Parallel Measurements Research Articles

An integrated wavemeter based on fully-stabilized resonant electro-optic frequency comb

Optical frequency combs provide a powerful tool for precise measurement of the optical frequency, holding significant importance in fields such as spectroscopy, optical communication and optical clock. The frequency stability of the comb line determines the precision of the frequency measurement, but the delicate interplay between high precision, low power consumption and integration still needs to be optimized. To this aim, here we demonstrate a frequency measurement scheme based on a fully stabilized electro-optic comb, in which the pump laser frequency and repetition rate are independently locked to the atomic transition and microwave signal. The measurement precision of the demonstrated wavemeter can reach sub-kHz-level, and the parallel measurement of multiple wavelengths can be performed. Therefore, by combining the technical scheme reported here with advanced integrated functional devices, our system is expected to provide a feasible solution for chip-scale frequency precision measurement and reference.

Comparison of Sunshine Duration Measurements between the Campbell–Stokes Sunshine Recorder and Three Automatic Sensors at Three Locations in Cyprus

This paper compares the daily sunshine duration (SD) measured by the Campbell–Stokes sunshine recorder (CS) with three automatic instruments (Kipp & Zonen pyranometers (CM6 B), pyrheliometer (CHP1) and CSD3 sunshine recorders). The comparisons are essential, since recently, automatic sunshine duration sensors have been replacing the manual measurements, affecting, therefore, the continuity of the CS time series. The comparisons were applied to the daily SD data of three synoptic stations (Larnaca A/P, Pafos A/P and Athalassa) where parallel measurements of manual and automatic instruments are carried out during the periods 2009–2012 and 2012–2015. The CSD3 measurements were obtained from two automatic weather stations (AWSs) which are close to the synoptic station of Larnaca A/P. The comparisons referred to the daily and monthly sums of sunshine duration, as well as to their statistical distributions and their relationships. The daily differences in the pairs of sunshine recorders installed at the same location are mostly within the range of −1.0 to +1.0 h. At Larnaca, in the period 2009–2012, the pyranometric method’s (Gl) values were higher than the CS in the summer months. Pafos and Athalassa showed higher values of CS compared to Gl and the pyrheliometric method (Pr), respectively, almost throughout the year. Generally, the annual average daily differences between the different pairs range between 0.3 and 0.5 h. Regression equations were determined allowing the estimation of daily SD under different sky conditions. The coefficient of determination (R2) reached the values of 0.91 and 0.96 under ‘all sky’ conditions, and between 0.80 and 0.91 under ‘clear’ sky conditions at the three locations.

Characterization of single synthetic polymers via magnetic tweezers

AbstractDue to the ability to perform the parallel measurement of multiple single chains and exert precise control over stretching force in the sub‐nanonewton regime, magnetic tweezers (MT) are a suitable tool to study the individual chain conformations and inherent behaviors of polymers. Herein, we examined the applications of MT in studying single synthetic polymers, distinct from previous reviews focusing on biological polymers such as DNAs. We first presented an overview of the technical aspects of MT, including the imaging setup, the algorithm of three‐dimensional single particle tracking, the configuration of magnets, the calibration and control of magnetic forces, the assembly of flow cells, and the polymer tethering methods. Then, we discussed selected examples highlighting the utilization of MT in studying the chain conformation, mechanical properties, ion and ligands effect, regime transition mechanism, and polymerization dynamics of single synthetic polymers. We envision that MT can serve as a powerful toolbox for delving into the structure–property correlations at the single chain level, which provides quantitative validations for building the theoretical models of synthetic polymers. In the end, we contemplated potential avenues and opportunities for future research in this domain.

High‐accuracy optical delay measurement based on linear frequency sweeping technology

AbstractA high‐accuracy and wide‐range optical delay measurement method based on linear frequency modulation (LFM) of a microwave source is proposed, which can measure the delay of each channel in a parallel multichannel interference structure. The light wave emitted by the light source is injected into the dual‐parallel Mach‒Zehnder modulator (DPMZM) as a carrier wave. The LFM microwave signal is loaded into the radio frequency ports of the DPMZM through a 90° hybrid couple, and the bias voltages of the DPMZM are adjusted to make it work in carrier suppression single sideband (CS‐SSB) modulation mode. The CS‐SSB optical signal output by the modulator enters the test links, including a Mach‒Zehnder interference loop composed of the reference arm and the device under test arm. Then, the output optical signal of the interference loop is input into a photodetector, and the intermediate frequency (IF) signals are obtained by the beat frequency. The frequency of the IF signal is obtained through data acquisition and fast Fourier transform calculation. Thus, the delay time is calculated. By increasing or decreasing the LFM signal scanning time, the delay measurement range can be extended, or the measurement accuracy over a short distance can be improved. The feasibility of this method is verified by experiments, and the delay of parallel multichannel measurement is carried out.

A comprehensive review on methane's dual role: effects in climate change and potential as a carbon-neutral energy source.

The unprecedented population and anthropogenic activity rise have challenged the future look up for shifts in global temperature and climate patterns. Anthropogenic activities such as land fillings, building dams, wetlands converting to lands, combustion of biomass, deforestation, mining, and the gas and coal industries have directly or indirectly increased catastrophic methane (CH4) emissions at an alarming rate. Methane is 25 times more potent trapping heat when compared to carbon dioxide (CO2) in the atmosphere. A rise in atmospheric methane, on a 20-year time scale, has an impact of 80 times greater than that of CO2. With increased population growth, waste generation is rising and is predicted to reach 6 Mt by 2025. CH4 emitted from landfills is a significant source that accounts for 40% of overall global methane emissions.Various mitigation and emissions reduction strategies could significantly reduce the global CH4burden at a cost comparable to the parallel and necessary CO2reduction measures, reversing the CH4burden to pathways that achieve the goals of the Paris Agreement. CH4mitigation directly benefits climate change, has collateral impacts on the economy, human health, and agriculture, and considerably supports CO2mitigation. Utilizing the CO2from the environment, methanogens produce methane and lower their carbon footprint. NGOs and the general public should act on time to overcome atmospheric methane emissions by utilizing the raw source for producing carbon-neutral fuel. However, more research potential is required for green energy production and to consider investigating the untapped potential of methanogens for dependable energy generation.

Budgetary process development at the local level: foreign expertise

This paper highlights the foreign expertise of the budgetary process development at the local level. It states that the armed aggression of the Russian Federation resulted in significant damage to the economy of Ukraine, affecting thus the development of the budgetary process. Modern scholars studying the domestic budgetary process, including its local dimension, are listed.
 The aim of the research is to perform a critical review of the foreign experience regarding the budgetary process development at local level.
 This paper highlights the concept of the budgetary process in Ukraine, the essentials of its five stages, the reasons for the low quality of the budgetary process in Ukraine, the core principles being followed in the European Union states in the process of securing selected tax revenues for local self-government bodies, essential factors determining the possibility to assign certain taxes within the local category, the main characteristics of the local budgets’ revenue share establishment in developed Western countries, distinguishing these from domestic practice. It is emphasized that for all developed foreign states division of local budgets into local operational (administrative) budget and local development budget (investment budget) is typical. It is stressed that the main focus of budgetary policy in the countries of Central and Eastern Europe was placed on decreasing the amount of transfers and taking parallel measures to raise the share of tax revenues, ensuring the establishment of self-sufficient and financially capable territorial communities. Аuthor paid special attention to research of budgetary process specificity in Germany, United Kingdom and France.
 The conclusions contain a statement for the budgetary process of any country to be characterized by certain features reflecting the specificity of national economy regulation, the structure of domestic production and means of influencing the development of the financial system. Modern global trends are characterized by the increasing importance of decentralization in the organization of local financial systems and changes in budgetary processes at the local level.

Homogenization of daily temperatures using covariates and statistical learning—The case of parallel measurements

AbstractA data driven method based on generalized additive modelling (GAM) has been developed for homogenizing daily minimum and maximum temperature (TN, TX) series using parallel measurements and covariates. The method is applied to two coastal and two inland stations in the Netherlands. Between 1950 and 1972, these stations were relocated from cities to airports, accompanied by parallel measurement of at least 5 years at the old and new sites. Separating these parallel measurements in training and test data, the method compares numerous models involving covariates like the wind vector, cloudiness, specific humidity and sea surface temperature, and selects a model for each station. The resulting models offer an improvement compared to models based on temperature and season only: seasonal dependence is largely replaced by dependence on physical quantities. However, quantitatively, the impact is not large in the cases studied. One of the reasons might be that some covariates have only been measured at specific times not coinciding with the occurrences of the temperature minima or maxima. Additional benefits of the method are robustness and estimation of the sampling error variance of the daily homogenized daily temperature values.

Direct Comparison between Förster Resonance Energy Transfer and Light-Induced Triplet-Triplet Electron Resonance Spectroscopy.

To carry out reliable and comprehensive structural investigations, the exploitation of different complementary techniques is required. Here, we report that dual triplet-spin/fluorescent labels enable the first parallel distance measurements by electron spin resonance (ESR) and Förster resonance energy transfer (FRET) on exactly the same molecules with orthogonal chromophores, allowing for direct comparison. An improved light-induced triplet-triplet electron resonance method with 2-color excitation is used, improving the signal-to-noise ratio of the data and yielding a distance distribution that provides greater insight than the single distance resulting from FRET.

Fabrication of an electrochemical sensor based on molecular imprinting strategy for detecting salidroside

In recent years, molecular imprinting has emerged as a promising strategy for developing highly selective and sensitive sensors for various analytes. In this study, we present the fabrication and characterization of an electrochemical sensor based on the molecular imprinting strategy for the detection of salidroside, a bioactive compound found in Rhodiola rosea. The sensor employs a modified glassy carbon electrode functionalized with multi-walled carbon nanotubes (MWCNTs) as the working electrode. The molecularly imprinted polymer (MIP) was prepared using acrylamide as the functional monomer and MWCNTs as the supporting material. The MIP-based sensor exhibited exceptional sensitivity and selectivity towards salidroside, showing a linear correlation between the logarithm of salidroside concentration and the reduced peak current in the range of 1 nM to 1 μM, with a low detection limit of 0.51 nM. The sensor demonstrated excellent reproducibility and stability, with a relative standard deviation (RSD) of 3.1 % for parallel measurements and 94.8 % retained response after a 7-day storage period. The spiked recovery experiments for Rhodiola rosea samples yielded high accuracy and precision, with recovery rates ranging from 96 % to 99 % and RSDs of 1–4 %. The developed MIP-based electrochemical sensor offers a powerful and reliable approach for the detection of salidroside, holding great potential for applications in pharmaceutical and herbal medicine industries.

New design of microchip for in-situ DLS measurement of colloidal suspensions

Stability of dispersed materials remains an important question in a wide variety of fields such as cosmetics, catalysis, food or energy and the environment. As stability is directly linked to the size of the dispersed colloids it is essential to assess the size distribution of colloidal suspensions. Nowadays, microfluidic-based approaches generate increasing interest as they represent flexible and fast measurements allowing high throughput experimentations. However, characterization of colloidal dispersions is usually performed by dynamic light scattering (DLS), that requires static measurements as well as significant volumes, that are not compatible with on-line analysis and microfluidics. Moreover, due to flow-induced decorrelation terms, DLS measurements in microfluidic channels are only accurate at very low shear rates. This work aimed at developing an on-line microfluidic device for dispersed materials characterization using DLS. The main challenges of this project were i) to adapt the microfabrication of the PDMS device in order to combine microchannels of hundreds of microns with a milli-fluidic cavity to perform the DLS measurements, and ii) to downsize the DLS set up. A PDMS microchip, consisting in a millimeter cavity for DLS measurements in parallel with a microchannel, was designed to perform the measurement on the sample without stopping the suspension flow during the microfluidic experiment. The cavity geometry was then optimized thanks to numerical simulation to ensure a good sweep efficiency and to downscale as much as possible without impairing the DLS signal. By adapting the microfabrication process, a PDMS microfluidic chip was designed allowing the size measurements of successive suspensions containing 100 and 12 ​nm diameter particles. This work is a first step towards the implementation of a new technological building block for online microfluidic characterization. © 2017 Elsevier Inc. All rights reserved.

An Investigation of High-Z Material for Bolus in Electron Beam Therapy

Electron beams are frequently used for superficial tumors including: primary skin cancers, surgical scars, cutaneous lymphomas and benign conditions like keloids. However, due to electron beam characteristics the surface dose is 75-95% of the prescribed dose depending on beam energy thus requiring placement of bolus to augment surface dose. Various types of boluses; wet gauge/towel, superflab, superstuff, aquaplast, 3D printed plastics, customized dot-decimal bolus, thermoshield, brass and tantalum wire mesh are commonly used in clinics with variable difficulties that are not perfect. As majority of these devices do not snug to the skin contour and create air-gap that is known to produce significant dose perturbations creating hot and cold spot. The variable dosimetry has cosmetic implications and potentially increased risk of recurrence. A new cloth-like high-Z materials; Tungsten, (Z = 74) and Bismuth, (Z = 83) impregnated with silicone gel are now commercially available which is investigated in this study for bolus purpose. Commercially available, super soft silicone-gel based submillimeter thin Tungsten and Bismuth sheets were investigated for bolus properties in electron beams in the range of 6-12 MeV using 10x10 cm2 applicator. These materials were tested on various body contour for perfect snug without any air traps. Using parallel plate ion chamber measurements were performed in a solid water phantom on a medical linear accelerator machine. Depth dose characteristics were measured to optimize the thickness for surface dose to be 100% for selected electron therapy. Surface dose for a 10x10 cm2 cone for 6, 9, 12 MeV beams were measured to be 75.1%, 80.1% and 86.2%, respectively. Silicone-gel Tungsten and Bismuth sheets produce significant electrons thus increasing surface dose. Based on measured depth dose, our data showed that Tungsten sheets of 0.14 mm, 0.18 mm and 0.2 mm and Bismuth sheets of 0.42 mm, 0.18 mm and 0.2 mm provide 100% surface dose for 6, 9 and 12 MeV beams, respectively without any changes in depth dose except increasing surface dose. The new Tungsten and Bismuth based silicone-gel clothlike sheets are extremely soft but high tensile metallic bolus materials that can fit flawlessly on any skin contour without any air trap or variable thickness or spillage of the water as in conventionally used wet gauge. Only 0.2 mm thick sheets are needed for 100% surface dose without degradation of the depth dose characteristics. These materials are reusable and ideal for bolus in electron beam treatment. This investigation opens a new frontier in designing new bolus materials optimum for patient treatment.

Analyzing force measurements of multi-cellular clusters comprising indeterminate geometries.

Multi-cellular biomimetic models often comprise heterogenic geometries. Therefore, quantification of their mechanical properties-which is crucial for various biomedical applications-is a challenge. Due to its simplicity, linear fitting is traditionally used in analyzing force-displacement data of parallel compression measurements of multi-cellular clusters, such as tumor spheroids. However, the linear assumption would be artificial when the contact geometry is not planar. We propose here the integrated elasticity (IE) regression, which is based on extrapolation of established elastic theories for well-defined geometries, and is free, extremely simple to apply, and optimal for analyzing coarsely concave multi-cellular clusters. We studied here the quality of the data analysis in force measurements of tumor spheroids comprising different types of melanoma cells, using either the IE or the traditional linear regressions. The IE regression maintained excellent precision also when the contact geometry deviated from planarity (as shown by our image analysis). While the quality of the linear fittings was relatively satisfying, these predicted smaller elastic moduli as compared to the IE regression. This was in accordance with previous studies, in which the elastic moduli predicted by linear fits were smaller compared to those obtained by well-established methods. This suggests that linear regressions underestimate the elastic constants of bio-samples even in cases where the fitting precision seems satisfying, and highlights the need in alternative methods as the IE scheme. For comparison between different types of spheroids we further recommend to increase the soundness by regarding relative moduli, using universal reference samples.

A-002 The Prevalence of the High Sensitivity Cardiac Troponin I Outlier and False Positivity Rates on Beckman Coulter Access DxI

Abstract Background The false positive elevation in high sensitivity cardiac troponin I (hsTnI) can be triggered by many factors, for example, fibrin clots, heterophile antibodies, or other sources of troponin interferences. These interferences lead to inaccurate hsTnI results. These inaccurate results described in the literature as the “outliers”. Published studies use statistical tools to identify the outliers based on the discrepancies between the two repeat values. Depending on the instrument platform and the study design, the outlier rate for the conventional troponin I assay was reported from 0.44% to 1.01% (1, 2). In our laboratory, the false positivity rate for the conventional troponin assay on Beckman Coulter DxI platform was determined as 1% (unpublished data). This study aim was to determine both the statistically and clinically significant outliers for hsTnI assay on the Beckman Coulter Access DxI instrument in the academic medical center clinical laboratory setting. Methods A unique test repeat protocol was created. Two parallel hsTnI measurements are conducted in lithium heparin tubes (BD Vacutainer) on Beckman Coulter DXI 800 systems. When the difference between the two results is greater than 30%, a third repeat is automatically ordered and run after additional centrifugation at a higher relative centrifugal force. The outlier determination is based on assessing the difference between the first two values using previously described statistical analysis tools (1). The clinically significant outlier was determined by counting positive results in the first two runs which are not unconfirmed by the third run, i.e., false positive results. Gender specific cutoffs, 14 ng/L for female and 19 ng/L for male, were applied to identify the positive results. Overall, 2935 patients’ results were evaluated during the study. Results Based on the analysis of the first two repeat runs, out of 2935 samples 16 samples, or 0.54%, were identified as the statistical outliers. 2 out of these 16 outliers, or 12.5%, were negative results. Taking into consideration the third repeat data, 13 out of 2935 samples, or 0.44%, were identified as false positive results. Only 9 out of 13 false positive results, or 69.2%, were identified using the statistical approach above. Conclusion The false positivity rate of hsTnI testing has dropped significantly from 1% to 0.44% in a setting of our laboratory. Our refined repeat protocol approach significantly increases the clinician’s confidences in the hsTnI results by capturing potential false positive results. This approach addresses the outliers at an additional expense like reagents, instrument wear and tear, and labor. Therefore, a more robust methodology is still desired by the industry.

Cortical temporal integration can account for limits of temporal perception: investigations in the binaural system

The auditory system has exquisite temporal coding in the periphery which is transformed into a rate-based code in central auditory structures, like auditory cortex. However, the cortex is still able to synchronize, albeit at lower modulation rates, to acoustic fluctuations. The perceptual significance of this cortical synchronization is unknown. We estimated physiological synchronization limits of cortex (in humans with electroencephalography) and brainstem neurons (in chinchillas) to dynamic binaural cues using a novel system-identification technique, along with parallel perceptual measurements. We find that cortex can synchronize to dynamic binaural cues up to approximately 10 Hz, which aligns well with our measured limits of perceiving dynamic spatial information and utilizing dynamic binaural cues for spatial unmasking, i.e. measures of binaural sluggishness. We also find that the tracking limit for frequency modulation (FM) is similar to the limit for spatial tracking, demonstrating that this sluggish tracking is a more general perceptual limit that can be accounted for by cortical temporal integration limits.

High-throughput, fluorescent-aptamer-based measurements of steady-state transcription rates for the Mycobacterium tuberculosis RNA polymerase.

The first step in gene expression is the transcription of DNA sequences into RNA. Regulation at the level of transcription leads to changes in steady-state concentrations of RNA transcripts, affecting the flux of downstream functions and ultimately cellular phenotypes. Changes in transcript levels are routinely followed in cellular contexts via genome-wide sequencing techniques. However, in vitro mechanistic studies of transcription have lagged with respect to throughput. Here, we describe the use of a real-time, fluorescent-aptamer-based method to quantitate steady-state transcription rates of the Mycobacterium tuberculosis RNA polymerase. We present clear controls to show that the assay specifically reports on promoter-dependent, full-length RNA transcription rates that are in good agreement with the kinetics determined by gel-resolved, α-32P NTP incorporation experiments. We illustrate how the time-dependent changes in fluorescence can be used to measure regulatory effects of nucleotide concentrations and identity, RNAP and DNA concentrations, transcription factors, and antibiotics. Our data showcase the ability to easily perform hundreds of parallel steady-state measurements across varying conditions with high precision and reproducibility to facilitate the study of the molecular mechanisms of bacterial transcription.

Estimation of measurement uncertainty for the determination of loss on drying of biologicals

Scientific relevance. GOST ISO/IEC 17025-2019 requires testing laboratories to evaluate the measurement uncertainty of their results. Estimating the uncertainty of analytical methods intended for biologicals is a challenging task that requires time, effort, and a special approach. Measurement uncertainty estimation is of particular interest in the case of measuring loss on drying (LOD) for biologicals, since LOD testing procedures involve analysing measurements of a physical value, i.e. mass.Aim. This study aimed to estimate the measurement uncertainty of LOD determination in biological medicinal products.Materials and methods. The study examined a powdered active substance intended for a Bifidobacterium product (test sample). The authors conducted the LOD test in accordance with the State Pharmacopoeia of the Russian Federation (OFS.1.2.1.0010.15). Statistical processing of the results was performed using Microsoft Excel. To estimate the measurement uncertainty, the authors employed the bottom-up approach or used the standard deviation from testing results.Results. The authors identified the uncertainty components that affected the LOD determination results. When calculated using the bottom-up approach, the expanded uncertainty was 0.34% (coverage factor, k=2; approximate confidence level, 95%). In particular, the largest contributor to the expanded uncertainty was the uncertainty of measuring the mass of weighing bottles containing dried test samples (0.147%), whereas the smallest contributor was the uncertainty of weighing empty bottles (0.003%). When calculated using the standard deviation, the uncertainty of two parallel measurements amounted to 0.32%.Conclusions. Both approaches to calculating LOD measurement uncertainty yield comparable results. According to the uncertainty budget analysis, the uncertainty of measuring the mass of weighing bottles with dried test samples is the major contributor to the test result. For this reason, the conditions of sample preparation should be carefully controlled. The study results confirm that the LOD measurement uncertainty can be calculated using the standard deviation. Testing laboratory teams may benefit from the methods for identifying the factors influencing LOD test results and the methods for calculating the uncertainty of measurement described in this study.

The one-way ANOVA test explained.

Quantitative methods and statistical analysis are essential tools in nursing research, as they support researchers testing phenomena, illustrate their findings clearly and accurately, and provide explanation or generalisation of the phenomenon being investigated. The most popular inferential statistics test is the one-way analysis of variance (ANOVA), as it is the test designated for comparing the means of a study's target groups to identify if they are statistically different to the others. However, the nursing literature has identified that statistical tests are not being used correctly and findings are being reported incorrectly. To present and explain the one-way ANOVA. The article presents the purpose of inferential statistics and explains one-way ANOVA. It uses relevant examples to examine the steps needed to successfully apply the one-way ANOVA. The authors also provide recommendations for other statistical tests and measurements in parallel to one-way ANOVA. Nurses need to develop their understanding and knowledge of statistical methods, to engage in research and evidence-based practice. This article enhances the understanding and application of one-way ANOVAs by nursing students, novice researchers, nurses and those engaged in academic studies. Nurses, nursing students and nurse researchers need to familiarise themselves with statistical terminology and develop their understanding of statistical concepts, to support evidence-based, quality, safe care.

Immunoaffinity LC-MS/MS Quantification of the Sepsis Biomarker Procalcitonin Using Magnetic- and Polystyrene-Bead Immobilized Polyclonal Antibodies.

Procalcitonin (PCT) is a biomarker for bacterial sepsis, and accurate quantification of PCT is critical for sepsis diagnosis and treatment. Immunological PCT quantification methods are routinely used in clinical laboratories, yet there is a need for harmonization of PCT quantification protocols. An orthogonal method to clinical immunological assays, such as LC-MS/MS, is required. In this study, a highly sensitive and robust immunoaffinity LC-MRM quantitative method for detecting procalcitonin in human serum has been developed. An initial comparison of immunocapture of PCT with a polyclonal anti-PCT antibody immobilized on polystyrene nanoparticles (Latex) and magnetic beads demonstrated superior performance with magnetic beads. Three tryptic PCT peptides from the N- and C-terminal regions of PCT were selected for LC-MS/MS quantification. For PCT quantification, an LLOQ of 0.25 ng/mL of PCT in human serum was achieved using a sample volume of 1 mL. The method's trueness and precision consistently lie within the 15% margin. The parallel measurement of three PCT peptides may allow future differentiation of intact PCT vs other PCT forms originating from potential degradation, processing, or polymorphisms. An established and validated LC-MRM-based quantification of PCT will be relevant as an orthogonal method for harmonization and standardization of clinical assays for PCT.

NMR chemical shift prediction and structural elucidation of linker-containing oligo- and polysaccharides using the computer program CASPER

Carbohydrate structures containing alkyl groups as aglycones are useful for investigating enzyme activity and glycan-protein interactions. Moreover, linker-containing oligosaccharides with a spacer group are commonly used to print glycan microarrays or to prepare protein-conjugates as vaccine candidates. The structural accuracy of these synthesized glycans are essential for interpretation of results from biological experiments in which the compounds have been used and NMR spectroscopy can unravel and confirm their structures. An approach for efficient 1H and 13C NMR chemical shift assignments employed a parallel NOAH-10 measurement followed by NMR spin-simulation to refine the 1H NMR chemical shifts, as exemplified for a disaccharide with an azidoethyl group as an aglycone, the NMR chemical shifts of which have been used to enhance the quality of CASPER (http://www.casper.organ.su.se/casper/). The CASPER program has been further developed to aid characterization of linker-containing oligo- and polysaccharides, either by chemical shift prediction for comparison to experimental NMR data or as structural investigation of synthesized glycans based on acquired unassigned NMR data. The ability of CASPER to elucidate structures of linker-containing oligosaccharides is demonstrated and comparisons to assigned or unassigned NMR data show the utility of CASPER in supporting a proposed oligosaccharide structure. Prediction of NMR chemical shifts of an oligosaccharide, corresponding to the repeating unit of an O-antigen polysaccharide, having a linker as an aglycone and a non-natural substituent derivative thereof are presented to exemplify the diversity of structures handled. Furthermore, NMR chemical shift predictions of synthesized polysaccharides, corresponding to bacterial polysaccharides, containing a linker are described showing that in addition to oligosaccharide structures also polysaccharide structures having an aglycone spacer group can be analyzed by CASPER.

BAALC-Expressing Leukemia Hematopoietic Stem Cells and Their Place in the Study of CBF-Positive Acute Myeloid Leukemias in Children and Adults

Background. Due to changing views on pathogenesis, risk factors and therapy strategies in prognostically favorable CBF-positive acute myeloid leukemias[1] (AML), the expression monitoring of RUNX1/RUNX1T1 or CBFB/MYH11 fusion genes, as an additional evaluation of treatment outcomes, appears to be insufficient. This indicates the need to improve the monitoring of the CBF+ AML course by means of parallel measurements of BAALC expression levels which roughly correlate with the mass of BAALC-expressing leukemia hematopoietic stem cells (BAALC-e LHSC).
 Aim. To improve the quality of assessing treatment outcomes with due account for expression levels of RUNX1/RUNX1T1 or CBFB/MYH11 fusion genes and the mass of BAALC-e LHSC and on this basis to pave the way for personalized CBF+ AML treatment.
 Materials & Methods. This study enrolled 39 adult patients aged 20–81 years (median 32 years) and 8 children aged 2–18 years (median 12 years). Among them there were 20 females and 27 males. AML with inv(16)(p13;q22)/t(16;16) was identified in 19 patients, t(8;21)(q22;q22) was detected in 28 patients. BAALC, WT1, RUNX1/RUNX1T1, CBFB/MYH11 expression levels were measured by quantitative real-time PCR and related to the expression of the ABL1 expert gene.
 Results. In 23 patients, inv(16) and t(8;21) appeared to be isolated. Additional multidirectional chromosomal changes were observed in 24 patients with inv(16) and in 18 patients with t(8;21). All enrolled patients showed increased BAALC expression. In the course of therapy, it was decreasing to the threshold value in 16/18 (89 %) patients. The evaluation of the mean BAALC expression levels in the pooled groups of children and adults with isolated findings of either inv(16) or t(8;21) showed the decrease of the BAALC-e LHSC mass only in children (p = 0.049). The comparison of the mean WT1 expression levels in the pooled groups of children and adults with isolated and additional chromosomal abnormalities revealed their significant decrease in patients with complicated variants (p = 0.023).
 Conclusion. The case reports provided in this paper show that the molecular monitoring with serial measurements of fusion genes and BAALC gene expression levels in CBF+ AML patients can lay the basis for further improvement of personalized treatment strategies for these patients. In all likelihood, parallel measurements of the above gene expression levels will allow to establish the framework for decision-making concerning treatment extent and timely HSC transplantation.