The Impact of Problematic Internet Use on Adolescent Loneliness-Chain Mediation Effects of Social Support and Family Communication.

Purpose: To explore the relationship between adolescents' problematic Internet use and loneliness and the mediating roles of social support and family communication. Methods: A questionnaire survey of 2483 adolescents aged 12-17 years in 148 cities in China was conducted using the Problematic Internet Use Scale, the Collaborative Social Support Scale, the Family Communication Scale, and the Loneliness Scale. The data were statistically analyzed by SPSS 26.0 and validated by AMOS 28.0. Structural equation modelling (SEM) was conducted to test the effects of problematic Internet use on adolescents' loneliness and the mediating effects of perceptions of social support and family communication. Results: There was a significant positive effect of adolescents' problematic Internet use on loneliness (B-0.471, P<0.001), and the mediating effects of perceptual social support (0.003, 0.012) and family communication (0.008, 0.019) were found to play a chain effect between adolescents' problematic Internet use and loneliness, respectively. Use and feelings of loneliness played a chain mediating role (0.002, 0.006). Conclusion: This study identified the effects of adolescent problematic Internet use on loneliness and its mechanism of action, emphasized the importance of social support and family communication, and provided practical insights for improving family parenting styles and preventing and intervening in adolescent loneliness problems.

Clinical Performance of Immunonephelometric Assay and Chemiluminescent Immunoassay for Detection of IgG Subclasses in Chinese.

BACKGROUND: Detection of IgG subclasses (IgGSc) is vital for the diagnosis and management of disease, especially IgG4-related diseases (IgG4-RD). This study aimed to evaluate the performances of the chemiluminescent immunoassay (CLIA) for detecting IgGSc and diagnosing IgG4-RD by IgGSc. METHODS: A total of 40 individuals with IgG4-RD, 40 with primary Sjogren's syndrome (pSS), and 40 healthy controls (HCs) were enrolled. Serum samples were collected for the simultaneous detection of IgG1, IgG2, IgG3, and IgG4 by the Siemens immunonephelometric assay and the CLIA. The correlation analysis was performed, and diagnostic value was analyzed by the receiver operating characteristic (ROC) curve. RESULTS: Patients with IgG4-RD had higher IgG4 (p < 0.001) and lower IgG1 (p < 0.001) than those with pSS, and HC. The results by the Siemens immunonephelometric assay and the CLIA showed a strong correlation in detecting IgG1, IgG2, IgG3, and IgG4 (r = 0.937, r = 0.847, r = 0.871, r = 0.990, all p < 0.001, respectively). The sum of IgG1, IgG2, IgG3, and IgG4 using two assays strongly correlated with total IgG by the IMMAGE 800 (r = 0.866, r = 0.811, both p < 0.001, respectively). For discriminating IgG4-RD from pSS and HC, no significant differences were observed in CLIA IgG4 and Siemens immunonephelometric assay IgG4 (z = 0.138, p = 0.891), which provided the area under the curves (AUCs) of 0.951 (p < 0.001) and 0.950 (p < 0.001), respectively. The AUCs of CLIA IgG1 and Siemens immunonephelometric assay IgG1 in distinguishing pSS from IgG4-RD and HC were 0.761 (p < 0.001) and 0.765 (p < 0.001), respectively, with no significant differences (z = 0.228, p = 0.820). CONCLUSIONS: The CLIA and the Siemens immunonephelometric assay appeared to have good consistency with comparable diagnostic value in detecting IgGSc, especially IgG4, and IgG1 that can accurately identify IgG4-RD or pSS in clinical practice.

Tailoring Titanium Carbide Clusters for New Materials: from Met-Cars to Carbon-Doped Superatoms.

Tailoring materials with prescribed properties and regular structures is a critical and challenging research topic. Early transition metals were found to form supermagic M8C12 metallocarbohedrenes (Met-Cars); however, stable metal carbides are not limited to this common stoichiometry. Utilizing self-developed deep-ultraviolet laser ionization mass spectrometry, here, we report a strategy to generate new titanium carbides by reacting pure Tin clusters with acetylene. Interestingly, two products corresponding to Ti17C2 and Ti19C10 exhibit superior abundances in addition to the Ti8C12 Met-Cars. Using global-minimum search, the structures of Ti17C2 and Ti19C10 are determined to be an ellipsoidal D4d and a rod-shaped D5h geometry, respectively, both with carbon-capped Ti4C moieties and superatomic features. We illustrate the electronic structures and bonding nature in these carbon-doped superatoms concerning their enhanced stability and local aromaticity, shedding light on a new class of metal-carbide nanomaterials with atomic precision.

Predicting the risk of interstitial lung disease in patients with primary Sjögren's syndrome: Novel nomogram and elevated Th2 cells.

OBJECTIVE: Interstitial lung disease (ILD) is one of the most common pulmonary complications in patients with primary Sjögren's syndrome (pSS). This study was performed to identify immunological risk factors of pSS-associated ILD (pSS-ILD) and to further establish and evaluate of nomograms predicting the risk of ILD in patients with pSS. METHODS: A total of 622 patients with pSS (117 with ILD and 505 without lung involvement) and 166 healthy control subjects (HCs) were ultimately recruited to this retrospective study. Routine examination indicators, tumour markers and lymphocyte (LYMP) subpopulations were extracted. Simple and multiple logistic regressions analyses were performed to screen for independent predictors. Restricted cubic splines were used to examine associations of independent predictors with ILD, and a risk assessment model was constructed. A nomogram prediction model was developed, and receiver operating characteristic (ROC) curve analysis was performed to assess its performance. RESULTS: Univariate and multivariate logistic regression analyses showed that the older age, white blood cell (WBC) count, haemoglobin (HB) level, albumin (ALB) level, CA242 level, and the C-reactive protein (CRP)/LYMP ratio (CLR) were independent predictors of pSS-ILD in a linear manner, these factors were integrated and used to construct a nomogram prediction model. The model had clinical predictive value. In addition, the elevated Th2 cells proportion in pSS patients was significantly positively correlated with lung involvement, while it was negatively correlated with HB and ALB levels. Remarkably, the numbers of Th2 cells were correlated with the CLR in both pSS patients and those with pSS-ILD. CONCLUSIONS: Our novel ILD nomogram could be used to assess the risk of ILD in pSS patients with good discrimination ability. As well as, elevated peripheral blood Th2 cell levels may be related to ILD in patients with pSS.

To What Extent Do Iodomethane and Bromomethane Undergo Analogous Reactions?

Iodomethane and bromomethane (CH3I/CH3Br) are common chemicals, but their chemistry on nanometals is not fully understood. Here, we analyze the reactivity of Rhn+ (n = 3-30) clusters with halomethanes and unveil the spin effect and concentration dependence in the C-H and C-X bond activation. It is found that the reactions under halomethane-rich conditions differ from those under metal-rich conditions. Both CH3I and CH3Br undergo similar dehydrogenation on the Rhn+ clusters in the presence of small quantity reactants; however, different reactions are observed in the presence of sufficient CH3I/CH3Br, showing dominant Rh(CH3Br)x+ (x = 1-4) products but a series of RhnCxHyIz+ species (x = 1-4, y = 1-12, and z = 1-5) pertaining to H2, HI, or CH4 removal. Density functional theory calculations reveal that the dehydrogenation and demethanation of CH3Br are relatively less exothermic and will be deactivated by sufficient gas collisions if helium cooling takes away energy immediately; instead, the successive adsorption of CH3Br gives rise to a series of Rh(CH3Br)x+ species with accidental C-Br bond dissociation.

Research progress of metabolomics in cervical cancer.

INTRODUCTION: Cervical cancer threatens women's health seriously. In recent years, the incidence of cervical cancer is on the rise, and the age of onset tends to be younger. Prevention, early diagnosis and specific treatment have become the main means to change the prognosis of cervical cancer patients. Metabolomics research can directly reflect the changes of biochemical processes and microenvironment in the body, which can provide a comprehensive understanding of the changes of metabolites in the process of disease occurrence and development, and provide new ways for the prevention and diagnosis of diseases. OBJECTIVES: The aim of this study is to review the metabolic changes in cervical cancer and the application of metabolomics in the diagnosis and treatment. METHODS: PubMed, Web of Science, Embase and Scopus electronic databases were systematically searched for relevant studies published up to 2022. RESULTS: With the emergence of metabolomics, metabolic regulation and cancer research are further becoming a focus of attention. By directly reflecting the changes in the microenvironment of the body, metabolomics research can provide a comprehensive understanding of the patterns of metabolites in the occurrence and development of diseases, thus providing new ideas for disease prevention and diagnosis. CONCLUSION: With the continuous, in-depth research on metabolomics research technology, it will bring more benefits in the screening, diagnosis and treatment of cervical cancer with its advantages of holistic and dynamic nature.

The influence of media use degree on public depressive symptoms: mediating role of big five personality.

BACKGROUND: Mixed results have been found regarding the relationship between media use degree and depressive symptoms. The purpose of this study is to explore the relationship between media use degree, big five personality and depressive symptoms with a mediation model. METHOD: This was a cross-sectional study. With 9-item Patient Health Questionnaire (PHQ-9), 10-item Big Five Inventory (BFI-10) and self-designed media usage scale, 11,031 participants aged 12 and above in 120 cities in China were collected. Pearson correlation analysis and regression analysis were performed on the data. The Process plug-in was used to construct the mediation model and explore the relationship among media use degree, big five personality and depressive symptoms. The nonparametric percentile Bootstrap method was used to test the mediating effect of personality traits. RESULTS: The degree of media use was positively correlated with depressive symptoms (r = 0.20, P < 0.001), and big five personality played a mediating role between the degree of media use and depressive symptoms. Among five traits, extroversion (r=-0.12, P < 0.001), conscientiousness (r=-0.23, P < 0.001), openness (r=-0.03, P < 0.01) and agreeableness (r=-0.22, P < 0.001) were negatively correlated with depressive symptoms, and neuroticism (r = 0.25, P < 0.001) were positively correlated with depressive symptoms. In addition, extraversion (-0.004, -0.001), conscientiousness (-0.015, -0.008), agreeableness (-0.008, -0.001) and neuroticism (-0.015, -0.007) in big five personality played a mediating role between media use and depressive symptoms. CONCLUSION: The degree of media use positively predicted depressive symptoms, and excessive media use may bring risks to mental health. People with high neuroticism, low agreeableness, low conscientiousness and low extroversion are more likely to suffer from depressive symptoms.

Rh19-: A high-spin super-octahedron cluster.

Probing atomic clusters with magic numbers is of supreme importance but challenging in cluster science. Pronounced stability of a metal cluster often arises from coincident geometric and electronic shell closures. However, transition metal clusters do not simply abide by this constraint. Here, we report the finding of a magic-number cluster Rh19- with prominent inertness in the sufficient gas-collision reactions. Photoelectron spectroscopy experiments and global-minimum structure search have determined the geometry of Rh19- to be a regular Oh­[Rh@Rh12@Rh6]- with unusual high-spin electronic configuration. The distinct stability of such a strongly magnetic cluster Rh19- consisting of a nonmagnetic element is fully unveiled on the basis of its unique bonding nature and superatomic states. The 1-nanometer-sized Oh-Rh19- cluster corresponds to a fragment of the face-centered cubic lattice of bulk rhodium but with altered magnetism and electronic property. This cluster features exceptional electron-spin state isomers confirmed in photoelectron spectra and suggests potential applications in atomically precise manufacturing involving spintronics and quantum computing.

Resveratrol Attenuates Hydrogen Peroxide-induced Injury of Rat Ovarian Granulosa-lutein Cells by Resisting Oxidative Stress via the SIRT1/Nrf2/ARE Signaling Pathway.

INTRODUCTION: This paper aims to reveal the molecular mechanism of resveratrol against oxidative stress and cell injury. The ovarian granulosa-lutein cell injury and apoptosis induced by oxidative stress may be responsible for female luteal phase deficiency. The antioxidant function of resveratrol has been confirmed; however, its effect on the expression of antioxidant enzymes and regulatory mechanisms in ovarian granulosa-lutein cells remains unclear. OBJECTIVE: This study aimed to investigate the role of the SIRT1/Nrf2/ARE signaling pathway in the effect of resveratrol on the hydrogen peroxide-induced injury of rat ovarian granulosa-lutein cells. METHODS: In this study, ovarian granulosa-lutein cells extracted from 3-week female SD rats were treated with 200 µM H2O2 in the presence or absence of 20 µM resveratrol. siRNA-SIRT1 and siRNA-Nrf2 were used to inhibit the expression of SIRT1 and Nrf2, respectively. Cell counting kit 8 (CCK-8), cellular morphology, progesterone secretion, and estradiol were used to evaluate cell injury. Hoechst 33258 staining was used to measure cell apoptosis. DHE staining, DCFH-DA staining, malondialdehyde content, protein carbonyl content, total antioxidant capacity and SOD viability were used to estimate the levels of oxidative stress. Western blot analysis was used to detect the levels of apoptosis-related proteins, and SIRT1/Nrf2/ARE signaling pathway-related proteins. RESULTS: The H2O2 treatment-induced rat ovarian granulosa-lutein cells injury was shown as decreased cell viability, impaired cellular morphology, and decreased levels of progesterone and estradiol. The H2O2 treatment also exacerbated cell apoptosis demonstrated as more apoptotic cells stained by Hoechst staining, decreased level of anti-apoptosis protein Bcl-2 and increased level of pro-apoptosis protein Bax. These effects of cell injury and apoptosis induced by H2O2 can be ameliorated by resveratrol. Resveratrol also alleviated oxidative stress induced by H2O2, supported by decreased superoxide anion and cellular total ROS, decreased malondialdehyde and protein carbonyl levels, and increased total antioxidant capacity and SOD viability. Western blot results demonstrated resveratrol reversed the H2O2-induced decrease in levels of antioxidant enzymes containing ARE sequences and activated SIRT1/Nrf2 pathway. Further treatment by siRNA-Nrf2 suggested resveratrol could not activate the expression of antioxidant enzymes under a condition of inhibition of Nrf2. CONCLUSION: This study demonstrates that resveratrol attenuated oxidative stress to protect H2O2-induced rat ovarian granulosa-lutein cell injury and apoptosis via SIRT1/Nrf2/ARE signaling pathway.

Enhanced Stability of Rhombic Dodecahedron Nb15- with Well-Organized Superatomic States.

Well-resolved Nbn- clusters are produced and reacted with ethene and propene via a downstream flow tube reactor. Interestingly, the Nbn- clusters readily react with ethene and propene to form dehydrogenation products; however, Nb15- shows up in the mass spectra with prominent mass abundance indicating its inertness to react with olefins. For this cluster, we conduct photoelectron velocity map imaging (VMI) experiments and verify the stability of Nb15- within a highly symmetrical rhombic dodecahedron structure. Theoretical studies show that the stability of the Nb15- cluster is correlated with its superatomic nature pertaining to both geometric and electronic shell closures. Notably, the superatomic 1s orbital is dominated by the 5s electron of the central Nb atom, while the other superatomic orbitals are contributed by s-d hybridization, especially a remarkable contribution of s-dz2 hybridization. Apart from the closed shells, the highly symmetric geometry of Nb15- is associated with a regular polyhedral structure directed by all rhombus facets, embodying a magic number for body-centered dodecahedra, indicative of enhanced stability as a double magic cluster free of olefin adsorption.

IMPDH inhibition activates TLR-VCAM1 pathway and suppresses the development of MLL-fusion leukemia.

Inosine monophosphate dehydrogenase (IMPDH) is a rate-limiting enzyme in de novo guanine nucleotide synthesis pathway. Although IMPDH inhibitors are widely used as effective immunosuppressants, their antitumor effects have not been proven in the clinical setting. Here, we found that acute myeloid leukemias (AMLs) with MLL-fusions are susceptible to IMPDH inhibitors in vitro. We also showed that alternate-day administration of IMPDH inhibitors suppressed the development of MLL-AF9-driven AML in vivo without having a devastating effect on immune function. Mechanistically, IMPDH inhibition induced overactivation of Toll-like receptor (TLR)-TRAF6-NF-κB signaling and upregulation of an adhesion molecule VCAM1, which contribute to the antileukemia effect of IMPDH inhibitors. Consequently, combined treatment with IMPDH inhibitors and the TLR1/2 agonist effectively inhibited the development of MLL-fusion AML. These findings provide a rational basis for clinical testing of IMPDH inhibitors against MLL-fusion AMLs and potentially other aggressive tumors with active TLR signaling.

New strategies for the treatment of intervertebral disc degeneration: cell, exosome, gene, and tissue engineering.

Low back pain (LBP) caused by intervertebral disc (IVD) generation (IVDD) has always been an important problem that cannot be ignored. Traditional therapies have many deep-rooted and intractable complications that promote their treatment mode transfer to new therapies. This article mainly summarizes the shortcomings of traditional treatment methods and analyzes the research status and future development direction of IVDD treatment. We outlined the most promising IVDD therapies, including cell, exosome, gene, and tissue engineering therapy, especially tissue engineering therapy, which runs through the whole process of other therapies. In addition, the article focuses on the cellular, animal, and preclinical challenges faced by each therapeutic approach, as well as their respective advantages and disadvantages, to provide better ideas for relieving the IVDD patients' pain through new treatment methods.

Melatonin Attenuates H2O2-Induced Oxidative Injury by Upregulating LncRNA NEAT1 in HT22 Hippocampal Cells.

More research is required to understand how melatonin protects neurons. The study aimed to find out if and how long non-coding RNA (lncRNA) contributes to melatonin's ability to defend the hippocampus from H2O2-induced oxidative injury. LncRNAs related to oxidative injury were predicted by bioinformatics methods. Mouse hippocampus-derived neuronal HT22 cells were treated with H2O2 with or without melatonin. Viability and apoptosis were detected by Cell Counting Kit-8 and Hoechst33258. RNA and protein levels were measured by quantitative real-time PCR, Western blot, and immunofluorescence. Bioinformatics predicted that 38 lncRNAs were associated with oxidative injury in mouse neurons. LncRNA nuclear paraspeckle assembly transcript 1 (NEAT1) was related to H2O2-induced oxidative injury and up-regulated by melatonin in HT22 cells. The knockdown of NEAT1 exacerbated H2O2-induced oxidative injury, weakened the moderating effect of melatonin, and abolished the increasing effect of melatonin on the mRNA and protein level of Slc38a2. Taken together, melatonin attenuates H2O2-induced oxidative injury by upregulating lncRNA NEAT1, which is essential for melatonin stabilizing the mRNA and protein level of Slc38a2 for the survival of HT22 cells. The research may assist in the treatment of oxidative injury-induced hippocampal degeneration associated with aging using melatonin and its target lncRNA NEAT1.

Media use and organ donation willingness: A latent profile analysis from Chinese residents.

Background: Previous studies have paid attention to media as an important channel for understanding organ donation knowledge and have not divided groups according to the degree of media use to study their differences in organ donation. Therefore, the purpose of this study is to explore the influence of media use on organ donation willingness and the influencing factors of organ donation willingness of people with different media use levels. Methods: A cross-sectional study of residents from 120 cities in China was conducted by questionnaire survey. Using Mplus 8.3 software, the latent profile analysis of seven media usage related items was made, and multiple linear regression was performed to analyze the influence of varying levels of media use on organ donation willingness of different population. Results: All the interviewees were divided into three groups, namely, "Occluded media use" (9.7%), "Ordinary media use" (67.1%) and "High-frequency media use" (23.2%). Compared with ordinary media use, high-frequency media population (ß = 0.06, P < 0.001) were positively correlated with their willingness to accept organ donation, residents who used media occlusion (ß = -0.02, P < 0.001) were negatively correlated with their willingness to accept organ donation. The influencing factors of residents' accept willingness to organ donation were different among the types of occluded media use, ordinary media use and high-frequency media use. Conclusion: It is necessary to formulate personalized and targeted dissemination strategies of organ donation health information for different media users.

Plasma-Assisted Dinitrogen Activation on Small Cobalt Clusters: Co4 N9 + with Enhanced Stability.

We have performed a study on the accommodation of nitrogen doping toward superatomic states of transition metal clusters. By reacting cobalt clusters with N2 in the presence of plasma radiation, a large number of odd-nitrogen clusters were observed, typically Co3 N2m-1 + (m=1-5) and Co4 N2m-1 + (m=1-6) series, showing N≡N bond cleavage in the mild plasma atmosphere. Interestingly, the Co3 N7 + , Co4 N9 + , and Co5 N9 + clusters exhibit prominent mass abundances. First-principles calculation results elucidate the stability of the diverse cobalt nitride clusters and find unique stability of Co4 N9 + with a swallow-kite structure of which four coordinated N2 molecules causes a significantly enlarged HOMO-LUMO gap, while the single N atom doping gives rise to superatomic states of 1S2 1P3 ||1D0 . We reveal an efficient dinitrogen activation strategy by reacting multiple N2 molecules with cobalt clusters under a plasma atmosphere.

Fabrication and characterization of Pickering high internal phase emulsions stabilized by debranched starch-capric acid complex nanoparticles.

High internal phase emulsions (HIPEs) stabilized by debranched starch-capric acid (DBS-CA) complex nanoparticles were fabricated and their performance was evaluated. DBS-CA was prepared through enzymatic debranching and solid encapsulation methods, and displayed V-type crystalline structure. Contact angle measurements show enhanced hydrophobicity of DBS-CA compared to native starch. The DBS-CA nanoparticles have an average size of 463.77 nm and tended to be aggregating as analyzed by scanning electron microscope and dynamic light scattering particle size analysis. When used as a particulate emulsifier, DBS-CA could stabilize HIPEs with oil volume fraction as high as 80%. The HIPEs showed pH-dependent properties; good storage stability and mechanical strength were achieved within pH range from 3 to 11, especially under alkaline conditions. It was proposed that smaller particle size and higher surface charging were responsible for the more tightly connected gel structure and thus their performance. This study demonstrates a novel approach to fabricate food-grade Pickering HIPEs, which may have many promising potential applications in the food industry.

Ladder Oxygenation of Group VIII Metal Clusters and the Formation of Metalloxocubes M13O8.

The diversity of valence and bonding of transition metals makes their oxidation processes perplexing at reduced sizes. Here we report a comprehensive study on the oxidation reactions of rhodium clusters Rhn± (n = 3-30) and find that Rh3,4O4+, Rh5-7O6+, and Rh8-13O8+ always dominate the mass distributions showing size-dependent ladder oxygenation which is closely associated with the O-binding modes. While the Rh8-13O8+ clusters display a µ3-O binding mode (hollow site adsorption), Rh3-4O4+ and Rh5-7O6+ favor the µ2-O binding mode (edge-site adsorption) or a mixture of the two modes. The µ3-O binding mode is inclined to yield a cubic Rh13O8, while the µ2-O binding mode gives rise to oxygen-bridge protection for the metal clusters. Such ladder oxidation was also observed for Ptn+, Fen+, Con+, and Nin+ clusters. We propose a three-dimensional diagram for the oxidation states and O-binding modes of metals, and highlight the metalloxocubes M13O8+ for cluster-genetic materials.

Gas-phase preparation and the stability of superatomic Nb11O15.

We report a study of the reactions of pure metal clusters Nbn- with dioxygen in the gas phase. It is found that the presence of low-concentration dioxygen reactants results in oxygen-addition products, whereas sufficient high-concentration dioxygen enables oxygen-etching reactions giving rise to molecular niobium oxides. Interestingly, in the presence of a suitable gas flow rate of an intermediate dioxygen concentration, a highly selective product Nb11O15- shows up in the mass spectra. Utilizing density functional theory (DFT) calculations, we have discussed the reactivities of Nbn- (3 ≤ n ≤ 14) clusters with oxygen, and unveiled the reasonable stability of Nb11O15- pertaining to its unique geometric structure with a D5h Nb@Nb10 core fully protected by 15 bridge-oxygen atoms. The oxygen-passivated Nb@Nb10O15- cluster exhibits a large HOMO-LUMO gap (1.46 eV) and effective multicenter bonds with remarkable superatom orbitals for all the 26 valence electrons of the Nb@Nb10 core corresponding to well-staggered energy levels. We illustrate the superatomic features in the Nb@Nb10 metallic core for which the adaptive natural density partitioning (AdNDP) analysis unveils thirteen 11c-2e bonds. Among them, one of the 11c-2e bonds accounts for the superatomic S orbital, three bonds correspond to superatomic P orbitals, another five display vivid D orbital characteristics, and the remaining four 11c-2e bonds are assigned to F orbital features. In addition, the net atomic charge of the center Nb atom is as high as -0.804 |e| rendering core-shell electrostatic interactions and the shielding effect of the Nb10O15 shell.

Probing Cluster-π Interactions between Cun- and C2H2/C2H4 for Gas Separation.

Copper-related materials are used for separation of ethylene and acetylene gases in chemistry; however, the precise mechanism regarding selectivity is elusive to be fully understood. Here, we have conducted a joint experimental and theoretical study of the Cun- (n = 7-30) clusters in reacting with C2H4 and C2H2. It is found that all of the Cun- clusters readily react with C2H2, giving rise to C2H2-addition products; however, Cu18- and Cu19- do not react with C2H4. We illustrate the superatomic stability of Cu18- and advocate its availability to separate C2H4 from C2H2. Further, we demonstrate the atomically precise mechanism regarding selectivity by fully unveiling the size-dependent cluster-π interactions.