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Biology subjects

Sun, M.

Publications and source records attributed to Sun, M..

At least 19 recordsLinked to original sources

The diversity, evolution, and conservation of African plants

Africa hosts remarkable biodiversity across diverse biomes, yet its evolutionary history at continental-scale remains poorly understood. We integrate a time-calibrated phylogeny covering 93% of African vascular plant genera with continental-scale distribution data to jointly evaluate phylogenetic diversity (PD), endemism, and diversification rates (DR). We reveal a pronounced decoupling between DR and accumulated evolutionary history across Africa. Mountain, arid, and semi-arid areas emerge as centers of neo-endemism and elevated diversification, whereas lowland and humid regions, particularly the Guineo-Congolian zone, are dominated by older lineages with low recent diversification. Several DR hotspots do not overlap with Global Biodiversity Hotspots, indicating a mismatch between rapid diversification and accumulated evolutionary history. High net diversification and speciation rates during the last 15 million years were likely driven by cooling, aridification, and mountain uplift that created new ecological gradients and isolation barriers. These abiotic changes, interacting with lineage-specific traits, shaped African modern flora and highlight conservation gaps, especially in arid regions

evolutionary biology↗

Plant-adapted OTO staining improves ultrastructural imaging by transmission electron microscopy

Transmission electron microscopy (TEM) is widely used to examine plant cellular ultrastructure, but sample preparation remains challenging because polysaccharide-rich cell walls, large vacuoles and complex membrane systems compromise staining and structural preservation. Here, we developed a plant-adapted TEM preparation method based on a modified osmium-thiocarbohydrazide-osmium (OTO) staining workflow combined with optimized washing, dehydration and resin infiltration. Using tomato roots and leaves, we show that the optimized method produces cleaner backgrounds, better-defined cellular boundaries and improved preservation of cellular morphology compared with conventional preparation. Fine membrane-associated structures, including mitochondrial cristae, chloroplast grana and stroma lamellae, nuclear membranes and other endomembrane structures, were more clearly resolved, while staining-related precipitates and diffuse background artifacts were reduced. This method provides a practical approach for high-contrast TEM imaging of plant tissues and ultrastructural analysis of plant cells and organelles.

plant biology↗

Mitotic chromosomes are mechanically connected by chromatin-based interchromosome linkers

The spatial organization of chromosomes is crucial for gene regulation and genome stability. Metaphase chromosomes appear physically discrete from one another in conventional chromosome preparations. However, interchromosomal connections, or "linkers", have been observed among mitotic chromosomes, and may play important roles in coordinated chromosome movements and genome stability. We use micropipette-based isolation and manipulation to analyze interchromosome linkers between mammalian mitotic chromosomes. Pulling an isolated chromosome reveals that thin linkers connect them; CREST staining indicates their locations to be at centromeres. The linkers display linear elasticity and have a length-doubling force of approximately 300 pN, comparable to the length-doubling force of an entire metaphase chromosome. Enzymatic treatments demonstrate that the linkers are disrupted by DNase, but not by RNase, protease, or microtubule polymerization (spindle fiber) inhibitors, indicating that linker connectivity is based on DNA. Immunofluorescence experiments indicate that histones and topo II are on the linkers, with topo II organized into discrete foci spaced by approximately 0.4 Mbp. After prolonged metaphase arrest using spindle inhibitors isolated genomes do not display interchromosome linkers. Finally, experiments on intact cells show that interchromosome linkers containing CENP-B can be observed between mitotic chromosomes, indicating they are not an artifact of genome isolation.

genomics↗

SAMP V2: A novel stacking ensemble learning model for antimicrobial peptides identification based on augmented split amino acid composition with biochemical-sequence-order information

Antimicrobial resistance reduces the effectiveness of conventional antibiotics and has become a major global health threat, highlighting the need for new anti-infective agents. Antimicrobial peptides (AMPs), a diverse class of innate immune effectors with broad-spectrum antimicrobial activity, are promising candidates for combating drug-resistant infections. Identifying AMPs by wet-lab experiments, however, remains costly and time-consuming, creating a strong demand for computational identification methods. Our recently developed method, SAMP, captures region-specific residue distributions based on proportionalized split amino acid composition. However, SAMP might ignore key biochemical information and sequence order information. Here we present SAMP V2, a stacking ensemble learning framework based on biochemical and sequence-order information augmented split amino acid composition (BIA-SAAC), which extends SAMP by integrating pseudo-amino acid composition features with biochemical and sequence-order information into split peptide regions. Specifically, each peptide is divided into N-terminal, middle, and C-terminal regions, and pseudo amino acid composition is calculated within each region. Benchmarking tests on six independent test datasets, SAMP V2 outperformed multiple state-of-the-art models, including AMPpred-MFA and iAMP-Attenpred, in terms of accuracy, MCC, G-measure and F1-score. Given its high and robust performance, SAMP V2 could significantly accelerate the discovery of next-generation antimicrobial therapeutics for addressing the global threat of multidrug-resistant pathogens.

bioinformatics↗

Proteome Profiling of Human Tear Fluid Following Acute Exercise

Acute exercise induces systemic molecular perturbations that are not fully reflected by individual biomarkers. Tear fluid is amenable to non-invasive and repeated collection and contains a diverse array of bioactive molecules, thereby constituting a practical biological specimen for evaluating exercise-related physiological responses. However, the immediate proteome-wide alterations in tear fluid following acute exercise have not been characterized. In this study, we performed quantitative proteomic profiling of paired tear samples obtained from healthy female participants before and immediately after a single exercise session, using data-independent acquisition liquid chromatography-tandem mass spectrometry (DIA-LC- MS/MS). Among the 3,173 identified proteins, 744were significantly altered post-exercise, of which 484 exhibited up-regulation and 260 exhibited down-regulation. Functional enrichment analysis demonstrated that the up-regulated proteins were predominantly associated with translation and ribosome biogenesis, whereas down-regulated proteins were primarily involved in glycan metabolism, lysosomal processing, and extracellular matrix organization. Collectively, these observations indicate that acute exercise elicits a rapid and coordinated reconfiguration of the tear proteome. To our knowledge, this investigation provides the first proteomic evidence of the immediate tear response to physical activity, offering a molecular basis for understanding exercise-mediated modulation of tear composition and ocular surface homeostasis.

physiology↗

Haplotypes variations of yellow stripe like (TaYSL) genes are associated with grain iron and zinc contents in wheat (Triticum aestivum L.)

The availability of pangenome and resequencing of wheat collections have facilitated the discovery of gene-trait associations in wheat. Yellow stripe-like (YSL) proteins play a key role in the uptake and translocation of metals and yet have not been fully identified and analyzed at the genome-wide level in wheat. In this study, 26 TaYSL genes were identified and divided into four distinct clades, each clade sharing similar domains and motif compositions. Most genes were upregulated under iron deficiency, whereas homoeologs of TaYSL1 were downregulated. Both SNP-based and haplotype-based association studies were used to dissect the role of TaYSLs underpinning grain iron contents (GFeC) and zinc contents (GZnC) in wheat. TaYSL6-2B and TaYSL16-1A haplotypes showed strong association with GFeC, and TaYSL14-6A showed strong association with GZnC in multiple field trials. The distribution of favorable haplotypes in global wheat collection of [~]3000 accessions showed that majority of haplotypes were more prevalent in landraces and winter wheat compared to modern cultivars and spring types, indicating their potential for use in breeding. The combination of favorable haplotypes of three YSL genes associated with GFeC and GZnC were very rare, and most of the wheat accessions has single or double favorable haplotypes. These findings provide the first comprehensive characterization of the TaYSL gene family in wheat and identify significant SNPs and elite haplotypes that can be utilized for genetic improvement and biofortification.

plant biology↗

A Selective Multivalent NET-Associated Chromatin Neutralizer Resolves Infection-Associated Inflammation in Severe Sepsis

Targeting the overwhelming inflammation driven by neutrophil extracellular traps (NETs) during infection provides an opportunity to manage severe sepsis. This potential needs to be realized by exploring selective NET-neutralization materials, which remains a challenge. Herein, we report a multivalent macromolecular strategy that targets NET-associated DNA-histone chromatin complexes while preserving antibacterial activity of aminoglycoside. We identify 8-arm PEG-conjugated netilmicin (8-arm Netil) as a lead NETs-neutralizer from a library of multivalent aminoglycoside-displayed materials. When compared with 2- and 4-arm counterparts, 8-arm Netil exhibits potent antibacterial activity and high-affinity binding to DNA-histone chromatin complexes through stable multivalent noncovalent interactions, thereby suppressing NET-induced TLR4/TLR9 activation and macrophage inflammatory responses. In severe septic mice, intravenously administered 8-arm Netil preferentially accumulates in inflamed tissues, leading to improved survival protection, owing to the reduction of bacterial dissemination, NET accumulation, systemic cytokine production, and multiple-organ injury. These findings establish NET-associated DNA-histone chromatin complexes as actionable extracellular targets and demonstrate multivalent chromatin targeting as a rational material design strategy for selective NET neutralization and inflammation control in severe sepsis.

bioengineering↗

Architectural Confinement and Seasonal Forcing Shape Cross-Domain Pathogen Assemblages in Complex Built Environments

Airborne microbial pathogens in built environments (BEs) may pose potential health threats, yet the ecological mechanisms governing their assembly and persistence across interconnected architectural spaces are less studied. Here, we conducted a year-long, multi-spatial investigation across a university campus complex, sampling the exhaust outlets of three indoor environments and the adjacent outdoor inlets. By integrating the 16S rRNA gene and ITS sequencing from 437 paired bacterial-fungal samples, we characterized the spatiotemporal dynamics of airborne opportunistic pathogen-containing genera. Our study showed that spatial filtering emerged as the dominant determinant of pathogen community structure, with confined elevator environments serving as reservoirs of pathogens with limited but continuous microbial influx from surrounding spaces. Superimposed on this spatial baseline, bacterial and fungal pathogens displayed distinct seasonal dynamics. Opportunistic fungal pathogens such as Fusarium peaked during autumn and winter, possibly driven by enhanced aerosol persistence and dispersal under cooler, drier conditions. In contrast, bacterial pathogens exhibited greater temporal resilience, with key taxa such as Listeria transcribed actively during winter, predisposing them to increased relative abundance during spring. Cross-domain ecological networks further revealed the dynamic interactions among pathogens, centered on the skeletal structure mediated by the keystone fungal pathogen Aspergillus, suggesting that coordinated microbial interactions reinforced pathogen persistence across seasons. Together, our findings support a unified ecological framework in which pathogen dynamics within BEs arise from the coupled effects of spatial filtering, climatic modulation, and biotic interactions. These results provide a foundation for transitioning from static environmental control toward predictive pathogen management in BEs. ImportanceBEs are the primary settings of human microbial exposure, yet the ecological principles governing the persistence of airborne pathogens across interconnected indoor spaces remain poorly resolved. Most previous indoor studies have focused on isolated environments or single microbial groups, limiting our understanding of how pathogens are maintained and redistributed within complex architectural systems. By integrating bacterial and fungal community dynamics across spatial environments over four seasons, this year-long study demonstrates that the ecology of airborne pathogens is not static, but is instead dictated by a complex interplay of spatial, climatic, and biological forces. Our findings identify enclosed, high-transit elevator spaces as critical hotspots for pathogen accumulation and highlight the role of seasonal ecological reorganization in driving airborne health risks. More broadly, this work establishes a systems-level ecological framework for understanding airborne pathogen dynamics in BEs and provides a conceptual basis for developing more adaptive strategies for indoor microbial risk management.

microbiology↗

An oncolytic adenovirus armed with anticancer prodrug-activating enzyme offers enhanced tumor killing and antitumor immunity.

Oncolytic viruses are most commonly administered via intratumoral injection; however, their clinical efficacy in achieving tumor eradication remains limited by several challenges, including insufficient penetration into all tumor cells and the inability to elicit robust systemic antitumor immune responses capable of eliminating metastatic microtumors. Here, we report an oncolytic adenovirus, OAd-2B6, with an engineered adenoviral E1 region for tumor selectivity and carrying the prodrug- activating enzyme cytochrome P450 2B6 (CYP2B6) to activate the anticancer prodrug cyclophosphamide (Cytoxan, CTX). OAd-2B6 alone induced dose-dependent tumor cell killing across multiple human tumor cell lines and exhibited strong synergistic antitumor effects when combined with CTX. Importantly, OAd-2B6-mediated local activation of CTX resulted in a potent bystander killing effect that eliminated tumor cells not directly infected by the virus. In a H1299 lung cancer xenograft nude mouse model, intratumoral injection of OAd-2B6 combined with CTX significantly inhibited tumor growth and even achieved complete tumor regression, with markedly superior efficacy compared with monotherapy. In immunocompetent mice bearing 4T1 breast cancer xenografts, OAd-2B6 alone inhibited tumor growth and was accompanied by upregulation of IFN-{gamma} and GzmB expression in the tumor-infiltrated T cells. CTX combination therapy further enhances this anti-tumor immune response, promoting the activation of T cells to suppress non-injected tumors at a distal site. Collectively, this study demonstrates that OAd-2B6 exerts potent antitumor effects through multiple mechanisms, including direct oncolysis, intratumoral prodrug activation leading to bystander killing, and enhancement of systemic antitumor immunity. These findings provide a promising strategy for improving the therapeutic efficacy of oncolytic therapy.

cancer biology↗

Age-Associated Remodeling of neuroglial Connexin43 in the Mouse and Human Brain

Age-dependent changes in the major neuroglial junctional channel Connexin43 (Cx43) are poorly defined. We integrated public multi-organ and single-cell datasets with high-resolution morphological, biochemical, and functional analyses of human and mouse brains. We reveal a non-linear aging trajectory for Cx43, marked by an adaptational midlife elevation followed by a late-life decline. These molecular changes proceed in the absence of significant cell loss but are associated with extensive glial remodeling. Notably, while astrocytic gap junction coupling in the hippocampus remains largely preserved, aging induces a selective increase in hemichannel mediated dye uptake in both microglia and hippocampal astrocytes. In human cortical and hippocampal tissues, we confirm that aging drives a significant reduction in astrocytic Cx43 expression, alongside characteristic morphological simplification of cell structure and domain contraction. Together, our findings redefine the aging brain as a state of active, multi-level glial remodeling rather than a simple decline in connexin-mediated communication.

neuroscience↗

Reduced MOV10 reveals novel functional cortical connections in an increased fear response

The RNA helicase MOV10 is highly expressed in developing brain, is present in synapses and is required for embryonic viability. A murine brain-specific knockout of MOV10 (Mov10 Deletion) has a thickened cortex, abnormal dendritic arborization and enhanced fear memory. In human studies, MOV10 is among the loci that is correlated with enhanced cortical brain volumes and is also significantly associated with substance dependence by epigenetic profiling. Here we demonstrate that Mov10 Deletion mice show enhanced fear learning that is aligned with impaired structural connectivity of canonical fear circuits revealed by Diffusion Tensor Imaging. We propose a model where MOV10 loss leads to increased GABRA2 expression in the hippocampus and reduced anatomical connectivity that drives augmented fear learning. Memory reactivation is observable during fear memory retrieval as an overall increase in fMRI functional activity in cortical regions. Taken together, this framework identifies that enhanced fear in the MOV10 model is driven via a "corticalized" fear response during re-exposure to the training context that is not driven by the canonical fear circuit. These findings support a molecular basis for non-traditional enhanced learning mechanisms activated by fearful events that shed light on the intractability of fear memories with the potential to inform PTSD and substance dependence disorders.

neuroscience↗

Culsma: A Formal Language for Laboratory Protocols

Laboratory protocols are commonly communicated in natural language, leaving room for variation in how experimental commitments are understood and carried out. We present Culsma, an executable specification language in which protocols are written as programs. The same program is legible to bench scientists and directly machine-readable by software that checks and runs it. It serves as the protocol's operational specification, making experimental commitments explicit for checking before execution and retaining them in results. Culsma addresses how experimental procedures are modeled: it defines operations by the experimental changes and relationships they establish, giving a fine-grained, compositional basis whose technique- and device-specific realizations remain extensible. We examine this boundary in workflows spanning molecular and cell biology, protein biochemistry, and immunoassays, which combine material handling, separation, and measurement differently, asking which distinctions the operation interface preserves. A maintained, source-linked benchmark broadens this evaluation with versioned checks of source-step correspondence and software execution.

bioinformatics↗

AI predictions and the expansion of scientific frontiers: Evidence from structural biology

Artificial intelligence holds the potential to expand the frontier of scientific research, yet recent work has raised concern that it may instead narrow scientific attention to well-established areas. Here, leveraging the 2021 release of AlphaFold2 as a quasi-experimental opportunity, we provide field-level evidence that AI can redirect collective attention toward more novel research targets. Tracking 245,396 experimental structures in the Protein Data Bank, we show that a long-running decline in the study of novel proteins halted after AlphaFold2s release, with the shift concentrated among studies citing AlphaFold2 and targets with high-confidence predictions. This pattern extends to 248,191 downstream papers that consume structural knowledge, where engagement with genes lacking experimental structures and with understudied human genes increased since 2021. Amid rising concern that AI may reinforce scientific canons, our findings offer an early field-level case where AI predictions expand scientific frontiers, consistent with the idea that the real-world consequences of AI on science depend on where their informational gains are greatest. These results suggest AI can complement human knowledge and redirect collective attention in science, with broad implications for emerging AI for science models.

bioinformatics↗

Coronavirus envelope protein drives iron sensing disorder by hijacking the TAp73-FDXR axis

Iron overload is increasingly recognized as a critical contributor to coronavirus pathogenesis1, yet the underlying induction mechanisms remain unclear. Here, we uncover a fundamental pathway by which coronavirus drives IRP1 RNA-binding activity to induce iron accumulation2 via targeting the TAp73-FDXR axis. Specifically, coronavirus infection represses transcription of FDXR (encoding the key rate-limiting enzyme in host iron-sulfur cluster synthesis3), thereby impairing host iron-sulfur cluster generation to trigger the functional conversion of the cytosolic aconitase 1 (ACO1) into iron-regulatory protein 1 (IRP1)4, ultimately leading to the hosts persistently false perception of iron deficiency. We identify TAp73 as the primary transcription factor governing FDXR expression, and demonstrate that the coronavirus envelope protein (CoV-E) orchestrates TAp73 nuclear export. Subsequently, CoV-E binds TAp73 through a critical valine residue within its C-terminal PBM domain, inducing the K48-linked ubiquitination and proteasomal degradation of TAp73. Furthermore, we developed a CoV-E-targeting molecule, DPTP-FC, which blocks CoV-E-TAp73 interaction via forming steric hindrance and effectively alleviates iron accumulation and tissue damage caused by PEDV, PDCoV, and SARS-CoV-2 infection. Our study reveals the central role of the TAp73-FDXR axis in CoV-induced iron accumulation, highlighting CoV-E as an attractive antiviral target and DPTP-FC as a promising therapeutic candidate.

microbiology↗

Paternal behavior is controlled by preoptic Trpc5 neurons

Male parenting behavior is highly conserved and activated only after offspring are born. Here we show that the behavioral switch from infanticide in virgin male mice to caregiving in wild-type sires is associated with enhanced expression and activation of Transient receptor potential channel 5 (Trpc5) in estrogen receptor (Esr1)-expressing neurons in the hypothalamic medial preoptic area (MPOA). While selective deletion of Trpc5 from Esr1MPOA neurons diminishes paternal behavior in sires, overexpression of Trpc5 in these neurons converts the otherwise infanticidal virgin males to exhibit care to pups. Mechanistically, Trpc5-dependent changes in neuronal excitability underlie fatherhood-associated Esr1MPOA neuron plasticity. Notably, Trpc5 overexpression also enhances escape behavior and elicits exploratory diving behavior, suggesting that these neurons control a broader adaptive parenting response in males. These findings establish a Trpc5-dependent MPOA neural signal as a critical regulator of paternal behavior.

neuroscience↗

Red yeast rice-derived MKA ameliorates cardiac hypertrophy in hypertensive rats by inhibiting ERK1/2/c-Fos pathway

BackgroundCardiac hypertrophy is a key pathological process in hypertensive heart failure, yet current antihypertensive therapies do not directly target it. Red yeast rice (RYR), rich in monacolin K {beta}-hydroxy acid (MKA), is known for lipid-lowering effects, but its potential to ameliorate cardiac hypertrophy is unreported. PurposeTo investigate the effects of RYR-derived MKA on cardiac hypertrophy in spontaneously hypertensive rats (SHR) and elucidate its molecular mechanisms. MethodsSpontaneously hypertensive rats (SHR) were treated with 0.6% red yeast rice for 8 weeks to assess its effects on blood pressure, cardiac function (echocardiography), cardiac hypertrophy and fibrosis (histopathology), and multi-organ toxicity (histopathology). A multigenerational study was conducted to evaluate protective effects in offspring. Network pharmacology and transcriptomic analysis were integrated to predict molecular targets, which were subsequently validated by molecular docking and experiments. ResultsEight-week RYR treatment significantly reduced blood pressure, inhibited cardiac hypertrophy and fibrosis, and improved cardiac function without gender differences. No pulmonary, hepatic, or renal toxicity was observed. Offspring from treated parents exhibited further reduced hypertrophy upon continued treatment. Mechanistically, MKA bound ERK1/2 with high affinity, inhibiting its phosphorylation and downstream c-Fos expression, thereby downregulating hypertrophy markers. ConclusionRed yeast rice improves hypertensive cardiac hypertrophy via MKA-mediated inhibition of the ERK1/2/c-Fos pathway. Its multi-organ safety and transgenerational effects offer a novel dual-therapy strategy for hypertension and cardiac hypertrophy. Graphic abstract O_FIG O_LINKSMALLFIG WIDTH=139 HEIGHT=200 SRC="FIGDIR/small/710945v1_ufig1.gif" ALT="Figure 1"> View larger version (57K): org.highwire.dtl.DTLVardef@8225acorg.highwire.dtl.DTLVardef@775f43org.highwire.dtl.DTLVardef@10f5201org.highwire.dtl.DTLVardef@d0cd88_HPS_FORMAT_FIGEXP M_FIG C_FIG

pharmacology and toxicology↗

Fibronectin 1 is required for suture patency and dysregulated across craniosynostosis models in the mouse

The mammalian skull roof is comprised of calvarial bones, connected through fibrous sutures, that protect the brain and allow for growth. Premature suture closure, or craniosynostosis (CS), impedes expansion, impacting 1 in every 2500 newborns. Despite its genetic heterogeneity, with nearly 80 associated genes, CS manifests as a common phenotype, hinting at a convergent etiological mechanism. Recently, we described how graded expression of extracellular matrix protein Fibronectin (FN1) is required for apical expansion of calvaria and coronal suture patency. Dysregulated FN1 expression has been identified in two human CS syndromes, suggesting its potential as a convergent mechanism of CS. Here, we further investigate the cellular basis for the CS phenotype in the Fn1 mutant mouse. Graded expression of FN1 baso-apically in the cranial mesenchyme was variably dysregulated across mouse models of syndromic and non-syndromic CS and accompanied by diminished apical expansion of frontal bone primordia. In parallel, at later developmental stages we find ectopic osteogenic induction of Six2+ patent suture mesenchyme in the Fn1 mutant. These findings pinpoint FN1 as a crucial regulator of suture patency by modulating calvarial growth and driving cell identity, and differentiation, thus providing a potential target for matrix-mediated treatments.

developmental biology↗

Clinical Metabolomics studies in diagnosing Prediabetes and Type 2 Diabetes: Unveiling Trends through Bibliometric Analysis

BackgroundPrediabetes is the transitional stage preceding the onset of type 2 diabetes. Due to its asymptomatic nature and slow progression, conventional screening methods frequently fail to identify individuals in this prediabetic stage. Therefore, this study employs bibliometric methods to reveal the abnormal changes in clinically relevant metabolites in diabetes, providing evidence for early diagnosis, pathogenesis, and precision interventions. MethodsSearch the Web of Science Core Collection database for all papers on metabolomics related to prediabetes and type 2 diabetes clinical research from the databases inception until May 2025. Use VOSviewer and CiteSpace software to perform bibliometric analysis on the included literature. ResultsA total of 1,742 studies were ultimately included in the review of the literature. Researchers from China, the United States, and Germany, as well as institutions, have made significant contributions to metabolomics research in prediabetes and type 2 diabetes. The highest number of publications and citations was from the journals Metabolites and Diabetes. The current research hotspots in this field, as determined by keyword co-occurrence and clustering analysis, include metabolomics, insulin resistance, obesity, risk factors, biomarkers, gut microbiota, amino acids, lipidomics, and mass spectrometry. ConclusionThe outcomes of the study are instrumental in enabling scholars to comprehend the developmental trajectory of metabolites associated with prediabetes and type 2 diabetes and facilitate the rapid identification of emerging research pathways.

immunology↗