238 research outputs found
Grignard synthesis of fluorinated nanoporous element organic frameworks based on the heteroatoms P, B, Si, Sn and Ge
We present the synthesis and characterization of fluorinated polymers based on P, B, Si, Sn and Ge as heteroatoms via Grignard activation. The polymers are microporous with hydrophobic surfaces. The borate-based polymer was successfully applied as solid acid catalyst in the esterification of acetic acid with ethanol.
Grignard synthesis of fluorinated nanoporous element organic frameworks based on the heteroatoms P, B, Si, Sn and Ge
Recently, porous polymers have attracted considerable attention as highly versatile materials for adsorption, separation and storage of gases, in catalysis, for optoelectronic applications and energy storage. Especially, metalâorganic frameworks (MOFs) and covalent organic frameworks (COFs) are of interest due to their high surface areas and pore volumes. In order to tune the surface polarity, porous ionic organic networks were reported. Depending on the desired properties such as porosity, polarity and functionality, these materials can be tailored for their application by varying the organic linker and connector element.
The utilization of fluorinated linkers was reported for different MOFs and a COF, showing enhanced properties in terms of stability, hydrophobicity, gas affinity and selectivity in comparison to their non-fluorinated materials. In continuation of our work on element organic frameworks (EOFs) with P, Si and Sn as connector elements, here we present the synthesis and characterization of respective fluorinated porous polymers with P, B, Si, Sn and Ge as heteroatoms. The catalytic application of the borate based polymer as solid acid catalyst was demonstrated in the esterification of acetic acid with ethanol as test reaction.
As the activation of the fluorinated biphenyl linker was not successful neither via lithiation as reported for the non-fluorinated linker nor via classical Grignard reaction, a magnesium-halogen exchange was applied. The linker 4,4âČ-dibromooctafluorbiphenyl was activated twofold with isopropylmagnesium chloride lithium chloride (turbo Grignard) and subsequent reaction with the respective element chlorides in a one-pot procedure (Scheme 1) resulted in the fluorinated polymers EF-EOF (E = P, B, Si, Sn, Ge). (Perfluorophenyl)-magnesium bromide was used for end-capping, converting remaining EâCl bonds into EâAr bonds to form fully substituted trivalent or tetravalent centers, respectively. In all cases, the resulting polymers were obtained as fluffy white powders
Invertebrate 7SK snRNAs
7SK RNA is a highly abundant noncoding RNA in mammalian cells whose function in transcriptional regulation has only recently been elucidated. Despite its highly conserved sequence throughout vertebrates, all attempts to discover 7SK RNA homologues in invertebrate species have failed so far. Here we report on a combined experimental and computational survey that succeeded in discovering 7SK RNAs in most of the major deuterostome clades and in two protostome phyla: mollusks and annelids. Despite major efforts, no candidates were found in any of the many available ecdysozoan genomes, however. The additional sequence data confirm the evolutionary conservation and hence functional importance of the previously described 3âČ and 5âČ stem-loop motifs, and provide evidence for a third, structurally well-conserved domain
Dobrava-Belgrade Hantavirus from Germany Shows Receptor Usage and Innate Immunity Induction Consistent with the Pathogenicity of the Virus in Humans
BACKGROUND: Dobrava-Belgrade virus (DOBV) is a European hantavirus causing hemorrhagic fever with renal syndrome (HFRS) in humans with fatality rates of up to 12%. DOBV-associated clinical cases typically occur also in the northern part of Germany where the virus is carried by the striped field mouse (Apodemus agrarius). However, the causative agent responsible for human illness has not been previously isolated. METHODOLOGY/PRINCIPAL FINDINGS: Here we report on characterization of a novel cell culture isolate from Germany obtained from a lung tissue of "spillover" infected yellow necked mouse (A. flavicollis) trapped near the city of Greifswald. Phylogenetic analyses demonstrated close clustering of the new strain, designated Greifswald/Aa (GRW/Aa) with the nucleotide sequence obtained from a northern German HFRS patient. The virus was effectively blocked by specific antibodies directed against ÎČ3 integrins and Decay Accelerating Factor (DAF) indicating that the virus uses same receptors as the highly pathogenic Hantaan virus (HTNV). In addition, activation of selected innate immunity markers as interferon ÎČ and λ and antiviral protein MxA after viral infection of A549 cells was investigated and showed that the virus modulates the first-line antiviral response in a similar way as HTNV. CONCLUSIONS/SIGNIFICANCE: In summary, our study reveals novel data on DOBV receptor usage and innate immunity induction in relationship to virus pathogenicity and underlines the potency of German DOBV strains to act as human pathogen
Combinations of single-top-quark production cross-section measurements and vertical bar f(LV)V(tb)vertical bar determinations at root s=7 and 8 TeV with the ATLAS and CMS experiments
This paper presents the combinations of single-top-quark production cross-section measurements by the ATLAS and CMS Collaborations, using data from LHC proton-proton collisions at = 7 and 8 TeV corresponding to integrated luminosities of 1.17 to 5.1 fb(-1) at = 7 TeV and 12.2 to 20.3 fb(-1) at = 8 TeV. These combinations are performed per centre-of-mass energy and for each production mode: t-channel, tW, and s-channel. The combined t-channel cross-sections are 67.5 +/- 5.7 pb and 87.7 +/- 5.8 pb at = 7 and 8 TeV respectively. The combined tW cross-sections are 16.3 +/- 4.1 pb and 23.1 +/- 3.6 pb at = 7 and 8 TeV respectively. For the s-channel cross-section, the combination yields 4.9 +/- 1.4 pb at = 8 TeV. The square of the magnitude of the CKM matrix element V-tb multiplied by a form factor f(LV) is determined for each production mode and centre-of-mass energy, using the ratio of the measured cross-section to its theoretical prediction. It is assumed that the top-quark-related CKM matrix elements obey the relation |V-td|, |V-ts| << |V-tb|. All the |f(LV)V(tb)|(2) determinations, extracted from individual ratios at = 7 and 8 TeV, are combined, resulting in |f(LV)V(tb)| = 1.02 +/- 0.04 (meas.) +/- 0.02 (theo.). All combined measurements are consistent with their corresponding Standard Model predictions.Peer reviewe
Global assessment of marine plastic exposure risk for oceanic birds
Plastic pollution is distributed patchily around the worldâs oceans. Likewise, marine organisms that are vulnerable to plastic ingestion or entanglement have uneven distributions. Understanding where wildlife encounters plastic is crucial for targeting research and mitigation. Oceanic seabirds, particularly petrels, frequently ingest plastic, are highly threatened, and cover vast distances during foraging and migration. However, the spatial overlap between petrels and plastics is poorly understood. Here we combine marine plastic density estimates with individual movement data for 7137 birds of 77 petrel species to estimate relative exposure risk. We identify high exposure risk areas in the Mediterranean and Black seas, and the northeast Pacific, northwest Pacific, South Atlantic and southwest Indian oceans. Plastic exposure risk varies greatly among species and populations, and between breeding and non-breeding seasons. Exposure risk is disproportionately high for Threatened species. Outside the Mediterranean and Black seas, exposure risk is highest in the high seas and Exclusive Economic Zones (EEZs) of the USA, Japan, and the UK. Birds generally had higher plastic exposure risk outside the EEZ of the country where they breed. We identify conservation and research priorities, and highlight that international collaboration is key to addressing the impacts of marine plastic on wide-ranging species
Polygenic Risk Scores for Prediction of Breast Cancer and Breast Cancer Subtypes
Stratification of women according to their risk of breast cancer based on polygenic risk scores (PRSs) could improve screening and prevention strategies. Our aim was to develop PRSs, optimized for prediction of estrogen receptor (ER)-specific disease, from the largest available genome-wide association dataset and to empirically validate the PRSs in prospective studies. The development dataset comprised 94,075 case subjects and 75,017 control subjects of European ancestry from 69 studies, divided into training and validation sets. Samples were genotyped using genome-wide arrays, and single-nucleotide polymorphisms (SNPs) were selected by stepwise regression or lasso penalized regression. The best performing PRSs were validated in an independent test set comprising 11,428 case subjects and 18,323 control subjects from 10 prospective studies and 190,040 women from UK Biobank (3,215 incident breast cancers). For the best PRSs (313 SNPs), the odds ratio for overall disease per 1 standard deviation in ten prospective studies was 1.61 (95%CI: 1.57-1.65) with area under receiver-operator curve (AUC) = 0.630 (95%CI: 0.628-0.651). The lifetime risk of overall breast cancer in the top centile of the PRSs was 32.6%. Compared with women in the middle quintile, those in the highest 1% of risk had 4.37- and 2.78-fold risks, and those in the lowest 1% of risk had 0.16- and 0.27-fold risks, of developing ER-positive and ER-negative disease, respectively. Goodness-of-fit tests indicated that this PRS was well calibrated and predicts disease risk accurately in the tails of the distribution. This PRS is a powerful and reliable predictor of breast cancer risk that may improve breast cancer prevention programs.NovartisEli Lilly and CompanyAstraZenecaAbbViePfizer UKCelgeneEisaiGenentechMerck Sharp and DohmeRocheCancer Research UKGovernment of CanadaArray BioPharmaGenome CanadaNational Institutes of HealthEuropean CommissionMinistĂšre de l'Ăconomie, de lâInnovation et des Exportations du QuĂ©becSeventh Framework ProgrammeCanadian Institutes of Health Researc
Photography-based taxonomy is inadequate, unnecessary, and potentially harmful for biological sciences
The question whether taxonomic descriptions naming new animal species without type specimen(s) deposited in collections should be accepted for publication by scientific journals and allowed by the Code has already been discussed in Zootaxa (Dubois & NemĂ©sio 2007; Donegan 2008, 2009; NemĂ©sio 2009aâb; Dubois 2009; Gentile & Snell 2009; Minelli 2009; Cianferoni & Bartolozzi 2016; Amorim et al. 2016). This question was again raised in a letter supported
by 35 signatories published in the journal Nature (Pape et al. 2016) on 15 September 2016. On 25 September 2016, the following rebuttal (strictly limited to 300 words as per the editorial rules of Nature) was submitted to Nature, which on
18 October 2016 refused to publish it. As we think this problem is a very important one for zoological taxonomy, this text is published here exactly as submitted to Nature, followed by the list of the 493 taxonomists and collection-based
researchers who signed it in the short time span from 20 September to 6 October 2016
Embracing monogenic Parkinson's disease: the MJFF Global Genetic PD Cohort
© 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.Background: As gene-targeted therapies are increasingly being developed for Parkinson's disease (PD), identifying and characterizing carriers of specific genetic pathogenic variants is imperative. Only a small fraction of the estimated number of subjects with monogenic PD worldwide are currently represented in the literature and availability of clinical data and clinical trial-ready cohorts is limited.
Objective: The objectives are to (1) establish an international cohort of affected and unaffected individuals with PD-linked variants; (2) provide harmonized and quality-controlled clinical characterization data for each included individual; and (3) further promote collaboration of researchers in the field of monogenic PD.
Methods: We conducted a worldwide, systematic online survey to collect individual-level data on individuals with PD-linked variants in SNCA, LRRK2, VPS35, PRKN, PINK1, DJ-1, as well as selected pathogenic and risk variants in GBA and corresponding demographic, clinical, and genetic data. All registered cases underwent thorough quality checks, and pathogenicity scoring of the variants and genotype-phenotype relationships were analyzed.
Results: We collected 3888 variant carriers for our analyses, reported by 92 centers (42 countries) worldwide. Of the included individuals, 3185 had a diagnosis of PD (ie, 1306 LRRK2, 115 SNCA, 23 VPS35, 429 PRKN, 75 PINK1, 13 DJ-1, and 1224 GBA) and 703 were unaffected (ie, 328 LRRK2, 32 SNCA, 3 VPS35, 1 PRKN, 1 PINK1, and 338 GBA). In total, we identified 269 different pathogenic variants; 1322 individuals in our cohort (34%) were indicated as not previously published.
Conclusions: Within the MJFF Global Genetic PD Study Group, we (1) established the largest international cohort of affected and unaffected individuals carrying PD-linked variants; (2) provide harmonized and quality-controlled clinical and genetic data for each included individual; (3) promote collaboration in the field of genetic PD with a view toward clinical and genetic stratification of patients for gene-targeted clinical trials. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.Michael J. Fox Foundation for Parkinson's Research. Grant Number: ID 15015.02. NIHR Cambridge Biomedical Research Centre. Grant Number: BRC-1215-20014info:eu-repo/semantics/publishedVersio
Developing quality indicators for physician-staffed emergency medical services: a consensus process
Infiltration of tin bronze into alumina particle beds: influence of alloy chemistry on drainage curves
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