Additional Layer Research Articles

Fine-Scale Aerosol-Jet Printing of Luminescent Metal-Organic Framework Nanosheets.

Fabrication of metal-organic framework (MOF) thin films is an ongoing challenge to achieve effective device integration. Inkjet printing has been employed to print various luminescent metal-organic framework (MOF) films. Luminescent metal-organic nanosheets (LMONs), nanometer-thin particles of MOF materials with comparatively large micrometer lateral dimensions, provide an ideal morphology that offers enhancements over analogous MOFs in luminescent properties such as intensity and photoluminescent quantum yield. The morphology is also better suited to the formation of thin films. This work harnesses the preferential features of LMONs to access the advanced technique of aerosol-jet printing (AJP) to print luminescent films with precise geometries and patterns across the micrometer and centimeter length scales. AJP of LMONs exhibiting red (R), green (G), and blue (B) emission were studied systematically to reveal the increase of luminescence upon additive layering printing until a threshold was reached limited by self-quenching. By combining different LMON emitters, emission chromaticity and intensity were shown to be tunable, including the combination of RGB emitters to fabricate white-light-emitting films. A white-light LMON film was printed onto a UV light emitting diode (LED), producing a working white-light-emitting diode. Printing with multiple distinct photoluminescent inks produced intricate multicolor patterns that dynamically responded to excitation wavelength, acting either as micrometer-scale LED-type cells or larger visual tags. Collectively, the work offers an advancement for MOF thin films by printing MON materials using AJP, offering a precise method for manufacturing a wide range of critical functional devices, from luminescent sensors to optoelectronics, and more broadly even the opportunity for printed circuitry with conductive MONs.

Conceptualizing parenthood: American newspaper discourse analysis

This study aims to elucidate the metaphorical representations of the concept PARENT within American media discourse. By analyzing the conceptual metaphors employed in newspaper discourse, we seek to reconstruct the metaphorically derived understanding of parenthood within English-speaking community. These conceptual metaphors, crafted by media presenters, exert a profound influence on the societal comprehension of this concept, both directly and indirectly. The study draws upon the Conceptual Metaphor theory, Conceptual Integration theory, and Discourse analysis. Within the scope of our investigation, the target domain PARENT encompasses four primary source domains: DUTIES, DIFFICULTIES, OWNER, and BURDEN. Our emphasis lies in scrutinizing the cross-domain mappings, which delineate systematic correspondences between the target and source domains. We investigate novel conceptualizations that emerge from conventional metaphoric patterns, employing cognitive mechanisms such as extension, elaboration, questioning, and combination. We also explore the conceptual blends and emergent structures that introduce additional layers of interpretation of being a parent. They are elucidated using Conceptual Integration Networks, specifically double- and multiple-scope models. Our analysis has unveiled the existence of four metaphorical clusters, each providing unique perspectives on how parenthood is conceptualized within the newspaper discourse.

Bond-slip model of headed bar and its application to component-based model for precast concrete joints under accidental loads

This study focused on investigating bond-slip behaviour of headed bars embedded in well-confined concrete. Test results based on eight pull-out specimens under displacement-controlled incremental loading showed that recommended development lengths from ACI318–19 are conservative in developing ultimate strength of headed bars associated with smaller slips than straight bars. Moreover, it was found that different (but sufficiently long) embedment lengths had a significant effect on the free-end slip but negligible effect on the loaded-end slip of headed bars. Additionally, the study highlighted the significance of head bearing in anchorage formation, especially during inelastic stage when bond strength had deteriorated. To address inaccuracy in predicting structural behaviour caused by inadequate anchorage strength of headed bars, a macro bond-slip model was proposed based on correlation in strain distribution obtained from the pull-out tests. Subsequently, the proposed model was incorporated into a component-based model (CBM) and validated against test results of PC joints under seismic loading. A numerical investigation using the validated CBM was conducted to study behaviour of exterior PC joints with headed bars and special detailing. These included Type X joint with X-bent bars and plastic hinge relocation (PHR), and Type A joint with an additional bar layer (ABL) in the beam-joint region, subjected to extreme loads such as seismic action or progressive collapse. The results revealed that seismic behaviour of exterior joints was governed by ductile failure of the beam at the PHR and vertical joint interface in Type X and Type A joints, respectively. Progressive collapse was primarily caused by column failure, with flexural and catenary action effectively preventing collapse. Notably, under both loading conditions, presence of ABL in Type A joint and X-bent bars with PHR in Type X joint improves flexural strength of beams at critical sections and joint shear strength, ultimately enhancing structural performance of joints. Design recommendations include replacing hooked bars with headed bars as well as implementing X-bent bars with PHR and ABL in PC joints. The authors advocate the strong-column-weak-beam design approach as an effective measure to prevent progressive collapse.

Abstract 65: Differential impacts of PD-L1 expression in tumor vs. stroma on survival in esophageal squamous cell carcinoma

Abstract Background: Esophageal squamous cell carcinoma (ESCC) has high incidence and recurrence rates, particularly in advanced stages. While the combined positive score (CPS) and tumor proportional score (TPS) are standard benchmarks for PD-L1 assessment in ESCCs, they face challenges such as reliance on subjective human interpretation and the uncertain clinical significance of strong staining intensities. Our study utilizes H-scores for PD-L1 expression and separates analysis of tumor and stroma, providing additional layers of information that complement current methods and contribute to a more comprehensive understanding of the role of PD-L1 in ESCC. Methods: This retrospective single-center cohort analysis involved 194 cases of ESCC who underwent surgical resection. We performed a comprehensive evaluation of PD-L1 expression within the tumor and stroma using whole slide images (WSI). QuPath image analysis software was used to classify regions as tumor or stroma and quantify the PD-L1 expression H-score. Results: Using optimal H-score cutoffs determined from the minimum P-value method, the Kaplan-Meier survival analysis showed that higher PD-L1 expression was significantly linked with better post-operative survival across all compartments. This correlation was most pronounced in the stroma (P<0.001). However, in multivariate Cox regression analysis, only high tumoral PD-L1 expression emerged as an independent predictor of favorable prognosis (HR=0.47, 95% CI: 0.27-0.81, P=0.007). The non-significant contribution of stromal PD-L1 in this model could be attributed to its association with advanced pT and pN stages, and the presence of lymphatic and venous invasion (P<0.001, respectively). Interestingly, stromal PD-L1 expression was associated with a longer duration of cytotoxic chemotherapy (cutoff 8 months, Median H-score 98.28 vs 55.24, P=0.026), but no significant correlation was observed with the duration of immune checkpoint inhibitor treatment. Conclusions: The study underscores the complex role of PD-L1 in ESCC, with tumoral PD-L1 expression emerging as an independent prognostic factor, and stromal PD-L1 expression found to be related with tumor progression and the duration of cytotoxic chemotherapy response. Citation Format: Tomohiro Murakami, Satoru Furuhashi, Yuuki Sakai, Kenichi Sekimori, Ryoma Haneda, Eisuke Booka, Tomohiro Matsumoto, Hirotoshi Kikuchi, Yoshihiro Hiramatsu, Hiroya Takeuchi. Differential impacts of PD-L1 expression in tumor vs. stroma on survival in esophageal squamous cell carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 65.

Development of a platform method for rapid detection and characterization of domain-specific post-translational modifications in bispecific antibodies

Charge heterogeneity is inherent to all therapeutic antibodies and arises from post-translational modifications (PTMs) and/or protein degradation events that may occur during manufacturing. Among therapeutic antibodies, the bispecific antibody (bsAb) containing two unique Fab arms directed against two different targets presents an additional layer of complexity to the charge profile. In the context of a bsAb, a single domain-specific PTM within one of the Fab domains may be sufficient to compromise target binding and could potentially impact the stability, safety, potency, and efficacy of the drug product. Therefore, characterization and routine monitoring of domain-specific modifications is critical to ensure the quality of therapeutic bispecific antibody products. We developed a Digestion-assisted imaged Capillary isoElectric focusing (DiCE) method to detect and quantitate domain-specific charge variants of therapeutic bispecific antibodies (bsAbs). The method involves enzymatic digestion using immunoglobulin G (IgG)-degrading enzyme of S. pyogenes (IdeS) to generate F(ab)2 and Fc fragments, followed by imaged capillary isoelectric focusing (icIEF) under reduced, denaturing conditions to separate the light chains (LCs) from the Fd domains. Our results suggest that DiCE is a highly sensitive method that is capable of quantitating domain-specific PTMs of a bsAb. In one case study, DiCE was used to quantitate unprocessed C-terminal lysine and site-specific glycation of Lys98 in the complementarity-determining region (CDR) of a bsAb that could not be accurately quantitated using conventional, platform-based charge variant analysis, such as intact icIEF. Quantitation of these PTMs by DiCE was comparable to results from peptide mapping, demonstrating that DiCE is a valuable orthogonal method for ensuring product quality. This method may also have potential applications for characterizing fusion proteins, antibody-drug conjugates, and co-formulated antibody cocktails.

TTDCapsNet: Tri Texton-Dense Capsule Network for complex and medical image recognition.

Convolutional Neural Networks (CNNs) are frequently used algorithms because of their propensity to learn relevant and hierarchical features through their feature extraction technique. However, the availability of enormous volumes of data in various variations is crucial for their performance. Capsule networks (CapsNets) perform well on a small amount of data but perform poorly on complex images. To address this, we proposed a new Capsule Network architecture called Tri Texton-Dense CapsNet (TTDCapsNet) for better complex and medical image classification. The TTDCapsNet is made up of three hierarchic blocks of Texton-Dense CapsNet (TDCapsNet) models. A single TDCapsNet is a CapsNet architecture composed of a texton detection layer to extract essential features, which are passed onto an eight-layered block of dense convolution that further extracts features, and then the output feature map is given as input to a Primary Capsule (PC), and then to a Class Capsule (CC) layer for classification. The resulting feature map from the first PC serves as input into the second-level TDCapsNet, and that from the second PC serves as input into the third-level TDCapsNet. The routing algorithm receives feature maps from each PC for the various CCs. Routing the concatenation of the three PCs creates an additional CC layer. All these four feature maps combined, help to achieve better classification. On fashion-MNIST, CIFAR-10, Breast Cancer, and Brain Tumor datasets, the proposed model is evaluated and achieved validation accuracies of 94.90%, 89.09%, 95.01%, and 97.71% respectively. Findings from this work indicate that TTDCapsNet outperforms the baseline and performs comparatively well with the state-of-the-art CapsNet models using different performance metrics. This work clarifies the viability of using Capsule Network on complex tasks in the real world. Thus, the proposed model can be used as an intelligent system, to help oncologists in diagnosing cancerous diseases and administering treatment required.

Peeling the onion: additional layers of regulation in the acid stress response.

Bacteria are capable of withstanding large changes in osmolality and cytoplasmic pH, unlike eukaryotes that tightly regulate their pH and cellular composition. Previous studies on the bacterial acid stress response described a rapid, brief acidification, followed by immediate recovery. More recent experiments with better pH probes have imaged single living cells, and we now appreciate that following acid stress, bacteria maintain an acidic cytoplasm for as long as the stress remains. This acidification enables pathogens to sense a host environment and turn on their virulence programs, for example, enabling survival and replication within acidic vacuoles. Single-cell analysis identified an intracellular pH threshold of ~6.5. Acid stress reduces the internal pH below this threshold, triggering the assembly of a type III secretion system in Salmonella and the secretion of virulence factors in the host. These pathways are significant because preventing intracellular acidification of Salmonella renders it avirulent, suggesting that acid stress pathways represent a potential therapeutic target. Although we refer to the acid stress response as singular, it is actually a complex response that involves numerous two-component signaling systems, several amino acid decarboxylation systems, as well as cellular buffering systems and electron transport chain components, among others. In a recent paper in the Journal of Bacteriology, M. G. Gorelik, H. Yakhnin, A. Pannuri, A. C. Walker, C. Pourciau, D. Czyz, T. Romeo, and P. Babitzke (J Bacteriol 206:e00354-23, 2024, https://doi.org/10.1128/jb.00354-23) describe a new connection linking the carbon storage regulator CsrA to the acid stress response, highlighting new additional layers of complexity.

JUN mRNA translation regulation is mediated by multiple 5' UTR and start codon features.

Regulation of mRNA translation by eukaryotic initiation factors (eIFs) is crucial for cell survival. In humans, eIF3 stimulates translation of the JUN mRNA which encodes the transcription factor JUN, an oncogenic transcription factor involved in cell cycle progression, apoptosis, and cell proliferation. Previous studies revealed that eIF3 activates translation of the JUN mRNA by interacting with a stem loop in the 5' untranslated region (5' UTR) and with the 5' -7-methylguanosine cap structure. In addition to its interaction site with eIF3, the JUN 5' UTR is nearly one kilobase in length, and has a high degree of secondary structure, high GC content, and an upstream start codon (uAUG). This motivated us to explore the complexity of JUN mRNA translation regulation in human cells. Here we find that JUN translation is regulated in a sequence and structure-dependent manner in regions adjacent to the eIF3-interacting site in the JUN 5' UTR. Furthermore, we identify contributions of an additional initiation factor, eIF4A, in JUN regulation. We show that enhancing the interaction of eIF4A with JUN by using the compound Rocaglamide A (RocA) represses JUN translation. We also find that both the upstream AUG (uAUG) and the main AUG (mAUG) contribute to JUN translation and that they are conserved throughout vertebrates. Our results reveal additional layers of regulation for JUN translation and show the potential of JUN as a model transcript for understanding multiple interacting modes of translation regulation.

Molecular mechanisms reconstruction from single-cell multi-omics data with HuMMuS.

The molecular identity of a cell results from a complex interplay between heterogeneous molecular layers. Recent advances in single-cell sequencing technologies have opened the possibility to measure such molecular layers of regulation. Here, we present HuMMuS, a new method for inferring regulatory mechanisms from single-cell multi-omics data. Differently from the state-of-the-art, HuMMuS captures cooperation between biological macromolecules and can easily include additional layers of molecular regulation. We benchmarked HuMMuS with respect to the state-of-the-art on both paired and unpaired multi-omics datasets. Our results proved the improvements provided by HuMMuS in terms of transcription factor (TF) targets, TF binding motifs and regulatory regions prediction. Finally, once applied to snmC-seq, scATAC-seq and scRNA-seq data from mouse brain cortex, HuMMuS enabled to accurately cluster scRNA profiles and to identify potential driver TFs. HuMMuS is available at https://github.com/cantinilab/HuMMuS.

Very rare arrangement of the pes anserinus: potential clinical significance.

The pes anserinus superficialis is composed of the semitendinosus, gracilis and sartorius tendons. Normally, they all insert to the medial side of the tibial tuberosity, and the first two are attached superiorly and medially to the tendon of the sartorius muscle. During anatomical dissection, a new pattern of arrangement of tendons creating the pes anserinus was found. The pes anserinus comprised three tendons; the semitendinosus tendon was located superiorly to the gracilis tendon, and they both had distal attachments on the medial side of the tibial tuberosity. This seemed like the normal type, but the tendon of the sartorius muscle created an additional superficial layer, its proximal part lying just below the gracilis tendon and covering the semitendinosus tendon and a small part of the gracilis tendon. After crossing the semitendinosus tendon it is attached to the crural fascia significantly below the tibial tuberosity. Good knowledge of the morphological variations of the pes anserinus superficialis is necessary during surgical procedures in the knee region, especially anterior ligament reconstruction.

Analysis and Design of a High Gain Multiband Antenna Based on Metamaterials for RFID Applications

In this research work, the design of a dipole antenna based on metamaterials is proposed, which can be used as a high gain multiband communication device for RFID applications. This antenna is printed on two sides of an Arlon substrate, which has an overall electrical dimension of 0.39 λ0×0.11 λ0×0.0014 λ0. The metamaterials are used to obtain a multiband antenna, and their integration technique into the antenna results in a high gain compared to a conventional antenna without any magnification or additional layer. The simulated and measured results show that the proposed antenna can operate at 0.88-0.97 GHz, 2.41-2.48 GHz, and 5.77-5.91 GHz with a reflection coefficient of less than −10 dB, which make it well suited for RFID at 860-960 MHz and 2.4 GHz/5.8 GHz. All these resonant frequencies show better impedance matching with high gain. The proposed antenna has the advantages of simple design, low profile, easy feeding, low manufacturing cost, and easy integration into the electronic circuit.

A class of computational methods to reduce selection bias when designing Phase 3 clinical trials.

When designing confirmatory Phase 3 studies, one usually evaluates one or more efficacious and safe treatment option(s) based on data from previous studies. However, several retrospective research articles reported the phenomenon of "diminished treatment effect in Phase 3" based on many case studies. Even under basic assumptions, it was shown that the commonly used estimator could substantially overestimate the efficacy of selected group(s). As alternatives, we propose a class of computational methods to reduce estimation bias and mean squared error with a broader scope of multiple treatment groups and flexibility to accommodate summary results by group as input. Based on simulation studies and a real data example, we provide practical implementation guidance for this class of methods under different scenarios. For more complicated problems, our framework can serve as a starting point with additional layers built in. Proposed methods can also be widely applied to other selection problems.

Building Trust in the AI Ecosystem by Re-Evaluating Public Perception

Artificial intelligence systems leverage large datasets with iterative processing algorithms that identify patterns to create an additional layer of expertise. This transformational power operates in tandem with ethical risks. The dominant narrative behind AI is simultaneously stigmatized and misunderstood: with exponential growth of the ubiquitous technology leaving public awareness in the dust, it's becoming increasingly important to balance enthusiasm for AI's enormous promise with a sober understanding of its moral risks. This study seeks to characterize the public opinion of AI in high-risk, domain-specific applications. To that end, a poll was administered to American adults. The results of the study reveal that the great majority of survey respondents have a neutral or optimistic perspective on AI in particular high-risk domains. The study concludes by presenting a standard heuristic for understanding public perception where ethics may fail to preserve a human factors' approach. In this way, researchers and developers can undertake coordinated efforts to mitigate the harm caused by AI while promoting rational optimism in vulnerable populations.

Dissonance In the Public Eye: Understanding the Role of Initial Affection and Deviation Size on Negative Evaluations

This study examined the impact of a public figure's deviation from societal expectations on public perceptions and economic support intentions. We hypothesized that smaller deviations would induce higher negative evaluations, and that initial personal liking for the figure would interact with deviation size to affect these evaluations. Although we did not find substantial support for our primary hypothesis, we observed an interaction effect consistent with our secondary hypothesis. Specifically, among those who initially liked the figure, minor deviations incited marginally higher negative evaluations than significant deviations. The findings suggest that initial affection introduces an additional layer of complexity in public reactions to a figure's deviations, which aligns with the Cognitive Dissonance Theory. Interestingly, participants were more likely to endorse harm for smaller deviations, implying that society tends to reprimand public figures more severely for minor deviations. There were no significant effects observed for economic support intentions. The study's implications are discussed in the context of understanding public figures' influence and societal reactions. These findings highlight the intricate dynamics of public sentiment and emphasize the need for future research to continue exploring these multifaceted relationships.

Technical assessment of resolution of handheld ultrasound devices and clinical implications.

Since handheld ultrasound devices are becoming increasingly ubiquitous, objective criteria to determine image quality are needed. We therefore conducted a comparison of objective quality measures and clinical performance. A comparison of handheld devices (Butterfly IQ+, Clarius HD, Clarius HD3, Philips Lumify, GE VScan Air) and workstations (GE Logiq E10, Toshiba Aplio 500) was performed using a phantom. As a comparison, clinical investigations were performed by two experienced ultrasonographers by measuring the resolution of anatomical structures in the liver, pancreas, and intestine in ten subjects. Axial full width at half maximum resolution (FWHM) of 100µm phantom pins at depths between one and twelve cm ranged from 0.6-1.9mm without correlation to pin depth. Lateral FWHM resolution ranged from 1.3-8.7mm and was positively correlated with depth (r=0.6). Axial and lateral resolution differed between devices (p<0.001) with the lowest median lateral resolution observed in the E10 (5.4mm) and the lowest axial resolution (1.6mm) for the IQ+ device. Although devices showed no significant differences in most clinical applications, ultrasonographers were able to differentiate a median of two additional layers in the wall of the sigmoid colon and one additional structure in segmental portal fields (p<0.05) using cartwheel devices. While handheld devices showed superior or similar performance in the phantom and routine measurements, workstations still provided superior clinical imaging and resolution of anatomical substructures, indicating a lack of objective measurements to evaluate clinical ultrasound devices.

Channel-spatial knowledge distillation for efficient semantic segmentation

In this paper, we propose a new lightweight Channel-Spatial Knowledge Distillation (CSKD) method to handle the task of efficient image semantic segmentation. More precisely, we investigate the KD approach that train a compressed neural network called student under the supervision of a heavy one called teacher. In this context, we propose to improve the distillation mechanism by capturing the contextual dependencies in spatial and channel dimensions through a self-attention principle. In addition, to quantify the difference between the teacher and student knowledge, we adopt the Centered Kernel Alignment (CKA) metric that avoids the student to add additional leaning layers to match the teacher features size. Experimental results over Cityscapes, CamVid and Pascal VOC datasets demonstrate that our method can achieve outstanding performance. The code is available at https://github.com/ayoubkarine/CSKD.

Structural study of nickelate based heterostructures

Heterostructures consisting of SmNiO3 and NdNiO3 alternating layers with additional LaAlO3 spacer layers were grown and fully characterized by means of x-ray diffraction, atomic force microscopy, and scanning transmission electron microscopy. A change in the orientation of the orthorhombic long-axis of the nickelate layers is observed when a single unit cell of LaAlO3 is inserted between SmNiO3 and NdNiO3, in agreement with density functional theory calculations. At the same time, the structure of the ultra-thin rhombohedral LaAlO3 layers is affected by their proximity to orthorhombic nickelate layers, with both scanning transmission electron microscopy studies and density functional theory calculations revealing a weak antipolar motion of the La-cation in the LaAlO3 layers that is not present in the bulk rhombohedral structure of this compound.

The readout panels for the BI-RPC project for ATLAS Phase-II upgrade

To take full advantage from the LHC upgrade to high luminosity in 2029, the ATLAS community has approved an intensive detector upgrade program that includes the construction of an additional trigger layer positioned close to the BI MDT chambers of the muon spectrometer. These chambers are RPC with thin gas gap, thin High Pressure Laminate electrodes coated with graphite on one side, and only use strips orthogonal to the beam-axis to reconstruct the eta and phi coordinates of the detector point where an ionizing particle passes. A detailed description of the construction and validation of these strip panels in China and Italy assembly sites, is presented here.

The effects of celebrity endorser on consumer advocacy behavior through the customization and entertainment intention – A multivariate analysis

Purpose The purpose of this study is to investigate the effects of celebrity endorsers on consumer advocacy, customization and entertainment intentions based on the notion of the stimulus–organism–response (SOR) framework. In addition, this study aims to examine the mediating and moderating role of customization and entertainment intentions on the proposed relationships. The authors also intend to highlight the comparative effects between male and female young social media consumers on those proposed associations. Design/methodology/approach In the pursuit of comprehensive and rigorous data collection, this study adopted a quantitative methodology using a meticulously crafted questionnaire. The questionnaire survey was conducted in major cities of Malaysia using the convenience and snowball sampling techniques. A total of 576 responses were collected, even though 549 retorts were used for data analysis. In this investigation, the authors strategically used covariance-based structural equation modeling through the use of AMOS v. 24 as the primary data analysis tool. Augmenting the analytical depth, the authors also conducted a supplementary bootstrap analysis. The additional layers of examination were crucial for appraising the mediating and moderating effects inherent within the model, in which the PROCESS MACRO v.4.20 was used. Findings The results of this study revealed the significant direct positive effects of celebrity endorsers on consumer customization, entertainment and advocacy intentions. Consumer customization and entertainment intentions also found significant direct affirmative effects on consumer advocacy intention, along with the significant direct positive effects of consumer entertainment intention on consumer customization intention. The results further revealed that consumer customization and entertainment intentions cannot mediate the relationship between celebrity endorsers and advocacy intention. The entertainment intention also declined the mediating effects between celebrity endorsers and consumer customization intention. On the contrary, consumer customization intention significantly and positively, and entertainment intention also significantly but negatively, moderate the association between celebrity endorsers and consumer advocacy intention. This study also illustrates that the effects of those examined relationships differ between male and female young social media consumers. Originality/value This study investigates the impact of celebrity endorsers on consumer behavior, focusing on their customization, entertainment and advocacy intentions. It extends current SOR framework, enhances source credibility theory, fills gaps in the literature on social media brand engagement and underscores the significance of customization and entertainment intentions. The findings provide insights for managers aiming to harness consumer brand advocacy through celebrity endorsers effectively.

Hydrophilic Interaction Liquid Chromatography-Hydrogen/Deuterium Exchange-Mass Spectrometry (HILIC-HDX-MS) for Untargeted Metabolomics.

Liquid chromatography with mass spectrometry (LC-MS)-based metabolomics detects thousands of molecular features (retention time-m/z pairs) in biological samples per analysis, yet the metabolite annotation rate remains low, with 90% of signals classified as unknowns. To enhance the metabolite annotation rates, researchers employ tandem mass spectral libraries and challenging in silico fragmentation software. Hydrogen/deuterium exchange mass spectrometry (HDX-MS) may offer an additional layer of structural information in untargeted metabolomics, especially for identifying specific unidentified metabolites that are revealed to be statistically significant. Here, we investigate the potential of hydrophilic interaction liquid chromatography (HILIC)-HDX-MS in untargeted metabolomics. Specifically, we evaluate the effectiveness of two approaches using hypothetical targets: the post-column addition of deuterium oxide (D2O) and the on-column HILIC-HDX-MS method. To illustrate the practical application of HILIC-HDX-MS, we apply this methodology using the in silico fragmentation software MS-FINDER to an unknown compound detected in various biological samples, including plasma, serum, tissues, and feces during HILIC-MS profiling, subsequently identified as N1-acetylspermidine.