The effect of nickel contamination under rapid thermal processing （RTP） on the magic denuded zone （MDZ） in Czochralski silicon is investigated. It is found that the bulk defects can effectively getter nickel atoms...The effect of nickel contamination under rapid thermal processing （RTP） on the magic denuded zone （MDZ） in Czochralski silicon is investigated. It is found that the bulk defects can effectively getter nickel atoms once the MDZ forms. However,if the silicon sample is initially contaminated with nickel, the MDZ cannot form during the subsequent RTP,and a high density of precipitates occurs near the surface. In conventional IG processes,the DZ can form regardless of the nickel contamination sequence. Based on the facts,we propose that the formation of nickel silicide （Ni3Si） at the surface keeps the concentration of vacancies in the near-surface zone still higher than the critical concentration for oxygen precipitation under the subsequent RTP, which prevents MDZ formation.展开更多
[Objective] This study aimed to improve the in vitro maturation quality of denuded porcine oocytes and provide scientific basis for establishing a stable and efficient denuded oocyte culture system. [Method] The first...[Objective] This study aimed to improve the in vitro maturation quality of denuded porcine oocytes and provide scientific basis for establishing a stable and efficient denuded oocyte culture system. [Method] The first polar body extrusion rate, oocyte glutathione （GSH） content, positive rate of brilliant cresyl blue （BCB） staining and development potential of activated oocytes or fertilized oocytes were employed as main indicators to investigate the effects of follicular mural granulosa cell （MGC） coculture on cytoplasmic maturation of cumulus cell-removal oocytes （Denuded Oocyte, DO）. [Result] According to in vitro maturation results, compared with DO group, the first polar body extrusion rate of porcine oocytes in DO＋MGC group was not significantly different, but the nuclear maturation process was improved and was more similar to that in COC （cumulus-oocyte complex） group. Detection of GSH content in mature oocytes showed that there was no significant difference between DO＋ MGC group （optical density of 1 053.67） and COC group （optical density of 1 426.00） or between DO＋MGC group and COC＋GC group （optical density of 1 541.00）, however, GSH content in mature oocytes of DO group （optical density of 724.67） was significantly lower than that of COC group and COC＋GC group （P0.05）. Detection of glucose-6-phosphate dehydrogenase （G6PDH） activity showed that there was no significant difference in BCB positive oocyte rate between DO ＋MGC group （88.26% ） and COC group （92.75%） or between DO＋MGC group and DO group （82.86% ）, however, BCB positive oocyte rate of DO group was significantly lower than that of COC group （P0.05）. Furthermore, the cleavage rate and blastocyst rate of activated mature oocytes derived from DO ＋MGC group （94.98% and 43.67% , respectively） were significantly higher than those from DO group （52.54% and 8.97%, respectively） （P0.05）, and were not significantly different compared with those from COC group （97.11% and 38.30%, respectively）. In addition, the cleavage rate of fertilized oocytes derived from DO＋MGC group （72.65%） showed no significant difference compared with that from DO group （63.59%）, but the blastocyst rate of DO＋MGC group was significantly higher than that of DO group （9.88%） （P0.05）. [Conclusion] MGC coculture can significantly improve the in vitro cytoplasmic maturation quality of denuded porcine oocytes, thereby enhancing the subsequent developmental potential.展开更多
AIM: To establish an untransfected human corneal epithelial (HCEP) cell line and characterize its biocompatibility with denuded amniotic membrane (dAM). METHODS: The torn HCEP pieces were primarily cultured in DMEM/F1...AIM: To establish an untransfected human corneal epithelial (HCEP) cell line and characterize its biocompatibility with denuded amniotic membrane (dAM). METHODS: The torn HCEP pieces were primarily cultured in DMEM/F12 media (pH 7.2) supplemented with 20% fetal bovine serum and other necessary factors, yielding an HCEP cell line which was its growth performance, chromosome morphology, tumorigenicity and expression of marker proteins analyzed. In addition, the biocompatibility of HCEP cells with dAM was evaluated through histological and immunocytochemistry analyses and with light, electron and slit-lamp microscopies. RESULTS: HCEP cells proliferated to confluence in 3 weeks, which have been subcultured to passage 160. A continuous untransfected HCEP cell line, designated as utHCEPC01, was established with a population doubling time of 45.42 hours as was determined at passage 100. The cells retained HCEP cell properties as were approved by chromosomal morphology and the expression of keratin 3. They, with no tumorigenicity, formed a multilayer epithelium-like structure on dAMs through proliferation and differentiation during air-liquid interface culture, maintained expression of marker proteins including keratin 3 and integrin p 1 and attached tightly to dAMs. The reconstructed HCEP was highly transparent and morphologically and structurally similar to the original. CONCLUSION: An untransfected and non-tumorigenic HCEP cell line was established in this study. The cells maintained expression of marker proteins. The cell line was biocompatible with dAM. It holds the potential of being used for in vitro reconstruction of tissue-engineered HCEP, promising for the treatment of diseases caused by corneal epithelial disorders.展开更多
A numerical simulation model has been developed to investigate the diffusion and reaction in diffusion denuder for reactive gases and aerosols. The analytical equation for equilibrium and kinetic equations of NH 4NO ...A numerical simulation model has been developed to investigate the diffusion and reaction in diffusion denuder for reactive gases and aerosols. The analytical equation for equilibrium and kinetic equations of NH 4NO 3, NH 3 and HNO 3 system were presented. The model results of sampling efficiencies were agree with those calculated by Gormley Kennedy equation and other models. The evaporation of NH 4NO 3 aerosol has a kinetic constraint. The kinetic constant can be estimated from evaporation data. The model results showed that an annular denuder can separate reactive gases and aerosols.展开更多
KCl denuder technique was meployed in the measurement of Hg(II) species in atmosphere firstly. Intensive lab tests indicate that Hg 0 can pass through KCl denuder freely, while Hg 2+ can be trapped in it very ef...KCl denuder technique was meployed in the measurement of Hg(II) species in atmosphere firstly. Intensive lab tests indicate that Hg 0 can pass through KCl denuder freely, while Hg 2+ can be trapped in it very efficiently. The efficiencies for adsorbing inorganic Hg 2+ averaged between 95% to 100% with a gross mean of 98%, and those for absorption of organic Hg 2+ were around 94%. Mass balance calculation shows that mercury trapped in denuder can be quantitatively extracted by 1 mol/L HCl (super grade) and analysed by the method of SnCl 2 reduction CVAFS determination, thus, demonstrated the feasibility of KCl denuder in measurement of Hg(II) in atmosphere. Preliminary application at two sites Gteborg, Sweden and one site in Ireland, found 0 04—0 15 ng/m 3 of Hg(II) species, contributing to 2%—10% of the total mercury.展开更多
The influence of co-precipitation of copper and nickel on the formation of a denuded zone （DZ） in Czochralski silicon （Cz Si） was systematically investigated by means of etching and optical microscopy （OM）. It w...The influence of co-precipitation of copper and nickel on the formation of a denuded zone （DZ） in Czochralski silicon （Cz Si） was systematically investigated by means of etching and optical microscopy （OM）. It was found that, for conventional high-low-high annealing （CFA）, the DZ could be obtained in all specimens contaminated by copper and nickel co-impurity at different steps of the heat treatment, indicating that no copper precipitates or nickel precipitates were generated in the region just below the surface. However, for rapid thermal annealing （RTA）-low-high annealing, the tendency is not the same; the DZ could not be found in the specimen which was contaminated by copper and nickel contamination before the first RTA annealing. On the basis of the experimental results, it was supposed that the concentration and distribution of the vacancies generating during the RTA can influence the distribution of copper precipitation and nickel precipitation along the cross-section of Cz Si significantly, and thus influence the formation of the DZ to a great extent.展开更多
Polycyclic aromatic hydrocarbons （PAHs） are complex organic compounds which are identified as significant carcinogenic to human health. PAHs （mainly in particle phase） are susceptible to atmospheric oxidant gases,...Polycyclic aromatic hydrocarbons （PAHs） are complex organic compounds which are identified as significant carcinogenic to human health. PAHs （mainly in particle phase） are susceptible to atmospheric oxidant gases, especially ozone, nitrogen oxides （NOx）, hydroxyl radical （OH）, and could be degraded on filters during sampling process, leading to an underestimation of ambient PAH concentrations. The goal of this work was to investigate particle associated PAHs sampling artifacts caused by ozone in summer of Beijing. Comparative sampling systems were operated simultaneously during the whole campaign, one with activated carbon ozone denuder, the other being set as conventional sampling system. Activated carbon denuder was testified to be highly efficient to eliminate ozone from air stream. In general, nine particle-bound PAHs observed from conventional sampler were all lower than those from ozone denuder system. The total PAHs （particle phase） concentration was averagely underestimated by 35.9% in conventional sampling procedure. Benzo[a]pyrene （BaP） had the highest percentage of mass loss. founded to have influences Ambient temperature was on PAHs sampling artifacts. High temperature can increase loss of particle associated PAHs during sampling.展开更多
Restoration of denudation thickness is of great significance to understanding tectonic evolution,hydrocarbon migration and accumulation history in petroliferous basins.How to accurately restore and distinguish denudat...Restoration of denudation thickness is of great significance to understanding tectonic evolution,hydrocarbon migration and accumulation history in petroliferous basins.How to accurately restore and distinguish denudation thicknesses in different periods,however,is difficult.With measurements of vitrinite reflectance(Ro)and interval transit time,along with stratigraphic profile comparison,we restored the total denudation thickness of the Cretaceous in the central Sichuan Basin at a depth range of1100-3300 m.The apatite fission track analysis(AFTA)was employed to identify the denudation periods,namely,the Late Yanshanian,Early Himalayan and the Late Himalayan orogenic epochs,and the ratio of their denudation intensity is about 3.8:1:3.9.The denudation thicknesses at different periods provide an important basis for tectonic evolution and hydrocarbon migration and accumulation.Affected by the diverse denudation intensities,the paleo-structures in the study area feature high in the south and low in the north at the Late Jurassic,high in the north and low in the south at the late Early Cretaceous,high in the southeast and low in the northwest at present in succession.EW-and NE-trending folds and faults are the products of inherited development,which have a controlling effect on hydrocarbon migration and accumulation.展开更多
Karst phenomena occurring on land surface create sinkholes,ground fissures and other hazardous events.Dissolution of gypsum of Upper Devonian formations in North Lithuania,that occur under thin Quaternary cover result...Karst phenomena occurring on land surface create sinkholes,ground fissures and other hazardous events.Dissolution of gypsum of Upper Devonian formations in North Lithuania,that occur under thin Quaternary cover results with rapid occurrence of hazardous sinkholes.Monitoring of karst phenomena in Lithuania includes measurements of volumes of karst sinkholes(cubic meters)and amount of dissolved underground gypsum–named chemical gypsum denudation measured by amount cubic meters of gypsum dissolved from 1 square kilometer of karst terrain during one year.展开更多
The effect of rapid thermal annealing （RTA） ambient on denuded zone and oxygen precipitates in Czochralski （CZ） silicon wafers is studied in this paper. N2 and a N2/NH3 mixture are used as RTA ambient. It is demon...The effect of rapid thermal annealing （RTA） ambient on denuded zone and oxygen precipitates in Czochralski （CZ） silicon wafers is studied in this paper. N2 and a N2/NH3 mixture are used as RTA ambient. It is demonstrated that a high density of oxygen precipitates and thin denuded zone are obtained in N2/NH3 ambient,while a relatively lower density of oxygen precipitates and thicker denuded zone are observed in N2 ambient. As the RTA duration times increased, the oxygen precipitate density increased and the denuded zone depth decreased. X-ray photoelectron spectroscopy （XPS） data and atomic force microscope （AFM） results show that there RTA process,which can explain the different effect of RTA was a surface nitriding reaction during the N2/NH3 ambient ambient.展开更多
AIM: To evaluate the biological functions of tissue-engineered human corneal epithelium (TE-HCEP) by corneal transplantation in limbal stem cell deficiency (LSCD) rabbit models. METHODS: TE-HCEPs were reconstructed wi...AIM: To evaluate the biological functions of tissue-engineered human corneal epithelium (TE-HCEP) by corneal transplantation in limbal stem cell deficiency (LSCD) rabbit models. METHODS: TE-HCEPs were reconstructed with DiI-labeled untransfected HCEP cells and denuded amniotic membrane (dAM) in air-liquid interface culture, and their morphology and structure were characterized by hematoxylin-eosin (HE) staining of paraffin-sections, immunohistochemistry and electron microscopy. LSCD models were established by mechanical and alcohol treatment of the left eyes of New Zealand white rabbits, and their eyes were transplanted with TE-HCEPs with dAM surface outside by lamellar keratoplasty (LKP). Corneal transparency, neovascularization, thickness, and epithelial integrality of both traumatic and post transplantation eyes were checked once a week by slit-lamp corneal microscopy, a corneal pachymeter, and periodic acid-Schiff (PAS) staining. At day 120 post surgery, the rabbits in each group were sacrificed and their corneas were examined by DiI label observation, HE staining, immunohistochemistry and electron microscopy. RESULTS: After cultured for 5 days on dAM, HCEP cells, maintaining keratin 3 expression, reconstructed a 6-7 layer TE-HCEP with normal morphology and structure. The traumatic rabbit corneas, entirely opaque, conjunctivalized and with invaded blood vessels, were used as LSCD models for TE-HCEP transplantation. After transplantation, obvious edema was not found in TE-HCEP-transplanted corneas which became more and more transparent, the invaded blood vessels reduced gradually throughout the monitoring period. The corneas decreased to normal thickness on day 25, while those of dAM eyes were over 575 mu m in thickness during the monitoring period. A 45 layer of epithelium consisting of TE-HCEP originated cells attached tightly to the anterior surface of stroma was reconstructed 120 days after TE-HCEP transplantation, which was similar to the normal control eye in morphology and structure. In contrast, intense corneal edema, turbid, invaded blood vessels were found in dAM eyes, and no multilayer epithelium was found but only a few scattered conjunctiva-like cells appeared. CONCLUSION: The TE-HCEP, with similar morphology and structure to those of innate HCEP, could reconstruct a multilayer corneal epithelium with normal functions in restoring corneal transparency and thickness of LSCD rabbits after transplantation. It may be a promising HCEP equivalent for clinical therapy of corneal epithelial disorders.展开更多
AIM: To demonstrate the morphology and structure of in vitro reconstructed tissue-engineered human corneal epithelium (TE-HCEP) with seeder cells from an untransfected HCEP cell line. METHODS: The TE-HCEPs were recons...AIM: To demonstrate the morphology and structure of in vitro reconstructed tissue-engineered human corneal epithelium (TE-HCEP) with seeder cells from an untransfected HCEP cell line. METHODS: The TE-HCEPs were reconstructed in vitro with seeder cells from an untransfected HCEP cell line, and scaffold carriers of denuded amniotic membrane (dAM) in air-liquid interface culture for 3, 5, 7 and 9 days, respectively. The specimens were examined with hematoxylin-eosin (HE) staining of paraffin-section, immunocytochemical staining, scanning and transmission electron microscopy. RESULTS: During in vitro reconstruction of TE-HCEP, HCEP cells formed a 3-4, 6-7 and 8-10 layers of an HCEP-like structure on dAMs in air-liquid interface culture for 3, 5 and 7 days, respectively. But the cells deceased to 5-6 layers and the structure of straified epithelium became loose at day 9. And the cells maintained positive expression of marker proteins (keratin 3 and keratin 12), cell-junction proteins (zonula occludens-1, E-cadherin, connexin 43 and integrin beta 1) and membrane transport protein of Na+-K+ ATPase. The HCEP cells in TE-HCEP were rich in microvilli on apical surface and established numerous cell-cell and cell-dAM junctions at day 5. CONCLUSION: The morphology and structure of the reconstructed TE-HCEP were similar to those of HCEP in vivo. The HCEP cells in the reconstructed TE-HCEP maintained the properties of HCEP cells, including abilities of forming intercellular and cell-extracellular matrix junctions and abilities of performing membrane transportation. The untransfected HCEP cells and dAMs could promisingly be used in reconstruction HCEP equivalent for clinical corneal epithelium transplantation.展开更多
Well Shuangyushi 1 and Well Nanchong l deployed in the NW and central Sichuan Basin have obtained a high-yield industrial gas flow in the dolomite and karst reservoirs of the Middle Permian Maokou Formation,showing go...Well Shuangyushi 1 and Well Nanchong l deployed in the NW and central Sichuan Basin have obtained a high-yield industrial gas flow in the dolomite and karst reservoirs of the Middle Permian Maokou Formation,showing good exploration prospects of the Maokou Formation.In order to identify the sequence stratigraphic features of the Maokou Formation,its sequence stratigraphy was divided and a unified sequence stratigraphic framework applicable for the entire basin was established to analyze the stratigraphic denudation features within the sequence framework by using the spectral curve trend attribute analysis,together with drilling and outcrop data.On this basis,the controls of sequence on source rocks and reservoirs were analyzed.In particular,the Maokou Formation was divided into two third-order sequences e SQ1 and SQ2.SQ1 was composed of members Mao 1 Member and Mao 3,while SQ2 was composed of Mao 4 Member.Sequence stratigraphic correlation indicated that the Maokou Formation within the basin had experienced erosion to varying extent,forming“three intense and two weak”denuded regions,among which,the upper part of SQ2 was slightly denuded in the two weak denuded regions(SW Sichuan Basin and locally Eastern Sichuan Basin),while SQ2 was denuded out in the three intense denuded regions(Southern Sichuan BasineCentral Sichuan Basin,NE and NW Sichuan Basin).The development of source rocks and reservoirs within sequence stratigraphic framework was significantly affected by sequence boundary;the grain banks that can form effective reservoir were predominately distributed in SQ1 highstand systems tract(HST),while effective source rocks were predominately distributed in SQ1 transgressive system tract(TST).It is concluded that the sequence division method is objective and reasonable,which can effectively guide oil and gas exploration in this region.展开更多
（U-Th）/He dating is a newly developed low temperature thermochronometry, and it elaborately reflects cooling history of geologic body under low temperature. It can be applied to analyze thermal evolution of the sedi...（U-Th）/He dating is a newly developed low temperature thermochronometry, and it elaborately reflects cooling history of geologic body under low temperature. It can be applied to analyze thermal evolution of the sedimentary basin, combining with vitrinite reflectance and fission track. （U-Th）/He dating of apatite and zircon from drilling cores in Puguang （普光）-Maoba （毛坝） area and outcrops in Tongjiang （通江） area indicates that the Northeast Sichuan （四川） basin underwent great uplift and denudation during the Tertiary and the Quaternary. During the period, denudation rates changed from 74.8 to 172.5 m/Ma and denudation thickness was between 2 800 and 3 000 m, geotemperature gradually declined into the current temperature, passing through helium closure temperature of apatite. The uplift and denudation relate to new tectonic movement response in the Sichuan basin aroused by the Qinghai （青海）-Tibet plateau. Drilling samples above 4 000 m did not undergo closure temperature of zircon, but the samples nearly 4 000 m might approach closure temperature of zircon and all the samples underwent closure temperature of apatite. According to （U-Th）/He ages of zircon, it is concluded that the Northeast Sichuan basin began to uplift in the Late Jurassic. From the Late Jurassic to the Paleogene, Northeast Sichuan basin was in slow uplift and denudation, but the denudation of Puguang-Maoba area was earlier than that of Tongjiang area. （U-Th）/He ages of zircon indicate the denudation time of provenance areas. On the basis of paleodrainage characteristics, provenance transport and other related data, provenance areas of the clastie rocks are decided, which is worthy to be investigated further.展开更多
The early stage of Sichuan Basin formation was controlled by the convergence of three major Chinese continental blocks during the Indosinian orogeny that include South China,North China,and Qiangtang blocks.Although t...The early stage of Sichuan Basin formation was controlled by the convergence of three major Chinese continental blocks during the Indosinian orogeny that include South China,North China,and Qiangtang blocks.Although the Late Triassic Xujiahe Formation is assumed to represent the commencement of continental deposition in the Sichuan Basin,little research is available on the details of this particular stratum.Sequence stratigraphic analysis reveals that the Xujiahe Formation comprises four third-order depositional sequences.Moreover,two tectono-sedimentary evolution stages,deposition and denudation,have been identified.Typical wedge-shaped geometry revealed in a cross section of the southern Sichuan Basin normal to the Longmen Shan fold-thrust belt is displayed for the entire Xujiahe Formation.The depositional extent did not cover the Luzhou paleohigh during the LST1 to LST2 （LST,TST and HST mean Iowstand,transgressive and highstand systems tracts,1,2,3 and 4 represent depositional sequence 1,2,3 and 4）,deltaic and fluvial systems fed sediments from the Longmen Shan belt,Luzhou paleohigh,Hannan dome,and Daba Shan paleohigh into a foreland basin with a centrally located lake.The forebulge of the western Sichuan foreland basin was located southeast of the Luzhou paleohigh after LST2.According to the principle of nonmarine sequence stratigraphy and the lithology of the Xujiahe Formation,four thrusting events in the Longmen Shan fold-thrust belt were distinguished,corresponding to the basal boundaries of sequences 1,2,3,and 4.The northern Sichuan Basin was tilted after the deposition of sequence 3,inducing intensive erosion of sequences 3 and 4,and formation of wedge-shaped deposition geometry in sequence 4 from south to north.The tilting probably resulted from small-scale subduction and exhumation of the western South China block during the South and North China block collision.展开更多
The history and geodynamic mechanisms of Cenozoic exhumation and denudation of the Lhasa terrane(LT),southern Tibetan Plateau,remain poorly constrained.Most previous studies investigating the exhumation of the LT have...The history and geodynamic mechanisms of Cenozoic exhumation and denudation of the Lhasa terrane(LT),southern Tibetan Plateau,remain poorly constrained.Most previous studies investigating the exhumation of the LT have relied on extrapolating interpretations based on a few well-studied but small areas,which inevitably introduce bias.Here,our compilation of new and published thermochronologic ages are plotted against latitude,longitude,and elevation,to illustrate the distribution of cooling ages across broad regions of the LT.Primary results reveal that(1)the north LT experienced significant exhumation during 80–40 Ma;(2)compared with north LT,exhumation and erosion in the south LT continued after~40 Ma;and(3)N–S striking rifting,E–W striking river incision,and thrusts led to continued local denudation of the south LT between 20–5 Ma.展开更多
The restoration of the denudation thickness is the basis for quantitatively analyzing the basin burial history,thermal evolution history and hydrocarbon accumulation conditions.The well data is not sufficient to do th...The restoration of the denudation thickness is the basis for quantitatively analyzing the basin burial history,thermal evolution history and hydrocarbon accumulation conditions.The well data is not sufficient to do this in the southern Lishui Sag with only 5 wells,so the new,high-quality three-dimensional(3D)seismic data is essential.The methods employed to determine the eroded thicknesses of key unconformities in the study area are the mudstone acoustic time difference(AC)method,vitrinite reflectance(Ro%)method and stratigraphic trend comparison method.On the basis of the structural evolution,the restoration of the paleogeomorphology is carried out.The results show that the Wenzhou formation(E2 w)in the entire study area has been all denuded.The denudation thickness is in the range of 0–550 m,and decreases gradually from west,thicker than 200 m,to east.The erosion of the upper Lingfeng formation(E1l)are mainly occurred in the N-P-1 structural trap(N-P-1),the N-P-2 structural trap(N-P-2)and the N-P-3 structural trap(N-P-3).Among them,the eroded area in N-P-1(near well S-1)and N-P-2 is 200–230 km^2,and the denudation thickness is 0–600 m,which increases from south to north,even up to 200–400 m in the region around well S-1.In N-P-3,the extent of denudation is 30–50 km^2,and the denudation thickness is 0–400 m.In the early stage of the upper E1 l,one north-south strike slip fault began to develop in the southern study area.Affected by this fault,the southern Lingfeng bulge was offset,forming a gorge,and the eastern and western sides of the concave belt connected to each other.On the basis of the paleo-geomorphological characteristics,it is shown that the sedimentary center of the west subsag began to migrate to the south.展开更多
文摘The effect of nickel contamination under rapid thermal processing （RTP） on the magic denuded zone （MDZ） in Czochralski silicon is investigated. It is found that the bulk defects can effectively getter nickel atoms once the MDZ forms. However,if the silicon sample is initially contaminated with nickel, the MDZ cannot form during the subsequent RTP,and a high density of precipitates occurs near the surface. In conventional IG processes,the DZ can form regardless of the nickel contamination sequence. Based on the facts,we propose that the formation of nickel silicide （Ni3Si） at the surface keeps the concentration of vacancies in the near-surface zone still higher than the critical concentration for oxygen precipitation under the subsequent RTP, which prevents MDZ formation.
基金Supported by National Natural Science Foundation of China (30871431)Outstanding Youth Fund of Heilongjiang Province (JC200905)~~
文摘[Objective] This study aimed to improve the in vitro maturation quality of denuded porcine oocytes and provide scientific basis for establishing a stable and efficient denuded oocyte culture system. [Method] The first polar body extrusion rate, oocyte glutathione （GSH） content, positive rate of brilliant cresyl blue （BCB） staining and development potential of activated oocytes or fertilized oocytes were employed as main indicators to investigate the effects of follicular mural granulosa cell （MGC） coculture on cytoplasmic maturation of cumulus cell-removal oocytes （Denuded Oocyte, DO）. [Result] According to in vitro maturation results, compared with DO group, the first polar body extrusion rate of porcine oocytes in DO＋MGC group was not significantly different, but the nuclear maturation process was improved and was more similar to that in COC （cumulus-oocyte complex） group. Detection of GSH content in mature oocytes showed that there was no significant difference between DO＋ MGC group （optical density of 1 053.67） and COC group （optical density of 1 426.00） or between DO＋MGC group and COC＋GC group （optical density of 1 541.00）, however, GSH content in mature oocytes of DO group （optical density of 724.67） was significantly lower than that of COC group and COC＋GC group （P0.05）. Detection of glucose-6-phosphate dehydrogenase （G6PDH） activity showed that there was no significant difference in BCB positive oocyte rate between DO ＋MGC group （88.26% ） and COC group （92.75%） or between DO＋MGC group and DO group （82.86% ）, however, BCB positive oocyte rate of DO group was significantly lower than that of COC group （P0.05）. Furthermore, the cleavage rate and blastocyst rate of activated mature oocytes derived from DO ＋MGC group （94.98% and 43.67% , respectively） were significantly higher than those from DO group （52.54% and 8.97%, respectively） （P0.05）, and were not significantly different compared with those from COC group （97.11% and 38.30%, respectively）. In addition, the cleavage rate of fertilized oocytes derived from DO＋MGC group （72.65%） showed no significant difference compared with that from DO group （63.59%）, but the blastocyst rate of DO＋MGC group was significantly higher than that of DO group （9.88%） （P0.05）. [Conclusion] MGC coculture can significantly improve the in vitro cytoplasmic maturation quality of denuded porcine oocytes, thereby enhancing the subsequent developmental potential.
基金Supported by National High Technology Research and Development Program ("863" Program) of China(No. 2006AA02A132)
文摘AIM: To establish an untransfected human corneal epithelial (HCEP) cell line and characterize its biocompatibility with denuded amniotic membrane (dAM). METHODS: The torn HCEP pieces were primarily cultured in DMEM/F12 media (pH 7.2) supplemented with 20% fetal bovine serum and other necessary factors, yielding an HCEP cell line which was its growth performance, chromosome morphology, tumorigenicity and expression of marker proteins analyzed. In addition, the biocompatibility of HCEP cells with dAM was evaluated through histological and immunocytochemistry analyses and with light, electron and slit-lamp microscopies. RESULTS: HCEP cells proliferated to confluence in 3 weeks, which have been subcultured to passage 160. A continuous untransfected HCEP cell line, designated as utHCEPC01, was established with a population doubling time of 45.42 hours as was determined at passage 100. The cells retained HCEP cell properties as were approved by chromosomal morphology and the expression of keratin 3. They, with no tumorigenicity, formed a multilayer epithelium-like structure on dAMs through proliferation and differentiation during air-liquid interface culture, maintained expression of marker proteins including keratin 3 and integrin p 1 and attached tightly to dAMs. The reconstructed HCEP was highly transparent and morphologically and structurally similar to the original. CONCLUSION: An untransfected and non-tumorigenic HCEP cell line was established in this study. The cells maintained expression of marker proteins. The cell line was biocompatible with dAM. It holds the potential of being used for in vitro reconstruction of tissue-engineered HCEP, promising for the treatment of diseases caused by corneal epithelial disorders.
文摘A numerical simulation model has been developed to investigate the diffusion and reaction in diffusion denuder for reactive gases and aerosols. The analytical equation for equilibrium and kinetic equations of NH 4NO 3, NH 3 and HNO 3 system were presented. The model results of sampling efficiencies were agree with those calculated by Gormley Kennedy equation and other models. The evaporation of NH 4NO 3 aerosol has a kinetic constraint. The kinetic constant can be estimated from evaporation data. The model results showed that an annular denuder can separate reactive gases and aerosols.
文摘KCl denuder technique was meployed in the measurement of Hg(II) species in atmosphere firstly. Intensive lab tests indicate that Hg 0 can pass through KCl denuder freely, while Hg 2+ can be trapped in it very efficiently. The efficiencies for adsorbing inorganic Hg 2+ averaged between 95% to 100% with a gross mean of 98%, and those for absorption of organic Hg 2+ were around 94%. Mass balance calculation shows that mercury trapped in denuder can be quantitatively extracted by 1 mol/L HCl (super grade) and analysed by the method of SnCl 2 reduction CVAFS determination, thus, demonstrated the feasibility of KCl denuder in measurement of Hg(II) in atmosphere. Preliminary application at two sites Gteborg, Sweden and one site in Ireland, found 0 04—0 15 ng/m 3 of Hg(II) species, contributing to 2%—10% of the total mercury.
基金supported by the National Natural Science Foundation of China(No.50902116)the Opening Project of State Key Laboratory of Silicon Materials,China(No.SKL2012-17)
文摘The influence of co-precipitation of copper and nickel on the formation of a denuded zone （DZ） in Czochralski silicon （Cz Si） was systematically investigated by means of etching and optical microscopy （OM）. It was found that, for conventional high-low-high annealing （CFA）, the DZ could be obtained in all specimens contaminated by copper and nickel co-impurity at different steps of the heat treatment, indicating that no copper precipitates or nickel precipitates were generated in the region just below the surface. However, for rapid thermal annealing （RTA）-low-high annealing, the tendency is not the same; the DZ could not be found in the specimen which was contaminated by copper and nickel contamination before the first RTA annealing. On the basis of the experimental results, it was supposed that the concentration and distribution of the vacancies generating during the RTA can influence the distribution of copper precipitation and nickel precipitation along the cross-section of Cz Si significantly, and thus influence the formation of the DZ to a great extent.
文摘Polycyclic aromatic hydrocarbons （PAHs） are complex organic compounds which are identified as significant carcinogenic to human health. PAHs （mainly in particle phase） are susceptible to atmospheric oxidant gases, especially ozone, nitrogen oxides （NOx）, hydroxyl radical （OH）, and could be degraded on filters during sampling process, leading to an underestimation of ambient PAH concentrations. The goal of this work was to investigate particle associated PAHs sampling artifacts caused by ozone in summer of Beijing. Comparative sampling systems were operated simultaneously during the whole campaign, one with activated carbon ozone denuder, the other being set as conventional sampling system. Activated carbon denuder was testified to be highly efficient to eliminate ozone from air stream. In general, nine particle-bound PAHs observed from conventional sampler were all lower than those from ozone denuder system. The total PAHs （particle phase） concentration was averagely underestimated by 35.9% in conventional sampling procedure. Benzo[a]pyrene （BaP） had the highest percentage of mass loss. founded to have influences Ambient temperature was on PAHs sampling artifacts. High temperature can increase loss of particle associated PAHs during sampling.
基金financially supported by the National Natural Science Foundation of China(42272151)。
文摘Restoration of denudation thickness is of great significance to understanding tectonic evolution,hydrocarbon migration and accumulation history in petroliferous basins.How to accurately restore and distinguish denudation thicknesses in different periods,however,is difficult.With measurements of vitrinite reflectance(Ro)and interval transit time,along with stratigraphic profile comparison,we restored the total denudation thickness of the Cretaceous in the central Sichuan Basin at a depth range of1100-3300 m.The apatite fission track analysis(AFTA)was employed to identify the denudation periods,namely,the Late Yanshanian,Early Himalayan and the Late Himalayan orogenic epochs,and the ratio of their denudation intensity is about 3.8:1:3.9.The denudation thicknesses at different periods provide an important basis for tectonic evolution and hydrocarbon migration and accumulation.Affected by the diverse denudation intensities,the paleo-structures in the study area feature high in the south and low in the north at the Late Jurassic,high in the north and low in the south at the late Early Cretaceous,high in the southeast and low in the northwest at present in succession.EW-and NE-trending folds and faults are the products of inherited development,which have a controlling effect on hydrocarbon migration and accumulation.
基金supported by the Ministry of Education,Science and Sport of Republic of Lithuania under the program“An influence of the climate of the climatic and anthropogenic driven factors on the ecosystems and their behaviors,services provided and sustainability of the resources”(20220419/V-585)The monitoring of karst denudation and mapping of sinkholes was funded by Lithuanian Geological Survey under Ministry of Environment,Republic of Lithuania.
文摘Karst phenomena occurring on land surface create sinkholes,ground fissures and other hazardous events.Dissolution of gypsum of Upper Devonian formations in North Lithuania,that occur under thin Quaternary cover results with rapid occurrence of hazardous sinkholes.Monitoring of karst phenomena in Lithuania includes measurements of volumes of karst sinkholes(cubic meters)and amount of dissolved underground gypsum–named chemical gypsum denudation measured by amount cubic meters of gypsum dissolved from 1 square kilometer of karst terrain during one year.
文摘The effect of rapid thermal annealing （RTA） ambient on denuded zone and oxygen precipitates in Czochralski （CZ） silicon wafers is studied in this paper. N2 and a N2/NH3 mixture are used as RTA ambient. It is demonstrated that a high density of oxygen precipitates and thin denuded zone are obtained in N2/NH3 ambient,while a relatively lower density of oxygen precipitates and thicker denuded zone are observed in N2 ambient. As the RTA duration times increased, the oxygen precipitate density increased and the denuded zone depth decreased. X-ray photoelectron spectroscopy （XPS） data and atomic force microscope （AFM） results show that there RTA process,which can explain the different effect of RTA was a surface nitriding reaction during the N2/NH3 ambient ambient.
基金National High Technology Research and Development Program ("863"Program) of China (No.2006AA 02A132)
文摘AIM: To evaluate the biological functions of tissue-engineered human corneal epithelium (TE-HCEP) by corneal transplantation in limbal stem cell deficiency (LSCD) rabbit models. METHODS: TE-HCEPs were reconstructed with DiI-labeled untransfected HCEP cells and denuded amniotic membrane (dAM) in air-liquid interface culture, and their morphology and structure were characterized by hematoxylin-eosin (HE) staining of paraffin-sections, immunohistochemistry and electron microscopy. LSCD models were established by mechanical and alcohol treatment of the left eyes of New Zealand white rabbits, and their eyes were transplanted with TE-HCEPs with dAM surface outside by lamellar keratoplasty (LKP). Corneal transparency, neovascularization, thickness, and epithelial integrality of both traumatic and post transplantation eyes were checked once a week by slit-lamp corneal microscopy, a corneal pachymeter, and periodic acid-Schiff (PAS) staining. At day 120 post surgery, the rabbits in each group were sacrificed and their corneas were examined by DiI label observation, HE staining, immunohistochemistry and electron microscopy. RESULTS: After cultured for 5 days on dAM, HCEP cells, maintaining keratin 3 expression, reconstructed a 6-7 layer TE-HCEP with normal morphology and structure. The traumatic rabbit corneas, entirely opaque, conjunctivalized and with invaded blood vessels, were used as LSCD models for TE-HCEP transplantation. After transplantation, obvious edema was not found in TE-HCEP-transplanted corneas which became more and more transparent, the invaded blood vessels reduced gradually throughout the monitoring period. The corneas decreased to normal thickness on day 25, while those of dAM eyes were over 575 mu m in thickness during the monitoring period. A 45 layer of epithelium consisting of TE-HCEP originated cells attached tightly to the anterior surface of stroma was reconstructed 120 days after TE-HCEP transplantation, which was similar to the normal control eye in morphology and structure. In contrast, intense corneal edema, turbid, invaded blood vessels were found in dAM eyes, and no multilayer epithelium was found but only a few scattered conjunctiva-like cells appeared. CONCLUSION: The TE-HCEP, with similar morphology and structure to those of innate HCEP, could reconstruct a multilayer corneal epithelium with normal functions in restoring corneal transparency and thickness of LSCD rabbits after transplantation. It may be a promising HCEP equivalent for clinical therapy of corneal epithelial disorders.
基金Supported by National High Technology Research and Development Program("863" Program) of China(No.2006AA02A132)
文摘AIM: To demonstrate the morphology and structure of in vitro reconstructed tissue-engineered human corneal epithelium (TE-HCEP) with seeder cells from an untransfected HCEP cell line. METHODS: The TE-HCEPs were reconstructed in vitro with seeder cells from an untransfected HCEP cell line, and scaffold carriers of denuded amniotic membrane (dAM) in air-liquid interface culture for 3, 5, 7 and 9 days, respectively. The specimens were examined with hematoxylin-eosin (HE) staining of paraffin-section, immunocytochemical staining, scanning and transmission electron microscopy. RESULTS: During in vitro reconstruction of TE-HCEP, HCEP cells formed a 3-4, 6-7 and 8-10 layers of an HCEP-like structure on dAMs in air-liquid interface culture for 3, 5 and 7 days, respectively. But the cells deceased to 5-6 layers and the structure of straified epithelium became loose at day 9. And the cells maintained positive expression of marker proteins (keratin 3 and keratin 12), cell-junction proteins (zonula occludens-1, E-cadherin, connexin 43 and integrin beta 1) and membrane transport protein of Na+-K+ ATPase. The HCEP cells in TE-HCEP were rich in microvilli on apical surface and established numerous cell-cell and cell-dAM junctions at day 5. CONCLUSION: The morphology and structure of the reconstructed TE-HCEP were similar to those of HCEP in vivo. The HCEP cells in the reconstructed TE-HCEP maintained the properties of HCEP cells, including abilities of forming intercellular and cell-extracellular matrix junctions and abilities of performing membrane transportation. The untransfected HCEP cells and dAMs could promisingly be used in reconstruction HCEP equivalent for clinical corneal epithelium transplantation.
基金Special and Significant Project of National Science and Technology“Study on oil and gas resources potential of marine carbonate rocks and formation conditions and distribution of giant oil and gas fields”(No.2011ZX05004-001).
文摘Well Shuangyushi 1 and Well Nanchong l deployed in the NW and central Sichuan Basin have obtained a high-yield industrial gas flow in the dolomite and karst reservoirs of the Middle Permian Maokou Formation,showing good exploration prospects of the Maokou Formation.In order to identify the sequence stratigraphic features of the Maokou Formation,its sequence stratigraphy was divided and a unified sequence stratigraphic framework applicable for the entire basin was established to analyze the stratigraphic denudation features within the sequence framework by using the spectral curve trend attribute analysis,together with drilling and outcrop data.On this basis,the controls of sequence on source rocks and reservoirs were analyzed.In particular,the Maokou Formation was divided into two third-order sequences e SQ1 and SQ2.SQ1 was composed of members Mao 1 Member and Mao 3,while SQ2 was composed of Mao 4 Member.Sequence stratigraphic correlation indicated that the Maokou Formation within the basin had experienced erosion to varying extent,forming“three intense and two weak”denuded regions,among which,the upper part of SQ2 was slightly denuded in the two weak denuded regions(SW Sichuan Basin and locally Eastern Sichuan Basin),while SQ2 was denuded out in the three intense denuded regions(Southern Sichuan BasineCentral Sichuan Basin,NE and NW Sichuan Basin).The development of source rocks and reservoirs within sequence stratigraphic framework was significantly affected by sequence boundary;the grain banks that can form effective reservoir were predominately distributed in SQ1 highstand systems tract(HST),while effective source rocks were predominately distributed in SQ1 transgressive system tract(TST).It is concluded that the sequence division method is objective and reasonable,which can effectively guide oil and gas exploration in this region.
基金supported by the National Basic Research Pro-gram of China (No. 2005CB422102)China Petroleum and Chemical Corporation Program (P06083)
文摘（U-Th）/He dating is a newly developed low temperature thermochronometry, and it elaborately reflects cooling history of geologic body under low temperature. It can be applied to analyze thermal evolution of the sedimentary basin, combining with vitrinite reflectance and fission track. （U-Th）/He dating of apatite and zircon from drilling cores in Puguang （普光）-Maoba （毛坝） area and outcrops in Tongjiang （通江） area indicates that the Northeast Sichuan （四川） basin underwent great uplift and denudation during the Tertiary and the Quaternary. During the period, denudation rates changed from 74.8 to 172.5 m/Ma and denudation thickness was between 2 800 and 3 000 m, geotemperature gradually declined into the current temperature, passing through helium closure temperature of apatite. The uplift and denudation relate to new tectonic movement response in the Sichuan basin aroused by the Qinghai （青海）-Tibet plateau. Drilling samples above 4 000 m did not undergo closure temperature of zircon, but the samples nearly 4 000 m might approach closure temperature of zircon and all the samples underwent closure temperature of apatite. According to （U-Th）/He ages of zircon, it is concluded that the Northeast Sichuan basin began to uplift in the Late Jurassic. From the Late Jurassic to the Paleogene, Northeast Sichuan basin was in slow uplift and denudation, but the denudation of Puguang-Maoba area was earlier than that of Tongjiang area. （U-Th）/He ages of zircon indicate the denudation time of provenance areas. On the basis of paleodrainage characteristics, provenance transport and other related data, provenance areas of the clastie rocks are decided, which is worthy to be investigated further.
基金sponsored by the Science Foundation of China University of Petroleum,Beijing (No. QD-201007)the National Nature Science Foundations of China (Grant No. 41102133)financially supported by the foundation of State Key Laboratory of Petroleum Resources and Prospecting, China University of Petroleum (No. PRP/indep-4-1110)
文摘The early stage of Sichuan Basin formation was controlled by the convergence of three major Chinese continental blocks during the Indosinian orogeny that include South China,North China,and Qiangtang blocks.Although the Late Triassic Xujiahe Formation is assumed to represent the commencement of continental deposition in the Sichuan Basin,little research is available on the details of this particular stratum.Sequence stratigraphic analysis reveals that the Xujiahe Formation comprises four third-order depositional sequences.Moreover,two tectono-sedimentary evolution stages,deposition and denudation,have been identified.Typical wedge-shaped geometry revealed in a cross section of the southern Sichuan Basin normal to the Longmen Shan fold-thrust belt is displayed for the entire Xujiahe Formation.The depositional extent did not cover the Luzhou paleohigh during the LST1 to LST2 （LST,TST and HST mean Iowstand,transgressive and highstand systems tracts,1,2,3 and 4 represent depositional sequence 1,2,3 and 4）,deltaic and fluvial systems fed sediments from the Longmen Shan belt,Luzhou paleohigh,Hannan dome,and Daba Shan paleohigh into a foreland basin with a centrally located lake.The forebulge of the western Sichuan foreland basin was located southeast of the Luzhou paleohigh after LST2.According to the principle of nonmarine sequence stratigraphy and the lithology of the Xujiahe Formation,four thrusting events in the Longmen Shan fold-thrust belt were distinguished,corresponding to the basal boundaries of sequences 1,2,3,and 4.The northern Sichuan Basin was tilted after the deposition of sequence 3,inducing intensive erosion of sequences 3 and 4,and formation of wedge-shaped deposition geometry in sequence 4 from south to north.The tilting probably resulted from small-scale subduction and exhumation of the western South China block during the South and North China block collision.
基金co-funded by the National Key Research and Development Project'Key scientific issues of transformative technology'(Grant No.2019YFA0708601)the second Tibetan Plateau Scientific Expedition and Research Program(STEP)Grant(Grant No.2019QZKK0802)+3 种基金the Key Special Project for Introduced Talents Team of Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou)(Grant No.GML2019ZD0201)National Natural Science Foundation of China(Grant Nos.41502198,40921001,41672223)Research Grant of Chinese Academy of Geological Sciences(Grant No.J2024)Geological Survey of China(Grant Nos.DD20190057,DD20190060)。
文摘The history and geodynamic mechanisms of Cenozoic exhumation and denudation of the Lhasa terrane(LT),southern Tibetan Plateau,remain poorly constrained.Most previous studies investigating the exhumation of the LT have relied on extrapolating interpretations based on a few well-studied but small areas,which inevitably introduce bias.Here,our compilation of new and published thermochronologic ages are plotted against latitude,longitude,and elevation,to illustrate the distribution of cooling ages across broad regions of the LT.Primary results reveal that(1)the north LT experienced significant exhumation during 80–40 Ma;(2)compared with north LT,exhumation and erosion in the south LT continued after~40 Ma;and(3)N–S striking rifting,E–W striking river incision,and thrusts led to continued local denudation of the south LT between 20–5 Ma.
基金supported by the National Science and Technology Major Projects(No.2016ZX05027-001-006)
文摘The restoration of the denudation thickness is the basis for quantitatively analyzing the basin burial history,thermal evolution history and hydrocarbon accumulation conditions.The well data is not sufficient to do this in the southern Lishui Sag with only 5 wells,so the new,high-quality three-dimensional(3D)seismic data is essential.The methods employed to determine the eroded thicknesses of key unconformities in the study area are the mudstone acoustic time difference(AC)method,vitrinite reflectance(Ro%)method and stratigraphic trend comparison method.On the basis of the structural evolution,the restoration of the paleogeomorphology is carried out.The results show that the Wenzhou formation(E2 w)in the entire study area has been all denuded.The denudation thickness is in the range of 0–550 m,and decreases gradually from west,thicker than 200 m,to east.The erosion of the upper Lingfeng formation(E1l)are mainly occurred in the N-P-1 structural trap(N-P-1),the N-P-2 structural trap(N-P-2)and the N-P-3 structural trap(N-P-3).Among them,the eroded area in N-P-1(near well S-1)and N-P-2 is 200–230 km^2,and the denudation thickness is 0–600 m,which increases from south to north,even up to 200–400 m in the region around well S-1.In N-P-3,the extent of denudation is 30–50 km^2,and the denudation thickness is 0–400 m.In the early stage of the upper E1 l,one north-south strike slip fault began to develop in the southern study area.Affected by this fault,the southern Lingfeng bulge was offset,forming a gorge,and the eastern and western sides of the concave belt connected to each other.On the basis of the paleo-geomorphological characteristics,it is shown that the sedimentary center of the west subsag began to migrate to the south.
