Nonlinear terahertz control of the lead halide perovskite lattice

Lead halide perovskites (LHPs) have emerged as an excellent class of semiconductors for next-generation solar cells and optoelectronic devices. Tailoring physical properties by fine-tuning the lattice structures has been explored in these materials by chemical composition or morphology. Nevertheless, its dynamic counterpart, phonon-driven ultrafast material control, as contemporarily harnessed for oxide perovskites, has not yet been established. Here, we use intense THz electric fields to obtain direct lattice control via nonlinear excitation of coherent octahedral twist modes in hybrid CH3NH3PbBr3 and all-inorganic CsPbBr3 perovskites. These Raman-active phonons at 0.9 to 1.3 THz are found to govern the ultrafast THz-induced Kerr effect in the low-temperature orthorhombic phase and thus dominate the phonon-modulated polarizability with potential implications for dynamic charge carrier screening beyond the Fröhlich polaron. Our work opens the door to selective control of LHP’s vibrational degrees of freedom governing phase transitions and dynamic disorder

Local control of globally competing patterns in coupled Swift--Hohenberg equations

We present analytical and numerical investigations of two anti-symmetrically coupled 1D Swift--Hohenberg equations (SHEs) with cubic nonlinearities. The SHE provides a generic formulation for pattern formation at a characteristic length scale. A linear stability analysis of the homogeneous state reveals a wave instability in addition to the usual Turing instability of uncoupled SHEs. We performed weakly nonlinear analysis in the vicinity of the codimension-two point of the Turing-wave instability, resulting in a set of coupled amplitude equations for the Turing pattern as well as left and right traveling waves. In particular, these complex Ginzburg--Landau-type equations predict two major things: there exists a parameter regime where multiple different patterns are stable with respect to each other; and that the amplitudes of different patterns interact by local mutual suppression. In consequence, different patterns can coexist in distinct spatial regions, separated by localized interfaces. We identified specific mechanisms for controlling the position of these interfaces, which distinguish what kinds of patterns the interface connects and thus allow for global pattern selection. Extensive simulations of the original SHEs confirm our results

A 1100-year multi-proxy palaeoenvironmental record from Lake Höglwörth, Bavaria, Germany

Anthropogenic activities have exerted strong influence on ecosystems worldwide, particularly since 1950 CE. The local impact of past human activities often started much earlier and deserves detailed study. Here, we present an environmental record from a 278 cm long sedimentary core from Lake Höglwörth (Bavaria, Germany). Sedimentological and geochemical parameters indicate that the organic-rich bottom sediments of the record consist of peat that formed prior to 870+140-160 CE, when lake sediments started to accumulate. After 870+140-160 CE, distinct shifts in lithology, elemental composition, and the biological record are visible and are interpreted to result from the construction of a monastery on the lake peninsula in 1125 CE and/or the damming of the lake. From 1120±120 to 1240+110-120 CE, the lake environment was relatively stable. This period was followed by enhanced deforestation that led to a more open landscape and soil erosion, visible in increased allochthonous input from 1240+110-120 to 1380+90-110 CE. This was accompanied by high aquatic productivity and bottom or interstitial water anoxia from 1310+100-120 to 1470+90-100 CE, possibly triggered by increased nutrient availability. Enhanced allochthonous input and a substantial shift in the aquatic community can be assigned to the construction of a flour mill and related rerouting of a small creek in 1701 CE. High aquatic productivity and bottom or interstitial water anoxia after 1960±10 CE correspond to recent eutrophication resulting from accelerated local anthropogenic activities. The sedimentary record from Lake Höglwörth exemplarily demonstrates that anthropogenic activities have had substantial environmental impacts on aquatic environments during the past millennium

Developing Recombinant Antibodies by Phage Display Against Infectious Diseases and Toxins for Diagnostics and Therapy

Antibodies are essential molecules for diagnosis and treatment of diseases caused by pathogens and their toxins. Antibodies were integrated in our medical repertoire against infectious diseases more than hundred years ago by using animal sera to treat tetanus and diphtheria. In these days, most developed therapeutic antibodies target cancer or autoimmune diseases. The COVID-19 pandemic was a reminder about the importance of antibodies for therapy against infectious diseases. While monoclonal antibodies could be generated by hybridoma technology since the 70ies of the former century, nowadays antibody phage display, among other display technologies, is robustly established to discover new human monoclonal antibodies. Phage display is an in vitro technology which confers the potential for generating antibodies from universal libraries against any conceivable molecule of sufficient size and omits the limitations of the immune systems. If convalescent patients or immunized/infected animals are available, it is possible to construct immune phage display libraries to select in vivo affinity-matured antibodies. A further advantage is the availability of the DNA sequence encoding the phage displayed antibody fragment, which is packaged in the phage particles. Therefore, the selected antibody fragments can be rapidly further engineered in any needed antibody format according to the requirements of the final application. In this review, we present an overview of phage display derived recombinant antibodies against bacterial, viral and eukaryotic pathogens, as well as microbial toxins, intended for diagnostic and therapeutic applications

Early mobilisation in critically ill COVID-19 patients: a subanalysis of the ESICM-initiated UNITE-COVID observational study

Background Early mobilisation (EM) is an intervention that may improve the outcome of critically ill patients. There is limited data on EM in COVID-19 patients and its use during the first pandemic wave. Methods This is a pre-planned subanalysis of the ESICM UNITE-COVID, an international multicenter observational study involving critically ill COVID-19 patients in the ICU between February 15th and May 15th, 2020. We analysed variables associated with the initiation of EM (within 72 h of ICU admission) and explored the impact of EM on mortality, ICU and hospital length of stay, as well as discharge location. Statistical analyses were done using (generalised) linear mixed-effect models and ANOVAs. Results Mobilisation data from 4190 patients from 280 ICUs in 45 countries were analysed. 1114 (26.6%) of these patients received mobilisation within 72 h after ICU admission; 3076 (73.4%) did not. In our analysis of factors associated with EM, mechanical ventilation at admission (OR 0.29; 95% CI 0.25, 0.35; p = 0.001), higher age (OR 0.99; 95% CI 0.98, 1.00; p ≤ 0.001), pre-existing asthma (OR 0.84; 95% CI 0.73, 0.98; p = 0.028), and pre-existing kidney disease (OR 0.84; 95% CI 0.71, 0.99; p = 0.036) were negatively associated with the initiation of EM. EM was associated with a higher chance of being discharged home (OR 1.31; 95% CI 1.08, 1.58; p = 0.007) but was not associated with length of stay in ICU (adj. difference 0.91 days; 95% CI − 0.47, 1.37, p = 0.34) and hospital (adj. difference 1.4 days; 95% CI − 0.62, 2.35, p = 0.24) or mortality (OR 0.88; 95% CI 0.7, 1.09, p = 0.24) when adjusted for covariates. Conclusions Our findings demonstrate that a quarter of COVID-19 patients received EM. There was no association found between EM in COVID-19 patients' ICU and hospital length of stay or mortality. However, EM in COVID-19 patients was associated with increased odds of being discharged home rather than to a care facility. Trial registration ClinicalTrials.gov: NCT04836065 (retrospectively registered April 8th 2021)

Fighting the real AI Danger: How to Design Virtuous AI for Virtuous Decision-making

Artificial Intelligence, i.e., complex algorithms that learn to perform functions associated with human minds, such as perceiving, decision-making, and demonstrating creativity. Indeed, more often than not, AI is trained on biased datasets, that is, this data is disproportionately weighted in favor of or against certain individuals or groups of individuals. The roots for such biases are very diverse, sometimes they are technical in nature, but often they originate in the minds of people, making it difficult to identify these biases, e.g. if such a disproportionate weighting is perceived as ‘normal’ by many, while it is still devastating to few. We argue that the use of virtue ethics in AI can help to mitigate the consequences of biases and to help identify such biases. In particular, we aim to assess in multiple online and field experiments how the virtue ‘transparency’ affects an individual’s decision-making and perceptions regarding the AI

Local control of globally competing patterns in coupled Swift-Hohenberg equations

We present analytical and numerical investigations of two anti-symmetrically coupled 1D Swift-Hohenberg equations (SHEs) with cubic nonlinearities. The SHE provides a generic formulation for pattern formation at a characteristic length scale. A linear stability analysis of the homogeneous state reveals a wave instability in addition to the usual Turing instability of uncoupled SHEs. We performed weakly nonlinear analysis in the vicinity of the codimension-two point of the Turingwave instability, resulting in a set of coupled amplitude equations for the Turing pattern as well as left and right traveling waves. In particular, these complex Ginzburg-Landau-type equations predict two major things: there exists a parameter regime where multiple different patterns are stable with respect to each other; and that the amplitudes of different patterns interact by local mutual suppression. In consequence, different patterns can coexist in distinct spatial regions, separated by localized interfaces. We identified specific mechanisms for controlling the position of these interfaces, which distinguish what kinds of patterns the interface connects and thus allow for global pattern selection. Extensive simulations of the original SHEs confirm our results

Acetabular Revision With Intramedullary and Extramedullary Iliac Fixation for Pelvic Discontinuity

Background: Parallel to the increase in revision hip procedures surgeons face more and more complex anatomical challenges with pelvic discontinuity (PD) being one of the worst-case scenarios. Here we report on our clinical results using an asymmetric acetabular component for the treatment of PD. The implant is armed in a monoblock fashion with an extramedullary iliac flange and provides the possibility to augment it with an intramedullary iliac press-fit stem. Methods: In a single-center retrospective cohort study we analyzed prospectively collected data of 49 patients (35 female, 14 male) suffering from unilateral periprosthetic PD treated with an asymmetric acetabular component between 2009 and 2017. The mean follow-up was 71 months (21-114). Complications were documented and radiographic and functional outcomes were assessed. Results: Kaplan-Meier analysis revealed a 5-year implant survival of 91% (confidence interval 77%-96%). The 5-year survival with revision for any cause was 87% (CI 74%-94%). The overall revision rate was 16% (n = 8). Two patients required acetabular component revision due to aseptic loosening. Four patients (8%) suffered from periprosthetic infection: one patient was treated with a 2-stage revision, and another one with resection arthroplasty. The other 2 patients were treated with debridement, irrigation, and exchange of the mobile parts. Of 6 patients (12%) suffering from hip dislocation, 2 required implantation of a dual mobility acetabular component. The mean Harris Hip Score improved from 41 preoperatively to 79 at the latest follow-up (P < .001). Conclusion: Our findings demonstrate that an asymmetric acetabular component with extramedullary and optional intramedullary iliac fixation is a reliable and safe treatment method for periprosthetic PD resulting in good clinical and radiographic mid-term results.</p

Custom Made Monoflange Acetabular Components for the Treatment of Paprosky Type III Defects

Purpose: Patient-specific, flanged acetabular components are used for the treatment of Paprosky type III defects during revision total hip arthroplasty (THA). This monocentric retrospective cohort study analyzes the outcome of patients treated with custom made monoflanged acetabular components (CMACs) with intra- and extramedullary iliac fixation. Methods: 14 patients were included who underwent revision THA with CMACs for the treatment of Paprosky type III defects. Mechanism of THA failure was infection in 4 and aseptic loosening in 10 patients. Seven patients underwent no previous revision, the other seven patients underwent three or more previous revisions. Results: At a mean follow-up of 35.4 months (14–94), the revision rate of the implant was 28.3%. Additionally, one perioperative dislocation and one superficial wound infection occurred. At one year postoperatively, we found a significant improvement of the Western Ontario and McMaster Universities Arthritis Index (WOMAC) score (p = 0.015). Postoperative radiographic analysis revealed good hip joint reconstruction with a mean leg length discrepancy of 3 mm (−8–20), a mean lateralization of the horizontal hip center of rotation of 8 mm (−8–35), and a mean proximalization of the vertical hip center of rotation of 6 mm (13–26). Radiolucency lines were present in 30%. Conclusion: CMACs can be considered an option for the treatment of acetabular bone loss in revision THA. Iliac intra- and extramedullary fixation allows soft tissue-adjusted hip joint reconstruction and improves hip function. However, failure rates are high, with periprosthetic infection being the main threat to successful outcome