Practical High-Throughput, Non-Adaptive and Noise-Robust SARS-CoV-2 Testing

We propose a compressed sensing-based testing approach with a practical measurement design and a tuning-free and noise-robust algorithm for detecting infected persons. Compressed sensing results can be used to provably detect a small number of infected persons among a possibly large number of people. There are several advantages of this method compared to classical group testing. Firstly, it is non-adaptive and thus possibly faster to perform than adaptive methods which is crucial in exponentially growing pandemic phases. Secondly, due to nonnegativity of measurements and an appropriate noise model, the compressed sensing problem can be solved with the non-negative least absolute deviation regression (NNLAD) algorithm. This convex tuning-free program requires the same number of tests as current state of the art group testing methods. Empirically it performs significantly better than theoretically guaranteed, and thus the high-throughput, reducing the number of tests to a fraction compared to other methods. Further, numerical evidence suggests that our method can correct sparsely occurring errors.Comment: 8 Pages, 1 Figur

Verbesserung der Druckzeitabschätzung im 3D-Druck

Druckzeitabschätzungen im FDM 3D-Druck liegen oft weit über oder unter der tatsächlich benötigten Zeit. Eine häufig implementierte Methode, die Summe aus der berechneten Dauer einzelner Bewegungen zu bilden, bildet die physikalischen Gegebenheiten und die Auswirkungen softwareseitiger Optimierungen nur unzureichend ab. In dieser Arbeit werden mögliche Ursachen dieser Differenzen beschrieben. Außerdem wird ein im Verlauf dieser Arbeit entwickelter Ansatz zur Druckzeitabschätzung vorgestellt. Dabei werden Informationen aus bereits erfolgten Drucken verwendet, um eine Relation von inhärent in G-Code enthaltenen Eigenschaften zur dann bekannten Druckzeit zu finden, und daraus eine Berechnungsvorschrift zu abzuleiten, die als Repräsentation einer Regressions-Hyperebene dargestellt werden kann. Anschließend wird der Ansatz mit Daten von 21 verschiedenen, physikalisch gedruckten Testmodellen überprüft

Self-assembly and two-dimensional spontaneous resolution of cyano-functionalized [7]helicenes on Cu111

Birds of a feather flock together: STM and DFT studies provide the first example of spontaneous chiral resolution of a helicene on a surface. Racemic 6,13-dicyano[7]helicene forms fully segregated domains of pure enantiomers (2D conglomerate) on Cu(111). The propensity of the system to optimize intermolecular CN⋅⋅⋅HC(Ar) hydrogen bonding and CN⋅⋅⋅CN dipolar interactions translates into chiral recognition with preferential assembly of homochiral molecules

Reflectance confocal microscopy for noninvasive examination of nonmelanocytic tumors and virus‐associated skin lesions in organ transplant recipients

Background: Drug-induced immunosuppression is necessary to prevent rejection of the foreign organ in transplanted patients, but neoplastic and virus-associated skin diseases are frequent complications. Reflectance confocal microscopy (RCM) recently emerged as a promising tool for the early diagnosis of skin lesions. Materials and methods: A total of 61 skin lesions, among them 20 basal cell carcinomas, six Bowen's diseases, 23 actinic keratoses, and 12 verrucae, were analyzed. All lesions were clinically evaluated followed by RCM evaluation by two independent dermatologists and histological examination. Results: For the diagnosis of basal cell carcinoma, a sensitivity of 100% by both investigators (INV I + II) and a specificity of 100% by INV I and 80% by INV II were achieved. The sensitivity average rate for RCM features reached by both investigators ranged between 60% and 100%, and the specificity between 55% and 90%. For the diagnosis of actinic keratosis, a concordant sensitivity of 94.4% and a specificity of 80% (INV I) and 60% (INV II) were detected. The sensitivity average rate of specific RCM criteria ranged between 72.3% and 97.2%, whereas specificity ranged between 20% and 90%. Regarding verrucae, RCM confirmed the histological diagnosis with a sensitivity of 85.7% (INV I) and 100% (INV II), while specificity was 100% and 80%, respectively. Conclusion: Reflectance confocal microscopy resulted to be a reliable tool for the noninvasive diagnosis of neoplastic and virus-associated skin changes in organ transplant recipients. Nevertheless, given the frequency and diagnostic complexity of the hyperkeratotic lesions occurring post-transplantation, larger cohorts of patients are required to confirm and consolidate these findings