Understanding the Reactivity and Selectivity of Oxazaborolidium Ion-Catalyzed Diels-Alder Reactions Involving Cyclobutenones as Dienophiles.

The poorly understood factors controlling the reactivity and selectivity (both stereo- and enantioselectivity) of catalyzed Diels-Alder reactions involving cyclobutenones as dienophiles have been analyzed in detail by means of Density Functional Theory calculations. To this end, the reactions with cyclopentadiene and furan as dienes and 3-(methoxycarbonyl)cyclobutenone catalyzed by Corey's chiral oxazaborolidium ion (COBI) have been selected and compared to their analogous uncatalyzed transformations. The combined Activation Strain Model of reactivity and Energy Decomposition Analysis methods have been used to quantitatively understand the acceleration and selectivity induced by the catalyst in this reaction.

Understanding the Reactivity of Diazaborinines towards the Activation of σ-Bonds.

The poorly understood factors governing the small molecule activation reactions mediated by diazaborinines have been computationally explored in detail using quantum chemical tools. To this end, the activation of E-H σ-bonds (E = H, C, Si, N, P, O, S) has been investigated. These reactions, which proceed in a concerted manner, are exergonic and, in general, associated with relatively low activation barriers.

η -Metalated Aryl Iodides in Diels-Alder Cycloaddition Reactions: Mode of Activation and Catalysis.

The potential application of η -metalated aryl iodides as organocatalyst has been explored by means of computational methods. It is found that the enhanced halogen bonding donor ability of these species, in comparison with their demetalated counterparts, translates into a significant acceleration of the Diels-Alder cycloaddition reaction involving cyclohexadiene and methyl vinyl ketone. The factors behind this acceleration, the endo-exo selectivity of the process and the influence of the nature of the transition metal fragment in the activity of these species are quantitatively explored in detail by means of the combination of the Activation Strain Model of reaction and the Energy Decomposition Analysis methods.

Origin of Catalysis and Selectivity in Lewis Acid-Promoted Diels-Alder Reactions Involving Vinylazaarenes as Dienophiles.

The poorly understood factors controlling the catalysis and selectivity in Lewis acid-promoted Diels-Alder cycloaddition reactions involving vinylazaarenes as dienophiles have been quantitatively explored in detail by means of computational methods. With the help of the activation strain model and the energy decomposition analysis methods, it is found that the remarkable acceleration induced by the catalysis is mainly due to a significant reduction of the Pauli repulsion between the key occupied π-molecular orbitals of the reactants and not due to the proposed stabilization of the lowest unoccupied molecular orbital (LUMO) of the dienophile. This computational approach has also been helpful to understand the reasons behind the extraordinary regio- and diastereoselectivity observed experimentally.

Thymic Polypeptide Fraction Biomodulina T Decreases Exhausted and Terminally Differentiated EMRA T Cells in Advanced Lung Cancer Patients Treated With Platinum-Based Chemotherapy.

Lung cancer is the second cause of cancer related deaths worldwide. Chemotherapy and immunotherapy represent the current standard of care for advanced NSCLC. Platinum-based chemotherapy expands late-differentiated T cell populations.

Nature of the Hydrogen Bond Enhanced Halogen Bond.

The factors responsible for the enhancement of the halogen bond by an adjacent hydrogen bond have been quantitatively explored by means of state-of-the-art computational methods. It is found that the strength of a halogen bond is enhanced by ca. 3 kcal/mol when the halogen donor simultaneously operates as a halogen bond donor and a hydrogen bond acceptor.

Catalysis by Bidentate Iodine(III)-Based Halogen Donors: Surpassing the Activity of Strong Lewis Acids.

The poorly understood mode of activation and catalysis of bidentate iodine(III)-based halogen donors have been quantitatively explored in detail by means of state-of-the-art computational methods. To this end, the uncatalyzed Diels-Alder cycloaddition reaction between cyclohexadiene and methyl vinyl ketone is compared to the analogous process mediated by a bidentate iodine(III)-organocatalyst and by related, highly active iodine(I) species. It is found that the bidentate iodine(III)-catalyst accelerates the cycloaddition by lowering the reaction barrier up to 10 kcal mol compared to the parent uncatalyzed reaction.

A 5-year multicentre randomized controlled trial comparing personalized, frozen and fresh blastocyst transfer in IVF.

Research Question: Does clinical performance of personalized embryo transfer (PET) guided by endometrial receptivity analysis (ERA) differ from frozen embryo transfer (FET) or fresh embryo transfer in infertile patients undergoing IVF?

Design: Multicentre, open-label randomized controlled trial; 458 patients aged 37 years or younger undergoing IVF with blastocyst transfer at first appointment were randomized to PET guided by ERA, FET or fresh embryo transfer in 16 reproductive clinics.

Results: Clinical outcomes by intention-to-treat analysis were comparable, but cumulative pregnancy rate was significantly higher in the PET (93.6%) compared with FET (79.

Oocyte donation outcome after oncological treatment in cancer survivors.

Objective: To study reproductive outcome in patients cured of cancer who required oocyte donation (OD) owing to iatrogenic ovarian dysfunction.

Design: Multicenter, unmatched, retrospective cohorts study.

Setting: Private, university-affiliated group of clinics.

Treatment of luteal phase defects in assisted reproduction.

Abnormal luteal function is a common issue in assisted reproduction techniques associated with ovarian stimulation probably due to low levels of LH in the middle and in the late luteal phase. This defect seems to be associated with supraphysiological steroid levels at the end of follicular phase. The luteal phase insufficiency has not got a diagnostic test which has proven reliable in a clinical setting.

The role of LH in ovarian stimulation.

LH is a glycoprotein that plays a crucial role in folliculogenesis during the natural ovarian cycles. It has the same activity and shares receptors with hCG. However the use of LH in combination with FSH in controlled ovarian stimulation remains controversial.