לוח שנה משולב

After almost 100 years of research inorganic layered (2D) materials, like MoS2, are currently used as catalysts, lubricants, and perhaps most importantly in rechargeable Li- ion batteries. After a short briefing on the history of 2D materials research,1 the concepts which lead to the first synthesis of hollow-cage nanostructures, including nanotubes (INT) and fullerene-like (IF) nanoparticles from 2D compounds, will be presented. The progress with the high-temperature synthesis and characterization of new inorganic nanotubes (INT) and fullerene-like (IF) nanoparticles (NP) will be presented. In particular, the synthesis and structure of nanotubes from the ternary “misfit” layered compounds (MLC), like LnS-TaS2 (Ln= La, Ce, Gd, Ho, Er), CaCoO-CoO2 and numerous other MLC were elucidated. More recently nanotubes (and nanoscrolls) from quaternary MLC were reported.
Major progress has been achieved in elucidating the structure of INT and IF using advanced microscopy techniques, like aberration corrected TEM and related techniques. Mechanical, electrical and optical measurements of individual WS2 nanotubes reveal their unique quasi-1D characteristics. This analysis demonstrate their different behavior compared to the bulk phase. Applications of the IF/INT as superior solid lubricants and for reinforcement of variety of polymers and light metal alloys was demonstrated. Few recent studies indicate that this brand of nanoparticles is less toxic than most nanoparticles. With expanding product lines, manufacturing and sales, these nanomaterials are gradually becoming an industrial commodity.
1. L. Panchakarla, B. Visic and R. Tenne, “Perspective”, J. Am. Chem. Soc. 2017, 139, 12865-12878.

Cell penetrating peptides have a unique potential for targeted drug delivery, therefore, mechanistic understanding of their membrane action has been sought since their discovery over 20 years ago. While ATP-driven endocytosis is known to play a major role in their internalization, there has been also ample evidence for the importance of passive translocation for which the direct mechanism, where the peptide is thought to directly pass through the membrane via a temporary pore, has been widely advocated. In this talk, I will question this view and demonstrate that arginine-rich cell penetrating peptides can instead enter vesicles and cells by inducing multilamellarity and fusion, analogously to the action of calcium ions. The molecular picture of this penetration mode, which differs qualitatively from the previously proposed direct mechanism, is provided by molecular dynamics simulations. In addition, the kinetics of vesicle agglomeration and fusion by nonaarginine, nonalysine, and calcium ions are documented in real time by fluorescence techniques and the induction of multilamellar phases in vesicles and cells is revealed both via electron microscopy and fluorescence spectroscopy. We thus show that the newly identified passive cell penetration mechanism is analoguous to vesicle fusion induced by calcium ions, demonstrating that the two processes are of a common mechanistic origin.

Precise protein folding by the endoplasmic reticulum (ER) supports homeostasis, while cumulative protein misfolding causes ER stress and promotes disease. The kinases PERK and IRE1 help orchestrate the unfolded protein response (UPR) to alleviate ER stress; however, if stress persists, the UPR activates apoptosis to eliminate the damaged cell. We have previously shown that PERK drives cell death via transcriptional up-regulation of the pro-apoptotic death receptor DR5; we further showed that IRE1—which harbors both kinase and RNase modules—blocks apoptosis through regulated IRE1-dependent mRNA decay (RIDD) of DR5 (Lu et al, Science 2014). Recently, we turned to investigate the paradoxical observation that under irresolvable ER stress PERK activity persists, while IRE1 function attenuates. We discovered that PERK governs the attenuation of IRE1, through a phosphatase called RNA polymerase II-associated protein 2 (RPAP2). RPAP2 reverses IRE1 phosphorylation, inhibiting IRE1 RNase activation. This disrupts IRE1-dependent generation of the cytoprotective transcription factor XBP1s and dampens ER-associated degradation of misfolded proteins. Furthermore, it inhibits RIDD, thereby licensing DR5-mediated caspase activation and apoptotic cell death. Thus, under excessive ER stress, PERK attenuates IRE1 via RPAP2 to abort failed adaptation and trigger an apoptotic cell fate.

Joseph Süss Oppenheimer—"Jew Süss"—is one of the most iconic figures in the history of an-ti-Semitism. Originally from Heidelberg, in 1733 Oppenheimer became the "court Jew" of the duke of the small German state of Württemberg. When the duke died unexpectedly a few years later, the Württemberg authorities arrested Oppenheimer, put him on trial, and con-demned him to death for unspecified "misdeeds." On February 4, 1738, Oppenheimer was hanged in front of a large crowd just outside Stuttgart. It was one of the most sensational exe-cutions of the entire eighteenth century.

This lecture by Prof. Yair Mintzker (Princeton University) is based on his new book, “The Many Deaths of Jew Süss: The Notorious Trial and Execution of an Eighteen Century Court Jew” (Princeton UP, 2017). It will concentrate on the tension between the historical figure of “Jew Süss” as reflected in eighteenth-century sources on the one hand, and, on the other hand, the widespread and often cynical use of this figure in later works of fiction, chief among them the vicious Nazi propaganda movie "Jew Süss,” which was made in 1940 at the behest of Joseph Goebbels.

The atmospheric circulation determines the structure of Earth’s climate. Changes in the circulation, such as meridional shifts in the circulation patterns can lead to dramatic changes in the local climate. Increased greenhouse gas emission is expected to change the vertical and meridional temperature profile and affect the atmospheric circulation. Climate models predict that greenhouse gas-induced climate change would cause a warming of the troposphere and cooling of the stratosphere, as well as a poleward and upward shift of the midlatitude jet stream and storm tracks - the major components of the extratropical circulation. The response of the atmospheric circulation to climate change is difficult to explain, due to nonlinear dynamical feedbacks within the system. Previous studies have attempted to explain the poleward shift of the jet stream in response to climate change based on different dynamical mechanisms. Here we propose an alternative approach of connecting the energy and momentum flux in order to explain the jet shift based on energy balance considerations.