IMS Technique Research Articles

Evaluation of the effect of dietary supplementation with Allium mongolicum regel bulb powder on the volatile compound and lipid profiles of the longissimus thoracis in Angus calves based on GC–IMS and lipidomic analysis

The effect of A. mongolicum Regel bulb powder (AMRP) supplementation on the flavour of beef from Angus calves has not been investigated thus far. We used GC–IMS and untargeted lipidomics techniques to examine the volatile compound and lipid metabolic profiles and reveal the effects of dietary AMRP supplementation on the flavour of beef. A total of 6 characteristic volatile compounds and 30 key lipid compounds were identified in the AMRP treatment group. AMRP promoted the release of triglycerides and phosphatidylinositols from beef and accelerated the production of volatile compounds such as ethyl acetate, 1-penten-3-one, and tetrahydrofurane, and the production of these three characteristic volatile compounds was significantly correlated with the UFAs in triglycerides according to correlation analysis. In summary, dietary AMRP supplementation had a positive effect on the flavour of beef, and these findings provide a theoretical basis for the development and utilisation of AMRP as a feed additive.

High-resolution ion mobility based on traveling wave structures for lossless ion manipulation resolves hidden lipid features

High-resolution ion mobility (resolving power > 200) coupled with mass spectrometry (MS) is a powerful analytical tool for resolving isobars and isomers in complex samples. High-resolution ion mobility is capable of discerning additional structurally distinct features, which are not observed with conventional resolving power ion mobility (IM, resolving power ~ 50) techniques such as traveling wave IM and drift tube ion mobility (DTIM). DTIM in particular is considered to be the “gold standard” IM technique since collision cross section (CCS) values are directly obtained through a first-principles relationship, whereas traveling wave IM techniques require an additional calibration strategy to determine accurate CCS values. In this study, we aim to evaluate the separation capabilities of a traveling wave ion mobility structures for lossless ion manipulation platform integrated with mass spectrometry analysis (SLIM IM-MS) for both lipid isomer standards and complex lipid samples. A cross-platform investigation of seven subclass-specific lipid extracts examined by both DTIM-MS and SLIM IM-MS showed additional features were observed for all lipid extracts when examined under high resolving power IM conditions, with the number of CCS-aligned features that resolve into additional peaks from DTIM-MS to SLIM IM-MS analysis varying between 5 and 50%, depending on the specific lipid sub-class investigated. Lipid CCS values are obtained from SLIM IM (TW(SLIM)CCS) through a two-step calibration procedure to align these measurements to within 2% average bias to reference values obtained via DTIM (DTCCS). A total of 225 lipid features from seven lipid extracts are subsequently identified in the high resolving power IM analysis by a combination of accurate mass-to-charge, CCS, retention time, and linear mobility-mass correlations to curate a high-resolution IM lipid structural atlas. These results emphasize the high isomeric complexity present in lipidomic samples and underscore the need for multiple analytical stages of separation operated at high resolution.Graphical abstract

SLIM-Based High-Resolution Ion Mobility Reveals New Structural Insights into Isomeric Vitamin D Metabolites and their Isotopologues.

Testing for vitamin D deficiency remains a high-volume clinical assay, much of which is done using mass spectrometry-based methods to alleviate challenges in selectivity associated with immunoassays. Ion mobility-mass spectrometry (IM-MS) has been proposed as a rapid alternative to traditional LC-MS/MS methods, but understanding the structural ensemble that contributes to the ion mobility behavior of this molecular class is critical. Herein we demonstrate the first application of high-resolution Structures for Lossless Ion Manipulations (SLIM) IM separations of several groups of isomeric vitamin D metabolites. Despite previous IM studies of these molecules, the high resolving power of SLIM (Rp ∼ 200) has revealed additional conformations for several of the compounds. The highly similar collision cross sections (CCS), some differing by as little as 0.7%, precluded adequate characterization with low-resolution IM techniques where, in some cases, wider than expected peak widths and/or subtle shoulders may have hinted at their presence. Importantly, these newly resolved peaks often provided a unique mobility that could be used to separate isomers and provides potential for their use in quantification. Lastly, the contribution of isotopic labeling to arrival time distribution for commonly used 13C- and deuterium-labeled internal standards was explored. Minor shifts of ∼0.2-0.3% were observed, and in some instances these shifts were specific to the conformer being measured (i.e., "closed" vs "open"). Accounting for these shifts is important during raw data extraction to ensure reproducible peak area integration, which will be a critical consideration in future quantitative applications.

Antegrade Intramedullary Pinning versus Retrograde Intramedullary Pinning versus Transverse k-Wires Fixation of Neck of 5th Metacarpal Fracture: A Systematic Review

Background The 5th metacarpal fractures accounts for 40% of all hand fractures. Neck fractures are the commonest, as it is the weakest point in metacarpals, and accounts for about 10% of all hand fractures. Improper management of hand fractures has negative economic effect due to disabilities that occur to hands of workers, athletes and housewives. Objective To do a systematic review on literature that compares between using the antegrade verses retrograde intra-medullary k-wires and transverse pinning techniques in treatment of fifth metacarpal's neck fracture (boxer's fracture) regarding union, functional outcome and complications. Patients and Methods Recent clinical trials or cluster trials, prospective and retrospective comparative cohort studies. Search results will be uploaded to systematic review management software and manually screened for eligibility to be included. PRISMA flowchart will be introduced on the search results and the inclusion/exclusion criteria. Results Application of inclusion and exclusion criteria to study abstracts yielded 8 articles. The full-text articles for these 100 studies were then reviewed and subjected to our inclusion criteria. A total of 8 articles were eligible for final systematic review. Data Sources Medline databases (PubMed, Medscape, ScienceDirect. EMF-Portal) and all materials available in the Internet till 2022. Data Extraction If the studies did not fulfill the inclusion criteria, they were excluded. Study quality assessment included whether ethical approval was gained, eligibility criteria specified, appropriate controls, and adequate information and defined assessment measures. Conclusion Despite the limitations of this review, we found some evidence that the IM technique could have advantages over the use of transverse pinning in the treatment for the fifth metacarpal neck fractures. The quantitative analyses indicated probable better efficacy of IM particularly in relation to VAS, TAM, active ROM of the fifth ray and residual angulation. Our results can fit into the context of current practice where many hand surgeons consider the IM technique as their preferred method to treat neck fractures of the fifth metacarpal.

Multiple-Input Multiple-Output Multiple-Mode OFDM With Index Modulation

Multiple-mode orthogonal frequency division multiplexing with index modulation (MM-OFDM-IM) has been proposed as a novel IM technique, which conveys information via the permutation of multiple distinguishable constellations. In this paper, we propose a novel multiple-input multiple-output MM-OFDM-IM (MIMO-MM-OFDM-IM) scheme by combining MM-OFDM-IM and MIMO to take advantage of both techniques collectively. The low complexity detections, such as minimum mean square error (MMSE) Viterbi-like and MMSE subcarrier-wise log-likelihood ratio (MMSE-LLR), are proposed to largely reduce the receiver detection complexity. Besides, the theoretical analyses on bit error rate (BER) is also derived in closed-form to evaluate the performance of MIMO-MM-OFDM-IM. Considering different system configurations, it is shown via Monte Carlo simulations that the proposed MIMO-MM-OFDM-IM scheme not only achieves higher SE but also provides better error performance than the conventional schemes.

A review on ion mobility mass spectrometry

Mass Spectrometry can be coupled with ion mobility to get results that cannot be obtained by alone mass spectrometry. This coupled instrument can be used for knowing the separation of isomers, isobars, and conformers, the reduction of chemical noise, and the measurement of ion size. It divides ions into families of ions as well as ions with the same charge and similar structural properties. The four ion mobility separation techniques currently applied to mass spectrometry are described in this article. Low-resolution mobility separation is demonstrated by AIMS. Offering continuous ion monitorings are DMS and FAIMS. TWIMS is a novel IMS technique that has good sensitivity and is well integrated into a commercial mass spectrometer while having modest resolving power. In this review it includes that Many researches has used this technique has it gives results in millisecond and its low cost operation.it has major drawback of contamination of compounds due to atmospheric pressure, complex spectra and interferences aredue to wide spread of ionization.it is not suitable for Non-volatile compound and the repoducubility is1-2%.

Cyclic Ion Mobility-Collision Activation Experiments Elucidate Protein Behavior in the Gas Phase.

Ion mobility coupled to mass spectrometry (IM-MS) is widely used to study protein dynamics and structure in the gas phase. Increasing the energy with which the protein ions are introduced to the IM cell can induce them to unfold, providing information on the comparative energetics of unfolding between different proteoforms. Recently, a high-resolution cyclic IM-mass spectrometer (cIM-MS) was introduced, allowing multiple, consecutive tandem IM experiments (IMn) to be carried out. We describe a tandem IM technique for defining detailed protein unfolding pathways and the dynamics of disordered proteins. The method involves multiple rounds of IM separation and collision activation (CA): IM-CA-IM and CA-IM-CA-IM. Here, we explore its application to studies of a model protein, cytochrome C, and dimeric human islet amyloid polypeptide (hIAPP), a cytotoxic and amyloidogenic peptide involved in type II diabetes. In agreement with prior work using single stage IM-MS, several unfolding events are observed for cytochrome C. IMn-MS experiments also show evidence of interconversion between compact and extended structures. IMn-MS data for hIAPP shows interconversion prior to dissociation, suggesting that the certain conformations have low energy barriers between them and transition between compact and extended forms.

Generalization of Index-Modulation: Breaking the Conventional Limits on Spectral and Energy Efficiencies

In the context of orthogonal frequency-division multiplexing with index modulation (OFDM-IM), this paper first presents an improved index modulation (IIM) technique to address the well-known low spectral efficiency problem of IM techniques in general and OFDM-IM in particular. OFDM-IIM is realized by deriving the minimum required number of subcarriers per group, and the minimum number of active subcarriers in each group, of the conventional OFDM-IM technique. It is proven that OFDM-IIM can deliver higher spectral and energy efficiencies than classical OFDM and OFDM-IM. The gains come at the expense of increased detection complexity. Therefore, a proposal of OFDM with generalized IM (OFDM-GIM) technique is presented, where a variable number of subcarriers per group are allowed to be activated. Two variants of OFDM-GIM are designed based on the activation pattern of the subcarriers: the first achieves superior spectral efficiency with reduced detection complexity as compared to OFDM-IIM, and the second is tailored for low data rate communications with higher energy efficiency requirements. Besides optimal maximum likelihood detection, a less-complex sub-optimal detector is proposed. A closed-form expression for the bit error rate (BER) of OFDM-IIM and the two variants of OFDM-GIM is derived, considering transmissions over Nakagami fading channels and multiple-antenna reception. Finally, OFDM-IIM and OFDM-GIM are compared with state-of-the-art techniques to validate their superiority in terms of BER, achievable rate, and energy efficiency.

High-Dimensional OFDM With In-Phase/Quadrature Index Modulation

In this paper, we propose a new modulation scheme for wireless communications called high-dimensional orthogonal frequency division multiplexing with in-phase/quadrature index modulation (HD-OFDM-IQ-IM). In the proposed scheme, coordinate values of a symbol of the HD signal constellations are separated. A part of the coordinate values of an HD symbol are mapped to the active in-phase component subcarriers and the rest are mapped to the active quadrature component subcarriers in each OFDM subblock. A simple rule to design the HD constellation using the Gray coding and mapping is also presented. The method increases the minimum Euclidean distance between symbols of an HD signal constellation by increasing the Hamming distance of the binary sequences. As the dimension of the constellation increases, more index patterns can be produced, thus improving spectral and energy efficiency of the HD-OFDM-IQ-IM scheme. A feasible selection of subcarrier component active patterns can also produce additional index patterns to enhance spectral efficiency without additional energy consumption. In the receiver, both maximum likelihood (ML) and reduced-complexity log-likelihood ratio (LLR) detection can be exploited. As a result, the proposed scheme has better bit error performance than the conventional OFDM system with IM techniques in the frequency selective Rayleigh fading channel. In particular, it is noted that the bit error rate (BER) in the high signal-to-noise ratio (SNR) region is tightly limited by the upper bound on bit error probability derived in this paper.

Performance analysis of different intensity modulation techniques over atmospheric turbulent free-space optical channels.

In this paper, we introduce a comprehensive study of the performance of intensity modulation (IM) techniques over gamma-gamma (GG) distributed free-space optical (FSO) channels. We derive closed-form expressions for the average bit error rate (BER) of thermal-noise-limited FSO systems adopting various IM techniques. The effect of atmospheric turbulence is studied. Comparisons are presented in terms of the transmitted peak power to achieve a certain BER. Results show that on-off keying, pulse amplitude modulation, and expurgated pulse-position modulation (EPPM) provide superior performance compared to other IM techniques. In addition, a proposal to reduce the peak-to-average power ratio (PAPR) of orthogonal frequency division multiplexing (OFDM) is introduced by adding another modulation layer of EPPM. A closed-form expression for the average BER of the proposed hybrid OFDM-EPPM technique over GG turbulent FSO channel is derived. Moreover, an expression for the outage probability of the FSO system adopting the proposed OFDM-EPPM technique is presented. Results are investigated and compared to those of traditional OFDM and hybrid OFDM with PPM (OFDM-PPM). It is shown that the hybrid OFDM-EPPM technique outperforms the hybrid OFDM-PPM technique for the same data rate. Moreover, the hybrid OFDM-EPPM technique allows higher data rates with lower PAPR values compared to those of the hybrid OFDM-PPM technique for the same number of time slots.

Super-Mode OFDM With Index Modulation

Orthogonal frequency division multiplexing (OFDM) with index modulation (OFDM-IM) appears as a promising multi-carrier waveform candidate for beyond 5G due to its attractive advantages such as operational flexibility and ease of implementation. However, OFDM-IM may not be a proper choice for 5G services such as enhanced mobile broadband (eMBB) since achieving high data rates is challenging because of its null subcarriers. One solution to enhance the spectral efficiency of OFDM-IM is the employment of multiple distinguishable constellations (modes) by also exploiting its null subcarriers for data transmission. This article proposes a novel IM technique called super-mode OFDM-IM (SuM-OFDM-IM), where mode activation patterns (MAPs) and subcarrier activation patterns (SAPs) are jointly selected and conventional data symbols are repetition coded over multiple subcarriers to achieve a diversity gain. For the proposed scheme, a low-complexity detector is designed, theoretical analyses are performed and a bit error rate (BER) upper bound is derived. The performance of the proposed system is also investigated through real-time experiments using a software-defined radio (SDR) based prototype. We show that SuM-OFDM-IM exhibits promising results in terms of spectral efficiency and error performance; thus, appears as a potential candidate for 5G and beyond communication systems.

Management of acute bone loss following high grade open tibia fractures.

Introduction:Optimal treatment for acute post-traumatic bone loss in the tibia remains unclear. Distraction osteogenesis (DO) and induced membrane technique (IM) have been established as the mainstays of treatment. Aim of this article is to review the current evidence regarding the use of these two methods.Methods:A review of the MEDLINE database was performed with strict inclusion and exclusion criteria focusing on treatment of the acute bone loss after open tibia fractures with DO and IM. Bone union rate was taken as the primary outcome and infection rate as secondary outcome.Results:Four studies out of 78 on the use of the DO and three studies out of 18 on the use of the IM technique matched the inclusion criteria. Union rate in the DO group ranged between 92% and 100%, with infection rates between 0 and 4%. In the IM group, union was reached in 42% to 100% of cases, with septic complications occurring in 12% to 43%. Differences in union rate and infection rate reached statistical significance.Discussion:We found a considerable evidence gap regarding treatment of bone loss in high grade open tibia fractures. The limitations of our study prevented us from drawing clear causative conclusions on the results. Although our study points to higher union rates and lower infection rate with the use of the DO technique, the results remain preliminary and further high-level evidence is needed to establish the roles of DO and IM in treatment of acute bone loss in open tibia fractures. (www.actabiomedica.it)

Generalized Multiple-Mode OFDM With Index Modulation

Multiple-mode orthogonal frequency division multiplexing with index modulation (MM-OFDM-IM), which transmits an OFDM signal with information bits embedded onto multiple distinguishable signal constellations of the same cardinality and their permutations, is a recently proposed IM technique in the frequency domain. It is capable of achieving higher spectral efficiency and better error performance than classical OFDM and existing frequency-domain IM schemes. In this paper, we propose the scheme of generalized (G-) MM-OFDM-IM, which allows a different subcarrier to utilize a signal constellation of a different size while conveying the same number of IM bits. Considering phase shift keying constellations, we present design guidelines for GMM-OFDM-IM to achieve an optimal error performance in the asymptotically high signal-to-noise ratio region. A computationally efficient and near-optimal detector based on the idea of sequential decoding is also tailored to GMM-OFDM-IM, which avoids the detection of an illegitimate constellation permutation. Monte Carlo simulations are conducted to validate the inherent properties and advantages of GMM-OFDM-IM.

Comparison of CCS Values Determined by Traveling Wave Ion Mobility Mass Spectrometry and Drift Tube Ion Mobility Mass Spectrometry.

Collision cross section (CCS, Ω) values determined by ion mobility mass spectrometry (IM-MS) provide the study of ion shape in the gas phase and use of these as further identification criteria in analytical approaches. Databases of CCS values for a variety of molecules determined by different instrument types are available. In this study, the comparability of CCS values determined by a drift tube ion mobility mass spectrometer (DTIM-MS) and a traveling wave ion mobility mass spectrometer (TWIM-MS) was investigated to test if a common database could be used across IM techniques. A total of 124 substances were measured with both systems and CCS values of [M + H]+ and [M + Na]+ adducts were compared. Deviations <1% were found for most substances, but some compounds show deviations up to 6.2%, which indicate that CCS databases cannot be used without care independently from the instrument type. Additionally, it was found that for several molecules [2M + Na]+ ions were formed during electrospray ionization, whereas a part of them disintegrates to [M + Na]+ ions after passing through the drift tube and before reaching the TOF region, resulting in two signals in their drift spectrum for the [M + Na]+ adduct. Finally, the impact of different LC-IM-MS settings (solvent composition, solvent flow rate, desolvation temperature, and desolvation gas flow rate) were investigated to test whether they have an influence on the CCS values or not. The results showed that these conditions have no significant impact. Only for karbutilate changes in the drift spectrum could be observed with different solvent types and flow rates using the DTIM-MS system, which could be caused by the protonation at different sites in the molecule.

The British army, information management and the First World War revolution in military affairs

ABSTRACTInformation Management (IM) – the systematic ordering, processing and channelling of information within organisations – forms a critical component of modern military command and control systems. As a subject of scholarly enquiry, however, the history of military IM has been relatively poorly served. Employing new and under-utilised archival sources, this article takes the British Expeditionary Force (BEF) of the First World War as its case study and assesses the extent to which its IM system contributed to the emergence of the modern battlefield in 1918. It argues that the demands of fighting a modern war resulted in a general, but not universal, improvement in the BEF’s IM techniques, which in turn laid the groundwork, albeit in embryonic form, for the IM systems of modern armies.

Interference Management in Ultra-Dense Networks: Challenges and Approaches

Capable of enhancing spatial multiplexing and greatly expanding network capacity, network densification has undoubtedly become a general trend in future wireless networks. However, in addition to the expected advantages, the overuse of spatial resources would result in unpredictable and overwhelming interference as well due to the limited spectrum resources and highly disorganized network infrastructures. Hence, a critical issue arises: are conventional IM techniques still applicable and effective to tackle the interference in UDN? To shed light on the problem, in this article we first investigate the characteristics of interference in UDN and then provide an overview of the existing dominant IM techniques. It is found that, due to the complicated interference, most IM techniques designed for sparse networks would lose their merits when applied in UDN. To reap their potential benefits, we design an IM entity for UDN, aided by which an adaptive on-off power control method is proposed. Results reveal that network capacity could be significantly improved using the proposed method, especially in UDN. In addition, open issues and challenges for IM co-design with stateof- the-art communications technologies are highlighted to provide insight on the potential direction in future wireless networks.

Vascularised fibula or induced membrane to treat congenital pseudarthrosis of the Tibia: A multicentre study of 18 patients with a mean 9.5-year follow-up

BackgroundThe objective of this study was to compare outcomes of two surgical techniques used to treat congenital pseudarthrosis of the tibia (CPT), the induced membrane technique (IM) and the transfer of the contralateral vascularised fibula (VF). HypothesisThe IM technique produces similar outcomes to those of VF grafting in terms of healing and function, while being simpler and having a lower complication rate. Material and methodThis retrospective multicentre study included 18 patients with a mean age of 2.8 years at surgery. Among them, 11 had neurofibromatosis type 1 (NF1). The IM technique was used in 10 patients and VF grafting in 8 patients. Mean follow-up was 9.5 years (range: 5–15 years). ResultsThe two groups showed no significant differences for healing or the occurrence of complications such as limb length discrepancy and residual malalignment. Two patients required amputation, one in each group. The mean number of surgical procedures per patient was 4.7 in the IM group and 5 in the VF group. DiscussionOutcomes are similar with the two techniques. Although VF grafting theoretically involves a single stage, the mean number of surgical procedures was not lower than after the IM technique. The IM technique was associated with lower risks of complications and residual donor site abnormalities. Regardless of the reconstruction technique, the quality of the initial bone resection and internal fixation, particularly regarding alignment, is of the utmost importance. Level of evidenceIV, comparative retrospective study.

Role of Cu on zero valent bimetallic Cu—Fe in arsenic removal with gas bubbling

Arsenic (As) removal by nano bimetallic Cu‐Fe synthesized by in‐situ (Cu‐Fe)IS and impregnation (Cu‐Fe)IM techniques was studied. Synthesized Cu‐Fe by both techniques provided smaller particles than NZVI particles. (Cu‐Fe)IM showed higher efficiency in As removal, compared to (Cu‐Fe)IS and pristine NZVI. Batch experiments were performed by varying percent Cu loading (0–30% by wt). As(III) was removed completely by 10 wt % Cu loading on NZVI under an IM technique. It also provided double removal rate compared to pristine NZVI. X‐ray absorption near edge structure analysis supported that a mixed phases of Cu2O and CuO in (Cu‐Fe)IM enhanced As removal toward co‐precipitating with iron species about 20% for both As(III) and As(V) removal. © 2017 American Institute of Chemical Engineers Environ Prog, 36: 1449–1457, 2017

Comparing Pain of the First-generation Long-Acting Antipsychotic Injections among Three Different IM Techniques

Aim and objectives: To determine the optimal technique to prevent leakage and pain from LAIs, the study compared three types of intramuscular injection techniques: (a) Airbubble technique, (b) Z-track method, and (c) a combination of the air-bubble technique and Z-track method. Background: Long-acting antipsychotic injections (LAIs) are often injected through the muscle, allowing the medication to be slowly absorbed through it. Past literature yields inconclusive results in how to minimize the leakage and pain experienced at the injection site. Design: This experimental study had a within-subjects design. Methods: A total of 144 patients who received the firstgeneration LAIs were purposively sampled from a psychiatry hospital. All participants experienced the three types of injection methods over a 3-month period. They were all asked to rate their level of pain using the numerical rating scale, and after each injection, medical personnel rated the level of medication leakage at the injection site. Results: No significant differences were found in the leakage level between the air-bubble technique, Z-track method, and the combination of the two (F=0.53, p>0.05). Pain level also showed no significant difference between the three types of injection methods during pre-injection (F=0.68 p>.05), 5 minutes post-injection (F=0.87, p>0.05), and 30 minutes post-injection (F=0.97, p>0.05). Conclusion: During the injection of long-acting antipsychotic medication, we suggest consulting the guidance of a clinical injection expert. Choosing an injection method that is most familiar to the nursing staff would allow the minimization of medication leakage and pain at the injection site. Relevance to clinical practice: Nurses should make sure the guidance of a clinical injection expert and verify knowledge of the IM injection skill. Choosing correct injection site and process that can effectively experience of pain and leakage at the injection site.

Multiplexed Detection of MicroRNA Biomarkers Using SERS-Based Inverse Molecular Sentinel (iMS) Nanoprobes.

MicroRNAs (miRNAs) have demonstrated great promise as a novel class of biomarkers for early detection of various cancers, including breast cancer. However, due to technical difficulties in detecting these small molecules, miRNAs have not been adopted into routine clinical practice for early diagnostics. Thus, it is important to develop alternative detection strategies that could offer more advantages over conventional methods. Here, we demonstrate the application of a "turn-on" SERS sensing technology, referred to as "inverse Molecular Sentinel (iMS)" nanoprobes, as a homogeneous assay for multiplexed detection of miRNAs. This SERS nanoprobe involves the use of plasmonic-active nanostars as the sensing platform. The "OFF-to-ON" signal switch is based on a nonenzymatic strand-displacement process and the conformational change of stem-loop (hairpin) oligonucleotide probes upon target binding. This technique was previously used to detect a synthetic DNA sequence of interest. In this study, we modified the design of the nanoprobe to be used for the detection of short (22-nt) miRNA sequences. The demonstration of using iMS nanoprobes to detect miRNAs in real biological samples was performed with total small RNA extracted from breast cancer cell lines. The multiplex capability of the iMS technique was demonstrated using a mixture of the two differently labeled nanoprobes to detect miR-21 and miR-34a miRNA biomarkers for breast cancer. The results of this study demonstrate the feasibility of applying the iMS technique for multiplexed detection of short miRNAs molecules.