Mechanically Robust, Inkjet-Printable Polymer Nanocomposites with Hybrid Gold Nanoparticles and Metal-like Conductivity.

Hybrid core-shell nanoparticles with metal cores and conductive polymer shells yield materials that are sinter-free and highly conductive but mechanically weak. Conventional composites of such nanoparticles are electrically insulating. Here, we introduce microscale phase-separated nanocomposites of hybrid gold-PEDOT:PPS particles in insulating poly(vinyl alcohol) (PVA). They combine electrical conductivities of up to 2.1 × 105 S/m at 10 vol % PVA with increased mechanical adhesion on polyethylene terephthalate and glass substrates. We studied the effects of the PVA molecular weight, hydrolyzation degree, and volume fraction. Composites with 10 vol % highly hydrolyzed PVA at a MW of 89-98 kDa had the highest conductivities and stabilities; highly hydrolyzed PVA even increased the conductivity of the hybrid particle layers. We propose the formation of hydrogen bonds between PVA and PEDOT:PSS that lead to demixing and the formation of stable, structured composites. Finally, we demonstrated the inkjet-printability of inks containing PVA in water with viscosities of 1.6-2.0 Pa s at 50.1 s-1 and prepared bending-resistant electrical leads.

Management of acute appendicitis during COVID-19 pandemic. Single center data from a tertiary care hospital in Germany.

Objectives: The unexpected global overload of the health system during COVID-19 pandemic has caused changes in management of acute appendicitis worldwide. Whereas conservative treatment was widely recommended, the appendicectomy remained standard therapy in Germany. We aimed to investigate the impact of COVID-19 pandemic on treatment routine for acute appendicitis at University Hospital of Magdeburg. Methods: Adult patients with clinical and/or radiological diagnosis of acute appendicitis were included in the single center retrospective study. Data was collected to patient demographics, treatment modality and outcomes including morbidity and length of stay. The patient data related to COVID-19 period from March 22, 2020 to December 31, 2021 (649 days) were compared to the Non-COVID-19 period from June 12, 2018 to March 21, 2020 (649 days). Subgroup analysis related to conservative or surgical treatment has been performed. Results: A total of 385 patients was included in the study, 203 (52.73 %) during Non-COVID-19 period and 182 (47.27 %) during COVID-19 period. Mean age of entire collective was 43.28 years, containing 43.9 % female patients (p=0.095). Conservative treatment was accomplished in 49 patients (12.7 % of entire collective), increasing from 9.9 % to 15.9 % during COVID-19 period (p=0.074). Laparoscopic appendicectomy was performed in 99.3 % (n=152) of operated patients during COVID-19 period (p=0.013), followed by less postoperative complications compared to reference period (23.5 % vs. 13.1 %, p=0.015). The initiation of antibiotic therapy after the diagnosis increased from 37.9 % to 53.3 % (p=0.002) during COVID-19 period regardless the following treatment modality. Antibiotic treatment showed shorter duration during pandemic period (5.57 days vs. 3.16 days, p<0.001) and it was given longer in the conservative treatment group (5.63 days vs. 4.26 days, p=0.02). The overall length of stay was shorter during COVID-19 period (4.67 days vs. 4.12 days, p=0.052) and in the conservative treatment group (3.08 days vs. 4.47 days, p<0.001). However, the overall morbidity was lower during the COVID-19 period than before (17.2 % vs. 7.7 %, p=0.005) and for conservative therapy compared to appendicectomy (2 % vs. 14.3 %, p=0.016). There was no mortality documented. Conclusions: According to our findings the COVID-19 pandemic had a relevant impact on treatment of acute appendicitis, but it was possible to maintain the traditional diagnostic and treatment pathway. Although laparoscopic appendicectomy remains a recommended procedure, the conservative treatment of uncomplicated appendicitis with excellent short-term outcome can be a safe alternative to surgery during potential new wave of COVID-19 pandemic and in the daily routine.

Mechanochemical Synthesis of Mn3O4 Nanocrystals and Their Lithium Intercalation Capability.

Syntheses of Mn3O4 involve either high sintering temperatures to produce well crystallized products or the use of water-soluble precursors, surfactants, and organic solvents to generate nanocrystalline products. Mechanochemical approaches are known to be effective in the preparation of fine-grained or nanoscaled materials, while also being environmentally friendly because no solvents and no sintering at high temperatures are required. We report the solvent free mechanochemical synthesis of Mn3O4 nanocrystals at room temperature, from a mixture of MnO and Mn2O3. The single-phase product was characterized by Rietveld refinement and SEM images. The obtained crystallite size was 14.2(2) nm, which is among the smallest ever produced crystallite sizes of Mn3O4. The obtained product reveals an enormous increase in lithium intercalation capability, which was proven via chemical lithium intercalation at room temperature. More than 50% lithiation of nanocrystalline Mn3O4 is observed after a reaction time of 1 h, while coarse-grained material from a solid-state reaction shows no intercalation under the same reaction conditions. Therefore, the produced manganese oxide has a high potential in lithium battery applications.

Automated Analytical Measurement Processes Using a Dual-Arm Robotic System.

The demand for automation in the analytical laboratory is high. In contrast to well-automated bioscreening and high-throughput and high-content screening processes, analytical measurement procedures are complex in their structure and changing frequently. Not only do robotic units have to perform transportation or specific single tasks, but also flexible robots are needed to cover several tasks, including transportation and direct sample manipulation. Due to their human-like structure, dual-arm robots are predestined for analytical measurement processes. A new study published in the journal Energies presents a novel integration of electronic piston pipettes into an automation system using a dual-arm robot to perform liquid handling tasks similar to human operators. In this commentary, the main findings are highlighted and discussed.

Application of a Dual-Arm Robot in Complex Sample Preparation and Measurement Processes.

Automation systems with applied robotics have already been established in industrial applications for many years. In the field of life sciences, a comparable high level of automation can be found in the areas of bioscreening and high-throughput screening. Strong deficits still exist in the development of flexible and universal fully automated systems in the field of analytical measurement. Reasons are the heterogeneous processes with complex structures, which include sample preparation and transport, analytical measurements using complex sensor systems, and suitable data analysis and evaluation. Furthermore, the use of nonstandard sample vessels with various shapes and volumes results in an increased complexity. The direct use of existing automation solutions from bioscreening applications is not possible. A flexible automation system for sample preparation, analysis, and data evaluation is presented in this article. It is applied for the determination of cholesterol in biliary endoprosthesis using gas chromatography-mass spectrometry (GC-MS). A dual-arm robot performs both transport and active manipulation tasks to ensure human-like operation. This general robotic concept also enables the use of manual laboratory devices and equipment and is thus suitable in areas with a high standardization grade.