Research Progress on Atomically Dispersed Fe-N-C Catalysts for the Oxygen Reduction Reaction.

The efficiency and performance of proton exchange membrane fuel cells (PEMFCs) are primarily influenced by ORR electrocatalysts. In recent years, atomically dispersed metal-nitrogen-carbon (M-N-C) catalysts have gained significant attention due to their high active center density, high atomic utilization, and high activity. These catalysts are now considered the preferred alternative to traditional noble metal electrocatalysts. The unique properties of M-N-C catalysts are anticipated to enhance the energy conversion efficiency and lower the manufacturing cost of the entire system, thereby facilitating the commercialization and widespread application of fuel cell technology. This article initially delves into the origin of performance and degradation mechanisms of Fe-N-C catalysts from both experimental and theoretical perspectives. Building on this foundation, the focus shifts to strategies aimed at enhancing the activity and durability of atomically dispersed Fe-N-C catalysts. These strategies encompass the use of bimetallic atoms, atomic clusters, heteroatoms (B, S, and P), and morphology regulation to optimize catalytic active sites. This article concludes by detailing the current challenges and future prospects of atomically dispersed Fe-N-C catalysts.

RuO2 Catalysts for Electrocatalytic Oxygen Evolution in Acidic Media: Mechanism, Activity Promotion Strategy and Research Progress.

Proton Exchange Membrane Water Electrolysis (PEMWE) under acidic conditions outperforms alkaline water electrolysis in terms of less resistance loss, higher current density, and higher produced hydrogen purity, which make it more economical in long-term applications. However, the efficiency of PEMWE is severely limited by the slow kinetics of anodic oxygen evolution reaction (OER), poor catalyst stability, and high cost. Therefore, researchers in the past decade have made great efforts to explore cheap, efficient, and stable electrode materials. Among them, the RuO2 electrocatalyst has been proved to be a major promising alternative to Ir-based catalysts and the most promising OER catalyst owing to its excellent electrocatalytic activity and high pH adaptability. In this review, we elaborate two reaction mechanisms of OER (lattice oxygen mechanism and adsorbate evolution mechanism), comprehensively summarize and discuss the recently reported RuO2-based OER electrocatalysts under acidic conditions, and propose many advanced modification strategies to further improve the activity and stability of RuO2-based electrocatalytic OER. Finally, we provide suggestions for overcoming the challenges faced by RuO2 electrocatalysts in practical applications and make prospects for future research. This review provides perspectives and guidance for the rational design of highly active and stable acidic OER electrocatalysts based on PEMWE.

WCx-Supported RuNi Single Atoms for Electrocatalytic Oxygen Evolution.

Single-atom catalysts anchored to oxide or carbonaceous substances are typically tightly coordinated by oxygen or heteroatoms, which certainly impact their electronic structure and coordination environment, thereby affecting their catalytic activity. In this study, we prepared a stable oxygen evolution reaction (OER) catalyst on tungsten carbide using a simple pyrolysis method. The unique structure of tungsten carbide allows the atomic RuNi catalytic site to weakly bond to the surface W and C atoms. XRD patterns and HRTEM images of the WCx-RuNi showed the characteristics of phase-pure WC and W2C, and the absence of nanoparticles. Combined with XPS, the atomic dispersion of Ru/Ni in the catalyst was confirmed. The catalyst exhibits excellent catalytic ability, with a low overpotential of 330 mV at 50 mA/cm2 in 1 m KOH solutions, and demonstrates high long-term stability. This high OER activity is ascribed to the synergistic action of metal Ru/Ni atoms with double monomers. The addition of Ni increases the state density of WCx-RuNi near the Fermi level, promoting the adsorption of oxygen-containing intermediates and enhancing electron exchange. The larger proximity of the d band center to the Fermi level suggests a strong interaction between the d electrons and the valence or conduction band, facilitating charge transfer. Our research offers a promising avenue for reasonable utilization of inexpensive and durable WCx carrier-supported metal single-atom catalysts for electrochemical catalysis.

Ag Nanoparticles and Rod-Shaped AgCl Decorated Porous PEDOT as a Bifunctional Material for Hydrogen Evolution Catalyst and Supercapacitor Electrode.

PEDOT-Ag/AgCl is a highly promising material with dual functions of hydrogen evolution reaction (HER) and supercapacitors. In this study, a simple low-temperature stirring and light irradiation method was used to synthesize PEDOT-Ag/AgCl on the surface. Then, PEDOT-Ag/AgCl was analyzed using X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, and transmission electron microscopy. PEDOT-Ag/AgCl reacted in 1 M KOH alkaline electrolyte with an overpotential of 157 mV at 20 mA·cm-2 and a Tafel slope of 66.95 mv·dec-1. Owing to the synergistic effect of PEDOT and Ag/AgCl, this material had a small resistance (1.7 Ω) and a large specific capacitance (978 F·g-1 at current density of 0.5 A·g-1). The synthesis method can prepare nanostructured PEDOT with uniformly-distributed Ag nanoparticles and rod-shaped AgCl on the surface, which can be used as both HER electrocatalysts and supercapacitor electrodes.

Facile Synthesis of Z-Scheme Ag3PO4/Sulfur-Doped g-C3N4 Heterojunction Hybrids with Enhanced Visible Light Photocatalytic Performance.

Ag3PO4/sulfur-doped g-C3N4 heterojunctions were fabricated by the means of a facile calcination and co-precipitation method. Structural characterization suggested that Ag3PO4 was successfully loaded onto sulfur-doped g-C3N4. The absorption band edges of sulfur-doped g-C3N4 were shifted to the longer wavelength in comparison with bulk g-C3N4. The Ag3PO4/sulfur-doped g-C3N4 heterojunctions manifested substantially higher visible-light photocatalytic performance as compared with Ag3PO4/bulk g-C3N4. Photoluminescence spectra suggested that the stable Ag3PO4/SGCN heterojunctions could effectively address the electron-hole recombination rate, together with remarkably enhancing the photocatalytic activity. The enhancement of light absorption and better dispersion in Ag3PO4/sulfur-doped g-C3N4 provide more migration channels, together with posing crucial responsibility for the enhanced photocatalytic performance.

An EAV-HP insertion in 5' Flanking region of SLCO1B3 causes blue eggshell in the chicken.

The genetic determination of eggshell coloration has not been determined in birds. Here we report that the blue eggshell is caused by an EAV-HP insertion that promotes the expression of SLCO1B3 gene in the uterus (shell gland) of the oviduct in chicken. In this study, the genetic map location of the blue eggshell gene was refined by linkage analysis in an F(2) chicken population, and four candidate genes within the refined interval were subsequently tested for their expression levels in the shell gland of the uterus from blue-shelled and non-blue-shelled hens. SLCO1B3 gene was found to be the only one expressed in the uterus of blue-shelled hens but not in that of non-blue-shelled hens. Results from a pyrosequencing analysis showed that only the allele of SLCO1B3 from blue-shelled chickens was expressed in the uterus of heterozygous hens (O*LC/O*N). SLCO1B3 gene belongs to the organic anion transporting polypeptide (OATP) family; and the OATPs, functioning as membrane transporters, have been reported for the transportation of amphipathic organic compounds, including bile salt in mammals. We subsequently resequenced the whole genomic region of SLCO1B3 and discovered an EAV-HP insertion in the 5' flanking region of SLCO1B3. The EAV-HP insertion was found closely associated with blue eggshell phenotype following complete Mendelian segregation. In situ hybridization also demonstrated that the blue eggshell is associated with ectopic expression of SLCO1B3 in shell glands of uterus. Our finding strongly suggests that the EAV-HP insertion is the causative mutation for the blue eggshell phenotype. The insertion was also found in another Chinese blue-shelled breed and an American blue-shelled breed. In addition, we found that the insertion site in the blue-shelled chickens from Araucana is different from that in Chinese breeds, which implied independent integration events in the blue-shelled chickens from the two continents, providing a parallel evolutionary example at the molecular level.

PGM-free single atom catalysts for the oxygen reduction reaction in proton exchange membrane fuel cells.

The progress of proton exchange membrane fuel cells (PEMFCs) in the clean energy sector is notable for its efficiency and eco-friendliness, although challenges remain in terms of durability, cost and power density. The oxygen reduction reaction (ORR) is a key sluggish process and although current platinum-based catalysts are effective, their high cost and instability is a significant barrier. Single-atom catalysts (SACs) offer an economically viable alternative with comparable catalytic activity for ORR. The primary concern regarding SACs is their operational stability under PEMFCs conditions. In this article, we review current strategies for increasing the catalytic activity of SACs, including increasing active site density, optimizing metal center coordination through heteroatom doping, and engineering porous substrates. To enhance durability, we discuss methods to stabilize metal centers, mitigate the effects of the Fenton reaction, and improve graphitization of the carbon matrix. Future research should apply computational chemistry to predict catalyst properties, develop in situ characterization for real-time active site analysis, explore novel catalysts without the use of platinum-based catalysts to reduce dependence on rare and noble metal, and investigate the long-term stability of catalyst under operating conditions. The aim is to engineer SACs that meet and surpass the performance benchmarks of PEMFCs, contributing to a sustainable energy future.

Role of amorphous engineering and cerium doping in NiFe oxyhydroxide for electrocatalytic water oxidation.

Amorphous engineering and atomistic doping provide an effective way to improve the catalytic activity in the oxygen evolution reaction (OER) of transition metal layered double hydroxides. Herein, Cerium (Ce) was introduced into NiFe-based oxyhydroxide using a modified aqueous sol-gel procedure. Ce as an electron acceptor promoted the coupling oxidation of Ni2+/3+ in NiFe oxyhydroxide, and the activated oxyhydroxide showed excellent catalytic activity in OER. The amorphous NiFeCe oxyhydroxide electrocatalyst demonstrated great modified OER catalytic activity under alkaline conditions and excellent cyclic stability, with an overpotential of only 284 mV at 50 mA cm-2, which was significantly better than amorphous NiFe oxyhydroxide and crystalline NiFeCe oxyhydroxide. Theoretical investigations further indicated that the overpotential of the rate-determining step (*OOH deprotonation) decreased from 0.66 to 0.41 V after Ce doping and strong electron interaction, effectively reducing the dependence of proton activity in the solution of OER, and optimizing the adsorption/desorption process of related oxygen-containing species in the reaction. This work also provides a good reference for optimizing OER activity by using rare-earth-metal induced electronic regulation strategies.

Iron clusters regulate local charge distribution in Fe-N4 sites to boost oxygen electroreduction.

The atomically-dispersed and nitrogen-coordinated iron (FeNC) on a carbon catalyst is a potential non-noble metal catalyst that can replace precious metal electrocatalysts. However, its activity is often unsatisfactory owing to the symmetric charge distribution around the iron matrix. In this study, atomically- dispersed Fe-N4 and Fe nanoclusters loaded with N-doped porous carbon (FeNCs/FeSAs-NC-Z8@34) were rationally fabricated by introducing homologous metal clusters and increasing the N content of the support. FeNCs/FeSAs-NC-Z8@34 exhibited a half-wave potential of 0.918 V, which exceeded that of the commercial benchmark Pt/C catalyst. Theoretical calculations verified that introducing Fe nanoclusters can break the symmetric electronic structure of Fe-N4, thus inducing charge redistribution. Furthermore, it can optimize a part of Fe 3d occupancy orbitals and accelerate OO fracture in OOH* (rate-determining step), thus significantly improving oxygen reduction reaction activity. This work provides a reasonably advanced pathway to modulate the electronic structure of the single-atom center and optimize the catalytic activity of single-atom catalysts.

Fabrication of polymer-based self-assembly nanocarriers loaded with a crizotinib and gemcitabine: potential therapeutics for the treatment of endometrial cancer.

Combination therapy in cancer therapy has been widely used for its positive attributes, such as minimizing the undesirable side effects of chemotherapies and enhancing the therapeutic effects on different cancers. Compared with free drugs crizotinib (CRZ) and gemcitabine (GEM), CRZ@GEM-NPs could remarkably improve the cytotoxicity for endometrial cancer (EC) cells (Ishikawa cells and KLE cells) after treatment with MTT assay. In this study, CRZ and GEM were conjugated to tri-block copolymer poly(ε-caprolactone)-poly(ethylene glycol)-poly(ε-caprolactone) (PCL-PEG-PCL, known as NPs). The fabricated nanoparticles were characterized by the high-resolution transmission electron microscopy (HR-TEM), and the particles size and zeta potential were investigated by the dynamic light scattering analysis. Further, the morphological features of the EC cell lines were examined by the biochemical staining assays. Morphological changes in endometrial cells morphology revealed by nuclear fragmentation and nuclear condensation (the hallmarks of apoptosis) were noted upon treatment with CRZ@GEM-NPs to the Ishikawa and KLE cancer cells. In addition, resulting in the highest ratio of apoptosis and mitochondrial membrane potential shows the cell death through the mitochondrial membrane potential. In vivo, systemic toxicity studies showed no histological changes and substantial blood biochemical with the near-normal appearance of the organs upon treatment with CRZ@GEM-NPs. Overall, the targeted combination suitable therapeutic framework may be a promising candidate for improved EC therapy.

Synergies of Atomically Dispersed Mn/Fe Single Atoms and Fe Nanoparticles on N-Doped Carbon toward High-Activity Eletrocatalysis for Oxygen Reduction.

PGM-free (platinum group metal) electrocatalysts are intensively investigated and used as low-cost catalysts for the oxygen reduction reaction (ORR) in the field of fuel cells, but further studying their performance improvement methods and actual reaction mechanism is still a big a challenge. In this work, a novel eletrocatalyst containing atomically dispersed Mn/Fe single atoms (SAs) and Fe nanoparticles (NPs) on N-doped carbonaceous (nanosheet/nanotube hybrids) is fabricated via a simple pyrolysis method. This high-activity ORR electrocatalyst has higher half-wave potential (E1/2 = 0.91 V) and superior long-term durability in alkaline solutions and outperforms Pt/C catalysts, which can be ascribed to the synergetic interaction between Mn/Fe SAs and Fe-NPs. FeNPs/MnFeSAs-NC-25 has stronger reactant adsorption ability and a lower dissociation energy barrier than FeNPs/FeSAs-NC, which is conducive to breaking the O-O bond and accelerating ORR kinetics. This work presents a method to synthesize carbon-based electrocatalysts with high ORR activity and stability and shows that a variety of active sites encapsulated in N-doped carbonaceous materials can be a class of competitive candidates for PGM-free electrocatalysts.

Precise constructed atomically dispersed Fe/Ni sites on porous nitrogen-doped carbon for oxygen reduction.

Exploring highly-efficient noble-metal-free electrocatalysts for oxygen reduction reaction (ORR) is crucial for preparation of rechargeable metal-air batteries. Herein, FeNi-mIm (guest) was loaded on the surface of ZIF-8 (host) via a novel host-guest strategy, and the resulting ZIF-8@FeNi(mIm)X precursors can be converted to FeNi SAs/NC catalysts with controllable structures. Robust metal-organic framework (MOF)-derived atomically dispersed Fe/Ni dual single atom electrocatalysts for ORR were developed, followed by pyrolysis of the precursors. Characterizations showed that the atomically-dispersed Fe/Ni active sites were uniformly embedded in the N-doped carbon framework. As a result, the ORR performance was obviously improved with lower half-wave potential (E1/2 = 0.91 V) in alkaline media. Such improvement is mainly attributed to the synergy of fully-exposed bimetallic single atom active sites caused by the interaction of Fe/Ni 3d orbitals. The lower adsorption energy of intermediate hydroxyl groups on the active sites and the smaller ORR energy barrier were calculated by the density functional theory. The novelty FeNi SAs/NC catalysts showed faster ORR dynamics in the rate-determining step of four-electron transfer. The synthesis strategy reported here provides an efficient approach to construct high performance dual single-atom catalysts with fully-exposed active sites on the surface.

Highly Dispersed CoO Embedded on Graphitized Ordered Mesoporous Carbon as an Effective Catalyst for Selective Fischer-Tropsch Synthesis of C5+ Hydrocarbons.

Herein, we report the high Fischer-Tropsch synthesis performance of the Co-based catalysts supported on graphitized ordered mesoporous carbon (GMC-900) by using a facile strategy. Compared with CMK-3 and active carbon (AC), the obtained GMC-900 by using pollution-free soybean oil as a carbon source exhibited enhanced catalytic performance after loading Co species due to its highly crystallized graphitic structure and uniform dispersion of CoO. As a result, Co/GMC-900 was an effective catalyst with the maximum C5+ selectivity of 52.6%, which much outperformed Co/CMK-3 and Co/AC. This research provides an approach to produce advanced Co-based catalysts with satisfactory performance for efficient Fischer-Tropsch synthesis.

Designing hierarchical iron doped nickel-vanadium hydroxide microsphere as an efficient electrocatalyst for oxygen evolution reaction.

Exploring highly active and inexpensive electrocatalysts for oxygen evolution reaction (OER) is considered to be one of the preconditions for the development of energy and environment-related technologies. Nickel-based layered double hydroxides (LDHs) are extensively-studied OER electrocatalysts, but they still require relatively high overpotentials to achieve threshold current densities. In this work, iron-doped nickel-vanadium hydroxide microspheres (Fe-doped NiV HMS) were synthesized by doping iron ions into the NiV HMS through a facile cation-exchange method. The Fe-doped NiV HMS are hollow hierarchical structure stacked by high-density perpendicularly-lying nanosheets, which provide enough space for electrolyte penetration and diffusion. Owing to optimized composition and hollow hierarchical structure, the Fe-doped NiV HMS exhibits excellent electrocatalytic performance, which possessed a very low running overpotential (255 mV at 10 mA cm-2) and a smallest Tafel slope (56 mV dec-1) compared with hierarchical NiV HMS toward OER. Electrochemical results and density functional theory (DFT) manifest that Fe doping could regulate the electronic structure of NiV HMS, thus improving its electrical conductivity and electron transfer rate, and thus enhancing its catalytic activity. This research provides a convenient way to prepare Ni-based hydroxides as promising OER catalysts.

Constructing atomically-dispersed Mn on ZIF-derived nitrogen-doped carbon for boosting oxygen reduction.

Exploring durable and highly-active non-noble-metal nanomaterials to supersede Pt-based nanomaterials is an effective way, which can reduce the cost and boost the catalytic efficiency of oxygen reduction reaction (ORR). Herein, we constructed atomically-dispersed Mn atoms on the ZIF-derived nitrogen-doped carbon frameworks (Mn-Nx/NC) by stepwise pyrolysis. The Mn-Nx/NC relative to pure nitrogen-doped carbon (NC) exhibited superior electrocatalytic activity with a higher half-wave potential (E 1/2 = 0.88 V) and a modest Tafel slope (90 mV dec-1) toward ORR. The enhanced ORR performance of Mn-Nx/NC may be attributed to the existence of Mn-Nx active sites, which can more easily adsorb intermediates, promoting the efficiency of ORR. This work provides a facile route to synthesize single-atom catalysts for ORR.

An Efficient Catalyst Derived from Carboxylated Lignin-Anchored Iron Nanoparticle Compounds for Carbon Monoxide Hydrogenation Application.

Catalytic activity and target product selectivity are strongly correlated to the size, crystallographic phase, and morphology of nanoparticles. In this study, waste lignin from paper pulp industry is employed as the carbon source, which is modified with carboxyl groups at the molecular level to facilitate anchoring of metals, and a new type of carbon-based catalyst was obtained after carbonization. As a result, the size of the metal particles is effectively controlled by the chelation between -COO- and Fe3+. Furthermore, Fe/CM-CL with a particle size of 1.5-2.5 nm shows excellent catalytic performance, the conversion of carbon monoxide reaches 82.3%, and the selectivity of methane reaches 73.2%.

One-dimensional nitrogen-doped carbon frameworks embedded with zinc-cobalt nanoparticles for efficient overall water splitting.

Metal-organic frameworks (MOFs)-derived catalysts exhibit highly-efficient hydrogen or oxygen evolution performance on water splitting. However, it is an urgent problem to construct bifunctional electrocatalysts for both hydrogen and oxygen evolution performance. Herein, we adopted Ag nanowires as templates to prepare one-dimensional Ag nanowire@ZIF-8@ZIF-67 precursors (1D AgNW@ZIF-8@ZIF-67). Through pyrolysis, AgNW@ZIF-8@ZIF-67 precursors transformed into nitrogen-doped carbon frameworks (NCF) embedded with zinc-cobalt (ZnCo) nanoparticles on the surface of Ag NWs (denoted as Ag@ZnCo/NCF nanohybrids). The nanohybrids were consisted of Ag NWs with good conductivity and ZnCo/NCF nanohybrids with rich accessible active sites. Benefiting from their large specific surface area, accessible active sites and synergistic effect among components, Ag@ZnCo/NCF nanohybrids exhibit lower overpotentials of 139 mV and 279 mV at the current density of 10 mA cm-2 for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in alkaline solution, severally. Compared with other catalysts, Ag@ZnCo/NCF nanohybrids possess smaller Tafel slope, indicating their higher catalytic activity. This work provides a new perspective for designing low-cost and highly efficient bifunctional electrocatalysts for overall water splitting.

Synthesis of three-dimensional Sn@Ti3C2 by layer-by-layer self-assembly for high-performance lithium-ion storage.

Powerful yet orderly nanostructure lithium-ion batteries (LIBs) are eagerly desired to satisfy the practical application of portable electronics and smart grids. However, the surface re-stacking and surface functionalization on the MXenes in the anode electrode severely restrict the accessibility to electrolyte ions, hindering the full utilization of their intrinsic properties. To address this challenge, we rationally design three-dimensional (3D) Sn@Ti3C2 materials and fabricate them in a unique layer-by-layer manner through self-assembly for boosting LIBs. In this design system for fast lithium-ion storage, the Ti3C2 MXene nanosheets serving as 3D scaffolds buffer the severe volume expansion and agglomeration of Sn nanoparticles (NPs) and enhance electrode conductivity at the interface. Furthermore, Sn NPs are embedded as interlayer spacers to prevent nanosheet re-stacking and provide outstanding electrochemical performance. The nanostructure can increase the lithium-ion diffusion coefficient and create additional active sites. As a result, the Sn@Ti3C2 anode exhibits a superior specific capacity up to 666 mA∙h∙g-1 at 0.5 A∙g-1 after 250 cycles. Compared with pure Sn NPs, the improved electrochemical performance of Sn@Ti3C2 can be ascribed to the high electronic conductivity of Ti3C2 MXene nanosheets. The 3D Sn@Ti3C2 materials prepared in a layer-by-layer manner through self-assembly display promising performances for LIBs.

Expression of ubiquitin-conjugating enzyme E2T in colorectal cancers and clinical implications.

Ubiquitin-conjugating enzyme E2T (UBE2T) plays a significant role in carcinogenesis. Previous studies have demonstrated that UBE2T promotes the development and progression of numerous types of cancer. However, the association between UBE2T expression and colorectal cancer (CRC) remains unclear. In the present study, UBE2T protein expression was examined in the tissues of patients with CRC via immunohistochemistry. In addition, UBE2T expression data and corresponding clinical information were obtained from The Cancer Genome Atlas (TCGA). In the clinical samples, the associations between UBE2T expression and clinicopathological factors were evaluated by the χ2 or Fisher's exact tests. In TCGA data, associations between UBE2T expression and clinical characteristics were evaluated using a logistic regression model. Overall survival was analyzed using Kaplan-Meier and Cox regression analyses. Reverse transcription-quantitative PCR (RT-qPCR) and western blotting assays were used to examine UBE2T expression in normal and CRC cell lines. Gene set enrichment analysis (GSEA) was performed on the dataset from TCGA. UBE2T protein was highly expressed in the cytoplasm of tumor cells in 29/50 clinical samples, whereas in the adjacent normal tissues, it was only highly expressed in 2/50 samples. Furthermore, UBE2T expression was associated with the N classification (P<0.001), clinical TNM stage (P<0.001) and histological grade of tumors (P=0.010). Survival analysis showed an association between high UBE2T expression and poor survival rate in patients with CRC (P=0.002). Cox regression analysis also revealed that UBE2T expression was an independent prognostic factor for these patients (P=0.006). RT-qPCR and western blotting showed that UBE2T was expressed in CRC cell lines at higher levels than that in a normal colon cell line. Analysis of TCGA data revealed that UBE2T was highly expressed in tumor samples compared with normal samples, but was not associated with prognosis. GSEA showed that high expression of UBE2T was associated with the Kyoto Encyclopedia of Genes and Genomes pathways 'cell cycle', 'oxidative phosphorylation', 'DNA replication', 'p53 signaling pathway', 'ubiquitin mediated proteolysis' and 'pentose phosphate pathway'. These results indicate that UBE2T may play an important role in the progression of CRC and serve as a potential prognostic factor during the treatment of cancer.

Oxidative stress in depressive patients with gastric adenocarcinoma.

Recent data from several studies suggest that oxidative stress is involved in the biochemical mechanisms that underlie neuropsychiatric disorders. The present study was designed to investigate oxidative stress status in depressive patients with gastric adenocarcinoma (GA) at TNM stage III. Oxidative stress, depression and expression of specific genes were monitored during a pretreatment period. Serum total antioxidant capacity, catalase, superoxide dismutase concentrations, and antisuperoxide anion capacity (A-ASC) were significantly decreased in depressive patients compared to control subjects, whereas serum malondialdehyde (MDA) levels were significantly increased. Importantly, the formation of 8-hydroxy-deoxyguanosine (8-OHdG) accumulated. Furthermore, SYBR Green real-time PCR revealed that the expression levels of human oxoguanine glycosylase 1 and APEX nuclease 1 (APEX1) were increased in depressive patients. Pearson correlation analysis revealed that depression was positively correlated with SAS, SCL-90, MDA, 8-OHdG and APEX1, but negatively correlated with A-ASC. Thus, this study confirms oxidative imbalance in depressive patients with GA, and oxidative stress may play a role in the onset and exacerbation of depression.