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Zhang, S.

Publications and source records attributed to Zhang, S..

At least 289 records · Page 16Linked to original sources

STARNet enables spatially resolved inference of gene regulatory networks from spatial multi-omics data

Biological tissues are composed of distinct microenvironments that spatially orchestrate gene expression and cell identity. However, the regulatory principles governing domain-specific cellular functions remain poorly understood due to the lack of effective methods for mapping gene regulatory networks (GRNs) in situ. To address this gap, we introduce STARNet, a representation learning approach that leverages heterogeneous hypergraph modeling of spatial transcriptomic and epigenomic data to resolve tissue-domain-specific regulatory interactions. By integrating graph neural networks with contrastive learning in a self-supervised framework, STARNet learns unified embeddings that preserve both multi-modal molecular features and anatomical spatial context, enabling accurate and domain-resolved GRN reconstruction within complex tissues. Benchmarking on both simulated and real datasets demonstrates that STARNet achieves state-of-the-art performance. We further demonstrate its broad applicability across diverse biological contexts, including neural development, genetic disease risk, and drug-induced developmental toxicity. In the mouse brain, it delineates region-specific regulatory networks and reconstructs spatiotemporal programs underlying neural stem cell differentiation. In human genetics, it provides a mechanistic link between genotypes and phenotypes by showing how genome-wide association study (GWAS) variants for complex diseases perturb hippocampus-specific GRNs. In developmental toxicology, STARNet reveals that drug-induced disruptions of GRNs in defined embryonic regions underlie tissue-specific vulnerability. Collectively, STARNet offers a powerful and versatile framework for resolving the spatial regulatory logic of complex tissues, providing multi-angle insights into tissue patterning, development, and disease mechanisms.

bioinformatics↗

Lipid-facilitated opening of the ADAM10 sheddase revealed by enhanced sampling simulations

ADAM10 is a crucial membrane-bound metalloprotease that regulates cellular physiology by cleaving and releasing membrane-anchored proteins, including adhesion molecules and growth factor precursors, thereby modulating cell signaling, adhesion, and migration. Despite its central role, its activation mechanisms are not fully understood. Here, we model how phosphatidylserine (PS) exposure during apoptosis triggers ADAM10 activation. We confirmed that PS externalization leads to shedding of CD43 from the surface of T cells via ADAM10 activity. Intriguingly, ADAM10 activation correlated with a loss of monoclonal ADAM10 antibody binding, suggesting a PS-induced conformational change that alters epitope accessibility. To explore this lipid-mediated conformational change of ADAM10, we employed molecular dynamics (MD) simulations to map the conformational landscape of ADAM10. Our simulations revealed that in the absence of PS, ADAM10 samples predominantly closed and intermediate states. By contrast, the presence of PS destabilizes the closed conformation, thereby favoring open states. We provide a mechanistic explanation for this PS-induced conformational change which drives ADAM10 activation and loss of mAb binding through conformational change. These findings offer new insights into the lipid-mediated regulation of ADAM10 and its conformational dynamics.

biophysics↗

Lipid Droplets of Human Carotid Atherosclerotic Plaques: Cholesteryl Arachidonate Core and Cytoskeletal Fibrotic Cover

Lipid droplets (LDs) within atherosclerotic plaques are central to cardiovascular disease, yet their molecular composition remains largely unknown. More than 20 years experiences of developing LD purification method allowed us recently to successfully purify LDs from atherosclerotic plaques of patients undergoing carotid artery surgery, including three types, soft (lipid), mixed, and hard (calcified). In addition, the subpopulations of large LDs and small LDs were purified and studied, respectively. We report the first comprehensive proteo-lipidomic analysis of these LDs. Unexpectedly, about 19.3% of the plaque LD proteins belonged to cytoskeleton, while the content of lipid metabolism enzymes on plaque LDs was low. Our results show that the compositions of lipids and proteins were similar between two population LDs. Compared to soft (lipid) plaque LDs, LDs from mixed and hard (calcified) plaques had fewer metabolic enzymes and more cytoskeletal proteins. Lipidomics of the LD core uncovered an unexpected enrichment of polyunsaturated fatty acid cholesteryl esters (PUFA-CEs), which constituted 88.3% of all cholesterol esters. Notably, esters of the pro-inflammatory precursor arachidonic acid (AA) were among the most abundant species (16.5%). In addition, plaque LD were uniquely enriched in phospholipids including phosphatidic acid (PA), phosphatidylethanolamine plasmagens (PE-P), sphingomyelin (SM), and phosphatidylserine (PS). Our findings redefine the plaque LD as a dual-function "bad" organelle: a metabolically inert container for cholesterol ester, coated with cytoskeletons, and a massive reservoir for inflammatory precursors.

cell biology↗

A Phosphorelay Circuit Drives Extracellular Alkalinization in Plant Receptor Kinase Signaling

Extracellular alkalinization has long been recognized as a hallmark of plant cell-surface receptor activation, including during pattern-triggered immunity (PTI); yet the mechanisms driving elicitor-induced alkalinization and its role in immune signaling remain unclear. Here, we demonstrate that inhibition of autoinhibited H+-ATPases (AHAs) is required for elicitor-induced extracellular alkalinization. This alkalinization is essential for immune signaling mediated by diverse plasma membrane-localized receptor kinases (RKs) through modulation of ligand-receptor interactions. Notably, RKs transduce elicitor-triggered signaling via BOTRYTIS-INDUCED KINASE 1 (BIK1), which inhibits AHA activity by disrupting AHA-GENERAL REGULATORY FACTOR (GRF) interactions through a conserved phosphorylation event. Interestingly, this pathway is crucial for cell wall damage (CWD) responses involving the RK MALE DISCOVERER 1-INTERACTING RECEPTOR LIKE KINASE 2 (MIK2) and its ligand, SERINE RICH ENDOGENOUS PEPTIDE 18 (SCOOP18). Our findings reveal a conserved phospho-regulatory pathway that governs extracellular alkalinization to coordinate plant immune signaling, offering new insights into plant stress resilience.

plant biology↗

Temporal Clonal Tracing and Functional Perturbation Reveal Niche-Adaptive and Tumor-Intrinsic IFNγ Dependencies Driving Ovarian Cancer Metastasis

Metastasis is an emergent continuum driven by evolving reciprocal adaptations between disseminating tumor cells (DTCs) and specialized niches of different organs. The interplay between intrinsic and niche-driven mechanisms that enable DTCs to survive and home to distant organs in peritoneal ovarian cancer metastasis remains incompletely understood. Here, we present MetTag, a single-cell barcoding and transcriptome profiling approach with single cell clonality barcodes and time-stamped batch identifiers (BC.IDs) to resolve metastasis clonality and temporal dynamics of DTC colonization. Deep sequencing of MetTag barcodes revealed enrichment of early-disseminated clones across metastatic sites, and targeted depletion of pioneer DTCs diminished the outgrowth of subsequent arriving DTCs. Subsequent MetTag-coupled single cell RNA sequencing (scRNA-seq) on ascites and metastasis-bearing omenta revealed a distinct interferon-gamma (IFN{gamma})-centric transcriptional trajectory selectively enriched among pioneer clones. In vivo CRISPR/Cas9 screening of niche-specific signatures demonstrated that the tumor-intrinsic IFN{gamma} response is functionally required for peritoneal metastasis. Knockout of the IFN{gamma} receptor 1 (Ifngr1) in the initial pioneer DTCs significantly reduced total metastatic burden, revealing a critical window of time in which IFN{gamma} signaling shapes the post-seeding metastatic niche (PSMN) and subsequent metastatic evolution. Mechanistically, the tumor-intrinsic IFN{gamma} response induced Poly(ADP-Ribose) polymerase family member 14 (Parp14) and peritoneal macrophages cooperatively shield DTCs from anoikis by promoting pro-survival signaling. Our study defines the temporal clonal architecture of peritoneal niches and reveals a "first come, first served" adaptation principle, where pioneer colonizer fitness determines the success of subsequent colonizers.

cancer biology↗

Spatial Transcriptomics Reveal Developmental Dynamics of the Human Cerebral Cortex and Striatum

The human fetal brain undergoes morphological changes that contribute to the development of regional functionalities. However, the features of structural development, the underlying molecular and cellular signatures in the fetal brain remain unclear. With spatial transcriptomics and snRNA-seq, we identified 25 forebrain regions and characterized the dynamic changes in the cortex and striatum during the late first and early second trimesters. In particular, we discovered that temporal lobe enriched NPY-expressing L2/3 EX neuron potentially interacted with L4 EX neurons during cortical expansion and arealization. Additionally, the gyrus and sulcus were developmental asynchronous, in which HOPX and SPARC genes were potentially involved. Further investigation on the striatum showed specific genes and cell types that enriched in patch and matrix compartments, and SST-positive interneurons potentially involved in the development of these structures. Together, our results give insights into the understanding of early fetal brain development.

bioinformatics↗

Mechanistic and Epigenetic Partitioning of Lamina-Associated Chromatin Revealed by a Genome-Wide Imaging Screen

The nuclear periphery is a key site for heterochromatin organization in eukaryotic cells, where lamina-associated domains (LADs) promote transcriptional repression and genome stability. Despite their importance, the mechanisms governing LAD positioning in human cells remain poorly understood. To this end, we performed a genome-wide imaging-based siRNA screen and identified over 100 genes critical for perinuclear LAD localization, with a striking enrichment for RNA-binding proteins. Among these, hnRNPK emerged as a key regulator, required for the perinuclear positioning of approximately two-thirds of LADs genome-wide. Loss of hnRNPK led to LAD repositioning away from the nuclear periphery without altering their heterochromatin state, yet resulted in misexpression of genes within these domains. Notably, hnRNPK-sensitive LADs are uniquely marked by both H3K9me2 and H3K27me3, distinguishing them from hnRNPK-insensitive LADs that are enriched for H3K9me2 and H3K9me3. These findings reveal at least two mechanistically and epigenetically distinct LAD classes, suggesting that specialized pathways underlie their spatial organization. Our results uncover a pivotal role for hnRNPK in regulating the spatial organization of chromatin and highlight the broader diversity of LAD localization mechanisms.

cell biology↗

A Simple Algorithm to Suppress Diagonal Peaks in High-Resolution Homonuclear Chemical Shift Correlation NMR Spectra

Previous experimental strategies aimed at completely suppressing diagonal peaks in NMR homonuclear correlation spectra often resulted in reduced sensitivity for cross peaks. In this work, we report a spectral shearing approach that transforms diagonal peaks along the diagonal axis of a homonuclear correlation spectrum into a zero-frequency line in the indirect dimension. This allows for effective extraction and substantial suppression of diagonal peaks using a recently proposed data processing algorithm based on quadrature-detected spin-echo diagonal peak suppression. Since the shearing process only rearranges the positions of cross peaks without affecting their intensities, the sensitivity of cross peaks is fully preserved while diagonal peaks are significantly reduced. The effectiveness of this method is demonstrated using uniformly 13C&15N labeled -synuclein amyloid fibril and aquaporin Z membrane protein samples.

biophysics↗

De novo design of light-regulated dynamic proteins using deep learning

Recent advances in deep learning have enabled accurate design of static protein structures, but the de novo design of protein functions controlled by programmable, intramolecular conformational changes remains an unsolved challenge. Here, we present a general deep learning-guided framework for designing dynamic, multi-domain proteins allosterically regulated by light. By integrating photoresponsive domains into de novo scaffolds, we engineered conformational switches that exhibit precise, reversible structural transitions upon illumination. Structural, spectroscopic, and functional analyses validated our designs and demonstrated precise spatio-temporal optogenetic control of diverse cellular processes, including subcellular localization, intercellular signaling, and population-level behaviors. This work establishes a broadly applicable strategy for encoding long-range allosteric control through designed intramolecular motions, and opens new avenues for programming dynamic protein functions from first principles, with implications for basic research, synthetic biology, and therapeutic development.

biophysics↗

Pan-ASLM: a high-resolution and large-field-of-view light sheet microscope for Expansion Microscopy

Expansion microscopy, a super-resolution fluorescence microscopy technique in which samples are expanded up to [~]8,000 times (after 20-fold expansion) their original volume, places high demands on the microscopes used to image the expanded samples. To reveal nanoscale cellular ultrastructure in meaningful sample volumes, the instruments need to feature a large field of view and working distance. Simultaneously, they need to offer a high three-dimensional resolution to avoid counteracting the resolution improvement achieved by the expansion process. Here, we present pan-ASLM, a high resolution, large field-of-view light-sheet microscope developed for expanded samples, based on the Axially Swept Light Sheet Microscopy (ASLM) technique. pan-ASLM allows imaging over a 640 {micro}m x 640 {micro}m field of view with lateral and axial resolutions of 566 nm and 457 nm, respectively, and features an image acquisition speed of up to 20 fps (183 Mvoxels/sec). It offers [~]1200x higher imaging speed, a [~]7x larger field of view, and [~]2x better axial resolution than the standard confocal microscopes typically used for expanded samples. We validate the new microscope design through imaging of pan-expanded HeLa cells as well as mouse kidney and brain tissue.

biophysics↗

Defined human tri-lineage brain microtissues

Microglia are the immune cells of the central nervous system and are thought to be key players in both physiological and disease conditions. Several microglial features are poorly conserved between mice and human, such as the function of the neurodegeneration-associated immune receptor Trem2. Induced pluripotent stem cell (iPSC)-derived microglia offer a powerful opportunity to generate and study human microglia. However, human iPSC-derived microglia often exhibit activated phenotypes in vitro, and assessing their impact on other brain cell types remains challenging due to limitations in current co-culture systems. Here, we developed fully defined brain microtissues, composed of human iPSC-derived neurons, astrocytes, and microglia, co-cultured in 2D or 3D formats. Our microtissues are stable and self-sufficient over time, requiring no exogenous cytokines or growth factors. All three cell types exhibit morphologies characteristic of their in vivo environment and show functional properties. Co-cultured microglia develop more homeostatic phenotypes compared to microglia exposed to exogenous cytokines. Hence, these tri-cultures provide a unique approach to investigate cell-cell interactions between brain cell types. We found that astrocytes and not neurons are sufficient for microglial survival and maturation, and that astrocyte-derived M-CSF is essential for microglial survival. Single-cell and single-nucleus RNA sequencing analyses nominated a network of reciprocal communication between cell types. Brain microtissues faithfully recapitulated pathogenic -synuclein seeding and aggregation, suggesting their usefulness as human cell models to study not only normal but also pathological cell biological processes.

neuroscience↗

Exogenous Photoreceptor-Specific N-Glycosylated PROM1 Rescues Retinal Degeneration in Patient and Mouse Models

PROM1 is widely expressed across various tissues. However, its pathogenic mutations are exclusively associated with inherited retinal dystrophy (IRD). The mechanisms underlying this retina-specific vulnerability remain poorly understood, and no effective treatment currently exists for PROM1-IRD. Here, we utilized urine cells, hiPSCs, hiPSC-RPE cells, retinal organoids (ROs) and Prom1-/- mice to address these challenges. During photoreceptor development in ROs, PROM1 co-localized with ciliary marker ARL13B and outer segment (OS) marker PRPH2. It exhibited photoreceptor-specific mRNA splicing isoforms and unique N-glycosylation. In IRD patient-specific models with the PROM1 c.619G>T (p.E207X) homozygous mutation, we observed nonsense-mediated mRNA decay and altered splicing, leading to complete loss of PROM1 protein and OS-like structure disruption, faithfully recapitulating PROM1-IRD pathology. To rescue these defects, we engineered a photoreceptor-specific AAV7m8-CRXp-hPROM1, which successfully restored PROM1 expression and OS-like structures in patient-derived ROs. Therapeutic efficacy was further validated in Prom1-/- mice, where subretinal delivery of AAV8-CRXp-hPROM1 led to photoreceptor-specific expression of human PROM1, significantly preserving OS morphology and improving visual function. These findings not only provide the first solid preclinical evidence supporting gene therapy for PROM1-IRD, but also reveal photoreceptor-specific vulnerability to PROM1 mutations, offering a novel conceptual framework for investigating and treating related IRDs.

neuroscience↗

Ethanol induces neuroimmune dysregulation and soluble TREM2 generation in a human iPSC neuron, astrocyte, microglia triculture model

Alcohol use disorders (AUDs) affect substantial populations worldwide and increase the risk of developing cognitive impairments and alcohol-associated dementia. While chronic inflammatory signaling likely plays an important role in alcohol-associated neurological sequalae, the precise mechanisms underlying alcohol-associated neuropathology remain enigmatic. We hypothesize that alcohol leads to neuroimmune dysregulation among neurons, astrocytes, and microglia; and is perpetuated by innate immune signaling pathways involving cell-cell signaling. To investigate how alcohol dysregulates neuroimmune interactions in a human context, we constructed a triculture model comprising neurons, astrocytes, and microglia derived from human induced pluripotent stem cells. After exposure to ethanol, we observed significant differential gene expression relating to innate immune pathways, inflammation, and microglial activation. Microglial activation was confirmed with morphological analysis and expression of CD68, a lysosomal-associated membrane protein and marker for phagocytic microglial activation. A striking finding in our study was the elevation of TREM2 expression and, specifically, TREM2 alternative splice variants that are predicted to give rise to soluble TREM2. TREM2 has been reported to be a risk factor for Alzheimers disease. These results suggest that ethanol exposure in the brain may lead to increased microglial activation and production of soluble isoform named TREM2219 through alternate splicing. Deciphering the molecular and cellular mechanisms underpinning ethanol-related neuroimmune dysregulation within a human context promises to shed light on the etiology of AUD-related disorders, potentially contributing to the development of effective therapeutic strategies. HighlightsO_LIWe prepared a "triculture" of human iPSC-derived neurons, astrocytes and microglia C_LIO_LIEthanol treatment produces substantial changes in gene expression with prominent effects on neuroimmune signaling C_LIO_LISeveral microglia-specific genes are induced by ethanol in tricultures but not in cultures of microglia alone C_LIO_LITREM2 expression is increased following ethanol treatment and results indicate a differential splicing of isoforms, encoding a soluble form of TREM2 C_LI

neuroscience↗

A complete and near-perfect rhesus macaque reference genome: lessons from subtelomeric repeats and sequencing bias

A truly complete, telomere-to-telomere (T2T), and error-free reference genome remains a foundational resource--and long-standing goal--for unbiased comparative and functional genomics. While recent T2T assemblies of humans and other primates have made substantial progress, most still contain thousands of base-level errors, particularly within highly repetitive regions. Here, we present T2T-MMU8v2.0, a near-perfect T2T assembly of the rhesus macaque (Macaca mulatta), representing the highest base-level accuracy reported in a primate genome to date. By employing an optimized ONT-only assembly strategy, we identify subtelomeric satellite-rich regions as the principal bottleneck to improving assembly quality, owing to technological biases in long-read platforms and limitations in current hybrid assembly frameworks. We discover 268 previously unannotated repeat families and resolve [~]8 Mbp of SATR satellite arrays, with over 99-fold enrichment in historically misassembled subtelomeric regions. These satellites form four distinct genomic architectures, each with unique SATR satellite composition, segmental duplication organization, and epigenetic signatures, distinct from the subtelomeric architectures observed in hominid genomes. Notably, in contrast to the largely gene-poor subtelomeric regions in African hominids, the SATR architectures in macaques harbor 58 actively transcribed genes, supported by open chromatin and expression data, suggesting gene innovation within these repetitive regions. Functionally, T2T-MMU8v2.0 improves read mappability and accuracy across sequencing platforms, and results in a 19% improvement of transcription start site enrichment scores and 5,821 additional chromatin accessibility peaks on average, thereby enhancing variant detection, regulatory annotation, and transcriptomic resolution in population genetics or single-nucleus studies. Together, this work establishes a new benchmark for genomics, offers a roadmap for resolving complex repetitive regions, and reveals previously unrecognized features of subtelomeric genome structure and evolution.

genomics↗

Defining and cataloging variants in pangenome graphs

Structural variation causes some human haplotypes to align poorly with the linear reference genome, leading to reference bias. A pangenome reference graph could ameliorate this bias by relating a sample to multiple reference assemblies. However, this approach requires a new definition of a genetic variant. We introduce a definition of pangenome variants and a method, pantree, to identify them. Our approach involves a pangenome reference tree which includes all nodes (sequences) of the pangenome graph, but only a subset of its edges; non-reference edges are variant edges. Our variants are biallelic and have well-defined positions. Analyzing the Minigraph-Cactus draft human pangenome reference graph, we identified 29.6 million genetic variants. Most variants (99.2%) are small, and most small variants (73.9%) are SNPs. 3.5 million variants (11.7%) have a reference allele which is not on GRCh38; these variants are difficult to detect without a pangenome reference, or with existing pangenome-based approaches. They tend to be embedded within tangled, multiallelic regions. We analyze two medically relevant regions, around the HLA-A and RHD genes, identifying thousands of small variants embedded within several large insertions, deletions, and inversions. We release an open-source software tool together with a VCF variant catalogue.

genomics↗

CD133+ Vesicles Mediate Resistance to RAS-ERK Inhibition Regulated by YAP Activation in Liver Cancer Cells

CD133, a pentaspan plasma membrane protein, has been viewed as a biomarker of stem cells in normal and cancer tissues, although its function and mechanism are unclear. In previous studies, we identified a new type of CD133+ intracellular vesicles, named intercellsome, which is implicated in direct cell-cell communication under stress conditions. However, the regulatory mechanism and biological significance of these CD133+ vesicles are largely unknown, highlighting a gap in understanding of this cellular communication mechanism. We show here that CD133 acts as a stress response marker in cancer cells, with its expression and vesicle formation significantly induced under MEK inhibitor-mediated proliferative stress. The CD133+ vesicles are essential for maintaining cell proliferation under stress conditions in vitro. Mechanistically, the MEKi activates the Hippo-YAP signaling pathway, which promotes CD133 transcription, establishing a novel connection between YAP signaling and CD133+ vesicle biogenesis. Further, CD133 plays a critical role in YAP-driven liver cancer progression in mice. This study defines a critical role of CD133+ vesicles in stress response regulated by YAP, which advances the understanding of CD133 functions beyond its stem cell-associated roles and suggests new avenues for therapeutic intervention of liver cancer relapse.

cancer biology↗

SUMO proteases SPF1/2 inhibit seed filling and fatty acid biosynthesis by deSUMOylating WRI1

Seed filling and fatty acid biosynthesis are critical processes for seed development and oil accumulation in plants, regulated by intricate post-translational mechanisms. Here, we elucidate the molecular mechanism by which SUMO proteases SPF1 and SPF2 regulate seed filling and fatty acid biosynthesis by modulating the stability of the WRI1 protein through deSUMOylation in Arabidopsis. SPF1 and SPF2 were found to negatively regulate seed filling and oil accumulation by promoting WRI1 degradation via deSUMOylation, which enhances its interaction with BPM proteins and subsequent ubiquitination. Our findings establish a dynamic interplay between deSUMOylation and ubiquitination in controlling WRI1 stability, unveiling a novel mechanism for seed filling. These findings establish SPF1/2 as crucial factor in maintaining WRI1 stability and seed filling, providing valuable genetic resources and a theoretical foundation for improving seed quality and oil content in agricultural production.

plant biology↗

HPInet: Interpretable prediction of Host-Pathogen protein-protein Interactions using a transformer-based neural network

Gram-negative bacteria utilize a series of secretion systems (T1SS-T10SS) to deliver secreted effector proteins (T1SE-T10SE) into host cells, leading to infections and diseases. Understanding the interactions between these effector proteins and host proteins is crucial for unraveling the pathogenic mechanisms of bacterial pathogens. Despite advancements in sequencing technologies that have significantly enhanced our knowledge of effector protein diversity and structure, the molecular mechanisms underlying their interactions with human host proteins remain unclear. Experimental approaches to validate these interactions are labor-intensive, time-consuming, and insufficient to comprehensively map the extensive effector-host protein interaction (PPI) network. Additionally, specialized computational tools for predicting these interactions remain scarce. To address this gap, we developed HPInet, a transformer-based deep learning model for predicting interactions between bacterial effector proteins and human host proteins. HPInet introduces convolutional layers and global response normalization (GRN) into the feed-forward network (FFN) of the transformer architecture, enhancing the extraction of local sequence features. Compared to existing state-of-the-art methods, HPInet significantly improves prediction performance, increasing accuracy from 0.502 to 0.891 and boosting sensitivity by 35.3%. Furthermore, by leveraging the models attention mechanism, HPInet identifies critical residues at interaction sites, demonstrating its capability to capture local structural features of PPI sites solely from sequence information. To facilitate its application in research, HPInet has been implemented as a freely accessible web server available at https://bis.zju.edu.cn/hpinet. This platform provides a powerful and interpretable tool for studying effector-host protein interactions, offering valuable insights into bacterial pathogenesis and potential therapeutic targets.

bioinformatics↗