介孔高硅Y沸石的合成及催化裂化性能

Y型沸石拥有三维十二元环孔道(孔径0.74 nm)以及超笼结构(直径1.12 nm),在石油冶炼、石油加工、精细化学品合成以及新兴生物油的炼制方面具有重要应用.研究表明,随着Y沸石骨架硅铝比(SiO_(2)/Al_(2)O_(3),简称SAR)提高,酸中心强度增加,酸密度降低,有助于抑制裂化反应中积碳导致催化剂的失活,并提高催化剂活性;另外,随着沸石骨架硅铝比提高,Y沸石对应热/水热稳定性相应增加,有利于保持催化剂长周期使用性能.Y沸石的大孔结构使其在工业应用中有着显著的优势,然而对于大分子反应物,反应物与沸石内部活性位点的接触以及相应的产物扩散仍限制了其催化性能.介孔沸石同时具有微孔和介孔两类孔道结构,可以克服微孔沸石有限孔径尺寸带来的传质限制,进一步提高反应性能.现在工业上应用的高硅Y沸石均是通过酸脱铝,水蒸汽辅助脱铝等后处理方法获得.虽然后处理过程可以提高沸石骨架硅铝比,并引入适量的介孔结构,改善其在催化裂化反应中的传质性能,但后处理过程工序复杂,耗时耗能,而且会形成脱铝梯度,不利于其催化应用.相对而言,直接合成介孔高硅Y沸石是最理想的途径.本文以商用双亲性有机硅烷作为介孔模板剂,采用晶核、有机模板剂与低碱度协同作用(NOA-co)策略一步直接合成介孔高硅Y沸石(MSY).研究了投料硅铝比、介孔剂加入量以及加入顺序对催化性能的影响.实验发现,产品的介孔孔容、外比表面积以及SAR随着介孔剂加入量的增加而逐渐提高,当介孔剂添加过量时无法得到纯相.合成的介孔高硅Y沸石具有高SAR(9.8‒12.6)和介孔孔容(0.13‒0.22 cm^(3)/g).选取SAR=10.7的介孔高硅Y沸石样品(MSY_(10.7))进行进一步研究.扫描电镜及透射电镜结果表明,MSY沸石具有典型八面体形貌、丰富的晶内介孔及优异的热/水热稳定性,晶粒中铝分布均匀.与商用USY沸石相比,MSY沸石具有更多的强酸中心和更高的酸强度.选取大分子1,3,5-三异丙基苯的催化裂化反应探究其催化性能.H-MSY_(10.7)样品因具有大的外比表面积和丰富的酸性位点,在1,3,5-三异丙基苯催化裂化反应中表现出高的催化活性、最慢的失活速率及最高的裂解深度.进一步研究了MSY沸石在工业重油裂化反应中的催化性能.以La改性的MSY_(10.7)为活性组分,采用催化裂化催化剂制备方法制备了所需催化剂,经800℃高温老化处理后,MSY_(10.7)基催化剂的催化性能较工业流化催化裂化(FCC)催化剂转化率提高了7.64%,汽油收率提高了16.37%.综上,本文一步法制备的介孔高硅Y沸石具有优异的大分子裂化性能,为工业催化裂化催化剂的制备和性能提升提供了新方法新思路.

Comparison of clinical outcomes and postoperative recovery between two open heart surgeries:minimally invasive right subaxillary vertical thoracomy and traditional median sternotomy

Objective:To compare the clinical outcomes of minimally invasive right subaxillary vertical thoracotomy and traditional median sternotomy through right atrium in treatment of common congenital heart diseases.Methods:Clinical data of 59 cases of common congenital heart diseases treated with minimally invasive right axillary vertical thoracotomv from May,2011 to February,2013 and 77 cases of same diseases with traditional median sternotomy in the past three years were retrospectively analyzed,including atrial septal defect,membranous ventricular septal defect and partial endocardial cushion defect.The results were compared from the two groups,including the time for operation and cardiopulmonary bypass,amount of blood transfusion,postoperative drainage,ventilation time,hospital stay,and prognosis.Results:No severe complications happened in both groups,like deaths or secondery surgery caused by bleeding.No significant differences were in CPB time and postoperative ventilator time between groups(P>0.05),while for all of the operative time,the length of incision,postoperative drainage and hospital stay,minimally invasive right axillary vertical thoracotomy was superior to median sternotomy,with statistically significant differences(P<0.05).In six-month lollowup after operation,no complications of residual deformity and pericardial effusion were found in both groups bv doing echocardiography,but mild pectus carinatum was found in X patients in the traditional median sternotomy group(traditional groupi.whereas patients in another group were well recovered.Conclusions:Minimally invasive right subaxillary vertical thoracotomv for common congenital heart diseases is as safe as traditional median sternotomy,without the increasing incidence of postoperative complications.Additionally,compared with traditional median sternotomy,minimally invasive right subaxillary vertical thoracotomv is better in the aspects of hidden incision,appearance,and postoperative recovery.

Effect of Electromagnetic Pulse Exposure on Brain Micro Vascular Permeability in Rats

Objective To observe the effect of electromagnetic pulse (EMP) exposure on cerebral micro vascular permeability in rats. Methods The whole-body of male Sprague-Dawley rats were exposed or sham exposed to 200 pulses or 400 pulses (1 Hz) of EMP at 200 kV/m. At 0.5, 1, 3, 6, and 12 h after EMP exposure, the permeability of cerebral micro vascular was detected by transmission electron microscopy and immunohistochemistry using lanthanum nitrate and endogenous albumin as vascular tracers, respectively. Results The lanthanum nitrate tracer was limited to the micro vascular lumen with no lanthanum nitrate or albumin tracer extravasation in control rat brain. After EMP exposure, the lanthanum nitrate ions reached the tight junction, basal lamina and pericapillary tissue. Similarly, the albumin immunopositive staining was identified in pericapillary tissue. The changes in brain micro vascular permeability were transient, the leakage of micro vascular vessels appeared at 1 h, and reached its peak at 3 h, and nearly recovered at 12 h, after EMP exposure. In addition, the leakage of micro vascular was more obvious after exposure of EMP at 400 pulses than after exposure of EMP at 200 pulses. Conclusion Exposure to 200 and 400 pulses (1 Hz) of EMP at 200 kV/m can increase cerebral micro vascular permeability in rats, which is recoverable.

Cobalt phthalocyanine-graphene complex for electro-catalytic oxidation of dopamine

Cobalt phthalocyanine-graphene （CoPc-Gr） complex are fabricated through 7r-Tr interaction of each components, with CoPc adsorbed/inserted on/in the graphene sheets. The obtained complex could be used in the electro-chemical detection of various medicines. CoPc-Gr modified glassy electrode shows excellent response to the electro-oxidation of dopamine （DA） and ascorbic acid （AA）, much better than those of CoPc, graphene oxide （GrO） or graphene （Gr） modified electrode. Significantly, the detection of dopamine is a diffusion-controlled process, highly selective, and has a low detection limit and broad linear range.

Low-frequency repetitive transcranial magnetic simulation prevents chronic epileptic seizure

Although low-frequency repetitive transcranial magnetic simulation can potentially treat epilepsy, its underlying mechanism remains unclear. This study investigated the influence of low-frequency re-petitive transcranial magnetic simulation on changes in several nonlinear dynamic electroenceph-alographic parameters in rats with chronic epilepsy and explored the mechanism underlying repeti-tive transcranial magnetic simulation-induced antiepileptic effects. An epilepsy model was estab-lished using lithium-pilocarpine intraperitoneal injection into adult Sprague-Dawley rats, which were then treated with repetitive transcranial magnetic simulation for 7 consecutive days. Nonlinear elec-electroencephalographic parameters were obtained from the rats at 7, 14, and 28 days post-stimulation. Results showed significantly lower mean correlation-dimension and Kolmogo-rov-entropy values for stimulated rats than for non-stimulated rats. At 28 days, the complexity and point-wise correlation dimensional values were lower in stimulated rats. Low-frequency repetitive transcranial magnetic simulation has suppressive effects on electrical activity in epileptic rats, thus explaining its effectiveness in treating epilepsy.

Characterization of a full-length infectious clone of bovine foamy virus 3026

The biological features of most foamy viruses(FVs) are poorly understood, including bovine foamy virus(BFV). BFV strain 3026(BFV3026) was isolated from the peripheral blood mononuclear cells of an infected cow in Zhangjiakou, China. A full-length genomic clone of BFV3026 was obtained from BFV3026-infected cells, and it exhibited more than 99% amino acid(AA) homology to another BFV strain isolated in the USA. Upon transfection into fetal canine thymus cells, the full-length BFV3026 clone produced viral structural and auxiliary proteins, typical cytopathic effects, and virus particles. These results demonstrate that the full-length BFV3026 clone is fully infectious and can be used in further BFV3026 research.

Reversible regulation of enzyme-like activity of molybdenum disulfide quantum dots for colorimetric pharmaceutical analysis

Regulating the catalytic activity of nanozymes is significant for their applications in various fields.Here,we demonstrate a new strategy to achieve reversible regulation of the nanozyme’s activity for sensing purpose.This strategy involves the use of zero-dimensional MoS;quantum dots(MQDs)as the building blocks of nanozymes which display very weak peroxidase(POD)-like activity.Interestingly,such POD-like activity of the MQDs largely enhances in the presence of Fe;while diminishes with the addition of captopril thereafter.Further investigations identify the mechanism of Fe;-mediated aggregation-induced enhancement of the POD-like activity and the inhibitory effect of captopril on the enhancement,which is highly dependent on their concentrations.Based on this finding,a colorimetric method for the detection of captopril is developed.This sensing approach exhibits the merits of simplicity,rapidness,reliability,and low cost,which has been successfully applied in quality control of captopril in pharmaceutical products.Moreover,the present sensing platform allows smartphone read-out,which has promising applications in point-of-care testing devices for clinical diagnosis and drug analysis.

The Forest Pattern and Its Variation Characteristics in Economic Zone on the Western Coast of the Taiwan Straits

Taking Economic Zone on the Western Coast of the Taiwan Straits as the study area,we use GIS,remote sensing,mathematical statistics and other methods,to analyze the forest pattern and its variation characteristics in Economic Zone on the Western Coast of the Taiwan Straits during the period 1992-2008;use canonical correspondence analysis(CCA)to examine the effects of environmental factors on changes in forest pattern.The results show that the forest resources are rich in Economic Zone on the Western Coast of the Taiwan Straits,accounting for 61.40% of the total area,but the geographical distribution is very uneven,with obvious regional and elevation gradient difference;since1992,the forest has been dwindling in Economic Zone on the Western Coast of the Taiwan Straits,from 89 300 km2 in 1992 to 88 300 km2 in 2008;in terms of changes in region and elevation gradient,there is obvious difference in the forest,and the central and western forest of Wuyi Mountain tends to decline obviously;the main environmental factors influencing changes in forest pattern in Economic Zone on the Western Coast of the Taiwan Straits include temperature,sunshine hours,GDP per capita and precipitation;evaporation,evaporation and population density have weak effects on changes in forest pattern.

Assessment of Soil Quality of Tidal Marshes in Shanghai City

We take three types of tidal marshes in Shanghai City as the study object:tidal marshes in mainland,tidal marshes in the rim of islands,and shoal in Yangtze estuary.On the basis of assessing nutrient quality and environmental quality,respectively,we use soil quality index(SQI)to assess the soil quality of tidal flats,meanwhile formulate the quality grading standards,and analyze the current situation and characteristics of it.The results show that except the north of Hangzhou Bay,Nanhui and Jiuduansha with low soil nutrient quality,there are not obvious differences in soil nutrient quality between other regions;the heavy metal pollution of tidal marshes in mainland is more serious than that of tidal marshes in the rim of islands;in terms of the comprehensive soil quality index,the regions are sequenced as follows:Jiuduansha wetland>Chongming Dongtan wetland>Nanhui tidal flat>tidal flat on the periphery of Chongming Island>tidal flat on the periphery of Hengsha Island>Pudong tidal flat>Baoshan tidal flat>tidal flat on the periphery of Changxing Island>tidal flat in the north of Hangzhou Bay.Among them,Jiuduansha wetland and Chongming Dongtan wetland have the best soil quality,belonging to class III,followed by Nanhui tidal flat,tidal flat on the periphery of Chongming Island and tidal flat on the periphery of Hengsha Island,belonging to class IV;tidal flat on the periphery of Changxing Island,Pudong tidal flat,Baoshan tidal flat and tidal flat in the north of Hangzhou Bay belong to class V.

Simultaneous and systematic analysis of cellular and viral gene expression during Enterovirus 71-induced host shutoff

Dear Editor, Enteroviruses, including poliovirus, enterovirus 71 (EV71), enterovirus 68, coxsackievirus A16, cause millions of infections every year. The infection can lead to serious human diseases and is a significant public health problem. Among them, EV71 is an emerging pathogen that causes severe hand, foot and mouth disease (HFMD) and neurological disease, especially in young children. Currently, there is no effective treatment to EV71-caused diseases, partially blaming to a lack of understanding EV71 replication mechanism (Solomon et al., 2010). As a member of Picornaviri-dae, EV71 infection induces a rapid induction of host shutoff, which is marked by the inhibition of cellular protein synthesis (Holland, 1963). In the meantime, viral protein synthesis takes over the cellular translational machinery. It is believed that the cellular protein synthesis shutoff benefits viral replication by relocating cellular resources and facilitating viral escape from host cell immune responses (Cao et al., 2017). Both transcription and translation inhibition have been suggested to contribute to the host protein synthesis shutoff during picornavirus infection (Holland, 1963;Belsham, 2009). However, the relative role of transcription and translation inhibition in virus-induced host shutoff is yet elusive.

基于MoS_(2)量子点类过氧化物酶活性调控比色检测地中海贫血症治疗药物去铁酮

纳米酶催化活性的精准调控对其在传感和生物医学等领域的应用具有重要意义.本文以MoS_(2)量子点为研究对象,通过控制其在水溶液中的聚集或分散状态实现了类过氧化物酶活性的可控调节.研究发现,单分散的MoS_(2)量子点表现出十分微弱的类过氧化物酶活性,Fe^(3+)可诱导其发生聚集使粒径增大,导致类过氧化物酶活性显著增强;而地中海贫血症的治疗药物去铁酮能选择性与Fe^(3+)配位,从而抑制MoS2量子点的聚集行为和类酶活性增强,且这种抑制作用与去铁酮的浓度在一定范围内呈比例关系.基于该原理,本文构建了一种比色检测去铁酮的新方法并成功应用于药品中去铁酮的质量控制.借助智能手机的拍照和色度分析功能,本文还开发了利用智能手机作为检测器的便携式分析方法用于去铁酮含量的测定,该方法有望进一步扩展到床边检测与诊断.

Austenite Grain Refinement by Reverse α′→γ Transformation in Metastable Austenitic Manganese Steel

Microstructure of metastable austenitic manganese steel after reverse transformation treatment was investi gated using optical microscopy, X ray diffraction （XRD）, electrical resistivity and hardness testing. Austenite grain refinement was successfully achieved by a two-step heat treatment. First, martensite was produced by cooling the so- lution-treated samples to --196 ℃. Then, the deep cryogenic treated samples were heated to 850 ℃ upon slow or rapid heating. The mean size of original austenite grain was about 400 fire. But the mean size of equiaxed reversion austenite was refined to 50 μm. Microstructure evolution and electrical resistivity change showed that martensite plates underwent tempering action upon slow heating, and the residual austenite was decomposed, resulting in the formation of pearlite nodules at the austenite grains boundaries. The refinement mechanism upon slow heating is the diffusion-controlled nucleation and growth of austenite. However, the reverse transformation upon rapid heating was predominated by displacive manner. The residual austenite was not decomposed. The plate α-phase was carbon-super- saturated until the starting of reverse transformation. The reverse transformation was accompanied by surface effect, resulting in the formation of plate austenite with high density dislocations. The refinement mechanism upon rapid heating is the recrystallization of displacive reversed austenite.

他氟前列素对原发性开角型青光眼和高眼压症患者24小时眼压的影响

目的:通过测量24 h眼压评估他氟前列素对原发性开角型青光眼(POAG)和高眼压症(OHT)患者的临床疗效。方法:系列病例研究。收集2018年1月至2019年3月在沈阳爱尔眼视光医院初次诊断的POAG和OHT患者22例(43眼),由医师对所有患者进行Icare HOME眼压计操作培训及认证,认证合格后使用Goldmann压平眼压计(GAT)测量眼压3次,然后由患者使用Icare HOME眼压计自我监测用药前24 h眼压,之后每天2100给予他氟前列素点眼1次,1个月后患者自我监测用药后24 h眼压。采用单因素方差分析和Bland-Altman分析比较医师使用GAT和患者使用Icare HOME眼压计测量眼压的一致性。采用配对t检验分析患者使用他氟前列素治疗前后各个时间点的眼压值、24 h眼压均值、峰值、谷值和波动值的变化。结果:医师使用GAT和患者使用Icare HOME眼压计测量眼压的平均值分别为(18.2±3.7)mmHg(1 mmHg=0.133 kPa)和(17.4±4.2)mmHg,差异无统计学意义(F=0.837,P=0.363)。Bland-Altman分析证明医师使用GAT和患者使用Icare HOME眼压计测量眼压具有良好的一致性。使用他氟前列素治疗1个月后,所有评估时间点的眼压均降低(均P<0.05),不同时间点眼压降低的范围为1.8~5.5 mmHg。用药前24 h眼压均值、峰值、谷值、波动值分别为(19.4±5.0)、(25.0±5.8)、(14.1±4.5)、(10.9±3.8)mmHg,用药后分别降低至(15.6±4.2)、(20.4±4.5)、(11.3±3.6)、(9.2±2.9)mmHg,差异均有统计学意义(t=9.450、9.636、5.939、3.137,均P<0.05)。结论:对于初次诊断的POAG和OHT患者,他氟前列素可明显降低24 h中所有评估时间点的眼压。

Microstructure Refinement and Property Improvement of Metastable Austenitic Manganese Steel Induced by Electropulsing

Grain refinement efficiency of electropulsing treatment （EPT） for metastable austenitic manganese steel was investigated. The mean grain size of original austenite is 300 ptm. However, after EPT, the microstructure ex hibits a bimodal grain size distribution, and nearly 70vol. % grains are less than 60 /Lm. The refined austenite results in ultrafine martensitic microstrncture. The tensile strengths of refined austenitic and martensitic microstructures were improved from 495 to 670, and 794 to 900 MPa respectively. The fine grained materials possess better fracture toughness. The work hardening capacity and wear resistance of the refined austenitic microstructure are improved. The reasonable mechanism of grain refinement is the combination of accelerating new phase nucleation and restraining the growth of neonatal austenitic grain during reverse transformation and rapid recrystallization induced by electropulsing.

Bacterial community response to petroleum contamination in brackish tidal marsh sediments in the Yangtze River Estuary, China

The brackish tidal marsh in the Baimaosha area of the Yangtze River Estuary was severely contaminated by 400 tons of heavy crude petroleum from a tanker that sank in December 2012.The spill accident led to severe environmental damage owing to its high toxicity,persistence and wide distribution.Microbial communities play vital roles in petroleum degradation in marsh sediments.Therefore,taxonomic analysis,high-throughput sequencing and 16 S rRNA functional prediction were used to analyze the structure and function of microbial communities among uncontaminated(CK),lightly polluted(LP),heavily polluted(HP),and treated(TD)sediments.The bacterial communities responded with increased richness and decreased diversity when exposed to petroleum contamination.The dominant class changed from Deltaproteobacteria to Gammaproteobacteria after petroleum contamination.The phylum Firmicutes increased dramatically in oil-enriched sediment by 75.78%,346.19%and 267.26%in LP,HP and TD,respectively.One of the suspected oil-degrading genera,Dechloromonas,increased the most in oil-contaminated sediment,by 540.54%,711.27%and 656.78%in LP,HP and TD,respectively.Spore protease,quinate dehydrogenase(quinone)and glutathione-independent formaldehyde dehydrogenase,three types of identified enzymes,increased enormously with the increasing petroleum concentration.In conclusion,petroleum contamination altered the community composition and microorganism structure,and promoted some bacteria to produce the corresponding degrading enzymes.Additionally,the suspected petroleum-degrading genera should be considered when restoring oil-contaminated sediment.

HIV-1 Vpr protein activates the NF-κB pathway to promote G2/M cell cycle arrest

Viral protein R(Vpr) plays an important role in the replication and pathogenesis of Human immunodeficiency virus type 1(HIV-1). Some of the various functions attributed to Vpr, including the induction of G2/M cell cycle arrest, activating the NF-κB pathway, and promoting viral reverse transcription, might be interrelated. To test this hypothesis, a panel of Vpr mutants were investigated for their ability to induce G2/M arrest and to activate the NF-κB pathway. The results showed that the Vpr mutants that failed to activate NF-κB also lost the activity to induce G2/M arrest, which suggests that inducing G2/M arrest via Vpr depends at least partially on the activation of NF-κB. This latter possibility is supported by data showing that knocking down the key factors in the NF-κB pathway – p65, Rel B, IKKα, or IKKβ– partially rescued the G2/M arrest induced by Vpr.Our results suggest that the NF-κB pathway is probably involved in Vpr-induced G2/M cell cycle arrest.

Bombyx mori U-shaped regulates the melanization cascade and immune response via binding with the Lozenge protein

Zinc finger protein,an important transcription factor,regulates gene expression associated with various physiological and pathological processes.U-shaped,belong to the Friend of GATA(FOG)transcription factor,plays a crucial role in hematopoiesis by interacting with the GATA transcription factor as a co-factor.However,little is known about its functions in insects.In the present study,a U-shaped cDNA was identified and characterized from the silkworm Bombyx mori and its potential roles in innate immunity investigated.The predicted silkworm U-shaped amino acid sequence contained a classical nuclear localization signal(NLS)motif“GESSPKRRRR”at position 45CU459,and arginine residues at position 456 and 478 are the critical sites of the NLS.U-shaped mRNA was detected in all tested tissues of the B.mori;however,the highest levels were found in the hemocytes.U-shaped mRNA expression levels were upregulated in the hemocyte after the Escherichia coli and Staphylococcus aureus challenge.Furthermore,U-shaped knockdown significantly reduced the melanization process and suppressed the expression of melanization-associated genes,including PPO1,PPO2,PPAE and BAEE.In addition,U-shaped interacts with Lozenge protein to regulate the innate immune response of the insect.Our results revealed that U-shaped binds directly to Lozenge protein to modulate the melanization process and innate immune responses in silkworm.

Lysine residues K66, K109, and K110 in the bovine foamy virus transactivator protein are required for transactivation and viral replication

Bovine foamy virus(BFV) is a complex retrovirus that infects cattle. Like all retroviruses, BFV encodes a transactivator Tas protein(BTas) that increases gene transcription from viral promoters.BFV encodes two promoters that can interact with BTas, a conserved promoter in the 5' long terminal repeat(LTR) and a unique internal promoter(IP). Our previous study showed that BTas is acetylated by p300 at residues K66, K109, and K110, which markedly enhanced the ability of BTas to bind to DNA. However, whether these residues are important for BFV replication was not determined. Therefore, in this study we provide direct evidence that BTas is required for BFV replication and demonstrate that residues K66, K109, and K110 are critical for BTas function and BFV replication. Full-length infectious clones were generated, which were BTas deficient or contained lysine to arginine(K→R) mutations at position 66, 109, and/or 110. In vivo data indicated that K→R mutations at positions 66, 109, and 110 in BTas impaired transactivation of both the LTR and IP promoters. In addition, the K→R mutations in full-length infectious clones reduced expression of viral proteins, and the triple mutant and BTas deletion completely abrogated viral replication. Taken together, these results indicate that lysine residues at positions 66, 109, and 110 in the BTas protein are crucial for BFV replication and suggest a potential role for BTas acetylation in regulating the viral life cycle.