Application Scenarios in Streaming-Oriented Embedded-System Design

A design method for handling increasingly dynamic real-time embedded-system applications can help developers cope with stringent system and market requirements. This method groups an application's operation modes into application scenarios and describes how to incorporate them in the overall design process. An automated scenario-based design trajectory reduces the energy consumption of a streaming application running on a single processor platform via dynamic voltage and frequency scaling.     

Effect of Inert Gas Flow Rate on Homogenization and Inclusion Removal in a Gas Stirred Ladle

In the present study, the effect of gas flow rate on homogenization and inclusion removal in a gas stirred ladle was investigated. Both industrial trials and cold model experiments were conducted. CFD calculation was also carried out as an auxiliary tool. The mixing times predicted by CFD simulation agreed well with both the model experiments and industrial data. 99% mixing could be achieved in about 2–3 minutes. The increase of flow rate of inert gas would not improve the mixing substantially, while the mixing time decreased somewhat with the increase of gas flow rate. The water model study showed also that the gas flow rate had a negligible effect on the rate of inclusion removal. Both the experiments and CFD calculation strongly suggested that a low gas flow rate should be applied in the ladle treatment.     

Nucleoside Analogs and Perylene Derivatives Modulate Phase Separation of SARS-CoV-2 N Protein and Genomic RNA In Vitro

The life cycle of severe acute respiratory syndrome coronavirus 2 includes several steps that are supposedly mediated by liquid–liquid phase separation (LLPS) of the viral nucleocapsid protein (N) and genomic RNA. To facilitate the rational design of LLPS-targeting therapeutics, we modeled N-RNA biomolecular condensates in vitro and analyzed their sensitivity to several small-molecule antivirals. The model condensates were obtained and visualized under physiological conditions using an optimized RNA sequence enriched with N-binding motifs. The antivirals were selected based on their presumed ability to compete with RNA for specific N sites or interfere with non-specific pi–pi/cation–pi interactions. The set of antivirals included fleximers, 5′-norcarbocyclic nucleoside analogs, and perylene-harboring nucleoside analogs as well as non-nucleoside amphiphilic and hydrophobic perylene derivatives. Most of these antivirals enhanced the formation of N-RNA condensates. Hydrophobic perylene derivatives and 5′-norcarbocyclic derivatives caused up to 50-fold and 15-fold enhancement, respectively. Molecular modeling data argue that hydrophobic compounds do not hamper specific N-RNA interactions and may promote non-specific ones. These findings shed light on the determinants of potent small-molecule modulators of viral LLPS.     

Microarray Profiling of Vaccination-Induced Antibody Responses to SARS-CoV-2 Variants of Interest and Concern

Mutations in surface proteins enable emerging variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) to escape a substantial fraction of neutralizing antibodies and may thus weaken vaccine-driven immunity. To compare available vaccines and justify revaccination, rapid evaluation of antibody (Ab) responses to currently circulating SARS-CoV-2 variants of interest (VOI) and concern (VOC) is needed. Here, we developed a multiplex protein microarray-based system for rapid profiling of anti-SARS-CoV-2 Ab levels in human sera. The microarray system was validated using sera samples from SARS-CoV-2-free donors and those diagnosed with COVID-19 based on PCR and enzyme immunoassays. Microarray-based profiling of vaccinated donors revealed a substantial difference in anti-VOC Ab levels elicited by the replication-deficient adenovirus vector-base (Sputnik V) and whole-virion (CoviVac Russia COVID-19) vaccines. Whole-virion vaccine-induced Abs showed minor but statistically significant cross-reactivity with the human blood coagulation factor 1 (fibrinogen) and thrombin. However, their effects on blood clotting were negligible, according to thrombin time tests, providing evidence against the concept of pronounced cross-reactivity-related side effects of the vaccine. Importantly, all samples were collected in the pre-Omicron period but showed noticeable responses to the receptor-binding domain (RBD) of the Omicron spike protein. Thus, using the new express Ab-profiling system, we confirmed the inter-variant cross-reactivity of the anti-SARS-CoV-2 Abs and demonstrated the relative potency of the vaccines against new VOCs.     

Four-Component Relativistic Calculations of NMR Shielding Constants of the Transition Metal Complexes—Part 2: Nitrogen-Coordinated Complexes of Cobalt

Both four-component relativistic and nonrelativistic computations within the GIAO-DFT(PBE0) formalism have been carried out for ¹⁵N and ⁵⁹Co NMR shielding constants and chemical shifts of a number of the nitrogen-coordinated complexes of cobalt. It was found that the total values of the calculated nitrogen chemical shifts of considered cobalt complexes span over a range of more than 580 ppm, varying from −452 to +136 ppm. At that, the relativistic corrections to nitrogen shielding constants and chemical shifts were demonstrated to be substantial, changing accordingly from ca. −19 to +74 ppm and from −68 to +25 ppm. Solvent effects on ¹⁵N shielding constants and chemical shifts were shown to have contributions no less important than the relativistic effects, namely from −35 to +63 ppm and from −74 to +23 ppm, respectively. Cobalt shielding constants and chemical shifts were found to vary in the ranges of, accordingly, −20,157 to −11,373 ppm and from +3781 to +13,811. The relativistic effects are of major importance in the cobalt shielding constants, resulting in about 4% for the shielding-type contributions, while solvent corrections to cobalt shielding constants appeared to be of less significance, providing corrections of about 1.4% to the gas phase values.     

Design and Validation of a Sensitive Multisteroid LC-MS/MS Assay for the Routine Clinical Use: One-Step Sample Preparation with Phospholipid Removal and Comparison to Immunoassays

Steroid analysis in clinical laboratories is dominated by immunoassays (IAs) that have a high sample turnover but are inherently limited in trueness, precision, and sensitivity. Liquid chromatography coupled to mass spectrometry (LC-MS/MS) has proved to be a far more capable tool, delivering better sensitivity, specificity, and the possibility of parallel analysis of multiple steroids and metabolites, providing the endocrinologist with more reliable and comprehensive diagnostic information. An LC-MS/MS assay with gradient elution over less than eight minutes and a one-step sample preparation combining protein precipitation with phospholipid removal of off-line solid-phase extraction was developed and validated. It allowed the quantification of 11-deoxycorticosterone (11-DOC), 11-deoxycortisol (11-DF), 17-OH-progesterone (17P), 21-deoxycortisol (21-DF), androstenedione (ANDRO), aldosterone (ALDO), corticosterone (CC), cortisol (CL), cortisone (CN), dehydroepiandrosterone (DHEA), dehydroepiandrosterone sulfate (DHEAS), dihydrotestosterone (DHT), estradiol (E2), progesterone (PROG), and testosterone (TES) in human serum. Interday imprecision was generally better than 15%, trueness was proven by recovery experiments with ISO 17034-certified reference materials, proficiency testing (UK NEQAS), and measuring serum reference standards. In-house comparison against IVD-CE-certified immunoassays (IA) for 17P, ANDRO, CL, DHEAS, E2, PROG, and TES was conducted by assessing leftover routine patient samples and purpose-built patient serum pools. None of the compared routine IAs were meeting the standards of the LC-MS/MS. Insufficient overall comparability was found for ANDRO and 17P (mean bias > +65%). Accuracy limitations at lower concentrations were present in IAs for PROG, E2, and TES.     

Parahydrogen-Induced Hyperpolarization of Unsaturated Phosphoric Acid Derivatives

Parahydrogen-induced nuclear polarization offers a significant increase in the sensitivity of NMR spectroscopy to create new probes for medical diagnostics by magnetic resonance imaging. As precursors of the biocompatible hyperpolarized probes, unsaturated derivatives of phosphoric acid, propargyl and allyl phosphates, are proposed. The polarization transfer to ¹H and ³¹P nuclei of the products of their hydrogenation by parahydrogen under the ALTADENA and PASADENA conditions, and by the PH-ECHO-INEPT+ pulse sequence of NMR spectroscopy, resulted in a very high signal amplification, which is among the largest for parahydrogen-induced nuclear polarization transfer to the ³¹P nucleus.     

Effect of the Slag Composition on the Process Behavior,Energy Consumption,and Nonmetallic Inclusions during Electroslag Remelting

Electroslag remelting (ESR) is an important process to produce high-quality tool steels. The slag composition has a strong effect on the remelting behavior, particularly on energy consumption and the removal of nonmetallic inclusions (NMI). The latter aspect is strongly related to chemical reactions between the slag and the metal and determines the necessary composition of the slag. Also, the electrical conductivity of the slag is determined by the slag composition, and a high resistivity is desirable. The effect of different slag compositions with 0%–60% CaF₂ and a corresponding wide range of electrical conductivities is investigated regarding slag movement, slag surface temperature, and slag skin thickness, as well as their impact on chemical reactions and the removal of NMI. Therefore, a laboratory-scale ESR unit and the plastic mold steel X40Cr14 are used for the experimental trials. The results show a strong impact on the remelting behavior as well as on the specific energy consumption ranging from ≈900 to over 1700 kWh h⁻¹. The findings from the chemical analysis and detection of NMI indicate that a similar metallurgical behavior is feasible, leading to comparable amounts of dominantly Al₂O₃–MgO-type inclusions with some variation due to different activities in the slag.     

Second-Generation CD73 Inhibitors Based on a 4,6-Biaryl-2-thiopyridine Scaffold

Various series of 4,6-biaryl-2-thiopyridine derivatives were synthesized and evaluated as potential ecto-5′-nucleotidase (CD73) inhibitors. Two synthetic routes were explored and the coupling of 4,6-disubstituted 3-cyano-2-chloro-pyridines with selected thiols allowed us to explore the structural diversity. Somehow divergent results were obtained in biological assays on CD73 inhibition using either the purified recombinant protein or cell-based assays, highlighting the difficulty to target protein-protein interface on proteins existing as soluble and membrane-bound forms. Among the 18 new derivatives obtained, three derivatives incorporating morpholino substituents on the 4,6-biaryl-2-thiopyridine core were shown to be able to reverse the adenosine-mediated immune suppression on human T cells. The higher blockade efficiency was observed for 2-((3-cyano-4,6-bis(4-morpholinophenyl)pyridin-2-yl)thio)-N-(isoxazol-3-yl)acetamide (with total reversion at 100 μM) and methyl 2-((3-cyano-4,6-bis(4-morpholinophenyl)pyridin-2-yl)thio)acetate (with partial reversion at 10 μM). Thus, this series of compounds illustrates a new chemotype of CD73 allosteric inhibitors.