Two-dimensional Mass Research Articles

RNA Modification and Digestive Tract Tumors: A Review.

Gastrointestinal tumors, including colorectal and liver cancer, are among the most prevalent and lethal solid tumors. These malignancies are characterized by worsening prognoses and increasing incidence rates. Traditional therapeutic approaches often prove ineffective. Recent advancements in high-throughput sequencing and sophisticated RNA modification detection technologies have uncovered numerous RNA chemical alterations significantly associated with the pathogenesis of various diseases, notably cancer. These discoveries have opened new avenues for therapeutic intervention. This article delves into epigenetic modifications, with a particular emphasis on RNA alterations such as N6-methyladenosine (m6A), 5-methylcytosine (m5C), 1-methyladenosine (m1A), 7-methylguanosine (m7G), and N4-acetylcysteine (ac4C). It examines the functions and mechanisms of action of regulatory entities known as "Writers," "Readers," and "Erasers" to these modifications. Additionally, it outlines various methodologies for detecting these RNA modifications. Conventional techniques include radioactive isotope incorporation, two-dimensional thin-layer chromatography (2D-TLC), mass spectrometry, and immunological detection methods. Specialized methods such as bisulfite sequencing and reverse transcription stops are also discussed. Furthermore, the article underscores the significance of these modifications in the development, progression, and therapeutic targeting of gastrointestinal tumors, including esophageal, gastric, colorectal, liver, and pancreatic cancers. This exploration provides foundational insights for enhancing diagnostic accuracy, treatment efficacy, and prognostic assessment in gastrointestinal oncology.

Understanding the Formation Dynamics and Physical Properties of Nanocapsules Using Charge Detection Mass Spectrometry.

Characterizing the size, structure, and composition of nanoparticles is vital in predicting and understanding their macroscopic properties. In this work, charge detection mass spectrometry (CDMS) was used to analyze nanocapsules (∼10-200 MDa) consisting of a liquid oleic acid core surrounded by a dense silica outer shell. CDMS is an emerging method for nanoparticle analysis that can rapidly measure the mass and charge of thousands of individual nanoparticles. We find that increasing the feed volume of the tetraethylorthosilicate (TEOS) precursor added to form the silica shell of the nanocapsules yielded both higher and broader nanocapsule mass distributions with differentiable densities. A two-dimensional mass versus charge analysis also revealed the formation of two distinct populations of nanocapsules. These two nanocapsule morphologies were also present in transmission electron microscopy (TEM) images and exhibited low-density spherical cores and crescent-shaped cores where the remainder of the core volume was "filled in" by more dense silica. Nanocapsule shell growth kinetics over a ∼48-h synthesis period were also monitored by sampling the reaction mixture at various times, quenching the sampled aliquots, and then characterizing these time-resolved samples by CDMS. The CDMS data reveal three distinct growth phases in nanocapsule formation; rapid initial nucleation, an "inverted" distribution of silica growth, and a final slow growth phase where the rate of mass increase and final nanocapsule masses are dictated by the initial TEOS feed volumes. CDMS-enabled understanding of the diverse nanocapsule sizes, morphologies, and growth dynamics will allow us to better predict nanocapsule properties while reducing the experimental burden in optimizing nanocapsules for real-world applications.

Sorbent-Based Sampling With Two-Stage Trapping/Desorption Coupled to Comprehensive Two-Dimensional Gas Chromatography and Mass Spectrometry for Terpenoids Profiling in Cannabis.

Cannabis inflorescences represent an important source of many high-value bioactive specialized metabolites, among which the family of terpenes or terpenoids that are the largest classes of natural products known. Besides their biological activities either alone or synergistic with other terpenoids and/or cannabinoids, they are responsible for their distinctive flavour. In this study, we exploited the separation power and identification capabilities of comprehensive two-dimensional gas chromatography coupled to mass spectrometry (GC×GC-MS) for the profiling of terpenes and terpenoids in cannabis inflorescences. The dynamic headspace (DHS) used herein for the extraction was chosen for its sensitivity, portability, suitability, as well as its versatility of sampling various natural products, including plant raw materials and different plant parts. The enrichment method and the following desorption into the GC were developed and optimized on both standards and real samples considering different sorbent traps (i.e. Tenax-TA, Carbotrap T420, Carbotrap 202), and evaluating key performance values. Analyte coverage, recovery and response reproducibility were used for the evaluation of the best performing thermal desorption tube. Considering terpenoids profiling on cannabis inflorescences, satisfactory extraction performance was observed with both Tenax-TA and Carbotrap T420. However, Tenax-TA provided a wider analyte coverage beyond the class of terpenoids, thus can be better suited for non-targeted analysis. On the other hand, peak width, peak height, peak quality and resolution were considered for the optimization of the chromatographic process, and more specifically the injection process, demonstrating the benefit of a secondary trapping/desorption stage with a cryotrap. Finally, considering the final DHSE-TD-GC×GC-MS conditions, terpenes and terpenoids were profiled in real-world cannabis inflorescences, highlighting the differences among the chemovars.

Application of the Immersed Boundary Method in the Study of Two Tandem Cylinders

The study of fluid flow around various surfaces is crucial in several applications of mechanical engineering, especially in cylindrical geometries of circular section, common in structures such as bridges, wind turbines, cooling systems, and power towers. In this work, we solve the two-dimensional mass conservation and Navier-Stokes equations in the x and y variables, ignoring gravitational effects, applying the Fourier pseudo-spectral method coupled with the immersed boundary method. We define a domain with two cylindrical boundaries of diameter equal to 0.0016m and a low Reynolds number. The obtained results are promising, approaching existing literature reviews.

Pharmacokinetics of Oral Cannabinoid Δ8-Tetrahydrocannabivarin and Its Main Metabolites in Healthy Participants.

Tetrahydrocannabivarin (THCV) is a phytocannabinoid commonly found in cannabis with potential pharmacological properties; however, its post-acute pharmacokinetics (PK) in humans have not been studied yet. THCV has two isomers, Δ9- and Δ8-THCV, which seem to have different pharmacological properties. We investigated the PK of the Δ8-THCV isomer after oral administration as part of a two-phase, dose-ranging, placebo-controlled trial in healthy participants. Participants (n = 21) were enrolled in six study sessions and randomly received the following doses of a medium-chain triglyceride (MCT) oil oral formulation of Δ8-THCV: placebo, 12.5 mg, 25 mg, 50 mg, 100 mg, and 200 mg. Plasma samples from 15 participants were collected up to 8 h after administration and were analyzed by a validated two-dimensional high-performance liquid chromatography-tandem mass spectrometry assay. The trial was registered on clinicaltrials.gov (NCT05210634). After oral administration, 11-nor-9-carboxy-Δ8-THCV (Δ8-THCV-COOH) was the main metabolite detected. The median time-to-maximum concentration (tmax) ranged 3.8-5.0 h across doses for Δ8-THCV and 4.6-5.3 h for Δ8-THCV-COOH. The maximum concentration (Cmax) and area under the concentration-time curve over the observation period (AUClast) appeared to be dose-linear. Median AUClast increased 2.3- to 4.8-fold and 1.7- to 2.9-fold for Δ8-THCV and Δ8-THCV-COOH, respectively, every two-fold increase in the dose. The isomers Δ9-THCV and Δ9-THCV-COOH were detected in plasma, despite being undetected in the formulated drug product analyzed by a third-party laboratory. For the first time, we report the pharmacokinetics of Δ8-THCV and its major metabolites after oral administration in humans. Δ8-THCV AUClast showed dose linearity but the observed possible conversion to the Δ9-THCV isomer should be further studied.

Flow of viscoelastic films over grooved surfaces with partial wetting

We consider the steady flow of a viscoelastic film over an inclined plane featuring periodic trenches normal to the main flow direction. The trenches have a square cross-section and side length 5–8 times the capillary length. Owing to the orientation of the substrate, the film fails to coat the topographical feature entirely, forming a second gas–liquid interface inside the trench and two three-phase contact lines at the points where the free surface meets the wall of the trench. The volume of entrapped air depends on material and flow parameters and geometric conditions. We develop a computational model and carry out detailed numerical simulations based on the finite element method to investigate this flow. We solve the two-dimensional mass and momentum conservation equations using the exponential Phan-Thien & Tanner constitutive model to account for the rheology of the viscoelastic material. Due to the strong nonlinearity, multiple steady solutions possibly connected by turning points forming hysteresis loops, transcritical bifurcations and isolated solution branches are revealed by pseudo-arc-length continuation. We perform a thorough parametric analysis to investigate the combined effects of elasticity, inertia, capillarity and viscosity on the characteristics of each steady flow configuration. The results of our simulations indicate that fluid inertia and elasticity may or may not promote wetting, while shear thinning and hydrophilicity always promote the wetting of the substrate. Interestingly, there are conditions under which the transition to the inertial regime is not smooth, but a hysteresis loop arises, signifying an abrupt change in the film hydrodynamics. Additionally, we investigate the effect of the geometrical characteristics of the substrate, and our results indicate that there is a unique combination of the geometry and viscoelastic properties that either maximizes or minimizes the wetting lengths.

Identification strategy of wild and cultivated Astragali Radix based on REIMS combined with two-dimensional LC-MS

A rapid and real-time method was established based on the combination of rapid evaporative ionization mass spectrometry (REIMS) and two-dimensional liquid chromatography mass spectrometry (2DLC-MS) for identification of wild Astragali Radix (WAR) and cultivated AR (CAR). The samples were analyzed under ambient ionization without time-consuming sample preparation. The phenotypic data of WAR and CAR were used to develop a real-time recognition model. Subsequently, the compounds in these two species were comprehensively characterized based on 2DLC-MS, and 45 different compounds were screened out by multivariate statistical analysis. A semi-quantitative method for 45 different compounds was established based on ultrahigh-performance liquid chromatography/quadrupole-linear ion trap mass spectrometry (UHPLC-QTRAP-MS). The results showed that the relative content of most compounds in WAR was higher than in CAR. In summary, the method has demonstrated remarkable performance in distinguishing between WAR and CAR, providing a reference in the field of traditional Chinese medicine (TCM) analysis and identification.

Comparative Proteomic Analysis of Cell Wall Proteins of Aminoglycosides Resistant and Sensitive Mycobacterium tuberculosis Clinical Isolates.

The rising prevalence of Mycobacterium tuberculosis (M.tb) strains resistant to aminoglycosides (amikacin and kanamycin) challenges effective TB control and treatment. Understanding the mechanisms behind this resistance is crucial since aminoglycosides are a mainstay of TB therapy. The study aimed to analyze the cell wall proteins overexpressed in aminoglycoside-resistant isolates of Mycobacterium tuberculosis using proteomics approaches. We used two-dimensional electrophoresis and mass spectrometry to compare the cell wall proteomes of aminoglycosides-resistant and susceptible clinical isolates. The overexpressed protein spots were excised and identified using liquid chromatography-mass spectrometry (LC/MS). The identified proteins were subsequently analyzed for molecular docking, pupylation site identification, and STRING analysis. We found a total of nine significantly upregulated proteins in aminoglycosides-resistant isolates. Three of these proteins were the same (isoform), resulting in the identification of seven unique proteins. Specifically, Rv3841 and Rv1308 belonged to intermediary metabolism and respiration; Rv2115c to the cell wall and cell processes; Rv2501c, Rv2247 and Rv0295c to lipid metabolism; and Rv2416c to virulence, detoxification/adaptation. Notably, variations in these proteins support cell wall integrity, aiding mycobacteria's establishment and proliferation. Molecular docking study revealed that both drugs bind strongly to the proteins' active site regions. Additionally, the GPS-PUP algorithm successfully identified possible pupylation sites within these proteins, except Rv0295c. Based on interactome analysis using the STRING 12.0 database, we have identified potential interactive partners suggesting their role in aminoglycosides resistance. Overexpressed proteins not only act to counteract or regulate drug effects but also have a role in protein dynamics that allow for resistance. Some of these identified proteins may serve as innovative drug targets and biomarkers for the early detection of drug-specific resistance in M.tb. Further research is needed to elucidate the mechanisms by which these potential protein targets contribute to resistance in AK and KM M.tb isolates.

Comparative Investigation of Aroma-Active Volatiles in ("Ruixue", "Liangzhi", "Crystal Fuji," and "Guifei") Apples by Application of Gas Chromatography-Mass Spectrometry-Olfactometry (GC-MS-O) and Two-Dimensional Gas Chromatography-Quadrupole Mass Spectrometry (GC × GC-qMS) Coupled with Sensory Molecular Science.

Aroma dramatically impacts the overall flavor profiles and consumer acceptance; therefore, it is necessary to conduct a comprehensive analysis of the aroma characteristics of apples. In this study, the aroma differences among four popular apple varieties ("Ruixue", "Liangzhi", "Crystal Fuji," and "Guifei") were compared using two extraction methods (headspace-solid phase microextraction, and solvent-assisted flavor evaporation) coupled with gas chromatography-mass spectrometry-olfactometry (GC-MS-O) and two-dimensional gas chromatography-quadrupole mass spectrometry (GC × GC-qMS). A total of 82 odorants were identified via GC-MS-O, and 143 volatiles were identified by GC× GC-qMS. Among them, 41 key aroma-active compounds (butanal, ethyl acetate, 3-methylbutanal, methyl butanoate, 2-methylpropyl acetate, ethyl 2-methylbutanoate, ethyl 3-methylbutanoate, butyl acetate, hexanal, 2-methylbutyl acetate, 1-butanol, 2-methylpropyl butanoate, 3-methylbutyl acetate, (E)-2-hexenal, butyl butanoate, butyl 2-methylbutanoate, hexyl acetate, hexyl butanoate, hexyl, 2-methylbutanoate, 1-octen-3-ol, 3-methylthiopropanol, 1,3-octanediol, linalyl acetate, and so on) with high odor activity values (OAVs) and AI value (odor activity values ≥1 or aroma intensity ≥3) were identified. Partial least-squares-discriminant analysis showed that Ruixue exhibited a high "fruity" note, Guifei and Crystal Fuji had the greatest "wood," "floral," and "sweet" notes, while Liangzhi presented a significant "green" note. This study provided flavor chemistry support for the apple quality control and production.

Model-based optimization strategies for direct hydrogenation of carbon dioxide to dimethyl ether

This study discusses model-based optimization strategies for CO2 hydrogenation to dimethyl ether (DME) over a CuZnZr (CZZ) and ferrite (FER) mixed catalyst system in a packed-bed reactor configuration. A two-dimensional axisymmetric, nonisothermal packed-bed reactor model was developed using COMSOL Multiphysics 6.2 software. The model solves two-dimensional (radial and axial) heat and mass transport equations in the packed-bed and integrates intraparticle diffusion and heat transfer in a 1D approach. This powerful feature differs from a traditional porous media approach and takes into account any heat and mass transfer limitations that may exist. Analysis shows that the heat transfer limitations are negligible, but strong internal mass transfer limitations were observed at 10 ≤ WHSV ≤ 90 h−1 on the FER catalyst and at 240 °C. The optimum catalyst composition (i.e., mixing ratio) varies depending on the operating regime. The FER catalyst weight in the mixture can be as low as 5 wt.%, but the ideal composition depends on the internal mass transfer limitation and its relationship with the operating regime (i.e., weight hourly space velocity, temperature). A catalyst composition of 80 wt.% CZZ and 20 wt.% FER was suggested; this composition can provide high CO2 conversion and DME production rates at a wide range of temperatures and flow rates.

Fellgett Revisited: On the Nature of Noise in Two-Dimensional Mass Spectrometry.

Two-dimensional mass spectrometry (2DMS) is a truly data-independent acquisition technique used in the analysis of complex mixtures; however, the nature of the noise within these spectra is not well understood. In this work, 2DMS is tested for conformity with the Fellgett principle: (signal/noise) ∝ √ (no. of data points). Since 2DMS functions through the modulation of ions through a fragmentation region across many scans, the individual scans are considered data points in this experiment. Random noise was shown to be prevalent as the main source of noise in this experiment with minor systematic noise. This means that the minimum size for a 2DMS spectrum that displays a target fragment ion can be determined using a fast-2D equation detailed herein. The effects of existing denoising algorithms were also found to change the relationship between the signal-to-noise ratio and the scan numbers to be of a quasi-linear nature rather than the square root trend observed before denoising.

Virgin Olive oil Authenticity Assays in a Single Run Using Two-Dimensional Liquid Chromatography-High Resolution Mass Spectrometry.

Sterols and triterpenic alcohol analyses are one of the officially established parameters for assessing the authenticity of virgin olive oil (VOO). Most of the applications described for sterol analysis, including the official method, only allow the determination of the total sterol content but not its distribution in free or esterified form. This work proposes a two-dimensional liquid chromatography/high-resolution mass spectrometry (2D-LC-HRMS) method for the simultaneous analysis of triterpenic alcohols, free sterols and steryl esters. A reversed phase liquid chromatography (RPLC)-RPLC coupling was performed through a multiple heart-cutting interface equipped with an active solvent modulation (ASM) valve. Additionally, a selection valve was coupled to the 2D-LC system, allowing the simultaneous data acquisition from both dimensions in a single analysis. A simplified sample treatment based on solid phase extraction was also proposed to avoid tedious steps such as saponification or derivatization before gas chromatography analysis. To evaluate the content of these compounds in different olive oil categories, the proposed 2D-LC-HRMS system was applied to a set of samples from different commercial olive oil categories (extra virgin olive oil, virgin olive oil, olive oil, pomace olive oil) and sunflower oil. The results revealed significant differences in the distribution of free and esterified sterols of the analyzed samples, highlighting the free/esterified sterol ratio as a powerful tool to unveil olive oil fraud practices and fat manipulation.

Inhibitory Effects of New Epicatechin Oligomers on Nitric Oxide Production.

The primary aim of this research was to identify the structural characteristics of three newly derived procyanidins from cold plasma-treated (-)-epicatechin, known for their anti-inflammatory properties. The newly generated compounds were isolated through column chromatography, and their chemical structures were elucidated through spectroscopic data analyses, including both one-dimensional and two-dimensional nuclear magnetic resonance (NMR) and mass spectrometry (MS) techniques. Furthermore, their absolute configurations were determined via circular dichroism (CD) spectroscopy. The inhibitory activity of the isolated compounds on nitric oxide (NO) production and expression levels of inducible NO synthase (iNOS) in lipopolysaccharide (LPS)-induced RAW 264.7 macrophages was evaluated. Three new procyanidins-methylenetrisepicatechin (2), isomethylenetrisepicatechin (3), and methylenebisepicatechin (4)-along with two reported dimeric flavan-3-ols (5 and 6), were identified from plasma-treated (-)-epicatechin (1). The unique oligomerized products 2 and 3 linked by methylene bridges significantly suppressed both NO production and iNOS expression, demonstrating higher anti-inflammatory activities in LPS-stimulated RAW 264.7 cells compared with the parent compound. The newly oligomerized procyanidins have potential applications in the treatment of inflammatory diseases owing to their significant anti-inflammatory properties.

Proteomics Reveals Divergent Cardiac Inflammatory and Metabolic Responses After Inhalation of Ambient Particulate Matter With or Without Ozone.

Inhalation of ambient particulate matter (PM) and ozone (O3) has been associated with increased cardiovascular morbidity and mortality. However, the interactive effects of PM and O3 on cardiac dysfunction and disease have not been thoroughly examined, especially at a proteomic level. The purpose of this study was to identify and compare proteome changes in spontaneously hypertensive (SH) rats co-exposed to concentrated ambient particulates (CAPs) and O3, with a focus on investigating inflammatory and metabolic pathways, which are the two major ones implicated in the pathophysiology of cardiac dysfunction. For this, we measured and compared changes in expression status of 9 critical pro- and anti-inflammatory cytokines using multiplexed ELISA and 450 metabolic proteins involved in ATP production, oxidative phosphorylation, cytoskeletal organization, and stress response using two-dimensional electrophoresis (2-DE) and mass spectrometry (MS) in cardiac tissue of SH rats exposed to CAPs alone, O3 alone, and CAPs + O3. Proteomic expression profiling revealed that CAPs alone, O3 alone, and CAPs + O3 differentially altered protein expression patterns, and utilized divergent mechanisms to affect inflammatory and metabolic pathways and responses. Ingenuity Pathway Analysis (IPA) of the proteomic data demonstrated that the metabolic protein network centered by gap junction alpha-1 protein (GJA 1) was interconnected with the inflammatory cytokine network centered by nuclear factor kappa beta (NF-kB) potentially suggesting inflammation-induced alterations in metabolic pathways, or vice versa, collectively contributing to the development of cardiac dysfunction in response to CAPs and O3 exposure. These findings may enhance understanding of the pathophysiology of cardiac dysfunction induced by air pollution and provide testable hypotheses regarding mechanisms of action.

Automated compound speciation, cluster analysis, and quantification of organic vapors and aerosols using comprehensive two-dimensional gas chromatography and mass spectrometry

Abstract. The advancement of analytical techniques, such as comprehensive two-dimensional gas chromatography coupled with mass spectrometry (GC×GC–MS), enables the efficient separation of complex organics. Developing innovative methods for data processing and analysis is crucial to unlock the full potential of GC×GC–MS in understanding intricate chemical mixtures. In this study, we proposed an innovative method for the semi-automated identification and quantification of complex organic mixtures using GC×GC–MS. The method was formulated based on self-constructed mass spectrum patterns and the traversal algorithms and was applied to organic vapor and aerosol samples collected from the tailpipe emissions of heavy-duty diesel vehicles and the ambient atmosphere. Thousands of compounds were filtered, speciated, and clustered into 26 categories, including aliphatic and cyclic hydrocarbons, aromatic hydrocarbons, aliphatic oxygenated species, phenols and alkylphenols, and heteroatom-containing species. The identified species accounted for over 80 % of all the eluted chromatographic peaks at the molecular level. A comprehensive analysis of quantification uncertainty was undertaken. Using representative compounds, quantification uncertainties were found to be less than 37.67 %, 22.54 %, and 12.74 % for alkanes, polycyclic aromatic hydrocarbons (PAHs), and alkyl-substituted benzenes, respectively, across the GC×GC space, excluding the first and the last time intervals. From a source apportionment perspective, adamantane was clearly isolated as a potential tracer for heavy-duty diesel vehicle (HDDV) emissions. The systematic distribution of nitrogen-containing compounds in oxidized and reduced valences was discussed, and many of them served as critical tracers for secondary nitrate formation processes. The results highlighted the benefits of developing self-constructed models for the enhanced peak identification, automated cluster analysis, robust uncertainty estimation, and source apportionment and achieving the full potential of GC×GC–MS in atmospheric chemistry.

An integrated multi-omics analysis of the effects of the food processing-induced contaminant 2-monochloropropane-1,3-diol (2-MCPD) in rat heart

Many foods including edible oils contain 2-monochloropropane-1,3-diol (2-MCPD), a processing-induced chemical contaminant. Cardiotoxic effects have been shown to result from oral 2-MCPD exposure in rodents, but the underlying mechanisms of action remain poorly understood. We undertook a comprehensive multi-omics approach to assess changes at the transcriptomic, proteomic, and oxylipin levels in heart tissues from male F344 rats that were exposed to 0 or 40 mg/kg BW/day of 2-MCPD in the diet for 90 days, in a regulatory compliant rodent bioassay. Heart tissues were collected for RNA sequencing, quantitative PCR analysis, proteomic analysis via two-dimensional gel electrophoresis and mass spectrometry, and targeted lipidomic profiling by high-performance liquid chromatography–tandem mass spectrometry (HPLC–MS/MS). Transcriptomic and proteomic data analyses revealed upregulation of immune/inflammatory response processes and downregulation of energy metabolism and cardiac structure and functions. Among differentially expressed gene–protein pairs, coronin-1A, a key leukocyte-regulating protein, emerged as markedly up-regulated. Oxylipin profiling highlighted a selective suppression of docosahexaenoic acid-derived metabolites, suggesting a disruption in cardioprotective lipid pathways. These findings suggest that 2-MCPD disrupts homeostasis through inflammatory activation and suppression of metabolic and cardiac function. This research provides insights into 2-MCPD's cardiotoxicity, emphasizing the need for further studies to support hazard characterization.

A Proteomic Study on Seed Germination of Nitraria roborowskii Kom.

Owing to the dormancy of the seeds of Nitraria roborowskii Kom., which results in a low germination rate in nature, germination takes a long time, and natural regeneration is difficult. Therefore, there is a need to study the molecular mechanism by which the seeds of N. roborowskii release dormancy. In this study, the differentially expressed proteins of N. roborowskii seeds before and after dormancy and germination were quantitatively and qualitatively analyzed via two-dimensional high-performance liquid chromatography tandem mass spectrometry (LC–MS) and TMTTM. Differentially expressed proteins from dormant and germinated seeds were characterized and enriched via bioinformatics to determine the functions and pathways of the differentially expressed proteins. The results revealed that seed dormancy was regulated by multiple metabolic pathways, including protein synthesis, nutrient utilization and phytohormone signal transduction pathways. A comparison of the dormant and germinated N. roborowskii seed samples revealed 1082 differentially expressed proteins with FC ≥ 1.5 and p values ≤ 0.05, among which 191 proteins were upregulated and 891 proteins were downregulated in the seeds of the germinated group, and proteins more closely related to the key genes of the germinated N. roborowskii seeds were involved in the activity of D-threo-aldose 1-dehydrogenase. Four proteins (WD40, cystatin, AMP binding protein, and helicase) were involved in the positive regulation of seed germination. The release of N. roborowskii seed dormancy is a complex biological process involving cell differentiation, formation, cellular transport, signaling and resistance, etc. The interactions of multiple metabolic pathways, such as carbon fixation, glycolysis/gluconeogenesis, the pentose phosphate pathway, endoplasmic reticulum protein processing and pyruvic acid metabolism in photosynthetic organisms, constitute a complex regulatory mechanism for dormancy release.

Abstract P100: TRPM7 deficiency amplifies aldosterone signalling cardiac fibroblasts

Introduction: Transient Receptor Potential Melastatin 7 (TRPM7) channel is a channel bound to a kinase domain that influences cellular Mg 2+ with an important role in inflammatory response and cell metabolism. TRPM7 is regulated by aldosterone. Here, we investigated the importance of TRPM7-Mg2+ in pro-fibrotic responses and oxidative stress in cardiac fibroblasts (CF) in the context of hypertension and organ damage induced by aldosterone. Methods: Wild-type (WT) and TRPM7-deficient (M7+/Δ) mice were treated with aldosterone (600µg/Kg/day) plus NaCl (1% drinking water), 4 weeks. Mechanisms were investigated in primary culture of CF. Ca 2+ and Mg 2+ influx was assessed by fluorescence microscopy and flow cytometry. Gene and protein expression was assessed by real-time PCR and immunoblotting. Proteomic analysis was performed in two-dimensional liquid chromatography and mass spectrometry (LC/LC-MS/MS). Results: M7+/Δ mice exhibited reduced tissue [Mg 2+ ] (28%) and increased cardiac collagen deposition (2-fold). Aldosterone-induced fibrosis and hypertension were enhanced in M7+/Δ. CF M7+/Δ had reduced aldosterone-induced calcium influx (136±6 vs WT:166±7) and Mg 2+ influx (1.05±0.05 vs WT 1.14±0.02). CF M7+/Δ exhibit increased expression of calpain-1(300%), α-SMA(80%), collagen-1 (50%), mineralocorticoid receptor target proteins ENaC(70%) and SGK1(30%) and reduced proliferation(33%) vs WT(p<0.05). Aldosterone reduced TRPM7 (44%) and increased expression of ENaC (150%) and collagen-1 (93%) in CF WT to similar levels observed in CF M7+/Δ. CF M7+/Δ exhibit increased Nox2(70%), Nox4(120%) and ROS production (1,362 vs WT: 899 RLU/mg protein). Increased mRNA for the antioxidant catalase, NQO1 and Prdx1 (1.7-2.6-fold) was found in M7+/Δ CF. Mg 2+ supplementation normalised Ca 2+ and Mg 2+ influx, proliferation and expression of SGK1, Nox4, catalase and NQO1, whereas other effects might be mediated by the kinase domain. Proteomic analysis showed that CF M7+/Δ exhibit reduced expression of proteins related to cell migration and proliferation (Tnc, Cdcc80, Crip1, Ggt5) cell cycle and differentiation (AnxA8, Rpl22, Prickle2) and cell metabolism (Marcks, Mtab, Ces1d, Serpina3n, Afap1l1). Conclusion: Our findings demonstrate that in aldosterone-treated mice TRPM7 expression and tissue Mg 2+ levels are decreased. These processes are associated with cardiac fibrosis and oxidative stress. Our findings suggest a cardio-protective role for TRPM7/Mg2+ in aldosterone-induced hypertension.

Systematic Characterization of Sesquiterpenes from Dendrobium nobile through Offline Two-Dimensional Chromatography Tandem Mass Spectrometry and Target Isolation.

Dendrobium nobile is a species of the genus Dendrobium that can be used as both a medicinal herb and healthy food. The sesquiterpenes in D. nobile have attracted extensive attention in recent years. In this study, Amide × RP offline two-dimensional chromatography separation tandem high-resolution mass spectrometry combined with GNPS (Global Natural Product Social Molecular Networking) was developed for the characterization of sesquiterpenes in D. nobile. After first-dimensional amide separation, the 70% ethanol extract of D. nobile was divided into 40 fractions, which were analyzed by second-dimensional reverse-phase system separation and LTQ-Orbitrap detection. The raw data was imported into the GNPS, resulting in the efficient clustering of similar substances. Finally, 594 sesquiterpene compounds were characterized, and 25 compounds were isolated based on molecular network analysis, including six new compounds. In vitro bioassays, the isolated compounds decreased NO production in the LPS-induced microglial BV-2 cell model and the content of MDA in PC12 cells, demonstrating neuroprotective activity. These findings unraveled the underlying material and provided valuable insights into the quality control of D. nobile.

Numerical modeling of alkali metal heat pipes

Heat pipe cooled reactors passively transfer heat from the core to the energy conversion system through alkali metal heat pipes. Further studies of the heat transfer characteristics of alkali metal heat pipes are needed to develop heat pipe cooled reactors. This work used a two-dimensional heat and mass transfer model of an alkali metal heat pipe. The flow field was validated against CFD predictions which showed that the model has less than 10 % errors in the velocity distribution and less than 5 % errors in the pressure distribution. A comparison of the predictions with experimental data in the literature indicated that the predicted wall temperature error was within 30 °C. This model was then used to analyze four factors that affect heat transfer in sodium heat pipes. The simulations show that higher heat fluxes shorten the startup time by approximately 70 % but significantly increase the operating temperature. The heat flux distribution significantly affects the evaporator temperature distribution. The heat transfer boundary condition on the condenser’s outer surface mainly affects the operating temperature and startup time. Increasing the heat pipe length-to-diameter ratio with a fixed heat flux increases the operating temperature with the increase proportional to the heat flux. This model provides accurate simulations of sodium heat pipes for various heat transfer boundary conditions. The simulations provide a reference for the selection of working conditions for heat pipe operation instability experiments.