The multifaceted role of macrophage mitophagy in SiO2-induced pulmonary fibrosis: A brief review.

Prolonged exposure to environments with high concentrations of crystalline silica (CS) can lead to silicosis. Macrophages play a crucial role in the pathogenesis of silicosis. In the process of silicosis, silica (SiO2) invades alveolar macrophages (AMs) and induces mitophagy which usually exists in three states: normal, excessive, and/or deficiency. Different mitophagy states lead to corresponding toxic responses, including successful macrophage repair, injury, necrosis, apoptosis, and even pulmonary fibrosis. This is a complex process accompanied by various cytokines. Unfortunately, the details have not been fully systematically summarized. Therefore, it is necessary to elucidate the role of macrophage mitophagy in SiO2-induced pulmonary fibrosis by systematic analysis on the literature reports. In this review, we first summarized the current data on the macrophage mitophagy in the development of SiO2-induced pulmonary fibrosis. Then, we introduce the molecular mechanism on how SiO2-induced mitophagy causes pulmonary fibrosis. Finally, we focus on introducing new therapies based on newly developed mitophagy-inducing strategies. We conclude that macrophage mitophagy plays a multifaceted role in the progression of SiO2-induced pulmonary fibrosis, and reprogramming the macrophage mitophagy state accordingly may be a potential means of preventing and treating pulmonary fibrosis.

Sulfonate Functional Ultramicroporous Materials with Suitable Pore Size and Layer-Stacked Structure for C4 Olefins Purification.

Selective recognition of 1,3-butadiene from complex olefin isomers is vital for 1,3-butadiene purification, but the lack of porous materials with suitable pore structures results in poor selectivity and low capacity in C4 olefin separation. Herein, two sulfonate-functionalized organic frameworks, ZU-601 and ZU-602, are designed and show impressive separation performance toward C4 olefins. Benefiting from the suitable aperture size caused by the flexibility of coordinated organic ligand, ZU-601, ZU-602 that are pillared with different sulfonate anions could discriminate C4 olefin isomers with high uptake ratio: 1,3-butadiene/1-butene (207), 1,3-butadiene/trans-2-butene (10.1). Meanwhile, their layer-stacked structure enables the utilization of both intra- and interlayer space, enhancing the accommodation of guest molecules. ZU-601 exhibits record high 1,3-butadiene adsorption capacity of 2.90 mmol g-1 (0.5 bar, 298 K) among the reported flexible porous materials with high 1,3-butadiene/1-butene selectivity. The breakthrough experiments confirm their superior separation ability even for all five C4 olefin isomers, and the molecular-level structural change is well elucidated via powder, crystal analysis, and simulation studies. The work provides ideas toward advanced materials design with simultaneous high separation capacity and high separation selectivity for challenging separations.

CYP7B1-mediated 25-hydroxycholesterol degradation maintains quiescence-activation balance and improves therapeutic potential of mesenchymal stem cells.

Stem cells remain quiescent in vivo and become activated in response to external stimuli. However, the mechanism regulating the quiescence-activation balance of bone-marrow-derived mesenchymal stem cells (BM-MSCs) is still unclear. Herein, we demonstrated that CYP7B1 was the common critical molecule that promoted activation and impeded quiescence of BM-MSCs under inflammatory stimulation. Mechanistically, CYP7B1 degrades 25-hydroxycholesterol (25-HC) into 7α,25-dihydroxycholesterol (7α,25-OHC), which alleviates the quiescence maintenance effect of 25-HC through Notch3 signaling pathway activation. CYP7B1 expression in BM-MSCs was regulated by NF-κB p65 under inflammatory conditions. BM-MSCs from CYP7B1 conditional knockout (CKO) mice had impaired activation abilities, relating to the delayed healing of bone defects. Intravenous infusion of BM-MSCs overexpressing CYP7B1 could improve the pathological scores of mice with collagen-induced arthritis. These results clarified the quiescence-activation regulatory mechanism of BM-MSCs through the NF-κB p65-CYP7B1-Notch3 axis and provided insight into enhancing BM-MSCs biological function as well as the subsequent therapeutic effect.

A molecular sieve with ultrafast adsorption kinetics for propylene separation.

The design of molecular sieves is vital for gas separation, but it suffers from a long-standing issue of slow adsorption kinetics due to the intrinsic contradiction between molecular sieving and diffusion within restricted nanopores. We report a molecular sieve ZU-609 with local sieving channels that feature molecular sieving gates and rapid diffusion channels. The precise cross-sectional cutoff of molecular sieving gates enables the exclusion of propane from propylene. The coexisting large channels constituted by sulfonic anions and helically arranged metal-organic architectures allow the fast adsorption kinetics of propylene, and the measured propylene diffusion coefficient in ZU-609 is one to two orders of magnitude higher than previous molecular sieves. Propylene with 99.9% purity is obtained through breakthrough experiments with a productivity of 32.2 L kg-1.

TNF-α-Induced KAT2A Impedes BMMSC Quiescence by Mediating Succinylation of the Mitophagy-Related Protein VCP.

Regular quiescence and activation are important for the function of bone marrow mesenchymal stem cells (BMMSC), multipotent stem cells that are widely used in the clinic due to their capabilities in tissue repair and inflammatory disease treatment. TNF-α is previously reported to regulate BMMSC functions, including multilineage differentiation and immunoregulation. The present study demonstrates that TNF-α impedes quiescence and promotes the activation of BMMSC in vitro and in vivo. Mechanistically, the TNF-α-induced expression of KAT2A promotes the succinylation of VCP at K658, which inhibits the interaction between VCP and MFN1 and thus inhibits mitophagy. Furthermore, activated BMMSC exhibits stronger fracture repair and immunoregulation functions in vivo. This study contributes to a better understanding of the mechanisms of BMMSC quiescence and activation and to improving the effectiveness of BMMSC in clinical applications.

Association of gut microbiome and oral cavity cancer: A two sample mendelian randomization and case-control study.

INTRODUCTION: Considering the interconnectedness of the oral cavity and gut tract and the presence of abundant natural microbiota in both. We utilized Mendelian Randomization (MR) in a two-sample study to unveil the genetic causal impact of gut microbiota on the development of oral cavity cancer. MATERIALS & METHODS: The instrumental variables employed in this study consisted of single nucleotide polymorphisms (SNPs) that demonstrated a robust association with 211 distinct gut microbiota taxa, encompassing a sample size of 18,340 individuals. Our investigation sought to explore the potential causal relationship between these genetic variants and the incidence of oral cavity cancer. To accomplish this, we adopted a random effect inverse variance-weighted approach to analyze the causal effect. Additionally, sensitivity analyses were performed utilizing Cochran's Q tests, funnel plots, leave-one-out analyses, and MR-Egger intercept tests, to assess the robustness and validity of our findings. RESULTS: Five gut microbiota taxa (the family Prevotellaceae, the genus Alloprevotella, the genus Erysipelatoclostridium, the genus Parabacteroides, the genus Ruminococcus gauvreauii group) are predicted to play a causal role in promoting the initiation of the risk of oral cavity cancer. While the genus Christensenellaceae R 7 group, the genus Intestinimonas, the genus Ruminococcaceae, and the order Bacillales causally reduce the risk of oral cavity cancer. Furthermore, no significant evidence suggesting heterogeneity or pleiotropy was observed. DISCUSSION: The novel genetic causal effects of 211 gut microbiota taxa on oral cavity cancer are elucidated in this investigation, thus offering valuable insights for clinical interventions targeting oral cavity cancer.

Fibular free flap necrosis after mandibular reconstruction surgery with osteoradionecrosis: Establishment and verification of an early warning model.

OBJECTIVE: Fibular free flap necrosis (FFFN) is the most common complication in patients with osteoradionecrosis (ORN) after mandibular reconstruction surgery. However, there are no effective forecasting tools at present. This research is aimed to establish and verify a nomogram model to predict the risk of FFFN after mandibular reconstruction surgery in ORN patients. METHODS: A total of 193 ORN patients with mandibular reconstruction using fibular free flap (150 cases in the model group and 43 cases in the validation group) were enrolled in this study. In the model group, the variables were optimized by lasso regression. Then the prediction model was established by binary logistic regression analysis, and the nomogram was drawn. The bootstrap self-sampling method was used for internal verification. Moreover, 43 cases in the validation group were used for external validation. RESULTS: The results of lasso regression and binary logistic regression analysis showed that the radiotherapy interval (≤2 years), trismus, diabetes, without deep venous anastomoses, and American society of anesthesiologists (ASA) III were the independent risk factors for FFFN after mandibular reconstruction surgery in ORNJ patients (P<0.05). Based on the above-mentioned risk factors, the nomogram model was established. The AUC values of the model group and the validation group were 0.936 and 0.964, respectively. The curve analysis showed that when the probability thresholds of the model group and the validation group were 5.699%∼98.229% and 0.413%∼99.721%, respectively. So the patient's clinical net profit rate was the highest. CONCLUSION: A nomogram combining the factors of radiotherapy interval (≤2 years), trismus, diabetes, without deep venous anastomoses, and ASA III provided a comparatively effective way to predict the risk of FFFN after mandibular reconstruction surgery in ORN patients, which has distinct applied clinical value.

Silicon dioxide-induced endoplasmic reticulum stress of alveolar macrophages and its role on the formation of silicosis fibrosis: a review article.

Silicosis is a chronic lung inflammatory disease induced by long-term inhalation of high concentrations of silicon dioxide (SiO2), characterized by pulmonary fibrosis. Inhalation of silica invades alveolar macrophages (AMs) and changes the micro-environment of the cell, resulting in abnormal morphology and dysfunction of the endoplasmic reticulum (ER). Once beyond the range of cell regulation, the endoplasmic reticulum stress (ERS) will occur, which will lead to cell damage, necrosis, and apoptosis, eventually causing silicosis fibrosis through various mechanisms. This is a complex and delicate process accompanied by various macrophage-derived cytokines. Unfortunately, the details have not been systematically summarized yet. In this review, we systematically introduce the basic two processes: the process of inducing ERS by inhaling SiO2 and the process of inducing pulmonary fibrosis by ERS. Moreover, the underlying mechanism of the above two sequential events is also be discussed. We conclude that the ERS of alveolar macrophages caused by silica dust are involved deeply in the pathogenesis of silicosis. Therefore, changing the states of SiO2-induced ERS of macrophage may be an attractive therapeutic target for silicosis fibrosis.

Iron deficiency-induced ferritinophagy impairs skeletal muscle regeneration through RNF20-mediated H2Bub1 modification.

Iron deficiency (ID) is a widespread condition concomitant with disease and results in systemic dysfunction of target tissues including skeletal muscle. Activated by ID, ferritinophagy is a recently found type of selective autophagy, which plays an important role in various physiological and pathological conditions. In this study, we demonstrated that ID-mediated ferritinophagy impeded myogenic differentiation. Mechanistically, ferritinophagy induced RNF20 degradation through the autophagy-lysosomal pathway and then negatively regulated histone H2B monoubiquitination at lysine-120 in the promoters of the myogenic markers MyoD and MyoG, which inhibited myogenic differentiation and regeneration. Conditional knockout of NCOA4 in satellite cells, overexpression of RNF20 or treatment with 3-methyladenine restored skeletal muscle regenerative potential under ID conditions. In patients with ID, RNF20 and H2Bub1 protein expression is downregulated in skeletal muscle. In conclusion, our study indicated that the ferritinophagy-RNF20-H2Bub1 axis is a pathological molecular mechanism underlying ID-induced skeletal muscle impairment, suggesting potential therapeutic prospects.

Mitochondrial Damage-Associated Molecular Patterns and Metabolism in the Regulation of Innate Immunity.

The innate immune system, as the host's first line of defense against intruders, plays a critical role in recognizing, identifying, and reacting to a wide range of microbial intruders. There is increasing evidence that mitochondrial stress is a major initiator of innate immune responses. When mitochondria's integrity is disrupted or dysfunction occurs, the mitochondria's contents are released into the cytosol. These contents, like reactive oxygen species, mitochondrial DNA, and double-stranded RNA, among others, act as damage-related molecular patterns (DAMPs) that can bind to multiple innate immune sensors, particularly pattern recognition receptors, thereby leading to inflammation. To avoid the production of DAMPs, in addition to safeguarding organelles integrity and functionality, mitochondria may activate mitophagy or apoptosis. Moreover, mitochondrial components and specific metabolic regulations modify properties of innate immune cells. These include macrophages, dendritic cells, innate lymphoid cells, and so on, in steady state or in stimulation that are involved in processes ranging from the tricarboxylic acid cycle to oxidative phosphorylation and fatty acid metabolism. Here we provide a brief summary of mitochondrial DAMPs' initiated and potentiated inflammatory response in the innate immune system. We also provide insights into how the state of activation, differentiation, and functional polarization of innate immune cells can be influenced by alteration to the metabolic pathways in mitochondria.

A modified triangular flap suture method used for inferior third molar extraction: A three-arm randomized clinical trial for the assessment of quality of life

Background: The purpose of this study is to explore whether decreasing the number of sutures can improve the quality of life after inferior third molar extraction. Material and methods: This study used a three-arm randomized design that included 90 individuals. Patients were randomized and divided into three groups-the airtight suture group (traditional), the buccal drainage group, and the no-suture group. Postoperative measurements, including treatment time, visual analog scale, questionnaire on postoperative patient quality of life, and details about trismus, swelling, dry socket, and other postoperative complications were obtained twice and the mean values were recorded. To verify the normal distribution of the data, the Shapiro-Wilk test was performed. The statistical differences were evaluated using the one-way ANOVA and the Kruskal-Wallis test with Bonferroni post-hoc correction. Results: The buccal drainage group showed a significant decrease in postoperative pain and better speech ability than the no-suture group on the 3st day, with a mean of 1.3 and 0.7 (P < 0.05). The airtight suture group also showed similar eating and speech ability, which was better than the no-suture group, with a mean of 0.6 and 0.7 (P < 0.05). However, no significant improvements were noted on the 1st and 7th days. The surgical treatment time, postoperative social isolation, sleep impairment, physical appearance, trismus, and swelling showed no statistical difference between the three groups at all measured times (P > 0.05). Conclusions: Based on the above findings, the triangular flap without a buccal suture may be superior to the traditional group and no-suture group in less pain, and better postoperative patient satisfaction in the first 3 days and may be a simple and viable option in clinical practice. (AU)

Intercrystalline Channels at Subnanometer Scale for Precise Molecular Nanofiltration.

Membrane-based technologies can provide cost-effective and energy-efficient methods for various separation processes. The key goal is to develop materials with uniform, tunable, and well-defined subnanometer-scale channels. Suitable membrane materials should have high selectivity and permeance and can be manufactured in a robust and scalable fashion. Here, we report the construction of sub-1 nm intercrystalline channels with such characteristics and elucidate their transport properties. These channels are formed by assembling 3D aluminum formate crystals during the amorphous-to-crystalline transformation process. By controlling the transformation time, the channel size can be tuned from the macroscopic scale to nanometer scale. The resulting membranes exhibit tailored selectivity and permeance, with molecular weight cutoffs ranging from around 300 Da to approximately 650 Da, and ethanol permeance ranging from 0.8 to 22.0 L m-2 h-1 bar-1. We further show that liquid flow through these channels changes from viscosity-dominated continuum flow to subcontinuum flow, which can be described by a modified Hagen-Poiseuille model. Our strategy provides a new scalable platform for applications that commonly exploit nanoscale mass transport.

Super enhancers targeting ZBTB16 in osteogenesis protect against osteoporosis.

As the major cell precursors in osteogenesis, mesenchymal stem cells (MSCs) are indispensable for bone homeostasis and development. However, the primary mechanisms regulating osteogenic differentiation are controversial. Composed of multiple constituent enhancers, super enhancers (SEs) are powerful cis-regulatory elements that identify genes that ensure sequential differentiation. The present study demonstrated that SEs were indispensable for MSC osteogenesis and involved in osteoporosis development. Through integrated analysis, we identified the most common SE-targeted and osteoporosis-related osteogenic gene, ZBTB16. ZBTB16, positively regulated by SEs, promoted MSC osteogenesis but was expressed at lower levels in osteoporosis. Mechanistically, SEs recruited bromodomain containing 4 (BRD4) at the site of ZBTB16, which then bound to RNA polymerase II-associated protein 2 (RPAP2) that transported RNA polymerase II (POL II) into the nucleus. The subsequent synergistic regulation of POL II carboxyterminal domain (CTD) phosphorylation by BRD4 and RPAP2 initiated ZBTB16 transcriptional elongation, which facilitated MSC osteogenesis via the key osteogenic transcription factor SP7. Bone-targeting ZBTB16 overexpression had a therapeutic effect on the decreased bone density and remodeling capacity of Brd4fl/fl Prx1-cre mice and osteoporosis (OP) models. Therefore, our study shows that SEs orchestrate the osteogenesis of MSCs by targeting ZBTB16 expression, which provides an attractive focus and therapeutic target for osteoporosis. Without SEs located on osteogenic genes, BRD4 is not able to bind to osteogenic identity genes due to its closed structure before osteogenesis. During osteogenesis, histones on osteogenic identity genes are acetylated, and OB-gain SEs appear, enabling the binding of BRD4 to the osteogenic identity gene ZBTB16. RPAP2 transports RNA Pol II from the cytoplasm to the nucleus and guides Pol II to target ZBTB16 via recognition of the navigator BRD4 on SEs. After the binding of the RPAP2-Pol II complex to BRD4 on SEs, RPAP2 dephosphorylates Ser5 at the Pol II CTD to terminate the transcriptional pause, and BRD4 phosphorylates Ser2 at the Pol II CTD to initiate transcriptional elongation, which synergistically drives efficient transcription of ZBTB16, ensuring proper osteogenesis. Dysregulation of SE-mediated ZBTB16 expression leads to osteoporosis, and bone-targeting ZBTB16 overexpression is efficient in accelerating bone repair and treating osteoporosis.

Temperature-dependent rearrangement of gas molecules in ultramicroporous materials for tunable adsorption of CO2 and C2H2.

The interactions between adsorbed gas molecules within porous metal-organic frameworks are crucial to gas selectivity but remain poorly explored. Here, we report the modulation of packing geometries of CO2 and C2H2 clusters within the ultramicroporous CUK-1 material as a function of temperature. In-situ synchrotron X-ray diffraction reveals a unique temperature-dependent reversal of CO2 and C2H2 adsorption affinities on CUK-1, which is validated by gas sorption and dynamic breakthrough experiments, affording high-purity C2H2 (99.95%) from the equimolar mixture of C2H2/CO2 via a one-step purification process. At low temperatures (<253 K), CUK-1 preferentially adsorbs CO2 with both high selectivity (>10) and capacity (170 cm3 g-1) owing to the formation of CO2 tetramers that simultaneously maximize the guest-guest and host-guest interactions. At room temperature, conventionally selective adsorption of C2H2 is observed. The selectivity reversal, structural robustness, and facile regeneration of CUK-1 suggest its potential for producing high-purity C2H2 by temperature-swing sorption.

Customed 3D-printed Polyetheretherketone (PEEK) Implant for Secondary Salvage Reconstruction of Mandibular Defects: Case Report and Literature Review.

Given the insufficient height of single-barrel fibula and inadequate bone volume of double-barrel vascularized fibula in mandibular reconstruction, it is a better choice to combine the upper full-thickness vascularized fibula with the lower half-thickness nonvascularized fibula. However, the nonvascularized fibula may fail due to complications, affecting the facial shape and occlusal function. Polyetheretherketone is a thermoplastic polymer used for bone defect reconstruction due to its good mechanical properties and biocompatibility. This case report mainly presents a secondary salvage reconstruction of the mandible by using customed 3-dimensional-printing polyetheretherketone, which restored the continuity and symmetry of the mandible, improved the patient's facial shape, and restored functional occlusion through dental implants. After a 28-month follow-up, no complications occurred, and the patient was satisfied with the final restoration.

Exclusive Recognition of CO2 from Hydrocarbons by Aluminum Formate with Hydrogen-Confined Pore Cavities.

Exclusive capture of carbon dioxide (CO2) from hydrocarbons via adsorptive separation is an important technology in the petrochemical industry, especially for acetylene (C2H2) production. However, the physicochemical similarities between CO2 and C2H2 hamper the development of CO2-preferential sorbents, and CO2 is mainly discerned via C recognition with low efficiency. Here, we report that the ultramicroporous material Al(HCOO)3, ALF, can exclusively capture CO2 from hydrocarbon mixtures, including those containing C2H2 and CH4. ALF shows a remarkable CO2 capacity of 86.2 cm3 g-1 and record-high CO2/C2H2 and CO2/CH4 uptake ratios. The inverse CO2/C2H2 separation and exclusive CO2 capture performance from hydrocarbons are validated via adsorption isotherms and dynamic breakthrough experiments. Notably, the hydrogen-confined pore cavities with appropriate dimensional size provide an ideal pore chemistry to specifically match CO2 via a hydrogen bonding mechanism, with all hydrocarbons rejected. This molecular recognition mechanism is unveiled by in situ Fourier-transform infrared spectroscopy, X-ray diffraction studies, and molecular simulations.

One-Abutment at One-Time in Posterior Edentulism: A Systematic Review and Meta-Analysis.

OBJECTIVE: The objective of this systematic review and meta-analysis was to investigate the clinical significance of one-abutment at one-time protocol in healed posterior edentulism. METHODS: An online search was undertaken in November 2022, which included PubMed, Cochrane Library, Wiley Online Library, and Google Scholar in addition to manual searching. The Cochrane Collaboration tool was performed to assess the quality of selected articles. Marginal bone loss (MBL) was estimated by the performance of meta-analysis. Moreover, all the pooled analyses were based on random-effect models. Subgroup analysis was applied to evaluate the effects of different variables. RESULTS: In line with the inclusion criteria, 6 trials with 446 dental implants were identified. The meta-analysis showed a total of 0.22 mm less MBL within 6 months and decreased by 0.30 mm at 1-year follow-up in favor of one-abutment at one-time protocol. A significant loss MBL was found in implants placed equicrestally using one-abutment at one-time protocol [6 months: mean difference (MD): -0.22 mm; 95% CI, -0.34 to 0.10 mm, P =0.0004; 12 months: MD: -0.32 mm; 95% CI, -0.40 to -0.24 mm, P <0.00001), whereas no difference was found between 2 groups in an implant placed subscrestally (6 months: MD: 0.14 mm; 95% CI, -0.03 to 0.22 mm; P =0.11; 12 months: MD: -0.12 mm; 95% CI, -0.32 to 0.08 mm; P =0.23). CONCLUSIONS: Implant platform position might greatly affect the marginal bone level. Moreover, one-abutment at one-time protocol demonstrated better bone preservation in implants placed equicrestally in healed posterior edentulism. CLINICAL RELEVANCE: This study highlights the significant clinical application of one-abutment at one-time protocol in healed posterior edentulism.

Sleep Deprivation Promotes Endothelial Inflammation and Atherogenesis by Reducing Exosomal miR-182-5p.

BACKGROUND: Insufficient or disrupted sleep increases the risk of cardiovascular disease, including atherosclerosis. However, we know little about the molecular mechanisms by which sleep modulates atherogenesis. This study aimed to explore the potential role of circulating exosomes in endothelial inflammation and atherogenesis under sleep deprivation status and the molecular mechanisms involved. METHODS: Circulating exosomes were isolated from the plasma of volunteers with or without sleep deprivation and mice subjected to 12-week sleep deprivation or control littermates. miRNA array was performed to determine changes in miRNA expression in circulating exosomes. RESULTS: Although the total circulating exosome levels did not change significantly, the isolated plasma exosomes from sleep-deprived mice or human were a potent inducer of endothelial inflammation and atherogenesis. Through profiling and functional analysis of the global microRNA in the exosomes, we found miR-182-5p is a key exosomal cargo that mediates the proinflammatory effects of exosomes by upregulation of MYD88 (myeloid differentiation factor 88) and activation of NF-ĸB (nuclear factor kappa-B)/NLRP3 pathway in endothelial cells. Moreover, sleep deprivation or the reduction of melatonin directly decreased the synthesis of miR-182-5p and led to the accumulation of reactive oxygen species in small intestinal epithelium. CONCLUSIONS: The findings illustrate an important role for circulating exosomes in distant communications, suggesting a new mechanism underlying the link between sleep disorder and cardiovascular disease.

Covalent organic framework atropisomers with multiple gas-triggered structural flexibilities.

Covalent organic frameworks (COFs) are emerging crystalline porous polymers, showing great potential for applications but lacking gas-triggered flexibility. Atropisomerism was experimentally discovered in 1922 but has rarely been found in crystals with infinite framework structures. Here we report atropisomerism in COF single crystals. The obtained COF atropisomers, namely COF-320 and COF-320-A, have identical chemical and interpenetrated structures but differ in the spatial arrangement of repeating units. In contrast to the rigid COF-320 structure, its atropisomer (COF-320-A) exhibits unconventional gas sorption behaviours with one or more sorption steps in isotherms at different temperatures. Single-crystal structures determined from continuous rotation electron diffraction and in situ powder X-ray diffraction demonstrate that these adsorption steps originate from internal pore expansion with or without changing the crystal space group. COF-320-A recognizes different gases by expanding its internal pores continuously (crystal-to-amorphous transition) or discontinuously (crystal-to-crystal transition) or having mixed transition styles, distinguishing COF-320-A from existing soft/flexible porous crystals. These findings extend atropisomerism from molecules to crystals and propel COFs into the covalently linked soft porous crystal regime, further advancing applications of soft porous crystals in gas sorption, separation and storage.