(2Z,2′Z,4E,4′E)-4,4′-(Cyclo­hexane-1,2-diyldinitrilo)dipent-2-en-2-ol

A new tetra­dentate chiral Schiff base ligand, C16H26N2O2, has been synthesized by the reaction of acetyl­acetone with (1R,2R)-(−)-1,2-diamino­cyclo­hexane. Both of the mol­ecules in the asymmetric unit are of the same chirality (R configuration), since the absolute configuration was determined by the starting reagent (1R,2R)-(−)-1,2-diamino­cyclo­hexane. The six-membered cyclo­hexane ring is in a chair conformation, and the substituents are equatorial in the most stable conformation (trans-cyclo­hexyl). At the ring substituents, large conjugated —C=N—CH=C—OH systems exist, resulting from the original ketone converted into the enol form. With H atoms excluded, the atoms of each substituent lie in the same plane. The two mol­ecules in the asymmetric unit have almost the same structure, with slight differences in the torsion angles between the substituents and the cyclo­hexane ring; the corresponding N1—(C—C—C)cyclo­hexa­ne torsion angles are −177.2 (3) and 179.3 (4)° in one mol­ecule and −176.5 (3) and 178.4 (4)° in the other. Two intra­molecular O—H⋯N hydrogen bonds exist in each mol­ecule

Top Rank Optimization in Linear Time

Bipartite ranking aims to learn a real-valued ranking function that orders positive instances before negative instances. Recent efforts of bipartite ranking are focused on optimizing ranking accuracy at the top of the ranked list. Most existing approaches are either to optimize task specific metrics or to extend the ranking loss by emphasizing more on the error associated with the top ranked instances, leading to a high computational cost that is super-linear in the number of training instances. We propose a highly efficient approach, titled TopPush, for optimizing accuracy at the top that has computational complexity linear in the number of training instances. We present a novel analysis that bounds the generalization error for the top ranked instances for the proposed approach. Empirical study shows that the proposed approach is highly competitive to the state-of-the-art approaches and is 10-100 times faster

Is interleukin-18 associated with polycystic ovary syndrome?

<p>Abstract</p> <p>Background</p> <p>Recent research show that polycystic ovary syndrome (PCOS) may have an association with low-grade chronic inflammation, IL-18 is considered as a strong risk marker of inflammation.</p> <p>Methods</p> <p>To investigate serum IL-18 concentrations in PCOS patients and focus on its relationship between obesity and insulin resistance (IR). Sixty consecutive women with PCOS and thirty controls were recruited. Serum level of IL-18 and fasting blood glucose, fasting insulin, follicle-stimulating hormone (FSH), luteinizing hormone (LH) and testosterone (T) were measured.</p> <p>Results</p> <p>Serum levels of IL-18 was significantly higher in the PCOS group than in the control group. Serum level of IL-18 was higher in the PCOS group with IR than in the PCOS group without IR. Serum level of IL-18 was higher in obese PCOS patients than in lean PCOS patients. Serum level of IL-18 was higher in lean PCOS patients than in the lean control group. Serum level of IL-18 in the PCOS group was positively related to BMI, IR index and T.</p> <p>Conclusion</p> <p>IL-18 level was increased in PCOS patients, and correlated with insulin resistance, obesity and hyperandrogenism.</p