簇-金属氧化物助剂电子相互作用调控的Ru原子簇催化剂用于温和条件下合成氨反应

氨是重要的化肥原料,也是颇具潜力的氢能源载体,对于可再生能源的储存、运输和终端利用至关重要.然而,传统Haber-Bosch工艺合成氨的反应条件苛刻,需要高温高压条件,并消耗大量化石能源及排放大量二氧化碳.可再生能源电解水制氢耦合温和合成氨新技术(eHB),不仅能实现可再生能源电力的“消纳和调峰”,而且可进行低成本、跨地域长距离存储运输,并可将“绿氨”与氢能产业相结合.然而,现有的高温高压合成氨催化剂与eHB工艺相不匹配,因此,迫切需要开发温和条件下高效合成氨催化剂技术,以实现可再生能源电力电解制氢体系和合成氨技术互补融合.目前,虽然助剂对于Ru基纳米簇(≥1 nm)合成氨催化剂的影响规律已得到了广泛研究,但它们对于Ru原子簇催化剂的作用机制尚不清楚,需要进一步揭示.本文考察了Ba及Ce助剂对Ru原子簇催化剂的影响规律,并分析了其作用机制.首先,通过简单的浸渍法将Ba和/或Ce物种掺杂到Ru原子簇催化剂(2 wt%Ru ACCs),制得Ba/Ce/2 wt%Ru ACCs催化剂;然后,通过一系列实验考察了这些催化剂的合成氨性能,并利用多种表征手段对其进行了深入分析.合成氨性能测试结果表明,添加Ba和Ce助剂后,2 wt%Ru ACCs催化剂的合成氨速率明显提高,在400℃和1 MPa下,Ba/Ce/2 wt%Ru ACCs催化剂的合成氨反应速率达到56.2 mmolNH_(3) gcat^(-1) h^(-1),是2 wt%Ru ACCs的7.5倍,且催化剂表现出较好的稳定性,在稳定运行140 h后活性未见明显降低.球差校正电子显微镜和X射线吸收精细结构谱结果表明,负载Ba和/或Ce后,Ru以Ru_(3)原子簇形式存在.X射线吸收近边结构谱和X射线光电子能谱结果表明,Ru与Ba及Ce物种之间存在较强的簇-金属氧化物助剂电子相互作用,可促进电子转移到Ru物种,形成富电子状态的Ru,进而促使电子转移到N_(2)的p*反键轨道,提高温和条件下合成氨反应速率.利用25%N_(2)+75%D_(2)气氛下的原位红外光谱研究催化剂的合成氨反应机理,结果表明,在Ba/Ce/2 wt%Ru ACCs催化剂表面同时检测到N_(2)D_(2)物种和N_(2)D_(x)物种的振动吸收峰,说明添加Ba和/或Ce物种没有改变Ru原子簇催化剂活化N_(2)的方式,N_(2)仍是通过加氢的路径合成氨.综上,本文考察了助剂对Ru原子簇的影响规律,揭示了其作用机制,为设计高效的温和条件合成氨催化剂提供参考.

Robust Distributed Model Predictive Control for Formation Tracking of Nonholonomic Vehicles

Dear Editor,This letter proposes a robust distributed model predictive control(MPC) strategy for formation tracking of a group of wheeled vehicles subject to constraints and disturbances. Formation control has attracted significant interest because of its applications in searching and exploration [1], [2].

Heterostructural NiFeW disulfide and hydroxide dual‐trimetallic core‐shell nanosheets for synergistically effective water oxidatio

A stable and highly active core‐shell heterostructure electrocatalyst is essential for catalyzing oxygen evolution reaction(OER).Here,a dual‐trimetallic core‐shell heterostructure OER electrocatalyst that consists of a NiFeWS_(2) inner core and an amorphous NiFeW(OH)_(z)outer shell is designed and synthesized using in situ electrochemical tuning.The electrochemical measurements of different as‐synthesized catalysts with a similar mass loading suggest that the core‐shell Ni_(0.66)Fe_(0.17)W_(0.17)S_(2)@amorphous NiFeW(OH)_(z) nanosheets exhibit the highest overall performance compared with that of other bimetallic reference catalysts for the OER.Additionally,the nanosheet arrays were in situ grown on hydrophilic‐treated carbon paper to fabricate an integrated three‐dimensional electrode that affords a current density of 10 mA cm^(−2) at a small overpotential of 182 mV and a low Tafel slope of 35 mV decade^(−1) in basic media.The Faradaic efficiency of core‐shell Ni_(0.66)Fe_(0.17)W_(0.17)S_(2)@amorphous NiFeW(OH)_(z) is as high as 99.5% for OER.The scanning electron microscope,transmission electron microscope,and X‐ray photoelectron spectroscopy analyses confirm that this electrode has excellent stability in morphology and elementary composition after long‐term electrochemical measurements.Importantly,density functional theory calculations further indicate that the core‐shell heterojunction increased the conductivity of the catalyst,optimized the adsorption energy of the OER intermediates,and improved the OER activity.This study provides a universal strategy for designing more active core‐shell structure electrocatalysts based on the rule of coordinated regulation between electronic transport and active sites.

Pachymic acid exerts antitumor activities by modulating the Wnt/β-catenin signaling pathway via targeting PTP1B

Objective:To determine the inhibitory effects of pachymic acid on lung adenocarcinoma(LUAD)cells and elucidate its underlying mechanism.Methods:CCK-8,wound healing,Transwell,Western blot,tube formation,and immunofluorescence assays were carried out to measure the effects of various concentrations of pachymic acid on LUAD cell proliferation,metastasis,angiogenesis as well as autophagy.Subsequently,molecular docking technology was used to detect the potential targeted binding association between pachymic acid and protein tyrosine phosphatase 1B(PTP1B).Moreover,PTP1B was overexpressed in A549 cells to detect the specific mechanisms of pachymic acid.Results:Pachymic acid suppressed LUAD cell viability,metastasis as well as angiogenesis while inducing cell autophagy.It also targeted PTP1B and lowered PTP1B expression.However,PTP1B overexpression reversed the effects of pachymic acid on metastasis,angiogenesis,and autophagy as well as the expression of Wnt3a andβ-catenin in LUAD cells.Conclusions:Pachymic acid inhibits metastasis and angiogenesis,and promotes autophagy in LUAD cells by modulating the Wnt/β-catenin signaling pathway via targeting PTP1B.

Finite-Time Stabilization for Constrained Discrete-time Systems by Using Model Predictive Control

In this paper, a model predictive control(MPC)framework is proposed for finite-time stabilization of linear and nonlinear discrete-time systems subject to state and control constraints. The proposed MPC framework guarantees the finite-time convergence property by assigning the control horizon equal to the dimension of the overall system, and only penalizing the terminal cost in the optimization, where the stage costs are not penalized explicitly. A terminal inequality constraint is added to guarantee the feasibility and stability of the closed-loop system.Initial feasibility can be improved via augmentation. The finite-time convergence of the proposed MPC is proved theoretically,and is supported by simulation examples.

Development of a new Cox model for predicting long-term survival in hepatitis cirrhosis patients underwent transjugular intrahepatic portosystemic shunts

BACKGROUND Transjugular intrahepatic portosystemic shunt(TIPS)placement is a procedure that can effectively treat complications of portal hypertension,such as variceal bleeding and refractory ascites.However,there have been no specific studies on predicting long-term survival after TIPS placement.AIM To establish a model to predict long-term survival in patients with hepatitis cirrhosis after TIPS.METHODS A retrospective analysis was conducted on a cohort of 224 patients who un-derwent TIPS implantation.Through univariate and multivariate Cox regression analyses,various factors were examined for their ability to predict survival at 6 years after TIPS.Consequently,a composite score was formulated,encompassing the indication,shunt reasonability,portal venous pressure gradient(PPG)after TIPS,percentage decrease in portal venous pressure(PVP),indocyanine green retention rate at 15 min(ICGR15)and total bilirubin(Tbil)level.Furthermore,the performance of the newly developed Cox(NDC)model was evaluated in an in-ternal validation cohort and compared with that of a series of existing models.RESULTS The indication(variceal bleeding or ascites),shunt reasonability(reasonable or unreasonable),ICGR15,post-operative PPG,percentage of PVP decrease and Tbil were found to be independent factors affecting long-term survival after TIPS placement.The NDC model incorporated these parameters and successfully identified patients at high risk,exhibiting a notably elevated mortality rate following the TIPS procedure,as observed in both the training and validation cohorts.Additionally,in terms of predicting the long-term survival rate,the performance of the NDC model was significantly better than that of the other four models[Child-Pugh,model for end-stage liver disease(MELD),MELD-sodium and the Freiburg index of post-TIPS survival].CONCLUSION The NDC model can accurately predict long-term survival after the TIPS procedure in patients with hepatitis cirrhosis,help identify high-risk patients and guide follow-up management after TIPS implantation.

Research on the feasibility of storage and estimation model of storage capacity of CO_(2)in fissures of coal mine old goaf

The concept of the carbon cycle in the old goaf of a coal mine based on CO_(2)utilization and storage was put forward adhering to the principle of low-carbon development,utilization of space resources in old goafs,and associated gas resources development.Firstly,the evolution characteristics of overburden fissures in the goaf of the case was studied using a two-dimensional physical similarity simulation test,the sealing performance of the caprocks after stabilization was analyzed,and the fissures were counted and classi-fied.Then,the process of gaseous CO_(2)injection in the connected fissure was simulated by Ansys Fluent software,and the migration law and distribution characteristics of CO_(2)under the condition of gaseous CO_(2)injection were analyzed.Finally,the estimation models of free CO_(2)storage capacity in the old goaf were constructed considering the proportion of connected fissure and the effectiveness of CO_(2)injection.The CO_(2)storage capacity in the old goaf of the case coal mine was estimated.The results showed that a caprock group of“hard-thickness low-permeability hard-thickness”was formed after the caprock-fissures system in the goaf of the case tended to be stable vertically.The connected fissure,occlude cracks,and micro-fractures in the goaf accounted for 85.5%,8.5%,and 6%of the total fissures,respectively.Gaseous CO_(2)first migrated to the bottom of the connected fissure after CO_(2)was injected into the goaf,then spread horizontally along the bottom of the connected fissure after reaching the bottom,and finally spread longitudinally after filling the bottom of the entire connected fissure.The theoretical and effective storage capacities of free CO_(2)at normal temperature and pressure in the old goaf of the case were 9757 and 7477 t,respectively.The effective storage capacity of free CO_(2)at normal temperature and pressure in the old goaf after all minefield mined was 193404 t.The research can provide some reference for the coal mining industry to help the goal of“carbon peaking and carbon neutrality”.

Quercetin induced HepG2 cells apoptosis through ATM/JNK/STAT3 signaling pathways

Liver cancer is the seventh most common malignant tumor in the world and is the second highest cause of death due to cancer.Quercetin,a flavonoid with low toxicity,widely exists in various fruits and vegetables.It has the potential to be a therapeutic agent against various cancers.This study aimed to demonstrate the anti-tumor effect of quercetin on HepG2 cells.Quercetin suppressed the HepG2 cell proliferation in a dose-dependent manner in cell viability assay.Induction of cell apoptosis was confirmed by apoptotic cells population(sub-G1 peak)detected by flow cytometer.A decrease in mitochondrial membrane potential and caspase-3 activation were also demonstrated in this study.Furthermore,quercetin induced HepG2 cell apoptosis through ROS-mediated phosphorylated ataxia-telangiectasia mutated,c-Jun Nterminal kinases,signal transducer,and activator of transcription 3(STAT-3),and Bax signaling pathways.These results suggest that quercetin has the potential to become an effective drug against the tumor.

Vision-Based Fixed-Time Uncooperative Aerial Target Tracking for UAV

Dear Editor,In this letter,a vision-based fixed-time control is proposed for an unmanned aerial vehicle(UAV)with actuator saturation to track an uncooperative target.The fixed-time control is designed in backstepping framework.The relative states between UAV and the target are not directly measured,and are estimated by an onboard monocular camera.

Inhibition of H_(2)O_(2)-induced apoptosis of GC2-spg cells by functionalized selenium nanoparticles with lentinan through ROSmediated ERK/p53 signaling pathways

AH_(2)O_(2)-induced oxidative stress injury cell model was established to investigate the antioxidant effect of nanoselenium on mouse spermatocyte lines and the regulation mechanism of the expression level and activity of seleniumcontaining antioxidant enzymes induced by oxidative stress.A safe and effective nano-drug system of functionalized selenium-containing nanoparticles(SeNPs)was developed with lentinan(LNT)(SeNPs@LNT).Mice spermatocyte line GC2-spg cells were treated with SeNPs@LNT(1,2,4,8,16,32μM)for 24-72 h to evaluate the cytotoxicity of selenium.GC2-spg cells were randomly divided into the following groups:control,hydrogen peroxide(H_(2)O_(2)),SeNPs@LNT,and H_(2)O_(2)+SeNPs@LNT groups.H_(2)O_(2)+SeNPs@LNT group was pretreated with SeNPs@LNT 4μM for 12 h,followed by H_(2)O_(2)600μM for 8 h.The cell viability decreased in the H_(2)O_(2) group and increased significantly in the SeNPs@LNT group.Compared with the H_(2)O_(2) group,the SeNPs@LNT+H_(2)O_(2) group exhibited obvious red fluorescence,indicating a higher level of mitochondrial membrane potential.The content of intracellular reactive oxygen species(ROS)in the SeNPs@LNT group reduced significantly,and the intensity of green fluorescence in the SeNPs@LNT+H_(2)O_(2) group decreased significantly compared with the H_(2)O_(2) group,indicating the inhibitory effect of SeNPs@LNT on the generation of ROS-induced oxidative stress.The activity of GPx and SOD increased significantly in the SeNPs@LNT group.The expression of p53 decreased significantly under the intervention of nano-selenium,and GPx1 expression increased.In the oxidative stress group,the expressions of DNA damage-related proteins and apoptosis-related proteins were higher than those in other groups.Thus,SeNPs@LNT can promote GC2-spg cell proliferation,improve GPx and SOD activities,remove intracellular ROS,and reduce mitochondrial damage and functional abnormalities caused by oxidative stress by regulating the ERK and p53 protein levels.SeNPs@LNT has good biological activity and antioxidant effect,which can be used to protect the male reproductive system from oxidative stress.

Inhibition of H_(2)O_(2)-induced TM3 cell apoptosis by oxidative stress by lentinan functionalized selenium nanoparticles through JAK2/STAT-3 and P53 pathways

Background:Nano-selenium has been widely used in antiviral and anticancer therapy,and has the advantages of good targeting and low toxicity.For the first time,we combined male reproduction with nano-selenium to investigate its antioxidant effect.This study investigated the protective effect of lentinan functionalized selenium nanoparticles on oxidative stress injury of the hydrogen peroxide(H_(2)O_(2))-induced Leydig cell line,TM3.Methods:The suitable concentration of nano-selenium treatment to promote cell proliferation was also discussed.The concentration of 4μM could significantly promote the growth of TM3 cells.Oxidative stress damage was caused using an 800μM concentration of hydrogen peroxide.The cells were divided into four groups:normal control group,oxidative stress treatment group,H_(2)O_(2)+SeNPs@LNT group,and SeNPs@LNT group.The H_(2)O_(2)+SeNPs@LNT group was pretreated with 4μM of SeNPs@LNT for 12 h,followed by 800μM of H_(2)O_(2)for 8 h.Results:Nano-selenium could significantly promote the proliferation and viability of TM3 cells.SeNPs@LNT treatment increased the level of mitochondrial membrane potential in normal cells and slowed down the decline in mitochondrial membrane potential level caused by oxidative stress injury.In addition,the increase in reactive oxygen species caused by oxidative stress was inhibited by SeNPs@LNT treatment.The apoptosis of TM3 cells was detected,and SeNPs@LNT alleviated the necrosis and apoptosis of TM3 cells induced by H_(2)O_(2).Nano-selenium plays a protective role against oxidative H_(2)O_(2)-induced stress injury in TM3 cells through the changes in the Janus kinase 2/signal transducer and activator of transcription 3 signaling pathway and P53 pathway,and the expression levels of other related proteins,protein kinase B(AKT)and C3.Conclusion:SeNPs@LNT exhibited good biological activity and antioxidant effect and can thus be used to protect the male reproductive system from oxidative stress.

Neural mechanism of acupuncture-modulated gastric motility

AIM: To investigate the acupuncture-modulated gastric motility and its underlying neural mechanism.METHODS: Intragastric pressure and/or waves of gastric contraction in rats were recorded by intrapyloric balloon and changes of gastric motility induced by acupuncture stimulation were compared with the background activity before any stimulation. Gastro-vagal or splanchnic-sympathetic nerves were recorded or cut respectively for investigating the involvement of autonomic nerve pathways. Spinalization experiment was also performed.RESULTS: Acupuncture-stimulation by exciting Aδ and/or C afferent fibers, could only modulate gastric motility. Acupuncture-stimulation on fore- and hind-limbs evoked a moderate gastric motility followed by increased vagus discharges with unchanged sympathetic activity, while the same stimulus to the acupoints in abdomen resulted in reversed effects on gastric motility and autonomic nervous activities. The inhibitory gastric response was completely abolished by splanchnic denervation, but the facilitative gastric response to stimulation of acupoints in limbs was not influenced, which was opposite to the effect when vagotomy was performed. The similar depressive effects were produced by the stimulation at the acupoints homo-segmental to the gastric innervation in the animals with or without spinalization. However, the facilitation induced by the stimulation at the acupoints hetero-segmental to the gastric innervation was not observed in the spinalized animals.CONCLUSION: Facilitative effects of stimulating hetero-segmental acupoints are involved in the intact preparation of vagal nerves and spinal cord, while the inhibitory response induced by stimulating homo-segmental acupoints is involved in the intact preparation of sympathetic nerves. Only the acupuncture-stimulation with intensity over the threshold of Aδ and/or C afferent fibers can markedly modulate gastrointestinal motility.

Cystatin C is a biomarker for predicting acute kidney injury in patients with acute-on-chronic liver failure

AIM:To investigate serum cystatin C level as an early biomarker for predicting acute kidney injury(AKI)in patients with acute-on-chronic liver failure(ACLF).METHODS:Fifty-six consecutive patients with hepatitis B virus-related ACLF who had normal serum creatinine(Cr)level(<1.2 mg/dL in men,or<1.1 mg/dL in women)were enrolled in the Liver Failure Treatment and Research Center of Beijing 302 Hospital between August 2011 and October 2012.Thirty patients with chronic hepatitis B(CHB)and 30 healthy controls in the same study period were also included.Measurement of serum cystatin C(CysC)was performed by a particle-enhanced immunonephelometry assay using the BN Prospec nephelometer system.The ACLF patients were followed during their hospitalization period.RESULTS:In the ACLF group,serum level of CysC was 1.1±0.4 mg/L,which was significantly higher(P<0.01)than those in the healthy controls(0.6±0.3mg/L)and CHB patients(0.7±0.2 mg/L).During the hospitalization period,eight ACLF patients developed AKI.Logistic regression analysis indicated that CysC level was an independent risk factor for AKI development(odds ratio=1.8;95%CI:1.4-2.3,P=0.021).The cutoff value of serum CysC for prediction of AKI in ACLF patients was 1.21 mg/L.The baseline CysC-based estimated glomerular filtration rate(eGFR CysC)was significantly lower than the creatinine-based eGFR(eGFR CG and eGFR MDRD)in ACLF patients with AKI,suggesting that baseline eGFR CysC represented early renal function in ACLF patients while the Cr levels were still within the normal ranges.CONCLUSION:Serum CysC provides early prediction of renal dysfunction in ACLF patients with a normal serum Cr level.

Acupuncture at heterotopic acupoints enhances jejunal motility in constipated and diarrheic rats

AIM: To investigate the effect and mechanism of acupuncture at heterotopic acupoints on jejunal motility, particularly in pathological conditions.

Electroacupuncture at ST25 inhibits jejunal motility:Role ofsympathetic pathways and TRPV1

AIM: To investigate whether electroacupuncture(EA) at ST25 affects jejunal motility in vivo and if so, whether a sympathetic pathway is involved.METHODS: Jejunal motility was assessed using a manometric balloon placed in the jejunum approximately about 3-5 cm away from the suspensory ligament of the duodenum in anesthetized animals. The effects of EA at ST25 were measured in male Sprague-Dawley rats, some of which were treated with propranolol or clenbuterol(EA intensities: 1, 3, 5, 7, and 9 m A), and in male transient receptor potential vanilloid-1(TRPV1)(capsaicin receptor) knockout mice(EA intensities: 1, 2, and 4 m A).RESULTS: Anesthetized rats exhibited three types of fasting jejunal motor patterns(types A, B, and C), and only type C rats responded to EA stimulation. In type C rats, EA at ST25 significantly suppressed the motor activity of the jejunum in an intensity-dependent manner. The inhibitory effect of EA was weakened by propranolol(β adrenoceptor antagonist) and disappeared with clenbuterol(β adrenoceptor agonist) induced inhibition of motility, suggesting that the effect of EA on motility is mediated via a sympathetic pathway. Compared with wild-type mice, EA at ST25 was less effective in TRPV1 knockout mice, suggesting that this multi-modal sensor channel participates in the mechanism. CONCLUSION: EA at ST25 was found to inhibit jejunal motility in an intensity-dependent manner, via a mechanism in which sympathetic nerves and TRPV1 receptors play an important role.

Effective regularity in modulation on gastric motility induced by different acupoint stimulation

AIM： To investigate whether manual acupuncture at representative acupoints in different parts of the body can modulate responses of gastric motility in rats and regular effects in different acupoint stimulation. METHODS： The gastric motor activity of rats was recorded by the intrapyloric balloon. The changes of gastric motility induced by the stimulation were compared with the background activity in intragastric pressure and/or waves of gastric contraction recorded before any stimulation. Morphological study was also conducted by observing the Evans dye extravasation in the skin after mustard oil injection into the intragastric mucous membrane to certify cutaneous innervations of blue dots related to gastric segmental innervations. RESULTS： In all six rats that received mustard oil injections into intragastric mucosa, small blue dots appeared in the skin over the whole abdomen, but mainly in peri-midline upper- and middle- abdomen and middle-back, a few in thigh and groin. It may speculate that cutaneous innervations of blue dots have the same distribution as gastric segmental innervations. Acustimulation in acupoints of head-neck, four limbs, upper chest-dorsum and Iower-dorsum induced markedly augmentation of gastric motility （acupoints on headneck such as St-2： n = 16, 105.19 ± 1.36 vs 112.25 ± 2.02 and St-3： n = 14, 101.5 ± 1.75 vs 109.36 ± 1.8; acupoints on limbs such as Sp-6： n = 19, 100.74 ± 1.54 vs 110.26 ± 3.88; St-32： n = 17, 103.59 ± 1.64 vs 108.24 ± 2.41; St-36： n = 16, 104.81 ± 1.72 vs 110.81 ± 2.74 and U-11： n = 17, 106.47 ± 2.61 vs 114.77 ± 3.77, P 〈 0.05-0.001）. Vigorous inhibitory regulations of gastric motility induced by acu-stimulation applied in acupoints on whole abdomen and middle-dorsum were significantly different as compared with the controls before acu-stimulation （abdomen acupoints such as Cv-12： n = 11, 109.36 ± 2.09 vs 101 ± 2.21; Cv-6： n = 18, 104.39 ± 1.42 vs 91.83 ± 3.22 and St-21： n = 12, 107 ± 2.97 vs 98.58 ± 2.81; acupoints on middledorsum such as BI-17： n = 19, 100.63 ± 1.4 vs 92.21 ± 2.07 and BI-21： n = 19, 103.84 ± 1.48 vs 97.58 ± 2.16, P 〈 0.05-0.001）. CONCLUSION： Regular regulatory effects of facilitation and inhibition on gastric motility appear to be somatotopically organized in the acupoints of whole body, and the effective regularity of site-special acupoints on gastric motility is involved in segmental innervations between stomach and acupoints.

Role of neuronal nitric oxide synthase and inducible nitric oxide synthase in intestinal injury in neonatal rats

AIM： TO investigate the dynamic change and role of neuronal nitric oxide synthase （nNOS） and inducible nitric oxide synthase （iNOS） in neonatal rat with intestinal injury and to define whether necrotizing enterocolitis （NEC） is associated with the levels of nitric oxide synthase （NOS） in the mucosa of the affected intestine tissue. METHODS： Wistar rats less than 24 h in age received an intraperitoneal injection with 5 mg/kg lipopolysaccharide （LPS）. Ileum tissues were collected at 1, 3, 6, 12 and 24 h following LPS challenge for histological evaluation of NEC and for measurements of nNOS and iNOS. The correlation between the degree of intestinal injury and levels of NOS was determined. RESULTS： The LPS-injected increase in injury scores pups showed a significant versus the control. The expression of nNOS protein and mRNA was diminished after LPS injection. There was a negative significant correlation between the nNOS protein and the grade of median intestinal injury within 24 h. The expression of iNOS protein and mRNA was significantly increased in the peak of intestinal injury. CONCLUSION： nNOS and iNOS play different roles in LPS-induced intestinal injury. Caution should be exerted concerning potential therapeutic uses of NOS inhibitors in NEC.

Clinical characteristics and corticosteroid therapy in patients with autoimmune-hepatitis-induced liver failure

AIM: To investigate the clinical features, response to corticosteroids, and prognosis of autoimmune hepatitis (AIH)-induced liver failure in China.

Identification and Typing of Respiratory Adenoviruses in Guangzhou, Southern China Using a Rapid and Simple Method

Human adenoviruses (HAdVs), especially HAdV-B3, -E4 and -B7, are associated with Acute Respiratory Disease in Chinese children, and occasionally in adults. In order to establish and document the profiles of the respiratory adenovirus pathogen among children in Guangzhou, Southern China, a rapid, simple and practical method for identification and typing of respiratory adenoviruses was developed and evaluated. One pair of universal PCR primers was designed according to the conserved region of the hexon gene, which can detect not only HAdV-B3, -E4 and -B7, but also HAdV-B14, -F40 and -F41, with a specific 300bp PCR product. Three pairs of type-specific PCR primers were also designed according to the hypervariable regions of the hexon gene to type HAdV-B3, -E4 and -B7 by three independent PCR reactions, making it easy to optimize the PCR conditions. By using this method, one hundred throat swab specimens collected during Oct 2010 to Dec 2011 and suspected of being positive for adenoviral infection were identified and typed for adenoviruses. Of these samples, fifty-five were adenovirus-positive. The most common HAdV type was HAdV-B3, identified in 92.7% of samples, which is not only consistent with the data reported in 2004-2006, but also consistent with the recent report in Hangzhou, eastern China, indicating that HAdV-B3 has been circulating in Guangzhou, and maybe in eastern China, for many years. The method for the respiratory adenovirus identification and typing we developed is rapid, simple and practical, which has a potential in the real-time surveillance of circulating adenovirus strains and also to provide etiological evidence for the adenovirus-relative disease control and prevention in China.

Wave-current interaction with a vertical square cylinder at different Reynolds numbers

Large eddy simulation is performed to study three-dimensional wave-current interaction with a square cylinder at different Reynolds numbers, ranging from 1,000 to 600,000. The Keulegan-Carpenter number is relevantly a constant of 0.6 for all cases. The Strouhal number, the mean and the RMS values of the effective drag coefficient in the streamwise and transverse directions are computed for various Reynolds numbers, and the velocity of a rep- resentative point in the turbulent zone is simulated to find the turbulent feature. It is found that the wave-current interaction should be considered as three-dimensional flow when the Reynolds number is high; under wave-current effect, there exists a critical Reynolds number, and when the Reynolds number is smaller than the critical one, current effect on wave can be nearly neglected; conversely, with the Reynolds number increasing, wave-currentstructure interaction is sensitive to the Reynolds number.