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| 1 | Hypoxic preconditioning stimulates angiogenesis in ischemic penumbra after acute cerebral infarction显示文摘Previous studies have demonstrated the protective effect of hypoxic preconditioning on acute cerebral infarction,but the mechanisms underlying this protection remain unclear.To investigate the protective mechanisms of hypoxic preconditioning in relation to its effects on angiogenesis,we induced a photochemical model of cerebral infarction in an inbred line of mice(BALB/c).Mice were then exposed to hypoxic preconditioning 30 minutes prior to model establishment.Results showed significantly increased vascular endothelial growth factor and CD31 expression in the ischemic penumbra at 24 and 72 hours post infarction,mainly in neurons and vascular endothelial cells.Hypoxic preconditioning increased vascular endothelial growth factor and CD31 expression in the ischemic penumbra and the expression of vascular endothelial growth factor was positively related to that of CD31.Moreover,hypoxic preconditioning reduced the infarct volume and improved neurological function in mice.These findings indicate that the protective role of hypoxic preconditioning in acute cerebral infarction may possibly be due to an increase in expression of vascular endothelial growth factor and CD31 in the ischemic penumbra,which promoted angiogenesis. | Sijie Li Yanbo Zhang Guo Shao Mingfeng Yang Jingzhong Niu Guowei Lv Xunming Ji | 2013 | Neural Regeneration Research2013，8，31： | 31 |
| 2 | Temperature variation of a thermionic cathode during electron emission显示文摘It is necessary to know the actual temperature of a thermionic cathode that works as the electron source in a microwave tube. It has been found that the temperature of the cathode drops markedly during the thermionic emission. For example, the temperature could fall by about 30oC under a current density of 2.92 A/cm2. Using the molecular thermodynamics, the dependence of the cathode temperature on the emission current density has been obtained. It has been theoretically pointed out that several factors, such as heating model and temperature coefficient of resis-tance of heater, can influence the cathode temperature. These theoretical conclu-sions were supported by the experimental results. | LIU YanWen TIAN Hong HAN Yong XU ZhenYing MENG MingFeng ZHANG HongLai | 2008 | Science China(Technological Sciences)2008，51，9： | 22 |
| 3 | Genome-wide identification, expression analysis of auxin-responsive GH_3 family genes in maize(Zea mays L.) under abiotic stresses显示文摘Auxin is involved in different aspects of plant growth and development by regulating the expression of auxinresponsive family genes. As one of the three major auxinresponsive families, GH3(Gretchen Hagen3) genes participate in auxin homeostasis by catalyzing auxin conjugation and bounding free indole-3-acetic acid(IAA) to amino acids.However, how GH3 genes function in responses to abiotic stresses and various hormones in maize is largely unknown.Here, the latest updated maize(Zea mays L.) reference genome sequence was used to characterize and analyze the Zm GH3 family genes from maize. The results showed that 13 Zm GH3 genes were mapped on fi ve maize chromosomes(total10 chromosomes). Highly diversi fi ed gene structures and tissue-speci fi c expression patterns suggested the possibility of function diversi fi cation for these genes in response to environmental stresses and hormone stimuli. The expression patterns of Zm GH3 genes are responsive to several abiotic stresses(salt, drought and cadmium) and major stress-relatedhormones(abscisic acid, salicylic acid and jasmonic acid)Various environmental factors suppress auxin free IAA contents in maize roots suggesting that these abiotic stresses and hormones might alter GH3-mediated auxin levels. The respon siveness of Zm GH3 genes to a wide range of abiotic stresses and stress-related hormones suggested that Zm GH3 s are involved in maize tolerance to environmental stresses. | Shangguo Feng Runqing Yue Sun Tao Yanjun Yang Lei Zhang Mingfeng Xu Huizhong Wang Chenjia Shen | 2015 | Journal of Integrative Plant Biology2015，57，9： | 17 |
| 4 | PTEN and Ki67 expression is associated with clinicopathologic features of non-small cell lung cancer显示文摘Phosphatase and tensin homolog deleted on chromosome 10(PTEN) and the proliferating antigen Ki67 have been widely studied in several tumors.However,their role as indicator in non-small cell lung cancer(NSCLC)remains unknown.Here,we investigated the expression of PTEN and Ki67 in NSCLC tissues and paired normal lung tissues to identify whether these proteins are associated with lung cancer development and survival.Immunohistochemistry for PTEN and Ki67 was performed on 67 lung cancer tissues and 41 paired adjacent normal lung tissues to detect the expression of these two proteins.The expression of PTEN in NSCLC tissues(32.8%) was significantly lower than that in normal tissues(82.9%,P < 0.05).In contrast,the expression of Ki67 in NSCLC tissues(76.1%) was significantly higher than that in normal tissues(27.3%,P < 0.05).Expression of both PTEN and Ki67 were strongly associated with tumor histology,clinical stage,lymph node metastasis,differentiation and4-year postoperative survival rate(P < 0.05).However,PTEN expression was negatively correlated with Ki67 expression(r =-0.279,P < 0.05).In conclusion,low PTEN expression and Ki67 overexpression are associated with malignant invasion and lymph node metastasis of NSCLC.These proteins may serve as diagnostic and prognostic biomarkers of NSCLC. | Yong Ji Mingfeng Zheng Shugao Ye Jingyu Chen Yijiang Chen | 2014 | The Journal of Biomedical Research2014，28，6： | 16 |
| 5 | Spin-decoupled metasurface for simultaneous detection of spin and orbital angular momenta via momentum transformation显示文摘With inherent orthogonality,both the spin angular momentum(SAM)and orbital angular momentum(OAM)of photons have been utilized to expand the dimensions of quantum information,optical communications,and information processing,wherein simultaneous detection of SAMs and OAMs with a single element and a single-shot measurement is highly anticipated.Here,a single azimuthal-quadratic phase metasurface-based photonic momentum transformation(PMT)is illustrated and utilized for vortex recognition.Since different vortices are converted into focusing patterns with distinct azimuthal coordinates on a transverse plane through PMT,OAMs within a large mode space can be determined through a single-shot measurement.Moreover,spin-controlled dual-functional PMTs are proposed for simultaneous SAM and OAM sorting,which is implemented by a single spin-decoupled metasurface that merges both the geometric phase and dynamic phase.Interestingly,our proposed method can detect vectorial vortices with both phase and polarization singularities,as well as superimposed vortices with a certain interval step.Experimental results obtained at several wavelengths in the visible band exhibit good agreement with the numerical modeling.With the merits of ultracompact device size,simple optical configuration,and prominent vortex recognition ability,our approach may underpin the development of integrated and high-dimensional optical and quantum systems. | Yinghui Guo Shicong Zhang Mingbo Pu Qiong He Jinjin Jin Mingfeng Xu Yaxin Zhang Ping Gao Xiangang Luo | 2021 | Light(Science & Applications)2021，10，4： | 14 |
| 6 | Investigation on the catalytic effects of AAEM during steam gasification and the resultant char reactivity in oxygen using Shengli lignite at different forms显示文摘 | Jianxin Mi Ningbo Wang Mingfeng Wang Pengju Huo Dan Liu | 2015 | International Journal of Coal Science & Technology2015，2，3： | 14 |
| 7 | Gabapentin inhibits central sensitization during migraine显示文摘Peripheral and central sensitizations are phenomena that occur during migraine.The role of gabapentin,a migraine preventive drug,on central sensitization remains unclear.In this study,a rat model of migraine was established by electrical stimulation of the trigeminal ganglion,and the animals were given intragastric gabapentin.Changes in amino acid content in the cerebrospinal fluid and protein kinase C membrane translocation in the spinal trigeminal nucleus were examined to clarify the mechanisms underlying the efficacy of gabapentin in the treatment of central sensitization during migraine.Electrophysiology,liquid chromatography-mass spectrometry and western blot analysis results revealed that gabapentin reduces neuronal excitability in the spinal nucleus in the trigeminal nerve,decreases excitatory amino acid content and inhibits the activation of protein kinase C.This provides evidence that excitatory amino acids and protein kinase C are involved in the formation and maintenance of central sensitization during migraine.Gabapentin inhibits migraine by reducing excitatory amino acid content in the cerebrospinal fluid and inhibiting protein kinase C activation. | Yanbo Zhang Guo Shao Wei Zhang Sijie Li Jingzhong Niu Dongmei Hu Mingfeng Yang Xunming Ji | 2013 | Neural Regeneration Research2013，8，32： | 12 |
| 8 | Serpentinization, abiogenic organic compounds, and deep life显示文摘The hydrocarbons and other organic compounds generated through abiogenic or inorganic processes are closely related to two science subjects,i.e.,energy resources and life’s origin and evolution.'The earth’s primordial abiogenic hydrocarbon theory'and'the serpentinization of abiogenic hydrocarbon theory'are the two mainstream theories in the field of related studies.Serpentinization generally occurs in slow expanding mid-ocean ridges and continental ophiolites tectonic environment,etc.The abiogenic hydrocarbons and other organic compounds formed through the serpentinization of ultramafic rocks provide energy and raw materials to support chemosynthetic microbial communities,which probably was the most important hydration reaction for the origin and early evolution of life.The superposition of biological and abiological processes creates big challenge to the identification of the abiogenic organic materials in serpentinite-hosted ecosystem.Whether abiotic(inorganic)process can form oil and gas resource is a difficult question that has been explored continuously by scientific community for more than a century but has not yet been solved.However,some important progress has been made.The prospecting practice of abiogenic hydrocarbons in commercial gases from the Songliao Basin,China,provides an important example for exploring abiogenic natural gas resources. | WANG XianBin OUYANG ZiYuan ZHUO ShengGuang ZHANG MingFeng ZHENG GuoDong WANG YongLi | 2014 | Science China Earth Sciences2014，57，5： | 11 |
| 9 | Daily variation characteristics of CO2 emission fluxes and contributions of environmental factors in semiarid grassland of Inner Mongolia, China显示文摘Fixed field experimental studies are carried out on daily variations of the undis- turbed community and soil respiration fluxes in different phenological phases of 2001―2002 in semiarid Aneurolepidium chinense steppe of Inner Mongolia, China using static black chamber method. Corresponding statistical analysis of the contributions of the water-heat factors (air temperature, ground temperature, surface soil water content) and ecological factors (above- ground biomass, underground biomass, litter biomass) to daily variation law of the undisturbed community and soil respiration fluxes as well as differences in daily respiration are also con- ducted. The results indicate that undisturbed community and soil respiration have apparent daily variation laws, daily variation patterns of respiration fluxes during different phenological phases are basically the same, and the variations of environmental factors only exert effect on CO2 emission intensities, while the effect on daily variation pattern of grassland CO2 emission fluxes is relatively small. The daily total respiration of the undisturbed community in different phenological phases ranges from 1.34―10.13 g·m?2; soil daily total respiration ranges from 0.98―5.17 g·m?2; both daily variations of undisturbed community and soil respiration fluxes are significantly corre- lated (p < 0.05) or extremely significantly correlated (p < 0.01) with air temperatures and ground surface temperatures, but the correlativity with the soil temperature at 5 and 10 cm depths is relatively weak; multiple regression analysis indicates that about 80% of the difference in daily respiration of the undisturbed community among different phenological phases is induced by the variation of the aboveground biomass, while the variations of the remaining factors can jointly explain around 20% of the daily respiration variations of the whole grassland ecosystem; about 83% of the soil daily respiration variation of the different phenological phases is caused by 0―20 cm underground biomass. Besides, surface soil water content is also an important environmental factor affecting soil daily respiration variations of the Aneurolepidium chinense steppe, but its partial correlation coefficient with soil daily respiration amount does not reach the significance level of 0.05. | QI Yuchun DONG Yunshe LIU Jiyuan GENG Yuanbo LI Mingfeng YANG Xiaohong LIU Lixin | 2005 | Science China Earth Sciences2005，48，7： | 11 |
| 10 | Effects of miR-219/miR-338 on microglia and astrocyte behaviors and astrocyte-oligodendrocyte precursor cell interactions显示文摘MiR-219 and miR-338(miR-219/miR-338)are oligodendrocyte-specific microRNAs.The overexpression of these miRs in oligodendrocyte precursor cells promotes their differentiation and maturation into oligodendrocytes,which may enhance axonal remyelination after nerve injuries in the central nervous system(CNS).As such,the delivery of miR-219/miR-338 to the CNS to promote oligodendrocyte precursor cell differentiation,maturation and myelination could be a promising approach for nerve repair.However,nerve injuries in the CNS also involve other cell types,such as microglia and astrocytes.Herein,we investigated the effects of miR-219/miR-338 treatment on microglia and astrocytes in vitro and in vivo.We found that miR-219/miR-338 diminished microglial expression of pro-inflammatory cytokines and suppressed astrocyte activation.In addition,we showed that miR-219/miR-338 enhanced oligodendrocyte precursor cell differentiation and maturation in a scratch assay paradigm that re-created a nerve injury condition in vitro.Collectively,our results suggest miR-219/miR-338 as a promising treatment for axonal remyelination in the CNS following nerve injuries.All experimental procedures were approved by the Institutional Animal Care and Use Committee(IACUC),Nanyang Technological University(approval No.A0309 and A0333)on April 27,2016 and October 8,2016. | Lan Huong Nguyen William Ong Kai Wang Mingfeng Wang Dean Nizetic Sing Yian Chew | 2020 | Neural Regeneration Research2020，15，4： | 11 |
| 11 | Acute calculous cholecystitis associated with hepatic artery pseudoaneurysm after percutaneous transhepatic gallbladder drainage in a diabetic patient显示文摘Patients with acute calculous cholecystitis are usually undertaken surgery laparoscopic cholecystectomy.However,there are controversies about the decision of operation for patients with high risk factors.Percutaneous transhepatic gallbladder drainage (PTGD) is palliative therapy to alleviate symptoms and physical signs.Since improved clinical outcome has been observed for PTGD,it was recommended as an initial therapeutic option for high risk patients who might need surgery.1 Percutaneous drainage in acute calculous cholecystitis for high risk patients is to be a safe and successful treatment option for patients less eligible for surgery.2 PTGD is relatively safe,but has certain complications.We provided a case report of acute calculous cholecystitis associated with hepatic artery pseudoaneurysm after PTGD in a diabetes mellitus patient.The liver vascular pseudoaneurysms and secondary changes of liver were documented by the imaging examination.The complex interactions among inflammation,bleeding,and diabetes mellitus were involved in this case. | Tian Hu Xia Mingfeng Zhang Shuai Li Jie Liu Ju | 2014 | Chinese Medical Journal2014，，17： | 9 |
| 12 | Design of the Metal Precursors Molecular Structures in Impregnating Solutions for Preparation of Efficient Ni Mo/Al_2O_3 Hydrodesulfurization Catalysts显示文摘The molecular structures of metal precursors in the impregnating solution were designed so as to prepare efficient Ni Mo/Al_2O_3 hydrodesulfurization(HDS) catalysts. At first, five typical impregnating solutions were designed; the existing metal precursors, such as [Mo4(citrate)2O11]^(4-)-like, [P2Mo18O62]^(6-)-like and [P2Mo5O23]^(6-)-like species in the solutions were confirmed by laser Raman spectroscopy(LRS). The UV-Vis spectra results indicated that the solutions containing both phosphoric acid and citric acid could change the existing form of nickel species. Five corresponding Ni Mo/Al_2O_3 catalysts were prepared by the incipient wetness impregnation method. The LRS analysis results of dried catalysts showed that the above metal precursors could be partly retained on alumina support after impregnation and drying, although the interface reaction between different metal precursors and alumina support unavoidably took place. Then the catalysts were sulfided and characterized by N2 physisorption, TEM and XPS analyses. The results showed that different metal precursors in impregnating solution could mainly result in the difference in both the morphology of(Ni)Mo S2 slabs and the promoting effect of Ni species. The catalyst prepared mainly with [P2Mo5O23]^(6-)-like species used as precursors exhibited worse dispersion of(Ni)Mo S2 slabs and lower ratio of Ni–Mo–S active phases than the one with [Mo4(citrate)2O11]^(4-)-like species. Promisingly, the catalyst prepared with co-existing [Mo4(citrate)2O11]^(4-)-like, [P2Mo18O62]^(6-)-like and [P2Mo5O23]^(6-)-like species showed better hydrodesulfurization activity for 4,6-DMDBT thanks to its more well-dispersed Ni–Mo–S active phases. | Li Huifeng Li Mingfeng Chu Yang Liu Feng Nie Hong | 2015 | China Petroleum Processing & Petrochemical Technology2015，17，4： | 8 |
| 13 | Crosstalk-free achromatic full Stokes imaging polarimetry metasurface enabled by polarization-dependent phase optimization显示文摘Imaging polarimetry is one of the most widely used analytical technologies for object detection and analysis.To date,most metasurface-based polarimetry techniques are severely limited by narrow operating bandwidths and inevitable crosstalk,leading to detrimental effects on imaging quality and measurement accuracy.Here,we propose a crosstalkfree broadband achromatic full Stokes imaging polarimeter consisting of polarization-sensitive dielectric metalenses,implemented by the principle of polarization-dependent phase optimization.Compared with the single-polarization optimization method,the average crosstalk has been reduced over three times under incident light with arbitrary polarization ranging from 9μm to 12μm,which guarantees the measurement of the polarization state more precisely.The experimental results indicate that the designed polarization-sensitive metalenses can effectively eliminate the chromatic aberration with polarization selectivity and negligible crosstalk.The measured average relative errors are 7.08%,8.62%,7.15%,and 7.59%at 9.3,9.6,10.3,and 10.6μm,respectively.Simultaneously,the broadband full polarization imaging capability of the device is also verified.This work is expected to have potential applications in wavefront detection,remote sensing,light-field imaging,and so forth. | Yaxin Zhang Mingbo Pu Jinjin Jin Xinjian Lu Yinghui Guo Jixiang Cai Fei Zhang Yingli Ha Qiong He Mingfeng Xu Xiong Li Xiaoliang Ma Xiangang Luo | 2022 | Opto-Electronic Advances2022，5，11： | 6 |
| 14 | Angle Dependence Analysis Method to Determine SNRArc Applied to GNSSMRSea Level Retrieval显示文摘The Global Navigation Satellite Systems(GNSS)broadcast radio signals are continuously at two or more frequencies in the L-band,and the multipath signals from sea surface recorded by off-the-shelf geodetic receivers have been demonstrated they can be used to estimate sea level,using a technology called GNSS multipath reflectometry(GNSS-MR).Before proceeding to estimate reflection parameters,the azimuth range and elevation angle range are needed to be defined,as only with suitable azimuths and elevation angles the sensing zones can be guaranteed on water.So,this study presents an angle dependence analysis method to jointly select the azimuth range and elevation angle range based on wavelet analysis which can describe the nonstationary power of different sinusoidal oscillations changed with elevation angle.The key of this method is to use one grid model to screen the spectrum power of multipath oscillation on different elevation angles and azimuths in this work.Then the elevation angles and the azimuths can be determined by searching grids with greater power.The GPS and GLONASS data of two MultiGNSS Experiment(MGEX)stations named BRST and MAYG was analyzed and used to retrieve.Firstly,the angle dependence analysis was carried out to determine the elevation range and azimuth range.Secondly,the sea levels were retrieved from individual signals.Finally,the retrievals of individual signals are combined to form a 10-min sea level retrieval series.The RMSEs of the combined retrievals are both less than 15 cm.The results show the effectiveness of the selection of angle range based on the angle dependence analysis method. | Xiaolei WANG Xiufeng HE Qin ZHANG Mingfeng SONG Zijin NIU | 2021 | Journal of Geodesy and Geoinformation Science2021，4，2： | 6 |
| 15 | Development and CommercialApplication of RSDS-II Technology for Selective Hydrodesulfurization of FCC Naphtha显示文摘The FCC naphtha selective hydrodesulfurization technology(RSDS-II)has been tested with different feedstocks in pilot scale.The results show that RSDS-II technology is viable in terms of its adaptability to different feedstocks.To produce gasoline with a sulfur content of less than 50μg/g by the RSDS-II technology,the gasoline RON loss is less than 1.8,0.9and 0.2 units,respectively,upon processing the conventional high-sulfur and high-olefin FCC naphtha,the high-sulfur MIP naphtha,and the medium-sulfur or low-sulfur MIP naphtha.Upon using the naphtha produced from pre-hydrotreated FCC feedstock as the RSDS-II feedstock to manufacture gasoline with a sulfur content of lower than 10μg/g,the RON loss does not exceed 1.0 unit.The RSDS-II technology has been commercialized successfully at many refineries.The result of operating commercial RSDS-II unit at the Shanghai Petrochemical Company has revealed that upon processing a feedstock containing 38.7 v% —43.3 v% of olefins and 250—470 mg/g of sulfur,the sulfur content in the treated gasoline ranges from 33μg/g to 46μg/g and the RON loss is equal to only 0.3—0.6 units.Till now this RSDS-II unit has been operating smoothly over 30 months.Thanks to its high HDS activity and good selectivity,the RSDS-II technology can meet the refinery’s needs for adequate upgrading of gasoline. | Qu Jinhua Xi Yuanbing Li Mingfeng Pan Guangcheng Jin Xin Gao Xiaodong Nie Hong | 2013 | China Petroleum Processing & Petrochemical Technology2013，15，3： | 6 |
| 16 | Cooperation of PprI and DrRRA in response to extreme ionizing radiation in Deinococcus radiodurans显示文摘Deinococcus radiodurans possesses extreme resistance to ionizing radiation,and has been engineered for the remediation of toxic components in radioactive environments.We have previously shown that PprI(also named IrrE)and DrRRA are essential for the DNA protection and repair pathways that respond to ionizing radiation stress in this species.Here,we investigated the combined roles of PprI and DrRRA in resistance to gamma radiation(800 Gy).The double mutant,△drRRA△pprI,was more sensitive to gamma rays than either△drRRA or△pprI single mutants,and exhibited an elevated level of intracellular protein carbonylation,an extended delay in genome reconstitution and reduced transcriptional levels of certain DNA protection and repair proteins,such as kat,sod,recA and pprA.Interestingly,the induction of DrRRA by ionizing radiation was partially inhibited by the deletion of pprI. Taken together,these results suggest that DrRRA and PprI might have collaborative roles in the response of D.radiodurans to extreme ionizing radiation. | WANG LiangYan YIN LongFei XU GuangZhi LI MingFeng ZHANG Hui TIAN Bin HUA YueJin | 2012 | Chinese Science Bulletin2012，57，1： | 6 |
| 17 | Decadal co-variability of the summer surface air temperature and soil moisture in China under global warming显示文摘The self-calibrating Palmer Drought Severity Index (PDSI) is calculated using newly updated ground observations of monthly surface air temperature (SAT) and precipitation in China. The co-variabilities of PDSI and SAT are examined for summer for the period 1961-2004. The results show that there exist decadal climate co-variabilities and strong nonlinear interactions between SAT and soil moisture in many regions of China. Some of the co-variabilities can be linked to global warming. In summer,sig-nificant decadal co-variabilities from cool-wet to warm-dry conditions are found in the east region of Northwest China,North China,and Northeast China. An important finding is that in the west region of Northwest China and Southeast China,pronounced decadal co-variabilities take place from warm-dry to cool-wet conditions. Because significant warming was observed over most areas of the global land surface during the past 20-30 years,the shift to cool-wet conditions is a unique phenomenon which may deserve much scientific attention. The nonlinear interactions between SAT and soil moisture may partly account for the observed decadal co-variabilities. It is shown that anomalies of SAT will greatly affect the climatic co-variabilities,and changes of SAT may bring notable influence on the PDSI in China. These results provide observational evidence for increasing risks of decadal drought and wet-ness as anthropogenic global warming progresses. | SU MingFeng WANG HuiJun | 2007 | Chinese Science Bulletin2007，52，11： | 5 |
| 18 | Development of New Generation Catalysts for Selective Hydrodesulfurization of FCC Naphtha显示文摘The influence of active metal components of catalyst, additives and catalyst preparation method on the reactivity of catalyst for selective hydrodesulfurization (HDS) of FCC naphtha was investigated, and the RSDS-21 catalyst with high HDS performance and the RSDS-22 catalyst with high selectivity were developed by RIPP. The composite loading of a new series of catalysts for selective HDS of FCC gasoline has demonstrated excellent desulfurization activity and selectivity and can under conventional hydrotreating conditions manufacture clean gasoline product meeting the national IV emission standard and the Euro V emission standard with less loss in antiknock index. The finalized new series of FCC catalysts upon being adopted for selective HDS of FCC naphtha have good adaptability to different feedstocks along with good stability. | Chu Yang Li Mingfeng Li Huifeng Qu Jinhua Nie Hong Li Dadong (Research Institute of Petroleum Processing, SINOPEC Corp., Beijing 100083) | 2009 | China Petroleum Processing & Petrochemical Technology2009，11，1： | 5 |
| 19 | Development and Application of Hydrocracking Catalysts RHC-1/RHC-5 for Maximizing High Quality Chemical Raw Materials Yield显示文摘To adapt to the change in the demand of the oil refining market,two hydrocracking catalysts,RHC-1 and RHC-5,were developed to improve the quality of tail oil.The catalysts were designed based on the theory of selective ring-opening.By selecting more acidic molecular sieves,the problem of poor selectivity of conventional materials can be solved to properly match up to the hydrogenation performance of catalysts.Compared with the performance of previous catalysts,the quality of the tail oil achieved by the said catalysts is better,and the BMCI is reduced by 1—2 units.In the long cycle operation of the petroleum industry,the good quality of the tail oil has been verified and the adaptability of the process conditions is good.When the RHC-1 catalyst is used to process heavy feed under medium pressure,a BMCI value of about12 can be obtained along with a nearly 60%yield of tail oil.The total yield of chemical raw material(steaming cracking feed+catalytic reforming feed)can exceed 80%,and the hydrogen consumption has dropped by nearly 50%as compared to the conventional hydrocracking conversion rate.When processing a mixed CGO and VGO feed with the full conversion mode under a hydrogen pressure of 13.0 MPa,the RHC-5 catalyst can yield about 68.4%of heavy naphtha with a potential aromatic content of up to 50.6,while the total yield of chemical raw materials can reach more than 98%.The results of industrial application of these catalysts show that more than 30%of high quality tail oil can be obtained via processing of inferior quality feed,and its BMCI value can reach 10.7.The total yield of chemical raw materials can reach more than65%.The industrial operation process has implemented two operating cycles totaling 8 years. | Mao Yichao Nie Hong Li Mingfeng Hu Zhihai Zhao Guangle Zhao Yang | 2018 | China Petroleum Processing & Petrochemical Technology2018，20，2： | 5 |
| 20 | Discrimination of False Negative Results in RT-PCR Detection of SARS-CoV-2 RNAs in Clinical Specimens by Using an Internal Reference显示文摘Reverse transcription-polymerase chain reaction(RT-PCR)is an essential method for specific diagnosis of SARS-CoV-2 infection.Unfortunately,false negative test results are often reported.In this study,we attempted to determine the principal causes leading to false negative results of RT-PCR detection of SARS-CoV-2 RNAs in respiratory tract specimens.Multiple sputum and throat swab specimens from 161 confirmed COVID-19 patients were tested with a commercialfluorescent RT-PCR kit targeting the ORF1 ab and N regions of SARS-CoV-2 genome.The RNA level of a cellular housekeeping gene ribonuclease P/MRP subunit p30(RPP30)in these specimens was also assessed by RT-PCR.Data for a total of 1052 samples were retrospectively re-analyzed and a strong association between positive results in SARS-CoV-2 RNA tests and high level of RPP30 RNA in respiratory tract specimens was revealed.By using the ROC-AUC analysis,we identified Ct cutoff values for RPP30 RT-PCR which predicted false negative results for SARS-CoV-2 RT-PCR with high sensitivity(95.03%–95.26%)and specificity(83.72%–98.55%)for respective combination of specimen type and ampli-fication reaction.Using these Ct cutoff values,false negative results could be reliably identified.Therefore,the presence of cellular materials,likely infected host cells,are essential for correct SARS-CoV-2 RNA detection by RT-PCR in patient specimens.RPP30 could serve as an indicator for cellular content,or a surrogate indicator for specimen quality.In addition,our results demonstrated that false negativity accounted for a vast majority of contradicting results in SARS-CoV-2 RNA test by RT-PCR. | Yafei Zhang Changtai Wang Mingfeng Han Jun Ye Yong Gao Zhongping Liu Tengfei He Tuantuan Li Mengyuan Xu Luping Zhou Guizhou Zou Mengji Lu Zhenhua Zhang | 2020 | Virologica Sinica2020，35，6： | 5 |
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