Precise wavelength determination of the 4s24p 2P3/2 - 2P1/2 transition in Mo11+ and Ru13+ ions

The 4s24p 2P3/2 – 2P1/2 magnetic dipole transition in Ga-like ions is interested in developing of high precise highly charged ion clock [Phys. Rev. A, 99, 02213(2019)]. In this work, we present direct observations of the transition in Mo11+ and Ru13+ ions at an electron beam ion trap. Internal and external calibration methods are used for determining the wavelength of the Mo11+ and Ru13+ lines, respectively. Both measurements reach precision levels of a few ppm. Compared with the available values, the current results significantly improve the experimental uncertainty.

Infant Warmer Equipped with Digital Weight Scales

Scales Scales in the world of health are used to measure human body weight such as baby scales. Newborns are very important to be weighed because it is used as a measure of the baby's health indication ranging from 2.4 kg to 4.2 kg. The author makes a tool for this to make it easier for users to weigh with a 7 segment display on the Infant Warmer tool and external calibration. By using a loadcell sensor with a maximum capacity of 5 kg, the loadcell can detect the weight of the load where the voltage generated by the loadcell of 0.7 mV at a load of 1 kg is amplified to 0.62 V by the PSA circuit using the AD620 IC and then processed by Arudino UNO as a microcontroller. The weight results will be displayed on the 7Segment display located on the Infant Warmer tool. In the study, the measured load included a weight of 0 kg to a maximum weight of 5 kg. The measurement of the data results was carried out 5 times each by comparing the modules that had been made with the standard weight, namely (lead). The data from the measurement results of the research module shows that when the weight of the measurement at 1 kg has an error percentage of 0.08%. Measurements at a weight of 2 kg have an error percentage of 0.05%. Measurement of weight 3 kg has a presentation error of 0.01%. Measurements at a weight of 4 kg have a presentation error of 0.02%. And measurements at a weight of 5 kg have an error percentage of 0.04%. Then the data from the measurement results of the research module shows the largest error presentation of 0.08% at a weight of 1 kg. And the data from the measurement results of the research module shows the smallest error presentation of 0.01% at a weight of 3 kg. Making a research module in the form of a scale placed on an infant warmer can make it easier for the wearer.

A plug-and-play platform of ratiometric bioluminescent sensors for homogeneous immunoassays

Heterogeneous immunoassays such as ELISA have become indispensable in modern bioanalysis, yet translation into point-of-care assays is hindered by their dependence on external calibration and multiple washing and incubation steps. Here, we introduce RAPPID (Ratiometric Plug-and-Play Immunodiagnostics), a mix-and-measure homogeneous immunoassay platform that combines highly specific antibody-based detection with a ratiometric bioluminescent readout. The concept entails analyte-induced complementation of split NanoLuc luciferase fragments, photoconjugated to an antibody sandwich pair via protein G adapters. Introduction of a calibrator luciferase provides a robust ratiometric signal that allows direct in-sample calibration and quantitative measurements in complex media such as blood plasma. We developed RAPPID sensors that allow low-picomolar detection of several protein biomarkers, anti-drug antibodies, therapeutic antibodies, and both SARS-CoV-2 spike protein and anti-SARS-CoV-2 antibodies. With its easy-to-implement standardized workflow, RAPPID provides an attractive, fast, and low-cost alternative to traditional immunoassays, in an academic setting, in clinical laboratories, and for point-of-care applications.

Simultaneous quantification of trimethylamine N-oxide, trimethylamine, choline, betaine, creatinine, and propionyl-, acetyl-, and l-carnitine in clinical and food samples using HILIC-LC-MS

Trimethylamine-N-oxide (TMAO), a microbiome-derived metabolite from the metabolism of choline, betaine, and carnitines, is associated to adverse cardiovascular outcomes. A method suitable for routine quantification of TMAO and its precursors (trimethylamine (TMA), choline, betaine, creatinine, and propionyl-, acetyl-, and l-carnitine) in clinical and food samples has been developed based on LC-MS. TMA was successfully derivatized using iodoacetonitrile, and no cross-reactions with TMAO or the other methylamines were detected. Extraction from clinical samples (plasma and urine) was performed after protein precipitation using acetonitrile:methanol. For food samples (meatballs and eggs), water extraction was shown to be sufficient, but acid hydrolysis was required to release bound choline before extraction. Baseline separation of the methylamines was achieved using a neutral HILIC column and a mobile phase consisting of 25 mmol/L ammonium formate in water:ACN (30:70). Quantification was performed by MS using external calibration and isotopic labelled internal standards. The assay proved suitable for both clinical and food samples and was linear from ≈ 0.1 up to 200 μmol/L for all methylamines except for TMA and TMAO, which were linear up to 100 μmol/L. Recoveries were 91–107% in clinical samples and 76–98% in food samples. The interday (n=8, four duplicate analysis) CVs were below 9% for all metabolites in clinical and food samples. The method was applied successfully to determine the methylamine concentrations in plasma and urine from the subjects participating in an intervention trial (n=10) to determine the effect of animal food ingestion on methylamine concentrations. Graphical abstract

Median based absolute quantification of proteins using Fully Unlabelled Generic Internal Standard

By reporting molar abundances of proteins, absolute quantification determines their stoichiometry in complexes, pathways or networks and also relates them to abundances of non-protein biomolecules. Typically, absolute quantification relies either on protein- specific isotopically labelled peptide standards or on a semiempirical calibration against the average abundance of peptides chosen from arbitrary selected standard proteins. Here we developed a generic protein standard FUGIS (Fully unlabelled Generic Internal Standard) that requires no isotopic labelling, synthesis of standards or external calibration and is applicable to proteins of any organismal origin. FUGIS is co-digested with analysed proteins and enables their absolute quantification in the same LC-MS/MS run. By using FUGIS, median based absolute quantification (MBAQ) workflow provides similar quantification accuracy compared to isotopically-labelled peptide standards and outperforms methods based on external calibration or selection of best ionized reporter peptides (e.g. Top3 quantification) with a median quantification error below 20%