Subject(s)
Epigenesis, Genetic , Gene Editing , Humans , Gene Editing/methods , CRISPR-Cas Systems , Epigenomics/methods , AnimalsABSTRACT
While cycloaddition reactions of bicyclobutanes (BCBs) have emerged as a potent method for synthesizing (hetero-)bicyclo[n.1.1]alkanes (usually n ≤ 3), their utilization in the synthesis of bicyclo[4.1.1]octane derivatives (BCOs) is still underdeveloped. Here, a palladium-catalyzed formal (4 + 3) reaction of BCBs with 1,4-O/C dipole precursors for the synthesis of oxa-BCOs is described. Unlike previous catalytic polar (3 + X) cycloadditions of BCBs, which are typically achieved through the activation of BCB substrates, the current reaction represents a novel strategy for realizing the cycloaddition of BCBs through the activation of the "X" cycloaddition partner. Moreover, the obtained functionalized oxa-BCOs products can be readily modified through various synthetic transformations.
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Dysregulation of epigenetics is a hallmark of cancer development, and YTHDF1 stands out as a crucial epigenetic regulator with the highest DNA copy number variation among all N6-methyladenosine (m6A) regulators in colorectal cancer (CRC) patients. Here, we aimed to investigate the specific contribution of YTHDF1 overexpression to CRC progression and its consequences. Through multiple bioinformatic analysis of human cancer databases and clinical CRC samples, we identified GID8/Twa1 as a crucial downstream target of YTHDF1. YTHDF1 manipulates GID8 translation efficiency in a m6A-dependent manner, and high expression of GID8 is associated with more aggressive tumor progression and poor overall survival. Mechanistically, GID8 is intimately associated with glutamine metabolic demands by maintaining active glutamine uptake and metabolism through the regulation of excitatory amino acid transporter 1 (SLC1A3) and glutaminase (GLS), thereby facilitating the malignant progression of CRC. Inhibition of GID8 attenuated CRC proliferation and metastasis both in vitro and in vivo. In summary, we identified a previously unknown target pertaining to glutamine uptake and metabolism in tumor cells, underscoring the potential of GID8 in the treatment of CRC.
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Background: In some patients, persistent gastrointestinal symptoms like abdominal pain, nausea, and diarrhea occur as part of long COVID-19 syndrome following acute respiratory symptoms caused by SARS-CoV-2. However, the characteristics of immune cells in the gastrointestinal tract of COVID-19 patients and their association with these symptoms remain unclear. Methodology: Data were collected from 95 COVID-19 patients. Among this cohort, 11 patients who exhibited gastrointestinal symptoms and underwent gastroscopy were selected. Using imaging mass cytometry, the gastrointestinal tissues of these patients were thoroughly analyzed to identify immune cell subgroups and investigate their spatial distribution. Results: Significant acute inflammatory responses were found in the gastrointestinal tissues, particularly in the duodenum, of COVID-19 patients. These alterations included an increase in the levels of CD68+ macrophages and CD3+CD4+ T-cells, which was more pronounced in tissues with nucleocapsid protein (NP). The amount of CD68+ macrophages positively correlates with the number of CD3+CD4+ T-cells (R = 0.783, p < 0.001), additionally, spatial neighborhood analysis uncovered decreased interactions between CD68+ macrophages and multiple immune cells were noted in NP-positive tissues. Furthermore, weighted gene coexpression network analysis was employed to extract gene signatures related to clinical features and immune responses from the RNA-seq data derived from gastrointestinal tissues from COVID-19 patients, and we validated that the MEgreen module shown positive correlation with clinical parameter (i.e., Total bilirubin, ALT, AST) and macrophages (R = 0.84, p = 0.001), but negatively correlated with CD4+ T cells (R = -0.62, p = 0.004). By contrast, the MEblue module was inversely associated with macrophages and positively related with CD4+ T cells. Gene function enrichment analyses revealed that the MEgreen module is closely associated with biological processes such as immune response activation, signal transduction, and chemotaxis regulation, indicating its role in the gastrointestinal inflammatory response. Conclusion: The findings of this study highlight the role of specific immune cell groups in the gastrointestinal inflammatory response in COVID-19 patients. Gene coexpression network analysis further emphasized the importance of the gene modules in gastrointestinal immune responses, providing potential molecular targets for the treatment of COVID-19-related gastrointestinal symptoms.
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A series of scutellarein 7-l-amino acid carbamate-4'-cycloalkylamine propyl ether conjugates were designed and synthesized for the first time as multifunctional agents for Alzheimer's disease (AD) therapy. The designed compounds exhibited more balanced and effective multi-target potency. Among them, compound 11l, l-Valine carbamate derivative of scutellarein cycloheptylamine ether, exhibited the most potent inhibition of electric eel AChE enzymes and human AChE enzymes, with an IC50 values of 7.04 µM and 9.73 µM, respectively. Moreover, 11l exhibited more potent H3R antagonistic activities than clobenpropit, with an IC50 value of 1.09 nM. Compound 11l not only displayed excellent inhibition of self- and Cu2+-induced Aß1-42 aggregation (95.48 % and 88.63 % inhibition, respectively) but also induced the disassembly of self- and Cu2+-induced Aß fibrils (80.16 % and 89.30 % disaggregation, respectively). Moreover, 11l significantly reduced tau protein hyperphosphorylation induced by Aß25-35. It exhibited effective antioxidant activity and neuroprotective potency, and inhibited RSL3-induced PC12 cell ferroptosis. Assays of hCMEC/D3 and hPepT1-MDCK cell line permeability indicated that 11l would have optimal blood-brain barrier permeability and intestinal absorption characteristics. In addition, in vivo studies revealed that compound 11l significantly attenuated learning and memory impairment in an AD mouse model. Finally, a pharmacokinetic characterization of 11l indicated favorable druggability and pharmacokinetic properties. Taken together, our results suggest that 11l is a potential candidate for AD treatment and merits further investigation.
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Osteosarcoma (OS) is a primary bone cancer mostly found in adolescents and elderly individuals. The treatment of OS is still largely dependent on traditional chemotherapy. However, the high incidence of drug resistance remains one of the greatest impediments to limiting improvements in OS treatment. Recent findings have indicated that the transcription factor FOXM1 plays an important role in various cancer-related events, especially drug resistance. However, the possible role of FOXM1 in the resistance of OS to methotrexate (MTX) remains to be explored. Here, we find that FOXM1, which confers resistance to MTX, is highly expressed in OS tissues and MTX-resistant cells. FOXM1 overexpression promotes MTX resistance by enhancing autophagy in an HMMR/ATG7-dependent manner. Importantly, silencing of FOXM1 or inhibiting autophagy reverses drug resistance. These findings demonstrate a new mechanism for FOXM1-induced MTX resistance and provide a promising target for improving OS chemotherapy outcomes.
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Patients with hematological tumors experience physical and psychological stress, and negative psychological states. Baduanjin, an emerging psychological rehabilitation method combined with resistance exercise, has received widespread attention. This study reviews the current status of the application of Baduanjin combined with resistance exercise in improving the negative psychological state of patients with hematological tumors and discusses its problems and prospects. Through a literature review and comprehensive analysis, the application of Baduanjin and resistance exercise in the psychological rehabilitation of patients with hematological tumors was identified and evaluated. The results showed that Baduanjin with resistance exercise had a positive effect on improving negative psychological states of patients with hematological tumors, which can alleviate anxiety, depression, and other adverse emotions, and improve quality of life. However, there is a lack of unified and standardized exercise intervention programs for practical application, and patient participation and compliance must be improved. Baduanjin combined with resistance exercise can potentially improve the negative psychological status of patients with hematological tumors; however, it is still necessary to further standardize and improve the exercise program improving patient participation and compliance. Future studies should strengthen theoretical exploration and empirical research, providing more effective psychological rehabilitation strategies for patients with hematological tumors.
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Asymmetric soft-stiff patch nanohybrids with small size, spatially separated organics and inorganics, controllable configuration, and appealing functionality are important in applications, while the synthesis remains a great challenge. Herein, based on polymeric single micelles (the smallest assembly subunit of mesoporous materials), we report a dynamic surface-mediated anisotropic assembly approach to fabricate a new type of small asymmetric organic/inorganic patch nanohybrid for the first time. The size of this asymmetric organic/inorganic nanohybrid is â¼20 nm, which contains dual distinct subunits of a soft organic PS-PVP-PEO single micelle nanosphere (12 nm in size and 632 MPa in Young' modulus) and stiff inorganic SiO2 nanobulge (â¼8 nm, 2275 MPa). Moreover, the number of SiO2 nanobulges anchored on each micelle can be quantitatively controlled (from 1 to 6) by dynamically tuning the density (fluffy or dense state) of the surface cap organic groups. This small asymmetric patch nanohybrid also exhibits a dramatically enhanced uptake level of which the total amount of intracellular endocytosis is about three times higher than that of the conventional nanohybrids.
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Conventional strategies for highly selective and active hydrogen peroxide (H2O2) electrosynthesis primarily focus on catalyst design. Electrocatalytic reactions take place at the electrified electrode-electrolyte interface. Well-designed electrolytes, when combined with commercial catalysts, can be directly applied to high-efficiency H2O2 electrosynthesis. However, the role of electrolyte components is equally crucial but is significantly under-researched. In this study, anionic surfactant n-tetradecylphosphonic acid (TDPA) and its analogs are used as electrolyte additives to enhance the selectivity of the two-electron oxygen reduction reaction. Mechanistic studies reveal that TDPA assembled over the electrode-electrolyte interface modulates the electrical double-layer structure, which repels interfacial water and weakens the hydrogen-bond network for proton transfer. Additionally, the hydrophilic phosphonate moiety affects the coordination of water molecules in the solvation shell, thereby directly influencing the proton-coupled kinetics at the interface. The TDPA-containing catalytic system achieves a Faradaic efficiency of H2O2 production close to 100% at a current density of 200 mA cm-2 using commercial carbon black catalysts. This research provides a simple strategy to enhance H2O2 electrosynthesis by adjusting the interfacial microenvironment through electrolyte design.
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BACKGROUND: Emerging evidence indicates the pivotal involvement of circular RNAs (circRNAs) in cancer initiation and progression. Understanding the functions and underlying mechanisms of circRNAs in tumor development holds promise for uncovering novel diagnostic indicators and therapeutic targets. In this study, our focus was to elucidate the function and regulatory mechanism of hsa-circ-0003764 in hepatocellular carcinoma (HCC). METHODS: A newly discovered hsa-circ-0003764 (circPTPN12) was identified from the circbase database. QRT-PCR analysis was utilized to assess the expression levels of hsa-circ-0003764 in both HCC tissues and cells. We conducted in vitro and in vivo experiments to examine the impact of circPTPN12 on the proliferation and apoptosis of HCC cells. Additionally, RNA-sequencing, RNA immunoprecipitation, biotin-coupled probe pull-down assays, and FISH were employed to confirm and establish the relationship between hsa-circ-0003764, PDLIM2, OTUD6B, P65, and ESRP1. RESULTS: In HCC, the downregulation of circPTPN12 was associated with an unfavorable prognosis. CircPTPN12 exhibited suppressive effects on the proliferation of HCC cells both in vitro and in vivo. Mechanistically, RNA sequencing assays unveiled the NF-κB signaling pathway as a targeted pathway of circPTPN12. Functionally, circPTPN12 was found to interact with the PDZ domain of PDLIM2, facilitating the ubiquitination of P65. Furthermore, circPTPN12 bolstered the assembly of the PDLIM2/OTUD6B complex by promoting the deubiquitination of PDLIM2. ESRP1 was identified to bind to pre-PTPN12, thereby fostering the generation of circPTPN12. CONCLUSIONS: Collectively, our findings indicate the involvement of circPTPN12 in modulating PDLIM2 function, influencing HCC progression. The identified ESRP1/circPTPN12/PDLIM2/NF-κB axis shows promise as a novel therapeutic target in the context of HCC.
Subject(s)
Carcinoma, Hepatocellular , Cell Proliferation , Gene Expression Regulation, Neoplastic , LIM Domain Proteins , Liver Neoplasms , NF-kappa B , RNA, Circular , RNA-Binding Proteins , Signal Transduction , Carcinoma, Hepatocellular/genetics , Carcinoma, Hepatocellular/pathology , Carcinoma, Hepatocellular/metabolism , Humans , Liver Neoplasms/genetics , Liver Neoplasms/pathology , Liver Neoplasms/metabolism , RNA, Circular/genetics , LIM Domain Proteins/genetics , LIM Domain Proteins/metabolism , NF-kappa B/metabolism , Mice , Animals , RNA-Binding Proteins/metabolism , RNA-Binding Proteins/genetics , Cell Line, Tumor , Disease Progression , Apoptosis/genetics , Prognosis , Microfilament Proteins/genetics , Microfilament Proteins/metabolism , Male , Female , Mice, NudeABSTRACT
Background: Chimeric antigen receptor T (CAR-T) cell therapies have achieved remarkable success in the treatment of hematological tumors. However, given the distinct features of solid tumors, particularly heterogeneity, metabolic aggressiveness, and fewer immune cells in tumor microenvironment (TME), the practical utility of CAR-T cells for solid tumors remains as a challenging issue. Meanwhile, although anti-PD-1 monoclonal antibody (mAb) has shown clinical efficacy, most mAbs also show limited clinical benefits for solid tumors due mainly to the issues associated with the lack of immune cells in TME. Thus, the infiltration of targeted immunological active cells into TME could generate synergistic efficacy for mAbs. Methods: We present a combinational strategy for solid tumor treatment, which combines armored-T cells to express Fc-gamma receptor I (FcγRI) fragment on the surfaces for targeting various tumors with therapeutically useful mAbs. Choosing CD20 and HER-2 as the targets, we characterized the in vitro and in vivo efficacy and latent mechanism of the combination drug by using flow cytometry, ELISA and other methods. Results: The combination and preprocessing of armored T-cells with corresponding antibody of Rituximab and Pertuzumab exerted profound anti-tumor effects, which is demonstrated to be mediated by synergistically produced antibody-dependent cellular cytotoxicity (ADCC) effects. Meanwhile, mAb was able to carry armored-T cell by preprocessing for the infiltration to TME in cell derived xenograft (CDX) model. Conclusions: This combination strategy showed a significant increase of safety profiles from the reduction of antibody doses. More importantly, the present strategy could be a versatile tool for a broad spectrum of cancer treatment, with a simple pairing of engineered T cells and a conventional antibody.
Subject(s)
Neoplasms , Receptors, IgG , T-Lymphocytes , Tumor Microenvironment , Receptors, IgG/immunology , Receptors, IgG/metabolism , Humans , Animals , Mice , Neoplasms/immunology , Neoplasms/therapy , Neoplasms/drug therapy , T-Lymphocytes/immunology , Tumor Microenvironment/immunology , Antibodies, Monoclonal/therapeutic use , Antibodies, Monoclonal/immunology , Cell Line, Tumor , Xenograft Model Antitumor Assays , Immunotherapy, Adoptive/methods , Receptor, ErbB-2/immunology , Receptor, ErbB-2/antagonists & inhibitors , Antineoplastic Agents, Immunological/pharmacology , Antineoplastic Agents, Immunological/therapeutic use , Receptors, Chimeric Antigen/immunology , Receptors, Chimeric Antigen/genetics , Female , Antigens, CD20/immunologyABSTRACT
Severe acne, characterized by cysts and nodules, can significantly impact a patient's self-image and quality of life [1]. In China, first-line treatments for severe acne typically include oral isotretinoin, topical benzoyl peroxide, and oral or topical antibiotics [2]. However, due to concerns about safety, oral isotretinoin and antibiotics are not recommended for lactating women, posing challenges in treating acne in this population and often leading to emotional distress. While photodynamic therapy has shown effectiveness in patients unwilling to take oral medications [3], treating severe acne during lactation remains a complex issue with limited research available. In this unique case, fire needle combined with photodynamic therapy was successfully utilized to address severe acne in a lactating patient. Following treatment, the patient experienced clearance of cysts, nodules, and pustules, as well as an improvement in depressive symptoms, yielding significant outcomes. Nevertheless, the efficacy and safety of this combined approach warrant further investigation through clinical trials.
Subject(s)
Acne Vulgaris , Lactation , Photochemotherapy , Photosensitizing Agents , Humans , Female , Photochemotherapy/methods , Acne Vulgaris/drug therapy , Photosensitizing Agents/therapeutic use , Adult , Aminolevulinic Acid/therapeutic use , Combined Modality TherapyABSTRACT
Peripheral nerve injury seriously endangers human life and health, but there is no clinical drug for the treatment of peripheral nerve injury, so it is imperative to develop drugs to promote the repair of peripheral nerve injury. Erythropoietin (EPO) not only has the traditional role of promoting erythropoiesis, but also has a tissue-protective effect. Over the past few decades, researchers have confirmed that EPO has neuroprotective effects. However, side effects caused by long-term use of EPO limited its clinical application. Therefore, EPO derivatives with low side effects have been explored. Among them, ARA290 has shown significant protective effects on the nervous system, but the biggest disadvantage of ARA290, its short half-life, limits its application. To address the short half-life issue, the researchers modified ARA290 with thioether cyclization to generate a thioether cyclized helical B peptide (CHBP). ARA290 and CHBP have promising applications as peptide drugs. The neuroprotective effects they exhibit have attracted continuous exploration of their mechanisms of action. This article will review the research on the role of EPO, ARA290 and CHBP in the nervous system around this developmental process, and provide a certain reference for the subsequent research.
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Erythropoietin , Neuroprotective Agents , Peripheral Nerve Injuries , Erythropoietin/therapeutic use , Humans , Peripheral Nerve Injuries/drug therapy , Animals , Neuroprotective Agents/therapeutic use , Neuroprotective Agents/pharmacology , Peptides/therapeutic use , Peptides/pharmacology , OligopeptidesABSTRACT
This study synthesized a carboxymethyl chitosan-modified bimetallic Co/Zn-ZIF (CZ@CMC) with strong hydrophilicity and adsorption performance via the one-pot method. Tetracycline hydrochloride (TCH) was used as the model contaminant to evaluate the adsorption and peroxymonosulfate (PMS) activation properties of CZ@CMC. Mechanism showed that the adsorption behavior occurred through pore filling, electrostatic attraction, surface complexation, hydrogen bonding, and π-π stacking. In addition, a CZ@CMC/PMS system was constructed, which had excellent catalytic performance. The hydrophilicity and selective adsorption properties of CMC conferred a greatly accelerated CZ@CMC in catalyzing the PMS process with kobs of 0.095 min-1, in which OH, 1O2, SO4-, O2-, and Co(III) were the main ROS which quenching tests, EPR, and chemical probe experiments verified. In addition, the degradation pathways of TCH were obtained utilizing DFT and HPLC-MS and analyzed to show that the system possessed a good detoxification capacity. This work is expected to provide a green, efficient, and stable strategy to enhance the adsorption properties of catalytic materials and subsequently their co-catalytic properties.
Subject(s)
Chitosan , Cobalt , Metal-Organic Frameworks , Tetracycline , Zinc , Chitosan/chemistry , Chitosan/analogs & derivatives , Cobalt/chemistry , Tetracycline/chemistry , Adsorption , Metal-Organic Frameworks/chemistry , Zinc/chemistry , Catalysis , Water Pollutants, Chemical/chemistry , Water Pollutants, Chemical/isolation & purification , Water Purification/methods , Hydrophobic and Hydrophilic Interactions , PeroxidesABSTRACT
Pulmonary arterial smooth muscle cells (PASMCs) functions are associated with the pathogenesis of pulmonary hypertension (PH) which is a life-threatening complication of acute pulmonary embolism (APE). This study sought to explore the expression pattern of microRNA (miR)-221-3p in APE-PH patients and its role in PASMCs proliferation and migration. The clinical data and venous blood of APE-PH patients were collected. The expression levels of miR-221-3p and phosphatase and tensin homolog (PTEN) in serum were determined, followed by receiver operator characteristic curve analysis of miR-221-3p diagnostic efficacy. PASMCs were transfected with miR-221-3p mimics and PTEN-overexpressed vector, followed by assessment of cell viability, proliferation, and migration through cell counting kit-8, 5-ethynyl-2'-deoxyuridine, Transwell, and wound healing assays. The binding between miR-221-3p and PTEN 3'UTR region was testified by the dual-luciferase assay. miR-221 was upregulated in the serum of APE-PH patients and presented with good diagnostic efficacy with 1.155 cutoff value, 66.25% sensitivity, and 67.50% specificity. miR-221 was negatively correlated with PTEN in APE-PH patients. miR-221 overexpression facilitated PASMCs proliferation and migration in vitro. miR-221-3p bound to PTEN 3'UTR region to decrease PTEN protein levels. PTEN overexpression abolished the promotive role of miR-221-3p in PASMCs. Overall, miR-221-3p targeted PTEN to facilitate PASMC proliferation and migration.
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Leakage is a high-incidence disease of embankment dams, and efficiently addressing this disease guarantees the safe operation of dams. Underwater leakage self-priming plugging technology is a new technology that utilizes the melting and solidifying characteristics of phase-change materials and the negative pressure in the leakage entry area to accurately plug the leakage. However, little is yet known about the underwater melting process of phase-change materials and how their characteristics influence the plugging effect. In this study, three kinds of phase-change materials, namely, paraffin, rosin, and stearic acid, were used to conduct underwater leakage self-priming plugging tests, observe and analyze the underwater melting process, and compare the plugging effects. The results showed that the underwater melting process of phase-change materials exhibited different plugging window periods depending on their melting points, specific heat capacities, and mobilities, which were the main factors affecting their plugging effects. In the final plugging stage, paraffin had the best plugging effect, but the material strength was low; rosin had good plugging compactness, but the fluidity performance was poor, and the material effective utilization was low; stearic acid had a low melting point but dispersed easily. Therefore, a blocking material with a suitable blocking window period can be produced by adjusting the material properties accordingly for an improved blocking effect.
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To promote the generalization ability of breast tumor segmentation models, as well as to improve the segmentation performance for breast tumors with smaller size, low-contrast and irregular shape, we propose a progressive dual priori network (PDPNet) to segment breast tumors from dynamic enhanced magnetic resonance images (DCE-MRI) acquired at different centers. The PDPNet first cropped tumor regions with a coarse-segmentation based localization module, then the breast tumor mask was progressively refined by using the weak semantic priori and cross-scale correlation prior knowledge. To validate the effectiveness of PDPNet, we compared it with several state-of-the-art methods on multi-center datasets. The results showed that, comparing against the suboptimal method, the DSC and HD95 of PDPNet were improved at least by 5.13% and 7.58% respectively on multi-center test sets. In addition, through ablations, we demonstrated that the proposed localization module can decrease the influence of normal tissues and therefore improve the generalization ability of the model. The weak semantic priors allow focusing on tumor regions to avoid missing small tumors and low-contrast tumors. The cross-scale correlation priors are beneficial for promoting the shape-aware ability for irregular tumors. Thus integrating them in a unified framework improved the multi-center breast tumor segmentation performance. The source code and open data can be accessed at https://github.com/wangli100209/PDPNet.
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Many reports have presented that in tight formation, the flow mechanism differs from a conventional reservoir, such as molecular diffusion, Pre-Darcy flow behavior, and stress sensitivity. However, for CO2 Huff-n-Puff development, it is a challenge to synthetically research these mechanisms. Considering the above flow mechanisms and offshore engineering background, the development plan optimization becomes a key issue. In this paper, a self-developed simulator that satisfies research needs is introduced. Then, based on experimental results, the simulation is launched to analyze the effects of CO2 diffusion, Huff-n-Puff period, and permeability heterogeneity. The results indicate that molecular diffusion makes a positive contribution to the oil recovery factor. Additionally, for offshore reservoirs, limited to the development cost and CO2 facilities corrosion, when the total Huff-n-Puff time is constant, the ratio of 0.5-1.0 between the Huff period and the Puff period in every cycle performs better. Finally, the greater heterogeneity in permeability is much more favorable for the CO2 Huff-n-Puff because of more intensive transport processes in formation. These different scenarios can increase the understanding of the CO2 Huff-n-Puff in tight oil offshore reservoirs.
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The exploration of the complex chemical diversity of bicyclo[n.1.1]alkanes and their use as benzene bioisosteres has garnered significant attention over the past two decades. Regiodivergent syntheses of thiabicyclo[4.1.1]octanes (S-BCOs) and highly substituted bicyclo[2.1.1]hexanes (BCHs) using a Lewis acid-catalyzed formal cycloaddition of bicyclobutanes (BCBs) and 3-benzylideneindoline-2-thione derivatives have been established. The first hetero-(4+3) cycloaddition of BCBs, catalyzed by Zn(OTf)2, was achieved with a broad substrate scope under mild conditions. In contrast, the less electrophilic BCB ester undergoes a Sc(OTf)3-catalyzed [2π+2σ] reaction with 1,1,2-trisubstituted alkenes, yielding BCHs with a spirocyclic quaternary carbon center. Control experiments and preliminary theoretical calculations suggest that the diastereoselective [2π+2σ] product formation may involve a concerted cycloaddition between a zwitterionic intermediate and E-1,1,2-trisubstituted alkenes. Additionally, the hetero-(4+3) cycloaddition may involve a concerted nucleophilic ring-opening mechanism.