InterCarb: A Community Effort to Improve Interlaboratory Standardization of the Carbonate Clumped Isotope Thermometer Using Carbonate Standards

Increased use and improved methodology of carbonate clumped isotope thermometry has greatly enhanced our ability to interrogate a suite of Earth-system processes. However, interlaboratory discrepancies in quantifying carbonate clumped isotope (Δ47) measurements persist, and their specific sources remain unclear. To address interlaboratory differences, we first provide consensus values from the clumped isotope community for four carbonate standards relative to heated and equilibrated gases with 1,819 individual analyses from 10 laboratories. Then we analyzed the four carbonate standards along with three additional standards, spanning a broad range of δ47 and Δ47 values, for a total of 5,329 analyses on 25 individual mass spectrometers from 22 different laboratories. Treating three of the materials as known standards and the other four as unknowns, we find that the use of carbonate reference materials is a robust method for standardization that yields interlaboratory discrepancies entirely consistent with intralaboratory analytical uncertainties. Carbonate reference materials, along with measurement and data processing practices described herein, provide the carbonate clumped isotope community with a robust approach to achieve interlaboratory agreement as we continue to use and improve this powerful geochemical tool. We propose that carbonate clumped isotope data normalized to the carbonate reference materials described in this publication should be reported as Δ47 (I-CDES) values for Intercarb-Carbon Dioxide Equilibrium Scale.

[Listeriosis during pregnancy (author's transl)]

Eight cases of materno-fetal listeriosis were discovered at the University Women's Hospital of Basel from May 1977 until June 1980. This represent an incidence of 0,15% of all births. This infectious disease has often a fatal course for the unborn child, therefore it is important to know the clinical manifestations occurring with it. Listeriosis during pregnancy has a typical-two-stage course: During the first phase we see commonly a flu-like illness abating rapidly, about two weeks later fever starts again and premature contractions ensue, but no therapy is successful in controlling the fever and the premature labour. The usual fate for the unborn child is stillbirth or premature delivery with subsequent neonatal death due to prematurity, RDS, sepsis and meningitis. The low fetal and neonatal survival rate can be improved by two relatively simple measures: 1) a high index of suspicion with early diagnosis, 2) an early treatment with ampicillin either in the antepartal or neonatal stage. We review the epidemiology, the bacteriology, the serology and the histo-pathology of this relatively rare but important disease during pregnancy.

Isolation of Chlamydia trachomatis from women with urethral syndrome

Urethral swabs were examined for Chlamydia trachomatis in 22 women suffering from urethral syndrome and in an age-matched control group without genito-urinary symptoms. Full urodynamic investigation was done in patients with urinary symptoms. In this group the isolation rate of C. trachomatis was significantly higher than in the control group (59% versus 13%, P less than 0.01). Therefore C. trachomatis must be considered as one of the possible causes of the female urethral syndrome. Five out of eight patients with positive culture who were treated with minocycline had a negative follow-up culture and the clinical results of this treatment were variable.

Interstitial pregnancy following ipsilateral salpingo-oophorectomy

A case of interstitial pregnancy, which occurred 12 years after ipsilateral salpingo-oophorectomy, was managed by cornual wedge resection. Internal (transuterine) migration of the fertilized ovum is the most probable explanation for this ectopic gestation. During the past 10 years three other cases of interstitial gestation have been managed at St. Michael's Hospital, Toronto, an incidence of 3% of all ectopic pregnancies seen at the hospital during that period.