Configurational preferences of two 1,2-diamine adducts of bis(1-(2-thienyl)-4,4,4-trifluoro-1,3-butanedionato)cobalt(II)

The preparation, the IR and ligand field spectra and the structures of the mixed-ligand addition compounds [(N,N-dimethyl-1,2-diaminoethane)bis(1-(2-thienyl)-4,4,4-trifluoro-1,3-butanedionato)cobalt(II)], [Co(thtf)2me2en], and [(N,N,N′,N′-tetramethyl-1,2-diaminoethane)bis(1-(2-thienyl)-4,4,4-trifluoro-1,3-butanedionato)cobalt(II)], [Co(thtf)2me4en], are reported. The structures were determined by single crystal X-ray diffraction analysis (monoclinic, space group P21/c, Z=4 with a=10.708(6), b=19.531(6), c=13.352(6) Å, β=111.64(10)°, R1=0.0642 and wR2=0.1719 for [Co(thtf)2(me2en)] and a=12.033(6), b=15.565(6), c=15.339(6) Å, β=92.57(6)°, R1=0.0612 and wR2=0.1504 for [Co(thtf)2me4en]). The structures are distorted octahedral and the shortest cobalt–cobalt separation distances are 5.388(2) Å in [Co(thtf)2me2en] and 8.675(3) Å in [Co(thtf)2me4en]. In both compounds the diamine molecules attain the gauche conformation. The U(Z,Z) conformation of the β-dione leads to a semi-chair conformation of the β-dionato chelate rings. The relative orientation of the groups attached to the β-dionato moiety depends on the extent of stereoelectronic effects the N-substitution of the diamine entails. In [Co(thtf)2me2en] the intraligand distance separating the trifluoromethyl carbon atoms is 5.281(18) Å while in [Co(thtf)2me2en] it increases to 8.338(9) Å. The cobalt–cobalt separation distance, the orientation of the chelate rings and the extent of N-substitution seem to affect hydrogen bonding. While in [Co(thtf)2me2en] inter- and intraligand hydrogen bonding is implicated, it is totally absent in [Co(thtf)2me4en].

Ring Contraction of 1,2-Dihydronaphthalenes Promoted by Thallium(III) in Acetonitrile: A Diastereoselective Approach to Indanes

trans-1,3-Disubstituted indanes are conveniently accessed by a stereoselective ring contraction of 1,2-dihydronaphthalenes upon treatment with thallium(III) nitrate (TTN) in acetonitrile. Under these conditions, the oxidative rearrangement of either di- or trisubstituted double bonds is possible.

Avaliação de um Sistema de Produção de Gado de Corte. 1. Desempenho Reprodutivo

Data from 1983 through 1991 on reproductive performance, collected from the Beef Cattle production system at Embrapa Gado do Corte, were analyzed. This system, based on exclusive grazing, presented a pregnancy rate (2-3 years old heifers and cows) of 75.9%. The others observed index were first calving reconception rate, 62.1%, total herd loss rate, 2.2%, and calf loss rate until weaning, 6.0%. The calf loss rate represented 53.7% of the total herd loss rate. For calf loss rate (CLR) data analysis, the used model included the effects of sex (S), calf birth year (ANB), cow birth year (ANV) and the interactions between S x ANB and ANV x ANB. Sex had a significant effect on CLR, with 8.1 and 3.8% for male and female loss rate, respectively. For calving interval analysis, the used model included the following fixed effects: ANV, birth month of cow (MNV), birth cow order when it was a calf (OPV) and the ANV x MNV interaction. The 205-day cow weight and her age at first calving were used as covariables. The calving interval was 463.45 days (15.2 mo), ranging from 388 to 543 days, and it was significantly affected by ANV. It is suggested that more research attention should be directed to the highest loss rate observed for male calves, which represent higher commercial value than females.

Cognitive function in postmenopausal women receiving adjuvant letrozole or tamoxifen for breast cancer in the BIG 1-98 randomized trial

Cognitive function in postmenopausal women receiving letrozole or tamoxifen as adjuvant endocrine treatment was compared during the fifth year of treatment in a substudy of the BIG 1-98 trial. In BIG 1-98 patients were randomized to receive adjuvant (A) 5-years tamoxifen, (B) 5-years letrozole, (C) 2-years tamoxifen followed by 3-years letrozole, or (D) 2-years letrozole followed by 3-years tamoxifen. The primary comparison was the difference in composite score for patients taking letrozole (B+C; N=65) vs. tamoxifen (A+D; N=55). The patients taking letrozole had better overall cognitive function than those taking tamoxifen (difference in mean composite z-scores=0.28, P=0.04, 95% CI: 0.02, 0.54, Cohen's D=0.40 indicating small to moderate effect). In this substudy, breast cancer patients taking adjuvant letrozole during the fifth year of treatment had better cognitive function than those taking tamoxifen, suggesting aromatase inhibitors do not adversely impact cognition compared with tamoxifen.

Na 50 Nachlass Arthur Schopenhauer - 'Schopenhauer-Archiv', 388 - Kopie des Dekrets vom Königlich Preußischen Landgerichts Berlin betreffend der Hypothekenangelegenheit des Schneiderschen Grundstücks zu Alt-Schöneberg

u.a.: Arthur Schopenhauer;

Ms.Ff.F.Stoltze 3. 388 - Brief von Friedrich Stoltze an Alexander Müller

"Dem Gott der Kaufleut und der Diebe"