727 research outputs found
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Chirale polyzyklische aromatische Kohlenwasserstoffe mit Affensattel-Topologie [Data]
No full textIn this thesis, the first chiral polycyclic aromatic hydrocarbon (PAH) with a monkey saddle topology is presented. Starting from a truxene building block that is readily preparatively accessible, the monkey saddle PAH could easily be obtained in three steps. By using additional functionalized precursors, a series of twelve derivatives has been obtained and characterized. Solid-state structures confirmed the three-dimensional shape of the PAHs unambiguously, which is induced by the five-, six- and eight-membered rings. This makes the PAH a section of a Mackay-type crystal. Due to the curvature, the target compounds exhibit triple axial chirality. Separation of the enantiomers was possible and characterization of these via CD spectroscopy and the investigation of racemization revealed half-lives ranging from a few milliseconds to several days. In addition, first attempts to synthesize Mackay-like cage compounds have been conducted and provided important insights for future projects. A deeper insight into the properties of the curved PAHs was achieved by the isosteric exchange of three CH groups with nitrogen. Its effect could be studied in detail and led to a stabilization of the enantiomers towards a half-life of two months. Furthermore, a rearrangement was developed that lead to a chiral molecular basket whose enantiomers do not longer racemize at room temperature. The experimental results were supported and extended by a large number of quantumchemical calculations.
A second truxene precursor formed the basis on which the preparation of a system with three azulene units succeeded. Synthetic difficulties on the way to the target compound could be circumvented and thus a keto-functionalized PAH has been obtained, which forms two separable diastereomers. The azulene PAH represents a model of a graphene defect due to the five- and seven-membered rings and was studied in terms of its photophysical and electrochemical properties as well as compared with isomeric compounds. Confirmation of the structures of all three target compounds by X-ray structural analysis was also successful. First experiments on post-functionalization were performed so that future projects can build on them
Persistent Ambipolar Heptacenes and Their Redox Species [Data]
No full textResearch Data associated with the related publication.
Sixfold TIPS-ethynylation combined with fourfold bromination of the armchair edges furnishes a long-lived, soluble heptacene; π-extension via Stille coupling accesses a persistent tetrabenzononacene. Both types of acenes were stabilized best by double TIPS-ethynylation on every other benzene ring. Tetrabromoheptacene is an ambipolar transistor material (up to 0.036 cm2/Vs n channel), which was corroborated by generation of its monoanion and monocation
Soluble Congeners of Prior Insoluble Shape‐Persistent Imine Cages [Data]
No full textOne of the most applied reaction types to synthesize shape‐persistent organic cage compounds is the imine condensation reaction and it is assumed that the formed cages are thermodynamically controlled products due to the reversibility of the imine condensation. However, most of the synthesized imine cages reported are formed as precipitate from the reaction mixture and therefore rather may be kinetically controlled products. There are even examples in literature, where resulting cages are not soluble at all in common organic solvents to characterize or study their formation by NMR spectroscopy in solution. Here, a triptycene triamine containing three solubilizing n‐hexyloxy chains has been used to synthesize soluble congeners of prior insoluble cages. This allowed us to study the formation as well the reversibility of cage formation in solution by investigating exchange of building blocks between the cages and deuterated derivatives thereof
Performance of Covid-19 antigen rapid diagnostic tests for self-testing compared with antigen testing by professionals and molecular tests: A systematic review and meta-analysis [Research Data]
No full textObjectives
Self-testing is an effective tool to bridge the testing gap for a number of infectious diseas-es; however, its performance using SARS-CoV-2 antigen-detection rapid diagnostic tests (Ag-RDTs) has not been systematically reviewed. We evaluated the accuracy of COVID-19 self-testing and/or self-sampling using Ag-RDTs to inform WHO guideline development.
Methods:
We searched multiple databases for articles evaluating the accuracy of COVID-19 self-testing or self-sampling through November 19th, 2021. Cohen’s kappa was estimated to as-sess concordance between self-testing/self-sampling and solely professional-use Ag-RDT results. Meta-analysis was performed to obtain pooled performance estimates compared to molecular testing. The QUADAS-2 and GRADE tools were used to evaluate quality and cer-tainty of evidence.
Results:
Of 12,946 publications, 19 were eligible; two reported on self-testing, while 17 studies as-sessed self-sampling only. Risk of bias was low (28.1%). Overall concordance with profes-sional-use Ag-RDTs (n=5) was high (kappa 0.92 [95% confidence interval (CI) 0.89 to 0.95]). Overall pooled sensitivity of Ag-RDT testing using self-testing/self-sampling was 72.0% (95% CI 62.4 to 80.0).
Conclusion:
COVID-19 self-testing/self-sampling exhibits reasonable performance and high concordance with professional-use Ag-RDTs. This suggest that self-sampling, at a minimum, can be offered as part of COVID-19 testing strategies, despite high heterogeneity among studies and the paucity of data
Policy mixes for biodiversity: A diffusion analysis of state-level citizens’ initiatives in Germany [Dataset]
No full textThe dataset contains data used to produce Figure 1 in the article
Social and Cognitive Congruence [Data]
No full textThis dataset contains the R-Script of our Evaluation and the dataset on which our results are based
Multimodal ground truth datasets for abdominal medical image registration [data]
No full textSparsity of annotated data is a major limitation in medical image processing tasks such as registration. Registered multimodal image data are essential for the diagnosis of medical conditions and the success of interventional medical procedures. To overcome the shortage of data, we present a method that allows the generation of annotated multimodal 4D datasets.
We use a CycleGAN network architecture to generate multimodal synthetic data from the 4D extended cardiac–torso (XCAT) phantom and real patient data. Organ masks are provided by the XCAT phantom; therefore, the generated dataset can serve as ground truth for image segmentation and registration.
Compared to real patient data, the synthetic data showed good agreement regarding the image voxel intensity distribution and the noise characteristics. The generated T1-weighted magnetic resonance imaging, computed tomography (CT), and cone beam CT images are inherently co-registered
NLP in Diagnostic Texts from Nephropathology [Research Data]
No full textThis data set contains all annotated topic word tables from the work "NLP in Diagnostic Texts from Nephropathology", as well as all pre-processed and tf-idf-vectorized text files. The raw texts (i.e., descriptive and diagnostic sections) are explicitly not made available, since it cannot be ruled out here that it is possible to infer the patient or the person making the report. This is in accordance with our local ethics committee.
Please note: This data set is not yet complete and will be completed soon.
Please refer to chapter 3.1.2 of our paper to learn how to interpret the annotated topic word tables.
The associated gitlab project
http://gitlab.medma.uni-heidelberg.de/mlegnar/nlp-in-diagnostic-texts-from-nephropathology contains some examples of how the .pkl files can be opened and used with python
Desymmetrization Strategy to Achieve Triptycene-Based 3,6-Dimethoxytriphenylenes via Oxidative Cyclodehydrogenation [Data]
No full textTo achieve a highly symmetric triptycene based hexamethoxytriphenylene in high yield of 97 %, a less symmetric triptycene (C3v) is necessary as precursor for cyclodehydrogenative Scholl-type oxidation, by taking into account the regioselectivity of the C-C bond formation controlled by attached methoxy groups. In addition, Scholl-type oxidations and photochemical reactions are compared
User perspectives and preferences on a novel TB LAM diagnostic (Fujifilm SILVAMP TB LAM) – a qualitative study in Malawi and Zambia [data]
No full textThis data set supports the findings of the FujiLAM qualitative study published in PLOS Global Public Health (Titel:"User perspectives and preferences on a novel TB LAM diagnostic (Fujifilm SILVAMP TB LAM) – a qualitative study in Malawi and Zambia").
The repository contains our de-identified data extracts of our study transcripts after the initial coding step. The analysis memos describe the early phase of analysis after completing the coding process and creating data extracts