COMP promotes pancreatic fibrosis by activating pancreatic stellate cells through CD36-ERK/AKT signaling pathways.

BACKGROUND: Pancreatic fibrosis is one of the most important pathological features of chronic pancreatitis (CP) and pancreatic stellate cells (PSCs) are the key cells of fibrosis. As an extracellular matrix (ECM) glycoprotein, cartilage oligomeric matrix protein (COMP) is critical for collagen assembly and ECM stability and recent studies showed that COMP exert promoting fibrosis effect in the skin, lungs and liver. However, the role of COMP in activation of PSCs and pancreatic fibrosis remain unclear. We aimed to investigate the role and specific mechanisms of COMP in regulating the profibrotic phenotype of PSCs and pancreatic fibrosis. METHODS: ELISA method was used to determine serum COMP in patients with CP. Mice model of CP was established by repeated intraperitoneal injection of cerulein and pancreatic fibrosis was evaluated by Hematoxylin-Eosin staining (H&E) and Sirius red staining. Immunohistochemical staining was used to detect the expression changes of COMP and fibrosis marker such as α-SMA and Fibronectin in pancreatic tissue of mice. Cell Counting Kit-8, Wound Healing and Transwell assessed the proliferation and migration of human pancreatic stellate cells (HPSCs). Western blotting, qRT-PCR and immunofluorescence staining were performed to detect the expression of fibrosis marker, AKT and MAPK family proteins in HPSCs. RNA-seq omics analysis as well as small interfering RNA of COMP, recombinant human COMP (rCOMP), MEK inhibitors and PI3K inhibitors were used to study the effect and mechanism of COMP on activation of HPSCs. RESULTS: ELISA showed that the expression of COMP significantly increased in the serum of CP patients. H&E and Sirius red staining analysis showed that there was a large amount of collagen deposition in the mice in the CP model group and high expression of COMP, α-SMA, Fibronectin and Vimentin were observed in fibrotic tissues. TGF-ß1 stimulates the activation of HPSCs and increases the expression of COMP. Knockdown of COMP inhibited proliferation and migration of HPSCs. Further, RNA-seq omics analysis and validation experiments in vitro showed that rCOMP could significantly promote the proliferation and activation of HPSCs, which may be due to promoting the phosphorylation of ERK and AKT through membrane protein receptor CD36. rCOMP simultaneously increased the expression of α-SMA, Fibronectin and Collagen I in HPSCs. CONCLUSION: In conclusion, this study showed that COMP was up-regulated in CP fibrotic tissues and COMP induced the activation, proliferation and migration of PSCs through the CD36-ERK/AKT signaling pathway. COMP may be a potential therapeutic candidate for the treatment of CP. Interfering with the expression of COMP or the communication between COMP and CD36 on PSCs may be the next direction for therapeutic research.

Designing the multimedia system for improving promotion of college students' psychological capital.

Given the rising psychological challenges encountered by university students, there is an imperative to address the pressing need for enhancing their psychological capital. This study is to design an innovative multimedia system that seeks to offer comprehensive psychological support and promotion mechanisms for university students. This is achieved through the integrated use of various media forms. Multimedia system group counseling was employed to assess and enhance the psychological capital of college students. This study comprises two main components: first, an analysis of the application of multimedia technology in education, and second, an empirical investigation into college students' psychological capital through a questionnaire survey. The findings reveal that the introduction of group counseling via a multimedia system significantly enhances the psychological capital of college students. This improvement in psychological capital positively impacts the well-being and mental states of students and contributes novel ideas to mental health education for college students. The effectiveness of the group counseling intervention scheme within the multimedia system is evident, suggesting its potential for widespread adoption. The utilization of multimedia systems in educational settings emphasizes the importance of positive psychology for students and contributes to cultivating a positive and healthy psychological state. This study serves as a valuable reference for enhancing the psychological capital of college students, focusing on aspects such as independent thinking, decision-making, and execution.

Overexpression of mitogen-activated protein kinase phosphatase-1 in endothelial cells reduces blood-brain barrier injury in a mouse model of ischemic stroke.

Ischemic stroke can cause blood-brain barrier (BBB) injury, which worsens brain damage induced by stroke. Abnormal expression of tight junction proteins in endothelial cells (ECs) can increase intracellular space and BBB leakage. Selective inhibition of mitogen-activated protein kinase, the negative regulatory substrate of mitogen-activated protein kinase phosphatase (MKP)-1, improves tight junction protein function in ECs, and genetic deletion of MKP-1 aggravates ischemic brain injury. However, whether the latter affects BBB integrity, and the cell type-specific mechanism underlying this process, remain unclear. In this study, we established an adult male mouse model of ischemic stroke by occluding the middle cerebral artery for 60 minutes and overexpressed MKP-1 in ECs on the injured side via lentiviral transfection before stroke. We found that overexpression of MKP-1 in ECs reduced infarct volume, reduced the level of inflammatory factors interleukin-1ß, interleukin-6, and chemokine C-C motif ligand-2, inhibited vascular injury, and promoted the recovery of sensorimotor and memory/cognitive function. Overexpression of MKP-1 in ECs also inhibited the activation of cerebral ischemia-induced extracellular signal-regulated kinase (ERK) 1/2 and the downregulation of occludin expression. Finally, to investigate the mechanism by which MKP-1 exerted these functions in ECs, we established an ischemic stroke model in vitro by depriving the primary endothelial cell of oxygen and glucose, and pharmacologically inhibited the activity of MKP-1 and ERK1/2. Our findings suggest that MKP-1 inhibition aggravates oxygen and glucose deprivation-induced cell death, cell monolayer leakage, and downregulation of occludin expression, and that inhibiting ERK1/2 can reverse these effects. In addition, co-inhibition of MKP-1 and ERK1/2 exhibited similar effects to inhibition of ERK1/2. These findings suggest that overexpression of MKP-1 in ECs can prevent ischemia-induced occludin downregulation and cell death via deactivating ERK1/2, thereby protecting the integrity of BBB, alleviating brain injury, and improving post-stroke prognosis.

Benign incidental cardiac findings in chest and cardiac CT imaging.

With the continuous expansion of the disease scope of chest CT and cardiac CT, the number of these CT examinations has increased rapidly. In addition to their common indications, many incidental cardiac findings can be observed when carefully evaluating the coronary arteries, valves, pericardium, ventricles, and large vessels. These findings may have clinical significance or risk of complications, but they are sometimes overlooked or may not be described in the final reports. Although most of the incidental findings are benign, timely detection and treatment can improve the management of chronic diseases or reduce the possibility of severe complications. In this review, we summarized the imaging findings, incidence rate, and clinical relevance of some benign cardiac findings such as coronary artery calcification, aortic and mitral valve calcification, aortic calcification, cardiac thrombus, myocardial bridge, aortic dilation, cardiac myxoma, pericardial cyst, and coronary artery fistula. Reporting incidental cardiac findings will help reduce the risk of severe complications or disease deterioration and contribute to the recovery of patients.

Puerarin Ameliorates Caerulein-Induced Chronic Pancreatitis via Inhibition of MAPK Signaling Pathway.

Pancreatic fibrosis is one of the most important pathological features of chronic pancreatitis (CP), and pancreatic stellate cells (PSCs) are considered to be the key cells. Puerarin is the most important flavonoid active component in Chinese herb Radix Puerariae, and it exhibited anti-fibrotic effect in various fibrous diseases recently. However, the impact and molecular mechanism of puerarin on CP and pancreatic fibrosis remain unknown. This study systematically investigated the effect of puerarin on CP and pancreatic fibrosis in vivo and in vitro. H&E staining, Sirius Red staining, qRT-PCR and Western blotting analysis of fibrosis and inflammation related genes of pancreatic tissues showed that puerarin notably ameliorated pancreatic atrophy, inflammation and fibrosis in a model of caerulein-induced murine CP. Western blotting analysis of pancreatic tissues showed the phosphorylation level of MAPK family proteins (JNK1/2, ERK1/2 and p38 MAPK) significantly increased after modeling of cerulein, while puerarin could inhibit their phosphorylation levels to a certain extent. We found that puerarin exerted a marked inhibition on the proliferation, migration and activation of PSCs, determined by CCK-8 assay, transwell migration assay, scratch wound-healing assay and expression levels of α-SMA, Fibronectin, Col1α1 and GFAP. Western blotting result demonstrated that puerarin markedly inhibited the phosphorylation of MAPK family proteins (JNK1/2, ERK1/2 and p38 MAPK) of PSCs in a dose-dependent manner whether or not stimulated by platelet-activating factor. In conclusion, the present study showed that puerarin could be a potential therapeutic candidate in the treatment of CP, and the MAPK pathway might be its important target.

Co nanoparticles supported on three-dimensionally N-doped holey graphene aerogels for electrocatalytic oxygen reduction.

The reactive and stable catalysts for the oxygen reduction reaction are highly desirable for low temperature fuel cells. The commercial oxygen reduction reaction electrocatalysts generally reply on noble metal based nanomaterials, which suffer from inherent cost and selectivity issues. At present, it still remains challenge for designing efficient non-noble metal-based oxygen reduction reaction electrocatalysts. Herein, we successfully synthesize Co nanoparticles supported on three-dimensionally N-doped holey graphene aerogels hybrids by the high-temperature calcination of the graphene aerogels-polyallylamine-CoII hybrids. The component optimized hybrids show the excellent electrocatalytic activity for oxygen reduction reaction in alkaline media, which is comparable to commercial Pt/C electrocatalyst. Meanwhile, the hybrids also show eminent tolerance for CO and methanol, attributing to their excellent oxygen reduction reaction selectivity. The three-dimensionally interconnected structure of graphene aerogels, N-doping, uniform dispersion and high crystallinity of Co nanoparticles, and holey structure of graphene contribute to the striking oxygen reduction reaction activity of hybrids.

Ultrathin Rh nanosheets as a highly efficient bifunctional electrocatalyst for isopropanol-assisted overall water splitting.

In this work, we synthesized ultrathin Rh nanosheets (Rh-NSs) with atomic thickness, which revealed excellent activity for the hydrogen evolution reaction (HER) and super activity and extraordinary selectivity for the isopropanol oxidation reaction (IOR) in alkaline medium. When using Rh-NSs as a bifunctional electrocatalyst for water electrolysis in the presence of isopropanol, a voltage of only 0.4 V was required for H2 production, accompanied by the production of valuable acetone at the anode.

Bimetallic Platinum-Rhodium Alloy Nanodendrites as Highly Active Electrocatalyst for the Ethanol Oxidation Reaction.

Rationally designing and manipulating composition and morphology of precious metal-based bimetallic nanostructures can markedly enhance their electrocatalytic performance, including selectivity, activity, and durability. We herein report the synthesis of bimetallic PtRh alloy nanodendrites (ANDs) with tunable composition by a facile complex-reduction synthetic method under hydrothermal conditions. The structural/morphologic features, formation mechanism, and electrocatalytic performance of PtRh ANDs are investigated thoroughly by various physical characterization and electrochemical methods. The preformed Rh crystal nuclei effectively catalyze the reduction of Pt2+ precursor, resulting in PtRh alloy generation due to the catalytic growth and atoms interdiffusion process. The Pt atoms deposition distinctly interferes in Rh atoms deposition on Rh crystal nuclei, resulting in dendritic morphology of PtRh ANDs. For the ethanol oxidation reaction (EOR), PtRh ANDs display the chemical composition and solution pH co-dependent electrocatalytic activity. Because of the alloy effect and particular morphologic feature, Pt1Rh1 ANDs with optimized composition exhibit better reactivity and stability for the EOR than commercial Pt nanocrystals electrocatalyst.

Bicarbazole-based redox-active covalent organic frameworks for ultrahigh-performance energy storage.

A highly redox-active building block, bicarbazole, is developed as a monomer for designing crystalline porous covalent organic frameworks and is successfully integrated to the vertices of microporous tetragonal frameworks, leading to densely aligned redox-active arrays. The frameworks with large porosity and high accessibility of the redox-active sites exhibit synergistic structural effects and ultrahigh-performance energy storage.

Control Synthesis of Tubular Hyper-Cross-Linked Polymers for Highly Porous Carbon Nanotubes.

Porous carbon nanotubes (PCNTs) have attracted considerable attention due to their large specific surface areas and unique one-dimensional (1D) structures. However, most of the reported synthetic strategies for PCNTs are complex and expensive. Herein, we present a self-templated, surfactant-free strategy for the synthesis of high-quality PCNTs with high surface area by direct carbonization of 1D hyper-cross-linked polymer nanotubes. The precursors of the 1D hyper-cross-linked polymer nanotubes were synthesized by FeCl3 catalyzed Friedel-Crafts alkylation of aromatic hydrocarbons with formaldehyde dimethyl acetal. It was found that the monomer concentration and mechanical agitation play crucial roles in the formation of the 1D tubular hyper-cross-linked polymer precursor. The tube size of the resulting PCNTs could be finely controlled by the aromatic monomers with different molecular sizes. The excellent electrochemical performances of the supercapacitors fabricated from the PCNTs demonstrate that these PCNTs are promising for the electrode materials of high-performance supercapacitors. This work highlights that the facile synthetic strategy for PCNTs would open up new avenues of porous carbon nanotube materials with promising applications.

Ultrathin Rhodium Oxide Nanosheet Nanoassemblies: Synthesis, Morphological Stability, and Electrocatalytic Application.

Inspired by graphene, ultrathin two-dimensional nanomaterials with atomic thickness have attracted more and more attention because of their unique physicochemical properties and electronic structure. In this work, the atomically thick ultrathin Rh2O3 nanosheet nanoassemblies (Rh2O3-NSNSs) were obtained by oxidizing the atomically thick ultrathin Rh nanosheet nanoassemblies with HClO. For the first time, Rh-based nanostructures were used as the oxygen evolution reaction (OER) electrocatalyst in an alkaline medium. Surprisingly, the as-prepared Rh2O3-NSNSs displayed extremely improved catalytic activity and durability for the OER compared with those of the commercial Ir/C catalyst and most recently reported Ir-based electrocatalysts. The result indicated Rh-based nanostructures that have great promise to become a potential candidate for efficient OER electrocatalyst because of the similarity of Rh and Ir prices. These experimental results demonstrated the reasonable morphological control of Rh2O3 nanostructures could significantly improve their catalytic activity and durability during heterogeneous catalysis.

Enhancing Efficiency and Stability of Perovskite Solar Cells through Nb-Doping of TiO2 at Low Temperature.

The conduction band energy, conductivity, mobility, and electronic trap states of electron transport layer (ETL) are very important to the efficiency and stability of a planar perovskite solar cell (PSC). However, as the most widely used ETL, TiO2 often needs to be prepared under high temperature and has unfavorable electrical properties such as low conductivity and high electronic trap states. Modifications such as elemental doping are effective methods for improving the electrical properties of TiO2 and the performance of PSCs. In this study, Nb-doped TiO2 films are prepared by a facile one-port chemical bath process at low temperature (70 °C) and applied as a high quality ETL for planar PSCs. Compared with pure TiO2, the Nb-doped TiO2 is more efficient for photogenerated electron injection and extraction, showing higher conductivity, higher mobility, and lower trap-state density. A PSC with 1% Nb-doped TiO2 yielded a power conversion efficiency of more than 19%, with about 90% of its initial efficiency remaining after storing for 1200 h in air or annealing at 80 °C for 20 h in a glovebox.

Hydrothermal Synthesis and Catalytic Application of Ultrathin Rhodium Nanosheet Nanoassemblies.

Ultrathin noble metal nanosheets with atomic thickness exhibit abnormal electronic, surfacial, and photonic properties due to the unique two-dimensional (2D) confinement effect, which have attracted intensive research attention in catalysis/electrocatalysis. In this work, the well-defined ultrathin Rh nanosheet nanoassemblies with dendritic morphology are synthesized by a facile hydrothermal method with assistance of poly(allylamine hydrochloride) (PAH), where PAH effectively acts as the complexant and shape-directing agent. Transmission electron microscopy and atomic force microscopy images reveal the thickness of 2D Rh nanosheet with (111) planes is only ca. 0.8-1.1 nm. Nitrogen adsorption-desorption measurement displays the specific surface area of the as-prepared ultrathin Rh nanosheet nanoassemblies is 139.4 m2 g-1, which is much bigger than that of homemade Rh black (19.8 m2 g-1). Detailed catalytic investigations display the as-prepared ultrathin Rh nanosheet nanoassemblies have nearly 20.4-fold enhancement in mass-activity for the hydrolysis of ammonia borane as compared with homemade Rh black.

One-Pot Fabrication of Hollow and Porous Pd-Cu Alloy Nanospheres and Their Remarkably Improved Catalytic Performance for Hexavalent Chromium Reduction.

Noble metal nanostructures (NMNSs) play a crucial role in many heterogeneous catalytic reactions. Hollow and porous NMNSs possess generally prominent advantages over their solid counterparts due to their unordinary structural features. In this work, we describe a facial one-pot synthesis of hollow and porous Pd-Cu alloy nanospheres (Pd-Cu HPANSs) through a polyethylenimine (PEI)-assisted oxidation-dissolution mechanism. The strong coordination interaction between CuII and PEI facilitates the oxidation-dissolution of the Cu2O nanospheres template under air conditions, which is responsible for the generation of the Pd-Cu alloy and the convenient removal of the Cu2O nanospheres template at room temperature. Compared to the commercial Pd black, the Pd-Cu HPANSs show remarkably improved catalytic activity for the reduction of K2Cr2O7 by HCOOH at room temperature, attributing to the enhanced catalytic activity of the Pd-Cu HPANSs for the dehydrogenation decomposition of HCOOH.

A computational study on the complexation of Np(V) with N,N,N',N'-tetramethyl-3-oxa-glutaramide (TMOGA) and its carboxylate analogs.

Density functional theory has been used to study the geometries and relative stabilities of the complexes of NpO2(+) with the title compounds (L), including TMOGA, deprotonated N,N'-dimethyl-3-oxa-glutaramic acid (DMOGA) and their deprotonated oxydiacetic analog (ODA). Our calculations suggest that the complexes where the ligands appear as tridentate chelators are more stable than as bidentate ones, and the substitution of the amide group by carboxylate favors the formation of the complexes. Thermodynamically the 1 : 2 complex (Np-L2) is more favorable than the 1 : 1 complex (Np-L) in the cases of TMOGA and DMOGA, but not for the ODA anion. Taking into account the solvation effect of water, the 1 : 2 complex is more favorable than the 1 : 1 complex for all of the three ligands, though the reaction enthalpy decreases compared to that in the gas phase, and the formation of Np-(TMOGA)2 from Np-TMOGA is roughly a thermal neutral process. The strength of the Np=O bond is weakened upon the coordination of ligands to Np(V) and the increase of the negative charge on the ligand (-1e for deprotonated DMOGA and -2e for deprotonated ODA). The Quantum Theory of Atoms-in-Molecules (QTAIM) was used here to analyze the bonding mode of NpO2(+)-Lx (x = 1, 2) and to compare the bond order data.

Solvothermal route to synthesize well-dispersed YBO3:Eu nanocrystals.

Well-dispersed YBO(3):Eu nanocrystals have been fabricated by a solvothermal method. The size and morphology of the products are controlled successfully via adjusting the reaction conditions. The prepared YBO(3):Eu phosphors were characterized by powder X-ray diffraction, transmission electron microscopy, and other techniques. The luminescence mechanism and the size dependence of their fluorescence properties are also explained.