon further increasing the Sb concentration, an antiferromagnetically ordered state. Our experiments evidence a delicate interplay of emerging Kondo physics and the formation of a local 4f moment. An extended non-Fermi-liquid region, which can be understood in the framework of a Kondo-disorder model, is observed. Band-structure calculations support the conclusion that the physical properties are governed by the interplay of electron supply via Sb substitution and the concomitant volume effects.

Nature of the A phase in CeCu2Si2.

Neutron diffraction experiments have been performed on a magnetically ordered CeCu2Si2 single crystal exhibiting A-phase anomalies in specific heat and thermal expansion. Below T(N) approximately 0.8 K antiferromagnetic superstructure peaks have been detected. The propagation vector of the magnetic order appears to be determined by the topology of the Fermi surface of heavy quasiparticles as indicated by renormalized band-structure calculations. The observation of long-range incommensurate antiferromagnetic order as the nature of the A phase in CeCu2Si2 suggests that a spin-density-wave instability is the origin of the quantum critical point in CeCu2Si2.

Daily and circadian variations in serum free testosterone levels are not clinically significant.

Serum free testosterone levels were measured daily during an ovulatory, endocrinologically normal cycle in five women and at 6-hour intervals on six consecutive days near midcycle in four of these women. During ovulatory cycles, serum free and total testosterone, unlike the gonadotropins, estradiol, and progesterone, did not fluctuate in a cyclic pattern. The 6-hour assays demonstrated close parallelism of free and total testosterone levels and no circadian pattern similar to the diurnal variation seen in serum cortisol values. During both study intervals, the serum free testosterone levels rarely exceeded the upper limit of the normal range defined for our laboratory. Thus, serum free testosterone values measured in blood samples obtained at any day are equally reliable for clinical use.

Detection of the pre-ovulatory period using a vaginal probe in the home.

Through seven of eight consecutive cycles, a volunteer used an opto-electronic vaginal probe to record at home her daily values of vaginal back-scattering (VBS) of infrared light, at the same time as taking her daily oral temperature (BBT). Under the basal conditions used, VBS reflects vaginal changes influenced by estrogenic hormones. Each of the seven VBS curves showed a characteristic rise and fall during the first part of the cycle, preceding both inguinal pain and the BBT midcycle minimum. Periods of likely high fertility could be defined by two criteria which were applicable to all cycles recorded in this subject, and recognizable at the time of observation.

Transducer probe for the measurement of oestradiol-induced changes in the vagina of ovariectomized ewes.

A modified non-invasive vaginal probe, using electronic transducers to monitor six physical variables reflecting vaginal changes, was tested in oophorectomized ewes according to a Latin-Square design allocating six treatments to six animals in a balanced time sequence. The transducers measured thermal conductance, temperature near the cervix and near the vulva, and light reflectance at 900, 660, and 565 nm. The treatments included four iv doses of oestradiol-17 beta (0.5, 5.0, 50, and 500 microgram per 50 kg body weight) and two controls (injection vehicle, and no injection). Despite large residual variation, the results (1) show that the higher oestradiol doses produced responses of all six variables; (2) suggest improvements in future probe design; and (3) raise interesting questions on dose-response relationships deserving further study.

A bio-implantable solid-state camera for long-term video-recording of abdominal organs in situ.

A new solid-state camera was constructed and implanted in sheep. It permits continuous or selective video-recording of the ovary in the unrestrained animal during an entire oestrous cycle (16 days).

The role of oestrogen replacement in the climacteric syndrome.

Using a double-blind placebo-controlled cross-over design, the effect of equine conjugated oestrogens tablets (Premarin) was studied in 20 women with the climacteric syndrome followed during 15 months. Sixteen women were equally improved on placebo and oestrogen. Only 2 patients had an improved sense of well-being on oestrogen and not on placebo. The psychological diagnosis was unrelated to the subjective response to oestrogen or placebo. Performance in psychological tests administered before and during treatment periods was not changed by oestrogen or placebo.

Effect of progesterone and estradiol-17beta on nucleic acid synthesis in vitro in carcinoma of the endometrium.

Nucleic acid synthesis was studied in 26 tumor specimens, during a one-hour in vitro incubation with the addition of progesterone and estradiol-17beta. On the response scale used, deoxyribonucleic acid and ribonucleic acid synthesis decreased linearly as the logarithmic concentration of either hormone increased. Inhibition of nucleic acid synthesis was highly significant (P less than 0.001) at 80 microgram per milliliter of progesterone and at 40 microgram per milliliter of estradiol. No evidence of synergism was found when the two hormones were combined at these concentrations. In Grade I and II tumors, the effect when both hormones were combined approximated the sum of effects of the individual hormones. In Grade III tumors, little difference was seen between treatment groups.