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1.
Adv Sci (Weinh) ; : e2402235, 2024 Jul 04.
Article in English | MEDLINE | ID: mdl-38965704

ABSTRACT

Exsolution of metal nanoparticles (NPs) on perovskite oxides has been demonstrated as a reliable strategy for producing catalyst-support systems. Conventional exsolution requires high temperatures for long periods of time, limiting the selection of support materials. Plasma direct exsolution is reported at room temperature and atmospheric pressure of Ni NPs from a model A-site deficient perovskite oxide (La0.43Ca0.37Ni0.06Ti0.94O2.955). Plasma exsolution is carried out within minutes (up to 15 min) using a dielectric barrier discharge configuration both with He-only gas as well as with He/H2 gas mixtures, yielding small NPs (<30 nm diameter). To prove the practical utility of exsolved NPs, various experiments aimed at assessing their catalytic performance for methanation from synthesis gas, CO, and CH4 oxidation are carried out. Low-temperature and atmospheric pressure plasma exsolution are successfully demonstrated and suggest that this approach could contribute to the practical deployment of exsolution-based stable catalyst systems.

2.
Phys Eng Sci Med ; 2024 Jul 02.
Article in English | MEDLINE | ID: mdl-38954380

ABSTRACT

Recognizing user intention in reach-to-grasp motions is a critical challenge in rehabilitation engineering. To address this, a Machine Learning (ML) algorithm based on the Extreme Learning Machine (ELM) was developed for identifying motor actions using surface Electromyography (sEMG) during continuous reach-to-grasp movements, involving multiple Degrees of Freedom (DoFs). This study explores feature extraction methods based on time domain and autoregressive models to evaluate ELM performance under different conditions. The experimental setup encompassed variations in neuron size, time windows, validation with each muscle, increase in the number of features, comparison with five conventional ML-based classifiers, inter-subjects variability, and temporal dynamic response. To evaluate the efficacy of the proposed ELM-based method, an openly available sEMG dataset containing data from 12 participants was used. Results highlight the method's performance, achieving Accuracy above 85%, F-score above 90%, Recall above 85%, Area Under the Curve of approximately 84% and compilation times (computational cost) of less than 1 ms. These metrics significantly outperform standard methods (p < 0.05). Additionally, specific trends were found in increasing and decreasing performance in identifying specific tasks, as well as variations in the continuous transitions in the temporal dynamics response. Thus, the ELM-based method effectively identifies continuous reach-to-grasp motions through myoelectric data. These findings hold promise for practical applications. The method's success prompts future research into implementing it for more reliable and effective Human-Machine Interface (HMI) control. This can revolutionize real-time upper limb rehabilitation, enabling natural and complex Activities of Daily Living (ADLs) like object manipulation. The robust results encourages further research and innovative solutions to improve people's quality of life through more effective interventions.

3.
Anal Bioanal Chem ; 416(18): 4071-4082, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38958703

ABSTRACT

The study of glycoproteomics presents a set of unique challenges, primarily due to the low abundance of glycopeptides and their intricate heterogeneity, which is specific to each site. Glycoproteins play a crucial role in numerous biological functions, including cell signaling, adhesion, and intercellular communication, and are increasingly recognized as vital markers in the diagnosis and study of various diseases. Consequently, a quantitative approach to glycopeptide research is essential. One effective strategy to address this need is the use of multiplex glycopeptide labeling. By harnessing the synergies of 15N metabolic labeling via the isotopic detection of amino sugars with glutamine (IDAWG) technique for glycan parts and tandem mass tag (TMT)pro labeling for peptide backbones, we have developed a method that allows for the accurate quantification and comparison of multiple samples simultaneously. The adoption of the liquid chromatography-synchronous precursor selection (LC-SPS-MS3) technique minimizes fragmentation interference, enhancing data reliability, as shown by a 97% TMT labeling efficiency. This method allows for detailed, high-throughput analysis of 32 diverse samples from 231BR cell lines, using both 14N and 15N glycopeptides at a 1:1 ratio. A key component of our methodology was the precise correction for isotope and TMTpro distortions, significantly improving quantification accuracy to less than 5% distortion. This breakthrough enhances the efficiency and accuracy of glycoproteomic studies, increasing our understanding of glycoproteins in health and disease. Its applicability to various cancer cell types sets a new standard in quantitative glycoproteomics, enabling deeper investigation into glycopeptide profiles.


Subject(s)
Glycopeptides , Isotope Labeling , Nitrogen Isotopes , Tandem Mass Spectrometry , Glycopeptides/analysis , Glycopeptides/metabolism , Humans , Nitrogen Isotopes/analysis , Tandem Mass Spectrometry/methods , Isotope Labeling/methods , Proteomics/methods , Cell Line, Tumor , Chromatography, Liquid/methods
4.
Curr Issues Mol Biol ; 46(6): 5777-5793, 2024 Jun 11.
Article in English | MEDLINE | ID: mdl-38921016

ABSTRACT

Traditional methodologies often fall short in addressing the complexity of biological systems. In this regard, system biology omics have brought invaluable tools for conducting comprehensive analysis. Current sequencing capabilities have revolutionized genetics and genomics studies, as well as the characterization of transcriptional profiling and dynamics of several species and sample types. Biological systems experience complex biochemical processes involving thousands of molecules. These processes occur at different levels that can be studied using mass spectrometry-based (MS-based) analysis, enabling high-throughput proteomics, glycoproteomics, glycomics, metabolomics, and lipidomics analysis. Here, we present the most up-to-date techniques utilized in the completion of omics analysis. Additionally, we include some interesting examples of the applicability of multi omics to a variety of biological systems.

5.
Nature ; 2024 Jun 26.
Article in English | MEDLINE | ID: mdl-38926574

ABSTRACT

Despite being the dominant force of nature on large scales, gravity remains relatively elusive to precision laboratory experiments. Atom interferometers are powerful tools for investigating, for example, Earth's gravity1, the gravitational constant2, deviations from Newtonian gravity3-6 and general relativity7. However, using atoms in free fall limits measurement time to a few seconds8, and much less when measuring interactions with a small source mass2,5,6,9. Recently, interferometers with atoms suspended for 70 s in an optical-lattice mode filtered by an optical cavity have been demonstrated10-14. However, the optical lattice must balance Earth's gravity by applying forces that are a billionfold stronger than the putative signals, so even tiny imperfections may generate complex systematic effects. Thus, lattice interferometers have yet to be used for precision tests of gravity. Here we optimize the gravitational sensitivity of a lattice interferometer and use a system of signal inversions to suppress and quantify systematic effects. We measure the attraction of a miniature source mass to be amass = 33.3 ± 5.6stat ± 2.7syst nm s-2, consistent with Newtonian gravity, ruling out 'screened fifth force' theories3,15,16 over their natural parameter space. The overall accuracy of 6.2 nm s-2 surpasses by more than a factor of four the best similar measurements with atoms in free fall5,6. Improved atom cooling and tilt-noise suppression may further increase sensitivity for investigating forces at sub-millimetre ranges17,18, compact gravimetry19-22, measuring the gravitational Aharonov-Bohm effect9,23 and the gravitational constant2, and testing whether the gravitational field has quantum properties24.

6.
Article in English | MEDLINE | ID: mdl-38739520

ABSTRACT

Robotic systems, such as Lokomat® have shown promising results in people with severe motor impairments, who suffered a stroke or other neurological damage. Robotic devices have also been used by people with more challenging damages, such as Spinal Cord Injury (SCI), using feedback strategies that provide information about the brain activity in real-time. This study proposes a novel Motor Imagery (MI)-based Electroencephalogram (EEG) Visual Neurofeedback (VNFB) system for Lokomat® to teach individuals how to modulate their own µ (8-12 Hz) and ß (15-20 Hz) rhythms during passive walking. Two individuals with complete SCI tested our VNFB system completing a total of 12 sessions, each on different days. For evaluation, clinical outcomes before and after the intervention and brain connectivity were analyzed. As findings, the sensitivity related to light touch and painful discrimination increased for both individuals. Furthermore, an improvement in neurogenic bladder and bowel functions was observed according to the American Spinal Injury Association Impairment Scale, Neurogenic Bladder Symptom Score, and Gastrointestinal Symptom Rating Scale. Moreover, brain connectivity between different EEG locations significantly ( [Formula: see text]) increased, mainly in the motor cortex. As other highlight, both SCI individuals enhanced their µ rhythm, suggesting motor learning. These results indicate that our gait training approach may have substantial clinical benefits in complete SCI individuals.


Subject(s)
Electroencephalography , Gait , Neurofeedback , Spinal Cord Injuries , Humans , Spinal Cord Injuries/rehabilitation , Spinal Cord Injuries/physiopathology , Neurofeedback/methods , Electroencephalography/methods , Male , Adult , Gait/physiology , Robotics , Imagination/physiology , Female , Gait Disorders, Neurologic/rehabilitation , Gait Disorders, Neurologic/etiology , Gait Disorders, Neurologic/physiopathology , Treatment Outcome , Middle Aged , Exoskeleton Device , Walking/physiology , Beta Rhythm , Imagery, Psychotherapy/methods
7.
Proteomics ; : e2300620, 2024 Apr 11.
Article in English | MEDLINE | ID: mdl-38602241

ABSTRACT

Mild cognitive impairment (MCI) is an early stage of memory loss that affects cognitive abilities with the aging of individuals, such as language or visual/spatial comprehension. MCI is considered a prodromal phase of more complicated neurodegenerative diseases such as Alzheimer's. Therefore, accurate diagnosis and better understanding of the disease prognosis will facilitate prevention of neurodegeneration. However, the existing diagnostic methods fail to provide precise and well-timed diagnoses, and the pathophysiology of MCI is not fully understood. Alterations of the serum N-glycoproteome expression could represent an essential contributor to the overall pathophysiology of neurodegenerative diseases and be used as a potential marker to assess MCI diagnosis using less invasive procedures. In this approach, we identified N-glycopeptides with different expressions between healthy and MCI patients from serum glycoproteins. Seven of the N-glycopeptides showed outstanding AUC values, among them the antithrombin-III Asn224 + 4-5-0-2 with an AUC value of 1.00 and a p value of 0.0004. According to proteomics and ingenuity pathway analysis (IPA), our data is in line with recent publications, and the glycoproteins carrying the identified N-sites play an important role in neurodegeneration.

8.
World Neurosurg ; 187: 114-121, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38636636

ABSTRACT

OBJECTIVE: Augmented reality (AR) and virtual reality (VR) technologies have been introduced to neurosurgery with the goal of improving the experience of human visualization. In recent years, the application of remote AR and VR has opened new horizons for neurosurgical collaboration across diverse domains of education and patient treatment. Herein, we aimed to systematically review the literature about the feasibility of this technology and discuss the technical aspects, current limitations, and future perspectives. METHODS: Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, 4 databases (PubMed, Embase, Scopus, and Cochrane Library) were queried for articles discussing the use of remote AR and VR technologies in neurosurgery. Data were collected in various fields, including surgery type, application type, subspecialty, software and hardware descriptions, haptic device utilization, visualization technology, internet connection, remote site descriptions, technical outcomes, and limitations. Data were summarized as counts and proportions and analyzed using IBM SPSS software. RESULTS: Our search strategy generated 466 records, out of which 9 studies satisfied the inclusion criteria. The majority of AR and VR applications were used in cranial procedures (77.8%), mainly in education (63.6%), followed by telesurgical assistance (18.2%), patient monitoring (9.1%), and surgical planning (9.1%). Local collaborations were established in 55.6% of the studies, while national and international partnerships were formed in 44.4% of the studies. AR was the main visualization technology, and 3G internet connection was predominantly used (27.5%). All studies subjectively reported the utility of remote AR and VR for real-time interaction. The major technical challenges and limitations included audiovisual latency, the requirement for higher-fidelity and resolution image reconstructions, and the level of proficiency of the patient with the software. CONCLUSIONS: The results from this systematic review suggest that AR and VR technologies are dynamically advancing to offer remote collaboration in neurosurgery. Although still incipient in development and with an imperative need for technical improvement, remote AR and VR hold a frontierless potential for patient monitoring, neurosurgical education, and long-distance surgical assistance.


Subject(s)
Augmented Reality , Neurosurgical Procedures , Virtual Reality , Humans , Neurosurgery/education , Neurosurgical Procedures/methods , Neurosurgical Procedures/trends
9.
BMC Plant Biol ; 24(1): 176, 2024 Mar 06.
Article in English | MEDLINE | ID: mdl-38448825

ABSTRACT

BACKGROUND: The microbiome plays a fundamental role in plant health and performance. Soil serves as a reservoir of microbial diversity where plants attract microorganisms via root exudates. The soil has an important impact on the composition of the rhizosphere microbiome, but greenhouse ornamental plants are commonly grown in soilless substrates. While soil microbiomes have been extensively studied in traditional agriculture to improve plant performance, health, and sustainability, information about the microbiomes of soilless substrates is still limited. Thus, we conducted an experiment to explore the microbiome of a peat-based substrate used in container production of Impatiens walleriana, a popular greenhouse ornamental plant. We investigated the effects of plant phenological stage and fertilization level on the substrate microbiome. RESULTS: Impatiens plants grown under low fertilization rates were smaller and produced more flowers than plants grown under optimum and high fertilization. The top five bacterial phyla present in the substrate were Proteobacteria, Actinobacteria, Bacteriodota, Verrucomicrobiota, and Planctomycetota. We found a total of 2,535 amplicon sequence variants (ASV) grouped into 299 genera. The substrate core microbiome was represented by only 1.8% (48) of the identified ASV. The microbiome community composition was influenced by plant phenological stage and fertilizer levels. Phenological stage exhibited a stronger influence on microbiome composition than fertilizer levels. Differential abundance analysis using DESeq2 identified more ASVs significantly affected (enriched or depleted) in the high fertilizer levels at flowering. As observed for community composition, the effect of plant phenological stage on microbial community function was stronger than fertilizer level. Phenological stage and fertilizer treatments did not affect alpha-diversity in the substrate. CONCLUSIONS: In container-grown ornamental plants, the substrate serves as the main microbial reservoir for the plant, and the plant and agricultural inputs (fertilization) modulate the microbial community structure and function of the substrate. The differences observed in substrate microbiome composition across plant phenological stage were explained by pH, total organic carbon (TOC) and fluoride, and across fertilizer levels by pH and phosphate (PO4). Our project provides an initial diversity profile of the bacteria occurring in soilless substrates, an underexplored source of microbial diversity.


Subject(s)
Impatiens , Microbiota , Fertilizers , Nutrients , Soil
10.
Am J Surg ; 231: 79-85, 2024 May.
Article in English | MEDLINE | ID: mdl-38492992

ABSTRACT

BACKGROUND: Subungual melanoma (SUM) is a rare tumor with historically poor outcomes. Thus, the benefit of proximal versus distal amputation in SUM remains unclear. METHODS: We performed a retrospective review of our prospectively-maintained institutional melanoma database, including SUM and non-subungual acral melanoma (AM) patients who underwent sentinel lymph node biopsy (SLNB) between 1999 and 2022. All SUMs had distal joint or proximal amputations. Primary endpoints were overall survival (OS) and recurrence free survival (RFS). Kaplan-Meier estimates, and Cox univariate and multivariate analyses were performed. Tests were repeated on propensity score matched (PSM) populations in a 2:1 ratio. RESULTS: 123 patients underwent resection with SLNB for SUM (n â€‹= â€‹27) and AM (n â€‹= â€‹96). Median follow-up was 9.2 years. Unadjusted median OS was 149.1 months for AM and 198.1 months for SUM. In the PSM comparison, median OS and RFS remained comparable between SUM and AM (149.5 months versus 198.1 months; p â€‹= â€‹0.612). Sentinel node positivity was associated with significantly worse overall survival outcome (Hazard Ratio 5.49; CI (1.59-18.97), p â€‹= â€‹0.007). In the PSM population, male sex was also associated with a significant hazard of death (HR 3.00, CI (1.03-8.71), p â€‹= â€‹0.043). Proximal amputations were associated with significantly worse OS (p â€‹< â€‹0.002) and RFS (p â€‹< â€‹0.01) compared to distal amputations in SUM. CONCLUSION: SUM was well-treated with distal amputations, and had better OS and RFS compared to SUM treated with proximal amputations. Sentinel lymph node status is an important prognostic factor for SUMs and AMs. SUMs can be treated similarly to AMs with comparably good long-term outcomes.


Subject(s)
Melanoma , Nail Diseases , Sentinel Lymph Node , Skin Neoplasms , Humans , Male , Melanoma/pathology , Sentinel Lymph Node Biopsy , Prognosis , Survival Rate , Skin Neoplasms/pathology , Sentinel Lymph Node/pathology , Retrospective Studies , Nail Diseases/pathology , Nail Diseases/surgery
12.
Environ Toxicol Pharmacol ; 106: 104381, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38311300

ABSTRACT

In recent decades, glyphosate and glyphosate-based herbicides (GBH) have been extensively used in agriculture all over the world. Initially, they were considered safe, but rising evidence suggests that these molecules reach the central nervous system producing metabolic, functional, and permanent alterations that impact cognition and behavior. This theoretical and non-systematic review involved searching, integrating, and analyzing preclinical evidence regarding the effects of acute, sub-chronic, and chronic exposure to glyphosate and GBH on cognition, behavior, neural activity, and development in adult and juvenile rodents following perinatal exposition. In addition, this review gathers the mechanisms underlying the neurotoxicity of glyphosate mediating cognitive and behavioral alterations. Furthermore, clinical evidence of the effects of exposition to GBH on human health and its possible link with several neurological disorders was revised.


Subject(s)
Herbicides , Neurotoxicity Syndromes , Adult , Humans , Female , Pregnancy , Glyphosate , Cognition , Neurotoxicity Syndromes/etiology , Herbicides/toxicity , Agriculture
13.
Cells ; 13(3)2024 Jan 31.
Article in English | MEDLINE | ID: mdl-38334658

ABSTRACT

Healthy human skin tissue is often used as a control for comparison to diseased skin in patients with skin pathologies, including skin cancers or other inflammatory conditions such as atopic dermatitis or psoriasis. Although non-affected skin from these patients is a more appropriate choice for comparison, there is a paucity of studies examining such tissue. This lack is exacerbated by the difficulty of processing skin tissue for experimental analysis. In addition, choosing a processing protocol for skin tissue which preserves cell viability and identity while sufficiently dissociating cells for single-cell analysis is not a trivial task. Here, we compare three digestion methods for human skin tissue, evaluating the cell yield and viability for each protocol. We find that the use of a sequential dissociation method with multiple enzymatic digestion steps produces the highest cell viability. Using single-cell sequencing, we show this method results in a relative increase in the proportion of non-antigen-presenting mast cells and CD8 T cells as well as a relative decrease in the proportion of antigen-presenting mast cells and KYNU+ CD4 T cells. Overall, our findings support the use of this sequential digestion method on freshly processed human skin samples for optimal cell yield and viability.


Subject(s)
Dermatitis, Atopic , Skin , Humans , Skin/pathology , T-Lymphocyte Subsets/pathology , Dermatitis, Atopic/pathology , Sequence Analysis, RNA , Digestion
14.
Methods Mol Biol ; 2762: 231-250, 2024.
Article in English | MEDLINE | ID: mdl-38315369

ABSTRACT

MS-target analyses are frequently utilized to analyze and validate structural changes of biomolecules across diverse fields of study such as proteomics, glycoproteomics, glycomics, lipidomics, and metabolomics. Targeted studies are commonly conducted using multiple reaction monitoring (MRM) and parallel reaction monitoring (PRM) techniques. A reliable glycoproteomics analysis in intricate biological matrices is possible with these techniques, which streamline the analytical workflow, lower background interference, and enhance selectivity and specificity.


Subject(s)
Metabolomics , Proteomics , Mass Spectrometry/methods , Proteomics/methods , Lipidomics , Glycomics/methods
15.
Methods Mol Biol ; 2762: 251-266, 2024.
Article in English | MEDLINE | ID: mdl-38315370

ABSTRACT

Targeted mass spectrometric analysis is widely employed across various omics fields as a validation strategy due to its high sensitivity and accuracy. The approach has been successfully employed for the structural analysis of proteins, glycans, lipids, and metabolites. Multiple reaction monitoring (MRM) and parallel reaction monitoring (PRM) have been the methods of choice for targeted structural studies of biomolecules. These target analyses simplify the analytical workflow, reduce background interference, and increase selectivity/specificity, allowing for a reliable quantification of permethylated N-glycans in complex biological matrices.


Subject(s)
Polysaccharides , Mass Spectrometry/methods , Polysaccharides/chemistry , Workflow
16.
Metabolites ; 14(1)2024 Jan 13.
Article in English | MEDLINE | ID: mdl-38248853

ABSTRACT

Glyphosate-based herbicides (GBHs) have gained extensive popularity in recent decades. For many years, glyphosate has been regarded as harmless or minimally toxic to mammals due to the absence of its primary target, the shikimic acid pathway in humans. Nonetheless, mounting evidence suggests that glyphosate may cause adverse health effects in humans via other mechanisms. In this study, we described the metabolomic changes in the serum of experimental rats exposed to chronic GBH using the highly sensitive LC-MS/MS technique. We investigated the possible relationship between chronic exposure to GBH and neurological disorders. Our findings suggest that chronic exposure to GBH can alter spatial learning memory and the expression of some important metabolites that are linked to neurophysiological disorders in young rats, with the female rats showing higher susceptibility compared to the males. This indicates that female rats are more likely to show early symptoms of the disorder on exposure to chronic GBH compared to male rats. We observed that four important metabolites (paraxanthine, epinephrine, L-(+)-arginine, and D-arginine) showed significant changes and involvement in neurological changes as suggested by ingenuity pathway analysis. In conclusion, our results indicate that chronic exposure to GBH can increase the risk of developing neurological disorders.

17.
Ann Surg Oncol ; 31(1): 577-593, 2024 Jan.
Article in English | MEDLINE | ID: mdl-37891454

ABSTRACT

BACKGROUND: The impact of cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS-HIPEC) on quality of life (QoL) for patients taking opioids and psychotropic medications preoperatively is unclear. METHODS: This study retrospectively reviewed a CRS-HIPEC single-center prospectively maintained database for 2012-2016. Demographics and clinical data on opioids/psychotropic medication use were collected via chart review. The study collected QoL outcomes at baseline, then 3, 6, and 12 months postoperatively via the Center for Epidemiologic Studies Depression Scale (CES-D), Brief Pain Inventory, Functional Assessment of Cancer Therapy, and 36-Item Short-Form Health Survey. Differences in QoL between the groups were calculated using repeated measures analysis of variance regression. Descriptive statistics and Kaplan-Meier analyses were performed. RESULTS: Of 388 patients, 44.8% were taking opioids/psychotropic medications preoperatively. At baseline, those taking opioids/psychotropic medications preoperatively versus those not taking these medications had significantly worse QoL. By 1 year postoperatively, the QoL measures did not differ significantly except for emotional functioning (e.g., no medications vs. opioids/psychotropic medications: CES-D, 5.6 vs. 10.1). Median survival did not differ significantly (opioids/psychotropic medications vs. no medications: 52.3 vs. 60.6 months; p = 0.66). At 1 year after surgery, a greater percentage of patients were taking opioids, psychotropic medications, or both than at baseline (63.2% vs. 44.8%; p < 0.001). CONCLUSION: Despite worse baseline QoL, patients who took opioids/psychotropic medications had QoL scores 1 year postoperatively similar to the scores of those who did not except in the emotional domains. These data point to the potential utility of a timed psychosocial intervention to enhance emotional adaptation and further support the role of CRS-HIPEC in improving QoL.


Subject(s)
Hyperthermia, Induced , Peritoneal Neoplasms , Humans , Hyperthermic Intraperitoneal Chemotherapy , Quality of Life , Combined Modality Therapy , Cytoreduction Surgical Procedures/adverse effects , Analgesics, Opioid/therapeutic use , Retrospective Studies , Hyperthermia, Induced/adverse effects , Peritoneal Neoplasms/therapy , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Survival Rate
18.
An Acad Bras Cienc ; 95(suppl 3): e20231268, 2023.
Article in English | MEDLINE | ID: mdl-38088643

ABSTRACT

Despite the enormous paleobotanical record on different islands of the Antarctic Peninsula, the evidence of insect activity associated with fossilized plants is scarce. Here we report the first evidence of insect-plant interaction from Cretaceous deposits, more precisely from a new locality at the Rip Point area, Nelson Island (Antarctic Peninsula). The macrofossil assemblage includes isolated Nothofagus sp. leaf impressions, a common component of the Antarctic paleoflora. Two hundred leaves were examined, of which 15 showed evidence of insect activity, displaying variations in size, shape, and preservation. Two types of interaction damage, galls and mines, were identified. A single specimen retained a circular scar recognized as galling scar, while meandering tracks were considered mines. These traces of herbivore insect activity, correspond to the oldest known record of this type of interaction of West Antarctica and the oldest record of insect-plant interaction in Nothofagus sp. reported so far.


Subject(s)
Cicatrix , Fossils , Animals , Antarctic Regions , Insecta , Plant Leaves
19.
Anal Chem ; 95(50): 18388-18397, 2023 12 19.
Article in English | MEDLINE | ID: mdl-38069741

ABSTRACT

Determination of the relative expression levels of the α2,3/α2,6-sialic acid linkage isomers on glycoproteins is critical to the analysis of various human diseases such as cancer, inflammation, and viral infection. However, it remains a challenge to separate and differentiate site-specific linkage isomers at the glycopeptide level. Some derivatization methods on the carboxyl group of sialic acid have been developed to generate mass differences between linkage isomers. In this study, we utilized chemical derivatization that occurred on the vicinal diol of sialic acid to separate linkage isomers on a reverse-phase column using a relatively short time. 2-Aminobenzamide (2AB) labeling derivatization, including periodate oxidation and reductive amination, took only ∼3 h and achieved high labeling efficiency (>90%). Within a 66 min gradient, the sialic acid linkage isomers of 2AB-labeled glycopeptides from model glycoproteins can be efficiently resolved compared to native glycopeptides. Two different methods, neuraminidase digestion and higher-energy collision dissociation tandem mass spectrometry (HCD-MS2) fragmentation, were utilized to differentiate those isomeric peaks. By calculating the diagnostic oxonium ion ratio of Gal2ABNeuAc and 2ABNeuAc fragments, significant differences in chromatographic retention times and in mass spectral peak abundances were observed between linkage isomers. Their corresponding MS2 PCA plots also helped to elucidate the linkage information. This method was successfully applied to human blood serum. A total of 514 2AB-labeled glycopeptide structures, including 152 sets of isomers, were identified, proving the applicability of this method in linkage-specific structural characterization and relative quantification of sialic acid isomers.


Subject(s)
N-Acetylneuraminic Acid , Tandem Mass Spectrometry , Humans , N-Acetylneuraminic Acid/chemistry , Tandem Mass Spectrometry/methods , Sialoglycoproteins , Liquid Chromatography-Mass Spectrometry , Chromatography, Liquid , Glycoproteins , Glycopeptides/analysis , Polysaccharides/chemistry
20.
Nat Commun ; 14(1): 8346, 2023 Dec 15.
Article in English | MEDLINE | ID: mdl-38102124

ABSTRACT

The triangular lattice antiferromagnet (TLAF) has been the standard paradigm of frustrated magnetism for several decades. The most common magnetic ordering in insulating TLAFs is the 120° structure. However, a new triple-Q chiral ordering can emerge in metallic TLAFs, representing the short wavelength limit of magnetic skyrmion crystals. We report the metallic TLAF Co1/3TaS2 as the first example of tetrahedral triple-Q magnetic ordering with the associated topological Hall effect (non-zero σxy(H = 0)). We also present a theoretical framework that describes the emergence of this magnetic ground state, which is further supported by the electronic structure measured by angle-resolved photoemission spectroscopy. Additionally, our measurements of the inelastic neutron scattering cross section are consistent with the calculated dynamical structure factor of the tetrahedral triple-Q state.

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