AIM: To investigate the protective effect of ketamine on the endotoxin-induced proinflammatory cytokines and NFkappa B activation in the intestine. ETHODS: Adult male Wistar rats were randomly divided into 6 groups: (...AIM: To investigate the protective effect of ketamine on the endotoxin-induced proinflammatory cytokines and NFkappa B activation in the intestine. ETHODS: Adult male Wistar rats were randomly divided into 6 groups: (a) normal saline control, (b) challenged with endotoxin (5 mg/kg) and treated by saline, (c) challenged with endotoxin (5 mg/kg) and treated by ketamine (0.5 mg/kg), (d) challenged with endotoxin (5 mg/kg) and treated by ketamine (5 mg/kg ), (e) challenged with endotoxin (5 mg/kg) and treated by ketamine (50 mg/kg), and (f) saline injected and treated by ketamine (50 mg/kg). After 1, 4 or 6 h, TNF-α and IL-6 mRNA were investigated in the tissues of the intestine (jejunum) by RT-PCR. TNF-α and IL-6 were measured by ELISA. We used electrophoretic mobility shift assay (EMSA) to investigate NF-kappa B activity in the intestine. RESULTS: NF-kappa B activity, the expression of TNF-α and IL-6 were enhanced in the intestine by endotoxin. Ketamine at a dose of 0.5 mg/kg could suppress endotoxininduced TNF-α mRNA and protein elevation and inhibit NFkappa B activation in the intestine. However the least dosage of ketamine to inhibit IL-6 was 5 mg/kg in our experiment. CONCLUSION: Ketamine can suppress endotoxin-induced production of proinflammatory cytokines such as TNF-α and IL-6 production in the intestine. This suppressive effect may act through inhibiting NF-kappa B.展开更多
AIM:To study the alterations of brain-gut peptides following traumatic brain injury (TBI) and to explore the underlying significance of these peptides in the complicated gastrointestinal dysfunction.METHODS:Rat models...AIM:To study the alterations of brain-gut peptides following traumatic brain injury (TBI) and to explore the underlying significance of these peptides in the complicated gastrointestinal dysfunction.METHODS:Rat models of focal traumatic brain injury were established by impact insult method,and divided into 6 groups (6 rats each group) including control group with sham operation and TBI groups at postinjury 3,12,24,72h,and d 7.Blood and proximal jejunum samples were taken at time point of each group and gross observations of gastrointestinal pathology were recorded simultaneously.The levels of vasoactive intestinal peptide (VIP) in plasma,calcitonin gene-related peptide (CGRP) and cholecystokinin (CCK) in both plasma and jejunum were measured by enzyme immunoassay (EIA). Radioimmunoassay (RIA) was used to determine the levels of VIP in jejunum.RESULTS:Gastric distension,delayed gastric emptying and intestinal dilatation with a large amount of yellowish effusion and thin edematous wall were found in TBI rats through 12h and 72h, which peaked at postinjury 72h. As compared with that of control group (247.8±29.5ng/L), plasma VIP levels were significantly decreased at postinjury 3,12 and 24h (106.7±34.1ng/L, 148.7±22.8ng/L,132.8±21.6ng/L,respectively),but significantly increased at 72h (405.0±29.8ng/L) and markedly declined on d 7 (130.7±19.3ng/L).However,Plasma levels CCK and CGRP were significantly increased through 3h and 7d following TBI (126-691% increases),with the peak at 72 h.Compared with control (VIP, 13.6±1.4ng/g;CGRP,70.6±17.7ng/g);VIP and CGRP levels in jejunum were significantly increased at 3h after TBI (VIP,35.4±5.0ng/g;CGRP,103.8±22.1ng/g),and declined gradually at 12 h and 2d h (VIP,16.5±1.8ng/g,5.5±1.4ng/g;CGRP,34.9±9.7ng/g, 18.5±7.7ng/g),but were significantly increased again at 72 h (VIP, 48.7±9.5ng/g; CGRP,142.1±24.3ng/g),then declined in various degrees on d 7 (VIP, 3.8±1.1ng/g; CGRP, 102.5±18.1ng/g).The CCK levels in jejunum were found to change in a similar trend as that in plasma with the concentrations of CCK significantly increased following TBI (99-517% increases) and peaked at 72h.CONCLUSION:Traumatic brain injury can lead to significant changes of brain-gut peptides in both plasma and small intestine, which may be involved in the pathogenesis of complicated gastrointestinal dysfunction.展开更多
AIM: To determine the least invasive surgical procedure by comparing the levels of operative stress hormones, responsereactive protein (CRP) and rest energy expenditure (REE)after laparoscopic (LC) and open cholecyste...AIM: To determine the least invasive surgical procedure by comparing the levels of operative stress hormones, responsereactive protein (CRP) and rest energy expenditure (REE)after laparoscopic (LC) and open cholecystectomy (OC).METHODS: Twenty-six consecutive patients with noncomplicated gallstones were randomized for LC (14) and OC (12). Plasma concentrations of somatotropin, insulin, cortisol and CRP were measured. The levels of REE were determined.RESULTS: In the third postoperative day, the insulin levels were lower compared to that before operation (P<0.05).Tn the first postoperative day, the levels of somatotropin and cortisol were higher in OC than those in LC. After operation the parameters of somatotropin, CRP and cortisol increased, compared to those in the preoperative period in the all patients (P<0.05). In the all-postoperative days,the CRP level was higher in OC than that in LC (7.46±0.02;7.38±0.01, P<0.05). After operation the REE level all increased in OC and LC (P<0.05). In the all-postoperative days, the REE level was higher in OC than that in LC (1438.5±A18.5;1222.3±L80.8, P<0.05).CONCLUSION: LC results in less prominent stress response and smaller metabolic interference compared to open surgery. These advantages are beneficial to the restoration of stress hormones, the nitrogen balance, and the energy metabolism. However, LC can also induce acidemia and pulmonary hypoperfusion because of the penumoperitonium it uses during surgery.展开更多
Soil erosion accelerates soil degradation. Some natural soils and cultivated soils on sloping land in southern Jiangsu Province, China were chosen to study soil degradation associated with erosion. Soil erosion intens...Soil erosion accelerates soil degradation. Some natural soils and cultivated soils on sloping land in southern Jiangsu Province, China were chosen to study soil degradation associated with erosion. Soil erosion intensity was investigated using the 137Cs tracer method. Soil particle-size distribution, soil organic matter (OM), total nitrogen (TN) and total phosphorus (TP) were measured, and the effects of erosion on soil physical and chemical properties were analyzed statistically using SYSTAT8.0. Results indicated that erosion intensity of cultivated soils was greater than that of the natural soils, suggesting that cultivation increased soil loss. Erosion also led to an increase of coarser soil particle proportion, especially in natural soils. In addition, silt was the primary soil particle lost due to erosion. However, in cultivated fields, coarser soil particles over time were attributed not only to soil erosion but also to mechanical eluviation as a result of farming activities. Moreover, erosion caused a decrease in soil OM, TN and TP as well as thinning of the soil layer.展开更多
Activated sludge was immobilized into Ca-alginate beads via entrapment, and biosorption of three heavy metal ions, copper(Ⅱ), zinc(Ⅱ), and chromimum(Ⅱ), from aqueous solution in the concentration range of 10\_100 m...Activated sludge was immobilized into Ca-alginate beads via entrapment, and biosorption of three heavy metal ions, copper(Ⅱ), zinc(Ⅱ), and chromimum(Ⅱ), from aqueous solution in the concentration range of 10\_100 mg/L was studied by using both entrapped activated sludge and inactivated free biomass at pH≤5. A biphasic metal adsorption pattern was observed in all immobilized biomass experiments. The biosorption of metal ions by the biosorbents increased with the initial concentration increased in the medium. The adsorption rate of immobilized pre-treated activated sludge(PAS) was much lower than that of free PAS due to the increase in mass transfer resistance resulting from the polymeric matrix. Biosorption equilibrium of beads was established in about 20 h and the adsorbed heavy metal ions did not change further with time. No significant effect of temperature was observed in the test for free biomass while immobilized PAS appeared to be strong temperature dependent in the test range of 10 and 40℃. Besides, the content of activated sludge in the calcium alginate bead has an influence on the uptake of heavy metals. The sorption equilibrium was well modeled by Langmuir isotherm, implying monomolecular adsorption mechanism. Carboxyl group in cell wall played an important role in surface adsorption of heavy metal ions on PAS.展开更多
AIM: To develop an in vitro three-dimensional (3-D) angiogenesis system to analyse the capillary sprouts induced in response to the concentration ranges of basic fibroblast growth factor (bFGF) and vascular endothelia...AIM: To develop an in vitro three-dimensional (3-D) angiogenesis system to analyse the capillary sprouts induced in response to the concentration ranges of basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF) and to quantify their synergistic activity.METHODS: Microcarriers (MCs) coated with human microvascular endothelial cells (HMVECs) were embedded in fibrin gel and cultured in 24-well plates with assay media. The growth factors bFGF, or VEGF, or both were added to the system. The wells (n = 8/group) were digitally photographed and the average length of capillary-like sprouts (ALS) from each microcarrier was quantitated.RESULTS: In aprotinin-stabilized fibrin matrix, human microvascular endothelial cells on the MCs invaded fibrin,forming sprouts and capillary networks with lumina. The angiogenic effects of bFGF or VEGF were dose-clependent in bhe range from 10 to 40 ng/mL. At d 1, 10 ng/mL of bFGF and VEGF induced angiogenesis with an ALS of 32.13±16.6 μm and 43.75±27.92 μm, respectively, which were significantly higher than that of the control (5.88±4.45 μm, P<0.01),and the differences became more significant as the time increased. In addition, the combination of 10 ng/mL of bFGF and VEGF each induced a more significant effect than the summed effects of bFGF (10 ng/mL) alone and VEGF (10 ng/mL) alone when analyzed using SPSS system for general linear model (GLM) (P= 0.011), and bhat also exceeded the effects by 20 ng/mL of either bFGF or VEGF.CONCLUSION: A microcarrier-based in vitro threedimensional angiogenesis model can be developed in fibrin.It offers a unique system for quantitative analysis of angiogenesis. Both bFGF and VEGF exert their angiogenic effects on HMVECs synergistically and in a dose-dependent manner.展开更多
Studies show that the Tianshan orogenic belt was built in the late stage of the Paleozoic, as evidenced by the Permian red molasses and foreland basins, which are distributed in parallel with the Tianshan belt, indica...Studies show that the Tianshan orogenic belt was built in the late stage of the Paleozoic, as evidenced by the Permian red molasses and foreland basins, which are distributed in parallel with the Tianshan belt, indicating that an intense folding and uplifting event took place. During the Triassic, this orogenic belt was strongly eroded, and basins were further developed. Starting from the Jurassic, a within-plate regional extension occurred, forming a series of Jurassic-Paleogene extensional basins in the peneplaned Tianshan region. Since the Neogene, a collision event between the Indian and the Eurasian plates that took place on the southern side of the Tianshan belt has caused a strong intra-continental orogeny, which is characterized by thrusting and folding. Extremely thick coarse conglomerate and sandy conglomerate of the Xiyu Formation of Neogene System were accumulated unconformably on the Tianshan piedmont. Studies have revealed that the strong compression caused by the Indian-Eurasian collision had a profound influence over the orogenic belt in the hinterland, and MesozoiC-Cenozoic brittle deformed structures superposed on the ductile deformed Paleozoic rocks. The Mesozoic extensional basins were converted into Cenozoic compressional basins. The deformation in the basins is featured by step thrusts and fault-related folds. Statistics of joints show that the principal compressive stress since the Neogene is in a N-S direction. Meanwhile, owing to the underthrusting of the basin toward the orogenic belt, the Paleozoic strata were thrust on the Meso-Cenozoic rocks as tectonic slices, revealing distinct kinematic features in different geologic units. The basin-range coupling zones are characterized by intensive compression, folding and thrusting, accompanied by local sub-E-W-trending strike-slip faults. In the Tianshan region, Cenozoic thrusting is the most common basin-range coupling mode. The folding and faulting of Mesozoic sedimentary rocks, spontaneous combustion of Jurassic coal layers and formation of sintered rocks, the Cenozoic earthquakes and active faulting, and the unique mosaic pattern of basin-range framework of Xinjiang are all products of tectonism since the Neogene.展开更多
AIM: Gastrointestinal dysfunction is a common complication in patients with traumatic brain injury (TBI). However, the effect of traumatic brain injury on intestinal mucosa has not been studied previously. The aim of ...AIM: Gastrointestinal dysfunction is a common complication in patients with traumatic brain injury (TBI). However, the effect of traumatic brain injury on intestinal mucosa has not been studied previously. The aim of the current study was to explore the alterations of intestinal mucosa morphology and barrier function, and to determine how rapidly the impairment of gut barrier function occurs and how long it persists following traumatic brain injury.METHODS: Male Wistar rats were randomly divided into six groups (6 rats each group) including controls without brain injury and traumatic brain injury groups at hours 3,12, 24, and 72, and on day 7. The intestinal mucosa structure was detected by histopathological examination and electron microscopy. Gut barrier dysfunction was evaluated by detecting serum endotoxin and intestinal permeability. The level of serum endotoxin and intestinal permeability was measured by using chromogenic limulus amebocyte lysate and lactulose/mannitol (L/M) ratio, respectively.RESULTS: After traumatic brain injury, the histopathological alterations of gut mucosa occurred rapidly as early as 3 hours and progressed to a serious state, including shedding of epithelial cells, fracture of villi, focal ulcer, fusion of adjacent villi, dilation of central chyle duct, mucosal atrophy,and vascular dilation, congestion and edema in the villous interstitium and lamina propria. Apoptosis of epithelial cells,fracture and sparseness of microvilli, loss of tight junction between enterocytes, damage of mitochondria and endoplasm, were found by electron microscopy. The villous height, crypt depth and surface area in jejunum decreased progressively with the time of brain injury. As compared with that of control group (183.7±41.8 EU/L), serum endotoxin level was signnificantly increased at 3, 12, and 24 hours following TBI (434.8±54.9 EU/L, 324.2±61.7 EU/L and 303.3±60.2 EU/L, respectively), and peaked at 72 hours (560.5±76.2 EU/L), then declined on day 7 (306.7±62.4 EU/L,P<0.0L). Two peaks of serum endotoxin level were found at hours 3 and 72 following TBI. L/M ratio was also significantly higher in TBI groups than that in control group (control,0.0172±0.0009; 12 h, 0.0303±0.0013; 24 h, 0.0354±0.0025;72 h, 0.0736±0.0105; 7 d, 0.0588±0.0083; P<0.01).CONCLUSION: Traumatic brain injury can induce significant damages of gut structure and impairment of barrier function which occur rapidly as early as 3 hours following brain injury and lasts for more than 7 days with marked mucosal atrophy.展开更多
AIM: Nuclear factor kappa B (NF-κB) regulates a large number of genes involved in the inflammatory response to critical illnesses, but it is not known if and how NF-KB is activated and intercellular adhesion molecule...AIM: Nuclear factor kappa B (NF-κB) regulates a large number of genes involved in the inflammatory response to critical illnesses, but it is not known if and how NF-KB is activated and intercellular adhesion molecule-1 (ICAM-1) expressed in the gut following traumatic brain injury (TBI). The aim of current study was to investigate the temporal pattern of intestinal NF-κB activation and ICAM-1 expression following TBI. METHODS: Male Wistar rats were randomly divided into six groups (6 rats in each group) including controls with sham operation and TBI groups at hours 3, 12, 24, and 72, and on d 7. Parietal brain contusion was adopted using weight-dropping method. All rats were decapitated at corresponding time point and mid-jejunum samples were taken. NF-KB binding activity in jejunal tissue was measured using EMSA. Immunohistochemistry was used for detection of ICAM-1 expression in jejunal samples. RESULTS: There was a very low NF-κB binding activity and little ICAM-1 expression in the gut of control rats after sham surgery. NF-KB binding activity in jejunum significantly increased by 160% at 3 h following TBI (P<0.05 vs control), peaked at 72 h (500% increase) and remained elevated on d 7 post-injury by 390% increase. Compared to controls, ICAM-1 was significantly up-regulated on the endothelia of microvessels in villous interstitium and lamina propria by 24 h following TBI and maximally expressed at 72 h post-injury (P<0.001). The endothelial ICAM-1 immunoreactivity in jejunal mucosa still remained strong on d 7 post-injury. The peak of NF-κB activation and endothelial ICAM-1 expression coincided in time with the period during which secondary mucosal injury of the gut was also at their culmination following TBI. CONCLUSION: TBI could induce an immediate and persistent up-regulation of NF-κB activity and subsequent up-regulation of ICAM-1 expression in the intestine. Inflammatory response mediated by increased NF-κB activation and ICAM-1 expression may play an important role in the pathogenesis of acute gut mucosal injury following TBI.展开更多
AIM: To determine the effects of total parenteral nutrition and somatostatin on patients with chylous ascites.METHODS: Five patients were diagnosed with chylous ascites on the basis of laboratory findings of ascites s...AIM: To determine the effects of total parenteral nutrition and somatostatin on patients with chylous ascites.METHODS: Five patients were diagnosed with chylous ascites on the basis of laboratory findings of ascites sample from Nov 1999 to May 2003. Total parenteral nutrition and somatostatin or its analogue was administered to 4 patients,while the other one only received total parenteral nutrition.All the patients had persistent peritoneal drainage, with the quantity and quality of drainage fluid observed daily.Necessary supportive treatments were given to the patients individually during the therapy.RESULTS: Two of 4 patients who received somatostatin therapy obtained complete recovery within 10 d without any recurrence while on a normal diet. In these 2 patients,the peritoneal drainage reduced to zero in one and the other's decreased from 2 000 mL to 80 mL with a clear appearance and negative qualitative analysis of chyle. Recurrent chylous ascites, though relieved effectively by the same method every time, developed in one patient with advanced pancreatic cancer. The other patient's lymphatic fistula was blocked with the fibrin glue after conservative treatment. The patient who only received total parenteral nutrition was cured 24 d after therapy.CONCLUSION: Total parenteral nutrition along with somatostatin can relieve the symptoms and close the fistula in patients with chylous ascites rapidly. It appears to be an effective therapy available for the treatment of chylous ascites caused by various disorders.展开更多
As one of the developing countries China has an arable land per capita far below the world’s average level. With a high-density population and the quick development of economy and urbanization, the Yangtze River Delt...As one of the developing countries China has an arable land per capita far below the world’s average level. With a high-density population and the quick development of economy and urbanization, the Yangtze River Delta shows the typical characteristics of land use in developed regions of China, which are: high land reclamation rate and low arable land per capita; intensive land use and high output value; and rapid increasing of construction land area and fast diminishing of arable lands. The analysis indicates that the process of the arable land changes in the Yangtze River Delta could be divided into four different change stages over the past 50 years.展开更多
An important diplogenetic mineralization event superimposed on pre-existing exhalation sediments in the Tongling area, Anhui province, was triggered by widespread granitic magmatism along the northeastern margin of th...An important diplogenetic mineralization event superimposed on pre-existing exhalation sediments in the Tongling area, Anhui province, was triggered by widespread granitic magmatism along the northeastern margin of the Yangtze Block during 140–135 Ma under extensional tectonic circumstances following the collision between the North China and Yangtze blocks. The main orebodies of the Dongguashan copper deposit, a typical diplogenetic stratified deposit among many polymetallic ore deposits in China, are hosted by strata between Upper Devonian sandstone and Carboniferous limestone, and its mineralization was genetically related to the Qingshanjiao intrusive. The Rb-Sr isotopic isochron of the Qingshanjiao intrusive yields an age of about 136.5±1.4 Ma. The ore-forming fluid reflected by the inclusion fluid in quartz veins is characterized by high temperature and high salinity, and its age was also determined by Rb -Sr isotope dating as 134±11 Ma. Oxygen and hydrogen isotope composition data suggest that the ore-forming fluid was derived mainly from magmatism. By integrating these isotopic dating data, characteristics of fluid inclusions and the geology of the deposit, the mineralization of the Dongguashan copper deposit is divided into two stages. First, a stratiform sedimentary deposit or protore layer formed in the Late Devonian to the Early Carboniferous, while in the second stage the pre-existing protore was superimposed by hydrothermal fluid that was derived from the Yanshanian magmatic activities occurring around 135 Ma ago. This two-stage mineralization formed the Dongguashan statiform copper deposit. Associated “porphyry” mineralization found in the bottom of and in surrounding intrusive rocks of the orebodies might have occurred in the same period as a second-stage mineralization of this deposit.展开更多
The genus and species Yuyuanozoon magnificissimi gen. et sp. nov., a new fossil vetulicolian, is reported from the Early Cambrian Chengjiang Fauna in Yunnan of China. It has a bipartite body plan and five pairs of cha...The genus and species Yuyuanozoon magnificissimi gen. et sp. nov., a new fossil vetulicolian, is reported from the Early Cambrian Chengjiang Fauna in Yunnan of China. It has a bipartite body plan and five pairs of chain-formed gill sacs, showing the general characteristics of Ventulicolia. However, the exclusive 'atrial cavity' and external gill observed indicate that the new form is different from those previously described as vetulicolians, probably representing a lineage developed within deuterostomes and more primitive than urochordates.展开更多
A current-turbidity monitoring system (CTMS) was deployed on the intertidal flat at Wanggang, northern Jiangsu during October 16-17, 2000, to measure the tidal current speeds and seawater turbidities at 5 levels above...A current-turbidity monitoring system (CTMS) was deployed on the intertidal flat at Wanggang, northern Jiangsu during October 16-17, 2000, to measure the tidal current speeds and seawater turbidities at 5 levels above the seabed. Based upon the logarithmic-profile equation, the boundary layer parameters, i.e., u, z0 and C60, were obtained for 247 tidal flow velocity profiles. Around 90% of the profiles were logarithmic according to the critical correlation coefficient. Internal consistency analysis shows that these parameters derived by different methods are consistent with each other. In addition, the height of the bedforms observed is close to the seabed roughness lengths calculated from the velocity profiles, indicating that the boundary layer parameters obtained can reveal the conditions at the sediment-water interface on the intertidal flats. Suspended sediment concentrations were obtained from the 5 CTMS turbidity meters using laboratory and in-situ calibrations. The results show that the in-situ calibrated SSCs have a much higher accuracy than the laboratory calibrated ones. Calculation of suspended sediment fluxes on the intertidal flats, with a magnitude of 104 kg/m per spring tidal cycle, indicates that suspended sediment moves towards the northwest, which is reversal to the transport pattern controlled by the southward Northern Jiangsu Coastal Current in the sub-tidal zone and adjacent shallow waters.展开更多
AIM: To obtain an efficient delivery system for transportingendostatin gene to mouse liver tumor xenografts byadministration of aerosol.METHODS: Recombinant plasmid pcDNA3.0/endostatincontaining human endostatin gene ...AIM: To obtain an efficient delivery system for transportingendostatin gene to mouse liver tumor xenografts byadministration of aerosol.METHODS: Recombinant plasmid pcDNA3.0/endostatincontaining human endostatin gene together with signalpeptide from alkaline phosphatase were transferred intohuman umbilical vein endothelial cell (HUVEC) by transfenin(TF)-liposome-endostatin complex. Western blot was usedto detect the expression of human endostatin in transfectedHUVEC cells and its medium. After the tumor-bearing micewere administrated with TF-liposome-endostatin complex,the lung tissue was analyzed by immunohistochemicalmethod for expression of endostatin and the tumors weretreated with CD-31 antibody to detect the density ofmicrovesseles in tumor tissues. The inhibition of tumorgrowth was estimated by the weight of tumors from groupstreated with different dos es of TF-liposome-endostatincomplex. DNA fragmentation assay was used to detect theapoptosis of the cells from primary liver tumor.RESULTS: Western blot analysis and immunohistochemicalmethod confirmed the expression of endostatin proteininvitro and in vivo. After the tumor sections were treated withCD-31 antibody, the positive reaction cells appeared brownwhile the negative cells were colorless. The positively stainedarea of the TF-liposome-endostatin treated group wassignificantly smaller (P<0.01, 645.8+55.2 μm2) than that ofthe control group (1325.4+198.5 μm2). The data showed asignificant inhibition of angiogenesis. After administrationof TF-liposome-endostatin, comparing with the control groupadministrated with TF-liposome-pcDNA3.0, liver tumorgrowth in the mice treated with 50, 250 and 500 mg DNA/kg was inhibited by 36.6 %, 40.8 %, and 72.8 %, respectively(P<0.01). And a typical DNA fragmentation of apoptosis wasfound in the cells from tumor tissues of the mice treatedwith TF-liposome-endostatin but none in the control group.CONCLUSION: Endostatin gene could be efficientlytransported into the mice with TF-liposome-DNA deliverysystem by administration of aerosol. TF-liposome-mediatedendostatin gene therapy strongly inhibited angiogenesis andthe growth of mouse xenograft liver tumors. It also couldpromote the development of apoptosis of tumors withoutdirect influence on tumor cells.展开更多
Atmospheric sulfur deposition onto typical farmland in East China was investigated using both field measurements and numerical modeling. The field measurements were conducted at the Experiment Station of Red Soil Ecol...Atmospheric sulfur deposition onto typical farmland in East China was investigated using both field measurements and numerical modeling. The field measurements were conducted at the Experiment Station of Red Soil Ecology, Chinese Academy of Sciences, 10 km from Yingtan, Jiangxi Province, East China, between November 1998 and October 1999, and at the Changshu Ecological Experiment Station, Chinese Academy of Sciences, in a rapidly developing region of Jiangsu Province, East China, between April 2001 and Marc…展开更多
Ore textures and electron microprobe analyses show that in addition to highly scattered blebs in sphalerite grains, intergrown chalcopyrite also occurs as reds, myrrmekites andlamellae aligned along cleavages and twin...Ore textures and electron microprobe analyses show that in addition to highly scattered blebs in sphalerite grains, intergrown chalcopyrite also occurs as reds, myrrmekites andlamellae aligned along cleavages and twin boundaries of the host sphalerite. The majority of theintergrowths could have been formed by replacement of sphalerite by chalcopyrite, albeit part ofthem may have resulted from exsolution. Not only copper, but also iron were introduced intothe sphalerite by replacive fluids.While the front of the replacing fluid was moving forward through a sulphide orebody, Znand Pb were dissolved and Cu was precipitated, resulting in zonal refining of the sulphide ores.The remobilized zinc and lead were precipitated at favourable sites with changed physiccrchemical conditions. This is a Possible mechanism for the formation of copper-poor zinc and lead oresabove or lateral to the copper orebodies in some of the massive sulphide deceits reworked andoverprinted by late-stage granites and their hydrothermal fluids.展开更多
With the rapid development of mechanical equipment, the mechanical health monitoring field has entered the era of big data. However, the method of manual feature extraction has the disadvantages of low efficiency and ...With the rapid development of mechanical equipment, the mechanical health monitoring field has entered the era of big data. However, the method of manual feature extraction has the disadvantages of low efficiency and poor accuracy, when handling big data. In this study, the research object was the asynchronous motor in the drivetrain diagnostics simulator system. The vibration signals of different fault motors were collected. The raw signal was pretreated using short time Fourier transform (STFT) to obtain the corresponding time-frequency map. Then, the feature of the time-frequency map was adap- tively extracted by using a convolutional neural network (CNN). The effects of the pretreatment method, and the hyper parameters of network diagnostic accuracy, were investigated experimentally. The experimental results showed that the influence of the preprocessing method is small, and that the batch-size is the main factor affecting accuracy and training efficiency. By investigating feature visualization, it was shown that, in the case of big data, the extracted CNN features can represent complex mapping relationships between signal and health status, and can also overcome the prior knowledge and engineering experience requirement for feature extraction, which is used by tra- ditional diagnosis methods. This paper proposes a new method, based on STFT and CNN, which can complete motor fault diagnosis tasks more intelligently and accurately.展开更多
In China, accelerating industrialization and urbanization followinghigh-speed economic development and population increases have greatly impacted land use/coverchanges, making it imperative to obtain accurate and up t...In China, accelerating industrialization and urbanization followinghigh-speed economic development and population increases have greatly impacted land use/coverchanges, making it imperative to obtain accurate and up to date iufbimation on changes soas toevaluate their environmental effects. The major purpose of this study was to develop a new method tofuse lower spatial resolution multispectral satellite images with higher spatial resolutionpanchromatic ones to assist in land use/cover mapping.An algorithm of a new fusion method known asedge enhancement intensity modulation (EEIM) was proposed to merge two optical image data sets ofdifferent spectral ranges. The results showed that the EEIM image was quite similar in color tolower resolution multispectral images, and the fused product was better able to preserve spectralinformation. Thus, compared to conventional approaches, the spectral distortion of the fused imageswas markedly reduced. Therefore, the EEIM fusion method could be utilized to fuse remote sensingdata from the same or different sensors, including TM images and SPOT5 panchromatic images,providing high quality land use/cover images.展开更多
Vibration acceleration signals are often measured from case surface of arunning machine to monitor its condition. If the measured vibration signals display to have periodicimpulse components with a certain frequency, ...Vibration acceleration signals are often measured from case surface of arunning machine to monitor its condition. If the measured vibration signals display to have periodicimpulse components with a certain frequency, there may exist a corresponding local fault in themachine, and if further extracting the periodic impulse components from the vibration signals, theseverity of the local fault can be estimated and tracked. However, the signal-to-noise ratios (SNRs)of the vibration acceleration signals are often so small that the periodic impulse components aresubmersed in much background noises and other components, and it is difficult or inconvenient for usto detect and extract the periodic impulse components with the current common analyzing methods forvibration signals. Therefore, another technique, called singular value decomposition (SVD), istried to be introduced to solve the problem. First, the principle of detecting and extracting thesignal periodic components using singular value decomposition is summarized and discussed. Second,the infeasibility of the direct use of the existing SVD based detecting and extracting approach ispointed out. Third, the approach to construct the matrix for SVD from the signal series is improvedlargely, which is the key program to improve the SVD technique; Other associated improvement is alsoproposed. Finally, a simulating application example and a real-life application example ondetecting and extracting the periodic impulse components are given, which showed that the introducedand improved SVD technique is feasible.展开更多
文摘AIM: To investigate the protective effect of ketamine on the endotoxin-induced proinflammatory cytokines and NFkappa B activation in the intestine. ETHODS: Adult male Wistar rats were randomly divided into 6 groups: (a) normal saline control, (b) challenged with endotoxin (5 mg/kg) and treated by saline, (c) challenged with endotoxin (5 mg/kg) and treated by ketamine (0.5 mg/kg), (d) challenged with endotoxin (5 mg/kg) and treated by ketamine (5 mg/kg ), (e) challenged with endotoxin (5 mg/kg) and treated by ketamine (50 mg/kg), and (f) saline injected and treated by ketamine (50 mg/kg). After 1, 4 or 6 h, TNF-α and IL-6 mRNA were investigated in the tissues of the intestine (jejunum) by RT-PCR. TNF-α and IL-6 were measured by ELISA. We used electrophoretic mobility shift assay (EMSA) to investigate NF-kappa B activity in the intestine. RESULTS: NF-kappa B activity, the expression of TNF-α and IL-6 were enhanced in the intestine by endotoxin. Ketamine at a dose of 0.5 mg/kg could suppress endotoxininduced TNF-α mRNA and protein elevation and inhibit NFkappa B activation in the intestine. However the least dosage of ketamine to inhibit IL-6 was 5 mg/kg in our experiment. CONCLUSION: Ketamine can suppress endotoxin-induced production of proinflammatory cytokines such as TNF-α and IL-6 production in the intestine. This suppressive effect may act through inhibiting NF-kappa B.
基金Supported by the Scientific Research Foundation of the Chinese PLA Key Medical Programs during the 10~(th) Five-Year Plan Period,No.01Z011
文摘AIM:To study the alterations of brain-gut peptides following traumatic brain injury (TBI) and to explore the underlying significance of these peptides in the complicated gastrointestinal dysfunction.METHODS:Rat models of focal traumatic brain injury were established by impact insult method,and divided into 6 groups (6 rats each group) including control group with sham operation and TBI groups at postinjury 3,12,24,72h,and d 7.Blood and proximal jejunum samples were taken at time point of each group and gross observations of gastrointestinal pathology were recorded simultaneously.The levels of vasoactive intestinal peptide (VIP) in plasma,calcitonin gene-related peptide (CGRP) and cholecystokinin (CCK) in both plasma and jejunum were measured by enzyme immunoassay (EIA). Radioimmunoassay (RIA) was used to determine the levels of VIP in jejunum.RESULTS:Gastric distension,delayed gastric emptying and intestinal dilatation with a large amount of yellowish effusion and thin edematous wall were found in TBI rats through 12h and 72h, which peaked at postinjury 72h. As compared with that of control group (247.8±29.5ng/L), plasma VIP levels were significantly decreased at postinjury 3,12 and 24h (106.7±34.1ng/L, 148.7±22.8ng/L,132.8±21.6ng/L,respectively),but significantly increased at 72h (405.0±29.8ng/L) and markedly declined on d 7 (130.7±19.3ng/L).However,Plasma levels CCK and CGRP were significantly increased through 3h and 7d following TBI (126-691% increases),with the peak at 72 h.Compared with control (VIP, 13.6±1.4ng/g;CGRP,70.6±17.7ng/g);VIP and CGRP levels in jejunum were significantly increased at 3h after TBI (VIP,35.4±5.0ng/g;CGRP,103.8±22.1ng/g),and declined gradually at 12 h and 2d h (VIP,16.5±1.8ng/g,5.5±1.4ng/g;CGRP,34.9±9.7ng/g, 18.5±7.7ng/g),but were significantly increased again at 72 h (VIP, 48.7±9.5ng/g; CGRP,142.1±24.3ng/g),then declined in various degrees on d 7 (VIP, 3.8±1.1ng/g; CGRP, 102.5±18.1ng/g).The CCK levels in jejunum were found to change in a similar trend as that in plasma with the concentrations of CCK significantly increased following TBI (99-517% increases) and peaked at 72h.CONCLUSION:Traumatic brain injury can lead to significant changes of brain-gut peptides in both plasma and small intestine, which may be involved in the pathogenesis of complicated gastrointestinal dysfunction.
基金grants from the Health Department of General Logistics Department of People's Liberation Army,China,No 01Z011
文摘AIM: To determine the least invasive surgical procedure by comparing the levels of operative stress hormones, responsereactive protein (CRP) and rest energy expenditure (REE)after laparoscopic (LC) and open cholecystectomy (OC).METHODS: Twenty-six consecutive patients with noncomplicated gallstones were randomized for LC (14) and OC (12). Plasma concentrations of somatotropin, insulin, cortisol and CRP were measured. The levels of REE were determined.RESULTS: In the third postoperative day, the insulin levels were lower compared to that before operation (P<0.05).Tn the first postoperative day, the levels of somatotropin and cortisol were higher in OC than those in LC. After operation the parameters of somatotropin, CRP and cortisol increased, compared to those in the preoperative period in the all patients (P<0.05). In the all-postoperative days,the CRP level was higher in OC than that in LC (7.46±0.02;7.38±0.01, P<0.05). After operation the REE level all increased in OC and LC (P<0.05). In the all-postoperative days, the REE level was higher in OC than that in LC (1438.5±A18.5;1222.3±L80.8, P<0.05).CONCLUSION: LC results in less prominent stress response and smaller metabolic interference compared to open surgery. These advantages are beneficial to the restoration of stress hormones, the nitrogen balance, and the energy metabolism. However, LC can also induce acidemia and pulmonary hypoperfusion because of the penumoperitonium it uses during surgery.
基金Project supported by the National Natural Science Foundation of China (Nos. 49831070 and 49973027).
文摘Soil erosion accelerates soil degradation. Some natural soils and cultivated soils on sloping land in southern Jiangsu Province, China were chosen to study soil degradation associated with erosion. Soil erosion intensity was investigated using the 137Cs tracer method. Soil particle-size distribution, soil organic matter (OM), total nitrogen (TN) and total phosphorus (TP) were measured, and the effects of erosion on soil physical and chemical properties were analyzed statistically using SYSTAT8.0. Results indicated that erosion intensity of cultivated soils was greater than that of the natural soils, suggesting that cultivation increased soil loss. Erosion also led to an increase of coarser soil particle proportion, especially in natural soils. In addition, silt was the primary soil particle lost due to erosion. However, in cultivated fields, coarser soil particles over time were attributed not only to soil erosion but also to mechanical eluviation as a result of farming activities. Moreover, erosion caused a decrease in soil OM, TN and TP as well as thinning of the soil layer.
文摘Activated sludge was immobilized into Ca-alginate beads via entrapment, and biosorption of three heavy metal ions, copper(Ⅱ), zinc(Ⅱ), and chromimum(Ⅱ), from aqueous solution in the concentration range of 10\_100 mg/L was studied by using both entrapped activated sludge and inactivated free biomass at pH≤5. A biphasic metal adsorption pattern was observed in all immobilized biomass experiments. The biosorption of metal ions by the biosorbents increased with the initial concentration increased in the medium. The adsorption rate of immobilized pre-treated activated sludge(PAS) was much lower than that of free PAS due to the increase in mass transfer resistance resulting from the polymeric matrix. Biosorption equilibrium of beads was established in about 20 h and the adsorbed heavy metal ions did not change further with time. No significant effect of temperature was observed in the test for free biomass while immobilized PAS appeared to be strong temperature dependent in the test range of 10 and 40℃. Besides, the content of activated sludge in the calcium alginate bead has an influence on the uptake of heavy metals. The sorption equilibrium was well modeled by Langmuir isotherm, implying monomolecular adsorption mechanism. Carboxyl group in cell wall played an important role in surface adsorption of heavy metal ions on PAS.
文摘AIM: To develop an in vitro three-dimensional (3-D) angiogenesis system to analyse the capillary sprouts induced in response to the concentration ranges of basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF) and to quantify their synergistic activity.METHODS: Microcarriers (MCs) coated with human microvascular endothelial cells (HMVECs) were embedded in fibrin gel and cultured in 24-well plates with assay media. The growth factors bFGF, or VEGF, or both were added to the system. The wells (n = 8/group) were digitally photographed and the average length of capillary-like sprouts (ALS) from each microcarrier was quantitated.RESULTS: In aprotinin-stabilized fibrin matrix, human microvascular endothelial cells on the MCs invaded fibrin,forming sprouts and capillary networks with lumina. The angiogenic effects of bFGF or VEGF were dose-clependent in bhe range from 10 to 40 ng/mL. At d 1, 10 ng/mL of bFGF and VEGF induced angiogenesis with an ALS of 32.13±16.6 μm and 43.75±27.92 μm, respectively, which were significantly higher than that of the control (5.88±4.45 μm, P<0.01),and the differences became more significant as the time increased. In addition, the combination of 10 ng/mL of bFGF and VEGF each induced a more significant effect than the summed effects of bFGF (10 ng/mL) alone and VEGF (10 ng/mL) alone when analyzed using SPSS system for general linear model (GLM) (P= 0.011), and bhat also exceeded the effects by 20 ng/mL of either bFGF or VEGF.CONCLUSION: A microcarrier-based in vitro threedimensional angiogenesis model can be developed in fibrin.It offers a unique system for quantitative analysis of angiogenesis. Both bFGF and VEGF exert their angiogenic effects on HMVECs synergistically and in a dose-dependent manner.
基金supports from the National 973 Project on western China No.2001CB409804the key project of National Natural Science Foundation of China No.49832040.
文摘Studies show that the Tianshan orogenic belt was built in the late stage of the Paleozoic, as evidenced by the Permian red molasses and foreland basins, which are distributed in parallel with the Tianshan belt, indicating that an intense folding and uplifting event took place. During the Triassic, this orogenic belt was strongly eroded, and basins were further developed. Starting from the Jurassic, a within-plate regional extension occurred, forming a series of Jurassic-Paleogene extensional basins in the peneplaned Tianshan region. Since the Neogene, a collision event between the Indian and the Eurasian plates that took place on the southern side of the Tianshan belt has caused a strong intra-continental orogeny, which is characterized by thrusting and folding. Extremely thick coarse conglomerate and sandy conglomerate of the Xiyu Formation of Neogene System were accumulated unconformably on the Tianshan piedmont. Studies have revealed that the strong compression caused by the Indian-Eurasian collision had a profound influence over the orogenic belt in the hinterland, and MesozoiC-Cenozoic brittle deformed structures superposed on the ductile deformed Paleozoic rocks. The Mesozoic extensional basins were converted into Cenozoic compressional basins. The deformation in the basins is featured by step thrusts and fault-related folds. Statistics of joints show that the principal compressive stress since the Neogene is in a N-S direction. Meanwhile, owing to the underthrusting of the basin toward the orogenic belt, the Paleozoic strata were thrust on the Meso-Cenozoic rocks as tectonic slices, revealing distinct kinematic features in different geologic units. The basin-range coupling zones are characterized by intensive compression, folding and thrusting, accompanied by local sub-E-W-trending strike-slip faults. In the Tianshan region, Cenozoic thrusting is the most common basin-range coupling mode. The folding and faulting of Mesozoic sedimentary rocks, spontaneous combustion of Jurassic coal layers and formation of sintered rocks, the Cenozoic earthquakes and active faulting, and the unique mosaic pattern of basin-range framework of Xinjiang are all products of tectonism since the Neogene.
基金the Scientific Research Foundation of the Chinese PLA Key Medical Programs during the 10th Five-Year Plan Period,No.01Z011
文摘AIM: Gastrointestinal dysfunction is a common complication in patients with traumatic brain injury (TBI). However, the effect of traumatic brain injury on intestinal mucosa has not been studied previously. The aim of the current study was to explore the alterations of intestinal mucosa morphology and barrier function, and to determine how rapidly the impairment of gut barrier function occurs and how long it persists following traumatic brain injury.METHODS: Male Wistar rats were randomly divided into six groups (6 rats each group) including controls without brain injury and traumatic brain injury groups at hours 3,12, 24, and 72, and on day 7. The intestinal mucosa structure was detected by histopathological examination and electron microscopy. Gut barrier dysfunction was evaluated by detecting serum endotoxin and intestinal permeability. The level of serum endotoxin and intestinal permeability was measured by using chromogenic limulus amebocyte lysate and lactulose/mannitol (L/M) ratio, respectively.RESULTS: After traumatic brain injury, the histopathological alterations of gut mucosa occurred rapidly as early as 3 hours and progressed to a serious state, including shedding of epithelial cells, fracture of villi, focal ulcer, fusion of adjacent villi, dilation of central chyle duct, mucosal atrophy,and vascular dilation, congestion and edema in the villous interstitium and lamina propria. Apoptosis of epithelial cells,fracture and sparseness of microvilli, loss of tight junction between enterocytes, damage of mitochondria and endoplasm, were found by electron microscopy. The villous height, crypt depth and surface area in jejunum decreased progressively with the time of brain injury. As compared with that of control group (183.7±41.8 EU/L), serum endotoxin level was signnificantly increased at 3, 12, and 24 hours following TBI (434.8±54.9 EU/L, 324.2±61.7 EU/L and 303.3±60.2 EU/L, respectively), and peaked at 72 hours (560.5±76.2 EU/L), then declined on day 7 (306.7±62.4 EU/L,P<0.0L). Two peaks of serum endotoxin level were found at hours 3 and 72 following TBI. L/M ratio was also significantly higher in TBI groups than that in control group (control,0.0172±0.0009; 12 h, 0.0303±0.0013; 24 h, 0.0354±0.0025;72 h, 0.0736±0.0105; 7 d, 0.0588±0.0083; P<0.01).CONCLUSION: Traumatic brain injury can induce significant damages of gut structure and impairment of barrier function which occur rapidly as early as 3 hours following brain injury and lasts for more than 7 days with marked mucosal atrophy.
基金Supported by Scientific Research Foundation of the Chinese PLA Key Medical Programs During the 10th Five-Year Plan Period, No. 01Z011
文摘AIM: Nuclear factor kappa B (NF-κB) regulates a large number of genes involved in the inflammatory response to critical illnesses, but it is not known if and how NF-KB is activated and intercellular adhesion molecule-1 (ICAM-1) expressed in the gut following traumatic brain injury (TBI). The aim of current study was to investigate the temporal pattern of intestinal NF-κB activation and ICAM-1 expression following TBI. METHODS: Male Wistar rats were randomly divided into six groups (6 rats in each group) including controls with sham operation and TBI groups at hours 3, 12, 24, and 72, and on d 7. Parietal brain contusion was adopted using weight-dropping method. All rats were decapitated at corresponding time point and mid-jejunum samples were taken. NF-KB binding activity in jejunal tissue was measured using EMSA. Immunohistochemistry was used for detection of ICAM-1 expression in jejunal samples. RESULTS: There was a very low NF-κB binding activity and little ICAM-1 expression in the gut of control rats after sham surgery. NF-KB binding activity in jejunum significantly increased by 160% at 3 h following TBI (P<0.05 vs control), peaked at 72 h (500% increase) and remained elevated on d 7 post-injury by 390% increase. Compared to controls, ICAM-1 was significantly up-regulated on the endothelia of microvessels in villous interstitium and lamina propria by 24 h following TBI and maximally expressed at 72 h post-injury (P<0.001). The endothelial ICAM-1 immunoreactivity in jejunal mucosa still remained strong on d 7 post-injury. The peak of NF-κB activation and endothelial ICAM-1 expression coincided in time with the period during which secondary mucosal injury of the gut was also at their culmination following TBI. CONCLUSION: TBI could induce an immediate and persistent up-regulation of NF-κB activity and subsequent up-regulation of ICAM-1 expression in the intestine. Inflammatory response mediated by increased NF-κB activation and ICAM-1 expression may play an important role in the pathogenesis of acute gut mucosal injury following TBI.
文摘AIM: To determine the effects of total parenteral nutrition and somatostatin on patients with chylous ascites.METHODS: Five patients were diagnosed with chylous ascites on the basis of laboratory findings of ascites sample from Nov 1999 to May 2003. Total parenteral nutrition and somatostatin or its analogue was administered to 4 patients,while the other one only received total parenteral nutrition.All the patients had persistent peritoneal drainage, with the quantity and quality of drainage fluid observed daily.Necessary supportive treatments were given to the patients individually during the therapy.RESULTS: Two of 4 patients who received somatostatin therapy obtained complete recovery within 10 d without any recurrence while on a normal diet. In these 2 patients,the peritoneal drainage reduced to zero in one and the other's decreased from 2 000 mL to 80 mL with a clear appearance and negative qualitative analysis of chyle. Recurrent chylous ascites, though relieved effectively by the same method every time, developed in one patient with advanced pancreatic cancer. The other patient's lymphatic fistula was blocked with the fibrin glue after conservative treatment. The patient who only received total parenteral nutrition was cured 24 d after therapy.CONCLUSION: Total parenteral nutrition along with somatostatin can relieve the symptoms and close the fistula in patients with chylous ascites rapidly. It appears to be an effective therapy available for the treatment of chylous ascites caused by various disorders.
基金the National Natural Science Foundation of China (No. 49831070) and by the KeyProgramme of the Ministry of Land and Resources
文摘As one of the developing countries China has an arable land per capita far below the world’s average level. With a high-density population and the quick development of economy and urbanization, the Yangtze River Delta shows the typical characteristics of land use in developed regions of China, which are: high land reclamation rate and low arable land per capita; intensive land use and high output value; and rapid increasing of construction land area and fast diminishing of arable lands. The analysis indicates that the process of the arable land changes in the Yangtze River Delta could be divided into four different change stages over the past 50 years.
基金supported by the National Science Foundation of China(grant Nos.49873016,40221301)the Ph.D.Programs Foundation of the Ministry of Education of China(No.20020284035)
文摘An important diplogenetic mineralization event superimposed on pre-existing exhalation sediments in the Tongling area, Anhui province, was triggered by widespread granitic magmatism along the northeastern margin of the Yangtze Block during 140–135 Ma under extensional tectonic circumstances following the collision between the North China and Yangtze blocks. The main orebodies of the Dongguashan copper deposit, a typical diplogenetic stratified deposit among many polymetallic ore deposits in China, are hosted by strata between Upper Devonian sandstone and Carboniferous limestone, and its mineralization was genetically related to the Qingshanjiao intrusive. The Rb-Sr isotopic isochron of the Qingshanjiao intrusive yields an age of about 136.5±1.4 Ma. The ore-forming fluid reflected by the inclusion fluid in quartz veins is characterized by high temperature and high salinity, and its age was also determined by Rb -Sr isotope dating as 134±11 Ma. Oxygen and hydrogen isotope composition data suggest that the ore-forming fluid was derived mainly from magmatism. By integrating these isotopic dating data, characteristics of fluid inclusions and the geology of the deposit, the mineralization of the Dongguashan copper deposit is divided into two stages. First, a stratiform sedimentary deposit or protore layer formed in the Late Devonian to the Early Carboniferous, while in the second stage the pre-existing protore was superimposed by hydrothermal fluid that was derived from the Yanshanian magmatic activities occurring around 135 Ma ago. This two-stage mineralization formed the Dongguashan statiform copper deposit. Associated “porphyry” mineralization found in the bottom of and in surrounding intrusive rocks of the orebodies might have occurred in the same period as a second-stage mineralization of this deposit.
基金supported by the National Natural Science Foundation of China(Grants 40073007,40173002,40232020)the Natural Scienee Foundation of Yunnan Province(Grant 97D007Z)
文摘The genus and species Yuyuanozoon magnificissimi gen. et sp. nov., a new fossil vetulicolian, is reported from the Early Cambrian Chengjiang Fauna in Yunnan of China. It has a bipartite body plan and five pairs of chain-formed gill sacs, showing the general characteristics of Ventulicolia. However, the exclusive 'atrial cavity' and external gill observed indicate that the new form is different from those previously described as vetulicolians, probably representing a lineage developed within deuterostomes and more primitive than urochordates.
文摘A current-turbidity monitoring system (CTMS) was deployed on the intertidal flat at Wanggang, northern Jiangsu during October 16-17, 2000, to measure the tidal current speeds and seawater turbidities at 5 levels above the seabed. Based upon the logarithmic-profile equation, the boundary layer parameters, i.e., u, z0 and C60, were obtained for 247 tidal flow velocity profiles. Around 90% of the profiles were logarithmic according to the critical correlation coefficient. Internal consistency analysis shows that these parameters derived by different methods are consistent with each other. In addition, the height of the bedforms observed is close to the seabed roughness lengths calculated from the velocity profiles, indicating that the boundary layer parameters obtained can reveal the conditions at the sediment-water interface on the intertidal flats. Suspended sediment concentrations were obtained from the 5 CTMS turbidity meters using laboratory and in-situ calibrations. The results show that the in-situ calibrated SSCs have a much higher accuracy than the laboratory calibrated ones. Calculation of suspended sediment fluxes on the intertidal flats, with a magnitude of 104 kg/m per spring tidal cycle, indicates that suspended sediment moves towards the northwest, which is reversal to the transport pattern controlled by the southward Northern Jiangsu Coastal Current in the sub-tidal zone and adjacent shallow waters.
基金Jiangsu Natural Science Fund(China),BK20000001the National Natural Science Foundation of China,30070250the"985 Project"from Nanjing University
文摘AIM: To obtain an efficient delivery system for transportingendostatin gene to mouse liver tumor xenografts byadministration of aerosol.METHODS: Recombinant plasmid pcDNA3.0/endostatincontaining human endostatin gene together with signalpeptide from alkaline phosphatase were transferred intohuman umbilical vein endothelial cell (HUVEC) by transfenin(TF)-liposome-endostatin complex. Western blot was usedto detect the expression of human endostatin in transfectedHUVEC cells and its medium. After the tumor-bearing micewere administrated with TF-liposome-endostatin complex,the lung tissue was analyzed by immunohistochemicalmethod for expression of endostatin and the tumors weretreated with CD-31 antibody to detect the density ofmicrovesseles in tumor tissues. The inhibition of tumorgrowth was estimated by the weight of tumors from groupstreated with different dos es of TF-liposome-endostatincomplex. DNA fragmentation assay was used to detect theapoptosis of the cells from primary liver tumor.RESULTS: Western blot analysis and immunohistochemicalmethod confirmed the expression of endostatin proteininvitro and in vivo. After the tumor sections were treated withCD-31 antibody, the positive reaction cells appeared brownwhile the negative cells were colorless. The positively stainedarea of the TF-liposome-endostatin treated group wassignificantly smaller (P<0.01, 645.8+55.2 μm2) than that ofthe control group (1325.4+198.5 μm2). The data showed asignificant inhibition of angiogenesis. After administrationof TF-liposome-endostatin, comparing with the control groupadministrated with TF-liposome-pcDNA3.0, liver tumorgrowth in the mice treated with 50, 250 and 500 mg DNA/kg was inhibited by 36.6 %, 40.8 %, and 72.8 %, respectively(P<0.01). And a typical DNA fragmentation of apoptosis wasfound in the cells from tumor tissues of the mice treatedwith TF-liposome-endostatin but none in the control group.CONCLUSION: Endostatin gene could be efficientlytransported into the mice with TF-liposome-DNA deliverysystem by administration of aerosol. TF-liposome-mediatedendostatin gene therapy strongly inhibited angiogenesis andthe growth of mouse xenograft liver tumors. It also couldpromote the development of apoptosis of tumors withoutdirect influence on tumor cells.
文摘Atmospheric sulfur deposition onto typical farmland in East China was investigated using both field measurements and numerical modeling. The field measurements were conducted at the Experiment Station of Red Soil Ecology, Chinese Academy of Sciences, 10 km from Yingtan, Jiangxi Province, East China, between November 1998 and October 1999, and at the Changshu Ecological Experiment Station, Chinese Academy of Sciences, in a rapidly developing region of Jiangsu Province, East China, between April 2001 and Marc…
文摘Ore textures and electron microprobe analyses show that in addition to highly scattered blebs in sphalerite grains, intergrown chalcopyrite also occurs as reds, myrrmekites andlamellae aligned along cleavages and twin boundaries of the host sphalerite. The majority of theintergrowths could have been formed by replacement of sphalerite by chalcopyrite, albeit part ofthem may have resulted from exsolution. Not only copper, but also iron were introduced intothe sphalerite by replacive fluids.While the front of the replacing fluid was moving forward through a sulphide orebody, Znand Pb were dissolved and Cu was precipitated, resulting in zonal refining of the sulphide ores.The remobilized zinc and lead were precipitated at favourable sites with changed physiccrchemical conditions. This is a Possible mechanism for the formation of copper-poor zinc and lead oresabove or lateral to the copper orebodies in some of the massive sulphide deceits reworked andoverprinted by late-stage granites and their hydrothermal fluids.
基金Supported by National Natural Science Foundation of China(Grant No.51405241,51505234,51575283)
文摘With the rapid development of mechanical equipment, the mechanical health monitoring field has entered the era of big data. However, the method of manual feature extraction has the disadvantages of low efficiency and poor accuracy, when handling big data. In this study, the research object was the asynchronous motor in the drivetrain diagnostics simulator system. The vibration signals of different fault motors were collected. The raw signal was pretreated using short time Fourier transform (STFT) to obtain the corresponding time-frequency map. Then, the feature of the time-frequency map was adap- tively extracted by using a convolutional neural network (CNN). The effects of the pretreatment method, and the hyper parameters of network diagnostic accuracy, were investigated experimentally. The experimental results showed that the influence of the preprocessing method is small, and that the batch-size is the main factor affecting accuracy and training efficiency. By investigating feature visualization, it was shown that, in the case of big data, the extracted CNN features can represent complex mapping relationships between signal and health status, and can also overcome the prior knowledge and engineering experience requirement for feature extraction, which is used by tra- ditional diagnosis methods. This paper proposes a new method, based on STFT and CNN, which can complete motor fault diagnosis tasks more intelligently and accurately.
基金Project supported by the Knowledge Innovation Program of Chinese Academy of Sciences (No. KZCX3-SW-427), the National Key Basic Research Support Foundation of China (NKBRSF) (No. 2002CB410810) and the China Scholarship Council (No. 2003836044).
文摘In China, accelerating industrialization and urbanization followinghigh-speed economic development and population increases have greatly impacted land use/coverchanges, making it imperative to obtain accurate and up to date iufbimation on changes soas toevaluate their environmental effects. The major purpose of this study was to develop a new method tofuse lower spatial resolution multispectral satellite images with higher spatial resolutionpanchromatic ones to assist in land use/cover mapping.An algorithm of a new fusion method known asedge enhancement intensity modulation (EEIM) was proposed to merge two optical image data sets ofdifferent spectral ranges. The results showed that the EEIM image was quite similar in color tolower resolution multispectral images, and the fused product was better able to preserve spectralinformation. Thus, compared to conventional approaches, the spectral distortion of the fused imageswas markedly reduced. Therefore, the EEIM fusion method could be utilized to fuse remote sensingdata from the same or different sensors, including TM images and SPOT5 panchromatic images,providing high quality land use/cover images.
基金This project is supported by National Natural Science Foundation of China (No.59905011, 60275041).
文摘Vibration acceleration signals are often measured from case surface of arunning machine to monitor its condition. If the measured vibration signals display to have periodicimpulse components with a certain frequency, there may exist a corresponding local fault in themachine, and if further extracting the periodic impulse components from the vibration signals, theseverity of the local fault can be estimated and tracked. However, the signal-to-noise ratios (SNRs)of the vibration acceleration signals are often so small that the periodic impulse components aresubmersed in much background noises and other components, and it is difficult or inconvenient for usto detect and extract the periodic impulse components with the current common analyzing methods forvibration signals. Therefore, another technique, called singular value decomposition (SVD), istried to be introduced to solve the problem. First, the principle of detecting and extracting thesignal periodic components using singular value decomposition is summarized and discussed. Second,the infeasibility of the direct use of the existing SVD based detecting and extracting approach ispointed out. Third, the approach to construct the matrix for SVD from the signal series is improvedlargely, which is the key program to improve the SVD technique; Other associated improvement is alsoproposed. Finally, a simulating application example and a real-life application example ondetecting and extracting the periodic impulse components are given, which showed that the introducedand improved SVD technique is feasible.