The effect of weak light on the peroxidation of membrane_lipid of one_year_old cherries ( Prunus pseudocerasus L. 'Laiyang') was studied by whole_tree shading. The results showed that the net photosynthetic...The effect of weak light on the peroxidation of membrane_lipid of one_year_old cherries ( Prunus pseudocerasus L. 'Laiyang') was studied by whole_tree shading. The results showed that the net photosynthetic rate of cherry leaves under weak light was remarkably lower; the activity peroxidase (POD) increased when light intensity decreased; the activity of catalase (CAT) showed an opposite trend, and it was positively correlated with light intensity; the activity of superoxide dismutase (SOD) increased under 366 μmol·m -2 ·s -1 and 533.8 μmol·m -2 ·s -1 light intensity, but decreased under 228.8 μmol·m -2 ·s -1 and 83.9 μmol·m -2 ·s -1 light intensity. A remarkable increase of malondialdehyde (MDA), a product of membrane_lipid peroxidation, was also observed in cherry leaves when treated with weak light, indicating more serious peroxidation in the membrane.展开更多
Sulphur dioxide (SO 2 ) mixed with carrier gases was used as an alternative to SF 6 to protect molten magnesium alloys. The protection behavior of AZ91D alloy in a sealed melting furnace was investigated under the a...Sulphur dioxide (SO 2 ) mixed with carrier gases was used as an alternative to SF 6 to protect molten magnesium alloys. The protection behavior of AZ91D alloy in a sealed melting furnace was investigated under the atmosphere containing SO 2 with different mixed gases. The morphology and composition of the surface film were studied. The melt was well protected in an atmosphere of SO 2 and a proper amount of air, and was not protected properly in the other atmospheres. Based on the understanding of the protective effects of SO 2 in the sealed furnace, the protection mechanism of SO 2 -containing cover gases on molten AZ91D alloy was studied in an open melting furnace. The cover gas protected the melt by reacting with the melt to form a coherent protective film with a network structure on the melt surface. The film contains MgO and MgS. MgS increases the Pilling and Bedworth ratio of the surface film and enhances the protective capability of the films.展开更多
AIM:To study the effect of moxibustion on Zusanli or Liangmeng point on gastric mucosa injury in stress-induced ulcer rats and its correlation with the expression of heat shock protein 70 (HSP70). METHODS:Sixty health...AIM:To study the effect of moxibustion on Zusanli or Liangmeng point on gastric mucosa injury in stress-induced ulcer rats and its correlation with the expression of heat shock protein 70 (HSP70). METHODS:Sixty healthy SD rats (30 males,30 females) were divided into control group,injury model group,Zushanli point group,Liangmeng point group. Stress gastric ulcer model was induced by binding cold stress method. Gastric mucosa ulcer injury (UI) index was calculated by Guth method. Gastric mucosa blood flow (GMBF) was recorded with a biological signal analyzer. Protein content and gene expression in gastric mucosal HSP70 were detected by immunohistochemistry (IHC) and reverse transcription polymerase chain reaction (RT-PCR). Thiobarbital method was used to determine malondialdehyde (MDA) content. Gastric mucosal endothelin (ET) and prostaglandin E2 (PGE2) were analyzed by radioimmunoassay. RESULTS:High gastric mucosal UI index,high HSP70 expression,low GMBF and PGF2,elevated MDA and ET were observed in gastric mucosa of rats subjected to cold stress. Moxibustion on Zusanli or Liangmeng point decreased rat gastric mucosal UI index,MDA and ET. Conversely,the expression of HSP70,GMBF,and PGE2 was elevated in gastric mucosa after pretreatment with moxibustion on Zusanli or Liangmeng point. The observed parameters were significantly different between Zusanli and Liangmeng points. CONCLUSION:Pretreatment with moxibustion on Zusanli or Liangmeng point protects gastric mucosa against stress injury. This protection is associated with the higher expression of HSP70 mRNA and protein,leading to release of PGE2 and inhibition of MDA and ET,impairment of gastric mucosal index.展开更多
Based on a simulative experiment and a comparison analysis, the effect of bivalve Corbiculafluminea activity on sediment-water exchange of dissolved inorganic nitrogen (DIN) is studied. The areas included three inte...Based on a simulative experiment and a comparison analysis, the effect of bivalve Corbiculafluminea activity on sediment-water exchange of dissolved inorganic nitrogen (DIN) is studied. The areas included three intertidal flat sites of the Changjiang (Yangtze) River estuary in China. The interface exchange flux of ammonium, nitrate and nitrite in the short experiment (6 h) was -46.4-40, -74.8-929.1 and 2.5-14.6 μmol/(m^2·h), respectively. It was found that the burrowing activities of C. fluminea increased NH4 and NOi release from sediments to overlying water in the short-term experiment. During long-term incubation, NH4 and NOi released in turn from the sediments. At the beginning of incubation, bioturbation by C. fluminea could accelerate NH2 release from sediments 2-17 times in different sites, resulting in stronger nitrification and increased NOi concentrations in the overlying water. Sediment profile analysis post-incubation shows that organic matter mineralization and sediment-water NH4 exchange had been stimulated by C. fluminea bioturbation and bioirrigation during the experiment. Therefore, C. fluminea activities such as excretion, burrowing, irrigation and turbation can effectively alter nitrogen dynamics and accelerate and stimulate nitrogen exchange and cycling at the sediment-water interface.展开更多
Magnesium phosphate conversion coating(MPCC)was fabricated on AZ31magnesium alloy for corrosion protection by immersion treatment in a simple MPCC solution containing Mg2+and3PO4?ions.The MPCC on AZ31Mg alloy showed m...Magnesium phosphate conversion coating(MPCC)was fabricated on AZ31magnesium alloy for corrosion protection by immersion treatment in a simple MPCC solution containing Mg2+and3PO4?ions.The MPCC on AZ31Mg alloy showed micro-cracks structure and a uniform thickness with the thickness of about2.5μm after20min of phosphating treatment.The composition analyzed by energy dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy revealed that the coating consisted of magnesium phosphate and magnesium hydroxide/oxide compounds.The MPCC showed a significant protective effect on AZ31Mg alloy.The corrosion current of MPCC was reduced to about3%of that of the uncoated surface and the time for the deterioration process during immersion in0.5mol/L NaCl solution improved from about10min to about24h.展开更多
AIM: To study the protective effect of Astragalus rnernbranaceus on intestinal mucosa reperfusion injury and its mechanism after hemorrhagic shock in rats. METHODS: A total of 32 SD rats were randomly divided into f...AIM: To study the protective effect of Astragalus rnernbranaceus on intestinal mucosa reperfusion injury and its mechanism after hemorrhagic shock in rats. METHODS: A total of 32 SD rats were randomly divided into four groups (n = 8, each group): normal group, model group, low dosage group (treated with 10 g/kg Astragalus membranaceus) and high dosage group (treated with 20 g/kg Astragalus membranaceus). The model of hemorrhagic shock for 60 min and reperfusion for 90 min was established. Therapeutic solution (3 mL) was administrated before reperfusion. At the end of the study, the observed intestinal pathology was analyzed. The blood concentrations of lactic acid (LD), nitric oxide (NO), endothelin-1 (ET-1), malondialdehyde (MDA) and the activity of superoxide dismutase (SOD), glutathione peroxidase (GSH-PX) in intestinal mucosa were determined. RESULTS: The intestinal mucosa pathology showed severe damage in model group and low dosage group, slight damage in high dosage group and no obvious damage in normal group. The Chiu's score in low dose group and high dose group was significantly lower than that in model group. The content of MDA in model group was higher than that in low and high dose groups, while that in high dose group was almost the same as in normal group. The activity of SOD and GSH-PX was the lowest in model group and significantly higher in high dose group than in normal and low dose groups. The concentrations of LD and ET-1 in model group were the highest. The concentrations of NO in model group and low dose group were significantly lower than those in high dose group and normal group. CONCLUSION: High dose Astraga/us membranaeus has much better protective effect on hemorrhagic shockreperfusion injury of intestinal mucosa than low dose Astragalus membranaceus. The mechanism may be that Astragalus membranaceus can improve antioxidative effect and regulate NO/ET level during hemorrhagic reperfusion.展开更多
AIM: To study the protective effect of a natural antioxidant, melatonin, against multistress condition induced lipid peroxidation v/a determination of gastric damage and plasma malondialdehyde (MDA) level by high p...AIM: To study the protective effect of a natural antioxidant, melatonin, against multistress condition induced lipid peroxidation v/a determination of gastric damage and plasma malondialdehyde (MDA) level by high performance liquid chromatography in rats. METHODS: We compared indomethacin-induced gastric damage and MDA plasma level in three groups of rats: unoperated, bile duct ligated and sham-operated and evaluated the role of the melatonin on gastric damage and plasma MDA level. Indomethacin and melatonin were injected intraperitoneally in doses of 50 mg/kg and 20 mg/kg, respectively. Animals were killed 4 h after indomethacin injection. RESULTS: Indomethacin induced more severe gastric damage and plasma MDA level in bile duct ligated animals was significantly higher (3.1±0.04 μmol/L) than sham (2.8±0.04 μmol/L) and unoperated animals (1.4±0.08 μmol/L). Pretreatment with melatonin reduced indomethacin-induced gastric damage and plasma MDA level. CONCLUSION: Considering the results of this study, we suggest that in multistress conditions the intensity of gastric damage and the plasma MDA level are great and melatonin reduces the negative effect of lipid peroxidation and cell damage by oxidative stress in multistress conditions due to its antioxidizing activity.展开更多
The cerium conversion film was applied to improving the corrosion resistance of Mg-Gd-Y-Zr magnesium alloy. The film was electrodeposited on the surface of the Mg-RE alloy in cerium nitrate solution. The compositions ...The cerium conversion film was applied to improving the corrosion resistance of Mg-Gd-Y-Zr magnesium alloy. The film was electrodeposited on the surface of the Mg-RE alloy in cerium nitrate solution. The compositions and morphologies were analyzed by X-ray diffraction(XRD), scanning election microscopy (SEM). The corrosion behaviors of the film were investigated electrochemical impedance spectroscopy (EIS), potentiodynamic polarization tests and immersion tests. The results show that the optimum parameters for electrochemical deposition are as follows: pH 10.0, time 30 min, 50 mmol/L Na2CO3 and temperature 25 ℃ by the designed experiments according to the orthogonal table L(9, 34). The corrosion protection efficiency is dependent on the deposition parameters. The cerium conversion film shows better corrosion protection behavior than chromate conversion film on Mg-Gd-Y-Zr magnesium alloy.展开更多
An explosive blast mitigation alternative has increased the safety of structures by using " catcher" systems. These systems " catch" or repel the failure of the window or in-fill wall pro-tecting l...An explosive blast mitigation alternative has increased the safety of structures by using " catcher" systems. These systems " catch" or repel the failure of the window or in-fill wall pro-tecting life and property from ballistic shards or fragments. They can be designed to be stand-alone in new construction and structural retrofits or used to augment structural hardening tech-niques. Cables, fabrics, and thin gauge sheet steel are examples of catcher systems used in the past. A new and evolving category of catcher systems are based on polymeric materials that can be used for both wall and window upgrades. These products are a proven blast mitigation concept and K&C Protective Technologies Pte Ltd (KCPT) together with Sherwin-Williams(SW) use KCPT′s blast engineering capacity and SW′s material engineering principles to create engineered systems for even greater in-use performance.展开更多
Zn-doped TiO2 (Zn?TiO2) thin films were prepared by the sol?gel method on titanium substrates with heat treatment at different temperatures. The effects of heat treatment temperatures and Zn doping on the structure, p...Zn-doped TiO2 (Zn?TiO2) thin films were prepared by the sol?gel method on titanium substrates with heat treatment at different temperatures. The effects of heat treatment temperatures and Zn doping on the structure, photocathodic protection and photoelectrochemical properties of TiO2 thin films were investigated. It is indicated that the photoelectrical performance of the Zn?TiO2 films is enhanced with the addition of Zn element compared with the pure-TiO2 film and the largest decline by 897 mV in the electrode potential is achieved under 300 °C heat treatment. SEM?EDS analyses show that Zn element is unevenly distributed in Zn?TiO2 films; XRD patterns reveal that the grain size of Zn?TiO2 is smaller than that of pure-TiO2; FTIR results indicate that Zn - O bond forms on Zn?TiO2 surface. Ultraviolet visible absorption spectra prove that Zn?TiO2 shifts to visible light region.Mott?Shottky curves show that the flat-band potential of Zn?TiO2 is more negative and charge carrier density is bigger than that ofpure-TiO2, implying that under the synergy of the width of the space-charge layer, carrier density and flat-band potential, Zn?TiO2 with 300 °C heat treatment displays the best photocathodic protection performance.展开更多
The paper introduced the experience of a case of recurrence of endometrial stromal sarcoma with fertility conservation treatment after full-term delivery. A 24-year-old unmarried patient who, with her increasing amoun...The paper introduced the experience of a case of recurrence of endometrial stromal sarcoma with fertility conservation treatment after full-term delivery. A 24-year-old unmarried patient who, with her increasing amount of menstruation in the late six months, had a mass in her lower-abdominal which was confirmed by B-ultrasonic diagnosis as myometrium mixed mass, was given an enucleation of uterus tumor. The pathological examination of tumor sample revealed it as lowgrade endometrial stromal sarcoma (LESS). And the patient underwent 6 cycles of chemotherapy over 8 months before she got pregnant and had a full-term delivery. But in 34 months after delivery, the disease recurred with metastatic of pelvic and peritoneal cavity and the patient had to receive comprehensive therapy. Conclusion: The unmarried young patient with stage I low-grade endometrial stromal sarcoma has the chance to preserve uterus for her pregnancy and delivery. But the using of cesarean needs do staging operation and prognosis evaluation.展开更多
In an attempt to propagate and conserve the rare, showy bulbous plants of Iris bismarckiana, newly recorded to the flora of Jordan and to contribute to the conservation the wild lris species in Jordan, a simple rapid,...In an attempt to propagate and conserve the rare, showy bulbous plants of Iris bismarckiana, newly recorded to the flora of Jordan and to contribute to the conservation the wild lris species in Jordan, a simple rapid, time consuming protocol has been developed using plant regeneration via somatic embryogenesis. Somatic embryogenesis was induced in zygotic embryo culture on Murashige and Skoog (MS) medium supplemented with 2,4-dichlorophenoxy acetic acid (8 mg/L) as the sole plant growth regulator, where both embryogenesis calli and somatic embryos were induced. Separation of embryos from embryo clusters was necessary to enhance the frequency of germination. Germination was stimulated by separation of embryos successfully from embryo clusters and transferred onto fresh MS medium. Data obtained were analyzed as a complete random design with three replications. Calli fragments that were transferred to embryogenesis induction medium (EIM) produced white embryo-like globular structures within two weeks. Within three more weeks, clusters of structures at various stages of development could be found on the same callus. The applied technique is rewarding and encouraging for further research on the endangered wild species of Iris in Jordan.展开更多
Polydimethylsiloxane (PDMS), tetraethoxysilane (TEOS), ethyl alcohol (EtOH) and deionized water were main raw materials to prepare silicone-modified hybrid thin films using sol-gel method. The effect of the cont...Polydimethylsiloxane (PDMS), tetraethoxysilane (TEOS), ethyl alcohol (EtOH) and deionized water were main raw materials to prepare silicone-modified hybrid thin films using sol-gel method. The effect of the contents of H2O and PDMS on thin films was studied. When the volume ratio of H20 to TEOS is 0.5, the optimum quality of thin films is obtained. And the gelation time is affected slightly by H20 content. Uniform thin films are obtained when the volume ratio of PDMS to TEOS is 0.2. Yet, the sol would be inactive in 6 d. Various properties of thin films were studied, including hardness, adhesive quality, hydrophobic property, corrosion protection property, and abrasion resistance. Test results show that the pencil hardness is generally 3-6 H, and adhesive quality achieves the highest standard of 0. When the sintering temperature is below 400℃, the contact angle is about 95° and hydrophobic films are obtained. The abrasion resistance of thin films is better than that of aluminum alloy when the sintering temperature is higher than 300℃. And the excellent corrosion protective effect is obtained by single-layer coating when the sintering temperature is higher than 400℃.展开更多
In the frame of the Sino-ltalian Cooperation Program for Environmental Protection, jointly launched in the year 2000 by the Italian Ministry for Environment and Territory and Sea (IMETS) and the China State Environm...In the frame of the Sino-ltalian Cooperation Program for Environmental Protection, jointly launched in the year 2000 by the Italian Ministry for Environment and Territory and Sea (IMETS) and the China State Environmental Protection Administration (SEPA), experimental trials were carried out in Qingzhou city (Shandong Province, China) during 2001-2003 to test several methyl bromide alternative methods to control soilborne diseases in greenhouse tomatoes. Grafting tomatoes on resistant rootstock (Lyeopersicon lycopersicum × L. hirsutum), metham sodium applied under traditional polyethylene plastic films; metham sodium applied at low rate under virtually impermeable films and soil sotarization combined with biocontrol agents were the alternatives tested and compared to methyl bromide applied under virtually impermeable plastic films too. Collected data show that resistant rootstock (Lycopersicon tycopersicum × L. hirsutum) introduced from Italy is a promising alternative to methyl bromide for local tomato cultivars. Metham sodium applied under traditional polyethylene plastic films is an effective alternative. Moreovez virtually impermeable films demonstrate the help to reduce methyl bromide and metham sodium rates. Finally soil solarization combined with biocontrol agents does not provide satisfactory results in terms of disease control.展开更多
Orthogonal design was used to observe the gastrointestinal peristalsis in normal andatropine-treated mice after electroacupuncture was applied,singly or in combination,atNeiguan(P 6),Pishu(UB 20)and Zusanli(St 36).The...Orthogonal design was used to observe the gastrointestinal peristalsis in normal andatropine-treated mice after electroacupuncture was applied,singly or in combination,atNeiguan(P 6),Pishu(UB 20)and Zusanli(St 36).The results showed that:1)electroacupuncture has no significant effect on the gastrointestinal peristalsis in normalmice;2)Pishu(UB 20)was significantly antagonistic to Zusanli(St 36)in normal mice;3)the decreased gastrointestinal peristalsis in atropine-treated mice was markedly promotedby electroacupuncture at Zusanli(St 36);and 4)Neiguan(P 6)was significantlyantagonistic to Pishu(UB 20)in atropine-treated mice.The results indicated that thereciprocal actions among acupoints should be taken into consideration for pointprescription.展开更多
AIM: To investigate the protective effect and mechanism of rebamipide on small intestinal permeability induced by diclofenac in mice. METHODS: Diclofenac (2.5 mg/kg) was administered once daily for 3 d orally. A contr...AIM: To investigate the protective effect and mechanism of rebamipide on small intestinal permeability induced by diclofenac in mice. METHODS: Diclofenac (2.5 mg/kg) was administered once daily for 3 d orally. A control group received the vehicle by gavage. Rebamipide (100 mg/kg, 200 mg/kg, 400 mg/kg) was administered intragastrically once a day for 3 d 4 h after diclofenac administration. Intestinal permeability was evaluated by Evans blue and the FITC-dextran method. The ultrastructure of the mucosal barrier was evaluated by transmission electron microscopy (TEM). Mitochondrial function including mitochondrial swelling, mitochondrial membrane potential, mitochondrial nicotinamide adenine dinucleotide-reduced (NADH) levels, succinate dehydrogenase (SDH) and ATPase activities were measured. Small intestinal mucosa was collected for assessment of malondialdehyde (MDA) content and myeloperoxidase (MPO) activity. RESULTS: Compared with the control group, intestinal permeability was significantly increased in the diclofenac group, which was accompanied by broken tight junctions, and significant increases in MDA content and MPO activity. Rebamipide significantly reduced intestinal permeability, improved inter-cellular tight junctions, and was associated with decreases in intestinal MDA content and MPO activity. At the mitochondrial level, rebamipide increased SDH and ATPase activities, NADH level and decreased mitochondrial swelling. CONCLUSION: Increased intestinal permeability induced by diclofenac can be attenuated by rebamipide, which partially contributed to the protection of mitochondrial function.展开更多
文摘The effect of weak light on the peroxidation of membrane_lipid of one_year_old cherries ( Prunus pseudocerasus L. 'Laiyang') was studied by whole_tree shading. The results showed that the net photosynthetic rate of cherry leaves under weak light was remarkably lower; the activity peroxidase (POD) increased when light intensity decreased; the activity of catalase (CAT) showed an opposite trend, and it was positively correlated with light intensity; the activity of superoxide dismutase (SOD) increased under 366 μmol·m -2 ·s -1 and 533.8 μmol·m -2 ·s -1 light intensity, but decreased under 228.8 μmol·m -2 ·s -1 and 83.9 μmol·m -2 ·s -1 light intensity. A remarkable increase of malondialdehyde (MDA), a product of membrane_lipid peroxidation, was also observed in cherry leaves when treated with weak light, indicating more serious peroxidation in the membrane.
基金Project(2009AA03Z114)supported by the National High-tech Research and Development Program of ChinaProject(20090002110029)supported by the Specialized Research Fund for the Doctoral Program of Higher Education,China
文摘Sulphur dioxide (SO 2 ) mixed with carrier gases was used as an alternative to SF 6 to protect molten magnesium alloys. The protection behavior of AZ91D alloy in a sealed melting furnace was investigated under the atmosphere containing SO 2 with different mixed gases. The morphology and composition of the surface film were studied. The melt was well protected in an atmosphere of SO 2 and a proper amount of air, and was not protected properly in the other atmospheres. Based on the understanding of the protective effects of SO 2 in the sealed furnace, the protection mechanism of SO 2 -containing cover gases on molten AZ91D alloy was studied in an open melting furnace. The cover gas protected the melt by reacting with the melt to form a coherent protective film with a network structure on the melt surface. The film contains MgO and MgS. MgS increases the Pilling and Bedworth ratio of the surface film and enhances the protective capability of the films.
基金Supported by National Natural Science Foundation, No. 30572310Hunan Natural Science Foundation, No. 05JJ 4008
文摘AIM:To study the effect of moxibustion on Zusanli or Liangmeng point on gastric mucosa injury in stress-induced ulcer rats and its correlation with the expression of heat shock protein 70 (HSP70). METHODS:Sixty healthy SD rats (30 males,30 females) were divided into control group,injury model group,Zushanli point group,Liangmeng point group. Stress gastric ulcer model was induced by binding cold stress method. Gastric mucosa ulcer injury (UI) index was calculated by Guth method. Gastric mucosa blood flow (GMBF) was recorded with a biological signal analyzer. Protein content and gene expression in gastric mucosal HSP70 were detected by immunohistochemistry (IHC) and reverse transcription polymerase chain reaction (RT-PCR). Thiobarbital method was used to determine malondialdehyde (MDA) content. Gastric mucosal endothelin (ET) and prostaglandin E2 (PGE2) were analyzed by radioimmunoassay. RESULTS:High gastric mucosal UI index,high HSP70 expression,low GMBF and PGF2,elevated MDA and ET were observed in gastric mucosa of rats subjected to cold stress. Moxibustion on Zusanli or Liangmeng point decreased rat gastric mucosal UI index,MDA and ET. Conversely,the expression of HSP70,GMBF,and PGE2 was elevated in gastric mucosa after pretreatment with moxibustion on Zusanli or Liangmeng point. The observed parameters were significantly different between Zusanli and Liangmeng points. CONCLUSION:Pretreatment with moxibustion on Zusanli or Liangmeng point protects gastric mucosa against stress injury. This protection is associated with the higher expression of HSP70 mRNA and protein,leading to release of PGE2 and inhibition of MDA and ET,impairment of gastric mucosal index.
基金NSFC(No40173030, 40701164)Science and Technology Committee of Shanghai (No 04DZ19301)
文摘Based on a simulative experiment and a comparison analysis, the effect of bivalve Corbiculafluminea activity on sediment-water exchange of dissolved inorganic nitrogen (DIN) is studied. The areas included three intertidal flat sites of the Changjiang (Yangtze) River estuary in China. The interface exchange flux of ammonium, nitrate and nitrite in the short experiment (6 h) was -46.4-40, -74.8-929.1 and 2.5-14.6 μmol/(m^2·h), respectively. It was found that the burrowing activities of C. fluminea increased NH4 and NOi release from sediments to overlying water in the short-term experiment. During long-term incubation, NH4 and NOi released in turn from the sediments. At the beginning of incubation, bioturbation by C. fluminea could accelerate NH2 release from sediments 2-17 times in different sites, resulting in stronger nitrification and increased NOi concentrations in the overlying water. Sediment profile analysis post-incubation shows that organic matter mineralization and sediment-water NH4 exchange had been stimulated by C. fluminea bioturbation and bioirrigation during the experiment. Therefore, C. fluminea activities such as excretion, burrowing, irrigation and turbation can effectively alter nitrogen dynamics and accelerate and stimulate nitrogen exchange and cycling at the sediment-water interface.
基金supported by a research grant from Korea Institute of Materials Science (PNK4652)
文摘Magnesium phosphate conversion coating(MPCC)was fabricated on AZ31magnesium alloy for corrosion protection by immersion treatment in a simple MPCC solution containing Mg2+and3PO4?ions.The MPCC on AZ31Mg alloy showed micro-cracks structure and a uniform thickness with the thickness of about2.5μm after20min of phosphating treatment.The composition analyzed by energy dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy revealed that the coating consisted of magnesium phosphate and magnesium hydroxide/oxide compounds.The MPCC showed a significant protective effect on AZ31Mg alloy.The corrosion current of MPCC was reduced to about3%of that of the uncoated surface and the time for the deterioration process during immersion in0.5mol/L NaCl solution improved from about10min to about24h.
基金Supported by the Chinese Traditional Medicine Foundation of Guangdong Province, China, No. 102061
文摘AIM: To study the protective effect of Astragalus rnernbranaceus on intestinal mucosa reperfusion injury and its mechanism after hemorrhagic shock in rats. METHODS: A total of 32 SD rats were randomly divided into four groups (n = 8, each group): normal group, model group, low dosage group (treated with 10 g/kg Astragalus membranaceus) and high dosage group (treated with 20 g/kg Astragalus membranaceus). The model of hemorrhagic shock for 60 min and reperfusion for 90 min was established. Therapeutic solution (3 mL) was administrated before reperfusion. At the end of the study, the observed intestinal pathology was analyzed. The blood concentrations of lactic acid (LD), nitric oxide (NO), endothelin-1 (ET-1), malondialdehyde (MDA) and the activity of superoxide dismutase (SOD), glutathione peroxidase (GSH-PX) in intestinal mucosa were determined. RESULTS: The intestinal mucosa pathology showed severe damage in model group and low dosage group, slight damage in high dosage group and no obvious damage in normal group. The Chiu's score in low dose group and high dose group was significantly lower than that in model group. The content of MDA in model group was higher than that in low and high dose groups, while that in high dose group was almost the same as in normal group. The activity of SOD and GSH-PX was the lowest in model group and significantly higher in high dose group than in normal and low dose groups. The concentrations of LD and ET-1 in model group were the highest. The concentrations of NO in model group and low dose group were significantly lower than those in high dose group and normal group. CONCLUSION: High dose Astraga/us membranaeus has much better protective effect on hemorrhagic shockreperfusion injury of intestinal mucosa than low dose Astragalus membranaceus. The mechanism may be that Astragalus membranaceus can improve antioxidative effect and regulate NO/ET level during hemorrhagic reperfusion.
文摘AIM: To study the protective effect of a natural antioxidant, melatonin, against multistress condition induced lipid peroxidation v/a determination of gastric damage and plasma malondialdehyde (MDA) level by high performance liquid chromatography in rats. METHODS: We compared indomethacin-induced gastric damage and MDA plasma level in three groups of rats: unoperated, bile duct ligated and sham-operated and evaluated the role of the melatonin on gastric damage and plasma MDA level. Indomethacin and melatonin were injected intraperitoneally in doses of 50 mg/kg and 20 mg/kg, respectively. Animals were killed 4 h after indomethacin injection. RESULTS: Indomethacin induced more severe gastric damage and plasma MDA level in bile duct ligated animals was significantly higher (3.1±0.04 μmol/L) than sham (2.8±0.04 μmol/L) and unoperated animals (1.4±0.08 μmol/L). Pretreatment with melatonin reduced indomethacin-induced gastric damage and plasma MDA level. CONCLUSION: Considering the results of this study, we suggest that in multistress conditions the intensity of gastric damage and the plasma MDA level are great and melatonin reduces the negative effect of lipid peroxidation and cell damage by oxidative stress in multistress conditions due to its antioxidizing activity.
基金Project (5133001E) supported by the Major State Basic Research and Development Program of China
文摘The cerium conversion film was applied to improving the corrosion resistance of Mg-Gd-Y-Zr magnesium alloy. The film was electrodeposited on the surface of the Mg-RE alloy in cerium nitrate solution. The compositions and morphologies were analyzed by X-ray diffraction(XRD), scanning election microscopy (SEM). The corrosion behaviors of the film were investigated electrochemical impedance spectroscopy (EIS), potentiodynamic polarization tests and immersion tests. The results show that the optimum parameters for electrochemical deposition are as follows: pH 10.0, time 30 min, 50 mmol/L Na2CO3 and temperature 25 ℃ by the designed experiments according to the orthogonal table L(9, 34). The corrosion protection efficiency is dependent on the deposition parameters. The cerium conversion film shows better corrosion protection behavior than chromate conversion film on Mg-Gd-Y-Zr magnesium alloy.
文摘An explosive blast mitigation alternative has increased the safety of structures by using " catcher" systems. These systems " catch" or repel the failure of the window or in-fill wall pro-tecting life and property from ballistic shards or fragments. They can be designed to be stand-alone in new construction and structural retrofits or used to augment structural hardening tech-niques. Cables, fabrics, and thin gauge sheet steel are examples of catcher systems used in the past. A new and evolving category of catcher systems are based on polymeric materials that can be used for both wall and window upgrades. These products are a proven blast mitigation concept and K&C Protective Technologies Pte Ltd (KCPT) together with Sherwin-Williams(SW) use KCPT′s blast engineering capacity and SW′s material engineering principles to create engineered systems for even greater in-use performance.
基金Project(cstc2011jj A50008)supported by the Natural Science Foundation of Chongqing,ChinaProject(14ZB0025)supported by Education Department of Sichuan Province,China
文摘Zn-doped TiO2 (Zn?TiO2) thin films were prepared by the sol?gel method on titanium substrates with heat treatment at different temperatures. The effects of heat treatment temperatures and Zn doping on the structure, photocathodic protection and photoelectrochemical properties of TiO2 thin films were investigated. It is indicated that the photoelectrical performance of the Zn?TiO2 films is enhanced with the addition of Zn element compared with the pure-TiO2 film and the largest decline by 897 mV in the electrode potential is achieved under 300 °C heat treatment. SEM?EDS analyses show that Zn element is unevenly distributed in Zn?TiO2 films; XRD patterns reveal that the grain size of Zn?TiO2 is smaller than that of pure-TiO2; FTIR results indicate that Zn - O bond forms on Zn?TiO2 surface. Ultraviolet visible absorption spectra prove that Zn?TiO2 shifts to visible light region.Mott?Shottky curves show that the flat-band potential of Zn?TiO2 is more negative and charge carrier density is bigger than that ofpure-TiO2, implying that under the synergy of the width of the space-charge layer, carrier density and flat-band potential, Zn?TiO2 with 300 °C heat treatment displays the best photocathodic protection performance.
文摘The paper introduced the experience of a case of recurrence of endometrial stromal sarcoma with fertility conservation treatment after full-term delivery. A 24-year-old unmarried patient who, with her increasing amount of menstruation in the late six months, had a mass in her lower-abdominal which was confirmed by B-ultrasonic diagnosis as myometrium mixed mass, was given an enucleation of uterus tumor. The pathological examination of tumor sample revealed it as lowgrade endometrial stromal sarcoma (LESS). And the patient underwent 6 cycles of chemotherapy over 8 months before she got pregnant and had a full-term delivery. But in 34 months after delivery, the disease recurred with metastatic of pelvic and peritoneal cavity and the patient had to receive comprehensive therapy. Conclusion: The unmarried young patient with stage I low-grade endometrial stromal sarcoma has the chance to preserve uterus for her pregnancy and delivery. But the using of cesarean needs do staging operation and prognosis evaluation.
文摘In an attempt to propagate and conserve the rare, showy bulbous plants of Iris bismarckiana, newly recorded to the flora of Jordan and to contribute to the conservation the wild lris species in Jordan, a simple rapid, time consuming protocol has been developed using plant regeneration via somatic embryogenesis. Somatic embryogenesis was induced in zygotic embryo culture on Murashige and Skoog (MS) medium supplemented with 2,4-dichlorophenoxy acetic acid (8 mg/L) as the sole plant growth regulator, where both embryogenesis calli and somatic embryos were induced. Separation of embryos from embryo clusters was necessary to enhance the frequency of germination. Germination was stimulated by separation of embryos successfully from embryo clusters and transferred onto fresh MS medium. Data obtained were analyzed as a complete random design with three replications. Calli fragments that were transferred to embryogenesis induction medium (EIM) produced white embryo-like globular structures within two weeks. Within three more weeks, clusters of structures at various stages of development could be found on the same callus. The applied technique is rewarding and encouraging for further research on the endangered wild species of Iris in Jordan.
基金supported partly by the School of Mechanical,Electronic and Control Engineering,Beijing Jiaotong university,China
文摘Polydimethylsiloxane (PDMS), tetraethoxysilane (TEOS), ethyl alcohol (EtOH) and deionized water were main raw materials to prepare silicone-modified hybrid thin films using sol-gel method. The effect of the contents of H2O and PDMS on thin films was studied. When the volume ratio of H20 to TEOS is 0.5, the optimum quality of thin films is obtained. And the gelation time is affected slightly by H20 content. Uniform thin films are obtained when the volume ratio of PDMS to TEOS is 0.2. Yet, the sol would be inactive in 6 d. Various properties of thin films were studied, including hardness, adhesive quality, hydrophobic property, corrosion protection property, and abrasion resistance. Test results show that the pencil hardness is generally 3-6 H, and adhesive quality achieves the highest standard of 0. When the sintering temperature is below 400℃, the contact angle is about 95° and hydrophobic films are obtained. The abrasion resistance of thin films is better than that of aluminum alloy when the sintering temperature is higher than 300℃. And the excellent corrosion protective effect is obtained by single-layer coating when the sintering temperature is higher than 400℃.
基金supported by the Italian Ministry for the Environment,Territory and Sea and State Environmental Protection Administration of China under the project of "Transfer of alternative technologies to the use of methyl bromide and capacity-building in the soil fumigation sector in China"
文摘In the frame of the Sino-ltalian Cooperation Program for Environmental Protection, jointly launched in the year 2000 by the Italian Ministry for Environment and Territory and Sea (IMETS) and the China State Environmental Protection Administration (SEPA), experimental trials were carried out in Qingzhou city (Shandong Province, China) during 2001-2003 to test several methyl bromide alternative methods to control soilborne diseases in greenhouse tomatoes. Grafting tomatoes on resistant rootstock (Lyeopersicon lycopersicum × L. hirsutum), metham sodium applied under traditional polyethylene plastic films; metham sodium applied at low rate under virtually impermeable films and soil sotarization combined with biocontrol agents were the alternatives tested and compared to methyl bromide applied under virtually impermeable plastic films too. Collected data show that resistant rootstock (Lycopersicon tycopersicum × L. hirsutum) introduced from Italy is a promising alternative to methyl bromide for local tomato cultivars. Metham sodium applied under traditional polyethylene plastic films is an effective alternative. Moreovez virtually impermeable films demonstrate the help to reduce methyl bromide and metham sodium rates. Finally soil solarization combined with biocontrol agents does not provide satisfactory results in terms of disease control.
文摘Orthogonal design was used to observe the gastrointestinal peristalsis in normal andatropine-treated mice after electroacupuncture was applied,singly or in combination,atNeiguan(P 6),Pishu(UB 20)and Zusanli(St 36).The results showed that:1)electroacupuncture has no significant effect on the gastrointestinal peristalsis in normalmice;2)Pishu(UB 20)was significantly antagonistic to Zusanli(St 36)in normal mice;3)the decreased gastrointestinal peristalsis in atropine-treated mice was markedly promotedby electroacupuncture at Zusanli(St 36);and 4)Neiguan(P 6)was significantlyantagonistic to Pishu(UB 20)in atropine-treated mice.The results indicated that thereciprocal actions among acupoints should be taken into consideration for pointprescription.
文摘AIM: To investigate the protective effect and mechanism of rebamipide on small intestinal permeability induced by diclofenac in mice. METHODS: Diclofenac (2.5 mg/kg) was administered once daily for 3 d orally. A control group received the vehicle by gavage. Rebamipide (100 mg/kg, 200 mg/kg, 400 mg/kg) was administered intragastrically once a day for 3 d 4 h after diclofenac administration. Intestinal permeability was evaluated by Evans blue and the FITC-dextran method. The ultrastructure of the mucosal barrier was evaluated by transmission electron microscopy (TEM). Mitochondrial function including mitochondrial swelling, mitochondrial membrane potential, mitochondrial nicotinamide adenine dinucleotide-reduced (NADH) levels, succinate dehydrogenase (SDH) and ATPase activities were measured. Small intestinal mucosa was collected for assessment of malondialdehyde (MDA) content and myeloperoxidase (MPO) activity. RESULTS: Compared with the control group, intestinal permeability was significantly increased in the diclofenac group, which was accompanied by broken tight junctions, and significant increases in MDA content and MPO activity. Rebamipide significantly reduced intestinal permeability, improved inter-cellular tight junctions, and was associated with decreases in intestinal MDA content and MPO activity. At the mitochondrial level, rebamipide increased SDH and ATPase activities, NADH level and decreased mitochondrial swelling. CONCLUSION: Increased intestinal permeability induced by diclofenac can be attenuated by rebamipide, which partially contributed to the protection of mitochondrial function.