Celebrity CEOs, digital transformation and firm performance in China: the moderating role of controlling shareholders and institutional investors

Background

business leaders' social status significantly impacts companies' strategic direction and performance. Digital transformation, an important tool for companies to enhance competitiveness and resilience, plays an important role in the relationship between executive background and firm performance.

Objective

To investigate the impact of celebrity chief executive officers (CEO) on firm performance through digital transformation.

Method

Using data from companies listed on the main boards of the Shanghai and Shenzhen Stock Exchanges between 2017 and 2021, this study explored the relationship between celebrity CEOs, digital transformation, and firm performance.

Result

Celebrity CEOs significantly enhanced a firm's digital transformation. However, this effect weakened when controlling shareholders and institutional investors held more shares. Additionally, the study showed that celebrity CEOs can improve firm performance through digital transformation. These findings were robust across a range of sensitivity analyses.

Conclusion

This study contributes to understanding celebrity CEOs' decision-making motivations and economic impacts from a psychological perspective while also providing valuable insights for driving digital transformation within companies.

Assembly of dysprosium(III) cubanes in a metal-organic framework with an ecu topology and slow magnetic relaxation

A dysprosium(III) metal-organic framework constructed using dysprosium(III) cubanes as secondary building units has been reported to exhibit field-induced slow magnetic relaxation behavior and an unprecedented ecu topology, which is the first example of an 8-connected Ln-cubane-based framework material and a rare Dy4-MOF showing slow magnetic relaxation.

Binuclear cobalt(II) and two-dimensional manganese(II) coordination compounds self-assembled by mixed bipyridine-tetracarboxylic ligands with single-ion magnet properties

A cobalt(II) complex and manganese(II) coordination polymer, formulated as [Co2(H2btca)(mbpy)4][H2btca]·4H2O (1) and {Mn2(btca)(mbpy)2(H2O)2}n (2) (H4btca = 1,2,4,5-benzenetetracarboxylic acid; mbpy = 4,4'-dimethyl-2,2'-bipyridyl), constructed by mixed bipyridine-tetracarboxylic ligands were synthesized and characterized. Single-crystal structural analyses reveal that compound 1 is a discrete neutral binuclear molecule, while compound 2 is a two-dimensional (2D) coordination polymer. The metal ions in these compounds are well isolated, with an intramolecular Co2+⋯Co2+ distance of 9.170 Å for 1 and Mn2+⋯Mn2+ separation of 10.984 and 11.164 Å for 2 due to the bulk tetracarboxylic linker. This isolation gives rise to a single-ion magnetism origin of the compounds. Magnetic studies reveal a large zero-field splitting parameter D of 82.6 cm-1 for 1, while a very small D of 0.42 cm-1 was observed for 2. Interestingly, dynamic ac magnetic measurements exhibited slow magnetic relaxation under the external dc field of the two compounds, revealing the field-supported single-ion magnet (SIM) of 1 and 2. The detailed theoretical calculations were further applied to understand the electronic structures, magnetic anisotropy, and relaxation dynamics in 1 and 2. Combined with our recently reported compound (Eur. J. Inorg. Chem., 2022, e202200354), the foregoing results provide not only a rare binuclear cobalt(II) SIM and the first 2D manganese(II) SIM coordination polymer but also a bipyridine-tetracarboxylic ligand approach toward novel SIMs.

Carborane based chalcogen-fused phenazines for visible light induced ATRP

A series of carborane derivatives (o-CB-DPE, E = O, S, Se) were synthesized through a combining of the σ characteristic o-carborane and chalcogen-fused phenazines. The UV-Vis spectroscopy and cyclic voltammetry results showed that o-CB-DPEs have a visible light absorption (λ > 390 nm), narrow energy gap (∼2.93 eV), and stable radical cation species. The radical cation formation process of these was proved by spectroelectrochemistry and chemical oxidation with AgSbF₆. Based on the above advantages, o-CB-DPS showed an excellent performance on ATRP (Đ = 1.12, C_(MMA) = 97%) due to the long radical cation lifetime (700 s). These results prove that combining carborane and chalcogen-fused phenazine is a feasible method to improve the efficiency of metal-free photocatalytic ATRP.

The impact of corporate digital strategic orientation on innovation output

Given the development of the digital economy, the shift to digitalization is an inevitable direction for corporate strategic planning. This empirical study investigates the impact of corporate digital strategic orientation on innovation output. It also examines the moderating effects of executive equity and compensation incentives on the relationship between corporate digital strategic orientation and innovation output. We selected a sample of Chinese listed companies and adopted the Heckman two-stage and two-stage least square (2 S LS) methods to control for potential endogenous problems. Our findings indicate that corporate digital strategic orientation significantly enhances innovation output. Additionally, we found that executive compensation and equity incentives positively moderate the impact of corporate digital strategic orientation on innovation output, with equity incentives having a greater moderating effect than compensation incentives. Further analysis shows that the impact of corporate digital strategic orientation on innovation output is greater in non-manufacturing industries and non-state-owned enterprises. Our study provides policy insights on how companies can enhance their innovation capability in the digital economy.

A porous cobalt(II)-organic framework exhibiting high room temperature proton conductivity and field-induced slow magnetic relaxation

A two-dimensional (2D) cobalt(II) metal-organic framework (MOF) constructed by a ditopic organic ligand, formulated as {[Co(Hbic)(H₂O)]·4H₂O}_n (1) (H₂bic = 1H-benzimidazole-5-carboxylic acid), was hydrothermally synthesized and structurally characterized. Single-crystal X-ray diffraction shows that the distorted octahedral Co²⁺ ions, as coordination nodes, are bridged to form 2D honeycomb networks, which are further organized into a 3D supramolecular porous framework through multiple hydrogen bonds and interlayer π-π interactions. Dynamic crystallography experiments reveal the anisotropic thermal expansion behavior of the lattice, suggesting a flexible hydrogen-bonded 3D framework. Interestingly, hydrogen-bonded (H₂O)₄ tetramers were found to be located in porous channels, yielding 1D proton transport pathways. As a result, the compound exhibited a high room-temperature proton conductivity of 1.6 × 10^-4 S cm^-1 under a relative humidity of 95% through a Grotthuss mechanism. Magnetic investigations combined with theoretical calculations reveal giant easy-plane magnetic anisotropy of the distorted octahedral Co²⁺ ions with the experimental and computed D values being 87.1 and 109.3 cm^-1, respectively. In addition, the compound exhibits field-induced slow magnetic relaxation behavior at low temperatures with an effective energy barrier of U_eff = 45.2 cm^-1. Thus, the observed electrical and magnetic properties indicate a rare proton conducting SIM-MOF. The foregoing results provide a unique bifunctional cobalt(II) framework material and suggest a promising way to achieve magnetic and electrical properties using a supramolecular framework platform.

Three New MnII-[MoIII(CN)7]4– Molecular Magnets Constructed from Chiral Bidentate Chelating Ligands

Three new cyanide-bridged compounds {[Mn((S,S)-Dpen)]3[Mn((S,S)-Dpen)(H2O)][Mo(CN)7]2·4H2O·4C2H3N}n (1-SS), {[Mn((R,R)-Dpen)]3[Mn((R,R)-Dpen)(H2O)][Mo(CN)7]2·4.5H2O·4C2H3N}n (1-RR), and {[Mn(Chxn)][Mn(Chxn)(H2O)0.8]-[Mo(CN)7]·H2O·4C2H3N}n (2) (SS/RR-Dpen = (S,S)/(R,R)-1,2-diphenylethylenediamine and Chxn = 1,2-cyclohexanediamine) have been successfully synthesized from the self-assembly reaction of the [MoIII(CN)7]4– unit,...

Supramolecular encapsulation of hexaaquacobalt(II) cations in a hydrogen-bonded framework for slow magnetic relaxation and high proton conduction

The supramolecular assembly of hexaaquacobalt(II) nitrate and a tetradentate carboxylate ligand resulted in the isolation of a cobalt hydrogen-bonded organic framework (HOF). Variable-temperature X-ray diffraction experiments reveal high thermal stability of the framework sustained by charge-assisted, multiple hydrogen bonding interactions with the co-former. Interestingly, the material shows field-induced slow relaxation of magnetization originating from the magnetically anisotropic Co²⁺ ions within the supramolecular framework, revealing a rare single-ion magnet (SIM) HOF. Additionally, the HOF also exhibits high proton conductivity above 100 °C due to the extensive H-bond networks and high content of water and carboxylate within the material. More importantly, these results not only observe the magnetic and electrical properties of an old molecule but also demonstrate a significant turn-on effect of multifunctionalities from non-functional synthons achieved in a supramolecular approach.

A single-ion magnet building block strategy toward Dy2 single-molecule magnets with enhanced magnetic performance

A molecular dysprosium(III) complex [Dy(DClQ)₃(H₂O)₂] (1) was used as a building unit for the construction of lanthanide SMMs, leading to the isolation of two dinuclear Dy(III) complexes, namely [Dy₂(DClQ)₆(MeOH)₂] (2) and [Dy₂(DClQ)₆(bpmo)₂]·6MeCN (3) (DClQ = 5,7-dichloro-8-hydroxyquinoline, bpmo = 4,4'-dipyridine-oxide). Structural analyses revealed the same N₃O₅ coordination environment of the Dy(III) centers with a distorted biaugmented trigonal prism (C_2V symmetry) and triangular dodecahedron (D_2d symmetry) for 2 and 3, respectively. Magnetic studies revealed the presence of ferromagnetic and weak antiferromagnetic exchange interactions between the Dy³⁺ centers in 2 and 3, respectively. Interestingly, slow relaxation of magnetization at zero fields was evidenced with an U_eff of 51.4 K and 159.0 K for complexes 2 and 3, respectively. The detailed analysis of relaxation dynamics discloses that the Orbach process is dominant for 2 whereas Raman and QTM play an important role in 3. Theoretical calculations were carried out to provide insight into the magnetic exchange interactions and relaxation dynamics for the complexes. Due to a single-ion magnet (SIM) of 1, the foregoing results demonstrate a SIM modular synthetic route for the preparation of dinuclear lanthanide SMMs.

Celebrity CEOs and firm innovation investment: Evidence from Chinese-listed companies

In today’s commercial-oriented world, intense social attention makes it easier for CEOs to become celebrities. This social escalation and characteristic change of CEOs into celebrities tend to influence their motivation and behavior, and thus the strategic decisions and results of firms. Despite the significance of recognizing CEOs’ social identity, the impact of celebrity CEOs on innovation strategy remains unknown. Integrating identity and upper echelons theories, this study examines and provides empirical evidence on how celebrity CEOs affect firm innovation investment using data of Chinese listed companies from 2015 to 2020. We argue that celebrity CEOs’ engagement in innovation investment is driven by their motivation for preserving celebrity status. Further, we show that analyst coverage plays a positive moderating role between celebrity CEOs and innovation investment, and the positive effect of celebrity CEOs on innovation investment becomes weaker in state-owned enterprises. This study confirms the important role of CEOs’ specific social identity in firm innovation strategy, which is motivated by celebrity CEOs’ attempt to maintain their established status and reputation. The results expand the research on the influencing factors of firm innovation investment that focus on executives’ social characteristics. They also provide managerial implications for board of directors to recruit and supervise a celebrity CEO.

A proton conducting cobalt(II) spin crossover complex

Spin crossover (SCO) complexes have been extensively explored as bistable materials and recently used as molecular modules for the development of new multifunctional molecular magnetic materials. Herein, we present the synthesis, crystal structure, magnetic, and electrical properties of a mononuclear cobalt complex constructed by a halogen-functionalized terpyridine derivative and organosulfonate. A complete and gradual spin transition with the T 1/2 = 200 K was observed for the Co 2+ ions through both the magnetic measurement and dynamic crystallographic experiments. Interestingly, considerable room temperature proton conductivity of 6.9×10 -5 S cm -1 under 98% relative humidity was evidenced because of the presence of sulfonate-assisted hydrogen-bonded proton hopping pathways. The forgoing results not only provide an unprecedented proton conducting cobalt(II) SCO complex but also a promising way for the design and construction of bifunctional SCO molecular conductors via the incorporation of SCO transition and proton conduction.

LAG3 blockade coordinates with microwave ablation to promote CD8+ T cell-mediated anti-tumor immunity

Background

The immune checkpoint inhibitors (ICIs) combined with other therapeutic strategies have shown exciting results in various malignancies, and ICIs have now become the gold standard for current cancer treatment. In several preclinical and clinical investigations, ablation coupled with immunotherapy has proved to be quite effective. Our previous studies have shown that ablation coupled with ICI is a potential anti-cancer regimen for colorectal cancer liver metastases (CRLM). Furthermore, we have reported that following microwave ablation (MWA), the expression of LAG3 is up-regulated in tumor microenvironment (TME), indicating that LAG3 is implicated in the regulation of immunosuppressive immune response, and combination therapy of MWA and LAG3 blockade can serve as a promising therapeutic strategy against cancer.

Methods

The expression of LAG3 was investigated in this study utilizing a preclinical mouse model treated with MWA. Moreover, we monitored the tumor development and survival in mice to assess the anti-cancer effects of MWA alone or in combination with LAG3 blockade. Flow cytometry was also used to phenotype the tumor-infiltrating lymphocytes (TILs) and CD8⁺ T cell effector molecules. We finally analyzed the single-cell RNA sequencing (scRNA-seq) data of infiltrating CD45⁺ immune cells in the tumors from the MWA alone and MWA combined with LAG3 blockade groups.

Results

After MWA, the expression of LAG3 was up-regulated on sub-populations of TILs, and introducing LAG3 blockade to MWA postponed tumor development and extended survival in the MC38 tumor model. Flow cytometry and scRNA-seq revealed that LAG3 blockade in combination with MWA markedly boosted the proliferation and the function of CD8⁺ TILs, leading to altered myeloid cells in the TME.

Conclusion

Combination therapy of LAG3 blockade and MWA was a unique therapeutic regimen for some solid tumors, and such combination therapy might reprogram the TME to an anti-tumor manner.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-022-03646-7.

Identification of the active compounds and functional mechanisms of Jinshui Huanxian formula in pulmonary fibrosis by integrating serum pharmacochemistry with network pharmacology

BACKGROUND

Jinshui Huanxian formula (JHF), a traditional Chinese medicine (TCM), has been demonstrated to attenuate idiopathic pulmonary fibrosis (IPF). The active compounds and underlying mechanisms of JHF, however, are unclear.

PURPOSE

The purpose of This study was to aimed to identify the active compounds and pharmacological mechanism of JHF by integrating serum pharmacochemistry with a network pharmacology strategy.

METHODS

JHF was orally administered to a rat model with bleomycin (BLM)-induced pulmonary fibrosis (PF). The pharmacodynamic effects and compounds present in the serum were identified. The targets and biological mechanisms of these compounds were revealed using network analysis and validated using in vitro experiments.

RESULTS

JHF could significantly ameliorate BLM-induced PF by preventing extracellular matrix collagen deposition. Twenty-seven compounds that were found to be enriched in the serum samples collected 1 h after oral administration with JHF were identified as the candidate active compounds, and their 423 potential targets were identified as JHF targets. primarily related to the advanced glycation and products-receptor for advanced glycation end products (AGE-RAGE) signaling pathway, phosphatidylinositol 3 kinase (PI3K)-protein kinase B (PKB or AKT) signaling pathway, epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor resistance, etc. The 423 targets, 1145 IPF-related genes and their overlapped genes were applied to analyze, respectively. The results showed that these genes were primarily related to the advanced glycation end-products-receptor for advanced glycation end-products (AGE-RAGE) signaling pathway, lipid and atherosclerosis pathology, phosphatidylinositol 3 kinase (PI3K)-protein kinase B (PKB or AKT) signaling pathway, and epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor resistance. Furthermore, the affinity between serum JHF compounds and the main proteins in the above important pathways was investigated through molecular docking. As a result, Molecular docking analysis showed that, tangeretin, isosinensetin, and peimine were found to could bind to EGFR and AKT, and their inhibitory effect on EGFR and AKT were validated in fibroblast cell induced by transforming growth factor (TGF)TGF-β. The results indicated that suppression of fibroblast activation by inhibiting the EGFR/PI3K/AKT signaling pathway might be an important mechanism of JHF may to treat PF.

CONCLUSION

JHF may suppress fibroblast activation by inhibiting the EGFR/PI3K/AKT signaling pathway to ameliorate PF. Tangeretin, isosinensetin, and peimine may be the active compounds in JHF involved in the treatment of that have therapeutic effects on IPF.

Impact of Managerial Reputation and Risk-Taking on Enterprise Innovation Investment From the Perspective of Social Capital: Evidence From China

China’s enterprises established in the emerging economy are relatively short of technological innovation resources; therefore, these enterprises need to make use of managerial reputation to break through organizational boundaries in order to obtain richer social capital and reshape their technological creativity to cope with the complex and a changeable international economic situation. This corporate phenomenon also serves as the key for China’s economy to advance to the stage of high-quality development. Based on the panel data of Chinese A-share listed companies from 2007 to 2016, this paper adopts the Heckman two-stage evaluation model to empirically study the impact of managerial reputation on enterprise innovation activities, the moderating role of corporate governance, and the mediating role of risk taking. From the standpoint of social capital, the findings indicate that managerial reputation promotes enterprise innovation investment. The mechanism test reveals that this correlation is realized through the mediating role of risk taking. Furthermore, the promotion effect of management reputation on enterprise innovation investment is stronger when the enterprises adopt the CEO duality, the larger board size, higher management ownership, and stronger equity restriction. The conclusions of this study confirm the important role of social capital in enterprise innovation in the context of the Chinese economy. The study implications also enrich and expand the research on the influencing factors of enterprise innovation investment that focus on the managerial reputation and provide important business inspiration for enterprises to build reputation management strategy and promote the transformation and upgrading of local enterprises.

Oral Microbiota, a Potential Determinant for the Treatment Efficacy of Gastric Helicobacter pylori Eradication in Humans

The oral cavity serves as another reservoir for gastric Helicobacter pylori and may contribute to the failure of gastric H. pylori eradication therapy. However, changes to the oral microbial composition after gastric H. pylori eradication therapy has not yet been identified. This study aims to dissect whether the oral microbiota is involved and which bacterium mediates the clinic failure in H. pylori eradication. In the present study, the oral microorganisms from patients who had received the gastric H. pylori eradication treatment were analyzed by a high-throughput 16S rRNA deep sequencing. We found that the β diversity and composition of oral microbiota were remarkably changed in the patients who had experienced successful gastric H. pylori eradication treatment (SE group) compared to the failure group (FE group). Significantly enriched families, including Prevotellaceae, Streptococcaceae, Caulobacteraceae, and Lactobacillaceae, were detected in the SE group. In contrast, the bacterial families, such as Weeksellaceae, Neisseriaceae, Peptostreptococcaceae, Spirochaetaceae, and Veillonellaceae, were abundantly expressed in the FE group. Five operational taxonomic units (OTUs) were positively correlated with DOB values, while two OTUs exhibited negative trends. These different enriched OTUs were extensively involved in the 20 metabolic pathways. These results suggest that a balanced environment in the oral microbiota contributes to H. pylori eradication and metabolic homeostasis in humans. Our data demonstrated that the changes in oral microbiota might contribute to the therapeutic effects of antibiotic therapy. Therefore, a different therapy on the detrimental oral microbiota will increase the therapeutic efficacy of antibiotics on H. pylori infection.

[Consensus of experts on the medical risk prevention for the patients with cardiovascular diseases during dental treatment (2022 edition)]

With the aging process of population in the society, the prevalence of cardiovascular diseases (CVD) in China is increasing continuously and the number of dental patients with CVD is increasing gradually too. Due to the lack of guidelines for dental patients with CVD in our country, how to implement standardized preoperative evaluation and perioperative risk prevention remains a problem to be solved for dentists at present. The present expert consensus was reached by combining the clinical experiences of the expert group of the Fifth General Dentistry Special Committee, Chinese Stomatological Association and respiratory and cardiology experts in diagnosis and treatment for CVD patients, and by systematically summarizing the relevant international guidelines and literature regarding the relationship between CVD and oral diseases and the diagnosis and treatment of dental patients with heart failure, hypertension and antithrombotic therapy. The consensus aims to provide, for the dental clinicians, the criteria on diagnosis and treatment of CVD in dental patients in China so as to reduce the risk and complications, and finally to improve the treatment levels of dental patients with CVD in China.

[AuI(CN)2]-Armed [FeIII2FeII2] Square Complex Showing Unusual Spin-Crossover Behavior Due to a Symmetry-Breaking Phase Transition

The incorporation of two different cyanide building blocks of [(Tp^R)Fe^III(CN)₃]^- and [Au^I(CN)₂]^- into one molecule afforded a novel hexanuclear [Fe^III₂Fe^II₂Au^I₂] complex (1·2Et₂O), in which the cyanide-bridged [Fe^III₂Fe^II₂] square was further grafted by two [Au^I(CN)₂]^- fragments as long arms in syn orientations. Complex 1·2Et₂O undergoes a gradual spin crossover (SCO) ffrom low-spin (LS) to high-spin (HS) state for the Fe(II) centers upon desolvation. Remarkably, its desolvated phase (1) exhibits a reversible but atypical two-step (sharp-gradual) SCO behavior with considerable hysteresis (21 K). Variable-temperature single-crystal X-ray structural studies reveal that the hysteretic spin transition takes place synchronously with the concerted displacive motions of the molecules, representing another rare example including multistep and hysteretic spin transitions due to the synergetic SCO and structural phase transition.

Is It a "Colon Perforation"? A Case Report and Review of the Literature

Background

Intrauterine devices (IUDs) are commonly used as a contraceptive method. IUD migration and colon perforation are rare but serious complications occurring sometimes years after insertion.

Case

A 42-year-old woman with complaints of slight abdominal pain underwent a colonoscopy. Colonoscopy showed that a "nail" had penetrated the ascending colon wall and that an arm of the "nail" was embedded in the colon wall. We did not remove the "nail" rashly under colonoscopy. Considering the safety and effectiveness of the patient's operation, we were able to remove the "nail" easily by performing laparoscopic-endoscopic cooperative surgery (LECS) combined with hysteroscopy at the same time.

Conclusion

We report a case of successful removal of a colonic perforation device by colonoscopy, laparoscopy, and hysteroscopy, which is the first method used.

Hydrogen-Bonded Framework of a Cobalt(II) Complex Showing Superior Stability and Field-Induced Slow Magnetic Relaxation

A unique hydrogen-bonded organic-inorganic framework (HOIF) constructed from a mononuclear cobalt(II) complex, [Co(MCA)₂·(H₂O)₂] (HMCA = 4-imidazolecarboxylic acid), via multiple hydrogen-bonding interactions was synthesized and structurally characterized. The Co(II) center in the HOIF features a highly distorted octahedral coordination environment. Remarkably, the Co^II HOIF showed permanent porosity with superior stability as established by combined thermogravimetric analysis (TGA), variable-temperature infrared spectra (IR), variable-temperature powder X-ray diffraction data (PXRD), and a CO₂ isotherm. Structural studies reveal that short multiple hydrogen bonds should be responsible for the superior thermal and chemical stability of a HIOF. Magnetic investigations reveal the large easy-plane magnetic anisotropy of the Co²⁺ ions with the fitted D values being 22.1 (magnetic susceptibility and magnetization data) and 29.1 cm^-1 (reduced magnetization data). In addition, the HOIF exhibits field-induced slow magnetic relaxation at low temperature with an effective energy barrier of U_eff = 45.2 cm^-1, indicative of a hydrogen-bonded framework single-ion magnet of the compound. The origin of the significant magnetic anisotropy of the complex was also understood from computational studies. In addition, BS-DFT calculations indicate that the superexchange interactions between the neighboring Co^II ions are non-negligible antiferromagnetism with J_Co-Co = -0.5 cm^-1. The foregoing results provide not only a carboxylate-imidazole ligand approach toward a stable HOIF but also a promising way to build a robust single-ion magnet via hydrogen-bond interactions.

Water-driven reversible switching of single-ion magnetism and proton conduction in a dysprosium sulfonate

We report the design and synthesis of a one-dimensional Dy(III) coordination polymer, comprised of sulfonate functionalized ligand 8-Hydroxyquinoline-5-sulfonic acid (H2SQ) and Dy3+ ions, with hydrogen-bonded supramolecular 3D structure. Interestingly, the...

Field-induced slow magnetic relaxation behaviours in binuclear cobalt(II) metallocycle and exchange-coupled cluster

Precise control of structures and magnetic properties of a molecular material constitutes an important challenge to realize the tailor-made magnetic function. Herein, we reported that the ligand-directed coordination self-assembly of...

Manipulating the spin crossover behaviour in a series of cyanide-bridged {FeIII2FeII2} molecular squares through NCE- co-ligands

Manipulating the transition temperature (T1/2) of spin-crossover (SCO) complexes capable of fulfilling practical criteria through different synthetic strategies is one of the main focuses in the field of molecular magnetism....

Tuning chain topologies and magnetic anisotropy in one-dimensional cobalt(II) coordination polymers via distinct dicarboxylates

Based on a terpyridine derivative and two different dicarboxylate ligands, two new cobalt(II) coordination polymers, namely [Co(pytpy)(DClbdc)]n (1) and [Co(pytpy)(ndc)]n (2) (pytpy = 4'-(4-Pyridyl)-2,2':6',2''-terpyridine, H2DClbc = 2,5-Dichloroterephthalic acid, and H2ndc...

Tuning the structure and magnetic properties via distinct pyridine derivatives in cobalt(II) coordination polymers

Precise modulation of the structure and magnetic properties of coordination compounds is of great importance in the development of framework magnetic materials. Herein, we report that the coordination self-assembly of a neutral cobalt(II) magnetic building block and selective pyridine derivatives as organic linkers has led to two distinct cobalt(II) coordination polymers, {Co(DClQ)₂(bpy)}_n (1) and {Co₂(DClQ)₄(tpb)}_n (2) (DClQ = (5,7-dichloro-8-hydroxyquinoline; bpy = 4, 4'-dipyridine; tpb = 1,2,4,5-tetra(4-pyridyl)benzene)). Structural analyses revealed that 1 and 2 are one-dimensional (1D) and 2D coordination polymers containing the same neutral magnetic building block [Co(DClQ)₂] bridged by bitopic bpy and tetratopic tpb ligands, respectively. Both the complexes have a distorted octahedral CoN₄O₂ coordination geometry around each cobalt center offered by the bidentate ligand and organic linkers. Magnetic studies reveal large easy-plane and easy-axis magnetic anisotropy for 1 and 2, respectively. However, because of the weak antiferromagnetic coupling between the bpy-bridged Co^II centers, no slow relaxation of the magnetization was observed in 1 under both zero or applied dc fields. Interestingly, complex 2 exhibits slow magnetic relaxation under external fields, indicative of a framework single-ion magnet of 2. Theoretical calculations further support the experimental results and unveil that the D values are +65.3 and -91.2 cm^-1 for 1 and 2, respectively, while the magnetic exchange interaction was precisely estimated as -0.16 (1) and -0.009 (2) cm^-1. The foregoing results show that the structural dimensionality and magnetic properties can be rationally modified via pre-designed magnetic building blocks and a suitable choice of organic bridging ligands.

An Azido-Bridged Dysprosium Chain Complex Showing Zero-field Slow Magnetic Relaxation

A one-dimensional (1D) azido-bridged dysprosium coordination polymer featuring a zig-zag chain structure constructed from a halogen-functionalized quinoline derivative and N₃ ^- ligands was structurally and magnetically characterized. Magnetic studies revealed that the chain complex exhibits zero-field slow magnetic relaxation and a significant butterfly-like hysteresis loop, originating from highly magnetic anisotropy of the Dy³⁺ ions in a D_4d symmetry. This compound represents the first azido-bridged lanthanide chain showing zero-field slow magnetic relaxation behavior. These results highlight that the combination of high symmetric Ln³⁺ ions with the versatile azido bridging ligand provides an effective approach for the design and construction of advanced lanthanides molecular magnets.

Probiotic and prebiotic interventions for non-alcoholic fatty liver disease: a systematic review and network meta-analysis

Many studies have associated altered intestinal bacterial communities and non-alcoholic fatty liver disease, but the putative effects are inconclusive. The purpose of this network meta-analysis (NMA) was to evaluate the effects of probiotics, prebiotics, and synbiotics on non-alcoholic fatty liver disease through randomised intervention trials. Literature searches were performed until March 2020. For each outcome, a random NMA was performed, the surface under the cumulative ranking curve (SUCRA) was determined. A total of 22 randomised trials comparing prebiotic, probiotic, and synbiotic treatments included 1301 participants. Considering all seven results (aspartate aminotransferase, alanine aminotransferase, body mass index, weight, total cholesterol, high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol) together, the highest SUCRA values are probiotics (94%), synbiotics (61%) and prebiotics (56%), respectively. NMA results provide evidence that probiotics, prebiotics, and synbiotics can alleviate non-alcoholic fatty liver disease. However, due to the lack of high-quality randomised trials, this research also has some limitations.

Investigation of the importance of different factors of flood inundation modeling applied in urbanized area with variance-based global sensitivity analysis

Flood modeling provides useful information to support flood risk assessment and management and reduce flood impacts in urbanized area. The accuracy of urban flood simulation results is highly dependent on the quality of input data for which the appropriate values are generally difficult to determine for complex urbanized environment and from which various uncertainties are induced into the modeling procedure. In this study, variance-based global sensitivity analysis is applied for the hydrodynamic modeling of urban flood to explore the relative importance of the factors of interest as model inputs and their contributions to the final results of the numerical model for different outputs. The factors include the spatial resolution, the forcing condition and the characteristics of the underlying urbanized surface. The global sensitivity analysis results are examined in both spatially lumped and distributed perspective. Findings indicate that importance of the input factors varies with regard to different model output and the influence of the spatial resolution is more tightly related to the flood flow movements whereas that of the rainfall inputs is more relevant to the flood water volume. Spatial variability in the influence of the input factors is revealed to be hidden by the spatially lumped results and the importance of the factors describing the underlying urban surface is found to be largely dependent on the location of the analyzed model output associated with the land-use type. Improved understanding of sensitivity of hydrodynamic modeling of urban floods may help the modelers to decide which input factors to prioritize on according to which model outputs are assessed and where they are assessed.

Efficacy of repetitive transcranial magnetic stimulation for post-stroke depression: a systematic review and meta-analysis of randomized clinical trials

We aimed to conduct a meta-analysis to evaluate the efficacy of repetitive transcranial magnetic stimulation (rTMS) in patients with post-stroke depression (PSD). Six relevant electronic databases (PubMed, CENTRAL, Embase, Web of Science, CINAHL, and PsycINFO) were searched. Randomized controlled trials (RCTs) that compared rTMS with control condition for PSD were included. The mean change in depression symptom scores was defined as the primary efficacy outcome. Secondary outcomes included the remission rate of depression, stroke recovery, and cognitive function recovery. In total, 7 RCTs with 351 participants were included. At post-treatment, rTMS was significantly more effective than the control condition, with a standardized mean difference (SMD) of -1.15 (95%CI: -1.62 to -0.69; P<0.001, I2=71%) and remission with an odds ratio (OR) of 3.46 (95%CI: 1.68 to 7.12; P<0.001; I2=11%). As for stroke recovery, rTMS was also better than the control condition (SMD=-0.67, 95%CI: -1.02 to -0.32; P<0.001). However, no significant difference was found for cognitive function recovery between the two groups (SMD=4.07, 95%CI: -1.41 to 9.55; P=0.15). To explore the potential moderators for the primary outcome, a series of subgroup and sensitivity analyses were performed. The results implied that rTMS may be more effective in Asian samples than in North American samples (P=0.03). In conclusion, from the current evidence in this study, rTMS could be an effective treatment for patients with PSD. Further clinical studies with larger sample sizes and clearer subgroup definitions are needed to confirm these outcomes.

Spin and valence isomerism in cyanide-bridged {FeMII} (M = Fe and Co) clusters

Two cyanide-bridged V-shaped isostructural trinuclear complexes [{(Tp*)FeIII(CN)3}2MII(bztpen)]·Sol (M = Fe, Sol = CH3OH·3H2O, 1; M = Co, Sol = 2CH3OH·2H2O, 2; bztpen = N-benzyl-N,N',N'-tris(2-methylpyridyl)ethylenediamine; Tp* = hydrotris(3,5-dimethylpyrazolyl)borate) were synthesized and characterized. The bztpen ligand serves as a tetradentate capping ligand around the inner metal ion, leaving one pyridyl group intact. Complex 1 exhibits a spin crossover (SCO) behavior between the {FeIIILSFeIIHSFeIIILS} and {FeIIILSFeIILSFeIIILS} spin isomers, while 2 shows both thermally- and photo-induced electron-transfer coupled spin transition (ETCST) property between the {FeIIILSCoIIHSFeIIILS} and {FeIIILSCoIIILSFeIILS} valence isomers. The total entropy changes for 1 and 2 between their corresponding two electronic states were found to be very close with the values of 87.46 and 84.49 J mol-1 K-1, respectively, indicating the comparable thermal energy barriers necessary for either an SCO or ETCST event for such a given system. Furthermore, both complexes undergo desolvation-induced irreversible and sharp magnetic change at high temperatures.

Applications of microbial co-cultures in polyketides production

Polyketides are a large group of natural biomolecules that are normally produced by bacteria, fungi and plants. These molecules have clinical importance due to their anti-cancer, anti-microbial, anti-oxidant and anti-inflammatory properties. Polyketides are biosynthesized from units of acyl-CoA by different polyketide synthases (PKSs), which display wide diversity of functional domains and mechanisms of action between fungi and bacteria. Co-culture of different micro-organisms can produce novel products distinctive from those produced during single cultures. This study compared the new polyketides produced in such co-culture systems and discusses aspects of the cultivation systems, product structures and identification techniques. Current results indicate that the formation of new polyketides may be the result of activation of previously silent PKSs genes induced during co-culture. This review indicated a potential way to produce pure therapeutic polyketides by microbial fermentation and a potential way to develop functional foods and agricultural products using co-co-culture of different micro-organisms. It also pointed out a new perspective for studies on the process of functional foods, especially those involving multiple micro-organisms.

Tuning Magnetic Anisotropy in a Class of Co(II) Bis(hexafluoroacetylacetonate) Complexes

Tuning the magnetic anisotropy of metal ions remains highly interesting in the design of improved single-molecule magnets (SMMs). We herein report synthetic, structural, magnetic, and computational studies of four mononuclear Co^II complexes, namely [Co(hfac)₂ (MeCN)₂ ] (1), [Co(hfac)₂ (Spy)₂ ] (2), [Co(hfac)₂ (MBIm)₂ ] (3), and [Co(hfac)₂ (DMF)₂ ] (4) (MeCN=acetonitrile, hfac=hexafluoroacetylacetone, Spy=4-styrylpyridine, MbIm=5,6-dimethylbenzimidazole, DMF=N,N-dimethylformamide), with distorted octahedral geometry constructed from hexafluoroacetylacetone (hfac) and various axial ligands. By a building block approach, complexes 2-4 were synthesized by recrystallization of the starting material of 1 from various ligands containing solution. Magnetic and theoretical studies reveal that 1-4 possess large positive D values and relative small E parameters, indicating easy-plane magnetic anisotropy with significant rhombic anisotropy in 1-4. Dynamic alternative current (ac) magnetic susceptibility measurements indicate that these complexes exhibit slow magnetic relaxation under external fields, suggesting field-induced single-ion magnets (SIMs) of 1-4. These results provide a promising platform to achieve fine tuning of magnetic anisotropy through varying the axial ligands based on Co(II) bis(hexafluoroacetylacetonate) complexes.

Field-induced slow magnetic relaxation in two interpenetrated cobalt(ii) metal–organic framework isomers

Two interpenetrated cobalt(ii) metal–organic framework (MOF) isomers were successfully synthesized and magnetically characterized. These compounds are the first example of MOF isomers showing field-induced single-ion magnet behavior.

Two Four-Coordinate and Seven-Coordinate CoII Complexes Based on the Bidentate Ligand 1, 8-Naphthyridine Showing Slow Magnetic Relaxation Behavior

For a long time, the cobalt(II) complex ([Co(napy)₄ ](ClO₄ )₂ ) (napy=1, 8-naphthyridine) has been considered as an eight-coordinate complex without any structural proof. After careful considerations, two complexes [Co(napy)₂ Cl₂ ] (1) and [Co(napy)₄ ](ClO₄ )₂ (2) based on the bidentate ligand napy were synthesized and structurally characterized. X-ray single-crystal structural determination showed that the cobalt(II) center in [Co(napy)₂ Cl₂ ] (1) is four-coordinate with a tetrahedral geometry (T_d ), while [Co(napy)₄ ](ClO₄ )₂ (2) is seven-coordinate rather than eight-coordinate with a capped trigonal prism geometry (C_2v ). Direct-current (dc) magnetic data revealed that complexes 1 and 2 possess positive zero-field splitting (ZFS) parameters of 11.08 and 25.30 cm^-1 , respectively, with easy-plane magnetic anisotropy. Alternating current(ac) susceptibility measurements revealed that both complexes showed slow magnetic relaxation behaviour. Theoretical calculations demonstrated that the presence of easy-plane magnetic anisotropy (D>0) for complexes 1 and 2 is in agreement with the experimental data. Furthermore, these results pave the way to obtain four-coordinate and seven-coordinate cobalt(II) single-ion magnets (SIMs) by using a bidentate ligand.