Gas hydrate(GH)is an unconventional resource estimated at 1000-120,000 trillion m^(3)worldwide.Research on GH is ongoing to determine its geological and flow characteristics for commercial produc-tion.After two large-...Gas hydrate(GH)is an unconventional resource estimated at 1000-120,000 trillion m^(3)worldwide.Research on GH is ongoing to determine its geological and flow characteristics for commercial produc-tion.After two large-scale drilling expeditions to study the GH-bearing zone in the Ulleung Basin,the mineral composition of 488 sediment samples was analyzed using X-ray diffraction(XRD).Because the analysis is costly and dependent on experts,a machine learning model was developed to predict the mineral composition using XRD intensity profiles as input data.However,the model’s performance was limited because of improper preprocessing of the intensity profile.Because preprocessing was applied to each feature,the intensity trend was not preserved even though this factor is the most important when analyzing mineral composition.In this study,the profile was preprocessed for each sample using min-max scaling because relative intensity is critical for mineral analysis.For 49 test data among the 488 data,the convolutional neural network(CNN)model improved the average absolute error and coefficient of determination by 41%and 46%,respectively,than those of CNN model with feature-based pre-processing.This study confirms that combining preprocessing for each sample with CNN is the most efficient approach for analyzing XRD data.The developed model can be used for the compositional analysis of sediment samples from the Ulleung Basin and the Korea Plateau.In addition,the overall procedure can be applied to any XRD data of sediments worldwide.展开更多
Metastable β-Ti alloys exhibiting twinning-induced plasticity (TWIP) and transformation-induced plasticity (TRIP) generally have excellent ductility, but typically at the expense of relatively low yield strengths whi...Metastable β-Ti alloys exhibiting twinning-induced plasticity (TWIP) and transformation-induced plasticity (TRIP) generally have excellent ductility, but typically at the expense of relatively low yield strengths which has restricted their widespread use. Our work shows that interstitial oxygen can be employed to regulate β phase stability to significantly enhance both strength and ductility of TWIP/TRIP alloys. For a Ti-32Nb wt.% base alloy, inclusion of 0.3 wt.% O enhanced ductility by more than 140 %, reaching up to 54 % strain, and improved the tensile yield strength by over 95 % to 632 MPa. Compared to other common engineering alloys such as Ti-45Nb, elongation was increased by 29 %, and the yield strength increased by 182 MPa, respectively. Here, we elucidate on impacts of oxygen doping on TWIP/TRIP behaviors in the Ti-32Nb alloy. We reveal that oxygen regulates the critical stress for martensitic transformation, twinning, and dislocation slip. At lower oxygen doping concentrations (≤0.3 wt.% O), multi-stage martensitic transformation and martensitic twinning resulted in high ductility. In higher oxygen content alloys (≥0.5 wt.% O), deformation occurred initially via twinning, while strain induced martensite was subsequently induced in retained β phase regions. Oxygen concentrations control the deformation mechanisms, providing a flexible means to synergistically balance an alloy's strength and ductility. The use of oxygen to enhance stability of the β phase and regulate deformation behaviors is a promising new approach for creating high-performance TWIP/TRIP metastable β-Ti alloys with outstanding mechanical properties.展开更多
With an ultimate range up to 1000 km,a maximum operating depth of 6000 m,and a generous payload capacity,Autosub6000 is well placed to become one of the world's most capable deep diving Autonomous Underwater Vehic...With an ultimate range up to 1000 km,a maximum operating depth of 6000 m,and a generous payload capacity,Autosub6000 is well placed to become one of the world's most capable deep diving Autonomous Underwater Vehicles(AUVs). Recently,Autosub6000 successfully completed its first deep water engineering trials,and in September 2008,fitted with a multibeam sonar,will carry out its first science missions.This paper will describe how we are tackling the design issues that specifically affect a deep diving AUV which must be capable of operating with true autonomy,independently of the mother ship, namely:carrying adequate energy for long endurance and range,coping with varying buoyancy,and maintaining accurate navigation throughout missions lasting up to several days.Results from the recent engineering trails are presented,and future missions and development plans are discussed.展开更多
Silver nanoparticles of mean size 16 nm were synthesized by inert gas condensation （IGC） method. Crystalline structure, morphology and nanoparticles size estimation were conducted by X-ray diffraction （XRD） and tr...Silver nanoparticles of mean size 16 nm were synthesized by inert gas condensation （IGC） method. Crystalline structure, morphology and nanoparticles size estimation were conducted by X-ray diffraction （XRD） and transmission electron microscopy （TEM）. Antibacterial activity of these silver nanoparticles as a function of particles concentration against gram-negative bacterium Escherichia coli （E. coli） was carried out in liquid as well as solid growth media. Scanning electron microscopy （SEM） and TEM studies showed that silver nanoparticles after interaction with E.coli have adhered to and penetrated into the bacterial cells. Antibacterial properties of silver nanoparticles are attributed to their total surface area, as a larger surface to volume ratio of nanoparticles provides more efficient means for enhanced antibacterial activity.展开更多
Black shale samples were collected from Chimiari Khyber Pakthunkhawa region of Pakistan and were analyzed for elemental compositions. Atomic Absorption Spectrophotometry (AAS) was utilized for the determination of ele...Black shale samples were collected from Chimiari Khyber Pakthunkhawa region of Pakistan and were analyzed for elemental compositions. Atomic Absorption Spectrophotometry (AAS) was utilized for the determination of elements in the digested solutions. The analysis of black shale was performed precisely with relative standard deviation (RSD) lower than 2%. Results showed that the samples contained high concentrations of Ca (11.98 %), Al (7.09%), Fe (3.03%), Mg (0.59%) and Ti (0.58%).展开更多
The evolution of microstructure parameters （precipitate size and volume fraction） for two types of Al-Zn-Mg-Cu alloys （7075 and 7055） during aging has been studied by synchrotron-radiation small angle X-ray scatte...The evolution of microstructure parameters （precipitate size and volume fraction） for two types of Al-Zn-Mg-Cu alloys （7075 and 7055） during aging has been studied by synchrotron-radiation small angle X-ray scattering （SAXS）.The results show that the precipitates are only a few nanorneters for both alloys ageing even at higher temperature of 160℃ for 72 h （4.44 and 5.82 nm, respectively）. The maximum of the precipitate volume fraction increases with in creasing Zn content and is about 0.023-0.028 and 0.052-0.054, respectively. The coarsening of precipitate is consistent with LSW （Lifshitz-Slyozov-Wagner） model even at the initial stage where volume fraction is still varying.The activation energy of coarsening regime has been determined to be about 1.22±0.02 eV and 1.25±0.02 eV for alloys 7075 and 7055, respectively.展开更多
Generation of induced pluripotent stem （iPS） cells from somatic cells has been achieved successfully by simultaneous viral transduction of defined reprogramming transcription factors （TFs）. However, the process re...Generation of induced pluripotent stem （iPS） cells from somatic cells has been achieved successfully by simultaneous viral transduction of defined reprogramming transcription factors （TFs）. However, the process requires multiple viral vectors for gene delivery. As a result, generated iPS cells harbor numerous viral integration sites in their genomes. This can increase the probability of gene mutagenesis and genomic instability, and present significant barriers to both research and clinical application studies of iPS cells. In this paper, we present a simple lentivirus reprogramming system in which defined factors are fused in-frame into a single open reading frame （ORF） via self-cleaving 2A sequences. A GFP marker is placed downstream of the transgene to enable tracking of transgene expression. We demonstrate that this polycistronic expression system efficiently generates iPS cells. The generated iPS cells have normal karyotypes and are similar to mouse embryonic stem cells in morphology and gene expression. Moreover, they can differentiate into cell types of the three embryonic germ layers in both in vitro and in vivo assays. Remarkably, most of these iPS cells only harbor a single copy of viral vector. This system provides a valuable tool for generation of iPS cells, and our data suggest that the balance of expression of transduced reprogramming TFs in each cell is essential for the reprogramming process. More importantly, when delivered by non-integrating gene-delivery systems, this re-engineered single ORF will facilitate efficient generation of human iPS cells free of genetic modifications.展开更多
The photocatalytic degradation of phenol and 4-chlorophenol （4-CP） in aqueous suspensions with the use of titanium dioxide （TiO2 ） under UV irradiation was examined. The effects of different supporting materials m...The photocatalytic degradation of phenol and 4-chlorophenol （4-CP） in aqueous suspensions with the use of titanium dioxide （TiO2 ） under UV irradiation was examined. The effects of different supporting materials mixed physically with TiO2 were studied to achieve maximum degradation efficiency. Among the three supports, namely activated carbon （AC）, silica （SiO2 ） and zeolite （ZSM-5）, all exhibited paramount efficiency for degradation of phenol and 4-CP and was better than TiO2 alone. The optimum concentration was found to be 50 mg for all supporting materials. The efficiency order of the three supports was as follows： AC 〉 ZSM-5 〉 SiO2 , respectively. Whilst, the degradation of phenol and 4-CP was improved from 70.6% to 87.6% and 80.6% to 89.7%, respectively, within 120 min photocatalysis in the presence of optimal amount of AC. The degradation was also comparatively enhanced in the presence of cheaper rice husk and the activity was closed to ZSM-5 and lower than AC.展开更多
Mahonia leschenaultia（ML） and Mahonia napaulensis（MN） are less known and unexplored medicinal plants of the family Berberidaceae. They are used by the Todas of Nilgiris in their religious and medical practices but...Mahonia leschenaultia（ML） and Mahonia napaulensis（MN） are less known and unexplored medicinal plants of the family Berberidaceae. They are used by the Todas of Nilgiris in their religious and medical practices but chemically less identified. Hence, we decided to do extensive phytochemical analysis to explore the potential of these plant extracts. An ultrahigh performance electrospray tandem mass spectrometry（UHPLC-ESI-MS/MS）method was successfully developed for qualitative analysis of the bioactive components in Mahonia species using Orbitrap Velos Pro mass spectrometer. Sixteen compounds were identified by comparison of their retention times and mass spectra（MS） with authentic standards and reported literature. Multi-stage mass spectra（MS（2-8）） for the identification of protoberberine and aporphine alkaloids showed the sequential expulsion of all the substituents attached with their basic skeleton followed by CO loss. Eight of the identified compounds（berberine, jatrorrhizine, palmatine, magnoflorine, isocorydine, glaucine, tetrahydropalmatine and tetrahydroberberine） were simultaneously determined by another UHPLC-ESI-MS/MS method under the multiple reactions monitoring（MRM） mode quantitatively using triple quadrupole linear ion trap mass spectrometer. The analytical method was validated for 8 bioactive compounds with overall recovery in the range98.5%-103.6%（RSD≤2.2%）, precise（RSD≤2.07%） and linear（r≥0.9995） over the concentration range of 0.5-1000 ng/mL and successfully applied in ML and MN roots, which suggests the suitability of the proposed approach for the routine analysis of Mahonia species and their quality control.展开更多
Percutaneous coronary intervention for the treatment of coronary artery disease is most commonly performed in the UK through the radial artery,as this is considered to be safer than the femoral approach.However,despit...Percutaneous coronary intervention for the treatment of coronary artery disease is most commonly performed in the UK through the radial artery,as this is considered to be safer than the femoral approach.However,despite improvements in technology and techniques,complications can occur.The most common complication,arterial spasm,can cause intense pain and,in some cases,procedural failure.The incidence of spasm is dependent on several variables,including operator experience,artery size,and equipment used.An antispasmolytic cocktail can be applied to reduce spasm,which usually includes an exogenous nitric oxide(NO)donor(glyceryl trinitrate).NO is an endogenous local vasodilator and therefore is a potential target for anti-spasm intervention.However,systemic administration can result in unwanted side-effects,such as hypotension.A method that adopts local delivery of NO might be advantageous.This review article describes the mechanisms involved in radial artery spasm,discusses the advantages and disadvantages of current strategies to reduce spasm,and highlight the potential of NO-loaded nanoporous materials for use in this setting.展开更多
The adherent thermal layering was undertaken by chemical vapor deposition （CVD） method using saturated solution of boric acid in ultra pure CH3OH. The influence of temperature was studied by varying temperature from...The adherent thermal layering was undertaken by chemical vapor deposition （CVD） method using saturated solution of boric acid in ultra pure CH3OH. The influence of temperature was studied by varying temperature from 100 to 600℃ during the process of boron deposition. The most optimum temperature was found to be 200℃. The effect of time span was observed from 6 to 120 h. The generation of micro or nano-scale thickness could be achieved by reducing time span of the experiment. The behavior of CVD was characterized by using scanning electron microscope, absorbance spectrohotometer and atomic emission spectrograph.展开更多
Small angle X-ray scattering has been used to study the variation of microstructure parameters in an Al-Zn-Mg-Cu-Li alloy aged at various temperatures for various durations. Coarsening of precipitates was studied by a...Small angle X-ray scattering has been used to study the variation of microstructure parameters in an Al-Zn-Mg-Cu-Li alloy aged at various temperatures for various durations. Coarsening of precipitates was studied by analyzing the curve of kinetics strength vs the cube of radius. The results show that the coarsening of precipitates conforms to LSW principle. In addition, the characteristic of s^3J(s) vs s curves was analyzed. The results show that the curves for samples aged at 160 ℃ for various durations(24, 48 and 96 h) have negative deviation, which maybe results in the formation of certain new precipitate. In the other aging treatment states, the curves conform to Porod principle which means there is sharp boundary between the precipitates and matrix.展开更多
Excavation of underground caverns,such as mountain tunnels and energy-storage caverns,may cause the damages to the surrounding rock as a result of the stress redistribution.In this influenced zone,new cracks and disco...Excavation of underground caverns,such as mountain tunnels and energy-storage caverns,may cause the damages to the surrounding rock as a result of the stress redistribution.In this influenced zone,new cracks and discontinuities are created or propagate in the rock mass.Therefore,it is effective to measure and evaluate the acoustic emission(AE)events generated by the rocks,which is a small elastic vibration,and permeability change.The authors have developed a long-term measurement device that incorporates an optical AE(O-AE)sensor,an optical pore pressure sensor,and an optical temperature sensor in a single multi-optical measurement probe(MOP).Japan Atomic Energy Agency has been conducting R&D activities to enhance the reliability of high-level radioactive waste(HLW)deep geological disposal technology.In a high-level radioactive disposal project,one of the challenges is the development of methods for long-term monitoring of rock mass behavior.Therefore,in January 2014,the long-term measurements of the hydro-mechanical behavior of the rock mass were launched using the developed MOP in the vicinity of 350 m below the surface at the Horonobe Underground Research Center.The measurement results show that AEs occur frequently up to 1.5 m from the wall during excavation.In addition,hydraulic conductivity increased by 2e4 orders of magnitude.Elastoplastic analysis revealed that the hydraulic behavior of the rock mass affected the pore pressure fluctuations and caused micro-fractures.Based on this,a conceptual model is developed to represent the excavation damaged zone(EDZ),which contributes to the safe geological disposal of radioactive waste.展开更多
A black shale sample collected from the Chimiari site(Tarbela) was analyzed for elemental contents.Inductively coupled plasma-optical emission spectrometry(ICP-OES) was employed to determine major and trace elements i...A black shale sample collected from the Chimiari site(Tarbela) was analyzed for elemental contents.Inductively coupled plasma-optical emission spectrometry(ICP-OES) was employed to determine major and trace elements in the digests.Precise analysis was accomplished for the black shales,which was better than 2.0%.Result shows that the shales are very rich in Ca(25439 μg·g-1),Fe(13933 μg·g-1),Ti(6932 μg·g-1),Al(5993 μg·g-1) and K(2730 μg·g-1).展开更多
Reticulate spore ornamentation in Strobilomyces(Boletaceae,Basidiomycotina) is visible under light microscopy(bright field and phase contrast) up to 1,500×.While some distinctions can be made at this magnificatio...Reticulate spore ornamentation in Strobilomyces(Boletaceae,Basidiomycotina) is visible under light microscopy(bright field and phase contrast) up to 1,500×.While some distinctions can be made at this magnification,ontogeny and fine structure of the ornamentation cannot be discerned.Scanning electron microscope images,conversely,reveal significant additional structure from which the ontogenetic process can be traced.Citing numerous New and Old World collections,this paper presents evidence distinguishing reticulate ornamentation ontogeny in these disjunct populations.展开更多
ISO 1496-3：1995, Series 1 Freight Containers—Specification and Testing, Part 3：Tank Containers for Liquids,Gases and PressurizedDry Bulk, hereinafter abbreviated ＂1995 edition＂. ISO 1496-3：1995 AMENDMENT 1 2006-...ISO 1496-3：1995, Series 1 Freight Containers—Specification and Testing, Part 3：Tank Containers for Liquids,Gases and PressurizedDry Bulk, hereinafter abbreviated ＂1995 edition＂. ISO 1496-3：1995 AMENDMENT 1 2006-02-01,展开更多
Three-tier knowledge management system based on .NET architecture is designed according to requirement specification, characteristics of and relationship between enterprise electronic archives and knowledge management...Three-tier knowledge management system based on .NET architecture is designed according to requirement specification, characteristics of and relationship between enterprise electronic archives and knowledge management. This system using three-tier design based on factory pattern has good encapsulation and portability, with clearer and more concise structure. It degrades the costs of system development and maintenance and upgrades system’s high reusability and development efficiency.展开更多
High throughput gene expression analysis is swiftly becoming the focal point for deciphering molecular mechanisms underlying various dif-ferent biological questions. Testament to this is the fact that vast volumes of ...High throughput gene expression analysis is swiftly becoming the focal point for deciphering molecular mechanisms underlying various dif-ferent biological questions. Testament to this is the fact that vast volumes of expression profiles are being generated rapidly by scientists worldwide and subsequently stored in publicly available data repositories such as ArrayEx-press and the Gene Expression Omnibus (GEO). Such wealth of biological data has motivated biologists to compare expression profiles gen-erated from biologically-related microarray ex-periments in order to unravel biological mecha-nisms underlying various states of diseases. However, without the availability of appropriate software and tools, they are compelled to use manual or labour-intensive methods of com-parisons. A scrutiny of current literature makes it apparent that there is a soaring need for such bioinformatics tools that cater for the multiple analyses of expression profiles. In order to contribute towards this need, we have developed an efficient software pipeline for the analysis of multiple gene expression data-sets, called Micropath, which implements three principal functions;1) it searches for common genes amongst n number of datasets using a number crunching method of comparison as well as applying the principle of permutations and combinations in the form of a search strat-egy, 2) it extracts gene expression patterns both graphically and statistically, and 3) it streams co-expressed genes to all molecular pathways belonging to KEGG in a live fashion. We sub-jected MicroPath to several expression datasets generated from our tolerance-related in-house microarray experiments as well as published data and identified a set of 31 candidate genes that were found to be co-expressed across all interesting datasets. Pathway analysis revealed their putative roles in regulating immune toler-ance. MicroPath is freely available to download from: www.1066technologies.co.uk/micropath.展开更多
基金supported by the Gas Hydrate R&D Organization and the Korea Institute of Geoscience and Mineral Resources(KIGAM)(GP2021-010)supported by the National Research Foundation of Korea(NRF)grant funded by the Korean government(MSIT)(No.2021R1C1C1004460)Korea Institute of Energy Technology Evaluation and Planning(KETEP)grant funded by the Korean government(MOTIE)(20214000000500,Training Program of CCUS for Green Growth).
文摘Gas hydrate(GH)is an unconventional resource estimated at 1000-120,000 trillion m^(3)worldwide.Research on GH is ongoing to determine its geological and flow characteristics for commercial produc-tion.After two large-scale drilling expeditions to study the GH-bearing zone in the Ulleung Basin,the mineral composition of 488 sediment samples was analyzed using X-ray diffraction(XRD).Because the analysis is costly and dependent on experts,a machine learning model was developed to predict the mineral composition using XRD intensity profiles as input data.However,the model’s performance was limited because of improper preprocessing of the intensity profile.Because preprocessing was applied to each feature,the intensity trend was not preserved even though this factor is the most important when analyzing mineral composition.In this study,the profile was preprocessed for each sample using min-max scaling because relative intensity is critical for mineral analysis.For 49 test data among the 488 data,the convolutional neural network(CNN)model improved the average absolute error and coefficient of determination by 41%and 46%,respectively,than those of CNN model with feature-based pre-processing.This study confirms that combining preprocessing for each sample with CNN is the most efficient approach for analyzing XRD data.The developed model can be used for the compositional analysis of sediment samples from the Ulleung Basin and the Korea Plateau.In addition,the overall procedure can be applied to any XRD data of sediments worldwide.
基金supported by the Key R&D Program of Zhejiang(No.KZ7240079).
文摘Metastable β-Ti alloys exhibiting twinning-induced plasticity (TWIP) and transformation-induced plasticity (TRIP) generally have excellent ductility, but typically at the expense of relatively low yield strengths which has restricted their widespread use. Our work shows that interstitial oxygen can be employed to regulate β phase stability to significantly enhance both strength and ductility of TWIP/TRIP alloys. For a Ti-32Nb wt.% base alloy, inclusion of 0.3 wt.% O enhanced ductility by more than 140 %, reaching up to 54 % strain, and improved the tensile yield strength by over 95 % to 632 MPa. Compared to other common engineering alloys such as Ti-45Nb, elongation was increased by 29 %, and the yield strength increased by 182 MPa, respectively. Here, we elucidate on impacts of oxygen doping on TWIP/TRIP behaviors in the Ti-32Nb alloy. We reveal that oxygen regulates the critical stress for martensitic transformation, twinning, and dislocation slip. At lower oxygen doping concentrations (≤0.3 wt.% O), multi-stage martensitic transformation and martensitic twinning resulted in high ductility. In higher oxygen content alloys (≥0.5 wt.% O), deformation occurred initially via twinning, while strain induced martensite was subsequently induced in retained β phase regions. Oxygen concentrations control the deformation mechanisms, providing a flexible means to synergistically balance an alloy's strength and ductility. The use of oxygen to enhance stability of the β phase and regulate deformation behaviors is a promising new approach for creating high-performance TWIP/TRIP metastable β-Ti alloys with outstanding mechanical properties.
文摘With an ultimate range up to 1000 km,a maximum operating depth of 6000 m,and a generous payload capacity,Autosub6000 is well placed to become one of the world's most capable deep diving Autonomous Underwater Vehicles(AUVs). Recently,Autosub6000 successfully completed its first deep water engineering trials,and in September 2008,fitted with a multibeam sonar,will carry out its first science missions.This paper will describe how we are tackling the design issues that specifically affect a deep diving AUV which must be capable of operating with true autonomy,independently of the mother ship, namely:carrying adequate energy for long endurance and range,coping with varying buoyancy,and maintaining accurate navigation throughout missions lasting up to several days.Results from the recent engineering trails are presented,and future missions and development plans are discussed.
文摘Silver nanoparticles of mean size 16 nm were synthesized by inert gas condensation （IGC） method. Crystalline structure, morphology and nanoparticles size estimation were conducted by X-ray diffraction （XRD） and transmission electron microscopy （TEM）. Antibacterial activity of these silver nanoparticles as a function of particles concentration against gram-negative bacterium Escherichia coli （E. coli） was carried out in liquid as well as solid growth media. Scanning electron microscopy （SEM） and TEM studies showed that silver nanoparticles after interaction with E.coli have adhered to and penetrated into the bacterial cells. Antibacterial properties of silver nanoparticles are attributed to their total surface area, as a larger surface to volume ratio of nanoparticles provides more efficient means for enhanced antibacterial activity.
文摘Black shale samples were collected from Chimiari Khyber Pakthunkhawa region of Pakistan and were analyzed for elemental compositions. Atomic Absorption Spectrophotometry (AAS) was utilized for the determination of elements in the digested solutions. The analysis of black shale was performed precisely with relative standard deviation (RSD) lower than 2%. Results showed that the samples contained high concentrations of Ca (11.98 %), Al (7.09%), Fe (3.03%), Mg (0.59%) and Ti (0.58%).
基金This research was supported by the National Key Fun-damental Research Project of China(No.G19990649)National“863”High Technology Program of China(No.2001 A A332030).
文摘The evolution of microstructure parameters （precipitate size and volume fraction） for two types of Al-Zn-Mg-Cu alloys （7075 and 7055） during aging has been studied by synchrotron-radiation small angle X-ray scattering （SAXS）.The results show that the precipitates are only a few nanorneters for both alloys ageing even at higher temperature of 160℃ for 72 h （4.44 and 5.82 nm, respectively）. The maximum of the precipitate volume fraction increases with in creasing Zn content and is about 0.023-0.028 and 0.052-0.054, respectively. The coarsening of precipitate is consistent with LSW （Lifshitz-Slyozov-Wagner） model even at the initial stage where volume fraction is still varying.The activation energy of coarsening regime has been determined to be about 1.22±0.02 eV and 1.25±0.02 eV for alloys 7075 and 7055, respectively.
文摘Generation of induced pluripotent stem （iPS） cells from somatic cells has been achieved successfully by simultaneous viral transduction of defined reprogramming transcription factors （TFs）. However, the process requires multiple viral vectors for gene delivery. As a result, generated iPS cells harbor numerous viral integration sites in their genomes. This can increase the probability of gene mutagenesis and genomic instability, and present significant barriers to both research and clinical application studies of iPS cells. In this paper, we present a simple lentivirus reprogramming system in which defined factors are fused in-frame into a single open reading frame （ORF） via self-cleaving 2A sequences. A GFP marker is placed downstream of the transgene to enable tracking of transgene expression. We demonstrate that this polycistronic expression system efficiently generates iPS cells. The generated iPS cells have normal karyotypes and are similar to mouse embryonic stem cells in morphology and gene expression. Moreover, they can differentiate into cell types of the three embryonic germ layers in both in vitro and in vivo assays. Remarkably, most of these iPS cells only harbor a single copy of viral vector. This system provides a valuable tool for generation of iPS cells, and our data suggest that the balance of expression of transduced reprogramming TFs in each cell is essential for the reprogramming process. More importantly, when delivered by non-integrating gene-delivery systems, this re-engineered single ORF will facilitate efficient generation of human iPS cells free of genetic modifications.
文摘The photocatalytic degradation of phenol and 4-chlorophenol （4-CP） in aqueous suspensions with the use of titanium dioxide （TiO2 ） under UV irradiation was examined. The effects of different supporting materials mixed physically with TiO2 were studied to achieve maximum degradation efficiency. Among the three supports, namely activated carbon （AC）, silica （SiO2 ） and zeolite （ZSM-5）, all exhibited paramount efficiency for degradation of phenol and 4-CP and was better than TiO2 alone. The optimum concentration was found to be 50 mg for all supporting materials. The efficiency order of the three supports was as follows： AC 〉 ZSM-5 〉 SiO2 , respectively. Whilst, the degradation of phenol and 4-CP was improved from 70.6% to 87.6% and 80.6% to 89.7%, respectively, within 120 min photocatalysis in the presence of optimal amount of AC. The degradation was also comparatively enhanced in the presence of cheaper rice husk and the activity was closed to ZSM-5 and lower than AC.
文摘Mahonia leschenaultia（ML） and Mahonia napaulensis（MN） are less known and unexplored medicinal plants of the family Berberidaceae. They are used by the Todas of Nilgiris in their religious and medical practices but chemically less identified. Hence, we decided to do extensive phytochemical analysis to explore the potential of these plant extracts. An ultrahigh performance electrospray tandem mass spectrometry（UHPLC-ESI-MS/MS）method was successfully developed for qualitative analysis of the bioactive components in Mahonia species using Orbitrap Velos Pro mass spectrometer. Sixteen compounds were identified by comparison of their retention times and mass spectra（MS） with authentic standards and reported literature. Multi-stage mass spectra（MS（2-8）） for the identification of protoberberine and aporphine alkaloids showed the sequential expulsion of all the substituents attached with their basic skeleton followed by CO loss. Eight of the identified compounds（berberine, jatrorrhizine, palmatine, magnoflorine, isocorydine, glaucine, tetrahydropalmatine and tetrahydroberberine） were simultaneously determined by another UHPLC-ESI-MS/MS method under the multiple reactions monitoring（MRM） mode quantitatively using triple quadrupole linear ion trap mass spectrometer. The analytical method was validated for 8 bioactive compounds with overall recovery in the range98.5%-103.6%（RSD≤2.2%）, precise（RSD≤2.07%） and linear（r≥0.9995） over the concentration range of 0.5-1000 ng/mL and successfully applied in ML and MN roots, which suggests the suitability of the proposed approach for the routine analysis of Mahonia species and their quality control.
基金Supported by the European Social Fund and Scottish Funding Council as part of Developing Scotland’s Workforce in the Scotland 2014-2020 European Structural and Investment Fund Programme
文摘Percutaneous coronary intervention for the treatment of coronary artery disease is most commonly performed in the UK through the radial artery,as this is considered to be safer than the femoral approach.However,despite improvements in technology and techniques,complications can occur.The most common complication,arterial spasm,can cause intense pain and,in some cases,procedural failure.The incidence of spasm is dependent on several variables,including operator experience,artery size,and equipment used.An antispasmolytic cocktail can be applied to reduce spasm,which usually includes an exogenous nitric oxide(NO)donor(glyceryl trinitrate).NO is an endogenous local vasodilator and therefore is a potential target for anti-spasm intervention.However,systemic administration can result in unwanted side-effects,such as hypotension.A method that adopts local delivery of NO might be advantageous.This review article describes the mechanisms involved in radial artery spasm,discusses the advantages and disadvantages of current strategies to reduce spasm,and highlight the potential of NO-loaded nanoporous materials for use in this setting.
文摘The adherent thermal layering was undertaken by chemical vapor deposition （CVD） method using saturated solution of boric acid in ultra pure CH3OH. The influence of temperature was studied by varying temperature from 100 to 600℃ during the process of boron deposition. The most optimum temperature was found to be 200℃. The effect of time span was observed from 6 to 120 h. The generation of micro or nano-scale thickness could be achieved by reducing time span of the experiment. The behavior of CVD was characterized by using scanning electron microscope, absorbance spectrohotometer and atomic emission spectrograph.
文摘Small angle X-ray scattering has been used to study the variation of microstructure parameters in an Al-Zn-Mg-Cu-Li alloy aged at various temperatures for various durations. Coarsening of precipitates was studied by analyzing the curve of kinetics strength vs the cube of radius. The results show that the coarsening of precipitates conforms to LSW principle. In addition, the characteristic of s^3J(s) vs s curves was analyzed. The results show that the curves for samples aged at 160 ℃ for various durations(24, 48 and 96 h) have negative deviation, which maybe results in the formation of certain new precipitate. In the other aging treatment states, the curves conform to Porod principle which means there is sharp boundary between the precipitates and matrix.
文摘Excavation of underground caverns,such as mountain tunnels and energy-storage caverns,may cause the damages to the surrounding rock as a result of the stress redistribution.In this influenced zone,new cracks and discontinuities are created or propagate in the rock mass.Therefore,it is effective to measure and evaluate the acoustic emission(AE)events generated by the rocks,which is a small elastic vibration,and permeability change.The authors have developed a long-term measurement device that incorporates an optical AE(O-AE)sensor,an optical pore pressure sensor,and an optical temperature sensor in a single multi-optical measurement probe(MOP).Japan Atomic Energy Agency has been conducting R&D activities to enhance the reliability of high-level radioactive waste(HLW)deep geological disposal technology.In a high-level radioactive disposal project,one of the challenges is the development of methods for long-term monitoring of rock mass behavior.Therefore,in January 2014,the long-term measurements of the hydro-mechanical behavior of the rock mass were launched using the developed MOP in the vicinity of 350 m below the surface at the Horonobe Underground Research Center.The measurement results show that AEs occur frequently up to 1.5 m from the wall during excavation.In addition,hydraulic conductivity increased by 2e4 orders of magnitude.Elastoplastic analysis revealed that the hydraulic behavior of the rock mass affected the pore pressure fluctuations and caused micro-fractures.Based on this,a conceptual model is developed to represent the excavation damaged zone(EDZ),which contributes to the safe geological disposal of radioactive waste.
文摘A black shale sample collected from the Chimiari site(Tarbela) was analyzed for elemental contents.Inductively coupled plasma-optical emission spectrometry(ICP-OES) was employed to determine major and trace elements in the digests.Precise analysis was accomplished for the black shales,which was better than 2.0%.Result shows that the shales are very rich in Ca(25439 μg·g-1),Fe(13933 μg·g-1),Ti(6932 μg·g-1),Al(5993 μg·g-1) and K(2730 μg·g-1).
文摘Reticulate spore ornamentation in Strobilomyces(Boletaceae,Basidiomycotina) is visible under light microscopy(bright field and phase contrast) up to 1,500×.While some distinctions can be made at this magnification,ontogeny and fine structure of the ornamentation cannot be discerned.Scanning electron microscope images,conversely,reveal significant additional structure from which the ontogenetic process can be traced.Citing numerous New and Old World collections,this paper presents evidence distinguishing reticulate ornamentation ontogeny in these disjunct populations.
文摘ISO 1496-3：1995, Series 1 Freight Containers—Specification and Testing, Part 3：Tank Containers for Liquids,Gases and PressurizedDry Bulk, hereinafter abbreviated ＂1995 edition＂. ISO 1496-3：1995 AMENDMENT 1 2006-02-01,
文摘Three-tier knowledge management system based on .NET architecture is designed according to requirement specification, characteristics of and relationship between enterprise electronic archives and knowledge management. This system using three-tier design based on factory pattern has good encapsulation and portability, with clearer and more concise structure. It degrades the costs of system development and maintenance and upgrades system’s high reusability and development efficiency.
文摘High throughput gene expression analysis is swiftly becoming the focal point for deciphering molecular mechanisms underlying various dif-ferent biological questions. Testament to this is the fact that vast volumes of expression profiles are being generated rapidly by scientists worldwide and subsequently stored in publicly available data repositories such as ArrayEx-press and the Gene Expression Omnibus (GEO). Such wealth of biological data has motivated biologists to compare expression profiles gen-erated from biologically-related microarray ex-periments in order to unravel biological mecha-nisms underlying various states of diseases. However, without the availability of appropriate software and tools, they are compelled to use manual or labour-intensive methods of com-parisons. A scrutiny of current literature makes it apparent that there is a soaring need for such bioinformatics tools that cater for the multiple analyses of expression profiles. In order to contribute towards this need, we have developed an efficient software pipeline for the analysis of multiple gene expression data-sets, called Micropath, which implements three principal functions;1) it searches for common genes amongst n number of datasets using a number crunching method of comparison as well as applying the principle of permutations and combinations in the form of a search strat-egy, 2) it extracts gene expression patterns both graphically and statistically, and 3) it streams co-expressed genes to all molecular pathways belonging to KEGG in a live fashion. We sub-jected MicroPath to several expression datasets generated from our tolerance-related in-house microarray experiments as well as published data and identified a set of 31 candidate genes that were found to be co-expressed across all interesting datasets. Pathway analysis revealed their putative roles in regulating immune toler-ance. MicroPath is freely available to download from: www.1066technologies.co.uk/micropath.
