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Suzuki, Y.

Publications and source records attributed to Suzuki, Y..

At least 109 records · Page 6Linked to original sources

Antiviral effect of candies containing persimmon-derived tannin against SARS-CoV-2 delta strain

Inactivation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in the mouth has the potential to reduce the spread of coronavirus disease 2019 (COVID-19) because the virus is readily transmitted by dispersed saliva. Persimmon-derived tannin has strong antioxidant and antimicrobial activity owing to its strong adhesiveness to proteins, and it also exhibited antiviral effects against non-variant and alpha variant SARS-CoV-2 in our previous study. In this report, we first demonstrated the antiviral effects of persimmon-derived tannin against the delta variant of SARS-CoV-2 in vitro via the plaque assay method. We then examined the effects of candy containing persimmon-derived tannin. Our plaque assay results show that saliva samples provided by healthy volunteers while they were eating tannin-containing candy remarkably suppressed the virus titers of the SARS-CoV-2 delta variant. In addition, we found that the SARS-CoV-2 viral load in saliva from patients with COVID-19 that was collected immediately after they had eaten the tannin-containing candy was below the level of detection by PCR for SARS-CoV-2. These data suggest that adding persimmon-derived tannin to candy and holding such candy in the mouth is an effective method by which to inactivate the SARS-CoV-2 in saliva, and the application of this approach has potential for inhibiting the transmission of COVID-19.

microbiology↗

Murine breast cancers disorganize the liver transcriptome in zonated manners

The spatially organized gene expression program within the liver specifies hepatocyte functions according to their relative distances to the bloodstream (i.e., zonation), contributing to liver homeostasis. Despite the knowledge that solid cancers remotely disrupt liver homeostasis, it remains unexplored whether solid cancers affect liver zonation. Here, using spatial transcriptomics, we thoroughly investigate the abundance and zonation of hepatic genes in cancer-bearing mice. We find that breast cancers affect liver zonation in various distinct manners depending on biological pathways. Aspartate metabolism and triglyceride catabolic processes retain relatively intact zonation patterns, but the zonation of xenobiotic catabolic process genes exhibits a strong disruption. The acute phase response is induced in zonated manners. Furthermore, we demonstrate that breast cancers activate innate immune cells in particular neutrophils in distinct zonated manners, rather than in a uniform fashion within the liver. Collectively, breast cancers disorganize hepatic transcriptomes in zonated manners, thereby disrupting zonated functions of the liver.

cancer biology↗

Use of the particle agglutination/particle agglutination-inhibition test for antigenic analysis of SARS-CoV-2

The antigenicity of SARS-CoV-2 is a critical issue for the effectiveness of the vaccine, and thus it should be phenotypically evaluated by serological assays as new field isolates emerge. The hemagglutination/hemagglutination-inhibition (HA/HI) tests are well-known as a representative method for antigenic analysis of influenza viruses, but SARS-CoV-2 is unlikely to agglutinate to human or guinea pig red blood cells. Therefore, the antigenic analysis requires complicated enzyme-linked immunosorbent assay (ELISA) or cell-based assays such as the microneutralization assay. In this study, we developed the particle agglutination/particle agglutination-inhibition (PA/PAI) test to easily and rapidly quantify the virus and antibody using human angiotensin-converting enzyme 2 (hACE2)-bound latex beads. The PA titer was positively correlated with the plaque-forming units. The PAI titer using post-infection Syrian hamster antisera clearly revealed the antigenic difference between the omicron and previous variants. The results show the PAI test is useful for easy and rapid antigenic analysis of SARS-CoV-2.

microbiology↗

Cryo-EM analyses of wild-type and oncogenic KIT mutants reveal structural oncogenic plasticity and a novel Achilles heel for therapeutic intervention

The receptor tyrosine kinase KIT and its ligand SCF are required for the development of hematopoietic stem cells, germ cells, and other cells. A variety of human cancers, such as acute myeloid leukemia and mast cell leukemia, are driven by somatic gain-of-function KIT mutations. Here, we report cryo-EM structural analyses of full-length wild-type and two oncogenic KIT mutants, which show that the symmetric arrangement of ligand-occupied KIT dimers is converted into asymmetric D5 homotypic contacts juxtaposing the plasma membrane. Mutational analysis of KIT reveals in D5 region an "Achilles heel" for therapeutic intervention. A ligand-sensitized oncogenic KIT mutant exhibits a more comprehensive and stable D5 asymmetric conformation. A constitutively active ligand-independent oncogenic KIT mutant adopts a V-shaped conformation solely held by D5-mediated contacts. SCF binding to this mutant fully restores the conformation of wild-type KIT dimers, revealing an unexpected structural plasticity of oncogenic mutants that may offer new therapeutic modality.

biochemistry↗

intra-single cell sequencing (iSCseq) spotlights transcriptomic and epigenetic heterogeneity inside multinucleated osteoclast

Single-cell RNA-seq (scRNA-seq) has clarified cellular heterogeneity within cell populations. However, scRNA-seq and spatial transcriptomics cannot capture the dynamic transcriptomic changes inside living cells. To decode subcellular gene expression, we developed intra-single cell sequencing (iSCseq), a novel approach that combines confocal imaging, repeatedly picking up cellular components inside living cells, and next-generation sequencing (intra single-cell RNA-seq; iSCseq). iSCseq illustrated the subcellular heterogeneity of gene expression. iSCseq revealed not only multiple differentiation stages embedded in the same cell, but also physical cytoskeletal connections, physiological activity of mitochondria, and intracellular calcium, as confirmed by transcriptomic evidence. Inclusive iSCseq with in vivo scRNA-seq datasets identified new osteoclast subsets in physiological and pathological bones. Network analysis with centrality provided insights into the connection between subcellular components, and clearly divided differentiation and fusion processes in multinucleation. The iSCseq approach has the potential to enhance cell biology at subcellular resolution and identify new therapeutic targets. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=200 SRC="FIGDIR/small/506360v4_ufig1.gif" ALT="Figure 1"> View larger version (73K): org.highwire.dtl.DTLVardef@115c1d8org.highwire.dtl.DTLVardef@1695ad2org.highwire.dtl.DTLVardef@1c9d257org.highwire.dtl.DTLVardef@1107ddb_HPS_FORMAT_FIGEXP M_FIG C_FIG In briefintra-single cell sequencing (iSCseq) enhances single-cell technology by combining live cell imaging, subcellular sampling from living cells and sequencing, offering deeper insights into cell functions and pathology at subcellular resolution through inclusive analysis with scRNA-seq and advanced centrality-focused network analysis. HighlightsO_LIintra-single cell sequencing (iSCseq) clarifies subcellular heterogeneity C_LIO_LIiSCseq connects morphological and physiological features with transcriptome C_LIO_LIInclusive iSCseq unveils osteoclast subsets in physiological and pathological bones C_LIO_LILinkage at subcellular resolution reveals key players in characteristic fusion C_LI

genomics↗

Cardiac neural crest lineage diversity and underlying gene regulatory networks revealed by multimodal analysis

Neural crest cells (NCCs), a multipotent stem cell population, contribute to cardiac development as a source of the outflow septum, vascular smooth muscle and semilunar valves. However, genetic programs underlying lineage diversification of cardiac NCCs remain largely unknown. Using single-cell (sc) and spatial transcriptomics, we demonstrate multiple NCC subpopulations with distinct gene expression signatures; smooth muscle(-like), non-muscle mesenchymal, and Schwann cell progenitor/melanoblast-like cells. Integrative scRNA-seq and scATAC-seq analyses predict lineage trajectories starting from immature NCCs, which bifurcate into smooth muscle(-like) and non-muscle mesenchymal lineages in association with hierarchical transcription factor networks. Combinatory analyses with Cre-mediated genetic lineage tracing characterize intermediate NCCs at the bifurcation as Sox9+/Scx+ tendon and cartilage progenitor-like cells with genetic programs, some of which are common to skeletal tissues whereas others are unique to cardiac NCCs. These findings provide a basis for understanding the roles of NCCs in cardiac development and pathogenesis particularly associated with calcification.

developmental biology↗

Automatic Sleep Stage Classification with Optimized Selection of EEG Channels

Visual inspection of Polysomnography (PSG) recordings by sleep experts based on established guidelines has been the gold standard in sleep stage classification. This approach is expensive, time consuming and mostly limited to experimental research and clinical cases of major sleep disorders. Various automatic approaches to sleep scoring have been emerging in the past years and are opening the way to a quick computational assessment of sleep architecture that may find its way to the clinics. With the hope to make sleep scoring a fully automated process in the clinics, we report here an ensemble algorithm that aims at not only predicting sleep stages but of doing so with an optimized minimal number of EEG channels. For that, we combine a genetic algorithm based optimization with a classification framework that minimizes the number of channels used by the machine learning algorithm to quantify sleep stages. This resulted in a scoring with an F1 score of 0.793 for the fully automatic model and 0.806 for the model trained on 10 percent of the unseen subject, both with only 3 EEG channels. The ensemble algorithm is based on a combination of extremely randomized trees and MiniRocket classifiers. The algorithm was trained, validated and tested on night sleep PSG data collected from 7 subjects. The novelty of our approach lies on the use of the minimum information needed for automated sleep scoring, based on a systematic search that concurrently selects the optimal-minimum number of EEG channels and the best performing features for the machine learning classifier. The optimization framework presented in this work may enable new designs for sleep scoring devices suited to studies in the comfort of the homes, easily and inexpensively and in this way facilitate experimental and clinical studies in large populations.

neuroscience↗

The contribution of Kaposis sarcoma-associated herpesvirus ORF7 and its zinc-finger motif to viral genome cleavage and capsid formation

Kaposis sarcoma-associated herpesvirus (KSHV) is the causative agent of endothelial and B cell malignancies. During KSHV lytic infection, lytic-related proteins are synthesized, viral genomes are replicated as a tandemly repeated form, and subsequently, capsids are assembled. The herpesvirus terminase complex is proposed to package an appropriate genome unit into an immature capsid, by cleavage of terminal repeats (TRs) flanking tandemly linked viral genomes. Although the mechanism of capsid formation in - and {beta}-herpesviruses are well-studied, in KSHV, it remains largely unknown. It has been proposed that KSHV ORF7 is a terminase subunit, and ORF7 harbors a zinc-finger motif, which is conserved among other herpesviral terminases. However, the biological significance of ORF7 is unknown. We previously reported that KSHV ORF17 is essential for the cleavage of inner scaffold proteins in capsid maturation, and ORF17 knockout (KO) induced capsid formation arrest between the procapsid and B-capsid stages. However, it remains unknown if ORF7-mediated viral DNA cleavage occurs before or after ORF17-mediated scaffold collapse. We analyzed the role of ORF7 during capsid formation using ORF7-KO-, ORF7&17-double-KO (DKO)-, and ORF7-zinc-finger motif mutant-KSHVs. We found that ORF7 acted after ORF17 in the capsid formation process, and ORF7-KO-KSHV produced incomplete capsids harboring non-spherical internal structures, which resembled soccer balls. This soccer ball-like capsid was formed after ORF17-mediated B-capsid formation. Moreover, ORF7-KO- and zinc-finger motif KO-KSHV failed to appropriately cleave the TR on replicated genome and had a defect in virion production. Thus, our data revealed that ORF7 contributes to terminase-mediated viral genome cleavage and capsid formation. IMPORTANCEIn herpesviral capsid formation, the viral terminase complex cleaves the TR sites on newly synthesized tandemly repeating genomes and inserts an appropriate genomic unit into an immature capsid. Herpes simplex virus 1 (HSV-1) UL28 is a subunit of the terminase complex that cleaves the replicated viral genome. However, the physiological importance of the UL28 homolog, KSHV ORF7, remains poorly understood. Here, using several ORF7-deficent KSHVs, we found that ORF7 acted after ORF17-mediated scaffold collapse in the capsid maturation process. Moreover, ORF7 and its zinc-finger motif were essential for both cleavage of TR sites on the KSHV genome and virus production. ORF7-deficient KSHVs produced incomplete capsids that resembled a soccer ball. To our knowledge, this is the first report showing ORF7-KO-induced soccer ball-like capsids production and ORF7 function in the KSHV capsid assembly process. Our findings provide insights into the role of ORF7 in KSHV capsid formation.

microbiology↗

Algorithmic design of 3D wireframe RNA polyhedra

We address the problem of de novo design and synthesis of nucleic acid nanostructures, a challenge that has been considered in the area of DNA nanotechnology since the 1980s and more recently in the area of RNA nanotechnology. Towards this goal, we introduce a general algorithmic design process and software pipeline for rendering 3D wireframe polyhedral nanostructures in single-stranded RNA. To initiate the pipeline, the user creates a model of the desired polyhedron using standard 3D graphic design software. As its output, the pipeline produces an RNA nucleotide sequence whose corresponding RNA primary structure can be transcribed from a DNA template and folded in the laboratory. As case examples, we design and characterize experimentally three 3D RNA nanostructures: a tetrahedron, a bipyramid and a prism. The design software is openly available, and also provides an export of the targeted 3D structure into the oxRNA molecular dynamics simulator for easy simulation and visualization.

bioengineering↗

In vivo transomic analyses of glucose-responsive metabolism in skeletal muscle reveal core differences between the healthy and obese states

Metabolic regulation in skeletal muscle is essential for blood glucose homeostasis. Obesity causes insulin resistance in skeletal muscle, leading to hyperglycemia and type 2 diabetes. In this study, we performed multiomic analysis of the skeletal muscle of wild-type (WT) and genetically obese (ob/ob) mice, and constructed regulatory transomic networks for metabolism after oral glucose administration. Our network revealed that metabolic regulation by glucose-responsive metabolites had a major effect on WT mice, especially carbohydrate metabolic pathways. By contrast, in ob/ob mice, much of the metabolic regulation by glucose-responsive metabolites was lost and metabolic regulation by glucose-responsive genes was largely increased, especially in carbohydrate and lipid metabolic pathways. We present some characteristic metabolic regulatory pathways found in central carbon, branched amino acids, and ketone body metabolism. Our transomic analysis will provide insights into how skeletal muscle responds to changes in blood glucose and how it fails to respond in obesity.

systems biology↗

Single-nucleotide substitution determines pollen production in Japanese cedar

Pollinosis, also known as pollen allergy or hay fever, is a global problem caused by pollen produced by various plant species1-6. The wind-pollinated Japanese cedar (Cryptomeria japonica) is the largest contributor to severe pollinosis in Japan, where increasing proportions of people have been affected in recent decades7. The MS4 (MALE STERILITY 4) locus of Japanese cedar controls pollen production, and its homozygous mutants (ms4/ms4) show abnormal pollen development after the tetrad stage and produce no mature pollen. In this study, we narrowed down the MS4 locus by fine mapping in Japanese cedar and found TKPR1 (TETRAKETIDE -PYRONE REDUCTASE) gene in this region. Transformation experiments using Arabidopsis thaliana showed that single-nucleotide substitution of CjTKPR1 determines pollen production. Broad conservation of TKPR1 beyond plant division could lead to the creation of pollen-free plant not only for Japanese cedar but also for broader plant species.

plant biology↗

Masculinizer-induced dosage compensation is achieved by transcriptional downregulation of both copies of Z-linked genes in the silkworm, Bombyx mori

Dosage compensation balances the expression of sex-chromosome-linked genes with autosome-linked genes in the heterogametic sex. The silkworm (Bombyx mori), a lepidopteran model insect, uses the female heterogametic WZ sex determination system. In B. mori, a Z-linked gene, Masculinizer (Masc), is the primary determinant of maleness and dosage compensation. However, it remains unknown whether one of the two Z chromosomes is inactivated or both Z chromosomes are suppressed in B. mori males. Hence, we performed transcriptome analysis using hybrids between two B. mori strains and analyzed the allele-specific expression (ASE) to solve the problem. The ASE analysis revealed that the genes located on the maternal and paternal Z chromosomes are transcriptionally upregulated in Masc knocked down males. Also, our results revealed that two Z chromosomes are transcriptionally downregulated in B. mori males as observed in Caenorhabditis elegans.

genetics↗

Tyrosine phosphorylation of mitofusin 2 regulates endoplasmic reticulum-mitochondria tethering

Contact sites between the mitochondria and endoplasmic reticulum (ER) regulate the exchange of lipids, Ca2+, and reactive oxygen species (ROS) across the two organelles. Mitofusin 2 (Mfn2) has been identified as one of the major components tethering these two organelles together. Several post-translational modifications (PTMs) of Mfn2 have been shown to modulate canonical (i.e., mitochondrial fusion) and non-canonical Mfn2 functions, such as mitophagy and activation of ER stress signaling. However, there is little information about whether any PTMs can regulate mitochondrial and ER tethering. Basal tyrosine phosphorylation of Mfn2 was detected by mass spectroscopy, but it is unknown whether Mfn2 is a substrate of mitochondria-localized tyrosine kinases. Here, we show that mitochondria-localized c-Src can phosphorylate the C-terminal tail of Mfn2, which decreases the distance between the mitochondria and ER and facilitates Ca2+ transfer from the ER to mitochondria, followed by changes in ROS generation and mitochondrial bioenergetics. Our findings suggest that tyrosine phosphorylation of Mfn2 may uniquely work to fine-tune ER-mitochondrial Ca2+ transport under physiological and pathological conditions.

cell biology↗

Conifer leaves have a peroxisomal oxidative decarboxylation path in the photorespiratory pathway

The photorespiratory pathway consists of enzymes operating in chloroplasts, mitochondria, and peroxisomes. Conifer leaves lack one of them, chloroplastic Gln synthetase, which questioned the current belief that the photorespiratory mechanism is identical between angiosperm C3 species and conifers. A photorespiratory-metabolite analysis of the leaves of 13 conifer and 14 angiosperm tree species revealed significant differences in the mean metabolite concentrations between the two taxonomic groups: the glycerate content on chlorophyll basis in conifer leaves was <1/10 that detected in angiosperm leaves, whereas the glycolate content was 1.6 times higher in conifer leaves. Glycerate is produced from Ser through an intermediate, hydroxypyruvate. To investigate the lower glycerate levels observed in conifer leaves, we performed experiments of 13C-labeled Ser feeding to the detached shoots of a conifer (Cryptomeria japonica) via the transpiration stream, and compared the labeling patterns of photorespiratory metabolites with those of an angiosperm (Populus nigra). Glycerate was most labeled in P. nigra, whereas glycolate was more labeled than glycerate in C. japonica. The photorespiration pathway involves H2O2-scavenging and H2O2-generating enzymes, catalase (CAT) and glycolate oxidase (GLO), respectively, which are the peroxisomal targeting enzymes in angiosperms. In contrast, database analyses of the peroxisomal targeting signal motifs and analyses of the peroxisomal fractions isolated from C. japonica leaves indicated that the conifer peroxisomes were not a major localization of CAT. These results suggest that the conifer photorespiration pathway has a bypass from Ser to glycolate via the decarboxylation of hydroxypyruvate, because of an imbalance between CAT and GLO activities in peroxisomes. One sentence summaryConifer peroxisome is not a major localization of catalase and yields a unique oxidative decarboxylation path in the photorespiratory pathway.

plant biology↗

Single mutation makes Escherichia coli an insect mutualist

We report an experimental system in which Escherichia coli evolves into an insect mutualist. When the essential gut symbiont of the stinkbug Plautia stali was replaced by E. coli, a few survivor insects exhibited specific localization and vertical transmission of E. coli. Through trans-generational maintenance with P. stali, several hyper-mutating E. coli lines independently evolved hosts high adult emergence and improved body color. Such "mutualistic" E. coli lines exhibited independent mutations disrupting the carbon catabolite repression (CCR) global transcriptional regulator. Each of the mutations reproduced the mutualistic phenotypes when introduced into wild-type E. coli, confirming that the single CCR mutations instantly make E. coli an insect mutualist. Our discovery uncovers that evolution of elaborate mutualism can proceed more easily and rapidly than conventionally envisaged.

evolutionary biology↗

Fe(III)-dependent anaerobic methane-oxidizing activity in a deep underground borehole demonstrated by in-situ pressure groundwater incubation

The family Methanoperedenaceae archaea mediate anaerobic oxidation of methane (AOM) in various terrestrial environments. In this study, we newly developed a high-pressure laboratory incubation system by controlling hydraulic pressure ranging from ambient to 5 MPa. Using the system, we investigated groundwater from 214- and 249-m deep boreholes at Horonobe Underground Research Laboratory, Japan, where the high and low abundances of Methanoperedenaceae archaea have been revealed by genome-resolved metagenomics, respectively. We incubated the groundwater samples amended with or without amorphous Fe(III) as an electron acceptor and 13C-labelled methane at an in-situ pressure of 1.6 MPa. After three to seven-day incubation, AOM activities were not detected from the 249-m deep groundwater but from the 214-m deep groundwater. The AOM rates were 93.7 {+/-} 40.6 and 27.7 {+/-} 37.5 nM/day with and without Fe(III) amendment. To clarify the differences in AOM activity between the 214- and 249-m deep groundwater samples, we characterized Fe(III) contents in suspended particulates collected by filtration. The particulates were not visible in the 249-m deep groundwater on the filter, while they were abundant and contained Fe(III)-bearing phyllosilicates in the 214-m deep groundwater. These results support the in-situ activity of Fe(III)-dependent AOM in the deep subsurface borehole.

microbiology↗

NeoRdRp: A comprehensive dataset for identifying RNA-dependent RNA polymerase of various RNA viruses from metatranscriptomic data

RNA viruses are distributed throughout various environments, and most RNA viruses have recently been identified by metatranscriptome sequencing. However, due to the high nucleotide diversity of RNA viruses, it is still challenging to identify novel RNA viruses from metatranscriptome data. To overcome this issue, we created a dataset of RNA-dependent RNA polymerase (RdRp) domains that are essential for all RNA viruses belonging to Orthornavirae. Genes with RdRp domains from various RNA viruses were clustered based on their amino acid sequence similarity. For each cluster, a multiple sequence alignment was generated, and a hidden Markov model (HMM) profile was created if the number of sequences was greater than three. We further refined the 426 HMM profiles by detecting the RefSeq RNA virus sequences and subsequently combined the hit sequences with the RdRp domains. As a result, a total of 1,182 HMM profiles were generated from 12,502 RdRp domain sequences, and the dataset was named NeoRdRp. Almost all NeoRdRp HMM profiles successfully detected RdRp domains, specifically in the UniProt dataset. Furthermore, we compared the NeoRdRp dataset with two previously reported methods for RNA virus detection using metatranscriptome sequencing data. Our methods successfully identified most of the RNA viruses in the datasets; however, some RNA viruses were not detected, as in the cases of the other two methods. The NeoRdRp can be repeatedly improved by adding new RdRp sequences and is applicable as a system for detecting various RNA viruses from diverse metatranscriptome data.

microbiology↗

Dynamics of peripheral blood flow across sleep stages

Study ObjectivesPulse rate variability (PRV) derived from peripheral blood flow has been reported as a surrogate parameter for heart rate variability (HRV). However, there are currently no studies reporting systematic comparisons of PRV with HRV in a normal sleep state. Whether PRV can provide similar information regarding sleep stages remains unclear. Peripheral blood flow may also be modulated differently across sleep stages. Thus, we aimed to investigate blood flow dynamics and compare PRV with HRV across sleep stages to see if blood flow can provide further information about sleep stages. MethodsWe performed electrocardiography and simultaneously measured blood flow from the right index finger and ear concha of 45 healthy participants (13 women; mean age, 22.5 {+/-} 3.4 years) during one night of sleep. Time-domain, frequency-domain, and non-linear indices of PRV/HRV, and time- and frequencydomain blood flow parameters were calculated. ResultsFinger-PRV results showed similar patterns to HRV results for most parameters. Finger-blood flow parameters in the time and frequency domains also showed information about the different sleep stages. Further, both finger- and ear-blood flow results showed 0.2-0.3 Hz oscillations that varied with sleep stages, with a significant increase in N3, suggesting a modulation (of respiration) within this frequency band. ConclusionsThese results suggest that PRV can provide as much information as HRV for different sleep stages. Furthermore, the results show that blood flow + PRV could be more advantageous than HRV alone in the assessment of the sleep state and related autonomic nervous activity. Statement of SignificanceThe research provides comprehensive information on peripheral blood flow (BF) activity across sleep stages for the first time, as the major novelty of our work. The second contribution is a systematic study comparing BF-derived pulse rate variability (PRV) with heart rate variability across sleep stages in a normal sleep state. We believe that our work makes a significant contribution to the literature because it provides comprehensive information on the potential of BF+PRV as a new biomarker for assessing the sleep state. Further, this study contributes to developing a more convenient method of assessing the sleep state in the clinical and home/work setting.

physiology↗