Atomic Mass Units Research Articles

Detection of lunar water, hydroxyl ion and their diurnal changes from CHACE-2 orbiter observation

This work reports the spatial and diurnal variations of the number densities of lunar molecular water (H2O), atomic mass unit (amu) 18 and hydroxyl (OH), amu 17 over low (0° to 30°), middle (31° to 60°) and high (61° to 80°) latitudinal regions of the lunar exosphere during the pre-sunrise, noon, sunset and midnight periods using the mass spectrometric data of CHandra's Atmospheric Composition Explorer-2 (CHACE-2) on board Chandrayaan-2, the second lunar mission developed in India. Both H2O and OH exhibit, particularly in the low latitude regions, a trend of increasing number density after the sunrise and up to noon, followed by a decrease till sunset. An overall higher density of H2O is obtained compared to the previous reports. The findings are justified in terms of the polar orbital height of the instrument and the duration of data procurement. The maximum number density for the low, middle and high latitudes reaches 5225 cm−3, 5135 cm−3 and 3747 cm−3, respectively. The corresponding OH abundances are found to be 5079 cm−3, 5565 cm−3 and 5720 cm−3. The diurnal variations of H2O and OH and their comparisons, similar to those of the present report may provide suitable means for tracing the lunar water cycle. The CHACE-2 observations imply that the influence of magnetotail passage on volatiles like water is to be further quantified in future missions with other sensors.

Novel differential pumping system with extended sampling range: Design and application in the EAST tokamak

A novel differential pumping system (DPS) with an adjustable sampling rate has been developed and implemented in the Experimental Advanced Superconducting Tokamak (EAST). This system is equipped with a high-resolution quadrupole mass spectrometer (QMS), covering a mass range of 1–16 atomic mass units (AMU), alongside a conventional QMS with a broader range of 1–200 AMU. The DPS features a dynamic pressure sampling capability from 10−2 to 105 Pa, utilizing a gas dosing valve and an angle valve, enabling a wide gas sampling ratio range of 10−9 to 3 × 10−2. The high-resolution QMS (QMG700) is adept at directly quantifying the partial pressures of deuterium and helium within mixtures, while the conventional QMS (RGA200) offers indirect measurement of D2 partial pressures above 2 × 10−5 Pa, complemented by direct wide-range mass analysis. During the EAST tokamak campaigns of 2023 and 2024, the DPS was effectively utilized for glow discharge cleaning (GDC) at a pressure of 3 Pa and ion cyclotron wall conditioning (ICWC) at approximately 3 × 10−3 Pa, accurately distinguishing deuterium pressure from the helium environment in the wide pressure range of vacuum vessel. Moreover, the DPS was successfully employed to trace the vacuum leak location in EAST campaign with a pressure of up to hundreds Pa. This DPS is a key tool for gas ingredient analysis and leak detection in the EAST campaigns, providing a valuable reference for the vacuum operation of future fusion reactors.

Discontinuous Atmospheric Pressure Interface in-Trap Single Photon Ionization Ion Trap Mass Spectrometry (DAPI in-Trap SPI ITMS)

A compact in-trap single photon ionization (SPI) system, termed discontinuous atmospheric pressure interface (DAPI) ion trap mass spectrometry (ITMS), for the rapid determination of trace volatile organic compounds (VOCs). DAPI enables the maintenance of high analyte pressure in the SPI source while preserving the vacuum. Utilizing vacuum ultraviolet (VUV) lamp as the ion source, we ionize the analyte within an enclosed miniature 3D ion trap for efficient analysis. Experimental findings demonstrate that the system achieves a mass resolution of less than 0.5 atomic mass units for full width at half maxima (FWHM), providing unit resolution. For the response for benzene, the system achieves almost instantaneous response, with rise and fall times of only 2 s, which is a significant advantage compared to the membrane inlet (MI) approach necessary for on-site detection. Additionally, tandem mass spectrometry (MS/MS) with unit m/z isolation window was achieved and resolved dimethyl disulfide and phenol with similar molecular weights. Our results demonstrate that the system provides excellent performance and we anticipate its application in rapidly determining VOCs.

Commissioning of the ERDA-TOF beamline at the ion beam laboratory in Madrid

We report progress for the ERDA time-of-flight beamline at the Centre of Micro-Analysis of Materials in Madrid. This beamline experienced a long shut down and has recently gone through a re-commissioning process. The time stations, based on a twin mirror design, demonstrate a time resolution of 215 ps for 6 MeV He2+. Using a standard particle detector for the energy signal we find a mass resolution of 1.4 atomic mass units for 27Al and 28Si with 40 MeV Cl4+. Detection efficiency needs no corrections for elements heavier than 7Li. Analysis of a borosilicate reference showed good agreement with the known composition. Based on these results, the facility is considered operational and open for users.

Application of a New Mass-Energy Concept in the Computation of Atomic Nuclear Masses

In most literatures and scientific extrapolations, the Bethe-Weizsacker’s mass formula is dependent on Einstein’s relativistic mass-energy theory for calculations of nuclear masses, but the relativistic energy converting factor (speed of light) is only attributed to massless particle. Therefore, the method employed involves the conversion of the binding energy fitting coefficients by krane from mega electron volt to unified atomic mass unit (u) using Einstein relativistic mass-energy theory, Bahjat mass-energy relation and our new mass-energy concept. A close correlation can be observed between the calculated masses of light, medium and heavy nuclei using the relativistic mass-energy theory (mc2), our new mass energy concept (mvc) and the experimentally measured mass. The Bahjat mass-energy relation (mbc) is underestimated compared to our new mass energy concept. Therefore, any particle with mass greater than zero would travel with speed less than the speed of light. Hence the relation, E = mc2, needs to be modified. It would therefore be more precise to apply the mass energy concept, E = mvc, for a mass particle. This is the reason why the Beth-Weizsacker’s semi empirical mass formula shows a closer result to the experimental results, for masses of nuclei, when computation is done with our new mass -energy concept.

A multi-reflection time-of-flight setup for the study of atomic clusters produced by magnetron sputtering

The Greifswald multi-reflection time-of-flight setup has been extended with a magnetron sputtering gas aggregation source for the production of atomic cluster ions with sizes ranging from a single to thousands of atoms. This source, combined with a newly added quadrupole mass filter and a linear Paul trap, opens up the possibility of many new atomic-cluster studies not feasible with the setup before. The new components and their interfacing with the previous setup are described, and benchmarking as well as the first experimental results are presented. The capability of the system to handle singly charged ions with masses of several ten thousand atomic mass units is demonstrated.

Fast quantum interference of a nanoparticle via optical potential control

We introduce and theoretically analyze a scheme to prepare and detect non-Gaussian quantum states of an optically levitated particle via the interaction with light pulses that generate cubic and inverted potentials. We show that this approach allows to operate on sufficiently short time- and length scales to beat decoherence in a regime accessible in state-of-the-art experiments. Specifically, we predict the observation of single-particle interference of a nanoparticle with a mass above 108 atomic mass units delocalized by several nanometers, on timescales of milliseconds. The proposed experiment uses only optical and electrostatic control, and can be performed at about 10-10 mbar and at room temperature. We discuss the prospect of this method for coherently splitting the wavepacket of massive dielectric objects without using either projective measurements or an internal level structure.

High-Precision Determination of g Factors and Masses of ^{20}Ne^{9+} and ^{22}Ne^{9+}.

We present the measurements of individual bound electron g factors of ^{20}Ne^{9+} and ^{22}Ne^{9+} on the relative level of 0.1 parts per billion. The comparison with theory represents the most stringent test of bound-state QED in strong electric fields. A dedicated mass measurement results in m(^{20}Ne)=19.992 440 168 77(9) u, which improves the current literature value by a factor of 18, disagrees by 4 standard deviations, and represents the most precisely measured mass value in atomic mass units. Together, these measurements yield an electron mass on the relative level of 0.1ppb with m_{e}=5.485 799 090 99(59)×10^{-4} u as well as a factor of seven improved m(^{22}Ne)=21.991 385 098 2(26) u.

Micromachined Mechanical Resonant Sensors: From Materials, Structural Designs to Applications

AbstractDriving a micro and nanomechanical structure to resonance and observing its resonant motion in the physical world have led to numerous fundamental discoveries in physics, sciences, chemistry, biology, and engineering, as well as device commercialization. Scaling down mechanical structures from micrometric to nanometric size has enabled the utilization of resonant motions to probe material properties and various dynamical phenomena in quantum coherence and squeezing. Recent advances in material sciences and nanofabrication resulted in successful demonstration of ultra‐high frequency operation (GHz range) and ultra‐high quality factor (10 billion) micromachined mechanical resonators (MMRs). The resonant motion of these structures has been utilized as an indispensable tool to weigh biological and chemical species at resolution of atomic mass unit, sense a force as small as zepto‐newton, and to detect numerous other physical parameters. Here, a systematic view on the resonant sensing transduction is provided, underlying physics, and sensing structures realized with micro/nano‐electromechanical systems (MEMS/NEMS) technologies. It is also describe the roles of nanomaterials and structures, nano‐fabrication and rational designs on the resonance frequency and quality factor of MMRs toward high‐performance sensing. This paper discusses the most recent advances in the development of MMRs for material characterization as well as biological, chemical, and physical sensing. Finally, the paper discusses the challenges and perspectives on design, fabrication, and developments of resonant sensors with high quality factor toward quantum sensing, and ultra‐high sensitivity and resolution for classical sensing applications.

Atypical N-Alkyl to N-Noralkoxy Switch in a Dual cSRC/BCR-ABL1 Kinase Inhibitor Improves Drug Efflux and hERG Affinity.

We describe an atypical amine bioisostere, the trisubstituted hydroxylamine, that upon incorporation into an approved dual cSRC/BCR-ABL1 kinase inhibitor yields 9, a compound that retains potent biological activity and couples it with improved drug efflux and hERG affinity at the expense of only a 2 atomic mass unit increase in molecular weight. Contrary to the common expectation for hydroxylamines in medicinal chemistry, 9 is well tolerated in vivo and lacks the mutagenicity and genotoxicity so often ascribed to lesser substituted hydroxylamines. A matched molecular pair (MMP) analysis suggests that the beneficial properties conferred by the N-alkyl to N-noralkoxy switch arises from a reduction in basicity of the piperazine unit. Overall, these results lend additional support to the use of trisubstituted hydroxylamines as bioisosteres of N-alkyl groups that are not involved in key polar interactions.

Laboratory study of the PFRC-2's initial plasma densification stages

Initial plasma densification by odd-parity rotating magnetic fields (RMFo) applied to the linear magnetized Princeton field-reversed configuration (PFRC-2) device with fill gases at pressures near 1 mTorr proceeds through two phases: a slow one, characterized by a rise time τslow∼100μs, followed by a fast one, characterized by τfast∼10μs. The transition from slow to fast occurs at a line-integral-averaged electron density, tne, near 2×1011 cm−3, independent of magnetic field. Over most of the range of experimental parameters investigated, as the PFRC-2 axial magnetic field strength was increased, RMFo power decreased, gas fill pressure lowered, or lower atomic mass unit (AMU) fill gas used, the duration of the slow phase lengthened from 50 μs to longer than 10 ms after the RMFo power began. The post-fast-phase maximum ne increases with the fill-gas AMU, exceeding 5 × 1013 cm−3 for Ar. The slow phase is consistent with atomic physics processes and field-parallel sound-speed losses. The fast phase may be explained by improved axial confinement, possibly augmented by radial or axial contraction of the plasma. Another possible explanation, a large increase in electron temperature, is inconsistent with x-ray emission. The ne behavior is discussed in relation to the E to H transition.

Green hydrogen as an environmentally-friendly power source

Hydrogen is the most plentiful chemical element in the visible universe. The mass composition of the visible universe is approximately 74% hydrogen, 24% helium, 1% oxygen, and the rest of all other chemical elements is about 1%. Hydrogen has the symbol H and the atomic number 1. It is placed in the first position in Mendeleev's periodic table of elements, in the upper left corner. It is an easily flammable, colorless, tasteless, odorless gas, and in nature, it is found mainly in the form of the diatomic molecule, H 2. With an atomic mass unit of 1.00794, hydrogen is the lightest chemical element. Etymologically, the word hydrogen is a combination of two Greek words hydor and gennan meaning: water producer. Hydrogen (H 2) has a very good calorific value per mass unit 143 MJ/kg which is 3.33 times more than the calorific value of kerosene or diesel fuel. Green hydrogen (clean hydrogen or renewable hydrogen) is produced by electrolysis of water (splitting of water into hydrogen and oxygen) using electricity from renewable sources such as solar energy, wind energy, seawater waves energy, or tidal power. Green hydrogen is an environmentally-friendly power source (no harmful gases). This paper presents recent documentary research by the authors on green hydrogen as an environmentally-friendly power source: for space rocket launches and for hydrogen fuel cells used in the space shuttle as electrical power generators and drinking water generators from launch to return from the space mission; as fuel for a modified turboprop engine (Rolls-Royce and easyJet); as fuel for the European Destinus aircraft using the Jungfrau technology system for a planned hypersonic aircraft using a modified commercial afterburning engine; as fuel for modified gas turbine engines and hydrogen fuel cells to supply electrical power to supplement the gas turbine for the Airbus ZEROe aircraft, etc.

Quantification of Hydride Coverage on Cu(111) by Electrochemical Mass Spectrometry.

Electrochemical mass spectrometry (EC-MS) is combined with chronoamperometry to quantify H coverage associated with the surface hydride phase on Cu(111) in 0.1 mol/L H2SO4. A two-step potential pulse program is used to examine anion desorption and hydride formation, and the inverse, by tracking the 2 atomic mass unit (amu) signal for H2 production in comparison to the charge passed. On the negative potential step, the reduction current is partitioned between anion desorption, hydride formation, and the hydrogen evolution reaction (HER). For modest overpotentials, variations in partial processes are evident as inflections in the chronoamperometry and EC-MS signal. On the return step to positive potentials, hydride decomposition by H recombination to H2 occurs in parallel with sulfate adsorption. The challenge associated with the inherent diffusional delay in the EC-MS response is mitigated by total H2 collection and steady-state analysis facilitated by the thin-layer EC-MS cell geometry as demonstrated for the HER on a non-hydride forming Ag electrode. Analysis of the respective transients and steady-state response on Cu(111) reveals a saturated hydride fractional coverage of 0.67 at negative potentials with an upper bound charge of 106 μC/cm2 (average electrosorption valency of ≈1.76) associated with adsorption of the () mixed sulfate-water adlayer at positive potentials.

Gas isotope thermometry in the South Pole and Dome Fuji ice cores provides evidence for seasonal rectification of ice core gas records

Abstract. Gas isotope thermometry using the isotopes of molecular nitrogen and argon has been used extensively to reconstruct past surface temperature change from Greenland ice cores. The gas isotope ratios δ15N and δ40Ar in the ice core are each set by the amount of gravitational and thermal fractionation in the firn. The gravitational component of fractionation is proportional to the firn thickness, and the thermal component is proportional to the temperature difference between the top and bottom of the firn column, which can be related to surface temperature change. Compared to Greenland, Antarctic climate change is typically more gradual and smaller in magnitude, which results in smaller thermal fractionation signals that are harder to detect. This has hampered application of gas isotope thermometry to Antarctic ice cores. Here, we present an analytical method for measuring δ15N and δ40Ar with a precision of 0.002 ‰ per atomic mass unit, a two-fold improvement on previous work. This allows us to reconstruct changes in firn thickness and temperature difference at the South Pole between 30 and 5 kyr BP. We find that variability in firn thickness is controlled in part by changes in snow accumulation rate, which is, in turn, influenced strongly by the along-flowline topography upstream of the ice core site. Variability in our firn temperature difference record cannot be explained by annual-mean processes. We therefore propose that the ice core gas isotopes contain a seasonal bias due to rectification of seasonal signals in the upper firn. The strength of the rectification also appears to be linked to fluctuations in the upstream topography. As further evidence for the existence of rectification, we present new data from the Dome Fuji ice core that are also consistent with a seasonal bias throughout the Holocene. Our findings have important implications for the interpretation of ice core gas records. For example, we show that the effects of upstream topography on ice core records can be significant at flank sites like the South Pole – they are responsible for some of the largest signals in our record. Presumably upstream signals impact other flank-flow ice cores such as EDML, Vostok, and EGRIP similarly. Additionally, future work is required to confirm the existence of seasonal rectification in polar firn, to determine how spatially and temporally widespread rectifier effects are, and to incorporate the relevant physics into firn air models.

Determination of Diffusion Coefficient of Palm Oil in n-Hexane Using Laser Deflection Method and Image Processing

Determination of diffusion coefficient using the Wiener method has shown a high level of agreement with literature in previous studies, particularly for liquids with a mass of less than hundreds of amu and a small molecule-sized order of Angstrom (atomic mass unit). This method involves a laser beam deflection and refraction phenomenon on the inter-diffusion zone of two fluids with different refractive indexes. Palm oil, vegetable oil with a composition and structure that is quite complicated and size relatively large molecule, has abundantly available and has become one of the primary raw materials for biodiesel production and cooking. This study used the method to examine the diffusivity of palm oil in n-hexane, which is still rare and hard to find, so challenging to be studied. A camera is used to catch the trace of a deflected laser beam on a screen after it passes through a diffusion cell in the measurement. This image was then corrected, made grey, and digitized to extract the laser image coordinate data. An averaging window algorithm is used in digitizing. The digitized results are then processed to calculate the diffusion coefficient. Measurements were made three times to test the consistency of the results. Camera and digitizing techniques are used here to speed up and facilitate measurement. The measured value of diffusion coefficient of palm oil in n-hexane is 2.18×10-4 ± 5.05×10-5 cm2/minute. The results showed consistency in measure, i.e., precision with a maximum error range of 10.6%, but not good suitability value with literature data, i.e., accuracy was less than 10%. These results found that the measurement system that applied the laser deflection method and the image processing of averaging window could not measure the diffusion coefficient of large molecules and complexes such as palm oil quite well.

Quantum thermodynamics of hydrogen in nano-structured materials—H2 in carbon nanotubes

Abstract Modern quantum theory of correlations predicts, and reveals, new counter-intuitive dynamical effects of hydrogen in nano-structured materials, being of considerable importance for basic research as well as for technological applications. To support this claim, here the focus is on H2 molecules in carbon nanotubes and other nanocavities, as experimentally investigated with the well established technique of incoherent inelastic neutron scattering (INS). In particular, the experimentally determined momentum and energy transfers from an H2 molecule in a carbon (C-) nanotube resulting in roto-translational motion along the nanotube axis, appear to (1) either violate the standard conservations laws, or (2) attribute the translating H2 molecule a highly reduced inertia, as quantified by the effective mass M eff ≈ 0.64 a.m.u. (atomic mass units), instead of 2 a.m.u. for an isolated molecule. This counter-intuitive INS-observation has no conventional interpretation, but it can be qualitatively interpreted “from first principles” in the frame of modern theories of quantumness of correlations and Quantum Thermodynamics (QTD). This analysis also provides a surprising new physical insight: The nano-structured cavities do represent quantum systems which contribute to the quantum dynamics of the hydrogen translational dynamics, and thus to the hydrogen transport in the studied materials. This insight may also have far-reaching consequences for technological applications and material sciences (e.g. fuel cells, H storage materials, etc.), since it concerns the choice and design of “optimized” materials adsorbing or carrying hydrogen.

A Power Sequence Interaction Function for Liquid Phase Particles

In this manuscript, a function is derived that allows the interactions between the atoms/molecules in nanoparticles, nanodrops, and macroscopic liquid phases to be modeled. One goal of molecular theories is the development of expressions to predict specific physical properties of liquids for which no experimental data are available. A big limitation of reliable applications of known expressions is that they are based on the interactions between pairs of molecules. There is no reason to suppose that the energy of interaction of three or more molecules is the sum of the pairwise interaction energies alone. Here, an interaction function with the limit value w = e2π/e is presented, which allows for the derivation of the atomic mass unit and acts as a bridge between properties of elementary particles and emergent properties of macroscopic systems. The following properties of liquids are presented using the introduced interaction function: melting temperatures of n-alkanes, nanocrystals of polyethylene, melting temperatures of metal nanoparticles, solid–liquid phase transition temperatures for water in nanopores, critical temperatures and critical pressures of n-alkanes, vapor pressures in liquids and liquid droplets, self-diffusion coefficients of compounds in liquids, binary liquid diffusion coefficients, diffusion coefficients in liquids at infinite dilution, diffusion in polymers, and viscosities in liquids.

Capillary ionic liquid electrospray: beam compositional analysis by orthogonal time-of-flight mass spectrometry

Orthogonal time-of-flight mass spectrometry has been used to characterize the kinetic energy and charged species distributions from an in vacuo electrospray ion source for four different ionic liquids at volumetric flow rates between 0.3 and 3.3 nanolitres per second. In all cases, the mass spectra revealed charged species consisting of singly charged and multiply charged ions as well as two broad, unresolved droplet distributions occurring in the 104 to 106 atomic mass unit per charge range. The mean jet velocity and mean jet breakup potential were established from analysis of the energy profile of the high mass-to-charge droplets. At the jet breakup point, we find the energy loss and the jet diameter flow rate dependence of the electrospray beam to be similar to that determined by Gamero-Castaño (Phys. Fluids, vol. 20, 2008, 032103; Phys. Rev. Fluids, vol. 8, 2021, 013701) for 1-ethyl-3-methylimidazolium bis(trifluromethylsulfonyl)imide at similar volumetric flow rates. Similar trends are observed for all four liquids over the flow regime. A jet instability analysis revealed that jet electrification and viscous effects drive the jet breakup from the case of an uncharged, inviscid jet; jet breakup occurs at droplet and jet radius ratios that deviate from 1.89. Using the analytically determined ratio and the beam profile, different species are modelled to reconstruct the mass spectra; primary droplets constitute only a fraction of the total species present. The populations of the species are discussed.

Development of technology for production of functional fruit drinks

The object of research is the technology of functional fruit and vegetable juice products enriched with collagen. The subject of research is various types of collagen, formulations and parameters of technological operations for the production of functional juice drinks. The research is aimed at the develop technology, recipes for a new assortment of fruit and vegetable drinks enriched with collagen. Also it is aimed at the preserve the functional properties of collagen in canned juice products after high-temperature processing and create food products for everyday consumption to solve age-related and other problems associated with human health. In the course of the study, standard methods were used to determine the organoleptic indicators of various types of collagen, juice products, as well as to determine the mass fraction of moisture, carbohydrates, fats, proteins in the developed fruit and vegetable drinks enriched with collagen. Also, to confirm the presence and preservation of collagen in finished products, the electrophoresis method was used to determine the atomic mass unit of the constituent substances after complete drying of the samples. The proposed methods make it possible to assess the quality of the developed collagen-enriched drinks, prove the presence and preservation of a biologically active additive in the finished product after using the sterilization mode parameters – temperature and time, when receiving canned products. The developed formulations and technology make it possible to consider functional fruit and vegetable juice-containing products enriched with a biologically active additive collagen as effective and useful. An easily digestible food product for everyday consumption is proposed for solving age-related and other problems related to human health, with regulation of the pH value for effective use of the beneficial properties of this additive. In contrast to existing functional juice products, the proposed formulations and technology make it possible to obtain juice-containing fruit and vegetable blended products with a biologically active additive collagen. The technology minimizes the impact of collagen on the organoleptic characteristics of the developed recipe compositions of finished products and preserves its beneficial biologically active properties in the finished canned product after heat sterilization.

Plasma LRG1 Protein Are Overexpressed in Acute Myeloid Leukemia with High Sensitivity and High Specificity in Differentiating Leukemic Plasma from Normal Plasma — a Potential Biomarker for Minimal Residual Disease Detection

Background:Acute myeloid leukemia (AML) is a heterogenous disease with variable outcome depending on cytogenetic as well as molecular risk at presentation. 70-80% of AML patients would achieve complete remission after induction chemotherapy. However, more than half would suffer a relapse. Currently there is no specific test available in clinical practice to detect early relapse. Relapse is usually suspected when there is a change in peripheral blood count or rising LDH. This often proven to be a frank relapse disease by bone marrow examination. A sensitive and specific biomarker in plasma to detect early disease relapse is not available. In this study, we aimed to identify a new biomarker in AML plasma that could potentially be used in clinical practice for detection of early disease relapse.Method:Plasma samples were obtained from 8 newly diagnosed AML patients. Patients with fever, renal impairment, heart failure, and abnormal liver function test were excluded to reduce background noise in proteomic analysis. These 8 samples were than matched with 8 normal blood donors plasma that were age and gender matched. Plasma samples would be processed for iTRAQ (isobaric tagging for relative and absolute quantification) and analysed. 1 mL of plasma sample would be delipidated and 7 of the most abundant proteins removed using the MARS Hu-7 affinity column (Agilent Technologies, USA) to prevent the masking of low abundance proteins. Samples comprising 100mg of proteins were then reduced, alkylated, digested and labeled with iTRAQ reagents that differ by 1 atomic mass unit. Protein identification and relative quantification with statistical analysis are performed using in-house QSTAR Elite Q-TOF LC/MS/MS mass spectrometer coupled with ProteinPilotTM software (version 2.1). Proteins that were overexpressed in AML patients, which has potential relation with leukemogenesis would be shortlisted and further quantified in 42 other AML patients and 40 normal blood donor plasma for validation. Correlation with clinical data were carried out.Results:13 proteins were found to be overexpressed in all 8 AML samples with an average expression ratio ranging from 1.75 to 4.50 (see figure 1). Two proteins were shortlisted for its relation with haematopoietic cell - Brain acid soluble protein 1 (BASP1) and Leucine-rich alpha-2-glycoprotein (LRG1). Further validation in normal plasma and AML plasma revealed that BASP1 protein did not have sufficiently good sensitivity and specificity. BASP1 mean concentration in normal plasma was 8.05 ng/mL (SD: 6,29 ng/mL), and in AML samples was 4.41 ng/mL (SD:1.26 ng/mL). In contrast, LRG1 protein showed a significant difference in concentration. LRG1 mean concentration in normal plasma was 2.03 μg/mL (SD: 0.49 μg/mL), compared to AML samples - 13.29 μg/mL (SD: 7.80 μg/mL), p<0.001 (see figure 2). ROC analysis of LRG1 protein for differentiating AML samples from normal plasma sample revealed an AUC of 0.998 (see figure 3), p<0.001. Cut-off level of 3.17 μg/mL would give a sensitivity level of 97.6% (95%CI: 87.4-99.9%), and specificity level of 97.5% (95%CI: 88.8-99.9%). Correlation with clinical data revealed significant correlation with total white cell count at diagnosis, Pearson correlation value of 0.41, p=0.009. In this small cohort of 42 patients, we were unable to demonstrate any correlation of LRG1 with clinical outcome.Conclusion:Plasma LRG1 protein showed a high sensitivity and high specificity in differentiating AML plasma from normal plasma. It also showed a strong correlation with total white cell count in AML patients. Further evaluation of LRG1 protein plasma level in AML patients in longitudinal manner is required to validate its utility in monitoring for minimal residual disease and early detection of leukemic relapse. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.