Chiral carbene–borane adducts: precursors for borenium catalysts for asymmetric FLP hydrogenations

The carbene derived from (1R,3S)-camphoric acid was used to prepare the borane adduct with Piers’ borane 7. Subsequent hydride abstraction gave the borenium cation 8. Adducts with 9-BBN and the corresponding (1R,3S)-camphoric acid-derived carbene bearing increasingly sterically demanding N-substituents (R = Me 9, Et 10, i-Pr 11) and the corresponding borenium cations 12–14 were also prepared. These cations were not active as catalysts in hydrogenation, although 9–11 were shown to undergo carbene ring expansion reactions at 50 °C to give species 15–17. The IBOX-carbene precursors 18 and 19 derived from amino alcohols (S)-valinol and (S)-tert-leucinol (R = i-Pr, t-Bu) were used to prepare borane adducts 20–23. Reaction of the carbenes 1,3-dimethylimidazol-2-ylidene (IMe), 1,3-di-iso-propylimidazol-2-ylidene (IPr) 1-benzyl-3-methylimidazol-2-ylidene (IBnMe), 1-methyl-3-phenylimidazol-2-ylidene (IPhMe) and 1-tert-butyl-3-methylimidazol-2-ylidene (ItBuMe) with diisopinocampheylborane (Ipc2BH) gave chiral adducts: (IMe)(Ipc2BH) 24, (IPr)(Ipc2BH) 25, (IBnMe)(Ipc2BH) 26, (IPhMe)(Ipc2BH) 27, and (ItBuMe)(Ipc2BH) 28. Triazolylidene-type adducts including the (10)-phenyl-9-borabicyclo [3.3.2]decane adduct of 1,3,4-triphenyl-1H-1,2,3-triazolium, rac-29 and the 9-BBN derivative of (S)-2-amino-2′-methoxy-1,1′-binaphthalene-1,2,3-triazolium 34a/b were also prepared. In catalytic studies of these systems, while several species were competent catalysts for imine reduction, in general, low enantioselectivities, ranging from 1–20% ee, were obtained. The implications for chiral borenium cation catalyst design are considered

Phelan-McDermid syndrome: a review of the literature and practice parameters for medical assessment and monitoring

The purpose of this study is to contribute to a deeper understanding about how placement discontinuities of children in foster care affect their learning. The aim is to find out more about their learning and what role school plays in their life. A life-world perspective is used and theories mainly developed by Alfred Schütz (2002) build the theoretical framework. The empirical research is mainly based on narratives of a pair of twins at 19 years of age, who agreed to share their life stories and experiences of their time in school. Meetings were arranged separately with Alex, the boy, and Helena, the girl, both eager to participate. They felt that their stories could contribute to knowledge. The stories show that placement discontinuities in their early childhood made memories and their perspective of time blurry. They both suffered severe neglect in two of their foster care placements. School offered them a safe place throughout their adolescent years. However, despite this, they are critical to the teachers who saw that they suffered neglect at home but never acted upon that knowledge. Hence their first-hand experiences suggest that teachers, considered important in earlier research studies, are not as important as friend made or the daily routines that provide certain security in an otherwise uncertain life. The social services didn’t listen or support them. Alex and Helena felt that they had to take care of themselves. Their stories show that both of them are goal-oriented and that they highly value a good education. This is evident since they have always taken responsibility to complete set homework and to make school a functional place where they have also learned to know themselves. Furthermore, it is obvious that the twins have played a tremendous role for each other when their life-world time after time has changed. Alex and Helena’s stories and experiences can give the social services a deeper understanding of what lies behind the statistics. A teacher, who listens, shows support and has ambitious expectations regarding the children’s academic performance, has been confirmed in previous research to be of significant importance. In addition, the study shows that teachers should learn more about children in foster care. A life-world perspective and life-world theories can contribute to an alternative point of view regarding learning in life-world discontinuities. Learning can be reflected on by using Schütz theory about “strangers” as a way of understanding learning in a wider range, especially when there are discontinues in the life-world. The reflections made in this study point out the possibility that schools, as organizations, seem to have independent cultures that can be transferred between one another. In fact there seems to be certain variables that are the same for schools in general and hence it is of significant value to recognize school as a regional life-world. The expectations of how you act as a student and among friends are important for the sense of belonging. It is possible that Alex and Helena succeeded in school partly because some of the things they learned about the first school could be transferred to their new school. The study contributes with two new concepts; “livsvärldsbrott”- life-world-disruption and “livsvärldsbevarande”- life-world-preservation

Influence of cyclin type and dose on mitotic entry and progression in the early Drosophila embryo

Cyclins are key cell cycle regulators, yet few analyses test their role in timing the events that they regulate. We used RNA interference and real-time visualization in embryos to define the events regulated by each of the three mitotic cyclins of Drosophila melanogaster, CycA, CycB, and CycB3. Each individual and pairwise knockdown results in distinct mitotic phenotypes. For example, mitosis without metaphase occurs upon knockdown of CycA and CycB. To separate the role of cyclin levels from the influences of cyclin type, we knocked down two cyclins and reduced the gene dose of the one remaining cyclin. This reduction did not prolong interphase but instead interrupted mitotic progression. Mitotic prophase chromosomes formed, centrosomes divided, and nuclei exited mitosis without executing later events. This prompt but curtailed mitosis shows that accumulation of cyclin function does not directly time mitotic entry in these early embryonic cycles and that cyclin function can be sufficient for some mitotic events although inadequate for others

Author Correction: A consensus-based transparency checklist.

An amendment to this paper has been published and can be accessed via a link at the top of the paper

Molecular characterization and clinical outcomes of pancreatic neuroendocrine tumors (pNENs) harboring PAK4-NAMPT alterations

Background: The mTOR inhibitor, Everolimus (EVE), is FDA-approved for the treatment of advanced PNENs on the basis of delay of progression. The RADIANT-3 trial showed an increase in PFS from 4.6 to 11 months compared to placebo with an ORR of only 5%. Prior studies suggest that targeting the aberrant expression of mTOR regulators p21 activated kinase 4 (PAK4) and nicotinamide adenine dinucleotide biosynthesis enzyme nicotinamide phosphoribosyltransferase (NAMPT) in PNENs sensitizes these tumors to EVE. To further qualify these observations, we queried a large real-world dataset of PNENs, characterizing the molecular and immune landscapes, as well as the clinical outcomes associated with aberrant PAK4 and NAMPT expression. Methods: 294 cases of PNENs were analyzed using Next Generation Sequencing (NextSeq) and Whole Exome and Whole Transcriptome Sequencing (NovaSeq) at Caris Life Sciences (Phoenix, AZ). For our analyses, we stratified our study cohort into four groups based on the median expression of PAK4 and NAMPT: PAK4-low/NAMPT-low, PAK4-low/ NAMPT-high, PAK4-high/NAMPT-low and PAK4-high/NAMPT-high. Significance was determined using chi-square, Fisher-Exact or Mann-Whitney U, and p-values were adjusted for multiple comparisons (q , 0.05). Results: High prevalence of mutations in PTEN (10.71% vs 1.18%; p \u3c 0.05, q \u3e 0.05), a tumor suppressor of the mTOR pathway and high expression of genes activated in response to mTOR activation such as SLC2A1 (3.07-fold), PFKP (3.32-fold), SCD (2.70-fold), MVK (2.92-fold) and G6PD (2.58-fold) were observed in PAK4-high/NAMPT-high compared to the PAK4-low/NAMPTlow tumors (all q , 0.05). A congruent enrichment of PI3K/AKT/mTOR and glycolysis pathways by single-sample gene set enrichment analysis was observed in these tumors (all q , 0.05). When querying the immune landscape, we observed enrichment in inflammatory response, IL6/JAK/STAT3, IL2/STAT5 signaling pathways and immune checkpoint genes such as PDCD1 (5.14-fold), CD274 (2.84-fold), PDCD1LG2 (2.44-fold), CD80 (3.00-fold), CD86 (2.82-fold), IDO1 (1.92-fold), LAG3 (3.09-fold), HAVCR2 (2.66-fold) and CTLA4 (4.49-fold) in the PAK4-high/NAMPT-high tumors (all q,0.05). Immune cell infiltration estimates revealed an increase in Neutrophils, NK cells and Tregs in the PAK4-high/NAMPT-high tumors (p \u3c 0.05, q \u3e 0.05). Conclusions: Our study demonstrates that PAK4-high/NAMPT-high PNENs are associated with distinct molecular and immune profiles. While the dual blockade of PAK4 and NAMPT has been reported to enhance the efficacy of EVE in PNENs, whether such a blockade would enhance the efficacy of immunotherapeutics warrants further investigation

A randomized, placebo-controlled trial of cenicriviroc for treatment of nonalcoholic steatohepatitis with fibrosis

The aim of this study was to evaluate cenicriviroc (CVC), a dual antagonist of C-C chemokine receptor types 2 and 5, for treatment of nonalcoholic steatohepatitis (NASH) with liver fibrosis. A randomized, double-blind, multinational phase 2b study enrolled subjects with NASH, a nonalcoholic fatty liver disease activity score [NAS] ≥4, and liver fibrosis (stages 1–3, NASH Clinical Research Network) at 81 clinical sites. Subjects (N = 289) were randomly assigned CVC 150 mg or placebo. Primary outcome was ≥2-point improvement in NAS and no worsening of fibrosis at year 1. Key secondary outcomes were: resolution of steatohepatitis and no worsening of fibrosis; improvement in fibrosis by ≥1 stage and no worsening of steatohepatitis. Biomarkers of inflammation and adverse events were assessed. Full study recruitment was achieved. The primary end point of NAS improvement in the intent-to-treat population and resolution of steatohepatitis was achieved in a similar proportion of subjects on CVC (N = 145) and placebo (N = 144) (16% vs 19%, P = 0.52 and 8% vs 6%, P = 0.49, respectively). However, the fibrosis end point was met in significantly more subjects on CVC than placebo (20% vs 10%; P = 0.02). Treatment benefits were greater in those with higher disease activity and fibrosis stage at baseline. Biomarkers of systemic inflammation were reduced with CVC. Safety and tolerability of CVC were comparable to placebo. Conclusions: After 1 year of CVC treatment, twice as many subjects achieved improvement in fibrosis and no worsening of steatohepatitis compared with placebo. Given the urgent need to develop antifibrotic therapies in NASH, these findings warrant phase 3 evaluation