C–H-Bond Activation and Isoprene Polymerization Studies Applying Pentamethylcyclopentadienyl-Supported Rare-Earth-Metal Bis(Tetramethylaluminate) and Dimethyl Complexes

As previously shown for lutetium and yttrium, 1,2,3,4,5-pentamethylcyclopentadienyl (C5Me5 = Cp*)-bearing rare-earth metal dimethyl half-sandwich complexes [Cp*LnMe2]3 are now also accessible for holmium, dysprosium, and terbium via tetramethylaluminato cleavage of [Cp*Ln(AlMe4)2] with diethyl ether (Ho, Dy) and tert-butyl methyl ether (TBME) (Tb). C–H-bond activation and ligand redistribution reactions are observed in case of terbium and are dominant for the next larger-sized gadolinium, as evidenced by the formation of mixed methyl/methylidene clusters [(Cp*Ln)5(CH2)(Me)8] and metallocene dimers [Cp*2Ln(AlMe4)]2 (Ln = Tb, Gd). Applying TBME as a “cleaving” reagent can result in both TBME deprotonation and ether cleavage, as shown for the formation of the 24-membered macrocycle [(Cp*Gd)2(Me)(CH2OtBu)2(AlMe4)]4 or monolanthanum complex [Cp*La(AlMe4){Me3Al(CH2)OtBu}] and monoyttrium complex [Cp*Y(AlMe4)(Me3AlOtBu)], respectively. Complexes [Cp*Ln(AlMe4)2] (Ln = Ho, Dy, Tb, Gd) and [Cp*LnMe2]3 (Ln = Ho, Dy) are applied in isoprene and 1,3-butadiene polymerization, upon activation with borates [Ph3C][B(C6F5)4] and [PhNHMe2][B(C6F5)4], as well as borane B(C6F5)3. The trans-directing effect of AlMe3 in the binary systems [Cp*Ln(AlMe4)2]/borate is revealed and further corroborated by the fabrication of high-cis-1,4 polybutadiene (97%) with “aluminum-free” [Cp*DyMe2]3/[Ph3C][B(C6F5)4]. The formation of multimetallic active species is supported by the polymerization activity of pre-isolated cluster [(Cp*Ho)3Me4(CH2)(thf)2].publishedVersio

GA4GH: International policies and standards for data sharing across genomic research and healthcare.

The Global Alliance for Genomics and Health (GA4GH) aims to accelerate biomedical advances by enabling the responsible sharing of clinical and genomic data through both harmonized data aggregation and federated approaches. The decreasing cost of genomic sequencing (along with other genome-wide molecular assays) and increasing evidence of its clinical utility will soon drive the generation of sequence data from tens of millions of humans, with increasing levels of diversity. In this perspective, we present the GA4GH strategies for addressing the major challenges of this data revolution. We describe the GA4GH organization, which is fueled by the development efforts of eight Work Streams and informed by the needs of 24 Driver Projects and other key stakeholders. We present the GA4GH suite of secure, interoperable technical standards and policy frameworks and review the current status of standards, their relevance to key domains of research and clinical care, and future plans of GA4GH. Broad international participation in building, adopting, and deploying GA4GH standards and frameworks will catalyze an unprecedented effort in data sharing that will be critical to advancing genomic medicine and ensuring that all populations can access its benefits

Food webs under changing biodiversity - Top-down control

Report on effects of changing predation pressure on benthic and pelagic specie

Workshop Methods for Troubleshooting the Performance of the After-treatment system

New legislations are constantly arising in Europe that puts stringent restrictions on the emissions coming from heavy-duty vehicles. The latest one is the Euro VI that has tough limits on both nitrogen oxides (NOx) and particulate matter (PM). To be able to cope with these tough limits, many developers of heavy-duty trucks have chosen to mount an after-treatment system after the engine containing several different catalysts. The emissions are monitored by an On-Board Diagnosis (OBD) system during operation, and if the emissions are too high a Malfunction Indicator (MI) lamp is lit and the truck needs to be serviced in a workshop. In the workshop the fault is investigated, which could be caused by several things, one of which may be a performance loss of one of the catalysts.This master thesis investigates different methods for testing the performance of two of these catalysts. The catalysts that were investigated was the Diesel Oxidation Catalyst (DOC) that oxidizes hydrocarbons (HC), carbon monoxide (CO) and nitrogen monoxide (NO), and Selective Catalytic Reduction (SCR) that uses ammonia for the reduction of nitrogen oxides (NOx). A comprehensive literature study was made to get an insight in how the current system works and to be able to develop concepts for future workshop methods. From the literature study, three concepts were developed for each catalyst. These concepts were tested out on Scania’s 13 litre 6-cylinder Euro VI engine with Scania’s Euro VI after-treatment system. The concepts are mainly consisting of three measuring principles that investigates the changes in temperature, NOx-conversion and ammonia storage. The tests resulted in that one concept per catalyst could be used to isolate and measure the performance. The performance of the DOC could be measured with the increase of temperature due to the exothermal reaction when HC is injected into the catalyst, called Measurement of HC-slip. To be able to measure the performance of the SCR, the changes in the maximum ammonia storage that the catalyst could achieve during an ammonia sweep was used, called Measurement of ammonia storage

Workshop Methods for Troubleshooting the Performance of the After-treatment system

New legislations are constantly arising in Europe that puts stringent restrictions on the emissions coming from heavy-duty vehicles. The latest one is the Euro VI that has tough limits on both nitrogen oxides (NOx) and particulate matter (PM). To be able to cope with these tough limits, many developers of heavy-duty trucks have chosen to mount an after-treatment system after the engine containing several different catalysts. The emissions are monitored by an On-Board Diagnosis (OBD) system during operation, and if the emissions are too high a Malfunction Indicator (MI) lamp is lit and the truck needs to be serviced in a workshop. In the workshop the fault is investigated, which could be caused by several things, one of which may be a performance loss of one of the catalysts.This master thesis investigates different methods for testing the performance of two of these catalysts. The catalysts that were investigated was the Diesel Oxidation Catalyst (DOC) that oxidizes hydrocarbons (HC), carbon monoxide (CO) and nitrogen monoxide (NO), and Selective Catalytic Reduction (SCR) that uses ammonia for the reduction of nitrogen oxides (NOx). A comprehensive literature study was made to get an insight in how the current system works and to be able to develop concepts for future workshop methods. From the literature study, three concepts were developed for each catalyst. These concepts were tested out on Scania’s 13 litre 6-cylinder Euro VI engine with Scania’s Euro VI after-treatment system. The concepts are mainly consisting of three measuring principles that investigates the changes in temperature, NOx-conversion and ammonia storage. The tests resulted in that one concept per catalyst could be used to isolate and measure the performance. The performance of the DOC could be measured with the increase of temperature due to the exothermal reaction when HC is injected into the catalyst, called Measurement of HC-slip. To be able to measure the performance of the SCR, the changes in the maximum ammonia storage that the catalyst could achieve during an ammonia sweep was used, called Measurement of ammonia storage

C-H-Bond activation and isoprene polymerization studies applying pentamethylcyclopentadienyl-supported rare-earth-metal Bis(tetramethylaluminate) and dimethyl complexes

As previously shown for lutetium and yttrium, 1,2,3,4,5-pentamethylcyclopentadienyl (C5Me5 = Cp*)-bearing rare-earth metal dimethyl half-sandwich complexes [Cp*LnMe2]3 are now also accessible for holmium, dysprosium, and terbium via tetramethylaluminato cleavage of [Cp*Ln(AlMe4)2] with diethyl ether (Ho, Dy) and tert-butyl methyl ether (TBME) (Tb). C–H-bond activation and ligand redistribution reactions are observed in case of terbium and are dominant for the next larger-sized gadolinium, as evidenced by the formation of mixed methyl/methylidene clusters [(Cp*Ln)5(CH2)(Me)8] and metallocene dimers [Cp*2Ln(AlMe4)]2 (Ln = Tb, Gd). Applying TBME as a “cleaving” reagent can result in both TBME deprotonation and ether cleavage, as shown for the formation of the 24-membered macrocycle [(Cp*Gd)2(Me)(CH2OtBu)2(AlMe4)]4 or monolanthanum complex [Cp*La(AlMe4){Me3Al(CH2)OtBu}] and monoyttrium complex [Cp*Y(AlMe4)(Me3AlOtBu)], respectively. Complexes [Cp*Ln(AlMe4)2] (Ln = Ho, Dy, Tb, Gd) and [Cp*LnMe2]3 (Ln = Ho, Dy) are applied in isoprene and 1,3-butadiene polymerization, upon activation with borates [Ph3C][B(C6F5)4] and [PhNHMe2][B(C6F5)4], as well as borane B(C6F5)3. The trans-directing effect of AlMe3 in the binary systems [Cp*Ln(AlMe4)2]/borate is revealed and further corroborated by the fabrication of high-cis-1,4 polybutadiene (97%) with “aluminum-free” [Cp*DyMe2]3/[Ph3C][B(C6F5)4]. The formation of multimetallic active species is supported by the polymerization activity of pre-isolated cluster [(Cp*Ho)3Me4(CH2)(thf)2]