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1.
JAMA Surg ; 2024 May 01.
Article En | MEDLINE | ID: mdl-38691353

Importance: Splenic hilar lymphadenectomy has been recommended for locally advanced proximal gastric cancer (APGC) involving the greater curvature. However, it is unclear whether laparoscopic spleen-preserving splenic hilar lymphadenectomy (LSPSHL) is associated with a long-term survival benefit for APGC without greater curvature invasion. Objective: To present the 5-year follow-up data from a randomized clinical trial that compared laparoscopic total gastrectomy (D2 group) with D2 plus LSPSHL (D2 + No. 10 group) among patients with resectable APGC. Design, Setting, and Participants: This is a post hoc secondary analysis of a randomized clinical trial that enrolled 536 patients with potentially resectable APGC (cT2-4a, N0 or N+, and M0) without greater curvature invasion from January 5, 2015, to October 10, 2018. All patients were tracked for at least 5 years. The final follow-up was on October 30, 2023. Interventions: Patients were randomly assigned in a 1:1 ratio to the D2 + No. 10 or D2 groups. Main Outcomes and Measures: The 5-year disease-free survival (DFS) and overall survival (OS) rates were measured. Recurrence patterns and causes of death were compared. Results: A total of 526 patients (392 men [74.5%]; mean [SD] age, 60.6 [9.6] years) were included in the modified intent-to-treat analysis, with 263 patients in each group. The 5-year DFS rate was 63.9% (95% CI, 58.1%-69.7%) for the D2 + No. 10 group and 55.1% (95% CI, 49.1%-61.1%) for the D2 group (log-rank P = .04). A statistically significant difference was observed in the 5-year OS between the D2 + No. 10 group and the D2 group (66.2% [95% CI, 60.4%-71.9%] vs 57.4% [95% CI, 51.4%-63.4%]; log-rank P = .03). The No. 10 lymph node exhibited a therapeutic value index (TVI) of 6.5, surpassing that of Nos. 8a (TVI, 3.0), 11 (TVI, 5.8), and 12a (TVI, 0.8). A total of 86 patients in the D2 + No. 10 group (cumulative incidence, 32.7%) and 111 patients in the D2 group (cumulative incidence, 42.2%) experienced recurrence (hazard ratio, 0.72; 95% CI, 0.54-0.95; P = .02). The multivariable competing risk regression model demonstrated that D2 + No. 10 remained an independent protective factor for a lower 5-year cumulative recurrence rate after surgery (hazard ratio, 0.75; 95% CI, 0.56-1.00; P = .05). There was a significant difference in the 5-year cumulative recurrence rate at the No. 10 lymph node area between the 2 groups (D2 + No. 10 group vs D2 group: 0% vs 2.3% [n = 6]; P = .01). Conclusions: This post hoc secondary analysis of a randomized clinical trial found that laparoscopic total gastrectomy with LSPSHL can improve the prognosis and reduce recurrence for APGC without greater curvature invasion. Future multicenter studies are warranted to validate these findings. Trial Registration: ClinicalTrials.gov Identifier: NCT02333721.

2.
J Orthop Translat ; 45: 226-235, 2024 Mar.
Article En | MEDLINE | ID: mdl-38596341

Objectives: To investigate the potential role of Ribosomal protein L35 (RPL35) in regulating chondrocyte catabolic metabolism and to examine whether osteoarthritis (OA) progression can be delayed by overexpressing RPL35 in a mouse compression loading model. Methods: RNA sequencing analysis was performed on chondrocytes treated with or without 20 % elongation strain loading for 24 h. Experimental OA in mice was induced by destabilization of the medial meniscus and compression loading. Mice were randomly assigned to a sham group, an intra-articular adenovirus-mediated overexpression of the negative group, and an intra-articular adenovirus-mediated overexpression of the RPL35 operated group. The Osteoarthritis Research Society International score was used to evaluate cartilage degeneration. Immunostaining and western blot analyses were conducted to detect relative protein levels. Primary mouse chondrocytes were treated with 20 % elongation strain loading for 24 h to investigate the role of RPL35 in modulating chondrocyte catabolic metabolism and regulating cellular senescence in chondrocytes. Results: The protein expression of RPL35 in mouse chondrocytes was significantly reduced when excessive mechanical loading was applied, while elevated protein levels of RPL35 protected articular chondrocytes from degeneration. In addition, the RPL35 knockdown alone induced chondrocyte senescence, decreased the expression of anabolic markers, and increased the expression of catabolic markers in vitro in part through the hedgehog (Hh) pathway. Conclusions: These findings demonstrated a functional pathway important for OA development and identified intra-articular injection of RPL35 as a potential therapy for OA prevention and treatment. The translational potential of this article: It is necessary to develop new targeted drugs for OA due to the limitations of conventional pharmacotherapy. Our study explores and demonstrates the protective effect of RPL35 against excessive mechanical stress in OA models in vivo and in vitro in animals. These findings might provide novel insights into OA pathogenesis and show its translational potential for OA therapy.

3.
Small ; 19(43): e2302380, 2023 Oct.
Article En | MEDLINE | ID: mdl-37357155

There are enormous yet largely underexplored exotic phenomena and properties emerging from interfaces constructed by diverse types of components that may differ in composition, shape, or crystal structure. It remains poorly understood the unique properties a coherent interface between crystalline and amorphous materials may evoke, and there lacks a general strategy to fabricate such interfaces. It is demonstrated that by topotactic partial oxidation heterostructures composed of coherently registered crystalline and amorphous materials can be constructed. As a proof-of-concept study, heterostructures consisting of crystalline P3 N5 and amorphous P3 N5 Ox can be synthesized by creating amorphous P3 N5 Ox from crystalline P3 N5 without interrupting the covalent bonding across the coherent interface. The heterostructure is dictated by nanometer-sized short-range-ordered P3 N5 domains enclosed by amorphous P3 N5 Ox matrix, which entails simultaneously fast charge transfer across the interface and bicomponent synergistic effect in catalysis. Such a P3 N5 /P3 N5 Ox heterostructure attains an optimal adsorption energy for *OOH intermediates and exhibits superior electrocatalytic performance toward H2 O2 production by adopting a selectivity of 96.68% at 0.4 VRHE and a production rate of 321.5 mmol h-1 gcatalyst -1 at -0.3 VRHE . The current study provides new insights into the synthetic strategy, chemical structure, and catalytic property of a sub-nanometer coherent interface formed between crystalline and amorphous materials.

4.
Elife ; 122023 05 05.
Article En | MEDLINE | ID: mdl-37144868

Obesity has always been considered a significant risk factor in osteoarthritis (OA) progression, but the underlying mechanism of obesity-related inflammation in OA synovitis remains unclear. The present study found that synovial macrophages infiltrated and polarized in the obesity microenvironment and identified the essential role of M1 macrophages in impaired macrophage efferocytosis using pathology analysis of obesity-associated OA. The present study revealed that obese OA patients and Apoe-/- mice showed a more pronounced synovitis and enhanced macrophage infiltration in synovial tissue, accompanied by dominant M1 macrophage polarization. Obese OA mice had a more severe cartilage destruction and increased levels of synovial apoptotic cells (ACs) than OA mice in the control group. Enhanced M1-polarized macrophages in obese synovium decreased growth arrest-specific 6 (GAS6) secretion, resulting in impaired macrophage efferocytosis in synovial ACs. Intracellular contents released by accumulated ACs further triggered an immune response and lead to a release of inflammatory factors, such as TNF-α, IL-1ß, and IL-6, which induce chondrocyte homeostasis dysfunction in obese OA patients. Intra-articular injection of GAS6 restored the phagocytic capacity of macrophages, reduced the accumulation of local ACs, and decreased the levels of TUNEL and Caspase-3 positive cells, preserving cartilage thickness and preventing the progression of obesity-associated OA. Therefore, targeting macrophage-associated efferocytosis or intra-articular injection of GAS6 is a potential therapeutic strategy for obesity-associated OA.


Osteoarthritis , Synovitis , Animals , Mice , Macrophages , Obesity/complications , Obesity/pathology , Osteoarthritis/drug therapy , Synovial Membrane/pathology , Synovitis/complications , Synovitis/pathology , Humans
5.
Nat Commun ; 14(1): 661, 2023 Feb 07.
Article En | MEDLINE | ID: mdl-36750563

2D metallene nanomaterials have spurred considerable attention in heterogeneous catalysis by virtue of sufficient unsaturated metal atoms, high specific surface area and surface strain. Nevertheless, the strong metallic bonding in nanoparticles aggravates the difficulty in the controllable regulation of the geometry of metallenes. Here we propose an efficient galvanic replacement strategy to construct Pd metallenes loaded on Nb2C MXenes at room temperature, which is triggered by strong metal-support interaction based on MD simulations. The Pd metallenes feature a chair structure of six-membered ring with the coordination number of Pd as low as 3. Coverage-dependent kinetic analysis based on first-principles calculations reveals that the tripodal Pd metallenes promote the diffusion of alkene and inhibit its overhydrogenation. As a consequence, Pd/Nb2C delivers an outstanding turnover frequency of 10372 h-1 and a high selectivity of 96% at 25 oC in the semihydrogenation of alkynes without compromising the stability. This strategy is general and scalable considering the plentiful members of the MXene family, which can set a foundation for the design of novel supported-metallene catalysts for demanding transformations.

6.
Dalton Trans ; 52(2): 461-468, 2023 Jan 03.
Article En | MEDLINE | ID: mdl-36525267

The catalytic conversion of CO or CO/CO2 mixtures to higher alcohols (HAs) using hydrogenation reactions remains challenging in C1 chemistry and also one of the most promising reactions for the utilization of non-petroleum resources. Here, the experiment and characterization tests of CuCoMn/Al2O3 show that copper is much more dispersed on γ-Al2O3 than cobalt, and the interaction between cobalt and Mn metals is stronger. And, mixed cobalt-manganese oxides are formed in the calcined catalyst, promoting the formation of higher alcohols. Under the optimum conditions, the catalyst demonstrated a total alcohol selectivity of 44.6%, and the fraction of higher alcohols reached up to 85.3% among the total alcohol products, which is superior to the classical modified CuCo-based catalysts. And in the gas mixture reaction with a CO : CO2 ratio of 8 : 2, the conversion rate of the catalyst to CO and CO2 reached 34.8% and 27.3%, respectively, and the selectivity (C1+ slate 1-alcohol) was 53.2%.

7.
ACS Omega ; 7(47): 42890-42900, 2022 Nov 29.
Article En | MEDLINE | ID: mdl-36467943

The production of aromatic hydrocarbons from the waste tire pyrolysis attracts more and more attention because of its tremendous potential. Based on styrene-butadiene rubber (SBR), which is the main rubber in the waste passenger car tires, this work studies the temperature influence on primary pyrolysis product distribution by experimental techniques (Py-GC/MS, TG-MS), and then, the formation mechanism of monocyclic aromatic hydrocarbons (MAHs) observed in the experiment was analyzed by first-principles calculations. The experimental results show that the MAHs during the pyrolysis mainly include styrene, toluene, and xylene, and subsequent calculations showed that these compounds were formed through a series of primary and secondary reactions. The formation pathways of these typical MAHs were studied via the reaction energy barrier analysis, respectively. It shows that the MAHs were not only derived from the benzene ring in the SBR chain but also generated from short-chain alkenes through the Diels-Alder reaction. The obtained pyrolysis reaction mechanism provides theoretical guidance for the regulation of the pyrolysis product distribution of MAHs.

8.
J Chem Phys ; 157(18): 184105, 2022 Nov 14.
Article En | MEDLINE | ID: mdl-36379779

Revealing the effect of external applied potential on the reaction mechanism and product selectivity is of great significance in electrochemical studies. In this work, the grand canonical density functional theory method was applied to simulate the explicit electrocatalytic process of oxygen evolution reaction and electrochemical ozone production due to the O3 product sensitivity toward the applied potential. Over the Pt/Pd single atom embedded on B/N co-doped graphene (Pt/Pd-BNC) surface, crossover points of O2/O3 selectivity inversion were predicted to be 1.33 and 0.89 V vs standard hydrogen electrode, which were also consistent with the previous experimental results. An in-depth analysis of the energetic terms in the reaction free energies also found the considerable impact of the applied potential on the Helmholtz free energy term, with optimal potential predicted for the key elementary steps, and linear correlations between electrode potential (U) and reaction free energy were found for each elementary step. This study offers extensive knowledge on the potential effect on the O2/O3 selective formation on two-dimensional anode surfaces and provides new insights for investigating the reactivity/selectivity on electrode surfaces in real reaction conditions.

9.
Chem Commun (Camb) ; 58(69): 9622-9625, 2022 Aug 25.
Article En | MEDLINE | ID: mdl-35942706

The process for the direct oxidation of methane to methanol is investigated on single atom alloys using density functional theory. A catalyst search is performed across FCC metal single atom alloys. 7 single atom alloys are found as candidates and microkinetic modelling is performed. The activity and selectivity are remarkably improved over that of pure palladium metal, yet remain unideal.

10.
Cell Death Dis ; 13(6): 567, 2022 06 24.
Article En | MEDLINE | ID: mdl-35739102

Emerging evidence has shown an imbalance in M1/M2 macrophage polarization to play an essential role in osteoarthritis (OA) progression. However, the underlying mechanistic basis for this polarization is unknown. RNA sequencing of OA M1-polarized macrophages found highly expressed levels of pentraxin 3 (PTX3), suggesting a role for PTX3 in OA occurrence and development. Herein, PTX3 was found to be increased in the synovium and articular cartilage of OA patients and OA mice. Intra-articular injection of PTX3 aggravated, while PTX3 neutralization reversed synovitis and cartilage degeneration. No metabolic disorder or proteoglycan loss were observed in cartilage explants when treated with PTX3 alone. However, cartilage explants exhibited an OA phenotype when treated with culture supernatants of macrophages stimulated with PTX3, suggesting that PTX3 did not have a direct effect on chondrocytes. Therefore, the OA anti-chondrogenic effects of PTX3 are primarily mediated through macrophages. Mechanistically, PTX3 was upregulated by miR-224-5p deficiency, which activated the p65/NF-κB pathway to promote M1 macrophage polarization by targeting CD32. CD32 was expressed by macrophages, that when stimulated with PTX3, secreted abundant pro-inflammation cytokines that induced severe articular cartilage damage. The paracrine interaction between macrophages and chondrocytes produced a feedback loop that enhanced synovitis and cartilage damage. The findings of this study identified a functional pathway important to OA development. Blockade of this pathway and PTX3 may prevent and treat OA.


C-Reactive Protein , MicroRNAs , Osteoarthritis , Serum Amyloid P-Component , Synovitis , Animals , Chondrocytes/metabolism , Humans , Macrophages , Mice , MicroRNAs/metabolism , Osteoarthritis/genetics , Osteoarthritis/metabolism , Serum Amyloid P-Component/genetics , Serum Amyloid P-Component/metabolism , Synovitis/genetics , Synovitis/metabolism
11.
Nat Commun ; 13(1): 1375, 2022 Mar 16.
Article En | MEDLINE | ID: mdl-35296655

Selective conversion of methane (CH4) into value-added chemicals represents a grand challenge for the efficient utilization of rising hydrocarbon sources. We report here dimeric copper centers supported on graphitic carbon nitride (denoted as Cu2@C3N4) as advanced catalysts for CH4 partial oxidation. The copper-dimer catalysts demonstrate high selectivity for partial oxidation of methane under both thermo- and photocatalytic reaction conditions, with hydrogen peroxide (H2O2) and oxygen (O2) being used as the oxidizer, respectively. In particular, the photocatalytic oxidation of CH4 with O2 achieves >10% conversion, and >98% selectivity toward methyl oxygenates and a mass-specific activity of 1399.3 mmol g Cu-1h-1. Mechanistic studies reveal that the high reactivity of Cu2@C3N4 can be ascribed to symphonic mechanisms among the bridging oxygen, the two copper sites and the semiconducting C3N4 substrate, which do not only facilitate the heterolytic scission of C-H bond, but also promotes H2O2 and O2 activation in thermo- and photocatalysis, respectively.

12.
Ann Rheum Dis ; 81(5): 676-686, 2022 05.
Article En | MEDLINE | ID: mdl-35058228

OBJECTIVES: To investigate the role of mechanical stress in cartilage ageing and identify the mechanistic association during osteoarthritis (OA) progression. METHODS: F-box and WD repeat domain containing 7 (FBXW7) ubiquitin ligase expression and chondrocyte senescence were examined in vitro, in experimental OA mice and in human OA cartilage. Mice with Fbxw7 knockout in chondrocytes were generated and adenovirus-expressing Fbxw7 (AAV-Fbxw7) was injected intra-articularly in mice. Destabilised medial meniscus surgery was performed to induce OA. Cartilage damage was measured using the Osteoarthritis Research Society International score and the changes in chondrocyte senescence were determined. mRNA sequencing was performed in articular cartilage from Fbxw7 knockout and control mice. RESULTS: Mechanical overloading accelerated senescence in cultured chondrocytes and in mice articular cartilage. FBXW7 was downregulated by mechanical overloading in primary chondrocytes and mice cartilage, and decreased in the cartilage of patients with OA, aged mice and OA mice. FBXW7 deletion in chondrocytes induced chondrocyte senescence and accelerated cartilage catabolism in mice, as manifested by an upregulation of p16INK4A, p21 and Colx and downregulation of Col2a1 and ACAN, which resulted in the exacerbation of OA. By contrast, intra-articular injection of adenovirus expressing Fbxw7 alleviated OA in mice. Mechanistically, mechanical overloading decreased Fbxw7 mRNA transcription and FBXW7-mediated MKK7 degradation, which consequently stimulated JNK signalling. In particular, inhibition of JNK activity by DTP3, a MKK7 inhibitor, ameliorated chondrocyte senescence and cartilage degeneration CONCLUSIONS: FBXW7 is a key factor in the association between mechanical overloading and chondrocyte senescence and cartilage ageing in the pathology of OA.


Cartilage, Articular , F-Box-WD Repeat-Containing Protein 7/metabolism , Osteoarthritis , Animals , Cartilage, Articular/metabolism , Chondrocytes/metabolism , F-Box-WD Repeat-Containing Protein 7/genetics , Humans , Mice , Osteoarthritis/pathology , RNA, Messenger/metabolism
13.
Rheumatology (Oxford) ; 61(6): 2631-2643, 2022 05 30.
Article En | MEDLINE | ID: mdl-34559207

OBJECTIVES: This study aimed to investigate the role and mechanism of asporin in modulating chondrocyte senescence in OA pathology. METHODS: Asporin and senescence-related hallmark expression were examined in human and experimental OA mouse cartilage samples. Twelve-week-old male C57 mice were administered with recombinant protein (rm-asporin)- or asporin-siRNA-expressing lentiviruses via intra-articular injection once a week after destabilization of the medial meniscus (DMM) surgery to induce OA. Cartilage damage was measured using the Osteoarthritis Research Society International score. Senescence-associated ß-galactosidase (SA-ß-Gal) staining, γH2AX, p21 and p16INK4a were analysed by immunofluorescence staining and western blot to assess the specific role of asporin in chondrocyte senescence. The TGF-ß1-Smad2 signalling pathway and miR-26b-5p were further evaluated to explore the mechanism of asporin in OA. RESULTS: Asporin was upregulated in articular chondrocytes of OA patients and DMM mice and accompanied by accumulation of senescent cells. Asporin overexpression exaggerated OA progression, whereas silencing asporin restored chondrocyte homeostasis and deferred chondrocyte senescence, leading to markedly attenuated DMM-induced OA. Cellular and molecular analyses showed that asporin can be inhibited by miR-26b-5p, which was significantly downregulated in OA cartilage, leading to exacerbation of experimental OA partially through inhibition of TGF-ß1-Smad2 signalling in chondrocytes. CONCLUSIONS: Our findings indicate that asporin plays an essential role in chondrocyte senescence and OA pathogenesis. Upregulated by miR-26b-5p, asporin inhibits the TGF-ß1-Smad2 pathway to accelerate chondrocyte senescence and exacerbate cartilage degeneration. Targeting the miR-26b-5p-asporin-Smad2 axis may serve as a practical therapeutic strategy to delay chondrocyte senescence and OA development.


Cartilage, Articular , MicroRNAs , Osteoarthritis , Animals , Cartilage, Articular/metabolism , Chondrocytes/metabolism , Humans , Male , Menisci, Tibial , Mice , MicroRNAs/genetics , MicroRNAs/metabolism , Osteoarthritis/metabolism , Smad2 Protein/metabolism , Transforming Growth Factor beta1/metabolism
14.
ACS Appl Mater Interfaces ; 13(43): 50878-50891, 2021 Nov 03.
Article En | MEDLINE | ID: mdl-34672634

Two-dimensional (2D) materials have been developed into various catalysts with high performance, but employing them for developing highly stable and active nonprecious hydrogen evolution reaction (HER) catalysts still encounters many challenges. To this end, the machine learning (ML) screening of HER catalysts is accelerated by using genetic programming (GP) of symbolic transformers for various typical 2D MA2Z4 materials. The values of the Gibbs free energy of hydrogen adsorption (ΔGH*) are accurately and rapidly predicted via extreme gradient boosting regression by using only simple GP-processed elemental features, with a low predictive root-mean-square error of 0.14 eV. With the analysis of ML and density functional theory (DFT) methods, it is found that various electronic structural properties of metal atoms and the p-band center of surface atoms play a crucial role in regulating the HER performance. Based on these findings, NbSi2N4 and VSi2N4 are discovered to be active catalysts with thermodynamical and dynamical stability as ΔGH* approaches to zero (-0.041 and 0.024 eV). In addition, DFT calculations reveal that these catalysts also exhibit good deuterium evolution reaction (DER) performance. Overall, a multistep workflow is developed through ML models combined with DFT calculations for efficiently screening the potential HER and DER catalysts from 2D materials with the same crystal prototype, which is believed to have significant contribution to catalyst design and fabrication.

15.
J Colloid Interface Sci ; 599: 58-67, 2021 Oct.
Article En | MEDLINE | ID: mdl-33933797

The electrochemical synthesis of hydrogen peroxide (H2O2) provides a greener and more efficient method compared with classic catalysts containing toxic metals. Herein, we used first-principles density functional theory (DFT) calculations to investigate 174 different single-atom catalysts with graphyne substrates, and conducted a three-step screening strategy to identify the optimal noble metal-free single atom catalyst. It is found that a single Ni atom loaded on γ-graphyne with carbon vacancies (Ni@V-γ-GY) displayed remarkable thermodynamic stability, excellent selectivity, and high activity with an ultralow overpotential of 0.03 V. Furthermore, based on ab-initio molecular dynamic and DFT calculations under the H2O solvent, it was revealed that the catalytic performance for H2O2 synthesis in aqueous phase was much better than that in gas phase condition, shedding light on the hydrogen bond network being beneficial to accelerate the transfer of protons for H2O2 synthesis.

16.
J Cancer ; 11(7): 1828-1838, 2020.
Article En | MEDLINE | ID: mdl-32194794

Background: As the third confirmed gaseous transmitter, the role of hydrogen sulfide (H2S) in the pathogenesis of multiple types of cancer has been attracting increasing attention. Increased expression of cystathionine ß-synthase (CBS) and H2S in colon cancer tissue samples has been validated and tumor-derived H2S, mainly produced by CBS, stimulates bioenergetics, cell proliferation, and angiogenesis in colon cancer. Recently, the therapeutic manipulation of H2S has been proposed as a promising anticancer approach. However, the effect of aminooxyacetic acid (AOAA), which has been widely used as an inhibitor of CBS dependent synthesis of H2S, on the chemotherapeutic effect of oxaliplatin (OXA) and the underlying mechanisms remain to be illustrated. Methods: We examined the expression of CBS in human colorectal cancer specimens and matched normal mucosa by immunohistochemistry. The effect of AOAA on the sensitivity of colon cancer cells to OXA and the level of apoptosis induced by caspase cascade was investigated in both HCT116 and HT29 cell lines utilizing CCK-8 assays, flow cytometry analysis and western blot analysis. The endogenous levels of reactive oxygen species (ROS) were detected fluorescently by DCF-DA, and glutathione (GSH) levels were measured by a Total GSH Detection Kit. Tumor bearing xenograft mouse models and in vivo imaging systems were further used to investigate the effect of AOAA in vivo and immunohistochemistry (IHC) and TUNEL analysis were performed. Results: In the current study, we confirmed CBS, the main target of AOAA, is overexpressed in human colorectal cancer by immunohistochemistry. The inhibitory effect of AOAA on the synthesis of H2S was validated utilizing fluorescent probe and specific electrode. AOAA significantly reduced the IC50 values of OXA in both colon cancer cell lines. Co-incubation with AOAA elicited increased apoptosis induced by OXA, featured by increased activation of caspase cascade. Besides, AOAA further increased the levels of ROS induced by OXA and attenuated the synthesis of glutathione (GSH), which is a vital antioxidant. Besides, the results of in vivo imaging and following IHC and TUNEL analysis were in accordance with cellular experiments, indicating that AOAA sensitizes colon cancer cells to OXA via exaggerating intrinsic apoptosis. Conclusion: The results suggested that CBS is overexpressed in colorectal cancer tissues and AOAA sensitizes colon cancer cells to OXA via exaggerating apoptosis both in vitro and in vivo. Decreasing the endogenous level of GSH and consequently impaired detoxification of ROS might be one of the mechanisms underlying the effect of AOAA.

17.
Polymers (Basel) ; 11(12)2019 Nov 29.
Article En | MEDLINE | ID: mdl-31795514

Pyrolysis of styrene-butadiene rubber receives renewed attention due to its application in tackling the waste tire disposal problem while allowing energy recovery. The density functional theory calculation (DFT) and ReaxFF molecular dynamics simulation (MD) are adopted to study the pyrolysis process with the variation of temperature and pressure. The bond dissociation energies of intramonomer and intermonomer bonds in trimers with different linking methods are calculated by DFT, where the bond with low energy tends to break during the pyrolysis process. The following MD simulation shows the pyrolysis product distribution of chain segments in styrene-butadiene rubber, where bond breaking positions in MD agree well with corresponding results in DFT and experiment. The next nearest neighbor bonds (single bonds) connected with double bond or benzene usually have lower dissociation energies than other single bonds and prone to break during the pyrolysis process. And thus, the intermonomer bonds tend to break at relatively low temperatures (around 650 K in experiment) prior to intramonomer bonds, which result in the emergence of monomers. With the temperature increase, intramonomer bonds are broken and thus large fragments are further pyrolyzed into small ones (e.g., C2 and C). Besides, the pressure strongly influences the product distribution, where high pressures promote the occurrence of secondary reactions.

18.
ACS Appl Mater Interfaces ; 11(47): 44118-44123, 2019 Nov 27.
Article En | MEDLINE | ID: mdl-31682102

Activity and immobilization of catalysts in liquid-phase reactions seem not to coexist. We report here the excellent activity of an MoOx nanoparticle (NP) catalyst for d-glucose epimerization to d-mannose and the electrical immobilization of NPs in a flow reaction. Prior to that, a green and one-pot method to synthesize the MoOx NPs (3.05 nm) via oxidizing metal Mo by hydrogen peroxide was presented. The NPs overwhelmed the reported catalysts including epimerase for d-glucose epimerization, originating from a strong interaction between the NPs and the reactant that was demonstrated by ex situ and in situ characterizations and theoretical calculations. The electrically charged feature of NPs inspired us to find a convenient way to "immobilize" them inside an activated carbon bed, and thereby, a flow reactor was assembled. The continuous epimerization was run under 24 V for 16 days with an almost unchanged activity, and only 3.2% of total Mo was lost.

19.
Saudi Med J ; 40(8): 755-765, 2019 Aug.
Article En | MEDLINE | ID: mdl-31423511

OBJECTIVES: To analyze the heterogeneous functions of secreted protein acidic and rich in cysteine (SPARC) from different origins and in different tumor microenvironments with the purpose of determining its clinical significance. Methods: The PubMed, CINAHL, Cochrane, Web of Science and Embase databases were utilized. Studies that focused on the effects of SPARC expression on solid tumor progression and clinical implications were used. The different outcomes including overall survival and disease-free survival were analyzed to evaluate their relations with tumor- and stroma-derived SPARC expression. Results: A total of 26 studies including 5,939 patients were enrolled in the present meta-analysis. Tumor-derived SPARC overexpression was significantly related with poor overall survival (hazard ratio: 1.478; 95% CI: 1.143-1.910; p=0.003), and a similar tendency was also observed in disease-free survival (hazard ratio: 1.476; 95% CI: 0.993-2.195; p=0.054). However, the hazard ratios for overall survival and disease-free survival did not present a statistical trend in stromal SPARC overexpression. Tumor type subgroup analysis revealed marked heterogeneity among outcomes. In pancreatic cancer, SPARC overexpression in the stroma was significantly associated with poorer overall survival and disease-free survival. In colorectal cancer, SPARC overexpression in the stroma was associated with better disease-free survival. Conclusion: For the majority of solid tumors, SPARC in cancer cells may be an unfavorable indicator for long-term survival for patients. As for stromal expression, SPARC indicates a poorer prognosis in pancreatic cancer, but a better disease-free survival in colorectal cancer. Secreted protein acidic and rich in cysteine might be a potential biomarker for solid tumor prognosis.


Neoplasms/metabolism , Osteonectin/metabolism , Tumor Microenvironment , Biliary Tract Neoplasms/metabolism , Biliary Tract Neoplasms/mortality , Breast Neoplasms/metabolism , Breast Neoplasms/mortality , Colorectal Neoplasms/metabolism , Colorectal Neoplasms/mortality , Disease-Free Survival , Esophageal Neoplasms/metabolism , Esophageal Neoplasms/mortality , Esophageal Squamous Cell Carcinoma/metabolism , Esophageal Squamous Cell Carcinoma/mortality , Humans , Lung Neoplasms/metabolism , Lung Neoplasms/mortality , Lymphoma, Large B-Cell, Diffuse/metabolism , Lymphoma, Large B-Cell, Diffuse/mortality , Nasopharyngeal Carcinoma/metabolism , Nasopharyngeal Carcinoma/mortality , Nasopharyngeal Neoplasms/metabolism , Nasopharyngeal Neoplasms/mortality , Neoplasms/mortality , Pancreatic Neoplasms/metabolism , Pancreatic Neoplasms/mortality , Prognosis , Proportional Hazards Models , Stomach Neoplasms/metabolism , Stomach Neoplasms/mortality , Survival Rate
20.
Phys Chem Chem Phys ; 21(24): 12895-12904, 2019 Jun 28.
Article En | MEDLINE | ID: mdl-31157340

Brittle porous materials offer a wide variety of promising applications due to their high surface-area-to-volume ratios and controllable porous structures. Getting comprehensive knowledge of the structural stability is of great significance for avoiding the irreversible destruction of these materials. Based on interpenetrating bicontinuous structures, we innovatively adopted a sequential mesoscopic simulation strategy to show the pore size effect on the mechanical stability, which involves structural evolution by the mesoscale dynamic density functional method and mechanical behavior by the highly efficient lattice spring model. Simulation results show that specific surface areas, Young's moduli and fracture strains decrease with the increase of pore widths on the premise of the same porosity. More uniform stress/strain distributions are observed in structures with smaller pore sizes or more uniform defect distributions. From the local stress distribution analysis, the effective stress transfer occurs in the solid phase, which runs through the simulation box along the tensile direction, and the mechanical disparity among systems with different pore sizes is due to different volume fractions and microstructures of the solid phase. Larger pore sizes result in lower Weibull moduli due to the increased heterogeneity and a less predictable failure behavior, and the concentrated defects usually result in mechanical anisotropy.

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