Reactive oxygen species and oxidative stress in acute pancreatitis:Pathogenesis and new therapeutic interventions

Acute pancreatitis(AP)is a common acute gastrointestinal disorder affecting approximately 20%of patients with systemic inflammatory responses that may cause pancreatic and peripancreatic fat necrosis.This condition often progresses to multiple organ failure,significantly increasing morbidity and mortality.Oxidative stress,characterized by an imbalance between the body’s reactive oxygen species(ROS)and antioxidants,activates the inflammatory signaling pathways.Although the pathogenesis of AP is not fully understood,ROS are increasingly recognized as critical in the disease's progression and development.Modulating the oxidative stress pathway has shown efficacy in mitigating the progression of AP.Despite numerous basic studies examining this pathway,comprehensive reviews of recent research remain sparse.This systematic review offers an in-depth examination of the critical role of oxidative stress in the pathogenesis and progression of AP and evaluates the therapeutic potential of antioxidant interventions in its management.

Anti-oxidative stress treatment and current clinical trials

Oxidative stress disturbs the balance between the production of reactive oxygen species(ROS)and the detoxification biological process.It plays an important role in the development and progression of many chronic diseases.Upon exposure to oxidative stress or the inducers of ROS,the cellular nucleus undergoes some biological processes via different signaling pathways,such as stress adaption through the forkhead box O signaling pathway,inflammatory response through the IκB kinase/nuclear factor-κB signaling pathway,hypoxic response via the hypoxia-inducible factor/prolyl hydroxylase domain proteins pathway,DNA repair or apoptosis through the p53 signaling pathway,and antioxidant response through the Kelch-like ECH-associated protein 1/nuclear factor E2-related factor 2 signaling pathway.These processes are involved in many diseases.Therefore,oxidative stress has gained more attraction as a targeting process for disease treatment.Meanwhile,anti-oxidative stress agents have been widely explored in pre-clinical trials.However,only limited clinical trials are performed to evaluate the efficacy of anti-oxidative stress agents or antioxidants in diseases.In this letter,we further discuss the current clinical trials related to anti-oxidative stress treatment in different diseases.More pre-clinical studies and clinical trials are expected to use anti-oxidative stress strategies as disease treatment or dietary supplementation to improve disease treatment outcomes.

New therapeutic strategy with extracorporeal membrane oxygenation for refractory hepatopulmonary syndrome after liver transplant: A case report

BACKGROUND Due to the lack of published literature about treatment of refractory hepatopulmonary syndrome(HPS)after liver transplant(LT),this case adds information and experience on this issue along with a treatment with positive outcomes.HPS is a complication of end-stage liver disease,with a 10%-30%incidence in cirrhotic patients.LT can reverse the physiopathology of this process and restore normal oxygenation.However,in some cases,refractory hypoxemia persists,and extracorporeal membrane oxygenation(ECMO)can be used as a rescue therapy with good results.CASE SUMMARY A 59-year-old patient with alcohol-related liver cirrhosis and portal hypertension was included in the LT waiting list for HPS.He had good liver function(Model for End-Stage Liver Disease score 12,Child-Pugh class B7).He had pulmonary fibrosis and a mild restrictive respiratory pattern with a basal oxygen saturation of 82%.The macroaggregated albumin test result was>30.Spirometry demonstrated a forced expiratory volume in one second(FEV1)of 78%,forced vital capacity(FVC)of 74%,FEV1/FVC ratio of 81%,diffusion capacity for carbon monoxide of 42%,and carbon monoxide transfer coefficient of 57%.He required domiciliary oxygen at 2 L/min(16 h/d).The patient was admitted to the intensive care unit(ICU)and extubated in the first 24 h,needing high-flow therapy and non-invasive ventilation and inhaled nitric oxide afterwards.Reintubation was needed after 72 h.Due to the non-response to supportive therapies,installation of ECMO was decided with progressive recovery after 9 d.Extubation was possible on the tenth day,maintaining a high-flow nasal cannula and de-escalating to conventional oxygen therapy after 48 h.He was discharged from ICU on postoperative day(POD)20 with a 90%-92%oxygen saturation.Steroid recycling was needed twice for acute rejection.The patient was discharged from hospital on POD 27 with no symptoms,with an 89%-90%oxygen saturation.CONCLUSION Due to the favorable results observed,ECMO could become the central axis of treatment of HPS and refractory hypoxemia after LT.

Effects of microwave oxygen plasma treatments on microstructure and Ge-V photoluminescent properties of diamond particles

The microstructure and Ge-V photoluminescent properties of diamond particles treated by microwave oxygen plasma are investigated.The results show that in the first 5 min of microwave plasma treatment,graphite and disordered carbon on the surface of the particles are etched away,so that diamond with regular crystal plane,smaller lattice stress,and better crystal quality is exposed,producing a Ge-V photoluminescence(PL)intensity 4 times stronger and PL peak FWHM(full width at half maximum)value of 6.6 nm smaller than the as-deposited sample.It is observed that the cycles of‘diamond is converted into graphite and disordered carbon,then the graphite and disordered carbon are etched’can occur with the treatment time further increasing.During these cycles,the particle surface alternately appears smooth and rough,corresponding to the strengthening and weakening of Ge-V PL intensity,respectively,while the PL intensity is always stronger than that of the as-deposited sample.The results suggest that not only graphite but also disordered carbon weakens the Ge-V PL intensity.Our study provides a feasible way of enhancing the Ge-V PL properties and effectively controlling the surface morphology of diamond particle.

Heat treatment bimetallic PdAu nanocatalyst for oxygen reduction reaction

Pd-based nanocatalyst is a potential oxygen reduction oxidation(ORR)catalyst because of its high activity in alkaline medium and low cost.In this work,bimetallic Pd Au nanocatalysts are prepared by one-pot hydrothermal method using triblock pluronic copolymers,poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide)(PEO19-PPO69-PEO19)(P123)as reducer and stabilizer,and heat-treatment method is applied to regulate catalyst structure and improve catalyst activity.The results show that the heat treatment can agglomerate the catalyst to a certain extent,but effectively improve the crystallinity and alloying degree of the catalyst.The ORR performance of the Pd Au nanocatalysts obtained under different heat treatment conditions is systematically investigated.Compared with commercial Pd black and Pd Au catalyst before heat treatment,the ORR performance of Au Pd nanocatalyst obtained after heat treatment for one hour at 500℃ has been enhanced.The Pd Au nanocatalysts after heat treatment also display enhanced anti-methanol toxicity ability in acidic medium.

Hyperbaric Oxygen Treatment Improves Hearing Level via Attenuating TLR4/NF-κB Mediated Inflammation in Sudden Sensorineural Hearing Loss Patients

Objective Hyperbaric oxygen treatment(HBOT)has demonstrated efficacy in improving hearing levels of patients with idiopathic sudden sensorineural hearing loss(ISSHL);however,the underlying mechanisms are not well understood.HBOT alleviates the inflammatory response,which is mediated by Toll-like receptor(TLR)4 and nuclear factor(NF)-κB.In this study we investigated whether HBOT attenuates inflammation in ISHHL patients via alteration of TLR4 and NF-κB expression.Methods ISHHL patients(n=120)and healthy control subjects(n=20)were enrolled in this study.Patients were randomly divided into medicine group treated with medicine only(n=60)and HBO group receiving both HBOT and medicine(n=60).Audiometric testing was performed pre-and posttreatment.TLR4,NF-кB,and TNF-αexpression in peripheral blood of ISSHL patients and healthy control subjects was assessed by ELISA before and after treatment.Results TLR4,NF-κB,and TNF-αlevels were upregulated in ISSHL patients relative to healthy control subjects;the levels were decreased following treatment and were lower in the HBO group than that in the medicine group post-treatment(P<0.05 and P<0.01).Conclusion HBOT alleviates hearing loss in ISSHL patients by suppressing the inflammatory response induced by TLR4 and NF-κB signaling.

Facile synthesis of hierarchically porous carbons by controlling the initial oxygen concentration in-situ carbonization of ZIF-8 for efficient water treatment

The state-of-the-art approaches for adjusting the structural characteristics of porous carbons are the aftertreatments, which are complicated and time consuming. In this work, a facile approach was developed, i.e., controlling the initial oxygen concentration in-situ during the direct carbonization of zeolitic imidazole framework-8(ZIF-8), to adjust the pore structure and prepare hierarchically porous carbons. The introduction of oxygen can significantly affect the crystalline and pore structures of porous carbons, and promote the pore widening and the formation of mesopores. An appropriate initial oxygen concentration can notably enhance the surface area and mesopore volume of porous carbon, and then improve the adsorption capacity toward methylene blue(MB) dye from water by 3.4 times. The developed approach is more efficient at lower carbonization temperature.Moreover, the introduction of oxygen can increase the ratio of HO\\C_O groups on the carbon surface, leading to enhanced interaction with MB molecules and higher adsorption capacity toward MB. The as-prepared porous carbons exhibit superior adsorption capacities toward MB dye as compared to the reported ZIF-8 derived carbons. These findings would aid the development of porous carbon materials with high performance.

Effect of oxygen content and heat treatment on carbide precipitation behavior in PM Ni-base superalloys

The influence of oxygen content and heat treatment on the evolution of carbides in a powder metallurgy （PM） Ni-base superalloy was characterized. The results reveal that oxygen content has little influence on the precipitation of carbides inside the particles. However, under the consolidated state, stable Ti oxides on the particle surface act as nuclei for the precipitation of prior particle boundaries （PPB）. Also, oxygen can diffuse internally along grain boundaries under compressive stress, which favors the precipitation of carbides inside the particles. Therefore, a higher amount of carbides will appear with more oxygen content in the case of consolidated alloys. It is also observed that PPB can be disrupted into discontinuous particles at 1200℃, but this carbide network is hard to be eliminated completely. The combined MC-M23C6 morphology approves the nucleation and growth mechanism of carbide evolution.

Hyperbaric oxygen therapy as a new treatment approach for Alzheimer's disease

Hyperbaric oxygen therapy as a new treatment approach for Alzheimer’s disease（AD）：Alongside the increase in life expectancy,the prevalence of age-related disorders,such as neurodegenerative diseases,is on the rise.For example,AD,the most common form of dementia in the elderly,accounts for 60–80%of all dementia cases.

Oxygen Transfer and Hydrodynamics in a Flexible Fibre Biofilm Reactor for Wastewater Treatment

A flexible fibre biofilm reactor was developed for treatment of organic wastewaters.The hydrodynamic characteristics and mass transfer coefficients of oxygen were studied and compared with those of the conventional activated sludge processes.Tracer experiments were performed to obtain the residence time distributions of the reactors.The results indicated that both reactors could be treated as mixed flow reactors.The effects of flow rates of water and air on the overall mass transfer coefficient of oxygen were investigated,and the correlations between the mass transfer coefficient and the ratio of flow rates were obtained.Compared to the conventional activated sludge reactor,the mass transfer coefficients in the flexible fibre reactor were similar to but slightly lower,and less sensitive to the variation in the ratio of flow rates.It indicated that the fibre packing in the reactor hindered the oxygen transfer to some extent.

Influence of hyperbaric oxygenation treatment (HBOT) on clinical outcomes (recurrent myocardial infarction and survival rate) during five-year monitoring period after acute myocardial infarction

Surgical treatments of acute myocardial infarction (MI) possess a high clinical effectiveness, but there are fixed limitations, related to the patient’s state, which are limited by medical resources and organizational problems. The development of new medical technologies provides a better and effective non-surgical treatment of acute MI and increases long-term prognosis in this category of patients. The study aims to investigate the influence of hyperbaric oxygenation treatment on clinical outcomes (survival rate and recurrent myocardial infarction (rMI)) during the five-year period of monitoring. The study involved 697 patients who suffered from acute MI, having undergone the standard treatment. The patients were randomly divided into two groups: Group 1 (reference, n = 363);Group 2 (test, n = 334). Patients of Group 2 were given the traditional treatment, accompanied with HBOT (isopression for forty minutes at a working pressure of 0.03 MPa). HBOT was applied first through the fifth day following MI. The treatment course included six cycles, once per day. The clinical assessment was focused on clinical outcome: rMI and mortality related to cardiovascular events. HBOT application that accompanied the acute MI with traditional pharmacotherapy has been proved to reduce rMI within five years following inpatient discharge (rMI rate was 14% in the reference group and 5.4% in the test group, χ2 = 13.3, р < 0.05). The combination of HBOT with traditional methods in treating acute MI makes it possible to raise the five-year survival rate from 84.4% up to 95.9%.

Enriched Oxygen BAC Method in Advanced Treatment of Textile Dyeing-printing & Alkali-peeling Wastewater

A novel Pressurized Enriched Oxygen Biological Activated Carbon （PRBAC） method in treating secondary effluent of textile dying-printing ＆ alkali peeling wastewater was configured. The PRBAC reactor simply increased reactor pressure to create an eurtched dissolved oxygen （DO） environment to stimulate the bioactivities of microbes on GAC surface for removing refractory organic matter. Rapid Small- Scaled Colunm Test （RSSCT） was carried out to evaluate the adsorption characteristics of target stream constituents, and over 80% COD components were poorly adsorbable while about 82.5% color inducing matter and 85% UV254 surrogated matter were readily adsorbable. Compared with performances of normal BAC reactor under conventional DO condition, PRBAC achieved 20%, 10% and 50% more removal in COD, color and NH3-N abatement.

Methane dehydro-aromatization over Mo/HZSM-5 catalysts in the absence of oxygen:Effect of steam-treatment on catalyst stability

The effect of steam-treatment to HZSM-5 zeolite and Mo/HZSM-5 with a steaming time range of 0.5-1 h on the catalytic performance of methane dehydro-aromatization （MDA） over Mo/HZSM-5 catalyst prepared with impregnation has been studied in detail in combination with the characterization of 1H MAS NMR technique. Both the deactivation rate constant （kd） and the Brtnsted acid sites per unit cell were calculated to quantitatively evaluate the stability of Mo/HZSM-5 catalysts treated with steam at 813 K before and after impregnation of molybdenum species, and the corresponding variation of their Brtnsted acid sites. The results reveal that a V-shape relationship between kd and the number of B 1 acid sites per unit cell is presented on Mo/HZSM-5 catalyst under the tested steam-treatment and reaction conditions.

Bimetallic catalysts as electrocatalytic cathode materials for the oxygen reduction reaction in microbial fuel cell:A review

Microbial fuel cell(MFC) is one synchronous power generation device for wastewater treatment that takes into account environmental and energy issues, exhibiting promising potential. Sluggish oxygen reduction reaction(ORR) kinetics on the cathode remains by far the most critical bottleneck hindering the practical application of MFC. An ideal cathode catalyst should possess excellent ORR activity, stability, and costeffectiveness, experiments have demonstrated that bimetallic catalysts are one of the most promising ORR catalysts currently. Based on this, this review mainly analyzes the reaction mechanism(ORR mechanisms, synergistic effects), advantages(combined with characterization technologies), and typical synthesis methods of bimetallic catalysts, focusing on the application effects of early Pt-M(M = Fe, Co, and Ni) alloys to bifunctional catalysts in MFC, pointing out that the main existing challenges remain economic analysis, long-term durability and large-scale application, and looking forward to this. At last, the research trend of bimetallic catalysts suitable for MFC is evaluated, and it is considered that the development and research of metal-organic framework(MOF)-based bimetallic catalysts are still worth focusing on in the future, intending to provide a reference for MFC to achieve energy-efficient wastewater treatment.

Hyperbaric-oxygen treatment: An adjunctive therapy in acute renal failure due to crush injury

Objective: Major seismic events leave their survivors trapped under the rubble leading to extensive muscle damage and its devastating sequale of hemodynamic and metabolic disturbances and acute renal failure. Hypoxemia aggravated during each hemodialysis (HD) session is important in acute renal failure patients with massive tissue injury. We retrospectively analyzed the adjunctive role of hyperbaric-oxygen (HBO) therapy in patients treated with HD for acute renal failure due to crush injury in terms of dialysis duration. Patients and methods: 16 patients admitted after the Marmara earthquake to Istanbul Faculty of Medicine were treated with HBO. Only 8 (2M, 6F, mean age: 24.8 + 7.3 years) of them had required HD treatment. 29 (16M, 13F, mean age: 34.6 + 12.9 years) crush syndrome patients treated with HD but not with HBO were taken as controls and the clinical and laboratory data of the two groups were compared. Results: The mean duration time under the rubble for the HBO group was 9.4 + 3.2 hours. Mainly lower extremity fasciotomies were performed at 15.6 + 14.8 hours after extrication. There were no amputations in this group. There were three amputations in the control group. The mean number of HD sessions was 9.2 + 6.7/patient for 10.9+9.6 days until renal functions recovered and the patients had 27.4 + 15.6 HBO sessions until the recovery of their lesions. There were no correlations between the number of HBO sessions and any laboratory parameter nor the number of HD sessions. There was no statistical difference in the need for HD between the HBO and control group. Conclusions: Our results could not demonstrate any beneficial effect of HBO treatment in terms of HD duration;however, the valuable contribution of the HBO treatment was to increase the salvage of crushed limbs.

Curcumin pretreatment and post-treatment both improve the antioxidative ability of neurons with oxygen-glucose deprivation

Recent studies have shown that induced expression of endogenous antioxidative enzymes thr- ough activation of the antioxidant response element/nuclear factor erythroid 2-related factor 2 （Nrf2） pathway may be a neuroprotective strategy. In this study, rat cerebral cortical neurons cultured in vitro were pretreated with 10 ktM curcumin or post-treated with 5 pM curcumin, respectively before or after being subjected to oxygen-glucose deprivation and reoxygenation for 24 hours. Both pretreatment and post-treatment resulted in a significant decrease of cell injury as indicated by propidium iodide/Hoechst 33258 staining, a prominent increase of Nrf2 protein expression as indicated by western blot analysis, and a remarkable increase of protein expression and enzyme activity in whole cell lysates of thioredoxin before ischemia, after ischemia, and after reoxygenation. In addition, post-treatment with curcumin inhibited early DNA/RNA oxidation as indicated by immunocytochemistry and increased nuclear Nrf2 protein by inducing nuclear accumulation of Nrf2. These findings suggest that curcumin activates the expression of thi- oredoxin, an antioxidant protein in the Nrf2 pathway, and protects neurons from death caused by oxygen-glucose deprivation in an in vitro model of ischemia/reperfusion. We speculate that pharmacologic stimulation of antioxidant gene expression may be a promising approach to neu- roprotection after cerebral ischemia.

Effects of hyperbaric oxygen treatment on GCS after traumatic brain injury in patients

Objective To evaluate the effects of hyperbaric oxygen therapy (HBOT) on Glasgow Coma Scale (GCC) after traumatic brain injury (TBI) in patients. Methods One hundred and thirty-eight patients with traumatic brain injury were treated by routine therapy combined with HBOT and 29 patients by routine therapy.

不同采后处理对恭城月柿褐变、活性氧代谢及糖类的影响

本文分析了有氧、真空和真空+1-MCP三种采后处理方式对脱涩后柿子贮藏过程中果实褐变、活性氧代谢和糖类的影响,并对褐变与各指标的相关性进行分析。真空和真空+1-MCP组柿子贮藏过程中的褐变指数BI低于有氧组,其中真空+1-MCP组褐变程度最低;三种采后处理柿子贮藏过程中SOD、APX活性分别呈下降和上升的趋势,真空组柿子SOD活性最低,真空和真空+1-MCP条件下柿子APX活性高于有氧组;真空和真空+1-MCP抑制柿子CAT活性的增加,减少H2O2积累,同时抑制羟自由基的能力和抗坏血酸含量较低。真空和真空+1-MCP组柿子还原糖含量低于有氧组,其中真空+1-MCP组增加最慢,从贮藏开始时的14.10%增加至12 d时的14.87%;真空+1-MCP组柿子果胶含量下降缓慢。相关性分析可知,不同采后处理柿子贮藏过程中柿子褐变与各指标的相关性并不相同,但柿子褐变指数BI均与果胶呈负相关,与还原糖呈正相关。综合可知真空和真空+1-MCP条件更有利于抑制脱涩后月柿的褐变。

PVDF/PVA共混膜的制备及其在去除污水COD中的应用

以聚乙烯醇(PVA)、聚偏氟乙烯(PVDF)为原料,聚乙烯吡咯烷酮为溶剂,制备了PVDF/PVA共混膜。将该膜应用于膜生物反应器处理污水,测试化学需氧量(COD)去除率和膜的使用性能。结果表明:膜的水通量随PVA加入量的增加而逐渐增加,在牵伸比为1.7时,膜的水通量达到最大值;平板膜用清水清洗后,膜的水通量恢复率较高,膜的运行周期经第一次清洗后下降了18 h,经第二次和第三次清洗后,膜的运行周期基本稳定在6~8 h,COD去除率高于90%,表明该膜具有良好的使用性能。

氧含量变化对Ti-38Nb-4Zr-xO合金显微组织及力学性能的影响

采用高真空非自耗电弧熔炼炉对Ti-38Nb-4Zr-xO(x=0,0.3,0.6(质量分数))3种合金进行熔炼,并将他们分别在900、500℃下进行固溶时效1 h处理,运用金相显微镜(optical microscopy,OM)、X射线衍射仪(X-ray diffractometer,XRD)、扫描电子显微镜(scanning electron microscope,SEM)、透射电子显微镜(transmission elec‐tron microscope,TEM)、纳米压痕仪(nanoindenter)、静态热机械分析仪(thermo-mechanical analyzer,TMA)和万能试验机(universal testing machine,UTM)对Ti-38Nb-4Zr-xO合金进行表征,探究氧(O)含量变化对固溶时效合金组织及性能的影响。结果表明:固溶处理后Ti-38Nb-4Zr-xO合金均未检测到淬火马氏体α"相存在,他们均呈现出单一β相组织,其晶粒尺寸大小随着O含量增加而减小;经时效处理后,Ti-38Nb-4Zr-xO合金析出ω相和α相,同时O会延缓(或抑制)上述两相的分解;添加O和固溶时效处理均能使Ti-38Nb-4Zr-xO合金的抗拉强度、弹性模量和硬度提升,O的质量分数在0~0.6范围内,固溶态下每增加0.1的O元素,抗拉强度约提升50 MPa,弹性模量约提升1.5 GPa。